| 摘要 |
PURPOSE:To obtain an electron tube grid with little thermal electron and secondary electron emission and with good film adhesion by including a chemical washing process, thermal treatment process, cleaning process, and forming process of a metallic carbon film. CONSTITUTION:The surface of a grid 2 made by boring desired holes on a thin molybdenum plate 1 and molding it is cleaned by trichlene-degreasing and dilute nitric acid etching and is further heat treated for 10-15min at 700-800 deg.C in the hydrogen, then it is fitted to an electrode mounting section 4 in a vacuum bell jar 3. Next, argon gas is discharged to clean the surface of the grid 2 for 10-30min. In addition, an AC power of 150-200W is applied to a resistor heated crucible 7 so that platinum 8 in the crucible 7 is evaporated and ionized by the discharge of argon gas, thus a platinum film 9 of 0.5-1mum is formed on the surface of the grid 2. The grid 2 is kept rotating by a rotating unit during the cleaning and formation of the platinum film. |
