JP5910790B1 - Copper alloy for electronic and electric equipment, copper alloy plastic working material for electronic and electric equipment, parts for electronic and electric equipment, terminals, and bus bars - Google Patents

Abstract

[PROBLEMS] To provide a copper alloy for electronic / electric equipment, copper alloy plastic processing material for electronic / electric equipment, electronic / electric equipment parts, terminals, excellent electrical conductivity, strength, bending workability, stress relaxation resistance, and castability. And provide a bus bar. Mg is contained in a range of 0.15 mass% or more and less than 0.35 mass%, P is contained in a range of 0.0005 mass% or more and less than 0.01 mass%, and the balance is composed of Cu and inevitable impurities. The content [Mg] and the content [P] of P satisfy the relationship of [Mg] + 20 × [P] <0.5 by mass ratio, and the electrical conductivity is more than 75% IACS. . [Selection figure] None

Description

  The present invention relates to a copper alloy for electronic / electrical devices suitable for electronic frames such as lead frames, terminals such as connectors and press-fit, bus bars, etc., and electronic / electrical products made of this copper alloy for electronic / electrical devices. The present invention relates to a plastic alloy material for equipment, parts for electronic and electrical equipment, terminals, and bus bars.

Conventionally, copper or copper alloy having high conductivity is used for electronic / electric equipment parts such as terminals such as connectors and press fits, relays, lead frames, bus bars and the like.
Here, along with the downsizing of electronic devices and electrical devices, parts for electronic and electrical devices used in these electronic devices and electrical devices are being made smaller and thinner. For this reason, the material which comprises the components for electronic / electrical devices is calculated | required by high intensity | strength and favorable bending workability. In addition, stress relaxation resistance is also required for connector terminals used in high-temperature environments such as automobile engine rooms.

  Here, as materials used for electronic and electrical equipment parts such as terminals such as connectors and press-fit, relays, lead frames and bus bars, for example, Patent Documents 1 and 2 propose Cu-Mg alloys. Yes.

JP 2007-056297 A JP 2014-114464 A

However, in the Cu-Mg alloy described in Patent Document 1, since the P content is as large as 0.08 to 0.35 mass%, cold workability and bending workability are insufficient, It was difficult to mold a part for electronic / electrical equipment of the shape.
Moreover, in the Cu-Mg alloy described in Patent Document 2, the Mg content is 0.01 to 0.5 mass%, and the P content is 0.01 to 0.5 mass%. From this, coarse crystallized products were formed, and cold workability and bending workability were insufficient.
Furthermore, in the above-mentioned Cu—Mg-based alloy, the viscosity of the copper alloy melt is increased by Mg, so that there is a problem that castability is lowered unless P is added.

  The present invention has been made in view of the above-described circumstances, and is a copper alloy for electronic / electric equipment, which is excellent in conductivity, strength, bending workability, stress relaxation resistance, and castability, and electronic / electric equipment. An object of the present invention is to provide a copper alloy plastic working material, a part for electronic / electric equipment, a terminal, and a bus bar.

  In order to solve this problem, as a result of intensive studies by the present inventors, by setting the contents of Mg and P contained in the alloy within the range of a predetermined relational expression, crystals containing Mg and P It was found that coarsening of the extract was suppressed, and it was possible to improve strength, stress relaxation resistance, and castability without reducing workability.

The present invention has been made on the basis of the above-mentioned knowledge, and the copper alloy for electronic / electric equipment of the present invention has Mg in the range of 0.15 mass% to less than 0.35 mass%, and P in the range of 0.0005 mass%. In the range of less than 0.01 mass%, the balance is made of Cu and inevitable impurities, and the Mg content [Mg] and the P content [P] are in a mass ratio.
[Mg] + 20 × [P] <0.5
And the electrical conductivity exceeds 75% IACS.

According to the copper alloy for electronic and electrical equipment having the above-described configuration, the Mg content is in the range of 0.15 mass% or more and less than 0.35 mass%, so that Mg is dissolved in the copper matrix. As a result, the strength and stress relaxation resistance can be improved without greatly reducing the electrical conductivity.
Moreover, since P is contained in the range of 0.0005 mass% or more and less than 0.01 mass%, castability can be improved.
And Mg content [Mg] and P content [P] are mass ratios,
[Mg] + 20 × [P] <0.5
Therefore, the production of coarse crystals including Mg and P can be suppressed, and the cold workability and bending workability can be prevented from being lowered.
In addition, since the electrical conductivity exceeds 75% IACS, it can be applied to applications that conventionally use pure copper.

