JP4075581B2 - Prepreg with adhesive layer, method for producing metal-clad laminate, and metal-clad laminate - Google Patents

Description

［式中、Ｘは下記一般式（３ａ）又は（３ｂ）で表される２価の基、Ｒ ^１ はアルキル基、フェニル基又は置換フェニル基、Ｒ ^２ はアルキレン基、フェニレン基又は置換フェニレン基、ｎは１〜１５の整数を示す。

但し、Ｙは、炭素数１〜３の脂肪族炭化水素基、炭素数１〜３のハロゲン化脂肪族炭化水素基、スルホニル基、エーテル基、カルボニル基又は単結合であり、複数存在するＲ ^１ 及びＲ ^２ のそれぞれは同一であっても異なっていてもよい。］
上記アミド反応性化合物は、２つ以上のエポキシ基を有する多官能エポキシ化合物であり、前記ポリアミドイミド１００重量部に対する、前記アミド反応性化合物の重量部Ｘは、前記ポリアミドイミド中のアミド基量をＡ重量％、前記アミド反応性化合物中のアミド基量をＢ重量％、前記ポリアミドイミド中のケイ素量をＣ重量％、前記アミド反応性化合物中のケイ素量をＤ重量％としたときに、以下の式（Ｉ）及び（ＩＩ）、
４≦（Ａ×１００＋Ｂ×Ｘ）／（１００＋Ｘ）≦１０・・・（Ｉ）
１≦（Ｃ×１００＋Ｄ×Ｘ）／（１００＋Ｘ）≦１５・・・（ＩＩ）
を満たし、前記接着剤層の硬化後の３０℃での弾性率が１９００〜２５００ＭＰａであることを特徴とする。
【００１３】
上記の接着剤層付きプリプレグは、上記の組成の第２の硬化性樹脂からなる接着剤層をプリプレグ上に有しているため、かかる接着剤層付きプリプレグを、金属箔に接着剤層を隣接させて加熱及び加圧することにより、導体層に表面が平滑な金属箔を用いた場合であっても、金属箔とプリプレグが強固に接着した金属張積層板を得ることができる。そして、第２の硬化性樹脂に含まれるポリアミドイミドは高い耐熱性を有していることから、接着剤層は高温に晒されてもふくれ等の異常を生じることが少ない。
【００１４】
上記プリプレグとしては、強化繊維が配されているプリプレグを用いることが好ましい。強化繊維が配されているプリプレグを用いることにより、かかる場合の接着剤層付きプリプレグを用いて得られる金属張積層板の強度を向上させることができる。
【００１５】
本発明の接着剤層付きプリプレグにおいては、上記接着剤層の厚さは３０μｍ以下であることが好ましい。接着剤層の厚さを３０μｍ以下とすることにより、金属張積層板に用いる際に生じる接着剤層のそり等の発生を大幅に低減することが可能となる。
【００１６】
上記ポリアミドイミドは、下記一般式（１）で表される芳香族ジアミン及び下記一般式（２）で表されるシロキサンジアミンを含むジアミン混合物と、無水トリメリット酸とを反応させて得られるジイミドジカルボン酸に、芳香族ジイソシアネートを反応させてなるポリアミドイミドであることが好ましい。
【化４】

【化５】

［式中、Ｘは、下記一般式（３ａ）又は（３ｂ）で表される官能基であり、Ｒ^１はアルキル基、フェニル基又は置換フェニル基、Ｒ^２はアルキレン基、フェニレン基又は置換フェニレン基、ｎは１〜１５の整数を示す。
【化６】

但し、Ｙは、炭素数１〜３の脂肪族炭化水素基、炭素数１〜３のハロゲン化脂肪族炭化水素基、スルホニル基、エーテル基、カルボニル基又は単結合であり、複数存在するＲ^１及びＲ^２のそれぞれは同一であっても異なっていてもよい。］
【００１７】
かかる反応により得られるポリアミドイミドを本発明の接着剤層付きプリプレグにおける第２の硬化性樹脂に含有させることにより、金属箔と積層体との接着性を更に向上させることができる。
【００１８】
上記アミド反応性化合物は、２つ以上のエポキシ基を有する多官能エポキシ化合物であることが好ましく、上記接着剤層の硬化後の弾性率は５００〜２５００ＭＰａであることが好ましい。かかる構成を採用することにより、接着性及び耐熱性を更に向上させることができる。
【００１９】
また本発明は、金属箔とプリプレグとをそれぞれ少なくとも一枚用いて、前記金属箔の少なくとも片面に前記プリプレグが接するように積層し、加熱及び加圧する金属張積層板の製造方法において、前記金属箔の少なくとも一枚は、粗面化処理されていない金属箔であり、少なくとも前記金属箔に隣接させて加熱及び加圧するプリプレグは、前記接着剤層が前記金属箔と接するように配置された上記本発明の接着剤層付きプリプレグであることを特徴とする金属張積層板の製造方法及びかかる製造方法により得られた金属張積層板を提供する。
【００２０】
上記の製造方法により得られた金属張積層板は、上記本発明の接着剤層付きプリプレグを用いたものであるため、金属箔とプリプレグとの接着性に優れ、また耐熱性にも優れるようになる。
【００２１】
【発明の実施の形態】
以下、本発明の好適な実施形態について説明する。
【００２２】
まず、本発明の接着剤層付きプリプレグにおけるプリプレグを構成する成分について説明する。
【００２３】
本発明の接着剤層付きプリプレグにおけるプリプレグは、強化繊維を含有しないＢステージ状態の第１の硬化性樹脂からなるプリプレグであってもよく、強化繊維を配したＢステージ状態の第１の硬化性樹脂からなるプリプレグであってもよいが、強化繊維を配したＢステージ状態の第１の硬化性樹脂からなるプリプレグであることが好ましい。
【００２４】
強化繊維を配していないＢステージ状態の第１の硬化性樹脂からなるプリプレグは、第１の硬化性樹脂をフィルム形状として半硬化状態（Ｂステージ）にすることにより得ることができ、また、強化繊維を配したＢステージ状態の第１の硬化性樹脂からなるプリプレグは、強化繊維に硬化性樹脂を含浸させた後、含浸させた樹脂を半硬化状態（Ｂステージ）にすることにより得ることができる。第１の硬化性樹脂としてはエポキシ樹脂、ポリイミド樹脂、フェノール樹脂等の熱硬化性樹脂を用いることが好ましい。強化繊維としては、Ｅガラス、Ｄガラス、Ｓガラス、Ｑガラス等からなるガラス繊維、ポリイミド、ポリエステル、テトラフルオロエチレン等からなる有機繊維、及びこれらを混合した繊維が例示できる。これらの繊維は、例えば、織布、不織布、ロービング、チョップドストランドマット、サーフェシングマット等の形状で強化繊維として用いることができる。
【００２５】
プリプレグとしては、市販のプリプレグを用いることができ、またプリプレグを複数層備えたものを用いてもよい。適用可能な市販のプリプレグとしては、エポキシ樹脂を主成分とする熱硬化性樹脂をガラス繊維織布であるガラスクロスに含浸させたプリプレグ（Ｅ−６７、Ｅ−６７９、Ｅ−６７９Ｆ、日立化成工業社製）、ポリイミドに熱硬化成分を配合した樹脂組成物をガラスクロスに含浸させたプリプレグ（ＧＥＡ−Ｉ−６７１、日立化成工業社製）が挙げられる。
【００２６】
強化繊維を配したプリプレグにおける第１の硬化性樹脂と強化繊維の配合比は、重量比で硬化性樹脂／強化繊維＝２０／８０〜８０／２０であることが好ましく、４０／６０〜６０／４０であることがより好ましい。
【００２７】
次に本発明の接着剤層付きプリプレグにおける接着剤層を構成する成分について説明する。
【００２８】
接着剤層はポリアミドイミド及びアミド反応性化合物を含む第２の硬化性樹脂から構成されるが、かかる第２の硬化性樹脂においては、ポリアミドイミド１００重量部に対する、アミド反応性化合物の重量部Ｘは、ポリアミドイミド中のアミド基量をＡ重量％、アミド反応性化合物中のアミド基量をＢ重量％、ポリアミドイミド中のケイ素量をＣ重量％、アミド反応性化合物中のケイ素量をＤ重量％としたときに、上記式（I）及び（II）を満たさなければならない。これらの式の少なくとも一方が満たされない場合は、得られる金属張積層板の接着強度及び耐熱性が不十分となる。
【００２９】
なお、アミド基量とは、アミド基を含む化合物の重量に占めるアミド基（ＣＯＮＨ）の重量％をいい、ケイ素量も同様に、アミド基を含む化合物の重量に占めるケイ素原子（Ｓｉ）の重量％をいう。
【００３０】
上記式（I）及び（II）の条件を具備する場合には、ポリアミドイミド及びアミド反応性化合物の混合物中の全アミド基量が４〜１０重量％となり、全ケイ素量が１〜１５重量％となる。
【００３１】
上記式（I）及び（II）の条件を具備するポリアミドイミドを含む第２の硬化性樹脂は、有機溶媒を用いてワニスとした場合における当該溶媒の揮発速度が速く、第２の硬化性樹脂の硬化を促進しない温度において、極めて容易に残存有機溶媒分を５重量％以下にできるという特徴を有する。また、かかる第２の硬化性樹脂を接着剤層に用いた接着剤層付きプリプレグを金属張積層板に適用することにより、金属箔との接着性及び耐熱性の優れた金属張積層板を得ることができる。これは、主に耐熱性の高いポリアミドイミド中にシロキサン構造を導入したポリアミドイミドに起因するものである。そして、上述のように式（I）及び（II）の条件を具備させることで、残存有機溶媒を低減できるので、銅箔との積層工程において有機溶媒の揮発によるふくれの発生が少なく、金属張積層板のはんだ耐熱性を向上できる。
【００３２】
上記特性をより向上させることが可能なことから、上記式（I）における（Ａ×１００＋Ｂ×Ｘ）／（１００＋Ｘ）の下限は６が好ましく、上限は８が好ましい。そして同様の観点から上記式（II）における（Ｃ×１００＋Ｄ×Ｘ）／（１００＋Ｘ）の下限は５が好ましく、上限は１０が好ましい。
【００３３】
接着剤層を構成するポリアミドイミドは、主鎖にシロキサン構造、アミド結合及びイミド結合を有するポリマーであるが、シロキサン構造とは、−ＳｉＯ−結合を有する構造をいう。なお、Ｓｉには一価の有機基が２つ結合していることが好ましい。
【００３４】
ポリアミドイミドは、例えば、上記一般式（１）で表される芳香族ジアミン及び上記一般式（２）で表されるシロキサンジアミンを含むジアミン混合物と、無水トリメリット酸と、を反応させてジイミドジカルボン酸を得、得られたジイミドジカルボン酸に芳香族ジイソシアネートを反応させて得ることができる。
【００３５】
上記一般式（１）で表される芳香族ジアミンにおけるＹ、すなわち炭素数１〜３の脂肪族炭化水素基は、−Ｃ（ＣＨ_３）_２−であることが好ましく、炭素数１〜３のハロゲン化脂肪族炭化水素基は−Ｃ（ＣＦ_３）₂−であることが好ましい。また、上記一般式（２）で表されるシロキサンジアミンにおいては、Ｒ^１は炭素数１〜６のアルキル基であることが好ましく、炭素数１〜３のアルキル基であることがより好ましく、Ｒ^２は、炭素数１〜６のアルキレン基であることが好ましく、炭素数１〜３のアルキレン基であることがより好ましい。
【００３６】
上記一般式（１）で表される芳香族ジアミンとしては、例えば、２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン（ＢＡＰＰ）、ビス［４−（３−アミノフェノキシ）フェニル］スルホン、ビス［４−（４−アミノフェノキシ）フェニル］スルホン、２，２−ビス［４−（４−アミノフェノキシ）フェニル］ヘキサフルオロプロパン、ビス［４−（４−アミノフェノキシ）フェニル］メタン、４，４’−ビス（４−アミノフェノキシ）ビフェニル、ビス［４−（４−アミノフェノキシ）フェニル］エーテル、ビス［４−（４−アミノフェノキシ）フェニル］ケトン、１，３−ビス（４−アミノフェノキシ）ベンゼン、１，４−ビス（アミノフェノキシ）ベンゼンが例示できる。
【００３７】
芳香族ジアミンとしては、下記一般式（４）で表される化合物を用いることが好ましく、ＢＡＰＰを用いることがより好ましい。なお、式中、Ｙは上記と同義である。
【化７】

