JP2015014020A - Copper alloy for electronic and electrical apparatus, copper alloy thin sheet for electronic and electrical apparatus, and part and terminal for electronic and electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy for electronic and electrical apparatuses which has excellent proof strength-flexure balance, is especially excellent in stress relaxation resistance characteristics, and is suitable for parts for electronic and electrical apparatuses, including terminals of e.g. connectors, relays, and lead frames.SOLUTION: A copper alloy for electronic and electrical apparatuses contains 1.0-5.0 mass% of Ni, 0.1-1.5 mass% of Si and the remaining mass being Cu and unavoidable impurities, and has a composition where a Ni/Si mass ratio falls in a range of 2.0-6.0. A special particle boundary length ratio, (Lσ/L), or a ratio of the sum Lσ of individual particle boundary lengths of Σ3, Σ9, Σ27a and Σ27b to all the crystal particle boundary lengths, is 30% or higher, and a ratio R{200} of X-ray diffraction intensity from a {200} plane on a surface of a material is 0.2 or higher.

Description

  The present invention relates to a copper alloy for electronic / electric equipment used as a terminal for a connector of a semiconductor device, a movable conductive piece of an electromagnetic relay, or a component for electronic / electric equipment such as a lead frame, and an electronic / electronic device using the same. The present invention relates to copper alloy thin plates for electrical equipment, parts for electronic and electrical equipment, and terminals.

  Conventionally, along with downsizing of electronic equipment and electrical equipment, etc., miniaturization and thinning of electronic and electrical equipment parts such as connectors, relays, lead frames and other terminals used in such electronic equipment and electrical equipment are being attempted. It has been. For this reason, a copper alloy excellent in springiness, strength, and bending workability is required as a material constituting electronic / electric equipment parts. In particular, as described in Non-Patent Document 1, a copper alloy having high proof strength is desirable as a copper alloy used as a component for electronic and electrical equipment such as a terminal such as a connector, a relay, and a lead frame.

Here, as a copper alloy used as components for electronic and electrical equipment such as terminals, connectors, relays, and lead frames, for example, Patent Document 1-3 provides a Cu—Ni—Si based alloy (so-called Corson alloy). Has been. This Corson alloy is a precipitation hardening type alloy in which precipitates made of Ni ₂ Si are dispersed, and has a relatively high conductivity and strength. For this reason, it is widely used as a terminal for automobiles and signal system small terminals, and has been actively developed in recent years.

For example, in the copper alloy for electronic / electric equipment described in Patent Document 2, the ratio R {200} of the diffraction intensity from the {200} plane on the material surface is set to 0.3 or more, so that the bending workability can be improved. We are trying to improve.
In addition, in the copper alloy for electronic and electrical equipment described in Patent Document 3, a special grain for the total grain boundary length of the grain boundary measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system. By defining the ratio of the total special grain boundary length of the boundary to 60 to 70%, the deep drawability and the fatigue resistance are improved.

Japanese Patent Laid-Open No. 11-036055 JP 2009-007666 A JP2012-122114A

Yukiya Nomura, “Technical Trends of High Performance Copper Alloy Strips for Connectors and Our Development Strategy”, Kobe Steel Technical Report Vol. 54No. 1 (2004) p. 2-8

  By the way, recently, with the further weight reduction of electronic / electrical equipment, the thickness of electronic / electrical equipment parts such as connectors, relays, lead frames and other terminals used in such electronic equipment and electrical equipment has been reduced. It has been. For this reason, in a terminal such as a connector, it is necessary to perform a strict bending process in order to ensure a contact pressure, and a proof stress-bending balance superior to the conventional one is required. Furthermore, these parts for electronic and electric devices are also applied to applications used in a high temperature environment such as an engine room of an automobile, and are required to have a stress relaxation resistance superior to conventional ones.

Here, in the copper alloy for electronic / electric equipment described in Patent Document 2, as described above, the bending workability is determined by defining the ratio R {200} of the diffraction intensity from the {200} plane on the material surface. However, there is a possibility that sufficient proof stress-bending balance cannot be obtained. In addition, the stress relaxation resistance is improved by adjusting the component composition. Therefore, when the amount of additive elements is reduced to ensure conductivity, the stress relaxation resistance becomes insufficient, and the stress relaxation resistance is reduced. There was a risk that it could not be used.
Moreover, in the copper alloy for electronic / electric equipment described in Patent Document 3, the ratio of the total special grain boundary length of the special grain boundary to the total grain boundary length of the crystal grain boundary is defined as 60 to 70%. However, since the crystal orientation is not taken into consideration, there is a possibility that sufficient bending workability and stress relaxation characteristics cannot be obtained.

  The present invention has been made against the background as described above, and has an excellent proof stress-bending balance, and is particularly excellent in stress relaxation resistance, such as terminals of connectors, relays, lead frames, etc. It is an object of the present invention to provide a copper alloy for electronic / electric equipment, a copper alloy thin plate for electronic / electric equipment, electronic / electric equipment parts and terminals suitable for electric equipment parts.

In order to solve this problem, the copper alloy for electronic and electrical equipment of the present invention contains Ni in an amount of 1.0 mass% to 5.0 mass%, Si in an amount of 0.1 mass% to 1.5 mass%, and the rest It consists of Cu and inevitable impurities and has a composition in which Ni / Si (mass ratio) is in the range of 2.0 or more and 6.0 or less, and a measurement area of 1000 μm ² or more by the EBSD method at a measurement interval of 0.1 μm step. Measured and analyzed with the exception of measurement points with a CI value of 0.1 or less analyzed by the data analysis software OIM, and a crystal grain boundary between the measurement points where the orientation difference between adjacent measurements exceeds 15 °, The special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b to all the grain boundary lengths L, is 30% or more, and the material surface {111} plane in X-ray diffraction intensity from I {111}, X-ray diffraction intensity from {200} plane from I {200}, X-ray diffraction intensity from {220} plane from I {220}, {311} plane X-ray diffraction intensity is I {311}, X-ray diffraction intensity from {331} plane is I {331}, X-ray diffraction intensity from {420} plane is I {420}, X-ray from {200} plane When the ratio R {200} of the diffraction intensity is R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}) , R {200} is 0.2 or more.

In the copper alloy for electronic and electrical equipment of the present invention having the above-described configuration, Ni is contained in an amount of 1.0 mass% to 5.0 mass%, Si is contained in an amount of 0.1 mass% to 1.5 mass%, and the remainder is Cu. And a precipitate composed of an intermetallic compound mainly composed of Ni ₂ Si since it has a composition in which Ni / Si (mass ratio) is in the range of 2.0 to 6.0. The particles can be dispersed in the copper matrix, and the strength can be improved while ensuring high electrical conductivity.

  And in the copper alloy for electronic / electrical equipment of the present invention having the above-mentioned configuration, the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b to all the crystal grain boundary lengths L. Since the special grain boundary length ratio (Lσ / L) is 30% or more and the ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface is 0.2 or more, Grain boundaries with high crystallinity (grain boundaries with less disorder of atomic arrangement) increase in the structure of the copper alloy oriented in the {200} plane.

Here, since the {200} plane has an azimuth relationship in which the sliding system is likely to be active with respect to the stress direction of bending, local deformation can be suppressed. Furthermore, an increase in grain boundaries with high crystallinity (grain boundaries with less disorder of atomic arrangement) reduces the proportion of grain boundaries that are the starting point of fracture during bending. In the copper alloy for electronic and electrical equipment of the present invention, the yield strength-bending balance is drastically improved by these synergistic effects. In addition, the special grain boundary can improve the stress relaxation resistance because the grain boundary diffuses slower than the random grain boundary.
In order to achieve the above-mentioned effects and effects, the special grain boundary length ratio (Lσ / L) is preferably 45% or more, and more preferably 50% or more. The ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface is preferably 0.25 or more, and more preferably 0.3 or more.

  Note that the EBSD method means an electron beam diffraction diffraction pattern (EBSD) method using a scanning electron microscope with a backscattered electron diffraction image system, and the OIM uses crystal data measured by the EBSD. This is data analysis software Orienting Imaging Microscopy (OIM) for analyzing the orientation. Further, the CI value is a reliability index, which is displayed as a numerical value representing the reliability of crystal orientation determination when analyzed using analysis software OIM Analysis (Ver. 5.3) of an EBSD device. (For example, “EBSD Reader: Using OIM (Revised 3rd Edition)” written by Seiichi Suzuki, September 2009, published by TSL Solutions, Inc.). Here, when the structure of the measurement point measured by EBSD and analyzed by OIM is a processed structure, since the crystal pattern is not clear, the reliability of crystal orientation determination is lowered, and the CI value is lowered. In particular, when the CI value is 0.1 or less, it is determined that the structure of the measurement point is a processed structure.

