When trying to screw in aluminum silicon carbide composites having through holes formed by conventional methods in components such as heat-dissipating fins, there has been the problem of the periphery of the through holes cracking. Further, even if there are no problems at the time of attachment, when the heat cycles are applied at the time of implementation, there has been the problem of cracks appearing in the hole portions. In addition, there was a problem that defects occur in appearance due to occurrence of shrinkage cavities and hole cavities during impregnation with metal.

The present inventors, after seriously considering the cause and means to prevent the occurrence of cracks and breakage in through holes and the periphery thereof, discovered that the cause of the occurrence of cracks and breakage lies in the defect of micro-cracks existing in the through holes and periphery thereof and that, while aluminum silicon carbide composites have high strength, they have insufficient toughness, which leads to destruction. The present invention was made in view of such circumstances, and provides a heat-dissipating component and a manufacturing method thereof that suppress damage such as cracks and breakage in through holes and the periphery thereof occurring when affixing the heat-dissipating component to other components and when actually being used after being affixed and that suppresses shrinkage cavities and hole cavities during manufacture.