【００３８】
上記一般式（２）で表されるシロキサンジアミンとしては、ジメチルシロキサン系両末端アミンを用いることが好ましく、かかる化合物はアミノ変性シリコーンオイルＸ−２２−１６１ＡＳ（アミン当量４５０）、Ｘ−２２−１６１Ａ（アミン当量８４０）、Ｘ−２２−１６１Ｂ（アミン当量１５００）（以上、信越化学工業社製）、ＢＹ１６−８５３（アミン当量６５０）、ＢＹ−１６−８５３Ｂ（アミン当量２２００）（以上、東レダウコーニングシリコーン社製）等として商業的に入手可能である。なお、これらは単独で、または組み合わせて用いることができる。
【００３９】
上述の芳香族ジアミン及びシロキサンジアミンのジアミン混合物と、無水トリメリット酸とを反応させることによりジイミドジカルボン酸を得ることができる。得られるジイミドジカルボン酸には、下記一般式（５ａ）及び下記一般式（５ｂ）で表される化合物が含まれる。
【化８】

【００４０】
式中、Ｚは、上記一般式（１）で表される化合物のアミノ基を除いた残基であり、Ｒ^１、Ｒ^２及びｎは上記と同義である。
【００４１】
芳香族ジアミン及びシロキサンジアミンを含むジアミン混合物と、無水トリメリット酸の反応においては、芳香族ジアミンのモル数をＡ、シロキサンジアミンのモル数をＢ、無水トリメリット酸のモル数をＣとすると、（Ａ＋Ｂ）／Ｃの値が１．０／２．０〜１．０／２．２となるようにして反応させることが好ましい。ＡとＢとの混合比率Ａ／Ｂは９９．９／０．１〜０／１００であることが好ましく、かかる混合比率は、Ｂのアミン当量に応じて決定することが好ましい。例えば、シロキサンジアミンのアミン当量が４００〜５００の場合、Ａ／Ｂは９９．９／０．１〜０／１００、アミン当量が８００〜１０００の場合、Ａ／Ｂは９９．９／０．１〜６０／４０、アミン当量が１５００〜１６００場合、Ａ／Ｂは９９．９／０．１〜６０／４０とすることが好ましい。Ａ、Ｂ及びＣを上記範囲内にすることにより、上記一般式（５ａ）及び（５ｂ）で表されるジイミドジカルボン酸がより生成しやすくなり、生成するポリアミドイミドにおける全アミド基量及び全ケイ素量について上記式（I）及び（II）を具備させやすくなる。
【００４２】
ジイミドジカルボン酸は、まず、芳香族ジアミン及びシロキサンジアミンを含むジアミン混合物と無水トリメリット酸とを非プロトン性極性溶媒中、５０〜９０℃で反応させた後に、水と共沸可能な芳香族炭化水素を加え、１２０〜１８０℃で更に反応させて脱水閉環反応を生じさせることにより製造することが好ましい。非プロトン性極性溶媒としては、ジメチルアセトアミド、ジメチルホルムアミド、ジメチルスルホキシド、Ｎ−メチル−２−ピロリドン、４−ブチロラクトン、スルホラン等が例示でき、Ｎ−メチル−２−ピロリドンを用いることがより好ましい。
【００４３】
また、水と共沸可能な芳香族炭化水素としては、トルエン、ベンゼン、キシレン、エチルベンゼン等が例示でき、トルエンを用いることが好ましい。かかる芳香族炭化水素は非プロトン性極性溶媒に対して、重量比で０．１〜０．５となる重量を加えることが好ましい。そして、脱水閉環反応の終了後、更に温度を約１９０℃に上昇させて水と共沸可能な芳香族炭化水素を除去しておくことが好ましい。
【００４４】
上記の反応により得られたジイミドジカルボン酸に、芳香族ジイソシアネートを反応させることにより、ポリアミドイミドを得ることができる。
【００４５】
芳香族ジイソシアネートとしては、下記一般式（６）で表される化合物を用いることができる。
【化９】

【００４６】
式中、Ｗは少なくとも１つの芳香環を有する２価の有機基であり、−Ｃ_６Ｈ_４−ＣＨ_２−Ｃ_６Ｈ_４−で表される基、トリレン基及びナフチレン基からなる群から選ばれる少なくとも１つの基であることが好ましい。
【００４７】
上記一般式（６）で表される化合物としては、４，４’−ジフェニルメタンジイソシアネート（ＭＤＩ）、２，４−トリレンジイソシアネート、２，６−トリレンジイソシアネート、ナフタレン−１，５−ジイソシアネート、２，４−トリレンダイマー等が例示できる。
【００４８】
得られるポリアミドイミドは、下記一般式（７ａ）及び下記一般式（７ｂ）で表される繰り返し単位を有する化合物である。かかる繰り返し単位は、ブロック的に結合していてもよく、ランダム的に結合していてもよい。なお、式中、Ｚ、Ｗ、Ｒ^１、Ｒ^２及びｎは上記と同義である。
【化１０】