The special grain boundary is a Σ value defined crystallographically based on CSL theory (Kronberg et al: Trans. Met. Soc. AIME, 185, 501 (1949)) and corresponding to 3 ≦ Σ ≦ 29. The grain boundary and the inherent corresponding site lattice orientation defect Dq at the corresponding grain boundary is Dq ≦ 15 ° / Σ ^1/2 (DG Brandon: Acta. Metallurgica. Vol. 14, p. 1479, (1966)).
On the other hand, a random grain boundary is a grain boundary other than a special grain boundary that has a corresponding orientation relationship with a Σ value of 29 or less and satisfies Dq ≦ 15 ° / Σ ^1/2 .

In addition, the copper alloy for electronic and electrical equipment of the present invention contains 1.0 mass% or more of Ni, and contains one or more of Co, Mn, and Fe, and Ni, Co, Mn , Fe content is 1.0 mass% to 5.0 mass% or less, Si is contained 0.1 mass% or more and 1.5 mass% or less, the remainder is made of Cu and inevitable impurities, and (Ni + Co + Mn + Fe) / Si (Mass ratio) has a composition in the range of 2.0 or more and 6.0 or less, measures the measurement area of 1000μm ² or more by the EBSD method at the measurement interval of 0.1μm step, and analyzes it by the data analysis software OIM The analysis is performed except for the measurement points having a CI value of 0.1 or less, and the crystal grain boundary is defined as the crystal grain boundary between the measurement points where the orientation difference between adjacent measurements exceeds 15 °. The special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b, is 30% or more, and X from the {111} plane on the material surface X-ray diffraction intensity from I {111}, X-ray diffraction intensity from {200} plane is I {200}, X-ray diffraction intensity from {220} plane is I {220}, X-ray diffraction from {311} plane The intensity is I {311}, the X-ray diffraction intensity from the {331} plane is I {331}, the X-ray diffraction intensity from the {420} plane is I {420}, and the X-ray diffraction intensity from the {200} plane is When the ratio R {200} is R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}), R {200 } Is 0.2 or more.

In the copper alloy for electronic and electrical equipment of the present invention configured as described above, Ni is contained in an amount of 1.0 mass% or more, and contains any one or more of Co, Mn, Fe, The total content of Ni, Co, Mn, and Fe is 1.0 mass% and 5.0 mass% or less, Si is contained 0.1 mass% or more and 1.5 mass% or less, and the remainder consists of Cu and inevitable impurities, Since (Ni + Co + Mn + Fe) / Si (mass ratio) has a composition in the range of 2.0 or more and 6.0 or less, Co, Mn, and Fe substitute a part of Ni, and Ni ₂ Precipitate particles composed of an intermetallic compound mainly containing Si can be dispersed in a copper matrix, and strength can be improved while ensuring high electrical conductivity.
Further, the special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b to all the grain boundary lengths L, is set to 30% or more. Since the ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface is 0.2 or more, the yield strength-bending balance can be dramatically improved and excellent stress resistance Relaxation properties can be obtained.

Here, in the copper alloy for electronic / electric equipment of the present invention, any one or more of Ti, Cr, Zr, P, and B is further added in a total amount of 0.01 mass% or more and 2.0 mass%. It may be included within the following range.
Elements such as Ti, Cr, Zr, P, and B have the effect of improving strength by forming precipitates. Therefore, the strength can be further improved by appropriately adding these elements.

Moreover, in the copper alloy for electronic / electrical equipment of the present invention, any one or more of Mg, Sn, Zn, Al, and Ag is added in a total amount of 0.01 mass% to 2.0 mass%. It may be included within the range.
Elements such as Mg, Sn, Zn, Al, and Ag have a function of improving the strength by dissolving in a copper mother. Therefore, the strength can be further improved by appropriately adding these elements.

Moreover, in the copper alloy for electronic / electrical devices of the present invention, it is preferable that the average crystal grain size is in the range of 0.5 μm or more and 100 μm or less.
In this case, since the average crystal grain size is relatively fine within the range of 0.5 μm or more and 100 μm or less, the strength and bending workability can be improved reliably. In addition, as described above, since the special grain boundary length ratio (Lσ / L) is defined, the stress relaxation resistance can be maintained even if the crystal grain size is fine.
In order to achieve the above-described effects, the average crystal grain size is preferably in the range of 1.0 to 75 μm, more preferably in the range of 2.0 to 50 μm.

Moreover, in the copper alloy for electronic / electrical equipments of this invention, it is preferable that 0.2% yield strength has a mechanical characteristic of 400 Mpa or more.
When the 0.2% proof stress is 400 MPa or more, plastic deformation does not easily occur, so that it is particularly suitable for electronic / electronic device parts such as terminals such as connectors, relays, and lead frames.

  Further, in the copper alloy for electronic and electrical equipment of the present invention, the X-ray diffraction intensity from the {111} plane on the material surface is I {111}, the X-ray diffraction intensity from the {200} plane is I {200}, The X-ray diffraction intensity from the {220} plane is I {220}, the X-ray diffraction intensity from the {311} plane is I {311}, and the X-ray diffraction intensity from the {331} plane is I {331}, {420 } X-ray diffraction intensity from the plane is I {420}, and the ratio R {220} of the X-ray diffraction intensity from the {220} plane is R {220} = I {220} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}), it is preferable that R {220} is 0.8 or less.

The {220} plane is due to the rolling texture, and when bending is performed so that the bending axis is parallel to the rolling direction, the sliding system is less likely to act on the bending stress direction. It becomes a relationship. Therefore, local deformation occurs during bending, and cracks are likely to occur. Therefore, by defining the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface as 0.8 or less, it becomes possible to improve the bending workability.
In order to surely achieve the above-described effects, the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface is preferably 0.75 or less, and 0.7 or less. More preferably.

The copper alloy thin plate for electronic / electric equipment of the present invention is made of the above-described rolled material of copper alloy for electronic / electric equipment, and has a thickness in the range of 0.01 mm to 2.0 mm.
The copper alloy sheet for electronic and electrical equipment with this structure has excellent strength-bending balance and excellent stress relaxation characteristics, so connectors, other terminals, movable conductive pieces of electromagnetic relays, lead frames, etc. Can be suitably used.
Here, in the copper alloy thin plate for electronic / electrical equipment of the present invention, Sn plating may be applied to the surface.

The component for electronic / electrical equipment of the present invention is characterized by comprising the above-described copper alloy for electronic / electrical equipment.
Furthermore, the component for electronic / electrical equipment of the present invention is characterized by comprising the above-described copper alloy thin plate for electronic / electrical equipment.
The electronic / electrical device parts in the present invention include terminals, connectors, relays, lead frames and the like.

The terminal of the present invention is characterized by comprising the above-described copper alloy for electronic and electrical equipment.
Furthermore, the terminal of the present invention is characterized by comprising the above-described copper alloy thin plate for electronic and electrical equipment.
The terminals in the present invention include connectors and the like.

  The components and terminals for electronic / electrical devices with this structure are manufactured using copper alloy for electronic / electrical devices with excellent strength, bending workability, and stress relaxation resistance. Residual stress is less likely to be relaxed. For example, when the structure is made to press against the mating conductive material by the spring property of the bent portion, the contact pressure with the mating conductive member can be maintained. Further, it is possible to reduce the thickness of parts for electronic / electrical equipment and terminals.

  According to the present invention, the copper for electronic / electric equipment has excellent proof stress-bending balance and is particularly excellent in stress relaxation resistance, and is suitable for electronic / electric equipment parts such as terminals of connectors, relays, lead frames, etc. Alloys, copper alloy thin plates for electronic / electrical equipment, electronic / electrical equipment parts and terminals can be provided.

It is a flowchart which shows an example of the manufacturing method of the copper alloy for electronic and electrical apparatuses which is this embodiment.

Hereinafter, embodiments of the present invention will be described.
The copper alloy for electronic / electric equipment according to the present embodiment contains Ni in an amount of 1.0 mass% to 5.0 mass%, Si is contained in an amount of 0.1 mass% to 1.5 mass%, and the remainder is made of Cu and inevitable impurities. Further, the Ni / Si (mass ratio) is in the range of 2.0 or more and 6.0 or less.

  Moreover, the copper alloy for electronic / electric equipment which is this embodiment may substitute Co, Mn, Fe for a part of the Ni described above. Specifically, Ni is contained in an amount of 1.0 mass% or more, and one or more of Co, Mn, and Fe are contained, and the total content of Ni, Co, Mn, and Fe is 1 0.0 mass% to 5.0 mass% or less, Si is contained in an amount of 0.1 mass% or more and 1.5 mass% or less, and the remainder is composed of Cu and inevitable impurities, and (Ni + Co + Mn + Fe) / Si (mass ratio) is 2 It may be within the range of 0.0 or more and 6.0 or less.

