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 measured, 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 current 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