This study deals with the non-destructive test methods applied in the industry for SiC power metal-oxide-semiconductor field-effect transistors (MOSFETs). Scanning acoustic tomography (SAT) is used for testing SiC power MOSFETs, which are widely used in high-power electronic devices and electric vehicles. In this paper, we propose an automatic calculation method through SAT image conversion. Based on the automatically calculated delamination area, the device failure was determined, and the exact failure mechanism was identified. Existing verification methods require a lot of skills. In addition to measuring the electrical characteristics of SiC MOSFETs, internal structure analysis using X-ray and pass/fail judgment through SAM were performed. However, the auto-counting program SAT method reduces unnecessary verification methods and simultaneously detects the process of degradation of the SiC MOSFETs and the cause of internal failure. An SAT image first goes through a program that optimizes image recognition by adjusting the contrast and threshold. These preparation steps play an important role in accurately recognizing the delamination area. These steps and the verification method proposed to evaluate the reliability of SiC power MOSFETs are detailed in this article. The degradation process of the device is presented and discussed by applying an accelerated temperature cycling test and high voltage at the device’s gate terminal.
Source : Scopus preview – Scopus – Document details – Developed non-destructive verification methods for accelerated temperature cycling of power MOSFETs