JP5698634B2 - Rolled copper foil - Google Patents
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- JP5698634B2 JP5698634B2 JP2011209285A JP2011209285A JP5698634B2 JP 5698634 B2 JP5698634 B2 JP 5698634B2 JP 2011209285 A JP2011209285 A JP 2011209285A JP 2011209285 A JP2011209285 A JP 2011209285A JP 5698634 B2 JP5698634 B2 JP 5698634B2
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- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims description 129
- 239000011889 copper foil Substances 0.000 title claims description 110
- 238000005097 cold rolling Methods 0.000 claims description 49
- 239000013078 crystal Substances 0.000 claims description 42
- 230000003746 surface roughness Effects 0.000 claims description 32
- 238000005096 rolling process Methods 0.000 claims description 30
- 229910052802 copper Inorganic materials 0.000 claims description 19
- 239000010949 copper Substances 0.000 claims description 19
- 238000000034 method Methods 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 12
- 238000001887 electron backscatter diffraction Methods 0.000 claims description 10
- 238000000137 annealing Methods 0.000 claims description 8
- 238000002441 X-ray diffraction Methods 0.000 claims description 6
- 238000005498 polishing Methods 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 2
- 238000005496 tempering Methods 0.000 claims description 2
- 239000003921 oil Substances 0.000 description 76
- 230000000052 comparative effect Effects 0.000 description 13
- 238000012360 testing method Methods 0.000 description 10
- 229910000881 Cu alloy Inorganic materials 0.000 description 8
- 229910045601 alloy Inorganic materials 0.000 description 8
- 239000000956 alloy Substances 0.000 description 8
- 238000005530 etching Methods 0.000 description 8
- 238000005452 bending Methods 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 6
- 238000011161 development Methods 0.000 description 5
- 239000011888 foil Substances 0.000 description 5
- 238000001953 recrystallisation Methods 0.000 description 5
- 229910052709 silver Inorganic materials 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000010408 film Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000000879 optical micrograph Methods 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 229910052718 tin Inorganic materials 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 238000005098 hot rolling Methods 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000010731 rolling oil Substances 0.000 description 2
- 238000007788 roughening Methods 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000012787 coverlay film Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000002003 electron diffraction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004439 roughness measurement Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000002966 varnish Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Landscapes
- Metal Rolling (AREA)
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
- Parts Printed On Printed Circuit Boards (AREA)
Description
本発明は、屈曲性を要求されるFPCに好適に用いられる圧延銅箔に関する。 The present invention relates to a rolled copper foil suitably used for an FPC that requires flexibility.
屈曲用FPC（フレキシブルプリント回路基板）に用いられる銅箔には高い屈曲性が求められる。銅箔に屈曲性を付与するための方法として、銅箔の（２００）面の結晶方位の配向度を高める技術（特許文献１）、銅箔の板厚方向に貫通する結晶粒の割合を多くする技術（特許文献２）、銅箔のオイルピットの深さに相当する表面粗さRy（最大高さ）を2.0μm以下に低減する技術（特許文献３）が知られている。 High flexibility is required for copper foils used for bending FPCs (flexible printed circuit boards). As a method for imparting flexibility to the copper foil, a technique for increasing the degree of orientation of the crystal orientation of the (200) plane of the copper foil (Patent Document 1), the ratio of crystal grains penetrating in the thickness direction of the copper foil is increased. (Patent Document 2), and a technology (Patent Document 3) for reducing the surface roughness Ry (maximum height) corresponding to the oil pit depth of the copper foil to 2.0 μm or less is known.
一般的なFPC製造工程は以下のようなものである。まず銅箔を樹脂フィルムと接合する。接合には、銅箔上に塗布したワニスに熱処理を加えることでイミド化する方法や、接着剤付きの樹脂フィルムと銅箔とを重ねてラミネートする方法がある。これらの工程によって接合された樹脂フィルム付き銅箔をCCL（銅張積層板）と呼ぶ。このCCL製造工程における熱処理によって、銅箔は再結晶する。
ところで、銅箔を用いてFPCを製造する際、カバーレイフィルムとの密着性を向上させるために銅箔表面をエッチングすると、表面に直径数10μm程度のくぼみ（ディッシュダウン）が発生することがあり、特に、高屈曲銅箔に発生しやすい。この原因は、高屈曲性を付与するために、再結晶焼鈍後の立方体組織が発達するように銅箔の結晶方位（２００）面が揃うよう制御することに起因する。つまり、このような制御を行っても、すべての結晶の方位が揃うことはなく、均一な組織の中に結晶方位の異なる結晶粒が局部的に存在することによるものと考えられる。その際、エッチングされる結晶面によってエッチング速度が異なるため、この結晶粒が周囲よりも局部的に深くエッチングされて、くぼみとなる。このくぼみは、回路のエッチング性を低下させたり、外観検査で不良と判定され歩留まりを低下させたりする原因となる。
The general FPC manufacturing process is as follows. First, the copper foil is bonded to the resin film. For joining, there are a method of imidizing by applying heat treatment to a varnish applied on a copper foil, and a method of laminating a resin film with an adhesive and a copper foil. The copper foil with a resin film joined by these steps is called CCL (copper-clad laminate). The copper foil is recrystallized by the heat treatment in the CCL manufacturing process.
By the way, when manufacturing FPC using copper foil, if the copper foil surface is etched to improve the adhesion to the coverlay film, a dent (dish down) with a diameter of several tens of μm may occur on the surface. In particular, it tends to occur in highly bent copper foil. This is due to controlling the crystal orientation (200) plane of the copper foil to be aligned so that a cubic structure after recrystallization annealing is developed in order to impart high flexibility. In other words, even if such control is performed, the orientations of all the crystals are not aligned, and it is considered that crystal grains having different crystal orientations exist locally in a uniform structure. At this time, since the etching rate differs depending on the crystal plane to be etched, the crystal grains are etched deeper locally than the surroundings, resulting in a depression. This dent causes the circuit etchability to deteriorate, or causes the appearance to be judged to be defective in the appearance inspection.
このようなくぼみを低減する方法として、圧延前又は圧延後に銅箔の表面に機械研磨を行って加工変質層となるひずみを与えた後、再結晶する技術（特許文献４）が報告されている。この技術によれば、加工変質層によって再結晶後に表面に不均一な結晶粒を群発させ、結晶方位の異なる結晶粒が単独で存在しないようになる。 As a method for reducing such dents, a technique (Patent Document 4) for recrystallization after mechanically polishing the surface of the copper foil before or after rolling to give a strain that becomes a work-affected layer is reported. . According to this technique, non-uniform crystal grains are clustered on the surface after recrystallization by the work-affected layer, so that crystal grains having different crystal orientations do not exist alone.
しかしながら、特許文献４記載の技術の場合、不均一な結晶粒が多く、銅箔表面の結晶が（２００）面に配向していないため、屈曲性が低下するという問題がある。
一方、特許文献３記載の高光沢の銅箔は、結晶方位が揃いやすく、また、ディッシュダウンの発生も少ない。しかしながら、高光沢の銅箔は、表面が傷つきやすい等、取り扱いが容易でなく、好まれない。
それで、本発明は上記の課題を解決するためになされたものであり、銅箔表面を適度に粗い状態により取り扱い性が良好で、屈曲性に優れるとともに、表面エッチング特性が良好な圧延銅箔の提供を目的とする。
However, in the case of the technique described in Patent Document 4, there are many non-uniform crystal grains, and crystals on the surface of the copper foil are not oriented in the (200) plane.
On the other hand, the high-gloss copper foil described in Patent Document 3 has a uniform crystal orientation and less dishdown. However, high gloss copper foil is not preferred because it is not easy to handle, such as the surface is easily damaged.
Therefore, the present invention has been made to solve the above-described problems, and the rolled copper foil has a good handleability due to a moderately rough state of the copper foil surface, excellent flexibility, and good surface etching characteristics. For the purpose of provision.
