JP6830135B2 - Cu-Ni-Co-Si alloy for electronic components - Google Patents

Description

The present invention relates to Cu-Ni-Co-Si alloys for electronic components suitable for electronic components, particularly connectors, battery terminals, jacks, relays, switches, lead frames and the like.

Conventionally, as materials for electrical and electronic devices, copper-based materials such as phosphor bronze, tan copper, and brass, which are excellent in electrical conductivity and thermal conductivity, are widely used in addition to iron-based materials. In recent years, there has been an increasing demand for miniaturization, weight reduction, high functionality, and high-density mounting of electrical and electronic equipment, and various characteristics are required for copper-based materials applied to these.

With the miniaturization of parts, the thickness of materials is becoming thinner, and improvement of material strength is required. In applications such as relays, the demand for fatigue characteristics is increasing, and it is necessary to improve the strength. Further, with the miniaturization of parts, the conditions for bending are becoming stricter, and it is required to have high strength and excellent bending workability.

In Patent Document 1, in particular, it has a very high strength of 0.2% proof stress of 980 MPa or more or 1000 MPa or more, and has a conductivity of 30% IACS or more, more preferably 34% or more, and has stress relaxation resistance and stress relaxation characteristics. A Cu-Ni-Co-Si-based copper alloy plate material having good press workability has been proposed. According to Patent Document 1, this copper alloy plate material is used for heat treatment 1, hot rolling, cold rolling, solidification heat treatment for heating and holding slabs at a high temperature, and for promoting precipitation of Co—Si compounds during aging. It is manufactured through heat treatment 2 that imparts a heat history including pretreatment heat treatment, and aging treatment that is performed in a low temperature range.

Japanese Unexamined Patent Publication No. 2014-156623 Japanese Unexamined Patent Publication No. 2011-231393 JP-A-2009-007666

By the way, according to Patent Document 1, it is described that in a Cu—Ni—Co—Si alloy, precipitates of two kinds of compounds, a Ni—Si compound and a Co—Si compound, are formed depending on the aging temperature. It is presumed that different compositions have different effects of precipitates on dislocations. That is, it is considered that the amount of dislocations introduced differs depending on the composition of the precipitate. Due to the non-uniform dislocation, stress during bending is concentrated, and bending workability may be impaired.

Therefore, for example, in Patent Document 2, by increasing the proportion of crystal grains having a {100} orientation (Cube orientation) with less anisotropy, the bending workability can be improved and at the same time the anisotropy of the bending workability can be improved. It is stated that it can be significantly improved. Specifically, a melting / casting step of melting and casting a copper alloy raw material, a hot rolling step performed after this melting / casting step, and a hot rolling step after this hot rolling step. A first cold rolling step in which cold rolling is performed at a rolling ratio of 70% or more, an intermediate annealing step in which heat treatment is performed at a heating temperature of 500 to 650 ° C. after the first cold rolling step, and an intermediate annealing step. A second cold rolling step in which cold rolling is performed later at a rolling ratio of 70% or more, a solution treatment step in which a solution treatment is performed after the second cold rolling step, and 400 after this solution treatment step. It is realized by a method including an aging treatment step in which aging treatment is performed at ~ 500 ° C.

Further, for example, in Patent Document 3, the diffraction intensity from the {111} plane on the plate surface is I {111}, the diffraction intensity from the {200} plane is I {200}, and the diffraction intensity from the {220} plane is I {. 220}, the diffraction intensity from the {311} plane is I {311}, and the ratio of the diffraction intensity from the {200} plane to these diffraction strengths is R {200} = I {200} / (I {111}). In the case of + I {200} + I {220} + I {311}), a technique for improving bending workability by setting R {200} to a certain level or more is described, and specifically, the final diffraction heat treatment. This is achieved by introducing intermediate annealing to the extent that the processed structure does not completely recrystallize, and in addition, intermediate rolling.

In the future, the Corson copper alloy will be required to have high strength and high conductivity as well as bendability, and it is generally difficult to achieve both strength and bendability, so there is room for improvement from the viewpoint of improving reliability. There is.

