JP3962901B2 - Epoxy resin composition for sealing - Google Patents

Description

（式(1)中、-(O-X-O)-は、構造式(2)で表され、R¹、R²、R³、R⁷、R⁸は、同一または異なってもよく、炭素数6以下のアルキル基を示す。R⁴、R⁵、R⁶は、同一または異なってもよく、水素原子または炭素数6以下のアルキル基を示す。-(Y-O)-は、構造式(3)で定義される1種類の構造、または構造式(3)で定義される2種類以上の構造がランダムに配列したものである。R⁹、R¹⁰は、同一または異なってもよく、炭素数6以下のアルキル基を示す。R¹¹、R¹²は、同一または異なってもよく、水素原子または炭素数6以下のアルキル基を示す。 a、bは、少なくともいずれか一方が0でない0〜20の整数を示す。c、dは、少なくともいずれか一方が0でない0〜20の整数を示す。 jは、0〜10の整数を示す。）
【００１０】
本発明の請求項2に係わる封止用エポキシ樹脂組成物は、請求項1記載の封止用エポキシ樹脂組成物において、構造式(1)で表される両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体の-(O-X-O)-で表される構造式(2)の少なくともR¹、R²、R³、R⁷、R⁸がメチル基であり、あるいは、さらにR⁴、R⁵、R⁶のうち1つ以上がメチル基であり、-(Y-O)-が構造式(5)、あるいは構造式(4)と構造式(5)がランダムに配列した構造を有することを特徴とする。
【化４】

【００１１】
本発明の請求項3に係わる封止用エポキシ樹脂組成物は、請求項1記載の封止用エポキシ樹脂組成物において、構造式(1)で表される両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体の含有量が、上記エポキシ樹脂、硬化剤、及び両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体の合計量に対し1〜60重量%の範囲であることを特徴とする。
【００１２】
本発明の請求項4に係わる封止用エポキシ樹脂組成物は、請求項1記載の封止用エポキシ樹脂組成物において、上記無機充填材の含有量が、上記エポキシ樹脂、硬化剤、無機充填材、及び両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体の合計量に対し15〜95重量%の範囲であることを特徴とする。
【００１３】
以下に、本発明を詳細に説明する。
本発明の封止用エポキシ樹脂組成物は、エポキシ樹脂、硬化剤、無機充填材、及び両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体を含有する。
【００１４】
上記エポキシ樹脂組成物は、両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体を含有することで、低誘電率で機械的強度に優れ、且つ樹脂組成物の溶融粘度を小さくすることができる。上記樹脂組成物の溶融粘度が小さいと、封止成形の際に樹脂の流動性がよく、ボイドの発生が無く成形性が良好となる。
【００１５】
上記エポキシ樹脂は、ビフェニル型エポキシ樹脂単独でも、クレゾールノボラック型エポキシ樹脂、ナフタレン骨格型エポキシ樹脂、ビスフェノールA型エポキシ樹脂、ビスフェノールF型エポキシ樹脂、あるいはこれらの臭素化された難燃性エポキシ樹脂との混合でもよい。
【００１６】
本発明に特徴的に用いられる両末端にエポキシ基を有するポリフェニレンエーテルオリゴマー体(以下、2官能OPE-2Epと記す)について説明する。
上述の2官能OPE-2Epは、2価のフェノールと1価のフェノールとを酸化共重合して得られる構造式(6)で表されるポリフェニレンエーテルオリゴマー体(以下、2官能OPEと記す)を、エピクロロヒドリン等のハロゲン化グリシジルと塩基の存在下で脱ハロゲン化水素反応させることにより得られる。
【００１７】
【化５】

【００１８】
構造式(6)で表される2官能OPEとは、-(O-X-O)-が構造式(2)で表され、-(Y-O)-が構造式(3)で定義される1種類の構造、または構造式(3)で定義される2種類以上の構造がランダムに配列したものである。式中、R¹、R²、R³、R⁷、R⁸、R⁹、R¹⁰は、同一または異なってもよく、炭素数6以下のアルキル基である。R⁴、R⁵、R⁶、R¹¹、R¹²は、同一または異なってもよく、水素原子または炭素数6以下のアルキル基である。a、bは少なくともいずれか一方が0でない、0〜20の整数を示す。好ましくは、-(O-X-O)-がR¹、R²、R³、R⁶、R⁷、R⁸がメチル基であり、更にR⁴、R⁵が水素原子であり、-(Y-O)-が構造式(5)、あるいは構造式(4)と構造式(5)がランダムに配列した構造を有することが望ましい。
【００１９】
上述の構造式(6)で表される2官能OPEは、構造式(7)で表される2価のフェノールと、構造式(8)で定義される1価のフェノールの単独または混合物を、トルエン−アルコールあるいはケトン溶媒中で酸化重合することで効率的に製造することができる。
【００２０】
【化６】

