JP4168368B2 - Adhesive sheet, semiconductor device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet acting as a dicing tape in a dicing process and having excellent connection reliability in a connecting process between a semiconductor element and a supporting member, wherein the adhesive sheet has heat resistance and moisture resistance which are required the when mounting the semiconductor element to the supporting member for mounting it that has a large difference of a coefficient of thermal expansion therebetween and has excellent workability, and to provide a method for manufacturing a semiconductor device capable of simplifying manufacturing processes. <P>SOLUTION: The adhesive sheet which is radiation and thermally polymerizable comprises (1) a tacky adhesive layer composed of (A) a polyimide resin, (B) an epoxy resin and a curing agent for the epoxy resin, and (C) a compound generating a base when irradiated by a radiation, (2) an adhesive layer composed of (A) a polyimide resin, (B) an epoxy resin and a curing agent for the epoxy resin, and (3) a base material. <P>COPYRIGHT: (C)2003,JPO

Description

（式中、R_１及びR_２は炭素原子数１〜３０の二価の炭化水素基を示し、それぞれ同一でも異なっていてもよく、R_３及びR_４は一価の炭化水素基を示し、それぞれ同一でも異なっていてもよく、ｍは１以上の整数である）
【００１６】
で表されるジアミノポリシロキサン、１，３−ビス（アミノメチル）シクロヘキサン、サン テクノケミカル（株）製 ジェファーミン D−２３０，Ｄ−４００，Ｄ−２０００，Ｄ−４０００，ＥＤ−６００，ＥＤ−９００，ＥＤ−２００１，ＥＤＲ−１４８等のポリオキシアルキレンジアミン等の脂肪族ジアミン等を使用することができ、これらの１種または２種以上を併用することもできる。
【００１７】
本発明に使用するエポキシ樹脂は、硬化して接着作用を呈するものであれば特に制限は無く、例えば、油化シェルエポキシ（株）製 エピコート８０７，８１５，８２５，８２７，８２８，８３４，１００１，１００４，１００７，１００９、ダウケミカル社製 ＤＥＲ−３３０，３０１，３６１、東都化成（株）製 ＹＤ８１２５，ＹＤＦ８１７０等のビスフェノールＡ型エポキシ樹脂、油化シェルエポキシ（株）製 エピコート１５２，１５４、日本化薬（株）製 ＥＰＰＮ−２０１、ダウケミカル社製 ＤＥＮ−４３８等のフェノールノボラック型エポキシ樹脂、日本化薬（株）製 ＥＯＣＮ−１０２Ｓ，１０３Ｓ，１０４Ｓ，１０１２，１０２５，１０２７、東都化成（株）製 ＹＤＣＮ７０１，７０２，７０３，７０４等のｏ−クレゾールノボラック型エポキシ樹脂、油化シェルエポキシ（株）製 Ｅｐｏｎ １０３１Ｓ、チバスペシャリティーケミカルズ社製 アラルダイト０１６３、ナガセ化成（株）製 デナコールＥＸ−６１１，６１４，６１４Ｂ，６２２，５１２，５２１，４２１，４１１，３２１等の多官能エポキシ樹脂、油化シェルエポキシ（株）製 エピコート６０４、東都化成（株）製 ＹＨ−４３４、三菱ガス化学（株）製 ＴＥＴＲＡＤ−Ｘ，ＴＥＴＲＡＤ−Ｃ、住友化学（株）製 ＥＬＭ−１２０等のアミン型エポキシ樹脂、チバスペシャリティーケミカルズ社製 アラルダイトＰＴ８１０等の複素環含有エポキシ樹脂、ＵＣＣ社製 ＥＲＬ４２３４，４２９９，４２２１，４２０６等の脂環式エポキシ樹脂などを使用することができ、これらの１種又は２種以上を併用することもできる。
【００１８】
エポキシ樹脂の硬化剤は、エポキシ樹脂の硬化剤として通常用いられているものを使用でき、アミン、ポリアミド、酸無水物、ポリスルフィド、三ふっ化ほう素、フェノール性水酸基を１分子中に２個以上有する化合物であるビスフェノールＡ、ビスフェノールＦ、ビスフェノールＳ、多官能フェノール及びフェノールノボラック樹脂、ビスフェノールＡノボラック樹脂、ナフトールノボラック樹脂またはクレゾールノボラック樹脂等のフェノール樹脂等のフェノール類などが挙げられるが、特に吸湿時の耐電食性に優れるため、フェノール類を使用するのが好ましい。
本発明に使用する（Ｃ）放射線照射によって塩基を発生する化合物をは、放射線照射時に塩基を発生する化合物であれば特に制限は受けない。発生する塩基としては、反応性、硬化速度の点から強塩基性化合物が好ましい。一般的には、塩基性の指標として酸解離定数の対数であるｐＫａ値が使用され、水溶液中でのｐＫａ値が7以上の塩基が好ましく、さらに９以上の塩基がより好ましい。
このような塩基性を示す例としては、イミダゾール、２，４−ジメチルイミダゾール、１−メチルイミダゾール等のイミダゾール誘導体、ピペラジン、２，５−ジメチルピペラジン等のピペラジン誘導体、ピペリジン、1，2-ジメチルピペリジン等のピペリジン誘導体、プロリン誘導体、トリメチルアミン、トリエチルアミン、トリエタノールアミン等のトリアルキルアミン誘導体、4-メチルアミノピリジン、４-ジメチルアミノピリジン等の４位にアミノ基またはアルキルアミノ基が置換したピリジン誘導体、ピロリジン、ｎ−メチルピロリジン等のピロリジン誘導体、トリエチレンジアミン、１，８−ジアザビスシクロ（５，４，０）ウンデセン−１(ＤＢＵ)等の脂環式アミン誘導体、ベンジルメチルアミン、ベンジルジメチルアミン、ベンジルジエチルアミン等のベンジルアミン誘導体等が挙げられる。
【００１９】
前記塩基性化合物を放射線照射によって発生するものとしては、例えば、Ｊｏｕｒｎａｌ ｏｆ Ｐｈｏｔｏｐｏｌｙｍｅｒ Ｓｃｉｅｎｃｅ ａｎｄ Ｔｅｃｈｎｏｌｏｇｙ １２巻、３１３〜３１４項（１９９９年）やＣｈｅｍｉｓｔｒｙ ｏｆ Ｍａｔｅｒｉａｌｓ １１巻、１７０〜１７６項（１９９９年）等に記載されている４級アンモニウム塩誘導体を用いることができる。これらは、活性光線の照射により高塩基性のトリアルキルアミンを生成するため、エポキシ樹脂の硬化には最適である。
また、Ｊｏｕｒｎａｌ ｏｆ Ａｍｅｒｉｃａｎ ＣｈｅｍｉｃａｌＳｏｃｉｅｔｙ １１８巻 １２９２５頁（１９９６年）やＰｏｌｙｍｅｒ Ｊｏｕｒｎａｌ ２８巻 ７９５頁（１９９６年）等に記載されているカルバミン酸誘導体を用いることができる。
また、活性光線の照射により１級のアミノ基を発生するオキシム誘導体、光ラジカル発生剤として市販されている２-メチル-1（４-(メチルチオ)フェニル）-2-モルフォリノプロパン-1-オン（Ｃｉｂａ Ｓｐｅｃｉａｌｉｔｙ Ｃｈｅｍｉｃａｌｓ社製イルガキュア９０７）、２-ベンジル-２-ジメチルアミノ-1-（4-モルフォリノフェニル）-ブタノン-1-オン（Ｃｉｂａ Ｓｐｅｃｉａｌｉｔｙ Ｃｈｅｍｉｃａｌｓ社製イルガキュア３６９）、ヘキサアリールビスイミダゾール誘導体(ハロゲン、アルコキシ基、ニトロ基、シアノ基等の置換基がフェニル基に置換されていてもよい)、ベンゾイソオキサゾロン誘導体等を用いることができる。
前記活性光線による塩基発生剤の他に、光フリース転位、光クライゼン転位(光Cleisen転位)やクルチウス転位(Curtius転位)、スチーブンス転位(Stevens転位)によって塩基性化合物を発生させ、エポキシ樹脂の硬化を行うことができる。
前記塩基発生剤は、分子量５００以下の低分子化合物として用いる他、高分子の主鎖及び側鎖に導入した化合物を用いても良い。この場合の分子量としては、粘接着剤としての粘接着性、流動性の観点から重量平均分子量１,０００〜１００,０００が好ましく、より好ましくは５,０００〜３０,０００である。
これらの化合物は、室温で放射線を照射しない状態ではエポキシ樹脂と反応性を示さないため、室温での貯蔵安定性は非常に優れているという特徴を持つ。
【００２０】
本発明の（１）粘接着層および（２）接着層の膜厚の比は、（１）粘接着層／（２）接着層＝０．０１〜０．５であり、好ましくは０．０２〜０．３であり、さらに好ましくは０．０３〜０．２である。０．０１以下だと粘接着層と基材の粘着力が低下する傾向があり、０．５以上だとコストが高くなる傾向がある。
【００２１】
また、本発明の接着シートを形成する粘接着層および接着層には、硬化促進剤を添加することもできる。硬化促進剤には、特に制限が無く、イミダゾール類、ジシアンジアミド誘導体、ジカルボン酸ジヒドラジド、トリフェニルホスフィン、テトラフェニルホスホニウム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、１，８−ジアザビシクロ（５，４，０）ウンデセン−７−テトラフェニルボレート等を用いることができる。これらは単独でまたは２種類以上を組み合わせて使用することができる。
【００２２】
硬化促進剤の添加量は、（Ｂ）エポキシ樹脂及びエポキシ硬化剤１００重量部に対して０．１〜５重量部が好ましく、０．２〜３重量部がより好ましい。添加量が０．１重量部未満であるとると硬化性が劣る傾向があり、５重量部を超えると保存安定性が低下する傾向がある。
【００２３】
本発明の接着シートを形成する粘接着層および接着層には、可とう性や耐リフロークラック性を向上させる目的で、エポキシ樹脂と相溶性がある高分子量樹脂を添加することができる。このような高分子量樹脂としては、特に限定されず、たとえばフェノキシ樹脂、高分子量エポキシ樹脂、超高分子量エポキシ樹脂などが挙げられる。これらは、単独でまたは２種類以上を組み合わせて使用することもできる。
【００２４】
エポキシ樹脂と相溶性がある高分子量樹脂の使用量は、エポキシ樹脂およびエポキシ樹脂硬化剤１００重量部に対して、４０重量部以下とすることが好ましい。この範囲であると、エポキシ樹脂層のＴｇを確保できる。
【００２５】
また、本発明の接着シートを形成する粘接着層および接着層には、その取り扱い性向上、熱伝導性向上、溶融粘度の調整およびチキソトロピック性付与などを目的として、無機フィラーを添加することもできる。無機フィラーとしては、特に制限はなく、例えば、水酸化アルミニウム、水酸化マグネシウム、炭酸カルシウム、炭酸マグネシウム、ケイ酸カルシウム、ケイ酸マグネシウム、酸化カルシウム、酸化マグネシウム、酸化アルミニウム、窒化アルミニウム、ほう酸アルミウイスカ、窒化ほう素、結晶性シリカ、非晶性シリカ等が挙げられ、フィラーの形状は特に制限されるものではない。これらのフィラーは単独で又は二種類以上を組み合わせて使用することができる。
【００２６】
中でも、熱伝導性向上のためには、酸化アルミニウム、窒化アルミニウム、窒化ほう素、結晶性シリカ、非晶性シリカ等が好ましい。また、溶融粘度の調整やチキソトロピック性の付与の目的には、水酸化アルミニウム、水酸化マグネシウム、炭酸カルシウム、炭酸マグネシウム、ケイ酸カルシウム、ケイ酸マグネシウム、酸化カルシウム、酸化マグネシウム、酸化アルミニウム、結晶性シリカ、非晶性シリカなどが好ましい。
【００２７】
無機フィラーの使用量は、粘接着層あるいは接着層１００重量部に対して１〜２０重量部が好ましい。１重量部未満だと添加効果が得られない傾向があり、２０重量部を超えると、粘接着層あるいは接着層の貯蔵弾性率の上昇、粘接着性の低下、ボイド残存による電気特性の低下等の問題を起こす傾向がある。
【００２８】
また、本発明の接着シートを形成する粘接着層および接着層には、異種材料間の界面結合を良くするために、各種カップリング剤を添加することもできる。カップリング剤としては、例えば、シラン系、チタン系、アルミニウム系等が挙げられ、中でも効果が高い点でシラン系カップリング剤が好ましい。
【００２９】
