Ultra Clean (UCTT) 10-Q 9 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 30, 2018	Apr. 27, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	UCTT
Entity Registrant Name	Ultra Clean Holdings, Inc.
Entity Central Index Key	1,275,014
Current Fiscal Year End Date	--12-28
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		38,724,272

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Current assets:
Cash and cash equivalents	$ 162,365	$ 68,306
Accounts receivable, net of allowance of $103 and $69, respectively	83,660	90,213
Inventories	261,798	236,840
Prepaid expenses and other	13,225	12,089
Total current assets	521,048	407,448
Equipment and leasehold improvements, net	36,839	32,246
Goodwill	85,248	85,248
Purchased intangibles, net	30,489	31,587
Deferred tax assets, net	5,032	4,951
Other non-current assets	2,181	1,932
Total assets	680,837	563,412
Current liabilities:
Bank borrowings	54,779	12,381
Accounts payable	169,592	173,521
Accrued compensation and related benefits	11,004	10,788
Deferred rent, current portion	676	670
Other current liabilities	9,441	9,987
Total current liabilities	245,492	207,347
Bank borrowings, net of current portion		39,893
Deferred tax liability	10,017	9,981
Deferred rent and other liabilities	5,792	5,886
Total liabilities	261,301	263,107
Commitments and contingencies (See Note 9)
Stockholders’ equity:
Preferred stock — $0.001 par value, 10,000,000 authorized; none outstanding
Common stock — $0.001 par value, 90,000,000 authorized; 38,721,506 and 33,664,940 shares issued and outstanding, in 2018 and 2017, respectively	39	34
Additional paid-in capital	283,665	188,639
Common shares held in treasury, at cost, 601,944 shares in 2018 and 2017	(3,337)	(3,337)
Retained earnings	137,863	113,122
Accumulated other comprehensive gain	1,306	1,847
Total stockholders’ equity	419,536	300,305
Total liabilities and stockholders’ equity	$ 680,837	$ 563,412

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Statement Of Financial Position [Abstract]
Account receivable, allowance	$ 103	$ 69
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	38,721,506	33,664,940
Common stock, shares outstanding	38,721,506	33,664,940
Treasury stock, shares	601,944	601,944

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Income Statement [Abstract]
Sales	$ 314,842	$ 204,594
Cost of goods sold	266,038	167,099
Gross profit	48,804	37,495
Operating expenses:
Research and development	3,029	2,906
Sales and marketing	3,805	3,051
General and administrative	15,062	11,765
Total operating expenses	21,896	17,722
Income from operations	26,908	19,773
Interest and other income (expense), net	326	(938)
Income before provision for income taxes	27,234	18,835
Income tax provision	2,493	4,494
Net income	$ 24,741	$ 14,341
Net income per share:
Basic	$ 0.67	$ 0.43
Diluted	$ 0.66	$ 0.42
Shares used in computing net income per share:
Basic	36,723	33,061
Diluted	37,491	33,865

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 24,741	$ 14,341
Other comprehensive income:
Change in cumulative translation adjustment	336	98
Cash flow hedges:
Change in fair value of derivatives	9	13
Adjustment for net gain (loss) realized and included in net income	(886)	7
Total change in unrealized gain (loss) on derivative instruments	(877)	20
Other comprehensive income (loss), net of tax	(541)	118
Comprehensive income	$ 24,200	$ 14,459

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 24,741	$ 14,341
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,316	1,214
Amortization of finite-lived intangibles	1,098	1,231
Amortization of debt issuance costs	38	38
Stock-based compensation	2,563	1,382
Change in the fair value of financial instruments	(856)	310
Loss on the disposal of fixed assets	52
Changes in assets and liabilities:
Accounts receivable	6,839	(20,078)
Inventories	(24,660)	(19,068)
Prepaid expenses and other	(1,089)	246
Deferred income taxes	(46)	(58)
Other non-current assets	(255)	(245)
Accounts payable	(4,214)	23,793
Accrued compensation and related benefits	187	2,908
Income taxes payable	(2,358)	2,149
Other liabilities	1,723	981
Net cash provided by operating activities	5,079	9,144
Cash flows from investing activities:
Purchases of equipment and leasehold improvements	(5,911)	(2,784)
Net cash used for investing activities	(5,911)	(2,784)
Cash flows from financing activities:
Proceeds from bank borrowings	10,222	1,000
Proceeds from issuance of common stock	94,330	1,383
Principal payments on bank borrowings	(7,873)	(4,697)
Employees’ taxes paid upon vesting of restricted stock units	(1,862)	(1,582)
Net cash provided by (used for) financing activities	94,817	(3,896)
Effect of exchange rate changes on cash and cash equivalents	74	6
Net increase in cash and cash equivalents	94,059	2,470
Cash and cash equivalents at beginning of period	68,306	52,465
Cash and cash equivalents at end of period	162,365	54,935
Supplemental cash flow information:
Income taxes paid	4,761	2,418
Income tax refunds	5	25
Interest paid	435	551
Non-cash investing and financing activities:
Restricted stock issued	7,751	7,003
Equipment and leasehold improvements purchased included in accounts payable	$ 2,686	$ 658

