Ultra Clean (UCTT) 10-Q 4 Aug 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 25, 2021	Jul. 23, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 25, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Trading Symbol	UCTT
Entity Registrant Name	Ultra Clean Holdings, Inc.
Entity Central Index Key	0001275014
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common stock, par value $0.001 per share
Entity Incorporation, State or Country Code	DE
Security Exchange Name	NASDAQ
Entity File Number	000-50646
Entity Tax Identification Number	61-1430858
Entity Address, Address Line One	26462 Corporate Avenue
Entity Address, City or Town	Hayward
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94545
City Area Code	510
Local Phone Number	576-4400
Entity Common Stock, Shares Outstanding		44,700,000

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 25, 2021	Dec. 25, 2020
Current assets:
Cash and cash equivalents	$ 451.4	$ 200.3
Accounts receivable, net of allowance for doubtful accounts of $0.5 and $0.3 at June 25, 2021 and December 25, 2020, respectively	210.4	145.5
Inventories	302	180.4
Prepaid expenses and other current assets	35.5	18.9
Total current assets	999.3	545.1
Property, plant and equipment, net	218.3	159.2
Goodwill	257.2	171.1
Intangibles assets, net	270.5	160.5
Deferred tax assets, net	23.3	23.5
Operating lease right-of-use assets	69.8	37.8
Other non-current assets	8.3	5.3
Total assets	1,846.7	1,102.5
Current liabilities:
Bank borrowings	21.6	7.4
Accounts payable	231	121.3
Accrued compensation and related benefits	43.9	34.5
Operating lease liabilities	16	11.7
Other current liabilities	42.5	26.3
Total current liabilities	355	201.2
Bank borrowings, net of current portion	573.1	261.6
Deferred tax liabilities	45.5	33.6
Operating lease liabilities	54.3	31.1
Other liabilities	30.1	23.8
Total liabilities	1,058	551.3
Commitments and contingencies (See Note 10)
UCT stockholders’ equity:
Preferred stock — $0.001 par value, 10.0 shares authorized; none outstanding
Common stock — $0.001 par value, 90.0 shares authorized; 44.7 shares and 40.6 shares issued and outstanding at June 25, 2021 and December 25, 2020, respectively	0.1	0.1
Additional paid-in capital	506.1	312.8
Common shares held in treasury, at cost, 0.6 shares at June 25, 2021 and December 25, 2020	(3.3)	(3.3)
Retained earnings	260	217.9
Accumulated other comprehensive gain	4.6	5.1
Total UCT stockholders' equity	767.5	532.6
Noncontrolling interests	21.2	18.6
Total equity	788.7	551.2
Total liabilities and stockholders' equity	$ 1,846.7	$ 1,102.5

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 25, 2021	Dec. 25, 2020
Statement Of Financial Position [Abstract]
Account receivable, allowance for doubtful accounts	$ 0.5	$ 0.3
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	90,000,000	90,000,000
Common stock, shares issued	44,700,000	40,600,000
Common stock, shares outstanding	44,700,000	40,600,000
Treasury stock, shares	600,000	600,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Revenues:
Total revenues	$ 515.2	$ 344.8	$ 932.8	$ 665.7
Cost of revenues:
Total cost of revenues	415.3	270.9	746	526.1
Gross profit	99.9	73.9	186.8	139.6
Operating expenses:
Research and development	6.1	3.8	10.3	7.2
Sales and marketing	12.7	5.9	20.3	11.7
General and administrative	49.2	33.4	83.9	67.3
Total operating expenses	68	43.1	114.5	86.2
Income from operations	31.9	30.8	72.3	53.4
Interest income	0.1	0.2	0.2	0.5
Interest expense	(7.1)	(3.8)	(10.7)	(9)
Other income (expense), net	(0.7)	0.6	(5)	(2.1)
Income before provision for income taxes	24.2	27.8	56.8	42.8
Provision for income taxes	6.2	5.7	13.2	10.2
Net income	18	22.1	43.6	32.6
Less: Net income attributable to noncontrolling interests	0.9	0.8	1.5	1.9
Net income attributable to UCT	$ 17.1	$ 21.3	$ 42.1	$ 30.7
Net income per share attributable to UCT common stockholders:
Basic	$ 0.39	$ 0.53	$ 1	$ 0.77
Diluted	$ 0.39	$ 0.52	$ 0.98	$ 0.75
Shares used in computing net income per share:
Basic	43.3	40.1	41.9	39.9
Diluted	44.3	40.8	42.9	40.8
Product [Member]
Revenues:
Products	$ 442.5	$ 277.9	$ 788.1	$ 537.3
Cost of revenues:
Products	367.9	229.3	651.5	444
Gross profit			136.6
Operating expenses:
Income from operations			58.2
Services [Member]
Revenues:
Products	72.7	66.9	144.7	128.4
Cost of revenues:
Products	$ 47.4	$ 41.6	94.5	$ 82.1
Gross profit			50.2
Operating expenses:
Income from operations			$ 14.1

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 18	$ 22.1	$ 43.6	$ 32.6
Other comprehensive gain (loss):
Change in cumulative translation adjustment	2.2	1.2	(0.6)	(2)
Change in fair value of derivatives	0.8	0.1	0.1
Total other comprehensive gain (loss)	3	1.3	(0.5)	(2)
Other comprehensive income, attributable to noncontrolling interests	0.9	0.8	1.5	1.9
Comprehensive income attributable to UCT	$ 20.1	$ 22.6	$ 41.6	$ 28.7

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020
Cash flows from operating activities:
Net income	$ 18	$ 18	$ 22.1	$ 22.1	$ 43.6	$ 32.6	$ 32.6
Adjustments to reconcile net income to net cash provided by operating activities (excluding assets acquired and liabilities assumed):
Depreciation and amortization					15.1		12.6
Amortization of intangible assets					14.4		9.9
Stock-based compensation		3.7		3.1	7.2	6.2	6.2
Amortization of debt issuance costs					1.4		0.9
Gain from insurance proceeds					(7.3)		(0.6)
Deferred income taxes					0.9
Change in the fair value of financial instruments and earn-out liability					13		4.2
Others					0.2		0.3
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivable					(13.3)		(26)
Inventories					(41.3)		(21.5)
Prepaid expenses and other current assets					(0.3)		(1.6)
Other non-current assets					(0.7)		0.3
Accounts payable					80.8		6.5
Accrued compensation and related benefits					(1.1)		2.8
Income taxes payable					0.9		4.9
Operating lease assets and liabilities					(0.6)		(0.5)
Other liabilities					3.8		2.2
Net cash provided by operating activities					116.7		33.2
Cash flows from investing activities:
Purchases of property, plant and equipment					(22.7)		(17)
Proceeds from sale of equipment, including insurance proceeds					7.4		2.9
Settlement of forward contracts in conjunction with the acquisition of Ham-Let					(10.4)
Acquisition of business, net of cash acquired					(344.8)
Net cash used in investing activities					(370.5)		(14.1)
Cash flows from financing activities:
Proceeds from bank borrowings					371.5		60.5
Proceeds from issuance of common stock					193.1		0.3
Principal payments on bank borrowings and finance leases					(43.4)		(26.3)
Payments of debt issuance costs					(8.9)
Payments of dividends to a joint venture shareholder					(0.1)
Employees’ taxes paid upon vesting of restricted stock units					(7)		(1.4)
Net cash provided by financing activities					505.2		33.1
Effect of exchange rate changes on cash and cash equivalents					(0.3)		(0.3)
Net increase in cash and cash equivalents					251.1		51.9
Cash and cash equivalents at beginning of period					200.3		162.5
Cash and cash equivalents at end of period	$ 451.4	$ 451.4	$ 214.4	$ 214.4	451.4	$ 214.4	214.4
Supplemental cash flow information:
Income taxes paid, net of income tax refunds					10.8		4.6
Interest paid					8.1		9.2
Non-cash investing and financing activities:
Property, plant and equipment purchased included in accounts payable and other liabilities					$ 4.7		$ 2.5

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Shares [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total stockholder's Equity of UCT [Member]	Noncontrolling Interests [Member]
Beginning balance at Dec. 27, 2019	$ 452.5	$ 0.1	$ 300.9	$ (3.3)	$ 140.3	$ (1.3)	$ 436.7	$ 15.8
Beginning balance, Shares at Dec. 27, 2019		39,900,000		600,000
Issuance under employee stock plans	0.3		0.3				0.3
Issuance under employee stock plans, Shares		500,000
Stock-based compensation expense	6.2		6.2				6.2
Taxes paid related to net share settlement of equity awards	(1.4)		(1.4)				(1.4)
Taxes paid related to net share settlement of equity awards, Shares		(100,000)
Net income	32.6				30.7		30.7	1.9
Other comprehensive loss	(2)					(2)	(2)
Ending balance at Jun. 26, 2020	488.2	$ 0.1	306	$ (3.3)	171	(3.3)	470.5	17.7
Ending balance, Shares at Jun. 26, 2020		40,300,000		600,000
Beginning balance at Mar. 27, 2020	462.8	$ 0.1	304	$ (3.3)	149.7	(4.6)	445.9	16.9
Beginning balance, Shares at Mar. 27, 2020		39,900,000		600,000
Issuance under employee stock plans	0.3		0.3				0.3
Issuance under employee stock plans, Shares		500,000
Stock-based compensation expense	3.1		3.1				3.1
Taxes paid related to net share settlement of equity awards	(1.4)		(1.4)				(1.4)
Taxes paid related to net share settlement of equity awards, Shares		(100,000)
Net income	22.1				21.3		21.3	0.8
Other comprehensive loss	1.3					1.3	1.3
Ending balance at Jun. 26, 2020	488.2	$ 0.1	306	$ (3.3)	171	(3.3)	470.5	17.7
Ending balance, Shares at Jun. 26, 2020		40,300,000		600,000
Beginning balance at Dec. 25, 2020	551.2	$ 0.1	312.8	$ (3.3)	217.9	5.1	532.6	18.6
Beginning balance, Shares at Dec. 25, 2020		40,600,000		600,000
Issuance of common stock in public offering	192.8		192.8				192.8
Issuance of common stock in public offering, Shares		3,700,000
Issuance under employee stock plans	0.3		0.3				0.3
Issuance under employee stock plans, Shares		600,000
Employees’ taxes paid upon vesting of restricted stock units	(7)		(7)				(7)
Employees' taxes paid upon vesting of restricted stock units, Shares		(100,000)
Stock-based compensation expense	7.2		7.2				7.2
Noncontrolling interests from acquisition of Ham-Let	1.2							1.2
Net income	43.6				42.1		42.1	1.5
Dividend payments to a joint venture shareholder	0.1							0.1
Other comprehensive loss	(0.5)					(0.5)	(0.5)
Ending balance at Jun. 25, 2021	788.7	$ 0.1	506.1	$ (3.3)	260	4.6	767.5	21.2
Ending balance, Shares at Jun. 25, 2021		44,800,000		600,000
Beginning balance at Mar. 26, 2021	576.6	$ 0.1	316.3	$ (3.3)	242.9	1.6	557.6	19
Beginning balance, Shares at Mar. 26, 2021		40,600,000		600,000
Issuance of common stock in public offering	192.8		192.8				192.8
Issuance of common stock in public offering, Shares		3,700,000
Issuance under employee stock plans	0.3		0.3				0.3
Issuance under employee stock plans, Shares		600,000
Employees’ taxes paid upon vesting of restricted stock units	(7)		(7)				(7)
Employees' taxes paid upon vesting of restricted stock units, Shares		(100,000)
Stock-based compensation expense	3.7		3.7				3.7
Noncontrolling interests from acquisition of Ham-Let	1.2							1.2
Net income	18				17.1		17.1	0.9
Dividend payments to a joint venture shareholder	0.1							0.1
Other comprehensive loss	3					3	3
Ending balance at Jun. 25, 2021	$ 788.7	$ 0.1	$ 506.1	$ (3.3)	$ 260	$ 4.6	$ 767.5	$ 21.2
Ending balance, Shares at Jun. 25, 2021		44,800,000		600,000

