JP2004002653A

JP2004002653A - Prepreg for printed circuit board and method for manufacturing the same, and printed circuit board

Info

Publication number: JP2004002653A
Application number: JP2002334275A
Authority: JP
Inventors: Naoya Kitamura; 北村　直也; Koichi Hiraoka; 平岡　宏一; Shigeru Kurumaya; 車谷　茂; Masayuki Noda; 野田　雅之
Original assignee: Shin Kobe Electric Machinery Co Ltd
Current assignee: Resonac Corp
Priority date: 2002-04-22
Filing date: 2002-11-18
Publication date: 2004-01-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prepreg useful in the manufacturing of a multilayer printed circuit board, low in dielectric constant and in dielectric loss tangent at high frequencies, high in processability, hardly causing powders to fall, and highly resistant to soldering heat after moisture absorption. <P>SOLUTION: The prepreg is prepared by having a woven or nonwoven fabric, which contains liquid crystal polymer fibers as the constituent strands, carry a thermosetting resin composition whose molecule contains a cyanate compound having one or more cyanates but not an imide compound having more than one imide group. The thermosetting resin composition is low in dielectric constant and in dielectric loss tangent, high in flexibility, and may contain an additional resin component which is low in water absorption rate. It may also contain an inorganic filler which is not detrimental to the low dielectric constant/low dielectric loss tangent feature. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、高周波帯域での誘電率、誘電正接が低く、半田耐熱性に優れたプリント基板に有用なプリプレグ及びプリプレグの製造法、ならびに前記プリプレグを用いたプリント基板乃至多層プリント基板に関する。
【０００２】
【従来の技術】
近年、通信機器、コンピュータには、動作環境の高周波化への対応が求められ、これらに搭載される基板材料にはより一層の低誘電率化、低誘電正接化が望まれている。従来、このような要求に対し、テフロン（登録商標）に代表されるフッ素樹脂やポリフェニレンエーテル等の熱可塑性樹脂が多用されてきたが、高コスト、高温・高圧成形プロセス、寸法安定性の悪さ、低強度、めっきに対する低密着性等の問題点があった。
【０００３】
そこで、シアン酸エステルを主成分とするＢＴレジン（ビスマレイミド−トリアジンレジン）や熱硬化性のポリフェニレンエーテルに代表される熱硬化性樹脂をガラス織布に含浸させた材料も重用されるようになった（例えば、特許文献１、特許文献２）が、加工時の脆さ、樹脂とガラス織布の密着性の低さ、吸湿時の耐熱性に問題があった。加工時の脆さ、ガラス織布との密着性の低さは、ドリル加工によるスルーホール形成時に問題となっている。スルーホール開口部のクラックやスルーホール内壁面の樹脂とガラス織布間の剥離が絶縁信頼性を低下させ、スルーホール内壁の粗さがめっき付き回り性を阻害したり、接続信頼性を低下させていた。
【０００４】
また、ビルドアップ基板の製造においては、レーザによるガラス織布の加工のし難さが加工孔壁にガラス繊維を突出させたまま残す結果となり、ビア形状を不正なものにし、層間の接続信頼性を損なっていた。さらには、プリプレグから樹脂成分やガラス成分が脱落しやすく（いわゆる「粉落ち」）、これらが、プレス成形時に銅箔表面に除去不能となって残ったり、打痕を形成し、また、搭載製品の誤作動を引き起こしたりしていた。一方、ガラス織布を使わない材料として、アラミド繊維の不織布にエポキシ樹脂を含浸させた材料（例えば、特許文献３）が、ガラスを使わない点で低誘電率であり、ドリル・レーザ加工性にも優れているが、アラミド繊維の吸湿性のため、吸湿耐熱性はむしろ低下しており、さらに、誘電正接もガラス織布を使用した材料にに比べ上昇した。また、外形加工の悪さについての問題が残り、基板端面からのアラミド繊維毛羽立ちを抑えるためにルータ加工をしなければならなかった。
【０００５】
【特許文献１】
特開２０００−０３６６６６号公報（請求項６）
【特許文献２】
特開２００１−２６１７９１号公報
【特許文献３】
特開２００２−００３６２６号公報
【０００６】
【発明が解決しようとする課題】
本発明が解決しようとする課題は、以上のような従来技術に鑑み、高周波帯域での誘電率、誘電正接が低く、加工性が良く、粉落ちしにくく、吸湿時の半田耐熱性に優れるプリント基板に有用なプリプレグを提供することである。また、前記プリプレグの製造法ならび当該プリプレグを用いたプリント基板乃至多層プリント基板を提供することである。
【０００７】
【課題を解決するための手段】
上記課題を解決するために、本発明に係る第１のプリプレグは、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物を含み、且つ、分子内に１個以上のイミド基を含有するイミド化合物を含まない熱硬化性樹脂組成物を、液晶ポリマ繊維を構成繊維として含む織布又は不織布に保持させたことを特徴とする。本発明に係るプリント基板は、当該プリプレグの層を加熱加圧成形してなる絶縁層を備えることを特徴とする。このプリント基板は、絶縁層の外層にプリント配線を配置したプリント基板のほか、内層にも絶縁層を介してプリント配線を配置した多層プリント基板を、その概念に含む。
【０００８】
分子内に１個以上のシアン酸エステル基を含有するシアネート化合物は、所定の温度で加熱することにより三量化して、低誘電率、低誘電正接のトリアジン構造を構築して硬化する。液晶ポリマとしては、特に制限はないが、芳香族ジオールと芳香族ジカルボン酸を重縮合させた構造が望ましく、パラヒドロキシ安息香酸と２−ヒドロキシ−６−ナフトエ酸の重縮合ポリマ等は好適で、特に高周波帯域で低誘電率、低誘電正接を示し、各種加工がしやすく、粉落ちも低減でき、吸水率も低く、半田耐熱性に優れる。液晶ポリマ繊維を構成繊維として含む不織布は、不織布化に際して、バインダ、パルプ類を使用しても差し支えない。
【０００９】
上記の織布又は不織布と熱硬化性樹脂組成物の組合せにより本発明の課題を達成できるわけであるが、熱硬化性樹脂組成物には、さらに、ポリフェニレンエーテル、熱硬化性ポリフェニレンエーテル、ポリスチレン、ポリプロピレン、ポリエチレン、ジシクロペンタジエン樹脂、ジシクロペンタジエン構造をもつフェノール化合物、ジシクロペンタジエン構造をもつエポキシ樹脂、環化ポリブタジエン構造をもつフェノール樹脂、環化ポリブタジエン構造をもつエポキシ樹脂、ラダーシリコーン構造をもつオリゴマ、ラダーシリコーン構造をもつポリマ、シルセスキオキサン構造をもつオリゴマ、シルセスキオキサン構造をもつポリマからなる追加樹脂成分群から選ばれる成分を含むことも好ましい。このような極性基が少なく、可撓性に富む構造を導入することにより、誘電特性と加工性、耐粉落ち性、半田耐熱性のより一層の向上が図れる。このような追加樹脂成分群から選ばれる成分は、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物１００質量部に対し、５〜４０質量部配合することが望ましい。追加樹脂成分群から選ばれる成分は、１種であっても２種以上の組合せであってもよい。
【００１０】
上記熱硬化性樹脂組成物には、溶融シリカ、焼成シリカ、中空シリカ、ホウ酸マグネシウム、ケイ酸カルシウム、窒化ホウ素、アルミナからなる充填材群から選ばれる充填材を含むことも好ましい。前記充填材を含むことにより、加工性、特に、打抜き性、半田耐熱性の向上が図れる。このような充填材群から選ばれる充填材は、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物１００質量部に対し、５〜１９００質量部配合することが望ましい。充填材群から選ばれる充填材は、１種であっても２種以上の組合せであってもよい。
【００１１】
