Influences of DBC metal layout on the reliability of IGBT power modules
This paper presents a study of the influences of DBC metal trace layout on the reliability of the high power IGBT module. The research is conducted on a seven-layer IGBT package model using finite element analysis simulation. A parametric study is carried out at different temperatures to simulate the thermal-cycling scenario. It shows in simulation that both total deformation and thermal stress are not balanced even at the symmetrical edges of the module. The stress is related to the metal trace area on the DBC, and larger metal area results in higher thermal stress. Thermal-cycling experiment results verify the analysis to a certain extent. With this knowledge, the paper proposes an improved layout by adding grids to the metal area. The new design can reduce thermal stress and achieve higher reliability of the module.