JPWO2003018703A1 - Adhesive sheet, semiconductor device and method of manufacturing the same - Google Patents

Abstract

An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation, wherein the adhesive layer Is an adhesive sheet containing the following components. (A) a thermoplastic resin, (b) a thermopolymerizable component, and (c) a compound capable of generating a base upon irradiation with radiation The adhesive sheet of the present invention has a sufficient adhesive force so that the semiconductor element does not scatter at the time of dicing. By irradiating radiation to control the adhesive force between the adhesive layer and the base material, it satisfies the conflicting requirement of having a low adhesive force so as not to damage each element at the time of pickup. It is.

Description

（式中Ｒ^１、Ｒ^２、Ｒ^３は独立に水素、炭素数１〜８のアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルキリデン基、炭素数４〜８のシクロアルキル基、炭素数４〜８のシクロアルケニル基、炭素数１〜６のフェノキシアルキル基、フェニル基、電子供与性基及び／又は電子吸引性基が置換したフェニル基、ベンジル基、電子供与性基及び／又は電子吸引性基が置換したベンジル基等が挙げられる。炭素数１〜８のアルキル基としては、直鎖上のアルキル基の他に、イソプロピル基、イソブチル基、ｔ−ブチル基等も含む。これらの置換基の中で、合成の簡便性、アミンイミドの溶解性等の点から、炭素数１〜８のアルキル基、炭素数６〜８のシクロアルキル基、炭素数１〜６のフェノキシアルキル基が好ましい。また、Ｒ^４は独立に炭素数１〜５のアルキル基、水酸基、炭素数４〜８のシクロアルキル基、炭素数１〜５のアルコキシ基、フェニル基を表す。）
で表される化合物が挙げられる。
上記一般式（ＩＩ）中のＡｒ^１は一般式（ＩＶ）〜（ＸＶＩ）で表される芳香族基であり、また、前記一般式（２）中のＡｒ^２は、次式（ＸＶＩＩ）〜（ＸＸＶ）で示される芳香族基であることが好ましい。Ａｒ^１と同様に熱的な安定性、吸収波長の点から、Ｒ^２９〜Ｒ^３６の置換基としては、電子吸引性基である炭素数１〜６のカルボニル基、シアノ基、ニトロ基が好ましい。
前記アミンイミド化合物の合成は、公知の方法を用いることができる。例えば、Ｅｎｃｙｃｌｏｐｅｄｉａ ｏｆ Ｐｏｌｙｍｅｒ Ｓｃｉｅｎｃｅ ａｎｄ Ｅｎｇｉｎｅｅｒｉｎｇ、Ｊｏｈｎ Ｗｉｌｅｙ ＆ Ｓｏｎｓ Ｌｔｄ．（１９８５年）、第１巻、ｐ７４０に記載されているように、対応するカルボン酸エステルとハロゲン化ヒドラジン及びナトリウムアルコキサイドとの反応やカルボン酸エステルとヒドラジン及びエポキシ化合物との反応から得ることができる。合成の簡便性、安全性を考慮すると、対応するカルボン酸エステルとヒドラジン及びエポキシ化合物からの合成法が特に好ましい。合成温度、合成時間に関しては、使用する出発物質の分解等が無ければ特に制限を受けないが、一般的には０〜１００℃の温度で３０分〜７日間攪拌することによって目的のアミンイミド化合物を得ることができる。
（イミダゾリウム塩）
また、本発明に使用する放射線照射によって塩基を発生する化合物としては、前記化合物以外にも、イミダゾリウム塩を使用することができる。イミダゾリウム塩としては、例えば、一般式（１）又は（２）で示されるイミダゾリウム塩化合物が挙げられる。

（式中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４は独立に水素、炭素数１〜８のアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルキリデン基、炭素数４〜８のシクロアルキル基、炭素数４〜８のシクロアルケニル基、炭素数１〜６のフェノキシアルキル基、炭素数１〜６のフェニルアルキル基、炭素数１〜６のシアノアルキル基、炭素数１〜６のヒドロキシアルキル基、フェニル基、電子供与性基及び／又は電子吸引性基が置換したフェニル基、ベンジル基、電子供与性基及び／又は電子吸引性基が置換したベンジル基、ニトロ基、シアノ基、メルカプト基、チオメチル基、フッ素、臭素、塩素、ヨウ素を示す。
また、Ａｒ_１は次式（Ｉ）〜（ＸＩＶ）で表される芳香族基であり、

（式中、Ｒ^５〜Ｒ^２８は独立に、水素、炭素数１〜８のアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルキルチオ基、炭素数１〜８のアルキリデン基、炭素数４〜８のシクロアルキル基、炭素数４〜８のシクロアルケニル基、アミノ基、炭素数１〜６のアルキルアミノ基、炭素数１〜３のジアルキルアミノ基、モルフォリノ基、メルカプト基、水酸基、炭素数１〜６のヒドロキシアルキル基、フッ素、塩素、臭素等のハロゲン、炭素数１〜６のエステル基、炭素数１〜６のカルボニル基、アルデヒド基、シアノ基、トリフルオロメチル基、シアノ基、ニトロ基、フェニル基、電子供与性基及び／又は電子吸引性基が置換したフェニル基、電子供与性基及び／又は電子吸引性基が置換したベンジル基である。また式中、Ｔ、Ｕ、Ｖ、Ｗ、Ｙ、Ｚは独立に、炭素、窒素、酸素、硫黄原子のいずれかを示す。）
またＡｒ_２は、次式（ＸＶ）〜（ＸＸＩＩＩ）で示される芳香族基であり、

（式中、Ｒ_２９〜Ｒ_３６は独立に、水素、炭素数１〜８のアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルキルチオ基、炭素数１〜８のアルキリデン基、炭素数４〜８のシクロアルキル基、炭素数４〜８のシクロアルケニル基、アミノ基、炭素数１〜６のアルキルアミノ基、炭素数１〜３のジアルキルアミノ基、モルフォリノ基、メルカプト基、水酸基、炭素数１〜６のヒドロキシアルキル基、フッ素、塩素、臭素等のハロゲン、炭素数１〜６のエステル基、炭素数１〜６のカルボニル基、アルデヒド基、シアノ基、トリフルオロメチル基、シアノ基、ニトロ基、フェニル基、電子供与性基及び／又は電子吸引性基が置換したフェニル基、電子供与性基及び／又は電子吸引性基が置換したベンジル基である。また式中、Ａ、Ｂ、Ｄ、Ｅは、独立に炭素、窒素、酸素、硫黄原子のいずれかであり、それらは炭素、窒素、炭素数１〜６のアルキル基、酸素、硫黄と結合しても良い。）
また、Ｘ⁻は、炭素数１〜６のジアルキルジチオカルバミド酸、次式（ＸＸＩＶ）で表されるほう酸である。

（式中、Ｒ_３７〜Ｒ_４０は、独立に水素、フッ素、炭素数１〜６のアルキル基、フェニル基、フッ素が少なくとも１つ以上置換したフルオロフェニル基、イミダゾール基である。））
本発明に使用する光照射によって塩基を発生する上記一般式（１）又は（２）で示されるイミダゾリウム塩化合物の合成は、公知の方法を用いることができるが、合成の簡便性、安全性を考慮すると、下式（ＸＸＶＩＩ）に示すように、ハロゲン化アルキルケトン誘導体とイミダゾール誘導体とで、イミダゾリウム・ハロゲン塩を合成した後、アニオン交換反応によって、イミダゾリウム塩を合成する方法が好ましい。

合成温度、合成時間に関しては、使用する出発物質の分解等が無ければ特に制限を受けないが、一般的には０〜１００℃の温度で３０分〜７日間攪拌することによって目的のイミダゾリウム塩化合物を得ることができる。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。
これまで例示した放射線照射によって塩基を発生する化合物の使用量としては、エポキシ樹脂１００重量部に対して、０．０１〜２００重量部が好ましく、０．０２〜１５０重量部がより好ましい。使用量が０．０１重量部未満であるとピックアップ時の粘着力が低下しにくい傾向があり、使用する化合物によっては、耐熱性が低下することもある。また、使用量が２００重量部を超えると、接着剤フィルムとしての特性・保存安定性・フィルムの物性が悪化する傾向がある。
（一重項増感剤、三重項増感剤）
また、本発明の接着シートを形成する粘接着剤層には、照射光の高吸収化、高感度化を目的に、増感剤を添加することもできる。使用する増感剤としては、硬化性組成物に悪影響を及ぼさない限り、公知の一重項増感剤、三重項増感剤を用いることができる。
上記増感剤としては、例えば、ナフタレン、アントラセン、ピレン等の芳香族化合物誘導体、カルバゾール誘導体、ベンゾフェノン誘導体、ベンゾイン誘導体、チオキサントン誘導体、クマリン誘導体などが好適に用いられる。
前記増感剤の使用量は、増感剤の吸収波長及びモル吸光係数を参考にする必要があるが、（ｃ）放射線照射によって塩基を発生する１重量部に対して０．０１〜１０重量部が好ましく、０．１〜５重量部がより好ましく、０．１〜２部が特に好ましい。増感剤が０．０１重量部以下になると光吸収の効率が低くなり、１０重量部を超えると光透過率が悪くなる傾向がある。
本発明で用いる増感剤は、硬化性組成物に悪影響を及ぼさない限り、公知の一重項増感剤、三重項増感剤を用いることができる。例えば、ナフタレン、アントラセン、ピレン等の芳香族化合物誘導体、カルバゾール誘導体、芳香族カルボニル化合物、ベンゾフェノン誘導体、ベンゾイン誘導体、チオキサントン誘導体、クマリン誘導体等が好適に用いられる。特にこの中でも、一重項増感剤としては、ナフタレン誘導体、アントラセン誘導体、カルバゾール誘導体、三重項増感剤としては、チオキサントン誘導体、ベンゾフェノン誘導体、ベンゾイン誘導体が最も好ましい。例えば、１−メチルナフタレン、２−メチルナフタレン、１−フルオロナフタレン、１−クロロナフタレン、２−クロロナフタレン、１−ブロモナフタレン、２−ブロモナフタレン、１−ヨードナフタレン、２−ヨードナフタレン、１−ナフトール、２−ナフトール、下記一般式（Ｉ）〜（ＸＸＩＩＩ）で示される化合物、

（式中、Ｒ^５〜Ｒ^２８は独立に、水素、炭素数１〜８のアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルキルチオ基、炭素数１〜８のアルキリデン基、炭素数４〜８のシクロアルキル基、炭素数４〜８のシクロアルケニル基、アミノ基、炭素数１〜６のアルキルアミノ基、炭素数１〜３のジアルキルアミノ基、モルフォリノ基、メルカプト基、水酸基、炭素数１〜６のヒドロキシアルキル基、フッ素、塩素、臭素等のハロゲン、炭素数１〜６のエステル基、炭素数１〜６のカルボニル基、アルデヒド基、シアノ基、トリフルオロメチル基、シアノ基、ニトロ基、ベンゾイル基、フェニル基、電子供与性基及び／又は電子吸引性基が置換したフェニル基、電子供与性基及び／又は電子吸引性基が置換したベンジル基である。また式中、Ｔ、Ｕ、Ｖ、Ｗ、Ｙ、Ｚは独立に、炭素、窒素、酸素、硫黄原子のいずれかを示す。）

（式中、Ｒ^２９〜Ｒ^３６は独立に、水素、炭素数１〜８のアルキル基、炭素数１〜８のアルコキシ基、炭素数１〜８のアルキルチオ基、炭素数１〜８のアルキリデン基、炭素数４〜８のシクロアルキル基、炭素数４〜８のシクロアルケニル基、アミノ基、炭素数１〜６のアルキルアミノ基、炭素数１〜３のジアルキルアミノ基、モルフォリノ基、メルカプト基、水酸基、炭素数１〜６のヒドロキシアルキル基、フッ素、塩素、臭素等のハロゲン、炭素数１〜６のエステル基、炭素数１〜６のカルボニル基、アルデヒド基、シアノ基、トリフルオロメチル基、シアノ基、ニトロ基、フェニル基、電子供与性基及び／又は電子吸引性基が置換したフェニル基、電子供与性基及び／又は電子吸引性基が置換したベンジル基である。式中Ａ、Ｂ、Ｄ、Ｅは独立に、炭素、窒素、酸素、硫黄原子のいずれかであり、それらは炭素、窒素、炭素数１〜６のアルキル基、酸素、硫黄と結合しても良い。）等が挙げられる。 このほかにも、１−メトキシナフタレン、２−メトキシナフタレン、１，４−ジシアノナフタレン、アントラセン、１，２−ベンズアントラセン、９，１０−ジクロロアントラセン、９，１０−ジブロモアントラセン、９，１０−ジフェニルアントラセン、９−シアノアントラセン、９，１０−ジシアノアントラセン、２，６，９，１０−テトラシアノアントラセン、カルバゾール、９−メチルカルバゾール、９−フェニルカルバゾール、９−プロペ−２−イニル−９Ｈ−カルバゾール、９−プロピル−９Ｈ−カルバゾール、９−ビニルカルバゾール、９Ｈ−カルバゾール−９−エタノール、９−メチル−３−ニトロ−９Ｈ−カルバゾール、９−メチル−３，６−ジニトロ−９Ｈ−カルバゾール、９−オクタノイルカルバゾール、９−カルバゾールメタノール、９−カルバゾールプロピオン酸、９−カルバゾールプロピオニトリル、９−デシル−３，６−ジニトロ−９Ｈ−カルバゾール、９−エチル−３，６−ジニトロ−９Ｈ−カルバゾール、９−エチル−３−ニトロカルバゾール、９−エチルカルバゾール、９−イソプロピルカルバゾール、９−（エトキシカルボニルメチル）カルバゾール、９−（モルホリノメチル）カルバゾール、９−アセチルカルバゾール、９−アリルカルバゾール、９−ベンジル−９Ｈ−カルバゾール、９−カルバゾール酢酸、９−（２−ニトロフェニル）カルバゾール、９−（４−メトキシフェニル）カルバゾール、９−（１−エトキシ−２−メチル−プロピル）−９Ｈ−カルバゾール、３−ニトロカルバゾール、４−ヒドロキシカルバゾール、３，６−ジニトロ−９Ｈ−カルバゾール、３，６−ジフェニル−９Ｈ−カルバゾール、２−ヒドロキシカルバゾール、３，６−ジアセチル−９−エチルカルバゾール、ベンゾフェノン、４−フェニルベンゾフェノン、４，４‘−ビス（ジメトキシ）ベンゾフェノン、４，４‘−ビス（ジメチルアミノ）ベンゾフェノン、４，４‘−ビス（ジエチルアミノ）ベンゾフェノン、２−ベンゾイル安息香酸メチルエステル、２−メチルベンゾフェノン、３−メチルベンゾフェノン、４−メチルベンゾフェノン、３，３‘−ジメチル−４−メトキシベンゾフェノン、２，４，６−トリメチルベンゾフェノン、［４−（４−メチルフェニルチオ）フェニル］−フェニルメタノン、キサントン、チオキサントン、２−クロロチオキサントン、４−クロロチオキサントン、２−イソプロピルチオキサントン、４−イソプロピルチオキサントン、２，４−ジメチルチオキサントン、２，４−ジエチルチオキサントン、１−クロロ−４−プロポキシチオキサントン、ベンゾイン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル、ベンゾインｎ−プロピルエーテル、ベンゾインｎ−ブチルエーテル、ベンゾインイソブチルエーテル、２，２−ジメトキシ−１，２−ジフェニルエタノン、２，２−ジエトキシ−１，２−ジフェニルエタノンが挙げられる。これらは、単独で用いるほかに、複数を組み合わせて用いても良い。
これまで述べてきたような、（ｃ）光照射により塩基を発生する化合物は、室温で放射線を照射しない状態ではエポキシ樹脂等の熱重合性化合物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。
（熱可塑性樹脂）
本発明の接着シートを形成する粘接着剤層にはフィルム形成性向上の目的で、熱可塑性樹脂を含ませることができる。
前記熱可塑性樹脂は、熱可塑性を有する樹脂、または少なくとも、未硬化状態において熱可塑性を有し、加熱後に架橋構造を形成する樹脂であれば特に制限はないが、Ｔｇ（ガラス転移温度）が−５０〜１０℃で重量平均分子量が１０００００〜１００００００であるもの、又は、Ｔｇが１０〜１００℃でかつ重量平均分子量が５０００〜２０００００であることが好ましい。
前者の熱可塑性樹脂としては、官能性モノマーを含む重合体を使用することが好ましく、後者の熱可塑性樹脂としては、例えば、ポリイミド樹脂、ポリアミド樹脂、ポリエーテルイミド樹脂、ポリアミドイミド樹脂、ポリエステル樹脂、ポリエステルイミド樹脂、フェノキシ樹脂、ポリスルホン樹脂、ポリエーテルスルホン樹脂、ポリフェニレンサルファイド樹脂、ポリエーテルケトン樹脂等が挙げられ、中でもポリイミド樹脂が好ましい。
上記官能性モノマーを含む重合体における官能基としては、例えば、グリシジル基、アクリロイル基、メタクリロイル基、水酸基、カルボキシル基、イソシアヌレート基、アミノ基、アミド基等が挙げられ、中でもグリジシル基が好ましい。より具体的には、グリシジルアクリレート又はグリシジルメタクリレートなどの官能性モノマーを含有するグリシジル基含有（メタ）アクリル共重合体などが好ましく、さらにエポキシ樹脂等の熱硬化性樹脂と非相溶であることが好ましい。
（官能性モノマーを含む重量平均分子量が１０万以上である高分子量成分）
上記官能性モノマーを含む重量平均分子量が１０万以上である高分子量成分としては、例えば、グリシジルアクリレート又はグリシジルメタクリレート等の官能性モノマーを含有し、かつ重量平均分子量が１０万以上であるグリシジル基含有（メタ）アクリル共重合体等が挙げられ、そのうちでもエポキシ樹脂と非相溶であるものが好ましい。
上記グリシジル基含有（メタ）アクリル共重合体としては、例えば、（メタ）アクリルエステル共重合体、アクリルゴム等を使用することができ、アクリルゴムがより好ましい。アクリルゴムは、アクリル酸エステルを主成分とし、主として、ブチルアクリレートとアクリロニトリル等の共重合体や、エチルアクリレートとアクリロニトリル等の共重合体等からなるゴムである。
上記官能性モノマーとは官能記を有するモノマーのことをいい、このようなものとしては、グリシジルアクリレート又はグリシジルメタクリレート等を使用することが好ましい。このような重量平均分子量が１０万以上であるグリシジル基含有（メタ）アクリル共重合体としては、例えば、ナガセケムテックス（株）製ＨＴＲ−８６０Ｐ−３等が挙げられる。
上記グリシジルアクリレート又はグリシジルメタクリレート等のエポキシ樹脂含有反復単位の量は、０．５〜６．０重量％が好ましく、０．５〜５．０重量％がより好ましく、０．８〜５．０重量％が特に好ましい。グリシジル基含有反復単位の量がこの範囲にあると、接着力が確保できるとともに、ゲル化を防止することができる。
グリシジルアクリレート、グリシジルメタクリレート以外の上記官能性モノマーとしては、例えば、エチル（メタ）アクリレート、ブチル（メタ）アクリレート等が挙げられ、これらは、単独で又は２種類以上を組み合わせて使用することもできる。なお、本発明において、エチル（メタ）アクリレートとは、エチルアクリレートとエチルメタクリレートの両方を示す。官能性モノマーを組み合わせて使用する場合の混合比率は、グリシジル基含有（メタ）アクリル共重合体のＴｇを考慮して決定し、Ｔｇは−１０℃以上であることが好ましい。Ｔｇが−１０℃以上であると、Ｂステージ状態での粘接着剤層のタック性が適当であり、取り扱い性に問題を生じないからである。
上記モノマーを重合させて、官能性モノマーを含む重量平均分子量が１０万以上である高分子量成分を製造する場合、その重合方法としては特に制限はなく、例えば、パール重合、溶液重合等の方法を使用することができる。
本発明において、官能性モノマーを含む高分子量成分の重量平均分子量は、１０万以上であるが、３０万〜３００万であることが好ましく、５０万〜２００万であることがより好ましい。重量平均分子量がこの範囲にあると、シート状又はフィルム状としたときの強度、可とう性、及びタック性が適当であり、また、フロー性が適当のため配線の回路充填性が確保できる。なお、本発明において、重量平均分子量とは、後に評価方法の欄で説明するようにゲルパーミュエーションクロマトグラフィーで測定し、標準ポリスチレン検量線を用いて換算した値を示す。
また、官能性モノマーを含む重量平均分子量が１０万以上である高分子量成分の使用量は、熱重合性成分１００重量部に対して、１０〜４００重量部が好ましい。この範囲にあると、貯蔵弾性率及び成型時のフロー性抑制が確保でき、また高温での取り扱い性も充分に得られる。高分子量成分の使用量は、１５〜３５０重量部がより好ましく、２０〜３００重量部が特に好ましい。
（ポリイミド樹脂）
上記熱可塑性樹脂のうち、好ましいものの一つであるポリイミド樹脂は、テトラカルボン酸二無水物とジアミンを公知の方法で縮合反応させて得ることができる。すなわち、有機溶媒中で、テトラカルボン酸二無水物とジアミンを等モル又はほぼ等モル用い（各成分の添加順序は任意）、反応温度８０℃以下、好ましくは０〜６０℃で付加反応させる。反応が進行するにつれ反応液の粘度が徐々に上昇し、ポリイミドの前駆体であるポリアミド酸が生成する。
上記ポリアミド酸は、５０〜８０℃の温度で加熱して解重合させることによって、その分子量を調整することもできる。
ポリイミド樹脂は、上記反応物（ポリアミド酸）を脱水閉環させて得ることができる。脱水閉環は、加熱処理する熱閉環法と、脱水剤を使用する化学閉環法で行うことができる。
ポリイミド樹脂の原料として用いられるテトラカルボン酸二無水物としては特に制限は無く、例えば、１，２−（エチレン）ビス（トリメリテート無水物）、１，３−（トリメチレン）ビス（トリメリテート無水物）、１，４−（テトラメチレン）ビス（トリメリテート無水物）、１，５−（ペンタメチレン）ビス（トリメリテート無水物）、１，６−（ヘキサメチレン）ビス（トリメリテート無水物）、１，７−（ヘプタメチレン）ビス（トリメリテート無水物）、１，８−（オクタメチレン）ビス（トリメリテート無水物）、１，９−（ノナメチレン）ビス（トリメリテート無水物）、１，１０−（デカメチレン）ビス（トリメリテート無水物）、１，１２−（ドデカメチレン）ビス（トリメリテート無水物）、１，１６−（ヘキサデカメチレン）ビス（トリメリテート無水物）、１，１８−（オクタデカメチレン）ビス（トリメリテート無水物）、ピロメリット酸二無水物、３，３’、４，４’−ビフェニルテトラカルボン酸二無水物、２，２’、３，３’−ビフェニルテトラカルボン酸二無水物、２，２−ビス（３，４−ジカルボキシフェニル）プロパン二無水物、２，２−ビス（２，３−ジカルボキシフェニル）プロパン二無水物、１，１−ビス（２，３−ジカルボキシフェニル）エタン二無水物、１，１−ビス（３，４−ジカルボキシフェニル）エタン二無水物、ビス（２，３−ジカルボキシフェニル）メタン二無水物、ビス（３，４−ジカルボキシフェニル）メタン二無水物、ビス（３，４−ジカルボキシフェニル）スルホン二無水物、３，４，９，１０−ペリレンテトラカルボン酸二無水物、ビス（３，４−ジカルボキシフェニル）エーテル二無水物、ベンゼン−１，２，３，４−テトラカルボン酸二無水物、３，４，３’，４’−ベンゾフェノンテトラカルボン酸二無水物、２，３，２’，３’−ベンゾフェノンテトラカルボン酸二無水物、３，３，３’，４’−ベンゾフェノンテトラカルボン酸二無水物、１，２，５，６−ナフタレンテトラカルボン酸二無水物、１，４，５，８−ナフタレンテトラカルボン酸二無水物、２，３，６，７−ナフタレンテトラカルボン酸二無水物、１，２，４，５−ナフタレンテトラカルボン酸二無水物、２，６−ジクロロナフタレン−１，４，５，８−テトラカルボン酸二無水物、２，７−ジクロロナフタレン−１，４，５，８−テトラカルボン酸二無水物、２，３，６，７−テトラクロロナフタレン−１，４，５，８−テトラカルボン酸二無水物、フェナンスレン−１，８，９，１０−テトラカルボン酸二無水物、ピラジン−２，３，５，６−テトラカルボン酸二無水物、チオフェン−２，３，５，６−テトラカルボン酸二無水物、２，３，３’，４’−ビフェニルテトラカルボン酸二無水物、３，４，３’，４’−ビフェニルテトラカルボン酸二無水物、２，３，２’，３’−ビフェニルテトラカルボン酸二無水物、ビス（３，４−ジカルボキシフェニル）ジメチルシラン二無水物、ビス（３，４−ジカルボキシフェニル）メチルフェニルシラン二無水物、ビス（３，４−ジカルボキシフェニル）ジフェニルシラン二無水物、１，４−ビス（３，４−ジカルボキシフェニルジメチルシリル）ベンゼン二無水物、１，３−ビス（３，４−ジカルボキシフェニル）−１，１，３，３−テトラメチルジシクロヘキサン二無水物、ｐ−フェニレンビス（トリメリテート無水物）、エチレンテトラカルボン酸二無水物、１，２，３，４−ブタンテトラカルボン酸二無水物、デカヒドロナフタレン−１，４，５，８−テトラカルボン酸二無水物、４，８−ジメチル−１，２，３，５，６，７−ヘキサヒドロナフタレン−１，２，５，６−テトラカルボン酸二無水物、シクロペンタン−１，２，３，４−テトラカルボン酸二無水物、ピロリジン−２，３，４，５−テトラカルボン酸二無水物、１，２，３，４−シクロブタンテトラカルボン酸二無水物、ビス（エキソ−ビシクロ〔２，２，１〕ヘプタン−２，３−ジカルボン酸二無水物、ビシクロ−〔２，２，２〕−オクト−７−エン−２，３，５，６−テトラカルボン酸二無水物、２，２−ビス（３，４−ジカルボキシフェニル）ヘキサフルオロプロパン二無水物、２，２、−ビス〔４−（３，４−ジカルボキシフェニル）フェニル〕ヘキサフルオロプロパン二無水物、４，４’−ビス（３，４−ジカルボキシフェノキシ）ジフェニルスルフィド二無水物、１，４−ビス（２−ヒドロキシヘキサフルオロイソプロピル）ベンゼンビス（トリメリット酸無水物）、１，３−ビス（２−ヒドロキシヘキサフルオロイソプロピル）ベンゼンビス（トリメリット酸無水物）、５−（２，５−ジオキソテトラヒドロフリル）−３−メチル−３−シクロヘキセン−１，２−ジカルボン酸二無水物、テトラヒドロフラン−２，３，４，５−テトラカルボン酸二無水物等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。
また、ポリイミドの原料として用いられるジアミンとしては特に制限は無く、例えば、ｏ−フェニレンジアミン、ｍ−フェニレンジアミン、ｐ−フェニレンジアミン、３，３’−ジアミノジフェニルエーテル、３，４’−ジアミノジフェニルエーテル、４，４’−ジアミノジフェニルエーテル、３，３’−ジアミノジフェニルメタン、３，４’−ジアミノジフェニルメタン、４，４’−ジアミノジフェニルエーテメタン、ビス（４−アミノ−３，５−ジメチルフェニル）メタン、ビス（４−アミノ−３，５−ジイソプロピルフェニル）メタン、３，３’−ジアミノジフェニルジフルオロメタン、３，４’−ジアミノジフェニルジフルオロメタン、４，４’−ジアミノジフェニルジフルオロメタン、３，３’−ジアミノジフェニルスルフォン、３，４’−ジアミノジフェニルスルフォン、４，４’−ジアミノジフェニルスルフォン、３，３’−ジアミノジフェニルスルフィド、３，４’−ジアミノジフェニルスルフィド、４，４’−ジアミノジフェニルスルフィド、３，３’−ジアミノジフェニルケトン、３，４’−ジアミノジフェニルケトン、４，４’−ジアミノジフェニルケトン、２，２−ビス（３−アミノフェニル）プロパン、２，２’−（３，４’−ジアミノジフェニル）プロパン、２，２−ビス（４−アミノフェニル）プロパン、２，２−ビス（３−アミノフェニル）ヘキサフルオロプロパン、２，２−（３，４，−ジアミノジフェニル）ヘキサフルオロプロパン、２，２−ビス（４−アミノフェニル）ヘキサフルオロプロパン、１，３−ビス（３−アミノフェノキシ）ベンゼン、１，４−ビス（３−アミノフェノキシ）ベンゼン、１，４−ビス（４−アミノフェノキシ）ベンゼン、３，３’−（１，４−フェニレンビス（１−メチルエチリデン））ビスアニリン、３，４’−（１，４−フェニレンビス（１−メチルエチリデン））ビスアニリン、４，４’−（１，４−フェニレンビス（１−メチルエチリデン））ビスアニリン、２，２−ビス（４−（３−アミノフェノキシ）フェニル）プロパン、２，２−ビス（４−（４−アミノフェノキシ）フェニル）プロパン、２，２−ビス（４−（３−アミノフェノキシ）フェニル）ヘキサフルオロプロパン、２，２−ビス（４−（４−アミノフェノキシ）フェニル）ヘキサフルオロプロパン、ビス（４−（３−アミノエノキシ）フェニル）スルフィド、ビス（４−（４−アミノエノキシ）フェニル）スルフィド、ビス（４−（３−アミノエノキシ）フェニル）スルフォン、ビス（４−（４−アミノエノキシ）フェニル）スルフォン、３，５−ジアミノ安息香酸等の芳香族ジアミン、１，２−ジアミノエタン、１，３−ジアミノプロパン、１，４−ジアミノブタン、１，５−ジアミノペンタン、１，６−ジアミノヘキサン、１，７−ジアミノヘプタン、１，８−ジアミノオクタン、１，９−ジアミノノナン、１，１０−ジアミノデカン、１，１１−ジアミノウンデカン、１，１２−ジアミノドデカン、１，２−ジアミノシクロヘキサン、下記一般式（３）

