Alpha and Omega Semiconductor Limited (AOSL) 10-Q 6 Nov 15 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	ALPHA & OMEGA SEMICONDUCTOR Ltd
Entity Central Index Key	1,387,467
Current Fiscal Year End Date	--06-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		22,200,060

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Current assets:
Cash and cash equivalents	$ 72,868	$ 106,085
Restricted cash	196	368
Accounts receivable, net	37,198	38,781
Inventories	61,958	64,175
Deferred income tax assets	2,424	2,205
Other current assets	4,174	4,279
Total current assets	178,818	215,893
Property, plant and equipment, net	117,431	119,579
Intangible assets, net	16	17
Goodwill	269	269
Deferred income tax assets - long term	10,482	10,848
Other long-term assets	1,522	2,011
Total assets	308,538	348,617
Current liabilities:
Accounts payable	37,689	44,083
Accrued liabilities	21,225	19,225
Income taxes payable	1,748	1,372
Deferred margin	714	716
Capital leases	714	941
Total current liabilities	62,090	66,337
Income taxes payable - long term	1,614	1,601
Deferred income tax liabilities	3,972	3,548
Capital leases - long term	64	64
Other long term liabilities	902	953
Total liabilities	$ 68,642	$ 72,503
Commitments and contingencies (Note 8)
Preferred shares, par value $0.002 per share:
Authorized: 10,000 shares, issued and outstanding: none at September 30, 2015 and June 30, 2015	$ 0	$ 0
Common shares, par value $0.002 per share:
Authorized: 50,000 shares, issued and outstanding: 27,411 shares and 22,483 shares, respectively at September 30, 2015 and 27,314 shares and 26,316 shares, respectively at June 30, 2015	55	55
Treasury shares at cost, 4,928 shares at September 30, 2015 and 998 shares at June 30, 2015	(43,833)	(8,593)
Additional paid-in capital	182,203	181,040
Accumulated other comprehensive income	739	905
Retained earnings	100,732	102,707
Total shareholders’ equity	239,896	276,114
Total liabilities and shareholders’ equity	$ 308,538	$ 348,617

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2015	Jun. 30, 2015
Common shares, par value (in dollars per share)	$ 0.002	$ 0.002
Common shares, authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	27,411,000	27,314,000
Common stock, shares outstanding (in shares)	22,483,000	26,316,000
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)	4,928,000	998,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Revenue	$ 81,439	$ 88,217
Cost of goods sold	66,378	70,057
Gross profit	15,061	18,160
Operating expenses
Research and development	6,164	6,796
Selling, general and administrative	9,659	9,604
Total operating expenses	15,823	16,400
Operating income (loss)	(762)	1,760
Interest income and other, net	11	48
Interest expense	(10)	(73)
Income (Loss) before income taxes	(761)	1,735
Income tax expense	1,214	1,171
Net income (loss)	$ (1,975)	$ 564
Net income (loss) per share
Basic (in dollars per share)	$ (0.09)	$ 0.02
Diluted (in dollars per share)	$ (0.09)	$ 0.02
Weighted average number of common shares used to compute net income (loss) per share
Basic (in shares)	22,698	26,385
Diluted (in shares)	22,698	27,003

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Net income (loss)	$ (1,975)	$ 564
Foreign currency translation adjustment, net of tax	(166)	(48)
Total comprehensive income (loss)	$ (2,141)	$ 516

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities
Net income (loss)	$ (1,975)	$ 564
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	6,894	6,955
Amortization	1	91
Share-based compensation expense	789	1,102
Deferred income taxes, net	571	54
Loss on disposal of property and equipment	0	22
Government grant via forgiven loan	0	(250)
Changes in assets and liabilities:
Accounts receivable	1,583	1,469
Inventories	2,217	(1,849)
Other current and long-term assets	595	(383)
Accounts payable	(5,193)	(515)
Income taxes payable	389	472
Accrued and other liabilities	1,885	(103)
Net cash provided by operating activities	7,756	7,629
Cash flows from investing activities
Purchases of property and equipment	(6,002)	(2,345)
Restricted cash released (placed)	172	(122)
Net cash used in investing activities	(5,830)	(2,467)
Cash flows from financing activities
Proceeds from exercise of stock options	424	858
Payment for repurchase of common shares	(35,240)	0
Repayments of borrowings	0	(5,714)
Principal payments on capital leases	(227)	(237)
Net cash used in financing activities	(35,043)	(5,093)
Effect of exchange rate changes on cash and cash equivalents	(100)	(23)
Net increase (decrease) in cash and cash equivalents	(33,217)	46
Cash and cash equivalents at beginning of period	106,085	117,788
Cash and cash equivalents at end of period	72,868	117,834
Supplemental disclosures of non-cash investing and financing information:
Property and equipment purchased but not yet paid	$ 4,472	$ 5,594

