Copper alloy sheet, copper alloy sheet with plating film, and method for producing same

Patent metadata

Field	Value
Publication number	US-11920228-B2
Application number	US-202017784062-A
Country	US
Kind code	B2
Filing date	Dec 8, 2020
Priority date	Dec 10, 2019
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

Providing a copper alloy plate, in which center Mg concentration at a center part in a plate thickness direction 0.1 mass % or more and less than 0.3 mass %, center P concentration is 0.001 mass % or more and 0.2 mass % or less, and the balance is composed of Cu and inevitable impurities; in which surface Mg concentration at a surface is 70% or less of the center Mg concentration; in which a surface layer part defined by a prescribed thickness from the surface has a concentration gradient of Mg of 0.05 mass %/μm or more and 5 mass %/μm or less increasing from surface toward center part of the plate thickness direction; and in which restraint of color change of the surface and increase of electrical contact resistance, and adhesiveness of a plating film are excellent due to maximum Mg concentration in the surface layer part is 90% of the center Mg concentration.

First claim

The invention claimed is:

1. A copper alloy plate, wherein
in a center part in a plate thickness direction, a center Mg concentration is 0.1 mass % or more and less than 0.3 mass %, a center P concentration is 0.001 mass % or more and 0.2 mass % or less, and the balance Cu and inevitable impurities,
a surface Mg concentration on a surface is 70% or less of the center Mg concentration, and
a surface layer part defined by a prescribed thickness from the surface has a concentration gradient of Mg concentration increasing from the surface toward the center part in the plate thickness direction at 0.05 mass %/μm or more and 5 mass %/μm or less, and Mg concentration in a deepest part is 90% of the center Mg concentration.

2. The copper alloy plate according to claim 1 wherein the thickness of the surface layer part is 5 μm or less.

3. A copper alloy plate with a plating film having the copper alloy plate described in claim 1 and a plating film formed on the surface layer part.

4. The copper alloy plate with a plating film according to claim 3 , wherein an average Mg concentration in the plating film is 10% or less of the center Mg concentration.

5. The copper alloy plate with a plating film according to claim 3 , wherein the plating film is configured from one or more layers selected from tin, copper, zinc, nickel, gold, silver, palladium, and alloy of two or more of them.

6. The copper alloy plate with a plating film according to claim 3 , wherein the thickness of the surface layer part is 5 μm or less.

7. A method of producing a copper alloy plate according to claim 1 , comprising
Mg concentration treatment for a copper alloy plate material wherein Mg concentration is 0.1 mass % or more and less than 0.3 mass %, P concentration is 0.001 mass % or more and 0.2 mass % or less, and the balance is composed of Cu and inevitable impurities, forming a surface part where Mg is concentrated by diffusing Mg to a surface, and
surface part removal treatment forming the surface layer part by removing the surface part where Mg is concentrated.

8. The method of producing a copper alloy plate according to claim 7 , wherein the thickness of the surface layer part formed by the surface part removal treatment is 5 μm or less.

Assignees

• Mitsubishi Materials Corp

Inventors

• AKISAKA Yoshiteru
• Miyashima Naoki
• Maki Kazunari
• Funaki Shinichi

Classifications

• C22C9/00 Primary

  Alloys based on copper · CPC title

• C22F1/08

  of copper or alloys based thereon · CPC title

• C25D5/34

  Pretreatment of metallic surfaces to be electroplated · CPC title

• C25D5/10

  Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10) · CPC title

• C23F17/00

  Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by subclass C21D or C22F or class C25 (coating for obtaining at least two superposed coatings either by methods not provided for in a single one of main groups C23C2/00 - C23C26/00, or by combinations of methods providedfor in subclasses C23C and C25D, C23C28/00) · CPC title