Research on Probabilistic Failure Physical Model of BGA Solder Joints in Multiple Fields Coupling

Ball Grid Array (BGA) solder joints are often subjected to temperature stress and vibration stress at the same time during the service process. The failure of such solder joints under multi-field coupling is a major problem in long-term evaluation of solder joint life. To couple the creep damage and fatigue damage of solder joints, a nonlinear damage accumulation method is proposed in this paper. And based on the creep damage model and fatigue damage model of BGA solder joint under continuous damage mechanics, a creep-fatigue coupled failure physical model of BGA solder joint is established. In addition, a Bayesian updating method combining model parameters with variables is proposed to realize the probabilization of the coupled failure physical model. And a complete process of parameter probabilization is formed, which provides theoretical guidance for the probability of the model in high dimension. What's more, the model is verified by temperature-vibration coupling experiment of single solder joint specimen, which shows that the coupled failure physical model can predict the life of BGA solder joints effectively.