Organization and Significant Ac

Organization and Significant Accounting Policies	3 Months Ended
	Mar. 30, 2018
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”) was founded in November 2002 for the purpose of acquiring Ultra Clean Technology Systems and Service, Inc. Ultra Clean Technology Systems and Service, Inc. was founded in 1991 by Mitsubishi Corporation and was operated as a subsidiary of Mitsubishi until November 2002, when it was acquired by UCT. UCT became a publicly traded company in March 2004. Ultra Clean Technology (Shanghai) Co., Ltd (“UCTS”) and Ultra Clean Micro-Electronics Equipment (Shanghai) Co., Ltd. (“UCME”) were established in 2005 and 2007, respectively, to facilitate the Company’s operations in China. In December 2015, UCTS merged into UCME. Ultra Clean Asia Pacific, Pte, Ltd. (Singapore) was established in fiscal year 2008 to facilitate the Company’s operations in Singapore. In July 2012, UCT acquired American Integration Technologies LLC (“AIT”) to add to the Company’s existing customer base in the semiconductor and medical spaces and to provide additional manufacturing capabilities. In February 2015, UCT acquired Marchi Thermal Systems, Inc. (“Marchi”), a designer and manufacturer of specialty heaters, thermocouples and temperature controllers. Marchi delivers flexible heating elements and thermal solutions to our customers. The Company believes heaters are increasingly critical in equipment design for the most advanced semiconductor nodes. In July 2015, UCT acquired MICONEX s.r.o. (“Miconex”), a privately-held provider of advanced precision fabrication of plastics, to expand the Company’s capabilities with existing customers. 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 wholly-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 29, 2017 balance sheet data were derived from its audited financial statements as of that date. Principles of Consolidation — The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries and all intercompany accounts and transactions have been eliminated in consolidation. 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. Foreign Currency Translation and Remeasurement — The Company has one foreign subsidiary whose functional currency is not its local currency or the U.S. dollar. The Company remeasures the monetary assets and liabilities of this subsidiary into its functional currency. Gains and losses from these remeasurements are recorded in interest and other income (expense), net. The Company then translates the assets and liabilities of this subsidiary into the U.S. dollar. Gains and losses from these translations are recognized in foreign currency translation included in accumulated other comprehensive income (AOCI) within 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 interest and other income (expense), net. Use of Accounting Estimates — The presentation of financial statements in conformity with accounting principles generally accepted in the United States of America 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 reserves on inventory, valuation of deferred tax assets and impairment of goodwill and other 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 adjustment. Actual amounts may differ from those estimates. 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 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. Fair Value of Measurements — The Company measures its cash equivalents, interest rate swap contract and forward contracts 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. 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 (in thousands): Fair Value Measurement at Reporting Date Using Description March 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets: Interest rate swap $ 24 $ — $ 24 $ — Forward contracts $ 1,281 $ — $ 1,281 $ — Fair Value Measurement at Reporting Date Using Description December 29, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets: Interest rate swap $ 30 $ — $ 30 $ — Forward contracts $ 1,302 $ — $ 1,302 $ — Derivative Financial Instruments — 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 interest and 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 standard 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 as to 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. Equipment and Leasehold Improvements, net — Equipment and leasehold improvements are stated at cost, or, in the case of equipment under capital leases, the present value of future minimum lease payments at inception of the related lease. 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 fifteen years. Internal use software — Direct costs incurred to develop software for internal use are capitalized and amortized over an estimated useful life of three to five years. Costs related to the design or maintenance of internal use software are expensed as incurred. Capitalized internal use software is included in computer equipment and software. Construction in progress — Construction in progress is related to the construction or development of property and equipment that has not yet been placed in service for their intended use and is, therefore, not depreciated. Construction in progress currently includes capitalized costs related to the Company’s Enterprise Resource Planning (“ERP”) implementation project. 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 state, federal, 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. The Company continued to maintain a full valuation allowance on its federal, state, and one of its Singapore subsidiary’s deferred tax amounts as of March 30, 2018. Income tax positions must meet a more likely than not recognition threshold to be recognized. Income tax positions that previously failed to meet the more likely than not threshold are recognized in the first subsequent financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more likely than not threshold are derecognized in the first subsequent financial reporting period in which that threshold is no longer met. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits within the Condensed Consolidated Statements of Operations as income tax expense. The calculation of tax liabilities involves significant judgment in estimating the impact of uncertainties in the application of complex tax laws. Resolution of these uncertainties in a manner inconsistent with the Company’s expectations could have a material impact on its results of operations and financial position. Management believes that it has adequately provided for any adjustments that may result from these examinations; however, the outcome of tax audits cannot be predicted with certainty. The determination of the Company’s tax provision is subject to judgments and estimates. Revenue Recognition — See Note 3 to the Company’s Condensed Consolidated Financial Statements. Research and Development Costs — Research and development costs are expensed as 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 stock options and restricted stock using the treasury stock method, except when such shares are anti-dilutive. See Note 7 to the Company’s Condensed Consolidated Financial Statements. 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 considered to be the Chief Executive Officer. The Company operates in one operating segment, and therefore, has one reportable segment. Business Combinations — The Company recognizes assets acquired (including goodwill and identifiable intangible assets) and liabilities assumed 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. Stock-Based Compensation Expense The Company maintains stock-based compensation plans which allow for the issuance of equity-based awards to executives, directors and certain employees. These equity-based awards include stock options, restricted stock awards (“RSAs”) and restricted stock units (“RSUs”) which can be either time-based or performance-based. The Company has not granted stock options to its employees since fiscal year 2010. The Company also maintains an employee stock purchase plan that provides for the issuance of shares to all eligible employees of the Company at a discounted price. Stock-based compensation expense includes compensation costs related to estimated fair values of stock options and 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, typically three years for RSUs and one year for RSAs, and is adjusted for subsequent changes in estimated forfeitures related to all equity-based awards and performance as it relates to performance-based RSUs. The Company applies the fair value recognition provisions based on the FASB’s guidance regarding stock-based compensation. Employee Stock Purchase Plan 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. Under the ESPP, substantially all employees may purchase the Company’s common stock through payroll deductions at a price equal to 95 percent of the fair market value of the Company’s stock at the end of each applicable purchase period. Restricted Stock Units and Restricted Stock Awards The Company grants RSUs to employees and RSAs to non-employee directors as part of the Company’s long term equity compensation plan. Restricted Stock Units — RSUs are granted to employees with a per share or unit purchase price of zero dollars and either have time based or performance based vesting. RSUs typically vest over three years, subject to the employee’s continued service with the Company. 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. The expected cost of the grant is reflected over the service period, and is reduced for estimated forfeitures. During the quarter ended March 30, 2018 the Company granted 174,900 RSUs, with a weighted average fair value of $19.57 per share, and granted 87,050 performance stock units with a weighted average fair value of $19.25 per share Restricted Stock Awards — As of March 30, 2018, a total of 45,000 RSAs were outstanding. The total unamortized expense of the Company’s unvested restricted stock awards as of March 30, 2018 was $0.1 million. The following table summarizes the Company’s RSU, PSU and RSA activity for the three months ended March 30, 2018: Shares Aggregate Fair (in thousands) Unvested restricted stock units and restricted stock awards at December 29, 2017 1,676,312 $ 38,706 Granted 261,950 Vested (387,071 ) Forfeited (16,941 ) Unvested restricted stock units and restricted stock awards at March 30, 2018 1,534,250 $ 29,534 Vested and expected to vest restricted stock units and restricted stock awards at March 30, 2018 1,297,887 $ 24,984 The following table shows the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations (in thousands): Three Months Ended March 30, March 31, 2018 2017 Cost of sales (1) $ 506 $ 343 Research and development 61 53 Sales and marketing 202 124 General and administrative 1,794 862 2,563 1,382 Income tax benefit (236 ) (330 ) Stock-based compensation expense, net of tax $ 2,327 $ 1,052 (1) Stock-based compensation expenses capitalized in inventory for the three months ended March 30, 2018 and March 31, 2017 was not significant. Recently Adopted Accounting Pronouncements Effective December 30, 2017, the Company adopted FASB Accounting Standards Codification (ASC) Revenue from Contracts with Customers (Topic 606) Our implementation team consisted of senior leadership from finance, legal, sales and operations with periodic progress reporting to management and to the audit committee of our board of directors. Implementation consisted of a review of the Company’s significant contracts and an evaluation of our systems and control environment to support additional disclosures under the new standard, as well as updates to our policies and procedures. During our assessment, we considered whether the adoption would require a transition from point-in-time revenue recognition to an over-time approach for products produced by us without an alternative use, which would result in acceleration of revenue. We concluded based on enforceable rights or prevailing terms and conditions included in the agreements with our customers, an enforceable right of payment that includes a reasonable profit throughout the duration of the contract does not exist. Therefore, we will remain at a point-in-time approach and record revenue at the point control transfers to our customers. Beginning fiscal 2018, the Company adopted ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, Beginning fiscal 2018, the Company adopted ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business Beginning fiscal 2018, the Company adopted ASU No. 2017-09, Stock Compensation: Scope of Modification Accounting n. The new guidance requires the application of modification accounting if the value, vesting conditions or classification of the award changes. Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842) . Topic 842 supersedes the lease recognition requirements in ASC Topic 840, Leases. The guidance specifies that an entity who is a lessee under lease agreements should recognize lease assets and lease liabilities for those leases classified as operating leases under previous FASB guidance. The guidance is effective beginning in the first quarter of 2019. Early adoption is permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company is evaluating the impact of adopting this guidance on the Company’s consolidated financial statements. The Company currently expects that its operating lease commitment will be subject to the new standard and recognized as right-of-use asset and operating lease liability upon adoption of this standard, which will increase the total assets and total liabilities that it reports relative to such amounts prior to adoption. In January 2017, the FASB issued Accounting Standards Update No. 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 30, 2018
Investments All Other Investments [Abstract]
Financial Instruments	2. Financial Instruments Derivative Financial Instruments The Company utilizes foreign currency forward contracts with a local financial institution in the Czech Republic to reduce the risk that its cash flows and earnings of its Miconex subsidiary will be adversely affected by foreign currency exchange rate fluctuations and Cash Flow Hedges In September 2015, the Company entered into an interest rate swap with East West Bank and City National Bank with a notional amount of $20.0 million pursuant to which the Company pays the counterparty a fixed rate of 0.99% and receives interest at a variable rate equal to the London Interbank Offered Rate (LIBOR) rate the Company is required to pay under its term loan, or 1.65%, as of March 30, 2018. This interest rate swap effectively locks in a fixed interest rate of 2.99% on $6.2 million of the $7.4 million term loan as of March 30, 2018, with a decreasing notional amount based on prorated quarterly principal payments over the remaining period of the term loan. Gains or losses on the effective portion of a cash flow hedge are reflected as a component of AOCI and subsequently recorded to interest and other income (expense) when the hedged transactions are realized. If the hedged transactions become probable of not occurring, the corresponding amounts in AOCI would be immediately reclassified to interest and other income (expense), net. As of March 30, 2018, the effective portion of the Company’s cash flow hedge before tax effect was less than $0.1 million, of which less than $0.1 million is expected to be reclassified from AOCI into earnings within the next 12 months. Non-Designated Derivatives A portion of Miconex’s forward contracts with a total notional amount of $5.8 million is not designated as a hedging instrument. The Company recognizes gains and losses on these contracts, as well any related costs, in interest and 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 (in thousands) as of March 30, 2018 and December 29, 2017. March 30, 2018 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total Location Hedge Instruments Hedge Instruments Fair Value Derivative assets and liabilities: Level 2: Interest rate swap Prepaid expenses and other $ 24 $ — $ 24 Forward contracts Prepaid expenses and other $ 150 $ 591 $ 741 Forward contracts Other non-current assets $ 118 $ 422 $ 540 December 29, 2017 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total Location Hedge Instruments Hedge Instruments Fair Value Derivative assets and liabilities: Level 2: Interest rate swap Prepaid expenses and other $ 30 $ — $ 30 Forward contracts Prepaid expenses and other $ 714 $ — $ 714 Forward contracts Other non-current assets $ 588 $ — $ 588 The effect of derivative instruments in cash flow hedging relationships on income and other comprehensive income (OCI) is summarized below (in thousands): Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion) Three Months Ended March 30, March 31, 2018 2017 Derivatives in Cash Flow Hedging Relationship Interest rate swap $ (15 ) $ 13 Forward contracts $ 24 $ — Gains Reclassified from AOCI into Income (Effective Portion) Three Months Ended March 30, March 31, Income Statement Location 2018 2017 Derivatives in Cash Flow Hedging Relationship Interest rate swap Interest and other income (expense), net $ 10 $ 7 Forward contracts Cost of goods sold $ 42 $ — There were no gains (losses) recognized in income on derivatives that are excluded from the effectiveness testing and ineffective portion of the cash flow hedge for the three months ended March 30, 2018 and March 31, 2017. The effect of derivative instruments not designated as hedging instruments on income for the three months ended March 30, 2018 was $1.0 million and not significant for the three months ended March 31, 2017.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 30, 2018
Revenue From Contract With Customer [Abstract]
Revenue Recognition	3. Revenue Recognition On December 30, 2017, the Company adopted Topic 606 using the modified retrospective method to those contracts which were not completed as of December 30, 2017. The adoption of Topic 606 did not have a material effect on the Company’s financial position or results of operations. 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 assesses collectability based on the credit worthiness of the customer and past transaction history. The Company performs on-going credit evaluations of customers and generally does not require collateral from customers. The Company operates in one operating and reportable segment as the nature of the Company’s products and production processes, as well as type of customers and distribution methods, is consistent among all of the Company’s products. The Company sells its products 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 most significant customers (having accounted for 10% or more of sales) and their related sales as a percentage of total sales were as follows: Three Months Ended March 30, March 31, 2018 2017 Lam Research Corporation 66.2 % 58.7 % Applied Materials, Inc. 21.4 26.9 Total 87.6 % 85.6 % Two customers’ accounts receivable balances, Lam Research Corporation and Applied Materials, Inc., were individually greater than 10% of accounts receivable as of March 30, 2018 and as of December 29, 2017, and in the aggregate represented approximately 69.5% and 75.8% of accounts receivable, respectively. The Company 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 sales may be required in future periods. The warranty reserve is included in other current liabilities on the Condensed Consolidated Balance Sheets and are not considered significant. The Company’s products are manufactured at our facilities in the U.S.A., China, Singapore and the Czech Republic. See Note 10 for geographical revenue details. 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 our products. 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. Sales with terms f.o.b. shipping point are recognized at the time of shipment. For sales transactions with terms f.o.b. destination, revenue is recorded when the product is delivered to the customer’s site. 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 goods 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 March 30, 2018, an accrual for unpaid customer rebates of $0.3 million is included in accrued expenses on the Company’s Condensed Consolidated Balance Sheet. The adoption of Topic 606 did not have a significant impact on our estimates for variable consideration.

