Copper Wire Bonding in High Volume Manufacturing

Abstract

Wire bonding is still by far the dominant interconnection technology with about 90% market share. Copper wire bonding has achieved approximately 15% penetration within two years. Considerable amount of fundamental characterization has been performed to understand the nature of Cu wire bonding and even more analysis has been done in manufacturing to ensure reliable packages can be shipped. Here, some of the methodology of successful, high volume manufacturing will be described. Rigorous process optimization and product characterization are key and will be detailed. Supportive data from extended reliability testing demonstrates that 2 x the standard JEDEC life can be achieved. This is in part due to the very slow intermetallic growth rate and in part due to the proper choice of mold compound. The other elements are strict adherence and control of bonding parameters and rigorous clean room management which is also reflected in yields being equivalent to gold wire bonding.