【００２１】
ここで、構造式(7)の2価のフェノールとは、R¹、R²、R³、R⁷、R⁸は同一または異なってもよく、炭素数6以下のアルキル基である。R⁴、R⁵、R⁶は、同一または異なってもよく、水素原子または炭素数6以下のアルキル基であり、R¹、R²、R³、R⁷、R⁸が水素原子でないことが必須の2価のフェノールであり、2,3,3’,5,5’-ペンタメチル-(1,1’-ビフェニル)-4,4’-ジオール、2,2’，3,3’，5,5’-ヘキサメチル-(1,1’-ビフェニル)-4,4’-ジオールなどが好ましい。
【００２２】
次に、構造式(8)の1価のフェノールとは、R⁹、R¹⁰は同一または異なってもよく、炭素数6以下のアルキル基である。R¹¹、R¹²は同一または異なってもよく、水素原子または炭素数6以下のアルキル基である。特に、2,6位に置換基を有するもの単独、またはこれと3位あるいは3,5位に置換基を有するものが併用されることが好ましい。さらに好ましくは、単独では2,6-ジメチルフェノールがよく、併用では2,6-ジメチルフェノールと2,3,6-トリメチルフェノールがよい。
【００２３】
酸化の方法については直接酸素ガス、あるいは空気を使用する方法がある。また、電極酸化の方法もある。いずれの方法でも良く、特に限定されない。安全性および設備投資が安価であることから空気酸化が好ましい。
【００２４】
酸素ガス、あるいは空気を用いて酸化重合をする場合の触媒としては、CuCl、CuBr、Cu₂SO₄、CuCl₂、CuBr₂、CuSO₄、CuI等の銅塩等の一種または二種以上が用いられ、上記触媒に加えて、モノ及びジメチルアミン、モノ及びジエチルアミン、モノ及びジプロピルアミン、モノ-及びジ-n-ブチルアミン、モノ-及びジ-sec-ジプロピルアミン、モノ及びジベンジルアミン、モノ及びジシクロヘキシルアミン、モノ及びジエタノールアミン、エチルメチルアミン、メチルプロピルアミン、ブチルジメチルアミン、アリルエチルアミン、メチルシクロヘキシルアミン、モルホリン、メチル-n-ブチルアミン、エチルイソプロピルアミン、ベンジルメチルアミン、オクチルベンジルアミン、オクチルクロロベンジルアミン、メチル（フェニルエチル）アミン、ベンジルエチルアミン、N-n-ブチルジメチルアミン、N,N’-ジ-tert-ブチルエチレンジアミン、ジ（クロロフェニルエチル）アミン、1-メチルアミノ-4-ペンテン、ピリジン、メチルピリジン、4-ジメチルアミノピリジン、ピペリジン等を一種または二種以上のアミンが併用される。銅塩及びアミンであれば、特にこれらに限定されるものではない。
【００２５】
反応溶媒としては、トルエン、ベンゼン、キシレン等の芳香族炭化水素系溶剤、メチレンクロライド、クロロホルム、四塩化炭素等のハロゲン化炭化水素系溶剤等に加えて、アルコール系溶剤あるいはケトン系溶剤などと併用することができる。アルコール系溶剤としては、メタノール、エタノール、ブタノール、プロパノール、メチルプロピレンジグリコール、ジエチレングリコールエチルエーテル、ブチルプロピレングリコール、プロピルプロピレングリコール等が挙げられ、ケトン系溶剤としては、アセトン、メチルエチルケトン、ジエチルケトン、メチルブチルケトン、メチルイソブチルケトン等が挙げられ、その他にはテトラヒドロフラン、ジオキサン等が挙げられるが、これらに限定されるものではない。
【００２６】
反応温度については、特には限定されないが、25〜50℃が好ましい。酸化重合が発熱反応のため、50℃以上では温度制御が困難で分子量制御が困難となる。25℃以下では反応速度が極端に遅くなるために、効率的な製造ができなくなる。
【００２７】
上述の2官能OPE-2Epは、構造式(1)で表される。すなわち、-(O-X-O)-は構造式(2)で表され、R¹、R²、R³、R⁷、R⁸は、同一または異なってもよく、炭素数6以下のアルキル基である。R⁴、R⁵、R⁶は、同一または異なってもよく、水素原子または炭素数6以下のアルキル基である。-(Y-O)-は構造式(3)で示され、R⁹、R¹⁰は、同一または異なってもよく、炭素数6以下のアルキル基である。R¹¹、R¹²は、同一または異なってもよく、水素原子または炭素数6以下のアルキル基である。-(Y-O)-は構造式(3)で定義される1種類の構造、または構造式(3)で定義される2種類以上の構造がランダムに配列したものである。 a,bは、少なくともいずれか一方が0でない、0〜20の整数を示す。c,dは、少なくともいずれか一方が0でない、0〜20の整数を示す。 jは、0から10の整数を示す。
【００２８】
以下に、便宜上、最も単純構造である構造式(6)で示される2官能OPEからの誘導体について説明する。2官能OPE-2Epを製造するには、上述の構造式(6)で表される2官能OPEを用いるが、反応液から分離した粉末または反応液に溶解した形のどちらでも用いることができる。
【００２９】
本発明の2官能OPE-2Epの製造方法について例示する。上述の構造式(6)で表される両末端にフェノール性水酸基を有する化合物をエピクロロヒドリン等のハロゲン化グリシジルと、塩基の存在下で、脱ハロゲン化水素反応させて合成することができる。
【００３０】
塩基としては、水酸化ナトリウム、水酸化カリウム、ナトリウムメトキシド、ナトリウムエトキシド、水酸化カルシウム、炭酸ナトリウム、炭酸カリウム、重炭酸ナトリウムなどが代表的なものであり、これらに限定されるものではない。
【００３１】
反応温度は、-10℃と110℃の間で行うことが好ましい。
【００３２】
上述の2官能OPE-2Epの数平均分子量は700〜3,000の範囲に制限される。上記数平均分子量が3,000を超えると樹脂組成物の溶融粘度が増大し、数平均分子量が700未満であると機械的強度や耐熱性が低下する。上記の2官能OPE-2Epは、溶融粘度が低く流動性が良好で、エポキシ樹脂との相溶性に優れ、また両末端にエポキシ基を有するため樹脂組成物の接着性が良好であり、かつ封止層の熱時強度がより優れる。その結果、半田等高温に曝された際に、クラックの発生を防ぐことができる。さらに、ポリフェニレンエーテル樹脂は低誘電特性を有する材料であるため、低誘電率の封止層を形成することができる。
【００３３】
本発明の封止用エポキシ樹脂組成物においては、上記2官能OPE-2Epの含有量が、上記エポキシ樹脂、2官能OPE-2Ep、及び硬化剤の合計量に対し1〜60重量%の範囲であることが望ましい。より好ましくは、5〜50重量%である。上記含有量が1重量%未満では封止層にクラックが発生し易く、含有量が60重量%を超えると封止成形の際に溶融粘度が高くなり、ボイドが生じ成形性が低下する。
【００３４】
本発明の封止用エポキシ樹脂組成物の構成材料である無機充填材は、例えば、シリカ、アルミナ等の無機粉末が挙げられる。上記無機充填材の好適な含有量は用途により異なる。
【００３５】
例えば、ポッティング成形の封止材の用途には、上記エポキシ樹脂、2官能OPE-2Ep、硬化剤、及び無機充填材の合計量に対して15〜60重量%の範囲が好ましく、より好ましくは20〜50重量%の範囲である。ポッティング成形の封止材の場合には、上記無機充填材の含有量が、15重量%未満では封止層の強度が低くなり、含有量が60重量%を超えると封止成形の際に成形性が低下する。
【００３６】
更には、インジェクション成形の封止材の用途には、上記エポキシ樹脂、2官能OPE-2Ep、硬化剤、及び無機充填材の合計量に対して60〜95重量%の範囲が好ましく、より好ましくは70〜90重量%の範囲である。インジェクション成形の封止材の場合には、上記無機充填材の含有量が、70重量%未満では封止層の吸湿率が増加しクラックが発生し易くなり、含有量が95重量%を超えると封止成形の際に溶融粘度が高くなり、ボイドが生じ成形性が低下する。
【００３７】
上記無機充填材は、エポキシ樹脂とのなじみを良くするために、カップリング剤で表面処理することが好ましい。上記カップリング剤としては、例えば、γ-グルシドキシプロピルトリメトキシシラン、γ-アミノプロピルトリエトキシシラン、N-フェニル-γ-アミノプロピルトリメトキシシラン等のシランカップリング剤が挙げられる。
【００３８】
上記封止用エポキシ樹脂組成物は、上述のエポキシ樹脂、2官能OPE-2Ep、硬化剤、及び無機充填材と共に、必要に応じて効果促進剤、離型剤、着色剤、難燃剤、低応力剤等を適宜含有したものでもよい。
【００３９】
上記効果促進剤としては、例えば、1,8-ジアザビシクロ(5,4,0)ウンデセン-7、トリエチレンジアミン、ベンジルジメチルアミン等の3級アミン類、2-メチルイミダゾール、2-エチル-4-メチルイミダゾール、2-フェニルイミダゾール、2-フェニル-4-メチルイミダゾール等のイミダゾール類、トリブチルフォスフィン、トリフェニルフォスフィン等の有機ホスフィン類等が挙げられる。なかでもトリフェニルフォスフィンは封止層の電気特性を良好とするので好ましい。
【００４０】
離型剤としては、例えば、カルナバワックス、ステアリン酸、モンタン酸、カルボキシル基含有ポリオレフィン等が挙げられる。着色剤としては、例えば、カーボンブラック等が挙げられ、上記難燃剤は、例えば、3酸化アンチモン等が挙げられ、低応力剤としては、例えば、シリコンゲル、シリコンゴム、シリコンオイル等が挙げられる。
【００４１】
【実施例】
次に、本発明を実施例に基づいて具体的に説明するが、本発明は以下の実施例により特に限定されるものではない。
[参考例1] 2官能OPE-2Epの製法(1)
【００４２】
