WO2011068134A1

WO2011068134A1 - Copper alloy sheet material having low young's modulus and method for producing same

Info

Publication number: WO2011068134A1
Application number: PCT/JP2010/071517
Authority: WO
Inventors: 佐藤　浩二; 洋金子; 立彦江口
Original assignee: 古河電気工業株式会社
Priority date: 2009-12-02
Filing date: 2010-12-01
Publication date: 2011-06-09
Also published as: EP2508634B1; CN102630251B; KR20120104553A; JP4809935B2; EP2508634A4; CN102630251A; US20120241056A1; EP2508634A1; JPWO2011068134A1

Abstract

Disclosed is a copper alloy sheet material for an electrical/electronic component, which has low Young's modulus that is required for an electrical/electronic component such as a connector. The copper alloy sheet material for an electrical/electronic component has an alloy composition containing 0.5-5.0% by mass of Ni and/or Co in total and 0.2-1.5% by mass of Si, with the balance made up of Cu and unavoidable impurities. The copper alloy sheet material for an electrical/electronic component has a 0.2% proof stress in the rolling direction of not less than 500 MPa, a conductivity of not less than 30% IACS, a Young's modulus of not more than 110 GPa and a bending/flexure coefficient of not more than 105 GPa.

Description

Copper alloy sheet having low Young's modulus and method for producing the same

The present invention relates to a copper alloy sheet having high strength and high conductivity suitable as materials for electric and electronic parts such as connectors, and further having a low Young's modulus, and a method for producing the same.

In recent years, with the development of the electronics industry, the wiring of various electric and electronic devices has become more complicated and highly integrated, and the opportunities for using copper alloys for electric and electronic parts have been increased accordingly. In particular, narrow pitches, low height, high reliability, and low cost are required for electrical and electronic parts such as connectors. Therefore, in order to satisfy these requirements, copper alloy sheet materials used for electrical and electronic parts such as connectors have high strength and conductivity, and at the same time, because they are thinned and pressed into complicated shapes. It is required that the press formability is excellent.

To be used as a terminal, the tensile strength in the rolling direction (RD) is 500MPa or more as the strength not to be deformed during insertion and removal or bending, and furthermore, the electrical conductivity is 30% IACS to suppress the generation of Joule heat due to energization. The above is preferable.

Also, conventionally, it has been required that the connector be miniaturized and that a large Young's modulus of the connector material be obtained so that a large stress can be obtained with a small displacement. However, the dimensional accuracy of the terminal itself becomes severe, and management standards such as die technology and press operation management, or variations in plate thickness and residual stress of connector materials become strict, which in turn causes an increase in cost. Therefore, recently, a connector material having a small Young's modulus is used, a structure in which the displacement of the spring is large, and a design that can tolerate variations in dimensions are being sought. Therefore, it is required that the Young's modulus in the rolling direction is 110 GPa or less, preferably 100 GPa or less.

So far, brass, phosphor bronze and the like have been generally used as connector materials. The Young's modulus in the rolling direction of both brass and phosphor bronze is about 110 to 120 GPa, which is smaller than the Young's modulus 128 GPa of pure copper, and is widely used as a low Young's modulus material. However, these copper alloys have a conductivity of 30% IACS or less, a low conductivity, and can not be used as a connector in applications where a large current flows. Therefore, Corson alloys having moderate conductivity have been attracting attention, and the amount used has been increasing. However, this Corson alloy has a Young's modulus of about 130 GPa, and in this point, the Young's modulus of the connector material is reduced. It has been demanded. In addition, depending on the connector designer, the connector may be designed not with Young's modulus but with a bending deflection coefficient (longitudinal elastic modulus at the time of bending test), and therefore, a low bending deflection coefficient is required. In general, Young's modulus represents the longitudinal elastic modulus under tensile stress, flexural deflection coefficient represents the longitudinal elastic modulus under complex stress of compression and tension at bending, and the values of Young's modulus and flexural deflection coefficient are Although different, when the Young's modulus is low, the bending deflection coefficient tends to be a low value.

The low Young's modulus and the low flexural deflection are achieved not only by adding zinc (Zn) and phosphorus (P) to copper but also by controlling the crystal orientation. For example, as described in Patent Document 1 and Patent Document 2, in pure copper, when rolled after heat treatment and recrystallization after rolling at a high working ratio, Cube orientation (100) <100 relative to the normal direction of rolling (ND) of the plate material By increasing>, the Young's modulus decreases and the flexibility becomes good. However, with the Corson alloy, it is difficult to control the Young's modulus by simply increasing the cold rolling ratio before recrystallization without increasing the Cube orientation.

Japanese Patent Application Laid-Open No. 55-54554 Patent No. 3009383

The present invention is a copper alloy sheet material for electrical and electronic components such as a connector which can simultaneously satisfy high strength, high conductivity and low Young's modulus required for materials for electrical and electronic components such as connectors with the development of electronics industry. And its purpose is to provide its manufacturing method.

