KR101297485B1 - Cu-ni-si-co-cr alloy for electronic material - Google Patents

Abstract

[Ni ＋ Co]/Si

5 이고, 재료 중에 분산되는 크기가 0.1 ㎛ 이상 5 ㎛ 이하인 Cr-Si 화합물에 대해, 그 분산 입자 중의 Si 에 대한 Cr 의 원자 농도비가 1 ∼ 5 로서, 그 분산 밀도가 1 × 10⁴ 개/㎟ 이상, 1 × 10⁶ 개/㎟ 이하인 전자 재료용 구리 합금.An object of the present invention is to provide a high strength and high conductivity Colson-based alloy by dramatically improving the characteristics, that is, exhibiting the effect of the addition of Cr better in the Cu-Ni-Co-Si-based alloy. Ni: 1.0-4.5 mass%, Si: 0.50-1.2 mass%, Co: 0.1-2.5 mass%, Cr: 0.0030-0.3 mass%, It is a copper alloy which consists of remainder Cu and an unavoidable impurity, Ni and The mass concentration ratio ([Ni + Co] / Si ratio) to Si of the total mass of Co is 4

[Ni + Co] / Si

5 and a Cr-Si compound having a size dispersed in the material of 0.1 µm or more and 5 µm or less, wherein the atomic concentration ratio of Cr to Si in the dispersed particles is 1 to 5, and the dispersion density thereof is 1 × 10 ⁴ pieces / mm 2. The copper alloy for electronic materials which is 1x10 <^6> piece / mm <2> or less as mentioned above.

Description

Cu-Ni-Si-Cor-Cr-based alloy for electronic materials {CU-NI-SI-CO-CR ALLOY FOR ELECTRONIC MATERIAL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to precipitation hardening copper alloys, and in particular to Cu-Ni-Si-Co-Cr based alloys suitable for use in various electronic device components.

Copper alloys for electronic materials used in various electronic device components such as lead frames, connectors, pins, terminals, relays, and switches are required to have both high strength and high conductivity (or thermal conductivity) as basic characteristics. In recent years, high integration, miniaturization, and thinning of electronic components have progressed rapidly, and correspondingly, the level of demand for copper alloys used in electronic component parts has been increasing.

In view of high strength and high electrical conductivity, the amount of precipitation hardening copper alloys has been increasing in recent years instead of solid solution reinforced copper alloys represented by conventional phosphor bronze, brass and the like as copper alloys for electronic materials. In the precipitation hardening-type copper alloy, by aging the solution-treated supersaturated solid solution, fine precipitates are uniformly dispersed, the strength of the alloy is increased, and the amount of the solid solution element in copper is reduced to improve electrical conductivity. For this reason, the material which is excellent in mechanical properties, such as strength and elasticity, and is excellent in electrical conductivity and thermal conductivity is obtained.

Among the precipitation hardening copper alloys, Cu-Ni-Si-based copper alloys commonly referred to as Colson-based alloys are representative copper alloys having relatively high conductivity, strength, stress relaxation characteristics, and bendability, which are currently being actively developed in the industry. Is one of the alloys. In this copper alloy, it is possible to improve the strength and the conductivity by depositing fine Ni-Si intermetallic compound particles in the copper matrix.

 It is known that Cu-Ni-Si-based copper alloys improve their properties by adding Co and Cr. Co and Cr form Si and a compound similarly to Ni, and can improve strength.

[Ni ＋ Co]/Si

5, 그 합금 조성 중의 Ni 와 Co 의 질량 농도비 (Ni/Co 비) 가 0.5

Ni/Co

2 이고, 재료 중에 분산되는 크기가 1 ㎛ 이상인 개재물의 개수 (P), 그 중, 함유 탄소 농도가 10 질량％ 이상인 개재물의 개수 (Pc) 에 대해, Pc 가 15 개/1000 ㎛² 이하 또한, 그 비 (Pc/P) 가 0.3 이하인 것을 특징으로 하는 전자 재료용 Cu-Ni-Si-Co-Cr 계 구리 합금이 기재되어 있다.Japanese Laid-Open Patent Publication No. 2006-283120 (Patent Document 1) describes the characteristics (particularly strength and conductivity) of Cu-Ni-Si-based alloys containing Co and Cr, including the size and composition of inclusions under certain compositional conditions and manufacturing conditions. In other words, it is said that it is greatly improved when the distribution is controlled. Specifically, Ni: 0.5-2.5 mass%, Co: 0.5-2.5 mass%, Si: 0.30-1.2 mass%, Cr: 0.09-0.5 mass%, and remain | survived copper comprised from Cu and an unavoidable impurity In the alloy, the mass concentration ratio ([Ni + Co] / Si ratio) to Si of the total amount of Ni and Co in the alloy composition is 4