(2官能OPEの製法)
撹拌装置、温度計、空気導入管、じゃま板のついた2Ｌの縦長反応器にCuCl 1.3g(0.013 mol)、ジ-n-ブチルアミン79.5g(0.62 mol)、メチルエチルケトン 600gを仕込み、反応温度40℃にて撹拌を行い、あらかじめ600gのメチルエチルケトンに溶解させた2,2’,3,3’,5,5’-ヘキサメチル-(1,1’-ビフェニル)-4,4’-ジオール41.8g(0.15mol)と2,6-ジメチルフェノール56.7g(0.46 mol)と2,3,6-トリメチルフェノール21.1g(0.16mol)の混合溶液(2価のフェノールと1価のフェノールのモル比率1:4)を2 L/minの空気のバブリングを行いながら120分かけて滴下し、さらに滴下終了後30分間、2 L/minの空気のバブリングを続けながら撹拌を行った。これにエチレンジアミン四酢酸二水素二ナトリウム水溶液を加え、反応を停止した。その後、1Nの塩酸水溶液で3回洗浄を行った後、イオン交換水で洗浄を行った。得られた溶液をエバポレイタ−で濃縮し、さらに減圧乾燥を行い、2官能OPE 111.9gを得た。得られた2官能OPEをゲル・パーミエーション・クロマトグラフィー(GPC)法で測定した結果、数平均分子量は1,000であった。また水酸基当量は520であった。
【００４３】
(2官能OPE-2Epの製法)
撹拌装置、温度計、滴下漏斗のついた反応器を100℃まで加熱し、上記で得られた2官能OPE 40.0g(水酸基：0.077mol)とエピクロロヒドリン213.5gを仕込んだ。その後、あらかじめエタノール22.0gにナトリウムエトキシド6.3g(0.092mol)を溶解した溶液を滴下漏斗から、60分かけて滴下し、さらに滴下終了後5時間の撹拌を行った。その後、0.1Nの塩酸水溶液で3回洗浄とイオン交換水での水洗、さらにはろ過を行い、生成塩と不純物を除去した。得られた溶液から過剰のエピクロロヒドリンを留去し、さらに減圧乾燥を行い、2官能OPE-2Ep 43.1gを得た(数平均分子量：1,150、以下この2官能OPE-2Epを[A]と記す)。得られた2官能OPE-2Ep [A]は、IRの分析によりフェノール性水酸基の吸収ピーク(3600cm-1)の消滅と、さらにNMRの分析によりグリシジルエーテル由来のピークの発現から、100%の官能基変換を確認した。
【００４４】
[参考例2] 2官能OPE-2Epの製法(2)
(2官能OPEの製法)
撹拌装置、温度計、空気導入管、じゃま板のついた2Ｌの縦長反応器にCuCl 1.1g(0.011mol)、ジ-n-ブチルアミン66.3g(0.51mol)、トルエン 500gを仕込み、反応温度40℃にて撹拌を行い、あらかじめ600gのメタノールに溶解させた2,2’,3,3’,5,5’-ヘキサメチル-(1,1’-ビフェニル)-4,4’-ジオール20.9g(0.077mol)と2,6-ジメチルフェノール75.6g(0.62mol)の混合溶液(2価のフェノールと1価のフェノールのモル比率1:8)を2 L/minの空気のバブリングを行いながら120分かけて滴下し、さらに滴下終了後30分間、2 L/minの空気のバブリングを続けながら撹拌を行った。これにエチレンジアミン四酢酸二水素二ナトリウム水溶液を加え、反応を停止した。その後、1Nの塩酸水溶液で3回洗浄を行った後、イオン交換水で洗浄を行った。得られた溶液をエバポレイタ−で濃縮し、2官能OPE の70%トルエン溶液とした。この一部をさらに濃縮および減圧乾燥を行い、粉末を得た。参考例1と同様にして測定したこのものの数平均分子量は1,620であった。また水酸基当量は810であった。
【００４５】
(2官能OPE-2Epの製法)
上記で得られた2官能OPEのトルエン溶液57.1g(水酸基：0.049mol)、エピクロロヒドリン228.5g、エタノール14.2g、及びナトリウムエトキシド4.0g(0.059mol)を使用する以外は、参考例1と同様な操作を行い、2官能OPE-2Ep 41.5gを得た(数平均分子量：1,780、以下この2官能OPE-2Epを[B]と記す)。また参考例1と同様にして、100%の官能基変換を確認した。
【００４６】
[参考例3] 2官能OPE-2Epの製法(3)
(2官能OPEの製法)
あらかじめ600gのメタノールに溶解させた2,2’,3,3’,5,5’-ヘキサメチル-(1,1’-ビフェニル)-4,4’-ジオール11.9g(0.044mol)と2,6-ジメチルフェノール79.9g(0.66mol)の混合溶液(2価のフェノールと1価のフェノールのモル比率1:15)を使用する以外は、参考例2と同様にして、2官能OPEの70%トルエン溶液を得た。この一部をさらに濃縮および減圧乾燥を行い、粉末を得た。参考例1と同様にして測定したこのものの数平均分子量は3,340であった。また水酸基当量は1,660であった。
【００４７】
(2官能OPE-2Epの製法)
上記で得られた2官能OPEのトルエン溶液71.4g(水酸基：0.024mol)、エピクロロヒドリン155.7g、エタノール6.9g、及びナトリウムエトキシド2.0g(0.029mol)を使用する以外は、参考例1と同様な操作を行い、2官能OPE-2Ep 49.8gを得た(数平均分子量：3,500、以下この2官能OPE-2Epを[C]と記す)。また参考例1と同様にして、100%の官能基変換を確認した。
【００４８】
[参考例4] エポキシ変性ポリフェニレンエーテル樹脂の製法
市販のポリフェニレンエーテル樹脂50g(三菱ガス化学株式会社製、数平均分子量：16,000、水酸基：0.003mol)、トルエン200g、エピクロロヒドリン2.9g、エタノール2.2g、及びナトリウムエトキシド0.6g(0.009mol)を使用する以外は、参考例1と同様な操作を行い、エポキシ変性ポリフェニレンエーテル樹脂(以下、エポキシ変性PPE樹脂と記す) 47.7gを得た(数平均分子量：16,000)。また参考例1と同様にして、95%の官能基変換を確認した。
【００４９】
(実施例1)
ビフェニル型エポキシ樹脂としてYX400H(油化シェル株式会社製、エポキシ当量195) 32.40部(7.02重量%)、クレゾールノボラック型エポキシ樹脂として195XL(住友化学株式会社製、エポキシ当量195) 10.80部(2.34重量%)、難燃性のビスフェノール型エポキシ樹脂としてEBS400T (住友化学株式会社製、エポキシ当量400) 3.78部(0.82重量%)、2官能OPE-2Ep [B]を11.50部(2.49重量%)、ナフタレン型フェノール樹脂組成物としてカヤハードNHN(日本化薬株式会社製、水酸基当量140) 15.93部(3.45重量%)、p-キシリレン・フェノール共重合体としてミレックス225-3L(三井化学株式会社製、水酸基当量173) 15.93部(3.45重量%)、溶融シリカ粉末360.50部(78.08重量%)をγ-グリシドキシプロピルトリメトキシシラン2.13部(0.46重量%)で処理したもの、トリフェニルフォスフィン0.95部(0.21重量%)、天然のカルナバを1.36部(0.30重量%)、カーボンブラックを0.99部(0.21重量%)、三酸化アンチモンを5.40部(1.17重量%)用いた。先ず、2官能OPE-2Ep [B]とエポキシ樹脂とをトルエンに溶解し、濃度30重量%の均一なトルエン溶液とした。このトルエン溶液からトルエンを除去し、エポキシ樹脂と2官能OPE-2Epの混合物を得た。この混合物に上述の材料を配合し、加熱ロールを使用して温度85℃で約5分間混練した。その後、直径5mm程度に粉砕し、封止用エポキシ樹脂組成物を得た。
【００５０】
(実施例2〜4及び比較例1〜3)
表1に示す配合割合で配合した以外は、実施例1と同様にして封止用エポキシ樹脂組成物を得た。得られた実施例1〜4、及び比較例1〜3の封止用エポキシ樹脂組成物を用い、半田耐熱試験、及び誘電率の評価を行った。また、樹脂組成物の溶融粘度、硬化物の曲げ強度、及び封止の際の成形性を測定した。
【００５１】
上記成形性及び半田耐熱試験は、以下の条件で行った。7.6mm*7.6mm*0.4mm(厚み)の半導体チップをダイパッド寸法8.2mm*8.2mmのアロイリードフレームに銀ペーストで実装し、外形寸法19mm*15mm*1.8mm(厚み)の60ピンフラットパッケージ成形金型を用いて成形し、試験片を作製した。得られた試験片の封止層中のボイドの有無を超音波探査装置で検査した。ボイドが無ければ成形性合格(○と表示)とし、ボイドが発生していれば成形性不合格(×と表示)とした。更に、上記試験片を各5個準備し、85℃、85%RHで72時間吸湿させた後、温度が260℃の半田に10秒間浸漬する操作を2回繰り返した。半田後、封止層のクラックの有無を超音波探査装置で観察し、クラックが発生しているものを不良と判定した。
上記誘電率は、JIS-K-6911の成形品の測定方法に基づいて測定した。
上記硬化物の曲げ強度は、封止用エポキシ樹脂組成物を硬化させ、10mm*4mm*100mmの試験片を作製し、この試験片を支点間距離64mm、クロスヘッドスピード2mm/minの条件で3点曲げ強度を常温と240℃で測定した。
上記樹脂組成物の溶融粘度は、高架式フローテスターを用い、175℃の溶融粘度を測定した。
【００５２】
以上の結果を表2に示した。数平均分子量700〜3,000の2官能OPE-2Epを用いた場合には、成形性が良好で、ボイドの発生が無く、低誘電率で、曲げ強度が高く、溶融粘度が低いことが確認できた。
【表１】