According to the present invention, the following means are provided.
(1) An alloy composition containing 0.5 to 5.0% by mass and 0.2 to 1.5% by mass of Si in total of one or both of Ni and Co, and the balance being Cu and unavoidable impurities Copper having a 0.2% proof stress in the rolling direction of 500 MPa or more, a conductivity of 30% IACS or more, a Young's modulus of 110 GPa or less, and a bending deflection coefficient of 105 GPa or less Alloy plate material.
(2) The electrical / electronic component according to (1), wherein the area ratio of the (100) plane directed to the rolling direction obtained by analyzing using EBSD of the copper alloy sheet is 30% or more. Copper alloy sheet material.
(3) The area ratio of the (111) plane facing in the rolling direction obtained by analyzing using EBSD of the copper alloy sheet is 15% or less, as described in (1) or (2). Copper alloy sheet for electrical and electronic parts.
(4) The copper alloy sheet material for electric and electronic parts according to any one of (1) to (3), which further contains 0.05 to 0.5% by mass of Cr.
(5) Furthermore, it is characterized in that it contains 0.01 to 1.0% by mass in total of one or more selected from the group consisting of Zn, Sn, Mg, Ag, Mn and Zr. A copper alloy sheet material for electric and electronic parts according to any one of (4) to (4).
(6) A copper alloy sheet material for electric and electronic parts according to any one of (1) to (5), which is a material for a connector.
(7) A connector comprising the copper alloy sheet material for electric and electronic parts according to any one of (1) to (6).
(8) A method of producing a copper alloy sheet material for electric and electronic parts according to any one of (1) to (7), wherein casting, hot rolling or cold rolling is performed on a copper alloy giving said alloy composition. The following steps are carried out in this order: intermediate rolling 1, intermediate annealing, cold rolling 2, solution heat treatment, aging heat treatment, finish cold rolling, low temperature annealing, and further at least one of the following [1] and [2] or The manufacturing method of the copper alloy board material for electric and electronic parts characterized by performing both processings.
[1] Step of gradually cooling to 350 ° C. after the above hot rolling [2] Step of repeating the intermediate annealing and the cold rolling 2 twice or more

The copper-based alloy material according to the present invention or the copper alloy material obtained by the production method of the present invention has high strength and high required for materials for electrical and electronic parts such as connectors, as compared with conventional Corson-based alloys. It has a low Young's modulus without impairing the conductivity, and is suitable as a copper alloy material for electrical and electronic parts such as connectors.

A preferred embodiment of the copper alloy sheet of the present invention will be described in detail. Here, "copper alloy material" means one obtained by processing a copper alloy material into a predetermined shape (e.g., plate, strip, foil, bar, wire, etc.). Among them, a plate material refers to a plate having a specific thickness, being stable in shape and having a spread in the surface direction, and in a broad sense, it includes a bar material. Here, in the plate material, “material surface layer” means “plate surface layer”, and “depth position of material” means “position in the plate thickness direction”. The thickness of the plate is not particularly limited, but is preferably 8 to 800 μm, more preferably 50 to 70 μm, in consideration of the fact that the effects of the present invention are more apparent and suitable for practical applications.
Although the copper alloy sheet material of the present invention defines its characteristics by the accumulation ratio of atomic planes in a predetermined direction of the rolled sheet, it has the characteristics as the present invention as a copper alloy sheet material. The shape of the copper alloy plate is not limited to the plate and the strip, and in the present invention, the tube can be interpreted as a plate and handled.
First, the alloy composition of the copper alloy material of the present invention (a typical shape is a plate material), which is a precipitation type copper alloy material such as Corson type having a low Young's modulus and a low flexural deflection coefficient, Describe the organization.

(Component composition of copper alloy material)
The reasons for limitation of the chemical composition in the copper alloy material of the present invention, which is a premise for having high strength, will be described (all the contents "%" described herein are "% by mass").

(Ni: 0.5 to 5.0%)
Ni is an element which is contained together with Si to be described later, forms an Ni ₂ Si phase precipitated by aging treatment, and contributes to the improvement of the strength of the copper alloy material. When the content of Ni is too low, the Ni ₂ Si phase is insufficient, and the tensile strength of the copper alloy material can not be increased. On the other hand, when the content of Ni is too large, the conductivity decreases. In addition, the hot rolling processability is deteriorated. Therefore, the Ni content is in the range of 0.5 to 5.0%, preferably 1.5 to 4.0%.

(Co: 0.5 to 5.0%)
Co is an element which is contained together with Si to form a Co ₂ Si phase precipitated by aging treatment and contributes to the improvement of the strength of the copper alloy material. When it is desired to enhance the conductivity, it is preferable not to contain Ni but to contain Co alone. When the content of Co is too low, the Co ₂ Si phase runs short, and the tensile strength of the copper alloy material can not be increased. On the other hand, when the content of Co is too large, the conductivity decreases. In addition, the hot rolling processability is deteriorated. Therefore, the Co content is in the range of 0.5 to 5.0%, preferably 0.8 to 3.0%, and more preferably 1.1 to 1.7%.

These Ni and Co may contain both, but the total content thereof is 0.5 to 5.0%. When both Ni and Co are contained, both Ni ₂ Si and Co ₂ Si can be precipitated during the aging treatment to enhance the aging strength. If the total content is too small, the tensile strength can not be increased, and if too large, the electrical conductivity and the hot-rolling processability decrease. Therefore, the total content of Ni and Co is in the range of 0.5 to 5.0%, preferably 0.8 to 4.0%.

