JP4937815B2 - Cu-Ni-Si-Co-based copper alloy for electronic materials and method for producing the same - Google Patents

Description

  The present invention relates to a precipitation hardening type copper alloy, and more particularly to a Cu—Ni—Si—Co based copper alloy suitable for use in various electronic device parts.

  Copper alloys for electronic materials used in various electronic equipment parts such as connectors, switches, relays, pins, terminals, lead frames, etc., can achieve both high strength and high conductivity (or thermal conductivity) as basic characteristics. Required. In recent years, high integration and miniaturization / thinning of electronic components have been rapidly progressing, and the level of demand for copper alloys used in electronic device components has been increased accordingly.

  From the viewpoint of high strength and high conductivity, the amount of precipitation hardening type copper alloys is increasing instead of conventional solid solution strengthened copper alloys such as phosphor bronze and brass as copper alloys for electronic materials. . In precipitation-hardened copper alloys, by aging the supersaturated solid solution that has undergone solution treatment, fine precipitates are uniformly dispersed, increasing the strength of the alloy and reducing the amount of solid solution elements in the copper. Electrical conductivity is improved. For this reason, a material excellent in mechanical properties such as strength and spring property and having good electrical conductivity and thermal conductivity can be obtained.

  Among precipitation hardening copper alloys, Cu-Ni-Si copper alloys, commonly called Corson alloys, are representative copper alloys that have relatively high electrical conductivity, strength, and bending workability, and are currently active in the industry. It is one of the alloys being developed. In this copper alloy, strength and conductivity can be improved by precipitating fine Ni—Si intermetallic compound particles in a copper matrix.

  In order to further improve the properties of the Corson alloy, various technological developments have been made such as addition of alloy components other than Ni and Si, elimination of components that adversely affect the properties, optimization of the crystal structure, and optimization of the precipitated particles. Yes.

For example, it is known that the characteristics are improved by adding Co.
In Japanese Patent Application Laid-Open No. 11-222641 (Patent Document 1), Co forms a compound with Si in the same manner as Ni, improves the mechanical strength, and Cu—Co—Si system is Cu-treated. -Slightly better mechanical strength and conductivity than Ni-Si alloys. In addition, it is described that a Cu—Co—Si system or a Cu—Ni—Co—Si system may be selected if allowed by cost.
In Japanese translations of PCT publication No. 2005-532477 (patent document 2), by weight, nickel: 1% to 2.5%, cobalt: 0.5% to 2.0%, silicon: 0.5% to 1.5%, And a wrought copper alloy consisting of the balance copper and inevitable impurities, wherein the total content of nickel and cobalt is 1.7% to 4.3%, and the ratio (Ni + Co) / Si is 2: 1 to 7: 1 The wrought copper alloy is said to have a conductivity greater than 40% IACS. Cobalt is said to combine with silicon to form silicides that are effective for age hardening in order to limit grain growth and improve softening resistance. When the cobalt content is less than 0.5%, the precipitation of the cobalt-containing silicide second phase becomes insufficient. Furthermore, when a minimum cobalt content of 0.5% and a minimum silicon content of 0.5% are combined, the grain size of the alloy after solution treatment is kept below 20 microns. It is described that when the cobalt content exceeds 2.5%, excess second phase particles precipitate, resulting in reduced workability and imparting undesirable ferromagnetic properties to the copper alloy. .
WO 2006/101172 pamphlet (Patent Document 3) describes that the strength of a Cu—Ni—Si based alloy containing Co is drastically improved under certain composition conditions. Specifically, Ni: about 0.5 to about 2.5 mass%, Co: about 0.5 to about 2.5 mass%, and Si: about 0.30 to about 1.2 mass%, It is composed of the balance Cu and unavoidable impurities, and the mass concentration ratio of Ni and Co in the alloy composition to Si ([Ni + Co] / Si ratio) is about 4 ≦ [Ni + Co] / Si ≦ about 5, A copper alloy for electronic materials is described in which the mass concentration ratio of Ni and Co (Ni / Co ratio) in the alloy composition is about 0.5 ≦ Ni / Co ≦ about 2.
In addition, when the cooling rate after heating is consciously increased in the solution treatment, the strength improvement effect of the Cu—Ni—Si based copper alloy is further exerted, so the cooling rate is about 10 ° C. or more per second. Is described as being effective.

