Alpha and Omega Semiconductor Limited (AOSL) 10-Q 10 Feb 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Dec. 31, 2019	Jan. 30, 2020
Document and Entity Information [Abstract]
Entity Registrant Name	ALPHA & OMEGA SEMICONDUCTOR Ltd
Entity Central Index Key	0001387467
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Document Type	10-Q
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)		24,782,495
Entity Shell Company	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Current assets:
Cash and cash equivalents	$ 107,249	$ 121,893
Restricted cash	2,216	364
Accounts receivable, net	33,872	24,296
Inventories	117,591	111,643
Other current assets	34,395	37,102
Total current assets	295,323	295,298
Property, plant and equipment, net	416,055	409,737
Operating lease right-of-use assets, net	18,667
Intangible assets, net	16,826	16,882
Deferred income tax assets	4,766	4,822
Restricted cash - long-term	2,001	2,038
Other long-term assets	9,502	10,617
Total assets	763,140	739,394
Current liabilities:
Accounts payable	89,741	94,384
Accrued liabilities	52,694	44,075
Income taxes payable	1,967	1,541
Short-term debt	21,029	26,609
Finance lease liabilities	15,438	11,355
Operating lease liabilities	3,282
Total current liabilities	184,151	177,964
Long-term debt	76,309	59,380
Income taxes payable - long-term	1,020	993
Deferred income tax liabilities	263	466
Finance lease liabilities - long-term	34,878	43,381
Operating lease liabilities - long-term	15,559
Other long-term liabilities	10,810	13,921
Total liabilities	322,990	296,105
Commitments and contingencies (Note 10)
Preferred shares, par value $0.002 per share:
Authorized: 10,000 shares; issued and outstanding: none at December 31, 2019 and June 30, 2019	0	0
Common shares, par value $0.002 per share:
Authorized: 100,000 shares; issued and outstanding: 31,420 shares and 24,776 shares, respectively at December 31, 2019 and 31,163 shares and 24,517 shares, respectively at June 30, 2019	63	62
Treasury shares at cost, 6,644 shares at December 31, 2019 and 6,646 shares at June 30, 2019	(66,227)	(66,240)
Additional paid-in capital	240,797	234,410
Accumulated other comprehensive loss	(4,239)	(2,693)
Retained earnings	125,476	125,485
Total Alpha and Omega Semiconductor Limited shareholder's equity	295,870	291,024
Noncontrolling interest	144,280	152,265
Total equity	440,150	443,289
Total liabilities and equity	$ 763,140	$ 739,394

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Jun. 30, 2019
Common shares, par value (in dollars per share)	$ 0.002	$ 0.002
Common shares, authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	31,420,000	31,163,000
Common stock, shares outstanding (in shares)	24,776,000	24,517,000
Preferred stock, par value (in dollars per share)	$ 0.002	$ 0.002
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury shares (in shares)	6,644,000	6,646,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 117,860	$ 114,925	$ 235,662	$ 229,997
Cost of goods sold	93,454	85,423	184,324	167,884
Gross profit	24,406	29,502	51,338	62,113
Operating expenses
Research and development	12,147	12,600	24,515	23,984
Selling, general and administrative	15,629	20,104	30,814	40,456
Total operating expenses	27,776	32,704	55,329	64,440
Operating loss	(3,370)	(3,202)	(3,991)	(2,327)
Interest and other income (loss), net	(635)	(1,632)	(1,462)	(2,860)
Net loss before income taxes	(4,005)	(4,834)	(5,453)	(5,187)
Income tax expense	568	701	978	1,261
Net loss including noncontrolling interest	(4,573)	(5,535)	(6,431)	(6,448)
Net loss attributable to noncontrolling interest	(3,568)	(3,990)	(6,435)	(7,319)
Net income (loss) attributable to Alpha and Omega Semiconductor Limited	$ (1,005)	$ (1,545)	$ 4	$ 871
Net income (loss) per common share attributable to Alpha and Omega Semiconductor Limited
Basic (in dollars per share)	$ (0.04)	$ (0.06)	$ 0	$ 0.04
Diluted (in dollars per share)	$ (0.04)	$ (0.06)	$ 0	$ 0.04
Weighted average number of common shares attributable to Alpha and Omega Semiconductor Limited used to compute net income (loss) per share
Basic (in shares)	24,701	23,887	24,620	23,865
Diluted (in shares)	24,701	23,887	25,362	24,513

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Net income (loss) including noncontrolling interest	$ (4,573)	$ (5,535)	$ (6,431)	$ (6,448)
Other comprehensive income, net of tax
Foreign currency translation adjustment	3,055	(58)	(3,096)	(6,295)
Comprehensive loss	(1,518)	(5,593)	(9,527)	(12,743)
Noncontrolling interest	(2,150)	(4,014)	(7,985)	(10,332)
Comprehensive income (loss) attributable to Alpha and Omega Semiconductor Limited	$ 632	$ (1,579)	$ (1,542)	$ (2,411)

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Total AOS Shareholders' Equity	Common Shares	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, including portion attributable to noncontrolling interest	$ 426,162
Beginning balance at Jun. 30, 2018		$ 278,594	$ 61	$ (64,790)	$ 220,244	$ 440	$ 122,639	$ 147,568
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, including portion attributable to noncontrolling interest	444,528
Exercise of common stock options and release of RSUs	110	110	0		110
Reissuance of treasury stock upon exercise of common stock options and release of RSUs	0	0		8			(8)
Withholding tax on restricted stock units	(203)	(203)			(203)
Repurchase of common shares under shares repurchase program	(1,501)	(1,501)		(1,501)
Share-based compensation	6,499	6,499			6,499
Net loss	871	871					871
Net loss attributable to noncontrolling interest	(7,319)							(7,319)
Net income (loss) including noncontrolling interest	(6,448)
Impact on retained earnings related to ASC 606 adoption | Accounting Standards Update 2016-16	1,036	1,036					1,036
Cumulative translation adjustment		(3,282)				(3,282)
Cumulative translation adjustment, attributable to noncontrolling interest								(3,013)
Cumulative translation adjustment, including portion attributable to noncontrolling interest	(6,295)
Ending balance at Dec. 31, 2018		283,292	61	(66,283)	227,818	(2,842)	124,538	161,236
Ending balance, including portion attributable to noncontrolling interest at Dec. 31, 2018	444,528
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,168	1,168	0		1,168
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	24,000							24,000
Beginning balance, including portion attributable to noncontrolling interest	421,672
Beginning balance at Sep. 30, 2018		280,422	61	(66,283)	223,369	(2,808)	126,083	141,250
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, including portion attributable to noncontrolling interest	444,528
Exercise of common stock options and release of RSUs	5	5	0		5
Withholding tax on restricted stock units	(94)	(94)			(94)
Share-based compensation	3,370	3,370			3,370
Net loss	(1,545)	(1,545)					(1,545)
Net loss attributable to noncontrolling interest	(3,990)							(3,990)
Net income (loss) including noncontrolling interest	(5,535)
Cumulative translation adjustment		(34)				(34)
Cumulative translation adjustment, attributable to noncontrolling interest								(24)
Cumulative translation adjustment, including portion attributable to noncontrolling interest	(58)
Ending balance at Dec. 31, 2018		283,292	61	(66,283)	227,818	(2,842)	124,538	161,236
Ending balance, including portion attributable to noncontrolling interest at Dec. 31, 2018	444,528
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,168	1,168	0		1,168
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	24,000							24,000
Beginning balance, including portion attributable to noncontrolling interest	444,528
Beginning balance, including portion attributable to noncontrolling interest	443,289
Beginning balance at Jun. 30, 2019	291,024	291,024	62	(66,240)	234,410	(2,693)	125,485	152,265
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, including portion attributable to noncontrolling interest	440,150
Exercise of common stock options and release of RSUs	26	26	0		26
Reissuance of treasury stock upon exercise of common stock options and release of RSUs	0	0		13			(13)
Withholding tax on restricted stock units	(195)	(195)			(195)
Share-based compensation	4,856	4,856			4,856
Net loss	4	4					4
Net loss attributable to noncontrolling interest	(6,435)							(6,435)
Net income (loss) including noncontrolling interest	(6,431)
Cumulative translation adjustment		(1,546)				(1,546)
Cumulative translation adjustment, attributable to noncontrolling interest								(1,550)
Cumulative translation adjustment, including portion attributable to noncontrolling interest	(3,096)
Ending balance at Dec. 31, 2019	295,870	295,870	63	(66,227)	240,797	(4,239)	125,476	144,280
Ending balance, including portion attributable to noncontrolling interest at Dec. 31, 2019	440,150
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,701	1,701	1		1,700
Beginning balance, including portion attributable to noncontrolling interest	437,553
Beginning balance at Sep. 30, 2019		291,123	62	(66,227)	236,683	(5,876)	126,481	146,430
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, including portion attributable to noncontrolling interest	440,150
Exercise of common stock options and release of RSUs	26	26	0		26
Withholding tax on restricted stock units	(99)	(99)			(99)
Share-based compensation	2,487	2,487			2,487
Net loss	(1,005)	(1,005)					(1,005)
Net loss attributable to noncontrolling interest	(3,568)							(3,568)
Net income (loss) including noncontrolling interest	(4,573)
Cumulative translation adjustment		1,637				1,637
Cumulative translation adjustment, attributable to noncontrolling interest								1,418
Cumulative translation adjustment, including portion attributable to noncontrolling interest	3,055
Ending balance at Dec. 31, 2019	295,870	295,870	63	$ (66,227)	240,797	$ (4,239)	$ 125,476	$ 144,280
Ending balance, including portion attributable to noncontrolling interest at Dec. 31, 2019	440,150
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Value, Employee Stock Purchase Plan	1,701	$ 1,701	$ 1		$ 1,700
Beginning balance, including portion attributable to noncontrolling interest	$ 440,150

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income (loss) including noncontrolling interest	$ (6,431)	$ (6,448)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	21,754	16,149
Share-based compensation expense	4,856	7,547
Deferred income taxes, net	(148)	94
Loss (gain) on disposal of property and equipment	89	(6)
Changes in assets and liabilities:
Accounts receivable, net	(9,576)	(326)
Inventories	(4,856)	(12,780)
Other current and long-term assets	940	(696)
Accounts payable	(5,676)	9,927
Income taxes payable	453	(415)
Accrued and other liabilities	6,306	18,035
Net cash provided by operating activities	7,711	31,081
Cash flows from investing activities
Purchases of property and equipment excluding JV Company	(20,354)	(23,218)
Purchases of property and equipment in JV Company	(12,067)	(42,723)
Purchase of intangible assets	0	(405)
Proceeds from sale of property and equipment	0	19
Government grant related to equipment in JV Company	1,254	0
Net cash used in investing activities	(31,167)	(66,327)
Cash flows from financing activities
Proceeds from investment by noncontrolling interest	0	24,000
Withholding tax on restricted stock units	(195)	(203)
Proceeds from exercise of stock options and ESPP	1,727	1,278
Payment for repurchases of common shares	0	(1,501)
Proceeds from borrowings	33,708	36,191
Repayments of borrowings	(20,863)	(7,308)
Principal payments on finance lease	(3,403)	(417)
Net cash provided by financing activities	10,974	52,040
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(347)	(1,631)
Net increase (decrease) in cash, cash equivalents and restricted cash	(12,829)	15,163
Cash, cash equivalents and restricted cash at beginning of period	124,295	131,724
Cash, cash equivalents and restricted cash at end of period	111,466	146,887
Supplemental disclosures of non-cash investing and financing information:
Property and equipment purchased but not yet paid (2018 amount is presented as revised, see Note 1)	$ 18,165	$ 30,335

