GB1373397A - Wire bonding means - Google Patents

Abstract

1373397 Welding by pressure; flame cutting; interconnecting terminals J C DIEPEVEEN 14 Oct 1971 [14 April 1971] 47934/71 Headings B3R B3A and B3V A wire bonding machine for bonding a wire to a workpiece such as an integrated circuit chip or terminal associated therewith and which is capable of bonding the wire at successive locations comprises a vertically movable slide 24 adapted to be moved from a home position to a first position (at which a first bond may be made) to a subsequent intermediate position (to provide a wire loop), to a second position (for a second bond to be made) and to return to a home position, the movements and positions of the slide being controlled by cam and lever means which, in order to prevent vibrations arising from impact of the slide actuating levers with the control cams, incorporate kneeaction means in the levers to permit continual contact with the cams. The slide supports an electrically heated bonding tool 72 comprising a capillary tip through which wire may be drawn from a spool mounted on the machine, the bonding tool being pivoted by cam controlled means at the first and second positions of the slide to press the wire against the work and apply heat thereto to form a weld. The applied pressure is controlled by a spring 80. A pivotally mounted unit comprising a wire severing torch 202 and wire clamping device 204 swings in a horizontal plane towards the tool after the last bond to allow the torch to sever the wire extending from the tool 72 to the last weld and at the same time to provide a ball end to the wire still projecting from the tool, and to allow the wire clamp to grasp and remove the surplus wire end 282 extending from the last weld. The surplus piece 282 is subsequently released to vacuum pick-up means. An adjustable drag unit controlled by an adjustably positioned counterweight connected to one of the jaws of the unit tensions the wire extending from a supply spool to the bonding tool.