Here, in the copper alloy for electronic and electrical equipment of the present invention, the Mg content [Mg] and the P content [P] are in mass ratio,
[Mg] / [P] ≦ 400
It is preferable to satisfy the relationship.
In this case, the castability can be reliably improved by defining the ratio of the Mg content that lowers the castability and the P content that improves the castability as described above.

In the copper alloy for electronic / electric equipment of the present invention, it is preferable that the 0.2% proof stress is 300 MPa or more.
In this case, since the 0.2% proof stress is 300 MPa or more, it is not easily deformed, and is a copper alloy for electronic and electrical equipment parts such as connectors, press-fit terminals, relays, lead frames, bus bars, etc. Particularly suitable as.

Moreover, in the copper alloy for electronic / electric equipment of this invention, it is preferable that a residual stress rate is 50% or more at 150 degreeC and 1000 hours.
In this case, since the residual stress rate is defined as described above, permanent deformation can be suppressed to a small level even when used in a high temperature environment, and for example, a decrease in contact pressure of a connector terminal or the like is suppressed. be able to. Therefore, it can be applied as a material for electronic device parts used in a high temperature environment such as an engine room.

The copper alloy plastic working material for electronic / electric equipment of the present invention is characterized by comprising the above-described copper alloy for electronic / electric equipment.
According to the copper alloy plastic working material for electronic / electric equipment of this configuration, since it is composed of the above-mentioned copper alloy for electronic / electric equipment, it has excellent conductivity, strength, bending workability, and stress relaxation resistance. It is particularly suitable as a material for electronic and electrical equipment parts such as connectors, press-fit terminals, relays, lead frames, bus bars and the like.

Here, in the copper alloy plastic working material for electronic / electric equipment of this invention, it is preferable to have a Sn plating layer or an Ag plating layer on the surface.
In this case, since it has a Sn plating layer or an Ag plating layer on the surface, it is particularly suitable as a material for components for electronic and electrical equipment such as terminals such as connectors and press fits, relays, lead frames, bus bars and the like. In the present invention, “Sn plating” includes pure Sn plating or Sn alloy plating, and “Ag plating” includes pure Ag plating or Ag alloy plating.

The component for electronic / electrical equipment of the present invention is characterized by comprising the above-described copper alloy plastic working material for electronic / electrical equipment. The electronic / electric device parts in the present invention include terminals such as connectors and press-fit, relays, lead frames, bus bars, and the like.
The electronic / electrical device parts with this structure are manufactured using the above-mentioned copper alloy plastic working material for electronic / electrical devices, so that they exhibit excellent characteristics even when downsized and thinned. Can do.

The terminal of the present invention is characterized by comprising the above-described copper alloy plastic working material for electronic and electrical equipment.
Since the terminal of this structure is manufactured using the above-mentioned copper alloy plastic working material for electronic and electrical equipment, it can exhibit excellent characteristics even when it is downsized and thinned.

The bus bar of the present invention is characterized by comprising the above-described copper alloy plastic working material for electronic and electrical equipment.
Since the bus bar having this configuration is manufactured using the above-described copper alloy plastic working material for electronic and electrical equipment, it can exhibit excellent characteristics even when it is downsized and thinned.

  According to the present invention, copper alloy for electronic / electric equipment, copper alloy plastic working material for electronic / electric equipment, electronic / electric equipment excellent in electrical conductivity, strength, bending workability, stress relaxation resistance, and castability Parts, terminals, and bus bars can be provided.

It is a flowchart of the manufacturing method of the copper alloy for electronic and electric apparatuses which is this embodiment.

Below, the copper alloy for electronic and electric apparatuses which is one Embodiment of this invention is demonstrated.
The copper alloy for electronic / electrical equipment according to this embodiment includes Mg in a range of 0.15 mass% to less than 0.35 mass%, P in a range of 0.0005 mass% to less than 0.01 mass%, and the balance being It has a composition consisting of Cu and inevitable impurities.

