Simulation for Enhancing Automotive Power Module DBC Reliability During Assembly Process

In this paper, a comprehensive finite element analysis (FEA) modeling is established for the assembly process of APM DBC. In the model, multiple contact pairs are defined between molding cavity, DBC and assembly support pins. The lead frame is attached on DBC corners by solder paste, and the support pins clamp lead frame at DBC corners. The molding cavity is designed in a pre-deformed shape, which is considered as rigid body due to its high stiffness. The FEA model also considers the pre-deformation relief design in which an additional smaller mold cavity is built at the DBC bottom surface to reduce the DBC ceramic stress in the assembly clamping process. Parametric models with different die attaches, different yield stresses of lead frame material, different lead frame designs, different gaps between DBC and molding cavity, different support pin positions, different ceramic thicknesses and different molding cavity relief designs are simulated. Correlation between the simulation and the actual assembly process is made to support and validate the simulation prediction for the DBC reliability. Through the simulation, we wish to obtain a robust design methodology to enhance the reliability of APM DBC in assembly process.