JP5470483B1 - Copper alloy sheet with excellent conductivity and stress relaxation properties - Google Patents

Abstract

A copper alloy plate having high strength, high conductivity, and excellent stress relaxation characteristics, a high-current electronic component and a heat dissipation electronic component using the copper alloy plate, and a method for producing the copper alloy plate are provided.
One or two of Zr and Ti are contained in a total amount of 0.01 to 0.50% by mass, the balance is made of copper and its inevitable impurities, the conductivity is 70% IACS or higher, and 330 MPa. A copper alloy sheet having the above 0.2% proof stress and having a stress relaxation rate of 15% or less after holding at 150 ° C. for 1000 hours.
[Selection figure] None

Description

  TECHNICAL FIELD The present invention relates to a copper alloy plate and electronic parts for energization or heat dissipation, and in particular, electronic parts such as terminals, connectors, relays, switches, sockets, bus bars, lead frames, heat sinks, etc. mounted on electric machines / electronic devices, automobiles, etc. The present invention relates to a copper alloy plate used as a material for the above and an electronic component using the copper alloy plate. Among them, copper alloys suitable for use in high current electronic parts such as connectors and terminals for large currents used in electric cars, hybrid cars, etc., or for use in electronic parts for heat dissipation such as liquid crystal frames used in smartphones and tablet PCs The present invention relates to a plate and an electronic component using the copper alloy plate.

  Parts such as terminals, connectors, switches, sockets, relays, bus bars, lead frames, heat sinks, etc., that transmit electricity or heat are built into automobiles, electrical equipment, electronic devices, etc., and these parts are made of copper alloy. It is used. Here, electrical conductivity and thermal conductivity are in a proportional relationship.

  In recent years, with the miniaturization of electronic components, the cross-sectional area of the copper alloy in the current-carrying part tends to be small. When the cross-sectional area becomes small, heat generation from the copper alloy when energized increases. In addition, electronic parts used in fast-growing electric vehicles and hybrid electric vehicles include parts through which a remarkably high current flows, such as a connector of a battery unit, and heat generation of a copper alloy during energization is a problem. When the heat generation becomes excessive, the copper alloy is exposed to a high temperature environment.

  In an electrical contact of an electronic component such as a connector, a deflection is given to the copper alloy plate, and a contact force at the contact is obtained by a stress generated by the deflection. When a bent copper alloy is held at a high temperature for a long time, the stress, that is, the contact force is reduced due to the stress relaxation phenomenon, and the contact electric resistance is increased. In order to cope with this problem, the copper alloy is required to be more excellent in conductivity so that the amount of heat generation is reduced, and is also required to be superior in stress relaxation characteristics so that the contact force does not decrease even if heat is generated.

  On the other hand, for example, a heat radiating 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 dissipation, when stress relaxation characteristics are enhanced, creep deformation of the heat sink due to external force is suppressed, and the protection against liquid crystal components, IC chips, etc. disposed around the heat sink is improved. Etc. can be expected. For this reason, it is desired that the copper alloy plate for heat dissipation also has excellent stress relaxation characteristics.

  It is known that when Zr or Ti is added to Cu, the stress relaxation characteristics are improved (see, for example, Patent Document 1). Examples of materials having high electrical conductivity and relatively high strength and good stress relaxation characteristics include C15100 (0.1 mass% Zr-residual Cu), C15150 (0.02 mass% Zr-residual Cu), C18140 (0 .1 mass% Zr-0.3 mass% Cr-0.02 mass% Si-residual Cu), C18145 (0.1 mass% Zr-0.2 mass% Cr-0.2 mass% Zn-residual Cu) C18070 (0.1 mass% Ti-0.3 mass% Cr-0.02 mass% Si-residual Cu), C18080 (0.06 mass% Ti-0.5 mass% Cr-0.1 mass% Ag) Alloys such as -0.08 mass% Fe-0.06 mass% Si-residual Cu) are registered in CDA (Copper Development Association).

