JP3890681B2 - Epoxy resin molding material for electronic component sealing and electronic component - Google Patents

Description

（ここで、Ｒ¹は水素または炭素数１〜６のアルキル基または炭素数１〜２のアルコキシ基、Ｒ²は炭素数１〜６のアルキル基またはフェニル基、Ｒ³はメチル基またはエチル基で、ｎは１〜６の数を示す。）
（２）下記一般式（II）のシラン化合物を含むことを特徴とする上記（１）記載のエポキシ樹脂組成物、
【化６】
（Ｒ¹）₂−Ｓｉ−（ＯＲ²）₂ ………（II）
（ここで、Ｒ¹は炭素数１〜１０のアルキル基またはフェニル基で、Ｒ²はメチル基またはエチル基を示す。）
（３）下記一般式（III）のエポキシ樹脂を含むことを特徴とする上記（１）または（２）記載のエポキシ樹脂組成物、
【化７】

（ここで、Ｒ¹〜Ｒ⁴は水素または炭素数１〜１０の炭化水素を示し、互いに同一でも異なっていてもよい。ｎは０〜３の正の数を示す。）
（４）下記一般式（IV）の硬化剤を含むことを特徴とする上記（１）〜（３）いずれか記載のエポキシ樹脂組成物、
【化８】

（ここで、Ｒは水素または炭素数１〜１０の炭化水素またはハロゲンで、ｎは０〜８の正の数を示す。）
（５）上記（１）〜（４）いずれか記載のエポキシ樹脂組成物を含むことを特徴とする電子部品封止用エポキシ樹脂成形材料、
（６）上記（５）記載の成形材料により素子を封止して得られる電子部品、
である。
【０００９】
【発明の実施の形態】
本発明において用いられる（Ａ）成分のエポキシ樹脂は特に限定はないが、たとえば、電子部品封止用エポキシ樹脂成形材料で一般に使用されているもので、フェノールノボラック型エポキシ樹脂、オルソクレゾールノボラック型エポキシ樹脂、ビスフェノ−ルＡノボラック型エポキシ樹脂をはじめとするフェノール類とアルデヒド類から合成されるノボラック樹脂をエポキシ化したエポキシ樹脂、ビスフェノールＡ、ビスフェノールＦ、ビスフェノールＳ、アルキル置換ビフェノールなどのジグリシジルエーテル、ジアミノジフェニルメタン、イソシアヌル酸などのポリアミンとエピクロルヒドリンの反応により得られるグリシジルアミン型エポキシ樹脂、ジシクロペンタジエンとフェノ−ル類の共縮合樹脂のエポキシ化物、ナフタレン環を有するエポキシ樹脂、ナフトールアラルキル樹脂のエポキシ化物、トリメチロールプロパン型エポキシ樹脂、テルペン変性エポキシ樹脂、オレフィン結合を過酢酸などの過酸で酸化して得られる線状脂肪族エポキシ樹脂、及び脂環族エポキシ樹脂などが挙げられ、耐リフロー性の面からは下記一般式（III）のエポキシ樹脂が好適である。
【化９】

（ここで、Ｒ¹〜Ｒ⁴は水素または炭素数１〜１０の炭化水素を示し、互いに同一でも異なっていてもよい。ｎは０〜３の正の数を示す。）
これを例示すると、４，４’−ビス（２，３−エポキシプロポキシ）ビフェニルや４，４’−ビス（２，３−エポキシプロポキシ）−３，３’，５，５’−テトラメチルビフェニルを主成分とするエポキシ樹脂、エピクロルヒドリンと４，４’−ビス（２，３−エポキシプロポキシ）ビフェノールや４，４’−ビス（２，３−エポキシプロポキシ）−３，３’，５，５’−テトラメチルビフェノールとを反応して得られるエポキシ樹脂等が挙げられる。中でも４，４’−ビス（２，３−エポキシプロポキシ）−３，３’，５，５’−テトラメチルビフェニルを主成分とするエポキシ樹脂が好ましい。
これらのエポキシ樹脂を単独又は２種類以上併用して使用することができる。
【００１０】
本発明において用いられる（Ｂ）成分の硬化剤は特に限定はないが、たとえば、電子部品封止用エポキシ樹脂成形材料で一般に使用されているもので、フェノール、クレゾール、レゾルシン、カテコール、ビスフェノールＡ、ビスフェノールＦ等のフェノール類又はα−ナフトール、β−ナフトール、ジヒドロキシナフタレン等のナフトール類とホルムアルデヒド等のアルデヒド類とを酸性触媒下で縮合又は共縮合させて得られる樹脂、フェノール・アラルキル樹脂、ナフトール・アラルキル樹脂等があり、特に耐リフロー性の面からは下記一般式（IV）で表されるフェノール・アラルキル樹脂が好適である。
【化１０】

（ここで、Ｒは水素または炭素数１〜１０の炭化水素またはハロゲンで、ｎは０〜８の正の数を示す。）
中でも下記の式（Ｖ）で示され、ｎが平均的に０〜８のものが好ましい。
【化１１】

