JP3906347B2 - Copper foil for printed circuit - Google Patents

Copper foil for printed circuit Download PDF

Info

Publication number
JP3906347B2
JP3906347B2 JP16324898A JP16324898A JP3906347B2 JP 3906347 B2 JP3906347 B2 JP 3906347B2 JP 16324898 A JP16324898 A JP 16324898A JP 16324898 A JP16324898 A JP 16324898A JP 3906347 B2 JP3906347 B2 JP 3906347B2
Authority
JP
Japan
Prior art keywords
copper foil
layer
plating
cobalt
nickel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP16324898A
Other languages
Japanese (ja)
Other versions
JPH11354901A (en
Inventor
淳志 吉岡
真一 小畠
誠 土橋
行弘 小澤
芳一 明石
泰昭 益子
正和 三橋
正人 石井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsui Mining and Smelting Co Ltd
Original Assignee
Mitsui Mining and Smelting Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsui Mining and Smelting Co Ltd filed Critical Mitsui Mining and Smelting Co Ltd
Priority to JP16324898A priority Critical patent/JP3906347B2/en
Publication of JPH11354901A publication Critical patent/JPH11354901A/en
Application granted granted Critical
Publication of JP3906347B2 publication Critical patent/JP3906347B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C23C28/321—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
    • C23C28/322—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer only coatings of metal elements only
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
    • C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
    • C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
    • C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
    • C23C28/3455—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/10—Electroplating with more than one layer of the same or of different metals
    • C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/48—After-treatment of electroplated surfaces
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/38—Electroplating: Baths therefor from solutions of copper
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/56—Electroplating: Baths therefor from solutions of alloys

