| 摘要 |
PURPOSE:To suppress increasing of dark current of a camera tube and to realize conventional quality level of vacuum rate of a bulb without heat treatment by subjecting the surface of a transparent conductive film which is formed on a base plate to ion-etching in N2 gas ambient. CONSTITUTION:SnO2 NESA is formed on a base plate by a spraying method, etc. And after giving slight abrasive operation and so on, by a machine to this surface of SnO2 NESA, dust on the surface is removed through a cleaning process. And after making inside of an etching device, for example, lower than 2.0X10<-6>Torr, this SnO2 NESA is subjected to ion-etching, maintaining N2 gas within the extent of 5X10<-2>-5X10<-4>Torr. The thickness of this etching is, for example, 400-1,500Angstrom . And when the thickness of this etching increases, smoothness can be increased. After the ion-etching, adhered dust is removed and cleaned, and upon these, a photoconductive film is formed. Thus, a bulb need not be subjected to heat treatment for its vacuum rate and the quality level can be maintained. |
