Production of a tailless ball bump

摘要

A method of producing a ball bump on a workpiece employs a capillary having a passageway therethrough. A wire extends through the passageway and has a ball formed on its end below the capillary. The capillary is positioned above a bond site and is lowered until the ball contacts the bond site. The capillary simultaneously applies ultrasonic energy and a downward force against the ball to deform the ball to a ball bump and bond it to the bond site. The capillary is thereafter displaced in a first direction to break the wire away from the ball bump. The capillary is then displaced in a second direction across the ball bump to engage any residual wire protruding from the ball bump surface and substantially smooth the residual wire against the ball bump surface.