JP2004124023A - Hardener composition for epoxy resin, epoxy resin composition using the hardener and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hardener composition for an epoxy resin composition having good shelf stability, hardenability and flowability, the epoxy resin composition using it and a semiconductor device superior in solder crack resistance and moisture resistance reliability. <P>SOLUTION: This hardener composition for the epoxy resin comprises a compound (A) having 2 or more phenolic hydroxy groups in a molecule and a hardening accelerator (B) represented by formula (1). The hardener composition is manufactured by heating and mixing the component (A) of 100 pts. wt. and the component (B) of 2-50 pts. wt. at a temperature not lower than a softening point of the component (A). The epoxy resin composition containing the hardener composition and a semiconductor device encapsulated by the epoxy resin composition are provided. <P>COPYRIGHT: (C)2004,JPO

Description

［式中、Ｒ_１，Ｒ_２およびＲ_３は、それぞれ、置換もしくは無置換の１価の芳香族基、または、置換もしくは無置換の１価のアルキル基を表し、互いに同一であっても異なっていてもよい。Ａｒ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。Ａは、芳香環または複素環を含むｐ価の有機基を表し、ｐは２〜８の整数、ｑは０〜２の値を表す。］
【００１５】
（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）項記載のエポキシ樹脂用硬化剤組成物。
【化８】

［式中、Ｒ_４，Ｒ_５およびＲ_６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種を示し、互いに同一であっても異なっていてもよい。Ａは、芳香環または複素環を含むｐ価の有機基を表し、ｐは２〜８の整数、ｑは０〜２の値を表す。］
【００１６】
（３）　前記硬化促進剤（Ｂ）が、下記一般式（３）または一般式（４）で表されるものである、第（１）項記載のエポキシ樹脂用硬化剤組成物。
【化９】

【化１０】

［式中、Ｒ_７，Ｒ_８およびＲ_９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種を示し、互いに同一であっても異なっていてもよい。Ｒ_１０，Ｒ_１１，Ｒ_１２およびＲ_１３は水素原子またはハロゲン原子または炭素数１〜６で構成される１価の有機基を表す。Ｘは単結合、またはエーテル基、スルホン基、スルフィド基、カルボニル基から選ばれる２価置換基、または炭素原子数１〜１３で構成される２価の有機基を表す。ｑは、０〜２の値を表す。］
【００１７】
（４）　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）は、下記一般式（５）で表されるフェノール樹脂および下記一般式（６）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（３）項のいずれかに記載のエポキシ樹脂用硬化剤組成物。
【化１１】

［式中、Ｒ_１４〜Ｒ_１７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１２】

［式中、Ｒ_１８〜Ｒ_２５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。］
【００１８】
（５）　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（４）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。
【００１９】
（６）　第（５）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。
【００２０】
【発明の実施の形態】
本発明者は、前記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化合物からなる硬化促進剤が、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、前記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、より優れた保存安定性、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。
【００２１】
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。
【００２２】
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では、エポキシ樹脂組成物に用いた場合、良好な硬化性、保存性、および流動性を発揮する。
【００２３】
以下、各成分について順次説明する。
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その種類に制限はなく、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（５）で表されるフェノールアラルキル樹脂および一般式（６）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。
【００２４】
一般式（５）および一般式（６）における置換基Ｒ_１４〜Ｒ_１７およびＲ_１８〜Ｒ_２５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（５）中におけるａ、および、前記一般式（６）中における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。
【００２５】
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、前記一般式（１）で表されるものであり、前記一般式（２）で表されるものであるのが好ましく、さらに好ましくは前記一般式（３）または前記一般式（４）で表されるものである。
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Ｒ^１，Ｒ^２およびＲ^３の具体例としては、例えば、ベンジル基、メチル基、エチル基、ｎ−ブチル基、ｎ−オクチル基、シクロヘキシル基、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、フェニル基、メチルフェニル基の各種異性体、メトキシフェニル基の各種異性体、ヒドロキシフェニル基の各種異性体等が挙げられるが、これらの中でも、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、フェニル基、メチルフェニル基の各種異性体、メトキシフェニル基の各種異性体、ヒドロキシフェニル基の各種異性体等の置換もしくは無置換の１価の芳香族基であるのが好ましく、特にフェニル基、メチルフェニル基の各種異性体、メトキシフェニル基の各種異性体、ヒドロキシフェニル基の各種異性体等であるのが好ましい。
また、前記一般式（１）において、Ａｒ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。
このＡｒ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。
【００２６】
また、前記一般式（１）ないし一般式（４）において、ホスホニウム分子化合物を形成するもう一方のアニオン成分は、フェノール化合物からなり、フェノール化合物としては、ビスフェノールＡ（２，２−ビス（４−ヒドロキシフェニル）プロパン）、ビスフェノールＦ（４，４−メチレンビスフェノール、２，４−メチレンビスフェノール、２，２−メチレビスフェノール）、ビスフェノールＳ（２，２−ビス（４−ヒドロキシフェニル）スルホン）、ビスフェノールＥ（４，４−エチリデンビスフェノール）、ビスフェノールフルオレン（４，４−（９Ｈ−フルオレン−９−イリデン）ビスフェノール）４，４−メチリデンビス（２，６−ジメチルフェノール）、ビス（４−ヒドロキシフェニル）メタノンなどのビスフェノール類、４，４−ビフェノール、２，２−ビフェノール、３，３，５，５−テトラメチルビフェノールなどのビフェノール類、ヒドロキノン、レゾシノール、カテコール、２，６−ジヒドロキシナフタレン、１，４−ジヒドロキシナフタレン、２，３−ジヒドロキシナフタレン、１，６−ジヒドロキシナフタレン、１，１−ビ−２−ナフトール、１，４−ジヒドロキシアントラキノンなどが例示されるが硬化物物性の点で、ｐが２である２価のフェノール化合物でありｑは０．５〜２であることが好ましく、ビスフェノールＡ、ビスフェノールＦ（４，４−メチレンビスフェノール、２，４−メチレンビスフェノール、２，２−メチレビスフェノールや、本州化学製ビスフェノールＦ−Ｄのようなこれらの異性体混合物を含む）、ビスフェノールＳ、４，４−ビフェノール、２，６−ジヒドロキシナフタレンが、より好ましい。
総じて、前記一般式（１）において、置換基Ｒ^１，Ｒ^２およびＲ^３ならびにＡｒの組み合わせとしては、置換基Ｒ^１，Ｒ^２およびＲ^３が、それぞれフェニル基であり、Ａｒがフェニレン基であるものが好適である。このものは、熱安定性、硬化促進能に特に優れ、製造コストが安価である。
【００２７】
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。ここで、本発明の硬化促進剤であるホスホニウム分子化合物の製造方法の一例について、下記化１３を参照しつつ説明する。
【００２８】
【化１３】