（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）
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種又は２種以上を併用することもできる。前記ポリイミド樹脂のＴｇとしては、０〜２００℃であることが好ましく、重量平均分子量としては、１万〜２０万であることが好ましい。
（その他の成分）
これまで述べた成分を有することで、特性に優れた接着シートを得ることができるが、さらに特性を最適化するため又は適用される半導体パッケージの構造等に応じて、次に示すようなその他の成分を用いることができる。
（放射線重合性成分）
本発明の接着シートに用いる粘接着剤層を構成する成分として放射線照射による重合の感度を向上させる目的で放射線重合性成分を含ませることができる。放射線重合性成分としては、特に制限は無く、例えば、アクリル酸メチル、メタクリル酸メチル、アクリル酸エチル、メタクリル酸エチル、アクリル酸ブチル、メタクリル酸ブチル、アクリル酸２−エチルヘキシル、メタクリル酸２−エチルヘキシル、ペンテニルアクリレート、テトラヒドロフルフリルアクリレート、テトラヒドロフルフリルメタクリレート、ジエチレングリコールジアクリレート、トリエチレングリコールジアクリレート、テトラエチレングリコールジアクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジメタクリレート、テトラエチレングリコールジメタクリレート、トリメチロールプロパンジアクリレート、トリメチロールプロパントリアクリレート、トリメチロールプロパンジメタクリレート、トリメチロールプロパントリメタクリレート、１，４−ブタンジオールジアクリレート、１，６−ヘキサンジオールジアクリレート、１，４−ブタンジオールジメタクリレート、１，６−ヘキサンジオールジメタクリレート、ペンタエリスリトールトリアクリレート、ペンタエリスリトールテトラアクリレート、ペンタエリスリトールトリメタクリレート、ペンタエリスリトールテトラメタクリレート、ジペンタエリスリトールヘキサアクリレート、ジペンタエリスリトールヘキサメタクリレート、スチレン、ジビニルベンゼン、４−ビニルトルエン、４−ビニルピリジン、Ｎ−ビニルピロリドン、２−ヒドロキシエチルアクリレート、２−ヒドロキシエチルメタクリレート、１，３−アクリロイルオキシ−２−ヒドロキシプロパン、１，２−メタクリロイルオキシ−２−ヒドロキシプロパン、メチレンビスアクリルアミド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ−メチロールアクリルアミド、トリス（β−ヒドロキシエチル）イソシアヌレートのトリアクリレート、下記一般式（４）

（式中、Ｒ_１及びＲ_２は水素又はメチル基を示し、ｑ及びｒは１以上の整数である）
で表される化合物、ジオール類及び、一般式（５）

（式中、ｎは０〜１の整数であり、Ｒ_３は炭素原子数が１〜３０の２価あるいは３価の有機性基である）
で表されるイソシアネート化合物及び、一般式（６）

（式中、Ｒ_４は水素又はメチル基であり、Ｒ_５はエチレン基あるいはプロピレン基である）
で表される化合物からなるウレタンアクリレート又はウレタンメタクリレート、一般式（７）

