JP2004051910A - Resin film and metal-clad laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermosetting film having high adhesive strength to a flat metal foil, and a laminated sheet in which a prepreg, etc., the film and the flat metal foil are laminated in order. <P>SOLUTION: This resin film comprises a half-cured resin composition in which an amount of an amide group is 4-10 wt.% and a resin skeleton has 1-15 wt.% silicon. The resin film has a thickness of ≤30μm or an elastic modulus of 500-2,500 MPa. The metal-clad laminated sheet is made by heat curing of the resin film held between a thermosetting resin sheet and the metal foil. <P>COPYRIGHT: (C)2004,JPO

Description

一般式（１式）中Ｒ_１０、Ｒ_１１は２価の有機基を示し、Ｒ_１２〜Ｒ_１５はアルキル基、フェニル基または置換フェニル基を示し、ｎは１〜１５の整数を示す。
【００１３】
これらの中でもジメチルシロキサン系両末端アミンである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、信越化学工業株式会社製商品名）、ＢＹ１６−８５３（アミン当量６５０）、ＢＹ１６−８５３Ｂ（アミン当量２２００）（以上、東レダウコーニングシリコーン株式会社製商品名）などが市販品として挙げられ使用することができる。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。
【００１４】
（ｄ）本発明で用いる芳香族ジイソシアネートとして、４，４´−ジフェニルメタンジイソシアネート（以下、ＭＤＩと略す。）、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。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。
本発明では、ジイミドジカルボン酸と芳香族ジイソシアネートとをモル比１．０／１．０〜１．０／１．５で反応させることが好ましく、芳香族ジイソシアネートのモル比が１．０未満であると、シロキサン変性ポリアミドイミド樹脂の可撓性が低下してくるため好ましくなく、芳香族ジイソシアネートのモル比が１．５を超えても同様となるので好ましくない。
【００１５】
このようなシロキサン変性ポリアミドイミド樹脂の製造方法の一例を次に示す。芳香族環を３個以上有するジアミン、シロキサンジアミンおよび無水トリメリット酸（ＴＭＡ）を、Ｎ−メチル−２−ピロリドン等の非プロトン性極性溶媒の存在下に、５０〜９０℃で反応させる。その後、トルエン等の水と共沸可能な芳香族炭化水素を非プロトン性極性溶媒の０．１〜０．５質量比で投入し、１２０〜１８０℃で反応を行ってジイミドジカルボン酸を含む溶液を得る。好ましくは、ここで約１９０℃まで温度を上げて前記芳香族炭化水素を溶液から除去する。次いで、溶液を室温に戻し、芳香族ジイソシアネートを投入し、１９０℃程度で約２時間反応させてシロキサン構造を有するポリアミドイミド樹脂の極性溶媒溶液を得ることができる。
【００１６】
次に、本発明で用いる熱硬化性樹脂について説明する。
本発明では、ポリアミドイミド樹脂中のアミド基と反応し得る有機基を有する熱硬化性樹脂が好ましい。熱硬化性樹脂として、エポキシ樹脂、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挙げられ、グリシジル基を有するエポキシ樹脂がより好ましい。ポリアミドイミド樹脂１００重量部に対し熱硬化性樹脂１〜２００重量部用いるのが好ましい。
本発明では、最終的に樹脂組成物中のアミド基量が４〜１０重量％でかつ樹脂骨格中にケイ素を１〜１５重量％含むように、ポリアミドイミド樹脂及び熱硬化性樹脂を配合する。
例えば、使用するポリアミドイミド樹脂のアミド基量ＰＡ重量％、樹脂骨格中ケイ素量ＰＢ重量％、熱硬化性樹脂のアミド基量ＥＡ重量％、樹脂骨格中ケイ素量ＥＢ重量％、の場合、ポリアミドイミド樹脂１００重量部に対して熱硬化性樹脂Ｃ重量部は、以下の関係を満たす範囲から選択される。
４≦（ＰＡ×１００＋ＥＡ×Ｃ）／（１００＋Ｃ）≦１０
１≦（ＰＢ×１００＋ＥＢ×Ｃ）／（１００＋Ｃ）≦１５
【００１７】
本発明では、熱硬化性樹脂としてエポキシ樹脂を用いることが１８０℃以下の温度で硬化が可能で、ポリアミドイミド樹脂のアミド基に対して反応して熱的、機械的、電気的特性を向上させるため好ましく、さらに、２個以上のグリシジル基を持つエポキシ樹脂とその硬化剤、２個以上のグリシジル基を持つエポキシ樹脂とその硬化促進剤または２個以上のグリシジル基を持つエポキシ樹脂と硬化剤と硬化促進剤を用いることが好ましい。またグリシジル基は多いほどよく、３個以上であればさらに好ましい。グリシジル基の数により、配合量が異なり、グリシジル基が多いほど配合量が少なくてもよい。
【００１８】
エポキシ樹脂としては、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又は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を反応させて得られるポリグリシジルエーテル、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を反応させて得られ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などが挙げられる。
【００１９】
樹脂組成物中に配合されるエポキシ樹脂の硬化剤、硬化促進剤は、エポキシ樹脂と反応するもの、または、硬化を促進させるものであれば制限なく、例えば、アミン類、イミダゾール類、多官能フェノール類、酸無水物類等が使用できる。
アミン類として、ジシアンジアミド、ジアミノジフェニルメタン、グアニル尿素等が使用でき、多官能フェノール類としては、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合物、さらにホルムアルデヒドとの縮合物である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などが使用でき、酸無水物類としては、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が使用できる。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使用できる。
【００２０】
これらの硬化剤または硬化促進剤の必要な量は、アミン類の場合は、アミンの活性水素の当量と、エポキシ樹脂のエポキシ当量がほぼ等しくなる量が好ましい。硬化促進剤であるイミダゾールの場合は、単純に活性水素との当量比とならず、経験的にエポキシ樹脂１００重量部に対して、０．００１〜１０重量部となる。多官能フェノール類や酸無水物類の場合、エポキシ樹脂１当量に対して、フェノール性水酸基やカルボキシル基０．６〜１．２当量である。これらの硬化剤または硬化促進剤の量は、少なければ未硬化のエポキシ樹脂が残り、Ｔｇ（ガラス転移温度）が低くなり、多すぎると、未反応の硬化剤及び硬化促進剤が残り、絶縁性が低下する。エポキシ樹脂のエポキシ当量は、シロキサン変性ポリアミドイミド樹脂のアミド基とも反応することができるので考慮に入れることが好ましい。
【００２１】
さらに、本発明の効果を損なわない範囲で、樹脂組成物に通常添加される充填剤、カップリング剤、難燃剤等を、本発明における樹脂組成物に適宜配合することができる。
【００２２】
本発明の第一の樹脂フィルム及び本発明の第二の樹脂フィルム（以下、本発明の樹脂フィルムという。）は、アミド基量が４〜１０重量％でかつ樹脂骨格中にケイ素を１〜１５重量％含む上記の樹脂組成物が半硬化してなる。特に、本発明の第一の樹脂フィルムは、乾燥後の厚みが３０μｍ以下である。乾燥後の厚み３０μｍ以下であれば応力の発生が少なく、そりが低減できる。
また、本発明の第二の樹脂フィルムは、３０℃での弾性率が５００〜２５００ＭＰａである。５００ＭＰａ以上であると接着性が、また、２５００ＭＰａ以下であると熱応力が、それぞれ良好となる。
【００２３】
本発明の樹脂フィルムは、基材の片面に前記樹脂組成物の層を形成し、半硬化（Ｂステージ）状態に乾燥させて作製するのが、特に保存性及び作業性の点で、好ましい。ここで、樹脂組成物を有機溶媒中で混合、溶解、分散して得られるワニスの形態で基材に塗布して層を形成するのがさらに好ましい。このような有機溶媒としては、溶解性が得られるものであれば制限するものでなく、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。