Balance Sheet Information

Balance Sheet Information	3 Months Ended
	Mar. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Information	4. Balance Sheet Information Inventories consisted of the following (in thousands): March 30, December 29, 2018 2017 Raw materials $ 188,553 $ 183,457 Work in process 51,882 43,826 Finished goods 21,363 9,557 Total $ 261,798 $ 236,840 Equipment and leasehold improvements, net, consisted of the following (in thousands): March 30, December 29, 2018 2017 Computer equipment and software $ 11,858 $ 11,672 Furniture and fixtures 3,330 3,318 Machinery and equipment 20,118 19,781 Leasehold improvements 23,734 22,839 Accumulated depreciation (39,727 ) (38,879 ) 19,313 18,731 Construction in progress 17,526 13,515 Total $ 36,839 $ 32,246

Goodwill and Purchased Intangib

Goodwill and Purchased Intangible Assets	3 Months Ended
	Mar. 30, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Purchased Intangible Assets	5. Goodwill and Purchased Intangible Assets The Company’s methodology for allocating the purchase price relating to purchase acquisitions is determined through established and generally accepted valuation techniques. Goodwill is measured as the excess of the cost of the acquisition 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. 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. 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 it is concluded that this is the case, the Company then performs the two-step goodwill impairment test. Otherwise, the two-step goodwill impairment test is not required. Under the two-step goodwill impairment test, the Company would in the first step compare the estimated fair value of each reporting unit to its carrying value. The Company determines the fair value of each of its reporting units based on a weighting of income and market approaches. If the carrying value of a reporting unit exceeds its fair value, the Company would then perform the second step of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the Company determines that the carrying value of a reporting unit’s goodwill exceeds its implied fair value, the Company would record an impairment charge equal to the difference. The evaluation of goodwill and intangible assets for impairment requires the exercise of significant judgment. In the event of future changes in business conditions, the Company will be required to reassess and update its forecasts and estimates used in future impairment analyses. If the results of these future analyses are lower than current estimates, a material impairment charge may result at that time. Details of goodwill and other intangible assets were as follows (in thousands): March 30, 2018 December 29, 2017 Intangible Intangible Goodwill Assets Total Goodwill Assets Total Carrying amount $ 85,248 $ 30,489 $ 115,737 $ 85,248 $ 31,587 $ 116,835 Purchased 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 lives 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 purchased intangible assets were as follows (in thousands): As of March 30, 2018 As of December 29, 2017 Gross Gross Carrying Accumulated Carrying Carrying Accumulated Carrying Useful Amount Amortization Value Amount Amortization Value Life AIT Customer relationships $ 19,000 $ (18,153 ) $ 847 $ 19,000 $ (17,998 ) $ 1,002 7 Tradename 1,900 (1,900 ) — 1,900 (1,900 ) — 6 Intellectual property/know-how 1,600 (1,314 ) 286 1,600 (1,257 ) 343 7 Marchi Customer relationships 9,900 (3,135 ) 6,765 9,900 (2,887 ) 7,013 10 Tradename 1,170 (1,170 ) — 1,170 (1,170 ) — 6 Intellectual property/know-how 12,300 (4,367 ) 7,933 12,300 (4,023 ) 8,277 8-12 Miconex Customer relationships 8,800 (3,129 ) 5,671 8,800 (2,835 ) 5,965 7.5 UCT Tradename 8,987 — 8,987 8,987 — 8,987 * Total $ 63,657 $ (33,168 ) $ 30,489 $ 63,657 $ (32,070 ) $ 31,587 * The Company concluded that the UCT tradename intangible asset life 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 intellectual property/know-how and customer relationships intangible assets for Marchi and Miconex on a straight-line basis with an estimated economic life of the assets ranging from 7 to 12 years. Amortization expense was approximately $1.1 million and $1.2 million for the three months ended March 30, 2018 and March 31, 2017, respectively. Amortization expense is charged to general and administrative expense. As of March 30, 2018, future estimated amortization expense is expected to be as follows (in thousands): Amortization Expense 2018 (remaining in year) $ 3,293 2019 4,040 2020 3,543 2021 3,543 2022 3,543 Thereafter 3,540 Total $ 21,502

Borrowing Arrangements

Borrowing Arrangements	3 Months Ended
	Mar. 30, 2018
Debt Disclosure [Abstract]
Borrowing Arrangements	6. Borrowing Arrangements The Company has credit facilities in the U.S. and Czech Republic that expire on February 2, 2019 and March 31, 2020, respectively. The Company and certain of its subsidiaries have agreed to secure all of their obligations under a credit agreement (the “Credit Agreement”) by granting a first priority lien in substantially all of their respective personal property assets (subject to certain exceptions and limitations). As of March 30, 2018, the interest rates on the outstanding Term Loan and Revolving Credit facility were 3.65% (2.0% fixed and 1.65% variable based on LIBOR) and 3.75% fixed, respectively. In order to manage interest rate risk on the variable component of the Term Loan the Company entered into an interest rate swap with the Lenders in September 2015 with a total notional amount of $20.0 million pursuant to which the Company pays the counterparty a fixed rate of 0.99% and receives interest at a variable rate equal to the LIBOR rate the Company is required to pay under its Term Loan, or 1.65%, as of March 30, 2018. This interest rate swap effectively locked in a fixed interest rate of 2.99% on $6.2 million of the $7.4 million term loan balance outstanding as of March 30, 2018, with a decreasing notional amount based on principal payments over the remaining period of the term loan. The Credit Agreement requires the Company to maintain certain financial covenants including a consolidated fixed charge coverage ratio (as defined in the Credit Agreement) of at least 1.25 to 1.00 starting with the end of the first quarter of fiscal 2015 and a consolidated leverage ratio (as defined in the Credit Agreement) no greater than 3.5 to 1.00 starting with the end of the first quarter of fiscal 2015. The Credit Agreement also includes other customary affirmative and negative covenants. In December 2015, the Credit Agreement was amended to add a covenant requiring the Company to maintain a minimum cash balance of $35.0 million at the end of each quarter. The Company was in compliance with all covenants for the quarter ended March 30, 2018. 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 fair value of the Company’s outstanding borrowings under the Company’s revolving credit facility was based on Level 2 inputs, and fair value was determined using inputs other than quoted prices that are observable, specifically, discounted cash flows of expected payments at current borrowing rates. The Company’s carrying value approximates fair value for the Company’s long term debt and revolving credit facility. As of March 30, 2018, the Company had outstanding amounts under the Term Loan and Revolving Credit Facility of $7.4 million and $39.9 million, respectively, which are gross of unamortized debt issuance costs of $0.1 million, for a total debt balance with this credit facility of $47.2 million. As of March 30, 2018, Miconex had outstanding amount under a revolving credit facility of 6.1 million euros (approximately $7.6 million) with an interest rate of 1.3% plus a variable rate based on the Euro Interbank Offered Rate. As of March 30, 2018, the Company’s total bank debt was $54.8 million. As of March 30, 2018, the Company had $0.1 million and 2.1 million euros (approximately $2.6 million) available to borrow on our revolving credit facilities in the U.S. and Czech Republic, respectively.

