JP2004131836A - Electrolytic copper foil with carrier foil and its producing method, and copper clad laminated board using electrolytic copper foil with carrier foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a product and a producing method with which the separating strength of a carrier foil is further stabilized after press-working an electrolytic copper foil with the carrier foil using organic agent on a joined boundary layer. <P>SOLUTION: In the electrolytic copper foil with the carrier foil provided with the joint boundary layer 2 at the one side surface of the carrier foil C and provided with the electrolytic copper foil layer CF on this joint boundary layer 2, the layer 2 is formed by using solution containing carboxybenzotriazole and the polymer of methylbenzotriazole and MBTA polymer contained in layer 2 is 2.0-60.0wt%. <P>COPYRIGHT: (C)2004,JPO

Description

【００２５】
このＭＢＴＡの重合体（以上及び以下に於いて、単に「ＭＢＴＡ重合体」と称することとする。）は、ＭＢＴＡからＣＢＴＡを生成する反応を行わせるときの副反応として重合反応が起こり２量体、３量体等として生成することもあり、ＣＢＴＡに混入した状態から溶媒抽出することにより、ＣＢＴＡとＭＢＴＡ重合体とが分離することができるものである。化２に２量体として考えられるＭＢＴＡ重合体の一例を示している。このＭＢＴＡ重合体は、本件発明者等が研究に用いた分析装置の測定限界の範囲で、７量体までが確認できている。このＭＢＴＡ重合体のＣＢＴＡ溶液中の存在量を少なくすると、加熱後のキャリア箔付電解銅箔のキャリア箔の引き剥がし強度の値が不安定になる。従って、本件発明者等は、ＣＢＴＡ中のＭＢＴＡ重合体の存在量をコントロールし、キャリア箔付電解銅箔の接合界面層を形成して、キャリア箔付電解銅箔を製造すれば、キャリア箔の引き剥がし強度の値がバラツクこともなくなり、製品としても非常に安定した品質を備え、製造歩留まりが向上するものとなると考えたのである。
【００２６】
【化２】

【００２７】
以上のような研究結果を基に、請求項には、「キャリア箔の片面に、接合界面層を備え、その接合界面層上に電解銅箔層を備えたキャリア箔付電解銅箔において、当該接合界面層は、ＣＢＴＡとＭＢＴＡ重合体と含む溶液を用いて形成したものであり、且つ、当該接合界面層中に含まれるＭＢＴＡ重合体が２．０ｗｔ％〜６０．０ｗｔ％であることを特徴とするキャリア箔付電解銅箔。」としている。このキャリア箔付電解銅箔１ａの断面を模式的に示したのが、図１である。
【００２８】
このキャリア箔付電解銅箔１ａとは、図１から明らかなように、キャリア箔Ｃと電解銅箔ＣＦとが、あたかも貼り合わされた状態となった製品のことである。そして、このキャリア箔付電解銅箔１ａは、キャリア箔Ｃの付いた状態で、樹脂基材に電解銅箔層ＣＦを張り合わせた後に、キャリア箔Ｃを引き剥がして銅張積層板を得ることに用いられる。以上及び以下において、電解銅箔と電解銅箔層、キャリア箔とキャリア箔層、接合界面と接合界面層とは、それぞれ同じ部位を示し、説明内容に応じて適宜使い分けるものとする。
【００２９】
本件発明に係るキャリア箔付電解銅箔１ａは、キャリア箔Ｃと電解銅箔ＣＦとの間に位置する接合界面２に、ＣＢＴＡとＭＢＴＡ重合体とを含有する混合組成を用いた点に特徴を有する。このＣＢＴＡとＭＢＴＡ重合体とを混合して用いて接合界面層２を形成することで、単独でＣＢＴＡを接合界面層２の形成に用いた場合と比べて、キャリア箔付電解銅箔の連続製造を行う場合の、製品品質の安定化が可能となり、製品歩留まりが飛躍的に向上するのである。また、ＣＢＴＡとの混合組成を採ることなく、ＭＢＴＡ重合体を単独で用いた場合には、加熱後にキャリア箔Ｃは電解銅箔層ＣＦから引き剥がせないものとなるのである。また、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて形成した接合界面層２を備えるキャリア箔付電解銅箔は、従来のキャリア箔付電解銅箔とは全く異なるレベルで、高温プレス成形による加熱後のキャリア箔の引き剥がし強度値の安定性が著しく向上するという特徴をも備えている。
【００３０】
そして、本件発明者等の研究の過程で、次のことが判明してきた。キャリア箔付電解銅箔の接合界面層を、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて形成する場合には、ＣＢＴＡが全く存在しないようになると加熱後のキャリア箔の引き剥がしができず、また、ＭＢＴＡ重合体の量が低くなりすぎると、やはりキャリア箔の引き剥がし強度の安定性が欠如するのである。そこで、本件発明者等が鋭意研究した結果、当該接合界面層中に含まれるＭＢＴＡ重合体が２．０ｗｔ％〜６０．０ｗｔ％の範囲にある場合に、非常に安定した品質を発揮することが分かってきたのである。
【００３１】
即ち、接合界面層を、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて形成することにより、キャリア箔が人間の手作業で容易に剥離させることの出来るレベルに、キャリア箔の引き剥がし強度を安定してコントロールすることが可能となるのである。しかも、ＣＢＴＡのみを用いた接合界面層を備えるキャリア箔付電解銅箔にみられた、高温加熱に弱く、２００℃を越える加熱を受けた後は、キャリア箔の引き剥がし強度が上昇し、手作業による引き剥がしが困難という状況を改善することも出来るのである。即ち、接合界面層の形成にＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いると、２３０℃程度の高温域でのプレス成形を受けても、キャリア箔及び電解銅箔との相互拡散を極めて効果的に抑制し、キャリア箔と電解銅箔との接合強度が、やや増加するものの、プレス成形後までピーラブルタイプのキャリア箔付電解銅箔として十分に使用可能なレベルに維持することが可能なのである。
【００３２】
ここで一例を示すと、３５μｍのキャリア箔に、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて接合界面層を形成し、５μｍの電解銅箔層を形成したものを作成した場合、その接合界面での引き剥がし強度を調べた結果の一例を示すと、加熱前で１５．０ｇｆ／ｃｍ、２３０℃で１時間の加熱後でも１５．２ｇｆ／ｃｍであり、ピーラブルタイプとして求められる容易に手作業で引き剥がせるという特性は維持したものとなっている。
【００３３】
以上に述べたＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いた、キャリア箔上への接合界面層の形成方法について述べつつ、以下説明することとする。キャリア箔上への接合界面層の形成は、上述したＣＢＴＡとＭＢＴＡ重合体とを溶媒に溶解させ、その溶媒中にキャリア箔を浸漬させるか、接合界面層を形成しようとする面に対するシャワーリング、噴霧法、滴下法及び電着法等を用いて行うことができ、特に限定した手法を採用する必要性はない。このときの溶媒中のＣＢＴＡ濃度５０ｐｐｍ〜５０００ｐｐｍ、ＭＢＴＡ重合体の濃度は、濃度２ｐｐｍ〜飽和溶解度量、の範囲とする事が好ましい。この濃度範囲内であれば、形成された接合界面層中のＭＢＴＡ重合体の含有率が、安定的に２．０ｗｔ％〜６０．０ｗｔ％の範囲となるのである。そして、液温に関しては２０〜６０℃の範囲を採用することが望ましい。液温が低すぎると吸着速度が遅くなり、液温が高すぎるとＣＢＴＡ及びＭＢＴＡ重合体の分解が起こりやすくなる傾向が見られるのである。
【００３４】
また、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液による接合界面層の形成は、請求項に記載したように、上述した接合界面の形成方法を複数回繰り返し行うことも可能である。これにより、より精度の高い接合界面層の厚さ制御が可能となる。
【００３５】
ＣＢＴＡとＭＢＴＡ重合体とが共存する溶液中におけるＭＢＴＡ重合体の果たす役割は、次のように考えられる。鋭意研究の結果、ＣＢＴＡとＭＢＴＡ重合体とが共存する溶液を用いて形成した接合界面層は、従来のＣＢＴＡのみを用いて形成した接合界面層に比べ、薄くて均一で、且つ、比重の大きな密度の高い被膜になっていると考えられるようになってきた。即ち、ＭＢＴＡ重合体を含む溶液にキャリア箔として用いる銅箔を浸漬して測定した自然電位と、ＣＢＴＡを含む溶液にキャリア箔として用いる銅箔を浸漬して測定した自然電位とを比較すると、前者の自然電位の方が高い。つまり、キャリア箔の銅成分の溶解が速く、銅との錯体を作りやすい傾向にあると考えられる。例えば、ＣＢＴＡを含む溶液中のＭＢＴＡ重合体の量を徐々に増加させるに連れ、当該自然電位も上昇していく。従って、当該自然電位を観察することで、製造工程におけるＣＢＴＡとＭＢＴＡ重合体とが共存する溶液中のＭＢＴＡ重合体の含有量をモニターすることも可能で、この自然電位を管理指標として用いることが可能となるのである。
【００３６】
接合界面層の形成原理からすると、金属であるキャリア箔にＣＢＴＡとＭＢＴＡ重合体とを含有する溶液で接合界面層を形成する場合、キャリア箔の表面が僅かに溶解し、溶出した金属イオンと、ＣＢＴＡ及びＭＢＴＡ重合体がキャリア箔の表面近傍で錯体を形成し、その錯体がキャリア箔の表面に沈着するという過程を経て、接合界面層となると考えられるのである。従って、上述した自然電位に関する事実から、溶液中のＭＢＴＡ重合体がキャリア箔の表面の金属を溶解させるプロモータとして作用すると考えられる。その結果、キャリア箔の溶解により生じた金属イオンと、ＣＢＴＡ及びＭＢＴＡ重合体が錯体を形成し易くなり、ＣＢＴＡ錯体とＭＢＴＡ錯体とが同時に、キャリア箔表面へ沈着する速度が速くなる。若しくは、ＣＢＴＡ単独の場合に比べて、均一に分散して高密度に沈着すると考えられるのである。結果として、ＣＢＴＡ単独の場合に比べ、薄くても均一な膜厚で高密度な有機被膜としての接合界面層が形成できるのである。しかも、ＭＢＴＡ重合体は、ＣＢＴＡに比べ融点、分解温度が高いので、より安定な接合界面層となる。
【００３７】
本件発明に係るキャリア箔付電解銅箔においては、形成された接合界面層の厚さが非常に重要なものとなる。このことから請求項では、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて形成した接合界面層の厚さが、好ましくは０．５ｎｍ〜１μｍの範囲であることを明らかにしている。
【００３８】
ここに明記した厚さ範囲で、高温プレス成型後も適正なキャリア箔の剥離強度の確保が可能で、しかも電解銅箔層を構成する銅の安定した電解析出が可能となるのである。即ち、接合界面層の厚さが、下限値である０．５ｎｍを下回る厚さでは、プレス成形後の引き剥がし強度が安定しなくなる。上限値である１μｍを越えると、接合界面層上に電解銅箔層を直接形成しようとしたときに、通電状態が不安定になり、銅の析出状況が不安定で、均一な厚さの電解銅箔層の形成が困難となるのである。仮に、長時間掛けて銅を析出させても、バルク銅層と接合界面層との十分な密着性が得られず、安全にプレス成形することのできる、最低限必要とされる引き剥がし強度を得られないものとなる。そして、接合界面層の厚さが更に大きくなると、完全に通電不能な状態となる。接合界面層の厚さはｎｍ〜μｍレベルと、非常に薄いものであるため、その測定には、透過型電子顕微鏡（ＴＥＭ）を用いて確認することが望ましい。
【００３９】
本件明細書にいう「適正な引き剥がし強度」とは、ＪＩＳ−Ｃ−６４８１に準拠して測定した場合の値が、５〜１００ｇｆ／ｃｍの範囲のものと考えている。これは、従来のピーラブルタイプのキャリア箔付電解銅箔の使用実績を考慮し、経験上得られた適正と考えられるキャリア箔と電解銅箔との界面における引き剥がし強度（剥離強度）に、当該キャリア箔付電解銅箔の使用者の理想的な要求値を加味したものとしての範囲である。キャリア箔と電解銅箔との界面における引き剥がし強度が、低いほど剥離作業は容易になる。
【００４０】
しかしながら、引き剥がし強度が、５ｇｆ／ｃｍ未満であると、キャリア箔付電解銅箔を製造しロール状に巻き取る時、銅張積層板のプレス時等に自然にキャリア箔と電解銅箔とが部分的に剥離してふくれ、ズレ等の不良が発生する原因となる。一方、引き剥がし強度が、１００ｇｆ／ｃｍを越えた場合は、作業者が手作業でキャリア箔を引き剥がす際の労働負荷が急激に増すのである。
【００４１】
ここで用いるキャリア箔は、特に材質は限定していない。キャリア箔としてアルミニウム箔、銅箔、表面をメタルコーティングした樹脂フィルムなど、キャリアとして用いることの可能な全てのものを含む概念として用いている。但し、少なくともＣＢＴＡ及びＭＢＴＡ重合体と錯体を形成し、接合界面層の形成が容易となるような金属成分が表面に現れているものでなければならない。また、キャリア箔としての厚さについても、特に限定はない。工業的視点から、箔としての概念は、一般に２００μｍ厚以下のものを箔と称しており、この概念を用いれば足りるものである。
【００４２】
そして、電解銅箔層には、１２μｍ以下の極薄銅箔といわれる電解銅箔のみならず、１２μｍより厚い場合をも含むものである。従来のキャリア箔付電解銅箔は、専ら極薄銅箔の提供を目的として使用されており、本発明に係るキャリア箔付電解銅箔のように１２μｍ以上の電解銅箔層を有するものは市場に供給されていなかった。このような厚い電解銅箔層を備えるキャリア箔付電解銅箔とすることの利点は、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いた有機接合界面層にすることで、キャリア箔層と電解銅箔層とが、高温プレス後に安定して容易に剥離することで、後に説明する新たなキャリア箔付電解銅箔の使用方法が可能となるからである。
【００４３】
ここで、確認的に記載しておくが、図１に示したキャリア箔付電解銅箔１ａは、特殊な用途は別として、銅張積層板及びプリント配線板用途に使用する場合には、電解銅箔層ＣＦの外表面には、微細銅粒４を均一に付着させて用いるものである。これは、一般の電解銅箔の樹脂基材との貼り合わせ面に形成するものと同様の微細銅粒であり、接着した基材に対するアンカー効果を得て、容易に電解銅箔が基材から剥離しないようにするものである。
【００４４】
また、他の請求項に於いては、「キャリア箔の両面に、接合界面層を備え、その各々の接合界面層上に電解銅箔層を備えたキャリア箔付電解銅箔において、当該接合界面層は、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて形成したものであり、且つ、当該接合界面層中に含まれるＭＢＴＡ重合体が２．０ｗｔ％〜６０．０ｗｔ％であることを特徴とするキャリア箔付電解銅箔。」としている。このキャリア箔付電解銅箔１ｂの断面を模式的に示したのが、図２である。先に説明したキャリア箔付電解銅箔１ａが、図１に示す如きキャリア箔Ｃの片面に電解銅箔ＣＦを貼り合わせた形状のものであるのに対して、このキャリア箔付電解銅箔１ｂは、図２の模式断面図で明らかなように、キャリア箔Ｃの両面に電解銅箔ＣＦを貼り合わせた如き形状のものである。
【００４５】
例えば、図１に示したキャリア箔付電解銅箔１ａを用いて、図４のようにレイアップしてプレス加工すれば、確かに中間層の鏡板Ｍの省略も可能となる。ところが、このキャリア箔付電解銅箔１ｂとすることで、更に容易に、銅張積層板の製造時の鏡板を省略することが可能で、しかもプレス成型時の銅箔面への異物混入を完全に防止することが可能となるのである。通常の両面張り銅張積層板の製造は、一般に図３に示すように、上下のプレス板Ｐの間に、ステンレス鋼等の耐熱素材を鏡面仕上げした鏡板Ｍ、銅箔ＣＦ、１枚若しくは複数枚のプリプレグＰＰ、銅箔ＣＦ、鏡板Ｍという順序を繰り返し積層（通称、レイアップと称する。）して、プレス板Ｐを高温加熱し、挟み込むことでプリプレグＰＰの樹脂成分を溶融させ、銅箔ＣＦとプリプレグＰＰとを高温加圧接着させるものである。
