High-Temperature Polymer Film Capacitor Development Published Oct. 27, 2009 By Tom Brown Propulsion WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- Engineers from the Air Force Research Laboratory, Universal Technology Corporation, and Brady Worldwide, Inc., reached a significant milestone in developing polymer film capacitors for high-temperature (200°C) power systems. The engineers were able to demonstrate the industrial-scale, roll-to-roll manufacturing and handling of high-temperature (Tg ~330°C) fluorene polyester film at uniform thicknesses less than 5 µm, which was successfully utilized in the fabrication of wound 7-11 µF capacitors at yields up to 100%. This achievement was the result of a thorough study geared towards optimizing the processing and incorporation of a proprietary filler material into fluorene polyester polymer film as a means to lower the coefficient of friction by an order of magnitude. This enhanced material processing capability led to the successful transition of the fluorene polyester film to a large-scale coating/metallization production system at Steinerfilms, Inc., which is a notable step in making fluorene polyester film commercially available at sufficient lengths and quality for the fabrication of miltary-grade polymer film capacitors. Certain fluorene polyester film, based on composition, was then wound by Dearborn Electronics at a high yield to fabricate 7-11 µF capacitors with a breakdown strength >200 V/µm, a low dissipation factor (~1 %), and a high insulation resistance (>25,000 MΩ). AFRL initiated a demonstration with Hamilton-Sundstrand in order to evaluate fluorene polyester capacitors alongside silicon carbide power modules in a nonlinear inverter for an advanced aircraft. The demonstration is a key component for the AFRL Integrated Vehicle Energy Technology and Adaptive Versatile Engine Technology development programs, which improve the thermal management capability in advanced aircraft.