Reliability Enhancement of High-Power Semiconductor Modules with Insulated Metal Baseplate and Epoxy Encapsulation

Abstract:
Power semiconductor module reliability is the most important factor for determining long term service life. To improve the module reliability under harsh environment operation, enhancement of the module package isolation and encapsulation materials are required. Together with an insulated metal baseplate (IMB), the novel encapsulation material can also be introduced providing high temperature stability and enabling high-power density. In terms of the material characteristics, the parameters such as low coefficient of thermal expansion (CTE), high glass transition temperature (Tg), long term thermal stability and encapsulation process optimisation are needed in order to generate module reliability enhancement. In this work, a half bridge 1200V/600A IGBT power module encapsulated with new Epoxy Molding Compound (EMC) and integrated metal baseplate (IMB) is investigated. The IEC standard reliability tests, such as high and low temperature storage, high temperature high humidity reverse bias (H3TRB) tests were carried out. Results show the EMC encapsulated IMB module performed well, and the electrical performance was not degraded. The leakage current was not increased during H3TRB test indicates that the modules are resistant to moisture of harsh environment.