Capacitor and method for producing the same, and circuit board with a built-in capacitor and method for producing the same

摘要

A miniature solid electrolytic capacitor is provided, which is suitable for being disposed within an electrically insulating layer, and is connected to other component using an electrically conductive adhesive with a connection resistance at an anode low and with connection reliability improved. Specifically, the electrolytic capacitor includes a valve metal element for an anode 10 having a capacitor forming part 10A and an electrode lead part 10B, a dielectric oxide film 11 formed on the valve element, a solid electrolyte layer 12 formed on the dielectric oxide film 11 and a charge collecting element for a cathode 13 formed on the solid electrolyte layer 12, wherein at least one through hole 15 is formed in the electrode lead part 10B so as to expose a core 10C of the valve metal element, and an exposed portion 10D of the core is used for connecting portion.