Apparatus for bonding leads to semiconductor chips

摘要

In the bonding apparatus disclosed herein, possible misalignment of a semiconductor chip at the work station is sensed by first optically scanning the workpiece using a video scanning head mounted on a common X-Y carriage with the bonding head. A zone signal is generated which defines, within the scanned area, a limited zone of consideration. The video signal is evaluated as a function of the zone signal to measure the extent of coincidence between the zone and a target area on the workpiece. The placement and dimensions of the zone are progressively adjusted responsive to the evaluation and in accordance with a search algorithm to locate at least two target areas on the workpiece and the bonding head is then traversed to adjusted target coordinates derived from the optically located target areas.