JP6788471B2 - Cu-Ni-Co-Si based copper alloy thin plate material and manufacturing method and conductive member - Google Patents

Description

本発明は、幅の狭い高精度なフォトエッチング加工に適したＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金薄板材、およびその製造方法、並びにその銅合金薄板材を使用した導電部材に関する。 The present invention relates to a Cu—Ni—Co—Si based copper alloy thin plate material suitable for narrow and high-precision photoetching, a method for producing the same, and a conductive member using the copper alloy thin plate material.

コネクタ等の導電ばね部材の小型化に伴い、寸法精度の高いエッチング加工が可能な高強度銅合金の薄板材が求められている。高精度のエッチング加工を施すためには、できるだけ表面凹凸の少ない（表面平滑性の良好な）エッチング加工面が得られる材料を適用する必要がある。しかし、板厚が６０μｍ以下の極薄の高強度銅合金板材では、集合組織の影響により、平滑性に優れるエッチング加工面を実現することが難しい。以下、本明細書では、平滑性に優れるエッチング加工表面が得られる特性のことを「エッチング加工性」という。 With the miniaturization of conductive spring members such as connectors, there is a demand for a thin plate material of high-strength copper alloy that can be etched with high dimensional accuracy. In order to perform high-precision etching, it is necessary to apply a material that can obtain an etched surface with as few surface irregularities as possible (good surface smoothness). However, in an ultrathin high-strength copper alloy plate material having a plate thickness of 60 μm or less, it is difficult to realize an etched surface having excellent smoothness due to the influence of the texture. Hereinafter, in the present specification, the property of obtaining an etched surface having excellent smoothness is referred to as "etchability".

特許文献１には、Ｃｕｂｅ方位｛００１｝＜１００＞の配向性を高めて曲げ加工性や疲労特性を改善した板厚０.０３〜０.５ｍｍのＣｕ−Ｎｉ−Ｓｉ系銅合金板材が開示されている。しかし、極薄材でのエッチング性の改善については考慮されていない。上記の結晶配向では、極薄板材で優れたエッチング加工性を実現することは難しい。 Patent Document 1 discloses a Cu—Ni—Si copper alloy plate material having a plate thickness of 0.03 to 0.5 mm, which has improved bending workability and fatigue characteristics by enhancing the orientation of the Cube orientation {001} <100>. Has been done. However, no consideration is given to improving the etchability of ultrathin materials. With the above crystal orientation, it is difficult to realize excellent etching processability with an ultrathin plate material.

特許文献２には、圧延集合組織である（２２０）面の存在比率を低減した結晶配向（段落００６７参照）により曲げ加工性や応力緩和特性を改善した板厚０.０１〜２.０ｍｍのＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金板材が開示されている。しかし、その結晶配向では、極薄材で優れたエッチング加工性を実現することは難しい。 Patent Document 2 describes Cu with a plate thickness of 0.01 to 2.0 mm in which bending workability and stress relaxation characteristics are improved by crystal orientation (see paragraph 0067) in which the abundance ratio of the (220) plane, which is a rolled texture, is reduced. A −Ni—Co—Si based copper alloy plate material is disclosed. However, with the crystal orientation, it is difficult to realize excellent etching processability with an ultrathin material.

特許文献３には、Ｂｒａｓｓ方位などの特定の方位が突出していない、つまり方位密度が小さい状態（段落００２１参照）として、曲げ加工性の改善を図ったＣｕ−Ｎｉ−Ｓｉ系銅合金板材が開示されている。しかし、そのような結晶配向では、極薄板材で優れたエッチング加工性を実現することは難しい。 Patent Document 3 discloses a Cu—Ni—Si-based copper alloy plate material with improved bending workability in a state where a specific orientation such as a Brass orientation does not protrude, that is, the orientation density is low (see paragraph 0021). Has been done. However, with such crystal orientation, it is difficult to realize excellent etching processability with an ultrathin plate material.

特開２０１３−１６３８５３号公報Japanese Unexamined Patent Publication No. 2013-163853 特開２０１６−４４３４４号公報Japanese Unexamined Patent Publication No. 2016-44344 特開２０１３−８２９６８号公報Japanese Unexamined Patent Publication No. 2013-82968

本発明は、高強度Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金の極薄板材において、優れたエッチング加工性を有するもの（すなわち平滑性に優れるエッチング加工面が得られるもの）を提供することを、第１の目的とする。また、薄肉化された導電ばね部材として優れたばね特性や耐久性を発揮させるためには、極めて高強度であることが有利となる。したがって、優れたエッチング加工性と、極めて高い強度との両立を図ることを、第２の目的とする。さらに、条材から「切り板」を採取した場合に、その切り板の平坦性が良好であるほど、導電部材の寸法精度を高めるうえで有利となる。したがって、優れたエッチング加工性と、平坦性に優れる板形状の実現との両立を図ることを、第３の目的とする。 The present invention provides an ultrathin plate material of a high-strength Cu—Ni—Co—Si based copper alloy, which has excellent etching processability (that is, one which can obtain an etched surface having excellent smoothness). The first purpose is. Further, in order to exhibit excellent spring characteristics and durability as a thin conductive spring member, it is advantageous to have extremely high strength. Therefore, the second purpose is to achieve both excellent etching processability and extremely high strength. Further, when a "cut plate" is collected from a strip, the better the flatness of the cut plate, the more advantageous it is in improving the dimensional accuracy of the conductive member. Therefore, it is a third object to achieve both excellent etching processability and realization of a plate shape having excellent flatness.

発明者らの研究によれば、以下のことがわかった。
（ａ）板厚６０μｍ以下の極薄のＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金板材の場合、Ｂｒａｓｓ方位｛０１１｝＜２１１＞の結晶配向を高めることが、優れたエッチング加工性の実現に極めて有効である。
（ｂ）非常に高い｛０１１｝＜２１１＞結晶配向を有する極薄のＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金板材を実現するためには、（i）仕上冷間圧延において、少なくとも初期段階で１パスあたりの圧下率を十分に確保するとともにトータル圧延率を９０％以上とすること、（ii）仕上圧延後に行う低温焼鈍において、高めの張力を付与しながら３５０℃以下の温度で十分な保持を行うこと、が極めて有効である。
（ｃ）微細な第二相粒子が十分に分散させて、０.２％耐力が１０００ＭＰａ以上という非常に高い強度レベルを極薄板材で実現するためには、（i）Ｎｉ、Ｃｏ、Ｓｉの含有量を適正化すること、（ii）熱間圧延前の鋳片加熱において、１０００℃以上で十分保持すること、（iii）溶体化処理において、適正温度で保持した後、冷却過程で所定温度域での滞在時間を十分に確保するヒートパターンを採用すること、（iv）時効処理を３００〜４００℃という低めの温度で十分に行うこと、（v）低温焼鈍の温度・時間が過度にならないように管理すること、が極めて有効であり、上記の優れたエッチング加工性との両立が可能である。
（ｄ）平坦性に優れる板形状を極薄板材で実現するためには、（i）仕上冷間圧延において、例えば直径４０ｍｍ以上といった比較的大径のワークロールを使用して所定の極薄板厚まで冷間圧延すること、（ii）低温焼鈍において、加熱保持時間を十分に確保するとともに、昇温速度・冷却速度が過大にならないように管理すること、が極めて有効であり、上記の優れたエッチング加工性との両立が可能である。
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。 According to the research of the inventors, the following was found.
(A) In the case of an ultrathin Cu—Ni—Co—Si copper alloy plate having a plate thickness of 60 μm or less, increasing the crystal orientation of the Brass orientation {011} <211> is extremely effective in achieving excellent etching processability. It is valid.
(B) In order to realize an ultrathin Cu—Ni—Co—Si copper alloy plate having a very high {011} <211> crystal orientation, (i) in the finish cold rolling, at least at the initial stage. Sufficient rolling reduction per pass should be ensured and the total rolling ratio should be 90% or more. (Ii) In low-temperature annealing performed after finish rolling, sufficient tension is applied and sufficiently maintained at a temperature of 350 ° C or lower. Is extremely effective.
(C) In order to sufficiently disperse fine second-phase particles and realize a very high strength level of 0.2% proof stress of 1000 MPa or more with an ultrathin plate material, (i) Ni, Co, Si To optimize the content, (ii) keep the slab at 1000 ° C or higher in the slab heating before hot rolling, (iii) keep it at the proper temperature in the solution treatment, and then set the temperature in the cooling process. Adopt a heat pattern that secures a sufficient staying time in the region, (iv) sufficiently perform the aging treatment at a low temperature of 300 to 400 ° C, and (v) do not make the temperature and time of low-temperature annealing excessive. It is extremely effective to manage in such a manner, and it is possible to achieve both the above-mentioned excellent etching processability.
(D) In order to realize a plate shape with excellent flatness with an ultra-thin plate material, (i) in finish cold rolling, a relatively large-diameter work roll having a diameter of 40 mm or more is used to obtain a predetermined ultra-thin plate thickness. It is extremely effective to perform cold rolling until (ii) to secure a sufficient heating and holding time in low-temperature annealing and to control the heating and cooling rates so as not to become excessive. It is possible to achieve both etching processability.
The present invention has been completed based on such findings.

すなわち本発明では、質量％で、ＮｉとＣｏの合計：２.５０〜４.００％、Ｃｏ：０.５０〜２.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.５０％、Ｍｇ：０〜０.１０％、Ｓｎ：０〜０.５０％、Ｚｎ：０〜０.１５％、Ｂ：０〜０.１０％、Ｐ：０〜０.１０％、ＲＥＭ（希土類元素）：０〜０.１０％、Ｃｒ、Ｚｒ、Ｈｆ、Ｎｂ、Ｓの合計：０〜０.０５％、残部Ｃｕおよび不可避的不純物からなる化学組成を有し、ＥＢＳＤ（電子線後方散乱回折）法により、展開次数１６、ガウス分布近似の半値幅５°として調和関数法で求めた方位分布関数（ＯＤＦ）を用いて、完全ランダム方位分布に対する強度比として特定されるＢｒａｓｓ方位｛０１１｝＜２１１＞の集積度が５.００以上である結晶配向を有する、板厚１０〜６０μｍの銅合金薄板材が提供される。 That is, in the present invention, in terms of mass%, the total of Ni and Co: 2.50 to 4.00%, Co: 0.50 to 2.00%, Si: 0.50 to 1.50%, Fe: 0 to 0. 0.50%, Mg: 0-0.10%, Sn: 0-0.50%, Zn: 0-0.15%, B: 0-0.10%, P: 0-0.10%, REM (rare earth element): 0 to 0.10%, total of Cr, Zr, Hf, Nb, S: 0 to 0.05%, having a chemical composition consisting of the balance Cu and unavoidable impurities, EBSD (electron backscatter diffraction) The Brass orientation {specified as the intensity ratio to the completely random orientation distribution using the orientation distribution function (ODF) obtained by the harmonic function method with an unfolded order of 16 and a half-value width of 5 ° of the Gaussian distribution approximation by the backscatter diffraction) method. A copper alloy thin plate material having a plate thickness of 10 to 60 μm and having a crystal orientation in which the degree of integration of 011} <211> is 5.00 or more is provided.

