JP4550324B2 - Low dielectric loss tangent resin composition, cured product thereof, and prepreg, laminate and multilayer printed board using the composition - Google Patents

Description

（式中、Ｒは炭化水素骨格を表し、Ｒ¹は、同一又は異なって、水素原子又は炭素数１〜２０の炭化水素基を表し、Ｒ²、Ｒ³及びＲ⁴は、同一又は異なって、水素原子又は炭素数１〜６のアルキル基を表し、ｍは１〜４の整数、ｎは２以上の整数を表す。）
で示される複数のスチレン基を有する重量平均分子量１０００以下の架橋成分と、高分子量体とを含有する樹脂組成物であって、該樹脂組成物を１８０℃、１００分で硬化させて得られる硬化物のガラス転移温度が１７０℃以上であるか、又は該硬化物の１７０℃における弾性率が５００ＭＰａ以上である樹脂組成物。
（２）スチレン基を重合しうる硬化触媒及びスチレン基の重合を抑制しうる重合禁止剤の少なくとも一方を更に含有する前記（１）に記載の組成物。
（３）前記架橋成分及び高分子量体の合計１００重量部に対して、前記硬化触媒の添加量が０．０００５〜１０重量部であり、前記重合禁止剤の添加量が０．０００５〜５重量部である前記（２）に記載の組成物。
（４）前記高分子量体のガラス転移温度が１７０℃以上である前記（１）〜（３）のいずれかに記載の組成物。
（５）前記高分子量体が、ブタジエン、イソプレン、スチレン、メチルスチレン、エチルスチレン、ジビニルベンゼン、アクリル酸エステル、アクリロニトリル、Ｎ−フェニルマレイミド及びＮ−ビニルフェニルマレイミドの少なくとも一種からなる重合体、置換基を有していてもよいポリフェニレンオキサイド、ならびに脂環式構造を有するポリオレフィンからなる群から選ばれる少なくとも一種の樹脂である前記（１）〜（４）のいずれかに記載の組成物。
（６）下記一般式：
【化４】

（式中、Ｒは炭化水素骨格を表し、Ｒ¹は、同一又は異なって、水素原子又は炭素数１〜２０の炭化水素基を表し、Ｒ²、Ｒ³及びＲ⁴は、同一又は異なって、水素原子又は炭素数１〜６のアルキル基を表し、ｍは１〜４の整数、ｎは２以上の整数を表す。）
で示される複数のスチレン基を有する重量平均分子量１０００以下の架橋成分と、高分子量体とを含有する樹脂組成物を硬化させて得られる硬化物であって、ガラス転移温度が１７０℃以上であるか、又は１７０℃における弾性率が５００ＭＰａ以上である硬化物。
（７）前記（１）〜（５）のいずれかに記載の組成物の硬化物。
（８）前記（１）〜（５）のいずれかに記載の組成物を、有機又は無機のクロス又は不織布に含浸させ、乾燥させてなるプリプレグ。
（９）前記（８）に記載のプリプレグの硬化物。
（１０）前記（８）に記載のプリプレグ又はその硬化物の両面又は片面に導体層が設置されてなる積層板。
（１１）前記（１０）に記載の積層板の導体層に配線加工を施した後、プリプレグを介して該積層板を積層接着してなる多層プリント基板。
【０００６】
(作用)
ジビニルベンゼンの硬化物の耐熱性が高く、その誘電率及び誘電正接が低いことはすでに述べた。本発明により、スチレン基を複数有する重量平均分子量が１０００以下で不揮発性の炭化水素骨格の架橋成分と、高分子量体とを含有する樹脂組成物が、硬化時にひび割れせず、誘電率及び誘電正接が低い硬化物を与えることが明らかとなった。スチレン基間をアルキレン基のような柔軟な炭化水素骨格で結合しているため、硬化時のひび割れが生じないものである。また、硬化後のガラス転移温度が１７０℃以上であるか、又は硬化後の１７０℃における弾性率が５００ＭＰａ以上である低誘電正接樹脂組成物は、金ワイヤボンディング、はんだ付等の高温での加工プロセスにおいて変形が小さいので、マルチチップモジュール、多層プリント基板等の電子部品のための絶縁材料に適する。
【０００７】
【発明の実施の形態】
本発明の樹脂組成物及びその硬化物について説明する。
本発明の樹脂組成物は、下記一般式：
【化５】