The Company and Significant Acc

The Company and Significant Accounting Policies	6 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Significant Accounting Policies	The Company and Significant Accounting Policies The Company Alpha and Omega Semiconductor Limited and its subsidiaries (the “Company”, "AOS", "we" or "us") design, develop and supply a broad range of power semiconductors. The Company's portfolio of products targets high-volume applications, including personal computers, flat panel TVs, LED lighting, smart phones, battery packs, quick chargers, home appliances, consumer and industrial motor controls and power supplies for TVs, computers, servers and telecommunications equipment. The Company conducts its operations primarily in the United States of America (“USA”), Hong Kong, China, and South Korea. Basis of Preparation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2019 . All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the periods presented have been included in the interim periods. Operating results for the six months ended December 31, 2019 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2020 or any other interim period. The condensed consolidated balance sheet at June 30, 2019 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2019 . During the six months ended December 31, 2019 , the Company corrected the prior year amount of property and equipment purchased but not yet paid in the supplemental disclosures of non-cash investing and financing information by decreasing it by $31.3 million , from $61.6 million to $30.3 million . This disclosure change had no effect on the consolidated statements of operations and cash flows for the six months ended December 31, 2018. Leases On July 1, 2019, the Company adopted Topic 842, Leases, using the modified retrospective method. Results for reporting periods beginning after July 1, 2019 were presented under Topic 842, while prior period amounts were not adjusted and continue to be reported in accordance with the historical accounts under Topic 840. The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use ("ROU") assets, current operating lease liabilities and long-term operating lease liabilities on the Company's condensed consolidated balance sheets. Finance leases are included in property, plant and equipment, finance lease liabilities and long-term finance leases liabilities on the condensed consolidated balance sheets. The Company elected the practical expedient permitted under the transition guidance, which allowed the Company to carryforward its historical lease classification, the Company's assessment on whether a contract was or contains a lease, and its initial direct costs for any leases that existed prior to July 1, 2019. The Company elected to combine its lease and non-lease components as a single lease component for all asset classes. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company uses an estimate of its incremental borrowing rate based on the information available at the lease commencement date. The operating lease ROU assets also include any lease payments made and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease expense is generally recognized on a straight-line basis over the lease term. Variable lease payments are expensed as incurred and are not included within the operating lease ROU asset and lease liability calculation. The Company does not record leases on the condensed consolidated balance sheet with a term of one year or less. See Note 6 for further details. Joint Venture In March 2016, the Company executed an agreement with two strategic investment funds owned by the Municipality of Chongqing, China (the "Chongqing Funds") to form a joint venture, (the "JV Company"), for a new state-of-the-art power semiconductor packaging, testing and wafer fabrication facility in Liangjiang New Area of Chongqing (the "Joint Venture"). As of December 31, 2019 , the Company owns 51% , and the Chongqing Funds own 49% of the equity interest in the JV Company. The Joint Venture is accounted for under the provisions of the consolidation guidance since the Company has a controlling financial interest. The JV Company has continued ramping up its production of assembly and testing during the six months ended December 31, 2019. In July 2019, we commenced limited mass production at the 12-inch wafer fabrication facility, and continued ramping up during the six months ended December 31, 2019. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, leases, share-based compensation, and useful lives for property, plant and equipment and intangible assets. Share-based Compensation Expense The Company recognizes expense related to share-based compensation awards that are ultimately expected to vest based on estimated fair values on the date of grant. The fair value of restricted share units is based on the market value of the Company's common share on the date of grant. For restricted stock awards subject to market conditions, the fair value of each restricted stock award is estimated at the date of grant using the Monte-Carlo pricing model. The fair value of stock options is estimated on the date of grant using the Black-Scholes option valuation model. Share-based compensation expense is recognized on the accelerated attribution basis, net of estimated forfeitures, over the requisite service period of the award, which generally equals the vesting period. Restricted Cash As a condition of the loan agreement, the Company is required to keep a compensating balance at the issuing bank (see Note 5). In addition, the Company also maintained restricted cash in connection with cash balances temporarily restricted for regular business operations including a dispute case with a vendor. These balances have been excluded from the Company’s cash and cash equivalents balance and are classified as restricted cash in the Company’s consolidated balance sheets. As of December 31, 2019 and June 30, 2019, the amount of restricted cash was $4.2 million and $2.4 million , respectively. Fair Value of Financial Instruments The fair value of cash equivalents is based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities. The carrying value of the company's debt is considered a reasonable estimate of fair value which is estimated by considering the current rates available to the Company for debt of the same remaining maturities, structure and terms of the debts. Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss). Recent Accounting Pronouncements Recently Issued Accounting Standards not yet adopted In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12") by removing certain exceptions to the general principles. The amendments will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of the amendments is permitted. Depending on the amendment, adoption may be applied on a retrospective, modified retrospective or prospective basis. We are currently evaluating the impacts of adoption of the new guidance to our consolidated financial statements. In August 2018, the FASB issued ASU 2018-15 “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract". These amendments align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contact with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by these amendments. ASU 2018-15 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2019. Early adoption is permitted. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13”). ASU 2018-13 amends existing fair value measurement disclosure requirements by adding, changing, or removing certain disclosures. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. ASU No. 2018-13 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2019. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses ("ASU 2016-13"). This accounting standard update changes the accounting for recognizing impairments of financial assets. Under the update, credit losses for certain types of financial instruments will be estimated based on expected losses. The update also modifies the impairment models for available-for-sale debt securities and for purchased financial assets with credit deterioration since their origination. This update is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company is currently evaluating the impact of this accounting standard update on its Consolidated Financial Statements. Recently Adopted Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This guidance requires a dual approach for lessee accounting under which a lessee accounts for leases as finance leases or operating leases. Both finance and operating leases result in the lessee recognizing a right-of-use asset and a corresponding liability on its balance sheet, with differing methodology for income statement recognition. The Company adopted this standard as of July 1, 2019, using the modified retrospective transition method and recorded a cumulative-effect balance sheet adjustment. As a result of adopting ASU 2016-02 on July 1, 2019, the Company recognized operating lease right-of-use assets and corresponding operating lease liabilities of approximately $21 million each from existing leases on the Company's condensed consolidated balance sheet. See Note 6 for further details. In June 2018, the FASB issued ASU 2018-07, "Compensation -Stock Compensation: Improvement to Nonemployees Share-Based Payment Accounting ("ASU 2018-07"), which expands the scope of Topic 718 to include all share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 specifies that Topic 718 applies to all share-based payment transactions in which the grantor acquires goods and services to be used or consumed in its own operations by issuing share-based payment awards. ASU 2018-07 also clarifies that Topic 718 does not apply to share-based payments used to effectively provide (1) financing to the issuer or (2) awards granted in conjunction with selling goods or services to customers as part of a contract accounted for under ASC 606. ASU 2018-07 had no material impact on the Company's consolidated financial statements.

Net Income Per Common Share Att

Net Income Per Common Share Attributable to Alpha and Omega Semiconductor Limited	6 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Common Share Attributable to Alpha and Omega Semiconductor Limited The following table presents the calculation of basic and diluted net income (loss) per share attributable to common shareholders: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands, except per share data) Numerator: Net income (loss) attributable to Alpha and Omega Semiconductor Limited $ (1,005 ) $ (1,545 ) $ 4 $ 871 Denominator: Basic: Weighted average number of common shares used to compute basic net income per share 24,701 23,887 24,620 23,865 Diluted: Weighted average number of common shares used to compute basic net income per share 24,701 23,887 24,620 23,865 Effect of potentially dilutive securities: Stock options, RSUs and ESPP shares — — 742 648 Weighted average number of common shares used to compute diluted net income per share 24,701 23,887 25,362 24,513 Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited: Basic $ (0.04 ) $ (0.06 ) $ 0.00 $ 0.04 Diluted $ (0.04 ) $ (0.06 ) $ 0.00 $ 0.04 The following potential dilutive securities were excluded from the computation of diluted net income per share as their effect would have been anti-dilutive: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Employee stock options and RSUs 2,040 2,225 337 646 ESPP 868 1,240 597 508 Total potential dilutive securities 2,908 3,465 934 1,154

Concentration of Credit Risk an

Concentration of Credit Risk and Significant Customers	6 Months Ended
	Dec. 31, 2019
Risks and Uncertainties [Abstract]
Concentration of Credit Risk and Significant Customers	Concentration of Credit Risk and Significant Customers The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application and review of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers. Credit sales, which are mainly on credit terms of 30 to 60 days , are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its trade accounts receivable to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available. The Company ships its product indirectly to Huawei and its affiliates (collectively, “Huawei”) through distributors. Typically, the Company sells its products to distributors who then sell to original design manufacturers (“ODM’s”) that incorporate our products into end applications that are then shipped to Huawei. While distributor point of sale reports summarize distributor sales to ODM’s, the Company must make certain assumptions and estimates in order to determine the amount of revenues attributed to indirect shipment to Huawei. During the fiscal year ended June 30, 2019, the estimated revenues attributed to indirect shipment to Huawei were approximately 2% of total revenues. During the period from May 2019 to December 2019, estimated revenues earned by the Company from shipments indirectly made to Huawei were in the range of $11 million to $13 million . See Note 10. Summarized below are individual customers whose revenue or accounts receivable balances were more than 10% of the respective total consolidated amounts: Three Months Ended December 31, Six Months Ended December 31, Percentage of revenue 2019 2018 2019 2018 Customer A 31.3 % 30.6 % 30.0 % 29.1 % Customer B 37.0 % 37.6 % 36.0 % 37.8 % December 31, June 30, Percentage of accounts receivable Customer A 14.0 % 12.1 % Customer B 39.9 % 19.7 % Customer C * 18.1 % Customer D * 13.3 % * Less than 10%

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Accounts receivable, net: December 31, June 30, (in thousands) Accounts receivable $ 58,859 $ 48,401 Less: Allowance for price adjustments (24,957 ) (24,075 ) Less: Allowance for doubtful accounts (30 ) (30 ) Accounts receivable, net $ 33,872 $ 24,296 Inventories: December 31, June 30, (in thousands) Raw materials $ 58,454 $ 59,076 Work in-process 47,818 38,214 Finished goods 11,319 14,353 $ 117,591 $ 111,643 Other current assets: December 31, June 30, (in thousands) VAT receivable $ 28,125 $ 30,769 Other prepaid expenses 1,884 2,745 Prepaid insurance 1,238 939 Prepaid maintenance 858 481 Prepayment to supplier 1,048 583 Prepaid income tax 285 267 Customs deposit 195 114 Lease financing cost — 825 Interest receivable 679 379 Other receivable 83 — $ 34,395 $ 37,102 Property, plant and equipment, net: December 31, June 30, (in thousands) Land $ 4,877 $ 4,877 Building 59,329 36,205 Manufacturing machinery and facility equipment 434,089 303,750 Equipment and tooling 23,200 20,739 Computer equipment and software 38,413 34,048 Office furniture and equipment 3,378 3,243 Leasehold improvements 67,972 53,597 Land use rights 8,602 8,760 639,860 465,219 Less: accumulated depreciation (271,170 ) (252,982 ) 368,690 212,237 Equipment and construction in progress 47,365 197,500 Property, plant and equipment, net $ 416,055 $ 409,737 Intangible assets, net: December 31, June 30, (in thousands) Patents and technology rights $ 18,037 $ 18,037 Trade name 268 268 Customer relationships 1,150 1,150 19,455 19,455 Less: accumulated amortization (2,898 ) (2,842 ) 16,557 16,613 Goodwill 269 269 Intangible assets, net $ 16,826 $ 16,882 Intangible assets of patents and technology rights are primarily related to a license agreement that the Company entered into with STMicroelectronics International N.V. (“STMicro”) on September 5, 2017, pursuant to which STMicro granted the Company a world-wide, royalty-free and fully-paid license to use its technologies to develop, market and distribute certain digital multi-phase controller products. This agreement allows the Company to develop and market digital power products, primarily in the computer server segment. As of December 31, 2019 , the Company recorded $16.2 million of intangible assets related to STMicro. The Company begins amortizing such license fees when the technology has met the Company's qualification and is ready for its intended use in production. Other long-term assets: December 31, June 30, (in thousands) Prepayments for property and equipment $ 4,043 $ 4,846 Investment in a privately held company 700 700 Lease financing costs — 1,758 Customs deposit 1,875 980 Other long-term deposits 1,595 889 Office leases deposits 1,044 1,031 Other 245 413 $ 9,502 $ 10,617 Accrued liabilities: December 31, June 30, (in thousands) Accrued compensation and benefits $ 19,284 $ 16,385 Warranty accrual 651 623 Stock rotation accrual 3,836 1,921 Accrued professional fees 2,496 1,721 Accrued inventory 668 857 Accrued facilities related expenses 2,218 4,233 Accrued financing lease costs 715 728 Accrued property, plant and equipment 11,806 11,527 ESPP payable 623 585 Customer deposit 2,318 351 Other accrued expenses 8,079 5,144 $ 52,694 $ 44,075 The activities in the warranty accrual, included in accrued liabilities, are as follows: Six Months Ended December 31, 2019 2018 (in thousands) Beginning balance $ 623 $ 535 Additions 130 189 Utilization (102 ) (69 ) Ending balance $ 651 $ 655 The activities in the stock rotation accrual, included in accrued liabilities, are as follows: Six Months Ended December 31, 2019 2018 (in thousands) Beginning balance $ 1,921 $ 1,750 Additions 5,990 2,229 Utilization (4,075 ) (2,132 ) Ending balance $ 3,836 $ 1,847 Other long-term liabilities: December 31, June 30, (in thousands) Customer deposits $ 8,000 * $ 10,000 * Computer software liabilities 2,810 3,701 Other — 220 Other long-term liabilities $ 10,810 $ 13,921 * Customer deposits are from Customer A and Customer B for securing future product shipments from the Company. The Company reclassified $2.0 million of the customer deposit to short term accrued liabilities during the six months ended December 31, 2019 since the repayment of this amount is due within a year.

