JP3968269B2 - Electroless copper plating solution, its management method, and electroless copper plating apparatus - Google Patents

Description

【００１４】
これらの反応以外にも、めっき液中においては下記に示すような酸化銅の生成及び酸化銅の自己分解反応により溶液中における銅が析出し、浴の安定性が著しく低下する。
【００１５】
【化２】

【００１６】
このようにめっき組成は常に一定ではなく、刻々とその組成は変化する。めっきを安定に行うためには、浴の安定性を向上させること、すなわち副反応であるカニッツアロ反応を抑制すること（還元剤濃度減少をめっき反応によるもののみにする）、酸化銅の生成及び酸化銅の自己分解反応を抑制し（銅イオン濃度の減少をめっき反応によるもののみにする）、還元剤濃度及び銅イオン濃度を一定に保つことが必要である。酸化銅の生成及び酸化銅の自己分解反応を抑制するためには1価の銅を安定化する必要があり、めっき液の空気撹拌や安定化剤が添加されている。
【００１７】
ホルムアルデヒドを還元剤とした場合において、安定化のための添加剤としては、1価の銅と優先的に結合し錯体を形成するシアン化合物、ビピリジル、O-フェナントロリン、チオ尿素などが用いられている。また、通常高アルカリ条件で使用されるが、このような条件においても、銅イオンが沈殿しないように遊離している銅イオンの濃度を低下させる錯化剤が使用される。工業的にはロッセル塩、ＥＤＴＡ等が使用されており、安定化させるためにはある程度の濃度が必要となる。
【００１８】
還元剤としてグリオキシル酸を使用し、錯化剤として酒石酸塩を使用する例として、特公平2-24910号公報には、銅イオン源の濃度が0.0078〜0.63モル、酒石酸塩は銅イオンのモル濃度の少なくとも６倍であり、又グリオキシル酸イオン源の有効モル濃度が0.01〜1.5モルで、具体例として銅イオンのモル濃度に対して2.13倍であることが記載されている。
【００１９】
カニッツアロ反応を抑制し、アルデヒド系の還元剤濃度の減少を抑制するためには、ｐH調整剤としてNaOHよりもKOHを使用することが有効であることが「表面技術 vol.42、 No.9、 913-917(1991)」や「プリント回路実装学会第6回学術講演大会予稿集101-102」に示されている。また特開2000-144438では、めっき液にメタノールを添加することが行われているが、この方法はカニッツアロ反応そのものを抑制するわけではないので、効果には一定の限界があることが記載されている。
【００２０】
しかしながら特に無電解銅めっき液の還元剤としてグリオキシル酸を使用した場合には、ホルムアルデヒドを使用した場合と比較して、カニッツアロ反応が速い速度で進行する。また酸化銅の自己分解反応による銅イオン濃度の減少量が多く、ホルムアルデヒドと比較してめっき浴を安定化させることが困難である。従って、めっき液の主成分である還元剤濃度、銅イオン濃度、ｐＨ（水素イオン濃度）は常に変化する。
【００２１】
グリオキシル酸を還元剤として使用する場合の液組成として、特公平2-24910においては前述のようにそれぞれの領域が単独で示されているが、実際において、めっき反応が進行するためにはｐH、還元剤濃度、銅濃度及び温度の各パラメータがお互いに作用し合うために、それぞれのパラメータの濃度を独立に規制していては、めっき反応を起こさせることができなくなる可能性が有る。
【００２２】
また、めっき反応が進行するにつれてｐH、還元剤濃度、及び銅濃度が変化した場合、これらの領域からめっき条件がはずれ、めっき反応が安定に進行しなくなる可能性が生じる。上記のようにグリオキシル酸を還元剤として使用した場合は、カニッツァロ-反応や銅の自己分解反応がホルムアルデヒドを使用した場合よりも生じやすいために、めっき初期におけるめっき浴の組成がめっきできる条件であっても、めっきが進むにつれてめっき浴の組成がめっきできる条件から外れやすい。
【００２３】
さらに、錯化剤の種類が換わると、回路実装学会誌、vol.10 〔2〕1995 p.118-ｐ.122「グリオキシル酸を還元剤とする無電解銅めっきの析出過程」に記されているように、めっきの反応性が変化し、グリオキシル酸の濃度が0.25Mの場合、0.06Mの酒石酸を使用した場合にはめっき反応が始まるまで10分程度の時間が必要である。通常、めっき時間は15〜20分程度であることから、酒石酸塩を錯化剤とた場合には、回路実装学会誌、vol.10 〔2〕1995 p.118-ｐ.122「グリオキシル酸を還元剤とする無電解銅めっきの析出過程」に記された条件では実質のめっき時間は5〜10分以内となり、十分なめっき厚みを得ることができない。また、0.06MのEDTAを錯化剤に使用した場合には数秒でめっき反応が開始される。従って、錯化剤の種類によりめっき反応性は異なり、酒石酸塩を錯化剤として使用する場合においては、めっき反応開始時間をいかに速くするかという問題が生じる。
【００２４】
本発明においては、低温薄付け用を目的としている。重要なのはめっき液が分解反応を起こさず安定であること、めっきが均一であり、めっきの組成がある程度変化した場合においても、いつでも同じ状態であることである。
【００２５】
しかしながら、前述した安定剤の検討においては、還元剤がホルムアルデヒド等の場合に検討されたものが多く、グリオキシル酸を還元剤とした場合では、添加による安定性を得ることが必ずしもできない物質も含まれている。例えば、還元剤にグリオキシル酸を、錯化剤にＥＤＴＡを使用した場合、ビピリジルは20ppm添加しても、銅イオンの安定化を図ることができなかった。さらにこれらの添加剤中で銅イオンの安定性を向上させるには有効であっても、同時に銅の析出反応も抑制してしまうことが多い。特にグリオキシル酸を還元剤として使用した場合は、その抑制率は、添加する安定剤の濃度に対して正比例的に変化せず速度の制御が困難であるばかりか、ある程度の濃度を超えるとめっき反応が急激に完全に停止してしまうことがある。これを改善するために、速度調整剤を併せて添加する方法も考えられている。しかし、特に薄付け用のめっきでは、基板の出し入れの回数が多く、まためっき液の補給が頻繁になされるために、めっき液の組成は一定せず絶えず変動する。従って、めっき速度も常に変動し、前述しためっき速度調整剤を使用した場合においても同様である。めっきは通常一定時間実施されることから、特にめっき速度が変化した場合（後述するようにめっき速度が速くなっても、遅くなってもどちらの場合においても）、スルーホール内が十分にめっきされないことが生じ、これが原因となって、その後に実施される電気めっきによって生成する銅皮膜の膨れや、スルーホール内壁との密着不良が生じる。
【００２６】
本発明の目的は、グリオキシル酸を還元剤とした銅めっき液を使用することにより、人体及び環境への影響を軽減することができ、又、長時間に亘って安定で均一なめっきを行うことができる無電解銅めっき液とその液管理方法、及び装置を提供するにある。
【００２７】
【課題を解決するための手段】
本発明は、ホルムアルデヒドを使用しない無電解銅めっき液にあり、特に還元剤として少なくともグリオキシル酸を含む特定のめっき液組成にある。グリオキシル酸を還元剤として使用した場合において、銅めっき反応を起こさせ、それを継続（連続的に安定めっき）をさせ、さらにめっき液の安定性を保つためには還元剤濃度、ｐＨ、銅イオン濃度、錯化剤濃度及び温度をある濃度範囲に制御するとともに、添加剤の濃度制御をする必要性がある。前述したように、錯化剤が変わると、還元剤が同じでもめっき挙動は異なる。特に酒石酸塩を使用した場合は、他の錯化剤を使用した場合とは挙動は大きく異なる。そこで、ここでは、その解決手段を錯化剤の代表としてEDTAの場合と酒石酸塩の場合に分けて記述する。
【００２８】
まず、本発明においてグリオキシル酸を還元剤、エチレンジアミンテトラ四酢酸（ＥＤＴＡ）を錯化剤として使用した場合について説明する。本発明におけるめっき液の構成は、銅塩、第二銅イオン錯化剤、還元剤、ｐＨ調整剤のほか各種添加剤からなる。
【００２９】
添加剤に関しては、以下のようである。グリオキシル酸を還元剤とした場合において、種々のめっき抑制効果を示す添加剤及びめっき安定性を示す添加剤を複数組み合わせ無電解銅めっきを実施した後、スルーホール内のめっき状況を観察した結果、スルーホール内を均一にめっきできる条件は、添加剤の種類にかかわらず、樹脂板上におけるめっき速度が0.5〜2.0μｍ/ｈになるように添加剤が加えられた場合であることがわかった。これは、めっき速度が遅い場合は、めっきができず不均一になるのは当然のことであるが、逆にめっき速度が速い場合は、銅張り積層板上の表面上におけるめっき反応が進むために、銅イオンがスルーホール内まで拡散する量が減少し、スルーホール内の銅濃度が低下するためと考えられる。
【００３０】
従来の技術の項で示した銅イオン安定剤は、数ppmでも十分な銅イオン安定性をもたらすが、この安定剤を用いて樹脂板上におけるめっき速度を0.5〜2.0μｍ/ｈに調整するために添加しなければならない濃度は最低でも十数ppm以上が必要となる。しかし、前述したようにこれら添加剤を数十ppmまで添加すると、濃度変化に対するめっき速度の変動が大きく、時にはめっき反応を急激に停止してしまう場合が多い。
【００３１】
また、第１種添加剤としてのめっき液を安定化させる添加剤の濃度を低く抑えて、さらに第２種添加剤として速度調整剤を添加することが考えられる。しかし、連続的にめっきを行う場合は、めっき反応以外にも基板の出し入れ（基板は水にぬれた状態でめっき槽に入り、めっき液がついた状態でめっき槽から出て行く）により銅イオン濃度、還元剤濃度、アルカリ濃度、第１種添加剤濃度、第２種添加剤濃度等が変化（減少）する。第２種添加剤は、その添加によって速度を調整するもの（第２種添加剤はその濃度に対してめっき速度が正比例的に変化するものである）であるが、連続めっきによりその濃度が変化するために、めっき速度が0.5〜2.0μｍ/ｈの間に入らなくなリ、スルーホール内が均一にめっきされなくなる恐れがある。
【００３２】
これらを改善するには、さらに第３種添加剤として、それ自身の濃度及び速度調整剤である第２種添加剤の濃度が変化してもめっき速度の変化が小さい、すなわち速度緩衝性のある添加剤を組み合わせることにより本目的を達成することが可能となる。
【００３３】
ここで重要なことは、第２種添加剤を加えることにより第１種の添加剤を加える目的である銅イオン安定性の効果がなくならないことであり、第１種添加剤を加えることにより第２種添加剤による速度調整に変化が生じないこと、第２種添加剤の濃度がある程度ある場合には第２種添加剤の濃度でめっき速度が決定されるが、第２種の濃度が減少した場合でも第３種添加剤の存在により、めっき速度が変化せず第２種添加剤がある程度存在した場合と同等の速度が得られること、さらに第1種添加剤〜第３種添加剤とが共存した場合において第３種添加剤の濃度によってめっき速度が変化しないことである。これは第３種添加剤によるめっき速度抑制効果は、第２種添加剤のめっき速度抑制効果より小さいためである。すなわち第２種添加剤の濃度が濃い場合は、めっき速度は第２種添加剤の添加によって一義的に決まるが、第２種添加剤の濃度が減少し抑制効果が小さくなると、第３種添加剤による抑制効果が現れてその複合により、結果的には第２種添加剤の濃度が減少した場合においても、第２種添加剤がある程度存在した場合と同等のめっき速度を一定に保つことができる。さらにめっき中はカニッツアロー反応、酸化銅生成―酸化銅の不均化反応等によりしゅう酸イオン、硫酸イオン、グリコール酸が蓄積するが、これらの物質は後述するように第３種添加剤として使用することが可能な物質であり、めっき反応が進行してもめっき速度の変化はなくなる。これによりめっき速度を一定に保つことができる。さらに銅濃度及びｐＨが変化した場合においても、第１種添加剤、第２種添加剤及び第３種添加剤を加えることにより、めっき速度を0.5〜2.0μｍ/ｈの間に制御することが可能となる。
【００３４】
第１に、本発明は、銅イオン、銅イオンの錯化剤、還元剤及びｐＨ調整剤からなる無電解銅めっき液に、（１）第１種添加剤として、環状部にイオウ元素又は窒素元素を有する有機化合物ないしは無機イオウ化合物から選ばれる少なくとも１つ以上、（２）第２種添加剤として、α−α´ビピリジル、ＩＶＢ族の酸化物又は酸素酸塩、ないしはＶＡ又はＶＩＡ族の酸素酸塩又は酸化物から選ばれる少なくとも１つ以上、さらに（３）第３種添加剤として、オキシアルキレングリコール、硫酸塩、しゅう酸塩、炭酸塩、硝酸塩又はグリコール酸から選ばれる少なくとも１つ以上を含む水溶液であることを特徴とする無電解銅めっき液である。
【００３５】
ここで、これら第１種添加剤としては、ベンゾチアゾール、チアゾール、ニコチン酸、ベンゾトリアゾール、メルカプトコハク酸で代表される環状部にイオウ元素（Ｓ）又は窒素元素（Ｎ）を有する有機化合物、ないしはポリ硫化カリウム、硫化カリウム、硫化ナトリウム、で代表される無機イオウ化合物の少なくとも１つ以上を添加するものであり、また第２種添加剤としては、α−α´ビピリジルの他メタケイ酸ナトリウム、ゲルマニウム酸塩、二酸化ゲルマニウム、スズ酸ナトリウムで代表されるＩＶＢ族の酸化物ないし酸素酸塩、又はモリブデン酸ナトリウムやメタバナジン酸ナトリウムで代表されるＶＡ又はＶＩＡ族の酸素酸塩又は酸化物の少なくとも一つ以上を添加することが挙げられる。第３種添加剤としては、ポリエチレングリコールで代表されるポリアルキレングリコール、硫酸ニッケルや硫酸カリウムで代表される硫酸塩、しゅう酸カリウムで代表されるしゅう酸塩、炭酸ナトリウムで代表される炭酸塩、硝酸カリウムで代表される硝酸塩、又はグリコール酸の少なくとも１つ以上があげられる。
【００３６】
第１種及び第２種添加剤の濃度は、0.01〜100mg/L、第３種添加剤の濃度は、100mg/L以上であることが望ましい。第３種添加剤としてポリエチレングリコールを使用した場合は、その分子量にとくに制限はないが、使用する分子量が大きいほど、その濃度は小さくて良い。
【００３７】
その他構成要素である銅塩、第二銅イオン錯化剤、還元剤、ｐＨ調整剤は以下のようである。無電解銅めっき液に使用される銅塩としては、可溶性銅塩であり、一般的には硫酸銅、塩化第二銅、ピロリン酸銅等が使用され、その濃度は0.01〜0.08mol/L程度が適当である。第二銅塩の錯化剤としては、ＥＤＴＡあり、その濃度は0.02〜0.16mol/L程度が適当である。還元剤としては、グリオキシル酸を使用する。その濃度は、0.1〜0.3mol/Lが適当である。
【００３８】
後述するように酒石酸塩を錯化剤にした場合は、グリオキシル酸/銅濃度、酒石酸塩/銅濃度の比がめっきする上で重要である。しかし、ＥＤＴＡを錯化剤とした場合は、このような錯化剤、還元剤、銅濃度のそれぞれの比はそれほど重要ではない。反応速度を上げる場合、前述したように、通常は銅濃度及び還元剤の濃度を上げることが必要である。所定の濃度のグリオキシル酸及びＥＤＴＡを含む溶液中（ｐＨ調整後）において銅上におけるグリオキシル酸のアノード分極曲線を測定すると、グリオキシル酸の濃度を増加させてもグリオキシル酸の酸化電流は濃度に比例して増加せず、ほとんど変化しない。このことからグリオキシル酸の濃度を増加させても反応速度をあげることはできないことが分かる。また、錯化剤に酒石酸塩を使用した場合とは異なり、銅濃度を上げても銅の電位は、酸化銅が生成する電位まで上昇しない。そのため、グリオキシル酸/銅濃度の比はそれほど重要とはならない。
【００３９】
ｐH調整剤としては、一般的には水酸化ナトリウムが使用されている。しかし本発明においては、ＫＯＨを使用した。その理由は前述した通りである。めっき液のｐHはスルーホール内のめっきの均一性及び付きまわりは向上することから、10以上とするのが好ましく、望ましくは１１．５〜１３．５が良い。であり、ｐＨが高い程、めっき液のｐＨは12.0以上であることが望ましい。しかし、ｐＨが高いほどカニッツアロ反応によるグリオキシル酸の自己分解反応が進むことを考慮すると、よりｐＨは12〜13の範囲が望ましい。
【００４０】
本発明の無電解めっき方法として、めっきにおける温度は、高温でのグリオキシル酸の自己分解反応の抑制に関する問題から、50℃以下、好ましくは20〜45℃である。めっき時間は、長くするとスルーホール内のめっきの付きを良くすることは当然であるが、作業効率が低下する。本発明においては、めっき時間は、１５〜２５分が最適である。プリント基板の回路を作成するための無電解めっきを行う前に、通常基板を活性化させることが必要であり、一般的にパラジウムで代表される貴金属触媒を吸着させて行う。この工程は次に示す4段階からなる。（1）まず過硫酸塩等を用いてソフトエッチングを行う。（2）ついで予備液に漬けた後に、（3）基板を塩化錫の酸性溶液中にパラジウムのコロイドを懸濁させた溶液に接触させる。（4）最後に促進剤に浸漬させて錫を表面から取り除く。この基板に本発明の実施例の無電解めっき液を用いて無電解銅めっき液処理を施す。このプリント基板の回路作成方法は、酒石酸塩を錯化剤とした場合と同様である。
【００４１】
また、本発明は、銅イオン、銅イオンの錯化剤、還元剤、ｐＨ調整剤及び第1種〜第３種還元剤を含む銅めっき液を収納するめっき槽中に被めっき材を浸漬し、無電解銅めっきをする無電解銅めっき装置において、前記還元剤がグリオキシル酸及びその塩で、その濃度が0.1〜0.3Ｍ程度、及び前記錯化剤がＥＤＴＡでその濃度が0.02〜0.16Ｍ、ｐＨが12.0〜13.0、及び前記第１種、２種還元剤濃度が0.01〜100ｍｇ/Ｌ及び前記第３種添加剤濃度が100ｍｇ/Ｌ以上になるように前期還元剤を補給する還元剤補給手段及び前期銅イオンを補給する銅イオン補給手段及び前記ｐＨ調整剤を補給するｐＨ調整剤補給手段及び前記第1種〜第３種添加剤を補給する添加剤補給手段を有すること又、めっき槽中にめっき温度を所定の温度に制御する温度制御装置を特徴とする。
【００４２】
次いで、本発明において、グリオキシル酸を還元剤、酒石酸塩を銅イオンの錯化剤として使用した場合について説明する。種々の還元剤濃度、銅イオン濃度、錯化剤濃度、ｐＨ及び温度を調整してめっきを行った結果、特定のめっき温度とすることによって長時間に亘って使用可能である銅めっき液組成を見出したものである。すなわち、還元剤濃度と銅イオン濃度の比がそれぞれの濃度の絶対値に関係するのではなく、還元剤の濃度が常に銅イオン濃度の8.0倍以上、好ましくは8.3倍以上、より望ましくは8.5〜30倍、錯化剤の濃度が銅イオンモル濃度の6倍以下、望ましくは0.8〜5倍であり、両者の比が重要であり、まためっき温度は50℃以下、より好ましくは20〜45℃とするものである。銅イオン濃度は、0.01〜0.1モル、より0.01〜0.05モルが好ましい。
【００４３】
連続的に長期にわたってめっきする場合は、この条件になるように、めっき初期から常にめっき液の組成をこのようになるように制御することにより安定しためっきを施すことができる。またこの濃度の範囲にめっき液の組成を制御することにより、めっきが開始されるまでの時間が1分以内にまで短縮される。銅のめっき反応式は、グリオキシル酸を還元剤として使用した場合、(2)式で表される。反応速度論に従えば、通常めっき反応速度を増加させるには、銅イオン濃度及びグリオキシル酸濃度を上げることが必要である。
【００４４】
しかしながら所定の濃度のグリオキシル酸及び酒石酸塩を含む溶液中（ｐＨ調整後）において銅上におけるグリオキシル酸のアノード分極挙動を測定すると、グリオキシル酸の濃度を増加させてもグリオキシル酸の酸化電流密度は濃度に比例して増加せずほとんど変化しないことから、グリオキシル酸の濃度を増加させてめっき反応速度を上げることはできない。一方で、銅濃度を増加させると、電位が上昇し、銅の電位は酸化銅が生成する電位領域になり、酸化銅生成によりめっき反応が停止してしまう。
【００４５】
銅は、水中においては下記のような平衡状態にあり、酸化還元電位は次式によって与えられる。
【００４６】
【化３】

