Formation of C u A l O 2 at the C u/ A l 2 O 3 Interface and its Influence on Interface Strength and Thermal Conductivity

The criteria for the formation of a C u A l O 2 reaction phase at the C u/ A l 2 O 3 interface are explored. Oxygen solutes up to 2 wt% were introduced into the copper first. The bonding was carried out at 1075°C. The reaction phase was observed only when the oxygen solute in copper before bonding was higher than 1.3 wt%. The C u A l O 2 phase is polycrystalline and covers only part of the interface. The C u A l O 2 grains interact with the crack, which improves the interface strength. As C u A l O 2 is not continuous at the interface, the thermal conductivity of the A l 2 O 3 / C u/ A l 2 O 3 laminate is affected little.