Technologies for Applying Current-Heat-Conducting Copper Coatings on Corundum Substrates

Abstract

AbstractThe paper is devoted to the development of technological processes for the deposition of copper current-heat-conducting coatings on corundum substrates made of ceramics of the VK-100 type using Almatis 1200 alumina modified with the addition of MgO. A number of technological modes of applying current-heat-conducting coatings on corundum substrates are described, including the technology of coating by the method of molybdenum-manganese metallization and brazing; technology for joining copper foil with ceramics by thermomechanical loading on an activated metallized substrate; technology of direct connection of copper foil with corundum substrate (DBC - technology). It has been shown that high peel strength of a metallization layer based on Mo-Mn paste with corundum ceramics is achieved by using the technology of applying metallization in two layers, at that the first layer additionally contains titanium hydride, and the second layer additionally contains silicon and molybdenum oxide. Copper coating by thermomechanical loading on an activated metallized corundum substrate includes the following operations: applying an adhesive layer based on molybdenum and manganese and a layer of powdered copper on top and bottom of the ceramic substrate, applied by cold gas-dynamic spraying, followed by heat treatment. Reliable adhesion of copper foil to corundum ceramics using the DBC technology is due to the interaction of copper oxide with corundum with the formation of spinel in two forms CuAl2O4 and CuAlO2.The developed technological modes provide products with high performance properties in terms of adhesion reliability, electrical and thermal characteristics.KeywordsCurrent-heat-conducting copper coatingsCorundum substratesMolybdenum-manganese metallizationCold gas-dynamic sprayingDBC - technology