Method of making a capacitor winding

Disclosed is a method of making a capacitor winding by exposing a plasma polymerizable vapor of an organometallic compound to a plasma, moving a polymeric substrate beneath the plasma-exposed polymerizable organometallic vapor at a speed such that the metallic element in the organometallic vapors is deposited on the polymeric substrate to form a conducting layer, and carbon from the organic portion of the organometallic vapor is deposited on top of the conducting layer as a pinhole free highly cross-linked polymeric film. The substrate is then wound on a spool to form the capacitor winding. Also disclosed is apparatus useful for making the capacitor winding which consists of a substantially gas-tight reactor, a pay-out spool containing a wound-up organic polymeric substrate, a take-up spool positioned so that the substrate can move from the pay-out spool to the take-up spool unimpeded, and means for moving the substrate from the pay-out spool to the take-up spool. A monomer inlet is provided for admitting a vaporous monomer into the reactor over the substrate as it moves from the pay-out spool to the take-up spool and an effluent outlet is provided for drawing gases out of the reactor. A valve controls the admission of the monomer to the inside of the reactor and a vacuum pump applies a vacuum to the effluent outlet. A pressure gauge measures the vapor pressure inside the reactor and a radio frequency generator generates a plasma over the substrate as it moves from the pay-out spool to the take-up spool.