JP6088741B2 - Copper alloy material excellent in mold wear resistance during pressing and manufacturing method thereof - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a copper alloy material and a method for manufacturing the same, and is applied to lead frames, relays, switches, sockets, etc. in addition to connectors and terminal materials such as in-vehicle components such as EV and HEV, peripheral infrastructure, and photovoltaic power generation systems. The present invention relates to a copper alloy material and a manufacturing method thereof.

  As characteristic items required for automotive parts such as EV and HEV, connectors and terminal materials for peripheral infrastructure and solar power generation systems, and other copper alloy materials used for lead frames, relays, switches, sockets, etc. For example, conductivity and stress relaxation resistance can be mentioned. In recent years, each system has been increased in voltage and used in high temperatures, and there has been a demand for reduction in energization loss and improvement in the reliability of terminals in a high temperature environment. Accordingly, the required levels of conductivity and stress relaxation resistance are simultaneously increasing.

  On the other hand, such copper alloy materials are also required to have pressability. In the pressing process at the time of manufacturing the terminal, as the number of presses increases, the mold gradually wears and eventually the dimensions of the punched material cannot be maintained, so that the mold needs to be replaced. Therefore, in order to increase the productivity of terminals and the like that are products, it is necessary to sufficiently secure the number of times of die punching until replacement by providing a copper alloy material with good pressability.

  Cu-Cr alloys are known to have moderate strength and high conductivity. Patent Documents 1 and 2 attempt to improve heat resistance by adding Ti, P, Fe, Co, Ni, or adding Al, Mg. Moreover, it is known that Cu-Cr alloys have poor pressability in the past, and the pressability is improved by adding Pb or Se (Patent Documents 3 and 4). Further, as disclosed in Patent Document 5, it is known that the characteristics of the Cu—Cr alloy can be improved by controlling the compound size.

Japanese Patent No. 4132451 JP-A-61-99642 JP-A-8-13066 JP-A-11-323463 JP 59-193233 A

  Terminals that are energized with a large current, such as EV batteries, junction boxes, charging ports, and PV modules, have plate thickness, and mold wear occurs more frequently than conventional thin strips, so there is a need for improvement. It is getting stronger. To date, Cu-Cr alloys with improved pressability have added Pb and Se as additive elements as described above, and environmental considerations are insufficient.

  In view of the problems as described above, the object of the present invention is to provide connectors and terminals for automobiles, such as EV, HEV-mounted parts, peripheral frames, lead frames such as solar power generation systems, connectors, and terminal materials. Copper alloy material with excellent strength, conductivity and stress relaxation resistance suitable for materials, relays, switches, etc., and excellent die wear resistance during pressing without adding Pb or Se, and its manufacture It is to provide a method.

The present inventors have studied and studied copper alloy materials suitable for electric / electronic component applications, and in the structure of the product, the density of the second phase A having a diameter size of 0.01 μm or more and less than 0.1 μm. In a Cu-Cr alloy material in which the density of the second phase B having a diameter of 0.1 to 5 μm exceeds 1 × 10 ⁶ pieces / mm ² and the density of the second phase B exceeds 1 × 10 ³ pieces / mm ² The present inventors have found that it is excellent in strength, conductivity, and stress relaxation resistance and further improves pressability.

