| 摘要 |
PURPOSE:To prevent the coarsening of crystal grains in the root section of the ball of a wire, and to obtain a bonding loop of stable height by providing a cooling device which can cool the root section of the ball of the wire. CONSTITUTION:A ball 9 is formed at the tip of wire 8 penetrated into a bonding tool 7. A cooling element 10 is fitted to the lower section of the tool 7, and cools the lower section of the tool. Consequently, the root section of the ball 9 is cooled through the bonding tool 7 cooled by the cooling element 10 in the wire 8, and crystal grains 3A in a section B are made finer and stronger than those through conventional systems. Accordingly, the strength of the wire is improved, and the stable loop can be obtained. |
