Technique method of preparing cathode of panseal non-solid electrolytes whole tantalum capacitor

Abstract

The invention discloses a method for preparing a cathode of a full-sealing non-solid-electrolyte full tantalum capacitor; the method comprises the processing of a current collector, the molding and sintering of the cathode and the electrochemical oxidation of a tantalum cathode; the method at least comprises the following technical steps: (1) tantalum chips or tantalum meshes or tantalum felts are taken as the current collector which then is processed; the tantalum chips or tantalum meshes are put in a solution containing inorganic acids including sulfuric acid, nitric acid or hydrofluoric acid and the like for surface treatment, heated and boiled, washed with clean water and finally dried to obtain the processed current collector; (2) the processed current collector is put in a molding-machine die, loaded with high specific-volume tantalum powder, compressed and molded by the molding machine, put into a vacuum sintering furnace for vacuum sintering, sintered at the temperature of 1,200 DEG C to 1,600 DEG C for 20 minutes to 60 minutes, and the cathode is taken out of after the furnace temperature is reduced; and (3) the molded and sintered tantalum cathode is put in the phosphoric acid solution for the electrochemical oxidation and is applied with certain direct current and voltage so that a layer of tantalum pentoxide film is produced on the surface of the tantalum cathode.

Description

Technical field: [0001] The invention relates to a cathode preparation method for electronic components, in particular to a cathode preparation method for a fully sealed non-solid electrolyte all-tantalum electrolytic capacitor. Background technique: [0002] In some circuits with high reliability requirements, fully sealed non-solid electrolytic tantalum capacitors have been widely used, while ordinary non-solid electrolytic tantalum capacitors using silver shells as packaging materials cannot withstand reverse voltage; while ruthenium oxide or Another type of fully sealed liquid tantalum hybrid capacitor with carbon-ruthenium oxide mixed as the cathode, although it has the characteristics of high specific volume per unit volume, but because the functional material used in the cathode has a specific use potential range, it cannot withstand reverse voltage . Although the traditional CAK38 and CAK39 fully sealed non-solid electrolyte all-tantalum capacitors with reliability ...

AI Technical Summary

Problems solved by technology

[0002] In some circuits with high reliability requirements, fully sealed non-solid electrolytic tantalum capacitors have been widely used, while ordinary non-solid electrolytic tantalum capacitors using silver shells as packaging materials cannot withstand reverse voltage; while ruthenium oxide or Another type of fully sealed liquid tantalum hybrid capacitor with carbon-ruthenium oxide mixed as the cathode, although it has the characteristics of high specific volume per unit volume, but because the functional material used in the cathode has a specific use potential range, it cannot withstand reverse voltage

Although the traditional CAK38 and CAK39 fully sealed non-solid electrolyte all-tantalum capacitors with reliability indicators can withstand a certain reverse voltage, they use a tantalum sleeve that is sintered after pressing and molding tantalum powder as the cathode. There is a large gap between the anodes, which makes the energy density per unit volume and volume specific capacity of the capacitor relatively low, which cannot meet the needs of fully sealed non-solid electrolyte all-tantalum capacitors with high energy density in electronic circuits

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