（式中、Ｒは炭化水素骨格を表し、Ｒ¹は、同一又は異なって、水素原子又は炭素数１〜２０の炭化水素基を表し、Ｒ²、Ｒ³及びＲ⁴は、同一又は異なって、水素原子又は炭素数１〜６のアルキル基を表し、ｍは１〜４の整数、ｎは２以上の整数を表す。）
で示される複数のスチレン基を有する重量平均分子量１０００以下の架橋成分と、高分子量体とを含有する樹脂組成物であって、該樹脂組成物を１８０℃、１００分で硬化させて得られる硬化物のガラス転移温度が１７０℃以上であるか、又は該硬化物の１７０℃における弾性率が５００ＭＰａ以上である樹脂組成物であり、前記硬化物のガラス転移温度が１７０〜３００℃であるか、又は該硬化物の１７０℃における弾性率が５００〜３０００ＭＰａであることが好ましい。
【０００８】
本発明の硬化物は、前記架橋成分と、高分子量体とを含有する樹脂組成物を硬化させて得られる硬化物であって、ガラス転移温度が１７０℃以上であるか、又は１７０℃における弾性率が５００ＭＰａ以上である硬化物であり、ガラス転移温度が１７０〜３００℃であるか、又は１７０℃における弾性率が５００〜３０００ＭＰａであることが好ましい。
【０００９】
なお、本明細書中において、ガラス転移温度とは、昇温速度５℃／分の条件で動的粘弾性特性を観測した際に、損失弾性率と貯蔵弾性率の比であるｔａｎδがピークとなる温度を示すものであり、弾性率とは同条件で測定した１７０℃における弾性率を示すものである。誘電率及び誘電正接が低く、ガラス転移温度が高く、高温下における弾性率が高い本発明の樹脂組成物の硬化物を絶縁層に使用するプリント基板を使用することにより、電気信号の誘電損失を低く押さえ、かつ金ワイヤボンディング、ハンダ付等の高温での加工プロセスにおける変形を抑制することができる。
【００１０】
前記式において、Ｒで表される炭化水素骨格は、該架橋成分の重量平均分子量が１０００以下となるものであれば特に制限はない。即ち、Ｒで表される炭化水素骨格は、スチレン基における置換基、Ｒ¹、Ｒ²、Ｒ³及びＲ⁴の有無及びその大きさ、ｍ及びｎの数に応じて適宜選択することができるが、一般には炭素数１〜６０であり、好ましくは炭素数２〜３０である。Ｒで表される炭化水素骨格は、直鎖状又は分枝状のいずれでもよく、また、脂環式構造、芳香族環構造等の環構造を１つ以上含んでいてもよく、更に、ビニレン、エチニレン等の不飽和結合を含んでいてもよい。
【００１１】
Ｒで表される炭化水素骨格としては、例えば、エチレン、トリメチレン、テトラメチレン、メチルトリメチレン、メチルテトラメチレン、ペンタメチレン、メチルペンタメチレン、シクロペンチレン、シクロヘキシレン、フェニレン、フェニレンジエチレン、キシリレン、１−フェニレン−３−メチルプロペニレン等が挙げられる。
【００１２】
前記式において、Ｒ¹で表される炭化水素基としては、炭素数１〜２０、好ましくは炭素数１〜１０の、直鎖状もしくは分枝状のアルキル基、例えばメチル、エチル、ｎ−プロピル、イソプロピル、ｎ−ブチル、イソブチル、ｓ−ブチル、ペンチル、ヘキシル、デシル、エイコシル；炭素数２〜２０、好ましくは炭素数２〜１０の、直鎖状もしくは分枝状のアルケニル基、例えばビニル、１−プロペニル、２−プロペニル、２−メチルアリル；アリール基、例えばフェニル、ナフチル、ベンジル、フェネチル、スチリル、シンナミルが挙げられる。
【００１３】
前記式において、ｎが２以上の整数であることからＲ¹は複数存在し、ｍが２〜４の整数である場合も、Ｒ¹は複数存在するが、そのような複数存在するＲ¹は同一でも異なっていてもよく、その結合位置も同一でも異なっていてもよい。
前記式において、Ｒ²、Ｒ³又はＲ⁴で表されるアルキル基としては、炭素数１〜６の直鎖状もしくは分枝状のアルキル基、例えばメチル、エチル、ｎ−プロピル、イソプロピル、ｎ−ブチル、イソブチル、ヘキシルが挙げられる。
前記式において、置換されていてもよいビニル基［（Ｒ³）（Ｒ⁴）Ｃ＝Ｃ（Ｒ²）−］は、ベンゼン環上、Ｒに対して、好ましくはメタ位又はパラ位に存在する。
【００１４】
本発明に用いる架橋成分としては、複数の（置換されていてもよい）スチレン基を有する重量平均分子量１０００以下の多官能性モノマーが好ましい。スチレン基は反応性が高く、誘電率及び誘電正接が非常に低い。架橋成分の骨格には誘電率及び誘電正接の観点から炭化水素骨格を採用することが好ましい。これによって、スチレン基の低誘電率性及び低誘電正接性を損なうことなく、該架橋成分に不揮発性及び柔軟性を付与することができる。また、重量平均分子量１０００以下の架橋成分を選択することによって、比較的低い温度で溶融流動性を示し、有機溶媒への溶解性もよくなるため、成形加工及びワニス化が容易になる。架橋成分の重量平均分子量が大きすぎると、溶融流動性が低くなり、成形加工の際に架橋が生じて成形不良となる場合がある。該架橋成分の重量平均分子量は１０００以下であれば制限はないが、好ましくは２００〜５００である。
【００１５】
架橋成分の好ましい例としては、１，２−ビス（ｐ−ビニルフェニル）エタン、１，２−ビス（ｍ−ビニルフェニル）エタン、１−（ｐ−ビニルフェニル）−２−（ｍ−ビニルフェニル）エタン、１，４−ビス（ｐ−ビニルフェニルエチル）ベンゼン、１，４−ビス（ｍ−ビニルフェニルエチル）ベンゼン、１，３−ビス（ｐ−ビニルフェニルエチル）ベンゼン、１，３−ビス（ｍ−ビニルフェニルエチル）ベンゼン、１−（ｐ−ビニルフェニルエチル）−４−（ｍ−ビニルフェニルエチル）ベンゼン、１−（ｐ−ビニルフェニルエチル）−３−（ｍ−ビニルフェニルエチル）ベンゼン及び側鎖にビニル基を有するジビニルベンゼン重合体（オリゴマー）等が挙げられる。これらの架橋成分は２種以上組み合わせて使用することもできる。
【００１６】
本発明に好ましく用いられる架橋成分の合成方法としては、特開平１１−６０５１９号公報に記載の方法で合成されたハロゲノアルキルスチレンをグリニャール反応によって種々のハロゲン化物とカップリングする方法、Ｍａｋｒｏｍｏｌ．Ｃｈｅｍ．ｖｏｌ．１８７、２３頁（１９８６）記載の側鎖にビニル基を有するジビニルベンゼンオリゴマーの合成方法が挙げられるが、これらに限定されない。このようにして得られた架橋成分は、特に硬化触媒を添加しなくとも１８０℃以下の比較的低い温度で架橋し、耐熱性が高く、誘電率及び誘電正接の低い硬化物を与える。しかし、該架橋成分を高分子量体と組み合わせずに単独で使用した場合には、プリプレグ化した際のタックフリー性が得られない場合や、また、硬化後に十分な機械強度を得られない場合がある。
【００１７】
本発明では前述の架橋成分と高分子量体とを組み合わせることによって、タックフリー性及び硬化物の機械強度の向上を図ることを特徴としている。本発明に使用される高分子量体は、そのガラス転移温度が１７０℃以上であるか、又は１７０℃における弾性率が５００ＭＰａ以上であり、かつワニス化が容易な可溶性ポリマーであることが好ましく、ガラス転移温度が１７０〜３００℃であるか、又は１７０℃における弾性率が５００〜３０００ＭＰａであることが更に好ましい。高分子量体が硬化性を有する場合には、硬化後のガラス転移温度が１７０℃以上であるか又は１７０℃における弾性率が５００ＭＰａ以上であることが好ましく、硬化後のガラス転移温度が１７０〜３００℃であるか又は１７０℃における弾性率が５００〜３０００ＭＰａであることが更に好ましい。このような高分子量体の具体的な例としては、ブタジエン、イソプレン、スチレン、メチルスチレン、エチルスチレン、ジビニルベンゼン、アクリル酸エステル（例えば、アクリル酸メチル、アクリル酸ブチル、アクリル酸フェニルなど）、アクリロニトリル及びＮ−フェニルマレイミドから選択される単量体とＮ−ビニルフェニルマレイミドとの共重合体、置換基を有していてもよいポリフェニレンオキサイドならびに脂環式構造を有するポリオレフィン等が挙げられるが、これらに限定されない。本発明に用いる架橋成分は殆どの有機溶媒に可溶であるため、種々の高分子量体と混合し、均一なワニスを得ることができる。前記有機溶媒としては、例えば、アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類、トルエン、キシレン等の芳香族炭化水素類、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド等のアミド類、ジエチルエーテル、エチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテル、テトラヒドロフラン、ジオキサン等のエーテル類、メタノール、エタノール、イソプロパノール等のアルコール類等が挙げられ、これらの有機溶剤は単独で、又は２種以上混合して用いることができる。ブタジエン、イソプレン及びアクリル酸エステルなどのゴム状成分は、それを含む樹脂組成物の硬化物に柔軟性及び接着性を付与し、かつ塗膜に平滑性を付与する。スチレン、エチルスチレン及び／又はアクリロニトリルは、先のゴム状成分と共重合することによって、その硬化物の耐熱性を向上させる働きを有する。ジビニルベンゼン及び／又はＮ−ビニルフェニルマレイミドを用い、公知のイオン重合法によって、側鎖に官能基を有する高分子量体を合成することができる。特にＮ−ビニルフェニルマレイミドは、アニオン重合によってマレイミド基のみが、カチオン重合によってスチレン基のみが重合するため、各種単量体との共重合が容易であり、その共重合体のガラス転移温度は高い。また、側鎖に官能基を有する高分子量体は、前記架橋成分と反応するため、該高分子量体と架橋成分とを含む樹脂組成物は硬化後の相分離がおさえられ、強固な硬化物を与える。ポリフェニレンオキサイド及び脂環式構造を有するポリオレフィンは耐熱性ポリマーであり、前記架橋成分とアロイ化することによって、硬化物に柔軟性及び接着性を付与し、その機械強度を向上させることができる。これらの高分子量体は単独で用いても、複合して用いてもよい。例えば、ポリフェニレンオキサイドとポリブタジエンとを組合せるのが好ましい。
【００１８】
本発明の組成物には、その硬化物の機械強度の向上、熱膨張係数の低減、誘電率の調整、軽量化又は表面粗化によるめっき配線との接着力の向上等の目的のために充填剤を添加することができる。機械強度の向上のためには、硼酸アルミニウムウィスカー又はカーボン繊維等の繊維状の充填剤を添加することが好ましい。熱膨張係数の低減のためには、酸化珪素等の粒径の異なる球状充填剤を高い割合で充填することが好ましい。誘電率の調整においては、誘電率の高い酸化チタンを添加して誘電率を高めるか、又は誘電率の低い硼珪酸ガラスバルーンを添加することによって誘電率を低減させるのが好ましい。表面粗化のためには、炭酸カルシウム、水酸化マグネシウムのような、アルカリ水溶液に可溶な充填剤を添加することが好ましい。これら充填剤は単独でも又は複合して用いてもよい。
【００１９】
本発明の樹脂組成物に含まれる架橋成分、高分子量体及び充填剤の添加量に関しては特に制限はないが、架橋成分が５〜９５重量部、高分子量体が９５〜５重量部、充填剤が７０〜５重量部の範囲で添加するのが好ましい。前記組成範囲内で、成膜性の付与、強度の向上、熱膨張係数の低減、誘電率の調整、軽量化及び表面粗化によるめっき配線との接着力の向上等の目的に応じて組成を調整することができる。より好ましい組成としては、架橋成分が５０〜９５重量部、高分子量体が５０〜５重量部、充填剤が７０〜５重量部であり、更に好ましい組成としては、架橋成分が５０〜８０重量部、高分子量体が５０〜２０重量部、充填剤が７０〜５重量部であり、この組成範囲により架橋性の官能基を持たない高分子量体を用いた場合にもその硬化物の耐溶剤性が保たれる。
【００２０】
本発明の樹脂組成物は硬化触媒を添加しなくとも加熱のみによって硬化することができるが、硬化効率の向上を目的として、スチレン基を重合しうる硬化触媒を添加することができる。その添加量には特に制限はないが、硬化触媒の残基が誘電特性に悪影響を与える恐れがあるので、前記架橋成分及び高分子量体の合計１００重量部に対して、０．０００５〜１０重量部とすることが望ましい。硬化触媒を前記範囲で添加することにより、スチレン基の重合反応が促進され、低温で強固な硬化物を得ることができる。スチレン基の重合を開始しうるカチオン又はラジカル活性種を、熱又は光によって生成する硬化触媒の例を以下に示す。カチオン重合開始剤としては、ＢＦ₄、ＰＦ₆、ＡｓＦ₆、ＳｂＦ₆を対アニオンとするジアリルヨードニウム塩、トリアリルスルホニウム塩及び脂肪族スルホニウム塩が挙げられ、旭電化工業製ＳＰ−７０、１７２、ＣＰ−６６、日本曹達製ＣＩ−２８５５、２８２３、三新化学工業製ＳＩ−１００Ｌ及びＳＩ−１５０Ｌ等の市販品を使用することができる。ラジカル重合開始剤としては、ベンゾイン及びベンゾインメチルのようなベンゾイン系化合物、アセトフェノン及び２，２−ジメトキシ−２−フェニルアセトフェノンのようなアセトフェノン系化合物、チオキサントン及び２，４−ジエチルチオキサントンのようなチオキサンソン系化合物、４，４’−ジアジドカルコン、２，６−ビス（４’−アジドベンザル）シクロヘキサノン及び４，４’−ジアジドベンゾフェノンのようなビスアジド化合物、アゾビスイソブチルニトリル、２、２−アゾビスプロパン、ｍ，ｍ’−アゾキシスチレン及びヒドラゾンのようなアゾ化合物、ならびに２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサン及び２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキシン−３、ジクミルパーオキシドのような有機過酸化物等が挙げられる。特に、官能基を持たない化合物の水素引き抜きを生じさせ、架橋成分と高分子量体間の架橋をもたらしうる有機過酸化物又はビスアジド化合物を添加することが望ましい。
【００２１】
本発明の樹脂組成物には、保存安定性を増すために重合禁止剤を添加することもできる。その添加量は、誘電特性、硬化時の反応性を著しく阻害しないような範囲であることが好ましく、前記架橋成分及び高分子量体の合計１００重量部に対して、０．０００５〜５重量部とすることが望ましい。重合禁止剤を前記範囲で添加すると、保存時の余計な架橋反応を抑制することができ、また、硬化時に著しい硬化障害をもたらすこともない。重合禁止剤の例としては、ハイドロキノン、ｐ−ベンゾキノン、クロラニル、トリメチルキノン、４−ｔ−ブチルピロカテコール等のキノン類及び芳香族ジオール類が挙げられる。
【００２２】
本発明の樹脂組成物は、有機又は無機のクロス又は不織布に含浸し、乾燥させることによりプリプレグとして用いることができる。プリプレグの基材については特に制限はなく、各種ガラスクロス、ガラス不織布、アラミド不織布及び多孔質ＰＴＦＥ等を用いることができる。プリプレグは、樹脂組成物を用いて作製したワニスに、基材となるクロス又は不織布を浸し、その後これを乾燥することにより作製される。含浸後の乾燥条件は樹脂組成物によるが、例えば溶媒としてトルエンを使用した場合は、８０〜１３０℃で３０〜９０分程度乾燥するのが好ましい。
【００２３】
本発明のプリプレグに電解銅箔等の導体箔を重ね、加熱プレス加工することによって、表面に導体層を有する積層板を作製することができる。銅箔の厚さは、１２〜３６μｍ程度であるのが好ましい。加圧プレス加工の条件は、樹脂組成物によるが、例えば高分子量体として環状ポリオレフィンを使用した場合には、１２０〜１８０℃、１．０〜５ＭＰａで１〜３時間成形するのが好ましい。
【００２４】
この積層板の導体層を通常のエッチング法によって配線加工し、これを前記プリプレグを介して複数積層し、加熱プレス加工することによって多層化して多層プリント基板を作製することもできる。このようにして得られた多層プリント基板は誘電正接が低いため、誘電損失の小さな多層プリント基板となる。また、本発明の多層プリント基板は、ガラス転移温度が高く、かつ高温下での弾性率が高いため金ワイヤボンディング、ハンダ付け等の高温での加工プロセスに十分対応できる。
【００２５】
【実施例】
以下に実施例及び比較例を示して本発明を具体的に説明するが、本発明はこれらに限定されない。なお、以下の説明中に部とあるのは、特に断りのない限り重量部を指す。
表１〜３に本発明の実施例と比較例の組成及びその特性を示す。以下に実施例及び比較例に使用した試薬の名称、合成方法、ワニスの調製方法及び硬化物の評価方法を説明する。
【００２６】
（１）１，２−ビス（ビニルフェニル）エタン（ＢＶＰＥ）の合成
１，２−ビス（ビニルフェニル）エタン（ＢＶＰＥ）は、以下に示すような公知の方法で合成した。５００ｍｌの三つ口フラスコにグリニャール反応用粒状マグネシウム（関東化学製）５．３６ｇ（２２０ｍｍｏｌ）をとり、滴下ロート、窒素導入管及びセプタムキャップを取り付けた。窒素気流下、スターラーによってマグネシウム粒を攪拌しながら、系全体をドライヤーで加熱脱水した。乾燥テトラヒドロフラン３００ｍｌをシリンジにとり、セプタムキャップを通じて注入した。溶液を−５℃に冷却した後、滴下ロートを用いてビニルベンジルクロライド（ＶＢＣ、東京化成製）３０．５ｇ（２００ｍｌ）を約４時間かけて滴下した。滴下終了後、０℃／２０時間、攪拌を続けた。反応終了後、反応溶液をろ過して残存マグネシウムを除き、エバポレーターで濃縮した。濃縮溶液をヘキサンで希釈し、３．６％塩酸水溶液で１回、純水で３回洗浄し、次いで硫酸マグネシウムで脱水した。脱水溶液をシリカゲル（和光純薬製ワコーゲルＣ３００）／ヘキサンのショートカラムに通して精製し、真空乾燥してＢＶＰＥを得た。得られたＢＶＰＥはｍ−ｍ体（液状）、ｍ−ｐ体（液状）、ｐ−ｐ体（結晶）の混合物であり、収率は９０％であった。¹Ｈ−ＮＭＲによって構造を調べたところその値は文献値と一致した（６Ｈ−ビニル：α−２Ｈ、６．７、β−４Ｈ、５．７、５．２；８Ｈ−アロマティック：７．１〜７．３５；４Ｈ−メチレン：２．９）。
このＢＶＰＥを架橋成分として用いた。
【００２７】
（２）ポリジビニルベンゼン（ｐｏｌｙＤＶＢ）の合成
ポリジビニルベンゼン（ｐｏｌｙＤＶＢ）は、以下に示すような公知の方法で合成した。５２０ｍｌのジイソプロピルアミンＴＨＦ溶液（ジイソプロピルアミン含有量１０１ｇ＝１ｍｏｌ）を窒素置換した１０００ｍｌの三つ口フラスコに入れた。１１ｍｌのｎ−ブチルリチウムヘキサン溶液（ｎ−ブチルリチウム含有量１．９ｇ＝２０ｍｍｏｌ）を加えた。１４０ｍｍｏｌ（１８．２ｇ）のジビニルベンゼンを加えた。６０分間室温で攪拌した。メタノールを加えて反応を停止した。反応溶液をエバポレーターで濃縮した後、冷メタノールで再沈、乾燥してポリジビニルベンゼンを得た。収率は約５０％で、分子量は約２００００であった。ポリジビニルベンゼンは可溶性であり、側鎖にビニル基を有していた（４Ｈ−アロマティック：６．５−７．２；３Ｈ−ビニル：５−６．５；３Ｈ−メチレン、メチン：１−２）。このポリジビニルベンゼンを比較例５の架橋成分として使用した。
【００２８】
（３）その他の試薬
その他の高分子量体、架橋成分として、以下に示すものを使用した。
高分子量体；
Ｚｅｏｎｏｒ：日本ゼオン製、環状ポリオレフィン（Ｚｅｏｎｏｒ１６００Ｒ）ＰＰＥ：アルドリッチ製、ポリ−２，６−ジメチル−１，４−フェニレンオキシド
比較例４の架橋成分；
ＤＶＢ：和光純薬製、ジビニルベンゼン
硬化触媒；
２５Ｂ：日本油脂製２，５−ジメチル−２，５−ビス（ｔ−ブチルパーオキシ）ヘキシン−３（パーヘキシン２５Ｂ）
有機不織布；
クラレ製ベクトランＫ−９
デュポン製サーマウントＥ２１０
ガラスクロス；
日東紡製＃２１１６
【００２９】
（４）ワニスの調製方法
所定量の高分子量体、架橋成分及び硬化触媒をクロロホルム又は二硫化炭素に溶解することによって樹脂組成物のワニスを作製した。
【００３０】
（５）樹脂板の作製
前記ワニスをＰＥＴフィルムに塗布して乾燥した後に、これを剥離してテフロン製のスペーサー内に所定量入れ、ポリイミドフィルム及び鏡板を介し、真空下で、加熱及び加圧して硬化物としての樹脂板を得た。加熱条件は、１２０℃／３０分、１５０℃／３０分、１８０℃／１００分で、プレス圧力１．５ＭＰａの多段階加熱とした。樹脂板の大きさは７０×７０×１ｍｍとした。
【００３１】
（６）プリプレグの作製
実施例において作製したプリプレグはすべて、樹脂組成物のワニスを所定の有機不織布又はガラスクロスに含浸して、室温にて約１時間、９０℃で６０分間乾燥することにより作製した。使用した基材名及び樹脂含有率（高分子量体と架橋成分の含有率）を表３に示した。
【００３２】
（７）プリプレグ硬化物の作製
積層板とした際のプリプレグの特性を知るため、前記の方法で作製したプリプレグを真空下、加熱及び加圧して模擬基板を作製した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１．５ＭＰａの多段階加熱とした。模擬基板は７０×７０×０．１４〜０．３ｍｍとした。
【００３３】
（８）誘電率及び誘電正接の測定
誘電率、誘電正接は空洞共振法（アジレントテクノロジー製８７２２ＥＳ型ネットワークアナライザー、関東電子応用開発製空洞共振器）によって、１０ＧＨｚでの値を観測した。
【００３４】
（９）引張強度及び伸びの測定
引張強度及び伸びは、島津製ＡＧＳ−１００型引張試験機を用い、厚さ１ｍｍ、幅１ｍｍ、長さ７０ｍｍの柱状サンプルを用い、室温、支点間距離２０ｍｍ引張速度１０ｍｍ／分の条件で測定した。
【００３５】
（１０）ガラス転移温度（Ｔｇ）、弾性率
Ｔｇ、弾性率は、アイティー計測制御製ＤＶＡ−２００型粘弾性測定装置（ＤＭＡ）を用いて、ｔａｎδのピーク位置、１７０℃における弾性率を観測して求めた。サンプル形状及び支点間距離は引張強度用サンプルと同じであり、昇温速度は５℃／分とした。
【００３６】
（１１）ピール強度
ピール強度測定用サンプルは、各樹脂組成物を電解銅箔（１８μｍ）の粗面上に樹脂板の作製方法と同様の条件で樹脂層を形成して作製した。樹脂層は厚さ２ｍｍ、大きさは７０×７０ｍｍとした。樹脂層上の電解銅箔を幅１０ｍｍに切断して、そのピール強度を測定した。
【００３７】
［比較例１］
比較例１は、高分子量体としての環状ポリオレフィン樹脂Ｚｅｏｎｏｒのみからなる樹脂組成物の例である。この組成物の硬化物は、所定量のペレットを金属製のスペーサー内に入れ、ポリイミドフィルム及び鏡板を介して真空下、加熱及び加圧することにより樹脂板として作製した。加熱条件は２６０℃／３０分、プレス圧力１．５ＭＰａとした。樹脂板は７０×７０×１ｍｍとした。この樹脂板は、誘電率が２．２０、誘電正接が０．０００７とどちらも非常に低く、Ｔｇは１８５℃、弾性率は１１９０ＭＰａとどちらも高い。ただし、本樹脂は硬化性を有していないため有機溶剤中で膨潤する。また、成形時の加熱温度は２６０℃程度必要であった。
【００３８】
［比較例２］
比較例２は、高分子量体としてのＰＰＥのみからなる樹脂組成物の例である。
この組成物の硬化物は、所定量の樹脂粉末を金属製のスペーサー内に入れ、ポリイミドフィルム及び鏡板を介して真空下、加熱及び加圧することにより樹脂板として作製した。加熱条件は３２０℃／３０分、プレス圧力１．５ＭＰａとした。樹脂板は７０×７０×１ｍｍとした。この樹脂板は、誘電率が２．４１、誘電正接が０．００２２と非常に低く、Ｔｇは２２９℃、弾性率は２０００ＭＰａとどちらも高い。ただし、本樹脂は硬化性を有していないため有機溶剤中で膨潤する。また、成形温度は３２０℃程度必要であった。
【００３９】
［比較例３］
比較例３は、架橋成分１，２−ビス（ビニルフェニル）エタン（ＢＶＰＥ）及びＢＶＰＥの重量に対して１ｗｔ％の硬化触媒２５Ｂを含んでなる樹脂組成物の例である。この組成物の硬化物は、テフロンスペーサーを貼り付けた二枚のガラス板の間に無溶剤の状態で樹脂組成物を注入して密閉し、加熱して硬化することにより樹脂板として作製した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分の多段階加熱とした。樹脂板は７０×７０×１ｍｍとした。作製した樹脂板は、誘電率が２．５６、誘電正接が０．００１７と低く、Ｔｇが４００℃以上であり、弾性率は２５９０ＭＰａとどちらも高い。硬化性を有しているため耐溶剤性にも優れる。硬化温度は１８０℃と比較的低い。しかし、引張強度が３１．２ＭＰａ、伸びが２％と小さい点で問題を有する。
【００４０】
［実施例１〜３］
実施例１〜３は、高分子量体であるＺｅｏｎｏｒと架橋成分であるＢＶＰＥをそれぞれ異なった配合比で含み、更に樹脂成分の重量に対して１ｗｔ％の硬化触媒２５Ｂを含んでなる樹脂組成物の例である。これらの組成物の硬化物は、溶媒に二硫化硫黄を使用してワニスを調製し、上述の方法で樹脂板として作製した。
各実施例から明らかなように、各樹脂板の誘電率及び誘電正接は非常に低く、誘電率は２．２７〜２．３５であり、誘電正接は０．００１３〜０．００１７であった。その他の特性は添加した高分子量体の特性が反映され、引張強度が６８〜７９ＭＰａ、伸びが２１〜２８％、Ｔｇが１７８〜１８３℃、弾性率が１０００〜１１３０ＭＰａ、ピール強度が０．７〜１．２Ｎ／ｍと優れた値を示した。本樹脂組成物は硬化性を有するため耐溶剤性も優れている。また、成形温度は１８０℃であり、低い温度での成形が可能であった。
【００４１】
［実施例４〜６］
実施例４〜６は、高分子量体であるＰＰＥと架橋成分であるＢＶＰＥをそれぞれ異なった配合比で含み、更に樹脂成分の重量に対して１ｗｔ％の硬化触媒２５Ｂを含んでなる樹脂組成物の例である。これらの樹脂組成物の硬化物は、溶媒にクロロホルムを使用してワニスを調製し、上述の方法で樹脂板として作製した。
各実施例から明らかなように本樹脂組成物の誘電率及び誘電正接は非常に低く、誘電率は２．４３〜２．４５であり、誘電正接は０．００１７〜０．００１９であった。その他の特性は添加した高分子量体の特性が反映され、引張強度が６３〜８２ＭＰａ、伸びが２６〜４７％、Ｔｇが２１０〜２２５℃、弾性率が２４７０〜２５３０ＭＰａ、ピール強度が０．７〜１．２Ｎ／ｍと優れた値を示した。
本樹脂組成物は硬化性を有するため耐溶剤性にも優れている。また、成形温度は１８０℃であり、低い温度での成形が可能であった。
前記比較例１〜３及び実施例１〜６の結果を、以下の表１に示す；
【００４２】
【表１】