上記シラン系カップリング剤としては、特に制限はなく、例えば、ビニルトリクロルシラン、ビニルトリス（β−メトキシエトキシ）シラン、ビニルトリエトキシシラン、ビニルトリメトキシシラン、γ−メタクリロキシプロピルトリメトキシシラン、γ−メタクリロキシプロピルメチルジメトキシシラン、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、γ−グリシドキシプロピルメチルジメトキシシラン、γ−グリシドキシプロピルメチルジエトキシシラン、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、Ｎ−β（アミノエチル）γ−アミノプロピルメチルジメトキシシラン、γ−アミノプロピルトリエトキシシラン、Ｎ−フェニル−γ−アミノプロピルトリメトキシシラン、γ−メルカプトプロピルトリメトキシシラン、γ−メルカプトプロピルトリエトキシシラン、３−アミノプロピルメチルジエトキシシラン、３−ウレイドプロピルトリエトキシシラン、３−ウレイドプロピルトリメトキシシラン、３−アミノプロピルトリメトキシシラン、３−アミノプロピル−トリス（２−メトキシ−エトキシ−エトキシ）シラン、Ｎ−メチル−３−アミノプロピルトリメトキシシラン、トリアミノプロピルトリメトキシシラン、３−４，５−ジヒドロイミダゾール−１−イル−プロピルトリメトキシシラン、３−メタクリロキシプロピル−トリメトキシシラン、３−メルカプトプロピルメチルジメトキシシラン、３−クロロプロピルメチルジメトキシシラン、３−クロロプロピルジメトキシシラン、３−シアノプロピルトリエトキシシラン、ヘキサメチルジシラザン、Ｎ，Ｏ−ビス（トリメチルシリル）アセトアミド、メチルトリメトキシシラン、メチルトリエトキシシラン、エチルトリクロロシラン、ｎ−プロピルトリメトキシシラン、イソブチルトリメトキシシラン、アミルトリクロロシラン、オクチルトリエトキシシラン、フェニルトリメトキシシラン、フェニルトリエトキシシラン、メチルトリ（メタクリロイルオキエトキシ）シラン、メチルトリ（グリシジルオキシ）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、オクタデシルジメチル〔３−（トリメトキシシリル）プロピル〕アンモニウムクロライド、γ−クロロプロピルメチルジクロロシラン、γ−クロロプロピルメチルジメトキシシラン、γ−クロロプロピルメチルジエトキシシラン、トリメチルシリルイソシアネート、ジメチルシリルイソシアネート、メチルシリルトリイソシアネート、ビニルシリルトリイソシアネート、フェニルシリルトリイソシアネート、テトライソシアネートシラン、エトキシシランイソシアネートなどを使用することができ、単独で又は二種類以上を組み合わせて使用することができる。
【００３０】
また、チタン系カップリング剤としては、例えば、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、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、イソプロピルトリス（ｎ−アミノエチル）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、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、ジクミルフェニル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）オキシアセテートチタネート、テトライソプロピルチタネート、テトラノルマルブチルチタネート、ブチルチタネートダイマー、テトラ（２−エチルヘキシル）チタネート、チタンアセチルアセトネート、ポリチタンアエチルアセトネート、チタンオクチレングリコレート、チタンラクテートアンモニウム塩、チタンラクテート、チタンラクテートエチルエステル、チタンチリエタノールアミネート、ポリヒドロキシチタンステアレート、テトラメチルオルソチタネート、テトラエチルオルソチタネート、テタラプロピルオルソチタネート、テトライソブチルオルソチタネート、ステアリルチタネート、クレシルチタネートモノマー、クレシルチタネートポリマー、ジイソプロポキシ−ビス（２，４−ペンタジオネート）チタニウム（ＩＶ）、ジイソプロピル−ビス−トリエタノールアミノチタネート、オクチレングリコールチタネート、テトラ−ｎ−ブトキシチタンポリマー、トリ−ｎ−ブトキシチタンモノステアレートポリマー、トリ−ｎ−ブトキシチタンモノステアレートなどを使用することができ、単独で又は二種類以上を組み合わせて使用することができる。
【００３１】
アルミニウム系カップリング剤としては、例えば、エチルアセトアセテートアルミニウムジイソプロピレート、アルミニウムトイス（エチルアセトアセテート）、アルキルアセトアセテートアルミニウムジイソプロピレート、アルミニウムモノアセチルアセテートビス（エチルアセトアセテート）、アルミニウムトリス（アセチルアセトネート）、アルミニウム＝モノイソプロポキシモノオレオキシエチルアセトアセテート、アルミニウム−ジ−ｎ−ブトキシドモノエチルアセトアセテート、アルミニウム−ジ−ｉｓｏ−プロポキシド−モノエチルアセトアセテート等のアルミニウムキレート化合物、アルミニウムイソプロピレート、モノ−ｓｅｃ−ブトキシアルミニウムジイソプロピレート、アルミニウム−ｓｅｃ−ブチレート、アルミニウムエチレート等のアルミニウムアルコレートなどを使用することができ、単独で又は二種類以上を組み合わせて使用することができる。
【００３２】
上記カップリング剤の使用量は、その効果や耐熱性及びコストの面から、（Ａ）ポリイミド樹脂およびエポキシ樹脂硬化剤１００重量部に対して、０．０１〜１０重量部とするのが好ましい。
【００３３】
本発明の接着シートを形成する粘接着層および接着層には、イオン性不純物を吸着して、吸湿時の絶縁信頼性をよくするために、さらにイオン捕捉剤を添加することもできる。このようなイオン捕捉剤としては、特に制限はなく、例えば、トリアジンチオール化合物、ビスフェノール系還元剤等の、銅がイオン化して溶け出すのを防止するため銅害防止剤として知られる化合物、ジルコニウム系、アンチモンビスマス系マグネシウムアルミニウム化合物等の無機イオン吸着剤などが挙げられる。
【００３４】
上記イオン捕捉剤の使用量は、添加による効果や耐熱性、コスト等の点から、（Ａ）ポリイミド樹脂１００重量部に対して、０．１〜１０重量部が好ましい。
【００３５】
本発明接着シートは、接着シートを形成する組成物を溶剤に溶解あるいは分散してワニスとし、基材フィルム上に塗布、加熱し溶剤を除去することによって得ることができる。
【００３６】
本発明の接着シートに用いる基材としては、特に制限は無く、例えば、ポリテトラフルオロエチレンフィルム、ポリエチレンテレフタレートフィルム、ポイエチレンフィルム、ポリプロピレンフィルム、ポリメチルペンテンフィルム、ポリイミドフィルムなどのプラスチックフィルム等が挙げられる。
【００３７】
本発明の接着シートは、ダイシング工程終了後、放射線を接着シートに照射し、放射線重合性を有する接着シートを重合硬化せしめ、接着シートと基材界面の接着力を低下させて半導体素子のピックアップを可能にするものである。
【００３８】
本発明接着シートは、接着シートを形成する組成物を溶剤に溶解あるいは分散してワニスとし、基材フィルム上に塗布、加熱し溶剤を除去することによって得ることができる。
【００３９】
また、上記のワニス化するための溶剤としては、特に限定されないが、フィルム作製時の揮発性などを考慮すると、たとえば、メタノール、エタノール、２−メトキシエタノール、２−エトキシエタノール、２−ブトキシエタノール、メチルエチルケトン、アセトン、メチルイソブチルケトン、トルエン、キシレンなどの比較的低沸点の溶媒を使用するのが好ましい。また、塗膜性を向上させるなどの目的で、たとえば、ジメチルアセトアミド、ジメチルホルムアミド、Ｎ−メチルピロリドン、シクロヘキサノンなどの比較的高沸点の溶媒を使用することもできる。これらの溶媒は、単独でまたは２種類以上を組み合わせて使用することができる。
【００４０】
無機フィラーを添加した際のワニスの製造には、無機フィラーの分散性を考慮して、らいかい機、３本ロール、ボールミル及びビーズミルなどを使用するのが好ましく、また、これらを組み合わせて使用することもできる。また、無機フィラーと低分子量の原料をあらかじめ混合した後、高分子量の原料を配合することによって、混合する時間を短縮することもできる。また、ワニスとした後、真空脱気等によってワニス中の気泡を除去することもできる。
【００４１】
基材フィルムへのワニスの塗布方法としては、公知の方法を用いることができ、例えば、ナイフコート法、ロールコート法、スプレーコート法、グラビアコート法、バーコート法、カーテンコート法等が挙げられる。
【００４２】
接着シートの厚みは、特に制限はないが、接着層、基材層ともに５〜２５０μｍが好ましい。５μｍより薄いと応力緩和効果が乏しくなる傾向があり、２５０μｍより厚いと経済的でなくなる上に、半導体装置の小型化の要求に応えられない。
【００４３】
また、本発明の接着シートは、所望のシート厚を得るために、さらに１又は２以上の粘接着層又は接着層を半導体ウェハと接着層との間に挟むように設けてもよい。この場合、前記所望により設けられる接着剤層として、前記の方法によって調製されたものの他に、従来公知の方法によって調製されたものを用いることができる。前記所望により設けられる接着層として、商業的に入手可能な接着シート、例えば、ポリイミド系、シリコンオリゴマー系、ゴム−エポキシ系、エポキシ系接着剤を用いることができる。但し、粘接着剤あるいは接着剤同士、または粘接着剤と接着剤の剥離が発生しないような貼り合わせ条件を従来公知の技術に基づいて考慮する必要がある。
【００４４】
以上説明したような構成の接着シートに放射線照射すると、放射線照射後には基材と接着シート界面の粘着力は大きく低下し、容易に半導体素子に接着層を保持したまま該接着シートの基材フィルムからピックアップすることができる。
【００４５】
本発明の接着シートの粘接着層は、放射線照射のみで基材の接着力を低下させる方法以外に放射線照射と同時あるいは放射線照射後に硬化反応を促進する目的で加熱を併用しても良い。加熱を併用することにより、より低温短時間での接着力低下が可能となる。加熱温度は、粘接着層の分解点以下であれば特に制限は受けないが、５０〜１７０℃の温度が好ましい。
【００４６】
次に、本発明に係る接着シートの使用方法について説明する。基材フィルム１および４上にそれぞれ別個に粘接着剤および接着剤を塗布し、基材フィルムを備えた粘接着層（図１）および基材フィルムを備えた接着層（図２）を作製した後、上記２層を積層して接着シート（図３）を得る方法を使用することもできるし、基材フィルムを備えた粘接着層（図１）上に接着層のワニスを塗布する方法および基材フィルムを備えた接着層（図２）上に粘接着層のワニスを塗布する方法を使用することもできる。上記基材フィルムを備えた粘接着層（図１）および基材フィルムを備えた接着層（図２）を作製した後、上記２層を積層して接着シート（図３）を得る方法を選択した場合、その後半導体ウエハを貼着する工程において、基材フィルム４を剥離するので、基材フィルム１／粘接着剤界面、粘接着剤／接着剤界面に比べ、基材フィルム４／接着剤界面の粘着性が最も小さくなるよに基材フィルムを選択することが重要になる。図４に示すようにして、この粘接着層の上面にダイシング加工すべき半導体ウエハＡを貼着した後、この貼着状態で半導体ウエハＡに図５のようにダイシング、洗浄、乾燥の工程が加えられる。この際、接着層３により半導体ウエハＡは接着シートに充分に粘着保持されているので、上記各工程の間に半導体ウエハＡが脱落することはない。
【００４７】
次に、図６に示すように、放射線Ｂを接着シートの粘接着層２に照射し、放射線重合性を有する接着シートの一部又は大部分を重合硬化せしめる。この際、放射線照射と同時あるいは放射線照射後に硬化反応を促進する目的で加熱を併用しても良い。加熱を併用することにより、より低温短時間での接着力低下が可能となる。加熱温度は、粘接着層の熱分解温度以下であれば特に制限は受けないが、５０〜１７０℃の温度が好ましい。
【００４８】
接着シートへの放射線照射は、基材フィルム１の粘接着層２が設けられていない面から行う。したがって前述のように、放射線としてＵＶを用いる場合には基材フィルム１は光透過性であることが必要であるが、放射線としてＥＢを用いる場合には基材フィルム２は必ずしも光透過性である必要はない。
【００４９】
放射線照射後、ピックアップすべき半導体素子Ａ１、Ａ２、Ａ３を例えば吸引コレット４によりピックアップする。この際、ピックアップすべき半導体素子Ａ１、Ａ２、Ａ３を基材フィルム１の下面から、例えば針扞等により突き上げることもできる。半導体素子Ａ１と接着層３との間の粘着力は、粘接着層２と基材フィルム１との間の粘着力よりも大きいため、半導体素子Ａ１のピックアップを行うと、粘接着層２および接着層３は半導体素子Ａ１の下面に付着した状態で剥離する（図８参照）。次いで、半導体素子を粘接着層２および接着層３を介して半導体素子搭載用支持部材５に載置し加熱する。加熱により粘接着層２および接着層３は接着力が発現し、半導体素子と半導体素子搭載用支持部材との接着が完了する（図９参照）。
【００５０】
【実施例】
以下、本発明を実施例により詳細に報告する。本発明は、これらに限定されるものではない。
（合成例１）
２−ニトロベンジルアルコール３０ｇをテトラヒドロフラン３００ｇ中に室温でマグネチックスターラーを用いてかくはんして溶解させた。この溶液に、予め混合しておいた４，４'−ジフェニルメタンジイソシアネート２４．５ｇ、テトラヒドロフラン１００ｇからなる溶液を３０分かけて滴下し、室温で１時間かくはんした。この後、リービッヒ冷却管をセットし、オイルバスにて６０℃に加熱しながら２時間反応させた。反応後、室温まで冷却し、ロータリーエバポレーターを用いて反応液が半分になるまで濃縮した。
【００５１】
得られた濃縮液を１０００重量部のｎ−へキサン中に添加すると、白色沈殿物を得た。この沈殿物を吸引ろ過し、真空下６０℃で一晩乾燥して目的の２−ニトロベンジルカルバミン酸誘導体を得た。収量４９．５ｇ（収率９１％）であった。
（合成例２）
