COPPER ALLOY FOR ELECTRONIC DEVICES, METHOD OF MANUFACTURING COPPER ALLOY FOR ELECTRONIC DEVICES, COPPER ALLOY PLASTIC WORKING MATERIAL FOR ELECTRONIC DEVICES, AND COMPONENT FOR ELECTRONIC DEVICES

• US 20140283962A1
• Filed: 11/07/2012
• Published: 09/25/2014
• Est. Priority Date: 11/07/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Materials Corporation
• Original Assignee: Mitsubishi Materials Corporation
• Inventors: Ito, Yuki, Maki, Kazunari
• Granted Patent: US 10,153,063 B2
• Time in Patent Office: Days
• US Class Current: 148/684
• CPC Class Codes: C22C 9/00 Alloys based on copper
• CPC Class Codes: C22F 1/08 of copper or alloys based thereon
• CPC Class Codes: H01B 1/026 Alloys based on copper

Abstract

A copper alloy for electronic devices has a low Young'"'"'s modulus, high proof stress, high electrical conductivity and excellent bending formability and is appropriate for a component for electronic devices including a terminal, a connector, a relay and a lead frame. Also a method of manufacturing a copper alloy utilizes a copper alloy plastic working material for electronic devices, and a component for electronic devices. The copper alloy includes Mg at 3.3 to 6.9 at %, with a remainder substantially being Cu and unavoidable impurities. When a concentration of Mg is X at %, an electrical conductivity σ (% IACS) is in a range of σ≦{1.7241/(−0.0347×X²+0.6569×X+1.7)}×100, and an average grain size is in a range of 1 μm-100 μm. In addition, an average grain size of a copper material after an intermediate heat treatment and before finishing working is in a range of 1 μm-100 μm.

Claims

1. A copper alloy for electronic devices, consisting of:

a binary alloy of Cu and Mg,

wherein the binary alloy contains Mg at a content of 3.3 at % or more and 6.9 at % or less, with a remainder being Cu and unavoidable impurities,

when a concentration of Mg is given as X at %, an electrical conductivity σ

(% IACS) is in a range of σ

≦

{1.7241/(−

0.0347×

X²+0.6569×

X+1.7)}×

100, and

an average grain size is in a range of 1 μ

m or greater and 100 μ

m or smaller.

3. The copper alloy for electronic devices according to claim 1,

wherein a ratio of a region having a CI value of 0.1 or less is in a range of 80% or less as a measurement result according to an SEM-EBSD method.

4. The copper alloy for electronic devices according to claim 1,

wherein an average number of intermetallic compounds having grain sizes of 0.1 μ

m or greater and mainly containing Cu and Mg is in a range of 1 piece/μ

m² or less during observation by a scanning electron microscope.

5. The copper alloy for electronic devices according to claim 1,

wherein a Young'"'"'s modulus is in a range of 125 GPa or less, and a 0.2% proof stress σ

_0.2 is in a range of 400 MPa or more.

6. A method of manufacturing the copper alloy for electronic devices according to claim 1, the method comprising:

an intermediate working process of subjecting a copper material, which consists of a binary alloy of Cu and Mg and has a composition that contains Mg at a content of 3.3 at % or more and 6.9 at % or less with a remainder being Cu and unavoidable impurities, to cold or warm plastic working into a predetermined shape; and

an intermediate heat treatment process of heat-treating the copper material subjected to the plastic working in the intermediate working process,

wherein an average grain size of the copper material after the intermediate heat treatment process is in a range of 1 μ

m or greater and 100 μ

m or smaller.

7. The method of manufacturing a copper alloy for electronic devices according to claim 6,

wherein, in the intermediate working process, the plastic working is performed at a working ratio of 50% or higher in a range of −

200°

C. to 200°

C., and

in the intermediate heat treatment process, after performing heating to a temperature of 400°

C. or higher and 900°

C. or lower and performing holding for a predetermined time, cooling to a temperature of 200°

C. or lower at a cooling rate of 200°

C./min or higher is performed.

8. A copper alloy plastic working material for electronic devices, consisting of the copper alloy for electronic devices according to claim 1,

wherein a Young'"'"'s modulus E is in a range of 125 GPa or less, and a 0.2% proof stress σ

_0.2 is in a range of 400 MPa or more.

9. The copper alloy plastic working material for electronic devices according to claim 8,

wherein the copper alloy plastic working material is used as a copper material included in a component for electronic devices such as a terminal including a connector, a relay, and a lead frame.

10. A component for electronic devices, comprising the copper alloy for electronic devices according to claim 1.

11. A terminal comprising the copper alloy for electronic devices according to claim 1.

2. A copper alloy for electronic devices, consisting of:

a binary alloy of Cu and Mg,

wherein the binary alloy contains Mg at a content of 3.3 at % or more and 6.9 at % or less, with a remainder being Cu and unavoidable impurities,

when a concentration of Mg is given as X at %, an electrical conductivity σ

(% IACS) is in a range of σ

≦

{1.7241/(−

0.0347×

X²+0.6569×

X+1.7)}×

100, and

an average grain size of a copper material after an intermediate heat treatment and before finishing working is in a range of 1 μ

m or greater and 100 μ

m or smaller.

14. The copper alloy for electronic devices according to claim 2,

wherein a ratio of a region having a CI value of 0.1 or less is in a range of 80% or less as a measurement result according to an SEM-EBSD method.

15. The copper alloy for electronic devices according to claim 2,

wherein an average number of intermetallic compounds having grain sizes of 0.1 μ

m or greater and mainly containing Cu and Mg is in a range of 1 piece/μ

m² or less during observation by a scanning electron microscope.

16. The copper alloy for electronic devices according to claim 2,

wherein a Young'"'"'s modulus is in a range of 125 GPa or less, and a 0.2% proof stress σ

_0.2 is in a range of 400 MPa or more.

17. A method of manufacturing the copper alloy for electronic devices according to claim 2, the method comprising:

an intermediate working process of subjecting a copper material, which consists of a binary alloy of Cu and Mg and has a composition that contains Mg at a content of 3.3 at % or more and 6.9 at % or less with a remainder being Cu and unavoidable impurities, to cold or warm plastic working into a predetermined shape; and

an intermediate heat treatment process of heat-treating the copper material subjected to the plastic working in the intermediate working process,

wherein an average grain size of the copper material after the intermediate heat treatment process is in a range of 1 μ

m or greater and 100 μ

m or smaller.

18. The method of manufacturing a copper alloy for electronic devices according to claim 17,

wherein, in the intermediate working process, the plastic working is performed at a working ratio of 50% or higher in a range of −

200°

C. to 200°

C., and

in the intermediate heat treatment process, after performing heating to a temperature of 400°

C. or higher and 900°

C. or lower and performing holding for a predetermined time, cooling to a temperature of 200°

C. or lower at a cooling rate of 200°

C./min or higher is performed.

19. The copper alloy plastic working material for electronic devices, consisting of the copper alloy for electronic devices according to claim 2,

wherein a Young'"'"'s modulus E is in a range of 125 GPa or less, and a 0.2% proof stress σ

_0.2 is in a range of 400 MPa or more.

20. The copper alloy plastic working material for electronic devices according to claim 19,

wherein the copper alloy plastic working material is used as a copper material included in a component for electronic devices such as a terminal including a connector, a relay, and a lead frame.

21. The component for electronic devices, comprising the copper alloy for electronic devices according to claim 2.

22. The terminal comprising the copper alloy for electronic devices according to claim 2.

12-13. -13. (canceled)