ALPHA & OMEGA SEMICONDUCTOR LTD, 10-Q filed on 2/7/2014
Quarterly Report
Document and Entity Information
6 Months Ended
Dec. 31, 2013
Jan. 31, 2014
Entity Information [Line Items]
 
 
Entity Registrant Name
ALPHA & OMEGA SEMICONDUCTOR Ltd 
 
Entity Central Index Key
0001387467 
 
Current Fiscal Year End Date
--06-30 
 
Entity Filer Category
Accelerated Filer 
 
Document Type
10-Q 
 
Document Period End Date
Dec. 31, 2013 
 
Document Fiscal Year Focus
2014 
 
Document Fiscal Period Focus
Q2 
 
Amendment Flag
false 
 
Entity Common Stock, Shares Outstanding
 
25,994,027 
CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Current assets:
 
 
Cash and cash equivalents
$ 102,533 
$ 92,406 
Restricted cash
206 
204 
Accounts receivable, net
39,002 
38,298 
Inventories
62,767 
68,339 
Deferred income tax assets
2,191 
3,030 
Other current assets
3,376 
3,578 
Total current assets
210,075 
205,855 
Property, plant and equipment, net
127,508 
138,111 
Intangible assets, net
296 
496 
Goodwill
269 
269 
Deferred income tax assets
10,766 
10,823 
Other long-term assets
1,261 
767 
Total assets
350,175 
356,321 
Current liabilities:
 
 
Short term debt
3,107 
3,821 
Accounts payable
25,779 
31,738 
Accrued liabilities
15,372 
14,571 
Income taxes payable
1,506 
1,472 
Deferred margin
611 
622 
Capital leases
695 
1,267 
Total current liabilities
47,070 
53,491 
Long-term debt
12,143 
13,571 
Income taxes payable - long term
3,371 
3,692 
Deferred income tax liabilities
2,214 
2,613 
Capital leases - long term
100 
195 
Deferred rent
1,227 
1,308 
Total liabilities
66,125 
74,870 
Commitments and contingencies (Note 9)
   
   
Preferred shares, par value $0.002 per share:
 
 
Authorized: 10,000 shares: Issued and outstanding: none at December 31, 2013 and June 30, 2013
0 
0 
Common shares, par value $0.002 per share:
 
 
Authorized: 50,000 shares: Issued and outstanding: 26,178 shares and 25,955 shares at December 31, 2013 and 25,882 shares and 25,656 shares at June 30, 2013
52 
51 
Treasury shares at cost: 223 shares at December 31, 2013 and 226 shares at June 30, 2013
(2,013)
(2,054)
Additional paid-in capital
170,434 
168,352 
Accumulated other comprehensive income
1,006 
957 
Retained earnings
114,571 
114,145 
Total shareholders’ equity
284,050 
281,451 
Total liabilities and shareholders’ equity
$ 350,175 
$ 356,321 
CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
Dec. 31, 2013
Jun. 30, 2013
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)
26,178,000 
25,882,000 
Common stock, shares outstanding (in shares)
25,955,000 
25,656,000 
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)
223,000 
226,000 
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Revenue
$ 76,265 
$ 89,448 
$ 160,386 
$ 185,209 
Cost of goods sold
62,646 
68,854 
129,616 
139,082 
Gross profit
13,619 
20,594 
30,770 
46,127 
Operating expenses
 
 
 
 
Research and development
4,972 
6,866 
11,819 
13,799 
Selling, general and administrative
7,309 
8,838 
16,249 
17,619 
Total operating expenses
12,281 
15,704 
28,068 
31,418 
Operating income
1,338 
4,890 
2,702 
14,709 
Interest income
14 
20 
38 
37 
Interest expense
(69)
(107)
(148)
(189)
Income before income taxes
1,283 
4,803 
2,592 
14,557 
Income tax expense
1,123 
1,085 
2,125 
2,897 
Net income
$ 160 
$ 3,718 
$ 467 
$ 11,660 
Net income per share
 
 
 
 
Basic (in dollars per share)
$ 0.01 
$ 0.15 
$ 0.02 
$ 0.46 
Diluted (in dollars per share)
$ 0.01 
$ 0.14 
$ 0.02 
$ 0.45 
Weighted average number of common shares used to compute net income per share
 
 
 
 
Basic (in shares)
25,846 
25,292 
25,765 
25,165 
Diluted (in shares)
26,462 
26,101 
26,385 
25,992 
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Net income
$ 160 
$ 3,718 
$ 467 
$ 11,660 
Other comprehensive income, net of tax
 
 
 
 
Foreign currency translation adjustment
(5)
25 
49 
55 
Total comprehensive income
$ 155 
$ 3,743 
$ 516 
$ 11,715 
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)
In Thousands, unless otherwise specified
6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Cash flows from operating activities
 
 
Net income
$ 467 
$ 11,660 
Adjustments to reconcile net income to net cash provided by operating activities:
 
 
Depreciation
13,748 
14,498 
Amortization
200 
286 
Share-based compensation expense
1,314 
2,354 
Deferred income taxes, net
497 
624 
(Gain) loss on disposal of property and equipment
(120)
51 
Changes in working capital:
 
 
Accounts receivable
(704)
(4,117)
Inventories
5,572 
(5,710)
Other current and long-term assets
(292)
1,850 
Accounts payable
(5,961)
2,496 
Income taxes payable
(287)
218 
Accrued and other liabilities
607 
(1,542)
Net cash provided by operating activities
15,041 
22,668 
Cash flows from investing activities
 
 
Purchases of property and equipment
(3,282)
(12,531)
Proceeds from sale of property and equipment
244 
0 
Restricted cash placed
(2)
(125)
Net cash used in investing activities
(3,040)
(12,656)
Cash flows from financing activities
 
