JP4144454B2 - Insulating film composition, insulating film, and method of forming insulating film - Google Patents

Description

（式中、Ｒ_１は２価の炭化水素基又は芳香族基を示し、Ｒ_２は独立に１価の炭素水素基又は芳香族基を示し、ｎ１は３〜５０の整数を示す。）
また、エポキシ基との反応性を有する置換基が、カルボキシル基または水酸基であること、硬化促進剤を、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部に対して０．１〜１０重量部含有すること、硬化促進剤が３級アミン類であること、（ｅ）微細フィラーを２０〜１５０重量部含有すること、微細なフィラーが、微粉状シリカとタルク、マイカあるいは硫酸バリウムの少なくとも一種とを組み合わせたものであることに関する。
さらに、前記の絶縁膜用組成物を加熱処理して得られる硬化絶縁膜、および、前記の絶縁膜用組成物を基材に塗布後、５０℃〜２１０℃で加熱処理して硬化絶縁膜を形成する方法に関する。
【００１０】
【発明の実施の形態】
エポキシ基との反応性を有し且つポリシロキサン骨格を含有した樹脂を主成分とし、これにエポキシ化合物を加えた組成物は、加熱処理による架橋反応によって柔軟性が高い硬化絶縁膜を形成することができる。しかし、この硬化絶縁膜は、主成分を構成する樹脂に含有されたポリシロキサン骨格がエポキシ樹脂などの有機材料に対して密着性が低いので封止材料に対して密着性が劣ると考えられ、また封止材料との密着性を向上させると考えられるエポキシ化合物は少量成分であり且つ硬化絶縁膜では既に架橋構造を形成しているから、封止材料との密着性向上に対して充分な役割を果たし得ないと考えられた。
【００１１】
本発明の絶縁膜用組成物は、主成分を構成する樹脂にはポリシロキサン骨格が含有され更にエポキシ化合物は少量成分であるにもかかわらず、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有した樹脂におけるエポキシ基との反応性を有する置換基とエポキシ化合物のエポキシ基との数量比が１：１〜１３：１、好ましくは２：１〜１２：１の範囲内になるように構成することによって、封止材料との密着性を改良したことを一つの特徴とするものである。
本発明において、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有した樹脂におけるエポキシ基との反応性を有する置換基とは、前記樹脂の高分子鎖に置換基として導入されたものであって、高分子鎖の末端の反応性基は含まない。
【００１２】
硬化絶縁膜と封止材料との密着性について具体的に説明する。電子部品の実装工程において、通常、まず絶縁膜用組成物は基材に塗布後加熱処理されて硬化絶縁膜が形成され、次いでその硬化絶縁膜と接して液状の封止材料が塗布などによって配置され、加熱処理によって封止材料が硬化される。硬化絶縁膜と硬化した封止材料との界面は充分な密着性が要求される。さもないと、硬化絶縁膜と封止材料とが導線やチップ部品などを保護する役割を果たすことができない。
封止材料の主成分はエポキシ樹脂とノボラック樹脂とからなり極性成分（特にエポキシ基）を多く含むから、硬化絶縁膜が封止材料の極性成分と化学的又は物理的な相互作用を有するものを適当量含んでいれば、封止材料との界面で封止材料と緊密な化学的又は物理的な相互作用が可能となり、硬化絶縁膜は封止材料との密着性が向上すると考えられる。本発明において、硬化絶縁膜と封止材料との緊密な化学的又は物理的相互作用を可能にするものは、硬化後に絶縁硬化膜に残存した、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる樹脂中のエポキシ基との反応性を有する置換基である。
【００１３】
エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる樹脂中のエポキシ基との反応性を有する置換基は、絶縁硬化膜の硬化過程でエポキシ化合物のエポキシ基との架橋反応によって消費されるから、絶縁硬化膜に残存する前記エポキシ基との反応性を有する置換基の数量は、組成物中のエポキシ化合物の配合量によって変化する。エポキシ化合物の配合量が多くなると、絶縁硬化膜に残存するエポキシ基と反応性を有する置換基は減少し、また残存したエポキシ基と反応性を有する置換基も多量のエポキシ化合物によって形成されるより密な架橋構造中に組み込まれて自由な動きが抑制されるから、封止材料との界面で封止材料と緊密な化学的又は物理的な相互作用を果たすことができず、封止材料に対する密着性は低下する。一方、エポキシ化合物の配合量が少な過ぎると、必要な密度の架橋構造が得られなくて硬化絶縁膜の耐溶剤性や耐熱性が低下する。
【００１４】
本発明は、（ａ）エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部、（ｂ）エポキシ化合物０．５〜３０重量部、及び、（Ｃ）有機溶媒を含有してなる絶縁膜用組成物において、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有した樹脂におけるエポキシ基との反応性を有する置換基とエポキシ化合物のエポキシ基の数量比を１：１〜１３：１、特に２：１〜１２：１になるように構成すると、得られる硬化絶縁膜は封止材料に対する密着性が優れ且つ耐溶剤性や耐熱性も満足できるものであることを見出してなされたものである。前記エポキシ基との反応性を有する置換基がエポキシ化合物のエポキシ基に比べて数量比で１未満になると、封止材料に対する密着性が低下し、また１３を越えると耐溶剤性や耐熱性が充分ではなくなるから好ましくない。
【００１５】
本発明において、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂は、高分子鎖の末端基又は高分子鎖の置換基として、芳香族ジカルボン酸無水物基、芳香族ジカルボン酸ハーフエステル基、カルボン酸基、水酸基、アミド基などの、エポキシ基と常温では実質的な硬化反応が起らず、例えば８０℃以上の比較的高温において硬化反応が起こり得る基を有しており、且つ高分子鎖がポリシロキサン骨格を含有した樹脂、好ましくは耐熱性や耐薬品性などの観点から、前記高分子鎖がフレキシブルなポリシロキサン骨格とベンゼン環やイミド環などのリジッドなセグメントとを含有した樹脂である。
本発明において、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂は、限定するものではないが、次に示すようなポリイミドシロキサンが特に好適である。以下、ポリイミドシロキサンを例に挙げて本発明を説明する。
【００１６】
本発明におけるエポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂として好適なポリイミドシロキサンは、好ましくは、テトラカルボン酸成分と、ジアミノポリシロキサン４５〜９５モル％好ましくは６０〜９５モル％、エポキシ基との反応性を有する置換基を持った芳香族ジアミン０．５〜４０モル％、及び、前記ジアミノポリシロキサン及び前記エポキシ基との反応性を有する置換基を持った芳香族ジアミン以外のジアミン０〜５４．５モル％（通常、０〜３０モル％）とからなるジアミン成分とを、略等モル好ましくはジアミン成分１モルに対してテトラカルボン酸成分が１．０〜１．２モル程度の割合で用いて有機溶媒中で反応して得ることができる。テトラカルボン酸成分が前記より多すぎると得られるポリイミドシロキサン絶縁膜用組成物の印刷特性が低下するので好ましくない。
【００１７】
ポリイミドシロキサンのテトラカルボン酸成分としては、具体的には、２，３，３’，４’−ビフェニルテトラカルボン酸、３，３’，４，４’−ビフェニルテトラカルボン酸、３，３’，４，４’−ジフェニルエ−テルテトラカルボン酸、３，３’，４，４’−ジフェニルスルホンテトラカルボン酸、３，３’，４，４’−ベンゾフェノンテトラカルボン酸、２，２−ビス（３，４−ベンゼンジカルボン酸）ヘキサフルオロプロパン、ピロメリット酸、１，４−ビス（３，４−ベンゼンジカルボン酸）ベンゼン、２，２−ビス〔４−（３，４−フェノキシジカルボン酸）フェニル〕プロパン、２，３，６，７−ナフタレンテトラカルボン酸、１，２，５，６−ナフタレンテトラカルボン酸、１，２，４，５−ナフタレンテトラカルボン酸、１，４，５，８−ナフタレンテトラカルボン酸、１，１−ビス（２，３−ジカルボキシフェニル）エタンなどの芳香族テトラカルボン酸、又は、それらの酸二無水物や低級アルコ−ルのエステル化物、及び、シクロペンタンテトラカルボン酸、１，２，４，５−シクロヘキサンテトラカルボン酸、３−メチル−４−シクロヘキセン−１，２，４，５−テトラカルボン酸などの脂環族系テトラカルボン酸、又は、それらの酸二無水物や低級アルコ−ルのエステル化物を好適に挙げることができる。これらのなかでも特に、２，３，３’，４’−ビフェニルテトラカルボン酸、及び、３，３’，４，４’−ジフェニルエ−テルテトラカルボン酸、又は、それらの酸二無水物や低級アルコ−ルのエステル化物は、ポリイミドシロキサンとしたときの有機溶媒に対する溶解性が優れているので好適である。
また、本発明において、ポリイミドシロキサンのテトラカルボン酸成分中に、前記で例示したような芳香族テトラカルボン酸成分を８０モル％以上特に８５％〜１００％含有することが好ましい。
【００１８】
本発明におけるポリイミドシロキサンのテトラカルボン酸成分は、ジアミンと反応させることが容易なテトラカルボン酸二無水物を用いることが好ましい。
また、テトラカルボン酸二無水物の使用量がジアミンに対して１．０５倍モル以上で未反応無水環が残存するような場合には、そのままでもよいが、エステル化剤で開環ハーフエステル化してもよい。エステル化剤であるアルコール類の使用量は、過剰なテトラカルボン酸二無水物の１．１〜２０倍当量、特に、１．５〜５倍当量であることが好ましい。アルコール類の割合が少ないと、未反応の無水環が残って、組成物での貯蔵安定性が劣るものとなり、過剰のアルコール類は不溶分が析出したり貧溶媒となって固形分濃度を低くすることになって印刷による塗膜の形成が容易でなくなるので好ましくない。
エステル化剤を用いた場合は、反応溶液をそのまま用いても構わないが、過剰のアルコール類を加熱や減圧留去して使用することもできる。
【００１９】
本発明において、ポリイミドシロキサンのジアミン成分は、下記一般式（１）で示されるジアミノポリシロキサン４５〜９５モル％好ましくは６０〜９５モル％、エポキシ基との反応性を有する置換基を持った芳香族ジアミン０．５〜４０モル％、及び、前記ジアミノポリシロキサン及び前記エポキシ基との反応性を有する置換基を持った芳香族ジアミン以外のジアミン０〜５４．５モル％（通常、０〜３０モル％）の割合で使用されることが特に好ましい。いずれかの成分が多すぎたり、少なすぎたりしてこれらの範囲をはずれると得られるポリイミドシロキサンの有機溶媒に対する溶解性が低下したり、他の有機化合物との相溶性が悪くなったり、配線基板上に形成した絶縁膜の曲率半径が小さくなってカールを生じたり、耐屈曲性が低下したり、基材との密着性および耐熱性が低下するので好ましくない。
【００２０】
本発明におけるポリイミドシロキサンのジアミン成分を構成する下記一般式（１）で示されるジアミノポリシロキサンは、好ましくは、前記式中Ｒ_１は炭素数１〜６の２価の炭化水素基又はフェニレン基、特にプロピレン基であり、前記式中Ｒ２は独立に炭素数１〜５のアルキル基又はフェニル基であり、前記式中ｎ１は３〜５０、特に３〜２０である。ｎ１が３未満では得られる絶縁膜の耐屈曲性が悪くなるので好ましくなく、又、ｎ１が５０を超えるとテトラカルボン酸成分との反応性が低下して得られるポリイミドシロキサンの分子量が低くなったり、ポリイミドシロキサンの有機溶剤に対する溶解性が低くなったり、組成物における他の有機成分との相溶性が悪くなったり、得られる絶縁膜の耐溶剤性が低くなったりするので前記程度のものが好適である。尚、ジアミノポリシロキサンが２種以上の混合物からなる場合は、ｎ１はアミノ当量から計算される。
【化３】

（式中、Ｒ_１は２価の炭化水素基又は芳香族基を示し、Ｒ_２は独立に１価の炭素水素基又は芳香族基を示し、ｎ１は３〜５０の整数を示す。）
【００２１】
前記ジアミノポリシロキサンの具体的化合物の例としては、α，ω−ビス（２−アミノエチル)ポリジメチルシロキサン、α，ω−ビス（３−アミノプロピル)ポリジメチルシロキサン、α，ω−ビス（４−アミノフェニル)ポリジメチルシロキサン、α，ω−ビス（４−アミノ−３−メチルフェニル)ポリジメチルシロキサン、α，ω−ビス（３−アミノプロピル)ポリジフェニルシロキサン、α，ω−ビス（４−アミノブチル）ポリジメチルシロキサンなどが挙げられる。
【００２２】
本発明におけるポリイミドシロキサンのジアミン成分を構成するエポキシ基との反応性を有する置換基を持った芳香族ジアミンは、分子中にエポキシ基との反応性を有する置換基を有する芳香族ジアミンであり、好ましくは、下記一般式（２）で示されるジアミンである。
【化４】