Bank Borrowing Bank Borrowing

Bank Borrowing Bank Borrowing	6 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Bank Borrowing	Bank Borrowings Short-term borrowings In October 2019, the Company's subsidiary in China entered into a line of credit facility with Bank of Communications Limited in China. This line of credit matures on February 14, 2021 and is based on the China Base Rate multiplied by 1.05 , or 4.99% on October 31, 2019. The purpose of the credit facility was to provide short-term borrowings. The Company could borrow up to approximately RMB 60.0 million or $8.5 million based on the currency exchange rate between the RMB and the U.S. Dollar on October 31, 2019. As of December 31, 2019 , there was no outstanding balance under the loan. On September 23, 2019, the JV Company entered into a short term revolving loan agreement with China Everbright bank in China. The JV Company can borrow up to Chinese Renminbi (RMB) 50.0 million , or $7.1 million based on the currency exchange rate between RMB and U.S. Dollar on September 23, 2019, at varying interest rates, with either RMB or USD. Interest payments with the entire principal are due no later than 90 days from each borrowing date. As of December 31, 2019 , the outstanding balance under the loan was $6.3 million . On March 21, 2019, the JV Company entered into a one-year loan agreement with China Everbright Bank in China to provide a loan for RMB 20 million , or $3.0 million based on the currency exchange rate between RMB and U.S. Dollar on March 31, 2019 at a fixed interest rate of 5.44% per annum. Interest payments are due monthly with the entire principal due on March 21, 2020. As of December 31, 2019 , the outstanding balance under the loan was 20 million RMB (equivalent of $2.9 million based on the currency exchange rate as of December 31, 2019 ). On November 29 and December 4, 2018, the JV Company entered into two one-year loan agreements with China Merchant Bank and Chongqing LiangJiang New District China Merchants Group Limited Company in China to provide loans for RMB 80 million and 20 million , respectively, or $14.5 million in total based on the currency exchange rate between RMB and U.S. Dollar on December 31, 2018, at varying interest rates. In December 2019, the JV Company repaid these borrowings on their maturity dates. On January 20, 2020, the JV Company renewed the loan agreements. Interest payments are due monthly and quarterly with the entire principal due not later than January 21, 2021. As of December 31, 2019 , there were no outstanding balances under the loans. On November 16, 2018, the Company's subsidiary in China entered into a line of credit facility with Industrial and Commercial Bank of China, which expired on September 30, 2019. The purpose of the credit facility was to provide short-term borrowings. The Company could borrow up to approximately RMB 72.0 million or $10.3 million based on currency exchange rate between RMB and U.S. Dollar on November 16, 2018. In October 2019, this line of credit was renewed with a maturity date of September 30, 2020. As of December 31, 2019 , there was no outstanding balance under the line of credit. Accounts Receivable Factoring Agreement On August 9, 2019, one of the Company's wholly-owned subsidiaries ("the "Borrower") entered into a factoring agreement with the Hongkong and Shanghai Banking Corporation Limited (“HSBC”), whereby the Borrower assigns certain of its accounts receivable with recourse. This factoring agreement allows the Borrower to borrow up to 70% of the net amount of its eligible accounts receivable of the Borrower with a maximum amount of $30.0 million . The interest rate is based on one month LIBOR plus 1.75% per annum. This agreement, with certain financial covenants required, has no expiration date. The Company is the guarantor for this agreement. The Company is accounting for this transaction as a secured borrowing under the Transfers and Servicing of Financial Assets guidance. In addition, any cash held in the restricted bank account controlled by HSBC has a legal right of offset against the borrowing. The Borrower was in compliance with these covenants as of December 31, 2019 . In December 2019, $2.0 million of borrowing in August was repaid. As of December 31, 2019 , there was no outstanding balance and the Company had unused credit of approximately $30.0 million . Credit Facilities On May 9, 2018 (the “Effective Date”), the JV Company entered into a lease finance agreement and a security agreement (the “Agreements”) with YinHai Leasing Company and China Import/Export Bank (the “Lenders”). Pursuant to the Agreements, the Lenders agree to provide an aggregate of RMB 400.0 million , or $62.8 million based on the currency exchange rate between RMB and U.S. Dollar on the Effective Date, of financing to the JV Company (the “Lease Financing”). In exchange for the Lease Financing, the JV Company agrees to transfer title of its assembly and testing equipment to the Lenders, and the Lenders lease such equipment to the JV Company under a five -year lease arrangement, pursuant to which the JV Company makes quarterly lease payments to the Lenders consisting of principal and interest based on a repayment schedule mutually agreed by the parties. The interest under the Lease Financing is accrued based on the China Base Rate multiplied by 1.15 , or 5.4625% on the Effective Date. Under the Agreements, at the end of the five-year lease term, the Lenders agree to sell such equipment back to the JV Company for a nominal amount (RMB 1 ). The JV Company’s obligations under the Lease Financing are secured by the land and building owned by the JV Company (the “Collateral”). The proceeds from the Lease Financing will be used primarily for the acquisition and installation of the 12-inch fabrication equipment and other expenses of the JV Company relating to the completion of the fabrication facility located in Chongqing. The Agreements contain customary representation, warranties and covenants, including restrictions on the transfer of the Collateral. The Agreements also contain customary events of default, including but not limited to, failure to make payments and breach of material terms under the Agreements. The Agreements include certain customary closing conditions, including the payment of deposit by the JV Company. As of December 31, 2019 , the outstanding balance under the Agreement was 352.0 million RMB (equivalent of $50.3 million based on the currency exchange rate as of December 31, 2019 ), which was recorded under short-term and long-term finance lease liabilities. See future minimum lease payments table for finance lease liabilities in Note 6. Long-term debt In December 2019, the JV Company entered into a loan agreement with China Development Bank in the amount of $24.0 million . The obligation under the loan agreement is secured by certain assets of the JV Company. Beginning December 18, 2020, the JV Company will make consecutive semi-annual payments of principal until December 8, 2024. The interest is accrued based on the LIBOR rate plus 280BP . The interest is required to be paid on March 21 and September 21 each year. As of December 31, 2019, the outstanding balance of the loan was $24.0 million . On March 12, 2019, the JV Company entered into a loan agreement with The Export-Import Bank of China in the aggregate principal amount of 200 million RMB (approximately $29.8 million based on currency exchange rate between RMB and U.S. Dollar on March 31, 2019). The loan will mature on February 20, 2025. The JV Company drew down 190 million RMB and 10 million RMB in March 2019 and December 2019, respectively. The loan withdraw window will expire on February 28, 2020. The interest is accrued based on the China Base Rate multiplied by 1.1 , or 5.39% . The loan requires quarterly interest payments. The principal payments are required to be paid every 6 months over the term of loan commencing in October 2019. This loan is secured by the buildings and certain equipment owned by the JV Company. As a condition of the loan arrangements, 14 million RMB (approximately $2.0 million ) of cash is held as restricted cash by the JV Company as a compensating balance at the JV Company's bank until the principal is paid. In December 2019, 3.0 million RMB was repaid. As of December 31, 2019 , the outstanding balance of the loan was 197 million RMB (equivalent of $28.2 million based on the currency exchange rate as of December 31, 2019 ). On May 1, 2018, Jireh Semiconductor Incorporated ("Jireh"), a wholly-owned subsidiary of the Company, entered into a loan agreement with a financial institution (the "Bank") that provided a term loan in the amount of $17.8 million . The obligation under the loan agreement is secured by certain real estate assets of Jireh and guaranteed by the Company. The loan has a five-year term and matures on June 1, 2023. Beginning June 1, 2018, Jireh made consecutive monthly payments of principal and interest to the Bank. The outstanding principal shall accrue interest at a fixed rate of 5.04% per annum on the basis of a 360-day year. The loan agreement contains customary restrictive covenants and includes certain financial covenants that require the Company to maintain, on a consolidated basis, specified financial ratios. The Company was in compliance with these covenants as of December 31, 2019 . As of December 31, 2019 , the outstanding balance of the term loan was $16.4 million . On August 15, 2017, Jireh entered into a credit agreement with the Bank that provided a term loan in an amount up to $30.0 million for the purpose of purchasing certain equipment for the Company's fabrication facility located in Oregon. The obligation under the credit agreement is secured by substantially all assets of Jireh and guaranteed by the Company. The credit agreement has a five -year term and matures on August 15, 2022. In January 2018 and July 2018, Jireh drew down the loan in the amount of $13.2 million and $16.7 million , respectively. Beginning in October 2018, Jireh was required to pay to the Bank on each payment date, the outstanding principal amount of the loan in monthly installments. The loan accrues interest based on an adjusted London Interbank Offered Rate ("LIBOR") as defined in the credit agreement, plus a specified applicable margin in the range of 1.75% to 2.25% , based on the outstanding balance of the loan. The credit agreement contains customary restrictive covenants and includes certain financial covenants that require the Company to maintain, on a consolidated basis, specified financial ratios and fixed charge coverage ratio. The Company was in compliance with these covenants as of December 31, 2019 . As of December 31, 2019 , the outstanding balances of the term loan were $20.5 million . Maturities of short-term debt and long-term debt were as follows (in thousands): Year ending June 30, 2020 (Remaining) $ 13,738 2021 14,569 2022 20,115 2023 28,604 2024 12,175 Thereafter 8,975 Total principal of debts 98,176 Less: debt issuance costs (838 ) Total principal of debt, less debt issuance costs $ 97,338 Short-term Debt Long-term Debt Principal amount $ 21,212 $ 76,964 Less: debt issuance costs (183 ) (655 ) Total debt, less debt issuance costs $ 21,029 $ 76,309

