Product and Geographic Information Net sales by market (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Sep. 26, 2015	Jun. 27, 2015	Apr. 01, 2017	Apr. 02, 2016	Mar. 28, 2015
Revenue from External Customer [Line Items]
Revenue, Net	$ 49,918	$ 33,779	$ 29,658	$ 47,668	$ 51,486	$ 43,342	$ 46,472	$ 43,091	$ 161,023	$ 184,391	$ 159,118
Printed Circuit Board [Member]
Revenue from External Customer [Line Items]
Revenue, Net									88,771	94,121
Component Test [Member]
Revenue from External Customer [Line Items]
Revenue, Net									22,381	19,901
Semiconductor [Member]
Revenue from External Customer [Line Items]
Revenue, Net									29,557	38,262
Industrial Machining [Member]
Revenue from External Customer [Line Items]
Revenue, Net									$ 20,314	$ 32,107