Direct CopperBonding (DCB) stands for direct copper coating. It is a process by which ceramics are coated with copper and in which the copper is firmly bonded to the ceramic.
In the production of copper-ceramic bonds, copper is combined with oxygen, which causes the melting point of copper oxide (Cu2O) to drop significantly below that of pure copper. The copper oxide coated with copper is placed as a thin copper foil on the ceramic surface and heated in a melt. During melting, the lower side of the copper foil, which consists of copper oxide, metallurgically bonds with the ceramic surface. Structures can be etched into the copper surface using etching techniques to form conductive paths on the ceramic substrate.