Apparatus and method for conductive metal ball bonding with electrostatic discharge detection
View Patent ↗An apparatus for bonding a conductive lead to a conductive terminal of a device by the use of a conductive metal ball is disclosed and claimed. A ball-forming wire comprises a first conductive metal having a first melting temperature. A clamping surface has a closed position in contact with the ball-forming wire. A wire-clamping actuator is coupled to the clamping surface and is electrically connected to a clamping signal source. A sparking pin comprises a second conductive metal having a second melting temperature higher than the first melting temperature. The sparking pin is electrically connected to a power source. A current detection transformer includes a magnetic core at least partially encircling the ball-forming wire. An analyzing circuit is electrically connected to the current detection transformer.
1. A method for bonding a conductive lead to a conductive terminal of a device the method comprising:
bringing proximate a pin and the distal end of a conductive metal wire;
energizing the pin to temporarily form an electrical arc between the pin and the distal end of the conductive metal wire;
bringing adjacent the distal end of the conductive metal wire and the conductive terminal of the device;
directing bonding energy to an interface between the distal end of the conductive metal wire and the conductive terminal of the device;
clamping the conductive metal wire; and
monitoring electrostatic discharge in the conductive metal wire.
2. The method of claim 1 wherein the conductive metal wire passes through a capillary tube, and further comprising at least partially evacuating the atmosphere in the capillary tube.
3. The method of claim 1 wherein the device is a magnetic recording head transducer.
4. The method of claim 1 wherein the conductive metal wire comprises gold.
5. The method of claim 1 wherein monitoring further comprises broadening peaks in a signal from a transformer having a magnetic core at least partially encircling the conductive metal wire.
6. The method of claim 5 wherein monitoring further comprises digitally sampling the broadened peaks.
7. The method of claim 1 wherein monitoring further comprises displaying a signal from a transformer having a magnetic core at least partially encircling the conductive metal wire when the distal end of the conductive metal wire is adjacent the conductive terminal of the device.
8. The method of claim 1 wherein bringing proximate the pin and the distal end of the conductive metal wire comprises moving the pin.
9. The method of claim 1 wherein bringing proximate the pin and the distal end of the conductive metal wire comprises moving the conductive metal wire.
10. The method of claim 1 wherein bringing adjacent the distal end of the conductive metal wire and the conductive terminal of the device comprises moving the conductive metal wire.
11. The method of claim 1 wherein bringing adjacent the distal end of the conductive metal wire and the conductive terminal of the device comprises moving the device.
12. The method of claim 1 wherein directing bonding energy includes directing ultrasonic waves to the interface along a wave transmission path.
13. The method of claim 1 wherein directing bonding energy comprises heating the interface.
14. The method of claim 1 wherein clamping includes changing an electrical potential across a piezoelectric material.