液晶ポリマ繊維を構成繊維として含む織布又は不織布は、他の構成繊維として、芳香族ポリアミド繊維、ガラス繊維の少なくとも一方を含むことができる。芳香族ポリアミド繊維を含ませることにより機械的強度の向上が図れ、ガラス繊維を含ませることによりコストダウンが可能である。これらの場合、織布又は不織布を構成する全繊維に占める液晶ポリマ繊維の量は、２５体積％以上であることが望ましい。
【００１２】
本発明に係るプリプレグは、良溶媒となる適当な有機溶剤中に上記の熱硬化性樹脂組成物を樹脂成分が４０〜６０質量％となるように溶解してワニスを調製し、液晶ポリマ繊維を構成繊維として含む織布又は不織布に前記ワニスを含浸させ、１４０〜１６０℃の温度で、６〜１０分間、加熱乾燥して、樹脂成分をＢ−ステージ化することにより製造できる。
【００１３】
本発明に係る第２のプリプレグは、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物と臭素化フェノールを含み、且つ、分子内に１個以上のイミド基を含有するイミド化合物を含まない熱硬化性樹脂組成物を、アラミド繊維を構成繊維として含む織布又は不織布に保持させたことを特徴とする。プリント基板は、当該プリプレグの層を加熱加圧成形してなる絶縁層を備えたものである。このプリント基板は、絶縁層の外層にプリント配線を配置したプリント基板のほか、内層にも絶縁層を介してプリント配線を配置した多層プリント基板を、その概念に含む。
【００１４】
これにより、これら化合物本来の低誘電率、低誘電正接性や可撓性が加味されるだけでなく、シアン酸エステル基を含有するシアネート化合物が硬化する際に発生する極性の高い未反応シアン酸エステル基をフェノール性水酸基と反応させて誘電率、誘電正接の上昇を防ぐことができる。加えて、難燃性の向上も可能である。
【００１５】
上記の臭素化フェノールは、好ましくは、主鎖の片末端に水酸基を有する臭素化ポリフェニレンエーテル、ポリｐ−ビニルフェノールの臭素化物又はｐ−ビニルフェノールとスチレンの共重合体の臭素化物から選ばれる少なくとも１種の樹脂である。
臭素化フェノールとして特に好ましいのは、主鎖の片末端に水酸基を有する臭素化ポリフェニレンエーテルである。当該臭素化ポリフェニレンエーテルは、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物１００質量部に対し３０〜３００質量部配合することが望ましい。
一方、臭素化フェノールとして、ポリｐ−ビニルフェノールの臭素化物やｐ−ビニルフェノールとスチレンの共重合体の臭素化物を選択する場合は、これらが、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物１００質量部に対し０．３〜３０質量部であることが望ましい。
【００１６】
第２のプリプレグにおいても、第１のプリプレグと同様、上述した充填材群から選ばれる充填材を上述した量と同様の量で熱硬化性樹脂組成物に配合することが望ましい。
【００１７】
第２のプリプレグにおいて、アラミド繊維を構成繊維として含む織布又は不織布は、他の構成繊維として、液晶ポリマ繊維、ガラス繊維の少なくとも一方を含むことができる。これらの場合、織布又は不織布を構成する全繊維に占めるアラミド繊維の量は、２５体積％以上であることが望ましい。
【００１８】
第２のプリプレグは、良溶媒となる適当な有機溶剤中に上記の熱硬化性樹脂組成物を樹脂成分が２０〜８０質量％となるよう溶解してワニスを調製し、アラミド繊維を構成繊維として含む織布又は不織布に前記ワニスを含浸させ、１４０〜１６０℃の温度で、６〜１０分間、加熱乾燥して、樹脂成分をＢ−ステージ化することにより製造できる。
【００１９】
以上のようにすることにより、高周波帯域での誘電率、誘電正接が低く、加工性が良く、粉落ちしにくく、吸湿時の半田耐熱性に優れるプリント基板に有用なプリプレグを提供することができる。
【００２０】
【発明の実施の形態】
実施例１
２，２’−ビス（４−シアナトフェニル）プロパン（三菱瓦斯化学製「スカイレックスＣＡ２００」）のオリゴマ（数平均分子量２５００）１０００ｇとその重合触媒であるナフテン酸コバルト０．６ｇ、ポリフェニレンエーテル３００ｇ、難燃剤としてヘキサブロモシクロドデカン１５０ｇを、メチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１０００ｍｌに溶解させて調製したワニスを、液晶ポリマ繊維（クラレ製「ベクトラン」）から乾式法により製造された厚さ７０μｍの不織布（クラレ製「ベクルス」，坪量３９．５ｇ／ｍ^２）に含浸し、１４５℃で７分間乾燥して、樹脂量７０質量％のプリプレグを得た。
【００２１】
実施例２
２，２’−ジ（４−シアナトフェニル）ヘキサフルオロプロパン（旭チバ製「ＡＲＯＣＹ　Ｆ−１０」）のオリゴマ（数平均分子量３０００）５００ｇ、触媒ナフテン酸マンガン０．７ｇ、ジシクロペンタジエン構造をもつフェノール化合物として脂環式変性フェノール樹脂（日本石油化学製「ＤＰＰ−３Ｈ」）５０ｇ、難燃剤テトラブロモシクロオクタン１５０ｇを、メチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１３００ｍｌに溶解させて調製したワニスを、液晶ポリマ繊維（クラレ製「ベクトラン」）から乾式法により製造された厚さ５０μｍの不織布（クラレ製「ベクルス」，坪量３２．４ｇ／ｍ^２）に含浸し、１４５℃で５分間乾燥して、樹脂量６８質量％のプリプレグを得た。
【００２２】
実施例３
脂環式変性フェノール樹脂のシアネート化物（ダウケミカル製「ＱＵＡＴＲＥＸ７１８７」）７００ｇ、触媒ナフテン酸銅０．４ｇ、環化ポリブタジエン構造をもつフェノール化合物として脂環式変性フェノール樹脂（日本石油化学製「ＰＰ−１０００−１８０」）１８０ｇ、難燃剤１，２−ジブロモ−４−（１，２−ジブロモエチル）シクロヘキサン１５０ｇを、メチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１０００ｍｌに溶解させて調製したワニスを、以下に示す湿式法で作製した不織布に含浸し、１４５℃で４分間乾燥して、樹脂量６５質量％のプリプレグを得た。
ここで、不織布は、液晶ポリマ繊維（クラレ製「ベクトラン」）５０体積％と芳香族ポリアミド繊維（帝人製「テクノーラ」）５０体積％を混抄し、樹脂バインダとして水溶性エポキシ樹脂を固形分で１０質量％含むようにスプレーして加熱乾燥により単位質量５６ｇ／ｍ^２のものを抄造し、線圧力２００ｋｇ／ｃｍ，温度３００℃の一対の熱ロールの間に通すことにより加熱圧縮して液晶ポリマ繊維を熱融着ないし変形させて作製した。熱ロールの間に通す混抄不織布の移動速度は１０ｍ／分に設定した。
【００２３】
実施例４
２，２’−ビス（４−シアナトフェニル）プロパン（旭チバ製「ＡＲＯＣＹ　Ｂ−１０」）のオリゴマ（数平均分子量２０００）８００ｇ、触媒オクチル酸亜鉛０．３ｇ、ジシクロペンタジエン樹脂（日本ゼオン製「ＸＥＯＮＥＸ４８０」）２３０ｇ、難燃剤臭素化トリフェニルシアヌレート１５０ｇを、メチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１２００ｍｌに溶解させて調製したワニスを、液晶ポリマ繊維（クラレ製「ベクトラン」）から乾式法により製造された厚さ７０μｍの不織布（クラレ製「ベクルス」，坪量３９．５ｇ／ｍ^２）に含浸し、１４５℃で７分乾燥して、樹脂量７０質量％のプリプレグを得た。
【００２４】
実施例５
脂環式変性フェノール樹脂のシアネート化物（ダウケミカル製「ＱＵＡＴＲＥＸ７１８７」）８００ｇ、触媒ナフテン酸鉄０．４ｇ、ポリスチレンをマトリクス樹脂にしたホウ酸マグネシウムとの複合材料（大塚化学製「テラウエイブＳＭ−６Ｎ」７００ｇ、難燃剤臭素化トリフェニルシアヌレート１３０ｇを、メチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１０００ｍｌに溶解させて調製したワニスを、以下に示す湿式法で作製した不織布に含浸し、１４５℃で３分間乾燥して、樹脂量７８質量％のプリプレグを得た。ここで、不織布は、液晶ポリマ繊維（クラレ製「ベクトラン」）３０体積％とガラス繊維７０体積％を混抄し、樹脂バインダとして水溶性エポキシ樹脂を固形分で８質量％含むようにスプレーして加熱乾燥により単位質量２８ｇ／ｍ^２のものを抄造し、線圧力１００ｋｇ／ｃｍ，温度３００℃の一対の熱ロールの間に通すことにより加熱圧縮して液晶ポリマ繊維を熱融着ないし変形させて作製した。熱ロールの間に通す混抄不織布の移動速度は１０ｍ／分に設定した。
【００２５】
実施例６
２，２’−ビス（４−シアナトフェニル）プロパン（旭チバ製「ＡＲＯＣＹ　Ｂ−１０」）のオリゴマ（数平均分子量２０００）８００ｇ、触媒オクチル酸コバルト０．５ｇ、シルセスキオキサン構造をもつオリゴマとして１−（４−ビニルフェニル）−３，５，７，９，１１，１３，１５−ヘプタシクロペンチルペンタシクロ−［９．５．１．１．１．１］−オクタシロキサン（アルドリッチ製）５０ｇ、難燃剤として臭素化トリフェニルシアヌレート１００ｇをメチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１０００ｍｌに溶解させて調製したワニスを、液晶ポリマ繊維（クラレ製「ベクトラン」）から乾式法により製造された厚さ７０μｍの不織布（クラレ製「ベクルス」，坪量３９．５ｇ／ｍ^２）に含浸し、１４５℃で７分間乾燥して、樹脂量６３質量％のプリプレグを得た。
【００２６】
実施例７〜１１
実施例１のワニスに、表１に示す各種充填材を同表に示す量で配合したワニスを調製し、このワニスを用いて実施例１と同様にプリプレグを作製した。
【００２７】
【表１】