樹脂組成物を塗布して樹脂組成物の層を形成する基材としては、樹脂フィルムを次の段階で金属箔等と積層する際に、樹脂フィルムが剥がせるものであれば特に制限されないが、通常シート形状の、ポリエチレンテレフタレートやアルミ箔及びこれらの基材表面に離型処理を施した基材等が用いられる。厚さ３０μｍ〜２００μｍの離型処理を施したポリエチレンテレフタレートフィルムが特に好適に用いられる。
【００２４】
樹脂フィルムの製造条件等は特に制限するものではないが、ワニスに使用した溶剤が８０重量％以上揮発していることが好ましい。このため、製造方法や乾燥条件等も制限はなく、乾燥時の温度は８０℃〜１８０℃が一般的で、乾燥時間はワニスのゲル化時間との兼ね合いで特に制限はない。
【００２５】
本発明の樹脂フィルムを得るための樹脂組成物に、シロキサン変性ポリアミドイミド樹脂と熱硬化性樹脂とを含む上記樹脂組成物を使用した場合、ワニス溶剤の揮発速度が速く、熱硬化性樹脂の硬化反応を促進しない１５０℃以下の低温でも残存溶剤分を５重量％以下にすることが可能な樹脂フィルムが得られる。これは、例えば、平滑な金属とプリプレグ、接着シート、接着剤付きポリイミドシート、接着性ポリイミドシート等との間に耐熱性接着シートとして用いると良好な密着性が得られる。これは耐熱性の高いポリアミドイミド樹脂をシロキサン変性しているためであり、残存溶剤分を少なくすることができるため銅箔との積層工程において溶剤揮発によるフクレの発生を防止したり、はんだ耐熱性に優れたものとすることができる。
【００２６】
本発明の金属張積層板は、熱硬化性樹脂シートと金属箔との間に上記本発明の樹脂フィルムを挟んで加熱硬化したものである。
金属張積層板の製造方法は次の通りである。金属箔と、本発明の樹脂フィルムと、熱硬化性樹脂シート又はそれを複数枚積層した積層体とを重ね、通常１５０〜２８０℃、好ましくは１８０℃〜２５０℃の範囲の温度で、通常０．５〜２０ＭＰａ、好ましくは１〜８ＭＰａの範囲の圧力で、加熱加圧成形することにより金属張積層体を製造することができる。金属箔を使用して金属張積層板とすることにより、これに回路加工を施してプリント回路板とすることができる。
【００２７】
熱硬化性樹脂シートとして、プリプレグ、接着シート、接着剤付きポリイミドシート及び接着性ポリイミドシート等が使用でき、いずれの場合も上記の熱硬化性樹脂シートの場合に準じて、本発明の樹脂フィルムを挟み加熱加圧して金属箔積層体を製造することができる。
【００２８】
本発明に用いられる金属箔は、銅箔やアルミニウム箔が一般的に用いられるが、通常積層板に用いられている５〜２００μｍのものを使用できる。また、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−スズ合金等を中間層とし、この両面に０．５〜１５μｍの銅層と１０〜３００μｍの銅層を設けた３層構造の複合箔あるいはアルミニウムと銅箔を複合した２層構造複合箔を用いることができる。金属箔の表面粗さはＲｚで５．５以下のものを使用することが本発明の接着性に起因する微細回路形成性、高周波特性を得る上で好ましく、Ｒｚが２．０以下であるとさらに好ましい。
【００２９】
【実施例】
以下に実施例を挙げて説明するが、本発明はこれらに限定されるものではない。
（合成例１）
環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、撹拌器を備えた１リットルのセパラブルフラスコに
芳香族環を３個以上有するジアミンとして２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン（以下、ＢＡＰＰという。）４３．１ｇ（０．１０５ｍｏｌ）、
シロキサンジアミンとして反応性シリコーンオイル　ＫＦ８０１０（信越化学工業株式会社製商品名、アミン当量４４５）４０．１ｇ（０．０４５ｍｏｌ）、
ＴＭＡ（無水トリメリット酸）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（以下、ＮＭＰという。）４４０ｇ
を仕込み、８０℃で３０分間撹拌した。
そして水と共沸可能な芳香族炭化水素としてトルエン１００ｍｌを投入してから温度を上げ約１６０℃で２時間環流させた。水分定量受器に水が約５．４ｍｌ以上たまっていること、水の留出が見られなくなっていることを確認し、水分定量受器にたまっている留出液を除去しながら、約１９０℃まで温度を上げて、トルエンを除去した。その後、溶液を室温に戻し、芳香族ジイソシアネートとして４，４´−ジフェニルメタンジイソシアネート（以下、ＭＤＩという。）４５．１ｇ（０．１８ｍｏｌ）を投入し、１９０℃で２時間反応させた。反応終了後、アミド基量８．１重量％、ケイ素量６．９重量％のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液を得た。
【００３０】
（合成例２）
環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、撹拌器を備えた１リットルのセパラブルフラスコに芳香族環を３個以上有するジアミンとしてＢＡＰＰ　４１．１ｇ（０．１ｍｏｌ）、シロキサンジアミンとして反応性シリコーンオイル　ＫＦ８０１０（信越化学工業株式会社製商品名、アミン当量４５０）９０．０ｇ（０．１０ｍｏｌ）、ＴＭＡ（無水トリメリット酸）８０．７ｇ（０．４２ｍｏｌ）を、非プロトン性極性溶媒としてＮＭＰ　５０５ｇを仕込み、８０℃で３０分間撹拌した。そして水と共沸可能な芳香族炭化水素としてトルエン１００ｍｌを投入してから温度を上げ約１６０℃で２時間環流させた。水分定量受器に水が約７．２ｍｌ以上たまっていること、水の留出が見られなくなっていることを確認し、水分定量受器にたまっている留出液を除去しながら、約１９０℃まで温度を上げて、トルエンを除去した。その後、溶液を室温に戻し、芳香族ジイソシアネートとしてＭＤＩ　６０．１ｇ（０．２４ｍｏｌ）を投入し、１９０℃で２時間反応させた。反応終了後、アミド基量７．４重量％、ケイ素量１０．９重量％のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液を得た。
【００３１】
（合成例３）
環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、撹拌器を備えた１リットルのセパラブルフラスコに芳香族環を３個以上有するジアミンとしてＢＡＰＰ　５５．４ｇ（０．１３５ｍｏｌ）、シロキサンジアミンとして反応性シリコーンオイル　Ｘ−２２−１６１Ｂ（信越化学工業株式会社製商品名、アミン当量１５６０）４６．８ｇ（０．０１５ｍｏｌ）、ＴＭＡ（無水トリメリット酸）６０．５ｇ（０．３１５ｍｏｌ）を、非プロトン性極性溶媒としてＮＭＰ　４８５ｇを仕込み、８０℃で３０分間撹拌した。そして水と共沸可能な芳香族炭化水素としてトルエン１００ｍｌを投入してから温度を上げ約１６０℃で２時間環流させた。水分定量受器に水が約５．４ｍｌ以上たまっていること、水の留出が見られなくなっていることを確認し、水分定量受器にたまっている留出液を除去しながら、約１９０℃まで温度を上げて、トルエンを除去した。その後、溶液を室温に戻し、芳香族ジイソシアネートとしてＭＤＩ　４５．１ｇ（０．１８ｍｏｌ）を投入し、１９０℃で２時間反応させた。反応終了後、アミド基量７．２重量％、ケイ素量９．０重量％のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液を得た。
【００３２】
（比較合成例１）
環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、撹拌器を備えた２リットルのセパラブルフラスコに芳香族環を３個以上有するジアミンとしてＢＡＰＰ　２４．６ｇ（０．０６ｍｏｌ）、シロキサンジアミンとして反応性シリコーンオイル　Ｘ−２２−１６１Ａ（信越化学工業株式会社製商品名、アミン当量８０５）２２５．４ｇ（０．１４ｍｏｌ）、ＴＭＡ（無水トリメリット酸）８０．７ｇ（０．４２ｍｏｌ）を、非プロトン性極性溶媒としてＮＭＰ　７２５ｇを仕込み、８０℃で３０分間撹拌した。そして水と共沸可能な芳香族炭化水素としてトルエン１５０ｍｌを投入してから温度を上げ約１６０℃で２時間環流させた。水分定量受器に水が約７．２ｍｌ以上たまっていること、水の留出が見られなくなっていることを確認し、水分定量受器にたまっている留出液を除去しながら、約１９０℃まで温度を上げて、トルエンを除去した。その後、溶液を室温に戻し、芳香族ジイソシアネートとしてＭＤＩ　６０．１ｇ（０．２４ｍｏｌ）を投入し、１９０℃で２時間反応させた。反応終了後、アミド基量４．９重量％、ケイ素量２１．７重量％のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液を得た。
【００３３】
実施例１
合成例１のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液　２００ｇ（樹脂固形分３０重量％）とエポキシ樹脂としてＺＸ−１５４８−２（東都化成株式会社製商品名、リン含有多官能エポキシ樹脂）３０ｇ（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、樹脂が均一になるまで約１時間撹拌した後、脱泡のため２４時間、室温で静置してアミド基量６．４重量％、ケイ素量５．６重量％の樹脂組成物ワニスとした。
【００３４】
実施例２