上記元素のうち、Ｃｕ、Ｎｉ、Ｃｏ、Ｓｉ以外の元素は任意含有元素である。Ｎｉの含有量範囲は、Ｃｏ含有量との関係から０.５０〜３.５０％となる。Ｙも希土類元素として扱う。 Among the above elements, elements other than Cu, Ni, Co, and Si are optional contained elements. The Ni content range is 0.50 to 3.50% in relation to the Co content. Y is also treated as a rare earth element.

Ｂｒａｓｓ方位は、面心立方格子の結晶において、｛０１１｝面が圧延面に平行で且つ＜２１１＞方向が圧延方向に平行な結晶の方位である。上記「集積度」は以下のようにして求められる。 The Brass orientation is the orientation of the crystal in a face-centered cubic lattice in which the {011} plane is parallel to the rolling plane and the <211> direction is parallel to the rolling direction. The above "integration degree" is obtained as follows.

〔｛０１１｝＜２１１＞集積度の求め方〕
板面（圧延面）をバフ研磨およびイオンミリングにより調製した観察面（圧延面からの除去深さが板厚の１／１０）をＦＥ−ＳＥＭ（電界放出形走査電子顕微鏡）により観察し、５０μｍ×５０μｍの測定領域について、ＥＢＳＤ（電子線後方散乱回折）法により測定ピッチ０.２μｍにて結晶方位を測定し、展開次数１６、ガウス分布近似の半値幅５°として調和関数法で展開した方位分布関数（ＯＤＦ）に基づくＩｎｔｅｎｓｉｔｙ Ｐｌｏｔから、Ｂｒａｓｓ方位｛０１１｝＜２１１＞の強度を求める。その強度が、完全ランダム（全ての方位が等しく現れる状態）の強度を１として何倍の強度であるかを示す数値を定め、その数値を｛０１１｝＜２１１＞集積度とする。 [{011} <211> How to obtain the degree of integration]
The observation surface (the removal depth from the rolled surface is 1/10 of the plate thickness) prepared by buffing and ion milling the plate surface (rolled surface) was observed by FE-SEM (field emission scanning electron microscope), and 50 μm. For the measurement region of × 50 μm, the crystal orientation was measured at a measurement pitch of 0.2 μm by the EBSD (electron backscatter diffraction) method, and the orientation developed by the harmonic function method with a development order of 16 and a half-value width of 5 ° of the Gaussian distribution approximation. The intensity of the Brass orientation {011} <211> is obtained from the Integrity Plot based on the distribution function (ODF). A numerical value indicating how many times the intensity is, with the intensity of completely random (a state in which all directions appear equally) as 1, is defined, and the numerical value is defined as {011} <211> degree of integration.

上記板材において特に、圧延方向の０.２％耐力が例えば１０００Ｍｐａ以上といった非常に強度レベルの高いものとして、マトリックス（金属素地）中に存在する粒子径５〜１０ｎｍの微細第二相粒子の個数密度が１.０×１０⁹個／ｍｍ²以上である金属組織を有するものが提供される。「第二相」はマトリックス中に存在する化合物相である。主に(Ｎｉ,Ｃｏ)₂Ｓｉを主体とする化合物相が挙げられる。微細第二相粒子個数密度は以下のようにして求めることができる。 In particular, in the above plate material, the number density of fine second-phase particles having a particle diameter of 5 to 10 nm existing in the matrix (metal base) is assumed to have a very high strength level such as a 0.2% proof stress in the rolling direction of 1000 Mpa or more. Those having a metallographic structure of 1.0 × 10 ⁹ pieces / mm ² or more are provided. The "second phase" is the compound phase present in the matrix. The compound phase mainly composed of (Ni, Co) ₂ Si can be mentioned. The number density of fine second phase particles can be obtained as follows.

〔微細第二相粒子の個数密度の求め方〕
測定対象である板材から採取した試料をＴＥＭ（透過型電子顕微鏡）で観察し、観察視野中に確認できる粒子径５〜１０ｎｍの第二相粒子の個数をカウントする。観察視野は無作為に選択した１つまたは複数の視野とし、観察領域の総面積が５.０×１０^-3ｍｍ²以上となるようにする。粒子径は粒子を取り囲む最小円の直径とする。粒子径５〜１０ｎｍの第二相粒子のカウント総数を観察領域の総面積で除した値（個／ｍｍ²）を微細第二相粒子の個数密度とする。 [How to find the number density of fine second phase particles]
A sample collected from the plate material to be measured is observed with a TEM (transmission electron microscope), and the number of second-phase particles having a particle diameter of 5 to 10 nm that can be confirmed in the observation field is counted. The observation field of view shall be one or more randomly selected fields of view so that the total area of the observation area is 5.0 × 10 ^-3 mm ² or more. The particle diameter is the diameter of the smallest circle surrounding the particle. The value obtained by dividing the total number of counts of the second phase particles having a particle diameter of 5 to 10 nm by the total area of the observation region (pieces / mm ² ) is defined as the number density of the fine second phase particles.

上記板材において特に、平坦性に優れるものとして、下記（Ａ）に定義する最大クロスボウｑ_MAXが２５０μｍ以下であるもの、および下記（Ｂ）に定義するＩ−ｕｎｉｔが５.０以下であるものが提供される。 Among the above-mentioned plate materials, those having a maximum crossbow q _MAX of 250 μm or less defined in the following (A) and those having an I-unit defined in the following (B) of 5.0 or less are particularly excellent in flatness. Provided.

（Ａ）当該銅合金板材から圧延方向長さが５０ｍｍ、圧延直角方向長さが板幅Ｗ₀（ｍｍ）である長方形の切り板Ｐを採取し、その切り板Ｐをさらに圧延直角方向５０ｍｍピッチで裁断し、その際、圧延直角方向長さが５０ｍｍに満たない小片が切り板Ｐの圧延直角方向端部に発生したときはその小片を除き、ｎ個（ｎは板幅Ｗ₀／５０の整数部分）の５０ｍｍ角の正方形サンプルを用意する。各正方形サンプルごとに、日本伸銅協会技術規格ＪＣＢＡ Ｔ３２０：２００３に規定の三次元測定装置による測定方法（ただし、ｗ＝５０ｍｍとする）に従い、水平盤上に置いたときのクロスボウｑを、両面（両側の板面）について圧延直角方向に測定し、各面のｑの絶対値｜ｑ｜の最大値を当該正方形サンプルのクロスボウｑ_i（ｉは１〜ｎ）とする。ｎ個の正方形サンプルのクロスボウｑ₁〜ｑ_nのうちの最大値を最大クロスボウｑ_MAXとする。 (A) A rectangular cut plate P having a rolling direction length of 50 mm and a rolling perpendicular direction length of plate width W ₀ (mm) is collected from the copper alloy plate material, and the cut plate P is further rolled at a pitch of 50 mm in the rolling perpendicular direction. At that time, if small pieces with a length of less than 50 mm in the rolling perpendicular direction are generated at the end of the cutting plate P in the rolling perpendicular direction, the small pieces are removed and n pieces (n is the plate width W _0/50 ). Prepare a 50 mm square square sample (the integer part). For each square sample, the crossbow q when placed on a horizontal plate is placed on both sides according to the measurement method (however, w = 50 mm) by the three-dimensional measuring device specified in the Japan Copper and Rolling Association technical standard JCBA T320: 2003. (Plate surfaces on both sides) are measured in the direction perpendicular to rolling, and the maximum value of the absolute value | q | of q on each surface is defined as the crossbow q _i (i is 1 to n) of the square sample. Let the maximum value of the crossbows q _{1 to} q _n of _n square samples be the maximum crossbow q _MAX .

（Ｂ）当該銅合金板材から圧延方向長さが４００ｍｍであり、圧延直角方向長さが板幅Ｗ₀（ｍｍ）である長方形の切り板Ｑを採取し、水平盤上に置く。切り板Ｑを鉛直方向に見た投影表面（以下、単に「投影表面」という）の中に圧延方向長さ４００ｍｍ、圧延直角方向長さＷ₀の長方形領域Ｘを定め、その長方形領域Ｘをさらに圧延直角方向１０ｍｍピッチで短冊状領域に分割し、その際、圧延直角方向長さが１０ｍｍに満たない狭幅の短冊状領域が長方形領域Ｘの圧延直角方向端部に発生したときはその狭幅の短冊状領域を除き、隣接するｎ箇所（ｎは板幅Ｗ₀／１０の整数部分）の短冊状領域（長さ４００ｍｍ、幅１０ｍｍ）を設定する。各短冊状領域ごとに、幅中央部の表面高さを圧延方向長さ４００ｍｍにわたって測定し、最大高さｈ_MAXと最小高さｈ_MINの差ｈ_MAX−ｈ_MINの値を波高さｈとし、下記（１）式により求まる伸び差率ｅを当該短冊状領域の伸び差率ｅ_i（ｉは１〜ｎ）とする。ｎ箇所の短冊状領域の伸び差率ｅ₁〜ｅ_nのうちの最大値をＩ−ｕｎｉｔとする。
ｅ＝（π／２×ｈ／Ｌ）² …（１）
ただし、Ｌは基準長さ４００ｍｍ (B) A rectangular cutting plate Q having a rolling direction length of 400 mm and a rolling perpendicular direction length of plate width W ₀ (mm) is collected from the copper alloy plate material and placed on a horizontal plate. A rectangular region X having a rolling direction length of 400 mm and a rolling perpendicular direction length W ₀ is defined in a projected surface (hereinafter, simply referred to as “projected surface”) when the cut plate Q is viewed in the vertical direction, and the rectangular region X is further defined. It is divided into strip-shaped regions at a pitch of 10 mm in the rolling perpendicular direction, and at that time, when a narrow strip-shaped region having a length in the rolling perpendicular direction of less than 10 mm occurs at the end of the rectangular region X in the rolling perpendicular direction, the narrow width the exception of the strip-shaped region, strip-like region (length 400 mm, width 10 mm) of the adjacent n points (n is an integer portion of the plate width W _0/10) to set the. For each strip-shaped region, the surface height at the center of the width was measured over a length of 400 mm in the rolling direction, and the difference between the maximum height h _MAX and the minimum height h _MIN h _MAX −h _MIN was defined as the wave height h. The elongation difference rate e obtained by the following equation (1) is defined as the elongation difference rate e _i (i is 1 to n) in the strip-shaped region. The maximum value of the differential expansion rate e ₁ to e _n strip-shaped region of the n locations to I-Unit.
e = (π / 2 × h / L) ² … (1)
However, L has a standard length of 400 mm.