これらの硬化剤は単独又は２種類以上併用して用いることができる。
【００１１】
また、（Ａ）成分のエポキシ樹脂と（Ｂ）成分の硬化剤の当量比、すなわち、エポキシ樹脂中のエポキシ基数／硬化剤中の水酸基数の比は、特に限定はされないが、それぞれの未反応分を少なく抑えるために０．７〜１．３の範囲に設定することが好ましく、特に成形性、耐リフロー性に優れる成形材料を得るためには０．８〜１．２の範囲に設定することが好ましい。
【００１２】
本発明に用いられる（Ｃ）成分のシランカップリング剤は、下記一般式（Ｉ）で表されものである。
【化１２】

（ここで、Ｒ¹は水素または炭素数１〜６のアルキル基または炭素数１〜２のアルコキシ基、Ｒ²は炭素数１〜６のアルキル基またはフェニル基、Ｒ³はメチル基またはエチル基で、ｎは１〜６の数を示す。）
これを例示すると、γ−アニリノプロピルメチルジメトキシシラン、γ−アニリノプロピルメチルジエトキシシラン、γ−アニリノメチルメチルジメトキシシラン、γ−アニリノメチルメチルジエトキシシラン、Ｎ−（ｐ−メトキシフェニル）−γ−アミノプロピルメチルジメトキシシラン、Ｎ−（ｐ−メトキシフェニル）−γ−アミノプロピルメチルジエトキシシラン等が挙げられ、中でもリードフレームとの接着性、耐湿性及びパッケージの成形性という観点からはγ−アニリノプロピルメチルジメトキシシランが好適に用いられる。
【００１３】
（Ｃ）成分のシランカップリング剤の配合量は、（Ｄ）成分の無機充填剤に対して０．２〜５．０重量％であることが好ましく、さらに好ましくは０．５〜２．５重量％である。０．２重量％未満ではフレ−ムとの接着性が低下しやすく、５．０重量％を超える場合にはパッケージの成形性が低下しがちである。
【００１４】
本発明のエポキシ樹脂組成物および電子部品封止用エポキシ樹脂成形材料には、上記（Ｃ）成分のシランカップリング剤以外に従来公知のカップリング剤を併用してもよい。たとえば、ビニルトリクロロシラン、ビニルトリエトキシシラン、ビニルトリス（β−メトキシエトキシ）シラン、γ−メタクリロキシプロピルトリメトキシシラン、β−（３，４−エポキシシクロヘキシル）エチルトリメトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、γ−メルカプトプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシラン、γ−［ビス（β−ヒドロキシエチル）］アミノプロピルトリエトキシシラン、Ｎ−β−（アミノエチル）−γ−アミノプロピルトリメトキシシラン、γ−（β−アミノエチル）アミノプロピルジメトキシメチルシラン、Ｎ−（トリメトキシシリルプロピル）エチレンジアミン、Ｎ−（ジメトキシメチルシリルイソプロピル）エチレンジアミン、メチルトリメトキシシラン、メチルトリエトキシシラン、、Ｎ−β−（Ｎ−ビニルベンジルアミノエチル）−γ−アミノプロピルトリメトキシシラン、γ−クロロプロピルトリメトキシシラン、ヘキサメチルジシラン、γ−アニリノプロピルトリメトキシシラン、ビニルトリメトキシシラン、γ−メルカプトプロピルメチルジメトキシシラン等のシラン系カップリング剤、あるいはイソプロピルトリイソステアロイルチタネート、イソプロピルトリス（ジオクチルパイロホスフェート）チタネート、イソプロピルトリ（Ｎ−アミノエチル−アミノエチル）チタネート、テトラオクチルビス（ジトリデシルホスファイト）チタネート、テトラ（２，２−ジアリルオキシメチル−１−ブチル）ビス（ジトリデシル）ホスファイトチタネート、ビス（ジオクチルパイロホスフェート）オキシアセテートチタネート、ビス（ジオクチルパイロホスフェート）エチレンチタネート、イソプロピルトリオクタノイルチタネート、イソプロピルジメタクリルイソステアロイルチタネート、イソプロピルトリドデシルベンゼンスルホニルチタネート、イソプロピルイソステアロイルジアクリルチタネート、イソプロピルトリ（ジオクチルホスフェート）チタネート、イソプロピルトリクミルフェニルチタネート、テトライソプロピルビス（ジオクチルホスファイト）チタネート等のチタネート系カップリング剤を１種以上併用することができる。
【００１５】
本発明における（Ｄ）成分の無機充填剤としては、特に限定はないが、溶融シリカ、結晶シリカ、アルミナ、ジルコン、珪酸カルシウム、炭酸カルシウム、炭化珪素、窒化アルミ、窒化ホウ素、ベリリア、ジルコニア等の粉体、又はこれらを球形化したビーズ、チタン酸カリウム、炭化珪素、窒化珪素、アルミナ等の単結晶繊維、ガラス繊維等を１種類以上配合して用いることができる。さらに、難燃効果のある無機充填剤としては水酸化アルミニウム、水酸化マグネシウム、硼酸亜鉛などが挙げられ、これらを単独または併用して用いることもできる。上記の無機充填剤の中で、線膨張係数低減の観点からは溶融シリカが、高熱伝導性の観点からはアルミナが好ましい。充填剤形状は、成形時の流動性及び金型摩耗性の点から球形もしくは球状に近い形が好ましく、５０重量％以上が球形であることが特に好ましい。
【００１６】
無機充填剤（Ｄ）の配合量は、吸湿性、線膨張係数の低減及び強度向上の観点から、成形材料全体に対して７０重量％以上が好ましく、８５〜９５重量％であることが特に好ましい。８５重量％未満では耐リフロー性が低下しやすく、９５重量％を超える場合には流動性が不足しがちである。中でも８８〜９２重量％の範囲がさらに好適である。
