Nonlinear Behavior Study on Effect of Hardening Rule of Lead Free Solder Joint

In lead free solder joint, the hardening characteristics must be considered accurately in the FEM (Finite element method) analysis because the estimation of the stress arising at the interface in solder joint is important and the work hardening after yielding is relatively remarkable. In this paper, the effect of the hardening rule on stress and nonlinear strain estimation of lead free solder joint is examined using mechanical fatigue test and FEM analysis. And it is proven that the equivalent stress and nonlinear strain of lead free solder joint can be calculated by using isotropic hardening rule in stead of kinematic hardening rule like the Sn-37Pb eutectic solder.