また、上記のエッチング加工性に優れた銅合金薄板材の製造方法として、質量％で、ＮｉとＣｏの合計：２.５０〜４.００％、Ｃｏ：０.５０〜２.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.５０％、Ｍｇ：０〜０.１０％、Ｓｎ：０〜０.５０％、Ｚｎ：０〜０.１５％、Ｂ：０〜０.１０％、Ｐ：０〜０.１０％、ＲＥＭ（希土類元素）：０〜０.１０％、Ｃｒ、Ｚｒ、Ｈｆ、Ｎｂ、Ｓの合計：０〜０.０５％、残部Ｃｕおよび不可避的不純物からなる化学組成を有する鋳片を製造し、鋳片加熱、熱間圧延、冷間圧延、溶体化処理、時効処理、仕上冷間圧延、低温焼鈍の各工程を上記の順に有する手順で板厚１０〜６０μｍの銅合金薄板材を製造するに際し、
仕上冷間圧延工程において、直径３５〜５０ｍｍのワークロールを使用し、少なくとも圧延率が５０％未満である段階で開始する圧延パスでは１パス当たりの圧下率を１０.０％以上とし、かつトータル圧延率を９０％以上とする条件で冷間圧延を施し、
低温焼鈍工程において、１８０〜２２０Ｎ／ｍｍ²の張力を付与しながら２５０〜３５０℃で１５０秒以上保持する条件で熱処理を施す、銅合金薄板材の製造方法が提供される。 Further, as a method for producing the copper alloy thin plate material having excellent etching processability, the total of Ni and Co: 2.50 to 4.00%, Co: 0.50 to 2.00%, Si in mass%. : 0.50 to 1.50%, Fe: 0 to 0.50%, Mg: 0 to 0.10%, Sn: 0 to 0.50%, Zn: 0 to 0.15%, B: 0 to 0 0.10%, P: 0-0.10%, REM (rare earth element): 0-0.10%, total of Cr, Zr, Hf, Nb, S: 0-0.05%, balance Cu and inevitable A procedure in which a slab having a chemical composition composed of target impurities is produced, and each step of slab heating, hot rolling, cold rolling, solution treatment, aging treatment, finish cold rolling, and low temperature annealing is performed in the above order. In manufacturing a copper alloy thin plate material with a plate thickness of 10 to 60 μm,
In the finishing cold rolling process, a work roll with a diameter of 35 to 50 mm is used, and in a rolling pass that starts at a stage where the rolling ratio is at least less than 50%, the rolling reduction rate per pass is set to 10.0% or more, and the total Cold rolling is performed under the condition that the rolling ratio is 90% or more.
Provided is a method for producing a thin copper alloy plate, which is subjected to heat treatment in a low temperature annealing step under the condition of holding at 250 to 350 ° C. for 150 seconds or more while applying a tension of 180 to 220 N / mm ² .

ある板厚ｔ₀（ｍｍ）からある板厚ｔ₁（ｍｍ）までの圧延率は、下記（２）式により求まる。
圧延率（％）＝（ｔ₀−ｔ₁）／ｔ₀×１００ …（２）
ある圧延パスにおける１パスでの圧延率を本明細書では特に「圧下率」と呼んでいる。 The rolling ratio from a certain plate thickness t ₀ (mm) to a certain plate thickness t ₁ (mm) can be obtained by the following equation (2).
Rolling rate (%) = (t ₀ −t ₁ ) / t ₀ × 100… (2)
In this specification, the rolling rate in one rolling path in a certain rolling pass is particularly referred to as "rolling rate".

特に、圧延方向の０.２％耐力が１０００ＭＰａ以上という高強度と、最大クロスボウｑ_MAXが２５０μｍ以下、Ｉ−ｕｎｉｔが５.０以下という平坦性の高い板形状を実現するための製造方法として、以下の手法を採用することができる。
上記の化学組成を有する鋳片を製造し、鋳片加熱、熱間圧延、冷間圧延、溶体化処理、時効処理、仕上冷間圧延、低温焼鈍の各工程を上記の順に有する手順で板厚１０〜６０μｍの銅合金薄板材を製造するに際し、
鋳片加熱工程において、鋳片を１０００〜１０６０℃で２時間以上保持し、
溶体化処理工程において、９５０〜１０２０℃で０.５〜１０分保持した後、６００〜７９０℃の温度範囲に１５〜３００秒保持するヒートパターンを採用し、
時効処理工程において、時効温度を３００〜４００℃の範囲とし、
仕上冷間圧延工程において、直径３５〜５０ｍｍのワークロールを使用し、少なくとも圧延率が５０％未満である段階で開始する圧延パスでは１パス当たりの圧下率を１０.０％以上とし、かつトータル圧延率を９０％以上とする条件で冷間圧延を施し、
低温焼鈍工程において、１８０〜２２０Ｎ／ｍｍ²の張力を付与しながら２９０〜３５０℃で１５０〜７２０秒保持するとともに、前記保持温度までの昇温過程において最大昇温速度を７０℃／ｓ以下とし、かつ前記保持温度からの降温過程において最大冷却速度を７０℃／ｓ以下とする条件で熱処理を施す、銅合金薄板材の製造方法。 In particular, as a manufacturing method for realizing a high strength with a 0.2% proof stress in the rolling direction of 1000 MPa or more, a maximum crossbow q _MAX of 250 μm or less, and an I-unit of 5.0 or less, which is highly flat. The following methods can be adopted.
A slab having the above chemical composition is produced, and the plate thickness is obtained by the procedure of slab heating, hot rolling, cold rolling, solution treatment, aging treatment, finish cold rolling, and low temperature annealing in the above order. In manufacturing a copper alloy thin plate material of 10 to 60 μm,
In the slab heating step, the slab is held at 1000-1060 ° C. for 2 hours or more.
In the solution treatment step, a heat pattern was adopted in which the mixture was held at 950 to 1020 ° C. for 0.5 to 10 minutes and then held in the temperature range of 600 to 790 ° C. for 15 to 300 seconds.
In the aging treatment step, the aging temperature is set in the range of 300 to 400 ° C.
In the finishing cold rolling process, a work roll with a diameter of 35 to 50 mm is used, and in a rolling pass that starts at a stage where the rolling ratio is at least less than 50%, the rolling reduction rate per pass is set to 10.0% or more, and the total Cold rolling is performed under the condition that the rolling ratio is 90% or more.
In the low temperature annealing step, the temperature is maintained at 290 to 350 ° C. for 150 to 720 seconds while applying a tension of 180 to 220 N / mm ² , and the maximum heating rate is set to 70 ° C./s or less in the heating process up to the holding temperature. A method for producing a thin copper alloy plate, which is subjected to heat treatment under the condition that the maximum cooling rate is 70 ° C./s or less in the process of lowering the temperature from the holding temperature.

本発明によれば、Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金の極薄板材において、エッチング加工面の表面平滑性に優れるものが実現できた。この極薄板材は、寸法精度の高い薄肉導電部品の素材として有用である。そのような優れたエッチング加工性を有する極薄板材において、０.２％耐力が１０００ＭＰａ以上という強度レベルを得ることが可能である。また、極薄板材でありながら、極めて平坦性の高い切り板を採取することも可能である。 According to the present invention, in an ultrathin plate material of Cu-Ni-Co-Si based copper alloy, a material having excellent surface smoothness on an etched surface can be realized. This ultra-thin plate material is useful as a material for thin-walled conductive parts with high dimensional accuracy. In an ultrathin plate material having such excellent etching processability, it is possible to obtain a strength level of 0.2% proof stress of 1000 MPa or more. It is also possible to collect a cut plate with extremely high flatness, even though it is an ultra-thin plate material.

〔化学組成〕
本発明では、Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金を採用する。以下、合金成分に関する「％」は、特に断らない限り「質量％」を意味する。 [Chemical composition]
In the present invention, a Cu—Ni—Co—Si based copper alloy is adopted. Hereinafter, "%" regarding the alloy component means "mass%" unless otherwise specified.

ＮｉおよびＣｏは、Ｎｉ−Ｓｉ系化合物あるいはＣｏ−Ｓｉ系化合物（以下、これらをまとめて「Ｎｉ−Ｃｏ−Ｓｉ系化合物」と呼ぶことがある。）を形成し、銅合金板材の強度と導電性を向上させる。その析出物は主として(Ｎｉ,Ｃｏ)₂Ｓｉであると考えられる。この化合物は本明細書でいう「第二相」に該当する。強度向上に有効な微細な析出物粒子を十分に分散させるためには、ＮｉとＣｏの合計含有量を２.５０〜４.００％とする必要がある。このうち、Ｃｏ含有量は０.５０〜２.００％の範囲で調整する。Ｎｉ含有量は０.５０〜３.５０％の範囲で調整することができるが、１.５０〜３.００％の範囲とすることがより好ましい。ＮｉとＣｏの合計含有量が不足すると強度向上効果が小さい。ＮｉとＣｏの合計含有量が多すぎると粗大第二相粒子が生成しやすく、この場合も強度向上効果が不十分となる。 Ni and Co form a Ni-Si-based compound or a Co-Si-based compound (hereinafter, these may be collectively referred to as "Ni-Co-Si-based compound"), and the strength and conductivity of the copper alloy plate material. Improve sex. The precipitate is considered to be mainly (Ni, Co) ₂ Si. This compound corresponds to the "second phase" as used herein. In order to sufficiently disperse the fine precipitate particles effective for improving the strength, the total content of Ni and Co needs to be 2.50 to 4.00%. Of these, the Co content is adjusted in the range of 0.50 to 2.00%. The Ni content can be adjusted in the range of 0.50 to 3.50%, but more preferably in the range of 1.50 to 3.00%. If the total content of Ni and Co is insufficient, the effect of improving the strength is small. If the total content of Ni and Co is too large, coarse second-phase particles are likely to be generated, and in this case as well, the effect of improving the strength is insufficient.

Ｓｉは、Ｎｉ−Ｃｏ−Ｓｉ系化合物を形成する。強度向上に有効な微細な析出物粒子を十分に分散させるために、Ｓｉ含有量を０.５％以上とする。Ｓｉが過剰であると粗大な析出物が生成して、熱間圧延時に割れやすくなる。Ｓｉ含有量は１.５０％以下に制限され、１.２０％以下に管理してもよい。 Si forms a Ni—Co—Si based compound. The Si content is set to 0.5% or more in order to sufficiently disperse the fine precipitate particles effective for improving the strength. If Si is excessive, coarse precipitates are formed and easily cracked during hot rolling. The Si content is limited to 1.50% or less and may be controlled to 1.20% or less.

その他の元素として、必要に応じてＦｅ、Ｍｇ、Ｓｎ、Ｚｎ、Ｂ、Ｐ、ＲＥＭ（希土類元素）、Ｃｒ、Ｚｒ、Ｈｆ、Ｎｂ、Ｓ等を含有させることができる。これらの元素の含有量範囲は、Ｆｅ：０〜０.５０％、Ｍｇ：０〜０.１０％、Ｓｎ：０〜０.５０％、Ｚｎ：０〜０.１５％、Ｂ：０〜０.１０％、Ｐ：０〜０.１０％、ＲＥＭ（希土類元素）：０〜０.１０％、Ｃｒ、Ｚｒ、Ｈｆ、Ｎｂ、Ｓの合計：０〜０.０５％の範囲とする。 As other elements, Fe, Mg, Sn, Zn, B, P, REM (rare earth element), Cr, Zr, Hf, Nb, S and the like can be contained, if necessary. The content range of these elements is Fe: 0 to 0.50%, Mg: 0 to 0.10%, Sn: 0 to 0.50%, Zn: 0 to 0.15%, B: 0 to 0. The range is .10%, P: 0 to 0.10%, REM (rare earth element): 0 to 0.10%, and the total of Cr, Zr, Hf, Nb, and S: 0 to 0.05%.