Description

【０００１】
【発明の属する技術分野】
本発明は印刷回路板用銅箔に関し、詳しくは、エッチング及びスズメッキ処理時の回路、基材との密着性を保持させつつ、回路作製後の特性としてマイグレーション特性を向上させた印刷回路用銅箔に関する。
【０００２】
【従来の技術及び発明が解決しようとする課題】
印刷回路板を作成する場合、銅箔とのり基材等の印刷回路板用基材とを加熱圧着等により接着し、導体回路形成のために不要部分の銅箔を酸又はアルカリのエッチング液により除去を行う。次いで、得られた回路表面をスズメッキによって防錆及び外部との接合性確保のための処理を施す。
【０００３】
従来、銅箔の基材との接着面側は接着強度を増加させるために、粒状銅層が電着により設けられる。さらに導体回路を形成した後に起こる種々の問題点の改善のために、この上に亜鉛又は亜鉛−ニッケル合金メッキ又は銅合金メッキ、クロメート処理、シランカップリング剤・クロム化合物処理によって防錆層を形成させる（特開昭６１−１１０７９４号公報、特開平７−２３１１６１号公報等）。これらの防錆処理により改善される特性は、耐熱性、耐薬品性、耐湿性、基材との接着性といったものが挙げられる。
【０００４】
このような印刷回路用銅箔にあっては、基材と加熱圧着後に、上述のように、導体回路形成のために不要部分の銅箔を酸又はアルカリのエッチング液によって除去したり、得られた回路表面をスズメッキ液によって防錆処理を施すが、この際に、エッチング液やスズメッキ液によってメッキ皮膜が溶解し、基材と銅箔界面との間で剥離が起こるといった問題を生じる。
【０００５】
他方、特開平６−１３７４９号公報には、マイグレーションを改善する提案がなされている。ここでいうマイグレーションとは、印刷回路板の回路間や層間で電位差が生じると、湿気や水分が介在する場合、回路となる銅箔がイオン化して溶出が起こり、溶出する銅イオンが時間の経過と共に還元されて金属あるいは化合物状態となって樹枝状に成長することである。そして、これが金属等からなる基材に到達して固着すると、品質上極めて致命的な欠陥、すなわち短絡という不良の発生を招くことになる。いわゆる銅マイグレーションによる短絡の発生である。また、近年は１００℃以上の常圧高温領域で同様の現象が発生するマイグレーション（高温マイグレーション）が問題となっている。
【０００６】
このように、印刷回路板用銅箔には、エッチング及びスズメッキ処理時の回路、基材との密着性を保持させると同時に、マイグレーション特性を向上させる必要があるが、上述した従来技術においては、双方の要求特性を併せて有するものではなかった。
【０００７】
従って、本発明の目的は、エッチング及びスズメッキ処理時の回路、基材との密着性を保持させつつ、マイグレーション特性を向上させた印刷回路用銅箔を提供することにある。
【０００８】
【課題を解決するための手段】
本発明者らは検討の結果、銅箔の印刷回路板用基材との接着面側に設けられた粒状銅層の上に、亜鉛−ニッケル−コバルトからなるメッキ層を設けることによって、上記目的を達成し得ることを知見した。
【０００９】
本発明は、上記知見に基づきなされたもので、銅箔の印刷回路板用基材との接着面側に設けられた粒状銅層の上に、亜鉛−ニッケル−コバルトからなるメッキ層を有し、また該メッキ層上にクロメート防錆層を有し、さらに該クロメート層上にシランカップリング剤とクロム化合物を含む防錆層が設けられており、亜鉛−ニッケル−コバルトからなるメッキ層の析出量が１００〜１５０ｍｇ／ｍ 2 であることを特徴とする印刷回路用銅箔を提供するものである。
【００１０】
【発明の実施の形態】
以下、本発明を説明する。
図１は、本発明の印刷回路板用銅箔の構成を示す概略断面図を示す。同図において、１は銅箔、２は亜鉛−ニッケル−コバルトからなるメッキ層、３はクロメート層、４はシランカップリング剤とクロム化合物を含む防錆層をそれぞれ示す。
【００１１】
図１における銅箔１の印刷回路板用基材との接着面側には、粒状銅層（図示せず）を電着して粗面化処理し、銅箔と基材の接着性の向上を図る。銅箔への粒状銅の電着は、通常３段メッキ処理で行われ、第１段メッキで銅箔に微細構造の粒状銅を電着し、第２段で微細構造の粒状銅の脱落を防ぐためにカブセメッキし、第３段で超微細構造の粒状銅の電着を行う。また、ここに用いられる銅箔は、電解銅箔でも圧延銅箔のいずれでもよい。また、印刷回路板用基材との接着面が電解銅箔の粗面、光沢面のいずれでもよい。
【００１２】
そして、この粒状銅層により粗面化処理された上には、亜鉛−ニッケル−コバルトからなるメッキ層２を有する。このようなメッキ層２を設けることによって、エッチング及びスズメッキ処理時の回路、基材との密着性を保持させると同時に、マイグレーション特性を向上させることができる。
【００１３】
亜鉛−ニッケル−コバルトからなるメッキ層２中の各成分の含有量は、亜鉛１０ｍｇ／ｍ2以下、ニッケル２０〜３５ｍｇ／ｍ2、コバルト８０〜１００ｍｇ／ｍ2が好ましい。各成分の含有量を上記範囲とすることで、特にマイグレーション特性を維持させながら、エッチング及びメッキ液に対して皮膜溶解防止効果も良好となる。この亜鉛−ニッケル−コバルトからなるメッキ層の析出量は１００〜１５０ｍｇ／ｍ2である。
【００１４】
このような亜鉛−ニッケル−コバルトメッキからなるメッキ層を形成する際の電解液の基本組成の一例を次に示す。
Ｚｎ：０．２〜２ｇ／ｌ
Ｎｉ：０．５〜４ｇ／ｌ
Ｃｏ：０．５〜４ｇ／ｌ