【００４９】
ジイミドジカルボン酸と芳香族ジイソシアネートとの反応は、水と共沸可能な芳香族炭化水素を除去した後、いったん溶液を室温まで冷却させてから、芳香族ジイソシアネートを加えて、約１９０℃で２時間程度反応させることが好ましい。かかる反応においては、生成したジイミドジカルボン酸１当量に対する芳香族ジイソシアネートの添加量は１．０〜１．５当量であることが好ましく、１．１〜１．３当量であることがより好ましい。芳香族ジイソシアネートの添加量が１．０当量未満であると、得られる接着剤層の可撓性が低下する傾向があり、また１．５当量を超えても、同様に得られる接着剤層の可撓性が低下する傾向がある。
【００５０】
次に、接着剤層を構成するアミド反応性化合物について説明する。アミド反応性化合物としては、アミド基と反応を生じる官能基を備えた熱硬化性樹脂を用いることができる。熱硬化性樹脂としては、多官能エポキシ化合物、ポリイミド樹脂、不飽和ポリエステル樹脂、ポリウレタン樹脂、ビスマレイミド樹脂、トリアジン−ビスマレイミド樹脂、フェノール樹脂等が例示でき、多官能エポキシ化合物を用いることが好ましい。アミド反応性化合物として多官能エポキシ化合物を用いることにより、得られる第２の硬化性樹脂からなる接着剤層の耐熱性だけでなく機械的特性及び電気的特性を向上させることができる。
【００５１】
多官能エポキシ化合物としては２個以上のエポキシ基を有する多官能エポキシ化合物を用いることが好ましく、３個以上のエポキシ基を有する多官能エポキシ化合物を用いることがより好ましい。
【００５２】
２個以上のエポキシ基を有する多官能エポキシ化合物としては、ビスフェノールＡ、ノボラック型フェノール樹脂、オルトクレゾールノボラック型フェノール樹脂等の多価フェノールとエピクロルヒドリンとを反応させてなるエポキシ樹脂；１，４−ブタンジオール等の多価アルコールとエピクロルヒドリンとを反応させてなるエポキシ樹脂；フタル酸、ヘキサヒドロフタル酸等の多塩基酸とエピクロルヒドリンとを反応させてなるポリグリシジルエステル；アミン、アミド又は複素環式窒素塩基を有する化合物のＮ−グリシジル誘導体；脂環式エポキシ樹脂等が例示できる。
【００５３】
３個以上のグリシジル基を有する多官能エポキシ化合物としては、ＺＸ−１５４８−２（東都化成社製）、ＤＥＲ−３３１Ｌ（ダウケミカル社製ビスフェノールＡ型エポキシ樹脂）、ＹＤＣＮ−１９５（東都化成社製クレゾールノボラック型エポキシ樹脂）等が例示できる。
【００５４】
アミド反応性化合物の配合量は、アミド基と反応を生じる官能基の数に応じて決定することができ、ポリアミドイミド１００重量部に対するアミド反応性化合物の重量部Ｘは、ポリアミドイミド中のアミド基量をＡ重量％、アミド反応性化合物中のアミド基量をＢ重量％、ポリアミドイミド中のケイ素量をＣ重量％、アミド反応性化合物中のケイ素量をＤ重量％としたときに、上記の式（I）及び（II）を満たすように決定する。
【００５５】
アミド反応性化合物として多官能エポキシ化合物を用いる場合、第２の硬化性樹脂中に、更に多官能エポキシ化合物の硬化剤、硬化促進剤等を加えることが好ましい。多官能エポキシ化合物の硬化剤としては、従来公知のものを用いることができ、例えば、ジシアンジアミド、ジアミノジフェニルメタン、グアニル尿素等のアミン類；イミダゾール類；ヒドロキノン、レゾルシノール、ビスフェノールＡ及びこれらのハロゲン化物、ノボラック型フェノール樹脂、レゾール型フェノール樹脂等の多官能フェノール類；無水フタル酸、ベンゾフェノンテトラカルボン酸二無水物、メチルハイミック酸等の酸無水物類等が挙げられ、また硬化促進剤としては、アルキル基置換イミダゾール、ベンゾイミダゾール等のイミダゾール類が挙げられる。
【００５６】
上記の硬化剤の配合量は、多官能エポキシ化合物におけるエポキシ当量に応じて決定することができ、例えば硬化剤としてアミン化合物を用いる場合、アミンの活性水素の当量と、多官能エポキシ化合物のエポキシ当量が等しくなるように配合する。また、硬化剤として多官能フェノール類又は酸無水物類を用いる場合、配合量は、多官能エポキシ化合物１当量に対して、フェノール性水酸基又はカルボキシル基が０．６〜１．２当量となるようにすることが好ましい。硬化促進剤を用いる場合は、硬化促進剤の配合量は多官能エポキシ化合物１００重量部に対して、０．００１〜１０重量部であることが好ましい。これらの硬化剤又は硬化促進剤の配合量が上記範囲より少ない場合は多官能エポキシ化合物の硬化が不充分となり、第２の硬化性樹脂の硬化後のガラス転移温度が低下する傾向があり、多い場合は残存の硬化剤又は硬化促進剤により第２の硬化性樹脂の硬化後の電気的特性が低下する傾向がある。
【００５７】
第２の硬化性樹脂中には、更に、硬化を阻害しない範囲で、充填剤、カップリング剤、難燃剤等をその他の成分として添加することができる。
【００５８】
次に、本発明の接着剤層付きプリプレグの構成について、図面を参照しつつ、好適な実施形態を説明する。
【００５９】
図１は本発明の接着剤層付きプリプレグの一実施形態を示す断面図である。図１に示す接着剤層付きプリプレグ１は、プリプレグ２と、プリプレグ２上に形成されたポリアミドイミド及びアミド反応性化合物を含む第２の硬化性樹脂からなる接着剤層４とを備えている。ここで、プリプレグ２における第１の硬化性樹脂と、接着剤層４を構成する第２の硬化性樹脂は、同一であってもよく、異なっていてもよいが、異なることが好ましい。
【００６０】
接着剤層付きプリプレグ１においては、プリプレグ２の厚さは、２０〜２５０μｍであることが好ましい。また、接着剤層の厚さは３０μｍ以下とすることが好ましく、５〜２０μｍとすることがより好ましい。接着剤層の厚さを３０μｍ以下とすることにより、接着剤層付きプリプレグを金属張積層板に用いた際に生じるそりを大幅に低減することが可能となる。そして、接着剤層の硬化後の弾性率は５００〜２５００ＭＰａであることが好ましく、８００〜１５００ＭＰａであることがより好ましい。接着剤層の硬化後の弾性率を上記範囲内とすることにより、接着性及び耐熱性が更に優れるようになる。
【００６１】
かかる接着剤層付きプリプレグ１は、例えば、以下のようにして得ることができる。すなわち、Ｂステージ状態の第１の硬化性樹脂を含むプリプレグ上に、第２の硬化性樹脂を積層し接着剤層とする製造方法であって、硬化が完結しないようにプリプレグ及び第２の硬化性樹脂を加熱しつつ、プリプレグ上に第２の硬化性樹脂を積層することにより得ることができる。
【００６２】
第２の硬化性樹脂は、公知の加熱手段（温風加熱、赤外線加熱、加熱圧着等）を用いて、加熱された状態でプリプレグ上に積層するが、かかる積層時には、プリプレグ及び第２の硬化性樹脂の両方の硬化が完結しないように加熱を行うことが好ましい。プリプレグに積層する接着剤層は、第２の硬化性樹脂を硬化が完結しないようにフィルム状にしたフィルム状硬化性樹脂とし、それを積層することが好ましい。
【００６３】
上記のフィルム状硬化性樹脂を用いた接着剤層付きプリプレグの作製方法は、具体的には次のようにして実施することができる。すなわち、まず、離型性の支持体上に上述の第２の硬化性樹脂からなる接着剤層を形成させて接着剤層付きフィルムを得る。次にこの接着剤層付きフィルムの接着剤層がプリプレグに接するように積層させ、プリプレグが完全に硬化しない程度に加熱及び加圧を行う。そして積層後、上記支持体を剥離することにより接着剤層付きプリプレグを得ることができる。
【００６４】
離型性の支持体としては、ポリエチレンテレフタレートやアルミ箔等が例示でき、これらの表面に離型処理を施したものがより好適である。特に、厚さ３０μｍ〜２００μｍのポリエチレンテレフタレートに離型処理を施したものを用いることが好ましい。
【００６５】
支持体上に接着剤層を形成させる方法としては、第２の硬化性樹脂を支持体上に塗布する方法が挙げられ、かかる塗布は、第２の硬化性樹脂を有機溶媒中に溶解又は分散させたワニスの状態で行うことが好ましい。かかるワニスに用いる有機溶媒としては、ジメチルアセトアミド、ジメチルホルムアミド、ジメチルスルホキシド、Ｎ−メチル−２−ピロリドン、γ−ブチロラクトン、スルホラン、シクロヘキサノン等が挙げられる。
【００６６】
接着剤層付きフィルムをプリプレグに積層させる方法としては、例えばロールラミネートによる方法が挙げられる。すなわち接着剤層付きフィルムの接着剤層がプリプレグに接するように重ね、加熱されたロールの間を加圧しながら通過させることにより積層させる。かかる方法におけるロールの温度は１５０℃以下であることが好ましく、８０〜１３０℃であることがより好ましい。ロールの温度が１５０℃以上である場合、第２の硬化性樹脂の硬化が過度に進行してしまう場合があり、また支持体の剥離が困難となる傾向がある。
【００６７】
次に本発明の金属張積層板の製造方法について、図２を参照しつつ、好適な実施形態を説明する。
【００６８】
図２（ａ）は、２枚の粗面化処理されていない金属箔２２と、３枚の積層体形成用プリプレグ１０と、２枚の接着剤層付きプリプレグ１とを積層する工程を模式的に示す断面図である。同工程においては、３枚の積層体形成用プリプレグ１０を互いに隣接するように積層し、積層された積層体形成用プリプレグ１０の上面と下面に、接着剤層付きプリプレグ１を介して金属箔２２を積層する。この場合において、接着剤層付きプリプレグ１における接着剤層４は、金属箔２２と接するように配置する。
【００６９】
金属箔２２としては、銅箔やアルミニウム箔等の金属箔を用いることができ、厚さは５〜２００μｍであることが好ましい。また、厚さ０．５〜１５μｍの銅箔層と厚さ１０〜３００μｍの銅箔層の間に、ニッケル、ニッケル−リン、ニッケル−スズ合金、ニッケル−鉄合金、鉛、鉛−スズ合金等からなる中間層を設けた３層構造の複合箔や、アルミニウムと銅箔を複合した２層構造の複合箔を用いることもできる。金属箔２２の表面粗さはＲｚ＝５μｍ以下であることが好ましく、Ｒｚ＝２μｍ以下であることがより好ましい。なお、Ｒｚは、ＪＩＳ Ｂ ０６０１に規定された十点平均粗さをいう。
【００７０】
上述のようにして積層が終了した後に、全体を加熱及び加圧することにより、金属張積層板を得ることができる。図２（ｂ）は、得られた金属張積層板３０を模式的に示す断面図である。同図に示す金属張積層板３０は、積層体形成用プリプレグ１０の硬化物である積層体形成用プリプレグ硬化物２０の３層を中心層として、この上面及び下面に、接着剤層付きプリプレグ１の硬化物（プリプレグ硬化物１２と接着剤層硬化物１４とから構成される。）と金属箔２２とがこの順に積層された構成を有している。
【００７１】
なお、積層及び硬化は、真空プレス等を用いて行うことができ、硬化の際の温度は、１５０〜２８０℃であることが好ましく、１８０〜２５０℃であることがより好ましい。また圧力は０．５〜２０ＭＰａであることが好ましく、１〜８ＭＰａであることがより好ましい。
【００７２】
金属張積層板３０においては、金属箔２２が接着剤層硬化物１４を介してプリプレグ硬化物１２に接着され、また硬化によりプリプレグ硬化物１２と積層体形成用プリプレグ硬化物２０が一体化され積層体を形成していることから、金属箔２２は金属張積層板３０において上記積層体と強固に接着しており、金属張積層板３０に微細な配線パターンを形成させた場合においても、金属箔２２からなる導体層の剥離を生じることが極めて少なくなる。また、接着剤層硬化物１４は、本発明の接着剤層付きプリプレグ１における接着剤層４の硬化物であるため、高い耐熱性を有しており、高温に晒されたときにふくれ等の発生が大幅に低減される。
【００７３】
【実施例】
以下、実施例により本発明を更に詳細に説明するが、本発明はこれらの実施例に限定されるものではない。
【００７４】
［ポリアミドイミドの合成］
（合成例１）
還流冷却器を連結したコック付き２５ｍＬの水分定量受器、温度計、攪拌器を備えた１Ｌのセパラブルフラスコに、芳香族ジアミンとして２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン（ＢＡＰＰ）４３．１ｇ（０．１０５ｍｏｌ）、シロキサンジアミンとして反応性シリコンオイルＫＦ８０１０（信越化学社製、アミン当量４４５）４０．１ｇ（０．０４５ｍｏｌ）、無水トリメリット酸（ＴＭＡ）６０．５ｇ（０．３１５ｍｏｌ）、非プロトン性極性溶媒としてＮ−メチル−２−ピロリドン（ＮＭＰ）４４０ｇを入れ、８０℃で３０分間攪拌した。
【００７５】
攪拌終了後、水と共沸可能な芳香族炭化水素としてトルエン１００ｍＬを加え、温度を１６０℃に上昇させて２時間還流させた。水分定量受器に水が約５．４ｍＬ以上たまり、水の留出が見られなくなっていることを確認した後、水分定量受器中の水を除去しながら温度を１９０℃まで上昇させ、トルエンを除去した。
【００７６】
フラスコの溶液を室温まで戻した後、芳香族イソシアネートとして４，４’−ジフェニルメタンジイイソシアネート（ＭＤＩ）４５．１ｇ（０．１８ｍｏｌ）を加え、温度を１９０℃に上昇させて２時間反応させ、アミド基量８．１重量％、ケイ素量６．９重量％のポリアミドイミドのＮＭＰ溶液を得た。
【００７７】
（合成例２）
還流冷却器を連結したコック付き２５ｍＬの水分定量受器、温度計、攪拌器を備えた１Ｌのセパラブルフラスコに、芳香族ジアミンとしてＢＡＰＰ４１．１ｇ（０．１０ｍｏｌ）、シロキサンジアミンとして反応性シリコンオイルＫＦ８０１０の９０．０ｇ（０．１０ｍｏｌ）、ＴＭＡ８０．７ｇ（０．４２ｍｏｌ）、非プロトン性極性溶媒としてＮＭＰ５０５ｇを入れ、８０℃で３０分間攪拌した。
【００７８】
攪拌終了後、水と共沸可能な芳香族炭化水素としてトルエン１００ｍＬを加え、温度を１６０℃に上昇させて２時間還流させた。水分定量受器に水が約７．２ｍＬ以上たまり、水の留出が見られなくなっていることを確認した後、水分定量受器中の水を除去しながら温度を１９０℃まで上昇させ、トルエンを除去した。
【００７９】
フラスコの溶液を室温まで戻した後、芳香族イソシアネートとしてＭＤＩ６０．１ｇ（０．２４ｍｏｌ）を加え、温度を１９０℃に上昇させて２時間反応させ、アミド基量７．４重量％、ケイ素量１０．９重量％のポリアミドイミドのＮＭＰ溶液を得た。
【００８０】
（合成例３）
還流冷却器を連結したコック付き２５ｍＬの水分定量受器、温度計、攪拌器を備えた１Ｌのセパラブルフラスコに、芳香族ジアミンとしてＢＡＰＰ５５．４ｇ（０．１３５ｍｏｌ）、シロキサンジアミンとして反応性シリコンオイルＸ−２２−１６１Ｂ（信越化学工業社製、アミン当量１５６０）４６．８ｇ（０．０１５ｍｏｌ）、ＴＭＡ６０．５ｇ（０．３１５ｍｏｌ）、非プロトン性極性溶媒としてＮＭＰ４８５ｇを入れ、８０℃で３０分間攪拌した。
【００８１】
攪拌終了後、水と共沸可能な芳香族炭化水素としてトルエン１００ｍＬを加え、温度を１６０℃に上昇させて２時間還流させた。水分定量受器に水が約５．４ｍＬ以上たまり、水の留出が見られなくなっていることを確認した後、水分定量受器中の水を除去しながら温度を１９０℃まで上昇させ、トルエンを除去した。
【００８２】
フラスコの溶液を室温まで戻した後、芳香族イソシアネートとしてＭＤＩ４５．１ｇ（０．１８ｍｏｌ）を加え、温度を１９０℃に上昇させて２時間反応させ、アミド基量７．２重量％、ケイ素量９．０重量％のポリアミドイミドのＮＭＰ溶液を得た。
【００８３】
（比較合成例１）
還流冷却器を連結したコック付き２５ｍＬの水分定量受器、温度計、攪拌器を備えた２Ｌのセパラブルフラスコに、芳香族ジアミンとしてＢＡＰＰ２４．６ｇ（０．０６ｍｏｌ）、シロキサンジアミンとして反応性シリコンオイルＸ−２２−１６１Ａ（信越化学工業社製、アミン当量８０５）２２５．４ｇ（０．１４ｍｏｌ）、ＴＭＡ８０．７ｇ（０．４２ｍｏｌ）、非プロトン性極性溶媒としてＮＭＰ７２５ｇを入れ、８０℃で３０分間攪拌した。
【００８４】
攪拌終了後、水と共沸可能な芳香族炭化水素としてトルエン１５０ｍＬを加え、温度を１６０℃に上昇させて２時間還流させた。水分定量受器に水が約７．２ｍＬ以上たまり、水の留出が見られなくなっていることを確認した後、水分定量受器中の水を除去しながら温度を１９０℃まで上昇させ、トルエンを除去した。
【００８５】
フラスコの溶液を室温まで戻した後、芳香族イソシアネートとしてＭＤＩ６０．１ｇ（０．２４ｍｏｌ）を加え、温度を１９０℃に上昇させて２時間反応させ、アミド基量４．９重量％、ケイ素量２１．７重量％のポリアミドイミドのＮＭＰ溶液を得た。
【００８６】
［第２の硬化性樹脂の調製］
（調製例１）
合成例１で得られたポリアミドイミドのＮＭＰ溶液３００ｇ（固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＺＸ−１５４８−２（東都化成社製、リン含有多官能エポキシ樹脂）２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．２ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量７．３重量％、全ケイ素量６．３重量％の第２の硬化性樹脂のワニスを得た。
【００８７】
（調製例２）
合成例１で得られたポリアミドイミドのＮＭＰ溶液２６７ｇ（固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＺＸ−１５４８−２の４０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．２ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量６．４重量％、全ケイ素量５．６重量％の第２の硬化性樹脂のワニスを得た。
【００８８】
（調製例３）
合成例１で得られたポリアミドイミドのＮＭＰ溶液３００ｇ（固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＤＥＲ−３３１Ｌ（ダウケミカル社製、ビスフェノールＡ型エポキシ樹脂）２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．２ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量７．３重量％、全ケイ素量６．３重量％の第２の硬化性樹脂のワニスを得た。
【００８９】
（調製例４）
合成例１で得られたポリアミドイミドのＮＭＰ溶液３００ｇ（固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＹＤＣＮ−１９５（東都化成社製、クレゾールノボラック型エポキシ樹脂）２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．２ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量７．３重量％、全ケイ素量６．３重量％の第２の硬化性樹脂のワニスを得た。
【００９０】
（調製例５）
合成例２で得られたポリアミドイミドのＮＭＰ溶液３００ｇ（固形分３５重量％）、アミド反応性化合物としてエポキシ樹脂であるＺＸ−１５４８−２の２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．３ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量６．５重量％、全ケイ素量９．８重量％の第２の硬化性樹脂のワニスを得た。
【００９１】
（調製例６）
合成例３で得られたポリアミドイミドのＮＭＰ溶液３００ｇ（固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＺＸ−１５４８−２の２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．３ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量４．４重量％、全ケイ素量８．１重量％の第２の硬化性樹脂のワニスを得た。
【００９２】
（比較調製例１）
比較合成例１で得られたポリアミドイミドのＮＭＰ溶液３００ｇ（樹脂固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＺＸ−１５４８−２の２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール０．３ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量３．２重量％、全ケイ素量１９．５重量％の第２の硬化性樹脂のワニスを得た。
【００９３】
（比較調製例２）
合成例１で得られたポリアミドイミドのＮＭＰ溶液１３３ｇ（樹脂固形分３０重量％）、アミド反応性化合物としてエポキシ樹脂であるＺＸ−１５４８−２の１２０ｇ（樹脂固形分５０重量％のジメチルアセトアミド溶液）、２−エチル−４−メチルイミダゾール１．２ｇを配合し、組成物が均一になるまで約１時間攪拌した後、脱泡のため２４時間室温で静置して、全アミド基量２．０重量％、全ケイ素量２．８重量％の第２の硬化性樹脂のワニスを得た。
【００９４】
［接着剤層付きプリプレグの作製］
（実施例１）
調製例１で得られた第２の硬化性樹脂のワニスを、厚さ５０μｍのポリエチレンテレフタレートフィルム（ＰＥＴフィルム、ピューレックス、帝人社製）に、接着剤層の乾燥後の厚さが１５μｍとなるように塗布し、１３０℃で２０分間加熱、乾燥することにより、揮発成分を５〜７重量％含む接着剤層付きフィルムを得た。
【００９５】
次に、得られた接着剤層付きフィルムを、接着剤層が接触するようにプリプレグ（ＧＥＡ−Ｉ−６７１、日立化成工業社製）上に重ねて、温度１２０℃、速度０．２ｍ／分の条件でホットロールラミネータによりラミネートを行った後、ＰＥＴフィルムを剥離して、プリプレグ上に接着剤層が形成された実施例１の接着剤層付きプリプレグを得た。
【００９６】
（実施例２〜６、比較例１〜２）
調製例１で得られた第２の硬化性樹脂のワニスに替えて調製例２〜６、比較調整例１〜２の第２の硬化性樹脂のワニスを用いた以外は、実施例１と同様にして実施例２〜６、比較例１〜２の接着剤層付きプリプレグを得た。なお、調製例２〜６の第２の硬化性樹脂のワニスを用いた場合が実施例２〜６に、比較調整例１〜２の第２の硬化性樹脂のワニスを用いた場合が比較例１〜２にそれぞれ該当する。
【００９７】
（実施例７〜１１）
調製例１で得られた第２の硬化性樹脂のワニスを、接着剤層の乾燥後の厚さが５、１０、２０、３０、５０μｍとなるように塗布した以外は、実施例１と同様にして実施例７〜１１のプリプレグを得た。なお、接着剤層の乾燥後の厚さを５、１０、２０、３０、５０μｍとしたものがそれぞれ実施例７、８、９、１０、１１に該当する。
【００９８】
［接着強度、はんだ耐熱性及び弾性率の測定］
実施例１〜６、比較例１〜２の接着剤層付きプリプレグを、３枚のプリプレグ（ＧＥＡ−Ｉ−６７１）を積層した積層体の両面にプリプレグが接触するようにして積層した後、最外層両面の接着剤層にそれぞれ表面粗さの異なる銅箔であるＦ０−ＷＳ−１２（古河電工社製、Ｒｚ＝１．８μｍ）、ＳＬＰ−１２（日本電解社製）の光沢面（Ｒｚ＝２．０μｍ）又はＧＴＳ−１２（古河サーキットフォイル社製、Ｒｚ＝８．０μｍ）を積層させ、真空プレスを用いて２３０℃、９０分、４．０ＭＰａの条件でプレスを行うことにより金属張積層板を得た。
【００９９】
得られたそれぞれの金属張積層板における銅箔を、それぞれ９０度方向に引き剥がす際の引き剥がし強さ（９０°剥離強さ、ＪＩＳ Ｃ６４８１に準拠）を測定することにより接着強度の測定を行った。
【０１００】
次に、上記でＲｚ＝１．８μｍの銅箔を用いて得られた金属張積層板を、２０ｍｍ×２０ｍｍに切断したものをはんだ耐熱性試験用の試料とし、この試料を２６０℃及び２８８℃のはんだ浴にそれぞれ浸漬して、ふくれ又は金属箔の剥がれが生じていないかを目視により確認してはんだ耐熱性の評価を行った。なお、はんだ耐熱性の評価は、はんだ浴に試料を浸漬してからふくれ又は金属箔の剥がれが見られるまでの時間を測定し、得られた時間を測定値とした。
【０１０１】
また、接着剤層を有していないプリプレグを用いた場合との比較を行うため、参考例１として５枚のプリプレグ（ＧＥＡ−Ｉ−６７１）を積層した積層体の両面に、Ｒｚ＝１．８μｍの銅箔を積層させ、真空プレスを用いて２３０℃、９０分、４．０ＭＰａの条件でプレスを行って得られた金属張積層板を用いて上記と同様に接着強度及びはんだ耐熱性の測定を行った。
【０１０２】
更に、接着剤層の硬化後の弾性率を測定するため、以下の試験を行った。まず、調製例１〜６、比較調製例１〜２で得られた第２の硬化性樹脂のワニスを厚さ５０μｍのポリエチレンテレフタレートフィルム（ＰＥＴフィルム）に乾燥後の厚さが８０μｍとなるようにそれぞれ塗布し、１３０℃で３０分間加熱して溶媒を揮発させるとともに硬化させた。硬化後、ＰＥＴフィルムを剥離して第２の硬化性樹脂の硬化物を得、得られた第２の硬化性樹脂の硬化物をＳＵＳ製の枠に挟んで、更に２３０℃で９０分の加熱を行い、厚さが８０μｍであるフィルム状硬化性樹脂を得た。そして、得られたフィルム状硬化性樹脂の３０℃における弾性率を動的粘弾性測定装置（レオロジー社製）を用いて測定した。
【０１０３】
上記接着強度及びはんだ耐熱性の測定により得られた結果を合わせて表１に示す。また、弾性率の測定結果を、同様の第２の硬化性樹脂のワニスを用いたプリプレグの欄に記載した。
【表１】