Ｍｇ、Ｓｎは耐応力緩和性の向上に有効である。Ｂ、Ｐ、Ｃｒ、Ｚｒは合金強度を更に高め、かつ耐応力緩和性の向上に有効である。Ｆｅ、Ｃｒ、Ｚｒは、Ｓなどと高融点化合物を形成しやすく、また、Ｂ、Ｐ、Ｚｒは鋳造組織の微細化効果を有し、熱間加工性の改善に寄与しうる。 Mg and Sn are effective for improving stress relaxation resistance. B, P, Cr and Zr are effective in further increasing the alloy strength and improving the stress relaxation resistance. Fe, Cr, and Zr easily form a refractory compound with S and the like, and B, P, and Zr have the effect of refining the cast structure and can contribute to the improvement of hot workability.

〔結晶配向〕
発明者らの検討によれば、板厚が１０〜６０μｍのＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系極薄板材のエッチング加工性を顕著に高めるには、前掲のＢｒａｓｓ方位｛０１１｝＜２１１＞の集積度が５.００以上という結晶配向とすることが極めて有効であることがわかった。上記集積度が７.００以上であることがより好ましい。過度に高い｛０１１｝＜２１１＞集積度を得る必要はなく、通常１５.００以下、あるいは１３.５０以下の範囲で調整すればよい。従来、低温焼鈍を終えたＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金の極薄板材でＢｒａｓｓ方位への高い配向を得ることは容易ではなかった。しかし、後述のように製造工程に工夫を加えることによって、そのような結晶配向を安定して実現できることが確認された。｛０１１｝＜２１１＞集積度が高いことによるエッチング加工性の向上効果は、特に極薄板材において顕著となる。板厚１０〜６０μｍでエッチング加工性の高い向上効果が認められるが、特に板厚１０μｍ以上５０μｍ未満の範囲では一層高い効果が得られる。 [Crystal orientation]
According to the study by the inventors, in order to remarkably improve the etching processability of the Cu-Ni-Co-Si ultrathin plate material having a plate thickness of 10 to 60 μm, the above-mentioned Brass orientation {011} <211> is integrated. It was found that it is extremely effective to have a crystal orientation with a degree of 5.00 or more. It is more preferable that the degree of integration is 7.00 or more. It is not necessary to obtain an excessively high degree of integration {011} <211>, and it is usually adjusted in the range of 15.00 or less or 13.50 or less. Conventionally, it has not been easy to obtain a high orientation in the Brass direction with an ultrathin plate material of a Cu—Ni—Co—Si based copper alloy that has been annealed at a low temperature. However, it was confirmed that such a crystal orientation can be stably realized by devising the manufacturing process as described later. {011} <211> The effect of improving the etching processability due to the high degree of integration is particularly remarkable in the ultrathin plate material. A high effect of improving etching processability is observed when the plate thickness is 10 to 60 μm, and a higher effect can be obtained particularly in the range of the plate thickness of 10 μm or more and less than 50 μm.

〔微細第二相粒子〕
銅合金においては一般に粒径１０ｎｍ以下の微細析出物は強度向上への寄与が大きいことが知られており、Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系合金では例えば２〜１０ｎｍ程度の析出物の存在密度を十分に確保することで高強度化が可能であるとされる。しかしながら、０.２％耐力が１０００ＭＰａ以上という高レベルの強度を得たい場合には、２〜１０ｎｍ程度の粒子のなかでも特に硬化への寄与が大きい粒子径５〜１０ｎｍの粒子の量を十分に確保することが重要となる。発明者らの詳細な検討によれば、当該微細第二相粒子の存在量は１.０×１０⁹個／ｍｍ²個以上とすることが極めて有効である。１.５×１０⁹個／ｍｍ²個以上とすることがより効果的であり、２.０×１０⁹個／ｍｍ²個以上に管理してもよい。存在量の上限についてはＮｉ、Ｃｏ、Ｓｉの含有量を上述のように規定することによって制限を受けるので特に定める必要はないが、通常、５.０×１０⁹個／ｍｍ²個以下の範囲となる。 [Fine second phase particles]
In copper alloys, it is generally known that fine precipitates having a particle size of 10 nm or less contribute greatly to improving strength, and in Cu—Ni—Co—Si alloys, for example, the abundance density of precipitates having a particle size of about 2 to 10 nm is determined. It is said that high strength can be achieved by securing a sufficient amount. However, when it is desired to obtain a high level of strength with a 0.2% proof stress of 1000 MPa or more, a sufficient amount of particles having a particle diameter of 5 to 10 nm, which has a particularly large contribution to curing, among particles of about 2 to 10 nm. It is important to secure it. According to a detailed study by the inventors, it is extremely effective that the abundance of the fine second-phase particles is 1.0 × 10 ⁹ particles / mm ² or more. It is more effective to set the number to 1.5 × 10 ⁹ pieces / mm ² pieces or more, and the number may be managed to 2.0 × 10 ⁹ pieces / mm ² pieces or more. The upper limit of the abundance is limited by defining the contents of Ni, Co, and Si as described above, so it is not necessary to specify it, but usually it is in the range of 5.0 × 10 ⁹ pieces / mm ² pieces or less. It becomes.

〔板材の形状〕
Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金薄板材の条材から、切り板を採取したときに、その切り板において優れた平坦性が得られるかどうかは、それを加工して得られる精密導電部材の形状（寸法精度）に大きく影響する。種々検討の結果、板材を実際に小片に切断したときに顕在化する圧延直角方向の湾曲（反り）が非常に小さいことが、部品の寸法精度を安定して向上させるために極めて重要である。具体的には板厚が１０〜６０μｍのＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金薄板材において、前記（Ａ）に定義する最大クロスボウｑ_MAXが２５０μｍ以下である場合には、圧延直角方向の板幅Ｗ₀のどの部分に由来する部品においても、薄肉精密導電部品としての寸法精度を安定して高く保つことができる加工性を具備している。最大クロスボウｑ_MAXが２００μｍ以下であることがより好ましく、１５０μｍ以下であることがより好ましい。また、前記（Ｂ）に定義するＩ−ｕｎｉｔが５.０以下であることが好ましく、３.５以下であることが一層好ましい。極薄板材で高い平坦性を確保することは、０.１ｍｍ以上の板厚の板材と比べ、一般に難しい。後述する製造条件の工夫によって、板厚１０〜６０μｍ、あるいは１０μｍ以上５０μｍ未満といったＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金薄板材において、最大クロスボウｑ_MAXとＩ−ｕｎｉｔをそれぞれ上記の範囲内に調整することが可能である。 [Shape shape]
When a cut plate is taken from a strip of Cu-Ni-Co-Si copper alloy thin plate material, whether or not excellent flatness can be obtained in the cut plate is a precision conductive member obtained by processing it. It greatly affects the shape (dimensional accuracy) of. As a result of various studies, it is extremely important that the curvature (warp) in the direction perpendicular to rolling, which becomes apparent when the plate material is actually cut into small pieces, is very small in order to stably improve the dimensional accuracy of the parts. Specifically, in a Cu-Ni-Co-Si copper alloy thin plate material having a plate thickness of 10 to 60 μm, when the maximum crossbow q _MAX defined in (A) above is 250 μm or less, the plate in the direction perpendicular to rolling. A part derived from any part having a width W ₀ has workability that can stably maintain high dimensional accuracy as a thin-walled precision conductive part. The maximum crossbow q _MAX is more preferably 200 μm or less, and more preferably 150 μm or less. Further, the I-unit defined in (B) above is preferably 5.0 or less, and more preferably 3.5 or less. It is generally difficult to secure high flatness with an ultra-thin plate material as compared with a plate material having a plate thickness of 0.1 mm or more. The maximum crossbow q _MAX and I-unit are adjusted within the above ranges for Cu-Ni-Co-Si copper alloy thin plate materials with a plate thickness of 10 to 60 μm or 10 μm or more and less than 50 μm by devising the manufacturing conditions described later. It is possible to do.

〔製造方法〕
以上説明した銅合金薄板材は、例えば以下のような製造工程により作ることができる。
溶解・鋳造→鋳片加熱→熱間圧延→冷間圧延→（中間焼鈍→冷間圧延）→溶体化処理→時効処理→仕上冷間圧延→低温焼鈍
なお、上記工程中には記載していないが、熱間圧延後には必要に応じて面削が行われ、各熱処理後には必要に応じて酸洗、研磨、あるいは更に脱脂が行われる。以下、各工程について説明する。 〔Production method〕
The copper alloy thin plate material described above can be produced, for example, by the following manufacturing process.
Melting / casting → slab heating → hot rolling → cold rolling → (intermediate annealing → cold rolling) → solution heat treatment → aging treatment → finish cold rolling → low temperature annealing Not described in the above process. However, after hot rolling, surface milling is performed as necessary, and after each heat treatment, pickling, polishing, or further degreasing is performed as necessary. Hereinafter, each step will be described.

〔溶解・鋳造〕
連続鋳造、半連続鋳造等により鋳片を製造すればよい。Ｓｉなどの酸化を防止するために、不活性ガス雰囲気または真空溶解炉で行うのがよい。 [Melting / Casting]
The slab may be manufactured by continuous casting, semi-continuous casting, or the like. In order to prevent oxidation of Si and the like, it is preferable to carry out the process in an inert gas atmosphere or a vacuum melting furnace.

〔鋳片加熱〕
熱間圧延前に行う鋳片加熱は、鋳片を１０００〜１０６０℃で２時間以上保持する条件で行うことが好ましい。上記温度での保持時間は、通常、５時間以内の範囲で設定すればよい。保持温度が低い場合や保持時間が短い場合は、鋳片に存在している粗大な第二相の残留量が多くなり、最終的に微細第二相粒子の量が比較的少なくなって０.２％耐力が１０００ＭＰａ以上という非常に高い強度レベルには達しないことがある。保持温度が高すぎると鋳片中の融点が低い部分での強度が低下し、熱間圧延で割れが生じる恐れがある。 [Shard heating]
The slab heating performed before hot rolling is preferably performed under the condition that the slab is held at 1000 to 1060 ° C. for 2 hours or more. The holding time at the above temperature may usually be set within a range of 5 hours or less. When the holding temperature is low or the holding time is short, the residual amount of the coarse second phase present in the slab increases, and finally the amount of fine second phase particles becomes relatively small. The 2% proof stress may not reach a very high strength level of 1000 MPa or more. If the holding temperature is too high, the strength of the slab at a low melting point will decrease, and cracks may occur during hot rolling.

〔熱間圧延〕
上記の鋳片加熱を終えた材料を炉から出して、熱間圧延に供する。熱間圧延は通常の手法に従えばよい。トータルの熱間圧延率は例えば７０〜９７％とすればよい。最終パスの圧延温度は７００℃以上とすることが好ましい。熱間圧延終了後には、水冷などにより急冷することが好ましい。熱間圧延後の板厚は例えば７.０〜２０.０ｍｍである。 [Hot rolling]
The material after heating the slab is taken out of the furnace and subjected to hot rolling. Hot rolling may follow a conventional method. The total hot rolling ratio may be, for example, 70 to 97%. The rolling temperature of the final pass is preferably 700 ° C. or higher. After the completion of hot rolling, it is preferable to quench by water cooling or the like. The plate thickness after hot rolling is, for example, 7.0 to 20.0 mm.

〔冷間圧延〕
冷間圧延により、板厚を減じる。必要に応じて、冷間圧延の途中で中間焼鈍を行うことができる。 [Cold rolling]
The plate thickness is reduced by cold rolling. If necessary, intermediate annealing can be performed during cold rolling.