Ｋ4 Ｐ2 Ｏ7 ：５０〜２００ｇ／ｌ
ｐＨ；９〜１２
液温；２０〜６０℃
【００１５】
各成分の含有量は、亜鉛、ニッケル、コバルトの各濃度比によって変えることができる。また、電流密度によっても各成分の含有量を変えることができる。マイグレーション特性は、特にコバルト含有量として８０ｍｇ／ｍ2 以上とした時、マイグレーション評価における電流値（測定開始後１０分における平均リーク電流値）を５ｍＡ以下と低く抑えることで特性を改善することができる。このことは図２〜４に示されるグラフから明らかである。図２〜４は、それぞれ亜鉛含有量、ニッケル含有量及びコバルト含有量と電流値の関係を示すグラフである。
【００１６】
次に、エッチング液による評価として、皮膜が溶解しずらかった各成分の含有量は、亜鉛１０ｍｇ／ｍ2 以下、ニッケル２０〜４０ｍｇ／ｍ2 、コバルト４０〜１００ｍｇ／ｍ2 である。
【００１７】
さらに、スズメッキ液による評価として、皮膜が溶解しずらかった各成分の含有量は、亜鉛１０ｍｇ／ｍ2 以下、ニッケル１０〜３５ｍｇ／ｍ2 、コバルト７０〜１４０ｍｇ／ｍ2 である。
【００１８】
そして、これらの適性範囲とマイグレーション特性に効果がある条件としてコバルト８０ｍｇ／ｍ2 以上の含有量ということで最適の各成分の含有量は、上述したように、亜鉛１０ｍｇ／ｍ2 以下、ニッケル２０〜３５ｍｇ／ｍ2 、コバルト８０〜１１０ｍｇ／ｍ2 である。
【００１９】
このメッキ層２の上には、メッキ層２の防錆効果を充分に得るために、クロメート層３が設けられている。
【００２０】
このクロメート処理は、電解クロメートによって行われる。処理条件の一例を次に示す。なお、この場合、ｐＨについてはアルカリ条件に調整して処理しているが、酸性条件として処理を行っても同様の効果が得られる。電解時間は１〜８秒であるが、効果に対する時間の影響は小さい。
・クロム酸；０．２〜５ｇ／ｌ
・ｐＨ；９〜１３
・電流密度；０．１〜３Ａ／ｄｍ2
【００２１】
さらに、クロメート層の上には、シランカップリング剤とクロム化合物を含む防錆層４を有し、この防錆層４において、印刷回路板用基材と接合される。
【００２２】
・シランカップリング剤；０．５〜１０ｇ／ｌ
・クロム酸；０．１〜２ｇ／ｌ
・ｐＨ；２〜１２
【００２３】
シランカップリング剤とクロム化合物を含む防錆層が設けられた本発明の印刷回路用銅箔は、水洗、乾燥された後、印刷回路板用基材と加熱圧着により接合され、銅張積層板とされ、これをエッチング、さらにはスズメッキを施すことによって印刷回路板とされる。
【００２４】
【実施例】
以下、実施例等に基づいて本発明を具体的に説明する。
【００２５】
〔実施例１〕
厚さ３５μｍの電解銅箔の印刷回路板用基材との接着面側に、接着強度増加のための粗面化処理（粒状銅層の形成）を行った。粗面化処理は、以下に示す第１〜３段メッキによって行った。
【００２６】
（第１段メッキ条件）
Ｃｕ １２ｇ／ｌ
Ｈ2 ＳＯ4 １８０ｇ／ｌ
液温 ３０℃
電流密度 ３０Ａ／ｄｍ2
電解時間 ４秒
【００２７】
第１段メッキにより形成された微細構造の電着銅の脱落を防ぐため被せ平滑メッキとして第２段メッキを行った。
【００２８】
（第２段メッキ条件）
Ｃｕ ７０ｇ／ｌ
Ｈ2 ＳＯ4 １８０ｇ／ｌ
液温 ４８℃
電流密度 ３２Ａ／ｄｍ2
電解時間 ４秒
【００２９】
第２段メッキによりカブセメッキを行った後に、超微細構造の粒状銅を電着するため第３段メッキを行った。
【００３０】
（第３段メッキ条件）
Ｃｕ：８ｇ／ｌ
Ｈ2 ＳＯ4 ：８０ｇ／ｌ
Ｃｌ：２５ｐｐｍ
電流密度：１０Ａ／ｄｍ2
電解時間：４秒
【００３１】
第１〜３段メッキにより、施された電着銅（コブ、ヒゲ処理面）の上に順次下記の条件で防錆処理を施した。
【００３２】
（亜鉛−ニッケル−コバルトメッキ浴組成）
Ｚｎ：０．５ｇ／ｌ
Ｎｉ：２ｇ／ｌ
Ｃｏ：２ｇ／ｌ
Ｋ4 Ｐ2 Ｏ7 ：１００ｇ／ｌ
ｐＨ；１０．５
【００３３】
（メッキ条件）
液温 ；４０℃
電流密度；２Ａ／ｄｍ2
電解時間；４秒
【００３４】
この条件で亜鉛−ニッケル−コバルトメッキを行い、直ちに水洗し、この面に次の条件でクロメート処理を行った。
【００３５】
ＣｒＯ3 １ｇ／ｌ
ｐＨ １２．０
電流密度 １．５Ａ／ｄｍ2
電解時間 ４秒
【００３６】
クロメート処理後の銅箔を、直ちに水洗し、この銅箔にシランカップリング剤５ｇ／ｌとクロム酸１ｇ／ｌを含有する溶液によるシランカップリング剤・クロム処理を施した。この銅箔を水洗後、乾燥して印刷回路用銅箔とした。
【００３７】
〔実施例２〜６及び比較例１〜３〕
メッキ浴の組成を変え、亜鉛、ニッケル及びコバルトの含有量を表１に示す通りとした以外は、実施例１と同様にして印刷回路用銅箔とした。
【００３８】
実施例１〜６及び比較例１〜３で得られた印刷回路用銅箔を下記方法によりエッチング簡易評価試験（Ｅｔ後）を行った。また、同様に下記方法によりスズメッキ簡易評価試験（Ｓｎ後）を行った。結果を表１に示す。
【００３９】
エッチング簡易評価試験（Ｅｔ後）は、印刷回路用銅箔に塩酸と過酸化水素水の混合液からなるエッチング液によりエッチングを行った。また、スズメッキ簡易評価試験（Ｓｎ後）は、スズを含有しない模擬液を用いて行った。これらの評価試験の評価方法は下記の通りである。
【００４０】
＜表面処理皮膜に対する残存率＞
３：残存率９８％以上
２：残存率５１％以上９８％未満
１：残存率１％以上５１％未満
【００４１】
【表１】

