A kind of cathode of low ESR tantalum electrolytic capacitor and preparation method thereof

Abstract

The invention relates to a low-ESR cathode of a low-ESR tantalum electrolytic capacitor and a preparation method for the cathode, and relates to the technical field of tantalum capacitor manufacturing. The preparation method comprises the steps: preparing a manganese dioxide layer on the surface of a tantalum block with a dielectric oxidation film, wherein the manganese dioxide layer is prepared through a method which comprises the steps: performing the dipping of the tantalum block in manganese nitrate solution with different specific gravities for many times, performing the thermal decomposition to obtain a first cathode, performing the dipping of the first cathode in outer mixed solution, performing the decomposition for many times under the temperature from 250 DEG C to 280 DEG C, performing the reinforcement processing, and performing the dipping and thermal decomposition in the outer mixed solution to obtain the electrode, wherein the outer mixed solution is prepared through adding a dispersing agent and a viscosity reducer to the manganese nitrate solution. The method enables the surface of the tantalum block to form compact manganese dioxide shaped like popcorn, thereby completing the manufacturing of the low-ESR electrode, and improving the high-frequency electrical performance of the tantalum electrolytic capacitor.

Description

technical field [0001] The invention relates to the technical field of tantalum capacitor manufacturing, and in particular to a cathode of a low-ESR tantalum electrolytic capacitor and a preparation method thereof. Background technique [0002] In recent years, all kinds of electronic products for military and civilian use are developing in the direction of short, small, light and thin, which requires the miniaturization of electronic components supporting it. The remarkable advantages of solid electrolytic tantalum capacitors are large capacity and easy to make small and chip components. In addition, they also have the characteristics of low ESR, low leakage current, low loss, long life, and good stability. Therefore, they are widely used in various electronic products. It has been widely used, especially in the fields of national defense such as aviation, aerospace, missiles, satellites, and radar. [0003] In the production process of solid electrolyte tantalum capacitor...

AI Technical Summary

Problems solved by technology

Excessive surface tension of the coating liquid leads to poor wettability of the solution, and the micropores of the tantalum anode cannot be filled during impregnation. The manganese dioxide produced by the thermal decomposition of manganese nitrate has a low filling rate in the micropores of the tantalum anode, and the effective cathode area is small, which is prone to The capacitance of the capacitor is low and the ESR is large; the viscosity of the coating liquid is too high, which will lead to large bubbles generated by dehydration and thermal decomposition, cracks in the manganese dioxide film layer, rough surface of manganese dioxide, hardening, loose cathode film layer, manganese dioxide The contact resistance between layers is large, which increases the ESR and seriously affects the high-frequency electrical performance of the product

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