Patent ID: 7565995

Claim:
A wire bonding machine, comprising: a bond head adapted to manipulate a wire, the bond head comprising a wire braking apparatus and a fixed portion; the wire braking apparatus comprising: a first bearing member comprising a first race adapted to rotate about a first rotational axis of the first bearing member, wherein the first race has a first outer end with a first generally concave-shaped portion, wherein the first race has a first side and a second side, wherein the first and second sides of the first race face opposite directions along the first rotational axis; a second bearing member comprising a second race adapted to rotate about a second rotational axis of the second bearing member, wherein the second race has a second outer edge with a second generally concave-shaped portion, wherein the first outer end of the first race faces the second outer end of the second race; and a first piezoelectric element located between the first bearing and the fixed portion of the bond head, the first piezoelectric element being configured so that a first tolerance gap exists between the first piezoelectric element and at least one of the first race and the fixed portion when the first piezoelectric element is not energized, and the first piezoelectric element being configured so that the first piezoelectric element may be energized to expand between the fixed portion and the first bearing thereby substantially eliminating the first tolerance gap, and to press against the first side of the first race thereby hindering rotational movement of the first race relative to the fixed portion of the bond head.