【００４７】
（9）及び（10）の式中にあるＥ₀は、それぞれの反応の標準酸化還元電位であり、２５℃においては（9）式のＥ₀は0.471（Ｖ）、また（10）式のＥ₀は0.609（Ｖ）である。従って、少なくとも銅の電位が（9）式で表されるE以下の値にならないと、銅が析出しなくなる。ここでＥはＳＨＥ（その温度における標準水素電極電位）基準で表した電位である。銅イオンの還元反応を生じさせかつ銅の電位がこのような電位領域に入るためには、銅イオンモル濃度に対するグリオキシル酸モル濃度が8倍以上であることが必要であることを見出した。すなわち、グリオキシル酸を還元剤とした場合に、銅のめっき反応を連続的に生じさせるのに必要なグリオキシル酸及び銅イオンモル濃度の絶対値（閾値）が存在するのではなく、グリオキシル酸と銅イオンとのモル濃度比に閾値が存在し、そのモル濃度比を8.3以上とするのが好ましい。
【００４８】
本発明において、グリオキシル酸とグリオキシル酸塩、酒石酸及び酒石酸塩の用語は特に指定しない限り互換性があるものである。これはｐHによってそれらの形態が変化するためである。銅イオン源としては、可溶性銅塩であり、一般的には硫酸銅、塩化銅等が使用される。適切な銅イオン濃度は、前述のようにグリオキシル酸の濃度との比によって決定され、たとえばグリオキシル酸濃度が0.24Mの場合におけるめっき可能な銅イオン濃度は0.029M以下であり、好ましくは0.024M以下であることが望ましい。
【００４９】
錯化剤は酒石酸、ロッセル塩又は酒石酸カリウムで代表される酒石酸塩を含むものであり、その適正濃度は0.01〜0.2モル、好ましくは0.02〜0.1モルであり、銅イオン濃度との比で決定される。錯化剤は水溶液中において銅イオンが酸化物又は水酸化物あるいは銅蓚酸塩などの不溶性化合物を析出しないために必要であり、その銅イオンを安定に存在させるために必要な最低濃度はｐHによって決定され、その濃度以上に錯化剤の濃度が必要となる。しかしながら、酒石酸自身が還元力を持つために過剰に添加すると、銅イオンを還元してしまうために上限の濃度があり、まためっき反応を安定に進行させるのにも酒石酸を過剰に添加することは好ましくない。また銅イオン濃度に対して酒石酸濃度が過剰にある場合は、めっき反応が開始するまでに5分以上の時間を要するようになる。適正な濃度は、酒石酸モル濃度が銅モル濃度の6倍以下であり、望ましくは5倍以下である。
【００５０】
還元剤は、グリオキシル酸又はグリオキシル酸塩を含むものものであり、その濃度は0.05〜1.0モル、より0.1〜0.5モルが好ましく、又前述のように、銅イオン濃度との比で決定される。ｐH調整剤としては、一般的には水酸化ナトリウムが使用されている。しかし、グリオキシル酸を還元剤としためっき液に関して、ｐH調整剤にNaOHでなくKOHを使用することにより、NaOHを使用した場合と比較してカニッツアロ反応を抑制できることが「表面技術、vol.42、No.9、913-917(1991)」や「プリント回路実装学会第6回学術講演大会予稿集101-102」に開示されている。
【００５１】
また、めっき反応及びカニッツアロ反応によって蓚酸イオンが生成するが、蓚酸カリウムは蓚酸ナトリウムと比較して溶解度が高く析出しにくいために、基板上への析出等によるめっきボイド等の生成による問題が軽減する。従って、めっき液に使用するｐH調整剤としてはKOHを使用することが望ましい。まためっき液のｐHは、好ましくはKOHを用いて10以上とするのが好ましく、望ましくは11.5〜13.5、より12.0〜13.0であることが望ましい。その他、必須事項ではないが、長期にわたってめっきを実施する場合においては、酸化銅生成―酸化銅の自己分解反応による銅粒子の液中における析出防止のための安定剤、速度調整剤を添加することが好ましい。ここで添加される安定剤や速度調整剤は、ホルムアルデヒドを還元剤としためっき液の場合と同様なものである。安定剤、還元剤の種類と特徴に関しては、たとえば「表面技術便覧 (社)表面技術協会編 P.336」に記載されており、代表的なものとしてはシアン化合物、2、2´―ビピリジル、硫黄が2価である有機硫黄含有機物、ポリエチレングリコールなどがある。
【００５２】
本発明の無電解めっき方法として、めっきにおける温度は、高温での酒石酸の安定性及びグリオキシル酸の自己分解反応の抑制に関する問題から、50℃以下、好ましくは20〜45℃である。また銅イオンの安定性を上げるためには安定剤の添加以外の方法としては、めっき液が撹拌されることが望ましい。撹拌の方法としては、エアー撹拌、スターラーによる撹拌等があり、安定剤の添加によりさらに効果を上げることができる。プリント基板の回路を作成するための無電解めっきを行う前においては、通常基板を活性化させることが必要であり、一般的にパラジウムで代表される貴金属触媒を吸着させて行う。この工程は次の4段階からなる。（1）まず過硫酸塩等を用いてソフトエッチングを行う。（2）ついで予備液に漬けた後に、（3）基板を塩化錫の酸性溶液中にパラジウムのコロイドを懸濁させた溶液に接触させる。（4）最後にアルカリの促進剤に浸漬させて錫を表面から取り除く。この基板に本発明の実施例の無電解めっき液を用いて無電解銅めっき液処理を施す。
【００５３】
本発明においては、連続的に安定してめっきを実施する場合、めっき液の補給方法にある。めっき反応以外にカニッツアロ反応、酸化銅生成―酸化銅の自己分解反応、及び基板からの持ち出し（基板は水にぬれた状態でめっき槽に入り、めっき液がついた状態でめっき槽から出て行く）により銅イオン濃度、還元剤濃度、アルカリ濃度等が減少する。従って、めっきを継続して行うためには、適宜めっき液を補給することが必要となる。めっき反応及び副反応による銅濃度、アルカリ濃度、還元剤濃度の減少率は異なるために、それぞれ補給する量は異なる。従って、めっき液を補給する際は、めっき槽中のめっき液がめっきできる組成になるように銅イオン源、アルカリ及び還元剤を個別に補給する必要性がある。その場合、めっき液の組成が銅イオンモル濃度に対するグリオキシル酸モル濃度が7倍以下になったら8倍以上（望ましくは10倍以上）、銅イオンモル濃度に対する酒石酸モル濃度が6倍以下(望ましくは5倍以下)になるようにそれぞれを補給することが必要となる。
【００５４】
本発明は、銅イオン、銅イオンの錯化剤、還元剤及びｐH調整剤を含む銅めっき液を収納するめっき槽中に被めっき材を浸漬し、無電解銅めっきする無電解銅めっき装置において、前記還元剤がグリオキシル酸及びその塩で、その濃度が銅イオン濃度の8倍以上及び前記錯化剤が酒石酸又はその塩で、その濃度が銅イオン濃度の6倍以下になるように前記還元剤を補給する還元剤補給手段及び前記銅イオンを補給する銅イオン補給手段及び前記ｐH調整剤を補給するｐH補給手段を有すること、又、めっき槽中のめっき浴温度を所定の温度に制御する温度制御装置を特徴とする。
【００５５】
本発明は、めっき液及びめっき液補給方法（管理方法）によって銅めっきが施されるプリント基板を与える。プリント基板の基板素材としては、一般的にはガラスエポキシが使用されるが、本めっき液は、このガラスエポキシ以外においても、ポリイミド、ポリテトラフルオロエチレン等の有機物以外にもガラス、セラミックスなどにも適用することができる。
【００５６】
【発明の実施の形態】
本発明の実施形態に関しても、錯化剤にＥＤＴＡを使用した場合と酒石酸塩を使用した場合で挙動が異なるため、それぞれの錯化剤にわけて説明する。実施例１〜２２及び比較例１〜１１は錯化剤にＥＤＴＡを使用した場合を、実施例２３〜４３及び比較例１２〜２０は錯化剤に酒石酸塩を使用した場合である。
【００５７】
以下、錯化剤にＥＤＴＡを使用した場合の実施例及び比較例について説明する。比較例では、本発明を検討するのにあたり実験を行いスルーホール内が均一にめっきができなかった条件又はめっき液の安定性が得られなかった条件に関して示された結果を示している。
【００５８】
図１は本実施例及び比較例に用いた無電解銅めっき装置の断面図である。図１に示すように、めっき槽１にめっき液２が、硫酸銅補給ライン３、ＥＤＴＡ補給ライン４、グリオキシル酸補給ライン５、第１〜３種添加剤補給ライン６〜８よりめっきの経過と共に補給されながら被めっき材１２にめっきが施される。めっきの最中は、温度調節器によって所定の温度に調節されると共に、空気ポンプ１０によってめっき液中に空気が供給される。建浴されためっき液２は分槽ユニット１１に貯蔵されている。
【００５９】
（実施例１）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤として硫化カリウム 1.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 10ppm、第３種添加剤としてPEG1000 1.0ｇ/Ｌ ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００６０】
スルーホールを有する両面銅張り積層板をクリーナーコンディショナー（日立化成工業製 商品名：CLC-601）に浸漬した。次いで、過硫酸アンモニウム、硫酸を用いてソフトエッチングを行った後に、プリディップ（同商品名：PD-301）、増感処理剤（同商品名：HS-202B）、密着処理促進剤（同商品名：ADP-601）を用いて触媒処理した（以下上記工程を触媒処理と省略）。
【００６１】
前記した触媒処理、水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。
【００６２】
めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂上に樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.21μｍ/ｈであった。
【００６３】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００６４】
（実施例２）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤として硫化カリウム 1.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 1.0ｐｐｍ、第３種添加剤としてPEG1000 1.0ｇ/Ｌ ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００６５】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.25μｍ/ｈであった。
【００６６】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００６７】
（実施例３）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤として硫化カリウム 0.5.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 1.0ｐｐｍ、第３種添加剤としてPEG1000 1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００６８】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.32μｍ/ｈであった。
【００６９】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００７０】
（実施例４）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤として硫化カリウム 1.0ｐｐｍ、第２種添加剤としてメタバナジン酸ナトリウム 1.0ｐｐｍ、第３種添加剤として硫酸カリウム 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００７１】
触媒処理として以下の実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.24μｍ/ｈであった。
【００７２】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００７３】
（実施例５）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてチアゾール 5.0ｐｐｍ、第２種添加剤としてメタバナジン酸ナトリウム 1.0ｐｐｍ、第３種添加剤としてしゅう酸カリウム 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００７４】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.18μｍ/ｈであった。
【００７５】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００７６】
（実施例６）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.04M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてチアゾール 5.0ｐｐｍ、第２種添加剤としてメタバナジン酸ナトリウム 0.1.0ｐｐｍ、第３種添加剤としてグリコール酸 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００７７】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.06μｍ/ｈであった。
【００７８】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００７９】
（実施例７）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾイミダゾール 5.0ｐｐｍ、第２種添加剤としてメタケイ酸ナトリウム 0.5.0ｇ/Ｌ、第３種添加剤としてＰＥＧ1000 1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００８０】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.20μｍ/ｈであった。
【００８１】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００８２】
（実施例８）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾイミダゾール 5.0ｐｐｍ、第２種添加剤としてメタケイ酸ナトリウム 0.5.0ｇ/Ｌ、第３種添加剤としてＰＥＧ1000 1.0ｇ/Ｌ、ｐH（KOHで調整）：12.4
めっき液の温度は30℃に調整した。
【００８３】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂上のめっき速度は、0.88μｍ/ｈであった。
【００８４】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００８５】
（実施例９）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.1M 第１種添加剤としてベンゾイミダゾール 5.0ｐｐｍ、第２種添加剤としてメタケイ酸ナトリウム 0.5.0ｇ/Ｌ、第３種添加剤としてＰＥＧ1000 1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００８６】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.05μｍ/ｈであった。
【００８７】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００８８】
（実施例１０）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾチアゾール 5.0ｐｐｍ、第２種添加剤として二酸化ゲルマニウム 50ppm、第３種添加剤として硫酸カリウム 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００８９】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.62μｍ/ｈであった。
【００９０】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００９１】
（実施例１１）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾチアゾール 5.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 1.0ｐｐｍ、第３種添加剤として硫酸カリウム 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００９２】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.64μｍ/ｈであった。
【００９３】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００９４】
（実施例１２）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾチアゾール 5.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 1.0ｐｐｍ、第３種添加剤として硫酸カリウム 1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００９５】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.82μｍ/ｈであった。
【００９６】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【００９７】
（実施例１３）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾチアゾール 5.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 10ppm、第３種添加剤として硫酸カリウム 1.0ｇ/L、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【００９８】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.37μｍ/ｈであった。
【００９９】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１００】
（実施例１４）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.04M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.1M 第１種添加剤として硫化カリウム 0.1ｐｐｍ、第２種添加剤としてメタバナジン酸ナトリウム 1.0ppm、第３種添加剤として硫酸カリウム 1.0ｇ/L、ｐH（KOHで調整）：12.4
めっき液の温度は30℃に調整した。
【０１０１】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、0.52μｍ/ｈであった。
【０１０２】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１０３】
（実施例１５）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾトリアゾール 0.1ｐｐｍ、第２種添加剤としてスズ酸ナトリウム
10ppm、第３種添加剤としてPEG600 10ｇ/L、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１０４】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、0.84μｍ/ｈであった。
【０１０５】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１０６】
（実施例１６）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてメルカプトコハク酸 1.0ｐｐｍ、 第２種添加剤としてメタバナジン酸ナトリウム 0.1ｐｐｍ、第３種添加剤としてPEG600 10ｇ/L、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１０７】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.82μｍ/ｈであった。
【０１０８】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１０９】
（実施例１７）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤として硫化カリウム 0.05ｐｐｍ、 第２種添加剤としてメタバナジン酸ナトリウム 0.01ｐｐｍ、第３種添加剤として硫酸カリウム 10ｇ/L、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１１０】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.82μｍ/ｈであった。
【０１１１】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１１２】
（実施例１８）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤として硫化カリウム 0.5ｐｐｍ及びメルカプトコハク酸 0.5ｐｐｍ、第２種添加剤としてα、α´−ビピリジル 1.0ppm及びメタバナジン酸ナトリウム 0.1ｐｐｍ、第３種添加剤として硫酸カリウム 1.0ｇ/L及びPEG600 1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１１３】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、0.99μｍ/ｈであった。
【０１１４】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１１５】
（実施例１９）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてチアゾール 5.0ppm、 第２種添加剤としてメタバナジン酸ナトリウム 1.0ppm、第３種添加剤としてしゅう酸カリウム 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は45℃に調整した。
【０１１６】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.68μｍ/ｈであった。
【０１１７】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１１８】
（実施例２０）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてチアゾール 5.0ppm、 第２種添加剤としてメタバナジン酸ナトリウム 1.0ppm、第３種添加剤としてしゅう酸カリウム 5.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は25℃に調整した。
【０１１９】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.12μｍ/ｈであった。
【０１２０】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１２１】
（実施例２１）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてメルカプトコハク酸 1.0ppm、 第２種添加剤としてメタバナジン酸ナトリウム 0.1ｐｐｍ、第３種添加剤としてＰＥＧ600 0.1ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１２２】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.89μｍ/ｈであった。
【０１２３】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１２４】
（実施例２２）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてメルカプトコハク酸 1.0ppm、 第２種添加剤としてメタバナジン酸ナトリウム 0.1ｐｐｍ、第３種添加剤としてＰＥＧ600 10ｇ/L、ｐH（KOHで調整）：12.0
めっき液の温度は30℃に調整した。
【０１２５】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.63μｍ/ｈであった。
【０１２６】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１２７】
（比較例１）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、添加剤は無し、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１２８】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂上に析出した銅は暗褐色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、6.50μｍ/ｈであった。
【０１２９】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置すると、30分程度で分解反応が生じ、銅粒子が液中に浮遊した。
【０１３０】
（比較例２）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第２種添加剤としてα、α´−ビピリジル：10ppm、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１３１】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅はピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.45μｍ/ｈであった。
【０１３２】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。しかしこの液を放置すると、12時間後には分解反応が生じており、銅粒子が液中に浮遊していた。
【０１３３】
（比較例３）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第２種添加剤としてメタケイ酸ナトリウム：0.5.0ｇ/Ｌ、第３種添加剤としてPEG1000：1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１３４】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗褐色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.62μｍ/ｈであった。
【０１３５】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。しかしこの液を放置すると、12時間後には分解反応が生じており、銅粒子が液中に浮遊していた。
【０１３６】
（比較例４）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第２種添加剤としてα、α´-ビピリジル：10ppm、 第３種添加剤としてPEG1000：1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１３７】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅はピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.59μｍ/ｈであった。
【０１３８】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。しかしこの液を放置すると、12時間後には分解反応が生じており、銅粒子が液中に浮遊していた。
【０１３９】
（比較例５）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第１種添加剤として硫化カリウム：1.0ｐｐｍ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１４０】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗褐色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、5.8μｍ/ｈであった。
【０１４１】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１４２】
（比較例６）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第１種添加剤としてベンゾイミダゾール：50ppm、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１４３】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗褐色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、4.21μｍ/ｈであった。
【０１４４】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１４５】
（比較例７）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第１種添加剤としてベンゾイミダゾール：1.0ｇ/Ｌ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１４６】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗褐色で密着性は有るが、めっきされている部分とそうでない部分があり、均一にめっきされていなかった。めっき速度は、一様にめっきされているものとしてめっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、0.5μｍ/ｈ以下であった。
【０１４７】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１４８】
（比較例８）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第１種添加剤としてベンゾチアゾール：5.0ｐｐｍ、第２種添加剤としてα、α´−ビピリジル：1.0ｐｐｍ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１４９】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、2.52μｍ/ｈであった。
【０１５０】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１５１】
（比較例９）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、ＥＤＴＡ-4Ｈ：0.12M、グリオキシル酸：0.3M 第１種添加剤としてベンゾチアゾール 5.0ｐｐｍ、 第２種添加剤としてα、α´―ビピリジル 10ppm、第３種添加剤 無し、ｐH（KOHで調整）：12.4
めっき液の温度は30℃に調整した。
【０１５２】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、1.43μｍ/ｈであった。
【０１５３】
スルーホール内のめっきの状況は、バックライト試験により評価した。全て暗視野であり、欠陥のない均一なめっき膜が得られたことが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１５４】
（比較例１０）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第１種添加剤として硫化カリウム：1.0ｐｐｍ、第２種添加剤としてメタバナジン酸ナトリウム：0.05ｐｐｍ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１５５】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗褐色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、3.42μｍ/ｈであった。
【０１５６】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置しても、銅の析出は確認できなかった。
【０１５７】
（比較例１１）
下記の組成のめっき液を4.5L調整した。
硫酸銅：0.06M、EDTA：0.12M、グリオキシル酸：0.3M、第１種添加剤として硫化カリウム：0.05ｐｐｍ、第２種添加剤としてメタバナジン酸ナトリウム：0.01ｐｐｍ、ｐH（KOHで調整）：12.8
めっき液の温度は30℃に調整した。
【０１５８】
触媒処理として実施例1に示した操作を行った。水洗後、上記の条件に調整しためっき液中に20分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。めっき液に浸漬後、ガス放出に伴いめっき反応が直ちに開始した。樹脂板上に析出した銅は暗褐色で密着性があり、エッジ部分を含めて一面に均一に析出していた。めっき速度は、めっき前後の樹脂板の重量差及び比重を用いて求めた。このめっき液中における樹脂板上のめっき速度は、4.22μｍ/ｈであった。
【０１５９】
スルーホール内のめっきの状況は、バックライト試験により評価した。光の透過部が、特にガラスクロスの部分に多くみられ、欠陥を有する不均一なめっき膜であることが確認できた。この液を放置しても、銅の析出は確認できなかった。
実施例１〜２２及び比較例１〜１１の結果を、表１及び２にまとめて示す。
【０１６０】
【表１】