Income Tax

Income Tax	3 Months Ended
	Mar. 30, 2018
Income Tax Disclosure [Abstract]
Income Tax	7. Income Tax On December 22, 2017, the U.S. government enacted the Tax Cuts and Jobs Act of 2017 (TCJA). The TCJA significantly revised the future ongoing U.S. corporate income tax by, among other things, lowering U.S. corporate income tax rates from 35% to 21% and implementing a territorial tax system. Other provisions included an immediate deduction for qualified investments and limitations on the deductibility of interest expense and executive compensation. In December 2017, the SEC issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), which allows companies to record provisional amounts during a measurement period not to extend more than one year beyond the Act enactment date. Since the TCJA was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation are expected during the year, the Company considers the accounting for deferred tax remeasurements, the impact of the transition of U.S. international taxation from a worldwide tax system to a territorial system and other provisions to be incomplete. There have been no material changes to the provisional adjustments disclosed in the Company’s 2017 Form 10-K. The Company is continuing to evaluate the estimates used to record and disclose the effects of the Tax Act. Effective January 1, 2018, the TCJA created a new requirement to include in U.S. income global intangible low-taxed income (GILTI) earned by controlled foreign corporations (“CFC”). The effect of GILTI, and the associated foreign tax credit, is to effectively create a minimum floor of taxation on CFC profits that must be included currently in the gross income of the CFCs’ U.S. shareholder. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). During the first quarter of 2018, the Company selected the period cost method in recording the tax effects of GILTI in its financial statements. The Company’s income tax provision and effective tax rates for the three months ended March 30, 2018 and March 31, 2017 were $2.5 million and 9.2% compared to $4.5 million and 23.9%, respectively. The change in respective rates reflects, primarily, the recently enacted TCJA as discussed above, changes in the geographic mix of worldwide earnings and financial results in jurisdictions which are taxed at different rates, the impact of losses in jurisdictions with full federal and state valuation allowances and tax benefits associated with share-based compensation for the three months ended March 30, 2018 Company management continuously evaluates the need for a valuation allowance and, as of March 30, 2018, concluded that a full valuation allowance on its federal and state deferred tax assets as well as the deferred tax assets of one its Singapore subsidiaries was still appropriate. The Company provides for U.S. income taxes on its undistributed earnings of foreign subsidiaries as required by the TCJA. However, the Company does not provide for any withholding taxes on its undistributed earnings of its subsidiaries that it intends to invest indefinitely outside the U.S. In prior years, the Company determined that a portion of the current year earnings of one of its China subsidiaries may be remitted in the future to one of its foreign subsidiaries outside of mainland China and, accordingly, the Company provided for the related withholding taxes in its condensed consolidated financial statements. The Company does not currently plan to remit any earnings from its China subsidiaries to any other foreign subsidiary in 2018. If the Company changes its intent to reinvest its undistributed foreign earnings indefinitely or if a greater amount of undistributed earnings are 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 March 30, 2018, the Company had undistributed earnings of foreign subsidiaries that are indefinitely invested outside of the U.S. of approximately $193.1 million. It is not practicable to determine the tax liability that might be incurred if these earnings were to be distributed. The Company’s gross liability for unrecognized tax benefits as of March 30, 2018 and March 31, 2017 was $0.3 million and $0.3 million, respectively. Although it is possible some of the unrecognized tax benefits could be settled within the next twelve months, the Company cannot reasonably estimate the outcome at this time.

Net Income Per Share

Net Income Per Share	3 Months Ended
	Mar. 30, 2018
Earnings Per Share [Abstract]
Net Income Per Share	8. Net Income Per Share Basic net income per share excludes dilution and is computed by dividing net income by the weighted average number of common shares outstanding for the period. Diluted net income per share reflects the potential dilution that would occur if outstanding securities or other contracts to issue common stock were exercised or converted into common stock. The following is a reconciliation of the numerators and denominators used in computing basic and diluted net income (loss) per share (in thousands, except per share data): Three Months Ended March 30, March 31, 2018 2017 Numerator: Net income $ 24,741 $ 14,341 Denominator: Shares used in computation — basic: Weighted average common shares outstanding 36,723 33,061 Shares used in computation — diluted: Shares used in computing basic net income per share 36,723 33,061 Dilutive effect of common shares outstanding subject to repurchase 761 793 Dilutive effect of options outstanding 7 11 Weighted average shares used in computing diluted net income per share 37,491 33,865 Net income per share — basic $ 0.67 $ 0.43 Net income per share — diluted $ 0.66 $ 0.42 On February 2, 2018, the Company successfully completed a follow-on offering whereby the Company issued 4,761,905 shares of its common stock. The weighted average impact for the quarter was 2,982,732 shares. The Company had securities outstanding which could potentially dilute basic net income per share in the future, but the incremental shares from the assumed exercise of these securities were excluded in the computation of diluted net income per share, as their effect would have been anti-dilutive. Such outstanding securities consisted of 94,962 for the three month period ended March 31, 2017 and none for the three months ended

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies The Company had commitments to purchase inventory totaling approximately $192.9 million at March 30, 2018. The Company leases properties domestically in Hayward, California, Austin, Texas, Chandler, Arizona and South San Francisco, California and internationally in China, Singapore, the Philippines and the Czech Republic. The Company leases certain of its facilities under non-cancelable leases, which expire on various dates through 2023. As of March 30, 2018, future minimum payments under these operating leases were as follows (in thousands): Fiscal Year 2018 (remaining in year) $ 6,165 2019 6,022 2020 5,172 2021 4,640 2022 3,840 Thereafter 116 Total minimum lease payments $ 25,955 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 cannot be predicted with certainty, the Company has not had a history of outcomes to date that have been material to the statement 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 or results of operations. On January 29, 2018, the Company disclosed that the former shareholders of Miconex were disputing the Company’s determination that Miconex failed to achieve the specified performance target applicable to the potential cash “earn-out” payments under the acquisition agreement for the second annual performance period ended July 2017. The Company followed the dispute resolution provisions of the acquisition agreement. In April 2018, the dispute was resolved in favor of the Company and, therefore, no charges related to this dispute were recorded.

Geographical Information

Geographical Information	3 Months Ended
	Mar. 30, 2018
Geographical Information [Abstract]
Geographical Information	10. Geographical Information The Company’s principal markets include North America, Asia and Europe. The Company’s foreign operations are conducted primarily through its wholly-owned subsidiaries in China, Singapore and the Czech Republic. Sales by geographic area represent sales to unaffiliated customers and are based upon the location to which the products were shipped. The following table sets forth revenue by geographic area (in thousands): Three Months Ended March 30, March 31, 2018 2017 United States $ 184,775 $ 104,356 China 2,166 12,947 Singapore 102,633 60,240 Austria 13,535 11,221 Other 11,733 15,830 $ 314,842 $ 204,594 At March 30, 2018, approximately $10.6 million and $1.6 million of the Company’s net long-lived assets were located in Asia and the Czech Republic, respectively, and the remaining balances were located in the United States. At March 31, 2017, approximately $6.9 million and $1.6 million of the Company’s net long-lived assets were located in Asia and the Czech Republic, respectively, and the remaining balances were located in the United States.