Furthermore, the copper alloy for electronic / electrical equipment which is this embodiment is 0.01 mass% or more and 2.0 mass% or less in total on any 1 type or 2 types or more in Ti, Cr, Zr, P, and B. It may be included within the range.
Moreover, the copper alloy for electronic / electrical equipment which is this embodiment is 0.01 mass% or more and 2.0 mass% or less in total in any 1 type or 2 types or more in Mg, Sn, Zn, Al, and Ag. It may be included within the range.

In the copper alloy for electronic / electric equipment according to the present embodiment, the measurement area of 1000 μm ² or more is measured at a measurement interval of 0.1 μm by the EBSD method, and the CI value analyzed by the data analysis software OIM is 0. The analysis is performed except for the measurement points that are less than or equal to 1, and the crystal grain boundaries are defined as the crystal grain boundaries between the measurement points where the azimuth difference between adjacent measurements exceeds 15 °, and Σ3, Σ9, Σ27a, and Σ27b for all the grain boundary lengths L The special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths, is 30% or more.

  Further, in the copper alloy for electronic / electric equipment according to this embodiment, the X-ray diffraction intensity from the {111} plane on the material surface is I {111}, and the X-ray diffraction intensity from the {200} plane is I {200. }, The X-ray diffraction intensity from the {220} plane is I {220}, the X-ray diffraction intensity from the {311} plane is I {311}, and the X-ray diffraction intensity from the {331} plane is I {331}, The X-ray diffraction intensity from the {420} plane is I {420}, and the ratio of the X-ray diffraction intensity from the {200} plane R {200} is R {200} = I {200} / (I {111} + I When {200} + I {220} + I {311} + I {331} + I {420}), R {200} is 0.2 or more.

Furthermore, in the copper alloy for electronic / electric equipment according to the present embodiment, the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface is expressed as R {220} = I {220} / (I When {111} + I {200} + I {220} + I {311} + I {331} + I {420}), R {220} is set to 0.8 or less.
In addition, when the copper alloy for electronic / electrical equipment which is this embodiment is used as a rolled plate, the above-mentioned X-ray diffraction intensity is measured on the plate surface (rolled surface) of the rolled plate.

  Moreover, in the copper alloy for electronic / electrical equipment which is this embodiment, the average crystal grain size (including twins) is in the range of 0.5 μm to 100 μm.

  Here, the reason why the component composition, the special grain boundary length ratio (Lσ / L), the X-ray diffraction intensity, and the average crystal grain size are defined as described above will be described below.

[Ni]
Ni is an element that forms fine precipitates dispersed in the parent phase of copper when co-added with Si, and has the effect of greatly improving strength while maintaining conductivity.
Here, when the Ni content is less than 1.0 mass%, the number of precipitates is insufficient, and the strength may not be sufficiently improved. On the other hand, if the Ni content exceeds 5.0 mass%, cracks may occur during hot working.
From the above, in this embodiment, the Ni content is set within a range of 1.0 mass% to 5.0 mass%. In order to secure the number of precipitates and improve the strength reliably, the Ni content is preferably set to 1.5 mass% or more. Moreover, in order to suppress the crack at the time of hot processing reliably, it is preferable to make content of Ni into 4.0 mass% or less.

[Si]
Si is an element that forms fine precipitates dispersed in the copper matrix by being co-added with Ni, and has the effect of greatly improving the strength while maintaining the electrical conductivity.
Here, when the Si content is less than 0.1 mass%, the number of precipitates is insufficient, and the strength may not be sufficiently improved. On the other hand, if the Si content exceeds 1.5 mass%, cracks may occur during hot working.
From the above, in this embodiment, the Si content is set within a range of 0.1 mass% or more and 1.5 mass% or less. In addition, in order to ensure the number of precipitates and to surely improve the strength, the Si content is preferably set to 0.3 mass% or more. Moreover, in order to suppress the crack at the time of hot processing reliably, it is preferable to make content of Si into 1.3 mass% or less.

[Mass ratio of Ni and Si: Ni / Si]
Ni and Si form fine precipitates dispersed in the copper matrix as described above. This deposit consists of an intermetallic compound mainly composed of Ni ₂ Si.
Here, when the mass ratio Ni / Si of Ni and Si is less than 2.0, the number of precipitates is insufficient, and the strength may not be sufficiently improved. Moreover, there exists a possibility that electrical conductivity may fall with excess Si. On the other hand, when the mass ratio Ni / Si of Ni and Si exceeds 6.0, the number of precipitates may be insufficient and the strength may not be sufficiently improved. In order to ensure that the above-described effects are achieved, it is preferable that the mass ratio of Ni and Si: Ni / Si is in the range of 3.0 to 5.0.

[Co, Mn, Fe]
Like Ni, elements such as Co, Mn, and Fe form fine precipitates made of an intermetallic compound together with Si, and have the effect of greatly improving strength while maintaining conductivity. Therefore, Co, Mn, and Fe can be substituted for part of Ni.
Here, when the Ni content is less than 1.0 mass% and the total content of Ni, Co, Mn, and Fe is 1.0 mass% or less, the number of fine precipitates is insufficient and the strength is reduced. There is a possibility that it cannot be improved sufficiently. On the other hand, when the total content of Ni, Co, Mn, and Fe exceeds 5.0 mass%, cracks may occur during hot working.
From the above, in this embodiment, the Ni content is set within a range of 1.0 mass% or more and the total content of Ni, Co, Mn, and Fe is within a range of 1.0 mass% to 5.0 mass%. ing. In order to surely suppress cracking during hot working, the total content of Ni, Co, Mn, and Fe is preferably set to 4.0 mass% or less.

[Mass ratio of Ni, Co, Mn, Fe and Si: (Ni + Co + Mn + Fe) / Si]
Ni, Co, Mn, Fe and Si form fine precipitates dispersed in the copper matrix as described above. This deposit consists of an intermetallic compound mainly composed of Ni ₂ Si.
Here, when the mass ratio of Ni, Co, Mn, Fe and Si: (Ni + Co + Mn + Fe) / Si is less than 2.0, the number of precipitates may be insufficient, and the strength may not be sufficiently improved. is there. Moreover, there exists a possibility that electrical conductivity may fall with excess Si. On the other hand, if the mass ratio of Ni, Co, Mn, Fe and Si: (Ni + Co + Mn + Fe) / Si exceeds 6.0, the number of precipitates may be insufficient and the strength may not be sufficiently improved. . In order to surely achieve the above-described effects, it is preferable that the mass ratio of Ni, Co, Mn, Fe and Si: (Ni + Co + Mn + Fe) / Si is within a range of 3.0 to 5.0. .

[Ti, Cr, Zr, P, B]
Elements such as Ti, Cr, Zr, P, and B form a precipitate made of an intermetallic compound together with Cu, Ni, and Si, and have an effect of greatly improving strength while maintaining conductivity. Therefore, it is preferable to add appropriately when further improving the strength.
Here, when the total content of any one or more of Ti, Cr, Zr, P, and B is less than 0.01 mass%, the above-described effects can be reliably achieved. It may not be possible. On the other hand, when the total content of any one or more of Ti, Cr, Zr, P, and B exceeds 2.0 mass%, the conductivity may be significantly reduced.
From the above, when adding elements such as Ti, Cr, Zr, P, and B, the total content of any one or more of Ti, Cr, Zr, P, and B is 0. It is preferable to be within the range of 0.01 mass% or more and 2.0 mass% or less.

[Mg, Sn, Zn, Al, Ag]
Elements such as Mg, Sn, Zn, Al, and Ag are dissolved in the copper matrix and have the effect of significantly improving the strength. Therefore, it is preferable to add appropriately when further improving the strength.
Here, when the total content of any one or more of Mg, Sn, Zn, Al, and Ag is less than 0.01 mass%, the above-described effects can be reliably achieved. It may not be possible. On the other hand, when the total content of any one or more of Mg, Sn, Zn, Al, and Ag exceeds 2.0 mass%, the conductivity may be significantly reduced.
From the above, when adding elements such as Mg, Sn, Zn, Al, and Ag, the total content of any one or more of Mg, Sn, Zn, Al, and Ag is 0. It is preferable to be within the range of 0.01 mass% or more and 2.0 mass% or less.