(Si)
Si is contained together with the Ni and Co to form a Ni ₂ Si or Co ₂ Si phase precipitated by the aging treatment, and contributes to the improvement of the strength of the copper alloy material. The content of Si is 0.2 to 1.5%, preferably 0.2 to 1.0%. The Si content is most preferably Ni / Si = 4.2 and Co / Si = 4.2 in terms of stoichiometry, for the best balance between conductivity and strength. Therefore, the content of Si is preferably such that Ni / Si, Co / Si, and (Ni + Co) / Si are in the range of 3.2 to 5.2, and more preferably 3.5 to 4.8. is there.

If it is out of this range and Si is contained in excess, the tensile strength of the copper alloy material can be increased, but the excess of Si forms a solid solution in the copper matrix and the conductivity of the copper alloy material Decreases. In addition, when Si is excessively contained, castability in casting and rolling workability in hot and cold also decrease, and casting cracking and rolling cracking easily occur. On the other hand, if it is out of this range and the content of Si is too small, precipitation phases of Ni ₂ Si or Co ₂ Si will be insufficient, and the tensile strength of the material can not be increased.

(Cr)
In addition to the above composition, 0.05 to 0.5 mass% of Cr may be contained. Cr has the effect of refining the crystal grains in the alloy and contributes to the improvement of the strength and bending workability of the copper alloy material. When the amount is too small, the effect is small, and when the amount is too large, a crystallized product is formed during casting and the aging strength is reduced.

(Other alloying elements)
In the copper alloy material of the present invention, Sn: 0.01 to 1.0%, Zn: 0.01 to 1.0%, Ag: 0.01 to 10% by mass as an additive element in addition to the above basic composition. One or two or more of 1.0%, Mn: 0.01 to 1.0%, Zr: 0.1 to 1.0%, Mg: 0.01 to 1.0% in total It can be contained as needed in an amount of 1.0%. Each of these elements has a common effect of improving either the high strength, conductivity or low Young's modulus that the copper alloy material of the present invention is intended to play, in addition to or instead of this. It is an element that further improves other properties (such as stress relaxation resistance). Below, the characteristic effect of each element and the significance of the content range are described.

(Sn)
Sn is an element that mainly improves the strength of the copper alloy material, and is selectively contained when used in applications that place importance on these properties. When the content of Sn is too small, the strength improvement effect is small. On the other hand, when Sn is contained, the conductivity of the copper alloy material is lowered. In particular, when the amount of Sn is too large, it becomes difficult to make the conductivity of the copper alloy material 30% IACS or more. Therefore, when it is contained, the content of Sn is in the range of 0.01 to 1.0%.

(Zn)
The addition of Zn can improve the thermal peelability and migration resistance of the solder. If the content of Zn is too low, the effect is small. On the other hand, when Zn is contained, the conductivity of the copper alloy material is lowered, and when Zn is too much, it is difficult to set the conductivity of the copper alloy material to 30% IACS or more. Therefore, the content of Zn is in the range of 0.01 to 1.0%.

(Ag)
Ag contributes to the increase in strength. If the content of Ag is too small, the effect is small. On the other hand, even if a large amount of Ag is contained, the strength increase effect is only saturated. Therefore, when it is contained, the content of Ag is in the range of 0.01 to 1.0%.

(Mn)
Mn mainly improves the workability in hot rolling. When the content of Mn is too small, the effect is small. On the other hand, when the amount of Mn is too large, the fluidity of the copper alloy during ingot formation deteriorates, and the ingot retention decreases. Therefore, when it is contained, the content of Mn is in the range of 0.01 to 1.0%.

(Zr)
Zr mainly refines crystal grains to improve the strength and bending workability of the copper alloy material. If the content of Zr is too small, the effect is small. On the other hand, when the amount of Zr is too large, a compound is formed, and the workability such as rolling of a copper alloy material is reduced. Therefore, when it is contained, the content of Zr is in the range of 0.01 to 1.0%.

(Mg)
Mg improves the stress relaxation resistance. Therefore, when stress relaxation resistance is required, it is selectively contained in the range of 0.01 to 1.0%. When the amount is too small, the effect of addition is small, and when the amount is too large, the conductivity decreases. Therefore, when it is contained, the content of Mg is in the range of 0.01 to 1.0%.
Note that Mg, Sn, and Zn improve the stress relaxation resistance by adding them to Cu-Ni-Si, Cu-Ni-Co-Si, and Cu-Co-Si copper alloys. The stress relaxation resistance is further improved by the synergetic effect when they are added together as compared to when each of them is added alone. In addition, it has the effect of significantly improving solder embrittlement.

The conductivity realized by the copper alloy sheet material of the present invention is 30% IACS or more, preferably 35% IACS or more, and more preferably 45% IACS or more. There is no particular upper limit, but it is practical that it is 60% IACS or less.
Further, a preferable range as a 0.2% proof stress in the rolling direction realized by the copper alloy material of the present invention is 500 MPa or more, preferably 650 MPa or more, and more preferably 800 MPa or more. There is no particular upper limit, but it is practical that it is 1100 MPa or less.
The bending deflection coefficient is preferably 105 GPa or less, more preferably 100 GPa or less. There is no particular lower limit, but it is practical that it is 60 GPa or more.
The Young's modulus is 110 GPa or less, more preferably 100 GPa or less. There is no particular lower limit, but it is practical that it is 70 GPa or more.

(Group organization)
The texture of the copper alloy material of the present invention is, in particular, a surface (100) facing RD in the analysis result from the rolling direction (RD) by the SEM-EBSD method in order to realize a low Young's modulus and a low flexural deflection coefficient. It is preferable to have a texture having an area ratio of 30% or more. Note that all crystal grains having an orientation in which the angle between the sheet rolling direction (RD) and the normal to the surface is 10 ° or less has a (100) plane facing the RD.