本発明者らは種々検討した結果、最終冷間圧延の最終パスの手前では銅箔の表面をあまり粗くせず、最終冷間圧延の最終パスで銅箔の表面を粗くすることで、最終的な銅箔の表面を粗くしつつも、オイルピットの形態と頻度（表面状態）がせん断帯の発生しにくいものになり、屈曲性が優れるとともに、ディッシュダウンが少なくなることを見出した。そして、せん断帯が発生しにくいオイルピットの形態と頻度（表面状態）をコンフォーカル顕微鏡像からのオイルピットの面積率によってマクロ的に評価できることを見出した。
上記の目的を達成するために、本発明の圧延銅箔は、銅箔表面で圧延平行方向に長さ175μmで測定した表面粗さRaと、前記銅箔の厚みtとの比率Ra/tが0.004以上0.007以下であり、２００℃で３０分間加熱して再結晶組織に調質した状態において、圧延面のＸ線回折で求めた（２００）面の強度（Ｉ）が、微粉末銅のＸ線回折で求めた（２００）面の強度（Ｉ0）に対し、Ｉ／Ｉ0≧50であり、銅箔表面で圧延平行方向に長さ175μmで、かつ圧延直角方向にそれぞれ50μm以上離間する３本の走査線上でそれぞれ厚み方向のプロファイルを測定したとき、オイルピットの最大深さに相当する各走査線の厚み方向の最大高さと最小高さの差の平均値dと、前記銅箔の厚みtとの比率d/tが0.1以下であり、コンフォーカル顕微鏡で測定したときのオイルピットの面積率が6％以上15％以下である。
As a result of various studies, the inventors have not made the surface of the copper foil so rough before the final pass of the final cold rolling, but roughened the surface of the copper foil in the final pass of the final cold rolling. It has been found that the shape and frequency (surface state) of the oil pits are less likely to generate a shear band, the flexibility is excellent, and the dishdown is reduced while the surface of the copper foil is roughened. The present inventors have found that the form and frequency (surface state) of oil pits in which shear bands are unlikely to occur can be evaluated macroscopically from the area ratio of oil pits from a confocal microscope image.
In order to achieve the above object, the rolled copper foil of the present invention has a ratio Ra / t between the surface roughness Ra measured at a length of 175 μm in the rolling parallel direction on the copper foil surface and the thickness t of the copper foil. The strength (I) of the (200) plane determined by X-ray diffraction of the rolled surface in a state of 0.004 to 0.007 and heated to 200 ° C. for 30 minutes to be recrystallized is X With respect to the intensity (I 0 ) of the (200) plane determined by line diffraction, I / I 0 ≧ 50, the length of the copper foil surface is 175 μm in the rolling parallel direction, and is separated by 50 μm or more in the direction perpendicular to the rolling in three scan lines as measured in the thickness direction of the profile, respectively, and the average value d of the difference between the maximum height and minimum height in the thickness direction of each scanning line corresponding to the maximum depth of the oil pits, of the copper foil Oil pit area when the ratio d / t to thickness t is 0.1 or less and measured with a confocal microscope There is 15% or less than 6%.
上記した200℃×30分熱処理後の銅箔表面を電解研磨後にEBSDで観察した場合に、[100]方位からの角度差が15度以上の結晶粒の面積率が20％以下であることが好ましい。
鋳塊を熱間圧延後、冷間圧延と焼鈍とを繰り返し、最後に最終冷間圧延を行って製造され、当該最終冷間圧延工程において、最終パス前の段階で、Ra/tが0.002以上0.004以下であることが好ましい。
When the copper foil surface after the above heat treatment at 200 ° C. for 30 minutes is observed by EBSD after electrolytic polishing, the area ratio of crystal grains having an angle difference of 15 degrees or more from the [100] orientation is 20% or less. preferable.
After the ingot is hot-rolled, cold rolling and annealing are repeated, and finally the final cold-rolling is performed. In the final cold-rolling process, Ra / t is 0.002 or more before the final pass. It is preferably 0.004 or less.
本発明によれば、銅箔表面を適度に粗くして取り扱い性を向上し、屈曲性に優れるとともに、表面エッチング特性が良好な圧延銅箔が得られる。 According to the present invention, it is possible to obtain a rolled copper foil having an appropriately roughened copper foil surface to improve handleability, excellent flexibility, and good surface etching characteristics.
以下、本発明の実施形態に係る圧延銅箔について説明する。なお、本発明において％とは、特に断らない限り、質量％を示すものとする。 Hereinafter, the rolled copper foil which concerns on embodiment of this invention is demonstrated. In the present invention, “%” means “% by mass” unless otherwise specified.
まず、図１を参照して、本発明の技術思想について説明する。最終冷間圧延でのロール粗度を大きくして銅箔表面を粗くすると、銅箔の取り扱い性は向上するが、ディッシュダウンが生じ易くなる（図１の従来例１）。これは、以下のように考えられる。
最終冷間圧延での粗いロールにより、銅箔の表面にオイルピットが形成されるが、加工が進むにつれ、オイルピットの先端部にせん断変形帯が生じやすい。さらに加工が続くとせん断変形帯が深く発達する。このようにして、深いせん断変形帯の発生したオイルピットの部分は、再結晶の際に、他の均一な組織の中で結晶方位の異なる結晶粒となり、エッチングの際のディッシュダウンの起点となると考えられる。
一方、銅箔の屈曲性を得るために光沢度（表面粗さ）を高める手法が従来から知られている。これは、粗度の低いロールで最終冷間圧延することで、オイルピットの形成を抑えることで、せん断変形帯が生じ難くなるためと考えられる。しかし、銅箔の光沢度を高くする（表面粗さを小さくする）と、銅箔の取り扱い性が低下する（図１の従来例２）ため、銅箔を利用する側には好まれない。
First, the technical idea of the present invention will be described with reference to FIG. When the roll roughness in the final cold rolling is increased to roughen the copper foil surface, the handleability of the copper foil is improved, but dishdown is likely to occur (conventional example 1 in FIG. 1). This is considered as follows.
An oil pit is formed on the surface of the copper foil by the rough roll in the final cold rolling, but as the processing proceeds, a shear deformation band tends to occur at the tip of the oil pit. If the processing continues further, the shear deformation zone develops deeply. In this way, the portion of the oil pit in which a deep shear deformation zone has occurred becomes crystal grains having different crystal orientations in other uniform structures during recrystallization, and serves as a starting point for dishdown during etching. Conceivable.
On the other hand, a technique for increasing the glossiness (surface roughness) is conventionally known in order to obtain the flexibility of the copper foil. This is considered to be because it is difficult to produce a shear deformation band by suppressing the formation of oil pits by final cold rolling with a roll having low roughness. However, if the glossiness of the copper foil is increased (the surface roughness is reduced), the handleability of the copper foil is lowered (conventional example 2 in FIG. 1), and therefore it is not preferred for the side using the copper foil.
これに対し、本発明者は、最終冷間圧延の最終パスの手前では銅箔の表面をあまり粗くせず（例えば、粗度の低いロールで圧延し）、最終冷間圧延の最終パスで銅箔の表面を粗くする（例えば、粗いロールで圧延する）ことで、オイルピットが形成されて最終的な銅箔の表面は粗い状態になるものの、せん断変形帯があまり発達しないオイルピットの形状と頻度となり、結果として均一な組織中で結晶方位の異なる結晶粒が減少し、ディッシュダウンが少なくなることを見出した（図１の本発明例）。
つまり、従来、銅箔の配向性は単に銅箔表面の粗さに依存すると考えられてきたが、実際には、材料内部のせん断変形帯の規模（発達度）が配向度（及びディッシュダウン）に影響することが分かった。そして、最終冷間圧延において、最終パス以前のパスでせん断帯の発達を充分に抑制できれば、最終パスで銅箔表面を粗く仕上げても、高い配向性を得ることが出来る。
On the other hand, the present inventor does not make the surface of the copper foil very rough (for example, roll with a roll having a low roughness) before the final pass of the final cold rolling. By roughening the surface of the foil (for example, rolling with a rough roll), oil pits are formed and the surface of the final copper foil becomes rough, but the shape of the oil pits where the shear deformation band does not develop so much As a result, it was found that crystal grains having different crystal orientations were reduced in a uniform structure, and dishdown was reduced (example of the present invention in FIG. 1).
