Viscoplastic Behaviour Reliability Analysis of IGBT Module Solders

The major failure mode of power IGBT is the thermal fatigue of the solder joints. The thermal heating induces mechanical constraints due to the various coefficients of thermal expansion of different materials. The life in fatigue, bound to the non-elastic energy dissipated during a cycle, depends strongly on the geometrical shape of solder, on the non-linear behaviour and on the applied load. The reliability methods are then applied here with response surface method and neural networks