Cost-effective Capacitive Testing for Fine Pitch RDL First

Redistribution layer (RDL) first is advantageous to enhance the total yield of fan out wafer level package (FOWLP) and fan out panel level package (FOPLP). The key to success is a cost effective testing to assure reliability of known good RDL prior to KGD attachment. This paper shows a cost effective single-sided open/short testing utilized femto farad capacitance tester. The capacitive test vehicle performed RDL includes fine pitched of line width/line spacing 2um/2um for a glass carrier panel level package. The result shows the throughput advantage than double-sided resistance based open/shot test.