JP2010150597A - Rolled copper foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolled copper foil having excellent flexibility at low cost for corresponding to the request of higher flexibility to a flexible wiring member, such as a flexible printed circuit. <P>SOLUTION: The rolled copper foil, is the one after the last cold-rolling process and before recrystallizing-annealing, and composed of the pure copper containing ≤300 ppm oxygen, and in the result obtained with an X-ray diffraction pole figure measurement using the rolled surface as an reference, the rolled copper foil has a characteristic in the existence of the crystal grain, with which the diffraction peaks to �220}<SB>Cu</SB>surface of the copper crystal obtained with β-scanning in α angle=45° in the pole figure measurement, show 4-times symmetry by existing at least in each 90±5° of β angle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、圧延銅箔に関し、特に、フレキシブルプリント配線板等の可撓性配線部材に好適な優れた屈曲特性を有する圧延銅箔に関するものである。   The present invention relates to a rolled copper foil, and more particularly to a rolled copper foil having excellent bending characteristics suitable for a flexible wiring member such as a flexible printed wiring board.

フレキシブルプリント配線板（Flexible Printed Circuit、以下、FPCと称す）は、厚みが薄く可撓性に優れる特長から、電子機器等への実装形態における自由度が高い。そのため、現在では、折り畳み式携帯電話の折り曲げ部・デジタルカメラ・プリンターヘッドなどの可動部、ならびに、HDD （Hard Disk Drive）やDVD （Digital Versatile Disc），CD （Compact Disk）など、ディスク関連機器の可動部の配線等にFPCが広く用いられている。   A flexible printed circuit (hereinafter referred to as “FPC”) has a high degree of freedom in mounting on an electronic device or the like because of its thin thickness and excellent flexibility. For this reason, the folding parts of foldable mobile phones, movable parts such as digital cameras and printer heads, and disk-related equipment such as HDD (Hard Disk Drive), DVD (Digital Versatile Disc), and CD (Compact Disk) are now available. FPC is widely used for wiring of movable parts.

FPCの導電体としては、種々の表面処理が施された純銅箔または銅合金箔（以下、単に「銅箔」という）が一般的に用いられている。銅箔は、その製造方法の違いにより、電解銅箔と圧延銅箔に大別される。FPCは、前述のように繰り返し可動する部分の配線材として用いられることから優れた屈曲特性（例えば、100万回以上の屈曲特性）が要求され、銅箔としては圧延銅箔が使用されることが多い。   As the FPC conductor, pure copper foil or copper alloy foil (hereinafter simply referred to as “copper foil”) subjected to various surface treatments is generally used. Copper foils are roughly classified into electrolytic copper foils and rolled copper foils depending on the manufacturing method. FPC is used as a wiring material for parts that can be repeatedly moved as described above, and therefore excellent bending characteristics (for example, bending characteristics of 1 million times or more) are required, and rolled copper foil is used as the copper foil. There are many.

一般的に、圧延銅箔の製造は、原材料となるタフピッチ銅（JIS H3100 C1100）や無酸素銅（JIS H3100 C1020）等の純銅の鋳塊に熱間圧延を施した後、所定の厚さまで冷間圧延と中間焼鈍を繰り返し施すことによって行われる。FPC用の圧延銅箔に要求される厚さは、通常、50μm以下であるが、最近では十数μm以下と更に薄くなる傾向にある。   In general, the production of rolled copper foil is performed by hot-rolling pure copper ingots such as tough pitch copper (JIS H3100 C1100) and oxygen-free copper (JIS H3100 C1020), which are raw materials, and then cooling to a predetermined thickness. It is performed by repeatedly performing hot rolling and intermediate annealing. The thickness required for the rolled copper foil for FPC is usually 50 μm or less, but recently, it has a tendency to be further reduced to a dozen μm or less.

FPCの製造工程は、概略的に、「FPC用銅箔と、ポリイミドなどの樹脂からなるベースフィルム（基材）とを貼り合わせてCCL （Copper Claded Laminate）を形成する工程（CCL工程）」と、「該CCLにエッチング等の手法により回路配線を形成する工程」と、「該回路上に配線保護のための表面処理を行う工程」などから構成されている。CCL工程には、接着剤を介して銅箔と基材を積層した後、熱処理により接着剤を硬化して密着させる（３層CCL）方法と、接着剤を介さず、表面処理の施された銅箔を基材に直接張り合わせた後、加熱・加圧により一体化する（２層CCL）方法の２種類がある。   The manufacturing process of FPC is roughly as follows: "Copper foil for FPC and base film (base material) made of resin such as polyimide to form CCL (Copper Claded Laminate) (CCL process)" , “A step of forming a circuit wiring on the CCL by a technique such as etching”, “a step of performing a surface treatment for protecting the wiring on the circuit”, and the like. In the CCL process, after laminating the copper foil and the base material via an adhesive, the adhesive was cured and adhered by heat treatment (three-layer CCL), and the surface treatment was applied without using the adhesive. There are two types of methods in which a copper foil is directly bonded to a substrate and then integrated by heating and pressing (two-layer CCL).

ここで、FPCの製造工程においては、製造の容易性の観点から冷間圧延加工上がり（加工硬化した硬質な状態）の銅箔が用いられることが多い。銅箔が焼鈍された（軟化した）状態にあると、銅箔の裁断や基材との積層時に銅箔の変形（例えば、伸び、しわ、折れ、等）が生じ易く、製品不良になりやすいためである。   Here, in the manufacturing process of the FPC, a copper foil that has been cold-rolled (hardened after work hardening) is often used from the viewpoint of ease of manufacturing. When the copper foil is in an annealed (softened) state, the copper foil is likely to be deformed (for example, stretched, wrinkled, broken, etc.) during the cutting of the copper foil or the lamination with the base material, resulting in a defective product. Because.

一方、銅箔の屈曲特性は、再結晶焼鈍を行うことにより、圧延加工上がりの状態よりも著しく向上する。そこで、上述のCCL工程における基材と銅箔とを密着・一体化させるための熱処理で、銅箔の再結晶焼鈍を兼ねる製造方法が一般的に選択されている。なお、このときの熱処理条件は、180〜300℃で１〜60分間（代表的には200℃で30分間）であり、銅箔は再結晶組織に調質した状態となる。   On the other hand, the bending characteristics of the copper foil are remarkably improved as compared with the state after the rolling process by performing recrystallization annealing. Therefore, a manufacturing method that also serves as recrystallization annealing of the copper foil is generally selected in the heat treatment for bringing the base material and the copper foil into close contact and integration in the above-described CCL process. The heat treatment conditions at this time are 180 to 300 ° C. for 1 to 60 minutes (typically 200 ° C. for 30 minutes), and the copper foil is tempered into a recrystallized structure.

FPCの屈曲特性を高めるためには、その素材となる圧延銅箔の屈曲特性を高めることが有効である。また、一般的に、再結晶焼鈍後の銅箔の屈曲特性は、立方体集合組織が発達するほど向上することが知られている。なお、一般に言われている「立方体集合組織が発達」とは、圧延面において{２００}_Cu面の占有率が高いこと（例えば、85％以上）のみを意味する。 In order to improve the bending characteristics of FPC, it is effective to increase the bending characteristics of the rolled copper foil as the material. In general, it is known that the bending characteristics of a copper foil after recrystallization annealing improve as the cubic texture develops. Note that “cubic texture development” generally referred to only means that the occupancy of the {200} _Cu surface is high (for example, 85% or more) on the rolled surface.

従来、屈曲特性に優れた圧延銅箔やその製造方法として、次のようなものが報告されている。最終冷間圧延工程の総加工度を高くすること（例えば、90％以上）によって立方体集合組織を発達させる方法、および再結晶焼鈍後の立方体集合組織の発達度合を規定した銅箔（例えば、圧延面のＸ線回折で求めた(２００)面の強度が粉末Ｘ線回折で求めた(２００)面の強度の20倍より大きい銅箔）。最終冷間圧延工程前の中間焼鈍の際に立方体集合組織を発達させておき、最終冷間圧延工程の総加工度を93％以上にして再結晶後の立方体集合組織を更に発達させる方法。銅箔板厚方向の貫通結晶粒の割合を規定した銅箔（例えば、断面面積率で40％以上が貫通結晶粒である銅箔）。微量添加元素の添加により軟化温度を制御した銅箔（例えば、120〜150℃の半軟化温度に制御した銅箔）。双晶境界の長さを規定した銅箔（例えば、長さ５μmを超える双晶境界が１mm²の面積あたり合計長さ20 mm以下である銅箔）。微量添加元素の添加により再結晶組織を制御した銅箔（例えば、Snを0.01〜0.2質量％添加し、平均結晶粒径を５μm以下、最大結晶粒径を15μm以下に制御した銅箔）などが報告されている（例えば、特許文献１乃至７参照）。 Conventionally, the following has been reported as a rolled copper foil having excellent bending characteristics and a method for producing the same. A method for developing a cubic texture by increasing the total degree of work in the final cold rolling process (for example, 90% or more), and a copper foil that defines the degree of development of the cubic texture after recrystallization annealing (for example, rolling) A copper foil having a strength of (200) plane determined by X-ray diffraction of the plane greater than 20 times the strength of (200) plane determined by powder X-ray diffraction. A method in which a cube texture is developed during intermediate annealing before the final cold rolling step, and the total degree of work in the final cold rolling step is set to 93% or more to further develop the cube texture after recrystallization. A copper foil that defines the ratio of through crystal grains in the thickness direction of the copper foil plate (for example, a copper foil having a cross-sectional area ratio of 40% or more being through crystal grains). A copper foil whose softening temperature is controlled by adding a trace amount of additive elements (for example, a copper foil controlled to a semi-softening temperature of 120 to 150 ° C.). A copper foil having a defined twin boundary length (for example, a copper foil having a twin boundary exceeding 5 μm in length and having a total length of 20 mm or less per 1 mm ² area). Copper foils whose recrystallized structure is controlled by adding trace elements (for example, copper foils with 0.01 to 0.2% by mass of Sn added, controlled to an average crystal grain size of 5 μm or less and a maximum crystal grain size of 15 μm or less), etc. Have been reported (for example, see Patent Documents 1 to 7).