合成例２のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液　２００ｇ（樹脂固形分３５重量％）とエポキシ樹脂としてＺＸ−１５４８−２（東都化成株式会社製商品名、リン含有多官能エポキシ樹脂）３５ｇ（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、樹脂が均一になるまで約１時間撹拌した後、脱泡のため２４時間、室温で静置してアミド基量５．９重量％、ケイ素量８．７重量％の樹脂組成物ワニスとした。
【００３５】
実施例３
合成例３のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液　２００ｇ（樹脂固形分３０重量％）とエポキシ樹脂としてＺＸ−１５４８−２（東都化成株式会社製商品名、リン含有多官能エポキシ樹脂）３０ｇ（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、樹脂が均一になるまで約１時間撹拌した後、脱泡のため２４時間、室温で静置してアミド基量５．７重量％、ケイ素量７．２重量％の樹脂組成物ワニスとした。
【００３６】
実施例４〜６
合成例１のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液　２００ｇ（樹脂固形分３０重量％）とエポキシ樹脂としてＺＸ−１５４８−２（東都化成株式会社製商品名、リン含有多官能エポキシ樹脂）をそれぞれ１２ｇ、３６ｇ、４８ｇ（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をそれぞれ０．２ｇ、０．４ｇ、０．８ｇ配合し、樹脂が均一になるまで約１時間撹拌した後、脱泡のため２４時間、室温で静置し、アミド基量がそれぞれ７．３重量％、６．２重量％、５．８重量％、ケイ素量がそれぞれ６．３重量％、５．４重量％、４．９重量％の樹脂組成物ワニスとした。
【００３７】
比較例１
比較合成例１のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液　２００ｇ（樹脂固形分３５重量％）とエポキシ樹脂としてＺＸ−１５４８−２（東都化成株式会社製商品名、リン含有エポキシ樹脂）３６ｇ（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、樹脂が均一になるまで約１時間撹拌した後、脱泡のため２４時間、室温で静置してアミド基量３．９重量％、ケイ素量１７．４重量％の樹脂組成物ワニスとした。
【００３８】
比較例２
合成例３のシロキサン変性ポリアミドイミド樹脂のＮＭＰ溶液　２００ｇ（樹脂固形分３５重量％）とエポキシ樹脂としてＺＸ−１５４８−２（東都化成株式会社製商品名、リン含有エポキシ樹脂）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　０．８ｇを配合し、樹脂が均一になるまで約１時間撹拌した後、脱泡のため２４時間、室温で静置してアミド基量３．６重量％、ケイ素量４．５重量％の樹脂組成物ワニスとした。
【００３９】
（フィルム及び接着性評価用金属張り積層板の作製）
実施例１〜６及び比較例１、２で作製したワニスを厚さ５０μｍのポリエチレンテレフタレートフィルム（帝人株式会社製商品名ピューレックス）に乾燥後の厚みがそれぞれ１０μｍ、２０μｍになるように塗布し、１３０℃で２０分加熱、乾燥して揮発分５〜７重量％のフィルムを得た。
銅箔（日本電解株式会社製品名ＳＬＰ−１００）、プリプレグ（日立化成工業株式会社製品名Ｉ−６７１）４枚、実施例及び比較例のフィルム、表面粗さＲｚ＝１．８の銅箔（厚さ１８μｍ）を順次重ね、２３０℃、９０分、４．０ＭＰａのプレス条件で両面銅張積層板を作製した。
比較のため、銅箔（日本電解株式会社製品名ＳＬＰ−１００）、プリプレグ（日立化成工業株式会社製品名Ｉ−６７１）４枚を重ね、この上に直接表面粗さＲｚ＝１．８の異なる銅箔（厚さ１８μｍ）を重ね、２３０℃、９０分、４．０ＭＰａのプレス条件で両面銅張積層板を作製した（比較例３）。
【００４０】
（フィルム弾性率及び接着強度の評価）
実施例１〜６及び比較例１、２のフィルムについて動的粘弾性測定装置（レオロジー社製ＤＶＥ）を使用して３０℃での弾性率を測定し結果を表１に示した。
また得られた両面銅張り積層板の銅箔について９０度方向の引き剥がし強さを接着強度として測定し、結果を表１にまとめて示した。実施例１〜６のいずれのフィルムを使用した場合にも０．６〜１．０ｋＮ／ｍであった。アミド基量、ケイ素量及び３０℃での弾性率が本発明の範囲から外れた比較例１やアミド基量、ケイ素量が本発明の範囲から外れた比較例２のフィルムを使用したもの及びフィルムを挟まなかった比較例３では０．１〜０．２ｋＮ／ｍの接着強度しか得られなかった。
【００４１】
【表１】

【００４２】
（はんだ耐熱性の評価）
作製した両面銅張り積層板を２０ｍｍ×２０ｍｍに切断した試料を２６０℃、２８８℃及び３００℃のはんだ浴に浸漬しはんだ耐熱性を測定した。実施例１〜６のフィルムを使用したものは、いずれの温度でも３分以上、ふくれ、剥がれ等の異常が見られなかった。比較例１、２のフィルムを使用したもの及びフィルムを挟まなかったものは６０秒以内にフクレがみられた。
【００４３】
（接着性及び回路形成性の評価）
銅箔（日本電解株式会社製品名ＳＬＰ−１００）、プリプレグ（日立化成工業株式会社製品名Ｉ−６７１）４枚、実施例１又は実施例２の厚み１０μｍのフィルム、表面粗さの異なる銅箔（厚さ１８μｍ）を順次重ね、２３０℃、９０分、４．０ＭＰａのプレス条件で両面銅張積層板を作製した。また比較のために比較例１のフィルムを使用した両面銅張積層板、プリプレグ上に本発明のフィルムを挟まずに積層して比較例３の両面銅張積層板を作製した。表面粗さの異なる銅箔としてはＲｚ＝８．０、Ｒｚ＝５．５、Ｒｚ＝１．８の銅箔及びＲｚ＝２．０の銅箔として電解銅箔の光沢面を使用した。
各両面銅張積層板の表面粗さを変えた銅箔について９０度方向の引き剥がし強さを接着強度として測定した。結果を表２に示した。また、厚み１０μｍのフィルムに代えて厚み２０μｍのフィルムを用いた結果も表２と殆ど同様の傾向を示した。
【００４４】
【表２】

【００４５】
積層板の銅箔側に全面レジストを形成した。また表面粗さを変えた銅箔側に通常のレジストレーションによりＬ／Ｓが２０μｍ／２０μｍ、３０μｍ／３０μｍ、４０μｍ／４０μｍ、５０μｍ／５０μｍの櫛形パターンを形成し、塩化第二鉄水溶液で不要部分の銅をエッチングした後、レジストを剥離して回路を形成した。
得られた回路を顕微鏡観察しラインの形状から回路形成性を評価した。結果を表２に併せて示した。
Ｒｚ＝８．０の銅箔では銅箔粗面に由来する残銅を除去するのに時間がかかり、結果的にラインのトップが細い蒲鉾型となる傾向が見られた。このため４０μｍ／４０μｍが良好な回路を得る限界であった。Ｒｚ＝５．５より表面粗さの小さい銅箔では残銅が短時間で除去でき特にＲｚが２．０以下の銅箔を使用したものでは回路断面は矩形に近づいた。回路形成性も２０μｍ／２０μｍが形成できた。また比較例１のフィルムを使用したものや本発明のフィルムを挟んでいないものは接着強度が低く、エッチングの際に回路に剥離などが起き、部分的に回路形成に至らなかった。
【００４６】
【発明の効果】
本発明における接着フィルムは平滑な金属箔との接着が可能である。Ｂステージ状でプリプレグ等と金属との間に挟みこむことで、接着性を補助するフィルムとして使用することができ、これを用いて得られる金属張り積層板は耐熱性に優れ、微細回路形成性、平滑回路形成性に優れる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin film for bonding and a metal-clad laminate.
[0002]
[Prior art]
The laminate for a printed wiring board is obtained by laminating a predetermined number of prepregs each having an electrically insulating resin composition as a matrix, and heating and pressurizing them to integrate them. When a printed circuit is formed by a subtractive method, a metal-clad laminate is used. This metal-clad laminate is manufactured by laminating a metal foil such as a copper foil on the surface (one or both surfaces) of a prepreg and heating and pressing.
In addition, for flexible wiring boards, heat-pressing is performed by laminating a polyimide sheet with an adhesive in which an adhesive resin composition is laminated on a heat-resistant base material such as polyimide, or a modified polyimide resin having a lowered softening point and a copper foil. Manufactures sheets with copper foil.