It is also known to control coarse inclusions in the copper matrix.
In JP 2001-49369 A (Patent Document 4), after adjusting the components of the Cu—Ni—Si alloy, Mg, Zn, Sn, Fe, Ti, Zr, Cr, Al, Copper alloy for electronic materials by containing P, Mn, Ag, Be and controlling the distribution of inclusions such as precipitates, crystallized substances and oxides in the matrix by controlling and selecting the production conditions It is described that a suitable material can be provided. Specifically, it contains 1.0 to 4.8 wt% Ni and 0.2 to 1.4 wt% Si, the balance is made of Cu and inevitable impurities, and the size of inclusions is 10 μm or less. There is described a copper alloy for electronic materials having excellent strength and conductivity, characterized in that the number of inclusions having a size of 5 to 10 μm is less than 50 / mm ^{2 in} a cross section parallel to the rolling direction. Yes.
In addition, in this document, Ni-Si based coarse crystals and precipitates may be generated in the solidification process during casting in semi-continuous casting. Inclusions are hot-rolled after heating for 1 hour or more at a temperature of 800 ° C. or more, and are dissolved in the matrix by setting the end temperature to 650 ° C. However, if the heating temperature is 900 ° C. or more, a large amount The problem of generation of scale and cracking during hot rolling occurs, so the heating temperature should be 800 ° C. or higher and lower than 900 ° C. ”.

Japanese Patent Application Laid-Open No. 11-222641 JP 2005-532477 A International Publication No. 2006/101172 Pamphlet JP 2001-49369 A

  As described above, it is known that the strength and conductivity are improved by adding Co to the Cu—Ni—Si based alloy. When observing the above structure, it was found that more coarse second-phase particles were scattered than when not added. The second phase particles are mainly composed of Co silicide (cobalt silicide). Coarse second phase particles not only contribute to strength but also adversely affect bending workability.

  Generation of coarse second-phase particles cannot be suppressed even if manufactured under conditions that can be suppressed if it is a Cu-Ni-Si-based alloy containing no Co. That is, in the Cu-Ni-Si-Co-based alloy, as described in Patent Document 4, hot rolling is performed at a temperature of 800 ° C to 900 ° C for 1 hour or more, and the end temperature is set to 650 ° C or more. Even by the method for suppressing the formation of coarse inclusions, coarse second-phase particles mainly composed of Co silicide are not sufficiently dissolved in the matrix. Furthermore, coarse second phase particles are not sufficiently suppressed even by the method of increasing the cooling rate after heating in the solution treatment as taught in Patent Document 3.

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

The present inventor has intensively studied to solve the above problems, and it is possible to suppress generation of coarse second-phase particles by performing hot rolling and solution treatment under specific conditions. I found.
Specifically, in the manufacturing process of the Cu-Ni-Si-Co alloy,
(1) Hot rolling is performed after heating at 950 ° C. to 1050 ° C. for 1 hour or more, and the temperature at the end of hot rolling is set to 850 ° C. or more and cooled at 15 ° C./s or more.
(2) Solution treatment is performed at 850 ° C. to 1050 ° C. and cooled at 15 ° C./s or more.
By satisfying both, it was found that the strength and bending workability can be suppressed to a level that hardly has an adverse effect.

According to this production method, the second phase particles having a particle diameter exceeding 10 μm can be eliminated, and the second phase particles having a particle diameter of 5 μm to 10 μm can be suppressed to 50 particles / mm ² or less. With such distribution conditions of the second phase particles, the strength and bending workability are hardly adversely affected.

  It is also known that strength and conductivity can be improved by adding Cr. However, when Cr is added in a Cu—Ni—Si—Co alloy, coarse second phase particles are more easily generated. This is because Cr forms silicide and easily coarsens. Therefore, for example, Patent Document 2 describes that the chromium content should be 0.08% or less. However, according to the production method of the present invention, the formation of coarse Cr silicide can be suppressed even when several times the amount is added. Therefore, the positive side surface due to the addition of Cr becomes more prominent, and the characteristics of the Corson alloy can be further improved in combination with the effect of the addition of Co.

The present invention completed on the basis of the above knowledge, in one aspect, Ni: 1.0-2.5 mass%, Co: 0.5-2.5 mass%, Si: 0.30-1.20 mass% A second phase particle having a particle size of 5 μm to 10 μm, wherein the balance is Cu and the balance is Cu and inevitable impurities, and the second phase particle having a particle size of more than 10 μm does not exist. It is a copper alloy for electronic materials having a cross section parallel to the rolling direction of 50 pieces / mm ² or less.

