Chip scale packaging with surface mountable solder ball terminals for microsensors

This paper presents a simple and low-cost flip chip bumping method with vertical feedthroughs for MEMS WLCSP. The vertical feedthroughs are fabricated on glass wafer using sand-blasting, and these provide inherent aligning jig for micro-ball arrangement. The experimental evaluations using MEMS accelerometer are also presented. The proposed method can be a more cost-effective solution by eliminating the conventional expensive and complex process including electroplating or ball-aligning jig. The feasibility of WLCSP is experimentally demonstrated by testing the developed devices.