Corrosion process method of anode foil for solid aluminum electrolytic capacitor

Abstract

The invention provides a corrosion process method of an anode foil for a solid aluminum electrolytic capacitor. The process is that a soft annealed aluminum foil is subjected to AC variable-frequency corrosion through a mixed solution after pre-treatment, wherein the mixed solution contains 2 to 20wt% of hydrochloric acid, 0.02 to 0.2wt% of sulfuric acid, and 0.02 to 2wt% of aluminum trichloride; then the aluminum foil is subjected to intermediate treatment through an aqueous solution containing 0.5 to 10wt% of phosphoric acid or other acidic salts; the AC variable-frequency corrosion is repeatedly carried out at a plurality of times according to different waveforms and the process that frequency gradually varies from high to low (40 to 5Hz), so as to achieve multi-stage hole expansion corrosion for the aluminum foil; finally the aluminum foil is chemically cleaned. The corroded foil obtained by the aforementioned process is high in specific volume and high in mechanical strength and is applicable to the production of solid aluminum electrolytic capacitor.

Description

technical field [0001] The invention relates to a processing technology of an anode foil, in particular to a corrosion process method of an anode foil for a solid aluminum electrolytic capacitor. Background technique [0002] Anode foils for solid aluminum electrolytic capacitors require a higher electrostatic capacity per unit area of ​​the anode foil. In order to expand its effective surface area and increase the electrostatic capacity per unit area, the aluminum foil is generally treated with electrochemical corrosion. There are many reports on the research on increasing the area expansion rate. In the past, 50Hz AC corrosion was used in the past process, or the method of changing the power frequency to expand the size of the corrosion pit, but the size and depth of the corrosion pit in these existing technologies are not easy to control. Anode foils for solid aluminum electrolytic capacitors require an area-expanding effect. Contents of the invention [0003] Purpose ...

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Problems solved by technology

There are many reports on the research on increasing the area expansion rate. In the past, 50Hz AC corrosion was used in the past process, or the method of changing the power frequency to expand the size of the corrosion pit, but the size and depth of the corrosion pit in these existing technologies are not easy to control. Anode foil for solid aluminum electrolytic capacitors needs surface expansion effect

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