In one embodiment of the copper alloy for electronic materials according to the present invention, the number of second phase particles having a particle size of 5 μm to 10 μm is 25 / mm ² or less in a cross section parallel to the 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 electronic materials 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. And at least one alloying element in total up to 2.0% by mass.

In another aspect of the present invention,
-Melting and casting an ingot having a desired composition;
A step of performing hot rolling after heating at 950 ° C. to 1050 ° C. for 1 hour or more, cooling to a temperature at the end of hot rolling of 850 ° C. or more, and an average cooling rate up to 400 ° C. of 15 ° C./s or more;
-A cold rolling process;
A solution treatment at 850 ° C. to 1050 ° C. and cooling at an average cooling rate up to 400 ° C. of 15 ° C./s or more;
-An optional cold rolling process;
-An aging treatment process;
-An optional cold rolling process;
It is a manufacturing method of the said copper alloy including performing these in order.

  In still another aspect of the present invention, a copper product using the above copper alloy.

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

  According to the present invention, since it is possible to suppress the generation of coarse second phase particles, it is possible to provide a Cu—Ni—Si—Co based alloy with less adverse effects. That is, since the negative side surface due to the addition of Co and further Cr is controlled, the characteristic improvement effect on the alloy which is the positive side surface becomes dominant. Specifically, for example, the strength can be improved without sacrificing conductivity or bending workability.

The distribution condition of the second phase particles In the Corson alloy, fine second phase particles mainly composed of intermetallic compounds are precipitated by performing an appropriate heat treatment, and the strength can be increased without deteriorating the conductivity. However, when Co and further Cr are added, the second phase particles are likely to be coarsened.

Coarse second phase particles having a particle size of 1 μm or more do not contribute to the strength but also lower the bending workability. In particular, for the second phase particles having a particle size exceeding 10 μm, the upper limit needs to be 10 μm in order to significantly reduce the bending workability. However, even if it is a 2nd phase particle | grain with a particle size of 5 micrometers-10 micrometers, if it is less than 50 piece / mm < ² >, intensity | strength and bending workability will not be impaired.

  According to the present invention, the coarsening of the second phase particles represented by Co silicide and Cr silicide can be sufficiently suppressed, and the above-described requirements regarding the distribution of the second phase particles can be satisfied. The particle size and number of the second phase particles can be measured by SEM observation after etching a cross section parallel to the rolling direction of the material. In the present invention, the particle size of the second phase particles refers to the diameter of the smallest circle that surrounds the particles when SEM observation is performed under such conditions.

Therefore, in one 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 50 particles / mm in a cross section parallel to the rolling direction. ² or less.

In a preferred 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 25 particles / mm ^{2 in} a cross section parallel to the rolling direction. It is as follows.

In a further preferred embodiment of the present invention, there are no second phase particles having a particle size of more than 10 μm, and the second phase particles having a particle size of 5 μm to 10 μm are 20 particles / mm in a cross section parallel to the rolling direction. ² or less.

In an even more preferred embodiment of the present invention, there are no second phase particles having a particle size of more than 10 μm, and there are 15 second phase particles having a particle size of 5 μm to 10 μm in a cross section parallel to the rolling direction. mm ² or less.

  In the present invention, the second phase particle mainly refers to silicide, but is not limited to this. Crystallized substances generated in the solidification process of melt casting and precipitates generated in the subsequent cooling process, after hot rolling It refers to precipitates generated in the cooling process, precipitates generated in the cooling process after solution treatment, and precipitates generated in the aging process.

Addition amounts of Ni, Co, and Si Ni, Co, and Si form an intermetallic compound by performing an appropriate heat treatment, and can increase the strength without deteriorating conductivity.
When the addition amounts of Ni, Co and Si are less than Ni: 1.0% by mass, Co: less than 0.5% by mass, and Si: less than 0.3% by mass, the desired strength cannot be obtained. If it exceeds 2.5% by mass, Co: more than 2.5% by mass, and Si: more than 1.2% by mass, the strength can be increased, but the conductivity is remarkably lowered, and the hot workability is further deteriorated. Therefore, the addition amounts of Ni, Co, and Si were set to Ni: 1.0 to 2.5 mass%, Co: 0.5 to 2.5 mass%, and Si: 0.30 to 1.2 mass%. Preferably, they are Ni: 1.5-2.0 mass%, Co: 0.5-2.0 mass%, Si: 0.5-1.0 mass%.