特開２００１−２６２２９６号公報JP 2001-262296 A 特許第３００９３８３号公報Japanese Patent No. 3009383 特開２００１−３２３３５４号公報JP 2001-323354 A 特開２００６−１１７９７７号公報JP 2006-117777 A 特開２０００−２１２６６１号公報JP 2000-212661 A 特開２０００−２５６７６５号公報JP 2000-256765 A 特開２００５−６８４８４号公報JP 2005-68484 A

前述したように、従来技術では、最終冷間圧延工程の総加工度を高くするほど再結晶焼鈍後に圧延銅箔の立方体集合組織が発達して屈曲性が向上すると報告されている。しかしながら、冷間圧延加工においては、総加工度が高くなるほど加工硬化によって材料（銅箔）が硬くなることから、１パスあたりの加工度の制御が難しくなり圧延銅箔の製造効率が低下する問題がある。具体的には、冷間圧延の総加工度が約90％以上（特に93％以上）になると、１パスあたりの加工度制御や圧延加工自体が急激に難しくなる。   As described above, it has been reported in the prior art that the higher the total degree of work in the final cold rolling step, the more the cubic texture of the rolled copper foil develops after recrystallization annealing and the flexibility increases. However, in cold rolling, the higher the total degree of work, the harder the material (copper foil) by work hardening, so the control of the degree of work per pass becomes difficult and the production efficiency of the rolled copper foil decreases. There is. Specifically, when the total workability of cold rolling is about 90% or more (particularly 93% or more), control of the workability per pass and the rolling work itself become rapidly difficult.

また、総加工度93％以上の冷間圧延加工を施すと、銅箔への加工ひずみの蓄積が大きく再結晶焼鈍時に銅箔の結晶粒が著しく粗大化しやすい。このような銅箔では、FPC製造工程で最近問題になっている「Dish Down現象」という不具合を生じてしまう。「Dish Down現象」とは、FPC製造工程中において銅箔をハーフエッチングする際、結晶粒単位でエッチングされる傾向があるために粒径の大きい結晶粒が優先的にエッチングされ、銅箔表面がクレーター状になり凹凸が目立ってしまう現象をいう。   Further, when cold rolling with a total working degree of 93% or more is performed, the accumulation of processing strain on the copper foil is large, and the crystal grains of the copper foil are likely to be extremely coarse during recrystallization annealing. In such a copper foil, the “Dish Down phenomenon” which has been a problem recently in the FPC manufacturing process is caused. The “Dish Down phenomenon” means that when a copper foil is half-etched during the FPC manufacturing process, the crystal grain with a large grain size is preferentially etched because there is a tendency to be etched in units of crystal grains, and the copper foil surface is It is a phenomenon that becomes crater-like and the unevenness becomes conspicuous.

一方、近年、電子機器類の小型化、高集積化（高密度実装化）や高性能化等の進展に伴い、FPCには従来よりも更なる高屈曲特性の要求が益々高まってきている。FPCの屈曲特性は実質的に銅箔のそれによって決まるため、要求を満たすためには銅箔の屈曲特性を更に向上させることが必須である。また、電子部品に対する低コスト化の要求は強まる一方である。   On the other hand, in recent years, with the progress of downsizing, high integration (high density mounting), high performance, etc. of electronic devices, demands for higher bending characteristics than ever are increasing. Since the bending characteristics of the FPC are substantially determined by that of the copper foil, it is essential to further improve the bending characteristics of the copper foil in order to satisfy the requirements. In addition, there is an increasing demand for cost reduction of electronic components.

従って、本発明の目的は、フレキシブルプリント配線板（FPC）等の可撓性配線部材に適しており、優れた屈曲特性を有する圧延銅箔を提供することにある。さらには、最終冷間圧延工程において従来のような高い総加工度を実施しなくても高屈曲特性を有する圧延銅箔を安定して効率良く製造できる、すなわち低コストな圧延銅箔を提供することにある。   Accordingly, an object of the present invention is to provide a rolled copper foil which is suitable for a flexible wiring member such as a flexible printed wiring board (FPC) and has excellent bending characteristics. Furthermore, it is possible to stably and efficiently produce a rolled copper foil having a high bending property without performing a high total workability as in the prior art in the final cold rolling process, that is, to provide a low-cost rolled copper foil. There is.

本発明者らは、圧延銅箔における金属結晶学的な詳細検討を行い、生地焼鈍の後で最終冷間圧延工程前の圧延銅箔および最終冷間圧延工程の後で再結晶焼鈍前の圧延銅箔における結晶粒の方位・配向状態が、再結晶焼鈍後の結晶粒配向状態および銅箔の屈曲特性との間に特定の相関関係を有することを見出した。また、その現象がこれまで考えられていた原理と異なる現象と思われることを見出したことに基づき、本発明を完成した（詳細は後述する）。   The present inventors have made detailed metallographic studies on rolled copper foil, rolled copper foil after dough annealing and before the final cold rolling step, and rolling before recrystallization annealing after the final cold rolling step It has been found that the orientation and orientation state of crystal grains in the copper foil have a specific correlation between the crystal grain orientation state after recrystallization annealing and the bending characteristics of the copper foil. Further, the present invention has been completed based on the finding that the phenomenon seems to be a phenomenon different from the previously considered principle (details will be described later).

本発明は、上記目的を達成するため、最終冷間圧延工程の後で再結晶焼鈍前の圧延銅箔であって、前記圧延銅箔は酸素含有量が300ppm以下である純銅からなり、圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度＝45°におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークがβ角度の少なくとも90±５°毎に存在して４回対称性を示す結晶粒が存在することを特徴とする圧延銅箔を提供する。なお、本発明における純銅とは、JIS H3100規格における「純銅」（例えば、タフピッチ銅や無酸素銅）と同等以上の銅純度（99.9％以上）を有する希薄銅合金を含むものとする。 In order to achieve the above object, the present invention is a rolled copper foil after the final cold rolling process and before recrystallization annealing, wherein the rolled copper foil is made of pure copper having an oxygen content of 300 ppm or less, and the rolled surface. The result obtained by X-ray diffraction pole figure measurement with reference to the above, and the {220} _Cu plane diffraction peak of the copper crystal obtained by β scan at the α angle = 45 ° of the pole figure measurement is at least 90 ± 5 ° of the β angle. There is provided a rolled copper foil characterized in that there are crystal grains which are present every time and exhibit 4-fold symmetry. The pure copper in the present invention includes a dilute copper alloy having a copper purity (99.9% or more) equal to or higher than “pure copper” (for example, tough pitch copper or oxygen-free copper) in the JIS H3100 standard.

また、本発明は、上記目的を達成するため、上記の本発明に係る圧延銅箔において、以下のような改良や変更を加えることができる。
（１）前記圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度を横軸とし各α角度におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークの規格化強度を縦軸としてグラフ表記した際に、α＝25〜35°の間に前記規格化強度の極大値Ｐが存在し、α＝40〜50°の間に前記規格化強度の極大値Ｑが存在し、α＝85〜90°の間は前記規格化強度が単調増加しており、前記極大値Ｐと前記極大値Ｑと前記α＝90°における前記規格化強度の値Ｒとが「Ｑ≦Ｐ≦Ｒ」である。
（２）前記圧延面に対するＸ線回折２θ/θ測定により得られる結果で、銅結晶の回折ピークの強度が「I_{200}Cu ≧ I_{220}Cu」であることを特徴とする圧延銅箔を提供する。
（３）前記圧延銅箔に対して温度300℃で60分間の再結晶焼鈍を施した後の圧延銅箔であって、前記圧延面で見える平均結晶粒径が30μm以下であることを特徴とする圧延銅箔を提供する。 Moreover, in order to achieve the said objective, this invention can add the following improvements and changes in the rolled copper foil which concerns on said this invention.
(1) {220} _Cu surface diffraction of copper crystals obtained by X-ray diffraction pole figure measurement based on the rolled surface, obtained by β scanning at each α angle with the α angle of the pole figure measurement as the horizontal axis When the normalized intensity of the peak is shown as a graph on the vertical axis, there is a maximum value P of the normalized intensity between α = 25 to 35 °, and the normalized intensity of the peak between α = 40 to 50 °. There is a maximum value Q, and the normalized strength monotonically increases between α = 85 and 90 °, and the normalized strength value R at the maximum value P, the maximum value Q, and α = 90 °. And “Q ≦ P ≦ R”.
(2) Rolled copper characterized in that the intensity of the diffraction peak of the copper crystal is “I _{{200} Cu} ≧ I _{{220} Cu} ” as a result of X-ray diffraction 2θ / θ measurement on the rolled surface. Provide foil.
(3) A rolled copper foil obtained by subjecting the rolled copper foil to recrystallization annealing at a temperature of 300 ° C. for 60 minutes, wherein an average crystal grain size visible on the rolled surface is 30 μm or less. A rolled copper foil is provided.