As a result of diligent research by the present inventor, in the Cu—Ni—Co—Si alloy, if the variation in the crystal grain size can be suppressed, the dislocations become uniform and the stress during bending is dispersed. From the viewpoint that improvement in bending workability is expected, the optimum solution treatment conditions have been found, and the present invention has been completed.

That is, the present invention
(1) It contains 3.0 to 4.5% by mass of Ni and 0.1 to 1.0% by mass of Co, and the concentration (mass%) ratio (Ni / Co) of Ni to Co is 3.5. Adjusted to ~ 30, and contains Si so that the mass ratio of (Ni + Co) / Si is 3 to 5, and the balance consists of Cu and unavoidable impurities, and electrons are used in the cross section parallel to the rolling direction. A Cu-Ni-Co-Si alloy for electronic parts in which the variation coefficient of the crystal grain size is 30% or less when the orientation difference of 5 ° or more is regarded as the grain boundary by performing backward scattering diffraction measurement.
(2) Further described in (1), further containing at least one selected from the group of Fe, Mg, Sn, Zn, B, P, Cr, Zr, Ti, Al and Mn in a total of up to 2.5% by mass. alloy.
(3) The alloy according to (1) or (2), wherein the average number of second-phase particles having a particle size of 5 to 30 nm is 0.5 × 10 ⁹ particles / mm ² or more.
(4) The alloy according to any one of (1) to (3), wherein the 0.2% proof stress in the direction parallel to the rolling direction is 900 MPa or more and the conductivity is 30% IACS or more.
(5) The average roughness Ra of the surface of the bent portion when the W bending test is performed in Badway (the bending axis is in the same direction as the rolling direction) with the bending radius (R) / plate thickness (t) = 1.0 is 1.0 μm or less. The alloy according to any one of (1) to (4).
(6) An electronic component provided with the alloy according to any one of (1) to (5).

According to the present invention, in addition to high strength and high conductivity, a Cu-Ni-Co-Si alloy for electronic parts, which is generally difficult to achieve both strength and has improved reliability, is provided to the Corson copper alloy. Provided.

Hereinafter, an embodiment of the Cu—Ni—Co—Si alloy for electronic components according to the present invention will be described. In the present invention,% means mass% unless otherwise specified.

(1) Composition of base material First, the alloy composition will be described. The copper alloy of the present invention is a Cu—Ni—Co—Si alloy. In this specification, a copper alloy obtained by adding other alloying elements such as Fe, Mg, Sn, Zn, B, P, Cr, Zr, Ti, Al and Mn to the basic components of Cu—Ni—Co—Si. Is also collectively referred to as a Cu-Ni-Co-Si alloy.

Ni has the effect of forming a Ni—Co—Si-based precipitate together with Co and Si described later to improve the strength and conductivity of the copper alloy plate material. If the Ni content is too small, it is difficult to fully exert this effect. Therefore, the Ni content is preferably 3.0% by mass or more, more preferably 3.2% by mass or more, and even more preferably 3.4% by mass or more. On the other hand, if the Ni content is too large, the strength improving effect is saturated and the conductivity is lowered. In addition, coarse precipitates are likely to be formed, which causes cracks during bending. Therefore, the Ni content is preferably 4.5% by mass or less, and more preferably 4.1% by mass or less.

Co has the effect of forming Ni—Co—Si-based precipitates together with Ni and Si to improve the strength and conductivity of the copper alloy plate material. If the Co content is too small, it is difficult to fully exert this effect. Therefore, the Co content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more. On the other hand, since the melting point of Co is higher than that of Ni, if the Co content is too large, complete solid solution is difficult, and the unsolid solution portion does not contribute to the strength. Therefore, the Co content is preferably 1.0% by mass or less, and more preferably 0.8% by mass or less.

Further, from the viewpoint of suppressing variation in crystal grain size, it is preferable to adjust the Ni / Co concentration (mass%) ratio to be 3.5 to 30, preferably 5 to 15.