【００４３】
［比較例４］
比較例４は、ＤＶＢ及びＤＶＢの重量に対して１ｗｔ％の硬化触媒２５Ｂを含むが、高分子量体を含まない樹脂組成物の例である。この組成物の硬化物は、溶媒を使用せずに、上述の方法で樹脂板として作製した。この樹脂板は非常に脆く、硬化時及び冷却時にひび割れが生じて、評価できなかった。
【００４４】
［比較例５］
比較例５は分子量が約２００００のＰｏｌｙＤＶＢを架橋成分として、ＰＰＥを高分子量体としてそれぞれ５０重量部含み、更に樹脂成分の重量に対して１ｗｔ％の硬化触媒２５Ｂを含んでなる樹脂組成物の例である。この組成物の硬化物は、溶媒にクロロホルムを使用してワニスを調製し、上述の方法で樹脂板として作製した。この樹脂板は架橋剤の分子量が大きいため、溶融流動性が不十分となり、成形板が作製できないことが確認された。
【００４５】
［比較例６］
比較例６は、高分子量体としてのＰＰＥ及び架橋成分としてのＢＶＰＥをそれぞれ５０重量部含み、更に硬化触媒を樹脂成分の合計重量に対して２０ｗｔ％と過剰に含んでなる樹脂組成物の例である。この組成物の硬化物は、溶媒にクロロホルムを使用してワニスを調製し、上述の方法で樹脂板として作製した。この樹脂板は、硬化触媒を過剰に加えたため、誘電率が２．６、誘電正接が０．００３と増加した。また、硬化速度が速いため成形時の流動性が低下して樹脂板の形、厚さが不均一になった。
【００４６】
［実施例７及び８］
実施例７及び８は、高分子量体としてのＰＰＥ及び架橋成分としてのＢＶＰＥをそれぞれ５０重量部含み、更に硬化触媒２５Ｂを樹脂成分の重量に対してそれぞれ１０ｗｔ％又は５ｗｔ％含んでなる樹脂組成物の例である。この組成物の硬化物は、溶媒にクロロホルムを使用してワニスを調製し、上述の方法で樹脂板として作製した。この樹脂板は、硬化触媒量が１０ｗｔ％以下であれば、成形不良は発生しない。また、誘電率は２．４３、誘電正接は０．００１８〜０．００１９であり、著しい特性低下は認められなかった。
前記比較例４〜６及び実施例７〜８の結果を以下の表２に示す；
【００４７】
【表２】