本発明によれば、フレキシブルプリント配線板（FPC）等の可撓性配線部材に適しており、優れた屈曲特性を有する圧延銅箔を提供することができる。さらには、高屈曲特性を有する圧延銅箔を安定して効率良く製造できる、すなわち低コストな圧延銅箔を提供することができる。   ADVANTAGE OF THE INVENTION According to this invention, it is suitable for flexible wiring members, such as a flexible printed wiring board (FPC), and can provide the rolled copper foil which has the outstanding bending characteristic. Furthermore, the rolled copper foil which has a high bending characteristic can be manufactured stably and efficiently, ie, a low-cost rolled copper foil can be provided.

本発明に関係する銅結晶の主な結晶面を示す模式図を図１に示す。銅の結晶構造は立方晶であることから、{２００}_Cu面と{２２０}_Cu面のなす角度は45°になる。なお、{ }は等価な面を表すものとする（図１参照）。 A schematic diagram showing main crystal planes of a copper crystal related to the present invention is shown in FIG. Since the crystal structure of copper is cubic, the angle between the {200} _Cu face and the {220} _Cu face is 45 °. Note that {} represents an equivalent surface (see FIG. 1).

図２は、Ｘ線回折（以下、XRDと表記する場合もある）における入射Ｘ線・検出器・試料・走査軸の関係を示す概略図である。以下、図２を用いてXRDによる圧延銅箔の結晶粒配向状態に関する評価方法を説明する。なお、図２における３つの走査軸は、一般的に、θ軸が試料軸、α軸があおり軸、β軸が面内回転軸と呼ばれている。また、本発明におけるＸ線回折は、すべてCu Kα線によるものとする。   FIG. 2 is a schematic diagram showing a relationship among incident X-rays, detectors, samples, and scanning axes in X-ray diffraction (hereinafter sometimes referred to as XRD). Hereafter, the evaluation method regarding the crystal grain orientation state of the rolled copper foil by XRD is demonstrated using FIG. Note that the three scanning axes in FIG. 2 are generally called a sample axis, an α axis having a θ axis, and a β axis being an in-plane rotation axis. Further, all X-ray diffraction in the present invention is based on Cu Kα rays.

入射Ｘ線に対して、試料と検出器をθ軸で走査し、試料の走査角をθ、検出器の走査角を２θで走査する測定方法を２θ/θ測定という。２θ/θ測定による回折ピークの強度よって、多結晶体である圧延銅箔の試料面（本発明では圧延面）において、どの結晶面が優勢であるのかを評価できる。   A measurement method in which a sample and a detector are scanned with respect to incident X-rays along the θ axis, the scanning angle of the sample is scanned with θ, and the scanning angle of the detector is scanned with 2θ is called 2θ / θ measurement. Based on the intensity of the diffraction peak by 2θ / θ measurement, it is possible to evaluate which crystal plane is dominant on the sample surface (rolled surface in the present invention) of a rolled copper foil that is a polycrystalline body.

極点図測定の特徴を利用した評価方法の１つに面内配向測定がある。これは、着目した{ｈｋｌ}_Cu面と幾何学的に対応する結晶面{ｈ'ｋ'ｌ'}_Cuが該{ｈｋｌ}_Cu面となす角度をα'とした場合、「α＝９０−α'」となるようにα軸走査し（試料を傾け）、{ｈ'ｋ'ｌ'}_Cu面の２θ値に対して（検出器の走査角２θを固定して）、試料をβ軸走査（０〜360°まで面内回転（自転））させる測定方法である。この測定による{ｈ'ｋ'ｌ'}_Cu面ピークの半価幅または積分幅で、{ｈ'ｋ'ｌ'}_Cu面と幾何学的に対応する{ｈｋｌ}_Cu面の圧延面内２軸方向の配向度が評価できる。このとき、前述と同様に、該回折ピークの半価幅または積分幅の値が小さいほど圧延面内方向の結晶配向性に優れているといえる（以下、「圧延面内方向の結晶配向性」を「面内配向性」と称する）。なお、本発明のXRD極点図測定では、試料面に垂直な方向をα＝90°と定義し、測定の基準とする。また、極点図測定には、反射法（α＝15〜90°）と透過法（α＝０〜15°）があるが、本発明における極点図測定は、反射法（α＝15〜90°）のみの測定を考慮する。 One of evaluation methods using the characteristics of pole figure measurement is in-plane orientation measurement. This is because when the angle between the {hkl} _Cu plane of interest and the crystal plane {h'k'l '} _Cu geometrically corresponding to the {hkl} _Cu plane is α ′, “α = 90− alpha '' become as alpha axially scanning (tilting the sample), {h'k'l '} with respect to 2θ values of _Cu plane (to fix the scanning angle 2θ of the detector), the sample β axis This is a measurement method of scanning (in-plane rotation (rotation) from 0 to 360 °). 'In _Cu surface half width or integration width of a peak, {h'k'l {h'k'l}' by this measure} _Cu plane geometrically corresponding {hkl} _Cu plane of the rolling plane 2 The degree of orientation in the axial direction can be evaluated. At this time, as described above, it can be said that the smaller the half width or integral width of the diffraction peak, the better the crystal orientation in the in-rolling plane direction (hereinafter referred to as “crystalline orientation in the in-rolling plane direction”). Is referred to as “in-plane orientation”). In the XRD pole figure measurement of the present invention, the direction perpendicular to the sample surface is defined as α = 90 °, which is used as a measurement reference. The pole figure measurement includes a reflection method (α = 15 to 90 °) and a transmission method (α = 0 to 15 °). The pole figure measurement in the present invention is performed by the reflection method (α = 15 to 90 °). ) Only the measurement is considered.

〔本発明の第１の実施形態〕
（面内配向測定）
本実施の形態における圧延銅箔は、最終冷間圧延工程の後で再結晶焼鈍前の圧延銅箔であって、前記圧延銅箔は酸素含有量が300ppm以下である純銅からなり、圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度＝45°におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークがβ角度の少なくとも90±５°毎に存在して４回対称性を示すことを特徴とする。例えば、極点図測定において銅箔の圧延方向をβ＝０°とした場合、４回対称の回折ピークの中心はそれぞれβ＝０±５°（360±５°）, 90±５°, 180±５°, 270±５°となる。 [First embodiment of the present invention]
(In-plane orientation measurement)
The rolled copper foil in the present embodiment is a rolled copper foil after the final cold rolling process and before recrystallization annealing, and the rolled copper foil is made of pure copper having an oxygen content of 300 ppm or less, and the rolled surface is The result obtained by the X-ray diffraction pole figure measurement as a reference, and the {220} _Cu plane diffraction peak of the copper crystal obtained by β scan at the α angle = 45 ° of the pole figure measurement is at least every 90 ± 5 ° of the β angle. And exhibits four-fold symmetry. For example, in the pole figure measurement, when the rolling direction of copper foil is β = 0 °, the centers of the four-fold diffraction peaks are β = 0 ± 5 ° (360 ± 5 °), 90 ± 5 °, 180 ±, respectively. 5 ° and 270 ± 5 °.