Si, together with Ni and Co, produces Ni—Co—Si-based precipitates. However, not all of Ni, Co and Si in the alloy become precipitates by the aging treatment, and they exist in a solid solution state in the Cu matrix to some extent. Ni, Co, and Si in the solid solution state slightly improve the strength of the copper alloy plate material, but the effect is smaller than that in the precipitated state, and it becomes a factor of lowering the conductivity. Therefore, it is generally preferable that the Si content be as close as possible to the composition ratio of the precipitate (Ni + Co) ₂ Si. That is, it is common to adjust the (Ni + Co) / Si mass ratio to 3 to 5 centered on about 4.2, and Si is added so that the (Ni + Co) / Si mass ratio is in this range. ..

Fe, Mg, Sn, Zn, B, P, Cr, Zr, Ti, Al, Mn and the like may be added to the copper alloy plate material of the present invention, if necessary. For example, Sn and Mg have the effect of improving stress relaxation resistance, Zn has the effect of improving the solderability and castability of copper alloy plates, and Fe, Cr, Mn, Ti, Zr, Al and the like have the effect of improving strength. It has the effect of improving. In addition, P has a deoxidizing effect, B has an effect of refining the cast structure, and has an effect of improving hot workability. However, if the amount of these additive elements is too large, the manufacturability is greatly impaired. Therefore, a total of 0 to 2.5% by mass can be contained. Further, considering the balance between strength, conductivity and bendability, it is preferable to contain one or more of the above elements in a total amount of 0.2 to 1.0% by mass. For each added element, considering the balance of stress relaxation resistance, strength, solderability, castability, hot workability, etc., Zn is 0.1 mass in the range not exceeding the total amount. % Or more and 2.0% by mass or less can be contained, Sn and Cr can be contained in an amount of 0.1% by mass or more and 1.0% by mass or less, and Fe, Mg and Mn can be contained in an amount of 0.1% by mass or more and 0% by mass. It can contain 5% by mass or less, and B, P, Zr, Ti and Al can be contained in an amount of 0.01% by mass or more and 0.3% by mass or less.

(2) Crystal grain size The alloy of the present invention is characterized in that the relative variation in crystal grain size is small. This variation is evaluated using a coefficient of variation calculated from standard deviation / average particle size × 100 from the average crystal grain size and standard deviation measured by the following method, and this value is 30% or less, preferably 20%. It is as follows.
The particle size of the precipitate is measured by performing electron backscattering diffraction measurement in a cross section parallel to the rolling direction, and using an orientation difference of 5 ° or more as a crystal grain boundary.

(3) Strength and Conductivity The alloy of the present invention has high strength and high conductivity, and is suitable for electronic components, particularly connectors, battery terminals, jacks, relays, switches, lead frames and the like.
Here, the strength is measured by preparing a JIS 13B test piece using a press machine so that the tensile direction is parallel to the rolling direction, and performing a tensile test of this test piece in accordance with JIS-Z2241. Evaluate as 0.2% bearing capacity (YS) in the direction. From the viewpoint of the above-mentioned applications, the 0.2% proof stress is preferably 900 MPa or more, and particularly 950 MPa or more.
Further, the conductivity is evaluated as the conductivity (EC:% IACS) measured by the 4-terminal method in accordance with JIS H 0505. From the viewpoint of the above-mentioned applications, the conductivity is preferably 30% IACS or more, and particularly 35% IACS or more.

