Oxidation study of copper wire bonding

Copper wire bonding is the most effective alternative of gold wire bonding. As copper is more chemical reactive than gold, easier oxidation is one of the most major problem copper wire bonding encountered. Anti-oxidation technology must be used in copper wire bonding process. In general, there are two different ways to improve the anti-oxidation properties of copper bonding wire. One of which is injecting forming gas (FG) containing reducibility; the other is plated anti-oxidation metal coating on 4N pure copper wire. In this paper, we have investigated the performance of copper wire anti-oxidation technology. An optimized forming gas flow rate has been obtained for the pure copper wire. Evidences of anti-oxidation performance have also been shown for Pd-coated copper wire.