Polymer Capacitor Dielectrics for High Temperature Applications

Much effort has been invested for nearly five decades to identify and develop new polymer capacitor dielectrics for higher than ambient temperature applications. Simultaneous demands of processability, dielectric permittivity, thermal conductivity, and dielectric breakdown strength dictated by increasing high power performance criteria limit the number of available materials. The present review first explains the advantages of metallized polymer film capacitors over the film-foil, ceramic, and electrolytic counterparts and then presents a comprehensive review on both past developmental effort of commercial resins and recent research progress on new polymers targeted for operating temperature above 150 degrees C. Some historical background and discussion on the limitation of the commercially available polymer film dielectrics for high temperature applications are also given. In many cases, further development of promising polymers that appear to possess all or most of the important criteria is limited by lack of large scale market incentives but could be of great value to niche applications in the military or aerospace realm.