(4) Bendability Surface Roughness In the present invention, the bendability is evaluated as the average roughness Ra of the surface of the bent portion when the W bending test is performed.
That is, the smaller the average roughness Ra of the surface of the bent portion when the W bending test is performed in Badway (the bending axis is in the same direction as the rolling direction) with the bending radius (R) / plate thickness (t) = 1.0, the more the bending process is performed. The stress at the time is dispersed, and it is expected that the bending workability will be improved. From this viewpoint, the average roughness Ra of the surface of the bent portion is preferably 1.0 μm or less.
(5) Number Concentration of Precipitates In the present invention, improvement of strength, conductivity and bendability is an object of the present invention by controlling the precipitates. Therefore, it is preferable to evaluate the number of precipitates. That is, the number density of precipitates having a particle size counts the number of second phase particles of 5 to 30 nm, divided by the observation area, and calculates the number density (× 10 ⁹ pieces / mm ^2), similarly 20 A visual field (1 μm × 1 μm for each visual field) is calculated and evaluated as an average value thereof.
Specifically, after exposing the cross section by cutting the cross section parallel to the rolling direction with a focused ion beam (FIB), a scanning transmission electron microscope (JEOL Ltd. model: JEM-2100F) is used. Determine the number concentration of precipitates to be measured. From the viewpoint of ensuring sufficient strength (0.2% proof stress), the number concentration of the precipitates is preferably 0.5 × 10 ⁹ pieces / mm ² or more, and more preferably 1.5 × 10 ⁹ pieces / mm ^2. It is preferably mm ² or more.
Here, the second phase particles are crystallization generated in the solidification process of melt casting, precipitates generated in the subsequent cooling process, precipitates generated in the cooling process after hot rolling, and cooling process after solution treatment. It refers to the precipitates that are formed and the precipitates that are formed during the aging treatment process, and usually has a Co-Si-based or Ni-Si-based composition, but in the case of the present invention, it has a Ni-Co-Si-based composition. Is typical. The size of the second phase particles is defined as the diameter of the maximum circle that can be surrounded by the precipitate when the cross section parallel to the rolling direction is observed by electron microscopy.

(6) Applications The Cu-Ni-Co-Si alloy according to the present invention can be processed into various copper products such as plates, strips, pipes, rods and wires. The copper alloy of the present invention is suitable as a material for electronic components such as connectors, battery terminals, jacks, relays, switches, and lead frames, although it is not limited.

(7) Manufacturing Method The Cu-Ni-Co-Si alloy for electronic parts according to the embodiment of the present invention is melt-casted ingot (step 1) -homogeneous annealing, hot rolling, quenching (step 2) -cold rolling. , Dissolved treatment (step 3) -manufactured through aging treatment (step 4).

<Ingot manufacturing>
Using an atmospheric melting furnace, raw materials such as electrolytic copper, Ni, Co, and Si are melted to obtain a molten metal having a desired composition. Then, this molten metal is cast into an ingot. Additive elements other than Ni, Co, and Si are one or more from the group consisting of Fe, Mg, Sn, Zn, B, P, Cr, Zr, Ti, Al, and Mn, totaling 0 to 2.5 mass. % Is added so as to contain.

<Homogeneous annealing and hot rolling>
Since the solidification segregation and crystallization generated during the production of ingots are coarse, it is desirable to dissolve them in the matrix as much as possible by homogenization annealing to make them as small as possible and eliminate them as much as possible. This is because these have an adverse effect on bending workability and are effective in preventing bending cracks by being dissolved in the matrix phase.
Specifically, after the ingot manufacturing process, hot rolling is carried out after heating to 900 to 1050 ° C. and homogenizing annealing for 3 to 24 hours. The path from the original thickness to the total reduction rate of 90% is preferably 700 ° C. or higher. Then, it is rapidly cooled to room temperature by water cooling.