As the electrically insulating resin, a thermosetting resin such as a phenol resin, an epoxy resin, a polyimide resin, a bismaleimide-triazine resin is widely used, and a thermoplastic resin such as a fluororesin or a polyphenylene ether resin is used. There is also.
[0003]
[Problems to be solved by the invention]
On the other hand, with the spread of information terminal devices such as personal computers and mobile phones, printed wiring boards mounted thereon have been reduced in size and density. The mounting form is progressing from a pin insertion type to a surface mount type, and further to an area array type represented by a BGA (ball grid array) using a plastic substrate. In a board such as a BGA on which a bare chip is directly mounted, the connection between the chip and the board is generally performed by wire bonding using thermosonic pressure bonding. For this reason, the substrate on which the bare chip is mounted is exposed to a high temperature of 150 ° C. or higher, and the electrically insulating resin needs to have some heat resistance.
In some cases, so-called repairability, in which the chip once mounted is removed, is also required. However, since the same degree of heat is applied as when mounting the chip, the board must be mounted again afterwards. And further heat treatment is applied. Along with this, substrates requiring repairability also require cyclic thermal shock resistance at high temperatures.
[0004]
Furthermore, the number of I / Os of the MPU is increasing with an increase in processing speed, and the number of terminals connected by wire bonding and the terminal width are being narrowed. Adhesion to a metal foil on which a circuit is formed is required to have a higher adhesive strength than before, and a finer roughened shape on the surface of the metal foil is required to produce a finer wiring.
On the other hand, it is considered that the circuit conductor is required to have surface smoothness as the signal frequency increases. Magnetic lines of force are generated in the vicinity of the current in the conductor, but since the interference of the magnetic lines of force is greater at the center of the conductor, the current is concentrated at the periphery and at the corner. This is called the skin effect, and the higher the frequency, the stronger this tendency. It is thought that the smoother the surface of the conductor, the more the resistance increase due to the skin effect can be suppressed.However, the conventional adhesion of the electrically insulating resin is mainly due to the anchor effect on the rough surface, which is inconsistent with the high frequency signal. It has become something.
[0005]
The present invention solves the above-mentioned problems of the prior art, provides a resin sheet having excellent heat resistance and excellent adhesion between a smooth metal foil and a conventional substrate, and further provides a smooth metal foil with this sheet. By providing and laminating between conventional substrates such as a prepreg, an adhesive sheet, a polyimide sheet with an adhesive, and an adhesive polyimide sheet, a metal-clad laminate excellent in forming fine circuits and advantageous in high-frequency characteristics is provided. Things.
[0006]
[Means for Solving the Problems]
That is, the first feature of the present invention is that the resin composition in which the amount of amide groups in the resin composition is 4 to 10% by weight and the resin skeleton contains 1 to 15% by weight of silicon is semi-cured, The gist is a resin film having a size of 30 μm or less.
A second feature of the present invention is that a resin composition having an amide group content of 4 to 10% by weight in a resin composition and containing 1 to 15% by weight of silicon in a resin skeleton is semi-cured. The gist is a resin film having an elastic modulus of 500 to 2500 MPa.
In these resin films, the resin composition preferably contains a siloxane-modified polyamideimide resin and an epoxy resin.
[0007]
A third feature of the present invention is a gist of a metal-clad laminate obtained by sandwiching any one of the resin films of the present invention between a thermosetting resin sheet and a metal foil and heat-curing.