【００４６】
このとき、上述のキャリア箔付両面電解銅箔１ｂを用いると、図５に示すように、レイアップした状態の最下層及び最上層ＯＦには、通常の電解銅箔若しくはキャリア箔付片面電解銅箔を用い、それ以外の中間層に位置するものをキャリア箔付両面電解銅箔１ｂとすることで、中間層部に位置する鏡板Ｍを全て省略することができ、プレス成形後の解体時に、キャリア箔Ｃと電解銅箔層ＣＦとの接合界面２から引き剥がせばよいことになる。
【００４７】
中間層の鏡板Ｍが不要になると言うことは、省略した鏡板Ｍ相当の厚さ分だけ、プレス板Ｐのデイライト間に納められる銅箔ＣＦとプリプレグＰＰとの段数を大きくすることができ、１回のプレスで製造する銅張積層板の枚数を増加させることができる。また、伝熱性も良くなり、生産性を向上させることが可能となる。鏡板Ｍの厚さが通常は、０．８ｍｍ〜３．０ｍｍのものが使用され、銅箔ＣＦが３〜５０μｍ厚、プリプレグＰＰの１枚が３０〜１８０μｍ厚であることを考慮すれば、極めて大きな生産性向上効果となることが予測できる。
【００４８】
また、一般的に電解銅箔層ＣＦは、▲１▼導体回路を形成するためのバルク銅層３、▲２▼銅張積層板の基材樹脂との密着性を向上させるための粗化処理層（微細銅粒４）とから構成されるのであるが、本件発明では▲２▼の粗化処理４のみで構成した電解銅箔層をも含む概念としている。従って、上述した２種類のキャリア箔付電解銅箔の「電解銅箔層」を、電解法で析出付着させた微細銅粒４のみで構成するのである。
【００４９】
電解銅箔層を微細銅粒４のみで構成したキャリア箔付電解銅箔１ｃ，１ｄの断面形態を、模式的に図６及び図７に示す。これらのキャリア箔面電解銅箔を用いた銅張積層板の製造時には、微細銅粒４のみがプリプレグと貼り合わせられ、バルク銅層は存在しないことになる。しかし、バルク銅層は導体回路を形成するために必須のものであるから、プリント配線板製造工程において、プリント配線板製造者が、キャリア箔Ｃを除去し、目的に応じたタイミング及び任意の銅メッキ方法により、微細銅粒４の上に所定厚のバルク銅層を形成することができるのである。例えば、その電解銅箔層としての微細銅粒４の表面上にバルク銅層をパネルメッキ法で形成する、又は無電解銅メッキ法を用いて行うことができる。このような方法によれば、バルク銅層の厚さを形成回路の種類に応じて、任意に調節でき、目的の回路幅に応じた適正なエッチング処理が行なえる厚さのバルク銅層とできるのである。従って、このようなプリント配線板製造方法は、作成回路が、より微細になるほど有効なものであり、プリント配線板の回路の高密度化が容易となるのである。
【００５０】
ここで、キャリア箔Ｃに電解銅箔を使用する利点に関して説明する。この説明を、より分かりやすくするために、キャリア箔Ｃとして用いる通常電解銅箔について、ここで簡単に説明することとする。通常電解銅箔は、電解工程と表面処理工程とを経て製造されるものであり、主には電気、電子産業の分野で用いられるプリント配線板製造の基礎材料として用いられるものである。
【００５１】
キャリア箔Ｃに用いる電解銅箔は、１２μｍ〜２１０μｍの厚さのものを用いることが好ましい。このような厚さの電解銅箔を、キャリア箔として使用することで、従来のキャリア箔付電解銅箔に無い種々の有利な効果が得られることになるのである。ここで、キャリア箔として使用する電解銅箔の厚みを１２μｍ〜２１０μｍとしたのは、キャリア箔として９μｍ以下の極薄銅箔の皺の発生を防止する補強材としての役割を果たすためには、最低１２μｍ程度の厚さを必要とし、上限の２１０μｍ以上の厚さとなると、箔という概念を越え、むしろ銅板に近いものであり、巻き取ってロール状態とすることが困難となるからである。
【００５２】
キャリア箔Ｃとして、電解銅箔を使う有利な効果は、次のようになる。アルミ圧延材に代表されるように、圧延法により得られた箔をキャリア箔として用いた場合には、その箔に圧延油が付着することが避けられない、また酸化防止を考慮して油成分を塗布する場合もある。これらをキャリア箔として使用する場合には、キャリア上へ銅を析出させる際の障害となるため、工程内で油分の除去が必要となる。電解銅箔であれば、その製造法からして、不可避的に油分が付着することもなく、たとえ酸化被膜が出来ても、容易に酸洗除去することが可能であり、工程数の削減又は工程管理を容易にすることができるのである。
【００５３】
また、キャリア箔付電解銅箔１ａ〜１ｄのキャリア箔Ｃに電解銅箔を用いると、キャリア箔Ｃと、そのキャリア箔Ｃと貼り合わせた形の電解銅箔ＣＦとは、物性的にも成分的にも同じものと考えることができ、同種のエッチング液で、双方のエッチング処理が可能となる。従って、銅張積層板に加工し、キャリア箔Ｃを引き剥がすことなく、キャリア箔Ｃ上にエッチングレジスト層を形成し、エッチング処理してプリント配線回路を作成した後に、キャリア箔Ｃを引き剥がすことも可能となる。このようにすれば、エッチング加工が終了するまで、銅箔回路の表面は汚染、異物付着から保護され、その後行われるメッキ工程等の作業信頼性を大幅に向上させることが可能となる。
【００５４】
更に、キャリア箔Ｃとした電解銅箔の純度は、９９．９９％以上の純度を有するものである。そして、本発明に係るキャリア箔付電解銅箔１ａ〜１ｄは、その接合界面層２に不純物となる他の金属元素を含んでいない。従って、引き剥がした後のキャリア箔は、リサイクルが容易に可能なものであり、環境保護の観点からも、不必要に産業廃棄物を発生させないものとなる。例えば、キャリア箔を回収し、再溶解して銅のインゴットとすることも可能であるし、再度電解銅箔の製造原料として硫酸で溶解し硫酸銅溶液とすることも可能となるのである。
【００５５】
このときのキャリア箔Ｃとしての電解銅箔には、粗化処理を行っていない未処理箔又は粗化処理を行った表面処理箔のいずれを用いても構わない。未処理箔と表面処理箔とは、その光沢面の粗度に差はなく、その光沢面上に銅箔層を形成すれば何ら銅箔層自体に差異はないのである。図８（ａ）には未処理箔をキャリア箔として用いた場合を、図８（ｂ）には表面処理箔をキャリア箔として用いた場合の断面模式図を示している。これらのキャリア箔付電解銅箔１ｅ，１ｆにおいて、キャリア箔Ｃに未処理箔を用いるか、表面処理箔を用いるかにより、それぞれを用いて得られる銅張積層板の製造時における使用方法が異なってくるのである。
【００５６】
ここで、キャリア箔に未処理箔を用いた場合と表面処理箔を用いた場合の、それぞれのキャリア箔付電解銅箔１ｅ，１ｆの銅張積層板製造において採用できる使用方法について説明する。最初に、第１の銅張積層板の製造方法として、キャリア箔Ｃに未処理箔を用いた場合について説明する。かかる場合のキャリア箔付電解銅箔１ｅは、図８（ａ）に示す断面形状を持つものである。この図から分かるように、プリプレグと接着することの可能な面は、粗面化処理として、微細銅粒４を付着させた電解銅箔層ＣＦの面のみである。
【００５７】
従って、図３で示したようにレイアップし、通常銅箔を使用する場合と同様のプロセスで、当該キャリア箔付電解銅箔１ｅ、プリプレグＰＰ（多層基板の外層銅箔層を形成する場合はプリプレグ及び内層基板）及び鏡板Ｍを用いてプレス成形して銅張積層板を得ることが可能である。また、当該キャリア箔付電解銅箔を用いることで、内層鏡板を省略してのプレス成形も可能となる。即ち、図９に記載したように、プレス板Ｐと直接接触する最外層のみに鏡板Ｍを配し、その２枚の鏡板Ｍの間に、当該キャリア箔付電解銅箔１ｅとプリプレグＰＰとを積層してレイアップするのである。
【００５８】
このレイアップしたときの最上層と最下層とには、１枚のキャリア箔付電解銅箔又は通常銅箔ＯＦが配される。そして、レイアップした際のその他の内層に位置する銅箔は、図９の拡大図に示すように、２枚のキャリア箔付電解銅箔１ｅのキャリア箔Ｃ面とキャリア箔Ｃ面とを背中あわせにし、電解銅箔層ＣＦの粗面化処理を施した面がプリプレグＰＰと接触するように配置する。そして、プレス成形終了後の解体作業時に、キャリア箔Ｃを接合界面層２より剥離させることで、両面基板若しくは多層基板の外層銅箔層の形成が可能となるのである。
【００５９】
これに対し、第２の銅張積層板の製造方法として、キャリア箔Ｃに表面処理箔を用いたキャリア箔付電解銅箔１ｆの、銅張積層板製造における使用方法について説明する。かかる場合のキャリア箔付電解銅箔１ｆは、図８（ｂ）に示す断面形状を持つものである。この図から分かる通りに、プリプレグＰＰと接着することの可能な面は、粗面化処理して微細銅粒４を付着させた面であるから、電解銅箔ＣＦ側のみならず、キャリア箔Ｃ側にも存在することになる。
【００６０】
即ち、２枚の表面処理を施した通常電解銅箔の光沢面同士を貼り合わせた如き形状として、キャリア箔付電解銅箔１ｆが仕上がるのである。従って、キャリア箔をも銅張積層板の電解銅箔として使用することができるのである。このような構造を有するが故に、以下のように使用することができるのである。
【００６１】
当該キャリア箔付電解銅箔１ｆ、プリプレグＰＰ（多層基板の外層銅箔層を形成する場合はプリプレグ及び内層基板）及び鏡板Ｍを用いてプレス成形して銅張積層板を得るのであるが、当該キャリア箔付電解銅箔１ｆを用いることで、内層鏡板を省略してのプレス成形が可能となる。即ち、図１０に記載したように、プレス板Ｐと直接接触する最外層のみに鏡板Ｍを配し、その２枚の鏡板Ｍの間に、当該キャリア箔付電解銅箔１ｆとプリプレグＰＰとをレイアップするのである。
【００６２】
このレイアップしたときの最上層と最下層とには、１枚のキャリア箔付電解銅箔又は通常銅箔ＯＦが配される。そして、レイアップした際のその他の内層に位置する銅箔は、図１０の拡大図に示すように、当該キャリア箔付電解銅箔１ｆの両面にプリプレグＰＰを配置する。このようにして、プレス成形することで、鏡板Ｍを用いることなく成形可能となる。そして、プレス成形終了後の解体作業時に、キャリア箔付電解銅箔１ｆの接合界面層２より剥離させることで、両面基板若しくは多層基板の外層銅箔層の形成が可能となるのである。この方法によれば、一切スクラップとなるものが発生しないと言う利点も併せ持つものである。
【００６３】
以上に述べた本件発明に係るキャリア箔付電解銅箔１ａ〜１ｆの使用方法は、キャリア箔付電解銅箔の接合界面層２の剥離強度を低く維持し、しかも安定化させることができるようになって、初めて実現可能なプレス成形方法である。よって、本件発明に係るキャリア箔付電解銅箔１ａ〜１ｆがもたらす有用な効果は、プリント配線板業界にとっては非常に大きな影響を与えるものであり、銅張積層板の製造コストの低減に大きく寄与するものと言える。
【００６４】
このとき、キャリア箔Ｃとした電解銅箔の光沢面に析出形成した電解銅箔層の厚さを極薄のものとしていれば、その極薄銅箔を貼り付けた銅張積層板を用いて、５０μｍ程度のピッチを有する回路を形成する場合に、銅箔部のエッチング時間を極めて速くすることができ、アスペクト比が非常に良好な微細回路の形成が可能となる。
【００６５】
そして、キャリア箔Ｃとして用いる電解銅箔の粗面上に、ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて接合界面層２を形成し、その接合界面層２上に銅を電解析出させ、その析出銅層を電解銅箔として用いるキャリア箔付電解銅箔とすることもできる。ここで用いるキャリア箔には、前述した未処理箔を用いるものである。図１１に、このキャリア箔付電解銅箔１ｇの断面模式図を示している。この図１１から分かるように、極薄の電解銅箔層は、キャリア箔Ｃである電解銅箔の粗面の凹凸形状に沿って形成されている。即ち、電解銅箔層ＣＦは波打った形状を持つものとなっている。
【００６６】
従って、このキャリア箔付電解銅箔１ｇを用いて銅張積層板を製造すると、波打った形状をそのまま維持してプレス成形されたものとなる。この形状が微細回路を形成する上で、非常に有用に作用するのである。なお、このキャリア箔付電解銅箔１ｇを用いて銅張積層板を製造する際のレイアップ方法については、図３に記載したと同様の手法で同様であるため、重複した記載は省略するものとする。
【００６７】
微細回路の形成を行うために必要な電解銅箔に求められる要因を大まかに捉えれば、▲１▼良好なエッチングレジストとの密着性の確保、▲２▼良好な露光状態の確保、▲３▼速いエッチング時間、▲４▼その他引き剥がし強度（耐薬品性等を含む）等の物理的特性と考えられる。ここに言う諸特性のほとんどが良好なものとなるが、中でも、波打った形状を持つ電解銅箔は、良好なエッチングレジストとの密着性の確保と、良好な露光状態の確保に主に寄与するものである。
【００６８】
波打った形状を持つ電解銅箔を、銅張積層板に用いることで、各種レジスト類と電解銅箔表面との密着性が向上する。例えば、エッチングレジストとの密着性が向上すれば、銅箔とエッチングレジストとの接合界面に対するエッチング液の侵入を防止でき、良好なアスペクト比を持つ回路断面の形成が可能となるため、インピーダンスコントロール等を考慮した微細回路の形成が容易になる。また、波打った表面形状を持つことにより、通常のフラットな光沢面にくらべ、艶消しに近い光沢となっている。この結果、エッチングパターンのエッチングレジストに対し、露光時の露光光の余分な散乱を抑制することが可能であり、回路パターンのエッジ部での、いわゆる露光ボケの影響を軽減することができるのである。更に、レーザー穴明け加工性を改善することも可能となるのである。
【００６９】
また、波打った形状を持つ電解銅箔層を備えた銅張積層板に、銅メッキ処理を施すと、銅箔表面とメッキ層との界面での剥離強度が向上するとの結果が得られている。従って、当該キャリア箔付電解銅箔を用いることで、メッキ層の密着性が向上すると言える。
【００７０】
この結果、通常の電解銅箔を使用して５０μｍピッチレベルの微細回路を形成した際に見られる回路断面のアスペクト比の悪化を防止し、理想的なアスペクト比を持つ回路形成が可能となる。しかも、エッチングレジストの露光ボケが少ないため、形成回路のエッジ部の直線安定性が向上し、微細回路の形成を容易なものとできる。形成回路のエッジ部の直線安定性が向上するということは、エッチングで形成した回路の上部エッジ部及び下部エッジ部の直線性が優れていること、及びプリント配線板への部品実装に用いるランド部等の円形回路部のエッジ形状等の形成回路全体のエッジ部が滑らかであることを意味している。即ち、回路の直線安定性が優れるため、プリント配線板として使用する際に発生する可能性のある銅マイグレーションの抑制、高周波信号を用いた場合の回路エッジ部の突起部からの放電現象の解消等も可能となるといえる。
【００７１】
以上に述べた本件発明に係るキャリア箔付電解銅箔１ａ〜１ｇの使用方法は、前述したと同様に、キャリア箔付電解銅箔１ａ〜１ｇの接合界面層２の剥離強度を低く維持し、しかも安定化させることができるようになり、初めて実現可能なプレス成形方法である。
【００７２】
そして、キャリア箔付電解銅箔の製造方法としては、上述したように、キャリア箔の表面への接合界面の形成は、ＣＢＴＡを５０ｐｐｍ〜５０００ｐｐｍ、ＭＢＴＡ重合体を２ｐｐｍ〜飽和溶解量含有する溶液を用いて、当該有機剤を吸着させることにより有機被膜として形成することを特徴とする。本件発明に係るキャリア箔付電解銅箔の製造フローは、ＣＢＴＡのみを用いた接合界面層を備えるキャリア箔付電解銅箔の製造の不具合を確かめるために行った冒頭の製造方法とフロー自体は同様であるため、図１２を参照しつつ、各工程に必要な概念のみを述べることとする。
【００７３】
最初に行うキャリア箔の酸洗処理は、キャリア箔に付いた油脂成分を完全に除去する脱脂処理及び金属箔を用いた場合の表面酸化被膜除去を目的に行うものである。この酸溶液にキャリア箔を通過させることで、キャリア箔の清浄化を図り、以下の工程での均一付着性及び電着性等を確保するのである。この酸洗処理には、塩酸系溶液、硫酸系溶液、硫酸−過酸化水素系溶液等種々の溶液を用いることが可能で、特に限定する必要性はない。そして、その溶液濃度や液温等に関しては、生産ラインの特質に応じて調整すれば足りるものである。
【００７４】