ｐ−ニトロ安息香酸メチルエステル（２．００ｇ、１１ｍｍｏｌ）、Ｎ，Ｎ−ジメチルヒドラジン（０．６６ｇ、１１ｍｍｏｌ）、フェニルグリシジルエーテル（１．６６ｇ、１１ｍｍｏｌ）をｔｅｒｔ−ブタノール（１５．０ｇ）に添加し、５０℃で１０時間攪拌した後、さらに室温（２５℃）で４８時間攪拌したところ、白色沈殿が生成した。これを濾別した後、酢酸エチルで２度洗浄し、真空乾燥機で乾燥させてアミンイミド化合物を得た。収量３．６７ｇ、収率８５％、融点１４６−１４７℃であった。
（製造例１）
温度計、攪拌機及び塩化カルシウム管を備えた５００ｍｌフラスコに、２，２−ビス〔４−（４−アミノフェノキシ）フェニル〕プロパン ４１．０５ｇ（０．１モル）及びＮ−メチル−２−ピロリドン１５０ｇを仕込み攪拌した。ジアミンの溶解後、フラスコを氷浴中で冷却しながら、１，１０−（デカメチレン）ビス（トリメリテート無水物）５２．２ｇ（０．１モル）を少量ずつ添加した。室温で３時間反応させたのち、キシレン３０ｇを加え、窒素ガスを吹き込みながら１５０℃で加熱し、水と共にキシレンを共沸除去した。その反応液を水中に注ぎ、沈殿したポリマーを濾別し、乾燥してポリイミド樹脂を得た。
【００５２】
このポリイミド樹脂５０ｇ、ｏ−クレゾールノボラック型エポキシ樹脂（日本化薬（株）製、商品名：ＥＳＣＮ−１９５）１０ｇ、フェノールノボラック樹脂（明和化成（株）製、商品名：Ｈ−１）５．３ｇ、テトラフェニルホシホニウムテトラフェニルボラート（北興化学（株）製、商品名：ＴＰＰＫ）０．２ｇを、溶剤であるＮ−メチル−２−ピロリドン２００ｇ中に加えて溶解させる。これを良く攪拌し、均一に分散させてワニスを得た。このワニスを、厚さ７５μｍの離型処理したポリエチレンテレフタレートフィルム（帝人デュポンフィルム（株）製、テイジンピューレックス：Ｓ３１）上に塗布し、１５０℃で２０分間加熱乾燥して、基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−１）を得た。
（実施例１）
温度計、攪拌機及び塩化カルシウム管を備えた５００ｍｌフラスコに、２，２−ビス〔４−（４−アミノフェノキシ）フェニル〕プロパン ４１．０５ｇ（０．１モル）及びＮ−メチル−２−ピロリドン１５０ｇを仕込み攪拌した。ジアミンの溶解後、フラスコを氷浴中で冷却しながら、１，１０−（デカメチレン）ビス（トリメリテート無水物）５２．２ｇ（０．１モル）を少量ずつ添加した。室温で３時間反応させたのち、キシレン３０ｇを加え、窒素ガスを吹き込みながら１５０℃で加熱し、水と共にキシレンを共沸除去した。その反応液を水中に注ぎ、沈殿したポリマーを濾別し、乾燥してポリイミド樹脂を得た。
【００５３】
このポリイミド樹脂５０ｇ、ｏ−クレゾールノボラック型エポキシ樹脂（日本化薬（株）製、商品名：ＥＳＣＮ−１９５）１０ｇ、フェノールノボラック樹脂（明和化成（株）製、商品名：Ｈ−１）５．３ｇ、テトラフェニルホシホニウムテトラフェニルボラート（北興化学（株）製、商品名：ＴＰＰＫ）０．２ｇ、合成例１で得られた２−ニトロベンジルカルバミン酸誘導体０．２ｇを、溶剤であるＮ−メチル−２−ピロリドン２００ｇ中に加えて溶解させる。これを良く攪拌し、均一に分散させてワニスを得た。このワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人（株）製、テイジンテトロンフィルム：Ｇ２−５０）上に塗布し、１００℃で２０分間加熱乾燥して、基材フィルムを備えた膜厚が１μｍのＢステージ状態のフィルム状粘接着層を作製した後、製造例１で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−１）をカバーフィルムとして積層し、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート１）を得た。
【００５４】
得られた接着シート１を用いて、半導体チップと厚み２５μｍのポリイミドフィルムを基材に用いた配線基板を接着シートで貼り合せた半導体装置サンプル（片面にはんだボールを形成、半導体チップと接着層、ポリイミドフィルムを基材に用いた配線基板と粘接着層が接するように貼り合せ）を作製し、耐熱性及び耐湿性を調べた。耐熱性の評価方法には、耐リフロークラック性と温度サイクル試験を適用した。耐リフロークラック性の評価は、サンプル表面の最高温度が２４０℃でこの温度を２０秒間保持するように温度設定したＩＲリフロー炉にサンプルを通し、室温で放置することにより冷却する処理を２回繰り返したサンプル中のクラックを目視と超音波顕微鏡で視察した。クラックの発生していないものを○とし、発生していたものを×とした。耐温度サイクル性は、サンプルを−５５℃雰囲気に３０分間放置し、その後１２５℃の雰囲気に３０分間放置する工程を１サイクルとして、１０００サイクル後において超音波顕微鏡を用いて剥離やクラック等の破壊が発生していないものを○、発生したものを×とした。また、耐湿性評価は、温度１２１℃、湿度１００％、２．０３×１０^５Ｐａの雰囲気（プレッシャークッカ−テスト：ＰＣＴ処理）で７２時間処理後に剥離を観察することにより行った。剥離の認められなかったものを○とし、剥離のあったものを×とした。
【００５５】
一方、接着シート１を厚さ１５０μｍのシリコンウェハ上に接着層側がシリコンウエハと接するように貼付け、接着シート付きシリコンウェハをダイシング装置上に載置した。次いで、半導体ウェハをダイシング装置上に固定して１００ｍｍ／ｓｅｃの速度で５ｍｍ×５ｍｍにダイシングした後、（株）オーク製作所製ＵＶ−３３０ ＨＱＰ−２型露光機を使用して、５００ｍＪ／ｃｍ^２の露光量で接着シートの支持体フィルム側から露光し、ピックアップ装置にてダイシングしたチップをピックアップし、ダイシング時のチップ飛び及びピックアップ性を評価した。
【００５６】
さらに、上記接着シート付きシリコンウェハに５００ｍＪ／ｃｍ^２の露光量で接着シートの支持体フィルム側から露光し、露光前後の接着シート／基材界面の接着強度を、９０°ピール強度で測定した（引張り速度 ５０ｍ／ｍｉｎ）。これらの評価結果をまとめて表１に示す。
【００５７】
【表１】

【００５８】
（実施例２）
実施例１において、カバーフィルムを製造例１で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−１）から製造例２で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−２）に変えた以外は実施例１と全く同様の操作を行い、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート２）を得た。
得られた接着シート２を実施例１と同様の条件で評価した結果を表１に示す。
（実施例３）
実施例１において、合成例１で得られた２−ニトロベンジルカルバミン酸誘導体を合成例２で得られたアミンイミド化合物に変えた以外は実施例１と全く同様の操作を行い、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート３）を得た。
得られた接着シート３を実施例１と同様の条件で評価した結果を表１に示す。
（実施例４）
実施例３において、カバーフィルムを製造例１で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−１）から製造例２で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−２）に変えた以外は実施例１と全く同様の操作を行い、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート４）を得た。
【００５９】
得られた接着シート４を実施例１と同様の条件で評価した結果を表１に示す。
（実施例５）
実施例１において、合成例１で得られた２−ニトロベンジルカルバミン酸誘導体を２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタノン−１（Ｃｉｂａ Ｓｐｅｃｉａｌｉｔｙ Ｃｈｅｍｉｃａｌｓ社製、商品名：イルガキュア３６９）に変えた以外は実施例１と全く同様の操作を行い、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート５）を得た。
【００６０】
得られた接着シート５を実施例１と同様の条件で評価した結果を表１に示す。
（実施例６）
実施例５において、カバーフィルムを製造例１で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−１）から製造例２で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−２）に変えた以外は実施例１と全く同様の操作を行い、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート６）を得た。
【００６１】
得られた接着シート６を実施例１と同様の条件で評価した結果を表１に示す。
（比較例１）
実施例１において、合成例１で得られた２−ニトロベンジルカルバミン酸誘導体を除いた以外は実施例１と全く同様の操作を行い、接着シート（接着層と粘接着層を併せた厚みが５１μｍ）（接着シート７）を得た。
【００６２】
得られた接着シート７を実施例１と同様の条件で評価した結果を表１に示す。
（比較例２）
温度計、攪拌機及び塩化カルシウム管を備えた５００ｍｌフラスコに、２，２−ビス〔４−（４−アミノフェノキシ）フェニル〕プロパン ４１．０５ｇ（０．１モル）及びＮ−メチル−２−ピロリドン１５０ｇを仕込み攪拌した。ジアミンの溶解後、フラスコを氷浴中で冷却しながら、１，１０−（デカメチレン）ビス（トリメリテート無水物）５２．２ｇ（０．１モル）を少量ずつ添加した。室温で３時間反応させたのち、キシレン３０ｇを加え、窒素ガスを吹き込みながら１５０℃で加熱し、水と共にキシレンを共沸除去した。その反応液を水中に注ぎ、沈殿したポリマーを濾別し、乾燥してポリイミド樹脂を得た。
【００６３】
このポリイミド樹脂５０ｇ、ｏ−クレゾールノボラック型エポキシ樹脂（日本化薬（株）製、商品名：ＥＳＣＮ−１９５）１０ｇ、フェノールノボラック樹脂（明和化成（株）製、商品名：Ｈ−１）５．３ｇ、テトラフェニルホシホニウムテトラフェニルボラート（北興化学（株）製、商品名：ＴＰＰＫ）０．２ｇを、溶剤であるＮ−メチル−２−ピロリドン２００ｇ中に加えて溶解させる。これを良く攪拌し、均一に分散させてワニスを得た。このワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人（株）製、テイジンテトロンフィルム：Ｇ２−５０）上に塗布し、１５０℃で２０分間加熱乾燥して、接着シート（接着層の厚みが５０μｍ）（接着シート８）を得た。
【００６４】
得られた接着シート８を実施例１と同様の条件で評価した結果を表１に示す。
（比較例３）
実施例１において、カバーフィルムを製造例１で得られた基材フィルムを備えた膜厚が５０μｍのＢステージ状態のフィルム状接着層（Ｆ−１）から、厚さ７５μｍの離型処理したポリエチレンテレフタレートフィルム（帝人デュポンフィルム（株）製、テイジンピューレックス：Ｓ３１）に変えた以外は実施例１と全く同様の操作を行い、接着シート（粘接着層の厚みが１μｍ）（接着シート９）を得た。
得られた接着シート９を実施例１と同様の条件で評価した結果を表１に示す。
【００６５】
表１から、本発明の接着シートは耐熱性および耐湿性に優れ、ダイシング時のチップ飛びも無く、ピックアップ性も良好である。さらに、露光前後の接着強度差が大きいため、作業条件の許容度が大きいため、作業条件の許容度が大きく、作業性に優れるものである。
【００６６】
【発明の効果】
本発明の接着シートは、ダイシング工程ではダイシングテープとして、半導体素子と支持部材の接合工程では接続信頼性に優れる接着剤として使用することができ、また、半導体搭載用支持部材に熱膨張係数の差が大きい半導体素子を実装する場合に必要な耐熱性、耐湿性を有し、かつ作業性に優れるものである。また、本発明の接着シートを使用した半導体装置の製造方法は、製造工程を簡略化でき、しかも製造した半導体装置は、半導体搭載用支持部材に熱膨張係数の差が大きい半導体素子を実装する場合に必要な耐熱性、耐湿性および作業性を兼ね備えるものである。
【００６７】
【図面の簡単な説明】
【図１】 本発明に係る接着シートの基材フィルムを備えた粘接着層の一例の断面図である。
【図２】 本発明に係る接着シートの基材フィルムを備えた接着層の一例の断面図である。
【図３】 本発明の接着シートの一例の断面図である。
【図４】 本発明に係る接着シートに半導体ウエハを貼着した状態を示す。
【図５】 本発明に係る接着シートを半導体ウエハのダイシング工程に用いた場合の説明図である。
【図６】 図５に示す工程の後、接着シートに、裏面から放射線を照射した状態を示す。
【図７】 図６に示す工程の後、半導体素子をピックアップする工程を示す。
【図８】 ピックアップされた半導体素子と粘接着層を示す。
【図９】 半導体素子を半導体素子搭載用支持部材に熱圧着した状態を示す。
【符号の説明】
１…基材フィルム
２…粘接着層
３…接着層
４…基材フィルム
５…吸引コレット
６…半導体素子搭載用支持部材
Ａ…半導体ウエハ
Ａ１、Ａ２、Ａ３…半導体素子