The thermosetting resin sheet is preferably selected from a prepreg, an adhesive sheet, a polyimide sheet with an adhesive, and an adhesive polyimide film, and the surface roughness of the bonding surface of the metal foil with the resin film is 5.5 in Rz. The following is preferred.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Examples of the resin composition containing 4 to 10% by weight of amide groups in the resin composition and containing 1 to 15% by weight of silicon in the resin skeleton to obtain the resin film of the present invention include polyamide imide resin and others. Of a thermosetting resin.
[0009]
First, the polyamideimide resin will be described. Among the polyamideimide resins, a siloxane-modified polyamideimide resin having a siloxane structure in the main chain of the polyamideimide resin is preferable. Further, a siloxane modified compound obtained by reacting an aromatic diisocyanate with a diimide dicarboxylic acid obtained by reacting a siloxane diamine, trimellitic anhydride, and, if necessary, a diamine having three or more aromatic rings. Polyamideimide resins are preferred.
[0010]
In this case, a mixture of a diamine (a) having three or more aromatic rings and a siloxane diamine (b) and trimellitic anhydride (c) are mixed in a molar ratio of {(a) + (b)} / (c). ) = 1.0 / 2.0 to 1.0 / 2.2.
The mixture containing the obtained diimide dicarboxylic acid and the aromatic diisocyanate (d) are mixed in a molar ratio of {(a) + (b)} / (d) = 1.0 / 1.0 to 1.0 / More preferably, it is a siloxane-modified polyamideimide obtained by reacting at 1.5.
In general, the mixing ratio of the diamine (a) having three or more aromatic rings and the siloxane diamine (b) is preferably (a) / (b) = 99.9 / 0.1 to 0/100 in a molar ratio. It is particularly preferable to select according to the amine equivalent of the siloxane diamine (b) to be used. (A) / (b) = 99.9 / 0.1-0 / 100 (molar ratio; the same applies hereinafter) when the amine equivalent of the siloxane diamine is 400-500, and (a) when the amine equivalent is 800-1000. /(B)=99.9/0.1 to 60/40, and good characteristics when (a) / (b) = 99.9 / 0.1 to 60/40 when the amine equivalent is 1500 to 1600. Can be obtained.
[0011]
(A) As the diamine having three or more aromatic rings used in the present invention, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (hereinafter abbreviated as BAPP), 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, , 3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, etc., which can be used alone or in combination. It can be used in conjunction seen. BAPP is particularly preferred over other diamines in terms of the balance between the properties of the polyamideimide resin and the cost. The preferred range of the number of aromatic rings is about 3 to 6.
[0012]
(B) As the siloxane diamine used in the present invention, those represented by the following formula (1) are preferably used.
Embedded image

R in the general formula (1 formula) ₁₀ , R ₁₁ Represents a divalent organic group; ₁₂ ~ R _Fifteen Represents an alkyl group, a phenyl group or a substituted phenyl group, and n represents an integer of 1 to 15.
[0013]
Among these, amino-modified silicone oils X-22-161AS (amine equivalent 450), X-22-161A (amine equivalent 840), and X-22-161B (amine equivalent 1500) (which are dimethylsiloxane-based both terminal amines) Shin-Etsu Chemical Co., Ltd.), BY16-853 (amine equivalent 650), BY16-853B (amine equivalent 2200) (both trade names, manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like may be used as commercially available products. Can be. These can be used alone or in combination.
[0014]
(D) As the aromatic diisocyanate used in the present invention, 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5- Examples thereof include diisocyanate and 2,4-tolylene dimer. These can be used alone or in combination.
In the present invention, it is preferred that the diimide dicarboxylic acid and the aromatic diisocyanate are reacted at a molar ratio of 1.0 / 1.0 to 1.0 / 1.5, and the molar ratio of the aromatic diisocyanate is less than 1.0. Is not preferred because the flexibility of the siloxane-modified polyamide-imide resin is lowered, and the same is not true even if the molar ratio of the aromatic diisocyanate exceeds 1.5, which is not preferable.
[0015]
An example of a method for producing such a siloxane-modified polyamide-imide resin will be described below. A diamine having three or more aromatic rings, siloxane diamine and trimellitic anhydride (TMA) are reacted at 50 to 90 ° C. in the presence of an aprotic polar solvent such as N-methyl-2-pyrrolidone. Then, an aromatic hydrocarbon capable of azeotroping with water such as toluene is added at a mass ratio of 0.1 to 0.5 of an aprotic polar solvent, and the reaction is carried out at 120 to 180 ° C. to obtain a solution containing diimidedicarboxylic acid. Get. Preferably, the temperature is now increased to about 190 ° C. to remove the aromatic hydrocarbons from the solution. Next, the solution is returned to room temperature, an aromatic diisocyanate is charged, and the mixture is reacted at about 190 ° C. for about 2 hours to obtain a solution of a polyamideimide resin having a siloxane structure in a polar solvent.
[0016]
Next, the thermosetting resin used in the present invention will be described.
In the present invention, a thermosetting resin having an organic group capable of reacting with an amide group in the polyamideimide resin is preferable. Examples of the thermosetting resin include an epoxy resin, a polyimide resin, an unsaturated polyester resin, a polyurethane resin, a bismaleimide resin, a triazine-bismaleimide resin, and a phenol resin. An epoxy resin having a glycidyl group is more preferable. It is preferable to use 1 to 200 parts by weight of the thermosetting resin based on 100 parts by weight of the polyamideimide resin.
In the present invention, the polyamide imide resin and the thermosetting resin are blended so that the amount of the amide group in the resin composition is finally 4 to 10% by weight and the resin skeleton contains 1 to 15% by weight of silicon.
For example, when the amide group content of the polyamide imide resin used is PA weight%, the silicon content in the resin skeleton is PB weight%, the amide content of the thermosetting resin is EA weight%, and the silicon content in the resin skeleton is EB weight%, The thermosetting resin C parts by weight with respect to the resin 100 parts by weight is selected from a range satisfying the following relationship.
4 ≦ (PA × 100 + EA × C) / (100 + C) ≦ 10
1 ≦ (PB × 100 + EB × C) / (100 + C) ≦ 15
[0017]
In the present invention, the use of an epoxy resin as a thermosetting resin can be cured at a temperature of 180 ° C. or less, and reacts with an amide group of a polyamideimide resin to improve thermal, mechanical, and electrical properties. Therefore, an epoxy resin having two or more glycidyl groups and a curing agent thereof, an epoxy resin having two or more glycidyl groups and a curing accelerator thereof, or an epoxy resin having two or more glycidyl groups and a curing agent It is preferable to use a curing accelerator. Also, the more glycidyl groups, the better, and more preferably three or more. The compounding amount varies depending on the number of glycidyl groups, and the compounding amount may be smaller as the glycidyl group is larger.
[0018]
Examples of the epoxy resin include polyglycidyl ether obtained by reacting polychlorophenol such as bisphenol A, novolak type phenol resin, orthocresol novolak type phenol resin or polyhydric alcohol such as 1,4-butanediol with epichlorohydrin, and phthalic acid. And polyglycidyl esters, N-glycidyl derivatives of amines, amides or compounds having a heterocyclic nitrogen base, which are obtained by reacting epichlorohydrin with a polybasic acid such as hexahydrophthalic acid, and alicyclic epoxy resins.
