Abstract: Cu-Cu₂O eutectic bonding of copper to Al₂O₃ was investigated. The highest peel strength was 11.5kg/cm for the specimen prepared at 1070℃ for 3h in nitrogen atmosphere. Oxygen promoted the wetting between
copper and Al₂O₃ greatly. Cu[O] melt reacted with the alumina and formed a continuous CuAlO₂ layer, which enhanced the peel strength of the joint. On
cooling, the solidification front moved from the solid copper towards alumina, and Cu₂O precipitated from the Cu[O] melt. When the solidification front met
the CuAlO₂ layer, liquid-aided reaction completed and a reliable bond was achieved between the copper and Al₂O₃ substrate.

Key words: direct bonded copper(DBC), peel strength, interfacial product