The Company and Significant Acc

The Company and Significant Accounting Policies	3 Months Ended
	Sep. 30, 2015
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, 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, Taiwan, Korea and Japan. 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, 2015 . 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 period presented have been included in the interim periods. Operating results for the three months ended September 30, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2016 . The condensed consolidated balance sheet at June 30, 2015 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, 2015 . 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, share-based compensation, and useful lives for property, plant and equipment and intangible assets. Fair Value of Financial Instruments The fair value of cash equivalents are 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 In July 2015, the FASB issued No. 2015-11, Inventory - Simplifying the Measurement of Inventory("ASU 2015-11"). ASU 2015-11 is additional guidance regarding the subsequent measurement of inventory by requiring inventory to be measured at the lower of cost and net realizable value. This guidance is effective for fiscal years and interim periods beginning after December 15, 2016. Early adoption is permitted. 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 May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers(“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In July 2015, the FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. In August 2015 the FASB issued ASU 2015-14, Revenue from Contracts with customers - Deferral of the Effective Date", that defers by one year the effective date of ASU 2014-09. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements. In August 2014, the FASB issued amended standards No. 2014-15, Presentation of Financial Statements - Going Concern ('ASU 2014-15"), to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures requirement. The amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation for each annual and interim reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. 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 February 2015, the FASB issued ASU No. 2015-2, “Consolidation (Topic 820): Amendments to the Consolidation Analysis.” ASU 2015-2 provides a revised consolidation model for all reporting entities to use in evaluating whether they should consolidate certain legal entities. All legal entities will be subject to reevaluation under this revised consolidation model. The revised consolidation model, among other things, (i) modifies the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, (ii) eliminates the presumption that a general partner should consolidate a limited partnership, and (iii) modifies the consolidation analysis of reporting entities that are involved with VIEs through fee arrangements and related party relationships. ASU 2015-2 is effective for fiscal years, and interim reporting periods within those fiscal years, beginning after December 15, 2015. 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 April 2015, the FASB issued ASU No. 2015-03, Interest -Imputation of Interest(Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts and the accounting for debt issue costs under IFRS. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. ASU 2015-03 is effective for the annual period ending after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments in this Update is permitted for financial statements that have not been previously issued. 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.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share The following table presents the calculation of basic and diluted net income (loss) per share: Three Months Ended September 30, 2015 2014 (in thousands, except per share data) Numerator: Net income (loss) $ (1,975 ) $ 564 Denominator: Basic: Weighted average number of common shares used to compute basic net income (loss) per share 22,698 26,385 Diluted: Weighted average number of common shares used to compute basic net income (loss) per share 22,698 26,385 Effect of potentially dilutive securities: Stock options, RSUs and ESPP shares — 618 Weighted average number of common shares used to compute diluted net income (loss) per share 22,698 27,003 Net income (loss) per share: Basic $ (0.09 ) $ 0.02 Diluted $ (0.09 ) $ 0.02 The following potential dilutive securities were excluded from the computation of diluted net income (loss) per share as their effect would have been anti-dilutive: Three Months Ended September 30, 2015 2014 (in thousands) Employee stock options and RSUs 3,617 2,393 ESPP to purchase common shares 188 — Total potential dilutive securities 3,805 2,393

Concentration of Credit Risk an

Concentration of Credit Risk and Significant Customers	3 Months Ended
	Sep. 30, 2015
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 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 bad debt 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. Summarized below are individual customers whose revenue or accounts receivable balances were 10% or higher than the respective total consolidated amounts: Three Months Ended September 30, Percentage of revenue 2015 2014 Customer A 23.1 % 24.1 % Customer B 36.0 % 39.6 % Customer C 14.3 % 12.9 % September 30, June 30, Percentage of accounts receivable Customer A 19.4 % 29.4 % Customer B 27.3 % 27.7 % Customer C 25.4 % 14.7 %

