Materion Corporation Microelectronic Ceramic Packages Direct Bond Copper

High purity copper sheets 0.010" or 0.012" (250 or 300 microns) thick can be directly bonded to BeO or alumina substrates by the direct bond copper process, which involves the materials being bonded by a ternary phase of Be-Cu-O and Al-Cu-O. The result is a strong, hermetic bond of thick copper for applications requiring low thermal resistance and high current-carrying capabilities. Plates of alumina or BeO are blanket bonded on both faces with Cu, and then the Cu is photoetched into the desired pattern. After patterning, the copper can be plated with Ni and Au.