〔溶体化処理〕
一般に時効処理前には、マトリックスの再結晶化および溶質原子の再固溶化を主目的とする加熱保持が行われる。その冷却過程では、不用意に析出が生じないように常温まで急冷されるのが従来一般的な製法である。この加熱保持とその後の急冷過程を合わせて溶体化処理と呼ぶことが多い。本明細書では、上記の加熱保持の過程を「固溶化処理」と呼ぶ。固溶化処理の保持温度は８００〜１０２０℃の範囲とすることができるが、９５０〜１０２０℃の範囲とすることがより好ましい。保持温度が低いと未固溶の粗大な第二相が残存して、最終的に微細第二相粒子の量が比較的少なくなって０.２％耐力が１０００ＭＰａ以上という非常に高い強度レベルには達しないことがある。保持時間（材料がその温度域にある時間）は例えば０.５〜１０分の範囲で設定することができる。 [Solution treatment]
Generally, before the aging treatment, heat retention is performed for the main purpose of recrystallization of the matrix and resolidification of solute atoms. In the cooling process, a conventional general manufacturing method is to rapidly cool to room temperature so that precipitation does not occur carelessly. This heating retention and the subsequent quenching process are often collectively referred to as solution treatment. In the present specification, the above-mentioned heat holding process is referred to as "solution treatment". The holding temperature of the solution treatment can be in the range of 800 to 1020 ° C., but more preferably in the range of 950 to 1020 ° C. When the holding temperature is low, unsolidified coarse second phase remains, and finally the amount of fine second phase particles becomes relatively small, resulting in a very high strength level of 0.2% proof stress of 1000 MPa or more. May not reach. The holding time (the time the material is in that temperature range) can be set, for example, in the range of 0.5-10 minutes.

圧延方向の０.２％耐力が１０００ＭＰａ以上という極めて高い強度レベルを実現するためには、固溶化処理後に６００〜７９０℃の温度域に所定時間保持する熱履歴を付与することが有効である。この温度域での保持の過程を「前駆処理」と呼ぶ。前駆処理は、固溶化処理後の降温過程を利用して行うことが効率的である。前駆処理を行う場合においては、「固溶化処理」と「前駆処理」を含めた一連の熱処理を便宜上「溶体化処理」と呼んでいる。 In order to realize an extremely high strength level of 0.2% proof stress in the rolling direction of 1000 MPa or more, it is effective to provide a thermal history of holding in a temperature range of 600 to 790 ° C. for a predetermined time after the solution treatment. The process of holding in this temperature range is called "precursor treatment". It is efficient to perform the precursor treatment by utilizing the temperature lowering process after the solution treatment. In the case of performing the precursor treatment, a series of heat treatments including the "solid solution treatment" and the "precursor treatment" are called "solution treatment" for convenience.

Ｃｕ−Ｎｉ−Ｃｏ−Ｓｉ系合金ではＮｉ−Ｓｉ系およびＣｏ−Ｓｉ系の２種類の析出物がそれぞれ高強度化に寄与するが、両者の間で、最適な析出条件（温度や時間）は一致しない（ずれている）。最適な析出温度はＮｉ−Ｓｉ系では４５０℃前後、Ｃｏ−Ｓｉ系では５２０℃前後である。そのため、通常、これら２種類の析出物による時効硬化を同時に最大限利用することは難しい。ところが発明者らの研究によれば、上記の固溶化熱処理を終えた状態の材料を６００〜７９０℃の温度域で所定時間保持したのちに、後述の低温域で行う時効処理を組み合わせると、Ｃｏ−Ｓｉ系化合物が析出しやすいことがわかった。この６００〜７９０℃の温度域はＮｉ−Ｓｉ系化合物はほとんど析出せず、またＣｏ−Ｓｉ系化合物にとっては、析出は生じるが最適な析出温度を超えて高い温度域である。溶質原子が十分に固溶した母相を当該温度域に所定時間保持すると、Ｃｏ、Ｓｉを主とするエンブリオが形成され、これが後述の時効処理でＣｏ−Ｓｉ系化合物の析出の駆動力となるのではないかと推察される。このエンブリオの生成はＣｏ−Ｓｉ系化合物析出の前駆現象と考えることができる。 In Cu-Ni-Co-Si alloys, two types of precipitates, Ni-Si and Co-Si, each contribute to high strength, but the optimum precipitation conditions (temperature and time) between the two are Does not match (misaligned). The optimum precipitation temperature is around 450 ° C. for the Ni—Si system and around 520 ° C. for the Co—Si system. Therefore, it is usually difficult to maximize the aging hardening of these two types of precipitates at the same time. However, according to the research by the inventors, when the material after the above-mentioned solution heat treatment is held in a temperature range of 600 to 790 ° C. for a predetermined time and then combined with the aging treatment performed in a low temperature range described later, Co It was found that −Si compounds are likely to precipitate. In this temperature range of 600 to 790 ° C., almost no Ni-Si-based compound is precipitated, and for the Co-Si-based compound, precipitation occurs, but the temperature range is higher than the optimum precipitation temperature. When a matrix in which solute atoms are sufficiently solid-solved is held in the temperature range for a predetermined time, an embryo mainly composed of Co and Si is formed, which serves as a driving force for precipitation of Co—Si compounds in the aging treatment described later. It is speculated that it may be. The formation of this embryo can be considered as a precursor phenomenon of precipitation of Co—Si compounds.

前駆処理での保持時間、すなわち材料温度が６００〜７９０℃の範囲にある時間は１５〜３００秒の範囲とすることが好ましい。６００〜７９０℃の範囲内に設定した一定の温度に保持してもよいし、７９０℃から６００℃までの温度域を徐冷しながら通過させてもよい。 The retention time in the precursor treatment, that is, the time when the material temperature is in the range of 600 to 790 ° C. is preferably in the range of 15 to 300 seconds. It may be maintained at a constant temperature set in the range of 600 to 790 ° C., or may be passed through a temperature range of 790 ° C. to 600 ° C. while slowly cooling.

固溶化処理温度から７９０℃までの平均冷却速度は例えば５〜５０℃／ｓとすればよい。前駆処理の後は、時効処理温度範囲を急冷して通過させることが好ましい。例えば、６００℃から３００℃までの平均冷却速度が５０℃／ｓ以上となるように冷却することが好ましい。 The average cooling rate from the solution treatment temperature to 790 ° C. may be, for example, 5 to 50 ° C./s. After the precursor treatment, it is preferable that the aging treatment temperature range is rapidly cooled and passed. For example, it is preferable to cool the product so that the average cooling rate from 600 ° C. to 300 ° C. is 50 ° C./s or more.

〔時効処理〕
本発明で規定する化学組成のＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系合金の場合、前述の固溶化処理を終えていれば、３００〜５５０℃の温度範囲で時効処理を施すことによって０.２％耐力９００ＭＰａ以上の強度レベルを有する極薄板材を得ることができる。 [Aging process]
In the case of a Cu—Ni—Co—Si based alloy having the chemical composition specified in the present invention, if the above-mentioned solution treatment has been completed, 0.2% proof stress can be obtained by subjecting the aging treatment in the temperature range of 300 to 550 ° C. An ultrathin plate material having a strength level of 900 MPa or more can be obtained.

一方、固溶化処理後に前駆処理を施した場合には、３００〜４００℃の低温域での時効処理を行うことによって０.２％耐力１０００ＭＰａ以上の極めて高い強度レベルを達成できる。３１０〜３８０℃で時効処理を行うことがより好ましい。前駆処理でＣｏ−Ｓｉ系化合物粒子の核生成に関する自由エネルギーが大幅に低減してＣｏ−Ｓｉ系化合物が極めて析出しやすい組織状態となっているので、このような低温での時効でＣｏ−Ｓｉ系化合物の活発な生成が可能になるものと考えられる。この低温時効処理によれば、強度向上に最も効く粒径５〜１０ｎｍの微細第二相粒子が多量に形成されることがわかった。この低温時効処理によってＮｉ−Ｓｉ系化合物の析出も生じることが確認された。したがって、従来は難しかった２種類の析出物による析出硬化現象を有効に享受できる。また、時効処理温度を３００〜４００℃と低くすると、通常の時効処理よりも原子の拡散速度が遅くなる。そのため強化に寄与する固溶Ｓｉを残存させるためにも有利となる。 On the other hand, when the precursor treatment is performed after the solution treatment, an extremely high strength level of 0.2% proof stress of 1000 MPa or more can be achieved by performing the aging treatment in a low temperature range of 300 to 400 ° C. It is more preferable to carry out the aging treatment at 31 to 380 ° C. Since the free energy related to nucleation of Co-Si compound particles is significantly reduced by the precursor treatment and the structure is such that the Co-Si compound is extremely easy to precipitate, Co-Si is aged at such a low temperature. It is considered that active production of system compounds is possible. According to this low temperature aging treatment, it was found that a large amount of fine second phase particles having a particle size of 5 to 10 nm, which are most effective for improving the strength, are formed. It was confirmed that this low temperature aging treatment also caused precipitation of Ni—Si compounds. Therefore, it is possible to effectively enjoy the precipitation hardening phenomenon caused by two types of precipitates, which was difficult in the past. Further, when the aging treatment temperature is as low as 300 to 400 ° C., the diffusion rate of atoms becomes slower than that of the normal aging treatment. Therefore, it is also advantageous for leaving the solid solution Si that contributes to strengthening.

０.２％耐力が１０００ＭＰａ以上の高強度を狙う場合には、時効処理後に粒子径５〜１０ｎｍの「微細第二相粒子」の個数密度が１.０×１０⁹個／ｍｍ²個以上となる条件を採用することが望ましい。最適な時効時間は３〜１０時間の範囲に見出すことができる。 When aiming for high strength with a 0.2% proof stress of 1000 MPa or more, the number density of "fine second-phase particles" with a particle diameter of 5 to 10 nm should be 1.0 x 10 ⁹ / mm ² or more after aging treatment. It is desirable to adopt the following conditions. Optimal aging times can be found in the range of 3-10 hours.

最適な時効条件を決定する指標として、下記（３）式を挙げることができる。
０.６０≦ＥＣａｇｅ／ＥＣｍａｘ≦０.８０ …（３）
ここで、ＥＣｍａｘは３００〜５００℃の温度範囲において５０℃間隔で１０時間の熱処理を行った場合に得られる最大の導電率、ＥＣａｇｅは時効処理後の導電率である。ＥＣａｇｅ／ＥＣｍａｘを０.６０以上とすることにより析出量が十分に確保され、強度、導電率の改善に有利となる。また、ＥＣａｇｅ／ＥＣｍａｘを０.８０以下とすることにより母相中のＳｉ濃度が十分に確保され、加工硬化能の改善に有利となる。 The following equation (3) can be mentioned as an index for determining the optimum aging condition.
0.60 ≤ ECage / ECmax ≤ 0.80 ... (3)
Here, ECmax is the maximum conductivity obtained when heat treatment is performed at intervals of 50 ° C. for 10 hours in a temperature range of 300 to 500 ° C., and ECage is the conductivity after aging treatment. By setting ECage / ECmax to 0.60 or more, a sufficient amount of precipitation is secured, which is advantageous in improving strength and conductivity. Further, by setting ECage / ECmax to 0.80 or less, the Si concentration in the matrix phase is sufficiently secured, which is advantageous for improving the work hardening ability.

