Copper alloy and electronic component

Abstract

A copper alloy according to the present disclosure contains 1.5% by mass to 4.6% by mass inclusive of Ni, 0.10% by mass to 0.80% by mass inclusive of Co, 0.10% by mass to 1.3% by mass inclusive of Si, and 0.010% by mass to 0.10% by mass inclusive of Cr, with the balance made up of Cu and unavoidable impurities, and has a volume fraction of the cube orientation of 30.0% or more.

Description

Copper alloy and electronic component

[0001] This specification describes a copper alloy and an electronic component.

[0002] A copper alloy in which intermetallic compounds such as Ni—Si, Co—Si, Ni—Co—Si, etc. are precipitated in a Cu matrix can be called a Colson alloy. Since the Colson alloy has high strength and conductivity, it may be used for parts made of copper alloy among electronic components, for example, lead frames of semiconductor packages, various connection terminals, and the like. As a technology related to this type of copper alloy, for example, there is one described in Patent Document 1.

[0003] Patent Document 1 has an object of “providing a copper alloy sheet suitable for lead frames, connectors, terminal materials, etc. for electric and electronic equipment, connectors and terminal materials for in-vehicle use in automobiles, relays, switches, etc., which are excellent in bendability, have excellent strength, and have little anisotropy between the rolling parallel direction and the rolling perpendicular direction of each property”, and “contains Ni of 1.0% by mass or more and 5.0% by mass or less, Si of 0.1% by mass or more and 2.0% by mass or less, and the balance is composed of copper and inevitable impurities, and in the crystal orientation analysis by the electron backscatter diffraction method, the area ratio of crystal grains having an orientation with a deviation of 15° or less from the cube orientation {001}<100> is 5% or more and 50% or less, and crystal grains having an orientation with a deviation of 15° or less from the cube orientation {001}<100> are dispersed within 60 μm square and there are 40 or more and 100 or less of them” is described.

[0004] International Publication No. 2012 / 150702

[0005] With the high functionality and space saving of electronic devices, the shapes of the electronic components used therein are becoming more complex. Therefore, good bendability is required for the materials (for example, copper alloy) used for electronic components. [[ID=!7]]

[0006] The object of this specification is to provide a copper alloy and an electronic component with improved bendability.

[0007] The copper alloy described in this specification contains 1.5% by mass or more and 4.6% by mass or less of Ni, 0.10% by mass or more and 0.80% by mass or less of Co, 0.10% by mass or more and 1.3% by mass or less of Si, and 0.010% by mass or more and 0.10% by mass or less of Cr, with the remainder being Cu and unavoidable impurities, and the volume fraction in the cube orientation is 30.0% or more.

[0008] The electronic components described in this specification include the above-mentioned copper alloy.

[0009] The above copper alloy has been improved in terms of bendability.

[0010] This graph shows an example of the relationship between X in equation (1), described later, for the semi-finished product after solution treatment, and the volume fraction of the copper alloy in the Cube orientation.

[0011] The embodiments of the copper alloy and electronic components described above will be explained in detail below.

[0012] In this disclosure, "A to B" means "greater than or equal to A and less than or equal to B," where A and B represent numerical values.

[0013] One embodiment of the copper alloy contains 1.5% by mass or more and 4.6% by mass or less of Ni, 0.10% by mass or more and 0.80% by mass or less of Co, 0.10% by mass or more and 1.3% by mass or less of Si, and 0.010% by mass or more and 0.10% by mass or less of Cr, with the remainder being Cu and unavoidable impurities, and the volume fraction in the cube orientation is 30.0% or more.

[0014] The above copper alloy has good bendability.

[0015] (Composition) The Ni content of the copper alloy is 1.5% by mass or more and 4.6% by mass or less. Preferably, the Ni content is 2.0% by mass or more and 4.6% by mass or less, more preferably 2.3% by mass or more and 4.6% by mass or less, and even more preferably 3.0% by mass or more and 4.3% by mass or less.