【０１６１】
【表２】

【０１６２】
実施例１〜２２及び比較例１〜１１に示すように、樹脂板上におけるめっき速度が0.5〜2.0μｍ/ｈの間にある場合、添加剤の種類、その濃度に依存せずスルーホール内が均一にめっきされていることがわかる。
【０１６３】
しかし、前述したように添加剤の濃度は連続的にめっきすることによりそれぞれの濃度が減少するために、例えば比較例９に示すように、第３種添加剤が無い場合においても、樹脂板上におけるめっき速度が0.05〜2.0μm/h内であればスルーホール内は均一にめっきされるが、連続的なめっきにより比較例８に示すように速度調整として使用している第２種添加剤であるビピリジル濃度が減少すると、めっき速度が適正範囲を超えるためにスルーホール内は均一にめっきできなくなる。しかし、この条件においても実施例１１や１２に示されるように第３種添加剤が添加されている場合は、めっき速度は適正範囲内であり、スルーホール内は均一にめっきされる。
【０１６４】
またたとえば実施例１及び実施例２、実施例１２及び１３に示すように、第２種添加剤の濃度が変化した場合においても、第３種添加剤が添加されていることによりめっき速度はほとんど変化せず、スルーホール内は均一にめっきすることができる。さらにたとえば実施例１１及び１２に示すように、第1種添加剤及び第２種添加剤の種類及び濃度が同じである場合、第３種添加剤の濃度が変化してもめっき速度はほとんど変化せず、スルーホール内は均一にめっきすることができる。
【０１６５】
実施例１４に示すように、硫酸銅濃度、グリオキシル酸濃度及びｐHが低下した場合においても、第１種添加剤、第２種添加剤及び第３種添加剤がある場合は、めっき速度は適正範囲内である。比較例１１に示すように、第１種添加剤及び第２種添加剤の濃度が極端に低下した場合、めっき速度は適正範囲を超えスルーホール内は均一にめっきすることができなくなるが、実施例１７に示すように第３種添加剤が存在することによりめっき速度は適正範囲内に入り、スルーホール内は均一にめっきすることができる。
【０１６６】
実施例１８に示すように第1種添加剤、第２種添加剤及び第３種添加剤において、それぞれにおいて複数の種類の添加剤を用いても１種類ずつ用いた場合と同様の効果が見られる。
【０１６７】
実施例１９及び２０に示すように温度が２５又は４５℃のように比較的高い場合と、比較的低い場合においても３０℃の場合と同様の効果が見られる。ただし５０℃以上の場合においては、グリオキシル酸の分解反応による減少量が多く、実用的ではなかった。
【０１６８】
実施例２１に見られるように、第３種添加剤としてＰＥＧ600を0.1ｇ/Ｌ添加した場合では、実施例１６に示されるようにＰＥＧ600を10ｇ/Ｌ添加した場合と同様の効果が見られた。しかし、第３種添加剤の量が極端に少ない場合は、前述したように基板の出し入れによる消耗により濃度が極端に低下するとその効果が小さくなるので、望ましくは1.0ｇ/Ｌ以上必要である。
実施例２２に示されるようにｐＨ12.0においても12.8の場合と同様の効果が見られる。
【０１６９】
第１種添加剤、第２種添加剤及び第３種添加剤として上記例示したものであれば、どの化合物の組み合わせでも、上記実施例には示したものと同様の効果を得ることができる。
【０１７０】
次に、錯化剤に酒石酸塩を使用した場合の実施例２３〜４３及び比較例１２〜２０について説明する。
【０１７１】
比較例１２〜２０では、本発明を検討するのにあたり実験を行ったがめっきができなかった条件、及び従来技術に示された条件での結果を示している。実施例２３〜４３及び比較例１２〜２０では、表３に示される無電解銅めっき液組成を用いた。
【０１７２】
【表３】