Ｂ…放射線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an adhesive sheet, a semiconductor device using the adhesive sheet, and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, a silver paste has been mainly used for joining a semiconductor element and a semiconductor element mounting support member. However, with the recent miniaturization and high performance of semiconductor devices, the supporting members used are also required to be small and fine. In response to these requirements, silver paste has various problems such as occurrence of defects during wire bonding due to protrusion and inclination of semiconductor elements, difficulty in controlling the thickness of the adhesive layer, and generation of voids in the adhesive layer. was there. In order to solve these problems, a film-like adhesive has been used in recent years. The film-like adhesive is used in an individual piece attaching method or a wafer back surface attaching method.
[0003]
In the piece pasting method, a reel-like adhesive film is cut into pieces by cutting or punching, and then adhered to a support member. The semiconductor element separated by the dicing process is joined to the support member with the adhesive film to produce the support element with the semiconductor element, and then the semiconductor element is completed through the wire bonding process, the sealing process, and the like. However, the individual sticking method requires a dedicated assembling apparatus that cuts out the adhesive film and adheres it to the support member, and there is a problem that the assembling cost becomes higher than the method using silver paste.
[0004]
On the other hand, in the wafer back surface attaching method, an adhesive film is attached to a semiconductor wafer and attached to a dicing tape, and then separated into individual pieces by a dicing process. The separated semiconductor element with an adhesive is bonded to a support member, and the semiconductor device is completed through subsequent processes such as heating, curing, and wire bonding. The wafer back surface pasting method joins a semiconductor element with an adhesive to a support member, so it does not require an apparatus for separating an adhesive film, and an existing assembly apparatus for silver paste is used as it is or a heating plate is added. Since it can be used by improving a part of the apparatus such as the above, it has been attracting attention as a method that can keep the assembly cost relatively low in the assembling method using a film adhesive.
[0005]
The semiconductor elements are separated into individual pieces in the wafer back surface attaching method by attaching a dicing tape to the film adhesive side and then performing a dicing process. At that time, the dicing tape used is roughly classified into a pressure-sensitive type and a UV type. The pressure-sensitive tape is usually obtained by applying an adhesive to a polyvinyl chloride or polyolefin base film. When the dicing tape is cut, the dicing tape needs to have a sufficient adhesive force so that each element does not scatter due to rotation by the dicing saw. On the other hand, at the time of pick-up, it is necessary to satisfy the conflicting performance of an adhesive strength that is low enough to be picked up so that no adhesive is attached to each element and the element is not damaged. For this reason, in the case of pressure-sensitive dicing tapes, many types of adhesive sheets having various adhesive strengths suitable for the element size and processing conditions are prepared with the tolerance of adhesive strength being reduced, and switching is performed for each process. For this reason, it is necessary to stock many varieties, which complicates inventory management. Moreover, the operation | work which switches an adhesive sheet for every process was required. Recently, a dicing tape called UV type, which has a high adhesive force during dicing, is irradiated with ultraviolet rays (UV) before picking up to have a low adhesive force, and responds to conflicting demands, has been widely adopted.
[0006]
In recent years, the capacity of semiconductor devices, particularly CPUs and memories, has been increasing, and as a result, the size of semiconductor devices tends to increase. Furthermore, in products such as IC cards and memory cards, the memory used is becoming thinner. With the increase in size and thickness of these semiconductor elements, the pressure-sensitive type cannot satisfy the conflicting requirements of fixing force during dicing (high adhesive force) and peeling force during pickup (low adhesive force).
[0007]
On the other hand, in the wafer back surface pasting method using the UV type, the film pasting process up to the dicing process has to be performed twice, and there is a problem that the operation becomes complicated.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an adhesive sheet that acts as a dicing tape in a dicing process and has excellent connection reliability in a bonding process between a semiconductor element and a support member. The adhesive sheet is an adhesive sheet having heat resistance and moisture resistance required for mounting a semiconductor element having a large difference in thermal expansion coefficient on the semiconductor element mounting support member, and having excellent workability. It is another object of the present invention to provide a manufacturing method that can simplify the manufacturing process of a semiconductor device.
[0009]
[Means for Solving the Problems]
The present invention relates to the following.
1. (1) (A) polyimide resin, (B) epoxy resin and epoxy resin curing agent (C) an adhesive layer containing a compound that generates a base upon irradiation with radiation, and (2) (A) polyimide resin, (B) A radiation-polymerizable and heat-polymerizable adhesive sheet comprising an adhesive layer containing an epoxy resin and an epoxy resin curing agent, and (3) a base material.
