Scale-up of RF Plasma Treated Capacitors for High Energy Density Applications

Work by M. Binder and the army ETDL has shown that the RF plasma treatment of capacitor films, electrode foils and wound rolls, can result in significant and in some cases dramatic improvements, in the electrical breakdown strength of certain capacitor films and capacitor rolls. In this investigation we will demonstrate potential commercial applications of the RF plasma treatment that will allow this technology to be licensed by film producers and capacitor manufacturers. In order to identify the commercialization potential of the film surface treatment, a high power hollow cathode RF reactor will be used to reduce the treatment time so that the process can be used to treat webs of film that are moving at production-like speeds. Contact angle, adhesion and ESCA analysis will be done on the surface of the films, to relate the data to the work done by the ETDL and further quantity effects of the O2 and CF4/02 plasmas. Treated films will be metallized with and with out exposure to air, and the self healing characteristics will be studied. Aluminum and tin foils with widths varying from 0.25" to 6.0" will be plasma treated and treated in wound capacitors, to determine the relationship of the foil edge treatment to the breakdown strength of the capacitors. Wound rolls will be plasma treated in a box etcher both by mechanical fixuring and by placing the rolls inside a cage that is rotating in the plasma chamber. The latter method will allow large quantities of small capacitors to be treated uniformly at a low enough cost, that will make this process cost effective even for marginal enhancements in the dielectric strength of the parts.