| 摘要 |
An object of the present invention is to provide a tantalum sintered body which has high performance such as a reduced leakage current and an improved resistance to lowering of the capacitance, depending on a size of a desired capacitor. In order to achieve the object, the present invention provide a production method of a tantalum sintered body for an electrolytic capacitor comprising the steps of: a molding step (I) in which a tantalum powder having a bulk density of 0.50 to 1.85 g/cm3, which is obtained by heat treating a deoxidized tantalum powder in an inert gas atmosphere at a high temperature and crushing, is molded so that the density is 4.5 to 7.0 g/cm3 and a volume is less than 5 mm3; and a sintering step in which the molded product is heated in a vacuum so that a volume shrinkage percentage is 2 to 15%. In addition, instead of the molding step (I), a molding step (II) in which a tantalum powder having a bulk density of 1.75 to 2.5 g/cm3, which is obtained by heat treating a deoxidized tantalum powder in an inert gas atmosphere at a high temperature and crushing, is molded so that the density is 4.5 to 7.0 g/cm3 and a volume is 5 mm3 or greater, can be comprised. |