【００２８】
実施例１２
２，２’−ビス（４−シアネートフェニル）プロパン（ロンザ製「ＰＲＩＭＡＳＥＴ　ＢＡＤＣｙ」）のオリゴマ（数平均分子量３０００）１０００ｇとその重合触媒であるナフテン酸コバルト０．６ｇ、臭素化ポリフェニレンエーテル２５００ｇをメチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒２０００ｍｌに溶解させて調製したワニスを、アラミド繊維（帝人製「テクノーラ」）を主繊維として抄造法により製造された不織布（坪量７２ｇ／ｍ^２）に含浸し、１４５℃で７分間乾燥して、樹脂量６５質量％のプリプレグを得た。
【００２９】
実施例１３
２，２’−ビス（４−シアネートフェニル）プロパンのオリゴマ（ロンザ製「ＰＲＩＭＡＳＥＴ　ＢＡ２３０Ｓ」）５００ｇとその重合触媒であるナフテン酸マンガン０．７ｇ、ｐ−ビニルフェノールとスチレンの共重合体の臭素化物１５ｇをメチルエチルケトン（ＭＥＫ）：トルエン＝４０：６０体積％の混合溶媒１３００ｍｌに溶解させて調製したワニスを、実施例１２と同様の不織布に含浸し、１４５℃で５分間乾燥して、樹脂量６８質量％のプリプレグを得た。
【００３０】
実施例１４〜２６（プリント基板用両面銅張り積層板の製造）
実施例１〜１３で作製した各プリプレグをそれぞれ８枚重ね、その表面に、１８μｍ厚の電解銅箔をそのマット面を内側にして重ね、２０５℃で９５分間、真空プレスで加熱加圧成形して両面銅張り積層板を作製した。
これらの各両面銅張り積層板から幅１．５ｍｍ、長さ７０ｍｍの棒状の試験片を切り出し、銅箔をエッチアウトした後、１，２，５，１０ＧＨｚでの誘電率と誘電正接を測定した。結果を表２に示す。なお、測定は、アジレント・テクノロジ社製ネットワークアナライザ８７２２ＥＳと各周波数対応の空洞共振器を用い、空洞共振器摂動法で実施した。
表２には、後述する比較例１〜３のにおけるプリプレグを用いて作製した両面銅張り積層板の誘電率と誘電正接についても示した。
【００３１】
【表２】

