JP2012046810A - Copper alloy sheet material and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy sheet material excellent in electrical conductivity, strength and bendability, and to provide a method for manufacturing the copper alloy sheet material in which the copper alloy sheet material can be manufactured by a simple process at low cost.SOLUTION: A cast slab obtained by melting and casting a raw material of a copper alloy having a composition containing, by mass, 1.0-4.0% Ni and 0.3-1.0% Si, and the balance being Cu and inevitable impurities, is subjected to hot rolling or homogenization, followed by aging treatment at 450-600°C for 1-20 hours, cold rolling at a rolling rate of 90% or more, and then low temperature annealing at 300-430°C for 1-48 hours.

Description

  The present invention relates to a copper alloy sheet and a method for manufacturing the same, and more particularly, to a Cu—Ni—Si based copper alloy sheet suitable for a current-carrying component of an electrical and electronic device such as a connector, a lead frame, a relay, and a switch, and a method for manufacturing the same.

  Materials used for electrical and electronic parts as current-carrying parts such as connectors, lead frames, relays, and switches are required to have good conductivity in order to suppress the generation of Joule heat due to current conduction. It is required to have a high strength that can withstand the stress applied during assembly and operation of the device. In addition, since these current-carrying parts are generally produced by a forming process such as a bending process of a plate material, it is also required to have excellent workability.

  However, since there is generally a trade-off relationship between the strength and conductivity of the copper alloy sheet and between the strength and workability, it is not easy to improve these characteristics simultaneously.

  In order to increase the strength while maintaining high conductivity of the copper alloy sheet, it is known to use precipitation strengthening. Conventionally, Cu—Cr (—Zr), Cu—Fe—P, Cu— Plate materials of precipitation-strengthened alloys such as Mg—P and Cu—Ni—Si have been put into practical use. In recent years, among these copper alloy sheet materials, a Cu-Ni-Si alloy (so-called Corson alloy) sheet material has attracted attention as a material having an excellent balance between strength and electrical conductivity.

  However, the precipitation-strengthened copper alloy sheet generally includes many steps of hot rolling, cold rolling, solution treatment, cold rolling, aging treatment, finish rolling and low-temperature annealing to improve the characteristics and There is a problem that the manufacturing cost is increased because the manufacturing process is very strict in the management of each process condition.

  In addition, as a method for producing a precipitation-strengthened copper alloy sheet, a method is proposed in which heat treatment (such as solution treatment, annealing, aging treatment) is performed as many times as necessary, and heat treatment and cold rolling are repeated. For example, in the solution treatment process (that is, a process in which an alloy is heated and maintained in a high temperature region above the solid solution limit temperature and then rapidly cooled to form a supersaturated solid solution), uniformity of temperature distribution during heating and rapid cooling are required. A large dedicated solution treatment furnace is required. In addition, the control of solution conditions is very strict. When the solution temperature is low, recrystallization does not occur or recrystallization occurs partially, so that a uniform recrystallization structure cannot be obtained. In addition, the amount of Ni and Si dissolved in the Cu matrix decreases, and it becomes difficult to sufficiently generate fine Ni—Si based precipitates in the aging treatment of the next step. On the other hand, when the solution temperature is high, the crystal grains are likely to be coarsened in a short time, and the bending workability of the copper alloy sheet as the final product is lowered. That is, the control condition of the solution condition is narrow, and if it deviates even a little, characteristic variations are likely to occur.

  In addition, when a Cu-Ni-Si alloy plate was produced by a conventional production method including solution treatment, cold rolling, and aging treatment, the strength of the plate material increased with the passage of aging time, and passed a certain peak point. Later, it decreases monotonically (that is, it becomes an overaged state of coarsening of precipitates). For example, if the tensile strength of the plate material is increased to about 700 MPa, the conductivity decreases to 30 to 40% IACS, whereas if the conductivity is increased to 50% IACS or more, the tensile strength decreases to 600 MPa or less. End up. That is, it is difficult to obtain a copper alloy sheet having high strength (for example, 650 MPa or more) while maintaining high conductivity (for example, 50% IACS or more) by precipitation strengthening.

  Further, if cold rolling and low-temperature annealing are further performed after the aging treatment, the tensile strength can be improved, but generally the workability (particularly, BadWay bending workability with the rolling direction as the bending axis) is deteriorated.

  Proposed method to produce precipitation-strengthened copper alloy sheet by cold rolling thin slab and then aging treatment as a method to reduce production cost by reducing production process of Cu-Ni-Si alloy sheet (For example, refer to Patent Document 1). In addition, as a method for simultaneously improving the conductivity and strength of the Cu—Ni—Si based alloy sheet, a method of performing aging treatment a plurality of times (for example, see Patent Document 2), a method of repeating cold rolling and aging treatment (for example, , See Patent Document 3).

JP-A-9-176808 (paragraph number 0008) JP-A-10-152737 (paragraph number 0007-0010) JP-A-7-41887 (paragraph number 0024-0030)

  However, in the method of Patent Document 1, although the conductivity of the copper alloy sheet can be set to 50 to 60% IACS, the hardness is limited to about Hv 200 to 140 (estimated tensile strength 650 to 450 MPa). In addition, in the methods of Patent Documents 2 and 3, workability cannot be improved at the same time, and the manufacturing cost increases due to an increase in the number of steps.

  In addition, as described above, the plate material of Cu—Ni—Si alloy is manufactured by a manufacturing method that includes many steps and has extremely strict management of each process condition in order to improve the characteristics, and the manufacturing cost is low. There is a problem of becoming higher. Further, in the conventional method for producing a copper alloy sheet, it is possible to simultaneously improve the strength, conductivity and bending workability even if the process conditions are appropriate. For example, the conductivity is 50% IACS or more and the tensile strength is 650 MPa or more. In addition, Good Way bending (GW bending) with TD (direction perpendicular to the rolling direction and the plate thickness direction) as a bending axis and Bad Way bending (B.W with LD (rolling direction) as a bending axis). The ratio R / t of the minimum bending radius R at which cracks do not occur and the thickness t of the copper alloy sheet material after making a 90 ° W bending test in accordance with JIS H3110 of. Have difficulty.

  Accordingly, in view of such conventional problems, the present invention provides a copper alloy sheet material having good conductivity, strength and bending workability, and a copper alloy sheet material that can be produced at low cost by a simple process. It aims at providing the manufacturing method of.