【００１７】
本発明のエポキシ樹脂組成物および電子部品封止用エポキシ樹脂成形材料には、上記（Ａ）〜（Ｄ）成分以外に下記一般式（II）のシラン化合物を使用することができる。
【化１３】
（Ｒ¹）₂−Ｓｉ−（ＯＲ²）₂ ………（II）
（ここで、Ｒ¹は炭素数１〜１０のアルキル基またはフェニル基で、Ｒ²はメチル基またはエチル基を示す。）
上記一般式（II）のシラン化合物は、酸化膜剥離の抑制や半田耐熱性の向上に効果的である。これを例示すると、ジメチルジメトキシシラン、ジメチルジエトキシシラン、ジフェニルジメトキシシラン、ジフェニルジエトキシシラン、メチルフェニルジメトキシシラン、メチルフェニルジエトキシシラン等が挙げられ、中でも特にジメチルジメトキシシランが好ましい。
【００１８】
一般式（II）のシラン化合物の配合量は、（Ｃ）成分との比（（Ｃ）／（II））が０．５〜１０となるよう設定されることが好ましく、さらに好ましくは１〜５である。０．５未満ではフレ−ムとの接着性が低下しやすく、１０を超える場合には耐湿信頼性が低下しがちである。
【００１９】
本発明のエポキシ樹脂組成物および電子部品封止用エポキシ樹脂成形材料には、硬化促進剤も使用することができる。例えば、１，８−ジアザ−ビシクロ（５，４，０）ウンデセン−７、１，５−ジアザ−ビシクロ（４，３，０）ノネン、５、６−ヂブチルアミノ−１，８−ジアザ−ビシクロ（５，４，０）ウンデセン−７、ベンジルジメチルアミン、トリエタノールアミン、ジメチルアミノエタノール、トリス（ジメチルアミノメチル）フェノール等の３級アミン類及びこれらの誘導体、２−メチルイミダゾール、２−フェニルイミダゾール、２−フェニル−４−メチルイミダゾール等のイミダゾール類及びこれらの誘導体、トリブチルホスフィン、メチルジフェニルホスフィン、トリフェニルホスフィン、ジフェニルホスフィン、フェニルホスフィン等の有機ホスフィン類及びこれらのホスフィン類に無水マレイン酸、ベンゾキノン、ジアゾフェニルメタン等のπ結合をもつ化合物を付加してなる分子内分極を有するリン化合物、テトラフェニルホスホニウムテトラフェニルボレート、トリフェニルホスフィンテトラフェニルボレート、２−エチル−４−メチルイミダゾールテトラフェニルボレート、Ｎ−メチルモリホリンテトラフェニルボレート等のテトラフェニルボロン塩及びこれらの誘導体等があげられる。これらは、単独でも２種以上併用して用いても良い。
【００２０】
さらに、その他の添加剤として、ブロム化エポキシ樹脂や三酸化アンチモン、リン酸エステル、赤リン及びメラミン樹脂をはじめとする含窒素化合物等の難燃剤、天然ワックス、合成ワックス、酸化または非酸化のポリオレフィン等の離型剤、カーボンブラック等の着色剤、シリコーンオイルやシリコーンゴム粉末等の応力緩和剤、ハイドロタルサイト、アンチモンービスマス等のイオントラップ剤等を必要に応じて用いることができる。
【００２１】
本発明における成形材料は、各種原材料を均一に分散混合できるのであれば、いかなる手法を用いても調製できるが、一般的な手法として、所定の配合量の原材料をミキサー等によって十分混合した後、ミキシングロール、押出機等によって溶融混練した後、冷却、粉砕する方法を挙げることができる。成形条件に合うような寸法及び重量でタブレット化すると使いやすい。
【００２２】
リードフレーム、配線済みのテープキャリア、配線板、ガラス、シリコンウエハなどの支持部材に、半導体チップ、トランジスタ、ダイオード、サイリスタなどの能動素子、コンデンサ、抵抗体、コイルなどの受動素子等の素子を搭載し、必要な部分を本発明の封止用成形材料で封止して、電子部品を製造することができる。このような電子部品としては、たとえば、銅リ−ドフレ−ム上に搭載したチップを本発明の成形材料で封止したＱＦＰや、テープキャリアにバンプで接続した半導体チップを本発明の成形材料で封止したＴＣＰを挙げることができる。また、配線板やガラス上に形成した配線に、ワイヤーボンディング、フリップチップボンディング、はんだなどで接続した半導体チップ、トランジスタ、ダイオード、サイリスタなどの能動素子及び／又はコンデンサ、抵抗体、コイルなどの受動素子を、本発明の成形材料で封止したＣＯＢモジュール、ハイブリッドＩＣ、マルチチップモジュールなどを挙げることができる。
電子部品を封止する方法としては、低圧トランスファー成形法が最も一般的であるが、インジェクション成形法、圧縮成形法等を用いてもよい。
【００２３】
【実施例】
次に本発明の実施例を示すが、本発明の範囲はこれらの実施例に限定されるものではない。
【００２４】
実施例１、２、比較例１〜３
表１に示す配合組成で、各素材を予備混合（ドライブレンド）した後、二軸ロール（ロール表面温度約８０℃）で１０分間混練し、冷却粉砕して、実施例１、２及び比較例１〜３の成形材料を製造した。
エポキシ樹脂としては、エポキシ当量１９６の４，４’−ビス（２，３−エポキシプロポキシ）−３，３’，５，５’−テトラメチルビフェニルを主成分とするエポキシ樹脂（１）と、エポキシ当量３９３、臭素含有率４９％のエピビス型の臭素化エポキシ樹脂を使用し、フェノール樹脂としては、水酸基当量１７１、軟化点６９℃、数平均分子量９００の下記構造式（Ｖ）のフェノールアラルキル樹脂を使用した。
【化１４】

