A kind of manufacturing method of low voltage formed foil for solid aluminum electrolytic capacitor

Abstract

The invention discloses a method for manufacturing low-voltage forming foil for solid aluminum electrolytic capacitors, which mainly includes five stages of forming treatment, primary water washing, intermediate treatment, primary heat treatment, primary repair forming, secondary water washing, hydration resistance treatment, secondary heat treatment, and secondary In the process of repairing chemical formation and drying, the intermediate treatment step is to put the aluminum foil that has been washed once into 0.5-5 wt% ammonia solution, and immerse it at 30-50°C for 0.5-3 min; the temperature of the first heat treatment is 400 ~450℃, processing time 4~6 min. The intermediate treatment process can eliminate the hydration film on the surface of the foil, so that the organic polymer can enter the capacitor smoothly, thereby improving the capacity extraction rate of the device; and the hydration film has a larger gap than the crystalline oxide film, which will lead to a large leakage current of the aluminum electrolytic capacitor , After eliminating the hydration film through the intermediate treatment step, this problem can be solved well, and then the leakage current of the formed foil can be effectively reduced.

Description

technical field [0001] The invention belongs to the field of electronic material processing, and in particular relates to a method for manufacturing a low-voltage forming foil for a solid aluminum electrolytic capacitor. Background technique [0002] Formed foil is the product of special high-purity aluminum foil after electrochemical or chemical corrosion to expand the surface area, and then forms an oxide film (aluminum oxide) on the surface through electrochemical formation. As the core material in aluminum electrolytic capacitors, anodized foil plays a decisive role in various characteristics of the capacitor. The existing low-voltage anode foil formation process is generally three-stage formation, phosphoric acid treatment, four-stage formation, high-temperature heat treatment, five-stage formation, and finally ammonium dihydrogen phosphate solution in boric acid and borax solution or adipic acid and its brine solution. Medium dipping treatment, the low-voltage electro...

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Problems solved by technology

The low-voltage formed foil prepared by this scheme is used to prepare aluminum electrolytic capacitors. Although the leakage current of the capacitor can be reduced to a certain extent, since there will be a hydration film on the surface of the formed aluminum foil, the organic polymer after the solid aluminum electrolytic capacitor is made Difficult access will lead to a low capacity extraction rate of the capacitor, and the oxide film formed by chemical formation has a large gap, and the leakage current is still relatively large, which cannot meet the requirements of solid aluminum electrolytic capacitors

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