JP2017089011A - Copper alloy sheet excellent in conductivity and flexure deflection coefficient - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy sheet having high strength, high conductivity and high flexure deflection coefficient and excellent stress relaxation characteristics and an electronic component for large current and an electronic component for heat release by the copper alloy.SOLUTION: There is provided a copper alloy sheet containing one or more kind of Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Sn, Ti, Zn and Zr of total 0 to 20 mass% and the balance copper with inevitable impurities and having conductivity of 30%IACS or more and tensile strength of 300 MPa or more and total of area percentage of a crystal with an angle of a normal line of a (122) face with sheet width direction (TD) of 10 degree or less and area percentage of a crystal with an angle of a normal line of a (133) face with TD of 10 degree or less of 10% or more when an EBSD measurement is conducted on a cross section orthogonal to a TD of a rolling material.SELECTED DRAWING: 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 and the like. 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 these, copper alloys suitable for use in high current electronic parts such as high current connectors and terminals used in electric vehicles, hybrid cars, etc., or in heat dissipation electronic parts 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.

 Electrical and electronic equipment, automobiles, etc. have built-in parts for conducting electricity or heat, such as terminals, connectors, switches, sockets, relays, bus bars, lead frames, heat sinks, etc. 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, it is required to increase the bending deflection coefficient. If the connector or the like is downsized, it becomes difficult to increase the displacement of the leaf spring. For this reason, it is necessary to obtain a high contact force with a small displacement, and a higher bending deflection coefficient is required.

  Further, when the bending deflection coefficient is high, the spring back during bending becomes small, and press forming becomes easy. This advantage is particularly great in a high-current connector or the like in which a thick material is used.

 Furthermore, although the heat dissipation component called a liquid crystal frame is used for the liquid crystal of a smart phone or a tablet PC, a higher bending deflection coefficient is required even in such a copper alloy plate for heat dissipation. This is because when the bending deflection coefficient is increased, deformation of the heat sink when an external force is applied is reduced, and the protection against liquid crystal components, IC chips and the like disposed around the heat sink is improved.

 Here, the leaf spring portion of the connector or the like is usually collected in a direction in which the longitudinal direction is orthogonal to the rolling direction (the bending axis at the time of bending deformation is parallel to the rolling direction). Hereinafter, this direction is referred to as a plate width direction (TD). Therefore, an increase in the bending deflection coefficient is particularly important in TD.

  On the other hand, 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 lowered 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. Similarly, a copper alloy plate for heat dissipation is also desired to have excellent stress relaxation characteristics from the viewpoint of suppressing creep deformation of the heat dissipation plate due to external force.

  For example, in Patent Document 1, the bending deflection coefficient of TD is improved by adjusting the area ratio of a crystal whose angle formed by the normal of the (111) plane of the copper alloy plate to TD is 20 degrees or less to more than 50%. doing.

JP 2012-180593 A

  However, although conventional copper alloys have high electrical conductivity and strength, the bending deflection coefficient of TD is not at a level that is satisfactory for the use of parts that carry a large current or the parts that dissipate a large amount of heat. Further, although the conventional copper alloys have relatively good stress relaxation characteristics, the level of the stress relaxation characteristics is not always sufficient for the use of parts that carry a large current or the use of parts that dissipate a large amount of heat.

  For example, according to the Example of patent document 1, the stress relaxation characteristic of the copper alloy plate which improved the bending deflection coefficient is not necessarily favorable. Moreover, in patent document 1, in order to improve a bending deflection coefficient, the special process called 2nd type high temperature rolling is added after normal hot rolling, and this causes the remarkable increase in manufacturing cost.

  Therefore, an object of the present invention is to provide a copper alloy plate having high strength, high conductivity, a high bending deflection coefficient, and excellent stress relaxation characteristics, and an electronic component suitable for large current use or heat radiation use.

  As a result of intensive studies, the present inventor has found that the bending deflection coefficient of TD is improved by controlling the area ratio of the (122) plane and the (133) plane in the cross section orthogonal to the TD of the copper alloy plate. It was. Furthermore, in addition to this crystal orientation control, it has also been found that the stress relaxation characteristic is remarkably improved by adjusting the spring limit value of TD to an appropriate range.