【００３２】
実施例２７〜３９（プリント基板の製造）
上記実施例１４〜２６の各両面銅張り積層板の表面銅箔に所定の配線パターンをエッチングにより形成し、その表面を酸系粗化液で粗面化して内層プリント基板とする。そして、各内層プリント基板の両面に、それぞれこれと同種のプリプレグを１枚ずつ重ね、さらに、１８μｍ厚の銅箔をそのマット面を内側にして重ね、２０５℃で９５分間、真空プレスで加熱加圧成形した。得られた積層板の所定の位置の表面銅箔にレーザ加工用の窓明けエッチング処理をし、内層プリント基板の配線パターンに達する孔（上径１５０μｍ，下径１００μｍ）をレーザ加工によりあけてから、所定位置にドリル加工（ドリル径０．３ｍｍ）により貫通穴加工をした。
レーザ加工穴内壁、ドリル加工穴内壁のデスミア処理後、パネルめっきをし、さらに所定の外層配線パターンを形成して、２．５４ｍｍピッチの１０００穴の連結めっきスルーホールと１．２７ｍｍピッチの１０００穴の連結表層ビア構造をもつ４層プリント基板を作製した。これら連結パターンは複数形成し、それぞれの間には逆電位が印加できるように配置した。
そして、表層にソルダーレジスト層を形成せずに、８５℃８５％の高温高湿環境下、１００Ｖ直流を印加して１０００時間行なった絶縁信頼性試験においても、−６５℃３０分／１２５℃３０分の熱衝撃試験１０００サイクルにおいても、すべての実施例で異常は認められず、絶縁抵抗値は最低でも８．３×１０^９Ω、接続抵抗値の変動も最大で４％であった。表３に、各プリプレグを使用した４層プリント基板作製時のプリプレグからの粉落ち、打痕の発生数を示す。また、同４層プリント基板を打抜き加工した端面の表面粗さ（非接触型表面粗さ計により測定）を示す。前記表面粗さは、測定した凹凸の最大高さと最大深さの和で表した。
【００３３】
比較例１
厚さ０．０６ｍｍのＢＴレジン系ガラス織布プリプレグ（三菱瓦斯化学製「ＧＨＰＬ８３０ＨＳ」）を使用するほかは、上記実施例と同様に４層プリント基板を作製した。上記と同様の絶縁信頼性試験において、絶縁抵抗値は３．６×１０^８Ωまで低下し、接続抵抗値の変動は１１％に達した。また、１層当り０．５８ヶ所の粉落ち、打痕が認められた。
【００３４】
比較例２
実施例１において、不織布をアラミド不織布（坪量７２ｇ／ｍ^２）に変えるほかは同様にしてプリプレグ（樹脂量５１重量％）を作製し、このプリプレグを用いて、上記実施例と同様に４層プリント基板を作製した。同様の絶縁信頼性試験では異常はなかったものの、１層当り０．４３ヶ所の粉落ち、打痕が認められた。
【００３５】
【表３】

【００３６】
吸湿耐熱性の確認
実施例１〜１３の各プリプレグ２枚を使用して、上記と同様にして、両面銅張り積層板を作製した。各両面銅張り積層板から５０ｍｍ角に切り出した試験片の銅箔を半分エッチアウトし、プレッシャクッカー処理を２時間行なった後、２８８℃の溶融半田に浮かべ、デラミ（表面フクレ）の発生時間を測定した。また、同時に銅箔を完全にエッチアウトした試験片で、上記プレッシャクッカー処理後の吸水率を測定した。結果を表４に示す。
【００３７】
比較例１のプリプレグを２枚使用して、上記と同様の試験片を作製し同様にデラミの発生時間を測定したところ、１８０秒であった。また、この時の吸水率は１．８％であった。
【００３８】
比較例２のプリプレグを２枚使用して、上記と同様の試験片を作製し同様にデラミの発生時間を測定したところ、１２０秒であった。また、この時の吸水率は１．９％であった。
【００３９】
比較例３
（ａ）多官能エポキシ樹脂（東都化成製「ＹＤＣＮ−７０４」）６７質量部、（ｂ）二官能エポキシ樹脂（ジャパンエポキシレジン製「Ｅｐ−８２８」）１３質量部、（ｃ）ビスフェノール類ノボラック樹脂（ジャパンエポキシレジン製「ＹＬＨ−１２９」）３０質量部、（ｄ）テトラブロモビスフェノールＡ３０質量部、硬化促進剤として２−エチル４−メチルイミダゾール０．２質量部を、メチルエチルケトン３０質量部に溶解してワニスを調製し、このワニスを、実施例１と同様の不織布に含浸し、１５０℃で７分乾燥して樹脂量７６質量％のプリプレグを得た。
このプリプレグを２枚使用して、上記と同様の試験片を作製し同様にデラミの発生時間を測定したところ、２０秒であった。また、この時の吸水率は１．５％であった。
【００４０】
【表４】