上述の面内配向測定結果において、{２２０}_Cu面回折ピークが90±５°毎の４回対称性を示さない場合、再結晶焼鈍を施しても高屈曲特性を有する圧延銅箔が得られない。よって、上記のように規定する。なお、極点図測定のα角度＝45°においてβ走査で得られる銅結晶の{２２０}_Cu面回折ピークが90±５°毎の４回対称性を示すということは、該{２２０}_Cu面と結晶幾何学的に45°の角度をなす{２００}_Cu面が銅箔の圧延面で面内配向していることを意味する。また、当該４回対称性の回折ピークは、それぞれの回折ピーク強度がβ軸走査（０〜360°までの面内回転）で得られる{２２０}_Cu面回折の最小強度に対して1.5倍以上を有することが望ましい。 In the above in-plane orientation measurement results, when the {220} _Cu plane diffraction peak does not show the 4-fold symmetry every 90 ± 5 °, a rolled copper foil having high bending properties can be obtained even if recrystallization annealing is performed. Absent. Therefore, it is defined as described above. It should be noted that the {220} _Cu plane diffraction peak of the copper crystal obtained by β scanning at the α angle = 45 ° of the pole figure measurement shows the 4-fold symmetry every 90 ± 5 ° indicates that the {220} _Cu plane The {200} _Cu plane, which forms an angle of 45 ° with respect to the crystal geometry, means that the in-plane orientation is in the rolled plane of the copper foil. In addition, the diffraction peak of the 4-fold symmetry is 1.5 times or more than the minimum intensity of {220} _Cu- plane diffraction, where each diffraction peak intensity is obtained by β-axis scanning (in-plane rotation from 0 to 360 °). It is desirable to have

〔本発明の第２の実施形態〕
（規格化強度）
本実施の形態における圧延銅箔は、最終冷間圧延工程の後で再結晶焼鈍前の圧延銅箔であって、前記圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度を横軸とし各α角度におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークの規格化強度を縦軸としてグラフ表記した際に、α＝25〜35°の間に前記規格化強度の極大値Ｐが存在し、α＝40〜50°の間に前記規格化強度の極大値Ｑが存在し、α＝85〜90°の間は前記規格化強度が単調増加しており、前記極大値Ｐと前記極大値Ｑと前記α＝90°における前記規格化強度の値Ｒとが「Ｑ≦Ｐ≦Ｒ」であることを特徴とする。上述のXRD極点図測定の結果において、{２２０}_Cu面回折ピークの規格化強度がα＝25〜35°の極大値Ｐとα＝40〜50°の極大値Ｑとα＝85〜90°の単調増加とを示さず、前記極大値Ｐと前記極大値Ｑと前記α＝90°における規格化強度の値Ｒとが「Ｑ≦Ｐ≦Ｒ」の関係を示さない場合、再結晶焼鈍を施しても高屈曲特性を有する圧延銅箔が得られない。よって、上記のように規定する。 [Second Embodiment of the Present Invention]
(Standardized strength)
The rolled copper foil in the present embodiment is a rolled copper foil after the final cold rolling process and before recrystallization annealing, and is a result obtained by X-ray diffraction pole figure measurement based on the rolled surface. When graphed with the normalized intensity of the {220} _Cu- plane diffraction peak of the copper crystal obtained by β scanning at each α angle as the abscissa and α = 25 to 35 ° There is a maximum value P of the normalized strength, and there is a maximum value Q of the standardized strength between α = 40 to 50 °, and the normalized strength increases monotonously between α = 85 to 90 °. The maximum value P, the maximum value Q, and the normalized strength value R at α = 90 ° satisfy “Q ≦ P ≦ R”. As a result of the above XRD pole figure measurement, the normalized intensity of the {220} _Cu plane diffraction peak is a maximum value P of α = 25 to 35 °, a maximum value Q of α = 40 to 50 °, and α = 85 to 90 °. If the maximum value P, the maximum value Q, and the normalized strength value R at α = 90 ° do not show the relationship of “Q ≦ P ≦ R”, the recrystallization annealing is not performed. Even if applied, a rolled copper foil having high bending properties cannot be obtained. Therefore, it is defined as described above.

なお、規格化強度Ｒ_ｃとは、XRD極点図測定において、各α角度におけるβ軸走査（面内回転軸走査）による所定の{ｈｋｌ}_Cu回折ピーク強度を平均化したカウント数であり、次式（詳細は下記文献を参照）により算出することができる。なお、規格化の計算は通常コンピューターで実施される。また、XRDピーク強度を規格化して用いる理由は、XRD測定の際の管電圧や管電流などの条件設定の違いによる影響をなくして比較できるようにするためである（実質的に装置依存性がなくなる）。
Ｒ_ｃ＝Ｉ_ｃ / Ｉ_std
ここで、
Ｉ_ｃ：補正強度（バックグラウンド補正、吸収補正）
Ｉ_std：計算で求めた規格化するための強度
である。
（文献名）「RAD システム応用ソフトウェア 集合組織解析プログラム 取扱説明書（説明書番号：MJ201RE）」，理学電機株式会社，ｐ．22〜23．
（文献名）「CN9258E101 RINT2000シリーズ アプリケーションソフトウェア 正極点 取扱説明書（説明書番号：MJ10102A01）」理学電機株式会社，ｐ．８〜10． Note that the normalized intensity R _c is a count number obtained by averaging predetermined {hkl} _Cu diffraction peak intensities by β-axis scanning (in-plane rotation axis scanning) at each α angle in the XRD pole figure measurement. It can be calculated by an equation (refer to the following document for details). The normalization calculation is usually performed by a computer. The reason for using the standardized XRD peak intensity is to allow comparison without the influence of differences in conditions such as tube voltage and tube current during XRD measurement. Disappear).
R _c = I _c / I _std
here,
I _c : correction intensity (background correction, absorption correction)
I _std : strength for normalization obtained by calculation.
(Literature name) “RAD system application software texture analysis program instruction manual (manual number: MJ201RE)”, Rigaku Corporation, p. 22-23.
(Literature name) “CN9258E101 RINT2000 Series Application Software Positive Point Instruction Manual (manual number: MJ10102A01)” Rigaku Corporation, p. 8-10.

〔本発明の第３の実施形態〕
（２θ/θ測定）
本実施の形態における圧延銅箔は、最終冷間圧延工程の後で再結晶焼鈍前の状態において、前記圧延面に対するＸ線回折２θ/θ測定により得られる結果で、銅結晶の回折ピークの強度Ｉが「I_{200}Cu ≧ I_{220}Cu」であることを特徴とする。 [Third embodiment of the present invention]
(2θ / θ measurement)
The rolled copper foil in the present embodiment is a result obtained by X-ray diffraction 2θ / θ measurement on the rolled surface in the state after the final cold rolling process and before recrystallization annealing, and the intensity of the diffraction peak of the copper crystal. I is characterized by “I _{{200} Cu} ≧ I _{{220} Cu} ”.

前述したように本発明に係る圧延銅箔は、最終冷間圧延工程の後で再結晶焼鈍前の状態において、{２００}_Cu面が銅箔の圧延面で配向している。このことは、多結晶体である銅箔の圧延面に{２００}_Cu面配向した結晶粒が相当量存在することを意味する。図３は、本発明に係る圧延銅箔において、最終冷間圧延工程の後かつ再結晶焼鈍前の状態で、圧延面に対してＸ線回折２θ/θ測定を行った結果の１例である。 As described above, in the rolled copper foil according to the present invention, the {200} _Cu plane is oriented with the rolled surface of the copper foil in the state after the final cold rolling step and before the recrystallization annealing. This means that a considerable amount of {200} _Cu face-oriented crystal grains are present on the rolled surface of the copper foil which is a polycrystal. FIG. 3 is an example of the result of X-ray diffraction 2θ / θ measurement performed on the rolled surface in the rolled copper foil according to the present invention after the final cold rolling step and before recrystallization annealing. .

図３から明らかなように、圧延面は{２００}_Cu面の回折ピーク強度I_{200}Cuが{２２０}_Cu面の回折ピーク強度I_{220}Cuよりも強く、{２００}_Cu面配向した結晶粒が多く存在していることを示している。銅箔の圧延面において{２００}_Cu面が強く配向していないと、再結晶焼鈍を施しても高屈曲特性を有する圧延銅箔が得られない。よって、上記のように規定する。 As apparent from FIG. 3, the rolled surface is {200} diffraction peak of _Cu plane intensity I _{{200} Cu} is {220} diffraction peak intensity I _{220} of the _Cu surface stronger than _Cu, the {200} _Cu plane orientation This shows that there are many crystal grains. If the {200} _Cu surface is not strongly oriented on the rolled surface of the copper foil, a rolled copper foil having high bending properties cannot be obtained even if recrystallization annealing is performed. Therefore, it is defined as described above.

〔圧延銅箔の製造方法〕
次に、図４を参照しながら、本発明に係る圧延銅箔の製造方法を説明する。図４は、本発明に係る圧延銅箔の製造工程の１例を示すフロー図である。 [Method for producing rolled copper foil]
Next, the manufacturing method of the rolled copper foil which concerns on this invention is demonstrated, referring FIG. FIG. 4 is a flow diagram showing an example of a process for producing a rolled copper foil according to the present invention.

はじめに、原材料となる酸素含有量が300ppm以下である純銅のインゴット（鋳塊）を用意する（工程ａ）。次に、熱間圧延を行う熱間圧延工程（工程ｂ）を行う。熱間圧延工程の後、冷間圧延を行う冷間圧延工程（工程ｃ）と冷間圧延による加工硬化を緩和する中間焼鈍工程（工程ｄ）とを適宜繰り返し行うことにより「生地」と呼ばれる銅条が製造される。次に、生地焼鈍工程（工程ｄ’）が行われる。生地焼鈍工程においては、それ以前の加工歪が十分に緩和されること（例えば、略完全焼鈍）が望ましい。   First, a pure copper ingot (ingot) having an oxygen content of 300 ppm or less as a raw material is prepared (step a). Next, the hot rolling process (process b) which performs hot rolling is performed. After the hot rolling process, a copper called “dough” is obtained by appropriately repeating a cold rolling process (process c) for performing cold rolling and an intermediate annealing process (process d) for relaxing work hardening by cold rolling. Articles are manufactured. Next, a dough annealing step (step d ') is performed. In the dough annealing process, it is desirable that the previous processing strain is sufficiently relaxed (for example, substantially complete annealing).