（式中、Ｒ_６は炭素原子数が２〜３０の２価の有機基を示す）
で表されるジアミン及び、一般式（８）

（式中、ｎは０〜１の整数であり、Ｒ_７は炭素原子数が１〜３０の２価あるいは３価の有機性基である）
で表されるイソシアネート化合物及び、一般式（９）

（式中、ｎは０〜１の整数である）
で表される化合物からなる尿素メタクリレート、官能基を含むビニル共重合体に少なくとも１個のエチレン性不飽和基と、オキシラン環、イソシアネート基、水酸基、カルボキシル基等の１個の官能基を有する化合物を付加反応させて得られる側鎖にエチレン性不飽和基を有する放射線重合性共重合等などを使用することもできる。これらの放射線重合化合物は、単独で又は２種類以上を組み合わせて使用することができる。
また、放射線照射によって上記エポキシ樹脂の硬化を促進する塩基を発生するような化合物を使用して放射線重合性とすることもできる。
（硬化促進剤）
また、本発明の接着シートを形成する粘接着剤層には、さらに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ポレート、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。これらは単独で又は２種類以上を組み合わせて使用することができる。
硬化促進剤の添加量は、熱重合性成分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。添加量がこの範囲にあると、硬化性と保存安定性を両立することができる。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。
また、本発明の接着シートを形成する粘接着剤層には、放射線重合性化合物の重合を開始するための、活性光の照射によって遊離ラジカルを生成する光重合開始剤を添加することもできる。このような光重合開始剤としては、例えば、ベンゾフェノン、Ｎ，Ｎ′−テトラメチル−４，４′−ジアミノベンゾフェノン（ミヒラーケトン）、Ｎ，Ｎ′−テトラエチル−４，４′−ジアミノベンゾフェノン、４−メトキシ−４′−ジメチルアミノベンゾフェノン、２−ベンジル−２−ジメチルアミノ−１−（４−モルホリノフェニル）−ブタノン−１、２，２−ジメトキシ−１，２−ジフェニルエタン−１−オン、１−ヒドロキシ−シクロヘキシル−フェニル−ケトン、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ノン−１，２，４−ジエチルチオキサントン、２−エチルアントラキノン、フェナントレンキノン等の芳香族ケトン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインフェニルエーテル等のベンゾインエーテル、メチルベンゾイン、エチルベンゾイン等のベンゾイン、ベンジルジメチルケタール等のベンジル誘導体、２−（ｏ−クロロフェニル）−４，５−ジフェニルイミダゾール二量体、２−（ｏ−クロロフェニル）−４，５−ジ（ｍ−メトキシフェニル）イミダゾール二量体、２−（ｏ−フルオロフェニル）−４，５−フェニルイミダゾール二量体、２−（ｏ−メトキシフェニル）−４，５−ジフェニルイミダゾール二量体、２−（ｐ−メトキシフェニル）−４，５−ジフェニルイミダゾール二量体、２，４−ジ（ｐ−メトキシフェニル）−５−フェニルイミダゾール二量体、２−（２，４−ジメトキシフェニル）−４，５−ジフェニルイミダゾール二量体等の２，４，５−トリアリールイミダゾール二量体、９−フェニルアクリジン、１，７−ビス（９，９′−アクリジニル）ヘプタン等のアクリジン誘導体などを使用することができ、これらは単独で又は２種類以上を組み合わせて使用することができる。上記光重合開始剤の使用量として特に制限はないが、放射線重合性化合物１００重量部に対して、０．０１〜３０重量部が好ましい。
また、本発明の接着シートを形成する粘接着剤層には、その取り扱い性向上、熱伝導性向上、溶融粘度の調整及びチキソトロピック性付与などを目的として、フィラーを添加することもできる。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。
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。
フィラーの使用量は、粘接着剤層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、接着剤層の貯蔵弾性率の上昇、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。
また、本発明の接着シートを形成する粘接着剤層には、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。
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。
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。
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。
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、粘接着剤層１００重量部に対して、０．００１〜１０重量部とするのが好ましい。
本発明の接着シートを形成する粘接着剤層には、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。
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、粘接着剤層１００重量部に対して、０．０１〜１０重量部が好ましい。
（貯蔵弾性率）
本発明の接着シートを形成する粘接着剤層は、加熱硬化した段階で、貯蔵弾性率が２５℃で１０〜２０００ＭＰａであり、２６０℃で３〜５０ＭＰａであることが好ましい。２５℃での貯蔵弾性率は、２０〜１９００ＭＰａがより好ましく、５０〜１８００ＭＰａが特に好ましい。また、２６０℃での貯蔵弾性率は、５〜５０ＭＰａがより好ましく、７〜５０ＭＰａが特に好ましい。貯蔵弾性率がこの範囲にあると、半導体素子と支持部材との熱膨張係数の差によって発生する熱応力を緩和させる効果が保たれ、剥離やクラックの発生を抑制できるとともに、接着剤の取り扱い性に優れ、リフロークラックの発生を抑制できる。上記加熱硬化の条件は粘接着剤層の組成によっても異なるが、通常１２０〜２４０℃、５〜６００分の範囲である。
この貯蔵弾性率は、例えば、動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を使用し、接着剤硬化物に引張荷重をかけて、周波数１０Ｈｚ、昇温速度５〜１０℃／ｍｉｎの条件で−５０℃から３００℃まで測定する、温度依存性測定モードによって測定できる。
＜パラメータの説明＞
本発明の接着シートは、ダイシング時には半導体素子が飛散しない十分な粘着力を有し、その後放射線を照射して前記粘接着剤層と基材層との間の接着力を制御することによりピックアップ時には各素子を傷つけることがないような低い粘着力を有するという相反する要求を満足するものである。そのため、ダイシング及びダイボンドの各工程を一枚のフィルムで完了することができるという作用・効果を有するものである。また、本発明の接着シートは、半導体素子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要求される耐熱性及び耐湿性を有するものである。
このような作用・効果を有する本発明の接着シートのさらなる最適化を図るべく特性や化学的観点から検討した結果、本発明者らは、以下に説明するように所定のパラメータを特定することで、接着シートに使用する原料にかかわらず、より好適に前記作用効果が得られることを見出した。
即ち、本発明は所定のパラメータを有する接着シートに関する。
まず、本発明の理解を容易にする目的で本発明におけるパラメータの意義について説明する。尚、本発明におけるフロー量、溶融粘度及び貯蔵弾性率のそれぞれの測定対象は粘接着剤層であるものとする。
本発明においてフロー量とは、流動性の指標となるものであって、例えば、接着シートを１０×２０ｍｍの大きさに切断し、スライドガラス上に置き、１６０℃、０．８ＭＰａで１８秒間加圧し、初期の大きさより周辺にはみ出した長さを光学顕微鏡で測定することにより得られる値である。
本発明において接着強度とは、特に説明のない限り前記粘接着剤層と前記基材層界面の９０°ピール強度を示すものとする。この接着強度は、例えば、ダイシングすべき半導体ウェハの裏面に上記接着シートを室温又は加熱しながら圧着して貼り付けた後、基材層のみを、引張り角度：９０°、引張り速度：５０ｍｍ／ｍｉｎで引張った時のピール剥離力を測定することにより得られる値である。
本発明において溶融粘度とは、フィルム流動性の指標となるものであって、例えば平行平板プラストメータ法により測定、算出することにより得られる値である。溶融粘度は、例えば、接着シートを８枚ラミネートし、厚さ約４００μｍのフィルムを作製し、これを直径１１．３ｍｍの円形に打ち抜いたものを試料とし、１６０℃において荷重２．５ｋｇｆで５秒間加圧し、加圧前後の試料の厚みから後述する式１を用いることで算出されるものである。
本発明においてタック強度とは、粘接着剤層の粘接着性の指標となるものであって、例えば、ＲＨＥＳＣＡ社製タッキング試験機を用いて、ＪＩＳＺ０２３７−１９９１に記載の方法により引き剥がし速度１０ｍｍ／ｓ、接触荷重１００ｇｆ／ｃｍ^２、接触時間１ｓ の条件で、測定温度２５℃で測定することにより得られる値である。
本発明においてｔａｎδとは、損失弾性率／貯蔵弾性率であり、エネルギー散逸項、すなわちその温度における流動性の指標となるものであって、例えば、動的粘弾性装置を用いて、昇温速度５℃／ｍｉｎ、引張モード、周波数１０Ｈｚの条件によって測定される値である。
本発明において貯蔵弾性率とは、フィルムの硬さ（軟らかさ）の指標となるものであって、例えば、動的粘弾性装置を用いて昇温速度５℃／ｍｉｎ、引張モード、周波数１０Ｈｚの条件で測定することにより得られる値である。
以上、本発明に用いられるパラメータについて概説したが、より具体的な測定方法は後の実施例の欄で適宜詳しく説明する。
次に、本発明の好ましい態様をいくつか挙げながらパラメータの臨界値の意義について説明する。尚、本発明が以下の態様に限定されないことはいうまでもない。
（第１の態様）
本発明の一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ１）放射線照射前の前記粘接着剤層と前記基材層界面の接着強度が２００ｍＮ／ｃｍ以上であり、かつ、（Ｂ１）放射線照射前の１６０℃におけるフロー量が１００〜１００００μｍである接着シートが挙げられる。
（第２の態様）
また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ１）放射線照射前の前記粘接着剤層と前記基材層界面の接着強度が２００ｍＮ／ｃｍ以上であり、かつ、（Ｂ２）放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓである接着シートが挙げられる。
本発明の一態様としての接着シートにおいて、前記粘接着剤層のフロー量は、放射線照射前で１００〜１００００μｍであり、１００〜６０００μｍであることがより好ましく、２００〜４０００μｍであることがさらに好ましく、５００〜４０００μｍであることが最も好ましい。フロー量が１００μｍに満たないと、ダイシングすべき半導体ウェハに上記接着シートが充分に粘着しない可能性があり、１００００μｍを超えると、ハンドリング性等の作業性が低下する可能性がある。
また本発明の一態様としての接着シートにおいて、前記粘接着剤層の放射線照射前後のフロー量比（照射後フロー量／照射前フロー量）は、０．１以上であることが好ましく、０．１５以上であることがより好ましく、０．２以上であることがさらに好ましい。この値が０．１未満であると、半導体素子と支持部材との接合工程において、半導体素子が充分に接合できない可能性がある。前記フロー量比の最大値は、特に制限はないが、通常取り得る最大値は１．０である。
本発明の一態様としての接着シートにおいて、放射線照射前（ダイシング時）の前記接着強度は、ダイシング時に半導体素子が飛散しないようにできる点で、２００ｍＮ／ｃｍ以上であることが好ましく、２５０ｍＮ／ｃｍ以上であることがより好ましく、３００ｍＮ／ｃｍ以上であることがさらに好ましく、３５０ｍＮ／ｃｍ以上であることが最も好ましい。接着強度は高い方が半導体素子の飛散を防止することができるので、上限は特にないが、入手しやすい材料・適切な製造プロセスで製造できるものは通常２５０００ｍＮ／ｃｍ以下であり、１００００ｍＮ／ｃｍ以下のものは比較的製造しやすい。
また本発明の一態様としての接着シートにおいて、放射線照射前後の粘接着剤層／基材層界面の前記９０°ピール剥離力による接着強度比（照射後接着強度／照射前接着強度）が０．５以下であり、０．４以下であることがより好ましく、０．３以下であることがさらに好ましい。この値が０．５よりも大きいと、ピックアップ時に各素子を傷つける傾向がある。一方、前記接着強度比（照射後接着強度／照射前接着強度）の下限は特に制限されるものではないが、例えば作業性の観点からは、０．０００１以上であることが好ましい。
また本発明の一態様としての接着シートにおいて、放射線照射前後の粘接着剤層／基材層界面の前記９０°ピール剥離力による接着強度差（照射前接着強度−照射後接着強度）は１００ｍＮ／ｃｍ以上であり、１５０ｍＮ／ｃｍ以上であることがより好ましく、２００ｍＮ／ｃｍであることがさらに好ましく、２５０ｍＮ／ｃｍ以上であることが最も好ましい。この値が１００ｍＮ／ｃｍ未満だと、ピックアップ時に各素子を傷つける傾向がある。
本発明の一態様としての接着シートは、前記粘接着剤層の放射線照射前の１６０℃におけるフロー量を１００〜１００００μｍにし、放射線照射前の９０°ピール剥離力を２００ｍＮ／ｃｍ以上で、放射線照射前後の粘接着剤層／基材層界面の前記９０°ピール剥離力による接着強度差（照射前接着強度−照射後接着強度）を１００ｍＮ／ｃｍ以上にすることによって、低温でダイシングすべき半導体ウェハに上記接着シートを圧着できるにもかかわらず、ダイシング時には半導体素子が飛散しない十分な粘着力を有し、ピックアップ時には各素子を傷つけることがないような低い粘着力を有する、という相反する特性も満足できるため、プロセスコスト上非常に有利になるとともに、放射線照射前後のフロー量比（照射後フロー量／照射前フロー量）が０．１以上にすることによって、半導体素子と支持部材との接合工程では接続信頼性に優れる接着シートとして作用する。
また、本発明の接着シートは、前記粘接着剤層の放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓであり、５０〜１００００Ｐａ・ｓであることがより好ましく、５０〜１０００Ｐａ・ｓであることがさらに好ましい。溶融粘度が５０Ｐａ・ｓに満たないと、ダイシングすべき半導体ウェハに上記接着シートが充分に粘着しない可能性があり、１０００００Ｐａ・ｓを超えると、ハンドリング性等の作業性が低下する可能性がある。
また本発明の一態様としての接着シートにおいて、前記粘接着剤層の放射線照射前後の溶融粘度比（照射後溶融粘度／照射前溶融粘度）が１００以下であり、９５以下であることがより好ましく、９０以下であることがさらに好ましい。この値が１００を超えると、半導体素子と支持部材との接合工程において、半導体素子が充分に接合できない可能性がある。
本発明の一態様としての接着シートは、前記粘接着剤層の放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓにし、放射線照射前記９０°ピール剥離力を２００ｍＮ／ｃｍ以上で、さらに、放射線照射前後の粘接着剤層／基材層界面の前記９０°ピール剥離力による接着強度差（照射前接着強度−照射後接着強度）を１００ｍＮ／ｃｍ以上にすることによって、低温でダイシングすべき半導体ウェハに上記接着シートを圧着できるにもかかわらず、ダイシング時には半導体素子が飛散しない十分な粘着力を有し、ピックアップ時には各素子を傷つけることがないような低い粘着力を有する、という相反する特性も満足できるため、プロセスコスト上非常に有利になるとともに、放射線照射前後の溶融粘度比（照射後溶融粘度／照射前溶融粘度）を１００以下にすることによって、半導体素子と支持部材との接合工程では接続信頼性に優れる接着シートとして作用する。
（第３の態様）
また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ２）放射線照射前の前記粘接着剤層の５．１ｍｍΦプローブ測定による２５℃におけるタック強度が０．５Ｎ以上であり、かつ、（Ｂ１）放射線照射前の１６０℃におけるフロー量が１００〜１００００μｍ、である接着シートが挙げられる。
（第４の態様）
また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ２）放射線照射前の前記粘接着剤層の５．１ｍｍΦプローブ測定による２５℃におけるタック強度が０．５Ｎ以上であり、かつ、（Ｂ２）放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓである接着シートが挙げられる。
本発明の一態様としての接着シートは、前記粘接着剤層の放射線照射前の５．１ｍｍφプローブ測定による２５℃のおけるタック強度が０．５Ｎ以上であり、０．６Ｎ以上であることがより好ましく、０．７Ｎ以上であることがさらに好ましく、０．８Ｎ以上であることが最も好ましい。この値が０．５Ｎに満たないと、ダイシング時に半導体素子が飛散する可能性がある。
また、本発明の一態様としての接着シートは、前記粘接着剤層の放射線照射前後の５．１ｍｍφプローブ測定による２５℃のおけるタック強度差（照射後タック強度−照射前タック強度）が０．１Ｎ以上であり、０．１５Ｎ以上であることがより好ましく、０．２Ｎ以上であることがさらに好ましい。この値が０．１Ｎに満たないと、ピックアップ時に各素子を傷つける傾向がある。
前記第４の態様にあっては、半導体素子と支持部材との接合工程において半導体素子が好適に接合できるという観点から、前記接着シートにおいて、放射線照射前後のフロー量比（照射後フロー量／照射前フロー量）が０．１以上であることが好ましく、また、放射線照射前後の溶融粘度比（照射後溶融粘度／照射前溶融粘度）が１００以下であることが好ましい。
本発明の一態様としての接着シートは、前記粘接着剤層の放射線照射前の１６０℃におけるフロー量を１００〜１００００μｍにし、前記粘接着剤層の放射線照射前の５．１ｍｍφプローブ測定による２５℃のおけるタック強度を０．５Ｎ以上で、前記粘接着剤層の放射線照射前後の５．１ｍｍφプローブ測定による２５℃のおけるタック強度差（照射後タック強度−照射前タック強度）が０．１Ｎ以上にすることによって、低温でダイシングすべき半導体ウェハに上記接着シートを圧着できるにもかかわらず、ダイシング時には半導体素子が飛散しない十分な粘着力を有し、ピックアップ時には各素子を傷つけることがないような低い粘着力を有する、という相反する特性も満足できるため、プロセスコスト上非常に有利になるとともに、放射線照射前後のフロー量比（照射後フロー量／照射前フロー量）が０．１以上にすることによって、半導体素子と支持部材との接合工程では接続信頼性に優れる接着シートとして作用する。
また、本発明の一態様としての接着シートは、前記粘接着剤層の放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓにし、前記粘接着剤層の放射線照射前の５．１ｍｍφプローブ測定による２５℃のおけるタック強度を０．５Ｎ以上で、前記粘接着剤層の放射線照射前後の５．１ｍｍφプローブ測定による２５℃のおけるタック強度差（照射後タック強度−照射前タック強度）が０．１Ｎ以上にすることによって、低温でダイシングすべき半導体ウェハに上記接着シートを圧着できるにもかかわらず、ダイシング時には半導体素子が飛散しない十分な粘着力を有し、ピックアップ時には各素子を傷つけることがないような低い粘着力を有する、という相反する特性も満足できるため、プロセスコスト上非常に有利になるとともに、放射線照射前後の溶融粘度比（照射後溶融粘度／照射前溶融粘度）を１００以下にすることによって、半導体素子と支持部材との接合工程では接続信頼性に優れる接着シートとして作用する。
また、以上に述べた第１〜第４の態様において、ピックアップ時に各素子を傷つけない為には、放射線照射後の前記接着強度は１００ｍＮ／ｃｍ以下であることが好ましい。ただし、比較的厚い半導体ウェハに接着する場合は、これ以上であっても構わない。１００ｍＮ／ｃｍ以下とは、これ以下であればどのような厚さの半導体ウェハ（例えば例えば厚さ２０μｍのような極めて薄い半導体ウェハ）にも適用できる値として挙げられたものである。
粘接着剤層の、前記放射線照射前の接着強度及びタック強度を所望の範囲に調節する方法としては、粘接着剤層の室温における流動性を上昇させることにより、接着強度及びタック強度も上昇する傾向があり、流動性を低下させれば接着強度及びタック強度も低下する傾向があることを利用すればよい。例えば、流動性を上昇させる場合には、可塑剤の含有量の増加、粘着付与材含有量の増加等の方法がある。逆に流動性を低下させる場合には、前記化合物の含有量を減らせばよい。前記可塑剤としては、例えば、単官能のアクリルモノマー、単官能エポキシ樹脂、液状エポキシ樹脂、アクリル系樹脂、エポキシ系のいわゆる希釈剤等が挙げられる。
また粘接着剤層の、前記放射線照射前のフロー量を向上させる方法又は前記放射線照射前溶融粘度を低下させる方法としては、例えば、希釈剤の添加、よりＴｇの低い熱可塑性樹脂の使用、よりＴｇの低いエポキシ樹脂及び硬化剤の使用等が挙げられる。より具体的には、熱可塑性樹脂としてポリイミドを使用する場合には、ポリイミドのイミド基濃度が少なくなるように酸モノマー及びジアミンモノマーを選択し、ポリイミドを合成すればＴｇの比較的低いポリイミドが得られる。また、アクリルゴムを使用する場合には、アクリルゴムの側鎖のアルキル基の炭素数を増やしたり、主鎖の屈曲性を上げたりすることにより、Ｔｇを低下させることが可能である。
（第５の態様）
また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ｃ１）放射線照射前後の粘接着剤層／基材層界面の接着強度差（放射線照射前の接着強度−放射線照射後の接着強度）が１００ｍＮ／ｃｍ以上であり、かつ、（Ｄ１）放射線照射前の１２０℃におけるｔａｎδが０．１以上、放射線照射後の１８０℃におけるｔａｎδが０．１以上である接着シートが挙げられる。
（第６の態様） また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ｃ１）放射線照射前後の粘接着剤層／基材層界面の接着強度差（放射線照射前の接着強度−放射線照射後の接着強度）が１００ｍＮ／ｃｍ以上であり、かつ、（Ｄ２）放射線照射前の１２０℃における貯蔵弾性率が１０ＭＰａ以下、放射線照射後の１８０℃における貯蔵弾性率が１００ＭＰａ以下である接着シートが挙げられる。
前記第５及び第６の態様において、粘接着剤層の流動性を制御できる観点からは特性（Ｄ１）を有する接着シートが用いられ、接着シートを半導体ウェハにラミネートしたとき十分な粘接着力を有し、半導体素子を接着したとき２００℃以下の温度で充分な接着性を有する観点からは特性（Ｄ２）を有する接着シートが用いられる。また、前記接着シートにおいて、ダイシング時とピックアップ時の良好な作業性を両立する観点からは放射線照射前後の粘接着剤層／基材層界面の接着強度比（放射線照射後の接着強度／放射線照射前の接着強度）が０．５以下であることが好ましい。さらに、前記接着シートにおいて、ダイシング時とピックアップ時のより良好な作業性を両立する観点からは粘接着剤層と基材層との界面における放射線照射前の接着強度が２００ｍＮ／ｃｍ以上であり、放射線照射後の前記接着強度が１００ｍＮ／ｃｍ以下であることが好ましい。
本発明の一態様としての接着シートにおいて、放射線照射前の粘接着剤層の１２０℃におけるｔａｎδは、０．１以上が好ましく、０．３以上がより好ましい。また、放射線照射後の粘接着剤層の１８０℃におけるｔａｎδが０．１以上であることが好ましい。それぞれのｔａｎδが０．１未満であると、前者については、室温〜１５０℃のいずれかの温度で前記粘接着剤層を介して接着シートを半導体ウェハにラミネートしたとき、半導体ウェハに対して十分な粘接着力を確保することができない。また、後者については、粘接着剤層を介して半導体素子を支持部材に接着するとき、２００℃以下の温度で十分な接着性を確保できない。このように、ｔａｎδを規定することにより、ある温度での粘接着剤層の流動性を精度よく数値化でき、半導体ウェハへのラミネート及びその後のダイボンド時に必要な粘接着剤層の流動性を管理できる。
また、前記接着シートにおいて、粘接着剤層と基材層との界面における放射線照射前の接着強度が２００ｍＮ／ｃｍ以上であり、２５０ｍＮ／ｃｍ以上であることがより好ましく、３００ｍＮ／ｃｍ以上であることがさらに好ましい。この値が２００ｍＮ／ｃｍに満たないと、ダイシング時に半導体素子が飛散する可能性がある。一方、放射線照射後の前記接着強度は１００ｍＮ／ｃｍ以下であることが好ましい。この値が１００ｍＮ／ｃｍよりも大きいと、ピックアップ時に各素子を傷つける傾向がある。
さらに、前記接着シートにおいて、放射線照射前後の粘接着剤層／基材層界面の接着強度差及び接着強度比については、第１から第４の態様で述べたものと同様の値が、同様の理由で適用することができる。
また、本発明の一態様としての接着シートにおいて、粘接着剤層の放射線照射前の１２０℃における貯蔵弾性率が１０ＭＰａ以下、より好ましくは５ＭＰａ以下、さらに好ましくは２ＭＰａ以下、放射線照射後の１８０℃における貯蔵弾性率が１００ＭＰａ以下、より好ましくは５０ＭＰａ以下、さらに好ましくは１０ＭＰａ以下である。前者については、貯蔵弾性率が１０ＭＰａよりも大きいと、室温〜１５０℃のいずれかの温度で前記粘接着剤層を介して接着シートを半導体ウェハにラミネートしたとき、半導体ウェハに対して十分な粘接着力を確保することができない。また、後者については、貯蔵弾性率が１００ＭＰａよりも大きいと、粘接着剤層を介して半導体素子を支持部材に接着するとき、２００℃以下の温度で十分な接着性を確保できない。
（第７の態様）
また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ｃ２）放射線照射前後の粘接着剤層の２５℃におけるタック強度の差（放射線照射前の２５℃におけるタック強度−放射線照射後の２５℃におけるタック強度）が０．１Ｎ／５．１ｍｍΦプローブ以上であり、かつ、（Ｄ１）放射線照射前の１２０℃におけるｔａｎδが０．１以上、放射線照射後の１８０℃におけるｔａｎδが０．１以上である接着シートが挙げられる。
（第８の態様） また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ｃ２）放射線照射前後の粘接着剤層の２５℃におけるタック強度の差（放射線照射前の２５℃におけるタック強度−放射線照射後の２５℃におけるタック強度）が０．１Ｎ／５．１ｍｍΦプローブ以上であり、かつ、（Ｄ２）放射線照射前の１２０℃における貯蔵弾性率が１０ＭＰａ以下、放射線照射後の１８０℃における貯蔵弾性率が１００ＭＰａ以下である接着シートが挙げられる。
前記第７及び第８の態様において、粘接着剤層の流動性を制御できる観点からは特性（Ｄ１）を有する接着シートが用いられ、接着シートを半導体ウェハにラミネートしたとき十分な粘接着力を有し、半導体素子を接着したとき２００℃以下の温度で充分な接着性を有する観点からは特性（Ｄ２）を有する接着シートが用いられる。また、前記接着シートにおいて、ダイシング時とピックアップ時の良好な作業性を両立する観点からは観点からは放射線照射前後の粘接着剤層／基材層界面の接着強度比（放射線照射後の接着強度／放射線照射前の接着強度）が０．５以下であることが好ましい。また、ダイシング時とピックアップ時のより良好な作業性を両立する観点からはの観点からは前記接着シートにおいて、粘接着剤層と基材層との界面における放射線照射前の接着強度が２００ｍＮ／ｃｍ以上であり、放射線照射後の前記接着強度が１００ｍＮ／ｃｍ以下であることが好ましい。
また、前記接着シートにおいて、放射線照射前後の粘接着剤層の２５℃におけるタック強度の差（放射線照射前の２５℃におけるタック強度−放射線照射後の２５℃におけるタック強度）は、各素子を傷つけずにピックアップすることが可能になる点で、０．１Ｎ／５．１ｍｍΦプローブ以上であることを特徴とし、０．１５Ｎ／５．１ｍｍΦプローブ以上が好ましく、０．２Ｎ／５．１ｍｍΦプローブ以上がより好ましい。
また、前記接着シートにおいて、放射線照射前の粘接着剤層の２５℃におけるタック強度が０．５Ｎ／５．１ｍｍΦプローブ以上であり、放射線照射後の粘接着剤層の２５℃におけるタック強度が０．４Ｎ／５．１ｍｍΦプローブ以下であることが好ましい。放射線照射前の粘接着剤層の２５℃におけるタック強度が０．５Ｎ／５．１ｍｍΦプローブに満たないと、ダイシング時に半導体素子が飛散する可能性がある。一方、放射線照射後の粘接着剤層の２５℃におけるタック強度が０．４Ｎ／５．１ｍｍΦプローブよりも大きいと、ピックアップ時に各素子を傷つける傾向がある。
また、以上に述べた第５〜第８の態様において、放射線照射前（ダイシング時）の前記接着強度は、ダイシング時に半導体素子が飛散しないようにできる点で、２００ｍＮ／ｃｍ以上であることが好ましく、２５０ｍＮ／ｃｍ以上であることがより好ましく、３００ｍＮ／ｃｍ以上であることがさらに好ましく、３５０ｍＮ／ｃｍ以上であることが最も好ましい。接着強度は高い方が半導体素子の飛散を防止することができるので、上限は特にないが、入手しやすい材料・適切な製造プロセスで製造できるものは通常２５０００ｍＮ／ｃｍ以下であり、１００００ｍＮ／ｃｍ以下のものは比較的製造しやすい。また、ピックアップ時に各素子を傷つけない為には、放射線照射後の前記接着強度は１００ｍＮ／ｃｍ以下であることが好ましい。ただし、比較的厚い半導体ウェハに接着する場合は、これ以上であっても構わない。１００ｍＮ／ｃｍ以下とは、これ以下であればどのような厚さの半導体ウェハ（例えば厚さ２０μｍのような極めて薄い半導体ウェハ）にも適用できる値として挙げられたものである。
前記（Ｃ１）放射線照射前後の接着強度の差を大きくする方法、又は前記（Ｃ２）放射線照射前後のタック強度の差を大きくする方法としては、例えば、熱可塑性樹脂、熱硬化性樹脂及び放射線照射により塩基を発生する化合物を必須成分とする粘接着剤層において、熱硬化性樹脂及び塩基を発生する化合物の使用割合を増加させることによって達成することができる。しかし、前記接着強度の差及びタック強度の差を大きくすると、同時に前記放射線照射前後のフロー量の比及び溶融粘度の比が増加する傾向があるので、これらのバランスをとりながら熱硬化性樹脂及び塩基を発生する化合物の使用割合を決定することが好ましい。
前記放射線照射前の１２０℃におけるｔａｎδ及び放射線照射後の１８０℃におけるｔａｎδを上昇させる方法、又は放射線照射前の１２０℃における貯蔵弾性率及び放射線照射後の１８０℃における貯蔵弾性率を低下させる方法としては、粘接着層の流動性が上昇するような公知の手法を用いればよい。具体的には、例えば、希釈剤の添加、よりＴｇの低い熱可塑性樹脂の使用又はよりＴｇの低い熱硬化性樹脂及び硬化剤の使用等が挙げられる。粘接着剤層全体のＴｇとしては、放射線照射前で１２０℃前後、放射線照射後に１８０℃前後になるように材料を選ぶと、その後の最適化が行いやすくなる。
（第９の態様） また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、未硬化あるいは半硬化状態において、５０℃での貯蔵弾性率が０．１ＭＰａ以上２００ＭＰａ以下であり、一定量の放射線を照射した後において５０℃での貯蔵弾性率が照射前の２倍以上、かつ、一定量の放射線を照射した後の１６０℃でのフロー量が１００μｍ以上１００００μｍ以下である接着シートが挙げられる。
（第１０の態様） また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、未硬化あるいは半硬化状態において、５０℃での貯蔵弾性率が０．１ＭＰａ以上２００ＭＰａ以下であり、一定量の放射線を照射した後において５０℃での貯蔵弾性率が照射前の２倍以上、かつ、１６０℃での溶融粘度が５０Ｐａ・ｓ以上１０^６Ｐａ・ｓ以下である接着シートが挙げられる。
（第１１の態様） また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、未硬化あるいは半硬化状態において、５０℃での貯蔵弾性率が０．１ＭＰａ以上２００ＭＰａ以下であり、一定量の放射線を照射した後において５０℃での貯蔵弾性率が照射前の２倍以上、かつ、１８０℃での貯蔵弾性率が１００ＭＰａ以下である接着シートが挙げられる。
上記第９、第１０、及び第１１の態様の接着シートにおいては、未硬化あるいは半硬化状態の接着シートの５０℃での貯蔵弾性率は０．１〜２００ＭＰａであることが必要であり、０．５〜１５０ＭＰａが好ましく、１．０〜１００ＭＰａがより好ましく、２〜５０ＭＰａが特に好ましい。貯蔵弾性率が０．１ＭＰａ未満であるとダイシングの際、半導体素子の破損等が発生し易いため不適当である。２００ＭＰａ超であると、ウェハとのラミネートが出来ないため不適当である。２〜５０ＭＰａの場合は、ダイシング性、ウェハとのラミネート性ともに最も良好である点で好ましい。
また、一定量の放射線を照射した接着シートの５０℃での貯蔵弾性率が照射前の２倍以上である必要があり、２倍未満であると、放射線照射後に半導体素子を基材フィルムから剥離しにくいため、好ましくない。薄型の半導体素子等を容易に基材フィルムから剥離出来る点でさらに好ましくは４倍以上、特に好ましくは１０倍以上である。
本発明の一態様の接着シートにおいて、未硬化あるいは半硬化状態の接着シートに一定量の放射線を照射した後の接着シートの１６０℃でのフロー量は１００μｍ以上、１００００μｍの範囲にあることが必要である。フロー量が１００μｍ未満の場合、半導体素子の圧着時に流動性及びぬれ性が不足し、接着性が低下する点で好ましくない。またフロー量が１００００μｍ超の場合、半導体素子の圧着時に樹脂が半導体素子の端部から過剰に流出するため、半導体素子の支持部材の電極端子部を被覆し、ワイヤボンディングなどの工程が難しくなる点、また、接着シートの膜厚が低下するため、接着性が低下する点で好ましくない。
フロー量は、半導体素子端部からの樹脂の流出がより小さい点で１００μｍ以上、６０００μｍ以下の範囲が好ましい。また、半導体素子の支持部材として回路付きテープや回路付き基板を使用する場合には、回路充填性が高く、かつ端部からの樹脂の流出がより小さい点で、フロー量は１０００μｍ〜４０００μｍの範囲にあることが好ましい。
