Solid electrolytic capacitor and method for manufacturing same
View Patent ↗A solid electrolytic capacitor employing a conductive polymer has a solid electrolyte layer with a laminated structure where a second conductive polymer layer complexed with an ionic polymer is stacked on a first conductive polymer layer composed of polyaniline or a derivative thereof. By achieving a solid electrolyte layer having an excellent self-healing property, a solid electrolytic capacitor having an excellent withstand voltage characteristic can be provided.
1. A solid electrolytic capacitor comprising a capacitor element having a sheath,
the capacitor element including:
a valve metal having a porous layer;
a dielectric film formed on a surface of the porous layer;
a solid electrolyte layer formed on the dielectric film;
a collector layer formed on the solid electrolyte layer; and
external electrodes coupled to the valve metal and the collector layer, respectively,
the solid electrolyte layer including:
a first conductive polymer layer that is formed on the dielectric film and made of a conductive polymer containing a derivative of polyaniline; and
a second conductive polymer layer that is formed on the first conductive polymer layer and made of a conductive polymer complexed with an ionic polymer, the ionic polymer made from maleic acid,
wherein the derivative of polyaniline is a conductive polymer represented by a following formula,
2. The solid electrolytic capacitor of claim 1 , wherein
the ionic polymer is polymaleic acid.
3. The solid electrolytic capacitor of claim 1 , wherein
the ionic polymer is a copolymer of maleic acid and at least one monomer selected from olefine, vinyl ether, and vinyl alcohol.
4. The solid electrolytic capacitor of claim 1 , wherein
the second conductive polymer layer is a conductive polymer layer formed by one of chemical polymerization, electrolytic polymerization, and combined use of the chemical polymerization and the electrolytic polymerization.
5. A manufacturing method of a solid electrolytic capacitor comprising:
forming a dielectric film on a surface of a valve metal having a porous layer;
forming a first conductive polymer layer on a surface of the dielectric film, the first conductive polymer layer being made of a conductive polymer containing a derivative of polyaniline;
forming a second conductive polymer layer on the first conductive polymer layer, the second conductive polymer layer being made of a conductive polymer complexed with an ionic polymer, the ionic polymer made from maleic acid;
forming a collector layer on a surface of the second conductive polymer layer; and
coupling external electrodes to the valve metal and the collector layer, respectively, wherein the derivative of polyaniline is a conductive polymer represented by a following formula,
6. The manufacturing method of the solid electrolytic capacitor of claim 5 , wherein
the step of forming the second conductive polymer layer is a step of forming a conductive polymer layer by chemical polymerization.
7. The manufacturing method of the solid electrolytic capacitor of claim 5 , wherein
the step of forming the second conductive polymer layer is a step of forming a conductive polymer layer by electrolytic polymerization.
8. The manufacturing method of the solid electrolytic capacitor of claim 5 , wherein
the step of forming the second conductive polymer layer is a step of forming a conductive polymer layer by combined use of chemical polymerization and electrolytic polymerization.