酸洗処理の後に行われる接合界面層の形成は、上述したＣＢＴＡとＭＢＴＡ重合体とを含有する溶液の混合溶液を用い、キャリア箔の片面若しくは両面に接合界面層を形成する処理を行う工程のことである。この接合界面層の形成は、▲１▼ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液中にキャリア箔を浸漬する方法、▲２▼ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を、接合界面層を形成するキャリア箔の表面に対し、シャワーリング若しくは滴下する等する方法、▲３▼ＣＢＴＡとＭＢＴＡ重合体とを含有する溶液を用いて、接合界面層を形成するキャリア箔の表面に対し電着させる方法等を採用することができる。
【００７５】
接合界面層の形成が終了すると、続いて、その接合界面層上に電解銅箔層の形成が行われる。最初に、電解銅箔層が微細銅粒のみで構成されたキャリア箔付電解銅箔を除き、バルク銅層の形成が行われる。バルク銅層の形成を行う場合に用いる銅電解液は、硫酸銅系溶液、ピロ燐酸銅系溶液等の銅イオン供給源として使用可能な溶液を用い、特に限定されるものではない。例えば、硫酸銅系溶液であれば、濃度が銅３０〜１００ｇ／ｌ、硫酸５０〜２００ｇ／ｌ、液温３０〜８０℃、電流密度１〜１００Ａ／ｄｍ^２の条件、ピロ燐酸銅系溶液であれば、濃度が銅１０〜５０ｇ／ｌ、ピロ燐酸カリウム１００〜７００ｇ／ｌ、液温３０〜６０℃、ｐＨ８〜１２、電流密度１〜１０Ａ／ｄｍ^２の条件とする等である。ここでは、当該溶液中に、接合界面層を形成したキャリア箔を浸漬し、接合界面層を形成したキャリア箔の面に対しアノード電極を平行配置し、キャリア箔自体をカソード分極することで、バルク銅層を形成する銅成分を接合界面層上に均一且つ平滑に電析させるのである。
【００７６】
そして、バルク銅層の形成が終了すると、次にはバルク銅層の表面に微細銅粒を形成するのである。微細銅粒を付着させる場合には、バルク銅層の上に微細銅粒を析出付着させ、その後、この微細銅粒の脱落を防止するための被せメッキを行うのが一般的である。なお、電解銅箔層を微細銅粒のみで構成する場合には、電解銅箔層の形成が、バルク銅層の形成を省略し、この工程から始まることになる。
【００７７】
バルク銅層の上に微細銅粒を析出付着させるには、前述のバルク銅の形成槽で用いたと同種の銅電解液を用いる。但し、バルク銅の形成槽内で用いられる電解条件は平滑メッキ条件が採用されるのに対し、ここでの電解条件はヤケメッキの条件が採用される。従って、一般的にバルク銅層の上に微細銅粒を析出付着させる工程で用いる溶液濃度は、バルク銅の形成層内で用いる溶液濃度に比べ、ヤケメッキ条件を作り出しやすいよう、低い濃度となっている。このヤケメッキ条件は、特に限定されるものではなく、生産ラインの特質を考慮して定められるものである。例えば、硫酸銅系溶液を用いるのであれば、濃度が銅５〜２０ｇ／ｌ、硫酸５０〜２００ｇ／ｌ、その他必要に応じた添加剤（α−ナフトキノリン、デキストリン、ニカワ、チオ尿素等）、液温１５〜４０℃、電流密度１０〜５０Ａ／ｄｍ^２の条件とする等である。
【００７８】
そして、微細銅粒の脱落を防止するための被せメッキには、析出付着させた微細銅粒の脱落を防止するために、平滑メッキ条件で微細銅粒を被覆するように銅を均一析出させるのである。従って、ここでは前述のバルク銅の形成槽で用いたと同様の溶液を銅イオンの供給源として用いることができる。この平滑メッキ条件は、特に限定されるものではなく、生産ラインの特質を考慮して定められるものである。例えば、硫酸銅系溶液を用いるのであれば、濃度が銅５０〜８０ｇ／ｌ、硫酸５０〜１５０ｇ／ｌ、液温４０〜５０℃、電流密度１０〜５０Ａ／ｄｍ^２の条件とする等である。
【００７９】
上述のようにして、キャリア箔付電解銅箔の基本的構成が出来上がると、通常は次に防錆処理が施される。この防錆処理は、銅張積層板及びプリント配線板の製造過程で支障をきたすことの無いよう、電解銅箔層の表面が酸化腐食することを防止するためのものである。防錆処理としては、ベンゾトリアゾール、イミダゾール等を用いる有機防錆、若しくは亜鉛、クロメート、亜鉛合金等を用いる無機防錆のいずれを採用しても問題はない。キャリア箔付電解銅箔の使用目的に合わせた防錆を選択すればよい。有機防錆の場合は、有機防錆剤を浸漬塗布、シャワーリング塗布、電着法等の手法を採用することが可能となる。
【００８０】
無機防錆の場合は、電解で防錆元素を電解銅箔層の表面上に析出させる方法、その他いわゆる置換析出法等を用いることが可能である。例えば、亜鉛防錆処理を行うとして、ピロ燐酸亜鉛メッキ浴、シアン化亜鉛メッキ浴、硫酸亜鉛メッキ浴等を用いることが可能である。例えば、ピロ燐酸亜鉛メッキ浴であれば、濃度が亜鉛５〜３０ｇ／ｌ、ピロ燐酸カリウム５０〜５００ｇ／ｌ、液温２０〜５０℃、ｐＨ９〜１２、電流密度０．３〜１０Ａ／ｄｍ^２の条件とする等である。
【００８１】
防錆処理が終了すると、水洗して、乾燥処理することで、完成したキャリア箔付電解銅箔となるのである。なお、各工程間には、適宜、水洗出来るような手段を設けて、前工程の溶液の後工程への持ち込みを防止する操作は、当然のものであるため、製造フローの説明としては、敢えて明記していない。
【００８２】
以上の述べた工程を経て、本件発明に係るキャリア箔付電解銅箔の製造が行われるのである。そして、これらのキャリア箔付電解銅箔は、主にプリント配線板製造の基礎材料として用いられる銅張積層板に加工されることとなる。ここでいう銅張積層板とは、片面基板、両面基板及び多層基板の全ての層構成の概念を含み、しかも基材材質は、リジット系の基板に限らず、いわゆるＴＡＢ、ＣＯＢ等の特殊基板をも包含するフレキシブル基板、ハイブリッド基板等の全てを含むものである。
【００８３】
【発明の実施の形態】
以下、本発明に係るキャリア箔付電解銅箔の製造方法を用いて、キャリア箔付電解銅箔を製造した。そして、銅張積層板にプレス成形した後に、キャリア箔の電解銅箔層からの引き剥がし強度及びその安定性を確認するため、得られたキャリア箔付電解銅箔にプレス成形と同等の加熱処理を行い、加熱後のキャリア箔の引き剥がし強度を測定し、その結果を示すこととする。ここではキャリア箔に電解銅箔を用いた場合を中心に説明するものとする。
【００８４】
第１実施形態：　本実施形態においては、キャリア箔Ｃに１８μｍ厚のグレード３に分類される粗化処理及び防錆処理を行っていない電解銅箔を用いた。以下、各工程の順序に従って説明を行う。
【００８５】
最初にキャリア箔Ｃの酸洗処理を行った。酸洗処理槽の内部に、濃度１５０ｇ／ｌ、液温３０℃の希硫酸溶液を満し、この中にキャリア箔Ｃが３０秒浸漬されるようにして、キャリア箔Ｃに付いた油脂成分を除去し、表面酸化被膜の除去を行った。
【００８６】
酸洗処理の終了したキャリア箔Ｃの表面に、接合界面層２を形成した。この接合界面層２の形成は、酸洗処理の終了し水洗されたキャリア箔Ｃが、ＣＢＴＡ濃度３５００ｐｐｍ、ＭＢＴＡ重合体５ｐｐｍを含み、液温３５℃、ｐＨ５の水溶液中に３０秒浸漬されるようにして、キャリア箔Ｃの表面に接合界面層２を形成し、水洗した。ここで得られた接合界面層２の厚さは、平均１０ｎｍであった。
【００８７】
接合界面層２の形成が終了すると、キャリア箔Ｃの両面に形成した接合界面層２の片面側に、電解銅箔層ＣＦを構成するバルク銅層３を形成した。バルク銅層３の形成は、銅電解槽内に、硫酸濃度１５０ｇ／ｌ、銅濃度６５ｇ／ｌ、液温４５℃の硫酸銅溶液を満たした。そして、キャリア箔自体をカソード分極するため、この溶液中に浸漬した接合界面層２を形成した後のキャリア箔Ｃの一面側と、アノード電極となるステンレス板を平行になるように離間配置し電解した。以下、電解法を採用する場合には同様の手法を採用した。そして、電流密度１５Ａ／ｄｍ^２の平滑メッキ条件で電解し、３μｍ厚のバルク銅層３をキャリア箔Ｃの片面側の接合界面層上に形成した。
【００８８】
バルク銅層３の形成が終了すると、次にはバルク銅層３の表面に粗化処理を施した。粗化処理は、まず微細銅粒４を電解銅箔層ＣＦに付着形成し、更に、微細銅粒４の脱落を防止するための被せメッキを行った。
【００８９】
微細銅粒４の付着形成は、硫酸銅溶液であって、硫酸濃度が１００ｇ／ｌ、銅濃度が１８ｇ／ｌ、液温２５℃の銅電解液を用い、電流密度１０Ａ／ｄｍ^２のヤケメッキ条件で１０秒間電解することにより行った。
【００９０】
そして、被せメッキは、硫酸銅溶液であって、硫酸濃度１５０ｇ／ｌ、銅濃度６５ｇ／ｌ、液温４５℃の銅電解液を用い、電流密度１５Ａ／ｄｍ^２の平滑メッキ条件で２０秒間電解することにより行った。
【００９１】
粗化処理が終了すると、キャリア箔Ｃと粗化処理の終了した電解銅箔面の腐食防止を目的として、防錆処理工程で、電解法により亜鉛を両面に析出させることで防錆処理を行った。ここでの亜鉛を電析させる条件は、硫酸亜鉛浴を用い、硫酸濃度７０ｇ／ｌ、亜鉛濃度２０ｇ／ｌの濃度とし、液温４０℃、電流密度１５Ａ／ｄｍ^２の条件を採用した。ここまでの工程を経て、キャリア箔付電解銅箔１を製造した。
【００９２】
最終的に防錆処理が終了すると、水洗し、最終的に乾燥することにより完成したキャリア箔付電解銅箔１ａが得られた。
【００９３】
このキャリア箔付電解銅箔１ａの、キャリア箔層Ｃと電解銅箔層ＣＦとの引き剥がし強度を測定した。以下に示す本件明細書における各実施形態の引き剥がし強度の値は、全て１０ロット分の平均値であり、引き剥がし強度の安定性を対比する指標として１０ロット測定したときの１時間加熱後の引き剥がし強度の標準偏差を示した。その結果、当該引き剥がし強度は加熱前１８ｇｆ／ｃｍ、１８０℃で１時間加熱後は２０ｇｆ／ｃｍ（標準偏差０．５４ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２２ｇｆ／ｃｍ（標準偏差０．８８ｇｆ／ｃｍ）であった。これらの値を、以下に述べる比較例と対比して判断するに、プレス加工時のハンドリングによるキャリア箔Ｃの剥離が十分に防止できる信頼性を確保し、加熱後も極めて容易に手作業でキャリア箔の除去が可能で、しかも、標準偏差が著しく小さくなっていることから従来のキャリア箔付電解銅箔の持つ品質安定性を遙かに超えた製品である理想的な製品であることが分かるのである。
【００９４】
第２実施形態：　本実施形態においては、キャリア箔Ｃに１８μｍ厚のグレード３に分類される粗化処理及び防錆処理を行っていない電解銅箔を用い、酸洗処理、接合界面層２の形成までは、第１実施形態と同様の方法で行った。従って、これらの説明は、重複した記載を避けるため、ここでは省略する。
【００９５】
接合界面層２の形成が終了すると、キャリア箔Ｃの両面に形成した接合界面層２の片面側に、電解銅箔層ＣＦを形成したが、ここでの電解銅箔層ＣＦは微細銅粒４のみのタイプとした。従って、接合界面層２の形成が終了すると、次には接合界面層２の表面に粗化処理を施した。粗化処理は、まず微細銅粒４を電解銅箔層ＣＦに付着形成し、更に、微細銅粒４の脱落を防止するための被せメッキを行った。このときの微細銅粒４の形成、及び、被せメッキは第１実施形態と同様の方法を採用した。但し、微細銅粒４の付着形成は、同様のヤケメッキ条件で２０秒間の電解することとして、電解時間を長くして充分な量の微細銅粒４を付着させた点が異なるのみである。
【００９６】
以上のようにして、電解銅箔層ＣＦの形成が終了すると、第１実施形態と同様の方法で、防錆処理を行い、水洗し、最終的に乾燥することにより完成したキャリア箔付電解銅箔１ｂが得られた。
【００９７】
このキャリア箔付電解銅箔１ｂの、キャリア箔層Ｃと電解銅箔層ＣＦとの引き剥がし強度を測定した。以下に示す本件明細書における各実施形態の引き剥がし強度の値は、全て１０ロット分の平均値であり、引き剥がし強度の安定性を対比する指標として１０ロット測定したときの１時間加熱後の引き剥がし強度の標準偏差を示した。その結果、当該引き剥がし強度は加熱前２０ｇｆ／ｃｍ、１８０℃で１時間加熱後は２１ｇｆ／ｃｍ（標準偏差０．５４ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２５ｇｆ／ｃｍ（標準偏差０．８８ｇｆ／ｃｍ）であった。これらの値を、以下に述べる比較例と対比して判断するに、プレス加工時のハンドリングによるキャリア箔Ｃの自然剥離が十分に防止できる信頼性を確保し、加熱後も極めて容易に手作業でキャリア箔Ｃの除去が可能で、しかも、標準偏差が著しく小さくなっていることから従来のキャリア箔付電解銅箔の持つ品質安定性を遙かに超えた製品である理想的な製品であることが分かるのである。
【００９８】
第３実施形態：　本実施形態においては、キャリア箔Ｃに１８μｍ厚の粗化処理及び防錆処理を行っていない圧延銅箔を用いた。以下、各工程の順序に従って説明を行う。
【００９９】
最初にキャリア箔Ｃである圧延箔を、酸洗処理し、その表面に接合界面層２を形成するまでは、第１実施形態と同様の方法で行った。従って、これらの説明は、重複した記載を避けるため、ここでは省略する。ここで得られた接合界面層２の厚さは、平均１１ｎｍであった。
【０１００】
接合界面層２の形成が終了すると、キャリア箔Ｃの両面に電解銅箔層ＣＦを備えたキャリア箔付銅箔１ｃを製造するため、キャリア箔Ｃの両面に形成した接合界面層２の、それぞれの表面に、電解銅箔層ＣＦを構成するバルク銅層３を形成した。バルク銅層３の形成は、銅電解槽内に、硫酸濃度１５０ｇ／ｌ、銅濃度６５ｇ／ｌ、液温４５℃の硫酸銅溶液を満たした。そして、キャリア箔Ｃ自体をカソード分極するため、この溶液中に浸漬した接合界面層２を形成した後のキャリア箔Ｃの両面のそれぞれに、アノード電極となるステンレス板を平行になるように離間配置して電解した。以下、電解法を採用する場合には同様の手法を採用した。そして、電流密度１５Ａ／ｄｍ^２の平滑メッキ条件で電解し、３μｍ厚のバルク銅層３をキャリア箔Ｃの両面の各々の接合界面層２上に形成した。
【０１０１】
両面のバルク銅層３形成が終了すると、次には両面のそれぞれのバルク銅層３の表面に粗化処理を施した。粗化処理は、まず微細銅粒４をバルク銅層３上に付着形成し、更に、微細銅粒４の脱落を防止するための被せメッキを行った。
【０１０２】
微細銅粒４の付着形成及び被せメッキは、第１実施形態と同様の方法を採用した。従って、重複した記載を避けるため、ここでの説明は省略する。以上のようにして、電解銅箔層ＣＦの形成が終了すると、第１実施形態と同様の方法で、両面に防錆処理を行い、水洗し、最終的に乾燥することにより完成したキャリア箔付電解銅箔１ｃを得た。
【０１０３】
このキャリア箔付電解銅箔１ｃの、キャリア箔層Ｃと電解銅箔層ＣＦとの引き剥がし強度を測定した。その結果、一面側のキャリア箔Ｃの当該引き剥がし強度は加熱前１８ｇｆ／ｃｍ、１８０℃で１時間加熱後は１９ｇｆ／ｃｍ（標準偏差０．５４ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２１ｇｆ／ｃｍ（標準偏差０．８８ｇｆ／ｃｍ）であった。また、他面側のキャリア箔Ｃの当該引き剥がし強度は加熱前２０ｇｆ／ｃｍ、１８０℃で１時間加熱後は２２ｇｆ／ｃｍ（標準偏差０．５４ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２４ｇｆ／ｃｍ（標準偏差０．８８ｇｆ／ｃｍ）であった。
【０１０４】
これらの値を、以下に述べる比較例と対比して判断するに、プレス加工時のハンドリングによるキャリア箔Ｃの自然剥離が十分に防止できる信頼性を確保し、加熱後も極めて容易に手作業でキャリア箔Ｃの除去が可能で、しかも、標準偏差が著しく小さくなっていることから従来のキャリア箔付電解銅箔の持つ品質安定性を遙かに超えた製品である理想的な製品であることが分かるのである。
【０１０５】
第４実施形態：　本実施形態においては、キャリア箔Ｃに１８μｍ厚の粗化処理及び防錆処理を行っていない圧延銅箔を用い、酸洗処理、接合界面層の形成までは、第３実施形態と同様の方法で行った。従って、これらの説明は、重複した記載を避けるため、ここでは省略する。
【０１０６】
接合界面層２の形成が終了すると、キャリア箔Ｃの両面に形成した接合界面層２の両面側に、電解銅箔層ＣＦを形成したが、ここでの電解銅箔層ＣＦは微細銅粒４のみのタイプとした。従って、接合界面層２の形成が終了すると、次には接合界面層２の表面に粗化処理を施した。粗化処理は、まず微細銅粒４を接合界面層２上に付着形成し、更に、微細銅粒４の脱落を防止するための被せメッキを行った。このときの微細銅粒４の形成、及び、被せメッキは第３実施形態と同様の方法を採用した。但し、微細銅粒４の付着形成は、同様のヤケメッキ条件で２０秒間の電解することとして、電解時間を長くして充分な量の微細銅粒４を付着させた点が異なるのみである。
【０１０７】
以上のようにして、電解銅箔層ＣＦの形成が終了すると、第１実施形態と同様の方法で、防錆処理を行い、水洗し、最終的に乾燥することにより完成したキャリア箔付電解銅箔１ｄが得られた。
【０１０８】