未硬化あるいは半硬化状態の接着シートの１６０℃でのフロー量Ａと該接着シートに一定量の放射線を照射した後のフロー量ＢがＢ／Ａ≧１／１０の関係を満たす場合、放射線照射量や条件のばらつきがある程度あったとしても放射線照射後のフロー量のばらつきが少ない点で好ましい。また、放射線照射後のフロー量のばらつきがより少ない点Ｂ／Ａ≧１／５がさらに好ましく、Ｂ／Ａ≧１／２が最も好ましい。
本発明の一態様の接着シートにおいて、粘接着層に一定量の放射線を照射した後の１６０℃での溶融粘度は５０〜１０００００Ｐａ・ｓであることが必要である。溶融粘度が５０Ｐａ・ｓ未満の場合には流動性が過剰であり、端部からの樹脂の流出が大きく、また、そのため、接着シートの膜厚が低下するため、接着性が低下する傾向がある。また、１０００００Ｐａ・ｓ超の場合には、流動性が低く、接着性や回路充填性が低下する傾向がある。
また、未硬化あるいは半硬化状態の接着シートに一定量の放射線を照射した後の５０℃での貯蔵弾性率が１５ＭＰａ以上であると、薄型の半導体素子等を容易に基材フィルムから剥離出来る点で特に好ましい。
さらには、低温でラミネート可能である点で未硬化あるいは半硬化状態の接着シートの１００℃での貯蔵弾性率が０．０００１〜２ＭＰａであり、ダイシングし易い点で５０℃での貯蔵弾性率が０．１〜２００ＭＰａであり、剥離し易い点で放射線照射後に、５０℃での貯蔵弾性率が１５〜２００ＭＰａであり、流動性が高い点で１８０℃での貯蔵弾性率が１００ＭＰａ以下であることが好ましく、また、耐熱性が良い点で硬化後に５０℃での貯蔵弾性率が１００〜５０００ＭＰａであることが特に好ましい。前記未硬化あるいは半硬化状態の接着シートの５０℃における貯蔵弾性率としては、さらにダイシング作業性に優れる点で、５〜１００ＭＰａであることが好ましく、７．５〜５０ＭＰａであることがより好ましい。
本発明の一態様の接着シートにおいて、粘接着層は加熱硬化した段階で、貯蔵弾性率が２５℃で１０〜２０００ＭＰａであり、２６０℃で３〜５０ＭＰａであることが好ましい。２５℃での貯蔵弾性率は、２０〜１９００ＭＰａがより好ましく、５０〜１８００ＭＰａが特に好ましい。また、２６０℃での貯蔵弾性率は、４〜５０ＭＰａがより好ましく、５〜５０ＭＰａが特に好ましい。貯蔵弾性率がこの範囲にあると、半導体素子と支持部材との熱膨張係数の差によって発生する熱応力を緩和させる効果が保たれ、剥離やクラックの発生を抑制できるとともに、接着剤の取り扱い性、接着剤層の厚み精度、リフロークラックの発生を抑制できる。
前記加熱硬化した段階での粘接着剤層の貯蔵弾性率は、例えばエポキシ樹脂の使用量を増やしたり、グリシジル基濃度の高いエポキシ樹脂又は水酸基濃度の高いフェノール樹脂を使用する等してポリマー全体の架橋密度を上げたりすることによって、増加させることができる。上記と逆の手段をとれば貯蔵弾性率の値も低下することはいうまでもない。
本発明の一態様の接着シートにおいて、放射線照射後の接着シートの粘接着剤層を介して、５ｍｍ角の半導体素子と支持部材とを接着した積層硬化物の２５０℃での接着強度（引き剥がし強度）が３．０Ｎ／チップ以上であることが好ましい。半導体素子と支持部材との間における剥がれ方としては、粘接着剤層と支持部材との間で剥離する界面破壊と、粘接着層が破壊して剥離する凝集破壊とに大別される。界面破壊を抑えるためには粘接着剤層の流動性を上げたり、放射線照射後の粘接着剤層のフロー量を上げたりする手法が有効であり、凝集破壊を抑えるためには粘接着剤層の架橋密度が高くなるように材料を選択すること、熱可塑性樹脂の分子量を上げること、２６０℃における弾性率を０．０１〜５０ＭＰａの範囲にすること等の手法が有効である。
以上のようにいくつかの具体的な態様を挙げながら説明したが、前記各種特性は、より優れた接着シートを得るために有効な特性であるので、それらを適宜組み合わせることによって、より優れた接着シートを得ることができるのはいうまでもない。
（硬化度の調整）
本発明の一態様としての接着シートは、粘接着剤層に熱可塑性樹脂及び熱硬化性樹脂を主成分として含有したものとする場合、前記接着シートに放射線を照射したときの粘接着剤層のＤＳＣによる発熱量をＡ、放射線照射前の発熱量をＢとしたとき、（Ｂ−Ａ）／Ｂ＝０．１〜０．７である構成を有することが好ましい。
前記接着シートにおいて、放射線を照射したときの粘接着剤層のＤＳＣによる発熱量をＡ、放射線照射前の発熱量をＢとしたとき、（Ｂ−Ａ）／Ｂ＝０．１〜０．７が好ましく、より好ましくは０．２〜０．５である。放射線照射後のピックアップ時に半導体素子に損傷を与えない為には、０．１以上であることが好ましい。また、ピックアップ後、粘接着剤層を介して半導体素子を支持部材に加熱接着するとき、十分な流動性を確保するためには０．７以上が好ましい。
なお、上記のＤＳＣによる発熱量とは、後に評価方法の欄で説明するように示唆走査熱量計（本明細書において「ＤＳＣ」ともいう。）を用いて、昇温速度１０℃／分、測定温度２０℃〜３００℃の条件で測定したときに求められる値である。
また、前記粘接着剤層には、放射線照射によって熱硬化性樹脂の硬化反応を促進する光反応性化合物を含有することを特徴とする。さらに、前記光反応性化合物が波長１５０〜７５０ｎｍの放射線照射によって塩基を発生する化合物であることを特徴とする。
上記の放射線照射によって塩基を発生する化合物は、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。使用する光塩基発生剤の例は先に述べた通りである。
前記接着シートにおいて、使用する熱可塑性樹脂のＴｇは−５０〜１０℃、かつ重量平均分子量は１０００００〜１００００００である。Ｔｇが−５０℃を下回ると粘接着剤層としての自己支持性がなくなり、取り扱い性に問題が生じ、Ｔｇが１０℃を超えると、接着に要する温度が高くなり、いずれも好ましくない。（なお、本発明におけるＴｇは、後に評価方法の欄で説明するようにＤＳＣを用いて測定した値を示す。）また、重量平均分子量がこの範囲にあると、シート状又はフィルム状としたときの強度、可とう性、及びタック性が適当であり、また、フロー性が適当のため配線の良好な回路充填性が確保できる。重量平均分子量が上記の範囲外にあると、シート状又はフィルム状としたときの上記特性が損なわれるので好ましくない。なお、本発明において、重量平均分子量とは、後に評価方法の欄で説明するようにゲルパーミュエーションクロマトグラフィー（本明細書において「ＧＰＣ」ともいう。）で測定し、標準ポリスチレン検量線を用いて換算した値を示す。
また、前記接着シートにおいて、使用する熱可塑性樹脂のＴｇは１０〜１００℃、かつ重量平均分子量は５０００〜２０００００である。上記Ｔｇについて、より好ましくは１０〜８０℃である。Ｔｇが１０℃を下回ると粘接着剤層としての自己支持性がなくなり、取り扱い性に問題が生じ、Ｔｇが１００℃を超えると、接着に要する温度が高くなり、いずれも好ましくない。なお、本発明におけるＴｇは、ＤＳＣにより求められる値を示す。また、上記重量平均分子量について、より好ましくは２００００〜１５００００であり、さらに好ましくは２００００〜８００００である。重量平均分子量がこの範囲にあると、シート状又はフィルム状としたときの強度、可とう性、及びタック性が適当であり、また、フロー性が適当のため配線の良好な回路充填性が確保できる。重量平均分子量が上記の範囲外にあると、シート状又はフィルム状としたときの上記特性が損なわれるので好ましくない。なお、上記の重量平均分子量とは、ゲルパーミュエーションクロマトグラフィーで測定し、標準ポリスチレン検量線を用いて換算した値を示す。
（粘接着剤層の化学構造） 作業工程の簡略化を図ることができるといった上記の作用・効果を有する本発明の接着シートのさらなる最適化を図るべく粘接着剤層の化学構造的側面から検討した結果、本発明者らは、以下に説明するような特性を有する粘接着層とすることで、より好適に前記作用効果が得られることを見出した。
すなわち、本発明の一態様としての接着シート及びそれを構成する樹脂組成物は、放射線照射及び加熱前は架橋網目構造を有しない海島相分離樹脂において、放射線照射により、架橋網目構造を形成する樹脂からなる島相及び、放射線照射では架橋網目構造を形成しないが、加熱により架橋構造を形成する樹脂からなる海相を有することが好ましい。
Ｂステージ状態における接着性を付与するために、放射線照射前は架橋網目構造を有しないことが好ましい。さらに、放射線照射後の分子構造を検討した結果、海相が網目構造を形成した場合、流動性が低下し、接着性が低下する傾向があり、また、島相が網目構造を形成しない場合、粘着性が高く剥離しにくくなる傾向があることがわかった。すなわち、接着シートに放射線を照射したとき、接着性の点で島相は架橋網目構造を形成することが好ましく、一方で海相は粘接着層を基材層から剥離することが容易になる点で架橋網目構造を形成しないことが好ましい。
放射線照射及び加熱硬化後には、海相、島相ともに架橋網目構造を有することが耐熱性を付与する上で必要である。海島構造については、試料断面をＳＥＭ観察して、分散している部分を島相、連続相を島相と判定した。放射線照射量及び波長に関しては、上記の効果が発現するよう調整する。
また、各相の架橋網目構造の形成は以下のようにして判定した。すなわち、試料（重量Ｘｇ）をＭＥＫ１０ｇ中に２５℃で１ｈ浸透させた後、２００メッシュのナイロン布で不溶物を除去した。その濾過物（溶解成分）を１７０℃１ｈ乾燥したものの重量Ｙを測定し、初期試料と重量比Ｙ／Ｘ×１００（％）から、溶解成分比率（％）を測定した。溶解成分比率が８０％未満の場合、網目構造を形成し、不溶の部分を形成していることから、海相が架橋網目構造を形成していると判定した。また、溶解成分比率が８０％以上の場合で、濾過物の５ｍｍ厚さのセルでの可視光透過率が８０％以上のものを海相、島相ともに架橋網目構造を有していると判断した。濾過物の５ｍｍ厚さのセルでの可視光透過率が８０％未満のものを海相は架橋網目構造を有していないが、島相は架橋網目構造を有していると判断した。
放射線照射によって、上記の特性を有する海島構造を形成する樹脂の組み合わせとしては、例えば、初期には高分子量成分と相溶する低分子量熱硬化成分との組み合わせ等が挙げられ、このうち、耐熱性、接着性に優れる点でグリシジル基含有（メタ）アクリル共重合体とエポキシ樹脂との組み合わせが好ましい。
放射線照射前後の粘接着剤層／基材層界面の前記９０°ピール剥離力による接着強度比（照射後接着強度／照射前接着強度）が０．５以下であり、０．４以下であることがより好ましく、０．３以下であることがさらに好ましい。この値が０．５よりも大きいと、ピックアップ時に各素子を傷つける傾向がある。一方、前記接着強度比（照射後接着強度／照射前接着強度）の下限は特に制限されるものではないが、例えば作業性の観点からは、０．０００１以上であることが好ましい。なお、ダイシング時（放射線照射前）の前記粘接着剤層と前記基材層界面の粘着力は、ダイシングすべき半導体ウェハに上記接着シートを室温又は加熱しながら圧着して貼り付けた後、基材層のみを、引張り角度：９０°、引張り速度：５０ｍｍ／ｍｉｎで引っ張った時のピール剥離力で測定できる。
また前記接着シートにおいて、放射線照射前後の粘接着剤層／基材層界面の前記９０°ピール剥離力による接着強度差（照射前接着強度−照射後接着強度）は１００ｍＮ／ｃｍ以上であり、１５０ｍＮ／ｃｍ以上であることがより好ましく、２００ｍＮ／ｃｍであることがさらに好ましく、２５０ｍＮ／ｃｍ以上であることが最も好ましい。この値が１００ｍＮ／ｃｍ未満だと、ピックアップ時に各素子を傷つける傾向がある。
未硬化あるいは半硬化状態の接着シートに一定量の放射線を照射した後の接着シートの１６０℃でのフロー量は１００μｍ以上、１００００μｍの範囲にあることが好ましい。
＜製造方法＞
本発明の接着シートは、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。
本発明の接着シートは、ダイシング工程終了後、１５０〜７５０ｎｍの波長域を持つ活性光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。
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、例えば、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、例えば、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、単独で又は２種類以上を組み合わせて使用することができる。
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。
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。
接着シートの厚みは、特に制限はないが、粘接着剤層、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。
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以上の接着剤層又は粘接着剤層を半導体ウェハと粘接着剤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粘接着剤層として、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粘接着剤層として、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、粘接着剤層同士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。
＜使用方法＞
以上説明したような構成を有する接着シートに放射線を照射すると、放射線照射後には粘接着剤層の基材層に対する接着力が大きく低下することとなる。そのため、後に説明するように半導体装置を製造する際のダイシング工程において本発明の接着シートを用いることにより、粘接着剤層と、基材層とが容易に剥離することとなる結果、粘接着剤層を付した半導体素子を好適にピックアップすることができる。
本発明において照射する放射線は、１５０〜７５０ｎｍの波長域を持つ活性光線であり、紫外線、遠紫外線、近紫外線、可視光線、電子線、赤外線、近赤外線などがある。例えば、低圧水銀灯、中圧水銀灯、高圧水銀灯、超高圧水銀灯、キセノンランプ、メタルハライドランプを使用して０．０１〜１００００Ｊ／ｃｍ^２の照射することができる。
前記放射線照射によって、粘接着剤層に含まれる熱重合性樹脂の一部が硬化するため、粘接着剤層と基材層との間の接着力が低下するものと考えられる。前記放射線照射によるのみでは充分な接着力の低下が得られないときには、併せて加熱することにより硬化反応を促進させることが好ましい。前記加熱の温度としては、放射線照射による硬化反応の進行具合によって、また、粘接着剤層の組成によっても異なるが、通常３０〜１００℃の雰囲気に接着シートが曝されればよい。前記加熱は、ヒーターやオーブンを利用しても良いが、一般的な放射線照射源は放射線照射時に発熱することが多く、この発熱を利用すれば、加熱装置を別途準備する必要がないため好ましい。
また、本発明の放射線照射後の前記粘接着剤層と前記基材層界面の粘着力は、例えば、ダイシングすべき半導体ウェハに上記接着シートを室温又は加熱しながら圧着して貼り付けた後、基材層のみを、引張り角度：９０°、引張り速度：５０ｍｍ／ｍｉｎで引張った時のピール剥離力（接着強度）が１００ｍＮ／ｃｍ以下であり、９０ｍＮ／ｃｍ以上であることがより好ましく、８０ｍＮ／ｃｍ以上であることがさらに好ましい。この値が１００ｍＮ／ｃｍを超えると、ピックアップ時に各素子を傷つける傾向がある。
続いて、本発明に係る接着シートの使用方法について図１〜図８を参照しながら説明するが、本発明の使用方法が以下の方法に限定されないことはいうまでもない。尚、図中同一の機能を有するものについては同一の符号を付してその説明を省略する。
図１には基材フィルム１と第１の粘接着剤層２とを備える接着シート１０が開示されており、図２には前記構成要件に加えてさらに第２の粘接着剤層３を備える接着シート２０が開示されている。
これらの接着シート１０、２０をダイシングテープとして使用する場合、まず接着シート１０、２０の前記粘接着剤層２、３とウェハ表面が密着するようにして所定の作業台上に載置する。
尚、本発明に係る接着シートの上面に剥離性シートが設けられている場合には、その剥離性シートを剥離除去した後に、接着シートの前記粘接着剤層２、３を上向きにして所定の作業台上に載置する。
次に、図３に示すようにして、第２の粘接着剤層３の上面にダイシング加工すべき半導体ウェハＡを貼着する。この際、前述のように、所望のシート厚を得るためにさらに１又は２以上の接着剤層又は粘接着剤層を半導体ウェハＡと第２の粘接着剤層３との間に挟むように設けてもよい。
続いて、この貼着状態で半導体ウェハＡにダイシング、洗浄、乾燥の工程が加えられる。この際、第２の粘接着剤層３により半導体ウェハ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ェハＡが脱落することはない。
尚、図４にはダイシングカッター６を用いてウェハＡをダイシングすることで太線で示される切込みが設けられ、そして半導体素子Ａ１、Ａ２、Ａ３が得られることが示されている。
次に、図５に示すように、放射線Ｂを接着シートの粘接着剤層２、３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、粘接着剤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。
接着シートへの放射線照射は、図５中矢印Ｂで示されるように基材フィルム１の粘接着剤層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１は必ずしも光透過性である必要はない。
放射線照射後、図６に示されるようにして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、吸引コレット４に換えて又は吸引コレット４と併用するようにして、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と粘接着剤層３との間の粘着力は、粘接着剤層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、粘接着剤層２は半導体素子Ａ１の下面に付着した状態で剥離する（図７参照）。
次いで、半導体素子Ａ１、Ａ２、Ａ３を粘接着剤層２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。加熱により粘接着剤層２は接着力が発現し、半導体素子Ａ１、Ａ２、Ａ３と半導体素子搭載用支持部材５との接着が完了する（図８参照）。
以上説明してきた本発明の接着シートは、ダイシング工程終了後、紫外線（ＵＶ）あるいは電子線（ＥＢ）などの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、接着剤（層）と基材フィルム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。従来の接着シートの場合、基材の表面張力が４０ｍＮ／ｍを超えると、接着シートと基材界面の接着力の低下が充分でなく、ピックアップ性に劣る傾向があった。しかし、本発明の接着シートは、基材の表面張力が４０ｍＮ／ｍを超えていても、紫外線（ＵＶ）あるいは電子線（ＥＢ）などの放射線照射後に、接着シートと基材界面の接着力が充分に低下し、半導体素子のピックアップが良好になる。したがって、従来は、基材の表面張力が４０ｍＮ／ｍ以下にするために、使用する基材フィルムに表面処理をしていたが、本発明の接着シートでは、基材フィルムを表面処理する必要がなく、コスト的にも有利になる。
以上本発明について説明してきたが、本発明の接着シートの好ましい一態様としてさらに以下の接着シートが挙げられる。
（第１２の態様）
本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層が、官能性モノマーを含む重量平均分子量が１０万以上である高分子量成分を１０〜４００重量部、（ｂ）熱重合性成分を１００重量部、及び（ｃ）放射線照射によって塩基を発生する化合物放射線重合性化合物を０．０１〜２００重量部含有する接着シートが挙げられる。（第１３の態様）
また、本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層が、ポリイミド樹脂を１００重量部、（ｂ）熱重合性成分を１〜２００重量部、及び（ｃ）放射線照射によって塩基を発生する化合物を０．０１〜２００重量部含有する接着シートが挙げられる。
ここで、前記第１２及び１３の態様において、作業性及び耐熱性の観点からは熱重合性成分としてエポキシ樹脂及びエポキシ樹脂硬化剤を用いることが好ましい。（第１４の態様）
本発明の一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ２）放射線照射前の前記粘接着剤層の５．１ｍｍΦプローブ測定による２５℃におけるタック強度が０．５Ｎ以上であり、かつ、（Ｂ１）放射線照射前の１６０℃におけるフロー量が１００〜１００００μｍである接着シートが挙げられる。（第１５の態様）
また本発明の一態様として、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ２）放射線照射前の前記粘接着剤層の５．１ｍｍΦプローブ測定による２５℃におけるタック強度が０．５Ｎ以上であり、かつ、（Ｂ２）放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓである接着シートが挙げられる。
（第１６の態様）
さらに、本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層が、（Ｃ１）放射線照射前後の粘接着剤層／基材層界面の接着強度差（放射線照射前の接着強度−放射線照射後の接着強度）が１００ｍＮ／ｃｍ以上であり、かつ、以下の特性のうち少なくとも一つの特性を有してなる接着シートが挙げられる。
（Ｄ１）放射線照射前の１２０℃におけるｔａｎδが０．１以上、放射線照射後の１８０℃におけるｔａｎδが０．１以上、
（Ｄ２）放射線照射前の１２０℃における貯蔵弾性率が１０ＭＰａ以下、放射線照射後の１８０℃における貯蔵弾性率が１００ＭＰａ以下
ここで、粘接着剤層の流動性を制御できる観点からは特性（Ｄ１）を有する接着シートが用いられ、接着シートを半導体ウェハにラミネートしたとき十分な粘接着力を有し、半導体素子を接着したとき２００℃以下の温度で充分な接着性を有する観点からは特性（Ｄ２）を有する接着シートが用いられる。
（第１７の態様）
さらに、本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層が、（Ｃ２）放射線照射前後の粘接着剤層の２５℃におけるタック強度の差（放射線照射前の２５℃におけるタック強度−放射線照射後の２５℃におけるタック強度）が０．１Ｎ／５．１ｍｍΦプローブ以上であり、かつ、以下の特性のうち少なくとも一つの特性を有してなる接着シートが挙げられる。
（Ｄ１）放射線照射前の１２０℃におけるｔａｎδが０．１以上、放射線照射後の１８０℃におけるｔａｎδが０．１以上、
（Ｄ２）放射線照射前の１２０℃における貯蔵弾性率が１０ＭＰａ以下、放射線照射後の１８０℃における貯蔵弾性率が１００ＭＰａ以下
ここで、粘接着剤層の流動性を制御できる観点からは特性（Ｄ１）を有する接着シートが用いられ、接着シートを半導体ウェハにラミネートしたとき十分な粘接着力を有し、半導体素子を接着したとき２００℃以下の温度で充分な接着性を有する観点からは特性（Ｄ２）を有する接着シートが用いられる。
（第１８の態様）
また、本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記接着シートにおいて、前記粘接着剤層が、未硬化あるいは半硬化状態の５０℃での貯蔵弾性率が０．１ＭＰａ以上２００ＭＰａ以下であり、一定量の放射線を照射した後の５０℃での貯蔵弾性率が照射前の２倍以上であり、かつ、一定量の放射線を照射した後の前記粘接着剤層は、下記（Ｅ）（Ｆ）及び（Ｇ）に示される特性のうち少なくとも一つの特性を有することが好ましい。
（Ｅ）１６０℃でのフロー量が１００μｍ以上１００００μｍ以下、
（Ｆ）１６０℃での溶融粘度が５０Ｐａ・ｓ以上１０^６Ｐａ・ｓ以下、及び
（Ｇ）１８０℃での貯蔵弾性率が１００ＭＰａ以下
（第１９の態様）
さらにまた、本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層とを備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、（Ａ１）放射線照射前の前記粘接着剤層と前記基材層界面の接着強度が２００ｍＮ／ｃｍ以上であり、かつ、以下の特性のうち少なくとも一つの特性を有してなる接着シートが挙げられる。
（Ｂ１）放射線照射前の１６０℃におけるフロー量が１００〜１００００μｍ、
（Ｂ２）放射線照射前の１６０℃における溶融粘度が５０〜１０００００Ｐａ・ｓ
ここで、ダイシング作業性の観点からは特性（Ｂ１）を有する接着シートが用いられ、接着性の観点からは特性（Ｂ２）を有する接着シートが用いられる。また、前記接着シートにおいて、放射線照射前後のフロー量比（照射後フロー量／照射前フロー量）が０．１以上であることが好ましい。また、前記接着シートにおいて、前記粘接着剤層と前記基材層界面の放射線照射前後の接着強度比（照射後接着強度／照射前接着強度）が０．５以下であることが好ましい。さらに、前記接着シートにおいて、前記粘接着剤層と前記基材層界面の放射線照射前後の接着強度差（照射前接着強度−照射後接着強度）が１００ｍＮ／ｃｍ以上であることが好ましい。さらにまた、前記接着シートにおいて、放射線照射前後の溶融粘度比（照射後溶融粘度／照射前溶融粘度）が１００以下であることが好ましい。
（第２０の態様）
さらに、本発明の接着シートの好ましい一態様としては、粘接着剤層と基材層を備え、前記粘接着剤層と前記基材層との間の接着力が放射線の照射により制御される接着シートであって、前記粘接着剤層は、未硬化あるいは半硬化状態の５０℃での貯蔵弾性率が０．１ＭＰａ以上２００ＭＰａ以下であり、一定量の放射線を照射した後の５０℃での貯蔵弾性率が照射前の２倍以上であり、かつ、一定量の放射線を照射した後の前記粘接着剤層は、下記（Ｅ）（Ｆ）及び（Ｇ）に示される特性のうち少なくとも一つの特性を有してなる接着シートが挙げられる。
（Ｅ）１６０℃でのフロー量が１００μｍ以上１００００μｍ以下、
（Ｆ）１６０℃での溶融粘度が５０Ｐａ・ｓ以上１０^６Ｐａ・ｓ以下、及び
（Ｇ）１８０℃での貯蔵弾性率が１００ＭＰａ以下。
また、前記接着シートにおいて、、良好な接着性を得る観点から未硬化あるいは半硬化状態の接着シートの粘接着剤層の１６０℃でのフロー量Ａと前記接着シートに一定量の放射線を照射した後の粘接着剤層のフロー量ＢがＢ／Ａ≧１／１０の関係を満たすことが好ましい。また、未硬化あるいは半硬化状態の接着シートに一定量の放射線を照射した後の粘接着剤層の５０℃での貯蔵弾性率が１５ＭＰａ以上であることが好ましい。さらに、前記粘接着剤層が以下の条件を満たすことが好ましい。
１）未硬化あるいは半硬化状態の１００℃での貯蔵弾性率が０．００１ＭＰａ以上２ＭＰａ以下であり、２）５０℃での貯蔵弾性率が７．５ＭＰａ以上５０ＭＰａ以下であり、３）放射線照射後に、５０℃での貯蔵弾性率が１５ＭＰａ以上１００ＭＰａ以下であり、４）硬化後に５０℃での貯蔵弾性率が１００ＭＰａ以上５０００ＭＰａ以下である。さらにまた、放射線照射後の接着シートの粘接着剤層を用いた５ｍｍ角の半導体素子と支持部材との積層硬化物の２５０℃での接着強度が３．０Ｎ／チップ以上であることが好ましい。加熱硬化後の接着シートの、動的粘弾性測定装置を用いて測定した場合の粘接着剤層の貯蔵弾性率が２５℃で１０ＭＰａ以上２０００ＭＰａ以下であり、２６０℃で３ＭＰａ以上５０ＭＰａ以下であることが好ましい。
また、本発明の別の態様として、以下のような半導体装置の製造方法や半導体装置が提供される。
本発明の接着シートを用いて、半導体素子と半導体素子搭載用支持部材とを、又は半導体素子同士を接着してなる半導体装置の製造方法。
粘接着剤層と基材層を有してなる本発明の接着シートを前記粘接着剤層を挟んで半導体ウェハに貼り付ける工程と；前記半導体ウェハをダイシングして粘接着剤層付き半導体素子を形成する工程と；ダイシング後に前記接着シートに放射線を照射して前記粘接着剤層を硬化しその後前記基材フィルム層を剥離する工程と；前記粘接着剤層付き半導体素子と半導体素子搭載用の支持部材とを又は半導体素子同士を前記接着シートを介して接着する工程と；を有する半導体装置の製造方法。
本発明の接着シートを用いて、半導体素子と半導体素子搭載用支持部材とを、又は半導体素子同士を接着した構造を有してなる半導体装置。
実施例
以下、本発明を実施例を用いてより詳細に説明する。本発明は、これらに限定されるものではない。尚、接着シートについての評価は、各実施例中に特記しない限り後に説明する評価方法の欄で説明する方法に従って行った。
（合成例１）〔光塩基発生剤の合成〕
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。
得られた濃縮液を１０００重量部のｎ−ヘ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（ＰＢ−１）を得た。収量４９．５ｇ（収率９１％）であった。
（合成例２）〔光塩基発生剤の合成〕
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（ＰＢ−２）を得た。収量３．６７ｇ、収率８５％、融点１４６−１４７℃であった。
（合成例３）〔光塩基発生剤の合成〕
ｐ−シアノ安息香酸メチルエステル（２．００ｇ、１２ｍｍｏｌ）、Ｎ，Ｎ−ジメチルヒドラジン（０．７５ｇ、１２ｍｍｏｌ）、フェニルグリシジルエーテル（１．８６ｇ、１２ｍｍｏｌ）をｔｅｒｔ−ブタノール（１０ｇ）に添加し、５０℃で７２時間攪拌した後、さらに室温で４８時間攪拌した。得られた反応溶液をロータリーエバポレータでｔｅｒｔ−ブタノールを除去した後、酢酸エチル１０ｇを加えて再結晶を行って白色のアミンイミド化合物（ＰＢ−３）を得た。収量２．７４ｇ、収率６５％、融点１４８−１４９℃であった。
（合成例４）〔光塩基発生剤の合成〕
フェナシルブロマイド（２．００ｇ、１０．５ｍｍｏｌ）をアセトン（２０ｇ）に溶解させ、これにアセトン（５ｇ）に溶解させた１−ベンジル−２−メチルイミダゾール（１．７３ｇ、１０．５ｍｍｏｌ）の溶液をゆっくり添加し、この後、室温（２５℃）で２時間かくはんしたところ、白色結晶が析出した。これをろ過し、アセトンで２度洗浄を行った後、真空下６０℃で５時間乾燥して、イミダゾリウム・ブロマイド塩１を得た（収量３．５４ｇ）。
上記イミダゾール・ブロマイド塩１（２．００ｇ、５．４ｍｍｏｌ）を、メタノール／水（１５ｇ／１５ｇ）溶液に溶解させ、これに水（５．０ｇ）に溶解させたテトラフェニルほう酸ナトリウム（１．８４ｇ、５．４ｍｍｏｌ）の溶液をゆっくり添加した。添加とともに、白色スラリー状の析出が認められ、添加後、さらに室温で５時間かくはんした。この析出物をろ過し、アセトン（２０ｇ）に溶解させて再結晶を行い、目的のイミダゾリウムテトラフェニルほう酸塩（ＰＢ−４）を得た（収量２．８６ｇ）。この化合物の^１Ｈ−ＮＭＲを図９に示す。また、酸素雰囲気下での融点及び熱分解開始温度をＴＧ−ＤＴＡで測定したところ、融点１８７℃、分解開始温度２２４℃であった。
（合成例５）〔光塩基発生剤の合成〕
ｐ−ニトロフェナシルブロマイド（２．００ｇ、８．２ｍｍｏｌ）をアセトン（２０ｇ）に溶解させ、これにアセトン（５ｇ）に溶解させた１，２−ジメチルイミダゾール（０．７９ｇ、８．２ｍｍｏｌ）の溶液をゆっくり添加し、この後、室温で２時間かくはんしたところ、白色結晶が析出した。これをろ過し、アセトンで２度洗浄を行った後、真空下６０℃で５時間乾燥して、イミダゾリウム・ブロマイド塩２を得た（収量２．６２ｇ）。
上記イミダゾール・ブロマイド塩（２．００ｇ、５．８ｍｍｏｌ）を、メタノール／水（１５ｇ／１５ｇ）溶液に溶解させ、これに水（５．０ｇ）に溶解させたテトラフェニルほう酸ナトリウム塩（２．０１ｇ、５．８ｍｍｏｌ）の溶液をゆっくり添加した。添加とともに、白色スラリー状の析出が認められ、添加後、さらに室温で５時間かくはんした。これをろ過し、アセトン（２０ｇ）に溶解させて再結晶を行い、目的のイミダゾリウム・テトラフェニルほう酸塩（ＰＢ−５）を得た（収量２．８３ｇ）。
この化合物の^１Ｈ−ＮＭＲを図１０に示す。また、酸素雰囲気下での融点及び熱分解開始温度をＴＧ−ＤＴＡで測定したところ、融点１６５℃、分解開始温度１９５℃であった。
（合成例６）〔ポリイミド樹脂の合成〕
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（ＰＩ−１）を得た。
（合成例７）〔ポリイミド樹脂の合成〕
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、１，１２−ジアミノドデカン５．４１ｇ（０．０４５モル）、エーテルジアミン（ＢＡＳＦ製、エーテルジアミン２０００（分子量：１９２３））１１．５４ｇ（０．０１モル）、ポリシロキサンジアミン（信越シリコーン製、ＫＦ−８０１０（分子量：９００））２４．３ｇ（０．０４５モル）及びＮ−メチル−２−ピロリドン１６９ｇ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、４，４‘−（４，４’−イソプロピリデンジフェノキシ）ビス（フタル酸二無水物）３１．２３ｇ（０．１モル）を少量ずつ添加した。室温で８時間反応させたのち、キシレン１１２．７ｇを加え、窒素ガスを吹き込みながら１８０℃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（ＰＩ−２）を得た。
（合成例８）〔ポリイミド樹脂の合成〕
攪拌装置、窒素導入管、乾燥管を備えた１リットルの四つ口のフラスコに、２，２−ビス（４−（４−アミノフェノキシ）フェニル）プロパン４１．０ｇ（０．１０モル）を入れ、窒素気流下、Ｎ−メチル−２−ピロリドン２５０ｇを加えて溶液とした。フラスコを水浴上に移し、激しく攪拌しながら１，２−（エチレン）ビス（トリメリテート二無水物）４１．０ｇ（０．１０モル）を少量ずつ加えた。酸二無水物がほぼ溶解したら、ゆっくりと攪拌しながら６時間反応させ、ポリアミド酸溶液を得た。次に、前記のポリアミド酸溶液が入った四つ口フラスコに蒸留装置を装着し、キシレン２２０ｇを加えた。窒素気流下、１８０℃の油浴上で、激しく攪拌しながら、イミド化により生成する縮合水をキシレンと共に共沸留去した。その反応液を水中に注ぎ、沈殿したポリマーを濾別、乾燥してポリイミド樹脂（ＰＩ−３）を得た。
得られたポリイミド樹脂（ＰＩ−１〜ＰＩ−３）の組成及び物性をまとめて表１に示す。なお、各物性は下記の条件で測定した。
（１２）’Ｔｇ
示唆走査熱量計（以下ＤＳＣと略す）（パーキンエルマー社製、ＤＳＣ−７型）を用いて、昇温速度１０℃／ｍｉｎの条件で測定した。
（１３）’重量平均分子量
ゲルパーミュエーションクロマトグラフィー（以下ＧＰＣと略す）で測定し、標準ポリスチレンで換算した。

