Anode aluminium foil etching process for electrolytic capacitor

Abstract

The etching process of anode aluminum foil for electrolytic capacitor includes one pre-treatment step. The pretreating solution is solution of alkali, acid or their mixture with Zn and/or Pb compound in 0.0001-1.0 wt% added. Aluminum foil is soaked in the pretreating solution for 10-300 sec, and owing to the separation of Zn and/or Pb, the aluminum foil surface becomes more easy in producing homogeneous spot etching in the fore etching process, and this results in raised area expanding rate, specific capacitance and tensile strength of the aluminum foil.

Description

technical field [0001] The invention relates to a metal corrosion process, in particular to a pretreatment method for an electrolytic capacitor anode aluminum foil corrosion process. Background technique [0002] Aluminum foil for electrolytic capacitor anode, in order to expand its effective surface area and increase the electrostatic capacity (specific capacity) per unit area, is generally subjected to chemical or electrochemical corrosion treatment to form high-density uniformly distributed corrosion pits with a certain depth on the surface. Thereby increasing the surface area of ​​the aluminum foil. The corrosion process generally includes the following steps: pre-treatment, pre-corrosion, post-corrosion, and post-treatment. Pre-treatment is a variety of physical and chemical treatments before electro-etching the light foil. Its main function is to remove oil, impurities and natural oxide film on the surface of the aluminum foil, adjust the structure of the aluminum foi...

AI Technical Summary

Problems solved by technology

The existing pretreatment process is to immerse the aluminum foil directly in an acid or alkali solution for a few minutes at a certain temperature. This treatment removes the oil and oxide film on the surface of the alum...