【０１０４】
表１に示すように、実施例１〜６の接着剤層付きプリプレグを用いた金属張積層板では、いずれの表面粗さを有する銅箔であっても０．８〜１．４ｋＮ／ｍの接着強度を示し、また、いずれの温度のはんだ浴に浸漬しても、３分以上ふくれ又は金属箔の剥がれ等の異常の発生は見られなかったのに対し、比較例１〜２の接着剤層付きプリプレグを用いた金属張積層板及び参考例１では、０．２〜０．６ｋＮ／ｍの接着強度を示し、また、いずれもはんだ浴に浸漬してから３０秒以内でふくれ又は金属箔の剥がれが見られた。
【０１０５】
［接着剤層の厚さによる影響の評価］
実施例７〜１１の接着剤層付きプリプレグを、その接着剤層が接触するようにして３枚のプリプレグを積層した積層体の片面に積層させた後、接着剤層に銅箔としてＦ０−ＷＳ−１２（Ｒｚ＝１．８μｍ）又はＳＬＰ−１２の光沢面（Ｒｚ＝２．０μｍ）を積層させ、真空プレスを用いて２３０℃、９０分、４．０ＭＰａの条件でプレスを行うことにより金属張積層板を得た。
【０１０６】
得られた金属張積層板をそれぞれ用い、そりの発生の確認及び接着強度の測定を行った。なお、そりの発生は、金属張積層板にそりが発生しているか否かを目視により確認し、接着強度の測定は上述の方法と同様に行った。
【０１０７】
得られたそりの発生の確認及び接着強度の測定の結果をまとめて表２に示す。なお、表２においては、そりの発生の見られなかったものを○で示し、そりの発生の見られたものを×で示した。
【表２】

【０１０８】
表２に示すように、いずれの接着剤層付きプリプレグを用いた金属張積層板でも、０．６〜１．１ｋＮ／ｍの接着強度を示したが、接着剤層の厚さが５０μｍである接着剤層付きプリプレグを用いた金属張積層板は、銅箔を内側にするように表面にそりが発生した。
【０１０９】
［回路形成性の評価］
実施例１、６及び比較例１の接着剤層付きプリプレグを、そのプリプレグが接触するようにして４枚のプリプレグを積層した積層体の両面に積層した後、一方の接着剤層にＳＬＰ−１００（日本電解社製）を積層し、もう一方の接着剤層に表面粗さの異なる銅箔（Ｒｚ＝１．８μｍ、Ｒｚ＝２．０μｍ又はＲｚ＝８．０μｍ）をそれぞれ積層させ、真空プレスを用いて２３０℃、９０分、４．０ＭＰａの条件でプレスを行うことにより金属張積層板を得た。
【０１１０】
得られた金属張積層板をそれぞれ用い、金属張積層板における一方の面に存在するＳＬＰ−１００表面に全面レジストを形成し、また、他方の面に存在するそれぞれ表面粗さの異なる銅箔上に、ライン幅／スペース幅（Ｌ／Ｓ）が、２０μｍ／２０μｍ、３０μｍ／３０μｍ、４０μｍ／４０μｍ又は５０μｍ／５０μｍである櫛型レジストパターンをそれぞれ形成した。そして、塩化第二鉄溶液を用いてエッチングを行うことにより未保護の銅箔を除去した後、レジストを剥離して配線パターンを形成させた。
【０１１１】
配線パターンが形成された金属張積層板の回路形成性の評価は、顕微鏡を用いて行い、この評価は回路形成が可能であったライン幅／スペース幅（Ｌ／Ｓ）の最小値を回路形成性の値とした。
【０１１２】
また、接着剤層を有していないプリプレグを用いた場合との比較を行うため、参考例２として５枚のプリプレグ（ＧＥＡ−Ｉ−６７１）を積層した積層体の両面に、上記と同様に銅箔を積層して得られた金属張積層板を用い、上記と同様にして回路形成性の評価を行った。
【０１１３】
得られた回路形成性の評価結果をまとめて表３に示す。
【表３】

【０１１４】
表３に示すように、実施例１又は６の接着剤層付きプリプレグを用いた金属張積層板では、比較的平滑な金属箔表面（Ｒｚ＝１．８μｍ又は２．０μｍ）を有する銅箔を用いた金属張積層板であっても、エッチング時の残銅の除去を短時間で行うことができ、ライン幅／スペース幅＝２０μｍ／２０μｍで断面形状が矩形に近い良好な配線パターンが得られた。それに対して、比較例１の接着剤層付きプリプレグを用いた金属張り積層板又は参考例２では、Ｒｚ＝１．８μｍ又は２．０μｍの銅箔を用いた場合において銅箔が一部剥離した。なお、Ｒｚ＝８．０μｍの銅箔を用いた場合は、いずれの金属張積層板でも剥離は生じなかったが、エッチング時に銅箔面上の残銅の除去に長時間を要したために、ラインの上部が細い蒲鉾型となる傾向が見られた。このため、ライン幅／スペース幅は４０μｍ／４０μｍが良好な配線パターンの得られる限界であった。
【０１１５】
【発明の効果】
以上説明したように、本発明の接着剤層付きプリプレグによれば、粗面化処理されていない金属箔を用いた場合であっても、金属箔と積層体との接着性に優れ、微細な配線パターンを形成させた場合にも導体層の剥離が生じず、なおかつ耐熱性に優れる金属張積層板を得ることが可能となる。また、本発明によれば、本発明の接着剤層付きプリプレグを用いた金属張積層板の製造方法及びかかる方法により得られた金属張積層板を提供することが可能となる。
【図面の簡単な説明】
【図１】本発明の接着剤層付きプリプレグの一実施形態を示す断面図である
【図２】（ａ）は、２枚の粗面化処理されていない金属箔２２と、３枚の積層体形成用プリプレグ１０と、２枚の接着剤層付きプリプレグ１とを積層する工程を模式的に示す断面図であり、（ｂ）は、得られた金属張積層板４０を模式的に示す断面図である。
【符号の説明】
１・・・接着剤層付きプリプレグ、２・・・プリプレグ、４・・・接着剤層、１０・・・積層体形成用プリプレグ、１２・・・プリプレグ硬化物、１４・・・接着剤層硬化物、２０・・・積層体形成用プリプレグ硬化物、２２・・・金属箔、３０・・・金属張積層板。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a prepreg with an adhesive layer, a method for producing a metal-clad laminate, and a metal-clad laminate.
[0002]
[Prior art]
Many printed circuit boards are obtained by laminating a plurality of prepregs made by impregnating a reinforcing fiber such as glass cloth with a resin having electrical insulation, and then integrating them by heating and pressing. It is used. A subtractive method is known as a method for forming a conductor layer having a wiring pattern on such a substrate. In such a method, a metal-clad laminate in which a plurality of prepregs as described above are laminated to obtain a laminate, and a metal foil is laminated and integrated on the surface (one side or both sides) is used. A wiring pattern is formed by etching the metal foil in the metal-clad laminate.
[0003]
And as an electrically insulating resin used for the metal-clad laminate, thermosetting resins such as phenol resin, epoxy resin, polyimide resin, bismaleimide-triazine resin, fluorine resin, polyphenylene ether resin, etc. Such a thermoplastic resin is used.
[0004]
Conventional metal-clad laminates have a surface roughened electrically or chemically to form a fine concavo-convex shape on the surface of the metal foil, and the prepreg as described above is formed on the concavo-convex of the metal foil. By impregnating the resin contained in the resin, an anchor effect was developed, and the adhesive force between the metal foil and the laminate was improved (for example, see Non-Patent Document 1).
[0005]
[Non-Patent Document 1]
Electronic Materials Editing Department, “High Density Printed Wiring Board Technology”, Industrial Research Committee, May 20, 1986, p. 149-157
[0006]
[Problems to be solved by the invention]
By the way, the lines of magnetic force generated in the vicinity of the current flowing in the conductor layer particularly interfere with the central portion of the conductor, so that the skin effect that current concentrates on the surface of the conductor due to such interference appears. It is known to increase. The increase in resistance due to the skin effect is more conspicuous as the surface of the conductor layer becomes rougher. Therefore, when using a roughened metal foil as in the prior art, the high frequency of the signal to be transmitted Therefore, it has become an obstacle to improve the processing speed.
[0007]
Therefore, in order to improve the processing speed, it is necessary to smooth the surface of the conductor layer. However, the anchor effect cannot be obtained by smoothing the surface of the conductor layer, and the laminate and metal foil in the metal-clad laminate can be obtained. It has been difficult to achieve both the adhesion between the laminate and the metal foil and the smoothness of the surface of the conductor layer, such as the occurrence of peeling of the conductor layer due to a decrease in the adhesion of the conductor.
[0008]
As the processing speed of electronic devices is increased, the number of MPUs to be mounted is increasing, and the number of terminals for connecting MPUs by wire bonding is also increasing. Therefore, it is necessary to cope with the increase in the number of terminals by miniaturizing the wiring pattern and reducing the terminal width. However, in the conventional metal-clad laminate, the conductor layer is peeled off from the laminate due to such miniaturization. There was a problem.
[0009]
Furthermore, as information terminal equipment is miniaturized and densified, the form of mounting a mounting component on a printed wiring board mounted thereon has shifted from a pin insertion type to a surface mounting type. The area array type represented by (grid array) has become the mainstream. A mounting component such as BGA is mounted on a substrate by a wire bonding method in which crimping is performed by heat and sound waves. In such a mounting method, the entire substrate is exposed to a high temperature of 150 ° C. or higher, and thus used for a substrate. The electrically insulating resin is required to have high heat resistance that does not cause blistering even at high temperatures.
[0010]
The present invention has been made in view of the above, and in the production of a metal-clad laminate, even when a conductor layer having a smooth surface that has not been roughened is used, the adhesion between the conductor layer and the laminate is improved. To provide a prepreg with an adhesive layer that can improve the resistance of the conductive layer without causing peeling of the conductor layer even when a fine wiring pattern is formed, and can reduce the occurrence of blistering under high-temperature conditions. With the goal. Another object of the present invention is to provide a method for producing a metal-clad laminate using such a prepreg with an adhesive layer and a metal-clad laminate obtained by such a production method.
[0011]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that the above object can be achieved by a prepreg with an adhesive layer in which a specific adhesive layer is formed on the prepreg, and completed the present invention.
[0012]
  That is, the prepreg with an adhesive layer of the present invention includes a prepreg made of a first curable resin in a B-stage state and an adhesive layer made of a second curable resin formed on the prepreg. A prepreg with an agent layer, wherein the second curable resin includes a polyamideimide having a siloxane structure in the main chain and an amide reactive compound having a functional group that causes a reaction with the amide group of the polyamideimide. ,The polyamidoimide is a diimide dicarboxylic acid obtained by reacting an aromatic diamine represented by the following general formula (1) and a diamine mixture containing a siloxane diamine represented by the following general formula (2) with trimellitic anhydride. It is a polyamide-imide obtained by reacting an aromatic diisocyanate with an acid,