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Sep. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Accounts receivable: September 30, June 30, (in thousands) Accounts receivable $ 54,630 $ 58,249 Less: Allowance for price adjustments (17,402 ) (19,438 ) Less: Allowance for doubtful accounts (30 ) (30 ) Accounts receivable, net $ 37,198 $ 38,781 Inventories: September 30, June 30, (in thousands) Raw materials $ 20,242 $ 19,423 Work in-process 31,586 31,269 Finished goods 10,130 13,483 $ 61,958 $ 64,175 Property, plant and equipment, net: September 30, June 30, (in thousands) Land $ 4,877 $ 4,877 Building 4,243 4,243 Manufacturing machinery and equipment 183,888 172,467 Equipment and tooling 11,821 11,261 Computer equipment and software 20,739 20,602 Office furniture and equipment 1,798 1,762 Leasehold improvements 27,842 27,568 255,208 242,780 Less: Accumulated depreciation (148,628 ) (141,883 ) 106,580 100,897 Equipment and construction in progress 10,851 18,682 Property, plant and equipment, net $ 117,431 $ 119,579 Other long-term assets: September 30, June 30, (in thousands) Prepayments for property and equipment $ 76 $ 692 Investment in a privately held company 100 100 Office leases deposits 1,343 1,215 Other 3 4 $ 1,522 $ 2,011 Accrued liabilities: September 30, June 30, (in thousands) Accrued compensation and benefit $ 6,419 $ 5,600 Accrued vacation 1,828 1,830 Accrued bonuses 1,120 1,152 Warranty accrual 2,203 1,957 Stock rotation accrual 1,910 1,894 Accrued professional fees 1,420 1,402 ESPP payable 827 343 Customer deposits 611 149 Accrued inventory 699 697 Accrued facilities related expenses 1,389 1,367 Other accrued expenses 2,799 2,834 $ 21,225 $ 19,225 The activities in the warranty accrual, included in accrued liabilities, are as follows: Three Months Ended September 30, 2015 2014 (in thousands) Beginning balance $ 1,957 $ 1,346 Additions 305 530 Utilization (59 ) (646 ) Ending balance $ 2,203 $ 1,230 The activities in the stock rotation accrual, included in accrued liabilities, are as follows: Three Months Ended September 30, 2015 2014 (in thousands) Beginning balance $ 1,894 $ 1,645 Additions 1,510 1,294 Utilization (1,494 ) (1,332 ) Ending balance $ 1,910 $ 1,607 Other Long-term liabilities: September 30, June 30, (in thousands) Deferred rent $ 902 $ 953

Shareholders' Equity and Share-

Shareholders' Equity and Share-based Compensation	3 Months Ended
	Sep. 30, 2015
Share-based Compensation [Abstract]
Shareholders' Equity and Share-based Compensation	Shareholders' Equity and Share-based Compensation Share Repurchase On May 8, 2014, the Company's Board of Directors reactivated its existing $25.0 million share repurchase program which was originally authorized on October 22, 2010. The Board authorized management to repurchase, subject to oversight by the Board, its common shares up to remaining balance of the program, or $22.7 million . In April 2015, the Board of Directors approved an increase in the remaining available amount under the Company’s share repurchase program from approximately $17.8 million to $50.0 million . The repurchases may be made from the open market pursuant to a pre-established Rule 10b5-1 trading plan (as amended, the "Repurchase Trading Plan") or through privately negotiated transactions. The amount and timing of any repurchases depend on a number of factors, including but not limited to, the Company's trading price, volume and availability of its common shares, applicable legal requirements, its business and financial conditions an general market environment. There is no guarantee that any repurchases under the Program will be made or that such repurchases would enhance the value of our shares. The Company accounts for treasury stock under the cost method. Shares repurchased 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 are charged to retained earnings. In June 2015, the Company commenced a modified Dutch auction tender offer (the "Tender Offer") to repurchase an aggregate of $30.0 million of its outstanding common shares with a price range between $8.50 and $9.20 per share. In July 2015, the Company completed the Tender Offer in which it purchased 3,296,703 shares of its common shares, at a purchase price of $9.10 per share, for an aggregate purchase price of $30.0 million , excluding fees and expenses relating to the Tender Offer. These shares represent approximately 12.53% of the total number of the Company's common shares issued and outstanding as of June 30, 2015. The Tender Offer was part of the $50.0 million share repurchase program approved by the Board in April 15, 2015. Immediately following the completion of the Tender Offer, approximately $18.2 million remained available under the share repurchase program. During the three months ended September 30, 2015, the Company repurchased 3,930,106 shares from the open market, including 3,296,703 shares in the Tender Offer, for a total cost of $35.0 million , at an average price of $8.90 per share, excluding fees and related expenses of $0.3 million , under the share repurchase program. Since the inception of the program in 2010, the Company repurchased an aggregate of 4,957,700 shares from the open market for a total cost of $44.0 million , at an average price of $8.87 per share, excluding fees and related expenses. No repurchased shares have been retired. Of the 4,957,700 repurchased shares, 29,675 shares with a weighted average repurchase price of $13.84 per share, were reissued at an average price of $2.19 per share for option exercises and vested restricted share units. Stock Options The following table summarizes the Company's stock option activities for the three months ended September 30, 2015 : Weighted Average Number of Exercise Price Aggregate Shares Per Share Intrinsic Value Outstanding at June 30, 2015 2,836,217 $ 10.77 $ 1,410,538 Granted — $ — Exercised (78,453 ) $ 5.41 $ 219,159 Canceled or forfeited (81,283 ) $ 7.98 Outstanding at September 30, 2015 2,676,481 $ 11.01 $ 284,049 Information with respect to stock options outstanding and exercisable at September 30, 2015 is as follows: Options Outstanding Options Vested and Exercisable Number Outstanding Weighted-Average Weighted-Average Number Exercisable Weighted-Average Total options outstanding 2,676,481 4.33 $ 11.01 2,256,226 $ 11.59 Options vested and expected to vest 2,636,712 4.27 $ 11.06 Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options. The fair value of stock options granted were estimated at the date of grant using the Black-Scholes option valuation model for the three months ended September 30, 2015 with the following weighted average assumptions: Three Months Ended September 30, 2015 Volatility rate 40.13% Risk-free interest rate 1.7% Expected term 5.5 years Dividend yield 0% Historically, the Company estimates its expected volatility based on that of the publicly traded shares of industry peers over a period equivalent to the expected term of the stock awards granted. Beginning in July 2015, the Company's publicly traded shares history is also included in estimating the volatility rate. Restricted Stock Units ("RSU") The following table summarizes the Company's RSU activities for the three months ended September 30, 2015 : Number of Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Recognition Period (Years) Aggregate Intrinsic Value Nonvested at June 30, 2015 873,946 $ 8.64 1.77 $ 7,638,288 Granted 49,690 $ 7.76 Vested (24,682 ) $ 9.32 Forfeited (53,480 ) $ 8.67 Nonvested at September 30, 2015 845,474 $ 8.57 1.60 $ 6,586,242 RSUs vested and expected to vest 732,498 1.50 $ 5,706,155 The fair value of RSU is estimated based on the market price of the Company's share on the date of grant. Employee Share Purchase Plan ("ESPP") The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows: Three Months Ended September 30, 2015 Volatility rate 31.4% Risk-free interest rate 0.1% - 0.6% Expected term 1.3 years Dividend yield 0% Share-based Compensation Expense T he total share-based compensation expense related to stock options, ESPP and RSUs described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows: Three Months Ended September 30, 2015 2014 (in thousands) Cost of goods sold $ 131 $ 154 Research and development 193 206 Selling, general and administrative 465 742 $ 789 $ 1,102 Total unrecognized stock-based compensation expense as of September 30, 2015 was $4.0 million , which includes estimated forfeitures and is expected to be recognized over a weighted-average period of 1.5 years.