<Cold rolling and solution treatment>
Then, cold rolling is performed under the conditions of a degree of processing (rolling ratio) of 50% or more, preferably 70% or more, and then solution treatment is performed. Specifically, it is heated to 900 to 1050 ° C. for 30 seconds to 10 minutes. The purpose of the solution treatment is to dissolve additive elements such as Ni, Co, and Si as a solid solution. Therefore, it is important to control the heating rate and the cooling rate in addition to the heating temperature and the heating time. At the time of temperature rise before the solution treatment, the temperature rise rate of 600 to 700 ° C., which affects the precipitation of the second phase particles containing Co, is controlled to 50 ° C./sec or more. On the other hand, the cooling rate in the same temperature range after the solution treatment is also controlled to 50 ° C./sec or more. It is preferable that the temperature rising rate and the cooling rate be as high as possible in other temperature regions as well. Further, by adjusting the tension applied to the material at this time to 1 MPa or more and 10 MPa or less, it becomes possible to more conveniently control the precipitation of the second phase particles, and electron rear scattering diffraction measurement in a cross section parallel to the rolling direction. The fluctuation coefficient of the crystal grain size when the orientation difference of 5 ° or more is regarded as the crystal grain boundary can be set to 30% or less, and the number concentration of precipitates having a particle size of 5 to 30 nm can be sufficiently secured. , Makes it possible to impart sufficient strength.

As described above, by increasing the temperature rise and cooling rate at 600 to 700 ° C. during the solution treatment, the precipitation of the Co—Si compound is suppressed, and as a result, the precipitate of the Ni—Co—Si compound is produced. It is thought that it was. Further, the strength of the material during the solution treatment was increased by lowering the tension of the material from the conventional value of about 20 MPa. Although this mechanism is unknown, the strain introduced when cold rolling was performed in the previous process was uniformly released by controlling the temperature rise rate, and the strength was increased by the subsequent aging treatment. It is thought that it may be.

<Aging process>
Following the solution treatment, aging treatment is performed. It is preferable to heat at a material temperature of 400 to 550 ° C. for 5 to 25 hours, and more preferably to heat at a material temperature of 420 to 500 ° C. for 10 to 20 hours. The aging treatment is preferably carried out in an inert atmosphere such as Ar, N ₂ or H ₂ in order to suppress the formation of an oxide film.

<Final cold rolling>
Following the aging process, the final cold rolling is performed. The strength can be increased by the final cold working, but in order to obtain a good balance between high strength and bending workability as intended in the present invention, the reduction ratio is set to 15 to 45%, preferably 20 to 40. It is desirable to set it to%.

<Distortion annealing>
Following the final cold rolling, strain relief annealing is performed. It is preferable to heat at a material temperature of 350 to 650 ° C. for 1 to 600 seconds, a material temperature of 350 to 450 ° C. for 1500 to 3600 seconds, a material temperature of 450 to 550 ° C. for 500 to 1500 seconds, and a material temperature of 550 to 650 ° C. for 1 to 1 to 1. It is more preferable to heat for 500 seconds.

It should be understood that those skilled in the art can appropriately perform steps such as grinding, polishing, and shot blast pickling for removing the oxide scale on the surface between the above steps.

Examples of the present invention (invention examples) are shown below together with comparative examples, but these are provided for a better understanding of the present invention and its advantages, and are not intended to limit the invention. ..

A copper alloy containing each of the additive elements shown in Table 1 and having a balance of copper and impurities was melted at 1300 ° C. in a high-frequency melting furnace and cast into an ingot having a thickness of 30 mm. Next, the ingot was heated at 1000 ° C. for 3 hours, hot-rolled to a plate thickness of 10 mm, and cooled quickly after the hot rolling was completed. Next, the surface was surface-cut to a thickness of 9 mm to remove scale, and then cold-rolled to obtain a plate having a thickness of 0.120 to 0.175 mm. Next, the solution treatment was performed at 950 ° C. for 120 seconds. Table 1 shows the heating rate, cooling rate, and tension in the temperature range of 600 to 700 ° C. at this time. Then, aging treatment and cold rolling were added under the conditions shown in Table 1 to obtain a plate thickness of 0.1 mm. Finally, strain relief annealing was applied at a material temperature of 400 ° C. for 2000 seconds.

The following evaluation was performed on the prepared product sample. The evaluation results are shown in Table 2.
(1) 0.2% proof stress A JIS 13B test piece was prepared using a press machine so that the tensile direction was parallel to the rolling direction. A tensile test of this test piece was carried out according to JIS-Z2241 to measure 0.2% proof stress (YS) in the rolling parallel direction.

