KR101159562B1 - Cu-ni-si-co-based copper alloy for electronic material, and method for production thereof - Google Patents

Abstract

Provided is a Cu—Ni—Si—Co based alloy in which generation of coarse second phase particles is suppressed. In the manufacturing process of Cu-Ni-Si-Co type alloy, (1) hot rolling is performed after heating at 950 degreeC-1050 degreeC for 1 hour or more, 15 degreeC / s is made into the temperature at the time of completion | finish of hot rolling to 850 degreeC or more. It is cooled above and (2) solution treatment is performed at 850 degreeC-1050 degreeC, and it cools to 15 degreeC / s or more. According to the present invention, a copper alloy for an electronic material containing Ni: 1.0 to 2.5% by mass, Co: 0.5 to 2.5% by mass, and Si: 0.30 to 1.20% by mass, the balance being made of Cu and unavoidable impurities, the particle diameter of which is 10 mu m There exists a 2nd phase particle exceeding and the copper alloy for electronic materials which is 50 piece / mm <2> or less in the cross section in which the 2nd phase particle whose particle diameter is 5 micrometers-10 micrometers parallel to a rolling direction is provided.

Cu-Ni-Si-Co Copper Alloy

Description

Cu-Ni-Si-CO-based copper alloy for electronic materials and manufacturing method thereof {CU-NI-SI-CO-BASED COPPER ALLOY FOR ELECTRONIC MATERIAL, AND METHOD FOR PRODUCTION THEREOF}

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

Copper alloys for electronic materials used in various electronic device components such as connectors, switches, relays, pins, terminals, and lead frames 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 demand level for copper alloys used in electronic component parts has been further advanced.

From the viewpoint of high strength and high electrical conductivity, the amount of precipitation hardening copper alloys is increasing in place of solid solution strengthened 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 solid solution 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 collon-based alloys are representative copper alloys having relatively high conductivity, strength, and bendability, and are currently actively developed in the industry. That is one of the alloys. In this copper alloy, strength and electrical conductivity can be improved by depositing fine Ni-Si-based intermetallic compound particles in a copper matrix.

In order to improve the better properties of the Colson alloy, various techniques have been developed such as addition of alloying elements other than Ni and Si, elimination of components that adversely affect the properties, optimization of crystal structure, optimization of precipitated particles, and the like.

For example, it is known that a characteristic improves by adding Co.

In Unexamined-Japanese-Patent No. 11-222641 (Patent Document 1), Co forms Ni and Si similarly to Ni, and improves mechanical strength, and when Cu-Co-Si system ages, Cu-Ni Both mechanical strength and conductivity are slightly better than that of the Si-based alloy. And it is described that you may select Cu-Co-Si type | system | group or Cu-Ni-Co-Si type | system | group if cost-permissible.

Japanese Laid-Open Patent Publication No. 2005-532477 (Patent Document 2) discloses, by weight, nickel: 1% to 2.5%, cobalt 0.5% to 2.0%, silicon: 0.5% to 1.5%, and the balance of copper and inevitable impurities. And annealed copper alloys having a total content of nickel and cobalt of 1.7% to 4.3% and a ratio (Ni + Co) / Si of 2: 1 to 7: 1, and the annealed copper alloy is 40% IACS. It is described as having conductivity exceeding that. Cobalt is described in combination with silicon to form silicides effective for age hardening in order to limit particle growth and improve softening resistance. If the cobalt content is less than 0.5%, precipitation of the cobalt-containing silicide second phase is insufficient. When the minimum cobalt content of 0.5% and the minimum silicon content of 0.5% are combined, the particle size of the alloy after solutionization is maintained at 20 microns or less. When the cobalt content exceeds 2.5%, it is described that excess second phase particles precipitate, resulting in a decrease in workability, and imparting undesirable ferromagnetic properties to the copper alloy.