And Mg content [Mg] and P content [P] are mass ratios,
[Mg] + 20 × [P] <0.5
Have the relationship.
Furthermore, in the present embodiment, the Mg content [Mg] and the P content [P] are in a mass ratio,
[Mg] / [P] ≦ 400
Have the relationship.

Moreover, in the copper alloy for electronic / electrical equipment which is this embodiment, the electrical conductivity exceeds 75% IACS.
Furthermore, in the copper alloy for electronic / electric equipment according to the present embodiment, the 0.2% yield strength when the tensile test is performed in the direction orthogonal to the rolling direction is set to 300 MPa or more. That is, in this embodiment, it is a rolled material of a copper alloy for electronic / electrical equipment, and the 0.2% yield strength when a tensile test is performed in a direction orthogonal to the rolling direction in the final rolling process is as described above. It is defined as follows.
Moreover, in the copper alloy for electronic / electrical equipment which is this embodiment, the residual stress rate is set to 50% or more at 150 ° C. for 1000 hours.

  Here, the reason for defining the component composition as described above will be described below.

(Mg: 0.15 mass% or more and less than 0.35 mass%)
Mg is an element having an action of improving strength and stress relaxation resistance while maintaining high electrical conductivity by being dissolved in a parent phase of a copper alloy.
Here, when the content of Mg is less than 0.15 mass%, there is a possibility that the effect cannot be sufficiently achieved. On the other hand, when the Mg content is 0.35 mass% or more, the electrical conductivity is greatly lowered, the viscosity of the molten copper alloy is increased, and castability may be lowered.
From the above, in the present embodiment, the Mg content is set within a range of 0.15 mass% or more and less than 0.35 mass%.
In order to further improve the strength and the stress relaxation resistance, the lower limit of the Mg content is preferably set to 0.18 mass% or more, and more preferably set to 0.2 mass% or more. Moreover, in order to suppress reliably the fall of electroconductivity and a castability, it is preferable to make the upper limit of content of Mg into 0.32 mass% or less, and it is further more preferable to set it as 0.3 mass% or less.

(P: 0.0005 mass% or more and less than 0.01 mass%)
P is an element having an effect of improving castability.
Here, when content of P is less than 0.0005 mass%, there exists a possibility that the effect cannot be fully achieved. On the other hand, when the content of P is 0.01 mass% or more, a coarse crystallized product containing Mg and P is generated. This crystallized product becomes a starting point of fracture, and during cold working or bending. There is a risk of cracking during processing.
From the above, in the present embodiment, the P content is set in the range of 0.0005 mass% or more and less than 0.01 mass%. In order to surely improve the castability, the lower limit of the P content is preferably 0.001 mass% or more, and more preferably 0.002 mass% or more. Moreover, in order to suppress the production | generation of a coarse crystallized substance reliably, it is preferable to make the upper limit of P content into less than 0.009 mass%, and it is further more preferable to set it as less than 0.008 mass%. It is most preferable to set it to 0075 mass% or less.

([Mg] + 20 × [P] <0.5)
As described above, coexistence of Mg and P produces a crystallized product containing Mg and P.
Here, when the Mg content [Mg] and the P content [P] are [Mg] + 20 × [P] is 0.5 or more in terms of mass ratio, The total amount is large, and crystallized substances containing Mg and P are coarsened and distributed in high density, and there is a risk that cracks are likely to occur during cold working or bending.
From the above, in this embodiment, [Mg] + 20 × [P] is set to less than 0.5. Note that [Mg] + 20 × [P] is set to 0.48 in order to reliably suppress the coarsening and densification of the crystallized product and to suppress the occurrence of cracks during cold working or bending. It is preferably less than 0.46, more preferably less than 0.46.