その後、焼鈍した「生地」（「焼鈍生地」と称す）に対して最終冷間圧延工程（工程ｅ、「仕上げ圧延工程」と称される場合もある）を施して、所定厚さの圧延銅箔（「仕上げ銅箔」と称する場合もある）が製造される。最終冷間圧延工程後の圧延銅箔は、必要に応じて表面処理等が施され（工程ｆ）、FPC製造工程（工程ｇ）に供給される。前述したように、再結晶焼鈍は工程ｇの中（例えば、CCL工程）で為されることが多い。本発明において、「最終冷間圧延工程」とは工程ｅを意味し、「再結晶焼鈍」工程とは工程ｅよりも後で実施される工程を意味するものとする。   Thereafter, the annealed “fabric” (referred to as “annealed fabric”) is subjected to a final cold rolling step (sometimes referred to as “step e” or “finish rolling step”), and rolled copper having a predetermined thickness. A foil (sometimes referred to as “finished copper foil”) is produced. The rolled copper foil after the final cold rolling process is subjected to surface treatment or the like as necessary (process f) and supplied to the FPC manufacturing process (process g). As described above, recrystallization annealing is often performed in step g (for example, CCL step). In the present invention, the “final cold rolling step” means the step e, and the “recrystallization annealing” step means a step performed after the step e.

また、本発明に係る圧延銅箔の製造方法としては、少なくとも生地焼鈍工程（工程ｄ’）を制御することによって、焼鈍生地を以下のように調整する製造方法である。生地焼鈍（工程ｄ’）の後で最終冷間圧延工程（工程ｅ）前の圧延銅箔（焼鈍生地）において、圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度を横軸とし各α角度におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークの規格化強度を縦軸としてグラフ表記した際に、α＝40〜50°の間に規格化強度の極大値Ｑが存在し、α＝20〜40°の間に規格化強度の極小値Ｓが存在し、前記極大値Ｑと前記極小値Ｓとの比が「２≦ Ｑ/Ｓ ≦３」である圧延銅箔を最終冷間圧延工程への焼鈍生地として用いる。さらに、そのような焼鈍生地に対して、総加工度が80％以上93％未満となるような最終冷間圧延工程（工程ｅ）を施す。なお、生地焼鈍条件としては、例えば、600℃以上700℃未満（銅箔の実態温度）で１〜30分間保持する条件が好ましい。より好ましい温度は650℃以上700℃未満である。 Moreover, as a manufacturing method of the rolled copper foil which concerns on this invention, it is a manufacturing method which adjusts an annealing material | dough as follows by controlling a material | dough annealing process (process d ') at least. In the rolled copper foil (annealed dough) after the dough annealing (step d ′) and before the final cold rolling step (step e), the results are obtained by X-ray diffraction pole figure measurement based on the rolling surface. The graph shows the normalized intensity of the {220} _Cu plane diffraction peak of the copper crystal obtained by β scanning at each α angle as the abscissa and α = 40 to 50 °. There is a maximum value Q of standardized strength, there is a minimum value S of standardized strength between α = 20 to 40 °, and the ratio of the maximum value Q to the minimum value S is “2 ≦ Q / S A rolled copper foil satisfying ≦ 3 ”is used as an annealed material for the final cold rolling process. Further, a final cold rolling step (step e) is performed on such an annealed dough so that the total degree of processing becomes 80% or more and less than 93%. In addition, as material | dough annealing conditions, the conditions hold | maintained for 1 to 30 minutes at 600 degreeC or more and less than 700 degreeC (actual temperature of copper foil) are preferable, for example. A more preferable temperature is 650 ° C. or higher and lower than 700 ° C.

これにより、最終冷間圧延工程（工程ｅ）の後で再結晶焼鈍前の圧延銅箔における圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度＝45°におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークが少なくともβ角度の90±５°毎に存在して４回対称性を示す結晶粒が存在し、加えて、極点図測定のα角度を横軸としβ走査で得られる銅結晶の{２２０}_Cu面回折ピークの規格化強度を縦軸としてグラフ表記した際に、α＝25〜35°の間に規格化強度の極大値Ｐが存在し、α＝40〜50°の間に規格化強度の極大値Ｑが残存し、α＝85〜90°の間は規格化強度が単調増加しており、極大値Ｐと極大値Ｑとα＝90°における規格化強度の値Ｒとが「Ｑ≦Ｐ≦Ｒ」となる本発明に係る圧延銅箔が得られる。 This is a result obtained by X-ray diffraction pole figure measurement based on the rolling surface of the rolled copper foil after the final cold rolling process (step e) and before recrystallization annealing, and the α angle of the pole figure measurement = 45 The {220} _Cu plane diffraction peak of the copper crystal obtained by β scanning at ° is present at least every 90 ± 5 ° of the β angle, and there are crystal grains exhibiting 4-fold symmetry. When the normalized intensity of the {220} _Cu plane diffraction peak of the copper crystal obtained by β-scanning with the α angle as the horizontal axis is plotted as the vertical axis, the maximum value of the normalized intensity between α = 25 to 35 ° P exists, the maximum value Q of standardized strength remains between α = 40 to 50 °, and the standardized strength increases monotonously between α = 85 to 90 °. The maximum value P and the maximum value A rolled copper foil according to the present invention in which Q and the normalized strength value R at α = 90 ° satisfy “Q ≦ P ≦ R” is obtained.

前述したように、銅結晶の{２２０}_Cu面と{２００}_Cu面とは、幾何学的に45°（両結晶面のなす角が45°）の関係にある。よって、α＝40〜50°の間にある規格化強度の極大値Ｑは、圧延銅箔の圧延面において{２００}_Cu面の結晶粒が面内配向している程度に関係していると考えられる。言い換えると、生地焼鈍（工程ｄ’）の後で最終冷間圧延工程（工程ｅ）前の生地において圧延面に存在した{２００}_Cu面配向かつ面内配向の結晶粒が、最終冷間圧延工程（工程ｅ）を経て「Ｑ≦Ｐ≦Ｒ」の関係となる程度に残存しているところに本発明の特徴がある。 As described above, the {220} _Cu plane and the {200} _Cu plane of the copper crystal have a geometrical relationship of 45 ° (the angle between both crystal planes is 45 °). Therefore, the maximum value Q of the normalized strength between α = 40 and 50 ° is related to the degree to which the crystal grains of the {200} _Cu plane are in-plane oriented on the rolled surface of the rolled copper foil. Conceivable. In other words, the {200} _Cu- plane-oriented and in-plane-oriented crystals present on the rolling surface in the dough after the dough annealing (step d ′) and before the final cold rolling step (step e) are finally cold rolled. The feature of the present invention resides in that it remains after the process (process e) to the extent that “Q ≦ P ≦ R” is satisfied.

また、最終冷間圧延工程における総加工度を80％以上93％未満とすることにより、従来の高加工度圧延銅箔に比して圧延工程の総パス数を低減することができるのに加えて、過度の加工硬化による圧延加工制御の困難性を回避でき、製造設備への負荷低減および製造の低コスト化に寄与できる。さらに、そのような圧延銅箔に再結晶焼鈍を施すと、結晶粒が過剰に粗大化することなく、圧延面で見える結晶粒度（平均結晶粒径）を30μm以下とすることができる。なお、平均結晶粒径が30μmより大きくなると、エッチングによる表面凹凸が目立つようになり「Dish Down現象」として不具合が生じる。   In addition, by setting the total workability in the final cold rolling process to 80% or more and less than 93%, the total number of passes in the rolling process can be reduced compared to conventional high-workability rolled copper foil. Thus, difficulty in controlling the rolling process due to excessive work hardening can be avoided, and the load on the manufacturing facility can be reduced and the manufacturing cost can be reduced. Further, when such a rolled copper foil is subjected to recrystallization annealing, the crystal grain size (average crystal grain size) visible on the rolled surface can be reduced to 30 μm or less without excessively coarsening the crystal grains. When the average crystal grain size is larger than 30 μm, surface irregularities due to etching become conspicuous and a problem occurs as a “Dish Down phenomenon”.

一方、本発明に係る圧延銅箔は、酸素含有量が300ppm以下のである純銅からなることを特徴とする。酸素含有量が300ppmを超えると亜酸化銅や不可避不純物の酸化物などの粒子が粗大化しやすく、該粒子が銅箔圧延中における断裂（板切れ）の原因となったり、屈曲時における亀裂の起点となったり（すなわち屈曲特性の劣化原因となったり）することから好ましくない。また、該粒子は結晶中の転位の移動や結晶の回転現象に対する阻害点となることから、前述したような望ましい結晶粒配向状態（圧延集合組織）の形成・制御が困難になる。よって、酸素含有量を300ppm以下と規定する。なお、酸素含有量が少ないほど好ましいのは言うまでも無い。   On the other hand, the rolled copper foil according to the present invention is characterized by comprising pure copper having an oxygen content of 300 ppm or less. If the oxygen content exceeds 300 ppm, particles such as cuprous oxide and oxides of inevitable impurities are likely to be coarsened, and the particles may cause tearing (sheet breakage) during copper foil rolling, or the origin of cracks during bending (That is, it may cause deterioration of the bending characteristics). In addition, since the grains serve as an inhibition point for dislocation movement and crystal rotation in the crystal, it becomes difficult to form and control the desirable crystal grain orientation state (rolling texture) as described above. Therefore, the oxygen content is defined as 300 ppm or less. Needless to say, the smaller the oxygen content, the better.