  As a result of diligent research to solve the above problems, the inventors of the present invention contain 1.0 to 4.0% by mass of Ni and 0.3 to 1.0% by mass of Si, with the balance being Cu and inevitable impurities. A slab obtained by melting and casting a copper alloy raw material having a composition comprising: hot rolling or homogenizing treatment, followed by aging treatment at 450 to 600 ° C. for 1 to 20 hours, and then rolling After performing cold rolling at a rate of 90% or more, low temperature annealing at 300 to 430 ° C. for 1 to 48 hours makes it possible to inexpensively produce a copper alloy sheet material with good conductivity, strength and bending workability The inventors have found that it can be manufactured and have completed the present invention.

  That is, the method for producing a copper alloy sheet according to the present invention has a composition containing 1.0 to 4.0% by mass of Ni and 0.3 to 1.0% by mass of Si, with the balance being Cu and inevitable impurities. After hot-rolling or homogenizing the slab obtained by melting and casting the copper alloy raw material, it is subjected to aging treatment at 450 to 600 ° C. for 1 to 20 hours, and then at a rolling rate of 90% or more. After cold rolling, low temperature annealing is performed at 300 to 430 ° C. for 1 to 48 hours.

  In this method for producing a copper alloy sheet, it is preferable to perform an aging treatment so that the electrical conductivity is 40% IACS or more and the Vickers hardness is Hv150 or more after the aging treatment. The composition of the raw material of the copper alloy may further include 0.01 to 0.3% by mass of Mg, and is composed of Sn, Zn, Co, Cr, P, B, Al, Fe, Zr, Ti, and Mn. One or more elements selected from the group may be further included in a total range of 3% by mass or less.

  Further, the copper alloy sheet according to the present invention has a composition containing 1.0 to 4.0% by mass of Ni and 0.3 to 1.0% by mass of Si, with the balance being Cu and inevitable impurities, It has a fine grain structure with an average crystal grain size of 1 μm or less with a grain boundary having a difference of 5 ° or more as a grain boundary.

  This copper alloy sheet has a minimum bending radius R and a copper alloy sheet that has a conductivity of 50% IACS or more, a tensile strength of 650 MPa or more, and does not crack after performing a 90 ° W bending test in accordance with JIS H3110. The ratio R / t with respect to the thickness t is preferably 2.0 or less. The conductivity is preferably 55% IACS or more, and more preferably 60% IACS or more. Further, the tensile strength is preferably 700 MPa or more, more preferably 750 MPa or more, and further preferably 800 MPa or more. Moreover, it is preferable that R / t is 1.0 or less, and it is further more preferable that it is 0.5 or less. Further, the composition of the copper alloy sheet may further include 0.01 to 0.3% by mass of Mg, and the group consisting of Sn, Zn, Co, Cr, P, B, Al, Fe, Zr, Ti, and Mn. One or more elements selected from may be further included within a total range of 3% by mass or less.

  ADVANTAGE OF THE INVENTION According to this invention, a copper alloy board | plate material with favorable electroconductivity, intensity | strength, and bending workability can be manufactured cheaply with a simple process.

  The present inventors use various precipitation-strengthened copper alloys such as Cu-Ni-Si alloy, omitting the solution treatment that was necessary in the conventional method for producing a plate of precipitation-strengthened copper alloy. Research has been conducted on methods for improving productivity and reducing costs by simplifying the process and improving the conductivity, strength, and workability of the copper alloy sheet. As a result, a slab of a Cu—Ni—Si alloy having a predetermined composition (an aging precipitation type copper-based alloy to which Ni and Si are added) is hot-worked or homogenized, and then a solution treatment is not performed. A copper alloy sheet having improved conductivity, strength and workability by performing aging treatment, cold working and low-temperature annealing in this order, in particular, conductivity is 50% IACS or more, and tensile strength is 650 MPa or more. And a copper alloy sheet material having an excellent characteristic that the ratio R / t of the minimum bending radius R and the thickness t is 2.0 or less so that no cracks occur after performing a 90 ° W bending test in accordance with JIS H3110. It was found that can be manufactured.

  Generally, when a copper alloy is cold worked, dislocations are introduced and work hardening occurs. Dislocations are not uniformly distributed, and dislocation cells are formed by entanglement of dislocations. The higher the density of dislocations introduced, the smaller the size of the dislocation cells. When a cold-worked copper alloy is heated, dislocation cells change into subgrains due to recovery, and the orientation difference between subcrystal grains increases. In the normal recrystallization mechanism, which occurs by recrystallization annealing after cold rolling of a copper alloy, the sub-crystal grains grow with themselves as nuclei and become recrystallized grains. This is called “recrystallization” and the strength of the copper alloy sheet is lowered by the occurrence of the discontinuous recrystallization. If the heating temperature after the copper alloy is cold-rolled is relatively low, the dislocation cells change into subgrains due to recovery, and the orientation difference between the subgrains increases. become. In this case, since the recrystallized grains are generated by continuous increase in the orientation difference of the sub-crystal grains, this phenomenon of recrystallization is called “continuous recrystallization”, and the recrystallized grains are equivalent to the sub-crystal grains. Therefore, it is possible to reduce the size to 1 μm or less. In this way, a fine grain structure is formed by the occurrence of continuous recrystallization. When continuous recrystallization occurs, there is little decrease in strength of the copper alloy sheet, and if the orientation difference of the copper alloy sheet exceeds a certain critical value, the ductility and bending workability of the copper alloy sheet are dramatically improved. As a result of intensive studies by the present inventors, it has been found that when the orientation difference of a copper alloy sheet is 5 ° or more, the ductility and bending workability of the copper alloy sheet are greatly improved.

  Embodiment of the manufacturing method of the copper alloy sheet | seat material by this invention contains 1.0-4.0 mass% Ni and 0.3-1.0 mass% Si, and the remainder consists of Cu and an unavoidable impurity. A process for obtaining a slab by melting and casting a raw material of a copper alloy having melting (melting / casting process), and a process for hot rolling or homogenizing the obtained slab (hot rolling or homogenizing process) Step), a step of aging treatment at 450 to 600 ° C. for 1 to 20 hours after this hot rolling or homogenization treatment step (aging treatment step), and cold rolling at a rolling rate of 90% or more after this aging treatment step. A step of performing (cold rolling step) and a step of performing low temperature annealing at 300 to 430 ° C. for 1 to 48 hours after the cold rolling step (low temperature annealing step).