［式中、Ｒは、水素原子、または、適宜選択される残基を表す。］
【００２９】
工程［１］
まず、例えば、アルコキシ置換芳香族アミンを、酸性条件下で亜硝酸ナトリウム等のジアゾ化試薬と反応させてジアゾニウム塩化する。用いるアルコキシ置換芳香族アミンとしては、ｏ−メトキシアニリン、ｍ−メトキシアニリン、ｐ−メトキシアニリン、２−メトキシ−５−メチルアニリなどが挙げられる。
次いで、このジアゾニウム塩と第三ホスフィン類とを接触させる。これにより、Ｎ_２を脱離させるとともに、第三ホスフィンのリン原子にアルコキシ置換芳香族基を導入して、第四ホスホニウム塩を生成させる。すなわち、本工程［１］において、第三ホスフィンとジアゾニウム塩が有するジアゾニウム基との置換が起こる。用いる第三ホスフィン類としては、トリフェニルホスフィン、トリ−ｐ−トリルホスフィン、トリ（４−メトキシフェニル）ホスフィンなどが挙げられる。
【００３０】
この置換反応は、好ましくはアルカリ存在下で行われる。これにより、置換反応を、より効率よく進行させることができる。用いるアルカリとしては、特に限定されないが、例えば、水酸化ナトリウム、水酸化カリウム、水酸化カルシウム、炭酸ナトリウム、炭酸カリウム、炭酸水素ナトリウム、水素化ナトリウム、水素化リチウム、水素化カルシウム、水素化アルミニウムリチウムのような無機塩基、トリエチルアミン、トリプロピルアミン、トリブチルアミン、ピリジン、ピペリジン、ジアミノエタン、ジアミノプロパン、ジアミノブタン、ジアミノペンタン、ジアミノヘキサン、ジアミノオクタン、トリエタノールアミンのような有機塩基等が挙げられ、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。
【００３１】
置換反応における反応温度は、特に限定されないが、−１０〜１０℃程度であるのが好ましく、０〜５℃程度であるのが、より好ましい。反応温度が低すぎると、置換反応が十分に進行しない場合があり、一方、反応温度が高すぎると、第三ホスフィンおよびジアゾニウム塩の種類等によっては、これらに分解が生じる場合がある。
また、置換反応における反応時間も、第三ホスフィンおよびジアゾニウム塩の種類等によって適宜設定され、特に限定されないが、２０〜１２０分程度であるのが好ましく、４０〜８０分程度であるのがより好ましい。反応時間が短すぎると、置換反応が十分に進行しない場合があり、一方、反応時間を、前記上限値を超えて長くしても、それ以上の収率の増大が期待できない。
【００３２】
工程［２］、工程［３］
次に、アルコキシ基を一般的な脱保護方法により、ヒドロキシル基に変換［２］した後、フェノール化合物を加え、水酸化ナトリウム等の塩基による脱ＨＸの反応［３］により、ホスホニウム分子化合物を得る。
なお、本発明の硬化促進剤の製造方法、すなわち、第三ホスフィンとジアゾニウム塩が有するジアゾニウム基との置換反応による、前記一般式（１）〜一般式（４）で表される硬化促進剤の製造方法では、ジアゾ化の条件やジアゾ化試薬の種類、保護基の使用の有無、保護基の種類や脱保護方法等は、適宜選択され得るものであり、何ら限定されるものではない。
【００３３】
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、フェノール性水酸基を有する化合物を溶融させると、フェノール性水酸基の効果により、硬化促進剤が良好に硬化剤組成物中に分散すると考えられ、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、樹脂組成物にした際の分散性に優れる。
本発明のエポキシ樹脂用硬化剤組成物への、前記硬化促進剤（Ｂ）の含有量（配合量）は、前記一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）１００重量部に対し、２〜５０重量部を添加することが好ましい。硬化促進剤の含有量が前記範囲を上回る場合、本発明のエポキシ樹脂用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。
【００３４】
本発明のエポキシ樹脂用硬化剤組成物の製法としては、前記各成分を、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。これにより、硬化促進剤成分を、十分に、硬化剤組成物中に均一分散させることができ、硬化性および保存安定性が好適に発揮される。フェノール性水酸基を２個以上有する化合物の、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、表面温度から測定されるコフラーベンチ法などの方法により、測定することができる。また、フェノール性水酸基を２個以上有する化合物として、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、前述の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。
【００３５】
本発明のエポキシ樹脂用硬化剤組成物の製法において、具体的に各成分を溶融混合する条件としては、フェノール性水酸基を２個以上有する化合物の軟化点より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無い。例えば、フェノール性水酸基を有する化合物を、初めに加熱溶融し、その後に、硬化促進剤成分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。
【００３６】
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、前記本発明のエポキシ樹脂用硬化剤組成物と、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成分（Ａ）とは別の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を用いることにより得られる。
【００３７】
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、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。
【００３８】
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。
【００３９】
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配合比は、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。
【００４０】
また、本発明のエポキシ樹脂組成物中には、前記成分の他に、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（混合）するようにしてもよい。
【００４１】
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。
【００４２】
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が良好であり、特に樹脂組成物の保存性に優れ、硬化性、流動性は良好である。
【００４３】
以上、本発明のエポキシ樹脂用硬化促進剤、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。
【００４４】
【実施例】
次に、本発明の具体的実施例について説明する。
【００４５】
まず、硬化促進剤として使用する化合物Ｂ１〜Ｂ７を用意した。
［硬化促進剤の合成］
各化合物Ｂ１〜Ｂ７は、それぞれ、以下のようにして合成した。
【００４６】
（化合物Ｂ１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、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）と、ピリジン塩酸塩８８．７ｇ（０．７６９ｍｏｌ）と、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、ビーカー（容量：５００ｍＬ）に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（０．０５０ｍｍｏｌ）とビスフェノールＳ（２，２−ビス（４−ヒドロキシフェニル）スルホン）１２．５ｇ（０．０５０ｍｍｏｌ）と、メタノール１８０ｍＬとを供給し、攪拌した。
その後、ビーカー内に水酸化ナトリウム２ｇ（０．０５０ｍｍｏｌ）のメタノール溶液２００ｍＬを滴下し、３０分間攪拌した。
次に、反応物を純水２０００ｍＬに滴下し、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−ビスフェノールＳ塩の褐色固形物１０．２ｇを得た。
この化合物をＢ１とした。化合物Ｂ１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化合物であることが確認された。得られた化合物Ｂ１の収率は、２２％であった。
【００４７】
【化１４】

【００４８】
（化合物Ｂ２の合成）
ビスフェノールＳ（２，２−ビス（４−ヒドロキシフェニル）スルホン）に代わり、２，６−ジヒドロキシナフタレン１６．０ｇ（０．１００ｍｍｏｌ）を用い、水酸化ナトリウムの添加量を４．０ｇ（０．１００ｍｍｏｌ）とした以外は、前記化合物Ｂ１の合成と同じ手順で合成を行い、最終的に褐色の結晶２１．４ｇを得た。
この化合物をＢ２とした。化合物Ｂ２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化合物であることが確認された。得られた化合物Ｂ２の収率は、４２％であった。
【００４９】
【化１５】

【００５０】
（化合物Ｂ３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、ビスフェノールＳ（２，２−ビス（４−ヒドロキシフェニル）スルホン）１２．５ｇ（０．０５０ｍｍｏｌ）を１８．８ｇ（０．０７５ｍｍｏｌ）とし、水酸化ナトリウムの添加量を３．０ｇ（０．０７５ｍｍｏｌ）とした以外は、前記化合物Ｂ１の合成と同じ手順で合成を行い、最終的に褐色の結晶１２．２ｇを得た。
この化合物をＢ３とした。化合物Ｂ３を、^１Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（９）で表される目的のホスホニウム化合物であることが確認された。得られた化合物Ｂ３の収率は、２２％であった。
【００５１】
【化１６】