〔他の実施の形態〕
工程ａにおいて、溶解・鋳造方法に制限はなく、また、材料の寸法にも制限はない。工程ｂ、工程ｃおよび工程ｄにおいても、特段の制限はなく、通常の方法・条件でよい。また、FPCに用いる圧延銅箔の厚みは一般的に50μm以下であり、本発明の圧延銅箔の厚みも、50μm以下であれば制限はないが、20μm以下が特に好ましい。 [Other Embodiments]
In step a, the melting / casting method is not limited, and the material dimensions are not limited. There are no particular restrictions on step b, step c, and step d, and ordinary methods and conditions may be used. Moreover, the thickness of the rolled copper foil used for FPC is generally 50 μm or less, and the thickness of the rolled copper foil of the present invention is not limited as long as it is 50 μm or less, but 20 μm or less is particularly preferable.

〔フレキシブルプリント配線板の製造〕
上記実施の形態の圧延銅箔を用いて、通常行われている製造方法により、フレキシブルプリント配線板を得ることができる。また、圧延銅箔に対する再結晶焼鈍は、通常のCCL工程で行われる熱処理でもよいし、別工程で行われてもよい。 [Manufacture of flexible printed wiring boards]
A flexible printed wiring board can be obtained by the manufacturing method currently performed normally using the rolled copper foil of the said embodiment. Moreover, the recrystallization annealing for the rolled copper foil may be a heat treatment performed in a normal CCL process or may be performed in a separate process.

〔実施の形態の効果〕
上記の本発明の実施の形態によれば、下記の効果を奏する。
（１）従来よりも優れた屈曲特性を有する圧延銅箔を得ることができる。
（２）従来よりも優れた屈曲特性を有する圧延銅箔を安定して効率良く（すなわち、低コストで）製造することができる。
（３）従来よりも優れた屈曲特性を有するフレキシブルプリント配線板（FPC）等の可撓性配線を得ることができる。
（４）フレキシブルプリント配線板（FPC）のみに留まらず、高い屈曲特性（屈曲寿命）が要求される他の導電部材（例えば、耐振動性が必要な自動車用リチウムイオン電池の負極材料など）にも適用できる。 [Effect of the embodiment]
According to the above embodiment of the present invention, the following effects can be obtained.
(1) A rolled copper foil having bending properties superior to those of the conventional art can be obtained.
(2) A rolled copper foil having bending properties superior to those of conventional ones can be produced stably and efficiently (that is, at a low cost).
(3) A flexible wiring such as a flexible printed wiring board (FPC) having bending characteristics superior to those of the conventional one can be obtained.
(4) Not only flexible printed wiring boards (FPC) but also other conductive members that require high bending characteristics (flexion life) (for example, negative electrode materials for automotive lithium-ion batteries that require vibration resistance) Is also applicable.

以下、本発明を実施例に基づいて更に詳しく説明するが、本発明はこれらに限定されるものではない。   EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these.

（作製手順）
はじめに、原料素材として無酸素銅（酸素含有量３ppm）およびタフピッチ銅（酸素含有量150〜400ppm）を作製し、厚さ200 mm、幅650 mmの鋳塊を製造した（実施例１〜４および比較例１〜４、表１参照）。その後、図４記載のフローにしたがって、10 mmの厚さまで熱間圧延を行った後、冷間圧延および中間焼鈍（生地焼鈍を含む）を適宜繰り返して、0.53 mmと0.2 mmと0.1 mmの厚さを有する焼鈍生地を製造した。生地焼鈍としては、約690℃の温度で約１分間保持する熱処理（実施例１〜３および比較例１）、約650℃の温度で約２分間保持する熱処理（実施例４および比較例４）、約800℃の温度で１分間保持する熱処理（比較例２）、約550℃の温度で約２分間保持する熱処理（比較例３）を行った。なお、生地焼鈍の温度は、焼鈍炉の設定温度ではなく銅箔の実態温度である。 (Production procedure)
First, oxygen-free copper (oxygen content 3 ppm) and tough pitch copper (oxygen content 150 to 400 ppm) were produced as raw materials, and ingots having a thickness of 200 mm and a width of 650 mm were produced (Examples 1 to 4 and Comparative Examples 1 to 4 and Table 1). Then, according to the flow shown in FIG. 4, after hot rolling to a thickness of 10 mm, cold rolling and intermediate annealing (including dough annealing) are repeated as appropriate to obtain thicknesses of 0.53 mm, 0.2 mm, and 0.1 mm. An annealed fabric having a thickness was produced. As the dough annealing, heat treatment (Examples 1 to 3 and Comparative Example 1) held at a temperature of about 690 ° C. for about 1 minute, heat treatment held at a temperature of about 650 ° C. for about 2 minutes (Example 4 and Comparative Example 4) A heat treatment (Comparative Example 2) held at a temperature of about 800 ° C. for 1 minute and a heat treatment (Comparative Example 3) held at a temperature of about 550 ° C. for about 2 minutes were performed. The temperature of the fabric annealing is not the set temperature of the annealing furnace but the actual temperature of the copper foil.

つぎに、上記の焼鈍生地に対し、表１に示す条件で最終冷間圧延工程を行うことにより、厚さ16μmの圧延銅箔（実施例１〜４および比較例１〜４）を作製した。最終冷間圧延工程の総加工度は、焼鈍生地厚さの厚い方から約97％、約92％、約84％となる。








Next, a rolled copper foil (Examples 1 to 4 and Comparative Examples 1 to 4) having a thickness of 16 μm was produced by performing a final cold rolling step on the above-described annealed dough under the conditions shown in Table 1. The total degree of work in the final cold rolling process is about 97%, about 92%, and about 84% from the thicker annealed material.

（圧延銅箔に対するXRD評価）
圧延銅箔（生地焼鈍後、最終冷間圧延工程途中、最終冷間圧延工程後、再結晶焼鈍後）に対するXRD評価は次のように行った。なお、各種XRD測定には、Ｘ線回折装置（株式会社リガク製、型式：RAD−B）を用いた。対陰極（ターゲット）はCuを用い、管電圧および管電流はそれぞれ40 kV、30 mAとした。また、XRD測定に供する試料の大きさは、約15×約15 mm²とした。 (XRD evaluation for rolled copper foil)
XRD evaluation for rolled copper foil (after dough annealing, during the final cold rolling process, after the final cold rolling process, and after recrystallization annealing) was performed as follows. Note that an X-ray diffractometer (manufactured by Rigaku Corporation, model: RAD-B) was used for various XRD measurements. The counter cathode (target) was Cu, and the tube voltage and tube current were 40 kV and 30 mA, respectively. The size of the sample used for XRD measurement was about 15 × about 15 mm ² .

XRD２θ/θ測定の条件は、一般的な広角ゴニオメータを用い、２θ＝40〜100°の範囲で測定した。２θ/θ測定におけるスリット条件は、発散スリットが１°、受光スリットが0.15 mm、散乱スリットが１°とした。   The XRD 2θ / θ measurement was performed using a general wide-angle goniometer in the range of 2θ = 40 to 100 °. The slit conditions in the 2θ / θ measurement were 1 ° for the divergent slit, 0.15 mm for the light receiving slit, and 1 ° for the scattering slit.

XRD極点図測定および面内配向測定の条件は、一般的なシュルツ反射法を用い、α＝15〜90°（圧延面に垂直方向がα＝90°）の範囲でβ角度を０〜360°まで走査（自転）しながら、{２２０}_Cu面の回折強度を測定した（２θ≒74°で、２θ値は試料毎に予備測定した結果を用いた）。このときのスリット条件は、発散スリット＝１°、散乱スリット＝７mm、受光スリット＝７mmおよびシュルツスリット（スリット高さ１mm）を用いた。なお、面内配向測定はα＝45°に固定して行った。 The conditions for XRD pole figure measurement and in-plane orientation measurement are the general Schulz reflection method, and the β angle is 0 to 360 ° within the range of α = 15 to 90 ° (α = 90 ° perpendicular to the rolling surface). The diffraction intensity of the {220} _Cu surface was measured while scanning (spinning) until 2θ was about 74 ° (2θ value was obtained by using the result of preliminary measurement for each sample). The slit conditions at this time were diverging slit = 1 °, scattering slit = 7 mm, light receiving slit = 7 mm, and Schulz slit (slit height 1 mm). The in-plane orientation measurement was performed with α = 45 ° fixed.

