Space charge formation in polyimide/carbon compound film for electronics devices

With the specimens disperse carbon black of same volume in polyimide film, we investigated dispersion state of carbon black, electrical conductivity and space charge distribution. The result was confirmed that electrical conductivity of polyimide films was indeterminable only volume of carbon black. About space charge distribution, in all specimens of polyimide films the plus hetero charge occurred much, in each different specimens of electrical conductivity the occurrence volume was different. The distribution state of carbon black was not different in the result of SEM observation. We guessed the electron from polymer structure had influence on the electrical conductivity. We confirmed the occurrence of space electric charge at an applied voltage pulse of 10-500 ms intervals.