[Ni + Co] / Si

5, the mass concentration ratio (Ni / Co ratio) of Ni and Co in the alloy composition is 0.5

Ni / Co

Pc is 15/1000 micrometer <^2> or less with respect to the number (P) of the interference | inclusion of 2 and the magnitude | size disperse | distributed in a material 1 micrometer or more, and the number (Pc) of the inclusions whose content carbon concentration is 10 mass% or more, The Cu-Ni-Si-Co-Cr system copper alloy for electronic materials is described whose ratio (Pc / P) is 0.3 or less.

Japanese Unexamined Patent Application Publication No. 2005-113180 (Patent Document 2) is not a Cu-Ni-Si-based copper alloy, but focuses on a compound of Cr and Si precipitated in a copper alloy. According to this, etching processability can be ensured while improving press punching workability by finely depositing the CrSi compound which has predetermined size and number density in a Cu matrix, and restricting the size of Cr compounds other than CrSi. And Cr: 0.1 to 0.25% by weight, Si: 0.005 to 0.1% by weight, Zn: 0.1 to 0.5% by weight, Sn: 0.05 to 0.5% by weight, the weight ratio of Cr to Si is 3 to 25, and the balance is Cu. And in the copper alloy composed of unavoidable impurities, a CrSi compound having a size of 0.05 µm to 10 µm is present in a number density of 1 × 10 ³ to 5 × 10 ⁵ / mm 2 in the copper matrix phase, and The copper alloy for electronic devices excellent in the etching workability and punching work property which make the size of Cr compound (other than CrSi compound) 10 micrometers or less is described. In manufacturing the said copper alloy, the heat processing temperature before hot processing shall be 850 degreeC-980 degreeC, and the process by the combination of cold processing and heat processing at the temperature of 400 degreeC-600 degreeC after hot processing once, or It is said that it is necessary to carry out plural times repeatedly.

Japanese Unexamined Patent Publication No. 2006-283120 Japanese Laid-Open Patent Publication 2005-113180

The recent demand for rapid improvement of the high integration of electronic components, miniaturization and thinning of the material properties is the same for the Cu-Ni-Si-Co-Cr alloy, which is the alloy system of the present invention.

However, Patent Literature 1 does not find a description of a Cr-Si compound.

Although Patent Document 2 describes that the etching workability and punching workability are improved by controlling the number density and size of the Cr-Si compound, the formation of Ni-Si compound or Co-Si compound is not considered in that Ni is not added. What is necessary is just to consider the conditions of Cr-Si compound formation only, and how to control Cr-Si compound in Cu-Ni-Si-Co-Cr type alloy was not examined.

Then, the subject of this invention is aiming at the improvement of a characteristic by controlling the precipitation state of a Cr-Si compound in Cu-Ni-Si-Co-Cr type alloy.

MEANS TO SOLVE THE PROBLEM This inventor discovered the following invention as a result of earnestly researching in order to solve the said subject. In the Cu-Ni-Si-Co-Cr alloy, the Si content is excessive with respect to Ni and Co, and the Ni silicide of Ni addition and the Co silicide of Co addition are reliably precipitated to increase the strength, while the excess is excessive. The produced Si is produced as a compound with Cr added thereto, and high conversion is achieved. An important point of the present invention is to control the growth of the Cr-Si compound so that the compound of Cr and Si grows excessively and there is no shortage of Si to be combined with Ni and Co. Specifically, the inventors have paid attention to the composition, size and number density of the Cr-Si compound, and found that the effect can be better obtained by controlling the temperature and cooling rate of the heat treatment step.