このキャリア箔付電解銅箔１ｄの、キャリア箔層Ｃと電解銅箔層ＣＦとの引き剥がし強度を測定した。その結果、一面側のキャリア箔Ｃの当該引き剥がし強度は加熱前１８ｇｆ／ｃｍ、１８０℃で１時間加熱後は１９ｇｆ／ｃｍ（標準偏差０．５４ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２１ｇｆ／ｃｍ（標準偏差０．８８ｇｆ／ｃｍ）であった。また、他面側のキャリア箔Ｃの当該引き剥がし強度は加熱前２０ｇｆ／ｃｍ、１８０℃で１時間加熱後は２２ｇｆ／ｃｍ（標準偏差０．５４ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２４ｇｆ／ｃｍ（標準偏差０．８８ｇｆ／ｃｍ）であった。
【０１０９】
これらの値を、以下に述べる比較例と対比して判断するに、プレス加工時のハンドリングによるキャリア箔の剥離が十分に防止できる信頼性を確保し、加熱後も極めて容易に手作業でキャリア箔の除去が可能で、しかも、標準偏差が著しく小さくなっていることから従来のキャリア箔付電解銅箔の持つ品質安定性を遙かに超えた製品である理想的な製品であることが分かるのである。
【０１１０】
比較例：　本比較例においては、キャリア箔に１８μｍ厚のグレード３に分類される粗化処理及び防錆処理を行っていない電解銅箔を用いた。以下、各工程の順序に従って説明を行う。
【０１１１】
最初にキャリア箔の酸洗処理を行った。酸洗処理槽の内部に、濃度１５０ｇ／ｌ、液温３０℃の希硫酸溶液を満し、この中にキャリア箔が３０秒浸漬されるようにして、キャリア箔３に付いた油脂成分を除去し、表面酸化被膜の除去を行った。
【０１１２】
酸洗処理の終了したキャリア箔３の表面に、接合界面層を形成した。この接合界面層の形成は、酸洗処理の終了し水洗されたキャリア箔が、ＣＢＴＡのみを濃度５ｇ／ｌとして含み、液温４０℃、ｐＨ５の水溶液中に３０秒浸漬されるようにして、キャリア箔３の表面に接合界面層８を形成し、水洗した。ここで得られたＣＢＴＡのみで形成された接合界面層８の厚さは、平均１１ｎｍであった。しかしながら、このＣＢＴＡのみで構成した接合界面層は、ＴＥＭで観察する場所により、２ｎｍ〜２５ｎｍの間でばらついており、膜厚の均一性に欠けるものであった。
【０１１３】
接合界面層の形成が終了すると、キャリア箔の両面に形成した接合界面層の片面側に、電解銅箔層を構成するバルク銅層を形成するバルク銅層形成、微細銅粒を付着させ被せメッキを行う粗化処理、防錆処理、乾燥処理を行って、比較用のキャリア箔付電解銅箔を製造した。これらの各製造条件は、第１実施形態と同様であるため、重複した記載を避けるため、ここでの詳細な説明は省略する。
【０１１４】
このキャリア箔付電解銅箔の、キャリア箔層と電解銅箔層との引き剥がし強度を測定した。以下に示す本件明細書における各実施形態の引き剥がし強度の値は、全て１０ロット分の平均値であり、引き剥がし強度の安定性を対比する指標として１０ロット測定したときの１時間加熱後の引き剥がし強度の標準偏差を示した。その結果、当該引き剥がし強度は加熱前１８ｇｆ／ｃｍ、１８０℃で１時間加熱後は２５ｇｆ／ｃｍ（標準偏差２．７３ｇｆ／ｃｍ）、２３０℃で１時間加熱後は２５７ｇｆ／ｃｍ（標準偏差１２．３１ｇｆ／ｃｍ）であった。これらの値を、以上に述べた各実施形態と対比して判断するに、加熱温度が高くなるにつれ、キャリア箔の引き剥がし強度が大きくなり、特に２３０℃の加熱後では著しき高い値となり、殆ど容易に手作業でキャリア箔の除去が可能と言えるものではなくなっている。しかも、標準偏差も各実施形態と比較しても大きくなっているのである。
【０１１５】
【発明の効果】
本発明に係るキャリア箔付電解銅箔は、接合界面層の形成にＣＢＴＡとＭＢＴＡ重合体とを含む溶液を用いることで、加熱後のキャリア箔層と電解銅箔層との界面での剥離が非常に小さな力で容易に行え、且つ、製品間の品質のバラツキが非常に小さくなる。しかも、本件に係るキャリア箔付電解銅箔の製造は、接合界面層の形成にＣＢＴＡとＭＢＴＡ重合体とを含有する水溶液を用いることに特徴を有するが、工程変動が起こりにくく、非常に安定した製造プロセスとなるため、製品の製造歩留まりが飛躍的に向上することになるのである。
【図面の簡単な説明】
【図１】キャリア箔付電解銅箔の断面模式図。
【図２】キャリア箔付電解銅箔の断面模式図。
【図３】プレス成形時のレイアップ構成を示した模式図。
【図４】プレス成形時のレイアップ構成を示した模式図。
【図５】プレス成形時のレイアップ構成を示した模式図。
【図６】キャリア箔付電解銅箔の断面模式図。
【図７】キャリア箔付電解銅箔の断面模式図。
【図８】キャリア箔付電解銅箔の断面模式図。
【図９】プレス成形時のレイアップ構成を示した模式図。
【図１０】プレス成形時のレイアップ構成を示した模式図。
【図１１】キャリア箔付電解銅箔の断面模式図。
【図１２】キャリア箔付電解銅箔の製造フローを表す模式図。
【符号の説明】
１ａ〜１ｈ　キャリア箔付電解銅箔
２　接合界面層
３　バルク銅層
４　微細銅粒
Ｃ　キャリア箔
ＣＦ　電解銅箔層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrolytic copper foil with a carrier foil, a method for producing the electrolytic copper foil with a carrier foil, and a copper-clad laminate using the same.
[0002]
[Prior art]
BACKGROUND ART Conventionally, an electrolytic copper foil with a carrier foil has been used as a basic material for manufacturing a printed wiring board widely used in the fields of the electric and electronic industries. This electrolytic copper foil with a carrier foil is bonded to a glass-epoxy base, phenol base, or a polymer insulating base such as polyimide by hot press molding to form a copper-clad laminate, which is used for the production of printed wiring boards. It is.
[0003]
This electrolytic copper foil with a carrier foil is thermocompressed with a prepreg cured to a B stage under a high temperature atmosphere under high pressure (hereinafter, this step is referred to as “press molding”) to produce a copper-clad laminate. This prevents wrinkles of the copper foil layer, which are generated at the time, and prevents the copper foil from cracking at the wrinkles, thereby preventing the resin from seeping out from the prepreg. Then, it is easy to form a thin copper foil layer on the surface of the copper-clad laminate.
[0004]
This electrolytic copper foil with a carrier foil can generally be roughly classified into a peelable type and an etchable type. In a nutshell, the peelable type is a type that removes the carrier foil by pressing after press molding, and the etchable type is a type that removes the carrier foil by etching after press molding. It is.
[0005]
Of these, the peelable type has an extremely unstable peel strength value of the carrier foil after press molding, and in extreme cases, the carrier foil cannot be peeled off, and the intended peeling occurs. There was a drawback that strength was hardly obtained. In order to solve this problem, the present inventors have solved the drawbacks of the conventional peelable type electrolytic copper foil with a carrier foil, and stabilized the peel strength of the interface between the carrier foil and the electrolytic copper foil at a low level. On the surface of the carrier foil, a bonding interface layer is formed, copper is electrolytically deposited on the bonding interface layer, and the deposited copper layer is used as an electrolytic copper foil. Japanese Patent Application Laid-Open No. 2000-309898 has disclosed and proposed an electrolytic copper foil with a carrier foil, wherein an organic agent was used for the bonding interface layer.
[0006]
The bonding interface layer of the electrolytic copper foil with a carrier foil proposed by the present inventors is formed by adsorbing an organic agent on the surface of the carrier foil using an aqueous solution containing an organic agent constituting the bonding interface layer. Met. This electrolytic copper foil with a carrier foil is about 180 ° C. when a normal FR-4 prepreg is used, as compared with a conventional peelable type electrolytic copper foil with a carrier foil using a metal material such as chromium for a bonding interface layer. Even after pressing, the carrier foil showed very good performance, and the carrier foil could be peeled off very easily.
[0007]
[Problems to be solved by the invention]
However, in terms of stabilizing the production of an electrolytic copper foil with a carrier foil using an organic agent for the bonding interface layer and stabilizing the quality, sufficient technical establishment has not been achieved.
[0008]
As a result, when a CBTA film is formed using a solution containing CBTA, and the continuous production of an electrolytic copper foil with a carrier foil using the CBTA film as a bonding interface layer is performed, the peel strength of the carrier foil varies. It has become clear that it is easy.
[0009]
When such a phenomenon occurs, the production yield of the electrolytic copper foil with a carrier foil is reduced, and the quality of the product is difficult to be assured. The yield is reduced and the product price is increased. It also affected the quality of the board.
[0010]
Under such circumstances, in the market, although the quality superiority inherent in the electrolytic copper foil with carrier foil using an organic agent for the bonding interface layer has been recognized, there is a demand for products with more stable quality. Is growing.
[0011]
[Patent Document 1]
JP 2000-309898
[0012]
[Means for Solving the Problems]
Therefore, the inventors of the present invention have as a result of intensive studies, as a result, only slightly change the composition of the organic agent used in the production of an electrolytic copper foil with a carrier foil using an organic agent for the bonding interface layer, and to produce the product. They found that even with continuous production, the stability of quality was dramatically increased. Therefore, the bonding interface of the electrolytic copper foil with a carrier foil obtained by this manufacturing method is different from the bonding interface of the conventional electrolytic copper foil with a carrier foil.