（式中、Ｘ及びＹは、それぞれ独立に直接結合、ＣＨ_２、Ｃ（ＣＨ_３）_２、Ｃ（ＣＦ_３）_２、Ｏ、ベンゼン環、ＳＯ_２を示し、ｒ１はＣＯＯＨ又はＯＨを示し、ｎ２は１又は２であり、ｎ３、ｎ４はそれぞれ独立に０、１又は２、好ましくは０又は１であり、ｎ３及びｎ４の少なくとも一方は１又は２である。）
【００２３】
前記一般式（２）で示されるジアミン化合物としては、２，４−ジアミノフェノ−ルなどのジアミノフェノ−ル化合物類、３，３’−ジアミノ−４，４’−ジハイドロキシビフェニル、４，４’−ジアミノ−３，３’−ジハイドロキシビフェニル、４，４’−ジアミノ−２，２’−ジハイドロキシビフェニル、４，４’−ジアミノ−２，２’，５，５’−テトラハイドロキシビフェニルなどのヒドロキシビフェニル化合物類、３，３’−ジアミノ−４，４’−ジハイドロキシジフェニルメタン、４，４’−ジアミノ−３，３’−ジハイドロキシジフェニルメタン、４，４’−ジアミノ−２，２’−ジハイドロキシジフェニルメタン、２，２−ビス〔３−アミノ−４−ハイドロキシフェニル〕プロパン、２，２−ビス〔４−アミノ−３−ハイドロキシフェニル〕プロパン、２，２−ビス〔３−アミノ−４−ハイドロキシフェニル〕ヘキサフルオロプロパン、４，４’−ジアミノ−２，２’，５，５’−テトラハイドロキシジフェニルメタンなどのヒドロキシジフェニルアルカン化合物類、３，３’−ジアミノ−４，４’−ジハイドロキシジフェニルエ−テル、４，４’−ジアミノ−３，３’−ジハイドロキシジフェニルエ−テル、４，４’−ジアミノ−２，２’−ジハイドロキシジフェニルエ−テル、４，４’−ジアミノ−２，２’，５，５’−テトラハイドロキシジフェニルエ−テルなどのヒドロキシジフェニルエ−テル化合物類、３，３’−ジアミノ−４，４’−ジハイドロキシジフェニルスルホン、４，４’−ジアミノ−３，３’−ジハイドロキシジフェニルスルホン、４，４’−ジアミノ−２，２’−ジハイドロキシジフェニルスルホン、４，４’−ジアミノ−２，２’，５，５’−テトラハイドロキシジフェニルスルホンなどのヒドロキシジフェニルスルホン化合物類、２，２−ビス〔４−（４−アミノ−３−ハイドロキシフェノキシ）フェニル〕プロパンなどのビス（ハイドロキシフェニキシフェニル）アルカン化合物類、４，４’−ビス（４−アミノ−３−ハイドロキシフェノキシ）ビフェニルなどのビス（ハイドロキシフェノキシ）ビフェニル化合物類、２，２−ビス〔４−（４−アミノ−３−ハイドロキシフェノキシ）フェニル〕スルホンなどのビス（ハイドロキシフェニキシフェニル）スルホン化合物類などの、分子中に水酸基を有するジアミン化合物を好適に挙げることができる。
【００２４】
更に、前記の一般式（２）で示されるジアミン化合物としては、３，５−ジアミノ安息香酸、２，４−ジアミノ安息香酸などのベンゼンカルボン酸類、３，３’−ジアミノ−４，４’−ジカルボキシビフェニル、４，４’−ジアミノ−３，３’−ジカルボキシビフェニル、４，４’−ジアミノ−２，２’−ジカルボキシビフェニル、４，４’−ジアミノ−２，２’，５，５’−テトラカルボキシビフェニルなどのカルボキシビフェニル化合物類、３，３’−ジアミノ−４，４’−ジカルボキシジフェニルメタン、４，４’−ジアミノ−３，３’−ジカルボキシジフェニルメタン、４，４’−ジアミノ−２，２’−ジカルボキシジフェニルメタン、２，２−ビス〔３−アミノ−４−カルボキシフェニル〕プロパン、２，２−ビス〔４−アミノ−３−カルボキシフェニル〕プロパン、２，２−ビス〔３−アミノ−４−カルボキシフェニル〕ヘキサフルオロプロパン、４，４’−ジアミノ−２，２’，５，５’−テトラカルボキシビフェニルなどのカルボキシジフェニルアルカン化合物類、３，３’−ジアミノ−４，４’−ジカルボキシジフェニルエ−テル、４，４’−ジアミノ−３，３’−ジカルボキシジフェニルエ−テル、４，４’−ジアミノ−２，２’−ジカルボキシジフェニルエ−テル、４，４’−ジアミノ−２，２’，５，５’−テトラカルボキシジフェニルエ−テルなどのカルボキシジフェニルエ−テル化合物類、３，３’−ジアミノ−４，４’−ジカルボキシジフェニルスルホン、４，４’−ジアミノ−３，３’−ジカルボキシジフェニルスルホン、４，４’−ジアミノ−２，２’，５，５’−テトラカルボキシジフェニルスルホンなどのカルボキシジフェニルスルホン化合物類、２，２−ビス〔４−（４−アミノ−３−カルボキシフェノキシ）フェニル〕プロパンなどのビス（カルボキシフェノキシフェニル）アルカン化合物類、４，４’−ビス（４−アミノ−３−カルボキシフェノキシ）ビフェニルなどのビス（カルボキシフェノキシ）ビフェニル化合物類、２，２−ビス〔４−（４−アミノ−３−カルボキシフェノキシ）フェニル〕スルホンなどのビス（カルボキシフェノキシフェニル）スルホン化合物類などの、分子中にカルボキシル基を有するジアミン化合物を好適に挙げることができる。
【００２５】
本発明におけるポリイミドシロキサンのジアミン成分を構成する前記ジアミノポリシロキサン及びエポキシ基との反応性を有する置換基を持った芳香族ジアミン以外のジアミンは、特に限定されるものではないが、下記一般式（３）で示される芳香族ジアミンが好適である。
【化５】