That is,

[Ni ＋ Co]/Si

5 이고, 잔부 Cu 및 불가피적 불순물로 구성되는 전자 재료용 구리 합금으로서, 재료 중에 분산되는 크기가 0.1 ㎛ ∼ 5 ㎛ 인 Cr-Si 화합물에 대해, 그 분산 입자 중의 Si 에 대한 Cr 의 원자 농도비가 1 ∼ 5 로서, 그 분산 밀도가 1 × 10⁴ 개/㎟ 를 초과하고, 1 × 10⁶ 개/㎟ 이하인 전자 재료용 구리 합금(1) Ni: 1.0-4.5 mass%, Si: 0.50-1.2 mass%, Co: 0.1-2.5 mass%, Cr: 0.003-0.3 mass%, The mass concentration ratio with respect to Si of the total mass of Ni and Co ([Ni + Co] / Si ratio) is 4

[Ni + Co] / Si

A copper alloy for electronic materials composed of residual Cu and unavoidable impurities, wherein the atomic concentration ratio of Cr to Si in the dispersed particles of the Cr-Si compound having a size dispersed in the material is 0.1 µm to 5 µm. Copper alloy for electronic materials whose dispersion density exceeds 1 * 10 <^4> / mm <2> and 1 * 10 <^6> / mm <2> or less as 1-5.

(2) The copper alloy for electronic material of (1), having a dispersion density of 50 particles / mm 2 or less, for the Cr-Si compound having a size dispersed in the material of more than 5 µm.

(3) Copper alloy for electronic materials as described in (1) or (2) which contains 0.05-2.0 mass% of 1 type, or 2 or more types further selected from Sn and Zn.

(4) (1) to (c) containing 0.001 to 2.0% by mass of one or two or more selected from Mg, Mn, Ag, P, As, Sb, Be, B, Ti, Zr, Al and Fe; Copper alloy for electronic materials in any one of 3)

(5) A flexible product using the copper alloy according to any one of the above (1) to (4)

(6) It is an electronic device component using the copper alloy in any one of said (1)-(4).

According to this invention, since the effect of the addition of Cr which is an alloying element is exhibited more favorable, the Cu-Ni-Si-Co-Cr type alloy for electronic materials which improved the strength and electrical conductivity is obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Addition amount of Ni, Co and Si

Ni, Co, and Si can form an intermetallic compound by performing appropriate heat processing, and can attain high strength, without degrading electrical conductivity. Hereinafter, the addition amount of each of Ni, Co, and Si is demonstrated.

About Ni and Co, it is necessary to set Ni: 1.0-4.5 mass% and Co: 0.1-2.5 mass% in order to satisfy moderate strength and electrical conductivity as a copper alloy for electronic materials, Preferably Ni: 1.0-2.0 mass% , Co: 1.0-2.0 mass%, More preferably, they are Ni: 1.2-1.8 mass%, Co: 1.2-1.8 mass%. However, when Ni: 1.0 mass% and Co: less than 0.1 mass%, respectively, desired intensity | strength cannot be obtained. On the contrary, when Ni exceeds 4.5 mass% and Co: 2.5 mass%, high strength can be achieved, but electrical conductivity will fall remarkably, Furthermore, since hot workability falls, it is not preferable.

About Si, it is necessary to set it as 0.30 to 1.2 mass% in order to satisfy target intensity and electrical conductivity, Preferably it is 0.5 to 0.8 mass%. However, if it is less than 0.3%, desired strength is not obtained, and if it exceeds 1.2 mass%, high strength can be attained, but since electrical conductivity will fall remarkably and also hot workability will fall, it is unpreferable.

In this invention, the weight concentration ratio ([Ni + Co] / Si) with respect to Si of the total amount of Ni and Co in an alloy composition was further prescribed | regulated.

Ni/Si

7 의 낮은 쪽으로 설정함으로써, 즉 Si 를 약간 많게 첨가함으로써, Ni, Co 를 남기지 않고 실리사이드화시켜, 석출에 기여하지 않는 과잉 Ni 및 Co 의 고용에 의한 도전율 저하를 경감시킬 수 있다. 그러나, 중량 농도비가 [Ni ＋ Co]/Si ＜ 4 인 경우에는, 이번에는 Si 의 비율이 지나치게 높기 때문에 고용 Si 에 의해 도전율이 저하될 뿐만 아니라, 소둔 공정에 있어서 재료 표층에 SiO₂ 의 산화 피막을 형성하기 때문에 납땜성이 열화된다. 또, 강화에 기여하지 않는 Ni-Co-Si 계 석출 입자가 조대화되기 쉬워져, 강도에 기여하지 않으며, 반대로 굽힘 가공시의 균열 발생 기점 (起點) 이나 도금 불량부가 되기 쉽다. 한편 Si 에 대한 Ni 및 Co 의 비율을 높여가, [Ni ＋ Co]/Si ＞ 5 가 되면 도전율이 현저하게 저하되어, 전자 재료용으로서 바람직하지 않다.In the present invention, the Ni / Si ratio is defined in the conventional range 3