2. (1) The adhesive layer comprises (A) 100 parts by weight of a polyimide resin, 1 to 200 parts by weight of the epoxy resin and an epoxy resin curing agent, and (C) a compound that generates a base upon irradiation with radiation 0.01 2. The adhesive sheet as described in 1 above, which contains ˜200 parts by weight.
3. 3. The adhesive sheet according to 1 or 2, wherein the (2) adhesive layer contains (A) 100 parts by weight of a polyimide resin and 1 to 200 parts by weight of the epoxy resin and an epoxy resin curing agent.
4). The (1) adhesive layer, (2) adhesive layer, and (3) substrate are laminated in the order of (3) substrate / (1) adhesive layer / (2) adhesive layer. The adhesive sheet of any one of -3.
5. 5. The adhesive sheet according to any one of 1 to 4, which controls the adhesive force between the (1) adhesive layer and (3) the substrate by irradiation with radiation.
6). Any of the above 1 to 5, wherein the ratio of the film thickness of the (1) adhesive layer and (2) adhesive layer is (1) adhesive layer / (2) adhesive layer = 0.01 to 0.5 The adhesive sheet according to claim 1.
7). The semiconductor device which adhere | attached the semiconductor element and the supporting member for semiconductor mounting using the adhesive sheet of any one of said 1-6.
8). (1) A process of attaching the adhesive sheet according to any one of 1 to 6 to a semiconductor wafer via the (2) adhesive layer;
(2) dicing the semiconductor wafer to attach an adhesive layer and an adhesive layer;
(3) After dicing, irradiating the adhesive sheet with radiation to cure the adhesive layer to form a semiconductor element, and then peeling the substrate;
(4) a step of bonding the adhesive sheet and the semiconductor element with an adhesive layer and the supporting member for mounting the semiconductor element together with the adhesive sheet;
A method of manufacturing a semiconductor device including:
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The adhesive sheet of the present invention comprises (1) (A) a polyimide resin, (B) an epoxy resin and an epoxy resin curing agent (C) an adhesive layer containing a compound that generates a base upon irradiation with radiation, and (2) (A It is a radiation-polymerizable and heat-polymerizable adhesive sheet comprising a polyimide resin, (B) an adhesive layer containing an epoxy resin and an epoxy resin curing agent, and (3) a base material.
[0011]
This adhesive sheet has a sufficient adhesive force that the semiconductor element does not scatter during dicing, and then irradiates with radiation to control the adhesive force between the adhesive layer and the substrate, thereby picking up the sheet. This satisfies the conflicting requirement of having a low adhesive strength that does not damage each element, and each process of dicing and die bonding can be completed with a single film.
[0012]
The polyimide resin of the present invention can be obtained, for example, by subjecting tetracarboxylic dianhydride and diamine to a condensation reaction by a known method. That is, in an organic solvent, tetracarboxylic dianhydride and diamine are used in an equimolar or nearly equimolar amount (the order of addition of each component is arbitrary), and the addition reaction is carried out at a reaction temperature of 80 ° C. or lower, preferably 0 to 60 ° C. As the reaction proceeds, the viscosity of the reaction solution gradually increases, and polyamic acid, which is a polyimide precursor, is generated.
[0013]
The polyamic acid can also be adjusted in molecular weight by heating at a temperature of 50 to 80 ° C. to cause depolymerization.
The polyimide resin can be obtained by dehydrating and ring-closing the reaction product (polyamic acid). The dehydration ring closure can be performed by a thermal ring closure method in which heat treatment is performed and a chemical ring closure method using a dehydrating agent.
There is no restriction | limiting in particular as tetracarboxylic dianhydride used as a raw material of a polyimide resin, For example, 1, 2- (ethylene) bis (trimellitic anhydride), 1, 3- (trimethylene) bis (trimellitate anhydride), 1,4- (tetramethylene) bis (trimellitic anhydride), 1,5- (pentamethylene) bis (trimellitic anhydride), 1,6- (hexamethylene) bis (trimellitic anhydride), 1,7- ( Heptamethylene) bis (trimellitic anhydride), 1,8- (octamethylene) bis (trimellitic anhydride), 1,9- (nonamethylene) bis (trimellitic anhydride), 1,10- (decamethylene) bis (trimellitic anhydride) Product), 1,12- (dodecamethylene) bis (trimellitate anhydride), 1,16- (hexadeca) Tylene) bis (trimellitic anhydride), 1,18- (octadecamethylene) bis (trimellitate anhydride), pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) Propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane anhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane anhydride, bis (2,3-dicarboxyphenyl) Methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 3,4,9,10-perylenetetra Rubonic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 3,4,3 ′, 4′-benzophenone tetra Carboxylic dianhydride, 2,3,2 ′, 3′-benzophenone tetracarboxylic dianhydride, 3,3,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 1,2,5,6- Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetra Carboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-teto Chloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride Thiophene-2,3,5,6-tetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,4,3 ′, 4′-biphenyltetracarboxylic acid Acid dianhydride, 2,3,2 ′, 3′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3,4-dicarboxyphenyl) methyl Phenylsilane dianhydride, bis (3,4-dicarboxyphenyl) diphenylsilane dianhydride, 1,4-bis (3,4-dicarboxyphenyldimethylsilyl) benzene dianhydride, 1,3-bis (3 , 4-Dicarboxyphenyl) -1,1,3,3-tetramethyldicyclohexane dianhydride, p-phenylenebis (trimellitic anhydride), ethylenetetracarboxylic dianhydride, 1,2,3,4- Butanetetracarboxylic dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1 , 2,5,6-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, 1 , 2,3,4-cyclobutanetetracarboxylic dianhydride, bis (exo-bicyclo [2,2,1] heptane-2,3-dicarboxylic dianhydride, bicyclo- [2,2,2] -oct -7-ene 2,3,5,6-tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2, -bis [4- (3,4-dicarboxy Phenyl) phenyl] propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,2, -bis [4- (3,4-dicarboxyphenyl) phenyl] Hexafluoropropane dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 1,4-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride) 1,3-bis (2-hydroxyhexafluoroisopropyl) benzenebis (trimellitic anhydride), 5- (2,5-dioxotetrahydrofuryl) -3 Methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride, 4,4 ′-(4,4′isopropylidenediphenoxy) bis ( Phthalic dianhydride) or the like can be used, and one or more of these can be used in combination.
[0014]
Moreover, there is no restriction | limiting in particular as diamine used as a raw material of a polyimide, For example, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4 , 4′-diaminodiphenyl ether, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethermethane, bis (4-amino-3,5-dimethylphenyl) methane, bis (4 -Amino-3,5-diisopropylphenyl) methane, 3,3'-diaminodiphenyldifluoromethane, 3,4'-diaminodiphenyldifluoromethane, 4,4'-diaminodiphenyldifluoromethane, 3,3'-diaminodiphenylsulfone 3,4'-dia Nodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 3 , 4′-diaminodiphenyl ketone, 4,4′-diaminodiphenyl ketone, 2,2-bis (3-aminophenyl) propane, 2,2 ′-(3,4′-diaminodiphenyl) propane, 2,2- Bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2- (3,4'-diaminodiphenyl) hexafluoropropane, 2,2-bis (4-amino) Phenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-a Nophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,3 ′-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 3,4 ′-(1,4-phenylene) Bis (1-methylethylidene)) bisaniline, 4,4 ′-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 2,2-bis (4- (3-aminophenoxy) phenyl) propane, 2 , 2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (3-aminophenoxy) phenyl) hexafluoropropane, 2,2-bis (4- (4-aminophenoxy) ) Phenyl) hexafluoropropane, bis (4- (3-aminoenoxy) phenyl) sulfide, bis (4- (4-aminoenoxy) phenyl) sulfur Bis (4- (3-aminoenoxy) phenyl) sulfone, bis (4- (4-aminoenoxy) phenyl) sulfone, 3,5-diaminobenzoic acid and other aromatic diamines, 1,2-diaminoethane, , 3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10 -Diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane, the following general formula (I)
[0015]
[Chemical 1]

(Where R ₁ And R ₂ Represents a divalent hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different, and R ₃ And R ₄ Are monovalent hydrocarbon groups, which may be the same or different, and m is an integer of 1 or more)
[0016]
Diaminopolysiloxane represented by the formula 1,3-bis (aminomethyl) cyclohexane, manufactured by Sun Techno Chemical Co., Ltd. Jeffamine D-230, D-400, D-2000, D-4000, ED-600, ED- Aliphatic diamines such as polyoxyalkylene diamines such as 900, ED-2001 and EDR-148 can be used, and one or more of these can also be used in combination.
[0017]
The epoxy resin used in the present invention is not particularly limited as long as it is cured and exhibits an adhesive action. For example, Epicoat 807, 815, 825, 827, 828, 834, 1001, manufactured by Yuka Shell Epoxy Co., Ltd. 1004, 1007, 1009, DER-330, 301, 361 manufactured by Dow Chemical Company, bisphenol A type epoxy resin such as YD8125, YDF8170 manufactured by Tohto Kasei Co., Ltd., Epicoat 152, 154 manufactured by Yuka Shell Epoxy Co., Ltd. Phenolic novolak type epoxy resins such as EPPN-201 manufactured by Yakuhin Co., Ltd., DEN-438 manufactured by Dow Chemical Co., Ltd. EOCN-102S, 103S, 104S, 1012, 1025, 1027 manufactured by Nippon Kayaku Co., Ltd., Tohto Kasei Co., Ltd. O-cresolno such as YDCN701,702,703,704 Rack type epoxy resin, Epon 1031S manufactured by Yuka Shell Epoxy Co., Ltd., Araldite 0163 manufactured by Ciba Specialty Chemicals Co., Ltd., Denacor EX-611, 614, 614B, 622, 512, 521, 421, 411 manufactured by Nagase Kasei Co., Ltd. 321 and other polyfunctional epoxy resins, Epiquat 604 manufactured by Yuka Shell Epoxy Co., Ltd., YH-434 manufactured by Tohto Kasei Co., Ltd., TETRAD-X, TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd., manufactured by Sumitomo Chemical Co., Ltd. An amine type epoxy resin such as ELM-120, a hetero ring-containing epoxy resin such as Araldite PT810 manufactured by Ciba Specialty Chemicals, an alicyclic epoxy resin such as ERL4234, 4299, 4221, and 4206 manufactured by UCC can be used. , Using one or more of these in combination It is also possible.
[0018]
As the curing agent for the epoxy resin, those usually used as the curing agent for the epoxy resin can be used, and two or more amines, polyamides, acid anhydrides, polysulfides, boron trifluoride, and phenolic hydroxyl groups in one molecule. Examples thereof include bisphenol A, bisphenol F, bisphenol S, phenols such as polyfunctional phenol and phenol novolac resin, bisphenol A novolac resin, naphthol novolac resin or phenol resin such as cresol novolac resin. It is preferable to use phenols because of its excellent electric corrosion resistance.
