A method for forming a solid electrolytic capacitor that includes an anode containing a valve metal composition, a dielectric overlying the anode, and a solid electrolyte overlying the dielectric is provided. The method comprises forming the dielectric by a process that includes placing the anode into contact with an electrolyte containing an ionic liquid and a valve metal salt and applying a potential difference between the anode and a counter electrode to form a dielectric oxide layer.

A solid electrolytic capacitor containing a capacitor element is provided. The capacitor element contains a sintered porous anode body, a dielectric that overlies the anode body, a solid electrolyte that overlies the dielectric, wherein the solid electrolyte includes a conductive polymer layer, and a moisture barrier that overlies the conductive polymer layer.

A solid electrolytic capacitor containing a capacitor element is provided. The capacitor element contains a sintered porous anode body, a dielectric that overlies the anode body, a solid electrolyte that overlies the dielectric, wherein the solid electrolyte includes a conductive polymer layer, and a moisture barrier that overlies the conductive polymer layer.

A disclosed electrolytic capacitor includes a capacitor element and a cathode lead terminal. The capacitor element includes an anode body and a cathode part. The cathode lead terminal includes a connection part that is connected to the cathode part via a conductive member. The connection part includes a plate-shaped part, and first and second side walls standing from the plate-shaped part. Grooves are formed in a surface of each of the plate-shaped part and the first and second side walls. The grooves include first grooves and second grooves that are formed so as to extend continuously from the plate-shaped part across the first and second side walls. The conductive member is disposed between one surface of the cathode part and the plate-shaped part, and between two side surfaces of the cathode part and the respective corresponding first and second side surfaces.

A disclosed electrolytic capacitor includes a capacitor element and a cathode lead terminal. The capacitor element includes an anode body and a cathode part. The cathode lead terminal includes a connection part that is connected to the cathode part via a conductive member. The connection part includes a plate-shaped part, and first and second side walls standing from the plate-shaped part. Grooves are formed in a surface of each of the plate-shaped part and the first and second side walls. The grooves include first grooves and second grooves that are formed so as to extend continuously from the plate-shaped part across the first and second side walls. The conductive member is disposed between one surface of the cathode part and the plate-shaped part, and between two side surfaces of the cathode part and the respective corresponding first and second side surfaces.

When manufacturing an electrode for an electrolytic capacitor, in a first hydration step (ST1), an aluminum electrode is immersed in a first hydration processing solution having a temperature of at least 70° C. and comprising pure water or an aqueous solution to which phosphoric acid or a phosphate has been added so that the phosphorus concentration is no greater than 4 mass ppm. In a second hydration step (ST2), the aluminum electrode is immersed in a second hydration processing solution to which phosphoric acid or a phosphate has been added so that the phosphorus concentration is 4-5000 mass ppm, the second hydration processing solution having a pH of 3.0-9.0 and a temperature of at least 70° C. In a chemical conversion step (ST3), at least a boric acid chemical conversion process in which the aluminum electrode is chemically converted in a boric acid-based chemical conversion solution is included, and a chemical conversion coating having a coating withstand voltage of at least 200 V is formed on the aluminum electrode.

When manufacturing an electrode for an electrolytic capacitor, in a first hydration step (ST1), an aluminum electrode is immersed in a first hydration processing solution having a temperature of at least 70° C. and comprising pure water or an aqueous solution to which phosphoric acid or a phosphate has been added so that the phosphorus concentration is no greater than 4 mass ppm. In a second hydration step (ST2), the aluminum electrode is immersed in a second hydration processing solution to which phosphoric acid or a phosphate has been added so that the phosphorus concentration is 4-5000 mass ppm, the second hydration processing solution having a pH of 3.0-9.0 and a temperature of at least 70° C. In a chemical conversion step (ST3), at least a boric acid chemical conversion process in which the aluminum electrode is chemically converted in a boric acid-based chemical conversion solution is included, and a chemical conversion coating having a coating withstand voltage of at least 200 V is formed on the aluminum electrode.

A solid electrolytic capacitor comprises a capacitor element, an outer anode terminal, an outer cathode terminal and an outer mold. The capacitor element has an anode lead wire, an anode body and a cathode layer. The capacitor element has an upper surface and a lower surface in an up-down direction. The outer cathode terminal and the outer anode terminal are positioned away from each other in a predetermined direction perpendicular to the up-down direction. The outer cathode terminal has an upper portion, a lower portion and a connecting portion. One of the upper portion and the lower portion is longer than a remaining one of the upper portion and the lower portion in the predetermined direction. The outer mold covers the capacitor element so that each of the outer anode terminal and the outer cathode terminal is partially exposed to an outside of the solid electrolytic capacitor.

A conductive paste for an electrolytic capacitor used for connecting a cathode part and a cathode lead terminal of the electrolytic capacitor. The conductive paste includes a thermosetting resin, and conductive particles, and the conductive particles include flaky metal particles and acicular conductive particles. The content of the conductive particles in the conductive paste is, for example, 50 mass % or more and 70 mass % or less, and the mass ratio of the flaky metal particles to the total of the flaky metal particles and the acicular conductive particles is, for example, 60% or more and 80% or less.

An electrolytic capacitor includes a capacitor element, a cathode lead terminal, and an exterior body. The cathode lead terminal includes a first cathode lead part facing a first main surface of the capacitor element, a second cathode lead part bent from the first cathode lead part, a third cathode lead part bent from the second cathode lead part, and a fourth cathode lead part bent from the first cathode lead part. The second cathode lead part extends in a direction along a surface intersecting with the first main surface. The third cathode lead part extends to be exposed from the exterior body. The fourth cathode lead part extends along a second main surface of the capacitor element. In the normal direction of the first main surface, a height h of the fourth cathode lead part is less than or equal to a height H from the first cathode lead part to a portion of the third cathode lead part that is not exposed from the exterior body.