The added amount Cr of Cr can be deposited in the copper matrix by Cr alone or as Cr silicide which is a compound with Si, and the conductivity can be increased without impairing the strength. Therefore, you may add 0.5 mass% of Cr at maximum to the Cu-Ni-Si-Co-type alloy which concerns on this invention. However, if the amount is less than 0.03% by mass, the effect is small. If the amount exceeds 0.5% by mass, the solid solution particles do not contribute to strengthening and the workability is impaired. More preferably, 0.1 to 0.3% by mass is added.

Other additive elements Mg, P, As, Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn, and Ag show various effects by adding predetermined amounts, but complement each other In addition, there is an effect of improving not only strength and conductivity but also bendability, plating property, and hot workability improvement by refining the ingot structure, so the Cu—Ni— according to the present invention. One or more of these can be appropriately added to the Si—Co alloy depending on the required properties. In such a case, the total amount is at most 2.0 mass%, preferably 0.001-2.0 mass%, more preferably 0.01-1.0 mass%. On the other hand, if the total amount of these elements is less than 0.001% by mass, the desired effect cannot be obtained, and if it exceeds 2.0% by mass, the decrease in conductivity and the deterioration of manufacturability become remarkable.

Manufacturing Method In a general manufacturing process of a Corson copper alloy, first, an atmospheric melting furnace is used to melt raw materials such as electrolytic copper, Ni, Si, and Co to obtain a molten metal having a desired composition. Then, this molten metal is cast into an ingot. Thereafter, hot rolling is performed, and cold rolling and heat treatment are repeated to finish a strip or foil having a desired thickness and characteristics. Heat treatment includes solution treatment and aging treatment. In the solution treatment, heating is performed at a high temperature of about 700 ° C. to about 1000 ° C. to solid-dissolve the Ni—Si compound or Co—Si compound in the Cu matrix, and at the same time, the Cu matrix is recrystallized. The solution treatment may be combined with hot rolling. In the aging treatment, heating is performed for 1 hour or more in a temperature range of about 350 to about 550 ° C., and Ni and Si compounds and Co and Si compounds dissolved in the solution treatment are precipitated as fine particles. This aging treatment increases strength and conductivity. In order to obtain higher strength, cold rolling may be performed before and / or after aging. Moreover, when performing cold rolling after aging, strain relief annealing (low temperature annealing) may be performed after cold rolling.
Between the above steps, grinding, polishing, shot blast pickling and the like for removing oxide scale on the surface are appropriately performed.

  The copper alloy according to the present invention also undergoes the above manufacturing process, but it is important to strictly control the hot rolling and solution treatment in order to prevent the coarsening of the second phase particles. Coarse crystals are inevitably produced during the solidification process during casting, and coarse precipitates are inevitably produced during the cooling process. Therefore, in the subsequent process, it is necessary to dissolve these second phase particles in the matrix phase. However, hot rolling is performed after holding at 950 ° C. to 1050 ° C. for 1 hour or more, and the temperature at the end of hot rolling is set. If it is 850 degreeC or more, even if it is a case where Co and also Cr are added, it can be dissolved in a mother phase. The temperature condition of 950 ° C. or higher is a higher temperature setting than other Corson alloys. If the holding temperature before hot rolling is less than 950 ° C., solid solution is insufficient, and if it exceeds 1050 ° C., the material may be dissolved. Further, when the temperature at the end of hot rolling is less than 850 ° C., the dissolved element is precipitated again, so that high strength cannot be obtained.

  Even if the above-mentioned second phase particles are dissolved, if the cooling rate is low in the cooling process after the hot rolling is completed, silicide of Cr and / or Co is easily precipitated. When heat treatment (aging treatment) aimed at increasing the strength in such a structure is performed in a later step, high strength is obtained because it grows into a coarse precipitate that does not contribute to strength with the precipitate precipitated in the cooling process as a nucleus. I can't. However, if the average cooling rate up to 400 ° C. where the precipitation of the silicide is remarkable is high, specifically, 15 ° C./s or more, the precipitation of the silicide can be suppressed.