（ここで、ｎは０〜８の正の数を示す。）
【００２５】
【表１】

【００２６】
作製した合計５種類の成形材料を、トランスファー成形機を用い、金型温度１８０℃、 成形圧力７０ｋｇｆ／ｃｍ²、硬化時間９０秒の条件で次の各試験を行い評価した。
（１）スパイラルフロー（流動性の指標）
ＥＭＭＩ−１−６６に準じたスパイラルフロー測定用金型を用いて成形し、流動距離を求めた。
（２）熱時硬度
金型開き直後の成形品硬度をショア−Ｄ型硬度計を用いて測定した。
（３）耐湿性
ＳＯＰ−２８ピンの半導体装置を各成形材料を用いて成形し、１７５℃、５時間後硬化することにより試験用パッケージを作製した。このパッケージを８５℃／８５％ＲＨ／７２時間吸湿＋２１５℃／９０秒（ＶＰＳ）の前処理後、ＰＣＴ（１２１℃／２気圧）に放置してチップ上配線の断線の有無を観察し、断線不良率が５０％に達するまでの時間を調べた。
（４）半田耐熱性
ＱＦＰ８０ピンの樹脂封止型半導体装置（外形寸法２０ｍｍ×１４ｍｍ×２ｍｍ、チップサイズ：８×１０ｍｍ、リードフレーム：ＥＦＴＥＣ６４Ｔ（ステージ加工なし））を用いて、フレームにシリコンチップを銀ペーストにて接着（１３０℃／２ｈｒ硬化）した後さらに２２５℃に保持した熱板上に３分間放置してフレーム表面に酸化膜を形成した。このフレームを実施例及び比較例の成形材料を用いて、金型温度１８０℃、 成形圧力７０ｋｇｆ／ｃｍ²、硬化時間９０秒の条件で成形し、１７５℃、５時間後硬化することにより試験用パッケージを作製した。このパッケージを恒温恒湿槽を用い、８５℃／８５％ＲＨの条件下、所定時間吸湿した後、２４０℃／１０秒の条件で処理した時のクラックの有無を観察し、クラックが発生するまでの吸湿時間を調べた。
（５）酸化膜剥離
上記（４）で作成した試験用パッケージで、後硬化後、超音波探査装置を用いてステージ裏面の剥離の有無を観察し、剥離面積率（％）で評価した。
評価結果を表２に示す。
【００２７】
【表２】

