Cabot Supermetals K.k.

Isayuki Horio

Yukio Oda

Tomoo Izumi

The present invention provides an electrolytic capacitor that operates stably even when used for a long period of time under severe conditions, and forms an intermediate composition portion of metal and oxide within a chemical conversion film to a thickness of 40 nm or more so as to suppress the migration of oxygen atoms within a chemical conversion film of a valve metal. This intermediate composition portion is obtained by subjecting a base metal comprised by containing nitrogen in a valve action metal to anodic oxidation treatment.

Chemical conversion film of tantalum or niobium, method for forming the same and electrolytic capacitor using the same

A nitrogen containing metal powder wicth a large specific surface area, and containing a suitable quantity of nitrogen dispersed uniformly within the metal is produced with good productivity, and provides a solid electrolytic capacitor with a high capacitance, minimal leakage current, and excellent long term reliability. This nitrogen containing metal powder has a ratio W/S between the nitrogen content W [ppm] of the powder, and the specific surface area S [m/g], as measured by a BET method, that falls within a range from 500 to 3000. This type of powder can be produced by a process in which a metal salt containing the metal is reacted with a reducing agent and undergoes reduction within a diluent salt, thereby generating the metal, wherein a nitrogen containing gas is introduced into the space contacting the reaction melt comprising the metal salt, the reducing agent and the diluent salt, thereby generating the metal and incorporating the nitrogen within the metal.

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Kawanuma-gun, Japan

Isayuki Horio