Ultrasonically joining apparatus and ultrasonically joining method

摘要

A cooling device has a radiator plate and a corrugated fin for cooling an electrical component. In a manufacturing process of the cooling device, a symmetrically constructed tool section presses the radiator plate and the fin against an anvil. The radiator plate has an attaching portion where an electrical component is attached. Knurled surface for preventing a slide is formed on the tool section only at a surrounding area to prevent a deformation of the attaching portion. The tool section and the radiator plate vibrate ultrasonically in a longitudinal direction of corrugations of the fin to prevent a crack on the fin.