JP4128420B2 - Hardener composition for epoxy resin, epoxy resin composition using the hardener composition, and semiconductor device - Google Patents

Description

［式中、Ａｒ¹、Ａｒ²、Ａｒ³は、それぞれ、置換もしくは無置換の１価の芳香族基を表し、互いに同一であっても異なっていてもよい。Ａｒ⁴は、水酸基以外の置換基により置換もしくは無置換の２価の芳香族基を表す。］
【００１２】
（２） 前記硬化促進剤（Ｂ）が、下記一般式（２）で表されるものである、第（１）項記載の硬化剤組成物。
【化６】

［式中、Ｒ¹、Ｒ²、Ｒ³は、それぞれ、水素原子、メチル基、メトキシ基および水酸基から選択される１種を表し、互いに同一であっても異なっていてもよい。］
【００１３】
（３） 前記１分子内にフェノール性水酸基を２個以上有する化合物（Ａ）が、下記一般式（３）で表されるフェノール樹脂および下記一般式（４）で表されるフェノール樹脂の少なくとも一方を主成分とする、第（１）項ないし第（２）項のいずれかに記載の硬化剤組成物。
【化７】

［式中、Ｒ⁴〜Ｒ⁷は、それぞれ、水素原子、炭素数１〜４のアルキル基およびハロゲン原子から選択される１種を表し、互いに同一であっても異なっていてもよい。ただし、ａは、１以上の整数である。］
【化８】

