JP4150178B2 - Resin composition, prepreg and printed wiring board using the same - Google Patents

Description

前記式（Ｉ）で示されるノボラック型シアネート樹脂のｎは、特に限定されないが、１〜１０が好ましく、特に１〜７が好ましい。これより少ないとノボラック型シアネート樹脂は結晶化しやすくなり、汎用溶媒に対する溶解性が比較的低下するため、取り扱いが困難となる場合がある。また、これより多いと架橋密度が高くなりすぎ、吸水性の低下や、硬化物が脆くなるなどの現象を生じる場合がある。
【０００９】
前記シアネート樹脂及び／またはそのプレポリマーの重量平均分子量は、特に限定されないが、重量平均分子量５００〜４５００が好ましく、特に６００〜３０００が好ましい。これより小さいとプリプレグを作製した場合にタック性が生じ、プリプレグ同士が接触したとき互いに付着したり、樹脂の転写が生じたりする場合がある。また、これより大きいと反応が速くなりすぎ、銅張り積層板とした場合に、成形不良を生じたり、層間ピール強度が低下したりする場合がある。
前記シアネート樹脂の含有量は、特に限定されないが、樹脂組成物全体の５〜６０重量％が好ましく、特に１０〜５０重量％が好ましい。シアネート樹脂及び／またはそのプレポリマーが前記下限値未満では、耐熱性や低熱膨張化する効果が低下する場合があり、前記上限値を超えると架橋密度が高くなり自由体積が増えるため耐湿性が低下する場合がある。
【００１０】
本発明の樹脂組成物には、フェノール樹脂を用いる。フェノール樹脂としては、ノボラック型フェノール樹脂、レゾール型フェノール樹脂、アリールアルキレン型フェノール樹脂等が挙げられる。これらの中でもアリールアルキレン型フェノール樹脂が好ましい。これにより、さらに耐熱性を向上させることができる。前記アリールアルキレン型フェノール樹脂としては、例えばキシリレン型フェノール樹脂、ビフェニルジメチレン型フェノール樹脂等が挙げられる。ビフェニルジメチレン型フェノール樹脂は、例えば式（ＩＩ）で示すことができる。
【化２】

前記式（ＩＩ）で示されるビフェニルジメチレン型フェノール樹脂のｎは、２〜８が好ましい。これより少ないと耐熱性が低下する場合がある。また、これより多いと他の樹脂との相溶性が低下し、作業性が悪くなる場合があるため好ましくない。前述のシアネート樹脂及び／またはそのプレポリマー（特にノボラック型シアネート樹脂）とアリールアルキレン型フェノール樹脂との組合せにより、架橋密度をコントロールし、金属と樹脂との密着性を向上することができる。
【００１１】
前記フェノール樹脂の含有量は、特に限定されないが、樹脂組成物全体の１〜５５重量％が好ましく、特に５〜４０重量％が好ましい。フェノール樹脂が前記下限値未満では耐熱性が低下する場合があり、前記上限値を超えると低熱膨張の特性が損なわれる場合がある。
前記フェノール樹脂の重量平均分子量は、特に限定されないが、重量平均分子量４００〜１８０００が好ましく、特に５００〜１５０００が好ましい。重量平均分子量が前記範囲より少ないとプリプレグにタック性が生じるなどの問題が起こる場合が有り、これより多いとプリプレグ作製時、基材への含浸性が低下し、均一な製品が得られないなどの問題が起こる場合がある。
【００１２】
本発明では、無機充填材を用いるものである。これにより、低熱膨張化、及び難燃性の向上が図られる。
また、前述したシアネート樹脂及び／またはそのプレポリマー（特にノボラック型シアネート樹脂）と無機充填材との組合せにより、弾性率を向上することができる。
前記無機充填材としては、例えばタルク、アルミナ、ガラス、シリカ、マイカ等を挙げることができる。これらの中でもシリカが好ましく、溶融シリカが低膨張性に優れる点で好ましい。その形状は破砕状、球状があるが、ガラス基材への含浸性を確保するために樹脂組成物の溶融粘度を下げるには球状シリカを使うなど、その目的にあわせた使用方法が採用される。
【００１３】
前記無機充填材の平均粒径は、特に限定されないが、０．０１〜５μｍが好ましく、特に０．２〜２μｍが好ましい。無機充填材の粒径が前記下限値より少ないとワニスの粘度が高くなるため、プリプレグ作製時の作業性に影響を与える場合がある。また、前記上限値より多いと、ワニス中で無機充填剤の沈降等の現象が起こるため望ましくない。
更に平均粒径５μｍ以下の球状溶融シリカが好ましく、特に平均粒径２μｍ以下の球状溶融シリカが好ましい。これにより、無機充填剤の充填性を向上させることができる。
前記無機充填材の含有量は、樹脂組成物全体の３０〜８０重量％が好ましく、特に４０〜７０重量％が好ましい。無機充填材が前記範囲内であると低熱膨張、低吸水とすることができる。
【００１４】
本発明の樹脂組成物では、特に限定されないが、樹脂成分として更にエポキシ樹脂を用いることが好ましい。これにより、シアネート樹脂及び／またはそのプレポリマーの反応性を向上させることが出来る。
エポキシ樹脂としては、例えばフェノールノボラック型エポキシ樹脂、ビスフェノール型エポキシ樹脂、ナフタレン型エポキシ樹脂、アリールアルキレン型エポキシ樹脂等が挙げられる。これらの中でもアリールアルキレン型エポキシ樹脂が好ましい。これにより、耐湿性を向上することができる。
前記アリールアルキレン型エポキシ樹脂とは、繰り返し単位中に一つ以上のアリールアルキレン基を有するエポキシ樹脂をいう。例えばキシリレン型エポキシ樹脂、ビフェニルジメチレン型エポキシ樹脂等が挙げられる。これらの中でもビフェニルジメチレン型エポキシ樹脂が好ましい。ビフェニルジメチレン型エポキシ樹脂は、例えば式（ＩＩＩ）で示すことができる。
