Patent ID: 8273209

Claim:
A method for mounting a thermal diffusion sheet on a radiator plate, the thermal diffusion sheet comprising a graphite sheet and first and second thermally conductive adhesive layers attached to principal surfaces of the graphite sheet, the method comprising: attaching a first surface of the first thermally conductive adhesive layer having a substantially same size as the graphite sheet to the radiator plate and a second surface of the first thermally conductive adhesive layer to a first surface of the graphite sheet; and sealing end faces of the graphite sheet and end faces of the first thermally conductive adhesive layer attached to the first surface of the graphite sheet by attaching the second thermally conductive adhesive layer to a second surface of the graphite sheet and attaching peripheral portions of the second thermally conductive adhesive layer to the radiator plate, wherein the second thermally conductive adhesive layer on the second surface of the graphite sheet is larger in size than the first thermally conductive adhesive layer on the first surface of the graphite sheet, and an entire periphery of the second thermally conductive adhesive layer on the second surface of the graphite sheet lies outside the graphite sheet, adhesive strength of the first and second thermally conductive adhesive layers on the first and the second surfaces of the graphite sheet, respectively, after exposure to 40° C. for 168 hours is reduced by no more than 20% relative to initial adhesive strength, and a hardened material of a polymer component included in the first and the second thermally conductive adhesive layers on the first and the second surfaces of the graphite sheet, respectively has a thermal conductivity of 0.6 W/m·K or more.