Figure 0003906347
【００４２】
【発明の効果】
以上説明したように、本発明の印刷回路用銅箔によって、エッチング及びスズメッキ処理時の回路、基材との密着性を保持させることができ、またマイグレーション特性を向上させることができる。
【図面の簡単な説明】
【図１】 本発明の印刷回路用銅箔の構成を示す概略断面図。
【図２】 銅箔に設けられたメッキ層中の亜鉛含有量と電流値の関係を示すグラフ。
【図３】 銅箔に設けられたメッキ層中のニッケル含有量と電流値の関係を示すグラフ。
【図４】 銅箔に設けられたメッキ層中のコバルト含有量と電流値の関係を示すグラフ。
【符号の説明】
１：銅箔
２：亜鉛−ニッケル−コバルトからなるメッキ層
３：クロメート層
４：シランカップリング剤とクロム化合物を含む防錆層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a copper foil for a printed circuit board, and more specifically, a printed circuit copper foil having improved migration characteristics as characteristics after circuit fabrication while maintaining adhesion to the circuit and substrate during etching and tin plating. About.
[0002]
[Prior art and problems to be solved by the invention]
When creating a printed circuit board, the copper foil and a printed circuit board substrate such as a paste substrate are bonded by thermocompression bonding, etc., and an unnecessary part of the copper foil is formed with an acid or alkali etching solution for forming a conductor circuit. Perform removal. Next, the surface of the obtained circuit is subjected to a process for preventing rust and securing the bonding property with the outside by tin plating.
[0003]
Conventionally, a granular copper layer is provided by electrodeposition in order to increase the adhesive strength on the adhesive surface side of the copper foil with the base material. Furthermore, in order to improve various problems that occur after the formation of the conductor circuit, a rust prevention layer is formed thereon by zinc or zinc-nickel alloy plating or copper alloy plating, chromate treatment, silane coupling agent / chromium compound treatment. (Japanese Patent Laid-Open Nos. 61-110794, 7-231161, etc.). Properties improved by these rust prevention treatments include heat resistance, chemical resistance, moisture resistance, and adhesion to a substrate.
[0004]
In such a printed circuit copper foil, after the thermocompression bonding with the base material, as described above, an unnecessary portion of the copper foil is removed with an acid or alkali etching solution to form a conductor circuit. The circuit surface is subjected to a rust prevention treatment with a tin plating solution. At this time, the plating film is dissolved by the etching solution or the tin plating solution, causing a problem that peeling occurs between the substrate and the copper foil interface.
[0005]
On the other hand, Japanese Patent Laid-Open No. 6-13749 proposes to improve migration. Migration here means that when a potential difference occurs between printed circuit board circuits or between layers, when moisture or moisture is present, the copper foil that becomes the circuit ionizes and elution occurs, and the elution of copper ions elapses over time. Along with this, it is reduced to a metal or compound state and grows in a dendritic shape. And when this reaches and adheres to a base material made of metal or the like, an extremely fatal defect in quality, that is, a failure such as a short circuit is caused. This is the occurrence of a short circuit due to so-called copper migration. In recent years, migration (high temperature migration) in which the same phenomenon occurs in a normal pressure high temperature region of 100 ° C. or higher has been a problem.
[0006]
Thus, in the copper foil for printed circuit boards, it is necessary to improve the migration characteristics at the same time as maintaining the adhesion with the circuit and the base material at the time of etching and tin plating treatment. It did not have both required characteristics together.
[0007]
Accordingly, an object of the present invention is to provide a printed circuit copper foil having improved migration characteristics while maintaining adhesion to a circuit and a substrate during etching and tin plating.
[0008]
[Means for Solving the Problems]
As a result of the study, the above object is achieved by providing a plated layer made of zinc-nickel-cobalt on the granular copper layer provided on the adhesive surface side of the copper foil with the printed circuit board substrate. It was found that can be achieved.
[0009]
This invention was made based on the said knowledge, and has a plating layer which consists of zinc-nickel-cobalt on the granular copper layer provided in the adhesion surface side with the base material for printed circuit boards of copper foil. In addition, a chromate rust preventive layer is provided on the plated layer, and further a rust preventive layer containing a silane coupling agent and a chromium compound is provided on the chromate layer, so that a plating layer made of zinc-nickel-cobalt is deposited. the amount is intended to provide a copper foil for printed circuit according to claim 100 to 150 mg / m 2 der Rukoto.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below.
