Heat sink composed of metal and method for the production of same

A tool for introducing a plurality of adjacent grooves (24) each having a depth of between 1 mm and 20 mm into a workpiece composed of metal during the course of the production of a heat sink composed of metal, having fluid lines (32) for conducting cooling fluid which are formed by the grooves (24) and which are separated by heat sink ribs (26) each having a width of between 0.2 mm and 0.8 mm, wherein the tool has a milling head (23) which is rotatable about an axis of rotation and which has a plurality of milling planes which are arranged next to one another, with each of the plurality of milling planes extending in a cross-axial manner and in each of which milling teeth (31) are arranged, wherein the milling teeth (31) of adjacent milling planes are spaced apart from one another in an axial direction at the distance of adjacent grooves (24) to be produced, and wherein the milling teeth (31) are either arranged on milling discs (25) of the milling head (23) which are arranged next to one another in the axial direction, or are part of a milling drum of the milling head (23), and are structured for producing the adjacent grooves (24) each having the depth of between 1 mm and 20 mm.