[0019]
The curing agent and curing accelerator for the epoxy resin to be blended in the resin composition are not limited as long as they react with the epoxy resin or promote the curing. For example, amines, imidazoles, and polyfunctional phenols , Acid anhydrides and the like can be used.
As amines, dicyandiamide, diaminodiphenylmethane, guanylurea and the like can be used. As polyfunctional phenols, hydroquinone, resorcinol, bisphenol A and their halogen compounds, novolak-type phenol resin which is a condensate with formaldehyde, resol-type Phenol resins and the like can be used, and as acid anhydrides, phthalic anhydride, benzophenonetetracarboxylic dianhydride, methylhymic acid, and the like can be used. As the curing accelerator, imidazoles such as alkyl-substituted imidazole and benzimidazole can be used.
[0020]
In the case of amines, the necessary amount of these curing agents or curing accelerators is preferably such that the equivalent of the active hydrogen of the amine is substantially equal to the epoxy equivalent of the epoxy resin. In the case of imidazole, which is a curing accelerator, the equivalent ratio to active hydrogen is not simply determined, but is empirically 0.001 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin. In the case of polyfunctional phenols or acid anhydrides, the phenolic hydroxyl group or carboxyl group is 0.6 to 1.2 equivalents to 1 equivalent of the epoxy resin. If the amount of these curing agents or curing accelerators is small, uncured epoxy resin remains and the Tg (glass transition temperature) decreases. If the amount is too large, unreacted curing agents and curing accelerators remain and insulating properties are reduced. Decreases. The epoxy equivalent of the epoxy resin is preferably taken into consideration because it can also react with the amide group of the siloxane-modified polyamideimide resin.
[0021]
Further, a filler, a coupling agent, a flame retardant and the like which are usually added to the resin composition can be appropriately added to the resin composition of the present invention as long as the effects of the present invention are not impaired.
[0022]
The first resin film of the present invention and the second resin film of the present invention (hereinafter, referred to as the resin film of the present invention) have an amide group content of 4 to 10% by weight and contain 1 to 15 silicon atoms in the resin skeleton. The above resin composition containing by weight is semi-cured. In particular, the first resin film of the present invention has a thickness after drying of 30 μm or less. When the thickness after drying is 30 μm or less, generation of stress is small, and warpage can be reduced.
The second resin film of the present invention has an elastic modulus at 30 ° C of 500 to 2500 MPa. When it is 500 MPa or more, the adhesiveness becomes good, and when it is 2500 MPa or less, the thermal stress becomes good.
[0023]
The resin film of the present invention is preferably formed by forming a layer of the resin composition on one surface of a substrate and drying it in a semi-cured (B stage) state, particularly from the viewpoint of storage stability and workability. Here, it is more preferable that the resin composition is applied to a substrate in the form of a varnish obtained by mixing, dissolving, and dispersing in an organic solvent to form a layer. Examples of such an organic solvent are not limited as long as solubility can be obtained, and include dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, sulfolane, cyclohexanone, and the like. Can be
The substrate on which the resin composition is applied to form a layer of the resin composition is not particularly limited as long as the resin film can be peeled off when the resin film is laminated with a metal foil or the like in the next step. Usually, polyethylene terephthalate or aluminum foil in the form of a sheet, or a substrate obtained by subjecting the surface of the substrate to a release treatment is used. A polyethylene terephthalate film having a thickness of 30 µm to 200 µm and subjected to a release treatment is particularly preferably used.
[0024]
Although the production conditions of the resin film are not particularly limited, it is preferable that the solvent used for the varnish is volatilized by 80% by weight or more. For this reason, the production method and drying conditions are not limited, and the drying temperature is generally 80 ° C. to 180 ° C. The drying time is not particularly limited in view of the gel time of the varnish.
[0025]
When the above resin composition containing a siloxane-modified polyamideimide resin and a thermosetting resin is used for the resin composition for obtaining the resin film of the present invention, the varnish solvent volatilization rate is high, and the thermosetting resin is cured. A resin film is obtained in which the residual solvent content can be reduced to 5% by weight or less even at a low temperature of 150 ° C. or less that does not promote the reaction. For example, when used as a heat-resistant adhesive sheet between a smooth metal and a prepreg, an adhesive sheet, a polyimide sheet with an adhesive, an adhesive polyimide sheet, etc., good adhesion can be obtained. This is because the polyamideimide resin with high heat resistance is modified with siloxane, and the residual solvent content can be reduced to prevent blistering due to solvent evaporation in the lamination process with copper foil, Excellent.
[0026]
The metal-clad laminate of the present invention is obtained by heating and curing the resin film of the present invention between a thermosetting resin sheet and a metal foil.
The manufacturing method of the metal-clad laminate is as follows. A metal foil, a resin film of the present invention, and a thermosetting resin sheet or a laminate obtained by laminating a plurality of the thermosetting resin sheets are laminated, usually at a temperature in the range of 150 to 280 ° C, preferably 180 to 250 ° C, and usually 0 The metal-clad laminate can be manufactured by heating and pressing at a pressure in the range of 0.5 to 20 MPa, preferably 1 to 8 MPa. By using a metal foil to form a metal-clad laminate, circuit processing can be performed on the laminate to form a printed circuit board.
[0027]
As the thermosetting resin sheet, a prepreg, an adhesive sheet, a polyimide sheet with an adhesive, an adhesive polyimide sheet, and the like can be used.In each case, according to the case of the thermosetting resin sheet, the resin film of the present invention is used. The metal foil laminate can be manufactured by sandwiching and heating and pressing.
[0028]
As the metal foil used in the present invention, a copper foil or an aluminum foil is generally used, but a foil having a thickness of 5 to 200 μm, which is usually used for a laminate, can be used. Further, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and a copper layer of 0.5 to 15 μm and a copper layer of 10 to 300 μm are provided on both surfaces thereof. A composite foil having a three-layer structure or a two-layer composite foil obtained by combining aluminum and copper foil can be used. It is preferable to use a metal foil having a surface roughness Rz of 5.5 or less from the viewpoint of obtaining a fine circuit forming property and high frequency characteristics due to the adhesiveness of the present invention. More preferred.
[0029]
【Example】
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.
(Synthesis example 1)
In a 1-liter separable flask equipped with a faucet connected to a reflux condenser and having a 25-ml water content receiver, thermometer and stirrer
43.1 g (0.105 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (hereinafter, referred to as BAPP) as a diamine having three or more aromatic rings,
40.1 g (0.045 mol) of reactive silicone oil KF8010 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 445) as siloxane diamine,
60.5 g (0.315 mol) of TMA (trimellitic anhydride),
440 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) as an aprotic polar solvent
And stirred at 80 ° C. for 30 minutes.
Then, 100 ml of toluene was charged as an aromatic hydrocarbon azeotropic with water, and then the temperature was increased and the mixture was refluxed at about 160 ° C. for 2 hours. After confirming that about 5.4 ml or more of water has accumulated in the moisture quantification receiver and that distilling of water has not been observed, about 190 m The temperature was raised to ° C. to remove the toluene. Thereafter, the solution was returned to room temperature, 45.1 g (0.18 mol) of 4,4'-diphenylmethane diisocyanate (hereinafter, referred to as MDI) was charged as an aromatic diisocyanate, and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of a siloxane-modified polyamideimide resin having an amide group content of 8.1% by weight and a silicon amount of 6.9% by weight was obtained.