[0013]
The present inventors continuously manufactured an electrolytic copper foil with a carrier foil using an organic agent for a bonding interface layer through the steps described below. That is, the electrolytic copper foil 1 with a carrier foil was continuously manufactured by the procedure shown in FIG. In the step shown in FIG. 12A, first, a copper foil having a thickness of 18 μm is used as the carrier foil C, and the surface of the carrier foil C is subjected to pickling treatment to completely remove the attached fat and oil components. Excess surface oxide film was removed. This pickling treatment was carried out using a dilute sulfuric acid solution having a concentration of 100 g / l and a liquid temperature of 30 ° C. for a dipping time of 30 seconds.
[0014]
The carrier foil C having been subjected to the pickling treatment is immersed in an aqueous solution containing CBTA at a concentration of 5 g / l and having a liquid temperature of 40 ° C. and a pH of 5 for 30 seconds, and as shown in FIG. Was formed. Strictly speaking, when such an immersion method is used, the bonding interface layer 2 is formed on both surfaces of the carrier foil C, but only one bonding interface layer 2 is shown in the drawing. ing. At this time, a new CBTA solution was added according to the processing amount of the carrier foil C so that the CBTA concentration in the aqueous solution was always constant.
[0015]
When the formation of the bonding interface layer 2 is completed, the carrier foil C itself on which the bonding interface layer 2 has been formed is cathode-polarized in a copper electrolyte, and bulk copper is placed on the bonding interface layer 2 as shown in FIG. Layer 3 (the bulk copper layer to become a copper foil layer with a nominal thickness of 3 μm) was electrolytically deposited. As the electrolytic solution at this time, a copper sulfate solution having a copper concentration of 55 g / l, a free sulfuric acid concentration of 70 g / l, and a liquid temperature of 40 ° C. was used, and the current density was 5 A / dm. ² For electrolysis.
[0016]
Then, as a surface treatment for improving the adhesion to the base resin, fine copper particles 4 were deposited and adhered on the bulk copper layer 3 to form a roughened surface. The roughened surface is first formed as a step of forming fine copper grains 4 on the bulk copper layer 3, a step of depositing and attaching the fine copper grains 4, and a step of preventing the fine copper grains 4 from falling off. A plating step was performed. In the former step of depositing and attaching the fine copper particles 4, it is a copper sulfate-based solution having a concentration of 7 g / l copper, 100 g / l sulfuric acid, a liquid temperature of 25 ° C., and a current density of 10 A / dm. ² Electrolysis was performed for 10 seconds.
[0017]
As described above, once the fine copper particles 4 are adhered and formed on the bulk copper layer 3, in the cover plating step for preventing the fine copper particles 4 from falling, the falling of the deposited fine copper particles 4 is prevented. In order to do this, copper was uniformly deposited so as to cover the fine copper particles 4 under smooth plating conditions, and the state shown in FIG. 12D was obtained. Here, the copper plating solution is a copper sulfate solution having a concentration of 60 g / l of copper, 150 g / l of sulfuric acid, a liquid temperature of 45 ° C., and a current density of 15 A / dm. ² And electrolysis was performed for 20 seconds.
[0018]
When the above-described roughening treatment was completed, next, a rust prevention treatment was performed. Rust prevention treatment employs inorganic rust prevention, uses a zinc sulfate bath, sulfuric acid concentration 70 g / l, zinc concentration 20 g / l, liquid temperature 40 ° C, current density 15 A / dm ² The zinc was electrodeposited to prevent zinc rust. The illustration of the rust prevention process is omitted in the drawings.
[0019]
When the rust prevention treatment is completed, finally, the substrate is dried in a furnace heated to an ambient temperature of 110 ° C. by an electric heater for 40 seconds, and is passed through a bonding interface layer 2 formed of an organic agent on a 18 μm-thick carrier foil C. Thus, an electrolytic copper foil 1 h with a carrier foil in a state in which a copper foil having a thickness of 3 μm was laminated was obtained. In the above steps, a water washing step is appropriately provided between each step for washing to prevent the solution in the pretreatment step from being brought in.
[0020]
As described above, sampling was performed every 200 m from the start of production of the continuously produced electrolytic copper foil with a carrier foil, and 1 h of the electrolytic copper foil with a carrier foil was subjected to a heat treatment at 180 ° C. for 60 minutes. When the peeling strength of the carrier foil was measured, it was clear from the beginning of the production that the value of the peeling strength varied.
[0021]
According to these results, in the process of continuous production of the electrolytic copper foil with the carrier foil, the CBTA aqueous solution was controlled at a CBTA concentration of 5 g / l, a liquid temperature of 40 ° C., and a pH of 5, but some change occurred in this solution. And should be considered. Therefore, I studied diligently what kind of change was taking place. As a result, there was no problem in controlling the CBTA concentration, the liquid temperature, and the pH in the process, which was good. Therefore, it was considered that it was difficult to solve this problem as long as CBTA was used alone.
[0022]
At this stage, the present inventors consider the principle of forming a bonding interface layer using CBTA, and the CBTA is not simply adsorbed on the carrier foil, which is a metal, but the surface of the carrier foil is slightly dissolved. Then, it was considered that the eluted metal ion and CBTA formed a complex near the surface of the carrier foil, and the complex was deposited on the surface of the carrier foil, thereby forming a bonding interface layer. Therefore, by allowing the second organic agent to coexist, the elution rate of metal ions from the surface of the carrier foil is promoted to facilitate the formation of the complex, or the formed complex is more uniformly and densely deposited on the metal surface. It is considered to have an effect of having a structure such as depositing at the surface of the metal or a structure of depositing more uniformly and densely on the metal surface when forming the bonding interface layer with the CBTA complex. is there. As a result, it is considered that a bonding interface layer having excellent heat resistance can be formed. Therefore, the inventors have found such a second organic agent. As a result, it was found that coexistence of a methylbenzotriazole (hereinafter, referred to as “MBTA”) polymer was very effective.
[0023]
That is, MBTA is used as a raw material for producing CBTA by reacting with water as shown in Chemical formula 1. The MBTA polymer is a polymer such as a dimer, a trimer or the like formed by a polymerization reaction of the MBTA itself. The present inventors added the MBTA polymer to the CBTA aqueous solution at the beginning of the production of the above-described electrolytic copper foil with a carrier foil, and produced an electrolytic copper foil with a carrier foil. It was found that the variation in the values was dramatically reduced.
[0024]
Embedded image

[0025]
The polymer of MBTA (hereinafter and simply referred to as “MBTA polymer”) is a dimer which undergoes a polymerization reaction as a side reaction when a reaction for producing CBTA from MBTA is performed. CBTA may be formed as a trimer or the like, and the CBTA and the MBTA polymer can be separated by solvent extraction from a state mixed with CBTA. Formula 2 shows an example of an MBTA polymer that can be considered as a dimer. As for this MBTA polymer, up to a heptamer has been confirmed within the measurement limit of the analyzer used for the study by the present inventors. If the amount of the MBTA polymer in the CBTA solution is reduced, the peel strength of the carrier foil of the electrolytic copper foil with the carrier foil after heating becomes unstable. Therefore, the present inventors control the abundance of the MBTA polymer in the CBTA, form a bonding interface layer of the electrolytic copper foil with a carrier foil, and produce an electrolytic copper foil with a carrier foil. It was thought that the value of the peeling strength would not fluctuate, the product would have very stable quality, and the production yield would be improved.
[0026]
Embedded image

[0027]
Based on the above research results, the claims claim that `` on one side of the carrier foil, provided with a bonding interface layer, in the electrolytic copper foil with a carrier foil provided with an electrolytic copper foil layer on the bonding interface layer, The bonding interface layer is formed using a solution containing CBTA and MBTA polymer, and the MBTA polymer contained in the bonding interface layer is 2.0 wt% to 60.0 wt%. And an electrolytic copper foil with a carrier foil. " FIG. 1 schematically shows a cross section of the electrolytic copper foil 1a with a carrier foil.
[0028]
As is clear from FIG. 1, the electrolytic copper foil with carrier foil 1a is a product in which the carrier foil C and the electrolytic copper foil CF are in a state of being bonded together. Then, the electrolytic copper foil 1a with a carrier foil is obtained by laminating an electrolytic copper foil layer CF on a resin substrate in a state where the carrier foil C is attached, and then peeling the carrier foil C to obtain a copper-clad laminate. Used. Above and below, the electrolytic copper foil and the electrolytic copper foil layer, the carrier foil and the carrier foil layer, the bonding interface and the bonding interface layer indicate the same portions, respectively, and are appropriately used according to the description.
[0029]
The electrolytic copper foil with carrier foil 1a according to the present invention is characterized in that a mixed composition containing CBTA and MBTA polymer is used for a bonding interface 2 located between the carrier foil C and the electrolytic copper foil CF. Have. By forming the bonding interface layer 2 using a mixture of the CBTA and the MBTA polymer, a continuous production of the electrolytic copper foil with a carrier foil can be achieved as compared with a case where CBTA is used alone for forming the bonding interface layer 2. In this case, the product quality can be stabilized, and the product yield is dramatically improved. Further, when the MBTA polymer is used alone without adopting a mixed composition with CBTA, the carrier foil C cannot be peeled off from the electrolytic copper foil layer CF after heating. Further, the electrolytic copper foil with a carrier foil provided with the bonding interface layer 2 formed using a solution containing CBTA and MBTA polymer is obtained by hot press molding at a completely different level from the conventional electrolytic copper foil with a carrier foil. Another feature is that the stability of the peel strength value of the carrier foil after heating is significantly improved.
[0030]
Then, in the course of the study of the present inventors, the following has been found. When the bonding interface layer of the electrolytic copper foil with a carrier foil is formed using a solution containing CBTA and MBTA polymer, the carrier foil cannot be peeled off after heating if CBTA does not exist at all. If the amount of the MBTA polymer is too low, the stability of the peeling strength of the carrier foil is also lacked. Therefore, as a result of intensive studies by the present inventors, it has been found that when the MBTA polymer contained in the bonding interface layer is in the range of 2.0 wt% to 60.0 wt%, extremely stable quality can be exhibited. I understand.
[0031]
That is, by forming the bonding interface layer using a solution containing CBTA and MBTA polymer, the peel strength of the carrier foil is reduced to a level at which the carrier foil can be easily peeled off by a human hand. It is possible to control stably. In addition, the electrolytic copper foil with a carrier foil provided with a bonding interface layer using only CBTA is vulnerable to high-temperature heating, and after being heated to more than 200 ° C., the peeling strength of the carrier foil increases, and It can also improve the situation where peeling by work is difficult. That is, when a solution containing CBTA and MBTA polymer is used to form the bonding interface layer, the interdiffusion between the carrier foil and the electrolytic copper foil is extremely effective even when subjected to press forming at a high temperature range of about 230 ° C. Although the bonding strength between the carrier foil and the electrolytic copper foil is slightly increased, it can be maintained at a level that can be used sufficiently as a peelable type electrolytic copper foil with a carrier foil until after press molding. is there.
[0032]
Here, as an example, when a bonding interface layer is formed on a 35 μm carrier foil using a solution containing CBTA and MBTA polymer and a 5 μm electrolytic copper foil layer is formed, the bonding is performed. An example of the result of examining the peel strength at the interface is 15.0 gf / cm before heating, and 15.2 gf / cm even after heating at 230 ° C. for 1 hour, which is easily obtained as a peelable type. The property that it can be peeled off by hand has been maintained.
[0033]
The method for forming the bonding interface layer on the carrier foil using the solution containing the CBTA and the MBTA polymer described above will be described below. The bonding interface layer is formed on the carrier foil by dissolving the CBTA and the MBTA polymer in a solvent and immersing the carrier foil in the solvent, or showering the surface on which the bonding interface layer is to be formed, It can be carried out using a spraying method, a dropping method, an electrodeposition method, or the like, and there is no need to employ a particularly limited method. At this time, the CBTA concentration in the solvent is preferably 50 ppm to 5000 ppm, and the concentration of the MBTA polymer is preferably in the range of 2 ppm to the saturation solubility. Within this concentration range, the content of the MBTA polymer in the formed bonding interface layer is stably in the range of 2.0 wt% to 60.0 wt%. And it is desirable to adopt the range of 20-60 degreeC about a liquid temperature. If the liquid temperature is too low, the adsorption rate becomes slow, and if the liquid temperature is too high, the CBTA and MBTA polymers tend to be easily decomposed.
[0034]
Further, as described in the claims, the formation of the bonding interface layer using a solution containing CBTA and the MBTA polymer can be repeated a plurality of times as described above. Thereby, it is possible to control the thickness of the bonding interface layer with higher accuracy.
[0035]
The role played by the MBTA polymer in the solution in which the CBTA and the MBTA polymer coexist is considered as follows. As a result of intensive studies, the bonding interface layer formed using a solution in which CBTA and MBTA polymer coexist is thinner, more uniform, and has a higher specific gravity than the bonding interface layer formed using only conventional CBTA. It has come to be considered a dense coating. That is, the natural potential measured by immersing the copper foil used as the carrier foil in the solution containing the MBTA polymer was compared with the natural potential measured by immersing the copper foil used as the carrier foil in the solution containing CBTA. Has higher spontaneous potential. That is, it is considered that the copper component of the carrier foil dissolves quickly, and tends to easily form a complex with copper. For example, as the amount of the MBTA polymer in the solution containing CBTA is gradually increased, the natural potential also increases. Therefore, by observing the natural potential, it is possible to monitor the content of the MBTA polymer in the solution in which the CBTA and the MBTA polymer coexist in the production process, and it is possible to use this natural potential as a control index. It is possible.
[0036]
According to the principle of forming the bonding interface layer, when the bonding interface layer is formed with a solution containing CBTA and an MBTA polymer on a metal carrier foil, the surface of the carrier foil is slightly dissolved and eluted metal ions, It is considered that the CBTA and MBTA polymers form a complex near the surface of the carrier foil, and the complex is deposited on the surface of the carrier foil, thereby forming a bonding interface layer. Therefore, from the above-mentioned fact regarding the spontaneous potential, it is considered that the MBTA polymer in the solution acts as a promoter for dissolving the metal on the surface of the carrier foil. As a result, the metal ions generated by the dissolution of the carrier foil, the CBTA and the MBTA polymer easily form a complex, and the rate at which the CBTA complex and the MBTA complex are simultaneously deposited on the carrier foil surface is increased. Or, it is considered that they are more uniformly dispersed and deposited at a higher density than in the case of CBTA alone. As a result, it is possible to form a bonding interface layer as a high-density organic film with a uniform thickness even though it is thin compared to the case of using CBTA alone. Moreover, since the MBTA polymer has a higher melting point and decomposition temperature than CBTA, it becomes a more stable bonding interface layer.
[0037]
In the electrolytic copper foil with a carrier foil according to the present invention, the thickness of the formed bonding interface layer is very important. From this, the claims clarify that the thickness of the bonding interface layer formed using a solution containing CBTA and MBTA polymer is preferably in the range of 0.5 nm to 1 μm.
[0038]
In the thickness range specified here, it is possible to secure an appropriate peel strength of the carrier foil even after high-temperature press molding, and it is possible to perform stable electrolytic deposition of copper constituting the electrolytic copper foil layer. That is, if the thickness of the bonding interface layer is less than the lower limit of 0.5 nm, the peel strength after press molding becomes unstable. If it exceeds the upper limit of 1 μm, the energized state becomes unstable when attempting to form an electrolytic copper foil layer directly on the bonding interface layer, the copper deposition state becomes unstable, and the electrolytic layer having a uniform thickness is formed. This makes it difficult to form a copper foil layer. Even if copper is deposited over a long period of time, sufficient adhesion between the bulk copper layer and the bonding interface layer cannot be obtained, and the minimum peel strength required for safe press molding can be obtained. It cannot be obtained. Then, when the thickness of the bonding interface layer is further increased, it becomes a state in which electricity cannot be completely supplied. Since the thickness of the bonding interface layer is extremely thin, on the order of nm to μm, it is desirable to confirm the measurement using a transmission electron microscope (TEM).