［式中、Ｒ⁸〜Ｒ¹⁵は、それぞれ、水素原子、炭素数１〜４のアルキル基およびハロゲン原子から選択される１種を表し、互いに同一であっても異なっていてもよい。ただし、ｂは、１以上の整数である。］
【００１４】
（４） １分子内にエポキシ基を２個以上有する化合物と、第（１）項ないし第（３）項のいずれかに記載のエポキシ樹脂用硬化剤組成物と、必要に応じさらに１分子内にフェノール性水酸基を２個以上有する化合物とを含むことを特徴とするエポキシ樹脂組成物。
【００１５】
（５） 第（４）項に記載のエポキシ樹脂組成物の硬化物により電子部品を封止してなることを特徴とする半導体装置。
【００１６】
【発明の実施の形態】
本発明者は、前述したような問題点を解決すべく、鋭意検討を重ねた結果、特定構造のホスホニウム分子内塩が、１分子内に２個以上のフェノール性水酸基を有する化合物と、特定の比率で、かつ、該フェノール性水酸基を有する化合物の軟化点以上の温度で溶融混合することで、よりすぐれた保存安定性、流動性、および硬化性を発現することを見出し、本発明を完成するに至った。
【００１７】
以下、本発明のエポキシ樹脂用硬化剤組成物、エポキシ樹脂組成物および半導体装置の好適実施形態について説明する。
【００１８】
本実施形態のエポキシ樹脂用硬化剤組成物は、１分子内にフェノール性水酸基を２個以上有する化合物（Ａ）と、一般式（１）で表される硬化促進剤（Ｂ）とを含むものである。かかる硬化剤組成物は、エポキシ樹脂組成物に用いた場合、硬化促進剤の樹脂中への分散が向上し、局所的な反応の進行が抑制されることにより、樹脂組成物が良好な硬化性、保存性、および流動性を発揮する。
以下、各成分について順次説明する。
【００１９】
本発明で用いられる、１分子内にフェノール性水酸基を２個以上有する化合物（Ａ）は、１分子内にフェノール性水酸基を２個以上有する化合物であれば制限はなく、従来公知の化合物を用いることができる。
この化合物（Ａ）としては、例えば、フェノールノボラック樹脂、クレゾールノボラック樹脂、ビスフェノール樹脂、トリスフェノール樹脂、キシリレン変性ノボラック樹脂、テルペン変性ノボラック樹脂、ジシクロペンタジエン変性フェノール樹脂が挙げられ、これらのうちの１種または２種以上を組み合わせて用いることができる。
これらの中でも、特に、一般式（３）で表されるフェノールアラルキル樹脂および一般式（４）で表されるビフェニルアラルキル樹脂のいずれか一方または双方を主成分とするものを用いるのが好ましい。これにより、エポキシ樹脂組成物に使用した際の、成形時の流動性が向上し、特に、半導体装置の製造に用いた場合、得られた半導体装置の耐半田クラック性や耐湿信頼性が、より向上する。
【００２０】
一般式（３）で表されるフェノールアラルキル樹脂および一般式（４）で表されるビフェニルアラルキル樹脂における、置換基Ｒ⁴〜Ｒ⁷およびＲ⁸〜Ｒ¹⁵の具体例としては、それぞれ、例えば、水素原子、メチル基、エチル基、プロピル基、ブチル基、塩素原子、臭素原子等が挙げられるが、これらの中でも、特に、水素原子またはメチル基であるのが好ましい。かかるフェノール樹脂は、それ自体の溶融粘度が低いため、エポキシ樹脂組成物中に含有しても、エポキシ樹脂組成物の溶融粘度を低く保持することができ、その結果、例えば半導体装置の製造時等に、その取り扱いが容易となる。また、エポキシ樹脂組成物の硬化物（得られる半導体装置）の吸水性（吸湿性）が低減して、耐湿信頼性がより向上するとともに、耐半田クラック性もより向上する。
また、前記一般式（３）における繰り返し単位ａ、および、前記一般式（４）における繰り返し単位ｂは、それぞれ、１以上の整数であれば、特に限定されず、１〜１０程度であるのが好ましく、１〜５程度であるのがより好ましい。ａおよびｂを、それぞれ、前記範囲とすることにより、エポキシ樹脂組成物に添加した際に、好適な流動性を得ることができる。
【００２１】
本発明で用いられる、硬化促進剤（Ｂ）は、エポキシ樹脂組成物の硬化反応を促進し得る作用（機能）を有し、一般式（１）で表されるものであり、一般式（２）で表されるものであるのがより好ましい。
ここで、前記一般式（１）において、リン原子に結合する置換基Ａｒ¹、Ａｒ²、Ａｒ³は、それぞれ、置換もしくは無置換の１価の芳香族基を表し、互いに同一であっても異なっていてもよい。また、Ａｒ⁴は、水酸基以外の置換基により置換もしくは無置換の２価の芳香族基を表す。これらの置換基Ａｒ¹〜Ａｒ³の具体例としては、例えば、ナフチル基、ｐ−ターシャリーブチルフェニル基、２，６−ジメトキシフェニル基等の置換もしくは無置換の１価の芳香族基が挙げられ、Ａｒ⁴の具体例としては、フェニレン基、ビフェニレン基、ナフチレン基、または、これらにハロゲン原子、ニトロ基、シアノ基、炭素数１〜１２のアルキル基やアルコキシ基等の水酸基以外の置換基により置換された芳香族基が挙げられる。
また、前記一般式（２）における、芳香環上の置換基Ｒ¹、Ｒ²、Ｒ³は、それぞれ、水素原子、メチル基、メトキシ基および水酸基から選択される１種を表し、互いに同一であっても異なっていてもよい。
【００２２】
本発明のエポキシ樹脂用硬化剤組成物に用いる、硬化促進剤成分は、公知の手法で合成することができる。具体的には、ジアゾ化合物より誘導する手法等が利用できる。具体的には、メトキシ基を芳香環上に置換基として有する芳香族アミン化合物を、亜硝酸ナトリウム等のジアゾ化試薬と接触させてジアゾニウム化合物とし、これを第三ホスフィンと反応させて得た中間体を、ピリジン塩酸塩等の脱エーテル試薬を用いて、メトキシ基をフェノール性水酸基に変換することで得ることができる。
【００２３】
本発明のエポキシ樹脂用硬化剤組成物に用いる硬化促進剤は、分子内に分極構造を有するため、堅固な結晶構造と高い融点を有している。このような化合物に対し、フェノール性水酸基を有する化合物を溶融させると、詳細な作用機構は不明であるが、本発明者らの予想するところでは、硬化剤中のフェノール性水酸基が、硬化促進剤の構造中のベタイン構造に、静電気的作用により働きかけることで、加熱混合時に結晶構造の崩壊を促進すると考えられる。その結果、樹脂組成物中に本発明の硬化剤組成物を添加した場合に、硬化促進剤が良好に硬化剤組成物中に分散し、硬化促進剤をエポキシ樹脂組成物に直接投入した場合に比べて分散性に優れる。
【００２４】
本発明のエポキシ樹脂用硬化剤組成物への、硬化促進剤（Ｂ）の含有量（配合量）は、フェノール性水酸基を有する化合物（Ａ）１００重量部に対し、２〜５０重量部を添加することが好ましい。硬化促進剤（Ｂ）の含有量が前記範囲を上回る場合、本発明の硬化剤組成物をエポキシ樹脂組成物に添加する際に、分散性が十分に発揮されなくなり、流動性や保存安定性を損なう場合がある。また、前記範囲を下回る場合、十分な硬化性を得るために必要な添加量が極めて多くなり、エポキシ樹脂組成物にした際の、エポキシ樹脂成分と硬化剤成分のバランスが悪くなり、硬化物の特性を低下させる場合がある。
【００２５】
本発明のエポキシ樹脂用硬化剤組成物の製法としては、各成分を、フェノール性水酸基を２個以上有する化合物（Ａ）の軟化点以上の温度で、加熱混合することにより、行われる。
【００２６】
本発明において、成分（Ａ）の軟化点を測定する方法としては、具体的には、温度傾斜をつけた金属板上に、該化合物の粉末を散布し、１分後に、該化合物粉末を刷毛で払ったときに金属板に溶融付着する点の、表面温度を測定して軟化点とするコフラーベンチ法などにより測定することができる。また、成分（Ａ）として、複数の化合物を混合したものを使用する場合は、予め、これらの化合物を、均一に溶融混合した後に、前記コフラーベンチ法などにより、軟化点を測定することができる。
【００２７】
具体的に各成分を溶融混合する条件としては、成分（Ａ）の軟化点より１０〜１５０℃高い温度で、２０〜２００分間混合するのが良い。このような溶融混合には、従来公知の装置および手法を使用することができる。具体的には、各成分を混合した物を、加熱ニーダーや、加熱ロール等の器具を用い、溶融混合し、硬化剤組成物を得ることができる。
また、前記溶融混合の際に、各成分を添加する順番を、添加する化合物に応じて、適宜調整することは、何ら問題は無い。例えば、フェノール性水酸基を有する化合物（Ａ）を、初めに加熱溶融し、その後に、硬化促進剤（Ｂ）を加えることができる。また、複数のフェノール性水酸基を有する化合物を利用する場合に、予めそのうちの一成分を加熱溶融した後、その他の成分を加えることもできる。
【００２８】
本発明のエポキシ樹脂組成物は、１分子内に２個以上のエポキシ基を有する化合物と、前記エポキシ樹脂用硬化剤組成物とを含んでなるものである。また、必要により、さらに、前記エポキシ樹脂用硬化剤組成物に用いた１分子内に２個以上のフェノール性水酸基を有する化合物（Ａ）とは別に、１分子内に２個以上のフェノール性水酸基を有する化合物を用いることができる。
【００２９】
本発明に用いる１分子内に２個以上のエポキシ基を有する化合物としては、従来公知の化合物が利用できる。具体的には、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、臭素化ビスフェノール型エポキシ樹脂等のビスフェノール型エポキシ樹脂、スチルベン型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、ナフタレン型エポキシ樹脂、ジシクロペンタジエン型エポキシ樹脂、ジヒドロキシベンゼン型エポキシ樹脂など、フェノール類やフェノール樹脂、ナフトール類などの水酸基にエピクロロヒドリンを反応させて製造するエポキシ樹脂、エポキシ化合物、または、その他に、脂環式エポキシ樹脂のように、オレフィンを、過酸を用いて酸化させエポキシ化したエポキシ樹脂や、グリシジルエステル型エポキシ樹脂、グリシジルアミン型エポキシ樹脂等が挙げられ、これらのうちの１種または２種以上を組み合わせて用いることができる。
【００３０】
また、必要に応じて、さらに添加される、１分子内に２個以上のフェノール性水酸基を有する化合物としては、本発明のエポキシ樹脂用硬化剤組成物を得るために用いたものと同じ化合物でもよく、また、異なっていてもよい。この追加のフェノール性水酸基を有する化合物は、エポキシ樹脂組成物における、エポキシ基と、フェノール性水酸基の比を調整する目的で使用される。
【００３１】
本発明のエポキシ樹脂組成物における、エポキシ基とフェノール性水酸基の比は、エポキシ基１モルに対し、硬化剤組成物、および、追加で用いたフェノール性水酸基を有する化合物のフェノール性水酸基の総量が０．５〜２モル程度となるように用いるのが好ましく、０．７〜１．５モル程度となるように用いるのがより好ましい。これにより、エポキシ樹脂組成物の諸特性のバランスを好適なものに維持しつつ、諸特性がより向上する。
【００３２】
また、本発明のエポキシ樹脂組成物中には、前記の成分の他に、必要に応じて、例えば、γ−グリシドキシプロピルトリメトキシシラン等のカップリング剤、カーボンブラック等の着色剤、臭素化エポキシ樹脂、酸化アンチモン、リン化合物等の難燃剤、シリコーンオイル、シリコーンゴム等の低応力成分、天然ワックス、合成ワックス、高級脂肪酸またはその金属塩類、パラフィン等の離型剤、酸化防止剤等の各種添加剤を配合するようにしてもよい。
【００３３】
本発明のエポキシ樹脂組成物は、前記成分、および、必要に応じて、その他の添加剤等を、ミキサーを用いて、常温混合し、熱ロール、加熱ニーダー等を用いて加熱混練し、冷却、粉砕することにより得られる。
【００３４】
このようにして得られたエポキシ樹脂組成物をモールド樹脂として用いて、トランスファーモールド、コンプレッションモールド、インジェクションモールド等の成形方法で硬化成形することにより、半導体素子等の電子部品を封止する。これにより、本発明の半導体装置が得られる。
このようにして得られた本発明の半導体装置は、耐半田クラック性および耐湿信頼性に優れる。その理由は、本発明の硬化促進剤であるホスホニウム分子内塩（Ｃ）の半田条件（例えば半田リフロー工程等）における安定性に関係すると考えられる。
以上、本発明の硬化促進剤、硬化促進剤の製造方法、エポキシ樹脂組成物および半導体装置の好適実施形態について説明したが、本発明は、これに限定されるものではない。
【００３５】
【実施例】
次に、本発明の具体的実施例について説明する。
【００３６】
まず、硬化促進剤として使用する化合物Ｃ１〜Ｃ４を用意した。
[硬化促進剤の合成]
各化合物Ｃ１〜Ｃ４は、それぞれ、以下のようにして合成した。
【００３７】
（化合物Ｃ１の合成）
冷却管および撹拌装置付きのセパラブルフラスコ（容量：５００ｍＬ）に、ｏ−メトキシアニリン１２．３ｇ（０．１００ｍｏｌ）と、予め濃塩酸（３７％）２５ｍＬを２００ｍＬの純水に溶解した塩酸水溶液とを供給し、攪拌下で溶解した。
その後、セパラブルフラスコを氷冷して、内温を０〜５℃に保ちながら、亜硝酸ナトリウム７．２ｇ（０．１０４ｍｏｌ）の水溶液２０ｍＬを、前記溶液にゆっくりと滴下した。
次に、セパラブルフラスコ内に、トリフェニルホスフィン２０．０ｇ（０．０７６ｍｏｌ）の酢酸エチル溶液１５０ｍＬを滴下し、２０分攪拌した。
その後、セパラブルフラスコ内に、水酸化ナトリウム８．０ｇ（０．２００ｍｏｌ）の水溶液２０ｍＬをゆっくり滴下し、約１時間激しく攪拌した。
次に、窒素の発泡がおさまった後に、ｐＨ３以下になるまで希塩酸を加え、ヨウ化ナトリウム３０ｇ（０．２００ｍｏｌ）を添加して、生成した沈殿を濾過、乾燥し、２−メトキシフェニルトリフェニルホスホニウムヨーダイドの赤褐色結晶２９．７ｇを得た。
次に、冷却管および撹拌装置付きの５００ｍＬのセパラブルフラスコ（容量：５００ｍＬ）に、前記２−メトキシフェニルトリフェニルホスホニウムヨーダイド２９．７ｇ（０．０６０ｍｏｌ）、ピリジン塩酸塩８８．７ｇ（０．７６９ｍｏｌ）、無水酢酸１２．０ｇ（０．１１８ｍｏｌ）とを供給し、還流・攪拌下２００℃で５時間加熱した。
反応終了後、反応物を室温まで冷却し、セパラブルフラスコ内へヨウ化ナトリウム３．３ｇ（０．０２２ｍｏｌ）の水溶液２５０ｍＬを投入した。析出した固形物を濾過・乾燥し、２−ヒドロキシフェニルトリフェニルホスホニウムヨーダイドの褐色固形物２４．１ｇを得た。
次に、冷却管および撹拌装置付きのセパラブルフラスコ（容量５００ｍＬ）に、前記２−ヒドロキシフェニルトリフェニルホスホニウムヨーダイド２４．１ｇ（０．０５０ｍｏｌ）と、メタノール１００ｍＬとを供給し、攪拌下で溶解し、１０％の炭酸水素ナトリウム水溶液１２５ｍＬを、撹拌下ゆっくり攪拌した。
その後、炭酸ガスの発泡がおさまったところで、約７０℃で２分間程度加温し、冷却後、析出した結晶を濾過・乾燥し、黄褐色の結晶１５．９ｇを得た。
この化合物をＣ１とする。化合物Ｃ１を、¹Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（５）で表される目的のホスホニウム分子内塩であることが確認された。得られた化合物Ｃ１の収率は、５９％であった。
【００３８】
【化９】