【化３】

前記式（ＩＩＩ）で示されるビフェニルジメチレン型エポキシ樹脂のｎは、特に限定されないが、１〜１０が好ましく、特に２〜５が好ましい。これより少ないとビフェニルジメチレン型エポキシ樹脂は結晶化しやすくなり、汎用溶媒に対する溶解性が比較的低下するため、取り扱いが困難となる場合がある。また、これより多いと樹脂の流動性が低下し、成形不良等の原因となる場合がある。更に、前述のシアネート樹脂及び／またはそのプレポリマー（特にノボラック型シアネート樹脂）とアリールアルキレン型エポキシ樹脂（特にビフェニルジメチレン型エポキシ樹脂）との組合せを用いて銅張り積層板を作製した場合、優れた寸法安定性を得ることが出来る。
【００１５】
前記エポキシ樹脂の重量平均分子量は、特に限定されないが、重量平均分子量５００〜２００００が好ましく、特に８００〜１５０００が好ましい。重量平均分子量が前記範囲より少ないとプリプレグにタック性が生じるなどの問題が起こる場合が有り、これより多いとプリプレグ作製時、基材への含浸性が低下し、均一な製品が得られないなどの問題が起こる場合がある。
前記エポキシ樹脂の含有量は、特に限定されないが、樹脂組成物全体の１〜５５重量％が好ましく、特に２〜４０重量％が好ましい。樹脂が前記下限値未満では、シアネート樹脂の反応性が低下したり、得られる製品の耐湿性が低下したり場合があり、前記上限値を超えると耐熱性が低下する場合がある。
【００１６】
本発明の樹脂組成物では、上記シアネート樹脂及び／またはそのプレポリマー、フェノール樹脂及びエポキシ樹脂の一部をビニルエステル樹脂、メラミン樹脂等の他の熱硬化性樹脂、フェノキシ樹脂、ポリイミド樹脂、ポリアミドイミド樹脂、ポリフェニレンオキサイド樹脂、ポリエーテルスルホン樹脂等の熱可塑性樹脂と併用しても良い。
【００１７】
本発明の樹脂組成物では、特に限定されないが、カップリング剤を用いることが好ましい。カップリング剤は樹脂と無機充填剤の界面の濡れ性を向上させることにより、基材に対して樹脂および充填剤を均一に定着させ、耐熱性、特に吸湿後の半田耐熱性を改良するために配合する。カップリング剤としては通常用いられるものなら何でも使用できるが、これらの中でもエポキシシランカップリング剤、チタネート系カップリング剤、アミノシランカップリング剤及びシリコーンオイル型カップリング剤の中から選ばれる１種以上のカップリング剤を使用することが無機充填剤界面との濡れ性が高く、耐熱性向上の点で好ましい。本発明でカップリング剤は、無機充填剤に対して０．０５重量％以上、３重量％以下が望ましい。これより少ないと充填剤を十分に被覆できず十分な耐熱性が得られない場合があり、これより多いと反応に影響を与え、曲げ強度等が低下するようになるためこの範囲での使用が望ましい。
【００１８】
本発明の樹脂組成物では、必要に応じて硬化促進剤を用いてもよい。硬化促進剤としては公知の物を用いることが出来る。たとえば、ナフテン酸亜鉛、ナフテン酸コバルト、オクチル酸スズ、オクチル酸コバルト、ビスアセチルアセトナートコバルト（ＩＩ）、トリスアセチルアセトナートコバルト（ＩＩＩ）等の有機金属塩、トリエチルアミン、トリブチルアミン、ジアザビシクロ[２，２，２]オクタン等の３級アミン類、２−フェニル−４−メチルイミダゾール、２−エチル−４−エチルイミダゾール、２−フェニル−４−メチルイミダゾール、２−フェニル−４−メチル−５−ヒドロキシイミダゾール、２−フェニル−４，５−ジヒドロキシイミダゾール等のイミダゾール類、フェノール、ビスフェノールＡ、ノニルフェノー等のフェノール化合物、酢酸、安息香酸、サリチル酸、パラトルエンスルホン酸等の有機酸等、またはこの混合物が挙げられる。
【００１９】
本発明の樹脂組成物では、必要に応じて、上記成分以外の添加物を特性を損なわない範囲で添加することが出来る。
【００２０】
次に、本発明のプリプレグについて説明する。
本発明のプリプレグは上記樹脂組成物を基材に含浸してなるものである。これにより、耐熱性、低膨張性および難燃性に優れたプリプレグを得ることができる。
前記基材としては、例えばガラス織布、ガラス不繊布、ガラスペーパー等のガラス繊維基材、紙、アラミド、ポリエステル、芳香族ポリエステル、フッ素樹脂等の合成繊維等からなる織布や不織布、金属繊維、カーボン繊維、鉱物繊維等からなる織布、不織布、マット類等が挙げられる。これらの基材は単独又は混合して使用してもよい。これらの中でもガラス繊維基材が好ましい。これにより、プリプレグの剛性、寸法安定性を向上することができる。
【００２１】
前記樹脂組成物を前記基材に含浸させる方法は、例えば基材を樹脂ワニスに浸漬する方法、各種コーターによる塗布する方法、スプレーによる吹き付ける方法等が挙げられる。これらの中でも、基材を樹脂ワニスに浸漬する方法が好ましい。これにより、基材に対する樹脂組成物の含浸性を向上することができる。なお、基材を樹脂ワニスに浸漬する場合、通常の含浸塗布設備を使用することができる。
【００２２】
前記樹脂ワニスに用いられる溶媒は、前記樹脂組成物に対して良好な溶解性を示すことが望ましいが、悪影響を及ぼさない範囲で貧溶媒を使用しても構わない。良好な溶解性を示す溶媒としては、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、シクロペンタノン、シクロヘキサノン、ジメチルホルムアミド、ジメチルアセトアミド、N-メチルピロリドン等が挙げられる。
前記樹脂ワニスの固形分は、特に限定されないが、前記樹脂組成物の固形分３０〜８０重量％が好ましく、特に４０〜７０重量％が好ましい。これにより、樹脂ワニスの基材への含浸性を向上できる。