（式中、Ｘ及びＹは、それぞれ独立に直接結合、ＣＨ_２、Ｃ（ＣＨ_３）_２、Ｃ（ＣＦ_３）_２、Ｏ、ベンゼン環、ＳＯ_２を示し、ｎ５は１又は２である。）
【００２６】
前記一般式（３）で示される芳香族ジアミンは、具体的には、１，４−ジアミノベンゼン、１，３−ジアミノベンゼン、２，４−ジアミノトルエン、１，４−ジアミノ−２，５−ジハロゲノベンゼンなどのベンゼン１個を含むジアミン類、ビス（４−アミノフェニル）エ−テル、ビス（３−アミノフェニル）エ−テル、ビス（４−アミノフェニル）スルホン、ビス（３−アミノフェニル）スルホン、ビス（４−アミノフェニル）メタン、ビス（３−アミノフェニル）メタン、ビス（４−アミノフェニル）スルフィド、ビス（３−アミノフェニル）スルフィド、２，２−ビス（４−アミノフェニル）プロパン、２，２−ビス（３−アミノフェニル）プロパン、２，２−ビス（４−アミノフェニル）ヘキサフルオロプロパン、ｏ−ジアニシジン、ｏ−トリジン、トリジンスルホン酸類などのベンゼン２個を含むジアミン類、１，４−ビス（４−アミノフェノキシ）ベンゼン、１，４−ビス（３−アミノフェノキシ）ベンゼン、１，４−ビス（４−アミノフェニル）ベンゼン、１，４−ビス（３−アミノフェニル）ベンゼン、α，α’−ビス（４−アミノフェニル）−１，４−ジイソプロピルベンゼン、α，α’−ビス（４−アミノフェニル）−１，３−ジイソプロピルベンゼンなどのベンゼン３個を含むジアミン類、２，２−ビス〔４−（４−アミノフェノキシ）フェニル〕プロパン、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、２，２−ビス〔４−（４−アミノフェノキシ）フェニル〕スルホン、４，４’−（４−アミノフェノキシ）ビフェニル、９，９−ビス（４−アミノフェニル）フルオレン、５，１０−ビス（４−アミノフェニル）アントラセンなどのベンゼン４個以上を含むジアミン類などのジアミン化合物が挙げられる。
また、ヘキサメチレンジアミン、ジアミノドデカンなど脂肪族ジアミン化合物を上記ジアミンと共に使用することができる。
【００２７】
本発明におけるポリイミドシロキサンは、特に限定するものではないが、例えば、次の方法で得ることができる。
（１）テトラカルボン酸成分とジアミン成分とを略等モル使用し、有機極性溶媒中で連続的に１５〜２５０℃で重合及びイミド化させてポリイミドシロキサンを得る方法。
（２）テトラカルボン酸成分とジアミン成分とをそれぞれ分けて、まず過剰量のテトラカルボン酸成分とアミン成分（例えばジアミノポリシロキサン）とを有機極性溶媒中１５〜２５０℃で重合及びイミド化させて平均重合度１〜１０程度の末端に酸無水物基（又は、酸、そのエステル化物）を有するイミドシロキサンオリゴマーを調製し、別にテトラカルボン酸成分と過剰量のジアミン成分とを有機極性溶媒中１５〜２５０℃で重合及びイミド化させて平均重合度１〜１０程度の末端にアミノ基を有するイミドオリゴマーを調製し、次いでこの両者を、酸成分とジアミン成分とが略等モルになるように混合して１５〜６０℃で反応させて、さらに１３０〜２５０℃に昇温して反応させて、ブロックタイプのポリイミドシロキサンを得る方法。
（３）テトラカルボン酸成分とジアミン成分とを略等モル使用し、有機極性溶媒中でまず２０〜８０℃で重合させてポリアミック酸を得た後に、そのポリアミック酸をイミド化してポリイミドシロキサンを得る方法。
【００２８】
上述の方法でポリイミドシロキサンを得る際に使用される有機極性溶媒としては、含窒素系溶媒、例えばＮ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジエチルアセトアミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジエチルホルムアミド、Ｎ−メチル−２−ピロリドン、１，３−ジメチル−２−イミダゾリジノン、Ｎ−メチルカプロラクタムなど、硫黄原子を含有する溶媒、例えばジメチルスルホキシド、ジエチルスルホキシド、ジメチルスルホン、ジエチルスルホン、ヘキサメチルスルホルアミドなどフェノール系溶媒、例えばクレゾール、フェノール、キシレノールなど、ジグライム系溶媒、例えばジエチレングリコールジメチルエーテル（ジグライム）、トリエチレングリコールジメチルエーテル（トリグライム）、テトラグライムなど、酸素原子を分子内に有する溶媒、例えばアセトン、メタノール、エタノール、エチレングリコール、ジオキサン、テトラヒドロフランなど、その他ピリジン、テトラメチル尿素などを挙げることができる。また必要に応じてベンゼン、トルエン、キシレンなどの芳香族炭化水素系溶媒やソルベントナフサ、ベンゾニトリルなど他の有機溶媒を併用してもよい。
【００２９】
本発明において、ポリイミドシロキサンは、前記（１）〜（３）などいずれの方法で得られたものを使用してもよいが、有機溶媒に少なくとも３重量％以上、好ましくは５〜６０重量％、特に５〜５０％程度の高濃度で溶解させることができるもので、２５℃の溶液粘度（Ｅ型回転粘度計）が１〜１００００ポイズ、特に１〜１００ポイズであることが好ましい。
本発明において、ポリイミドシロキサンはより高分子量のものが好ましく更にイミド化率が高いものが好ましい。分子量の目安としての対数粘度（測定濃度：０．５g ／１００ミリリットル、溶媒：Ｎ−メチル−２−ピロリドン、測定温度：３０℃）は、０．１０以上、特に０．１５〜２更に０．１５〜０．８のものが溶液組成物としての取り扱い易さ、硬化後の膜の強度、伸度などの機械的物性の点から好ましい。また、赤外吸収スペクトルから求められるイミド化率は、９０％以上特に９５％以上更に実質的に１００％のものが好ましい。
【００３０】
本発明のポリイミドシロキサン絶縁膜用組成物を構成するエポキシ化合物は、複数のエポキシ基を有する化合物であって、エポキシ当量が１００〜４０００特に１００〜３０００の液状又は固体状のエポキシ樹脂が好ましい。エポキシ化合物のエポキシ当量が４０００以上では、得られる絶縁膜用組成物が高粘度化し易く取り扱いが容易ではなくなる。
具体的には、例えば、ジャパンエポキシレジン社製 エピコート８０６、エピコート８０７、エピコート８２５、エピコート８２７、エピコート８２８、エピコート１００１、エピコート１００２、エピコート１００３、エピコート１００４、エピコート１０５５、エピコート１００４ＡＦ、エピコート１００７、エピコート１００９、エピコート１０１０、エピコート４００４Ｐ、エピコート４００７Ｐ、大日本インキ化学工業株式会社製 ＥＰＩＣＬＯＮ８４０、ＥＰＩＣＬＯＮ８５０、ＥＰＩＣＬＯＮ８６０、ＥＰＩＣＬＯＮ１０５５、ＥＰＩＣＬＯＮ３０５０、ＥＰＩＣＬＯＮ３０５０、ＥＰＩＣＬＯＮ４０５０、ＥＰＩＣＬＯＮ７０５０、ＥＰＩＣＬＯＮＡＭ−０４０−Ｐ、ＥＰＩＣＬＯＮＨＭ０９１、ＥＰＩＣＬＯＮＨＭ−１０１、ＥＰＩＣＬＯＮ８３０、ＥＰＩＣＬＯＮ８３５などのビスフェノールＡ型やビスフェノールＦ型のエポキシ樹脂、ジャパンエポキシレジン製 エピコート１５２、エピコート１５４、エピコート１５７Ｓ６５、エピコート１５７Ｓ７０、エピコート１０３２Ｓ５０、エピコート１０３２Ｈ６０、大日本インキ化学工業株式会社製 ＥＰＩＣＬＯＮＮ−６６０、ＥＰＩＣＬＯＮＮ−６６５、ＥＰＩＣＬＯＮＮ−６７０、ＥＰＩＣＬＯＮＮ−６７３、ＥＰＩＣＬＯＮＮ−６８０、ＥＰＩＣＬＯＮＮ−６９５、ＥＰＩＣＬＯＮＮ−７４０、ＥＰＩＣＬＯＮＮ−７７０、ＥＰＩＣＬＯＮＮ−７７５、ＥＰＩＣＬＯＮＮ−８６５、チバガイギ−製 ＭＴ０１６３、ナガセケムテックス株式会社製 デナコールＥＸ−３２１、デナコールＥＸ−４１１、デナコールＥＸ−６２２などの３官能以上のエポキシ樹脂、ジャパンエポキシレジン社製 エピコートＹＸ４０００、エピコートＹＬ６６４０などのビフェノール型エポキシ樹脂、ナガセケムテックス株式会社製 デナコールＥＸ−２０１、デナコールＥＸ−２１１、デナコールＥＸ−２１２、デナコールＥＸ−２５２、デナレックスＲ−４５ＥＰＴ、宇部興産株式会社製 ハイカーＥＴＢＮ１３００×４０などの２官能エポキシ樹脂などを挙げることができる。
【００３１】
本発明において、エポキシ化合物の使用量は、ポリイミドシロキサン１００重量部に対して、０．５〜３０重量部、好ましくは０．５〜２０重量部である。使用量が多すぎるとゲル化し易くなったり密着性が低下し、少なすぎると加熱処理後の硬化絶縁の耐熱性や耐薬品性悪くなるので上記範囲が好ましい。
【００３２】
本発明において、エポキシ化合物と共にヒドラジン類、イミダゾール類、３級アミン類などのエポキシ化合物の硬化反応を促進する硬化促進剤を添加することが好ましい。
特に、３級アミン類を硬化促進剤として添加すると、その絶縁膜用組成物は、基材に塗布後１２０℃程度以下の低温で加熱処理することによって硬化絶縁膜（保護膜）を容易に得ることができるので極めて好適である。本発明において好適に用いることができる３級アミン類としては、具体的には、１，８−ジアザビシクロ［５．４．０］−７−ウンデセン、Ｎ，Ｎ−ジメチルベンジルアミン、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラメチルヘキサンジアミン、トリエチレンジアミン、２−ジメチルアミノメチルフェノール、２，４，６−トリス（ジメチルアミノメチル）フェノール、ジモルホリノジエチルエーテル、１，４−ジメチルピペラジン、シクロヘキシルジメチルアミンなどを挙げることができ、特に１，８−ジアザビシクロ［５．４．０］−７−ウンデセンを好適に挙げることができる。
また、３級アミン類などの硬化促進剤は、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部に対して０．１〜１０重量部好ましくは０．１〜５重量部使用するのが好適である。使用量が１０重量部特に２０重量部を超えると耐溶剤性や電気的性質が悪くなり、少なすぎると１２０℃程度の低温での硬化に長時間を要するので上記範囲が好ましい。
【００３３】
本発明のポリイミドシロキサン絶縁膜用組成物を構成する有機溶媒としては、ポリイミドシロキサンを調製するときの反応に使用した有機溶媒をそのまま使用することができるが、好適には、含窒素系溶媒、例えばＮ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジエチルアセトアミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジエチルホルムアミド、Ｎ−メチル−２−ピロリドン、１，３−ジメチル−２−イミダゾリジノン、Ｎ−メチルカプロラクタムなど、含硫黄原子溶媒、例えばジメチルスルホキシド、ジエチルスルホキシド、ジメチルスルホン、ジエチルスルホン、ヘキサメチルスルホルアミドなど、含酸素溶媒、例えばフェノ−ル系溶媒、例えばクレゾ−ル、フェノ−ル、キシレノ−ルなど、ジグライム系溶媒例えばジエチレングリコ−ルジメチルエ−テル（ジグライム）、トリエチレングリコ−ルジメチルエ−テル（トリグライム）、テトラグライムなど、アセトン、アセトフェノン、プロピオフェノン、エチレングリコール、ジオキサン、テトラヒドロフランなどを挙げることができる。特に、Ｎ−メチル−２−ピロリドン、Ｎ,Ｎ−ジメチルスルホキシド、Ｎ,Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジエチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジエチルアセトアミド、γ−ブチロラクトン、トリエチレングリコ−ルジメチルエ−テル、ジエチレングリコ−ルジメチルエ−テルなどを好適に使用することができる。
【００３４】
更に、本発明の絶縁膜用組成物においては、微細フィラーを含有することが好ましい。微細無機フィラ−としては、どのような形態のものでもよいが、平均粒子径が０．００１〜１５μｍ、特に０．００５〜１０μｍのものが好ましい。この範囲外のものを使用すると得られる塗膜が屈曲したときに亀裂が発生したり、折り曲げ部が白化したりするので好ましくない。微細フィラ−としては、例えば微粉状シリカ、タルク、マイカ、硫酸バリウムなどの微細無機フィラ−や架橋ＮＢＲ微粒子などの微細有機フィラ−を好適に挙げることができる。
【００３５】
微細無機フィラ−の使用量は、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部に対して、合計で２０〜１５０重量部、好ましくは４０〜１２５重量部である。使用量が余り多すぎたり、余り少なすぎると塗膜の折り曲げによりクラックが発生したり、印刷性、半田耐熱性、銅箔変色性が影響を受けるので上記範囲が好適である。また、微細無機フィラー、特に微粉状シリカとタルク、マイカあるいは硫酸バリウムの少なくとも１種とを組み合わせて使用し、微紛状シリカをエポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部に対して１〜５０重量部、特に５〜４０重量部、タルク、マイカあるいは硫酸バリウムの少なくとも１種を２０〜１３０重量部使用することが、印刷性や得られる硬化絶縁膜の性能を考慮すると特に好ましい。
【００３６】
また、本発明の絶縁膜用組成物においては、有機着色顔料、無機着色顔料を所定量、例えばエポキシ基との反応性を有する基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部に対して、０〜１００重量部程度使用することができる。
また、本発明の絶縁膜用組成物においては、消泡剤を所定量、例えばエポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる有機溶剤可溶性樹脂１００重量部に対して、０．１〜１０重量部程度使用することができる。
【００３７】
本発明の絶縁膜用組成物は、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる樹脂、例えばポリイミドシロキサンと、エポキシ化合物と、微細フィラーと、有機溶媒などとを、所定量混合し、均一に撹拌・混合することによって容易に得ることができる。混合する際に有機溶媒中で混合して溶液組成物にすることができる。有機溶媒に混合させて溶液組成物にするにあたっては、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる樹脂例えばポリイミドシロキサンの重合溶液をそのままでも、又その重合溶液を適当な有機溶媒で希釈したものを使用してもよい。有機溶媒としては、前記樹脂例えばポリイミドシロキサンを得る際に使用できる有機極性溶媒を挙げることができるが、沸点１４０℃以上で２１０℃以下のものを使用することが好ましい。沸点１８０℃以上特に２００℃以上である有機溶媒（例えばメチルトリグライムなど）を使用すると、溶媒の蒸発による散逸が極めて減少するので、又その印刷インクを使用してスクリーン印刷などで印刷を支障なく好適に行うことができるので最適である。有機溶媒は、エポキシ基との反応性を有する置換基を有し且つポリシロキサン骨格を含有してなる樹脂、例えばポリイミドシロキサン１００重量部に対して６０〜２００重量程度使用する。
【００３８】
本発明の絶縁膜用組成物は、室温（２５℃）で溶液粘度が１００〜６００ポイズであることが作業性や溶液物性、その保護膜特性上などから適当である。
【００３９】
本発明の絶縁膜用組成物は、ＩＣチップなどのチップ部品を実装する電気電子部品の絶縁膜（保護膜）を形成するために用いることができる。
