Methods for making thermally cooled electronic cards are disclosed. The method comprises providing a card (2, 3i) of any kind to be covered with a rigid heat sink (1) shaped to fit and attached to the card (2, 3i), and forming said heat sink (1) in such a way that it fits as closely as possible the shape of the printed circuit (2) having components (3i) on one or both sides thereof, whereby the surface thermal coupling between the sink (1) and the card (2, 3i) may be increased, by means of an optical sensor which preferably operates with a laser beam. Such a heat sink may thus be manufactured more quickly.