Evaluation of $V_{\rm ce}$ Monitoring as a Real-Time Method to Estimate Aging of Bond Wire-IGBT Modules Stressed by Power Cycling

The supervision of semiconductor power devices in operation demonstrates an obvious interest to improve the operating safety of electronic power converters used in critical applications. Unfortunately, this is a significant challenge due to the variability of stress conditions on the one hand and to the difficulty to implement accurate measurement systems in power stages on the other. Using VCE measurement as a real-time supervision method is evaluated here by using aging test results obtained on insulated gate bipolar transistor (IGBT) modules stressed by power cycling. These results are related to the aging of bond wires and metallization, on the top part of the module. Results were obtained in original test benches whose characteristics are overviewed briefly in the first part of this paper, along with a description of test conditions. The second part presents selected results extracted from a larger work and focusing on the VCE evolution with respect to degradations of the module's top part. Their analysis highlights the potential of VCE measurement. The last part proposes the principle of a specific system able to achieve real-time VCE supervision in the test benches in operation.