[0039]
The “appropriate peel strength” in the present specification is considered to be a value measured in accordance with JIS-C-6481 in a range of 5 to 100 gf / cm. This is based on the experience of using the conventional peelable type electrolytic copper foil with a carrier foil, and the peel strength (peel strength) at the interface between the carrier foil and the electrolytic copper foil, which is considered to be appropriate obtained through experience, This is a range in which an ideal demand value of a user of the electrolytic copper foil with a carrier foil is added. The lower the peel strength at the interface between the carrier foil and the electrolytic copper foil, the easier the peeling operation.
[0040]
However, when the peeling strength is less than 5 gf / cm, the carrier foil and the electrolytic copper foil are spontaneously formed when the electrolytic copper foil with the carrier foil is manufactured and wound into a roll, or when the copper-clad laminate is pressed. Partial peeling causes blistering, misalignment and other defects. On the other hand, when the peeling strength exceeds 100 gf / cm, the work load when an operator peels off the carrier foil by hand increases sharply.
[0041]
The material of the carrier foil used here is not particularly limited. It is used as a concept including everything that can be used as a carrier, such as an aluminum foil, a copper foil, and a resin film whose surface is metal-coated as a carrier foil. However, a metal component which forms a complex with at least the CBTA and MBTA polymers and which facilitates the formation of a bonding interface layer must be present on the surface. Also, there is no particular limitation on the thickness of the carrier foil. From an industrial point of view, the concept of a foil is generally referred to as a foil having a thickness of 200 μm or less, and it is sufficient to use this concept.
[0042]
The electro-deposited copper foil layer includes not only an electro-deposited copper foil called an ultra-thin copper foil of 12 μm or less, but also a case where the thickness is more than 12 μm. Conventional electrolytic copper foil with a carrier foil is used exclusively for the purpose of providing an ultra-thin copper foil, and those having an electrolytic copper foil layer of 12 μm or more, such as the electrolytic copper foil with a carrier foil according to the present invention, are commercially available. Had not been supplied to. The advantage of the electrolytic copper foil with a carrier foil having such a thick electrolytic copper foil layer is that an organic bonding interface layer using a solution containing CBTA and MBTA polymer is used, so that the carrier foil layer and the electrolytic This is because a new method of using an electrolytic copper foil with a carrier foil, which will be described later, becomes possible by the stable and easy peeling of the copper foil layer after high-temperature pressing.
[0043]
Here, it should be noted for confirmation that the electrolytic copper foil 1a with a carrier foil shown in FIG. 1 is not used for copper-clad laminates and printed wiring boards, except for special uses. The fine copper particles 4 are uniformly adhered to the outer surface of the copper foil layer CF for use. These are fine copper particles similar to those formed on the surface of the general electrolytic copper foil that is bonded to the resin substrate. This is to prevent peeling.
[0044]
In another aspect, the invention relates to an electrolytic copper foil with a carrier foil having a bonding interface layer on both surfaces of a carrier foil and an electrolytic copper foil layer on each of the bonding interface layers. The layer is formed using a solution containing CBTA and MBTA polymer, and the MBTA polymer contained in the bonding interface layer is 2.0 wt% to 60.0 wt%. And an electrolytic copper foil with a carrier foil. " FIG. 2 schematically shows a cross section of the electrolytic copper foil 1b with a carrier foil. The above-described electrolytic copper foil with carrier foil 1a has a shape in which electrolytic copper foil CF is bonded to one surface of carrier foil C as shown in FIG. Has a shape as if the electrolytic copper foil CF was bonded to both sides of the carrier foil C, as is apparent from the schematic sectional view of FIG.
[0045]
For example, if the electrolytic copper foil 1a with a carrier foil shown in FIG. 1 is laid up and pressed as shown in FIG. 4, the end plate M of the intermediate layer can be omitted. However, by using the electrolytic copper foil 1b with a carrier foil, it is possible to more easily omit the mirror plate at the time of manufacturing the copper-clad laminate, and to completely prevent foreign matter from entering the copper foil surface at the time of press molding. Can be prevented. As shown in FIG. 3, the production of a normal double-sided copper-clad laminate generally involves a mirror plate M having a heat-resistant material such as stainless steel mirror-finished, a copper foil CF, one or more sheets between upper and lower press plates P. The order of the prepreg PP, the copper foil CF, and the end plate M is repeatedly laminated (commonly referred to as lay-up), and the press plate P is heated at a high temperature, and the resin component of the prepreg PP is melted by being sandwiched. The CF and the prepreg PP are bonded at high temperature under pressure.
[0046]
At this time, when the above-described double-sided electrolytic copper foil with carrier foil 1b is used, as shown in FIG. 5, the lowermost layer and the uppermost layer OF in the laid-up state are provided with a normal electrolytic copper foil or a single-sided electrolytic copper with carrier foil. By using the foil and the other intermediate layer located on the intermediate layer as the double-sided electrolytic copper foil 1b with a carrier foil, it is possible to omit all the end plates M located on the intermediate layer portion, and at the time of disassembly after press molding, It only has to be peeled off from the bonding interface 2 between the carrier foil C and the electrolytic copper foil layer CF.
[0047]
The fact that the end plate M of the intermediate layer becomes unnecessary means that the number of steps of the copper foil CF and the prepreg PP to be accommodated between the daylights of the press plate P can be increased by the thickness of the omitted end plate M, The number of copper-clad laminates manufactured by one press can be increased. In addition, heat conductivity is improved, and productivity can be improved. Normally, the thickness of the head plate M is 0.8 mm to 3.0 mm. Considering that the thickness of the copper foil CF is 3 to 50 μm and the thickness of one prepreg PP is 30 to 180 μm, it is extremely high. It can be expected that a large productivity improvement effect will be obtained.
[0048]
In general, the electrolytic copper foil layer CF is subjected to (1) a bulk copper layer 3 for forming a conductive circuit, and (2) a roughening treatment for improving the adhesion of the copper-clad laminate to the base resin. Layer (fine copper particles 4), but the present invention has a concept including an electrolytic copper foil layer composed only of the roughening treatment 4 of (2). Therefore, the “electrolytic copper foil layer” of the above-described two types of electrolytic copper foils with a carrier foil is composed of only the fine copper particles 4 deposited and adhered by the electrolytic method.
[0049]
FIGS. 6 and 7 schematically show the cross-sectional forms of the carrier-coated electrolytic copper foils 1c and 1d in which the electrolytic copper foil layer is composed of the fine copper particles 4 only. When manufacturing a copper-clad laminate using these carrier foil surface-electrolyzed copper foils, only the fine copper particles 4 are bonded to the prepreg, and there is no bulk copper layer. However, since the bulk copper layer is indispensable for forming the conductor circuit, in the printed wiring board manufacturing process, the printed wiring board manufacturer removes the carrier foil C and adjusts the timing and optional copper according to the purpose. By the plating method, a bulk copper layer having a predetermined thickness can be formed on the fine copper particles 4. For example, a bulk copper layer can be formed on the surface of the fine copper particles 4 as the electrolytic copper foil layer by a panel plating method, or can be performed by an electroless copper plating method. According to such a method, the thickness of the bulk copper layer can be arbitrarily adjusted according to the type of the circuit to be formed, and the thickness of the bulk copper layer can be adjusted to an appropriate value in accordance with the desired circuit width. It is. Therefore, such a method of manufacturing a printed wiring board is more effective as the circuit to be formed becomes finer, and the density of the circuit of the printed wiring board can be easily increased.
[0050]
Here, the advantage of using the electrolytic copper foil for the carrier foil C will be described. In order to make this description easier to understand, a normal electrolytic copper foil used as the carrier foil C will be briefly described here. Normally, an electrolytic copper foil is manufactured through an electrolytic process and a surface treatment process, and is mainly used as a basic material for manufacturing a printed wiring board used in the fields of the electric and electronic industries.
[0051]
It is preferable that the electrolytic copper foil used for the carrier foil C has a thickness of 12 μm to 210 μm. By using the electrolytic copper foil having such a thickness as the carrier foil, various advantageous effects not obtained in the conventional electrolytic copper foil with a carrier foil can be obtained. Here, the thickness of the electrolytic copper foil used as the carrier foil was set to 12 μm to 210 μm, in order to play a role as a reinforcing material for preventing the occurrence of wrinkles of an ultra-thin copper foil of 9 μm or less as a carrier foil, This is because a thickness of at least about 12 μm is required, and a thickness of 210 μm or more, which is the upper limit, exceeds the concept of a foil and is rather close to a copper plate, and it is difficult to take up and form a roll.
[0052]
Advantageous effects of using an electrolytic copper foil as the carrier foil C are as follows. When a foil obtained by a rolling method is used as a carrier foil, as represented by a rolled aluminum material, it is inevitable that rolling oil adheres to the foil, and an oil component is taken into consideration in order to prevent oxidation. May be applied. When these are used as a carrier foil, they become obstacles for depositing copper on the carrier, and therefore, it is necessary to remove oil in the process. If it is an electrolytic copper foil, it cannot be unavoidably adhered to oil from its manufacturing method, and even if an oxide film is formed, it can be easily pickled and removed. Process control can be facilitated.
[0053]
Further, when an electrolytic copper foil is used as the carrier foil C of the electrolytic copper foils 1a to 1d with a carrier foil, the carrier foil C and the electrolytic copper foil CF bonded to the carrier foil C have physical properties as components. It can be considered that they are the same, and both etching processes can be performed with the same type of etching solution. Therefore, after processing into a copper-clad laminate, forming an etching resist layer on the carrier foil C without peeling off the carrier foil C, etching the printed wiring circuit, and then peeling off the carrier foil C. Is also possible. By doing so, the surface of the copper foil circuit is protected from contamination and adhesion of foreign matter until the etching process is completed, and it is possible to greatly improve the reliability of operations such as a plating process performed thereafter.
[0054]
Further, the purity of the electrolytic copper foil used as the carrier foil C is 99.99% or more. Then, the electrolytic copper foil with carrier foil 1a to 1d according to the present invention does not include another metal element as an impurity in the bonding interface layer 2. Therefore, the carrier foil after being peeled can be easily recycled, and does not unnecessarily generate industrial waste from the viewpoint of environmental protection. For example, the carrier foil can be collected and redissolved to obtain a copper ingot, or it can be dissolved again with sulfuric acid as a raw material for producing an electrolytic copper foil to obtain a copper sulfate solution.
[0055]
As the electrolytic copper foil as the carrier foil C at this time, either an untreated foil that has not been subjected to a roughening treatment or a surface-treated foil that has been subjected to a roughening treatment may be used. There is no difference in the roughness of the glossy surface between the untreated foil and the surface-treated foil, and there is no difference in the copper foil layer itself if a copper foil layer is formed on the glossy surface. FIG. 8A is a schematic cross-sectional view when an untreated foil is used as a carrier foil, and FIG. 8B is a schematic cross-sectional view when a surface-treated foil is used as a carrier foil. In these electrolytic copper foils with carrier foils 1e and 1f, the method of using a copper-clad laminate obtained by using an untreated foil or a surface-treated foil differs depending on whether the carrier foil C is an untreated foil or a surface-treated foil. Come.
[0056]
Here, a description will be given of a usage method that can be employed in the production of a copper-clad laminate of the electrolytic copper foils 1e and 1f with a carrier foil when an untreated foil is used as the carrier foil and when a surface-treated foil is used. First, a case where an untreated foil is used as the carrier foil C will be described as a method of manufacturing the first copper-clad laminate. The electrolytic copper foil with carrier foil 1e in such a case has a cross-sectional shape shown in FIG. As can be seen from this figure, the surface that can be bonded to the prepreg is only the surface of the electrolytic copper foil layer CF to which the fine copper particles 4 are attached as a roughening treatment.
[0057]
Therefore, as shown in FIG. 3, the lay-up is performed, and the electrolytic copper foil 1e with the carrier foil and the prepreg PP (in the case where the outer copper foil layer of the It is possible to obtain a copper-clad laminate by press molding using a prepreg and an inner layer substrate) and a mirror plate M. In addition, by using the electrolytic copper foil with the carrier foil, it is possible to perform press molding without the inner layer end plate. That is, as shown in FIG. 9, the end plate M is disposed only on the outermost layer that directly contacts the press plate P, and the electrolytic copper foil 1 e with carrier foil and the prepreg PP are placed between the two end plates M. They are laid up in layers.
[0058]
One sheet of electrolytic copper foil with carrier foil or ordinary copper foil OF is arranged on the uppermost layer and the lowermost layer when laid up. Then, as shown in the enlarged view of FIG. 9, the copper foils located in the other inner layers when laid up lie on the back of the carrier foil C and the carrier foil C of the two electroplated copper foils 1e with carrier foil. At the same time, the electrolytic copper foil layer CF is arranged so that the surface subjected to the surface roughening treatment is in contact with the prepreg PP. Then, at the time of the disassembling operation after the completion of the press molding, the carrier foil C is peeled off from the bonding interface layer 2 so that the outer copper foil layer of the double-sided board or the multilayer board can be formed.
[0059]
On the other hand, as a method of manufacturing the second copper-clad laminate, a method of using an electrolytic copper foil with a carrier foil 1f using a surface-treated foil for the carrier foil C in the production of a copper-clad laminate will be described. In such a case, the electrolytic copper foil with a carrier foil 1f has a sectional shape shown in FIG. 8B. As can be seen from this figure, the surface that can be bonded to the prepreg PP is the surface to which the fine copper particles 4 are adhered by the roughening treatment, so that not only the electrolytic copper foil CF side but also the carrier foil C It will also be on the side.
[0060]
That is, the electrodeposited copper foil with carrier foil 1f is finished in a shape as if the glossy surfaces of the two surface-treated normal electrolytic copper foils were bonded to each other. Therefore, the carrier foil can also be used as the electrolytic copper foil of the copper clad laminate. Since it has such a structure, it can be used as follows.
[0061]
The copper clad laminate is obtained by press-forming using the electrolytic copper foil with carrier foil 1f, the prepreg PP (prepreg and inner layer substrate when the outer copper foil layer of the multilayer substrate is formed) and the end plate M. By using the electrolytic copper foil 1f with a carrier foil, press molding without the inner-layer end plate becomes possible. That is, as shown in FIG. 10, the end plate M is arranged only on the outermost layer which is in direct contact with the press plate P, and between the two end plates M, the electrolytic copper foil with carrier foil 1 f and the prepreg PP are placed. Lay up.
[0062]
One sheet of electrolytic copper foil with carrier foil or ordinary copper foil OF is arranged on the uppermost layer and the lowermost layer when laid up. Then, as shown in the enlarged view of FIG. 10, the prepreg PP is arranged on both surfaces of the electrolytic copper foil with carrier foil 1 f as shown in the enlarged view of FIG. Press molding in this way enables molding without using the end plate M. Then, at the time of the disassembling operation after the completion of the press molding, the outer copper foil layer of the double-sided substrate or the multilayer substrate can be formed by peeling off the bonding interface layer 2 of the electrolytic copper foil with carrier foil 1f. According to this method, there is also an advantage that no scrap is generated at all.
[0063]
The above-described method of using the electrolytic copper foil with a carrier foil 1a to 1f according to the present invention can maintain the peel strength of the bonding interface layer 2 of the electrolytic copper foil with a carrier foil low and stabilize it. This is the first press forming method that can be realized. Therefore, the useful effect provided by the electrolytic copper foil with a carrier foil 1a to 1f according to the present invention has a very large effect on the printed wiring board industry, and greatly contributes to a reduction in the manufacturing cost of the copper-clad laminate. It can be said that.