In other words, conventionally, the orientation of copper foil has been thought to depend solely on the roughness of the copper foil surface, but in reality, the scale (development) of the shear deformation band inside the material is the orientation (and dishdown). It was found that it affects. In the final cold rolling, if the development of the shear band can be sufficiently suppressed in the pass before the final pass, high orientation can be obtained even if the copper foil surface is finished rough in the final pass.
又、本発明は、上記したせん断帯の発達度を、コンフォーカル顕微鏡像からのオイルピットの面積率によってマクロ的に評価し、ディッシュダウンが低減する面積率の範囲を見出したことを特徴としている。
これに対し、従来から用いられている表面粗さの値だけではオイルピットの情報を明確に捉えることができない。つまり、圧延銅箔表面を観察すると、圧延直角方向ＴＤに沿ってオイルピットの発生が観察されるが、図２に示すように、オイルピットの断面形状には、ＴＤ方向の長さが短い三角形のもの（図２の符号Ｐ１）の他、台形状のもの（図２の符号Ｐ２）も存在することがわかった。また、オイルピットの深さは同じでも、ＲＤ方向には、ピットの開き度合いが広いものと狭いものがある。これらのオイルピットの形状の違いは、銅箔の表面のうねりの測定を行う一般的なRa、Ry、Rz、Smといった表面粗さの測定では、十分に反映することができないと考えられる。
そこで、コンフォーカル（共焦点）顕微鏡を用い、オイルピットに相当する画像領域の割合（面積率）を求めることにより、オイルピットの形状を反映し、ディッシュダウンや屈曲性の良否に対応した差異を得ることができる。なお、オイルピットの面積率は、コンフォーカル顕微鏡で撮像したZ軸(高さ方向)の高度差を所定の閾値の前後で2値化し、この閾値より深い部分をオイルピット部分として抽出し、その面積割合を求めたものである。
In addition, the present invention is characterized by macroscopically evaluating the degree of development of the above-described shear band from the area ratio of oil pits from a confocal microscope image, and finding a range of the area ratio in which dishdown is reduced. .
On the other hand, oil pit information cannot be clearly grasped only by the conventionally used surface roughness value. That is, when the surface of the rolled copper foil is observed, the occurrence of oil pits is observed along the direction TD perpendicular to the rolling. As shown in FIG. 2, the oil pit has a cross-sectional shape with a short TD length. It was found that there was a trapezoidal shape (reference numeral P2 in FIG. 2) in addition to the above-mentioned one (reference numeral P1 in FIG. 2). Moreover, even if the depth of the oil pit is the same, there are a wide pit opening degree and a narrow pit direction in the RD direction. It is considered that these differences in the shape of the oil pits cannot be sufficiently reflected in general surface roughness measurements such as Ra, Ry, Rz, and Sm that measure the surface undulation of the copper foil.
Therefore, by using a confocal microscope, the ratio (area ratio) of the image area corresponding to the oil pit is obtained to reflect the shape of the oil pit, and the difference corresponding to the quality of the dishdown or flexibility. Can be obtained. The oil pit area ratio is binarized before and after a predetermined threshold value for the altitude difference of the Z axis (height direction) imaged with a confocal microscope, and the part deeper than this threshold value is extracted as the oil pit part. The area ratio is obtained.
次に、本発明の圧延銅箔の規定及び組成について説明する。
（１）オイルピットの面積率
上記したように、最終冷間圧延の最終パスの手前では銅箔の表面をあまり粗くせず、最終冷間圧延の最終パスで銅箔の表面を粗くすることで、最終的な銅箔の表面を粗くしつつ、せん断変形帯の発達しにくいオイルピットの形状が得られ、ディッシュダウンが少なくなる。そして、このようなせん断変形帯の発達しにくいオイルピットを有する表面は、コンフォーカル顕微鏡で測定したときのオイルピットの面積率が6％以上15％以下となることが本発明者らの実験（後述する実施例）によって明らかとなった。
Next, the rule and composition of the rolled copper foil of the present invention will be described.
(1) Area ratio of oil pit As described above, the surface of the copper foil is not roughened before the final pass of the final cold rolling, but is roughened in the final pass of the final cold rolling. The final surface of the copper foil is roughened, and an oil pit shape in which a shear deformation zone is difficult to develop is obtained, and dishdown is reduced. The surface of the oil pit that is difficult to develop such a shear deformation zone has an oil pit area ratio of 6% to 15% when measured with a confocal microscope. It became clear by the Example) mentioned later.
オイルピットの面積率が15％を超えると、せん断変形帯の発達したオイルピットが増加する。材料内部でせん断変形帯が発達すると、再結晶の際、他の均一な組織の中で結晶方位の異なる結晶粒となり、エッチング時のディッシュダウンが生じやすくなる。 When the oil pit area ratio exceeds 15%, the number of oil pits with developed shear deformation zones increases. When a shear deformation band develops inside the material, during recrystallization, crystal grains having different crystal orientations are formed in another uniform structure, and dishdown is likely to occur during etching.
一方、オイルピットの面積率が6％未満となる場合として、2つの条件がある。条件の１つは、最終冷間圧延のすべてのパスを粗度の低いロールを用いる。この条件では、深いオイルピットが少なく、せん断変形帯も発達し難いため、ディッシュダウンが低減するが、銅箔の表面粗さが小さくなり過ぎ（後述するＲａ／ｔの要件を満たさず）、銅箔製品の取り扱いに難があるため、好ましくない。
２つ目の条件は、最終冷間圧延の最終パスの手前では銅箔の表面を粗くし、最終冷間圧延の最終パスで粗度の低いロールを用いて銅箔の表面を平滑にする。この条件では、最終パスで粗度の低いロールを用いることで、最終パスの手前で形成されたオイルピットのうち銅箔表面に近い部分が最終パスで広げられて平らに近づき、表面粗さが小さくなる。しかし、オイルピット内部の狭い谷部分はそのまま残る。従って、オイルピットの表面部分の開口は狭くなってオイルピットの面積率自体は小さくなるが、最終パスの手前では粗いロールを用いているため、オイルピットにはせん断変形帯が発達してしまい、最終パス後もせん断変形帯が残って、ディッシュダウンが多数発生する。そして、このようにオイルピットの面積率が小さいもののディッシュダウンが多数発生する状態は、オイルピットの面積率が6％未満の場合に顕著となる。
On the other hand, there are two conditions when the area ratio of the oil pit is less than 6%. One condition is to use a roll with low roughness for all passes of the final cold rolling. Under these conditions, since there are few deep oil pits and the shear deformation zone is difficult to develop, the dishdown is reduced, but the surface roughness of the copper foil becomes too small (not satisfying the Ra / t requirement described later), and the copper Since it is difficult to handle the foil product, it is not preferable.
The second condition is that the surface of the copper foil is roughened before the final pass of the final cold rolling, and the surface of the copper foil is smoothed using a roll having low roughness in the final pass of the final cold rolling. Under this condition, by using a roll with low roughness in the final pass, the portion of the oil pit formed in front of the final pass that is close to the copper foil surface is widened in the final pass and approaches flat, and the surface roughness is reduced. Get smaller. However, the narrow valley inside the oil pit remains intact. Therefore, the opening of the surface part of the oil pit is narrowed and the area ratio of the oil pit itself is reduced, but since a rough roll is used before the final pass, a shear deformation zone develops in the oil pit, Even after the final pass, a shear deformation band remains and many dishdowns occur. A state in which a large number of dishdowns occur although the area ratio of the oil pit is small as described above becomes remarkable when the area ratio of the oil pit is less than 6%.
