Method for producing a heat sink having fins and a peripheral side wall

A method for producing a heat sink with fins and a peripheral side wall by extrusion, the method comprising:

• providing a die, which includes a base surface having openings, and a punch, which has a pressure surface, with a peripheral rebate being formed on the pressure surface of the punch;
• placing a semifinished product made of a first metal material into the die;
• releasably connecting a material layer made of a second metal material of a thermal conductivity which is higher than a thermal conductivity of the first metal material, to the pressure surface of the punch;
• bringing the punch into contact via the material layer with the semifinished product in the die;
• forming the heat sink by pressing the first metal material of the semifinished product by the punch through the openings of the die so as to form the fins and into the peripheral rebate of the punch so as to form the peripheral side wall, wherein the material layer is connected over an entire surface of the material layer to the first metal material of the semifinished product;
• releasing the punch from the material layer;
• and
• ejecting the heat sink from the die.