In the case of a copper alloy sheet, mainly, as shown below, a texture called Cube orientation, Goss orientation, Brass orientation, Copper orientation, S orientation, etc. is formed, and a crystal plane corresponding to them is present.

The formation of these textures differs depending on the processing and heat treatment method even in the case of the same crystal system. In the crystal orientation display method in this specification, the material rolling direction (RD) is taken along the X axis, the plate width direction (TD) as the Y axis, and the rolling normal direction (ND) as the Z axis orthogonal coordinate system. Using the index (hkl) of the crystal plane where each region in the material is perpendicular to the Z axis (parallel to the rolling plane) and the index [uvw] of the crystal orientation parallel to the X axis (perpendicular to the rolling plane) hkl) Shown in the form of [uvw]. Also, for equivalent orientations under the cubic symmetry of copper alloys, such as (1 32) [6-4 3] and (2 3 1) [3-4 6] etc. Use the parenthesis symbol to indicate, {hkl} <uvw>. With the above notation, each orientation is expressed as follows.

As typical crystal orientations found in FCC metals, components represented by the following indices are common.
Cube orientation {001} <100>
Rotated-Cube Orientation {012} <100>
Goss azimuth {011} <100>
Rotated-Goss azimuth {011} <011>
Brass orientation {011} <211>
Copper azimuth {112} <111>
S direction {123} <634>
P direction {011} <111>

In the texture of a normal copper alloy sheet, the elastic behavior of the sheet changes as the composition ratio of these crystal planes changes.

In copper alloys, it is known that the orientation as described above appears, but as a result of intensive studies, increasing the area ratio of the (100) plane facing RD decreases the Young's modulus and bending deflection coefficient. I found it to be particularly effective. The above-mentioned Cube orientation, Rotated-Cube orientation, Goss orientation, etc. are included in the orientation component in which the (100) plane faces RD. The texture of the conventional Corson-based high strength copper alloy sheet, when manufactured by a known method, S orientation {123} <634> other than Cube orientation {001} <100>, Brass orientation {011} <211 The inventors of the present invention have confirmed that the > main component, the proportion of Cube orientation decreases, and the Young's modulus and bending deflection coefficient increase. In particular, when there were many (111) planes in the RD direction, it was confirmed that Young's modulus and bending deflection coefficient became high.

Therefore, in the texture of the copper alloy sheet of the present invention, among the crystal faces directed to RD, the angle between two vectors of the plane orientation {eg the normal to the (100) plane} and RD is 10 ° or less The area ratio of the crystal plane is preferably 30% or more, and thereby, it is possible to have a texture with a low Young's modulus and a low flexural deflection coefficient. The area ratio of the (100) plane facing the RD is more preferably 40% or more, more preferably 50% or more. Thus, by increasing the area ratio of the (100) plane facing RD, the Young's modulus can be 110 GPa or less, and the bending deflection coefficient can be 105 GPa or less. This is because the area ratio of the crystal face toward RD having a low Young's modulus and a low flexural modulus (100) increases. In addition, the Young's modulus can be reduced by decreasing the area ratio of the crystal face to the RD of (111) having a high Young's modulus and a high bending deflection coefficient. The area ratio of the (111) plane facing RD is preferably 15% or less, more preferably 10% or less.

The measurement of the area ratio of the (100) plane facing RD in the texture of the copper alloy sheet can be obtained by analyzing the electron microscopic structure by SEM using EBSD. Here, a range including 400 or more crystal grains (for example, with respect to a sample area of 800 μm square) was scanned at 1 μm steps to analyze the orientation. In addition, since these azimuth | direction distribution is changing to the plate | board thickness direction, it is more preferable to obtain | require by taking the average for several points arbitrarily in the plate | board thickness direction.

The SEM-EBSD method is an abbreviation of Scanning Electron Microscopy-Electron Back Scattered Diffraction Pattern method. That is, the individual crystal grains appearing on the SEM screen are irradiated with an electron beam, and the individual crystal orientations are identified from the diffracted electrons.

The crystal orientation display method in this specification takes the rectangular coordinate system of the rolling direction (RD) of the material as the X axis, the sheet width direction (TD) as the Y axis, and the rolling normal direction (ND) as the Z axis. The ratio of the area where the (100) plane faces is defined by the area ratio. Calculate the angle between the normal to (100) plane of each crystal grain in the measurement area and the angle formed by the two vectors of RD, sum the areas for those with an atomic face whose angle is 10 ° or less, and calculate the sum The value obtained by dividing by the total measurement area was taken as the area ratio (%) of the region having an atomic plane in which the angle formed by the normal to the (100) plane and the RD is 10 ° or less.
That is, in the present invention, with regard to the accumulation of atomic planes directed to the rolling direction (RD) of a rolled sheet, a region having an atomic plane in which the angle between the normal to the (100) plane and the RD is 10 ° or less Regarding accumulation of atomic planes facing the rolling direction (RD) of the rolled sheet, that is, facing the RD, the (100) plane itself with the rolling direction (RD) of the rolled sheet being the ideal direction as a normal The region (the sum of these areas) is a combination of each of the atomic planes in which the angle between the normal of R and the angle formed by RD is 10 ° or less. Hereinafter, these surfaces are combined to be referred to as a (100) surface facing the RD, and these regions are simply referred to as a region of an atomic surface where the (100) surface faces the RD. The same applies to the (111) plane facing RD.

