BUMP-FORMING METHOD

PROBLEM TO BE SOLVED: To provide a bump-forming method capable of stably cutting wires. SOLUTION: A wire 2, passing through a hole 1a of a capillary 1, is heated at the top end to form a ball 2a which is then pressed to a terminal electrode 4, while a capillary 1 is moved down together with the wire 2 to approach a press-to-cut part 1b of the capillary top end to the terminal electrode 4. This causes the press-to-cut part 1b to bury into the center of the ball 2a and collapse the ball 2a at the bevel of the capillary top end, resulting in the contact of this part 1b to the electrode 4 where the ball 2a, deformed like a doughnut, is cut from the wire 2.