Design and assembly process simulation for an automotive power module

In this paper, an automotive power module (APM) package is considered with multiple die including MOSFETs, passive components, shunt resistor and thermistor attached on the direct bonded copper (DBC) substrate. 3D finite element models for design and assembly process are generated in order to conduct the DoE numerical simulations for each design and assembly process. In design phase, both electrical and thermal simulations are carried out to improve the electrical and thermal performance. The electrical resistance and inductance are examined in order to minimize the package effects on Rds(on) and switching noise. Thermal characterization is conducted for the APM heat dissipation design evaluation. In assembly manufacturing process, molding is a very critical process to ensure the high reliability of the APM product. Molding simulation is discussed to check the flow front, gate design option and the possible voids track. The mechanical simulation is also conducted to check the warpages and stresses after molding and the APM mounting process to see if package cracking, or delamination might occur in these assembly processes. Modeling is conducted to determine the proper clamping force for low clearance and avoid high stress in ceramic.