Abstract: A heat sink according to the present invention is configured to comprise: a plurality of heat dissipating fins having at least bottom portions which form a heat receiving surface thermally connected to a heat generating electronic component; and a heat-transfer connecting member for, by passing through each of said plurality of heat dissipating fins arranged in parallel, connecting said plurality of heat dissipating fins in such a manner that said bottom portions form said heat receiving surface.

Abstract: A heat sink according to the present invention is configured to comprise:

Abstract: The present invention relates to an aluminum alloy for a magnetic disk substrate having a composition consisting of, by percent by weight, 2.0 to 6.0% of Mg, 0.05 to 0.15% of Cu, 0.10 to 0.30% of Zn and 0.05 to 0.12% of Zr, wherein the contents of Cu, Zn and Zr satisfy the relationship: 0.15%.ltoreq.2Cu+6Zr-3Zn.ltoreq.0.32% (wherein Cu, Zr, and Zn respectively represent their contents in terms of percent by weight), and the composition further consists of one or both of 0.01 or more to less than 0.05% of Cr and 0.01 or more to less than 0.05% of Mn, impurities consisting of Si, Fe and Ti, which are respectively regulated to be 0.05% or less, 0.05% or less, and 0.02% or less, and other inevitable impurity elements respectively regulated to be 0.02% or less, with the remainder being Al. The present invention also relates to a clad material for a magnetic disk substrate, in which one or both surfaces of a core material, consisting of at least less than 3.