Conductivity spectroscopy and conduction current measurements of polyimide thin films during high temperature aging

Development of electronic devices, operating under high temperature (>;200°C), involves the use of appropriate dielectric materials for the components packaging and its electrical insulation. Aromatic polyimides (PIs) are well known for their good thermal, electrical and mechanical properties and appear also as potential candidates for high temperature power electronic device insulation. Many studies have been led on electrical properties in PI using metal insulator-metal structures (MIMS) by transient current (TC) experiments and electrical conduction vs. temperature has been also investigated by dielectric relaxation spectroscopy (DRS). After having investigated the dielectric properties of the BPDA/PDA PI for temperature above 200°C it seems important to understand the effect of aging in different atmospheres at the desired temperatures, on the dielectric properties of the material in order to validate its uses in high temperature applications. In this paper, a comparative study of the aging effect in two different atmospheres, on the dielectric properties measured by DRS at very low field and by TC under DC fields between 100 and 800 kV/cm at 300°C will be presented.