Method for smoothing surface of copper foil and copper foil obtained

Patent metadata

Field	Value
Publication number	US-2024218554-A1
Application number	US-202318182365-A
Country	US
Kind code	A1
Filing date	Mar 13, 2023
Priority date	Dec 30, 2022
Publication date	Jul 4, 2024
Grant date	—

Abstract

A method for smoothing surfaces of a copper foil and the copper foil obtained are provided, wherein the method for smoothing surfaces of the copper foil includes the following steps. Supplied with a copper foil. A first electropolishing process is performed on the copper foil. The copper foil is subjected to a pickling process. A second electropolishing process is performed on the copper foil.

First claim

What is claimed is:

1 . A method for smoothing a surface of a copper foil, comprising:
providing the copper foil; performing a first electrolytic polishing process on the copper foil; performing a pickling process on the copper foil; and performing a second electrolytic polishing process on the copper foil.

2 . The method according to claim 1 , wherein the pickling process is performed after the first electrolytic polishing process and before the second electrolytic polishing process, and the pickling process comprises the following step:
cleaning the copper foil with a pickling solution having a pH value of −1 to 2.

3 . The method according to claim 2 , wherein the pickling solution comprises phosphoric acid or sulfuric acid, and a content of the phosphoric acid or the sulfuric acid ranges from 2 wt % to 20 wt % based on a total weight of the pickling solution.

4 . The method according to claim 1 , wherein the first electrolytic polishing process comprises the following step:
placing the copper foil in a polishing solution for electrolytic polishing, wherein the polishing solution comprises at least one nitrogen-containing organic additive, and a content of the at least one nitrogen-containing organic additive ranges from 0.0001 wt % to 1 wt % based on a total weight of the polishing solution.

5 . The method according to claim 4 , wherein the at least one nitrogen-containing organic additive comprises urea, 2-mercaptobenzoxazole, benzotriazole, 4-carboxybenzotriazole, 5-aminotetrazole, triazol-3-amine or combinations thereof.

6 . The method according to claim 1 , wherein the first electrolytic polishing process comprises the following conditions: a current density is 5 A/dm 2 to 100 A/dm 2 and a polishing time is 5 s to 40 s.

7 . The method according to claim 1 , wherein the second electrolytic polishing process comprises the following conditions: a current density is 5 A/dm 2 to 80 A/dm 2 and a polishing time is 5 s to 40 s.

8 . The method according to claim 1 , wherein a polishing time of the second electrolytic polishing process is less than a polishing time of the first electrolytic polishing process, and a current density of the second electrolytic polishing process is lower than a current density of the first electrolytic polishing process.

9 . The method according to claim 1 , further comprising:
performing a passivation treatment process on the copper foil after performing the second electrolytic polishing process.

10 . A finished copper foil is obtained by the method according to claim 1 , wherein an average roughness of a surface of the finished copper foil is equal to or less than 1 micrometer.

Assignees

• Nan Ya Plastics Corp

Inventors

• Liao Te-Chao
• Cheng Wei-Sheng
• Wu Chao-Tung

Classifications

• C23G1/103 Primary

  copper or alloys of copper · CPC title

• C25F3/22 Primary

  of heavy metals · CPC title

• C25F3/02

  Etching · CPC title