The investigation by numerical simulation of thermal induced deformation in a double soldered chip structure

The overvoltages and/or overcurrents generated by the repetitive power cycling can highly impact the power MOSFET integrated circuits (IC) lifetime. Hence, these devices are often subjected to defects. The predominant defects meet in power MOSFET IC based on copper clip technology are solder fatigue and aluminum degradation [1]. The root cause is the Coefficient of Thermal Expansion (CTE) mismatch between the constitutive materials, leading to chip metallization deformation (e.g., wrinkles in metal layers). In this paper, the accumulation of mechanical deformation is assessed by numerical simulation during several temperature cycles under the influence of various geometry dimensions.