Fast Electrothermal Estimation of Power Semiconductor Devices Based on Complex Mission Profile

In the field of power semiconductor devices, thermal stress estimation is of substantial importance in the application of lifetime estimation, over-temperature protection, and other fields. However, conventional thermal stress estimation methods of power semiconductor devices perform imprecise and inefficient. First, the external thermal path model of target device is always neglected, which may influence the thermal performance of the inner device and the whole system. Second, the electrical and thermal stress mission profiles are completely separated, and the low-integrated electrothermal model may over-occupy calculation resources. In this paper, a fast electrothermal estimation of power semiconductor device based on complex mission profile is proposed. Neglecting the thermal-insensitive electrical stress in high-frequency bandwidth, the electrical stress is remodeled as the big-signal model. Considering the external thermal paths, a frequency-domain thermal model is applied, for the correction of heat flow. The electrical and thermal models are highly integrated with a signal transmission interface, and all the electrothermal models are realized through digital filters in digital processors. Experiment results are provided to validate the effectiveness of the proposed method.