In the EBSD measurement, in order to obtain a clear Kikuchi line diffraction image, it is preferable to perform the measurement after mirror polishing of the substrate surface using abrasive grains of colloidal silica after mechanical polishing. Moreover, measurement shall be performed from the ND direction of the plate surface unless otherwise specified.
Here, the features of the EBSD measurement will be described as a comparison with the X-ray diffraction measurement. The first point mentioned is the crystal orientation which can not be measured by X-ray diffraction measurement, which is the S orientation and the BR orientation. In other words, by adopting EBSD, for the first time, information on S orientation and BR orientation can be obtained, and the relationship between the specified alloy structure and action can be clarified. The second point is that X-ray diffraction measures the amount of crystal orientation included in ± 0.5 ° of ND // {hkl}. On the other hand, EBSD measures the amount of crystal orientation included in ± 10 ° from the orientation. Therefore, EBSD measurement provides an order of magnitude comprehensive information on the alloy structure comprehensively, and it becomes clear that it is difficult to identify the entire alloy material by X-ray diffraction. As described above, the information obtained by EBSD measurement and X-ray diffraction measurement differs in the content and nature thereof. In addition, unless otherwise indicated in this specification, the result of EBSD is performed to the ND direction of a copper alloy plate material.

(Manufacturing conditions)
Next, preferable manufacturing conditions of the copper alloy material of the present invention will be described below. The copper alloy material of the present invention is, for example, each step of casting, hot rolling, slow cooling, cold rolling 1, intermediate annealing, cold rolling 2, solution heat treatment, aging heat treatment, finish cold rolling, low temperature annealing, Manufactured through. The copper alloy material of the present invention can be manufactured with almost the same equipment as a conventional Corson alloy. In order to obtain predetermined physical properties and further a texture, it is necessary to appropriately adjust the manufacturing conditions of each process. In this respect, the copper alloy material of the present invention is manufactured by performing processing after hot rolling or at least one of cold rolling and intermediate annealing before solution treatment under predetermined conditions. Can.

The casting is performed by casting a molten copper alloy having its components adjusted to the above composition range. Then, the ingot is chamfered, heated or homogenized at 800 to 1000 ° C., and hot rolled. Here, in the case of a conventional method for producing a Corson-based alloy, the steel is rapidly quenched by a method such as water cooling immediately after hot rolling. On the other hand, in the first preferred embodiment of the method for producing the copper alloy material of the present invention, the quenching is not carried out in order to increase the (100) surface facing RD after the hot rolling, and it is characterized by slow cooling. I assume. The cooling rate at the time of slow cooling is preferably 5 K / s or less. The direction in which the (100) plane faces RD has a recovery phenomenon at low temperature as compared with other directions, and the area ratio of the direction in which the (100) face faces RD can be increased in the hot-rolled structure. When the proportion of grains having an orientation in which the face of (100) faces in RD in this hot rolled structure is increased, the area ratio of the orientation in which the face of (100) faces in RD in the subsequent solutionizing step It can be enhanced. Since a change in structure does not occur if the temperature upon cooling is less than 350 ° C., after the temperature is cooled to less than 350 ° C., quenching may be performed by a method such as water cooling to reduce production time.

Next, after the hot rolling and cooling are completed, the surface is cut and cold rolling 1 is performed. If the rolling reduction ratio of the cold rolling 1 is too low, even if the final product is manufactured, the brass orientation and the S orientation develop, and it becomes difficult to increase the (100) area ratio. Therefore, it is preferable that the rolling reduction rate of the cold rolling 1 be 70% or more.

After cold rolling 1, intermediate annealing is applied at 300 to 800 ° C. for 5 seconds to 2 hours. After the intermediate annealing, cold rolling 2 with a rolling reduction of 3 to 60% is performed. Repeating the intermediate annealing and the cold rolling 2 can further increase the area ratio of the (100) plane facing RD. Therefore, in the second preferred embodiment of the method for producing a copper alloy material of the present invention, the intermediate annealing and the cold rolling 2 are repeated twice or more.

The solution treatment is performed at 600 to 1000 ° C. for 5 seconds to 300 seconds. Since the necessary temperature conditions change depending on the concentrations of Ni and Co, it is necessary to select an appropriate temperature condition according to the Ni and Co concentrations. If the solution treatment temperature is too low, the strength is insufficient in the aging treatment step, and if the solution treatment temperature is too high, the material softens more than necessary and the shape control becomes difficult, which is not preferable.

The aging treatment is performed at 400 to 600 ° C. for 0.5 to 8 hours. Since the necessary temperature conditions change depending on the concentrations of Ni and Co, it is necessary to select an appropriate temperature condition according to the Ni and Co concentrations. When the temperature of the aging treatment is too low, the amount of aging precipitation decreases and the strength is insufficient. In addition, when the temperature of the aging treatment is too high, the precipitates become coarse and the strength decreases.

It is preferable to set the working ratio of finish cold rolling after solution treatment to 50% or less. Thus, by appropriately controlling the processing rate, the crystal grains having (100) orientation such as Cube orientation can be prevented from rotating in orientation to Brass, S, Copper orientation, etc., and the physical properties of the obtained copper alloy material In addition, it is possible to achieve the desirable state of the texture.

