【発明の詳細な説明】[Detailed description of the invention]
［産業上の利用分野］
本発明は電解銅箔の製造方法に関し、詳しくは
銅箔を電解により得る際の電解液の60容量％以上
を活性炭処理した後20分以内のものを用いること
により、伸び、耐折り曲げ性等を大幅に向上させ
た銅張積層板等に用いられる電解銅箔の製造方法
に関する。
［発明が解決しようとする問題点］
近年、電算機を始めとする電子工業の分野にお
いて、回路の高密度化、高信頼性化を図るため、
回路の多層化が盛んに行なわれつつあり、特に多
層プリント基板が使用されている。
従来、このプリント基板に用いられる銅張積層
板用の銅箔としては、一般に電解銅箔が用いられ
ている。この電解銅箔は、回転する陰極ドラムを
使用し、電解槽中に膠などの添加物を加えた電解
液を通し、回転する陰極ドラム上に、銅を電着さ
せ、ドラムを回転させつつ、銅箔を剥ぎ取る連続
電解方式が用いられている。
この従来法により製造された電解銅箔は、170
℃前後の低温での熱処理によつて、機械的性質が
大きく改良されることはなく、圧延銅箔と比較し
て折り曲げにより破断し易い。
また、この電解銅箔は特に熱間時（例えば180
℃雰囲気）の伸びが3.0％前後またはそれ以下と
低く、銅箔のANSI規格であるIPC−CF−150Eで
は、性能によりクラス１〜４の分類を設けてい
る。特にクラス４では銅箔を熱処理することによ
り、180℃熱間伸び率が4.0％以上である品種を設
けており、熱処理しなければ180℃での伸び率を
4.0％以上にするのは困難とされていた。
さらに、このような電解銅箔は、プリント基
板、特にプリント基板の製造時に、熱応力がかか
る工程で銅箔にクラツクが入つたり、また耐折り
曲げ性を重視するフレキシブルプリント配線板に
供用するには、信頼性が不足していた。
本発明の目的は、従来の電解銅箔では得られな
かつた、常温および熱間での伸びをもち、圧延銅
箔と同等またはそれ以上の機械的性質を備えた電
解銅箔の製造方法を提供することにある。
［問題点を解決するための手段および作用］
本発明者等は、以前からMIL−Ｐ−5510Cで要
求されている熱応力を受けた状態でクラツクが発
生しないような、いわゆる熱間（例えば180℃雰
囲気中）でのが高い電解銅箔の製造について数十
回に亘る試験を重ねてきた。
その中で、電解液の洗浄を目的とした活性炭処
理を実施した際、電解に供する電解液の60容量％
以上を連続して活性炭処理した電解液を使つて、
直ちに電解すると、非常に特異な機械的性質をも
つ電解銅箔が作成できることを見い出し、本発明
に至つた。
すなわち本発明は、活性炭処理された後20分以
内の電解液を60容量％以上含有する電解液を用い
て、電解を行ない、180℃熱間伸び率が8.5％以上
の銅箔を得ることを特徴とする電解銅箔の製造方
法にある。
本発明によつて電解銅箔を得るには、電解に供
する電解液の60容量％以上が活性炭処理したもの
を用いる。活性炭処理したものが60容量％未満に
おいては、高い熱間伸び率を有する電解銅箔が得
られない。また、この活性炭処理した電解液は、
活性炭処理後20分以内のものを用いることが必要
で、20分を超えたものを用いても同様に高い熱間
伸び率を有する電解銅箔は得られない。なお、電
解液の洗浄を目的として、活性炭処理を行なうこ
とは従来より行なわれているが、この活性炭処理
した電解液を本発明のごとく20分以内に電解する
ことはなく、少なくとも１日以上ドラム罐等に貯
蔵することが通常である。
次に本発明の電解同箔の製造方法を第１図に基
づき説明する。
第１図は本発明の電解銅箔を製造する連続電解
方式の装置の一例を示す概略図であり、１は電解
液導入ライン、２は活性炭充填塔、３は電解槽、
４は陰極ドラム、５は不溶性陽極、６は電解銅箔
をそれぞれ示し、また矢線は電解液の流れを示
す。
連続電解方式自体は従来法とほとんど変化ない
が、電解液を電解直前に一定量以上活性炭充填層
を通して、例えば空塔速度30cm／sec以下で処理
し、20分以内に電解に供することに特徴がある。
すなわち、電解液供給ライン１より導入された電
解液の一定量を活性炭充填塔２に導入し、活性炭
処理を行ない、この活性炭処理を行なつて20分以
内の電解液を、未処理の電解液と共に合流させて
電解槽３に導入し、電解を行なう。この電解の際
に、電解槽３中の電解液の60容量％以上が活性炭
処理を行なつて20分以内の電解液であることが本
発明においては必要である。この電解は、陰極ド
ラム４と不溶性陽極５を用いて電解を行ない、陰
極ドラム４に電解銅箔６を析出させる。この電解
の際の電解液組成、電解時間、電流密度、浴温等
は所望により適宜定められる。陰極ドラム４に析
出した電解銅箔６は剥ぎ取られ、銅張積層板等の
用途に用いられる。
このようにして製造した電解銅箔は、電解液の
活性炭による洗浄効果と、電解液中の金属陽イオ
ンの酸化還元作用に起因すると思われる効果の両
者により、従来とは異なる電着状態が形成され、
従来の電解銅箔に比べ、機械的性質はすべてにお
いて良好で、圧延銅箔と比較しても、同等以上の
物性値を表わす。特に熱間伸びは、従来の電解銅
箔に比して飛躍的に増大しており、また熱後の耐
折り曲げ性も極めて良好である。
なお、ここでいう電解液の活性炭による洗浄効
果とは、従来より公知の活性炭による有機物の吸
着除去効果をいう。また、電解液中の金属陽イオ
ンの酸化還元に起因すると思われる効果とは、次
にような効果をいう。すなわち、電解液中に含ま
れる３価の鉄イオンや６価のクロムイオンは電解
時に陰極（銅箔析出面）で還元され、２価の鉄イ
オンや３価のクロムインオとなるが、この還元に
よつて銅の析出結晶面が乱され不規則な結晶とな
り、銅析出物（銅箔）が脆くなるものと推定され
るが、活性炭処理によつてこれら３価の鉄イオン
や６価のクロムイオンが予め還元されるため、電
解時に陰極で還元される金属が殆ど銅のみとなる
ので得られる銅箔の熱間伸び等が良好になるもの
と推定される。なお、活性炭処理後、20分を超え
た場合には、還元された２価の鉄イオンや３価の
クロムイオンが大気中から溶存した酸素によつて
酸化されるために、このような効果が発揮し得な
いものと考えられる。
また、電解時に陽極酸化により２価の鉄イオン
や３価のクロムイオンは酸化され、新たに３価の
鉄イオンや６価のクロムイオンが生成されるた
め、電解液を活性炭で処理した後、20分以内（短
時間内）に電解に供する必要がある。
［実施例］
以下、本発明を実施例および比較例に基づき具
体的に説明する。
実施例 １
電解液として、硫酸銅（CuSO4・5H2Ｏ）280
〜360g／、硫酸100〜150g／の硫酸酸性の硫
酸銅溶液を用い、液温約50℃、電流密度50〜
100A／ｄm2で電解した。
電解は空塔速度30cm／secで、電解に供する電
解液の80容量％を連続活性炭処理をしながら連続
電解を施した。なお、活性炭処理後電解に供する
までの時間は５分間とした。
このようにして得られた35μm電解銅箔の常態
（23℃）、熱後（180℃、１時間加熱後）、熱間
（180℃）の抗張力、伸び、MIT耐折り曲げ性を
IPC−CF−150Eに規定するクラス１〜４の規格
と共に第１表に示すと共に、常態および熱後の電
解銅箔の金属組織を示す顕微鏡写真（1000倍）を
第２図ａおよびｂに示す。
比較例 １
電解液として実施例１と同様のものを用い、活
性炭処理を全く行なわず、実施例１と同様の電解
条件で連続電解を施した。
このようにして得られた35μm電解銅箔の常態、
熱後（180℃、１時間加熱後）、熱間（180℃）の