Organization and Significant Ac

Organization and Significant Accounting Policies	6 Months Ended
	Jun. 25, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Significant Accounting Policies	1. ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES Organization — Ultra Clean Holdings, Inc., (the “Company” or “UCT”) a Delaware corporation, was founded in November 2002 and became a publicly traded company on the NASDAQ Global Market in March 2004. Ultra Clean Holdings, Inc. is a leading developer and supplier of critical subsystems, components and parts, and ultra-high purity cleaning and analytical services primarily for the semiconductor industry. UCT offers its customers an integrated outsourced solution for major subassemblies, improved design-to-delivery cycle times, design for manufacturability, prototyping and part and component manufacturing, as well as tool chamber parts cleaning and coating, and micro-contamination analytical services. The Company operates and reports results for two operating segments: Products and Services (formerly known as “SPS” and “SSB”, respectively). The Company’s Products business primarily designs, engineers and manufactures production tools, components and parts, and modules and subsystems for the semiconductor and display capital equipment markets. Products include chemical delivery modules, frame assemblies, gas delivery systems, fluid delivery systems, precision robotics, process modules as well as other high-level assemblies. The Company’s Services business provides ultra-high purity parts cleaning, process tool part recoating, surface encapsulation and high sensitivity micro contamination analysis primarily for the semiconductor device makers and wafer fabrication equipment markets . On March 31, 2021, the Company completed the acquisition of Ham-Let (Israel-Canada) Ltd. (“ , a public company organized under the laws of the State of On April 13, 2021, the Company completed an underwritten public offering of 3,181,818 shares of the Company’s common stock, in which the Company received net proceeds of approximately $167.6 million, after deducting the underwriting discounts and offering expenses payable by the Company. On April 29, 2021, the Underwriters exercised the option to purchase an additional 477,272 shares of the Company’s common stock for approximately $25.2 million in cash. The Company intends to use the net proceeds from this offering for general corporate purposes, which may include working capital, sales and marketing activities, product development, general and administrative matters, and capital expenditures. The Company may use a portion of the net proceeds to acquire complementary businesses, products, services, or technologies, although it has no agreements, commitments, or plans for any specific acquisitions at this time. Basis of Presentation — The unaudited Condensed Consolidated Financial Statements included in this quarterly report on Form 10-Q include the accounts of the Company and its majority-owned subsidiaries and have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). This financial information reflects all adjustments which are, in the opinion of the Company, normal, recurring and necessary for the fair financial statement presentation for the dates and periods presented. Certain information and footnote disclosures normally included in our annual financial statements, prepared in accordance with GAAP, have been condensed or omitted. The Company’s December 25, 2020 balance sheet data were derived from its audited financial statements as of that date. Fiscal Year — The Company uses a 52-53 week fiscal year ending on the Friday nearest December 31. All references to quarters refer to fiscal quarters and all references to years refer to fiscal years. Principles of Consolidation — The Company’s Condensed Consolidated Financial Statements include the accounts of the Company and its majority-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated upon consolidation. Noncontrolling interests — Noncontrolling interests are recognized to reflect the portion of the equity of the majority-owned subsidiaries which is not attributable, directly or indirectly, to the controlling stockholder. The Company’s consolidated entities include partially-owned entities, which are (1) Cinos Co., Ltd (“Cinos Korea”), a South Korean company that provides outsourced cleaning and recycling of precision parts for the semiconductor industry through its operating facilities in South Korea, (2) Cinos Xian Clean Technology, Ltd. (“Cinos China”), a Chinese entity that is partially owned by Cinos Korea and (3) Rovac Pte, Ltd (“Rovac”), a Singaporean Company that is majority owned by Ham-Let. The interest held by others in Cinos Korea, in Cinos China and in Rovac are presented as noncontrolling interests in the accompanying Condensed Consolidated Financial Statements. The noncontrolling interests will continue to be attributed its share of gains and losses even if that attribution results in a deficit noncontrolling interests’ balance. Segments — The Financial Accounting Standards Board’s (“FASB”) guidance regarding disclosure about segments in an enterprise and related information establishes standards for the reporting by public business enterprises of information about reportable segments, products and services, geographic areas, and major customers. The method for determining what information to report is based on the manner in which management organizes the reportable segments within the Company for making operational decisions and assessments of financial performance. The Company’s chief operating decision-maker is the Chief Executive Officer. The Company operates and reports two segments: Products and Services. Ham-Let’s business activities are similar to Products and, therefore, were included within this segment. See Note 16 of the Notes to the Condensed Consolidated Financial Statements. Foreign Currency Translation and Remeasurement — The functional currency of the majority of the Products division’s foreign subsidiaries is the U.S. dollar. The functional currency of the Service division’s foreign subsidiaries is the local currency except for that of its Singapore and Scotland entities, which is the U.S. dollar. For the Company’s foreign subsidiaries where the local currency is the functional currency, the Company translates the financial statements of these subsidiaries to U.S. dollars using month-end exchange rates for assets and liabilities, and average exchange rates for revenue, costs and expenses. Translation gains and losses are recorded in accumulated other comprehensive income (AOCI) within UCT stockholders’ equity. For the Company’s foreign subsidiaries where the U.S. dollar is the functional currency, any gains and losses resulting from the translation of the assets and liabilities of these subsidiaries are recorded in other income (expense), net. Use of Estimates — The presentation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Such estimates and assumptions include inventory valuation, accounting for income taxes, business combinations, valuation of goodwill, intangible assets and long-lived assets. The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. However, future events are subject to change and the best estimates and judgments routinely require adjustments. Actual amounts may differ from those estimates. Cash and Cash Equivalents — The Company considers currency on hand, demand deposits, time deposits, and all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash and cash equivalents. Cash and cash equivalents are held in various financial institutions in the United States and internationally. Concentration of Credit Risk — Financial instruments which subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. The Company sells its products and provides services primarily to semiconductor capital equipment manufacturers in the United States. The Company performs credit evaluations of its customers’ financial condition and generally requires no collateral. The Company’s most significant customers (having accounted for 10% or more of revenues) and their related revenues as a percentage of total revenues were as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 Lam Research Corporation 38.3 % 39.6 % 41.6 % 42.0 % Applied Materials, Inc. 24.1 % 25.8 % 23.9 % 24.7 % Total 62.4 % 65.4 % 65.5 % 66.7 % Two customers’ accounts receivable balances, Lam Research Corporation and Applied Materials, Inc., were individually greater than 10% of accounts receivable as of June 25, 2021 Three Fair Value of Measurements — The Company measures its cash equivalents, derivative contracts, contingent earn-out liabilities, pension obligation and common stock purchase obligation at fair value on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset or a liability. Assets and liabilities recorded at fair value are measured and classified in accordance with a three-tier fair value hierarchy based on the observability of the inputs available in the market used to measure fair value: Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 — Inputs that are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant inputs are observable in the market or can be derived from observable market data. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs including interest rate curves, foreign exchange rates, and credit ratings. Level 3 — Unobservable inputs that are supported by little or no market activities. Derivative Financial Instruments — The Company uses forward contracts to hedge a portion of, but not all, existing and anticipated foreign currency denominated transactions typically expected to occur within 24 months. The purpose of the hedge is to mitigate the effect of exchange rate fluctuations on certain foreign currency denominated costs and eventual cash flows. The Company recognizes derivative instruments as either assets or liabilities in the accompanying Condensed Consolidated Balance Sheets at fair value. The Company records changes in the fair value of the derivatives in the accompanying Condensed Consolidated Statements of Operations as other income (expense), net, or as a component of AOCI in the accompanying Condensed Consolidated Balance Sheets. Inventories — Inventories are stated at the lower of cost (which approximates actual cost on a first-in, first-out basis) or net realizable value. The Company evaluates the valuation of all inventories, including raw materials, work-in-process, finished goods and spare parts on a periodic basis. Obsolete inventory or inventory in excess of management’s estimated usage is written down to its estimated market value less costs to sell, if less than its cost. Inherent in the estimates of market value are management’s estimates related to economic trends, future demand for products, and technological obsolescence of the Company’s products. Inventory write downs inherently involve judgments based on assumptions about expected future demand and the impact of market conditions on those assumptions. Although the Company believes that the assumptions it used in estimating inventory write downs are reasonable, significant changes in any one of the assumptions in the future could produce a significantly different result. There can be no assurances that future events and changing market conditions will not result in significant increases in inventory write downs. Property, Plant and — Property, plant and equipment are stated at cost, or, in the case of equipment under finance leases, the present value of future minimum lease payments at inception of the related lease. The Company also capitalizes interest on borrowings related to eligible capital expenditures. Capitalized interest is added to the cost of the qualified assets and is subject to depreciation. Depreciation and amortization are computed using the straight-line method over the lesser of the estimated useful lives of the assets or the terms of the leases. Useful lives range from three to fifty years ten years Long-lived Assets — The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate the carrying value of an asset group may not be recoverable. The Company assesses the fair value of the assets based on the amount of the undiscounted future cash flows that the assets are expected to generate and recognizes an impairment loss when estimated undiscounted future cash flows expected to result from the use of the asset are less than the carrying value of the asset. If the Company identifies an impairment, the Company reduces the carrying value of the group of assets to comparable market values, when available and appropriate, or to its estimated fair value based on a discounted cash flow approach. The Company assessed the useful lives of its long-lived assets, including property, plant and equipment as well as its intangible assets as of June 25, 2021 and concluded that no impairment was required. Leases — The Company determines if an arrangement is a lease, or contains a lease, at the inception of the arrangement. When the Company determines the arrangement is a lease, or contains a lease, at lease inception, it then determines whether the lease is an operating lease or a finance lease. Operating and finance leases with lease terms of one year or greater result in the Company recording a right-of-use (ROU) asset and lease liability on its balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating and finance lease ROU assets and liabilities are initially recognized based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses the implicit interest rate if readily determinable or when the implicit interest rate is not readily determinable, the Company uses its incremental borrowing rate. The incremental borrowing rate is not a commonly quoted rate and is derived through a combination of inputs including the Company’s credit rating and the impact of full collateralization. The incremental borrowing rate is based on the Company’s collateralized borrowing capabilities over a similar term of the lease payments. The Company utilizes the consolidated group incremental borrowing rate for all leases. The operating lease ROU asset also includes any lease payments made and excludes any lease incentives. Specific lease terms used in computing the ROU assets and lease liabilities may include options to extend or terminate the lease when the Company believes it is reasonably certain that it will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. As allowed by the guidance, the Company has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases for any class of underlying asset. Operating leases are included in operating lease ROU assets, other current liabilities, and long-term operating lease liabilities on the Company’s consolidated balance sheet. The Company’s finance leases at June 25, 2021 and December 25, 2020 were not significant. Goodwill and Indefinite Lived Intangible Assets — Goodwill and indefinite-lived intangible assets are not amortized, but are reviewed for impairment annually. Intangible assets are presented at cost, net of accumulated amortization, and are amortized on either a straight-line method or on an accelerated method over their estimated future discounted cash flows. The Company reviews goodwill and purchased intangible assets with indefinite lives for impairment annually and whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable, such as when reductions in demand or significant economic slowdowns in the semiconductor industry are present. Deferred Debt Issuance Costs — Debt issuance costs incurred in connection with obtaining debt financing are deferred and presented as a direct deduction from Bank Borrowings in the accompanying Condensed Consolidated Balance Sheets. Deferred costs are amortized on an effective interest method basis over the contractual term. Defined Benefit Pension Plan — The Company has a noncontributory defined benefit pension plan covering substantially all of the employees of one of its foreign entities upon termination of their employee services. For further discussion of the Company’s defined benefit pension plan see Note 9 of the Notes to the Condensed Consolidated Financial Statements. Revenue Recognition — Revenue is recognized when control of the promised goods or services is transferred to the Company’s customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The Company performs the following five steps to determine when to recognize revenue: (1) identification of the contract(s) with customers, (2) identification of the performance obligations in the contract, (3) determination of the transaction price, (4) allocation of the transaction price to the performance obligations in the contract, and (5) recognition of revenue when, or as, a performance obligation is satisfied. Shipping and Handling Costs — Shipping and handling costs are included as a component of cost of revenues. Research and Development Costs — Research and development costs are expensed as incurred. Stock-Based Compensation Expense — The Company maintains stock-based compensation plans which allow for the issuance of equity-based awards to executives and certain employees. These equity-based awards include restricted stock awards and restricted stock units. The Company also maintains an employee stock purchase plan (“ESPP”) that provides for the issuance of shares to all eligible employees of the Company at a discounted price. Government Subsidies — Government subsidies are recognized where there is reasonable assurance that the subsidy will be received and all attached conditions will be complied with. When the subsidy relates to an expense item, it is recognized as income on a systematic basis over the periods that the related costs, for which it is intended to compensate, are expensed. When the subsidy relates to an asset, it is recognized as income in equal amounts over the expected useful life of the related asset. When the subsidy does not relate to specific expenses or assets, the income is accounted for in the period where there is reasonable assurance that the subsidy will be received. Income Taxes — The Company utilizes the asset and liability method of accounting for income taxes, under which deferred taxes are determined based on the temporary differences between the financial statement and tax basis of assets and liabilities using tax rates expected to be in effect during the years in which the basis differences reverse. Deferred income taxes arise from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements, which will result in taxable or deductible amounts in the future. In evaluating our ability to realize our deferred tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies, and results of recent operations. In projecting future taxable income, we begin with historical results and incorporate assumptions about the amount of future federal, state, and foreign pretax operating income adjusted for items that do not have tax consequences. The assumptions about future taxable income require significant judgment and are consistent with the plans and estimates we are using to manage the underlying businesses. In evaluating the objective evidence that historical results provide, we consider recent cumulative income (loss). A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. Income tax positions must meet a more likely than not recognition threshold to be recognized. The Company recognizes tax benefits from uncertain tax positions only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits within the consolidated statements of income as income tax expense. The Company accounts for Global Intangible Low-Taxed Income (“GILTI”) as period costs when incurred. Net Income per Share — Basic net income per share is computed by dividing net income by the weighted average number of shares outstanding for the period. Diluted net income per share is calculated by dividing net income by the weighted average number of common shares outstanding and common equivalent shares from dilutive restricted stock using the treasury stock method, except when such shar es are anti-dilutive. See Note 15 of the Notes to the Condensed Consolidated Financial Statements. Business Combinations — The Company recognizes assets acquired (including goodwill and identifiable intangible assets), liabilities assumed and noncontrolling interest at fair value on the acquisition date. Subsequent changes to the fair value of such assets acquired and liabilities assumed are recognized in earnings, after the expiration of the measurement period, a period not to exceed 12 months from the acquisition date. Acquisition-related expenses and acquisition-related restructuring costs are recognized in earnings in the period in which they are incurred. Accounting Standard Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financing Reporting. This guidance provides temporary optional expedients and exceptions through December 31, 2022 to the U.S. GAAP guidance on contract modifications to ease the financial reporting burdens of the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates. The Company expects to adopt this guidance and apply it to reference rate reform effected arrangement modifications. Although there are several other new accounting pronouncements issued by the FASB, the Company does not believe any of these accounting pronouncements had or will have a material impact on its Consolidated Financial Statements.

Business Combinations

Business Combinations	6 Months Ended
	Jun. 25, 2021
Business Combinations [Abstract]
Business Combinations	2. BUSINESS COMBINATIONS Ham-Let On March 31, 2021, the Company acquired all of the outstanding common shares of Ham-Let for total purchase consideration of $362.9 million, which included $273.5 million of equity value plus $91.3 million of net debt offset by the settlement of an existing relationship of $1.9 million (vendor of UCT). In addition, the Company incurred approximately $10.5 million of costs related to the acquisition ($1.0 million incurred in fiscal year 2020 and $9.5 million was charged to operations for the six months ended June 25, 2021). Ham-Let engages in the development, manufacturing and marketing of a process valves, fittings and hoses for the control and monitoring of industrial systems in a variety of markets, including the Semiconductor market. These products are primarily used in ultra clean gas transportation systems for the transmission of liquids and gases. The Company’s primary reason for this acquisition was to broaden UCT’s relevance to the semiconductor equipment market and provide access to a new set of customers in the semiconductor fab infrastructure market. The Company borrowed an additional $355.0 million from its existing Credit Facility to finance the acquisition. See further discussion in Note 7 to the Notes to Condensed Consolidated Financial Statements. In December 2020, the Company announced the acquisition of Ham-Let. The expected cash consideration for the equity valuation at that time was approximately 934.7 million Israeli New Shekel (“ILS”) or $287.1 million in equity value. In order to hedge against the foreign currency fluctuation of the USD against ILS at the settlement date, UCT received Board of Director approval to enter into forward hedge contracts to buy ILS. In January 2021, UCT completed the purchase of forward hedge contracts of 905.8 million ILS to lock in the $283.9 million cash that was delivered at the closing of the Ham-Let acquisition. US GAAP requires the recording of the purchase price of the acquired entity at the spot rate on acquisition date, rather than the cash amount hedged and paid. The variance between the cash paid of $283.9 million and the spot value at acquisition of $273.5 million was a loss of $10.4 million and was recorded in the accompanying Condensed Consolidated Statements of Operations as other income (expense), net for the three and six month periods ended June 25, 2021. The Company has preliminarily allocated the purchase price of Ham-Let to the tangible assets, liabilities, identifiable intangible assets acquired and noncontrolling interest, based on their estimated fair values. The excess of purchase price over the aggregate fair value was recorded as goodwill. Goodwill associated with the acquisition is primarily attributable to the future technology, market presence and knowledgeable and experienced workforce. The fair value assigned to identifiable intangible assets acquired was determined using the income approach taking into account the Company’s consideration of a number of inputs, including an independent third-party analysis that was based upon estimates and assumptions provided by the Company. These estimates and assumptions were determined through established and generally accepted valuation techniques. The estimated fair value of the tangible and intangible assets acquired was allocated at Ham-Let’s acquisition date. The allocation of the purchase price is preliminary pending the completion of various analyses and the finalization of estimates. The primary areas of the preliminary purchase price allocation that are not yet finalized relate to the fair values of certain tangible assets and liabilities, primarily inventories, accounts receivable, property, plant and equipment, operating lease right-of-use assets and related operating lease liabilities, income and other taxes, intangible assets the valuation as soon as practicable, but not later than one year from the acquisition date. While the Company believes that its estimates and assumptions underlying the valuations are reasonable, different estimates and assumptions could result in different valuations assigned to the individual assets acquired, liabilities assumed and noncontrolling interest , and the resulting amount of goodwill. The following table summarizes the preliminary fair values of assets acquired, liabilities assumed and noncontrolling interest at the date of acquisition (in millions): Cash and cash equivalents $ 20.1 Accounts receivable 51.6 Inventories 80.3 Prepaid expenses and other assets 17.3 Property, plant and equipment 52.1 Goodwill 86.1 Purchased intangible assets 124.4 Deferred tax assets 0.8 Operating lease right-of-use assets 27.7 Other non-current assets 2.2 Total assets acquired 462.6 Bank borrowings (5.0 ) Accounts payable (30.8 ) Accrued compensation and related benefits (10.5 ) Other current liabilities (12.4 ) Deferred tax liabilities (12.0 ) Operating lease liabilities (23.8 ) Other liabilities (4.0 ) Total liabilities assumed (98.5 ) Noncontrolling interests (1.2 ) Total consideration transferred $ 362.9 Purchased Useful Life Intangible Assets (In years) (In millions) Customer relationships 10 $ 73.9 IP Knowhow 10-15 35.5 Trade names 5 9.8 Backlog 1 5.2 Total purchased intangible assets $ 124.4 Goodwill is not amortized but is reviewed for impairment at least annually and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The results of operations for the Company for the three and six months ended June 25, 2021 include operating activities for Ham-Let since its acquisition date of March 31, 2021. For the three and six months ended June 25, 2021, net sales of approximately $58.2 million attributable to Ham-Let were included in the consolidated results of operations. For the three and six months ended June 25, 2021, results of operations included charges of $4.6 million attributable to amortization of purchased intangible assets. In addition, deal costs associated with the acquisition of $8.1 million and $9.5 million were included in the results of operations for the three and six months ended June 25, 2021, respectively. Deal costs are included in general and administrative expenses in the Company’s Condensed Consolidated Results of Operations. The following unaudited pro forma consolidated results of operations assume the acquisition was completed as of the beginning of the year of the reporting periods presented. The unaudited pro forma consolidated results of operations for the three and six months ended June 25, 2021 and June 26, 2020 (in millions, except per share amounts) as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 (In millions, except per share amounts) Revenues $ 515.2 $ 391.8 $ 989.1 $ 760.9 Net income $ 23.1 $ 13.1 $ 54.1 $ 4.0 Basic income per share $ 0.53 $ 0.33 $ 1.29 $ 0.10 Diluted income per share $ 0.52 $ 0.32 $ 1.26 $ 0.10 The unaudited pro forma results above include adjustments related to the purchase price allocation and financing of the acquisition, primarily to increase amortization for the identifiable intangible assets, to increase interest expense for the additional debt incurred to complete the acquisition, and to reflect the related income tax effect. The unaudited pro forma results for the three and six months ended June 26, 2020 include acquisition related costs of $14.9 million which are not expected to occur in future quarters. Dynamic Manufacturing Solutions, LLC On April 15, 2019, the Company purchased substantially all of the assets of DMS, a semiconductor weldment and solutions provider based in Austin, Texas. Pursuant to the purchase agreement, the former owners of DMS were entitled to receive up to $12.5 million of potential cash earn-out if the combined weldment business, after the acquisition, achieved certain gross profit and gross margin targets for the twelve months ending June 26, 2020. During the second quarter of fiscal year 2020, DMS achieved the specified performance target of the earn-out, which resulted in the maximum payment of $12.5 million paid in August 2020. In the first quarter of fiscal year 2020, the Company completed the acquisition accounting and the valuation of the fair value of the assets acquired and the liabilities assumed