[0016] The Co content of the copper alloy is 0.10% by mass or more and 0.80% by mass or less. Preferably, the Co content is 0.13% by mass or more and 0.60% by mass or less, and more preferably 0.18% by mass or more and 0.50% by mass or less.

[0017] If the Ni content is less than 1.5 mass%, the desired strength cannot be obtained. If the Co content is less than 0.10 mass%, the desired strength and conductivity cannot be obtained. If the Ni content exceeds 4.6 mass%, or the Co content exceeds 0.80 mass%, even if high strength is obtained, it will lead to a decrease in conductivity.

[0018] Based on the above, the total content of Ni and Co is 1.60% by mass or more and 5.40% by mass or less. In order to obtain the desired strength and conductivity, the total content of Ni and Co may be 2.50% by mass or more and 4.50% by mass or less, or 3.50% by mass or more and 4.00% by mass or less.

[0019] The Si content of the copper alloy is 0.10% by mass or more and 1.3% by mass or less. Preferably, the Si content is 0.30% by mass or more and 1.3% by mass or less, more preferably 0.60% by mass or more and 1.3% by mass or less, and even more preferably 0.60% by mass or more and 1.0% by mass or less.

[0020] Ni-Co-Si precipitates formed by Ni, Co, and Si in copper alloys are considered to be mainly (Ni + Co)Si intermetallic compounds. However, not all Ni, Co, and Si in copper alloys become precipitates during the manufacturing process; some may exist in a solid solution state within the Cu matrix. While solid solution-state Ni, Co, and Si can slightly improve the strength of the copper alloy, their effect is smaller compared to the precipitated state, and they can also reduce electrical conductivity. Therefore, it is preferable to bring the ratio of Ni, Co, and Si content close to the composition ratio of (Ni + Co)Si. Specifically, the total mass ratio of Ni and Co to Si may be 3.4 or more and 5.4 or less, and preferably 3.8 or more and 5.0 or less.

[0021] The Cr content of the copper alloy is 0.010% by mass or more and 0.10% by mass or less. Preferably, the Cr content is 0.020% by mass or more and 0.070% by mass or less, and more preferably 0.040% by mass or more and 0.060% by mass or less.

[0022] If the Cr content is less than 0.010% by mass, the desired strength cannot be obtained. If the Cr content exceeds 0.10% by mass, the Cr forms compounds with other components, making it difficult to form the desired Ni-Co-Si precipitate. As a result, the desired strength cannot be obtained.

[0023] In addition to the elements mentioned above, copper alloys may further contain one or more elements selected from the group consisting of Mg, Fe, P, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo, and Mn (hereinafter referred to as "additive elements") in a total amount of 0.010% by mass or more and 5.0% by mass or less. This can improve the strength, heat resistance, stress relaxation resistance, etc., of the copper alloy while suppressing a decrease in conductivity. The total content of additive elements is preferably 0.030% by mass or more and 3.0% by mass or less, and more preferably 0.050% by mass or more and 1.0% by mass or less.

[0024] The remainder of the copper alloy, other than the elements mentioned above, consists of Cu and unavoidable impurities. Unavoidable impurities refer to impurity elements that cannot be avoided during manufacturing. The total content of unavoidable impurities can be below a detection limit, such as 0.015% by mass, and preferably 0% (undetectable).