【００３９】
（化合物Ｃ２の合成）
ｏ−メトキシアニリンに代わり、ｐ−メトキシアニリン１２．３ｇ（０．１００ｍｏｌ）を用いた以外は、前記化合物Ｃ１の合成と同じ手順で合成を行い、最終的に褐色の結晶１２．０ｇを得た。
この化合物をＣ２とした。化合物Ｃ２を、¹Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（６）で表される目的のホスホニウム分子内塩であることが確認された。得られた化合物Ｃ２の収率は、４５％であった。
【００４０】
【化１０】

【００４１】
（化合物Ｃ３の合成）
ｏ−メトキシアニリンに代わり、２−メトキシ−４−メチルアニリン１３．７ｇ（０．１００ｍｏｌ）を用い、また、トリフェニルホスフィンに代わり、トリ−ｐ−トリルホスフィン２３．１ｇ（０．０７６ｍｏｌ）を用いた以外は、前記化合物Ｃ１の合成と同じ手順で合成を行い、最終的に褐色の結晶１７．０ｇを得た。
この化合物をＣ３とする。化合物Ｃ３を、¹Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（７）で表される目的のホスホニウム分子内塩であることが確認された。得られた化合物Ｃ３の収率は、５５％であった。
【００４２】
【化１１】

【００４３】
（化合物Ｃ４の合成）
ｏ−メトキシアニリンに代わり、ｐ−メトキシアニリン１２．３ｇ（０．１００ｍｏｌ）を用い、また、トリフェニルホスフィンに代わり、トリ−ｐ−トリルホスフィン２３．１ｇ（０．０７６ｍｏｌ）を用いた以外は、前記化合物Ｃ１の合成と同じ手順で合成を行い、最終的に褐色の結晶１６．３ｇを得た。
この化合物をＣ４とした。化合物Ｃ４を、¹Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（８）で表される目的のホスホニウム分子内塩であることが確認された。得られた化合物Ｃ４の収率は５４％であった。
【００４４】
【化１２】

【００４５】
［硬化剤の合成］
本発明の硬化剤１〜７、および比較用の硬化剤８、９は、以下のようにして合成した。
【００４６】
（硬化剤１の合成）
１分子内に２個以上のフェノール性水酸基を有する化合物として、フェノールノボラック樹脂（軟化点９２℃、水酸基当量１０４）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｃ１の５．３重量部を、温度計および冷却管付きの５Ｌセパラブルフラスコに入れ、１２０℃のオイルバス中３０分間加熱溶融混合し、得られた溶融混合物を冷却後粉砕して、本発明の硬化剤組成物である硬化剤１を得た。
【００４７】
（硬化剤２の合成）
硬化剤１の合成において、１分子内に２個以上のフェノール性水酸基を有する化合物として、下記式９の化合物（明和化成製、ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部使用し、加熱条件を１００℃のオイルバス中４５分間に換えた他は、硬化剤１と同様に行い、本発明の硬化剤組成物である硬化剤２を得た。
【００４８】
【化１３】

【００４９】
（硬化剤３の合成）
１分子内に２個以上のフェノール性水酸基を有する化合物として、下記式１０の化合物（三井化学製、ＸＬＣ−ＬＬ。軟化点７７℃、水酸基当量１７２）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｃ２の１１．１重量部を、温度計および冷却管付きの５Ｌセパラブルフラスコに入れ、１１０℃のオイルバス中６０分間加熱溶融混合し、得られた溶融混合物を冷却後粉砕して、本発明の硬化剤組成物である硬化剤３を得た。
【００５０】
【化１４】