Balance Sheet Information

Balance Sheet Information	6 Months Ended
	Jun. 25, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Information	3. BALANCE SHEET INFORMATION Inventories consisted of the following: June 25, December 25, (In millions) 2021 2020 Raw materials $ 155.7 $ 102.9 Work in process 89.6 64.5 Finished goods 56.7 13.0 Total $ 302.0 $ 180.4 Property, plant and equipment, net, consisted of the following: Useful Life June 25, December 25, (In millions) (in years) 2021 2020 Land $ 4.8 $ 3.8 Buildings 50 39.5 37.2 Machinery and equipment 5-10 115.0 73.8 Leasehold improvements * 53.2 46.7 Computer equipment and software 3-10 48.1 42.5 Furniture and fixtures 5 4.9 4.4 265.5 208.4 Accumulated depreciation (97.0 ) (84.0 ) Construction in progress 49.8 34.8 Total $ 218.3 $ 159.2 * Lesser of estimated useful life or remaining lease term Restructuring During the first quarter of fiscal year 2020, the Company made a strategic decision to fully integrate Quantum Global Technologies, LLC’s (“QGT”) general and administrative expense, Insurance Proceeds In September 2018, a fire in a facility owned by Cinos Korea destroyed certain assets, including equipment, the building and inventory owned by one of its customers. During the first fiscal quarter of 2021, the Company received final insurance proceeds related to the Cinos fire of $7.3 million, which was recorded for the six months ended June 26, 2021 in the accompanying Condensed Consolidated Statements of Operations as other income (expense), net. No insurance proceeds were received in the comparable period in the prior year.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 25, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. FAIR VALUE MEASUREMENTS The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The following table summarizes, for assets or liabilities measured at fair value, the respective fair value and the classification by level of input within the fair value hierarchy: Fair Value Measurement at Reporting Date Using Description June 25, 2021 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In millions) Prepaid expenses and other: Forward contracts $ 0.1 $ — $ 0.1 $ — Other non-current assets: Purchase option $ 1.1 $ — $ — $ 1.1 Other liabilities: Common stock purchase obligation $ 14.0 $ — $ — $ 14.0 Pension obligation $ 5.5 $ — $ — $ 5.5 Fair Value Measurement at Reporting Date Using Description December 25, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In millions) Prepaid expenses and other: Forward contracts $ 1.1 $ — $ 1.1 $ — Other liabilities: Common stock purchase obligation $ 12.6 $ — $ — $ 12.6 Pension obligation $ 4.7 $ — $ — $ 4.7 The estimated fair value of foreign currency forward contracts is based upon quoted market prices obtained from independent pricing services for similar derivative contracts and these financial instruments are characterized as Level 2 assets in the fair value hierarchy. A wholly-owned subsidiary of Ham-Let owns 70.0% interest in Rovac with an option to acquire the remaining 30.0% ownership interest. The fair value of the purchase option recorded in the Company’s financial statements was determined using the Black Scholes option pricing model which utilizes the stock price of Rovac, volatility, expected life and risk-free interest rate based on the implied yield available on U.S. Treasury Securities with a maturity equivalent to the purchase option’s expected life. These assumptions were developed during the valuation process resulting in a Level 3 classification The estimated fair value of the common stock purchase obligation is based on a combination of an income and market valuation approach. The income and market valuation approaches may incorporate Level 3 fair value measures for instances when observable inputs are not available. The more significant judgmental assumptions used to estimate the value of the common stock purchase obligation include an estimated discount rate, a range of assumptions that form the basis of the expected future net cash flows (e.g., the revenue growth rates and operating margins), and a company specific beta. The significant judgmental assumptions used that incorporate market data, including the relative weighting of market observable information and the comparability of that information in the valuation models, are forward-looking and could be affected by future economic and market conditions. The estimated fair value of the pension obligation is based on expected years of service and average compensation. The valuation model used to value the pension obligation utilizes mortality rate, inflation, interest rate risks and changes in the life expectancy for pensioners. These assumptions are routinely made in the appraisal process by the independent actuary thus resulted in a Level 3 classification. There were no transfers from Level 1 or Level 2. Fair value adjustments were noncash, and therefore did not impact the Company’s liquidity or capital resources. Qualitative information about Level 3 fair value measurements is as follows: June 25, Valuation Unobservable 2021 Techniques Input Range/Multiple (Dollars in millions, except rate/multiple) Purchase option $ 1.1 Black‑Scholes option-pricing model Volatility 65.0 % Risk free interest rate 0.03 % Stock price $ 1.2 Strike price $ 0.1 Common stock purchase obligation $ 14.0 Discounted cash flow Revenue multiple 1.3 - 1.5 EBITDA Multiple 4.5 - 7.4 Discount rate 15.0% - 20.0% Pension obligation $ 5.5 Projected unit credit method Discount rate 2.1 % Rate on return 2.5 % Salary increase rate 4.0 % Following is a summary of the Level 3 activity: (In millions) Purchase option Common stock purchase obligation Pension obligation As of December 25, 2020 $ — $ 12.6 $ 4.7 Fair value adjustments — 1.4 0.8 Acquisition of Ham-Let 1.1 — — As of June 25, 2021 $ 1.1 $ 14.0 $ 5.5

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 25, 2021
Financial Instruments Disclosures [Abstract]
Financial Instruments	5. FINANCIAL INSTRUMENTS Derivative Financial Instruments The Company utilizes foreign currency forward contracts to reduce the risk that its cash flows and earnings will be adversely affected by foreign currency exchange rate fluctuations Non-Designated Derivatives The Company uses foreign currency contracts to economically hedge the functional currency equivalent cash flows of non-U.S. dollar- denominated acquisitions. The change in fair value of these derivatives is recorded through earnings in other income (expense), net. The Company records all derivatives in the Condensed Consolidated Balance Sheets at fair value. The Company’s accounting treatment for these derivative instruments is based on its hedge designation. The following tables show the Company’s derivative instruments at gross fair value as of June 25, 2021 and December 25, 2020. June 25, 2021 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total (In millions) Location Hedge Instruments Hedge Instruments Fair Value Derivative liabilities: Level 2: Forward contracts Prepaid expenses and other $ 0.1 $ — $ 0.1 December 25, 2020 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total (In millions) Location Hedge Instruments Hedge Instruments Fair Value Derivative assets Level 2: Forward contracts Prepaid expenses and other $ — $ 1.1 $ 1.1 The effect of derivative instruments in cash flow hedging relationships on income and other comprehensive income (OCI) is summarized below: Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion) Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions) 2021 2020 2021 2020 Derivatives in Cash Flow Hedging Relationship Forward contracts $ 0.6 $ — $ (0.1 ) $ — The amount of gain or loss reclassified from accumulated OCI into income is not significant for the three and six months ended June 25, 2021 and for the three and six months ended June 26, 2020. Losses Recognized in Income on Derivatives Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions) Income Statement Location 2021 2020 2021 2020 Derivatives Not Designated As Hedging Instruments Forward contracts Other income (expense), net $ - $ — $ (11.6 ) $ — In 2020, the Company entered into multiple foreign currency contracts to hedge the functional currency equivalent cash flows related to the non-U.S. dollar-denominated acquisition price of Ham-Let

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 25, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. GOODWILL AND INTANGIBLE ASSETS The Company’s methodology for allocating the purchase price relating to an acquisition is determined through established and generally accepted valuation techniques. Goodwill is measured as the excess of the consideration transferred over the sum of the amounts assigned to tangible and identifiable intangible assets acquired less liabilities assumed. Goodwill and purchased intangible assets with indefinite useful lives are not amortized, but are reviewed for impairment at least annually and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. To test goodwill for impairment, the Company first performs a qualitative assessment to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If the Company concludes it is more likely than not that the fair value of a reporting unit exceeds its carrying amount, the Company does not proceed to perform a quantitative impairment test. If the Company concludes it is more likely than not that the fair value of the reporting unit is less than its carrying value, a quantitative goodwill impairment test will be performed by comparing the fair value of each reporting unit to its carrying value. A quantitative impairment analysis, if necessary, considers the income approach, which requires estimates of the present value of expected future cash flows to determine a reporting unit’s fair value. Significant estimates include revenue growth rates and operating margins used to calculate projected future cash flows, discount rates, and future economic and market conditions. A goodwill impairment charge is recognized for the amount by which the reporting unit’s fair value is less than its carrying value. Any loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The process of evaluating the potential impairment of goodwill and intangible assets requires significant judgment. The Company regularly monitors current business conditions and other factors including, but not limited to, adverse industry or economic trends and lower projections of profitability that may impact future operating results. Details of aggregate goodwill of the Company are as follows: (In millions) Products Services Total Balance at December 25, 2020 $ 97.6 $ 73.5 $ 171.1 Acquisition of Ham-Let 86.1 — 86.1 Balance at June 25, 2021 $ 183.7 $ 73.5 $ 257.2 Intangible Assets Intangible assets are generally recorded in connection with a business acquisition. The Company evaluates the useful lives of its intangible assets each reporting period to determine whether events and circumstances require revising the remaining period of amortization. In addition, the Company reviews indefinite lived intangible assets for impairment when events or changes in circumstances indicate their carrying value may not be recoverable and tests definite lived intangible assets at least annually for impairment. Management considers such indicators as significant differences in product demand from the estimates, changes in the competitive and economic environment, technological advances, and changes in cost structure. Details of intangible assets were as follows: As of June 25, 2021 As of December 25, 2020 Gross Gross Useful Life Carrying Accumulated Carrying Carrying Accumulated Carrying (Dollars in millions) (in years) Amount Amortization Value Amount Amortization Value Customer relationships 6 - 10 $ 193.3 $ (57.9 ) $ 135.4 $ 119.4 $ (50.6 ) $ 68.8 Tradename 4 - 6* 36.8 (14.1 ) 22.7 27.0 (11.7 ) 15.3 Intellectual property/know-how 7 - 15 49.4 (11.1 ) 38.3 13.9 (9.8 ) 4.1 Recipes 20 73.2 (10.4 ) 62.8 73.2 (8.5 ) 64.7 Standard operating procedures 20 8.6 (1.2 ) 7.4 8.6 (1.0 ) 7.6 Backlog 1 5.2 (1.3 ) 3.9 — — — Total $ 366.5 $ (96.0 ) $ 270.5 $ 242.1 $ (81.6 ) $ 160.5 * The Company concluded that the asset life of the UCT tradename of $9.0 million is indefinite and is therefore not amortized but is reviewed for impairment at least annually and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The Company amortizes its intangible assets on a straight-line or accelerated basis over the estimated economic life of the assets. Amortization expense was approximately $9.5 million and $14.4 million for the three and six months ended June 25, 2021, respectively, and $4.9 million and $9.9 million for the three and six months ended June 26, 2020, respectively. Amortization expense related to recipes, standard operating procedures and certain intellectual property/know-how is charged to cost of revenues and the remainder is charged to general and administrative expense. As of June 25, 2021, future estimated amortization expense is expected to be as follows: Amortization (In millions) Expense 2021 (remaining in year) $ 19.0 2022 33.4 2023 26.4 2024 25.5 2025 23.2 Thereafter 134.0 Total $ 261.5

Borrowing Arrangements

Borrowing Arrangements	6 Months Ended
	Jun. 25, 2021
Debt Disclosure [Abstract]
Borrowing Arrangements	7. BORROWING ARRANGEMENTS In August 2018, the Company entered into a credit agreement with Barclays Bank that provided a Term Loan, a Revolving Credit Facility, and a Letter of Credit Facility (the “Credit Facility”). UCT and certain of its subsidiaries have agreed to secure all of their obligations under the Credit Facility by granting a first priority lien in substantially all of their respective personal property assets (subject to certain exceptions and limitations). In August 2018, the Company borrowed $350.0 million under the Term Loan and used the proceeds, together with cash on hand, to finance the acquisition of QGT and to refinance its previous credit facilities. On March 31, 2021, the Company entered into a Second Amendment (the “Second Amendment”) to the Credit Facility to, among other things, (i) refinance and reprice its approximately $272.8 million of existing term B borrowings that will remain outstanding (the “Repricing”) and (ii) obtain a $355.0 million senior secured incremental term loan B facility (the “Incremental Term Loan”) with Barclays Bank, which increased the amount of term loan indebtedness outstanding under the Company’s Credit Facility. The Term Loan has a maturity date of August 27, 2025, with monthly interest payments in arrears, quarterly principal payments of 0.625% of the outstanding principal balance thereof as of March 31, 2021, with the remaining principal paid upon maturity. Under the Credit Agreement, the Company may elect that the term loans bear interest at a rate per annum equal to either (a) “ABR” (as defined in the Credit Agreement), plus the applicable margin or (b) the “Eurodollar Rate” (as defined in the Credit Agreement), based on LIBOR, plus the applicable margin. The applicable margin for the term loan under the Credit Agreement is equal to a rate per annum to either (i) at any time that the Company’s corporate family rating is Ba3 (with a stable outlook) or higher from Moody’s and BB- (with a stable outlook) or higher from S&P, (x) 3.50% for such Eurodollar term loans and (y) 2.50% for such ABR term loans or (ii) at all other times, (x) 3.75% for such Eurodollar term loans and (y) 2.75% for such ABR term loans. Interest on the term loans is payable on (1) in the case of such ABR term loans, the last day of each calendar quarter and (2) in the case of such Eurodollar term loans, the last day of each relevant interest period and, in the case of any interest period longer than three months, on each successive date three months after the first day of such interest period. On March 29, 2021, the Company elected that the term loan outstanding as of March 31, 2021 accrue interest based on the “Eurodollar Rate” for an initial interest period of one month. As of March 31, 2021, the applicable margin with respect to the term loan facility was 3.75%. Pursuant to the Second Amendment to the Credit Agreement made effective on March 31, 2021, the Credit Agreement contains customary LIBOR replacement provisions in the event LIBOR is discontinued. At June 25, 2021 June 25, 2021 The Revolving Credit Facility has an initial available commitment of $65.0 million and a maturity date of August 27, 2023. The Company pays a quarterly commitment fee in arrears equal to 0.25% of the average daily available commitment outstanding. The Credit Agreement requires the Company to maintain certain financial covenants including a consolidated fixed charge coverage ratio (as defined in the New Credit Agreement) as of the last day of any fiscal quarter of at least 1.25 to 1.00, and a consolidated leverage ratio (as defined in the Credit Agreement) as of the last day of any fiscal quarter of no greater than 3.75 to 1.00. The Company was in compliance with all financial covenants as of the quarter ended June 25, 2021 The Letter of Credit Facility has an initial available commitment of $50.0 million and a maturity date of August 27, 2023. The Company pays quarterly in arrears a fee equal to 2.5% (subject to certain adjustments as per the Term Loans) of the dollar equivalent of all outstanding letters of credit, and a fronting fee equal to 0.125% of the undrawn and unexpired amount of each letter of credit. As of June 25, 2021 In 2020, Cinos China amended its existing Credit Agreement and entered into two additional Credit Agreements with a local bank that provide Revolving Credit Facilities for a total available commitment of $3.5 million with various maturity dates through September 23, 2022 and interest rates ranging from 2.0% to 4.1%. As of June 25, 2021, Cinos China had outstanding debt of $ 2.7 million with an average interest rate of 3.1% under these Credit Agreements. Cinos Korea has a Credit Agreement that provides a Revolving Credit Facility for a total available commitment of 0.6 billion Korean Won (approximately $0.5 million) with annual renewals beginning June 2022 with an interest rate of 2.9%. During the six months ended June 26, 2020, borrowings under the Revolving Credit Facility were insignificant and no debt was outstanding as of June 25, 2021. UCT Fluid Delivery Solutions s.r.o. has a credit agreement with a local bank in the Czech Republic that provides for a revolving credit facility in the aggregate of up to 6.0 million euros. As of June 25, 2021 Ham-Let has credit facilities and other loan agreements with various financial institutions. As of June 25, 2021, Ham-Let had $8.4 million of outstanding debt with interest rates ranging from 1.8% to 4.6%. As of June 25, 2021 June 25, 2021 million, $9.8 million and $0.8 million The fair value of the Company’s long-term debt was based on Level 2 inputs, and fair value was determined using quoted prices for similar liabilities in inactive markets. The Company’s carrying value approximates fair value for the Company’s long-term debt.

