A heat sink that is particularly suitable for semiconductor components is made from a diamond-containing composite material. In addition to a diamond fraction amounting to 40-90% by volume, the composite material also contains 7 to 59% by volume copper or a copper-rich phase (with Cu>80 at. %) and 0.01 to 20% by volume boron or a boron-rich phase (with B>50 at. %). The bonding of copper to the diamond grains can be considerably improved by the addition of boron, with the result that a high thermal conductivity can be achieved. The heat sink component is preferably produced with an unpressurized and pressure-assisted infiltration technique.