Leases

Leases	6 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Leases Under Topic 842, the Company evaluates contracts for lease accounting at contract inception and assesses lease classification at the lease commencement date. Operating leases are included in operating lease right-of-use ("ROU") assets, operating lease liabilities and operating lease liabilities - long-term on the Company's consolidated balance sheets. Finance leases are included in property, plant and equipment, finance lease liabilities and finance lease liabilities-long-term on the consolidated balance sheets. The Company recognizes an ROU asset and corresponding lease obligation liability at the lease commencement date where the lease obligation liability is measured at the present value of the minimum lease payments. As most of the leases do not provide an implicit rate, the Company uses its incremental borrowing rate at lease commencement. The Company uses an interest rate commensurate with the interest rate to borrow on a collateralized basis over a similar term with an amount equal to the lease payments. Operating leases are primarily related to offices, research and development facilities, sales and marketing facilities, and manufacturing facilities. In addition, long-term supply agreements to lease gas tank equipment and purchase industrial gases are accounted for as operating leases. Lease agreements frequently include renewal provisions and require the Company to pay real estate taxes, insurance and maintenance costs. For operating leases, the amortization of the ROU asset and the accretion of its lease obligation liability result in a single straight-line expense recognized over the lease term. The finance lease is related to the RMB 400.0 million of lease financing with YinHai Leasing Company and China Import/Export Bank in the JV Company. See Note 5 - Bank Borrowings for details. The Company does not record leases on the condensed consolidated balance sheet with a term of one year or less. The components of the Company’s operating and finance lease expenses are as follows for the period presented (in thousands): Six Months Ended December 31, 2019 Operating Leases: Fixed rent expense $ 2,614 Variable rent expense 421 Finance Lease: Amortization of equipment 1,716 Interest 1,457 Short-term leases Short-term lease expenses 152 Total lease expenses $ 6,360 Supplemental balance sheet information related to the Company’s operating and finance leases is as follows (in thousands, except lease term and discount rate): December 31, 2019 Operating Leases : ROU assets associated with operating leases $ 18,667 Finance Lease: Property, plant and equipment, gross 105,606 Accumulated depreciation (86,806 ) Property, plant and equipment, net 18,800 Weighted average remaining lease term (in years) Operating leases 9.73 Finance lease 3.22 Weighted average discount rate Operating leases 5.29 % Finance lease 5.46 % Supplemental cash flow information related to the Company’s operating and finance lease is as follows (in thousands): Six Months Ended December 31, 2019 Cash paid from amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,541 Operating cash flows from finance lease $ 1,457 Financing cash flows from finance lease $ 3,403 Future minimum lease payments are as follows as of December 31, 2019 (in thousands): Operating Leases Finance Leases The remainder of 2020 $ 2,417 $ 9,062 2021 3,248 17,477 2022 2,716 16,622 2023 2,360 12,048 2024 1,973 — 2025 1,466 — Thereafter 10,128 — Total minimum lease payments 24,308 55,209 Less amount representing interest (5,467 ) (4,893 ) Total lease liabilities $ 18,841 $ 50,316 Prior to the adoption of the new lease standard, future minimum lease payments as of June 30, 2019 were as follows (in thousands): Year ending June 30, Operating Leases Finance Leases 2020 $ 4,357 $ 14,219 2021 1,741 17,799 2022 1,164 16,928 2023 894 12,269 2024 1,002 — Thereafter 149 — Total minimum lease payments 9,307 61,215 Less amount representing interest — (6,479 ) Total lease liabilities $ 9,307 $ 54,736
Leases	Leases Under Topic 842, the Company evaluates contracts for lease accounting at contract inception and assesses lease classification at the lease commencement date. Operating leases are included in operating lease right-of-use ("ROU") assets, operating lease liabilities and operating lease liabilities - long-term on the Company's consolidated balance sheets. Finance leases are included in property, plant and equipment, finance lease liabilities and finance lease liabilities-long-term on the consolidated balance sheets. The Company recognizes an ROU asset and corresponding lease obligation liability at the lease commencement date where the lease obligation liability is measured at the present value of the minimum lease payments. As most of the leases do not provide an implicit rate, the Company uses its incremental borrowing rate at lease commencement. The Company uses an interest rate commensurate with the interest rate to borrow on a collateralized basis over a similar term with an amount equal to the lease payments. Operating leases are primarily related to offices, research and development facilities, sales and marketing facilities, and manufacturing facilities. In addition, long-term supply agreements to lease gas tank equipment and purchase industrial gases are accounted for as operating leases. Lease agreements frequently include renewal provisions and require the Company to pay real estate taxes, insurance and maintenance costs. For operating leases, the amortization of the ROU asset and the accretion of its lease obligation liability result in a single straight-line expense recognized over the lease term. The finance lease is related to the RMB 400.0 million of lease financing with YinHai Leasing Company and China Import/Export Bank in the JV Company. See Note 5 - Bank Borrowings for details. The Company does not record leases on the condensed consolidated balance sheet with a term of one year or less. The components of the Company’s operating and finance lease expenses are as follows for the period presented (in thousands): Six Months Ended December 31, 2019 Operating Leases: Fixed rent expense $ 2,614 Variable rent expense 421 Finance Lease: Amortization of equipment 1,716 Interest 1,457 Short-term leases Short-term lease expenses 152 Total lease expenses $ 6,360 Supplemental balance sheet information related to the Company’s operating and finance leases is as follows (in thousands, except lease term and discount rate): December 31, 2019 Operating Leases : ROU assets associated with operating leases $ 18,667 Finance Lease: Property, plant and equipment, gross 105,606 Accumulated depreciation (86,806 ) Property, plant and equipment, net 18,800 Weighted average remaining lease term (in years) Operating leases 9.73 Finance lease 3.22 Weighted average discount rate Operating leases 5.29 % Finance lease 5.46 % Supplemental cash flow information related to the Company’s operating and finance lease is as follows (in thousands): Six Months Ended December 31, 2019 Cash paid from amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,541 Operating cash flows from finance lease $ 1,457 Financing cash flows from finance lease $ 3,403 Future minimum lease payments are as follows as of December 31, 2019 (in thousands): Operating Leases Finance Leases The remainder of 2020 $ 2,417 $ 9,062 2021 3,248 17,477 2022 2,716 16,622 2023 2,360 12,048 2024 1,973 — 2025 1,466 — Thereafter 10,128 — Total minimum lease payments 24,308 55,209 Less amount representing interest (5,467 ) (4,893 ) Total lease liabilities $ 18,841 $ 50,316 Prior to the adoption of the new lease standard, future minimum lease payments as of June 30, 2019 were as follows (in thousands): Year ending June 30, Operating Leases Finance Leases 2020 $ 4,357 $ 14,219 2021 1,741 17,799 2022 1,164 16,928 2023 894 12,269 2024 1,002 — Thereafter 149 — Total minimum lease payments 9,307 61,215 Less amount representing interest — (6,479 ) Total lease liabilities $ 9,307 $ 54,736

Shareholders' Equity and Share-

Shareholders' Equity and Share-based Compensation	6 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Shareholders' Equity and Share-based Compensation	Shareholders' Equity and Share-based Compensation Share Repurchase In September 2017, the Board of Directors approved a new repurchase program (the “Repurchase Program”) that allowed the Company to repurchase its common shares from the open market pursuant to a pre-established Rule 10b5-1 trading plan or through privately negotiated transactions up to an aggregate of $30.0 million . The amount and timing of any repurchases under the Repurchase Program depend on a number of factors, including but not limited to, the trading price, volume, and availability of the Company's common shares. Shares repurchased under this program are accounted for as treasury shares and the total cost of shares repurchased is recorded as a reduction of shareholders' equity. From time to time, treasury shares may be reissued as part of the Company's stock-based compensation programs. Gains on re-issuance of treasury stock are credited to additional paid-in capital; losses are charged to additional paid-in capital to offset the net gains, if any, from previous sales or re-issuance of treasury stock. Any remaining balance of the losses is charged to retained earnings. During the six months ended December 31, 2019 , the Company did not repurchase any shares from the open market. Since the inception of the program, the Company repurchased an aggregate of 6,784,648 shares from the open market for a total cost of $67.3 million , at an average price of $9.92 per share, excluding fees and related expenses. No repurchased shares have been retired. Of the 6,784,648 repurchased shares, 140,328 shares with a weighted average repurchase price of $10.39 per share, were reissued at an average price of $5.50 per share pursuant to option exercises and vested restricted share units. As of December 31, 2019 , approximately $13.4 million remained available under the Repurchase Program. Time-based Restricted Stock Units ("TRSU") The following table summarizes the Company's TRSU activities for the six months ended December 31, 2019 : Number of Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested at June 30, 2019 906,341 $ 14.09 1.62 $ 8,465,225 Granted 64,442 $ 12.24 Vested (73,312 ) $ 13.71 Forfeited (14,125 ) $ 14.12 Nonvested at December 31, 2019 883,346 $ 13.98 1.22 $ 12,031,173 Market-based Restricted Stock Units ("MSUs") During the quarter ended September 30, 2018, the Company granted 1.3 million market-based restricted stock units ("MSUs") to certain personnel. The number of shares to be earned at the end of performance period is determined based on the Company’s achievement of specified stock prices and revenue thresholds during the performance period from January 1, 2019 to December 31, 2021 as well as the recipients remaining in continuous service with the Company through such period. The MSUs vest in four equal annual installments after the end of each performance period. The Company estimated the grant date fair values of its MSUs with derived service periods of 4.5 to 7.5 years using a Monte-Carlo simulation model with the following assumptions: Risk-free interest rate of 2.7% , expected term of 3.5 years, expected volatility of 38.8% and dividend yield of 0% . The Company recorded approximately $0.1 million and $0.3 million of expenses for these MSUs during the three and six months ended December 31, 2019 , respectively, and approximately $0.2 million and $0.4 million during the three and six months ended December 31, 2018 , respectively. Performance-based Restricted Stock Units ("PRSUs") In March 2017, 2018 and 2019, the Company granted 170,000 , 298,050 and 291,750 performance-based RSUs (“PRSUs”), respectively to certain personnel. The number of shares to be earned under the PRSUs is determined based on the level of attainment of predetermined financial goals. The PRSUs vest in four equal annual installments from the first anniversary date after the grant date if certain predetermined financial goals were met. The Company recorded approximately $0.5 million and $0.7 million of expenses for these PRSUs during the three and six months ended December 31, 2019 , respectively, and approximately $0.8 million and $1.4 million during the three and six months ended December 31, 2018 , respectively. The following table summarizes the Company's PRSUs activities for the six months ended December 31, 2019 : Number of Performance-based Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested at June 30, 2019 596,724 $ 13.95 1.88 $ 5,573,402 Forfeited (3,625 ) $ 15.11 Nonvested at December 31, 2019 593,099 $ 13.94 1.37 $ 8,078,008 Stock Options The Company did not grant any stock options during the three and six months ended December 31, 2019 and 2018. The number of options expected to vest is the result of applying the pre-vesting forfeiture rate assumption to total outstanding options. The following table summarizes the Company's stock option activities for the six months ended December 31, 2019 : Weighted Weighted Average Average Remaining Number of Exercise Price Contractual Aggregate Shares Per Share Term (in years) Intrinsic Value Outstanding at June 30, 2019 876,478 $ 10.98 3.06 $ 758,871 Exercised (2,500 ) $ 10.50 $ 4,726 Canceled or forfeited (5,000 ) $ 15.00 Outstanding at December 31, 2019 868,978 $ 10.96 2.58 $ 3,108,361 Options vested and expected to vest 868,978 $ 10.96 2.58 $ 3,108,361 Exercisable at December 31, 2019 868,978 $ 10.96 2.58 $ 3,108,361 Employee Share Purchase Plan ("ESPP") The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows: Six Months Ended December 31, 2019 Volatility rate 46.4% Risk-free interest rate 1.6% Expected term 1.3 years Dividend yield 0% Share-based Compensation Expense T he total share-based compensation expense recognized in the condensed consolidated statements of operations for the periods presented was as follows: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Cost of goods sold $ 404 $ 541 $ 840 $ 1,038 Research and development 472 742 996 1,374 Selling, general and administrative 1,611 3,135 3,020 5,135 $ 2,487 $ 4,418 $ 4,856 $ 7,547 As of December 31, 2019 , total unrecognized compensation cost under the Company's equity plans was $9.3 million , which is expected to be recognized over a weighted-average period of 1.9 years.

Income Taxes

Income Taxes	6 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recognized income tax expense of approximately $0.6 million and $0.7 million , for the three months ended December 31, 2019 and 2018, respectively. Excluding the discrete income tax items, the effective tax rate for the three months ended December 31, 2019 and 2018 was (13.8)% . The changes in the tax expense between the periods resulted primarily from changes in the mix of earnings in various geographic jurisdictions between the current year and the same period of last year. For the six months ended December 31, 2019, the Company recognized income tax expense of approximately $1.0 million , which included a discrete tax expense of $0.03 million . For the six months ended December 31, 2018, the Company recognized income tax expense of approximately $1.3 million , which included a discrete tax expense of $0.03 million . Excluding the discrete income tax items, the estimated effective tax rate for the six months ended December 31, 2019 was (17.4)% compared to (23.7)% for the six months ended December 31, 2018. The changes in the effective tax rate and tax expense between the periods resulted primarily from changes in the mix of earnings in various geographic jurisdictions between the current year and the same period of last year. The Company files its income tax returns in the United States and in various foreign jurisdictions. The tax years 2001 to 2019 remain open to examination by U.S. federal and state tax authorities. The tax years 2012 to 2019 remain open to examination by foreign tax authorities. The Company's income tax returns are subject to examinations by the Internal Revenue Service and other tax authorities in various jurisdictions. In accordance with the guidance on the accounting for uncertainty in income taxes, the Company regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of its provision for income taxes. These assessments can require considerable estimates and judgments. As of December 31, 2019 , the gross amount of unrecognized tax benefits was approximately $7.3 million , of which $4.3 million , if recognized, would reduce the effective income tax rate in future periods. If the Company's estimate of income tax liabilities proves to be less than the ultimate assessment, then a further charge to expense would be required. If events occur and the payment of these amounts ultimately proves to be unnecessary, the reversal of the liabilities would result in tax benefits being recognized in the period when the Company determines the liabilities are no longer necessary. The Company does not anticipate any material changes to its uncertain tax positions during the next twelve months. On July 27, 2015, in Altera Corp. v. Commissioner, the U.S. Tax Court issued an opinion related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. In the July 2015 ruling, the Tax Court concluded that the sharing of the cost of employee stock compensation in a company’s cost-sharing arrangement was invalid under the U.S. Administrative Procedures Act. In June 2019, a panel of the Ninth Circuit of the U.S. Court of Appeals reversed this decision. In July 2019, Altera petitioned U.S. Court of Appeals for the Ninth Circuit to hold an en banc rehearing of the case. Due to the uncertainty surrounding the status of the current regulations and questions related to the scope of potential benefits, the Company has not recorded any benefit as of December 31, 2019. The Company will continue to monitor ongoing developments and potential impacts to its financial statements.