Income Tax

Income Tax	6 Months Ended
	Jun. 25, 2021
Income Tax Disclosure [Abstract]
Income Tax	8. INCOME TAX The Company's effective tax rate was 25.6% and 20.5% for the three months ended June 25, 2021 and June 26, 2020, respectively, and 23.2% and 23.8% for the six months ended June 25, 2021 and June 26, 2020. The Company’s income tax provision The change in respective rates reflects, primarily, changes in the geographic mix of worldwide earnings and financial results in jurisdictions which are taxed at different rates and the impact of losses in jurisdictions with full federal and state valuation allowances. Company management continuously evaluates the need for a valuation allowance and, as of June 25, 2021, concluded that a full valuation allowance on its U.S. federal and state deferred tax assets was still appropriate. The Company provides for U.S. income taxes on the earnings of its foreign subsidiaries to the extent required by the Tax Cuts and Jobs Act (TCJA). In a prior period, the Company has also recognized a deferred tax liability for taxes that would be withheld on a distribution of a portion of the undistributed earnings of one of its China subsidiaries. However, the Company has not provided for withholding taxes on the remaining portion of the undistributed earnings of its China subsidiary nor for the undistributed earnings of its other foreign subsidiaries that it intends to reinvest indefinitely outside the U.S. The Company has also historically remitted earnings from its Singapore subsidiary to the U.S. and may do so again in the future. However, the Company has not provided for withholding taxes on undistributed Singapore earnings as Singapore does not currently impose a withholding tax on dividends. If the Company changes its intent to reinvest its undistributed foreign earnings indefinitely or if a greater amount of undistributed earnings is needed than the previous anticipated remaining unremitted foreign earnings, the Company could be required to accrue or pay foreign taxes on some or all of these undistributed earnings. As of June 25, 2021, the Company had undistributed earnings of foreign subsidiaries that are considered indefinitely invested outside of the U.S. of approximately $317.3 million. It is not practicable to determine the tax liability that might be incurred if these earnings were to be distributed. As of June 25, 2021 On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (the CARES Act) was signed into law in response to the U.S. COVID-19 pandemic, which, among other things, suspends the 80.0% limitation on the deduction for NOLs in taxable years beginning before January 1, 2021, permits a 5-year On December 27, 2020, the U.S. government enacted the Consolidated Appropriations Act On March 11, 2021, the American Rescue Plan Act of 2021 (“American Rescue Plan”) was signed into law to provide additional relief in connection with the ongoing COVID-19 pandemic. The American Rescue Plan includes, among other things, provisions relating to Paycheck Protection Plan (“PPP”) loan expansion, defined pension contributions, excessive employee remuneration, and the repeal of the election to allocate interest expense on a worldwide basis. The Company does not currently expect that such provisions will have a material impact on the Company’s Condensed Consolidated Financial Statements. In December 2019, the FASB issued Accounting Standards Update No. 2019-12, “Income Taxes (Topic 740) Simplifying the Accounting for Income Taxes”, as part of its initiative to reduce complexity in the accounting standards. The ASU eliminates certain exceptions from ASC 740 related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also clarifies and simplifies other aspects of the accounting for income taxes. The guidance is effective for fiscal years beginning after December 15, 2020 and for interim periods within those fiscal years. The Company adopted ASU 2019-12 on January 1, 2021. The adoption of this standard did not have a material impact on the Company’s Condensed Consolidated Financial Statements.

Retirement Plans

Retirement Plans	6 Months Ended
	Jun. 25, 2021
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	9. RETIREMENT PLANS Defined Benefit Plan Cinos Korea has a noncontributory defined benefit pension plan covering substantially all of its employees upon their retirement. The benefits are based on expected years of service and average compensation. The net period costs are recognized as employees render the services necessary to earn the postretirement benefits. The Company records annual amounts relating to the pension plan based on calculations that incorporate various actuarial and other assumptions, including discount rates, mortality, assumed rates of return, compensation increases and turnover rates. The Company reviews its assumptions on an annual basis and makes modifications to the assumptions based on current and expected rates of return and trends when it is appropriate to do so. The effect of modifications to those assumptions is recorded in accumulated other comprehensive income and amortized to net periodic cost over future periods using the corridor method. The Company believes that the assumptions utilized in recording its obligations under the plan are reasonable based on its experience and market conditions. As of June 25, 2021 June 25, 2021 June 25, 2021 June 25, 2021 Employee Savings and Retirement Plan The Company sponsors a 401(k) savings and retirement plan (the “401(k) Plan”) for all U.S. employees who meet certain eligibility requirements. Participants can elect to contribute to the 401(k) Plan, on a pre-tax basis, up to 25% of their salary to a maximum of the IRS limit. The Company matches 50.0% of participant salary up to 6.0% of employee contributions based upon eligibility. The Company made approximately $0.6 million and $1.2 million discretionary employer contributions to the 401(k) Plan in the three and six months ended June 25, 2021 and $0.7 million and $1.3 million for the three and six months ended June 26, 2020, respectively.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 25, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. COMMITMENTS AND CONTINGENCIES Commitment The Company had commitments to various third parties to purchase inventories totaling approximately $405.1 million as of June 25, 2021. Contingency From time to time, the Company is subject to various legal proceedings and claims, either asserted or unasserted, that arise in the ordinary course of business. Although the outcome of the various legal proceedings and claims individually or in the aggregate cannot be predicted with certainty, the Company has not had a history of outcomes to date that have been material to the Condensed Consolidated Statements of Operations and does not believe that any of these proceedings or other claims will have a material adverse effect on its consolidated financial condition, results of operations or cash flows.

Stockholders' Equity and Noncon

Stockholders' Equity and Noncontrolling Interests	6 Months Ended
	Jun. 25, 2021
Noncontrolling Interest [Abstract]
Stockholders' Equity and Noncontrolling Interests	11. STOCKHOLDERS’ EQUITY AND NONCONTROLLING INTERESTS Equity Financings On April 13, 2021, the Company completed an underwritten public offering of 3,181,818 shares of the Company’s common stock, for which the Company received net proceeds of approximately $167.6 million, after deducting the underwriting discounts and offering expenses payable by the Company. On April 29, 2021, the Underwriters exercised the option to purchase an additional 477,272 shares of the Company’s common stock for approximately $25.2 million in cash. Noncontrolling Interests QGT, through its wholly-owned subsidiary in Singapore, The carrying value of the remaining interest held by another shareholder in Cinos Korea and the remaining interest in Cinos China are presented as noncontrolling interests in the accompanying Condensed Consolidated Financial Statements. The fair values of the noncontrolling interests were estimated based on the values of Cinos Korea and Cinos China on a 100.0% basis. The values were calculated based on the pro-rata portion of total QGT earnings before interest expense, taxes, depreciation and amortization contributed by each entity. The Company is obligated to purchase shares owned by a Cinos Korea shareholder. As of June 25, 2021, the fair value of the obligation is $14.0 million which has been recorded as a non-current liability in the accompanying consolidated balance sheets and represents a Level 3 measurement as discussed in Note 4 of the Company’s Notes to Condensed Consolidated Financial Statements. On July 24, 2021, the Company entered into an amendment with the Cinos Korea shareholder to eliminate the obligation to purchase certain amount of the common stock owned by the shareholder. As a result, noncontrolling interest in Cinos Korea would increase by 35.0% beginning in the third quarter of fiscal 2021.

Employee Stock Plans

Employee Stock Plans	6 Months Ended
	Jun. 25, 2021
Postemployment Benefits [Abstract]
Employee Stock Plans	12. EMPLOYEE The Company grants stock awards in the form of restricted stock units (RSUs) and performance stock units (PSUs) to its employees as part of the Company’s long-term equity compensation plan. These stock awards are granted to employees with a unit purchase price of zero dollars and typically vest over three years, subject to the employee’s continued service with the Company and, in the case of PSUs, subject to achieving certain performance goals. The Company also grants common stock to its board members in the form of restricted share awards (RSAs), which vest on the earlier of 1) the next Annual Shareholder Meeting, or 2) 365 days from date of grant. Stock-based compensation expense includes compensation costs related to estimated fair values of awards granted. The estimated fair value of the Company’s equity-based awards, net of expected forfeitures, is amortized on a straight-line basis over the awards’ vesting period and is adjusted for subsequent changes in estimated forfeitures related to all equity-based awards and performance as it relates to PSUs. The following table shows the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions) 2021 2020 2021 2020 Cost of revenues (1) $ 0.4 $ 0.5 $ 0.9 $ 1.0 Research and development - 0.1 0.1 0.1 Sales and marketing 0.4 0.3 0.7 0.6 General and administrative 2.9 2.2 5.5 4.5 3.7 3.1 7.2 6.2 Income tax benefit (0.9 ) (0.6 ) (1.7 ) (1.5 ) Stock-based compensation expense, net of tax $ 2.8 $ 2.5 $ 5.5 $ 4.7 (1) Stock-based compensation expense capitalized in inventory for the three and six months ended June 25, 2021 and June 26, 2020was not significant. For purposes of determining compensation expense related to these RSUs, the fair value is determined based on the closing market price of the Company’s common stock on the date of award. There were 0.3 million RSUs granted during the quarter ended June 25, 2021, with a weighted average fair value of $49.86 per share. For the six months ended June 26, 2020, 0.4 million RSUs were granted with a weighted average fair value of $49.02 per share. For the , 0.1 million vested shares were withheld to satisfy withholding tax obligations, resulting in the net issuance of 0.5 million shares. As of June 25, 2021, approximately $26.0 million of stock-based compensation cost, net of estimated forfeitures, related to RSUs and PSUs remains to be amortized over a weighted average period of 1.7 years. As of June 25, 2021, a total of 1.4 million RSUs and PSUs remain outstanding with an aggregate intrinsic value of $75.6 million and a weighted average remaining contractual term of 1.3 year As of June 25, 2021, a total of 18,893 shares of RSAs were outstanding. The total unamortized expense of the Company’s unvested restricted stock awards as of June 25, 2021 was $0.8 million. The following table summarizes the Company’s combined RSU, PSU and RSA activity for the six months ended June 26, 2020: (In millions) Shares Aggregate Fair Unvested RSUs, PSUs and RSAs at December 25, 2020 1.7 $ 54.1 Granted 0.4 Vested (0.6 ) Forfeited (0.1 ) Unvested RSUs, PSUs and RSAs as of June 25, 2021 1.4 $ 76.6 Vested and expected to vest RSUs, PSUs and RSAs as of June 25, 2021 1.3 $ 67.4

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 25, 2021
Revenue From Contract With Customer [Abstract]
Revenue Recognition	13. REVENUE RECOGNITION Revenue is recognized when control of the promised goods or services is transferred to the Company’s customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The Company sells its products and services primarily to customers in the semiconductor capital equipment industry. The Company’s revenues are highly concentrated, and we are therefore highly dependent upon a small number of customers. Typical payment terms with our customers range from thirty to sixty days. The Company’s Products division provides warranty on its products for a period of up to two years and provides for warranty costs at the time of sale based on historical activity. Determination of the warranty reserve requires the Company to make estimates of product return rates and expected costs to repair or replace the products under warranty. If actual return rates and/or repair and replacement costs differ significantly from these estimates, adjustments to recognize additional cost of revenues may be required in future periods. The warranty reserve is included in other current liabilities on the Condensed Consolidated Balance Sheets and is not considered significant. The Company’s products are manufactured and services provided at facilities throughout the Americas, Asia Pacific and EMEA (“Europe and the Middle East”). Sales to customers are initiated through a purchase order and are governed by our standard terms and conditions, written agreements, or both. Revenue is recognized when performance obligations under the terms of an agreement with a customer are satisfied; generally, this occurs with the transfer of control of the products or when the Company provides the services. Transfer of control occurs at a specific point-in-time. Based on the enforceable rights included in our agreements or prevailing terms and conditions, products produced by the Company without an alternative use are not protected by an enforceable right of payment that includes a reasonable profit throughout the duration of the agreement. Consignment sales are recognized in revenue at the earlier of the period that the goods are consumed or after a period of time subsequent to receipt by the customer as specified by terms of the agreement, provided control of the promised goods or services has transferred. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring Products or providing services. Sales, value-add, and other taxes we collect concurrent with revenue-producing activities are excluded from revenue. Certain of our customers may receive cash-based incentives, such as rebates or credits, which are accounted for as variable consideration. We estimate these amounts based on the expected amount to be provided to customers and reduce revenues recognized. As of June 25, 2021 rebates of $5.7 million for both periods The Company’s principal markets include America, Asia Pacific and EMEA . R evenues by geographic area are categorized based on the customer’s location to which the products were shipped or where the services were performed. The following table sets forth revenue by geographic area (in millions): Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 United States $ 187.3 $ 155.1 $ 359.9 $ 297.7 Singapore 182.5 119.6 335.8 231.8 South Korea 36.7 21.3 63.3 41.6 China 25.4 12.0 41.4 21.1 Taiwan 23.1 15.0 43.3 30.2 Austria 20.6 13.0 39.3 27.5 Israel 5.4 4.2 9.4 7.9 Other 34.2 4.6 40.4 7.9 $ 515.2 $ 344.8 $ 932.8 $ 665.7

Leases

Leases	6 Months Ended
	Jun. 25, 2021
Leases [Abstract]
Leases	14. LEASES The Company leases offices, facilities and equipment in locations throughout the Americas, Asia Pacific and EMEA The Company’s leases do not provide an implicit rate, thus the Company uses an estimated incremental borrowing rate in determining the present value of lease payments. The components of lease expense were summarized as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (Dollars in millions) 2021 2020 2021 2020 Operating lease cost $ 4.8 $ 3.4 $ 8.5 $ 6.6 Short-term lease cost 0.5 0.3 0.9 0.6 Total lease cost $ 5.3 $ 3.7 $ 9.4 $ 7.2 Operating cash flows from operating leases $ 5.5 $ 4.4 $ 9.2 $ 8.8 Weighted-average remaining lease term – operating leases 1.8 2.2 Weighted-average discount rate – operating leases 5.1 % 5.5 % Future minimum payments under operating leases as of June 25, 2021 were summarized as follows: (In millions) Operating Leases 2021 remaining $ 9.3 2022 17.4 2023 14.4 2024 11.0 2025 8.1 Thereafter 22.3 Total minimum lease payments 82.5 Less: imputed interest 12.2 Lease liability $ 70.3 The Company assumed $23.8 million of facility leases as part of the acquisition of Ham-Let. The Company also entered into two new lease agreements in fiscal year 2020 with commencement dates in fiscal year 2021. The total minimum lease payments for these two new lease agreements is $22.1 million, which was included in the total contractual obligations

Net Income Per Share

Net Income Per Share	6 Months Ended
	Jun. 25, 2021
Earnings Per Share [Abstract]
Net Income Per Share	15. NET INCOME PER SHARE The following is a reconciliation of the numerators and denominators used in computing basic and diluted net income (loss) per share: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions, except share amounts) 2021 2020 2021 2020 Numerator: Net income attributable to UCT $ 17.1 $ 21.3 $ 42.1 $ 30.7 Denominator: Shares used in computation — basic: Weighted average common shares outstanding 43.3 40.1 41.9 39.9 Shares used in computation — diluted: Weighted average common shares outstanding 43.3 40.1 41.9 39.9 Dilutive effect of common shares outstanding subject to repurchase 1.0 0.7 1.0 0.9 Shares used in computing diluted net income per share 44.3 40.8 42.9 40.8 Net income per share attributable to UCT — basic $ 0.39 $ 0.53 $ 1.00 $ 0.77 Net income per share attributable to UCT — diluted $ 0.39 $ 0.52 $ 0.98 $ 0.75

Reportable Segments

Reportable Segments	6 Months Ended
	Jun. 25, 2021
Segment Reporting [Abstract]
Reportable Segments	16. REPORTABLE SEGMENTS The Company operates and reports financial results for two operating segments: Products and Services. These segments are organized primarily by the nature of the products and service they provide. The Company’s Chief Executive Officer (chief operating decision maker) views and evaluates operations based on the results of each of the reportable segments. The following table describes each segment: Segment Product or Services Markets Served Geographic Areas Products Assembly Weldments Machining Fabrication Components Semiconductor Americas Asia Pacific EMEA Services Cleaning Analytics Semiconductor Americas Asia Pacific EMEA The Company uses segment profit or loss as the primary measure of profitability to evaluate operating performance and to allocate capital resources. Segment profit or loss is defined as a segment’s income or loss from continuing operations before other income and income taxes included in the accompanying condensed consolidated statements of operations. Any intercompany sales and associated profit (and any other intercompany items) are eliminated from segment results. There were no significant intercompany eliminations for the periods presented. Segment Data Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 Revenues: Products $ 442.5 $ 277.9 $ 788.1 $ 537.3 Services 72.7 66.9 144.7 128.4 Total segment revenues $ 515.2 $ 344.8 $ 932.8 $ 665.7 Gross profit: Products $ 74.6 $ 48.6 $ 136.6 $ 93.3 Services 25.3 25.3 50.2 46.3 Total segment gross profit $ 99.9 $ 73.9 $ 186.8 $ 139.6 Operating profit: Products $ 24.0 $ 24.3 $ 58.2 $ 44.6 Services 7.9 6.5 14.1 8.8 Consolidated income from operations $ 31.9 $ 30.8 $ 72.3 $ 53.4 June 25, December 25, 2021 2020 Assets Products $ 1,597.1 $ 868.4 Services 249.6 234.1 Total segment assets $ 1,846.7 $ 1,102.5 As of June 25, 2021, approximately $111.6 million and $46.7 million of the Company’s net long-lived assets were located in Asia Pacific and EMEA, respectively, and the remaining balances were located in the United States. At December 25, 2020, approximately $90.4 million and $9.4 million of the Company’s net long-lived assets were located in Asia and Europe, respectively, and the remaining balances were located in the United States.

