In order to evaluate the insulation of two-phase immersion cooling in the HV power electronic package. the insulation degradation of the dielectric interface induced by bubbles is investigated. In this paper. a test strategy with 50 Hz unipolar DC and AC combined voltage for partial discharge (PD) at boiling interface of AIN ceramic is proposed. https://www.ngetikin.com/special-pick-MVP4-Moisture-Vapor-Protection-Anti-Fracture-and-Noise-Reduction-Membrane-special-save/