前記基材に前記樹脂組成物を含浸させ、所定温度、例えば９０〜１８０℃で乾燥させることによりプリプレグを得ることが出来る。
【００２３】
次に、プリント配線板について説明する。
本発明のプリント配線板は、上記のプリプレグに金属箔を積層して加熱加圧成形してなるものである。これにより、耐熱性、低膨張性および難燃性に優れたプリント配線板を得ることができる。
プリプレグ１枚のときは、その上下両面もしくは片面に金属箔を重ねる。また、プリプレグを２枚以上積層することもできる。プリプレグ２枚以上積層するときは、積層したプリプレグの最も外側の上下両面もしくは片面に金属箔あるいはフィルムを重ねる。
次に、プリプレグと金属箔とを重ねたものを加熱加圧成形することでプリント配線板を得ることができる。前記加熱する温度は、特に限定されないが、１２０〜２２０℃が好ましく、特に１５０〜２００℃が好ましい。前記加圧する圧力は、特に限定されないが、１．５〜５ＭＰａが好ましく、特に２〜４ＭＰａが好ましい。 また、必要に応じて高温漕等で１５０〜３００℃の温度で後硬化を行ってもかまわない。
【００２４】
【実施例】
実施例１
ノボラック型シアネート樹脂（ロンザジャパン株式会社製、プリマセット ＰＴ−６０）２０重量部（以下、部と略す）、ビフェニルジメチレン型エポキシ樹脂（日本化薬株式会社製、ＮＣ−３０００Ｐ）１１重量部、ビフェニルジメチレン型フェノール樹脂（明和化成株式会社製、ＭＥＨ−７８５１−Ｓ）９重量部、及びエポキシシラン型カップリング剤（日本ユニカー株式会社製、Ａ−１８７）０．３重量部をメチルエチルケトンに常温で溶解し、球状溶融シリカＳＦＰ−１０Ｘ （電気化学工業株式会社製）１０部及びＳＯ−３２Ｒ（株式会社アドマテックス社製）を添加し、高速攪拌機を用いて１０分攪拌した。調製したワニスをガラス織布（厚さ２００μｍ、日東紡績製、ＷＥＡ−７６２８）に含浸し、１２０℃の加熱炉で２分乾燥してワニス固形分（プリプレグ中に樹脂とシリカの占める成分）が約５０％のプリプレグを得た。このプリプレグを所定枚数重ね、両面に１８μｍの銅箔を重ねて、圧力４ＭＰａ、温度２００℃で２時間加熱加圧成形することによって両面銅張積層板を得た。
【００２５】
得られた両面銅張積層板の評価方法を▲１▼〜▲４▼に示す。
▲１▼ガラス転移温度
厚さ０．６ｍｍの両面銅張積層板を全面エッチングし、得られた積層板から１０ｍｍ×６０ｍｍのテストピースを切り出し、ＴＡインスツルメント社製動的粘弾性測定装置ＤＭＡ９８３を用いて３℃／分で昇温し、ｔａｎδのピーク位置をガラス転移温度とした。
【００２６】
▲２▼線膨張係数
厚さ１．２ｍｍの両面銅張積層板を全面エッチングし、得られた積層板から２ｍｍ×２ｍｍのテストピースを切り出し、ＴＭＡを用いて厚み方向（Ｚ方向）の線膨張係数を５℃／分で測定した。
【００２７】
▲３▼難燃性
ＵＬ−９４規格に従い、１ｍｍ厚のテストピースを垂直法により測定した。
【００２８】
▲４▼吸水率
厚さ０．６ｍｍの両面銅張り積層板を全面エッチングし、得られた積層板から５０ｍｍ×５０ｍｍのテストピースを切り出し、ＪＩＳ６４８１に従い測定した。
【００２９】
▲５▼吸湿はんだ耐熱性
厚さ０．６ｍｍの両面銅張積層板から５０ｍｍ×５０ｍｍに切り出し、ＪＩＳ６４８１に従い半面エッチングを行ってテストピースを作成した。１２５℃のプレッシャークッカーで処理した後、２６０℃のはんだ槽に銅箔面を下にして浮かべ、１８０秒後にフクレが発生する処理時間を計測した。
【００３０】
実施例２〜７及び比較例１〜４
表１に示す配合にて、実施例１と同様の方法で両面銅張積層板を得た。評価方法も前述の通りである。
【００３１】
これらの銅張積層板の評価結果を表１に示す。各実施例で得られた銅張積層板は、ハロゲン系難燃剤およびリン化合物を使用していないにもかかわらず優れた難燃性を有し、ガラス転移温度が高く、線膨張係数が小さく、吸湿はんだ耐熱性にも優れることがわかる。
【００３２】
【表１】

【００３３】
表の注
１）Ｐｒｉｍａｓｅｔ ＰＴ−３０（ノボラック型シアネート樹脂、重量平均分子量約７００）：ロンザジャパン株式会社製
２）Ｐｒｉｍａｓｅｔ ＰＴ−６０（ノボラック型シアネート樹脂、重量平均分子量約２６００）：ロンザジャパン株式会社製
３）ＡｒｏＣｙ Ｂ−３０（ビスフェノールＡ型シアネート樹脂）：旭化成エポキシ株式会社製
４）ＮＣ−３０００Ｐ（ビフェニルアルキレン型エポキシ樹脂、エポキシ当量２７５）：日本化薬株式会社製
５）エピクロン Ｎ−７７５（ノボラック型エポキシ樹脂、エポキシ当量１９０）：大日本インキ化学工業株式会社製
６）ＰＲ−５１７１４（ノボラック樹脂、水酸基当量１０３）：住友ベークライト株式会社製
７）ＭＥＨ−７８５１−Ｓ（ビフェニルアルキレン型ノボラック樹脂、水酸基当量２０３）：明和化成株式会社製
８）ＳＦＰ−１０Ｘ（球状溶融シリカ、平均粒径０．３μｍ）：電気化学工業株式会社製
９）ＳＯ−３２Ｒ（球状溶融シリカ、平均粒径１．５μｍ）：株式会社アドマテックス製
１０）ＦＢ−５ＳＤＸ（球状溶融シリカ、平均粒径４．４μｍ）：電気化学工業株式会社製
１１）ＡＯ−８０２（球状アルミナ、平均粒径０．７μｍ）：株式会社アドマテックス製
１２）Ａ−１８７（エポキシシラン型カップリング剤）：日本ユニカー株式会社製
１３）２ＭＺ（２−メチルイミダゾール）：四国化成工業株式会社製
【００３４】
【発明の効果】
本発明における第一の効果は、ハロゲン化合物およびリン化合物を使用せずに優れた難燃性を有し、かつ高耐熱、低熱膨張の特性を発現しうる樹脂組成物、プリプレグ、及び銅張積層板が得られることである。
