KR20150047624A - Copper alloy plate exhibiting excellent conductivity and stress-relaxation properties - Google Patents

Abstract

A copper alloy plate having high strength, high electrical conductivity and excellent stress relaxation characteristics, electronic components for large current using the copper alloy plate, electronic components for heat dissipation, and a method for manufacturing a copper alloy plate. Zr and Ti in an amount of 0.01 to 0.50 mass% in total, the balance of copper and its inevitable impurities, and having an electrical conductivity of 70% IACS or more and a 0.2% proof stress of 330 MPa or more, At least one of Ag, Fe, Co, Ni, Cr, Mn, Zn, Mg, Si, P, Sn and B in an amount of 1.0 mass% or less Containing copper alloy.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a copper alloy plate having excellent conductivity and stress relaxation properties,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper alloy plate and an electronic component for exclusive use or heat dissipation and more particularly to an electronic component such as a terminal, a connector, a relay, a switch, a socket, a bus bar, a lead frame, A copper alloy plate used as a material of the copper alloy plate, and an electronic part using the copper alloy plate. Among them, a copper alloy plate and a copper alloy plate which are suitable for the use of electronic components for large current such as connectors and terminals for large currents used in electric vehicles and hybrid cars, and for applications of heat dissipation electronic components such as liquid crystal frames used in smart phones and tablet PCs And an electronic component using the copper alloy plate.

Parts such as terminals, connectors, switches, sockets, relays, bus bars, lead frames, heat sinks, and the like for transmitting electricity or heat are mounted on automobiles, electric and electronic devices, etc., and copper alloy plates are used for these parts. Here, the electrical conductivity and the thermal conductivity are in a proportional relationship.

In recent years, with the miniaturization of electronic components, the cross-sectional area of the copper alloy plate in the current-passing portion tends to be reduced. As the cross-sectional area becomes smaller, the heat from the copper alloy plate when energized increases. In addition, there is a part where a remarkably high current flows in an electronic part used in an electric vehicle or a hybrid electric vehicle in which growth is remarkable, such as a connector of a battery part, and the heat generation of the copper alloy plate in a problem is a problem. When the heat generation is excessive, the copper alloy plate is exposed to a high temperature environment.

In an electrical contact of an electronic component such as a connector, a warping is given to a copper alloy plate, and a contact force at a contact is obtained by the stress generated by the warping. When the copper alloy sheet to which the warp is imparted is kept at a high temperature for a long time, the stress or the contact force is lowered by the stress relaxation phenomenon, and the contact electrical resistance is increased. To cope with this problem, the copper alloy plate is required to have better conductivity so as to reduce the calorific value, and furthermore, it is required that the stress relaxation property is further improved so as not to lower the contact force even if heat is generated.

On the other hand, for example, a heat dissipation component called a liquid crystal frame is used for a liquid crystal of a smartphone or a tablet PC. Even in such a copper alloy plate for heat radiation use, if the stress relaxation property is increased, creep deformation of the heat sink due to external force is suppressed, and the effect of improving the protection against liquid crystal parts and IC chips disposed around the heat sink can be expected have. For this reason, copper alloy plates for heat radiation use are also required to have excellent stress relaxation characteristics.

It is known that when Zr or Ti is added to Cu, the stress relaxation property is improved (see, for example, Patent Document 1). (0.1 mass% Zr-balance Cu), C15150 (0.02 mass% Zr-balance Cu), C18140 (0.1 mass% Zr-0.3), and the like, which have high electrical conductivity and relatively high strength and good stress relaxation properties. Cr-0.02 mass% Si-balance Cu), C18145 (0.1 mass% Zr-0.2 mass% Cr-0.2 mass% Zn-balance Cu), C18070 (0.1 mass% Ti-0.3 mass% Cr- 0.02 mass% Si - the balance Cu), and C18080 (0.06 mass% Ti-0.5 mass% Cr-0.1 mass% Ag-0.08 mass% Fe-0.06 mass% Si-balance Cu) are registered in CDA (Copper Development Association) .

Japanese Laid-Open Patent Publication No. 2011-117055

However, although a copper alloy (hereinafter referred to as a Cu-Zr-Ti alloy) in which Cu is added with Zr or Ti has a relatively good stress relaxation property, the level of the stress relaxation property is a component that energizes a large current or It can not be said that the use of a component that dissipates a large heat quantity is necessarily sufficient. For example, in the copper alloy plate disclosed in Patent Document 1, 0.05 to 0.3 mass% of Zr is added and one of Mg, Ti, Zn, Ga, Y, Nb, Mo, Ag, Or more and 0.01 to 0.3 mass% in terms of the average grain size and the grain size after the intermediate annealing were adjusted to 20 to 100 占 퐉. The stress relaxation rate after maintaining at 150 占 폚 for 1000 hours in the examples was the lowest Is 17.2%.

