Investigations into the use of dielectric coatings in magnetic switches

The authors report the results of investigations into the possibility of using conformal dielectric coatings as a viable insulation option in high-speed magnetic switches. Most of the efforts have been directed at evaluating electrophoretic (EP) coating techniques. This process is analogous to electroplating and as such offers advantages over other coating techniques. A description of a continuous foil EP coating machine which is now operational is presented. In preliminary benchtop tests with a rounded probe on a single side of coated Metglas (nominal coating thickness of about 12 μm), breakdown voltages between 500 and 2600 V have been observed. Also discussed are etching techniques to remove the largest Metglas surface protuberances, experiments in applying chemical conversion coatings to Metglas for insulation, and experiments in photofabricating cooling channels on Metglas to aid in core thermal management in a manner that can be scaled for economical continuous processing