JP6366298B2 - High-strength copper alloy sheet material and manufacturing method thereof - Google Patents

Description

本発明は、コネクタ、リードフレーム、リレー、スイッチなどの電気・電子部品の小型化に適したＣｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金の薄板材（箔）において、導電性を良好に維持しながら高い強度と良好な曲げ加工性を付与したもの、およびその製造方法に関する。ここで、Ｃｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金の［Ｎｉ，Ｃｏ］とは、Ｎｉ、Ｃｏの１種または２種を含有することを意味する。すなわち、対象となる合金系を個別に表すと、Ｃｕ−Ｎｉ−Ｓｉ系銅合金、Ｃｕ−Ｃｏ−Ｓｉ系銅合金、Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金である。   The present invention maintains good conductivity in Cu- [Ni, Co] -Si-based copper alloy thin sheet (foil) suitable for miniaturization of electrical and electronic parts such as connectors, lead frames, relays, and switches. The present invention relates to a material having high strength and good bending workability, and a method for producing the same. Here, [Ni, Co] of the Cu— [Ni, Co] —Si based copper alloy means containing one or two of Ni and Co. In other words, the target alloy systems are individually represented as a Cu—Ni—Si copper alloy, a Cu—Co—Si copper alloy, and a Cu—Ni—Co—Si copper alloy.

コネクタ、リードフレーム、リレー、スイッチなどの通電部品として電気・電子部品に使用される材料には、通電によるジュール熱の発生を抑制するために良好な「導電性」が要求されるとともに、電気・電子機器の組立時や作動時に付与される応力に耐え得る高い「強度」が要求される。また、コネクタなどの電気・電子部品は、一般にプレス打ち抜き後に曲げ加工により成形されることから、優れた「曲げ加工性」も要求される。   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 flow. A high “strength” that can withstand the stress applied during assembly and operation of electronic devices is required. In addition, since electrical / electronic parts such as connectors are generally formed by bending after press punching, excellent “bending workability” is also required.

近年、コネクタなどの電気・電子部品は小型化および軽量化が進む傾向にあり、それに伴って、素材である銅合金の板材には薄肉化が要求される。特に昨今では、板厚５５μｍ以下といった薄板材（箔）のニーズが高まっている。そのため、素材に要求される強度レベル、導電性レベルは一層厳しくなっている。具体的には板厚６０μｍ以下の薄板において０.２％耐力９００ＭＰａ以上の強度レベルと導電率３５％ＩＡＣＳ以上の導電性レベルを併せ持つ素材特性が望まれる。曲げ加工性については、曲げ軸を圧延方向とするＢＷ（Ｂａｄ Ｗａｙ）の９０°Ｗ曲げ加工試験において、ＭＢＲ／ｔ≦１.０をクリアすることが望まれる。ここで、ＭＢＲは最小曲げ半径（Ｍｉｎｉｍｕｍ Ｂｅｎｄ Ｒａｄｉｕｓ）、ｔは板厚を意味する。   In recent years, electrical and electronic parts such as connectors tend to be smaller and lighter, and accordingly, copper alloy plate materials are required to be thin. Particularly in recent years, there is an increasing need for thin plate materials (foil) having a plate thickness of 55 μm or less. For this reason, the strength level and conductivity level required for the material are becoming stricter. Specifically, a material characteristic having both a strength level of 0.2% proof stress 900 MPa or more and a conductivity level of conductivity 35% IACS or more in a thin plate having a thickness of 60 μm or less is desired. Regarding the bending workability, it is desirable to satisfy MBR / t ≦ 1.0 in a 90 ° W bending work test of BW (Bad Way) with the bending axis as the rolling direction. Here, MBR is the minimum bend radius, and t is the plate thickness.

強度と導電性の特性バランスに比較的優れた銅合金材料として、Ｃｕ−Ｎｉ−Ｓｉ系銅合金（いわゆるコルソン合金）がある。また、これにＣｏを加えて特性を改善したＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金も実用化されている。しかし、これらの合金系において薄肉化を図る場合、強度と曲げ加工性を高いレベルで両立させることは容易でない。例えば、下記特許文献１には厚さ０.０３５ｍｍのＣｕ−Ｎｉ−Ｓｉ系銅合金箔が示されているが、その引張強さは８５０Ｎ／ｍｍ²以下であり、曲げ加工性は考慮されていない。特許文献２にも厚さ０.０３５ｍｍのＣｕ−Ｎｉ−Ｓｉ系銅合金箔が示されているが、その引張強さは８６０Ｎ／ｍｍ²以下であり、曲げ加工性は考慮されていない。特許文献３には厚さ０.０３〜０.５ｍｍのＣｕ−Ｎｉ−Ｓｉ系銅合金板材が想定され、厚さ０.０８ｍｍの板材について特性が調べられているが、その耐力レベルは８００ＭＰａを下回っている。特許文献４には厚さ０.０３１ｍｍのＣｕ−Ｎｉ−Ｓｉ系銅合金箔が示されているが、その０.２％耐力は７４１ＭＰａである。 As a copper alloy material having a relatively excellent balance between strength and conductivity, there is a Cu—Ni—Si based copper alloy (so-called Corson alloy). In addition, a Cu—Ni—Co—Si based copper alloy whose characteristics are improved by adding Co to this has been put into practical use. However, when thinning these alloy systems, it is not easy to achieve both strength and bending workability at a high level. For example, Patent Document 1 below shows a Cu-Ni-Si-based copper alloy foil having a thickness of 0.035 mm, but its tensile strength is 850 N / mm ² or less, and bending workability is taken into consideration. Absent. Patent Document 2 also discloses a Cu-Ni-Si-based copper alloy foil having a thickness of 0.035 mm, but its tensile strength is 860 N / mm ² or less, and bending workability is not considered. Patent Document 3 assumes a Cu-Ni-Si-based copper alloy sheet having a thickness of 0.03 to 0.5 mm, and the characteristics of the sheet having a thickness of 0.08 mm have been investigated. The proof stress level is 800 MPa. It is below. Patent Document 4 discloses a Cu-Ni-Si copper alloy foil having a thickness of 0.031 mm, and its 0.2% proof stress is 741 MPa.

特開２００２−９７５３４号公報JP 2002-97534 A 特開２００３−１３１５８号公報JP 2003-13158 A 特開２０１３−２０４０７９号公報JP 2013-204079 A 特開２０１３−１６３８５３号公報JP 2013-163853 A

Ｃｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金では析出強化を利用するため、時効処理前に溶体化処理の工程が必要となる。薄板（箔）を製造する場合にはできるだけ板厚を減じた状態で溶体化処理を施した方が、後工程での負荷軽減の観点から好ましい。しかし、板厚が薄いと、焼鈍軟化した状態で製造ラインに通す過程で板に「折れ」や「しわ」が生じやすい。そのような欠陥の発生は、後工程での破断トラブルや製品品質低下の要因となる。そのため、一般的な大量生産ラインを利用して溶体化処理を行う際には一定以上の板厚（製造ラインにもよるが例えば０.１ｍｍ以上）を確保しておくことが必要であり、最終的に薄板（箔）を得る場合には溶体化処理後の圧延率を高く設定せざるを得ないのが現状である。   Since the Cu— [Ni, Co] —Si based copper alloy uses precipitation strengthening, a solution treatment step is required before the aging treatment. In the case of producing a thin plate (foil), it is preferable from the viewpoint of reducing the load in the subsequent step that the solution treatment is performed with the plate thickness reduced as much as possible. However, if the plate thickness is thin, the plate is likely to “fold” or “wrinkle” in the process of passing through the production line in the annealed and softened state. The occurrence of such a defect causes a breakage trouble in a subsequent process and a product quality deterioration. Therefore, when performing a solution treatment using a general mass production line, it is necessary to ensure a certain thickness (for example, 0.1 mm or more depending on the production line). In particular, when a thin plate (foil) is to be obtained, the rolling rate after the solution treatment must be set high.

｛２００｝結晶面が板面にほぼ平行である結晶粒の存在割合が多い純銅型再結晶集合組織（以下、単に「｛２００｝配向」ということがある）は曲げ加工性に有利な集合組織である。しかし、銅合金板材の一般的な製造工程において、｛２００｝配向の再結晶集合組織を得ることは容易でない。また、冷間圧延率の増大に伴い、｛２２０｝結晶面が板面にほぼ平行である結晶粒の存在割合が多い集合組織（以下、単に「｛２２０｝配向」ということがある）が発達していく。｛２２０｝配向は曲げ加工性に不利な集合組織である。   A pure copper-type recrystallized texture (hereinafter sometimes simply referred to as “{200} orientation”) having a large proportion of crystal grains whose {200} crystal plane is substantially parallel to the plate surface is a texture advantageous to bending workability. It is. However, it is not easy to obtain a recrystallized texture of {200} orientation in a general manufacturing process of a copper alloy sheet. Further, with the increase in the cold rolling rate, a texture (hereinafter, simply referred to as “{220} orientation”) is developed in which there is a large proportion of crystal grains whose {220} crystal plane is substantially parallel to the plate surface. I will do it. The {220} orientation is a texture that is disadvantageous for bending workability.

通常の大量生産ラインで溶体化処理を行う場合は上述の板厚確保の制約により、板厚約５０μｍ程度以下の薄板（箔）を得るためには仕上冷間圧延率を高く設定せざるを得ない。従って、最終的に｛２２０｝配向が優勢となり、曲げ加工性が犠牲となってしまう。一方、薄ゲージに対応した焼鈍設備を利用して慎重に溶体化処理を施せば、仕上冷間圧延率を軽減することは可能である。しかし、薄ゲージでの溶体化処理や時効処理は、板厚が薄い分だけ処理すべき条材の総延長が長くなること、および破断・折れトラブル回避のためにライン速度を容易に上げられないことから、生産性の低下を招く。   When solution treatment is performed on a normal mass production line, due to the above-mentioned restrictions on securing the sheet thickness, it is necessary to set a high finish cold rolling rate in order to obtain a thin sheet (foil) with a sheet thickness of about 50 μm or less. Absent. Therefore, the {220} orientation finally becomes dominant, and bending workability is sacrificed. On the other hand, if the solution treatment is carefully performed using an annealing facility compatible with a thin gauge, it is possible to reduce the finish cold rolling rate. However, the solution treatment and aging treatment with a thin gauge does not allow the line speed to be easily increased in order to increase the total length of the strip material to be processed by the thin plate thickness and to avoid breakage and breakage troubles. As a result, productivity is reduced.