Income Taxes

Income Taxes	3 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recognized income tax expense of approximately $1.2 million and $1.2 million for the three months ended September 30, 2015 and 2014 , respectively. The estimated effective tax rate for the three months ended September 30, 2015 was (159.5)% compared to 67.5% for the three months ended September 30, 2014 . 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 and 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 2015 remain open to examination by U.S. federal and state tax authorities. The tax years 2009 to 2015 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 September 30, 2015 , the gross amount of unrecognized tax benefits was approximately $6.4 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. A final decision has yet to be issued by the Tax Court due to other outstanding issues related to the case. At this time, the U.S. Department of the Treasury has not withdrawn the requirement to include stock-based compensation from its regulations. Due to the uncertainty surrounding the status of the current regulations, questions related to the scope of potential benefits, and the risk of the Tax Court’s decision being overturned upon appeal, the Company has not recorded any benefit as of September 30, 2015. The Company will continue to monitor ongoing developments and potential impacts to its financial statements.

Segment and Geographic Informat

Segment and Geographic Information	3 Months Ended
	Sep. 30, 2015
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 to which the products were shipped to: Three Months Ended September 30, 2015 2014 (in thousands) Hong Kong $ 70,453 $ 75,247 China 9,016 10,957 South Korea 658 639 United States 717 683 Other Countries 595 691 $ 81,439 $ 88,217 The following is a summary of revenue by product type: Three Months Ended September 30, 2015 2014 (in thousands) Power discrete $ 59,912 $ 64,891 Power IC 17,514 19,156 Packaging and testing services 4,013 4,170 $ 81,439 $ 88,217 Long-lived assets, net consisting of property, plant and equipment, by geographical area are as follows: September 30, June 30, (in thousands) China $ 70,774 $ 71,618 United States 46,214 47,439 Other Countries 443 522 $ 117,431 $ 119,579

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Purchase Commitments As of September 30, 2015 and June 30, 2015 , the Company had approximately $28.2 million and $29.2 million , respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services, and approximately $0.7 million and $3.7 million , respectively, of capital commitments for the purchase of property and equipment. Contingencies and Indemnities The Company is currently not a party to any pending material legal proceedings. 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 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 September 30, 2015 and June 30, 2015 . 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.