  The present invention completed on the basis of the above knowledge is, in one aspect, a total of one or more of Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Sn, Ti, Zn, and Zr. A cross section perpendicular to the sheet width direction (TD) of the rolled material, containing 0 to 20% by mass, the balance being made of copper and its inevitable impurities, having a conductivity of 30% IACS or more and a tensile strength of 300 MPa or more When the EBSD measurement is performed in FIG. 5, the area ratio of the crystal whose (122) plane normal and TD form an angle of 10 degrees or less, and the (133) plane normal and TD forms an angle of 10 degrees or less. It is a copper alloy plate whose total with the area ratio of a certain crystal is 10% or more.

  In one embodiment of the copper alloy plate according to the present invention, the difference (σ−Kb) between the spring limit value (Kb) of TD and the tensile strength (σ) is adjusted to 250 MPa or less.

  In another embodiment, the copper alloy plate according to the present invention contains 0.005 to 1% by mass in total of one or more of Ag, P, Sn, Fe and Ni, and the balance is made of copper and its inevitable impurities. , 80-102% IACS conductivity.

  In another embodiment, the copper alloy plate according to the present invention is 0.1 to 0.5% by mass of Cr, 0.1 to 0.5% by mass of Sn, and 0.1 to 0.5% by mass of Zn. %, Ag, B, Co, Fe, Mg, Mn, Ni, P, Si, Ti and Zr are contained in a total of 0 to 0.2% by mass, with the balance being made of copper and its inevitable impurities And has a conductivity of 70-90% IACS.

  In another embodiment, the copper alloy plate according to the present invention is 1 to 3% by mass of Fe, 0.01 to 0.2% by mass of P, 0.05 to 0.5% by mass of Zn, Ag, B, Co, Cr, Mg, Mn, Ni, Si, Sn, Ti and Zr are contained in a total of 0 to 0.2% by mass, with the balance being copper and its inevitable impurities, It has a conductivity of 80% IACS.

  In still another embodiment, the copper alloy plate according to the present invention is 0.5 to 3% by mass of Ni, 0.2 to 2% by mass of Sn, 0.02 to 0.2% by mass of P, Ag, B, Co, Cr, Fe, Mg, Mn, Si, Ti, Zn and Zr are contained in a total of 0 to 0.2% by mass, with the balance consisting of copper and its inevitable impurities, 30 to It has a conductivity of 60% IACS.

  In yet another embodiment, the copper alloy plate according to the present invention is 0.2 to 1% by mass of Mg, 0.001 to 0.1% by mass of P, Ag, B, Co, Cr, Fe, Mn, One or more of Ni, Si, Sn, Ti, Zn and Zr are contained in a total amount of 0 to 0.2% by mass, the balance is made of copper and its inevitable impurities, and has a conductivity of 50 to 70% IACS. .

  In yet another embodiment, the copper alloy plate according to the present invention includes Zn in an amount of 1 to 15% by mass, Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Sn, Ti, and Zr. One or more of them are contained in a total amount of 0 to 0.5% by mass, the balance is made of copper and its inevitable impurities, and has a conductivity of 30 to 70% IACS.

  In yet another embodiment, the copper alloy plate according to the present invention is 0.1 to 5% by mass of Ni, 0.01 to 0.3% by mass of P, 0.01 to 0.3% by mass of Fe, Containing at least one of Ag, B, Co, Cr, Mg, Mn, Si, Sn, Ti, Zn and Zr in a total amount of 0 to 0.2% by mass, with the balance consisting of copper and its inevitable impurities, It has a conductivity of 50-90% IACS.

  In yet another embodiment of the copper alloy plate according to the present invention, the bending deflection coefficient in the plate width direction is 115 GPa or more.

  In yet another embodiment of the copper alloy plate according to the present invention, the bending deflection coefficient in the plate width direction is 115 GPa or more and the stress relaxation rate in the plate width direction after holding at 150 ° C. for 1000 hours is 50% or less.

  Another aspect of the present invention is an electronic component for large current using the copper alloy plate.