Organization and Significant 17

Organization and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 30, 2018
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 wholly-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 29, 2017 balance sheet data were derived from its audited financial statements as of that date.
Principles of Consolidation	Principles of Consolidation — The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries and all intercompany accounts and transactions have been eliminated in consolidation. 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.
Foreign Currency Translation and Remeasurement	Foreign Currency Translation and Remeasurement — The Company has one foreign subsidiary whose functional currency is not its local currency or the U.S. dollar. The Company remeasures the monetary assets and liabilities of this subsidiary into its functional currency. Gains and losses from these remeasurements are recorded in interest and other income (expense), net. The Company then translates the assets and liabilities of this subsidiary into the U.S. dollar. Gains and losses from these translations are recognized in foreign currency translation included in accumulated other comprehensive income (AOCI) within 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 interest and other income (expense), net.
Use of Accounting Estimates	Use of Accounting Estimates — The presentation of financial statements in conformity with accounting principles generally accepted in the United States of America 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 reserves on inventory, valuation of deferred tax assets and impairment of goodwill and other 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 adjustment. Actual amounts may differ from those estimates.
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 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
Fair Value of Measurements	Fair Value of Measurements — The Company measures its cash equivalents, in terest rate swap contract and forward contracts 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. 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 (in thousands): Fair Value Measurement at Reporting Date Using Description March 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets: Interest rate swap $ 24 $ — $ 24 $ — Forward contracts $ 1,281 $ — $ 1,281 $ — Fair Value Measurement at Reporting Date Using Description December 29, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets: Interest rate swap $ 30 $ — $ 30 $ — Forward contracts $ 1,302 $ — $ 1,302 $ —
Derivative Financial Instruments	Derivative Financial Instruments — 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 interest and 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 standard 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 as to 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.
Equipment and Leasehold Improvements, net	Equipment and Leasehold Improvements, net — Equipment and leasehold improvements are stated at cost, or, in the case of equipment under capital leases, the present value of future minimum lease payments at inception of the related lease. 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 fifteen years.
Internal use software	Internal use software — Direct costs incurred to develop software for internal use are capitalized and amortized over an estimated useful life of three to five years. Costs related to the design or maintenance of internal use software are expensed as incurred. Capitalized internal use software is included in computer equipment and software.
Construction in Progress	Construction in progress — Construction in progress is related to the construction or development of property and equipment that has not yet been placed in service for their intended use and is, therefore, not depreciated. Construction in progress currently includes capitalized costs related to the Company’s Enterprise Resource Planning (“ERP”) implementation project.
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 state, federal, 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. The Company continued to maintain a full valuation allowance on its federal, state, and one of its Singapore subsidiary’s deferred tax amounts as of March 30, 2018. Income tax positions must meet a more likely than not recognition threshold to be recognized. Income tax positions that previously failed to meet the more likely than not threshold are recognized in the first subsequent financial reporting period in which that threshold is met. Previously recognized tax positions that no longer meet the more likely than not threshold are derecognized in the first subsequent financial reporting period in which that threshold is no longer met. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits within the Condensed Consolidated Statements of Operations as income tax expense. The calculation of tax liabilities involves significant judgment in estimating the impact of uncertainties in the application of complex tax laws. Resolution of these uncertainties in a manner inconsistent with the Company’s expectations could have a material impact on its results of operations and financial position. Management believes that it has adequately provided for any adjustments that may result from these examinations; however, the outcome of tax audits cannot be predicted with certainty. The determination of the Company’s tax provision is subject to judgments and estimates.
Revenue Recognition	Revenue Recognition — See Note 3 to the Company’s Condensed Consolidated Financial Statements.
Research and Development Costs	Research and Development Costs — Research and development costs are expensed as 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 stock options and restricted stock using the treasury stock method, except when such shar es are anti-dilutive. See Note 7 to the Company’s Condensed Consolidated Financial Statements.
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 considered to be the Chief Executive Officer. The Company operates in one operating segment, and therefore, has one reportable segment.
Business Combinations	Business Combinations — The Company recognizes assets acquired (including goodwill and identifiable intangible assets) and liabilities assumed 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.
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, directors and certain employees. These equity-based awards include stock options, restricted stock awards (“RSAs”) and restricted stock units (“RSUs”) which can be either time-based or performance-based. The Company has not granted stock options to its employees since fiscal year 2010. The Company also maintains an employee stock purchase plan that provides for the issuance of shares to all eligible employees of the Company at a discounted price. Stock-based compensation expense includes compensation costs related to estimated fair values of stock options and 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, typically three years for RSUs and one year for RSAs, and is adjusted for subsequent changes in estimated forfeitures related to all equity-based awards and performance as it relates to performance-based RSUs. The Company applies the fair value recognition provisions based on the FASB’s guidance regarding stock-based compensation.
Employee Stock Purchase Plan	Employee Stock Purchase Plan 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. Under the ESPP, substantially all employees may purchase the Company’s common stock through payroll deductions at a price equal to 95 percent of the fair market value of the Company’s stock at the end of each applicable purchase period.
Restricted Stock Units and Restricted Stock Awards	Restricted Stock Units and Restricted Stock Awards The Company grants RSUs to employees and RSAs to non-employee directors as part of the Company’s long term equity compensation plan. Restricted Stock Units — RSUs are granted to employees with a per share or unit purchase price of zero dollars and either have time based or performance based vesting. RSUs typically vest over three years, subject to the employee’s continued service with the Company. 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. The expected cost of the grant is reflected over the service period, and is reduced for estimated forfeitures. During the quarter ended March 30, 2018 the Company granted 174,900 RSUs, with a weighted average fair value of $19.57 per share, and granted 87,050 performance stock units with a weighted average fair value of $19.25 per share Restricted Stock Awards — As of March 30, 2018, a total of 45,000 RSAs were outstanding. The total unamortized expense of the Company’s unvested restricted stock awards as of March 30, 2018 was $0.1 million. The following table summarizes the Company’s RSU, PSU and RSA activity for the three months ended March 30, 2018: Shares Aggregate Fair (in thousands) Unvested restricted stock units and restricted stock awards at December 29, 2017 1,676,312 $ 38,706 Granted 261,950 Vested (387,071 ) Forfeited (16,941 ) Unvested restricted stock units and restricted stock awards at March 30, 2018 1,534,250 $ 29,534 Vested and expected to vest restricted stock units and restricted stock awards at March 30, 2018 1,297,887 $ 24,984 The following table shows the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations (in thousands): Three Months Ended March 30, March 31, 2018 2017 Cost of sales (1) $ 506 $ 343 Research and development 61 53 Sales and marketing 202 124 General and administrative 1,794 862 2,563 1,382 Income tax benefit (236 ) (330 ) Stock-based compensation expense, net of tax $ 2,327 $ 1,052 (1) Stock-based compensation expenses capitalized in inventory for the three months ended March 30, 2018 and March 31, 2017 was not significant.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Effective December 30, 2017, the Company adopted FASB Accounting Standards Codification (ASC) Revenue from Contracts with Customers (Topic 606) Our implementation team consisted of senior leadership from finance, legal, sales and operations with periodic progress reporting to management and to the audit committee of our board of directors. Implementation consisted of a review of the Company’s significant contracts and an evaluation of our systems and control environment to support additional disclosures under the new standard, as well as updates to our policies and procedures. During our assessment, we considered whether the adoption would require a transition from point-in-time revenue recognition to an over-time approach for products produced by us without an alternative use, which would result in acceleration of revenue. We concluded based on enforceable rights or prevailing terms and conditions included in the agreements with our customers, an enforceable right of payment that includes a reasonable profit throughout the duration of the contract does not exist. Therefore, we will remain at a point-in-time approach and record revenue at the point control transfers to our customers. Beginning fiscal 2018, the Company adopted ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, Beginning fiscal 2018, the Company adopted ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business Beginning fiscal 2018, the Company adopted ASU No. 2017-09, Stock Compensation: Scope of Modification Accounting n. The new guidance requires the application of modification accounting if the value, vesting conditions or classification of the award changes.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued Accounting Standards Update (ASU) No. 2016-02, Leases (Topic 842) . Topic 842 supersedes the lease recognition requirements in ASC Topic 840, Leases. The guidance specifies that an entity who is a lessee under lease agreements should recognize lease assets and lease liabilities for those leases classified as operating leases under previous FASB guidance. The guidance is effective beginning in the first quarter of 2019. Early adoption is permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company is evaluating the impact of adopting this guidance on the Company’s consolidated financial statements. The Company currently expects that its operating lease commitment will be subject to the new standard and recognized as right-of-use asset and operating lease liability upon adoption of this standard, which will increase the total assets and total liabilities that it reports relative to such amounts prior to adoption. In January 2017, the FASB issued Accounting Standards Update No. 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities

Organization and Significant 18

Organization and Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [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 (in thousands): Fair Value Measurement at Reporting Date Using Description March 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets: Interest rate swap $ 24 $ — $ 24 $ — Forward contracts $ 1,281 $ — $ 1,281 $ — Fair Value Measurement at Reporting Date Using Description December 29, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other assets: Interest rate swap $ 30 $ — $ 30 $ — Forward contracts $ 1,302 $ — $ 1,302 $ —
Summary of Restricted Stock Unit, Performance Stock Units and Restricted Stock Award Activity	The following table summarizes the Company’s RSU, PSU and RSA activity for the three months ended March 30, 2018: Shares Aggregate Fair (in thousands) Unvested restricted stock units and restricted stock awards at December 29, 2017 1,676,312 $ 38,706 Granted 261,950 Vested (387,071 ) Forfeited (16,941 ) Unvested restricted stock units and restricted stock awards at March 30, 2018 1,534,250 $ 29,534 Vested and expected to vest restricted stock units and restricted stock awards at March 30, 2018 1,297,887 $ 24,984
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 (in thousands): Three Months Ended March 30, March 31, 2018 2017 Cost of sales (1) $ 506 $ 343 Research and development 61 53 Sales and marketing 202 124 General and administrative 1,794 862 2,563 1,382 Income tax benefit (236 ) (330 ) Stock-based compensation expense, net of tax $ 2,327 $ 1,052 (1) Stock-based compensation expenses capitalized in inventory for the three months ended March 30, 2018 and March 31, 2017 was not significant.

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Mar. 30, 2018
Investments All Other Investments [Abstract]
Schedule of Derivative Instruments at Gross Fair Value	The following tables show the Company’s derivative instruments at gross fair value (in thousands) as of March 30, 2018 and December 29, 2017. March 30, 2018 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total Location Hedge Instruments Hedge Instruments Fair Value Derivative assets and liabilities: Level 2: Interest rate swap Prepaid expenses and other $ 24 $ — $ 24 Forward contracts Prepaid expenses and other $ 150 $ 591 $ 741 Forward contracts Other non-current assets $ 118 $ 422 $ 540 December 29, 2017 Fair Value of Fair Value of Derivatives Derivatives Not Balance Sheet Designated as Designated as Total Location Hedge Instruments Hedge Instruments Fair Value Derivative assets and liabilities: Level 2: Interest rate swap Prepaid expenses and other $ 30 $ — $ 30 Forward contracts Prepaid expenses and other $ 714 $ — $ 714 Forward contracts Other non-current assets $ 588 $ — $ 588
Effect of Derivative Instruments in Cash Flow Hedging Relationships on Income and Other Comprehensive Income	The effect of derivative instruments in cash flow hedging relationships on income and other comprehensive income (OCI) is summarized below (in thousands): Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion) Three Months Ended March 30, March 31, 2018 2017 Derivatives in Cash Flow Hedging Relationship Interest rate swap $ (15 ) $ 13 Forward contracts $ 24 $ — Gains Reclassified from AOCI into Income (Effective Portion) Three Months Ended March 30, March 31, Income Statement Location 2018 2017 Derivatives in Cash Flow Hedging Relationship Interest rate swap Interest and other income (expense), net $ 10 $ 7 Forward contracts Cost of goods sold $ 42 $ —

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 30, 2018
Revenue From Contract With Customer [Abstract]
Customers as Percentage of Total Sales	The Company’s most significant customers (having accounted for 10% or more of sales) and their related sales as a percentage of total sales were as follows: Three Months Ended March 30, March 31, 2018 2017 Lam Research Corporation 66.2 % 58.7 % Applied Materials, Inc. 21.4 26.9 Total 87.6 % 85.6 %

Balance Sheet Information (Tabl

Balance Sheet Information (Tables)	3 Months Ended
	Mar. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Inventories	Inventories consisted of the following (in thousands): March 30, December 29, 2018 2017 Raw materials $ 188,553 $ 183,457 Work in process 51,882 43,826 Finished goods 21,363 9,557 Total $ 261,798 $ 236,840
Equipment and Leasehold Improvements, Net	Equipment and leasehold improvements, net, consisted of the following (in thousands): March 30, December 29, 2018 2017 Computer equipment and software $ 11,858 $ 11,672 Furniture and fixtures 3,330 3,318 Machinery and equipment 20,118 19,781 Leasehold improvements 23,734 22,839 Accumulated depreciation (39,727 ) (38,879 ) 19,313 18,731 Construction in progress 17,526 13,515 Total $ 36,839 $ 32,246

Goodwill and Purchased Intang22

Goodwill and Purchased Intangible Assets (Tables)	3 Months Ended
	Mar. 30, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Indefinite Lived Intangible Assets	Details of goodwill and other intangible assets were as follows (in thousands): March 30, 2018 December 29, 2017 Intangible Intangible Goodwill Assets Total Goodwill Assets Total Carrying amount $ 85,248 $ 30,489 $ 115,737 $ 85,248 $ 31,587 $ 116,835
Details of Purchased Intangible Assets	Details of purchased intangible assets were as follows (in thousands): As of March 30, 2018 As of December 29, 2017 Gross Gross Carrying Accumulated Carrying Carrying Accumulated Carrying Useful Amount Amortization Value Amount Amortization Value Life AIT Customer relationships $ 19,000 $ (18,153 ) $ 847 $ 19,000 $ (17,998 ) $ 1,002 7 Tradename 1,900 (1,900 ) — 1,900 (1,900 ) — 6 Intellectual property/know-how 1,600 (1,314 ) 286 1,600 (1,257 ) 343 7 Marchi Customer relationships 9,900 (3,135 ) 6,765 9,900 (2,887 ) 7,013 10 Tradename 1,170 (1,170 ) — 1,170 (1,170 ) — 6 Intellectual property/know-how 12,300 (4,367 ) 7,933 12,300 (4,023 ) 8,277 8-12 Miconex Customer relationships 8,800 (3,129 ) 5,671 8,800 (2,835 ) 5,965 7.5 UCT Tradename 8,987 — 8,987 8,987 — 8,987 * Total $ 63,657 $ (33,168 ) $ 30,489 $ 63,657 $ (32,070 ) $ 31,587 * The Company concluded that the UCT tradename intangible asset life 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 March 30, 2018, future estimated amortization expense is expected to be as follows (in thousands): Amortization Expense 2018 (remaining in year) $ 3,293 2019 4,040 2020 3,543 2021 3,543 2022 3,543 Thereafter 3,540 Total $ 21,502

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
	Mar. 30, 2018
Earnings Per Share [Abstract]
Basic and Diluted Net Income (loss) Per Share	The following is a reconciliation of the numerators and denominators used in computing basic and diluted net income (loss) per share (in thousands, except per share data): Three Months Ended March 30, March 31, 2018 2017 Numerator: Net income $ 24,741 $ 14,341 Denominator: Shares used in computation — basic: Weighted average common shares outstanding 36,723 33,061 Shares used in computation — diluted: Shares used in computing basic net income per share 36,723 33,061 Dilutive effect of common shares outstanding subject to repurchase 761 793 Dilutive effect of options outstanding 7 11 Weighted average shares used in computing diluted net income per share 37,491 33,865 Net income per share — basic $ 0.67 $ 0.43 Net income per share — diluted $ 0.66 $ 0.42

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Payments under Operating Leases	As of March 30, 2018, future minimum payments under these operating leases were as follows (in thousands): Fiscal Year 2018 (remaining in year) $ 6,165 2019 6,022 2020 5,172 2021 4,640 2022 3,840 Thereafter 116 Total minimum lease payments $ 25,955

Geographical Information (Table

Geographical Information (Tables)	3 Months Ended
	Mar. 30, 2018
Geographical Information [Abstract]
Revenue by Geographic Area	The following table sets forth revenue by geographic area (in thousands): Three Months Ended March 30, March 31, 2018 2017 United States $ 184,775 $ 104,356 China 2,166 12,947 Singapore 102,633 60,240 Austria 13,535 11,221 Other 11,733 15,830 $ 314,842 $ 204,594

Organization and Significant 26

Organization and Significant Accounting Policies - Additional Information (Detail)	3 Months Ended
	Mar. 30, 2018Segment
Concentration Risk [Line Items]
Number of operating segments	1
Number of reportable segments	1
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	15 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	5 years

Organization and Significant 27

Organization and Significant Accounting Policies - Assets or Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Forward Contracts [Member]
Other assets:
Assets measured at fair value	$ 1,281	$ 1,302
Interest Rate Swap [Member]
Other assets:
Assets measured at fair value	24	30
Significant Other Observable Inputs (Level 2) [Member] | Forward Contracts [Member]
Other assets:
Assets measured at fair value	1,281	1,302
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap [Member]
Other assets:
Assets measured at fair value	$ 24	$ 30