[Inevitable impurities]
Note that inevitable impurities other than the elements described above include Ca, Sr, Ba, Sc, Y, rare earth elements, Hf, V, Nb, Ta, Mo, W, Re, Ru, Os, Se, Te, Rh, Ir. , Pd, Pt, Au, Cd, Ga, In, Ge, As, Sb, Tl, Pb, Bi, S, O, C, Be, N, H, Hg, and the like. These inevitable impurities are desirably 0.3% by mass or less in total.

[Special grain boundary length ratio (Lσ / L)]
The special grain boundary is a grain boundary with high crystallinity (a grain boundary with little disorder of atomic arrangement), and thus it becomes difficult to be a starting point of fracture during processing. Therefore, when the special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b with respect to all the grain boundary lengths L, is increased, It is possible to reduce the ratio of grain boundaries that are the starting points of fracture, and to improve bending workability. In addition, by introducing special grain boundaries in the structure with an increased {200} plane ratio, which will be described later, the starting point of fracture during bending is greatly reduced due to a synergistic effect, and bending workability is dramatically increased. To do. Furthermore, since special grain boundaries are slower in diffusion than random grain boundaries, even if the grain size is reduced by increasing the special grain boundary length ratio (Lσ / L), the stress relaxation resistance Can be prevented from deteriorating.
Therefore, in this embodiment, the special grain boundary length ratio (Lσ / L) is set to 30% or more. In order to achieve the above-described effects, the special grain boundary length ratio (Lσ / L) is preferably 35% or more, and more preferably 40% or more. More preferably, it is 50% or more.
The CI value (reliability index) when analyzed by the analysis software OIM of the EBSD device is small when the crystal pattern of the measurement point is not clear, and the analysis result is obtained when the CI value is 0.1 or less. Difficult to trust. Therefore, in the present embodiment, measurement points with low reliability whose CI value is 0.1 or less are excluded.

[X-ray diffraction intensity ratio: R {200}]
Since the {200} plane has an azimuth relationship in which the sliding system is easily active with respect to the stress direction of bending, local deformation can be suppressed, and generation of cracks during bending can be suppressed. It becomes possible. Further, by increasing the {200} plane ratio in the above-described structure with a high special grain boundary ratio, the starting point of fracture during bending is greatly reduced due to a synergistic effect, and the bending workability is dramatically increased.
For this reason, it is possible to improve the bending workability by setting the ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface to 0.2 or more. Here, the ratio R {200} of the X-ray diffraction intensity from the {200} plane is preferably 0.25 or more, and more preferably 0.3 or more, even within the above range.
The upper limit of the ratio R {200} of the X-ray diffraction intensity from the {200} plane is not particularly specified, but is preferably 0.9 or less.

[X-ray diffraction intensity ratio: R {220}]
The {220} plane on the surface of the material is due to the rolling texture. When the ratio of the {220} plane is increased, when the bending process is performed in the direction perpendicular to the rolling direction, the stress direction of the bending process is increased. On the other hand, it becomes an orientation relationship in which the sliding system is difficult to activate. Thereby, a deformation | transformation generate | occur | produces locally at the time of a bending process, and causes a crack.
For this reason, by suppressing the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface to 0.8 or less, it is considered that the occurrence of cracks can be suppressed and the bending workability is improved. . Here, the ratio R {220} of the X-ray diffraction intensity from the {220} plane is preferably 0.75 or less and more preferably 0.7 or less even within the above range.
The lower limit of the ratio R {220} of the X-ray diffraction intensity from the {220} plane is not particularly specified, but is preferably 0.1 or more.

[Average crystal grain size]
It is known that the crystal grain size of the material also has some influence on the stress relaxation resistance. Generally, the stress relaxation resistance decreases as the crystal grain size decreases. In the case of the copper alloy for electronic / electric equipment according to this embodiment, good stress relaxation can be achieved by appropriately adjusting the ratio of the component composition and each alloy element and by appropriately adjusting the ratio of the special grain boundary having high crystallinity. Since the characteristics can be secured, the crystal grain size can be reduced to improve the strength and bending workability.
Therefore, in the copper alloy for electronic and electrical equipment according to the present embodiment, the average crystal grain size of the crystal grains constituted by the grain boundaries (random grain boundaries and special grain boundaries) is in the range of 0.5 μm to 100 μm. It is preferable that In order to further improve the stress relaxation resistance, the average grain size is preferably 1.0 μm or more, and more preferably 2.0 μm or more. Moreover, in order to ensure the strength and bending workability, the average crystal grain size is preferably 75 μm or less, and more preferably 50 μm or less.
As described above, in the copper alloy for electronic / electric equipment according to the present embodiment, it is preferable to adjust the average crystal grain size according to the required characteristics.

  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. Although it is desirable to use 4NCu (oxygen-free copper or the like) having a purity of 99.99% or more as the copper raw material, scrap may be used as the raw material. Further, for the addition of various elements, an elemental element or a mother alloy can be used. Moreover, you may melt | dissolve the raw material containing various elements with a copper raw material. Further, recycled materials and scrap materials may be used.
An atmospheric furnace may be used for melting the raw material, but an atmosphere furnace having a vacuum furnace, an inert gas atmosphere, or a reducing atmosphere may be used to suppress oxidation of the additive element.
Next, the copper alloy melt whose components are adjusted is cast by an appropriate casting method, for example, a batch casting method such as die casting, a continuous casting method, a semi-continuous casting method, or the like to obtain an ingot.

[Heating step: S02]
Thereafter, if necessary, a homogenization heat treatment is performed in order to eliminate segregation of the ingot and make the ingot structure uniform. Alternatively, a solution heat treatment is performed to dissolve the crystallized product and the precipitate. The conditions for this heat treatment are not particularly limited, but usually it may be heated at 700 to 1100 ° C. for 5 minutes to 24 hours. When the heat treatment temperature is less than 700 ° C. or the heat treatment time is less than 5 minutes, there is a possibility that a sufficient homogenization effect or solution effect cannot be obtained. On the other hand, if the heat treatment temperature exceeds 1100 ° C., a part of the segregated part may be dissolved, and if the heat treatment time exceeds 24 hours, only the cost increases. The cooling conditions after the heat treatment may be determined as appropriate, but usually water quenching may be performed. After the heat treatment, chamfering is performed as necessary.

[Hot working process: S03]
Next, hot working may be performed on the ingot in order to increase the efficiency of roughing and make the structure uniform. The conditions for this hot working are not particularly limited, but it is usually preferable that the starting temperature is 600 to 1100 ° C., the finishing temperature is 300 to 850 ° C., and the working rate is about 10 to 99%. The ingot heating up to the hot working start temperature may also serve as the heating step S02 described above. Cooling conditions after hot working may be determined as appropriate, but usually water quenching may be performed. In addition, after hot processing, it chamfers as needed. Although it does not specifically limit about the processing method of hot processing, What is necessary is just to apply hot rolling, when a final shape is a board or a strip. If the final shape is a wire or a rod, extrusion or groove rolling may be applied, and if the final shape is a bulk shape, forging or pressing may be applied.

[Roughing process: S04]
Next, roughing is performed on the ingot subjected to the homogenization treatment in the heating step S02 or the hot-worked material subjected to the hot working S03 such as hot rolling. The temperature condition in the roughing step S04 is not particularly limited, but is preferably in the range of −200 ° C. to + 200 ° C. that is cold or warm processing. The processing rate of roughing is also not particularly limited, but is usually about 10 to 99%, preferably 50 to 99%. Although the processing method is not particularly limited, rolling may be applied when the final shape is a plate or strip. When the final shape is a wire or a rod, extrusion or groove rolling can be applied. When the final shape is a bulk shape, forging or pressing can be applied. It should be noted that S02 to S04 may be repeated for thorough solution.

[Intermediate heat treatment step: S05]
After the rough or warm processing step S04, an intermediate heat treatment is performed for thorough solution treatment and recrystallization. The preferable heating temperature and heating time of the intermediate heat treatment vary depending on the specific heat treatment method, as will be described below. That is, as a specific method of the intermediate heat treatment step S05, a batch-type heating furnace may be used, or continuous heating may be performed using a continuous annealing line. When using a batch-type heating furnace, it is desirable to heat at a temperature of 300 to 800 ° C. for 5 minutes to 24 hours, and when using a continuous annealing line, the heating temperature is 500 to 900 ° C., and It is preferable to keep the temperature within the range without holding or for about 1 second to 5 minutes. The atmosphere for the intermediate heat treatment is preferably a non-oxidizing atmosphere (nitrogen gas atmosphere, inert gas atmosphere, reducing atmosphere).
The cooling conditions after the intermediate heat treatment are not particularly limited, but usually water quenching may be performed.
If necessary, the roughing step S04 and the intermediate heat treatment step S05 may be repeated a plurality of times.