銅合金板材では強度と曲げ加工性はトレードオフの関係にあるが、薄板（箔）においてそれらの特性を両立させることは更に難しい。本発明は、曲げ加工性、導電性を良好に維持しながら高強度化を図ったＣｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金の薄板（箔）を提供することを目的とする。   In a copper alloy sheet, strength and bending workability are in a trade-off relationship, but it is more difficult to achieve both properties in a thin sheet (foil). An object of the present invention is to provide a thin plate (foil) of a Cu— [Ni, Co] —Si based copper alloy that achieves high strength while maintaining good bending workability and conductivity.

上記目的は、質量％で、ＮｉとＣｏの合計：２.５０〜５.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.１０％、Ｃｒ：０〜０.１０％、Ｍｇ：０〜０.１０％、Ｍｎ：０〜０.１０％、Ｔｉ：０〜０.３０％、Ｖ：０〜０.２０％、Ｚｒ：０〜０.１５％、Ｓｎ：０〜０.１０％、Ｚｎ：０〜０.１５％、Ａｌ：０〜０.２０％、Ｂ：０〜０.０２％、Ｐ：０〜０.１０％、Ａｇ：０〜０.１０％、Ｂｅ：０〜０.１５％、ＲＥＭ（希土類元素）：０〜０.１０％であり、残部Ｃｕおよび不可避的不純物からなり、かつ下記（１）式を満たす化学組成を有し、母相中に存在する第二相粒子のうち、粒子径３ｎｍ以上１０ｎｍ以下の「超微細第二相粒子」の個数密度が１.０×１０⁹個／ｍｍ²以上であり、下記（２）式および（３）式のＸ線回折強度比を満たし、板厚が２０〜６０μｍである高強度銅合金薄板材によって達成される。
３.５≦（Ｎｉ＋Ｃｏ）／Ｓｉ≦５.０ …（１）
ここで、（１）式の元素記号の箇所には当該元素の含有量値（質量％）が代入される。
Ｉ｛２００｝／（Ｉ｛１１１｝＋Ｉ｛２２０｝＋Ｉ｛３１１｝）≧０.５０ …（２）
Ｉ｛２２０｝／（Ｉ｛１１１｝＋Ｉ｛２００｝＋Ｉ｛３１１｝）≦０.７５ …（３）
ここで、Ｉ｛ｈｋｌ｝は当該銅合金薄板材板面における｛ｈｋｌ｝結晶面のＸ線回折ピークの積分強度である。 The purpose is mass%, and the total of Ni and Co: 2.50 to 5.00%, Si: 0.50 to 1.50%, Fe: 0 to 0.10%, Cr: 0 to 0.10 %, Mg: 0 to 0.10%, Mn: 0 to 0.10%, Ti: 0 to 0.30%, V: 0 to 0.20%, Zr: 0 to 0.15%, Sn: 0 ~ 0.10%, Zn: 0 ~ 0.15%, Al: 0 ~ 0.20%, B: 0 ~ 0.02%, P: 0 ~ 0.10%, Ag: 0 ~ 0.10% , Be: 0 to 0.15%, REM (rare earth element): 0 to 0.10%, consisting of the balance Cu and unavoidable impurities, and having a chemical composition satisfying the following formula (1), Among the second phase particles present therein, the number density of “ultrafine second phase particles” having a particle diameter of 3 nm or more and 10 nm or less is 1.0 × 10 ⁹ particles / mm ² or more, and the following formula (2) and Satisfies the X-ray diffraction intensity ratio of equation (3) , Plate thickness is achieved by a high strength copper alloy sheet material which is a 20 to 60 [mu] m.
3.5 ≦ (Ni + Co) /Si≦5.0 (1)
Here, the content value (% by mass) of the element is substituted for the element symbol in the formula (1).
I {200} / (I {111} + I {220} + I {311}) ≧ 0.50 (2)
I {220} / (I {111} + I {200} + I {311}) ≦ 0.75 (3)
Here, I {hkl} is the integrated intensity of the X-ray diffraction peak of the {hkl} crystal plane on the copper alloy sheet.

その高強度銅合金薄板材は、圧延方向の０.２％耐力が９００ＭＰａ以上、導電率が３５％ＩＡＣＳ以上という特性を具備する。金属組織中には、粒子径５００ｎｍ以上２０００ｎｍ以下の「粗大第二相粒子」が観察され、その個数密度は例えば１.０×１０⁴個／ｍｍ²以上である。なお、本発明においてＹ（イットリウム）はＲＥＭ（希土類元素）であるとして扱う。 The high-strength copper alloy sheet has the characteristics that the 0.2% proof stress in the rolling direction is 900 MPa or more and the conductivity is 35% IACS or more. In the metal structure, “coarse second phase particles” having a particle diameter of 500 nm or more and 2000 nm or less are observed, and the number density thereof is, for example, 1.0 × 10 ⁴ particles / mm ² or more. In the present invention, Y (yttrium) is treated as REM (rare earth element).

上記高強度銅合金薄板材の製造方法として、上記化学組成を有する銅合金鋳片に対して、圧延終了温度６５０℃以上、６５０℃から３００℃までの平均冷却速度が１０℃／ｓｅｃ以上の条件で熱間圧延を施す工程、
８００℃から９５０℃までの平均昇温速度を５０℃／ｓｅｃ以上とし、９５０〜１０２０℃の範囲で５〜３００ｓｅｃ保持して第二相粒子を固溶させ、９５０℃から６５０℃までの平均冷却速度を１０〜３０℃／ｓｅｃとする条件で溶体化処理を施す工程、
前記溶体化処理後の材料または前記溶体化処理後に圧延率５０％以下の冷間圧延を施した材料に対して、時効処理後の圧延方向引張強さＴＳ(age)（ＭＰａ）および導電率ＥＣ(age)（％ＩＡＣＳ）がそれぞれ下記（４）式および（５）式を満たす条件で時効処理を施す工程、
前記時効処理後の組織状態を有する材料に対して、圧延率２０〜９０％の範囲で仕上冷間圧延を施して板厚２０〜６０μｍとする工程、
を有する高強度銅合金薄板材の製造方法が提供される。
０.９０≦ＴＳ(age)／ＴＳ(max)≦０.９７ …（４）
１.０５≦ＥＣ(age)／ＥＣ(tsmax)≦１.２０ …（５）
ここで、ＴＳ(max)は、前記溶体化処理後の当該材料に対して、３５０℃から６００℃までの１０℃刻みの各温度で６ｈ保持する時効処理を施したときに得られる圧延方向最大引張強さ（ＭＰａ）であり、ＥＣ(tsmax)は、前記ＴＳ(max)が得られた試料における導電率（％ＩＡＣＳ）である。 As a method for producing the high-strength copper alloy sheet material, a condition where the rolling cooling temperature is 650 ° C. or higher and the average cooling rate from 650 ° C. to 300 ° C. is 10 ° C./sec or more with respect to the copper alloy slab having the chemical composition. The process of hot rolling in
The average temperature increase rate from 800 ° C. to 950 ° C. is set to 50 ° C./sec or more, and the second phase particles are dissolved in the range of 950 to 1020 ° C. for 5 to 300 seconds, and the average cooling from 950 ° C. to 650 ° C. A step of applying a solution treatment under conditions where the speed is 10 to 30 ° C./sec
With respect to the material after the solution treatment or the material subjected to the cold rolling with a rolling rate of 50% or less after the solution treatment, the tensile strength TS (age) (MPa) in the rolling direction after the aging treatment and the conductivity EC (age) (% IACS) is a process of performing an aging treatment under conditions satisfying the following formulas (4) and (5), respectively:
A step of subjecting the material having a textured state after the aging treatment to finish cold rolling in a range of a rolling rate of 20 to 90% to a plate thickness of 20 to 60 μm;
The manufacturing method of the high intensity | strength copper alloy sheet material which has this is provided.
0.90 ≦ TS (age) / TS (max) ≦ 0.97 (4)
1.05 ≦ EC (age) / EC (tsmax) ≦ 1.20 (5)
Here, TS (max) is the maximum in the rolling direction obtained when the material after the solution treatment is subjected to an aging treatment for 6 hours at each temperature of 10 ° C. from 350 ° C. to 600 ° C. It is the tensile strength (MPa), and EC (tsmax) is the electrical conductivity (% IACS) in the sample from which the TS (max) was obtained.

前記仕上冷間圧延後には、加熱温度１５０〜５５０℃の低温焼鈍を施すことができる。
また本発明では、上記の銅合金薄板材を素材に使用した通電部品が提供される。 After the finish cold rolling, low temperature annealing at a heating temperature of 150 to 550 ° C. can be performed.
Moreover, in this invention, the electricity supply component which uses said copper alloy thin plate material for a raw material is provided.

本発明によれば、曲げ加工性、導電性を良好に維持しながら高強度化を図ったＣｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金の薄板（箔）が提供可能となった。その特性は、０.２％耐力９００ＭＰａ以上、導電率３５％ＩＡＣＳ以上というものであり、当該合金系の板厚６０μｍ以下という薄板材において、従来工業的量産過程で実現することが困難であった特性を具備する。従って本発明は、コネクタ、リードフレーム、リレー、スイッチなどの通電部品の小型化に寄与するものである。   ADVANTAGE OF THE INVENTION According to this invention, it became possible to provide the thin plate (foil) of Cu- [Ni, Co] -Si type copper alloy which aimed at high intensity | strength, maintaining bending workability and electroconductivity favorably. Its characteristics are 0.2% proof stress 900MPa or more, conductivity 35% IACS or more, and it has been difficult to realize in the conventional industrial mass production process in the thin plate material of the alloy system having a plate thickness of 60μm or less. It has characteristics. Therefore, the present invention contributes to miniaturization of current-carrying parts such as connectors, lead frames, relays, and switches.

