Wear optimized consumables for copper wire bonding in industrial mass production

Inhalt:
Copper wire as a bonding material for the top side connection of power semiconductors is highly desired. One current drawback in heavy copper wire bonding is the relatively low lifetime of the consumables. The bonding tool wear mechanisms and the corresponding factors are investigated in this contribution. Different approaches to reduce wear are tested in long-term bonding tests. Optimized bonding parameters and special tool material are two of these. Incorporating both, an immense improvement in tool lifetime of a factor of more than 15 was achieved. Wear and lifetime of cutter and wire guide are also examined. Additionally, the impact of bonding tool wear on different aspects of bond quality is addressed. It is also shown how wear can be monitored by machine process data recording and how a derived signal correlates to the actual wear status. These major advances in heavy copper wire bonding now make it a robust, reliable and efficient interconnection technology.