Segment and Geographic Informat

Segment and Geographic Information	6 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment and Geographic Information	Segment and Geographic Information The Company is organized as, and operates in, one operating segment: the design, development and supply of power semiconductor products for computing, consumer electronics, communication and industrial applications. The chief operating decision-maker is the Chief Executive Officer. The financial information presented to the Company's Chief Executive Officer is on a consolidated basis, accompanied by information about revenue by customer and geographic region, for purposes of evaluating financial performance and allocating resources. The Company has one business segment, and there are no segment managers who are held accountable for operations, operating results and plans for products or components below the consolidated unit level. Accordingly, the Company reports as a single operating segment. The Company sells its products primarily to distributors in the Asia Pacific region, who in turn sell these products to end customers. Because the Company's distributors sell their products to end customers which may have a global presence, revenue by geographical location is not necessarily representative of the geographical distribution of sales to end user markets. The revenue by geographical location in the following tables is based on the country or region in which the products were shipped to: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Hong Kong $ 97,244 $ 87,180 $ 190,346 $ 178,771 China 16,571 24,760 33,083 45,157 South Korea 2,279 139 8,269 308 United States 898 1,967 1,999 3,940 Other countries 868 879 1,965 1,821 $ 117,860 $ 114,925 $ 235,662 $ 229,997 The following is a summary of revenue by product type: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Power discrete $ 101,491 $ 93,294 $ 202,032 $ 185,549 Power IC 14,655 19,384 30,379 38,799 Packaging and testing services 1,714 2,247 3,251 5,649 $ 117,860 $ 114,925 $ 235,662 $ 229,997 Long-lived assets, net consisting of property, plant and equipment and land use rights, by geographical area are as follows: December 31, June 30, (in thousands) China $ 321,256 $ 321,145 United States 93,976 87,817 Other Countries 823 775 $ 416,055 $ 409,737

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Commitments As of December 31, 2019 and June 30, 2019 , the Company had approximately $52.0 million and $59.5 million , respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services, and approximately $24.3 million and $33.8 million , respectively, of capital commitments for the purchase of property and equipment and EPC construction. Other Commitments See Note 5 and Note 6 of the Notes to the Condensed Consolidated Financial Statements contained in this Quarterly Report on Form 10-Q for descriptions of commitments including bank borrowings and leases . Contingencies and Indemnities The Company has in the past, and may from time to time in the future, become involved in legal proceedings arising from the normal course of business activities. The semiconductor industry is characterized by frequent claims and litigation, including claims regarding patent and other intellectual property rights as well as improper hiring practices. Irrespective of the validity of such claims, the Company could incur significant costs in the defense of such claims and suffer adverse effects on its operations. The U.S. Department of Justice recently commenced an investigation into the Company's compliance with export control regulations relating to its business transactions with Huawei and its affiliates (“Huawei”), which were added to the “Entity List” maintained by Department of Commerce (“DOC”) on May 16, 2019. The Company is cooperating fully with federal authorities in the investigation. The Company has maintained an export control compliance program and has been committed to comply fully with all applicable laws and regulations. In connection with this investigation, DOC requested the Company to suspend shipments of its products to Huawei, and the Company complied with such request. The Company is currently working with DOC to resolve this issue in order to resume shipments to Huawei. Given the case is in its early stages and still ongoing, the Company cannot estimate the reasonably possible loss or range of loss that may occur. Also, the Company is unable to predict the duration, scope, result or related costs of the investigation, although the Company expects to incur additional professional fees as a result of this matter. In addition, the Company is unable to predict, if any, further action that may be taken by the government in connection with the investigation, or what, if any, penalties, sanctions or remedial actions may be sought. The Company is a party to a variety of agreements that it has contracted with various third parties. Pursuant to these agreements, the Company may be obligated to indemnify another party to such an agreement with respect to certain matters. Typically, these obligations arise in the context of contracts entered into by the Company, under which the Company customarily agrees to hold the other party harmless against losses arising from a breach of representations and covenants related to such matters as title to assets sold, certain intellectual property rights, specified environmental matters and certain income taxes. In these circumstances, payment by the Company is customarily conditioned on the other party making a claim pursuant to the procedures specified in the particular contract, which procedures typically allow the Company to challenge the other party's claim. Further, the Company's obligations under these agreements may be limited in time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments made by it under these agreements. The Company has not historically paid or recorded any material indemnifications, and no accrual has been made at December 31, 2019 and June 30, 2019 . The Company has agreed to indemnify its directors and certain employees as permitted by law and pursuant to its Bye-laws, and has entered into indemnification agreements with its directors and executive officers. The Company has not recorded a liability associated with these indemnification arrangements, as it historically has not incurred any material costs associated with such indemnification obligations. Costs associated with such indemnification obligations may be mitigated by insurance coverage that the Company maintains. However, such insurance may not cover any, or may cover only a portion of, the amounts the Company may be required to pay. In addition, the Company may not be able to maintain such insurance coverage in the future.

Subsequent Events

Subsequent Events	6 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 20, 2020, the JV Company's expired two one-year loan agreements with China Merchant Bank and Chongqing LiangJiang New District China Merchants Group Limited Company in China were renewed. The JV Company borrowed RMB 80 million and 20 million (equivalent of $14.6 million in total based on the currency exchange rate as of January 20, 2020). Interest payments are due monthly and quarterly with the entire principal due not later than January 21, 2021.

The Company and Significant A_2

The Company and Significant Accounting Policies (Policies)	6 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Preparation	Basis of Preparation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2019 . All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the periods presented have been included in the interim periods. Operating results for the six months ended December 31, 2019 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2020 or any other interim period. The condensed consolidated balance sheet at June 30, 2019 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2019 .
Leases	Leases On July 1, 2019, the Company adopted Topic 842, Leases, using the modified retrospective method. Results for reporting periods beginning after July 1, 2019 were presented under Topic 842, while prior period amounts were not adjusted and continue to be reported in accordance with the historical accounts under Topic 840. The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use ("ROU") assets, current operating lease liabilities and long-term operating lease liabilities on the Company's condensed consolidated balance sheets. Finance leases are included in property, plant and equipment, finance lease liabilities and long-term finance leases liabilities on the condensed consolidated balance sheets. The Company elected the practical expedient permitted under the transition guidance, which allowed the Company to carryforward its historical lease classification, the Company's assessment on whether a contract was or contains a lease, and its initial direct costs for any leases that existed prior to July 1, 2019. The Company elected to combine its lease and non-lease components as a single lease component for all asset classes. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company uses an estimate of its incremental borrowing rate based on the information available at the lease commencement date. The operating lease ROU assets also include any lease payments made and excludes lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. Operating lease expense is generally recognized on a straight-line basis over the lease term. Variable lease payments are expensed as incurred and are not included within the operating lease ROU asset and lease liability calculation. The Company does not record leases on the condensed consolidated balance sheet with a term of one year or less. See Note 6 for further details.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, leases, share-based compensation, and useful lives for property, plant and equipment and intangible assets.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The fair value of cash equivalents is based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities. The carrying value of the company's debt is considered a reasonable estimate of fair value which is estimated by considering the current rates available to the Company for debt of the same remaining maturities, structure and terms of the debts.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss).
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Issued Accounting Standards not yet adopted In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2019-12 “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12") by removing certain exceptions to the general principles. The amendments will be effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early adoption of the amendments is permitted. Depending on the amendment, adoption may be applied on a retrospective, modified retrospective or prospective basis. We are currently evaluating the impacts of adoption of the new guidance to our consolidated financial statements. In August 2018, the FASB issued ASU 2018-15 “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract". These amendments align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contact with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by these amendments. ASU 2018-15 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2019. Early adoption is permitted. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13”). ASU 2018-13 amends existing fair value measurement disclosure requirements by adding, changing, or removing certain disclosures. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. ASU No. 2018-13 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2019. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses ("ASU 2016-13"). This accounting standard update changes the accounting for recognizing impairments of financial assets. Under the update, credit losses for certain types of financial instruments will be estimated based on expected losses. The update also modifies the impairment models for available-for-sale debt securities and for purchased financial assets with credit deterioration since their origination. This update is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The Company is currently evaluating the impact of this accounting standard update on its Consolidated Financial Statements. Recently Adopted Accounting Standards In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This guidance requires a dual approach for lessee accounting under which a lessee accounts for leases as finance leases or operating leases. Both finance and operating leases result in the lessee recognizing a right-of-use asset and a corresponding liability on its balance sheet, with differing methodology for income statement recognition. The Company adopted this standard as of July 1, 2019, using the modified retrospective transition method and recorded a cumulative-effect balance sheet adjustment. As a result of adopting ASU 2016-02 on July 1, 2019, the Company recognized operating lease right-of-use assets and corresponding operating lease liabilities of approximately $21 million each from existing leases on the Company's condensed consolidated balance sheet. See Note 6 for further details. In June 2018, the FASB issued ASU 2018-07, "Compensation -Stock Compensation: Improvement to Nonemployees Share-Based Payment Accounting ("ASU 2018-07"), which expands the scope of Topic 718 to include all share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 specifies that Topic 718 applies to all share-based payment transactions in which the grantor acquires goods and services to be used or consumed in its own operations by issuing share-based payment awards. ASU 2018-07 also clarifies that Topic 718 does not apply to share-based payments used to effectively provide (1) financing to the issuer or (2) awards granted in conjunction with selling goods or services to customers as part of a contract accounted for under ASC 606. ASU 2018-07 had no material impact on the Company's consolidated financial statements.
Concentration of Credit Risk	The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application and review of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers. Credit sales, which are mainly on credit terms of 30 to 60 days , are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its trade accounts receivable to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.

Net Income Per Common Share A_2

Net Income Per Common Share Attributable to Alpha and Omega Semiconductor Limited - (Tables)	6 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of basic and diluted net income (loss) per share attributable to common shareholders: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands, except per share data) Numerator: Net income (loss) attributable to Alpha and Omega Semiconductor Limited $ (1,005 ) $ (1,545 ) $ 4 $ 871 Denominator: Basic: Weighted average number of common shares used to compute basic net income per share 24,701 23,887 24,620 23,865 Diluted: Weighted average number of common shares used to compute basic net income per share 24,701 23,887 24,620 23,865 Effect of potentially dilutive securities: Stock options, RSUs and ESPP shares — — 742 648 Weighted average number of common shares used to compute diluted net income per share 24,701 23,887 25,362 24,513 Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited: Basic $ (0.04 ) $ (0.06 ) $ 0.00 $ 0.04 Diluted $ (0.04 ) $ (0.06 ) $ 0.00 $ 0.04
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following potential dilutive securities were excluded from the computation of diluted net income per share as their effect would have been anti-dilutive: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Employee stock options and RSUs 2,040 2,225 337 646 ESPP 868 1,240 597 508 Total potential dilutive securities 2,908 3,465 934 1,154

Concentration of Credit Risk _2

Concentration of Credit Risk and Significant Customers (Tables)	6 Months Ended
	Dec. 31, 2019
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk, by Risk Factor	Summarized below are individual customers whose revenue or accounts receivable balances were more than 10% of the respective total consolidated amounts: Three Months Ended December 31, Six Months Ended December 31, Percentage of revenue 2019 2018 2019 2018 Customer A 31.3 % 30.6 % 30.0 % 29.1 % Customer B 37.0 % 37.6 % 36.0 % 37.8 % December 31, June 30, Percentage of accounts receivable Customer A 14.0 % 12.1 % Customer B 39.9 % 19.7 % Customer C * 18.1 % Customer D * 13.3 %

