JP6680042B2 - Copper alloys for electronic / electrical devices, plastic alloys for electronic / electrical devices, parts for electronic / electrical devices, terminals, and bus bars - Google Patents

Description

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

2. Description of the Related Art Conventionally, copper or copper alloy having high conductivity has been used for electronic and electric equipment parts such as terminals such as connectors and press fits, relays, lead frames, bus bars and the like.
Here, along with the miniaturization of electronic devices and electric devices, the parts for electronic and electric devices used in these electronic devices and electric devices have been made smaller and thinner. For this reason, high strength and good bending workability are required for materials constituting electronic / electrical device parts.

  Here, for example, Patent Documents 1 and 2 propose a Cu—Mg-based alloy as a material used for parts for electronic / electrical devices such as terminals such as connectors and press fits, relays, lead frames, and bus bars. There is.

JP, 2014-025089, A JP, 2014-114464, A

Here, in the Cu-Mg-based alloy described in Patent Document 1, since the content of Mg is large, the electrical conductivity is insufficient, and it is difficult to apply it to the application requiring high electrical conductivity. there were.
In addition, in the Cu-Mg-based 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%. Therefore, coarse crystallized substances were generated, and cold workability and bendability were insufficient.

  The present invention has been made in view of the above-described circumstances, and is a copper alloy for electronic / electrical devices, a copper alloy plastic-worked material for electronic / electrical devices, which has excellent conductivity, strength, and bendability, and electronic / electrical properties. An object is to provide a device part, a terminal, and a bus bar.

In order to solve this problem, the copper alloy for electronic / electrical devices of the present invention contains Mg in a range of 0.15 mass% or more and less than 0.35 mass%, the balance being Cu and unavoidable impurities, and being conductive. Except for the measurement point where the rate exceeds 75% IACS, the measurement area of 1000 μm ² or more is measured by the EBSD method at the measurement interval of 0.5 μm, and the CI value analyzed by the data analysis software OIM is 0.1 or less. The average value of KAM (Kernel Average Misorientation) values is 3.0 or less when the boundary where the orientation difference between adjacent pixels is 5 ° or more is regarded as a crystal grain boundary.

According to the copper alloy for electronic / electrical devices having the above-described configuration, the Mg content is set to be in the range of 0.15 mass% or more and less than 0.35 mass%, so that Mg forms a solid solution in the mother phase of copper. As a result, the strength and stress relaxation resistance can be improved without significantly reducing the conductivity. Specifically, since the electric conductivity is set to exceed 75% IACS, it can be applied to an application requiring high electric conductivity.
Further, according to the copper alloy for electronic / electrical equipment of the present invention, a region where the KAM value measured by EBSD is high is a region where the density of dislocations (GN dislocations) introduced during processing is high. When the value becomes higher, the processed structure substantially remains. Therefore, by setting the average value of the KAM value in the structure to 3.0 or less, it becomes possible to reduce the processed structure having a high dislocation density and a low elongation due to bending, which results in excellent bending workability. Become.

Here, in the copper alloy for an electrical and electronic equipment of the present invention, viewed including within the P less 0.0005 mass% or more 0.01 mass%, the Mg content [Mg] (mass%) and containing a P It is preferable that the amount [P] (mass%) satisfies the relational expression of [Mg] + 20 × [P] <0.5.
In this case, the addition of P can reduce the viscosity of the copper alloy molten metal containing Mg and improve the castability.
Further, it is possible to suppress the formation of coarse crystallized substances containing Mg and P, and it is possible to suppress deterioration of cold workability and bending workability.

Furthermore, when P is contained in the above range in the copper alloy for electronic / electrical devices of the present invention, the Mg content [Mg] (mass%) and the P content [P] (mass%) are It is preferable to satisfy the relational expression [Mg] / [P] ≦ 400.
In this case, the castability can be reliably improved by defining the ratio of the content of Mg that lowers the castability and the content of P that improves the castability as described above.