尚、表１中の記号は下記のものを示す。
ＢＡＰＰ：２，２−ビス〔４−（４−アミノフェノキシ）フェニル〕プロパンＤＤＯ：１，１２−ジアミノドデカン
ＥＤＡ：エーテルジアミン２０００（分子量：１９２３）
ＫＦ−８０１０：ポリシロキサンジアミン（分子量：９００）
ＤＢＴＡ：１，１０−（デカメチレン）ビス（トリメリテート無水物）
ＢＰＡＤＡ：４，４’−（４，４’−イソプロピリデンジフェノキシ）ビス（フタル酸二無水物）
ＥＢＴＡ：１，２−（エチレン）ビス（トリメリテート二無水物）
次に、製造例１〜２５において表２及び３に示される組成を有する接着シート１〜２５を作製した。接着シート１〜２５の組成を表２及び３にまとめて示す。

（製造例１）
ＹＤＣＮ−７０３（東都化成（株）製商品名、ｏ−クレゾールノボラック型エポキシ樹脂、エポキシ当量２１０）４２．３重量部、フェノライトＬＦ２８８２（大日本インキ化学工業（株）製商品名、ビスフェノールＡノボラック樹脂）２３．９重量部、ＨＴＲ−８６０Ｐ−３（ナガセケムテックス（株）製商品名、エポキシ基含有アクリルゴム、分子量１００万、Ｔｇ−７℃）４４．１重量部、キュアゾール２ＰＺ−ＣＮ（四国化成工業（株）製商品名、１−シアノエチル−２−フェニルイミダゾール）０．４重量部、ＮＵＣ Ａ−１８７（日本ユニカー（株）製商品名、γ−グリシドキシプロピルトリメトキシシラン）０．７重量部、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）０．５重量部からなる組成物に、メチルエチルケトンを加えて攪拌混合し、真空脱気した。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人デュポンフィルム（株）製、テイジンテトロンフィルム：Ｇ２−５０、表面張力５０ｄｙｎｅ／ｃｍ）上に塗布し、１４０℃で５分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１）を作製した。
この接着シート１を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３６０ＭＰａ、２６０℃で３０ＭＰａであった。
（製造例２）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）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−オン（Ｃｉｂａ Ｓｐｅｃｉａｌｉｔｙ Ｃｈｅｍｉｃａｌｓ社製、商品名：イルガキュア３６９）にした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２）を作製した。
この接着シート２を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３５０ＭＰａ、２６０℃で２５ＭＰａであった。
（製造例３）
デナコール ＥＸ−４１１（ナガセケムテックス（株）製商品名、脂肪族エポキシ樹脂、４官能、エポキシ当量２３１）７６．０重量部、フェノライトＬＦ２８８２（大日本インキ化学工業（株）製商品名、ビスフェノールＡノボラック樹脂）３９．０重量部、ＨＴＲ−８６０Ｐ−３）ナガセケムテックス（株）製商品名、エポキシ基含有アクリルゴム、分子量１００万、Ｔｇ−７℃）７６．７重量部、キュアゾール２ＰＺ−ＣＮ（四国化成工業（株）製商品名、１−シアノエチル−２−フェニルイミダゾール）０．５重量部、ＮＵＣ Ａ−１８７（日本ユニカー（株）製商品名、γ−グリシドキシプロピルトリメトキシシラン）０．７重量部、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、商品名：イルガキュア３６９）１．０重量部からなる組成物に、メチルエチルケトンを加えて攪拌混合し、真空脱気した。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人デュポンフィルム（株）製、テイジンテトロンフィルム：Ｇ２−５０、表面張力５０ｄｙｎｅ／ｃｍ）上に塗布し、１４０℃で５分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート３）を作製した。
この接着シート３を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３６０ＭＰａ、２６０℃で１０ＭＰａであった。
（製造例４）
エピコート８２８（ジャパンエポキシレジン（株）製商品名、ビスフェノールＡ型エポキシ樹脂、エポキシ当量１９０）４５．０重量部、ＥＳＣＮ１９５（住友化学工業（株）商品名、ｏ−クレゾールノボラック型エポキシ樹脂、エポキシ当量１９５）１５．０重量部、プライオーフェンＬＦ２８８２（大日本インキ化学工業（株）製商品名、ビスフェノールＡノボラック樹脂）４０．０重量部、ＨＴＲ−８６０Ｐ−３（ナガセケムテックス（株）製商品名、エポキシ基含有アクリルゴム、分子量１００万、Ｔｇ−７℃）６６．７重量部、キュアゾール２ＰＺ−ＣＮ（四国化成工業（株）製商品名、１−シアノエチル−２−フェニルイミダゾール）０．５重量部、ＮＵＣ Ａ−１８７（日本ユニカー（株）製商品名、γ−グリシドキシプロピルトリメトキシシラン）０．７重量部、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、商品名：イルガキュア３６９）１．０重量部からなる組成物に、メチルエチルケトンを加えて攪拌混合し、真空脱気した。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人デュポンフィルム（株）製、テイジンテトロンフィルム：Ｇ２−５０、表面張力５０ｄｙｎｅ／ｃｍ）上に塗布し、１４０℃で５分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート３）を作製した。
この接着シート４を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３６０ＭＰａ、２６０℃で１４ＭＰａであった。
（製造例５）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をアミンイミド化合物（ＰＢ−２）にした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート５）を作製した。
この接着シート５を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３５０ＭＰａ、２６０℃で３５ＭＰａであった。
（製造例６）
製造例１において、ベンゾフェノン ０．１重量部を添加した以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート６）を作製した。
この接着シート６を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３５０ＭＰａ、２６０℃で３５ＭＰａであった。
（製造例７）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をアミンイミド化合物（ＰＢ−３）にした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート７）を作製した。
この接着シート７を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３５０ＭＰａ、２６０℃で３５ＭＰａであった。
（製造例８）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をイミダゾリウムテトラフェニルほう酸塩（ＰＢ−４）にした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート８）を作製した。
この接着シート８を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３４０ＭＰａ、２６０℃で３０ＭＰａであった。
（製造例９）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をイミダゾリウムテトラフェニルほう酸塩（ＰＢ−５）にした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート９）を作製した。
この接着シート９を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３６０ＭＰａ、２６０℃で３５ＭＰａであった。
（製造例１０）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）を０．００５重量部とした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１０）を作製した。
この接着シート１０を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３８０ＭＰａ、２６０℃で３０ＭＰａであった。
（製造例１１）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）を１５０．０重量部とした以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１１）を作製した。
この接着シート１１を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３０ＭＰａ、２６０℃で１ＭＰａであった。
（製造例１２）
製造例１において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）を除いた以外は製造例１と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１２）を作製した。
この接着シート１２を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で３８０ＭＰａ、２６０℃で３０ＭＰａであった。
（製造例１３）
ＹＤＣＮ−７０３（東都化成（株）製商品名、ｏ−クレゾールノボラック型エポキシ樹脂、エポキシ当量２１０）４２．３質量部、フェノライトＬＦ２８８２（大日本インキ化学工業（株）製商品名、ビスフェノールＡノボラック樹脂）２３．９質量部、ＨＴＲ−８６０Ｐ−３）ナガセケムテックス（株）製商品名、エポキシ基含有アクリルゴム、分子量１００万、Ｔｇ−７℃）４４．１質量部、キュアゾール２ＰＺ−ＣＮ（四国化成工業（株）製商品名、１−シアノエチル−２−フェニルイミダゾール）０．４質量部、ＮＵＣ Ａ−１８７（日本ユニカー（株）製商品名、γ−グリシドキシプロピルトリメトキシシラン）０．７質量部、４Ｇ（新中村化学（株）製商品名、テトラエチレングリコールジメタクリレート）２２．０５質量部及び１−ヒドロキシシクロヘキシルフェニルケトン ０．５質量部からなる組成物に、メチルエチルケトンを加えて攪拌混合し、真空脱気した。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレートフィルム上に塗布し、１４０℃で５分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１３）を作製した。
この接着シート１３を１７０℃１時間硬化させた場合の貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）した結果、２５℃で４００ＭＰａ、２６０℃で５０ＭＰａであった。
（製造例１４）
製造例６で得られたポリイミド樹脂（ＰＩ−１）５０重量部、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）１０重量部、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）０．２重量部、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（ＰＢ−１）０．２重量部を、溶剤であるＮ−メチル−２−ピロリドン２００重量部中に加えて溶解させる。これを良く攪拌し、均一に分散させて接着剤ワニスを得た。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人デュポンフィルム（株）製、テイジンテトロンフィルム：Ｇ２−５０、表面張力５０ｄｙｎｅ／ｃｍ）上に塗布し、１５０℃で２０分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１４）を作製した。
（製造例１５）
製造例１４において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）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−オン（Ｃｉｂａ Ｓｐｅｃｉａｌｉｔｙ Ｃｈｅｍｉｃａｌｓ社製、商品名：イルガキュア３６９）にした以外は製造例１４と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１５）を作製した。
（製造例１６）
製造例１４において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をアミンイミド化合物（ＰＢ−２）にした以外は製造例１４と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１６）を作製した。
（製造例１７）
製造例１６において、ベンゾフェノン０．０５重量部を加えて以外は製造例１６と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１７）を作製した。
（製造例１８）
製造例１４において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をアミンイミド化合物（ＰＢ−３）にした以外は製造例１４と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１８）を作製した。
（製造例１９）
製造例１４において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をイミダゾリウムテトラフェニルほう酸塩（ＰＢ−４）にした以外は製造例１４と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート１９）を作製した。
（製造例２０）
製造例１４において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）をイミダゾリウムテトラフェニルほう酸塩（ＰＢ−５）にした以外は製造例１４と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２０）を作製した。
（製造例２１）
製造例７で得られたポリイミド樹脂（ＰＩ−２）５０重量部、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）１３重量部、フェノールノボラック樹脂（明和化成（株）製、商品名：Ｈ−１）６．９重量部、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）０．１３重量部、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、商品名：イルガキュア３６９）４．０重量部を、溶剤であるＮ−メチル−２−ピロリドン２００重量部中に加えて溶解させる。これを良く攪拌し、均一に分散させて接着剤ワニスを得た。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人デュポンフィルム（株）製、テイジンテトロンフィルム：Ｇ２−５０、表面張力５０ｄｙｎｅ／ｃｍ）上に塗布し、１５０℃で２０分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２１）を作製した。
（製造例２２）
製造例１５において、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、商品名：イルガキュア３６９）を０．００４重量部にした以外は製造例１５と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２２）を作製した。
（製造例２３）
製造例１５において、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、商品名：イルガキュア３６９）を１２０．０重量部にした以外は製造例１５と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２３）を作製した。
（製造例２４）
製造例１４において、２−ニトロベンジルカルバミン酸誘導体（ＰＢ−１）を除いた以外は製造例１４と全く同様の操作を行い、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２４）を作製した。
（製造例２５）
製造例８で得られたポリイミド樹脂（ＰＩ−３）５０重量部、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）１３重量部、フェノールノボラック樹脂（明和化成（株）製、商品名：Ｈ−１）６．９重量部、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）０．１３重量部を、溶剤であるＮ−メチル−２−ピロリドン２００重量部中に加えて溶解させる。これを良く攪拌し、均一に分散させて接着剤ワニスを得た。この接着剤ワニスを、厚さ５０μｍのポリエチレンテレフタレート（帝人デュポンフィルム（株）製、テイジンテトロンフィルム：Ｇ２−５０、表面張力５０ｄｙｎｅ／ｃｍ）上に塗布し、１５０℃で２０分間加熱乾燥して、基材（ポリエチレンテレフタレートフィルム）を備えた膜厚が５０μｍの接着シート（基材を除いた接着シートの厚みが５０μｍ）（接着シート２５）を作製した。
製造例１〜２５で作製した接着シート１〜２５について、以下の実施例１〜４５及び比較例１〜１１に示すように評価を行った。
（実施例１〜１１）
製造例１〜１１で得られた接着シート１〜１１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）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確率（％／１００チップ）で示した。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確率（％／１００チップ）で示した。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ーテスト：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。剥離の発生していない確率（％／１００チップ）で示した。
一方、接着シート１〜１１を厚さ１５０μｍのシリコンウェハ上に貼付け、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／ｃｍ２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。ダイシング時にチップが飛んだ確率（％／１００チップ）でダイシング時のチップ飛びを、ピックアップダイボンダーにより、ダイシング後のチップをピックアップしたときのピックアップできた確率（％／１００チップ）でピックアップ性を示した。
さらに、上記接着シート付きシリコンウェハに５００ｍＪ／ｃｍ２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 ５０ｍｍ／ｍｉｎ）。これらの評価結果をまとめて表４に示す。
（比較例１〜２）
製造例１２及び１３で得られた接着シート１２及び１３を実施例１と同様の条件で評価した。結果を表４に示す。
（実施例１２〜２１）
製造例１４〜２３で得られた接着シート１４〜２３を実施例と１と同様の条件で評価した。結果を表５に示す。
（比較例３〜４）
製造例２４及び２５で得られた接着シート２４及び２５を実施例と１と同様の条件で評価した。結果を表５に示す。

表４及び表５から、本発明の接着シートは耐熱性及び耐湿性に優れ、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ことが分かった。さらに、露光前後の接着強度差が大きいため、作業条件裕度が大きく、作業性に優れるものであることが分かった。
（実施例２２）
製造例１で作製した接着シート１の放射線照射前後のタック強度、フロー量及び溶融粘度を下記条件で測定した。前述した表４及び表５の評価結果と併せて表６に示す。
（１０）’タック強度
上記接着シート１の粘接着剤層のタック強度を、ＲＨＥＳＣＡ社製タッキング試験機を用いて、ＪＩＳＺ０２３７−１９９１に記載の方法で２５℃で測定した。測定条件は、プローブ径５．１ｍｍφ、引き剥がし速度１０ｍｍ／ｓ、接触荷重９．８１×１０^３Ｐａ（１００ｇｆ／ｃｍ^２）、接触時間１ｓで行った。
（２）’フロー量
上記接着シート１を１０×２０ｍｍの大きさに切断し、接着シートの粘接着剤層側が密着するようにスライドガラス上に置き、熱圧着試験装置（テスター産業（株）製）を用いて、１６０℃、０．８ＭＰａで１８秒間加圧し、４個のサンプルについて２０ｍｍの長片の端部から、初期の大きさより周辺にはみ出した最も長い距離を光学顕微鏡で各サンプルについて２点、計８点測定し、その平均値からなるフロー量を測定した
（３）’溶融粘度
上記接着シート１の粘接着剤層を８枚ラミネートし、厚さ約４００μｍのフィルムを作製した後、これを直径１１．３ｍｍの円形に打ち抜いたものを試料とし、１６０℃において、荷重２４．５Ｎ（２．５ｋｇｆ）で５秒間加圧し、平行平板プラスとメータ法によって測定し、下式によって溶融粘度（η）を算出した。