 
Proceeds from exercise of stock options and ESPP
930 
2,051 
Payment for repurchase of common shares
0 
(5)
Proceeds from borrowings
0 
250 
Repayments of borrowings
(2,143)
(2,143)
Principal payments on capital leases
(667)
(479)
Net cash used in financing activities
(1,880)
(326)
Effect of exchange rate changes on cash and cash equivalents
6 
12 
Net increase in cash and cash equivalents
10,127 
9,698 
Cash and cash equivalents at beginning of period
92,406 
82,166 
Cash and cash equivalents at end of period
102,533 
91,864 
Supplemental disclosures of non-cash investing information:
 
 
Property and equipment purchased but not yet paid
$ 1,808 
$ 3,144 
The Company and Significant Accounting Policies
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 portable 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, Macau, 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, 2013. 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 and six months ended December 31, 2013 are not necessarily indicative of the results that may be expected for other interim periods or the fiscal year ending June 30, 2014. The condensed consolidated balance sheet at June 30, 2013 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, 2013.
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, variable interest entities, 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
Comprehensive income 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 consists of cumulative foreign currency translation adjustments. Total comprehensive income is presented in the condensed consolidated statements of comprehensive income.
Recent Accounting Pronouncements
In July 2013, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update ("ASU") 2013-11, Income Taxes (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The new guidance requires the netting of unrecognized tax benefits ("UTBs") against a deferred tax asset for a loss or other carryforward that would apply in settlement of the uncertain tax positions. Under the new standard, UTBs will be netted against all available same-jurisdiction loss or other tax carryforwards that would be utilized, rather than only against carryforwards that are created by the UTBs. The ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. The ASU should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The Company does not expect the adoption of this guidance to have any significant impact on the Company's condensed consolidated financial statements.
Net Income Per Share
Net Income Per Share
Net Income Per Share
The following table presents the calculation of basic and diluted net income per share:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands, except per share data)
Numerator:
 
 
 
 
 
 
 
Net income
$
160

 
$
3,718

 
$
467

 
$
11,660

 
 
 
 
 
 
 
 
Denominator:
 
 
 
 
 
 
 
Basic:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income per share
25,846

 
25,292

 
25,765

 
25,165

Diluted:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income per share
25,846

 
25,292

 
25,765

 
25,165

Effect of potentially dilutive securities:
 
 
 
 
 
 
 
Stock options, RSUs and ESPP shares
616

 
809

 
620

 
827

Weighted average number of common shares used to compute diluted net income per share
26,462

 
26,101

 
26,385

 
25,992

Net income per share:
 
 
 
 
 
 
 
Basic
$
0.01

 
$
0.15

 
$
0.02

 
$
0.46

Diluted
$
0.01

 
$
0.14

 
$
0.02

 
$
0.45


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,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
Employee stock options and RSUs
2,700

 
2,841

 
2,742

 
2,768

ESPP to purchase common shares
302

 
187

 
304

 
251

Total potential dilutive securities
3,002

 
3,028

 
3,046

 
3,019

Concentration of Credit Risk and Significant Customers
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 financial assets 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 December 31,
 
Six Months Ended December 31,
Percentage of revenue
2013
 
2012
 
2013
 
2012
Customer A
22.7
%
 
24.2
%
 
21.6
%
 
23.9
%
Customer B
42.2
%
 
43.8
%
 
43.3
%
 
42.6
%
Customer C
13.0
%
 
11.2
%
 
12.4
%
 
12.5
%
 
December 31,
2013
 
June 30,
2013
Percentage of accounts receivable
 
Customer A
20.4
%
 
33.8
%
Customer B
35.9
%
 
22.6
%
Customer C
17.0
%
 
19.9
%
Balance Sheet Components
Balance Sheet Components
Balance Sheet Components
Accounts receivable:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Accounts receivable
$
54,099

 
$
52,202

Less: Allowance for price adjustments
(15,067
)
 
(13,152
)
Less: Allowance for doubtful accounts
(30
)
 
(752
)
Accounts receivable, net
$
39,002

 
$
38,298



Inventories:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Raw materials
$
17,445

 
$
17,248

Work in-process
36,165

 
38,618

Finished goods
9,157

 
12,473

 
$
62,767

 
$
68,339


 

Property, plant and equipment:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Land
$
4,950

 
$
4,950

Building
4,106

 
4,106

Manufacturing machinery and equipment
159,338

 
156,958

Equipment and tooling
10,413

 
10,356

Computer equipment and software
16,835

 
16,140

Office furniture and equipment
1,564

 
1,559

Leasehold improvements
24,434

 
24,068

 
221,640

 
218,137

Less accumulated depreciation
(100,932
)
 
(87,180
)
 
120,708

 
130,957

Equipment and construction in progress
6,800

 
7,154

Property, plant and equipment, net
$
127,508

 
$
138,111


Other long term assets:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Prepayments for property and equipment
$
707

 
$
77

Investment in a privately held company
100

 
100

Deferred debt issuance cost
43

 
91

Office leases deposits
411

 
499

 
$
1,261

 
$
767


Accrued liabilities:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Accrued salaries and wages
$
4,216

 
$
3,079

Accrued vacation
968

 
2,078

Accrued bonuses
1,153

 
880

Warranty accrual
1,496

 
1,428

Stock rotation accrual
1,480

 
1,572

Accrued professional fees
607

 
918

ESPP payable
290

 
353

Customer deposits
488

 
123

Other accrued expenses
4,674

 
4,140

 
$
15,372

 
$
14,571




The activities in the warranty accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2013
 
2012
 
(in thousands)
Beginning balance
$
1,428

 
$
1,556

Additions
1,239

 
733

Utilization
(1,171
)
 
(616
)
Ending balance
$
1,496

 
$
1,673


The activities in the stock rotation accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2013
 
2012
 
(in thousands)
Beginning balance
$
1,572

 
$
2,032

Additions
2,332

 
3,254

Utilization
(2,424
)
 