Low temperature annealing is performed at 300 to 700 ° C. for 10 seconds to 2 hours. This annealing can improve the stress relaxation resistance and the spring limit value required for the connector material.

In a more preferable production method for obtaining the copper alloy material of the present invention, the steps of both the first embodiment and the second embodiment are performed, that is, until the temperature range of at least less than 350 ° C. after hot rolling. Is not rapid cooling but gradual cooling (preferably with a cooling rate of 5 K / sec or less), and intermediate annealing and cold rolling 2 are repeated twice or more.

In order to ensure that the copper alloy material of the present invention manufactured by the above method has predetermined properties, it is verified by EBSD analysis whether the physical properties of the copper alloy material and the texture are within the predetermined range. do it.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

The copper alloy of each composition shown in the following Tables 1 and 2 was cast to manufacture a copper alloy plate, and each characteristic such as strength (0.2% proof stress), conductivity, Young's modulus was evaluated.

First, casting was performed by a DC (Direct Chill) method to obtain an ingot having a thickness of 30 mm, a width of 100 mm, and a length of 150 mm. Next, these ingots were heated to 950 ° C., held at this temperature for 1 hour, hot-rolled to a thickness of 14 mm, gradually cooled at a cooling rate of 1 K / s, and cooled to 300 ° C. or less. Subsequently, the both surfaces were subjected to 2 mm face milling to remove the oxide film, and then cold rolling 1 with a rolling ratio of 90 to 95% was applied. Thereafter, cold rolling 2 was performed at an intermediate annealing temperature of 350 to 700 ° C. for 30 minutes and a cold rolling ratio of 10 to 30%. Thereafter, solution treatment was performed at 700 to 950 ° C. under various conditions for 5 seconds to 10 minutes, and immediately cooled at a cooling rate of 15 ° C./second or more. Next, in an inert gas atmosphere, aging was performed at 400 to 600 ° C. for 2 hours, and then finish rolling was performed at a rolling reduction of 50% or less, and the final plate thickness was made 0.15 mm. After finish rolling, a low temperature annealing treatment was performed at 400 ° C. for 30 seconds to obtain a copper alloy sheet of each alloy composition.

With respect to the copper alloy sheet thus produced, in each of the examples, the samples cut out from the copper alloy sheet subjected to the low temperature annealing treatment were used, and the following tests and evaluations were carried out.

(1) Area ratio of crystal orientation grain About the structure | tissue of a copper alloy plate sample, the area ratio of the (100) plane which faces RD was calculated | required as follows.
That is, when an EBSD analysis is performed from the RD direction, a crystal grain having a crystal orientation whose angle is 10 ° or less with respect to an angle that the normal to the (100) plane makes with RD is a grain having the (100) plane facing the RD. . Specifically, the area ratio of the (100) plane facing the RD was determined as follows. According to the EBSD method, measurement was performed under the condition of a scan step of 1 μm in a sample measurement area of about 800 μm. The measurement area was adjusted on the basis of including 400 or more crystal grains. As described above, the sum of the areas of the (100) planes of the crystal grains having the normal to the (100) plane such that the angle between the plate material sample and the rolling direction (RD) makes 10 ° or less is determined The area ratio (%) of the (100) plane facing RD was obtained by dividing the sum of the areas by the total measurement area. Here, the crystal grains having the above-mentioned angle of 10 ° or less were the same orientation grains.
In addition, the area ratio (%) of the (111) plane facing RD was similarly determined.
(2) 0.2% proof stress The 0.2% proof stress was determined in accordance with JIS Z 2241 by cutting a No. 5 test piece described in JIS Z 2201 from each test material. The 0.2% proof stress is shown by rounding to an integral multiple of 5 MPa.
(3) Conductivity The conductivity was determined in accordance with JIS H 0505.
(4) Young's Modulus The Young's modulus was measured using a strain gauge with a tensile tester using a strip-shaped test piece having a width of 20 to 30 mm, and a Young's modulus in a strength region of 0.2% or less of the proof stress. The test pieces were collected parallel to the rolling direction.
(5) Bending deflection coefficient The bending deflection coefficient was measured in accordance with the Japan Copper and Brass Association (JCBA) technical standard. The width of the test piece was 10 mm and the length was 15 mm, and a bending test of the cantilever was conducted, and the deflection coefficient was measured from the load and the deflection displacement.
These results are shown in Tables 1 and 2.

Table 1 shows an example of the present invention. In Examples 1 to 29, the texture was within the preferable range of the present invention, and all of 0.2% proof stress, conductivity, Young's modulus and bending deflection coefficient were excellent.

Table 2 shows a comparative example to the present invention. Comparative Examples 1, 2 and 5 were inferior in 0.2% proof stress because the content of Ni and / or Co and the content of Si were too smaller than the range of the present invention. In Comparative Examples 3, 4, 6, and 7, since the content of Ni and / or Co was too high, cracking occurred during hot rolling, and the production was stopped. In Comparative Example 8, the conductivity was inferior because the concentration of Si was too high.
The following comparative example is an example using the same ingot as Example 2.
Comparative Example 2-2 is an example in which water cooling was immediately performed after hot rolling, intermediate annealing and cold rolling 2 were omitted, and the others were prepared in the same manner as in Example 2, but the (100) plane is suitable for RD The area ratio of (111) was low, and the area ratio of (111) plane was high, and the Young's modulus and bending deflection coefficient were higher than those of the inventive example.
Comparative Example 2-3 is an example produced similarly to Example 2 except that water cooling is immediately performed after hot rolling, but the area ratio of the (100) plane facing RD is low, and the Young's modulus is an example of the present invention It was higher than that.

