Observation of Space Charge Behavior in Polyimide Film under DC Stress with Visible Light Irradiation

Space Charge behavior in polyimide film under dc stress with visible light irradiation was carried out using a newly developed measurement system of the pulsed electro-acoustic (PEA) method. The PEA method has been widely used to observe a space charge distribution in various solid dielectric materials. We applied the method to investigate the interaction of visible light irradiation on space charge formation in dielectric materials under DC stress. It is well known that a property of the conduction in dielectric materials is affected by the irradiation of light. However the relationship between the space charge and the irradiation of light haven´t been clear yet. To observe the effect of the light irradiation on the space charge distribution in polyimide film, we measured the time dependent space charge distribution under the irradiation of the visible light using three kind of LED. From the results, it is found that the space charge formation in the polyimide film under DC stress with irradiation of visible light is affected by the energy of the irradiated light.