Parylene Deposition Improving Dielectric Properties of Biaxially Oriented Polypropylene Capacitor Film

In this paper, a surface modification method based on parylene F (PF) deposition is proposed to optimize the insulation properties of polypropylene (PP) capacitor film. The experimental results show that 5 % thickness of parylene coating can reduce the leakage conductivity of the PP sample by 35 % to 86 % at different temperatures. The breakdown strength is increased by 30 % to 360 %. The deposition of PF layer can capture the injected charges and improve the voltage resistance of the films. However, when the coating thickness exceeds 15 %, the insulation performance deterioration occurs, which is attributed to the intrinsic charge excitation in the PF.