Therefore, it is an object of the present invention to provide a copper alloy plate having high strength, high conductivity and excellent stress relaxation characteristics, and more specifically, to provide a Cu-Zr-Ti alloy plate improved in stress relaxation property We will do it. Further, it is an object of the present invention to provide a method for producing the copper alloy sheet, and an electronic component suitable for use in a large current or heat radiation.

The present inventors have found that a copper alloy sheet having high strength, high conductivity and excellent stress relaxation characteristics can be obtained by containing an appropriate amount of an element for improving the stress relaxation property in a copper alloy sheet.

In one aspect, the present invention is based on the above findings. In one aspect, the present invention provides a copper alloy containing 0.01 to 0.50 mass% in total of one or both of Zr and Ti, the balance copper and inevitable impurities, Fe, Co, Ni, Cr, Mn, Zn, Mg, and Cr with a conductivity of IACS or higher and a 0.2% proof stress of 330 MPa or higher and a stress relaxation rate after maintaining at 150 ° C for 1000 hours of 15% Si, P, Sn and B in an amount of 1.0 mass% or less.

In one embodiment of the copper alloy sheet according to the present invention, the relationship between the spring limit value Kb (MPa) and the 0.2% proof stress? (MPa) is given by Kb? (? -100).

In the copper alloy plate is carried out another aspect of the present invention, the diffraction integrated intensity of the surface X-ray diffraction (111) plane and (311) obtained in the thickness direction in the rolling plane using the I ₍₁₁₁₎ and each I ₍₃₁₁₎ , I ₍₁₁₁₎ / I ₍₃₁₁₎ is 5.0 or less.

In another aspect, the present invention is an electronic component for a large current using the copper alloy plate.

According to another aspect of the present invention, there is provided a heat dissipation electronic component using the copper alloy plate.

In another aspect of the present invention, the ingot is hot-rolled at a temperature of 800 to 1000 占 폚 to a thickness of 3 to 30 mm, then cold rolling and recrystallization annealing are repeated, and after the final cold rolling, As a method for producing a copper alloy plate,

(A) In the recrystallization annealing before the final cold rolling, the furnace temperature is adjusted to 350 to 800 캜, the average crystal grain size of the copper alloy plate is adjusted to 50 탆 or less,

(B) In the final cold rolling, the total processing degree is 25 to 99%, the rolling degree per pass is 20% or less,

(C) In the deformation-removing annealing, a continuous annealing furnace is used, and the copper alloy plate is passed through at a furnace temperature of 300 to 700 占 폚 and a tensile force applied to the copper alloy plate in the furnace at 1 to 5 MPa, Lowering the internal strength by 10 to 50 MPa

Wherein the copper alloy sheet is a copper alloy sheet.

According to the present invention, it is possible to provide a copper alloy plate having high strength, high conductivity and excellent stress relaxation characteristics, a method for producing the same, and an electronic component suitable for use in a large current or heat radiation. This copper alloy can be preferably used as a material for an electronic part such as a terminal, a connector, a switch, a socket, a relay, a bus bar and a lead frame. Particularly, . ≪ / RTI >

1 is a view for explaining the principle of measurement of a stress relaxation rate.
2 is a view for explaining the principle of measurement of the stress relaxation rate.

(characteristic)

The copper alloy sheet according to the embodiment of the present invention has a conductivity of 70% IACS or more and has a 0.2% proof stress of 330 MPa or more. If the conductivity is 70% IACS or more, the heating value of the system is equivalent to that of pure copper. If the 0.2% proof stress is 330 MPa or more, it can be said that the strength is required as the material of a part for energizing a large current or the material for dissipating a large heat quantity.

Regarding the stress relaxation characteristics of the copper alloy sheet according to the embodiment of the present invention, the stress relaxation rate of the copper alloy sheet when subjected to a stress of 80% of 0.2% proof stress and maintained at 150 占 폚 for 1000 hours is 15% or less , And more preferably 10% or less. The stress relaxation rate of a conventional Cu-Zr-Ti alloy is about 25 to 35%, but when it is 15% or less, contact electric resistance accompanying increase in contact force is increased even when a large current is passed after machining into a connector And creep deformation is less likely to occur even when heat and external force are applied simultaneously after machining with a heat sink.

