Unlock instant, AI-driven research and patent intelligence for your innovation.

Corrosion method of corrosive foil for aluminum electrolytic capacitor

A technology for aluminum electrolytic capacitors and corroded foils, which is applied in the field of electrode materials for capacitors, can solve the problems of difficulty in tunnel hole expansion, increased difficulty in programmed control, and decreased corrosion foil performance, so as to prevent silver ions from depositing on the surface of aluminum foil, Eliminate the influence of silver ions and stabilize the performance

Active Publication Date: 2020-11-13
DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD
View PDF6 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Compared with aluminum, silver ions have a very positive electrode potential, and deposit on the surface of aluminum foil to form silver element, which makes it difficult to expand inside the tunnel hole, and the over-corrosion at the hole leads to a serious decline in the performance of the corroded foil
At present, the treatment method for the hole-enlarging corrosion solution doped with silver ions is usually to replace the corrosion solution. Although this method is simple, it also leads to increased operating costs and increased difficulty in programmed control.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Corrosion method of corrosive foil for aluminum electrolytic capacitor
  • Corrosion method of corrosive foil for aluminum electrolytic capacitor
  • Corrosion method of corrosive foil for aluminum electrolytic capacitor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach

[0037] According to some embodiments provided by the present invention, the corrosion method of the corrosion foil for aluminum electrolytic capacitors includes:

[0038] 1) Pretreatment: place the aluminum foil in 45-75°C and 0.5-5% phosphoric acid aqueous solution for 1-4min;

[0039] 2) Pore corrosion: place the pretreated aluminum foil in a mixed aqueous solution containing 1.5-4.5% hydrochloric acid by mass fraction, 28-38% sulfuric acid by mass fraction and 0.5-1.5% aluminum ion by mass fraction. Pore ​​corrosion, the corrosion temperature is 65-85°C, the constant current is applied, and the current density is 0.5-0.65A / cm 2 , the corrosion time is 50-70s;

[0040] 3) Hole expansion corrosion: place the aluminum foil through the hole corrosion in 1.8-6.5% nitric acid by mass fraction, 0.2-2.0% phosphoric acid by mass fraction, 0.27-0.8% aluminum ion by mass fraction and mass concentration of Carry out hole expansion corrosion in a mixed aqueous solution of 0.05-1.5g / L po...

Embodiment 1

[0049] In this embodiment, the corrosion method of the corroded foil for aluminum electrolytic capacitors provided includes pretreatment, porosity corrosion, hole expansion and posttreatment, as follows:

[0050] (1) Pretreatment: Treat an aluminum foil with a thickness of 125 μm in an aqueous phosphoric acid solution with a mass fraction of 2.0% at 65° C. for 3 minutes;

[0051] (2) Pore corrosion: place the pretreated aluminum foil in a mixed aqueous solution containing hydrochloric acid, sulfuric acid and aluminum ions to form pores. The mass fraction of hydrochloric acid is 2.9%, the mass fraction of sulfuric acid is 35%, and the mass fraction of aluminum ions is 1.0%. ; The temperature of the corrosion solution is 72°C, the decay current is used, and the initial current density is 1.5A / cm 2 , the current density drops to 0.7A / cm after 4s 2 , after 15s the current density is 0.15A / cm 2 , the total power-on time is 25s, repeat the hole 4 times according to the attenuation...

Embodiment 2～ Embodiment 9

[0055] In this embodiment, the corrosion method of the corroded foil for aluminum electrolytic capacitors provided includes pretreatment, porosity corrosion, hole expansion and posttreatment, as follows:

[0056] (1) Pretreatment: Treat an aluminum foil with a thickness of 125 μm in an aqueous phosphoric acid solution with a mass fraction of 2.0% at 65° C. for 3 minutes;

[0057] (2) Pore corrosion: place the pretreated aluminum foil in a mixed aqueous solution containing hydrochloric acid, sulfuric acid and aluminum ions to form pores. The mass fraction of hydrochloric acid is 2.9%, the mass fraction of sulfuric acid is 35%, and the mass fraction of aluminum ions is 1.0%. ; The temperature of the corrosion solution is 72°C, the decay current is used, and the initial current density is 1.5A / cm 2 , the current density drops to 0.7A / cm after 4s 2 , after 15s the current density is 0.15A / cm 2 , the total power-on time is 25s, repeat the hole 4 times according to the attenuation...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Current densityaaaaaaaaaa
Current densityaaaaaaaaaa
Login to View More

Abstract

The invention provides a reaming corrosive solution additive for a corrosive foil and a method for preparing the corrosive foil for an aluminum electrolytic capacitor by using the reaming corrosive solution containing the additive. The additive is polyvinylpyrrolidone. By introducing polyvinylpyrrolidone in the reaming corrosive solution in the invention, one the one hand, the polyvinylpyrrolidonehas very good water solubility and low toxicity to be able to stably exist in the reaming electrolyte to play a corrosion inhibition and to ensure stable performance of the corrosive foil; and on theother hand, the polyvinylpyrrolidone has specific adsorption to silver ions, which can inhibit the deposition of silver ions on the surface of aluminum foil when silver ions are introduced into the reaming corrosive solution in the actual production process and quickly eliminate the influence of silver ions in the reaming corrosive solution.

Description

technical field [0001] The invention belongs to the technical field of electrode materials for capacitors, and in particular relates to an etching method for an etching foil used in a hole-expanding etching solution. Background technique [0002] Aluminum electrolytic capacitor is an important electronic component, which is widely used in filtering, bypassing, coupling and other technical fields. Corrosion foil is the core raw material for aluminum electrolytic capacitors, and its production process mainly includes pre-treatment-hole-expansion-hole-expansion-post-treatment-drying process. The pretreatment is mainly to remove the oil film and oxide film on the surface of the aluminum foil, and improve the porosity on the surface of the aluminum foil. In the process of opening holes, it is usually necessary to apply direct current corrosion in chlorine-containing acidic etching solution to produce a large number of initial tunnel holes. In order to ensure that the pore size ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C25F3/04
CPCC25F3/04
Inventor 肖远龙向云刚祁菁聃吕根品何凤荣
Owner DONGGUAN DONGYANG SOLAR SCI RES & DEV CO LTD