また、本発明における第二の効果は、プリプレグ等の厚み方向の熱膨張係数を制御することができることであり、これによって層間の接続強度を向上し、高温多湿雰囲気中での機械的、電気的な接続信頼性を改善することができることである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin composition, a prepreg, and a printed wiring board using the same.
[0002]
[Prior art]
In the field of semiconductors, a trend of shifting from conventional surface mounting to area mounting is progressing due to progress in high-density mounting technology, and new packages such as BGA and CSP are appearing and increasing. For this reason, the rigid substrate for interposers has been attracting more attention than before, and the demand for a high heat resistance and low thermal expansion substrate has increased.
[0003]
Further, in recent years, along with demands for higher functionality of electronic devices, electronic components have been integrated with higher density and further mounted with higher density. For this reason, printed wiring boards and the like for high-density mounting used for these are becoming smaller and higher in density than ever before.
Many build-up multilayer wiring boards have been adopted as a countermeasure for increasing the density of such printed wiring boards.
However, the build-up multilayer wiring board has a problem in that it is difficult to maintain mechanical and electrical connection reliability in a high-temperature and high-humidity atmosphere because the connection strength is reduced because the interlayer connection is made by fine vias. there were.
[0004]
Moreover, the resin member used for these semiconductors is often required to have flame retardancy. Conventionally, in order to impart this flame retardancy, it has been common to use halogen-based flame retardants such as brominated epoxy in epoxy resins. However, since halogen-containing compounds may cause dioxins, the use of halogen-based flame retardants has been avoided along with the recent serious environmental problems. A flame retardant system is now required. Phosphorus flame retardants have been highlighted due to the demands of these times, and phosphoric acid esters and red phosphorus have been studied.However, these conventional phosphorus flame retardants are easily hydrolyzed and have poor reaction with resins, so There was a problem such as a decrease in solder heat resistance.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a resin composition, a prepreg and a printed wiring board which are excellent in heat resistance, low thermal expansion and flame retardancy.