  In another aspect, the present invention is a heat dissipating electronic component using the copper alloy plate.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the copper alloy board which has high intensity | strength, high electroconductivity, a high bending deflection coefficient, and the outstanding stress relaxation characteristic, and an electronic component suitable for a large current use or a heat dissipation use. This copper alloy plate can be suitably used as a material for electronic parts such as terminals, connectors, switches, sockets, relays, bus bars, lead frames, heat sinks, etc. It is useful as a material for electronic parts that dissipate heat.

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.

The present invention will be described below.
(Target characteristics)
The copper alloy plate according to the embodiment of the present invention has a conductivity of 30% IACS or more and a tensile strength of 300 MPa or more. If the electrical conductivity is 30% IACS or higher, the amount of heat generated during energization is suppressed. Further, if the tensile strength is 300 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.

  The bending deflection coefficient of TD of the copper alloy plate according to the embodiment of the present invention is 115 GPa or more, more preferably 120 GPa or more. The spring deflection coefficient is a value calculated from the amount of deflection at the time when a load is applied to the cantilever beam within a range not exceeding the elastic limit. As an index of the elastic modulus, there is a Young's modulus obtained by a tensile test, but the spring deflection coefficient shows a better correlation with the contact force at a leaf spring contact such as a connector. By adjusting the bending deflection coefficient of the copper alloy plate to 115 GPa or more, the contact force is clearly improved after being processed into a connector or the like, and after being processed into a heat radiating plate or the like, it is clearly not easily elastically deformed against an external force. .

  Regarding the stress relaxation characteristics of the copper alloy sheet according to the embodiment of the present invention, the stress relaxation rate (hereinafter simply referred to as stress) when 80% stress of 0.2% proof stress is applied to TD and held at 150 ° C. for 1000 hours. (Denoted as relaxation rate) is 50% or less, preferably 40% or less, more preferably 30% or less, and still more preferably 20% or less. By reducing the stress relaxation rate to 50% or less, even if a large current is applied after being processed into a connector, it is difficult for the contact electrical resistance to increase due to a decrease in contact force, and heat and external force are reduced after processing into a heat sink. Even if they are added at the same time, creep deformation hardly occurs.

(Alloy components)
The effects of the present invention include one or more of Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Sn, Ti, Zn and Zr in a total amount of 0 to 20% by mass, The balance is satisfactorily exhibited in a copper alloy composed of copper and its inevitable impurities, and particularly high effects are exhibited in, for example, the following A to F copper alloys.

(Alloy A)
It is a copper alloy containing 0.005 to 1% by mass in total of one or more of Ag, P, Sn, Fe and Ni, with the balance being copper and its inevitable impurities. The conductivity of this copper alloy is 80 to 102% IACS. A more preferred component is a copper alloy containing 0.01 to 0.2% by mass in total of one or more of Ag, P, Sn, Fe and Ni, with the balance being copper and unavoidable impurities thereof. The conductivity is 83-97% IACS.

(Alloy B)
Cr is 0.1 to 0.5% by mass, Sn is 0.1 to 0.5% by mass, Zn is 0.1 to 0.5% by mass, Ag, B, Co, Fe, Mg, Mn, Ni, It is a copper alloy containing at least one of P, Si, Ti and Zr in a total of 0 to 0.2 mass%, with the balance being copper and its inevitable impurities. The conductivity of this copper alloy is 70-90% IACS. More preferable components are 0.2 to 0.4% by mass of Cr, 0.2 to 0.3% by mass of Sn, 0.2 to 0.3% by mass of Zn, Ag, B, Co, Fe, Mg , Mn, Ni, P, Si, Ti and Zr in a total of 0 to 0.2% by mass, with the balance being copper and its inevitable impurities, a copper alloy, the conductivity of this copper alloy The rate is 70-80% IACS.

(Alloy C)
Fe 1 to 3 mass%, P 0.01 to 0.2 mass%, Zn 0.05 to 0.5 mass%, Ag, B, Co, Cr, Mg, Mn, Ni, Si, Sn, It is a copper alloy containing at least one of Ti and Zr in a total amount of 0 to 0.2 mass%, with the balance being copper and its inevitable impurities. The conductivity of this copper alloy is 60-80% IACS. More preferable components are Fe to 2 to 2.5% by mass, P to 0.02 to 0.15% by mass, Zn to 0.1 to 0.2% by mass, Ag, B, Co, Cr, Mg, Mn , Ni, Si, Sn, Ti and Zr in a total of 0 to 0.2% by mass, the balance is copper alloy consisting of copper and its inevitable impurities, the conductivity of this copper alloy is 60-75% IACS.

