| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an impregnated negative electrode structure, having sufficient ion impact resistant characteristics and excellent electron emitting characteristics even in high-voltage and high-duty condition. SOLUTION: One surface of a porous tungsten disk 21 is coated with a brazing material, and blazed in the high temperature hydrogen furnace and to coat both surfaces thereof with the light exposing resist 31 with about 8μm of thickness. Exposure and development are performed to form annular recessed parts 32, 33, corresponding to a porous negative electrode base 4 in both surfaces of the porous tungsten disk 21. Etching is performed to the porous tungsten disk 21 for eliminating the resist 31, and the electron-emitting material is melted for impregnation in the hydrogen atmosphere, and the excessive electron-emitting material is washed away with water. Laser beam is used to cut parts corresponding to the recessed parts 32, 33, and the recessed parts 32, 33 are formed as notch parts to form a porous negative electrode base 4.</p> |