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	Accounts receivable, net: December 31, June 30, (in thousands) Accounts receivable $ 58,859 $ 48,401 Less: Allowance for price adjustments (24,957 ) (24,075 ) Less: Allowance for doubtful accounts (30 ) (30 ) Accounts receivable, net $ 33,872 $ 24,296
Schedule of Inventory, Current	Inventories: December 31, June 30, (in thousands) Raw materials $ 58,454 $ 59,076 Work in-process 47,818 38,214 Finished goods 11,319 14,353 $ 117,591 $ 111,643
Other Current Assets	Other current assets: December 31, June 30, (in thousands) VAT receivable $ 28,125 $ 30,769 Other prepaid expenses 1,884 2,745 Prepaid insurance 1,238 939 Prepaid maintenance 858 481 Prepayment to supplier 1,048 583 Prepaid income tax 285 267 Customs deposit 195 114 Lease financing cost — 825 Interest receivable 679 379 Other receivable 83 — $ 34,395 $ 37,102
Property, Plant and Equipment	operty, plant and equipment, net: December 31, June 30, (in thousands) Land $ 4,877 $ 4,877 Building 59,329 36,205 Manufacturing machinery and facility equipment 434,089 303,750 Equipment and tooling 23,200 20,739 Computer equipment and software 38,413 34,048 Office furniture and equipment 3,378 3,243 Leasehold improvements 67,972 53,597 Land use rights 8,602 8,760 639,860 465,219 Less: accumulated depreciation (271,170 ) (252,982 ) 368,690 212,237 Equipment and construction in progress 47,365 197,500 Property, plant and equipment, net $ 416,055 $ 409,737
Intangible Assets Disclosure	Intangible assets, net: December 31, June 30, (in thousands) Patents and technology rights $ 18,037 $ 18,037 Trade name 268 268 Customer relationships 1,150 1,150 19,455 19,455 Less: accumulated amortization (2,898 ) (2,842 ) 16,557 16,613 Goodwill 269 269 Intangible assets, net $ 16,826 $ 16,882
Schedule of Other Assets, Noncurrent	Other long-term assets: December 31, June 30, (in thousands) Prepayments for property and equipment $ 4,043 $ 4,846 Investment in a privately held company 700 700 Lease financing costs — 1,758 Customs deposit 1,875 980 Other long-term deposits 1,595 889 Office leases deposits 1,044 1,031 Other 245 413 $ 9,502 $ 10,617
Schedule of Accrued Liabilities	Accrued liabilities: December 31, June 30, (in thousands) Accrued compensation and benefits $ 19,284 $ 16,385 Warranty accrual 651 623 Stock rotation accrual 3,836 1,921 Accrued professional fees 2,496 1,721 Accrued inventory 668 857 Accrued facilities related expenses 2,218 4,233 Accrued financing lease costs 715 728 Accrued property, plant and equipment 11,806 11,527 ESPP payable 623 585 Customer deposit 2,318 351 Other accrued expenses 8,079 5,144 $ 52,694 $ 44,075
Schedule of Product Warranty Liability	The activities in the warranty accrual, included in accrued liabilities, are as follows: Six Months Ended December 31, 2019 2018 (in thousands) Beginning balance $ 623 $ 535 Additions 130 189 Utilization (102 ) (69 ) Ending balance $ 651 $ 655
Stock Rotation Accrual	The activities in the stock rotation accrual, included in accrued liabilities, are as follows: Six Months Ended December 31, 2019 2018 (in thousands) Beginning balance $ 1,921 $ 1,750 Additions 5,990 2,229 Utilization (4,075 ) (2,132 ) Ending balance $ 3,836 $ 1,847
Other Long-Term Liabilities	Other long-term liabilities: December 31, June 30, (in thousands) Customer deposits $ 8,000 * $ 10,000 * Computer software liabilities 2,810 3,701 Other — 220 Other long-term liabilities $ 10,810 $ 13,921 * Customer deposits are from Customer A and Customer B for securing future product shipments from the Company. The Company reclassified $2.0 million of the customer deposit to short term accrued liabilities during the six months ended December 31, 2019 since the repayment of this amount is due within a year.

Bank Borrowing (Tables)

Bank Borrowing (Tables)	6 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Maturities	Maturities of short-term debt and long-term debt were as follows (in thousands): Year ending June 30, 2020 (Remaining) $ 13,738 2021 14,569 2022 20,115 2023 28,604 2024 12,175 Thereafter 8,975 Total principal of debts 98,176 Less: debt issuance costs (838 ) Total principal of debt, less debt issuance costs $ 97,338 Short-term Debt Long-term Debt Principal amount $ 21,212 $ 76,964 Less: debt issuance costs (183 ) (655 ) Total debt, less debt issuance costs $ 21,029 $ 76,309

Leases - (Tables)

Leases - (Tables)	6 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Components of Operating and Finance Lease Costs	The components of the Company’s operating and finance lease expenses are as follows for the period presented (in thousands): Six Months Ended December 31, 2019 Operating Leases: Fixed rent expense $ 2,614 Variable rent expense 421 Finance Lease: Amortization of equipment 1,716 Interest 1,457 Short-term leases Short-term lease expenses 152 Total lease expenses $ 6,360 Supplemental cash flow information related to the Company’s operating and finance lease is as follows (in thousands): Six Months Ended December 31, 2019 Cash paid from amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,541 Operating cash flows from finance lease $ 1,457 Financing cash flows from finance lease $ 3,403
Schedule of Lease Assets and Liabilities	Supplemental balance sheet information related to the Company’s operating and finance leases is as follows (in thousands, except lease term and discount rate): December 31, 2019 Operating Leases : ROU assets associated with operating leases $ 18,667 Finance Lease: Property, plant and equipment, gross 105,606 Accumulated depreciation (86,806 ) Property, plant and equipment, net 18,800 Weighted average remaining lease term (in years) Operating leases 9.73 Finance lease 3.22 Weighted average discount rate Operating leases 5.29 % Finance lease 5.46 %
Schedule of Operating Lease Future Minimum Lease Payments (Topic 842)	Future minimum lease payments are as follows as of December 31, 2019 (in thousands): Operating Leases Finance Leases The remainder of 2020 $ 2,417 $ 9,062 2021 3,248 17,477 2022 2,716 16,622 2023 2,360 12,048 2024 1,973 — 2025 1,466 — Thereafter 10,128 — Total minimum lease payments 24,308 55,209 Less amount representing interest (5,467 ) (4,893 ) Total lease liabilities $ 18,841 $ 50,316
Schedule of Finance Lease Future Minimum Lease Payments (Topic 842)	Future minimum lease payments are as follows as of December 31, 2019 (in thousands): Operating Leases Finance Leases The remainder of 2020 $ 2,417 $ 9,062 2021 3,248 17,477 2022 2,716 16,622 2023 2,360 12,048 2024 1,973 — 2025 1,466 — Thereafter 10,128 — Total minimum lease payments 24,308 55,209 Less amount representing interest (5,467 ) (4,893 ) Total lease liabilities $ 18,841 $ 50,316
Schedule of Future Minimum Rental Payments for Operating Leases (Topic 840)	Prior to the adoption of the new lease standard, future minimum lease payments as of June 30, 2019 were as follows (in thousands): Year ending June 30, Operating Leases Finance Leases 2020 $ 4,357 $ 14,219 2021 1,741 17,799 2022 1,164 16,928 2023 894 12,269 2024 1,002 — Thereafter 149 — Total minimum lease payments 9,307 61,215 Less amount representing interest — (6,479 ) Total lease liabilities $ 9,307 $ 54,736
Schedule of Future Minimum Lease Payments for Capital Leases (Topic 840)	Prior to the adoption of the new lease standard, future minimum lease payments as of June 30, 2019 were as follows (in thousands): Year ending June 30, Operating Leases Finance Leases 2020 $ 4,357 $ 14,219 2021 1,741 17,799 2022 1,164 16,928 2023 894 12,269 2024 1,002 — Thereafter 149 — Total minimum lease payments 9,307 61,215 Less amount representing interest — (6,479 ) Total lease liabilities $ 9,307 $ 54,736

Shareholders' Equity and Shar_2

Shareholders' Equity and Share-based Compensation (Tables)	6 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement, Noncash Expense [Abstract]
Restricted Stock Units Activity	The following table summarizes the Company's PRSUs activities for the six months ended December 31, 2019 : Number of Performance-based Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested at June 30, 2019 596,724 $ 13.95 1.88 $ 5,573,402 Forfeited (3,625 ) $ 15.11 Nonvested at December 31, 2019 593,099 $ 13.94 1.37 $ 8,078,008 Time-based Restricted Stock Units ("TRSU") The following table summarizes the Company's TRSU activities for the six months ended December 31, 2019 : Number of Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested at June 30, 2019 906,341 $ 14.09 1.62 $ 8,465,225 Granted 64,442 $ 12.24 Vested (73,312 ) $ 13.71 Forfeited (14,125 ) $ 14.12 Nonvested at December 31, 2019 883,346 $ 13.98 1.22 $ 12,031,173
Summary of Stock Option Activities	The following table summarizes the Company's stock option activities for the six months ended December 31, 2019 : Weighted Weighted Average Average Remaining Number of Exercise Price Contractual Aggregate Shares Per Share Term (in years) Intrinsic Value Outstanding at June 30, 2019 876,478 $ 10.98 3.06 $ 758,871 Exercised (2,500 ) $ 10.50 $ 4,726 Canceled or forfeited (5,000 ) $ 15.00 Outstanding at December 31, 2019 868,978 $ 10.96 2.58 $ 3,108,361 Options vested and expected to vest 868,978 $ 10.96 2.58 $ 3,108,361 Exercisable at December 31, 2019 868,978 $ 10.96 2.58 $ 3,108,361
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows: Six Months Ended December 31, 2019 Volatility rate 46.4% Risk-free interest rate 1.6% Expected term 1.3 years Dividend yield 0%
Share-based Compensation, Allocation of Recognized Period Costs	Share-based Compensation Expense T he total share-based compensation expense recognized in the condensed consolidated statements of operations for the periods presented was as follows: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Cost of goods sold $ 404 $ 541 $ 840 $ 1,038 Research and development 472 742 996 1,374 Selling, general and administrative 1,611 3,135 3,020 5,135 $ 2,487 $ 4,418 $ 4,856 $ 7,547

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	6 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Disaggregation of Revenue [Table Text Block]	The Company sells its products primarily to distributors in the Asia Pacific region, who in turn sell these products to end customers. Because the Company's distributors sell their products to end customers which may have a global presence, revenue by geographical location is not necessarily representative of the geographical distribution of sales to end user markets. The revenue by geographical location in the following tables is based on the country or region in which the products were shipped to: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Hong Kong $ 97,244 $ 87,180 $ 190,346 $ 178,771 China 16,571 24,760 33,083 45,157 South Korea 2,279 139 8,269 308 United States 898 1,967 1,999 3,940 Other countries 868 879 1,965 1,821 $ 117,860 $ 114,925 $ 235,662 $ 229,997 The following is a summary of revenue by product type: Three Months Ended December 31, Six Months Ended December 31, 2019 2018 2019 2018 (in thousands) (in thousands) Power discrete $ 101,491 $ 93,294 $ 202,032 $ 185,549 Power IC 14,655 19,384 30,379 38,799 Packaging and testing services 1,714 2,247 3,251 5,649 $ 117,860 $ 114,925 $ 235,662 $ 229,997
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Long-lived assets, net consisting of property, plant and equipment and land use rights, by geographical area are as follows: December 31, June 30, (in thousands) China $ 321,256 $ 321,145 United States 93,976 87,817 Other Countries 823 775 $ 416,055 $ 409,737

The Company and Significant A_3

The Company and Significant Accounting Policies - Basis of Preparation (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Property and equipment purchased but not yet paid (2018 amount is presented as revised, see Note 1)	$ 18,165	$ 30,335
Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Property and equipment purchased but not yet paid (2018 amount is presented as revised, see Note 1)		(31,300)
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Property and equipment purchased but not yet paid (2018 amount is presented as revised, see Note 1)		$ 61,600

The Company and Significant A_4

The Company and Significant Accounting Policies - Joint Venture (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Jul. 01, 2019
Operating lease right-of-use assets, net	$ 18,667
Operating lease liability	$ 18,841
Parent Company | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture')
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	51.00%
Chongqing Funds | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture')
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	49.00%
ASU 2016-02
Operating lease right-of-use assets, net		$ 21,000
Operating lease liability		$ 21,000

The Company and Significant A_5

The Company and Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jun. 30, 2019
Accounting Policies [Abstract]
Restricted cash	$ 4.2	$ 2.4

