Automatic wire feed system

摘要

An improved automatic wire feed system for supplying a fine wire to a capillary bonding tool or to a wedge bonding tool is provided. The wire feed system includes a novel wire feed slack loop device which is mounted on the wire bonder between the bonding tool and the source of fine wire. The novel wire feed slack loop device comprises a pair of sector plates which are closely spaced apart from each other to provide an air space therebetween for receiving the fine wire. Compressed air is supplied to the air space between the sector plates and is directed radially outward by a diffuser shim plate which forces the wire to form into a uniform circular shape in the air space. Sensor means are provided at the outer perimeter of the sector plates which sense the position of the fine wire and supplies a signal to control means which turns off the rotation of the drive motor. Turning off the gas provides a slack wire loop with sufficient fine wire to make an interconnection on a semiconductor device without creating tension or compression of the wire at the bonding tool.