【００５２】
（化合物Ｂ４の合成）
ｏ−メトキシアニリンに代わり、２−メトキシ−５−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Ｂ２の合成と同じ手順で合成を行い、最終的に淡黄白色の結晶２８．１ｇを得た。
この化合物をＢ４とした。化合物Ｂ４を、^１Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（１０）で表される目的のホスホニウム化合物であることが確認された。得られた化合物Ｂ４の収率は、５１％であった。
【００５３】
【化１７】

【００５４】
（化合物Ｂ５の合成）
ｏ−メトキシアニリンに代わり、２−メトキシ−５−メチルアニリン１３．７ｇ（０．１００ｍｏｌ）を用い、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、またビスフェノールＳ（２，２−ビス（４−ヒドロキシフェニル）スルホン）１２．５ｇ（０．０５０ｍｍｏｌ）を２５．０ｇ（０．１００ｍｍｏｌ）とし、水酸化ナトリウムの添加量を４．０ｇ（０．１００ｍｍｏｌ）とした以外は、前記化合物Ｂ１の合成と同じ手順で合成を行い、最終的に黄色結晶３５．６ｇを得た。
この化合物をＢ５とした。化合物Ｂ５を、^１Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（１１）で表される目的のホスホニウム化合物であることが確認された。得られた化合物Ｂ５の収率は、５１％であった。
【００５５】
【化１８】

【００５６】
（化合物Ｂ６の合成）
トリフェニルホスフィンに代わり、トリス（４−メトキシフェニル）ホスフィン２６．８ｇ（０．０７６ｍｏｌ）を用い、また、ビスフェノールＳ（２，２−ビス（４−ヒドロキシフェニル）スルホン）に代わり、ビスフェノールＡ（２，２−ビス（４−ヒドロキシフェニル）プロパン）２２．８ｇ（０．１００ｍｍｏｌ）を用い、水酸化ナトリウムの添加量を４．０ｇ（０．１００ｍｍｏｌ）にした以外は、前記化合物Ｂ１と同じ手順で合成を行い、最終的に、白色結晶１１．９ｇを得た。
この化合物をＢ６とした。化合物Ｂ６を、^１Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（１２）で表される目的のホスホニウム化合物であることが確認された。得られた化合物Ｂ６の収率は、１８％であった。
【００５７】
【化１９】

【００５８】
（化合物Ｂ７の合成）
攪拌装置付きの１リットルセパラブルフラスコに、本州化学工業（株）製ビスフェノールＦ−Ｄ（ビスフェノールＦ異性体混合物）４０．０ｇ（０．２ｍｏｌ）、メタノール５０ｍｌを仕込み、室温で攪拌溶解し、さらに、攪拌しながら、水酸化ナトリウム４．０ｇ（０．１ｍｏｌ）を、予め、５０ｍｌのメタノールで溶解した溶液を添加した。次いで、予め、テトラホスホニウムブロミド４１．９ｇ（０．１ｍｏｌ）を１５０ｍｌのメタノールに溶解した溶液を加えた。しばらく攪拌を継続し、３００ｍｌのメタノールを追加した後、フラスコ内の溶液を大量の水に攪拌しながら滴下し、白色沈殿を得た。
この化合物をＢ７とした。化合物Ｂ７を、^１Ｈ−ＮＭＲ、マススペクトル、元素分析で分析した結果、下記式（１３）で表される目的のホスホニウム化合物であることが確認された。得られた化合物Ｂ７の収率は、５７％であった。
【００５９】
【化２０】

【００６０】
［硬化促進剤の合成］
本発明の硬化剤１〜６、および比較用の硬化剤７は、以下のようにして合成した。
【００６１】
（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下記式（１４）の化合物（明和化成製、商品名ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｂ１の１０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。
【００６２】
【化２１】

【００６３】
（硬化剤２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前記式（１４）の化合物（明和化成製、商品名ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｂ２の１０重量部を用い、１３０℃のオイルバス中、２０分間加熱溶融混合した他は、硬化剤１を得た方法と同様にして、本発明の硬化剤組成物である硬化剤２を得た。
【００６４】
（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前記式（１４）の化合物（明和化成製、商品名ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部、硬化促進剤成分として、上記で得た化合物Ｂ３の１０重量部を用い、１２５℃のオイルバス中、４０分間加熱溶融混合した他は、硬化剤１を得た方法と同様にして、本発明の硬化剤組成物である硬化剤３を得た。
【００６５】
（硬化剤４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（１５）の化合物（三井化学製、商品名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Ｂ４の１０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４を得た。
【００６６】
【化２２】

【００６７】
（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、前記式（１５）の化合物（三井化学製、商品名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Ｂ５の１０重量部を用い、１１０℃のオイルバス中、４５分間加熱溶融混合した他は、硬化剤４を得た方法と同様にして、本発明の硬化剤組成物である硬化剤５を得た。
【００６８】
（硬化剤６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、前記式（１５）の化合物（三井化学製、商品名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Ｂ６の１０重量部を用い、１３０℃のオイルバス中、３０分間加熱溶融混合した他は、硬化剤４を得た方法と同様にして、本発明の硬化剤組成物である硬化剤６を得た。
【００６９】
（硬化剤７の合成）
特許２７９２３９５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、前記式（１４）の化合物（明和化成製、商品名ＭＥＨ−７８５１ＳＳ。軟化点６８℃、水酸基当量１９９）を１００重量部、硬化促進剤成分として、テトラフェニルホスホニウム・テトラフェニルボレー（以下ＴＰＰ−Ｋと略す）１０．０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、１５０℃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７を得た。
【００７０】
［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１〜６、比較例１〜３）
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（熱硬化性樹脂組成物）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。
【００７１】
［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ＩＶＰＳ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。
【００７２】
【表１】