[0025] When measuring the composition of copper alloys, the Ni content is measured using the copper-separated dimethylglyoxime gravimetric method (JIS H1056:2003), and the Si content is measured using the silicon dioxide gravimetric method (JIS H1061:2006). For the measurement of other elements and impurity elements, ICP emission spectrometry can be used. Analysis of other elements is performed according to the internal standard method, using Y (yttrium) as the internal standard. Elements other than Y can be selected as the internal standard. For ICP emission spectrometry, an ICP emission spectrometer (ICP-OES) SPS3100 manufactured by Hitachi High-Tech Science Corporation or an equivalent instrument is used. The copper alloy sample is dissolved in a mixed acid containing hydrochloric acid and nitric acid (hydrochloric acid, nitric acid, and water in a volume ratio of 2:1:2), and the resulting solution is diluted before use. The composition of the copper alloy may also be measured using X-ray fluorescence analysis. For the X-ray fluorescence analysis, a Simultix 14 manufactured by Rigaku Corporation or a substantially equivalent instrument can be used. Here, the surface of the copper alloy can be prepared for analysis by cutting or mechanical polishing so that the maximum surface roughness Rz (JIS B0601:2013) is 6.3 μm or less. When taking a sample for X-ray fluorescence analysis from molten metal during melting and casting, the metal is cast into a shape of approximately 30-40 mm in diameter and 50-80 mm in thickness, then cut to a thickness of approximately 10-20 mm, and the cut surface is used as the analysis surface. X-ray fluorescence analysis is performed in accordance with JIS K0119:2008 and measured using the wavelength dispersion method.

[0026] (Cube volume fraction) The volume fraction of the Cube orientation of the copper alloy of this embodiment, when measured by the method described later, is 30.0% or more. This gives the copper alloy good bendability.

[0027] The volume fraction of the copper alloy in the cube orientation of this embodiment may preferably be 35.0% or more, and more preferably 40.0% or more. The upper limit of the volume fraction of the copper alloy in the cube orientation of this embodiment is not particularly limited, but may be 70.0% or less, 50.0% or less, or 45.0% or less. The cube volume fraction of the copper alloy of this disclosure may, for example, be 35.0% or more and 50.0% or less, or 40.0% or more and 45.0% or less.

[0028] The Cube orientation refers to the orientation of a crystal grain in which the {001} plane is parallel to the rolling plane and the <001> direction is parallel to the rolling direction (RD direction). The rolling direction refers to the direction in which the object being rolled passes between a pair of work rolls.

[0029] By measuring the surface of a copper alloy using X-ray diffraction, the volume fraction in the cube orientation can be quantitatively determined from the resulting pole figure using the ODF (Crystallite Orientation Distribution Function) method. The measurement conditions are as follows: <Equipment Configuration> ・Incident X-ray source: CoKα (1.789 Å) ・Goniometer length: 300 mm ・Optical system: Focused method ・Incident solar slit: 2.5° ・Incident slit: 1 / 2° ・Longitudinal limiting slit: 2 mm ・Attachment: ASC-48 ・Receiving slit 1: 10 mm ・Receiving solar slit: 2.5° ・Receiving slit 2: 9.975 mm ・Attenuator: Automatic ・Detector: 1D detector D / teX Ultra 250 (1D mode) ・Monochromatization: Multilayer mirror ・Kβ filter: 1D filter for Co (Fe 0.019 mm) <Measurement Method> ・Tube voltage: 40 kV ・Tube current: 25 mA ・α axis: Mode: 0D step, Range: 15-90°, Step: 5°・β axis: Mode: 0D continuous, Range: 0-360°, Step: 5° ・Reflection method: Schulz ・Measurement angle: (111): 50.8°, (200): 59.4°, (220): 89.0° ・Counting speed: 600° / min ・γ fluctuation: None <Background measurement conditions> ・Measurement point: 1 point measurement ・2θ angle: (111): 47.8°, (200): 56.4°, (220): 86.0 ・α axis: Mode: 0D step, 2θ angle: 47.8°, Step: 5° ・β axis: Mode: 0D continuous, Range: 0-360°, Step: 5° ・Counting speed: 600° / min <Analysis conditions> OFD calculation ・Calculation method: Component model ・Component property fraction: Value: 0.44, Minimum: 0, Maximum: 1, Fitting included FMHM (°) ... Value: 16.66, Minimum: 1, Maximum: 40, Fitting included FMHM 2 (°) ... Value: 34.75, Minimum: 1, Maximum: 40, Fitting included FMHM 3 (°) ... Value: 6.73, Minimum: 1, Maximum: 40, Fitting included φ1 (°) ... Value: 0, Minimum: 0, Maximum: 90, No fitting Φ (°) ... Value: 0, Minimum: 0, Maximum: 90, No fittingφ² (°) ... Value: 0, Minimum: 0, Maximum: 90, No fitting αd (°) ... Value: 21.18, Minimum: 0, Maximum: 180, Fitted βd (°) ... Value: 164.88, Minimum: 0, Maximum: 180, Fitted γd (°) ... Value: 77.23, Minimum: 0, Maximum: 180, Fitted Sample symmetry: 1 / 4 symmetry α analysis start angle: 0.00° α analysis end angle: 90.00° Parameters Crystal phase: Cu Minimization algorithm: Genetic algorithm Population: 50 Individuals: 100 Target x 2 : 0.1 • Weight: 50.00 • Crossover: 50.00 As the X-ray diffractometer, a SmartLab manufactured by Rigaku Corporation or a substantially equivalent device can be used.