発明者らは、研究の結果、以下のような知見を得た。
（ａ）Ｃｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金において、粒子径５００ｎｍ以上２０００ｎｍ以下の「粗大第二相粒子」が十分に存在する組織状態の焼鈍材に冷間圧延を施したとき、｛２２０｝配向の圧延集合組織の発達を抑制することができる。
（ｂ）その粗大第二相粒子は、溶体化処理の冷却過程を徐冷として粗大第二相粒子の核を生成させた上で、時効処理をやや過時効側で実施することにより、多量に生成させることができる。
（ｃ）溶体化処理での昇温速度を速くすることにより再結晶集合組織の｛２００｝配向が向上し、上記の圧延集合組織の抑制効果と相俟って冷間圧延材の曲げ加工性向上に有利となる。
（ｄ）過時効側に振れすぎないように時効処理条件を厳しく管理することにより、強度に寄与する粒子径３ｎｍ以上１０ｎｍ以下の「超微細第二相粒子」の数を十分に維持することができ、上記の圧延集合組織の抑制効果を活用して仕上冷間圧延を十分に確保することによる加工硬化の増大効果と合わせて、薄板材の高強度化を図ることができる。
本発明はこのような知見に基づいて完成したものである。 The inventors have obtained the following findings as a result of the research.
(A) In a Cu- [Ni, Co] -Si-based copper alloy, when cold rolling was performed on an annealed material in a structure state in which “coarse second phase particles” having a particle diameter of 500 nm to 2000 nm are sufficiently present, Development of a {220} -oriented rolling texture can be suppressed.
(B) The coarse second-phase particles can be produced in a large amount by gradually cooling the cooling process of the solution treatment to generate nuclei of coarse second-phase particles and then carrying out the aging treatment on the slightly overaging side. Can be generated.
(C) The {200} orientation of the recrystallized texture is improved by increasing the heating rate in the solution treatment, and the bending workability of the cold-rolled material is combined with the effect of suppressing the above-mentioned rolled texture. It is advantageous for improvement.
(D) The number of “ultrafine second phase particles” having a particle diameter of 3 nm or more and 10 nm or less contributing to the strength can be sufficiently maintained by strictly managing the aging treatment conditions so as not to shake too much on the overaging side. In addition, it is possible to increase the strength of the thin plate material together with the effect of increasing the work hardening by sufficiently securing the finish cold rolling by utilizing the effect of suppressing the rolling texture.
The present invention has been completed based on such findings.

〔第二相粒子〕
Ｃｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系合金は、ｆｃｃ結晶からなる母相（マトリクス）の中に第二相粒子が存在する金属組織を呈する。第二相粒子は鋳造工程の凝固時に生成する晶出物およびその後の製造工程で生成する析出物であり、当該合金の場合、主としてＣｏ−Ｓｉ系金属間化合物相とＮｉ−Ｓｉ系金属間化合物相で構成される。この第二相粒子は粒子径によって異別の作用を呈する。 [Second phase particles]
The Cu— [Ni, Co] —Si alloy exhibits a metal structure in which second phase particles are present in a matrix (matrix) made of fcc crystals. The second phase particles are a crystallized product generated during solidification in the casting process and a precipitate generated in the subsequent manufacturing process. In the case of the alloy, the Co-Si based intermetallic compound phase and the Ni-Si based intermetallic compound are mainly used. Composed of phases. The second phase particles exhibit different effects depending on the particle diameter.

（i）超微細第二相粒子
本明細書でいう「超微細第二相粒子」は粒子径３ｎｍ以上１０ｎｍ以下であり、溶体化処理後の時効処理で生成し、強度向上に寄与する。種々検討の結果、超微細第二相粒子の個数密度は１.０×１０⁹個／ｍｍ²以上を確保する必要がある。それより少ないと仕上冷間圧延での圧延率を高くしても、板厚６０μｍ以下の薄板において０.２％耐力９００ＭＰａ以上、さらには９２０ＭＰａ以上といった高強度を得ることは難しい。超微細第二相粒子の個数密度の上限は特に規定する必要はないが、本発明で対象とする化学組成範囲では通常、５.０×１０⁹個／ｍｍ²以下の範囲となる。また、超微細第二相粒子の個数密度は１.５×１０⁹個／ｍｍ²以上であることが好ましい。 (I) Ultrafine second phase particles The “ultrafine second phase particles” referred to in the present specification have a particle diameter of 3 nm or more and 10 nm or less, and are generated by an aging treatment after solution treatment, thereby contributing to strength improvement. As a result of various studies, it is necessary to ensure that the number density of the ultrafine second phase particles is 1.0 × 10 ⁹ particles / mm ² or more. If it is less than that, it is difficult to obtain a high strength such as 0.2% proof stress of 900 MPa or more, and further 920 MPa or more in a thin plate having a thickness of 60 μm or less even if the rolling ratio in finish cold rolling is increased. The upper limit of the number density of the ultrafine second phase particles need not be specified, but is usually in the range of 5.0 × 10 ⁹ particles / mm ² or less in the chemical composition range targeted by the present invention. The number density of the ultrafine second phase particles is preferably 1.5 × 10 ⁹ particles / mm ² or more.

超微細第二相粒子の個数密度の測定は、透過型電子顕微鏡（ＴＥＭ）により１０万倍の倍率で観察した視野中に観測される粒子径３ｎｍ以上１０ｎｍ以下の第二相粒子の数をカウントする方法で行うことができる。観察視野は無作為に１０視野を選択すればよい。ある粒子の粒子径は、観察画像においてその粒子を取り囲む最小円の直径とする。   The number density of ultrafine second phase particles is measured by counting the number of second phase particles having a particle diameter of 3 nm or more and 10 nm or less observed in a visual field observed at a magnification of 100,000 times with a transmission electron microscope (TEM). Can be done in a way. Ten observation fields may be selected at random. The particle diameter of a certain particle is the diameter of the smallest circle that surrounds the particle in the observation image.

（ii）粗大第二相粒子
本明細書でいう「粗大第二相粒子」は粒子径５００ｎｍ以上２０００ｎｍ以下であり、強度向上にはほとんど寄与しない。しかし、この種の粒子が多く存在する状態で冷間圧延すると｛２２０｝配向の圧延集合組織の発達が抑制されることがわかった。従って、仕上冷間圧延前の中間製品の段階で、粗大第二相粒子が十分に存在している必要がある。種々検討の結果、仕上冷間圧延を終えた板厚６０μｍ以下の薄板の測定において粗大第二相粒子の個数密度が１.０×１０⁴個／ｍｍ²以上となるように、時効処理で十分に粗大第二相粒子を生成させることが有効である。粗大第二相粒子の生成が多くなりすぎると超微細第二相粒子の存在密度を上述の範囲に確保することが難しくなる場合がある。粗大第二相粒子は、仕上冷間圧延を終えた薄板の測定において１.０×１０⁵個／ｍｍ²以下となる範囲で存在させることがより好ましい。 (Ii) Coarse second phase particles The “coarse second phase particles” referred to in the present specification have a particle diameter of 500 nm or more and 2000 nm or less, and hardly contribute to strength improvement. However, it has been found that when cold rolling is performed in a state in which a large number of particles of this kind are present, the development of a {220} -oriented rolling texture is suppressed. Therefore, the coarse second phase particles need to be sufficiently present at the intermediate product stage before finish cold rolling. As a result of various investigations, an aging treatment is sufficient so that the number density of coarse second phase particles is 1.0 × 10 ⁴ particles / mm ² or more in measurement of a thin plate having a thickness of 60 μm or less after finishing cold rolling. It is effective to produce coarse second phase particles. If the generation of coarse second-phase particles is excessive, it may be difficult to ensure the density of ultrafine second-phase particles in the above range. More preferably, the coarse second phase particles are present in a range of 1.0 × 10 ⁵ particles / mm ² or less in the measurement of the thin plate after finishing cold rolling.

粗大第二相粒子の個数密度の測定は、板面に平行な電解研磨表面を走査型電子顕微鏡（ＳＥＭ）で観察した視野中に観測される粒子径５００ｎｍ以上２０００ｎｍ以下の第二相粒子の数をカウントする方法で行うことができる。観察倍率は例えば３０００倍とし、観察視野は無作為に１０視野を選択すればよい。ある粒子の粒子径は、観察画像においてその粒子を取り囲む最小円の直径とする。   The number density of coarse second phase particles is measured by measuring the number of second phase particles having a particle diameter of 500 nm or more and 2000 nm or less observed in a visual field obtained by observing an electropolished surface parallel to the plate surface with a scanning electron microscope (SEM). Can be done by counting. The observation magnification may be 3000 times, for example, and 10 observation fields may be selected at random. The particle diameter of a certain particle is the diameter of the smallest circle that surrounds the particle in the observation image.

〔結晶配向〕
圧延を経て製造された銅系材料の板材において、｛２００｝結晶面が板面に平行で且つ＜００１＞方向が圧延方向に平行な結晶の方位はＣｕｂｅ方位と呼ばれる。Ｃｕｂｅ方位の結晶は、板厚方向（ＮＤ）、圧延方向（ＲＤ）、圧延方向と板厚方向に垂直な方向（ＴＤ）の３方向に同等な変形特性を示す。｛２００｝結晶面上のすべり線は、曲げ軸に対して４５°および１３５°と対称性が高いため、せん断帯を形成することなく曲げ変形が可能である。そのため、Ｃｕｂｅ方位の結晶粒は本質的に曲げ加工性が良好である。一方、圧延集合組織に代表される｛２２０｝配向の集合組織の発達は曲げ加工性を低下させる。 (Crystal orientation)
In a copper-based material plate produced by rolling, the crystal orientation with the {200} crystal plane parallel to the plate surface and the <001> direction parallel to the rolling direction is called the Cube orientation. A Cube-oriented crystal exhibits equivalent deformation characteristics in three directions: a plate thickness direction (ND), a rolling direction (RD), and a direction perpendicular to the rolling direction and the plate thickness direction (TD). Since the slip line on the {200} crystal plane has high symmetry of 45 ° and 135 ° with respect to the bending axis, it can be bent without forming a shear band. Therefore, the crystal grains of the Cube orientation have essentially good bending workability. On the other hand, the development of a {220} -oriented texture represented by a rolled texture reduces bending workability.

本発明では、最終的な薄板材において下記（２）式および（３）式を満たす組織状態を実現することによって、曲げ加工性を良好に維持する。
Ｉ｛２００｝／（Ｉ｛１１１｝＋Ｉ｛２２０｝＋Ｉ｛３１１｝）≧０.５０ …（２）
Ｉ｛２２０｝／（Ｉ｛１１１｝＋Ｉ｛２００｝＋Ｉ｛３１１｝）≦０.７５ …（３）
ここで、Ｉ｛ｈｋｌ｝は当該銅合金薄板材板面における｛ｈｋｌ｝結晶面のＸ線回折ピークの積分強度である。
（２）式に代えて下記（２）’式を満たすことがより好ましい。
Ｉ｛２００｝／（Ｉ｛１１１｝＋Ｉ｛２２０｝＋Ｉ｛３１１｝）≧０.６０ …（２）’
（３）式に代えて下記（３）’式を満たすことがより好ましい。
Ｉ｛２２０｝／（Ｉ｛１１１｝＋Ｉ｛２００｝＋Ｉ｛３１１｝）≦０.６５ …（３）’ In the present invention, bending workability is favorably maintained by realizing a microstructure satisfying the following formulas (2) and (3) in the final thin plate material.
I {200} / (I {111} + I {220} + I {311}) ≧ 0.50 (2)
I {220} / (I {111} + I {200} + I {311}) ≦ 0.75 (3)
Here, I {hkl} is the integrated intensity of the X-ray diffraction peak of the {hkl} crystal plane on the copper alloy sheet.
It is more preferable to satisfy the following expression (2) ′ instead of the expression (2).
I {200} / (I {111} + I {220} + I {311}) ≧ 0.60 (2) ′
It is more preferable to satisfy the following expression (3) ′ instead of the expression (3).
I {220} / (I {111} + I {200} + I {311}) ≦ 0.65 (3) ′

〔化学組成〕
本発明で対象とするＣｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系合金の成分元素について説明する。以下、合金元素についての「％」は特に断らない限り「質量％」を意味する。 [Chemical composition]
The component elements of the Cu— [Ni, Co] —Si alloy that is the subject of the present invention will be described. Hereinafter, “%” for an alloy element means “% by mass” unless otherwise specified.