【０１７３】
表３には、硫酸銅、酒石酸ナトリウムカリウム、グリオキシル酸、ｐH、ＰＥＧ1000、２、２’−ビピリジル、酒石酸塩と硫酸銅とのモル比率、グリオキシル酸と硫酸銅とのモル比率、めっき液温度が示されている。ｐH調整としてKOHを用いた。めっき液は総て4.5L調整したものである。
【０１７４】
更に、表３に触媒処理した銅の電位が示されている。本実施例においては、浸漬直後においては-100ｍＶ程度であったが、1分以内に低下した値を同様に示した。本実施例においては、めっき液温度が25℃の場合で、いずれもE=0.471-0.0001984×T×pHの条件を満たすものであった。比較例１２、１４、１８においては浸漬直後における値を示し、比較例１５、１７、２０においては１０分後の値を示し、いずれもその条件を満たさなかった。
【０１７５】
本実施例２３〜４３及び比較例１２〜２０に使用した装置は、図1に示したものと同様である。ただし、ＥＤＴＡ補給ライン４の代わりに酒石酸補給ラインとなる。
【０１７６】
（実施例２３）
スルーホールを有する両面銅張り積層板をクリーナーコンディショナー（日立化成工業製 商品名：CLC-601）に浸漬した。次いで、過硫酸アンモニウム、硫酸を用いてソフトエッチングを行った後に、プリディップ（同商品名：PD-301）、増感処理剤（同商品名：HS-202B）、密着処理促進剤（同商品名：ADP-601）を用いて触媒処理した（以下上記工程を触媒処理と省略）。水洗後、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。このめっき液中におけるめっき速度は、スルーホールを有する両面銅張り積層板のめっき前後の重量差から、密度を用いて時間当たりの厚さに換算（μｍ/ｈ）して求めた。
【０１７７】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、1.2μｍ/ｈであった。容器の底には、極わずかな銅の析出が見られた。
【０１７８】
（実施例２４）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１７９】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、4.0μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１８０】
（実施例２５）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１８１】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、2.2μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１８２】
（実施例２６）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１８３】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、2.0μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１８４】
（実施例２７）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.3L/min/L（めっき液）の条件で空気撹拌を行った。
【０１８５】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、5.0μｍ/ｈであった。容器の底に若干の銅の析出が見られた。
【０１８６】
（実施例２８）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.3L/min/L（めっき液）の条件で空気撹拌を行った。
【０１８７】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、5.4μｍ/ｈであった。容器の底にかなり多くの銅の析出が見られた。
【０１８８】
（実施例２９）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１８９】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、3.5μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１９０】
（実施例３０）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１９１】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、2.1μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１９２】
（実施例３１）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１９３】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、1.2μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１９４】
（実施例３２）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１９５】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、3.6μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１９６】
（実施例３３）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１９７】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、3.2μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０１９８】
（実施例３４）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０１９９】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、1.4μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２００】
（実施例３５）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２０１】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、3.6μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２０２】
（実施例３６）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２０３】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は濃いレンガ色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、2.8μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２０４】
（実施例３７）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２０５】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、3.6μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２０６】
（実施例３８）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２０７】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、4.3μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２０８】
（実施例３９）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２０９】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、3.8μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２１０】
（実施例４０）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２１１】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、0.95μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２１２】
（実施例４１）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２１３】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、1.2μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２１４】
（実施例４２）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２１５】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、2.8μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２１６】
（実施例４３）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２１７】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色で密着性があり、エッジ部分を含めて一面に均一に析出していた。このめっき液中におけるめっき速度は、2.6μｍ/ｈであった。容器の底に銅の析出は見られなかった。
【０２１８】
（比較例１２）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
【０２１９】
触媒処理した積層板をめっき液に浸漬しても、めっき反応は全く生じず、基板上に銅の析出は確認できなかった。容器の底には、銅の析出が見られた。
触媒処理した銅の電位は、浸漬直後においては-120ｍＶ以上でありE=0.471-0.0001984×T×pHの条件を満たさなかった。
【０２２０】
（比較例１３）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.4L/min/L（めっき液）の条件で空気撹拌を行った。
【０２２１】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色であるが、密着性は乏しかった。めっきはむらがあり、めっきできている部分とそうでない部分とが存在した。均一にめっきされていないために、めっき速度を求めることはできなかった。めっき開始後、数分後には銅粒子がめっき槽内を浮遊し、容器の底には大量の銅の析出が見られた。
【０２２２】
（比較例１４）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
触媒処理した積層板をめっき液に浸漬しても、めっき反応は全く生じず、基板上に銅の析出は確認できなかった。容器の底には、銅の析出が見られた。
【０２２３】
（比較例１５）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.4L/min/L（めっき液）の条件で空気撹拌を行った。
【０２２４】
めっき液に浸漬5分以降、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色であるが、密着性は乏しかった。めっきはむらがあり、めっきできている部分とそうでない部分とが存在した。均一にめっきされていないが、平均的にめっきされていると仮定した場合のこのめっき液中におけるめっき速度は、0.5μｍ/ｈであった。
触媒処理した銅の電位は、浸漬直後においては-100ｍＶ程度であったが、その後電位は低下して、-280ｍＶ以下になりE=0.471-0.0001984×T×pHの条件を満たしたものの、それに達するまでに１０分以上の時間を要した。
【０２２５】
（比較例１６）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.4L/min/L（めっき液）の条件で空気撹拌を行った。
触媒処理した積層板をめっき液に浸漬しても、めっき反応は全く生じず、基板上に銅の析出は確認できなかった。容器の底には、銅の析出が見られた。
【０２２６】
（比較例１７）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
触媒処理した積層板をめっき液に浸漬しても、めっき反応は全く生じず、基板上に銅の析出は確認できなかった。容器の底には、銅の析出が見られた。
【０２２７】
（比較例１８）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.2L/min/L（めっき液）の条件で空気撹拌を行った。
触媒処理した積層板をめっき液に浸漬しても、めっき反応は全く生じず、基板上に銅の析出は確認できなかった。容器の底には、銅の析出が見られた。
【０２２８】
（比較例１９）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.4L/min/L（めっき液）の条件で空気撹拌を行った。
【０２２９】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色であるが、密着性は乏しかった。めっきはむらがあり、めっきできている部分とそうでない部分とが存在した。均一にめっきされていないが、平均的にめっきされていると仮定した場合のこのめっき液中におけるめっき速度は、0.34μｍ/ｈであった。
【０２３０】
（比較例２０）
スルーホールを有する両面銅張り積層板を触媒処理した後に、上記の条件に調整しためっき液中に15分間浸漬させた。めっき浴負荷は1ｄｍ²/Lになるように基板の面積を調整した。めっき中は常にめっき液を0.4L/min/L（めっき液）の条件で空気撹拌を行った。
【０２３１】
めっき液に浸漬後、ガス放出に伴いめっき反応が開始した。析出した銅は暗ピンク色であるが、密着性は乏しかった。めっきはむらがあり、めっきできている部分とそうでない部分とが存在した。均一にめっきされていないが、平均的にめっきされていると仮定した場合のこのめっき液中におけるめっき速度は、0.42μｍ/ｈであった。
触媒処理した銅の電位は、浸漬直後においては-100ｍＶ程度であったが、その後電位は低下して、-280ｍＶ以下になりE=0.471-0.0001984×T×pHの条件を満たしたものの、それに達するまでに１０分以上の時間を要した。
【０２３２】
図２は、上記実施例２３〜４３と比較例１２〜２０において、めっき液温度が25℃においての酒石酸塩モル濃度/硫酸銅モル濃度とグリオキシル酸モル濃度/硫酸銅モル濃度をパラメータとした場合のめっきの可否を示したものである。これより均一なめっき可能な条件は、酒石酸塩モル濃度/銅モル濃度が6以下でかつ、グリオキシル酸モル濃度/銅モル濃度が8.0以上、好ましくは8.3以上であることが分かる。また均一なめっきが可能な条件においては、触媒処理した銅の電位が、浸漬直後においては-100ｍＶ程度であっても、1分以内に低下して、-280ｍＶ以下になりE=0.471-0.0001984×T×pHの条件を満たしていた。
【０２３３】
(実施例４４)
図３は、酒石酸塩(ロッセル塩)濃度をO.089M、グリオキシル酸濃度を0.26Mに固定し、銅濃度を変化させた場合の樹脂上におけるめっき速度を示している。硫酸銅濃度がO.06Mではめっき速度が遅く均一にめっきすることができない。銅濃度が0.06Mの場合の酒石酸塩/硫酸銅濃度比は1.48、グリオキシル酸濃度/硫酸銅濃度比は4.3である。硫酸銅濃度が0.03M以下になるとめっき速度が上昇し、めっきが均一にできるようになる。銅濃度が0.03Mの場合の酒石酸/硫酸銅濃度比は2.96、グリオキシル酸濃度/硫酸銅濃度比は8.7である。硫酸銅濃度が砥下すると、0．018Mで最大の速度を示した後、めっき速度は減少する。硫酸銅濃度が0.006Mになると完全に均一性に欠けためっきとなる。銅濃度が0.006Mの場合の酒石酸塩/硫酸銅濃度比は14.83、グリオキシル酸濃度/硫酸銅濃度比は43.3である。
【０２３４】
図４は、酒石酸濃度が0．089Mの場合において、種々の濃度の硫酸銅及びグリオキシル酸の場合における銅の分極曲線を示している。電流0を横切る電位が、めっき電位である。めっきが不均一である硫酸銅O.06M、グリオキシル酸0.26Mにおいては、電位は−480mV(vs.Ag/AgC1)であり、（−280 mV vs.SHE)、酸化銅が生成する領域である。それ以外の場合では、電位は.480mV(vs.Ag/AgCl)以下であり、銅が生成する領域になり、めっきすることができる。
【０２３５】
（実施例４５）
本実施例では、基板のめっきを連続的に実施した場合について述べる。基板は、触媒処理、水洗工程を経た後にめっき浴槽に入るため、水に濡れた状態でめっき槽に入る。基板はめっき後水洗槽に入るため、めっき液がついた状態でめっき槽から出て行く。そのため前述したようにめっき反応及び副反応以外にも、連続的にめっきする場合は本操作により銅イオン濃度、グリオキシル酸濃度は時間とともに減少する。酒石酸塩の濃度は、副反応により減少することはないが、本操作により濃度は減少する。
【０２３６】
【表４】

【０２３７】
表４は、各時間において測定した銅イオンモル濃度、グリオキシル酸モル濃度、酒石酸塩モル濃度、ｐH及び酒石酸塩モル濃度/銅イオンモル濃度、グリオキシル酸モル濃度/銅イオンモル濃度の時間変化を示している。時間とともに、銅イオンモル濃度、グリオキシル酸モル濃度、酒石酸塩モル濃度、ｐH、酒石酸塩モル濃度/銅イオンモル濃度、グリオキシル酸モル濃度/銅イオンモル濃度が減少している。３時間後においてはグリオキシル酸モル濃度/銅イオンモル濃度の比が8.1になり、また銅イオン濃度、グリオキシル酸濃度、酒石酸濃度、ｐHが減少したため、グリオキシル酸モル濃度/銅イオンモル濃度の比が10以上になるように硫酸銅、グリオキシル酸、酒石酸塩、アルカリを添加し、めっきを続けた。
【０２３８】
５時間後において、グリオキシル酸モル濃度/銅イオンモル濃度の比が8.3以下になりめっきにむらが生じるようになった。さらに銅イオン濃度、グリオキシル酸濃度、酒石酸濃度、ｐHが減少したため、再びグリオキシル酸モル濃度/銅イオンモル濃度の比が10以上になるように硫酸銅、グリオキシル酸、酒石酸塩、アルカリを添加し、めっきを続けた。
【０２３９】
７時間後においても同様の処理を行った。８時間めっきを行った後に、めっき液を空気バブリングした状態で翌日まで保持した。めっき浴内での銅粒子の析出はみられなかった。
【０２４０】
２４時間後、めっき液を分析すると、グリオキシル酸モル濃度/銅イオンモル濃度の比が5.3になり、また銅イオン濃度、グリオキシル酸濃度、ｐHが減少したため、めっきを行う前にグリオキシル酸モル濃度/銅イオンモル濃度の比が10以上になるように硫酸銅、グリオキシル酸、酒石酸塩、アルカリを添加し、めっきした。めっき中の銅の電位は、常に-250ｍV以下であり、E₀=0.471-0.0001984×T×pHの式で表される電位領域であった。
【０２４１】
表４に示す様に、グリオキシル酸モル濃度/銅イオンモル濃度の比が6倍に低下した時点でグリオキシル酸を（グリオキシル酸モル濃度/銅イオン）モル濃度の比が15倍以上になるように約２時間毎に加えることによってその後も長時間に亘って安定して均一な銅めっきが得られることが明らかとなった。
【０２４２】
【発明の効果】
グリオキシル酸を還元剤としためっき液を使用することにより、人体及び環境への負荷を軽減することができる。また、錯化剤にＥＤＴＡを使用した場合、そのめっき液を使用するにあたり、液安定性用第１種添加剤、速度調整用第２種添加剤及び第２種添加剤の濃度が変化した場合においても速度が変化しない速度緩衝作用を持つ第３種添加剤を加えることにより安定で連続めっきによる添加剤の濃度変化にかかわらず均一なめっきを行うことができる。更に、錯化剤に酒石酸塩を使用した場合、そのめっき液を使用するにあたり、めっき液の組成比を制御することにより長期に亘って安定して均一な銅めっきを得ることができる無電解銅めっき液とその方法及び装置を提供できるものである。
【図面の簡単な説明】
【図１】本発明の実施例で用いる無電解銅めっき装置の断面図である。
【図２】酒石酸塩モル濃度/硫酸銅モル濃度とグリオキシル酸モル濃度/硫酸銅モル濃度をパラメータとしためっきの可否を示す図である。
【図３】樹脂板上への銅めっき速度と銅濃度との関係を示す線図である。
【図４】銅及びグリオキシル酸（ＧＯＡ）を含むロッセル塩水溶液中の銅の分極を示す電流密度と電位を示す線図である。
【符号の説明】
１…めっき槽、２…めっき液、３…硫酸銅補給ライン、４…ＥＤＴＡ補給ライン、５…グリオキシル酸補給ライン、６〜８…第１〜３種添加剤補給ライン、９…温度調節器、１０…空気ポンプ、１１…分槽ユニット、１２…被めっき材。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel electroless copper plating solution, an electroless copper plating solution management method, and an electroless copper plating apparatus used for wiring formation of a printed wiring board.
[0002]
[Prior art]
Electroless copper plating solutions are often used for imparting electrical conductivity to non-metallic materials such as plastics and resins, and are widely used for producing electronic parts such as printed wiring boards. The electroless copper plating solution is composed of copper ions, a complexing agent for copper ions, a reducing agent for copper ions, a pH adjusting agent, and a trace additive such as a surfactant for improving the stability of the solution. Among them, formaldehyde is a reducing agent that is industrially put into practical use. However, in recent years, it has been pointed out that formaldehyde has a high vaporization property and has an odor or the like, which deteriorates the working environment, and the use of an alternative reducing agent is widely desired.
[0003]
Examples of reducing agents other than formaldehyde include JP-A-11-256349, JP-A-8-246159, JP-B-2-24910, “Surface Technology” Vol.42, No.9, 1991, p.913-p.917. “Electroless copper plating using glyoxylic acid as reducing agent” and “Journal of Circuit Packaging Society”, vol.10 [2] 1995 p.118-p.122 “Deposition of electroless copper plating using glyoxylic acid as reducing agent” Using glyoxylic acid described in `` Process '' etc., U.S. Pat. Nos. 4209331, 4325990, J. Electrochem. Soc., Vol.136, No.1 (1989) p.72-p.75 `` Mechanism of Known are those using hypophosphites described in `` Hypophosphite-Reduced Electroless Copper Plating '', etc., and those using amine compounds as described in JP-A-2-305971 and JP-A-1-80986. It has been.
[0004]
As will be described later, in the plating solution, copper precipitates in the solution due to the formation of copper oxide and the self-decomposition reaction of copper oxide, and the stability of the bath decreases. Conventionally, in electroless copper plating using formaldehyde as a reducing agent, various additives have been added to suppress such copper precipitation reaction. In particular, in the case of thickening (high temperature) plating, the mechanical properties of the plating film are regarded as important, and various additives are added for the purpose of improving the spreadability and bendability. Further, when both characteristics are required, additives having respective roles are combined.
[0005]
Examples of the stabilizer for suppressing copper deposition (plating solution stability) include 2,2′-bipyridyl, dithizone, imidazole, 1, 2 shown in “Surface Technology Handbook (p. 336)”. 4-benzotriazole, nicotinic acid, thiourea, 2-mercaptobenzothiazole, sodium cyanide, cupron and the like, and 5-membered heterocyclics as described in JP-B 43-12966, 6-membered heterocyclics, organic sulfur compounds such as thio derivatives, potassium sulfide, those added with inorganic sulfur compounds such as alkali metal dithionates, bipyridyl and cyclic structures only as described in JP-A-8-246159 Examples thereof include compounds containing S, thioglycolic acid and diphenylcarbazone described in JP-A-5-78853.
[0006]
Additives for improving mechanical properties include those using polyalkylene oxide as described in USP-3804638, those using dipyridyl as described in USP-4002786, In addition to dipyridyl and polyethylene glycol described in 54-19430, there are those to which silicates such as sodium silicate are added.
[0007]
In addition, when the effects of both, that is, the mechanical properties are improved and the plating solution stability is brought about, additives exhibiting the respective effects are used in combination. For example, as described in JP-A-53-51143, bipyridyl is used as an additive for improving mechanical properties, and a polyethylene glycol alkylamine nonionic interface is used as an additive for improving mechanical properties and preventing copper oxide formation. An active agent and a combination of silver sulfides as additives for the purpose of improving liquid stability, described in JP-A-1-263278 (1) polyalkylene glycol (2) bipyridyl, phenanthroline, diquinolyl (3) Adding selenate for the purpose of improving the stability of liquids and liquids, as described in JP-A-6-93457, mercaptosuccinic acid or further bipyridyl for the purpose of improving liquid stability and adhesion Sodium metavanadate, sodium germanate, 8-azaguanine, 8-azaxanthine, 8-azahypoxanthine, adeni , 8-azaadenine, guanine, hypoxanthine added, polyethylene glycol and liquid stability to improve spreadability as described in JP-A-51-78744 and JP-A-52-78744 In addition to the addition of metal sulfides such as potassium sulfide for the purpose of improving the properties, bipyridyl for the purpose of improving the elongation and polyalkylene for the purpose of improving the liquid stability as described in JP-A-51-105932. Some of them are added, and as described in JP-A-59-166669, polyoxyalkylene glycol and vanadium or a vanadium compound are added for the purpose of improving liquid properties for the purpose of liquid stability.
[0008]
In order to perform more uniform plating, it is important to adjust to a certain plating rate. Examples of those added as a plating rate adjusting agent include those containing thiourea, allyl thiourea, thiomalic acid, thioglycolic acid, thiocyanic acid and salts thereof described in JP-A-11-256349, Other than vanadium or vanadium compounds described in -37971, bipyridyl and phenanthroline are added for the purpose of improving spreadability.
[0009]
As the plating reaction proceeds, the by-product produced changes the plating characteristics, particularly mechanical properties. For this reason, as described in JP-A-61-223185, formate ions and carbonate ions, which are formed when formaldehyde is used as a reducing agent, are added in advance.
[0010]
[Problems to be solved by the invention]
As reducing agents other than formaldehyde, as described above, amine compounds represented by glyoxylic acid, sodium hypophosphite, dimethylamine borane and the like are known. When sodium hypophosphite is used, nickel sulfate coexists in order to allow the plating reaction to proceed in a self-catalytic manner, so that there is a problem in that nickel is co-deposited in the plating film and the film properties are lowered. . Moreover, the plating solution using dimethylamine borane as a reducing agent has a problem that the liquid stability is low.
[0011]
In using the electroless copper plating solution, the copper ion concentration and the reducing agent concentration decrease as the plating reaction proceeds. When aldehydes are used as the reducing agent, the reducing agent concentration is also reduced by the Cannizzaro-reaction, which is a self-decomposing reaction of the reducing agent. In addition, since the hydroxide ions in the aqueous solution are consumed by the plating reaction and the Cannizzaro reaction, the pH decreases with time.
[0012]
The following shows the plating reaction and the Cannizzaro reaction when formaldehyde or glyoxylic acid is used as the reducing agent.
[0013]
[Chemical 1]

[0014]
In addition to these reactions, copper in the solution precipitates in the plating solution due to the formation of copper oxide and the self-decomposition reaction of copper oxide as shown below, and the stability of the bath is significantly reduced.
[0015]
[Chemical 2]