Ni / Si

By setting it to the lower side of 7, ie, adding a little more Si, it can silicide without leaving Ni and Co, and can reduce the electrical conductivity fall by the solid solution of excess Ni and Co which do not contribute to precipitation. However, in the case where the weight concentration ratio is [Ni + Co] / Si <4, since the ratio of Si is too high at this time, not only the conductivity decreases due to solid solution Si, but also the oxide film of SiO ₂ on the material surface layer in the annealing process. Because of this, solderability deteriorates. Moreover, Ni-Co-Si type | system | group precipitated particle | grains which do not contribute to reinforcement tend to coarsen and do not contribute to strength, and conversely, it is easy to become the origin of a crack and the plating defect part at the time of bending work. On the other hand, when the ratio of Ni and Co with respect to Si increases and becomes [Ni + Co] / Si> 5, electrical conductivity will fall remarkably and it is unpreferable for the electronic material.

[Ni ＋ Co]/Si

5 의 범위로 제어한다.Therefore, in the present invention, the [Ni + Co] / Si ratio in the alloy composition is 4

[Ni + Co] / Si

Control in the range of 5.

[Ni ＋ Co]/Si

4.7 이다.[Ni + Co] / Si ratio is preferably 4.2

[Ni + Co] / Si

4.7.

Ni/Co

2 의 범위로 함으로써, 강도의 향상이 현저하게 확인된다. 보다 바람직하게는 0.8

Ni/Co

1.3 이다.Both Ni and Co not only contribute to the formation of a compound with Si, but are also considered to improve alloy properties in relation to each other, and may be further improved by controlling the weight concentration ratio (Ni / Co ratio) of Ni and Co in the alloy composition. have. Ni / Co ratio is preferably 0.5

Ni / Co

By setting it as 2 range, the improvement of strength is remarkably confirmed. More preferably 0.8

Ni / Co

1.3.

Amount of Cr added

In the Cu-Ni-Si-Co alloy, when the Ni, Si, and Co concentrations are increased, the total number of precipitated particles increases, so that the strength can be increased by precipitation strengthening. On the other hand, with the increase of the addition concentration, the high capacity which does not contribute to precipitation also increases, so that the conductivity decreases, and eventually the peak intensity of aging precipitation increases, but the conductivity that becomes the peak intensity decreases. However, if Cr is added to 0.003 to 0.3 mass%, preferably 0.01 to 0.1 mass% to the Cu-Ni-Si-based alloy, Cu-Ni-Si- having the same Ni, Si, and Co concentrations in final properties. Compared with Co-based alloys, the electrical conductivity can be increased without inhibiting the strength, and the hot workability is improved, and the yield is high.

The composition of the precipitated particles when Cr is added to the Cu—Ni—Si—Co alloy is easy to precipitate precipitated particles having a bcc structure mainly composed of Cr, but also easily precipitates a compound with Si. Since Cr can easily precipitate chromium silicide (Cr ₃ Si etc.) with a compound in Si in a copper base phase by performing appropriate heat processing, Cr is Ni in the process of making alloy characteristics combining a solution treatment, cold rolling, and an aging treatment. _A solid solution Si component which has not been precipitated as 2Si or CoSi ₂ can be precipitated as a Cr-Si compound. For this reason, the fall of the electrical conductivity by solid solution Si can be suppressed, and the electrical conductivity can be raised without impairing strength.

At this time, when the Si concentration in the Cr particles is low, the conductivity remains because Si remains in the mother phase. On the other hand, when the Si concentration in the Cr particles is high, the Si concentration for depositing Ni-Si particles or Co-Si particles decreases. The strength is lowered. In addition, when the Si concentration in Cr is high, coarse Cr-Si compounds increase, and bending, fatigue strength, and the like deteriorate. In addition, even if the cooling rate after the solution is slowly cooled or the aging heat treatment time is excessively extended, the concentration of Si, which coarsens the Cr-Si compound to form the Ni-Si compound, decreases, thereby contributing to the strengthening. Lack of this. This is because the diffusion rate of Si and Cr in Cu is faster than that of Ni or Co, so that the Cr-Si compound is easily coarsened, and the precipitation rate of the Cr-Si compound is faster than that of the Ni-Si compound and Co-Si particles. For losing.