(2) Conductivity The conductivity (EC:% IACS) was measured by the 4-terminal method in accordance with JIS H 0505.

(3) Surface roughness of bent portion A W bending test was carried out in accordance with JIS-H3130 (2012) at Badway (the bending axis is in the same direction as the rolling direction) and r / t = 1.0 (t = 0.1 mm). The outer peripheral surface of the bent portion of this test piece was observed. As an observation method, the outer peripheral surface of the bent portion was photographed using a lasertec confocal microscope HD100, and the average roughness Ra (based on JIS-B0601: 2013) was measured and compared using the attached software. When the sample surface before bending was observed using a confocal microscope, no unevenness could be confirmed, and the average roughness Ra was 0.2 μm or less.
The case where the surface average roughness Ra after bending was 1.0 μm or less was evaluated as ◯, and the case where Ra exceeded 1.0 μm was evaluated as x.

(4) Number concentration of precipitates having a particle size of 5 to 30 nm After exposing the cross section by cutting the cross section parallel to the rolling direction with a focused ion beam (FIB), a scanning transmission electron microscope (JEOL Ltd.) , Model: JEM-2100F) was used to measure the number concentration of precipitates.
Specifically, the acceleration voltage is 200 kV, the observation magnification is 1 million times, the number of second phase particles having a particle size of 5 to 30 nm is counted, divided by the observation area, and the number concentration (× 10 ⁹ particles / mm ² ). Was calculated. Similarly, measurements were performed on 20 fields of view, and the average value was taken as the number concentration.

(5) Fluctuation coefficient of crystal grain size After exposing the cross section of the obtained copper alloy material by cutting a cross section parallel to the rolling direction with a focused ion beam (FIB), EBSD (Electron Backscatter Diffraction:): Electron backscatter diffraction) measurement was performed.
・ Observation field of view: 200 μm × 200 μm
・ Step interval: 0.5 μm
For the measurement of the crystal grain size, crystal grain analysis was performed using OIM Analysis (Ver. 5.3) attached to EBSD. The azimuth difference of 5 ° or more was regarded as a grain boundary, the average particle size and the standard deviation were calculated, and the coefficient of variation (standard deviation / average particle size × 100) was obtained.

In Invention Examples 1 to 24, the coefficient of variation of the crystal particle size is 30% or less, the relative variation in the particle size of the precipitate is small, the 0.2% proof stress is 900 MPa or more, and the conductivity is high. It was 30% IACS or more, and the surface roughness of the bent portion was 1.0 μm or less, which was good. It can be said that these copper alloy materials have an excellent balance of high strength, high conductivity, and high bending workability.

Comparative Examples 1 to 18 are specific examples in which it is considered that the precipitation of the second phase particles could not be sufficiently controlled.
Comparative Example 1 is a specific example in which the temperature rising rate during the solution treatment is smaller than 50 ° C./s, and Comparative Example 2 is a specific example in which the cooling rate during the solution treatment is lower than 50 ° C./s. Comparative Examples 3 and 4 are a specific example in which the tension applied to the alloy material during the solution treatment is too small (Comparative Example 3) and a specific example in which the tension is too large (Comparative Example 4). It was found that in all of Comparative Examples 1 to 4, the coefficient of variation of the crystal grain size was too large, and it was difficult to exhibit sufficient bending workability, and in particular, Comparative Examples 3 and 4 had even lower strength.

Comparative Examples 5 and 6 are specific examples in which the heating conditions in the aging treatment after the solution treatment deviate from 400 to 550 ° C. As a result, it is not possible to secure a sufficient amount in the number concentration of precipitates having a particle size of 5 to 30 nm, which is considered to contribute to the strength, it is difficult to exert sufficient strength, and it is sufficient if the aging treatment temperature is too low. It turned out that it is also difficult to exert conductivity.

Comparative Example 7 is a specific example in which the Ni content in the components of the copper alloy is less than 3.0% by mass. It was found that when the Ni content is small, it is difficult to exert sufficient strength.
Comparative Example 8 is a specific example in which the Ni content in the components of the copper alloy exceeds 4.5% by mass. If the Ni content is large, cracks occur during hot rolling, and a product cannot be obtained.

Comparative Example 9 is a specific example in which Co is not contained in the copper alloy, and Comparative Example 10 is a specific example in which the Co content in the components of the copper alloy exceeds 1.0% by mass. It was found that it is difficult to exhibit sufficient bending workability unless the Co content is within an appropriate range.

Comparative Examples 11 and 12 are a specific example in which the (Ni + Co) / Si mass ratio in the copper alloy is too large (Comparative Example 11) and a specific example in which the mass ratio is too small (Comparative Example 12). If the (Ni + Co) / Si mass ratio is not in an appropriate range, the number concentration of precipitates having a particle size of 5 to 30 nm is not sufficient, resulting in inferiority in terms of both strength and conductivity.

Comparative Examples 13 and 14 are a specific example in which the Ni / Co concentration ratio before precipitation of the second phase particles in the copper alloy is too small (Comparative Example 13) and a specific example in which the Ni / Co concentration ratio is too large (Comparative Example 14). It was found that in all of Comparative Examples 13 and 14, the coefficient of variation of the crystal grain size was too large, and it was difficult to exhibit sufficient bending workability.

Comparative Example 15 is a specific example in which the total amount of the third additive element other than Ni, Co, and Si exceeds 2.5. If the amount of the third additive element is too large, the coefficient of variation of the crystal grain size becomes too large, resulting in inferior bending workability and conductivity.

Comparative Examples 16 to 18 are specific examples in which the tension applied to the alloy material during the solution treatment is large.
Comparative Example 18 is a specific example representing the aspect of Patent Document 3. It was found that the coefficient of variation of the crystal particle size was 30% or more, the number concentration of precipitates having a particle size of 5 to 30 nm was small, and it was difficult to exert sufficient strength.
Comparative Example 17 is a specific example representative of the aspect of Patent Document 2 in which the cooling rate during the solution treatment is further reduced to less than 50 ° C./s under the conditions of Comparative Example 18. It was found that the coefficient of variation of the crystal grain size was 30% or more, and it was difficult to exhibit sufficient bending workability.
Comparative Example 16 is a specific example representative of the aspect of Patent Document 1, in which the aging treatment after the solution treatment was further performed under the conditions of Comparative Example 17 under a temperature condition lower than a predetermined range. Even in this case, it was found that the coefficient of variation of the crystal grain size was 30% or more, and it was difficult to exhibit sufficient bending workability.

Claims (5)

3. 3. It contains 2 to 4.5% by mass of Ni and 0.1 to 1.0% by mass of Co, so that the concentration (mass%) ratio (Ni / Co) of Ni to Co is 3.5 to 30. , And Si is contained so that the mass ratio of (Ni + Co) / Si is 3 to 5, and the balance is composed of Cu and unavoidable impurities, and electron rear scattering diffraction measurement is performed in a cross section parallel to the rolling direction. go to state, and are variation coefficient of 30% or less of the grain diameter when the above misorientation 5 ° was regarded as crystal grain boundaries, the average particle size of the number of second-phase particles of 5~30nm is 0. 5 × 10 ⁹ pieces / mm ² or more der Ru electronic component Cu-Ni-Co-Si alloy. The alloy according to claim 1, further containing at least one selected from the group of Fe, Mg, Sn, Zn, B, P, Cr, Zr, Ti, Al and Mn in a total of up to 2.5% by mass. The alloy according to claim 1 or 2 , wherein the 0.2% proof stress in the direction parallel to the rolling direction is 900 MPa or more and the conductivity is 30% IACS or more. The average roughness Ra of the surface of the bent portion when the W bending test is performed in Badway (the bending axis is in the same direction as the rolling direction) with the bending radius (R) / plate thickness (t) = 1.0 is 1.0 μm or less. alloy according to any one of claims 1-3. Electronic component having an alloy according to any one of claims 1-4.