[0016]
Thus, the plating composition is not always constant, and the composition changes every moment. In order to perform plating stably, the stability of the bath should be improved, that is, the Kanitz allo reaction, which is a side reaction, should be suppressed (reduction of the reducing agent concentration only by the plating reaction), the formation and oxidation of copper oxide. It is necessary to suppress the self-decomposition reaction of copper (only decrease the copper ion concentration by plating reaction) and keep the reducing agent concentration and copper ion concentration constant. In order to suppress the formation of copper oxide and the self-decomposition reaction of copper oxide, it is necessary to stabilize monovalent copper, and air agitation of a plating solution and a stabilizer are added.
[0017]
When formaldehyde is used as a reducing agent, cyanide compounds, bipyridyl, O-phenanthroline, thiourea, etc. that preferentially bind to monovalent copper to form a complex are used as additives for stabilization. . Moreover, although normally used under high alkali conditions, the complexing agent which reduces the density | concentration of the free copper ion so that copper ion may not precipitate also in such conditions is used. Industrially, Roselle salt, EDTA, etc. are used, and a certain level of concentration is required for stabilization.
[0018]
As an example of using glyoxylic acid as a reducing agent and tartrate as a complexing agent, JP-B-2-24910 discloses that the concentration of the copper ion source is 0.0078 to 0.63 mol, and the tartrate is the molar concentration of copper ions. Further, it is described that the effective molar concentration of the glyoxylate ion source is 0.01 to 1.5 mol, specifically, 2.13 times the molar concentration of copper ions.
[0019]
It is effective to use KOH rather than NaOH as a pH adjuster in order to suppress the Kanitz Allo reaction and suppress the decrease in the concentration of aldehyde-based reducing agent. “Surface technology vol.42, No.9, 913-917 (1991) "and" 6th Academic Lecture Conference Proceedings 101-102 ". Japanese Patent Laid-Open No. 2000-144438 describes that methanol is added to the plating solution, but this method does not suppress the Kanitz-Allo reaction itself, so that the effect has a certain limit. Yes.
[0020]
However, when glyoxylic acid is used as a reducing agent for the electroless copper plating solution, the Kanitz allo reaction proceeds at a higher rate than when formaldehyde is used. Further, the amount of decrease in the copper ion concentration due to the self-decomposition reaction of copper oxide is large, and it is difficult to stabilize the plating bath as compared with formaldehyde. Accordingly, the reducing agent concentration, the copper ion concentration, and the pH (hydrogen ion concentration), which are the main components of the plating solution, always change.
[0021]
As a liquid composition in the case of using glyoxylic acid as a reducing agent, in each of Japanese Patent Publication No. 2-24910, each region is shown alone as described above. Since the reducing agent concentration, copper concentration, and temperature parameters interact with each other, there is a possibility that the plating reaction cannot be caused if the concentration of each parameter is regulated independently.
[0022]
In addition, when the pH, the reducing agent concentration, and the copper concentration change as the plating reaction proceeds, the plating conditions may be removed from these regions, and the plating reaction may not proceed stably. When glyoxylic acid is used as a reducing agent as described above, the cannizzaro reaction and copper autolysis reaction are more likely to occur than when formaldehyde is used. However, as the plating proceeds, the composition of the plating bath tends to deviate from the conditions under which plating can be performed.
[0023]
Furthermore, when the type of complexing agent is changed, it is described in the Journal of Circuit Packaging Society, vol.10 [2] 1995 p.118-p.122 “Deposition process of electroless copper plating using glyoxylic acid as a reducing agent”. As shown, when the plating reactivity is changed and the concentration of glyoxylic acid is 0.25M, when 0.06M tartaric acid is used, it takes about 10 minutes to start the plating reaction. Usually, the plating time is about 15 to 20 minutes, so when tartrate is used as the complexing agent, Journal of Circuit Packaging Society, vol.10 [2] 1995 p.118-p.122 “glyoxylic acid Under the conditions described in “Deposition Process of Electroless Copper Plating as Reducing Agent”, the actual plating time is within 5 to 10 minutes, and a sufficient plating thickness cannot be obtained. In addition, when 0.06M EDTA is used as the complexing agent, the plating reaction starts in a few seconds. Accordingly, the plating reactivity varies depending on the type of complexing agent, and when tartrate is used as the complexing agent, there arises a problem of how fast the plating reaction start time is.
[0024]
In the present invention, it is intended for low-temperature thinning. What is important is that the plating solution is stable without causing a decomposition reaction, and that the plating is uniform and is always in the same state even when the composition of the plating changes to some extent.
[0025]
However, in the study of the stabilizers described above, many have been studied when the reducing agent is formaldehyde and the like, and when glyoxylic acid is used as the reducing agent, there are substances that cannot always obtain the stability by addition. ing. For example, when glyoxylic acid is used as the reducing agent and EDTA is used as the complexing agent, stabilization of copper ions could not be achieved even when 20 ppm of bipyridyl was added. Furthermore, even if these additives are effective in improving the stability of copper ions, the copper precipitation reaction is often suppressed at the same time. In particular, when glyoxylic acid is used as the reducing agent, the rate of inhibition does not change in direct proportion to the concentration of the stabilizer added, and it is difficult to control the speed. May stop suddenly and completely. In order to improve this, a method of adding a speed regulator together is also considered. However, particularly in the case of thinning plating, the number of times the substrate is taken in and out and the plating solution is frequently replenished, so that the composition of the plating solution is not constant and constantly fluctuates. Accordingly, the plating rate always varies, and the same applies when the above-described plating rate adjusting agent is used. Since plating is usually performed for a certain period of time, the inside of the through-hole is not sufficiently plated, especially when the plating rate changes (in either case, the plating rate increases or decreases as described later) This causes the swelling of the copper film produced by the subsequent electroplating and the poor adhesion to the inner wall of the through hole.
[0026]
The purpose of the present invention is to reduce the influence on the human body and the environment by using a copper plating solution containing glyoxylic acid as a reducing agent, and to perform stable and uniform plating over a long period of time. The present invention provides an electroless copper plating solution, a liquid management method, and an apparatus thereof.
[0027]
[Means for Solving the Problems]
This invention exists in the electroless copper plating solution which does not use formaldehyde, and exists in the specific plating solution composition which contains at least glyoxylic acid as a reducing agent especially. When glyoxylic acid is used as the reducing agent, the copper plating reaction is caused to continue (continuously stable plating), and in order to maintain the stability of the plating solution, the reducing agent concentration, pH, copper ion There is a need to control the concentration, complexing agent concentration, and temperature within a certain concentration range, and to control the concentration of the additive. As described above, when the complexing agent is changed, the plating behavior is different even if the reducing agent is the same. In particular, when tartrate is used, the behavior is significantly different from that when other complexing agents are used. Therefore, here, the solution will be described separately for EDTA and tartrate as representatives of complexing agents.
[0028]
First, the case where glyoxylic acid is used as a reducing agent and ethylenediaminetetratetraacetic acid (EDTA) is used as a complexing agent in the present invention will be described. The composition of the plating solution in the present invention includes various additives in addition to a copper salt, a cupric ion complexing agent, a reducing agent, and a pH adjusting agent.
[0029]
The additives are as follows. In the case of using glyoxylic acid as a reducing agent, after performing electroless copper plating in combination with a plurality of additives showing various plating inhibitory effects and additives showing plating stability, the results of observing the plating situation in the through hole, It was found that the condition for uniformly plating the inside of the through hole was when the additive was added so that the plating rate on the resin plate was 0.5 to 2.0 μm / h, regardless of the type of additive. It is natural that when the plating speed is slow, the plating cannot be performed and becomes non-uniform, but conversely, when the plating speed is fast, the plating reaction proceeds on the surface of the copper-clad laminate. Further, it is considered that the amount of copper ions diffusing into the through hole is reduced, and the copper concentration in the through hole is lowered.
[0030]
Although the copper ion stabilizer shown in the section of the prior art provides sufficient copper ion stability even at several ppm, the plating rate on the resin plate is adjusted to 0.5 to 2.0 μm / h using this stabilizer. The concentration that must be added to the solution must be at least 10 ppm or more. However, as described above, when these additives are added up to several tens of ppm, the fluctuation of the plating rate with respect to the concentration change is large, and the plating reaction is often stopped abruptly.
[0031]
In addition, it is conceivable that the concentration of the additive that stabilizes the plating solution as the first type additive is suppressed to a low level, and a speed adjusting agent is further added as the second type additive. However, in the case of continuous plating, in addition to the plating reaction, the copper ions can be taken in and out of the substrate (the substrate enters the plating tank wet with water and leaves the plating tank with the plating solution attached). The concentration, the reducing agent concentration, the alkali concentration, the first type additive concentration, the second type additive concentration, and the like change (decrease). The second type additive adjusts the speed by its addition (the second type additive has a plating rate that changes in direct proportion to its concentration), but its concentration changes by continuous plating. For this reason, there is a possibility that the inside of the through hole may not be uniformly plated because the plating speed does not enter between 0.5 to 2.0 μm / h.
[0032]
In order to improve these, as the third type additive, even if the concentration of the second type additive as its own concentration and rate adjusting agent changes, the change in the plating rate is small, that is, it has a rate buffering property. This object can be achieved by combining additives.
[0033]
What is important here is that the effect of copper ion stability, which is the purpose of adding the first type additive, is not lost by adding the second type additive. There is no change in the speed adjustment by the two kinds of additives, and when the concentration of the second kind additive is some, the plating speed is determined by the concentration of the second kind additive, but the concentration of the second kind is decreased. Even when the third type additive is present, the plating rate does not change and the same rate as when the second type additive is present to some extent is obtained, and further, the first type additive to the third type additive are obtained. Is that the plating rate does not change depending on the concentration of the third type additive. This is because the plating rate suppression effect of the third type additive is smaller than the plating rate suppression effect of the second type additive. That is, when the concentration of the second type additive is high, the plating rate is uniquely determined by the addition of the second type additive, but when the concentration of the second type additive is reduced and the suppression effect is reduced, the third type addition is performed. Even when the concentration of the second type additive is reduced due to the combined effect of the inhibitory effect of the additive, the plating rate equivalent to the case where the second type additive is present to some extent can be kept constant. it can. Furthermore, during plating, oxalate ions, sulfate ions, and glycolic acid accumulate due to the Kanitz arrow reaction, copper oxide formation-copper oxide disproportionation reaction, etc., but these substances are used as Type 3 additives as described later. It is possible to eliminate the change in the plating rate even if the plating reaction proceeds. Thereby, the plating rate can be kept constant. Furthermore, even when the copper concentration and pH change, the plating rate can be controlled between 0.5 and 2.0 μm / h by adding the first type additive, the second type additive and the third type additive. It becomes possible.
[0034]
First, the present invention provides an electroless copper plating solution comprising copper ions, a copper ion complexing agent, a reducing agent, and a pH adjusting agent. (1) As a first type additive, sulfur element or nitrogen is added to the annular portion. At least one selected from organic compounds or inorganic sulfur compounds having an element, (2) α-α ′ bipyridyl as a second type additive, IVB Group oxide or oxyacid salt, or at least one selected from group VA or VIA oxyacid salt or oxide, and (3) oxyalkylene glycol, sulfate, oxalate as the third type additive An electroless copper plating solution which is an aqueous solution containing at least one selected from carbonate, nitrate or glycolic acid.
[0035]
Here, as these first type additives, organic compounds having a sulfur element (S) or a nitrogen element (N) in a cyclic part represented by benzothiazole, thiazole, nicotinic acid, benzotriazole, mercaptosuccinic acid, or At least one or more inorganic sulfur compounds represented by potassium polysulfide, potassium sulfide, and sodium sulfide are added. As the second type additive, α-α′bipyridyl, sodium metasilicate, germanium are added. Represented by acid salts, germanium dioxide, sodium stannate IVB The addition of at least one or more of a group VA or VIA oxyacid salt or oxide represented by a group oxide or oxyacid salt, or sodium molybdate or sodium metavanadate. As the third type additive, polyalkylene glycol represented by polyethylene glycol, sulfate represented by nickel sulfate and potassium sulfate, oxalate represented by potassium oxalate, carbonate represented by sodium carbonate, Examples thereof include at least one of nitrates represented by potassium nitrate and glycolic acid.
[0036]
The concentration of the first and second type additives is preferably 0.01 to 100 mg / L, and the concentration of the third type additive is preferably 100 mg / L or more. When polyethylene glycol is used as the third type additive, the molecular weight is not particularly limited, but the concentration may be smaller as the molecular weight used is larger.
[0037]
Other components such as a copper salt, a cupric ion complexing agent, a reducing agent, and a pH adjusting agent are as follows. The copper salt used in the electroless copper plating solution is a soluble copper salt. Generally, copper sulfate, cupric chloride, copper pyrophosphate, etc. are used, and the concentration is about 0.01 to 0.08 mol / L. Is appropriate. The complexing agent for the cupric salt is EDTA, and its concentration is suitably about 0.02 to 0.16 mol / L. Glyoxylic acid is used as the reducing agent. The concentration is suitably 0.1 to 0.3 mol / L.
[0038]
As will be described later, when tartrate is used as a complexing agent, the ratio of glyoxylic acid / copper concentration and tartrate / copper concentration is important for plating. However, when EDTA is used as a complexing agent, the ratios of such complexing agent, reducing agent, and copper concentration are not so important. In order to increase the reaction rate, as described above, it is usually necessary to increase the copper concentration and the concentration of the reducing agent. When the anodic polarization curve of glyoxylic acid on copper was measured in a solution containing glyoxylic acid and EDTA at a predetermined concentration (after pH adjustment), the oxidation current of glyoxylic acid was proportional to the concentration even if the concentration of glyoxylic acid was increased. Does not increase and changes little. This shows that the reaction rate cannot be increased even if the concentration of glyoxylic acid is increased. Further, unlike the case where tartrate is used as the complexing agent, the potential of copper does not increase to the potential at which copper oxide is generated even when the copper concentration is increased. Therefore, the ratio of glyoxylic acid / copper concentration is not so important.
[0039]
As the pH adjuster, sodium hydroxide is generally used. However, in the present invention, KOH was used. The reason is as described above. The pH of the plating solution is preferably 10 or more, more preferably 11.5 to 13.5, since the uniformity of the plating in the through hole and the coverage are improved. It is desirable that the pH of the plating solution is 12.0 or higher as the pH is higher. However, considering that the self-decomposition reaction of glyoxylic acid by the Kanitz allo reaction proceeds as the pH is higher, the pH is more preferably in the range of 12-13.
[0040]
In the electroless plating method of the present invention, the temperature in plating is 50 ° C. or less, preferably 20 to 45 ° C., because of the problem relating to suppression of glyoxylic acid self-decomposition reaction at high temperatures. When the plating time is increased, it is natural that the plating in the through hole is improved, but the working efficiency is lowered. In the present invention, the plating time is optimally 15 to 25 minutes. Before performing electroless plating for forming a circuit of a printed circuit board, it is usually necessary to activate the substrate, and it is generally performed by adsorbing a noble metal catalyst typified by palladium. This process consists of the following four stages. (1) First, soft etching is performed using persulfate. (2) Then, after soaking in the preliminary solution, (3) the substrate is brought into contact with a solution of palladium colloid suspended in an acidic solution of tin chloride. (4) Finally, the tin is removed from the surface by dipping in an accelerator. The substrate is subjected to an electroless copper plating solution treatment using the electroless plating solution of the embodiment of the present invention. The method of creating a circuit for this printed circuit board is the same as that when tartrate is used as the complexing agent.
[0041]
Moreover, this invention immerses a to-be-plated material in the plating tank which accommodates the copper plating solution containing a copper ion, the complexing agent of a copper ion, a reducing agent, a pH adjuster, and 1st type-3rd type reducing agent. In the electroless copper plating apparatus for electroless copper plating, the reducing agent is glyoxylic acid and a salt thereof, the concentration is about 0.1 to 0.3M, and the complexing agent is EDTA and the concentration is 0.02 to 0.16M. Reducing agent replenishing means for replenishing the first reducing agent so that the pH is 12.0 to 13.0, the first and second reducing agent concentrations are 0.01 to 100 mg / L, and the third additive concentration is 100 mg / L or more. And a copper ion replenishing means for replenishing copper ions, a pH adjusting agent replenishing means for replenishing the pH adjusting agent, and an additive replenishing means for replenishing the first to third type additives. Features a temperature control device that controls the plating temperature to a predetermined temperature. That.
[0042]
Next, in the present invention, a case where glyoxylic acid is used as a reducing agent and tartrate is used as a complexing agent for copper ions will be described. As a result of plating by adjusting various reducing agent concentrations, copper ion concentrations, complexing agent concentrations, pH and temperature, a copper plating solution composition that can be used for a long time by setting a specific plating temperature. It is what I found. That is, the ratio of the reducing agent concentration and the copper ion concentration is not related to the absolute value of each concentration, but the concentration of the reducing agent is always 8.0 times or more, preferably 8.3 times or more, more desirably 8.5 to more than the copper ion concentration. 30 times, the concentration of the complexing agent is 6 times or less of the copper ion molar concentration, desirably 0.8 to 5 times, the ratio of both is important, and the plating temperature is 50 ° C. or less, more preferably 20 to 45 ° C. To do. The copper ion concentration is preferably 0.01 to 0.1 mol, more preferably 0.01 to 0.05 mol.
[0043]
In the case of continuous plating over a long period of time, stable plating can be performed by controlling the composition of the plating solution so that it always becomes such a condition from the initial stage of plating so as to satisfy this condition. Further, by controlling the composition of the plating solution within this concentration range, the time until plating is started is shortened to within 1 minute. The copper plating reaction formula is expressed by formula (2) when glyoxylic acid is used as a reducing agent. According to the reaction kinetics, it is usually necessary to increase the copper ion concentration and the glyoxylic acid concentration in order to increase the plating reaction rate.
[0044]
However, when the anodic polarization behavior of glyoxylic acid on copper was measured in a solution containing a predetermined concentration of glyoxylic acid and tartrate (after pH adjustment), the oxidation current density of glyoxylic acid was increased even if the concentration of glyoxylic acid was increased. Therefore, the plating reaction rate cannot be increased by increasing the concentration of glyoxylic acid. On the other hand, when the copper concentration is increased, the potential increases, the copper potential becomes a potential region where copper oxide is generated, and the plating reaction is stopped due to copper oxide generation.
[0045]
Copper is in the following equilibrium state in water, and the oxidation-reduction potential is given by the following equation.
[0046]
[Chemical 3]