(Alloy component concentration)

The copper alloy sheet according to the embodiment of the present invention contains 0.01 to 0.50 mass%, more preferably 0.02 to 0.20 mass%, of one or both of Zr and Ti in total. As a result, the strength and the stress relaxation property are improved as compared with a normal Cu-Zr-Ti alloy. When the total of one or both of Zr and Ti is less than 0.01% by mass, it is difficult to obtain a 0.2% proof stress of 330 MPa or more and a stress relaxation rate of 15% or less. If the total of one or both of Zr and Ti exceeds 0.5% by mass, it becomes difficult to produce an alloy by hot rolling cracking or the like. When Zr is added, the addition amount is preferably adjusted to 0.01 to 0.45 mass%, and when Ti is added, the addition amount is preferably adjusted to 0.01 to 0.20 mass%. If the addition amount is less than the lower limit value, the effect of improving the stress relaxation property is hardly obtained. If the addition amount exceeds the upper limit value, the conductivity and the productivity may be deteriorated.

The Cu-Zr-Ti alloy may contain at least one of Ag, Fe, Co, Ni, Cr, Mn, Zn, Mg, Si, P, Sn and B in order to improve strength and heat resistance. However, if the addition amount is too large, the conductivity may be lowered to lower than 70% IACS or the alloy composition may be deteriorated. Therefore, the total amount is preferably 1.0% by mass or less, more preferably 0.5% by mass or less . Further, in order to obtain the effect of the addition, it is preferable that the added amount is 0.001 mass% or more in total amount.

(Spring limit value)

By adjusting the metal structure with the spring limit value as an indicator, the stress relaxation characteristics of the copper alloy sheet are improved. In the copper alloy sheet according to the present invention, when the spring limit value of the product is Kb (MPa) and the 0.2% proof stress is? (MPa), Kb? (? -100) (? - 50), the stress relaxation characteristics are improved. In the case of Kb < (? -100), the stress relaxation rate exceeds 15%. The upper limit value of Kb is not particularly restricted, but it is not usually a value exceeding?.

(Crystal orientation of the rolled surface)

By controlling the orientation of the crystal grains to be oriented on the rolled surface, the stress relaxation characteristics of the copper alloy sheet are further improved. In the copper alloy sheet according to the present invention, stress relaxation characteristics are improved by adjusting I ₍₁₁₁₎ / I ₍₃₁₁₎ to 5.0 or less, preferably 2.0 or less, on the rolled surface of the product. Here, I ₍₁₁₁₎ and I ₍₃₁₁₎ are the diffraction integral intensities of the (111) plane and the (311) plane obtained in the thickness direction of the copper alloy plate using the X-ray diffraction method, respectively. If I ₍₁₁₁₎ / I ₍₃₁₁₎ exceeds 5.0, the stress relaxation rate exceeds 15%. The lower limit value of I ₍₁₁₁₎ / I ₍₃₁₁₎ is not limited in terms of improving the stress relaxation property, but I ₍₁₁₁₎ / I ₍₃₁₁₎ typically takes a value of 0.01 or more.

(thickness)

The thickness of the product is preferably 0.1 to 2.0 mm. If the thickness is too thin, the cross sectional area of the conductive part becomes small and heat generation in the passage increases, which makes it unsuitable as a material for a connector or the like that flows a large current, and is deformed by a slight external force. On the other hand, if the thickness is excessively large, bending becomes difficult. From this viewpoint, the more preferable thickness is 0.2 to 1.5 mm. When the thickness is within the above range, the bending workability can be improved while suppressing heat generation in communication.

(Usage)

The copper alloy sheet according to the embodiment of the present invention can be suitably used for the use of electronic parts such as terminals, connectors, relays, switches, sockets, bus bars, lead frames and heat sinks. Particularly in the case of electric vehicles, The present invention is useful for the use of large-current electronic components such as large-current connectors and terminals to be used or for use of heat-dissipating electronic components such as liquid crystal frames used in smart phones and tablet PCs.

(Manufacturing method)

It is possible to reduce the oxygen concentration by carbon deoxidation or the like and then add one or two kinds of Zr and Ti and other alloying elements as necessary to dissolve the copper or the like as a pure copper raw material, Cast with ingot. This ingot is formed into a plate having a thickness of about 3 to 30 mm by, for example, hot rolling at 800 to 1000 DEG C, and then cold rolling and recrystallization annealing are repeated, and the final ingot is finished to a predetermined thickness by cold rolling, Deformation removal annealing is performed. The spring limit value after the final cold rolling is low enough not to exceed 100 MPa, but it rises by the subsequent deformation-removing annealing.