[Intermediate processing step: S06]
Next, intermediate processing is performed on the intermediate heat treatment material that has undergone the intermediate heat treatment step S05. The intermediate processing step S06 is a finishing heat treatment step S07, which will be described later, and is a step performed to form a special grain boundary by strain-induced grain boundary movement, and the processing rate is preferably 1% or more and less than 40%. . When the processing rate is 40% or more, strain-induced grain boundary migration hardly occurs in the subsequent finishing heat treatment step S07, and general recrystallization (by the nucleation / growth mechanism) occurs. The special grain boundary length ratio (Lσ / L) may not be sufficiently improved. In the next finishing heat treatment step S07, in order to surely improve the special grain boundary length ratio (Lσ / L), the processing rate is preferably 1% or more and 30% or less, and preferably 1% or more and 25% or less. More preferably.
Here, the processing method is not particularly limited, but rolling is employed when the final form is a plate or a strip. In addition, forging, pressing, and groove rolling may be employed. The temperature is not particularly limited, but is preferably −200 to + 200 ° C. which is cold or warm so that precipitation does not occur.

[Finish heat treatment step: S07]
After the intermediate processing step S06, a finish heat treatment for recrystallization is performed. By performing this finishing heat treatment, strain-induced grain boundary migration occurs and a large number of special grain boundaries are formed. At this time, the holding temperature and the ultimate temperature are likely to cause strain-induced grain boundary migration when the temperature is lower than the general recrystallization temperature, but if the temperature is too low, strain-induced grain boundary migration does not occur.
As a specific method of the finish heat treatment step S07, a batch-type heating furnace may be used to precipitate an intermetallic compound containing Ni and Si. Or you may heat continuously using a continuous annealing line. When using a batch-type heating furnace, it is preferably heated at a temperature of 300 to 800 ° C. for 5 minutes to 24 hours, more preferably at a temperature of 400 to 700 ° C. for 5 minutes to 24 hours. Moreover, when using a continuous annealing line, it is preferable to make it the heating attainment temperature 350-900 degreeC, and hold | maintain at the temperature within the range, without holding | maintenance or for 1 second-about 5 minutes, and the heating attainment temperature is made 500-800 degreeC. Further, it is more preferable to hold at a temperature within the range without holding or for about 1 second to 5 minutes.
The atmosphere for the finish heat treatment is preferably a non-oxidizing atmosphere (nitrogen gas atmosphere, inert gas atmosphere, reducing atmosphere).
Furthermore, in order to suppress the release of strain in the temperature rising process to easily cause strain-induced grain boundary movement and to sufficiently form the special grain boundary, the temperature rising rate between 200 ° C. and 400 ° C. is set to 200 ° C. ° C / min. It is preferable to set it as the above, 600 degreeC / min. More preferably, the above is used.
Note that by repeating the intermediate working step S06 and the finish heat treatment step S07, strain-induced grain boundary movement is promoted and the special grain boundary length ratio (Lσ / L) increases, so the intermediate working step S06 and the finish heat treatment step S07. Is preferably repeated twice or more, more preferably three or more times.

[Aging heat treatment step: S08]
In the finishing heat treatment step S07, when sufficient precipitates of intermetallic compounds containing Ni and Si are not formed, aging heat treatment may be performed for further precipitation of intermetallic compounds containing Ni and Si. Good. The conditions for this aging heat treatment are not particularly limited, but it is usually desirable to heat at a heat treatment temperature of 200 to 600 ° C. for 5 minutes to 48 hours.

[Finishing process: S09]
Next, the finishing process may be performed to the final dimension and the final shape on the material subjected to the finishing heat treatment step S07 or the material subjected to the aging heat treatment S08. The processing method in the finish processing step S09 is not particularly limited, but when the final product form is a plate or a strip, rolling (cold rolling) may be applied. In addition, forging, pressing, groove rolling, or the like may be applied depending on the final product form. In the present embodiment, cold rolling is performed as the finishing process S09 to produce a rolled material.
What is necessary is just to select a processing rate suitably according to final board thickness and final shape. Here, if the processing rate is less than 1%, the effect of improving the yield strength may not be sufficiently obtained. On the other hand, if the processing rate exceeds 70%, the special grain boundary length ratio (Lσ / L) decreases and R {200} decreases due to the loss of the recrystallized structure to form the processed structure, R {220 } May increase, and the bending workability and the stress relaxation resistance may decrease. From the above, the processing rate in the finish processing step S09 is preferably 1 to 70%, more preferably 1 to 50%, and particularly preferably 5 to 40%. After the finish processing step S09, it may be used as a product as it is, but normally, it will be subjected to a lower temperature annealing.

[Low temperature annealing step: S10]
After the finish processing step S09, low temperature annealing is performed as necessary to improve stress relaxation resistance and low temperature annealing hardening, or to remove residual strain. In this low temperature annealing process S10, it is desirable to carry out at the temperature within the range of 150-800 degreeC for 0.1 second-24 hours. When the heat treatment temperature is low, the heat treatment may be performed for a long time, and when the heat treatment temperature is high, the heat treatment may be performed for a short time. If the temperature of the low-temperature annealing step S10 is less than 150 ° C. or the time of the low-temperature annealing step S10 is less than 0.1 seconds, there is a possibility that a sufficient effect of removing strain may not be obtained, while the temperature of the low-temperature annealing step S10 is 800 If it exceeds ° C., there is a risk of recrystallization, and if the time of the low-temperature annealing step S10 exceeds 24 hours, it only increases the cost. If the finishing process S09 is not performed, the low-temperature annealing process S10 may be omitted.

As described above, the copper alloy for electronic / electric equipment according to the present embodiment can be obtained. In this copper alloy for electronic / electric equipment, the 0.2% proof stress is 400 MPa or more.
Moreover, when rolling is applied as a processing method in the intermediate processing step S07 or the finishing processing step S09, a copper alloy thin plate (strip material) for electronic / electric equipment having a plate thickness of about 0.05 to 1.0 mm can be obtained. Such a thin plate may be used as it is for parts for electronic and electrical equipment, but Sn plating with a film thickness of about 0.1 to 10 μm is applied to one or both sides of the plate surface, and copper with Sn plating is provided. As an alloy strip, it is usually used for electronic and electrical equipment parts such as connectors and other terminals. In this case, the Sn plating method is not particularly limited. In some cases, a reflow treatment may be performed after electrolytic plating.
Furthermore, the electronic / electric device parts and terminals according to the present embodiment are manufactured by punching, bending, or the like the above-described copper alloy thin plate for electronic / electric devices.

In the copper alloy for electronic and electrical equipment according to the present embodiment configured as described above, Ni is contained in an amount of 1.0 mass% to 5.0 mass%, and Si is contained in an amount of 0.1 mass% to 1.5 mass%. The remainder is composed of Cu and inevitable impurities, and the composition is such that Ni / Si (mass ratio) is in the range of 2.0 to 6.0. Alternatively, Co, Mn, and Fe are added as a substitute for a part of Ni, and the Ni content is 1.0 mass% or more, and one or more of Co, Mn, and Fe are added. And the total content of Ni, Co, Mn, and Fe exceeds 1.0 mass% and is 5.0 mass% or less, and (Ni + Co + Mn + Fe) / Si (mass ratio) is within a range of 2.0 or more and 6.0 or less. The composition is as follows.
Therefore, it is possible to disperse fine precipitate particles made of an intermetallic compound mainly composed of Ni ₂ Si in the copper matrix, ensuring high electrical conductivity and greatly improving the strength. it can.

  In addition, in the copper alloy for electronic and electrical equipment according to the present embodiment, the special grain boundary length that is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b to all the grain boundary lengths L The thickness ratio (Lσ / L) is set to 30% or more, and the ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface (plate surface) is set to 0.2 or more. The presence ratio of the (200) plane, which has an orientation relationship in which the sliding system is likely to be active with respect to the stress direction of the bending process on the surface of the material, is high, and there is a grain boundary with high crystallinity (grain boundary with little disorder of atomic arrangement). Many bends will greatly improve bending workability, and the yield strength-bending balance will be dramatically improved. In addition, since the special grain boundary has a slower grain boundary diffusion than the random grain boundary, the stress relaxation resistance can be improved.

  Furthermore, in the copper alloy for electronic / electric equipment according to this embodiment, the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface (plate surface) is 0.8 or less. The ratio of the (220) plane, which is the rolling texture on the surface of the material, is reduced, it is possible to suppress the occurrence of cracks due to local deformation during bending, and the bending workability can be improved reliably. It becomes.

