Thermally conductive silicone rubber sheet comprising a thermally conductive adhesive layer

Abstract

One of the purposes of the present invention is to provide a composite heat-release sheet which is excellent in thermal conductivity and electrical insulation property and, at the same time, has all of sufficient adhesion to an actual machine, low thermal resistance, reworkability, and reliable adhesive strength. Another purpose is to provide a more convenient production process for the heat-release sheet. A thermally conductive silicone rubber sheet comprising at least one thermally conductive silicone rubber layer having a type A durometer hardness of 60 to 96 and at least one silicone adhesive layer, wherein the silicone adhesive layer is a cured product of an addition curable or peroxide curable silicone adhesive composition comprising (a) organopolysiloxane having at least one alkenyl group bonded to a silicon atom and having a phenyl group bonded to a silicon atom in such an amount that the percentage of the number of the phenyl group is 2 to 20%, based on the total number of substituents each bonded to a silicon atom, (c) thermally conductive filler having an average particle diameter of less than 10 μm and containing 0 to 3 mass % of particles having a particle diameter of 20 μm or more and 0 to 0.01 mass % of particles having a particle diameter of 40 μm or more, and (f) silicone resin comprising an RSiOunit and an SiOunit.