| 摘要 |
PURPOSE:To keep the stability of discharge, and to form the diameter of a ball shaped at the tip section of a wire in specified size by irradiating a torch electrode with ultraviolet rays when high tension is applied between the tip section of the wire and the torch electrode. CONSTITUTION:An ultraviolet irradiation lamp 4 is mounted so as to be able to irradiate the surface of a torch electrode 2 oppositely faced to the tip section 1a of an Au wire 1. The surface of the torch electrode 2 is irradiated with ultraviolet rays 4a by the UV lamp 4 during application after a time immediately before high tension is applied between gaps by a power supply 3. A work function is kept constant by applying ultraviolet rays, and stable discharge can be conducted, thus preventing the dispersion of the diameter of a ball. Discharge maintaining voltage is fluctuated when gap length is changed when discharge currents are kept constant in the relationship of gap length and the diameter of the ball, and the diameter of the ball is varied. |