例えば、導電性金属箔で形成された配線パターンを有する絶縁性フィルムのパターン面に、乾燥膜の厚さが３〜６０μｍ程度となるようにスクリ−ン印刷などによって印刷して塗布した後、５０〜１００℃程度の温度で５〜６０分間程度、次いで、１００〜２１０℃程度好適には１２０〜２００℃で５〜１２０分間好適には１０〜６０分間程度の２段階で加熱し乾燥して、好適には弾性率が０．１〜２０ｋｇｆ／ｍｍ^２の絶縁膜を形成することが好ましい。
【００４０】
更に、本発明の絶縁膜用組成物は、５０〜１３０℃程度特に６０〜１２０℃の低温の加熱処理によって硬化させて、前記のような良好な性能を持った絶縁膜を容易に形成することができる。
このために、本発明の絶縁膜用組成物は、実装工程において、１６０℃程度又はそれ以上の比較的高温の加熱処理によって硬化絶縁膜を形成することもできるし、１３０℃以下好ましくは１２０℃程度以下の比較的低温の加熱処理によって硬化絶縁膜を形成することもできる。また、１３０℃以下好ましくは１２０℃程度以下の比較的低温の加熱処理によって硬化絶縁膜を形成したあとで、更に１６０℃程度又はそれ以上の比較的高温の加熱処理がおこなわれても構わない。
【００４１】
言い換えれば、本発明の絶縁膜用組成物は、例えば絶縁フィルム基材にＩＣチップなどのチップ部品を実装する際に、配線パターンを保護する絶縁膜を形成した後でスズメッキする手順で実装することもできるし、配線パターンを先にスズメッキした後でそれを保護するための絶縁膜を形成する手順で実装することも可能である。
先にスズメッキする手順は、例えば絶縁フィルム基材に実装する場合、以下のようになる。即ち、▲１▼絶縁フィルム基材表面に形成された銅箔の配線パターン表面をスズメッキする。▲２▼絶縁フィルム基材表面の所定部分に、本発明の絶縁膜用組成物を塗布または印刷し、それを１２０℃程度以下の比較的低温で加熱処理して硬化させて絶縁膜（保護膜）を形成する。▲３▼ＩＣチップなどの電子部品を金バンプなどを用いて絶縁膜を形成していない配線パターンのインナーリード部などに実装する。この時、接続部が金スズ共晶を形成するように、短時間だが４００℃程度以上の加熱処理がなされる。▲４▼次いでＩＣチップなどを封止材料などによって保護する。この時に封止材料などを硬化させるために１６０℃程度の温度で加熱処理がおこなわれる。
【００４２】
本発明の絶縁膜用組成物が前述の先にスズメッキする手順で用いられて、電子部品の絶縁膜を形成したときの一例について、概略の断面図を図１に示す。
図１において、例えば２５μｍ厚のポリイミドフィルム１の表面に、例えば１２μｍ厚の銅箔で配線パターン２が形成されており、その表面をメッキされた例えば０．５μｍ厚のスズ層３が覆っている。更にそれらの表面を、インナーリードの接続部分を除いてこの発明の絶縁用組成物からなる絶縁膜４が例えば１０μｍ厚の保護膜を形成している。接続部分では金バンプ５を用いＩＣチップ６が実装され、例えばエポキシ樹脂系の封止材料７によって保護されている。
【００４３】
また、本発明の絶縁膜用組成物は、導電性金属及び絶縁性の各種材料との密着性が良好であり、硬化物は好適な機械的強度や電気絶縁性能を有しているから、電気電子部品の保護膜としてのみならず層間絶縁膜としても好適に使用することができる。更に、本発明の絶縁膜用組成物は、低温圧着が可能でしかも耐熱性の接着剤として好適に使用することもできる。
【００４４】
【実施例】
以下、実施例及び比較例を示し、この発明を説明する。尚、この発明は以下の実施例に限定されるものではない。
【００４５】
各例において測定、評価は次の方法で行った。
（溶液粘度）
Ｅ型粘度計（東京計器社製）を用い、温度２５℃で、回転数１０ｒｐｍにて測定した。
（印刷性の評価）
スクリ−ン印刷可能で、形成された膜にピンホ−ルがなく、端部の流れ出しがない場合を○、スクリ−ン印刷が不可能かまたは膜にピンホ−ルの発生があるかあるいは端部の流れ出しがある場合を×で表示した。
【００４６】
（硬化絶縁膜の評価）
硬化絶縁膜の評価は、評価項目によって、以下のように加熱処理された硬化絶縁膜サンプルについておこなった。
すなわち、耐溶剤性、ガラス転移温度及び封止材料との密着性の評価は、実装工程において先にスズメッキが施された導体配線上に絶縁膜用組成物を塗布したときには１２０℃程度以下で加熱硬化することを考慮して、８０℃で３０分次いで１２０℃で１時間加熱処理したサンプルについておこなった。但し、封止材料との密着性の評価は、前記サンプル表面に更に封止材料を滴下して塗布し１６０℃で加熱硬化したから、合計で１２０℃及び１６０℃の２回の加熱処理がされたことになる。
それ以外の硬化絶縁膜の評価は、実装工程において封止材料を硬化するために最終的に１６０℃程度の加熱処理がおこなわれることを考慮して、８０℃で３０分次いで１６０℃で１時間加熱処理したサンプルについておこなった。
【００４７】
耐溶剤性の評価：
厚さがおよそ７５μｍになるように硬化させたシート状サンプル０．５ｇを１００ｍｌのアセトン（２５℃）に３０分間浸漬した後、アセトン可溶分の重量％で示した。
【００４８】
ＩＣ封止材料との密着性の評価：
３５μｍ厚電解銅箔光沢面上に絶縁膜用組成物を３０μｍ厚に塗布し硬化させ、この硬化膜上にＩＣチップ封止材料ＣＥＬ−Ｃ−５０２０（日立化成工業株式会社製）を約１ｍｍ厚、直径０．５ｃｍ程度の円状に滴下して塗布し１６０℃で硬化させサンプルとした。手でサンプルを折り曲げ、封止樹脂のはがれ具合を観察した。硬化絶縁膜で凝集破壊を起こした場合を○、硬化絶縁膜の凝集破壊と硬化絶縁膜／封止材料界面剥離が共存する場合を△、硬化絶縁膜膜／封止材料界面剥離の場合を×で示した。
【００４９】
電気絶縁性（体積抵抗）の測定：
この溶液組成物を用いて厚さ約７５μｍの硬化絶縁膜を形成し、その膜の電気絶縁性（体積抵抗）をＪＩＳ Ｃ−２１０３によって測定した。
引張弾性率の測定：
厚さがおよそ７５μｍになるように硬化させたシート状サンプルを、幅１ｃｍ、長さ１５ｃｍに切り出して試験に用いた。ＡＳＴＭ Ｄ８８２によって測定した。
【００５０】
スズ潜りの測定：
厚さ３５μｍの電解銅箔（三井金属鉱業社製）光沢面上に絶縁膜用組成物を３０μｍ厚に塗布し硬化させたサンプルを、無電解スズメッキ液（シプレイファーイースト社製、ＬＴ−３４）を使用し、温度７０℃で４分間スズメッキし、絶縁膜の端部においてスズが浸入してスズ潜りが起こった部分の幅（端部からの距離）を測定した。
【００５１】
以下の各例で使用したエポキシ樹脂、硬化触媒、フィラーについて説明する。
（エポキシ樹脂）
エピコート１００７：ジャパンエポキシレジン社製、エポキシ当量２０００
エピコート１００４：ジャパンエポキシレジン社製、エポキシ当量９００
ハイカーＥＴＢＮ１３００×４０：宇部興産社製、エポキシ当量２７７０、キシレン５０％溶液
エピコート１５７Ｓ７０：ジャパンエポキシレジン社製、エポキシ当量２１０
（硬化触媒）
ＤＢＵ：アルドリッチ社製、１,８‐ジアザビシクロ［５.４.０］‐７‐ウンデセン
キュアゾール２Ｅ４ＭＺ：四国化成工業社製、２−エチル−４−メチルイミダゾール
（微粉状シリカ）
アエロジル５０：日本アエロジル株式会社製、平均粒径：３０ｎｍ
アエロジル１３０：日本アエロジル株式会社製、平均粒径：１６ｎｍ
（硫酸バリウム）
硫酸バリウムＢ−３０：堺化学工業社製、平均粒径０．３μｍ
（タルク）
ミクロエースＰ−３：日本タルク社製、平均粒径５．１μｍ
（マイカ）
ＭＫ−１００：コープケミカル社製、平均粒径３〜５μｍ
【００５２】
〔ポリイミドシロキサンの製造〕
参考例１
容量５００ｍｌのガラス製フラスコに、２，３，３’，４’−ビフェニルテトラカルボン酸二無水物５８．８４ｇ（０．２モル）、溶媒のトリグライム（以下、ＴＧと略記することもある。）１２０ｇを仕込み、窒素雰囲気下、１８０℃で加熱撹拌した。α，ω−ビス（３−アミノプロピル）ポリジメチルシロキサン（アミノ当量４５５）１５４．７ｇ（０．１７モル）、ＴＧ７０ｇを加え、１８０℃で６０分間加熱撹拌した。更にこの反応溶液に４，４’−ジアミノ−３，３’−ジカルボキシフェニルメタン８．５９ｇ（０．０３モル）及びＴＧ２３．４ｇを加え、１８０℃で５時間加熱撹拌した後、濾過を行った。得られたポリイミドシロキサン反応溶液は、ポリマ−固形分濃度５０重量％、ηｉｎｈ０．１８の溶液であった。イミド化率は実質的に１００％であった。
【００５３】
参考例２
容量５００ｍｌのガラス製フラスコに、２，３，３’，４’−ビフェニルテトラカルボン酸二無水物５８．８４ｇ（０．２モル）、ＴＧ１７０ｇを仕込み、窒素雰囲気下、１８０℃で加熱撹拌した。１００℃付近まで冷却し、α，ω−ビス（３−アミノプロピル）ポリジメチルシロキサン（アミノ当量４５５）１２７．４ｇ（０．１４モル）とＴＧ５０ｇを加え、１８０℃で６０分間加熱撹拌した。更に、室温付近まで冷却後、この反応溶液に２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン１３．５２ｇ（０．０３モル）、３，５ジアミノ安息香酸４．５６ｇ（０．０３モル）及びＴＧ７９ｇを加え、１８０℃で５時間加熱撹拌した後、濾過を行った。得られたポリイミドシロキサン反応溶液は、ポリマ−固形分濃度４０重量％、ηｉｎｈ０．２０の溶液であった。イミド化率は実質的に１００％であった。
【００５４】
実施例１
ガラス製容器に、参考例１で得たポリイミドシロキサン溶液と、ポリイミドシロキサン１００重量部に対してエポキシ樹脂のエピコート１００７を１０重量部、３級アミン硬化触媒のＤＢＵを２重量部、シリコン系消泡剤を４重量部、微紛状シリカのアエロジル５０を１５．８重量部、アエロジル１３０を１.８重量部、硫酸バリウムＢ−３０を４４重量部、タルクのミクロエースＰ−３０を１１重量部、及び、マイカのＭＫ−１００を１１重量部、とを加えて攪拌し均一に混合させてポリイミドシロキサン溶液組成物（溶液粘度３６０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は５．５：１である。
【００５５】
この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物を用いて形成された硬化絶縁膜の電気絶縁性（体積抵抗）を測定したところ、５×１０^１３Ω・ｃｍであった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００５６】
実施例２
エポキシ樹脂として、エピコート１００７を５重量部とエピコート１００４を５重量部とを用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（３４０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は３．４：１である。この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００５７】
実施例３
エポキシ樹脂として、エピコート１００４を１０重量部用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（３００ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は２．５：１である。この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物を用いて形成された硬化絶縁膜の電気絶縁性（体積抵抗）を測定したところ、４×１０^１４Ω・ｃｍであった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００５８】
実施例４
エポキシ樹脂としてエピコート１００４を１０重量部用い、硬化触媒としてキュアゾール２Ｅ４ＭＺを０．３重量部用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（４８０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は２．５：１である。この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物を用いて形成された硬化絶縁膜の電気絶縁性（体積抵抗）を測定したところ、１×１０^１４Ω・ｃｍであった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００５９】
実施例５
エポキシ樹脂としてハイカーＥＴＢＮ１３００×４０を１３．８重量部用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（３００ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は１１：１である。
この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物を用いて形成された硬化絶縁膜の電気絶縁性（体積抵抗）を測定したところ、２×１０^１３Ω・ｃｍであった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００６０】
実施例６
参考例２で得たポリイミドシロキサン溶液にＴＧを添加してポリイミドシロキサン濃度を３７％に調整した溶液を用いて、ポリイミドシロキサン１００重量部に対して表１に示す種類と量を配合し、ポリイミドシロキサンの溶液組成物（４３０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は３：１である。この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物を用いて形成された硬化絶縁膜の電気絶縁性（体積抵抗）を測定したところ、１×１０^１３Ω・ｃｍであった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００６１】
実施例７
エポキシ樹脂としてエピコート１５７Ｓ７０を１重量部用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（２５０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は５．８：１である。この溶液組成物は、約５℃で２週間放置しても粘度変化は少なくスクリ−ン印刷可能であった。
この溶液組成物を用いて形成された硬化絶縁膜の電気絶縁性（体積抵抗）を測定したところ、５×１０^１３Ω・ｃｍであった。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００６２】
比較例１
エポキシ樹脂としてエピコート１５７Ｓ７０を１０重量部用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（３８０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は０．６：１である。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００６３】
比較例２
エポキシ樹脂としてエピコート１５７Ｓ７０を０．４重量部用いる以外は実施例１と同様にして、ポリイミドシロキサンの溶液組成物（２８０ポイズ）を得た。ポリイミドシロキサンのカルボキシル基とエポキシ化合物のエポキシ基の数量比は１４．１：１である。
この溶液組成物及び硬化絶縁膜についての評価結果を表２に示す。
【００６４】
【表１】

