Manufacturing method of low-voltage formed foil for solid aluminum electrolytic capacitor

Abstract

The invention discloses a manufacturing method of a low-voltage formed foil for a solid aluminum electrolytic capacitor. The method mainly comprises the processes of five-stage formation treatment, primary water washing, intermediate treatment, primary heat treatment, primary repair formation, secondary water washing, hydration-resistant treatment, secondary heat treatment, secondary repair formation and drying treatment. The intermediate treatment step is achieved by putting the aluminum foil subjected to primary water washing into 0.5-5wt% of an ammonia water solution and carrying out dipping treatment for 0.5-3min at the temperature of 30-50 DEG C. The temperature of the primary heat treatment is 400-450 DEG C, and the treatment time is 4-6 minutes. A hydrated film on the surface of the formed foil can be eliminated in the intermediate treatment process, so that an organic polymer can smoothly enter the capacitor, and the capacity extraction rate of the device is further improved. The gap of the hydrated film is larger than that of a crystalline oxide film, so that the leakage current of the aluminum electrolytic capacitor is large, the problem can be well solved after the hydrated film is eliminated through the intermediate treatment step, and the leakage current of the formed foil is 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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