(3,519
)
Ending balance
$
1,480

 
$
1,767

Debt
Debt
Debt
On May 11, 2012, the Company entered into a loan agreement with a financial institution that provides a term loan of $20.0 million for general purposes and a $10.0 million non-revolving credit line for the purchase of equipment. Both the term loan and equipment line will be fully repayable in May 2015. The borrowings may be made in the form of either Eurodollar loans or Base Rate loans. Eurodollar loans accrue interest based on an adjusted London Interbank Offered Rate ("LIBOR") as defined in the agreement, plus a margin of 1.00% to 1.75%. Base Rate loans accrue interest at the highest of (a) the lender's Prime Rate, (b) the Federal Funds Rate plus 0.5% and (c) the Eurodollar Rate (for a one-month interest period) plus 1%; plus a margin of -0.5% to 0.25%. The applicable margins for both Eurodollar loans and Base Rate loans will vary from time to time in the foregoing ranges based on the cash and cash equivalent balances maintained by the Company and its subsidiaries with the lender. In May 2013, the equipment credit line expired and there was no outstanding balance. As of December 31, 2013 and June 30, 2013, the outstanding balances of the term loan were $15.0 million and $17.1 million, respectively. Of the $15.0 million and $17.1 million term loan, $2.9 million and $3.6 million were included as short-term debt as of December 31, 2013 and June 30, 2013, respectively.

The obligations under the term loan are secured by substantially all assets of two subsidiaries of the Company, including, but not limited to, certain real property and related assets located at the Oregon fab. In addition, the Company and certain subsidiaries of the Company have agreed to guarantee full repayment and performance of the obligations under the loan agreement. 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 including total liabilities to tangible net worth, fixed charge coverage and current assets to current liabilities. As of December 31, 2013, the Company was in compliance with these covenants.
Two of the Company's subsidiaries in China had revolving lines of credit that allow each of the subsidiaries to draw down, from time to time, up to 80% of the accounts receivable balance of such subsidiary, with an aggregated maximum amount of RMB 95 million (equivalent of $15.7 million based on the currency exchange rate as of December 31, 2013) to finance the subsidiary's working capital with a maximum of 120-day repayment term. The interest rate on each draw down varies and is indexed to the published LIBOR. The lines expired in September 2013 and the Company is currently in the process of renewing them. As of December 31, 2013, there was no outstanding balance under these two revolving lines of credit.
During July 2012, the Company entered into a loan agreement with the State of Oregon for an amount of $250,000. The loan is required to be used for training new and re-training existing employees of the Oregon Fab. The loan bears a compound annual interest rate of 5.0% and is to be repaid in April 2014. The State may forgive the loan and unpaid interest if certain conditions primarily relating to hiring targets are met and it is more likely than not that the Company will meet those hiring targets. As of December 31, 2013 and June 30, 2013, the outstanding balance and accrued interest of the loan, included in short term debt, was $269,000 and $262,000, respectively.
Shareholders' Equity and Share-based Compensation
Shareholders' Equity and Share-based Compensation
Shareholders' Equity and Share-based Compensation
Share Repurchase
On October 22, 2010, the Company's board of directors authorized a $25.0 million share repurchase program. Under this repurchase program the Company may, from time to time, repurchase shares from the open market or in privately negotiated transactions, subject to supervision and oversight by the board. 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.
During the three and six months ended December 31, 2013, the Company did not repurchased any shares under the program. During the three and six months ended December 31, 2013, the Company reissued 2,700 and 2,950 shares, respectively, with weighted average repurchase cost of $13.82 per share for both periods, upon vesting of certain restricted stock units ("RSU").
As of December 31, 2013, the Company repurchased an aggregate of 241,770 shares for a total cost of $2.3 million, at an average repurchase price of $9.40 per share since inception of the program. Of the 241,770 repurchased shares, 18,750 shares with a weighted average repurchase price of $13.81 per share were reissued at an average price of $3.47 per share for option exercises and vested RSUs.
Stock Options
The following table summarizes the Company's stock option activities for the six months ended December 31, 2013:
 
 
 
Weighted
 
 
 
 
 
Average
 
 
 
Number of
 
Exercise Price
 
Aggregate
 
Shares
 
Per Share
 
Intrinsic Value
Outstanding at June 30, 2013
3,593,854

 
$
10.24

 
$
3,144,506

Granted
77,500

 
7.51

 
 
Exercised
(119,321
)
 
0.98

 
772,342

Canceled or forfeited
(237,461
)
 
11.18

 
 
Outstanding at December 31, 2013
3,314,572

 
$
10.45

 
$
2,409,612


Information with respect to stock options outstanding and exercisable at December 31, 2013 is as follows:
 
Options Outstanding  
 
Options Vested and Exercisable  
 
Number Outstanding
 
Weighted-Average
Remaining Contractual Life (years) 
 
Weighted-Average
Exercise Price
 
Number Exercisable
 
Weighted-Average
Exercise Price
Total options outstanding
3,314,572

 
4.43
 
$
10.45

 
2,778,724

 
$
10.29

Options vested and expected to vest
3,280,477

 
4.36
 
$
10.44

 
 
 
 
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 six months ended December 31, 2013 with the following weighted average assumptions:
 
Six Months Ended December 31,
 
2013
Volatility rate
48%
Risk-free interest rate
1.6% - 1.7%
Expected term
5.5 years
Dividend yield
0%

Restricted Stock Units ("RSU")
The following table summarizes the Company's RSU activities for the six months ended December 31, 2013:
 
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, 2013
549,553

 
$
9.50

 
1.87
 
$
4,198,585

Granted
55,804

 
7.65

 
 
 
 
Vested
(71,960
)
 
9.65

 
 
 
 
Forfeited
(73,952
)
 
9.72

 
 
 
 
Nonvested at December 31, 2013
459,445

 
$
9.22

 
1.67
 
$
3,542,321

RSUs vested and expected to vest
415,616

 
 
 
1.60
 
$
3,204,396

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
The Employee Share Purchase Plan (the "ESPP") was established in May 2010 upon the completion of the Company's initial public offering. The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows:
 
Six Months Ended December 31,
 
2013
Volatility rate
50%
Risk-free interest rate
0.1% - 0.3%
Expected term
1.3 years
Dividend yield
0%

Share-based Compensation Expense
The total share-based compensation expense (reversal) 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 December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
 