[0047]
E in formulas (9) and (10) ₀ Is the standard redox potential of each reaction, and at 25 ° C., E in the formula (9) ₀ Is 0.471 (V), and E in equation (10) ₀ Is 0.609 (V). Accordingly, copper does not precipitate unless at least the potential of copper is equal to or less than E represented by the formula (9). Here, E is a potential expressed on the basis of SHE (standard hydrogen electrode potential at that temperature). It was found that the glyoxylic acid molar concentration must be at least 8 times the copper ion molar concentration in order to cause the reduction reaction of copper ions and the copper potential to enter such a potential region. That is, when glyoxylic acid is used as the reducing agent, there is no absolute value (threshold value) of glyoxylic acid and copper ion molar concentration necessary to continuously cause the copper plating reaction, but glyoxylic acid and copper ions. There is a threshold in the molar concentration ratio, and the molar concentration ratio is preferably 8.3 or more.
[0048]
In the present invention, the terms glyoxylic acid and glyoxylate, tartaric acid and tartrate are interchangeable unless otherwise specified. This is because their form changes with pH. The copper ion source is a soluble copper salt, and generally copper sulfate, copper chloride and the like are used. The appropriate copper ion concentration is determined by the ratio to the glyoxylic acid concentration as described above. For example, when the glyoxylic acid concentration is 0.24M, the copper ion concentration that can be plated is 0.029M or less, preferably 0.024M or less. It is desirable that
[0049]
The complexing agent contains tartrate represented by tartaric acid, rossell salt or potassium tartrate, and its proper concentration is 0.01 to 0.2 mol, preferably 0.02 to 0.1 mol, determined by the ratio to the copper ion concentration. The The complexing agent is necessary so that copper ions do not precipitate insoluble compounds such as oxides or hydroxides or copper oxalates in an aqueous solution, and the minimum concentration necessary for the stable presence of the copper ions is pH. The concentration of the complexing agent is required to be higher than that concentration. However, since tartaric acid itself has a reducing power, if it is added excessively, copper ions are reduced, so there is an upper limit concentration, and adding tartaric acid excessively to promote the plating reaction stably It is not preferable. When the tartaric acid concentration is excessive with respect to the copper ion concentration, it takes 5 minutes or more to start the plating reaction. An appropriate concentration is that the tartaric acid molar concentration is not more than 6 times the copper molar concentration, desirably not more than 5 times.
[0050]
The reducing agent contains glyoxylic acid or glyoxylate, and its concentration is preferably 0.05 to 1.0 mol, more preferably 0.1 to 0.5 mol, and is determined by the ratio to the copper ion concentration as described above. As the pH adjuster, sodium hydroxide is generally used. However, regarding the plating solution using glyoxylic acid as a reducing agent, by using KOH instead of NaOH as a pH adjuster, it is possible to suppress the Kanitz allo reaction compared to the case of using “surface technology, vol.42, No.9, 913-917 (1991) ”and“ 6th Academic Lecture Conference Proceedings 101-102 ”.
[0051]
In addition, oxalate ions are generated by the plating reaction and Kanitz allo reaction, but potassium oxalate has higher solubility than sodium oxalate and is less likely to precipitate, reducing problems due to formation of plating voids due to deposition on the substrate, etc. . Therefore, it is desirable to use KOH as the pH adjuster used in the plating solution. The pH of the plating solution is preferably 10 or more using KOH, desirably 11.5 to 13.5, more desirably 12.0 to 13.0. In addition, although not essential, when performing plating over a long period of time, add a stabilizer and a speed regulator to prevent precipitation of copper particles in the liquid due to copper oxide formation-copper oxide self-decomposition reaction. Is preferred. The stabilizer and speed regulator added here are the same as in the case of a plating solution using formaldehyde as a reducing agent. The types and characteristics of stabilizers and reducing agents are described in, for example, “Surface Technology Handbook (Summary), Surface Technology Association, P.336”. Representative examples include cyanide, 2,2′-bipyridyl, There are organic sulfur-containing aircraft in which sulfur is divalent and polyethylene glycol.
[0052]
In the electroless plating method of the present invention, the temperature in plating is 50 ° C. or less, preferably 20 to 45 ° C., because of problems relating to the stability of tartaric acid at high temperatures and the suppression of glyoxylic acid self-decomposition reaction. In order to increase the stability of copper ions, as a method other than the addition of a stabilizer, it is desirable that the plating solution is stirred. Examples of the stirring method include air stirring and stirring with a stirrer, and the effect can be further improved by adding a stabilizer. Before performing electroless plating for producing a circuit of a printed circuit board, it is usually necessary to activate the substrate, and it is generally performed by adsorbing a noble metal catalyst typified by palladium. This process consists of the following four stages. (1) First, soft etching is performed using persulfate. (2) Then, after dipping in the preliminary solution, (3) the substrate is brought into contact with a solution of palladium colloid suspended in an acidic solution of tin chloride. (4) Finally, the tin is removed from the surface by dipping in an alkali promoter. The substrate is subjected to an electroless copper plating solution treatment using the electroless plating solution of the embodiment of the present invention.
[0053]
In the present invention, the plating solution replenishment method is used when plating is carried out stably and continuously. In addition to the plating reaction, the Kanitz allo reaction, copper oxide formation-self-decomposition reaction of copper oxide, and take-out from the substrate (the substrate enters the plating tank when wet and leaves the plating tank with plating solution) ) Reduces copper ion concentration, reducing agent concentration, alkali concentration, and the like. Therefore, in order to continue the plating, it is necessary to appropriately replenish the plating solution. Since the decreasing rates of the copper concentration, the alkali concentration, and the reducing agent concentration due to the plating reaction and the side reaction are different, the amount to be replenished is different. Therefore, when replenishing the plating solution, it is necessary to individually replenish the copper ion source, the alkali, and the reducing agent so that the plating solution in the plating tank can be plated. In that case, when the composition of the plating solution is less than 7 times the glyoxylic acid molar concentration relative to the copper ion molar concentration, it is 8 times or more (preferably 10 times or more), and the tartaric acid molar concentration relative to the copper ion molar concentration is 6 times or less (desirably 5 times). It is necessary to replenish each so that
[0054]
The present invention relates to an electroless copper plating apparatus for immersing a material to be plated in a plating tank containing a copper plating solution containing copper ions, a copper ion complexing agent, a reducing agent and a pH adjusting agent, and performing electroless copper plating. The reducing agent is glyoxylic acid and a salt thereof, the concentration is 8 times or more of the copper ion concentration, and the complexing agent is tartaric acid or a salt thereof, and the reduction is performed so that the concentration is 6 times or less of the copper ion concentration. A reducing agent replenishing means for replenishing the agent, a copper ion replenishing means for replenishing the copper ions, and a pH replenishing means for replenishing the pH adjusting agent, and controlling the plating bath temperature in the plating tank to a predetermined temperature. Features a temperature control device.
[0055]
The present invention provides a printed circuit board to which copper plating is applied by a plating solution and a plating solution replenishment method (management method). Glass epoxy is generally used as a substrate material for printed circuit boards, but this plating solution can be used for glass, ceramics, etc. in addition to organic substances such as polyimide and polytetrafluoroethylene, in addition to this glass epoxy. Can be applied.
[0056]
DETAILED DESCRIPTION OF THE INVENTION
Regarding the embodiment of the present invention, since the behavior differs when EDTA is used as the complexing agent and when tartrate is used, the complexing agent will be described separately. Examples 1 to 22 and Comparative Examples 1 to 11 are cases where EDTA is used as a complexing agent, and Examples 23 to 43 and Comparative Examples 12 to 20 are cases where tartrate is used as a complexing agent.
[0057]
Hereinafter, examples and comparative examples when EDTA is used as the complexing agent will be described. In the comparative example, an experiment was conducted to examine the present invention, and the results are shown with respect to conditions where the inside of the through hole could not be uniformly plated or conditions where the stability of the plating solution was not obtained.
[0058]
FIG. 1 is a cross-sectional view of an electroless copper plating apparatus used in this example and a comparative example. As shown in FIG. 1, the plating solution 2 is supplied to the plating tank 1 from the copper sulfate supply line 3, the EDTA supply line 4, the glyoxylic acid supply line 5, and the first to third type additive supply lines 6 to 8 as the plating progresses. The material to be plated 12 is plated while being replenished. During plating, the temperature is adjusted to a predetermined temperature by the temperature controller, and air is supplied into the plating solution by the air pump 10. The plating solution 2 that has been erected is stored in the tank unit 11.
[0059]
Example 1
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Potassium sulfide 1.0 ppm as the first type additive, α, α′-bipyridyl 10 ppm as the second type additive, PEG1000 as the third type additive 1.0 g / L pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0060]
A double-sided copper-clad laminate with through-holes was immersed in a cleaner conditioner (trade name: CLC-601, manufactured by Hitachi Chemical Co., Ltd.). Next, after performing soft etching using ammonium persulfate and sulfuric acid, pre-dip (same product name: PD-301), sensitizer (same product name: HS-202B), adhesion treatment accelerator (same product name) : ADP-601) was used for catalyst treatment (hereinafter, the above steps were abbreviated as catalyst treatment).
[0061]
After the above catalyst treatment and washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes.
[0062]
After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate on the resin was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.21 μm / h.
[0063]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0064]
(Example 2)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Potassium sulfide 1.0 ppm as the first type additive, α, α′-bipyridyl 1.0 ppm as the second type additive, as the third type additive PEG1000 1.0 g / L pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0065]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.25 μm / h.
[0066]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0067]
(Example 3)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Potassium sulfide 0.5.0ppm as the first type additive, α, α'-bipyridyl 1.0ppm, the third type additive as the second type additive As PEG1000 1.0g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0068]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.32 μm / h.
[0069]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0070]
Example 4
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Potassium sulfide 1.0ppm as the first type additive, Sodium metavanadate 1.0ppm as the second type additive, Potassium sulfate 5.0 as the third type additive g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0071]
The operation shown in Example 1 below was performed as the catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.24 μm / h.
[0072]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0073]
(Example 5)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Thiazole 5.0 ppm as the first type additive, Sodium metavanadate 1.0 ppm as the second type additive, Potassium oxalate 5.0 as the third type additive g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0074]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.18 μm / h.
[0075]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0076]
(Example 6)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.04M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Thiazole 5.0 ppm as the first type additive, sodium metavanadate 0.1.0 ppm as the second type additive, glycolic acid 5.0 as the third type additive g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0077]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.06 μm / h.
[0078]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0079]
(Example 7)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Benzimidazole 5.0ppm as the first type additive, Sodium metasilicate 0.5.0g / L as the second type additive, As the third type additive PEG1000 1.0 g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0080]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.20 μm / h.
[0081]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0082]
(Example 8)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Benzimidazole 5.0ppm as the first type additive, Sodium metasilicate 0.5.0g / L as the second type additive, As the third type additive PEG1000 1.0 g / L, pH (adjusted with KOH): 12.4
The temperature of the plating solution was adjusted to 30 ° C.
[0083]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating rate in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin in this plating solution was 0.88 μm / h.
[0084]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0085]
Example 9
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.1M Benzimidazole 5.0ppm as the first type additive, Sodium metasilicate 0.5.0g / L as the second type additive, As the third type additive PEG1000 1.0 g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0086]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating rate in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.05 μm / h.
[0087]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0088]
(Example 10)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M benzothiazole 5.0ppm as the first kind additive, germanium dioxide 50ppm as the second kind additive, potassium sulfate 5.0g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0089]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating rate in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.62 μm / h.
[0090]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0091]
(Example 11)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M benzothiazole 5.0ppm as the first type additive, α, α'-bipyridyl 1.0ppm as the second type additive, as the third type additive Potassium sulfate 5.0 g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0092]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.64 μm / h.
[0093]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0094]
(Example 12)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M benzothiazole 5.0ppm as the first type additive, α, α'-bipyridyl 1.0ppm as the second type additive, as the third type additive Potassium sulfate 1.0g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0095]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.82 μm / h.
[0096]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0097]
(Example 13)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M benzothiazole 5.0ppm as the first type additive, α, α'-bipyridyl 10ppm as the second type additive, sulfuric acid as the third type additive Potassium 1.0g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0098]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.37 μm / h.
[0099]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0100]
(Example 14)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.04M, EDTA-4H: 0.12M, glyoxylic acid: 0.1M Potassium sulfide 0.1 ppm as the first type additive, Sodium metavanadate 1.0 ppm as the second type additive, Potassium sulfate 1.0 as the third type additive g / L, pH (adjusted with KOH): 12.4
The temperature of the plating solution was adjusted to 30 ° C.
[0101]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 0.52 μm / h.
[0102]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0103]
(Example 15)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Benzotriazole 0.1ppm as the first type additive, Sodium stannate as the second type additive
10ppm, PEG600 10g / L as third type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0104]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 0.84 μm / h.
[0105]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0106]
(Example 16)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Mercaptosuccinic acid 1.0ppm as the first type additive, sodium metavanadate 0.1ppm as the second type additive, PEG600 10g as the third type additive / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0107]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.82 μm / h.
[0108]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0109]
(Example 17)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Potassium sulfide 0.05ppm as the first kind additive, 0.01ppm sodium metavanadate as the second kind additive, Potassium sulfate 10g as the third kind additive / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0110]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.82 μm / h.
[0111]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0112]
(Example 18)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Potassium sulfide 0.5ppm and mercaptosuccinic acid 0.5ppm as the first type additive, α, α'-bipyridyl 1.0ppm as the second type additive Sodium metavanadate 0.1ppm, Potassium sulfate 1.0g / L and PEG600 1.0g / L as third type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0113]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 0.99 μm / h.
[0114]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0115]
Example 19
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Thiazole 5.0 ppm as the first type additive, Sodium metavanadate 1.0 ppm as the second type additive, Potassium oxalate 5.0 as the third type additive g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 45 ° C.
[0116]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.68 μm / h.
[0117]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0118]
(Example 20)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, Glyoxylic acid: 0.3M Thiazole 5.0 ppm as the first type additive, Sodium metavanadate 1.0 ppm as the second type additive, Potassium oxalate 5.0 as the third type additive g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 25 ° C.
[0119]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.12 μm / h.
[0120]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0121]
(Example 21)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Mercaptosuccinic acid 1.0ppm as the first type additive, sodium metavanadate 0.1ppm as the second type additive, PEG600 0.1 as the third type additive g / L, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0122]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.89 μm / h.
[0123]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0124]
(Example 22)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M Mercaptosuccinic acid 1.0ppm as the first type additive, sodium metavanadate 0.1ppm as the second type additive, PEG600 10g as the third type additive / L, pH (adjusted with KOH): 12.0
The temperature of the plating solution was adjusted to 30 ° C.
[0125]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.63 μm / h.
[0126]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0127]
(Comparative Example 1)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, no additives, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0128]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin was dark brown and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 6.50 μm / h.
[0129]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, especially in the glass cloth part. When this liquid was allowed to stand, a decomposition reaction occurred in about 30 minutes, and the copper particles floated in the liquid.
[0130]
(Comparative Example 2)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, α, α'-bipyridyl: 10ppm as the second type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0131]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate was pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.45 μm / h.
[0132]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. However, when this liquid was allowed to stand, a decomposition reaction occurred after 12 hours, and the copper particles were floating in the liquid.
[0133]
(Comparative Example 3)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, sodium metasilicate as the second type additive: 0.5.0 g / L, PEG1000 as the third type additive: 1.0 g / L, pH (in KOH Adjustment): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0134]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate was dark brown and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.62 μm / h.
[0135]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. However, when this liquid was allowed to stand, a decomposition reaction occurred after 12 hours, and the copper particles were floating in the liquid.
[0136]
(Comparative Example 4)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, α, α'-bipyridyl: 10ppm as the second type additive, PEG1000: 1.0g / L, pH (adjusted with KOH as the third type additive) : 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0137]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate was pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.59 μm / h.
[0138]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. However, when this liquid was allowed to stand, a decomposition reaction occurred after 12 hours, and the copper particles were floating in the liquid.
[0139]
(Comparative Example 5)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, potassium sulfide: 1.0ppm as the first type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0140]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate was dark brown and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 5.8 μm / h.
[0141]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, especially in the glass cloth part. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0142]
(Comparative Example 6)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, Glyoxylic acid: 0.3M, Benzimidazole: 50ppm as the first type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0143]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate was dark brown and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 4.21 μm / h.
[0144]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, especially in the glass cloth part. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0145]
(Comparative Example 7)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, Glyoxylic acid: 0.3M, Benzimidazole: 1.0 g / L as the first type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0146]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. The copper deposited on the resin plate was dark brown and had adhesiveness, but there were a plated part and a non-plated part, and it was not uniformly plated. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating, assuming that the plating was uniformly performed. The plating rate on the resin plate in this plating solution was 0.5 μm / h or less.
[0147]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, especially in the glass cloth part. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0148]
(Comparative Example 8)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, benzothiazole: 5.0ppm as the first type additive, α, α'-bipyridyl: 1.0ppm as the second type additive, pH (adjusted with KOH : 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0149]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 2.52 μm / h.
[0150]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, especially in the glass cloth part. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0151]
(Comparative Example 9)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA-4H: 0.12M, glyoxylic acid: 0.3M benzothiazole 5.0ppm as the first type additive, α, α'-bipyridyl 10ppm as the second type additive, no third type additive, pH (adjusted with KOH): 12.4
The temperature of the plating solution was adjusted to 30 ° C.
[0152]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 1.43 μm / h.
[0153]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that a uniform plating film having no dark field and having no defects was obtained. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0154]
(Comparative Example 10)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, potassium sulfide: 1.0ppm as the first type additive, sodium metavanadate: 0.05ppm as the second type additive, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0155]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark brown and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 3.42 μm / h.
[0156]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, especially in the glass cloth part. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
[0157]
(Comparative Example 11)
4.5 L of a plating solution having the following composition was adjusted.
Copper sulfate: 0.06M, EDTA: 0.12M, glyoxylic acid: 0.3M, potassium sulfide: 0.05ppm as the first type additive, sodium metavanadate as the second type additive: 0.01ppm, pH (adjusted with KOH): 12.8
The temperature of the plating solution was adjusted to 30 ° C.
[0158]
The operation shown in Example 1 was performed as a catalyst treatment. After washing with water, it was immersed in a plating solution adjusted to the above conditions for 20 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes. After immersion in the plating solution, the plating reaction started immediately with the outgassing. Copper deposited on the resin plate was dark brown and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate was determined using the weight difference and specific gravity of the resin plate before and after plating. The plating rate on the resin plate in this plating solution was 4.22 μm / h.
[0159]
The state of plating in the through hole was evaluated by a backlight test. It was confirmed that the light transmission part was a non-uniform plating film having defects, particularly in the glass cloth part. Even if this solution was allowed to stand, no precipitation of copper could be confirmed.
The results of Examples 1 to 22 and Comparative Examples 1 to 11 are summarized in Tables 1 and 2.
[0160]
[Table 1]