[0006]
[Means for Solving the Problems]
Such an object is achieved by the present invention described in the following (1) to (8).
(1) A resin composition comprising a cyanate resin and / or a prepolymer thereof, a phenol resin and an inorganic filler as essential components.
(2) The resin composition according to (1), wherein the cyanate resin and / or prepolymer thereof is a novolac-type cyanate resin and / or prepolymer thereof.
(3) The said cyanate resin is a resin composition as described in said (1) or (2) which is 5 to 60 weight% of the whole resin composition.
(4) The resin composition according to any one of (1) to (3), wherein the phenol resin is an arylalkylene type phenol resin.
(5) The resin composition according to any one of (1) and (4), wherein the inorganic filler is spherical fused silica having an average particle size of 2 μm or less.
(6) The said inorganic filler is a resin composition in any one of said (1) thru | or (5) which is 30 to 80 weight% of the whole resin composition.
(7) A prepreg obtained by impregnating a base material with the resin composition according to any one of (1) to (6) above.
(8) A printed wiring board obtained by laminating a metal foil on the prepreg according to the above (7) and heating and pressing.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the resin composition, the prepreg of the present invention, and the printed wiring board using the same will be described in detail.
The resin composition of the present invention is a resin composition containing a cyanate resin and / or a prepolymer thereof, a phenol resin and an inorganic filler as essential components.
The prepreg of the present invention is obtained by impregnating a base material with the above resin composition.
Moreover, the printed wiring board of the present invention is obtained by laminating a metal foil on the prepreg and heating and pressing.
[0008]
Hereinafter, the resin composition will be described.
In the present invention, a cyanate resin and / or a prepolymer thereof is used. Thereby, when making the resin composition of this invention into a printed wiring board, it can be set as high heat resistance and low thermal expansion.
The cyanate resin and / or the prepolymer thereof can be obtained, for example, by reacting a cyanogen halide with a phenol and prepolymerizing it by a method such as heating if necessary. Specific examples include bisphenol type cyanate resins such as novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, and tetramethylbisphenol F type cyanate resin. Among these, novolac type cyanate resin is preferable. Thereby, the heat resistance improvement by a crosslinking density increase and flame retardance, such as a resin composition, can be improved. The novolak-type cyanate resin is considered to have a high proportion of benzene rings due to its structure and easily carbonize.
As the novolak type cyanate resin, for example, those represented by the formula (I) can be used.
[Chemical 1]

Although n of the novolak-type cyanate resin represented by the formula (I) is not particularly limited, 1 to 10 is preferable, and 1 to 7 is particularly preferable. If it is less than this, the novolac-type cyanate resin will be easily crystallized, and the solubility in general-purpose solvents will be relatively lowered, which may make handling difficult. On the other hand, if the amount is larger than this, the crosslink density becomes too high, which may cause a phenomenon such as a decrease in water absorption and a cured product becoming brittle.
[0009]
The weight average molecular weight of the cyanate resin and / or prepolymer thereof is not particularly limited, but a weight average molecular weight of 500 to 4500 is preferable, and 600 to 3000 is particularly preferable. If it is smaller than this, tackiness may occur when the prepreg is produced, and when the prepregs come into contact with each other, they may adhere to each other or transfer of the resin may occur. On the other hand, if it is larger than this, the reaction becomes too fast, and in the case of a copper-clad laminate, molding defects may occur or the interlayer peel strength may be reduced.
Although content of the said cyanate resin is not specifically limited, 5 to 60 weight% of the whole resin composition is preferable, and 10 to 50 weight% is especially preferable. If the cyanate resin and / or its prepolymer is less than the lower limit, the heat resistance and the effect of low thermal expansion may be reduced, and if the upper limit is exceeded, the crosslinking density increases and the free volume increases, resulting in reduced moisture resistance. There is a case.
[0010]
A phenol resin is used for the resin composition of the present invention. Examples of the phenol resin include novolac type phenol resins, resol type phenol resins, aryl alkylene type phenol resins and the like. Among these, arylalkylene type phenol resins are preferable. Thereby, heat resistance can be improved further. Examples of the aryl alkylene type phenol resin include a xylylene type phenol resin and a biphenyl dimethylene type phenol resin. The biphenyl dimethylene type phenol resin can be represented by, for example, the formula (II).
[Chemical 2]

As for n of the biphenyl dimethylene type | mold phenol resin shown by said Formula (II), 2-8 are preferable. If it is less than this, the heat resistance may decrease. Moreover, when more than this, since compatibility with other resin falls and workability | operativity may worsen, it is unpreferable. The combination of the aforementioned cyanate resin and / or prepolymer thereof (particularly a novolac type cyanate resin) and an arylalkylene type phenol resin can control the crosslink density and improve the adhesion between the metal and the resin.