FIG. 1 is a schematic cross-sectional view showing a configuration of a copper foil for a printed circuit board according to the present invention. In the figure, 1 is a copper foil, 2 is a plated layer made of zinc-nickel-cobalt, 3 is a chromate layer, and 4 is a rust preventive layer containing a silane coupling agent and a chromium compound.
[0011]
On the adhesion surface side of the copper foil 1 in FIG. 1 to the printed circuit board substrate, a granular copper layer (not shown) is electrodeposited and roughened to improve the adhesion between the copper foil and the substrate. Plan. Electrodeposition of granular copper on copper foil is usually performed by a three-step plating process. The first step of plating deposits fine-grained granular copper on the copper foil, and the second step removes fine-grained granular copper. In order to prevent this, galvanizing is performed, and electrodeposition of ultrafine grained granular copper is performed in the third stage. The copper foil used here may be either an electrolytic copper foil or a rolled copper foil. Further, the adhesive surface with the printed circuit board substrate may be either a rough surface or a glossy surface of the electrolytic copper foil.
[0012]
And it has the plating layer 2 which consists of zinc-nickel-cobalt on the roughening process by this granular copper layer. By providing such a plating layer 2, it is possible to maintain the adhesion to the circuit and the base material during etching and tin plating, and at the same time improve the migration characteristics.
[0013]
Zinc - nickel - content of each component in the plating layer 2 made of cobalt, zinc 10 mg / m 2 or less, nickel 20~35mg / m 2, cobalt 80~100mg / m 2 is preferred. By setting the content of each component in the above range, the effect of preventing dissolution of the film with respect to the etching and plating solution is improved while maintaining the migration characteristics. The zinc - nickel - precipitation amount of cobalt plated layer is Ru 100 to 150 mg / m 2 der.
[0014]
An example of the basic composition of the electrolytic solution when forming a plating layer made of such zinc-nickel-cobalt plating is shown below.
Zn: 0.2-2 g / l
Ni: 0.5-4 g / l
Co: 0.5-4 g / l
K 4 P 2 O 7 : 50 to 200 g / l
pH; 9-12
Liquid temperature: 20-60 degreeC
[0015]
The content of each component can be changed according to each concentration ratio of zinc, nickel, and cobalt. The content of each component can also be changed depending on the current density. The migration characteristics can be improved by keeping the current value in migration evaluation (average leak current value 10 minutes after the start of measurement) at 5 mA or less, especially when the cobalt content is 80 mg / m 2 or more. . This is apparent from the graphs shown in FIGS. 2-4 is a graph which shows the relationship between zinc content, nickel content, cobalt content, and an electric current value, respectively.
[0016]
Then, as the evaluation by the etchant, the content of each component coating was Zuraka' dissolve, zinc 10 mg / m 2 or less, nickel 20-40 mg / m 2, a cobalt 40~100mg / m 2.
[0017]
Furthermore, the evaluation by the tin plating solution, the content of each component coating was Zuraka' dissolve, zinc 10 mg / m 2 or less, nickel 10~35mg / m 2, a cobalt 70~140mg / m 2.
[0018]
And, as described above, the optimum content of each component is that the content of cobalt is 80 mg / m 2 or more as a condition having an effect on the suitability range and the migration characteristics, as described above, the content of zinc is 10 mg / m 2 or less, nickel 20 ˜35 mg / m 2 and cobalt 80˜110 mg / m 2 .
[0019]
A chromate layer 3 is provided on the plating layer 2 in order to sufficiently obtain the rust prevention effect of the plating layer 2.
[0020]
This chromate treatment is performed by electrolytic chromate. An example of processing conditions is shown below. In this case, the pH is adjusted to the alkaline condition for the treatment, but the same effect can be obtained even if the treatment is performed under the acidic condition. The electrolysis time is 1 to 8 seconds, but the influence of the time on the effect is small.
-Chromic acid; 0.2-5 g / l
・ PH: 9-13
・ Current density: 0.1 to 3 A / dm 2
[0021]
Furthermore, on the chromate layer, it has the rust prevention layer 4 containing a silane coupling agent and a chromium compound, and in this rust prevention layer 4, it joins with the base material for printed circuit boards.
[0022]
Silane coupling agent: 0.5 to 10 g / l
-Chromic acid; 0.1-2 g / l
-PH; 2-12
[0023]