JP 2011-1117055 A

  However, although a copper alloy obtained by adding Zr or Ti to Cu (hereinafter referred to as a Cu-Zr-Ti alloy) has relatively good stress relaxation characteristics, the level of the stress relaxation characteristics is a large current. It is not always sufficient as a use of a component that supplies electricity or a component that dissipates a large amount of heat. For example, in the copper alloy plate disclosed in Patent Document 1, 0.05 to 0.3% by mass of Zr is added, and Mg, Ti, Zn, Ga, Y, Nb, Mo, Ag, In, and Sn are included. The stress relaxation characteristics are improved by adding one or more of 0.01 to 0.3% by mass and adjusting the crystal grain size after intermediate annealing to 20 to 100 μm. The stress relaxation rate after holding for 1000 hours is at least 17.2%.

  Therefore, an object of the present invention is to provide a copper alloy plate having high strength, high conductivity, and excellent stress relaxation characteristics, and specifically, a Cu-Zr-Ti system having improved stress relaxation characteristics. It is an object to provide an alloy. Furthermore, another object of the present invention is to provide a method for producing the copper alloy and an electronic component suitable for high current use or heat dissipation use.

  As a result of intensive studies to solve the above problems, the present inventor combines high strength, high electrical conductivity, and excellent stress relaxation characteristics by including an appropriate amount of an element that improves stress relaxation characteristics in the copper alloy sheet. It has been found that a copper alloy sheet can be obtained.

The present invention completed on the basis of the above knowledge, in one aspect, contains 0.02 to 0.50% by mass of Zr, the balance is made of copper and its inevitable impurities, has a conductivity of 70% IACS or higher, and 330 MPa. The above-mentioned 0.2% yield strength, the relationship between the spring limit value Kb (MPa) and the 0.2% yield strength σ (MPa) is given by Kb ≧ (σ−50). When the integrated diffraction intensities of the (111) plane and (311) plane obtained in the thickness direction on the rolling surface used are I ₍₁₁₁₎ and I ₍₃₁₁₎ , respectively , I ₍₁₁₁₎ / I ₍₃₁₁₎ is 2. A copper alloy sheet having a stress relaxation rate of 10% or less after being held at 150 ° C. for 1000 hours.

In yet another embodiment, the copper alloy plate according to the present invention is 0.001 in total of at least one of Ag, Fe, Co, Ni, Cr, Mn, Zn, Mg, Si, P, Sn, and B. having free to 1.0 mass%.

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

  In another aspect of the present invention, there is provided a heat dissipating 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 ° C. to a thickness of 3 to 30 mm, and then cold rolling and recrystallization annealing are repeated. A method for producing a copper alloy sheet for annealing,
(A) In the recrystallization annealing before the final cold rolling, the furnace temperature is set to 350 to 800 ° C., the average crystal grain size of the copper alloy plate is adjusted to 50 μm or less,
(B) In the final cold rolling, the total workability is 25 to 99%, the rolling workability per pass is 20% or less,
(C) In strain relief annealing, a continuous annealing furnace is used, the furnace temperature is 300 to 700 ° C., the tension applied to the copper alloy sheet in the furnace is 1 to 4 MPa, and the copper alloy sheet is passed through, 0 .2% proof stress is reduced by 15 to 45 MPa,
It is a manufacturing method of the said copper alloy plate including this.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the copper alloy board which has high intensity | strength, high electroconductivity, and the outstanding stress relaxation characteristic, its manufacturing method, and an electronic component suitable for a large current use or a heat dissipation use. This copper alloy can be suitably used as a material for electronic parts such as terminals, connectors, switches, sockets, relays, bus bars, lead frames, etc., and particularly dissipates the material or the large amount of heat of electronic parts that carry a large current. Useful as a material for electronic components.

It is a figure explaining the measurement principle of a stress relaxation rate. It is a figure explaining the measurement principle of a stress relaxation rate.

(Characteristic)
The copper alloy plate according to the embodiment of the present invention has a conductivity of 70% IACS or more and a 0.2% proof stress of 330 MPa or more. If the electrical conductivity is 70% IACS or higher, it can be said that the amount of heat generated during energization is equivalent to that of pure copper. In addition, if the 0.2% proof stress is 330 MPa or more, it can be said that the material has a strength necessary for a material for a component that conducts a large current or a material for a component that dissipates a large amount of heat.

