| 摘要 |
PURPOSE:To make a ball small, and to enable to perform stable control of wire bonding by a method wherein a voltage and a current are made to be formed in the plural number of stages, and made variable without interrupting a spark temporarily. CONSTITUTION:A timer 14 is set to discharge hours T1, and a timer 15 is set to discharge holding hours T2 larger than the discharge hours T1 respectively. The timers 14, 15 are driven at the same time according to a timer driving circuit 16, electric power source ciecuits 10, 11 are switched by seitching elements 12, 13, and output voltages E1, E2 are outputted. The output voltages E1, E2 are outputted at the same time at first, a discharge voltage E3 E1+E2 is applied between the tip of a wire 2 and a discharge electrode 4 to start discharge, and after the hours T1, only the output voltage E2 of the electric power source circuit 11 is applied as the discharge holding voltage. After the discharge hours T2, the output voltage E2 becomes to zero. Because a discharge current is changed according to a variable resistor 19, the current is changed also in proportion to the voltage. |