That is, the said subject was solved by the following invention.
(1) 0.1 to 1.2 mass% of Cr, 0.15 mass% or less of Mg, 0.06 mass% or less of Ti, 0.10 mass% or less of Zr, 0.20 mass% or less of Zn, Fe 0.05 mass% or less, Sn is 0.25 mass% or less, Ag is 0.10 mass% or less, and Si is contained in a total amount of 0.005 to 0.5 mass%, and the balance. Consists of copper and inevitable impurities,
From the electron image or transmission image of an electron microscope (for example, SEM, TEM), the major axis having the largest diameter and the minor axis having the smallest diameter pass through the center of gravity of the particle, and the major axis / minor axis of each particle is measured. The aspect ratio as a ratio is calculated, and when the average value of the major axis and the minor axis is the diameter size, the second phase having a diameter size of 0.01 μm or more and less than 0.1 μm is designated as the second phase A, 0.1 to 5 μm. When the second phase having a diameter size of 2 is the second phase B, the density of the second phase A exceeds 1 × 10 ⁶ pieces / mm ² and the density of the second phase B is 1 × 10 ³ pieces / mm ^2. Exist beyond
A copper alloy material characterized by a tensile strength exceeding 500 MPa, an electrical conductivity exceeding 75% IACS, and a stress relaxation rate being less than 25%.
(2) The copper alloy material according to (1), wherein an average value obtained by dividing the major axis by the minor axis is 10 to 50 with respect to the aspect ratio of the second phase B.
(3) A method for producing a copper alloy material according to (1) or (2),
To the copper alloy raw material having an alloy composition to give the copper alloy material, casting [step 1], homogenization heat treatment step [step 2], hot working step [step 3], after cold working, heat treatment and cold as necessary In performing the processing step [Step 4] that repeats processing, the aging heat treatment step [Step 5], the final cold rolling step [Step 6], and the strain relief annealing step [Step 7]
The homogenization heat treatment [Step 2] is performed at 900 to 1000 ° C. for 0.5 to 8 hours,
A method for producing a copper alloy material in which the total rolling rate after casting [Step 1] is 90 to 99.95% and the processing rate in the final cold rolling step [Step 6] is 0 to 30%.

  The copper alloy material centering on the Cu-Cr system of the present invention is particularly excellent in stress relaxation resistance, has a medium strength and high conductivity, and is equipped with automotive components such as EV and HEV, peripheral infrastructure and solar power. It is suitable for lead frames, connectors, terminal materials, etc. for photovoltaic systems. Moreover, it has an excellent effect of suppressing the amount of die wear during pressing, and the productivity in pressing is high.

A preferred embodiment of the copper alloy material of the present invention will be described in detail. Here, the “copper alloy material” is a material obtained by processing a copper alloy material (having a predetermined alloy composition before processing) into a predetermined shape (for example, plate, strip, foil, bar, wire, etc.) Means. In addition, a board | plate material and a strip are demonstrated below as embodiment.
In addition, the copper alloy material of this invention has prescribed | regulated the characteristic the compound distribution state in a structure | tissue, and its shape. However, as long as it has such characteristics as a copper alloy material, the shape of the copper alloy material is not limited to a plate material or a strip material.

In the present invention, the second phase is a phase in which an additive element is precipitated and crystallized from the copper matrix phase (first phase). If the additive element is in a transformed state other than a solid solution state, it can be called a second phase. That is, the second phase is a compound or simple substance formed by reaction of an additive element (Cr, Ti, Zr, Fe, Si, etc.), and is not limited to an intermetallic compound. For example, specifically CrCr, CrZr, CrSi and the like are Cr-based compounds. Naturally, the crystallized / precipitated Cr alone is also included in the second phase.
The formation of this second phase is promoted by precipitation in adjustment of alloy composition, homogenization heat treatment step, hot rolling step, each heat treatment step (or a combination of one or more of these), etc. in alloy production. The heat treatment can be performed at a temperature range of 300 ° C. or higher for several hours.
The second phase A and the second phase B described below may be the same or different as long as their sizes are different.

(Additive element: Cr)
The present invention is directed to a Cu—Cr alloy material in order to ensure strength and conductivity. Here, Cr contributes two by precipitation.
One is conventional precipitation hardening, and a second phase (hereinafter referred to as second phase A) having a diameter size of 0.01 μm or more and less than 0.1 μm contributes. Further, since a Cr-based compound of this size also contributes to stress relaxation resistance, if it is too small, the heat resistance may be greatly reduced.
The diameter size in the present invention refers to the measurement of the major axis with the largest diameter and the minor axis with the smallest diameter passing through the center of gravity of the particle from an electron image or transmission image of an electron microscope (SEM, TEM). After calculating the major axis / minor axis (aspect ratio) of each particle, the average value of the major axis and the minor axis is obtained.