  In the embodiment of the method for producing a copper alloy sheet according to the present invention, first, the crystallization phase generated in the casting process is eliminated by hot working or homogenization treatment, and the cast structure is destroyed by recrystallization to obtain a uniform recrystallization. Generate a grain structure. Next, by conducting an aging treatment in the precipitation temperature range, the conductivity and strength can be improved by the formation of precipitates. Furthermore, if the cold working is performed in a state having precipitates, the strength of the copper alloy sheet can be remarkably improved. In this rolled structure state, both the strength and the conductivity of the copper alloy sheet are increased, but generally the bending workability is significantly reduced. Therefore, the present inventors have intensively studied, and by conducting a low temperature annealing for a long time at a low temperature on a plate that has been strongly processed with precipitates, the strength of the copper alloy plate is reduced and the conductivity is improved. In particular, it has been found that the bending workability can be remarkably improved, and as a result, it is possible to realize a structure state in which conductivity, strength and workability are improved.

  Hereinafter, each process of embodiment of the manufacturing method of the copper alloy board | plate material by this invention is demonstrated in detail.

(Alloy composition)
When Ni and Si are added as raw materials for a copper alloy sheet, a precipitate mainly composed of a compound of Ni and Si (Ni-Si based precipitate) is formed, and the solid solution amount of Ni and Si is reduced, resulting in high conductivity. It has the effect of improving the strength while maintaining. When the Ni content is less than 1.0% by mass or when the Si content is less than 0.3% by mass, it is difficult to exert this effect sufficiently. On the other hand, when the Ni content exceeds 4.0% by mass or the Si content exceeds 1.0% by mass, the electrical conductivity is lowered (because precipitates are easily coarsened), and hot workability is achieved. Is significantly reduced. Therefore, Ni content is 1.0-4.0 mass%, it is preferable that it is 1.5-3.5 mass%, and it is more preferable that it is 2.0-3.0 mass%. Moreover, Si content is 0.3-1.0 mass%, it is preferable that it is 0.4-0.8 mass%, and it is more preferable that it is 0.5-0.7 mass%. Moreover, it is preferable that mass ratio (Ni / Si) of Ni and Si is 3.5-6.0. If it is out of this range, the amount of Ni or Si not dissolved in the formation of Ni—Si-based precipitates increases, and the conductivity may decrease.

  Moreover, you may further add 0.01-0.3 mass% Mg as a raw material of a copper alloy. Mg has an effect of preventing the coarsening of Ni—Si based precipitates and an effect of improving the stress relaxation resistance of the copper alloy sheet. In order to sufficiently exhibit these actions, it is preferable to set the Mg content to 0.01% by mass or more. However, if the Mg content exceeds 0.3% by mass, the castability and hot workability are remarkably lowered, and the cost is disadvantageous. % Or less is preferable.

  Further, as a raw material for the copper alloy, one or more elements selected from the group consisting of Sn, Zn, Co, Cr, P, B, Al, Fe, Zr, Ti, and Mn are further added in a total range of 3% by mass or less. It may be added. These elements have the effect of further increasing the strength of the copper alloy sheet and reducing the stress relaxation. In addition, Co, Cr, B, Zr, Ti, and Mn are easy to form a high melting point compound with S, Pb, etc. present as inevitable impurities, and have an effect of improving hot workability. Sn and Zn have the effect of improving cold workability. When these elements are added, it is preferable to add them so that the total amount is 0.01% by mass or more in order to sufficiently exert their effects. However, if the total amount exceeds 3% by mass, the hot workability or the cold workability may be lowered, and it is disadvantageous in terms of cost. Therefore, the total amount should be 3% by mass or less. It is preferably 2% by mass or less, more preferably 1% by mass or less, and most preferably 0.5% by mass or less.

(Melting and casting process)
A slab is produced by continuous casting or semi-continuous casting after the raw material of the copper alloy is melted by the same method as a general copper alloy melting method. The melting of the copper alloy raw material may be performed in the air atmosphere, but it is preferable to seal with an inert gas from the viewpoint of oxidation prevention. The continuous casting method may be vertical or horizontal.

(Hot rolling or homogenization process)
When a slab is manufactured by the vertical continuous casting method, the slab is hot-rolled. This hot rolling may be performed under normal hot rolling conditions (starting temperature 1000 to 850 ° C., finishing temperature 600 ° C. or more), but it is preferable to perform water cooling after the final pass. On the other hand, when the slab is manufactured by the horizontal continuous casting method, it is not necessary to perform hot rolling of the slab, but instead, a normal homogenization process (homogenization process at 1000 to 850 ° C. for about 1 to 20 hours) Is preferably performed.

(Aging process)
In the aging treatment, it is necessary to generate a certain amount of precipitates. It is possible to improve bending workability by accumulating a large amount of dislocations in the parent phase during the subsequent cold rolling and further generating continuous recrystallization during the subsequent low-temperature annealing. When the aging treatment temperature is too low or the aging treatment time is too short, the amount of precipitates produced is small and continuous recrystallization is insufficient. On the other hand, when the aging treatment temperature is too high or the aging treatment time is too long, the precipitates are coarsened, discontinuous recrystallization is likely to occur, and the copper alloy sheet is softened. Therefore, the aging treatment is preferably performed at 450 to 600 ° C. for 1 to 20 hours, more preferably 450 to 600 ° C. for 1 to 10 hours. In particular, the conductivity is 40% IACS or more after the aging treatment and the Vickers hardness is Hv150. It is preferable to select the temperature and time of the aging treatment so as to become the above. In addition, you may face the surface of a board | plate material after an aging treatment as needed.

(Cold rolling process)
Subsequently, cold rolling is performed at a rolling rate of 90% or more. In this cold rolling, the strength of the plate material can be improved and a large amount of dislocations can be introduced into the parent phase. If the rolling rate is too low, the density of dislocations introduced is insufficient, and the continuous recrystallization that occurs during subsequent low-temperature annealing is insufficient. Therefore, the rolling rate of cold rolling is preferably 90% or more, and more preferably 95% or more.

(Low temperature annealing process)
Finally, low temperature annealing is performed at 300 to 430 ° C. for 1 to 48 hours. Ordinary low-temperature annealing is performed for a relatively short time of several seconds to several minutes in order to remove residual stress, but low-temperature annealing is performed at a relatively low temperature range of 300 to 430 ° C., preferably 330 to 430 ° C. for 1 to 48 hours. Preferably, by performing for a relatively long time of 2 to 20 hours, the accumulated dislocations are converted to subgrain boundaries, and so-called continuous recrystallization is generated, thereby suppressing a decrease in strength of the copper alloy sheet. The electrical conductivity and bending workability, particularly bending workability can be improved. If the low-temperature annealing temperature is too high, recrystallization nucleation and grain growth, so-called discontinuous recrystallization, are likely to occur around the grain boundaries and precipitated particles, and the copper alloy sheet is softened. On the other hand, if the low-temperature annealing temperature is too low, the occurrence of continuous recrystallization is insufficient, or the necessary low-temperature annealing time must be lengthened, resulting in an increase in manufacturing cost.