In the recrystallization annealing, part or all of the rolled structure is recrystallized. Further, by annealing under suitable conditions, Zr, Ti, and the like are precipitated, and the conductivity of the alloy increases. In the recrystallization annealing before the final cold rolling, the average crystal grain size of the copper alloy sheet is adjusted to 50 占 퐉 or less. If the average crystal grain size is too large, it becomes difficult to adjust the 0.2% proof stress of the product to 330 MPa or more.

The conditions of the recrystallization annealing before the final cold rolling are determined based on the targeted grain size after annealing and the conductivity of the target product. Specifically, annealing may be carried out by using a batch furnace or a continuous annealing furnace at a furnace temperature of 350 to 800 占 폚. In the batch furnace, the heating time may be appropriately adjusted within a range of 30 minutes to 30 hours at an in-furnace temperature of 350 to 600 ° C. In the continuous annealing furnace, the heating time may be appropriately adjusted within the range of 5 seconds to 10 minutes at the furnace temperature of 450 to 800 ° C. Generally, when annealing is performed at a lower temperature for a longer time, a higher conductivity is obtained with the same crystal grain size.

In the final cold rolling, the material is repeatedly passed between the pair of rolling rolls to finish with the target plate thickness. And controls the total machining and final machining per pass of the final cold rolling.

The total machinability R (%) is given by R = (t ₀ - t) / t ₀ x 100 (t ₀ : plate thickness before final cold rolling, t: plate thickness after final cold rolling). R = (T ₀ - T) / T ₀ × 100 (T ₀ : Thickness before passing the rolling roll, T: thickness after passing through the rolling roll).

The total processing degree R is preferably 25 to 99%. If R is too small, it becomes difficult to adjust the 0.2% proof stress to 330 MPa or more. If R is excessively large, the edge of the rolled material may be cracked.

It is preferable that the processing ratio r per one pass is 20% or less. If r is too large, it is difficult to adjust I ₍₁₁₁₎ / I ₍₃₁₁₎ to 5.0 or less if I ₍₁₁₁₎ / I ₍₃₁₁₎ increases and any path with r exceeding 20% Loses.

The deformation-removing annealing of the present invention is carried out using a continuous annealing furnace. In the case of the arrangement, since the material is heated in the state of being wound in a coil, the material deforms during heating to cause warping of the material. Thus, the batch is unsuitable for the strain relief annealing of the present invention.

In the continuous annealing furnace, the furnace temperature was set to 300 to 700 ° C, the heating time was appropriately adjusted in the range of 5 seconds to 10 minutes, and the 0.2% proof stress (σ) after deformation removal annealing was set to 0.2% σ ₀ ) of 10 to 50 MPa, preferably 15 to 45 MPa. As a result, the low Kb in the final cold rolling finish is sufficiently raised. (σ ₀ - σ) is too small or too large, it is difficult to obtain a relationship of Kb ≥ (σ -100) without sufficiently increasing Kb.

In the deformation removing annealing, the tension applied to the material in the continuous annealing furnace is adjusted to 1 to 5 MPa, more preferably 1 to 4 MPa. If the tension is excessively large, it becomes difficult to adjust I ₍₁₁₁₎ / I ₍₃₁₁₎ to 5.0 or less. Also, the rise of Kb tends to be insufficient. On the other hand, if the tensile force is too small, the material passing through the annealing furnace may come into contact with the furnace wall, resulting in scratches on the surface or edge of the material.

According to the copper alloy sheet according to the present invention, by imparting to the Cu-Zr-Ti alloy a characteristic of Kb ≥ (σ -100) and I ₍₁₁₁₎ / I ₍₃₁₁₎ ≤ 5.0, the stress relaxation property is improved However, if the manufacturing conditions for the conditions are summarized,

(1) For Kb ≥ σ - 100,

a. In the strain relief annealing, (σ ₀ - σ) = 10 to 50 MPa,

b. The furnace tension in the deformation-removing annealing is adjusted to 5 MPa or less,

(2) For I ₍₁₁₁₎ / I ₍₃₁₁₎ ? 5.0,

a. In the final cold rolling, the degree of processing per pass is adjusted to 20% or less,

b. The in-furnace tension in the deformation removing annealing is adjusted to 5 MPa or less

.