  Regarding the stress relaxation characteristics of the copper alloy plate according to the embodiment of the present invention, the stress relaxation rate of the copper alloy plate when the stress of 80% of 0.2% proof stress is applied and held at 150 ° C. for 1000 hours is 15 % Or less, more preferably 10% or less. The stress relaxation rate of a normal Cu—Zr—Ti alloy is about 25 to 35%, but by reducing this to 15% or less, even if a large current is applied after processing into a connector, the contact force decreases. Increase in contact electrical resistance is unlikely to occur, and creep deformation is unlikely to occur even if heat and external force are applied simultaneously after processing into a heat sink.

(Alloy component concentration)
The copper alloy plate according to the embodiment of the present invention contains one or two of Zr and Ti in a total amount of 0.01 to 0.50% by mass, more preferably 0.02 to 0.20% by mass. . Thereby, compared with a normal Cu-Zr-Ti-based alloy, strength and stress relaxation characteristics are improved. When the total of one or two of Zr and Ti is less than 0.01% by mass, it becomes 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 two of Zr and Ti exceeds 0.5% by mass, it becomes difficult to produce an alloy due to hot rolling cracks or the like. When adding Zr, it is preferable to adjust the addition amount to 0.01 to 0.45 mass%, and when adding Ti, the addition amount is adjusted to 0.01 to 0.20 mass%. It is preferable. When the addition amount is less than the lower limit value, it is difficult to obtain the effect of improving the stress relaxation characteristics, and when the addition amount exceeds the upper limit value, conductivity and manufacturability may be deteriorated.

  Cu-Zr-Ti alloy contains 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. Can be made. However, if the amount added is too large, the electrical conductivity may be reduced to be less than 70% IACS, or the manufacturability of the alloy may be deteriorated. Therefore, the amount added is preferably 1.0% by mass or less in total. Is 0.5 mass% or less. Moreover, in order to acquire the effect by addition, it is preferable to make addition amount 0.001 mass% or more in total amount.

(Spring limit value)
By adjusting the metal structure using the spring limit value as an index, the stress relaxation characteristics of the copper alloy plate are improved. In the copper alloy plate according to the present invention, when the spring limit value of the product is Kb (MPa) and the 0.2% proof stress is σ (MPa), the relationship of Kb ≧ (σ−100) is more preferable. , Kb ≧ (σ−50), the stress relaxation characteristics are improved. In the case of Kb <(σ-100), the stress relaxation rate exceeds 15%. The upper limit value of Kb is not particularly restricted, but usually does not exceed σ.

(Crystal orientation of rolling surface)
By controlling the orientation of crystal grains oriented on the rolling surface, the stress relaxation characteristics of the copper alloy sheet are further improved. In the copper alloy sheet according to the present invention, the stress relaxation property is 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 diffraction integrated intensities of the (111) plane and the (311) plane, respectively, obtained in the thickness direction of the copper alloy plate using the X-ray diffraction method. When I ₍₁₁₁₎ / I ₍₃₁₁₎ exceeds 5.0, the stress relaxation rate exceeds 15%. Although the lower limit of _{I (111) / I (311} ) is not limited in terms of the stress relaxation characteristics _{improved, I (111) / I (} 311) typically takes a value of more than 0.01.

(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 current-carrying part will decrease and heat generation will increase during energization, making it unsuitable as a material for connectors that carry large currents, and because it will deform with a slight external force, It is also unsuitable as a material. On the other hand, if the thickness is too thick, bending becomes difficult. From such a viewpoint, a more preferable thickness is 0.2 to 1.5 mm. When the thickness is in the above range, the bending workability can be improved while suppressing heat generation during energization.

(Use)
The copper alloy plate according to the embodiment of the present invention can be suitably used for applications of electronic components such as terminals, connectors, relays, switches, sockets, bus bars, lead frames, heat sinks, in particular, electric vehicles, It is useful for applications of high-current electronic components such as high-current connectors and terminals used in hybrid vehicles and the like, or heat-dissipation electronic components such as liquid crystal frames used in smartphones and tablet PCs.