The copper foil for printed circuit of the present invention provided with a rust-preventing layer containing a silane coupling agent and a chromium compound is washed with water and dried, and then bonded to a printed circuit board substrate by thermocompression bonding, and is a copper-clad laminate. This is etched to form a printed circuit board by tin plating.
[0024]
【Example】
Hereinafter, the present invention will be specifically described based on examples and the like.
[0025]
[Example 1]
A roughening treatment (formation of a granular copper layer) for increasing the adhesive strength was performed on the side of the adhesive surface of the 35 μm-thick electrolytic copper foil with the printed circuit board substrate. The roughening treatment was performed by first to third stage plating shown below.
[0026]
(First stage plating conditions)
Cu 12g / l
H 2 SO 4 180 g / l
Liquid temperature 30 ℃
Current density 30A / dm 2
Electrolysis time 4 seconds 【0027】
In order to prevent the fine electrodeposited copper formed by the first step plating from falling off, the second step plating was performed as a covering smooth plating.
[0028]
(Second stage plating conditions)
Cu 70g / l
H 2 SO 4 180 g / l
Liquid temperature 48 ℃
Current density 32A / dm 2
Electrolysis time 4 seconds 【0029】
After performing Kabuse plating by second-stage plating, third-stage plating was performed to electrodeposit ultrafine granular copper.
[0030]
(Third stage plating conditions)
Cu: 8 g / l
H 2 SO 4 : 80 g / l
Cl: 25 ppm
Current density: 10 A / dm 2
Electrolysis time: 4 seconds [0031]
By the first to third step plating, rust prevention treatment was sequentially performed on the applied electrodeposited copper (cobbed and bearded surface) under the following conditions.
[0032]
(Zinc-nickel-cobalt bath composition)
Zn: 0.5 g / l
Ni: 2 g / l
Co: 2 g / l
K 4 P 2 O 7 : 100 g / l
pH; 10.5
[0033]
(Plating conditions)
Liquid temperature: 40 ° C
Current density: 2 A / dm 2
Electrolysis time: 4 seconds
Zinc-nickel-cobalt plating was performed under these conditions, immediately washed with water, and chromated on the surface under the following conditions.
[0035]
CrO 3 1g / l
pH 12.0
Current density 1.5A / dm 2
Electrolysis time 4 seconds [0036]
The copper foil after the chromate treatment was immediately washed with water, and this copper foil was subjected to a silane coupling agent / chromium treatment with a solution containing 5 g / l of silane coupling agent and 1 g / l of chromic acid. This copper foil was washed with water and dried to obtain a printed circuit copper foil.
[0037]
[Examples 2-6 and Comparative Examples 1-3]
A copper foil for a printed circuit was prepared in the same manner as in Example 1 except that the composition of the plating bath was changed and the contents of zinc, nickel and cobalt were as shown in Table 1.
[0038]
The copper foil for printed circuits obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was subjected to a simple etching evaluation test (after Et) by the following method. Similarly, a tin plating simple evaluation test (after Sn) was conducted by the following method. The results are shown in Table 1.
[0039]
In the simple etching evaluation test (after Et), the copper foil for printed circuit was etched with an etching solution composed of a mixture of hydrochloric acid and hydrogen peroxide. Moreover, the tin plating simple evaluation test (after Sn) was performed using the simulation liquid which does not contain tin. The evaluation methods of these evaluation tests are as follows.
[0040]
<Remaining ratio to surface treatment film>
3: Residual rate 98% or more 2: Residual rate 51% or more and less than 98% 1: Residual rate 1% or more and less than 51%
[Table 1]
Figure 0003906347
[0042]
【The invention's effect】
As described above, the printed circuit copper foil of the present invention can maintain the adhesion to the circuit and the substrate during etching and tin plating, and can improve the migration characteristics.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a configuration of a copper foil for printed circuit according to the present invention.
FIG. 2 is a graph showing the relationship between the zinc content in a plating layer provided on a copper foil and the current value.
FIG. 3 is a graph showing the relationship between the nickel content in the plating layer provided on the copper foil and the current value.
FIG. 4 is a graph showing the relationship between the cobalt content in the plating layer provided on the copper foil and the current value.
[Explanation of symbols]
1: Copper foil 2: Plating layer made of zinc-nickel-cobalt 3: Chromate layer 4: Rust prevention layer containing silane coupling agent and chromium compound