ＮｉおよびＣｏは、それぞれＮｉ−Ｓｉ系析出物およびＣｏ−Ｓｉ系析出物を形成して銅合金板材の強度と導電性を向上させる元素である。その作用を十分に発揮させるために、ＮｉとＣｏの合計含有量を２.５０％以上とする必要がある。Ｎｉ、Ｃｏの少なくとも一方を含有すればよい。ただし、これらの元素の含有量が多すぎると導電率の低下や粗大析出物の生成による曲げ加工時の割れを招く要因となる。種々検討の結果、ＮｉとＣｏの合計含有量は５.００％以下の範囲、さらには４.００％以下の範囲に管理してもよい。なお、ＮｉとＣｏの両方を含有させる場合、Ｎｉは例えば１.００〜３.５０％、Ｃｏは例えば０.５０〜３.００％の範囲で含有量を調整することがより好ましい。   Ni and Co are elements that form Ni—Si-based precipitates and Co—Si-based precipitates, respectively, and improve the strength and conductivity of the copper alloy sheet. In order to fully exhibit the action, the total content of Ni and Co needs to be 2.50% or more. What is necessary is just to contain at least one of Ni and Co. However, when there is too much content of these elements, it becomes a factor which causes the crack at the time of the bending process by the fall of electrical conductivity or the production | generation of a coarse precipitate. As a result of various studies, the total content of Ni and Co may be controlled within a range of 5.00% or less, and further within a range of 4.00% or less. When both Ni and Co are contained, it is more preferable to adjust the content of Ni in the range of, for example, 1.00 to 3.50%, and Co in the range of, for example, 0.50 to 3.00%.

Ｓｉは、Ｎｉ−Ｓｉ系析出物およびＣｏ−Ｓｉ系析出物の形成に必要な元素である。Ｎｉ−Ｓｉ系析出物はＮｉ₂Ｓｉを主体とする化合物であると考えられ、Ｃｏ−Ｓｉ系析出物はＣｏ₂Ｓｉを主体とする化合物であると考えられる。そのために、Ｓｉ含有量は０.５０％以上を確保する。ただし、合金中のＮｉ、ＣｏおよびＳｉは時効処理によって全てが析出物になるとは限らず、ある程度は母相中に固溶した状態で存在する。固溶状態のＮｉ、ＣｏおよびＳｉは銅合金の強度を若干向上させるが、析出状態と比べてその効果は小さく、また、導電率を低下させる原因になる。Ｓｉ含有量は１.５０％以下、より好ましくは１.１０％以下の範囲で調整する。また、できるだけ析出物Ｎｉ₂ＳｉおよびＣｏ₂Ｓｉの組成比に近づける観点から、下記（１）式を満たすように、Ｎｉ、Ｃｏ、Ｓｉの含有量を調整する。
３.５≦（Ｎｉ＋Ｃｏ）／Ｓｉ≦５.０ …（１）
（１）式に代えて下記（１）’式を満たすことがより好ましい。
３.８≦（Ｎｉ＋Ｃｏ）／Ｓｉ≦４.８ …（１）’ Si is an element necessary for forming Ni—Si based precipitates and Co—Si based precipitates. The Ni—Si based precipitate is considered to be a compound mainly composed of Ni ₂ Si, and the Co—Si based precipitate is considered to be a compound mainly composed of Co ₂ Si. Therefore, the Si content is ensured to be 0.50% or more. However, Ni, Co, and Si in the alloy are not necessarily all precipitated by the aging treatment, and exist to some extent in a solid solution state in the matrix. Ni, Co, and Si in a solid solution state slightly improve the strength of the copper alloy, but the effect is small compared to the precipitation state, and causes a decrease in conductivity. The Si content is adjusted in the range of 1.50% or less, more preferably 1.10% or less. Further, from the viewpoint of bringing the composition ratio of the precipitates Ni ₂ Si and Co ₂ Si as close as possible, the contents of Ni, Co, and Si are adjusted so as to satisfy the following expression (1).
3.5 ≦ (Ni + Co) /Si≦5.0 (1)
It is more preferable to satisfy the following formula (1) ′ instead of the formula (1).
3.8 ≦ (Ni + Co) /Si≦4.8 (1) ′

上記以外の任意添加元素として、必要に応じてＦｅ、Ｃｒ、Ｍｇ、Ｍｎ、Ｔｉ、Ｖ、Ｚｒ、Ｓｎ、Ｚｎ、Ａｌ、Ｂ、Ｐ、Ａｇ、Ｂｅ、ＲＥＭ（希土類元素）などを添加してもよい。例えば、Ｓｎは強度および耐応力緩和性の向上させる作用を有し、Ｚｎは銅合金板材のはんだ付け性および鋳造性を改善する作用を有し、Ｍｇも耐応力緩和性を向上させる作用を有する。Ｆｅ、Ｃｒ、Ｍｎ、Ｔｉ、Ｖ、Ｚｒなどは強度を向上させる作用を有する。Ａｇは導電率を大きく低下させずに固溶強化を図る上で有効である。Ｐは脱酸作用、Ｂは鋳造組織を微細化する作用を有し、それぞれ熱間加工性の向上に有効である。また、Ｃｅ、Ｌａ、Ｄｙ、Ｎｄ、ＹなどのＲＥＭ（希土類元素）は結晶粒の微細化や析出物の分散化に有効である。   As optional additional elements other than the above, Fe, Cr, Mg, Mn, Ti, V, Zr, Sn, Zn, Al, B, P, Ag, Be, REM (rare earth element), etc. may be added as necessary. Also good. For example, Sn has an action of improving strength and stress relaxation resistance, Zn has an action of improving solderability and castability of a copper alloy sheet, and Mg also has an action of improving stress relaxation resistance. . Fe, Cr, Mn, Ti, V, Zr, etc. have the effect of improving the strength. Ag is effective in strengthening the solid solution without greatly reducing the electrical conductivity. P has a deoxidizing action, and B has an action of refining the cast structure, and each is effective in improving hot workability. Further, REM (rare earth elements) such as Ce, La, Dy, Nd, and Y is effective for refining crystal grains and dispersing precipitates.

これらの任意添加元素を多量に添加すると、Ｎｉ、Ｃｏ、Ｓｉと化合物を形成する元素もあり、本発明で規定する第二相粒子のサイズと分布の関係を満たすのが難しくなる。また、導電率が低下したり、熱間加工性、冷間加工性に悪影響を及ぼしたりする場合もある。種々検討の結果、これらの元素の含有量はそれぞれ、Ｆｅ：０〜０.１０％、Ｃｒ：０〜０.１０％、Ｍｇ：０〜０.１０％、Ｍｎ：０〜０.１０％、Ｔｉ：０〜０.３０％、Ｖ：０〜０.２０％、Ｚｒ：０〜０.１５％、Ｓｎ：０〜０.１０％、Ｚｎ：０〜０.１５％、Ａｌ：０〜０.２０％、Ｂ：０〜０.０２％、Ｐ：０〜０.１０％、Ａｇ：０〜０.１０％、Ｂｅ：０〜０.１５％、ＲＥＭ（希土類元素）：０〜０.１０％の範囲とすることが望まれる。また、これら任意添加元素は総量で２.０％以下であることが好ましく、１.０％以下あるいは０.５％以下、さらには０.４％以下に管理してもよい。   When these optional additional elements are added in a large amount, some elements form compounds with Ni, Co, and Si, and it becomes difficult to satisfy the relationship between the size and distribution of the second phase particles defined in the present invention. In addition, the electrical conductivity may be lowered, or the hot workability and the cold workability may be adversely affected. As a result of various studies, the contents of these elements are respectively Fe: 0 to 0.10%, Cr: 0 to 0.10%, Mg: 0 to 0.10%, Mn: 0 to 0.10%, Ti: 0 to 0.30%, V: 0 to 0.20%, Zr: 0 to 0.15%, Sn: 0 to 0.10%, Zn: 0 to 0.15%, Al: 0 to 0 .20%, B: 0 to 0.02%, P: 0 to 0.10%, Ag: 0 to 0.10%, Be: 0 to 0.15%, REM (rare earth element): 0 to 0.0. A range of 10% is desirable. Further, the total amount of these optional additive elements is preferably 2.0% or less, and may be controlled to 1.0% or less, 0.5% or less, and further 0.4% or less.

〔板厚〕
コネクタをはじめとする通電部品の小型化ニーズに対応できるよう、本発明では板厚２０〜６０μｍの薄板材を対象とする。板厚３０〜５５μｍ以下の薄板材を対象とすることがより効果的である。なお、板厚が６０μｍを超えて厚いＣｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金板材については、本明細書で開示する製造技術に従わなくても、例えば本出願人が特願２０１３−０２７１７２号にて開示した技術などを利用することで、０.２％耐力９００ＭＰａを十分に上回る強度レベルの板材を実現することが可能である。 [Thickness]
In order to meet the downsizing needs of current-carrying parts such as connectors, the present invention targets a thin plate material having a thickness of 20 to 60 μm. It is more effective to target a thin plate material having a plate thickness of 30 to 55 μm or less. In addition, about Cu- [Ni, Co] -Si type copper alloy board | plate material with a board thickness exceeding 60 micrometers, even if it does not follow the manufacturing technique disclosed by this specification, this applicant, for example, Japanese Patent Application No. 2013-027172. It is possible to realize a plate material having a strength level sufficiently exceeding 0.2% proof stress 900 MPa by utilizing the technology disclosed in the issue.

〔特性〕
コネクタなどの通電部品においては、部品の端子部分（挿入部分）において、挿入時の応力負荷による座屈、変形が生じない高強度が必要である。そのためには、圧延方向０.２％耐力が９００ＭＰａ以上であることが望ましく、９２０ＭＰａ以上であることが一層好ましい。過剰な高強度化は曲げ加工性の低下を招くので、通常は圧延方向の０.２％耐力が例えば１０００ＭＰａ以下の範囲で強度レベル調整すればよく、９８０ＭＰａ以下の範囲に管理してもよい。 〔Characteristic〕
In a current-carrying component such as a connector, the terminal portion (insertion portion) of the component needs to have high strength that does not buckle or deform due to a stress load at the time of insertion. For that purpose, the 0.2% proof stress in the rolling direction is desirably 900 MPa or more, and more preferably 920 MPa or more. An excessive increase in strength leads to a decrease in bending workability. Therefore, the strength level is usually adjusted in a range where the 0.2% proof stress in the rolling direction is, for example, 1000 MPa or less, and may be controlled in a range of 980 MPa or less.

