| 摘要 |
PURPOSE:To prevent the creeping of solder by mounting a conduction detecting circuit between a lower metallic plate and an upper metallic plate, detecting a contact with solder of the upper metallic plate and applying pressure to solder only by its own weight of the upper metallic plate. CONSTITUTION:An upper metallic plate 3 is lowered gradually, the upper metallic plate 3 and solder 4 are brought into contact, the voltage of a battery 8 is applied to a resistor 9, a light-emitting diode 10 and a P-N junction in a diode chip 1, and the light-emitting diode 10 emits light. The descent of a heater 5 and the upper metallic plate 3 is stopped at that time, and the support of the upper metallic plate 3 is released. A slight clearance is left between the upper metallic plate 3 and the diode chip 1 while being heated by the heater 5, the heater 5 is pushed down, and solder 4 is melted. Since only the weight section of the upper metallic plate 3 is applied to solder 4 as pressure and there is the clearance between the diode chip 1 and the upper metallic plate 3, the overflow of solder 4 and a short circuit between the upper and lower metallic plates 2, 3 can be prevented. |
