| 摘要 |
PURPOSE:To prevent a ball from oxidizing and to contrive to improve the bonding property of wire by a method wherein, when the ball is formed on the point of the wire, gas, wherein H2 gas has been mixed with inactive gas, such as N2 gas, at a ratio of 0.01-1.0vol%, is used as shielding gas for oxidation prevention, which is sprayed on the region embracing the point of the wire. CONSTITUTION:In case a wire 13 is bonded on the pad part of a pellet 17, firstly, the main body 14 of a torch is made to advance in such a way that a torch electrode 16 opposes to the lower end of a capillary 12. At this time, the point of the wire 13 inserted in the capillary 12 is made to approach the lower end of the capillary 12. On the other hand, shielding gas, which is fed from a shielding gas feed source, is blowing off from a feeding port body 14. Therefore, the region embracing the torch electrode 16 and the point of the wire 13 has been shielded from the atmosphere by the shielding gas. When voltage is impressed on the torch electrode 16 under this condition, sparks generate and a ball 18 is formed on the point of the wire 13. As a result, the surface oxidation of the ball 18 can be prevented, because the ball 18 has been covered with shielding gas, wherein H2 gas has been mixed with inactive gas at a ratio of 0.01-1.0vol%. |