  According to the embodiment of the method for producing a copper alloy sheet described above, a composition comprising 1.0 to 4.0 mass% Ni and 0.3 to 1.0 mass% Si, with the balance being Cu and inevitable impurities. And having a fine grain structure with an average crystal grain size of 1 μm or less with a grain boundary having an orientation difference of 5 ° or more as a grain boundary, and an electrical conductivity of 50% IACS or more, preferably 55% IACS or more, more preferably 60 % IACS or higher, tensile strength of 650 MPa or higher, preferably 700 MPa or higher, more preferably 750 MPa or higher, more preferably 800 MPa or higher. The ratio R / t between the bending radius R and the thickness t of the copper alloy sheet is 2.0 or less, preferably 1.5 or less, more preferably 1.0 or less, most preferably 0.5 or less. Can be produced copper alloy sheet is. The composition of the copper alloy sheet may further include 0.01 to 0.3% by mass of Mg, and includes a group consisting of Sn, Zn, Co, Cr, P, B, Al, Fe, Zr, Ti, and Mn. One or more selected elements may be further included within a total range of 3% by mass or less.

  Hereinafter, examples of the copper alloy sheet material and the manufacturing method thereof according to the present invention will be described in detail.

[Examples 1 to 10]
A copper alloy containing 2.45 mass% Ni and 0.51 mass% Si with the balance being Cu and inevitable impurities (Example 1), 2.48 mass% Ni and 0.50 mass% Si A copper alloy containing 0.15% by mass of Mg, the balance being Cu and inevitable impurities (Example 2), 2.75% by mass of Ni, 0.66% by mass of Si, 0.12% by mass of Mn, A copper alloy (Example 3) containing 0.08% by mass of Cr and the balance being Cu and inevitable impurities, 3.05% by mass of Ni, 0.73% by mass of Si, and 0.25% by mass of Sn A copper alloy containing 0.80% by mass of Zn, the balance being Cu and inevitable impurities (Example 4), 1.32% by mass of Ni, 0.62% by mass of Si and 1.06% by mass of Co A copper compound containing 0.02% by mass of P, with the balance being Cu and inevitable impurities (Example 5), a copper alloy containing 2.52% by mass of Ni, 0.54% by mass of Si, 0.005% by mass of B, and 0.16% by mass of Fe, with the balance being Cu and inevitable impurities (Example 6), a copper alloy containing 1.84% by mass of Ni, 0.48% by mass of Si and 0.08% by mass of Ti, with the balance being Cu and inevitable impurities (Example 7); A copper alloy (Example 8) containing 85 mass% Ni, 0.68 mass% Si and 0.06 mass% Zr, with the balance being Cu and inevitable impurities. A copper alloy containing 74% by mass of Si and the balance being Cu and inevitable impurities (Example 9), containing 2.20% by mass of Ni, 0.44% by mass of Si and 0.10% by mass of Al, Remaining copper alloys (Example 10) each consisting of Cu and inevitable impurities Papermaking, to obtain a cast piece of cross-sectional dimensions 100 mm × 250 mm by casting using a vertical size continuous casting machine.

  Each slab was heated to 950 ° C. and held for 1 hour, hot rolled while lowering the temperature from 950 ° C. to 650 ° C. to form a plate material having a thickness of 10 mm, and then rapidly cooled.

  Then, 450 ° C for 6 hours (Examples 1 and 6), 500 ° C for 3 hours (Example 2), 550 ° C for 2 hours (Example 3), and 475 ° C for 4 hours (Examples 4 and 8) An aging treatment was performed at 575 ° C. for 4 hours (Example 5), 525 ° C. for 5 hours (Example 7), 450 ° C. for 3 hours (Example 9), and 500 ° C. for 5 hours (Example 10). In addition, when the electrical conductivity of the plate material after the aging treatment was measured in accordance with the electrical conductivity measurement method of JIS H0505, 48.8% IACS (Example 1), 49.0% IACS (Example 2), and 43.8, respectively. % IACS (Example 3), 41.2% IACS (Example 4), 50.2% IACS (Example 5), 48.2% IACS (Example 6), 49.0% IACS (Example 7) ), 44.6% IACS (Example 8), 40.3% IACS (Example 9), and 49.2% IACS (Example 10). Moreover, when the Vickers hardness of the plate surface (rolled surface) of the plate material after the aging treatment was determined according to JIS Z2244, Hv190 (Example 1), Hv195 (Example 2), and Hv201 (Example 3), respectively. Hv212 (Example 4), Hv165 (Example 5), Hv178 (Example 6), Hv175 (Example 7), Hv196 (Example 8), Hv228 (Example 9), Hv181 (Example 10) there were.

  Subsequently, cold rolling was performed at a rolling rate of 98.5% to obtain a plate material having a thickness of 0.15 mm. When the Vickers hardness of the plate surface (rolled surface) of the plate material after the cold rolling was determined according to JIS Z2244, Hv234 (Example 1), Hv243 (Example 2), and Hv256 (Example 3), respectively. Hv275 (Example 4), Hv232 (Example 5), Hv242 (Example 6), Hv234 (Example 7), Hv254 (Example 8), Hv276 (Example 9), Hv235 (Example 10) there were.

  Then, 9 hours at 400 ° C. (Example 1), 3 hours at 425 ° C. (Example 2), 4 hours at 400 ° C. (Example 3), 9 hours at 375 ° C. (Example 4), at 425 ° C. 6 hours (Example 5), 400 ° C. for 5 hours (Examples 6, 8, 10), 400 ° C. for 8 hours (Example 7), 350 ° C. for 12 hours (Example 9) The copper alloy board | plate material of Examples 1-10 was obtained.

  Next, samples were collected from the copper alloy sheet materials obtained in these examples, and the average crystal grain size, electrical conductivity, tensile strength, hardness, elongation at break, and bending workability were examined as follows.

  The average crystal grain size of the copper alloy sheet was determined by polishing the plate surface (rolled surface) of the sample with # 1500 water-resistant paper and then finishing polishing by vibration polishing method so that polishing distortion does not enter the surface. Measured EBSP (Electron Backscatter Diffraction Pattern) by using a field emission scanning electron microscope (Field Emission Scanning Electron Microscope (FESEM) manufactured by JEOL Ltd.). The above grain boundaries are extracted (as crystal grain boundaries) to draw a grain orientation distribution map (OIM (Orientation Imaging Microscopy) image), and the total area of this grain orientation distribution map is divided by the number of crystal grains. Average of After obtaining the product, it was obtained as an average diameter when each crystal grain was a circle (calculation of such average crystal grain size should be automatically performed by software attached to a general EBSP measuring device. Can do). As a result, the average crystal grain sizes were 0.7 μm (Example 1), 0.9 μm (Example 2), 0.6 μm (Examples 3, 5, and 9), 0.4 μm (Example 4), It was 0.8 μm (Examples 6, 7, 8) and 0.5 μm (Example 10).