(Alloy D)
Ni: 0.5-3 mass%, Sn: 0.2-2 mass%, P: 0.02-0.2 mass%, Ag, B, Co, Cr, Fe, Mg, Mn, Si, Ti, It is a copper alloy containing 0 to 0.2 mass% in total of one or more of Zn and Zr. The conductivity of this copper alloy is 30-60% IACS. More preferable component ranges are 0.8 to 1.2% by mass of Ni, 0.4 to 0.6% by mass of Sn, 0.05 to 0.15% by mass of P, Ag, B, Co, Cr, A copper alloy containing at least one of Fe, Mg, Mn, Si, Ti, Zn and Zr in a total amount of 0 to 0.2% by mass, the balance being copper and its inevitable impurities, and Ni of 0.8 -1.2 mass%, Sn 0.8-1.0 mass%, P 0.05-0.15 mass%, Ag, B, Co, Cr, Fe, Mg, Mn, Si, Ti, Zn And one or more of Zr in a total of 0 to 0.2% by mass, the balance being copper alloy consisting of copper and its inevitable impurities, and the conductivity of each copper alloy is 45 to 55% IACS and 35 to 45 % IACS.

(Alloy E)
0.2 to 1% by mass of Mg, 0.001 to 0.1% by mass of P, one or more of Ag, B, Co, Cr, Fe, Mn, Ni, Si, Sn, Ti, Zn and Zr Is a copper alloy containing 0 to 0.2% by mass in total with the balance being copper and its inevitable impurities. The conductivity of this copper alloy is 50-70% IACS. More preferable components are 0.5 to 0.9% by mass of Mg, 0.001 to 0.02% by mass of P, Ag, B, Co, Cr, Fe, Mn, Ni, Si, Sn, Ti, Zn One or more of Zr and Zr are contained in a total of 0 to 0.2% by mass, and the balance is copper and its inevitable impurities. The copper alloy has a conductivity of 50 to 65% IACS.

(Alloy F)
1 to 15% by mass of Zn, 0 to 0.5% by mass in total of one or more of Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Sn, Ti and Zr The balance is a copper alloy composed of copper and its inevitable impurities. The conductivity of this copper alloy is 30-70% IACS. More preferable components are 7-9 mass% of Zn, 0.2-0.4 mass% of Sn, Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Ti and Zr. 1 to 0.2% by mass in total, the balance being copper and copper inevitable impurities, and 2 to 4% by mass of Zn, 0.1 to 0.3% by mass of Sn, Ag-, B-, Co-, Cr-, Fe-, Mg-, Mn-, Ni-, P-, Si-, Ti- and Zr-containing one or more in total, 0 to 0.2% by mass, with the remainder from copper and its inevitable impurities Each copper alloy has a conductivity of 35 to 45% IACS and 55 to 65% IACS.

(Alloy G)
0.1 to 5% by mass of Ni, 0.01 to 0.3% by mass of P, 0.01 to 0.3% by mass of Fe, 0.01 to 0.3% by mass of Zn, Ag, B, It is a copper alloy containing one or more of Co, Cr, Mg, Mn, Si, Sn, Ti, Zn, and Zr in a total amount of 0 to 0.2% by mass, and the balance being copper and its inevitable impurities. The conductivity of this copper alloy is 50-90% IACS. More preferable component ranges are 0.5 to 0.9 mass% for Ni, 0.02 to 0.2 mass% for P, 0.05 to 0.15 mass% for Fe, and 0.03 to 0.3 mass for Zn. 2% by mass, Ag, B, Co, Cr, Mg, Mn, Si, Sn, Ti and Zr are contained in a total of 0 to 0.2% by mass, with the balance being made of copper and its inevitable impurities The copper alloy has a conductivity of 60 to 80% IACS.

  As the concentration of the alloy component increases, the electrical conductivity decreases while the tensile strength increases.