[0030]
(Synthesis example 2)
41.1 g (0.1 mol) of BAPP as a diamine having three or more aromatic rings in a 1 liter separable flask equipped with a faucet connected to a reflux condenser with a 25 ml water content receiver, a thermometer and a stirrer, 90.0 g (0.10 mol) of reactive silicone oil KF8010 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent: 450) and 80.7 g (0.42 mol) of TMA (trimellitic anhydride) as siloxane diamine, 505 g of NMP was charged as a polar solvent and stirred at 80 ° C. for 30 minutes. Then, 100 ml of toluene was added as an aromatic hydrocarbon capable of azeotropic distillation with water, and then the temperature was increased and refluxed at about 160 ° C. for 2 hours. After confirming that about 7.2 ml or more of water has accumulated in the moisture quantification receiver and that no distilling of water has been observed, while removing the distillate accumulated in the moisture quantification receiver, about 190 ml The temperature was raised to ° C. to remove the toluene. Thereafter, the solution was returned to room temperature, 60.1 g (0.24 mol) of MDI was charged as an aromatic diisocyanate, and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of a siloxane-modified polyamideimide resin having an amide group content of 7.4% by weight and a silicon amount of 10.9% by weight was obtained.
[0031]
(Synthesis example 3)
55.4 g (0.135 mol) of BAPP as a diamine having three or more aromatic rings in a 1-liter separable flask equipped with a faucet connected to a reflux condenser with a 25-ml water content receiver, a thermometer and a stirrer, 46.8 g (0.015 mol) of reactive silicone oil X-22-161B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent: 1560), 60.5 g (0.315 mol) of TMA (trimellitic anhydride) as siloxane diamine Was charged with 485 g of NMP as an aprotic polar solvent, and stirred at 80 ° C. for 30 minutes. Then, 100 ml of toluene was charged as an aromatic hydrocarbon azeotropic with water, and then the temperature was increased and the mixture was refluxed at about 160 ° C. for 2 hours. After confirming that about 5.4 ml or more of water has accumulated in the moisture quantification receiver and that distilling of water has not been observed, about 190 m The temperature was raised to ° C. to remove the toluene. Thereafter, the solution was returned to room temperature, 45.1 g (0.18 mol) of MDI was charged as an aromatic diisocyanate, and reacted at 190 ° C. for 2 hours. After the reaction, an NMP solution of a siloxane-modified polyamideimide resin having an amide group content of 7.2% by weight and a silicon amount of 9.0% by weight was obtained.
[0032]
(Comparative Synthesis Example 1)
24.6 g (0.06 mol) of BAPP as a diamine having three or more aromatic rings in a 2 liter separable flask equipped with a faucet connected to a reflux condenser with a 25 ml water content receiver, a thermometer and a stirrer, 225.4 g (0.14 mol) of reactive silicone oil X-22-161A (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., amine equivalent 805) as a siloxane diamine, 80.7 g (0.42 mol) of TMA (trimellitic anhydride) Was charged with 725 g of NMP as an aprotic polar solvent, and stirred at 80 ° C. for 30 minutes. Then, 150 ml of toluene was charged as an aromatic hydrocarbon azeotropic with water, and then the temperature was increased and refluxed at about 160 ° C. for 2 hours. After confirming that about 7.2 ml or more of water has accumulated in the moisture quantification receiver and that no distilling of water has been observed, while removing the distillate accumulated in the moisture quantification receiver, about 190 ml The temperature was raised to ° C. to remove the toluene. Thereafter, the solution was returned to room temperature, 60.1 g (0.24 mol) of MDI was charged as an aromatic diisocyanate, and reacted at 190 ° C. for 2 hours. After completion of the reaction, an NMP solution of a siloxane-modified polyamideimide resin having an amide group content of 4.9% by weight and a silicon amount of 21.7% by weight was obtained.
[0033]
Example 1
200 g of an NMP solution of the siloxane-modified polyamide-imide resin of Synthesis Example 1 (resin solid content of 30% by weight) and 30 g of ZX-1548-2 (trade name, manufactured by Toto Kasei Co., Ltd., phosphorus-containing polyfunctional epoxy resin) as an epoxy resin Dimethylacetamide solution of 50% by weight) and 0.3 g of 2-ethyl-4-methylimidazole, and the mixture was stirred for about 1 hour until the resin became homogeneous, and then left at room temperature for 24 hours for defoaming. Thus, a resin composition varnish having an amide group content of 6.4% by weight and a silicon amount of 5.6% by weight was obtained.
[0034]
Example 2
200 g of an NMP solution of the siloxane-modified polyamideimide resin of Synthesis Example 2 (resin solid content: 35% by weight) and 35 g of ZX-1548-2 (trade name, manufactured by Toto Kasei Co., Ltd., phosphorus-containing polyfunctional epoxy resin) as an epoxy resin (resin solid) Dimethylacetamide solution of 50% by weight) and 0.3 g of 2-ethyl-4-methylimidazole, and the mixture was stirred for about 1 hour until the resin became homogeneous, and then left at room temperature for 24 hours for defoaming. Thus, a resin composition varnish having an amide group content of 5.9% by weight and a silicon amount of 8.7% by weight was obtained.
[0035]
Example 3
200 g of an NMP solution of the siloxane-modified polyamideimide resin of Synthesis Example 3 (resin solid content: 30% by weight) and 30 g of ZX-1548-2 (trade name, manufactured by Toto Kasei Co., Ltd., phosphorus-containing polyfunctional epoxy resin) as an epoxy resin (resin solid) Dimethylacetamide solution of 50% by weight) and 0.3 g of 2-ethyl-4-methylimidazole, and the mixture was stirred for about 1 hour until the resin became homogeneous, and then left at room temperature for 24 hours for defoaming. Thus, a resin composition varnish having an amide group content of 5.7% by weight and a silicon amount of 7.2% by weight was obtained.
[0036]
Examples 4 to 6
200 g of an NMP solution of the siloxane-modified polyamideimide resin of Synthesis Example 1 (resin solid content: 30% by weight) and 12 g of ZX-1548-2 (trade name, manufactured by Toto Kasei Co., Ltd., phosphorus-containing polyfunctional epoxy resin) as an epoxy resin, 36 g, 48 g (resin solid content of 50% by weight in dimethylacetamide solution) and 0.2 g, 0.4 g and 0.8 g of 2-ethyl-4-methylimidazole were blended, respectively, and stirred for about 1 hour until the resin became uniform. Then, the mixture was allowed to stand at room temperature for 24 hours for defoaming, and the amide group content was 7.3% by weight, 6.2% by weight, 5.8% by weight, and the silicon amount was 6.3% by weight, respectively. A resin composition varnish of 0.4% by weight and 4.9% by weight was obtained.
[0037]
Comparative Example 1
NMP solution of siloxane-modified polyamideimide resin of Comparative Synthesis Example 1 (200 g, resin solid content: 35% by weight) and ZX-1548-2 (trade name, manufactured by Toto Kasei Co., Ltd., phosphorus-containing epoxy resin) as an epoxy resin, 36 g (resin solid content) 50% by weight of dimethylacetamide solution) and 0.3 g of 2-ethyl-4-methylimidazole, and the mixture was stirred for about 1 hour until the resin became uniform, and then left at room temperature for 24 hours for defoaming. A resin composition varnish having an amide group content of 3.9% by weight and a silicon amount of 17.4% by weight was obtained.