[0011]
Although content of the said phenol resin is not specifically limited, 1 to 55 weight% of the whole resin composition is preferable, and 5 to 40 weight% is especially preferable. When the phenol resin is less than the lower limit value, the heat resistance may be lowered, and when the upper limit value is exceeded, the characteristics of low thermal expansion may be impaired.
Although the weight average molecular weight of the said phenol resin is not specifically limited, The weight average molecular weight 400-18000 is preferable and 500-15000 is especially preferable. If the weight average molecular weight is less than the above range, problems such as tackiness may occur in the prepreg, and if it is more than this range, the impregnation property to the base material is lowered during preparation of the prepreg, and a uniform product cannot be obtained. Problems may occur.
[0012]
In the present invention, an inorganic filler is used. Thereby, low thermal expansion and improvement in flame retardancy are achieved.
Further, the elastic modulus can be improved by a combination of the cyanate resin and / or its prepolymer (particularly a novolac-type cyanate resin) and an inorganic filler.
Examples of the inorganic filler include talc, alumina, glass, silica, mica and the like. Among these, silica is preferable, and fused silica is preferable in that it has excellent low expansibility. The shape is crushed and spherical, but in order to reduce the melt viscosity of the resin composition in order to ensure the impregnation property to the glass substrate, a usage method adapted to the purpose such as using spherical silica is adopted. .
[0013]
The average particle size of the inorganic filler is not particularly limited, but is preferably 0.01 to 5 μm, and particularly preferably 0.2 to 2 μm. If the particle size of the inorganic filler is less than the lower limit, the viscosity of the varnish becomes high, which may affect the workability during prepreg production. Moreover, when more than the said upper limit, since phenomena, such as sedimentation of an inorganic filler, occur in a varnish, it is not desirable.
Further, spherical fused silica having an average particle size of 5 μm or less is preferable, and spherical fused silica having an average particle size of 2 μm or less is particularly preferable. Thereby, the filling property of an inorganic filler can be improved.
The content of the inorganic filler is preferably 30 to 80% by weight, and particularly preferably 40 to 70% by weight, based on the entire resin composition. When the inorganic filler is within the above range, low thermal expansion and low water absorption can be achieved.
[0014]
Although it does not specifically limit in the resin composition of this invention, It is preferable to use an epoxy resin further as a resin component. Thereby, the reactivity of cyanate resin and / or its prepolymer can be improved.
Examples of the epoxy resin include phenol novolac type epoxy resin, bisphenol type epoxy resin, naphthalene type epoxy resin, arylalkylene type epoxy resin and the like. Among these, aryl alkylene type epoxy resins are preferable. Thereby, moisture resistance can be improved.
The arylalkylene-type epoxy resin refers to an epoxy resin having one or more arylalkylene groups in a repeating unit. For example, a xylylene type epoxy resin, a biphenyl dimethylene type epoxy resin, etc. are mentioned. Among these, a biphenyl dimethylene type epoxy resin is preferable. A biphenyl dimethylene type | mold epoxy resin can be shown, for example by Formula (III).
[Chemical 3]

Although n of the biphenyl dimethylene type | mold epoxy resin shown by the said Formula (III) is not specifically limited, 1-10 are preferable and 2-5 are especially preferable. If the amount is less than this, the biphenyldimethylene type epoxy resin is easily crystallized, and the solubility in a general-purpose solvent is relatively lowered, which may make handling difficult. Moreover, when more than this, the fluidity | liquidity of resin will fall and it may become a cause of a molding defect. Further, when a copper-clad laminate is produced using a combination of the above-described cyanate resin and / or its prepolymer (particularly novolac-type cyanate resin) and arylalkylene-type epoxy resin (particularly biphenyldimethylene-type epoxy resin), it is excellent. Dimensional stability can be obtained.
[0015]
Although the weight average molecular weight of the said epoxy resin is not specifically limited, The weight average molecular weight 500-20000 is preferable and 800-15000 are especially preferable. If the weight average molecular weight is less than the above range, problems such as tackiness may occur in the prepreg, and if it is more than this range, the impregnation property to the base material is lowered during preparation of the prepreg, and a uniform product cannot be obtained. Problems may occur.
Although content of the said epoxy resin is not specifically limited, 1 to 55 weight% of the whole resin composition is preferable, and 2 to 40 weight% is especially preferable. If the resin is less than the lower limit, the reactivity of the cyanate resin may be reduced, or the moisture resistance of the resulting product may be reduced. If the resin exceeds the upper limit, the heat resistance may be reduced.
[0016]
In the resin composition of the present invention, a part of the cyanate resin and / or its prepolymer, phenol resin and epoxy resin is replaced with other thermosetting resins such as vinyl ester resin and melamine resin, phenoxy resin, polyimide resin and polyamideimide. You may use together with thermoplastic resins, such as resin, polyphenylene oxide resin, and polyether sulfone resin.