  The conductivity of the copper alloy sheet was measured according to the conductivity measurement method of JIS H0505. As a result, the electrical conductivity was 61.2% IACS (Example 1), 55.8% IACS (Example 2), 52.4% IACS (Example 3), and 51.3% IACS (Example 4), respectively. ), 60.6% IACS (Example 5), 53.6% IACS (Example 6), 60.8% IACS (Example 7), 55.1% IACS (Example 8), 52.8% IACS (Example 9) and 55.9% IACS (Example 10), both having good conductivity of 50% IACS or more.

  As an evaluation of the tensile strength and breaking elongation of the copper alloy sheet, specimens for tensile testing of the LD (rolling direction) of the copper alloy sheet (sample No. 5 of JIS Z2241) were collected, respectively, and tensile according to JIS Z2241 Tests were conducted to determine tensile strength and elongation at break. As a result, the tensile strengths were 688 MPa (Example 1), 726 MPa (Example 2), 765 MPa (Example 3), 816 MPa (Example 4), 718 MPa (Example 5), and 731 MPa (Example 6), respectively. 708 MPa (Example 7), 737 MPa (Example 8), 826 MPa (Example 9), and 716 MPa (Example 10), all of which were good copper alloy sheet materials having a tensile strength of 650 MPa or more. The elongation at break was 9.4% (Example 1), 8.1% (Example 2), 6.8% (Example 3), 5.3% (Example 4), 7.1, respectively. % (Example 5), 7.8 (Example 6), 8.7% (Example 7), 8.0% (Example 8), 7.7% (Example 9), 9.6% (Example 10), all of which were as good as 5% or more.

  As the hardness of the copper alloy plate material, the Vickers hardness of the plate surface (rolled surface) of the sample was determined in accordance with JIS Z2244. As a result, the Vickers hardness was Hv212 (Example 1), Hv225 (Example 2), Hv239 (Example 3), Hv255 (Example 4), Hv221 (Example 5), and Hv225 (Example 6), respectively. Hv219 (Example 7), Hv231 (Example 8), Hv258 (Example 9), and Hv220 (Example 10).

  In order to evaluate the bending workability of the copper alloy sheet, the bending test piece (width 10 mm) whose longitudinal direction is LD (rolling direction) and the longitudinal direction from the copper alloy sheet are TD (perpendicular to the rolling direction and the plate thickness direction). Direction) bending test pieces (width 10 mm) were sampled, and a 90 ° W bending test in accordance with JIS H3110 was performed on these test pieces with a bending radius R = 0.0 of the bending test jig. About the test piece after this bending test, after observing the surface and cross section of a bending process part by 50 time with an optical microscope and calculating | requiring the minimum bending radius R which a crack does not generate | occur | produce, this minimum bending radius R is made into a copper alloy. By dividing by the plate thickness t (= 0.15 mm) of the plate material, the Good Way bending with the bending direction of TD of the bending test piece whose LD is the longitudinal direction and the LD of the bending test piece of which the longitudinal direction is TD are the bending axis. Each R / t value of the Bad Way bending was determined. In addition, bending workability is so favorable that these values of R / t are small. As a result, the R / t values of GoodWay bending with TD as the bending axis and BadWay bending with LD as the bending axis are 0.0 and 0.0 (Example 1), 0.0 and 1.0 (respectively). Example 2), 0.7 and 1.7 (Example 3), 1.0 and 2.0 (Example 4), 0.0 and 1.0 (Example 5), 0.7 and 1. 0 (Example 6), 0.0 and 0.7 (Example 7), 0.0 and 1.0 (Example 8), 1.0 and 2.0 (Example 9), 0.0 1.0 (Example 10), and in all cases, the value of R / t of Bad Way bending was 2.0 or less and had good bending workability.

[Examples 11 to 15]
A copper alloy (Example 11) containing 2.34% by mass of Ni and 0.49% by mass of Si, with the balance being Cu and inevitable impurities, 2.50% by mass of Ni and 0.50% by mass of Si A copper alloy containing 0.15% by mass of Mg, the balance being Cu and unavoidable impurities (Example 12), containing 2.85% by mass of Ni and 0.70% by mass of Si, with the balance being Cu and unavoidable impurities A copper alloy (Example 13) comprising 1.34% by mass of Ni, 0.41% by mass of Si, 1.10% by mass of Co and 0.05% by mass of Mg, with the balance being Cu and inevitable impurities A copper alloy (Example 14) comprising 3.56% by mass of Ni and 0.78% by mass of Si, with the balance being Cu and unavoidable impurities (Example 15). Cast using a continuous casting machine and have a cross section of 14m × After obtaining the slab of 450 mm, and the respective billet for 6 hours homogenized at 950 ° C..

  Then at 475 ° C. for 6 hours (Example 11), at 525 ° C. for 3 hours (Example 12), at 575 ° C. for 2 hours (Example 13), at 500 ° C. for 4 hours (Example 14), at 600 ° C. An aging treatment was performed for 3 hours (Example 15). In addition, when the electrical conductivity of the plate material after the aging treatment was measured by the same method as in Examples 1 to 10, 50.4% IACS (Example 11), 48.4% IACS (Example 12), and 49, respectively. 2% IACS (Example 13), 43.4% IACS (Example 14), and 41.6% IACS (Example 15). Moreover, when the Vickers hardness of the plate surface (rolled surface) of the plate material after the aging treatment was determined by the same method as in Examples 1 to 10, Hv158 (Example 11), Hv192 (Example 12), and Hv182 ( Example 13), Hv215 (Example 14), and Hv222 (Example 15).

  Subsequently, cold rolling was performed at a rolling rate of 99.0% to obtain a plate material having a thickness of 0.15 mm. When the Vickers hardness of the plate surface (rolled surface) of the plate material after cold rolling was determined by the same method as in Examples 1 to 10, Hv218 (Example 11), Hv248 (Example 12), and Hv232 ( Example 13), Hv278 (Example 14), and Hv286 (Example 15).

  Then at 400 ° C. for 12 hours (Example 11), at 400 ° C. for 3 hours (Example 12), at 400 ° C. for 7 hours (Example 13), at 425 ° C. for 4 hours (Example 14), at 400 ° C. The low temperature annealing was performed for 2 hours (Example 15), and the copper alloy sheet materials of Examples 11 to 15 were obtained.

