Copper wire bonding - A maturing technology

Wire bonding has been the dominant mode of chip to substrate interconnection for many decades. The most common metal used has been gold which is rather malleable and very resistant to oxidation and corrosion. The surge in commodity prices over the last few years has prompted the introduction of copper as a lower cost alternative. While copper has some advantages electrically, thermally and mechanically, it presents also many challenges due to the mechanical properties as well as its propensity for oxidation and corrosion. Here, the successful introduction of fine diameter copper wire bonding into high volume manufacturing is described.