[0017]
Although it does not specifically limit in the resin composition of this invention, It is preferable to use a coupling agent. The coupling agent improves the wettability of the interface between the resin and the inorganic filler, thereby uniformly fixing the resin and the filler to the base material, and improving the heat resistance, particularly the solder heat resistance after moisture absorption. Blend. Any coupling agent can be used as long as it is usually used. Among these, at least one selected from an epoxy silane coupling agent, a titanate coupling agent, an aminosilane coupling agent, and a silicone oil type coupling agent. Use of a coupling agent is preferable in terms of high wettability with the inorganic filler interface and improvement in heat resistance. In the present invention, the coupling agent is desirably 0.05% by weight or more and 3% by weight or less with respect to the inorganic filler. If the amount is less than this, the filler may not be sufficiently coated and sufficient heat resistance may not be obtained. If the amount is more than this, the reaction will be affected, and the bending strength will decrease. desirable.
[0018]
In the resin composition of the present invention, a curing accelerator may be used as necessary. A well-known thing can be used as a hardening accelerator. For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), trisacetylacetonate cobalt (III), triethylamine, tributylamine, diazabicyclo [2, Tertiary amines such as 2,2] octane, 2-phenyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxy Examples include imidazoles such as imidazole and 2-phenyl-4,5-dihydroxyimidazole, phenolic compounds such as phenol, bisphenol A, and nonylphenone, organic acids such as acetic acid, benzoic acid, salicylic acid, and paratoluenesulfonic acid, and mixtures thereof. It is done.
[0019]
In the resin composition of the present invention, additives other than the above components can be added as necessary within a range that does not impair the characteristics.
[0020]
Next, the prepreg of the present invention will be described.
The prepreg of the present invention is obtained by impregnating a base material with the above resin composition. Thereby, the prepreg excellent in heat resistance, low expansibility, and a flame retardance can be obtained.
Examples of the base material include glass fiber base materials such as glass woven fabric, glass non-woven fabric, and glass paper, woven fabric and non-woven fabric made of synthetic fibers such as paper, aramid, polyester, aromatic polyester, and fluororesin, and metal fibers. Woven fabrics, nonwoven fabrics, mats and the like made of carbon fibers, mineral fibers, and the like. These substrates may be used alone or in combination. Among these, a glass fiber base material is preferable. Thereby, the rigidity and dimensional stability of a prepreg can be improved.
[0021]
Examples of the method of impregnating the base material with the resin composition include a method of immersing the base material in a resin varnish, a method of applying with various coaters, and a method of spraying with a spray. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition with respect to a base material can be improved. In addition, when a base material is immersed in a resin varnish, a normal impregnation coating equipment can be used.
[0022]
The solvent used in the resin varnish desirably has good solubility in the resin composition, but a poor solvent may be used as long as it does not adversely affect the resin varnish. Examples of the solvent exhibiting good solubility include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.
The solid content of the resin varnish is not particularly limited, but the solid content of the resin composition is preferably 30 to 80% by weight, and particularly preferably 40 to 70% by weight. Thereby, the impregnation property to the base material of the resin varnish can be improved.
A prepreg can be obtained by impregnating the base material with the resin composition and drying at a predetermined temperature, for example, 90 to 180 ° C.
[0023]
Next, the printed wiring board will be described.
The printed wiring board of the present invention is formed by laminating a metal foil on the prepreg and heating and pressing. Thereby, the printed wiring board excellent in heat resistance, low expansibility, and a flame retardance can be obtained.
When one prepreg is used, the metal foil is overlapped on both the upper and lower surfaces or one surface. Two or more prepregs can be laminated. When two or more prepregs are laminated, a metal foil or film is laminated on the outermost upper and lower surfaces or one surface of the laminated prepreg.
Next, a printed wiring board can be obtained by heat-pressing a laminate of a prepreg and a metal foil. Although the temperature to heat is not specifically limited, 120-220 degreeC is preferable and especially 150-200 degreeC is preferable. Although the pressure to pressurize is not particularly limited, it is preferably 1.5 to 5 MPa, and particularly preferably 2 to 4 MPa. Moreover, you may perform post-curing at the temperature of 150-300 degreeC with a high-temperature soot as needed.
[0024]
【Example】
Example 1
20 parts by weight (hereinafter abbreviated as “parts”) of novolac-type cyanate resin (Lonza Japan Co., Ltd., Primaset PT-60), 11 parts by weight of biphenyldimethylene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000P), 9 parts by weight of biphenyl dimethylene type phenol resin (Maywa Kasei Co., Ltd., MEH-7851-S) and 0.3 part by weight of epoxy silane type coupling agent (Nihon Unicar Co., Ltd., A-187) are added to methyl ethyl ketone at room temperature. Then, 10 parts of spherical fused silica SFP-10X (manufactured by Denki Kagaku Kogyo Co., Ltd.) and SO-32R (manufactured by Admatechs Co., Ltd.) were added and stirred for 10 minutes using a high-speed stirrer. The prepared varnish is impregnated into a glass woven fabric (thickness 200 μm, manufactured by Nitto Boseki Co., Ltd., WEA-7628) and dried in a heating furnace at 120 ° C. for 2 minutes to obtain a varnish solid (a component of resin and silica in the prepreg). About 50% prepreg was obtained. A predetermined number of the prepregs were stacked, 18 μm copper foils were stacked on both sides, and heat-press molding was performed at a pressure of 4 MPa and a temperature of 200 ° C. for 2 hours to obtain a double-sided copper-clad laminate.