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 25, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation — The unaudited Condensed Consolidated Financial Statements included in this quarterly report on Form 10-Q include the accounts of the Company and its majority-owned subsidiaries and have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). This financial information reflects all adjustments which are, in the opinion of the Company, normal, recurring and necessary for the fair financial statement presentation for the dates and periods presented. Certain information and footnote disclosures normally included in our annual financial statements, prepared in accordance with GAAP, have been condensed or omitted. The Company’s December 25, 2020 balance sheet data were derived from its audited financial statements as of that date.
Fiscal Year	Fiscal Year — The Company uses a 52-53 week fiscal year ending on the Friday nearest December 31. All references to quarters refer to fiscal quarters and all references to years refer to fiscal years.
Principles of Consolidation	Principles of Consolidation — The Company’s Condensed Consolidated Financial Statements include the accounts of the Company and its majority-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated upon consolidation.
Noncontrolling interests	Noncontrolling interests — Noncontrolling interests are recognized to reflect the portion of the equity of the majority-owned subsidiaries which is not attributable, directly or indirectly, to the controlling stockholder. The Company’s consolidated entities include partially-owned entities, which are (1) Cinos Co., Ltd (“Cinos Korea”), a South Korean company that provides outsourced cleaning and recycling of precision parts for the semiconductor industry through its operating facilities in South Korea, (2) Cinos Xian Clean Technology, Ltd. (“Cinos China”), a Chinese entity that is partially owned by Cinos Korea and (3) Rovac Pte, Ltd (“Rovac”), a Singaporean Company that is majority owned by Ham-Let. The interest held by others in Cinos Korea, in Cinos China and in Rovac are presented as noncontrolling interests in the accompanying Condensed Consolidated Financial Statements. The noncontrolling interests will continue to be attributed its share of gains and losses even if that attribution results in a deficit noncontrolling interests’ balance.
Segments	Segments — The Financial Accounting Standards Board’s (“FASB”) guidance regarding disclosure about segments in an enterprise and related information establishes standards for the reporting by public business enterprises of information about reportable segments, products and services, geographic areas, and major customers. The method for determining what information to report is based on the manner in which management organizes the reportable segments within the Company for making operational decisions and assessments of financial performance. The Company’s chief operating decision-maker is the Chief Executive Officer. The Company operates and reports two segments: Products and Services. Ham-Let’s business activities are similar to Products and, therefore, were included within this segment. See Note 16 of the Notes to the Condensed Consolidated Financial Statements.
Foreign Currency Translation and Remeasurement	Foreign Currency Translation and Remeasurement — The functional currency of the majority of the Products division’s foreign subsidiaries is the U.S. dollar. The functional currency of the Service division’s foreign subsidiaries is the local currency except for that of its Singapore and Scotland entities, which is the U.S. dollar. For the Company’s foreign subsidiaries where the local currency is the functional currency, the Company translates the financial statements of these subsidiaries to U.S. dollars using month-end exchange rates for assets and liabilities, and average exchange rates for revenue, costs and expenses. Translation gains and losses are recorded in accumulated other comprehensive income (AOCI) within UCT stockholders’ equity. For the Company’s foreign subsidiaries where the U.S. dollar is the functional currency, any gains and losses resulting from the translation of the assets and liabilities of these subsidiaries are recorded in other income (expense), net.
Use of Estimates	Use of Estimates — The presentation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Such estimates and assumptions include inventory valuation, accounting for income taxes, business combinations, valuation of goodwill, intangible assets and long-lived assets. The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. However, future events are subject to change and the best estimates and judgments routinely require adjustments. Actual amounts may differ from those estimates.
Cash And Cash Equivalents	Cash and Cash Equivalents — The Company considers currency on hand, demand deposits, time deposits, and all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash and cash equivalents. Cash and cash equivalents are held in various financial institutions in the United States and internationally.
Concentration of Credit Risk	Concentration of Credit Risk — Financial instruments which subject the Company to concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. The Company sells its products and provides services primarily to semiconductor capital equipment manufacturers in the United States. The Company performs credit evaluations of its customers’ financial condition and generally requires no collateral. The Company’s most significant customers (having accounted for 10% or more of revenues) and their related revenues as a percentage of total revenues were as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 Lam Research Corporation 38.3 % 39.6 % 41.6 % 42.0 % Applied Materials, Inc. 24.1 % 25.8 % 23.9 % 24.7 % Total 62.4 % 65.4 % 65.5 % 66.7 % Two customers’ accounts receivable balances, Lam Research Corporation and Applied Materials, Inc., were individually greater than 10% of accounts receivable as of June 25, 2021 Three
Fair Value of Measurements	Fair Value of Measurements — The Company measures its cash equivalents, derivative contracts, contingent earn-out liabilities, pension obligation and common stock purchase obligation at fair value on a recurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset or a liability. Assets and liabilities recorded at fair value are measured and classified in accordance with a three-tier fair value hierarchy based on the observability of the inputs available in the market used to measure fair value: Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 — Inputs that are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant inputs are observable in the market or can be derived from observable market data. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs including interest rate curves, foreign exchange rates, and credit ratings. Level 3 — Unobservable inputs that are supported by little or no market activities.
Derivative Financial Instruments	Derivative Financial Instruments — The Company uses forward contracts to hedge a portion of, but not all, existing and anticipated foreign currency denominated transactions typically expected to occur within 24 months. The purpose of the hedge is to mitigate the effect of exchange rate fluctuations on certain foreign currency denominated costs and eventual cash flows. The Company recognizes derivative instruments as either assets or liabilities in the accompanying Condensed Consolidated Balance Sheets at fair value. The Company records changes in the fair value of the derivatives in the accompanying Condensed Consolidated Statements of Operations as other income (expense), net, or as a component of AOCI in the accompanying Condensed Consolidated Balance Sheets.
Inventories	Inventories — Inventories are stated at the lower of cost (which approximates actual cost on a first-in, first-out basis) or net realizable value. The Company evaluates the valuation of all inventories, including raw materials, work-in-process, finished goods and spare parts on a periodic basis. Obsolete inventory or inventory in excess of management’s estimated usage is written down to its estimated market value less costs to sell, if less than its cost. Inherent in the estimates of market value are management’s estimates related to economic trends, future demand for products, and technological obsolescence of the Company’s products. Inventory write downs inherently involve judgments based on assumptions about expected future demand and the impact of market conditions on those assumptions. Although the Company believes that the assumptions it used in estimating inventory write downs are reasonable, significant changes in any one of the assumptions in the future could produce a significantly different result. There can be no assurances that future events and changing market conditions will not result in significant increases in inventory write downs.
Property, Plant and Equipment, net	Property, Plant and — Property, plant and equipment are stated at cost, or, in the case of equipment under finance leases, the present value of future minimum lease payments at inception of the related lease. The Company also capitalizes interest on borrowings related to eligible capital expenditures. Capitalized interest is added to the cost of the qualified assets and is subject to depreciation. Depreciation and amortization are computed using the straight-line method over the lesser of the estimated useful lives of the assets or the terms of the leases. Useful lives range from three to fifty years ten years
Long-lived Assets	Long-lived Assets — The Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate the carrying value of an asset group may not be recoverable. The Company assesses the fair value of the assets based on the amount of the undiscounted future cash flows that the assets are expected to generate and recognizes an impairment loss when estimated undiscounted future cash flows expected to result from the use of the asset are less than the carrying value of the asset. If the Company identifies an impairment, the Company reduces the carrying value of the group of assets to comparable market values, when available and appropriate, or to its estimated fair value based on a discounted cash flow approach. The Company assessed the useful lives of its long-lived assets, including property, plant and equipment as well as its intangible assets as of June 25, 2021 and concluded that no impairment was required.
Leases	Leases — The Company determines if an arrangement is a lease, or contains a lease, at the inception of the arrangement. When the Company determines the arrangement is a lease, or contains a lease, at lease inception, it then determines whether the lease is an operating lease or a finance lease. Operating and finance leases with lease terms of one year or greater result in the Company recording a right-of-use (ROU) asset and lease liability on its balance sheet. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating and finance lease ROU assets and liabilities are initially recognized based on the present value of lease payments over the lease term. In determining the present value of lease payments, the Company uses the implicit interest rate if readily determinable or when the implicit interest rate is not readily determinable, the Company uses its incremental borrowing rate. The incremental borrowing rate is not a commonly quoted rate and is derived through a combination of inputs including the Company’s credit rating and the impact of full collateralization. The incremental borrowing rate is based on the Company’s collateralized borrowing capabilities over a similar term of the lease payments. The Company utilizes the consolidated group incremental borrowing rate for all leases. The operating lease ROU asset also includes any lease payments made and excludes any lease incentives. Specific lease terms used in computing the ROU assets and lease liabilities may include options to extend or terminate the lease when the Company believes it is reasonably certain that it will exercise that option. Lease expense for operating lease payments is recognized on a straight-line basis over the lease term. As allowed by the guidance, the Company has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases for any class of underlying asset. Operating leases are included in operating lease ROU assets, other current liabilities, and long-term operating lease liabilities on the Company’s consolidated balance sheet. The Company’s finance leases at June 25, 2021 and December 25, 2020 were not significant.
Goodwill and Indefinite Lived Intangible Assets	Goodwill and Indefinite Lived Intangible Assets — Goodwill and indefinite-lived intangible assets are not amortized, but are reviewed for impairment annually. Intangible assets are presented at cost, net of accumulated amortization, and are amortized on either a straight-line method or on an accelerated method over their estimated future discounted cash flows. The Company reviews goodwill and purchased intangible assets with indefinite lives for impairment annually and whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable, such as when reductions in demand or significant economic slowdowns in the semiconductor industry are present.
Deferred Debt Issuance Costs	Deferred Debt Issuance Costs — Debt issuance costs incurred in connection with obtaining debt financing are deferred and presented as a direct deduction from Bank Borrowings in the accompanying Condensed Consolidated Balance Sheets. Deferred costs are amortized on an effective interest method basis over the contractual term.
Defined Benefit Pension Plan	Defined Benefit Pension Plan — The Company has a noncontributory defined benefit pension plan covering substantially all of the employees of one of its foreign entities upon termination of their employee services. For further discussion of the Company’s defined benefit pension plan see Note 9 of the Notes to the Condensed Consolidated Financial Statements.
Revenue Recognition	Revenue Recognition — Revenue is recognized when control of the promised goods or services is transferred to the Company’s customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The Company performs the following five steps to determine when to recognize revenue: (1) identification of the contract(s) with customers, (2) identification of the performance obligations in the contract, (3) determination of the transaction price, (4) allocation of the transaction price to the performance obligations in the contract, and (5) recognition of revenue when, or as, a performance obligation is satisfied. Shipping and Handling Costs — Shipping and handling costs are included as a component of cost of revenues.
Research and Development Costs	Research and Development Costs — Research and development costs are expensed as incurred.
Stock-Based Compensation Expense	Stock-Based Compensation Expense — The Company maintains stock-based compensation plans which allow for the issuance of equity-based awards to executives and certain employees. These equity-based awards include restricted stock awards and restricted stock units. The Company also maintains an employee stock purchase plan (“ESPP”) that provides for the issuance of shares to all eligible employees of the Company at a discounted price.
Government Subsidies	Government Subsidies — Government subsidies are recognized where there is reasonable assurance that the subsidy will be received and all attached conditions will be complied with. When the subsidy relates to an expense item, it is recognized as income on a systematic basis over the periods that the related costs, for which it is intended to compensate, are expensed. When the subsidy relates to an asset, it is recognized as income in equal amounts over the expected useful life of the related asset. When the subsidy does not relate to specific expenses or assets, the income is accounted for in the period where there is reasonable assurance that the subsidy will be received.
Income Taxes	Income Taxes — The Company utilizes the asset and liability method of accounting for income taxes, under which deferred taxes are determined based on the temporary differences between the financial statement and tax basis of assets and liabilities using tax rates expected to be in effect during the years in which the basis differences reverse. Deferred income taxes arise from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements, which will result in taxable or deductible amounts in the future. In evaluating our ability to realize our deferred tax assets within the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies, and results of recent operations. In projecting future taxable income, we begin with historical results and incorporate assumptions about the amount of future federal, state, and foreign pretax operating income adjusted for items that do not have tax consequences. The assumptions about future taxable income require significant judgment and are consistent with the plans and estimates we are using to manage the underlying businesses. In evaluating the objective evidence that historical results provide, we consider recent cumulative income (loss). A valuation allowance is recorded when it is more likely than not that some of the deferred tax assets will not be realized. Income tax positions must meet a more likely than not recognition threshold to be recognized. The Company recognizes tax benefits from uncertain tax positions only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits within the consolidated statements of income as income tax expense. The Company accounts for Global Intangible Low-Taxed Income (“GILTI”) as period costs when incurred.
Net Income per Share	Net Income per Share — Basic net income per share is computed by dividing net income by the weighted average number of shares outstanding for the period. Diluted net income per share is calculated by dividing net income by the weighted average number of common shares outstanding and common equivalent shares from dilutive restricted stock using the treasury stock method, except when such shar es are anti-dilutive. See Note 15 of the Notes to the Condensed Consolidated Financial Statements.
Business Combinations	Business Combinations — The Company recognizes assets acquired (including goodwill and identifiable intangible assets), liabilities assumed and noncontrolling interest at fair value on the acquisition date. Subsequent changes to the fair value of such assets acquired and liabilities assumed are recognized in earnings, after the expiration of the measurement period, a period not to exceed 12 months from the acquisition date. Acquisition-related expenses and acquisition-related restructuring costs are recognized in earnings in the period in which they are incurred.
Accounting Standard Not Yet Adopted	Accounting Standard Not Yet Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financing Reporting. This guidance provides temporary optional expedients and exceptions through December 31, 2022 to the U.S. GAAP guidance on contract modifications to ease the financial reporting burdens of the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates. The Company expects to adopt this guidance and apply it to reference rate reform effected arrangement modifications. Although there are several other new accounting pronouncements issued by the FASB, the Company does not believe any of these accounting pronouncements had or will have a material impact on its Consolidated Financial Statements.

