Abstract: A wire bonder for making electrical connections from semiconductor chips to conductors on a lead frame includes a fault sensing system to detect a failure of the ball bond at the chip pad as well as the lead bond. Pad bond failure is detected by providing a wire feed sensor and a logic element for determining whether the wire is being fed when the bonding tip is moved from the chip to the lead. There is no wire feed if the pad bond fails. Lead bond failure is detected by clamping the wire after the lead bond is made and pulling on the wire to either break off the tail at the bond or pull the bond loose from the lead. Then the clamp is released momentarily so that if the tail has not broken free, an extra length of wire will be pulled from the tip. The extra length of wire is sensed by an electronic flame off torch monitor.