Thermo-mechanical finite element simulation and visco-plastic solder fatigue for low voltage discrete package

Abstract

Nowadays, solder reliability in new power electronic packages is an important research topic. Therefore, it is of paramount importance to properly understand and model the material behaviour and to develop a calculation model to predict reliability performances. This work presents a thermo-mechanical analysis of different solder layers for a low voltage discrete package. The solder joint reliability between package and PCB is also considered in the simulation. This modelling activity is possible by employing the Anand visco-plastic model and by means of a finite element model implemented in COMSOL. The number of cycles to failure can be subsequently computed, with the Darveaux method, for fatigue life estimation purpose.