【００７３】
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は硬化促進剤成分がＴＰＰ−Ｋであり、硬化性、流動性、保存性、耐半田性、耐湿信頼性のすべてにおいて、実施例に比べ劣り、比較例２および比較例３で得られたエポキシ樹脂組成物は、硬化性、流動性、耐半田性、耐湿信頼性において劣り、特に保存性は著しく劣っていた。比較例３においては、硬化性、流動性、耐半田性、耐湿信頼性亜において問題ない性能であるが、有用な保存性を得るには至らなかった。
【００７４】
【発明の効果】
以上説明したように、本発明の硬化剤組成物によれば、硬化促進剤を従来通りに添加した場合に比べ、常温での保存性に優れ、該硬化性樹脂組成物は成形時に高い流動性を得ることができ、また、該硬化性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]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a curing agent composition for an 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 containing such a curing agent composition, having good curability, preservability, and fluidity, and suitably used in the field of electric and electronic materials. More specifically, the present invention relates to a semiconductor device having excellent solder crack resistance and moisture resistance reliability.
[0002]
[Prior art]
As a method for obtaining a semiconductor device by encapsulating a semiconductor element such as an IC or an LSI, transfer molding of an epoxy resin composition is widely used because it is low in cost and suitable for mass production. Further, by improving epoxy resin and phenol resin as a curing agent, the characteristics and reliability of the semiconductor device are improved.
[0003]
However, in recent market trends of miniaturization, weight reduction, and high performance of electronic devices, the integration of semiconductors has been increasing year by year, and the surface mounting of semiconductor devices has been promoted. Along with this, demands for epoxy resin compositions used for encapsulating semiconductor devices have become increasingly severe. For this reason, the conventional epoxy resin composition has a problem that cannot be solved (cannot be solved).
[0004]
In recent years, materials used for encapsulation of semiconductor devices have been required to have rapid curability for the purpose of improving production efficiency and storability for the purpose of improving ease of handling during distribution and storage. It is becoming.
[0005]
For the purpose of accelerating the curing reaction of a resin at the time of curing, a phosphonium molecular compound or the like is generally added to an epoxy resin composition for electric / electronic material fields as a curing accelerator (for example, Patent Document 1). reference.).
[0006]
By the way, such a curing accelerator has a temperature range that exhibits a curing acceleration effect extending to a relatively low temperature. For this reason, for example, even when mixing the epoxy resin composition and other components before curing, the curing reaction of the epoxy resin composition partially proceeds by heat generated in the system or heat applied from the outside. . After the mixing is completed, when the epoxy resin composition is stored at room temperature, the reaction further proceeds.
[0007]
This partial progress of the curing reaction causes an increase in viscosity and a decrease in fluidity when the epoxy resin composition is a liquid, and causes the viscosity to be exhibited when the epoxy resin composition is a solid. Such a change in state does not occur uniformly in a strict sense within the epoxy resin composition. For this reason, the curability of each part of the epoxy resin composition varies.
[0008]
This causes the curing reaction to proceed at a high temperature, and when molding the epoxy resin composition (including the concept of other shaping, hereinafter referred to as “molding”), there is a problem in molding due to a decrease in fluidity. , Resulting in reduced mechanical, electrical or chemical properties of the molded article.
[0009]
Therefore, when using a curing accelerator that causes the storage stability of the epoxy resin composition to decrease in this way, strict quality control when mixing various components, storage and transportation at low temperature, and strict molding conditions Management is essential and handling is very complicated.
[0010]
As a curing accelerator to solve this problem, tetraphenylphosphonium tetraphenylborate and a phenol resin containing two or more phenolic hydroxyl groups in one molecule are heated and mixed at a temperature equal to or higher than the softening point of the phenol resin. A technique has been disclosed that achieves both good storage stability, fluidity, and curability (for example, see Patent Document 2). However, even if a curing agent obtained by heating and mixing tetraphenylphosphonium / tetraphenylborate at a temperature equal to or higher than the softening point of the phenol resin cannot be used in the fast curing, storage and fluidity recently required, it is a definitive technology. It wasn't.
[0011]
[Patent Document 1]
JP 2001-98053 A (page 6-9)
[Patent Document 2]
Japanese Patent No. 2792395 (pages 4-6)
[0012]
[Problems to be solved by the invention]
An object of the present invention is to provide a curing agent composition capable of imparting excellent curability and fluidity, which shows particularly excellent preservability to an epoxy resin composition, an epoxy resin composition having good properties, and a solder crack resistant. An object of the present invention is to provide a semiconductor device having excellent heat resistance and humidity resistance.
[0013]
[Means for Solving the Problems]
Such an object is achieved by the present invention described in the following (1) to (6).
[0014]
(1) Consisting 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 100 parts by weight of the component (A) On the other hand, a curing agent composition for an epoxy resin obtained by heating and mixing 2 to 50 parts by weight of the component (B) at a temperature equal to or higher than the softening point of the component (A).
Embedded image

[Wherein, R ₁ , R ₂ And R ₃ Represents a substituted or unsubstituted monovalent aromatic group or a substituted or unsubstituted monovalent alkyl group, which may be the same or different. Ar represents a divalent aromatic group substituted or unsubstituted by a substituent other than a hydroxyl group. A represents a p-valent organic group containing an aromatic ring or a heterocyclic ring, p represents an integer of 2 to 8, and q represents a value of 0 to 2. ]
[0015]
(2) The curing agent composition for an epoxy resin according to (1), wherein the curing accelerator (B) is represented by the following general formula (2).
Embedded image

[Wherein, R ₄ , R ₅ And R ₆ Represents one selected from a hydrogen atom, a methyl group, a methoxy group, and a hydroxyl group, and may be the same or different. A represents a p-valent organic group containing an aromatic ring or a heterocyclic ring, p represents an integer of 2 to 8, and q represents a value of 0 to 2. ]
[0016]
(3) The curing agent composition for an epoxy resin according to (1), wherein the curing accelerator (B) is represented by the following general formula (3) or (4).
Embedded image

Embedded image

[Wherein, R ₇ , R ₈ And R ₉ Represents one selected from a hydrogen atom, a methyl group, a methoxy group, and a hydroxyl group, and may be the same or different. R ₁₀ , R ₁₁ , R ₁₂ And R _Thirteen Represents a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 6 carbon atoms. X represents a single bond, a divalent substituent selected from an ether group, a sulfone group, a sulfide group, and a carbonyl group, or a divalent organic group having 1 to 13 carbon atoms. q represents the value of 0-2. ]
[0017]
(4) 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 (5) and a phenol resin represented by the following general formula (6) The curing agent composition for an epoxy resin according to any one of the above items (1) to (3), comprising:
Embedded image

[Wherein, R ₁₄ ~ R ₁₇ 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. Here, a is an integer of 1 or more. ]
Embedded image