In addition, in the copper alloy for electronic / electrical equipment of the present invention, the CI value analyzed by the data analysis software OIM is 0.1 by measuring the measurement area of 1000 μm ² or more by the EBSD method at the measurement interval of 0.5 μm. It is preferable that the ratio of the following areas is 40% or less.
In this case, since the ratio of the area in which the CI value is 0.1 or less in which the work structure is greatly developed is 40% or less, it is possible to prevent the bending workability from being significantly deteriorated.

Furthermore, in the copper alloy for electronic / electrical devices of the present invention, it is preferable that the 0.2% proof stress when the tensile test is performed in the direction orthogonal to the rolling direction is 300 MPa or more.
In this case, since the 0.2% proof stress when a tensile test is performed in the direction orthogonal to the rolling direction is defined as described above, it is not easily deformed and a terminal such as a connector or press fit, It is especially suitable as a copper alloy for electronic and electrical equipment parts such as relays, lead frames and bus bars.

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

Here, in the copper alloy plastically worked material for electronic / electrical equipment of the present invention, it is preferable to have a Sn plating layer or an Ag plating layer on the surface.
In this case, since it has an Sn plating layer or an Ag plating layer on the surface, it is particularly suitable as a material for terminals for connectors, press-fitting, etc., parts for electronic / electrical devices such as relays, lead frames, bus bars and the like. In addition, in this invention, "Sn plating" includes pure Sn plating or Sn alloy plating, and "Ag plating" includes pure Ag plating or Ag alloy plating.

A component for electronic / electrical equipment of the present invention is characterized by comprising the above-described copper alloy plastically worked material for electronic / electrical equipment. The electronic / electrical device parts in the present invention include terminals such as connectors and press fits, relays, lead frames, bus bars and the like.
Since the electronic / electrical device component of this configuration is manufactured using the above-mentioned copper alloy plastically worked material for electronic / electrical device, it should exhibit excellent characteristics even when it is made smaller and thinner. You can

A terminal of the present invention is characterized by being made of the above-mentioned copper alloy plastically worked material for electronic / electrical devices.
Since the terminal having this configuration is manufactured using the above-described copper alloy plastically worked material for electronic / electrical devices, it is possible to exhibit excellent characteristics even when the terminal is downsized and thinned.

A bus bar of the present invention is characterized by being made of the above-described copper alloy plastically worked material for electronic / electrical devices.
Since the bus bar having this structure is manufactured using the above-described copper alloy plastic-worked material for electronic / electrical devices, it can exhibit excellent characteristics even when it is downsized and thinned.

  ADVANTAGE OF THE INVENTION According to this invention, the copper alloy for electronic / electrical devices excellent in electroconductivity, strength, and bending workability, the copper alloy plasticity processing material for electronic / electrical devices, the components for electronic / electrical devices, a terminal, and a bus bar are provided. can do.

It is a flow figure of a manufacturing method of a copper alloy for electronic and electric equipment which is this embodiment.

Below, the copper alloy for electronic and electric equipment which is one embodiment of the present invention is explained.
The copper alloy for electronic / electrical devices according to the present embodiment has a composition containing Mg in the range of 0.15 mass% or more and less than 0.35 mass%, and the balance Cu and unavoidable impurities.
In addition, in the copper alloy for electronic / electrical devices of the present embodiment, the electrical conductivity is set to exceed 75% IACS.
Further, in the copper alloy for electronic / electrical equipment of the present embodiment, the measurement area of 1000 μm ² or more is measured by the EBSD method at the measurement interval of 0.5 μm, and the CI value analyzed by the data analysis software OIM is 0. The average value of the KAM (Kernel Average Misorientation) value is 3.0 or less when the boundary where the orientation difference between adjacent pixels is 5 ° or more is regarded as a crystal grain boundary, except for measurement points that are 1 or less. ing.

The copper alloy for electronic / electrical devices according to the present embodiment may further contain P in a range of 0.0005 mass% or more and less than 0.01 mass%.
When P is contained in the above-mentioned range in the copper alloy for electronic / electrical equipment of the present embodiment, the content [Mg] (Mg%) of Mg and the content [P] (Mass%) of P are
[Mg] + 20 × [P] <0.5
The relational expression of is satisfied.
Further, in the present embodiment, the Mg content [Mg] (mass%) and the P content [P] (mass%) are
[Mg] / [P] ≦ 400
The relational expression of is satisfied.

