Copper alloy plate, copper alloy plate with plating film, and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-11795525-B2
Application number	US-202017438954-A
Country	US
Kind code	B2
Filing date	Mar 25, 2020
Priority date	Mar 29, 2019
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

To improve adhesion between a plating film reducing contact electrical resistance and a copper alloy plate containing Mg. A copper alloy plate containing Mg of more than 1.2% by mass and 2% by mass or less and the balance Cu and inevitable impurities in a center portion in a plate thickness direction, in the copper alloy plate, a surface Mg concentration at a surface is 30% or less of a center Mg concentration at the center portion in the plate thickness direction, a surface layer portion having a depth from the surface to where a Mg concentration is 90% of the center Mg concentration is provided, and in the surface layer portion, the Mg concentration increases from the surface toward the center portion of the plate thickness direction with a concentration gradient of 0.2% by mass/μm or more and 50% by mass/μm or less.

First claim

The invention claimed is:

1. A copper alloy plate containing Mg of more than 1.2% by mass and 2% by mass or less and the balance Cu and inevitable impurities in a center portion in a plate thickness direction, wherein
a surface Mg concentration at a surface is 0% or more and 30% or less of a center Mg concentration at the center portion in the plate thickness direction,
a surface layer portion having a depth from the surface to where a Mg concentration is 90% of the center Mg concentration is provided, and
in the surface layer portion, the Mg concentration increases from the surface toward the center portion of the plate thickness direction with a concentration gradient of 0.2% by mass/μm or more and 50% by mass/μm or less.

2. The copper alloy plate according to claim 1 wherein a thickness of the surface layer portion is 0 μm or more and 9 μm or less.

3. The copper alloy plate according to claim 1 , wherein P is contained 0.001% by mass or more and 0.2% by mass or less.

4. A copper alloy plate with a plating film comprising
a copper alloy plate containing more than 1.2% by mass and 2% by mass or less of Mg in a center portion of a plate thickness direction and the balance of Cu and inevitable impurities, and
a plating film formed on a surface layer portion of the copper alloy plate, wherein
a surface Mg concentration at a surface of the copper alloy plate is 30% or less of a center Mg concentration at the center portion of the plate thickness direction, and
the surface layer portion has a concentration gradient where a Mg concentration increases from the surface toward the center portion of the plate thickness direction with 0.2% by mass/μm or more and 50% by mass/μm or less, and has a depth from the surface to where the Mg concentration is 90% of the center Mg concentration.

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

6. The copper alloy plate with a plating film according to claim 4 , wherein the plating film is formed from one or more layer selected from tin, copper, zinc, nickel, gold, silver, and palladium and alloys thereof.

7. The copper alloy plate with a plating film according to claim 4 , wherein a thickness of the surface layer portion is 9 μm or less.

8. The copper alloy plate with a plating film according to claim 4 , wherein the copper alloy plate contains P of 0.001% by mass or more and 0.2% by mass or less.

9. A manufacturing method of a copper alloy plate comprising
an Mg enrichment treatment forming a surface portion in which Mg is concentrated by diffusing and concentrating Mg on a surface of a copper alloy plate, and
a surface portion removal treatment forming a surface layer portion by removing the surface portion, wherein
the copper alloy plate after the Mg enrichment treatment and the surface portion removal treatment contains Mg more than 1.2% by mass and 2% by mass or less and the balance Cu and inevitable impurities at a center portion of a plate thickness direction;
a surface Mg concentration at a surface of the surface layer portion is 30% or less of a center Mg concentration at the center portion of the plate thickness direction; and
in the surface layer portion, the Mg concentration increases from the surface toward the center portion of the plate thickness direction with a concentration gradient of 0.2% by mass/μm or more and 50% by mass/μm or less, and the surface layer portion has a depth from the surface to where a Mg concentration is 90% of the center Mg concentration.

10. The manufacturing method of a copper alloy plate according to claim 9 wherein a thickness of the surface layer portion is 9 μm or less.

11. The manufacturing method of a copper alloy plate according to claim 9 , wherein the copper alloy plate containing 0.001% by mass or more and 0.2% by mass or less of P.

12. A method of forming the copper alloy plate with a plating film according to claim 4 , wherein
the plating film is formed on the copper alloy plate by an electrolytic plating treatment with a current density of 0.1 A/dm 2 or more and 60 A/dm 2 or less.

13. The method of forming a copper alloy plate with a plating film according to claim 12 , wherein
the plating film contains tin; and
after the electrolytic plating treatment, a reflow treatment is performed at 230° C. or more and 330° C. or less of heating peak temperature, for 0.5 seconds or more and 30 seconds or less of heating time at the heating peak temperature.

Assignees

• Mitsubishi Materials Corp

Inventors

• Miyashima Naoki
• Kobayashi Takanori
• Maki Kazunari
• Funaki Shinichi
• Mori Hiroyuki
• Ito Yuki

Classifications

• C22C9/00 Primary

  Alloys based on copper · CPC title

• B32B15/018

  one layer being formed of a noble metal or a noble metal alloy · CPC title

• B32B15/20

  comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} · CPC title

• C25D5/34

  Pretreatment of metallic surfaces to be electroplated · CPC title

• C25D5/50

  by heat-treatment · CPC title