(Crystal orientation)
The copper alloy plate according to the embodiment of the present invention has an area ratio of a crystal whose angle of (122) plane normal to TD is 10 degrees or less and an angle of (133) plane normal to TD. The total area ratio (hereinafter referred to as A value) with the area ratio of the crystal of 10 degrees or less is adjusted to 10% or more, more preferably 15% or more.

  The A value is obtained by an EBSD (Electron Back Scatter Diffraction) method in a cross section orthogonal to the TD of the rolled material. Here, EBSD is a technique for analyzing crystal orientation using reflected electron Kikuchi line diffraction (Kikuchi pattern) generated when a sample is irradiated with an electron beam in a SEM (Scanning Electron Microscope).

  When the A value is adjusted to 10% or more, the bending deflection coefficient of TD becomes 115 GPa or more, and at the same time, the stress relaxation characteristics are improved. The upper limit value of the A value is not limited in terms of the bending deflection coefficient of the TD, but the A value often takes a value of 60% or less.

  When the spring limit value (Kb) of TD and the tensile strength in the rolling direction are (σ), “σ−Kb” is preferably adjusted to 250 MPa or less, and more preferably 200 MPa or more. In addition to adjusting the A value to 10% or more, by adjusting “σ−Kb” to 250 MPa or less, the stress relaxation rate becomes 50% or less. The upper limit value of “σ−Kb” is not limited in terms of the characteristics of the copper alloy sheet, but “σ−Kb” is rarely a value of 0 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 current-carrying part will decrease and heat generation will increase during energization, making it unsuitable as a material for connectors that carry large currents. 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 is suitably used for applications of electronic parts such as terminals, connectors, relays, switches, sockets, bus bars, lead frames, heat sinks, etc. used in electric / electronic devices, automobiles, etc. In particular, applications of high-current electronic components such as connectors and terminals for large currents used in electric vehicles, hybrid vehicles, etc., or uses of electronic components for heat dissipation such as liquid crystal frames used in smartphones and tablet PCs Useful for.

(Production method)
As a pure copper material, electrolytic copper or the like is melted, an alloy element is added, and cast into an ingot having a thickness of about 30 to 300 mm. After this ingot is made into a plate having a thickness of about 3 to 30 mm by hot rolling, cold rolling and recrystallization annealing are repeated to finish to a predetermined product thickness by final cold rolling, and finally strain relief annealing is performed. The method of adjusting the A value to 10% or more is not limited to a specific method, but can be achieved by controlling the hot rolling conditions, for example.

In the hot rolling of the present invention, an ingot heated to 850 to 1000 ° C. is repeatedly passed between a pair of rolling rolls to finish the target plate thickness. The degree of processing per pass affects the A value. Here, 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) Thickness before passing through roll, T: Thickness after passing through rolling roll).

  Regarding R, it is preferable that the maximum value (Rmax) of all paths is 25% or less and the average value (Rave) of all paths is 20% or less. By satisfying both of these conditions, the A value becomes 10% or more. More preferably, Rave is set to 19% or less.

  In recrystallization annealing, part or all of the rolling structure is recrystallized. In recrystallization annealing (final recrystallization annealing) before 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 becomes difficult to adjust the tensile strength to 300 MPa or more.

  The conditions for final recrystallization annealing are determined based on the target crystal grain size after annealing. Specifically, annealing may be performed by using a batch furnace or a continuous annealing furnace and setting the furnace temperature to 250 to 800 ° C. In a batch furnace, the heating time may be appropriately adjusted within the range of 30 minutes to 30 hours at a furnace temperature of 250 to 600 ° C. 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.

In the final cold rolling, the material is repeatedly passed between a pair of rolling rolls to finish the target plate thickness. The workability of the final cold rolling is preferably 10 to 99%. Here, the working degree r (%) is given by r = (t ₀ −t) / t ₀ × 100 (t ₀ : plate thickness before rolling, t: plate thickness after rolling). If r is too small, it becomes difficult to adjust the tensile strength to 300 MPa or more. If r is too large, the edge of the rolled material may be broken.

  In addition to adjusting the A value by controlling the hot rolling conditions, the stress relaxation rate is 50% or less by adjusting the “σ-Kb” of the product to 250 MPa or less. The method of adjusting “σ−Kb” to 250 MPa or less is not limited to a specific method, but it can be performed, for example, by performing strain relief annealing under appropriate conditions after the final cold rolling.

