| 摘要 |
PURPOSE:To obtain an Al electrode material having uniformly etched many deep holes, by forming many hot parts each having a first resistant film on the surface of Al foil, forming a second resistant film on the surface of the foil except the dot parts and removing the first resistant films. CONSTITUTION:Many dot parts 2 each having a first resistant film 3 are formed on the surface of Al foil 1 at high density by dot printing with resist ink. The foil 1 is subjected to surface treatment such as chromating to form a second resistant film 4 on the surface except the dot parts 2. The first resistant films 3 are then removed by immersion in an alkali soln. to expose the Al foil 1 at the dot parts 2. By this method, the Al foil 2 is covered with the second resistant film 4 having fine holes at high density at the dot parts 2 and an Al electrode material for an electrolytic capacitor having a high rate of surface expansion can be obtd.
|