【００６５】
【表２】

【００６６】
【発明の効果】
本発明は、以上説明したとおりのものであるから、以下の効果を奏する。
すなわち、本発明は、貯蔵安定性が優れ、フレキシブル配線基板などの基材上にスクリーン印刷などの方法で良好に塗布が可能であり、それを加熱処理したときに実質的にカールが発生することがなく（非カール性）、得られた硬化絶縁膜の耐熱性、耐溶剤性、耐薬品性（耐ハンダフラックス性、耐ハンダ銅箔変色性）、耐屈曲性、及び電気特性が優れるので、電子部品などの絶縁膜（保護膜、ソルダレジスト、層間絶縁層など）を形成するための印刷インキ又は塗布用ワニスとして好適な絶縁膜用組成物であって、特に、基材に塗布後１２０℃程度以下の低温での加熱処理によっても硬化絶縁膜を得ることが可能であり、加熱処理して得られた硬化絶縁膜は基材や封止材料との密着性が特に良好であり更にスズ潜りが小さくて良好な耐スズメッキ性を有する、電子部品などの絶縁膜（保護膜、ソルダレジスト、層間絶縁層など）を形成するための印刷インキ又は塗布用ワニスとして好適な絶縁膜用組成物を提供することができる。
【図面の簡単な説明】
【図１】絶縁膜フィルム基材にＩＣなどのチップ部品などを実装した部品であって、配線パターン表面を先にスズメッキし次いでこの発明のポリイミドシロキサン絶縁膜用組成物からなる硬化絶縁膜（保護膜）を形成する手順で、絶縁フィルム基材にチップ部品を実装したときの一例の概略の断面図である。
【符号の説明】
１：ポリイミドフィルム
２：銅箔からなる配線パターン
３：メッキされたスズ層
４：絶縁用組成物からなる硬化絶縁膜（保護膜）
５：金バンプ５を用いた接合部位
６：ＩＣチップ
７：封止材料[0001]
BACKGROUND OF THE INVENTION
The present invention is a solution composition comprising an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton, and an epoxy compound, The present invention relates to a composition for an insulating film, characterized in that the quantity ratio of a reactive substituent to an epoxy group of an epoxy compound is 1: 1 to 13: 1. The solution composition of the present invention can obtain a cured insulating film by a heat treatment at a low temperature of about 120 ° C. or less after coating on a substrate. Further, the cured insulating film obtained by the heat treatment has particularly good adhesion to the base material and the sealing material, and further has a small tin dive and good tin plating resistance. The solution composition of the present invention is excellent in storage stability, and can be satisfactorily applied on a substrate such as a flexible wiring board by a method such as screen printing. (Curl resistance), heat resistance, solvent resistance, chemical resistance (solder flux resistance, solder copper foil discoloration resistance), bending resistance, and electrical properties of the cured insulating film obtained Therefore, it is used as a composition for an insulating film suitable as a printing ink or coating varnish for forming an insulating film (protective film, solder resist, interlayer insulating layer, etc.) of electronic parts.
[0002]
[Prior art]
Conventionally, the use of an epoxy resin, an aromatic polyimide resin, or the like as an insulating film (protective film) for electrical and electronic parts is known, for example, in applications such as solid elements, semiconductor integrated circuits, and flexible wiring boards. Epoxy resin has plating resistance and good adhesion to the base material, but on the other hand, it must be used in combination with a curing agent, etc., storage stability related to the curing agent, work for two-part preparation The insulation film formed by thermosetting is rigid, has low flexibility, and has poor flexibility.
[0003]
In general, since an aromatic polyimide resin is difficult to dissolve in an organic solvent, a coating film is formed using a solution of an aromatic polyimide precursor (aromatic polyamic acid), and then dried for a long time at a high temperature. It is necessary to form an aromatic polyimide insulating film by imidization by heat treatment, and there is a problem that the electrical or electronic member itself to be protected is thermally deteriorated.
[0004]
As a method for solving such a problem, a composition for an insulating film containing a resin containing a polysiloxane skeleton having high flexibility and high solubility in an organic solvent, such as polyimidesiloxane, and an epoxy resin ( For example, see Patent Documents 1 to 3). In these insulating film compositions, a segment having a substituent having reactivity with an epoxy group is suitably introduced into a resin containing a polysiloxane skeleton. However, the quantitative ratio between the substituent having reactivity with the introduced epoxy group and the epoxy group of the epoxy compound has not been studied in detail, and the composition specifically disclosed in the examples of the patent document Has a quantity ratio of about 0.1: 1 to 0.5: 1 between the substituent having reactivity with the epoxy group and the epoxy group of the epoxy compound, and is more epoxy than the substituent having reactivity with the epoxy group. The compound was formulated so that the epoxy group of the compound was large.
And since such a composition contained a polysiloxane component in large quantities, there existed a problem that adhesiveness with a certain sealing material (epoxy resin composition) was not enough.
[0005]
In addition, when forming an insulating film for electrical and electronic parts, for example, an insulating tape base material in which a wiring pattern is formed with a copper foil such as TAB tape protects the circuit except for connecting portions such as inner leads and solder ball terminals. In order to achieve this, an insulating film (protective film) is formed by applying a heat treatment after applying the insulating film composition. Next, the copper foil surface of the connection portion is tin-plated, and then an electronic component such as an IC is connected.
When this tin plating is performed, a tin dive in which tin enters the gap between the insulating film and the copper foil from the end portion of the insulating film occurs, and further, the copper foil is pierced and a hole is formed at this portion. Such a tin dive and a hole contact with a copper foil can cause breakage due to stress concentration when the copper foil is bent.
For this reason, various studies have been made in order to reduce tin dip, which is the tin plating resistance of the cured insulating film, and a solution composition in which the tin dip, which was conventionally about 250 μm, has been improved to about 100 μm is disclosed. . However, this solution composition had to have a high solution viscosity of 400 poise or more, and there was room for further improvement.
[0006]
Further, as the electrical and electronic parts are further downsized, the thickness of the copper foil used for the electrical and electronic parts becomes thinner and thinner, for example, a thin copper foil of about 12 μm is used. The occurrence of touch is a major problem in ensuring the reliability of electrical and electronic circuits. Therefore, the insulating tape base material on which the wiring pattern is formed with copper foil is first tin-plated, and then the insulating film is formed on the portion other than the connection portion. There has been proposed a method of forming an insulating film by applying a composition for heating and heat-treating it. (For example, see Patent Document 4)
Tin plating is usually about 0.5μm thick and is used to form eutectics with gold bumps to form connections, but this tin plating layer is unstable, and whiskers grow and grow at room temperature. This will cause a short circuit. For this reason, annealing is performed at a temperature of about 120 ° C. within several hours after tin plating, the lower layer of the tin plating layer is stabilized as an alloy of tin and copper, and the surface layer of the tin plating layer is eutectic with gold bumps. Hold as pure tin to form the connection.
This method does not cause the problem of the contact of the tin diving and the copper foil. However, after tin plating, when the heat treatment is performed at a temperature of about 160 ° C. to cure the insulating film composition, all tin diffuses into the copper and forms an alloy because it eutectics with gold bumps to form a connection portion. There arises a problem that a pure tin layer cannot be retained.
In order to solve such a problem, a cured insulating film can be formed by a heat treatment of about 120 ° C. or less which is an annealing temperature of the tin plating layer, and the obtained cured insulating film is used as an insulating film (protective film). There has been a demand for an improved insulating film composition capable of exhibiting the above functions.
[0007]
[Patent Document 1]
JP-A-4-36321
[Patent Document 2]
Japanese Patent Laid-Open No. 8-253676
[Patent Document 3]
JP-A-11-310754
[Patent Document 4]
JP-A-6-342969
[0008]
[Problems to be solved by the invention]
The object of the present invention is that the storage stability is excellent, it can be satisfactorily applied by a method such as screen printing on a substrate such as a flexible wiring board, and curling substantially occurs when it is heat-treated. (Non-curling), and the resulting cured insulating film has excellent heat resistance, solvent resistance, chemical resistance (solder flux resistance, solder copper foil discoloration resistance), bending resistance, and electrical properties. An insulating film composition suitable as a printing ink or coating varnish for forming an insulating film (protective film, solder resist, interlayer insulating layer, etc.) of an electronic component, particularly at 120 ° C. after being applied to a substrate It is possible to obtain a cured insulating film by a heat treatment at a low temperature of about or less, and the cured insulating film obtained by the heat treatment has particularly good adhesion to a base material and a sealing material, and further tin submerged. Small and good tin-resistant plating Having, it is to provide an insulating coating composition.
[0009]
[Means for Solving the Problems]
That is, the present invention includes (a) 100 parts by weight of an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton, and (b) 0.5 to 30 parts by weight of an epoxy compound. And (C) an insulating film composition comprising an organic solvent, wherein the quantity ratio of the substituent having reactivity with the epoxy group in (a) and the epoxy group in (b) is 1 It is related with the composition for insulating films characterized by being comprised so that it might become: 1-13: 1.
In addition, an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton includes a tetracarboxylic acid component and diaminopolysiloxanes 45 to 95 represented by the general formula (1). Mol%, aromatic diamine having a substituent having reactivity with an epoxy group 0.5 to 40 mol%, and aromatic diamine having a substituent having reactivity with the diaminopolysiloxane and the epoxy group It is related with the organic solvent soluble polyimidesiloxane obtained from the diamine component which consists of 0-54.5 mol% other than diamine.
[Chemical 2]

(Wherein R ₁ Represents a divalent hydrocarbon group or aromatic group, R ₂ Independently represents a monovalent carbon hydrogen group or an aromatic group, and n1 represents an integer of 3 to 50. )
In addition, the substituent having reactivity with an epoxy group is a carboxyl group or a hydroxyl group, a curing accelerator, an organic group having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton 0.1 to 10 parts by weight based on 100 parts by weight of the solvent-soluble resin, the curing accelerator is a tertiary amine, (e) 20 to 150 parts by weight of a fine filler, and a fine filler Is related to a combination of finely divided silica and at least one of talc, mica or barium sulfate.
Further, a cured insulating film obtained by heat-treating the insulating film composition, and after applying the insulating film composition to a substrate, the cured insulating film is heated at 50 ° C. to 210 ° C. It relates to a method of forming.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A composition comprising a resin having a reactivity with an epoxy group and containing a polysiloxane skeleton as a main component and an epoxy compound added thereto forms a cured insulating film having high flexibility by a crosslinking reaction by heat treatment. Can do. However, this cured insulating film is considered to have poor adhesion to the sealing material because the polysiloxane skeleton contained in the resin constituting the main component has low adhesion to an organic material such as an epoxy resin, In addition, the epoxy compound that is considered to improve the adhesion with the sealing material is a small component, and the cured insulating film has already formed a cross-linked structure, so that it has a sufficient role in improving the adhesion with the sealing material. It was thought that could not be fulfilled.
[0011]
The composition for an insulating film of the present invention has a substituent having reactivity with an epoxy group even though the resin constituting the main component contains a polysiloxane skeleton and the epoxy compound is a minor component. In addition, the quantity ratio of the substituent having reactivity with the epoxy group in the resin containing a polysiloxane skeleton and the epoxy group of the epoxy compound is in the range of 1: 1 to 13: 1, preferably 2: 1 to 12: 1. One feature is that the adhesiveness with the sealing material is improved.
In the present invention, a substituent having reactivity with an epoxy group and having reactivity with an epoxy group in a resin containing a polysiloxane skeleton is introduced as a substituent into the polymer chain of the resin. And does not include a reactive group at the end of the polymer chain.
[0012]
The adhesion between the cured insulating film and the sealing material will be specifically described. In the mounting process of electronic components, first, the insulating film composition is first applied to a substrate and then heat-treated to form a cured insulating film, and then a liquid sealing material is placed in contact with the cured insulating film by coating or the like. The sealing material is cured by heat treatment. Sufficient adhesion is required at the interface between the cured insulating film and the cured sealing material. Otherwise, the cured insulating film and the sealing material cannot play a role in protecting the conductors, chip parts, and the like.
The main component of the sealing material is composed of an epoxy resin and a novolac resin and contains a large amount of polar components (especially epoxy groups), so that the cured insulating film has a chemical or physical interaction with the polar component of the sealing material. If an appropriate amount is included, close chemical or physical interaction with the sealing material is possible at the interface with the sealing material, and the cured insulating film is considered to improve adhesion to the sealing material. In the present invention, a material that enables a close chemical or physical interaction between the cured insulating film and the sealing material has a substituent having a reactivity with an epoxy group remaining in the insulating cured film after curing. And a substituent having reactivity with an epoxy group in a resin containing a polysiloxane skeleton.
[0013]
The substituent having reactivity with the epoxy group and having reactivity with the epoxy group in the resin containing the polysiloxane skeleton is the same as the epoxy group of the epoxy compound in the curing process of the insulating cured film. Thus, the number of substituents having reactivity with the epoxy group remaining in the insulating cured film varies depending on the amount of the epoxy compound in the composition. As the compounding amount of the epoxy compound increases, the substituent having reactivity with the epoxy group remaining in the insulating cured film decreases, and the substituent having reactivity with the remaining epoxy group is also formed by a large amount of the epoxy compound. Since it is incorporated into a dense cross-linked structure and free movement is suppressed, it cannot perform a close chemical or physical interaction with the sealing material at the interface with the sealing material. Adhesion decreases. On the other hand, when the compounding amount of the epoxy compound is too small, a crosslinked structure having a required density cannot be obtained, and the solvent resistance and heat resistance of the cured insulating film are lowered.
[0014]
The present invention comprises (a) 100 parts by weight of an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton, (b) 0.5 to 30 parts by weight of an epoxy compound, And (C) a composition for an insulating film containing an organic solvent, having a substituent having reactivity with an epoxy group and having reactivity with an epoxy group in a resin containing a polysiloxane skeleton. When the quantity ratio of the epoxy group of the group to the epoxy compound is configured to be 1: 1 to 13: 1, particularly 2: 1 to 12: 1, the obtained cured insulating film has excellent adhesion to the sealing material and is resistant. It has been made by finding out that the solvent property and heat resistance are satisfactory. When the substituent having reactivity with the epoxy group is less than 1 in terms of the quantity ratio compared to the epoxy group of the epoxy compound, the adhesion to the sealing material is lowered, and when it exceeds 13, the solvent resistance and heat resistance are reduced. This is not preferable because it is not sufficient.
[0015]
In the present invention, an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton is an aromatic dicarboxylic acid as an end group of a polymer chain or a substituent of a polymer chain. Substantially no curing reaction occurs at normal temperatures with epoxy groups such as acid anhydride groups, aromatic dicarboxylic acid half ester groups, carboxylic acid groups, hydroxyl groups, and amide groups. For example, curing reactions at relatively high temperatures of 80 ° C or higher. A resin in which the polymer chain contains a polysiloxane skeleton, preferably from the viewpoint of heat resistance and chemical resistance, the polymer chain is a flexible polysiloxane skeleton and a benzene ring. It is a resin containing a rigid segment such as an imide ring.
In the present invention, the organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton is not limited, but polyimide siloxane as shown below is particularly suitable. is there. Hereinafter, the present invention will be described by taking polyimidesiloxane as an example.
[0016]
In the present invention, a polyimidesiloxane suitable as an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton is preferably a tetracarboxylic acid component and diaminopolysiloxane 45- 95 mol%, preferably 60 to 95 mol%, 0.5 to 40 mol% of an aromatic diamine having a substituent having reactivity with an epoxy group, and reactivity with the diaminopolysiloxane and the epoxy group. A diamine component consisting of 0 to 54.5 mol% (usually 0 to 30 mol%) of a diamine other than an aromatic diamine having a substituent having a tetracarboxylic acid with respect to 1 mol of the diamine component. It can be obtained by reacting in an organic solvent using the acid component in a proportion of about 1.0 to 1.2 mol. If the amount of the tetracarboxylic acid component is too much, the printing characteristics of the resulting composition for a polyimidesiloxane insulating film deteriorate, which is not preferable.
[0017]
Specific examples of the tetracarboxylic acid component of polyimidesiloxane include 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-diphenylethertetracarboxylic acid, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 2,2-bis ( 3,4-benzenedicarboxylic acid) hexafluoropropane, pyromellitic acid, 1,4-bis (3,4-benzenedicarboxylic acid) benzene, 2,2-bis [4- (3,4-phenoxydicarboxylic acid) phenyl Propane, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,2,4,5-naphthalenetetracarboxylic acid, 1,4,5,8 -Aromatic tetracarboxylic acids such as naphthalenetetracarboxylic acid, 1,1-bis (2,3-dicarboxyphenyl) ethane, or esterified products of their acid dianhydrides or lower alcohols, and cyclopentane An alicyclic tetracarboxylic acid such as tetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3-methyl-4-cyclohexene-1,2,4,5-tetracarboxylic acid, or Preferable examples include acid dianhydrides and esterified products of lower alcohols. Among these, in particular, 2,3,3 ′, 4′-biphenyltetracarboxylic acid and 3,3 ′, 4,4′-diphenylethertetracarboxylic acid, or their acid dianhydrides, An esterified product of a lower alcohol is preferable because it has excellent solubility in an organic solvent when polyimide siloxane is used.
Moreover, in this invention, it is preferable to contain the aromatic tetracarboxylic acid component which was illustrated above in 80 mol% or more, especially 85%-100% in the tetracarboxylic acid component of polyimidesiloxane.
[0018]
As the tetracarboxylic acid component of the polyimidesiloxane in the present invention, it is preferable to use a tetracarboxylic dianhydride that can be easily reacted with a diamine.
Further, when the amount of tetracarboxylic dianhydride used is 1.05 mol or more with respect to diamine and an unreacted anhydrous ring remains, it may be left as it is, but it may be ring-opened half-esterified with an esterifying agent. May be. The amount of alcohol used as the esterifying agent is preferably 1.1 to 20 times equivalent, more preferably 1.5 to 5 times equivalent of the excess tetracarboxylic dianhydride. If the proportion of alcohols is small, unreacted anhydrous rings remain, resulting in poor storage stability in the composition, and excessive alcohols may precipitate insolubles or become poor solvents to lower the solid content concentration. This is not preferable because the formation of a coating film by printing becomes difficult.
When an esterifying agent is used, the reaction solution may be used as it is, but excess alcohols can be used by heating or distillation under reduced pressure.
[0019]
In the present invention, the diamine component of polyimidesiloxane is 45 to 95 mol%, preferably 60 to 95 mol% of a diaminopolysiloxane represented by the following general formula (1), and a fragrance having a substituent having reactivity with an epoxy group. 0.5 to 40 mol% of an aromatic diamine and 0 to 54.5 mol% of a diamine other than an aromatic diamine having a substituent having reactivity with the diaminopolysiloxane and the epoxy group (usually 0 to 30) It is particularly preferred to be used in a proportion of mol%). If either component is too much or too little, the resulting polyimide siloxane may be less soluble in organic solvents, may be less compatible with other organic compounds, Since the curvature radius of the insulating film formed above becomes small, curling occurs, bending resistance is lowered, and adhesion to a substrate and heat resistance are not preferred.
[0020]
The diaminopolysiloxane represented by the following general formula (1) constituting the diamine component of the polyimidesiloxane in the present invention is preferably R in the above formula. ₁ Is a divalent hydrocarbon group having 1 to 6 carbon atoms or a phenylene group, particularly a propylene group, wherein R2 is independently an alkyl group or phenyl group having 1 to 5 carbon atoms, wherein n1 is 3 ~ 50, especially 3-20. If n1 is less than 3, it is not preferable because the bending resistance of the obtained insulating film is deteriorated, and if n1 exceeds 50, the reactivity with the tetracarboxylic acid component is lowered and the molecular weight of the resulting polyimidesiloxane is lowered. The above-mentioned ones are preferable because the solubility of polyimide siloxane in an organic solvent is low, the compatibility with other organic components in the composition is poor, and the solvent resistance of the resulting insulating film is low. It is. In addition, when diaminopolysiloxane consists of 2 or more types of mixtures, n1 is calculated from an amino equivalent.
[Chemical 3]