（式中、Ｚ０は荷重を加える前の接着フィルムの厚さ、Ｚは荷重を加えて後の接着フィルムの厚さ、Ｖは接着フィルムの体積、Ｆは加えた荷重、ｔは荷重を加えた時間を表す）
（実施例２３〜２５）
製造例２〜４で作製した接着シート２〜４の放射線照射前後のタック強度、フロー量及び溶融粘度を実施例２２と同様の条件で測定した。結果を表６に示す。
（実施例２６〜２９）
製造例１４〜１７で作製した接着シート１４〜１７の放射線照射前後のタック強度、フロー量及び溶融粘度を実施例２２と同様の条件で測定した。結果を表６に示す。
（比較例５〜６）
製造例１２及び２５で作製した接着シート１２及び２５の放射線照射前後のタック強度、フロー量及び溶融粘度を実施例２２と同様の条件で測定した。結果を表６に示す。

表６から、本発明の接着シートは、露光前のウエハとの密着性が優れているため、ダイシング時にチップ飛びを起こさないことが分かった。
また、本発明の接着シートは、放射線照射後の半導体チップ界面との接着強度低下が大きいため、ピックアップ性に優れることが分かった。
また、本発明の接着シートは、放射線照射前後のフィルム流動性低下が少ないため、耐熱性、耐湿性等の信頼性に優れることが分かった。
（実施例３０）
製造例１で作製した接着シート１に（株）オーク製作所製ＵＶ−３３０ ＨＱＰ−２型露光機を使用して、５００ｍＪ／ｃｍ２の露光量で接着シートの基材フィルム側から露光し、実施例２２と同様にして放射線照射後のタック強度を測定した。
また、接着シート１に上記と同様に露光し、放射線照射前後のｔａｎδ及び貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４、自動静荷重）を用いて、次の条件で測定した。表４及び表５に示した信頼性評価結果と併せて表７に示す。
サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ
昇温速度：５℃／ｍｉｎ、
測定モード：引張りモード、
周波数：１０Ｈｚ
（実施例３１〜３３）
製造例２〜４で作製した接着シート２〜４の放射線照射前後のタック強度、ｔａｎδ及び貯蔵弾性率を実施例３０と同様の条件で測定した。表４及び表５に示した信頼性評価結果と併せて表７に示す。
（実施例３４〜３７）
製造例１４〜１６及び２１で作製した接着シート１４〜１６及び２１の放射線照射前後のタック強度、ｔａｎδ及び貯蔵弾性率を実施例３０と同様の条件で測定した。表４及び表５に示した信頼性評価結果と併せて表７に示す。
（比較例７〜９）
製造例１２、１３及び２５で作製した接着シート１２，１３及び２５の放射線照射前後のタック強度、ｔａｎδ及び貯蔵弾性率を実施例３０と同様の条件で測定した。表４及び表５に示した信頼性評価結果と併せて表７に示す。

表７から、本発明の接着シートは、放射線照射後に基材フィルムとの粘着性が十分に低下するため、ピックアップ性に優れることが分かった。さらに放射線照射後でもその流動性の低下が少ないことから、耐熱性、耐湿性等の信頼性に優れることが分かった。
（実施例３８）
製造例１で作製した接着シート１に（株）オーク製作所製ＵＶ−３３０ ＨＱＰ−２型露光機を使用して、５００ｍＪ／ｃｍ２の露光量で接着シートの基材フィルム側から露光し、実施例３０と同様の装置を用いて、放射線照射前後の貯蔵弾性率を測定した。また、１７０℃で１時間硬化させた粘接着層の貯蔵弾性率も同様に測定した。一方、放射線照射後のフロー量及び溶融粘度を実施例２２と同様の条件で測定した。さらに、半導体チップ（５ｍｍ×５ｍｍ×４００μｍ厚）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放射線照射後の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）を作製し、図３に示したような自動接着力試験機（日立化成テクノプラント（株）製）を使用して、２５０℃での接着強度を測定した。表２に示した結果と併せて表８に示す。
（実施例３９〜４５）
製造例２〜４及び１４〜１７で作製した接着シート２〜４及び１４〜１７の放射線照射前後の貯蔵弾性率、１７０℃で１時間硬化させた粘接着層の貯蔵弾性率、放射線照射後のフロー量、溶融粘度及び２５０℃での接着強度を実施例３８と同様の条件で測定した。表４及び表５に示した結果と併せて表８に示す。
（比較例１０，１１）
製造例１２及び１３で作製した接着シート１２及び１３放射線照射前後の貯蔵弾性率、１７０℃で１時間硬化させた粘接着層の貯蔵弾性率、放射線照射後のフロー量、溶融粘度及び２５０℃での接着強度を実施例３８と同様の条件で測定した。表４及び表５に示した結果と併せて表８に示す。

表８から、本発明の接着シートは、放射線照射前後でフィルム流動性の低下が少ないため、耐熱性、耐湿性等の信頼性に優れることが分かった。また放射線照射前後の貯蔵弾性率差が大きいため、ダイシング時にチップ飛びが無く、ピックアップ性にも優れるものであることが分かった。
＜評価方法＞
（１）貯蔵弾性率
接着シートの貯蔵弾性率を動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４）を用いて測定した（サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ、昇温速度５℃／ｍｉｎ、引張りモード、１０Ｈｚ、自動静荷重）。
（２）フロー量の測定
粘接着剤層と基材層（ＰＥＴフィルム（帝人デュポンフィルム（株）製テイジンテトロンフィルムＧ２−５０））とを備える厚さ（基材層を除いた接着シートの厚さ）５０μｍの接着シートから１×２ｃｍの短冊片を打ち抜くことにより、寸法１×２ｃｍの短冊状サンプルＳを調製した。そして、熱圧着試験装置（テスター産業株式会社製）において、前記短冊状サンプルＳを１６０℃に加熱したステージ上に置き、０．８ＭＰａの圧力を１８秒間付与した。その後、前記サンプルＳを熱圧着試験装置から取出した後、図１２に示されるように前記サンプルＳの長片（２ｃｍ辺）の端部からはみだした樹脂のうち、図中５５、５６で示されるように１番目と２番目に長いはみ出し距離（長手方向距離ａ）を光学顕微鏡で測定した。このような操作を４つのサンプルについて行いそれらのはみ出し距離の平均値、即ち合計８点の距離の平均値を求めフロー量とした。
（３）溶融粘度
接着シートの溶融粘度は平行平板プラストメータ法により測定、算出した値を用いた。接着シートを８枚ラミネートし、厚さ約４００μｍのフィルムを作製する。これを直径１１．３ｍｍの円形に打ち抜いたものを試料とし、１６０℃において、荷重２．５ｋｇｆで５秒間加圧し、加圧前後の試料の厚みから、式１を用いて溶融粘度を算出した。

（式中、Ｚ０は荷重を加える前の接着シートの厚さ、Ｚは荷重を加えた後の接着シートの厚さ、Ｖは接着シートの体積、Ｆは加えた荷重、ｔは荷重を加えた時間を表す。）
（４）対金めっきピール強度（接着強度）
１２０℃のホットプレート上で接着シートにチップ（５ｍｍ角）及び金めっき基板（銅箔付フレキ基板電解金めっき（Ｎｉ：５μｍ、Ａｕ：０．３μｍ））を積層し、１３０℃３０ｍｉｎ＋１７０℃１ｈキュアした。この試料のついて常態と吸湿後（８５／８５、４８ｈ）の２５０℃でのピール強度を測定した。
（５）耐リフロークラック性と耐温度サイクル性（試験）
（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た接着シートを用いて、半導体素子及び接着シートと厚み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）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耐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、ＪＥＤＥＣ規格であるＪ−ＳＴＤ−０２０Ａに準拠し、レベル２に相当する吸湿処理（８５℃、８５％ＲＨ、１６８時間）を行った半導体装置サンプルについて、サンプル表面の最高温度が２６５℃で、２６０℃以上を１０〜２０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。
（６）耐湿性評価
温度１２１℃、湿度１００％、２．０３×１０^５Ｐａの雰囲気（プレッシャークッカーテスト：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。
（７）ダイシング時のチップ飛び及びピックアップ性
接着シートを厚さ１５０μｍのシリコンウェハ上に貼付け、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、２０００ｍＪ／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半導体素子をピックアップし、ダイシング時の半導体素子飛び及びピックアップ性を評価した。ピックアップダイボンダーにより、ダイシング後の半導体素子をピックアップしたときのピックアップできた確率（％／１００半導体素子）を示した。
（８）貯蔵弾性率、ｔａｎδ
粘接着剤層の貯蔵弾性率及びｔａｎδを動的粘弾性測定装置（レオロジ社製、ＤＶＥ−Ｖ４、自動静荷重）を用いて、次の条件で測定した。
サンプルサイズ：長さ２０ｍｍ、幅４ｍｍ、膜厚８０μｍ
昇温速度：５℃／ｍｉｎ、測定モード：引張りモード、周波数：１０Ｈｚ
（９）９０°ピール剥離力（接着強度）
接着シートを、粘接着剤層を挟んで半導体ウェハ上に１２０℃でラミネートし、この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を基材側から露光し、露光前後の粘接着剤層／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）。
（１０）タック強度
ＲＨＥＳＣＡ社製タッキング試験機を用いて、ＪＩＳＺ０２３７−１９９１に記載の方法により、次の測定条件で、２５℃におけるタック強度を測定した。
プローブ径：５．１ｍｍΦ、引き剥がし速度：１０ｍｍ／ｓ、接触荷重：１００ｇｆ／ｃｍ^２、接触時間：１ｓ
（１１）耐熱性及び耐湿性評価
（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た接着シートを用いて、半導体素子及び接着シートと厚み２５μｍのポリイミドフィルムを基材に用いた配線基板を１８０℃、０．４Ｎ、５秒の条件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）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耐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、ＪＥＤＥＣ規格であるＪ−ＳＴＤ−０２０Ａに準拠し、レベル２に相当する吸湿処理（８５℃、８５％ＲＨ、１６８時間）を行った半導体装置サンプルについて、サンプル表面の最高温度が２６５℃で、２６０℃以上を１０〜２０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及び剥離を目視と超音波顕微鏡で視察した。クラック及び剥離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％、２．０．３×１０^５Ｐａ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。
（１２）使用熱可塑性樹脂のＴｇ
示唆走査熱量計（ＤＳＣ）により、昇温速度１０℃／分の条件で使用熱可塑性樹脂のＴｇを求めた。
（１３）使用熱可塑性樹脂の重量平均分子量
ゲルパーミュエーションクロマトグラフィーを用いて測定し、標準ポリスチレン検量線を用いて換算した。
（１４）ＤＳＣによる発熱量の変化率
本接着シートにおいて、放射線を照射したときの粘接着剤層のＤＳＣによる発熱量をＡ、放射線照射前の発熱量をＢとしたときの変化率（反応率）を、式：（Ｂ−Ａ）／Ｂにより算出した。なお、ＤＳＣ測定条件は以下の通りである。
昇温速度：１０℃／分、測定温度：２０℃〜３００℃
（１５）９０°ピール剥離力
接着シートを厚さ１５０μｍのシリコンウェハ上に貼付けて得られた、接着シート付きシリコンウェハに、５００ｍＪ／ｃｍ^２の露光量で基材フィルム側から露光し、露光前後の粘接着剤層／基材界面の接着強度を、９０°ピール剥離力で測定した（引張り速度：５０ｍｍ／ｍｉｎ）。
本出願は、同出願人により先にされた日本国特許出願、すなわち、特願２００１−２５６２８５号（出願日２００１年８月２７日）、特願２００１−２５６２８６号（出願日２００１年８月２７日）、特願２００１−２６２６６２号（出願日２００１年８月３１日）、特願２００１−２６９０１３号（出願日２００１年９月５日）、特願２００２−３５４８８号（出願日２００２年２月１３日）、特願２００２−３７０３２号（出願日２００２年２月１４日）、特願２００２−７６５７７号（出願日２００２年３月１９日）、特願２００２−８３７７７号（出願日２００２年３月２５日）、特願２００２−８３８１８号（出願日２００２年３月２５日）、特願２００２−８３８４４号（出願日２００２年３月２５日）、特願２００２−１３７２５２号（出願日２００２年５月１３日）に基づく優先権主張を伴うものであって、これらの明細書を参照のためにここに組み込むものとする。
産業上の利用可能性
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、半導体素子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、半導体素子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、耐湿性及び作業性を兼ね備えるものである。
【図面の簡単な説明】
Ｆｉｇ．１
本発明に係る接着シートの一例の断面図である。
Ｆｉｇ．２
本発明に係る接着シートの別の例の断面図である。
Ｆｉｇ．３
本発明に係る接着シートに半導体ウェハを貼着した状態を示す図である。
Ｆｉｇ．４
本発明に係る接着シートを半導体ウェハのダイシング工程に用いた場合の説明図である。
Ｆｉｇ．５
図４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である。
Ｆｉｇ．６
図５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である。
Ｆｉｇ．７
ピックアップされた半導体素子と粘接着剤層を示す図である。
Ｆｉｇ．８
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図である。
Ｆｉｇ．９
合成例４で得たイミダゾリウムテトラフェニルほう酸塩の^１Ｈ−ＮＭＲチャートである。
Ｆｉｇ．１０
合成例５で得たイミダゾリウムテトラフェニルほう酸塩の^１Ｈ−ＮＭＲチャートである。
Ｆｉｇ．１１
自動接着力試験機の模式図である。
Ｆｉｇ．１２
はみ出し距離の測定方法を示す図である。
符号の説明
１…基材フィルム
２…第１の粘接着剤層
３…第２の粘接着剤層
４…吸引コレット
５…半導体素子搭載用支持部材
１０、１１…接着シート
Ａ…半導体ウェハ
Ａ１、Ａ２、Ａ３…半導体素子
Ｂ…放射線
２１…半導体チップ
２２…接着シート
２３…配線基板
３１…作用部
３２…本体
４０…止め部
４１…熱版
Ｃ…自動接着力試験機
Ｄ…半導体装置サンプル
５０…矢印
Ｓ…試験片Technical field
The present invention relates to an adhesive sheet, a semiconductor device using the same, and a method for manufacturing the same.
Background art
Conventionally, 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 elements, the supporting members used have also been required to be miniaturized and miniaturized. In response to such demands, silver paste satisfies the above-mentioned requirements due to the occurrence of defects during wire bonding due to protrusion or inclination of the semiconductor element, difficulty in controlling the thickness of the adhesive layer, and generation of voids in the adhesive layer. It is becoming impossible to cope.
Therefore, in order to meet the above demand, a film-like adhesive has recently been used.
This film adhesive is used in an individual piece bonding method or a wafer backside bonding method. In the case of manufacturing a semiconductor device using the former individual-part film-type adhesive, the reel-like adhesive film is cut into individual pieces by cutting or punching, and then the individual pieces are bonded to a supporting member; The semiconductor element singulated by the dicing step is joined to the support member with the adhesive to produce a support member with a semiconductor element; and then, if necessary, a wire bonding step, a sealing step, and the like are performed to obtain a semiconductor device. Will be done. However, in order to use the film-like adhesive of the individual piece sticking method, a special assembling apparatus for cutting out the adhesive film and bonding the adhesive film to the supporting member is required. There was a problem that becomes high.
On the other hand, in the case of manufacturing a semiconductor device using the latter film-like adhesive of the wafer backside sticking method, first, a film-like adhesive is stuck on the backside of the semiconductor wafer, and then a dicing tape is stuck on the other surface of the film-like adhesive; Thereafter, the semiconductor elements are diced from the wafer by dicing; the singulated semiconductor elements with a film-like adhesive are picked up and bonded to a support member; and then subjected to steps such as heating, curing, and wire bonding. A semiconductor device is obtained. This film adhesive of the wafer backside bonding method does not require a device for dividing the film adhesive into individual pieces in order to join the semiconductor element with the film adhesive to the support member, and requires a conventional assembly device for silver paste. It can be used as it is or by improving a part of the apparatus such as adding a hot plate. For this reason, attention has been paid to a method of relatively low production cost among the assembling methods using a film adhesive.
The dicing tape used together with the film adhesive of the wafer backside sticking type is roughly classified into a pressure-sensitive type and a UV type dicing tape.
The former pressure-sensitive type dicing tape is usually obtained by applying an adhesive to a polyvinyl chloride or polyolefin base film. This dicing tape is required to have sufficient adhesive strength so that each element is not scattered by rotation by the dicing saw during cutting in the dicing step, and to prevent the adhesive from adhering to each element and not to damage the elements during pickup. Therefore, a low adhesive strength that can be picked up is required. However, there has been no pressure-sensitive dicing tape having the two opposing performances as described above. Therefore, the work of switching the dicing tape for each size and processing condition of the semiconductor element has been performed. Further, since various kinds of dicing tapes having various adhesive strengths corresponding to element sizes and processing conditions are required, inventory management of dicing tapes has been complicated. Furthermore, in recent years, semiconductor devices have tended to increase in size as a result of the increase in the capacity of CPUs and memories, and thinner memories have been used in products such as IC cards and memory cards. . As these semiconductor elements become larger and thinner, the pressure-sensitive dicing tape has a high adhesive strength at the time of pickup, and thus causes problems such as cracking of the element at the time of pickup, and a fixing force (high adhesion) at the time of dicing. Force) and the peeling force (low adhesive force) at the time of pickup cannot be satisfied.
On the other hand, the latter UV dicing tape has a high adhesive strength at the time of dicing, but has a low adhesive strength by irradiating with ultraviolet rays (UV) before picking up. For this reason, the problem of the pressure-sensitive tape has been improved, and the tape has been widely used as a dicing tape.
The problem of the pressure-sensitive dicing tape can be improved to some extent by using this UV-type dicing tape, but it is not sufficient. Further, there is a problem to be further improved in the film-like adhesive of the backside affixing type. That is, in the method using the film-like adhesive of the wafer backside sticking method, two attaching steps such as attaching the film-like adhesive and the dicing tape were required before the dicing step. Further, there has been a problem that the pressure-sensitive adhesive of the dicing tape is transferred to the film-like adhesive, and the adhesiveness is reduced. For this reason, an adhesive sheet having both functions of a film adhesive and a dicing tape is required.However, the semiconductor element has a sufficient adhesive strength so that the semiconductor elements are not scattered at the time of dicing, and has a low adhesive strength which does not damage each element at the time of pickup. An adhesive sheet that satisfies the conflicting demands of having power has not been obtained.
As described above, there has been a demand for an adhesive sheet that functions as a dicing tape in the dicing step and that functions as an adhesive sheet having excellent connection reliability in the bonding step between the semiconductor element and the support member. Further, there has been a demand for an adhesive sheet having heat resistance and moisture resistance required when a semiconductor element having a large difference in thermal expansion coefficient is mounted on a semiconductor element mounting support member, and having excellent workability. Further, there has been a demand for a method of manufacturing a semiconductor device capable of simplifying a manufacturing process.
Disclosure of the invention
Then, the present inventors have studied from the viewpoint of the composition of the adhesive sheet, and as a result, have found that an adhesive sheet provided with an adhesive layer containing a predetermined component solves the above-mentioned problems. In addition, the inventors of the present invention have studied characteristics and chemistry in order to improve the workability and reliability of the adhesive sheet. As a result, the workability and reliability can be further improved by the adhesive sheet having predetermined characteristics. Was found.
That is, the present invention relates to an adhesive sheet provided with an adhesive layer containing a predetermined component.
<1> An adhesive sheet comprising an adhesive layer and a base material layer, wherein the adhesive force between the adhesive layer and the base material layer is controlled by irradiation of radiation. The adhesive layer is an adhesive sheet containing the following components.
(A) a thermoplastic resin,
(B) a thermopolymerizable component, and
(C) Compound that generates a base upon irradiation
The invention also relates to an adhesive sheet having the following parameters.
<2> The adhesive layer has (A1) an adhesive strength of 200 mN / cm or more at an interface between the adhesive layer and the base material layer before irradiation, or (A2) an adhesive before irradiation. The adhesive sheet, wherein the tacky adhesive layer has a tack strength of 0.5 N or more at 25 ° C. measured by a 5.1 mmφ probe and has at least one of the following characteristics.
(B1) a flow amount at 160 ° C. before irradiation is 100 to 10,000 μm;
(B2) melt viscosity at 160 ° C. before irradiation is 50 to 100000 Pa · s
Furthermore, the present invention relates to an adhesive sheet having the following parameters.
<3> An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation with radiation. The adhesive layer has (A2) a tack strength at 25 ° C. of 0.5 N or more measured by a 5.1 mmφ probe measurement of the adhesive layer before irradiation with radiation, and at least one of the following characteristics. An adhesive sheet provided.
(B1) a flow amount at 160 ° C. before irradiation is 100 to 10,000 μm;
(B2) melt viscosity at 160 ° C. before irradiation is 50 to 100000 Pa · s
<4> An adhesive sheet comprising an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive layer has (C1) an adhesive strength difference (adhesive strength before irradiation-adhesive strength after irradiation) of 100 mN / cm or more at the interface between the adhesive layer and the base material layer before and after irradiation, and An adhesive sheet having at least one of the following properties.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less.
<5> An adhesive sheet comprising an adhesive layer and a base material layer, wherein the adhesive force between the adhesive layer and the base material layer is controlled by irradiation of radiation. The adhesive layer had a (C2) difference in tack strength of the adhesive layer before and after irradiation at 25 ° C. (tack strength at 25 ° C. before irradiation—tack strength at 25 ° C. after irradiation) of 0.1 N. /5.1 An adhesive sheet having a diameter of at least one probe and having at least one of the following characteristics.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less.
With the above configuration, the adhesive sheet of the present invention has a sufficient adhesive force so that the semiconductor element does not scatter at the time of dicing, and then irradiates radiation to cause the adhesive sheet and the base material to adhere to each other. By controlling the adhesive strength of the above, the conflicting demands of having a low adhesive strength without damaging each element at the time of pickup are satisfied. Therefore, by manufacturing an electronic component using the adhesive sheet of the present invention, it is possible to obtain an operational effect that dicing and die bonding steps can be completed with a single film.
BEST MODE FOR CARRYING OUT THE INVENTION
<Base layer>
The component constituting the base material layer used in the adhesive sheet of the present invention is not particularly limited as long as it transmits radiation, and can be appropriately selected according to the use process and the like (for example, whether or not to expand at the time of pickup). . Specifically, for example, a polyester-based film such as a polyethylene terephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polymethylpentene film, a polyolefin-based film such as a polyvinyl acetate film, a polyvinyl chloride film, a polyimide film And the like.
Further, the base layer may be a laminate of two or more different films. In this case, the film on the side in contact with the adhesive layer has a tensile elastic modulus at 25 ° C. of preferably 2000 MPa or more, more preferably 2200 MPa or more, in that the workability of picking up the semiconductor element is improved. It is particularly preferable that the pressure be 2400 MPa or more.
In addition, the other substrate film on the side not directly in contact with the adhesive layer has a large elongation of the film and a good workability in the expanding step, and has a tensile modulus at 25 ° C. of 1000 MPa or less. Is preferably 800 MPa or less, more preferably 600 MPa or less. This tensile modulus is measured according to JIS K7113.
When using a substrate layer obtained by laminating two or more types of substrate films, the lamination method is not particularly limited, and a method of laminating separately prepared substrate films, a method of laminating one substrate film on another substrate film, Extruding and laminating material films, extruding and laminating two or more types of base films, and dissolving or dispersing a polymer as a raw material of a base film in a solvent to form a varnish on another base film A known method such as a method of applying and heating to remove the solvent and a method of bonding using an adhesive can be used.
<Adhesive layer>
As the adhesive layer used in the adhesive sheet of the present invention, for example, an adhesive layer containing a thermoplastic resin, a thermopolymerizable component, and a compound that generates a base upon irradiation with radiation is preferable. With such a configuration, the semiconductor element has a sufficient adhesive force so that the semiconductor element does not scatter during dicing, and thereafter, is irradiated with radiation to control the adhesive force between the adhesive layer and the base material. Therefore, it is possible to satisfy the conflicting demands of having a low adhesive strength so as not to damage each element at the time of pickup.
(Thermopolymerizable component)
Further, the thermopolymerizable component is not particularly limited as long as it is polymerized by heat, for example, glycidyl group, acryloyl group, methacryloyl group, hydroxyl group, carboxyl group, isocyanurate group, amino group, amide group and the like Compounds having a functional group can be used, and these can be used alone or in combination of two or more kinds. However, in consideration of heat resistance as an adhesive sheet, thermosetting that exerts an adhesive action by heat is applied. It is preferable to use a conductive resin. Examples of the thermosetting resin include an epoxy resin, an acrylic resin, a silicone resin, a phenol resin, a thermosetting polyimide resin, a polyurethane resin, a melamine resin, and a urea resin, and in particular, heat resistance, workability, and reliability. It is most preferable to use an epoxy resin from the viewpoint that an adhesive sheet having excellent resistance can be obtained. When an epoxy resin is used as the thermosetting resin, it is preferable to use an epoxy resin curing agent in combination.
(Epoxy resin)
The epoxy resin is not particularly limited as long as it is cured and has an adhesive action. Bifunctional epoxy resins such as bisphenol A type epoxy, and novolak type epoxy resins such as phenol novolak type epoxy resin and cresol novolak type epoxy resin can be used. In addition, generally known ones such as a polyfunctional epoxy resin, a glycidylamine type epoxy resin, a heterocyclic epoxy resin, and an alicyclic epoxy resin can be used.
Bisphenol A type epoxy resins include Epicoat series (Epicoat 807, Epicoat 815, Epicoat 825, Epicoat 827, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004, Epicoat 1007, Epicoat 1009) manufactured by Japan Epoxy Resin Co., Ltd., Dow. DER-330, DER-301 and DER-361 manufactured by Chemical Co., Ltd., and YD8125 and YDF8170 manufactured by Toto Kasei Co., Ltd. Examples of the phenol novolak type epoxy resin include Epicoat 152 and Epicoat 154 manufactured by Japan Epoxy Resin Co., Ltd., EPPN-201 manufactured by Nippon Kayaku Co., Ltd., DEN-438 manufactured by Dow Chemical Company, and the like, and o-cresol novolak. Examples of the type epoxy resin include EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1012, EOCN-1025, and EOCN-1027 manufactured by Nippon Kayaku Co., Ltd., and YDCN701 and YDCN702 manufactured by Toto Kasei Co., Ltd. YDCN703, YDCN704, etc. are mentioned. Examples of the polyfunctional epoxy resin include Epon 1031S manufactured by Japan Epoxy Resin Co., Ltd., Araldite 0163 manufactured by Ciba Specialty Chemicals, and Denacol EX-611, EX-614, EX-614B, EX manufactured by Nagase ChemteX Corporation. -622, EX-512, EX-521, EX-421, EX-411, EX-321 and the like. Examples of the amine type epoxy resin include Epicoat 604 manufactured by Japan Epoxy Resin Co., Ltd., YH-434 manufactured by Toto Kasei Co., Ltd., TETRAD-X and TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd., and Sumitomo Chemical Co., Ltd. ELM-120 and the like. Examples of the heterocycle-containing epoxy resin include Araldite PT810 manufactured by Ciba Specialty Chemicals, and ERL4234, ERL4299, ERL4221, and ERL4206 manufactured by UCC. These epoxy resins can be used alone or in combination of two or more.
(Epoxy resin curing agent)
When using an epoxy resin, it is preferable to use an epoxy resin curing agent. As the epoxy resin curing agent, a commonly used known curing agent can be used, and examples thereof include amines, polyamides, acid anhydrides, polysulfides, boron trifluoride, bisphenol A, bisphenol F, and bisphenol S. Bisphenols having two or more such phenolic hydroxyl groups in one molecule, phenol novolak resins, bisphenol A novolak resins, and phenol resins such as cresol novolak resins are exemplified. In particular, a phenol resin such as a phenol novolak resin, a bisphenol A novolak resin, or a cresol novolak resin is preferable because of its excellent electric corrosion resistance when absorbing moisture.
Preferred among the phenol resin curing agents are, for example, phenolite LF2882, phenolite LF2822, phenolite TD-2090, phenolite TD-2149, phenolite manufactured by Dainippon Ink and Chemicals, Inc. VH-4150, Phenolite VH4170, manufactured by Meiwa Kasei Co., Ltd., trade name: H-1, manufactured by Japan Epoxy Resin Co., Ltd., trade name: epicure MP402FPY, epicure YL6065, epicure YLH129B65 and Mitsui Chemicals, Inc., product Name: Millex XL, Millex XLC, Millex RN, Millex RS, Millex VR and the like.
(Compound that generates a base upon irradiation)
The compound that generates a base upon irradiation with radiation is a compound that generates a base upon irradiation with radiation, and the generated base increases the curing reaction rate of the thermosetting resin. The base to be generated is preferably a strongly basic compound from the viewpoint of reactivity and curing rate. Generally, a pKa value which is a logarithm of an acid dissociation constant is used as an index of basicity, and a base having a pKa value in an aqueous solution of 7 or more is preferable, and a base of 9 or more is more preferable. In addition, as the compound that generates a base upon irradiation with radiation, it is preferable to use a compound that generates a base upon irradiation with light having a wavelength of 150 to 750 nm. In order to efficiently generate a base when using a general light source, Compounds that generate a base upon irradiation with light of 250 to 500 nm are more preferred.
Examples of such basicity include imidazole derivatives such as imidazole, 2,4-dimethylimidazole and 1-methylimidazole, piperazine derivatives such as piperazine and 2,5-dimethylpiperazine, piperidine and 1,2-dimethylpiperidine. Piperidine derivatives such as, proline derivatives, trimethylamine, triethylamine, trialkylamine derivatives such as triethanolamine, 4-methylaminopyridine, pyridine derivatives substituted with an amino group or an alkylamino group at the 4-position such as 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 Include benzyl amine derivatives such as benzyl diethylamine.
Examples of those which generate a base upon irradiation include those described in Journal of Photopolymer Science and Technology, Vol. 12, 313-314 (1999), and Chemistry of Materials, Vol. 11, 170-176 (1999). Quaternary ammonium salt derivatives can be used. These are most suitable for curing epoxy resins because they generate highly basic trialkylamines upon irradiation with actinic rays.
Also, carbamic acid derivatives described in Journal of American Chemical Society 118, 12925 (1996), Polymer Journal 28, 795 (1996), and the like, and primary amino groups are generated by irradiation with actinic rays. Oxime derivatives can be used.
As the compound that generates a base upon irradiation, an α-aminoketone compound can be most suitably used in the present invention. Specifically, 2-methyl-1 (4- (methylthio) phenyl) -2-morpholinopropan-1-one (Irgacure 907 manufactured by Ciba Specialty Chemicals), which is commercially available as a photoradical generator, 2-benzyl Substitution of 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (Irgacure 369 manufactured by Ciba Specialty Chemicals), hexaarylbisimidazole derivative (halogen, alkoxy group, nitro group, cyano group, etc.) A phenyl group may be substituted), benzoisoxazolone derivatives, and the like.
The above-mentioned α-aminoketone compound has no steric hindrance to cure the thermosetting resin due to steric hindrance, but by irradiating, the α-aminoketone compound dissociates and the steric hindrance is reduced. It is presumed to have a function of accelerating the curing of the thermosetting resin.
In addition to the base generator by the actinic ray, a basic compound is generated by a light Fries rearrangement, a light Claisen rearrangement (light Cleisen rearrangement), a Curtius rearrangement (Curtius rearrangement), and a Stevens rearrangement (Stevens rearrangement) to cure the epoxy resin. It can be carried out.
(Amine imide compound)
As the compound that generates a base upon irradiation with radiation used in the present invention, an amine imide compound can be used in addition to the above-mentioned compounds. The amine imide is not particularly limited as long as it generates a base upon irradiation with actinic rays.
Specifically, for example, the following general formula (XXV) or (XXVI)