The compound that generates a base upon irradiation with radiation (C) used in the present invention is not particularly limited as long as it is a compound that generates a base upon irradiation. As the base to be generated, a strongly basic compound is preferable in terms of reactivity and curing speed. In general, a pKa value that is a logarithm of the acid dissociation constant is used as a basic index, and a base having a pKa value of 7 or more in an aqueous solution is preferable, and a base of 9 or more is more preferable.
Examples of such basicity include imidazole derivatives such as imidazole, 2,4-dimethylimidazole, 1-methylimidazole, piperazine derivatives such as piperazine, 2,5-dimethylpiperazine, piperidine, 1,2-dimethylpiperidine A piperidine derivative such as, a proline derivative, a trialkylamine derivative such as trimethylamine, triethylamine, and triethanolamine, a pyridine derivative substituted with an amino group or an alkylamino group at the 4-position, such as 4-methylaminopyridine, 4-dimethylaminopyridine, Pyrrolidine derivatives such as pyrrolidine and n-methylpyrrolidine, alicyclic amine derivatives such as triethylenediamine and 1,8-diazabiscyclo (5,4,0) undecene-1 (DBU), benzylmethylamine, benzyldimethylamine, Benzylamine derivative of Le diethylamine and the like.
[0019]
Examples of the compounds generated by irradiation with the basic compound include Journal of Photopolymer Science and Technology 12, 313-314 (1999) and Chemistry of Materials 11, 170-176 (1999). The quaternary ammonium salt derivatives described can be used. Since these produce highly basic trialkylamines by irradiation with actinic rays, they are optimal for curing epoxy resins.
Further, carbamic acid derivatives described in Journal of American Chemical Society 118, 12925 (1996), Polymer Journal 28, 795 (1996), and the like can be used.
In addition, oxime derivatives that generate primary amino groups upon irradiation with actinic rays and 2-methyl-1 (4- (methylthio) phenyl) -2-morpholinopropan-1-one, which is commercially available as a photo radical generator (Irgacure 907 manufactured by Ciba Specialty Chemicals), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (Irgacure 369 manufactured by Ciba Specialty Chemicals), hexaarylbisimidazole derivative ( Substituents such as halogens, alkoxy groups, nitro groups, and cyano groups may be substituted with phenyl groups), benzoisoxazolone derivatives, and the like.
In addition to the base generator by actinic rays, a basic compound is generated by photo-Fries rearrangement, photo-Claisen rearrangement (photo Cleisen rearrangement), Curtius rearrangement (Curtius rearrangement), and Stevens rearrangement (Stevens rearrangement), thereby curing the epoxy resin. It can be carried out.
The base generator may be used as a low molecular compound having a molecular weight of 500 or less, or a compound introduced into the main chain and side chain of a polymer. The molecular weight in this case is preferably a weight average molecular weight of 1,000 to 100,000, more preferably 5,000 to 30,000, from the viewpoints of adhesiveness and fluidity as an adhesive.
Since these compounds do not show reactivity with an epoxy resin in a state where they are not irradiated with radiation at room temperature, they have a feature of excellent storage stability at room temperature.
[0020]
The ratio of the film thicknesses of the (1) adhesive layer and (2) adhesive layer of the present invention is (1) adhesive layer / (2) adhesive layer = 0.01 to 0.5, preferably 0. 0.02-0.3, more preferably 0.03-0.2. If it is 0.01 or less, the adhesive force between the adhesive layer and the substrate tends to decrease, and if it is 0.5 or more, the cost tends to increase.
[0021]
Moreover, a hardening accelerator can also be added to the adhesive layer and adhesive layer which form the adhesive sheet of this invention. There are no particular limitations on the curing accelerator, and imidazoles, dicyandiamide derivatives, dicarboxylic acid dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazoletetraphenylborate, 1,8-diazabicyclo ( 5,4,0) undecene-7-tetraphenylborate and the like can be used. These can be used alone or in combination of two or more.
[0022]
0.1-5 weight part is preferable with respect to 100 weight part of (B) epoxy resin and epoxy hardener, and, as for the addition amount of a hardening accelerator, 0.2-3 weight part is more preferable. When the addition amount is less than 0.1 parts by weight, the curability tends to be inferior, and when it exceeds 5 parts by weight, the storage stability tends to decrease.
[0023]
A high molecular weight resin compatible with an epoxy resin can be added to the adhesive layer and the adhesive layer forming the adhesive sheet of the present invention for the purpose of improving flexibility and reflow crack resistance. Such high molecular weight resin is not particularly limited, and examples thereof include phenoxy resin, high molecular weight epoxy resin, and ultra high molecular weight epoxy resin. These may be used alone or in combination of two or more.
[0024]
The amount of the high molecular weight resin compatible with the epoxy resin is preferably 40 parts by weight or less with respect to 100 parts by weight of the epoxy resin and the epoxy resin curing agent. Within this range, the Tg of the epoxy resin layer can be secured.
[0025]
In addition, an inorganic filler is added to the adhesive layer and the adhesive layer forming the adhesive sheet of the present invention for the purpose of improving the handleability, improving the thermal conductivity, adjusting the melt viscosity and imparting thixotropic properties. You can also. The inorganic filler is not particularly limited. For example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, Examples thereof include boron nitride, crystalline silica, amorphous silica, and the like, and the shape of the filler is not particularly limited. These fillers can be used alone or in combination of two or more.
[0026]
Among these, aluminum oxide, aluminum nitride, boron nitride, crystalline silica, amorphous silica and the like are preferable for improving thermal conductivity. For the purpose of adjusting melt viscosity and imparting thixotropic properties, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, crystallinity Silica, amorphous silica and the like are preferable.
[0027]
The amount of the inorganic filler used is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the adhesive layer or the adhesive layer. If the amount is less than 1 part by weight, the effect of addition tends not to be obtained. If the amount exceeds 20 parts by weight, the storage elastic modulus of the adhesive layer or the adhesive layer increases, the adhesive property decreases, and the electrical properties due to voids remain. There is a tendency to cause problems such as decline.
[0028]
In addition, various coupling agents can be added to the adhesive layer and the adhesive layer forming the adhesive sheet of the present invention in order to improve interfacial bonding between different materials. Examples of the coupling agent include silane-based, titanium-based, and aluminum-based, and among them, a silane-based coupling agent is preferable because it is highly effective.
[0029]
The silane coupling agent is not particularly limited, and examples thereof include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- Methacryloxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldi Ethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyl Limethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltri Methoxysilane, 3-aminopropyl-tris (2-methoxy-ethoxy-ethoxy) silane, N-methyl-3-aminopropyltrimethoxysilane, triaminopropyltrimethoxysilane, 3-4,5-dihydroimidazole-1- Yl-propyltrimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyldimethoxysilane, 3 Cyanopropyltriethoxysilane, hexamethyldisilazane, N, O-bis (trimethylsilyl) acetamide, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, amyltrichlorosilane , Octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltri (methacryloyloxyethoxy) silane, methyltri (glycidyloxy) silane, N-β (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane , Octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimeth Sisilane, γ-chloropropylmethyldiethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate, methylsilyl triisocyanate, vinylsilyl triisocyanate, phenylsilyl triisocyanate, tetraisocyanate silane, ethoxysilane isocyanate, etc. can be used alone. Alternatively, two or more types can be used in combination.
[0030]
Examples of the titanium-based coupling agent include isopropyl trioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl Phenyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tris (n-aminoethyl) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2,2-diallyl) Oxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, dic Ruphenyloxyacetate titanate, bis (dioctylpyrophosphate) oxyacetate titanate, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium Octylene glycolate, Titanium lactate ammonium salt, Titanium lactate, Titanium lactate ethyl ester, Titanium chili ethanolamate, Polyhydroxy titanium stearate, Tetramethyl orthotitanate, Tetraethyl orthotitanate, Tetarapropyl orthotitanate, Tetraisobutyl orthotitanate, Stearyl Titanate, cresyl titanate monomer, cresyl titanate , Diisopropoxy-bis (2,4-pentadionate) titanium (IV), diisopropyl-bis-triethanolamino titanate, octylene glycol titanate, tetra-n-butoxytitanium polymer, tri-n-butoxytitanium mono A stearate polymer, tri-n-butoxy titanium monostearate, etc. can be used, and it can be used individually or in combination of 2 or more types.
[0031]
Examples of the aluminum coupling agent include ethyl acetoacetate aluminum diisopropylate, aluminum toys (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetyl acetate bis (ethyl acetoacetate), aluminum tris (acetylacetate). Nate), aluminum = monoisopropoxy monooroxyethyl acetoacetate, aluminum-di-n-butoxide monoethyl acetoacetate, aluminum chelate compounds such as aluminum-di-iso-propoxide-monoethyl acetoacetate, aluminum isopropylate, Mono-sec-butoxyaluminum diisopropylate, aluminum-sec-butyrate, aluminum It can be used such as aluminum alcoholate such Muechireto, alone or in combination of two or more kinds may be used.
[0032]
It is preferable that the usage-amount of the said coupling agent shall be 0.01-10 weight part with respect to 100 weight part of (A) polyimide resin and an epoxy resin hardening | curing agent from the surface of the effect, heat resistance, and cost.
[0033]
An ion scavenger may be further added to the adhesive layer and adhesive layer forming the adhesive sheet of the present invention in order to adsorb ionic impurities and improve insulation reliability during moisture absorption. Such an ion scavenger is not particularly limited, for example, triazine thiol compound, bisphenol-based reducing agent, etc., a compound known as a copper damage preventing agent for preventing copper ionization and dissolution, zirconium-based And inorganic ion adsorbents such as antimony bismuth-based magnesium aluminum compounds.
[0034]
The amount of the ion scavenger used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the (A) polyimide resin from the viewpoint of the effect of addition, heat resistance, cost, and the like.
[0035]
The adhesive sheet of the present invention can be obtained by dissolving or dispersing the composition forming the adhesive sheet in a solvent to form a varnish, applying the composition on a base film and heating to remove the solvent.
[0036]
The base material used for the adhesive sheet of the present invention is not particularly limited, and examples thereof include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. It is done.
[0037]
The adhesive sheet of the present invention irradiates the adhesive sheet with radiation after completion of the dicing process, polymerizes and cures the radiation-polymerizable adhesive sheet, and reduces the adhesive force between the adhesive sheet and the substrate interface, thereby picking up the semiconductor element. It is what makes it possible.
[0038]
The adhesive sheet of the present invention can be obtained by dissolving or dispersing the composition forming the adhesive sheet in a solvent to form a varnish, applying the composition on a base film and heating to remove the solvent.
[0039]
Further, the solvent for varnishing is not particularly limited, but considering the volatility during film production, for example, methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, It is preferable to use a solvent having a relatively low boiling point such as methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, and xylene. In addition, for the purpose of improving the coating properties, for example, a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, cyclohexanone can be used. These solvents can be used alone or in combination of two or more.
