Adjustable clamp system and method for wire bonding die assembly
A method and an adjustable clamp system for clamping a die assembly during wire bonding. The system includes at least one pair of opposing base walls, each of the base walls has a base clamping surface. There is at least one pair of clamping members, each one of the clamping members being movable towards a respective base clamping surface to thereby clamp a lead frame of the die assembly. A die assembly support is disposed between the pair of opposing base walls and the die assembly support and pair of opposing base walls provide a cavity. There is a position sensor coupled to a controller and there is also a drive that is controllable by the controller. The drive provides movement of the die assembly support relative to each the base clamping surface to thereby adjust a depth of the cavity. In operation, after the lead frame is clamped between the base clamping surface and clamping members, the controller allows the drive to provide the relative movement until the position sensor detects that an underside of the lead frame has abutted the die assembly support.
1. A method for clamping a die assembly during wire bonding, the die assembly having a lead frame with a die mount region with a die attached thereto, the method comprising:
placing the die assembly in an adjustable clamp system, the system having opposing base walls and a die assembly support disposed between the pair of opposing base walls, wherein the die assembly support and pair of opposing base walls form a cavity over which the die mount region is suspended by leads of the lead frame;
clamping the lead frame between clamping members and base clamping surfaces provided by the opposing base walls;
heating the opposing base walls with a heater that is disposed directly below the opposing base walls, and wherein the heater does not contact the die assembly support and the heater does not contact the lead frame and the heater does not directly heat the die assembly support and the lead frame die mount region;
providing relative movement of the die assembly support relative to the base clamping surfaces to thereby adjust a depth of the cavity;
detecting that an underside of the lead frame has abutted the die assembly support; and
stopping the relative movement in response to the detecting.
2. The method of claim 1 , further comprising heating the opposing base walls before performing the placing.
3. The method of claim 1 , wherein the base clamping surfaces form a section of a continuous track that surrounds the die assembly support.
4. The method of claim 3 , wherein the clamping members form a section of the continuous track.
5. The method claim 1 , wherein the detecting is performed by a position sensor providing at least two sensor signals, a first one of sensor signals being indicative of the underside of the lead frame abutting the die assembly support and a second one of the sensor signals being indicative of the underside of the lead frame being spaced from the die assembly support.
6. The method of claim 5 , wherein the position sensor includes a laser beam emitter aligned with a laser beam detector and wherein the laser beam emitter provides a laser beam along a plane of an upper surface of the die assembly support.
7. The method of claim 1 , the method including a further step of wire bonding electrodes of the die to respective pads of the lead frame, the wire bonding being performed after the stopping has been performed.