In the copper alloy for electronic / electric equipment according to the present embodiment, any one or two or more of Ti, Cr, Zr, P, and B are added in a range of 0.01 mass% to 2.0 mass% in total. When added within the range, the strength can be further improved by securing the number of precipitate particles dispersed in the copper matrix.
In the copper alloy for electronic / electric equipment according to the present embodiment, any one or more of Mg, Sn, Zn, Al, and Ag is further added in a range of 0.01 mass% to 2.0 mass% in total. When added in the above, the strength can be further improved by dissolving these elements in the copper matrix.

  Moreover, in the copper alloy for electronic / electrical equipment which is this embodiment, since an average crystal grain diameter is made into the range of 0.5 micrometer or more and 100 micrometers or less, intensity | strength and bending workability can be improved reliably. . Here, in the copper alloy for electronic / electric equipment according to the present embodiment, the special grain boundary length ratio (Lσ / L) is set to 30% or more, so that it is possible to prevent the stress relaxation resistance from deteriorating. Therefore, strength, bending workability, and stress relaxation resistance can be improved in a well-balanced manner.

  Furthermore, in the copper alloy for electronic and electrical equipment according to the present embodiment, since 0.2% proof stress has mechanical characteristics of 400 MPa or more, it is not easily plastically deformed, and terminals such as connectors, relays, It can be suitably used as a material for electronic device parts such as lead frames.

  Since the copper alloy thin plate for electronic / electric equipment according to the present embodiment is made of the above-mentioned copper alloy rolled sheet for electronic / electric equipment, it has excellent stress relaxation resistance, and is suitable for connectors, other terminals, and electromagnetic relays. It can be suitably used for a movable conductive piece, a lead frame, and the like.

  In addition, the electronic device parts and terminals according to the present embodiment are manufactured using the above-described copper alloy for electronic devices, and thus have high yield strength and excellent bending workability. Even if it is a simple shape, there will be no cracks and the reliability will be improved. Furthermore, since it has excellent stress relaxation resistance, it can be used in a high temperature environment.

As described above, the copper alloy for electronic / electric equipment, the copper alloy thin plate for electronic / electric equipment, the component for electronic / electric equipment, and the terminal according to the embodiment of the present invention have been described, but the present invention is not limited thereto. The invention 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 manufacturing a copper alloy for electronic / electric equipment has been described with reference to the flowchart of FIG. 1, but the manufacturing method is not limited to this embodiment, The production 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. In addition, the following examples are for explaining the effects of the present invention, and the configurations, processes, and conditions described in the examples do not limit the technical scope of the present invention.

A copper raw material made of oxygen-free copper (ASTM B152 C10100) having a purity of 99.99% by mass or more was prepared, charged in a high-purity graphite crucible, and melted at high frequency 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 Tables 1 and 2, and poured into a carbon mold to produce an ingot. Here, the size of the ingot was about 25 mm thick × about 50 mm wide × about 200 mm long.
Subsequently, each ingot was subjected to water quenching as a homogenization treatment (heating step S02) after being held at 980 ° C. for 4 hours in an Ar gas atmosphere.

  Next, hot rolling was performed as a hot working step S03. Reheating so that the hot rolling start temperature becomes 980 ° C., the hot rolling at a rolling rate of about 50% is performed so that the width direction of the ingot becomes the rolling direction, and the rolling end temperature is 300 to 800 ° C. The water quenching was performed. Thereafter, cutting and surface grinding were performed to produce a hot rolled material having a thickness of about 11 mm × width of about 160 mm × length of about 100 mm. The presence or absence of cracks was confirmed in this hot working step S03. The confirmation results are shown in Tables 3 and 4. In addition, when the crack generate | occur | produced by hot processing, the subsequent process and evaluation were stopped.

Thereafter, the roughing step S04 and the intermediate heat treatment step S05 were each performed once or repeated twice.
Specifically, when each of the roughing step S04 and the intermediate heat treatment step S05 is performed once, the intermediate heat treatment for recrystallization is performed after cold rolling (roughing) at a rolling rate of about 90% or more. As above, heat treatment was performed at 300 to 800 ° C. for 5 minutes to 24 hours, or at 500 to 900 ° C. for 1 second to 5 minutes, and water quenched. Thereafter, the rolled material was cut, and surface grinding was performed to remove the oxide film.
On the other hand, when each of the roughing step S04 and the intermediate heat treatment step S05 is performed twice, after performing the primary cold rolling (primary roughing) with a rolling rate of about 50 to 90%, as the primary intermediate heat treatment, 300 to Secondary cold rolling (secondary roughing) with a rolling rate of about 50 to 90% after heat treatment at 800 ° C for 5 minutes to 24 hours or 500 to 900 ° C for 1 second to 5 minutes. And subjected to a secondary intermediate heat treatment at 300 to 800 ° C. for 5 minutes to 24 hours, or 500 to 900 ° C. for 1 second to 5 minutes, and water quenching was performed. Thereafter, the rolled material was cut, and surface grinding was performed to remove the oxide film.

Next, cold rolling was performed under the conditions described in Tables 3 and 4 as the intermediate processing step S06. Thereafter, as a finish heat treatment step S07, heat treatment was performed under the conditions described in Tables 3 and 4 using a salt bath or a rapid heat treatment furnace, and water quenching was performed.
The intermediate processing step S06 and the finish heat treatment step S07 were repeated. Tables 3 and 4 list the number of repetitions of the intermediate processing step S06 and the finish heat treatment step S07.

Next, as an aging heat treatment step S08, water quenching was performed by holding at a temperature described in Tables 3 and 4 for 8 hours using a salt bath.
After that, cold rolling was performed at the rolling rates described in Tables 3 and 4 as the finish rolling step S09.
Finally, after performing low-temperature annealing at 200 to 500 ° C. for 1 second to 1 hour, water quenching, cutting and surface polishing, and then a strip for property evaluation having a thickness of 0.20 mm × width of about 160 mm Was produced.

  For these strips for property evaluation, the special grain boundary length ratio (Lσ / L), the average crystal grain size, the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the plate surface, the { The ratio R {200} of the X-ray diffraction intensity from the 200} plane, electrical conductivity, mechanical properties (yield strength), bending workability, and stress relaxation resistance were evaluated. The test method and measurement method for each evaluation item are as follows.

[Special grain boundary length ratio (Lσ / L)]
Using a plane perpendicular to the width direction of rolling, that is, a TD plane (Transverse direction) as an observation plane, and using an EBSD measuring device and OIM analysis software, crystal grain boundaries (special grain boundaries and random grain boundaries) and crystals are as follows: The orientation difference distribution was measured.
After mechanical polishing using water-resistant abrasive paper and diamond abrasive grains, final polishing was performed using a colloidal silica solution. And an EBSD measuring device (Quanta FEG 450 made by FEI, EDAX / TSL (current AMETEK) OIM Data Collection) and analysis software (EDAX / TSL (current AMETEK) OIM Data Analysis ver. 5.3). ) To analyze the orientation difference of each crystal grain except for the measurement point where the acceleration value of electron beam is 20 kV, the measurement interval is 0.1 μm and the measurement area is 1000 μm ² or more and the CI value is 0.1 or less. A crystal grain boundary was defined between the measurement points where the orientation difference between adjacent measurement points was 15 ° or more. In addition, the total grain boundary length L of the crystal grain boundaries in the measurement range is measured to determine the position of the crystal grain boundary where the interface between adjacent crystal grains constitutes the special grain boundary, and among the special grain boundaries, Σ3, Σ9 , Σ27a, Σ27b The grain boundary length ratio Lσ / L between the sum Lσ of the grain boundary lengths and the total grain boundary length L of the crystal grain boundaries measured above is obtained, and the special grain boundary length ratio (Lσ / L).

[Crystal grain size]
As described above, the grain boundaries (special grain boundaries and random grain boundaries) and the crystal orientation difference distribution on the TD plane and the crystal orientation difference distribution are measured by the EBSD measuring apparatus and the OIM analysis software, and the grain boundaries are determined using the specified grain boundaries. Create a map, conform to the cutting method of JIS H 0501, draw 5 vertical and horizontal line segments at a time to the grain boundary map, count the number of crystal grains to be completely cut, The average value of the cutting length was defined as the average crystal grain size.