【００４８】
［実施例９〜１１］
表３には、本発明の樹脂組成物に各種基材を含浸させて作製したプリプレグの構成及び誘電特性を示した。作製したプリプレグは何れもタックフリー性を有する。プリプレグの作製には、実施例５で調製した樹脂組成物、すなわち、高分子量体としてのＰＰＥ及び架橋成分としてのＢＶＰＥをそれぞれ５０重量部ならびに樹脂成分の重量に対して１ｗｔ％の硬化触媒２５Ｂを含んでなる樹脂組成物を使用した。プリプレグは、有機溶媒としてクロロホルムを使用してワニスを調製し、このワニスを所定の有機不織布又はガラスクロスに含浸して、室温にて約１時間、９０℃で６０分間乾燥することにより作製した。各基材名及び樹脂含有率を表３に示した。前記のように作製したプリプレグを、真空下、加熱及び加圧して硬化させ模擬基板を作製した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１．５ＭＰａの多段階加熱とした。模擬基板は７０×７０×０．１４〜０．３ｍｍとした。ガラスクロス（＃２１１６）を基材とする実施例９の模擬基板は、誘電率が３．１２、誘電正接が０．００３８、有機不織布（Ｋ−９）を基材とする実施例１０の模擬基板は誘電率２．５１、誘電正接が０．００２７、Ｅ２１０を基材とする実施例１１の模擬基板は誘電率２．６１、誘電正接０．００２４であった。何れも良好な誘電特性を有する。
前記実施例９〜１１の結果を以下の表３に示す；
【００４９】
【表３】

【００５０】
［実施例１２］
実施例９で作製したプリプレグの両面に電解銅箔の粗面を張り付け、真空下、加圧、加熱して両面銅張積層板を作製した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１．５ＭＰａとした。銅箔とプリプレグは良好な接着性を示した。これにより多層プリント基板の作製が可能となった。
【００５１】
［実施例１３］
以下に本発明の多層プリント基板の作成例を示す。（Ａ）実施例１２で得た両面銅張積層板の片面にフォトレジスト（日立化成製ＨＳ４２５）をラミネートして全面に露光した。次いで残る銅表面にフォトレジスト（日立化成製ＨＳ４２５）をラミネートしてテストパターンを露光し、未露光部分のフォトレジストを１％炭酸ナトリウム液で現像した。（Ｂ）硫酸５％、過酸化水素５％のエッチング液で露出した銅箔をエッチング除去して、両面銅張積層板の片面に導体配線を形成した。（Ｃ）３％水酸化ナトリウム溶液で残存するフォトレジストを除去し、片面に配線を有する配線基板を得た。同様にして２枚の配線基板を作製した。（Ｄ）二枚の配線基板の配線側の面に実施例９のプリプレグを挟み、真空下、加熱、加圧して多層化した。加熱条件は１２０℃／３０分、１５０℃／３０分、１８０℃／１００分、プレス圧力１．５ＭＰａの多段階加熱とした。（Ｅ）作製した多層板の両面の外装銅にフォトレジスト（日立化成製ＨＳ４２５）をラミネートしてテストパターンを露光し、未露光部分のフォトレジストを１％炭酸ナトリウム液で現像した。（Ｆ）硫酸５％、過酸化水素５％のエッチング液で露出した銅箔をエッチング除去し、３％水酸化ナトリウム溶液で残存するフォトレジストを除去して外装配線を形成した。（Ｇ）内層配線と外装配線を接続するスルーホールをドリル加工で形成した。（Ｈ）配線基板をめっき触媒のコロイド溶液に浸して、スルーホール内、基板表面に触媒を付与した。（Ｉ）めっき触媒の活性化処理の後、無電解めっき（日立化成製ＣＵＳＴ２０００）により、約１μｍの種膜を設けた。（Ｊ）フォトレジスト（日立化成製ＨＮ９２０）を配線基板の両面にラミネートした。（Ｋ）スルーホール部及び配線基板の端部をマスクして露光後、３％炭酸ナトリウムで現像して開孔部を設置した。（Ｌ）配線基板の端部に電極を設置して電解めっきによってスルー部分にめっき銅を約１８μｍ形成した。（Ｍ）電極部分を切断除去し、残存するフォトレジストを５％水酸化ナトリウム水溶液で除去した。（Ｎ）硫酸５％、過酸化水素５％のエッチング液に配線基板を浸して約１μｍエッチングして種膜を除去し多層配線板を作製した。本多層配線板を２００℃のハンダリフロー槽に１０分間、２８８℃ハンダ槽に１分保持したが、樹脂界面、配線の剥離等は生じなかった。
【００５２】
【発明の効果】
本発明によれば、誘電率、誘電正接が低く、ガラス転移温度が高く、引張強度、伸びの大きな硬化物が得られる。本樹脂組成物は、高周波用電気部品の絶縁材料に好適であり、高周波信号用配線基板、及びそれに用いられるプリプレグへの応用が可能である。
【図面の簡単な説明】
【図１】多層配線板作製時のプロセスを現わす模式図である。
【符号の説明】
１…電解銅箔、２…樹脂基板、３…フォトレジスト、４…プリプレグ、５…内層配線、６…外層配線、７…スルーホール、８…めっき触媒、９…種膜、１０…開孔部、１１…電極、１２…めっき銅[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printed wiring board having a small dielectric loss to cope with a high-frequency signal, a laminated board with a conductor, a prepreg, a low dielectric loss tangent resin composition used for producing them, and a cured product thereof.
[0002]
[Prior art]
In recent years, the signal band of information communication devices such as PHS and mobile phones, and the CPU clock time of computers have reached the GHz band, and the frequency has been increased. The dielectric loss of an electrical signal is proportional to the product of the square root of the dielectric constant of the insulator forming the circuit, the dielectric loss tangent and the frequency of the signal used. Therefore, the higher the frequency of the signal used, the greater the dielectric loss. Since the dielectric loss attenuates the electrical signal and impairs the reliability of the signal, in order to suppress this, it is necessary to select a material having a small dielectric constant and dielectric loss tangent for the insulator. Removal of polar groups in the molecular structure is effective for lowering dielectric constant and dielectric loss tangent of insulators. Fluorine resin, curable polyolefin, cyanate ester resin, curable polyphenylene oxide, allyl-modified polyphenylene ether, divinyl A polyetherimide modified with benzene or divinylnaphthalene has been proposed.
[0003]
A fluororesin represented by polytetrafluoroethylene (PTFE) has a low dielectric constant and dielectric loss tangent, and is used as a substrate material for handling high-frequency signals. However, since PTFE is a thermoplastic resin, it has a large expansion / contraction during molding and is difficult to handle. Various proposals for imparting crosslinkability and solubility to fluororesins have also been made, but these materials are generally expensive and many of them do not reach PTFE in terms of characteristics. In contrast, various non-fluorine-based low dielectric constant and low dielectric loss tangent resins that are soluble in organic solvents and easy to handle have been studied. For example, a glass cloth impregnated with a diene polymer such as polybutadiene described in JP-A-8-208856 and cured with a peroxide; as disclosed in JP-A-10-158337, an epoxy group is added to a norbornene-based addition polymer. Example of cyclic polyolefin to which curability has been introduced; cyanate ester, diene polymer and epoxy resin are heated to form B stage as described in JP-A-11-124491; JP-A-9-118759 Examples of modified resins composed of polyphenylene oxide, diene polymer and triallyl isocyanate; Examples of resin compositions composed of allylated polyphenylene ether and triallyl isocyanate described in JP-A-9-246429; described in JP-A-5-156159 Polyetherimide with styrene and dibi An example of alloying rubenzene or divinylnaphthalene; a resin composition comprising, for example, hydroquinone bis (vinylbenzyl) ether and a novolac phenol resin synthesized by a Williamson reaction from a dihydroxy compound described in JP-A-5-78552 and chloromethylstyrene There are many examples. Many of the foregoing examples stated that divinylbenzene may be included as a crosslinking agent or crosslinking aid. This is because divinylbenzene does not have a polar group in the structure, the cured product has a low dielectric constant and dielectric loss tangent, and a high thermal decomposition temperature of 350 ° C. or higher. However, since the divinylbenzene cured product is very brittle, it has a drawback that the cured product is easily cracked during curing. Therefore, the amount of divinylbenzene added is usually set lower than other resin components. Even in the example of JP-A-5-156159 using divinylbenzene as the main crosslinking agent, the addition amount is about 9% of the whole resin. The divinylnaphthalene described in the publication also has the same problem as divinylbenzene in terms of the brittleness of the cured product. Further, since divinylbenzene has volatility, it has a drawback that it is difficult to control the properties of the cured product because it is volatilized during curing. On the other hand, JP-A-5-78552 discloses that bisstyrene compounds such as hydroquinone bis (vinylbenzyl) ether are non-volatile and give a highly flexible cured product. However, in general, an alkylene ether group is disadvantageous in terms of dielectric constant, dielectric loss tangent, and heat resistance as compared with an alkylene group and an arylene group. A hydrocarbon-based skeleton such as an alkylene group or an arylene group is preferable for the structure that bonds styrene groups. Examples of polyfunctional styrene compounds in which styrene groups are bonded with ethylene groups include 1,2-bis (vinylphenyl) ethane described in JP-A-9-208625, Makromol. Chem. vol. 187, page 23 (1986), there is a divinylbenzene oligomer having a vinyl group in the side chain. However, in these reports, the mechanical strength, heat resistance, dielectric constant or dielectric loss tangent has not been studied.
[0004]
[Problems to be solved by the invention]
Conventionally, divinylbenzene, which has been used as a cross-linking agent that can lower the dielectric constant and dielectric loss tangent of a composition containing it, has drawbacks such as volatility and brittleness of the cured product. Was.
An object of the present invention is a resin comprising a crosslinking agent having a low dielectric constant and dielectric loss tangent, non-volatile, excellent in solubility and compatibility with various resins, and having good heat resistance and flexibility after curing. The object is to provide a composition, a cured product thereof, and a prepreg, a laminate and a multilayer printed board using the composition.
[0005]
[Means for Solving the Problems]
The present invention includes the following inventions.
(1) The following general formula:
[Chemical 3]

