Metallized polypropylene capacitors

El-Husseini MH, Venet P, Rojat G, Joubert C. Thermal simulation for geometric optimization of metallized polypropylene film capacitors. IEEE Transactions on Industry Applications 2003 38(3) 713—718. 

Electrical grade polymer films have now largely replaced the Kraft paper that was previously used in capacitor applications. Polypropylene and poly(ethylene terephthalate) are both used in capacitors as free films or metallized with a thin layer of aluminum. Other, newer materials for capacitor applications are made by metallizing polysulfone and polycarbonate films. 

Rabuffi M, Picci G (2002) Status quo and future prospects for metallized polypropylene energy storage capacitors. IEEE Trans Plasma Sci 30 1939... 

The dielectric materials used in power capacitors include paper, polypropylene, and mixed vacuums impregnated with mineral or synthetic oil. The most reliable dielectric material is polypropylene. The metal electrodes can be aluminum foils or thin metal films deposited onto the surfaces of the dielectrics. The reliabilities and lifetimes of power capacitors are always concerns because of the possibility of overheating. 

Polymeric materials are used as the basis of photoresists for making metal patterns on printed circuit boards, and also on the individual integrated circuit devices themselves. The circuit boards are made of various glass-fibre filled epoxides and polyesters, and are usually coated with other polymeric materials to prevent tarnishing and to improve solderability. The devices that are mounted on the completed printed circuit boards may have been manufactured using polymeric photoresists or have plastics such as polypropylene and polyester films in capacitors or epoxide resins in integrated circuits and transistors. The completed boards containing various devices are often then coated in another protective polymer. Finally, electrical connections are made... 

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