Anode foil corrosion technology of electrolytic capacitor

Abstract

The invention relates to an anode foil etching process of an electrolytic capacitor. The process comprises pre-processing, primary electrical erosion and secondary electrical erosion, wherein, high molecular weight inhibitor is added into the etching solution of the secondary electrical erosion; the inhibitor is one or more types out of linear PAA, PAAS and polystyrene sulfonic acid; the weight percentage of the inhibitor is 0.01 percent to 10 percent. According to the weight ratio, the inhibitor solution consists of one type out of 1 percent to 10 percent of H2SO4, H3PO4, HCl and HNO or the mixed solution of H3PO4 and HCl; the inhibitor solution is not restricted by the acids and the mixed solution of two or more acids and salts; when the temperature is 30-90 DEG C, the current density is restricted at 0.1A / cm<2> to 0.5A / CM<2>; the hole expanding time is controlled within 50s to 600s; subsequently, the post-processing is carried out. The process of the invention improves the static capacity of the anode aluminium foil and reduces the weightlessness.

Description

technical field [0001] The invention relates to a metal corrosion process, in particular to a secondary electric corrosion method of the anode foil corrosion process for high-voltage aluminum electrolytic capacitors. Background technique [0002] Aluminum foil for electrolytic capacitor anode is the key raw material for the manufacture of aluminum electrolytic capacitors. One of the important indicators to measure the performance of electrolytic capacitors is the specific capacity, that is, the electrostatic capacity per unit volume. According to the capacitance formula of the plate capacitor: C=(e 0 e r S) / d, for aluminum electrolytic capacitors within the rated operating voltage range, the electrostatic capacity is mainly determined by the effective area S of the anode foil. Therefore, the key to improving the electrostatic capacity of aluminum electrolytic capacitors is to expand the effective area of ​​the anode aluminum foil. There are many ways to expand the surfac...

AI Technical Summary

Problems solved by technology

In the secondary corrosion of the existing aluminum foil, that is, the hole expansion stage, nitric acid is often used, which will cause strong self-corrosion of the aluminum foil, and the surface of the aluminum foil will dissolve before the growth of the corrosion hole, resulting in the thinning of the aluminum foil and the inability of the corrosion hole to penetrate deep, thereby increasing power consumption

Images