| 摘要 |
PURPOSE:To make it possible to seal off the vacuum display device with solder in its working range to develop slow evaporation and emit little gas, by disposing solder carried by a conductive ribbon at the evacuation hole in such a manner that the solder will plug the evacuation hole, pressing the ribbon from above, applying an electric current to the ribbon to heat the solder and, at the same time, applying supersonic vibration to the solder, so that the solder is allowed to adhere to the sealing portion only interfacially at the temperature under its melting point. CONSTITUTION:A conductive ribbon 16 with solder 15 of In or Zn soft solder in a ring form soldered thereto and the tip of a supersonic horn 17 as kept in contact with each other is held coaxially with the evacuation hole 10 of the vacuum display device 11 to oppose the same, and the horn 17 is lowered in the direction as indicated by the arrow, whereby the solder 15 is pressed against the display portion 11. In this state, an electric current is applied to the conductive ribbon 16 from a power source 18, whereby the solder 15 is heated to the temperature just below its melting point. At the same time as this heating, ultrasonic vibration is applied to the horn 17 for a predetermined period of time by passing a high frequency current through a transducer. By such operation, the solder 15 is allowed to adhere to the circumferential surface of the evacuation hole 10 of the display device 11 at the temperature just below the melting point of the solder 15 and the display device 11 is sealed off with its interior kept at high vacuum. |