Table 3 shows another embodiment.

In Examples 10-2, 18-2 and 25-2 of Table 3, the same ingot as that of Examples 10, 18 and 25 of Table 1 was used, and water cooling was immediately performed after hot rolling, and intermediate annealing and cooling were performed. This is an example in which the inter-rolling 2 was repeated twice, and the others were produced in the same manner as in each example of Table 1 and the respective characteristics were similarly evaluated. The area ratio of the (100) plane facing RD is within the preferable range of the present invention, and the strength, the conductivity, the Young's modulus, and the bending deflection coefficient are excellent.
In Examples 10-3, 18-3, and 25-3, using the same ingots as those of Examples 10, 18, and 25 in Table 1, intermediate annealing and cold rolling 2 are repeated twice, and the others are It is the example which produced similarly to each Example of Table 1, and evaluated each characteristic similarly. These had a particularly high area ratio of (100) face toward RD, a Young's modulus was particularly low at 100 GPa or less, a bending deflection coefficient was particularly low at 90 GPa, and 0.2% proof stress and conductivity were excellent. .

Then, in order to clarify the difference with the copper alloy plate material concerning the present invention about the copper alloy plate material manufactured according to the conventional manufacturing conditions, a copper alloy plate material is produced under the conditions, and evaluation of the same characteristic items as above Did. The working ratio was adjusted so that the thickness of each plate was the same as that in the above-mentioned embodiment unless otherwise specified.

Comparative Example 101 Condition of JP 2009-007666 A metal element similar to that of the invention example 1-1 was blended, and an alloy composed of Cu and incidental impurities with the balance was melted in a high frequency melting furnace, This was cast at a cooling rate of 0.1 to 100 ° C./sec to obtain an ingot. After holding this at 900 ° C. to 1020 ° C. for 3 minutes to 10 hours, it was hot-worked and then water-quenched to carry out facing for oxide scale removal. In the subsequent steps, a copper alloy c01 was produced by the treatment of steps A-3 and B-3 described below.
The manufacturing process includes one or more solution heat treatment, in which the steps are classified before and after the last solution heat treatment, and the steps up to intermediate solution treatment are designated as A-3, It was designated as B-3 step in the step after intermediate solution treatment.

Step A-3: Cold work with a reduction in area of 20% or more, heat treatment for 5 minutes to 10 hours at 350 to 750 ° C., cold work with a reduction in area of 5 to 50%, 800 A solution heat treatment is performed at about 1000 ° C. for 5 seconds to 30 minutes.
Step B-3: Cold work with a reduction in area of 50% or less, heat treatment at 400 to 700 ° C. for 5 minutes to 10 hours, cold work with a reduction in area of 30% or less, Apply temper annealing at 550 ° C. for 5 seconds to 10 hours.

The obtained test body c01 differs from the above example in terms of the presence or absence of slow cooling to 350 ° C. after hot rolling with respect to manufacturing conditions, and the area ratio of the (111) plane facing RD is high, Young's modulus and bending The deflection coefficient did not meet the required characteristics.

Comparative Example 102 Condition of Japanese Patent Application Laid-Open No. 2006-283059 The copper alloy having the composition of the above-mentioned inventive example 1-1 was dissolved in the atmosphere with an electric furnace under charcoal coating, and the possibility of casting was judged. . The molten ingot was hot-rolled and finished to a thickness of 15 mm. Subsequently, cold rolling and heat treatment (cold rolling 1 → solution annealing continuous annealing → cold rolling 2 → aging treatment → cold rolling 3 → short time annealing) are applied to the hot-rolled material, and a predetermined thickness is obtained. Copper alloy sheet (c02) was produced.

The obtained test body c02 is different from the above-mentioned Example 1 in the presence or absence of slow cooling to 350 ° C. after hot rolling and the presence or absence of intermediate annealing before solution treatment and cold rolling with respect to production conditions. The area ratio of the (111) plane facing to was high, and the result was not satisfied with the Young's modulus and bending deflection coefficient.

Comparative Example 103 Condition of JP-A-2006-152392 The alloy having the composition of the above-mentioned invention example 1-1 is melted under charcoal covering in the atmosphere in a krypton furnace and cast in a cast iron book mold. Thus, an ingot having a thickness of 50 mm, a width of 75 mm and a length of 180 mm was obtained. Then, after the surface of the ingot was chamfered, it was hot rolled at a temperature of 950 ° C. to a thickness of 15 mm, and quenched into water from a temperature of 750 ° C. or more. Next, after removing the oxide scale, cold rolling was performed to obtain a plate having a predetermined thickness.

Then, after performing the solution treatment which heats at temperature for 20 seconds using a salt bath furnace, after rapidly_cooling | quenching in water, it was made into the cold-rolled sheet of each thickness by finish cold rolling of the latter half. Under the present circumstances, as shown below, the working ratio (%) of these cold rollings was changed variously, and it was set as the cold rolled sheet (c03). These cold rolled sheets were subjected to an aging treatment while changing the temperature (° C.) and the time (hr) variously as shown below.