([Mg] / [P] ≦ 400)
Mg is an element that has the effect of increasing the viscosity of the molten copper alloy and lowering the castability. Therefore, in order to reliably improve the castability, it is necessary to optimize the ratio of the contents of Mg and P. There is.
Here, when the Mg content [Mg] and the P content [P] are [M], and the [Mg] / [P] exceeds 400, the Mg content relative to the P There is a possibility that the castability improvement effect by the addition of P becomes small.
From the above, in this embodiment, [Mg] / [P] is set to 400 or less. In order to further improve the castability, [Mg] / [P] is preferably 350 or less, and more preferably 300 or less.
In addition, when [Mg] / [P] is excessively low, Mg is consumed as a crystallized product, and there is a possibility that the effect due to solid solution of Mg cannot be obtained. In order to suppress generation of crystallized substances containing Mg and P, and to surely improve the yield strength and stress relaxation resistance due to solid solution of Mg, the lower limit of [Mg] / [P] is set to more than 20 Is more preferable, and it is more preferable that it is more than 25.

(Inevitable impurities: 0.1 mass% or less)
Other inevitable impurities include Ag, B, Ca, Sr, Ba, Sc, Y, rare earth elements, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru , Os, Co, Se, Te, Rh, Ir, Ni, Pd, Pt, Au, Zn, Cd, Hg, Al, Ga, In, Ge, Sn, As, Sb, Tl, Pb, Bi, Be, N , C, Si, Li, H, O, S and the like. Since these inevitable impurities have the effect of lowering the conductivity, the total amount is set to 0.1 mass% or less.
In addition, Ag, Zn, and Sn are easily mixed in copper to lower the electrical conductivity, so that the total amount is preferably less than 500 massppm.
Furthermore, since Si, Cr, Ti, Zr, Fe, and Co particularly reduce the electrical conductivity greatly and deteriorate the bending workability due to the formation of inclusions, the total amount of these elements is preferably less than 500 massppm.

(Conductivity: over 75% IACS)
In the copper alloy for electronic and electrical equipment according to this embodiment, by setting the conductivity to exceed 75% IACS, as a part for electronic and electrical equipment such as a connector, a terminal such as a press fit, a relay, a lead frame, a bus bar, etc. Can be used well.
The electrical conductivity is preferably more than 76% IACS, more preferably more than 77% IACS, and more preferably more than 78% IACS.

(0.2% proof stress: 300 MPa or more)
In the copper alloy for electronic / electric equipment according to the present embodiment, when the 0.2% proof stress is 300 MPa or more, terminals for connectors, press-fit, etc., components for electronic / electric equipment such as relays, lead frames, bus bars, etc. Especially suitable as a material for In the present embodiment, the 0.2% yield strength when the tensile test is performed in the direction orthogonal to the rolling direction is set to 300 MPa or more.
Here, the 0.2% yield strength described above is preferably 325 MPa or more, and more preferably 350 MPa or more.

(Residual stress ratio: 50% or more)
In the copper alloy for electronic devices according to the present embodiment, as described above, the residual stress rate is set to 50% or more at 150 ° C. for 1000 hours.
When the residual stress rate under these conditions is high, permanent deformation can be suppressed even when used in a high temperature environment, and a decrease in contact pressure can be suppressed. Therefore, the copper alloy for electronic devices according to the present embodiment can be applied as a terminal used in a high temperature environment such as around the engine room of an automobile. In the present embodiment, the residual stress ratio obtained by performing the stress relaxation test in the direction orthogonal to the rolling direction is set to 50% or more at 150 ° C. for 1000 hours.
The residual stress rate is preferably 60% or more at 150 ° C. and 1000 hours, and more preferably 70% or more at 150 ° C. and 1000 hours.

  Next, a manufacturing method of the copper alloy for electronic / electric equipment according to the present embodiment having such a configuration will be described with reference to the flowchart shown in FIG.

(Melting / Casting Process S01)
First, the above-described elements are added to a molten copper obtained by melting a copper raw material to adjust the components, thereby producing a molten copper alloy. In addition, an element simple substance, a mother alloy, etc. can be used for the addition of various elements. Moreover, you may melt | dissolve the raw material containing the above-mentioned element with a copper raw material. Moreover, you may use the recycling material and scrap material of this alloy. Here, the molten copper is preferably so-called 4NCu having a purity of 99.99 mass% or more, or so-called 5NCu having a purity of 99.999 mass% or more. In the melting process, in order to suppress the oxidation of Mg and to reduce the hydrogen concentration, the atmosphere is dissolved in an inert gas atmosphere (for example, Ar gas) having a low vapor pressure of H ₂ O, and the holding time at the time of melting is minimized. It is preferable that the

Then, the copper alloy molten metal whose components are adjusted is poured into a mold to produce an ingot. In consideration of mass production, it is preferable to use a continuous casting method or a semi-continuous casting method.
At this time, since a crystallized product containing Mg and P is formed during solidification of the molten metal, it is possible to make the crystallized product size finer by increasing the solidification rate. Therefore, the cooling rate of the molten metal is preferably 0.1 ° C./sec or more, more preferably 0.5 ° C./sec or more, and most preferably 1 ° C./sec or more.