【００４１】
【発明の効果】
本発明によれば、低誘電率・低誘電正接で、各種加工性に優れ、吸水率の低い液晶ポリマ繊維を構成繊維として含む織布又は不織布と、その硬化物が低誘電率・低誘電正接であり、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物を含み、且つ、分子内に１個以上のイミド基を含有するイミド化合物を含まない熱硬化性樹脂組成物を組合せることにより、高周波帯域での誘電率、誘電正接が低く、加工性が良く、粉落ちしにくく、吸湿時の半田耐熱性に優れるプリント基板を提供することができる。このような基板を搭載した通信機器やコンピュータ類は、高周波領域での性能向上、信頼性向上、低コスト化の恩恵に与かる。
【００４２】
上記熱硬化性樹脂組成物が、さらに、低誘電率・低誘電正接で、可撓性、低吸水率の追加樹脂成分（ポリフェニレンエーテル、熱硬化性ポリフェニレンエーテル、ポリスチレン、ポリプロピレン、ポリエチレン、ジシクロペンタジエン樹脂、ジシクロペンタジエン構造をもつフェノール化合物、ジシクロペンタジエン構造をもつエポキシ樹脂、環化ポリブタジエン構造をもつフェノール樹脂、環化ポリブタジエン構造をもつエポキシ樹脂、ラダーシリコーン構造をもつオリゴマ、ラダーシリコーン構造をもつポリマ、シルセスキオキサン構造をもつオリゴマ、シルセスキオキサン構造をもつポリマから選ばれる）及び／又は低誘電率・低誘電正接化の障害とならない充填材（溶融シリカ、焼成シリカ、中空シリカ、ホウ酸マグネシウム、ケイ酸カルシウム、窒化ホウ素、アルミナから選ばれる）を含むことにより、上記効果は、一層顕著になる。
【００４３】
また、アラミド繊維を構成繊維として含む織布又は不織布と、分子内に１個以上のシアン酸エステル基を含有するシアネート化合物と臭素化フェノールを含み、且つ、分子内に１個以上のイミド基を含有するイミド化合物を含まない熱硬化性樹脂組成物を組合せることによっても、上記と同様の作用効果を奏することができる。加えて、難燃性の向上も可能である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a prepreg useful for a printed circuit board having a low dielectric constant and a low dielectric loss tangent in a high-frequency band and having excellent soldering heat resistance, a method for producing the prepreg, and a printed circuit board or a multilayer printed circuit board using the prepreg.
[0002]
[Prior art]
2. Description of the Related Art In recent years, communication devices and computers have been required to cope with higher operating environments, and substrate materials mounted thereon have been required to have lower dielectric constants and lower dielectric loss tangents. Conventionally, to meet such demands, thermoplastic resins such as Teflon (registered trademark) and polyphenylene ether have been frequently used. However, high cost, high temperature / high pressure molding process, poor dimensional stability, There were problems such as low strength and low adhesion to plating.
[0003]
Therefore, a material obtained by impregnating a glass woven fabric with a thermosetting resin represented by a BT resin (bismaleimide-triazine resin) containing a cyanate ester as a main component or a thermosetting polyphenylene ether has also been used heavily. However, for example, Patent Literature 1 and Patent Literature 2 have problems in brittleness during processing, low adhesion between resin and glass woven fabric, and heat resistance during moisture absorption. The brittleness during processing and the low adhesiveness with the glass woven fabric are problems when forming through holes by drilling. Cracks in the opening of the through-hole and peeling between the resin and the glass woven fabric on the inner wall of the through-hole lower the insulation reliability, and the roughness of the inner wall of the through-hole impairs the plated roundness and lowers the connection reliability. I was
[0004]
Also, in the manufacture of build-up substrates, the difficulty of processing glass woven fabric by laser results in leaving glass fibers protruding from the processing hole wall, making the via shape incorrect and the connection reliability between layers. Was impaired. Furthermore, the resin component and the glass component easily fall off from the prepreg (so-called “powder drop”), which cannot be removed on the surface of the copper foil during press molding, or form dents. Or cause malfunctions. On the other hand, as a material that does not use a glass woven fabric, a material in which an aramid fiber nonwoven fabric is impregnated with an epoxy resin (for example, Patent Document 3) has a low dielectric constant in that no glass is used, and has a low drilling / laser processing property. However, due to the hygroscopicity of the aramid fiber, the heat resistance to moisture absorption is rather lowered, and the dielectric loss tangent is also higher than that of a material using a glass woven fabric. In addition, there remains a problem of poor outer shape processing, and router processing must be performed to suppress fluffing of aramid fibers from the end face of the substrate.
[0005]
[Patent Document 1]
JP-A-2000-036666 (Claim 6)
[Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-261179 [Patent Document 3]
JP-A-2002-003626
[Problems to be solved by the invention]
The problem to be solved by the present invention, in view of the prior art as described above, is a print having a low dielectric constant in a high frequency band, a low dielectric loss tangent, good workability, less powder falling, and excellent solder heat resistance when absorbing moisture. It is to provide a useful prepreg for a substrate. Another object of the present invention is to provide a method for manufacturing the prepreg and a printed board or a multilayer printed board using the prepreg.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a first prepreg according to the present invention includes a cyanate compound containing one or more cyanate ester groups in a molecule, and contains one or more imide groups in a molecule. A thermosetting resin composition containing no imide compound is held by a woven or nonwoven fabric containing liquid crystal polymer fibers as constituent fibers. The printed circuit board according to the present invention includes an insulating layer formed by heating and pressing the prepreg layer. The concept of the printed circuit board includes not only a printed circuit board having printed wiring arranged on an outer layer of an insulating layer, but also a multilayer printed circuit board having printed wiring arranged on an inner layer via an insulating layer.
[0008]
The cyanate compound containing one or more cyanate ester groups in the molecule is trimerized by heating at a predetermined temperature to form and cure a triazine structure having a low dielectric constant and a low dielectric loss tangent. The liquid crystal polymer is not particularly limited, but is preferably a structure in which an aromatic diol and an aromatic dicarboxylic acid are polycondensed, and a polycondensation polymer of parahydroxybenzoic acid and 2-hydroxy-6-naphthoic acid is preferable. In particular, it shows a low dielectric constant and a low dielectric loss tangent in a high frequency band, is easy to perform various processes, can reduce powder falling, has a low water absorption, and has excellent solder heat resistance. A nonwoven fabric containing a liquid crystal polymer fiber as a constituent fiber may be made of a binder or pulp at the time of forming the nonwoven fabric.
[0009]
Although the object of the present invention can be achieved by a combination of the woven or nonwoven fabric and the thermosetting resin composition, the thermosetting resin composition further includes polyphenylene ether, thermosetting polyphenylene ether, polystyrene, Polypropylene, polyethylene, dicyclopentadiene resin, phenol compound with dicyclopentadiene structure, epoxy resin with dicyclopentadiene structure, phenol resin with cyclized polybutadiene structure, epoxy resin with cyclized polybutadiene structure, ladder silicone structure It is also preferable to include a component selected from an additional resin component group consisting of an oligomer, a polymer having a ladder silicone structure, an oligomer having a silsesquioxane structure, and a polymer having a silsesquioxane structure. By introducing such a structure having few polar groups and high flexibility, it is possible to further improve dielectric properties, workability, powder falling resistance, and solder heat resistance. The component selected from the additional resin component group is desirably blended in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of the cyanate compound having one or more cyanate ester groups in the molecule. The components selected from the additional resin component group may be one type or a combination of two or more types.
[0010]
The thermosetting resin composition preferably also contains a filler selected from the group consisting of fused silica, calcined silica, hollow silica, magnesium borate, calcium silicate, boron nitride, and alumina. By including the filler, workability, in particular, punchability and solder heat resistance can be improved. The filler selected from such a filler group is desirably blended in an amount of 5 to 1900 parts by mass with respect to 100 parts by mass of the cyanate compound having one or more cyanate ester groups in the molecule. The filler selected from the filler group may be one type or a combination of two or more types.
[0011]
The woven or non-woven fabric containing the liquid crystal polymer fiber as a constituent fiber can include at least one of an aromatic polyamide fiber and a glass fiber as another constituent fiber. By including an aromatic polyamide fiber, mechanical strength can be improved, and by including a glass fiber, cost can be reduced. In these cases, the amount of the liquid crystal polymer fibers in the total fibers constituting the woven or nonwoven fabric is preferably 25% by volume or more.
[0012]
The prepreg according to the present invention is prepared by dissolving the above thermosetting resin composition in a suitable organic solvent that is a good solvent so that the resin component is 40 to 60% by mass to prepare a varnish, and preparing a liquid crystal polymer fiber. It can be produced by impregnating the varnish into a woven or non-woven fabric contained as a constituent fiber, heating and drying at a temperature of 140 to 160 ° C. for 6 to 10 minutes to make the resin component B-stage.
[0013]
The second prepreg according to the present invention comprises a cyanate compound containing one or more cyanate ester groups in the molecule and a brominated phenol, and an imide compound containing one or more imide groups in the molecule. A thermosetting resin composition containing no aramid fibers is held by a woven or nonwoven fabric containing aramid fibers as constituent fibers. The printed board is provided with an insulating layer formed by heating and pressing the prepreg layer. The concept of the printed circuit board includes not only a printed circuit board having printed wiring arranged on an outer layer of an insulating layer, but also a multilayer printed circuit board having printed wiring arranged on an inner layer via an insulating layer.
[0014]
As a result, not only the inherent low dielectric constant, low dielectric loss tangent and flexibility of these compounds are taken into account, but also highly polar unreacted cyanic acid generated when the cyanate compound containing a cyanate ester group is cured. The ester group reacts with the phenolic hydroxyl group to prevent an increase in dielectric constant and dielectric loss tangent. In addition, flame retardancy can be improved.
[0015]
The brominated phenol is preferably at least one selected from brominated polyphenylene ethers having a hydroxyl group at one end of the main chain, brominated poly-p-vinylphenol, or a bromide of a copolymer of p-vinylphenol and styrene. One kind of resin.
Particularly preferred as the brominated phenol is a brominated polyphenylene ether having a hydroxyl group at one end of the main chain. It is desirable that the brominated polyphenylene ether is blended in an amount of 30 to 300 parts by mass with respect to 100 parts by mass of the cyanate compound having one or more cyanate ester groups in the molecule.
On the other hand, when a bromide of poly-p-vinylphenol or a bromide of a copolymer of p-vinylphenol and styrene is selected as the brominated phenol, these may have one or more cyanate ester groups in the molecule. The content is preferably 0.3 to 30 parts by mass with respect to 100 parts by mass of the cyanate compound contained.
[0016]
Also in the second prepreg, as in the first prepreg, it is desirable to mix a filler selected from the above-described filler group in the same amount as the above-described amount in the thermosetting resin composition.
[0017]
In the second prepreg, the woven or non-woven fabric containing aramid fiber as a constituent fiber may include, as another constituent fiber, at least one of a liquid crystal polymer fiber and a glass fiber. In these cases, the amount of aramid fibers in the total fibers constituting the woven or nonwoven fabric is preferably at least 25% by volume.
[0018]
The second prepreg is prepared by dissolving the thermosetting resin composition in a suitable organic solvent that is a good solvent so that the resin component is 20 to 80% by mass to prepare a varnish, and using aramid fibers as constituent fibers. The varnish can be produced by impregnating the varnish into a woven or nonwoven fabric containing the varnish, heating and drying at a temperature of 140 to 160 ° C. for 6 to 10 minutes, and B-stage the resin component.
[0019]
By doing as described above, it is possible to provide a prepreg useful for a printed circuit board which has a low dielectric constant and a low dielectric loss tangent in a high frequency band, has good workability, does not easily fall off powder, and has excellent solder heat resistance when absorbing moisture. .
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Example 1
1000 g of an oligomer (number average molecular weight 2500) of 2,2′-bis (4-cyanatophenyl) propane (“SKYLEX CA200” manufactured by Mitsubishi Gas Chemical), 0.6 g of cobalt naphthenate as a polymerization catalyst thereof, and 300 g of polyphenylene ether A varnish prepared by dissolving 150 g of hexabromocyclododecane as a flame retardant in 1000 ml of a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60% by volume was dried from a liquid crystal polymer fiber (Kuraray “Vectran”) by a dry method. The produced 70 μm-thick nonwoven fabric (Kuraray “Veculus”, basis weight 39.5 g / m ² ) was impregnated and dried at 145 ° C. for 7 minutes to obtain a prepreg having a resin amount of 70% by mass.
[0021]
Example 2
500 g of an oligomer (number average molecular weight 3000) of 2,2′-di (4-cyanatophenyl) hexafluoropropane (“AROCY F-10” manufactured by Asahi Chiba), 0.7 g of manganese naphthenate catalyst, and dicyclopentadiene structure 50 g of an alicyclic-modified phenol resin ("DPP-3H" manufactured by Nippon Petrochemical) and 150 g of a flame retardant tetrabromocyclooctane are dissolved in 1300 ml of a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60 vol% as a phenol compound having The varnish thus prepared was impregnated with a 50 μm-thick nonwoven fabric (Kuraray “Veculus”, basis weight 32.4 g / m ² ) manufactured from a liquid crystal polymer fiber (Kuraray “Vectran”) by a dry method, and 145. Drying at 5 ° C. for 5 minutes gave a prepreg having a resin amount of 68% by mass.
[0022]
Example 3
700 g of an alicyclic modified phenolic resin cyanate ("QUATREX7187" manufactured by Dow Chemical), 0.4 g of copper catalyst naphthenate, and an alicyclic modified phenolic resin ("PP-" manufactured by Nippon Petrochemical) as a phenol compound having a cyclized polybutadiene structure. 1000-180 "), prepared by dissolving 180 g of the flame retardant 1,2-dibromo-4- (1,2-dibromoethyl) cyclohexane 150 g in a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60% by volume in 1000 ml. The varnish thus obtained was impregnated into a nonwoven fabric produced by a wet method described below, and dried at 145 ° C. for 4 minutes to obtain a prepreg having a resin amount of 65% by mass.
Here, the nonwoven fabric is a mixture of 50% by volume of liquid crystal polymer fiber ("Vectran" manufactured by Kuraray) and 50% by volume of aromatic polyamide fiber ("Technola" manufactured by Teijin). % By mass is sprayed so as to contain 50% by mass and dried by heating to form a paper having a unit mass of 56 g / m ² , and is heated and compressed by passing between a pair of heat rolls having a linear pressure of 200 kg / cm and a temperature of 300 ° C. Was heat-sealed or deformed. The moving speed of the mixed nonwoven fabric passed between the hot rolls was set at 10 m / min.
[0023]
Example 4
800 g of an oligomer (number average molecular weight 2000) of 2,2′-bis (4-cyanatophenyl) propane (“AROCY B-10” manufactured by Asahi Ciba), 0.3 g of catalyst zinc octylate, dicyclopentadiene resin (Nippon Zeon) A varnish prepared by dissolving 230 g of "XEONEX480") and 150 g of a brominated flame retardant triphenylcyanurate in 1200 ml of a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60% by volume was used to prepare a liquid crystal polymer fiber (Kuraray "" Vectran ”), impregnated into a 70 μm-thick non-woven fabric (“ Veculus ”manufactured by Kuraray, basis weight 39.5 g / m ² ) manufactured by a dry method, dried at 145 ° C. for 7 minutes, and dried at 145 ° C. for 7 minutes. I got a prepreg.
[0024]
Example 5
800g of cyanated alicyclic modified phenolic resin ("QUATREX7187" manufactured by Dow Chemical), 0.4g of iron catalyst naphthenate, composite material with magnesium borate using polystyrene as matrix resin ("Teraave SM-6N" manufactured by Otsuka Chemical Co., Ltd.) A varnish prepared by dissolving 700 g of a flame retardant brominated triphenyl cyanurate in a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60% by volume in 1000 ml was impregnated into a nonwoven fabric prepared by the following wet method. A prepreg having a resin amount of 78% by mass was obtained by drying at 145 ° C. for 3 minutes, where the nonwoven fabric was prepared by mixing 30% by volume of liquid crystal polymer fiber (“VECTRAN” manufactured by Kuraray) and 70% by volume of glass fiber. Spray water-soluble epoxy resin as a resin binder to contain 8% by mass of solid content Heating papermaking those unit weight 28 g / m ² by dry, linear pressure 100 kg / cm, and heated compressed liquid crystal polymer fibers heat fusing to deform the by by passing between a pair of hot rolls temperature 300 ° C. The moving speed of the mixed nonwoven fabric passed between the hot rolls was set at 10 m / min.
[0025]
Example 6
800 g of an oligomer (number average molecular weight 2000) of 2,2′-bis (4-cyanatophenyl) propane (“AROCY B-10” manufactured by Asahi Chiba), 0.5 g of cobalt octylate catalyst, and a silsesquioxane structure 1- (4-vinylphenyl) -3,5,7,9,11,13,15-heptacyclopentylpentacyclo- [9.5.1.1.1.1] -octasiloxane (made by Aldrich) as an oligomer A varnish prepared by dissolving 50 g of brominated triphenyl cyanurate as a flame retardant in 100 ml of a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60% by volume was dried from a liquid crystal polymer fiber (Kuraray “Vectran”). by law impregnated into a nonwoven fabric having a thickness of 70μm manufactured (manufactured by Kuraray "Bekurusu", basis weight 39.5 g / ^{m 2),} 45 and dried for 7 minutes at ° C., to obtain a resin amount 63 mass% of the prepreg.
[0026]
Examples 7 to 11
A varnish was prepared by mixing the varnish of Example 1 with various fillers shown in Table 1 in the amounts shown in the table, and a prepreg was produced in the same manner as in Example 1 using this varnish.
[0027]
[Table 1]