Therefore, the composition, size and density of the Cr-Si compound can be controlled by controlling the cooling rate after the solution solution and avoiding the conditions that are higher than the aging condition which is the maximum strength for a long time. Therefore, Cr concentration was made into 0.003 mass% or more and 0.3 mass% or less, and the atomic concentration ratio of Cr with respect to Si in Cr-Si compound was 1-5.

In addition, since Cr is first precipitated at the grain boundaries during the cooling process during melt casting, the grain boundaries can be strengthened, so that cracks at the time of hot working are less likely to occur, and yield reduction can be suppressed. That is, Cr precipitated at the time of melt casting is re-used by solution treatment or the like, but silicide is generated during the aging precipitation. In the conventional Cu-Ni-Si-based alloys, Si, which did not contribute to aging precipitation, suppressed the increase in conductivity while being dissolved in the mother phase, by adding Cr, a silicide forming element, to further precipitate the silicide. Compared with the conventional Cu-Ni-Si-Co-based alloy, the amount of solid solution Si can be reduced, and the conductivity can be increased without inhibiting the strength.

Size, Dispersion Density of Cr-Si Compound

The size of the Cr-Si compound affects bending workability and fatigue strength, and the dispersion density of the Cr-Si compound exceeding 5 μm exceeds 50 pieces / mm 2, or the Cr—Si compound of 0.1 to 5 μm. When the dispersion density of is greater than 1 × 10 ⁶ particles / mm 2, bending workability and fatigue strength are remarkably deteriorated. In addition, since the number density affects the oversufficiency of the Si concentration in a mother phase, desired intensity | strength characteristic is not acquired in the state in which many large particle was disperse | distributed. Therefore, it is preferable that the dispersion density of the Cr-Si compound exceeding 5 micrometers shall be 50 pieces / mm <2> or less, Preferably it is 30 pieces / mm <2> or less, More preferably, it shall be 10 pieces / mm <2> or less. good. Dispersion density of 0.1-5 micrometers Cr-Si compound may be 1 * 10 <^6> pieces / mm <^2> or less, Preferably it is 5 * 10 <^5> pieces / mm <^2> or less, More preferably, it may be 1 * 10 <^5> pieces / mm <^2> or less. . Moreover, when it is 1 * 10 <^4> / mm <2> or less, since the improvement effect by Cr addition is small, it is preferable to exceed this, and in typical embodiment, it is 1 * 10 <^5> / mm <2> or more.

Sn and Zn

By adding 0.05 to 2.0 mass% of one or two or more selected from Sn and Zn in a total amount to the Cu-Ni-Si-based alloy according to the present invention, stress relaxation characteristics and the like can be improved without significantly inhibiting strength and conductivity. have. When the addition amount is less than 0.05 mass%, the effect is insufficient, and when it exceeds 2.0 mass%, it is preferable to add 0.05-2.0 mass%, since the manufacturing property, such as castability and hot workability, inhibits the electrical conductivity of a product.

Other additive elements

Mg, Mn, Ag, P, As, Sb, Be, B, Ti, Zr, Al, and Fe have various effects by adding a predetermined amount, which complements each other in addition to strength, conductivity, bending workability, plating property or ingot structure. Since there is also an effect of improving the manufacturability, such as improvement of hot workability by miniaturization, the total amount is 2.0 mass depending on the properties required for one or two or more of these to the Cu-Ni-Si-Co-Cr-based alloy according to the present invention It can be added suitably as% or less. If the total amount of these elements is less than 0.001% by mass, the desired effect is not obtained. If the total amount of these elements exceeds 2.0% by mass, the lowering of the conductivity and deterioration of manufacturability become remarkable, so the total amount is preferably 0.001 to 2.0% by mass. It is more preferable to set it as 0.01-1.0 mass%.

Moreover, the element not specifically described in this specification may be added in the range which does not adversely affect the characteristic of the Cu-Ni-Si-Co-Cr type alloy which concerns on this invention.