Net Income Per Common Share A_3

Net Income Per Common Share Attributable to Alpha and Omega Semiconductor Limited - Basic and Diluted Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income (loss) attributable to Alpha and Omega Semiconductor Limited	$ (1,005)	$ (1,545)	$ 4	$ 871
Basic:
Weighted average number of common shares used to compute basic net income per share	24,701	23,887	24,620	23,865
Effect of potentially dilutive securities:
Stock options, RSUs and ESPP shares	0	0	742	648
Weighted average number of common shares used to compute diluted net income per share	24,701	23,887	25,362	24,513
Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited:
Basic (in dollars per share)	$ (0.04)	$ (0.06)	$ 0	$ 0.04
Diluted (in dollars per share)	$ (0.04)	$ (0.06)	$ 0	$ 0.04

Net Income Per Common Share A_4

Net Income Per Common Share Attributable to Alpha and Omega Semiconductor Limited - Potential Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	2,908	3,465	934	1,154
Employee stock options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	2,040	2,225	337	646
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	868	1,240	597	508

Concentration of Credit Risk _3

Concentration of Credit Risk and Significant Customers - (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		8 Months Ended	12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Jun. 30, 2019
Concentration Risk
Revenue	$ 117,860		$ 114,925	$ 235,662	$ 229,997
Minimum
Concentration Risk
Terms of credit sales, (in days)				30 days
Maximum
Concentration Risk
Terms of credit sales, (in days)				60 days
Huawei | Revenue | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total							2.00%
Huawei | Minimum | Revenue | Customer Concentration Risk
Concentration Risk
Revenue						$ 11,000
Huawei | Maximum | Revenue | Customer Concentration Risk
Concentration Risk
Revenue						$ 13,000
Customer A | Revenue | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	31.30%		30.60%	30.00%	29.10%
Customer A | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	14.00%	12.10%
Customer B | Revenue | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	37.00%		37.60%	36.00%	37.80%
Customer B | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	39.90%	19.70%
Customer C | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total		18.10%
Customer D | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total		13.30%

Balance Sheet Components - Acco

Balance Sheet Components - Accounts receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 58,859	$ 48,401
Less: Allowance for price adjustments	(24,957)	(24,075)
Less: Allowance for doubtful accounts	(30)	(30)
Accounts receivable, net	$ 33,872	$ 24,296

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 58,454	$ 59,076
Work in-process	47,818	38,214
Finished goods	11,319	14,353
Inventory, net	$ 117,591	$ 111,643

Balance Sheet Components - Othe

Balance Sheet Components - Other current assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
VAT receivable	$ 28,125	$ 30,769
Other prepaid expenses	1,884	2,745
Prepaid insurance	1,238	939
Prepaid maintenance	858	481
Prepayment to supplier	1,048	583
Prepaid income tax	285	267
Customs deposit	195	114
Lease financing cost	0	825
Interest receivable	679	379
Other receivable	83	0
Other Assets, Current	$ 34,395	$ 37,102

Balance Sheet Components - Prop

Balance Sheet Components - Property, plant, and equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 639,860	$ 465,219
Land use rights	8,602	8,760
Less: accumulated depreciation	(271,170)	(252,982)
Property, plant and equipment excluding equipment and construction in progress, net	368,690	212,237
Equipment and construction in progress	47,365	197,500
Property, plant and equipment, net	416,055	409,737
Land
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	4,877	4,877
Building
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	59,329	36,205
Manufacturing machinery and facility equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	434,089	303,750
Equipment and tooling
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	23,200	20,739
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	38,413	34,048
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	3,378	3,243
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 67,972	$ 53,597

Balance Sheet Components - Inta

Balance Sheet Components - Intangible assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Schedule of Finite-lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	$ 19,455	$ 19,455
Less: accumulated amortization	(2,898)	(2,842)
Intangible Assets, Net (Excluding Goodwill)	16,557	16,613
Goodwill	269	269
Intangible assets, net	16,826	16,882
Patents and technology rights
Schedule of Finite-lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	18,037	18,037
Trade name
Schedule of Finite-lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	268	268
Customer relationships
Schedule of Finite-lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	$ 1,150	$ 1,150

Balance Sheet Components - In_2

Balance Sheet Components - Intangible Assets, Additional Information (Details) $ in Millions	Dec. 31, 2019USD ($)
STMicro | License fees
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 16.2

Balance Sheet Components - Ot_2

Balance Sheet Components - Other long term assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Prepayments for property and equipment	$ 4,043	$ 4,846
Investment in a privately held company	700	700
Lease financing costs, noncurrent	0	1,758
Custom deposit, noncurrent	1,875	980
Other long-term deposits	1,595	889
Office lease deposit, noncurrent	1,044	1,031
Other	245	413
Other long-term assets	$ 9,502	$ 10,617

Balance Sheet Components - Accr

Balance Sheet Components - Accrued liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and benefits	$ 19,284	$ 16,385
Warranty accrual	651	623	$ 655	$ 535
Stock rotation accrual	3,836	1,921	$ 1,847	$ 1,750
Accrued professional fees	2,496	1,721
Accrued inventory	668	857
Accrued facilities related expenses	2,218	4,233
Accrued financing lease costs	715	728
Accrued property, plant and equipment	11,806	11,527
ESPP payable	623	585
Customer deposit	2,318	351
Other accrued expenses	8,079	5,144
Accrued liabilities	$ 52,694	$ 44,075

Balance Sheet Components - Prod

Balance Sheet Components - Product Warranty Accrual (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Beginning balance	$ 623	$ 535
Additions	130	189
Utilization	(102)	(69)
Ending balance	$ 651	$ 655

Balance Sheet Components - Stoc

Balance Sheet Components - Stock Rotation Accrual (Details) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Stock Rotation Accrual Increae (Decrease) [Roll Forward]
Beginning balance	$ 1,921	$ 1,750
Additions	5,990	2,229
Utilization	(4,075)	(2,132)
Ending balance	$ 3,836	$ 1,847

Balance Sheet Components - Ot_3

Balance Sheet Components - Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Customer deposits	$ 8,000	$ 10,000
Computer software liabilities	2,810	3,701
Other	0	220
Other long-term liabilities	$ 10,810	$ 13,921

Balance Sheet Components - Ot_4

Balance Sheet Components - Other Long-Term Liabilities Reclassification (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Schedule Of Long-Term Liabilities [Line Items]
Customer deposits	$ (8,000)	$ (10,000)
Accrued liabilities	52,694	$ 44,075
Customer A And Customer B
Schedule Of Long-Term Liabilities [Line Items]
Customer deposits	(2,000)
Accrued liabilities	$ 2,000

Bank Borrowing (Details)

Bank Borrowing (Details)	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Aug. 09, 2019USD ($)	Mar. 12, 2019CNY (¥)	May 09, 2018CNY (¥)	Aug. 15, 2017USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2019USD ($)	Oct. 31, 2019CNY (¥)	Mar. 31, 2019CNY (¥)	Jul. 31, 2018USD ($)	Jan. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Oct. 31, 2019USD ($)	Sep. 23, 2019CNY (¥)	Sep. 23, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Mar. 21, 2019CNY (¥)Rate	Mar. 12, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 04, 2018CNY (¥)	Nov. 29, 2018CNY (¥)	Nov. 16, 2018CNY (¥)	Nov. 16, 2018USD ($)	May 09, 2018USD ($)	May 01, 2018USD ($)
Debt Instrument [Line Items]
Restricted cash													$ 4,200,000				$ 2,400,000
Maturities of debt
2020 (Remaining)													13,738,000
2020													14,569,000
2021													20,115,000
2022													28,604,000
2023													12,175,000
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five													8,975,000
Total principal of debt													98,176,000
Less: debt issuance costs													(838,000)
Total principal of debt, less debt issuance costs													97,338,000
Long-term Debt, Current Maturities													21,029,000				26,609,000
Long-term Debt, Excluding Current Maturities													76,309,000				$ 59,380,000
Long-term Debt, Current Maturities, And Short-Term Debt, Gross													21,212,000
Long-term Debt, Excluding Current Maturities, Gross													76,964,000
Debt Issuance Costs, Gross, Current													(183,000)
Debt Issuance Cost, Gross, Noncurrent													(655,000)
Long-term Debt, Current Maturities, And Short-term Debt													21,029,000
Loan Agreement November 29 2018
Debt Instrument [Line Items]
Debt instrument, face amount | ¥																							¥ 80,000,000
Loan agreements, short-term debt | ¥	¥ 0						¥ 0
Loan Agreement December 4 2018
Debt Instrument [Line Items]
Debt instrument, face amount | ¥																						¥ 20,000,000
Loan Agreements November 29 And December 4 2018
Debt Instrument [Line Items]
Debt instrument, face amount																					$ 14,500,000
Secured Debt | Accounts Receivable Factoring Agreement August 9 2019
Debt Instrument [Line Items]
Accounts receivable factoring agreement, maximum borrowing capacity, percent of net accounts receivable			70.00%
Accounts receivable factoring agreement, maximum borrowing capacity			$ 30,000,000
Accounts receivable factoring agreement, remaining borrowing capacity													30,000,000
Basis spread on variable rate			1.75%
Repayments of accounts receivable factoring agreement								$ 2,000,000
Accounts receivable factoring agreement, borrowed amount outstanding													0
Secured Debt
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity																											$ 17,800,000
Amount outstanding													16,400,000
Stated percentage																											5.04%
Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						$ 30,000,000
Debt instrument, term					5 years	5 years
Amount outstanding													20,500,000
Proceeds from lines of credit											$ 16,700,000	$ 13,200,000
Minimum | London Interbank Offered Rate (LIBOR) | Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Basis spread on variable rate						1.75%
Maximum | London Interbank Offered Rate (LIBOR) | Term Loan | Secured Debt | Variable Interest Rate Term Loan Maturing August 2022
Debt Instrument [Line Items]
Basis spread on variable rate						2.25%
Bank Of Communications Limited
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity									¥ 60,000,000					$ 8,500,000
Maturities of debt
Total principal of debt, less debt issuance costs													0
YinHai Leasing Company and China Import/Export Bank | Lease Financing
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					¥ 400,000,000																					$ 62,800,000
Nominal sale amount at end of lease term | ¥					¥ 1
Amount outstanding	352,000,000						352,000,000						50,300,000
Export-Import Bank Of China
Debt Instrument [Line Items]
Restricted cash				¥ 14,000,000																$ 2,000,000
Line of credit facility outstanding balance	197,000,000	$ 28,200,000
Export-Import Bank Of China | Secured Debt
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity				¥ 200,000,000																$ 29,800,000
Proceeds from lines of credit | ¥							10,000,000			¥ 190,000,000
Repayments of Lines of Credit | ¥							¥ 3,000,000
Maturities of debt
Line Of Credit Facility, Interest Rate During Period, China Base Rate Multiplier				1.1
Line of Credit Facility, Interest Rate During Period				5.39%
China Development Bank | Secured Debt
Debt Instrument [Line Items]
Debt instrument, face amount													24,000,000
Basis spread on variable rate							2.80%	2.80%
Maturities of debt
Total principal of debt, less debt issuance costs													24,000,000
China | Bank Of Communications Limited | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate, multiple									1.05					1.05
Basis spread on variable rate									4.99%
China | YinHai Leasing Company and China Import/Export Bank | Base Rate | Lease Financing
Debt Instrument [Line Items]
Basis spread on variable rate, multiple					1.15																					1.15
Basis spread on variable rate					5.4625%
Foreign Line of Credit | Loan Agreement September 23 2019
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity															¥ 50,000,000	$ 7,100,000
Loan agreements, short-term debt													6,300,000
Foreign Line of Credit | Industrial And Commercial Bank of China
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity																								¥ 72,000,000	$ 10,300,000
Loan agreements, short-term debt													0
Loans Payable | Loan Agreement March 21 2019
Debt Instrument [Line Items]
Debt instrument, face amount																		$ 3,000,000	¥ 20,000,000
Loan agreements, short-term debt	¥ 20,000,000						¥ 20,000,000						$ 2,900,000
Short-term debt, fixed interest rate | Rate																			5.44%

Leases - Narrative (Details)

Leases - Narrative (Details) - May 09, 2018 ¥ in Millions, $ in Millions	CNY (¥)	USD ($)
Lease Financing | YinHai Leasing Company and China Import/Export Bank
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	¥ 400	$ 62.8

Leases - Schedule of Operating

Leases - Schedule of Operating and Finance Lease Expenses (Details) $ in Thousands	6 Months Ended
	Dec. 31, 2019USD ($)
Operating Leases:
Fixed rent expense	$ 2,614
Variable rent expense	421
Finance Lease:
Amortization of equipment	1,716
Interest	1,457
Short-term leases
Short-term lease expenses	152
Total lease expenses	$ 6,360

