surface treatment of gold bumps for thermocompression bonding with low temperature

Trials were made for thermocompression bonding of gold contacts with different geometries. Prior to bonding, the surfaces were mechanically planarized and activated by means of an atmospheric plasma. These treatments enabled excellent shear strengths (about 50MPa) after bonding at a temperature of 160°C and a pressure of 100 MPa for short bond times (10s).