(Wherein R represents a hydrocarbon skeleton, R ¹ Are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; ² , R ^Three And R ^Four Are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m represents an integer of 1 to 4, and n represents an integer of 2 or more. )
A resin composition containing a cross-linking component having a weight average molecular weight of 1000 or less having a plurality of styrene groups and a high molecular weight material, and obtained by curing the resin composition at 180 ° C. for 100 minutes The resin composition whose glass transition temperature of a thing is 170 degreeC or more, or whose elasticity modulus in 170 degreeC of this hardened | cured material is 500 MPa or more.
(2) The composition according to (1), further including at least one of a curing catalyst capable of polymerizing styrene groups and a polymerization inhibitor capable of suppressing polymerization of styrene groups.
(3) The addition amount of the curing catalyst is 0.0005 to 10 parts by weight and the addition amount of the polymerization inhibitor is 0.0005 to 5 parts by weight with respect to a total of 100 parts by weight of the crosslinking component and the high molecular weight body. The composition according to (2), which is a part.
(4) The composition according to any one of (1) to (3), wherein the glass transition temperature of the high molecular weight material is 170 ° C. or higher.
(5) A polymer, substituent, wherein the high molecular weight substance is at least one of butadiene, isoprene, styrene, methylstyrene, ethylstyrene, divinylbenzene, acrylic ester, acrylonitrile, N-phenylmaleimide and N-vinylphenylmaleimide. The composition according to any one of the above (1) to (4), which is at least one resin selected from the group consisting of a polyphenylene oxide which may have an alicyclic structure and a polyolefin having an alicyclic structure.
(6) The following general formula:
[Formula 4]

(Wherein R represents a hydrocarbon skeleton, R ¹ Are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; ² , R ^Three And R ^Four Are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m represents an integer of 1 to 4, and n represents an integer of 2 or more. )
A cured product obtained by curing a resin composition containing a cross-linking component having a plurality of styrene groups and having a weight average molecular weight of 1,000 or less and a high molecular weight material, and has a glass transition temperature of 170 ° C. or higher. Or a cured product having an elastic modulus at 170 ° C. of 500 MPa or more.
(7) A cured product of the composition according to any one of (1) to (5).
(8) A prepreg obtained by impregnating an organic or inorganic cloth or nonwoven fabric with the composition according to any one of (1) to (5) and drying the composition.
(9) A cured product of the prepreg according to (8).
(10) A laminated board in which a conductor layer is provided on both sides or one side of the prepreg or the cured product thereof according to (8).
(11) A multilayer printed board obtained by performing wiring processing on the conductor layer of the laminated board according to (10) and then laminating and bonding the laminated board via a prepreg.
[0006]
(Action)
As described above, the cured product of divinylbenzene has high heat resistance and low dielectric constant and dielectric loss tangent. According to the present invention, a resin composition containing a cross-linking component of a non-volatile hydrocarbon skeleton having a weight average molecular weight of 1000 or less having a plurality of styrene groups and a high molecular weight material does not crack during curing, and has a dielectric constant and dielectric loss tangent Was found to give a low cured product. Since the styrene groups are bonded with a flexible hydrocarbon skeleton such as an alkylene group, no cracking occurs during curing. Further, a low dielectric loss tangent resin composition having a glass transition temperature after curing of 170 ° C. or higher, or an elastic modulus at 170 ° C. after curing of 500 MPa or higher is processed at a high temperature such as gold wire bonding or soldering. Since the deformation is small in the process, it is suitable as an insulating material for electronic parts such as multichip modules and multilayer printed boards.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The resin composition of the present invention and the cured product thereof will be described.
The resin composition of the present invention has the following general formula:
[Chemical formula 5]

