Solid tantalum electrolytic capacitor and manufacturing method thereof

Abstract

The invention discloses a solid tantalum electrolytic capacitor comprising a tantalum anode body, an Ra2O5 dielectric envelope, a conducting layer, a graphite layer and a silver coating, wherein the Ra2O5 dielectric envelope is positioned on the surface of the tantalum anode body, the conducting layer is positioned on the Ra2O5 dielectric envelope, and the graphite layer and the silver coating are coated on the conducting layer. The solid tantalum electrolytic capacitor is characterized in that the conducting layer is a mixed system of composite carbon nano tubes and high-polymer conducting materials, the length directions of the composite carbon nano tubes are perpendicular to the surface of the tantalum anode body, the composite carbon nano tubes are carbon nano tubes with the surfaces uniformly attached with nano particles in a shell-core structure, and the nano particles in the shell-core structure are nano particles using magnetic nano particles as cores, wherein the surfaces of the nano particles are coated with conducting shell layers. Because the directionally arranged composite carbon nano tubes are adopted in the conducting layer, the conductivity of the conducting layer is increased, and the equivalent series resistance of the capacitor is reduced, thereby the high-frequency characteristic of the capacitor is improved.

Description

technical field [0001] The invention relates to the technical field of capacitors, in particular to a solid tantalum electrolytic capacitor and a preparation method thereof. Background technique [0002] In recent years, with the downsizing and weight reduction of electronic devices, small and high-capacity high-frequency capacitors are required, so solid electrolytic capacitors in which a solid electrolytic layer is formed of a solid conductive compound have been proposed. [0003] A solid electrolytic capacitor includes, for example, an Al (aluminum) or Ta (tantalum) metal anode body, a dielectric oxide film formed by oxidation treatment on the surface of the anode body, and a solid conductive compound such as MnO 2 (manganese dioxide), conductive high molecular polymer to the oxide film, and the cathode layer in close contact with the oxide film. Compared with paper dielectric capacitors and film capacitors, electrolytic capacitors are smaller in size and higher in capac...

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Problems solved by technology

[0007] Although manganese dioxide is regarded as a potential capacitor electrode material, manganese dioxide has poor conductivity and has been replaced by some organic compounds with higher conductivity than manganese dioxide. The electrolyte resistance R has a great influence on the high frequency characteristics of the capacitor, therefore, it is necessary to use a higher conductivity electrolyte to increase the performance of the capacitor

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