〔仕上冷間圧延〕
時効処理を終えた板材に仕上冷間圧延を施し、板厚１０〜６０μｍの極薄板材を得る。板厚を１０μｍ以上５０μｍ未満の範囲に管理してもよい。また、２０〜３５μｍの範囲に管理してもよい。極薄板材において前述のＢｒａｓｓ方位の集積度を高めるためには、この仕上冷間圧延のパススケジュールの設定が重要となる。発明者らの詳細な実験によれば、少なくとも圧延率が５０％未満である段階で開始する圧延パスでは１パス当たりの圧下率を１０.０％以上とし、かつトータル圧延率を９０％以上とする条件で仕上冷間圧延を施した場合において、後述の低温焼鈍を十分な張力付与下で行う処置との組み合わせによって、最終的にＢｒａｓｓ方位の集積度が高い極薄板材を実現できることがわかった。そのメカニズムについては現時点で未解明である。 [Finish cold rolling]
The plate material that has undergone the aging treatment is subjected to cold rolling for finishing to obtain an ultrathin plate material having a plate thickness of 10 to 60 μm. The plate thickness may be controlled in the range of 10 μm or more and less than 50 μm. Further, it may be managed in the range of 20 to 35 μm. In order to increase the degree of integration of the above-mentioned Brass direction in the ultra-thin plate material, it is important to set the pass schedule for this finish cold rolling. According to detailed experiments by the inventors, the rolling pass starting at least when the rolling ratio is less than 50% has a rolling reduction rate of 10.0% or more per pass and a total rolling ratio of 90% or more. It was found that when the finish cold rolling is performed under the conditions to be performed, an ultrathin plate material having a high degree of integration in the Brass direction can be finally realized by combining with the treatment of performing low temperature annealing under sufficient tension, which will be described later. .. The mechanism is unknown at this time.

この仕上冷間圧延では、ロール直径が例えば２５〜５０ｍｍのワークロールを使用すればよい。ロール直径が大きくなると、極薄板材への圧延に際して圧延荷重が過大となり、目標板厚まで圧延できない場合がある。一方、切り板を採取したときに平坦性の高い形状が実現できる極薄板材を得るためには、ロール径の大きいワークロールを使用することが有利である。検討の結果、前述の最大クロスボウｑ_MAXが２５０μｍ以下、Ｉ−ｕｎｉｔが５.０以下となる極薄板材を得る場合には、ロール直径が３５〜５０ｍｍのワークロールを使用することが好ましく、４０〜５０ｍｍのワークロールを使用することがより好ましい。 In this finish cold rolling, a work roll having a roll diameter of, for example, 25 to 50 mm may be used. If the roll diameter is large, the rolling load becomes excessive when rolling to an ultra-thin plate material, and it may not be possible to roll to the target plate thickness. On the other hand, it is advantageous to use a work roll having a large roll diameter in order to obtain an ultra-thin plate material that can realize a highly flat shape when the cut plate is collected. As a result of the examination, in order to obtain an ultrathin plate material having the above-mentioned maximum crossbow q _MAX of 250 μm or less and I-unit of 5.0 or less, it is preferable to use a work roll having a roll diameter of 35 to 50 mm. It is more preferable to use a work roll of ~ 50 mm.

〔低温焼鈍〕
仕上冷間圧延後には、通常、板条材の残留応力の低減、曲げ加工性の向上、空孔やすべり面上の転位の低減による耐応力緩和性向上等を目的として低温焼鈍が施される。本発明では、更にＢｒａｓｓ方位の集積度を高める目的でもこの低温焼鈍を利用する。Ｂｒａｓｓ方位の集積度を高めるためには、上述の仕上冷間圧延において、圧延率が５０％未満である段階で開始する圧延パスの圧下率を１０.０％以上とし、かつトータル圧延率を９０％以上とする条件で圧延を行った極薄材を適用する。そのうえで、この低温焼鈍では、１８０〜２２０Ｎ／ｍｍ²の圧延方向張力を付与しながら２５０〜３５０℃で１５０秒以上保持する条件を採用することが重要である。すなわち最高到達材料温度が２５０〜３５０℃の範囲となり、材料温度が２５０℃以上最高到達材料温度以下の温度域にある時間（保持時間）が１５０秒以上となるようにする。温度が低すぎる場合や保持時間が短すぎる場合は、残留応力低減など、低温焼鈍本来の目的が達成できない。張力が低すぎる場合や温度が高すぎる場合は、Ｂｒａｓｓ方位の集積度が高い極薄板材を得ることができない。 [Low temperature annealing]
After cold rolling, low-temperature annealing is usually performed for the purpose of reducing residual stress of strips, improving bending workability, and improving stress relaxation resistance by reducing pores and dislocations on slip surfaces. .. In the present invention, this low temperature annealing is also used for the purpose of further increasing the degree of integration of the Brass orientation. In order to increase the degree of integration in the Brass direction, in the above-mentioned finish cold rolling, the rolling pass reduction rate starting at the stage where the rolling rate is less than 50% is set to 10.0% or more, and the total rolling rate is 90. An ultra-thin material that has been rolled under the condition of% or more is applied. On top of that, in this low-temperature annealing, it is important to adopt the condition of holding at 250 to 350 ° C. for 150 seconds or more while applying a rolling direction tension of 180 to 220 N / mm ² . That is, the maximum reached material temperature is in the range of 250 to 350 ° C., and the time (holding time) in which the material temperature is in the temperature range of 250 ° C. or higher and the highest reached material temperature or lower is 150 seconds or longer. If the temperature is too low or the holding time is too short, the original purpose of low temperature annealing such as reduction of residual stress cannot be achieved. If the tension is too low or the temperature is too high, an ultrathin plate material with a high degree of integration in the Brass direction cannot be obtained.

一方、張力を付与して低温焼鈍を行うことは、良好な板形状を実現するためにも有効である。最大クロスボウｑ_MAXが２５０μｍ以下、Ｉ−ｕｎｉｔが５.０以下という平坦性を得るためには、１８０〜２２０Ｎ／ｍｍ²の張力を付与する熱処理において、特に、最高到達材料温度を２９０〜３５０℃、２５０℃以上最高到達材料温度以下の保持時間を１５０〜７２０秒とするとともに、前記最高到達材料温度までの昇温過程において最大昇温速度を７０℃／ｓ以下とし、かつ前記最高到達材料温度からの降温過程において最大冷却速度を７０℃／ｓ以下とすればよい。 On the other hand, applying tension to perform low-temperature annealing is also effective in achieving a good plate shape. In order to obtain flatness with a maximum crossbow q _MAX of 250 μm or less and an I-unit of 5.0 or less, the maximum temperature of the material reached 290 to 350 ° C. is particularly high in the heat treatment in which a tension of 180 to 220 N / mm ² is applied. The holding time of 250 ° C. or higher and the maximum reached material temperature or lower is set to 150 to 720 seconds, the maximum heating rate is set to 70 ° C./s or lower in the heating process to the maximum reached material temperature, and the maximum reached material temperature is set. The maximum cooling rate may be set to 70 ° C./s or less in the process of lowering the temperature from the above.

表１に示す組成の銅合金を溶製し、縦型半連続鋳造機を用いて鋳造した。得られた鋳片を表２に示す条件で加熱したのち炉から出し、厚さ１４ｍｍまで熱間圧延し、水冷した。なお、熱間圧延で割れが生じた一部の比較例では、その時点で製造を中止した。トータルの熱間圧延率は９０〜９５％である。熱間圧延後、表層の酸化層を機械研磨により除去（面削）した。次いで圧延率９０〜９９％で冷間圧延を行った。その後、表２に示す条件で溶体化処理を行った。溶体化処理の工程では一部の例を除き前述の前駆処理を施した。前駆処理は固溶化処理後の降温過程において所定温度に保持する方法で行った。固溶化処理温度から前駆処理温度まで平均冷却速度５〜５０℃／ｓｅｃで冷却し、前駆処理温度で表２に示す時間の保持を行い、その後、６００℃から３００℃までの平均冷却速度が５０℃／ｓｅｃ以上となるように常温まで冷却した。前駆処理を省略した一部の例では、固溶化処理温度から３００℃より低温の温度域まで急冷した。溶体化処理を終えた材料に、表２に示す条件で時効処理を施した。表２中に前記（３）式により定まるＥＣａｇｅ／ＥＣｍａｘ値を併記する。時効処理後の材料に、表３に示す条件で仕上冷間圧延を施した。表３のロール径は、使用したワークロールの直径を意味する。圧延率が５０％未満である段階で開始する各圧延パスでは、１パス当たりの圧下率を表３に示す一定の値とした。仕上冷間圧延後の板厚は表４に示してある。板厚５０μｍ未満まで圧延できなかった一部の比較例では、以降の工程を中止した。 A copper alloy having the composition shown in Table 1 was melted and cast using a vertical semi-continuous casting machine. The obtained slab was heated under the conditions shown in Table 2, then taken out of the furnace, hot-rolled to a thickness of 14 mm, and water-cooled. In some comparative examples where cracks were generated by hot rolling, production was discontinued at that time. The total hot rolling ratio is 90 to 95%. After hot rolling, the oxide layer on the surface was removed (face-cut) by mechanical polishing. Next, cold rolling was performed at a rolling ratio of 90 to 99%. Then, the solution treatment was carried out under the conditions shown in Table 2. In the solution treatment step, the above-mentioned precursor treatment was performed except for some examples. The precursor treatment was carried out by a method of maintaining the temperature at a predetermined temperature in the temperature lowering process after the solution treatment. Cool from the solidification treatment temperature to the precursor treatment temperature at an average cooling rate of 5 to 50 ° C./sec, maintain the time shown in Table 2 at the precursor treatment temperature, and then the average cooling rate from 600 ° C to 300 ° C is 50. It was cooled to room temperature so as to be ℃ / sec or more. In some examples where the precursor treatment was omitted, the solution was rapidly cooled from the solution treatment temperature to a temperature range lower than 300 ° C. The material that had been solution-treated was aged under the conditions shown in Table 2. The ECage / ECmax values determined by the above equation (3) are also shown in Table 2. The material after the aging treatment was subjected to finish cold rolling under the conditions shown in Table 3. The roll diameter in Table 3 means the diameter of the work roll used. For each rolling pass starting at the stage where the rolling rate is less than 50%, the rolling reduction rate per pass was set to a constant value shown in Table 3. The plate thickness after cold rolling is shown in Table 4. In some comparative examples where rolling was not possible to a plate thickness of less than 50 μm, the subsequent steps were stopped.