The other is the effect of suppressing the amount of die wear during pressing (pressability), and a compound having a size of 0.1 to 5 μm (hereinafter referred to as compound B) contributes. All of the compounds contain Cr as a component, and may contain other additive elements and Cu. Here, Patent Document 5 also shown in the prior art document describes an invention in which the same Cu—Cr alloy is used as a component, and the structure has 100 to 100,000 / mm ² of a compound having a diameter of 0.10 to 50 μm. Show. As shown in Examples later, the alloy produced by the process of Patent Document 5 does not have the compound density in the same document, and when the number of compounds is controlled to be within the above range by another process, The strength, conductivity, heat resistance (stress relaxation resistance), and pressability exhibited by the present invention are not simultaneously established. In the present invention, it is particularly important that the second phase A having a smaller size is specified with respect to Patent Document 5, and this contributes effectively to the invention, but is greatly different from Patent Document 5. .

  If the size of the second phase is less than 0.01 μm, it does not contribute to both strength and pressability. If it is 0.01 μm or more and less than 0.1 μm, it contributes to strength but does not contribute to pressability. When it is 0.1 to 5 μm, it contributes to pressability but does not contribute to strength. If it exceeds 5 μm, it does not contribute to both strength and pressability, and the presence of the second phase may cause cracking during the manufacturing process, resulting in deterioration of properties such as toughness and fatigue. Sometimes it brings. In addition, if the second phase outside the specification is formed, the second phase having a predetermined required size cannot be formed, and the material strengthening or pressability improvement cannot be expected.

The number of the second phases of both A and B has a relationship that when one is larger, the other is smaller at a certain precipitation amount. The presence of a certain amount of the second phase of both sizes is necessary in order to sufficiently satisfy both characteristics. The density of the second phase A exceeds 1 × 10 ⁶ pieces / mm ² , and the second phase B Density exceeds 1 × 10 ³ / mm ² . Preferably, A is present at a density of 3 × 10 ^{6 to} 5 × 10 ¹² pieces / mm ² , and B is present at a density exceeding 1 × 10 ³ pieces / mm ² and not more than 5 × 10 ⁵ pieces / mm ^2. The alloy material is improved in both strength and pressability in terms of properties while maintaining the same properties as conventional Cu-Cr alloys.

  In the present invention, the Cr content is in the range of 0.1 to 1.2 mass%. The greater the content, the greater the effective size second phase, and the greater the effect of improving strength and die wear during pressing. If the content is small, the total amount of the second phase becomes less than the effective amount, and sufficient characteristics cannot be improved. On the other hand, if the content is too large, a second phase of 5 μm or more may be formed, or even if it is an effective size, the total amount may exceed the specified range, and both may cause cracking during the manufacturing process. It may cause deterioration of properties such as toughness and fatigue.

(Additive elements: Mg, Ti, Zr, Zn, Fe, Sn, Ag, Si)
Each of these elements plays the following role.
Mg and Sn are solid solution, and part of Ti and Si are solid solution, and Zr, Ti and Si form a second phase to improve the stress relaxation resistance and contribute to strengthening. Some solid solution elements have a greater effect on stress relaxation than when they are added at the same time, and are particularly effective when Sn and Mg are added simultaneously, respectively.

In addition, these above-mentioned elements can bring about a drag effect that hinders the movement of the grain boundary in the solid solution state, which is effective for the growth of the average grain within this rule. Therefore, rapid grain coarsening can be suppressed, and it can contribute effectively to control of the coefficient of variation.
In any case, if the added amount is small, the effect cannot be obtained, and if the added amount is large, the formation of the second phase has a significant adverse effect on the productivity during melting, casting and hot rolling, and is in a solid solution state. Decreases the conductivity.