【００５１】
（硬化剤４の合成）
硬化剤３の合成において、１分子内に２個以上のフェノール性水酸基を有する化合物として、一般式９の化合物（明和化成製、ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部使用し、加熱条件を１００℃のオイルバス中４５分間に換えた他は、硬化剤３と同様に行い、本発明の硬化剤組成物である硬化剤４を得た。
【００５２】
（硬化剤５の合成）
１分子内に２個以上のフェノール性水酸基を有する化合物として、フェノールノボラック樹脂（軟化点９２℃、水酸基当量１０４）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｃ３の１１．１重量部を、温度計および冷却管付きの５Ｌセパラブルフラスコに入れ、１２０℃のオイルバス中３０分間加熱溶融混合し、得られた溶融混合物を冷却後粉砕して、本発明の硬化剤組成物である硬化剤５を得た。
【００５３】
（硬化剤６の合成）
硬化剤５の合成において、１分子内に２個以上のフェノール性水酸基を有する化合物として、一般式９の化合物（明和化成製、ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部使用し、加熱条件を１００℃のオイルバス中４５分間に変えたほかは、硬化剤５と同様に行い、本発明の硬化剤組成物である硬化剤６を得た。
【００５４】
（硬化剤７の合成）
１分子内に２個以上のフェノール性水酸基を有する化合物として、一般式１０の化合物（三井化学製、ＸＬＣ−ＬＬ。軟化点７７℃、水酸基当量１７２）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｃ４の１１．１重量部を、温度計および冷却管付きの５Ｌセパラブルフラスコに入れ、１１０℃のオイルバス中６０分間加熱溶融混合し、得られた溶融混合物を冷却後粉砕して、本発明の硬化剤組成物である硬化剤７を得た。
【００５５】
（硬化剤８の合成）
特許２７６５４２０号公報記載の手法により、１分子内に２個以上のフェノール性水酸基を有する化合物として、一般式１０の化合物（三井化学製、ＸＬＣ−ＬＬ。軟化点７７℃、水酸基当量１７２）を１００重量部、硬化促進剤成分として、トリフェニルホスフィンと１，４−ベンゾキノンの付加物を５．３重量部を、温度計および冷却管付きの５Ｌセパラブルフラスコに入れ、１４０℃のオイルバス中３０分間加熱した後、６０分間混合し、得られた溶融混合物を冷却後粉砕して、比較用の硬化剤である硬化剤８を得た。
【００５６】
（硬化剤９の合成）
特許２７６５４２０号公報記載の手法により、１分子内に２個以上のフェノール性水酸基を有する化合物として、フェノールノボラック樹脂（軟化点９２℃、水酸基当量１０４）を１００重量部、硬化促進剤成分として、トリフェニルホスフィンと無水マレイン酸の付加物５．３重量部を、温度計および冷却管付きの５Ｌセパラブルフラスコに入れ、１６０℃のオイルバス中３０分間加熱した後、６０分間混合し、得られた溶融混合物を冷却後粉砕して、比較用の硬化剤である硬化剤９を得た。
【００５７】
［エポキシ樹脂組成物の調製および半導体装置の製造］
（実施例１〜７、比較例１〜４）
前記硬化剤１〜９、エポキシ樹脂、および必要に応じその他の硬化剤、その他の成分を、表１に記載の比率で、室温で混合し、さらに熱ロールを用いて９５℃で８分間混練した後、冷却粉砕して、エポキシ樹脂組成物を得た。
このエポキシ樹脂組成物をモールド樹脂として用い、１００ピンＴＱＦＰ（Thin Quad Flat Package）のパッケージ（半導体装置）を８個、および、１６ピンＤＩＰ（Dual Inline Package）のパッケージ（半導体装置）を１５個、それぞれ製造した。
１００ピンＴＱＦＰは、金型温度１７５℃、注入圧力７．４ＭＰａ、硬化時間２分でトランスファーモールド成形し、１７５℃、８時間で後硬化させることにより製造した。
なお、この１００ピンＴＱＦＰのパッケージサイズは、１４×１４ｍｍ、厚み１．４ｍｍ、シリコンチップ（半導体素子）サイズは、８．０×８．０ｍｍ、リードフレームは、４２アロイ製とした。
また、１６ピンＤＩＰは、金型温度１７５℃、注入圧力６．８ＭＰａ、硬化時間２分でトランスファーモールド成形し、１７５℃、８時間で後硬化させることにより製造した。
なお、この１６ピンＤＩＰのパッケージサイズは、６．４×１９．８ｍｍ、厚み３．５ｍｍ、シリコンチップ（半導体素子）サイズは、３．５×３．５ｍｍ、リードフレームは、４２アロイ製とした。
【００５８】
［特性評価］
各実施例および各比較例で得られたエポキシ樹脂組成物の特性評価▲１▼〜▲３▼、および、各実施例および各比較例で得られた半導体装置の特性評価▲４▼および▲５▼を、それぞれ、以下のようにして行った。
▲１▼：スパイラルフロー
ＥＭＭＩ−Ｉ−６６に準じたスパイラルフロー測定用の金型を用い、金型温度１７５℃、注入圧力６．８ＭＰａ、硬化時間２分で測定した。
このスパイラルフローは、流動性のパラメータであり、数値が大きい程、流動性が良好であることを示す。
▲２▼：硬化トルク
キュラストメーター（オリエンテック（株）製、ＪＳＲキュラストメーターＩＶ ＰＳ型）を用い、１７５℃、４５秒後のトルクを測定した。
この硬化トルクは、数値が大きい程、硬化性が良好であることを示す。
▲３▼：フロー残存率
得られたエポキシ樹脂組成物を、大気中４０℃で１週間保存した後、前記▲１▼と同様にしてスパイラルフローを測定し、調製直後のスパイラルフローに対する百分率（％）を求めた。
このフロー残存率は、数値が大きい程、保存性が良好であることを示す。
▲４▼：耐半田クラック性
１００ピンＴＱＦＰを８５℃、相対湿度８５％の環境下で１６８時間放置し、その後、２６０℃の半田槽に１０秒間浸漬した。
その後、顕微鏡下に、外部クラックの発生の有無を観察し、クラック発生率＝（クラックが発生したパッケージ数）／（全パッケージ数）×１００として、百分率（％）で表示した。
また、シリコンチップとエポキシ樹脂組成物の硬化物との剥離面積の割合を、超音波探傷装置を用いて測定し、剥離率＝（剥離面積）／（シリコンチップの面積）×１００として、８個のパッケージの平均値を求め、百分率（％）で表示した。
これらのクラック発生率および剥離率は、それぞれ、数値が小さい程、耐半田クラック性が良好であることを示す。
▲５▼：耐湿信頼性
１６ピンＤＩＰに、１２５℃、相対湿度１００％の水蒸気中で、２０Ｖの電圧を印加し、断線不良を調べた。１５個のパッケージのうち８個以上に不良が出るまでの時間を不良時間とした。
なお、測定時間は、最長で５００時間とし、その時点で不良パッケージ数が８個未満であったものは、不良時間を５００時間超（＞５００）と示す。
この不良時間は、数値が大きい程、耐湿信頼性に優れることを示す。
各特性評価▲１▼〜▲５▼の結果を、表１に示す。
【００５９】
【表１】