The Company and Significant A15

The Company and Significant Accounting Policies (Policies)	3 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Concentration Risk, Credit Risk, Policy [Policy Text Block]	The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application 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 bad debt 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.
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, 2015 . 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 period presented have been included in the interim periods. Operating results for the three months ended September 30, 2015 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2016 . The condensed consolidated balance sheet at June 30, 2015 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, 2015 .
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, 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 are 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 In July 2015, the FASB issued No. 2015-11, Inventory - Simplifying the Measurement of Inventory("ASU 2015-11"). ASU 2015-11 is additional guidance regarding the subsequent measurement of inventory by requiring inventory to be measured at the lower of cost and net realizable value. This guidance is effective for fiscal years and interim periods beginning after December 15, 2016. Early adoption is permitted. 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 May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers(“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In July 2015, the FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. In August 2015 the FASB issued ASU 2015-14, Revenue from Contracts with customers - Deferral of the Effective Date", that defers by one year the effective date of ASU 2014-09. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements. In August 2014, the FASB issued amended standards No. 2014-15, Presentation of Financial Statements - Going Concern ('ASU 2014-15"), to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures requirement. The amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation for each annual and interim reporting period, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early adoption is permitted. 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 February 2015, the FASB issued ASU No. 2015-2, “Consolidation (Topic 820): Amendments to the Consolidation Analysis.” ASU 2015-2 provides a revised consolidation model for all reporting entities to use in evaluating whether they should consolidate certain legal entities. All legal entities will be subject to reevaluation under this revised consolidation model. The revised consolidation model, among other things, (i) modifies the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities, (ii) eliminates the presumption that a general partner should consolidate a limited partnership, and (iii) modifies the consolidation analysis of reporting entities that are involved with VIEs through fee arrangements and related party relationships. ASU 2015-2 is effective for fiscal years, and interim reporting periods within those fiscal years, beginning after December 15, 2015. 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 April 2015, the FASB issued ASU No. 2015-03, Interest -Imputation of Interest(Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts and the accounting for debt issue costs under IFRS. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. ASU 2015-03 is effective for the annual period ending after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments in this Update is permitted for financial statements that have not been previously issued. 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.

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Sep. 30, 2015
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: Three Months Ended September 30, 2015 2014 (in thousands, except per share data) Numerator: Net income (loss) $ (1,975 ) $ 564 Denominator: Basic: Weighted average number of common shares used to compute basic net income (loss) per share 22,698 26,385 Diluted: Weighted average number of common shares used to compute basic net income (loss) per share 22,698 26,385 Effect of potentially dilutive securities: Stock options, RSUs and ESPP shares — 618 Weighted average number of common shares used to compute diluted net income (loss) per share 22,698 27,003 Net income (loss) per share: Basic $ (0.09 ) $ 0.02 Diluted $ (0.09 ) $ 0.02
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 (loss) per share as their effect would have been anti-dilutive: Three Months Ended September 30, 2015 2014 (in thousands) Employee stock options and RSUs 3,617 2,393 ESPP to purchase common shares 188 — Total potential dilutive securities 3,805 2,393

Concentration of Credit Risk 17

Concentration of Credit Risk and Significant Customers (Tables)	3 Months Ended
	Sep. 30, 2015
Risks and Uncertainties [Abstract]
Schedules of Concentration of Risk, by Risk Factor	Summarized below are individual customers whose revenue or accounts receivable balances were 10% or higher than the respective total consolidated amounts: Three Months Ended September 30, Percentage of revenue 2015 2014 Customer A 23.1 % 24.1 % Customer B 36.0 % 39.6 % Customer C 14.3 % 12.9 % September 30, June 30, Percentage of accounts receivable Customer A 19.4 % 29.4 % Customer B 27.3 % 27.7 % Customer C 25.4 % 14.7 %

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Sep. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	Accounts receivable: September 30, June 30, (in thousands) Accounts receivable $ 54,630 $ 58,249 Less: Allowance for price adjustments (17,402 ) (19,438 ) Less: Allowance for doubtful accounts (30 ) (30 ) Accounts receivable, net $ 37,198 $ 38,781
Schedule of Inventory, Current	Inventories: September 30, June 30, (in thousands) Raw materials $ 20,242 $ 19,423 Work in-process 31,586 31,269 Finished goods 10,130 13,483 $ 61,958 $ 64,175
Property, Plant and Equipment	Property, plant and equipment, net: September 30, June 30, (in thousands) Land $ 4,877 $ 4,877 Building 4,243 4,243 Manufacturing machinery and equipment 183,888 172,467 Equipment and tooling 11,821 11,261 Computer equipment and software 20,739 20,602 Office furniture and equipment 1,798 1,762 Leasehold improvements 27,842 27,568 255,208 242,780 Less: Accumulated depreciation (148,628 ) (141,883 ) 106,580 100,897 Equipment and construction in progress 10,851 18,682 Property, plant and equipment, net $ 117,431 $ 119,579
Schedule of Other Assets, Noncurrent	Other long-term assets: September 30, June 30, (in thousands) Prepayments for property and equipment $ 76 $ 692 Investment in a privately held company 100 100 Office leases deposits 1,343 1,215 Other 3 4 $ 1,522 $ 2,011
Schedule of Accrued Liabilities	Accrued liabilities: September 30, June 30, (in thousands) Accrued compensation and benefit $ 6,419 $ 5,600 Accrued vacation 1,828 1,830 Accrued bonuses 1,120 1,152 Warranty accrual 2,203 1,957 Stock rotation accrual 1,910 1,894 Accrued professional fees 1,420 1,402 ESPP payable 827 343 Customer deposits 611 149 Accrued inventory 699 697 Accrued facilities related expenses 1,389 1,367 Other accrued expenses 2,799 2,834 $ 21,225 $ 19,225
Schedule of Product Warranty Liability	The activities in the warranty accrual, included in accrued liabilities, are as follows: Three Months Ended September 30, 2015 2014 (in thousands) Beginning balance $ 1,957 $ 1,346 Additions 305 530 Utilization (59 ) (646 ) Ending balance $ 2,203 $ 1,230
Stock Rotation Accrual	The activities in the stock rotation accrual, included in accrued liabilities, are as follows: Three Months Ended September 30, 2015 2014 (in thousands) Beginning balance $ 1,894 $ 1,645 Additions 1,510 1,294 Utilization (1,494 ) (1,332 ) Ending balance $ 1,910 $ 1,607
Schedule of Other Noncurrent Liabilities	Other Long-term liabilities: September 30, June 30, (in thousands) Deferred rent $ 902 $ 953