[X-ray diffraction intensity]
The X-ray diffraction intensity from the {111} plane on the plate surface is I {111}, the X-ray diffraction intensity I {200} from the {200} plane, the X-ray diffraction intensity I {220} from the {220} plane, { 311} plane X-ray diffraction intensity I {311}, {331} plane X-ray diffraction intensity I {331}, {420} plane X-ray diffraction intensity I {420} Measured with
A measurement sample was collected from the strip for characteristic evaluation, and the X-ray diffraction intensity around one rotation axis was measured with respect to the measurement sample by a reflection method. Cu was used as the target, and Kα X-rays were used. Measured under the conditions of tube current 40 mA, tube voltage 40 kV, measurement angle 40 to 150 °, measurement step 0.02 °, and after removing the background of X-ray diffraction intensity in the profile of diffraction angle and X-ray diffraction intensity, The integrated X-ray diffraction intensity I obtained by combining the peaks Kα1 and Kα2 from the diffraction surface was determined.
Then, from R {220} = I {220} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}), X from the {220} plane on the plate surface The ratio R {220} of the line diffraction intensity was calculated.
Further, from R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}), X from the {200} plane on the plate surface The ratio R {200} of the line diffraction intensity was calculated.

〔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.

(Mechanical properties)
A No. 13B test piece defined in JIS Z 2201 was taken from the strip for property evaluation, and Young's modulus E and 0.2% proof stress σ0.2 were measured by the offset method of JIS Z 2241. The test piece was collected in a direction perpendicular to the rolling direction.

[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 strip for property evaluation so that the rolling direction and the longitudinal direction of the test piece are perpendicular to each other. A W bending test was performed using a jig.
And when the outer peripheral part of the bending part was confirmed visually and a crack was observed, it determined as x, and the case where a fracture | rupture and a fine crack could not be confirmed was evaluated as (circle).

[Stress relaxation resistance]
The stress relaxation resistance test was conducted by applying a stress according to a method according to the Japan Copper and Brass Association Technical Standard JCBA-T309: 2004 cantilever screw method and holding it under the following conditions (temperature, time). The rate was measured.
As a test method, a specimen (width 10 mm) is taken from each characteristic evaluation strip in a direction parallel 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. The stress relaxation resistance was evaluated by measuring the residual stress ratio from a bending wrinkle after holding for 1000 hours at a temperature of 150 ° C. to evaluate the stress relaxation resistance. 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.
Those having a residual stress rate of 70% or more were evaluated as ◯, and those having a residual stress ratio of less than 70% were evaluated as ×.

  It shows in Table 1-6 about a component composition, manufacturing conditions, and an evaluation result.

In Comparative Example 1 in which the contents of Ni and Si were less than the range of the present invention, the proof stress and the stress relaxation resistance were low.
In Comparative Example 2 in which the Ni content was larger than the range of the present invention, large ear cracks occurred during hot rolling, and the subsequent processes and evaluation were stopped.
In Comparative Example 3 in which the total content of Ni, Co, Mn, and Fe is larger than the range of the present invention, large ear cracks occurred during hot rolling, and the subsequent steps and evaluation were stopped.

In Comparative Example 4 in which the mass ratio Ni / Si between Ni and Si was smaller than the range of the present invention, the proof stress and the stress relaxation resistance were low.
In Comparative Example 5 in which the mass ratio Ni / Si of Ni and Si was larger than the range of the present invention, large ear cracks occurred during hot rolling, so the subsequent steps and evaluation were stopped.
In Comparative Example 6 in which the special grain boundary length ratio (Lσ / L) and R {200} are lower than the range of the present invention, bending workability and stress relaxation resistance were insufficient.
In Comparative Example 7 in which the special grain boundary length ratio (Lσ / L) is lower than the range of the present invention, the bending workability and the stress relaxation resistance were insufficient.

  In contrast, the individual content of each alloy element is within the range defined by the present invention, the special grain boundary length ratio (Lσ / L), and the X-ray diffraction intensity of the {200} plane on the material surface Inventive example No. in which the ratio R {200} is within the scope of the present invention. It was confirmed that all Nos. 1 to 41 were excellent in yield strength, electrical conductivity, bending workability, and stress relaxation resistance.

  As described above, according to the example of the present invention, the electronic / electric equipment is particularly excellent in strength, bending workability and stress relaxation resistance, and suitable for electronic / electric equipment parts such as terminals of connectors, relays, lead frames, etc. It was confirmed that a copper alloy can be provided.

[Finish heat treatment step: S07]
After the intermediate processing step S06, a finish heat treatment for recrystallization is performed. By performing this finishing heat treatment, strain-induced grain boundary migration occurs and a large number of special grain boundaries are formed. At this time, the holding temperature and the ultimate temperature are likely to cause strain-induced grain boundary migration when the temperature is lower than the general recrystallization temperature, but if the temperature is too low, strain-induced grain boundary migration does not occur.
As a specific method of the finish heat treatment step S07, a batch-type heating furnace may be used to precipitate an intermetallic compound containing Ni and Si. Or you may heat continuously using a continuous annealing line. When using a batch-type heating furnace, it is preferably heated at a temperature of 300 to 800 ° C. for 5 minutes to 24 hours, more preferably at a temperature of 400 to 700 ° C. for 5 minutes to 24 hours. In the case of using a continuous annealing line, and reaches a temperature 500 to 800 ° C. pressurized heat and at a temperature within that range, no hold, or it is good preferable to hold about 1 second to 5 minutes.
The atmosphere for the finish heat treatment is preferably a non-oxidizing atmosphere (nitrogen gas atmosphere, inert gas atmosphere, reducing atmosphere).
Furthermore, in order to suppress the release of strain in the temperature rising process to easily cause strain-induced grain boundary movement and to sufficiently form the special grain boundary, the temperature rising rate between 200 ° C. and 400 ° C. is set to 200 ° C. ° C / min. It is preferable to set it as the above, 600 degreeC / min. More preferably, the above is used.
Note that by repeating the intermediate working step S06 and the finish heat treatment step S07, strain-induced grain boundary movement is promoted and the special grain boundary length ratio (Lσ / L) increases, so the intermediate working step S06 and the finish heat treatment step S07. Is preferably repeated twice or more, more preferably three or more times.

In order to solve this problem, the copper alloy for electronic and electrical equipment of the present invention contains Ni in an amount of 1.0 mass% to 5.0 mass%, Si in an amount of 0.1 mass% to 1.5 mass%, and the rest It consists of Cu and inevitable impurities and has a composition in which Ni / Si (mass ratio) is in the range of 2.0 or more and 6.0 or less, and a measurement area of 1000 μm ² or more by the EBSD method at a measurement interval of 0.1 μm step. Measured and analyzed with the exception of measurement points with a CI value of 0.1 or less analyzed by the data analysis software OIM, and a crystal grain boundary between the measurement points where the orientation difference between adjacent measurements exceeds 15 °, The special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b to all the grain boundary lengths L, is 30% or more, and the material surface {111} plane in X-ray diffraction intensity from I {111}, X-ray diffraction intensity from {200} plane from I {200}, X-ray diffraction intensity from {220} plane from I {220}, {311} plane X-ray diffraction intensity is I {311}, X-ray diffraction intensity from {331} plane is I {331}, X-ray diffraction intensity from {420} plane is I {420}, X-ray from {200} plane When the ratio R {200} of the diffraction intensity is R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}) , R {200} is 0.2 or more , and the ratio R {220} of the X-ray diffraction intensity from the {220} plane is R {220} = I {220} / (I {111} + I {200} + I in case of the {220} + I {311} + I {331} + I {420}), R {220} is 0.7 or less It is characterized by a door.

Here, since the {200} plane has an azimuth relationship in which the sliding system is likely to be active with respect to the stress direction of bending, local deformation can be suppressed. Furthermore, an increase in grain boundaries with high crystallinity (grain boundaries with less disorder of atomic arrangement) reduces the proportion of grain boundaries that are the starting point of fracture during bending. In the copper alloy for electronic and electrical equipment of the present invention, the yield strength-bending balance is drastically improved by these synergistic effects. In addition, the special grain boundary can improve the stress relaxation resistance because the grain boundary diffuses slower than the random grain boundary.
In order to achieve the above-mentioned effects and effects, the special grain boundary length ratio (Lσ / L) is preferably 45% or more, and more preferably 50% or more. The ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface is preferably 0.25 or more, and more preferably 0.3 or more.
Also, the {220} plane is due to the rolling texture, and when the bending process is performed so that the bending axis is parallel to the rolling direction, a sliding system is activated in the bending stress direction. It becomes difficult orientation relationship. Therefore, local deformation occurs during bending, and cracks are likely to occur.
Therefore, by defining the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface to 0.7 or less, it becomes possible to improve the bending workability.