(Homogenization / Solution Step S02)
Next, heat treatment is performed for homogenization and solution of the obtained ingot. In the ingot, there may be an intermetallic compound or the like mainly composed of Cu and Mg generated by Mg segregating and concentrating in the solidification process. Therefore, in order to eliminate or reduce these segregation and intermetallic compounds, etc., by performing a heat treatment to heat the ingot to 300 ° C. or more and 900 ° C. or less, Mg can be uniformly diffused in the ingot. Mg is dissolved in the matrix. The heating step S02 is preferably performed in a non-oxidizing or reducing atmosphere.

Here, when the heating temperature is less than 300 ° C., solutionization is incomplete, and a large amount of intermetallic compounds mainly containing Cu and Mg may remain in the matrix phase. On the other hand, when the heating temperature exceeds 900 ° C., a part of the copper material becomes a liquid phase, and the structure and the surface state may become non-uniform. Therefore, the heating temperature is set in the range of 300 ° C. or higher and 900 ° C. or lower.
In addition, in order to improve the efficiency of rough rolling described later and to make the structure uniform, hot working may be performed after the above-described homogenization / solution forming step S02. In this case, the processing method is not particularly limited, and for example, rolling, wire drawing, extrusion, groove rolling, forging, pressing, and the like can be employed. The hot working temperature is preferably in the range of 300 ° C. or higher and 900 ° C. or lower.

(Roughing process S03)
In order to process into a predetermined shape, rough processing is performed. The temperature condition in this roughing step S03 is not particularly limited, but is in the range of −200 ° C. to 200 ° C., which is cold or warm rolled to suppress recrystallization or improve dimensional accuracy. It is preferable to use normal temperature. The processing rate is preferably 20% or more, and more preferably 30% or more. Moreover, there is no limitation in particular about a processing method, For example, rolling, wire drawing, extrusion, groove rolling, forging, a press, etc. are employable.

(Intermediate heat treatment step S04)
After the rough machining step S03, heat treatment is performed for the purpose of thorough solution treatment, recrystallization structure, or softening for improving workability. The heat treatment method is not particularly limited, but the heat treatment is preferably performed in a non-oxidizing atmosphere or a reducing atmosphere at a holding temperature of 400 ° C. to 900 ° C. and a holding time of 10 seconds to 10 hours. Moreover, the cooling method after heating is not particularly limited, but it is preferable to adopt a method such as water quenching in which the cooling rate is 200 ° C./min or more.
Note that the roughing step S03 and the intermediate heat treatment step S04 may be repeatedly performed.

(Finishing process S05)
Finishing is performed to process the copper material after the intermediate heat treatment step S04 into a predetermined shape. Note that the temperature condition in the finishing step S05 is not particularly limited, but is in the range of −200 ° C. to 200 ° C., which is cold or warm processing to suppress recrystallization or softening. In particular, room temperature is preferable. Further, the processing rate is appropriately selected so as to approximate the final shape, but in order to improve the strength by work hardening in the finishing processing step S05, the processing rate is preferably set to 20% or more. Also. When further improving the strength, the processing rate is more preferably 30% or more, and the processing rate is more preferably 40% or more.

(Finish heat treatment step S06)
Next, a finishing heat treatment is performed on the plastic workpiece obtained in the finishing step S05 in order to improve stress relaxation resistance and low-temperature annealing hardening, or to remove residual strain.
The heat treatment temperature is preferably in the range of 100 ° C. or higher and 800 ° C. or lower. In this finishing heat treatment step S06, it is necessary to set heat treatment conditions (temperature, time, cooling rate) so as to avoid a significant decrease in strength due to recrystallization. For example, it is preferable to hold at 300 ° C. for about 1 to 120 seconds. This heat treatment is preferably performed in a non-oxidizing atmosphere or a reducing atmosphere.
The method of heat treatment is not particularly limited, but short-time heat treatment using a continuous annealing furnace is preferable from the viewpoint of reducing the manufacturing cost.
Furthermore, the above-described finishing processing step S05 and finishing heat treatment step S06 may be repeated.

