Life prediction of CBGA soldered joints under extreme temperature thermal shock

Deep space exploration requires operations under extreme cold temperature and wide temperature range condition. Thus, it is significant to investigate the reliability of electronic device under such condition. In this study, multilinear isotropic hardening (MISO) model was used to describe the mechanical behavior of Sn63Pb37 and Sn96.5Ag3.0Cu0.5 solders, the stress and strain distribution of soldered joints under extreme temperature thermal shock were obtained. In the end, the thermal fatigue life of CBGA was predicted by Darveaux energy model. The results showed that the maximum stress caused by a local stress condition was located in the interface of pad on the package side and solder. Fatigue life of soldered joints under extreme temperature thermal shock was much lower than that of soldered joints under thermal cycling with standard temperature range.