【００６０】
表１に示すように、各実施例で得られたエポキシ樹脂組成物（本発明のエポキシ樹脂組成物）は、いずれも、硬化性、保存性、流動性が極めて良好であり、さらに、この硬化物で封止された各実施例のパッケージ（本発明の半導体装置）は、いずれも、耐半田クラック性、耐湿信頼性が良好なものであった。
これに対し、比較例１および比較例２で得られたエポキシ樹脂組成物は、いずれも、保存性に劣り、これらの比較例で得られたパッケージは、いずれも、耐半田クラック性に劣るとともに、耐湿信頼性が極めて低いものであった。また、比較例３で得られたエポキシ樹脂組成物は、硬化剤と硬化促進剤の溶融混合を行っていないため、実施例に比べ流動性と保存性に劣る。比較例４で得られたエポキシ樹脂組成物は、硬化性、保存性、流動性が極めて悪く、得られたパッケージは耐半田クラック性に劣るものであった。
【００６１】
【発明の効果】
本発明によれば、硬化促進剤を従来通りに添加した場合に比べ、硬化促進剤の分散性に優れるエポキシ樹脂用硬化剤組成物が得られ、これをエポキシ樹脂組成物に添加した際に、常温での保存性に優れ、成形時に高い流動性を得ることができる。また、該エポキシ樹脂組成物を用いて作成されたパッケージは、高温に曝された場合であっても、この硬化物に欠陥が生じるのを好適に防止することができ、良好な信頼性を発揮することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a curing agent composition for epoxy resin, an epoxy resin composition, and a semiconductor device. More specifically, a curing agent composition useful for an epoxy resin composition, an epoxy resin composition that includes such a curing agent composition, has good curability, storage stability, and fluidity, and is suitably used in the field of electrical and electronic materials. And a semiconductor device having excellent solder crack resistance and moisture resistance reliability.
[0002]
[Prior art]
As a method for obtaining a semiconductor device by sealing semiconductor elements such as IC and LSI, transfer molding of an epoxy resin composition is widely used in that it is suitable for mass production at low cost. In addition, improvement of the characteristics and reliability of the semiconductor device has been achieved by improving the epoxy resin and the phenol resin which is a curing agent.
[0003]
However, in recent market trends of downsizing, weight reduction, and high performance of electronic devices, higher integration of semiconductors has been progressing year by year, and surface mounting of semiconductor devices has been promoted. Along with this, the demand for epoxy resin compositions used for sealing semiconductor elements has become increasingly severe. For this reason, the conventional epoxy resin composition also has a problem that cannot be solved (cannot be handled).
[0004]
In recent years, materials used for sealing semiconductor devices are required to improve fast curing for the purpose of improving production efficiency and to improve storability for the purpose of improving handling during distribution and storage. It is becoming.
[0005]
Epoxy resin compositions for electrical and electronic materials are used to accelerate the curing of tertiary phosphines, quaternary phosphonium salts, imidazoles, amines, phosphobetaines, etc. for the purpose of accelerating the curing reaction of the resin during curing. Although these curing accelerators are selected so that the curing reaction proceeds at a relatively low temperature so that the curing reaction can be started quickly upon heating, when storing the epoxy resin composition at room temperature The reaction gradually proceeds.
In this way, when using a curing accelerator that causes the shelf life of the epoxy resin composition to deteriorate, strict quality control when mixing various components, storage and transportation at low temperatures, and strict control of molding conditions Is essential and handling is very complicated.
[0006]
As a technique for solving this problem, there is a technique in which phosphobetaine, which is an addition reaction product of a tertiary phosphine and a quinone, is added to an epoxy resin composition, and the resin composition by this technique has good fluidity and storage stability. (For example, refer to Patent Document 1). However, even when this curing accelerator is used, the storage stability at room temperature that has been required in recent years has not been sufficiently satisfactory, and the addition reaction product is decomposed at a high temperature. In addition, a decrease in solder resistance is a new problem.
[0007]
On the other hand, good storage stability and fluidity can be obtained by heating and mixing a phosphobetaine derivative of triorganophosphine and a phenol resin containing two or more phenolic hydroxyl groups in one molecule at a temperature above the softening point of the phenol resin. There is also a method that achieves both compatibility and curability (for example, see Patent Document 2). However, among phosphobetaine derivatives, those having a high melting point and compounds having high crystallinity have a small degree of improvement even when using this technique, and some phosphobetaine derivatives have a tendency to decompose at high temperatures, It was not a definitive technique.
[0008]
[Patent Document 1]
JP-A-9-157497 (page 4)
[Patent Document 2]
Japanese Patent No. 2765420 (page 1-2)
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide a curing agent composition capable of imparting good curability, fluidity, and storage stability to the epoxy resin composition, an epoxy resin composition having good characteristics, and solder crack resistance and moisture resistance. An object is to provide a semiconductor device having excellent reliability.
[0010]
[Means for Solving the Problems]
Such an object is achieved by the present inventions (1) to (5) below.
[0011]
(1) Consists of a compound (A) having two or more phenolic hydroxyl groups in one molecule and a curing accelerator (B) represented by the following general formula (1), and relative to 100 parts by weight of component (A) The hardening | curing agent composition for epoxy resins manufactured by heat-mixing 2-50 weight part of components (B) at the temperature more than the softening point of a component (A).
[Chemical formula 5]

[Wherein Ar ¹ , Ar ² , Ar ^Three Each represents a substituted or unsubstituted monovalent aromatic group, which may be the same as or different from each other. Ar ^Four Represents a divalent aromatic group substituted or unsubstituted by a substituent other than a hydroxyl group. ]
[0012]
(2) The curing agent composition according to item (1), wherein the curing accelerator (B) is represented by the following general formula (2).
[Chemical 6]

[Wherein R ¹ , R ² , R ^Three Each represents one selected from a hydrogen atom, a methyl group, a methoxy group and a hydroxyl group, and may be the same or different. ]
[0013]
(3) The compound (A) having two or more phenolic hydroxyl groups in one molecule is at least one of a phenol resin represented by the following general formula (3) and a phenol resin represented by the following general formula (4). The hardening | curing agent composition in any one of the (1) term | claim or the (2) term which has as a main component.
[Chemical 7]

[Wherein R ^Four ~ R ⁷ Each represents one selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms and a halogen atom, and may be the same as or different from each other. However, a is an integer greater than or equal to 1. ]
[Chemical 8]