【００２８】
本発明における（Ｃ）成分のシランカップリング剤を含有しない比較例ではいずれも半田耐熱性が劣っている。比較例１及び比較例２ではさらに酸化膜剥離も大きく、耐湿性も劣っている。可撓化剤を添加した比較例３では、剥離防止には効果がみられるものの熱時硬度（成形性）が低く、外観も不良である。
これに対して、（Ａ）〜（Ｄ）成分を全て含む実施例１、２は、流動性、熱時硬度、耐湿性、半田耐熱性、外観のいずれも良好で、剥離防止効果もあった。特に一般式（II）に相当するシラン化合物を添加した実施例２は酸化膜剥離がまったくみられなかった。
【００２９】
【発明の効果】
本発明によって得られる電子部品封止用エポキシ樹脂成形材料は、流動性、成形性等の信頼性に優れているため、電子部品の高生産性に寄与し、また、この成形材料を用いて、銅系リードフレームに搭載された半導体素子を封止して作製した半導体装置は、実施例で示したように耐湿性、半田耐熱性に優れ、酸化膜剥離が抑制されるため、その工業的価値は大である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin composition excellent in moldability and reliability, an epoxy resin molding material for sealing an electronic component, and an electronic component in which an element is sealed with the molding material.
[0002]
[Prior art]
Conventionally, in the field of element sealing of electronic components such as transistors and ICs, resin sealing has been the mainstream from the viewpoint of productivity, cost, and the like, and epoxy resin molding materials have been widely used. This is because the epoxy resin is balanced in various properties such as workability, moldability, electrical properties, moisture resistance, heat resistance, mechanical properties, and adhesiveness with inserts. Further, as a lead frame for mounting an element and securing an electrical contact with the outside, an iron-based material has been mainly used in a surface mounting package.
[0003]
In recent years, products using copper-based lead frames are increasing in terms of heat dissipation and cost. However, copper-based lead frames have advantages in terms of heat dissipation and cost, but have the disadvantage that an oxide film is easily formed on the surface and the strength of the oxide film is very low. Therefore, an oxide film is formed on the surface of the lead frame by heat applied in a process of fixing the element to the lead frame, a process of connecting the element and the lead frame with a gold wire, and the like. When such a lead frame with an oxide film formed on the surface is sealed with a conventional epoxy resin molding material for sealing electronic components, the oxide film peels off due to the stress generated at the interface between the lead frame and the molding material, The reliability as an electronic component was significantly reduced.
[0004]
Various countermeasures have been studied for this problem. For example, the step of fixing the element to the lead frame, the step of connecting the element and the lead frame with a gold wire, etc. are performed in a nitrogen atmosphere or at a relatively low temperature, thereby suppressing formation of an oxide film and preventing peeling. There is a way. These methods are effective in preventing the peeling of the oxide film, but are not practical in that the cost and the connection strength of the gold wire are reduced. A method of improving the heat resistance by coating the surface of the copper frame with plating is also effective but is not practical in terms of cost.
[Problems to be solved by the invention]
[0005]
On the other hand, as an improvement from the epoxy resin molding material for sealing electronic parts, the addition of a flexibilizer, optimization of the amount of filler, review of the release agent, etc. have been proposed. There is nothing that can withstand the requirements of electronic component sealing applications.
In addition, it has already been reported that an epoxy resin composition using a coupling agent containing two alkoxy groups and a γ-glycid group has low corrosiveness to aluminum (Japanese Patent Laid-Open No. 60-179419). However, this limits the functional group to the γ-glycid group, and no mention is made of improving adhesion to copper.
[0006]
From the background as described above, the present invention strongly demands an epoxy resin molding material for electronic component sealing that exhibits the same reliability and moldability as an iron-based lead frame for a copper-based lead frame. .
[Means for Solving the Problems]
[0007]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have recognized a remarkable effect in suppressing the oxide film peeling of the copper-based lead frame by adding a specific coupling agent. The inventors have found that a molding material satisfying the above requirements can be obtained, and have completed the present invention.
[0008]
That is, the present invention
(1) (A) epoxy resin, (B) curing agent, (C) silane coupling agent, and (D) inorganic filler as essential components, and (C) component silane coupling agent is represented by the following general formula (I An epoxy resin composition characterized by being represented by:
[Chemical formula 5]

(Where R ¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to ² carbon atoms, R ² is an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ³ is a methyl group or an ethyl group. N represents a number from 1 to 6.)
(2) The epoxy resin composition according to the above (1), comprising a silane compound represented by the following general formula (II):
[Chemical 6]
(R ¹ ) ₂ —Si— (OR ² ) ₂ (II)
(Here, R ¹ represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, and R ² represents a methyl group or an ethyl group.)
(3) The epoxy resin composition according to the above (1) or (2), comprising an epoxy resin of the following general formula (III):
[Chemical 7]

(Here, R ^{1 to} R ⁴ represent hydrogen or a hydrocarbon having 1 to 10 carbon atoms, and may be the same or different from each other. N represents a positive number of 0 to 3.)
(4) The epoxy resin composition according to any one of the above (1) to (3), comprising a curing agent represented by the following general formula (IV):
[Chemical 8]

(Here, R is hydrogen or a hydrocarbon or halogen having 1 to 10 carbon atoms, and n is a positive number of 0 to 8.)
(5) An epoxy resin molding material for sealing electronic parts, comprising the epoxy resin composition according to any one of (1) to (4) above,
(6) An electronic component obtained by sealing an element with the molding material according to (5) above,
It is.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The epoxy resin of the component (A) used in the present invention is not particularly limited. For example, it is generally used in an epoxy resin molding material for sealing electronic parts, such as a phenol novolac type epoxy resin and an orthocresol novolac type epoxy. Resins, epoxy resins obtained by epoxidizing novolak resins synthesized from phenols and aldehydes, including bisphenol A novolac type epoxy resins, diglycidyl ethers such as bisphenol A, bisphenol F, bisphenol S, alkyl-substituted biphenol Glycidylamine type epoxy resin obtained by reaction of polyamine such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin, epoxidized product of co-condensation resin of dicyclopentadiene and phenol, naphthalene ring Epoxy resin, epoxidized naphthol aralkyl resin, trimethylolpropane type epoxy resin, terpene modified epoxy resin, linear aliphatic epoxy resin obtained by oxidizing olefin bond with peracid such as peracetic acid, and alicyclic epoxy Examples thereof include an epoxy resin represented by the following general formula (III) from the viewpoint of reflow resistance.
[Chemical 9]

