Heat sink and assembly or module unit

An assembly or module unit comprising:

• an electric or electronic power module;
• a ceramic-metal substrate, the ceramic-metal substrate consists of a ceramic layer and a metallization applied on each of the surface sides of the ceramic layer;
• at least one metal heat sink comprising at least one cooling element, which forms at least one cooling surface for mounting of the ceramic-metal substrate thereto, wherein the at least one cooling element of the at least one metal heat sink is provided with at least one compensating layer comprising at least one single layer applied directly to the at least one cooling surface, wherein the at least one compensating layer comprises Mo, W, Mo—Cu, W—Cu, Cu—CNF, Cu-diamond, carbon, carbon-nanofibers or combinations thereof;
• and wherein the metalization on one surface side of the ceramic layer of the ceramic-metal substrate is fastened to the at least one compensating layer via a solder layer, wherein a thickness of the at least one compensating layer is between 0.05 mm and 20 mm, and wherein the compensating layer has a thermal expansion coefficient that is lower than 10×106/° K and a thermal conductivity greater than 100 W/m° K and the compensating layer achieves equalization of thermal expansion coefficients of the ceramic-metal substrate and the cooling element in an area of a bond between them.