Evaluation of Electrical Model Parameter Changes in SiC Power MOSFETs During Power Cycling Test

Abstract

Silicon carbide (SiC) power modules have witnessed significant advancements in recent years, and adopted in a wide range of power electronics applications. The long-term reliability of SiC power modules is key for the replacement of conventional Si power modules. Although several reliability test methods for SiC power modules have been conducted, SiC MOSFETs still have concerns regarding changes in electrical characteristics owing to electrical or thermal stresses. It can cause errors in junction temperature estimation, especially in the power cycling test, which utilizes the electrical characteristics of MOSFETs to detect mechanical deterioration of power module packages. In order to accurately assess the long-term reliability of power module packages, it is necessary to clarify a suitable test method to avoid any electrical degradations of SiC MOSFETs. This paper experimentally investigates the changes in electrical model parameters of several SiC MOSFETs in power cycling tests. The investigation focuses on the influences of the self-heating method on large forward and reverse current flows through the SiC MOSFET.