Assessing the reliability of SiC MOSFET through inverter-like accelerated test vs. power cycling test

Abstract

Silicon carbide (SiC) MOSFETs are known for their superior performance compared to traditional silicon devices, making them well-suited for a wide range of applications in power electronics. However, there is a lack of long-term reliability studies for SiC MOSFETs under real-world operating conditions. This article introduces an innovative inverter-like accelerated test (IAT) and compares it with the standard power cycling test (PCT) to thoroughly assess the degradation mechanisms and reliability of SiC MOSFETs. The IAT is designed to replicate the operational conditions of an inverter, providing a more realistic evaluation of the long-term performance of the SiC MOSFET. There are some differences in the principles of these two accelerated tests (ATs). The paper provides detailed insights into these differences and the methodologies used, including the test bench design and junction temperature estimation, and presents the experimental results. The findings highlight significant differences in the degradation behavior observed under IAT and PCT conditions and the lifetime evaluation, underscoring the necessity for realistic testing protocols to ensure reliable lifetime predictions for SiC MOSFETs in practical applications.