[0038]
Comparative Example 2
200 g of an NMP solution of the siloxane-modified polyamide-imide resin of Synthesis Example 3 (resin solid content: 35% by weight) and 120 g of ZX-1548-2 (trade name, manufactured by Toto Kasei Co., Ltd., phosphorus-containing epoxy resin) as an epoxy resin (resin solid content: 50 % Dimethylacetamide solution) and 0.8 g of 2-ethyl-4-methylimidazole, and the mixture was stirred for about 1 hour until the resin became homogeneous. A resin composition varnish having a base amount of 3.6% by weight and a silicon amount of 4.5% by weight was obtained.
[0039]
(Production of film and metal-clad laminate for evaluation of adhesion)
The varnishes prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were applied to a 50 μm thick polyethylene terephthalate film (Purex, trade name, manufactured by Teijin Limited) so that the thickness after drying was 10 μm and 20 μm, respectively. The film was heated and dried at 130 ° C. for 20 minutes to obtain a film having a volatile content of 5 to 7% by weight.
Copper foil (Nihon Electrolysis Co., Ltd. product name SLP-100), 4 prepregs (Hitachi Chemical Industry Co., Ltd. product name I-671), films of Examples and Comparative Examples, copper foil of surface roughness Rz = 1.8 ( (Thickness: 18 μm) was successively stacked, and a double-sided copper-clad laminate was produced under pressing conditions of 230 ° C., 90 minutes, and 4.0 MPa.
For comparison, a copper foil (Nihon Electrolysis Co., Ltd. product name SLP-100) and a prepreg (Hitachi Kasei Kogyo Co., Ltd. product name I-671) were superimposed, and the surface roughness Rz = 1.8 was different directly on this. A copper foil (thickness: 18 μm) was stacked, and a double-sided copper-clad laminate was produced under the pressing conditions of 230 ° C., 90 minutes, and 4.0 MPa (Comparative Example 3).
[0040]
(Evaluation of film elastic modulus and adhesive strength)
The elastic modulus of the films of Examples 1 to 6 and Comparative Examples 1 and 2 at 30 ° C. was measured using a dynamic viscoelasticity measuring device (DVE manufactured by Rheology), and the results are shown in Table 1.
The peel strength of the obtained double-sided copper-clad laminate in the direction of 90 ° was measured as the adhesive strength, and the results are shown in Table 1. It was 0.6 to 1.0 kN / m when any of the films of Examples 1 to 6 was used. A film using the film of Comparative Example 1 in which the amide group amount, the silicon amount and the elastic modulus at 30 ° C. are out of the range of the present invention and the film of Comparative Example 2 in which the amide group amount and the silicon amount are out of the range of the present invention In Comparative Example 3 in which no was sandwiched, only an adhesive strength of 0.1 to 0.2 kN / m was obtained.
[0041]
[Table 1]

[0042]
(Evaluation of solder heat resistance)
A sample obtained by cutting the produced double-sided copper-clad laminate into 20 mm × 20 mm was immersed in a solder bath at 260 ° C., 288 ° C. and 300 ° C., and the solder heat resistance was measured. In the case of using the films of Examples 1 to 6, no abnormalities such as blistering and peeling were observed for 3 minutes or more at any temperature. In the case where the films of Comparative Examples 1 and 2 were used and the case where the films were not sandwiched, blisters were observed within 60 seconds.
[0043]
(Evaluation of adhesion and circuit formability)
Copper foil (Nihon Electrolysis Co., Ltd. product name SLP-100), 4 prepregs (Hitachi Chemical Industry Co., Ltd. product name I-671), 10 μm thick film of Example 1 or Example 2, copper foil with different surface roughness (Thickness: 18 μm) were sequentially stacked, and a double-sided copper-clad laminate was produced under pressing conditions of 230 ° C., 90 minutes, and 4.0 MPa. For comparison, the double-sided copper-clad laminate of Comparative Example 3 was prepared by laminating the double-sided copper-clad laminate using the film of Comparative Example 1 on a prepreg without sandwiching the film of the present invention. As the copper foil having different surface roughness, a glossy surface of an electrolytic copper foil was used as a copper foil having Rz = 8.0, Rz = 5.5, Rz = 1.8 and a copper foil having Rz = 2.0.
The peel strength in the 90-degree direction was measured as the adhesive strength of the copper foil having the surface roughness of each double-sided copper-clad laminate changed. The results are shown in Table 2. Also, the results obtained by using a film having a thickness of 20 μm in place of the film having a thickness of 10 μm showed almost the same tendency as in Table 2.
[0044]
[Table 2]

[0045]
A resist was entirely formed on the copper foil side of the laminate. In addition, a comb-shaped pattern having an L / S of 20 μm / 20 μm, 30 μm / 30 μm, 40 μm / 40 μm, 50 μm / 50 μm is formed on the copper foil side having changed surface roughness by ordinary registration, and unnecessary portions are formed with an aqueous ferric chloride solution. After the copper was etched, the resist was peeled off to form a circuit.
The obtained circuit was observed under a microscope, and the circuit formability was evaluated from the line shape. The results are shown in Table 2.
In the case of the copper foil of Rz = 8.0, it took time to remove the residual copper derived from the copper foil rough surface, and as a result, a tendency was observed that the top of the line became a thin kamaboko type. For this reason, 40 μm / 40 μm was the limit for obtaining a good circuit. In the case of copper foil having a surface roughness smaller than Rz = 5.5, residual copper could be removed in a short time, and in particular, in the case of using a copper foil having an Rz of 2.0 or less, the circuit cross section approached a rectangular shape. The circuit formability was also 20 μm / 20 μm. Further, those using the film of Comparative Example 1 and those not sandwiching the film of the present invention had low adhesive strength, peeled off the circuit during etching, and did not partially form the circuit.
[0046]
【The invention's effect】
The adhesive film in the present invention can be bonded to a smooth metal foil. By sandwiching between a prepreg or the like and metal in a B-stage shape, it can be used as a film to assist adhesiveness, and a metal-clad laminate obtained using this film has excellent heat resistance, Excellent in forming a smoothing circuit.

Claims (6)

A resin film having an amide group content of 4 to 10% by weight in a resin composition and a semi-cured resin composition containing 1 to 15% by weight of silicon in a resin skeleton and having a thickness of 30 μm or less. A resin composition having an amide group content of 4 to 10% by weight in a resin composition and containing 1 to 15% by weight of silicon in a resin skeleton is semi-cured, and has an elastic modulus at 30 ° C of 500 to 2500 MPa. Resin film. The resin film according to claim 1, wherein the resin composition includes a siloxane-modified polyamideimide resin and an epoxy resin. A metal-clad laminate obtained by heating and curing the resin film according to claim 1 between a thermosetting resin sheet and a metal foil. The metal-clad laminate according to claim 4, wherein the thermosetting resin sheet is selected from a prepreg, an adhesive sheet, a polyimide sheet with an adhesive, and an adhesive polyimide film. The metal-clad laminate according to claim 4 or 5, wherein the surface roughness of the bonding surface of the metal foil to the resin film is 5.5 or less in Rz.