(in thousands)
Cost of goods sold
$
142

 
$
141

 
$
338

 
$
339

Research and development
(32
)
 
278

 
263

 
671

Selling, general and administrative
(5
)
 
494

 
713

 
1,344

 
$
105

 
$
913

 
$
1,314

 
$
2,354


Total unrecognized stock-based compensation expense as of December 31, 2013 was $3.8 million, which includes estimated forfeitures and is expected to be recognized over a weighted-average period of 1.3 years.
Income Taxes
Income Taxes
Income Taxes
The Company recognized income tax expense of approximately $1.1 million for both the three months ended December 31, 2013 and 2012. The Company recognized income tax expense of approximately $2.1 million and $2.9 million for the six months ended December 31, 2013 and 2012, respectively. The estimated effective tax rate was 87.5% and 22.6% for the three months ended December 31, 2013 and 2012, respectively. The estimated effective tax rate was 82.0% and 19.9% for the six months ended December 31, 2013 and 2012, respectively. The effective tax rate for the three and the six months ended December 31, 2013 was higher than that for same period of last year primarily due to the changes in the mix of earnings in various geographic jurisdictions between the two periods.
The Company files its income tax returns in the United States and in various foreign jurisdictions. The tax years 2001 to 2013 remain open to examination by U.S. federal and state tax authorities. The tax years 2005 to 2013 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, 2013, the gross amount of unrecognized tax benefits was approximately $7.6 million. 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.
Segment and Geographic Information
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 December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
 
(in thousands)
Hong Kong
$
64,229

 
$
71,251

 
$
135,485

 
$
145,878

China
10,156

 
15,336

 
21,048

 
32,965

South Korea
745

 
1,392

 
1,542

 
3,660

United States
425

 
313

 
898

 
656

Other countries
710

 
1,156

 
1,413

 
2,050

 
$
76,265

 
$
89,448

 
$
160,386

 
$
185,209

The following is a summary of revenue by product type:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
 
(in thousands)
Power discrete
$
58,946

 
$
70,801

 
$
124,091

 
$
146,305

Power IC
13,226

 
12,936

 
26,838

 
27,467

Packaging and testing services
4,093

 
5,711

 
9,457

 
11,437

 
$
76,265

 
$
89,448

 
$
160,386

 
$
185,209

 
Long-lived assets, consisting of property, plant and equipment by geographical area are as follows:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
China
$
85,704

 
$
93,663

United States
41,389

 
43,946

Other countries
415

 
502

 
$
127,508

 
$
138,111

Commitments and Contingencies
Commitments and Contingencies
Commitments and Contingencies
Purchase Commitments
As of December 31, 2013 and June 30, 2013, the Company had approximately $30.0 million and $25.8 million, respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services; and approximately $4.2 million and $0.4 million, respectively, of capital commitments for the purchase of property and equipment.
Contingencies and Indemnities
The Company is currently not a party to any 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 thereof or could 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 December 31, 2013 and June 30, 2013.
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 Accounting Policies (Policies)
Nature of Operations [Text Block] 
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 portable 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, Macau, China, Taiwan, Korea and Japan.
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 financial assets 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, 2013. 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 and six months ended December 31, 2013 are not necessarily indicative of the results that may be expected for other interim periods or the fiscal year ending June 30, 2014. The condensed consolidated balance sheet at June 30, 2013 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, 2013.
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, variable interest entities, 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
Comprehensive income 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 consists of cumulative foreign currency translation adjustments. Total comprehensive income is presented in the condensed consolidated statements of comprehensive income.
Recent Accounting Pronouncements 
Recent Accounting Pronouncements
In July 2013, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update ("ASU") 2013-11, Income Taxes (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The new guidance requires the netting of unrecognized tax benefits ("UTBs") against a deferred tax asset for a loss or other carryforward that would apply in settlement of the uncertain tax positions. Under the new standard, UTBs will be netted against all available same-jurisdiction loss or other tax carryforwards that would be utilized, rather than only against carryforwards that are created by the UTBs. The ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. Early adoption is permitted. The ASU should be applied prospectively to all unrecognized tax benefits that exist at the effective date. Retrospective application is permitted. The Company does not expect the adoption of this guidance to have any significant impact on the Company's condensed consolidated financial statements.
Net Income Per Share (Tables)
Schedule of Earnings Per Share, Basic and Diluted 
The following table presents the calculation of basic and diluted net income per share:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands, except per share data)
Numerator:
 
 
 
 
 
 
 
Net income
$
160

 
$
3,718

 
$
467

 
$
11,660

 
 
 
 
 
 
 
 
Denominator:
 
 
 
 
 
 
 
Basic:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income per share
25,846

 
25,292

 
25,765

 
25,165

Diluted:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income per share
25,846

 
25,292

 
25,765

 
25,165

Effect of potentially dilutive securities:
 
 
 
 
 
 
 
Stock options, RSUs and ESPP shares
616

 
809

 
620

 
827

Weighted average number of common shares used to compute diluted net income per share
26,462

 
26,101

 
26,385

 
25,992

Net income per share:
 
 
 
 
 
 
 
Basic
$
0.01

 
$
0.15

 
$
0.02

 
$
0.46

Diluted
$
0.01

 
$
0.14

 
$
0.02

 
$
0.45

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,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
Employee stock options and RSUs
2,700

 
2,841

 
2,742

 
2,768

ESPP to purchase common shares
302

 
187

 
304

 
251

Total potential dilutive securities
3,002

 
3,028

 
3,046

 
3,019

Concentration of Credit Risk and Significant Customers (Tables)
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 December 31,
 
Six Months Ended December 31,
Percentage of revenue
2013
 
2012
 
2013
 
2012
Customer A
22.7
%
 
24.2
%
 
21.6
%
 
23.9
%
Customer B
42.2
%
 
43.8
%
 
43.3
%
 
42.6
%
Customer C
13.0
%
 
11.2
%
 
12.4
%
 
12.5
%
 
December 31,
2013
 
June 30,
2013
Percentage of accounts receivable
 
Customer A
20.4
%
 
33.8
%
Customer B
35.9
%
 
22.6
%
Customer C
17.0
%
 
19.9
%
Balance Sheet Components (Tables)
Schedule of Accounts, Notes, Loans and Financing Receivable 
Accounts receivable:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Accounts receivable
$
54,099