[Wherein, X is a divalent group represented by the following general formula (3a) or (3b), R ¹ Is an alkyl group, a phenyl group or a substituted phenyl group, R ² Represents an alkylene group, a phenylene group or a substituted phenylene group, and n represents an integer of 1 to 15.

Y is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, a carbonyl group, or a single bond, and a plurality of R ¹ And R ² Each may be the same or different. ]
The amide reactive compound is a polyfunctional epoxy compound having two or more epoxy groups,The weight part X of the amide-reactive compound with respect to 100 parts by weight of the polyamide-imide is A weight% of the amide group in the polyamideimide, B weight% of the amide group in the amide-reactive compound, and the polyamideimide. When the amount of silicon in the mixture is C wt% and the amount of silicon in the amide reactive compound is D wt%, the following formulas (I) and (II):
  4 ≦ (A × 100 + B × X) / (100 + X) ≦ 10 (I)
  1 ≦ (C × 100 + D × X) / (100 + X) ≦ 15 (II)
And the elastic modulus at 30 ° C. after curing of the adhesive layer is 1900 to 2500 MPa.
[0013]
Since the prepreg with an adhesive layer has an adhesive layer made of the second curable resin having the above composition on the prepreg, the prepreg with an adhesive layer is adjacent to the metal foil with the adhesive layer. By heating and pressurizing, a metal-clad laminate in which the metal foil and the prepreg are firmly bonded can be obtained even when a metal foil having a smooth surface is used for the conductor layer. And since the polyamideimide contained in 2nd curable resin has high heat resistance, even if an adhesive bond layer is exposed to high temperature, it does not produce abnormality, such as blistering.
[0014]
As the prepreg, it is preferable to use a prepreg in which reinforcing fibers are arranged. By using the prepreg in which the reinforcing fibers are arranged, the strength of the metal-clad laminate obtained using the prepreg with an adhesive layer in such a case can be improved.
[0015]
In the prepreg with an adhesive layer of the present invention, the thickness of the adhesive layer is preferably 30 μm or less. By setting the thickness of the adhesive layer to 30 μm or less, it is possible to greatly reduce the occurrence of warpage of the adhesive layer and the like that occurs when used for a metal-clad laminate.
[0016]
The polyamidoimide is a diimide dicarboxylic acid obtained by reacting an aromatic diamine represented by the following general formula (1) and a diamine mixture containing a siloxane diamine represented by the following general formula (2) with trimellitic anhydride. Polyamideimide obtained by reacting an aromatic diisocyanate with an acid is preferable.
[Formula 4]

[Chemical formula 5]

[Wherein X is a functional group represented by the following general formula (3a) or (3b);¹Is an alkyl group, a phenyl group or a substituted phenyl group, R²Represents an alkylene group, a phenylene group or a substituted phenylene group, and n represents an integer of 1 to 15.
[Chemical 6]

Y is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, a carbonyl group, or a single bond, and a plurality of R¹And R²Each may be the same or different. ]
[0017]
By including the polyamideimide obtained by this reaction in the second curable resin in the prepreg with an adhesive layer of the present invention, the adhesion between the metal foil and the laminate can be further improved.
[0018]
The amide-reactive compound is preferably a polyfunctional epoxy compound having two or more epoxy groups, and the elastic modulus after curing of the adhesive layer is preferably 500 to 2500 MPa. By adopting such a configuration, the adhesiveness and heat resistance can be further improved.
[0019]
Further, the present invention provides a method for producing a metal-clad laminate in which at least one metal foil and a prepreg are used so that the prepreg is laminated on at least one surface of the metal foil, and heated and pressed. At least one of the above is a metal foil that has not been roughened, and at least the prepreg that is heated and pressed adjacent to the metal foil is arranged such that the adhesive layer is in contact with the metal foil. A method for producing a metal-clad laminate, which is a prepreg with an adhesive layer of the invention, and a metal-clad laminate obtained by the production method are provided.
[0020]
Since the metal-clad laminate obtained by the above production method uses the prepreg with an adhesive layer of the present invention, it has excellent adhesion between the metal foil and the prepreg, and also has excellent heat resistance. Become.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
[0022]
First, the component which comprises the prepreg in the prepreg with an adhesive layer of this invention is demonstrated.
[0023]
The prepreg in the prepreg with an adhesive layer of the present invention may be a prepreg made of a first curable resin in a B-stage state that does not contain reinforcing fibers, and the first curable resin in a B-stage state in which reinforcing fibers are arranged. Although it may be a prepreg made of a resin, it is preferably a prepreg made of a first curable resin in a B-stage state in which reinforcing fibers are arranged.
[0024]
The prepreg composed of the first curable resin in the B stage state in which no reinforcing fiber is arranged can be obtained by making the first curable resin into a semi-cured state (B stage) as a film shape. A prepreg composed of a first curable resin in a B-stage state in which reinforcing fibers are arranged is obtained by impregnating a curable resin into a reinforcing fiber and then making the impregnated resin into a semi-cured state (B stage). Can do. As the first curable resin, it is preferable to use a thermosetting resin such as an epoxy resin, a polyimide resin, or a phenol resin. Examples of reinforcing fibers include glass fibers made of E glass, D glass, S glass, Q glass, and the like, organic fibers made of polyimide, polyester, tetrafluoroethylene, and the like, and fibers obtained by mixing these. These fibers can be used as reinforcing fibers in the form of, for example, woven fabric, non-woven fabric, roving, chopped strand mat, and surfacing mat.
[0025]
As the prepreg, a commercially available prepreg can be used, or a prepreg having a plurality of layers of prepreg may be used. Applicable commercially available prepregs include prepregs (E-67, E-679, E-679F, Hitachi Chemical Co., Ltd.) in which a glass cloth, which is a glass fiber woven fabric, is impregnated with a thermosetting resin mainly composed of an epoxy resin. Prepreg (GEA-I-671, manufactured by Hitachi Chemical Co., Ltd.) in which a glass cloth is impregnated with a resin composition in which a thermosetting component is blended with polyimide.
[0026]
The blending ratio of the first curable resin and the reinforced fiber in the prepreg in which the reinforced fibers are arranged is preferably curable resin / reinforced fiber = 20/80 to 80/20 by weight ratio, and 40/60 to 60 / More preferably, it is 40.
[0027]
Next, the component which comprises the adhesive bond layer in the prepreg with an adhesive bond layer of this invention is demonstrated.
[0028]
The adhesive layer is composed of a second curable resin containing a polyamideimide and an amide reactive compound. In the second curable resin, the weight part X of the amide reactive compound is 100 parts by weight of the polyamideimide. The amount of amide groups in the polyamide-imide is A wt%, the amount of amide groups in the amide-reactive compound is B wt%, the amount of silicon in the polyamide-imide is C wt%, and the amount of silicon in the amide-reactive compound is D wt. %, The above formulas (I) and (II) must be satisfied. When at least one of these formulas is not satisfied, the adhesive strength and heat resistance of the resulting metal-clad laminate are insufficient.
[0029]
The amount of amide group means the weight percentage of amide group (CONH) in the weight of the compound containing amide group, and the silicon amount is the weight of silicon atom (Si) in the weight of the compound containing amide group as well. %.
[0030]
When the conditions of the above formulas (I) and (II) are satisfied, the total amount of amide groups in the mixture of polyamideimide and amide reactive compound is 4 to 10% by weight, and the total amount of silicon is 1 to 15% by weight. It becomes.
[0031]
The second curable resin containing the polyamideimide having the conditions of the above formulas (I) and (II) has a high volatilization rate of the solvent when used as a varnish using an organic solvent, and the second curable resin. In the temperature which does not accelerate | stimulate hardening of this, it has the characteristics that a residual organic solvent part can be 5 weight% or less very easily. Further, by applying a prepreg with an adhesive layer using the second curable resin as an adhesive layer to a metal-clad laminate, a metal-clad laminate having excellent adhesion to metal foil and heat resistance is obtained. be able to. This is mainly due to the polyamideimide in which the siloxane structure is introduced into the polyamideimide having high heat resistance. Since the residual organic solvent can be reduced by providing the conditions of the formulas (I) and (II) as described above, the occurrence of blistering due to volatilization of the organic solvent in the lamination process with the copper foil is small, and the metal tension is reduced. The solder heat resistance of the laminate can be improved.
[0032]
Since the above characteristics can be further improved, the lower limit of (A × 100 + B × X) / (100 + X) in formula (I) is preferably 6, and the upper limit is preferably 8. From the same viewpoint, the lower limit of (C × 100 + D × X) / (100 + X) in the above formula (II) is preferably 5, and the upper limit is preferably 10.
[0033]
The polyamideimide constituting the adhesive layer is a polymer having a siloxane structure, an amide bond and an imide bond in the main chain, and the siloxane structure refers to a structure having a —SiO— bond. Note that two monovalent organic groups are preferably bonded to Si.
[0034]
For example, the polyamideimide is obtained by reacting a diamine mixture containing the aromatic diamine represented by the general formula (1) and the siloxane diamine represented by the general formula (2) with trimellitic anhydride to obtain diimide dicarboxylic acid. An acid can be obtained and obtained by reacting the obtained diimidedicarboxylic acid with an aromatic diisocyanate.
[0035]
Y in the aromatic diamine represented by the general formula (1), that is, an aliphatic hydrocarbon group having 1 to 3 carbon atoms is represented by —C (CH₃)₂It is preferable that the halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms is —C (CF₃)₂-Is preferred. In the siloxane diamine represented by the general formula (2), R¹Is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and R²Is preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms.
[0036]
Examples of the aromatic diamine represented by the general formula (1) include 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP) and bis [4- (3-aminophenoxy) phenyl. ] Sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] methane 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ketone, 1,3-bis (4 Examples include -aminophenoxy) benzene and 1,4-bis (aminophenoxy) benzene.
[0037]
As the aromatic diamine, a compound represented by the following general formula (4) is preferably used, and BAPP is more preferably used. In the formula, Y is as defined above.
[Chemical 7]