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 25, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Customers as Percentage of Total Revenues	The Company’s most significant customers (having accounted for 10% or more of revenues) and their related revenues as a percentage of total revenues were as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 Lam Research Corporation 38.3 % 39.6 % 41.6 % 42.0 % Applied Materials, Inc. 24.1 % 25.8 % 23.9 % 24.7 % Total 62.4 % 65.4 % 65.5 % 66.7 %

Business Combinations (Tables)

Business Combinations (Tables) - Ham-Let [Member]	6 Months Ended
	Jun. 25, 2021
Business Acquisition [Line Items]
Summary of Preliminary Fair Values of Assets Acquired, Liabilities Assumed and Noncontrolling Interest at Date of Acquisition	The following table summarizes the preliminary fair values of assets acquired, liabilities assumed and noncontrolling interest at the date of acquisition (in millions): Cash and cash equivalents $ 20.1 Accounts receivable 51.6 Inventories 80.3 Prepaid expenses and other assets 17.3 Property, plant and equipment 52.1 Goodwill 86.1 Purchased intangible assets 124.4 Deferred tax assets 0.8 Operating lease right-of-use assets 27.7 Other non-current assets 2.2 Total assets acquired 462.6 Bank borrowings (5.0 ) Accounts payable (30.8 ) Accrued compensation and related benefits (10.5 ) Other current liabilities (12.4 ) Deferred tax liabilities (12.0 ) Operating lease liabilities (23.8 ) Other liabilities (4.0 ) Total liabilities assumed (98.5 ) Noncontrolling interests (1.2 ) Total consideration transferred $ 362.9
Summary of Purchased Intangible Assets	Purchased Useful Life Intangible Assets (In years) (In millions) Customer relationships 10 $ 73.9 IP Knowhow 10-15 35.5 Trade names 5 9.8 Backlog 1 5.2 Total purchased intangible assets $ 124.4
Unaudited Pro forma Consolidated Results of Operations	The unaudited pro forma consolidated results of operations for the three and six months ended June 25, 2021 and June 26, 2020 (in millions, except per share amounts) as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 (In millions, except per share amounts) Revenues $ 515.2 $ 391.8 $ 989.1 $ 760.9 Net income $ 23.1 $ 13.1 $ 54.1 $ 4.0 Basic income per share $ 0.53 $ 0.33 $ 1.29 $ 0.10 Diluted income per share $ 0.52 $ 0.32 $ 1.26 $ 0.10

Balance Sheet Information (Tabl

Balance Sheet Information (Tables)	6 Months Ended
	Jun. 25, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Inventories	Inventories consisted of the following: June 25, December 25, (In millions) 2021 2020 Raw materials $ 155.7 $ 102.9 Work in process 89.6 64.5 Finished goods 56.7 13.0 Total $ 302.0 $ 180.4
Property, Plant and Equipment, Net	Property, plant and equipment, net, consisted of the following: Useful Life June 25, December 25, (In millions) (in years) 2021 2020 Land $ 4.8 $ 3.8 Buildings 50 39.5 37.2 Machinery and equipment 5-10 115.0 73.8 Leasehold improvements * 53.2 46.7 Computer equipment and software 3-10 48.1 42.5 Furniture and fixtures 5 4.9 4.4 265.5 208.4 Accumulated depreciation (97.0 ) (84.0 ) Construction in progress 49.8 34.8 Total $ 218.3 $ 159.2

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 25, 2021
Fair Value Disclosures [Abstract]
Assets or Liabilities Measured at Fair Value	The following table summarizes, for assets or liabilities measured at fair value, the respective fair value and the classification by level of input within the fair value hierarchy: Fair Value Measurement at Reporting Date Using Description June 25, 2021 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In millions) Prepaid expenses and other: Forward contracts $ 0.1 $ — $ 0.1 $ — Other non-current assets: Purchase option $ 1.1 $ — $ — $ 1.1 Other liabilities: Common stock purchase obligation $ 14.0 $ — $ — $ 14.0 Pension obligation $ 5.5 $ — $ — $ 5.5 Fair Value Measurement at Reporting Date Using Description December 25, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In millions) Prepaid expenses and other: Forward contracts $ 1.1 $ — $ 1.1 $ — Other liabilities: Common stock purchase obligation $ 12.6 $ — $ — $ 12.6 Pension obligation $ 4.7 $ — $ — $ 4.7
Summary of Qualitative Information About Level 3 Fair Value Measurements	There were no transfers from Level 1 or Level 2. Fair value adjustments were noncash, and therefore did not impact the Company’s liquidity or capital resources. Qualitative information about Level 3 fair value measurements is as follows: June 25, Valuation Unobservable 2021 Techniques Input Range/Multiple (Dollars in millions, except rate/multiple) Purchase option $ 1.1 Black‑Scholes option-pricing model Volatility 65.0 % Risk free interest rate 0.03 % Stock price $ 1.2 Strike price $ 0.1 Common stock purchase obligation $ 14.0 Discounted cash flow Revenue multiple 1.3 - 1.5 EBITDA Multiple 4.5 - 7.4 Discount rate 15.0% - 20.0% Pension obligation $ 5.5 Projected unit credit method Discount rate 2.1 % Rate on return 2.5 % Salary increase rate 4.0 %
Summary of Level 3 Activity	Following is a summary of the Level 3 activity: (In millions) Purchase option Common stock purchase obligation Pension obligation As of December 25, 2020 $ — $ 12.6 $ 4.7 Fair value adjustments — 1.4 0.8 Acquisition of Ham-Let 1.1 — — As of June 25, 2021 $ 1.1 $ 14.0 $ 5.5

Financial Instruments (Table)

Financial Instruments (Table)	6 Months Ended
	Jun. 25, 2021
Financial Instruments Disclosures [Abstract]
Schedule of Derivative Instruments at Gross Fair Value	The following tables show the Company’s derivative instruments at gross fair value as of June 25, 2021 and December 25, 2020. June 25, 2021 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total (In millions) Location Hedge Instruments Hedge Instruments Fair Value Derivative liabilities: Level 2: Forward contracts Prepaid expenses and other $ 0.1 $ — $ 0.1 December 25, 2020 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total (In millions) Location Hedge Instruments Hedge Instruments Fair Value Derivative assets Level 2: Forward contracts Prepaid expenses and other $ — $ 1.1 $ 1.1
Schedule of The Effect of Derivative Instruments in Cash Flow Hedging Relationships on Income and Other Comprehensive Income (OCI)	The effect of derivative instruments in cash flow hedging relationships on income and other comprehensive income (OCI) is summarized below: Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion) Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions) 2021 2020 2021 2020 Derivatives in Cash Flow Hedging Relationship Forward contracts $ 0.6 $ — $ (0.1 ) $ —
Schedule of Amount of Gain or Loss Reclassified From Accumulated OCI into Income	The amount of gain or loss reclassified from accumulated OCI into income is not significant for the three and six months ended June 25, 2021 and for the three and six months ended June 26, 2020. Losses Recognized in Income on Derivatives Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions) Income Statement Location 2021 2020 2021 2020 Derivatives Not Designated As Hedging Instruments Forward contracts Other income (expense), net $ - $ — $ (11.6 ) $ —

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 25, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Details of Goodwill	Details of aggregate goodwill of the Company are as follows: (In millions) Products Services Total Balance at December 25, 2020 $ 97.6 $ 73.5 $ 171.1 Acquisition of Ham-Let 86.1 — 86.1 Balance at June 25, 2021 $ 183.7 $ 73.5 $ 257.2
Purchased Intangible Assets	Details of intangible assets were as follows: As of June 25, 2021 As of December 25, 2020 Gross Gross Useful Life Carrying Accumulated Carrying Carrying Accumulated Carrying (Dollars in millions) (in years) Amount Amortization Value Amount Amortization Value Customer relationships 6 - 10 $ 193.3 $ (57.9 ) $ 135.4 $ 119.4 $ (50.6 ) $ 68.8 Tradename 4 - 6* 36.8 (14.1 ) 22.7 27.0 (11.7 ) 15.3 Intellectual property/know-how 7 - 15 49.4 (11.1 ) 38.3 13.9 (9.8 ) 4.1 Recipes 20 73.2 (10.4 ) 62.8 73.2 (8.5 ) 64.7 Standard operating procedures 20 8.6 (1.2 ) 7.4 8.6 (1.0 ) 7.6 Backlog 1 5.2 (1.3 ) 3.9 — — — Total $ 366.5 $ (96.0 ) $ 270.5 $ 242.1 $ (81.6 ) $ 160.5 * The Company concluded that the asset life of the UCT tradename of $9.0 million is indefinite and is therefore not amortized but is reviewed for impairment at least annually and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable.
Future Estimated Amortization Expense	As of June 25, 2021, future estimated amortization expense is expected to be as follows: Amortization (In millions) Expense 2021 (remaining in year) $ 19.0 2022 33.4 2023 26.4 2024 25.5 2025 23.2 Thereafter 134.0 Total $ 261.5

Employee Stock Plans (Tables)

Employee Stock Plans (Tables)	6 Months Ended
	Jun. 25, 2021
Postemployment Benefits [Abstract]
Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations	The following table shows the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions) 2021 2020 2021 2020 Cost of revenues (1) $ 0.4 $ 0.5 $ 0.9 $ 1.0 Research and development - 0.1 0.1 0.1 Sales and marketing 0.4 0.3 0.7 0.6 General and administrative 2.9 2.2 5.5 4.5 3.7 3.1 7.2 6.2 Income tax benefit (0.9 ) (0.6 ) (1.7 ) (1.5 ) Stock-based compensation expense, net of tax $ 2.8 $ 2.5 $ 5.5 $ 4.7
Summary of Restricted Stock Unit, Performance Stock Units and Restricted Stock Award Activity	The following table summarizes the Company’s combined RSU, PSU and RSA activity for the six months ended June 26, 2020: (In millions) Shares Aggregate Fair Unvested RSUs, PSUs and RSAs at December 25, 2020 1.7 $ 54.1 Granted 0.4 Vested (0.6 ) Forfeited (0.1 ) Unvested RSUs, PSUs and RSAs as of June 25, 2021 1.4 $ 76.6 Vested and expected to vest RSUs, PSUs and RSAs as of June 25, 2021 1.3 $ 67.4

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 25, 2021
Revenue From Contract With Customer [Abstract]
Revenue by Geographic Area	The following table sets forth revenue by geographic area (in millions): Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 United States $ 187.3 $ 155.1 $ 359.9 $ 297.7 Singapore 182.5 119.6 335.8 231.8 South Korea 36.7 21.3 63.3 41.6 China 25.4 12.0 41.4 21.1 Taiwan 23.1 15.0 43.3 30.2 Austria 20.6 13.0 39.3 27.5 Israel 5.4 4.2 9.4 7.9 Other 34.2 4.6 40.4 7.9 $ 515.2 $ 344.8 $ 932.8 $ 665.7

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 25, 2021
Leases [Abstract]
Summary of Components of Lease Expense	The components of lease expense were summarized as follows: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (Dollars in millions) 2021 2020 2021 2020 Operating lease cost $ 4.8 $ 3.4 $ 8.5 $ 6.6 Short-term lease cost 0.5 0.3 0.9 0.6 Total lease cost $ 5.3 $ 3.7 $ 9.4 $ 7.2 Operating cash flows from operating leases $ 5.5 $ 4.4 $ 9.2 $ 8.8 Weighted-average remaining lease term – operating leases 1.8 2.2 Weighted-average discount rate – operating leases 5.1 % 5.5 %
Summary of Future Minimum Payments under Operating Leases	Future minimum payments under operating leases as of June 25, 2021 were summarized as follows: (In millions) Operating Leases 2021 remaining $ 9.3 2022 17.4 2023 14.4 2024 11.0 2025 8.1 Thereafter 22.3 Total minimum lease payments 82.5 Less: imputed interest 12.2 Lease liability $ 70.3

Net Income Per Share (Tables)

Net Income Per Share (Tables)	6 Months Ended
	Jun. 25, 2021
Earnings Per Share [Abstract]
Basic and Diluted Net Income Per Share	The following is a reconciliation of the numerators and denominators used in computing basic and diluted net income (loss) per share: Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, (In millions, except share amounts) 2021 2020 2021 2020 Numerator: Net income attributable to UCT $ 17.1 $ 21.3 $ 42.1 $ 30.7 Denominator: Shares used in computation — basic: Weighted average common shares outstanding 43.3 40.1 41.9 39.9 Shares used in computation — diluted: Weighted average common shares outstanding 43.3 40.1 41.9 39.9 Dilutive effect of common shares outstanding subject to repurchase 1.0 0.7 1.0 0.9 Shares used in computing diluted net income per share 44.3 40.8 42.9 40.8 Net income per share attributable to UCT — basic $ 0.39 $ 0.53 $ 1.00 $ 0.77 Net income per share attributable to UCT — diluted $ 0.39 $ 0.52 $ 0.98 $ 0.75

Reportable Segments (Tables)

Reportable Segments (Tables)	6 Months Ended
	Jun. 25, 2021
Segment Reporting [Abstract]
Summary of Segment Description and Data	The following table describes each segment: Segment Product or Services Markets Served Geographic Areas Products Assembly Weldments Machining Fabrication Components Semiconductor Americas Asia Pacific EMEA Services Cleaning Analytics Semiconductor Americas Asia Pacific EMEA Segment Data Three Months Ended Six Months Ended June 25, June 26, June 25, June 26, 2021 2020 2021 2020 Revenues: Products $ 442.5 $ 277.9 $ 788.1 $ 537.3 Services 72.7 66.9 144.7 128.4 Total segment revenues $ 515.2 $ 344.8 $ 932.8 $ 665.7 Gross profit: Products $ 74.6 $ 48.6 $ 136.6 $ 93.3 Services 25.3 25.3 50.2 46.3 Total segment gross profit $ 99.9 $ 73.9 $ 186.8 $ 139.6 Operating profit: Products $ 24.0 $ 24.3 $ 58.2 $ 44.6 Services 7.9 6.5 14.1 8.8 Consolidated income from operations $ 31.9 $ 30.8 $ 72.3 $ 53.4 June 25, December 25, 2021 2020 Assets Products $ 1,597.1 $ 868.4 Services 249.6 234.1 Total segment assets $ 1,846.7 $ 1,102.5

Organization and Significant _4

Organization and Significant Accounting Policies - Additional Information (Detail)	Apr. 13, 2021USD ($)shares	Mar. 31, 2021USD ($)	Jun. 26, 2021USD ($)SegmentCustomer	Jun. 25, 2021Segmentshares	Dec. 25, 2020Customershares
Concentration Risk [Line Items]
Number Of Operating Segments | Segment			2	2
Common stock, shares outstanding | shares				44,700,000	40,600,000
Number of reportable segments | Segment			2
Impairments of goodwill and intangible assets			$ 0
Customer Concentration Risk [Member] | Lam Research Corporation, Applied Materials, Inc. and ASM International, Inc. [Member]
Concentration Risk [Line Items]
Number of customers with accounts receivable greater than 10% | Customer			2		3
Customer Concentration Risk [Member] | Lam Research Corporation, Applied Materials, Inc. and ASM International, Inc. [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration percentage			38.00%		67.30%
Minimum [Member]
Concentration Risk [Line Items]
Fiscal year duration			364 days
Useful lives range			3 years
Minimum [Member] | Internal Use Software [Member]
Concentration Risk [Line Items]
Useful lives range			3 years
Maximum [Member]
Concentration Risk [Line Items]
Fiscal year duration			371 days
Useful lives range			50 years
Measurement period to determine fair value of assets and liabilities			12 months
Maximum [Member] | Internal Use Software [Member]
Concentration Risk [Line Items]
Useful lives range			10 years
Underwritten Public Offering [Member]
Concentration Risk [Line Items]
Common stock, shares outstanding | shares	3,181,818
Net proceeds from public offering	$ 167,600,000
Exercised stock option, transaction date	Apr. 29, 2021
Purchase of common stock | shares	477,272
Purchase of common stock in cash	$ 25,200,000
Ham Let Israel Canada Ltd
Concentration Risk [Line Items]
Number Of Operating Segments | Segment			2
Date of acquisition		Mar. 31, 2021
Total purchase consideration		$ 362,900,000
Equity value		273,500,000
Net debt		91,300,000
Repayment of debt		$ 1,900,000

