Dielectric breakdown of polyimide films: Area, thickness and temperature dependence

作者：Sombel Diaham, Samir Zelmat, M.L. Locatelli, Sorin Dinculescu, Michaël Decup, Thierry Lebey · 发表于：IEEE Transactions on Dielectrics and Electrical Insulation · 年份：2010 · DOI：10.1109/tdei.2010.5411997 · 被引用次数：208 · 研究领域：High voltage insulation and dielectric phenomena、Dielectric materials and actuators、Power Transformer Diagnostics and Insulation

Changes in the dielectric breakdown field of polyimide (PI) films have been studied from 25 to 400°C under dc ramps. Both the area (from 0.0707 to 19.635 mm2) and thickness (from 1.4 to 6.7 ¿m) dependences of the dielectric breakdown field have been carried out using the Weibull distribution function. The 63%-breakdown field value (i.e. the ¿-scale parameter) of PI shows a decrease with increasing area, thickness and temperature but always remains above 2 MV/cm. The ß-scale parameter of the distribution shows a typical decrease with increasing area, however, it exhibits an increase with increasing thickness. This 'curious' behavior is discussed on the basis of the percolation theory. No temperature-dependence is clearly observed. Moreover, physical interpretations are carried out using the pre-breakdown current analysis.