曲げ加工性については、板厚６０μｍ以下の薄板材の場合、ＪＩＳ Ｈ３１１０に従う９０°Ｗ曲げ試験においてＢＷのＭＢＲ／ｔが１.０以下となる特性を有していれば、想定される多くの用途に適用可能である。ＢＷのＭＢＲ／ｔが０.８以下であることがより好ましい。導電率は３５％ＩＡＣＳ以上であることが望ましく、４０％ＩＡＣＳ以上であることがより好ましい。   As for the bending workability, in the case of a thin plate material having a thickness of 60 μm or less, it is assumed that there are many expected properties as long as the MBR / t of BW is 1.0 or less in a 90 ° W bending test according to JIS H3110. Applicable for use. The MBR / t of BW is more preferably 0.8 or less. The conductivity is desirably 35% IACS or more, and more preferably 40% IACS or more.

〔製造方法〕
上述の高強度銅合金薄板材は、熱間圧延、溶体化処理、時効処理、仕上冷間圧延の各工程を含むプロセスにて製造することができる。ただし、特に溶体化処理と時効処理においては、製造条件に工夫を要する。一連のプロセスとして、「溶解・鋳造→熱間圧延→冷間圧延→溶体化処理→（時効前冷間圧延）→時効処理→仕上冷間圧延→低温焼鈍」のプロセスを例示することができる。以下、各工程における製造条件を例示する。なお、必要に応じて面削や酸洗を実施することができる。 〔Production method〕
The above-described high-strength copper alloy sheet material can be manufactured by a process including steps of hot rolling, solution treatment, aging treatment, and finish cold rolling. However, in particular, in the solution treatment and the aging treatment, it is necessary to devise manufacturing conditions. As a series of processes, a process of “melting / casting → hot rolling → cold rolling → solution treatment → (cold rolling before aging) → aging treatment → finish cold rolling → low temperature annealing” can be exemplified. Hereinafter, production conditions in each step will be exemplified. In addition, chamfering or pickling can be performed as necessary.

〔溶解・鋳造〕
一般的な銅合金の溶製方法と同様の方法により、銅合金の原料を溶解した後、連続鋳造や半連続鋳造などにより鋳片を製造することができる。なお、鋳造後には、鋳造組織の状態により必要に応じて鋳片を均質化焼鈍に供することができる。均質化焼鈍は例えば１０００〜１０６０℃で１〜１０ｈ加熱する条件にて行えばよい。均質化焼鈍は次工程の熱間圧延における加熱工程を利用してもよい。 [Melting / Casting]
A slab can be 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. In addition, after casting, the slab can be subjected to homogenization annealing as necessary depending on the state of the cast structure. Homogenization annealing may be performed, for example on the conditions heated at 1000-1060 degreeC for 1 to 10 hours. Homogenization annealing may utilize the heating process in the next hot rolling.

〔熱間圧延〕
まず鋳片を十分に加熱する。例えば１０００〜１０６０℃で３ｈ以上加熱することが望ましい。その後、炉から抽出して圧延する。圧延最終パスの温度（圧延終了温度）を６５０℃以上とし、６５０℃から３００℃までの平均冷却速度を１０℃／ｓｅｃ以上とする。この熱間圧延条件を採用することにより、鋳造時に晶出または析出した極めて粗大な第二相の固溶を進行させるとともに、圧延最終パス後の冷却過程で粗大な第二相が生成することを防止する。 (Hot rolling)
First, the slab is heated sufficiently. For example, it is desirable to heat at 1000 to 1060 ° C. for 3 hours or more. Thereafter, it is extracted from the furnace and rolled. The temperature of the final rolling pass (rolling end temperature) is 650 ° C. or higher, and the average cooling rate from 650 ° C. to 300 ° C. is 10 ° C./sec or higher. By adopting this hot rolling condition, it is possible to advance the solid solution of the very coarse second phase crystallized or precipitated during casting, and to produce a coarse second phase in the cooling process after the final rolling pass. To prevent.

〔冷間圧延〕
時効処理後の仕上冷間圧延にて目的の板厚に調整できるように、時効処理前の段階で板厚を減じておくことができる。必要に応じて中間焼鈍を挟んだ複数回の冷間圧延工程を実施してもよい。このあとの溶体化処理を連続ラインにて行う場合には、あまり板厚が薄いと、板折れ等のトラブルを招きやすくなるので、一般的には０.１ｍｍ以上の板厚を確保しておくことが望ましい。また、溶体化処理での再結晶化を促進させる観点からは、５０％以上の冷間圧延率を付与しておくことが有効である。なお、圧延率は下記（６）式により表される。
圧延率Ｒ（％）＝（ｈ₀−ｈ₁）／ｈ₀×１００ …（６）
ここで、ｈ₀は圧延前の板厚（ｍｍ）、ｈ₁は圧延後の板厚（ｍｍ）である。 (Cold rolling)
The plate thickness can be reduced at the stage before the aging treatment so that the finish can be adjusted to the desired thickness by cold rolling after finishing the aging treatment. You may implement the cold rolling process of the multiple times which pinched | interposed intermediate annealing as needed. When the subsequent solution treatment is performed on a continuous line, if the plate thickness is too thin, troubles such as plate breakage are likely to occur. Therefore, in general, a plate thickness of 0.1 mm or more is ensured. It is desirable. From the viewpoint of promoting recrystallization in the solution treatment, it is effective to give a cold rolling rate of 50% or more. In addition, a rolling rate is represented by following (6) Formula.
Rolling ratio R (%) = (h ₀ −h ₁ ) / h ₀ × 100 (6)
Here, h ₀ is the plate thickness (mm) before rolling, and h ₁ is the plate thickness (mm) after rolling.

〔溶体化処理〕
溶体化処理の昇温過程では、８００℃から９５０℃までの平均昇温速度を５０℃／ｓｅｃ以上とすることが重要である。この急速昇温により溶体化処理後の再結晶集合組織における｛２００｝配向が向上する。急速昇温により組織全体を迅速に再結晶化させることが｛２００｝配向の形成に有効に作用するものと考えられる。９５０℃に達した後、９５０〜１０２０℃の範囲で５〜３００ｓｅｃ保持して第二相粒子を固溶させる。その後の冷却過程では９５０℃から６５０℃までの平均冷却速度を１０〜３０℃／ｓｅｃとする。この温度域は第二相粒子が活発に析出する温度域より高温であるが、第二相粒子がほぼ固溶消失している組織状態において、この温度域での滞在時間を十分に確保することにより、時効処理で粗大第二相粒子を形成するための核を発生させることができるのである。なお、６５０℃から常温までは、水冷等により急冷することが好ましい。 [Solution treatment]
In the temperature raising process of the solution treatment, it is important to set the average temperature raising rate from 800 ° C. to 950 ° C. to 50 ° C./sec or more. This rapid temperature increase improves the {200} orientation in the recrystallized texture after the solution treatment. It is considered that rapidly recrystallizing the entire structure by rapid temperature increase effectively acts on the formation of {200} orientation. After reaching 950 ° C., the second phase particles are dissolved by holding for 5 to 300 seconds in the range of 950 to 1020 ° C. In the subsequent cooling process, the average cooling rate from 950 ° C. to 650 ° C. is set to 10 to 30 ° C./sec. This temperature range is higher than the temperature range in which the second phase particles are actively precipitated, but in the structure where the second phase particles are almost dissolved, the residence time in this temperature range should be sufficiently secured. Thus, nuclei for forming coarse second phase particles can be generated by aging treatment. In addition, it is preferable to quench rapidly by water cooling etc. from 650 degreeC to normal temperature.

〔時効前冷間圧延〕
溶体化処理後の材料に対し、必要に応じて時効処理前に冷間圧延を施すことができる。ただし、圧延率を高くすると｛２２０｝配向が発達してしまう。種々検討の結果、時効処理前に冷間圧延を施すときは、その圧延率を５０％以下とすることが望ましい。 [Cold rolling before aging]
If necessary, the material after the solution treatment can be cold-rolled before the aging treatment. However, when the rolling rate is increased, {220} orientation develops. As a result of various studies, when cold rolling is performed before the aging treatment, it is desirable that the rolling rate be 50% or less.

〔時効処理〕
時効処理では、強度に寄与する超微細第二相粒子をできるだけ多く析出させながら、粗大第二相粒子を生成させる。そのために、やや過時効側での時効条件を採用する。具体的には、時効処理後の圧延方向引張強さＴＳ(age)（ＭＰａ）および導電率ＥＣ(age)（％ＩＡＣＳ）がそれぞれ下記（４）式および（５）式を満たす時効条件を適用する。
０.９０≦ＴＳ(age)／ＴＳ(max)≦０.９７ …（４）
１.０５≦ＥＣ(age)／ＥＣ(tsmax)≦１.２０ …（５）
ここで、ＴＳ(max)は、前記溶体化処理後の当該材料に対して、３５０℃から６００℃までの１０℃刻みの各温度で６ｈ保持する時効処理を施したときに得られる圧延方向最大引張強さ（ＭＰａ）であり、ＥＣ(tsmax)は、前記ＴＳ(max)が得られた試料における導電率（％ＩＡＣＳ）である。
（５）式に代えて下記（５）’式を適用することがより好ましい。
１.０５≦ＥＣ(age)／ＥＣ(tsmax)≦１.１５ …（５）’
このような時効温度、時効時間の適正範囲は、合金組成に応じて予め予備実験により求めておくことができる。通常、時効温度４２５〜５２５℃、時効時間３〜１５ｈの範囲内に上記適切な条件を見出すことができる。 [Aging treatment]
In the aging treatment, coarse second-phase particles are generated while depositing as many ultrafine second-phase particles that contribute to strength as possible. Therefore, the aging condition on the slightly overaging side is adopted. Specifically, the aging conditions in which the tensile strength TS (age) (MPa) and the electrical conductivity EC (age) (% IACS) after the aging treatment satisfy the following formulas (4) and (5) are applied. To do.
0.90 ≦ TS (age) / TS (max) ≦ 0.97 (4)
1.05 ≦ EC (age) / EC (tsmax) ≦ 1.20 (5)
Here, TS (max) is the maximum in the rolling direction obtained when the material after the solution treatment is subjected to an aging treatment for 6 hours at each temperature of 10 ° C. from 350 ° C. to 600 ° C. It is the tensile strength (MPa), and EC (tsmax) is the electrical conductivity (% IACS) in the sample from which the TS (max) was obtained.
It is more preferable to apply the following formula (5) ′ instead of formula (5).
1.05 ≦ EC (age) / EC (tsmax) ≦ 1.15 (5) ′
Such appropriate ranges of aging temperature and aging time can be obtained in advance by preliminary experiments according to the alloy composition. Usually, the appropriate conditions can be found within the range of aging temperature of 425 to 525 ° C. and aging time of 3 to 15 hours.