Shareholders' Equity and Shar19

Shareholders' Equity and Share-based Compensation (Tables)	3 Months Ended
	Sep. 30, 2015
Share-based Compensation [Abstract]
Summary of Stock Option Activities	Stock Options The following table summarizes the Company's stock option activities for the three months ended September 30, 2015 : Weighted Average Number of Exercise Price Aggregate Shares Per Share Intrinsic Value Outstanding at June 30, 2015 2,836,217 $ 10.77 $ 1,410,538 Granted — $ — Exercised (78,453 ) $ 5.41 $ 219,159 Canceled or forfeited (81,283 ) $ 7.98 Outstanding at September 30, 2015 2,676,481 $ 11.01 $ 284,049 Information with respect to stock options outstanding and exercisable at September 30, 2015 is as follows: Options Outstanding Options Vested and Exercisable Number Outstanding Weighted-Average Weighted-Average Number Exercisable Weighted-Average Total options outstanding 2,676,481 4.33 $ 11.01 2,256,226 $ 11.59 Options vested and expected to vest 2,636,712 4.27 $ 11.06 Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	The fair value of stock options granted were estimated at the date of grant using the Black-Scholes option valuation model for the three months ended September 30, 2015 with the following weighted average assumptions: Three Months Ended September 30, 2015 Volatility rate 40.13% Risk-free interest rate 1.7% Expected term 5.5 years Dividend yield 0%
Restricted Stock Units Activity	Restricted Stock Units ("RSU") The following table summarizes the Company's RSU activities for the three months ended September 30, 2015 : Number of Restricted Stock Units Weighted Average Grant Date Fair Value Per Share Weighted Average Remaining Recognition Period (Years) Aggregate Intrinsic Value Nonvested at June 30, 2015 873,946 $ 8.64 1.77 $ 7,638,288 Granted 49,690 $ 7.76 Vested (24,682 ) $ 9.32 Forfeited (53,480 ) $ 8.67 Nonvested at September 30, 2015 845,474 $ 8.57 1.60 $ 6,586,242 RSUs vested and expected to vest 732,498 1.50 $ 5,706,155 The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	Employee Share Purchase Plan ("ESPP") The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows: Three Months Ended September 30, 2015 Volatility rate 31.4% Risk-free interest rate 0.1% - 0.6% 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 related to stock options, ESPP and RSUs described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows: Three Months Ended September 30, 2015 2014 (in thousands) Cost of goods sold $ 131 $ 154 Research and development 193 206 Selling, general and administrative 465 742 $ 789 $ 1,102

Segment and Geographic Inform20

Segment and Geographic Information (Tables)	3 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Long-lived assets, net consisting of property, plant and equipment, by geographical area are as follows: September 30, June 30, (in thousands) China $ 70,774 $ 71,618 United States 46,214 47,439 Other Countries 443 522 $ 117,431 $ 119,579 The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to: Three Months Ended September 30, 2015 2014 (in thousands) Hong Kong $ 70,453 $ 75,247 China 9,016 10,957 South Korea 658 639 United States 717 683 Other Countries 595 691 $ 81,439 $ 88,217
Revenue from External Customers by Products and Services	The following is a summary of revenue by product type: Three Months Ended September 30, 2015 2014 (in thousands) Power discrete $ 59,912 $ 64,891 Power IC 17,514 19,156 Packaging and testing services 4,013 4,170 $ 81,439 $ 88,217

Net Income (Loss) Per Share - B

Net Income (Loss) Per Share - Basic and Diluted Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net income (loss)	$ (1,975)	$ 564
Basic:
Weighted average number of common shares used to compute basic net income (loss) per share	22,698	26,385
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	0	618
Effect of potentially dilutive securities:
Weighted average number of common shares used to compute diluted net income (loss) per share	22,698	27,003
Net income (loss) per share:
Basic (in dollars per share)	$ (0.09)	$ 0.02
Diluted (in dollars per share)	$ (0.09)	$ 0.02

Net Income (Loss) Per Share - P

Net Income (Loss) Per Share - Potential Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	3,805	2,393
Employee stock options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	3,617	2,393
ESPP to purchase common shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	188	0

