Abstract
When we estimate the fatigue life of solder joints, we have to conduct FE analysis with a constitutive model which can exhibit dynamic property of Pb free solder. We proposed a creep-plasticity unified viscoplastic constitutive model with Armstrong-Frederick type nonlinear kinematic hardening rule which can describe temperature and rate dependent cyclic stress-strain relations. Then, we implemented the proposed model into finite element code MARC and analyzed tension tests and the tension-compression tests of Sn3.5Ag0.5Cu0.07Ni0.01Ge solder. We compared test data with analytical FE results of the proposed model, anand model and classical creep-prasticity decoupled model. It was confirmed that analytical results using the proposed model were in good agreements with the experimental results.