溶体化処理の冷却過程で第二相の核を生成してあるので、やや過時効側で時効処理することにより、前記の核に起因する第二相粒子を適切に成長させて粗大第二相粒子の数を十分に確保することが可能となる。また、母相の新たな箇所から多数の第二相粒子が発生し、これが超微細第二相粒子となる。また、やや過時効側を狙うことにより導電率の向上にも有利となる。   Since the second phase nuclei are generated in the cooling process of the solution treatment, the second phase particles due to the nuclei are appropriately grown by aging treatment on the slightly overaged side, and the coarse second phase. It is possible to secure a sufficient number of particles. In addition, a large number of second phase particles are generated from a new portion of the parent phase and become ultrafine second phase particles. Moreover, it becomes advantageous also for the electrical conductivity improvement by aiming at an overaging side a little.

〔仕上冷間圧延〕
この仕上冷間圧延では、厚さ６０μｍ以下の薄板材（箔）にまで板厚を減少させるとともに、加工硬化を利用して強度レベルの更なる向上を図る。時効処理により所定量の粗大第二相粒子が分散した組織としてあるので、冷間圧延率の増大に伴う｛２２０｝配向の過度な発達が抑制されるが、圧延方向の０.２％耐力が９００ＭＰａ以上となり、９０°Ｗ曲げ試験においてＢＷのＭＢＲ／ｔが１.０以下に維持される範囲で冷間圧延率を設定する。上述の各工程条件に従った場合、この仕上冷間圧延率は通常、２０〜９０％、好ましくは３０〜８０％、より好ましくは３５〜７５％の範囲内で設定することができる。 [Finish cold rolling]
In this finish cold rolling, the plate thickness is reduced to a thin plate material (foil) having a thickness of 60 μm or less, and work strength is used to further improve the strength level. Since a predetermined amount of coarse second-phase particles is dispersed by aging treatment, excessive development of {220} orientation with an increase in cold rolling rate is suppressed, but 0.2% proof stress in the rolling direction is suppressed. The cold rolling rate is set in a range where the pressure becomes 900 MPa or more and the MBR / t of BW is maintained at 1.0 or less in the 90 ° W bending test. When the above-mentioned process conditions are followed, this finish cold rolling rate can be generally set within a range of 20 to 90%, preferably 30 to 80%, and more preferably 35 to 75%.

〔低温焼鈍〕
仕上冷間圧延の後には、残留応力の低減、ばね限界値と耐応力緩和特性の向上を目的として、低温焼鈍を施してもよい。加熱温度は１５０〜５５０℃の範囲で設定するのが好ましい。３００〜５００℃の範囲とすることがより好ましい。加熱時間は５ｓｅｃ以上の範囲で設定することができる。３０ｓｅｃ〜１ｈの範囲で設定することがより好ましい。 [Low temperature annealing]
After finish cold rolling, low-temperature annealing may be performed for the purpose of reducing residual stress and improving spring limit values and stress relaxation resistance. The heating temperature is preferably set in the range of 150 to 550 ° C. More preferably, the temperature is in the range of 300 to 500 ° C. The heating time can be set in the range of 5 seconds or more. It is more preferable to set in the range of 30 sec to 1 h.

表１に示す化学組成の銅合金を高周波溶解炉にて溶解し、得られた鋳片を１０３０℃で４ｈ均質化焼鈍した。その後、熱間圧延→冷間圧延→溶体化処理→（時効前冷間圧延）→時効処理→仕上冷間圧延→低温焼鈍の工程で板厚３０〜５５μｍ以下の銅合金薄板材（供試材）を作製した。熱間圧延以降の工程は以下のようにして行った。   A copper alloy having the chemical composition shown in Table 1 was melted in a high-frequency melting furnace, and the obtained slab was homogenized and annealed at 1030 ° C. for 4 hours. Thereafter, a copper alloy thin plate material having a thickness of 30 to 55 μm or less (test material) in the steps of hot rolling → cold rolling → solution treatment → (cold rolling before aging) → aging treatment → finish cold rolling → low temperature annealing ) Was produced. The processes after hot rolling were performed as follows.

上記均質化焼鈍後の鋳片を炉から取り出し、熱間圧延を行い、冷却した。放射温度計を用いて板表面の温度をモニターし、圧延終了温度、および６５０℃から３００℃までの平均冷却速度（ただし、圧延終了温度が６５０℃未満の場合は当該圧延終了温度から３００℃までの平均冷却速度）を求めた。なお、６５０℃から３００℃までの平均冷却速度は、（６５０−３００）／ｔ₁により定まる。ここでｔ₁は６５０℃から３００℃までの所要時間（ｓｅｃ）である。得られた熱延材の表面酸化層を機械研磨により除去し、板厚１０ｍｍの板材を得た。次いで冷間圧延を施して板厚０.１０〜０.１４ｍｍの冷延材とした。ただし、一部の例（Ｎｏ.３４）では板厚０.０８ｍｍの冷延材とした。 The slab after the homogenization annealing was taken out of the furnace, subjected to hot rolling and cooled. The temperature of the plate surface is monitored using a radiation thermometer, and the rolling end temperature and the average cooling rate from 650 ° C. to 300 ° C. (however, when the rolling end temperature is less than 650 ° C., from the rolling end temperature to 300 ° C.) Average cooling rate). The average cooling rate from 650 ° C. to 300 ° C. is determined by (650−300) / t ₁ . Here, t ₁ is a required time (sec) from 650 ° C. to 300 ° C. The surface oxide layer of the obtained hot rolled material was removed by mechanical polishing to obtain a plate material having a plate thickness of 10 mm. Next, cold rolling was performed to obtain a cold rolled material having a thickness of 0.10 to 0.14 mm. However, in some examples (No. 34), a cold-rolled material having a thickness of 0.08 mm was used.

上記冷延材に対して、溶体化処理を施した。昇温速度を制御し、１０００℃に設定した保持温度まで昇温した。１０００℃に到達後、１ｍｉｎ保持し、その後、６５０℃までの冷却速度を制御し、６５０℃を下回ってから水冷した。試料表面に取り付けた熱電対により温度変化をモニターし、８００℃から９５０℃までの平均昇温速度（℃／ｓｅｃ）および９５０℃から６５０℃までの平均冷却速度（℃／ｓｅｃ）を求めた。なお、８００℃から９５０℃までの平均昇温速度は、（９５０−８００）／ｔ₂により定まる。ここでｔ₂は８００℃から９５０℃までの所要時間（ｓｅｃ）である。同様に、９５０℃から６５０℃までの平均冷却速度は、（９５０−６５０）／ｔ₃により定まる。ここでｔ₃は９５０℃から６５０℃までの所要時間（ｓｅｃ）である。 The cold-rolled material was subjected to a solution treatment. The temperature elevation rate was controlled and the temperature was raised to a holding temperature set at 1000 ° C. After reaching 1000 ° C., it was held for 1 min, and then the cooling rate to 650 ° C. was controlled, and after cooling below 650 ° C., water cooling was performed. The temperature change was monitored by a thermocouple attached to the surface of the sample, and the average heating rate (° C./sec) from 800 ° C. to 950 ° C. and the average cooling rate (° C./sec) from 950 ° C. to 650 ° C. were obtained. The average rate of temperature increase from 800 ° C. to 950 ° C. is determined by (950−800) / t ₂ . Here, t ₂ is a required time (sec) from 800 ° C. to 950 ° C. Similarly, the average cooling rate from 950 ° C. to 650 ° C. is determined by (950−650) / t ₃ . Here, t ₃ is a required time (sec) from 950 ° C. to 650 ° C.

溶体化処理後の板材から時効処理条件を把握するための予備実験用試料を採取し、３５０℃から６００℃までの１０℃刻みの各温度で６ｈ保持する予備実験を行い、圧延方向引張強さと、導電率を測定した。上記各温度での引張強さの最大値である圧延方向最大引張強さＴＳ(max)を定めるとともに、そのＴＳ(max)が得られた試料の導電率ＥＣ(tsmax)を定めた。   Preliminary test samples for grasping the aging treatment conditions were collected from the plate material after solution treatment, and preliminary experiments were conducted for 6 hours at each temperature in increments of 10 ° C from 350 ° C to 600 ° C. The conductivity was measured. The maximum tensile strength TS (max) in the rolling direction, which is the maximum tensile strength at each temperature, was determined, and the electrical conductivity EC (tsmax) of the sample from which the TS (max) was obtained was determined.

溶体化処理後には、一部の例において時効前冷間圧延を施した。
上記予備実験のデータに基づき、溶体化処理後の板材（時効前冷間圧延を施した例では時効前冷間圧延後の板材）に、一部の例を除き、やや過時効側となる時効条件を狙って時効処理を施した。時効処理後の板材から試料を採取して、圧延方向引張強さＴＳ(age)および導電率ＥＣ(age)を測定し、ＴＳ(age)／ＴＳ(max)およびＥＣ(age)／ＥＣ(tsmax)を算出した。 After the solution treatment, pre-aging cold rolling was performed in some examples.
Based on the data from the above preliminary experiment, except for some examples of the plate material after solution treatment (the plate material after cold rolling before aging in the case of cold rolling before aging), the aging is slightly over-aged. Aging treatment was applied for the conditions. A sample is taken from the plate after the aging treatment, the tensile strength TS (age) in the rolling direction and the electrical conductivity EC (age) are measured, and TS (age) / TS (max) and EC (age) / EC (tsmax ) Was calculated.

時効処理後の板材に仕上冷間圧延を施し、板厚３０〜５５μｍ以下の薄板材（箔）を得た。仕上冷間圧延率は２０〜９０％の範囲とした。その後、１５０〜５５０℃で５ｓｅｃ〜１ｈ保持する低温焼鈍を施し、供試材とした。
製造条件を表２に示す。 The plate material after the aging treatment was subjected to finish cold rolling to obtain a thin plate material (foil) having a thickness of 30 to 55 μm or less. The finish cold rolling rate was in the range of 20 to 90%. Thereafter, low temperature annealing was performed at 150 to 550 ° C. for 5 sec to 1 h to obtain a test material.
The manufacturing conditions are shown in Table 2.