[0030] (Tensile Strength) The tensile strength of the copper alloy in the direction parallel to the rolling direction may be 850 MPa or higher, 900 MPa or higher, or 972 MPa or higher. With such high strength, deformation of even thin-walled pins of connecting terminals is effectively suppressed. The upper limit of the tensile strength of the copper alloy in the direction parallel to the rolling direction is not particularly limited, but for example, it may be 1100 MPa or lower, 1050 MPa or lower, or 1010 MPa or lower.

[0031] The tensile strength of copper alloys is measured using a tensile testing machine in accordance with JIS Z2241:2011, in a direction parallel to the rolling direction. Specifically, a JIS 13B test specimen is taken from the copper alloy using a press so that the tensile direction is parallel to the rolling direction. The conditions for the tensile test are a specimen width of 12.5 mm, a measurement temperature of room temperature (15-35°C), a tensile speed (crosshead displacement rate) of 5 mm / min, and a gauge length of 50 mm. Two test specimens are tested, and the average of the two measured values ​​obtained from each specimen is taken as the tensile strength.

[0032] (0.2% yield strength) The 0.2% yield strength of the copper alloy in the direction parallel to the rolling direction may be 850 MPa or higher, 900 MPa or higher, or 925 MPa or higher. With such high strength, deformation is effectively suppressed even in thin-walled pins of connecting terminals. The upper limit of the 0.2% yield strength of the copper alloy in the direction parallel to the rolling direction is not particularly limited, but may be, for example, 1100 MPa or lower, 1050 MPa or lower, 1000 MPa or lower, or 960 MPa or lower.

[0033] The 0.2% yield strength of copper alloys is measured using a tensile testing machine in accordance with JIS Z2241:2011, in a direction parallel to the rolling direction (offset method, 0.2%). Specifically, test specimens are prepared using the same method as described above for tensile strength. The test is also performed under the same conditions as described above for tensile strength.

[0034] (Electrical conductivity) The electrical conductivity of the copper alloy in the direction parallel to the rolling direction may be 35.0% IACS or higher, preferably 37.6% IACS or higher. This allows the copper alloy to be used well in electronic components. The upper limit of the electrical conductivity of the copper alloy in the direction parallel to the rolling direction is not particularly limited, but for example, it may be 55.0% IACS or lower, or 50.0% IACS or lower.

[0035] Conductivity is measured using the four-terminal method in accordance with JIS H0505 (1975). A double bridge is used for measurement, and resistance can be measured based on the average cross-sectional area method. Conductivity can be measured at room temperature (25°C) in the direction parallel to the rolling direction. The gauge length (distance between electrical resistance measurements) can be 50 mm.