抗張力、伸び、MIT耐折り曲げ性を第１表に示
すと共に、常態および熱後の電解銅箔の顕微鏡写
真（1000倍）を第３図ａおよびｂに示す。
比較例 ２
35μmの圧延銅箔（プリント回路用圧延銅箔、
TPC−35、三井金属鉱業株式会社製）を用い、
常態、熱後（180℃、１時間加熱後）、熱間（180
℃）の抗張力、伸び、MIT耐折り曲げ性を第１
表に示すと共に、常態および熱後の圧延銅箔の顕
微鏡写真（1000倍）を第４図ａおよびｂに示す。
[Industrial Application Field] The present invention relates to a method for producing electrolytic copper foil, and more specifically, when copper foil is obtained by electrolysis, 60% by volume or more of the electrolytic solution is treated with activated carbon within 20 minutes. This invention relates to a method for producing electrolytic copper foil used for copper-clad laminates, etc., which has significantly improved elongation, bending resistance, etc. [Problems to be solved by the invention] In recent years, in the field of electronics industry including computers, in order to increase the density and reliability of circuits,
2. Description of the Related Art Multilayering of circuits is becoming popular, and multilayer printed circuit boards are in particular being used. Conventionally, electrolytic copper foil has generally been used as the copper foil for copper-clad laminates used in this printed circuit board. This electrolytic copper foil uses a rotating cathode drum, passes an electrolytic solution containing additives such as glue into an electrolytic bath, and electrodeposit copper onto the rotating cathode drum. A continuous electrolytic method is used to strip off the copper foil. The electrolytic copper foil manufactured by this conventional method has 170
The mechanical properties are not significantly improved by heat treatment at a low temperature of around 0.degree. C., and the foil is more likely to break when bent than rolled copper foil. In addition, this electrolytic copper foil is particularly effective when hot (e.g. 180
℃ atmosphere) is low at around 3.0% or less, and the ANSI standard for copper foil, IPC-CF-150E, classifies it into classes 1 to 4 based on performance. In particular, in class 4, by heat-treating the copper foil, we have varieties that have a hot elongation rate of 4.0% or more at 180°C, and if not heat-treated, the elongation rate at 180°C will be 4.0% or more.
It was believed that it would be difficult to achieve a rate of 4.0% or higher. Furthermore, such electrolytic copper foil is prone to cracks in the copper foil during the process of applying thermal stress during the manufacture of printed circuit boards, especially printed circuit boards, and is difficult to use for flexible printed wiring boards where bending resistance is important. was lacking in reliability. An object of the present invention is to provide a method for manufacturing an electrolytic copper foil that has elongation at room temperature and hot temperature and has mechanical properties equivalent to or better than rolled copper foil, which was not possible with conventional electrolytic copper foil. It's about doing. [Means and effects for solving the problem] The present inventors have developed a so-called hot (for example, 180 We have conducted dozens of tests on the production of electrolytic copper foil that has a high temperature (in an atmosphere of 0.3 °C). Among them, when activated carbon treatment is carried out for the purpose of cleaning the electrolyte, 60% by volume of the electrolyte used for electrolysis