[0161]
[Table 2]

[0162]
As shown in Examples 1 to 22 and Comparative Examples 1 to 11, when the plating rate on the resin plate is between 0.5 and 2.0 μm / h, the inside of the through hole is independent of the type and concentration of the additive. It turns out that it has plated uniformly.
[0163]
However, as described above, since the concentrations of the additives are reduced by continuously plating, as shown in Comparative Example 9, for example, even when there is no third type additive, on the resin plate. If the plating speed is within 0.05 to 2.0 μm / h, the inside of the through hole is uniformly plated, but the second type additive used as a speed adjustment as shown in Comparative Example 8 by continuous plating. When a certain bipyridyl concentration decreases, the plating speed exceeds the appropriate range, so that the inside of the through hole cannot be uniformly plated. However, even under this condition, when the third type additive is added as shown in Examples 11 and 12, the plating rate is within the appropriate range, and the through hole is uniformly plated.
[0164]
Also, for example, as shown in Examples 1 and 2, and Examples 12 and 13, even when the concentration of the second type additive is changed, the plating rate is hardly increased due to the addition of the third type additive. There is no change and the inside of the through hole can be uniformly plated. Further, for example, as shown in Examples 11 and 12, when the types and concentrations of the first-type additive and the second-type additive are the same, the plating rate changes almost even if the concentration of the third-type additive changes. Without plating, the inside of the through hole can be uniformly plated.
[0165]
As shown in Example 14, even when the copper sulfate concentration, the glyoxylic acid concentration, and the pH are lowered, the plating rate is appropriate when there is the first type additive, the second type additive, and the third type additive. Within range. As shown in Comparative Example 11, when the concentration of the first type additive and the second type additive is extremely reduced, the plating speed exceeds the appropriate range, and it becomes impossible to uniformly plate the through hole. As shown in Example 17, the presence of the third type additive allows the plating rate to fall within an appropriate range, and the through hole can be uniformly plated.
[0166]
As shown in Example 18, in the first type additive, the second type additive, and the third type additive, even if a plurality of types of additives are used in each case, the same effect as in the case of using one type each is seen. It is done.
[0167]
As shown in Examples 19 and 20, even when the temperature is relatively high, such as 25 or 45 ° C, and when the temperature is relatively low, the same effect as in the case of 30 ° C is observed. However, when the temperature was 50 ° C. or higher, the amount of decrease due to the decomposition reaction of glyoxylic acid was large, which was not practical.
[0168]
As seen in Example 21, when 0.1 g / L of PEG600 was added as the third type additive, the same effect as when 10 g / L of PEG600 was added as shown in Example 16 was observed. . However, when the amount of the third type additive is extremely small, the effect is reduced when the concentration is extremely lowered due to the consumption due to the loading and unloading of the substrate as described above. Therefore, the amount is preferably 1.0 g / L or more.
As shown in Example 22, the same effect as in the case of 12.8 can be seen at pH 12.0.
[0169]
As long as the above-described examples of the first-type additive, the second-type additive, and the third-type additive are used, any combination of the compounds can achieve the same effects as those shown in the above examples.
[0170]
Next, Examples 23 to 43 and Comparative Examples 12 to 20 when tartrate is used as the complexing agent will be described.
[0171]
In Comparative Examples 12 to 20, experiments were conducted to examine the present invention, but the results under conditions where plating could not be performed and conditions shown in the prior art are shown. In Examples 23-43 and Comparative Examples 12-20, the electroless copper plating solution composition shown in Table 3 was used.
[0172]
[Table 3]

[0173]
Table 3 shows copper sulfate, sodium potassium tartrate, glyoxylic acid, pH, PEG1000, 2, 2'-bipyridyl, molar ratio of tartrate and copper sulfate, molar ratio of glyoxylic acid and copper sulfate, and plating solution temperature. It is shown. KOH was used for pH adjustment. All plating solutions were adjusted to 4.5L.
[0174]
In addition, Table 3 shows the potential of the catalyst-treated copper. In this example, it was about -100 mV immediately after immersion, but the value decreased within 1 minute was also shown. In this example, the plating solution temperature was 25 ° C., and all satisfied the condition of E = 0.471-0.0001984 × T × pH. In Comparative Examples 12, 14, and 18, values immediately after the immersion were shown, and in Comparative Examples 15, 17, and 20, values after 10 minutes were shown, and none of the conditions was satisfied.
[0175]
The apparatuses used in Examples 23 to 43 and Comparative Examples 12 to 20 are the same as those shown in FIG. However, the tartaric acid supply line is used instead of the EDTA supply line 4.
[0176]
(Example 23)
A double-sided copper-clad laminate with through-holes was immersed in a cleaner conditioner (trade name: CLC-601, manufactured by Hitachi Chemical Co., Ltd.). Next, after performing soft etching using ammonium persulfate and sulfuric acid, pre-dip (same product name: PD-301), sensitizer (same product name: HS-202B), adhesion treatment accelerator (same product name) : ADP-601) was used for catalyst treatment (hereinafter, the above steps were abbreviated as catalyst treatment). After washing with water, it was immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution). The plating speed in the plating solution was determined by converting the thickness per hour (μm / h) using the density from the weight difference before and after plating of the double-sided copper-clad laminate having through holes.
[0177]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 1.2 μm / h. Very little copper deposition was seen at the bottom of the container.
[0178]
(Example 24)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0179]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 4.0 μm / h. No copper deposition was observed at the bottom of the container.
[0180]
(Example 25)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0181]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 2.2 μm / h. No copper deposition was observed at the bottom of the container.
[0182]
(Example 26)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0183]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 2.0 μm / h. No copper deposition was observed at the bottom of the container.
[0184]
(Example 27)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.3 L / min / L (plating solution).
[0185]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 5.0 μm / h. Some copper deposition was seen at the bottom of the container.
[0186]
(Example 28)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.3 L / min / L (plating solution).
[0187]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 5.4 μm / h. Considerable copper deposition was seen at the bottom of the container.
[0188]
(Example 29)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0189]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 3.5 μm / h. No copper deposition was observed at the bottom of the container.
[0190]
(Example 30)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0191]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 2.1 μm / h. No copper deposition was observed at the bottom of the container.
[0192]
(Example 31)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0193]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 1.2 μm / h. No copper deposition was observed at the bottom of the container.
[0194]
(Example 32)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0195]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 3.6 μm / h. No copper deposition was observed at the bottom of the container.
[0196]
(Example 33)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0197]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 3.2 μm / h. No copper deposition was observed at the bottom of the container.
[0198]
(Example 34)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0199]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 1.4 μm / h. No copper deposition was observed at the bottom of the container.
[0200]
(Example 35)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0201]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 3.6 μm / h. No copper deposition was observed at the bottom of the container.
[0202]
(Example 36)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0203]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper had a dark brick color and adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 2.8 μm / h. No copper deposition was observed at the bottom of the container.
[0204]
(Example 37)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0205]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 3.6 μm / h. No copper deposition was observed at the bottom of the container.
[0206]
(Example 38)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0207]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 4.3 μm / h. No copper deposition was observed at the bottom of the container.
[0208]
(Example 39)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0209]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 3.8 μm / h. No copper deposition was observed at the bottom of the container.
[0210]
(Example 40)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0211]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 0.95 μm / h. No copper deposition was observed at the bottom of the container.
[0212]
(Example 41)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0213]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 1.2 μm / h. No copper deposition was observed at the bottom of the container.
[0214]
(Example 42)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0215]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 2.8 μm / h. No copper deposition was observed at the bottom of the container.
[0216]
(Example 43)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0217]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink and had adhesiveness, and was uniformly deposited on one surface including the edge portion. The plating rate in this plating solution was 2.6 μm / h. No copper deposition was observed at the bottom of the container.
[0218]
(Comparative Example 12)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
[0219]
Even when the catalyst-treated laminate was immersed in the plating solution, no plating reaction occurred, and no copper deposition could be confirmed on the substrate. Copper deposition was observed at the bottom of the container.
The potential of the copper treated with the catalyst was −120 mV or more immediately after immersion, and did not satisfy the condition of E = 0.471-0.0001984 × T × pH.
[0220]
(Comparative Example 13)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.4 L / min / L (plating solution).
[0221]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink, but the adhesion was poor. The plating was uneven, and there were portions that could be plated and portions that were not. Since plating was not performed uniformly, the plating rate could not be determined. Several minutes after the start of plating, copper particles floated in the plating tank, and a large amount of copper was deposited on the bottom of the container.
[0222]
(Comparative Example 14)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
Even when the catalyst-treated laminate was immersed in the plating solution, no plating reaction occurred, and no copper deposition could be confirmed on the substrate. Copper deposition was observed at the bottom of the container.
[0223]
(Comparative Example 15)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.4 L / min / L (plating solution).
[0224]
After 5 minutes of immersion in the plating solution, the plating reaction started as the gas was released. The deposited copper was dark pink, but the adhesion was poor. The plating was uneven, and there were portions that could be plated and portions that were not. Although it was not uniformly plated, the plating rate in this plating solution was 0.5 μm / h when it was assumed that plating was performed on average.
The potential of the copper treated with the catalyst was about -100 mV immediately after immersion, but after that, the potential decreased to -280 mV or less, satisfying the condition of E = 0.471-0.0001984 × T × pH, but reached it. It took more than 10 minutes to complete.
[0225]
(Comparative Example 16)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.4 L / min / L (plating solution).
Even when the catalyst-treated laminate was immersed in the plating solution, no plating reaction occurred, and no copper deposition could be confirmed on the substrate. Copper deposition was observed at the bottom of the container.
[0226]
(Comparative Example 17)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
Even when the catalyst-treated laminate was immersed in the plating solution, no plating reaction occurred, and no copper deposition could be confirmed on the substrate. Copper deposition was observed at the bottom of the container.
[0227]
(Comparative Example 18)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.2 L / min / L (plating solution).
Even when the catalyst-treated laminate was immersed in the plating solution, no plating reaction occurred, and no copper deposition could be confirmed on the substrate. Copper deposition was observed at the bottom of the container.
[0228]
(Comparative Example 19)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.4 L / min / L (plating solution).
[0229]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink, but the adhesion was poor. The plating was uneven, and there were portions that could be plated and portions that were not. Although it was not uniformly plated, the plating rate in this plating solution was 0.34 μm / h when it was assumed that plating was performed on average.
[0230]
(Comparative Example 20)
The double-sided copper-clad laminate with through-holes was treated with a catalyst and then immersed in a plating solution adjusted to the above conditions for 15 minutes. The plating bath load is 1 dm ² The area of the substrate was adjusted to be / L. During plating, the plating solution was always stirred with air under the condition of 0.4 L / min / L (plating solution).
[0231]
After being immersed in the plating solution, the plating reaction was started as the gas was released. The deposited copper was dark pink, but the adhesion was poor. The plating was uneven, and there were portions that could be plated and portions that were not. Although not uniformly plated, the plating rate in this plating solution when assuming that plating was performed on average was 0.42 μm / h.
The potential of the copper treated with the catalyst was about -100 mV immediately after immersion, but after that, the potential decreased to -280 mV or less, satisfying the condition of E = 0.471-0.0001984 × T × pH, but reached it. It took more than 10 minutes to complete.
[0232]
FIG. 2 shows a case where, in Examples 23 to 43 and Comparative Examples 12 to 20, the tartrate molar concentration / copper sulfate molar concentration and glyoxylic acid molar concentration / copper sulfate molar concentration at the plating solution temperature of 25 ° C. were used as parameters. This indicates whether or not plating is possible. From this, it can be seen that the conditions for uniform plating are tartrate molar concentration / copper molar concentration of 6 or less and glyoxylic acid molar concentration / copper molar concentration of 8.0 or more, preferably 8.3 or more. Under conditions where uniform plating is possible, even if the copper potential after the catalyst treatment is about -100 mV immediately after dipping, it drops within 1 minute to -280 mV or less, and E = 0.471-0.0001984 × The condition of T × pH was satisfied.
[0233]
(Example 44)
FIG. 3 shows the plating rate on the resin when the tartrate (Rossel salt) concentration is fixed at O.089M, the glyoxylic acid concentration is fixed at 0.26M, and the copper concentration is changed. When the copper sulfate concentration is O.06M, the plating rate is slow and uniform plating is not possible. When the copper concentration is 0.06M, the tartrate / copper sulfate concentration ratio is 1.48, and the glyoxylic acid concentration / copper sulfate concentration ratio is 4.3. When the copper sulfate concentration is 0.03M or less, the plating rate increases and the plating can be made uniform. When the copper concentration is 0.03M, the tartaric acid / copper sulfate concentration ratio is 2.96, and the glyoxylic acid concentration / copper sulfate concentration ratio is 8.7. When the copper sulfate concentration is polished, the plating rate decreases after showing the maximum rate at 0.018M. When the copper sulfate concentration is 0.006M, the plating completely lacks uniformity. When the copper concentration is 0.006M, the tartrate / copper sulfate concentration ratio is 14.83, and the glyoxylic acid concentration / copper sulfate concentration ratio is 43.3.
[0234]
FIG. 4 shows the copper polarization curves for various concentrations of copper sulfate and glyoxylic acid when the tartaric acid concentration is 0.089M. The potential across current 0 is the plating potential. In copper sulfate O.06M and glyoxylic acid 0.26M with non-uniform plating, the potential is -480mV (vs. Ag / AgC1), (-280 mV vs. SHE), a region where copper oxide is generated. . In other cases, the potential is .480 mV (vs. Ag / AgCl) or less, which is an area where copper is generated and can be plated.
[0235]
(Example 45)
In this embodiment, a case where the substrate is continuously plated will be described. Since the substrate enters the plating bath after passing through the catalyst treatment and the water washing step, the substrate enters the plating tank in a wet state. Since the substrate enters the washing tank after plating, it leaves the plating tank with the plating solution attached. Therefore, as described above, in addition to the plating reaction and side reaction, the copper ion concentration and the glyoxylic acid concentration are decreased with time by this operation when continuously plating. The concentration of tartrate is not reduced by side reactions, but the concentration is reduced by this operation.
[0236]
[Table 4]

