GEOGRAPHIC AND CUSTOMER CONCENTRATION INFORMATION - Net Sales by Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 42,029	$ 24,574	$ 85,227	$ 44,811
Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	100.00%	100.00%	100.00%	100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	6,392	3,252	10,575	6,336
United States | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	15.00%	13.00%	12.00%	14.00%
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	23,863	1,407	34,122	2,275
South Korea | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	57.00%	6.00%	40.00%	5.00%
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	2,268	2,008	15,349	3,960
China | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	5.00%	8.00%	18.00%	9.00%
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	5,498	14,659	16,320	26,724
Taiwan | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	13.00%	60.00%	19.00%	60.00%
Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	1,589	2,292	3,870	3,358
Other Asia | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	4.00%	9.00%	5.00%	7.00%
Europe and others
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 2,419	$ 956	$ 4,991	$ 2,158
Europe and others | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	6.00%	4.00%	6.00%	5.00%