Study on power cycling reliability of power module with single metal layer flexible substrate by finite element analysis

In this paper, the power cycling simulation model was built up to study the thermo-mechanical reliability of the power electronic package test vehicle with single metal layer flexible substrate. The power cycling simulation includes thermal analysis and thermo-mechanical analysis. The temperature distribution of the high power electronic package was obtained by the thermal analysis. The stress and strain behaviors of the die attach materials and Al bonding wires of the power electronic package were investigated by the coupled thermo-mechanical simulation. The fatigue lives of the die attach materials and Al bonding wires were estimated by the plastic-strain based Coffin-Manson fatigue life prediction model. The effects of the die materials, epoxy molding compound (EMC) and die attach materials were also investigated by the parametric studies with the numerical simulation results.