Organization and Significant 28

Organization and Significant Accounting Policies - Additional Information 1 (Detail)	3 Months Ended
	Mar. 30, 2018USD ($)$ / sharesshares
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period, years	3 years
Granted stock units	174,900
Weighted average fair value, granted | $ / shares	$ 19.57
Vested shares withheld to satisfy withholding tax obligations	92,410
Vested shares issued net of tax withholdings	294,661
Stock-based compensation cost, net of estimated forfeitures, recognized | $	$ 14,100,000
Outstanding restricted stock	1,489,250
Aggregate fair value | $	$ 28,700,000
Weighted average remaining contractual term (in years)	1 year 2 months 12 days
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
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting period, years	1 year
Restricted Stock Awards [Member] | Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding restricted stock	45,000
Unamortized expense of company's unvested restricted stock awards | $	$ 100,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee common stock fair market value rate	95.00%
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted stock units	87,050
Weighted average fair value, granted | $ / shares	$ 19.25
Stock-based compensation cost, net of estimated forfeitures, recognized | $	$ 14,100,000
Outstanding restricted stock	1,489,250
Aggregate fair value | $	$ 28,700,000
Weighted average remaining contractual term (in years)	1 year 2 months 12 days
Performance 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

Organization and Significant 29

Organization and Significant Accounting Policies - 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] - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Dec. 29, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units and restricted stock awards, Number of Shares, Beginning balance	1,676,312
Granted, Number of Shares	261,950
Vested, Number of Shares	(387,071)
Forfeited, Number of Shares	(16,941)
Unvested restricted stock units and restricted stock awards, Number of Shares, Ending balance	1,534,250
Vested and expected to vest restricted stock units and restricted stock awards, Number of Shares	1,297,887
Unvested restricted stock units and restricted stock awards, Aggregate Intrinsic Value	$ 29,534	$ 38,706
Vested and expected to vest restricted stock units and restricted stock awards, Aggregate Intrinsic Value	$ 24,984

Organization and Significant 30

Organization and Significant Accounting Policies - Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 2,563	$ 1,382
Income tax benefit	(236)	(330)
Stock-based compensation expense, net of tax	2,327	1,052
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	506	343
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	61	53
Sales and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	202	124
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,794	$ 862

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017	Sep. 30, 2015
Financial Instruments [Line Items]
Effect of derivative instruments not designated as hedging instruments on income	$ 1,000,000
Miconex [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Financial Instruments [Line Items]
Non-Designated Derivatives, description	A portion of Miconex’s forward contracts with a total notional amount of $5.8 million is not designated as a hedging instrument. The Company recognizes gains and losses on these contracts, as well any related costs, in interest and other income (expense), net.
Forward Contracts [Member] | Miconex [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Financial Instruments [Line Items]
Derivative instrument, notional amount	$ 5,800,000
Maximum [Member]
Financial Instruments [Line Items]
Effective portion of cash flow hedge before tax effect	100,000
Cash flow hedge, expected to be reclassified from AOCI into earnings	100,000
Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Outstanding amounts	$ 7,400,000
Interest Rate Swap [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Derivative instrument, notional amount			$ 20,000,000
East West Bank and City National Bank [Member] | Interest Rate Swap [Member]
Financial Instruments [Line Items]
Derivative instrument, notional amount			$ 20,000,000
Credit Agreement [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Debt instrument interest rate	2.00%
Outstanding amounts	$ 7,400,000
Credit Agreement [Member] | Interest Rate Swap [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Derivative instrument, notional amount	$ 6,200,000
Debt instrument LIBOR rate			0.99%
Debt instrument interest rate	2.99%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Debt instrument variable interest rate	1.65%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Interest Rate Swap [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Debt instrument variable interest rate	1.65%
Derivatives in Cash Flow Hedging Relationship [Member]
Financial Instruments [Line Items]
Gains (losses) recognized in income on derivatives that are excluded from effectiveness testing and ineffective portion	$ 0	$ 0
Derivatives in Cash Flow Hedging Relationship [Member] | East West Bank and City National Bank [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Debt instrument interest rate	2.99%
Outstanding amounts	$ 7,400,000
Derivatives in Cash Flow Hedging Relationship [Member] | East West Bank and City National Bank [Member] | Interest Rate Swap [Member] | Term Loan Credit Facility [Member]
Financial Instruments [Line Items]
Derivative instrument, notional amount	$ 6,200,000

Financial Instruments - Schedul

Financial Instruments - Schedule of Derivative Instruments at Gross Fair Value (Detail) - Significant Other Observable Inputs (Level 2) [Member] - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Forward Contracts [Member] | Prepaid Expenses and Other [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Fair Value of Derivatives Designated as Hedge Instrument	$ 150	$ 714
Derivative assets, Fair Value of Derivatives Not Designated as Hedge Instrument	591
Derivative assets, Total Fair Value	741	714
Forward Contracts [Member] | Other Non-Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Fair Value of Derivatives Designated as Hedge Instrument	118	588
Derivative assets, Fair Value of Derivatives Not Designated as Hedge Instrument	422
Derivative assets, Total Fair Value	540	588
Interest Rate Swap [Member] | Prepaid Expenses and Other [Member]
Derivatives, Fair Value [Line Items]
Derivative assets, Fair Value of Derivatives Designated as Hedge Instrument	24	30
Derivative assets, Total Fair Value	$ 24	$ 30

Financial Instruments - Effect

Financial Instruments - Effect of Derivative Instruments in Cash Flow Hedging Relationships on Income and Other Comprehensive Income (Detail) - Derivatives in Cash Flow Hedging Relationship [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion)	$ (15)	$ 13
Interest Rate Swap [Member] | Interest and Other Income (Expense), Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains Reclassified from AOCI into Income (Effective Portion)	10	$ 7
Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in OCI on Derivatives Before Tax Effect (Effective Portion)	24
Forward Contracts [Member] | Cost of Goods Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains Reclassified from AOCI into Income (Effective Portion)	$ 42

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 30, 2018USD ($)SegmentCustomer	Dec. 29, 2017Customer
Concentration Risk [Line Items]
Number of reportable segments | Segment	1
Accrued Expenses [Member]
Concentration Risk [Line Items]
Unpaid customer rebates | $	$ 0.3
Maximum [Member]
Concentration Risk [Line Items]
Product warranty period (in years)	2 years
Customer Concentration Risk [Member] | Lam Research Corporation and Applied Materials, Inc. [Member]
Concentration Risk [Line Items]
Number of customers with accounts receivable greater than 10% | Customer	2	2
Customer Concentration Risk [Member] | Lam Research Corporation and Applied Materials, Inc. [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration percentage	69.50%	75.80%

Revenue Recognition - Customers

Revenue Recognition - Customers as Percentage of Total Sales (Detail) - Sales [Member] - Customer Concentration Risk [Member]	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Concentration Risk [Line Items]
Total	87.60%	85.60%
Lam Research Corporation [Member]
Concentration Risk [Line Items]
Total	66.20%	58.70%
Applied Materials, Inc. [Member]
Concentration Risk [Line Items]
Total	21.40%	26.90%

Balance Sheet Information - Sum

Balance Sheet Information - Summary of Inventories (Detail) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 188,553	$ 183,457
Work in process	51,882	43,826
Finished goods	21,363	9,557
Total	$ 261,798	$ 236,840

Balance Sheet Information - Equ

Balance Sheet Information - Equipment and Leasehold Improvements, Net (Detail) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (39,727)	$ (38,879)
Equipment and leasehold improvements net excluding construction in progress	19,313	18,731
Construction in progress	17,526	13,515
Total	36,839	32,246
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	11,858	11,672
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	3,330	3,318
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	20,118	19,781
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Equipment and leasehold improvements, gross	$ 23,734	$ 22,839

Goodwill and Purchased Intang38

Goodwill and Purchased Intangible Assets - Goodwill and Other Indefinite Lived Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 30, 2018	Dec. 29, 2017
Intangible Assets Net Including Goodwill [Abstract]
Goodwill	$ 85,248	$ 85,248
Intangible Assets	30,489	31,587
Total	$ 115,737	$ 116,835

