Organization and Significant Accounting Policies (Tables)

9 Months Ended

Sep. 23, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Customers as Percentage of Total Sales

The Company’s most significant customers (having accounted for 10% or more of sales) and their related sales as a percentage of total sales were as follows:

	Three Months Ended						Nine Months Ended
	September 23,			September 25,			September 23,			September 25,
	2016			2015			2016			2015
Lam Research Corporation		49.5	%		49.4	%		53.5	%		50.4	%
Applied Materials, Inc.		30.9			26.4			27.3			27.1
Total		80.4	%		75.8	%		80.8	%		77.5	%

Assets or Liabilities Measured at Fair Value

The following table summarizes, for assets or liabilities measured at fair value, the respective fair value and the classification by level of input within the fair value hierarchy (in thousands):

			Fair Value Measurement at
			Reporting Date Using
Description	September 23, 2016		QuotedPrices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Other liabilities:
Interest rate swap	$	56	$	—	$	56	$	—
Contingent earn-out liability	$	2,236	$	—	$	—	$	2,236

			Fair Value Measurement at
			Reporting Date Using
Description	December 25, 2015		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash and cash equivalents:
Money market fund deposits	$	640	$	640	$	—	$	—
Other liabilities:
Interest rate swap	$	23	$	—	$	23	$	—
Contingent earn-out liability	$	831	$	—	$	—	$	831

Schedule of Option Activity

Stock option activity for the nine months ended September 23, 2016:

	Shares			Weighted Average Exercise Price		Weighted Remaining Contractual Life (years)		Aggregate IntrinsicValue (in thousands)
Outstanding at December 25, 2015		315,648		$	10.02		2.06	$	216
Granted
Exercised		(100,000	)		3.96
Cancelled		(50,489	)	$	11.74
Outstanding at September 23, 2016		165,159		$	13.17		0.74	$	103
Options exercisable at September 23, 2016		165,159		$	13.17		0.74	$	103

Summary of Restricted Stock Unit and Restricted Stock Award Activity

The following table summarizes the Company’s RSU and RSA activity for the nine months ended September 23, 2016:

	Shares			Aggregate FairValue (in thousands)
Unvested restricted stock units and restricted stock awards    at December 25, 2015		1,267,942		$	6,563
Granted		1,116,360
Vested		(645,926	)
Forfeited		(266,704	)
Unvested restricted stock units and restricted stock awards    at September 23, 2016		1,471,672		$	10,361
Vested and expected to vest restricted stock units and    restricted stock awards at September 23, 2016		1,228,188		$	8,646

Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations

The following table shows the Company’s stock-based compensation expense included in the Condensed Consolidated Statements of Operations (in thousands):

	Three Months Ended						Nine Months Ended
	September 23,			September 25,			September 23,			September 25,
	2016			2015			2016			2015
Cost of sales (1)	$	362		$	304		$	828		$	908
Research and development		1,277			658			1,405			1,247
Sales and marketing		76			49			253			150
General and administrative		142			103			1,554			302
		1,857			1,114			4,040			2,607
Income tax benefit		(935	)		(310	)		(3,979	)		(746	)
Stock-based compensation expense, net of tax	$	922		$	804		$	61		$	1,861

(1) Stock-based compensation expenses capitalized in inventory for the three and nine months ended September 23, 2016 and September 25, 2015 were not significant.