Wedge-bonding of wires in electronic device manufacture with reversible wedge bonding tool
In the manufacture of electronic devices ( 22, 22 ′), e.g. discrete semiconductor power devices or ICs, a reversible bonding tool ( 10 ) is used having a bonding tip or wedge ( 1, 2 ) at each of its opposite ends ( 11, 12 ). After extensive use of the wedge-tip ( 1 ) at one end ( 11 ) for bonding wires ( 21 ), the tip ( 1 ) is worn somewhat. Instead of needing to replace the bond tool as in the prior art, the tool ( 10 ) in accordance with the invention is then reversed to use the wedge-tip ( 2 ) at the opposite end ( 12 ) for bonding further wires ( 20 ′). Thus, a cost saving is achieved with regard to tool material.
1. A method of wedge-bonding wires in the manufacture of electronic devices, wherein:
a reversible bonding tool is used having a mount that engages an elongated shank in a first position between opposite ends of the shank, each end including a wedge-bonding tip,
and, after using the wedge-bonding tip at one end for bonding wires, the shank is reversed and engaged by the mount in second position between opposite ends of the shank to use the wedge-bonding tip at the opposite end for bonding further wires.
2. A method according to claim 1 , wherein the shank is made of tungsten carbide.
3. A method according to claim 1 , wherein the wires comprise aluminum or gold and are ultra-sonically bonded using a transducer coupled to the tool.
4. A method according to claim 1 , wherein the shank has the same cross-section at the first and second positions.
5. A method according to claim 1 , wherein the shank includes one or more guide holes for feeding the wires to the wedge-bonding tips.
6. A method according to claim 5 , wherein the one or more guide holes includes separate guide holes extending obliquely through each end of the shank.
7. A method according to claim 5 , wherein the one or more guide holes includes a capillary bore that extends from end to end through the length of the shank.