  The content in the copper alloy material is 0.1 to 0.8 mass% for Cr, and 0.005 to 0.5 mass% in total for other additive elements. For Cr and other elements forming the second phase, the second phase contributing to strength and the second phase contributing to pressability improvement are controlled by controlling the content and heat treatment conditions in the process conditions. . Further, by controlling the crystal grain size and its coefficient of variation by the drag effect by the element in the solid solution state, it is possible to contribute to the improvement of the stress relaxation resistance.

(Production method)
Next, the manufacturing method (control method of the compound A and the compound B) of the copper alloy material of this invention is demonstrated. Here, a plate material (strip material) of a precipitation type copper alloy will be described as an example, but it can be developed into a solid solution type alloy material utilizing precipitation. The thickness of the plate material (strip material) of the present invention is not particularly limited, but is preferably 0.05 to 5 mm.

  The alloy of the present invention is heated at 900 ° C. to 1000 ° C. for 0.5 to 8 hours as a homogenization heat treatment [Step 2] after casting [Step 1]. By this heat treatment, primary control of the size and density of the crystallized product and precipitates produced by casting is performed, and the size and density of the second phases A and B can be satisfied by the subsequent steps. Conventionally, this homogenization heat treatment has been performed by high-temperature heat treatment in a solid solution state as much as possible. However, in this application, the homogenization heat treatment is performed in a low temperature range in order to solve the problem.

  It should be noted that, for example, in the case where Cr is added in an amount exceeding 0.5 mass%, which does not contribute to the strength, for example, the second phase corresponding to the second phase B has a sufficient density even if it exceeds 1000 ° C. Remains. Therefore, in order to promote the solid solution for the purpose of strengthening, it is possible to perform a treatment at over 1000 ° C. The upper limit of the processing temperature is about 1050 ° C., at which the material strength is extremely lowered and the ingot shape is largely deformed during the heat treatment or in the subsequent hot rolling.

After the homogenization heat treatment is completed, general hot rolling is performed [Step 3], and cold rolling and, if necessary, heat treatment and cold rolling are repeated [Step 4]. Thereafter, an aging heat treatment step [Step 5], a final cold rolling step [Step 6], and a strain relief annealing step [Step 7] are performed. At this time, when the rolling ratio from the end of casting to the product sheet thickness is 90 to 99.95% as a whole, the area ratio of the fractured surface is less affected by the wear of the mold than the sheared surface during pressing. Since it becomes higher, the pressability is further improved. In addition, the precipitation density can be increased by introducing an appropriate strain, so that strengthening can be expected. In this state, the Cr-based eutectic compound of 0.1 to 5 μm and the coarse precipitate pass through the center of gravity of the particle, and the value obtained by dividing the major axis with the largest diameter by the minor axis with the smallest diameter (aspect ratio). ) Is preferably 10 to 50. The method for measuring the aspect ratio has been described in the measurement of the diameter size.
When this rolling rate is lower than 90%, the pressability may be deteriorated or the strength may be lowered. If the rolling rate is higher than 99.95%, the possibility that the material is destroyed may be remarkably increased.

In the conventional process of precipitation type alloys such as Cu-Cr, the process conditions for maintaining the solid solution state until the final recrystallization solution treatment or aging heat treatment are common. It is usual to make a solid solution.
As a method for producing the copper alloy material of the present invention, casting, homogenization heat treatment, hot working, cold working, and then heat treatment and cold rolling are repeated as necessary. In the homogenization heat treatment after casting, the conventional manufacturing method performs heat treatment at a high temperature in order to obtain a better solid solution state, so that the second phase formed at the time of casting is dissolved or minimal heating is performed, In general, in the present invention, a certain amount of solid solution is produced in order to form a second phase that does not excessively dissolve the crystallized product and effectively contributes to strength in later aging. It is necessary to perform heat treatment at 900 to 1000 ° C. for 0.5 to 8 hours. In the case where the Cr addition amount is 0.5 mass% or more, the crystallized substance and the coarse compound remain even if the heat treatment condition is higher, so that the second phase B remains within the specified range. You may perform a solid solution process by 1000-1050 degreeC heat processing.

