Use of etch resist masked anode frame for facilitation of laser cutting, particle and leakage current reduction

Patent metadata

Field	Value
Publication number	US-2018366276-A1
Application number	US-201816112353-A
Country	US
Kind code	A1
Filing date	Aug 24, 2018
Priority date	Jan 15, 2016
Publication date	Dec 20, 2018
Grant date	—

Abstract

The present invention is directed to a method of etching anode foil in a non-uniform manner which minimizes thermal oxidation during foil cutting. Having less oxide improves the ability to cut through aluminum anodes with lower energy rates. In aluminum foils, it has been found that a masking step before etching reduces conversion of boehmite aluminum oxide to alpha-phase corundum during laser cutting of anodes, which increases edge quality and productivity. Additionally, the non-etched anode frame allows for less surface area to form during the aging process. As a result, the leakage current is reduced by the proportion of edge to anode surface area, and the aging process will be faster, leading to higher productivity.

First claim

What is claimed is:

1 . A metal anode foil etched by the process of:
depositing an etch-resistant mask upon predetermined portions of a metal foil to define a perimeter of an anode; placing the masked metal foil in an etch electrolyte solution; etching said masked metal foil, such that the exposed area is etched; and removing the etch-resistant mask, wherein removing the mask leaves an unetched perimeter.

2 . The metal anode foil of claim 1 , wherein the process further comprising the step of cutting the metal foil along the unetched perimeter, to form an etched anode foil.

3 . The metal anode foil of claim 1 , wherein the etch-resistant mask is selected from the group consisting of an acrylic ink, poly(4-hydroxystyrene), copolymers of 4-hydroxystyrene, novolac resins, fluorocarbon polymers, cycloaliphatic polymers, polyurethane polyols, polyesterurethanes, and cross-linked variants and copolymers and mixtures thereof.

4 . The metal anode foil of claim 1 , wherein the etch-resistant mask is deposited using inkjet printing, lithography, or photolithography.

5 . The metal anode foil of claim 1 , wherein the metal foil is an aluminum foil.

6 . The metal anode foil of claim 1 , wherein removing the etch-resistant mask comprises removing the etch-resistant mask using chemical means.

7 . The metal anode foil of claim 1 , wherein removing the etch-resistant mask comprises removing the etch-resistant mask using ethyl lactate.

8 . The metal anode foil of claim 1 , wherein removing the etch-resistant mask comprises removing the etch-resistant mask using an oven to burn the etch-resistant mask away.

9 . The metal anode foil of claim 1 , wherein depositing the etch, resistant mask upon the predetermined portions of the metal foil to define the perimeter of the anode comprises printing a line having alternating line gaps on the metal foil.

10 . The metal anode foil of claim 1 , wherein depositing the etch-resistant mask upon the predetermined portions of the metal foil to define the perimeter of the anode comprises printing an etch-resistant mask on the metal foil.

11 . The metal anode foil of claim 1 , wherein depositing the etch-resistant mask upon the predetermined portions of the metal foil to define the perimeter of the anode comprises depositing the etch-resistant mask such as to form the mask directly upon the predetermined portions of the metal foil such as to define the perimeter of the anode prior to etching the foil.

12 . A metal anode foil etched by the process of:
depositing an etch-resistant mask directly upon predetermined portions of the metal foil, thereby defining an anode perimeter; placing the masked metal foil in an etch electrolyte solution; etching said masked metal foil, such that the exposed area is etched; removing the etch-resistant mask, wherein removing the etch-resistant mask leaves an unetched perimeter; widening; forming; and cutting the foil along the unetched perimeter, to form an etched anode foil; wherein the cut foil has less thermal oxide formation along the perimeter than a foil cut without masking.

13 . The metal anode foil of claim 12 , wherein the etch-resistant mask is selected from the group consisting of an acrylic ink, poly(4-hydroxystyrene), copolymers of 4-hydroxystyrene, novolac resins, fluorocarbon polymers, cycloaliphatic polymers, polyurethane polyols, polyesterurethanes, and cross-linked variants and copolymers and mixtures thereof.

14 . The metal anode foil of claim 12 , wherein the etch-resistant mask comprises an acrylic ink.

15 . The metal anode foil of claim 12 , wherein the etch-resistant mask is deposited using inkjet printing, lithography, or photolithography.

16 . The metal anode foil of claim 12 , wherein the etch-resistant mask is deposited using inkjet printing.

17 . An etched metal anode foil created by the process of:
applying an etch-resistant mask to predetermined portions of a metal foil to define an anode perimeter; placing the masked metal foil in an etch electrolyte solution; etching said masked metal foil, such that the exposed area is etched; removing the etch-resistant mask, wherein removing the etch-resistant mask leaves an unetched perimeter, widening; forming; and cutting the foil along the unetched perimeter, to form an etched anode foil; wherein the cut foil has less thermal oxide formation along the perimeter than a foil cut without masking, and wherein thermal oxidation of the anode foil is reduced by greater than 99%.

18 . The etched metal anode foil of claim 17 , wherein the process comprises depositing the etch-resistant mask upon an unetched surface of the metal foil.

19 . The etched metal anode foil of claim 17 , wherein the process comprises depositing the etch-resistant mask directly upon an unetched surface of the metal foil.

Assignees

• Pacesetter Inc

Inventors

• Strange Thomas F
• Hemphill Ralph Jason
• Bowen David R
• Erickson Kurt J

Classifications

• H01G9/055

  Etched foil electrodes · CPC title

• H01G9/042 Primary

  characterised by the material (H01G11/22 takes precedence) · CPC title

• H01G9/145 Primary

  Liquid electrolytic capacitors (H01G11/00 takes precedence) · CPC title

• C23F1/14

  Aqueous compositions · CPC title

• H01G9/0029

  Processes of manufacture · CPC title