(Here, R ^{1 to} R ⁴ represent hydrogen or a hydrocarbon having 1 to 10 carbon atoms, and may be the same or different from each other. N represents a positive number of 0 to 3.)
For example, 4,4′-bis (2,3-epoxypropoxy) biphenyl and 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylbiphenyl Epoxy resin as main component, epichlorohydrin and 4,4′-bis (2,3-epoxypropoxy) biphenol or 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′- Examples thereof include an epoxy resin obtained by reacting with tetramethylbiphenol. Among them, an epoxy resin mainly composed of 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylbiphenyl is preferable.
These epoxy resins can be used alone or in combination of two or more.
[0010]
The curing agent of the component (B) used in the present invention is not particularly limited. For example, it is generally used in an epoxy resin molding material for encapsulating electronic components, such as phenol, cresol, resorcin, catechol, bisphenol A, Resins obtained by condensation or cocondensation of phenols such as bisphenol F or naphthols such as α-naphthol, β-naphthol and dihydroxynaphthalene with aldehydes such as formaldehyde in the presence of an acidic catalyst, phenol aralkyl resins, naphthol There are aralkyl resins and the like. Particularly, from the viewpoint of reflow resistance, a phenol-aralkyl resin represented by the following general formula (IV) is preferable.
[Chemical Formula 10]

(Here, R is hydrogen or a hydrocarbon or halogen having 1 to 10 carbon atoms, and n is a positive number of 0 to 8.)
Among these, those represented by the following formula (V) and those having n of 0 to 8 on average are preferable.
Embedded image

These curing agents can be used alone or in combination of two or more.
[0011]
In addition, the equivalent ratio of the epoxy resin of component (A) and the curing agent of component (B), that is, the ratio of the number of epoxy groups in the epoxy resin / the number of hydroxyl groups in the curing agent is not particularly limited. In order to suppress the minute amount, it is preferable to set in the range of 0.7 to 1.3, and in order to obtain a molding material that is particularly excellent in moldability and reflow resistance, set in the range of 0.8 to 1.2. It is preferable.
[0012]
The (C) component silane coupling agent used in the present invention is represented by the following general formula (I).
Embedded image