  The combination of the subsequent cold rolling and heat treatment is arbitrary, but a process for precipitating the second phase A at a density within the scope of the invention (aging heat treatment step) is required for the remaining Cr in solid solution. For example, precipitation is performed by heat treatment at 300 to 600 ° C. for several minutes to several hours to obtain a compound density within a specified range. In the aging heat treatment step, heat treatment is usually performed for about 2 hours, but it can be strengthened by performing heat treatment for longer than 2 hours at a lower temperature. In particular, the present invention material having a coarse compound is an effective means because its fine precipitation amount is limited.

The processing rate in the final cold rolling step is 0 to 30% with respect to the plate pressure in the immediately preceding step (plate pressure after aging heat treatment) . This rolling step is performed so that the total rolling rate (rolling rate from the initial plate pressure) is 90 to 99.95%. If the rolling ratio of the final cold rolling process is close to 0%, the overall strain amount should be reduced as much as possible to maintain the electrical conductivity at a high level or to improve the stress relaxation resistance. Can do. On the other hand, if the rolling rate is close to 30%, it can be further strengthened. In addition, although it is outside the present invention, when the conductivity and stress relaxation resistance may be sacrificed to some extent, rolling is performed at a processing rate of 30% or more in the final cold rolling step to further strengthen. Is also possible.

  For example, the strain relief annealing is preferably performed at 400 to 800 ° C. for about 5 seconds to 180 seconds when performed in a running furnace, and when performed in a batch furnace for about 10 to 180 minutes at 250 to 500 ° C.

  The copper alloy material of the present invention manufactured as described above has a characteristic that exceeds the stress relaxation resistance of the conventional alloy having the same composition, and includes in-vehicle components such as EV and HEV, peripheral infrastructure, and solar power generation system. The characteristics required for lead frames, connectors, terminal materials, etc. can be satisfied.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

<Example 1, comparative example 1>
After the raw material was melted, it was cast into a book mold having a size of 120 mmw × 30 to 200 mmt × 180 mmL, and a sample was prototyped under the following conditions in the invention example and the comparative example.
(Invention example)
The homogenization heat treatment was performed at 900 to 1000 ° C. for 0.5 to 8 hours, followed by hot rolling, further cold rolling 90 to 99.95%, and aging heat treatment 450 ° C. for 2 hours. Then, after the final cold rolling is performed within a range where the total rolling rate does not become 99.95% or more, 0-30% with respect to the immediately preceding plate pressure, the strain relief annealing is performed at 300 ° C. for about 30 minutes to obtain the final characteristics. evaluated. The invention example was made so that each condition from the homogenization heat treatment to the cold rolling before the aging treatment was within the specified range. In addition, as an example of the invention in which the aging process was devised to have a higher balance between strength and pressability, an example in which aging treatment was performed at 350 ° C. for 10 hours was added.
A second phase such as a Cr compound, Cr alone, CrZr, or CrTi was generated by the above treatment.
(Comparative example)
After homogenizing heat treatment at 800 to 1080 ° C. for 0.1 to 15 hours, hot rolling is performed, cold rolling is further applied to 50 to 99.99%, aging heat treatment is applied at 450 ° C. for 2 hours, and then cooling is performed. After 30% hot rolling, strain relief annealing was performed at 300 ° C. for about 30 minutes to evaluate the final characteristics. A comparative example was made such that one or more of the conditions from homogenization heat treatment to cold rolling before aging treatment were outside the specified range.