Next, the manufacturing method of this invention is demonstrated. The Cu-Ni-Si-Co-Cr based alloy according to the present invention is Cu-Ni-Si except for the solution treatment and the aging treatment to control the Ni-Si compound, Co-Si and Cr-Si compound. It can manufacture by the conventional manufacturing method of a system alloy.

First, raw materials, such as electric copper, Ni, Si, Co, and Cr, are melt | dissolved using an atmospheric melting furnace, and the molten metal of a desired composition is obtained. Then, the molten metal is cast into an ingot. Then, hot rolling is performed, cold rolling and heat processing are repeated, and it is completed by the roughness or foil which has desired thickness and characteristic. Heat treatment includes a solution treatment and an aging treatment. In the solution treatment, it heats at high temperature of 700-1000 degreeC, Ni-Si type compound, Ni-Si type compound, and Cr-Si type compound are made to solidify in Cu base material, and simultaneously recrystallize Cu base material. The solution treatment may also serve as hot rolling.

In this solution treatment, the cooling rate is also important along with the heating temperature. Conventionally, since the cooling rate after heating was not controlled, the water tank was installed in the exit side of a heating furnace, it was made into water-cooling, or air-cooling in air | atmosphere was employ | adopted. In this case, the cooling rate tends to fluctuate by setting the heating temperature, and the conventional cooling rate fluctuates within the range of 1 ° C / sec or less to 10 ° C / sec or more. Therefore, it was difficult to control the characteristics of the alloy system as in the present invention.

The cooling rate is preferably in the range of 1 ° C / sec to 10 ° C / sec. In the aging treatment, at least 1 h, typically 3 to 24 h, is heated at a temperature in the range of 350 to 550 ° C. to precipitate the compound of Ni and Si and the compound of Cr and Si as fine particles. This aging treatment increases strength and electrical conductivity. In order to obtain higher strength, cold rolling may be carried out before aging and / or after aging. Moreover, when cold rolling is performed after aging, stress removal annealing (low temperature annealing) may be performed after cold rolling.

In one embodiment, the Cu-Ni-Si-Co-Cr based copper alloy according to the present invention can have a 0.2% yield strength of 750 MPa or more and a conductivity of 50% IACS or more, and furthermore, a 0.2% yield strength of 800 It is MPa or more, and electrical conductivity can be 50% IACS or more, Furthermore, 0.2% yield strength can be 850 Mpa or more, and electrical conductivity can be 50% IACS or more.

The Cu-Ni-Si-Co-Cr based alloy according to the present invention can be processed into various new products, for example, plate, jaw, tube, rod and wire, and also Cu-Ni-Si based copper according to the present invention. The alloy can be used for electronic device parts such as lead frames, connectors, pins, terminals, relays, switches, and secondary battery materials that require high strength and high electrical conductivity (or thermal conductivity).

Example

Although the specific example of this invention is shown below, these Examples are provided in order to understand this invention and its advantage better, and it does not intend that invention is limited.

The copper alloy used for the Example of this invention added Sn, Zn, Mg, Mn, Co, and Ag suitably to the copper alloy which changed several content of Ni, Si, Co, and Cr as shown in Table 1, Has a composition. Moreover, the copper alloy used for a comparative example is a Cu-Ni-Si-Co-Cr type alloy which has a parameter outside the range of this invention, respectively.

The copper alloy of the various component compositions of Table 1 was solvent-processed at 1300 degreeC in the high frequency melting furnace, and was cast in the ingot of thickness 30mm. Subsequently, after heating this ingot at 1000 degreeC, it hot-rolled to 10 mm of plate | board thickness, and cooled rapidly. In order to remove the scale of a surface, it surface-treated to thickness 8mm, and was made into the plate of thickness 0.2mm by cold rolling. Next, the solution treatment was held at 800 to 1000 ° C for 120 seconds in accordance with the addition amount of Ni and Cr in an Ar gas atmosphere, and then the cooling rate was changed to cool to room temperature. The cooling rate was controlled by changing the gas flow rate injected to the sample after heating, and measuring the time to cool to 400 degreeC from the highest achieved temperature of the sample, and made it the cooling rate. The furnace cooling rate at the time of not inject | pouring gas was 5 degreeC / s, The cooling rate at the time of temperature-falling controlling heating output as an example of slowing down the cooling rate was 1 degreeC / s. It cold-rolled to 0.1 mm after that, and finally, aged at 400-550 degreeC over 1 to 12 hours according to addition amount, and aged in inert atmosphere, and prepared the sample.

