Active Power Cycling Test Bench for SiC Power MOSFETs—Principles, Design, and Implementation

Abstract

One way to achieve the best in class reliability is the implementation of a Design for Reliability methodology into the design process in order to estimate the lifetime of each individual critical component, based on proper reliability models for failure modes. The main drawback of the above-mentioned approach is that it relies on handbook-based reliability models, which usually are only accurate for particular components. This fact causes the necessity to develop a testing procedure for SiC power MOSFET, to determine its reliability model parameters. Such model could be further implemented in the Design for Reliability methodology for the high performance power supply design process. In this paper, a cost effective and industrial friendly laboratory setup for Active Power Cycling of SiC power MOSFETs in SOT-227b housing is presented. By this example, various control strategies for accelerated lifetime testing, degradation indicators for wear out condition monitoring and junction temperature estimation methods are compared on their impact on test results and complexity in either laboratory setup and its maintenance procedure. Technical issues related to the start-up of Active Power Cycling test and failure detection algorithm are discussed. Finally, test results for SiC power MOSFETs subjected to over 63355 power cycles are presented.

Real-Life Mission Profile-Oriented Lifetime Estimation of a SiC Interleaved Bidirectional HV DC/DC Converter for Electric Vehicle Drivetrains

“…As this paper is focused only on SiC-based technology, the SiC power module failures need to be investigated thoroughly. There are two fundamental modes for SiC power modules: (a) wear-out failures and (b) catastrophic failures, as mentioned in [7], [8]. Packaging failures constitute wear-out failures, where the failure is a consequence of accumulated damage due to the temperature, threshold voltage, vibration, and humidity stresses on the SiC power module.…”

“…Both of them can be modelled as 2-D LuT forward current (iF(t))-junction temperature (Tj) dependent elements. The instantaneous conduction losses of a body diode can be calculated by (8).…”

WBG-Based PEBB Module for High Reliability Power Converters

“…• Output capacitor (C1). Either GaN-based devices or SiC-based devices are susceptible to the package-related issues, or so-called fatigue-like failure modes [15], like:…”

High-Frequency Non-Invasive Magnetic Field-Based Condition Monitoring of SiC Power MOSFET Modules

“…This limitation becomes more apparent in high frequency circuit designs considering the nominal higher switching frequency in WBG devices. This is mainly due to the fact that the measurement system based on the electrical parameters with galvanic connections are prone to EMI and highfrequency switching transients [13,14,17].…”

“…(2) In the high switching frequency operation (20 kHz and above), the overall switching losses are not just related to the health of e.g., a SiC power MOSFET itself, and can be related to the degradation of the driver circuit, environmental conditions, load, etc. [17]. Therefore, in monitoring the degradation over a long period, estimation of the device degradation using a measurement tool prone to degradation itself is unsatisfactory.…”