Heterogeneous Integration of Silicon-Based RC Snubber in SiC Power Module for Parasitic Oscillation Noise Reduction

Due to the increased switching speed and reduced device capacitance, the parasitic oscillation of the switching device has become the primary high-frequency electromagnetic interference (EMI) noise source in SiC converters. The dc-link snubber offers a potential to mitigate the noise in a cost-efficient way. However, the temperature limits and thermal de-ratings of the existing ceramic capacitor hinder the exploration of module-level integration. In this letter, a silicon-based RC snubber is designed to fit the working temperature of the power module. With the developed four-order damping and thermal coupling models, the iterative method is proposed to optimize the integration performance. The experiments validate the temperature stability of the integrated snubber. With the aid of the proposed RC snubber, the EMI noise induced by the parasitic oscillation in the prototype module is reduced by 7 to 22 dB compared with the nonsnubber module with ceramic decouplers.