Damage characterization study using piezoresistive stress sensors for wire bonding process

Provide the sensor responses for various bonding power from 76 DAC to 200 DAC and use optical microscopy images, Current-Voltage curves and stress responds to find the regions of bondable and bond failures. When the bonding power increased, the stress magnitude of σx, σy and σz all increased. Good bonding could be achieved with bonding power less than 100 DAC. When bonding power is more than 100 DAC, bond failure or sensor damage could be occurred. The bond failure mechanisms include that under Al pad crack and Silicon cratering after wire bonding.