Further, in the copper alloy for electronic / electrical equipment of the present embodiment, the measurement area of 1000 μm ² or more was measured by the EBSD method at the measurement interval of 0.5 μm, and the CI value analyzed by the data analysis software OIM was 0. The ratio of the area that is less than or equal to 1 is 40% or less.
Furthermore, in the copper alloy for electronic / electrical devices of the present embodiment, the 0.2% proof stress when the tensile test is performed in the direction orthogonal to the rolling direction is set to 300 MPa or more.

  Here, the reasons for defining the component composition, crystal orientation, and various characteristics as described above will be described below.

(Mg: 0.15 mass% or more and less than 0.35 mass%)
Mg is an element that has a function of improving strength and stress relaxation resistance characteristics by not forming a large decrease in conductivity by forming a solid solution in the mother phase of a copper alloy.
Here, when the content of Mg is less than 0.15 mass%, there is a possibility that the action and effect cannot be sufficiently exerted. On the other hand, when the content of Mg is 0.35 mass% or more, the conductivity is significantly reduced, the viscosity of the molten copper alloy is increased, and the castability may be reduced.
From the above, in the present embodiment, the Mg content is set within the range of 0.15 mass% or more and less than 0.35 mass%.
In addition, in order to further improve the strength and the stress relaxation resistance, the lower limit of the Mg content is preferably 0.18 mass% or more, and more preferably 0.2 mass% or more. Further, in order to reliably suppress the decrease in conductivity and the decrease in castability, the upper limit of the Mg content is preferably 0.32 mass% or less, and more preferably 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. Further, by forming a compound with Mg, it also has the function of reducing the recrystallized grain size.
Here, when the content of P is less than 0.0005 mass%, there is a possibility that the action and effect cannot be sufficiently exerted. On the other hand, when the P content is 0.01 mass% or more, the above-mentioned crystallized product containing Mg and P is coarsened, and this crystallized substance becomes a starting point of fracture, and during cold working or Cracks may occur during bending.
From the above, when P is added in the present embodiment, the content of P is preferably in the range of 0.0005 mass% or more and less than 0.01 mass%. In order to reliably improve the castability, the lower limit of the P content is preferably 0.0007 mass% or more, and more preferably 0.001 mass% or more. Further, in order to reliably suppress the formation of coarse crystallized substances, the upper limit of the P content is preferably less than 0.009 mass%, more preferably less than 0.008 mass%, and even more preferably 0. Most preferably, it is 0075 mass% or less.

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

([Mg] / [P] ≦ 400)
Since Mg is an element that increases the viscosity of the molten copper alloy and reduces the castability, it is necessary to optimize the content ratio of Mg and P in order to reliably improve the castability. There is.
Here, when the content of Mg is [Mg] and the content of P is [P] in mass%, and [Mg] / [P] exceeds 400, the ratio of Mg to P is There is a possibility that the content is increased and the effect of improving the castability by adding P is reduced.
From the above, when P is added 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, more preferably 300 or less.
When [Mg] / [P] is excessively low, Mg is consumed as a crystallized substance, and the effect due to solid solution of Mg may not be obtained. In order to suppress the formation of crystallized substances containing Mg and P and to surely improve the yield strength and stress relaxation resistance due to the solid solution of Mg, the lower limit of [Mg] / [P] is set to more than 20. Preferably, it is more preferably 25 or more.

(Inevitable impurities: 0.1 mass% or less)
Other unavoidable impurities include Ag, B, Ca, Sr, Ba, Sc, Y, rare earth elements, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe and 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. These unavoidable impurities have the effect of lowering the conductivity, so the total amount is made 0.1 mass% or less.
Further, Ag, Zn, and Sn are easily mixed in copper to reduce the conductivity, so that the total amount is preferably less than 500 mass ppm.
Furthermore, Si, Cr, Ti, Zr, Fe, and Co particularly greatly reduce conductivity and deteriorate bending workability due to the formation of inclusions. Therefore, the total amount of these elements is preferably less than 500 mass ppm. .