[Wherein, R ₁₈ ~ R ₂₅ 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. Here, b is an integer of 1 or more. ]
[0018]
(5) A compound having two or more epoxy groups in one molecule, the curing agent composition for an epoxy resin according to any one of the above items (1) to (4), and further, if necessary, further in one molecule. And a compound having two or more phenolic hydroxyl groups.
[0019]
(6) A semiconductor device, wherein an electronic component is sealed with a cured product of the epoxy resin composition described in (5).
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The present inventor has conducted intensive studies to solve the above problems, and as a result, it has been found that a curing accelerator composed of a phosphonium compound having a specific structure includes a compound having two or more phenolic hydroxyl groups in one molecule and a specific compound. By melt mixing at a ratio and at a temperature equal to or higher than the softening point of the compound having a phenolic hydroxyl group, it has been found that more excellent storage stability, fluidity, and curability are developed, and the present invention is completed. Reached.
[0021]
Hereinafter, preferred embodiments of a curing agent composition for an epoxy resin, an epoxy resin composition, and a semiconductor device of the present invention will be described.
[0022]
The curing agent composition for an epoxy resin of the present embodiment contains a compound (A) having two or more phenolic hydroxyl groups in one molecule and a curing accelerator (B) represented by the general formula (1). . Such a curing agent composition exhibits good curability, storage stability, and fluidity when used in an epoxy resin composition.
[0023]
Hereinafter, each component will be sequentially described.
The compound (A) having two or more phenolic hydroxyl groups in one molecule used in the present invention is not particularly limited as long as it is a compound having two or more phenolic hydroxyl groups in one molecule. Compounds can be used.
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 one containing, as a main component, one or both of a phenol aralkyl resin represented by the general formula (5) and a biphenyl aralkyl resin represented by the general formula (6). Thereby, when used in an epoxy resin composition, the fluidity during molding is improved, and in particular, when used in a semiconductor device, the solder crack resistance and moisture resistance reliability of the obtained semiconductor device are further improved. .
[0024]
Substituent R in general formulas (5) and (6) ₁₄ ~ R ₁₇ And R ₁₈ ~ R ₂₅ Specific examples of each include, for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a chlorine atom, a bromine atom and the like. Among these, in particular, a hydrogen atom or a methyl group Is preferred. Since such a phenol resin has a low melt viscosity itself, even when it is contained in the epoxy resin composition, the melt viscosity of the epoxy resin composition can be kept low, and as a result, for example, when a semiconductor device is manufactured. In addition, the handling becomes easy. Further, the water absorption (hygroscopicity) of the cured product of the epoxy resin composition (semiconductor device obtained) is reduced, whereby the moisture resistance reliability is further improved, and the solder crack resistance is further improved.
Further, a in the general formula (5) and b in the general formula (6) are not particularly limited as long as each is an integer of 1 or more, and are preferably about 1 to 10, More preferably, it is about 1 to 5. When each of a and b is within the above range, favorable fluidity can be obtained when added to the epoxy resin composition.
[0025]
The curing accelerator (B) used in the present invention has an action (function) capable of accelerating the curing reaction of the epoxy resin composition, and is represented by the general formula (1). It is preferably represented by 2), and more preferably represented by the general formula (3) or the general formula (4).
Here, in the general formula (1), a substituent R bonded to a phosphorus atom ¹ , R ² And R ³ Specific examples include, for example, benzyl, methyl, ethyl, n-butyl, n-octyl, cyclohexyl, naphthyl, p-tert-butylphenyl, 2,6-dimethoxyphenyl, phenyl And various isomers of a methylphenyl group, various isomers of a methoxyphenyl group, various isomers of a hydroxyphenyl group, and the like. Of these, naphthyl group, p-tert-butylphenyl group, 2,6- It is preferably a substituted or unsubstituted monovalent aromatic group such as a dimethoxyphenyl group, a phenyl group, various isomers of a methylphenyl group, various isomers of a methoxyphenyl group, and various isomers of a hydroxyphenyl group, particularly Various isomers of phenyl group, methylphenyl group, various isomers of methoxyphenyl group, various isomers of hydroxyphenyl group Preferably a sex and the like.
In the general formula (1), Ar represents a divalent aromatic group substituted or unsubstituted by a substituent other than a hydroxyl group.
Specific examples of this Ar 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 or an alkoxy group having 1 to 12 carbon atoms. Aromatic groups.
[0026]
In the general formulas (1) to (4), the other anion component forming the phosphonium molecule compound is composed of a phenol compound. As the phenol compound, bisphenol A (2,2-bis (4- (Hydroxyphenyl) propane), bisphenol F (4,4-methylenebisphenol, 2,4-methylenebisphenol, 2,2-methylbisphenol), bisphenol S (2,2-bis (4-hydroxyphenyl) sulfone), bisphenol E (4,4-ethylidene bisphenol), bisphenol fluorene (4,4- (9H-fluoren-9-ylidene) bisphenol) 4,4-methylidenebis (2,6-dimethylphenol), bis (4-hydroxyphenyl) methanone, etc. Bisphenols, 4 Biphenols such as 4-biphenol, 2,2-biphenol, 3,3,5,5-tetramethylbiphenol, hydroquinone, resorcinol, catechol, 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 2,3- Examples thereof include dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,1-bi-2-naphthol, and 1,4-dihydroxyanthraquinone. In terms of physical properties of a cured product, a divalent phenol compound in which p is 2 is used. The presence q is preferably 0.5 to 2, and bisphenol A, bisphenol F (4,4-methylenebisphenol, 2,4-methylenebisphenol, 2,2-methylebisphenol, and bisphenol FD manufactured by Honshu Chemical Co., Ltd.) Mixtures of these isomers), bisphenol S, 4 4-biphenol, 2,6-dihydroxynaphthalene is more preferable.
In general, in the general formula (1), the substituent R ¹ , R ² And R ³ And the combination of Ar includes a substituent R ¹ , R ² And R ³ Are preferably phenyl groups, and Ar is preferably a phenylene group. This is particularly excellent in thermal stability and curing promoting ability, and its production cost is low.
[0027]
The curing accelerator component used in the epoxy resin curing agent composition of the present invention can be synthesized by a known method. Here, an example of a method for producing a phosphonium molecular compound as a curing accelerator of the present invention will be described with reference to the following Chemical Formula 13.
[0028]
Embedded image