Example

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

The alloy element was added to molten copper and then cast into an ingot having a thickness of 200 mm. The ingot was heated at 950 占 폚 for 3 hours and hot rolled to form a plate having a thickness of 15 mm. The oxide scale on the surface of the hot-rolled plate was grinded and removed by a grinder, and then annealing and cold rolling were repeated, and the final cold-rolled was finished to a predetermined product thickness. Finally, strain relief annealing was performed using a continuous annealing furnace.

Annealing (final recrystallization annealing) before the final cold rolling was performed in a batch furnace and the furnace temperature was adjusted to a range of 350 to 700 캜 with a heating time of 5 hours to change the crystal grain size and the conductivity after annealing. In the measurement of the crystal grain size after annealing, the cross section perpendicular to the rolling direction was chemically corroded after the mirror polishing, and the average crystal grain size was determined according to the cutting method (JIS H 0501 (1999)).

In the final cold rolling, the total degree of processing and the degree of processing per pass were controlled. Further, the 0.2% proof stress of the material after the final cold rolling was obtained. In the deformation removing annealing using the continuous annealing furnace, the furnace temperature was set to 500 캜, the heating time was adjusted within a range of 1 second to 15 minutes, and the 0.2% proof stress after annealing was varied in various ways. Further, the tensile force added to the material in the furnace was varied in various ways. In some examples, deformation removal annealing was not performed.

The following measurements were made on the material during manufacture and the material after deformation-removal annealing.

(ingredient)

Alloying element concentration of the material after deformation removal annealing was analyzed by ICP-mass spectrometry.

(0.2% proof)

For the material after the final cold rolling and after the deformation removing annealing, the test piece No. 13B specified in JIS Z 2241 is taken in such a manner that the tensile direction becomes parallel to the rolling direction, and a tensile test is performed in parallel with the rolling direction in accordance with JIS Z 2241 , And a 0.2% proof stress was obtained.

(Spring limit value)

A specimen having a width of 10 mm and a length of 100 mm was sampled from the material after deformation removal annealing such that the longitudinal direction of the specimen was parallel to the rolling direction and subjected to a moment-type test prescribed in JIS H 3130 A spring limit value in a parallel direction was measured.

(Conductivity)

From the material after deformation-removing annealing, a test piece was taken so that the longitudinal direction of the test piece became parallel to the rolling direction, and the conductivity at 20 캜 was measured by the four-terminal method according to JIS H 0505.

(Crystal orientation)

X-ray diffraction intensities of the (111) plane and the (311) plane in the thickness direction were measured with respect to the surface of the material after deformation-removing annealing. As the X-ray diffraction apparatus, RINT2500 manufactured by RIGAKU CO., LTD. Was used and measurements were made with Cu tube (bulb) at a tube voltage of 25 kV and a tube current of 20 mA.

(Stress relaxation rate)

A test piece having a width of 10 mm and a length of 100 mm was sampled from the material after deformation removal annealing such that the longitudinal direction of the test piece was parallel to the rolling direction. 1, a stress (s) corresponding to 80% of the 0.2% proof stress (measured in accordance with JIS Z 2241) was given to the specimen with warpage of y ₀ with a position of 1 = 50 mm as a point of action. . y ₀ was obtained from the following equation.

y ₀ = (2/3) · l ² · s / (E · t)

Where E is the Young's modulus in the rolling direction and t is the thickness of the sample. At 150 ℃ after 1,000 hours heating unloading (除荷) and also the permanent deformation amount (height) measurements to y, and the stress relaxation ratio {[y (㎜) / y 0 (㎜)] × 100 (%)} as in the second Respectively.

Table 1 shows the evaluation results. Although a plurality of passes were performed in the final cold rolling, the maximum value among the degrees of processing of each of these passes was shown. The notation "<10 μm" in the crystal grain size after the final recrystallization annealing in Table 1 indicates that when all of the rolled structure was recrystallized so that the average crystal grain size was less than 10 μm and when only a part of the rolled structure was recrystallized As shown in FIG.

In the copper alloy sheets of Inventive Examples 1 to 25, the total concentration of Zr and Ti was adjusted to 0.01 to 0.50 mass%, the crystal grain size was adjusted to 50 占 퐉 or less in the recrystallization annealing before the final cold rolling, , The total process degree was adjusted to 25 to 99% and the process degree per one pass was adjusted to 20% or less. In the deformation removing annealing, the material was passed through a continuous annealing furnace at a tension of 1 to 5 MPa to obtain a 0.2% To 50 MPa.