[0036] (Elongation at Break) The elongation at break of copper alloys is measured in a direction parallel to the rolling direction using a tensile testing machine in accordance with JIS Z2241:2011. Specifically, test specimens are prepared using the same method as for tensile strength as described above. The test is also performed under the same conditions as for tensile strength as described above. The elongation at break is calculated using the following formula. The definitions of final gauge length and original gauge length are the same as in JIS Z2241:2011. Elongation at break (%) = (Final gauge length - Original gauge length) ÷ Original gauge length

[0037] (Shape) Copper alloys can be in the form of strips or plates, and this also includes sheets. Copper alloys include copper alloy strips and copper alloy plates. When copper alloy plates are thin (for example, less than 0.10 mm), they are sometimes called copper alloy foils.

[0038] The thickness of the copper alloy may be, for example, 0.03 mm to 1.20 mm, 0.03 mm to 0.60 mm, or 0.08 mm to 0.30 mm.

[0039] The thickness of the copper alloy is measured using a micrometer in accordance with JIS B7502. A Mitutoyo BMS-25MX or equivalent micrometer is used.

[0040] (Manufacturing Method) The above-mentioned method for manufacturing copper alloys may include, for example, melting and casting, hot rolling, heat treatment, intermediate cold rolling, solution treatment, aging treatment, and final cold rolling in this order.

[0041] In melting and casting, the raw materials are melted to cast a copper alloy ingot containing 1.5% to 4.6% by mass of Ni, 0.10% to 0.80% by mass of Co, 0.10% to 1.3% by mass of Si, and 0.010% to 0.10% by mass of Cr, with the remainder being Cu and unavoidable impurities. Next, the ingot is subjected to arbitrary homogenization annealing, then processed into a plate shape by hot rolling, and further cold rolling is performed as needed to achieve a predetermined thickness.

[0042] After that, in order to control the volume fraction of the Cube orientation of the finally manufactured copper alloy as described above, it is important to perform a solution treatment immediately after high-degree cold rolling (intermediate cold rolling). One of the recrystallized textures of copper and copper alloys is the Cube orientation {001}<100>. By heating sufficiently during the solution treatment to promote recrystallization and subsequent grain growth, the Cube orientation can be developed, and the volume fraction of the Cube orientation of the finally manufactured copper alloy can be increased. Specifically, the value of X represented by the following formula (1) for the semi-finished product obtained after the solution treatment (typically the strip material after the solution treatment during manufacturing) is adjusted to a predetermined value. Also, in order to increase the volume fraction of the Cube orientation, it is important to perform high-degree cold rolling and then perform a solution treatment immediately after introducing strain to promote recrystallization and subsequent grain growth. If necessary, heat treatment and cold rolling may be repeated before the solution treatment.

[0043] Specifically, the above X is a value represented by formula (1): X = (TS) × (EC) 2 Here, TS in formula (1) means the tensile strength (unit: MPa) of the semi-finished product obtained by the solution treatment, and EC means the conductivity (unit: %IACS) of the semi-finished product. The tensile strength and conductivity of the semi-finished product can be measured according to the methods described above.

[0044] It was found that there is a certain correlation between X of the semi-finished product and the volume fraction of the Cube orientation of the finally manufactured copper alloy, as exemplified in FIG. 1. Based on this finding, it is preferable to set the conditions of the solution treatment so that the value of X in formula (1) is 87661 or less. Thereby, it becomes easier to control the volume fraction of the Cube orientation of the copper alloy to 30.0% or more. The value of X is preferably 50000 or more and 85000 or less. If the value of X is too small, over-solution may occur, and the tensile strength of the copper alloy may decrease.

[0045] When performing heat treatment before cold rolling, the heat treatment conditions can be 400°C to 800°C for 1 second to 25 hours. The degree of cold rolling (intermediate cold rolling) before solution treatment can be 60% to 99%. Each condition can be appropriately set so that X becomes a predetermined value. Note that the degree of work (%) is expressed as work (%) = [(TB - TA) / TB] × 100, where TB is the thickness of the workpiece before rolling and TA is the thickness of the workpiece after rolling.

