Influence of heat-treatment of traps examined by using the thermally stimutated current and the dielectric characteristics of carbon-black-filled polyimide film

The influence of heat-treatment on the thermal deterioration of carbon-black-filling polyimide film (CBPI film) was examined by thermally stimulated current (TSC) measurement. CBPI film used for experiment had about 0.01 of tan δ and about 5.7 of relative permittivity. The conductivity of the film was about 10¹⁶ S/cm and was stable for a temperature change. When CBPI film was heat-treated, the conductivity became thermal active form. The thermal deterioration of a carbon black structure was occurred, because the tan δ was increased about 20 times in comparison with that of the film before the heat-treatment. Four kind of charge traps were also observed in the TSC spectrum of the CBPI film.