JP2003082425A - Copper based alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper based alloy which has excellent mechanical properties, electric conductivity, stress relaxation resistance or the like, and is suitable to a terminal and a connector for apparatuses in an automobile or the like. SOLUTION: The copper based alloy contains, by mass, 0.2 to 0.8% Mn, 0.2 to 0.8% Ni and 0.1 to 0.5% P. Alternatively, the copper based alloy further contains one or two kinds of metals selected from 0.05 to 0.5% Sn and 0.05 to 1.0% Zn in the copper based alloy. The alloy elements of Mn, Ni and P are mutually reacted to produce various compounds, and are precipitated into a copper matrix, or, one part thereof is allowed to enter into solid solution to increase the mechanical properties, electric conductivity and stress relaxation resistance of the copper based alloy, and its bending workability and thermal peeling resistance in plating are also satisfactorily maintained. The above characteristics are stabilized particularly when the ratio in mass% of [Mn+Ni] to P is 2.0 to 7.0. By adding a suitable amount of Sn or Zn to the copper based alloy, its mechanical properties are improved, and S remarkably improves its stress relaxation resistance, and Zn remarkably improves its thermal peeling resistance in plating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper-based alloy suitable for terminals and connectors used in in-vehicle equipment, wiring components (switches and relays) for commonly used electronic and electrical equipment, IC lead frames and the like.

[0002]

2. Description of the Related Art In recent years, the number of devices such as navigation systems, airbags and antilock brake systems mounted on automobiles and safety devices has been steadily increasing.
Along with this, in order to make the best use of the vehicle interior space, it is important to package the onboard devices compactly, and there is a strong demand for downsizing of the devices even more than before. Even important equipment has come to be installed not in the car but in the engine room where temperature rises easily. For this reason, the terminals and connectors used in in-vehicle equipment should have improved strength for miniaturization, improved stress relaxation resistance to withstand use at high temperatures, and conductivity to suppress self-heating. Is required to improve. Such improvement in characteristics is also required for wiring components for electronic and electric devices, IC lead frames, and the like, which are being highly integrated.

[0003]

By the way, the terminals and connectors for in-vehicle equipment, wiring parts for electronic and electrical equipment, I
For C lead frames, etc., Cu-Ni-Si alloys,
Cu-Cr type alloys, Cu-Zr type alloys, etc. are used, but Cu-Ni-Si type alloys have low electric conductivity and
-Cr-based alloys and Cu-Zr-based alloys have low strengths, and neither of them can sufficiently meet the strict requirements for characteristics in recent years.

From the above, the present inventors have found that terminals and connectors for in-vehicle equipment, wiring parts for electronic and electrical equipment,
A copper-based alloy suitable for IC lead frames and the like was researched, and the Cu-Mn-Ni-P-based alloy was found to have excellent mechanical properties, electrical conductivity, stress relaxation resistance, etc. Has been completed. The object of the present invention is excellent in mechanical properties, electrical conductivity, stress relaxation resistance, etc., and can sufficiently meet recent severe property requirements, terminals and connectors for in-vehicle equipment, wiring parts for electronic and electrical equipment,
It is to provide a copper-based alloy suitable for IC lead frames and the like.

[0005]

The invention according to claim 1 is
0.2 to 0.8 mass% of Mn and 0.2 to 0.8 ma of Ni
The copper-based alloy is characterized by containing ss% and P in an amount of 0.1 to 0.5 mass% and the balance being Cu and inevitable impurities.

The invention according to claim 2 is characterized in that the mass (mass%) ratio of [Mn + Ni] to P ([Mn + Ni] / P) is 2.0 to 7.0. It is a copper-based alloy.

According to the third aspect of the invention, Mn is 0.2 to.
0.8 mass%, Ni 0.2 to 0.8 mass%, P 0.
1-0.5mass% included, and Sn0.05-0.5ma
The copper-based alloy is characterized by containing any one or two of ss% and Zn of 0.05 to 1.0 mass% and the balance of Cu and unavoidable impurities.

The invention according to claim 4 is characterized in that the mass (mass%) ratio of [Mn + Ni] to P ([Mn + Ni] / P) is 2.0 to 7.0. It is a copper-based alloy.

