DIRECT BONDING OF COPPER TO ALUMINUM NITRIDE SUBSTRATES

摘要

A process for direct bonding a copper film to an yttria-doped aluminum nitride substrate comprises treating the substrate by preoxidation at elevated temperature to create an overlying thin film of Al2O3, followed by step cooling to a lower temperature. A copper foil of thickness between 1.0 and 4.0 microns and generally perforated or otherwise foraminous, is eutectically direct bonded to the substrate by the known direct bond copper (DBC) process. The resultant article exhibits high thermal conductivity, low permittivity and high mechanical strength. The peel strength of the copper film on the AlN substrate exceeds the peel strengths previously attainable in the industry.