【表２】

【００５３】
【発明の効果】
本発明の2官能OPE-2Epを使用した封止用エポキシ樹脂組成物を用いた電子部品は、半田リフロー等の高温に曝された際に、クラックが発生することが無く、更に低誘電率の封止層が得られる。これにより信頼性が高く、さらにチップ回路の伝達速度が優れた半導体装置を提供できる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing epoxy resin composition for sealing electronic components such as semiconductors.
[0002]
[Prior art]
In semiconductor devices, epoxy resin compositions are widely used to seal electronic components such as semiconductors. The above epoxy resin composition is composed of various epoxy resins such as cresol novolac type epoxy resin, bisphenol A type epoxy resin, biphenyl type epoxy resin, its curing agent, inorganic filler, curing accelerator, coupling agent, mold release as required It is composed of an agent, a colorant and the like.
[0003]
With the recent demands for miniaturization and thinning, the above electronic components can be manufactured from the conventional pin insertion method (DIP: dual inline package, etc.) to the surface mounting method (SOP: small outline package, QFP: To quad flat packages). In the case of the surface mounting method, since the semiconductor device is processed at a high temperature (for example, 210 ° C. to 260 ° C.) such as solder reflow during mounting, high temperature heat is applied to the entire semiconductor device. In that case, the problem which a crack generate | occur | produces in the sealing layer sealed with the said epoxy resin composition, or moisture resistance falls significantly occurred easily.
[0004]
As measures against this, a semiconductor device before mounting is stored in a moisture-proof container for handling, or as an improvement of an epoxy resin composition for sealing, for example, a sealing material using a biphenyl type epoxy resin is disclosed in JP-A-1-108256 JP-A-64-24825 discloses a sealing material using an epoxy resin and a polyphenylene ether resin in combination.
[0005]
[Problems to be solved by the invention]
However, even with these sealing materials, for example, in the case of a thin sealing layer having a thickness of 2.0 mm or less, there is a problem that cracks are likely to occur during solder reflow, and further improvements in physical properties and signal transmission of chip circuits From the improvement of speed, it is required to seal with a sealing layer having a lower dielectric constant.
[0006]
The present invention has been made in view of the above-described facts, and the object of the present invention is to prevent cracks from being generated when exposed to high temperatures such as solder reflow, and further to a sealing layer having a low dielectric constant. Is to provide an epoxy resin composition for sealing.
[0007]
[Means for solving problems]
As a result of intensive investigations on an epoxy resin composition for sealing, the present inventors do not generate cracks when exposed to a high temperature such as solder reflow, and a sealing layer having a low dielectric constant can be obtained. The polyphenylene ether oligomer having an epoxy group at both ends represented by the structural formula (1) is used as a constituent material of the epoxy resin composition for sealing, and the present invention has been found. It came to be completed.
[0008]
That is, the epoxy resin composition for sealing according to claim 1 of the present invention has an epoxy resin as a constituent material, a curing agent, an inorganic filler, and a number average molecular weight represented by the structural formula (1) of 700 to 3,000. It contains a polyphenylene ether oligomer having an epoxy group at both ends.
[0009]
[Chemical 3]