[Wherein R ⁸ ~ R ¹⁵ Each represents one selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms and a halogen atom, and may be the same as or different from each other. However, b is an integer of 1 or more. ]
[0014]
(4) A compound having two or more epoxy groups in one molecule, a curing agent composition for epoxy resins according to any one of items (1) to (3), and, if necessary, one molecule And an epoxy resin composition comprising a compound having two or more phenolic hydroxyl groups.
[0015]
(5) A semiconductor device comprising an electronic component sealed with a cured product of the epoxy resin composition according to item (4).
[0016]
DETAILED DESCRIPTION OF THE INVENTION
As a result of intensive studies in order to solve the above-described problems, the present inventor has found that a phosphonium inner salt having a specific structure contains a compound having two or more phenolic hydroxyl groups in one molecule, It has been found that, by mixing at a ratio and at a temperature equal to or higher than the softening point of the compound having a phenolic hydroxyl group, excellent storage stability, fluidity, and curability are exhibited, and the present invention is completed. It came to.
[0017]
Hereinafter, preferred embodiments of the curing agent composition for epoxy resin, the epoxy resin composition, and the semiconductor device of the present invention will be described.
[0018]
The hardening | curing agent composition for epoxy resins of this embodiment contains the compound (A) which has 2 or more of phenolic hydroxyl groups in 1 molecule, and the hardening accelerator (B) represented by General formula (1). . Such a curing agent composition, when used in an epoxy resin composition, improves the dispersion of the curing accelerator in the resin and suppresses the progress of local reaction, so that the resin composition has good curability. , Storability and fluidity.
Hereinafter, each component will be sequentially described.
[0019]
The compound (A) having two or more phenolic hydroxyl groups in one molecule used in the present invention is not limited as long as it is a compound having two or more phenolic hydroxyl groups in one molecule, and a conventionally known compound is used. be able to.
Examples of the compound (A) include phenol novolak resin, cresol novolak resin, bisphenol resin, trisphenol resin, xylylene modified novolak resin, terpene modified novolak resin, and dicyclopentadiene modified phenol resin. Species or a combination of two or more can be used.
Among these, it is particularly preferable to use a resin mainly composed of one or both of the phenol aralkyl resin represented by the general formula (3) and the biphenyl aralkyl resin represented by the general formula (4). Thereby, the fluidity at the time of molding when used in an epoxy resin composition is improved, and particularly when used for manufacturing a semiconductor device, the solder crack resistance and moisture resistance reliability of the obtained semiconductor device are more improved. improves.
[0020]
Substituent R in the phenol aralkyl resin represented by the general formula (3) and the biphenyl aralkyl resin represented by the general formula (4) ^Four ~ R ⁷ And R ⁸ ~ R ¹⁵ Specific examples of these include, for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a chlorine atom, and a bromine atom. Among these, a hydrogen atom or a methyl group is particularly preferable. Is preferred. Since such a phenol resin has a low melt viscosity per se, even when contained in the epoxy resin composition, the melt viscosity of the epoxy resin composition can be kept low. Moreover, the handling becomes easy. In addition, the water absorption (hygroscopicity) of the cured product of the epoxy resin composition (obtained semiconductor device) is reduced, and the moisture resistance reliability is further improved and the solder crack resistance is further improved.
The repeating unit a in the general formula (3) and the repeating unit b in the general formula (4) are not particularly limited as long as they are integers of 1 or more, and are about 1 to 10. Preferably, it is about 1-5. By setting each of a and b within the above ranges, suitable fluidity can be obtained when added to the epoxy resin composition.
[0021]
The curing accelerator (B) used in the present invention has an action (function) that can accelerate the curing reaction of the epoxy resin composition, and is represented by the general formula (1). ) Is more preferable.
Here, in the general formula (1), the substituent Ar bonded to the phosphorus atom ¹ , Ar ² , Ar ^Three Each represents a substituted or unsubstituted monovalent aromatic group, which may be the same as or different from each other. Ar ^Four Represents a divalent aromatic group substituted or unsubstituted by a substituent other than a hydroxyl group. These substituents Ar ¹ ~ Ar ^Three Specific examples of these include, for example, substituted or unsubstituted monovalent aromatic groups such as a naphthyl group, a p-tertiarybutylphenyl group, and a 2,6-dimethoxyphenyl group, and Ar ^Four Specific examples of these include a phenylene group, a biphenylene group, a naphthylene group, or a substituent other than a hydroxyl group such as a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group. An aromatic group is mentioned.
In the general formula (2), the substituent R on the aromatic ring ¹ , R ² , R ^Three Each represents one selected from a hydrogen atom, a methyl group, a methoxy group and a hydroxyl group, and may be the same or different.
[0022]
The curing accelerator component used in the epoxy resin curing agent composition of the present invention can be synthesized by a known method. Specifically, a method derived from a diazo compound can be used. Specifically, an aromatic amine compound having a methoxy group as a substituent on the aromatic ring is brought into contact with a diazotizing reagent such as sodium nitrite to form a diazonium compound, which is obtained by reacting with a tertiary phosphine. The body can be obtained by converting a methoxy group to a phenolic hydroxyl group using a deethering reagent such as pyridine hydrochloride.
[0023]
Since the curing accelerator used for the epoxy resin curing agent composition of the present invention has a polarization structure in the molecule, it has a solid crystal structure and a high melting point. When a compound having a phenolic hydroxyl group is melted with respect to such a compound, the detailed mechanism of action is unknown, but the inventors expect that the phenolic hydroxyl group in the curing agent is a curing accelerator. By acting on the betaine structure in the structure by electrostatic action, it is considered that the collapse of the crystal structure is promoted during heating and mixing. As a result, when the curing agent composition of the present invention is added to the resin composition, the curing accelerator is well dispersed in the curing agent composition, and when the curing accelerator is directly added to the epoxy resin composition. Excellent dispersibility.
[0024]
The content (blending amount) of the curing accelerator (B) in the epoxy resin curing agent composition of the present invention is 2 to 50 parts by weight based on 100 parts by weight of the compound (A) having a phenolic hydroxyl group. It is preferable to do. When the content of the curing accelerator (B) exceeds the above range, when adding the curing agent composition of the present invention to the epoxy resin composition, the dispersibility is not sufficiently exhibited, and the fluidity and storage stability are improved. It may be damaged. Further, when the amount is less than the above range, the amount of addition necessary for obtaining sufficient curability becomes extremely large, and the balance between the epoxy resin component and the curing agent component when the epoxy resin composition is obtained deteriorates, The characteristics may be deteriorated.
[0025]
The production method of the epoxy resin curing agent composition of the present invention is carried out by heating and mixing each component at a temperature equal to or higher than the softening point of the compound (A) having two or more phenolic hydroxyl groups.
[0026]
In the present invention, as a method for measuring the softening point of the component (A), specifically, a powder of the compound is sprayed on a metal plate with a temperature gradient, and after 1 minute, the compound powder is brushed. It can be measured by the Kofler bench method, etc., which measures the surface temperature of the point that melts and adheres to the metal plate when it is used to make the softening point. Moreover, when using what mixed several compounds as a component (A), after these compounds are melt-mixed uniformly previously, a softening point can be measured by the said Kofler bench method etc. .
[0027]
Specifically as conditions for melt-mixing each component, it is good to mix for 20-200 minutes at the temperature 10-150 degreeC higher than the softening point of a component (A). A conventionally well-known apparatus and method can be used for such melt mixing. Specifically, a product obtained by mixing each component can be melt-mixed using an apparatus such as a heating kneader or a heating roll to obtain a curing agent composition.
In addition, there is no problem in appropriately adjusting the order of adding each component in accordance with the compound to be added during the melt mixing. For example, the compound (A) having a phenolic hydroxyl group can be first heated and melted, and then the curing accelerator (B) can be added. Moreover, when utilizing the compound which has several phenolic hydroxyl groups, after heat-melting one component of them previously, another component can also be added.
[0028]
The epoxy resin composition of the present invention comprises a compound having two or more epoxy groups in one molecule and the epoxy resin curing agent composition. In addition, if necessary, in addition to the compound (A) having two or more phenolic hydroxyl groups in one molecule used in the epoxy resin curing agent composition, two or more phenolic hydroxyl groups in one molecule. A compound having can be used.
[0029]
A conventionally known compound can be used as the compound having two or more epoxy groups in one molecule used in the present invention. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol type epoxy resin such as brominated bisphenol type epoxy resin, stilbene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthalene type epoxy Resin, dicyclopentadiene type epoxy resin, dihydroxybenzene type epoxy resin, etc., epoxy resin produced by reacting epichlorohydrin with hydroxyl group such as phenols, phenol resin, naphthols, epoxy compound, or other Examples of cyclic epoxy resins include epoxy resins obtained by oxidizing olefins with peracids and epoxidizing, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, and the like. It can be used singly or in combination of two or more.
[0030]
Further, if necessary, the compound having two or more phenolic hydroxyl groups in one molecule may be the same compound as used to obtain the epoxy resin curing agent composition of the present invention. Well, it may be different. The compound having an additional phenolic hydroxyl group is used for the purpose of adjusting the ratio of the epoxy group to the phenolic hydroxyl group in the epoxy resin composition.
[0031]
In the epoxy resin composition of the present invention, the ratio of the epoxy group to the phenolic hydroxyl group is such that the total amount of the phenolic hydroxyl group of the curing agent composition and the compound having the phenolic hydroxyl group additionally used is 1 mol of the epoxy group. It is preferable to use it so that it may become about 0.5-2 mol, and it is more preferable to use it so that it may become about 0.7-1.5 mol. Thereby, various characteristics improve more, maintaining the balance of the various characteristics of an epoxy resin composition to a suitable thing.
[0032]
Further, in the epoxy resin composition of the present invention, in addition to the above components, for example, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a colorant such as carbon black, bromine Such as flame retardants such as epoxy resin, antimony oxide, phosphorus compounds, low stress components such as silicone oil, silicone rubber, natural wax, synthetic wax, higher fatty acids or their metal salts, mold release agents such as paraffin, antioxidants, etc. You may make it mix | blend various additives.
[0033]
The epoxy resin composition of the present invention is mixed with the above components and, if necessary, other additives at room temperature using a mixer, heated and kneaded using a hot roll, a heating kneader, etc., cooled, It is obtained by grinding.
[0034]
The epoxy resin composition thus obtained is used as a mold resin to cure and mold an electronic component such as a semiconductor element by a molding method such as transfer molding, compression molding, or injection molding. Thereby, the semiconductor device of the present invention is obtained.
The semiconductor device of the present invention thus obtained is excellent in solder crack resistance and moisture resistance reliability. The reason is considered to be related to the stability of the phosphonium inner salt (C), which is the curing accelerator of the present invention, in the solder conditions (for example, solder reflow process).
The preferred embodiments of the curing accelerator, the method for producing the curing accelerator, the epoxy resin composition, and the semiconductor device of the present invention have been described above, but the present invention is not limited thereto.
[0035]
【Example】
Next, specific examples of the present invention will be described.
[0036]
First, compounds C1 to C4 used as curing accelerators were prepared.
[Synthesis of curing accelerator]
Each of the compounds C1 to C4 was synthesized as follows.
[0037]
(Synthesis of Compound C1)
In a separable flask (capacity: 500 mL) equipped with a condenser and a stirrer, an aqueous hydrochloric acid solution prepared by dissolving 12.3 g (0.100 mol) of o-methoxyaniline and 25 mL of concentrated hydrochloric acid (37%) in 200 mL of pure water in advance Was dissolved under stirring.
Thereafter, the separable flask was ice-cooled, and 20 mL of an aqueous solution of 7.2 g (0.104 mol) of sodium nitrite was slowly dropped into the solution while keeping the internal temperature at 0 to 5 ° C.
Next, 150 mL of an ethyl acetate solution of 20.0 g (0.076 mol) of triphenylphosphine was dropped into the separable flask and stirred for 20 minutes.
Thereafter, 20 mL of an aqueous solution of 8.0 g (0.200 mol) of sodium hydroxide was slowly dropped into the separable flask and stirred vigorously for about 1 hour.
Next, after the bubbling of nitrogen has subsided, dilute hydrochloric acid is added until the pH becomes 3 or less, 30 g (0.200 mol) of sodium iodide is added, and the resulting precipitate is filtered and dried to give 2-methoxyphenyltriphenylphosphonium. 29.7 g of reddish brown crystals of iodide were obtained.
Next, in a 500 mL separable flask (capacity: 500 mL) equipped with a condenser and a stirrer, 29.7 g (0.060 mol) of 2-methoxyphenyltriphenylphosphonium iodide and 88.7 g of pyridine hydrochloride (0. 769 mol) and 12.0 g (0.118 mol) of acetic anhydride, and heated at 200 ° C. for 5 hours under reflux and stirring.
After completion of the reaction, the reaction product was cooled to room temperature, and 250 mL of an aqueous solution of 3.3 g (0.022 mol) of sodium iodide was charged into the separable flask. The precipitated solid was filtered and dried to obtain 24.1 g of a brown solid of 2-hydroxyphenyltriphenylphosphonium iodide.
Next, 24.1 g (0.050 mol) of 2-hydroxyphenyltriphenylphosphonium iodide and 100 mL of methanol are supplied to a separable flask (capacity 500 mL) equipped with a condenser and a stirring device, and dissolved under stirring. Then, 125 mL of 10% aqueous sodium hydrogen carbonate solution was slowly stirred with stirring.
Thereafter, when the bubbling of carbon dioxide gas stopped, the mixture was heated at about 70 ° C. for about 2 minutes, and after cooling, the precipitated crystals were filtered and dried to obtain 15.9 g of tan crystals.
This compound is designated as C1. Compound C1 ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed to be the target phosphonium inner salt represented by the following formula (5). The yield of the obtained compound C1 was 59%.
[0038]
[Chemical 9]