Cold working rate: 95%
Solution treatment temperature: 900 ° C
Artificial age hardening processing temperature × time: 450 ° C × 4 hours Thickness: 0.6 mm

The obtained test body c03 is different from the above-mentioned Example 1 in the presence or absence of slow cooling to 350 ° C. after hot rolling and the presence or absence of intermediate annealing before solution treatment and cold rolling with respect to production conditions. The area ratio of the (111) plane facing to was high, and the result was not satisfied with the Young's modulus and bending deflection coefficient.

Comparative Example 104 Condition of JP-A-2008-223136 The copper alloy shown in Example 1 was melted and cast using a vertical continuous casting machine. A sample of 50 mm in thickness was cut out from the obtained slab (180 mm in thickness), heated to 950 ° C., extracted, and hot rolling was started. At this time, a pass schedule was set so that the rolling reduction in a temperature range of 950 to 700 ° C. would be 60% or more and rolling could be performed in a temperature range of less than 700 ° C. The final pass temperature for hot rolling is between 600 and 400 ° C. The total hot-rolling rate from the slab is about 90%. After hot rolling, the surface oxide layer was removed by mechanical polishing (face grinding).

Next, after cold rolling, it was subjected to solution treatment. The temperature change at the time of solution treatment was monitored by a thermocouple attached to the sample surface, and the temperature rising time from 100 ° C. to 700 ° C. in the temperature rising process was determined. The final temperature is adjusted within the range of 700 to 850 ° C according to the alloy composition so that the average grain size after solution treatment (twin boundaries are not regarded as grain boundaries) is 10 to 60 μm, The holding time in the temperature range of 850 ° C. was adjusted in the range of 10 sec to 10 mim. Subsequently, the plate material after the solution treatment was subjected to intermediate cold rolling at a rolling ratio and then subjected to an aging treatment. The aging treatment temperature was set to 450 ° C., and the aging time was adjusted to a time at which the hardness peaked at 450 ° C. aging depending on the alloy composition. The optimum solution treatment conditions and aging treatment time are grasped by preliminary experiments according to such alloy composition. Then, finish cold rolling was performed at a rolling ratio. The final cold-rolled product was further subjected to low-temperature annealing for 5 minutes in a 400 ° C. furnace. Thus, the test material c04 was obtained. In addition, it was chamfered on the way as needed, and the plate thickness of the test material was equalized to 0.2 mm. The main production conditions are described below.

[Conditions of JP-A-2008-223136 Example 1]
Hot rolling reduction at less than 700 ° C to 400 ° C: 56% (1 pass)
Before solution treatment Cold rolling ratio: 92%
Intermediate cold rolling Cold rolling ratio: 20%
Finish cold rolling Cold rolling ratio: 30%
Temperature rising time from 100 ° C to 700 ° C: 10 seconds

The obtained test body c04 is different from the above-mentioned Example 1 in the presence or absence of slow cooling up to 350 ° C. after hot rolling and the presence or absence of intermediate annealing before solution treatment and cold rolling with respect to production conditions. The area ratio of the (111) plane facing to was high, and the result was not satisfied with the Young's modulus and bending deflection coefficient.

Claims

Containing an alloy composition containing 0.5 to 5.0% by mass in total of one or both of Ni and Co, 0.2 to 1.5% by mass of Si, and the balance being Cu and unavoidable impurities A copper alloy sheet material for electric and electronic parts characterized in that the 0.2% proof stress in the rolling direction is 500 MPa or more, the conductivity is 30% IACS or more, the Young's modulus is 110 GPa or less, and the bending deflection coefficient is 105 GPa or less.
The copper alloy for electric and electronic parts according to claim 1, wherein the area ratio of the (100) plane facing in the rolling direction obtained by analyzing using EBSD of the copper alloy sheet is 30% or more. Plate material.
3. The electric / electronic component according to claim 1, wherein the area ratio of the (111) plane directed in the rolling direction obtained by analyzing the copper alloy sheet using EBSD is 15% or less. Copper alloy sheet material.
The copper alloy sheet according to any one of claims 1 to 3, further comprising 0.05 to 0.5 mass% of Cr.
5. The method according to claim 1, further comprising 0.01 to 1.0% by mass in total of one or more selected from the group consisting of Zn, Sn, Mg, Ag, Mn and Zr. The copper alloy sheet material for electric and electronic parts according to any one of the items.
The area ratio of the (111) plane facing in the rolling direction obtained by analyzing the EBSD of the copper alloy sheet material is 15% or less, The area ratio according to any one of claims 1 to 5, Copper alloy sheet for electrical and electronic parts.
The copper alloy sheet material for electric and electronic parts according to any one of claims 1 to 6, which is a material for a connector.
A connector comprising the copper alloy sheet material for electric and electronic parts according to any one of claims 1 to 6.
A method of producing a copper alloy sheet for electric and electronic parts according to any one of claims 1 to 6, wherein the copper alloy giving the alloy composition is cast, hot rolled, cold rolled 1, an intermediate Annealing, cold rolling 2, solution heat treatment, aging heat treatment, finish cold rolling, low temperature annealing are applied in this order, and at least one or both of the following [1] and [2] are further performed The manufacturing method of the copper alloy board material for electric and electronic parts characterized by the above.
[1] Step of gradually cooling to 350 ° C. after the above hot rolling [2] Step of repeating the intermediate annealing and the cold rolling 2 twice or more