[0028]
Example 12
1,000 g of an oligomer (number average molecular weight 3000) of 2,2′-bis (4-cyanoatephenyl) propane (“PRIMASET BADCy” manufactured by Lonza), 0.6 g of cobalt naphthenate, which is a polymerization catalyst thereof, and 2500 g of brominated polyphenylene ether are methyl ethyl ketone. (MEK): A varnish prepared by dissolving in a mixed solvent of toluene = 40: 60% by volume in 2000 ml, and a nonwoven fabric (basis weight 72 g / m2) manufactured by a papermaking method using aramid fiber ("Technola" manufactured by Teijin) as a main fiber. ² ) and dried at 145 ° C. for 7 minutes to obtain a prepreg having a resin amount of 65% by mass.
[0029]
Example 13
500 g of an oligomer of 2,2′-bis (4-cyanatephenyl) propane (“PRIMASET BA230S” manufactured by Lonza), 0.7 g of manganese naphthenate as a polymerization catalyst thereof, and a bromide of a copolymer of p-vinylphenol and styrene A varnish prepared by dissolving 15 g of a mixed solvent of methyl ethyl ketone (MEK): toluene = 40: 60% by volume in a volume of 1,300 ml was impregnated into the same nonwoven fabric as in Example 12, dried at 145 ° C. for 5 minutes, and dried. % By mass of the prepreg was obtained.
[0030]
Examples 14 to 26 (Production of double-sided copper-clad laminate for printed circuit board)
Eight pieces of each prepreg prepared in Examples 1 to 13 were stacked, and an electrolytic copper foil having a thickness of 18 μm was stacked on the surface of the prepreg with its mat side inward, and heated and pressed by a vacuum press at 205 ° C. for 95 minutes. To produce a double-sided copper-clad laminate.
A rod-shaped test piece having a width of 1.5 mm and a length of 70 mm was cut out from each of these double-sided copper-clad laminates, and after etching out the copper foil, the dielectric constant and the dielectric loss tangent at 1, 2, 5, 10 GHz were measured. . Table 2 shows the results. The measurement was performed by a cavity resonator perturbation method using a network analyzer 8722ES manufactured by Agilent Technologies and a cavity resonator corresponding to each frequency.
Table 2 also shows the dielectric constant and the dielectric loss tangent of the double-sided copper-clad laminate manufactured using the prepregs of Comparative Examples 1 to 3 described below.
[0031]
[Table 2]