(In the formula (1), - (OXO) - is represented by the structural formula ^{(2), R 1, R} 2, R 3, R 7, R 8 are the same or different, carbon number 6 or less of .R represents an alkyl group ^4, R ^5, R ⁶ are the same or different, hydrogen atoms frame other represents an alkyl group having 6 or less carbon atoms .- (YO) - is the structural formula (3 one of the structures defined by) or two or more kinds of structures defined by the formula (3) is obtained by a random arrangement .R ^9, R ¹⁰ are the same or different, carbon number 6 .R ^11, R ¹² having the following alkyl groups may be the same or different, hydrogen atoms coma others. a represents an alkyl group having 6 or less carbon atoms, b is not at least one is 0 .c represents an integer of 0 to 20, d is an integer from 0 to 20 at least one is not 0. j represents an integer of 0.)
[0010]
The epoxy resin composition for sealing according to claim 2 of the present invention is the epoxy resin composition for sealing according to claim 1, wherein the polyphenylene ether oligomer having an epoxy group at both ends represented by the structural formula (1) In the structural formula (2) represented by-(OXO)-in the body, at least R ¹ , R ² , R ³ , R ⁷ , R ⁸ are methyl groups, or R ⁴ , R ⁵ , R ⁶ including one or more is a methyl group, - (YO) - is structural formula (5) or formula (4) and the structural formula (5) is characterized by having a structure in which a random arrangement.
[Formula 4]

[0011]
An epoxy resin composition for sealing according to claim 3 of the present invention is a polyphenylene ether oligomer having epoxy groups at both ends represented by the structural formula (1) in the epoxy resin composition for sealing according to claim 1. The content of the body is in the range of 1 to 60% by weight with respect to the total amount of the epoxy resin, the curing agent, and the polyphenylene ether oligomer having an epoxy group at both ends.
[0012]
The epoxy resin composition for sealing according to claim 4 of the present invention is the epoxy resin composition for sealing according to claim 1, wherein the content of the inorganic filler is the epoxy resin, the curing agent, and the inorganic filler. And 15 to 95% by weight based on the total amount of the polyphenylene ether oligomer having an epoxy group at both ends.
[0013]
The present invention is described in detail below.
The epoxy resin composition for sealing of the present invention contains an epoxy resin, a curing agent, an inorganic filler, and a polyphenylene ether oligomer having an epoxy group at both ends.
[0014]
The above epoxy resin composition contains a polyphenylene ether oligomer having an epoxy group at both ends, so that it has a low dielectric constant and excellent mechanical strength, and can reduce the melt viscosity of the resin composition. When the melt viscosity of the resin composition is small, the resin has good fluidity during sealing molding, and voids are not generated and the moldability is good.
[0015]
The epoxy resin may be a biphenyl type epoxy resin alone, a cresol novolac type epoxy resin, a naphthalene skeleton type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a brominated flame retardant epoxy resin thereof. It may be mixed.
[0016]
A polyphenylene ether oligomer (hereinafter referred to as bifunctional OPE-2Ep) having an epoxy group at both ends, which is characteristically used in the present invention, will be described.
The above-mentioned bifunctional OPE-2Ep is a polyphenylene ether oligomer represented by the structural formula (6) obtained by oxidative copolymerization of divalent phenol and monovalent phenol (hereinafter referred to as bifunctional OPE). It can be obtained by dehydrohalogenation reaction in the presence of a glycidyl halide such as epichlorohydrin and a base.
[0017]
[Chemical formula 5]

[0018]
The bifunctional OPE represented by the structural formula (6) is a kind of one in which-( O- XO)-is represented by the structural formula (2) and-(YO)-is defined by the structural formula (3). A structure or two or more types of structures defined by the structural formula (3) are randomly arranged. ^{Wherein, R 1, R 2, R} 3, R 7, R 8, R 9, R 10 are the same or different, is a carbon number of 6 or less alkyl groups. ^{R 4, R 5, R 6} , R 11, R 12 are the same or different, hydrogen atoms frame other is an alkyl group having 6 or less carbon atoms. a and b each represents an integer of 0 to 20, wherein at least one of them is not 0. Preferably, - (OXO) - is ^{R 1, R 2, R 3} , R 6, R 7, R 8 is a methyl group, a further R ^4, R ⁵ is a hydrogen atom, - (YO) - is structure formula (5) or formula (4) and the structural formula (5) it is desirable to have a structure in which a random arrangement.
[0019]
The bifunctional OPE represented by the above structural formula (6) is a divalent phenol represented by the structural formula (7) and a monovalent phenol defined by the structural formula (8), alone or as a mixture, It can be efficiently produced by oxidative polymerization in a toluene-alcohol or ketone solvent.
[0020]
[Chemical 6]