  In this manner, a rolled plate (thin plate) is produced as the copper alloy plastic working material for electronic / electric equipment according to the present embodiment. The thickness of the copper alloy plastic working material (thin plate) for electronic / electric equipment is within a range of 0.05 mm to 3.0 mm, preferably within a range of 0.1 mm to less than 3.0 mm. It is said that. If the thickness of the copper alloy plastic working material (thin plate) for electronic / electric equipment is 0.05mm or less, it is not suitable for use as a conductor in high current applications, and if the thickness exceeds 3.0mm , Press punching becomes difficult.

Here, the copper alloy plastic working material for electronic and electrical equipment according to the present embodiment may be used as it is for a part for electronic and electrical equipment, but the film thickness is 0.1 to An Sn plating layer or an Ag plating layer of about 100 μm may be formed. At this time, it is preferable that the plate thickness of the copper alloy plastic working material for electronic / electric equipment is 10 to 1000 times the plating layer thickness.
Furthermore, by using a copper alloy for electronic / electric equipment (copper alloy plastic working material for electronic / electric equipment) according to the present embodiment as a raw material, for example, a terminal such as a connector or a press fit, Components for electronic and electrical equipment such as relays, lead frames and bus bars are molded.

According to the copper alloy for electronic and electrical equipment according to the present embodiment configured as described above, the Mg content is in the range of 0.15 mass% or more and less than 0.35 mass%. When Mg is dissolved in the matrix, the strength and stress relaxation resistance can be improved without greatly reducing the electrical conductivity.
Moreover, since P is contained in the range of 0.0005 mass% or more and less than 0.01 mass%, castability can be improved.

Since the Mg content [Mg] and the P content [P] satisfy the relationship of [Mg] + 20 × [P] <0.5 by mass ratio, the coarse crystals of Mg and P Generation | occurrence | production of a product can be suppressed and it can suppress that cold work property and bending workability fall.
Furthermore, in this embodiment, the Mg content [Mg] and the P content [P] are in a mass ratio and satisfy the relationship [Mg] / [P] ≦ 400. The ratio between the content of P and the content of P that improves castability is optimized, and the castability can be reliably improved by the effect of addition of P.

Furthermore, in the copper alloy for electronic and electrical equipment according to the present embodiment, the 0.2% proof stress when the tensile test is performed in the direction orthogonal to the rolling direction is 300 MPa or more, and the conductivity exceeds 75% IACS. Therefore, it is particularly suitable as a material for electronic / electric equipment parts such as connectors, press-fit terminals, relays, lead frames, bus bars and the like.
In addition, in the copper alloy for electronic and electrical equipment according to the present embodiment, the residual stress ratio is 50% or more at 150 ° C. for 1000 hours, so that permanent deformation occurs even when used in a high temperature environment. For example, a decrease in contact pressure of a connector terminal or the like can be suppressed. Therefore, it can be applied as a material for electronic device parts used in a high temperature environment such as an engine room.

In addition, since the copper alloy plastic working material for electronic / electric equipment according to the present embodiment is composed of the above-described copper alloy for electronic / electric equipment, the copper alloy plastic working material for electronic / electric equipment is bent. By performing the above, it is possible to manufacture parts for electronic and electrical equipment such as terminals such as connectors and press-fit, relays, lead frames, and bus bars.
In addition, when an Sn plating layer or an Ag plating layer is formed on the surface, it is particularly suitable as a material for electronic / electric equipment parts such as terminals such as connectors and press-fit, relays, lead frames, bus bars, and the like.

  Furthermore, the electronic / electrical device parts (terminals such as connectors and press-fit, relays, lead frames, bus bars, etc.) according to the present embodiment are made of the above-described copper alloy for electronic / electrical devices. Even when the thickness is reduced, excellent characteristics can be exhibited.