  Next, samples are taken from the copper alloy sheet materials obtained in these examples, and the average crystal grain size, conductivity, tensile strength, hardness, elongation at break, bending process are performed in the same manner as in Examples 1-10. The sex was examined.

  As a result, the average crystal grain sizes of the copper alloy sheets were 0.6 μm (Examples 11 and 12), 0.5 μm (Example 13), 0.7 μm (Example 14), and 0.4 μm (Example 15), respectively. )Met.

  The conductivity of the copper alloy sheet was 60.8% IACS (Example 11), 51.6% IACS (Example 12), 56.6% IACS (Example 13), and 55.8% IACS (Example), respectively. 14) 50.4% IACS (Example 15), all having good conductivity of 50% IACS or more.

  The tensile strengths of the copper alloy sheet materials were 678 MPa (Example 11), 756 MPa (Example 12), 708 MPa (Example 13), 809 MPa (Example 14), and 848 MPa (Example 15), respectively, and all were tensile. It was a good copper alloy sheet material having a strength of 650 MPa or more.

  The elongation at break of the copper alloy sheet was 10.5% (Example 11), 6.3% (Example 12), 8.6% (Example 13), 7.7% (Example 14), 5 6% (Example 5), both of which were good at 5% or more.

  The Vickers hardness of the copper alloy sheet was Hv208 (Example 11), Hv234 (Example 12), Hv222 (Example 13), Hv250 (Example 14), and Hv265 (Example 5), respectively.

  As an evaluation of the bending workability of the copper alloy sheet, R / t values of Good Way bending with TD as a bending axis and Bad Way bending with LD as a bending axis are 0.0 and 0.0, respectively (Example 11), 0.0 and 1.7 (Example 12), 0.0 and 0.7 (Example 13), 0.0 and 1.7 (Example 14), 1.0 and 2.0 (Example 5) In all cases, the R / t value of BadWay bending was 2.0 or less and had good bending workability.

[Comparative Example 1]
A copper alloy containing 0.94% by mass of Ni, 0.29% by mass of Si and 0.15% by mass of Mg, with the balance being Cu and unavoidable impurities is melted, and low-temperature annealing is performed at 375 ° C. for 6 hours. A copper alloy sheet was obtained in the same manner as in Example 1 except that. In addition, when the electrical conductivity of the plate material after the aging treatment was measured by the same method as in Examples 1 to 10, it was 50.6% IACS, and the Vickers hardness of the plate surface (rolled surface) of the plate material after the aging treatment was It was Hv114 when calculated | required by the method similar to Examples 1-10. Moreover, it was Hv193 when the Vickers hardness of the board surface (rolling surface) of the board | plate material after cold rolling was calculated | required by the method similar to Examples 1-10.

  Next, a sample was taken from the copper alloy sheet obtained in this comparative example, and the average crystal grain size, conductivity, tensile strength, hardness, elongation at break, bending workability were obtained in the same manner as in Examples 1-10. Investigated about. As a result, the average crystal grain size of the copper alloy sheet was 22 μm, the electrical conductivity was 63.2% IACS, the tensile strength was 588 MPa, the elongation at break was 12.2%, and the Vickers hardness was Hv182. The R / t values of Good Way bending with TD as the bending axis and Bad Way bending with LD as the bending axis were 0.0 and 2.0, respectively.

  In this comparative example, the amount of addition of Ni and Si is small, and the amount of precipitates is small after aging treatment. Therefore, during the subsequent rolling, the amount of accumulated dislocations is small (work hardening is small), and continuous recrystallization occurs during low-temperature annealing. The tensile strength was low. In addition, despite the low strength, BadWay bending workability was not particularly improved.

[Comparative Example 2]
A copper alloy containing 4.42% by mass of Ni and 1.08% by mass of Si, with the balance being Cu and inevitable impurities was melted, and hot treatment was performed in the same manner as in Example 1. In this comparative example, since the addition amounts of Ni and Si were too large, severe cracks occurred during hot rolling, and subsequent production was interrupted.

[Comparative Examples 3 to 7]
In the comparative example 5, except that the aging treatment was performed at 625 ° C. for 6 hours in the comparative example 4 except that the aging treatment was not performed in the comparative example 3 except that the copper alloys having the same components as in the example 2 were melted. In Comparative Example 6, except that cold rolling was performed at a rolling rate of 89.3% after performing cold aging to a thickness of 1.4 mm after rolling and then performing a aging treatment, in Comparative Example 6 except that the low-temperature annealing time was 1 minute. In Example 7, a copper alloy sheet was obtained in the same manner as in Example 2 except that low temperature annealing was performed at 450 ° C. for 6 hours. In addition, when the electrical conductivity of the plate material after the aging treatment (after hot rolling in Comparative Example 3) was measured by the same method as in Examples 1 to 10, 28.7% IACS (Comparative Example 3) and 50.8 respectively. % IACS (Comparative Example 4), 49.5% IACS (Comparative Example 5), 49.0% IACS (Comparative Examples 6 and 7), and after the aging treatment (after hot rolling in Comparative Example 3), When the Vickers hardness of the plate surface (rolled surface) was determined by the same method as in Examples 1 to 10, Hv141 (Comparative Example 3), Hv124 (Comparative Example 4), Hv202 (Comparative Example 5), and Hv195 (Comparative), respectively. Example 6 and 7). Further, when the Vickers hardness of the plate surface (rolled surface) of the plate material after cold rolling was determined by the same method as in Examples 1 to 10, Hv212 (Comparative Example 3), Hv202 (Comparative Example 4), and Hv228, respectively. (Comparative Example 5) and Hv243 (Comparative Examples 6 and 7).

  Next, samples were collected from the copper alloy sheet materials obtained in these comparative examples, and the average crystal grain size, conductivity, tensile strength, hardness, elongation at break, bending work were performed in the same manner as in Examples 1-10. The sex was examined. As a result, the average crystal grain size of the copper alloy sheet was 8.4 μm (Comparative Example 3), 6.6 μm (Comparative Example 4), 5.2 μm (Comparative Example 5), 20 μm (Comparative Example 6), respectively. The conductivity is 50.9% IACS (Comparative Example 3), 62.4% IACS (Comparative Example 4), 54.4% IACS (Comparative Example 5), and 46.8, respectively. % IACS (Comparative Example 6) and 57.9% IACS (Comparative Example 7). The tensile strengths are 632 MPa (Comparative Example 3), 592 MPa (Comparative Example 4), 692 MPa (Comparative Example 5), 766 MPa (Comparative Example 6), and 608 MPa (Comparative Example 7), respectively. 8.9% (Comparative Example 3), 9.6% (Comparative Example 4), 7.6% (Comparative Example 5), 2.5% (Comparative Example 6), 8.6% (Comparative Example 7) The Vickers hardness was Hv195 (Comparative Example 3), Hv184 (Comparative Example 4), Hv210 (Comparative Example 5), Hv240 (Comparative Example 6), and Hv190 (Comparative Example 7), respectively. Further, the R / t values of Good Way bending with TD as the bending axis and Bad Way bending with LD as the bending axis are 0.0 and 1.7 (Comparative Example 3), 0.0 and 1.0 (Comparison), respectively. Example 4), 0.0 and 2.7 (Comparative Example 5), 1.0 and 6.0 (Comparative Example 6), 0.0 and 1.0 (Comparative Example 7).