(Wherein R ₁ Represents a divalent hydrocarbon group or aromatic group, R ₂ Independently represents a monovalent carbon hydrogen group or an aromatic group, and n1 represents an integer of 3 to 50. )
[0021]
Specific examples of the diaminopolysiloxane include α, ω-bis (2-aminoethyl) polydimethylsiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis (4 -Aminophenyl) polydimethylsiloxane, α, ω-bis (4-amino-3-methylphenyl) polydimethylsiloxane, α, ω-bis (3-aminopropyl) polydiphenylsiloxane, α, ω-bis (4- Aminobutyl) polydimethylsiloxane and the like.
[0022]
The aromatic diamine having a substituent having reactivity with the epoxy group constituting the diamine component of the polyimidesiloxane in the present invention is an aromatic diamine having a substituent having reactivity with the epoxy group in the molecule, Preferably, it is a diamine represented by the following general formula (2).
[Formula 4]

(Wherein X and Y are each independently a direct bond, CH ₂ , C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , O, benzene ring, SO ₂ , R1 represents COOH or OH, n2 is 1 or 2, n3 and n4 are each independently 0, 1 or 2, preferably 0 or 1, and at least one of n3 and n4 is 1 or 2 It is. )
[0023]
Examples of the diamine compound represented by the general formula (2) include diaminophenol compounds such as 2,4-diaminophenol, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4 '-Diamino-3,3'-dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, 4,4'-diamino-2,2', 5,5'-tetrahydroxybiphenyl, etc. Hydroxybiphenyl compounds, 3,3′-diamino-4,4′-dihydroxydiphenylmethane, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, 4,4′-diamino-2,2′- Dihydroxydiphenylmethane, 2,2-bis [3-amino-4-hydroxyphenyl] propane, 2,2-bis [4-amino-3-hydroxyphenyl] pro Hydroxydiphenylalkane compounds such as 2,2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane, 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylmethane, 3 , 3'-diamino-4,4'-dihydroxydiphenyl ether, 4,4'-diamino-3,3'-dihydroxydiphenyl ether, 4,4'-diamino-2,2'-di Hydroxydiphenyl ether compounds such as hydroxydiphenyl ether, 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenyl ether, 3,3′-diamino-4,4 ′ -Dihydroxydiphenylsulfone, 4,4'-diamino-3,3'-dihydroxydiphenylsulfone, 4,4'-diamino-2,2'-dihydroxydiphe Hydrosulfone, hydroxydiphenylsulfone compounds such as 4,4′-diamino-2,2 ′, 5,5′-tetrahydroxydiphenylsulfone, 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl Bis (hydroxyphenoxyphenyl) alkane compounds such as propane, bis (hydroxyphenoxy) biphenyl compounds such as 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl, 2,2-bis [4 Preferred examples include diamine compounds having a hydroxyl group in the molecule, such as bis (hydroxyphenoxyphenyl) sulfone compounds such as-(4-amino-3-hydroxyphenoxy) phenyl] sulfone.
[0024]
Furthermore, examples of the diamine compound represented by the general formula (2) include benzenecarboxylic acids such as 3,5-diaminobenzoic acid and 2,4-diaminobenzoic acid, 3,3′-diamino-4,4′- Dicarboxybiphenyl, 4,4′-diamino-3,3′-dicarboxybiphenyl, 4,4′-diamino-2,2′-dicarboxybiphenyl, 4,4′-diamino-2,2 ′, 5 Carboxybiphenyl compounds such as 5′-tetracarboxybiphenyl, 3,3′-diamino-4,4′-dicarboxydiphenylmethane, 4,4′-diamino-3,3′-dicarboxydiphenylmethane, 4,4′- Diamino-2,2′-dicarboxydiphenylmethane, 2,2-bis [3-amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxypheny] Carboxydiphenylalkane compounds such as propane, 2,2-bis [3-amino-4-carboxyphenyl] hexafluoropropane, 4,4′-diamino-2,2 ′, 5,5′-tetracarboxybiphenyl, 3,3′-diamino-4,4′-dicarboxydiphenyl ether, 4,4′-diamino-3,3′-dicarboxydiphenyl ether, 4,4′-diamino-2,2′- Carboxydiphenyl ether compounds such as dicarboxydiphenyl ether, 4,4′-diamino-2,2 ′, 5,5′-tetracarboxydiphenyl ether, 3,3′-diamino-4,4 '-Dicarboxydiphenylsulfone, 4,4'-diamino-3,3'-dicarboxydiphenylsulfone, 4,4'-diamino-2,2', 5,5'-tetracarboxydiphenyl Carboxydiphenylsulfone compounds such as luphone, bis (carboxyphenoxyphenyl) alkane compounds such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] propane, 4,4′-bis (4 Bis (carboxyphenoxy) biphenyl compounds such as -amino-3-carboxyphenoxy) biphenyl, bis (carboxyphenoxyphenyl) sulfone such as 2,2-bis [4- (4-amino-3-carboxyphenoxy) phenyl] sulfone Preferable examples include diamine compounds having a carboxyl group in the molecule, such as compounds.
[0025]
The diamine other than the aromatic diamine having a substituent having reactivity with the diaminopolysiloxane and the epoxy group constituting the diamine component of the polyimidesiloxane in the present invention is not particularly limited, but the following general formula ( Aromatic diamines represented by 3) are preferred.
[Chemical formula 5]