  Similarly, in the solution treatment, the second phase particles can be dissolved by setting the solution treatment temperature to 850 ° C. to 1050. The cooling after the solution treatment needs to be accelerated for the above reason, and the average cooling rate up to 400 ° C. must be 15 ° C./s or more. Even if only the cooling rate after the solidification treatment is controlled without managing the cooling rate after hot rolling, coarse second-phase particles cannot be sufficiently suppressed by the subsequent aging treatment. It is necessary to control both the cooling rate after hot rolling and the cooling rate after the solidification treatment.

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

  Water cooling is the most effective method for speeding up the cooling. However, since the cooling rate varies depending on the temperature of the water used for water cooling, the cooling can be further accelerated by managing the water temperature. Since the desired cooling rate may not be obtained when the water temperature is 25 ° C. or higher, it is preferably maintained at 25 ° C. or lower. When a material is placed in a tank in which water is stored and cooled with water, the temperature of the water rises and tends to be 25 ° C. or higher, so that the material is cooled in a mist (shower) at a constant water temperature (25 ° C. or lower). It is preferable to prevent the water temperature from rising by spraying it in the form of a mist or mist) or by allowing cold water to always flow through the water tank. The cooling rate can also be increased by adding water cooling nozzles or increasing the amount of water per unit time.

  In the present invention, the “average cooling rate up to 400 ° C.” means the time during which the material cools from the hot rolling finish temperature or solution treatment temperature to 400 ° C., and “(solution temperature−400) (° C.)”. / Cooling time (s) "means a value (° C / s) calculated.

  The conditions for the aging treatment may be those conventionally used as useful for refining the precipitates, but note that the temperature and time are set so that the precipitates do not become coarse. If an example of the conditions of an aging treatment is given, it will be 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. The cooling rate after the aging treatment hardly affects the size of the precipitates.

  The Cu—Ni—Si—Co based alloy of the present invention can be processed into various copper products, such as plates, strips, tubes, bars and wires, and the Cu—Ni—Si—Co based copper according to the present invention. The alloy can be used for electronic components such as lead frames, connectors, pins, terminals, relays, switches, and secondary battery foils.

  Examples of the present invention will be described below together with comparative examples, but these examples are provided for better understanding of the present invention and its advantages, and are not intended to limit the invention.

  Copper alloys having various component compositions shown in Table 1 were melted at 1300 ° C. in a high-frequency melting furnace and cast into an ingot having a thickness of 30 mm. Next, after heating this ingot to 1000 ° C., it is hot-rolled as various ascending temperatures (hot rolling end temperature) to a plate thickness of 10 mm, rapidly cooled to 400 ° C. at various cooling rates, and finally 100 ° C. It was as follows. Then, after surface chamfering to a thickness of 9 mm for removing scale on the surface, a plate having a thickness of 0.3 mm was formed by cold rolling. Next, a solution treatment was performed at 950 ° C. for 120 seconds, which was immediately cooled to 400 ° C. at various cooling rates, and finally made 100 ° C. or lower. Thereafter, it was cold-rolled to 0.15 mm and finally subjected to aging treatment in an inert atmosphere at 500 ° C. for 3 hours to produce a test piece.

  Each test piece obtained in this manner was subjected to the following evaluation of the characteristics of the precipitate distribution, strength, conductivity, and bending workability.

The second phase particles have a mirror-finished cross section parallel to the rolling direction of the material by mechanical polishing using diamond abrasive grains having a diameter of 1 μm, and then in a ferric chloride aqueous solution at 20 ° C. and 47 ° Be (Baume). For 2 minutes with stirring. By this etching treatment, the base material of Cu was dissolved, and the second phase particles remained undissolved and appeared. This cross section was observed at 10 arbitrary points at a magnification of 1000 times (monitoring field of view 100 × 120 μm) using an FE-SEM (electrolytic emission scanning electron microscope: manufactured by PHILIPS), and the number of precipitates having a particle size of 5 to 10 μm was determined. The number of precipitates having a particle size exceeding 10 μm was counted, and the number per 1 mm ² was calculated. It was confirmed by analyzing the typical form of the second phase particles by using FE-SEM EDS [energy dispersive X-ray analysis].

  For the strength, a tensile test in the rolling parallel direction was performed to measure 0.2% yield strength (YS: MPa).

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

  Evaluation of bending workability is based on a W-bending test of Badway (the bending axis is the same direction as the rolling direction) using a W-shaped mold and bending by 90 ° under the condition that the ratio of the sample plate thickness to the bending radius is 1. Was done. In the evaluation, the surface of the bent portion was observed with an optical microscope, and when the crack was not observed, it was judged that there was no problem in practical use, and the case where the crack was recognized was made x.

