Electrolytic capacitor low impedance anode aluminum foil erosion method and its chemical processing fluid

Abstract

The invention relates to a method for corroding the low-impedance anode aluminum foil for electrolytic capacitor and the chemical pretreatment solutions. The method comprises the following steps: the first step of primary electrolytic corrosion, the second step of chemical treatment and the third step of secondary electrolytic corrosion; the chemical pretreatment solutions consist of 4.0N to 5.0N of hydrochlorides, 0.15N to 5.0N of sulfates, 0.05N to 0.15N of phosphoric acids, 0.01N to 0.05N of nitric acids and 1.0N to 2.0N of aluminium chlorides. The invention forms the uniformly distributed pits with larger clearances and passive films enduring the corrosion on the surface of the clean aluminium foil and then implements the expanding treatment, so the impendance of the obtained etching foil is outstandingly lowered and in particular the invention has outstanding effects on the electrode foil with a voltage ranging from 50 to 100V. The use of the method controls the size, distribution and clearance of the pits to a certain extent, improves the corrosion morphology and increases the clearance of the pits and distribution uniformity so as to lower the impedance of the anode foil. The invention is suitable for the corrosion of the low-voltage aluminium foil with a voltage ranging from 25V to 100V, can lower the impedance of the anode foil by a great amount and can be used for preparing the low-impedance electrolytic capacitor anode aluminium foil.

Description

technical field [0001] The invention relates to the technical field of corroding anode foils for aluminum electrolytic capacitors, and relates to a method for corroding low-impedance anode aluminum foils of electrolytic capacitors and a chemical treatment solution thereof. Background technique [0002] Anode foil is the main raw material for the production of aluminum electrolytic capacitors, and its quality directly affects the performance of capacitors. Low-impedance capacitors have become a major direction in the development of capacitors. The quality level of domestic anode foil manufacturing companies is still low. Take the 132V specification product as an example, the impedance can only reach 1.2mΩ. Compared with similar foreign products, there is still a considerable gap. [0003] The corrosion morphology of anode foil is closely related to its impedance. There are three ways to reduce the impedance of the anode foil: (1) increase the aluminum content in the corrod...

AI Technical Summary

Problems solved by technology

However, its electrode foil products have problems such as too many local corrosion holes, uneven distribution, and small distance between corrosion holes.