Heat dissipation component for semiconductor element

A heat dissipation component for a semiconductor element, the heat dissipation component comprising:

• a sheet-shaped aluminum-diamond composite containing 50-80 vol % of a diamond powder in which a first peak in a volumetric distribution of particle sizes occurs at 5-25 μm and a second peak occurs at 55-195 μm, and a ratio between an area of a volumetric distribution of particle sizes of 1-35 μm and an area of a volumetric distribution of particle sizes of 45-205 μm is from 1:9 to 4:6, the composite comprising an aluminum-containing metal as the balance;
• wherein
• the composite is covered, on both main surfaces, with a surface layer, having a thickness of 0.03-0.2 mm, containing 80 vol % or more of an aluminum-containing metal, two or more Ni-containing layers are formed on at least the surface layer, the Ni-containing layers being such that a first layer from the surface layer side is an amorphous Ni alloy layer having a thickness of 0.1-2.0 μm and a second layer is an amorphous Ni alloy layer having a thickness of 0.5-10.0 μm, furthermore, an Au layer having a thickness of 0.01 μm or more is formed as an outermost layer, and the amorphous Ni alloy layer forming the first layer has a peel strength of 50 N/cm or higher.