CHEMICALLY CONVERTED SUBSTRATE FOR SOLID ELECTROLYTIC CAPACITOR AND METHOD OF MANUFACTURING THE SAME, AND SOLID ELECTROLYTIC CAPACITOR

• Main Authors: YAGI SEIICHI, UMIKAWA TAKENORI, YAMAZAKI KATSUHIKO, KONUMA HIROSHI, YAMASHITA TAKASHI
• Format: Patent
• Language: English
• Published: 30.05.2003
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE; ELECTRICITY

PROBLEM TO BE SOLVED: To provide an electrolytic capacitor with an improved capacitance and reduced variations in capacitor performance by treating a surface of a dielectric oxide coating film of a chemically converted substrate, so that a conductive substance provided on the coating film becomes a dielectric coating film which can be brought into contact with a sufficiently large contact area having favorable adhesion. SOLUTION: There are provided (1) a chemically converted substrate, in which a valve action metal surface having a dielectric coating film is at least partially coated with an oxide comprising Si, a valve metal, and O on a valve action metal substrate having a dielectric coating film made of one kind selected from aluminium, tantalum, titanium, niobium, and alloys thereof, and, more preferably, the amount of Si in a chemically converted foil having the dielectric coating film decreases continuously from the surface of an aluminium oxide dielectric coating film towards the inside; (2) a method of manufacturing the chemically converted substrate of the above (1) including a step of chemically converting the valve action metal substrate in a silicate alkaline electrolyte; and (3) a solid electrolytic capacitor having a solid electrolyte on the chemically converted substrate.