  That is, by adjusting the tensile strength after strain relief annealing to a value that is 10 to 100 MPa lower, preferably 20 to 80 MPa lower than the tensile strength before strain relief annealing (after final rolling), “σ-Kb”. Is 250 MPa or less. If the amount of decrease in tensile strength is too small, it is difficult to adjust “σ−Kb” to 250 MPa. If the amount of decrease in tensile strength is too large, the tensile strength of the product may be less than 300 MPa.

  Specifically, when a batch furnace is used, the heating time is appropriately adjusted in the range of 30 minutes to 30 hours at a furnace temperature of 100 to 500 ° C., and when a continuous annealing furnace is used, 300 to 700 ° C. What is necessary is just to adjust the fall amount of tensile strength to the said range by adjusting a heating time suitably in the range for 5 second to 10 minutes in the furnace temperature of this.

  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 plate after hot rolling, annealing and cold rolling were repeated and finished to a predetermined product thickness by final cold rolling. Finally, strain relief annealing was performed.

  In hot rolling, the maximum value (Rmax) and average value (Rave) of the degree of processing per pass were variously changed.

  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 250 to 700 ° C., and the crystal grain size after annealing is 5 to 20 μm. The range was adjusted. The crystal grain size here is an average crystal grain size measured according to the cutting method of JIS H 0501 (1999) in a cross section orthogonal to the rolling direction.

  In the final cold rolling, the degree of work (r) was varied. In strain relief annealing, a continuous annealing furnace was used, the furnace temperature was 500 ° C., the heating time was adjusted between 1 second and 10 minutes, and the amount of decrease in tensile strength was variously changed. In some examples, strain relief annealing was not performed.

The following measurements were performed on materials during manufacture and materials (products) after strain relief annealing (after the final cold rolling in Examples where strain relief annealing was not performed).
(component)
The alloy element concentration of the material after strain relief annealing was analyzed by ICP-mass spectrometry.

(Crystal orientation of the product)
About the material after strain relief annealing, the electron beam was irradiated to the cross section (cross section parallel to a thickness direction and a rolling direction) orthogonal to TD, and the EBSD measurement was performed. The measurement area was 0.1 mm ^2, and scanning was performed in 2 μm steps to analyze the orientation. Then, an area ratio of the crystal whose angle formed by the normal of the (122) plane and TD is 10 degrees or less and an area ratio of the crystal whose angle formed by the normal of the (133) plane and TD are 10 degrees or less are obtained, The total (A value) of both area ratios was calculated.

(Tensile strength)
With regard to the material after strain relief annealing, a specimen No. 13B specified in JIS Z2241 was taken so that the tensile direction was parallel to the rolling direction, and a tensile test was performed in parallel with the rolling direction in accordance with JIS Z2241, and the rolling direction Tensile strength was determined.

(Spring limit value)
A strip-shaped specimen having a width of 10 mm was taken from the material after strain relief annealing so that the longitudinal direction of the specimen was perpendicular to the rolling direction, and a TD spring was obtained by a moment type test specified in JIS H3130. The limit value 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.

(Bending deflection coefficient)
For the material after strain relief annealing, the bending deflection coefficient of TD was measured according to the Japan Copper and Brass Association (JACBA) technical standard “Method of measuring bending deflection coefficient by cantilever of copper and copper alloy strip”.
A strip-shaped test piece having a thickness t and a width w (= 10 mm) was taken so that the longitudinal direction of the test piece was orthogonal to the rolling direction. One end of this sample was fixed, a load of P (= 0.15 N) was applied to a position L (= 100 t) from the fixed end, and a bending deflection coefficient B was obtained from the deflection d at this time using the following equation.
B = 4 · P · (L / t) ³ / (w · d)

(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 orthogonal to the rolling direction. As shown in FIG. 1, a stress corresponding to 80% of the 0.2% proof stress (measured in accordance with JIS Z2241) of TD is given to the test piece with a deflection of y ₀ with the position of l = 50 mm as the working point. s) was loaded. y0 was determined by the following equation.
y ₀ = (2/3) · l ² · s / (E · t)
Here, E is the bending deflection coefficient of TD, 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.

