| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a plurality of protruding fins from a heat sink crude material, and simply and accurately form a thick part of a cooling substrate of a predetermined thickness on the downside. SOLUTION: A heat sink crude material, made of an aluminum extrusion material, has a cooling substrate thick part forming part 5, fin-forming parts 2 of the number corresponding to a protruding fin column provided integrally on the upside of the thick part forming part 5, a thin part 1 provided on one side of the thick part forming part 5, a thick part level reference protrusion stripe 3 provided on an upper surface of the thin part 1 and being flush with the surface of the thick part forming the upper end, and the heat sink crude material is molded, the fin-forming part 2 is cut and arisen from an upper end level of the thick part level reference protrusion stripe 3, to form a plurality of fins, and also a thick part of a predetermined thickness is formed on the downside of these fins.</p> |