In addition, the copper alloy for electronic and electrical equipment of the present invention contains 1.0 mass% or more of Ni, and contains one or more of Co, Mn, and Fe, and Ni, Co, Mn , Fe content is 1.0 mass% to 5.0 mass% or less, Si is contained 0.1 mass% or more and 1.5 mass% or less, the remainder is made of Cu and inevitable impurities, and (Ni + Co + Mn + Fe) / Si (Mass ratio) has a composition in the range of 2.0 or more and 6.0 or less, measures the measurement area of 1000μm ² or more by the EBSD method at the measurement interval of 0.1μm step, and analyzes it by the data analysis software OIM The analysis is performed except for the measurement points having a CI value of 0.1 or less, and the crystal grain boundary is defined as the crystal grain boundary between the measurement points where the orientation difference between adjacent measurements exceeds 15 °. The special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b, is 30% or more, and X from the {111} plane on the material surface X-ray diffraction intensity from I {111}, X-ray diffraction intensity from {200} plane is I {200}, X-ray diffraction intensity from {220} plane is I {220}, X-ray diffraction from {311} plane The intensity is I {311}, the X-ray diffraction intensity from the {331} plane is I {331}, the X-ray diffraction intensity from the {420} plane is I {420}, and the X-ray diffraction intensity from the {200} plane is When the ratio R {200} is R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}), R {200 } Is 0.2 or more , and the ratio R {220} of the X-ray diffraction intensity from the {220} plane is set to R {22 0} = I {220} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420}), R {220} is 0.7 or less It is characterized by that.

In the copper alloy for electronic and electrical equipment of the present invention configured as described above, Ni is contained in an amount of 1.0 mass% or more, and contains any one or more of Co, Mn, Fe, The total content of Ni, Co, Mn, and Fe is 1.0 mass% and 5.0 mass% or less, Si is contained 0.1 mass% or more and 1.5 mass% or less, and the remainder consists of Cu and inevitable impurities, Since (Ni + Co + Mn + Fe) / Si (mass ratio) has a composition in the range of 2.0 or more and 6.0 or less, Co, Mn, and Fe substitute a part of Ni, and Ni ₂ Precipitate particles composed of an intermetallic compound mainly containing Si can be dispersed in a copper matrix, and strength can be improved while ensuring high electrical conductivity.
Further, the special grain boundary length ratio (Lσ / L), which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b to all the grain boundary lengths L, is set to 30% or more. Since the ratio R {200} of the X-ray diffraction intensity from the {200} plane on the material surface is 0.2 or more, the yield strength-bending balance can be dramatically improved and excellent stress resistance Relaxation properties can be obtained.
Furthermore, it is possible to improve the bending workability by defining the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface to 0.7 or less.

Furthermore, in the copper alloy for electronic / electric equipment according to the present embodiment, the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface is expressed as R {220} = I {220} / (I When {111} + I {200} + I {220} + I {311} + I {331} + I {420}), R {220} is 0.7 or less .
In addition, when the copper alloy for electronic / electrical equipment which is this embodiment is used as a rolled plate, the above-mentioned X-ray diffraction intensity is measured on the plate surface (rolled surface) of the rolled plate.

[X-ray diffraction intensity ratio: R {220}]
The {220} plane on the surface of the material is due to the rolling texture. When the ratio of the {220} plane is increased, when the bending process is performed in the direction perpendicular to the rolling direction, the stress direction of the bending process is increased. On the other hand, it becomes an orientation relationship in which the sliding system is difficult to activate. Thereby, a deformation | transformation generate | occur | produces locally at the time of a bending process, and causes a crack.
For this reason, by suppressing the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface to 0.7 or less , it is considered that the occurrence of cracks can be suppressed and the bending workability is improved. .
The lower limit of the ratio R {220} of the X-ray diffraction intensity from the {220} plane is not particularly specified, but is preferably 0.1 or more.

Furthermore, in the copper alloy for electronic / electric equipment according to this embodiment, the ratio R {220} of the X-ray diffraction intensity from the {220} plane on the material surface (plate surface) is 0.7 or less . The ratio of the (220) plane, which is the rolling texture on the surface of the material, is reduced, it is possible to suppress the occurrence of cracks due to local deformation during bending, and the bending workability can be improved reliably. It becomes.

Claims (13)

Ni is contained in an amount of 1.0 mass% to 5.0 mass%, Si is contained in an amount of 0.1 mass% to 1.5 mass%, the remainder is made of Cu and inevitable impurities, and Ni / Si (mass ratio) is 2.0 to 6 Having a composition within the range of 0.0 or less,
The measurement area of 1000 μm ² or more is measured by the EBSD method at a measurement interval of 0.1 μm, and the analysis is performed except for the measurement point where the CI value analyzed by the data analysis software OIM is 0.1 or less. Special grain boundary length, which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b with respect to all the grain boundary lengths L. The thickness ratio (Lσ / L) is 30% or more,
The X-ray diffraction intensity from the {111} plane on the material surface is I {111}, the X-ray diffraction intensity from the {200} plane is I {200}, and the X-ray diffraction intensity from the {220} plane is I {220}. , The X-ray diffraction intensity from the {311} plane is I {311}, the X-ray diffraction intensity from the {331} plane is I {331}, the X-ray diffraction intensity from the {420} plane is I {420}, { The ratio of the X-ray diffraction intensity from the 200} plane, R {200}, is calculated as R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I { 420}), R {200} is 0.2 or more, copper alloy for electronic and electrical equipment, Ni is contained in an amount of 1.0 mass% or more and contains one or more of Co, Mn, and Fe, and the total content of Ni, Co, Mn, and Fe exceeds 1.0 mass%. 0.0 mass% or less, Si is contained in an amount of 0.1 mass% or more and 1.5 mass% or less, the remainder is made of Cu and inevitable impurities, and (Ni + Co + Mn + Fe) / Si (mass ratio) is 2.0 or more and 6.0 or less. Having a composition that falls within the range;
The measurement area of 1000 μm ² or more is measured by the EBSD method at a measurement interval of 0.1 μm, and the analysis is performed except for the measurement point where the CI value analyzed by the data analysis software OIM is 0.1 or less. Special grain boundary length, which is the ratio of the sum Lσ of the grain boundary lengths of Σ3, Σ9, Σ27a, and Σ27b with respect to all the grain boundary lengths L. The thickness ratio (Lσ / L) is 30% or more,
The X-ray diffraction intensity from the {111} plane on the material surface is I {111}, the X-ray diffraction intensity from the {200} plane is I {200}, and the X-ray diffraction intensity from the {220} plane is I {220}. , The X-ray diffraction intensity from the {311} plane is I {311}, the X-ray diffraction intensity from the {331} plane is I {331}, the X-ray diffraction intensity from the {420} plane is I {420}, { The ratio R {200} of the X-ray diffraction intensity from the 200} plane is changed to R {200} = I {200} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420 }), R {200} is 0.2 or more, copper alloy for electronic and electric equipments characterized by the above-mentioned.   Further, any one or more of Ti, Cr, Zr, P, and B is included within a total range of 0.01 mass% or more and 2.0 mass% or less. The copper alloy for electronic / electrical equipment of Claim 1 or Claim 2.   Further, any one or more of Mg, Sn, Zn, Al, and Ag is included within a total range of 0.01 mass% or more and 2.0 mass% or less. The copper alloy for electronic and electrical equipment according to any one of claims 3 to 4.   5. The copper alloy for electronic / electric equipment according to claim 1, wherein an average crystal grain size is in a range of 0.5 μm to 100 μm.   The copper alloy for electronic / electric equipment according to any one of claims 1 to 5, wherein the 0.2% proof stress has mechanical properties of 400 MPa or more.   The X-ray diffraction intensity from the {111} plane on the material surface is I {111}, the X-ray diffraction intensity from the {200} plane is I {200}, and the X-ray diffraction intensity from the {220} plane is I {220}. , The X-ray diffraction intensity from the {311} plane is I {311}, the X-ray diffraction intensity from the {331} plane is I {331}, the X-ray diffraction intensity from the {420} plane is I {420}, { The ratio R {220} of the X-ray diffraction intensity from the 220} plane is changed to R {220} = I {220} / (I {111} + I {200} + I {220} + I {311} + I {331} + I {420 }), R {220} is 0.8 or less, The copper alloy for electronic / electric equipment according to any one of claims 1 to 6, wherein:   It consists of a rolled material of the copper alloy for electronic / electric equipment as described in any one of Claims 1-7, and thickness exists in the range of 0.01 mm or more and 2.0 mm or less. Copper alloy sheet for electrical equipment.   The copper alloy thin plate for electronic / electric equipment according to claim 8, wherein the surface is plated with Sn.   A component for electronic / electric equipment comprising the copper alloy for electronic / electric equipment according to any one of claims 1 to 7.   A terminal comprising the copper alloy for electronic and electrical equipment according to any one of claims 1 to 7.   An electronic / electric equipment component comprising the copper alloy thin plate for electronic / electric equipment according to claim 8 or 9.   A terminal comprising the copper alloy thin plate for electronic / electrical equipment according to claim 8 or 9.

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