  After each heat treatment and rolling, acid cleaning and surface polishing were performed according to the state of oxidation and roughness of the material surface, and correction with a tension leveler was performed according to the shape.

  The following property investigation was conducted on this specimen. Here, the thickness of the test material was 0.1 to 1.0 mmt unless otherwise noted.

a. Compound measurement and aspect ratio measurement:
The number of second phases precipitated and crystallized in the parent phase was observed with an electron microscope to confirm the number. For compound A of 0.01 μm or more and less than 0.1 μm, the precipitate density is determined and the sample immediately after the aging heat treatment with the least amount of strain is subjected to electrolytic polishing with a methanol solution of 20% nitric acid to obtain a sample for observation. Observation and measurement were performed with a TEM at a magnification of × 10000 to × 100,000. About 0.1 to 5 μm of compound B, the product was subjected to wet polishing and buff polishing on the cross section perpendicular to the rolling direction, and then polished for several seconds with a mixture of chromic acid: water = 1: 1. After corroding the surface, observation and measurement were performed at a magnification of × 500 to × 5000. In both cases, the total number of compounds of about 100 to 200 was divided by the observed total area and further converted to a density per mm ² .
Regarding the aspect ratio, in the second phase observed in the previous SEM, the major axis with the largest diameter and the minor axis with the smallest diameter passing through the center of gravity of the particle were measured, and the major axis / minor axis of each particle was measured. Then, the average value was obtained.

  In the following, characteristics of tensile strength, conductivity, and stress relaxation resistance were evaluated.

b. Tensile strength [TS]:
Three test pieces of JIS Z2201-13B cut out from the rolling parallel direction were measured according to JIS Z2241, and the average value was shown.

c. Conductivity [EC]:
The specific resistance was measured by a four-terminal method in a constant temperature bath maintained at 20 ° C. (± 0.5 ° C.) to calculate the conductivity. In addition, the distance between terminals was 100 mm.

d. Stress relaxation rate [SR]:
According to the Japan Copper and Brass Association JCA / B T309: 2004 “Stress Relaxation Test Method by Bending Copper and Copper Alloy Sheet Strips”, the measurement was carried out at 150 ° C. for 1000 hours as shown below. An initial stress of 80% of the proof stress was applied by the cantilever method (using a cantilever block type jig).

e. Die wear during press (pressability):
When the fracture surface is observed every 10 000 times of press, and a sag or burr of 10 μm or more appears, the wear of the mold progresses, the shape cannot be maintained to satisfy product reliability, and the mold needs to be replaced It was said that. Sampling was performed every 1 million times, and the effective number of presses was determined by measuring burrs and sagging in the cross section. After the sample cross-section is wet-polished and buffed, it is evaluated by observation with an optical microscope. If it occurs after pressing 10 million times or more, the wear resistance is good, and if it is 9 million times or less, it is bad. I saw it. In addition, each sample thickness was unified with 0.3 mmt, and the sample preparation was performed so that the thickness of the cast book mold was changed, or the ingot of the ingot was chamfered, so that the test plate thickness did not change.

  When TS> 500MPa, EC> 75% IACS, SR <25%, and pressability satisfies the above-mentioned good conditions, the terminal characteristics are excellent in heat resistance, spring characteristics, and conductivity, and cost performance for the mold Excellent copper alloy material.

  Table 1-1 shows invention examples (alloys Nos. 1 to 21) having components within the range, and Table 1-2 shows comparative examples (alloys Nos. 22 to 47) having components outside the range.

  Table 2-1 shows the results of trial manufacture in an example in which the components are within the range, Table 2-2 is the components outside the range, and the manufacturing conditions are within the scope of the invention. If the components and manufacturing conditions are within the range, all necessary characteristics and pressability are satisfied. If the components are out of the range, the strength, conductivity, stress relaxation resistance, press, even if the manufacturing conditions are within the range. One or more of the properties is not met or is difficult to manufacture.