(KAM (Kernel Average Misorientation) value)
The KAM (Kernel Average Misorientation) value measured by EBSD is a value calculated by averaging the azimuth difference between one pixel and pixels surrounding it. Since the shape of a pixel is a regular hexagon, when the proximity order is set to 1 (1st), the average value of the orientation difference between six adjacent pixels is calculated as a KAM value. By using this KAM value, the local orientation difference, that is, the strain distribution can be visualized. Since the region with a high KAM value is a region with a high density of dislocations (GN dislocations) introduced at the time of processing, by controlling the average value of this KAM value to 3.0 or less, the yield strength is maintained, Further, bending workability can be improved. The KAM average value is preferably 2.8 or less, and more preferably 2.6 or less even within the above range. On the other hand, if the average KAM value is too low, the amount of work hardening may be small and sufficient strength may not be ensured. Therefore, the average KAM value is preferably 1.0 or more, and 1.5 or more. It is more preferable that there is.
In the present invention, the KAM value is calculated with the proximity order being 1.
Further, in the present invention, an average value of KAM values in a structure excluding a region having a CI value of 0.1 or less, which will be described later, in which a processed structure is remarkably developed and a clear crystal pattern is not obtained, is obtained.

(CI (Confidence Index) value)
A measurement point with a CI value of 0.1 or less is a state in which the strain introduced during processing is particularly large and the processed structure is greatly developed, which greatly deteriorates bendability. Therefore, it is preferable that the proportion of measurement points having a CI value of 0.1 or less is 40% or less. It is more preferably 35% or less, still more preferably 30% or less.
The CI value is a value measured by the analysis software OIM Analysis (Ver.6.2) of the EBSD device, and the Voting method should be used when indexing the EBSD pattern obtained from a certain analysis point. And takes a value from 0 to 1. Since the CI value is a value that evaluates the reliability of indexing and orientation calculation, when the CI value is low, that is, when a crystal pattern with a clear analysis point cannot be obtained, strain (working structure) exists in the structure. It can be said that they are doing. When the strain is particularly large, the CI value is 0.1 or less. Therefore, when the ratio of the measurement points having a CI value of 0.1 or less is 40% or less, the structure having a relatively small strain is maintained and bending workability is ensured.

(Conductivity: over 75% IACS)
In the copper alloy for electronic / electrical equipment of the present embodiment, by setting the electrical conductivity to exceed 75% IACS, it can be used as a component for electronic / electrical equipment such as terminals such as connectors and press fits, relays, lead frames, and bus bars. It can be used well.
The electrical conductivity is preferably 76% IACS or more, more preferably 77% IACS or more, further preferably 78% IACS or more, and further preferably 80% IACS or more.

(0.2% proof stress: 300 MPa or more)
In the copper alloy for electronic / electrical devices according to the present embodiment, the 0.2% proof stress is set to 300 MPa or more, so that terminals such as connectors and press fits, electronic / electrical device parts such as relays, lead frames, and busbars It is particularly suitable as a material for. In this 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.
Here, the above-mentioned 0.2% proof stress is preferably 325 MPa or more, and more preferably 350 MPa or more.

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

(Melting / casting process S01)
First, the above-mentioned elements are added to a molten copper obtained by melting a copper raw material to adjust the components, and a molten copper alloy is produced. Here, the copper melt 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. It should be noted that a simple element, a mother alloy, or the like can be used to add various elements. Moreover, you may melt | dissolve the raw material containing the above-mentioned element with a copper raw material. Also, recycled materials and scrap materials of the present alloy may be used. In the melting process, in order to suppress the oxidation of Mg and to reduce the hydrogen concentration, the atmosphere is melted in an inert gas atmosphere (for example, Ar gas) with a low vapor pressure of H ₂ O, and the holding time during melting is minimized. It is preferable to keep

Then, the molten copper alloy having the adjusted components is poured into a mold to produce an ingot. In consideration of mass production, it is preferable to use the continuous casting method or the semi-continuous casting method.
At this time, since a crystallized substance containing Mg and P is formed during solidification of the molten metal, the crystallized substance size can be made 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 treatment step S02)
Next, heat treatment is performed for homogenization and solution treatment of the obtained ingot. Inside the ingot, there may be an intermetallic compound containing Cu and Mg as main components, which are generated by the segregation and concentration of Mg during the solidification process. Therefore, in order to eliminate or reduce such segregation and intermetallic compounds, a heat treatment of heating the ingot to 300 ° C. or more and 900 ° C. or less is performed to uniformly diffuse Mg in the ingot. , Mg may be dissolved in the mother phase. The homogenization / solution treatment step S02 is preferably performed in a non-oxidizing or reducing atmosphere.