Organization and Significant _5

Organization and Significant Accounting Policies - Customers as Percentage of Total Revenues (Detail) - Sales [Member] - Customer Concentration Risk [Member]	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Concentration Risk [Line Items]
Total	62.40%	65.40%	65.50%	66.70%
Lam Research Corporation [Member]
Concentration Risk [Line Items]
Total	38.30%	39.60%	41.60%	42.00%
Applied Materials, Inc. [Member]
Concentration Risk [Line Items]
Total	24.10%	25.80%	23.90%	24.70%

Business Combinations - Additio

Business Combinations - Additional Information (Detail) ₪ in Millions, $ in Millions	Mar. 31, 2021USD ($)	Apr. 15, 2019USD ($)	Aug. 31, 2020USD ($)	Jun. 25, 2021USD ($)	Jun. 25, 2021USD ($)	Jun. 26, 2020USD ($)	Jun. 26, 2020USD ($)	Jun. 25, 2021USD ($)	Jun. 25, 2021ILS (₪)	Jun. 26, 2020USD ($)	Jun. 26, 2020USD ($)	Dec. 25, 2020USD ($)
Business Acquisition [Line Items]
Acquisition related costs							$ 14.9				$ 14.9
Other income (expense), net				$ (0.7)		$ 0.6		$ (5)		$ (2.1)
Revenues				515.2	$ 515.2	$ 344.8	344.8	932.8		$ 665.7	665.7
Amortization of intangible assets				9.5			$ 4.9	$ 14.4			$ 9.9
Ham-Let [Member]
Business Acquisition [Line Items]
Date of acquisition								Mar. 31, 2021	Mar. 31, 2021
Total purchase consideration	$ 362.9
Business acquisition equity value	273.5
Net debt	91.3
Repayment of debt	1.9
Acquisition related costs	10.5			8.1				$ 9.5				$ 1
Charged to operations								9.5
Cash borrowed for acquisition and refinancing	$ 355
Expected cash consideration for equity valuation								287.1	₪ 934.7
Payments for forward hedge contracts | ₪									₪ 905.8
Cash payments to acquire business								283.9
Other income (expense), net				10.4				10.4
Revenues				58.2				58.2
Amortization of intangible assets				$ 4.6				$ 4.6
Dynamic Manufacturing Solutions [Member]
Business Acquisition [Line Items]
Date of acquisition		Apr. 15, 2019
Business acquisition potential cash earn-out payments		$ 12.5
Earn-out payments, fair market value			$ 12.5

Business Combinations - Summary

Business Combinations - Summary of Preliminary Fair Values of Assets Acquired, Liabilities Assumed and Noncontrolling Interest at Date of Acquisition (Detail) - USD ($) $ in Millions	Jun. 25, 2021	Mar. 31, 2021	Dec. 25, 2020
Business Combinations [Abstract]
Cash and cash equivalents		$ 20.1
Accounts receivable		51.6
Inventories		80.3
Prepaid expenses and other assets		17.3
Property, plant and equipment		52.1
Goodwill	$ 257.2	86.1	$ 171.1
Purchased intangible assets		124.4
Deferred tax assets		0.8
Operating lease right-of-use assets		27.7
Other non-current assets		2.2
Total assets acquired		462.6
Bank borrowings		(5)
Accounts payable		(30.8)
Accrued compensation and related benefits		(10.5)
Other current liabilities		(12.4)
Deferred tax liabilities		(12)
Operating lease liabilities		(23.8)	$ (23.8)
Other liabilities		(4)
Total liabilities assumed		(98.5)
Noncontrolling interests		(1.2)
Total consideration transferred		$ 362.9

Business Combinations - Schedul

Business Combinations - Schedule of Total Purchased Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 25, 2021	Mar. 31, 2021
Business Acquisition [Line Items]
Purchased intangible assets		$ 124.4
Ham-Let [Member]
Business Acquisition [Line Items]
Purchased intangible assets	$ 124.4
Ham-Let [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Purchased intangible assets	73.9
Ham-Let [Member] | IP Knowhow [Member] | Minimum [Member]
Business Acquisition [Line Items]
Purchased intangible assets	35.5
Ham-Let [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Purchased intangible assets	9.8
Ham-Let [Member] | Backlog [Member]
Business Acquisition [Line Items]
Purchased intangible assets	$ 5.2

Business Combinations - Unaudit

Business Combinations - Unaudited Pro forma Consolidated Results of Operations (Detail) - Ham-Let [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Business Acquisition [Line Items]
Revenues	$ 515.2	$ 391.8	$ 989.1	$ 760.9
Net income	$ 23.1	$ 13.1	$ 54.1	$ 4
Basic income per share	$ 0.53	$ 0.33	$ 1.29	$ 0.10
Diluted income per share	$ 0.52	$ 0.32	$ 1.26	$ 0.10

Balance Sheet Information - Sum

Balance Sheet Information - Summary of Inventories (Detail) - USD ($) $ in Millions	Jun. 25, 2021	Dec. 25, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 155.7	$ 102.9
Work in process	89.6	64.5
Finished goods	56.7	13
Total	$ 302	$ 180.4

Balance Sheet Information - Pro

Balance Sheet Information - Property, Plant and Equipment, Net (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 26, 2021	Jun. 25, 2021	Dec. 25, 2020
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements net excluding construction in progress		$ 265.5	$ 208.4
Accumulated depreciation		(97)	(84)
Construction in progress		49.8	34.8
Total		218.3	159.2
Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	50 years
Land [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		4.8	3.8
Buildings [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		$ 39.5	37.2
Property, plant and equipment, useful life		50 years
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		$ 115	73.8
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		5 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		10 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		$ 53.2	46.7
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		$ 48.1	42.5
Computer Equipment and Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		3 years
Computer Equipment and Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life		10 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross		$ 4.9	$ 4.4
Property, plant and equipment, useful life		5 years

Balance Sheet Information - Add

Balance Sheet Information - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 26, 2020	Jun. 26, 2020	Jun. 26, 2021
Causes Of Increase Decrease In Liability For Unpaid Claims And Claims Adjustment Expense [Line Items]
Restructuring charge	$ 0.9	$ 1.9
Facility Fire [Member] | Other Income Expense [Member]
Causes Of Increase Decrease In Liability For Unpaid Claims And Claims Adjustment Expense [Line Items]
Insurance settlements receivable			$ 7.3

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured (Details) - USD ($) $ in Millions	Jun. 25, 2021	Dec. 25, 2020
Forward Contracts [Member]
Prepaid expenses and other:
Prepaid expense and other assets	$ 0.1	$ 1.1
Purchase Option
Other non-current assets:
Assets measured at fair value	1.1
Common Stock Purchase Obligation [Member]
Other liabilities:
Liabilities measured at fair value	14	12.6
Pension Obligation [Member]
Other liabilities:
Liabilities measured at fair value	5.5	4.7
Significant Other Observable Inputs (Level 2) [Member] | Forward Contracts [Member]
Prepaid expenses and other:
Prepaid expense and other assets	0.1	1.1
Significant Unobservable Inputs (Level 3) [Member] | Purchase Option
Other non-current assets:
Assets measured at fair value	1.1
Significant Unobservable Inputs (Level 3) [Member] | Common Stock Purchase Obligation [Member]
Other liabilities:
Liabilities measured at fair value	14	12.6
Significant Unobservable Inputs (Level 3) [Member] | Pension Obligation [Member]
Other liabilities:
Liabilities measured at fair value	$ 5.5	$ 4.7

Fair Value Measurements- Additi

Fair Value Measurements- Additional Information (Details) - Rovac	Jun. 25, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Ownership Percentage	70.00%
Ownership Percentage By Noncontrolling Owners	30.00%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Qualitative Information About Level 3 Fair Value Measurements (Details) - Fair Value Level 3 [Member]	Jun. 25, 2021USD ($)
EBITDA Multiple [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.055
EBITDA Multiple [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.074
Measurement Input Risk Free Interest Rate [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.03
Discount Rate [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.155
Discount Rate [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.200
Measurement Input Stock Price [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	1.2
Rate on Return [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.025
Measurement Input Strike Price [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.1
Salary Increase Rate [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.040
Purchase Option
Defined Benefit Plan Disclosure [Line Items]
Contingent consideration	$ 1,100,000
Contingent consideration	$ 1,100,000
Purchase Option | Measurement Input Volatility [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	65
Common Stock Purchase Obligation [Member]
Defined Benefit Plan Disclosure [Line Items]
Contingent consideration	$ 14,000,000
Contingent consideration	$ 14,000,000
Business Combination Contingent Consideration Liability Valuation Technique Extensible List	us-gaap:ValuationTechniqueDiscountedCashFlowMember
Common Stock Purchase Obligation [Member] | Revenue Multiple [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.013
Common Stock Purchase Obligation [Member] | Revenue Multiple [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.017
Pension Obligation [Member]
Defined Benefit Plan Disclosure [Line Items]
Contingent consideration	$ 5,500,000
Contingent consideration	$ 5,500,000
Pension Obligation [Member]
Defined Benefit Plan Disclosure [Line Items]
Business Combination Contingent Consideration Liability Valuation Technique Extensible List	uctt:ValuationTechniqueProjectedUnitCreditMethodMember
Pension Obligation [Member] | Discount Rate [Member]
Defined Benefit Plan Disclosure [Line Items]
Range/Multiple	0.021

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of the Level 3 Activity - (Details) $ in Millions	6 Months Ended
	Jun. 25, 2021USD ($)
Pension Obligation [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	$ 4.7
Fair value adjustments	0.8
Ending balance	5.5
Purchase Option
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Acquisition of Ham-Let	1.1
Ending balance	1.1
Common Stock Purchase Obligation [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	12.6
Fair value adjustments	1.4
Ending balance	$ 14

Financial Instrument- Schedule

Financial Instrument- Schedule of Derivative Instruments at Gross Fair Value (Detail) - Forward Contracts [Member] - Prepaid Expensed and other [Member] - Significant Other Observable Inputs (Level 2) [Member] - USD ($) $ in Millions	Jun. 25, 2021	Dec. 25, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Derivative Liabilities	$ 0.1
Fair Value of Derivative Assets		$ 1.1
Fair Value of Derivatives Designated as Hedging Instuments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Derivative Liabilities	$ 0.1
Fair Value of Derivatives Not Designated as Hedging Instuments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Derivative Assets		$ 1.1

Financial Instrument - Schedule

Financial Instrument - Schedule of The Effect of Derivative Instruments in Cash Flow Hedging Relationships on Income and Other Comprehensive Income (OCI) (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021
Forward Contracts [Member] | Derivatives in Cash Flow Hedging Relationship [Member]
Defined Benefit Plan Disclosure [Line Items]
Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion)	$ 0.6	$ (0.1)

Financial Instrument - Schedu_2

Financial Instrument - Schedule of Amount of Gain or Loss Reclassified From Accumulated OCI into Income (Detail) $ in Millions	6 Months Ended
	Jun. 25, 2021USD ($)
Forward Contracts [Member] | Fair Value of Derivatives Not Designated as Hedging Instuments [Member] | Other income (expense) net [Member]
Defined Benefit Plan Disclosure [Line Items]
Losses Recognized in Income on Derivatives	$ (11.6)

Financial Instrument - Addition

Financial Instrument - Additional Information (Detail) $ in Millions	Mar. 26, 2021USD ($)
Foreign Exchange Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Liability related to Forward Hedge contracts	$ 10.4

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Details of Goodwill (Detail) $ in Millions	6 Months Ended
	Jun. 25, 2021USD ($)
Goodwill [Line Items]
Goodwill	$ 171.1
Goodwill	257.2
Ham-Let [Member]
Goodwill [Line Items]
Acquisition of Ham-Let	86.1
SPS [Member]
Goodwill [Line Items]
Goodwill	97.6
Goodwill	183.7
SPS [Member] | Ham-Let [Member]
Goodwill [Line Items]
Acquisition of Ham-Let	86.1
SSB [Member]
Goodwill [Line Items]
Goodwill	73.5
Goodwill	73.5
SSB [Member] | Ham-Let [Member]
Goodwill [Line Items]
Acquisition of Ham-Let	$ 0

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Purchased Intangible Assets (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 25, 2021	Dec. 25, 2020
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, accumulated amortization	$ (96)	$ (81.6)
Definite lives intangible assets, net carrying amount	261.5
Intangible Assets, gross carrying value	366.5	242.1
Intangible Assets, net carrying value	$ 270.5	160.5
Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	7 years
Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	12 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 193.3	119.4
Definite lives intangible assets, accumulated amortization	(57.9)	(50.6)
Definite lives intangible assets, net carrying amount	$ 135.4	68.8
Customer Relationships [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	6 years
Customer Relationships [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	10 years
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 36.8	27
Definite lives intangible assets, accumulated amortization	(14.1)	(11.7)
Definite lives intangible assets, net carrying amount	$ 22.7	15.3
Trade Names [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	4 years
Trade Names [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	6 years
IP Knowhow [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 49.4	13.9
Definite lives intangible assets, accumulated amortization	(11.1)	(9.8)
Definite lives intangible assets, net carrying amount	$ 38.3	4.1
Backlog [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	1 year
Definite lives intangible assets, gross carrying amount	$ 5.2
Definite lives intangible assets, accumulated amortization	(1.3)
Definite lives intangible assets, net carrying amount	3.9
Intangible Assets, gross carrying value	5.2
Intangible Assets, net carrying value	$ 3.9
Recipes [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	20 years
Definite lives intangible assets, gross carrying amount	$ 73.2	73.2
Definite lives intangible assets, accumulated amortization	(10.4)	(8.5)
Definite lives intangible assets, net carrying amount	$ 62.8	64.7
Standard Operating Procedures [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	20 years
Definite lives intangible assets, gross carrying amount	$ 8.6	8.6
Definite lives intangible assets, accumulated amortization	(1.2)	(1)
Definite lives intangible assets, net carrying amount	$ 7.4	$ 7.6

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Purchased Intangible Assets (Parenthetical) (Detail) $ in Millions	6 Months Ended
	Jun. 25, 2021USD ($)
UCT Tradename [Member]
Finite Lived Intangible Assets [Line Items]
Indefinite lived intangible assets acquired	$ 9

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 9.5	$ 4.9	$ 14.4	$ 9.9

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets - Future Estimated Amortization Expense (Detail) $ in Millions	Jun. 25, 2021USD ($)
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
2021 (remaining in year)	$ 19
2022	33.4
2023	26.4
2024	25.5
2025	23.2
Thereafter	134
Definite lives intangible assets, net carrying amount	$ 261.5