[0021]
Here, the divalent phenol of formula ^{(7), R 1, R} 2, R 3, R 7, R 8 are the same or may be different from carbon number 6 an alkyl group. R ^4, R ^5, R ⁶ are the same or different, hydrogen atoms frame other is an alkyl group having 6 or less carbon ^{atoms, R 1, R 2, R} 3, R 7, R 8 is a hydrogen atom Is an essential divalent phenol, 2,3,3 ', 5,5'-pentamethyl- (1,1'-biphenyl) -4,4'-diol, 2,2', 3,3 ', 5,5'-Hexamethyl- (1,1'-biphenyl) -4,4'-diol is preferred.
[0022]
Next, a monovalent phenol of structure ^{(8), R 9, R} 10 may be the same or different, is a carbon number of 6 or less alkyl groups. R ^11, R ¹² may be the same or different, hydrogen atoms frame other is an alkyl group having 6 or less carbon atoms. In particular, it is preferable that those having a substituent at the 2,6 position alone or those having a substituent at the 3 position or the 3,5 position are used in combination. More preferably, alone 2,6-dimethyl phenol well, whereas in combination good 2,6-dimethylphenol and 2,3,6-trimethylphenol.
[0023]
As the oxidation method, there is a method of directly using oxygen gas or air. There is also an electrode oxidation method. Any method may be used and is not particularly limited. Air oxidation is preferred because safety and capital investment are inexpensive.
[0024]
As a catalyst for oxidative polymerization using oxygen gas or air, one or more of copper salts such as CuCl, CuBr, Cu ₂ SO ₄ , CuCl ₂ , CuBr ₂ , CuSO ₄ , CuI, etc. are used. In addition to the above catalysts, mono and dimethylamine, mono and diethylamine, mono and dipropylamine, mono- and di-n-butylamine, mono- and di-sec-dipropylamine, mono and dibenzylamine, mono And dicyclohexylamine, mono and diethanolamine, ethylmethylamine, methylpropylamine, butyldimethylamine, allylethylamine, methylcyclohexylamine, morpholine, methyl-n-butylamine, ethylisopropylamine, benzylmethylamine, octylbenzylamine, octylchlorobenzyl Amine, methyl (phenylethyl) amine, ben Dilethylamine, Nn-butyldimethylamine, N, N'-di-tert-butylethylenediamine, di (chlorophenylethyl) amine, 1-methylamino-4-pentene, pyridine, methylpyridine, 4-dimethylaminopyridine, piperidine, etc. One or two or more amines are used in combination. If it is a copper salt and an amine, it will not specifically limit to these.
[0025]
As a reaction solvent, in addition to aromatic hydrocarbon solvents such as toluene, benzene and xylene, halogenated hydrocarbon solvents such as methylene chloride, chloroform and carbon tetrachloride, etc., together with alcohol solvents or ketone solvents can do. Examples of alcohol solvents include methanol, ethanol, butanol, propanol, methyl propylene diglycol, diethylene glycol ethyl ether, butyl propylene glycol, and propyl propylene glycol. Ketone solvents include acetone, methyl ethyl ketone, diethyl ketone, and methyl butyl. Examples include ketones and methyl isobutyl ketone, and others include tetrahydrofuran and dioxane, but are not limited thereto.
[0026]
The reaction temperature is not particularly limited, but is preferably 25 to 50 ° C. Since oxidative polymerization is an exothermic reaction, it is difficult to control temperature and molecular weight at 50 ° C or higher. Below 25 ° C, the reaction rate becomes extremely slow, making it impossible to produce efficiently.
[0027]
The above-mentioned bifunctional OPE-2Ep is represented by the structural formula (1). That, - (OXO) - is represented by structural formula ^{(2), R 1, R} 2, R 3, R 7, R 8 are the same or different, is a carbon number of 6 or less alkyl groups. R ^4, R ^5, R ⁶ are the same or different, hydrogen atoms frame other is an alkyl group having 6 or less carbon atoms. - (YO) - is represented by the structural formula ^{(3), R 9, R} 10 are the same or different, is a carbon number of 6 or less alkyl groups. R ^11, R ¹² are the same or different, hydrogen atoms frame other is an alkyl group having 6 or less carbon atoms. -(YO)-is one type of structure defined by structural formula (3) or two or more types of structures defined by structural formula (3) randomly arranged . a and b each represent an integer of 0 to 20, at least one of which is not 0. c and d represent an integer of 0 to 20, at least one of which is not 0 . j represents an integer of 0 to 10.
[002 8 ]
Hereinafter, for the sake of convenience, a derivative from the bifunctional OPE represented by the structural formula (6), which is the simplest structure, will be described. In order to produce the bifunctional OPE-2Ep, the bifunctional OPE represented by the above structural formula (6) is used, but either a powder separated from the reaction solution or a form dissolved in the reaction solution can be used.
[002 9 ]
The production method of the bifunctional OPE-2Ep of the present invention is illustrated. It can be synthesized by dehydrohalogenating a compound having a phenolic hydroxyl group at both ends represented by the above structural formula (6) in the presence of a glycidyl halide such as epichlorohydrin and a base. .
[00 30 ]
Examples of the base include sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and the like, but are not limited thereto. .
[003 1 ]
The reaction temperature is preferably between -10 ° C and 110 ° C.
[003 2 ]
The number average molecular weight of the above-mentioned bifunctional OPE-2Ep is limited to a range of 700 to 3,000. When the number average molecular weight exceeds 3,000, the melt viscosity of the resin composition increases, and when the number average molecular weight is less than 700, mechanical strength and heat resistance decrease. The above-mentioned bifunctional OPE-2Ep has a low melt viscosity, good fluidity, excellent compatibility with an epoxy resin, and has an epoxy group at both ends, so that the adhesiveness of the resin composition is good, and sealing. The thermal strength of the stop layer is more excellent. As a result, generation of cracks can be prevented when exposed to high temperatures such as solder. Furthermore, since the polyphenylene ether resin is a material having low dielectric properties, a sealing layer having a low dielectric constant can be formed.
[003 3 ]
In the sealing epoxy resin composition of the present invention, the content of the bifunctional OPE-2Ep is in the range of 1 to 60% by weight with respect to the total amount of the epoxy resin, the bifunctional OPE-2Ep, and the curing agent. It is desirable to be. More preferably, it is 5 to 50% by weight. If the content is less than 1% by weight, cracks are likely to occur in the sealing layer, and if the content exceeds 60% by weight, the melt viscosity increases during sealing molding, voids occur, and the moldability decreases.
[003 4 ]
As for the inorganic filler which is a constituent material of the epoxy resin composition for sealing of this invention, inorganic powders, such as a silica and an alumina, are mentioned, for example. The suitable content of the inorganic filler varies depending on the application.
[003 5 ]
For example, for the potting molding sealing material, a range of 15 to 60% by weight is preferable with respect to the total amount of the epoxy resin, the bifunctional OPE-2Ep, the curing agent, and the inorganic filler, more preferably 20 It is in the range of ˜50% by weight. In the case of a potting molding sealing material, if the content of the inorganic filler is less than 15% by weight, the strength of the sealing layer is lowered, and if the content exceeds 60% by weight, molding is performed at the time of sealing molding. Sex is reduced.
[003 6 ]
Furthermore, for the use of a sealing material for injection molding, a range of 60 to 95% by weight with respect to the total amount of the epoxy resin, bifunctional OPE-2Ep, curing agent, and inorganic filler is preferable, and more preferably It is in the range of 70 to 90% by weight. In the case of a sealing material for injection molding, if the content of the inorganic filler is less than 70% by weight, the moisture absorption rate of the sealing layer increases and cracks are likely to occur, and if the content exceeds 95% by weight During sealing molding, the melt viscosity becomes high, voids are generated, and moldability is lowered.
[003 7 ]
The inorganic filler is preferably surface-treated with a coupling agent in order to improve compatibility with the epoxy resin. Examples of the coupling agent include silane coupling agents such as γ-glucidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.
[003 8 ]
The above-mentioned epoxy resin composition for sealing, together with the above-mentioned epoxy resin, bifunctional OPE-2Ep, curing agent, and inorganic filler, if necessary, effect promoter, mold release agent, colorant, flame retardant, low stress An agent or the like may be appropriately contained.
[00 39 ]
Examples of the effect promoter include tertiary amines such as 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, 2-methylimidazole, 2-ethyl-4-methyl Examples thereof include imidazoles such as imidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole, and organic phosphines such as tributylphosphine and triphenylphosphine. Of these, triphenylphosphine is preferable because it can improve the electrical properties of the sealing layer.
[004 0 ]
Examples of the mold release agent include carnauba wax, stearic acid, montanic acid, and carboxyl group-containing polyolefin. Examples of the colorant include carbon black and the like, examples of the flame retardant include antimony trioxide, and examples of the low stress agent include silicon gel, silicon rubber, and silicone oil.
004 1 ]
【Example】
EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not specifically limited by a following example.
[Reference Example 1] Production method of bifunctional OPE-2Ep (1)
[004 2 ]
(Production method of bifunctional OPE)