次いで表３に記載の条件で低温焼鈍を施した。表３に示した低温焼鈍の温度は最高到達材料温度、低温焼鈍の時間は２５０℃以上の保持時間、すなわち材料温度が２５０℃以上最高到達材料温度以下である時間を意味する。低温焼鈍はカテナリー炉を連続通板する方法で行った。炉内雰囲気は窒素と水素の混合雰囲気とした。昇温開始から冷却終了までの板表面の温度を通板方向の種々の位置で測定し、各測定位置の平均温度の値を用いて、横軸に時間、縦軸に温度をとった温度曲線を求めた。１つの供試材においては通板中の板の全長にわたって同じ条件で熱処理を施しており、各測定位置での温度は経時的にほぼ一定値に安定しているので、この温度曲線の昇温時における最大勾配を当該供試材の最大昇温速度、冷却時における最大勾配を当該供試材の最大冷却速度として採用した。供試材毎の昇温速度および冷却速度は、それぞれ昇温ゾーンおよび冷却ゾーンにおける加熱出力、雰囲気温度、ファン回転数などを通板方向位置に応じて適切にコントロールすることにより調整した。また、低温焼鈍中の張力は、炉内を通板中の材料のカテナリー曲線（炉内通板方向両端部および中央部の板の高さ位置、並びに炉内長）から算出した。 Then, low temperature annealing was performed under the conditions shown in Table 3. The low-temperature annealing temperature shown in Table 3 means the maximum reached material temperature, and the low-temperature annealing time means a holding time of 250 ° C. or higher, that is, a time when the material temperature is 250 ° C. or higher and lower than the highest reached material temperature. The low temperature annealing was carried out by a method of continuously passing through a catenary furnace. The atmosphere inside the furnace was a mixed atmosphere of nitrogen and hydrogen. A temperature curve in which the temperature of the plate surface from the start of temperature rise to the end of cooling is measured at various positions in the plate direction, and the horizontal axis is time and the vertical axis is temperature using the average temperature value of each measurement position. Asked. In one test material, heat treatment is performed under the same conditions over the entire length of the plate being passed through, and the temperature at each measurement position is stable at a substantially constant value over time, so the temperature rise of this temperature curve The maximum gradient at time was adopted as the maximum temperature rise rate of the test material, and the maximum gradient during cooling was adopted as the maximum cooling rate of the test material. The heating rate and cooling rate for each test material were adjusted by appropriately controlling the heating output, atmospheric temperature, fan speed, etc. in the heating zone and cooling zone according to the position in the plate direction. The tension during low-temperature annealing was calculated from the catenary curves of the material in the plate passing through the furnace (the height positions of the plates at both ends and the center in the direction of the plate passing through the furnace, and the length inside the furnace).

低温焼鈍後にスリッターでスリット加工して、圧延直角方向の板幅Ｗ₀が５１０ｍｍの薄板材製品（供試材）を得た。 After low-temperature annealing, slitting was performed with a slitter to obtain a thin plate product (test material) having a plate width W _{0 in the} direction perpendicular to rolling of 510 mm.

各供試材について、以下の調査を行った。
〔Ｂｒａｓｓ方位｛０１１｝＜２１１＞の集積度〕
各供試材から採取した試験片について、上掲の「｛０１１｝＜２１１＞集積度の求め方」に従って、ＥＢＳＤ測定装置を備えるＦＥ−ＳＥＭ（ＪＥＯＬ社製、ＪＸＡ−８５３０Ｆ）により、ＥＢＳＤ法で｛０１１｝＜２１１＞集積度を求めた。ＥＢＳＤデータの解析には、ＴＳＬソリューションズ社製ＯＩＭ 結晶方位解析装置を使用した。 The following surveys were conducted on each test material.
[Integration degree of Brass direction {011} <211>]
For the test pieces collected from each test material, the EBSD method was performed by FE-SEM (JEOL, JXA-8530F) equipped with an EBSD measuring device according to the above "{011} <211> How to determine the degree of integration". {011} <211> The degree of integration was obtained. An OIM crystal orientation analyzer manufactured by TSL Solutions Co., Ltd. was used for the analysis of EBSD data.

〔微細第二相粒子の個数密度〕
供試材から直径３ｍｍの円板を打ち抜き、ツインジェット研磨法でＴＥＭ観察試料を作製し、ＴＥＭ（日本電子株式会社製、ＥＭ−２０１０）にて加速電圧２００ｋＶで倍率１０万倍の無作為に選択した１０視野について写真を撮影し、その写真上で粒子径５〜１０ｎｍの微細第二相粒子の数をカウントし、その合計数を観察領域の総面積で除することにより微細第二相粒子の個数密度（個／ｍｍ²）を求めた。ここでは１視野の大きさを７７０ｎｍ×５５０ｎｍとした。粒子径は当該粒子を取り囲む最小円の直径とした。 [Number density of fine second phase particles]
A disk with a diameter of 3 mm is punched from the test material, a TEM observation sample is prepared by the twin jet polishing method, and a TEM (manufactured by Nippon Denshi Co., Ltd., EM-2010) is used at an acceleration voltage of 200 kV and a magnification of 100,000 times at random. A photograph is taken for the selected 10 fields, the number of fine second phase particles having a particle diameter of 5 to 10 nm is counted on the photograph, and the total number is divided by the total area of the observation area to obtain the fine second phase particles. The number density (pieces / mm ² ) of Here, the size of one field of view is 770 nm × 550 nm. The particle diameter was the diameter of the smallest circle surrounding the particle.

〔エッチング面の表面粗さ〕
エッチング液として、塩化第二鉄４２ボーメを用意した。供試材の片側表面を板厚が半減するまでエッチングした。得られたエッチング面について、レーザー式表面粗さ計にて圧延直角方向の表面粗さを測定し、ＪＩＳ Ｂ０６０１：２０１３に従う算術平均粗さＲａを求めた。このエッチング試験によるＲａが０.１５μｍ以下であれば、従来のＣｕ−Ｎｉ−Ｃｏ−Ｓｉ系銅合金薄板材と比べ、エッチング面の表面平滑性は顕著に改善されていると評価できる。すなわち、微小サイズの導電ばね部材の作製において直線性の良いエッチングが可能であり、寸法精度の高い部品を得るために適したエッチング加工性を有していると判断される。従って、上記Ｒａが０.１５μｍ以下のものを合格（エッチング加工性；良好）と判定した。 [Surface roughness of etched surface]
As an etching solution, ferric chloride 42 Baume was prepared. One surface of the test material was etched until the plate thickness was halved. With respect to the obtained etched surface, the surface roughness in the direction perpendicular to rolling was measured with a laser type surface roughness meter, and the arithmetic average roughness Ra according to JIS B0601: 2013 was obtained. When Ra by this etching test is 0.15 μm or less, it can be evaluated that the surface smoothness of the etched surface is remarkably improved as compared with the conventional Cu—Ni—Co—Si based copper alloy thin plate material. That is, it is judged that etching with good linearity is possible in the production of a small-sized conductive spring member, and that the etching processability is suitable for obtaining a part with high dimensional accuracy. Therefore, those having Ra of 0.15 μm or less were judged to be acceptable (etchability; good).

〔圧延方向の０.２％耐力〕
各供試材から圧延方向（ＬＤ）の引張試験片（ＪＩＳ ５号）を採取し、試験数ｎ＝３でＪＩＳ Ｚ２２４１に準拠した引張試験行い、０.２％耐力を測定した。ｎ＝３の平均値を当該供試材の成績値とした。
〔Ｉ−ｕｎｉｔ〕
各供試材から圧延方向長さが４００ｍｍ、圧延直角方向長さが板幅Ｗ₀（ｍｍ）である長方形の切り板Ｑを採取し、上述（Ｂ）に定義されるＩ−ｕｎｉｔを求めた。
〔最大クロスボウｑ_MAX〕
各供試材について上述（Ａ）に定義される最大クロスボウｑ_MAXを求めた。
これらの結果を表４に示す。 [0.2% proof stress in rolling direction]
Tensile test pieces (JIS No. 5) in the rolling direction (LD) were sampled from each test material, and a tensile test was performed in accordance with JIS Z2241 with the number of tests n = 3, and 0.2% proof stress was measured. The average value of n = 3 was used as the performance value of the test material.
[I-unit]
A rectangular cut plate Q having a rolling direction length of 400 mm and a rolling perpendicular direction length of plate width W ₀ (mm) was collected from each test material, and the I-unit defined in (B) above was obtained. ..
[Maximum crossbow q _MAX ]
The maximum crossbow q _MAX defined in (A) above was determined for each test material.
These results are shown in Table 4.

本発明例のものはいずれもＢｒａｓｓ方位｛０１１｝＜２１１＞の集積度が５.０以上と高く、優れたエッチング加工性を呈した。このうち、Ｎｏ.１〜２０は、０.２％耐力が１０００ＭＰａ以上という高強度と、最大クロスボウｑ_MAXが２５０μｍ以下、Ｉ−ｕｎｉｔが５.０以下という平坦性の高い板形状をも具備するものである。Ｎｏ.２１〜３１は、優れたエッチング加工性が得られる製造条件範囲において、一部の製造条件を変更して、強度および板形状での影響を調べたものである。具体的には、Ｎｏ.２１は鋳片加熱温度を低くしたもの、Ｎｏ.２２は溶体化処理工程で前駆処理を省いたもの、Ｎｏ.２３は時効処理温度を低くしたもの、Ｎｏ.２４は時効処理温度を高くしたもの、Ｎｏ.２５は鋳片加熱時間を短くしたもの、Ｎｏ.２６は溶体化処理工程で固溶化温度を高くしたもの、Ｎｏ.２９は低温焼鈍の保持時間を長くしたものであり、これらはいずれも微細第二相粒子の量が少なくなり、０.２％耐力が１０００ＭＰａ以上の強度レベルには至っていない。Ｎｏ.２７は仕上冷間圧延で直径の小さいワークロールを使用したもの、Ｎｏ.２８は低温焼鈍の温度を低くしたもの、Ｎｏ.３０は低温焼鈍の最大昇温速度を大きくしたもの、Ｎｏ.３１は低温焼鈍の最大冷却速度を大きくしたものであり、これらはいずれも最大クロスボウｑ_MAXが２５０μｍ以下、Ｉ−ｕｎｉｔが５.０以下という平坦性の高い板形状の実現には至っていない。 All of the examples of the present invention had a high degree of integration of the Brass orientation {011} <211> of 5.0 or more, and exhibited excellent etching processability. Of these, Nos. 1 to 20 also have a high strength with a 0.2% proof stress of 1000 MPa or more, and a highly flat plate shape with a maximum crossbow q _MAX of 250 μm or less and an I-unit of 5.0 or less. It is a thing. Nos. 21 to 31 are the ones in which some manufacturing conditions are changed in the manufacturing condition range in which excellent etching processability can be obtained, and the influence on the strength and the plate shape is investigated. Specifically, No. 21 is the one in which the slab heating temperature is lowered, No. 22 is the one in which the precursor treatment is omitted in the solution treatment step, No. 23 is the one in which the aging treatment temperature is lowered, and No. 24 is No. 25 has a higher aging treatment temperature, No. 25 has a shorter slab heating time, No. 26 has a higher solidification temperature in the solution treatment process, and No. 29 has a longer holding time for low-temperature annealing. In each case, the amount of fine second-phase particles is small, and the 0.2% proof stress does not reach the strength level of 1000 MPa or more. No. 27 is a work roll with a small diameter for finish cold rolling, No. 28 is a product in which the temperature of low temperature annealing is lowered, and No. 30 is a product in which the maximum temperature rise rate of low temperature annealing is increased. Reference numeral 31 is an increase in the maximum cooling rate of low-temperature annealing, and none of these has achieved a highly flat plate shape having a maximum crossbow q _MAX of 250 μm or less and an I-unit of 5.0 or less.