Using an electrolyte solution that has been continuously treated with activated carbon,
It has been discovered that electrolytic copper foil with very unique mechanical properties can be created by immediate electrolysis, leading to the present invention. That is, the present invention aims to conduct electrolysis using an electrolytic solution containing 60% by volume or more of an electrolytic solution that has been treated with activated carbon for 20 minutes or more, and to obtain a copper foil with a hot elongation rate of 8.5% or more at 180°C. The feature lies in the manufacturing method of electrolytic copper foil. In order to obtain an electrolytic copper foil according to the present invention, 60% or more by volume of the electrolytic solution used for electrolysis is treated with activated carbon. If the amount of activated carbon treated is less than 60% by volume, an electrolytic copper foil having a high hot elongation rate cannot be obtained. In addition, this activated carbon-treated electrolyte is
It is necessary to use a foil that has been treated with activated carbon for less than 20 minutes, and even if it is used for more than 20 minutes, an electrolytic copper foil having a similarly high hot elongation rate cannot be obtained. Although it has been conventionally practiced to treat the electrolyte with activated carbon for the purpose of cleaning the electrolyte, the activated carbon-treated electrolyte is not electrolyzed within 20 minutes as in the present invention, and is left in the drum for at least one day. It is usually stored in cans, etc. Next, the method for manufacturing the electrolytic foil of the present invention will be explained based on FIG. FIG. 1 is a schematic diagram showing an example of a continuous electrolysis system for manufacturing the electrolytic copper foil of the present invention, in which 1 is an electrolyte introduction line, 2 is an activated carbon packed tower, 3 is an electrolytic tank,
Reference numeral 4 indicates a cathode drum, 5 an insoluble anode, and 6 an electrolytic copper foil, and arrows indicate the flow of electrolyte. The continuous electrolysis method itself is almost the same as the conventional method, but it is characterized by passing a certain amount of the electrolyte through a bed of activated carbon just before electrolysis, processing it at a superficial velocity of 30cm/sec or less, and providing it for electrolysis within 20 minutes. be.
That is, a certain amount of the electrolyte introduced from the electrolyte supply line 1 is introduced into the activated carbon packed tower 2 and treated with activated carbon. They are combined together and introduced into the electrolytic cell 3, where electrolysis is performed. During this electrolysis, it is necessary in the present invention that 60% by volume or more of the electrolytic solution in the electrolytic cell 3 be an electrolytic solution that has been treated with activated carbon for less than 20 minutes. This electrolysis is performed using a cathode drum 4 and an insoluble anode 5, and electrolytic copper foil 6 is deposited on the cathode drum 4. The electrolyte composition, electrolysis time, current density, bath temperature, etc. during this electrolysis are appropriately determined as desired. The electrolytic copper foil 6 deposited on the cathode drum 4 is peeled off and used for applications such as copper-clad laminates. The electrolytic copper foil produced in this way has a different electrodeposition state due to both the cleaning effect of the activated carbon in the electrolyte and the effect that is thought to be caused by the redox action of the metal cations in the electrolyte. is,