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) $ in Thousands	Dec. 31, 2019USD ($)
Operating Leases:
ROU assets associated with operating leases	$ 18,667
Finance Lease:
Property, plant and equipment, gross	105,606
Accumulated depreciation	(86,806)
Property, plant and equipment, net	$ 18,800
Weighted average remaining lease term (in years)
Operating leases	9 years 8 months 23 days
Finance lease	3 years 2 months 19 days
Weighted average discount rate
Operating leases	5.29%
Finance lease	5.46%

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) $ in Thousands	6 Months Ended
	Dec. 31, 2019USD ($)
Cash paid from amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 2,541
Operating cash flows from finance lease	1,457
Financing cash flows from finance lease	$ 3,403

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments (Topic 842) (Details) $ in Thousands	Dec. 31, 2019USD ($)
Operating Leases
The remainder of 2020	$ 2,417
2021	3,248
2022	2,716
2023	2,360
2024	1,973
2025	1,466
Thereafter	10,128
Total minimum lease payments	24,308
Less amount representing interest	(5,467)
Total lease liabilities	18,841
Finance Leases
The remainder of 2020	9,062
2021	17,477
2022	16,622
2023	12,048
2024	0
2025	0
Thereafter	0
Total minimum lease payments	55,209
Less amount representing interest	(4,893)
Total lease liabilities	$ 50,316

Leases - Future Minimum Lease_2

Leases - Future Minimum Lease Payments (Topic 840) (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases, Operating [Abstract]
2020	$ 4,357
2021	1,741
2022	1,164
2023	894
2024	1,002
Thereafter	149
Total lease liabilities	9,307
Leases, Capital [Abstract]
2020	14,219
2021	17,799
2022	16,928
2023	12,269
2024	0
Thereafter	0
Total minimum lease payments	61,215
Less amount representing interest	(6,479)
Total lease liabilities	$ 54,736

Shareholders' Equity and Shar_3

Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		107 Months Ended	110 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Treasury Stock, Shares, Retired			0
Share repurchase program, authorized amount (USD in Millions)	$ 30,000		$ 30,000			$ 30,000
Repurchase of common shares under shares repurchase program			0			6,784,648
Treasury stock acquired, average price per share (in dollars per share)						$ 9.92
Repurchase of common shares under shares repurchase program				$ (1,501)		$ (67,300)
Shares repurchase program, remaining balance	$ 13,400		$ 13,400			$ 13,400
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0	0	0	0
Share-based payment arrangement, expense	$ 2,487	$ 4,418	$ 4,856	$ 7,547
Treasury Stock Reissued
Class of Stock [Line Items]
Treasury stock acquired, average price per share (in dollars per share)					$ 10.39
Shares reissued (in shares)						140,328
Shares reissued, average price (in dollars per share)						$ 5.50
Market-based Restricted Stock Units (MSU) [Member]
Class of Stock [Line Items]
Share-based payment arrangement, expense	$ 100	$ 200	$ 300	$ 400

Shareholders' Equity and Shar_4

Shareholders' Equity and Share-based Compensation - Time-based Restricted Stock Activity (Details) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average remaining recognition period (in years)	1 year 10 months 24 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested at June 30, 2018 (in shares)			906,341
Granted (in shares)			64,442
Vested (in shares)			(73,312)
Forfeited (in shares)			(14,125)
Nonvested at March 31, 2019 (in shares)	883,346	906,341	883,346
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonvested at June 30, 2018 (in dollars per share)			$ 14.09
Granted (in dollars per share)			12.24
Vested (in dollars per share)			13.71
Forfeited (in dollars per share)			14.12
Nonvested at March 31, 2019 (in dollars per share	$ 13.98	$ 14.09	$ 13.98
Weighted average remaining recognition period (in years)	1 year 2 months 19 days	1 year 7 months 13 days
Aggregate Intrinsic Value	$ 12,031,173	$ 8,465,225	$ 12,031,173

Shareholders' Equity and Shar_5

Shareholders' Equity and Share-based Compensation - Market-based Restricted Stock Units Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 2,487	$ 4,418		$ 4,856	$ 7,547
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average remaining recognition period (in years)	1 year 10 months 24 days
Market-based Restricted Stock Units (MSU) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate				2.70%
Expected term				3 years 6 months
Expected volatility				38.80%
Dividend yield				0.00%
Share-based payment arrangement, expense	$ 100	$ 200		$ 300	$ 400
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)			1,310,000
Market-based Restricted Stock Units (MSU) [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period				4 years 6 months
Market-based Restricted Stock Units (MSU) [Member] | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award service period				7 years 6 months

Shareholders' Equity and Shar_6

Shareholders' Equity and Share-based Compensation - Performance-based Restricted Stock Units (Details) - USD ($)	1 Months Ended			3 Months Ended				6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense				$ 2,487,000		$ 4,418,000		$ 4,856,000	$ 7,547,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted average remaining recognition period (in years)				1 year 10 months 24 days
Performance Based Restricted Stock Units (PRSUs) Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense				$ 500,000		800,000		$ 700,000	1,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested at June 30, 2018 (in shares)								596,724
Granted (in shares)	291,750	298,050	170,000
Forfeited (in shares)								(3,625)
Nonvested at March 31, 2019 (in shares)				593,099	596,724			593,099
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonvested at June 30, 2018 (in dollars per share)								$ 13.95
Forfeited (in dollars per share)								15.11
Nonvested at March 31, 2019 (in dollars per share				$ 13.94	$ 13.95			$ 13.94
Weighted average remaining recognition period (in years)				1 year 4 months 13 days	1 year 10 months 17 days
Aggregate Intrinsic Value				$ 8,078,008	$ 5,573,402			$ 8,078,008
Market-based Restricted Stock Units (MSU) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense				$ 100,000		$ 200,000		$ 300,000	$ 400,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted (in shares)							1,310,000

Shareholders' Equity and Shar_7

Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at June 30, 2019 (in shares)			876,478
Exercised (in shares)			2,500
Canceled or forfeited (in shares)			5,000
Outstanding at December 31, 2019 (In shares)	868,978	876,478	868,978
Options vested and expected to vest (in shares)	868,978		868,978
Exercisable at December 31, 2019 (in shares)	868,978		868,978
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at June 30, 2019 (in dollars per share)			$ 10.98
Exercised (in dollars per share)			10.50
Canceled or forfeited (in dollars per share)			15
Outstanding at December 31, 2019 (in dollars per share)	$ 10.96	$ 10.98	10.96
Options vested and expected to vest (in dollars per share)	10.96		10.96
Exercisable at December 31, 2019 (in dollars per share)	$ 10.96		$ 10.96
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options outstanding, Weighted-Average Remaining Contractual Life (in years)		3 years 22 days	2 years 6 months 29 days
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)			2 years 6 months 29 days
Exercisable at December 31, 2019, Weighted Average Remaining Contractual Life (in years)	2 years 6 months 29 days
Options outstanding, Aggregate Intrinsic Value	$ 3,108,361	$ 758,871	$ 3,108,361
Exercised, Aggregate Intrinsic Value			4,726
Options vested and expected to vest, Aggregate Intrinsic Value	3,108,361		3,108,361
Exercisable at December 31, 2019, Aggregate Intrinsic Value	$ 3,108,361		$ 3,108,361

Shareholders' Equity and Shar_8

Shareholders' Equity and Share-based Compensation - Employee Share Purchase Plan (Details) - shares	6 Months Ended	110 Months Ended
	Dec. 31, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of common shares under shares repurchase program	0	6,784,648
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility rate	46.40%
Risk-free interest rate	1.60%
Expected term	1 year 3 months 18 days
Dividend yield	0.00%

Shareholders' Equity and Shar_9

Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) - USD ($)	1 Months Ended			3 Months Ended				6 Months Ended		110 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense				$ 2,487,000		$ 4,418,000		$ 4,856,000	$ 7,547,000
Repurchase of common shares under shares repurchase program								0		6,784,648
Options outstanding, Weighted-Average Remaining Contractual Life (in years)					3 years 22 days			2 years 6 months 29 days
Options vested and expected to vest (in shares)				868,978				868,978		868,978
Options vested and expected to vest (in dollars per share)				$ 10.96				$ 10.96		$ 10.96
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)								2 years 6 months 29 days
Options vested and expected to vest, Aggregate Intrinsic Value				$ 3,108,361				$ 3,108,361		$ 3,108,361
Exercisable at December 31, 2019 (in shares)				868,978				868,978		868,978
Exercisable at December 31, 2019 (in dollars per share)				$ 10.96				$ 10.96		$ 10.96
Exercisable at December 31, 2019, Weighted Average Remaining Contractual Life (in years)				2 years 6 months 29 days
Exercisable at December 31, 2019, Aggregate Intrinsic Value				$ 3,108,361				$ 3,108,361		$ 3,108,361
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at June 30, 2019 (in shares)								876,478
Outstanding at December 31, 2019 (In shares)				868,978	876,478			868,978		868,978
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at June 30, 2019 (in dollars per share)								$ 10.98
Outstanding at December 31, 2019 (in dollars per share)				$ 10.96	$ 10.98			$ 10.96		$ 10.96
Options outstanding, Aggregate Intrinsic Value				$ 3,108,361	$ 758,871			$ 3,108,361		$ 3,108,361
Market-based Restricted Stock Units (MSU) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense				100,000		200,000		300,000	400,000
Granted (in shares)							1,310,000
Performance Based Restricted Stock Units (PRSUs) Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, expense				$ 500,000		$ 800,000		$ 700,000	$ 1,400,000
Granted (in shares)	291,750	298,050	170,000

Shareholders' Equity and Sha_10

Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based payment arrangement, expense	$ 2,487	$ 4,418	$ 4,856	$ 7,547
Unrecognized compensation expense	$ 9,300		9,300
Recognition period of share-based compensation expense (in years)	1 year 10 months 24 days
Cost of goods sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based payment arrangement, expense	$ 404	541	840	1,038
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based payment arrangement, expense	472	742	996	1,374
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based payment arrangement, expense	$ 1,611	$ 3,135	$ 3,020	$ 5,135

Income Taxes - Narrative (Deta

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense	$ 568	$ 701	$ 978	$ 1,261
Discrete income tax expense			$ 30	$ 30
Estimated effective income tax rate excluding discrete income tax expense	(13.80%)	(13.80%)	(17.40%)	(23.70%)
Unrecognized tax benefits	$ 7,300		$ 7,300
Unrecognized tax benefit that would impact effective tax rate	$ 4,300		$ 4,300

Segment and Geographic Inform_3

Segment and Geographic Information - Revenue by Location and Product Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 117,860	$ 114,925	$ 235,662	$ 229,997
Power discrete
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	101,491	93,294	202,032	185,549
Power IC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	14,655	19,384	30,379	38,799
Packaging and testing services
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,714	2,247	3,251	5,649
Hong Kong
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	97,244	87,180	190,346	178,771
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	16,571	24,760	33,083	45,157
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	2,279	139	8,269	308
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	898	1,967	1,999	3,940
Other countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 868	$ 879	$ 1,965	$ 1,821

Segment and Geographic Inform_4

Segment and Geographic Information - Long-lived Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jun. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	$ 416,055	$ 409,737
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	321,256	321,145
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	93,976	87,817
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net and land use rights, net	$ 823	$ 775

Segment and Geographic Inform_5

Segment and Geographic Information - Narratives (Details)	6 Months Ended
	Dec. 31, 2019Segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

Commitments and Contingencies -

Commitments and Contingencies - Purchase Commitments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jun. 30, 2019
Raw materials, wafers, and packaging and testing services puchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 52	$ 59.5
Property and equipment purchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 24.3	$ 33.8

Commitments and Contingencies_2

Commitments and Contingencies - Contingencies and Indemnities (Details) - USD ($)	Dec. 31, 2019	Jun. 30, 2019
Indemnification Agreement
Loss Contingencies [Line Items]
Indemnifications accrual	$ 0	$ 0

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details) - Jan. 20, 2020 - Subsequent Event $ in Millions	CNY (¥)	USD ($)
Loan Agreement January 20, 2020, Loan One
Subsequent Event [Line Items]
Debt instrument, face amount	¥ 80,000,000
Loan Agreement January 20, 2020, Loan Two
Subsequent Event [Line Items]
Debt instrument, face amount	¥ 20,000,000
Loan Agreement January 20, 2020, Loan One And Two
Subsequent Event [Line Items]
Debt instrument, face amount | $		$ 14.6