  Here, if the heating temperature is less than 300 ° C., solution treatment may be incomplete, and a large amount of intermetallic compounds containing Cu and Mg as main components may remain in the mother phase. On the other hand, if the heating temperature exceeds 900 ° C., a part of the copper material may be in a liquid phase, and the texture and surface condition may be non-uniform. Therefore, the heating temperature is set in the range of 300 ° C to 900 ° C.

(Hot working step S03)
Hot working is performed to improve the efficiency of roughing and to homogenize the structure. The temperature condition in this hot working step S03 is not particularly limited, but it is preferably in the range of 400 ° C to 900 ° C. Further, as a cooling method after processing, it is preferable to cool to 200 ° C. or less at a cooling rate of 60 ° C./min or more such as water quenching. Further, the processing method is not particularly limited, and for example, rolling, wire drawing, extrusion, groove rolling, forging, pressing and the like can be adopted.

(Roughing process S04)
Roughing is performed to form a predetermined shape. The temperature condition in this rough working step S04 is not particularly limited, but in order to suppress recrystallization or to improve dimensional accuracy, it is cold or warm rolling within a range of -200 ° C to 200 ° C. Is preferable, and room temperature is particularly preferable. The processing rate (rolling rate) is preferably 20% or more, more preferably 30% or more. The processing method is not particularly limited, and for example, rolling, wire drawing, extrusion, groove rolling, forging, pressing and the like can be adopted.

(Intermediate heat treatment step S05)
After the roughing process S04, 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. or more and 900 ° C. or less and a holding time of 10 seconds or more and 10 hours or less. When the crystal grains are excessively fine, specifically, when the crystal grain size is 3 μm or less, the KAM value tends to increase. Therefore, the heat treatment temperature is particularly preferably 500 ° C. or higher and 900 ° C. or lower. Further, the cooling method after heating is not particularly limited, but it is preferable to adopt a method such as water quenching that provides a cooling rate of 200 ° C./min or more.
In addition, when the crystal grain size is uniform, local concentration of the high strain portion (the point where the KAM value is high and the CI value is low) is hard to occur, so the roughing step S04 and the intermediate heat treatment step S05 are performed twice. It is preferable to repeat the above.

(Finishing process S06)
Finishing is performed to process the copper material after the intermediate heat treatment step S05 into a predetermined shape. The temperature condition in this finishing step S06 is not particularly limited, but is within a range of -200 ° C to 200 ° C, which is cold or warm working in order to suppress recrystallization or softening. Is preferable, and room temperature is particularly preferable. 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 step S06, the processing rate is preferably 20% or more. Also. When further improving the strength, the working rate is more preferably 30% or more, and further preferably 40% or more.
On the other hand, in order to suppress an excessive increase in the region where the KAM value and the CI value are below 0.1, the working rate is preferably 90% or less, and more preferably 85% or less.

(Finishing heat treatment step S07)
Next, the plastically worked material obtained in the finishing step S06 is subjected to finishing heat treatment for improving the stress relaxation resistance and low temperature annealing hardening, or for removing residual strain.
When the heat treatment temperature is too low, the region where the CI value is less than 0.1 and the KAM value are excessively increased. Therefore, the heat treatment temperature is preferably in the range of 100 ° C. or higher and 800 ° C. or lower, and 200 ° C. or higher and 700 ° C. It is more preferable to set it within the following range. In this finishing heat treatment step S07, it is necessary to set the heat treatment conditions (temperature, time, cooling rate) so as to avoid a significant decrease in strength due to recrystallization.
For example, at 300 ° C., it is preferable to hold for 1 second 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 in a continuous annealing furnace is preferable from the effect of reducing manufacturing cost.
Further, the finishing step S06 and the finishing heat treatment step S07 may be repeatedly performed.