Claims (2)

銅箔の印刷回路板用基材との接着面側に設けられた粒状銅層の上に、亜鉛−ニッケル−コバルトからなるメッキ層を有し、また該メッキ層上にクロメート防錆層を有し、さらに該クロメート層上にシランカップリング剤とクロム化合物を含む防錆層が設けられており、亜鉛−ニッケル−コバルトからなるメッキ層の析出量が１００〜１５０ｍｇ／ｍ 2 であることを特徴とする印刷回路用銅箔。A plated layer made of zinc-nickel-cobalt is provided on the granular copper layer provided on the adhesive surface side of the copper foil with the printed circuit board substrate, and a chromate rust preventive layer is provided on the plated layer. and further has anti-corrosion layer is provided containing a silane coupling agent and a chromium compound on the chromate layer, a zinc - nickel - precipitation amount of the plating layer made of cobalt and 100 to 150 mg / m 2 der Rukoto A copper foil for printed circuits. 上記亜鉛−ニッケル−コバルトからなるメッキ層中に、亜鉛が１０ｍｇ／ｍ2以下、ニッケルが２０〜３５ｍｇ／ｍ2、コバルトが８０〜１１０ｍｇ／ｍ2それぞれ含有される請求項１に記載の印刷回路用銅箔。The zinc-nickel-cobalt plating layer contains zinc of 10 mg / m 2 or less, nickel of 20 to 35 mg / m 2 , and cobalt of 80 to 110 mg / m 2, respectively. Copper foil for printed circuits.
JP16324898A 1998-06-11 1998-06-11 Copper foil for printed circuit Expired - Fee Related JP3906347B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16324898A JP3906347B2 (en) 1998-06-11 1998-06-11 Copper foil for printed circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16324898A JP3906347B2 (en) 1998-06-11 1998-06-11 Copper foil for printed circuit