Borrowing Arrangements - Additi

Borrowing Arrangements - Additional Information (Detail) € in Millions, ₩ in Billions	Jun. 25, 2021USD ($)	Mar. 31, 2021USD ($)	Aug. 31, 2018USD ($)	Jun. 25, 2021USD ($)	Jun. 25, 2021KRW (₩)	Jun. 25, 2021EUR (€)
Bank Debt [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ 15,300,000			$ 15,300,000
Outstanding amount of borrowing classified as long-term debt	594,700,000			594,700,000
Cincos Xian Clean Technology, Ltd [Member] | China [Member] | Bank Debt [Member]
Debt Instrument [Line Items]
Outstanding debt	$ 2,700,000			$ 2,700,000
Debt instrument interest rate	3.10%			3.10%	3.10%	3.10%
Ham-Let [Member]
Debt Instrument [Line Items]
Cash borrowed for acquisition and refinancing		$ 355,000,000
Outstanding debt	$ 8,400,000			$ 8,400,000
Minimum [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio			1.25%
Minimum [Member] | Ham-Let [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	1.80%			1.80%	1.80%	1.80%
Maximum [Member]
Debt Instrument [Line Items]
Consolidated leverage ratio			3.75%
Maximum [Member] | Ham-Let [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	4.60%			4.60%	4.60%	4.60%
Term Loan Credit Facility [Member] | Barclays Bank PLC [Member]
Debt Instrument [Line Items]
Cash borrowed for acquisition and refinancing		272,800,000	$ 350,000,000
Outstanding term loan	$ 598,900,000	$ 355,000,000		$ 598,900,000
Term loan, maturity date			Aug. 27, 2025
Percentage of original outstanding principal balance as quarterly principal payment			0.625%
Debt instrument, frequency of periodic payment				The Term Loan has a maturity date of August 27, 2025, with monthly interest payments in arrears, quarterly principal payments of 0.625% of the outstanding principal balance thereof as of March 31, 2021, with the remaining principal paid upon maturity
Description of interest rate term				Under the Credit Agreement, the Company may elect that the term loans bear interest at a rate per annum equal to either (a) “ABR” (as defined in the Credit Agreement), plus the applicable margin or (b) the “Eurodollar Rate” (as defined in the Credit Agreement), based on LIBOR, plus the applicable margin. The applicable margin for the term loan under the Credit Agreement is equal to a rate per annum to either (i) at any time that the Company’s corporate family rating is Ba3 (with a stable outlook) or higher from Moody’s and BB- (with a stable outlook) or higher from S&P, (x) 3.50% for such Eurodollar term loans and (y) 2.50% for such ABR term loans or (ii) at all other times, (x) 3.75% for such Eurodollar term loans and (y) 2.75% for such ABR term loans. Interest on the term loans is payable on (1) in the case of such ABR term loans, the last day of each calendar quarter and (2) in the case of such Eurodollar term loans, the last day of each relevant interest period and, in the case of any interest period longer than three months, on each successive date three months after the first day of such interest period. On March 29, 2021, the Company elected that the term loan outstanding as of March 31, 2021 accrue interest based on the “Eurodollar Rate” for an initial interest period of one month. As of March 31, 2021, the applicable margin with respect to the term loan facility was 3.75%. Pursuant to the Second Amendment to the Credit Agreement made effective on March 31, 2021, the Credit Agreement contains customary LIBOR replacement provisions in the event LIBOR is discontinued.
Unamortized debt issuance costs	$ 15,300,000			$ 15,300,000
Term Loan Credit Facility [Member] | Barclays Bank PLC [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate		3.75%		3.84%
Term Loan Credit Facility [Member] | Barclays Bank PLC [Member] | Eurodollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate		3.50%
Term Loan Credit Facility [Member] | Barclays Bank PLC [Member] | Eurodollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate		3.75%
Term Loan Credit Facility [Member] | Barclays Bank PLC [Member] | ABR [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate	2.50%
Term Loan Credit Facility [Member] | Barclays Bank PLC [Member] | ABR [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate	2.75%
Revolving Credit Facility [Member] | China [Member]
Debt Instrument [Line Items]
Outstanding amount under credit facility	$ 0			$ 0
Revolving Credit Facility [Member] | China [Member] | Bank Debt [Member]
Debt Instrument [Line Items]
Remaining available commitments	800,000			800,000
Revolving Credit Facility [Member] | Czech Republic [Member] | Bank Debt [Member]
Debt Instrument [Line Items]
Initial available commitment | €						€ 6
Revolving Credit Facility [Member] | United States [Member] | Bank Debt [Member]
Debt Instrument [Line Items]
Remaining available commitments	65,000,000			65,000,000
Revolving Credit Facility [Member] | Czech Republic [Member] | Bank Debt [Member]
Debt Instrument [Line Items]
Remaining available commitments	9,800,000			9,800,000
Revolving Credit Facility [Member] | Cinos Co., Ltd [Member] | Korea [Member]
Debt Instrument [Line Items]
Initial available commitment	500,000			500,000	₩ 0.6
Revolving Credit Facility [Member] | Cincos Xian Clean Technology, Ltd [Member] | China [Member]
Debt Instrument [Line Items]
Initial available commitment	3,500,000			$ 3,500,000
Maturity date				Sep. 23, 2022
Revolving Credit Facility [Member] | Minimum [Member] | Cinos Co., Ltd [Member] | Korea [Member]
Debt Instrument [Line Items]
Interest rate				2.90%
Revolving Credit Facility [Member] | Minimum [Member] | Cincos Xian Clean Technology, Ltd [Member] | China [Member]
Debt Instrument [Line Items]
Interest rate				2.00%
Revolving Credit Facility [Member] | Maximum [Member] | Cincos Xian Clean Technology, Ltd [Member] | China [Member]
Debt Instrument [Line Items]
Interest rate				4.10%
Revolving Credit Facility [Member] | Barclays Bank PLC [Member]
Debt Instrument [Line Items]
Initial available commitment			$ 65,000,000
Maturity date			Aug. 27, 2023
Commitment fee percentage			0.25%
Remaining available commitments	65,000,000			$ 65,000,000
Letter of Credit Facility [Member] | Barclays Bank PLC [Member]
Debt Instrument [Line Items]
Initial available commitment			$ 50,000,000
Maturity date			Aug. 27, 2023
Commitment fee percentage			2.50%
Percentage of undrawn and unexpired amount of letter of credit as fronting fee			0.125%
Outstanding amount under credit facility	2,400,000			2,400,000
Remaining available commitments	$ 47,600,000			$ 47,600,000

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020
Income Taxes [Line Items]
Income tax provision	$ 6,200,000	$ 6,200,000	$ 5,700,000	$ 5,700,000	$ 13,200,000	$ 10,200,000	$ 10,200,000
Effective tax rate		25.60%		20.50%	23.20%	23.80%
Undistributed earnings of foreign subsidiaries	317,300,000	$ 317,300,000			$ 317,300,000
Gross liability for unrecognized tax benefits, excluding interest	1,300,000	1,300,000	1,000,000	$ 1,000,000	1,300,000	$ 1,000,000	1,000,000
Provision for income taxes	$ 6,200,000	6,200,000	$ 5,700,000	$ 5,700,000	13,200,000	$ 10,200,000	$ 10,200,000
CARES ACT [Member]
Income Taxes [Line Items]
Income tax provision		0			$ 0
Percentage removal of taxable income limitation on net operating losses deduction					80.00%
Taxable years for carryback of NOLs					2005
Caps for limitation on the deduction for interest expense					50.00%
Percentage of corporate charitable deduction limit of taxable income					25.00%
Eligible for cost recovery years					15 years
Percentage of bonus depreciation					100.00%
Provision for income taxes		$ 0			$ 0

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Compensation And Retirement Disclosure [Abstract]
Benefit obligations	$ 9,600,000		$ 9,600,000
Fair value of benefit plan assets	5,900,000		5,900,000
Unfunded balance of benefit plan	3,700,000		3,700,000
Amounts recognized in accumulated other comprehensive income	500,000		500,000
Contributions to the plan by the Company and its subsidiaries			26,000
Benefits expected to be paid from pension plan in 2021	0		0
Benefits expected to be paid from pension plan in 2022	900,000		900,000
Benefits expected to be paid from pension plan in 2023	2,300,000		2,300,000
Benefits expected to be paid from pension plan in 2024	1,000,000		1,000,000
Benefits expected to be paid from pension plan in 2025	900,000		900,000
Aggregate benefits expected to be paid in five years from 2026-2031	5,700,000		$ 5,700,000
Contribution from salary			25.00%
Matching contribution of participation salary			50.00%
Matching contribution based upon eligibility			6.00%
Discretionary employer contributions	$ 600,000	$ 700,000	$ 1,200,000	$ 1,300,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Jun. 25, 2021USD ($)
Inventories [Member]
Long Term Purchase Commitment [Line Items]
Purchase commitments	$ 405.1

Stockholders' Equity and Nonc_2

Stockholders' Equity and Noncontrolling Interests - Additional Information (Detail) $ in Millions	Jul. 24, 2021	Apr. 13, 2021USD ($)shares	Jun. 25, 2021USD ($)shares	Jun. 26, 2020USD ($)	Apr. 29, 2021shares	Dec. 25, 2020USD ($)shares	Aug. 27, 2018
Business Acquisition [Line Items]
Proceeds from issuance of common stock			$ 193.1	$ 0.3
Common stock, shares authorized | shares			90,000,000		477,272	90,000,000
Sale of stock, consideration received on transaction		$ 25.2
Common Stock Purchase Obligation [Member]
Business Acquisition [Line Items]
Liabilities measured at fair value			$ 14			$ 12.6
Cinos Korea and Cinos China [Member]
Business Acquisition [Line Items]
Percentage of value used for fair value of non-controlling interest estimates							100.00%
Percentage of increase in noncontrolling interest	0.350
Underwritten Public Offering [Member]
Business Acquisition [Line Items]
Issuance of common stock in public offering, Shares | shares		3,181,818
Proceeds from issuance of common stock		$ 167.6

Employee Stock Plans - Addition

Employee Stock Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021	Jun. 26, 2020
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted stock units	300,000		400,000
Weighted average fair value, granted	$ 49.86		$ 49.02
Stock-based compensation cost, net of estimated forfeitures, recognized		$ 26
Outstanding restricted stock	1,400,000	1,400,000
Aggregate fair value	$ 75.6	$ 75.6
Weighted average remaining contractual term (in years)		1 year 3 months 18 days
Vested shares withheld to satisfy withholding tax obligations			100,000
Vested shares issued net of tax withholdings			500,000
Restricted Stock Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period, years		1 year 8 months 12 days
Restricted Stock Units [Member] | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period, years		3 years
Unit purchase price of Restricted Stock Units		$ 0
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period, years		1 year 8 months 12 days
Stock-based compensation cost, net of estimated forfeitures, recognized		$ 26
Outstanding restricted stock	1,400,000	1,400,000
Aggregate fair value	$ 75.6	$ 75.6
Weighted average remaining contractual term (in years)		1 year 3 months 18 days
Restricted Stock Awards [Member] | Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding restricted stock	18,893	18,893
Unamortized expense of company's unvested restricted stock awards	$ 0.8	$ 0.8

Employee Stock Plans - Stock-Ba

Employee Stock Plans - Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 3.7	$ 3.1	$ 7.2	$ 6.2	$ 6.2
Income tax benefit		(0.9)	(0.6)	(1.7)		(1.5)
Stock-based compensation expense, net of tax		2.8	2.5	5.5		4.7
Cost of Revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	[1]	0.4	0.5	0.9		1
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation			0.1	0.1		0.1
Sales and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		0.4	0.3	0.7		0.6
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 2.9	$ 2.2	$ 5.5		$ 4.5
[1]	Stock-based compensation expense capitalized in inventory for the three and six months ended June 25, 2021 and June 26, 2020was not significant.

Employee Stock Plans - Summary

Employee Stock Plans - Summary of Restricted Stock Unit, Performance Stock Units and Restricted Stock Award Activity (Detail) - Restricted Stock Unit, Performance Stock Units and Restricted Stock Award [Member] $ in Millions	6 Months Ended
	Jun. 25, 2021USD ($)shares	Dec. 25, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested RSUs, PSUs and RSAs, Number of Shares, Beginning balance	1,700,000
Granted, Number of Shares	400,000
Vested, Number of Shares	(600,000)
Forfeited, Number of Shares	(100,000)
Unvested RSUs, PSUs and RSAs, Number of Shares, Ending balance	1,400,000
Vested and expected to vest RSUs, PSUs and RSAs,Numbers of Shares	1,300,000
Unvested RSUs, PSUs and RSAs, Aggregate Intrinsic Value | $	$ 76.6	$ 54.1
Vested and expected to vest RSUs, PSUs and RSAs, Aggregate Intrinsic Value | $	$ 67.4

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 25, 2021	Dec. 25, 2020
Accounts Receivable [Member]
Concentration Risk [Line Items]
Unpaid customer rebates	$ 5.7	$ 5.7
Maximum [Member]
Concentration Risk [Line Items]
Product warranty period (in years)	2 years

Revenue Recognition - Summary o

Revenue Recognition - Summary of Revenue by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	$ 515.2	$ 515.2	$ 344.8	$ 344.8	$ 932.8	$ 665.7	$ 665.7
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	187.3		155.1		359.9		297.7
Singapore [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	182.5		119.6		335.8		231.8
South Korea [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	36.7		21.3		63.3		41.6
Taiwan [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	23.1		15		43.3		30.2
Austria [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	20.6		13		39.3		27.5
China [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	25.4		12		41.4		21.1
Other [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	34.2		4.6		40.4		7.9
Israel [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	$ 5.4		$ 4.2		$ 9.4		$ 7.9

Leases - Summary of Components

Leases - Summary of Components of Lease Expense (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Leases [Abstract]
Operating lease cost	$ 4.8	$ 3.4	$ 8.5	$ 6.6
Short-term lease cost	0.5	0.3	0.9	0.6
Total lease cost	5.3	3.7	9.4	7.2
Operating cash flows from operating leases	$ 5.5	$ 4.4	$ 9.2	$ 8.8
Weighted-average remaining lease term – operating leases	1 year 9 months 18 days	2 years 9 months 18 days	1 year 9 months 18 days	2 years 9 months 18 days
Weighted-average discount rate – operating leases	5.10%	5.50%	5.10%	5.50%

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Payments under Operating Leases (Detail) $ in Millions	Jun. 25, 2021USD ($)
Leases [Abstract]
Operating Leases, 2021 (remaining in year)	$ 9.3
Operating Leases, 2022	17.4
Operating Leases, 2023	14.4
Operating Leases, 2024	11
Operating Leases, 2025	8.1
Operating Leases, Thereafter	22.3
Operating Leases, Total minimum lease payments	82.5
Operating Leases, Less: imputed interest	12.2
Operating Leases, Lease liability	$ 70.3

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 25, 2020	Jun. 25, 2021	Mar. 31, 2021
Lessee Lease Description [Line Items]
Assumed facility Leases of acquisition	$ 23.8		$ 23.8
Total minimum lease payments		$ 82.5
Two New Lease Arrangement [Member]
Lessee Lease Description [Line Items]
Lease commencement year	2021
Total minimum lease payments	$ 22.1

Net Income Per Share - Basic an

Net Income Per Share - Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Numerator:
Net income attributable to UCT	$ 17.1	$ 21.3	$ 42.1	$ 30.7
Shares used in computation — basic:
Weighted average common shares outstanding	43.3	40.1	41.9	39.9
Shares used in computation — diluted:
Weighted average common shares outstanding	43.3	40.1	41.9	39.9
Dilutive effect of common shares outstanding subject to repurchase	1	0.7	1	0.9
Shares used in computing diluted net income per share	44.3	40.8	42.9	40.8
Net income per share attributable to UCT — basic	$ 0.39	$ 0.53	$ 1	$ 0.77
Net income per share attributable to UCT — diluted	$ 0.39	$ 0.52	$ 0.98	$ 0.75

Reportable Segments - Additiona

Reportable Segments - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 26, 2021Segment	Jun. 25, 2021USD ($)Segment	Dec. 25, 2020USD ($)
Segment Reporting Information [Line Items]
Number Of Operating Segments | Segment	2	2
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net long-lived assets		$ 111.6
EMEA [Member]
Segment Reporting Information [Line Items]
Net long-lived assets		$ 46.7
Asia [Member]
Segment Reporting Information [Line Items]
Net long-lived assets			$ 90.4
Europe [Member]
Segment Reporting Information [Line Items]
Net long-lived assets			$ 9.4

Reportable Segments - Summary o

Reportable Segments - Summary of Segment Description (Detail)	6 Months Ended
	Jun. 25, 2021
Product [Member]
Segment Reporting Information [Line Items]
Product or Services	Assembly Weldments Machining Fabrication Components
Markets Served	Semiconductor
Geographic Areas	Americas Asia Pacific EMEA
Services [Member]
Segment Reporting Information [Line Items]
Product or Services	Cleaning Analytics
Markets Served	Semiconductor
Geographic Areas	Americas Asia Pacific EMEA

Reportable Segments - Summary_2

Reportable Segments - Summary of Segment Data (Detail) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 25, 2021	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Jun. 26, 2020	Dec. 25, 2020
Revenues:
Revenues	$ 515.2	$ 515.2	$ 344.8	$ 344.8	$ 932.8	$ 665.7	$ 665.7
Gross profit:
Total segment gross profit	99.9	99.9	73.9	73.9	186.8	139.6	139.6
Operating profit:
Consolidated income from operations	31.9	31.9	30.8	30.8	72.3	53.4	53.4
ASSETS
Total segment assets	1,846.7	1,846.7	1,102.5	1,102.5	1,846.7	1,102.5	1,102.5	$ 1,102.5
Product [Member]
Revenues:
Revenues		442.5		277.9	788.1	537.3
Gross profit:
Total segment gross profit		74.6		48.6	136.6	93.3
Operating profit:
Consolidated income from operations		24		24.3	58.2	44.6
ASSETS
Total segment assets	1,597.1	1,597.1	868.4	868.4	1,597.1	868.4	868.4
Services [Member]
Revenues:
Revenues		72.7		66.9	144.7	128.4
Gross profit:
Total segment gross profit		25.3		25.3	50.2	46.3
Operating profit:
Consolidated income from operations		7.9		6.5	14.1	8.8
ASSETS
Total segment assets	$ 249.6	$ 249.6	$ 234.1	$ 234.1	$ 249.6	$ 234.1	$ 234.1