Compared to conventional electrolytic copper foil, it has better mechanical properties in all respects, and even when compared to rolled copper foil, it exhibits physical property values that are equal to or better than rolled copper foil. In particular, the hot elongation is dramatically increased compared to conventional electrolytic copper foil, and the bending resistance after heating is also extremely good. Note that the cleaning effect of activated carbon in the electrolytic solution referred to here refers to the adsorption and removal effect of organic matter by conventionally known activated carbon. Further, the effects considered to be caused by the oxidation-reduction of metal cations in the electrolytic solution refer to the following effects. In other words, trivalent iron ions and hexavalent chromium ions contained in the electrolyte are reduced at the cathode (copper foil deposition surface) during electrolysis to become divalent iron ions and trivalent chromium ions. As a result, the copper precipitated crystal plane is disturbed and becomes irregular crystals, making the copper precipitate (copper foil) brittle. However, activated carbon treatment removes these trivalent iron ions and hexavalent chromium ions. is reduced in advance, and the metal reduced at the cathode during electrolysis is almost exclusively copper, which is presumed to improve the hot elongation of the resulting copper foil. If more than 20 minutes elapse after activated carbon treatment, the reduced divalent iron ions and trivalent chromium ions will be oxidized by dissolved oxygen from the atmosphere, resulting in this effect. It is considered that this is not possible. Also, during electrolysis, divalent iron ions and trivalent chromium ions are oxidized by anodic oxidation, and new trivalent iron ions and hexavalent chromium ions are generated, so after treating the electrolyte with activated carbon, It is necessary to subject it to electrolysis within 20 minutes (within a short period of time). [Examples] The present invention will be specifically described below based on Examples and Comparative Examples. Example 1 Copper sulfate (CuSO 4 5H 2 O) 280 as electrolyte
~360g/, sulfuric acid 100~150g/using a sulfuric acid acidic copper sulfate solution, liquid temperature approximately 50℃, current density 50~
Electrolysis was carried out at 100A/ dm2 . Continuous electrolysis was performed at a superficial velocity of 30 cm/sec, and 80% by volume of the electrolyte to be subjected to electrolysis was continuously treated with activated carbon. In addition, the time after activated carbon treatment until it was subjected to electrolysis was 5 minutes. The tensile strength, elongation, and MIT bending resistance of the 35 μm electrolytic copper foil obtained in this way were measured in the normal state (23°C), after heating (180°C, after heating for 1 hour), and during hot (180°C).