(Where R ¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to ² carbon atoms, R ² is an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ³ is a methyl group or an ethyl group. N represents a number from 1 to 6.)
Illustrative examples include γ-anilinopropylmethyldimethoxysilane, γ-anilinopropylmethyldiethoxysilane, γ-anilinomethylmethyldimethoxysilane, γ-anilinomethylmethyldiethoxysilane, N- (p-methoxyphenyl). ) -Γ-aminopropylmethyldimethoxysilane, N- (p-methoxyphenyl) -γ-aminopropylmethyldiethoxysilane, etc., among others, from the viewpoint of adhesion to the lead frame, moisture resistance and package moldability. Γ-anilinopropylmethyldimethoxysilane is preferably used.
[0013]
The amount of the silane coupling agent (C) is preferably 0.2 to 5.0% by weight, more preferably 0.5 to 2.5% with respect to the inorganic filler (D). % By weight. If it is less than 0.2% by weight, the adhesion to the frame tends to be lowered, and if it exceeds 5.0% by weight, the moldability of the package tends to be lowered.
[0014]
In the epoxy resin composition and the epoxy resin molding material for electronic component sealing of the present invention, a conventionally known coupling agent may be used in combination with the silane coupling agent of the component (C). For example, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyl Trimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- [bis (β-hydroxyethyl)] aminopropyltriethoxysilane, N-β- (aminoethyl) -Γ-aminopropyltrimethoxysilane, γ- (β-aminoethyl) aminopropyldimethoxymethylsilane, N- (trimethoxysilylpropyl) ethylenediamine, N- (dimethoxymethylsilylisopropyl) ethylenediamine, Tiltrimethoxysilane, methyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-anilinopropyltri Silane coupling agents such as methoxysilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, or isopropyltriisostearoyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltri (N-aminoethyl-aminoethyl) Titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (di (Cutylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyl diacryl titanate, isopropyltri (dioctylphosphate) One or more titanate coupling agents such as titanate, isopropyl tricumylphenyl titanate, and tetraisopropyl bis (dioctyl phosphite) titanate can be used in combination.
[0015]
The inorganic filler of the component (D) in the present invention is not particularly limited, but includes fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, aluminum nitride, boron nitride, beryllia, zirconia and the like. One or more kinds of powders, beads obtained by spheroidizing them, potassium titanate, silicon carbide, silicon nitride, alumina and other single crystal fibers, glass fibers, and the like can be blended and used. Furthermore, examples of the inorganic filler having a flame retardant effect include aluminum hydroxide, magnesium hydroxide, zinc borate and the like, and these can be used alone or in combination. Among the inorganic fillers, fused silica is preferable from the viewpoint of reducing the linear expansion coefficient, and alumina is preferable from the viewpoint of high thermal conductivity. The shape of the filler is preferably spherical or nearly spherical from the viewpoint of fluidity during molding and mold wear, and particularly preferably 50% by weight or more is spherical.
[0016]
The blending amount of the inorganic filler (D) is preferably 70% by weight or more, particularly preferably 85 to 95% by weight, based on the whole molding material, from the viewpoint of hygroscopicity, reduction of linear expansion coefficient and improvement of strength. . If it is less than 85% by weight, the reflow resistance tends to decrease, and if it exceeds 95% by weight, the fluidity tends to be insufficient. Among these, the range of 88 to 92% by weight is more preferable.
[0017]
In addition to the components (A) to (D), a silane compound represented by the following general formula (II) can be used in the epoxy resin composition and the epoxy resin molding material for sealing electronic parts of the present invention.
Embedded image
(R ¹ ) ₂ —Si— (OR ² ) ₂ (II)
(Here, R ¹ represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, and R ² represents a methyl group or an ethyl group.)
The silane compound represented by the general formula (II) is effective in suppressing oxide film peeling and improving solder heat resistance. Illustrative examples include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, and the like, with dimethyldimethoxysilane being particularly preferred.
[0018]
The amount of the silane compound of the general formula (II) is preferably set so that the ratio ((C) / (II)) to the component (C) is 0.5 to 10, more preferably 1 to 5. If it is less than 0.5, the adhesion to the frame tends to be lowered, and if it exceeds 10, moisture resistance reliability tends to be lowered.
[0019]
A curing accelerator can also be used in the epoxy resin composition and the epoxy resin molding material for sealing electronic parts of the present invention. For example, 1,8-diaza-bicyclo (5,4,0) undecene-7,1,5-diaza-bicyclo (4,3,0) nonene, 5,6-dibutylamino-1,8-diaza-bicyclo ( 5,4,0) undecene-7, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tertiary amines such as tris (dimethylaminomethyl) phenol and their derivatives, 2-methylimidazole, 2-phenylimidazole, Imidazoles such as 2-phenyl-4-methylimidazole and derivatives thereof, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine, and maleic anhydride, benzoquinone, Diazophenyl meta Phosphorus compounds having intramolecular polarization formed by adding a compound having a π bond such as tetraphenylphosphonium tetraphenyl borate, triphenylphosphine tetraphenyl borate, 2-ethyl-4-methylimidazole tetraphenyl borate, N-methyl molybdate Examples thereof include tetraphenylboron salts such as holin tetraphenylborate and derivatives thereof. These may be used alone or in combination of two or more.
[0020]
In addition, flame retardants such as brominated epoxy resins, antimony trioxide, phosphate esters, red phosphorus and melamine resins, and other nitrogen-containing compounds, natural waxes, synthetic waxes, oxidized or non-oxidized polyolefins Release agents such as carbon black, colorants such as carbon black, stress relaxation agents such as silicone oil and silicone rubber powder, ion trapping agents such as hydrotalcite and antimony bismuth, and the like can be used as necessary.
[0021]
The molding material in the present invention can be prepared by any method as long as various raw materials can be uniformly dispersed and mixed, but as a general method, after sufficiently mixing raw materials of a predetermined blending amount with a mixer or the like, A method of cooling and pulverizing after melt-kneading with a mixing roll, an extruder or the like can be mentioned. It is easy to use if it is tableted with dimensions and weight that match the molding conditions.
[0022]
Mounting elements such as semiconductor chips, transistors, diodes, thyristors and other active elements, capacitors, resistors, passive elements such as coils, etc. on support members such as lead frames, wired tape carriers, wiring boards, glass and silicon wafers And an electronic component can be manufactured by sealing a necessary part with the molding material for sealing of the present invention. As such an electronic component, for example, a QFP in which a chip mounted on a copper lead frame is sealed with a molding material of the present invention, or a semiconductor chip connected to a tape carrier with a bump by the molding material of the present invention. A sealed TCP can be mentioned. Also, active elements such as semiconductor chips, transistors, diodes, thyristors and / or passive elements such as capacitors, resistors, coils, etc. connected to wiring formed on wiring boards or glass by wire bonding, flip chip bonding, solder, etc. Can be mentioned COB modules, hybrid ICs, multichip modules and the like sealed with the molding material of the present invention.
As the method for sealing the electronic component, the low-pressure transfer molding method is the most common, but an injection molding method, a compression molding method, or the like may be used.
[0023]
【Example】
Examples of the present invention are shown below, but the scope of the present invention is not limited to these examples.
[0024]
Examples 1 and 2 and Comparative Examples 1 to 3
Examples 1, 2 and Comparative Examples were prepared by premixing (dry blending) each material with the composition shown in Table 1, then kneading for 10 minutes with a biaxial roll (roll surface temperature of about 80 ° C.), cooling and pulverizing. 1-3 molding materials were produced.
Examples of the epoxy resin include an epoxy resin (1) mainly composed of 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylbiphenyl having an epoxy equivalent of 196; An epibis brominated epoxy resin having an equivalent weight of 393 and a bromine content of 49% is used. As a phenol resin, a phenol aralkyl resin of the following structural formula (V) having a hydroxyl equivalent weight of 171 and a softening point of 69 ° C. and a number average molecular weight of 900 is used. used.
Embedded image