Publications (2)

Publication Number Publication Date
JPH11354901A JPH11354901A (en) 1999-12-24
JP3906347B2 true JP3906347B2 (en) 2007-04-18

Family

ID=15770181

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16324898A Expired - Fee Related JP3906347B2 (en) 1998-06-11 1998-06-11 Copper foil for printed circuit

Country Status (1)

Country Link
JP (1) JP3906347B2 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3258308B2 (en) * 2000-02-03 2002-02-18 株式会社日鉱マテリアルズ Copper foil excellent in laser drilling property and method for producing the same
KR100491385B1 (en) * 2001-07-04 2005-05-24 닛꼬 긴조꾸 가꼬 가부시키가이샤 Copper alloy foil for laminated sheet
JP4379854B2 (en) * 2001-10-30 2009-12-09 日鉱金属株式会社 Surface treated copper foil
WO2003102277A1 (en) * 2002-06-04 2003-12-11 Mitsui Mining & Smelting Co.,Ltd. Surface treatment copper foil for low dielectric substrate, copper clad laminate including the same and printed wiring board
JP2004363364A (en) * 2003-06-05 2004-12-24 Hitachi Chem Co Ltd Metal surface processing method, method of manufacturing multilayer circuit substrate, method of manufacturing semiconductor chip mounting substrate, method of manufacturing semiconductor package and semiconductor package
JP2005344174A (en) * 2004-06-03 2005-12-15 Mitsui Mining & Smelting Co Ltd Surface-treated copper foil, flexible copper-clad laminate manufactured using the same, and film carrier tape
JP4757666B2 (en) * 2005-03-14 2011-08-24 新日鐵化学株式会社 Copper-clad laminate
TWI406977B (en) * 2005-03-14 2013-09-01 Nippon Steel & Sumikin Chem Co Copper clad laminate
JP4907580B2 (en) * 2008-03-25 2012-03-28 新日鐵化学株式会社 Flexible copper clad laminate

Also Published As

Publication number Publication date
JPH11354901A (en) 1999-12-24

Similar Documents

Publication Publication Date Title
JP5654581B2 (en) Copper foil for printed circuit, copper-clad laminate, printed circuit board, printed circuit and electronic equipment
EP1802183B1 (en) Ultrathin copper foil with carrier and printed circuit board using same
JP5318886B2 (en) Copper foil for printed circuit
KR101853519B1 (en) Liquid crystal polymer-copper clad laminate and copper foil used for liquid crystal polymer-copper clad laminate
JP4383863B2 (en) Copper foil with low profile bond enhancement
WO2005120139A1 (en) Surface-treated copper foil and flexible copper-clad laminate plate and film carrier tape manufactured by use of the surface-treated copper foil
JP3476264B2 (en) Copper foil for printed circuit inner layer and method of manufacturing the same
TW200533261A (en) Ultra-thin copper foil with carrier and printed wiring board using ultra-thin copper foil with carrier
JP3292774B2 (en) Copper foil for printed wiring board and method for producing the same
JPH0224037B2 (en)
US6569543B2 (en) Copper foil with low profile bond enahncement
JP3250994B2 (en) Electrolytic copper foil
JP2920083B2 (en) Copper foil for printed circuit and manufacturing method thereof
JP3906347B2 (en) Copper foil for printed circuit
JP2004263300A (en) Copper foil for fine pattern printed circuit and manufacturing method therefor
JP2005015861A (en) Copper foil and manufacturing method therefor
JPH08222857A (en) Copper foil and high-density multilayered printed circuit board using the foil for its internal-layer circuit
JP2004263296A (en) Copper foil for fine pattern printed circuit and manufacturing method therefor
TWI530591B (en) Rolled copper or copper alloy foil with roughened surface
JP2012087388A (en) Surface-treated copper foil and copper-clad laminate sheet
JP6140480B2 (en) Copper foil with carrier, method for producing copper foil with carrier, printed wiring board, printed circuit board, copper-clad laminate, and method for producing printed wiring board
JP3222002B2 (en) Copper foil for printed circuit and manufacturing method thereof
JP2739507B2 (en) Copper foil electrolytic treatment method
JP2875186B2 (en) Processing method of copper foil for printed circuit
JP3709142B2 (en) Copper foil for printed wiring board and method for producing the same

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050602

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20060919

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20061116

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20061212

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20061220

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100126

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110126

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110126

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120126

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120126

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130126

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130126

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140126

Year of fee payment: 7

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees