Approach to measure of space charge distribution in alumina material using PEA method under DC electric stress

In recent years, improvement of power density of a power semiconductor modules is required. However, it has been reported that dielectric breakdown occurs in the ceramic material used as an insulating substrate for the power semiconductor under the environment currently used. Therefore, to make it reliable and to improve its power density as the power module, it is necessary to elucidate the dielectric breakdown mechanism of the ceramic material. In this research, we tried to investigate the dielectric breakdown mechanism of the ceramic materials by measuring space charge accumulation characteristics using PEA method. However, it was found that the ceramic material a theoretically unexplainable behavior when shows it is measured using the PEA method. Therefore, we tried to estimate the charge behavior inside the ceramic material from a measurement result in multilayer samples composed of ceramic material and polymer material.