The results are shown in Table 1.

In Table 1, when water-cooled 3 which is a cooling condition after hot rolling is immersed in a 50-fold water tank with respect to the volume of the test piece (100,000 mm ³ ), water-cooled 2 has 10% more water than water-cooled 3 When increased, water cooling 1 is a case where the amount of water is increased by 20% compared to water cooling 3, and the water temperature in the water tank is controlled to 25 ° C. or lower using running water. Air cooling is the case of cooling in air.
When water-cooled 3 which is a cooling condition at the time of solution treatment is immersed in a water tank 50 times the amount of water (2500 mm ³ ) of the test piece, water-cooled 2 increases the amount of water by 10% compared to water-cooled 3 Water cooling 1 is a case where the amount of water is increased by 20% compared to water cooling 3, and the water temperature in the water tank is controlled to 25 ° C. or lower using running water. Air cooling is the case of cooling in air.

Each test piece is described below.
No. 1-No. 22 is an embodiment of the present invention. It can be seen that strength, conductivity, and bendability are achieved on a high dimension.
No. 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 solution treatment.
No. From FIG. 24, it can be seen that even if a small amount of Co is added, a considerable amount of precipitates are formed unless the cooling conditions and the rising temperature are controlled, that is, Co is likely to generate precipitates.
No. 25 is No. 25. In this example, a small amount of Cr was added to 24 test pieces, but the amount of precipitates was further increased. From this, it can be seen that Cr is particularly likely to produce precipitates.
No. 26 and no. No. 27 is an example in which the cooling conditions after hot rolling are appropriate, but the ascending temperature and the cooling conditions during solution treatment are inappropriate.
No. No. 28 is an example in which the rising temperature is appropriate, but the cooling conditions after hot rolling and during the solution treatment are inappropriate.
No. No. 29 is an example in which the rising temperature and the cooling conditions during the solution treatment are appropriate, but the cooling conditions after hot rolling are inappropriate.
No. No. 30 is an example in which the composition conditions are appropriate, but the cooling conditions and the rising temperature are both inappropriate.
No. Although the composition conditions of No. 31 are appropriate, both the cooling conditions and the rising temperature are inappropriate.
No. No. 32 is an example in which the cooling conditions during the solution treatment are appropriate, but the ascending temperature and the cooling conditions after hot rolling are inappropriate.
No. 33 is No. 33. Similar to 31, both the cooling conditions and the rising temperature are inappropriate, but the cooling rate after hot rolling is further reduced.
No. 34 is No. 34. This is an example in which the cooling rate after the solution treatment is further reduced with respect to 33.
No. 35 is an example in which the amount of Co is excessive and the cooling condition and the rising temperature are both inappropriate.
No. No. 36 is No. 36. This is an example in which a small amount of Cr is further added to 35 test pieces.

Claims (7)

An electronic material containing Ni: 1.0 to 2.5% by mass, Co: 0.5 to 2.5% by mass, Si: 0.30 to 1.20% by mass, the balance being Cu and inevitable impurities Copper alloy for use, wherein 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 50 pieces / mm ² or less in a cross section parallel to the rolling direction. Copper alloy for electronic materials. ^2. 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.   The copper alloy according to claim 1 or 2, further comprising up to 0.5% by mass of Cr.   Furthermore, a total of at least one alloy element selected from the group consisting of Mg, P, As, Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn, and Ag is up to 2.0 mass% in total. The copper alloy as described in any one of Claims 1-3 contained. -Melting and casting an ingot having a desired composition;
A step of performing hot rolling after heating at 950 ° C. to 1050 ° C. for 1 hour or more, cooling to a temperature at the end of hot rolling of 850 ° C. or more, and an average cooling rate up to 400 ° C. of 15 ° C./s or more;
-A cold rolling process;
A solution treatment at 850 ° C. to 1050 ° C. and cooling at an average cooling rate up to 400 ° C. of 15 ° C./s or more;
-An optional cold rolling process;
-An aging treatment process;
-An optional cold rolling process;
The manufacturing method of the copper alloy as described in any one of Claims 1-4 including performing these in order.   A rolled copper product using the copper alloy according to any one of claims 1 to 4.   The electronic component using the copper alloy as described in any one of Claims 1-4.