なお、オイルピットの面積率を6％以上とする方法としては、上記したように最終冷間圧延において、最終パス以前のパスでの浅くて、せん断帯が発達していないようなオイルピットには、オイルピットが形成されるよう、最終冷間圧延の最終パス以前のパスでは粗さ（表面粗さＲａが例えば0.05μm以下）が比較的小さいロールを用いて圧延し、かつ、最終冷間圧延の最終パスでは、粗さ（表面粗さＲａが例えば0.06μm以上）が比較的大きいロールを用いて圧延し、最終的に得られる銅箔表面を粗くすればよい。最終パス以前のパスでは形成されるオイルピットが浅く、せん断帯が発達していないので、最終冷間圧延の最終パスで銅箔の表面を粗くしてもせん断帯の発達したオイルピットは増えず、ディッシュダウンは少なくなる。一方、最終冷間圧延の最終パス以前のパスで粗さ（表面粗さＲａが例えば0.05μmを超える）が大きいロールを用いて圧延すると、せん断帯の発達しやすいオイルピットが形成され、最終パスにてオイルピットが発達し、その面積が増加し、オイルピットの面積率が15％を超え、せん断帯の発達が顕著となり、ディッシュダウンが生じやすくなる。 In addition, as a method of setting the area ratio of the oil pit to 6% or more, as described above, in the final cold rolling, in the oil pit that is shallow in the pass before the final pass and the shear band is not developed. In order to form an oil pit, the roll before the final pass of the final cold rolling is rolled using a roll having a relatively small roughness (surface roughness Ra is, for example, 0.05 μm or less), and the final cold rolling is performed. In the final pass, rolling may be performed using a roll having a relatively large roughness (surface roughness Ra of, for example, 0.06 μm or more), and the finally obtained copper foil surface may be roughened. Since the oil pits formed in the pass before the final pass are shallow and the shear band is not developed, even if the surface of the copper foil is roughened in the final pass of the final cold rolling, the oil pits with the developed shear band do not increase. Dish down is less. On the other hand, when rolling is performed using a roll having a large roughness (surface roughness Ra exceeds 0.05 μm, for example) in the pass before the final cold rolling pass, an oil pit in which a shear band easily develops is formed. The oil pit develops at, the area increases, the area ratio of the oil pit exceeds 15%, the development of the shear band becomes remarkable, and dishdown is likely to occur.
ここで、最終冷間圧延工程において、最終パスより前のパスで粗さ（表面粗さＲａが例えば0.05μm以下）が比較的小さいロールを用いることで、最終冷間圧延の銅箔表面が比較的平滑となる。具体的には、最終冷間圧延工程の最終パスの１パス前の段階で、表面粗さRaと箔厚みｔとの比率(Ra/t)が0.0020以上0.0040以下であるとよい。Ra/tがこの範囲であるような表面状態のもとで最終パスの圧延を行えば、最終パスで銅箔の表面を粗くしても、形成されたオイルピットにせん断帯が導入され難くなるので好ましい。
なお、後述のように、最終冷間圧延工程の最終パス終了後の(Ra/t)を0.004以上0.007以下とする。
Here, in the final cold rolling process, the surface of the copper foil of the final cold rolling is compared by using a roll having a relatively small roughness (surface roughness Ra is, for example, 0.05 μm or less) in the pass before the final pass. Smooth. Specifically, the ratio (Ra / t) between the surface roughness Ra and the foil thickness t is preferably 0.0020 or more and 0.0040 or less at a stage one pass before the final pass of the final cold rolling process. If rolling of the final pass is performed under such a surface condition that Ra / t is in this range, even if the surface of the copper foil is roughened by the final pass, it is difficult to introduce a shear band into the formed oil pit. Therefore, it is preferable.
As will be described later, (Ra / t) after the final pass of the final cold rolling step is set to 0.004 or more and 0.007 or less.
（２）Ｉ／Ｉ0
本発明の銅箔に、高屈曲性を付与するため、２００℃で３０分間加熱して再結晶組織に調質した状態において、圧延面のＸ線回折で求めた（２００）面の強度（Ｉ）を、微粉末銅のＸ線回折で求めた（２００）面の強度（Ｉ0）に対し、Ｉ／Ｉ0≧50に規定する。これにより、屈曲性に優れた（２００）面の配向度が高まる。Ｉ／Ｉ0＜50になると、屈曲性が低下する。上記２００℃で３０分の焼鈍は、CCL製造工程において銅箔に付与される温度履歴を模したものである。
なお、Ｉ／Ｉ0≧50となるためには、最終冷間圧延の加工度が98％以上であることが望ましい。
(2) I / I 0
In order to impart high flexibility to the copper foil of the present invention, the strength of the (200) plane (I) determined by X-ray diffraction of the rolled surface in a state of heating to 200 ° C. for 30 minutes and tempering the recrystallized structure. ) Is defined as I / I 0 ≧ 50 with respect to the intensity (I 0 ) of the (200) plane obtained by X-ray diffraction of fine powder copper. Thereby, the degree of orientation of the (200) plane excellent in flexibility is increased. When I / I 0 <50, the flexibility decreases. The annealing at 200 ° C. for 30 minutes imitates the temperature history given to the copper foil in the CCL manufacturing process.
In order to satisfy I / I 0 ≧ 50, it is desirable that the degree of work of the final cold rolling is 98% or more.
（３）Ra/t
表面粗さを従来のものとは変えずに、ディッシュダウンを少なくするため、最終冷間圧延後のRa（ｍｍ）/t（ｍｍ）を0.004以上0.007以下に規定する。このようにすると、表面粗さを従来の銅箔と同等としつつ、ディッシュダウンを低減することができる。なお、表面粗さを厚みで割ることで、銅箔の厚みによらず銅箔表面の粗さの評価が行える。例えば、銅箔の厚みtが薄くなると、同じ表面粗さであっても銅箔厚みに占める表面凹凸の割合が大きくなり、上記したオイルピットの面積率による銅箔表面の評価が十分に行えないことがある。
ここで、Ra（中心線平均粗さ）はＪＩＳ Ｂ０６０１に規定され、本発明においては銅箔表面で圧延平行方向に長さ175μmで、かつ圧延直角方向にそれぞれ50μm以上離間する３本の走査線上で測定した値の平均値とする。
(3) Ra / t
In order to reduce dishdown without changing the surface roughness from the conventional one, Ra (mm) / t (mm) after final cold rolling is specified to be 0.004 or more and 0.007 or less. If it does in this way, dishdown can be reduced, making surface roughness equivalent to the conventional copper foil. In addition, by dividing the surface roughness by the thickness, the roughness of the copper foil surface can be evaluated regardless of the thickness of the copper foil. For example, if the thickness t of the copper foil is reduced, the ratio of surface irregularities in the copper foil thickness increases even if the surface roughness is the same, and the copper foil surface cannot be sufficiently evaluated by the oil pit area ratio described above. Sometimes.
Here, Ra (center line average roughness) is defined in JIS B0601, and in the present invention, on the surface of the copper foil, the length is 175 μm in the rolling parallel direction, and the three scanning lines are separated by 50 μm or more in the direction perpendicular to the rolling direction. The average value of the values measured in.