  Comparative Examples 3 to 7 are examples in which characteristics were deteriorated because a copper alloy having the same components as in Example 2 was melted and the process conditions after hot rolling were inappropriate. In Comparative Example 3, since the aging treatment after hot rolling was not performed, precipitates were reduced (conductivity 28.7% IACS after hot rolling, hardness Hv141). Therefore, dislocations were generated during cold rolling. The amount of accumulation is small, the Vickers hardness after cold rolling is low compared to Example 2, the continuous recrystallization cannot be sufficiently generated during low temperature annealing, and the tensile strength is low compared to Example 2. Despite the decrease, BadWay bending workability was not good. In Comparative Example 4, the aging treatment temperature was too high and the precipitates became coarse, so that the amount of dislocation accumulated during the subsequent cold rolling was small and the tensile strength was low. In Comparative Example 5, after hot rolling, the steel sheet was cold-rolled to a thickness of 1.4 mm and then subjected to an aging treatment. The rolling rate of the subsequent cold rolling was 89.3%, the amount of dislocations was small, and Bad Way bending Workability was not good. In Comparative Example 6, since low-temperature annealing was performed for a short time in the same manner as normal low-temperature annealing, almost no continuous recrystallization could be generated, and although the tensile strength was high, BadWay bending workability was significantly reduced. did. In Comparative Example 7, since the temperature of the low-temperature annealing was high and the time was long, discontinuous recrystallization occurred and the tensile strength decreased.

[Comparative Examples 8-12]
After melting copper alloys having the same components as in Example 2 and obtaining slabs by the same method as in Examples 1 to 10, each slab was heated to 950 ° C. and held for 1 hour, 950 A steel sheet having a thickness of 10 mm is obtained by performing hot rolling while lowering the temperature from ℃ to 650 ℃, then rapidly cooled, and then cold-cooled to a thickness of 0.2 mm by a normal manufacturing method, that is, after hot rolling. After rolling, forming a solution at 750 ° C. for 1 minute and cooling with water, aging treatment, cold rolling and low temperature annealing were performed to produce a copper alloy sheet. The aging treatment is performed at 450 ° C. for 3 hours (Comparative Example 8), 450 ° C. for 6 hours (Comparative Example 9), and 450 ° C. for 20 hours (Comparative Examples 10 to 12). % (Comparative Examples 8 to 10), rolling rate of 40.0% (Comparative Examples 11 and 12), and low temperature annealing was performed at 425 ° C. for 1 minute (Comparative Examples 8 to 11) and 425 ° C. for 3 hours (Comparative Example) 12) went.

  In addition, when the electrical conductivity of the board | plate material after an aging treatment was measured by the method similar to Examples 1-10, it was 42.6% IACS (comparative example 8), 44.7% IACS (comparative example 9), and 50.%, respectively. 6% IACS (Comparative Examples 10 to 12), and the Vickers hardness of the plate surface (rolled surface) of the plate after the aging treatment was determined by the same method as in Examples 1 to 10, and Hv208 (Comparative Example 8). ), Hv220 (Comparative Example 9), and Hv182 (Comparative Examples 10-12). Further, when the Vickers hardness of the plate surface (rolled surface) of the plate material after cold rolling was determined by the same method as in Examples 1 to 10, Hv220 (Comparative Example 8), Hv238 (Comparative Example 9), and Hv206, respectively. (Comparative Example 10) and Hv237 (Comparative Examples 11 and 12).

  Next, samples were collected from the copper alloy sheet materials obtained in these comparative examples, and the average crystal grain size, conductivity, tensile strength, hardness, elongation at break, bending work were performed in the same manner as in Examples 1-10. The sex was examined. As a result, the average crystal grain size of the copper alloy sheet was 8.5 μm, and the conductivity was 41.9% IACS (Comparative Example 8), 43.8% IACS (Comparative Example 9), and 49. They were 8% IACS (Comparative Example 10), 49.2% IACS (Comparative Example 11), and 51.4% IACS (Comparative Example 12). The tensile strengths are 720 MPa (Comparative Example 8), 754 MPa (Comparative Example 9), 674 MPa (Comparative Example 10), 746 MPa (Comparative Example 11), and 690 MPa (Comparative Example 12), respectively. 8.4% (Comparative Example 8), 6.6% (Comparative Example 9), 5.4% (Comparative Example 10), 3.6% (Comparative Example 11), 7.2% (Comparative Example 12) The Vickers hardness was Hv222 (Comparative Example 8), Hv240 (Comparative Example 9), Hv208 (Comparative Example 10), Hv239 (Comparative Example 11), and Hv215 (Comparative Example 12), respectively. Further, the R / t values of Good Way bending with TD as the bending axis and Bad Way bending with LD as the bending axis are 1.7 and 1.0 (Comparative Example 8), 1.7 and 2.0 (Comparison), respectively. Examples 9), 1.0 and 2.5 (Comparative Example 10), 2.0 and 6.0 (Comparative Example 11), 1.7 and 4.0 (Comparative Example 12).

  In Comparative Examples 8 and 9, the aging treatment was performed for a relatively short time, and the tensile strength and the bending workability were good, but the electrical conductivity was low. In Comparative Example 10, the aging treatment time was made longer than Comparative Examples 8 and 9 in order to improve the electrical conductivity, but the tensile strength and BadWay bending workability were lowered. In Comparative Example 11, in order to maintain the electrical conductivity of Comparative Example 10 and increase the tensile strength, the rolling rate of cold rolling after aging treatment was increased, and the tensile strength strength was improved. Bending workability was significantly reduced. In Comparative Example 12, low-temperature annealing was performed at 425 ° C. for 3 hours in the same manner as in Example 2. However, since the cold rolling rate before low-temperature annealing was as low as 40%, continuous recrystallization could not be generated. Therefore, BadWay bending workability could not be recovered.