[0040]
For the production of the varnish when the inorganic filler is added, it is preferable to use a raking machine, a three-roll, a ball mill, a bead mill or the like in consideration of the dispersibility of the inorganic filler, or a combination thereof. You can also Moreover, after mixing an inorganic filler and a low molecular weight raw material beforehand, the mixing time can also be shortened by mix | blending a high molecular weight raw material. Further, after the varnish is formed, the bubbles in the varnish can be removed by vacuum degassing or the like.
[0041]
As a method for applying the varnish to the base film, a known method can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. .
[0042]
Although there is no restriction | limiting in particular in the thickness of an adhesive sheet, 5-250 micrometers is preferable for both an adhesive layer and a base material layer. If the thickness is less than 5 μm, the stress relaxation effect tends to be poor. If the thickness is more than 250 μm, it is not economical and the demand for miniaturization of the semiconductor device cannot be met.
[0043]
Moreover, in order to obtain a desired sheet thickness, the adhesive sheet of the present invention may be further provided so that one or more adhesive layers or adhesive layers are sandwiched between the semiconductor wafer and the adhesive layer. In this case, as the adhesive layer provided as desired, in addition to those prepared by the above method, those prepared by a conventionally known method can be used. As the adhesive layer provided as desired, a commercially available adhesive sheet such as a polyimide-based, silicon oligomer-based, rubber-epoxy-based, or epoxy-based adhesive can be used. However, it is necessary to consider a bonding condition that does not cause peeling between the adhesive or the adhesives or between the adhesive and the adhesive based on a conventionally known technique.
[0044]
When the adhesive sheet having the structure as described above is irradiated with radiation, the adhesive strength at the interface between the base material and the adhesive sheet is greatly reduced after the radiation irradiation, and the base film of the adhesive sheet is easily retained with the adhesive layer held on the semiconductor element. Can be picked up from.
[0045]
The adhesive layer of the adhesive sheet of the present invention may be combined with heating for the purpose of accelerating the curing reaction simultaneously with radiation irradiation or after radiation irradiation, in addition to the method of reducing the adhesive strength of the substrate only by radiation irradiation. By using heating together, the adhesive strength can be reduced at a lower temperature and in a shorter time. Although heating temperature will not be restrict | limited especially if it is below the decomposition point of an adhesive bond layer, The temperature of 50-170 degreeC is preferable.
[0046]
Next, the usage method of the adhesive sheet which concerns on this invention is demonstrated. An adhesive and an adhesive are separately applied on the base films 1 and 4, and an adhesive layer (FIG. 1) provided with the base film and an adhesive layer (FIG. 2) provided with the base film are provided. After the production, the above two layers can be laminated to obtain an adhesive sheet (FIG. 3), or the adhesive layer varnish is applied on the adhesive layer (FIG. 1) provided with the base film. It is also possible to use a method of applying an adhesive layer varnish on an adhesive layer (FIG. 2) provided with a base film. After producing the adhesive layer (FIG. 1) provided with the said base film and the adhesive layer (FIG. 2) provided with the base film, the said 2 layers are laminated | stacked and the method of obtaining an adhesive sheet (FIG. 3) is obtained. When selected, the base film 4 is peeled off in the step of attaching the semiconductor wafer thereafter, so that the base film 4 / the adhesive film / the adhesive film / the adhesive film / the adhesive film interface 4 / It is important to select a base film so that the adhesiveness at the adhesive interface is minimized. As shown in FIG. 4, after the semiconductor wafer A to be diced is pasted on the upper surface of the adhesive layer, dicing, cleaning, and drying steps are performed on the semiconductor wafer A in the pasted state as shown in FIG. Is added. At this time, since the semiconductor wafer A is sufficiently adhered and held on the adhesive sheet by the adhesive layer 3, the semiconductor wafer A does not fall off during each of the above steps.
[0047]
Next, as shown in FIG. 6, radiation B is applied to the adhesive layer 2 of the adhesive sheet, and a part or most of the radiation-polymerizable adhesive sheet is polymerized and cured. In this case, heating may be used in combination with the purpose of accelerating the curing reaction simultaneously with irradiation or after irradiation. By using heating together, the adhesive strength can be reduced at a lower temperature and in a shorter time. Although heating temperature will not be restrict | limited especially if it is below the thermal decomposition temperature of an adhesive bond layer, The temperature of 50-170 degreeC is preferable.
[0048]
Irradiation to the adhesive sheet is performed from the surface of the base film 1 on which the adhesive layer 2 is not provided. Therefore, as described above, when UV is used as the radiation, the base film 1 needs to be light transmissive, but when EB is used as the radiation, the base film 2 is not necessarily light transmissive. There is no need.
[0049]
After the irradiation, the semiconductor elements A1, A2, A3 to be picked up are picked up by, for example, a suction collet 4. At this time, the semiconductor elements A1, A2, and A3 to be picked up can be pushed up from the lower surface of the base film 1 by, for example, a needle bar. Since the adhesive force between the semiconductor element A1 and the adhesive layer 3 is larger than the adhesive force between the adhesive layer 2 and the base film 1, when the semiconductor element A1 is picked up, the adhesive layer 2 The adhesive layer 3 is peeled off in a state of being attached to the lower surface of the semiconductor element A1 (see FIG. 8). Next, the semiconductor element is placed on the semiconductor element mounting support member 5 via the adhesive layer 2 and the adhesive layer 3 and heated. The adhesive layer 2 and the adhesive layer 3 exhibit an adhesive force by heating, and the adhesion between the semiconductor element and the semiconductor element mounting support member is completed (see FIG. 9).
[0050]
【Example】
Hereinafter, the present invention will be described in detail by way of examples. The present invention is not limited to these.
(Synthesis Example 1)
30 g of 2-nitrobenzyl alcohol was stirred and dissolved in 300 g of tetrahydrofuran at room temperature using a magnetic stirrer. A solution consisting of 24.5 g of 4,4′-diphenylmethane diisocyanate and 100 g of tetrahydrofuran was added dropwise to this solution over 30 minutes, followed by stirring at room temperature for 1 hour. Thereafter, a Liebig cooling tube was set and reacted for 2 hours while heating to 60 ° C. in an oil bath. After the reaction, the reaction solution was cooled to room temperature and concentrated using a rotary evaporator until the reaction solution was halved.
[0051]
When the obtained concentrate was added to 1000 parts by weight of n-hexane, a white precipitate was obtained. The precipitate was suction filtered and dried overnight at 60 ° C. under vacuum to obtain the desired 2-nitrobenzylcarbamic acid derivative. The yield was 49.5 g (yield 91%).
(Synthesis Example 2)
Add p-nitrobenzoic acid methyl ester (2.00 g, 11 mmol), N, N-dimethylhydrazine (0.66 g, 11 mmol), phenylglycidyl ether (1.66 g, 11 mmol) to tert-butanol (15.0 g). After stirring at 50 ° C. for 10 hours and further stirring at room temperature (25 ° C.) for 48 hours, a white precipitate was formed. This was filtered off, washed twice with ethyl acetate, and dried in a vacuum dryer to obtain an amine imide compound. The yield was 3.67 g, the yield was 85%, and the melting point was 146-147 ° C.
(Production Example 1)
In a 500 ml flask equipped with a thermometer, stirrer and calcium chloride tube, 41.05 g (0.1 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 150 g of N-methyl-2-pyrrolidone Were stirred. After dissolution of the diamine, 52.2 g (0.1 mol) of 1,10- (decamethylene) bis (trimellitate anhydride) was added in small portions while the flask was cooled in an ice bath. After reacting at room temperature for 3 hours, 30 g of xylene was added, and the mixture was heated at 150 ° C. while blowing nitrogen gas to azeotropically remove xylene together with water. The reaction solution was poured into water, and the precipitated polymer was filtered off and dried to obtain a polyimide resin.
[0052]
4. 50 g of this polyimide resin, 10 g of o-cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: ESCN-195), phenol novolac resin (manufactured by Meiwa Kasei Co., Ltd., trade name: H-1) 3 g, 0.2 g of tetraphenylphosphinium tetraphenylborate (manufactured by Hokuko Chemical Co., Ltd., trade name: TPPK) is added to 200 g of N-methyl-2-pyrrolidone as a solvent and dissolved therein. This was well stirred and dispersed uniformly to obtain a varnish. This varnish is applied on a 75 μm thick polyethylene terephthalate film (Teijin DuPont Films, Teijin Purex: S31) that has been subjected to a release treatment, and is heated and dried at 150 ° C. for 20 minutes to provide a base film. A film-like adhesive layer (F-1) in a B stage state having a thickness of 50 μm was obtained.
(Example 1)
In a 500 ml flask equipped with a thermometer, stirrer and calcium chloride tube, 41.05 g (0.1 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 150 g of N-methyl-2-pyrrolidone Were stirred. After dissolution of the diamine, 52.2 g (0.1 mol) of 1,10- (decamethylene) bis (trimellitate anhydride) was added in small portions while the flask was cooled in an ice bath. After reacting at room temperature for 3 hours, 30 g of xylene was added, and the mixture was heated at 150 ° C. while blowing nitrogen gas to azeotropically remove xylene together with water. The reaction solution was poured into water, and the precipitated polymer was filtered off and dried to obtain a polyimide resin.
[0053]
4. 50 g of this polyimide resin, 10 g of o-cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: ESCN-195), phenol novolac resin (manufactured by Meiwa Kasei Co., Ltd., trade name: H-1) 3 g, 0.2 g of tetraphenylphosphinium tetraphenylborate (manufactured by Hokuko Chemical Co., Ltd., trade name: TPPK), 0.2 g of the 2-nitrobenzylcarbamic acid derivative obtained in Synthesis Example 1 are used as solvents. Add to 200 g of N-methyl-2-pyrrolidone and dissolve. This was well stirred and dispersed uniformly to obtain a varnish. This varnish was applied onto a polyethylene terephthalate having a thickness of 50 μm (manufactured by Teijin Ltd., Teijin Tetron film: G2-50) and dried by heating at 100 ° C. for 20 minutes. The film thickness provided with the base film was 1 μm. After the film-like adhesive layer in the B-stage state was prepared, the film-like adhesive layer (F-1) in the B-stage state having the thickness of 50 μm provided with the base film obtained in Production Example 1 was covered As a result, an adhesive sheet (51 μm in total thickness of the adhesive layer and the adhesive layer) (adhesive sheet 1) was obtained.
[0054]
Using the obtained adhesive sheet 1, a semiconductor device sample in which a semiconductor chip and a wiring board using a polyimide film having a thickness of 25 μm as a base material are bonded together with an adhesive sheet (forming solder balls on one side, semiconductor chip and adhesive layer, A wiring board using a polyimide film as a base material and an adhesive layer were bonded so that the adhesive layer was in contact, and the heat resistance and moisture resistance were examined. As a heat resistance evaluation method, reflow crack resistance and a temperature cycle test were applied. Evaluation of reflow cracking resistance was repeated twice by passing the sample through an IR reflow furnace set at a maximum temperature of 240 ° C and holding the temperature for 20 seconds, and allowing it to cool at room temperature. The cracks in the samples were observed visually and with an ultrasonic microscope. The thing which did not generate | occur | produce the crack was set to (circle), and the thing which had generate | occur | produced was set to x. The temperature cycle resistance is that the sample is left in an atmosphere at -55 ° C for 30 minutes and then left in an atmosphere at 125 ° C for 30 minutes. After 1000 cycles, the sample is destroyed by peeling or cracking using an ultrasonic microscope. The case where no occurred was marked with ◯, and the case where it occurred was marked with ×. In addition, the humidity resistance evaluation was performed at a temperature of 121 ° C., a humidity of 100%, and 2.03 × 10. ⁵ This was carried out by observing peeling after treatment for 72 hours in an atmosphere of Pa (pressure cooker test: PCT treatment). The case where peeling was not recognized was marked with ◯, and the case where peeling was observed was marked with ×.
