Temperature Effect on Breakdown Performance of Insulating Polymer Thin Films

Résumé

The effect of temperature on the breakdown performance of metallized capacitor-grade BOPP film was characterized using a large-area multi-breakdown measurement method. The measurements conducted in the temperature range from room temperature to 100 °C revealed a linearly decreasing trend in the characteristic 63.2 % breakdown probability after 60 °C and the presence of a smaller weak spot subpopulation. The weak spots remained relatively unaffected by temperature, and first breakdowns occurred in a seemingly statistical manner. The brief exposure to elevated temperature was considered as one explanation behind the variations in the number of weak points, but fluctuations in film quality and Weibull dynamics were seen are more probable explanations. The results demonstrate the possibility of multiple breakdown mechanisms and their different temperature-dependency, and demonstrate the high short-term breakdown strength of BOPP film even at high temperatures.