Deformation and Crack Growth in Cu Metallization of AMC Substrate Used in High Temperature SiC Power Converter

Abstract

Currently, the power modules are mainly manufactured with silicon (Si) power devices which have a junction temperature (Tj) generally less than 150 °C. The AMC (active metal brazed copper) ceramic substrate can meet the requirements of fabricating the Si-based power modules. With the practical application of the SiC power devices in power modules, development of the high temperature SiC converters become possible. However, reliability of the AMC substrate at high temperatures, especially under severe thermal cycling conditions should be made clear. In this presentation, we report the results of the AMC Si3N4 substrate stressed under thermal cycling conditions between -40 to 250℃. The surface roughness of the AMC substrate increased with thermal cycles. Cracks formed in the Cu layer and grew with thermal cycles. The Cu layer was seriously oxidized in the cracks.