[0032]
Examples 27 to 39 (manufacture of printed circuit board)
A predetermined wiring pattern is formed on the surface copper foil of each of the double-sided copper-clad laminates of Examples 14 to 26 by etching, and the surface is roughened with an acid-based roughening solution to obtain an inner-layer printed board. Then, a prepreg of the same type is laminated on both sides of each inner layer printed circuit board one by one, and a copper foil of 18 μm thickness is laminated with its mat side inside, and heated by a vacuum press at 205 ° C. for 95 minutes. It was pressed. The surface copper foil at a predetermined position of the obtained laminate is subjected to a laser processing window opening etching process, and holes (upper diameter 150 μm, lower diameter 100 μm) reaching the wiring pattern of the inner printed board are formed by laser processing. A through hole was drilled at a predetermined position by drilling (drill diameter: 0.3 mm).
After desmearing the inner wall of the laser drilled hole and the inner wall of the drilled hole, panel plating is performed, and a predetermined outer layer wiring pattern is formed. Then, a connection plated through hole of 1,000 holes of 2.54 mm pitch and a 1000 hole of 1.27 mm pitch are formed. A four-layer printed circuit board having the connected surface layer via structure was manufactured. A plurality of these connection patterns were formed and arranged so that a reverse potential could be applied between them.
Then, without forming a solder resist layer on the surface layer, even in an insulation reliability test performed under a high-temperature and high-humidity environment of 85 ° C. and 85% and 100 V DC applied for 1000 hours, −65 ° C. 30 minutes / 125 ° C. 30 No abnormalities were observed in all the examples in the thermal shock test for 1000 cycles per minute, the insulation resistance was at least 8.3 × 10 ⁹ Ω, and the variation in connection resistance was at most 4%. Table 3 shows the number of powder drops and dents generated from the prepreg when producing a four-layer printed circuit board using each prepreg. In addition, the surface roughness (measured by a non-contact type surface roughness meter) of an end face obtained by punching the same four-layer printed circuit board is shown. The surface roughness was represented by the sum of the maximum height and the maximum depth of the measured irregularities.
[0033]
Comparative Example 1
A four-layer printed circuit board was produced in the same manner as in the above example except that a BT resin-based glass woven prepreg (“GHPL830HS” manufactured by Mitsubishi Gas Chemical) having a thickness of 0.06 mm was used. In the same insulation reliability test as above, the insulation resistance value was reduced to 3.6 × 10 ⁸ Ω, and the variation of the connection resistance value reached 11%. In addition, powder dropping and dents were observed at 0.58 locations per layer.
[0034]
Comparative Example 2
A prepreg (resin amount: 51% by weight) was prepared in the same manner as in Example 1 except that the nonwoven fabric was changed to an aramid nonwoven fabric (basis weight: 72 g / m ² ). A printed circuit board was manufactured. Although there was no abnormality in the same insulation reliability test, powder dropping and dents were observed at 0.43 places per layer.
[0035]
[Table 3]

[0036]
Confirmation of Moisture Absorption Heat Resistance A double-sided copper-clad laminate was produced in the same manner as described above using two prepregs of Examples 1 to 13. The copper foil of a test piece cut into a square of 50 mm from each double-sided copper-clad laminate was half-etched out, subjected to a pressure cooker treatment for 2 hours, and then floated on a molten solder at 288 ° C. to determine the time required for delamination (surface blistering). It was measured. At the same time, the water absorption of the test piece from which the copper foil was completely etched out after the pressure cooker treatment was measured. Table 4 shows the results.
[0037]
Using two prepregs of Comparative Example 1, a test piece similar to the above was prepared, and the time for occurrence of delamination was measured in the same manner. At this time, the water absorption was 1.8%.
[0038]
A test piece similar to the above was prepared using two prepregs of Comparative Example 2, and the time required for delamination was measured in the same manner. The result was 120 seconds. The water absorption at this time was 1.9%.
[0039]
Comparative Example 3
(A) 67 parts by mass of a polyfunctional epoxy resin (“YDCN-704” manufactured by Toto Kasei), (b) 13 parts by mass of a bifunctional epoxy resin (“Ep-828” manufactured by Japan Epoxy Resin), (c) bisphenol novolak resin 30 parts by mass of "YLH-129" (manufactured by Japan Epoxy Resin), 30 parts by mass of (d) tetrabromobisphenol A, and 0.2 parts by mass of 2-ethyl-4-methylimidazole as a curing accelerator are dissolved in 30 parts by mass of methyl ethyl ketone. A varnish was prepared, and the varnish was impregnated into the same nonwoven fabric as in Example 1 and dried at 150 ° C. for 7 minutes to obtain a prepreg having a resin amount of 76% by mass.
Using two prepregs, a test piece similar to the above was prepared, and the time required for delamination was measured in the same manner. As a result, the time was 20 seconds. The water absorption at this time was 1.5%.
[0040]
[Table 4]

