Investigation of an approach for the determination of the current State-of-Health and improvement of service life in power modules

One of the main challenges in power electronics (PE) is the lifetime of the components and finding ways to monitor reliability during operation. In this paper, an approach to determine the State-of-Health (SoH) of PE components during testing and operation is introduced, focusing on the delamination of the die attachment as an exemplary type of degradation. The approach involves the creation of a virtual representation (FE model) of the real power module as a basis for a digital twin. Mapping of the delamination based on the applied current loads and environmental conditions must be taken into account. The active power cycling test, which is widely used for reliability assessment, enables the comparison of the digital twin with experimental data. The aim is to determine the SoH through this comparison. Based on the determined SoH together with the known data from the test, the remaining useful life can be estimated. If the criterion for the necessary remaining service life is not met, the digital twin can trigger adjustments of the acting operating loads that enable the extension of the service life to ensure the fulfillment of the current mission as planned originally, based on the SoH trends determined previously.