Concentration of Credit Risk 23

Concentration of Credit Risk and Significant Customers - (Details)	3 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014
Minimum [Member]
Concentration Risk
Terms of credit sales, (in days)	30 days
Maximum [Member]
Concentration Risk
Terms of credit sales, (in days)	60 days
Customer A | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	23.10%		24.10%
Customer A | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	19.40%	29.40%
Customer B | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	36.00%		39.60%
Customer B | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	27.30%	27.70%
Customer C | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	14.30%		12.90%
Customer C | Accounts Receivable | Customer Concentration Risk
Concentration Risk
Customers greater than 10% of total	25.40%	14.70%

Balance Sheet Components - Acco

Balance Sheet Components - Accounts receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Accounts receivable	$ 54,630	$ 58,249
Less: Allowance for price adjustments	(17,402)	(19,438)
Less: Allowance for doubtful accounts	(30)	(30)
Accounts receivable, net	$ 37,198	$ 38,781

Balance Sheet Components - Inve

Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 20,242	$ 19,423
Work in-process	31,586	31,269
Finished goods	10,130	13,483
Inventory, net	$ 61,958	$ 64,175

Balance Sheet Components - Prop

Balance Sheet Components - Property, plant, and equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 255,208	$ 242,780
Less: Accumulated depreciation	(148,628)	(141,883)
Property, plant and equipment excluding equipment and construction in progress, net	106,580	100,897
Equipment and construction in progress	10,851	18,682
Property, plant and equipment, net	117,431	119,579
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	4,243	4,243
Manufacturing machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	183,888	172,467
Equipment and tooling
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	11,821	11,261
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	20,739	20,602
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	1,798	1,762
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment excluding equipment and construction In progress, gross	$ 27,842	$ 27,568

Balance Sheet Components - Othe

Balance Sheet Components - Other long term assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Prepayments for property and equipment	$ 76	$ 692
Investment in a privately held company	100	100
Office leases deposits	1,343	1,215
Other Assets, Miscellaneous, Noncurrent	3	4
Other long-term assets	$ 1,522	$ 2,011

Balance Sheet Components - Accr

Balance Sheet Components - Accrued liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Jun. 30, 2014
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and benefit	$ 6,419	$ 5,600
Accrued vacation	1,828	1,830
Accrued bonuses	1,120	1,152
Warranty accrual	2,203	1,957	$ 1,230	$ 1,346
Stock rotation accrual	1,910	1,894	$ 1,607	$ 1,645
Accrued professional fees	1,420	1,402
ESPP payable	827	343
Customer deposits	611	149
Accrued inventory	699	697
Accrued facilities related expenses	1,389	1,367
Other accrued expenses	2,799	2,834
Accrued liabilities	$ 21,225	$ 19,225

Balance Sheet Components - Prod

Balance Sheet Components - Product Warranty Accrual (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balance	$ 1,957	$ 1,346
Additions	305	530
Utilization	(59)	(646)
Ending balance	$ 2,203	$ 1,230

Balance Sheet Components - Ot30

Balance Sheet Components - Other Long Term Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Deferred rent	$ 902	$ 953
Other long term liabilities	$ 902	$ 953

Balance Sheet Components - Stoc

Balance Sheet Components - Stock Rotation Accrual (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Stock Rotation Accrual Increae (Decrease) [Roll Forward]
Beginning balance	$ 1,894	$ 1,645
Additions	1,510	1,294
Utilization	(1,494)	(1,332)
Ending balance	$ 1,910	$ 1,607

Shareholders' Equity and Shar32

Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 07, 2015	Sep. 30, 2015	Sep. 30, 2015	Jul. 08, 2015	Jun. 30, 2015	Jun. 07, 2015	Apr. 30, 2015	Mar. 31, 2015	May. 08, 2014	Oct. 22, 2010
Class of Stock [Line Items]
Share repurchase program, authorized amount (USD in Millions)										$ 25
Shares Repurchase Program Remaining Balance				$ 18.2			$ 50	$ 17.8	$ 22.7
Treasury stock acquired, shares repurchased (in shares)		3,930,106	4,957,700
Treasury Stock, Value, Acquired, Cost Method		$ 35	$ 44
Treasury stock acquired, average price per share (in dollars per share)		$ 8.90	$ 8.87
Treasury stock, Acquired, Fees and related expenses		$ 0.3
Treasury Stock, Shares, Retired			0
Treasury Stock Reissued, Average Price Per Share			$ 2.19
Treasury Stock Reissued
Class of Stock [Line Items]
Treasury stock acquired, average price per share (in dollars per share)			$ 13.84
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)			29,675
Dutch Auction Tender Offer [Member] | Common Stock [Member]
Class of Stock [Line Items]
Share repurchase program, authorized amount (USD in Millions)						$ 30
Treasury stock acquired, shares repurchased (in shares)	3,296,703
Treasury Stock, Value, Acquired, Cost Method	$ 30
Treasury Stock, Shares, Acquired, Represent Percentage Of The Company's Common Shares Issued And Outstanding					12.53%
Treasury stock acquired, average price per share (in dollars per share)	$ 9.10
Dutch Auction Tender Offer [Member] | Minimum [Member] | Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Cost Per Share						$ 8.50
Dutch Auction Tender Offer [Member] | Maximum [Member] | Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Cost Per Share						$ 9.20