  In this way, a rolled plate (thin plate) is produced as the copper alloy plastically worked material for electronic / electrical equipment according to the present embodiment. The thickness of the copper alloy plastically worked material (thin plate) for electronic / electrical devices is in the range of more than 0.05 mm and less than 3.0 mm, preferably in the range of more than 0.1 mm and less than 3.0 mm. It is said that. If the thickness of the copper alloy plastically worked material (thin plate) for electronic / electrical equipment is 0.05 mm or less, it is unsuitable for use as a conductor for large current applications, and if the thickness exceeds 3.0 mm. However, press punching becomes difficult.

Here, the copper alloy plastically worked material for electronic / electrical equipment according to the present embodiment may be used as it is for a component for electronic / electrical equipment. You may form a Sn plating layer or Ag plating layer of about 100 micrometers. At this time, the plate thickness of the copper alloy plastically worked material for electronic / electrical devices is preferably 10 to 1000 times the plating layer thickness.
Further, by using a copper alloy for electronic / electrical equipment (copper alloy plastic working material for electronic / electrical equipment) of the present embodiment as a material, punching or bending is performed, for example, a terminal such as a connector or press fit, Parts for electronic and electrical equipment such as relays, lead frames and bus bars are molded.

According to the copper alloy for an electronic / electrical device of the present embodiment configured as described above, since the content of Mg is within the range of 0.15 mass% or more and less than 0.35 mass%, Since Mg forms a solid solution in the matrix, it becomes possible to improve the strength and the stress relaxation resistance without significantly reducing the conductivity.
Further, in the copper alloy for electronic / electrical equipment according to the present embodiment, since the electrical conductivity is set to 75% IACS or more, the copper alloy for electronic / electrical devices can be applied to applications requiring high electrical conductivity.

In the copper alloy for electronic / electrical equipment of the present embodiment, the measurement area of 1000 μm ² or more is measured by the EBSD method at the measurement interval of 0.5 μm, and the CI value analyzed by the data analysis software OIM is 0. Since the average value of KAM values is 3.0 or less when the boundary where the orientation difference between adjacent pixels is 5 ° or more is regarded as a crystal grain boundary, except for measurement points that are 1 or less. There are few regions where the density of dislocations (GN dislocations) introduced during processing is high, and bending workability is excellent.

In addition, when P is added to the copper alloy for electronic / electrical equipment according to the present embodiment and the content of P is within the range of 0.0005 mass% or more and less than 0.01 mass%, the viscosity of the molten copper alloy is It is possible to reduce the castability and improve the castability.
Since the Mg content [Mg] (mass%) and the P content [P] (mass%) satisfy the relational expression of [Mg] + 20 × [P] <0.5, Mg It is possible to suppress the formation of coarse crystallized substances of P and P, and to suppress the deterioration of cold workability and bendability.
Further, in the present embodiment, the Mg content [Mg] (mass%) and the P content [P] (mass%) satisfy the relational expression [Mg] / [P] ≦ 400. The ratio of the content of Mg that lowers the castability and the content of P that improves the castability is optimized, and the effect of adding P can surely improve the castability.

In the present embodiment, the measurement area of 1000 μm ² or more is measured by the EBSD method at the measurement interval of 0.5 μm, and the ratio of the area having the CI value analyzed by the data analysis software OIM of 0.1 or less is 40. %, It is possible to have a high bending workability, and there is little structure in which the work structure is greatly developed.

Further, since the copper alloy plastically worked material for electronic / electrical equipment according to the present embodiment is made of the above-mentioned copper alloy for electronic / electrical equipment, it is possible to bend the copper alloy plastically worked material for electronic / electrical equipment into a bent material. By doing so, it is possible to manufacture terminals for connectors, press fits, etc., parts for electronic / electrical devices such as relays, lead frames, bus bars and the like.
In addition, when the Sn plating layer or the Ag plating layer is formed on the surface, it is particularly suitable as a material for terminals for connectors, press-fitting, etc., parts for electronic / electrical devices such as relays, lead frames, bus bars and the like.