(Where R ¹ , R ² , R ³ Is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, cycloalkenyl having 4 to 8 carbon atoms A phenyl group substituted with a phenoxyalkyl group having 1 to 6 carbon atoms, a phenyl group, an electron donating group and / or an electron withdrawing group, a benzyl group, a benzyl group substituted with an electron donating group and / or an electron withdrawing group And the like. Examples of the alkyl group having 1 to 8 carbon atoms include an isopropyl group, an isobutyl group, a t-butyl group and the like in addition to a linear alkyl group. Among these substituents, alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 6 to 8 carbon atoms, and phenoxyalkyl groups having 1 to 6 carbon atoms are preferred from the viewpoints of simplicity of synthesis, solubility of amine imide, and the like. Is preferred. Also, R ⁴ Independently represents an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, a cycloalkyl group having 4 to 8 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a phenyl group. )
The compound represented by is mentioned.
Ar in the above general formula (II) ¹ Is an aromatic group represented by the general formulas (IV) to (XVI), and Ar in the general formula (2) ² Is preferably an aromatic group represented by the following formulas (XVII) to (XXV). Ar ¹ In terms of thermal stability and absorption wavelength, ²⁹ ~ R ³⁶ Is preferably a carbonyl group having 1 to 6 carbon atoms, a cyano group or a nitro group, which is an electron-withdrawing group.
A known method can be used for the synthesis of the amine imide. See, for example, Encyclopedia of Polymer Science and Engineering, John Wiley & Sons Ltd. (1985), vol. 1, p. 740, obtained from the reaction of the corresponding carboxylic acid ester with a halogenated hydrazine and sodium alkoxide or the reaction of the carboxylic acid ester with hydrazine and an epoxy compound. Can be. Considering the simplicity and safety of synthesis, a method of synthesizing a corresponding carboxylic acid ester with hydrazine and an epoxy compound is particularly preferable. The synthesis temperature and the synthesis time are not particularly limited as long as the starting material used is not decomposed, but generally the desired amine imide compound is stirred at a temperature of 0 to 100 ° C. for 30 minutes to 7 days. Obtainable.
(Imidazolium salt)
In addition, as the compound that generates a base upon irradiation with radiation used in the present invention, imidazolium salts can be used in addition to the above compounds. Examples of the imidazolium salt include an imidazolium salt compound represented by the general formula (1) or (2).

(Where R ¹ , R ² , R ³ , R ⁴ Is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, cycloalkenyl having 4 to 8 carbon atoms A phenoxyalkyl group having 1 to 6 carbon atoms, a phenylalkyl group having 1 to 6 carbon atoms, a cyanoalkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a phenyl group, an electron donating group, and A phenyl group substituted with an electron-withdrawing group, a benzyl group, a benzyl group substituted with an electron-donating group and / or an electron-withdrawing group, a nitro group, a cyano group, a mercapto group, a thiomethyl group, fluorine, bromine, chlorine, Shows iodine.
Also, Ar ₁ Is an aromatic group represented by the following formulas (I) to (XIV),

(Where R ⁵ ~ R ²⁸ Is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, a cycloalkyl having 4 to 8 carbon atoms Group, cycloalkenyl group having 4 to 8 carbon atoms, amino group, alkylamino group having 1 to 6 carbon atoms, dialkylamino group having 1 to 3 carbon atoms, morpholino group, mercapto group, hydroxyl group, hydroxy group having 1 to 6 carbon atoms Alkyl group, fluorine, chlorine, halogen such as bromine, ester group having 1 to 6 carbon atoms, carbonyl group having 1 to 6 carbon atoms, aldehyde group, cyano group, trifluoromethyl group, cyano group, nitro group, phenyl group, A phenyl group substituted with an electron donating group and / or an electron withdrawing group, and a benzyl group substituted with an electron donating group and / or an electron withdrawing group. In the formula, T, U, V, W, Y and Z each independently represent any one of carbon, nitrogen, oxygen and sulfur atoms. )
Ar ₂ Is an aromatic group represented by the following formulas (XV) to (XXIII),

(Where R ₂₉ ~ R ₃₆ Is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, cycloalkyl having 4 to 8 carbon atoms Group, cycloalkenyl group having 4 to 8 carbon atoms, amino group, alkylamino group having 1 to 6 carbon atoms, dialkylamino group having 1 to 3 carbon atoms, morpholino group, mercapto group, hydroxyl group, hydroxy group having 1 to 6 carbon atoms Alkyl group, halogen such as fluorine, chlorine, bromine, ester group having 1 to 6 carbon atoms, carbonyl group having 1 to 6 carbon atoms, aldehyde group, cyano group, trifluoromethyl group, cyano group, nitro group, phenyl group, A phenyl group substituted with an electron donating group and / or an electron withdrawing group, and a benzyl group substituted with an electron donating group and / or an electron withdrawing group. In the formula, A, B, D, and E each independently represent any of carbon, nitrogen, oxygen, and a sulfur atom, and these are bonded to carbon, nitrogen, an alkyl group having 1 to 6 carbon atoms, oxygen, and sulfur. May be. )
Also, X ⁻ Is a dialkyldithiocarbamic acid having 1 to 6 carbon atoms, and boric acid represented by the following formula (XXIV).

(Where R ₃₇ ~ R ₄₀ Is independently hydrogen, fluorine, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a fluorophenyl group in which at least one fluorine is substituted, or an imidazole group. ))
For the synthesis of the imidazolium salt compound represented by the general formula (1) or (2), which generates a base by light irradiation used in the present invention, a known method can be used. In view of the above, a method of synthesizing an imidazolium salt by an anion exchange reaction after synthesizing an imidazolium halide salt with a halogenated alkyl ketone derivative and an imidazole derivative as shown in the following formula (XXVII) is preferable.

The synthesis temperature and the synthesis time are not particularly limited as long as the starting material used is not decomposed, but generally the desired imidazolium salt is stirred at a temperature of 0 to 100 ° C. for 30 minutes to 7 days. A compound can be obtained. These compounds do not show reactivity with the epoxy resin when irradiated with no radiation at room temperature, and therefore have a feature that storage stability at room temperature is extremely excellent.
The amount of the compound that generates a base upon irradiation with radiation as exemplified above is preferably 0.01 to 200 parts by weight, more preferably 0.02 to 150 parts by weight, based on 100 parts by weight of the epoxy resin. When the amount is less than 0.01 part by weight, the adhesive strength at the time of pickup tends to hardly decrease, and depending on the compound used, the heat resistance may decrease. If the amount exceeds 200 parts by weight, the properties, storage stability, and physical properties of the adhesive film tend to deteriorate.
(Singlet sensitizer, triplet sensitizer)
In addition, a sensitizer may be added to the adhesive layer forming the adhesive sheet of the present invention for the purpose of increasing irradiation light and increasing sensitivity. As the sensitizer to be used, known singlet sensitizers and triplet sensitizers can be used as long as they do not adversely affect the curable composition.
As the sensitizer, for example, aromatic compound derivatives such as naphthalene, anthracene, and pyrene, carbazole derivatives, benzophenone derivatives, benzoin derivatives, thioxanthone derivatives, and coumarin derivatives are preferably used.
It is necessary to refer to the absorption wavelength and molar extinction coefficient of the sensitizer for the amount of the sensitizer to be used. (C) 0.01 to 10 parts by weight based on 1 part by weight of the base generated by irradiation Part is preferable, 0.1 to 5 parts by weight is more preferable, and 0.1 to 2 parts is particularly preferable. When the amount of the sensitizer is 0.01 part by weight or less, the efficiency of light absorption tends to be low, and when the amount exceeds 10 parts by weight, the light transmittance tends to deteriorate.
As the sensitizer used in the present invention, known singlet sensitizers and triplet sensitizers can be used as long as they do not adversely affect the curable composition. For example, aromatic compound derivatives such as naphthalene, anthracene, and pyrene, carbazole derivatives, aromatic carbonyl compounds, benzophenone derivatives, benzoin derivatives, thioxanthone derivatives, and coumarin derivatives are preferably used. In particular, among these, a naphthalene derivative, an anthracene derivative, a carbazole derivative, and a thioxanthone derivative, a benzophenone derivative, and a benzoin derivative are most preferable as the singlet sensitizer, and as the triplet sensitizer. For example, 1-methylnaphthalene, 2-methylnaphthalene, 1-fluoronaphthalene, 1-chloronaphthalene, 2-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene, 1-iodnaphthalene, 2-iodonaphthalene, 1-naphthol , 2-naphthol, compounds represented by the following general formulas (I) to (XXIII),

(Where R ⁵ ~ R ²⁸ Is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, cycloalkyl having 4 to 8 carbon atoms Group, cycloalkenyl group having 4 to 8 carbon atoms, amino group, alkylamino group having 1 to 6 carbon atoms, dialkylamino group having 1 to 3 carbon atoms, morpholino group, mercapto group, hydroxyl group, hydroxy group having 1 to 6 carbon atoms Alkyl group, fluorine, chlorine, halogen such as bromine, ester group having 1 to 6 carbon atoms, carbonyl group having 1 to 6 carbon atoms, aldehyde group, cyano group, trifluoromethyl group, cyano group, nitro group, benzoyl group, A phenyl group, a phenyl group substituted with an electron donating group and / or an electron withdrawing group, and a benzyl group substituted with an electron donating group and / or an electron withdrawing group. In the formula, T, U, V, W, Y and Z each independently represent any one of carbon, nitrogen, oxygen and sulfur atoms. )

(Where R ²⁹ ~ R ³⁶ Is independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, cycloalkyl having 4 to 8 carbon atoms Group, cycloalkenyl group having 4 to 8 carbon atoms, amino group, alkylamino group having 1 to 6 carbon atoms, dialkylamino group having 1 to 3 carbon atoms, morpholino group, mercapto group, hydroxyl group, hydroxy group having 1 to 6 carbon atoms Alkyl group, halogen such as fluorine, chlorine, bromine, ester group having 1 to 6 carbon atoms, carbonyl group having 1 to 6 carbon atoms, aldehyde group, cyano group, trifluoromethyl group, cyano group, nitro group, phenyl group, A phenyl group substituted with an electron donating group and / or an electron withdrawing group, and a benzyl group substituted with an electron donating group and / or an electron withdrawing group. In the formula, A, B, D, and E are each independently any one of carbon, nitrogen, oxygen, and a sulfur atom, which may be bonded to carbon, nitrogen, an alkyl group having 1 to 6 carbon atoms, oxygen, or sulfur. good. ) And the like. In addition, 1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dicyanonaphthalene, anthracene, 1,2-benzanthracene, 9,10-dichloroanthracene, 9,10-dibromoanthracene, 9,10-diphenyl Anthracene, 9-cyanoanthracene, 9,10-dicyanoanthracene, 2,6,9,10-tetracyanoanthracene, carbazole, 9-methylcarbazole, 9-phenylcarbazole, 9-prop-2-ynyl-9H-carbazole, 9-propyl-9H-carbazole, 9-vinylcarbazole, 9H-carbazole-9-ethanol, 9-methyl-3-nitro-9H-carbazole, 9-methyl-3,6-dinitro-9H-carbazole, 9-octa Noylcarbazole, 9-carba Methanol, 9-carbazolepropionic acid, 9-carbazolepropionitrile, 9-decyl-3,6-dinitro-9H-carbazole, 9-ethyl-3,6-dinitro-9H-carbazole, 9-ethyl-3-nitro Carbazole, 9-ethylcarbazole, 9-isopropylcarbazole, 9- (ethoxycarbonylmethyl) carbazole, 9- (morpholinomethyl) carbazole, 9-acetylcarbazole, 9-allylcarbazole, 9-benzyl-9H-carbazole, 9-carbazole Acetic acid, 9- (2-nitrophenyl) carbazole, 9- (4-methoxyphenyl) carbazole, 9- (1-ethoxy-2-methyl-propyl) -9H-carbazole, 3-nitrocarbazole, 4-hydroxycarbazole, 3,6 Dinitro-9H-carbazole, 3,6-diphenyl-9H-carbazole, 2-hydroxycarbazole, 3,6-diacetyl-9-ethylcarbazole, benzophenone, 4-phenylbenzophenone, 4,4'-bis (dimethoxy) benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, methyl 2-benzoylbenzoate, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 3,3 ' -Dimethyl-4-methoxybenzophenone, 2,4,6-trimethylbenzophenone, [4- (4-methylphenylthio) phenyl] -phenylmethanone, xanthone, thioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, -Isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 1-chloro-4-propoxythioxanthone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl Ether, benzoin n-butyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethanone, and 2,2-diethoxy-1,2-diphenylethanone. These may be used alone or in combination of two or more.
As described above, (c) a compound that generates a base upon irradiation with light does not show reactivity with a thermopolymerizable compound such as an epoxy resin at room temperature without irradiation with radiation. It has the characteristic of being very good.
(Thermoplastic resin)
The adhesive layer forming the adhesive sheet of the present invention may contain a thermoplastic resin for the purpose of improving film formability.
The thermoplastic resin is not particularly limited as long as it is a resin having thermoplasticity, or at least a resin having thermoplasticity in an uncured state and forming a crosslinked structure after heating, but has a Tg (glass transition temperature) of − It is preferable that the weight average molecular weight at 50 to 10 ° C is 100,000 to 1,000,000, or that the Tg is 10 to 100 ° C and the weight average molecular weight is 5,000 to 200,000.
As the former thermoplastic resin, it is preferable to use a polymer containing a functional monomer, and as the latter thermoplastic resin, for example, a polyimide resin, a polyamide resin, a polyetherimide resin, a polyamideimide resin, a polyester resin, Examples thereof include a polyesterimide resin, a phenoxy resin, a polysulfone resin, a polyethersulfone resin, a polyphenylene sulfide resin, and a polyetherketone resin. Among them, a polyimide resin is preferable.
Examples of the functional group in the polymer containing the above functional monomer include a glycidyl group, an acryloyl group, a methacryloyl group, a hydroxyl group, a carboxyl group, an isocyanurate group, an amino group, an amide group, and the like. Among them, a glycidyl group is preferable. More specifically, a glycidyl group-containing (meth) acrylic copolymer containing a functional monomer such as glycidyl acrylate or glycidyl methacrylate is preferable, and it is more incompatible with a thermosetting resin such as an epoxy resin. preferable.
(High molecular weight component containing a functional monomer and having a weight average molecular weight of 100,000 or more)
Examples of the high molecular weight component having a weight average molecular weight of 100,000 or more containing the functional monomer include a glycidyl group containing a functional monomer such as glycidyl acrylate or glycidyl methacrylate, and having a weight average molecular weight of 100,000 or more. (Meth) acrylic copolymers and the like can be mentioned, and among them, those which are incompatible with the epoxy resin are preferable.
As the glycidyl group-containing (meth) acrylic copolymer, for example, a (meth) acrylic ester copolymer, acrylic rubber and the like can be used, and acrylic rubber is more preferable. The acrylic rubber is a rubber having an acrylic ester as a main component and mainly composed of a copolymer such as butyl acrylate and acrylonitrile or a copolymer such as ethyl acrylate and acrylonitrile.
The above-mentioned functional monomer refers to a monomer having a functional group. As such a monomer, glycidyl acrylate or glycidyl methacrylate is preferably used. Examples of such a glycidyl group-containing (meth) acrylic copolymer having a weight average molecular weight of 100,000 or more include HTR-860P-3 manufactured by Nagase ChemteX Corporation.
The amount of the epoxy resin-containing repeating unit such as glycidyl acrylate or glycidyl methacrylate is preferably 0.5 to 6.0% by weight, more preferably 0.5 to 5.0% by weight, and 0.8 to 5.0% by weight. % Is particularly preferred. When the amount of the glycidyl group-containing repeating unit is in this range, the adhesive force can be ensured and gelation can be prevented.
Examples of the functional monomer other than glycidyl acrylate and glycidyl methacrylate include, for example, ethyl (meth) acrylate and butyl (meth) acrylate, and these can be used alone or in combination of two or more. In the present invention, ethyl (meth) acrylate refers to both ethyl acrylate and ethyl methacrylate. The mixing ratio when the functional monomers are used in combination is determined in consideration of the Tg of the glycidyl group-containing (meth) acrylic copolymer, and the Tg is preferably -10 ° C or higher. If the Tg is -10 ° C or higher, the tackiness of the adhesive layer in the B-stage state is appropriate, and there is no problem in handling.
When the above monomers are polymerized to produce a high molecular weight component containing a functional monomer and having a weight average molecular weight of 100,000 or more, the polymerization method is not particularly limited, and for example, a method such as pearl polymerization or solution polymerization may be used. Can be used.
In the present invention, the weight average molecular weight of the high molecular weight component containing the functional monomer is 100,000 or more, preferably 300,000 to 3,000,000, and more preferably 500,000 to 2,000,000. When the weight average molecular weight is in this range, the strength, flexibility, and tackiness in a sheet or film form are appropriate, and the flowability is appropriate, so that the circuit filling property of the wiring can be ensured. In the present invention, the weight average molecular weight is a value measured by gel permeation chromatography and converted using a standard polystyrene calibration curve as described later in the section of the evaluation method.
The amount of the high molecular weight component containing a functional monomer and having a weight average molecular weight of 100,000 or more is preferably 10 to 400 parts by weight based on 100 parts by weight of the thermopolymerizable component. Within this range, the storage elastic modulus and the suppression of flow during molding can be ensured, and sufficient handling at high temperatures can be obtained. The use amount of the high molecular weight component is more preferably 15 to 350 parts by weight, and particularly preferably 20 to 300 parts by weight.
(Polyimide resin)
Among the thermoplastic resins, a polyimide resin, which is one of the preferable thermoplastic resins, can be obtained by subjecting a tetracarboxylic dianhydride and a 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 almost equimolar manner (addition order 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 precursor of polyimide, is generated.
The molecular weight of the polyamic acid can also be adjusted 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 above reactant (polyamic acid). The dehydration ring closure can be carried out by a thermal ring closure method using a heat treatment and a chemical ring closure method using a dehydrating agent.
The tetracarboxylic dianhydride used as a raw material of the polyimide resin is not particularly limited, and includes, for example, 1,2- (ethylene) bis (trimellitate anhydride), 1,3- (trimethylene) bis (trimellitate anhydride), 1,4- (tetramethylene) bis (trimellitate anhydride), 1,5- (pentamethylene) bis (trimellitate anhydride), 1,6- (hexamethylene) bis (trimellitate anhydride), 1,7- ( Heptamethylene) bis (trimellitate anhydride), 1,8- (octamethylene) bis (trimellitate anhydride), 1,9- (nonamethylene) bis (trimellitate anhydride), 1,10- (decamethylene) bis (trimellitate anhydride) ), 1,12- (dodecamethylene) bis (trimellitate anhydride), 1,16- (hexadeca) (Tylene) bis (trimellitate 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 dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 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'-benzophenonetetracarboxylic dianhydride, 3,3,3', 4'-benzophenonetetracarboxylic 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-tet 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 (trimellitate 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, , 2,3,4-cyclobutanetetracarboxylic dianhydride, bis (exo-bicyclo [2,2,1] heptane-2,3-dicarboxylic dianhydride, bicyclo- [2,2,2] -octo -7-ene 2,3,5,6-tetracarboxylic 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 and the like can be used. It may be used in combination one or more of them.
The diamine used as a raw material of the polyimide is not particularly limited, and examples thereof include 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'-diaminodiphenylatemethane, 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 Nodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylketone, 3 , 4'-Diaminodiphenylketone, 4,4'-diaminodiphenylketone, 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 Minophenoxy) 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-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 And aromatic diamines such as bis (4- (3-aminoenoxy) phenyl) sulfone, bis (4- (4-aminoenoxy) phenyl) sulfone, 3,5-diaminobenzoic acid, 1,2-diaminoethane, 1,3-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 (3)

(Where R ₁ And R ₂ Represents a divalent hydrocarbon group having 1 to 30 carbon atoms, which may be the same or different; ₃ And R ₄ Represents a monovalent hydrocarbon group, which may be the same or different, and m is an integer of 1 or more.
Diaminopolysiloxane represented by the formula: 1,3-bis (aminomethyl) cyclohexane, Jeffamine D-230, D-400, D-2000, D-4000, ED-600, ED- manufactured by San Techno Chemical Co., Ltd. Aliphatic diamines such as polyoxyalkylenediamines such as 900, ED-2001 and EDR-148 can be used, and one or more of these can be used in combination. The Tg of the polyimide resin is preferably from 0 to 200 ° C., and the weight average molecular weight is preferably from 10,000 to 200,000.
(Other components)
By having the components described so far, an adhesive sheet having excellent characteristics can be obtained. However, in order to further optimize the characteristics or according to the structure of the semiconductor package to be applied, the following other adhesive sheets can be obtained. Components can be used.
(Radiation polymerizable component)
A radiation-polymerizable component can be included as a component constituting the adhesive layer used in the adhesive sheet of the present invention for the purpose of improving the sensitivity of polymerization by irradiation. There is no particular limitation on the radiation polymerizable component, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, Pentenyl acrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane diacrylate , Trimethylolpropane triacrylate, trimethylolpropane dimethac Rate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol triacrylate, penta Erythritol tetraacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol hexamethacrylate, styrene, divinylbenzene, 4-vinyltoluene, 4-vinylpyridine, N-vinylpyrrolidone, 2-hydroxyethyl Acrylate, 2-hydroxyethyl methacrylate, 1,3-acryloyloxy-2-hydroxypropa , 1,2-methacryloyloxy-2-hydroxypropane, methylenebisacrylamide, N, N- dimethyl acrylamide, N- methylol acrylamide, tris (beta-hydroxyethyl) triacrylate isocyanurate represented by the following general formula (4)

(Where R ₁ And R ₂ Represents hydrogen or a methyl group, and q and r are integers of 1 or more.
And a diol represented by the general formula (5):

(Where n is an integer of 0 to 1; ₃ Is a divalent or trivalent organic group having 1 to 30 carbon atoms)
An isocyanate compound represented by the general formula (6):

(Where R ₄ Is hydrogen or a methyl group; ₅ Is an ethylene group or a propylene group)
A urethane acrylate or urethane methacrylate comprising a compound represented by the formula:

(Where R ₆ Represents a divalent organic group having 2 to 30 carbon atoms)
And a diamine represented by the general formula (8):

(Where n is an integer of 0 to 1; ₇ Is a divalent or trivalent organic group having 1 to 30 carbon atoms)
An isocyanate compound represented by the general formula (9):

