Damage based PoF model of solder joints under temperature cycling and electric coupling condition

To predict the life of solder joints under temperature cycling and electric coupling condition, this paper proposes a Physics of Failure (PoF) model based on the continuum damage mechanics (CDM). Firstly, considering the effect of current on solder's mechanical properties, the current-affected constitutive models of plastic fatigue and creep are constructed. Then, based on the mechanism of energy dissipation, a unified creep-plasticity damage evolution law is deduced, and the nonlinear accumulation damage model is developed. Choosing electric resistance as the indirect damage variable measure, the thermal-electric coupling PoF model is finally established by substituting the current-affected constitutive models into the damage evolution model. A thermal-electric coupling test is carried out to verify the accuracy of PoF model. The experimental results confirm that the proposed PoF model can effectively predict the life of solder joints under temperature cycling and electric coupling condition.