[0039]
(Synthesis of Compound C2)
The synthesis was performed in the same procedure as the synthesis of Compound C1, except that 12.3 g (0.100 mol) of p-methoxyaniline was used instead of o-methoxyaniline, and finally 12.0 g of brown crystals were obtained. .
This compound was designated C2. Compound C2 ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed to be the target phosphonium inner salt represented by the following formula (6). The yield of the obtained compound C2 was 45%.
[0040]
[Chemical Formula 10]

[0041]
(Synthesis of Compound C3)
Instead of o-methoxyaniline, 2-methoxy- 4 -The same procedure as the synthesis of Compound C1 except that 13.7 g (0.100 mol) of methylaniline was used and 23.1 g (0.076 mol) of tri-p-tolylphosphine was used instead of triphenylphosphine. The final synthesis was 17.0 g of brown crystals.
This compound is referred to as C3. Compound C3 ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed to be the target phosphonium inner salt represented by the following formula (7). The yield of the obtained compound C3 was 55%.
[0042]
Embedded image

[0043]
(Synthesis of Compound C4)
p-methoxyaniline was used instead of o-methoxyaniline, 12.3 g (0.100 mol), and triphenylphosphine was used instead of tri-p-tolylphosphine, 23.1 g (0.076 mol). The synthesis was carried out in the same procedure as the synthesis of Compound C1, and finally 16.3 g of brown crystals were obtained.
This compound was designated as C4. Compound C4 ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed to be the target phosphonium inner salt represented by the following formula (8). The yield of the obtained compound C4 was 54%.
[0044]
Embedded image

[0045]
[ Hardener Synthesis]
The curing agents 1 to 7 of the present invention and the comparative curing agents 8 and 9 were synthesized as follows.
[0046]
(Synthesis of curing agent 1)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of a phenol novolak resin (softening point 92 ° C., hydroxyl group equivalent 104) and a curing accelerator component, 5.3 of the compound C1 obtained above. Part by weight is put into a 5 L separable flask equipped with a thermometer and a cooling tube, heated and melted and mixed for 30 minutes in an oil bath at 120 ° C., and the resulting molten mixture is cooled and pulverized to obtain the curing agent composition of the present invention. A curing agent 1 was obtained.
[0047]
(Synthesis of curing agent 2)
In the synthesis of the curing agent 1, 100 parts by weight of a compound represented by the following formula 9 (Maywa Kasei, MEH-7851SS, softening point 68 ° C., hydroxyl group equivalent 199) as a compound having two or more phenolic hydroxyl groups in one molecule. The curing agent 2 which is the curing agent composition of the present invention was obtained in the same manner as the curing agent 1 except that the heating conditions were changed to 45 minutes in an oil bath at 100 ° C. for 45 minutes.
[0048]
Embedded image

[0049]
(Synthesis of curing agent 3)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of a compound of the following formula 10 (manufactured by Mitsui Chemicals, XLC-LL, softening point 77 ° C., hydroxyl group equivalent 172), a curing accelerator component, 11.1 parts by weight of the compound C2 obtained above is put into a 5 L separable flask equipped with a thermometer and a cooling tube, heated and melted and mixed for 60 minutes in an oil bath at 110 ° C., and the resulting molten mixture is cooled and ground. And the hardening | curing agent 3 which is a hardening | curing agent composition of this invention was obtained.
[0050]
Embedded image

