Reliability analysis of SiP module board level bending test

The system-in-package (SiP) is widely used in communication device that integrated multi components and packages into one system. However, the board level reliability performance becomes more important, especially cyclic bending test. In the work, both experimental and numerical model are performed to investigate the four point cyclic bending test with different load displacement. The bending test experiment was analyzed by Weibull method to calculate the solder fatigue life of SiP module. A three-dimension finite element method (FEM) and the Anand's visco-plasticity Model are used to simulate solder's creep behavior under cyclic bending test. It was constructed and experimentally benchmarked to qualitatively figure out solder joint failure location in whole package and crack position in solder interconnection. Besides, the constructive index, plastic work density (PWD) accumulated per cycle, is used to evaluate the risk of solder fatigue cracking failure and be correlated well from experimental characteristic cycles. This work provides design guideline for SiP module board level reliability under bending test. The factors that underfill dispensing effect and material type suggestion are also considered in this work.