  Tables 1, 2, 3, 4, 5, 6 and 7 are examples relating to Alloy A, Alloy B, Alloy C, Alloy D, Alloy E, Alloy F and Alloy G, respectively. Table 8 shows examples of alloys other than those described in Tables 1-6. Moreover, in Table 9, the thing of the invention example 1, invention example 4, the comparative example 1, and the comparative example 2 of Tables 1-7 are shown as finishing thickness of each material in each pass of hot rolling, and the workability per pass. Illustrated.

  In the copper alloy sheets of Invention Examples 1 to 9 in Tables 1 to 7 and Invention Examples 1 to 19 in Table 8, Rmax was 25% or less and Rave was 20% or less in hot rolling, so the A value was 10% or more. A bending deflection coefficient of 115 GPa or more was obtained.

  Furthermore, in the copper alloy sheets of Invention Examples 1 to 7 in Tables 1 to 7 and Invention Examples 1 to 19 in Table 8, the tensile strength was reduced by 10 to 100 MPa in the strain relief annealing after the final rolling, so that “σ-Kb ”Was 250 MPa or less, and as a result, a stress relaxation rate of 50% or less was also obtained. On the other hand, Invention Example 9 in Tables 1 to 7 had a tensile strength reduction amount of less than 10 MPa in strain relief annealing, and Invention Example 8 in Tables 1 to 7 did not perform strain relief annealing. -Kb "exceeded 250 MPa, and as a result, the stress relaxation rate exceeded 50%.

  In Comparative Examples 1 to 3 in Tables 1 to 7, Rmax or Rave deviated from the definition of the present invention, so the A value was less than 10%. As a result, the bending deflection coefficient was less than 115 GPa. Furthermore, despite the fact that “σ-Kb” was adjusted to 250 MPa or less by performing strain relief annealing under conditions where the tensile strength was reduced by 10 to 100 MPa, the stress relaxation rate exceeded 50%.

Claims (11)