[0064]
At this time, if the thickness of the electrolytic copper foil layer deposited and formed on the glossy surface of the electrolytic copper foil serving as the carrier foil C is extremely thin, a copper-clad laminate to which the ultra-thin copper foil is attached is used. When a circuit having a pitch of about 50 μm is formed, the etching time of the copper foil portion can be extremely shortened, and a fine circuit having an extremely good aspect ratio can be formed.
[0065]
Then, on the roughened surface of the electrolytic copper foil used as the carrier foil C, a bonding interface layer 2 is formed using a solution containing CBTA and MBTA polymer, and copper is electrolytically deposited on the bonding interface layer 2. Alternatively, an electrolytic copper foil with a carrier foil using the deposited copper layer as an electrolytic copper foil can be used. The untreated foil described above is used as the carrier foil used here. FIG. 11 shows a schematic sectional view of 1 g of the electrolytic copper foil with a carrier foil. As can be seen from FIG. 11, the ultra-thin electrolytic copper foil layer is formed along the uneven shape of the rough surface of the electrolytic copper foil as the carrier foil C. That is, the electrolytic copper foil layer CF has a wavy shape.
[0066]
Therefore, when a copper-clad laminate is manufactured using 1 g of the electrolytic copper foil with a carrier foil, the copper-clad laminate is press-formed while maintaining the wavy shape as it is. This shape is very useful in forming a fine circuit. In addition, since the lay-up method at the time of manufacturing a copper-clad laminate using 1 g of the electrolytic copper foil with a carrier foil is the same as the method described in FIG. 3, duplicate descriptions are omitted. And
[0067]
The factors required for an electrolytic copper foil required for forming a fine circuit can be roughly understood as follows: (1) ensuring good adhesion to an etching resist, (2) securing a good exposure state, and (3). It is considered to be physical properties such as fast etching time, (4) other peeling strength (including chemical resistance, etc.). Most of the characteristics mentioned here will be good, but among them, the corrugated electrolytic copper foil mainly contributes to the good adhesion with the etching resist and the good exposure state Is what you do.
[0068]
By using an electrolytic copper foil having a wavy shape for a copper-clad laminate, the adhesion between various resists and the surface of the electrolytic copper foil is improved. For example, if the adhesion to the etching resist is improved, the intrusion of the etching solution into the bonding interface between the copper foil and the etching resist can be prevented, and a circuit cross section having a good aspect ratio can be formed. The formation of a fine circuit in consideration of the above becomes easy. In addition, by having a wavy surface shape, gloss is almost matte compared to a normal flat glossy surface. As a result, it is possible to suppress extra scattering of exposure light at the time of exposure to the etching resist of the etching pattern, and it is possible to reduce the influence of so-called exposure blur at the edge of the circuit pattern. . Further, the laser drilling workability can be improved.
[0069]
Also, when copper plating is applied to a copper-clad laminate with an electrolytic copper foil layer having a wavy shape, the results show that the peel strength at the interface between the copper foil surface and the plating layer is improved. I have. Therefore, it can be said that the use of the electrolytic copper foil with a carrier foil improves the adhesion of the plating layer.
[0070]
As a result, it is possible to prevent the aspect ratio of the circuit cross section from deteriorating when a fine circuit having a pitch of 50 μm is formed using a normal electrolytic copper foil, and to form a circuit having an ideal aspect ratio. In addition, since exposure blur of the etching resist is small, the linear stability of the edge portion of the formed circuit is improved, and the formation of a fine circuit can be facilitated. The improved linear stability of the edge of the formed circuit means that the upper and lower edges of the etched circuit have excellent linearity, and the land used for mounting components on the printed wiring board. It means that the edge portion of the entire formed circuit such as the edge shape of the circular circuit portion is smooth. In other words, since the circuit has excellent linear stability, it suppresses copper migration that may occur when used as a printed wiring board, and eliminates discharge phenomena from protrusions at the circuit edge when using a high-frequency signal. It can be said that this is also possible.
[0071]
The method for using the electrolytic copper foil with carrier foil 1a to 1g according to the present invention described above maintains the peel strength of the bonding interface layer 2 of the electrolytic copper foil with carrier foil 1a to 1g low as described above, In addition, since it can be stabilized, it is a press forming method that can be realized for the first time.
[0072]
And as a manufacturing method of the electrolytic copper foil with a carrier foil, as described above, the formation of the bonding interface on the surface of the carrier foil is performed by using a solution containing 50 ppm to 5000 ppm of CBTA and 2 ppm to saturated solubility of MBTA polymer. The organic film is characterized by being formed as an organic film by absorbing the organic agent. The manufacturing flow of the electrolytic copper foil with a carrier foil according to the present invention is the same as the flow itself at the beginning of the manufacturing method performed to confirm the problem of manufacturing the electrolytic copper foil with a carrier foil having a bonding interface layer using only CBTA. Therefore, only the concept necessary for each step will be described with reference to FIG.
[0073]
The first pickling treatment of the carrier foil is performed for the purpose of degreasing treatment for completely removing the fat component attached to the carrier foil and removing the surface oxide film when a metal foil is used. By passing the carrier foil through the acid solution, the carrier foil is cleaned, and uniform adhesion and electrodeposition in the following steps are ensured. Various solutions such as a hydrochloric acid-based solution, a sulfuric acid-based solution, and a sulfuric acid-hydrogen peroxide-based solution can be used for this pickling treatment, and there is no particular limitation. Then, it is sufficient to adjust the solution concentration, the solution temperature, and the like according to the characteristics of the production line.
[0074]
The formation of the bonding interface layer performed after the pickling treatment is performed in the step of performing the processing of forming the bonding interface layer on one or both surfaces of the carrier foil using the above-described mixed solution of a solution containing CBTA and the MBTA polymer. That is. This bonding interface layer is formed by (1) a method in which a carrier foil is immersed in a solution containing CBTA and MBTA polymer, and (2) a solution containing CBTA and MBTA polymer is formed into a bonding interface layer. (3) a method of showering or dripping on the surface of the carrier foil to be bonded, and (3) a method of electrodepositing the surface of the carrier foil forming the bonding interface layer using a solution containing CBTA and MBTA polymer. Etc. can be adopted.
[0075]
When the formation of the bonding interface layer is completed, subsequently, the electrolytic copper foil layer is formed on the bonding interface layer. First, a bulk copper layer is formed except for an electrolytic copper foil with a carrier foil in which the electrolytic copper foil layer is composed of only fine copper particles. The copper electrolytic solution used for forming the bulk copper layer is a solution that can be used as a copper ion supply source, such as a copper sulfate solution or a copper pyrophosphate solution, and is not particularly limited. For example, in the case of a copper sulfate solution, the concentration is 30 to 100 g / l of copper, 50 to 200 g / l of sulfuric acid, the liquid temperature is 30 to 80 ° C., and the current density is 1 to 100 A / dm. ² In the case of a copper pyrophosphate-based solution, the concentration is 10 to 50 g / l of copper, 100 to 700 g / l of potassium pyrophosphate, a liquid temperature of 30 to 60 ° C., a pH of 8 to 12, and a current density of 1 to 10 A / dm. ² And so on. Here, the carrier foil on which the bonding interface layer is formed is immersed in the solution, the anode electrode is arranged in parallel with the surface of the carrier foil on which the bonding interface layer is formed, and the carrier foil itself is cathodically polarized, whereby the bulk is obtained. The copper component forming the copper layer is uniformly and smoothly deposited on the bonding interface layer.
[0076]
Then, when the formation of the bulk copper layer is completed, next, fine copper grains are formed on the surface of the bulk copper layer. In the case of attaching fine copper particles, it is common practice to deposit and attach the fine copper particles on the bulk copper layer, and then to perform cover plating to prevent the fine copper particles from falling off. When the electrolytic copper foil layer is composed of only fine copper grains, the formation of the electrolytic copper foil layer starts from this step, omitting the formation of the bulk copper layer.
[0077]
In order to deposit fine copper particles on the bulk copper layer, the same type of copper electrolyte as used in the above-described bulk copper forming tank is used. However, the electrolysis conditions used in the bulk copper forming tank are smooth plating conditions, whereas the electrolysis conditions here are burnt plating conditions. Therefore, the concentration of the solution used in the step of depositing and depositing fine copper particles on the bulk copper layer is generally lower than the concentration of the solution used in the formation layer of the bulk copper so as to easily create burn plating conditions. I have. The burn plating conditions are not particularly limited, and are determined in consideration of the characteristics of the production line. For example, if a copper sulfate-based solution is used, the concentration is 5 to 20 g / l of copper, 50 to 200 g / l of sulfuric acid, other additives (α-naphthoquinoline, dextrin, glue, thiourea, etc.), Temperature 15-40 ° C, current density 10-50A / dm ² And so on.
[0078]
Then, in the over-plating for preventing the falling of the fine copper particles, copper is uniformly deposited so as to cover the fine copper particles under the smooth plating condition in order to prevent the falling of the deposited fine copper particles. is there. Therefore, here, the same solution as that used in the above-described bulk copper forming tank can be used as a supply source of copper ions. The conditions for the smooth plating are not particularly limited, and are determined in consideration of the characteristics of the production line. For example, when a copper sulfate solution is used, the concentration is 50 to 80 g / l of copper, 50 to 150 g / l of sulfuric acid, the liquid temperature is 40 to 50 ° C., and the current density is 10 to 50 A / dm. ² And so on.
[0079]
When the basic structure of the electrolytic copper foil with a carrier foil is completed as described above, a rustproofing process is usually performed next. This rust prevention treatment is for preventing the surface of the electrolytic copper foil layer from being oxidized and corroded so as not to hinder the production process of the copper-clad laminate and the printed wiring board. As the rust preventive treatment, there is no problem whether organic rust preventive using benzotriazole, imidazole or the like or inorganic rust preventive using zinc, chromate, zinc alloy or the like is used. Rust prevention may be selected according to the intended use of the electrolytic copper foil with carrier foil. In the case of organic rust prevention, techniques such as dip coating, showering coating, and electrodeposition of an organic rust inhibitor can be employed.
[0080]
In the case of inorganic rust prevention, it is possible to use a method of depositing a rust-preventive element on the surface of an electrolytic copper foil layer by electrolysis, or a so-called substitution deposition method. For example, as the zinc rust prevention treatment, a zinc pyrophosphate plating bath, a zinc cyanide plating bath, a zinc sulfate plating bath, or the like can be used. For example, in the case of a zinc pyrophosphate plating bath, the concentration is 5 to 30 g / l of zinc, 50 to 500 g / l of potassium pyrophosphate, the liquid temperature is 20 to 50 ° C, the pH is 9 to 12, and the current density is 0.3 to 10 A / dm. ² And so on.
[0081]
When the rust prevention treatment is completed, the resultant is washed with water and dried to obtain a completed electrolytic copper foil with a carrier foil. In addition, since the operation of providing a means that can be appropriately washed with water between each process and preventing the solution of the previous process from being carried into the subsequent process is natural, the description of the manufacturing flow is dared. Not specified.
[0082]
Through the steps described above, the production of the electrolytic copper foil with a carrier foil according to the present invention is performed. Then, these electrolytic copper foils with a carrier foil are processed into a copper-clad laminate mainly used as a base material for manufacturing a printed wiring board. The term “copper-clad laminate” used herein includes the concept of all the layer configurations of a single-sided board, a double-sided board, and a multilayer board. In addition, the base material is not limited to a rigid board, but may be a special board such as a so-called TAB or COB. And all of a flexible substrate, a hybrid substrate, and the like.
[0083]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an electrolytic copper foil with a carrier foil was manufactured using the method for manufacturing an electrolytic copper foil with a carrier foil according to the present invention. Then, after press-molding the copper-clad laminate, in order to confirm the peel strength and stability of the carrier foil from the electrolytic copper foil layer, the obtained electrolytic copper foil with a carrier foil is subjected to the same heat treatment as press molding. And the peel strength of the carrier foil after heating is measured, and the result is shown. Here, description will be made mainly on the case where an electrolytic copper foil is used as the carrier foil.
[0084]
First embodiment: In the present embodiment, an electrolytic copper foil which is not subjected to a roughening treatment and a rust prevention treatment classified into grade 3 having a thickness of 18 μm is used for the carrier foil C. Hereinafter, description will be made in accordance with the order of each step.
[0085]
First, the carrier foil C was pickled. The inside of the pickling tank is filled with a dilute sulfuric acid solution having a concentration of 150 g / l and a liquid temperature of 30 ° C., so that the carrier foil C is immersed in the carrier foil C for 30 seconds. The surface oxide film was removed.
[0086]
The bonding interface layer 2 was formed on the surface of the carrier foil C after the pickling treatment. The formation of the bonding interface layer 2 is such that the carrier foil C, which has been pickled and washed with water, is immersed in an aqueous solution having a CBTA concentration of 3500 ppm and an MBTA polymer of 5 ppm and a liquid temperature of 35 ° C. and a pH of 30 for 30 seconds. Then, the bonding interface layer 2 was formed on the surface of the carrier foil C and washed with water. The thickness of the bonding interface layer 2 obtained here was 10 nm on average.
[0087]
When the formation of the bonding interface layer 2 was completed, the bulk copper layer 3 constituting the electrolytic copper foil layer CF was formed on one side of the bonding interface layer 2 formed on both sides of the carrier foil C. The bulk copper layer 3 was formed by filling a copper electrolytic bath with a copper sulfate solution having a sulfuric acid concentration of 150 g / l, a copper concentration of 65 g / l, and a liquid temperature of 45 ° C. Then, in order to cathodicly polarize the carrier foil, one surface side of the carrier foil C after forming the bonding interface layer 2 immersed in this solution and a stainless steel plate serving as an anode electrode are separated from each other so as to be parallel to each other. did. Hereinafter, the same method was adopted when the electrolysis method was adopted. And a current density of 15 A / dm ² And a 3 μm thick bulk copper layer 3 was formed on the bonding interface layer on one side of the carrier foil C.
[0088]
When the formation of the bulk copper layer 3 was completed, the surface of the bulk copper layer 3 was subjected to a roughening treatment. In the roughening treatment, first, the fine copper particles 4 were attached and formed on the electrolytic copper foil layer CF, and cover plating was performed to prevent the fine copper particles 4 from falling off.
[0089]
The adhesion of the fine copper particles 4 is performed using a copper sulfate solution having a sulfuric acid concentration of 100 g / l, a copper concentration of 18 g / l, and a liquid temperature of 25 ° C., and a current density of 10 A / dm. ² This was performed by electrolysis under the burn plating conditions described above for 10 seconds.
[0090]
The overplating is a copper sulfate solution, using a copper electrolyte having a sulfuric acid concentration of 150 g / l, a copper concentration of 65 g / l, and a liquid temperature of 45 ° C., and a current density of 15 A / dm. ² By performing electrolysis for 20 seconds under the smooth plating conditions described above.
[0091]
When the roughening treatment is completed, in order to prevent corrosion of the carrier foil C and the surface of the electrolytic copper foil which has been subjected to the roughening treatment, in a rust prevention treatment step, zinc is deposited on both surfaces by electrolytic method to perform rust prevention treatment. Was. The conditions for depositing zinc here were as follows: a zinc sulfate bath, a sulfuric acid concentration of 70 g / l, a zinc concentration of 20 g / l, a liquid temperature of 40 ° C., and a current density of 15 A / dm. ² The conditions were adopted. Through the steps so far, the electrolytic copper foil 1 with a carrier foil was manufactured.
[0092]
When the rust prevention treatment was finally completed, the resultant was washed with water and finally dried to obtain a completed electrolytic copper foil with carrier foil 1a.
