Note 1 - Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 28, 2020

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	March 28,		December 28,
	2020		2019
Raw materials and purchased parts	$	73,222	$	69,665
Work in process		44,381		46,591
Finished goods		17,256		14,450
Total inventories	$	134,859	$	130,706

Property, Plant and Equipment [Table Text Block]

	March 28,			December 28,
	2020			2019
Land and land improvements	$	8,650		$	11,659
Buildings and building improvements		40,593			41,474
Machinery and equipment		59,029			61,006
		108,272			114,139
Less accumulated depreciation and amortization		(43,584	)		(43,227	)
Property, plant and equipment, net	$	64,688		$	70,912

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

	Three Months Ended
	March 28,			March 30,
	2020			2019
Cost of sales	$	212		$	125
Research and development		833			638
Selling, general and administrative		2,566			2,930
Total share-based compensation		3,611			3,693
Income tax benefit		(172	)		(280	)
Total share-based compensation, net	$	3,439		$	3,413

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

	Three Months Ended
	March 28,		March 30,
	2020		2019
Weighted average common shares		41,502		40,872
Effect of dilutive securities		-		-
		41,502		40,872

Disaggregation of Revenue [Table Text Block]

	Three Months Ended
Disaggregated Net Sales	March 28, 2020		March 30, 2019
Systems:
Semiconductor Test & Inspection	$	70,539	$	79,940
PCB Test		6,840		6,972
Non-systems:
Semiconductor Test & Inspection		57,474		56,753
PCB Test		4,068		4,144
Total net sales	$	138,921	$	147,809

	Three Months Ended
Disaggregated Net Sales	March 28, 2020		March 30, 2019
China	$	30,811	$	23,551
United States		19,078		17,101
Malaysia		15,174		17,714
Taiwan		13,881		14,970
Philippines		10,022		14,541
Rest of the World		49,955		59,932
Total net sales	$	138,921	$	147,809

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

	Three Months Ended
	March 28,			March 30,
	2020			2019
Semiconductor Test & Inspection
Customers individually accounting for more than 10% of net sales		two			one
Percentage of net sales		26	%		11	%
PCB Test
Customers individually accounting for more than 10% of net sales		*			*
Percentage of net sales		*			*