High Reliability Fine Pitch WLCSP for High Pin Count Applications
Wafer Level Chip Scale Packages (WLCSP) have seen wider adoption in hand held as well as automotive electronics in recent years due to their unmatched form factor reductions and improved electrical performance. WLCSP's have gained popularity in high pin count IC's with tighter pitches and increased reliability requirements. Enhanced board level reliability is achieved by using solder spheres with higher silver content. Traditionally, automotive applications require an improvement in thermal cycling over WLCPS found in hand held applications. This paper will study the differences in solder alloy and include a comparison to under filled parts to meet these reliability requirements. This study shows characteristic life that exceeds the industry standard requirements for the drop and thermal testing reliability testing.