HEAT-DISSIPATING SHEET FOR ELECTRONIC PARTS

PURPOSE:To form a heat transfer path having low contact thermal resistivity by impregnating and coating alumina paper, in which a microfibrillated organic fiber is paper-made to an alumina short fiber as a binding agent, with a synthetic rubber and molding alumina paper. CONSTITUTION:Alumina fibers, fiber diameters thereof extend over 100mum or less and fiber length thereof extends over not less than decouple as long as fiber diameters, are used as the principal ingredient, and alumina fibers are charged into a dispersive medium. Micro-fibrillated organic fibers are added as a binding agent and agitated at high speed, and the organic fibers as the binding agent are entwind to the surfaces of the alumina fibers, and fiber-made, thus obtaining alumina paper. The alumina paper acquired in this manner is impregnated or coated with a synthetic rubber, and molded to a sheet shape. A heat-dissipating sheet obtained in this manner has excellent electrical insulating properties and high thermal conductivity, and closely adheres to the heat-dissipating surface of a part homogenously by previously applying only external force. Accordingly, the heat-dissipating rubber sheet forms a heat transfer path having extremely low contact thermal resistivity.