(Here, n represents a positive number from 0 to 8.)
[0025]
[Table 1]

[0026]
A total of five types of molding materials thus prepared were evaluated by the following tests using a transfer molding machine under conditions of a mold temperature of 180 ° C., a molding pressure of 70 kgf / cm ² , and a curing time of 90 seconds.
(1) Spiral flow (fluidity index)
Molding was performed using a spiral flow measurement mold according to EMMI-1-66, and the flow distance was determined.
(2) Hardness at heat The hardness of the molded product immediately after opening the mold was measured using a Shore-D hardness meter.
(3) A test package was prepared by molding a moisture-resistant SOP-28 pin semiconductor device using each molding material and post-curing at 175 ° C. for 5 hours. This package is pretreated for 85 ° C / 85% RH / 72 hours moisture absorption + 215 ° C / 90 seconds (VPS), and then left in PCT (121 ° C / 2 atm) to observe the presence or absence of wire breakage on the chip. The time until the defective rate reached 50% was examined.
(4) Solder heat resistance QFP 80 pin resin-encapsulated semiconductor device (outer dimensions 20 mm × 14 mm × 2 mm, chip size: 8 × 10 mm, lead frame: EFTEC64T (without stage processing)) After bonding with silver paste (curing at 130 ° C./2 hr), it was left on a hot plate maintained at 225 ° C. for 3 minutes to form an oxide film on the frame surface. This frame was molded using the molding materials of Examples and Comparative Examples under the conditions of a mold temperature of 180 ° C., a molding pressure of 70 kgf / cm ² and a curing time of 90 seconds, and post-cured at 175 ° C. for 5 hours. A package was produced. Using this thermostatic chamber, the package was moisture-absorbed for a predetermined time under the condition of 85 ° C./85% RH, and then observed for cracks when treated under the condition of 240 ° C./10 seconds until the crack was generated. The moisture absorption time was examined.
(5) Oxide film peeling With the test package created in the above (4), after post-curing, the presence or absence of peeling of the back surface of the stage was observed using an ultrasonic probe, and the peeled area ratio (%) was evaluated.
The evaluation results are shown in Table 2.
[0027]
[Table 2]

[0028]
In the comparative examples not containing the silane coupling agent of component (C) in the present invention, the solder heat resistance is inferior. In Comparative Example 1 and Comparative Example 2, the oxide film is further peeled off and the moisture resistance is inferior. In Comparative Example 3 to which a flexibilizer is added, although an effect is seen in preventing peeling, the hot hardness (formability) is low and the appearance is poor.
On the other hand, Examples 1 and 2 including all of the components (A) to (D) were good in fluidity, heat hardness, moisture resistance, solder heat resistance, and appearance, and had an anti-peeling effect. . In particular, in Example 2 to which a silane compound corresponding to the general formula (II) was added, no oxide film peeling was observed.
[0029]
【The invention's effect】
The epoxy resin molding material for electronic component sealing obtained by the present invention is excellent in reliability such as fluidity and moldability, and thus contributes to high productivity of electronic components. A semiconductor device manufactured by sealing a semiconductor element mounted on a copper-based lead frame is excellent in moisture resistance and soldering heat resistance as shown in the examples, and its oxide film peeling is suppressed. Is great.

Claims (4)

(A) An epoxy resin, (B) a curing agent, (C) a silane coupling agent, and (D) an inorganic filler are essential components, and the (C) component silane coupling agent is represented by the following general formula (I). And

(Wherein R ¹ is hydrogen, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to ² carbon atoms, R ² is an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ³ is a methyl group or an ethyl group. N represents a number from 1 to 6.)
Furthermore, the epoxy resin composition for electronic component sealing used for the copper-type lead frame characterized by including the silane compound represented by the following general formula (II).
[Chemical formula 2]
(R ¹ ) ₂ —Si— (OR ² ) ₂ (II)
(Here, R ¹ represents an alkyl group having 1 to 10 carbon atoms or a phenyl group, and R ² represents a methyl group or an ethyl group.) The epoxy resin composition according to claim 1, comprising an epoxy resin represented by the following general formula (III).

(Here, R ^{1 to} R ⁴ represent hydrogen or a hydrocarbon having 1 to 10 carbon atoms, and may be the same as or different from each other. N represents a positive number from 0 to 3.) The epoxy resin composition according to claim 1 or 2, comprising a curing agent of the following general formula (IV).

(Here, R is hydrogen or a hydrocarbon or halogen having 1 to 10 carbon atoms, and n is a positive number of 0 to 8.) The electronic component obtained by sealing an element with the epoxy resin composition in any one of Claims 1-3 .