[0009]

DETAILED DESCRIPTION OF THE INVENTION In the invention described in claim 1, M
The alloying elements of n, Ni, and P react with each other to form various compounds and precipitate in the copper matrix, or part of them form a solid solution, and mechanical properties, conductivity, and resistance of the copper-based alloy are increased. Improves stress relaxation characteristics. On the other hand, in order to reduce the contact resistance of the terminal or connector, it is usually plated, and its heat-resistant peeling property is good, and it is required that the bending workability into a product shape is good. The plating heat-resistant peeling property and bending workability are not impaired.

In the present invention, the contents of Mn and Ni are 0.2 to 0.8 mass% and 0.2 to 0.8 mass%, respectively.
The reason is as follows: No matter which is less than the lower limit, the terminals and connectors for the in-vehicle equipment, the wiring parts for electronic and electrical equipment, I
This is because the mechanical properties and stress relaxation resistance required for the C lead frame and the like cannot be sufficiently obtained, and if the upper limit is exceeded, the electrical conductivity and bending workability deteriorate. Further, the reason for defining the P content to be 0.1 to 0.5 mass% is that Mn and Ni cannot form a compound with P and form a solid solution below the lower limit value, so that conductivity starts and tensile strength and This is because the stress relaxation resistance property deteriorates, and if it exceeds the upper limit, the castability and hot workability deteriorate.

The effect of Mn, Ni and P of the alloy elements is most stably exhibited when the mass (mass%) ratio of [Mn + Ni] to P ([Mn + Ni] / P) is 2.0 to 7.0. To be done. When [Mn + Ni] / P is less than 2.0, the conductivity is slightly lowered, and when it exceeds 7.0, the strength is slightly lowered. The optimum mass ratio is 2.0 to 5.0.

The invention according to claim 3 is the copper-based alloy (C
u-Mn-Ni-P alloy) containing an appropriate amount of Sn and / or Zn. These elements improve mechanical properties, Sn enhances stress relaxation resistance, and Zn is heat-resistant peeling of plating. It also has the effect of enhancing sex. The reason why the Sn content is specified to 0.05 to 0.5 mass% and the Zn content is specified to 0.05 to 1.0 mass% is that the effect is sufficiently obtained when the content is less than the lower limit. The reason is that the conductivity decreases even if either exceeds the upper limit.

In the present invention, in addition to the above-mentioned alloying elements, Cr, Si, Mg, Ag, Co, Fe, Zr, T may be added if necessary.
Elements such as i, V, Pb, Bi, Al, and Ti can be added within a range that does not deteriorate the basic characteristics of the copper-based alloy.

[0014]

EXAMPLES The present invention will be described in detail below with reference to examples. (Example 1) Copper-based alloys (Nos. 1 to 8) having the composition specified in the invention according to claim 1 shown in Table 1 were melted in a high-frequency melting furnace, and were melted by a DC method to have a thickness of 30 mm and a width of 100 m.
m, cast into a 150 mm long ingot, and this ingot is 900
After heating at 60 ° C for 60 minutes for homogenization, start hot rolling at that temperature as it is, and immediately after hot rolling, immediately cool to obtain a hot rolled material with a thickness of 12 mm. After cutting each 1.5 mm to remove the oxide film, it is cold-rolled into a cold-rolled material having a thickness of 0.36 mm.
After heating at 00 ° C. for 15 seconds, immediately followed by heat treatment of cooling at a cooling rate of 15 ° C./second or more and heat treatment of heating at 475 ° C. for 2 hours in this order, and then cold rolling to a thickness of 0.25 mm, Low temperature annealing was performed at 350 ° C. for 2 hours to produce a copper-based alloy sheet material. Both the heat treatment twice and the low temperature annealing of the cold rolled material were performed in an inert gas atmosphere.

Example 2 A copper-based alloy (Nos. 9 to 12) having the composition of the invention according to claim 3 shown in Table 1 was used, except that
A copper-based alloy sheet was manufactured by the same method as in Example 1.

(Comparative Example 1) A copper-based alloy sheet material was produced in the same manner as in Example 1 except that the copper-based alloys (Nos. 13 to 16) having a composition outside the scope of the present invention shown in Table 1 were used.