[0038]
As the siloxane diamine represented by the general formula (2), it is preferable to use a dimethylsiloxane-based both-end amine, and these compounds are amino-modified silicone oils X-22-161AS (amine equivalent 450), X-22-161A. (Amine equivalent 840), X-22-161B (amine equivalent 1500) (above, manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-853 (amine equivalent 650), BY-16-853B (amine equivalent 2200) (above, Toray Dow (Commercially available from Corning Silicone). These can be used alone or in combination.
[0039]
Diimide dicarboxylic acid can be obtained by reacting the above diamine mixture of aromatic diamine and siloxane diamine with trimellitic anhydride. The diimide dicarboxylic acid obtained includes compounds represented by the following general formula (5a) and the following general formula (5b).
[Chemical 8]

[0040]
In the formula, Z is a residue excluding the amino group of the compound represented by the general formula (1), and R¹, R²And n are as defined above.
[0041]
In the reaction of a diamine mixture containing aromatic diamine and siloxane diamine and trimellitic anhydride, assuming that the number of moles of aromatic diamine is A, the number of moles of siloxane diamine is B, and the number of moles of trimellitic anhydride is C, The reaction is preferably carried out so that the value of (A + B) / C is 1.0 / 2.0 to 1.0 / 2.2. The mixing ratio A / B between A and B is preferably 99.9 / 0.1 to 0/100, and the mixing ratio is preferably determined according to the amine equivalent of B. For example, when the amine equivalent of siloxane diamine is 400 to 500, A / B is 99.9 / 0.1 to 0/100, and when the amine equivalent is 800 to 1000, A / B is 99.9 / 0.1. When -60/40 and amine equivalent are 1500-1600, A / B is preferably 99.9 / 0.1-60 / 40. By making A, B and C within the above ranges, the diimide dicarboxylic acid represented by the general formulas (5a) and (5b) can be more easily generated, and the total amount of amide groups and the total silicon in the generated polyamideimide It becomes easy to provide said formula (I) and (II) about quantity.
[0042]
Diimide dicarboxylic acid is an aromatic carbonization that can be azeotroped with water after reacting a diamine mixture containing aromatic diamine and siloxane diamine with trimellitic anhydride in an aprotic polar solvent at 50 to 90 ° C. It is preferable to produce by adding hydrogen and making it react further at 120-180 degreeC, and producing dehydration ring closure reaction. Examples of the aprotic polar solvent include dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, 4-butyrolactone, sulfolane and the like, and it is more preferable to use N-methyl-2-pyrrolidone.
[0043]
Examples of aromatic hydrocarbons that can be azeotroped with water include toluene, benzene, xylene, and ethylbenzene, and it is preferable to use toluene. The aromatic hydrocarbon is preferably added at a weight ratio of 0.1 to 0.5 with respect to the aprotic polar solvent. And after completion | finish of a dehydration ring closure reaction, it is preferable to raise the temperature to about 190 degreeC, and to remove the aromatic hydrocarbon which can be azeotroped with water.
[0044]
Polyamideimide can be obtained by reacting diimide dicarboxylic acid obtained by the above reaction with aromatic diisocyanate.
[0045]
As the aromatic diisocyanate, a compound represented by the following general formula (6) can be used.
[Chemical 9]

[0046]
In the formula, W is a divalent organic group having at least one aromatic ring, and —C₆H₄-CH₂-C₆H₄It is preferably at least one group selected from the group consisting of a group represented by-, a tolylene group and a naphthylene group.
[0047]
Examples of the compound represented by the general formula (6) include 4,4′-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, 2 , 4-tolylene dimer and the like.
[0048]
The obtained polyamideimide is a compound having a repeating unit represented by the following general formula (7a) and the following general formula (7b). Such repeating units may be bonded in a block manner or in a random manner. In the formula, Z, W, R¹, R²And n are as defined above.
[Chemical Formula 10]