[Ni+Co]/Si

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

Ni/Co

약 2 인 전자 재료용 구리 합금이 기재되어 있다.International Publication No. 2006/101172 pamphlet (Patent Document 3) describes that the strength of a Cu-Ni-Si-based alloy containing Co is dramatically improved under certain compositional conditions. Specifically, Ni: about 0.5 to about 2.5% by mass, Co: about 0.5 to about 2.5% by mass, and Si: about 0.30 to about 1.2% by mass, and are composed of the balance Cu and unavoidable impurities, and in the alloy composition The mass concentration ratio ([Ni + Co] / Si ratio) to Si of the total mass of Ni and Co is about 4

[Ni + Co] / Si

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

Ni / Co

Copper alloys for electronic materials that are about two are described.

In addition, when the cooling rate after heating is consciously increased in the solution treatment, the strength-improving effect of the Cu-Ni-Si-based copper alloy is further exhibited. Therefore, it is effective to cool the cooling rate at about 10 ° C or more per second. It is described.

It is also known to control coarse inclusions in the copper matrix.

In Japanese Unexamined Patent Publication No. 2001-49369 (Patent Document 4), after adjusting components of a Cu-Ni-Si-based alloy, Mg, Zn, Sn, Fe, Ti, Zr, Cr, Al, P, It is described that a suitable material can be provided as a copper alloy for electronic materials by containing Mn, Ag, Be, and controlling and selecting manufacturing conditions to control the distribution of inclusions, precipitates, oxides, and the like in the matrix. have. Specifically, it contains 1.0 to 4.8 wt% of Ni and 0.2 to 1.4 wt% of Si, the balance consists of Cu and unavoidable impurities, and the size of inclusions is 10 µm or less, and the size of 5 to 10 µm. A copper alloy for an electronic material excellent in strength and conductivity is described, wherein the number of inclusions is less than 50 pieces / mm 2 in a cross section parallel to the rolling direction.

The document also describes a method for controlling this because coarse crystals and precipitates of Ni-Si system may be generated during the solidification process during casting in semi-continuous casting. The inclusions are solid-dissolved in the matrix by performing hot rolling at a temperature of 800 ° C. or higher for 1 hour or more, and setting the end temperature to 650 ° C. or higher. However, when the heating temperature is 900 ° C or more, problems such as large scale generation and cracking during hot rolling occur, so the heating temperature is preferably 800 ° C or more and less than 900 ° C.

Patent Document 1: Japanese Patent Application Laid-Open No. 11-222641

Patent Document 2: Japanese Patent Publication No. 2005-532477

Patent Document 3: International Publication No. 2006/101172 Pamphlet

Patent Document 4: Japanese Unexamined Patent Publication No. 2001-49369

DISCLOSURE OF INVENTION

Problems to be solved by the invention

As described above, it is known that the addition of Co to the Cu-Ni-Si alloy improves the strength and conductivity, but the present inventors observe that the structure of the Cu-Ni-Si alloy added with Co is higher than the case where it is not added. It was found that many coarse second phase particles were scattered. This second phase particle mainly consists of a silicide of Co (silicide of cobalt). Coarse second phase particles not only contribute to strength, but also adversely affect bending workability.

Production of coarse second phase particles cannot be suppressed even if they are manufactured under conditions that can be suppressed as long as they are Cu-Ni-Si alloys containing no Co. That is, in Cu-Ni-Si-Co alloy, hot rolling is performed after heating for 1 hour or more at the temperature of 800 degreeC-900 degreeC as described in patent document 4, and an end temperature is 650 degreeC or more. Even by the method of suppressing the formation of coarse inclusions, coarse second phase particles mainly composed of Co silicide are not sufficiently dissolved in the matrix. Moreover, coarse 2nd phase particle | grains are not fully suppressed also by the method of making the cooling rate after heating high in the solution treatment as taught by patent document 3.

Then, an object of this invention is to provide the Cu-Ni-Si-Co type alloy by which generation | occurrence | production of coarse 2nd phase particle was suppressed. Moreover, another object of this invention is to provide the manufacturing method of such a Cu-Ni-Si-Co type alloy.

Means for solving the problem

MEANS TO SOLVE THE PROBLEM This inventor earnestly examined in order to solve the said subject, and discovered that generation | occurrence | production of coarse 2nd phase particle | grains can be suppressed by performing hot rolling and a solution treatment under specific conditions.

