| 摘要 |
PURPOSE:To reduce the diameter of a pressure-welded ball as well as to increase the pressure-welding strength by a method wherein a tapered or curved chamfer part of a plurality of steps is formed at the tip of a wire inserting hole. CONSTITUTION:A chamfer part 3 is formed at the tip of the wire-inserting hole 1 of a wire bonding tool. Said chamfer part 3 is formed in two-step tapered form consisting of a tapered part 4 of large chamfer angle theta2 and a tapered part 5 of small chamfer theta3, and a little chamfer is performed at the contact point of both tapered parts and the contact point of the tapered part 5 and the wire inserting hole 1. The parts of the ball crushed at a large chamfer angle of theta2 is bonded by a strong pressure-welding strength, and also the ball is protuberated inside the tool without resistance because angle is changed slowly by the tapered part 5, thereby enabling to reduce the diameter of the pressure- welded ball. |
