Study on Dielectric Characteristics of Nano-Al2O3 Composite Polyimide Film

The dielectric characteristics of nano-Al
₂
O
₃
composite polyimide film with Al
₂
O
₃
content of 5%, 10%, 12.5%, 15% and 20% in weight ratio were measured, respectively. The permittivity, dissipation factor and TSC peak temperature increase with increasing of the inorganic content. A percolation threshold corresponding to the content between 12.5% and 15% was discovered. With increasing the Al
₂
O
₃
content, breakdown strength decrease and conductivity increases. The active energy of composite films with different inorganic content, ranging from 0.58 to 0.89, was calculated by auto-separating technology