〔第二相粒子の個数密度〕
各供試材について、粒子径３ｎｍ以上１０ｎｍ以下の「超微細第二相粒子」、および粒子径５００ｎｍ以上２０００ｎｍ以下の「粗大第二相粒子」の個数密度を測定した。
超微細第二相粒子については、透過型電子顕微鏡（ＴＥＭ）により１０万倍の写真を無作為に選択した１０視野について撮影し、それらの写真上で超微細第二相粒子あるいは微細第二相粒子に該当する粒子の数をカウントすることによって個数密度を算出した。
粗大第二相粒子については、板面に平行な電解研磨表面を走査型電子顕微鏡（ＳＥＭ）で観察し、３０００倍の写真を無作為に選択した１０視野について撮影し、その写真上で粗大第二相粒子に該当する粒子の数をカウントすることによって個数密度を算出した。電解研磨はリン酸、エタノール、純水の混合溶液を用いた。
粒径は、いずれの場合も、各粒子を取り囲む最小円の直径とした。 [Number density of second phase particles]
For each specimen, the number density of “ultrafine second phase particles” having a particle size of 3 nm to 10 nm and “coarse second phase particles” having a particle size of 500 nm to 2000 nm was measured.
Ultra fine second phase particles were photographed for 10 fields of view randomly selected with a transmission electron microscope (TEM) at a magnification of 100,000 times, and ultra fine second phase particles or fine second phase on those photographs. The number density was calculated by counting the number of particles corresponding to the particles.
As for the coarse second phase particles, the electropolished surface parallel to the plate surface was observed with a scanning electron microscope (SEM), and the photograph of 3000 fields of view was randomly selected, and the coarse second phase particle was observed on the photograph. The number density was calculated by counting the number of particles corresponding to the two-phase particles. The electrolytic polishing used a mixed solution of phosphoric acid, ethanol and pure water.
In all cases, the particle diameter was the diameter of the smallest circle surrounding each particle.

〔Ｘ線回折強度比〕
Ｘ線回折装置を用いて、Ｃｕ−Ｋα線、管電圧４０ｋＶ、管電流２０ｍＡの条件で各供試材の板面（圧延面）についてＸ線回折パターンを測定し、｛２００｝面、｛１１１｝面、｛２２０｝面、｛３１１｝面の各回折ピークの積分強度を求めた。なお、試料圧延面に明らかな酸化が認められた場合には、酸洗または＃１５００耐水ペーパーで研磨仕上した試料を使用した。 [X-ray diffraction intensity ratio]
Using an X-ray diffractometer, an X-ray diffraction pattern was measured for the plate surface (rolled surface) of each test material under the conditions of Cu-Kα ray, tube voltage 40 kV, tube current 20 mA, and {200} plane, {111 } The integrated intensity of each diffraction peak on the {plane}, {220} plane, and {311} plane was determined. In addition, when obvious oxidation was recognized on the sample rolling surface, the sample polished and finished with pickling or # 1500 water-resistant paper was used.

〔導電率〕
供試材から採取した試料について、ＪＩＳ Ｈ０５０５の導電率測定方法に従って測定した。
〔０.２％耐力〕
供試材の圧延方向に平行な引張試験用の試験片（ＪＩＳ ＺＪ２２４１の５号試験片）をそれぞれ３個ずつ採取し、ＪＩＳ ＺＪ２２４１に従って引張試験を行い、その平均値によって０.２％耐力を求めた。 〔conductivity〕
About the sample extract | collected from the test material, it measured according to the electrical conductivity measuring method of JISH0505.
[0.2% yield strength]
Three specimens for tensile test (No. 5 test piece of JIS ZJ2241) parallel to the rolling direction of the specimen are sampled and subjected to a tensile test according to JIS ZJ2241, and 0.2% proof stress is obtained by the average value. Asked.

〔曲げ加工性〕
供試材から、曲げ軸が圧延平行方向となるＢＷの曲げ試験片（幅１０ｍｍ、長さ３０ｍｍ）を採取し、ＪＩＳ Ｈ３１１０に従って９０°Ｗ曲げ試験を行った。この試験後の試験片について、曲げ加工部の表面を光学顕微鏡によって１００倍の倍率で観察して、割れが発生しない最小曲げ半径ＭＢＲと板厚ｔの比ＭＢＲ／ｔを求めた。このＭＢＲ／ｔが１.０以下であるものはコネクタ等の電気・電子部品への加工において十分な曲げ加工性を有すると判断できる。
以上の結果を表３に示す。 [Bending workability]
A BW bending test piece (width 10 mm, length 30 mm) having a bending axis parallel to the rolling direction was taken from the test material, and a 90 ° W bending test was performed in accordance with JIS H3110. With respect to the test piece after this test, the surface of the bending portion was observed with an optical microscope at a magnification of 100 times to determine the ratio MBR / t of the minimum bending radius MBR and the thickness t where no cracks occurred. When MBR / t is 1.0 or less, it can be determined that the material has sufficient bending workability in processing of electrical and electronic parts such as connectors.
The above results are shown in Table 3.

表３からわかるように、第二相粒子の個数密度および結晶配向が適正範囲にある本発明例のものは、板厚５５μｍ以下のＣｕ−［Ｎｉ，Ｃｏ］−Ｓｉ系銅合金薄板材（箔）において、０.２％耐力が９２０ＭＰａ以上の高強度と、ＢＷのＭＢＲ／ｔが１.０以下の良好な曲げ加工性を両立し、導電率も３５％ＩＡＣＳ以上と良好であった。   As can be seen from Table 3, the sample of the present invention in which the number density and crystal orientation of the second phase particles are in the proper ranges are the Cu- [Ni, Co] -Si-based copper alloy sheet (foil) having a thickness of 55 μm or less. ), A high strength with a 0.2% proof stress of 920 MPa or more and a good bending workability with an MBR / t of BW of 1.0 or less were compatible, and the electrical conductivity was also good with 35% IACS or more.

これに対し、比較例Ｎｏ.３１は時効処理条件を過時効側にシフトさせる程度が不足したので粗大第二相粒子の量が少なくなり、仕上冷間圧延で｛２２０｝配向の発達抑制が不十分となって曲げ加工性に劣った。Ｎｏ.３２は逆に過時効の程度が大きすぎたので超微細第二相粒子の数が減り、０.２％耐力が低下した。Ｎｏ.３３は過時効側での時効処理を実施しなかったので粗大第二相粒子の生成量が不足し、仕上冷間圧延で｛２２０｝配向の発達抑制が不十分となって曲げ加工性に劣った。また、導電性にも劣った。Ｎｏ.３４は熱間圧延後に冷間圧延で０.０８ｍｍまで圧延したのち溶体化処理を行ったが、シワが多く発生し、時効処理後の仕上圧延時に破断してしまった。Ｎｏ.３５は溶体化処理の冷却過程で６５０℃以上の温度域での冷却速度が速すぎたので第二相粒子の核生成が不十分となり、時効処理で十分な量の粗大第二相粒子を生成させることができなかった。その結果、仕上冷間圧延で｛２２０｝配向が発達し、曲げ加工性に劣った。Ｎｏ.３６は逆に溶体化処理の冷却過程で６５０℃以上の温度域での冷却速度が遅すぎたので時効処理後の粗大第二相粒子の数が多くなりすぎ、それに伴って超微細第二相粒子の数が不足したことにより０.２％耐力が低かった。Ｎｏ.３７は溶体化処理の昇温過程で８００℃以上の温度域での昇温速度が遅すぎたので｛２００｝配向に十分に富んだ再結晶集合組織が得られず、結果的に仕上冷間圧延後の｛２００｝配向が不足して曲げ加工性に劣った。Ｎｏ.３８は熱間圧延で３００℃以上の温度域での冷却速度が遅すぎたことにより、その冷却過程で粗大第二相粒子が多量に生成し、溶体化処理後に粗大第二相粒子が残留した。その結果、時効処理で超微細第二相粒子を十分に生成させることができず、０.２％耐力が低かった。Ｎｏ.３９は熱間圧延最終パス温度が低すぎたので鋳造時に生じた極めて粗大な第二相の固溶が不十分となり、溶体化処理後に粗大第二相粒子が残留した。その結果、やはり超微細第二相粒子の生成量が不足し、０.２％耐力が低かった。   On the other hand, Comparative Example No. 31 lacked the degree of shifting the aging treatment condition to the overaging side, so the amount of coarse second phase particles was reduced, and there was no inhibition of {220} orientation development in finish cold rolling. Insufficient bending workability. On the contrary, in No. 32, since the degree of overaging was too large, the number of ultrafine second phase particles was reduced, and the 0.2% yield strength was lowered. No. 33 was not subjected to an aging treatment on the overaging side, so the amount of coarse second phase particles was insufficient, and the development of {220} orientation was insufficiently suppressed in finish cold rolling, resulting in bending workability. Inferior to Moreover, it was inferior also in electroconductivity. No. 34 was hot-rolled and then cold-rolled to 0.08 mm and then subjected to a solution treatment. However, many wrinkles were generated, and fracture occurred during finish rolling after the aging treatment. In No. 35, since the cooling rate in the temperature range of 650 ° C. or higher was too fast during the cooling process of the solution treatment, the nucleation of the second phase particles was insufficient, and a sufficient amount of coarse second phase particles were obtained by the aging treatment. Could not be generated. As a result, {220} orientation was developed by finish cold rolling, and the bending workability was poor. No. 36, on the contrary, was too slow in the solution treatment cooling process in the temperature range of 650 ° C. or more, so the number of coarse second-phase particles after aging treatment was too large. The 0.2% yield strength was low due to the insufficient number of two-phase particles. In No. 37, since the rate of temperature increase in the temperature range of 800 ° C. or higher was too slow during the temperature increase process of the solution treatment, a recrystallized texture sufficiently rich in {200} orientation could not be obtained, and as a result The {200} orientation after cold rolling was insufficient and the bending workability was poor. No. 38 was hot-rolled and the cooling rate in the temperature range of 300 ° C. or higher was too slow, so that a large amount of coarse second-phase particles were produced in the cooling process. Remained. As a result, the ultrafine second phase particles could not be sufficiently generated by the aging treatment, and the 0.2% proof stress was low. In No. 39, the final pass temperature of hot rolling was too low, so that the extremely coarse second phase solid solution generated during casting became insufficient, and coarse second phase particles remained after the solution treatment. As a result, the production amount of ultrafine second phase particles was still insufficient, and the 0.2% proof stress was low.