As described above, the copper alloy for electronic / electric equipment, the copper alloy plastic working material for electronic / electric equipment, and the electronic / electric equipment parts (terminal, bus bar, etc.) according to the embodiment of the present invention have been described. It is not limited and can be changed as appropriate without departing from the technical idea of the invention.
For example, in the above-described embodiment, an example of a method for producing a copper alloy for electronic / electric equipment has been described. However, the method for producing a copper alloy for electronic / electric equipment is not limited to that described in the embodiment. The existing manufacturing method may be selected as appropriate.

Below, the result of the confirmation experiment performed in order to confirm the effect of this invention is demonstrated.
A copper raw material made of oxygen-free copper (ASTM B152 C10100) having a purity of 99.99 mass% or more was prepared, charged in a high-purity graphite crucible, and high-frequency melted in an atmosphere furnace having an Ar gas atmosphere. Various additive elements were added to the obtained molten copper to prepare the component compositions shown in Table 1, and poured into a mold to produce an ingot. Inventive Example 1 and Comparative Example 3 are heat insulating material (isowool) molds, Inventive Example 11 is a carbon mold, Inventive Examples 2 to 10 and 12 to 21 are copper alloy molds having a water-cooling function. Used as. The size of the ingot was about 20 mm thick x about 150 mm wide x about 70 mm long.
The vicinity of the cast surface of the ingot was chamfered, and the ingot was cut out and the size was adjusted so that the thickness of the final product was 0.5 mm.
The block was heated in an Ar gas atmosphere for 4 hours under the temperature conditions shown in Table 2 to perform homogenization / solution treatment.

Then, after carrying out rough rolling on the conditions described in Table 2, it heat-processed on the temperature conditions described in Table 2 using the salt bath.
The heat-treated copper material was appropriately cut into a shape suitable for the final shape, and surface grinding was performed to remove the oxide film. Thereafter, finish rolling (finishing) was performed at room temperature at a rolling rate described in Table 2 to produce a thin plate having a thickness of 0.5 mm, a width of about 150 mm, and a length of 200 mm.
Then, after finish rolling (finishing), finish heat treatment was performed in an Ar atmosphere under the conditions shown in Table 2, and then water quenching was performed to create a thin plate for property evaluation.

(Castability)
As an evaluation of castability, the presence or absence of rough skin at the time of casting was observed. The case where no or almost no skin roughness was visually observed was indicated by ◎, the case where a small skin roughness less than 1 mm in depth occurred was indicated by ◯, and the case where skin roughness was caused by a depth of 1 mm or more and less than 2 mm was indicated by Δ. Moreover, the thing where big skin roughness more than depth 2mm generate | occur | produced was made into x, and evaluation was stopped on the way. The evaluation results are shown in Table 3.
In addition, the depth of rough skin is the depth of rough skin which goes to the center part from the edge part of an ingot.

(Mechanical properties)
A No. 13B test piece defined in JIS Z 2241 was collected from the strip for characteristic evaluation, and 0.2% proof stress was measured by the offset method of JIS Z 2241. The test piece was collected in a direction perpendicular to the rolling direction. The evaluation results are shown in Table 3.

(conductivity)
A test piece having a width of 10 mm and a length of 150 mm was taken from the strip for characteristic evaluation, and the electric resistance was determined by a four-terminal method. Moreover, the dimension of the test piece was measured using the micrometer, and the volume of the test piece was calculated. And electrical conductivity was computed from the measured electrical resistance value and volume. In addition, the test piece was extract | collected so that the longitudinal direction might become perpendicular | vertical with respect to the rolling direction of the strip for characteristic evaluation. The evaluation results are shown in Table 3.

(Bending workability)
Bending was performed in accordance with four test methods of Japan Copper and Brass Association Technical Standard JCBA-T307: 2007. A plurality of test pieces having a width of 10 mm and a length of 30 mm are taken from the thin sheet for characteristic evaluation so that the bending axis is perpendicular to the rolling direction, the bending angle is 90 degrees, and the bending radius is 0.5 mm (R / A W-bending test was performed using a W-shaped jig of t = 1).
Judgment is made as “X” when a crack is observed by visually observing the outer periphery of the bent portion, “◯” when a large wrinkle is observed, and “◎” when a fracture, a fine crack, or a large wrinkle cannot be confirmed. It was. In addition, (double-circle) and (circle) were judged to be the allowable bending workability. The evaluation results are shown in Table 3.