Specifically, in the manufacturing process of the Cu-Ni-Si-Co-based alloy,

(1) Hot rolling is performed after heating at 950 degreeC-1050 degreeC for 1 hour or more, making the temperature at the time of completion | finish of hot rolling 850 degreeC or more, and cooling to 15 degreeC / s or more, and

(2) The solution treatment is performed at 850 ° C to 1050 ° C, and cooled to 15 ° C / s or more,

By satisfying these two things, it turned out that it can suppress to the level which hardly affects strength and bending workability.

According to the manufacturing method, the 2nd phase particle whose particle diameter exceeds 10 micrometers can be removed, and the 2nd phase particle whose particle diameter is 5 micrometers-10 micrometers can be suppressed to 50 pieces / mm <2> or less. If it is such distribution conditions of a 2nd phase particle, it will hardly adversely affect strength or bending workability.

It is also known that the strength and conductivity can be improved by adding Cr. However, when Cr is added in the Cu-Ni-Si-Co alloy, coarse second phase particles are more likely to be produced. This is because Cr forms silicide and easily coarsens. Therefore, it is described in patent document 2 that chromium content should be 0.08% or less, for example. However, according to the manufacturing method of this invention, even if it adds the quantity of several times, formation of coarse Cr silicide can be suppressed. Therefore, the positive side by Cr addition becomes more prominent, and the characteristic of a Colson alloy can be improved further with the effect by Co addition.

The present invention completed on the basis of the above findings, in one aspect, contains Ni: 1.0 to 2.5% by mass, Co: 0.5 to 2.5% by mass, and Si: 0.30 to 1.20% by mass, and the balance consists of Cu and unavoidable impurities. As the copper alloy for electronic materials, there are no second phase particles having a particle size exceeding 10 μm, and the second material particles having a particle size of 5 μm to 10 μm are 50 pieces / mm 2 or less in a cross section parallel to the rolling direction. Is a copper alloy.

In one Embodiment, the copper alloy for electronic materials which concerns on this invention is 25 piece / mm <2> or less in the cross section in which the 2nd phase particle whose particle diameter is 5 micrometers-10 micrometers is parallel to a rolling direction.

In one embodiment, the copper alloy for electronic materials according to the present invention further contains up to 0.5% by mass of Cr.

In another embodiment, the copper alloy for an electronic material according to the present invention is further selected from the group consisting of Mg, P, As, Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn and Ag. It contains up to 2.0 mass% of at least 1 sort (s) of alloying elements in total.

In another aspect of the present invention,

-Melt casting the ingot having the desired composition,

-A process of performing hot rolling after heating at 950 ° C. to 1050 ° C. for at least 1 hour, cooling the temperature at the end of hot rolling to 850 ° C. or higher, and cooling the average cooling rate to 400 ° C. to 15 ° C./s or more,

Cold rolling process,

Performing a solution treatment at 850 ° C. to 1050 ° C., cooling the solution to an average cooling rate of 400 ° C. or higher at 15 ° C./s or more, and

-Voluntary cold rolling process,

Aging treatment process,

-Voluntary cold rolling process

It is a manufacturing method of the said copper alloy containing implementing in order.

In another aspect, the present invention is a new product using the copper alloy.

In yet another aspect, the present invention is an electronic component using the copper alloy.

Effects of the Invention

According to the present invention, since the formation of coarse second phase particles can be suppressed, it is possible to provide a Cu—Ni—Si—Co based alloy with less harmful effects. That is, since the side surface of the part by addition of Co and further Cr is controlled, the characteristic improvement effect with respect to the alloy which is a positive side becomes dominant. Specifically, the strength can be improved without sacrificing conductivity or bendability, for example.

Best Mode for Carrying Out the Invention

Distribution Conditions of Second Phase Particles

In the Colson-based alloy, by performing appropriate heat treatment, fine second phase particles mainly composed of intermetallic compounds are precipitated, and high strength can be achieved without deteriorating the electrical conductivity. However, when Co and further Cr are added, the second phase particles tend to coarsen.