(Wherein R represents a hydrocarbon skeleton, R ¹ Are the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; ² , R ^Three And R ^Four Are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m represents an integer of 1 to 4, and n represents an integer of 2 or more. )
A resin composition containing a cross-linking component having a weight average molecular weight of 1000 or less having a plurality of styrene groups and a high molecular weight material, and obtained by curing the resin composition at 180 ° C. for 100 minutes The glass transition temperature of the product is 170 ° C. or higher, or the cured product is a resin composition having an elastic modulus at 170 ° C. of 500 MPa or higher, and the glass transition temperature of the cured product is 170 to 300 ° C., Or it is preferable that the elasticity modulus in 170 degreeC of this hardened | cured material is 500-3000 MPa.
[0008]
The cured product of the present invention is a cured product obtained by curing a resin composition containing the cross-linking component and a high molecular weight body, and has a glass transition temperature of 170 ° C. or higher, or an elasticity at 170 ° C. It is preferable that the cured product has a modulus of 500 MPa or more and a glass transition temperature of 170 to 300 ° C. or an elastic modulus at 170 ° C. of 500 to 3000 MPa.
[0009]
In the present specification, the glass transition temperature is the peak of tan δ, which is the ratio of the loss elastic modulus to the storage elastic modulus, when dynamic viscoelastic properties are observed at a temperature rising rate of 5 ° C./min. The elastic modulus is an elastic modulus at 170 ° C. measured under the same conditions. By using a printed circuit board that uses a cured product of the resin composition of the present invention as an insulating layer having a low dielectric constant and dielectric loss tangent, a high glass transition temperature, and a high elastic modulus at high temperatures, the dielectric loss of electrical signals can be reduced. It is possible to suppress the deformation in a processing process at a high temperature such as gold wire bonding and soldering.
[0010]
In the above formula, the hydrocarbon skeleton represented by R is not particularly limited as long as the weight average molecular weight of the crosslinking component is 1000 or less. That is, the hydrocarbon skeleton represented by R is a substituent in the styrene group, R ¹ , R ² , R ^Three And R ^Four Although it can select suitably according to the presence or absence and its magnitude | size, and the number of m and n, generally it is C1-C60, Preferably it is C2-C30. The hydrocarbon skeleton represented by R may be linear or branched, and may contain one or more ring structures such as an alicyclic structure and an aromatic ring structure, and further vinylene. And may contain an unsaturated bond such as ethynylene.
[0011]
Examples of the hydrocarbon skeleton represented by R include ethylene, trimethylene, tetramethylene, methyltrimethylene, methyltetramethylene, pentamethylene, methylpentamethylene, cyclopentylene, cyclohexylene, phenylene, phenylenediethylene, xylylene, 1 -Phenylene-3-methylpropenylene and the like.
[0012]
In the above formula, R ¹ The hydrocarbon group represented by the formula is a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl. , Isobutyl, sec-butyl, pentyl, hexyl, decyl, eicosyl; linear or branched alkenyl groups having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, such as vinyl, 1-propenyl, 2- Propenyl, 2-methylallyl; aryl groups such as phenyl, naphthyl, benzyl, phenethyl, styryl, cinnamyl.
[0013]
In the above formula, since n is an integer of 2 or more, R ¹ Are present, and when m is an integer of 2 to 4, R ¹ There are multiple, but such multiple R ¹ May be the same or different, and the bonding position may be the same or different.
In the above formula, R ² , R ^Three Or R ^Four Examples of the alkyl group represented by the formula include linear or branched alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and hexyl.
In the above formula, an optionally substituted vinyl group [(R ^Three ) (R ^Four ) C = C (R ² )-] Is preferably present in the meta or para position relative to R on the benzene ring.
[0014]
The crosslinking component used in the present invention is preferably a polyfunctional monomer having a plurality of (optionally substituted) styrene groups and having a weight average molecular weight of 1000 or less. Styrene groups are highly reactive and have a very low dielectric constant and dielectric loss tangent. It is preferable to adopt a hydrocarbon skeleton as the skeleton of the crosslinking component from the viewpoint of dielectric constant and dielectric loss tangent. This makes it possible to impart non-volatility and flexibility to the crosslinking component without impairing the low dielectric constant and low dielectric loss tangent of the styrene group. In addition, by selecting a crosslinking component having a weight average molecular weight of 1000 or less, melt flowability is exhibited at a relatively low temperature and solubility in an organic solvent is improved, so that molding and varnishing are facilitated. If the weight average molecular weight of the cross-linking component is too large, melt flowability is lowered, and cross-linking may occur during molding processing, resulting in poor molding. Although there will be no restriction | limiting if the weight average molecular weight of this crosslinking component is 1000 or less, Preferably it is 200-500.
[0015]
Preferred examples of the crosslinking component include 1,2-bis (p-vinylphenyl) ethane, 1,2-bis (m-vinylphenyl) ethane, 1- (p-vinylphenyl) -2- (m-vinylphenyl). ) Ethane, 1,4-bis (p-vinylphenylethyl) benzene, 1,4-bis (m-vinylphenylethyl) benzene, 1,3-bis (p-vinylphenylethyl) benzene, 1,3-bis (M-vinylphenylethyl) benzene, 1- (p-vinylphenylethyl) -4- (m-vinylphenylethyl) benzene, 1- (p-vinylphenylethyl) -3- (m-vinylphenylethyl) benzene And a divinylbenzene polymer (oligomer) having a vinyl group in the side chain. Two or more of these crosslinking components can be used in combination.
[0016]
As a method for synthesizing a crosslinking component preferably used in the present invention, a method of coupling halogenoalkylstyrene synthesized by the method described in JP-A-11-60519 with various halides by Grignard reaction, Makromol. Chem. vol. The synthesis method of the divinylbenzene oligomer which has a vinyl group in the side chain of 187 and 23 pages (1986) is mentioned, It is not limited to these. The cross-linking component thus obtained cross-links at a relatively low temperature of 180 ° C. or lower without adding a curing catalyst, and gives a cured product having high heat resistance and low dielectric constant and dielectric loss tangent. However, when the crosslinking component is used alone without being combined with a high molecular weight material, tack-free properties when prepreg is obtained may not be obtained, or sufficient mechanical strength may not be obtained after curing. is there.
[0017]
The present invention is characterized in that the tack-free property and the mechanical strength of the cured product are improved by combining the above-mentioned crosslinking component and high molecular weight substance. The high molecular weight substance used in the present invention is preferably a soluble polymer having a glass transition temperature of 170 ° C. or higher, or an elastic modulus at 170 ° C. of 500 MPa or higher and easily varnished. More preferably, the transition temperature is 170 to 300 ° C, or the elastic modulus at 170 ° C is 500 to 3000 MPa. When the high molecular weight body is curable, the glass transition temperature after curing is preferably 170 ° C or higher, or the elastic modulus at 170 ° C is preferably 500 MPa or higher, and the glass transition temperature after curing is 170 to 300. It is more preferable that the elastic modulus at 150 ° C is 500 to 3000 MPa. Specific examples of such high molecular weight compounds include butadiene, isoprene, styrene, methyl styrene, ethyl styrene, divinyl benzene, acrylate esters (eg, methyl acrylate, butyl acrylate, phenyl acrylate, etc.), acrylonitrile. And a copolymer of a monomer selected from N-phenylmaleimide and N-vinylphenylmaleimide, polyphenylene oxide which may have a substituent, and polyolefin having an alicyclic structure. It is not limited to. Since the crosslinking component used in the present invention is soluble in most organic solvents, it can be mixed with various high molecular weight substances to obtain a uniform varnish. Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbons such as toluene and xylene, amides such as N, N-dimethylformamide and N, N-dimethylacetamide, diethyl Examples include ethers such as ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, tetrahydrofuran and dioxane, and alcohols such as methanol, ethanol and isopropanol. These organic solvents are used alone or in combination of two or more. be able to. Rubber-like components such as butadiene, isoprene and acrylic acid ester impart flexibility and adhesion to the cured product of the resin composition containing the rubber component, and impart smoothness to the coating film. Styrene, ethyl styrene and / or acrylonitrile has a function of improving the heat resistance of the cured product by copolymerizing with the above rubbery component. By using divinylbenzene and / or N-vinylphenylmaleimide, a high molecular weight product having a functional group in the side chain can be synthesized by a known ionic polymerization method. In particular, N-vinylphenylmaleimide can be easily copolymerized with various monomers because only maleimide groups are polymerized by anionic polymerization and only styrene groups are polymerized by cationic polymerization, and the glass transition temperature of the copolymer is high. . In addition, since the high molecular weight body having a functional group in the side chain reacts with the crosslinking component, the resin composition containing the high molecular weight body and the crosslinking component is prevented from phase separation after curing, and a strong cured product is obtained. give. Polyphenylene oxide and polyolefin having an alicyclic structure are heat-resistant polymers, and by being alloyed with the crosslinking component, flexibility and adhesiveness can be imparted to the cured product and its mechanical strength can be improved. These high molecular weight substances may be used alone or in combination. For example, it is preferable to combine polyphenylene oxide and polybutadiene.
[0018]
The composition of the present invention is filled for the purpose of improving the mechanical strength of the cured product, reducing the thermal expansion coefficient, adjusting the dielectric constant, improving the adhesion with the plated wiring by weight reduction or surface roughening, etc. An agent can be added. In order to improve the mechanical strength, it is preferable to add a fibrous filler such as aluminum borate whisker or carbon fiber. In order to reduce the thermal expansion coefficient, it is preferable to fill spherical fillers having different particle diameters such as silicon oxide at a high rate. In adjusting the dielectric constant, it is preferable to increase the dielectric constant by adding titanium oxide having a high dielectric constant or to reduce the dielectric constant by adding a borosilicate glass balloon having a low dielectric constant. For surface roughening, it is preferable to add a filler that is soluble in an alkaline aqueous solution, such as calcium carbonate or magnesium hydroxide. These fillers may be used alone or in combination.
[0019]
The addition amount of the crosslinking component, the high molecular weight body and the filler contained in the resin composition of the present invention is not particularly limited, but the crosslinking component is 5 to 95 parts by weight, the high molecular weight body is 95 to 5 parts by weight, and the filler. Is preferably added in the range of 70 to 5 parts by weight. Within the above composition range, the composition is adjusted according to the purpose such as imparting film formability, improving the strength, reducing the thermal expansion coefficient, adjusting the dielectric constant, improving the adhesion with the plated wiring by weight reduction and surface roughening. Can be adjusted. More preferable composition is 50 to 95 parts by weight of the crosslinking component, 50 to 5 parts by weight of the high molecular weight material, and 70 to 5 parts by weight of the filler, and more preferable composition is 50 to 80 parts by weight of the crosslinking component. The high molecular weight body is 50 to 20 parts by weight, and the filler is 70 to 5 parts by weight, and even when a high molecular weight body having no crosslinkable functional group is used according to this composition range, the solvent resistance of the cured product is also obtained. Is preserved.
[0020]
The resin composition of the present invention can be cured only by heating without adding a curing catalyst, but a curing catalyst capable of polymerizing styrene groups can be added for the purpose of improving the curing efficiency. The addition amount is not particularly limited, but since the residue of the curing catalyst may adversely affect the dielectric properties, 0.0005 to 10 weights with respect to 100 parts by weight of the total of the crosslinking component and the high molecular weight material. It is desirable to be a part. By adding the curing catalyst within the above range, the polymerization reaction of the styrene group is promoted, and a strong cured product can be obtained at a low temperature. Examples of curing catalysts that generate cation or radical active species capable of initiating polymerization of styrene groups by heat or light are shown below. As a cationic polymerization initiator, BF _Four , PF ₆ , AsF ₆ , SbF ₆ Diallyl iodonium salt, triallyl sulfonium salt and aliphatic sulfonium salt, which are used as counter anions, SP-70, 172, CP-66 made by Asahi Denka Kogyo, CI-2855, 2823 made by Nippon Soda, Sanshin Chemical Co., Ltd. Commercial products such as SI-100L and SI-150L can be used. As radical polymerization initiators, benzoin compounds such as benzoin and benzoin methyl, acetophenone compounds such as acetophenone and 2,2-dimethoxy-2-phenylacetophenone, thioxanthone compounds such as thioxanthone and 2,4-diethylthioxanthone Compounds, bisazide compounds such as 4,4′-diazidochalcone, 2,6-bis (4′-azidobenzal) cyclohexanone and 4,4′-diazidobenzophenone, azobisisobutylnitrile, 2,2-azobispropane , Azo compounds such as m, m′-azoxystyrene and hydrazone, and 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di ( t-butylperoxy) hexyne-3, dicumyl peroxy Examples thereof include organic peroxides such as side. In particular, it is desirable to add an organic peroxide or a bisazide compound that can cause hydrogen abstraction of a compound having no functional group and cause crosslinking between the crosslinking component and the high molecular weight substance.
[0021]
A polymerization inhibitor can be added to the resin composition of the present invention in order to increase storage stability. The addition amount is preferably in a range that does not significantly impair the dielectric properties and reactivity at the time of curing, and is 0.0005 to 5 parts by weight with respect to 100 parts by weight of the total of the crosslinking component and the high molecular weight body. It is desirable to do. When the polymerization inhibitor is added within the above range, an excessive crosslinking reaction during storage can be suppressed, and no significant curing failure is caused during curing. Examples of the polymerization inhibitor include quinones such as hydroquinone, p-benzoquinone, chloranil, trimethylquinone, 4-t-butylpyrocatechol, and aromatic diols.
[0022]
The resin composition of the present invention can be used as a prepreg by impregnating an organic or inorganic cloth or nonwoven fabric and drying it. There is no restriction | limiting in particular about the base material of a prepreg, Various glass cloth, a glass nonwoven fabric, an aramid nonwoven fabric, porous PTFE, etc. can be used. The prepreg is produced by immersing a cloth or non-woven fabric serving as a base material in a varnish produced using the resin composition, and then drying the cloth. Although the drying conditions after the impregnation depend on the resin composition, for example, when toluene is used as a solvent, it is preferably dried at 80 to 130 ° C. for about 30 to 90 minutes.
[0023]
By laminating a conductive foil such as an electrolytic copper foil on the prepreg of the present invention and subjecting it to hot pressing, a laminate having a conductive layer on the surface can be produced. The thickness of the copper foil is preferably about 12 to 36 μm. The conditions of the press working depend on the resin composition, but when, for example, cyclic polyolefin is used as the high molecular weight body, it is preferably molded at 120 to 180 ° C. and 1.0 to 5 MPa for 1 to 3 hours.
[0024]
It is also possible to fabricate a multilayer printed circuit board by multilayering the conductor layer of this laminate by wiring by an ordinary etching method, laminating a plurality of the conductor layers through the prepreg, and performing hot pressing. The multilayer printed circuit board obtained in this way has a low dielectric loss tangent, so that the multilayer printed circuit board has a small dielectric loss. Moreover, since the multilayer printed board of the present invention has a high glass transition temperature and a high elastic modulus at high temperatures, it can sufficiently cope with high temperature processing processes such as gold wire bonding and soldering.
[0025]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these. In the following description, “parts” refers to parts by weight unless otherwise specified.
Tables 1 to 3 show the compositions and characteristics of Examples and Comparative Examples of the present invention. The name of the reagent used for the Example and the comparative example, the synthesis method, the preparation method of a varnish, and the evaluation method of hardened | cured material are demonstrated below.
[0026]
(1) Synthesis of 1,2-bis (vinylphenyl) ethane (BVPE)
1,2-bis (vinylphenyl) ethane (BVPE) was synthesized by a known method as shown below. To a 500 ml three-necked flask, 5.36 g (220 mmol) of granular magnesium for Grignard reaction (manufactured by Kanto Kagaku) was taken, and a dropping funnel, a nitrogen introducing tube and a septum cap were attached. The whole system was heated and dehydrated with a dryer while stirring the magnesium particles with a stirrer under a nitrogen stream. 300 ml of dry tetrahydrofuran was taken into a syringe and injected through a septum cap. After cooling the solution to −5 ° C., 30.5 g (200 ml) of vinylbenzyl chloride (VBC, manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over about 4 hours using a dropping funnel. After completion of the dropwise addition, stirring was continued at 0 ° C./20 hours. After completion of the reaction, the reaction solution was filtered to remove residual magnesium and concentrated with an evaporator. The concentrated solution was diluted with hexane, washed once with a 3.6% hydrochloric acid aqueous solution and three times with pure water, and then dehydrated with magnesium sulfate. The dewatered aqueous solution was purified by passing through a short column of silica gel (Wakogel C300 manufactured by Wako Pure Chemical Industries) / hexane and vacuum dried to obtain BVPE. The obtained BVPE was a mixture of mm body (liquid), mp body (liquid), and pp body (crystal), and the yield was 90%. ¹ When the structure was examined by H-NMR, the value agreed with the literature value (6H-vinyl: α-2H, 6.7, β-4H, 5.7, 5.2; 8H-aromatic: 7.1 ~ 7.35; 4H-methylene: 2.9).
This BVPE was used as a crosslinking component.
[0027]
(2) Synthesis of polydivinylbenzene (polyDVB)
Polydivinylbenzene (polyDVB) was synthesized by a known method as shown below. 520 ml of diisopropylamine THF solution (diisopropylamine content 101 g = 1 mol) was put into a 1000 ml three-necked flask purged with nitrogen. 11 ml of n-butyllithium hexane solution (n-butyllithium content 1.9 g = 20 mmol) was added. 140 mmol (18.2 g) of divinylbenzene was added. Stir for 60 minutes at room temperature. Methanol was added to stop the reaction. The reaction solution was concentrated with an evaporator, then reprecipitated with cold methanol and dried to obtain polydivinylbenzene. The yield was about 50% and the molecular weight was about 20000. Polydivinylbenzene was soluble and had a vinyl group in the side chain (4H-aromatic: 6.5-7.2; 3H-vinyl: 5-6.5; 3H-methylene, methine: 1- 2). This polydivinylbenzene was used as a crosslinking component of Comparative Example 5.
[0028]
(3) Other reagents
Other high molecular weight materials and cross-linking components shown below were used.
High molecular weight body;
Zeonor: manufactured by ZEON Corporation, cyclic polyolefin (Zeonor1600R) PPE: manufactured by Aldrich, poly-2,6-dimethyl-1,4-phenylene oxide
The crosslinking component of Comparative Example 4;
DVB: Wako Pure Chemicals, divinylbenzene
Curing catalyst;
25B: 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 (perhexine 25B) manufactured by NOF Corporation
Organic nonwoven fabric;
Kuraray Vectran K-9
Dupont surmount E210
Glass cloth;
Nittobo # 2116
[0029]
(4) Preparation method of varnish
A varnish of a resin composition was prepared by dissolving a predetermined amount of a high molecular weight substance, a crosslinking component, and a curing catalyst in chloroform or carbon disulfide.
[0030]
(5) Production of resin plate
After the varnish is applied to a PET film and dried, the varnish is peeled off and put into a Teflon spacer, and a predetermined amount is put into a spacer made of Teflon, and heated and pressed under vacuum through a polyimide film and an end plate to form a resin plate as a cured product Got. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and multistage heating with a press pressure of 1.5 MPa. The size of the resin plate was 70 × 70 × 1 mm.
[0031]
(6) Preparation of prepreg
All the prepregs produced in the examples were produced by impregnating a predetermined organic nonwoven fabric or glass cloth with a varnish of the resin composition and drying at room temperature for about 1 hour and at 90 ° C. for 60 minutes. Table 3 shows the names of the base materials used and the resin content (contents of the high molecular weight body and the crosslinking component).
[0032]
(7) Preparation of cured prepreg
In order to know the characteristics of the prepreg when it was made into a laminate, the simulated prepreg was prepared by heating and pressing the prepreg produced by the above method under vacuum. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and multistage heating with a press pressure of 1.5 MPa. The simulated substrate was 70 × 70 × 0.14-0.3 mm.
[0033]
(8) Measurement of dielectric constant and dissipation factor
The values of dielectric constant and dielectric loss tangent were measured at 10 GHz by a cavity resonance method (Agilent Technologies 8722ES network analyzer, Kanto Electronics Application Development cavity resonator).
[0034]
(9) Measurement of tensile strength and elongation
Tensile strength and elongation were measured using a Shimadzu AGS-100 type tensile tester, using a columnar sample having a thickness of 1 mm, a width of 1 mm, and a length of 70 mm, at room temperature, a distance between fulcrums of 20 mm, and a tensile speed of 10 mm / min. .
[0035]
(10) Glass transition temperature (Tg), elastic modulus
Tg and elastic modulus were obtained by observing the elastic modulus at 170 ° C. at the peak position of tan δ using a DVA-200 viscoelasticity measuring device (DMA) manufactured by IT Measurement Control. The sample shape and the distance between the fulcrums were the same as those of the sample for tensile strength, and the heating rate was 5 ° C./min.
[0036]
(11) Peel strength
A sample for measuring the peel strength was prepared by forming each resin composition on a rough surface of an electrolytic copper foil (18 μm) by forming a resin layer under the same conditions as in the resin plate manufacturing method. The resin layer had a thickness of 2 mm and a size of 70 × 70 mm. The electrolytic copper foil on the resin layer was cut into a width of 10 mm, and the peel strength was measured.
[0037]
[Comparative Example 1]
Comparative Example 1 is an example of a resin composition composed only of a cyclic polyolefin resin Zeonor as a high molecular weight body. A cured product of this composition was prepared as a resin plate by placing a predetermined amount of pellets in a metal spacer and heating and pressing under vacuum through a polyimide film and a mirror plate. The heating conditions were 260 ° C./30 minutes and a press pressure of 1.5 MPa. The resin plate was 70 × 70 × 1 mm. This resin plate has a dielectric constant of 2.20 and a dielectric loss tangent of 0.0007, both of which are very low, a Tg of 185 ° C., and an elastic modulus of 1190 MPa, both of which are high. However, since this resin does not have curability, it swells in an organic solvent. Moreover, the heating temperature at the time of shaping | molding needed about 260 degreeC.
[0038]
[Comparative Example 2]
The comparative example 2 is an example of the resin composition which consists only of PPE as a high molecular weight body.
A cured product of this composition was prepared as a resin plate by placing a predetermined amount of resin powder in a metal spacer and heating and pressing under vacuum through a polyimide film and an end plate. The heating conditions were 320 ° C./30 minutes and the press pressure was 1.5 MPa. The resin plate was 70 × 70 × 1 mm. This resin plate has a very low dielectric constant of 2.41 and a dielectric loss tangent of 0.0022, a Tg of 229 ° C., and an elastic modulus of 2000 MPa. However, since this resin does not have curability, it swells in an organic solvent. Further, the molding temperature was required to be about 320 ° C.
[0039]
[Comparative Example 3]
Comparative Example 3 is an example of a resin composition containing 1 wt% of a curing catalyst 25B based on the weight of the crosslinking component 1,2-bis (vinylphenyl) ethane (BVPE) and BVPE. A cured product of this composition was prepared as a resin plate by injecting the resin composition in a solvent-free state between two glass plates attached with a Teflon spacer, sealing, and curing by heating. The heating conditions were multistage heating at 120 ° C./30 minutes, 150 ° C./30 minutes, and 180 ° C./100 minutes. The resin plate was 70 × 70 × 1 mm. The produced resin plate has a dielectric constant as low as 2.56, a dielectric loss tangent as low as 0.0017, a Tg of 400 ° C. or higher, and an elastic modulus as high as 2590 MPa. Excellent solvent resistance due to its curability. The curing temperature is relatively low at 180 ° C. However, there is a problem in that the tensile strength is 31.2 MPa and the elongation is as small as 2%.
[0040]
[Examples 1 to 3]
Examples 1-3 include a resin composition comprising Zeonor as a high molecular weight substance and BVPE as a crosslinking component in different blending ratios, and further containing 1 wt% of a curing catalyst 25B with respect to the weight of the resin component. It is an example. Cured products of these compositions were prepared as resin plates by preparing varnishes using sulfur disulfide as a solvent and by the method described above.
As is clear from each example, the dielectric constant and dielectric loss tangent of each resin plate were very low, the dielectric constant was 2.27 to 2.35, and the dielectric loss tangent was 0.0013 to 0.0017. The other characteristics reflect the characteristics of the added high molecular weight body, with a tensile strength of 68 to 79 MPa, an elongation of 21 to 28%, a Tg of 178 to 183 ° C., an elastic modulus of 1000 to 1130 MPa, and a peel strength of 0.7 to An excellent value of 1.2 N / m was exhibited. Since this resin composition has curability, it has excellent solvent resistance. The molding temperature was 180 ° C., and molding at a low temperature was possible.
[0041]
[Examples 4 to 6]
Examples 4 to 6 include a resin composition comprising PPE as a high molecular weight substance and BVPE as a crosslinking component in different blending ratios, and further containing 1 wt% of a curing catalyst 25B based on the weight of the resin component. It is an example. Cured products of these resin compositions were prepared as resin plates by preparing varnishes using chloroform as a solvent and by the method described above.
As is clear from each example, the dielectric constant and dielectric loss tangent of the resin composition were very low, the dielectric constant was 2.43 to 2.45, and the dielectric loss tangent was 0.0017 to 0.0019. The other characteristics reflect the characteristics of the added high molecular weight, and the tensile strength is 63 to 82 MPa, the elongation is 26 to 47%, the Tg is 210 to 225 ° C., the elastic modulus is 2470 to 2530 MPa, and the peel strength is 0.7 to An excellent value of 1.2 N / m was exhibited.
Since this resin composition has curability, it is excellent also in solvent resistance. The molding temperature was 180 ° C., and molding at a low temperature was possible.
The results of Comparative Examples 1-3 and Examples 1-6 are shown in Table 1 below;
[0042]
[Table 1]