[0049]
The reaction between diimide dicarboxylic acid and aromatic diisocyanate is carried out by removing aromatic hydrocarbons azeotropic with water, once the solution is cooled to room temperature, adding aromatic diisocyanate, and then at about 190 ° C. for 2 hours. It is preferable to react to a certain extent. In such a reaction, the amount of aromatic diisocyanate added is preferably 1.0 to 1.5 equivalents, more preferably 1.1 to 1.3 equivalents, relative to 1 equivalent of the produced diimide dicarboxylic acid. If the amount of aromatic diisocyanate added is less than 1.0 equivalent, the flexibility of the resulting adhesive layer tends to decrease, and even if it exceeds 1.5 equivalents, Flexibility tends to decrease.
[0050]
Next, the amide reactive compound constituting the adhesive layer will be described. As the amide-reactive compound, a thermosetting resin having a functional group that reacts with an amide group can be used. Examples of the thermosetting resin include polyfunctional epoxy compounds, polyimide resins, unsaturated polyester resins, polyurethane resins, bismaleimide resins, triazine-bismaleimide resins, and phenol resins, and it is preferable to use polyfunctional epoxy compounds. By using a polyfunctional epoxy compound as the amide-reactive compound, not only the heat resistance of the adhesive layer made of the second curable resin to be obtained but also the mechanical and electrical characteristics can be improved.
[0051]
As the polyfunctional epoxy compound, a polyfunctional epoxy compound having two or more epoxy groups is preferably used, and a polyfunctional epoxy compound having three or more epoxy groups is more preferably used.
[0052]
Examples of the polyfunctional epoxy compound having two or more epoxy groups include an epoxy resin obtained by reacting a polyhydric phenol such as bisphenol A, a novolac type phenol resin, or an orthocresol novolac type phenol resin with epichlorohydrin; 1,4-butane Epoxy resin formed by reacting polyhydric alcohol such as diol with epichlorohydrin; polyglycidyl ester formed by reacting polybasic acid such as phthalic acid or hexahydrophthalic acid with epichlorohydrin; amine, amide or heterocyclic nitrogen base N-glycidyl derivative of a compound having a alicyclic epoxy resin and the like.
[0053]
As polyfunctional epoxy compounds having 3 or more glycidyl groups, ZX-15548-2 (manufactured by Toto Kasei Co., Ltd.), DER-331L (bisphenol A type epoxy resin manufactured by Dow Chemical Company), YDCN-195 (manufactured by Toto Kasei Co., Ltd.) Examples thereof include a cresol novolac type epoxy resin.
[0054]
The amount of the amide-reactive compound can be determined according to the number of functional groups that react with the amide group, and the weight part X of the amide-reactive compound with respect to 100 parts by weight of the polyamide-imide is the amide group in the polyamide-imide. When the amount is A wt%, the amount of amide groups in the amide reactive compound is B wt%, the amount of silicon in the polyamideimide is C wt%, and the amount of silicon in the amide reactive compound is D wt%, the above It determines so that Formula (I) and (II) may be satisfy | filled.
[0055]
When a polyfunctional epoxy compound is used as the amide-reactive compound, it is preferable to add a polyfunctional epoxy compound curing agent, a curing accelerator, or the like to the second curable resin. As the curing agent for the polyfunctional epoxy compound, conventionally known ones can be used, for example, amines such as dicyandiamide, diaminodiphenylmethane, guanylurea; imidazoles; hydroquinone, resorcinol, bisphenol A and their halides, novolaks. Type phenolic resins, resol type phenolic resins, and other polyfunctional phenols; acid anhydrides such as phthalic anhydride, benzophenone tetracarboxylic dianhydride, methyl hymic acid, etc., and curing accelerators include alkyl Examples include imidazoles such as group-substituted imidazole and benzimidazole.
[0056]
The compounding amount of the curing agent can be determined according to the epoxy equivalent in the polyfunctional epoxy compound. For example, when an amine compound is used as the curing agent, the equivalent of the active hydrogen of the amine and the epoxy equivalent of the polyfunctional epoxy compound. So that they are equal. Moreover, when using polyfunctional phenols or acid anhydrides as a hardening | curing agent, a compounding quantity is such that a phenolic hydroxyl group or a carboxyl group will be 0.6-1.2 equivalent with respect to 1 equivalent of polyfunctional epoxy compounds. It is preferable to make it. When using a hardening accelerator, it is preferable that the compounding quantity of a hardening accelerator is 0.001-10 weight part with respect to 100 weight part of polyfunctional epoxy compounds. When the blending amount of these curing agents or curing accelerators is less than the above range, curing of the polyfunctional epoxy compound becomes insufficient, and the glass transition temperature after curing of the second curable resin tends to decrease, which is large. In some cases, the remaining curing agent or curing accelerator tends to lower the electrical characteristics of the second curable resin after curing.
[0057]
In the second curable resin, a filler, a coupling agent, a flame retardant, and the like can be added as other components as long as the curing is not inhibited.
[0058]
Next, preferred embodiments of the prepreg with an adhesive layer of the present invention will be described with reference to the drawings.
[0059]
FIG. 1 is a cross-sectional view showing an embodiment of a prepreg with an adhesive layer of the present invention. A prepreg 1 with an adhesive layer shown in FIG. 1 includes a prepreg 2 and an adhesive layer 4 made of a second curable resin containing a polyamideimide and an amide-reactive compound formed on the prepreg 2. Here, the first curable resin in the prepreg 2 and the second curable resin constituting the adhesive layer 4 may be the same or different, but are preferably different.
[0060]
In the prepreg 1 with an adhesive layer, the thickness of the prepreg 2 is preferably 20 to 250 μm. Moreover, it is preferable that the thickness of an adhesive bond layer shall be 30 micrometers or less, and it is more preferable to set it as 5-20 micrometers. By setting the thickness of the adhesive layer to 30 μm or less, it is possible to greatly reduce warpage that occurs when the prepreg with an adhesive layer is used for a metal-clad laminate. And it is preferable that the elasticity modulus after hardening of an adhesive bond layer is 500-2500 Mpa, and it is more preferable that it is 800-1500 Mpa. By setting the elastic modulus after curing of the adhesive layer within the above range, the adhesiveness and heat resistance are further improved.
[0061]
Such a prepreg 1 with an adhesive layer can be obtained, for example, as follows. That is, a manufacturing method in which a second curable resin is laminated on a prepreg containing a first curable resin in a B-stage state to form an adhesive layer, and the prepreg and the second curing are performed so that curing is not completed. It can be obtained by laminating the second curable resin on the prepreg while heating the curable resin.
[0062]
The second curable resin is laminated on the prepreg in a heated state using a known heating means (hot air heating, infrared heating, thermocompression bonding, etc.). At the time of such lamination, the prepreg and the second cured resin are laminated. It is preferable to perform heating so that curing of both of the functional resins is not completed. The adhesive layer to be laminated on the prepreg is preferably a film-like curable resin that is formed into a film so that the second curable resin is not completely cured, and is laminated.
[0063]
The method for producing the prepreg with an adhesive layer using the above film-like curable resin can be specifically carried out as follows. That is, first, an adhesive layer made of the second curable resin is formed on a releasable support to obtain a film with an adhesive layer. Next, it laminates | stacks so that the adhesive bond layer of this film with an adhesive layer may contact | connect a prepreg, and it heats and presses to such an extent that a prepreg does not harden | cure completely. And after lamination | stacking, the prepreg with an adhesive bond layer can be obtained by peeling the said support body.
[0064]
Examples of the releasable support include polyethylene terephthalate and aluminum foil, and those having a surface subjected to a release treatment are more preferable. In particular, it is preferable to use a polyethylene terephthalate having a thickness of 30 μm to 200 μm subjected to a release treatment.
[0065]
Examples of the method for forming the adhesive layer on the support include a method in which the second curable resin is applied on the support, and such application is performed by dissolving or dispersing the second curable resin in an organic solvent. It is preferable to carry out in the state of the varnish made. Examples of the organic solvent used in the varnish include dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, sulfolane, and cyclohexanone.
[0066]
As a method of laminating a film with an adhesive layer on a prepreg, for example, a method by roll lamination can be mentioned. That is, the adhesive layer of the film with an adhesive layer is laminated so as to be in contact with the prepreg and laminated by passing between heated rolls while applying pressure. The temperature of the roll in such a method is preferably 150 ° C. or less, and more preferably 80 to 130 ° C. When the temperature of the roll is 150 ° C. or higher, the curing of the second curable resin may proceed excessively, and the support tends to be difficult to peel.
[0067]
Next, a preferred embodiment of the method for producing a metal-clad laminate of the present invention will be described with reference to FIG.
[0068]
FIG. 2A schematically shows a process of laminating two sheets of metal foil 22 that has not been roughened, three prepregs 10 for forming a laminate, and two prepregs 1 with an adhesive layer. FIG. In the same process, three laminated body prepregs 10 are laminated so as to be adjacent to each other, and the metal foil 22 is interposed on the upper and lower surfaces of the laminated laminated prepreg 10 via the prepreg 1 with an adhesive layer. Are stacked. In this case, the adhesive layer 4 in the prepreg 1 with an adhesive layer is disposed so as to be in contact with the metal foil 22.
[0069]
As the metal foil 22, a metal foil such as a copper foil or an aluminum foil can be used, and the thickness is preferably 5 to 200 μm. Also, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. between a copper foil layer having a thickness of 0.5-15 μm and a copper foil layer having a thickness of 10-300 μm A composite foil having a three-layer structure provided with an intermediate layer made of or a composite foil having a two-layer structure in which aluminum and copper foil are combined can also be used. The surface roughness of the metal foil 22 is preferably Rz = 5 μm or less, and more preferably Rz = 2 μm or less. Rz refers to the ten-point average roughness specified in JIS B 0601.
[0070]
After lamination is completed as described above, a metal-clad laminate can be obtained by heating and pressurizing the whole. FIG. 2B is a cross-sectional view schematically showing the obtained metal-clad laminate 30. The metal-clad laminate 30 shown in the figure has a prepreg 1 with an adhesive layer on its upper and lower surfaces, with three layers of a prepreg cured product 20 for laminate formation, which is a cured product of the prepreg 10 for laminate formation, as a central layer. The cured product (consisting of the prepreg cured product 12 and the adhesive layer cured product 14) and the metal foil 22 are laminated in this order.
[0071]
In addition, lamination | stacking and hardening can be performed using a vacuum press etc., It is preferable that the temperature in the case of hardening is 150-280 degreeC, and it is more preferable that it is 180-250 degreeC. Further, the pressure is preferably 0.5 to 20 MPa, more preferably 1 to 8 MPa.
[0072]
In the metal-clad laminate 30, the metal foil 22 is bonded to the prepreg cured product 12 via the adhesive layer cured product 14, and the prepreg cured product 12 and the laminate-forming prepreg cured product 20 are integrated and laminated by curing. The metal foil 22 is firmly bonded to the laminate in the metal-clad laminate 30 even when a fine wiring pattern is formed on the metal-clad laminate 30. The peeling of the conductor layer made of 22 is extremely reduced. Moreover, since the adhesive layer cured product 14 is a cured product of the adhesive layer 4 in the prepreg 1 with the adhesive layer of the present invention, it has high heat resistance, and it is blistered when exposed to high temperatures. Occurrence is greatly reduced.
[0073]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
[0074]
[Synthesis of Polyamideimide]
(Synthesis Example 1)
To a 1 L separable flask equipped with a 25 mL water meter with a cock connected to a reflux condenser, a thermometer, and a stirrer, 2,2-bis [4- (4-aminophenoxy) phenyl] as an aromatic diamine Propane (BAPP) 43.1 g (0.105 mol), reactive silicon oil KF8010 (manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 445) as siloxane diamine, 40.1 g (0.045 mol), trimellitic anhydride (TMA) 60.5 g (0.315 mol), 440 g of N-methyl-2-pyrrolidone (NMP) was added as an aprotic polar solvent, and the mixture was stirred at 80 ° C. for 30 minutes.
[0075]
After completion of stirring, 100 mL of toluene was added as an aromatic hydrocarbon azeotropic with water, and the temperature was raised to 160 ° C. and refluxed for 2 hours. After confirming that 5.4 mL or more of water had accumulated in the moisture determination receiver and that no water distilling was observed, the temperature was increased to 190 ° C. while removing the water in the moisture determination receiver, Was removed.
[0076]
After returning the solution in the flask to room temperature, 45.1 g (0.18 mol) of 4,4′-diphenylmethanediisocyanate (MDI) was added as an aromatic isocyanate, the temperature was raised to 190 ° C., and the reaction was performed for 2 hours. An NMP solution of polyamideimide having a base amount of 8.1% by weight and a silicon amount of 6.9% by weight was obtained.
[0077]
(Synthesis Example 2)
In a 1 L separable flask equipped with a 25 mL water meter with a cock connected to a reflux condenser, a thermometer, and a stirrer, 41.1 g (0.10 mol) of BAPP as an aromatic diamine and reactive silicone oil as a siloxane diamine 90.0 g (0.10 mol) of KF8010, 80.7 g (0.42 mol) of TMA and 505 g of NMP as an aprotic polar solvent were added and stirred at 80 ° C. for 30 minutes.
[0078]
After completion of stirring, 100 mL of toluene was added as an aromatic hydrocarbon azeotropic with water, and the temperature was raised to 160 ° C. and refluxed for 2 hours. After confirming that about 7.2 mL or more of water had accumulated in the moisture determination receiver and that water was no longer distilled, the temperature was increased to 190 ° C. while removing the water in the moisture determination receiver, Was removed.
[0079]
After returning the solution in the flask to room temperature, 60.1 g (0.24 mol) of MDI was added as an aromatic isocyanate, the temperature was raised to 190 ° C. and reacted for 2 hours, the amount of amide groups was 7.4% by weight, the amount of silicon was 10 An NMP solution of 9% by weight of polyamideimide was obtained.
[0080]
(Synthesis Example 3)
In a 1 L separable flask equipped with a 25 mL water meter with a cock connected to a reflux condenser, a thermometer, and a stirrer, 55.4 g (0.135 mol) of BAPP as an aromatic diamine and reactive silicone oil as a siloxane diamine 46.8 g (0.015 mol) of X-22-161B (manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 1560), 60.5 g (0.315 mol) of TMA, and 485 g of NMP as an aprotic polar solvent were added and stirred at 80 ° C. for 30 minutes. did.
[0081]
After completion of stirring, 100 mL of toluene was added as an aromatic hydrocarbon azeotropic with water, and the temperature was raised to 160 ° C. and refluxed for 2 hours. After confirming that 5.4 mL or more of water had accumulated in the moisture determination receiver and that no water distilling was observed, the temperature was increased to 190 ° C. while removing the water in the moisture determination receiver, Was removed.
[0082]
After returning the solution in the flask to room temperature, 45.1 g (0.18 mol) of MDI was added as an aromatic isocyanate, the temperature was raised to 190 ° C., and the mixture was reacted for 2 hours. The amount of amide groups was 7.2% by weight, the amount of silicon was 9 An NMP solution of 0.0% by weight of polyamideimide was obtained.
[0083]
(Comparative Synthesis Example 1)
In a 2 L separable flask equipped with a 25 mL water meter with a cock connected to a reflux condenser, a thermometer, and a stirrer, 24.6 g (0.06 mol) of BAPP as an aromatic diamine and reactive silicone oil as a siloxane diamine X-22-161A (manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 805) 225.4 g (0.14 mol), TMA 80.7 g (0.42 mol), NMP 725 g as an aprotic polar solvent was added and stirred at 80 ° C. for 30 minutes. did.
[0084]
After completion of the stirring, 150 mL of toluene was added as an aromatic hydrocarbon azeotropic with water, and the temperature was raised to 160 ° C. and refluxed for 2 hours. After confirming that about 7.2 mL or more of water had accumulated in the moisture determination receiver and that water was no longer distilled, the temperature was increased to 190 ° C. while removing the water in the moisture determination receiver, Was removed.
[0085]
After returning the solution in the flask to room temperature, 60.1 g (0.24 mol) of MDI was added as an aromatic isocyanate, the temperature was raised to 190 ° C., and the mixture was reacted for 2 hours. The amount of amide groups was 4.9% by weight, the amount of silicon was 21 An NMP solution of 7 wt% polyamideimide was obtained.
[0086]
[Preparation of second curable resin]
(Preparation Example 1)
300 g of NMP solution of polyamideimide obtained in Synthesis Example 1 (solid content 30% by weight), 20 g of ZX-15548-2 (manufactured by Tohto Kasei Co., Ltd., phosphorus-containing polyfunctional epoxy resin) as an amide-reactive compound Dimethylacetamide solution having a resin solid content of 50% by weight) and 0.2 g of 2-ethyl-4-methylimidazole were mixed, stirred for about 1 hour until the composition became homogeneous, and then allowed to stand at room temperature for 24 hours for defoaming. Then, a varnish of a second curable resin having a total amide group amount of 7.3% by weight and a total silicon amount of 6.3% by weight was obtained.
[0087]
(Preparation Example 2)
267 g of NMP solution of polyamideimide obtained in Synthesis Example 1 (solid content 30% by weight), 40 g of ZX-1548-2 which is an epoxy resin as an amide-reactive compound (dimethylacetamide solution having a resin solid content of 50% by weight), After adding 0.2 g of 2-ethyl-4-methylimidazole and stirring for about 1 hour until the composition became uniform, the mixture was allowed to stand at room temperature for 24 hours for defoaming, and the total amount of amide groups was 6.4 wt. %, A second curable resin varnish having a total silicon content of 5.6% by weight was obtained.
[0088]
(Preparation Example 3)
300 g of NMP solution of polyamideimide obtained in Synthesis Example 1 (solid content 30% by weight), 20 g of DER-331L (bisphenol A type epoxy resin manufactured by Dow Chemical Co.) which is an epoxy resin as an amide reactive compound (resin solid content) 50% by weight dimethylacetamide solution) and 0.2 g of 2-ethyl-4-methylimidazole were stirred and stirred for about 1 hour until the composition became homogeneous, and then allowed to stand at room temperature for 24 hours for defoaming. A second curable resin varnish having a total amide group content of 7.3% by weight and a total silicon content of 6.3% by weight was obtained.
[0089]
(Preparation Example 4)
300 g of NMP solution of polyamideimide obtained in Synthesis Example 1 (solid content 30% by weight), 20 g of YDCN-195 (cresol novolak type epoxy resin manufactured by Toto Kasei Co., Ltd.) which is an epoxy resin as an amide reactive compound (resin solid content) 50% by weight dimethylacetamide solution) and 0.2 g of 2-ethyl-4-methylimidazole were stirred and stirred for about 1 hour until the composition became homogeneous, and then allowed to stand at room temperature for 24 hours for defoaming. A second curable resin varnish having a total amide group content of 7.3% by weight and a total silicon content of 6.3% by weight was obtained.
[0090]
(Preparation Example 5)
300 g of NMP solution of polyamideimide obtained in Synthesis Example 2 (solid content 35% by weight), 20 g of ZX-1548-2 which is an epoxy resin as an amide reactive compound (dimethylacetamide solution of resin solid content 50% by weight), After blending 0.3 g of 2-ethyl-4-methylimidazole and stirring for about 1 hour until the composition became homogeneous, the mixture was allowed to stand at room temperature for 24 hours for defoaming, and the total amount of amide groups was 6.5 wt. %, A second curable resin varnish having a total silicon content of 9.8% by weight was obtained.
[0091]
(Preparation Example 6)
300 g of NMP solution of polyamideimide obtained in Synthesis Example 3 (solid content 30 wt%), 20 g of ZX-1548-2 which is an epoxy resin as an amide reactive compound (dimethylacetamide solution of resin solid content 50 wt%), After mixing 0.3 g of 2-ethyl-4-methylimidazole and stirring for about 1 hour until the composition became uniform, the mixture was allowed to stand at room temperature for 24 hours for defoaming, and the total amount of amide groups was 4.4 wt. %, A second curable resin varnish having a total silicon content of 8.1% by weight was obtained.
[0092]
(Comparative Preparation Example 1)
300 g of NMP solution of polyamideimide obtained in Comparative Synthesis Example 1 (resin solid content 30 wt%), 20 g of ZX-1548-2 which is an epoxy resin as an amide reactive compound (dimethylacetamide solution of resin solid content 50 wt%) ), 2-ethyl-4-methylimidazole (0.3 g) was added, and the mixture was stirred for about 1 hour until the composition became homogeneous, and then allowed to stand at room temperature for 24 hours for defoaming. A varnish of a second curable resin having 2% by weight and a total silicon amount of 19.5% by weight was obtained.
[0093]
(Comparative Preparation Example 2)
133 g of NMP solution of polyamideimide obtained in Synthesis Example 1 (resin solid content 30 wt%), 120 g of ZX-1548-2 which is an epoxy resin as an amide reactive compound (dimethylacetamide solution of 50 wt% resin solid content) After mixing with 1.2 g of 2-ethyl-4-methylimidazole and stirring for about 1 hour until the composition became homogeneous, the mixture was allowed to stand at room temperature for 24 hours for defoaming. A second curable resin varnish having a weight percent of 2.8% by weight of total silicon was obtained.
[0094]
[Preparation of prepreg with adhesive layer]
(Example 1)
The varnish of the second curable resin obtained in Preparation Example 1 is formed into a 50 μm-thick polyethylene terephthalate film (PET film, Purex, manufactured by Teijin Limited), and the thickness after drying of the adhesive layer is 15 μm. The film with an adhesive layer containing 5 to 7% by weight of a volatile component was obtained by heating and drying at 130 ° C. for 20 minutes.
[0095]
Next, the obtained film with an adhesive layer was layered on a prepreg (GEA-I-671, manufactured by Hitachi Chemical Co., Ltd.) so that the adhesive layer was in contact, and the temperature was 120 ° C. and the speed was 0.2 m / min. After laminating with a hot roll laminator under the above conditions, the PET film was peeled off to obtain a prepreg with an adhesive layer of Example 1 in which an adhesive layer was formed on the prepreg.
[0096]
(Examples 2-6, Comparative Examples 1-2)
Similar to Example 1, except that the varnish of the second curable resin of Preparation Examples 2 to 6 and Comparative Adjustment Examples 1 and 2 was used instead of the varnish of the second curable resin obtained in Preparation Example 1. Thus, prepregs with adhesive layers of Examples 2 to 6 and Comparative Examples 1 and 2 were obtained. In addition, the case where the varnish of the 2nd curable resin of preparation examples 2-6 was used for Examples 2-6, and the case where the varnish of the 2nd curable resin of comparative adjustment examples 1-2 was used is a comparative example. It corresponds to 1-2 respectively.
[0097]
(Examples 7 to 11)
Similar to Example 1 except that the varnish of the second curable resin obtained in Preparation Example 1 was applied so that the thickness of the adhesive layer after drying was 5, 10, 20, 30, 50 μm. Thus, prepregs of Examples 7 to 11 were obtained. In addition, what made thickness after drying of an adhesive bond layer 5, 10, 20, 30, 50 micrometers corresponded to Examples 7, 8, 9, 10, and 11, respectively.
[0098]
[Measurement of adhesive strength, solder heat resistance and elastic modulus]
After laminating the prepregs with adhesive layers of Examples 1 to 6 and Comparative Examples 1 and 2 so that the prepregs were in contact with both surfaces of the laminate obtained by laminating three prepregs (GEA-I-671), The glossy surfaces (Rz = 2.0μm) or GTS-12 (manufactured by Furukawa Circuit Foil, Rz = 8.0 μm) is laminated, and a metal-clad lamination is performed by using a vacuum press at 230 ° C. for 90 minutes and 4.0 MPa. I got a plate.
[0099]
The adhesive strength was measured by measuring the peel strength (90 ° peel strength, in accordance with JIS C6481) when peeling the copper foil in each obtained metal-clad laminate in the direction of 90 degrees. It was.
[0100]
Next, the metal-clad laminate obtained by using the copper foil of Rz = 1.8 μm as described above was cut into 20 mm × 20 mm as samples for solder heat resistance test, and these samples were used at 260 ° C. and 288 ° C. Each was immersed in a solder bath and visually checked for blistering or peeling of the metal foil to evaluate solder heat resistance. In addition, evaluation of solder heat resistance measured the time after the sample was immersed in a solder bath until blistering or peeling of metal foil was seen, and the obtained time was made into the measured value.
[0101]
Moreover, in order to compare with the case where the prepreg which does not have an adhesive bond layer is used, as reference example 1, it is Rz = 1.2 on both surfaces of the laminated body which laminated | stacked five prepregs (GEA-I-671). Using a metal-clad laminate obtained by laminating 8 μm copper foil and pressing it at 230 ° C. for 90 minutes and 4.0 MPa using a vacuum press, the adhesive strength and solder heat resistance were the same as above. Measurements were made.
[0102]
Furthermore, in order to measure the elastic modulus after curing of the adhesive layer, the following test was performed. First, the varnish of the second curable resin obtained in Preparation Examples 1 to 6 and Comparative Preparation Examples 1 and 2 is dried on a polyethylene terephthalate film (PET film) having a thickness of 50 μm so that the thickness after drying becomes 80 μm. Each was applied and heated at 130 ° C. for 30 minutes to volatilize and cure the solvent. After curing, the PET film is peeled off to obtain a cured product of the second curable resin, the obtained cured product of the second curable resin is sandwiched between SUS frames, and further heated at 230 ° C. for 90 minutes. And a film-like curable resin having a thickness of 80 μm was obtained. And the elasticity modulus in 30 degreeC of the obtained film-form curable resin was measured using the dynamic viscoelasticity measuring apparatus (made by Rheology).
[0103]
The results obtained by the measurement of the adhesive strength and solder heat resistance are shown together in Table 1. Moreover, the measurement result of the elastic modulus was described in the column of the prepreg using the same varnish of the second curable resin.
[Table 1]