(Wherein X and Y are each independently a direct bond, CH ₂ , C (CH ₃ ) ₂ , C (CF ₃ ) ₂ , O, benzene ring, SO ₂ N5 is 1 or 2. )
[0026]
Specific examples of the aromatic diamine represented by the general formula (3) include 1,4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 1,4-diamino-2,5- Diamines containing one benzene such as dihalogenobenzene, bis (4-aminophenyl) ether, bis (3-aminophenyl) ether, bis (4-aminophenyl) sulfone, bis (3-aminophenyl) ) Sulfone, bis (4-aminophenyl) methane, bis (3-aminophenyl) methane, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfide, 2,2-bis (4-aminophenyl) Propane, 2,2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, o-dianisidine, Diamines containing two benzenes such as tolidine and tolidinesulfonic acids, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4- Aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene, α, α′-bis (4-aminophenyl) Diamines containing three benzenes such as 1,3-diisopropylbenzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl ] Hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 4,4 '-(4-aminophenoxy) biphenyl, 9, Examples thereof include diamine compounds such as diamines containing 4 or more benzenes such as 9-bis (4-aminophenyl) fluorene and 5,10-bis (4-aminophenyl) anthracene.
In addition, aliphatic diamine compounds such as hexamethylene diamine and diaminododecane can be used together with the diamine.
[0027]
Although the polyimidesiloxane in this invention is not specifically limited, For example, it can obtain by the following method.
(1) A method of obtaining polyimidesiloxane by polymerizing and imidizing continuously at 15 to 250 ° C. in an organic polar solvent, using approximately equimolar amounts of a tetracarboxylic acid component and a diamine component.
(2) A tetracarboxylic acid component and a diamine component are separated from each other. First, an excess amount of a tetracarboxylic acid component and an amine component (for example, diaminopolysiloxane) are polymerized and imidized at 15 to 250 ° C. in an organic polar solvent. An imidosiloxane oligomer having an acid anhydride group (or acid, esterified product thereof) at the terminal having an average degree of polymerization of about 1 to 10 is prepared, and a tetracarboxylic acid component and an excess amount of a diamine component are separately added in an organic polar solvent 15 Polymerize and imidize at ˜250 ° C. to prepare an imide oligomer having an amino group at an average degree of polymerization of about 1 to 10, and then mix the two so that the acid component and the diamine component are approximately equimolar. And then reacting at 15 to 60 ° C. and further raising the temperature to 130 to 250 ° C. to obtain a block type polyimidesiloxane.
(3) Using a substantially equimolar amount of a tetracarboxylic acid component and a diamine component, first polymerizing at 20 to 80 ° C. in an organic polar solvent to obtain a polyamic acid, then imidizing the polyamic acid to obtain a polyimidesiloxane. Method.
[0028]
Examples of the organic polar solvent used in obtaining the polyimidesiloxane by the above-described method include nitrogen-containing solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N- Solvents containing sulfur atoms such as diethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, hexa Phenol solvents such as methylsulfolamide, such as cresol, phenol, xylenol, diglyme solvents such as diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), tetraglyme , The solvent having an oxygen atom in the molecule, such as acetone, methanol, ethanol, ethylene glycol, dioxane, tetrahydrofuran, and other pyridine, and the like tetramethylurea. Moreover, you may use together other organic solvents, such as aromatic hydrocarbon type solvents, such as benzene, toluene, and xylene, solvent naphtha, and benzonitrile, as needed.
[0029]
In the present invention, the polyimide siloxane may be obtained by any method such as the above (1) to (3), but at least 3% by weight, preferably 5 to 60% by weight in the organic solvent, In particular, it can be dissolved at a high concentration of about 5 to 50%, and the solution viscosity at 25 ° C. (E-type rotational viscometer) is preferably 1 to 10,000 poise, particularly 1 to 100 poise.
In the present invention, the polyimide siloxane preferably has a higher molecular weight and more preferably has a higher imidization rate. The logarithmic viscosity (measurement concentration: 0.5 g / 100 ml, solvent: N-methyl-2-pyrrolidone, measurement temperature: 30 ° C.) as a measure of the molecular weight is 0.10 or more, particularly 0.15 to 2, and more preferably 0.00. The thing of 15-0.8 is preferable from the point of mechanical physical properties, such as the ease of handling as a solution composition, the intensity | strength of the film | membrane after hardening, and elongation. Further, the imidation ratio obtained from the infrared absorption spectrum is preferably 90% or more, particularly 95% or more, and substantially 100%.
[0030]
The epoxy compound constituting the composition for polyimide siloxane insulating film of the present invention is a compound having a plurality of epoxy groups, and is preferably a liquid or solid epoxy resin having an epoxy equivalent of 100 to 4000, particularly 100 to 3000. When the epoxy equivalent of the epoxy compound is 4000 or more, the resulting composition for an insulating film is likely to have a high viscosity and is not easy to handle.
Specifically, for example, Epicoat 806, Epicoat 807, Epicoat 825, Epicoat 827, Epicoat 828, Epicoat 1001, Epicoat 1002, Epicoat 1003, Epicoat 1004, Epicoat 1055, Epicoat 1004AF, Epicoat 1007, Epicoat 1009 manufactured by Japan Epoxy Resin Co., Ltd. , Epicoat 1010, Epicoat 4004P, Epicoat 4007P, manufactured by Dainippon Ink & Chemicals, Inc. Epiclon 830, EPICLON 835 and other bisphenol A type and bisphenol F type epoxy resins, Japan Epoxy Resin Epicoat 152, Epicoat 154, Epicoat 157S65, Epicoat 157S70, Epicoat 1032S50, Epicoat 1032H60, Dainippon Ink & Chemicals, Inc. EPICLONN-660, EPICLONN-665, EPICLONN-670, EPICLONN-673, EPICLONN-680, EPICLONN-695, EPICLONN-740, EPICLONN-770, EPICLONN-775, EPICLONN-865, Ciba Geiger Co., Ltd. 321, Denacoal EX-411, Denaco Trifunctional or higher functional epoxy resin such as Le EX-622, Biphenol type epoxy resin such as Epicoat YX4000 and Epicoat YL6640 manufactured by Japan Epoxy Resin, Denacol EX-201, Denacol EX-212, Denacol EX-212 manufactured by Nagase ChemteX Corporation , Denacol EX-252, Denalex R-45EPT, bifunctional epoxy resin such as Hiker ETBN 1300 × 40 manufactured by Ube Industries, Ltd., and the like.
[0031]
In this invention, the usage-amount of an epoxy compound is 0.5-30 weight part with respect to 100 weight part of polyimide siloxane, Preferably it is 0.5-20 weight part. If the amount used is too large, gelation tends to occur or the adhesiveness is lowered, and if it is too small, the heat resistance and chemical resistance of the cured insulation after heat treatment deteriorate, so the above range is preferred.
[0032]
In this invention, it is preferable to add the hardening accelerator which accelerates | stimulates hardening reaction of epoxy compounds, such as hydrazines, imidazoles, and tertiary amines, with an epoxy compound.
In particular, when a tertiary amine is added as a curing accelerator, the insulating film composition easily obtains a cured insulating film (protective film) by heat treatment at a low temperature of about 120 ° C. or less after being applied to the substrate. This is very suitable. Specific examples of tertiary amines that can be suitably used in the present invention include 1,8-diazabicyclo [5.4.0] -7-undecene, N, N-dimethylbenzylamine, N, N, N ′, N′-tetramethylhexanediamine, triethylenediamine, 2-dimethylaminomethylphenol, 2,4,6-tris (dimethylaminomethyl) phenol, dimorpholinodiethyl ether, 1,4-dimethylpiperazine, cyclohexyldimethylamine In particular, 1,8-diazabicyclo [5.4.0] -7-undecene can be preferably mentioned.
Further, the curing accelerator such as a tertiary amine is 0.1 to 10 parts per 100 parts by weight of an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton. It is preferred to use 0.1 to 5 parts by weight, preferably 0.1 to 5 parts by weight. When the amount used exceeds 10 parts by weight, particularly 20 parts by weight, the solvent resistance and electrical properties are deteriorated. When the amount is too small, the curing at a low temperature of about 120 ° C. takes a long time, so the above range is preferable.
[0033]
As the organic solvent constituting the composition for polyimide siloxane insulating film of the present invention, the organic solvent used in the reaction when preparing polyimide siloxane can be used as it is, but preferably a nitrogen-containing solvent, for example, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N- Sulfur-containing atomic solvents such as methyl caprolactam, such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, diethyl sulfone, hexamethylsulfuramide, etc. Oxygen-containing solvents such as phenolic solvents such as cresol, phenol, xyleno -Glyme solvents such as diethylene glycol Ethyleneglycol dimethyl - ether (diglyme), triethylene glycol - ethyleneglycol dimethyl - ether (triglyme), and tetraglyme, acetone, acetophenone, propiophenone, ethylene glycol, dioxane, tetrahydrofuran and the like. In particular, N-methyl-2-pyrrolidone, N, N-dimethylsulfoxide, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, γ-butyrolactone, tri Ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and the like can be preferably used.
[0034]
Furthermore, the insulating film composition of the present invention preferably contains a fine filler. The fine inorganic filler may be of any form, but preferably has an average particle size of 0.001 to 15 μm, particularly 0.005 to 10 μm. Use of a material outside this range is not preferable because a crack is generated when the resulting coating film is bent or the bent portion is whitened. Preferable examples of the fine filler include fine inorganic fillers such as fine powdered silica, talc, mica, and barium sulfate, and fine organic fillers such as crosslinked NBR fine particles.
[0035]
The amount of the fine inorganic filler used is 20 to 150 parts by weight in total with respect to 100 parts by weight of the organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton. Preferably it is 40-125 weight part. If the amount used is too large or too small, cracks may occur due to bending of the coating film, and printability, solder heat resistance, and copper foil discoloration will be affected, so the above range is preferred. Further, a fine inorganic filler, particularly fine powdery silica and at least one of talc, mica or barium sulfate are used in combination, and the finely divided silica has a substituent having reactivity with an epoxy group and has a polysiloxane skeleton. 1 to 50 parts by weight, particularly 5 to 40 parts by weight, and 20 to 130 parts by weight of at least one of talc, mica or barium sulfate is used per 100 parts by weight of the organic solvent-soluble resin containing In view of the properties and the performance of the obtained cured insulating film, it is particularly preferable.
[0036]
In addition, in the composition for an insulating film of the present invention, an organic solvent-soluble resin having a predetermined amount of an organic coloring pigment and an inorganic coloring pigment, for example, a group having reactivity with an epoxy group and containing a polysiloxane skeleton About 0 to 100 parts by weight can be used with respect to 100 parts by weight.
In the composition for an insulating film of the present invention, a predetermined amount of an antifoaming agent, for example, 100 parts by weight of an organic solvent-soluble resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton In contrast, about 0.1 to 10 parts by weight can be used.
[0037]
The composition for an insulating film of the present invention is a resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton, such as polyimide siloxane, an epoxy compound, a fine filler, an organic solvent, etc. Can be easily obtained by mixing a predetermined amount and stirring and mixing uniformly. When mixing, it can be mixed in an organic solvent to form a solution composition. In mixing with an organic solvent to form a solution composition, a polymerization solution of a resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton, such as polyimide siloxane, can be used as it is, or the polymerization can be performed. A solution obtained by diluting with a suitable organic solvent may be used. Examples of the organic solvent include an organic polar solvent that can be used when obtaining the above-mentioned resin, for example, polyimide siloxane. It is preferable to use an organic solvent having a boiling point of 140 ° C. or higher and 210 ° C. or lower. When an organic solvent having a boiling point of 180 ° C. or higher, particularly 200 ° C. or higher is used, dissipation due to evaporation of the solvent is remarkably reduced, and printing is not hindered by screen printing using the printing ink. Since it can be suitably performed, it is optimal. The organic solvent is used in an amount of about 60 to 200 weights per 100 parts by weight of a resin having a substituent having reactivity with an epoxy group and containing a polysiloxane skeleton, for example, polyimidesiloxane.
[0038]
The composition for an insulating film of the present invention suitably has a solution viscosity of 100 to 600 poise at room temperature (25 ° C.) in view of workability, solution physical properties, and protective film characteristics.
[0039]
The composition for an insulating film of the present invention can be used for forming an insulating film (protective film) of an electric / electronic component on which a chip component such as an IC chip is mounted.
For example, after applying and printing on the pattern surface of an insulating film having a wiring pattern formed of conductive metal foil by screen printing or the like so that the thickness of the dry film is about 3 to 60 μm, 50 About 5 to 60 minutes at a temperature of about 100 ° C., then about 100 to 210 ° C., preferably 120 to 200 ° C. for 5 to 120 minutes, preferably about 10 to 60 minutes for heating and drying, Preferably, the elastic modulus is 0.1 to 20 kgf / mm ² It is preferable to form an insulating film.
[0040]
Furthermore, the insulating film composition of the present invention is cured by a low-temperature heat treatment of about 50 to 130 ° C., particularly 60 to 120 ° C., to easily form an insulating film having the above-mentioned good performance. Can do.
For this reason, the composition for an insulating film of the present invention can form a cured insulating film by a relatively high temperature heat treatment of about 160 ° C. or higher in the mounting process, or 130 ° C. or less, preferably 120 ° C. A cured insulating film can also be formed by a heat treatment at a relatively low temperature of about or less. Further, after the cured insulating film is formed by heat treatment at a relatively low temperature of 130 ° C. or less, preferably about 120 ° C. or less, a heat treatment at a relatively high temperature of about 160 ° C. or more may be performed.
[0041]
In other words, the insulating film composition of the present invention is mounted by a tin plating procedure after forming an insulating film that protects a wiring pattern, for example, when mounting a chip component such as an IC chip on an insulating film substrate. It is also possible to mount the wiring pattern in accordance with a procedure of forming an insulating film for protecting the wiring pattern after first tin plating.
The procedure of tin plating first is as follows, for example, when mounting on an insulating film substrate. (1) Tin plating is performed on the surface of the wiring pattern of the copper foil formed on the surface of the insulating film substrate. (2) The insulating film composition of the present invention is applied or printed on a predetermined portion of the surface of the insulating film substrate, and is heated and cured at a relatively low temperature of about 120 ° C. or lower to cure the insulating film (protective film) ). (3) An electronic component such as an IC chip is mounted on an inner lead portion of a wiring pattern in which an insulating film is not formed using a gold bump or the like. At this time, heat treatment is performed at a temperature of about 400 ° C. or more for a short time so that the connection portion forms a gold-tin eutectic. (4) Next, the IC chip or the like is protected with a sealing material or the like. At this time, heat treatment is performed at a temperature of about 160 ° C. in order to cure the sealing material and the like.
[0042]
FIG. 1 shows a schematic cross-sectional view of an example when the insulating film composition of the present invention is used in the above-described procedure of tin plating to form an insulating film of an electronic component.
In FIG. 1, for example, a wiring pattern 2 is formed on a surface of a polyimide film 1 having a thickness of 25 μm, for example, with a copper foil having a thickness of 12 μm, and a tin layer 3 having a thickness of 0.5 μm, for example, is coated on the surface. . Further, the insulating film 4 made of the insulating composition of the present invention forms a protective film having a thickness of, for example, 10 μm on the surface except for the connecting portion of the inner lead. The IC chip 6 is mounted using gold bumps 5 at the connection portion, and is protected by, for example, an epoxy resin-based sealing material 7.
[0043]
In addition, the composition for an insulating film of the present invention has good adhesion to conductive metals and various insulating materials, and the cured product has suitable mechanical strength and electrical insulation performance. It can be suitably used not only as a protective film for electronic parts but also as an interlayer insulating film. Furthermore, the composition for an insulating film of the present invention can be used at low temperature and can be suitably used as a heat-resistant adhesive.
[0044]
【Example】
Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. In addition, this invention is not limited to a following example.
[0045]
In each example, measurement and evaluation were performed by the following methods.
(Solution viscosity)
Using an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.), measurement was performed at a temperature of 25 ° C. and a rotation speed of 10 rpm.
(Evaluation of printability)
○ when screen printing is possible, the film formed does not have pinholes, and there is no flow out of the edges, screen printing is impossible, or there is pinholes on the film or edges The case where there is a flow of is indicated by ×.
[0046]
(Evaluation of cured insulating film)
Evaluation of the cured insulating film was performed on the cured insulating film sample that was heat-treated as follows depending on the evaluation item.
That is, the solvent resistance, the glass transition temperature, and the adhesion to the sealing material are evaluated by heating at about 120 ° C. or less when the insulating film composition is applied onto the conductor wiring that has been previously plated with tin in the mounting process. In consideration of curing, it was performed on a sample heat-treated at 80 ° C. for 30 minutes and then at 120 ° C. for 1 hour. However, the evaluation of the adhesion with the sealing material was performed by dropping the sealing material further onto the sample surface and applying and curing at 160 ° C., so that the heat treatment was performed twice at 120 ° C. and 160 ° C. in total. That's right.
The evaluation of the other cured insulating film is performed at 80 ° C. for 30 minutes and then at 160 ° C. for 1 hour, considering that a final heat treatment is performed at about 160 ° C. in order to cure the sealing material in the mounting process. It carried out about the sample which heat-processed.
[0047]
Evaluation of solvent resistance:
After 0.5 g of a sheet-like sample cured so as to have a thickness of approximately 75 μm was immersed in 100 ml of acetone (25 ° C.) for 30 minutes, it was expressed as weight% of acetone-soluble matter.
[0048]
Evaluation of adhesion with IC sealing material:
An insulating film composition is applied to a glossy surface of 35 μm thick electrolytic copper foil to a thickness of 30 μm and cured, and an IC chip sealing material CEL-C-5020 (manufactured by Hitachi Chemical Co., Ltd.) is about 1 mm thick on the cured film. The sample was dropped into a circle having a diameter of about 0.5 cm, applied, and cured at 160 ° C. to obtain a sample. The sample was bent by hand, and the degree of peeling of the sealing resin was observed. ○ when cohesive failure occurs in the cured insulating film, Δ when cohesive failure of the cured insulating film and cured insulation film / sealing material interface peeling coexist, and × when the case of cured insulating film / sealing material interface peeling It showed in.
[0049]
Measurement of electrical insulation (volume resistance):
A cured insulating film having a thickness of about 75 μm was formed using this solution composition, and the electric insulation (volume resistance) of the film was measured according to JIS C-2103.
Measurement of tensile modulus:
A sheet-like sample cured so as to have a thickness of approximately 75 μm was cut into a width of 1 cm and a length of 15 cm and used for the test. Measured by ASTM D882.
[0050]
Tin diving measurement:
An electroless tin plating solution (manufactured by Shipley Far East Co., Ltd., LT-34) was prepared by applying an insulating film composition to a thickness of 30 μm on a glossy surface of an electrolytic copper foil having a thickness of 35 μm (manufactured by Mitsui Mining & Mining Co., Ltd.) Was used, and tin plating was performed at a temperature of 70 ° C. for 4 minutes, and the width (distance from the end portion) of the portion where tin entered into the end portion of the insulating film and tin sublimation occurred was measured.
[0051]
The epoxy resin, curing catalyst, and filler used in the following examples will be described.
(Epoxy resin)
Epicoat 1007: Japan Epoxy Resin, Epoxy equivalent 2000
Epicoat 1004: Epoxy equivalent 900 manufactured by Japan Epoxy Resin Co., Ltd.
Hiker ETBN 1300 × 40: Ube Industries, epoxy equivalent 2770, xylene 50% solution
Epicoat 157S70: Epoxy equivalent 210 manufactured by Japan Epoxy Resin Co., Ltd.
(Curing catalyst)
DBU: Aldrich 1,8-diazabicyclo [5.4.0] -7-undecene
Curezole 2E4MZ: 2-ethyl-4-methylimidazole, manufactured by Shikoku Kasei Kogyo Co., Ltd.
(Fine powder silica)
Aerosil 50: manufactured by Nippon Aerosil Co., Ltd., average particle size: 30 nm
Aerosil 130: manufactured by Nippon Aerosil Co., Ltd., average particle size: 16 nm
(Barium sulfate)
Barium sulfate B-30: manufactured by Sakai Chemical Industry Co., Ltd., average particle size: 0.3 μm
(talc)
Microace P-3: manufactured by Nippon Talc Co., Ltd., average particle size 5.1 μm
(Mica)
MK-100: manufactured by Coop Chemical Co., Ltd., average particle diameter of 3 to 5 μm
[0052]
[Production of polyimide siloxane]
Reference example 1
In a glass flask having a capacity of 500 ml, 58.84 g (0.2 mol) of 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride and a solvent triglyme (hereinafter sometimes abbreviated as TG). 120 g was charged and heated and stirred at 180 ° C. in a nitrogen atmosphere. α, ω-bis (3-aminopropyl) polydimethylsiloxane (amino equivalent 455) 154.7 g (0.17 mol) and TG 70 g were added, and the mixture was heated and stirred at 180 ° C. for 60 minutes. Further, 8.59 g (0.03 mol) of 4,4′-diamino-3,3′-dicarboxyphenylmethane and 23.4 g of TG were added to this reaction solution, followed by heating and stirring at 180 ° C. for 5 hours, followed by filtration. It was. The resulting polyimidesiloxane reaction solution was a solution having a polymer solid concentration of 50% by weight and ηinh 0.18. The imidization rate was substantially 100%.
[0053]
Reference example 2
A glass flask having a volume of 500 ml was charged with 58.84 g (0.2 mol) of 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride and 170 g of TG, and heated and stirred at 180 ° C. in a nitrogen atmosphere. The mixture was cooled to around 100 ° C., 127.4 g (0.14 mol) of α, ω-bis (3-aminopropyl) polydimethylsiloxane (amino equivalent 455) and 50 g of TG were added, and the mixture was heated and stirred at 180 ° C. for 60 minutes. Further, after cooling to around room temperature, 13.52 g (0.03 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 4.56 g of 3,5 diaminobenzoic acid (0 0.03 mol) and 79 g of TG were added, and the mixture was heated and stirred at 180 ° C. for 5 hours, followed by filtration. The obtained polyimidesiloxane reaction solution was a solution having a polymer solid content concentration of 40% by weight and ηinh of 0.20. The imidization rate was substantially 100%.
[0054]
Example 1
In a glass container, 10 parts by weight of epoxy resin epicoat 1007 and 2 parts by weight of tertiary amine curing catalyst DBU with respect to 100 parts by weight of polyimidesiloxane solution obtained in Reference Example 1 and silicon-based antifoaming 4 parts by weight of the agent, 15.8 parts by weight of Aerosil 50 of finely divided silica, 1.8 parts by weight of Aerosil 130, 44 parts by weight of barium sulfate B-30, 11 parts by weight of Microace P-30 of talc And 11 parts by weight of MK-100 of mica was added and stirred and mixed uniformly to obtain a polyimidesiloxane solution composition (solution viscosity 360 poise). The quantity ratio of the carboxyl group of the polyimide siloxane and the epoxy group of the epoxy compound is 5.5: 1.
[0055]
This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
When the electrical insulating property (volume resistance) of the cured insulating film formed using this solution composition was measured, it was 5 × 10. ¹³ It was Ω · cm.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0056]
Example 2
A polyimide siloxane solution composition (340 poise) was obtained in the same manner as in Example 1 except that 5 parts by weight of Epicoat 1007 and 5 parts by weight of Epicoat 1004 were used as the epoxy resin. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 3.4: 1. This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0057]
Example 3
A polyimide siloxane solution composition (300 poise) was obtained in the same manner as in Example 1 except that 10 parts by weight of Epicoat 1004 was used as the epoxy resin. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 2.5: 1. This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
When the electric insulation (volume resistance) of the cured insulating film formed using this solution composition was measured, 4 × 10 4 was obtained. ¹⁴ It was Ω · cm.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0058]
Example 4
A polyimide siloxane solution composition (480 poise) was obtained in the same manner as in Example 1 except that 10 parts by weight of Epicoat 1004 was used as the epoxy resin and 0.3 parts by weight of Curazole 2E4MZ was used as the curing catalyst. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 2.5: 1. This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
When the electrical insulation (volume resistance) of the cured insulating film formed using this solution composition was measured, 1 × 10 ¹⁴ It was Ω · cm.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0059]
Example 5
A polyimide siloxane solution composition (300 poise) was obtained in the same manner as in Example 1 except that 13.8 parts by weight of Hiker ETBN 1300 × 40 was used as the epoxy resin. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 11: 1.
This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
When the electrical insulation (volume resistance) of the cured insulating film formed using this solution composition was measured, 2 × 10 ¹³ It was Ω · cm.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0060]
Example 6
Using the solution obtained by adding TG to the polyimidesiloxane solution obtained in Reference Example 2 to adjust the polyimidesiloxane concentration to 37%, the types and amounts shown in Table 1 are blended with respect to 100 parts by weight of polyimidesiloxane, and polyimidesiloxane Solution composition (430 poise) was obtained. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 3: 1. This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
When the electrical insulation (volume resistance) of the cured insulating film formed using this solution composition was measured, 1 × 10 ¹³ It was Ω · cm.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0061]
Example 7
A polyimidesiloxane solution composition (250 poise) was obtained in the same manner as in Example 1 except that 1 part by weight of Epicoat 157S70 was used as the epoxy resin. The quantity ratio of the carboxyl group of the polyimide siloxane and the epoxy group of the epoxy compound is 5.8: 1. This solution composition had little change in viscosity even after being allowed to stand at about 5 ° C. for 2 weeks, and was capable of screen printing.
When the electrical insulating property (volume resistance) of the cured insulating film formed using this solution composition was measured, it was 5 × 10. ¹³ It was Ω · cm.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0062]
Comparative Example 1
A polyimide siloxane solution composition (380 poise) was obtained in the same manner as in Example 1 except that 10 parts by weight of Epicoat 157S70 was used as the epoxy resin. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 0.6: 1.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0063]
Comparative Example 2
A polyimide siloxane solution composition (280 poise) was obtained in the same manner as in Example 1 except that 0.4 parts by weight of Epicoat 157S70 was used as the epoxy resin. The quantity ratio of the carboxyl group of the polyimidesiloxane and the epoxy group of the epoxy compound is 14.1: 1.
Table 2 shows the evaluation results for this solution composition and the cured insulating film.
[0064]
[Table 1]