[0043]
[Comparative Example 4]
Comparative Example 4 is an example of a resin composition that contains 1 wt% of the curing catalyst 25B with respect to the weight of DVB and DVB, but does not contain a high molecular weight substance. The cured product of this composition was prepared as a resin plate by the above-described method without using a solvent. This resin plate was very brittle and cracked during curing and cooling, and could not be evaluated.
[0044]
[Comparative Example 5]
Comparative Example 5 is an example of a resin composition containing 50 parts by weight of PolyDVB having a molecular weight of about 20000 as a crosslinking component and 50 parts by weight of PPE as a high molecular weight, and further containing 1 wt% of a curing catalyst 25B based on the weight of the resin component. It is. The cured product of this composition was prepared as a resin plate by preparing varnish using chloroform as a solvent and by the method described above. Since this resin plate has a high molecular weight of the cross-linking agent, it was confirmed that the melt fluidity was insufficient and a molded plate could not be produced.
[0045]
[Comparative Example 6]
Comparative Example 6 is an example of a resin composition containing 50 parts by weight of PPE as a high molecular weight body and 50 parts by weight of BVPE as a crosslinking component, and further containing a curing catalyst in excess of 20 wt% with respect to the total weight of the resin components. is there. The cured product of this composition was prepared as a resin plate by preparing varnish using chloroform as a solvent and by the method described above. In this resin plate, since the curing catalyst was excessively added, the dielectric constant increased to 2.6 and the dielectric loss tangent increased to 0.003. Further, since the curing speed was high, the fluidity at the time of molding was lowered, and the shape and thickness of the resin plate became non-uniform.
[0046]
[Examples 7 and 8]
Examples 7 and 8 are resin compositions comprising 50 parts by weight of PPE as a high molecular weight material and 50 parts by weight of BVPE as a crosslinking component, and further containing 10 wt% or 5 wt% of a curing catalyst 25B, respectively, based on the weight of the resin component. It is an example. The cured product of this composition was prepared as a resin plate by preparing varnish using chloroform as a solvent and by the method described above. If this resin plate has a curing catalyst amount of 10 wt% or less, molding defects do not occur. Further, the dielectric constant was 2.43 and the dielectric loss tangent was 0.0018 to 0.0019, and no significant deterioration in the characteristics was observed.
The results of Comparative Examples 4-6 and Examples 7-8 are shown in Table 2 below;
[0047]
[Table 2]