[In the formula, R represents a hydrogen atom or a residue selected as appropriate. ]
[0029]
Step [1]
First, for example, an alkoxy-substituted aromatic amine is reacted with a diazotizing reagent such as sodium nitrite under acidic conditions to diazonium chloride. Examples of the alkoxy-substituted aromatic amine to be used include o-methoxyaniline, m-methoxyaniline, p-methoxyaniline, 2-methoxy-5-methylanili and the like.
Next, the diazonium salt is brought into contact with a tertiary phosphine. This gives N ₂ And an alkoxy-substituted aromatic group is introduced into the phosphorus atom of the tertiary phosphine to form a quaternary phosphonium salt. That is, in this step [1], the substitution of the tertiary phosphine with the diazonium group of the diazonium salt occurs. The tertiary phosphines used include triphenylphosphine, tri-p-tolylphosphine, tri (4-methoxyphenyl) phosphine and the like.
[0030]
This substitution reaction is preferably performed in the presence of an alkali. This allows the substitution reaction to proceed more efficiently. The alkali used is not particularly limited. For example, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, sodium hydride, lithium hydride, calcium hydride, lithium aluminum hydride Inorganic bases, such as triethylamine, tripropylamine, tributylamine, pyridine, piperidine, diaminoethane, diaminopropane, diaminobutane, diaminopentane, diaminohexane, diaminooctane, and organic bases such as triethanolamine. One or more of these can be used in combination.
[0031]
The reaction temperature in the substitution reaction is not particularly limited, but is preferably about −10 to 10 ° C., and more preferably about 0 to 5 ° C. If the reaction temperature is too low, the substitution reaction may not proceed sufficiently. On the other hand, if the reaction temperature is too high, depending on the type of the tertiary phosphine and the diazonium salt, decomposition may occur.
The reaction time in the substitution reaction is also appropriately set depending on the type of the tertiary phosphine and the diazonium salt, and is not particularly limited, but is preferably about 20 to 120 minutes, and more preferably about 40 to 80 minutes. . If the reaction time is too short, the substitution reaction may not proceed sufficiently. On the other hand, if the reaction time is longer than the upper limit, further increase in yield cannot be expected.
[0032]
Step [2], Step [3]
Next, after converting the alkoxy group into a hydroxyl group by a general deprotection method [2], a phenol compound is added, and a phosphonium molecule compound is obtained by a reaction [3] of de-HX with a base such as sodium hydroxide. .
In addition, the method for producing the curing accelerator of the present invention, that is, the curing accelerator represented by the general formula (1) to the general formula (4) by the substitution reaction between the tertiary phosphine and the diazonium group of the diazonium salt is used. In the production method, the conditions for diazotization, the type of diazotizing reagent, the use of a protective group, the type of protective group, the deprotection method, and the like can be appropriately selected, and are not limited at all.
[0033]
The curing accelerator used for the epoxy resin curing agent composition of the present invention is considered to disperse the curing accelerator in the curing agent composition by the effect of the phenolic hydroxyl group when the compound having a phenolic hydroxyl group is melted. As compared with the case where the curing accelerator is directly added to the epoxy resin composition, the resin composition is more excellent in dispersibility.
The content (blending amount) of the curing accelerator (B) in the epoxy resin curing agent composition of the present invention is based on 100 parts by weight of the compound (A) having two or more phenolic hydroxyl groups in one molecule. On the other hand, it is preferable to add 2 to 50 parts by weight. When the content of the curing accelerator exceeds the above range, when the epoxy resin curing agent composition of the present invention is added to the epoxy resin composition, the dispersibility is not sufficiently exhibited, and the fluidity and storage stability are reduced. May be impaired. Further, when the amount is below the above range, the addition amount required to obtain sufficient curability becomes extremely large, and when an epoxy resin composition is used, the balance between the epoxy resin component and the curing agent component becomes poor, and the cured product The characteristics may be degraded.
[0034]
The method for producing the curing agent composition for an epoxy resin of the present invention is carried out by heating and mixing the above components at a temperature not lower than the softening point of the compound (A) having two or more phenolic hydroxyl groups. Thereby, the curing accelerator component can be sufficiently dispersed uniformly in the curing agent composition, and the curability and the storage stability are suitably exhibited. As a method for measuring the softening point of a compound having two or more phenolic hydroxyl groups, specifically, a powder of the compound is sprayed on a metal plate having a temperature gradient, and after one minute, the powder of the compound is dispersed. Can be measured by a method such as the Kofler bench method, which is measured from the surface temperature, at the point where it melts and adheres to the metal plate when brushed. When a compound obtained by mixing a plurality of compounds is used as the compound having two or more phenolic hydroxyl groups, these compounds are previously melted and mixed uniformly, and then the softening point is determined by the Kofler bench method described above. Can be measured.
[0035]
In the method for producing a curing agent composition for an epoxy resin of the present invention, specific conditions for melting and mixing each component are as follows: at a temperature higher by 10 to 150 ° C. than the softening point of a compound having two or more phenolic hydroxyl groups, by 20 to 20 ° C. Mix for 200 minutes. Conventionally known devices and techniques can be used for such melt mixing. Specifically, the mixture of the components can be melt-mixed using an apparatus such as a heating kneader or a heating roll to obtain a curing agent composition.
In addition, at the time of the melt mixing, there is no problem in appropriately adjusting the order of adding each component according to the compound to be added. For example, a compound having a phenolic hydroxyl group can be heated and melted first, and then a curing accelerator component can be added. When a compound having a plurality of phenolic hydroxyl groups is used, one of the components may be heated and melted in advance, and then the other component may be added.
[0036]
The epoxy resin composition of the present invention comprises a compound having two or more epoxy groups in one molecule, the epoxy resin curing agent composition of the present invention, and optionally, the epoxy resin curing agent composition. And a compound having two or more phenolic hydroxyl groups in one molecule different from the component (A) used in the above.
[0037]
As the compound having two or more epoxy groups in one molecule used in the present invention, conventionally known compounds can be used. Specifically, bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol type epoxy resin, stilbene type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, naphthalene type epoxy resin Resins, dicyclopentadiene-type epoxy resins, dihydroxybenzene-type epoxy resins, etc., epoxy resins, epoxy compounds, or other alicycles produced by reacting epichlorohydrin with hydroxyl groups such as phenols, phenolic resins, and naphthols As in the case of the formula epoxy resin, an epoxy resin obtained by oxidizing an olefin with a peracid to epoxidize it, a glycidyl ester type epoxy resin, a glycidylamine type epoxy resin and the like can be mentioned. It can be used singly or in combination of two or more.
[0038]
In addition, if necessary, the compound having two or more phenolic hydroxyl groups in one molecule to be further added may be the same compound as that used for obtaining the epoxy resin curing agent composition of the present invention. , And may also be different. The compound having the additional phenolic hydroxyl group is used for adjusting the ratio of the epoxy group to the phenolic hydroxyl group in the epoxy resin composition.
[0039]
In the epoxy resin composition of the present invention, the compounding ratio of the epoxy group and the phenolic hydroxyl group is determined based on 1 mole of the epoxy group, the total amount of the curing agent composition, and the total amount of the phenolic hydroxyl groups of the compound having a phenolic hydroxyl group additionally used. Is preferably about 0.5 to 2 mol, and more preferably about 0.7 to 1.5 mol. Thereby, various characteristics are further improved while maintaining the balance of various characteristics of the epoxy resin composition in a preferable state.
[0040]
In the epoxy resin composition of the present invention, in addition to the above components, if necessary, for example, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a coloring agent such as carbon black, Various types of flame retardants such as epoxy resin, antimony oxide and phosphorus compounds, low stress components such as silicone oil and silicone rubber, natural wax, synthetic wax, higher fatty acids or metal salts thereof, release agents such as paraffin, antioxidants, etc. You may make it mix | blend (mix) an additive.
[0041]
The epoxy resin composition of the present invention, the components, and, if necessary, other additives and the like, using a mixer, mixed at room temperature, heated and kneaded using a heating roll, a heating kneader, and cooled, Obtained by grinding.
[0042]
The obtained epoxy resin composition is used as a mold resin and cured by a molding method such as transfer molding, compression molding, or injection molding to seal electronic components such as semiconductor elements. Thereby, the semiconductor device of the present invention is obtained.
The semiconductor device of the present invention obtained as described above has good solder crack resistance and moisture resistance reliability, and particularly has excellent storage stability, curability and fluidity of the resin composition.
[0043]
The preferred embodiments of the epoxy resin 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.
[0044]
【Example】
Next, specific examples of the present invention will be described.
[0045]
First, compounds B1 to B7 used as curing accelerators were prepared.
[Synthesis of curing accelerator]
Each of the compounds B1 to B7 was synthesized as follows.
[0046]
(Synthesis of Compound B1)
In a separable flask (capacity: 500 mL) equipped with a condenser and a stirring device, 12.3 g (0.100 mol) of o-methoxyaniline and an aqueous hydrochloric acid solution in which 25 mL of concentrated hydrochloric acid (37%) was previously dissolved in 200 mL of pure water And dissolved under stirring.
Thereafter, the separable flask was ice-cooled, and an aqueous solution of 7.2 g (0.104 mol) of sodium nitrite (20 mL) was slowly dropped into the solution while maintaining 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, followed by stirring 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 the mixture was vigorously stirred 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 formed precipitate is filtered and dried, and 2-methoxyphenyltriphenylphosphonium is added. 29.7 g of reddish brown crystals of iodide were obtained.
Next, 29.7 g (0.060 mol) of the 2-methoxyphenyltriphenylphosphonium iodide and 88.7 g (0.769 mol) of pyridine hydrochloride were placed in a separable flask (capacity: 500 mL) equipped with a condenser and a stirrer. ) And 12.0 g (0.118 mol) of acetic anhydride, and the mixture was 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 2-hydroxyphenyltriphenylphosphonium iodide as a brown solid.
Next, 24.1 g (0.050 mmol) of 2-hydroxyphenyltriphenylphosphonium iodide and 12.5 g of bisphenol S (2,2-bis (4-hydroxyphenyl) sulfone) were added to a beaker (capacity: 500 mL). 050 mmol) and 180 mL of methanol were supplied and stirred.
Thereafter, 200 mL of a methanol solution of 2 g (0.050 mmol) of sodium hydroxide was dropped into the beaker, and the mixture was stirred for 30 minutes.
Next, the reaction product was dropped into 2000 mL of pure water, and the precipitated solid was filtered and dried to obtain 10.2 g of a brown solid of 2-hydroxyphenyltriphenylphosphonium-bisphenol S salt.