Goodwill and Purchased Intang39

Goodwill and Purchased Intangible Assets - Details of Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2017	Mar. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, accumulated amortization	$ (32,070)	$ (33,168)
Definite lives intangible assets, net carrying amount		21,502
Intangible Assets, gross carrying value	63,657	63,657
Intangible Assets, net carrying value	31,587	30,489
American Integration Technologies LLC [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	19,000	19,000
Definite lives intangible assets, accumulated amortization	(17,998)	(18,153)
Definite lives intangible assets, net carrying amount	$ 1,002	847
Useful Life (in years)	7 years
American Integration Technologies LLC [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 1,900	1,900
Definite lives intangible assets, accumulated amortization	$ (1,900)	(1,900)
Useful Life (in years)	6 years
American Integration Technologies LLC [Member] | Intellectual Properties/Know-How [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 1,600	1,600
Definite lives intangible assets, accumulated amortization	(1,257)	(1,314)
Definite lives intangible assets, net carrying amount	$ 343	286
Useful Life (in years)	7 years
Marchi Thermal Systems Inc [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 9,900	9,900
Definite lives intangible assets, accumulated amortization	(2,887)	(3,135)
Definite lives intangible assets, net carrying amount	$ 7,013	6,765
Useful Life (in years)	10 years
Marchi Thermal Systems Inc [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 1,170	1,170
Definite lives intangible assets, accumulated amortization	$ (1,170)	(1,170)
Useful Life (in years)	6 years
Marchi Thermal Systems Inc [Member] | Intellectual Properties/Know-How [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 12,300	12,300
Definite lives intangible assets, accumulated amortization	(4,023)	(4,367)
Definite lives intangible assets, net carrying amount	$ 8,277	7,933
Marchi Thermal Systems Inc [Member] | Intellectual Properties/Know-How [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)	8 years
Marchi Thermal Systems Inc [Member] | Intellectual Properties/Know-How [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful Life (in years)	12 years
Miconex [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 8,800	8,800
Definite lives intangible assets, accumulated amortization	(2,835)	(3,129)
Definite lives intangible assets, net carrying amount	$ 5,965	5,671
Useful Life (in years)	7 years 6 months
UCT [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite lives intangible assets	$ 8,987	$ 8,987

Goodwill and Purchased Intang40

Goodwill and Purchased Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of finite-lived intangibles	$ 1,098	$ 1,231
Minimum [Member] | Intellectual Properties/Know-How [Member] | Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	7 years
Minimum [Member] | Intellectual Properties/Know-How [Member] | Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	7 years
Minimum [Member] | Customer Relationships [Member] | Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	7 years
Minimum [Member] | Customer Relationships [Member] | Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	7 years
Maximum [Member] | Intellectual Properties/Know-How [Member] | Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	12 years
Maximum [Member] | Intellectual Properties/Know-How [Member] | Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	12 years
Maximum [Member] | Customer Relationships [Member] | Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	12 years
Maximum [Member] | Customer Relationships [Member] | Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets	12 years

Goodwill and Purchased Intang41

Goodwill and Purchased Intangible Assets - Future Estimated Amortization Expense (Detail) $ in Thousands	Mar. 30, 2018USD ($)
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
2018 (remaining in year)	$ 3,293
2,019	4,040
2,020	3,543
2,021	3,543
2,022	3,543
Thereafter	3,540
Definite lives intangible assets, net carrying amount	$ 21,502

Borrowing Arrangements - Additi

Borrowing Arrangements - Additional Information (Detail) € in Millions	3 Months Ended
	Mar. 30, 2018USD ($)	Mar. 27, 2015	Mar. 30, 2018EUR (€)	Sep. 30, 2015USD ($)
Debt Instrument [Line Items]
Debt Instrument, covenant description	The Credit Agreement requires the Company to maintain certain financial covenants including a consolidated fixed charge coverage ratio (as defined in the Credit Agreement) of at least 1.25 to 1.00 starting with the end of the first quarter of fiscal 2015 and a consolidated leverage ratio (as defined in the Credit Agreement) no greater than 3.5 to 1.00 starting with the end of the first quarter of fiscal 2015. The Credit Agreement also includes other customary affirmative and negative covenants. In December 2015, the Credit Agreement was amended to add a covenant requiring the Company to maintain a minimum cash balance of $35.0 million at the end of each quarter. The Company was in compliance with all covenants for the quarter ended March 30, 2018.
Minimum [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio for the next fiscal year		1.25%
Required cash balance	$ 35,000,000
First Quarter [Member] | Maximum [Member]
Debt Instrument [Line Items]
Consolidated leverage ratio for first quarter of next fiscal year		3.50%
Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Base rate interest	3.65%
Outstanding amounts	$ 7,400,000
Term Loan Credit Facility [Member] | Interest Rate Swap [Member]
Debt Instrument [Line Items]
Derivative instrument, notional amount				$ 20,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding amounts	39,900,000
Term Loan and Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding amount of borrowing classified as long-term debt	47,200,000
Unamortized debt issuance costs	$ 100,000
Credit Agreement [Member] | Term Loan Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	2.00%		2.00%
Outstanding amounts	$ 7,400,000
Credit Agreement [Member] | Term Loan Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate	1.65%
Credit Agreement [Member] | Term Loan Credit Facility [Member] | Interest Rate Swap [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	2.99%		2.99%
Derivative instrument, notional amount	$ 6,200,000
Debt instrument LIBOR rate				0.99%
Credit Agreement [Member] | Term Loan Credit Facility [Member] | Interest Rate Swap [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument variable interest rate	1.65%
Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Base rate interest	3.75%
Credit Agreement [Member] | U.S. [Member]
Debt Instrument [Line Items]
Credit facility expiration date	Feb. 2, 2019
Credit Agreement [Member] | Czech Republic [Member]
Debt Instrument [Line Items]
Credit facility expiration date	Mar. 31, 2020
Bank Debt [Member]
Debt Instrument [Line Items]
Outstanding amount of borrowing classified as long-term debt	$ 54,800,000
Bank Debt [Member] | U.S. [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Available borrowings under revolving loan	$ 100,000
Bank Debt [Member] | Czech Republic [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	1.30%		1.30%
Bank Debt [Member] | Czech Republic [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Available borrowings under revolving loan	$ 2,600,000		€ 2.1
Bank Debt [Member] | Czech Republic [Member] | Revolving Credit Facility [Member] | Miconex [Member]
Debt Instrument [Line Items]
Outstanding amounts	$ 7,600,000		€ 6.1

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 30, 2018	Mar. 31, 2017	Dec. 29, 2017
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	21.00%		35.00%
Income tax provision	$ 2,493	$ 4,494
Effective tax rate	9.20%	23.90%
Undistributed earnings of foreign subsidiaries	$ 193,100
Gross liability for unrecognized tax benefits	$ 300	$ 300

Net Income Per Share - Basic an

Net Income Per Share - Basic and Diluted Net Income (loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Numerator:
Net income	$ 24,741	$ 14,341
Shares used in computation — basic:
Weighted average common shares outstanding	36,723	33,061
Shares used in computation — diluted:
Shares used in computing basic net income per share	36,723	33,061
Dilutive effect of common shares outstanding subject to repurchase	761	793
Dilutive effect of options outstanding	7	11
Weighted average shares used in computing diluted net income per share	37,491	33,865
Net income per share — basic	$ 0.67	$ 0.43
Net income per share — diluted	$ 0.66	$ 0.42

Net Income Per Share - Addition

Net Income Per Share - Additional Information (Detail) - shares	Feb. 02, 2018	Mar. 30, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Common stock, shares issued	4,761,905
Weighted average impact of shares issued		2,982,732
Antidilutive securities excluded from computation of earnings per share		94,962	0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Apr. 30, 2018	Mar. 30, 2018
Long Term Purchase Commitment [Line Items]
Operating lease expiration period		various dates through 2023
Subsequent Event [Member]
Long Term Purchase Commitment [Line Items]
Charges related to dispute	$ 0
Inventory [Member]
Long Term Purchase Commitment [Line Items]
Purchase commitments		$ 192,900,000

Commitments and Contingencies47

Commitments and Contingencies - Summary of Future Minimum Payments under Operating Leases (Detail) $ in Thousands	Mar. 30, 2018USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2018 (remaining in year)	$ 6,165
2,019	6,022
2,020	5,172
2,021	4,640
2,022	3,840
Thereafter	116
Total minimum lease payments	$ 25,955

Geographical Information - Reve

Geographical Information - Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	$ 314,842	$ 204,594
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	184,775	104,356
China [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	2,166	12,947
Singapore [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	102,633	60,240
Austria [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	13,535	11,221
Other [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	$ 11,733	$ 15,830

Geographical Information - Addi

Geographical Information - Additional Information (Detail) - USD ($) $ in Millions	Mar. 30, 2018	Mar. 31, 2017
Other Asia [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived assets	$ 10.6	$ 6.9
Czech Republic [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived assets	$ 1.6	$ 1.6