[0041]
【The invention's effect】
According to the present invention, a woven or non-woven fabric containing a liquid crystal polymer fiber having a low dielectric constant and a low dielectric loss tangent, excellent in various processability, and having a low water absorption as a constituent fiber, and a cured product thereof having a low dielectric constant and a low dielectric loss tangent And combining a thermosetting resin composition containing a cyanate compound containing one or more cyanate ester groups in the molecule and containing no imide compound containing one or more imide groups in the molecule. This can provide a printed circuit board having a low dielectric constant and a low dielectric loss tangent in a high-frequency band, good workability, hardly falling off powder, and excellent solder heat resistance when absorbing moisture. Communication devices and computers equipped with such a board benefit from improved performance in a high frequency range, improved reliability, and reduced cost.
[0042]
The thermosetting resin composition further comprises an additional resin component having low dielectric constant, low dielectric loss tangent, flexibility and low water absorption (polyphenylene ether, thermosetting polyphenylene ether, polystyrene, polypropylene, polyethylene, dicyclopentadiene). Resin, phenolic compound with dicyclopentadiene structure, epoxy resin with dicyclopentadiene structure, phenolic resin with cyclized polybutadiene structure, epoxy resin with cyclized polybutadiene structure, oligomer with ladder silicone structure, ladder silicone structure A polymer, an oligomer having a silsesquioxane structure, or a polymer having a silsesquioxane structure) and / or a filler (fused silica, calcined silica, hollow silica, Magnesium borate, silica Calcium, boron nitride, by including chosen) alumina, the effect becomes more remarkable.
[0043]
Also, a woven or non-woven fabric containing aramid fibers as constituent fibers, a cyanate compound containing one or more cyanate ester groups in the molecule and a brominated phenol, and one or more imide groups in the molecule. The same action and effect as described above can be obtained by combining a thermosetting resin composition containing no imide compound. In addition, flame retardancy can be improved.

Claims

A liquid crystal polymer fiber comprising a thermosetting resin composition containing a cyanate compound containing one or more cyanate ester groups in the molecule and containing no imide compound containing one or more imide groups in the molecule. A prepreg, wherein the prepreg is held by a woven or non-woven fabric contained as a constituent fiber.

The thermosetting resin composition further comprises polyphenylene ether, thermosetting polyphenylene ether, polystyrene, polypropylene, polyethylene, dicyclopentadiene resin, phenol compound having dicyclopentadiene structure, epoxy resin having dicyclopentadiene structure, cyclization Addition of phenolic resin with polybutadiene structure, epoxy resin with cyclized polybutadiene structure, oligomer with ladder silicone structure, polymer with ladder silicone structure, oligomer with silsesquioxane structure, and polymer with silsesquioxane structure The prepreg according to claim 1, further comprising a component selected from a resin component group.

3. The prepreg according to claim 2, wherein a component selected from the additional resin component group is contained in an amount of 5 to 40 parts by mass based on 100 parts by mass of the cyanate compound having one or more cyanate ester groups in the molecule.

The thermosetting resin composition further comprises a filler selected from a filler group consisting of fused silica, calcined silica, hollow silica, magnesium borate, calcium silicate, boron nitride, and alumina. The prepreg according to any one of 1 to 3, above.

5. The prepreg according to claim 4, wherein a filler selected from the filler group is contained in an amount of 5 to 1900 parts by mass with respect to 100 parts by mass of the cyanate compound having one or more cyanate ester groups in the molecule.

The prepreg according to any one of claims 1 to 5, wherein the woven or nonwoven fabric containing the liquid crystal polymer fiber as a constituent fiber further contains at least one of an aromatic polyamide fiber and a glass fiber as a constituent fiber.

The prepreg according to claim 6, wherein the amount of the liquid crystal polymer fibers in the total fibers constituting the woven or nonwoven fabric is 25% by volume or more.

A thermosetting resin composition containing a cyanate compound containing one or more cyanate ester groups in the molecule and containing no imide compound containing one or more imide groups in the molecule is dissolved in a solvent. A varnish containing a resin component of 40 to 60% by mass is prepared, the varnish is impregnated into a woven or nonwoven fabric containing liquid crystal polymer fibers as constituent fibers, and heated and dried at a temperature of 140 to 160 ° C. for 6 to 10 minutes. Wherein the resin component is B-staged.

A thermosetting resin composition containing a cyanate compound containing one or more cyanate ester groups in the molecule and a brominated phenol, and containing no imide compound containing one or more imide groups in the molecule, A prepreg characterized by being held on a woven or nonwoven fabric containing aramid fibers as constituent fibers.

The prepreg according to claim 9, wherein the brominated phenol is a brominated polyphenylene ether having a hydroxyl group at one end of a main chain.

The prepreg according to claim 10, wherein the brominated polyphenylene ether is contained in an amount of 30 to 300 parts by mass with respect to 100 parts by mass of the cyanate compound having one or more cyanate ester groups in the molecule.

The prepreg according to claim 9, wherein the brominated phenol is at least one resin selected from brominated poly-p-vinylphenol and bromide of a copolymer of p-vinylphenol and styrene.

100 mass% of a cyanate compound containing at least one cyanate ester group in a molecule of at least one resin selected from brominated poly-p-vinylphenol and bromide of a copolymer of p-vinylphenol and styrene. The prepreg according to claim 12, wherein the prepreg is contained in an amount of 0.3 to 30 parts by mass per part.

The thermosetting resin composition further comprises a filler selected from a filler group consisting of fused silica, calcined silica, hollow silica, magnesium borate, calcium silicate, boron nitride, and alumina. The prepreg according to any one of 9 to 13, wherein

15. The prepreg according to claim 14, wherein a filler selected from the filler group is contained in an amount of 5 to 1900 parts by mass with respect to 100 parts by mass of the cyanate compound containing one or more cyanate ester groups in the molecule.

The prepreg according to any one of claims 9 to 15, wherein the woven or non-woven fabric containing aramid fiber as a constituent fiber further contains at least one of a liquid crystal polymer fiber and a glass fiber as a constituent fiber.

The prepreg according to claim 16, wherein the amount of the aramid fiber in the total fiber constituting the woven or nonwoven fabric is 25% by volume or more.

A thermosetting resin composition containing a cyanate compound containing one or more cyanate ester groups in the molecule and a brominated phenol and containing no imide compound containing one or more imide groups in the molecule is used as a solvent. To prepare a varnish containing 20 to 80% by mass of a resin component, impregnated into a woven or nonwoven fabric containing aramid fibers as constituent fibers, and dried by heating at a temperature of 140 to 160 ° C. for 6 to 10 minutes. Wherein the resin component is B-staged.

A printed circuit board, comprising an insulating layer formed by heating and pressing the layer of the prepreg according to any one of claims 1 to 7, and 9 to 17.