  Table 3-1 shows the results of trial manufacture in an example where the components are within the range, Table 3-2 is the components outside the range, and the manufacturing conditions are outside the scope of the invention. Regardless of whether the component is within the range or not, if the manufacturing condition is out of the range, the characteristics are not satisfied or it is difficult to manufacture. In particular, when the heat treatment is performed at a temperature lower or shorter than the range under the homogenized heat treatment conditions, the strength and stress relaxation resistance are inferior, and when the heat treatment is performed at a higher temperature or longer than the range, the pressability is inferior. No. 2-10 to 18, 20, 21, 38 to 43, 47 are examples in which the homogenization heat treatment conditions are performed at a temperature higher than the range. No. processed in the same temperature range. The reason why 1-8 is an example of the invention, but these are comparative examples having inferior characteristics is that the amount of Cr added is greatly different. That is, it depends on whether or not the second phase corresponding to B remains in an amount within the range in the high temperature heat treatment.

  Table 4 shows alloy Nos. Whose component ratios are within the scope of the invention. 3, 9, and 15 show the results of trial manufacture by further changing the heat treatment conditions or changing the rolling process conditions that are constant in Tables 2 to 3. Even if the conditions are different, all the characteristics are satisfied if they are within the range, and if they are out of the range, one or more of the strength, conductivity, stress relaxation resistance, and press properties are not satisfied, or manufacturing is difficult. It has become. No. Nos. 3-35 and 36 are cases in which the aging conditions are changed to a low temperature and a long time, which are invention examples in which the balance between strength and pressability is improved.

  As described above, the alloy material of the present invention is suitable for in-vehicle components centering on EVs and HEVs, as well as lead frames, connectors, terminal materials, etc. for peripheral infrastructures and solar power generation systems.

Claims (3)

Containing 0.1 to 1.2 mass% of Cr, 0.15 mass% or less of Mg, 0.06 mass% or less of Ti, 0.10 mass% or less of Zr, 0.20 mass% or less of Zn, and 0.08 mass of Fe % Or less, Sn is 0.25 mass% or less, Ag is 0.10 mass% or less, and Si is contained in a total of 0.005 to 0.5 mass%, with the balance being copper. Consisting of inevitable impurities,
From the electron image or transmission image of the electron microscope, the aspect ratio which is the ratio of the major axis / minor axis of each particle is calculated by measuring the major axis with the largest diameter and the minor axis with the smallest diameter passing through the center of gravity of the particle. When the average value of the major axis and the minor axis is the diameter size, the second phase having a diameter size of 0.01 μm or more and less than 0.1 μm is designated as the second phase A, and the second phase having a diameter size of 0.1 to 5 μm. Is the second phase B, the density of the second phase A exceeds 1 × 10 ⁶ pieces / mm ^2, and the density of the second phase B exceeds 1 × 10 ³ pieces / mm ² ,
A copper alloy material characterized by a tensile strength exceeding 500 MPa, an electrical conductivity exceeding 75% IACS, and a stress relaxation rate being less than 25%.   The copper alloy material according to claim 1, wherein an average value obtained by dividing the major axis by the minor axis is 10 to 50 with respect to the aspect ratio of the second phase B. It is a manufacturing method of the copper alloy material according to claim 1 or 2,
To the copper alloy raw material having an alloy composition to give the copper alloy material, casting [step 1], homogenization heat treatment step [step 2], hot working step [step 3], after cold working, heat treatment and cold as necessary In performing the processing step [Step 4] that repeats processing, the aging heat treatment step [Step 5], the final cold rolling step [Step 6], and the strain relief annealing step [Step 7]
The homogenization heat treatment [Step 2] is performed at 900 to 1000 ° C. for 0.5 to 8 hours,
A method for producing a copper alloy material in which the total rolling rate after casting [Step 1] is 90 to 99.95% and the processing rate in the final cold rolling step [Step 6] is 0 to 30%.