比較例であるＮｏ.５０はＮｉとＣｏの合計含有量が高く、Ｎｏ.５２はＣｏ含有量およびＳｉ含有量が高いので、これらは粗大第二相粒子が過大となって微細第二相粒子の量が少なくなり、結果的にＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。また、０.２％耐力が１０００ＭＰａ以上の強度レベルも得られていない。Ｎｏ.５１はＮｉとＣｏの合計含有量が低いので微細第二相粒子の量が少なくなり、結果的にＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。Ｎｏ.５３は鋳片加熱温度が高かったので熱間圧延で割れが生じ、後工程に進めることができなかった。Ｎｏ.５４は仕上冷間圧延で使用したワークロールの直径が大きかったので５０μｍ未満まで板厚を減じることができず、後工程へ進めることを中止した。Ｎｏ.５５は仕上冷間圧延において圧延率が５０％未満である段階で開始する圧延パスの圧下率が低く、Ｎｏ.５６は仕上冷間圧延のトータル圧延率が低いので、これらはＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。Ｎｏ.５７は低温焼鈍での張力が高いのでＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。また、最大クロスボウｑ_MAXを十分低減することもできなかった。Ｎｏ.５８は低温焼鈍での張力が低いのでＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。また、Ｉ−ｕｎｉｔおよび最大クロスボウｑ_MAXを十分低減することもできなかった。Ｎｏ.５９は低温焼鈍の温度が高いのでＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。また、０.２％耐力が１０００ＭＰａ以上の強度レベルも得られていない。Ｎｏ.６０は低温焼鈍の保持時間が短いのでＢｒａｓｓ方位の集積度を高めることができず、エッチング加工性に劣った。 Since No. 50, which is a comparative example, has a high total content of Ni and Co, and No. 52 has a high Co content and Si content, these are fine second-phase particles due to excessive coarse second-phase particles. As a result, the degree of integration of the Brass direction could not be increased, and the etching processability was inferior. In addition, a strength level with a 0.2% proof stress of 1000 MPa or more has not been obtained. In No. 51, since the total content of Ni and Co was low, the amount of fine second phase particles was small, and as a result, the degree of integration of the Brass orientation could not be increased, and the etching processability was inferior. In No. 53, since the slab heating temperature was high, cracks occurred in hot rolling, and it was not possible to proceed to the subsequent process. In No. 54, since the diameter of the work roll used in the finish cold rolling was large, the plate thickness could not be reduced to less than 50 μm, and the progress to the subsequent process was stopped. No. 55 has a low rolling pass reduction rate that starts when the rolling ratio is less than 50% in the finish cold rolling, and No. 56 has a low total rolling rate in the finish cold rolling, so these are in the Brass direction. The degree of integration could not be increased, and the etching processability was inferior. In No. 57, since the tension in low-temperature annealing was high, the degree of integration in the Brass direction could not be increased, and the etching processability was inferior. In addition, the maximum crossbow q _MAX could not be sufficiently reduced. In No. 58, since the tension in low-temperature annealing was low, the degree of integration in the Brass direction could not be increased, and the etching processability was inferior. In addition, the I-unit and the maximum crossbow q _MAX could not be sufficiently reduced. In No. 59, since the low temperature annealing temperature was high, the degree of integration in the Brass direction could not be increased, and the etching processability was inferior. In addition, a strength level with a 0.2% proof stress of 1000 MPa or more has not been obtained. In No. 60, since the holding time of low-temperature annealing was short, the degree of integration in the Brass direction could not be increased, and the etching processability was inferior.

Claims (6)

質量％で、ＮｉとＣｏの合計：２.５０〜４.００％、Ｃｏ：０.５０〜２.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.５０％、Ｍｇ：０〜０.１０％、Ｓｎ：０〜０.５０％、Ｚｎ：０〜０.１５％、Ｂ：０〜０.１０％、Ｐ：０〜０.１０％、ＲＥＭ（希土類元素）：０〜０.１０％、Ｃｒ、Ｚｒ、Ｈｆ、Ｎｂ、Ｓの合計：０〜０.０５％、残部Ｃｕおよび不可避的不純物からなる化学組成を有し、ＥＢＳＤ（電子線後方散乱回折）法により、展開次数１６、ガウス分布近似の半値幅５°として調和関数法で求めた方位分布関数（ＯＤＦ）を用いて、完全ランダム方位分布に対する強度比として特定されるＢｒａｓｓ方位｛０１１｝＜２１１＞の集積度が５.００以上である結晶配向を有する、板厚１０〜６０μｍの銅合金薄板材。 By mass%, the total of Ni and Co: 2.50 to 4.00%, Co: 0.50 to 2.00%, Si: 0.50 to 1.50%, Fe: 0 to 0.50%, Mg: 0 to 0.10%, Sn: 0 to 0.50%, Zn: 0 to 0.15%, B: 0 to 0.10%, P: 0 to 0.10%, REM (rare earth element) : 0 to 0.10%, total of Cr, Zr, Hf, Nb, S: 0 to 0.05%, having a chemical composition consisting of the balance Cu and unavoidable impurities, EBSD (Electron Backscatter Diffraction) method The Brass orientation {011} <211> specified as the intensity ratio to the completely random orientation distribution using the orientation distribution function (ODF) obtained by the harmonic function method with the expansion order 16 and the half-value width of the Gaussian distribution approximation 5 °. A copper alloy thin plate material having a plate thickness of 10 to 60 μm and having a crystal orientation having a degree of integration of 5.00 or more. マトリックス（金属素地）中に存在する粒子径５〜１０ｎｍの微細第二相粒子の個数密度が１.０×１０^９個／ｍｍ^２以上である金属組織を有する請求項１に記載の銅合金薄板材。 The thin copper alloy according to claim 1, which has a metal structure in which the number density of fine second-phase particles having a particle diameter of 5 to 10 nm existing in the matrix (metal base) is 1.0 × 10 ⁹ particles / mm ² or more. Plate material. 下記（Ａ）に定義する最大クロスボウｑ_ＭＡＸが２５０μｍ以下である請求項１または２に記載の銅合金薄板材。
（Ａ）当該銅合金板材から圧延方向長さが５０ｍｍ、圧延直角方向長さが板幅Ｗ_０（ｍｍ）である長方形の切り板Ｐを採取し、その切り板Ｐをさらに圧延直角方向５０ｍｍピッチで裁断し、その際、圧延直角方向長さが５０ｍｍに満たない小片が切り板Ｐの圧延直角方向端部に発生したときはその小片を除き、ｎ個（ｎは板幅Ｗ_０／５０の整数部分）の５０ｍｍ角の正方形サンプルを用意する。各正方形サンプルごとに、日本伸銅協会技術規格ＪＣＢＡ Ｔ３２０：２００３に規定の三次元測定装置による測定方法（ただし、ｗ＝５０ｍｍとする）に従い、水平盤上に置いたときのクロスボウｑを、両面（両側の板面）について圧延直角方向に測定し、各面のｑの絶対値｜ｑ｜の最大値を当該正方形サンプルのクロスボウｑ_ｉ（ｉは１〜ｎ）とする。ｎ個の正方形サンプルのクロスボウｑ_１〜ｑ_ｎのうちの最大値を最大クロスボウｑ_ＭＡＸとする。 The copper alloy thin plate material according to claim 1 or 2, wherein the maximum crossbow q _MAX defined in the following (A) is 250 μm or less.
(A) A rectangular cut plate P having a rolling direction length of 50 mm and a rolling perpendicular direction length of plate width W ₀ (mm) is collected from the copper alloy plate material, and the cut plate P is further rolled at a right angle direction of 50 mm pitch. At that time, if small pieces with a length of less than 50 mm in the rolling perpendicular direction are generated at the end of the cutting plate P in the rolling perpendicular direction, the small pieces are removed and n pieces (n is the plate width W _0/50 ). Prepare a 50 mm square square sample (the integer part). For each square sample, the crossbow q when placed on a horizontal plate is placed on both sides according to the measurement method (however, w = 50 mm) by the three-dimensional measuring device specified in the Japan Copper and Rolling Association technical standard JCBA T320: 2003. (Plate surfaces on both sides) are measured in the direction perpendicular to rolling, and the maximum value of the absolute value | q | of q on each surface is defined as the crossbow q _i (i is 1 to n) of the square sample. Let the maximum value of the crossbow q _{1 to} q _n of the _n square samples be the maximum crossbow q _MAX . 圧延方向の０.２％耐力が１０００ＭＰａ以上である請求項１〜３のいずれか１項に記載の銅合金薄板材。 The copper alloy thin plate material according to any one of claims 1 to 3 , wherein the 0.2% proof stress in the rolling direction is 1000 MPa or more. 請求項１〜４のいずれか１項に記載の銅合金薄板材を材料に用いた導電部材。 A conductive member using the copper alloy thin plate material according to any one of claims 1 to 4 as a material. 質量％で、ＮｉとＣｏの合計：２.５０〜４.００％、Ｃｏ：０.５０〜２.００％、Ｓｉ：０.５０〜１.５０％、Ｆｅ：０〜０.５０％、Ｍｇ：０〜０.１０％、Ｓｎ：０〜０.５０％、Ｚｎ：０〜０.１５％、Ｂ：０〜０.１０％、Ｐ：０〜０.１０％、ＲＥＭ（希土類元素）：０〜０.１０％、Ｃｒ、Ｚｒ、Ｈｆ、Ｎｂ、Ｓの合計：０〜０.０５％、残部Ｃｕおよび不可避的不純物からなる化学組成を有する鋳片を製造し、鋳片加熱、熱間圧延、冷間圧延、溶体化処理、時効処理、仕上冷間圧延、低温焼鈍の各工程を上記の順に有する手順で板厚１０〜６０μｍの銅合金薄板材を製造するに際し、
仕上冷間圧延工程において、少なくとも圧延率が５０％未満である段階で開始する圧延パスでは１パス当たりの圧下率を１０.０％以上とし、かつトータル圧延率を９０％以上とする条件で冷間圧延を施し、
低温焼鈍工程において、１８０〜２２０Ｎ／ｍｍ^２の張力を付与しながら２５０〜３５０℃で１５０秒以上保持する条件で熱処理を施す、請求項１〜４のいずれか１項に記載の銅合金薄板材の製造方法。 In terms of mass%, the total of Ni and Co: 2.50 to 4.00%, Co: 0.50 to 2.00%, Si: 0.50 to 1.50%, Fe: 0 to 0.50%, Mg: 0 to 0.10%, Sn: 0 to 0.50%, Zn: 0 to 0.15%, B: 0 to 0.10%, P: 0 to 0.10%, REM (rare earth element) : 0 to 0.10%, total of Cr, Zr, Hf, Nb, S: 0 to 0.05%, a slab having a chemical composition consisting of the balance Cu and unavoidable impurities is produced, and the slab is heated and heated. When producing a copper alloy thin plate material with a plate thickness of 10 to 60 μm by a procedure having each of the steps of inter-rolling, cold rolling, solution treatment, aging treatment, finish cold rolling, and low-temperature annealing in the above order.
In the finish cold rolling process, in the rolling pass started at least when the rolling rate is less than 50%, the rolling pass is cooled under the condition that the rolling reduction rate per pass is 10.0% or more and the total rolling rate is 90% or more. Rolled between
The copper alloy thin plate material according to any one of claims 1 to 4, which is subjected to heat treatment under the condition of holding at 250 to 350 ° C. for 150 seconds or more while applying a tension of 180 to 220 N / mm ² in the low temperature annealing step. Manufacturing method.