(Production method)
After dissolving electrolytic copper or the like as a pure copper raw material and reducing the oxygen concentration by carbon deoxidation or the like, one or two of Zr and Ti, and other alloy elements are added as necessary, and the thickness is 30 to 300 mm. Cast into a moderate ingot. After this ingot is made into a plate having a thickness of about 3 to 30 mm by hot rolling at 800 to 1000 ° C., for example, cold rolling and recrystallization annealing are repeated, and finally finished to a predetermined product thickness by cold rolling. Apply strain relief annealing. The spring limit value after the final cold rolling is so low that it does not reach 100 MPa, but rises by subsequent strain relief annealing.

  In recrystallization annealing, part or all of the rolling structure is recrystallized. Further, by annealing under appropriate conditions, Zr, Ti, etc. are precipitated, and the electrical conductivity of the alloy is increased. In the recrystallization annealing before the final cold rolling, the average crystal grain size of the copper alloy sheet is adjusted to 50 μm or less. If the average crystal grain size is too large, it will be difficult to adjust the 0.2% yield strength of the product to 330 MPa or more.

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

In the final cold rolling, the material is repeatedly passed between a pair of rolling rolls to finish the target plate thickness. The total workability of final cold rolling and the workability per pass are controlled.
The total workability R (%) is given by R = (t ₀ −t) / t ₀ × 100 (t ₀ : plate thickness before final cold rolling, t: plate thickness after final cold rolling). Further, the processing degree r (%) per pass is a sheet thickness reduction rate when the rolling roll passes once, and r = (T ₀ −T) / T ₀ × 100 (T ₀ : rolling roll) Thickness before passing, T: Thickness after passing 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. When R is too large, the edge of the rolled material may be broken.

The processing degree r per pass is preferably 20% or less. If r is too large increases _{I (111) / I (311} ), the path that r is more than 20% among all paths include even one I a _{(111) / I (311)} 5.0 It becomes difficult to adjust to the following.

  The strain relief annealing of the present invention is performed using a continuous annealing furnace. In the case of a batch furnace, since the material is heated in a state of being wound in a coil shape, the material is deformed during the heating, and the material is warped. Therefore, the batch furnace is not suitable for the strain relief annealing of the present invention.

In the continuous annealing furnace, the furnace temperature is set to 300 to 700 ° C., the heating time is appropriately adjusted in the range of 5 seconds to 10 minutes, and the 0.2% proof stress (σ) after the stress relief annealing is 0 before the stress relief annealing. Adjust to a value 10 to 50 MPa lower, preferably 15 to 45 MPa lower than 2% proof stress (σ ₀ ). Thereby, Kb which was low in the final cold rolling is sufficiently increased. If (σ ₀ −σ) is too small or too large, Kb does not rise sufficiently, and it becomes difficult to obtain a relationship of Kb ≧ (σ−100).

In the strain relief 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 too large, it becomes difficult to adjust I ₍₁₁₁₎ / I ₍₃₁₁₎ to 5.0 or less. Further, the increase in Kb tends to be insufficient. On the other hand, if the tension is too small, the material in the passing plate of the annealing furnace may come into contact with the furnace wall, and the surface or edge of the material may be damaged.

According to the copper alloy sheet according to the present invention, by imparting a feature of Kb ≧ (σ-100) and a feature of I ₍₁₁₁₎ / I ₍₃₁₁₎ ≦ 5.0 to the Cu—Zr—Ti alloy, One of the features is to improve the stress relaxation characteristics.
(1) For Kb ≧ σ−100,
a. In the strain relief annealing, (σ ₀ −σ) = 10 to 50 MPa,
b. Adjusting the furnace tension in the strain relief annealing 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. Adjusting the furnace tension in the strain relief annealing to 5 MPa or less,
It is preferable.

  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.

  After adding the alloy element to the molten copper, it was cast into an ingot having a thickness of 200 mm. The ingot was heated at 950 ° C. for 3 hours and formed into a plate having a thickness of 15 mm by hot rolling. After grinding and removing the oxide scale on the surface of the hot rolled plate with a grinder, annealing and cold rolling were repeated, and the product was finished to a predetermined product thickness by final cold rolling. Finally, strain relief annealing was performed using a continuous annealing furnace.