（４）d/t
銅箔表面の粗さがそれほど大きくなく、オイルピットの多くはせん断変形帯があまり発達していないと考えられる場合でも、深いオイルピットが幾つか存在する場合がある。深いオイルピットではせん断変形帯が発達している可能性が高く、その場合には、ディッシュダウンの発生の起点となる。そこで、本発明では、オイルピットの最大深さの平均値dをd/t≦0.1に規定する。
オイルピットの最大深さの平均値dを厚みtで割ることで、銅箔の厚みによらず銅箔表面の評価が行える。すなわち、オイルピットの最大深さが同一であっても銅箔の厚みtが薄くなると、その影響が大きくなるためである。
ここでオイルピットの最大深さの平均値dは、図３に示すように銅箔表面で圧延平行方向ＲＤに長さ175μmで、かつ圧延直角方向ＴＤにそれぞれ50μm以上離間する３本の走査線Ｌ１〜Ｌ３上で、オイルピットの最大深さに相当する各走査線Ｌ１〜Ｌ３の厚み方向の最大高さＨＭと最小高さＨＳの差diの平均値である。具体的には、接触式粗さで、Ｌ１〜Ｌ３上の厚み方向のプロファイルを測定して最大高さＨＭと最小高さＨＳを求め、各走査線Ｌ１〜Ｌ３のdiを平均すればよい。
銅箔（又は銅合金箔）の厚みは特に制限されないが、例えば５〜５０μｍのものを好適に用いることができる。
(4) d / t
Even when the roughness of the copper foil surface is not so great and many of the oil pits are considered to have less developed shear deformation bands, there may be some deep oil pits. In a deep oil pit, there is a high possibility that a shear deformation zone has developed, and in this case, dishdown starts. Therefore, in the present invention, the average value d of the maximum depth of the oil pit is defined as d / t ≦ 0.1.
By dividing the average value d of the maximum depth of the oil pit by the thickness t, the copper foil surface can be evaluated regardless of the thickness of the copper foil. That is, even if the maximum depth of the oil pit is the same, the influence becomes greater as the thickness t of the copper foil is reduced.
Here, the average value d of the maximum depth of the oil pit is three scanning lines having a length of 175 μm in the rolling parallel direction RD and 50 μm or more in the rolling perpendicular direction TD on the copper foil surface as shown in FIG. on L 1 ~L 3, the average value of the differences di maximum height H M and a minimum height H S in the thickness direction of each scanning line L 1 ~L 3 corresponding to the maximum depth of the oil pits. Specifically, a contact-type roughness, maximum calculated height H M and a minimum height H S by measuring the thickness direction of the profile on the L 1 ~L 3, di of each scanning line L 1 ~L 3 Should be averaged.
Although the thickness in particular of copper foil (or copper alloy foil) is not restrict | limited, For example, the thing of 5-50 micrometers can be used conveniently.
（５）EBSDによる方位差
上記したように、ディッシュダウンは、銅箔を樹脂フィルムと接合する際の熱処理により、再結晶した均一な組織の中で結晶方位の異なる結晶粒が単独で存在する割合が多い場合、エッチングの際にこの単独結晶粒が周囲よりも深くエッチングされてできるくぼみである。そこで、上記熱処理として、CCL製造工程において銅箔に付与される温度履歴を模した熱処理条件（２００℃で３０分間）で銅箔を加熱して再結晶組織に調質する。そして、この状態の結晶方位として、銅箔表面を電解研磨後にEBSDで観察した場合に、[100]方位からの角度差が15度以上の結晶粒の面積率が２０％以下であることが好ましい。なお、すでに熱履歴を受けているCCLとなった銅箔についても、２００℃で３０分間加熱してよい。一度再結晶するまで熱処理されたものは、それ以上加熱してもほぼ変化しないため、EBSDで観察の観察においては、熱履歴を受けた銅箔、受けない銅箔を区別せず、２００℃で３０分間加熱することとする。
EBSDで観察した場合に上記面積率が20％未満であれば、銅箔表面の結晶粒同士の方位差が小さく、均一な組織の中に結晶方位の異なる結晶粒が単独で存在する割合が少なくなるので、エッチングによるくぼみ（ディッシュダウン）が低減する。なお、EBSDで観察した場合に上記面積率を20％未満とするには、上記したように最終冷間圧延において、最終パス以前のパスでせん断帯の発達を抑制する、つまり最終冷間圧延の最終パス以前のパスで粗さ（表面粗さＲａが例えば0.05μm以下）が比較的小さいロールを用いて圧延すればよい。
(5) Orientation difference due to EBSD As described above, dishdown is the ratio of crystal grains having different crystal orientations in a uniform structure recrystallized by heat treatment when copper foil is bonded to a resin film. In many cases, the single crystal grains are etched deeper than the surroundings during etching. Therefore, as the heat treatment, the copper foil is heated under the heat treatment conditions (200 ° C. for 30 minutes) simulating the temperature history applied to the copper foil in the CCL manufacturing process, and the recrystallized structure is tempered. As the crystal orientation in this state, when the copper foil surface is observed by EBSD after electrolytic polishing, the area ratio of crystal grains having an angle difference of 15 degrees or more from the [100] orientation is preferably 20% or less. . In addition, you may heat for 30 minutes at 200 degreeC also about the copper foil used as CCL which has already received thermal history. The one that has been heat-treated until it is recrystallized does not change even if it is heated further. Therefore, in observation observed with EBSD, it is not distinguished between copper foil that has undergone thermal history and copper foil that has not received heat, at 200 ° C. Heat for 30 minutes.
If the area ratio is less than 20% when observed by EBSD, the orientation difference between the crystal grains on the copper foil surface is small, and the proportion of crystal grains having different crystal orientations in a uniform structure is small. Therefore, the dent (dish down) due to etching is reduced. In order to reduce the area ratio to less than 20% when observed with EBSD, as described above, in the final cold rolling, the development of the shear band is suppressed in the pass before the final pass. What is necessary is just to roll using a roll with comparatively small roughness (surface roughness Ra is 0.05 micrometer or less) by the pass before the last pass.
（６）組成
銅箔としては、純度９９．９ｗｔ％以上のタフピッチ銅、無酸素銅を用いることができ、又、要求される強度や導電性に応じて公知の銅合金を用いることができる。
無酸素銅はＪＩＳ-Ｈ３５１０（合金番号Ｃ１０１１）、ＪＩＳ-Ｈ３１００（合金番号Ｃ１０２０）に規格され、タフピッチ銅はＪＩＳ-Ｈ３１００（合金番号Ｃ１１００）に規格されている。
公知の銅合金としては、例えば、０．０１〜０．３ｗｔ％の錫入り銅合金（より好ましくは０．００１〜０．０２ｗｔ％の錫入り銅合金）；０．０１〜０．０５ｗｔ％の銀入り銅合金；０．００５〜０．０２ｗｔ％のインジウム入り銅合金；０．００５〜０，０２ｗｔ％のクロム入り銅合金；錫、銀、インジウム、及びクロムの群から選ばれる一種以上を合計で０．０５ｗｔ％以下含む銅合金等が挙げられ、中でも、導電性に優れたものとしてCu-0.02ｗｔ％Agがよく用いられる。
(6) Composition As the copper foil, tough pitch copper or oxygen-free copper having a purity of 99.9 wt% or more can be used, and a known copper alloy can be used depending on required strength and conductivity.
Oxygen-free copper is standardized by JIS-H3510 (alloy number C1011) and JIS-H3100 (alloy number C1020), and tough pitch copper is standardized by JIS-H3100 (alloy number C1100).
Known copper alloys include, for example, 0.01 to 0.3 wt% tin-containing copper alloy (more preferably 0.001 to 0.02 wt% tin-containing copper alloy); 0.01 to 0.05 wt% Silver-containing copper alloy; 0.005-0.02 wt% indium-containing copper alloy; 0.005-0.02 wt% chromium-containing copper alloy; one or more selected from the group consisting of tin, silver, indium, and chromium In particular, Cu-0.02 wt% Ag is often used as a material having excellent conductivity.