[0237]
Table 4 shows the time change of the copper ion molar concentration, glyoxylic acid molar concentration, tartrate molar concentration, pH and tartrate molar concentration / copper ion molar concentration, glyoxylic acid molar concentration / copper ion molar concentration measured at each time. With time, the copper ion molar concentration, glyoxylic acid molar concentration, tartrate molar concentration, pH, tartrate molar concentration / copper ion molar concentration, glyoxylic acid molar concentration / copper ion molar concentration are decreasing. After 3 hours, the glyoxylic acid molar concentration / copper ion molar concentration ratio reached 8.1, and the copper ion concentration, glyoxylic acid concentration, tartaric acid concentration, and pH decreased, so the ratio of glyoxylic acid molar concentration / copper ion molar concentration was 10 or more. Then, copper sulfate, glyoxylic acid, tartrate and alkali were added to continue plating.
[0238]
After 5 hours, the ratio of the glyoxylic acid molar concentration / copper ion molar concentration was 8.3 or less, resulting in uneven plating. Furthermore, since copper ion concentration, glyoxylic acid concentration, tartaric acid concentration, and pH decreased, copper sulfate, glyoxylic acid, tartrate, and alkali were added so that the ratio of glyoxylic acid molar concentration / copper ion molar concentration would be 10 or more, and plating Continued.
[0239]
The same treatment was performed after 7 hours. After plating for 8 hours, the plating solution was held in the air bubbled state until the next day. No precipitation of copper particles was observed in the plating bath.
[0240]
After 24 hours, when the plating solution was analyzed, the glyoxylic acid molar concentration / copper ion molar concentration ratio became 5.3, and the copper ion concentration, glyoxylic acid concentration, and pH decreased. Copper sulfate, glyoxylic acid, tartrate, and alkali were added and plated so that the ionic molar concentration ratio was 10 or more. The potential of copper during plating is always -250 mV or less, E ₀ = 0.471-0.0001984 × T × pH potential range.
[0241]
As shown in Table 4, the glyoxylic acid molar concentration / glyoxylic acid molar concentration / copper ion molar concentration ratio decreased to 6 times, so that the glyoxylic acid molar concentration (glyoxylic acid molar concentration / copper ion) molar concentration ratio was about 15 times or more. It became clear that by adding every 2 hours, a stable and uniform copper plating can be obtained for a long time thereafter.
[0242]
【The invention's effect】
By using a plating solution containing glyoxylic acid as a reducing agent, the burden on the human body and the environment can be reduced. In addition, when EDTA is used as the complexing agent, the concentration of the first type additive for liquid stability, the second type additive for speed adjustment, and the second type additive changes when the plating solution is used. Even when a third type additive having a speed buffering action that does not change the speed is added, a stable plating can be performed regardless of a change in the concentration of the additive by continuous plating. Furthermore, when tartrate is used as the complexing agent, electroless copper that can stably and uniformly obtain copper plating over a long period of time by controlling the composition ratio of the plating solution when using the plating solution. It is possible to provide a plating solution and its method and apparatus.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an electroless copper plating apparatus used in an embodiment of the present invention.
FIG. 2 is a graph showing whether or not plating can be performed using tartrate molar concentration / copper sulfate molar concentration and glyoxylic acid molar concentration / copper sulfate molar concentration as parameters.
FIG. 3 is a diagram showing a relationship between a copper plating rate on a resin plate and a copper concentration.
FIG. 4 is a diagram showing a current density and a potential showing a polarization of copper in an aqueous Roselle salt solution containing copper and glyoxylic acid (GOA).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Plating tank, 2 ... Plating solution, 3 ... Copper sulfate supply line, 4 ... EDTA supply line, 5 ... Glyoxylic acid supply line, 6-8 ... 1st-3rd type additive supply line, 9 ... Temperature controller, DESCRIPTION OF SYMBOLS 10 ... Air pump, 11 ... Dividing tank unit, 12 ... To-be-plated material.

Claims (23)

Electroless copper plating solution consisting of copper ion, copper ion complexing agent, reducing agent glyoxylic acid and pH adjuster, (1) Organic having sulfur element or nitrogen element in the cyclic part as first type additive At least one selected from a compound , mercaptosuccinic acid and an inorganic sulfur compound, (2) as a second type additive, α-α ′ bipyridyl, group IVB oxide or oxyacid salt, or group VA or VIA oxygen At least one or more selected from acid salts or oxides, and (3) at least one or more selected from oxyalkylene glycol, sulfate, oxalate, carbonate, nitrate or glycolic acid as the third type additive An electroless copper plating solution which is an aqueous solution containing the electroless copper plating solution. Wherein (1) an organic compound benzothiazole having a sulfur element or a nitrogen element in an annular portion of the first type additive, thiazole, nicotinic acid, selected benzotriazole or al, inorganic sulfur compounds, potassium polysulfide, potassium sulfide (2) Group IVB oxide or oxyacid salt of the second type additive is selected from sodium metasilicate, germanate, germanium dioxide, sodium stannate, and is selected from VA or VIA group. The oxyacid salt or oxide is selected from sodium molybdate or sodium metavanadate. (3) The third type additive, oxyalkylene glycol, is selected from polyethylene glycol or polypropylene glycol, and the sulfate is potassium sulfate or sulfuric acid. Selected from nickel, oxalate is potassium oxalate, charcoal Salt is a sodium carbonate, an electroless copper plating solution according to claim 1, wherein the nitrate is potassium nitrate.   The said 1st type, 2nd type, and 3rd type additive were added so that the electroless copper plating speed | rate on the resin board which performed the catalyst process might be 0.5-2.0 micrometers / h. The electroless copper plating solution according to 1 or 2. Copper ions, amino compounds typified by triethanolamine and diethylenetriaminepentaacetic acid as complexing agents for copper ions, oxycarboxylates typified by gluconate and citrate, polyhydric alcohols typified by glycerol and glycol Electroless copper plating solution comprising at least one selected from the group consisting of ethylenediaminetetraacetic acid, tartrate, ethylenediaminetetra-2-propanol, iminodiacetic acid and nitrilotriacetic acid, and glyoxylic acid and a pH adjuster as a reducing agent (1 ) As the first type additive, at least one or more selected from organic compounds or inorganic sulfur compounds having sulfur element or nitrogen element in the cyclic part, (2) As the second type additive, α-α ′ bipyridyl, group IVB Oxides or oxyacid salts of VA or VIA or VIA oxyacid salts or acids And (3) an aqueous solution containing at least one selected from oxyalkylene glycol, sulfate, oxalate, carbonate, potassium nitrate or glycolic acid as the third type additive. An electroless copper plating solution.   At the stage of bathing the plating solution, the additive amount of the first type additive is 0.01 to 100 mg / L, the additive amount of the second type additive is 0.01 to 100 mg / L, and the third type additive is added in the previous period. The electroless copper plating solution according to any one of claims 1 to 4, wherein an additive amount of the agent is 100 mg / L or more.   The electroless copper plating solution according to any one of claims 1 to 5, wherein the temperature is 50 ° C or lower.   The electroless copper plating solution according to any one of claims 1 to 6, wherein the pH is in the range of 12 to 13. It is a management method of the electroless copper plating solution in any one of Claims 1-7, Comprising: A copper ion, a copper ion complexing agent, a reducing agent, pH adjuster, 1st type additive, 2nd type When plating is continuously performed in a plating solution containing an additive and a third type additive, the concentration of the first type additive is 0.01 to 100 mg / L, and the concentration of the second type additive is 0.01 to 100 mg. Electroless copper characterized by supplementing the first type additive, the second type additive, and the third type additive so that the concentration of the third type additive is 100 mg / L or more. Plating solution management method.   In an electroless copper plating solution containing a copper ion, a copper ion complexing agent, a reducing agent and a pH adjusting agent, the reducing agent contains glyoxylic acid or a salt thereof, and the concentration thereof is 8 times or more of the copper ion concentration, And the said complexing agent contains tartaric acid or its salt, The density | concentration is 6 times or less of a copper ion density | concentration, The electroless copper plating solution characterized by the above-mentioned. In an electroless copper plating solution containing copper ions, a complexing agent of copper ions, a reducing agent and a pH adjusting agent, the reducing agent contains glyoxylic acid or a salt thereof, and the potential E (V of copper in the electroless copper plating solution) vs. SHE) is, by _{(E 0 -0.0001984 × T × pH} ) (E 0 is the standard redox potential of _{2Cu + H 2 O → Cu 2} O + 2H + + 2e, T denotes the absolute temperature of the plating solution) The ratio of the copper ion concentration with respect to the said glyoxylic acid is adjusted so that it may become below the calculated | required value, The electroless copper plating solution characterized by the above-mentioned.   The electroless copper plating solution according to claim 10, wherein the complexing agent contains tartaric acid or a salt thereof.   The electroless copper plating according to claim 10 or 11, wherein the concentration of the reducing agent is at least one of 8 times or more of the copper ion concentration and the concentration of the complexing agent is 6 times or less of the copper ion concentration. liquid. In an electroless copper plating method in which plating is performed in a plating bath containing copper ions, a copper ion complexing agent, a reducing agent and a pH adjusting agent, the reducing agent contains glyoxylic acid or a salt thereof, and the concentration thereof is a copper ion concentration. The copper ion and the reducing agent are replenished so that the complexing agent contains tartaric acid or a salt thereof and the concentration of the complexing agent is 6 times or less of the copper ion concentration. A characteristic electroless copper plating solution management method. In the electroless copper plating method in which plating is performed in a plating bath containing copper ions, a copper ion complexing agent, a reducing agent and a pH adjusting agent, the complexing agent contains tartaric acid or a salt thereof, and the concentration thereof is a copper ion concentration. six times or less, and wherein the reducing agent comprises a glyoxylic acid or a salt thereof, said reducing agent When the concentration falls below 7 times the copper ion concentration to 10 to 20 times its concentration the copper ion concentration A method for managing an electroless copper plating solution, characterized by comprising: In the electroless copper plating method in which plating is performed in a copper plating bath containing copper ions, a copper ion complexing agent, a reducing agent and a pH adjusting agent, the reducing agent includes glyoxylic acid and a salt thereof, and the copper plating solution The copper potential E (V vs. SHE) is E ₀ -0.0001984 × T × pH (E ₀ is the standard redox potential of 2Cu + H ₂ O → Cu ₂ O + 2H ⁺ + 2e, T is the absolute value of the plating solution) The copper ion, the reducing agent, and the pH adjusting agent are replenished so as to be equal to or lower than the value obtained by (indicating temperature).   The concentration of the reducing agent is 8 times or more of the copper ion concentration, the complexing agent contains tartaric acid or a salt thereof, and the concentration of the copper ion and the reducing agent is 6 times or less of the copper ion concentration. The electroless copper plating solution management method according to claim 15, wherein replenishment is performed.   The concentration of the reducing agent is at least 8 times the copper ion concentration, or the complexing agent contains tartaric acid or a salt thereof, and has at least one condition that the concentration is not more than 6 times the copper ion concentration. And the temperature of the said plating solution during plating shall be 50 degrees C or less, The electroless copper plating solution management method of Claim 15 characterized by the above-mentioned.   In the electroless copper plating method in which plating is performed in a plating bath containing copper ions, a copper ion complexing agent, a reducing agent and a pH adjusting agent, the reducing agent in the plating contains glyoxylic acid or a salt thereof, and the concentration thereof is It is at least 8 times the copper ion concentration, or the reducing agent concentration is at least 8 times the copper ion concentration, and the complexing agent contains at least tartaric acid or a salt thereof, and the concentration is not more than 6 times the copper ion concentration. An electroless copper plating method characterized by having at least one of the following conditions and setting the temperature of the plating solution during plating to 50 ° C. or lower.   In an electroless copper plating apparatus for immersing a plating material in a plating tank containing a copper plating solution containing a copper ion, a copper ion complexing agent, a reducing agent and a pH adjusting agent, and electroless copper plating, the reducing agent Contains glyoxylic acid or a salt thereof, the concentration thereof is 8 times or more of the copper ion concentration, the complexing agent contains tartaric acid or a salt thereof, and the concentration thereof is 6 times or less of the copper ion concentration. An electroless copper plating apparatus comprising: a reducing agent supply means for supplying a reducing agent; and a copper ion supply means for supplying the copper ions. In the electroless copper plating apparatus for immersing the plating material in a plating tank containing a copper plating solution containing copper ions, a copper ion complexing agent, a reducing agent and a pH adjusting agent, and electroless copper plating, the reducing agent Contains glyoxylic acid or a salt thereof, and the potential E (V vs. SHE) of copper in the electroless copper plating solution is (E ₀ -0.0001984 × T × pH) (E ₀ is 2Cu + H ₂ O → Cu ₂ Reducing agent replenishing means and copper ion replenishing means for replenishing the reducing agent and copper ions such that the standard oxidation-reduction potential of O + 2H ⁺⁺ 2e, T indicates the absolute temperature of the plating solution) or less. An electroless copper plating apparatus comprising:   The reducing agent replenishing means and the copper are added so that the concentration of the reducing agent is 8 times or more of the copper ion concentration, the complexing agent contains tartaric acid or a salt thereof, and the concentration is 6 times or less of the copper ion concentration. 21. The electroless copper plating apparatus according to claim 20, further comprising ion supply means.   The concentration of the reducing agent is at least 8 times the copper ion concentration, or the complexing agent contains tartaric acid or a salt thereof, and the concentration of the reducing agent is at least 6 times the copper ion concentration. Control means for controlling the temperature of the copper plating solution during the plating to be 50 ° C. or less, and having a reducing agent supply means for supplying the reducing agent and a copper ion supply means for supplying the copper ions. The electroless copper plating apparatus according to claim 20, comprising:   In an electroless copper plating apparatus for immersing a plating material in a plating tank containing a copper plating solution containing a copper ion, a copper ion complexing agent, a reducing agent and a pH adjusting agent, and electroless copper plating, the reducing agent Contains glyoxylic acid or a salt thereof, and the concentration is at least 8 times the copper ion concentration, or the complexing agent contains tartaric acid or a salt thereof, and the concentration is at least 6 times the copper ion concentration. Having a reducing agent replenishing means for replenishing the reducing agent and a copper ion replenishing means for replenishing the copper ions so as to have one condition, and the temperature of the copper plating solution during plating is 50 ° C. or less An electroless copper plating apparatus, characterized by comprising control means for controlling as described above.

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