  One or more of Ag, P, Sn, Fe and Ni are contained in a total amount of 0.005 to 0.2% by mass, and the balance is made of copper and its inevitable impurities, and has a conductivity of 80 to 102% IACS and 300 MPa or more. The area of a crystal having a tensile strength and having an angle formed by the normal of the (122) plane and TD of 10 degrees or less when EBSD measurement is performed in a cross section perpendicular to the sheet width direction (TD) of the rolled material. The sum of the ratio and the area ratio of the crystal whose angle formed by the normal of the (133) plane and TD is 10 degrees or less is 10% or more, and the spring limit value (Kb) and tensile strength (σ) of TD The difference (σ−Kb) in the copper alloy plate is adjusted to 250 MPa or less.   Cr is 0.1 to 0.5% by mass, Sn is 0.1 to 0.5% by mass, Zn is 0.1 to 0.5% by mass, Ag, B, Co, Fe, Mg, Mn, Ni, One or more of P, Si, Ti and Zr are contained in a total amount of 0 to 0.2% by mass, the balance is made of copper and its inevitable impurities, the conductivity of 70 to 90% IACS and the tensile strength of 300 MPa or more. When the EBSD measurement is performed on a cross section perpendicular to the sheet width direction (TD) of the rolled material, the area ratio of the crystal whose normal line of the (122) plane forms TD is 10 degrees or less and The sum of the area ratio of the crystal whose angle formed by the normal of the (133) plane and TD is 10 degrees or less is 10% or more, and the spring limit value (Kb) of TD and the tensile strength (σ) A copper alloy sheet, wherein the difference (σ−Kb) is adjusted to 250 MPa or less.   Fe 1 to 3 mass%, P 0.01 to 0.2 mass%, Zn 0.05 to 0.5 mass%, Ag, B, Co, Cr, Mg, Mn, Ni, Si, Sn, One or more of Ti and Zr are contained in a total amount of 0 to 0.2% by mass, the balance is made of copper and its inevitable impurities, and has a conductivity of 60 to 80% IACS and a tensile strength of 300 MPa or more. When the EBSD measurement is performed in a cross section orthogonal to the plate width direction (TD) of the rolled material, the area ratio of the crystal whose (122) normal to the TD is 10 degrees or less, and (133) The sum of the area ratio of the crystal whose angle between the normal of the surface and TD is 10 degrees or less is 10% or more, and the difference between the spring limit value (Kb) of TD and the tensile strength (σ) (σ− A copper alloy plate characterized in that Kb) is adjusted to 250 MPa or less.   Ni: 0.5-3 mass%, Sn: 0.2-2 mass%, P: 0.02-0.2 mass%, Ag, B, Co, Cr, Fe, Mg, Mn, Si, Ti, One or more of Zn and Zr are contained in a total amount of 0 to 0.2% by mass, the balance is made of copper and its inevitable impurities, has a conductivity of 30 to 60% IACS and a tensile strength of 300 MPa or more. When the EBSD measurement is performed in a cross section orthogonal to the plate width direction (TD) of the rolled material, the area ratio of the crystal whose (122) normal to the TD is 10 degrees or less, and (133) The sum of the area ratio of the crystal whose angle between the normal of the surface and TD is 10 degrees or less is 10% or more, and the difference between the spring limit value (Kb) of TD and the tensile strength (σ) (σ− A copper alloy plate characterized in that Kb) is adjusted to 250 MPa or less.   0.2 to 1% by mass of Mg, 0.001 to 0.1% by mass of P, one or more of Ag, B, Co, Cr, Fe, Mn, Ni, Si, Sn, Ti, Zn and Zr Is contained in a total of 0 to 0.2% by mass, and the balance is made of copper and its inevitable impurities, has a conductivity of 50 to 70% IACS and a tensile strength of 300 MPa or more, and the width direction of the rolled material ( When the EBSD measurement is performed in a cross section orthogonal to (TD), the area ratio of the crystal whose (122) plane normal and TD form an angle of 10 degrees or less, and the (133) plane normal forms TD The sum of the area ratio of the crystals having an angle of 10 degrees or less is 10% or more, and the difference (σ−Kb) between the spring limit value (Kb) of TD and the tensile strength (σ) is adjusted to 250 MPa or less. A copper alloy sheet characterized by that.   1 to 15% by mass of Zn, 0 to 0.5% by mass in total of one or more of Ag, B, Co, Cr, Fe, Mg, Mn, Ni, P, Si, Sn, Ti and Zr The balance is made of copper and its inevitable impurities, and has an electrical conductivity of 30 to 70% IACS and a tensile strength of 300 MPa or more, and an EBSD measurement was performed on a cross section perpendicular to the plate width direction (TD) of the rolled material. In this case, the area ratio of the crystal whose angle between the normal of the (122) plane and TD is 10 degrees or less, and the area ratio of the crystal whose angle between the normal of the (133) plane and TD is 10 degrees or less, A copper alloy sheet characterized in that the difference between the spring limit value (Kb) of TD and the tensile strength (σ) (σ−Kb) is adjusted to 250 MPa or less.   0.1 to 5% by mass of Ni, 0.01 to 0.3% by mass of P, 0.01 to 0.3% by mass of Fe, Ag, B, Co, Cr, Mg, Mn, Si, Sn, One or more of Ti, Zn, and Zr is contained in a total of 0 to 0.2 mass%, the balance is made of copper and its inevitable impurities, and has a conductivity of 50 to 90% IACS and a tensile strength of 300 MPa or more. And when the EBSD measurement is performed in a cross section orthogonal to the sheet width direction (TD) of the rolled material, the area ratio of the crystal whose (122) normal to the TD is 10 degrees or less, and ( 133) The total of the area ratio of the crystal whose angle between the normal of the plane and TD is 10 degrees or less is 10% or more, and the difference between the spring limit value (Kb) of TD and the tensile strength (σ) ( A copper alloy sheet, wherein σ-Kb) is adjusted to 250 MPa or less.   The copper alloy plate according to any one of claims 1 to 7, wherein a bending deflection coefficient in the plate width direction is 115 GPa or more.   The bending deflection coefficient in the plate width direction is 115 GPa or more, and the stress relaxation rate in the plate width direction after holding at 150 ° C for 1000 hours is 50% or less, according to any one of claims 1 to 7. Copper alloy plate.   The electronic component for large currents using the copper alloy plate of any one of Claims 1-9.   The electronic component for heat dissipation using the copper alloy plate of any one of Claims 1-9.

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