  For annealing before final cold rolling (final recrystallization annealing), a batch furnace is used, the heating time is 5 hours, the furnace temperature is adjusted in the range of 350 to 700 ° C, and the crystal grain size and conductivity after annealing are adjusted. Changed. In the measurement of the crystal grain size after annealing, a cross section perpendicular to the rolling direction was subjected to chemical corrosion after mirror polishing, and the average crystal grain size was determined by a cutting method (JIS H0501 (1999)).

  In the final cold rolling, the total workability and the workability per pass were controlled. Moreover, the 0.2% yield strength of the material after final cold rolling was calculated | required. In strain relief annealing using a continuous annealing furnace, the furnace temperature was 500 ° C., the heating time was adjusted between 1 second and 15 minutes, and the 0.2% proof stress after annealing was variously changed. In addition, various tensions were added to the material in the furnace. In some cases, strain relief annealing was not performed.

The following measurement was performed on the material in the process of manufacturing and the material after strain relief annealing.
(component)
The alloy element concentration of the material after strain relief annealing was analyzed by ICP-mass spectrometry.

(0.2% yield strength)
For the material after the final cold rolling and strain relief annealing, sample No. 13B specified in JIS Z2241 was taken so that the tensile direction was parallel to the rolling direction, and pulled in parallel with the rolling direction in accordance with JIS Z2241. Tests were performed to determine 0.2% yield strength.

(Spring limit value)
A strip-shaped test piece having a width of 10 mm and a length of 100 mm was taken from the material after strain relief annealing so that the longitudinal direction of the test piece was parallel to the rolling direction, and was subjected to a moment type test specified in JIS H3130. The spring limit value in the direction parallel to the rolling direction was measured.

(conductivity)
A test piece was taken from the material after strain relief annealing so that the longitudinal direction of the test piece was parallel to the rolling direction, and the conductivity at 20 ° C. was measured by a four-terminal method in accordance with JIS H0505.

(Crystal orientation)
The X-ray diffraction integrated intensity of the (111) plane and (311) plane was measured in the thickness direction with respect to the surface of the material after strain relief annealing. RINT 2500 manufactured by Rigaku Corporation was used as the X-ray diffractometer, and measurement was performed with a Cu tube bulb at a tube voltage of 25 kV and a tube current of 20 mA.

(Stress relaxation rate)
A strip-shaped test piece having a width of 10 mm and a length of 100 mm was collected from the material after strain relief annealing so that the longitudinal direction of the test piece was parallel to the rolling direction. As shown in FIG. 1, the stress corresponding to 80% of 0.2% proof stress (measured in accordance with JIS Z2241) in the rolling direction is applied to the test piece with the position of l = 50 mm as a working point, giving y ₀ deflection. (S) was loaded. y ₀ was determined by the following equation.
y ₀ = (2/3) · l ² · s / (E · t)
Here, E is the Young's modulus in the rolling direction, and t is the thickness of the sample. Unloading after heating at 150 ° C. for 1000 hours, and measuring the amount of permanent deformation (height) y as shown in FIG. 2, stress relaxation rate {[y (mm) / y ₀ (mm)] × 100 (%) } Was calculated.

  Table 1 shows the evaluation results. In the final cold rolling, a plurality of passes were performed, and the maximum value in the degree of processing of each pass was shown. The notation of “<10 μm” in the crystal grain size after the final recrystallization annealing in Table 1 indicates that when all of the rolling structure is recrystallized and the average crystal grain size is less than 10 μm, and only a part of the rolling structure is used. Both cases of recrystallization are included.

  In the copper alloy plates of Invention Examples 1 to 25, the total concentration of Zr and Ti is adjusted to 0.01 to 0.50 mass%, and the crystal grain size is adjusted to 50 μm or less in the recrystallization annealing before the final cold rolling. In the final cold rolling, the total workability is adjusted to 25 to 99%, the workability per pass is adjusted to 20% or less, and the material is passed through the continuous annealing furnace with a tension of 1 to 5 MPa in strain relief annealing. The 0.2% proof stress was reduced by 10 to 50 MPa.

