GEOGRAPHIC AND CUSTOMER CONCENTRATION INFORMATION - Net Sales by Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 38,430	$ 33,840	$ 123,657	$ 78,651
Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	100.10%	100.00%	100.00%	100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	8,188	1,045	18,763	7,380
United States | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	21.00%	3.00%	15.00%	9.00%
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	15,613	9,998	49,735	12,273
South Korea | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	41.00%	30.00%	40.00%	16.00%
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	853	1,450	16,202	5,410
China | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	2.00%	4.00%	13.00%	7.00%
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	10,746	15,753	27,066	42,477
Taiwan | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	28.00%	47.00%	22.00%	54.00%
Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	1,718	3,377	5,588	6,736
Other Asia | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	5.00%	10.00%	5.00%	9.00%
Europe and others
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 1,312	$ 2,217	$ 6,303	$ 4,375
Europe and others | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	3.00%	6.00%	5.00%	5.00%