Table 1 shows the standards for classes 1 to 4 stipulated in IPC-CF-150E, and micrographs (1000x) showing the metal structure of electrolytic copper foil in normal state and after heating are shown in Figure 2 a and b. . Comparative Example 1 Using the same electrolyte as in Example 1, continuous electrolysis was carried out under the same electrolytic conditions as in Example 1 without any activated carbon treatment. The normal state of the 35 μm electrolytic copper foil obtained in this way,
Table 1 shows the tensile strength, elongation, and MIT bending resistance after heating (180℃, 1 hour), hot (180℃), and micrographs (1000x) of the electrolytic copper foil in normal state and after heating. are shown in Figures 3a and b. Comparative Example 2 35 μm rolled copper foil (rolled copper foil for printed circuits,
Using TPC-35 (manufactured by Mitsui Kinzoku Mining Co., Ltd.),
Normal condition, after heating (180℃, after heating for 1 hour), hot (180℃, after heating for 1 hour)
℃) tensile strength, elongation, and MIT bending resistance are
In addition to the table, micrographs (1000x magnification) of the rolled copper foil in normal state and after heating are shown in FIGS. 4a and 4b.
【表】【table】
【表】
第１表に示されるごとく、実施例１の電解銅箔
は、熱処理することなくIPC−CF−150Eのクラ
ス１〜４のすべての要求物性を満足し、かつ耐折
り曲げ性も好ましい範囲にある。これに対して比
較例１の電解銅箔は、クラス２の常態伸びやクラ
ス３および４の熱間伸びを満足しておらず、熱処
理をすることが必要であり、耐折り曲げ性も実施
例１に比べて低い値を示す。また比較例２の圧延
銅箔は、クラス１〜４の常態伸びを満足しておら
ず、熱処理をすることが必要であり、耐折り曲げ
性も実施例１に比べて低い値を示す。
また、実施例１および比較例１〜２の銅箔の常
態および熱後の金属組織は、第２〜４図ａおよび
ｂにそれぞれ示されるごとく、実施例１の電解銅
箔では、180℃、1hr加熱後に明らかに比較例１の
電解銅箔と異なる巨晶化が認められ（第２図ｂ参
照）、比較例２の圧延銅箔と同様な現象を生じる。
このとき第１表に示すごとく、熱処理後の伸びは
19％と高く、フレキシブルプリント基板に要求さ
れる耐折り曲げ性は非常に改良される。
なお、本試験は35μmの銅箔について行なつた
が、18μmおよび70μmの銅箔においてもほぼ同様
の結果が得られた。
実施例２〜４および比較例３〜４
電解液として、硫酸銅（CuSO4・5H2Ｏ）250
〜280g／、硫酸90〜120g／の硫酸酸性の硫
酸銅溶液を用い、液温約50℃、電流速度50〜
150A／ｄm2で電解した。
電解は空塔速度30cm／secで行ない、電解液の
一部または前部を連続活性炭処理をしたものを用
い、連続電解を施した。なお、活性炭処理後電解
に供するまでの時間は５分間とした。
このようにして得られた35μm電解銅箔の熱間
（180℃）伸びおよび電解に供する電解液の活性炭
処理した割合を第２表に示す。[Table] As shown in Table 1, the electrolytic copper foil of Example 1 satisfies all required physical properties of IPC-CF-150E classes 1 to 4 without heat treatment, and also has bending resistance within a preferable range. It is in. On the other hand, the electrolytic copper foil of Comparative Example 1 does not satisfy the normal elongation of Class 2 or the hot elongation of Classes 3 and 4, and requires heat treatment, and the bending resistance is also lower than that of Example 1. shows a lower value compared to . Further, the rolled copper foil of Comparative Example 2 does not satisfy the normal elongation of classes 1 to 4, requires heat treatment, and exhibits a lower bending resistance than Example 1. In addition, the metal structures of the copper foils of Example 1 and Comparative Examples 1 and 2 in normal state and after heating are shown in FIGS. 2 to 4 a and b, respectively. After heating for 1 hour, megacrystalization, which is clearly different from that of the electrolytic copper foil of Comparative Example 1, was observed (see FIG. 2b), and the same phenomenon as that of the rolled copper foil of Comparative Example 2 occurs.