Coarse second phase particles having a particle diameter of 1 µm or more not only contribute to the strength but also reduce the bending workability. In particular, for the second phase particles having a particle diameter of more than 10 µm, the bending workability is remarkably lowered, so the upper limit needs to be 10 µm. However, even if the 2nd phase particle whose particle diameter is 5 micrometers-10 micrometers does not fall within 50 pieces / mm <2>, strength and bending workability will not be impaired.

According to this invention, coarsening of the 2nd phase particle represented by Co silicide and Cr silicide can fully be suppressed, and the said requirement regarding distribution of 2nd phase particle can be satisfied. The particle diameter and number of 2nd phase particle can measure the cross section parallel to the rolling direction of a material by SEM observation after an etching. In this invention, the particle diameter of a 2nd phase particle means the diameter of the smallest circle | round | yen which surrounds the particle | grain when it observes SEM on such conditions.

Therefore, in one embodiment of this invention, the 2nd phase particle whose particle diameter exceeds 10 micrometers does not exist, and 50 pieces / of the 2nd phase particle whose particle diameter is 5 micrometers-10 micrometers are in a cross section parallel to a rolling direction. Mm 2 or less.

In one preferred embodiment of the present invention, there are no second phase particles having a particle diameter of more than 10 μm, and the second phase particles having a particle size of 5 μm to 10 μm are 25 particles / mm 2 in a cross section parallel to the rolling direction. It is as follows.

In one more preferable embodiment of the present invention, the second phase particles having a particle size of more than 10 μm do not exist, and the second phase particles having a particle size of 5 μm to 10 μm are 20 in a cross section parallel to the rolling direction. Mm 2 or less.

In one more preferable embodiment of the present invention, there are no second phase particles having a particle size exceeding 10 μm, and the second phase particles having a particle size of 5 μm to 10 μm are 15 in a cross section parallel to the rolling direction. / Mm2 or less.

In this invention, although a 2nd phase particle mainly shows a silicide, it is not limited to this, The crystallization which arises in the solidification process of melt casting, the precipitate which arises in the subsequent cooling process, and the cooling process after hot rolling generate | occur | produce Precipitates, precipitates generated in the cooling process after solution treatment, and precipitates generated in the aging treatment process.

Ni, Co and Si addition amount

Ni, Co, and Si can form an intermetallic compound by performing appropriate heat processing, and can attain high strength, without degrading electrical conductivity.

If the added amounts of Ni, Co and Si are less than 1.0 mass% of Ni, less than 0.5 mass% of Co, and less than 0.3 mass% of Si, respectively, desired strength cannot be obtained. In contrast, more than 2.5 mass% of Ni and 2.5 mass of Co. If it is more than% and more than Si: 1.2% by mass, the strength can be increased, but the electrical conductivity is significantly lowered, and the hot workability is deteriorated. Therefore, the addition amounts of Ni, Co, and Si were made into Ni: 1.0-2.5 mass%, Co: 0.5-2.5 mass%, and Si: 0.30-1.2 mass%. Preferably, they are Ni: 1.5-2.0 mass%, Co: 0.5-2.0 mass%, Si: 0.5-1.0 mass%.

Amount of Cr

Cr can be precipitated in Cr base alone or as Cr silicide which is a compound with Si by performing appropriate heat treatment, and the electrical conductivity can be raised without impairing strength. Therefore, you may add 0.5 mass% of Cr to the Cu-Ni-Si-Co type alloy which concerns on this invention at the maximum. However, if it is less than 0.03 mass%, the effect is small, and if it exceeds 0.5 mass%, since it will become undissolved particle which does not contribute to reinforcement, and workability will be impaired, Preferably it is 0.03-0.5 mass%, More preferably, 0.1-0.3 mass% is added.

Other additional elements

In addition, Mg, P, As, Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn and Ag have various effects by adding a predetermined amount. The effect of improving the manufacturability, such as improvement of workability, plating property and hot workability by miniaturization of ingot structure, is also appropriately added to the Cu-Ni-Si-Co-based alloy according to the present invention depending on the required properties. can do. In such a case, the total amount is at most 2.0 mass%, preferably 0.001 to 2.0 mass%, more preferably 0.01 to 1.0 mass%. On the contrary, if the total amount of these elements is less than 0.001% by mass, the desired effect cannot be obtained. If the total amount of these elements exceeds 2.0% by mass, the lowering of the electrical conductivity and the deterioration of manufacturability are remarkable, which is not preferable.