[0025]
Evaluation methods of the obtained double-sided copper-clad laminate are shown in (1) to (4).
(1) A double-sided copper-clad laminate having a glass transition temperature thickness of 0.6 mm was etched on the entire surface, and a 10 mm × 60 mm test piece was cut out from the obtained laminate, and a dynamic viscoelasticity measuring apparatus DMA983 manufactured by TA Instruments Co., Ltd. The temperature was increased at 3 ° C./min using tan δ and the peak position of tan δ was defined as the glass transition temperature.
[0026]
(2) Linear expansion coefficient A double-sided copper-clad laminate with a thickness of 1.2 mm is etched all over, a 2 mm x 2 mm test piece is cut out from the obtained laminate, and linear expansion in the thickness direction (Z direction) is performed using TMA. The coefficient was measured at 5 ° C./min.
[0027]
(3) Incombustibility In accordance with UL-94 standard, a 1 mm thick test piece was measured by the vertical method.
[0028]
(4) A double-sided copper-clad laminate having a water absorption of 0.6 mm was etched on the entire surface, and a 50 mm × 50 mm test piece was cut out from the obtained laminate and measured according to JIS 6481.
[0029]
{Circle around (5)} Hygroscopic solder heat resistance A test piece was prepared by cutting a double-sided copper-clad laminate having a thickness of 0.6 mm into 50 mm × 50 mm and performing half-side etching in accordance with JIS6481. After processing with a 125 ° C. pressure cooker, the copper foil surface was floated down in a 260 ° C. solder bath, and the processing time for blistering after 180 seconds was measured.
[0030]
Examples 2-7 and Comparative Examples 1-4
With the formulation shown in Table 1, a double-sided copper-clad laminate was obtained in the same manner as in Example 1. The evaluation method is also as described above.
[0031]
Table 1 shows the evaluation results of these copper-clad laminates. The copper-clad laminate obtained in each example has excellent flame retardancy despite not using a halogen-based flame retardant and a phosphorus compound, has a high glass transition temperature, and a low coefficient of linear expansion, It turns out that it is excellent also in moisture absorption solder heat resistance.
[0032]
[Table 1]

[0033]
Note 1) Primaset PT-30 (Novolac type cyanate resin, weight average molecular weight of about 700): Lonza Japan Co., Ltd. 2) Primaset PT-60 (Novolac type cyanate resin, weight average molecular weight of about 2600): Lonza Japan Co., Ltd. 3) AroCy B-30 (bisphenol A type cyanate resin): Asahi Kasei Epoxy Corporation 4) NC-3000P (biphenyl alkylene type epoxy resin, epoxy equivalent 275): Nippon Kayaku Co., Ltd. 5) Epicron N-775 ( Novolac type epoxy resin, epoxy equivalent 190): Dainippon Ink Chemical Co., Ltd. 6) PR-51714 (novolac resin, hydroxyl group equivalent 103): Sumitomo Bakelite Co., Ltd. 7) MEH-7851-S (biphenylalkylene type novolac resin) ,water Acid group equivalent 203): Meiwa Kasei Co., Ltd. 8) SFP-10X (spherical fused silica, average particle size 0.3 μm): Denki Kagaku Kogyo Co., Ltd. 9) SO-32R (spherical fused silica, average particle size 1. 5 μm): Admatechs Co., Ltd. 10) FB-5SDX (spherical fused silica, average particle size 4.4 μm): Denki Kagaku Kogyo Co., Ltd. 11) AO-802 (spherical alumina, average particle size 0.7 μm): Stock 12) A-187 (epoxysilane coupling agent) manufactured by Nihon Unicar Co., Ltd. 13) 2MZ (2-methylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.
【The invention's effect】
The first effect of the present invention is that a resin composition, a prepreg, and a copper-clad laminate that have excellent flame retardancy and can exhibit high heat resistance and low thermal expansion characteristics without using a halogen compound and a phosphorus compound A board is obtained.
The second effect of the present invention is that the coefficient of thermal expansion in the thickness direction of the prepreg and the like can be controlled, thereby improving the connection strength between the layers, and mechanical and electrical properties in a high-temperature and high-humidity atmosphere. Connection reliability can be improved.

Claims (7)

A resin composition comprising a cyanate resin and / or a prepolymer thereof, an epoxy resin, a phenol resin and an inorganic filler as essential components,
The phenol resin is an aryl alkylene type phenol resin represented by the following formula (II):

(Where n is 2-8).   The resin composition according to claim 1, wherein the cyanate resin and / or prepolymer thereof is a novolac-type cyanate resin and / or prepolymer thereof.   The resin composition according to claim 1 or 2, wherein the cyanate resin is 5 to 60% by weight of the entire resin composition.   The resin composition according to claim 1, wherein the inorganic filler is spherical fused silica having an average particle size of 2 μm or less.   The resin composition according to any one of claims 1 to 4, wherein the inorganic filler is 30 to 80% by weight of the entire resin composition.   A prepreg obtained by impregnating a base material with the resin composition according to any one of claims 1 to 5.   A printed wiring board obtained by laminating a metal foil on the prepreg according to claim 6 and then heat-pressing it.