In each of the copper alloy plates of Invention Examples 1 to 25, the addition amounts of Zr and Ti are appropriate, and an electrical conductivity of 70% IACS or higher, a 0.2% proof stress of 330 MPa or higher, and a stress relaxation rate of 15% or lower are achieved. is made of. It can also be seen that in the copper alloy plates of Invention Examples 1 to 25, the relationship of Kb ≧ (σ−100) and the relationship of I ₍₁₁₁₎ / I ₍₃₁₁₎ ≦ 5.0 are obtained.

Comparative Example 1 was not subjected to strain relief annealing, and the stress relaxation rate exceeded 30%.
In Comparative Examples 2 to 4, although strain relief annealing was performed, since the material tension in the furnace exceeded 5 MPa, I ₍₁₁₁₎ / I ₍₃₁₁₎ exceeded 5.0, and the comparatively high tension 3 (σ−Kb) also exceeded 100. The stress relaxation rate of Comparative Examples 2 to 4 exceeded 15%.
In Comparative Examples 5 and 6, since the degree of work per pass in the final cold rolling exceeded 20%, I ₍₁₁₁₎ / I ₍₃₁₁₎ exceeded 5.0 and the stress relaxation rate exceeded 15%. .
In Comparative Examples 7 and 8, the 0.2% yield strength decrease in strain relief annealing was excessively small, and in Comparative Examples 9 and 10, the 0.2% yield strength decrease in strain relief 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, (σ−Kb) exceeded 100 and the stress relaxation rate exceeded 15%.

  In Comparative Example 11, the total work degree in the final cold rolling was less than 25%, and in Comparative Example 12, the crystal grain size after recrystallization annealing before the final cold rolling exceeded 50 μm. The 0.2% proof stress was 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 strain relief annealing was less than 330 MPa, and the stress relaxation rate exceeded 15%.

Claims (5)

Zr is contained in an amount of 0.02 to 0.50% by mass, the balance is made of copper and its inevitable impurities, has a conductivity of 70% IACS or more, and a 0.2% proof stress of 330 MPa or more, and a spring limit value Kb The relationship between (MPa) and 0.2% proof stress σ (MPa) is given by Kb ≧ (σ−50), and the (111) plane obtained in the thickness direction on the rolled surface using the X-ray diffraction method and ( 311) I ₍₁₁₁₎ / I ₍₃₁₁₎ is 2.0 or less when the diffraction integral intensity of the surface is I ₍₁₁₁₎ and I ₍₃₁₁₎ , respectively , and stress relaxation after holding at 150 ° C. for 1000 hours A copper alloy sheet, wherein the rate is 10% or less. Claim for Ag, Fe, Co, Ni, Cr, Mn, Zn, Mg, Si, P, characterized in that it has free 0.001 to 1.0 wt% in total of one or more of Sn and B 1 The copper alloy plate described in 1. The electronic component for electricity supply using the copper alloy plate of Claim 1 or 2 . A heat dissipating electronic component using the copper alloy plate according to claim 1 . In the method of manufacturing a copper alloy plate, after ingot is hot rolled at 800 to 1000 ° C. to a thickness of 3 to 30 mm, cold rolling and recrystallization annealing are repeated, and after final cold rolling, strain relief annealing is performed. There,
(A) In the recrystallization annealing before the final cold rolling, the furnace temperature is set to 350 to 800 ° C., and the average crystal grain size of the copper alloy plate is adjusted to 50 μm or less,
(B) In the final cold rolling, the total workability is 25 to 99%, the rolling work per pass is 20% or less,
(C) In the strain relief annealing, using a continuous annealing furnace, the furnace temperature is 300 to 700 ° C., the tension applied to the copper alloy sheet in the furnace is 1 to 4 MPa, and the copper alloy sheet is passed through, 0.2% proof stress is reduced by 15 to 45 MPa,
The manufacturing method of the copper alloy plate of Claim 1 or 2 including this.

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