次に、本発明の圧延銅箔の製造方法の一例について説明する。まず、銅及び必要な合金元素、さらに不可避不純物からなる鋳塊を熱間圧延後、冷間圧延と焼鈍とを繰り返し、最後に最終冷間圧延で所定厚みに仕上げる。
ここで、上記したように、最終冷間圧延の最終パスの手前では銅箔の表面をあまり粗くせず、最終冷間圧延の最終パスで銅箔の表面を粗くすることで、最終的な銅箔の表面を粗いが、せん断変形帯に発達しにくいオイルピットを有する表面状態となり、ディッシュダウンが少なくなる。そして、このようなせん断変形帯が少ない表面は、オイルピットの面積率が6以上15％以下となる。
Next, an example of the manufacturing method of the rolled copper foil of this invention is demonstrated. First, an ingot made of copper, necessary alloy elements, and inevitable impurities is hot-rolled, and then cold-rolling and annealing are repeated, and finally, it is finished to a predetermined thickness by final cold-rolling.
Here, as described above, the surface of the copper foil is not roughened before the final pass of the final cold rolling, and the final copper is roughened by roughening the surface of the copper foil in the final pass of the final cold rolling. Although the surface of the foil is rough, it becomes a surface state having oil pits which are difficult to develop in the shear deformation band, and dishdown is reduced. And the surface ratio with such a small shear deformation band has an oil pit area ratio of 6 to 15%.
従って、最終冷間圧延の最終パスの手前では、銅箔の表面をあまり粗くしないよう、粗さ（表面粗さＲａが例えば0.05μm以下）が比較的小さいロールを用いて圧延したり、最終冷間圧延における1パス加工度を大きくして圧延すればよい。一方、最終冷間圧延の最終パスでは、粗さ（表面粗さＲａが例えば0.06μm以上）が比較的大きいロールを用いて圧延したり、粘度の高い圧延油を用いて圧延し、最終的に得られる銅箔表面を粗くする。
なお、最終的な銅箔の表面を粗いが、せん断変形帯に発達しにくいオイルピットを有する表面状態を作り込むためには、最終冷間圧延の最終2パス、又は最終パスで、上記したように粗いロールを用いたり粘度の高い圧延油を用いて圧延することが必要であるが、調整し易いことから最終パスでの圧延条件を調整することが好ましい。一方、最終冷間圧延の最終3パス以前からロールの粗さを粗くすると、形成されたオイルピットに更に最終パスの加工によってせん断変形帯が発達する。
Therefore, before the final pass of the final cold rolling, the surface of the copper foil is rolled using a roll having a relatively small roughness (surface roughness Ra is, for example, 0.05 μm or less) or the final cold rolling is performed. What is necessary is just to roll by increasing the degree of 1-pass processing in hot rolling. On the other hand, in the final pass of the final cold rolling, rolling is performed using a roll having a relatively large roughness (surface roughness Ra is, for example, 0.06 μm or more), or rolling is performed using a highly viscous rolling oil. The obtained copper foil surface is roughened.
In addition, in order to create a surface state having oil pits that are rough on the surface of the final copper foil but are difficult to develop in the shear deformation zone, as described above, in the final two passes or the final pass of the final cold rolling. It is necessary to use a coarse roll or a high-viscosity rolling oil, but it is preferable to adjust the rolling conditions in the final pass because it is easy to adjust. On the other hand, when the roughness of the roll is increased before the final three passes of the final cold rolling, a shear deformation band develops further in the formed oil pit by the processing of the final pass.
なお、最終冷間圧延の直前の焼鈍で得られる再結晶粒の平均粒径が５〜２０μｍになるよう、焼鈍条件下を調整するとよい。又、最終冷間圧延での圧延加工度を９８％以上とするとよい。 In addition, it is good to adjust annealing conditions so that the average particle diameter of the recrystallized grain obtained by annealing immediately before final cold rolling may be 5-20 micrometers. Also, the degree of rolling in the final cold rolling is preferably 98% or more.
表１に示す組成の元素を添加したタフピッチ銅又は無酸素銅を原料としてインゴットを鋳造し、800℃以上で厚さ10ｍｍまで熱間圧延を行い、表面の酸化スケールを面削した後、冷間圧延と焼鈍とを繰り返し、最後に最終冷間圧延で表１に記載の厚みに仕上げた。最終冷間圧延での圧延加工度を99.2％とした。
なお、表１の組成の欄の「0.02%Ag添加TPC」は、ＪＩＳ-Ｈ３１００（合金番号Ｃ１１００）のタフピッチ銅（TPC）に０．０２質量％のAgを添加したこと意味する。また、表１の組成の欄の「0.01%Ag0.005%Sn添加OFC」はＪＩＳ-Ｈ３１００（合金番号Ｃ１０２０）の無酸素銅（OFC）に０．０１質量％のAg及び０．００５質量％のSnを添加したことを意味する。但し、実施例６のみ無酸素銅としてＪＩＳ-Ｈ３５１０（合金番号Ｃ１０１１）に規格されている無酸素銅（ＯＦＣ）を用い、実施例４、５、８、９は無酸素銅としてＪＩＳ-Ｈ３１００（合金番号Ｃ１０２０）に規格されている無酸素銅（ＯＦＣ）を用いた。
なお、最終冷間圧延は10〜15パスで行い、表１に示すように、最終パスの手前までのロールの表面粗さ、及び最終パスのロールの表面粗さを変えて圧延を行った。最終パスの1パス目から最終パスの手前までのロールの表面粗さはすべて同じである。なお、最終圧延の加工度は、比較例5以外は99％とし、比較例5は96％とした。
After casting ingots using tough pitch copper or oxygen-free copper with the elements shown in Table 1 as raw materials, hot rolling to a thickness of 10 mm at 800 ° C or higher, and chamfering the oxide scale on the surface, Rolling and annealing were repeated, and finally, the final cold rolling was performed to the thickness shown in Table 1. The rolling degree in final cold rolling was 99.2%.
“0.02% Ag-added TPC” in the column of composition in Table 1 means that 0.02 mass% of Ag was added to tough pitch copper (TPC) of JIS-H3100 (Alloy No. C1100). “0.01% Ag 0.005% Sn-added OFC” in the column of composition in Table 1 is 0.01% Ag and 0.005% by mass in oxygen-free copper (OFC) of JIS-H3100 (Alloy No. C1020). Means that Sn was added. However, oxygen free copper (OFC) standardized in JIS-H3510 (alloy number C1011) is used as oxygen free copper only in Example 6, and Examples 4, 5, 8, and 9 are JIS-H3100 (oxygen free copper) as oxygen free copper. Oxygen-free copper (OFC) specified in Alloy No. C1020) was used.
The final cold rolling was performed in 10 to 15 passes, and as shown in Table 1, rolling was performed while changing the surface roughness of the roll before the final pass and the surface roughness of the roll in the final pass. The surface roughness of the roll from the first pass of the final pass to the front of the final pass is the same. In addition, the workability of the final rolling was 99% except for Comparative Example 5, and was 96% for Comparative Example 5.
このようにして得られた各銅箔試料について、諸特性の評価を行った。
（１）表面粗さＲａ：Ra（中心線平均粗さ）はＪＩＳ Ｂ０６０１に準じて測定し、試料表面をコンフォーカル顕微鏡（レーザーテック社製、型番：HD100D）を用いて、圧延平行方向に長さ175μmで測定した値とした。
（２）立方体集合組織
試料を２００℃で３０分間加熱した後、圧延面のＸ線回折で求めた（２００）面強度の積分値（Ｉ）を求めた。この値をあらかじめ測定しておいた微粉末銅（３２５ｍｅｓｈ，水素気流中で３００℃で１時間加熱してから使用）の（２００）面強度の積分値（Ｉ0 ）で割り、Ｉ／Ｉ0 値を計算した。
Various characteristics of each copper foil sample thus obtained were evaluated.
(1) Surface roughness Ra: Ra (center line average roughness) is measured in accordance with JIS B0601, and the sample surface is length in the rolling parallel direction using a confocal microscope (manufactured by Lasertec, model number: HD100D). The value measured at 175 μm was used.
(2) Cube texture After heating the sample at 200 ° C. for 30 minutes, the integral value (I) of (200) plane strength obtained by X-ray diffraction of the rolled surface was obtained. Divide this value by the integral value (I0) of the (200) plane strength of finely divided copper (325 mesh, heated for 1 hour at 300 ° C. in a hydrogen stream) and calculate the I / I0 value. Calculated.
