Solid electrolytic capacitor

Abstract

In a solid electrolytic capacitor provided with an anode, a cathode, and a dielectric layer formed by anodization of the anode, the anode includes a first metal layer and a second metal layer. The first metal layer is made of any of metal selected from niobium, aluminum and tantalum, or an alloy containing any of metal selected from niobium, aluminum and tantalum as a main component. The second metal layer contains any of metal selected from titanium, zirconium and hafnium. Here, a part of a surface of the first metal layer is covered with the second metal layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a solid electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a top plan view for explaining a structure of an anode of the solid electrolytic capacitor according to the embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining a system for measuring a leakage current in a capacitor element.

FIG. 4 is diagram for explaining an observation method of an anode 1 by use of a scanning electron microscope (SEM).

Claims

1. A solid electrolytic capacitor provided with an anode, a cathode, and a dielectric layer formed by anodization of the anode, wherein, the anode includes a first metal layer and a second metal layer,the first metal layer is made of any of metal selected from the group consisting of niobium, aluminum and tantalum, or an alloy containing any of the metal selected from the group consisting of niobium, aluminum and tantalum as a main component,the second metal layer contains any of metal selected from the group consisting of titanium, zirconium and hafnium, anda part of a surface of the first metal layer is covered with the second metal layer.

2. The solid electrolytic capacitor according to claim 1, wherein an area of a region of the first metal layer covered with the second metal layers is 0.5% or more and 10% or less, of a surface area of the first metal layer.

3. The solid electrolytic capacitor according to claim 1, wherein, the second metal layer is dispersed in a plurality of regions, andthe plurality of regions cover parts of the surface of the first metal layer.