CuL 1.3 g (0.013 mol), di-n-butylamine 79.5 g (0.62 mol), and methyl ethyl ketone 600 g were charged into a 2 liter vertical reactor equipped with a stirrer, thermometer, air inlet tube and baffle, and the reaction temperature was 40 ° C. And 21.8 '(2,5'- 3,3', 5,5'-hexamethyl- (1,1'-biphenyl) -4,4'-diol dissolved in 600 g of methyl ethyl ketone in advance (0.15 mol), 2,6-dimethylphenol 56.7g (0.46 mol) and 2,3,6-trimethylphenol 21.1g (0.16mol) (molar ratio of divalent phenol to monovalent phenol 1: 4) Was added dropwise over 120 minutes while bubbling 2 L / min of air, and further stirred for 30 minutes after bubbling of 2 L / min of air after completion of dropping. Ethylenediaminetetraacetic acid dihydrogen disodium aqueous solution was added thereto to stop the reaction. Thereafter, washing was performed 3 times with a 1N aqueous hydrochloric acid solution, followed by washing with ion-exchanged water. The resulting solution was concentrated with an evaporator and further dried under reduced pressure to obtain 111.9 g of bifunctional OPE. As a result of measuring the obtained bifunctional OPE by gel permeation chromatography (GPC) method, the number average molecular weight was 1,000. The hydroxyl equivalent was 520.
[004 3 ]
(Production method of bifunctional OPE-2Ep)
A reactor equipped with a stirrer, a thermometer and a dropping funnel was heated to 100 ° C., and 40.0 g (hydroxyl group: 0.077 mol) of the bifunctional OPE obtained above and 213.5 g of epichlorohydrin were charged. Thereafter, a solution prepared by dissolving 6.3 g (0.092 mol) of sodium ethoxide in 22.0 g of ethanol in advance was added dropwise from the dropping funnel over 60 minutes, and further stirred for 5 hours after the completion of the addition. Thereafter, the resulting salt and impurities were removed by washing with 0.1N hydrochloric acid aqueous solution three times, with ion-exchanged water and further with filtration. Excess epichlorohydrin was distilled off from the resulting solution and further dried under reduced pressure to obtain 43.1 g of a bifunctional OPE-2Ep (number average molecular weight: 1,150, hereinafter referred to as [A] ). The resulting bifunctional OPE-2Ep [A] is 100% functional from the disappearance of the absorption peak (3600 cm-1) of the phenolic hydroxyl group by IR analysis and the appearance of a peak derived from glycidyl ether by NMR analysis. Group conversion was confirmed.
[004 4 ]
[Reference Example 2] Production method of bifunctional OPE-2Ep (2)
(Production method of bifunctional OPE)
CuL 1.1g (0.011mol), di-n-butylamine 66.3g (0.51mol), and toluene 500g were charged in a 2L vertical reactor equipped with a stirrer, thermometer, air inlet tube and baffle, reaction temperature 40 ℃ And 20.9 g of 2,2 ′, 3,3 ′, 5,5′-hexamethyl- (1,1′-biphenyl) -4,4′-diol dissolved in 600 g of methanol in advance (0.077 mol) and 2,6-dimethylphenol 75.6g (0.62mol) (molar ratio of divalent phenol to monovalent phenol 1: 8) over 120 minutes while bubbling 2 L / min of air. Then, the mixture was further stirred for 30 minutes after the completion of the dropwise addition while bubbling air at 2 L / min. Ethylenediaminetetraacetic acid dihydrogen disodium aqueous solution was added thereto to stop the reaction. Thereafter, washing was performed 3 times with a 1N aqueous hydrochloric acid solution, followed by washing with ion-exchanged water. The resulting solution was concentrated with an evaporator to obtain a 70% toluene solution of bifunctional OPE. A part of this was further concentrated and dried under reduced pressure to obtain a powder. The number average molecular weight of this product as measured in the same manner as in Reference Example 1 was 1,620. The hydroxyl equivalent was 810.
[004 5 ]
(Production method of bifunctional OPE-2Ep)
Reference Example 1 except that 57.1 g (hydroxyl group: 0.049 mol) of toluene solution of the bifunctional OPE obtained above, 228.5 g of epichlorohydrin, 14.2 g of ethanol, and 4.0 g (0.059 mol) of sodium ethoxide were used. In the same manner as above, 41.5 g of bifunctional OPE-2Ep was obtained (number average molecular weight: 1,780, hereinafter, this bifunctional OPE-2Ep is referred to as [B]). Further, in the same manner as in Reference Example 1, 100% functional group conversion was confirmed.
[004 6 ]
[Reference Example 3] Method for producing bifunctional OPE-2Ep (3)
(Production method of bifunctional OPE)
11.9 g (0.044 mol) of 2,2 ′, 3,3 ′, 5,5′-hexamethyl- (1,1′-biphenyl) -4,4′-diol dissolved in 600 g of methanol and 2,6 -Bifunctional OPE 70% toluene in the same manner as in Reference Example 2, except that a mixed solution of 79.9 g (0.66 mol) of dimethylphenol (molar ratio of divalent phenol to monovalent phenol 1:15) was used. A solution was obtained. A part of this was further concentrated and dried under reduced pressure to obtain a powder. The number average molecular weight of this product as measured in the same manner as in Reference Example 1 was 3,340. The hydroxyl equivalent was 1,660.
[004 7 ]
(Production method of bifunctional OPE-2Ep)
Reference Example 1 except that 71.4 g (hydroxyl group: 0.024 mol) of the bifunctional OPE obtained above, 155.7 g of epichlorohydrin, 6.9 g of ethanol, and 2.0 g (0.029 mol) of sodium ethoxide were used. The same operation was performed to obtain 49.8 g of bifunctional OPE-2Ep (number average molecular weight: 3,500, hereinafter, this bifunctional OPE-2Ep is referred to as [C]). Further, in the same manner as in Reference Example 1, 100% functional group conversion was confirmed.
[004 8 ]
[Reference Example 4] Preparation of epoxy-modified polyphenylene ether resin 50 g of commercially available polyphenylene ether resin (Mitsubishi Gas Chemical Co., Ltd., number average molecular weight: 16,000, hydroxyl group: 0.003 mol), toluene 200 g, epichlorohydrin 2.9 g, ethanol 2.2 g, and sodium ethoxide 0.6 g (0.009 mol) was used in the same manner as in Reference Example 1 to obtain 47.7 g of an epoxy-modified polyphenylene ether resin (hereinafter referred to as epoxy-modified PPE resin). Average molecular weight: 16,000). In the same manner as in Reference Example 1, 95% functional group conversion was confirmed.
[00 49 ]
(Example 1)
YX400H as biphenyl type epoxy resin (manufactured by Yuka Shell Co., Ltd., epoxy equivalent 195) 32.40 parts (7.02% by weight), 195XL as cresol novolac type epoxy resin (epoxy equivalents 195) 10.80 parts (2.34% by weight) ), EBS400T (epoxy equivalent 400, manufactured by Sumitomo Chemical Co., Ltd.) as a flame-retardant bisphenol type epoxy resin, 11.50 parts (2.49% by weight) of bifunctional OPE-2Ep [B], naphthalene type Kayahard NHN (manufactured by Nippon Kayaku Co., Ltd., hydroxyl equivalent 140) as a phenolic resin composition 15.93 parts (3.45% by weight), Milex 225-2L (manufactured by Mitsui Chemicals, hydroxyl equivalent 173 as a p-xylylene / phenol copolymer) ) 15.93 parts (3.45 wt%), 360.50 parts (78.08 wt%) fused silica powder treated with 2.13 parts (0.46 wt%) γ-glycidoxypropyltrimethoxysilane, 0.95 parts (0.21 wt%) triphenylphosphine %), Natural carna 1.36 parts (0.30 wt%), 0.99 parts of carbon black (0.21 wt%), 5.40 parts of antimony trioxide (1.17 wt%) was used. First, bifunctional OPE-2Ep [B] and an epoxy resin were dissolved in toluene to obtain a uniform toluene solution having a concentration of 30% by weight. Toluene was removed from this toluene solution to obtain a mixture of epoxy resin and bifunctional OPE-2Ep. The above materials were blended into this mixture and kneaded at a temperature of 85 ° C. for about 5 minutes using a heated roll. Thereafter, it was pulverized to a diameter of about 5 mm to obtain an epoxy resin composition for sealing.
[005 0 ]
(Examples 2 to 4 and Comparative Examples 1 to 3)
A sealing epoxy resin composition was obtained in the same manner as in Example 1, except that the blending ratios shown in Table 1 were blended. Using the obtained epoxy resin compositions for sealing of Examples 1 to 4 and Comparative Examples 1 to 3, solder heat resistance tests and dielectric constant evaluations were performed. Further, the melt viscosity of the resin composition, the bending strength of the cured product, and the moldability during sealing were measured.
005 1 ]
The moldability and solder heat resistance test were performed under the following conditions. A 7.6mm * 7.6mm * 0.4mm (thickness) semiconductor chip is mounted on an alloy lead frame with a die pad size of 8.2mm * 8.2mm with silver paste, forming a 60-pin flat package with an outer dimension of 19mm * 15mm * 1.8mm (thickness) Molding was performed using a mold to prepare a test piece. The presence or absence of voids in the sealing layer of the obtained test piece was inspected with an ultrasonic probe. If there was no void, the moldability was accepted (indicated by ◯), and if void was generated, the moldability was rejected (indicated by x). Further, five test pieces were prepared for each sample, and moisture absorption was performed at 85 ° C. and 85% RH for 72 hours, and then the operation of immersing in a solder having a temperature of 260 ° C. for 10 seconds was repeated twice. After soldering, the presence or absence of cracks in the sealing layer was observed with an ultrasonic exploration device, and those having cracks were determined to be defective.
The dielectric constant was measured based on a method for measuring a molded product of JIS-K-6911.
The bending strength of the cured product is 3 under the conditions that the epoxy resin composition for sealing is cured and a test piece of 10 mm * 4 mm * 100 mm is produced, and the distance between fulcrums is 64 mm and the crosshead speed is 2 mm / min. The point bending strength was measured at normal temperature and 240 ° C.
The melt viscosity of the resin composition was measured at 175 ° C. using an elevated flow tester.
005 2 ]
The results are shown in Table 2. When bifunctional OPE-2Ep having a number average molecular weight of 700 to 3,000 was used, it was confirmed that the moldability was good, no void was generated, the dielectric constant was low, the bending strength was high, and the melt viscosity was low. .
[Table 1]