For each of the copper-based alloy sheet materials produced in Examples 1 and 2 and Comparative Example 1, mechanical properties (tensile strength, elongation), electrical conductivity, stress relaxation resistance, bending workability and plating heat release resistance. I checked. In addition, conventional copper-based alloy sheet materials (Table 1
No. The same investigation was also conducted for 17 to 19). (1) Mechanical properties are specified in JIS Z 2201 5
It was examined according to JIS Z 2241 using a No. test piece. (2) The conductivity was examined according to JIS H 0505. (3) For the stress relaxation resistance, the cantilever block type of Japan Electronic Material Industry Association standard (EMAS-3003) is adopted,
The maximum surface stress was set to 400 N / mm ² and the surface was held in a constant temperature bath at 150 ° C., and the stress relaxation rate (SRR) after holding for 1000 hours was examined. (4) The bending workability is 18 mm when the inner bending radius is 0.1 mm.
Bending was carried out at 0 °, and those having no cracks in the bent portion were judged to be good (◯), and those having cracks were judged to be bad (×). (5) The heat-resistant peeling resistance of the plating was measured by applying gloss Sn plating with a thickness of 3 μm to a test piece and applying 1000 μm at 150 ° C. in the atmosphere.
After heating for a period of time, a 90 ° bending and bending back test was performed, and the adhesion state of Sn plating at the bent portion was visually observed. Good adhesion (○) if the plating did not peel off,
In the case of peeling, it was judged as poor adhesion (x). The results are also shown in Table 1.

[0018]

[Table 1]

As is apparent from Table 1, No. 1 of the invention according to the present invention is described. All of 1 to 8 are required to have the above-mentioned terminals for automobile equipment, connectors, wiring parts for electronic equipment, IC lead frames, etc., and have a tensile strength of 590 N / mm ^2.
As described above, the elongation of 6% or more, the electric conductivity of 55% or more of IACS, and the stress relaxation resistance of 50 or less were satisfied with the immediate target values, and the bending workability and the heat resistant peeling resistance of the plating were excellent.
In particular, N having a mass ratio of [Mn + Ni] / P of 2.0 to 7.0
o. 1, 2, 4, 5, 7, 8 were excellent in tensile strength and conductivity. No. 2 of the invention according to claim 2 of the present application. Nos. 9 to 12 also showed excellent characteristics, and particularly No. Nos. 9 and 10 have stress relaxation resistance characteristics, and No. No. 11 has the heat-resistant peeling resistance of the plating, and No. 11 containing Sn and Zn was added. In No. 12, the stress relaxation resistance and the heat resistant peeling resistance of the plating were greatly improved.
No. of the comparative example. No. 13 has a low Mn content and thus has low tensile strength and stress relaxation resistance. No. 14 has a low P content and thus has low tensile strength, conductivity and stress relaxation resistance. Since No. 15 contained a large amount of P, cracking occurred during hot working and normal production was impossible. In No. 16, since the amount of Ni was large, the conductivity and bending workability were deteriorated. Conventional copper-based alloy sheet material No.
No. 17 (Cu-Ni-Si alloy) has a conductivity of No. 18
(Cu-Mg alloy) has a tensile strength of No. 19 (Cu-
The Sn-Fe alloy) had reduced conductivity and bending workability.

[0020]

As described above, the copper-based alloy of the present invention has excellent mechanical properties, electrical conductivity and stress relaxation resistance,
Bending workability and plating adhesion are also good, so
It can be used well for terminals and connectors for in-vehicle equipment, wiring parts for electronic and electrical equipment, IC lead frames, etc., which require strict characteristics, and has a remarkable industrial effect.

Claims (4)

[Claims] 1. Mn of 0.2 to 0.8 mass%, Ni of 0.2 to 0.8 mass%, P of 0.1 to 0.5 mass%, and the balance being Cu and inevitable impurities. And copper-based alloy. 2. The mass of [Mn + Ni] with respect to P (mass).
%) Ratio ([Mn + Ni] / P) is 2.0 to 7.0. The copper base alloy according to claim 1. 3. Mn of 0.2 to 0.8 mass%, Ni of 0.2 to 0.8 mass%, P of 0.1 to 0.5 mass%, Sn of 0.05 to 0.5 mass%, Zn0 .05
To 1.0 mass% of any one or two of them, and the balance consisting of Cu and unavoidable impurities. 4. A mass of [Mn + Ni] with respect to P (mass).
%) Ratio ([Mn + Ni] / P) is 2.0-7.0, The copper base alloy according to claim 3.