High Velocity Oxygen Fuel Sprayed Insulation Coatings for Applications in High Power Electronics

Abstract

Abstract Electrically insulating coatings featuring high dielectric strength, high electrical resistance and high thermal conductivity are essential for applications in high power electronics. The capability of HVOF-sprayed coatings for high power electronic components based on 20 different powders was investigated in this study. The powders used are aluminum oxide ceramics containing additives of chromium oxide, titanium oxide and magnesium oxide. Key result of this study is that both, pure alumina (Al2O3) and one class of spinel (Al2O3 - 28MgO) meet the requirements for electrical insulation. In order to reach high resistivity, the insulation coatings should be sealed subsequently. The amount of impurities, such as Na2O or Fe2O3 must be less than 0.1%.