Study of Solder Bump and Joint Standoff Height Profiles Using Empirical and Numerical Methods

Solder bump technology is crucial for the advanced packaging of semiconductor devices, providing the essential electrical and mechanical interconnects in high-performance applications like Flip Chip (FC) and Ball Grid Array (BGA) packages. Optimizing solder bump geometry, particularly the bump and standoff height, directly impacts manufacturing yields and long-term reliability. Proper solder bump height optimization can help to reduce mechanical stress and mitigate issues such as electromigration, thermal fatigue, and warpage, which are especially critical in 3D packaging solutions like Chip-on-Wafer (CoW) and Chip-on-Substrate. This paper explores the methodology of solder bump and joint standoff height profiles using both the empirical and numerical methods, then compare with experimental results. Analytical method provides initial estimations of simple circular pad shape, while Surface Evolver method for complex geometries and loading conditions.