Manufacturing method

In the general manufacturing process of a Colson-type copper alloy, the raw material, such as electric copper, Ni, Si, Co, etc., is melt | dissolved using an atmospheric melting furnace first, and the molten metal of a desired composition is obtained. And this molten metal is cast into an ingot. Thereafter, hot rolling is carried out, and cold rolling and heat treatment are repeated to finish with a rough or foil having a desired thickness and properties. Heat treatment includes a solution treatment and an aging treatment. In solution treatment, it heats at high temperature of about 700-1000 degreeC, Ni-Si type compound and Co-Si type compound are solid-solution in Cu base material, and simultaneously recrystallize Cu base material. The solution treatment may also serve as hot rolling. In the aging treatment, a compound of Ni and Si and a compound of Co and Si precipitated as a fine particle are heated at a temperature in the range of about 350 to about 550 ° C. for at least 1 hour, and dissolved in the solution treatment. This aging treatment increases strength and electrical conductivity. In order to obtain higher strength, cold rolling may be performed before and / or after aging. Moreover, when cold rolling is performed after aging, strain removal annealing (low temperature annealing) may be performed after cold rolling.

Between each of the above steps, grinding, polishing, shot blast pickling and the like for removing the oxide scale of the surface are appropriately performed.

Although the copper alloy which concerns on this invention goes through said manufacturing process, in order to prevent the coarsening of 2nd phase particle | grains, it is important to carry out strictly control of a hot rolling and a solution treatment. Coarse precipitates are inevitably generated in the solidification process during casting, and coarse precipitates are inevitably generated in the cooling process. Therefore, in the subsequent process, it is necessary to solidify these 2nd phase particle | grains in a mother phase, but when hot rolling is performed after hold | maintaining at 950 degreeC-1050 degreeC for 1 hour or more, and the temperature at the time of completion | finish of hot rolling shall be 850 degreeC or more. Even in the case of addition of Co, Co, and Cr, solid solution can be employed in the mother phase. The temperature condition of 950 ° C or higher is a high temperature setting as compared with the case of other Colson-based alloys. When the holding temperature before hot rolling is less than 950 degreeC, solid solution is inadequate, and when it exceeds 1050 degreeC, there exists a possibility that a material may melt | dissolve. In addition, when the temperature at the end of hot rolling is less than 850 ° C, the solid solution precipitates again, so that high strength cannot be obtained.

Even if the second phase particles are dissolved, silicides of Cr and / or Co are easily precipitated when the cooling rate is low in the cooling process after the end of hot rolling. If such a structure is subjected to heat treatment (aging treatment) for the purpose of increasing the strength in a subsequent step, high strength cannot be obtained because it grows into a coarse precipitate that does not contribute to the strength by using the precipitate precipitated in the cooling process as a nucleus. . However, if the average cooling rate up to 400 ° C where precipitation of silicide is remarkable is high, specifically 15 ° C / s or more, precipitation of the silicide can be suppressed.

Also in the solution treatment, the second phase particles can be dissolved by setting the solution treatment temperature to be 850 ° C to 1050 ° C. The cooling after the solution treatment also needs to be accelerated for the above reason, and the average cooling rate up to 400 ° C. must also be 15 ° C./s or more. Even if the cooling rate after the solution treatment is controlled without controlling the cooling rate after hot rolling, coarse second phase particles cannot be sufficiently suppressed in subsequent aging treatment. The cooling rate after the hot rolling and the cooling rate after the solution treatment need to be controlled together.

The average cooling rate after the end of hot rolling and after the solution treatment is preferably 20 ° C / s or more.

Water cooling is the most effective way to speed up cooling. However, since the cooling rate changes with the temperature of the water used for water cooling, cooling can be made faster by managing water temperature. If the water temperature is 25 ° C or higher, the desired cooling rate may not be obtained. Therefore, it is preferable to maintain the temperature at 25 ° C or lower. When the material is placed in a tank where water is collected and water-cooled, the temperature of the water rises and is likely to be 25 ° C. or higher. It is desirable to always allow cold water to flow through the bath to prevent water temperature rise. In addition, the cooling rate can also be increased by expanding the water cooling nozzle or increasing the amount of water per unit time.