（再結晶焼鈍後の圧延銅箔の屈曲特性）
上記のようにして作製した各仕上げ銅箔（実施例１〜４および比較例１〜４、厚さ16μm、最終冷間圧延工程上がり）に対し、温度300℃で60分間保持する再結晶焼鈍を施した。再結晶焼鈍後の各圧延銅箔に対する屈曲特性の評価は、次のように行った。図５は、屈曲特性評価（摺動屈曲試験）の概略を表した模式図である。摺動屈曲試験装置は信越エンジニアリング株式会社製、型式：SEK−31B2Sを用い、Ｒ＝2.5 mm、振幅ストローク＝10 mm、周波数＝25 Hz（振幅速度＝1500回/分）、試料幅＝12.5 mm、試料長さ＝220 mm、試料片の長手方向が圧延方向となる条件で測定した。測定は10試料ずつ行った。 (Bending characteristics of rolled copper foil after recrystallization annealing)
For each finished copper foil (Examples 1 to 4 and Comparative Examples 1 to 4, thickness 16 μm, final cold rolling process completed) produced as described above, recrystallization annealing is performed at a temperature of 300 ° C. for 60 minutes. gave. Evaluation of the bending characteristic with respect to each rolled copper foil after recrystallization annealing was performed as follows. FIG. 5 is a schematic diagram showing an outline of bending characteristic evaluation (sliding bending test). Sliding and bending test equipment manufactured by Shin-Etsu Engineering Co., Ltd., model: SEK-31B2S, R = 2.5 mm, amplitude stroke = 10 mm, frequency = 25 Hz (amplitude velocity = 1500 times / min), sample width = 12.5 mm The sample length was 220 mm, and the measurement was performed under the condition that the longitudinal direction of the sample piece was the rolling direction. Measurement was performed for 10 samples.

（再結晶焼鈍後の圧延銅箔の結晶粒径測定）
上記のようにして作製した再結晶焼鈍後の各圧延銅箔（実施例１〜４および比較例１〜４、厚さ16μm）に対する結晶粒径の測定は、次のように行った。電子後方散乱パターン（EBSP, Electron Backscattering Pattern）法を用いて圧延銅箔の圧延面における結晶方位マップを測定した。このとき、隣接する２測定点間の方位差が５°以上ある場合に「該２測定点間に結晶粒界が存在する」と見なした。言い換えると、隣接する２測定点間の方位差が５°より小さい場合は、「該２測定点が同じ結晶粒内に存在する」と見なした。得られた結晶方位マップに対し、一般的な切断法（任意の場所に既知の長さの線分を引き、これを横切る結晶粒界の数で当該線分の長さを除して結晶粒径を求める方法）を用いて平均結晶粒径を測定した。 (Measurement of crystal grain size of rolled copper foil after recrystallization annealing)
The crystal grain size of each rolled copper foil (Examples 1 to 4 and Comparative Examples 1 to 4 and thickness 16 μm) after recrystallization annealing produced as described above was measured as follows. The crystal orientation map on the rolled surface of the rolled copper foil was measured using an electron backscattering pattern (EBSP) method. At this time, when there was an orientation difference of 5 ° or more between two adjacent measurement points, it was considered that “a crystal grain boundary exists between the two measurement points”. In other words, when the orientation difference between two adjacent measurement points was smaller than 5 °, it was considered that “the two measurement points existed in the same crystal grain”. For the obtained crystal orientation map, a general cutting method (a line segment of a known length is drawn at an arbitrary location, and the length of the line segment is divided by the number of crystal grain boundaries crossing the crystal segment to obtain crystal grains. The average crystal grain size was measured using a method for determining the diameter.

（実施例および比較例における測定・評価結果）
実施例および比較例における測定・評価結果を酸素含有量および最終冷間圧延工程の総加工度とともに表２に示す。 (Measurement / evaluation results in Examples and Comparative Examples)
The measurement and evaluation results in the examples and comparative examples are shown in Table 2 together with the oxygen content and the total degree of work in the final cold rolling process.

図６は、最終冷間圧延工程上がりの圧延銅箔（仕上げ銅箔）に対して面内配向測定（α＝45°における{２２０}_Cu面の測定）を行った結果の1例である。図６(ａ)は実施例２における測定結果であり、図６(ｂ)は比較例２における測定結果である。図６から判るように、実施例２の圧延銅箔は90±５°毎に存在する４回対称性の回折ピーク（黒矢印で示す）が認められる。これは、銅箔の圧延面で{２００}_Cu面が良好な面内配向性を有していることを意味している。これに対し、比較例２の圧延銅箔では、β≒０°(360°)，180°に弱い回折ピークが見られるものの、β≒90°，270°には回折ピークがほとんど認められない。 FIG. 6 shows an example of the result of in-plane orientation measurement (measurement of {220} _Cu plane at α = 45 °) for the rolled copper foil (finished copper foil) after the final cold rolling process. 6A shows the measurement result in Example 2, and FIG. 6B shows the measurement result in Comparative Example 2. As can be seen from FIG. 6, the rolled copper foil of Example 2 has four-fold symmetry diffraction peaks (indicated by black arrows) that exist every 90 ± 5 °. This means that the {200} _Cu surface has a good in-plane orientation on the rolled surface of the copper foil. In contrast, the rolled copper foil of Comparative Example 2 shows weak diffraction peaks at β≈0 ° (360 °) and 180 °, but almost no diffraction peaks are observed at β≈90 ° and 270 °.

また、実施例１，３，４においても図６(ａ)と同様な４回対称性の回折ピークが認められた。一方、比較例２，４は図６(ｂ)と同様に４回対称性の回折ピークが認められなかった。なお、酸素含有量の多い比較例１では、最終冷間圧延工程の途中のパスで板切れが生じてしまい、仕上げ銅箔（厚さ16μm）まで作製することができなかった。   In Examples 1, 3, and 4, the same 4-fold symmetry diffraction peak as in FIG. 6A was observed. On the other hand, in Comparative Examples 2 and 4, a 4-fold symmetry diffraction peak was not recognized as in FIG. In Comparative Example 1 having a high oxygen content, a plate breakage occurred during a pass in the final cold rolling process, and it was not possible to produce a finished copper foil (thickness: 16 μm).

前述した図３は、実施例２における仕上げ銅箔に対して２θ/θ測定を行った結果である。前述したように、実施例２の圧延銅箔は、{２００}_Cu面配向した結晶粒が圧延面で多く存在していることを示し、{２００}_Cu面の回折ピーク強度I_{200}Cuが{２２０}_Cu面の回折ピーク強度I_{220}Cuよりも強く現れている（I_{200}Cu ≧ I_{220}Cu）。また、実施例１，３，４においても図３と同様に「I_{200}Cu ≧ I_{220}Cu」の関係にあった。これに対し、比較例２〜４の仕上げ銅箔では「I_{200}Cu ＜ I_{220}Cu」の関係にあり、{２２０}_Cu面配向の結晶粒の方が{２００}_Cu面配向の結晶粒よりも銅箔の圧延面で圧倒的に優勢であった。言い換えると、{２００}_Cu面配向の結晶粒が非常に少ないと言えた。 FIG. 3 described above is a result of 2θ / θ measurement performed on the finished copper foil in Example 2. As described above, the rolled copper foil of Example 2 shows that there are many {200} _Cu face-oriented crystal grains on the rolled face, and the diffraction peak intensity I _{{200} Cu on the} {200} _Cu face. _Appears stronger than the diffraction peak intensity I _{{220} Cu} on the {220} _Cu surface (I _{{200} Cu} ≧ I _{{220} Cu} ). Further, in Examples 1, 3, and 4, the relationship “I _{{200} Cu} ≧ I _{{220} Cu} ” was established as in FIG. 3. On the other hand, the finished copper foils of Comparative Examples 2 to 4 have a relationship of “I _{{200} Cu} <I _{{220} Cu} ”, and the {220} _Cu face orientation crystal grains are {200} _Cu face orientation. It was overwhelmingly dominant on the rolled surface of the copper foil than the crystal grains. In other words, it can be said that there are very few {200} _Cu plane oriented grains.

図７は、最終冷間圧延工程上がりの圧延銅箔（仕上げ銅箔）に対して{２２０}_Cu面のXRD極点図測定を行った結果の1例である。図７(ａ)は実施例４、図７(ｂ)は実施例２、図７(ｃ)は比較例３、図７(ｄ)は比較例２、図７(ｅ)は比較例４である。図７から判るように、実施例２と実施例４の圧延銅箔は「Ｑ≦Ｐ≦Ｒ」の関係になっているが、比較例３の圧延銅箔は「Ｑ＞Ｐ，Ｑ＞Ｒ」となっており、比較例２，４の圧延銅箔では極大値Ｑがほとんど検出されない。また、実施例１，３は図７(ｂ)と同様な結果が得られた。 FIG. 7 is an example of the result of XRD pole figure measurement of {220} _Cu surface for the rolled copper foil (finished copper foil) after the final cold rolling process. 7A is Example 4, FIG. 7B is Example 2, FIG. 7C is Comparative Example 3, FIG. 7D is Comparative Example 2, and FIG. 7E is Comparative Example 4. is there. As can be seen from FIG. 7, the rolled copper foils of Example 2 and Example 4 have a relationship of “Q ≦ P ≦ R”, but the rolled copper foil of Comparative Example 3 has “Q> P, Q> R”. In the rolled copper foils of Comparative Examples 2 and 4, the maximum value Q is hardly detected. In Examples 1 and 3, the same results as in FIG. 7B were obtained.