 
$
52,202

Less: Allowance for price adjustments
(15,067
)
 
(13,152
)
Less: Allowance for doubtful accounts
(30
)
 
(752
)
Accounts receivable, net
$
39,002

 
$
38,298

Schedule of Inventory, Current 
Inventories:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Raw materials
$
17,445

 
$
17,248

Work in-process
36,165

 
38,618

Finished goods
9,157

 
12,473

 
$
62,767

 
$
68,339

Property, Plant and Equipment 
Property, plant and equipment:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Land
$
4,950

 
$
4,950

Building
4,106

 
4,106

Manufacturing machinery and equipment
159,338

 
156,958

Equipment and tooling
10,413

 
10,356

Computer equipment and software
16,835

 
16,140

Office furniture and equipment
1,564

 
1,559

Leasehold improvements
24,434

 
24,068

 
221,640

 
218,137

Less accumulated depreciation
(100,932
)
 
(87,180
)
 
120,708

 
130,957

Equipment and construction in progress
6,800

 
7,154

Property, plant and equipment, net
$
127,508

 
$
138,111

Schedule of Other Assets, Noncurrent 
Other long term assets:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Prepayments for property and equipment
$
707

 
$
77

Investment in a privately held company
100

 
100

Deferred debt issuance cost
43

 
91

Office leases deposits
411

 
499

 
$
1,261

 
$
767

Schedule of Accrued Liabilities 
Accrued liabilities:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
Accrued salaries and wages
$
4,216

 
$
3,079

Accrued vacation
968

 
2,078

Accrued bonuses
1,153

 
880

Warranty accrual
1,496

 
1,428

Stock rotation accrual
1,480

 
1,572

Accrued professional fees
607

 
918

ESPP payable
290

 
353

Customer deposits
488

 
123

Other accrued expenses
4,674

 
4,140

 
$
15,372

 
$
14,571

Schedule of Product Warranty Liability 
The activities in the warranty accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2013
 
2012
 
(in thousands)
Beginning balance
$
1,428

 
$
1,556

Additions
1,239

 
733

Utilization
(1,171
)
 
(616
)
Ending balance
$
1,496

 
$
1,673

Stock Rotation Accrual 
The activities in the stock rotation accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2013
 
2012
 
(in thousands)
Beginning balance
$
1,572

 
$
2,032

Additions
2,332

 
3,254

Utilization
(2,424
)
 
(3,519
)
Ending balance
$
1,480

 
$
1,767

Shareholders' Equity and Share-based Compensation (Tables)
Summary of Stock Option Activites 
Stock Options
The following table summarizes the Company's stock option activities for the six months ended December 31, 2013:
 
 
 
Weighted
 
 
 
 
 
Average
 
 
 
Number of
 
Exercise Price
 
Aggregate
 
Shares
 
Per Share
 
Intrinsic Value
Outstanding at June 30, 2013
3,593,854

 
$
10.24

 
$
3,144,506

Granted
77,500

 
7.51

 
 
Exercised
(119,321
)
 
0.98

 
772,342

Canceled or forfeited
(237,461
)
 
11.18

 
 
Outstanding at December 31, 2013
3,314,572

 
$
10.45

 
$
2,409,612


Information with respect to stock options outstanding and exercisable at December 31, 2013 is as follows:
 
Options Outstanding  
 
Options Vested and Exercisable  
 
Number Outstanding
 
Weighted-Average
Remaining Contractual Life (years) 
 
Weighted-Average
Exercise Price
 
Number Exercisable
 
Weighted-Average
Exercise Price
Total options outstanding
3,314,572

 
4.43
 
$
10.45

 
2,778,724

 
$
10.29

Options vested and expected to vest
3,280,477

 
4.36
 
$
10.44

 
 
 
 
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 six months ended December 31, 2013 with the following weighted average assumptions:
 
Six Months Ended December 31,
 
2013
Volatility rate
48%
Risk-free interest rate
1.6% - 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 six months ended December 31, 2013:
 
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, 2013
549,553

 
$
9.50

 
1.87
 
$
4,198,585

Granted
55,804

 
7.65

 
 
 
 
Vested
(71,960
)
 
9.65

 
 
 
 
Forfeited
(73,952
)
 
9.72

 
 
 
 
Nonvested at December 31, 2013
459,445

 
$
9.22

 
1.67
 
$
3,542,321

RSUs vested and expected to vest
415,616

 
 
 
1.60
 
$
3,204,396

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
The Employee Share Purchase Plan (the "ESPP") was established in May 2010 upon the completion of the Company's initial public offering. The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows:
 
Six Months Ended December 31,
 
2013
Volatility rate
50%
Risk-free interest rate
0.1% - 0.3%
Expected term
1.3 years
Dividend yield
0%
Share-based Compensation, Allocation of Recognized Period Costs 
Share-based Compensation Expense
The total share-based compensation expense (reversal) 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 December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
 
(in thousands)
Cost of goods sold
$
142

 
$
141

 
$
338

 
$
339

Research and development
(32
)
 
278

 
263

 
671

Selling, general and administrative
(5
)
 
494

 
713

 
1,344

 
$
105

 
$
913

 
$
1,314

 
$
2,354

Segment and Geographic Information (Tables)
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas 
Long-lived assets, consisting of property, plant and equipment by geographical area are as follows:
 
December 31,
2013
 
June 30,
2013
 
(in thousands)
China
$
85,704

 
$
93,663

United States
41,389

 
43,946

Other countries
415

 
502

 
$
127,508

 
$
138,111

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 December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
 