[0046] The temperature of the solution treatment is, for example, 800°C to 1,ooo°C, and may be 850°C to 975°C. The time of the solution treatment is, for example, 1 second to 60 seconds, and may be 5 seconds to 30 seconds. By making the heating temperature of the solution treatment relatively high, the value of X in formula (1) tends to become small. This is considered to be due to the increase in the amount of impurity elements dissolved in the matrix phase and the decrease in conductivity when the heating temperature of the solution treatment is high.

[0047] The temperature of the aging treatment is, for example, 375°C to 625°C, and may be 400°C to 550°C. The time of the solution treatment is, for example, 1 hour to 50 hours, and may be 1.5 hours to 25 hours. By performing the aging treatment at an appropriate temperature and time, Ni-Co-Si-based compounds are sufficiently precipitated, and coarsening and re-solution of the precipitates are suppressed, so that the strength and conductivity can be greatly improved. The aging treatment is preferably performed in an inert atmosphere such as Ar, N2, H2, etc. to suppress the generation of an unintentional oxide film.

[0048] In the final cold rolling, rolling is performed in one or more passes The final cold rolling may be performed in a plurality of passes. The total degree of work in the final cold rolling is preferably 40% or more. Thereby, processing strain is applied to the material and the strength is increased. On the other hand, in order to suppress the decrease in conductivity due to the processing strain of severe working, the total degree of work may be 90% or less. After the final cold rolling, strain relief annealing may be performed, for example, in the atmosphere or in an inert atmosphere such as nitrogen or argon gas. The conditions for strain relief annealing are, for example, 300°C to 550°C for 5 seconds to 900 seconds.

[0049] Furthermore, in the manufacturing method described above, after each rolling and heat treatment including solution treatment and aging treatment, pickling, polishing, degreasing, surface grinding, and trimming may be performed as needed. In addition, other rolling and heat treatments may be performed at appropriate times in addition to the rolling and heat treatments described above.

[0050] The embodiments described above include the copper alloys described in (1) to (8) below and the electronic components described in (9) below. (1) A copper alloy containing 1.5% by mass or more and 4.6% by mass or less of Ni, 0.10% by mass or more and 0.80% by mass or less of Co, 0.10% by mass or more and 1.3% by mass or less of Si, and 0.010% by mass or more and 0.10% by mass or less of Cr, with the remainder being Cu and unavoidable impurities, and having a volume fraction of 30.0% or more in the Cube orientation. (2) The copper alloy according to (1), further containing a total of 0.010% by mass or more and 5.0% by mass or less of one or more elements selected from the group consisting of Mg, Fe, P, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo, and Mn. (3) The copper alloy according to (1) or (2), wherein the volume fraction in the Cube orientation is 70.0% or less. (4) The copper alloy according to any of (1) to (3), wherein the volume fraction in the Cube orientation is 35.0% or more and 50.0% or less. (5) The copper alloy according to any of (1) to (4), wherein the volume fraction in the Cube orientation is 40.0% or more and 45.0% or less. (6) The copper alloy according to any of (1) to (5), wherein the tensile strength in the direction parallel to the rolling direction is 850 MPa or more. (7) The copper alloy according to any of (1) to (6), wherein the electrical conductivity in the direction parallel to the rolling direction is 35.0% IACS or more. (8) The copper alloy according to any of (1) to (7), wherein the total mass ratio of Ni and Co to Si is 3.4 or more and 5.4 or less. (9) An electronic component containing a copper alloy as described in any of (1) to (8).

[0051] The following describes the results of fabricating the aforementioned copper alloy and confirming its effects. However, this description is for illustrative purposes only and is not intended to limit the present invention to this.