Shareholders' Equity and Shar33

Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) - USD ($)	3 Months Ended
	Sep. 30, 2015	Jun. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at June 30, 2015 (in shares)	2,836,217
Granted (in shares)	0
Exercised (in shares)	(78,453)
Canceled or forfeited (in shares)	(81,283)
Outstanding at September 30, 2015 (in shares)	2,676,481
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at June 30, 2015 (in dollars per share)	$ 10.77
Granted (in dollars per share)	0
Exercised (in dollars per share)	5.41
Canceled or forfeited (in dollars per share)	7.98
Outstanding at September 30, 2015 (in dollars per share)	$ 11.01
Options Outstanding Aggregate Intrinsic Value	$ 284,049	$ 1,410,538
Options Exercised Aggregate Intrinsic Value	$ 219,159
Employee Share Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility Rate	31.40%
Expected Term	1 year 3 months 18 days
Expected Dividend Rate	0.00%
Employee Share Purchase Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate	0.10%
Employee Share Purchase Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk Free Interest Rate	0.60%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility Rate	40.13%
Risk Free Interest Rate	1.70%
Expected Term	5 years 6 months
Expected Dividend Rate	0.00%

Shareholders' Equity and Shar34

Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) - $ / shares	3 Months Ended
	Sep. 30, 2015	Jun. 30, 2015
Share-based Compensation [Abstract]
Options, Number Outstanding (in shares)	2,676,481	2,836,217
Options, Weighted-Average Remaining Contractual Life (in years)	4 years 3 months 29 days
Options, Weighted-Average Exercise Price (in dollars per share)	$ 11.01	$ 10.77
Options, Number Exercisable (in shares)	2,256,226
Options, Weighted-Average Exercise Price (in dollars per share)	$ 11.59
Options vested and expected to vest, Number Outstanding (in shares)	2,636,712
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	4 years 3 months 7 days
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$ 11.06

Shareholders' Equity and Shar35

Shareholders' Equity and Share-based Compensation - Restricted Stock Activity (Details) - USD ($)	3 Months Ended
	Sep. 30, 2015	Jun. 30, 2015
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 (Years)	1 year 6 months 4 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, 2015	873,946
Granted	49,690
Vested	(24,682)
Forfeited	(53,480)
Nonvested at September 30, 2015	845,474	873,946
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, 2015	$ 8.64
Granted	7.76
Vested	9.32
Forfeited	8.67
Nonvested at September 30, 2015	$ 8.57	$ 8.64
Weighted Average Remaining Recognition Period (Years)	1 year 7 months 6 days	1 year 9 months 7 days
RSUs Nonvested Aggregate Intrinsic Value	$ 6,586,242	$ 7,638,288
RSUs vested and expected to vest, Outstanding (in shares)	732,498
RSUs vested and expected to vest, Weighted Average Remaining Recognition Period (in years)	1 year 6 months
RSUs vested and expected to vest, Aggregate Intrinsic Value	$ 5,706,155

Shareholders' Equity and Shar36

Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 789	$ 1,102
Unrecognized compensation expense	$ 4,000
Recognition period of share-based compensation expense (in years)	1 year 6 months 4 days
Cost of goods sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 131	154
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	193	206
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation expense	$ 465	$ 742

Income Taxes - Narrative (Deta

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 1,214	$ 1,171
Estimated effective income tax rate	(159.50%)	67.50%
Unrecognized tax benefits	$ 6,400
Unrecognized tax benefit that would impact effective tax rate	$ 4,300

Segment and Geographic Inform38

Segment and Geographic Information - Revenue by Location and Product Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 81,439	$ 88,217
Power discrete
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	59,912	64,891
Power IC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	17,514	19,156
Packaging and testing services
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,013	4,170
Hong Kong
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	70,453	75,247
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	9,016	10,957
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	658	639
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	717	683
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 595	$ 691

Segment and Geographic Inform39

Segment and Geographic Information - Long-lived Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 117,431	$ 119,579
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	70,774	71,618
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	46,214	47,439
Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Property, plant and equipment, net	$ 443	$ 522

Segment and Geographic Inform40

Segment and Geographic Information - Narratives (Details)	3 Months Ended
	Sep. 30, 2015Segment
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	Sep. 30, 2015	Jun. 30, 2015
Raw materials, wafers, and packaging and testing services puchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 28.2	$ 29.2
Property and equipment purchase commitments
Purchase Commitment, Excluding Long-term Committment [Line Items]
Purchase commitment, amount	$ 0.7	$ 3.7

Commitments and Contingencies42

Commitments and Contingencies - Guarantees (Details) - USD ($)	Sep. 30, 2015	Jun. 30, 2015
Indemnification Agreement
Loss Contingencies [Line Items]
Indemnifications accrual	$ 0	$ 0