（３）オイルピットの最大深さ（平均値d）
コンフォーカル顕微鏡（レーザーテック社製、型番：HD100D）を用い、図３に示すようにして、銅箔表面で圧延平行方向ＲＤに長さ175μmで、かつ圧延直角方向ＴＤにそれぞれ50μm以上離間する３本の走査線Ｌ１〜Ｌ３上の最大高さＨＭと最小高さＨＳの差diをそれぞれ求めた。各走査線Ｌ１〜Ｌ３のdiを平均してdとした。なお、d(mm)/t(mm)とした。
（４）EBSDによる方位差
（２）で２００℃で３０分間加熱した後の試料表面を電解研磨後にEBSD（後方散乱電子線回析装置、日本電子株式会社JXA8500F、加速電圧20kV、電流2e-8A、測定範囲1000μm×1000μm、ステップ幅5μm）で観察した。[100]方位からの角度差が15度以上の結晶粒の面積率を画像解析で求めた。さらに、試料表面1mm四方の観察範囲内で結晶粒径が20μmを超えるものの個数を目視で数えた。そして、この観察範囲を含む試料について、アデカテックCL-8（株式会社アデカ製）20%溶液を用いて常温で2分間エッチングを行い、エッチング後の表面を光学顕微鏡で撮影した画像を明暗二値化し、短径50μmを越える暗部をディッシュダウンとして数えた。なお、エッチング後の銅箔表面は結晶方位を反映した形状となり、[100]方位を持った組織は銅箔表面に平行な面となるのに対し、その他の結晶方位を持った部分は結晶方位に起因する凹凸ができる。従って、ディッシュダウンの部分は光学顕微鏡で暗く見えることになる。
なお、図４は実施例１の表面の光学顕微鏡像を示し、図５は比較例３の表面光学顕微鏡像を示す。
(3) Maximum oil pit depth (average value d)
Using a confocal microscope (made by Lasertec, model number: HD100D), as shown in FIG. 3, three pieces having a length of 175 μm in the rolling parallel direction RD on the copper foil surface and 50 μm or more apart in the rolling perpendicular direction TD, respectively. The difference di between the maximum height H M and the minimum height H S on the scanning lines L 1 to L 3 was determined. The di of each of the scanning lines L 1 to L 3 was averaged to be d. In addition, it was set as d (mm) / t (mm).
(4) Orientation difference by EBSD EBSD (backscattered electron diffraction device, JEOL Ltd. JXA8500F, acceleration voltage 20kV, current 2e-8A) after electrolytic polishing of sample surface after heating at 200 ° C for 30 minutes in (2) The measurement range was 1000 μm × 1000 μm and the step width was 5 μm). The area ratio of crystal grains with an angle difference of 15 degrees or more from the [100] orientation was determined by image analysis. Furthermore, the number of samples having a crystal grain size exceeding 20 μm within the observation range of 1 mm square on the sample surface was visually counted. Then, the sample including this observation range is etched for 2 minutes at room temperature using a 20% solution of ADEKA TECH CL-8 (manufactured by ADEKA CORPORATION), and the image obtained by photographing the etched surface with an optical microscope is binarized. The dark part exceeding 50 μm in the minor axis was counted as a dishdown. The copper foil surface after etching has a shape reflecting the crystal orientation, and the structure with [100] orientation is a plane parallel to the copper foil surface, while the other crystal orientation portions are crystal orientations. Unevenness caused by Therefore, the dishdown portion looks dark with an optical microscope.
4 shows an optical microscope image of the surface of Example 1, and FIG. 5 shows a surface optical microscope image of Comparative Example 3.
（４）オイルピットの面積率
試料表面をコンフォーカル顕微鏡（レーザーテック社製、型番：HD100D）で300×300μmの測定視野につき測定した。測定視野内で試料を光軸(Z軸)方向に移動させ、銅箔表面から１０ｎｍの深さの画像（これをFMS (Focus Scan Memory)画像という）を取り込んだ。そして、銅箔表面から１０ｎｍより深い部分をオイルピットとみなして、２値化処理をおこなった。その画像の例が図６及び図７であり、明るい色の部分がオイルピットである。そして測定視野300×300μmに対して、オイルピットの面積（明るい色の面積）を市販の画像処理ソフトを用いて面積を求め、オイルピットの面積率を算出した。
(4) Area ratio of oil pit The surface of the sample was measured with a confocal microscope (manufactured by Lasertec, model number: HD100D) per 300 × 300 μm measurement field. The sample was moved in the optical axis (Z-axis) direction within the measurement field of view, and an image having a depth of 10 nm (this is called FMS (Focus Scan Memory) image) was captured from the copper foil surface. And the binarization process was performed considering the part deeper than 10 nm from the copper foil surface as an oil pit. The example of the image is FIG.6 and FIG.7, and the bright color part is an oil pit. Then, the area of the oil pit (bright color area) was obtained using a commercially available image processing software with respect to the measurement visual field of 300 × 300 μm, and the area ratio of the oil pit was calculated.
（５）表面の傷
各試料の表面を目視し、圧延方向に10mm以上の長さをもつ傷が、5箇所/m2以上ある場合を×とした。
（６）屈曲性
試料を２００℃で３０分間加熱して再結晶させた後、図８に示す屈曲試験装置により、屈曲疲労寿命の測定を行った。この装置は、発振駆動体４に振動伝達部材３を結合した構造になっており、被試験銅箔１は、矢印で示したねじ２の部分と３の先端部の計４点で装置に固定される。振動部３が上下に駆動すると、銅箔１の中間部は、所定の曲率半径ｒでヘアピン状に屈曲される。本試験では、以下の条件下で屈曲を繰り返した時の破断までの回数を求めた。
なお、板厚が０．０１２ｍｍである場合、試験条件は次の通りである：試験片幅：１２．７ｍｍ、試験片長さ：２００ｍｍ、試験片採取方向：試験片の長さ方向が圧延方向と平行になるように採取、曲率半径ｒ：２．５ｍｍ、振動ストローク：２５ｍｍ、振動速度：１５００回／分。なお、屈曲疲労寿命が３万回以上の場合に、優れた屈曲性を有していると判断した。
また、それぞれ板厚が０．０１８ｍｍ、０．００６ｍｍである場合、板厚が０．０１２ｍｍの場合の屈曲試験と曲げ歪が同じとなるよう、曲率半径ｒをそれぞれ４ｍｍ、１．３ｍｍに変更したが、他の試験条件は同一とした。
(5) Scratches on the surface The surface of each sample was visually observed, and a case where there were 5 or more scratches / m 2 with a length of 10 mm or more in the rolling direction was evaluated as x.
(6) Flexibility After the sample was recrystallized by heating at 200 ° C. for 30 minutes, the flex fatigue life was measured by a flex test apparatus shown in FIG. This apparatus has a structure in which a vibration transmitting member 3 is coupled to an oscillation driver 4, and a copper foil 1 to be tested is fixed to the apparatus at a total of four points including a screw 2 part indicated by an arrow and a tip part of 3. Is done. When the vibration part 3 is driven up and down, the intermediate part of the copper foil 1 is bent into a hairpin shape with a predetermined radius of curvature r. In this test, the number of times until breakage when bending was repeated under the following conditions was determined.
When the plate thickness is 0.012 mm, the test conditions are as follows: test piece width: 12.7 mm, test piece length: 200 mm, test piece sampling direction: the length direction of the test piece is the rolling direction. Extracted to be parallel, radius of curvature r: 2.5 mm, vibration stroke: 25 mm, vibration speed: 1500 times / minute. In addition, when the bending fatigue life was 30,000 times or more, it was judged to have excellent flexibility.
In addition, when the plate thickness is 0.018 mm and 0.006 mm, respectively, the curvature radius r is changed to 4 mm and 1.3 mm so that the bending strain is the same as the bending test when the plate thickness is 0.012 mm. However, other test conditions were the same.