  Table 1 shows the compositions of the copper alloys used in the copper alloy sheet materials of Examples 1 to 15 and Comparative Examples 1 to 12, and Table 2 shows the manufacturing conditions and the conductivity and Vickers hardness of the sheet material being manufactured. Table 3 shows the characteristics of the produced copper alloy sheet.

[Comparative Examples 13 to 16]
As Comparative Examples 13 to 16, commercially available copper alloy process materials C7025-TM02, C7025-TM03, C7025-TM04, and C7025-TR02 having a thickness of 0.15 mm each having substantially the same components as in Example 2 were prepared. Analysis and characterization were performed. In addition, TM process material is generally a plate material manufactured by performing cold rolling, solution treatment and aging treatment after hot rolling, and has relatively good bending workability and relatively high demand for bending workability. It is used as a plate material for current-carrying parts of electrical and electronic equipment such as connectors. On the other hand, the TR process material is generally a plate material manufactured by repeating cold rolling and aging treatment without performing a solution treatment after hot rolling, and has a relatively high conductivity, but a relatively high bending workability. Unfortunately, it is used as a plate material for current-carrying parts of electrical and electronic equipment such as lead frames that have a relatively low demand for bending workability.

  As a result, these plate materials each contain 2.52% by mass of Ni, 0.52% by mass of Si and 0.16% by mass of Mg, with the balance being Cu and inevitable impurities (Comparative Example 13). A copper alloy containing 2.49% by mass of Ni, 0.50% by mass of Si and 0.14% by mass of Mg, the balance being Cu and inevitable impurities (Comparative Example 14), 2.48% by mass of Ni And 0.49% by mass of Si and 0.15% by mass of Mg, with the balance being Cu and inevitable impurities (Comparative Example 15), 2.53% by mass of Ni and 0.53% by mass of Si And 0.15% by mass of Mg, with the balance being a copper alloy plate (Comparative Example 16) made of Cu and inevitable impurities. In addition, the average crystal grain sizes of the plate materials are 8.4 μm (Comparative Example 13), 8.6 μm (Comparative Example 14), 9.0 μm (Comparative Example 15), and 6.2 μm (Comparative Example 16), respectively. The rates were 45.2% IACS (Comparative Example 13), 43.8% IACS (Comparative Example 14), 42.2% IACS (Comparative Example 15), and 51.3% IACS (Comparative Example 16), respectively. . The tensile strengths were 724 MPa (Comparative Example 13), 742 MPa (Comparative Example 14), 815 MPa (Comparative Example 15), and 655 MPa (Comparative Example 16), respectively, and the elongation at break was 9.4% (Comparative Example). 13), 8.6% (Comparative Example 14), 2.8% (Comparative Example 15), 4.3% (Comparative Example 16), and the Vickers hardness is Hv218 (Comparative Example 13) and Hv232 (respectively). Comparative Example 14), Hv249 (Comparative Example 15), and Hv203 (Comparative Example 16). Further, R / t values of Good Way bending with TD as the bending axis and Bad Way bending with LD as the bending axis are 1.5 and 1.0 (Comparative Example 13), 1.5 and 1.5 (Comparison, respectively). Examples 14), 2.0 and 6.0 (Comparative Example 15), 1.5 and 4.0 (Comparative Example 16).

  Thus, the commercially available C7025-TM process materials of Comparative Examples 13 to 15 have an electrical conductivity of about 45% IACS in order to maintain a tensile strength of 700 MPa or more. On the other hand, the commercially available C7025-TR process material of Comparative Example 16 has a conductivity exceeding 50% IACS, but the tensile strength is low and the bending workability is remarkably deteriorated.

  The compositions of the plate materials of Comparative Examples 13 to 16 are shown in Table 4, and the property evaluation results are shown in Table 5.

Claims (15)

Obtained by melting and casting a raw material of a copper alloy containing 1.0 to 4.0% by mass of Ni and 0.3 to 1.0% by mass of Si, with the balance consisting of Cu and inevitable impurities. The obtained slab was hot-rolled or homogenized, then subjected to aging treatment at 450 to 600 ° C. for 1 to 20 hours, and then cold rolling at a rolling rate of 90% or more, and then at 300 to 430 ° C. A method for producing a copper alloy sheet, comprising performing low-temperature annealing for 1 to 48 hours. 2. The method for producing a copper alloy sheet according to claim 1, wherein the aging treatment is performed so that the electrical conductivity is 40% IACS or more and the Vickers hardness is Hv 150 or more after the aging treatment. The method for producing a copper alloy sheet according to claim 1 or 2, wherein the composition of the raw material of the copper alloy further contains 0.01 to 0.3% by mass of Mg. The composition of the raw material of the copper alloy is one or more elements selected from the group consisting of Sn, Zn, Co, Cr, P, B, Al, Fe, Zr, Ti, and Mn in a range of 3 mass% or less in total. It further contains, The manufacturing method of the copper alloy board | plate material in any one of the Claims 1 thru | or 3 characterized by the above-mentioned. It has a composition comprising 1.0 to 4.0% by mass of Ni and 0.3 to 1.0% by mass of Si, with the balance being Cu and inevitable impurities. A copper alloy sheet having a fine grain structure with an average grain size of 1 μm or less as a boundary. The minimum bend radius R and the thickness t of the copper alloy sheet are such that the conductivity is 50% IACS or more, the tensile strength is 650 MPa or more, and a 90 ° W bend test is performed in accordance with JIS H3110, and cracks do not occur. Ratio R / t is 2.0 or less, The copper alloy board | plate material of Claim 5 characterized by the above-mentioned. The copper alloy sheet according to claim 6, wherein the conductivity is 55% IACS or more. The copper alloy sheet according to claim 6, wherein the conductivity is 60% IACS or more. The copper alloy sheet according to any one of claims 6 to 8, wherein the tensile strength is 700 MPa or more. The copper alloy sheet according to claim 6 or 7, wherein the tensile strength is 750 MPa or more. The copper alloy sheet according to claim 6 or 7, wherein the tensile strength is 800 MPa or more. The copper alloy sheet according to claim 6, wherein the R / t is 1.0 or less. 9. The copper alloy sheet according to claim 6, wherein the R / t is 0.5 or less. The composition of the said copper alloy board | plate material further contains 0.01-0.3 mass% Mg, The copper alloy board | plate material in any one of the Claims 5 thru | or 13 characterized by the above-mentioned. The composition of the copper alloy sheet further includes at least one element selected from the group consisting of Sn, Zn, Co, Cr, P, B, Al, Fe, Zr, Ti, and Mn in a range of 3% by mass or less in total. The copper alloy sheet material according to claim 5, wherein the copper alloy sheet material is included.