In the copper alloy sheets of Inventive Examples 1 to 25, the additive amounts of Zr and Ti are all appropriate, and an electrical conductivity of 70% IACS or more, a 0.2% proof stress of 330 MPa or more, and a stress relaxation ratio of 15% or less can be achieved. In the copper alloy sheets of Inventive Examples 1 to 25, it can be seen that the relation of Kb? (? -100) and the relationship of I ₍₁₁₁₎ / I ₍₃₁₁₎ ? 5.0 are obtained.

In Comparative Example 1, deformation removal annealing was not performed, and the stress relaxation rate exceeded 30%.

In Comparative Examples 3 and 4 in which I ₍₁₁₁₎ / I ₍₃₁₁₎ exceeded 5.0, in particular, the tensile strength was high because the material tension in the furnace exceeded 5 MPa (? - Kb) exceeded 100. The stress relaxation ratios of Comparative Examples 2 to 4 exceeded 15%.

In Comparative Examples 5 and 6, since the degree of processing per one pass in the final cold rolling exceeds 20%, I ₍₁₁₁₎ / I ₍₃₁₁₎ exceeds 5.0 and the stress relaxation rate exceeds 15% .

In Comparative Examples 7 and 8, the degradation amount of the 0.2% proof stress in the deformation removal annealing was too small, and in the Comparative Examples 9 and 10, the degradation amount of the 0.2% proof stress in the deformation removal annealing was excessive. For this reason, (σ ₀ - σ) in Comparative Examples 7 to 10 deviated from the range of 10 to 50 MPa. As a result, (? - Kb) exceeded 100 and the stress relaxation rate exceeded 15%.

In Comparative Example 11, since the total processed degree in the final cold rolling was not less than 25%, and in Comparative Example 12, the crystal grain size of the recrystallization annealing finish before final cold rolling exceeded 50 占 퐉. Therefore, The proof stress was not less than 330 MPa.

In Comparative Example 13, since the total concentration of Zr and Ti was less than 0.01% by mass, the 0.2% proof stress after deformation removal annealing was less than 330 MPa and the stress relaxation rate exceeded 15%.

Claims (7)

Zr and Ti in an amount of 0.01 to 0.50 mass% in total, the balance of copper and its inevitable impurities, and having an electrical conductivity of 70% IACS or more and a 0.2% proof stress of 330 MPa or more, , The stress relaxation rate after holding for 1000 hours is 15% or less,
Wherein at least one of Ag, Fe, Co, Ni, Cr, Mn, Zn, Mg, Si, P, Sn and B is contained in an amount of 1.0 mass% or less. The method according to claim 1,
Wherein a relationship between a spring limit value Kb (MPa) and a 0.2% proof stress? (MPa) is given by Kb? (? -100). The method according to claim 1,
When the diffraction integrated intensity of the (111) by using X-ray diffraction obtained in the thickness direction in the rolling plane surface and the (311) plane as I ₁₁₁ and I _311, respectively, I ₍₁₁₁₎ / I _{( 311)} is 5.0 or less. 3. The method of claim 2,
When the diffraction integrated intensity of the (111) by using X-ray diffraction obtained in the thickness direction in the rolling plane surface and the (311) plane as I ₁₁₁ and I _311, respectively, I ₍₁₁₁₎ / I _{( 311)} is 5.0 or less. An electronic component for a large current using the copper alloy plate according to any one of claims 1 to 4. A heat dissipation electronic component using the copper alloy sheet according to any one of claims 1 to 4. There is provided a method for producing a copper alloy plate in which an ingot is hot-rolled at a temperature of 800 to 1000 占 폚 to a thickness of 3 to 30 mm and then subjected to cold rolling and recrystallization annealing,
(A) In the final recrystallization annealing before cold rolling, the furnace temperature is adjusted to 350 to 800 캜, the average crystal grain size of the copper alloy plate is adjusted to 50 탆 or less,
(B) In the final cold rolling, the total working degree is 25 to 99%, the rolling degree per one pass is 20% or less,
(C) In the above deformation-removing annealing, a continuous annealing furnace is used, and the copper alloy plate is passed through the furnace at a furnace temperature of 300 to 700 占 폚 and a tensile force applied to the copper alloy plate in the furnace of 1 to 5 MPa, The method for producing a copper alloy plate according to any one of claims 1 to 4, which further comprises lowering the yield strength by 10 to 50 MPa.

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