This compound was designated as B1. Compound B1 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (7). The yield of the obtained compound B1 was 22%.
[0047]
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[0048]
(Synthesis of Compound B2)
Instead of bisphenol S (2,2-bis (4-hydroxyphenyl) sulfone), 16.0 g (0.100 mmol) of 2,6-dihydroxynaphthalene was used, and the amount of sodium hydroxide added was 4.0 g (0.100 mmol). ) Except that the compound was synthesized in the same manner as in the synthesis of the compound B1, and finally 21.4 g of brown crystals were obtained.
This compound was designated as B2. Compound B2 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (8). The yield of the obtained compound B2 was 42%.
[0049]
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[0050]
(Synthesis of Compound B3)
Instead of o-methoxyaniline, 12.3 g (0.100 mol) of p-methoxyaniline was used, and 12.5 g (0.050 mmol) of bisphenol S (2,2-bis (4-hydroxyphenyl) sulfone) was added to 18 2.8 g (0.075 mmol) and the amount of sodium hydroxide added was 3.0 g (0.075 mmol). 2 g were obtained.
This compound was designated as B3. Compound B3 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (9). The yield of the obtained compound B3 was 22%.
[0051]
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[0052]
(Synthesis of Compound B4)
In place of o-methoxyaniline, 13.7 g (0.100 mol) of 2-methoxy-5-methylaniline was used. In place of triphenylphosphine, 23.1 g (0.076 mol) of tri-p-tolylphosphine was used. Except for the above, the synthesis was carried out in the same manner as in the synthesis of the compound B2, to finally obtain 28.1 g of pale yellowish white crystals.
This compound was designated as B4. Compound B4 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (10). The yield of the obtained compound B4 was 51%.
[0053]
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[0054]
(Synthesis of Compound B5)
Instead of o-methoxyaniline, 13.7 g (0.100 mol) of 2-methoxy-5-methylaniline was used, and instead of triphenylphosphine, 23.1 g (0.076 mol) of tri-p-tolylphosphine was used. 12.5 g (0.050 mmol) of bisphenol S (2,2-bis (4-hydroxyphenyl) sulfone) was 25.0 g (0.100 mmol), and the amount of sodium hydroxide added was 4.0 g (0.100 mmol). The synthesis was carried out in the same manner as in the synthesis of the compound B1, except that the compound B1 was obtained, and finally 35.6 g of yellow crystals were obtained.
This compound was designated as B5. Compound B5 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (11). The yield of the obtained compound B5 was 51%.
[0055]
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[0056]
(Synthesis of Compound B6)
In place of triphenylphosphine, 26.8 g (0.076 mol) of tris (4-methoxyphenyl) phosphine was used, and in place of bisphenol S (2,2-bis (4-hydroxyphenyl) sulfone), bisphenol A (2 , 2-bis (4-hydroxyphenyl) propane), using the same procedure as for the compound B1, except that the amount of sodium hydroxide added was 4.0 g (0.100 mmol). Synthesis was performed, and finally 11.9 g of white crystals were obtained.
This compound was designated as B6. Compound B6 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (12). The yield of the obtained compound B6 was 18%.
[0057]
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[0058]
(Synthesis of Compound B7)
A 1-liter separable flask equipped with a stirrer was charged with 40.0 g (0.2 mol) of bisphenol FD (mixture of bisphenol F isomers) manufactured by Honshu Chemical Industry Co., Ltd. and 50 ml of methanol, and dissolved by stirring at room temperature. While stirring, a solution prepared by previously dissolving 4.0 g (0.1 mol) of sodium hydroxide in 50 ml of methanol was added. Next, a solution in which 41.9 g (0.1 mol) of tetraphosphonium bromide was dissolved in 150 ml of methanol was added in advance. Stirring was continued for a while, and after adding 300 ml of methanol, the solution in the flask was dropped into a large amount of water while stirring to obtain a white precipitate.
This compound was designated as B7. Compound B7 is ¹ As a result of analysis by H-NMR, mass spectrum, and elemental analysis, it was confirmed that the target phosphonium compound was represented by the following formula (13). The yield of the obtained compound B7 was 57%.
[0059]
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[0060]
[Synthesis of curing accelerator]
The curing agents 1 to 6 of the present invention and the curing agent 7 for comparison were synthesized as follows.
[0061]
(Synthesis of curing agent 1)
As a compound having two or more phenolic hydroxyl groups in one molecule, a compound of the following formula (14) (trade name: MEH-7851SS, manufactured by Meiwa Kasei Co., Ltd .; softening point: 68 ° C., hydroxyl equivalent: 199 parts): 100 parts by weight, a curing accelerator As a component, 10 parts by weight of the compound B1 obtained above was put into a 5 L separable flask equipped with a thermometer and a cooling tube, and was heated and melt-mixed in an oil bath at 120 ° C. for 30 minutes, and the obtained melt mixture was cooled. Thereafter, the resultant was pulverized to obtain a curing agent 1 which is a curing agent composition of the present invention.
[0062]
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[0063]
(Synthesis of curing agent 2)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of the compound of the above formula (14) (product name: MEH-7851SS, manufactured by Meiwa Kasei Co., Ltd .; softening point 68 ° C, hydroxyl equivalent 199), and a curing accelerator As a component, the curing agent composition of the present invention was prepared in the same manner as in the method for obtaining the curing agent 1, except that 10 parts by weight of the compound B2 obtained above was used and heated and mixed in an oil bath at 130 ° C. for 20 minutes. A curing agent 2 was obtained.
[0064]
(Synthesis of 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 above formula (14) (product name: MEH-7851SS, manufactured by Meiwa Kasei Co., Ltd .; softening point 68 ° C, hydroxyl equivalent 199), and a curing accelerator As a component, the curing agent composition of the present invention was prepared in the same manner as in the method of obtaining the curing agent 1, except that 10 parts by weight of the compound B3 obtained above was heated and melt-mixed in an oil bath at 125 ° C. for 40 minutes. A curing agent 3 was obtained.
[0065]
(Synthesis of curing agent 4)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of a compound represented by the following formula (15) (manufactured by Mitsui Chemicals, trade name: XLC-LL; softening point: 77 ° C., hydroxyl equivalent: 172); As an agent component, 10 parts by weight of the compound B4 obtained above was put into a 5 L separable flask equipped with a thermometer and a condenser, and heated and melt-mixed in an oil bath at 120 ° C. for 30 minutes. After cooling, the mixture was pulverized to obtain a curing agent 4 which is a curing agent composition of the present invention.
[0066]
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[0067]
(Synthesis of curing agent 5)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of the compound of the above formula (15) (manufactured by Mitsui Chemicals, trade name: XLC-LL; softening point: 77 ° C., hydroxyl equivalent: 172), 100 parts by weight, curing acceleration The curing agent of the present invention was prepared in the same manner as the method for obtaining the curing agent 4, except that 10 parts by weight of the compound B5 obtained above was used as an agent component, and the mixture was heated and mixed in an oil bath at 110 ° C. for 45 minutes. A curing agent 5 as a composition was obtained.
[0068]
(Synthesis of curing agent 6)
As a compound having two or more phenolic hydroxyl groups in one molecule, 100 parts by weight of the compound of the above formula (15) (manufactured by Mitsui Chemicals, trade name: XLC-LL; softening point: 77 ° C., hydroxyl equivalent: 172), 100 parts by weight, curing acceleration The curing agent of the present invention was prepared in the same manner as the method for obtaining the curing agent 4, except that 10 parts by weight of the compound B6 obtained above was used as an agent component, and the mixture was heated and mixed in an oil bath at 130 ° C. for 30 minutes. A curing agent 6 as a composition was obtained.
[0069]
(Synthesis of curing agent 7)
According to the method described in Japanese Patent No. 2792395, as a compound having two or more phenolic hydroxyl groups in one molecule, a compound of the above formula (14) (trade name MEH-7851SS, manufactured by Meiwa Kasei Co., Ltd .; softening point 68 ° C, hydroxyl equivalent) 199) as a curing accelerator component, and 10.0 parts by weight of tetraphenylphosphonium / tetraphenyl volley (hereinafter abbreviated as TPP-K) in a 5 L separable flask equipped with a thermometer and a cooling tube. After heating in an oil bath at 30 ° C. for 30 minutes, mixing was performed for 60 minutes, and the obtained molten mixture was cooled and pulverized to obtain a curing agent 7 as a comparative curing agent.
[0070]
[Preparation of epoxy resin composition and manufacture of semiconductor device]
(Examples 1 to 6, Comparative Examples 1 to 3)
The curing agents 1 to 9, epoxy resin, and if necessary, other curing agents and other components are mixed at a ratio shown in Table 1 at room temperature, and further heated at 95 ° C. for 8 minutes using a hot roll. After kneading, the mixture was pulverized by cooling to obtain an epoxy resin composition (thermosetting resin composition).
Using this epoxy resin composition as a mold resin, eight 100-pin TQFP (Thin Quad Flat Package) packages (semiconductor devices) and fifteen 16-pin DIP (Dual Inline Package) packages (semiconductor devices) were used. 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, a curing time of 2 minutes, and post-curing at 175 ° C. for 8 hours.
The package size of this 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, a curing time of 2 minutes, and post-curing at 175 ° C. for 8 hours.
The package size of the 16-pin DIP was 6.4 × 19.8 mm, the thickness was 3.5 mm, the size of the silicon chip (semiconductor element) was 3.5 × 3.5 mm, and the lead frame was made of 42 alloy. .
[0071]
[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 mold for spiral flow measurement according to EMMI-I-66, the 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 a larger value indicates better fluidity.
(2): curing torque
Using a curast meter (manufactured by Orientec Co., Ltd., JSR curast meter IVPS type), the torque was measured at 175 ° C. for 45 seconds.
The larger the numerical value of the curing torque, the better the curability.
(3): Flow remaining rate
After the obtained epoxy resin composition was stored in the air at 40 ° C. for one week, the spiral flow was measured in the same manner as in (1), and the percentage (%) with respect to the spiral flow immediately after preparation was determined.
The larger the numerical value of the flow residual ratio, the better the storage stability.
(4): Solder crack resistance
The 100-pin TQFP was left in an environment of 85 ° C. and 85% relative humidity for 168 hours, and then immersed in a 260 ° C. solder bath for 10 seconds.
Thereafter, the presence or absence of external cracks was observed under a microscope, and the rate of cracks was expressed as a percentage (%) as follows: crack occurrence rate = (number of packages in which cracks occurred) / (total number of packages) × 100.
Further, the ratio of the peeling area between the silicon chip and the cured product of the epoxy resin composition was measured using an ultrasonic flaw detector, and the peeling rate = (peeling area) / (area of silicon chip) × 100, and eight pieces were determined. The average value of the packages was calculated and expressed as a percentage (%).
The smaller the numerical values of the crack occurrence rate and the peeling rate, 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 100% relative humidity to check for disconnection failure. The time required until eight or more of the 15 packages failed was defined as a failure time.
Note that the measurement time is 500 hours at the maximum, and when the number of defective packages is less than 8 at that time, the defective time is indicated as more than 500 hours (> 500).
The larger the value of the defective time, the better the moisture resistance reliability.
Table 1 shows the results of the characteristic evaluations (1) to (5).
[0072]
[Table 1]

