Development of a fine pitch copper wire bond process for integrated circuit devices

This study focuses on the feasibility and reliability of using copper wires for fine pitch ball bonding as a replacement for gold wire bonding in a high volume production. The uses of Cu wire for thermosonic ball/wedge wire bonding presents several advantages, but there are some challenges that must be overcome for stable and reliable wire bond interconnections. The bond process was analyzed through DoE methods and we used destructive and non-destructive test methods to verify the bond interconnection. Furthermore, the reliability of the package could be pointed out due to accelerated life time tests. The paper reveals potentials of fine pitch copper wire bonding as a promising alternative for gold wires. But indeed, there are miscellaneous problems to vanquish to establish fine pitch copper wire bonding for high volume production.