[0093]
The peel strength between the carrier foil layer C and the electrolytic copper foil layer CF of the electrolytic copper foil 1a with a carrier foil was measured. The values of the peel strength of each embodiment shown in the present specification shown below are all average values for 10 lots, and after heating for 1 hour when measuring 10 lots as an index for comparing the stability of the peel strength. The standard deviation of the peel strength is shown. As a result, the peel strength was 18 gf / cm before heating, 20 gf / cm after heating at 180 ° C. for 1 hour (standard deviation 0.54 gf / cm), and 22 gf / cm after heating at 230 ° C. for 1 hour (standard deviation 0). .88 gf / cm). In order to judge these values in comparison with a comparative example described below, it is necessary to ensure the reliability that the carrier foil C can be sufficiently prevented from peeling due to the handling during the press working, and it is extremely easy to manually perform the carrier operation even after heating. Since the foil can be removed and the standard deviation is extremely small, it can be seen that this is an ideal product that far exceeds the quality stability of the conventional electrolytic copper foil with carrier foil. It is.
[0094]
Second embodiment: In the present embodiment, an electrolytic copper foil which has not been subjected to a roughening treatment and a rust prevention treatment classified into grade 3 having a thickness of 18 μm is used for the carrier foil C. This was performed in the same manner as in the first embodiment. Therefore, these descriptions are omitted here to avoid duplication.
[0095]
When the formation of the bonding interface layer 2 is completed, an electrolytic copper foil layer CF is formed on one side of the bonding interface layer 2 formed on both sides of the carrier foil C. Here, the electrolytic copper foil layer CF has fine copper particles 4. Only type. Therefore, when the formation of the bonding interface layer 2 was completed, the surface of the bonding interface layer 2 was subjected to a roughening treatment. In the roughening treatment, first, the fine copper particles 4 were attached and formed on the electrolytic copper foil layer CF, and cover plating was performed to prevent the fine copper particles 4 from falling off. At this time, the same method as that of the first embodiment was employed for forming the fine copper particles 4 and plating. However, the formation of the adhesion of the fine copper particles 4 is different only in that the electrolysis is performed for 20 seconds under the same burn plating conditions, and the electrolysis time is lengthened to allow a sufficient amount of the fine copper particles 4 to adhere.
[0096]
As described above, when the formation of the electrolytic copper foil layer CF is completed, in the same manner as in the first embodiment, rust prevention treatment is performed, washed with water, and finally dried to complete the electrolytic copper foil with a carrier foil. A foil 1b was obtained.
[0097]
The peel strength between the carrier foil layer C and the electrolytic copper foil layer CF of the electrolytic copper foil with carrier foil 1b was measured. The values of the peel strength of each embodiment shown in the present specification shown below are all average values for 10 lots, and after heating for 1 hour when measuring 10 lots as an index for comparing the stability of the peel strength. The standard deviation of the peel strength is shown. As a result, the peel strength was 20 gf / cm before heating, 21 gf / cm after heating at 180 ° C. for 1 hour (standard deviation 0.54 gf / cm), and 25 gf / cm after heating at 230 ° C. for 1 hour (standard deviation 0). .88 gf / cm). In order to judge these values in comparison with a comparative example described below, it is necessary to ensure the reliability that the spontaneous peeling of the carrier foil C due to the handling at the time of press working can be sufficiently prevented, and it is very easy to perform manual work even after heating. Since the carrier foil C can be removed and the standard deviation is significantly reduced, it is an ideal product that far exceeds the quality stability of the conventional electrolytic foil with carrier foil. I understand.
[0098]
Third embodiment: In the present embodiment, a 18 μm-thick rolled copper foil which has not been subjected to a roughening treatment and a rust prevention treatment is used for the carrier foil C. Hereinafter, description will be made in accordance with the order of each step.
[0099]
Until the rolled foil as the carrier foil C was first pickled and the bonding interface layer 2 was formed on the surface thereof, the same method as in the first embodiment was performed. Therefore, these descriptions are omitted here to avoid duplication. The thickness of the bonding interface layer 2 obtained here was 11 nm on average.
[0100]
When the formation of the bonding interface layer 2 is completed, in order to manufacture the copper foil with carrier foil 1c having the electrolytic copper foil layers CF on both surfaces of the carrier foil C, the bonding interface layers 2 formed on both surfaces of the carrier foil C are respectively formed. Was formed a bulk copper layer 3 constituting an electrolytic copper foil layer CF. The bulk copper layer 3 was formed by filling a copper electrolytic bath with a copper sulfate solution having a sulfuric acid concentration of 150 g / l, a copper concentration of 65 g / l, and a liquid temperature of 45 ° C. Then, in order to cathodicly polarize the carrier foil C itself, a stainless steel plate serving as an anode electrode is spaced apart from each other on both sides of the carrier foil C after forming the bonding interface layer 2 immersed in this solution. And electrolyzed. Hereinafter, the same method was adopted when the electrolysis method was adopted. And a current density of 15 A / dm ² And a 3 μm thick bulk copper layer 3 was formed on each of the bonding interface layers 2 on both surfaces of the carrier foil C.
[0101]
When the formation of the bulk copper layers 3 on both surfaces was completed, the surface of each bulk copper layer 3 on both surfaces was roughened. In the roughening treatment, first, fine copper particles 4 were attached and formed on the bulk copper layer 3, and further, cover plating was performed to prevent the fine copper particles 4 from falling off.
[0102]
The same method as in the first embodiment was employed for the formation of the fine copper particles 4 and the plating. Therefore, in order to avoid redundant description, the description here is omitted. As described above, when the formation of the electrolytic copper foil layer CF is completed, in the same manner as in the first embodiment, both surfaces are subjected to rust prevention treatment, washed with water, and finally dried to complete a carrier foil. An electrolytic copper foil 1c was obtained.
[0103]
The peel strength between the carrier foil layer C and the electrolytic copper foil layer CF of the electrolytic copper foil with carrier foil 1c was measured. As a result, the peel strength of the carrier foil C on one side was 18 gf / cm before heating, 19 gf / cm after heating at 180 ° C. for 1 hour (standard deviation 0.54 gf / cm), and after heating at 230 ° C. for 1 hour. It was 21 gf / cm (standard deviation 0.88 gf / cm). The peel strength of the carrier foil C on the other side is 20 gf / cm before heating, 22 gf / cm (standard deviation 0.54 gf / cm) after heating at 180 ° C. for 1 hour, and after heating at 230 ° C. for 1 hour. It was 24 gf / cm (standard deviation 0.88 gf / cm).
[0104]
In order to judge these values in comparison with a comparative example described below, it is necessary to ensure the reliability that the spontaneous peeling of the carrier foil C due to the handling at the time of press working can be sufficiently prevented, and it is very easy to perform manual work even after heating. Since the carrier foil C can be removed and the standard deviation is significantly reduced, it is an ideal product that far exceeds the quality stability of the conventional electrolytic foil with carrier foil. I understand.
[0105]
Fourth embodiment: In this embodiment, a rolled copper foil having a thickness of 18 μm, which has not been subjected to a roughening treatment and a rust preventive treatment, is used for the carrier foil C, and the pickling treatment and the formation of the bonding interface layer are performed in the same manner as in the third embodiment. I went in. Therefore, these descriptions are omitted here to avoid duplication.
[0106]
When the formation of the bonding interface layer 2 is completed, the electrolytic copper foil layer CF is formed on both sides of the bonding interface layer 2 formed on both sides of the carrier foil C. Here, the electrolytic copper foil layer CF has fine copper particles 4. Only type. Therefore, when the formation of the bonding interface layer 2 was completed, the surface of the bonding interface layer 2 was subjected to a roughening treatment. In the roughening treatment, first, fine copper particles 4 were attached and formed on the bonding interface layer 2, and cover plating was performed to prevent the fine copper particles 4 from falling off. At this time, the same method as that of the third embodiment was employed for the formation of the fine copper particles 4 and the overplating. However, the formation of the adhesion of the fine copper particles 4 is different only in that the electrolysis is performed for 20 seconds under the same burn plating conditions, and the electrolysis time is lengthened to allow a sufficient amount of the fine copper particles 4 to adhere.
[0107]
As described above, when the formation of the electrolytic copper foil layer CF is completed, in the same manner as in the first embodiment, rust prevention treatment is performed, washed with water, and finally dried to complete the electrolytic copper foil with a carrier foil. A foil 1d was obtained.
[0108]
The peel strength between the carrier foil layer C and the electrolytic copper foil layer CF of the electrolytic copper foil 1d with a carrier foil was measured. As a result, the peel strength of the carrier foil C on one side was 18 gf / cm before heating, 19 gf / cm after heating at 180 ° C. for 1 hour (standard deviation 0.54 gf / cm), and after heating at 230 ° C. for 1 hour. It was 21 gf / cm (standard deviation 0.88 gf / cm). The peel strength of the carrier foil C on the other side is 20 gf / cm before heating, 22 gf / cm (standard deviation 0.54 gf / cm) after heating at 180 ° C. for 1 hour, and after heating at 230 ° C. for 1 hour. It was 24 gf / cm (standard deviation 0.88 gf / cm).
[0109]
To judge these values in comparison with the comparative example described below, it is necessary to ensure the reliability that the carrier foil can be sufficiently prevented from peeling due to the handling during the press working, and it is extremely easy to manually perform the carrier foil after heating. Can be removed, and the standard deviation is extremely small, indicating that this is an ideal product that far exceeds the quality stability of the conventional electrolytic copper foil with carrier foil. is there.
[0110]
Comparative example: In this comparative example, an electrolytic copper foil which had not been subjected to a roughening treatment and a rust prevention treatment classified into grade 3 having a thickness of 18 μm was used for the carrier foil. Hereinafter, description will be made in accordance with the order of each step.
[0111]
First, the carrier foil was pickled. The inside of the pickling tank is filled with a dilute sulfuric acid solution having a concentration of 150 g / l and a liquid temperature of 30 ° C., and the carrier foil is immersed in the solution for 30 seconds to remove the fat component attached to the carrier foil 3. Then, the surface oxide film was removed.
[0112]
A bonding interface layer was formed on the surface of the carrier foil 3 after the pickling treatment. The formation of the bonding interface layer is performed such that the carrier foil that has been washed with water after the completion of the pickling treatment contains only CBTA at a concentration of 5 g / l and is immersed in an aqueous solution having a liquid temperature of 40 ° C. and a pH of 30 for 30 seconds. A bonding interface layer 8 was formed on the surface of the carrier foil 3 and washed with water. The thickness of the bonding interface layer 8 formed of only CBTA obtained here was 11 nm on average. However, the bonding interface layer composed of only CBTA varies between 2 nm and 25 nm depending on the place observed with a TEM, and lacks uniformity in film thickness.
[0113]
When the formation of the bonding interface layer is completed, on one side of the bonding interface layer formed on both sides of the carrier foil, a bulk copper layer forming a bulk copper layer constituting an electrolytic copper foil layer, and fine copper particles are attached and plated. The electrolytic copper foil with the carrier foil for comparison was manufactured by performing a roughening treatment, a rust prevention treatment, and a drying treatment. Since these manufacturing conditions are the same as in the first embodiment, a detailed description thereof will be omitted here to avoid redundant description.
[0114]
The peel strength between the carrier foil layer and the electrolytic copper foil layer of the electrolytic copper foil with the carrier foil was measured. The values of the peel strength of each embodiment shown in the present specification shown below are all average values for 10 lots, and after heating for 1 hour when measuring 10 lots as an index for comparing the stability of the peel strength. The standard deviation of the peel strength is shown. As a result, the peel strength was 18 gf / cm before heating, 25 gf / cm (standard deviation 2.73 gf / cm) after heating at 180 ° C. for 1 hour, and 257 gf / cm (standard deviation 12) after heating at 230 ° C. for 1 hour. .31 gf / cm). These values are determined in comparison with the above-described embodiments.As the heating temperature increases, the peeling strength of the carrier foil increases, and particularly after heating at 230 ° C., a remarkably high value is obtained. It is no longer possible to say that the carrier foil can be easily removed by hand. In addition, the standard deviation is larger than in each embodiment.
[0115]
【The invention's effect】
The electrolytic copper foil with a carrier foil according to the present invention, by using a solution containing CBTA and MBTA polymer to form a bonding interface layer, peeling at the interface between the carrier foil layer and the electrolytic copper foil layer after heating. It can be easily performed with a very small force, and the variation in quality between products is very small. In addition, the production of the electrolytic copper foil with a carrier foil according to the present invention is characterized in that an aqueous solution containing CBTA and MBTA polymer is used for forming the bonding interface layer. Because of the manufacturing process, the manufacturing yield of the product is dramatically improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an electrolytic copper foil with a carrier foil.
FIG. 2 is a schematic cross-sectional view of an electrolytic copper foil with a carrier foil.
FIG. 3 is a schematic diagram showing a lay-up configuration during press molding.
FIG. 4 is a schematic diagram showing a lay-up configuration during press molding.
FIG. 5 is a schematic diagram showing a lay-up configuration during press molding.
FIG. 6 is a schematic cross-sectional view of an electrolytic copper foil with a carrier foil.
FIG. 7 is a schematic cross-sectional view of an electrolytic copper foil with a carrier foil.
FIG. 8 is a schematic cross-sectional view of an electrolytic copper foil with a carrier foil.
FIG. 9 is a schematic diagram showing a lay-up configuration during press molding.
FIG. 10 is a schematic diagram showing a lay-up configuration during press molding.
FIG. 11 is a schematic cross-sectional view of an electrolytic copper foil with a carrier foil.
FIG. 12 is a schematic view illustrating a production flow of an electrolytic copper foil with a carrier foil.
[Explanation of symbols]
1a-1h Electrolytic copper foil with carrier foil
2 Bonding interface layer
3 Bulk copper layer
4 Fine copper grains
C Carrier foil
CF electrolytic copper foil layer

Claims (8)

On one side of the carrier foil, provided with a bonding interface layer, in the electrolytic copper foil with a carrier foil having an electrolytic copper foil layer on the bonding interface layer,
The bonding interface layer includes a polymer of carboxybenzotriazole (hereinafter, referred to as “CBTA”) and methylbenzotriazole (hereinafter, referred to as “MBTA”) (hereinafter, simply referred to as “MBTA polymer”). An electrolytic copper foil with a carrier foil, wherein the electrolytic copper foil is formed using a contained solution, and the MBTA polymer contained in the bonding interface layer is 2.0 wt% to 60.0 wt%. The electrolytic copper foil with a carrier foil according to claim 1, wherein the electrolytic copper foil layer is constituted only by fine copper particles deposited and adhered by an electrolytic method. On both sides of the carrier foil, provided with a bonding interface layer, in the electrolytic copper foil with a carrier foil having an electrolytic copper foil layer on each of the bonding interface layers,
The bonding interface layer is formed using a solution containing CBTA and MBTA polymer, and the MBTA polymer contained in the bonding interface layer is 2.0 wt% to 60.0 wt%. An electrolytic copper foil with a carrier foil. The electrolytic copper foil with a carrier foil according to claim 3, wherein the electrolytic copper foil layer is composed of only fine copper particles deposited and adhered by an electrolytic method. The electrolytic copper foil with a carrier foil according to any one of claims 1 to 4, wherein the carrier foil is an electrolytic copper foil. The electrolytic copper foil with a carrier foil according to claim 1, wherein the bonding interface layer has a thickness of 0.5 nm to 1 μm. In the method for producing an electrolytic copper foil with a carrier foil according to any one of claims 1 to 6,
The bonding interface layer is formed on the surface of the carrier foil by using a solution containing 50 ppm to 5000 ppm of CBTA and 2 ppm to a saturated solubility of MBTA polymer to form the organic film by adsorbing the organic agent. Characteristic method for producing electrolytic copper foil with carrier foil. A copper-clad laminate obtained using the electrolytic copper foil with a carrier foil according to any one of claims 1 to 6.

Images