Parameter optimization in assembly manufacturing process for a power module

In this paper, the trimming process in manufacture of a power module is investigated by using the commercial FE code Ansys/LS-dyna®. The setup of the trimming process consists of an automated system of cutting die, stripper, punch, and etc. The design and interworking of these tools are quite critical. On one hand, when the gap between the punch and stripper/cutting die is too big, the dambar may not be fully cut as expected. On the other hand, when the gap is too small, the punch might be broken after some cycles due to flash contamination on the tools. If the stripper clamp is too close to the package body, high stress might be generated in the package edge or even in the silicon chips to induce package crack or die crack. The DoE legs with regard to the gap between the punch & stripper and the distance between the stripper clamp & the package body are conducted by the FE dynamic simulations. The simulation results provide good guidance for the assembly process parameter setting.