Thermal diffusion sheet and method for positioning thermal diffusion sheet

1. A thermal diffusion sheet, comprising:

a graphite sheet for diffusing heat generated by a heat emitting body;

a polymer film provided on the graphite sheet;

a heat conductive rubber provided on the graphite sheet; and

a positioning portion for carrying out positioning relative to the heat emitting body,

wherein the polymer film includes a hole provided in the polymer film for placing the heat conductive rubber,

wherein the heat conductive rubber is placed in the hole, and thus placed so as to make contact with the surface of the graphite sheet without the polymer film being present therebetween.

2. The thermal diffusion sheet according to claim 1 , wherein an upper adhesive layer and a lower adhesive layer are provided on an upper surface and a lower surface of the graphite sheet, respectively, and

wherein the polymer film is pasted to the graphite sheet through the upper adhesive layer, and the thermal diffusion sheet is pasted to the heat emitting body through the lower adhesive layer.

3. The thermal diffusion sheet according to claim 2 , wherein the positioning portion is a hole through the polymer film and the upper and lower adhesive layers, the heat emitting body is placed on a substrate, and the positioning portion is engaged with a projecting structure placed on the substrate.

4. A method for positioning the thermal diffusion sheet according to claim 1 relative to a heat emitting body,

wherein the positioning of the thermal diffusion sheet relative to the heat emitting body is carried out by engaging a structure placed in close proximity to the heat emitting body with the positioning portion.