(Stress relaxation characteristics)
In the stress relaxation resistance test, stress was applied by a method according to the cantilevered screw method of Japan Copper and Brass Association Technical Standard JCBA-T309: 2004, and the residual stress ratio after holding for 1000 hours at a temperature of 150 ° C. was measured. . The evaluation results are shown in Table 3.
As a test method, a specimen (width 10 mm) is taken from each characteristic evaluation strip in a direction orthogonal to the rolling direction, and the initial deflection displacement is set so that the maximum surface stress of the specimen is 80% of the proof stress. The span length was adjusted to 2 mm. The maximum surface stress is determined by the following equation.
Maximum surface stress (MPa) = 1.5 Etδ ₀ / L _s ²
However,
E: Young's modulus (MPa)
t: sample thickness (t = 0.25 mm)
δ ₀ : Initial deflection displacement (2 mm)
L _s : Span length (mm)
It is.
Residual stress rate was measured from the bending habit after holding for 1000 hours at a temperature of 150 ° C., and the stress relaxation resistance was evaluated. The residual stress rate was calculated using the following formula.
Residual stress rate (%) = (1−δ _t / δ ₀ ) × 100
However,
δ _t : Permanent deflection displacement after holding for 1000 h at 150 ° C. (mm) −Permanent deflection displacement after holding for 24 h at room temperature (mm)
δ ₀ : Initial deflection displacement (mm)
It is.

In Comparative Example 1, the Mg content was less than the range of the present invention, the 0.2% proof stress was low, and the strength was insufficient.
In Comparative Example 2, the Mg content was greater than the range of the present invention, and the electrical conductivity decreased.
In Comparative Example 3, the Mg content was larger than the range of the present invention, and [Mg] / [P] was more than 400, and a very deep skin roughness occurred. Therefore, the subsequent evaluation was stopped.
Since the comparative example 4 had more P content than the range of this invention, and the big ear crack generate | occur | produced at the time of rough rolling, subsequent evaluation was stopped.
In Comparative Examples 5 to 7, [Mg] + 20 × [P] exceeded 0.5, and a large ear crack was generated during rough rolling, so the subsequent evaluation was stopped.

On the other hand, in the example of the present invention, it is confirmed that 0.2% proof stress, electrical conductivity, stress relaxation resistance, bending workability, and castability are excellent.
From the above, according to the example of the present invention, the copper alloy for electronic / electric equipment and the copper alloy plastic working material for electronic / electric equipment excellent in conductivity, strength, bending workability, stress relaxation resistance and castability are obtained. It was confirmed that it could be provided.

Claims (9)

Mg is contained in the range of 0.15 mass% or more and less than 0.35 mass%, P is contained in the range of 0.0005 mass% or more and less than 0.01 mass%, and the balance consists of Cu and inevitable impurities,
Mg content [Mg] and P content [P] are in mass ratio,
[Mg] + 20 × [P] <0.5
And a copper alloy for electronic and electrical equipment, wherein the electrical conductivity exceeds 75% IACS. Mg content [Mg] and P content [P] are in mass ratio,
[Mg] / [P] ≦ 400
The copper alloy for electronic / electric equipment according to claim 1, wherein:   The copper alloy for electronic / electric equipment according to claim 1 or 2, wherein a 0.2% yield strength when a tensile test is performed in a direction orthogonal to the rolling direction is 300 MPa or more.   4. The copper alloy for electronic and electrical equipment according to claim 1, wherein the residual stress ratio is 50% or more at 1000 ° C. at 150 ° C. 5.   A copper alloy plastic working material for electronic / electric equipment comprising the copper alloy for electronic / electric equipment according to any one of claims 1 to 4.   6. The copper alloy plastic working material for electronic / electric equipment according to claim 5, wherein the surface has an Sn plating layer or an Ag plating layer.   An electronic / electric equipment part comprising the copper alloy plastic working material for electronic / electric equipment according to claim 5.   A terminal comprising the copper alloy plastic working material for an electronic / electrical device according to claim 5 or 6.   A bus bar comprising the copper alloy plastic working material for electronic / electric equipment according to claim 5.

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