(in thousands)
Hong Kong
$
64,229

 
$
71,251

 
$
135,485

 
$
145,878

China
10,156

 
15,336

 
21,048

 
32,965

South Korea
745

 
1,392

 
1,542

 
3,660

United States
425

 
313

 
898

 
656

Other countries
710

 
1,156

 
1,413

 
2,050

 
$
76,265

 
$
89,448

 
$
160,386

 
$
185,209

Revenue from External Customers by Products and Services 
The following is a summary of revenue by product type:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2013
 
2012
 
2013
 
2012
 
(in thousands)
 
(in thousands)
Power discrete
$
58,946

 
$
70,801

 
$
124,091

 
$
146,305

Power IC
13,226

 
12,936

 
26,838

 
27,467

Packaging and testing services
4,093

 
5,711

 
9,457

 
11,437

 
$
76,265

 
$
89,448

 
$
160,386

 
$
185,209

Net Income Per Share - Basic and Diluted Income Per Share (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Numerator:
 
 
 
 
Net income
$ 160 
$ 3,718 
$ 467 
$ 11,660 
Basic:
 
 
 
 
Weighted average number of common shares used to compute basic net income per share
25,846 
25,292 
25,765 
25,165 
Effect of potentially dilutive securities:
 
 
 
 
Stock options, RSUs and ESPP shares (in shares)
616 
809 
620 
827 
Weighted average number of common shares used to compute diluted net income per share
26,462 
26,101 
26,385 
25,992 
Net income per share:
 
 
 
 
Basic (in dollars per share)
$ 0.01 
$ 0.15 
$ 0.02 
$ 0.46 
Diluted (in dollars per share)
$ 0.01 
$ 0.14 
$ 0.02 
$ 0.45 
Net Income Per Share - Potential Dilutive Shares (Details)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
 
 
 
 
Potential dilutive securities (in shares)
3,002 
3,028 
3,046 
3,019 
Employee stock options and RSUs
 
 
 
 
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
 
 
 
 
Potential dilutive securities (in shares)
2,700 
2,841 
2,742 
2,768 
ESPP to purchase common shares
 
 
 
 
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
 
 
 
 
Potential dilutive securities (in shares)
302 
187 
304 
251 
Concentration of Credit Risk and Significant Customers - (Details)
6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended
Dec. 31, 2013
Minimum
Dec. 31, 2013
Maximum
Dec. 31, 2013
Customer A
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2012
Customer A
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2013
Customer A
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2012
Customer A
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2013
Customer A
Accounts Receivable
Customer Concentration Risk
Jun. 30, 2013
Customer A
Accounts Receivable
Customer Concentration Risk
Dec. 31, 2013
Customer B
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2012
Customer B
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2013
Customer B
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2012
Customer B
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2013
Customer B
Accounts Receivable
Customer Concentration Risk
Jun. 30, 2013
Customer B
Accounts Receivable
Customer Concentration Risk
Dec. 31, 2013
Customer C
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2012
Customer C
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2013
Customer C
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2012
Customer C
Sales Revenue, Goods, Net
Customer Concentration Risk
Dec. 31, 2013
Customer C
Accounts Receivable
Customer Concentration Risk
Jun. 30, 2013
Customer C
Accounts Receivable
Customer Concentration Risk
Concentration Risk
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Terms of credit sales, (in days)
30 days 
60 days 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Customers greater than 10% of total
 
 
22.70% 
24.20% 
21.60% 
23.90% 
20.40% 
33.80% 
42.20% 
43.80% 
43.30% 
42.60% 
35.90% 
22.60% 
13.00% 
11.20% 
12.40% 
12.50% 
17.00% 
19.90% 
Balance Sheet Components - Accounts receivable (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Balance Sheet Related Disclosures [Abstract]
 
 
Accounts receivable
$ 54,099 
$ 52,202 
Less: allowance for price adjustments
(15,067)
(13,152)
Less: allowance for doubtful accounts
(30)
(752)
Accounts receivable, net
$ 39,002 
$ 38,298 
Balance Sheet Components - Inventories (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Balance Sheet Related Disclosures [Abstract]
 
 
Raw materials
$ 17,445 
$ 17,248 
Work in-process
36,165 
38,618 
Finished goods
9,157 
12,473 
Inventory, net
$ 62,767 
$ 68,339 
Balance Sheet Components - Property, plant, and equipment (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
$ 221,640 
$ 218,137 
Less accumulated depreciation
(100,932)
(87,180)
Property, plant and equipment excluding equipment and construction in progress, net
120,708 
130,957 
Equipment and construction in progress
6,800 
7,154 
Property, plant and equipment, net
127,508 
138,111 
Land
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
4,950 
4,950 
Building
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
4,106 
4,106 
Manufacturing machinery and equipment
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
159,338 
156,958 
Equipment and tooling
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
10,413 
10,356 
Computer equipment and software
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
16,835 
16,140 
Office furniture and equipment
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
1,564 
1,559 
Leasehold improvements
 
 
Property, Plant and Equipment [Line Items]
 
 
Property, plant, and equipment excluding equipment and construction In progress, gross
$ 24,434 
$ 24,068 
Balance Sheet Components - Other long term assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Balance Sheet Related Disclosures [Abstract]
 
 
Prepayments for property and equipment
$ 707 
$ 77 
Investment in a priveately held company
100 
100 
Deferred debt issuance cost
43 
91 
Office leases deposits
411 
499 
Other long-term assets
$ 1,261 
$ 767 
Balance Sheet Components - Accrued liabilites (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Dec. 31, 2012
Jun. 30, 2012
Balance Sheet Related Disclosures [Abstract]
 
 
 
 
Accrued salaries and wages
$ 4,216 
$ 3,079 
 
 
Accrued vacation
968 
2,078 
 
 
Accrued bonuses
1,153 
880 
 
 
Warranty accrual
1,496 
1,428 
1,673 
1,556 
Stock rotation accrual
1,480 
1,572 
1,767 
2,032 
Accrued professional fees
607 
918 
 
 
ESPP payable
290 
353 
 
 
Customer deposits
488 
123 
 
 
Other accrued expenses
4,674 
4,140 
 
 
Accrued liabilities
$ 15,372 
$ 14,571 
 
 
Balance Sheet Components - Product Warranty Accrual (Details) (USD $)
In Thousands, unless otherwise specified
6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
 