[0055]
On the other hand, the adhesive sheet 1 was stuck on a silicon wafer having a thickness of 150 μm so that the adhesive layer side was in contact with the silicon wafer, and the silicon wafer with the adhesive sheet was placed on a dicing apparatus. Next, the semiconductor wafer was fixed on a dicing apparatus and diced to 5 mm × 5 mm at a speed of 100 mm / sec, and then 500 mJ / cm using a UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd. ² The chip was exposed from the support film side of the adhesive sheet with the exposure amount and diced with a pickup device, and the chip skipping and pick-up properties during dicing were evaluated.
[0056]
Furthermore, 500 mJ / cm on the silicon wafer with the adhesive sheet. ² Was exposed from the support film side of the adhesive sheet, and the adhesive strength at the interface between the adhesive sheet and the substrate before and after the exposure was measured at 90 ° peel strength (tensile speed: 50 m / min). These evaluation results are summarized in Table 1.
[0057]
[Table 1]

[0058]
(Example 2)
In Example 1, a base film obtained in Production Example 2 from a B-stage film-like adhesive layer (F-1) having a film thickness of 50 μm provided with the base film obtained in Production Example 1 as a cover film The same operation as in Example 1 was performed except that the film-like adhesive layer (F-2) in a B-stage state having a film thickness of 50 μm was prepared, and an adhesive sheet (the adhesive layer and the adhesive layer were combined) The thickness was 51 μm) (adhesive sheet 2).
Table 1 shows the results of evaluating the obtained adhesive sheet 2 under the same conditions as in Example 1.
(Example 3)
In Example 1, except that the 2-nitrobenzylcarbamic acid derivative obtained in Synthesis Example 1 was changed to the amine imide compound obtained in Synthesis Example 2, the same operation as in Example 1 was performed, and an adhesive sheet (adhesive layer) And the adhesive layer were 51 μm in thickness) (adhesive sheet 3).
Table 1 shows the results of evaluating the obtained adhesive sheet 3 under the same conditions as in Example 1.
Example 4
In Example 3, the base film obtained in Production Example 2 from the B-stage film-like adhesive layer (F-1) having a film thickness of 50 μm provided with the base film obtained in Production Example 1 as the cover film The same operation as in Example 1 was performed except that the film-like adhesive layer (F-2) in a B-stage state having a film thickness of 50 μm was prepared, and an adhesive sheet (the adhesive layer and the adhesive layer were combined) The thickness was 51 μm) (adhesive sheet 4).
[0059]
Table 1 shows the results of evaluating the obtained adhesive sheet 4 under the same conditions as in Example 1.
(Example 5)
In Example 1, the 2-nitrobenzylcarbamic acid derivative obtained in Synthesis Example 1 was converted to 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (Ciba Specialty Chemicals, product) Except that the name was changed to Irgacure 369), the same operation as in Example 1 was performed to obtain an adhesive sheet (the thickness of the adhesive layer and the adhesive layer combined was 51 μm) (adhesive sheet 5).
[0060]
Table 1 shows the results of evaluating the obtained adhesive sheet 5 under the same conditions as in Example 1.
(Example 6)
In Example 5, the base film obtained in Production Example 2 from the B-stage film-like adhesive layer (F-1) having a film thickness of 50 μm provided with the base film obtained in Production Example 1 as the cover film The same operation as in Example 1 was performed except that the film-like adhesive layer (F-2) in a B-stage state having a film thickness of 50 μm was prepared, and an adhesive sheet (the adhesive layer and the adhesive layer were combined) The thickness was 51 μm) (adhesive sheet 6).
[0061]
Table 1 shows the results of evaluating the obtained adhesive sheet 6 under the same conditions as in Example 1.
(Comparative Example 1)
In Example 1, except for the 2-nitrobenzylcarbamic acid derivative obtained in Synthesis Example 1, the same operation as in Example 1 was performed, and the adhesive sheet (the thickness of the adhesive layer and the adhesive layer was combined) 51 μm) (adhesive sheet 7) was obtained.
[0062]
Table 1 shows the results of evaluating the obtained adhesive sheet 7 under the same conditions as in Example 1.
(Comparative Example 2)
In a 500 ml flask equipped with a thermometer, stirrer and calcium chloride tube, 41.05 g (0.1 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 150 g of N-methyl-2-pyrrolidone Were stirred. After dissolution of the diamine, 52.2 g (0.1 mol) of 1,10- (decamethylene) bis (trimellitate anhydride) was added in small portions while the flask was cooled in an ice bath. After reacting at room temperature for 3 hours, 30 g of xylene was added and heated at 150 ° C. while blowing nitrogen gas, and xylene was removed azeotropically with water. The reaction solution was poured into water, and the precipitated polymer was filtered off and dried to obtain a polyimide resin.
[0063]
4. 50 g of this polyimide resin, 10 g of o-cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: ESCN-195), phenol novolac resin (manufactured by Meiwa Kasei Co., Ltd., trade name: H-1) 3 g, 0.2 g of tetraphenylphosphinium tetraphenylborate (manufactured by Hokuko Chemical Co., Ltd., trade name: TPPK) is added to 200 g of N-methyl-2-pyrrolidone as a solvent and dissolved therein. This was well stirred and dispersed uniformly to obtain a varnish. This varnish was applied onto a polyethylene terephthalate having a thickness of 50 μm (manufactured by Teijin Ltd., Teijin Tetron film: G2-50) and dried by heating at 150 ° C. for 20 minutes to form an adhesive sheet (adhesive layer thickness of 50 μm). (Adhesive sheet 8) was obtained.
[0064]
Table 1 shows the results of evaluating the obtained adhesive sheet 8 under the same conditions as in Example 1.
(Comparative Example 3)
In Example 1, a polyethylene film having a release film thickness of 75 μm from a B-stage film-like adhesive layer (F-1) having a film thickness of 50 μm provided with the base film obtained in Production Example 1 as a cover film. Except for changing to a terephthalate film (manufactured by Teijin DuPont Films, Teijin Purex: S31), the same operation as in Example 1 was performed, and an adhesive sheet (adhesive layer thickness 1 μm) (adhesive sheet 9) Got.
Table 1 shows the results of evaluating the obtained adhesive sheet 9 under the same conditions as in Example 1.
[0065]
From Table 1, the adhesive sheet of the present invention has excellent heat resistance and moisture resistance, no chip skipping during dicing, and good pick-up properties. Furthermore, since the difference in adhesive strength before and after exposure is large, the tolerance of work conditions is large, so the tolerance of work conditions is large and the workability is excellent.
[0066]
【The invention's effect】
The adhesive sheet of the present invention can be used as a dicing tape in the dicing process, and as an adhesive having excellent connection reliability in the joining process of the semiconductor element and the support member. It has heat resistance and moisture resistance necessary for mounting a large semiconductor element and is excellent in workability. Moreover, the manufacturing method of the semiconductor device using the adhesive sheet of the present invention can simplify the manufacturing process, and the manufactured semiconductor device mounts a semiconductor element having a large difference in thermal expansion coefficient on a semiconductor mounting support member. It has the heat resistance, moisture resistance and workability necessary for the above.
[0067]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an example of an adhesive layer provided with a base film of an adhesive sheet according to the present invention.
FIG. 2 is a cross-sectional view of an example of an adhesive layer provided with a base film of an adhesive sheet according to the present invention.
FIG. 3 is a cross-sectional view of an example of the adhesive sheet of the present invention.
FIG. 4 shows a state in which a semiconductor wafer is attached to the adhesive sheet according to the present invention.
FIG. 5 is an explanatory diagram when the adhesive sheet according to the present invention is used in a dicing process of a semiconductor wafer.
6 shows a state where the adhesive sheet is irradiated with radiation from the back surface after the step shown in FIG. 5;
FIG. 7 shows a step of picking up a semiconductor element after the step shown in FIG. 6;
FIG. 8 shows a picked-up semiconductor element and an adhesive layer.
FIG. 9 shows a state in which a semiconductor element is thermocompression bonded to a semiconductor element mounting support member.
[Explanation of symbols]
1 ... Base film
2 ... Adhesive layer
3. Adhesive layer
4 ... Base film
5 ... Suction collet
6 ... Supporting member for mounting a semiconductor element
A ... Semiconductor wafer
A1, A2, A3 ... Semiconductor element
B ... Radiation

Claims (8)

(1) (A) polyimide resin, (B) epoxy resin and epoxy resin curing agent (C) an adhesive layer containing a compound that generates a base upon irradiation, and (2) (A) polyimide resin, (B) A radiation-polymerizable and heat-polymerizable adhesive sheet comprising an adhesive layer containing an epoxy resin and an epoxy resin curing agent, and (3) a base material. (1) The adhesive layer comprises (A) 100 parts by weight of a polyimide resin, 1 to 200 parts by weight of the epoxy resin and epoxy resin curing agent, and (C) a compound that generates a base upon irradiation with radiation 0.01 The adhesive sheet according to claim 1, which comprises ˜200 parts by weight. The adhesive sheet according to claim 1 or 2, wherein the (2) adhesive layer contains (A) 100 parts by weight of a polyimide resin and 1 to 200 parts by weight of the epoxy resin and an epoxy resin curing agent. The (1) adhesive layer, (2) adhesive layer, and (3) substrate are laminated in the order of (3) substrate / (1) adhesive layer / (2) adhesive layer. The adhesive sheet of any one of 1-3. The adhesive sheet of any one of Claims 1-4 which controls the adhesive force between the said (1) adhesive agent layer and (3) base material by irradiation of a radiation. The ratio of the film thickness of the (1) adhesive layer and (2) adhesive layer is (1) adhesive layer / (2) adhesive layer = 0.01-0.5. The adhesive sheet of any one of Claims. A semiconductor device in which a semiconductor element and a semiconductor mounting support member are bonded using the adhesive sheet according to claim 1. (1) A process of attaching the adhesive sheet according to any one of claims 1 to 6 to a semiconductor wafer via the (2) adhesive layer;
(2) dicing the semiconductor wafer to attach an adhesive layer and an adhesive layer;
(3) After dicing, irradiating the adhesive sheet with radiation to cure the adhesive layer to form a semiconductor element, and then peeling the substrate;
(4) a step of bonding the adhesive sheet and the semiconductor element with an adhesive layer and the supporting member for mounting the semiconductor element together with the adhesive sheet;
A method of manufacturing a semiconductor device including:

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