[0104]
As shown in Table 1, in the metal-clad laminate using the prepreg with adhesive layers of Examples 1 to 6, the copper foil having any surface roughness is 0.8 to 1.4 kN / m. Adhesive strength was exhibited, and even when immersed in a solder bath at any temperature, no abnormality such as blistering or peeling of the metal foil was observed for 3 minutes or more, whereas the adhesives of Comparative Examples 1 and 2 In the metal-clad laminate using the prepreg with a layer and Reference Example 1, the adhesive strength of 0.2 to 0.6 kN / m is exhibited, and both are blistered or metal foil within 30 seconds after being immersed in the solder bath The peeling of was seen.
[0105]
[Evaluation of the effect of adhesive layer thickness]
After the prepreg with adhesive layer of Examples 7 to 11 was laminated on one side of a laminate in which three prepregs were laminated so that the adhesive layer was in contact, F0-WS was used as a copper foil on the adhesive layer. -12 (Rz = 1.8 μm) or SLP-12 glossy surface (Rz = 2.0 μm) is laminated and pressed using a vacuum press at 230 ° C. for 90 minutes and 4.0 MPa. A tension laminate was obtained.
[0106]
Using each of the obtained metal-clad laminates, the occurrence of warpage was confirmed and the adhesive strength was measured. The occurrence of warpage was confirmed by visual observation of whether or not warpage occurred in the metal-clad laminate, and the adhesion strength was measured in the same manner as described above.
[0107]
Table 2 summarizes the results of confirmation of the occurrence of warpage and measurement of adhesive strength. In Table 2, those in which no warpage was observed were indicated by ◯, and those in which warpage was observed were indicated by ×.
[Table 2]

[0108]
As shown in Table 2, any metal-clad laminate using a prepreg with an adhesive layer showed an adhesive strength of 0.6 to 1.1 kN / m, but the thickness of the adhesive layer is 50 μm. In the metal-clad laminate using the prepreg with an adhesive layer, warpage occurred on the surface so that the copper foil was inside.
[0109]
[Evaluation of circuit formability]
After laminating the prepregs with adhesive layers of Examples 1 and 6 and Comparative Example 1 on both sides of a laminate in which four prepregs were laminated so that the prepregs were in contact, SLP-100 was applied to one adhesive layer. (Manufactured by Nippon Electrolytic Co., Ltd.), and copper foils (Rz = 1.8 μm, Rz = 2.0 μm or Rz = 8.0 μm) with different surface roughness are laminated on the other adhesive layer, respectively, and vacuum press A metal-clad laminate was obtained by performing pressing at 230 ° C. for 90 minutes and 4.0 MPa.
[0110]
Each of the obtained metal-clad laminates is used to form a full resist on the surface of SLP-100 existing on one side of the metal-clad laminate, and on the copper foils having different surface roughnesses on the other side. In addition, comb resist patterns having a line width / space width (L / S) of 20 μm / 20 μm, 30 μm / 30 μm, 40 μm / 40 μm, or 50 μm / 50 μm were formed, respectively. And after removing unprotected copper foil by etching using a ferric chloride solution, the resist was peeled off to form a wiring pattern.
[0111]
The evaluation of the circuit formability of the metal-clad laminate on which the wiring pattern was formed was performed using a microscope, and this evaluation was performed using the minimum value of the line width / space width (L / S) at which circuit formation was possible. The sex value.
[0112]
Moreover, in order to compare with the case where the prepreg which does not have an adhesive bond layer is used, on both surfaces of the laminated body which laminated | stacked five prepregs (GEA-I-671) as the reference example 2, it is similar to the above. Using a metal-clad laminate obtained by laminating copper foils, circuit formability was evaluated in the same manner as described above.
[0113]
Table 3 summarizes the evaluation results of the obtained circuit formability.
[Table 3]

[0114]
As shown in Table 3, in the metal-clad laminate using the prepreg with an adhesive layer of Example 1 or 6, a copper foil having a relatively smooth metal foil surface (Rz = 1.8 μm or 2.0 μm) is used. Even with the metal-clad laminate used, residual copper during etching can be removed in a short time, and a good wiring pattern with a cross-sectional shape close to a rectangle can be obtained with line width / space width = 20 μm / 20 μm. It was. On the other hand, in the metal-clad laminate using the prepreg with an adhesive layer of Comparative Example 1 or Reference Example 2, when the copper foil of Rz = 1.8 μm or 2.0 μm was used, the copper foil was partially peeled off. . When a copper foil of Rz = 8.0 μm was used, peeling did not occur in any of the metal-clad laminates, but it took a long time to remove the remaining copper on the copper foil surface during etching. There was a tendency for the top of the to become a thin bowl. For this reason, the line width / space width is 40 μm / 40 μm, which is the limit for obtaining a good wiring pattern.
[0115]
【The invention's effect】
As described above, according to the prepreg with an adhesive layer of the present invention, even when a metal foil that has not been roughened is used, the adhesion between the metal foil and the laminate is excellent and fine. Even when the wiring pattern is formed, it is possible to obtain a metal-clad laminate that does not peel off the conductor layer and is excellent in heat resistance. Moreover, according to this invention, it becomes possible to provide the manufacturing method of the metal-clad laminated board using the prepreg with an adhesive layer of this invention, and the metal-clad laminated board obtained by this method.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a prepreg with an adhesive layer of the present invention.
FIG. 2 (a) shows a step of laminating two sheets of metal foil 22 that has not been roughened, three laminate-forming prepregs 10, and two prepregs 1 with an adhesive layer. It is sectional drawing shown typically, (b) is sectional drawing which shows the obtained metal-clad laminated board 40 typically.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Prepreg with an adhesive layer, 2 ... Prepreg, 4 ... Adhesive layer, 10 ... Laminated prepreg, 12 ... Prepreg cured product, 14 ... Adhesive layer hardening , 20 ... prepreg cured product for forming a laminate, 22 ... metal foil, 30 ... metal-clad laminate.

Claims (5)

A prepreg with an adhesive layer comprising a prepreg made of a first curable resin in a B-stage state and an adhesive layer made of a second curable resin formed on the prepreg,
The second curable resin includes a polyamideimide having a siloxane structure in the main chain and an amide reactive compound having a functional group that causes a reaction with the amide group of the polyamideimide,
The polyamideimide is a diimide dicarboxylic acid obtained by reacting an aromatic diamine represented by the following general formula (1) and a diamine mixture containing a siloxane diamine represented by the following general formula (2) with trimellitic anhydride. A polyamideimide obtained by reacting an aromatic diisocyanate with an acid;

[Wherein, X is a divalent group represented by the following general formula (3a) or (3b), R ¹ is an alkyl group, a phenyl group or a substituted phenyl group, and R ² is an alkylene group, a phenylene group or a substituted phenylene group. , N represents an integer of 1-15.

Y is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a halogenated aliphatic hydrocarbon group having 1 to 3 carbon atoms, a sulfonyl group, an ether group, a carbonyl group, or a single bond, and a plurality of R ^1. And R ² may be the same or different. ]
The amide reactive compound is a polyfunctional epoxy compound having two or more epoxy groups,
The weight part X of the amide-reactive compound with respect to 100 parts by weight of the polyamideimide is:
The amount of amide groups in the polyamide-imide is A wt%, the amount of amide groups in the amide-reactive compound is B wt%, the amount of silicon in the polyamide-imide is C wt%, and the amount of silicon in the amide-reactive compound is When D weight%,
The following formulas (I) and (II),
4 ≦ (A × 100 + B × X) / (100 + X) ≦ 10 (I)
1 ≦ (C × 100 + D × X) / (100 + X) ≦ 15 (II)
The filling,
A prepreg with an adhesive layer, wherein an elastic modulus at 30 ° C. after curing of the adhesive layer is 1900 to 2500 MPa.   The prepreg with an adhesive layer according to claim 1, wherein the prepreg is a prepreg in which reinforcing fibers are arranged.   The thickness of the said adhesive bond layer is 30 micrometers or less, The prepreg with an adhesive bond layer of Claim 1 or 2 characterized by the above-mentioned. In the method for producing a metal-clad laminate in which at least one metal foil and a prepreg are used so that the prepreg is laminated on at least one surface of the metal foil, and heated and pressed.
At least one of the metal foils is a metal foil that has not been roughened,
The prepreg with an adhesive layer according to any one of claims 1 to 3 , wherein the prepreg that is heated and pressed adjacent to at least the metal foil is disposed so that the adhesive layer is in contact with the metal foil. A method for producing a metal-clad laminate characterized by the above. A metal-clad laminate obtained by the method for producing a metal-clad laminate according to claim 4 .

Images