Thus, the characteristics of strength and electrical conductivity were evaluated about each alloy obtained. About the strength, the tensile test in the rolling parallel direction was performed, 0.2% yield strength (YS: MPa) was measured, and about electrical conductivity (EC;% IACS), it calculated | required by the volume resistivity measurement by W bridge.

Evaluation of bendability performed the 90 degree bending process on the conditions which the ratio of a sample plate thickness and a bending radius becomes 1 using W-shaped metal mold | die. Evaluation evaluated the surface of a bending process part with the optical microscope, judged the case where a crack is not observed practically, and made it into (circle), and made the case where a crack was observed into x. In the fatigue test, positive stress was loaded in accordance with JIS Z 2273, and the stress (MPa) at which the number of repetitions to break was 10 ⁷ times was determined.

Observation of the Cr-Si compound was carried out by electrolytic polishing of the plate surface of the material, followed by FE-AES observation (JUMN-7800F, manufactured by Nihon Electronics Co., Ltd.), targeting particles having a size of 0.1 μm or more at a large number of points, and actually the surface layer thereof. When sputtering is carried out with Ar ⁺ to remove the adsorption elements (C, O) of, the Auger spectrum of each particle is measured, and the detected element is converted to the weight concentration as a semi-quantitative value by the sensitivity coefficient method. , Cr and Si were detected particles. The "composition (Cr / Si)", "size", and "dispersion density" of the Cr-Si compound are the average composition of Cr-Si particles having a size of 0.1 µm or more, and the diameter of the minimum circle, It was set as the average number in each observation visual field.

Table 1 and Table 2 show the results.

In Inventive Examples 1-24, since the dispersion density of a Cr-Si compound was 1 * 10 <^6> or less by Cr cooling rate, and the Cr / Si was the range of 1-5, favorable characteristic was obtained.

On the other hand, since Comparative Examples 1-10 did not contain Co, Comparative Examples 11 and 12 did not contain Cr, and therefore, strength and electrical conductivity could not be achieved in high dimensions. In Comparative Examples 13 and 14, since the cooling rate was slow, Cr-Si compound grew too much, sufficient strength was not obtained, and bending workability was also bad.

In Comparative Examples 15 and 16, since the cooling rate was fast, the Cr-Si compound did not grow and excess Si remained in the alloy, resulting in inferior strength and electrical conductivity. In Comparative Examples 17 and 18, because the aging temperature was high, the Cr-Si compound grew excessively, sufficient strength was not obtained, and bending workability was also poor. Moreover, Cu, Ni, etc. diffused in the coarse particle, Si density | concentration in particle fell, and Cr / Si ratio rose relatively. Since the density | concentration of Cr was too high in Comparative Examples 19 and 20, Cr-Si compound grew too much, sufficient strength was not obtained, and bending workability was also bad.

Claims (8)

Ni: 1.0-4.5 mass%, Si: 0.50-1.2 mass%, Co: 0.1-2.5 mass%, Cr: 0.003-0.3 mass%, The mass concentration ratio with respect to Si of the total mass of Ni and Co ([Ni + Co] / Si ratio) is 4

[Ni + Co] / Si

A copper alloy for an electronic material composed of 5 and residual Cu and unavoidable impurities, the dispersion density of which is 50 pieces / mm 2 or less for Cr-Si compounds having a size of more than 5 μm dispersed in the material, For the Cr-Si compound having a size of 0.1 μm to 5 μm to be dispersed, the atomic concentration ratio of Cr to Si in the dispersed particles is 1 to 5, and the dispersion density thereof exceeds 1 × 10 ⁴ pieces / mm 2, and 1 Copper alloy for electronic materials of less than 10 ⁶ pieces / mm 2. delete The method of claim 1,
The copper alloy for electronic materials which has a composition which satisfy | fills the following conditions or both conditions.
(1) 0.05-2.0 mass% of 1 type, or 2 or more types further chosen from Sn and Zn are contained,
(2) 0.001-2.0 mass% of 1 type, or 2 or more types chosen from Mg, Mn, Ag, P, As, Sb, Be, B, Ti, Zr, Al, and Fe further. delete A new product using the copper alloy according to claim 1. The electronic device component using the copper alloy of Claim 1. The new product using the copper alloy of Claim 3. The electronic device component using the copper alloy of Claim 3.