In the present invention, the term "average cooling rate up to 400 ° C" measures the time for which the material is cooled to 400 ° C at the hot rolling end temperature or the solution treatment temperature, and measures "(Solvation temperature -400) (° C) / cooling". The value (degreeC / s) calculated by time (s) "is called.

In addition, although the conditions of an aging treatment are useful for refinement | miniaturization of a precipitate, it does not matter with the conditions conventionally practiced, but it should care about setting temperature and time so that a precipitate may not coarsen. As an example of the conditions of an aging treatment, it is 1 to 24 hours in the temperature range of 350-550 degreeC, More preferably, it is 1 to 24 hours in the temperature range of 400-500 degreeC. In addition, the cooling rate after aging treatment hardly affects the magnitude of the precipitate.

The Cu-Ni-Si-Co-based alloy of the present invention can be processed into various new products, for example, plate, jaw, tube, rod, and wire, and also Cu-Ni-Si-Co-based according to the present invention The copper alloy can be used for electronic components such as lead frames, connectors, pins, terminals, relays, switches, and thin materials for secondary batteries.

Example

Although the Example of this invention is shown with a comparative example 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 of the various component compositions of Table 1 was melted at 1300 degreeC in the high frequency melting furnace, and was cast in the ingot of thickness 30mm. Subsequently, after heating this ingot to 1000 degreeC, it hot-rolled at various rising temperature (hot rolling finish temperature) to 10 mm of plate | board thickness, rapidly cooled to 400 degreeC at various cooling rates, and finally made it 100 degrees C or less. . Then, after surface-cutting to thickness 9mm in order to remove the scale of a surface, it was set as the plate of thickness 0.3mm by cold rolling. Next, the solution treatment was performed for 120 seconds at 950 degreeC, this was immediately cooled to 400 degreeC by various cooling rates, and finally made into 100 degrees C or less. Then, it cold-rolled to 0.15 mm, and finally, aged at 500 degreeC over 3 hours, in an inert atmosphere, and produced the test piece.

Thus, the characteristic evaluation of the distribution, strength, electroconductivity, and bending workability of a deposit was performed about each test piece obtained as follows.

After finishing 2nd phase particle | grains to mirror surface by the mechanical grinding | polishing using the diamond abrasive grain of 1 micrometer in diameter, the cross section parallel to the rolling direction of a material, 20 degreeC, 47 degrees Be (chlorine) chloride It was immersed for 2 minutes, stirring in ferric aqueous solution. By this etching treatment, the Cu moji was dissolved, and the second phase particles melted and remained. This cross section was observed 10 points arbitrary at the magnification of 1000 times (surveillance field of view 100x120 micrometers) using FE-SEM (electrolytic radiation scanning electron microscope: PHILIPS make), and the particle diameter of 5-10 micrometers was observed. The number per precipitate and the number of precipitates exceeding a particle diameter of 10 micrometers were counted, and the number per 1 mm <2> was computed. It was confirmed by analyzing using a EDS (energy dispersive X-ray analysis) of FE-SEM that a 2nd phase particle is a silicide, the typical form.

About strength, the tensile test of the rolling parallel direction was done, and 0.2% yield strength (YS: MPa) was measured.

The conductivity (EC;% IACS) was calculated by volume resistivity measurement by W bridge.

Evaluation of bending workability carried out the 90 degree bending process by the W bending test of Badway (bending axis is the same direction as a rolling direction) using the W-shaped metal mold | die on the conditions which the ratio of a sample plate thickness and a bending radius becomes 1. 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.

The results are shown in Table 1.

In Table 1, when the water cooling 3 which is the cooling condition after hot rolling is immersed in the water tank of 50 times quantity with respect to the volume (100000 kPa) of the test piece, when the water cooling 2 increases the quantity by 10% rather than the water cooling 3, the water cooling 1 is It is a case where the water quantity is increased by 20% from the water cooling 3, and the water temperature in the water tank is managed below 25 degreeC using flowing water. Air cooling is a case where it is left to cool in air.

