Note 1 - Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 30, 2019

Notes Tables

Reclassification of Amounts on Income Statement [Table Text Block]

Three Months Ended March 31, 2018	As Presented		Amortization of Purchased Intangibles			Foreign Transaction Gains and Losses			As Adjusted
Cost of Sales	$	55,599		(676	)		-		$	54,923
SG&A Expense	$	17,763		(398	)		(1,579	)	$	15,786

Schedule of Inventory, Current [Table Text Block]

	March 30,		December 29,
	2019		2018
Raw materials and purchased parts	$	63,352	$	60,112
Work in process		51,705		57,953
Finished goods		15,687		21,249
Total inventories	$	130,744	$	139,314

Property, Plant and Equipment [Table Text Block]

	March 30,			December 29,
	2019			2018
Land and land improvements	$	12,260		$	11,905
Buildings and building improvements		36,126			37,265
Machinery and equipment		64,707			64,791
		113,093			113,961
Less accumulated depreciation and amortization		(41,301	)		(39,629	)
Property, plant and equipment, net	$	71,792		$	74,332

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended
	March 30,			March 31,
	2019			2018
Cost of sales	$	125		$	121
Research and development		638			349
Selling, general and administrative		2,930			1,199
Total share-based compensation		3,693			1,669
Income tax benefit		(280	)		(314	)
Total share-based compensation, net	$	3,413		$	1,355

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Three Months Ended
	March 30,		March 31,
	2019		2018
Weighted average common shares		40,872		28,602
Effect of dilutive securities		-		929
		40,872		29,531

Disaggregation of Revenue [Table Text Block]

	Three Months Ended
Disaggregrated Net Sales (1)	March 30, 2019		March 31, 2018
Systems:
Semiconductor Test & Inspection	$	79,940	$	54,905
PCB Test		6,972		N/A
Non-systems:
Semiconductor Test & Inspection		56,753		40,245
PCB Test		4,144		N/A
Total net sales	$	147,809	$	95,150

	Three Months Ended
Disaggregrated Net Sales	March 30, 2019		March 31, 2018
China	$	23,551	$	20,243
United States		17,101		14,478
Malaysia		17,714		11,809
Taiwan		14,970		2,941
Philippines		14,541		10,546
Rest of the World		59,932		35,133
Total net sales	$	147,809	$	95,150

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended
	March 30,			March 31,
	2019			2018
Semiconductor Test & Inspection (1)
Customers individually accounting for more than 10% of net sales	one			one
Percentage of net sales		11	%		12	%
PCB Test
Customers individually accounting for more than 10% of net sales		*			N/A
Percentage of net sales		*			N/A