At this time, as shown in Table 1, the elongation after heat treatment is
It is as high as 19%, and the bending resistance required for flexible printed circuit boards is greatly improved. Although this test was conducted on 35 μm copper foil, almost the same results were obtained with 18 μm and 70 μm copper foil. Examples 2 to 4 and Comparative Examples 3 to 4 As the electrolyte, copper sulfate (CuSO 4 .5H 2 O) 250
~280g/, sulfuric acid 90~120g/using a sulfuric acid acidic copper sulfate solution, liquid temperature approximately 50℃, current speed 50~
Electrolyzed at 150A/ dm2 . Electrolysis was carried out at a superficial velocity of 30 cm/sec, and continuous electrolysis was carried out using a part or front part of the electrolytic solution treated with continuous activated carbon. In addition, the time after activated carbon treatment until it was subjected to electrolysis was 5 minutes. Table 2 shows the hot (180°C) elongation of the 35 μm electrolytic copper foil thus obtained and the activated carbon-treated ratio of the electrolytic solution used for electrolysis.
【表】
第２表に示されるように、活性炭処理した電解
液の割合が60容量％以上の電解液を用いて電解し
て得られた実施例２〜４の電解銅箔は、熱間伸び
が高いのに対し、活性炭処理した電解液の割合が
60容量％未満の電解液を用いて電解して得られた
比較例３〜４の電解銅箔は、熱間伸びが低いこと
が判かる。このことから、本発明においては、活
性炭処理した電解液の割合が60容量％以上の電解
液を用いて電解することが必要である。
実施例５〜７および比較例５
電解液として、硫酸銅（CuSO4・5H2Ｏ）250
〜280g／、硫酸90〜120g／の硫酸酸性の硫
酸銅溶液を用い、液温約50℃、電流密度50〜
150A／ｄm2で電解した。
電解は空塔速度30cm／secで、電解に供する電
解液の80容量％を連続活性炭処理をしながら連続
電解を施した。また電解液の活性炭処理後電解に
供するまでの時間をそれぞれ2.5分、10分、20分、
30分間とした。
このようにして得られた35μm電解銅箔の熱間
（180℃）伸びおよび活性炭処理した電解液の電解
までの時間を第３表に示す。[Table] As shown in Table 2, the electrolytic copper foils of Examples 2 to 4 obtained by electrolysis using an electrolyte in which the proportion of the activated carbon-treated electrolyte was 60% by volume or more were hot-stretched. is high, whereas the percentage of electrolyte treated with activated carbon is
It can be seen that the electrolytic copper foils of Comparative Examples 3 and 4 obtained by electrolysis using an electrolytic solution of less than 60% by volume have low hot elongation. For this reason, in the present invention, it is necessary to perform electrolysis using an electrolytic solution in which the proportion of the activated carbon-treated electrolytic solution is 60% by volume or more. Examples 5 to 7 and Comparative Example 5 As the electrolyte, copper sulfate (CuSO 4 .5H 2 O) 250
Using a sulfuric acid acidic copper sulfate solution of ~280g/, sulfuric acid 90~120g/, liquid temperature of about 50℃, current density of 50~
Electrolyzed at 150A/ dm2 . Continuous electrolysis was performed at a superficial velocity of 30 cm/sec, and 80% by volume of the electrolyte to be subjected to electrolysis was continuously treated with activated carbon. In addition, the times after the electrolyte was treated with activated carbon until it was subjected to electrolysis were 2.5 minutes, 10 minutes, and 20 minutes, respectively.