 
Beginning balance
$ 1,428 
$ 1,556 
Additions
1,239 
733 
Utilization
(1,171)
(616)
Ending balance
$ 1,496 
$ 1,673 
Balance Sheet Components - Stock Rotation Accrual (Details) (USD $)
In Thousands, unless otherwise specified
6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Stock Rotation Accrual Increae (Decrease) [Roll Forward]
 
 
Beginning balance
$ 1,572 
$ 2,032 
Additions
2,332 
3,254 
Utilzation
(2,424)
(3,519)
Ending balance
$ 1,480 
$ 1,767 
Debt - (Details)
6 Months Ended 6 Months Ended 6 Months Ended
Dec. 31, 2013
USD ($)
Subsidiaries
Dec. 31, 2013
CNY
Subsidiaries
Dec. 31, 2013
Federal funds rate
Dec. 31, 2013
Eurodollar rate
Dec. 31, 2013
Minimum
LIBOR rate
Dec. 31, 2013
Minimum
Margin Rate
Dec. 31, 2013
Maximum
LIBOR rate
Dec. 31, 2013
Maximum
Margin Rate
Dec. 31, 2013
CHINA
Subsidiaries
Dec. 31, 2013
Variable Interest Rate Term Loan Maturing May 2015
Notes Payable to Banks
USD ($)
Jun. 30, 2013
Variable Interest Rate Term Loan Maturing May 2015
Notes Payable to Banks
USD ($)
May 11, 2012
Variable Interest Rate Term Loan Maturing May 2015
Notes Payable to Banks
USD ($)
Dec. 31, 2013
State of Oregon Loan
Loans Payable
USD ($)
Jun. 30, 2013
State of Oregon Loan
Loans Payable
USD ($)
Jul. 17, 2012
State of Oregon Loan
Loans Payable
USD ($)
Dec. 31, 2013
Subsidiaries [Member]
USD ($)
Dec. 31, 2013
Subsidiaries [Member]
Maximum
Debt Instrument [Line Items]
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Line of Credit Facility, Amount Outstanding
 
 
 
 
 
 
 
 
 
 
 
$ 0 
 
 
 
$ 0 
 
Loan, principal amount
 
 
 
 
 
 
 
 
 
 
 
20,000,000.0 
 
 
250,000 
 
 
Line of Credit Facility, Maximum Borrowing Capacity
15,700,000 
95,000,000 
 
 
 
 
 
 
 
 
 
10,000,000.0 
 
 
 
 
 
Debt instrument, basis spread on variable rate
 
 
0.50% 
1.00% 
1.00% 
(0.50%)
1.75% 
0.25% 
 
 
 
 
 
 
 
 
 
Outstanding balance of loan
 
 
 
 
 
 
 
 
 
15,000,000 
17,100,000 
 
269,000 
262,000 
 
 
 
Outstanding balance of loan due in the next 12 months
 
 
 
 
 
 
 
 
 
$ 2,900,000 
$ 3,600,000 
 
 
 
 
 
 
Number of subsidiaries securing obligations under loan agreement
2 
2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Number of subsidiaries with revolving lines of credit
 
 
 
 
 
 
 
 
2 
 
 
 
 
 
 
 
 
Line of credit facility, subsidiaries, borrowing capacity, maximum percent of accounts receivable
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
80.00% 
Repayment term of line of credit (in days)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
120 days 
Interest rate on loan
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5.00% 
 
 
Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) (USD $)
In Millions, except Share data, unless otherwise specified
0 Months Ended 3 Months Ended 6 Months Ended 38 Months Ended
Oct. 22, 2010
Dec. 31, 2013
Dec. 31, 2013
Dec. 31, 2013
Class of Stock [Line Items]
 
 
 
 
Share repurchase program, authorized amount (USD in Millions)
$ 25.0 
 
 
 
Treasury stock acquired, shares repurchased (in shares)
 
0 
0 
241,770 
Treasury stock acquired, average price per share (in dollars per share)
 
 
 
$ 9.40 
Treasury stock acquired (USD In Millions)
 
 
 
$ 2.3 
Treasury Stock Reissued
 
 
 
 
Class of Stock [Line Items]
 
 
 
 
Treasury stock acquired, average price per share (in dollars per share)
 
$ 13.82 
$ 13.82 
$ 13.81 
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)
 
2,700 
2,950 
18,750 
Treasury stock reissued, average price per share (in dollars per share)
 
 
 
$ 3.47 
Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) (USD $)
3 Months Ended 6 Months Ended 38 Months Ended
Dec. 31, 2013
Dec. 31, 2013
Dec. 31, 2013
Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Treasury stock acquired, shares repurchased (in shares)
0 
0 
241,770 
 
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
 
 
 
 
Outstanding at June 30, 2013 (in shares)
 
3,593,854 
 
 
Granted (in shares)
 
77,500 
 
 
Exercised (in shares)
 
(119,321)
 
 
Canceled or forfeited (in shares)
 
(237,461)
 
 
Outstanding at December 31, 2013 (in shares)
3,314,572 
3,314,572 
3,314,572 
 
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
 
 
 
 
Outstanding at June 30, 2013 (in dollars per share)
 
$ 10.24 
 
 
Granted (in dollars per share)
 
$ 7.51 
 
 
Exercised (in dollars per share)
 
$ 0.98 
 
 
Canceled or forfeited (in dollars per share)
 
$ 11.18 
 
 
Outstanding at December 31, 2013 (in dollars per share)
$ 10.45 
$ 10.45 
$ 10.45 
 
Options Outstanding Aggregate Intrinsic Value
$ 2,409,612 
$ 2,409,612 
$ 2,409,612 
$ 3,144,506 
Options Exercised Aggegate Intrinsic Value
 
$ 772,342 
 
 
Employee Stock [Member]
 
 
 