[Table 2]

005 3 ]
【The invention's effect】
The electronic component using the sealing epoxy resin composition using the bifunctional OPE-2Ep of the present invention does not generate cracks when exposed to a high temperature such as solder reflow, and further has a low dielectric constant. A sealing layer is obtained. Thereby, a semiconductor device with high reliability and excellent transmission speed of the chip circuit can be provided.

Claims (4)

The composition material comprises an epoxy resin, a curing agent, an inorganic filler, and a polyphenylene ether oligomer having an epoxy group at both ends having a number average molecular weight of 700 to 3,000 represented by the structural formula (1). An epoxy resin composition for sealing.

(In the formula (1), - (OXO) - is represented by the structural formula ^{(2), R 1, R} 2, R 3, R 7, R 8 are the same or different, carbon number 6 or less of .R represents an alkyl group ^4, R ^5, R ⁶ are the same or different, hydrogen atoms frame other represents an alkyl group having 6 or less carbon atoms .- (YO) - is the structural formula (3 one of the structures defined by) or two or more kinds of structures defined by the formula (3) is obtained by a random arrangement .R ^9, R ¹⁰ are the same or different, carbon number 6 .R ^11, R ¹² having the following alkyl groups may be the same or different, hydrogen atoms coma others. a represents an alkyl group having 6 or less carbon atoms, b is not at least one is 0 .c represents an integer of 0 to 20, d is an integer from 0 to 20 at least one is not 0. j represents an integer of 0.) In the polyphenylene ether oligomer having an epoxy group at both ends represented by the structural formula (1) of the constituent material, at least R ¹ , R ² , R ^{3 of the} structural formula (2) represented by-(OXO)- , R ^7, R ⁸ is a methyl group, or a further R ^4, 1 or more methyl group of ^{R 5, R 6, - (} YO) - is structural formula (5), or formula 2. The epoxy resin composition for sealing according to claim 1, having a structure in which (4) and structural formula (5) are randomly arranged.

The content of the polyphenylene ether oligomer having an epoxy group at both ends represented by the structural formula (1) is 1 with respect to the total amount of the epoxy resin, the curing agent, and the polyphenylene ether oligomer having an epoxy group at both ends. 2. The epoxy resin composition for sealing according to claim 1, which is in a range of ˜60% by weight. The content of the inorganic filler is in the range of 15 to 95% by weight with respect to the total amount of the epoxy resin, the curing agent, the inorganic filler, and the polyphenylene ether oligomer having an epoxy group at both ends. 2. The sealing epoxy resin composition according to claim 1.