The duration was 30 minutes. Table 3 shows the hot elongation (at 180° C.) of the 35 μm electrolytic copper foil thus obtained and the time taken to electrolyze the activated carbon-treated electrolyte.
【表】
第３表に示されるように、活性炭処理してから
20分以内の電解液を用いて電解して得られた実施
例５〜７の電解銅箔は、熱間伸びが高いのに対
し、活性炭処理した後30分後の電解液を用いて電
解して得られた比較例５の電解銅箔は、熱間伸び
が低いことが判る。このことから、本発明におい
ては、活性炭処理した後20分以内の電解液を用い
て電解することが必要である。
［発明の効果］
このように、活性炭処理された後20分以内の電
解液を60容量％以上含有する電解液を用い、電解
を行なう本発明の製造方法により得られる電解同
箔は、常態および熱間において、高い抗張力およ
び伸びを示すことから、多層プリント基板等に私
有すれば熱工程での熱応力によるクラツク発生の
心配もなく、また、本発明の電解銅箔は耐折り曲
げ性も良好であるため、フレキシブルプリント配
線板への用途としても、高信頼性を発揮できる。[Table] As shown in Table 3, after activated carbon treatment
The electrolytic copper foils of Examples 5 to 7 obtained by electrolysis using an electrolytic solution within 20 minutes had high hot elongation, whereas the electrolytic copper foils obtained by electrolyzing using an electrolytic solution after 30 minutes of activated carbon treatment had high hot elongation. It can be seen that the electrolytic copper foil obtained in Comparative Example 5 has low hot elongation. Therefore, in the present invention, it is necessary to perform electrolysis using an electrolytic solution within 20 minutes after the activated carbon treatment. [Effects of the Invention] As described above, the electrolytic foil obtained by the manufacturing method of the present invention in which electrolysis is performed using an electrolytic solution containing 60% by volume or more of an electrolytic solution within 20 minutes after being treated with activated carbon can be Since it exhibits high tensile strength and elongation in hot conditions, there is no need to worry about cracks occurring due to thermal stress during thermal processes when used in multilayer printed circuit boards, etc., and the electrolytic copper foil of the present invention also has good bending resistance. Therefore, it can demonstrate high reliability when used in flexible printed wiring boards.
【図面の簡単な説明】[Brief explanation of drawings]
第１図は本発明の電解銅箔を製造する連続電解
方式の装置の一例を示す概略図、第２図ａおよび
ｂは実施例１の常態および熱後の電解銅箔の金属
組織を示す顕微鏡写真（1000倍）、第３図ａおよ
びｂは比較例１の常態および熱後の電解銅箔の金
属組織を示す顕微鏡写真（1000倍）、および第４
図ａおよびｂは比較例２の常態および熱後の圧延
銅箔の金属組織を示す顕微鏡写真（1000倍）。
１……電解液導入ライン、２……活性炭充填
塔、３……電解槽、４……陰極ドラム、５……不
溶性陽極、６……電解銅箔。
FIG. 1 is a schematic diagram showing an example of a continuous electrolysis system for producing the electrolytic copper foil of the present invention, and FIGS. 2 a and b are micrographs showing the metallographic structure of the electrolytic copper foil in the normal state and after heating in Example 1. Photograph (1000x), Figures 3a and b are micrographs (1000x) showing the metal structure of the electrolytic copper foil in the normal state and after heating of Comparative Example 1, and Figure 4
Figures a and b are micrographs (1000x magnification) showing the metallographic structure of the rolled copper foil of Comparative Example 2 in the normal state and after heating. 1... Electrolyte introduction line, 2... Activated carbon packed tower, 3... Electrolytic cell, 4... Cathode drum, 5... Insoluble anode, 6... Electrolytic copper foil.