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

The copper alloy for electronic / electrical devices, the copper alloy plastic-worked material for electronic / electrical devices, and the parts for electronic / electrical devices (terminals, bus bars, etc.), which are the embodiments of the present invention, have been described above. The present invention is not limited, and can be appropriately changed 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 / electrical equipment has been described, but the method for producing a copper alloy for electronic / electrical equipment is not limited to the one described in the embodiment. Alternatively, an existing manufacturing method may be appropriately selected and manufactured.

Below, the result of the confirmation experiment conducted in order to confirm the effect of the present invention will be described.
A copper raw material made of oxygen-free copper (ASTM B152 C10100) with a purity of 99.99 mass% or more was prepared, charged into a high-purity graphite crucible, and subjected to high frequency melting in an atmosphere furnace in an Ar gas atmosphere. Various additive elements were added to the obtained molten copper to prepare the component composition shown in Table 1, and the molten copper was poured into a mold to produce an ingot. Inventive Example 4 is a heat insulating material (isowool) mold, Inventive Example 24 is a carbon mold, Inventive Examples 1 to 3, 5 to 23, 25 to 33, and Comparative Examples 1 to 5 are copper alloys having a water cooling function. The mold was used as a casting mold. The size of the ingot was about 100 mm in thickness × about 150 mm in width × about 70 mm in length.
The vicinity of the casting surface of this ingot was chamfered, and the ingot was cut out and the size was adjusted so that the plate thickness of the final product was 0.5 mm.
This block was heated and held under the temperature conditions shown in Table 2 for 4 hours in an Ar gas atmosphere. Then, the block after heating and holding was subjected to hot rolling under the conditions shown in Table 2 and water quenching.

Then, after performing the first rough rolling under the conditions shown in Table 2, the first intermediate heat treatment was performed under the conditions shown in Table 2. Further, the second rough rolling and the second intermediate heat treatment were performed under the conditions shown in Table 2.
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. Then, at room temperature, finish rolling (finishing) was carried out at a rolling rate shown 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 prepare a thin plate for property evaluation.

(Castability)
As an evaluation of the castability, the presence or absence of rough skin during the above-mentioned casting was observed. The case where no or almost no rough skin was visually observed was rated as ⊚, the case where a small rough surface having a depth of less than 1 mm occurred was rated as ○, and the rough surface having a depth of 1 mm or more and less than 2 mm was rated as Δ. In addition, the case where a large skin roughness with a depth of 2 mm or more occurred was marked with x and the evaluation was stopped halfway. The evaluation results are shown in Table 3.
The rough skin depth is the depth of rough skin from the end portion to the central portion of the ingot.

(Mechanical properties)
A No. 13B test piece specified in JIS Z 2241 was sampled from the characteristic evaluation strip, and 0.2% proof stress was measured by the offset method of JIS Z 2241. The test pieces were taken in a direction orthogonal 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 sampled from the characteristic evaluation strip, and the electrical resistance was determined by the 4-terminal method. The dimension of the test piece was measured using a micrometer, and the volume of the test piece was calculated. Then, the conductivity was calculated from the measured electric resistance value and the volume. The test piece was sampled so that its longitudinal direction was perpendicular to the rolling direction of the characteristic evaluation strip. The evaluation results are shown in Table 3.

(Bending workability)
Bending was performed according to the 4 test methods of Japan Copper and Brass Association technical standard JCBA-T307: 2007. A plurality of test pieces with a width of 10 mm and a length of 30 mm were sampled from the thin plate for characteristic evaluation so that the axis of bending was orthogonal to the rolling direction, and the bending angle was 90 degrees and the bending radius was 0.3 mm (R / A W-bending test was performed using a W-type jig with t = 0.6).
When cracks are observed visually by observing the outer periphery of the bent portion, `` X '' is judged, when large wrinkles are observed, it is judged as ◯, and when fracture or fine cracks or large wrinkles cannot be confirmed, judgment is made as ◎. It was It should be noted that ⊚ and ○ were judged to be acceptable bending workability. The evaluation results are shown in Table 3.

