Composite material, method for producing the composite material, and terminal

Patent metadata

Field	Value
Publication number	US-2025277324-A1
Application number	US-202318861019-A
Country	US
Kind code	A1
Filing date	Apr 5, 2023
Priority date	May 11, 2022
Publication date	Sep 4, 2025
Grant date	—

Abstract

There is provided a composite material in which a composite coating composed of a silver layer containing carbon particles is provided on a base material, wherein when the composite coating is observed with a laser microscope, a proportion of predetermined protrusions in an observation field is 12% or more by area.

First claim

1 . A composite material in which a composite coating composed of a silver layer containing carbon particles is provided on a base material,
wherein when observing the composite coating with a laser microscope to obtain a pixel height, which is a height difference between each pixel constituting an observation field and a lowest pixel in the observation field, and when a pixel height of a pixel whose cumulative number ratio is 10% in an arrangement of pixel heights in an ascending order is defined as a reference height H 0 , and a pixel in the observation field whose pixel height is 1 μm or more higher than the reference height H 0 is defined as a protrusion, a proportion of the protrusions in the observation field is 12% or more by area.

2 . The composite material according to claim 1 , wherein the base material is composed of Cu or a Cu alloy.

3 . The composite material according to claim 1 , wherein a crystallite size of silver in the composite coating is 40 nm or less.

4 . The composite material according to claim 1 , wherein a proportion of the protrusions is 15 to 75% by area.

5 . The composite material according to claim 1 , wherein a proportion of the carbon particles in a composite coating surface is 10 to 80% by area.

6 . The composite material according to claim 1 , wherein a thickness of the composite coating is 1.5 to 25 μm.

7 . The composite material according to claim 1 , wherein the composite coating surface has a Vickers hardness of 100 or more.

8 . The composite material according to claim 1 , wherein the composite coating has an arithmetic mean roughness Ra of 0.6 μm or more.

9 . The composite material according to claim 1 , wherein an underlayer composed of at least one selected from a group consisting of Cu, Ni, Sn, and Ag is provided between the base material and the composite coating.

10 . A method for producing a composite material, comprising:
performing electroplating in a silver plating solution containing carbon particles; and forming a composite coating composed of a silver layer containing carbon particles on a base material, wherein the carbon particles are surface-treated carbon particles that have been treated in an aqueous solution, with compound A represented by the following general formula (1) for 30 minutes or more,

(in formula (1), m is an integer from 1 to 5;
Ra is a carboxyl group;
Rb is an aldehyde group, a carboxyl group, an amino group, a hydroxyl group, or a sulfonic acid group;
Rc is hydrogen or an arbitrary substituent;
when m is 2 or more, multiple Rb's may be the same or different;
when m is 3 or less, multiple Rc's may be the same or different; and
Ra and Rb may each independently be bonded to a benzene ring via a divalent group composed of at least one selected from a group consisting of —O— and —CH 2 —.)

11 . The method for producing a composite material according to claim 10 , wherein the silver plating solution contains the surface-treated carbon particles and a compound B represented by the following general formula (2):

(in formula (2), p is an integer from 1 to 5,
Rd is a carboxyl group,
Re is an aldehyde group, a carboxyl group, an amino group, a hydroxyl group, or a sulfonic acid group,
Rf is hydrogen or an arbitrary substituent,
when p is 2 or more, multiple Re's may be the same or different,
when p is 3 or less, multiple Rf's may be the same or different, and
Rd and Re may each independently be bonded to a benzene ring via a divalent group composed of at least one selected from a group consisting of —O— and —CH 2 —.)

12 . The method for producing a composite material according to claim 10 , wherein the base material is composed of Cu or a Cu alloy.

13 . The method for producing a composite material according to claim 10 , wherein the treatment for the carbon particles with compound A is performed by stirring an aqueous solution containing the carbon particles and compound A for 30 minutes or more.

14 . The method for producing a composite material according to claim 10 , wherein a concentration of compound B in the silver plating solution is 2 to 250 g/L.

15 . The method for producing a composite material according to claim 10 , wherein the silver plating solution contains silver ions at a concentration of 5 to 150 g/L.

16 . The method for producing a composite material according to claim 10 , wherein a concentration of the surface-treated carbon particles in the silver plating solution is 10 to 150 g/L.

17 . A terminal for electrical contacts, the terminal comprising the composite material according to claim 1 as a constituent material.

Assignees

• Dowa Metaltech Co Ltd

Inventors

• Kato Yukiya
• Tomiya Takao
• Kotani Hirotaka
• Takahashi Hirotaka
• Hirayama Airi

Classifications

• C25D3/30

  of tin · 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

• C25D3/38

  of copper · CPC title

• C25D5/12

  at least one layer being of nickel or chromium · CPC title