「Ｑ≦Ｐ≦Ｒ」の関係とは、面内配向した立方体組織の種結晶（{２００}_Cu面配向している結晶粒）が適度な量で存在し、加工ひずみを蓄積した圧延集合組織が必要十分な量で存在していることを意味していると考えられる。これに対し、極大値Ｑがほとんど検出されなかった比較例２，４は、面内配向した立方体組織の種結晶がほとんど無いことを示唆している。また、「Ｑ＞Ｐ，Ｑ＞Ｒ」である比較例３では、面内配向した立方体組織の銅結晶が存在すると考えられるが、加工ひずみを蓄積した圧延集合組織の形成が不十分であることを示唆している。 The relationship of “Q ≦ P ≦ R” is that the in-plane oriented cubic structure seed crystal ({200} _Cu plane oriented crystal grains) is present in an appropriate amount and the rolling texture in which processing strain is accumulated. Is considered to be present in a necessary and sufficient amount. On the other hand, Comparative Examples 2 and 4 in which the maximum value Q was hardly detected suggest that there are almost no in-plane oriented seed crystals of the cubic structure. Further, in Comparative Example 3 where “Q> P, Q> R”, it is considered that in-plane oriented copper crystals of a cubic structure exist, but the formation of a rolling texture with accumulated work strain is insufficient. It suggests.

以上の結果から判るように、仕上げ銅箔の段階における面内配向測定で{２２０}_Cu面が４回対称性の回折ピークを示し、２θ/θ測定で「I_{200}Cu ≧ I_{220}Cu」の関係を有し、極点図測定で「Ｑ≦Ｐ≦Ｒ」の関係を有している実施例１〜４の圧延銅箔は高い屈曲特性を示すことが確認された（表２参照）。なお、比較例５の圧延銅箔は、良好な屈曲特性を示していたが、最終冷間圧延工程の総加工度が非常に高いことから再結晶焼鈍後の平均結晶粒径が120μmと極端に大きくなっていた。このような大きな結晶粒は、前述した「Dish Down現象」につながる不具合がある。これに対し、本発明に係る圧延銅箔（実施例１〜４）は、平均粒径が15〜18μmと粗大化が抑制されており、「Dish Down現象」が抑制される効果もあると言える。 As can be seen from the above results, the {220} _Cu plane shows a four-fold diffraction peak in the in-plane orientation measurement at the finished copper foil stage, and “I _{{200} Cu} ≧ I _{220 ” in the 2θ / θ measurement. It is confirmed that the rolled copper foils of Examples 1 to 4 having a relationship of “ _Cu ” and having a relationship of “Q ≦ P ≦ R” by pole figure measurement exhibit high bending properties (Table 2). reference). In addition, although the rolled copper foil of Comparative Example 5 showed good bending characteristics, the average crystal grain size after recrystallization annealing was extremely high at 120 μm because the total degree of work in the final cold rolling process was very high. It was getting bigger. Such large crystal grains have a defect that leads to the “Dish Down phenomenon” described above. In contrast, the rolled copper foils (Examples 1 to 4) according to the present invention have an average particle size of 15 to 18 μm and are suppressed from being coarsened, and can also be said to have an effect of suppressing the “Dish Down phenomenon”. .

本発明に関係する銅結晶の主な結晶面を示す模式図である。It is a schematic diagram which shows the main crystal planes of the copper crystal relevant to this invention. Ｘ線回折における入射Ｘ線・検出器・試料・走査軸の関係を示す概略図である。It is the schematic which shows the relationship of the incident X-ray in X-ray diffraction, a detector, a sample, and a scanning axis. 本発明に係る圧延銅箔において、最終冷間圧延工程の後かつ再結晶焼鈍前の状態で、圧延面に対してＸ線回折２θ/θ測定を行った結果の１例である。In the rolled copper foil which concerns on this invention, it is an example of the result of having performed X-ray diffraction 2 (theta) / (theta) measurement with respect to the rolling surface in the state after a final cold rolling process and before recrystallization annealing. 本発明に係る圧延銅箔の製造工程の１例を示すフロー図である。It is a flowchart which shows one example of the manufacturing process of the rolled copper foil which concerns on this invention. 屈曲特性評価（摺動屈曲試験）の概略を表した模式図である。It is a schematic diagram showing the outline of bending characteristic evaluation (sliding bending test). 最終冷間圧延工程上がりの圧延銅箔に対して面内配向測定（α＝45°における{２２０}_Cu面の測定）を行った結果の1例であり、図６(ａ)は実施例２、図６(ｂ)は比較例２である。FIG. 6A is an example of the result of in-plane orientation measurement (measurement of {220} _Cu surface at α = 45 °) on the rolled copper foil after the final cold rolling process. FIG. 6B shows a comparative example 2. 最終冷間圧延工程上がりの圧延銅箔に対して{２２０}_Cu面のXRD極点図測定を行った結果の1例であり、図７(ａ)は実施例４、図７(ｂ)は実施例２、図７(ｃ)は比較例３、図７(ｄ)は比較例２、図７(ｅ)は比較例４である。FIG. 7 (a) shows an example of the results of XRD pole figure measurement of {220} _Cu surface on the rolled copper foil after the final cold rolling process, and FIG. 7 (b) shows an example. Example 2, FIG. 7 (c) is Comparative Example 3, FIG. 7 (d) is Comparative Example 2, and FIG. 7 (e) is Comparative Example 4.

符号の説明Explanation of symbols

１…銅箔、２…試料固定板、２ａ…ねじ、３…振動伝達部、４…発振駆動体、
Ｒ…曲率。 DESCRIPTION OF SYMBOLS 1 ... Copper foil, 2 ... Sample fixing plate, 2a ... Screw, 3 ... Vibration transmission part, 4 ... Oscillation drive body,
R: Curvature.

Claims (4)

最終冷間圧延工程の後で再結晶焼鈍前の圧延銅箔であって、
前記圧延銅箔は酸素含有量が300ppm以下である純銅からなり、
圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度＝45°におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークが少なくともβ角度の90±５°毎に存在して４回対称性を示す結晶粒が存在することを特徴とする圧延銅箔。 A rolled copper foil after the final cold rolling process and before recrystallization annealing,
The rolled copper foil is made of pure copper having an oxygen content of 300 ppm or less,
The result obtained by X-ray diffraction pole figure measurement based on the rolling surface shows that the {220} _Cu plane diffraction peak of the copper crystal obtained by β scanning at the α angle = 45 ° of the pole figure measurement is at least 90 ± of the β angle. A rolled copper foil characterized in that there are crystal grains present every 5 ° and exhibiting 4-fold symmetry. 請求項１に記載の圧延銅箔において、
前記圧延面を基準としたＸ線回折極点図測定により得られる結果で、極点図測定のα角度を横軸とし各α角度におけるβ走査で得られる銅結晶の{２２０}_Cu面回折ピークの規格化強度を縦軸としてグラフ表記した際に、
α＝25〜35°の間に前記規格化強度の極大値Ｐが存在し、α＝40〜50°の間に前記規格化強度の極大値Ｑが存在し、α＝85〜90°の間は前記規格化強度が単調増加しており、
前記極大値Ｐと前記極大値Ｑと前記α＝90°における前記規格化強度の値Ｒとが「Ｑ≦Ｐ≦Ｒ」であることを特徴とする圧延銅箔。 In the rolled copper foil according to claim 1,
The result obtained by X-ray diffraction pole figure measurement based on the rolling surface, and the standard of {220} _Cu plane diffraction peak of copper crystal obtained by β scanning at each α angle with the α angle of the pole figure measurement as the horizontal axis When the graphed strength is plotted on the vertical axis,
The maximum value P of the normalized strength exists between α = 25 to 35 °, the maximum value Q of the normalized strength exists between α = 40 to 50 °, and between α = 85 to 90 ° The normalized strength is monotonically increasing,
The rolled copper foil, wherein the maximum value P, the maximum value Q, and the normalized strength value R at α = 90 ° are “Q ≦ P ≦ R”. 請求項１または請求項２に記載の圧延銅箔において、
前記圧延面に対するＸ線回折２θ/θ測定により得られる結果で、銅結晶の回折ピークの強度が「I_{200}Cu ≧ I_{220}Cu」であることを特徴とする圧延銅箔。 In the rolled copper foil of Claim 1 or Claim 2,
A rolled copper foil characterized in that the intensity of a diffraction peak of a copper crystal is “I _{{200} Cu} ≧ I _{{220} Cu} ” as a result obtained by X-ray diffraction 2θ / θ measurement on the rolled surface. 請求項１乃至請求項３のいずれか１項に記載の圧延銅箔に対して温度300℃で60分間の再結晶焼鈍を施した後の圧延銅箔であって、
前記圧延面で見える平均結晶粒径が30μm以下であることを特徴とする圧延銅箔。 A rolled copper foil after subjecting the rolled copper foil according to any one of claims 1 to 3 to recrystallization annealing at a temperature of 300 ° C for 60 minutes,
A rolled copper foil, wherein an average crystal grain size visible on the rolled surface is 30 μm or less.

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