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Volatility Rate
 
50.00% 
 
 
Expected Term
 
1 year 3 months 18 days 
 
 
Expected Dividend Rate
 
0.00% 
 
 
Employee Stock [Member] |
Minimum
 
 
 
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Risk Free Interest Rate
 
0.10% 
 
 
Employee Stock [Member] |
Maximum
 
 
 
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Risk Free Interest Rate
 
0.30% 
 
 
Stock Options [Member]
 
 
 
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Volatility Rate
 
48.00% 
 
 
Expected Term
 
5 years 6 months 
 
 
Expected Dividend Rate
 
0.00% 
 
 
Stock Options [Member] |
Minimum
 
 
 
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Risk Free Interest Rate
 
1.60% 
 
 
Stock Options [Member] |
Maximum
 
 
 
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
 
 
 
 
Risk Free Interest Rate
 
1.70% 
 
 
Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) (USD $)
6 Months Ended
Dec. 31, 2013
Jun. 30, 2013
Share-based Compensation [Abstract]
 
 
Options, Number Outstanding (in shares)
3,314,572 
3,593,854 
Options, Weighted-Average Remaining Contractual Life (in years)
4 years 5 months 5 days 
 
Options, Weighted-Average Exercise Price (in dollars per share)
$ 10.45 
$ 10.24 
Options, Number Exercisable (in shares)
2,778,724 
 
Options, Weighted-Average Exercise Price (in dollars per share)
$ 10.29 
 
Options vested and expected to vest, Number Outstanding (in shares)
3,280,477 
 
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)
4 years 4 months 10 days 
 
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)
$ 10.44 
 
Shareholders' Equity and Share-based Compensation - Restricted Stock Activity (Details) (USD $)
6 Months Ended 12 Months Ended
Dec. 31, 2013
Jun. 30, 2013
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 3 months 18 days 
 
Restricted Stock
 
 
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
 
 
Nonvested
549,553 
 
Granted
55,804 
 
Vested
(71,960)
 
Forfeited
(73,952)
 
Nonvested
459,445 
549,553 
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
 
 
Nonvested
$ 9.50 
 
Granted
$ 7.65 
 
Vested
$ 9.65 
 
Forfeited
$ 9.72 
 
Nonvested
$ 9.22 
$ 9.50 
Weighted Average Remaining Recognition Period (Years)
1 year 8 months 1 day 
1 year 10 months 13 days 
RSUs Nonvested Aggregate Intrinsic Value
$ 3,542,321 
$ 4,198,585 
RSUs vested and expected to vest, Outstanding (in shares)
415,616 
 
RSUs vested and expected to vest, Weighted Average Remaining Recognition Period (in years)
1 year 7 months 6 days 
 
RSUs vested and expected to vest, Aggregate Intrinsic Value
$ 3,204,396 
 
Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) (USD $)
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
 
 
 
 
Allocated share-based compensation expense
$ 105,000 
$ 913,000 
$ 1,314,000 
$ 2,354,000 
Unrecognized compensation expense
3,800,000 
 
3,800,000 
 
Recognition period of share-based compensation expense (in years)
 
 
1 year 3 months 18 days 
 
Cost of goods sold
 
 
 
 
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
 
 
 
 
Allocated share-based compensation expense
142,000 
141,000 
338,000 
339,000 
Research and development
 
 
 
 
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
 
 
 
 
Allocated share-based compensation expense
(32,000)
278,000 
263,000 
671,000 
Selling, general and administrative
 
 
 
 
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
 
 
 
 
Allocated share-based compensation expense
$ (5,000)
$ 494,000 
$ 713,000 
$ 1,344,000 
Income Taxes - Narrative (Details) (USD $)
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Income Tax Disclosure [Abstract]
 
 
 
 
Income tax expense
$ 1,123,000 
$ 1,085,000 
$ 2,125,000 
$ 2,897,000 
Estimated effective income tax rate
87.50% 
22.60% 
82.00% 
19.90% 
Unrecognized tax benefits
$ 7,600,000 
 
$ 7,600,000 
 
Segment and Geographic Information - Revenue by Location and Product Type (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
$ 76,265 
$ 89,448 
$ 160,386 
$ 185,209 
Power discrete
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
58,946 
70,801 
124,091 
146,305 
Power IC
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
13,226 
12,936 
26,838 
27,467 
Packaging and testing services
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
4,093 
5,711 
9,457 
11,437 
Hong Kong
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
64,229 
71,251 
135,485 
145,878 
China
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
10,156 
15,336 
21,048 
32,965 
South Korea
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
745 
1,392 
1,542 
3,660 
United States
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
425 
313 
898 
656 
Other countries
 
 
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
 
 
Revenue
$ 710 
$ 1,156 
$ 1,413 
$ 2,050 
Segment and Geographic Information - Long-lived Assets (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
Property, plant and equipment, net
$ 127,508 
$ 138,111 
China
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
Property, plant and equipment, net
85,704 
93,663 
United States
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
Property, plant and equipment, net
41,389 
43,946 
Other countries
 
 
Revenues from External Customers and Long-Lived Assets [Line Items]
 
 
Property, plant and equipment, net
$ 415 
$ 502 
Segment and Geographic Information - Narratives (Details)
6 Months Ended
Dec. 31, 2013
Segment
Segment Reporting [Abstract]
 
Number of operating segments
1 
Number of reportable segments
1 
Commitments and Contingencies - Purchase Commitments (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2013
Jun. 30, 2013
Raw materials, wafers, and packaging and testing services puchase commitments
 
 
Purchase Commitment, Excluding Long-term Committment [Line Items]
 
 
Purchase commitment, amount
$ 30.0 
$ 25.8 
Property and equipment purchase commitments
 
 
Purchase Commitment, Excluding Long-term Committment [Line Items]
 
 
Purchase commitment, amount
$ 4.2 
$ 0.4 
Commitments and Contingencies - Guarantees (Details) (Indemnification Agreement, USD $)
Dec. 31, 2013
Jun. 30, 2013
Indemnification Agreement
 
 
Loss Contingencies [Line Items]
 
 
Indemnifications accrual
$ 0 
$ 0