(KAM value, CI value)
With the plane perpendicular to the rolling width direction, that is, the TD plane (Transverse direction) as the observation plane, the EBSD measuring device and the OIM analysis software are used to determine the crystal grain boundaries (special grain boundaries and random grain boundaries) and the crystal grains as follows. The misorientation distribution was measured.
After mechanical polishing was performed using water-resistant polishing paper and diamond abrasive grains, final polishing was performed using a colloidal silica solution. Then, an EBSD measuring apparatus (Quanta FEG 450 manufactured by FEI, OIM Data Collection manufactured by EDAX / TSL (current AMETEK) and analysis software (manufactured by EDAX / TSL (current AMETEK) OIM Data Analysis ver. 6.2). ), The CI value was determined in the measurement area of 1000 μm ² or more at the electron beam acceleration voltage of 20 kV and the measurement interval of 0.5 μm step, and the ratio of the area having the CI value of 0.1 or less was determined.
Further, after that, the misorientation of each crystal grain is analyzed except for the measurement points where the CI value is 0.1 or less, and the boundary where the misorientation between adjacent pixels is 5 ° or more is regarded as a crystal grain boundary. The KAM value of all analyzed pixels was calculated, and the average value thereof was calculated.

In Comparative Examples 1 and 2, the Mg content was less than the range of the present invention, and the yield strength was insufficient.
In Comparative Examples 3 and 4, the content of Mg was larger than the range of the present invention, and the conductivity was low.
In Comparative Example 5, the KAM value was higher than the range of the present invention, and bending workability was insufficient.

On the other hand, it is confirmed that the example of the present invention is excellent in strength, conductivity and bending workability. It is also confirmed that when P is added, the castability is excellent.
From the above, according to the present invention example, it was confirmed that a copper alloy for electronic / electrical devices and a copper alloy plastically worked material for electronic / electrical devices which were excellent in strength, conductivity and bending workability could be provided.

Claims (10)

Mg in the range of 0.15 mass% or more and less than 0.35 mass%, the balance consisting of Cu and inevitable impurities,
With conductivity exceeding 75% IACS,
The azimuth difference between adjacent pixels is measured by the EBSD method by measuring a measurement area of 1000 μm ² or more at a measurement interval of 0.5 μm, and except for a measurement point whose CI value analyzed by the data analysis software OIM is 0.1 or less. A copper alloy for electronic / electrical devices, wherein an average KAM (Kernel Average Misorientation) value is 3.0 or less when a boundary having an angle of 5 ° or more is regarded as a crystal grain boundary. Look including the P in the range of less than 0.0005 mass% or more 0.01 mass%, the Mg content [Mg] (mass%) and the content of P (P) (mass%) is,
[Mg] + 20 × [P] <0.5
The copper alloy for electronic / electrical devices according to claim 1, which satisfies the following relational expression . The content of Mg [Mg] (mass%) and the content of P [P] (mass%) are
[Mg] / [P] ≦ 400
The copper alloy for electronic / electrical devices according to claim 2, which satisfies the relational expression of. Characteristic that the ratio of the area where the CI value analyzed by the data analysis software OIM is 0.1 or less is 40% or less by measuring the measurement area of 1000 μm ² or more by the EBSD method at the measurement interval of 0.5 μm step. The copper alloy for electronic / electrical devices according to any one of claims 1 to 3 . The 0.2% proof stress when a tensile test is performed in a direction orthogonal to the rolling direction is 300 MPa or more, for electronic / electrical devices according to any one of claims 1 to 4 . Copper alloy. A copper alloy plastic-worked material for electronic / electrical devices, comprising the copper alloy for electronic / electrical devices according to any one of claims 1 to 5 . The copper alloy plastic working material for electronic / electrical equipment according to claim 6, which has a Sn plating layer or an Ag plating layer on the surface. A component for electronic / electrical equipment, comprising the copper alloy plastically worked material for electronic / electrical equipment according to claim 6 or 7 . A terminal comprising the copper alloy plastically worked material for electronic / electrical devices according to claim 6 or 7 . A bus bar comprising the copper alloy plastically worked material for electronic / electrical devices according to claim 6 or 7 .

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