A heat sink assembly in which the interface material is chemically bonded to both the heat source material and the heat sink material. The chemical bonding can lower the contact resistance that would otherwise exist using conventional adhesives to attach the heat sink to the heat source. The chemical bonding achieved between the respective materials can be, for example, ionic, covalent or metallic bonds, depending on the characteristic of the materials used to make the heat source, the interface material, and the heat sink.