[0048]
[Examples 9 to 11]
Table 3 shows the configuration and dielectric properties of prepregs prepared by impregnating various base materials into the resin composition of the present invention. All the prepared prepregs have tack-free properties. For the preparation of the prepreg, 50 parts by weight of the resin composition prepared in Example 5, that is, PPE as a high molecular weight body and BVPE as a crosslinking component, and 1 wt% of the curing catalyst 25B with respect to the weight of the resin component were used. The resin composition comprising was used. The prepreg was prepared by preparing varnish using chloroform as an organic solvent, impregnating the varnish with a predetermined organic nonwoven fabric or glass cloth, and drying at room temperature for about 1 hour and at 90 ° C. for 60 minutes. Table 3 shows the name of each substrate and the resin content. The prepreg produced as described above was cured by heating and pressing under vacuum to produce a simulated substrate. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and multistage heating with a press pressure of 1.5 MPa. The simulated substrate was 70 × 70 × 0.14-0.3 mm. The simulated substrate of Example 9 using glass cloth (# 2116) as a base material has a dielectric constant of 3.12, a dielectric loss tangent of 0.0038, and a simulated base material of Example 10 using an organic nonwoven fabric (K-9) as a base material. The substrate had a dielectric constant of 2.51, a dielectric loss tangent of 0.0027, and the simulated substrate of Example 11 based on E210 had a dielectric constant of 2.61 and a dielectric loss tangent of 0.0024. Both have good dielectric properties.
The results of Examples 9-11 are shown in Table 3 below;
[0049]
[Table 3]

[0050]
[Example 12]
The rough surface of the electrolytic copper foil was pasted on both surfaces of the prepreg produced in Example 9, and pressure and heating were performed under vacuum to produce a double-sided copper-clad laminate. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and a press pressure of 1.5 MPa. The copper foil and prepreg showed good adhesion. This made it possible to produce a multilayer printed circuit board.
[0051]
[Example 13]
An example of producing the multilayer printed board of the present invention is shown below. (A) A photoresist (HS425 manufactured by Hitachi Chemical Co., Ltd.) was laminated on one side of the double-sided copper clad laminate obtained in Example 12, and the entire surface was exposed. Next, a photoresist (HS425 manufactured by Hitachi Chemical Co., Ltd.) was laminated on the remaining copper surface to expose the test pattern, and the unexposed photoresist was developed with 1% sodium carbonate solution. (B) The copper foil exposed with an etching solution of 5% sulfuric acid and 5% hydrogen peroxide was removed by etching to form a conductor wiring on one side of the double-sided copper-clad laminate. (C) The remaining photoresist was removed with a 3% sodium hydroxide solution to obtain a wiring board having wiring on one side. Similarly, two wiring boards were produced. (D) The prepreg of Example 9 was sandwiched between the wiring-side surfaces of the two wiring boards, and heated and pressed under vacuum to form a multilayer. The heating conditions were 120 ° C./30 minutes, 150 ° C./30 minutes, 180 ° C./100 minutes, and multistage heating with a press pressure of 1.5 MPa. (E) A photoresist (HS425 manufactured by Hitachi Chemical Co., Ltd.) was laminated on the exterior copper on both sides of the produced multilayer board to expose the test pattern, and the unexposed photoresist was developed with 1% sodium carbonate solution. (F) The exposed copper foil was etched away with an etching solution of 5% sulfuric acid and 5% hydrogen peroxide, and the remaining photoresist was removed with a 3% sodium hydroxide solution to form an exterior wiring. (G) A through-hole connecting the inner layer wiring and the outer wiring was formed by drilling. (H) The wiring board was immersed in a colloidal solution of a plating catalyst, and the catalyst was applied to the substrate surface in the through hole. (I) After the activation treatment of the plating catalyst, a seed film of about 1 μm was provided by electroless plating (CUST2000 manufactured by Hitachi Chemical). (J) A photoresist (HN920 manufactured by Hitachi Chemical Co., Ltd.) was laminated on both sides of the wiring board. (K) The through-hole part and the edge part of the wiring board were masked and exposed, and then developed with 3% sodium carbonate to provide an opening part. (L) An electrode was placed on the end of the wiring board, and plated copper was formed in the through portion by about 18 μm by electrolytic plating. (M) The electrode portion was cut and removed, and the remaining photoresist was removed with a 5% aqueous sodium hydroxide solution. (N) The wiring board was immersed in an etching solution of 5% sulfuric acid and 5% hydrogen peroxide, and etched by about 1 μm to remove the seed film, thereby producing a multilayer wiring board. This multilayer wiring board was held in a solder reflow bath at 200 ° C. for 10 minutes and in a 288 ° C. solder bath for 1 minute, but no resin interface, wiring peeling, etc. occurred.
[0052]
【The invention's effect】
According to the present invention, a cured product having a low dielectric constant and dielectric loss tangent, a high glass transition temperature, and a high tensile strength and elongation can be obtained. This resin composition is suitable as an insulating material for high-frequency electrical components, and can be applied to high-frequency signal wiring boards and prepregs used therefor.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a process for producing a multilayer wiring board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electrolytic copper foil, 2 ... Resin substrate, 3 ... Photoresist, 4 ... Prepreg, 5 ... Inner layer wiring, 6 ... Outer layer wiring, 7 ... Through hole, 8 ... Plating catalyst, 9 ... Seed film, 10 ... Opening part 11 ... electrodes, 12 ... plated copper

Claims (6)

The following general formula:

(In the formula, R represents a hydrocarbon skeleton, R ¹ is the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ² , R ³ and R ⁴ are the same or different. Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m represents an integer of 1 to 4, and n represents an integer of 2 or more.)
A cross-linking component having a weight average molecular weight of 1000 or less having a plurality of styrene groups represented by:
High molecular weight ,
A resin composition containing 0.0005 to 10 parts by weight of a curing catalyst capable of polymerizing styrene groups with respect to a total of 100 parts by weight of the crosslinking component and the high molecular weight body ,
A resin characterized in that the high molecular weight material contains at least one resin selected from polyphenylene oxide or polyolefin having an alicyclic structure, and has a glass transition temperature of 170 ° C. or higher or an elastic modulus at 170 ° C. of 500 MPa or higher. Composition. A cured product of the composition according to claim 1. A prepreg obtained by impregnating an organic or inorganic cloth or nonwoven fabric with the composition according to claim 1 and drying the composition. A cured product of the prepreg according to claim 3 . The laminated board by which a conductor layer is installed in the both surfaces or single side | surface of the hardened | cured material of the prepreg of Claim 4 . A multilayer printed board obtained by performing wiring processing on the conductor layer of the laminated board according to claim 5 and then laminating and bonding the laminated board via a prepreg.

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