BUMP-FORMING METHOD

PROBLEM TO BE SOLVED: To prevent the deformation of wire after it has been cut, and to shorten bump-forming time by pressing a ball formed at the tip of wire inserted into a capillary on the electrode of a semiconductor device, raising the capillary and cutting the root of the ball with a cutter from both sides. SOLUTION: A ball 6 is formed at the tip of a wire 5 inserted into the capillary 4 by a discharge, the capillary 4 is lowered, and the ball 6 is pressed on an electrode 2 of a semiconductor device 1. Then, the capillary 4 is raised. It, a pair of cutters 20 provided to face each other are closed, and the holding root of the ball 6 is cut. Then, a clamper 3 is closed, and wire 5 is clamped. A clamper 3 and the capillary 4 are raised. Thus, a bump 8 is formed on the electrode 2. A pair of cutters 20 is lowered in a closed state, and the bump 8 is pressurized at a prescribed pressure. Thus, the upper face of the bump 8 is formed to be planar by the lower faces of the cutters 20.