得られた結果を表１に示す。 The obtained results are shown in Table 1.
表１から明らかなように、Ｉ／Ｉ0≧50であり、d /tが0.1以下かつ、オイルピットの面積率が6以上15％以下である各実施例の場合、EBSDによる[100]方位からの角度差が15度以上の結晶粒の面積率が20％未満となり、ディッシュダウンの個数が少なく、さらに銅箔表面に傷がなく、屈曲性にも優れていた。又、各実施例の場合、最終製品のRa/tが0.004以上0.007以下となった。 As is apparent from Table 1, in each example where I / I 0 ≧ 50, d / t is 0.1 or less, and the oil pit area ratio is 6 or more and 15% or less, the [100] orientation by EBSD The area ratio of crystal grains with an angle difference of 15 ° or more from the surface was less than 20%, the number of dishdowns was small, the copper foil surface was not damaged, and the flexibility was excellent. In each example, Ra / t of the final product was 0.004 or more and 0.007 or less.
一方、最終冷間圧延のすべてのパス（最終パス含む）のロールの表面粗さをいずれもRa=0.04μm以下とした比較例１、５の場合、最終パスのRa/tが0.004未満となり、オイルピットの面積率が6%未満になったため銅箔表面に傷が付き、取り扱い性に劣った。
なお、比較例５の場合、表面粗さが小さくオイルピットの面積率が6％未満であるが、最終冷間圧延での圧延加工度を96％と低くしたため、Ｉ／Ｉ0＜50となり、配向度が低く結晶方位が揃っていない状態となった。結晶方位が揃っていない場合、[100]方位からの角度差が15度以上の結晶粒が多く存在することを意味し、この結晶粒の面積率が20％を超えたため、ディッシュダウンも多く発生した。
On the other hand, in the case of Comparative Examples 1 and 5 in which the surface roughness of the rolls of all the passes of the final cold rolling (including the final pass) is Ra = 0.04 μm or less, Ra / t of the final pass is less than 0.004, Since the area ratio of the oil pit was less than 6%, the surface of the copper foil was scratched and the handleability was poor.
In the case of Comparative Example 5, the surface roughness is small and the area ratio of the oil pit is less than 6%. However, since the degree of rolling in the final cold rolling was reduced to 96%, I / I 0 <50, The degree of orientation was low and the crystal orientation was not aligned. If the crystal orientation is not aligned, it means that there are many grains with an angle difference of 15 degrees or more from the [100] orientation, and because the area ratio of these grains exceeded 20%, many dishdowns occurred. did.
最終冷間圧延で、最終パスの手前までのロールの表面粗さをRa=0.06μm以上に粗くし、最終パスのロールの表面粗さをRa=0.05μm以下とした比較例２の場合、最終製品のRa/tが0.004より小さくなったため、銅箔表面に傷が付いて取り扱い性に劣った。又、最終パスの手前では粗いロールを用いたため、オイルピットにはせん断変形帯が発達してしまい、最終パスで粗さの小さいロールを用いてもせん断変形帯が残ることとなり、オイルピットの面積率が６％未満となったため、[100]方位からの角度差が15度以上の結晶粒の面積率が20％を超えた。その結果、ディッシュダウンが多数発生した。 In the case of Comparative Example 2 in which the surface roughness of the roll before the final pass is roughened to Ra = 0.06 μm or more in the final cold rolling and the surface roughness of the roll in the final pass is Ra = 0.05 μm or less, Since the Ra / t of the product was smaller than 0.004, the copper foil surface was scratched and the handleability was poor. In addition, since a rough roll was used before the final pass, a shear deformation band developed in the oil pit, and even if a roll with a small roughness was used in the final pass, a shear deformation band remained, and the area of the oil pit Since the rate was less than 6%, the area ratio of crystal grains with an angle difference of 15 degrees or more from the [100] orientation exceeded 20%. As a result, many dishdowns occurred.
最終冷間圧延で、最終パスの手前までのロールの表面粗さ、及び最終パスのロールの表面粗さをいずれもRa=0.06μm以上に粗くした比較例３、４、６の場合、最終パスの１パス前のRa/tが0.004以上となり、最終パスの前でせん断変形帯が発達したオイルピットが多数発生した。そのため、最終パス後にオイルピット面積率が15％をこえ、[100]方位からの角度差が15度以上の結晶粒の面積率が20％を超えた。その結果、ディッシュダウンが多数発生した。
なお、比較例３、４の場合、最終冷間圧延のすべてのパスのロール表面粗さを粗くしたため、材料内部でせん断変形帯が著しく発達したオイルピットが多数発生した。このため、オイルピット面積率が15％を超えるばかりでなく、銅箔表面の結晶の配向度が低下し、Ｉ／Ｉ0＜50となった。それに応じ、[100]方位からの角度差が15度以上の結晶粒の面積率が20％を超えた。一方、比較例６の場合、最終パスの手前までのロールの粗さを比較例３、４より平滑としたため、Ｉ／Ｉ0は50以上となって比較例３、４よりも高い値となり、屈曲性は良好であった。
In the case of Comparative Examples 3, 4, and 6 in which the surface roughness of the roll before the final pass and the surface roughness of the roll in the final pass are both roughened to Ra = 0.06 μm or more in the final cold rolling, the final pass Ra / t before the first pass became 0.004 or more, and many oil pits with shear deformation zones developed before the final pass. Therefore, the oil pit area ratio exceeded 15% after the final pass, and the area ratio of crystal grains with an angle difference of 15 degrees or more from the [100] orientation exceeded 20%. As a result, many dishdowns occurred.
In the case of Comparative Examples 3 and 4, since the roll surface roughness of all passes of the final cold rolling was increased, many oil pits in which the shear deformation band was remarkably developed inside the material were generated. For this reason, not only the oil pit area ratio exceeded 15%, but also the degree of crystal orientation on the copper foil surface decreased, and I / I 0 <50. Correspondingly, the area ratio of crystal grains with an angle difference of 15 degrees or more from the [100] orientation exceeded 20%. On the other hand, in the case of Comparative Example 6, since the roughness of the roll before the final pass was made smoother than Comparative Examples 3 and 4, I / I 0 was 50 or more, which was higher than Comparative Examples 3 and 4. The flexibility was good.
Claims (3)
銅箔表面で圧延平行方向に長さ175μmで、かつ圧延直角方向にそれぞれ50μm以上離間する３本の走査線上でそれぞれ厚み方向のプロファイルを測定したとき、オイルピットの最大深さに相当する各走査線の厚み方向の最大高さと最小高さの差の平均値dと、前記銅箔の厚みtとの比率d/tが0.1以下であり、
コンフォーカル顕微鏡で測定したときのオイルピットの面積率が6％以上15％以下である圧延銅箔。 The ratio Ra / t between the surface roughness Ra measured at a length of 175 μm in the rolling parallel direction on the copper foil surface and the thickness t of the copper foil is 0.004 or more and 0.007 or less, and is recrystallized by heating at 200 ° C. for 30 minutes. In a state of tempering the structure, the strength (I) of the (200) plane determined by X-ray diffraction of the rolled surface is the strength (I 0 ) of the (200) plane determined by X-ray diffraction of fine powder copper. , I / I 0 ≧ 50,
When the profile in the thickness direction is measured on three scanning lines that are 175μm in length in the rolling parallel direction on the copper foil surface and separated from each other by 50μm or more in the direction perpendicular to the rolling direction, each scan corresponding to the maximum depth of the oil pit The average value d of the difference between the maximum height and the minimum height in the thickness direction of the line, and the ratio d / t between the thickness t of the copper foil is 0.1 or less,
Rolled copper foil with an oil pit area ratio of 6% to 15% as measured with a confocal microscope.
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| KR1020110110868A KR101376037B1 (en) | 2010-10-28 | 2011-10-28 | Rolled copper foil |
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