| 摘要 |
PURPOSE:To obtain an electrolytic capacitor of high quality by sintering a powder molding of a valve action metal in a high vacuum by an oil diffusion pump at temp. from room temp. up to specific temp. then sintering the same in a high vacuum using a cryogenic pump in the temp. elevating process up to the prescribed sintering temp. and a cooling process. CONSTITUTION:A powder molding of a valve action metal such as Ta, Nb or the like is sintered in a vacuum furnace under the following conditions: Said molding is sintered in a range from room temp. up to 1,000 deg.C while a desired high vacuum state is maintained by an oil diffusion pump, whereby the H2 contained in the molding is virtually removed. In the stage of sintering said sintered molding in succession, the molding is sintered in a desired high vacuum state by using a cryogenic pump using gaseous He as a refrigerant in the temp. elevating process from 1,000 deg.C up to prescribed sintering temp., for example 1,700 deg.C, the time for holding at said sintering temp. and a cooling process. As a result, the sinered body having high voltage, that is, puncture voltage, at which oxidized films grow no longer in the anodization of the sintered body is obtained. |