Ｎｏ.４０は銅合金中のＮｉとＣｏの合計含有量が多すぎたので導電率が低かった。Ｎｏ.４１は逆にＮｉとＣｏの合計含有量が少なすぎたので超微細第二相粒子の析出量が不足し、０.２％耐力が低かった。Ｎｏ.４２は（Ｎｉ＋Ｃｏ）／Ｓｉの含有量比が小さすぎたので仕上冷間圧延後の｛２００｝配向の維持が不十分となり、曲げ加工性に劣った。Ｎｏ.４３はＳｎ含有量が高すぎたので導電率が低かった。Ｎｏ.４４はＣｒ含有量が高すぎたのでＳｉがクロム化合物の生成に消費され、その結果、微細第二相粒子の析出量を十分に確保することができず、０.２％耐力が低下した。   No. 40 had a low electrical conductivity because the total content of Ni and Co in the copper alloy was too much. On the other hand, No. 41 had too little total content of Ni and Co, so the precipitation amount of ultrafine second phase particles was insufficient, and the 0.2% proof stress was low. In No. 42, since the content ratio of (Ni + Co) / Si was too small, the maintenance of {200} orientation after finish cold rolling became insufficient, and the bending workability was poor. No. 43 had a low conductivity because the Sn content was too high. In No. 44, since the Cr content was too high, Si was consumed for the production of the chromium compound. As a result, the precipitation amount of the fine second phase particles could not be secured sufficiently, and the 0.2% yield strength was lowered. did.

Claims (5)

質量％で、ＮｉとＣｏの合計：２.５０〜５.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.１０％、Ｃｒ：０〜０.１０％、Ｍｇ：０〜０.１０％、Ｍｎ：０〜０.１０％、Ｔｉ：０〜０.３０％、Ｖ：０〜０.２０％、Ｚｒ：０〜０.１５％、Ｓｎ：０〜０.１０％、Ｚｎ：０〜０.１５％、Ａｌ：０〜０.２０％、Ｂ：０〜０.０２％、Ｐ：０〜０.１０％、Ａｇ：０〜０.１０％、Ｂｅ：０〜０.１５％、ＲＥＭ（希土類元素）：０〜０.１０％であり、残部Ｃｕおよび不可避的不純物からなり、かつ下記（１）式を満たす化学組成を有し、母相中に存在する第二相粒子のうち、粒子径３ｎｍ以上１０ｎｍ以下の「超微細第二相粒子」の個数密度が１.０×１０⁹個／ｍｍ²以上であり、下記（２）式および（３）式のＸ線回折強度比を満たし、圧延方向の０.２％耐力が９００ＭＰａ以上、導電率が３５％ＩＡＣＳ以上であり、板厚が２０〜６０μｍである高強度銅合金薄板材。
３.５≦（Ｎｉ＋Ｃｏ）／Ｓｉ≦５.０ …（１）
ここで、（１）式の元素記号の箇所には当該元素の含有量値（質量％）が代入される。
Ｉ｛２００｝／（Ｉ｛１１１｝＋Ｉ｛２２０｝＋Ｉ｛３１１｝）≧０.５０ …（２）
Ｉ｛２２０｝／（Ｉ｛１１１｝＋Ｉ｛２００｝＋Ｉ｛３１１｝）≦０.７５ …（３）
ここで、Ｉ｛ｈｋｌ｝は当該銅合金薄板材板面における｛ｈｋｌ｝結晶面のＸ線回折ピークの積分強度である。 In mass%, the total of Ni and Co: 2.50 to 5.00%, Si: 0.50 to 1.50%, Fe: 0 to 0.10%, Cr: 0 to 0.10%, Mg: 0 to 0.10%, Mn: 0 to 0.10%, Ti: 0 to 0.30%, V: 0 to 0.20%, Zr: 0 to 0.15%, Sn: 0 to 0.10 %, Zn: 0 to 0.15%, Al: 0 to 0.20%, B: 0 to 0.02%, P: 0 to 0.10%, Ag: 0 to 0.10%, Be: 0 ˜0.15%, REM (rare earth element): 0 to 0.10%, consisting of the balance Cu and unavoidable impurities, having a chemical composition satisfying the following formula (1), and existing in the parent phase Among the second phase particles, the number density of “ultrafine second phase particles” having a particle diameter of 3 nm to 10 nm is 1.0 × 10 ⁹ particles / mm ² or more, and the following formulas (2) and (3) It meets X-ray diffraction intensity ratio of the rolling direction 0.2% proof stress above 900 MPa, and a conductivity of 35% IACS or more, a high strength copper alloy sheet material in which the plate thickness is 20 to 60 [mu] m.
3.5 ≦ (Ni + Co) /Si≦5.0 (1)
Here, the content value (% by mass) of the element is substituted for the element symbol in the formula (1).
I {200} / (I {111} + I {220} + I {311}) ≧ 0.50 (2)
I {220} / (I {111} + I {200} + I {311}) ≦ 0.75 (3)
Here, I {hkl} is the integrated intensity of the X-ray diffraction peak of the {hkl} crystal plane on the copper alloy sheet. 粒子径５００ｎｍ以上２０００ｎｍ以下の「粗大第二相粒子」の個数密度が１.０×１０⁴個／ｍｍ²以上である請求項１に記載の高強度銅合金薄板材。 ^2. The high-strength copper alloy sheet material according to claim 1, wherein the number density of “coarse second phase particles” having a particle diameter of 500 nm or more and 2000 nm or less is 1.0 × 10 ⁴ particles / mm ² or more. 質量％で、ＮｉとＣｏの合計：２.５０〜５.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.１０％、Ｃｒ：０〜０.１０％、Ｍｇ：０〜０.１０％、Ｍｎ：０〜０.１０％、Ｔｉ：０〜０.３０％、Ｖ：０〜０.２０％、Ｚｒ：０〜０.１５％、Ｓｎ：０〜０.１０％、Ｚｎ：０〜０.１５％、Ａｌ：０〜０.２０％、Ｂ：０〜０.０２％、Ｐ：０〜０.１０％、Ａｇ：０〜０.１０％、Ｂｅ：０〜０.１５％、ＲＥＭ（希土類元素）：０〜０.１０％であり、残部Ｃｕおよび不可避的不純物からなり、かつ下記（１）式を満たす化学組成を有する銅合金鋳片に対して、圧延終了温度６５０℃以上、６５０℃から３００℃までの平均冷却速度が１０℃／ｓｅｃ以上の条件で熱間圧延を施す工程、
８００℃から９５０℃までの平均昇温速度を５０℃／ｓｅｃ以上とし、９５０〜１０２０℃の範囲で５〜３００ｓｅｃ保持して第二相粒子を固溶させ、９５０℃から６５０℃までの平均冷却速度を１０〜３０℃／ｓｅｃとする条件で溶体化処理を施す工程、
前記溶体化処理後の材料または前記溶体化処理後に圧延率５０％以下の冷間圧延を施した材料に対して、時効処理後の圧延方向引張強さＴＳ(age)（ＭＰａ）および導電率ＥＣ(age)（％ＩＡＣＳ）がそれぞれ下記（４）式および（５）式を満たす条件で時効処理を施す工程、
前記時効処理後の組織状態を有する材料に対して、圧延率２０〜９０％の範囲で仕上冷間圧延を施して板厚２０〜６０μｍとする工程、
を有する請求項１または２に記載の高強度銅合金薄板材の製造方法。
３.５≦（Ｎｉ＋Ｃｏ）／Ｓｉ≦５.０ …（１）
ここで、（１）式の元素記号の箇所には当該元素の含有量値（質量％）が代入される。
０.９０≦ＴＳ(age)／ＴＳ(max)≦０.９７ …（４）
１.０５≦ＥＣ(age)／ＥＣ(tsmax)≦１.２０ …（５）
ここで、ＴＳ(max)は、前記溶体化処理後の当該材料に対して、３５０℃から６００℃までの１０℃刻みの各温度で６ｈ保持する時効処理を施したときに得られる圧延方向最大引張強さ（ＭＰａ）であり、ＥＣ(tsmax)は、前記ＴＳ(max)が得られた試料における導電率（％ＩＡＣＳ）である。 In mass%, the total of Ni and Co: 2.50 to 5.00%, Si: 0.50 to 1.50%, Fe: 0 to 0.10%, Cr: 0 to 0.10%, Mg: 0 to 0.10%, Mn: 0 to 0.10%, Ti: 0 to 0.30%, V: 0 to 0.20%, Zr: 0 to 0.15%, Sn: 0 to 0.10 %, Zn: 0 to 0.15%, Al: 0 to 0.20%, B: 0 to 0.02%, P: 0 to 0.10%, Ag: 0 to 0.10%, Be: 0 ~ 0.15%, REM (rare earth element): 0 to 0.10%, consisting of the balance Cu and inevitable impurities, and a copper alloy slab having a chemical composition satisfying the following formula (1): Rolling end temperature 650 ° C. or higher, a step of performing hot rolling under conditions where the average cooling rate from 650 ° C. to 300 ° C. is 10 ° C./sec or more,
The average temperature increase rate from 800 ° C. to 950 ° C. is set to 50 ° C./sec or more, and the second phase particles are dissolved in the range of 950 to 1020 ° C. for 5 to 300 seconds, and the average cooling from 950 ° C. to 650 ° C. A step of applying a solution treatment under a condition of a speed of 10 to 30 ° C./sec,
With respect to the material after the solution treatment or the material subjected to the cold rolling with a rolling rate of 50% or less after the solution treatment, the tensile strength TS (age) (MPa) in the rolling direction after the aging treatment and the conductivity EC (age) (% IACS) is a process of performing an aging treatment under conditions satisfying the following formulas (4) and (5), respectively:
A step of subjecting the material having a textured state after the aging treatment to finish cold rolling in a range of a rolling rate of 20 to 90% to a plate thickness of 20 to 60 μm;
The manufacturing method of the high intensity | strength copper alloy sheet material of Claim 1 or 2 which has these.
3.5 ≦ (Ni + Co) /Si≦5.0 (1)
Here, the content value (% by mass) of the element is substituted for the element symbol in the formula (1).
0.90 ≦ TS (age) / TS (max) ≦ 0.97 (4)
1.05 ≦ EC (age) / EC (tsmax) ≦ 1.20 (5)
Here, TS (max) is the maximum in the rolling direction obtained when the material after the solution treatment is subjected to an aging treatment for 6 hours at each temperature of 10 ° C. from 350 ° C. to 600 ° C. It is the tensile strength (MPa), and EC (tsmax) is the electrical conductivity (% IACS) in the sample from which the TS (max) was obtained. さらに、前記仕上冷間圧延後の材料に対して、加熱温度１５０〜５５０℃の低温焼鈍を施す工程を有する、請求項３に記載の高強度銅合金薄板材の製造方法。 Furthermore, the manufacturing method of the high intensity | strength copper alloy sheet material of Claim 3 which has the process of giving the low temperature annealing of the heating temperature 150-550 degreeC with respect to the material after the said finish cold rolling. 請求項１または２に記載の銅合金薄板材を使用して作製した電気・電子部品。 Electrical and electronic parts prepared using a copper alloy sheet material according to claim 1 or 2.