[0073]
As shown in Table 1, each of the epoxy resin compositions (the epoxy resin composition of the present invention) obtained in each of the examples has extremely good curability, storage stability, and fluidity. Each of the packages (semiconductor device of the present invention) sealed with a product had good solder crack resistance and moisture resistance reliability.
On the other hand, in Comparative Example 1, the curing accelerator component was TPP-K, and all of the curability, fluidity, preservability, solder resistance, and humidity resistance were inferior to the Examples, and Comparative Example 2 and Comparative Example 2 The epoxy resin composition obtained in Example 3 was inferior in curability, fluidity, solder resistance, and moisture resistance reliability, and in particular, extremely poor in storage stability. In Comparative Example 3, the curability, fluidity, soldering resistance, and moisture resistance reliability were satisfactory, but useful preservability was not obtained.
[0074]
【The invention's effect】
As described above, according to the curing agent composition of the present invention, compared with the case where a curing accelerator is conventionally added, the storage stability at room temperature is excellent, and the curable resin composition has high fluidity during molding. The package made using the curable resin composition can preferably prevent the cured product from being defective even when exposed to a high temperature. , Good reliability can be exhibited.

Claims (6)

It comprises 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). A curing agent composition for an epoxy resin obtained by heating and mixing 2 to 50 parts by weight of the component (B) at a temperature equal to or higher than the softening point of the component (A).

[In the formula, R ₁ , R ₂ and R ₃ each represent a substituted or unsubstituted monovalent aromatic group or a substituted or unsubstituted monovalent alkyl group. It may be. Ar represents a divalent aromatic group substituted or unsubstituted by a substituent other than a hydroxyl group. A represents a p-valent organic group containing an aromatic ring or a heterocyclic ring, p represents an integer of 2 to 8, and q represents a value of 0 to 2. ] The curing agent composition for an epoxy resin according to claim 1, wherein the curing accelerator (B) is represented by the following general formula (2).

[Wherein, R ₄ , R ₅ and R ₆ 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. A represents a p-valent organic group containing an aromatic ring or a heterocyclic ring, p represents an integer of 2 to 8, and q represents a value of 0 to 2. ] The curing agent composition for an epoxy resin according to claim 1, wherein the curing accelerator (B) is represented by the following general formula (3) or (4).

[Wherein, R ₇ , R ₈ and R ₉ 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. R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ represent a hydrogen atom, a halogen atom or a monovalent organic group having 1 to 6 carbon atoms. X represents a single bond, a divalent substituent selected from an ether group, a sulfone group, a sulfide group, and a carbonyl group, or a divalent organic group having 1 to 13 carbon atoms. q represents the value of 0-2. ] The compound (A) having two or more phenolic hydroxyl groups in one molecule contains at least one of a phenol resin represented by the following general formula (5) and a phenol resin represented by the following general formula (6) as a main component. The curing agent composition for an epoxy resin according to any one of claims 1 to 3, wherein

[Wherein, R _{14 to} R ₁₇ 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. Here, a is an integer of 1 or more. ]

[Wherein, R _{18 to} R ₂₅ 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. Here, b is an integer of 1 or more. ] An epoxy resin composition comprising: a compound having two or more epoxy groups in one molecule; and the curing agent composition for an epoxy resin according to claim 1. A semiconductor device comprising an electronic component sealed with a cured product of the epoxy resin composition according to claim 5.