Water cooling 3, which is the cooling condition during the solution treatment, is immersed in a water tank of 50 times the volume of the test piece (2500 kPa), water cooling 2 increases the water quantity 10% more than water cooling 3, and water cooling 1 is water cooling 3 It is a case where the water volume is increased by 20%, and the water temperature in the water tank is controlled to 25 degrees C or less using flowing water. Air cooling is a case where it is left to cool in air.

Each test piece is demonstrated below.

No. 1 ～ No. 22 is an embodiment of the present invention. It can be seen that the strength, conductivity, and bending workability are achieved in a high dimension.

No. 23 is an example in which Co and Cr were not added. In this case, it can be seen that coarse precipitates can be suppressed without strictly managing the cooling conditions after hot rolling or during the solution treatment.

No. 24 shows that even if only a small amount of Co is added, when a cooling condition and an elevated temperature are not managed, a considerable amount of precipitates are generated, that is, Co tends to generate precipitates.

No. 25 is No. A small amount of Cr was added to the test specimen of 24, and the amount of precipitates was further increased. In this respect, Cr is found to be particularly prone to precipitates.

No. 26 and No. 27 is an example in which cooling conditions after hot rolling are appropriate, but rising temperatures and cooling conditions during solution treatment are inappropriate.

No. 28 is an example in which the rise temperature is appropriate, but the cooling conditions after hot rolling and during the solution treatment are inappropriate.

No. 29 is an example in which the rising temperature and the cooling conditions at the time of solution treatment are appropriate, but the cooling conditions after hot rolling are inappropriate.

No. 30 is an example where the composition conditions are appropriate, but both the cooling conditions and the elevated temperature are inappropriate.

No. 31 is suitable for compositional conditions, but both cooling conditions and elevated temperatures are inadequate.

No. 32 is an example in which cooling conditions at the time of solution treatment are appropriate, but rising temperature and cooling conditions after hot rolling are inadequate.

No. 33 is No. As in 31, cooling conditions and rising temperatures are both inadequate examples, but the cooling rate after hot rolling is further reduced.

No. 34 is No. It is an example that the cooling rate after the solution treatment was further slowed against 33.

No. 35 is an example in which the amount of Co is excessive and both cooling conditions and rising temperatures are inappropriate.

No. 36 is No. It is an example in which a trace amount of Cr was further added to the 35 test piece.

Claims (7)

Ni: 1.0 to 2.5% by mass, Co: 0.5 to 2.5% by mass, Si: 0.30 to 1.20% by mass, optionally containing up to 0.5% by mass of Cr, voluntarily, Mg, P, As, At least one alloy element selected from the group consisting of Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn and Ag in total up to 2.0% by mass, with the balance being Cu and unavoidable impurities A copper alloy for an electronic material comprising: no second phase particles having a particle diameter of more than 10 μm, and second phase particles having a particle size of 5 μm to 10 μm are 50 particles / mm 2 or less in a cross section parallel to the rolling direction. Copper alloys for electronic materials. The copper alloy according to claim 1, wherein the second phase particles having a particle diameter of 5 µm to 10 µm are 25 particles / mm 2 or less in a cross section parallel to the rolling direction. As a manufacturing method of the copper alloy of Claim 1 or 2, -Melt casting the ingot having the desired composition, -A process of performing hot rolling after heating at 950 ° C. to 1050 ° C. for at least 1 hour, cooling the temperature at the end of hot rolling to 850 ° C. or higher, and cooling the average cooling rate to 400 ° C. to 15 ° C./s or more, Cold rolling process, Performing a solution treatment at 850 ° C. to 1050 ° C., cooling the solution to an average cooling rate of 400 ° C. or higher at 15 ° C./s or more, and -Voluntary cold rolling process, Aging treatment process, A method of producing a copper alloy, comprising performing a voluntary cold rolling step in sequence. The new copper article using the copper alloy of Claim 1 or 2. The electronic component using the copper alloy of Claim 1 or 2. delete delete