[0065]
[Table 2]

[0066]
【The invention's effect】
Since the present invention is as described above, the following effects can be obtained.
That is, the present invention is excellent in storage stability and can be satisfactorily applied by a method such as screen printing on a substrate such as a flexible wiring board, and substantially curl is generated when it is heat-treated. (Non-curling), and the resulting cured insulating film has excellent heat resistance, solvent resistance, chemical resistance (solder flux resistance, solder copper foil discoloration resistance), bending resistance, and electrical properties. An insulating film composition suitable as a printing ink or coating varnish for forming an insulating film (protective film, solder resist, interlayer insulating layer, etc.) of an electronic component, particularly at 120 ° C. after being applied to a substrate It is possible to obtain a cured insulating film by a heat treatment at a low temperature of about or less, and the cured insulating film obtained by the heat treatment has particularly good adhesion to a base material and a sealing material, and further tin submerged. Small and good tin resistance Having Tsu key property, an insulating film such as an electronic component (protective film, solder resist, an interlayer insulating layer) can provide a suitable insulating coating composition as a printing ink or coating varnish for forming.
[Brief description of the drawings]
FIG. 1 is a component in which a chip component such as an IC is mounted on an insulating film base material, and the wiring pattern surface is first tin-plated, and then a cured insulating film (protective film) made of the polyimide siloxane insulating film composition of the present invention FIG. 2 is a schematic cross-sectional view of an example when a chip component is mounted on an insulating film base material in a procedure for forming a film.
[Explanation of symbols]
1: Polyimide film
2: Wiring pattern made of copper foil
3: Plated tin layer
4: Cured insulating film (protective film) made of an insulating composition
5: Joint part using gold bump 5
6: IC chip
7: Sealing material

Claims (9)

(A) Tetracarboxylic acid component, diaminopolysiloxane represented by the following general formula (1) 45 to 95 mol%, aromatic diamine 0.5 to 40 mol% having a substituent having reactivity with an epoxy group And an epoxy group which is a polyimide siloxane obtained from a diamine component consisting of 0 to 54.5 mol% of a diamine other than the aromatic diamine having a substituent having reactivity with the diaminopolysiloxane and the epoxy group; 100 parts by weight of an organic solvent-soluble resin having a reactive group and containing a polysiloxane skeleton, (b) 0.5 to 30 parts by weight of an epoxy compound having an epoxy equivalent of more than 1000 and 4000 or less, And (C) an insulating film composition containing an organic solvent and not containing a polyvalent isocyanate compound, the epoxy film of (a) Quantity ratio of the epoxy groups of the substituent and (b) reactive with the sheet groups 1: 1 to 13: insulating film composition characterized in that it is configured to be 1.

(In the formula, R ₁ represents a divalent hydrocarbon group or an aromatic group, R ₂ independently represents a monovalent carbon hydrogen group or an aromatic group, and n 1 represents an integer of 3 to 50.)   The insulating film composition according to claim 1, wherein the substituent having reactivity with the epoxy group is a carboxyl group or a hydroxyl group.   Furthermore, (d) 0.1-10 weight part of hardening accelerator is contained with respect to 100 weight part of organic solvent soluble resin which has a substituent which has reactivity with an epoxy group, and contains polysiloxane frame | skeleton. The composition for an insulating film according to claim 1, wherein the composition is an insulating film.   4. The insulating film composition according to claim 3, wherein the curing accelerator is a tertiary amine.   Furthermore, (e) 20-150 weight part of fine fillers are contained, The composition for insulating films in any one of the said Claims 1-4 characterized by the above-mentioned.   6. The insulating film composition according to claim 5, wherein the fine filler is a combination of finely divided silica and at least one of talc, mica, and barium sulfate.   The cured insulating film obtained by heat-processing the composition for insulating films in any one of Claims 1-6.   A method of forming a cured insulating film by applying a heat treatment at 50 ° C. to 210 ° C. after applying the composition for an insulating film according to claim 1 to a substrate. A step of tin plating the wiring pattern surface of the copper foil formed on the surface of the insulating film substrate;
A predetermined part on the surface of the insulating film substrate has (a) a tetracarboxylic acid component, 45 to 95 mol% of diaminopolysiloxane represented by the following general formula (1), and a substituent having reactivity with an epoxy group. A diamine component consisting of 0.5 to 40 mol% of an aromatic diamine and 0 to 54.5 mol% of a diamine other than the aromatic diamine having a substituent having reactivity with the diaminopolysiloxane and the epoxy group; 100 parts by weight of an organic solvent-soluble resin having a group having reactivity with an epoxy group and containing a polysiloxane skeleton, (b) 0.5 to 30 parts by weight of an epoxy compound, And (C) a composition for an insulating film comprising an organic solvent and not containing a polyvalent isocyanate compound, wherein The composition for insulating film is formed by applying or printing the composition for insulating film, wherein the quantity ratio of the substituent having the property to the epoxy group of (b) is 1: 1 to 13: 1. A process of forming an insulating film by curing by heat treatment at a low temperature of ℃ or less,
The process of mounting electronic components on this using a gold banff,
Next, a step of protecting the electronic component with a sealing material,
An electronic component mounting method comprising:

(In the formula, R ₁ represents a divalent hydrocarbon group or an aromatic group, R ₂ independently represents a monovalent carbon hydrogen group or an aromatic group, and n 1 represents an integer of 3 to 50.)

Images