[0051]
(Synthesis of curing agent 4)
In the synthesis of the curing agent 3, as a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of the compound of the general formula 9 (Maywa Kasei Co., Ltd., MEH-7851SS, softening point 68 ° C., hydroxyl group equivalent 199) The curing agent 4 which is the curing agent composition of the present invention was obtained in the same manner as the curing agent 3 except that the heating conditions were changed to 45 minutes in an oil bath at 100 ° C.
[0052]
(Synthesis of curing agent 5)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of phenol novolak resin (softening point 92 ° C., hydroxyl group equivalent 104) and a curing accelerator component, 11.1 of compound C3 obtained above Part by weight is put into a 5 L separable flask equipped with a thermometer and a cooling tube, heated and melted and mixed for 30 minutes in an oil bath at 120 ° C., and the resulting molten mixture is cooled and pulverized to obtain the curing agent composition of the present invention. Curing agent 5 was obtained.
[0053]
(Synthesis of curing agent 6)
In the synthesis of the curing agent 5, 100 parts by weight of the compound of the general formula 9 (Maywa Kasei, MEH-7851SS, softening point 68 ° C., hydroxyl group equivalent 199) as a compound having two or more phenolic hydroxyl groups in one molecule. The curing agent 6 as the curing agent composition of the present invention was obtained in the same manner as the curing agent 5 except that the heating conditions were changed to 45 minutes in an oil bath at 100 ° C. for 45 minutes.
[0054]
(Synthesis of curing agent 7)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of a compound of general formula 10 (manufactured by Mitsui Chemicals, XLC-LL, softening point 77 ° C., hydroxyl group equivalent 172), a curing accelerator component, 11.1 parts by weight of the compound C4 obtained above is placed in a 5 L separable flask equipped with a thermometer and a cooling tube, heated and melted and mixed in a 110 ° C. oil bath for 60 minutes, and the resulting molten mixture is cooled and pulverized. Thus, a curing agent 7 which is the curing agent composition of the present invention was obtained.
[0055]
(Synthesis of curing agent 8)
As a compound having two or more phenolic hydroxyl groups in one molecule by the method described in Japanese Patent No. 2765420, a compound of general formula 10 (manufactured by Mitsui Chemicals, XLC-LL, softening point 77 ° C., hydroxyl group equivalent 172) is 100. Part by weight, 5.3 parts by weight of an adduct of triphenylphosphine and 1,4-benzoquinone as a curing accelerator component was placed in a 5 L separable flask equipped with a thermometer and a cooling tube, and placed in an oil bath at 140 ° C. 30 After heating for 60 minutes, the mixture was mixed for 60 minutes, and the resulting molten mixture was cooled and pulverized to obtain a curing agent 8 as a comparative curing agent.
[0056]
(Synthesis of curing agent 9)
According to the method described in Japanese Patent No. 2765420, 100 parts by weight of a phenol novolac resin (softening point 92 ° C., hydroxyl group equivalent 104) as a compound having two or more phenolic hydroxyl groups in one molecule, 5.3 parts by weight of an adduct of phenylphosphine and maleic anhydride was placed in a 5 L separable flask equipped with a thermometer and a condenser tube, heated in an oil bath at 160 ° C. for 30 minutes, and then mixed for 60 minutes. The molten mixture was cooled and pulverized to obtain a curing agent 9 as a comparative curing agent.
[0057]
[Preparation of epoxy resin composition and manufacture of semiconductor device]
(Examples 1-7, Comparative Examples 1-4)
The curing agents 1 to 9, epoxy resin, and other curing agents as necessary, and other components were mixed at a ratio shown in Table 1 at room temperature, and further kneaded at 95 ° C. for 8 minutes using a hot roll. Thereafter, the mixture was cooled and pulverized to obtain an epoxy resin composition.
Using this epoxy resin composition as a mold resin, eight 100-pin TQFP (Thin Quad Flat Package) packages (semiconductor devices) and 15 16-pin DIP (Dual Inline Package) packages (semiconductor devices), Each was manufactured.
The 100-pin TQFP was manufactured by transfer molding at a mold temperature of 175 ° C., an injection pressure of 7.4 MPa and a curing time of 2 minutes, and post-cured at 175 ° C. for 8 hours.
The package size of the 100-pin TQFP was 14 × 14 mm, the thickness was 1.4 mm, the silicon chip (semiconductor element) size was 8.0 × 8.0 mm, and the lead frame was made of 42 alloy.
The 16-pin DIP was manufactured by transfer molding at a mold temperature of 175 ° C., an injection pressure of 6.8 MPa and a curing time of 2 minutes, and post-cured at 175 ° C. for 8 hours.
The package size of the 16-pin DIP is 6.4 × 19.8 mm, the thickness is 3.5 mm, the silicon chip (semiconductor element) size is 3.5 × 3.5 mm, and the lead frame is made of 42 alloy. .
[0058]
[Characteristic evaluation]
Characteristic evaluation (1) to (3) of the epoxy resin composition obtained in each example and each comparative example, and characteristic evaluation (4) and (5) of the semiconductor device obtained in each example and each comparative example ▼ was performed as follows.
(1): Spiral flow
Using a spiral flow measurement mold according to EMMI-I-66, measurement was performed at a mold temperature of 175 ° C., an injection pressure of 6.8 MPa, and a curing time of 2 minutes.
This spiral flow is a parameter of fluidity, and the larger the value, the better the fluidity.
(2): Curing torque
The torque after 175 degreeC and 45 second was measured using the curast meter (Orientec Co., Ltd. product, JSR curast meter IV PS type).
This hardening torque shows that curability is so favorable that a numerical value is large.
(3): Flow remaining rate
The obtained epoxy resin composition was stored in the atmosphere at 40 ° C. for 1 week, and then the spiral flow was measured in the same manner as in the above (1) to determine the percentage (%) with respect to the spiral flow immediately after preparation.
This flow residual ratio indicates that the larger the numerical value, the better the storage stability.
(4) Solder crack resistance
The 100-pin TQFP was left for 168 hours in an environment of 85 ° C. and 85% relative humidity, and then immersed in a solder bath at 260 ° C. for 10 seconds.
Thereafter, the presence or absence of the occurrence of external cracks was observed under a microscope, and the percentage was expressed as crack generation rate = (number of packages in which cracks occurred) / (total number of packages) × 100.
Further, the ratio of the peeled area between the silicon chip and the cured epoxy resin composition was measured using an ultrasonic flaw detector, and the peel rate = (peeled area) / (silicon chip area) × 100. The average value of the package was obtained and expressed as a percentage (%).
These crack generation rate and peel rate indicate that the smaller the numerical value, the better the solder crack resistance.
(5): Moisture resistance reliability
A voltage of 20 V was applied to the 16-pin DIP in water vapor at 125 ° C. and a relative humidity of 100%, and the disconnection failure was examined. The time until a defect appears in 8 or more of the 15 packages was defined as a defect time.
Note that the measurement time is 500 hours at the longest, and when the number of defective packages is less than 8 at that time, the defective time is indicated as over 500 hours (> 500).
This failure time indicates that the larger the numerical value, the better the moisture resistance reliability.
Table 1 shows the results of the characteristic evaluations (1) to (5).
[0059]
[Table 1]

[0060]
As shown in Table 1, each of the epoxy resin compositions (epoxy resin compositions of the present invention) obtained in each example has extremely good curability, storage stability, and fluidity. Each of the packages of the examples (semiconductor device of the present invention) sealed with an object had good solder crack resistance and moisture resistance reliability.
On the other hand, the epoxy resin compositions obtained in Comparative Example 1 and Comparative Example 2 are both poor in storage stability, and the packages obtained in these Comparative Examples are both poor in solder crack resistance. The moisture resistance reliability was extremely low. Moreover, since the epoxy resin composition obtained in Comparative Example 3 is not melt-mixed with the curing agent and the curing accelerator, it is inferior in fluidity and storage stability as compared with the Examples. The epoxy resin composition obtained in Comparative Example 4 was extremely poor in curability, storage stability and fluidity, and the resulting package was inferior in solder crack resistance.
[0061]
【The invention's effect】
According to the present invention, a curing agent composition for an epoxy resin excellent in dispersibility of the curing accelerator is obtained as compared with the case where the curing accelerator is added as usual, and when this is added to the epoxy resin composition, Excellent storage stability at room temperature and high fluidity during molding. Moreover, even when the package made using the epoxy resin composition is exposed to a high temperature, it is possible to suitably prevent defects in the cured product and to exhibit good reliability. can do.

Claims (5)

It consists of a compound (A) having two or more phenolic hydroxyl groups in one molecule and a curing accelerator (B) represented by the general formula (1). ) A curing agent composition for epoxy resin produced by heating and mixing 2 to 50 parts by weight at a temperature equal to or higher than the softening point of component (A).

[Wherein Ar ¹ , Ar ² and Ar ³ each represent a substituted or unsubstituted monovalent aromatic group, and may be the same or different from each other. Ar ⁴ represents a divalent aromatic group substituted or unsubstituted by a substituent other than a hydroxyl group. ] The hardening | curing agent composition for epoxy resins of Claim 1 whose hardening accelerator (B) is what is represented by General formula (2).

[Wherein R ¹ , R ² and R ³ each represent one selected from a hydrogen atom, a methyl group, a methoxy group and a hydroxyl group, and may be the same or different from each other. ] The compound (A) having two or more phenolic hydroxyl groups in one molecule is mainly composed of at least one of the phenol resin represented by the general formula (3) and the phenol resin represented by the general formula (4). The hardening | curing agent composition for epoxy resins of Claim 1 or 2.

[Wherein, R ^{4 to} R ⁷ each represents one selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a halogen atom, and may be the same or different from each other; Is an integer of 1 or more. ]

[Wherein, R ^{8 to} R ¹⁵ each represent one selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a halogen atom, and may be the same or different from each other; Is an integer of 1 or more. ] The epoxy resin composition characterized by including the compound which has 2 or more of epoxy groups in 1 molecule, and the hardening | curing agent composition for epoxy resins in any one of Claims 1 thru | or 3. An electronic component is sealed with a cured product of the epoxy resin composition according to claim 4.