[0052] Using electrolytic copper as the raw material, an ingot with the composition shown in Table 1 was cast by melting it in an atmospheric melting furnace. After homogenization annealing of this ingot at 980°C for 25 minutes, it was hot-rolled to a plate thickness of 10 mm and then surface-machined. Subsequently, after the heat treatment and intermediate cold rolling described above, solution treatment, aging treatment, final cold rolling, and stress-relieving annealing were sequentially performed under the conditions shown in Table 1. The main conditions for intermediate cold rolling, solution treatment, aging treatment, final cold rolling, and stress-relieving annealing are shown in Table 1. This yielded copper alloy plates (plate-shaped copper alloys) for the examples and comparative examples. As described above, the tensile strength (MPa) and electrical conductivity (%IACS) of the semi-finished products after solution treatment but before aging treatment were measured, and the value of X was calculated using the above formula (1).

[0053] For each copper alloy sheet manufactured in Examples 1-5 and Comparative Examples 1-3, the tensile strength in the direction parallel to the rolling direction, electrical conductivity, and volume fraction in the cube orientation were measured according to the method described above. The results are shown in Table 1. In addition, for each copper alloy sheet, the 0.2% yield strength and elongation at break in the direction parallel to the rolling direction were also measured according to the method described above. The results are also shown in Table 1.

[0054] The bendability of each copper alloy sheet in Examples 1-5 and Comparative Examples 1-3 was evaluated by measuring the MBR / t in accordance with JIS H3130:2012. Specifically, each copper alloy sheet was cut into 10 mm x 25 mm specimens with the shorter side parallel to the rolling direction. For each specimen, a W-bending test was performed at a bending angle of 90°, with the bending axis parallel to the rolling direction (RD direction) of the copper alloy sheet. The cross-section of the specimen was observed with an optical microscope, and the safe bending radius (MBR / t) was defined as the bending radius (mm) at which no cracks occurred divided by the thickness (mm) of the specimen. A smaller MBR / t value indicates better bendability (bendability).

[0055]

[0056] The copper alloy sheets of Examples 1 to 5 had a lower MBR / t than the copper alloy sheets of Comparative Examples 1 to 3. Therefore, it can be said that the copper alloy sheets of Examples 1 to 5 have better bendability than the copper alloy sheets of Comparative Examples 1 to 3. In addition, the copper alloy sheets of Examples 1 to 5 had a large tensile strength of 973 MPa or more.

[0057] (Potential Contribution to SDGs) According to the embodiment described above, it is possible to provide a copper alloy with improved bendability, which may contribute to the high functionality and improved reliability of electronic devices. High functionality and improved reliability of electronic devices are required for the realization of an AI / IoT society. For this reason, this embodiment may contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

Claims

1. A copper alloy containing 1.5% by mass or more and 4.6% by mass or less of Ni, 0.10% by mass or more and 0.80% by mass or less of Co, 0.10% by mass or more and 1.3% by mass or less of Si, and 0.010% by mass or more and 0.10% by mass or less of Cr, with the remainder being Cu and unavoidable impurities, and having a volume fraction of 30.0% or more in the Cube orientation.

2. The copper alloy according to claim 1, further containing a total of 0.010% by mass or more and 5.0% by mass or less of one or more elements selected from the group consisting of Mg, Fe, P, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo, and Mn.

3. The copper alloy according to claim 1, wherein the volume fraction in the cube orientation is 70.0% or less.

4. The copper alloy according to claim 3, wherein the volume fraction in the cube orientation is 35.0% or more and 50.0% or less.

5. The copper alloy according to claim 4, wherein the volume fraction in the cube orientation is 40.0% or more and 45.0% or less.

6. The copper alloy according to claim 1, wherein the tensile strength in a direction parallel to the rolling direction is 850 MPa or more.

7. The copper alloy according to claim 1, wherein the electrical conductivity in a direction parallel to the rolling direction is 35.0% IACS or higher.

8. The copper alloy according to claim 1, wherein the total mass ratio of Ni and Co to Si is 3.4 or more and 5.4 or less.

9. An electronic component comprising the copper alloy described in any one of claims 1 to 8.

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