Conduction Current Characteristics of Nano-inorganic Composite Polyimide Films

The field dependent conduction current of nano-Al2O3 and nano-SiO2 composite polyimide films, with Al2O3 content of 5%, 10% 12.5%, 15% and 20% and SiO2 content of 5%, 15% and 30% in weight ratio, were me. asured, respectively. The conduction current of 10% Al2O3 content film after corona aging was also measured. The results show that, with increasing the inorganic content, the conduction current of composite film increase and the electric degradation thresholds decrease, after corona aging, the conduction cur-rent and electric degradation threshold decrease. The breakdown strength of nano-Al2O3 composite polyimide film decreases and the conductivity increases with the increasing of the inorganic content.