Insulating coatings for high-performance electronic components produced by thermal spraying considering electrical and mechanical characteristics

摘要

Thermal and cold spraying provide a large potential in coating of parts and production of high-performance electronic components. Such components are made of a substrate and a bond coat on which an adhering insulating material and a metallization, such as circuit paths, can be applied. The components have to fulfill certain requirements regarding their mechanical and electrical properties to get ready for the market. The substrate, in industry commonly used aluminum has to provide high thermal conductivity. Furthermore a good adhesion between substrate and insulating material is required. The insulating material has to provide a very high electrical resistance to ensure low cross currents. Furthermore a high dielectric strength is necessary which depends for example on the porosity and phase stabilization of the coating. Industrial alumina is commonly used as an insulating material. The adhesion between the electrically conducting and the electrically insulating coating can be improved by a primer coating significantly. In this work the mechanical and electrical properties of insulating coatings were investigated. Especially the alternative applications of alumina enriched with titanium oxide and alumina enriched with chromium oxide were considered as well as the sealing of the pores of the coating which allows the use in high-performance electronics.