Reliability of Silicone and Epoxy Resin Encapsulated Power Modules in HV-H3TRB tests with Thin-Resin coated Dice

Soft silicone gels, as the standard potting materials for power electronic modules, provide little protection against water ingress and thus cannot protect the semiconductors inside the module from corrosion and edge termination breakdown. A novel vacuum assisted potting process employing an epoxy potting material and a thin-resin coat on the semiconductor should provide a significantly improved protection against water absorption indicated degradation. For validation, test modules were built up and tested in an HV-H3TRB environment.