(Where n is an integer of 0 to 1)
A compound having at least one ethylenically unsaturated group and one functional group such as an oxirane ring, an isocyanate group, a hydroxyl group, a carboxyl group, etc. in a urea methacrylate or a vinyl copolymer containing a functional group comprising a compound represented by the formula: Can also be used, such as radiation-polymerizable copolymers having an ethylenically unsaturated group in the side chain obtained by the addition reaction thereof. These radiation polymerizable compounds can be used alone or in combination of two or more.
In addition, a compound capable of generating a base that accelerates the curing of the epoxy resin upon irradiation with radiation may be used to make the epoxy resin radiation polymerizable.
(Curing accelerator)
Further, a curing accelerator can be further added to the adhesive layer forming the adhesive sheet of the present invention. The curing accelerator is not particularly limited and includes imidazoles, dicyandiamide derivatives, dicarboxylic dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylporate, 2-ethyl-4-methylimidazole tetraphenylborate, 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.
The addition amount of the curing accelerator is preferably from 0.1 to 5 parts by weight, more preferably from 0.2 to 3 parts by weight, based on 100 parts by weight of the thermopolymerizable component. When the amount is within this range, both curability and storage stability can be achieved. If the amount is less than 0.1 part by weight, the curability tends to be poor, and if it exceeds 5 parts by weight, the storage stability tends to decrease.
In addition, a photopolymerization initiator that generates free radicals by irradiating active light may be added to the adhesive layer forming the adhesive sheet of the present invention to initiate polymerization of the radiation-polymerizable compound. . Examples of such photopolymerization initiators include benzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N, N'-tetraethyl-4,4'-diaminobenzophenone, Methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2,2-dimethoxy-1,2-diphenylethan-1-one, 1- Aromatic ketones such as hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropanone-1,2,4-diethylthioxanthone, 2-ethylanthraquinone and phenanthrenequinone , Benzoin methyl ether, benzoin ethyl ether, benzoinf Benzoin ethers such as benzyl ether; benzoin such as methyl benzoin and ethyl benzoin; benzyl derivatives such as benzyl dimethyl ketal; 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer; 2- (o-chlorophenyl) -4 2,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer Dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxy 2,4,5-triarylimidazole dimer such as phenyl) -4,5-diphenylimidazole dimer , 9-phenyl acridine, 1,7-bis (9,9'-acridinyl) can be used, such as acridine derivatives such as heptane, it can be used alone or in combination of two or more. The amount of the photopolymerization initiator used is not particularly limited, but is preferably 0.01 to 30 parts by weight based on 100 parts by weight of the radiation-polymerizable compound.
Further, a filler can be added to 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, imparting thixotropic properties, and the like. The filler is not particularly limited and includes, 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, and nitrided. Examples thereof include boron, crystalline silica, and amorphous silica, and the shape of the filler is not particularly limited. These fillers can be used alone or in combination of two or more.
Among them, aluminum oxide, aluminum nitride, boron nitride, crystalline silica, amorphous silica, and the like are preferable for improving thermal conductivity. In addition, 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, Silica and amorphous silica are preferred.
The amount of the filler used is preferably 1 to 20 parts by weight based on 100 parts by weight of 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 is more than 20 parts by weight, problems such as an increase in storage modulus of the adhesive layer, a decrease in adhesiveness, and a decrease in electrical properties due to remaining voids are caused. Tend.
In addition, various kinds of coupling agents can be added to the adhesive layer forming the adhesive sheet of the present invention in order to improve interfacial bonding between different kinds of materials. Examples of the coupling agent include silane-based, titanium-based, and aluminum-based coupling agents. Among them, a silane-based coupling agent is preferable because of its high effect.
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-aminopropyltrimethoxysilane 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-chloropropylmethyldimet 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 kinds can be used in combination.
Examples of the titanium-based coupling agent include isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, and 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, Ruphenyloxyacetate titanate, bis (dioctylpyrophosphate) oxyacetate titanate, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium ethylacetonate, titanium Octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium thiethanol aminate, polyhydroxytitanium 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-triethanolaminotitanate, octylene glycol titanate, tetra-n-butoxytitanium polymer, tri-n-butoxytitanium mono Stearate polymers, tri-n-butoxytitanium monostearate, and the like can be used, and they can be used alone or in combination of two or more.
Examples of the aluminum-based coupling agent include ethyl acetoacetate aluminum diisopropylate, aluminum toys (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetyl acetate bis (ethyl acetoacetate), and aluminum tris (acetyl acetoacetate). Aluminum chelate compounds such as aluminum-monoisopropoxymonooleoxyethyl acetoacetate, aluminum-di-n-butoxide monoethylacetoacetate, aluminum-di-iso-propoxide-monoethylacetoacetate, 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.
The amount of the coupling agent to be used is preferably 0.001 to 10 parts by weight based on 100 parts by weight of the adhesive layer from the viewpoint of the effect, heat resistance and cost.
An ion scavenger may be further added to the adhesive layer forming the adhesive sheet of the present invention in order to adsorb ionic impurities and improve insulation reliability when absorbing moisture. Such ion scavengers are not particularly limited, for example, triazine thiol compounds, compounds such as bisphenol-based reducing agents, compounds known as copper damage inhibitors for preventing copper from ionizing and dissolving, zirconium-based compounds And an inorganic ion adsorbent such as an antimony bismuth-based magnesium aluminum compound.
The amount of the ion scavenger to be used is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the adhesive layer from the viewpoint of the effect of addition, heat resistance, cost and the like.
(Storage modulus)
The adhesive layer forming the adhesive sheet of the present invention preferably has a storage elastic modulus of 10 to 2000 MPa at 25 ° C and 3 to 50 MPa at 260 ° C when cured by heating. The storage elastic modulus at 25 ° C is more preferably from 20 to 1900 MPa, particularly preferably from 50 to 1800 MPa. Further, the storage elastic modulus at 260 ° C. is more preferably 5 to 50 MPa, and particularly preferably 7 to 50 MPa. When the storage elastic modulus is in this range, the effect of relaxing the thermal stress generated by the difference in the coefficient of thermal expansion between the semiconductor element and the support member is maintained, and the occurrence of peeling and cracks can be suppressed, and the handling property of the adhesive can be reduced. And the occurrence of reflow cracks can be suppressed. The conditions of the heat curing vary depending on the composition of the adhesive layer, but are usually in the range of 120 to 240 ° C. for 5 to 600 minutes.
The storage elastic modulus is measured, for example, by using a dynamic viscoelasticity measuring device (manufactured by Rheology Co., Ltd., DVE-V4), applying a tensile load to the cured adhesive, applying a frequency of 10 Hz, and a heating rate of 5 to 10 ° C./min. The temperature can be measured in a temperature dependence measurement mode in which the temperature is measured from −50 ° C. to 300 ° C.
<Description of parameters>
The adhesive sheet of the present invention has a sufficient adhesive force so that the semiconductor element does not scatter at the time of dicing, and then picks up by controlling the adhesive force between the adhesive layer and the base material layer by irradiating radiation. At the same time, it satisfies the conflicting demands of having a low adhesive strength without damaging each element. Therefore, the dicing and die bonding steps can be completed with a single film. Further, the adhesive sheet of the present invention has heat resistance and moisture resistance required when a semiconductor element having a large difference in thermal expansion coefficient is mounted on the semiconductor element mounting support member.
As a result of examining properties and chemistry from the viewpoint of further optimizing the adhesive sheet of the present invention having such an operation and effect, the present inventors specified a predetermined parameter as described below. It has been found that the above-mentioned effects can be more suitably obtained regardless of the raw material used for the adhesive sheet.
That is, the present invention relates to an adhesive sheet having predetermined parameters.
First, for the purpose of facilitating the understanding of the present invention, the significance of parameters in the present invention will be described. In the present invention, it is assumed that the measurement target of the flow amount, the melt viscosity and the storage elastic modulus is the adhesive layer.
In the present invention, the flow amount is an index of fluidity. For example, an adhesive sheet is cut into a size of 10 × 20 mm, placed on a slide glass, and heated at 160 ° C. and 0.8 MPa for 18 seconds. This is a value obtained by measuring the length of a portion that has been pressed and protruded to the periphery from the initial size with an optical microscope.
In the present invention, the term “adhesive strength” means a 90 ° peel strength at the interface between the adhesive layer and the base material layer, unless otherwise specified. This adhesive strength is determined, for example, by bonding the above-mentioned adhesive sheet to the back surface of the semiconductor wafer to be diced at room temperature or by heating while applying pressure, and then setting only the substrate layer to a tensile angle of 90 ° and a tensile speed of 50 mm / min. It is a value obtained by measuring the peeling force when pulled at
In the present invention, the melt viscosity is an index of film fluidity, and is a value obtained by, for example, measuring and calculating by a parallel plate plastometer method. The melt viscosity is determined, for example, by laminating eight adhesive sheets, producing a film having a thickness of about 400 μm, and punching the film into a circular shape having a diameter of 11.3 mm as a sample at 160 ° C. under a load of 2.5 kgf for 5 seconds. The pressure is calculated by using Expression 1 described below from the thickness of the sample before and after the pressing.
In the present invention, the tack strength is an index of the adhesive property of the adhesive layer. For example, using a tacking tester manufactured by RHESCA, the peeling rate is determined by the method described in JISZ0237-1991. 10mm / s, contact load 100gf / cm ² , And a contact time of 1 second at a measurement temperature of 25 ° C.
In the present invention, tan δ is the loss modulus / storage modulus, which is an energy dissipation term, that is, an index of fluidity at that temperature. It is a value measured under the conditions of 5 ° C./min, tensile mode, and frequency of 10 Hz.
In the present invention, the storage elastic modulus is an index of the hardness (softness) of a film, and is, for example, a dynamic viscoelasticity device at a heating rate of 5 ° C./min, a tensile mode, and a frequency of 10 Hz. It is a value obtained by measuring under conditions.
The parameters used in the present invention have been outlined above, and more specific measurement methods will be described in detail in the examples below.
Next, the significance of the critical value of the parameter will be described with reference to some preferred embodiments of the present invention. It goes without saying that the present invention is not limited to the following embodiments.
(First aspect)
One embodiment of the present invention is an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. In the adhesive layer, (A1) the adhesive strength between the adhesive layer and the base material layer before irradiation is 200 mN / cm or more, and (B1) the adhesive strength before irradiation is 160 mN / cm. An adhesive sheet having a flow rate at 100C of 100 to 10,000 m is exemplified.
(Second aspect)
According to another embodiment of the present invention, there is provided an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. In the adhesive layer, (A1) the adhesive strength between the adhesive layer and the substrate layer before irradiation is 200 mN / cm or more, and (B2) the adhesive strength before irradiation is 160 mN / cm. An adhesive sheet having a melt viscosity at 50 ° C of 50 to 100000 Pa · s is exemplified.
In the adhesive sheet as one embodiment of the present invention, the flow amount of the adhesive layer before irradiation is 100 to 10000 μm, more preferably 100 to 6000 μm, and further preferably 200 to 4000 μm. Most preferably, it is 500 to 4000 μm. If the flow amount is less than 100 μm, the adhesive sheet may not sufficiently adhere to the semiconductor wafer to be diced, and if it exceeds 10,000 μm, workability such as handling properties may be reduced.
Further, in the adhesive sheet as one embodiment of the present invention, the flow amount ratio (flow amount after irradiation / flow amount before irradiation) of the adhesive layer before and after irradiation is preferably 0.1 or more, .15 or more, more preferably 0.2 or more. If this value is less than 0.1, the semiconductor element may not be sufficiently bonded in the bonding step between the semiconductor element and the support member. The maximum value of the flow amount ratio is not particularly limited, but the maximum value that can be usually taken is 1.0.
In the adhesive sheet as one embodiment of the present invention, the adhesive strength before irradiation (at the time of dicing) is preferably 200 mN / cm or more, and 250 mN / cm, from the viewpoint of preventing the semiconductor element from scattering at the time of dicing. It is more preferably at least 300 mN / cm, most preferably at least 350 mN / cm. There is no particular upper limit since the higher the adhesive strength, the more the semiconductor elements can be prevented from scattering. However, materials that can be easily obtained and those that can be manufactured by an appropriate manufacturing process are usually 25,000 mN / cm or less, and 10,000 mN / cm or less. Are relatively easy to manufacture.
In the adhesive sheet as one embodiment of the present invention, the adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) of the interface between the adhesive layer and the base material layer before and after irradiation with the 90 ° peeling force is 0. 0.5 or less, more preferably 0.4 or less, and even more preferably 0.3 or less. If this value is larger than 0.5, each element tends to be damaged during pickup. On the other hand, the lower limit of the adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) is not particularly limited, but is preferably 0.0001 or more from the viewpoint of workability, for example.
In the adhesive sheet as one embodiment of the present invention, a difference in adhesive strength (adhesive strength before irradiation-adhesive strength after irradiation) at the interface between the adhesive layer and the base material layer before and after radiation irradiation due to the 90 ° peeling force is 100 mN. / Cm or more, more preferably 150 mN / cm or more, further preferably 200 mN / cm, and most preferably 250 mN / cm or more. If this value is less than 100 mN / cm, each element tends to be damaged during pickup.
The adhesive sheet according to one embodiment of the present invention is characterized in that the adhesive layer has a flow rate at 160 ° C. before irradiation of radiation of 100 to 10,000 μm and a 90 ° peeling force before irradiation of 200 mN / cm or more. The dicing should be performed at a low temperature by making the adhesive strength difference (adhesive strength before irradiation-adhesive strength after irradiation) at or above 100 mN / cm between the adhesive layer / substrate layer interface before and after irradiation by the 90 ° peeling force. Despite being able to press-bond the adhesive sheet to the semiconductor wafer, it has a sufficient adhesive force to prevent the semiconductor elements from scattering during dicing, and has a low adhesive strength so as not to damage each element during pickup. Is very advantageous in terms of process cost and the flow rate ratio before and after irradiation (flow rate after irradiation / flow rate before irradiation) By over amount) is 0.1 or more, the bonding process between the semiconductor element and the support member to act as an adhesive sheet excellent in connection reliability.
Further, the adhesive sheet of the present invention has a melt viscosity at 160 ° C. of the adhesive layer before irradiation with radiation of 50 to 100,000 Pa · s, more preferably 50 to 10,000 Pa · s, and more preferably 50 to 1000 Pa · s. More preferably, s. If the melt viscosity is less than 50 Pa · s, the adhesive sheet may not sufficiently adhere to the semiconductor wafer to be diced, and if it exceeds 100,000 Pa · s, workability such as handling properties may be reduced. .
Further, in the adhesive sheet as one embodiment of the present invention, a melt viscosity ratio (melt viscosity after irradiation / melt viscosity before irradiation) of the adhesive layer before and after irradiation is 100 or less, and preferably 95 or less. It is more preferably 90 or less. If this value exceeds 100, there is a possibility that the semiconductor element cannot be sufficiently joined in the joining step between the semiconductor element and the support member.
The adhesive sheet as one embodiment of the present invention has a melt viscosity of 50 to 100000 Pa · s at 160 ° C. before irradiation of the pressure-sensitive adhesive and adhesive layer, and a radiation peeling force of 90 ° peeling force of 200 mN / cm or more, Furthermore, by making the adhesive strength difference (adhesive strength before irradiation-adhesive strength after irradiation) at or above 100 mN / cm at the interface between the adhesive layer and the base material layer before and after irradiation by the 90 ° peeling force, it is possible to reduce the temperature at a low temperature. Despite being able to pressure-bond the adhesive sheet to the semiconductor wafer to be diced, it has a sufficient adhesive strength so that the semiconductor elements do not scatter during dicing, and has a low adhesive strength that does not damage each element during pickup. Since the conflicting properties can be satisfied, it is very advantageous in terms of process cost, and the melt viscosity ratio before and after irradiation (melt viscosity after irradiation) By setting the ratio (degree / melt viscosity before irradiation) to 100 or less, it functions as an adhesive sheet having excellent connection reliability in the bonding step between the semiconductor element and the support member.
(Third aspect)
According to another embodiment of the present invention, there is provided an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive layer (A2) has a tack strength of 0.5 N or more at 25 ° C. by a 5.1 mmφ probe measurement before the radiation irradiation, and (B1) the radiation irradiation An adhesive sheet whose flow amount at 160 ° C. before is 100 to 10,000 μm is exemplified.
(Fourth aspect)
According to another embodiment of the present invention, there is provided an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive layer has a tack strength of not less than 0.5 N at 25 ° C. measured by a 5.1 mmφ probe measurement before irradiation with (A2) radiation, and (B2) irradiation with radiation. An adhesive sheet having a melt viscosity at 160 ° C. of 50 to 100000 Pa · s before is exemplified.
The adhesive sheet as one embodiment of the present invention may have a tack strength at 25 ° C. of the pressure-sensitive adhesive layer measured by a 5.1 mmφ probe before irradiation of radiation of 0.5 N or more, and 0.6 N or more. More preferably, it is more preferably 0.7 N or more, most preferably 0.8 N or more. If this value is less than 0.5 N, the semiconductor elements may be scattered during dicing.
Further, the adhesive sheet as one embodiment of the present invention has a tack strength difference (tack strength after irradiation−tack strength before irradiation) at 25 ° C. by a 5.1 mmφ probe measurement before and after irradiation of the adhesive layer, which is zero. 0.1 N or more, more preferably 0.15 N or more, even more preferably 0.2 N or more. If this value is less than 0.1 N, each element tends to be damaged during pickup.
In the fourth aspect, from the viewpoint that the semiconductor element can be suitably joined in the joining step of the semiconductor element and the support member, the adhesive sheet has a flow rate ratio before and after radiation irradiation (flow rate after irradiation / irradiation). The pre-flow amount is preferably 0.1 or more, and the melt viscosity ratio before and after irradiation (melt viscosity after irradiation / melt viscosity before irradiation) is preferably 100 or less.
The adhesive sheet according to one embodiment of the present invention has a flow rate at 160 ° C. of the adhesive layer before irradiation with 100 ° C. to 10,000 μm, and is measured by a 5.1 mmφ probe measurement before the irradiation of the adhesive layer. When the tack strength at 25 ° C. is 0.5 N or more, the tack strength difference at 25 ° C. (tack strength after irradiation−tack strength before irradiation) by a 5.1 mmφ probe measurement before and after irradiation of the adhesive layer is 0. By setting the pressure to 1 N or more, the adhesive sheet can be pressure-bonded to the semiconductor wafer to be diced at a low temperature. And the low contaminant strength, which is not possible, is extremely advantageous in terms of process cost and By flow amount ratio between the front and rear lines irradiation (flow amount / before irradiation flow amount after irradiation) to 0.1 or more, the bonding process between the semiconductor element and the support member to act as an adhesive sheet excellent in connection reliability.
Further, the adhesive sheet as one embodiment of the present invention has a melt viscosity at 160 ° C. of 50 to 100000 Pa · s before irradiation of the pressure-sensitive adhesive layer, and 5. Tack strength at 25 ° C measured by 1 mmφ probe at 25 ° C is 0.5 N or more, and tack difference at 25 ° C measured by 5.1 mmφ probe before and after irradiation of the adhesive layer (tack strength after irradiation-tack before irradiation) Strength) of 0.1 N or more, although the above-mentioned adhesive sheet can be pressure-bonded to the semiconductor wafer to be diced at a low temperature, it has sufficient adhesive strength so that the semiconductor elements are not scattered at the time of dicing, and each element at the time of pickup. It has a low adhesive strength that does not damage the surface, and it can satisfy the conflicting properties, so it is very advantageous in terms of process cost In both cases, by setting the melt viscosity ratio before and after radiation irradiation (melt viscosity after irradiation / melt viscosity before irradiation) to 100 or less, it functions as an adhesive sheet having excellent connection reliability in the bonding step between the semiconductor element and the support member.
In the first to fourth aspects described above, the adhesive strength after irradiation is preferably 100 mN / cm or less so as not to damage each element at the time of pickup. However, when bonding to a relatively thick semiconductor wafer, the thickness may be more than this. The value of 100 mN / cm or less is a value applicable to a semiconductor wafer of any thickness (for example, an extremely thin semiconductor wafer having a thickness of 20 μm, for example) as long as it is less than 100 mN / cm.
As a method for adjusting the adhesive strength and tack strength of the adhesive layer before irradiation with radiation to a desired range, the adhesive strength and tack strength are also increased by increasing the fluidity of the adhesive layer at room temperature. The fact that the adhesive strength and the tack strength tend to increase when the fluidity is reduced may be used. For example, in order to increase the fluidity, there are methods such as an increase in the content of the plasticizer and an increase in the content of the tackifier. Conversely, when the fluidity is reduced, the content of the compound may be reduced. Examples of the plasticizer include a monofunctional acrylic monomer, a monofunctional epoxy resin, a liquid epoxy resin, an acrylic resin, and an epoxy so-called diluent.
In addition, as a method for improving the flow amount before the radiation irradiation or a method for reducing the melt viscosity before the radiation irradiation of the adhesive layer, for example, addition of a diluent, use of a thermoplastic resin having a lower Tg, Use of an epoxy resin having a lower Tg and a curing agent is exemplified. More specifically, when polyimide is used as the thermoplastic resin, an acid monomer and a diamine monomer are selected so that the imide group concentration of the polyimide is reduced, and a polyimide having a relatively low Tg is obtained by synthesizing the polyimide. Can be When acrylic rubber is used, Tg can be reduced by increasing the number of carbon atoms in the alkyl group in the side chain of the acrylic rubber or increasing the flexibility of the main chain.
(Fifth aspect)
According to another embodiment of the present invention, there is provided an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive layer has a (C1) adhesive strength difference (adhesive strength before radiation-adhesive strength after radiation irradiation) at the interface between the adhesive layer and the base material layer before and after radiation irradiation of 100 mN / cm. And (D1) an adhesive sheet having a tan δ at 120 ° C before radiation irradiation of 0.1 or more and a tan δ at 180 ° C after radiation irradiation of 0.1 or more.
(Sixth aspect) Further, as one aspect of the present invention, an adhesive layer and a substrate layer are provided, and the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation. Wherein the adhesive layer comprises (C1) an adhesive strength difference between an adhesive layer / substrate layer interface before and after irradiation (adhesive strength before irradiation−adhesion after irradiation). (D2) an adhesive sheet having a storage modulus at 120 ° C. before irradiation of 10 MPa or less and a storage modulus at 180 ° C. after irradiation of 100 MPa or less.
In the fifth and sixth aspects, an adhesive sheet having the property (D1) is used from the viewpoint of controlling the fluidity of the adhesive layer, and when the adhesive sheet is laminated on a semiconductor wafer, sufficient adhesive strength is obtained. From the viewpoint of having sufficient adhesiveness at a temperature of 200 ° C. or less when a semiconductor element is bonded, an adhesive sheet having the characteristic (D2) is used. In the adhesive sheet, from the viewpoint of achieving good workability at the time of dicing and at the time of pick-up, the adhesive strength ratio of the adhesive layer / substrate layer interface before and after irradiation (adhesive strength after irradiation / radiation). (Adhesion strength before irradiation) is preferably 0.5 or less. Further, in the adhesive sheet, from the viewpoint of achieving better workability at the time of dicing and at the time of pickup, the adhesive strength before irradiation with radiation at the interface between the adhesive layer and the base material layer is 200 mN / cm or more. Preferably, the adhesive strength after irradiation is 100 mN / cm or less.
In the adhesive sheet as one embodiment of the present invention, tan δ at 120 ° C. of the adhesive layer before irradiation with radiation is preferably 0.1 or more, more preferably 0.3 or more. Further, it is preferable that tan δ at 180 ° C. of the adhesive layer after irradiation is 0.1 or more. When each tan δ is less than 0.1, for the former, when the adhesive sheet is laminated to the semiconductor wafer via the adhesive layer at any temperature between room temperature and 150 ° C., Sufficient adhesive strength cannot be ensured. In the latter case, when the semiconductor element is bonded to the support member via the adhesive layer, sufficient adhesiveness cannot be secured at a temperature of 200 ° C. or less. In this manner, by defining tan δ, the fluidity of the adhesive layer at a certain temperature can be accurately quantified, and the fluidity of the adhesive layer required for lamination to a semiconductor wafer and subsequent die bonding can be obtained. Can be managed.
Further, in the adhesive sheet, the adhesive strength before irradiation at the interface between the adhesive layer and the base material layer is 200 mN / cm or more, more preferably 250 mN / cm or more, and more preferably 300 mN / cm or more. More preferably, there is. If this value is less than 200 mN / cm, the semiconductor elements may be scattered during dicing. On the other hand, the adhesive strength after irradiation is preferably 100 mN / cm or less. If this value is larger than 100 mN / cm, each element tends to be damaged during pickup.
Further, in the adhesive sheet, the difference between the adhesive strength and the adhesive strength ratio at the interface between the adhesive layer and the base material layer before and after the irradiation of the radiation is the same as that described in the first to fourth embodiments. Can be applied for the following reasons.
In the adhesive sheet according to one embodiment of the present invention, the storage elastic modulus of the adhesive layer at 120 ° C. before irradiation is 10 MPa or less, more preferably 5 MPa or less, still more preferably 2 MPa or less, and 180 after irradiation. The storage elastic modulus at 100C is 100 MPa or less, more preferably 50 MPa or less, and still more preferably 10 MPa or less. Regarding the former, when the storage elastic modulus is greater than 10 MPa, when the adhesive sheet is laminated to the semiconductor wafer via the adhesive layer at any temperature from room temperature to 150 ° C., sufficient for the semiconductor wafer Adhesive strength cannot be secured. In the latter case, when the storage elastic modulus is larger than 100 MPa, when the semiconductor element is bonded to the supporting member via the adhesive layer, sufficient adhesion cannot be ensured at a temperature of 200 ° C. or lower.
(Seventh aspect)
According to another embodiment of the present invention, there is provided an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. (C2) difference in tack strength at 25 ° C. between before and after irradiation (tack strength at 25 ° C. before irradiation—tack strength at 25 ° C. after irradiation). ) Is 0.1 N / 5.1 mmΦ probe or more, and (D1) tan δ at 120 ° C. before irradiation is 0.1 or more, and tan δ at 180 ° C. after irradiation is 0.1 or more. Is mentioned.
(Eighth Aspect) Further, as one aspect of the present invention, an adhesive layer and a base layer are provided, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. (C2) a difference in tack strength at 25 ° C. between before and after radiation irradiation (tack strength at 25 ° C. before radiation irradiation−after radiation irradiation). (Tack strength at 25 ° C.) is 0.1 N / 5.1 mmΦ probe or more, and (D2) storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is An adhesive sheet having a pressure of 100 MPa or less may be used.
In the seventh and eighth aspects, from the viewpoint of controlling the fluidity of the adhesive layer, an adhesive sheet having the property (D1) is used, and when the adhesive sheet is laminated on a semiconductor wafer, sufficient adhesive force is obtained. From the viewpoint of having sufficient adhesiveness at a temperature of 200 ° C. or less when a semiconductor element is bonded, an adhesive sheet having the characteristic (D2) is used. Further, in the adhesive sheet, from the viewpoint of achieving good workability at the time of dicing and at the time of pick-up, from the viewpoint, the adhesive strength ratio at the interface between the adhesive layer and the base material layer before and after radiation irradiation (adhesion after radiation irradiation) Strength / adhesive strength before irradiation) is preferably 0.5 or less. Further, from the viewpoint of achieving better workability at the time of dicing and at the time of pickup, the adhesive strength of the adhesive sheet before irradiation with radiation at the interface between the adhesive layer and the base material layer is 200 mN /. cm or more, and the adhesive strength after radiation irradiation is preferably 100 mN / cm or less.
In the adhesive sheet, the difference in tack strength at 25 ° C. of the adhesive layer before and after irradiation (tack strength at 25 ° C. before irradiation—tack strength at 25 ° C. after irradiation) was determined for each element. It is characterized by being 0.1 N / 5.1 mmΦ probe or more, preferably 0.15 N / 5.1 mmΦ probe or more, and 0.2 N / 5.1 mmΦ probe or more, in that pickup becomes possible without damage. Is more preferred.
In the adhesive sheet, the tack strength at 25 ° C. of the adhesive layer before radiation irradiation is 0.5 N / 5.1 mmΦ probe or more, and the tack strength of the adhesive layer at 25 ° C. after radiation irradiation. Is preferably 0.4 N / 5.1 mmΦ probe or less. If the tack strength of the adhesive layer before irradiation at 25 ° C. is less than the 0.5N / 5.1 mmφ probe, the semiconductor elements may be scattered during dicing. On the other hand, if the tack strength at 25 ° C. of the adhesive layer after irradiation is larger than that of the 0.4N / 5.1 mmφ probe, each element tends to be damaged during pickup.
In the fifth to eighth aspects described above, the adhesive strength before irradiation (at the time of dicing) is preferably 200 mN / cm or more in that the semiconductor element can be prevented from scattering at the time of dicing. , 250 mN / cm or more, more preferably 300 mN / cm or more, and most preferably 350 mN / cm or more. There is no particular upper limit since the higher the adhesive strength, the more the semiconductor elements can be prevented from scattering. However, materials that can be easily obtained and those that can be manufactured by an appropriate manufacturing process are usually 25,000 mN / cm or less, and 10,000 mN / cm or less. Are relatively easy to manufacture. Further, in order not to damage each element at the time of pickup, it is preferable that the adhesive strength after radiation irradiation is 100 mN / cm or less. However, when bonding to a relatively thick semiconductor wafer, the thickness may be more than this. 100 mN / cm or less is a value that can be applied to a semiconductor wafer of any thickness (for example, an extremely thin semiconductor wafer having a thickness of 20 μm) as long as it is less than 100 mN / cm.
Examples of the (C1) method of increasing the difference in adhesive strength before and after radiation irradiation or the (C2) method of increasing the tack strength before and after radiation irradiation include, for example, thermoplastic resin, thermosetting resin, and radiation irradiation. This can be achieved by increasing the use ratio of the thermosetting resin and the compound that generates a base in the adhesive layer containing a compound that generates a base as an essential component. However, when the difference in the adhesive strength and the difference in the tack strength are increased, the ratio of the flow amount before and after the radiation irradiation and the ratio of the melt viscosity tend to increase at the same time. It is preferable to determine the use ratio of the compound that generates a base.
As a method of increasing tan δ at 120 ° C. before irradiation and tan δ at 180 ° C. after irradiation, or as a method of decreasing the storage elastic modulus at 120 ° C. before irradiation and the storage elasticity at 180 ° C. after irradiation. A known method may be used to increase the fluidity of the adhesive layer. Specifically, for example, addition of a diluent, use of a thermoplastic resin having a lower Tg, or use of a thermosetting resin and a curing agent having a lower Tg can be mentioned. If the material is selected so that the Tg of the entire adhesive layer is about 120 ° C. before irradiation and about 180 ° C. after irradiation, the subsequent optimization becomes easy.
(Ninth Aspect) Further, as one aspect of the present invention, an adhesive layer and a base layer are provided, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive sheet, wherein the adhesive layer, in an uncured or semi-cured state, has a storage elastic modulus at 50 ° C. of 0.1 MPa or more and 200 MPa or less, and after irradiation with a certain amount of radiation. An adhesive sheet having a storage elastic modulus at 50 ° C. of at least twice that before irradiation and a flow amount at 160 ° C. after irradiation of a certain amount of radiation of 100 μm to 10,000 μm is exemplified.
(Tenth Aspect) Further, as one aspect of the present invention, an adhesive layer and a base layer are provided, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive sheet, wherein the adhesive layer, in an uncured or semi-cured state, has a storage elastic modulus at 50 ° C. of 0.1 MPa or more and 200 MPa or less, and after irradiation with a certain amount of radiation. The storage elastic modulus at 50 ° C. is twice or more that before irradiation, and the melt viscosity at 160 ° C. is 50 Pa · s or more and 10 or more. ⁶ An adhesive sheet having a Pa · s or less is given.
(Eleventh aspect) Further, as one aspect of the present invention, an adhesive layer and a substrate layer are provided, and the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation. The adhesive sheet, wherein the adhesive layer, in an uncured or semi-cured state, has a storage elastic modulus at 50 ° C. of 0.1 MPa or more and 200 MPa or less, and after irradiation with a certain amount of radiation. An adhesive sheet having a storage elastic modulus at 50 ° C. of at least twice that before irradiation and a storage elastic modulus at 180 ° C. of 100 MPa or less is exemplified.
In the adhesive sheets of the ninth, tenth, and eleventh aspects, the storage elastic modulus at 50 ° C. of the uncured or semi-cured adhesive sheet needs to be 0.1 to 200 MPa. 0.5 to 150 MPa is preferable, 1.0 to 100 MPa is more preferable, and 2 to 50 MPa is particularly preferable. If the storage modulus is less than 0.1 MPa, the semiconductor element is likely to be damaged during dicing, which is not suitable. If it is more than 200 MPa, lamination with a wafer cannot be performed, which is inappropriate. The case of 2 to 50 MPa is preferred in that both the dicing property and the laminating property with the wafer are the best.
Further, the storage elastic modulus at 50 ° C. of the adhesive sheet irradiated with a certain amount of radiation must be at least twice that before irradiation, and if it is less than twice, the semiconductor element is peeled off from the base film after irradiation. It is not preferable because it is difficult to perform. It is more preferably at least 4 times, particularly preferably at least 10 times, in that a thin semiconductor element or the like can be easily peeled off from the substrate film.
In the adhesive sheet of one embodiment of the present invention, the flow rate at 160 ° C. of the adhesive sheet after irradiating a fixed amount of radiation to the uncured or semi-cured adhesive sheet needs to be in a range of 100 μm or more and 10,000 μm. It is. When the flow amount is less than 100 μm, the fluidity and wettability during the pressure bonding of the semiconductor element are insufficient, and the adhesiveness is unfavorably reduced. When the flow amount is more than 10000 μm, the resin excessively flows out from the end of the semiconductor element when the semiconductor element is pressed, thereby covering the electrode terminal portion of the support member of the semiconductor element and making a process such as wire bonding difficult. In addition, since the thickness of the adhesive sheet is reduced, the adhesiveness is not preferable.
The flow amount is preferably in the range of 100 μm or more and 6000 μm or less from the viewpoint that the outflow of the resin from the end of the semiconductor element is smaller. When a tape with a circuit or a substrate with a circuit is used as a support member for a semiconductor element, the flow amount is in the range of 1000 μm to 4000 μm in that the circuit filling property is high and the resin flows out from the end portion is small. Is preferred.
When the flow amount A of the uncured or semi-cured adhesive sheet at 160 ° C. and the flow amount B after irradiating the adhesive sheet with a certain amount of radiation satisfy the relationship of B / A ≧ 1/10, radiation irradiation is performed. Even if there is some variation in the amount and condition, it is preferable in that the variation in the flow amount after irradiation is small. Further, the point B / A ≧ 1/5 where the variation of the flow amount after irradiation is smaller is more preferable, and B / A ≧ 1/2 is most preferable.
In the adhesive sheet of one embodiment of the present invention, the melt viscosity at 160 ° C. after irradiating a fixed amount of radiation to the adhesive layer needs to be 50 to 100000 Pa · s. When the melt viscosity is less than 50 Pa · s, the fluidity is excessive, the outflow of the resin from the end is large, and the thickness of the adhesive sheet is reduced, so that the adhesiveness tends to be reduced. . On the other hand, when it is more than 100,000 Pa · s, the fluidity is low, and the adhesiveness and the circuit filling property tend to decrease.
Further, when the storage elastic modulus at 50 ° C. after irradiating a fixed amount of radiation to the uncured or semi-cured adhesive sheet is 15 MPa or more, a thin semiconductor element or the like can be easily peeled off from the base film. Is particularly preferred.
Furthermore, the storage elastic modulus at 100 ° C. of the uncured or semi-cured adhesive sheet is 0.0001 to 2 MPa in that it can be laminated at a low temperature, and the storage elastic modulus at 50 ° C. in terms of easy dicing. 0.1 to 200 MPa, storage irradiation modulus at 50 ° C. is 15 to 200 MPa after radiation irradiation in that it is easily peeled, and storage elastic modulus at 180 ° C. is 100 MPa or less at high fluidity point. It is particularly preferable that the storage elastic modulus at 50 ° C. after curing is 100 to 5000 MPa after curing in terms of good heat resistance. The storage elastic modulus at 50 ° C. of the uncured or semi-cured adhesive sheet is preferably from 5 to 100 MPa, more preferably from 7.5 to 50 MPa, from the viewpoint of further excellent dicing workability.
In the adhesive sheet of one embodiment of the present invention, when the adhesive layer is heated and cured, the storage elastic modulus is preferably 10 to 2000 MPa at 25 ° C, and 3 to 50 MPa at 260 ° C. The storage elastic modulus at 25 ° C is more preferably from 20 to 1900 MPa, particularly preferably from 50 to 1800 MPa. The storage elastic modulus at 260 ° C. is more preferably 4 to 50 MPa, and particularly preferably 5 to 50 MPa. When the storage elastic modulus is in this range, the effect of relaxing the thermal stress generated by the difference in the coefficient of thermal expansion between the semiconductor element and the support member is maintained, and the occurrence of peeling and cracks can be suppressed, and the handling property of the adhesive can be reduced. The thickness accuracy of the adhesive layer and the occurrence of reflow cracks can be suppressed.
The storage elastic modulus of the adhesive layer at the stage of the heat curing is, for example, by increasing the amount of epoxy resin used, or by using an epoxy resin having a high glycidyl group concentration or a phenol resin having a high hydroxyl group concentration, for example, as a whole polymer. By increasing the crosslink density of the polymer. Obviously, if the reverse procedure is taken, the value of the storage modulus also decreases.
In the adhesive sheet of one embodiment of the present invention, the adhesive strength (pull strength) at 250 ° C. of a cured laminate obtained by bonding a 5 mm-square semiconductor element and a support member to each other via the adhesive layer of the adhesive sheet after irradiation is obtained. The peel strength is preferably 3.0 N / chip or more. The peeling method between the semiconductor element and the support member is roughly classified into interface failure in which the adhesive layer and the support member peel off and cohesive failure in which the adhesive layer breaks and peels. . It is effective to increase the fluidity of the adhesive layer or to increase the flow rate of the adhesive layer after radiation irradiation in order to suppress interface destruction. It is effective to select a material so as to increase the crosslink density of the adhesive layer, to increase the molecular weight of the thermoplastic resin, and to set the elastic modulus at 260 ° C. in the range of 0.01 to 50 MPa.
Although described with reference to some specific embodiments as described above, the above-mentioned various properties are effective properties for obtaining a better adhesive sheet. Needless to say, a sheet can be obtained.
(Adjustment of curing degree)
Adhesive sheet as one embodiment of the present invention, when the adhesive layer contains a thermoplastic resin and a thermosetting resin as a main component, when the adhesive sheet is irradiated with radiation adhesive When the calorific value by DSC of the layer is A, and the calorific value before irradiation is B, it is preferable to have a configuration in which (BA) /B=0.1 to 0.7.
In the adhesive sheet, when the amount of heat generated by the DSC of the adhesive layer when irradiated with radiation is A, and the amount of heat generated before irradiation is B, (B−A) /B=0.1 to 0. 7 is preferred, and more preferably 0.2 to 0.5. In order not to damage the semiconductor element at the time of pickup after irradiation, it is preferably 0.1 or more. When the semiconductor element is heated and adhered to the supporting member via the adhesive layer after the pickup, it is preferably 0.7 or more in order to secure sufficient fluidity.
Note that the calorific value by the DSC is measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (also referred to as “DSC” in this specification) as described later in the section of the evaluation method. It is a value obtained when measured under conditions of a temperature of 20 ° C to 300 ° C.
Further, the adhesive layer contains a photoreactive compound which promotes a curing reaction of the thermosetting resin by irradiation with radiation. Further, the photoreactive compound is a compound that generates a base upon irradiation with radiation having a wavelength of 150 to 750 nm.
The compound that generates a base upon irradiation with radiation is not particularly limited as long as it is a compound that generates a base upon irradiation with radiation. The base to be generated is preferably a strongly basic compound from the viewpoint of reactivity and curing rate. Generally, a pKa value which is a logarithm of an acid dissociation constant is used as an index of basicity, and a base having a pKa value in an aqueous solution of 7 or more is preferable, and a base of 9 or more is more preferable. Examples of the photobase generator to be used are as described above.
In the adhesive sheet, the Tg of the thermoplastic resin used is −50 to 10 ° C., and the weight average molecular weight is 100,000 to 1,000,000. When the Tg is lower than -50 ° C, the self-supporting property of the pressure-sensitive adhesive layer is lost, and there is a problem in handleability. When the Tg is higher than 10 ° C, the temperature required for bonding increases, and both are not preferred. (Note that Tg in the present invention indicates a value measured using a DSC as described later in the section of the evaluation method.) When the weight average molecular weight is in this range, when the sheet or film is formed, The strength, flexibility and tackiness of the wire are appropriate, and the flowability is appropriate, so that a good circuit filling property of the wiring can be secured. If the weight average molecular weight is out of the above range, the above properties when formed into a sheet or a film are unfavorably impaired. In the present invention, the weight average molecular weight is measured by gel permeation chromatography (also referred to as “GPC” in the present specification) as described later in the section of the evaluation method, and a standard polystyrene calibration curve is used. Indicates the converted value.
In the adhesive sheet, the thermoplastic resin used has a Tg of 10 to 100C and a weight average molecular weight of 5,000 to 200,000. The above Tg is more preferably 10 to 80 ° C. If the Tg is lower than 10 ° C., the self-supporting property of the pressure-sensitive adhesive layer is lost, and a problem arises in handleability. If the Tg is higher than 100 ° C., the temperature required for bonding increases, which is not preferable. In the present invention, Tg indicates a value obtained by DSC. The weight average molecular weight is more preferably from 20,000 to 150,000, and still more preferably from 20,000 to 80,000. When the weight average molecular weight is in this range, the strength, flexibility, and tackiness when formed into a sheet or film are appropriate, and since the flowability is appropriate, a good circuit filling property of the wiring is secured. it can. If the weight average molecular weight is out of the above range, the above properties when formed into a sheet or a film are unfavorably impaired. The weight average molecular weight is a value measured by gel permeation chromatography and converted using a standard polystyrene calibration curve.
(Chemical Structure of Adhesive Layer) The chemical structural aspect of the adhesive layer for further optimizing the adhesive sheet of the present invention having the above-described functions and effects of simplifying the working process. As a result, the present inventors have found that the above-mentioned effects can be more suitably obtained by forming an adhesive layer having characteristics as described below.
That is, the adhesive sheet as one embodiment of the present invention and the resin composition constituting the same are a sea-island phase-separated resin that does not have a crosslinked network structure before irradiation and heating, and a resin that forms a crosslinked network structure by irradiation. It is preferable to have an island phase composed of a resin and a sea phase composed of a resin that does not form a crosslinked network structure by irradiation but forms a crosslinked structure by heating.
In order to impart adhesiveness in the B-stage state, it is preferable that the resin does not have a crosslinked network structure before irradiation. Furthermore, as a result of examining the molecular structure after irradiation, when the sea phase forms a network structure, the flowability decreases, the adhesiveness tends to decrease, and when the island phase does not form a network structure, It was found that there was a tendency that the adhesiveness was high and the peeling was difficult. That is, when the adhesive sheet is irradiated with radiation, it is preferable that the island phase forms a crosslinked network structure in terms of adhesiveness, while the sea phase facilitates peeling of the adhesive layer from the base material layer. It is preferable not to form a crosslinked network at this point.
After radiation irradiation and heat curing, it is necessary that both the sea phase and the island phase have a crosslinked network structure in order to impart heat resistance. Regarding the sea-island structure, the cross section of the sample was observed by SEM, and the dispersed part was determined as an island phase, and the continuous phase was determined as an island phase. The radiation dose and the wavelength are adjusted so that the above-mentioned effects are exhibited.
The formation of the crosslinked network structure of each phase was determined as follows. That is, a sample (weight Xg) was permeated into 10 g of MEK at 25 ° C. for 1 hour, and insoluble materials were removed with a 200-mesh nylon cloth. The filtered material (dissolved component) was dried at 170 ° C. for 1 hour, the weight Y was measured, and the dissolved component ratio (%) was determined from the initial sample and the weight ratio Y / X × 100 (%). When the ratio of the dissolved component was less than 80%, a network structure was formed and an insoluble portion was formed. Therefore, it was determined that the sea phase formed a crosslinked network structure. In addition, when the ratio of the dissolved components is 80% or more, and those having a visible light transmittance of 80% or more in a cell having a thickness of 5 mm of the filtrate are judged to have a crosslinked network structure in both the sea phase and the island phase. did. When the filtrate had a visible light transmittance of less than 80% in a cell having a thickness of 5 mm, the sea phase was determined not to have a crosslinked network structure, but the island phase was determined to have a crosslinked network structure.
The combination of the resin that forms the sea-island structure having the above characteristics by irradiation with radiation includes, for example, a combination of a high-molecular-weight component and a low-molecular-weight thermosetting component that is compatible with the high-molecular-weight component. The combination of a glycidyl group-containing (meth) acrylic copolymer and an epoxy resin is preferred in terms of excellent adhesiveness.
The adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) at the interface between the adhesive layer and the base material layer before and after the irradiation by the 90 ° peeling force is 0.5 or less and 0.4 or less. More preferably, it is even more preferably 0.3 or less. If this value is larger than 0.5, each element tends to be damaged during pickup. On the other hand, the lower limit of the adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) is not particularly limited, but is preferably 0.0001 or more from the viewpoint of workability, for example. The adhesive force between the adhesive layer and the base material layer at the time of dicing (before radiation irradiation) is determined by applying the adhesive sheet to a semiconductor wafer to be diced by pressing the adhesive sheet at room temperature or while heating. It can be measured by the peeling force when only the base material layer is pulled at a pulling angle of 90 ° and a pulling speed of 50 mm / min.
In the adhesive sheet, a difference in adhesive strength (adhesive strength before irradiation-adhesive strength after irradiation) due to the 90 ° peeling force at the interface between the adhesive layer and the base material layer before and after radiation irradiation is 100 mN / cm or more, It is more preferably at least 150 mN / cm, further preferably at least 200 mN / cm, most preferably at least 250 mN / cm. If this value is less than 100 mN / cm, each element tends to be damaged during pickup.
After irradiating a fixed amount of radiation to the uncured or semi-cured adhesive sheet, the flow rate of the adhesive sheet at 160 ° C. is preferably in the range of 100 μm or more and 10,000 μm.
<Production method>
The adhesive sheet of the present invention can be obtained by dissolving or dispersing the composition for forming the adhesive sheet in a solvent to form a varnish, applying the composition on a base film, heating and removing the solvent.
After the dicing step, the adhesive sheet of the present invention irradiates the adhesive sheet with an actinic ray having a wavelength range of 150 to 750 nm, polymerizes and cures the radiation-polymerizable adhesive sheet, and provides an adhesive force between the adhesive sheet and the substrate interface. To make it possible to pick up a semiconductor element.
The solvent for forming the varnish is not particularly limited, but in consideration of volatility at the time of 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. For the purpose of improving the coating properties, for example, a solvent having a relatively high boiling point, such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, and cyclohexanone, can be used. These solvents can be used alone or in combination of two or more.
In the production of the varnish when the inorganic filler is added, it is preferable to use a mill, a three-roll mill, a ball mill, a bead mill, or the like, in consideration of the dispersibility of the inorganic filler, or a combination of these. You can also. In addition, by mixing the inorganic filler and the low-molecular-weight raw material in advance and then blending the high-molecular-weight raw material, the mixing time can be shortened. After the varnish is formed, bubbles in the varnish can be removed by vacuum degassing or the like.
As a method for applying the varnish to the substrate 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, a curtain coating method, and the like. .
The thickness of the adhesive sheet is not particularly limited, but is preferably 5 to 250 μm for both the adhesive layer and the base 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.
Further, the adhesive sheet of the present invention is further provided with one or more adhesive layers or adhesive layers so as to be sandwiched between the semiconductor wafer and the adhesive layer in order to obtain a desired sheet thickness. You may. 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 optional adhesive layer, a commercially available adhesive sheet, for example, a polyimide-based, silicon oligomer-based, rubber-epoxy, or epoxy-based adhesive can be used. However, it is necessary to consider bonding conditions that do not cause peeling between the adhesive layers based on a conventionally known technique.
<How to use>
When the adhesive sheet having the configuration described above is irradiated with radiation, the adhesive force of the adhesive layer to the base material layer is significantly reduced after the irradiation. Therefore, as described later, by using the adhesive sheet of the present invention in the dicing step in manufacturing a semiconductor device, the adhesive layer and the base material layer are easily peeled off. A semiconductor element provided with the adhesive layer can be suitably picked up.
The radiation irradiated in the present invention is active light having a wavelength range of 150 to 750 nm, and includes ultraviolet light, far ultraviolet light, near ultraviolet light, visible light, electron beam, infrared light, and near infrared light. For example, using a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, and a metal halide lamp, 0.01 to 10,000 J / cm. ² Can be irradiated.
It is considered that since the radiation irradiation cures a part of the thermopolymerizable resin contained in the adhesive layer, the adhesive strength between the adhesive layer and the base material layer is reduced. When a sufficient decrease in adhesive strength cannot be obtained only by the irradiation of the radiation, it is preferable to accelerate the curing reaction by heating in addition. The heating temperature varies depending on the progress of the curing reaction by irradiation with radiation and also depends on the composition of the adhesive layer, but it is sufficient that the adhesive sheet is usually exposed to an atmosphere at 30 to 100 ° C. For the heating, a heater or an oven may be used, but a general radiation irradiation source often generates heat at the time of irradiation, and it is preferable to use this heat generation because it is not necessary to separately prepare a heating device.
In addition, the adhesive force between the adhesive layer and the base material layer interface after irradiation of the radiation of the present invention is, for example, after bonding the adhesive sheet to a semiconductor wafer to be diced at room temperature or by heating and bonding. The peeling force (adhesive strength) when only the substrate layer is pulled at a pulling angle of 90 ° and a pulling speed of 50 mm / min is 100 mN / cm or less, more preferably 90 mN / cm or more, More preferably, it is 80 mN / cm or more. If this value exceeds 100 mN / cm, each element tends to be damaged during pickup.
Next, a method of using the adhesive sheet according to the present invention will be described with reference to FIGS. 1 to 8, but it goes without saying that the method of using the present invention is not limited to the following method. In the drawings, components having the same function are denoted by the same reference numerals, and description thereof is omitted.
FIG. 1 discloses an adhesive sheet 10 including a base film 1 and a first adhesive layer 2. FIG. 2 shows a second adhesive layer 3 in addition to the above-mentioned constituent elements. Is disclosed.
When these adhesive sheets 10 and 20 are used as a dicing tape, first, they are placed on a predetermined workbench such that the adhesive layers 2 and 3 of the adhesive sheets 10 and 20 are brought into close contact with the wafer surface.
In the case where a peelable sheet is provided on the upper surface of the adhesive sheet according to the present invention, the peelable sheet is peeled and removed, and the adhesive layer 2, 3 of the adhesive sheet is turned upward to a predetermined position. On the workbench.
Next, as shown in FIG. 3, a semiconductor wafer A to be diced is attached to the upper surface of the second adhesive layer 3. At this time, as described above, one or more adhesive layers or adhesive layers are further sandwiched between the semiconductor wafer A and the second adhesive layer 3 in order to obtain a desired sheet thickness. It may be provided as follows.
Subsequently, dicing, washing, and drying steps are added to the semiconductor wafer A in this bonded state. At this time, the semiconductor wafer A is sufficiently adhered and held to the adhesive sheet by the second adhesive layer 3, so that the semiconductor wafer A does not fall off during each of the above steps.
FIG. 4 shows that dicing of the wafer A with the dicing cutter 6 provides cuts indicated by thick lines, and semiconductor elements A1, A2, and A3 are obtained.
Next, as shown in FIG. 5, radiation B is applied to the adhesive layers 2 and 3 of the adhesive sheet, and a part or most of the radiation-polymerizable adhesive sheet is polymerized and cured. At this time, heating may be used in combination with radiation irradiation or for the purpose of accelerating the curing reaction after radiation irradiation. The combined use of heating makes it possible to lower the adhesive strength at a lower temperature in a shorter time. The heating temperature is not particularly limited as long as it is equal to or lower than the thermal decomposition temperature of the adhesive layer, but a temperature of 50 to 170C is preferable.
Irradiation to the adhesive sheet is performed from the surface of the base film 1 on which the adhesive layer 2 is not provided, as indicated by an arrow B in FIG. Therefore, as described above, when using UV as radiation, the base film 1 needs to be light-transmitting, but when using EB as radiation, the base film 1 is not necessarily light-transmitting. No need.
After the irradiation, the semiconductor elements A1, A2 and A3 to be picked up are picked up by the suction collet 4, for example, as shown in FIG. 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 rod or the like, instead of or in combination with the suction collet 4.
Since the adhesive force between the semiconductor element A1 and the adhesive layer 3 is greater 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 is peeled off while adhering to the lower surface of the semiconductor element A1 (see FIG. 7).
Next, the semiconductor elements A1, A2, and A3 are placed on the semiconductor element mounting support member 5 via the adhesive layer 2, and heated. By the heating, the adhesive layer 2 develops an adhesive force, and the bonding between the semiconductor elements A1, A2, A3 and the semiconductor element mounting support member 5 is completed (see FIG. 8).
After the dicing step, the adhesive sheet of the present invention is irradiated with radiation such as ultraviolet rays (UV) or electron beams (EB) to polymerize and cure the radiation-polymerizable adhesive sheet. This is to reduce the adhesive force between the (layer) and the interface of the base film to enable the pickup of the semiconductor element. In the case of a conventional adhesive sheet, if the surface tension of the substrate exceeds 40 mN / m, the adhesive force between the adhesive sheet and the substrate interface is not sufficiently reduced, and the pickup property tends to be poor. However, even if the surface tension of the base material exceeds 40 mN / m, the adhesive force of the adhesive sheet and the base material interface after irradiation with radiation such as ultraviolet (UV) or electron beam (EB) can be obtained. The temperature is sufficiently reduced, and the pickup of the semiconductor element is improved. Therefore, conventionally, the substrate film used was subjected to a surface treatment in order to make the surface tension of the substrate 40 mN / m or less. However, in the adhesive sheet of the present invention, it is necessary to perform the surface treatment on the substrate film. It is also advantageous in terms of cost.
Although the present invention has been described above, a preferred embodiment of the adhesive sheet of the present invention further includes the following adhesive sheet.
(Twelfth aspect)
As a preferred embodiment of the adhesive sheet of the present invention, the adhesive sheet includes an adhesive layer and a base layer, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. An adhesive sheet, wherein the adhesive layer comprises 10 to 400 parts by weight of a high molecular weight component containing a functional monomer and having a weight average molecular weight of 100,000 or more, (b) 100 parts by weight of a thermopolymerizable component, And (c) a compound capable of generating a base upon irradiation with radiation. An adhesive sheet containing 0.01 to 200 parts by weight of a radiation polymerizable compound. (Thirteenth aspect)
In a preferred embodiment of the adhesive sheet of the present invention, the adhesive sheet includes an adhesive layer and a base layer, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. Wherein the adhesive layer comprises 100 parts by weight of a polyimide resin, 1 to 200 parts by weight of a (b) thermopolymerizable component, and (c) a compound that generates a base upon irradiation with radiation. An adhesive sheet containing 0.01 to 200 parts by weight is exemplified.
Here, in the twelfth and thirteenth aspects, it is preferable to use an epoxy resin and an epoxy resin curing agent as the thermopolymerizable component from the viewpoint of workability and heat resistance. (14th aspect)
One embodiment of the present invention is an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive layer (A2) has a tack strength of 0.5 N or more at 25 ° C. by a 5.1 mmφ probe measurement before the radiation irradiation, and (B1) the radiation irradiation An adhesive sheet having a flow amount at 160 ° C. of 100 to 10,000 μm before is exemplified. (15th aspect)
According to another embodiment of the present invention, there is provided an adhesive sheet including an adhesive layer and a base layer, wherein the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive layer has a tack strength of not less than 0.5 N at 25 ° C. measured by a 5.1 mmφ probe measurement before irradiation with (A2) radiation, and (B2) irradiation with radiation. An adhesive sheet having a melt viscosity at 160 ° C. of 50 to 100000 Pa · s before is exemplified.
(Sixteenth aspect)
Furthermore, as a preferred embodiment of the adhesive sheet of the present invention, the adhesive sheet includes an adhesive layer and a base layer, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive sheet according to claim 1, wherein the adhesive layer comprises: (C1) an adhesive strength difference between the adhesive layer / base layer interface before and after irradiation (adhesive strength before irradiation−adhesion after irradiation). (Strength) is 100 mN / cm or more, and at least one of the following properties.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less.
Here, from the viewpoint of controlling the fluidity of the adhesive layer, an adhesive sheet having the property (D1) is used. When the adhesive sheet is laminated on a semiconductor wafer, the adhesive sheet has a sufficient adhesive force, and the semiconductor element is From the viewpoint of having sufficient adhesiveness at a temperature of 200 ° C. or less when bonded, an adhesive sheet having the property (D2) is used.
(Seventeenth aspect)
Furthermore, as a preferred embodiment of the adhesive sheet of the present invention, the adhesive sheet includes an adhesive layer and a base layer, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive sheet according to claim 1, wherein the adhesive layer comprises (C2) a difference in tack strength at 25 ° C. between before and after irradiation (tack strength at 25 ° C. before irradiation—after irradiation). Adhesive sheet having a tack strength at 25 ° C. of 0.1 N / 5.1 mmφ probe or more and having at least one of the following characteristics.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less.
Here, from the viewpoint of controlling the fluidity of the adhesive layer, an adhesive sheet having the property (D1) is used. When the adhesive sheet is laminated on a semiconductor wafer, the adhesive sheet has a sufficient adhesive force, and the semiconductor element is From the viewpoint of having sufficient adhesiveness at a temperature of 200 ° C. or less when bonded, an adhesive sheet having the property (D2) is used.
(Eighteenth aspect)
In a preferred embodiment of the adhesive sheet of the present invention, the adhesive sheet includes an adhesive layer and a base layer, and the adhesive force between the adhesive layer and the base layer is controlled by irradiation with radiation. The adhesive sheet, wherein in the adhesive sheet, the adhesive layer has an uncured or semi-cured storage elastic modulus at 50 ° C. of 0.1 MPa or more and 200 MPa or less, and emits a certain amount of radiation. After the irradiation, the storage elastic modulus at 50 ° C. is twice or more that before the irradiation, and the adhesive layer after the irradiation of a certain amount of radiation has the following (E), (F) and (G) It is preferable to have at least one of the characteristics described in (1).
(E) a flow rate at 160 ° C. of 100 μm or more and 10,000 μm or less;
(F) a melt viscosity at 160 ° C. of 50 Pa · s or more and 10 ⁶ Pa · s or less, and
(G) Storage elastic modulus at 180 ° C. is 100 MPa or less
(Nineteenth aspect)
Furthermore, as a preferred embodiment of the adhesive sheet of the present invention, the adhesive sheet includes a pressure-sensitive adhesive layer and a base layer, and the adhesive force between the pressure-sensitive adhesive layer and the base layer is irradiated with radiation. The adhesive sheet to be controlled, wherein the adhesive layer (A1) has an adhesive strength of 200 mN / cm or more at an interface between the adhesive layer and the base material layer before irradiation, and Adhesive sheet having at least one of the above characteristics.
(B1) a flow amount at 160 ° C. before irradiation is 100 to 10,000 μm;
(B2) melt viscosity at 160 ° C. before irradiation is 50 to 100000 Pa · s
Here, an adhesive sheet having the characteristic (B1) is used from the viewpoint of dicing workability, and an adhesive sheet having the characteristic (B2) is used from the viewpoint of adhesiveness. Further, in the adhesive sheet, a flow amount ratio before and after radiation irradiation (flow amount after irradiation / flow amount before irradiation) is preferably 0.1 or more. Further, in the adhesive sheet, it is preferable that an adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) of the interface between the adhesive layer and the base material layer before and after radiation is 0.5 or less. Further, in the adhesive sheet, it is preferable that a difference in adhesive strength between the adhesive layer and the base material layer before and after radiation irradiation (adhesive strength before irradiation-adhesive strength after irradiation) is 100 mN / cm or more. Furthermore, in the adhesive sheet, it is preferable that a melt viscosity ratio before and after irradiation (melt viscosity after irradiation / melt viscosity before irradiation) is 100 or less.
(20th aspect)
Further, as a preferred embodiment of the adhesive sheet of the present invention, comprises an adhesive layer and a substrate layer, the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation An adhesive sheet, wherein the adhesive layer has a storage elastic modulus at 50 ° C. in an uncured or semi-cured state of 0.1 MPa or more and 200 MPa or less, and is exposed to a certain amount of radiation at 50 ° C. The adhesive layer having a storage elastic modulus of 2 times or more before irradiation and having been irradiated with a certain amount of radiation has the following characteristics (E), (F) and (G): Among them, an adhesive sheet having at least one property is exemplified.
(E) a flow rate at 160 ° C. of 100 μm or more and 10,000 μm or less;
(F) a melt viscosity at 160 ° C. of 50 Pa · s or more and 10 ⁶ Pa · s or less, and
(G) The storage elastic modulus at 180 ° C. is 100 MPa or less.
Further, in the adhesive sheet, a flow amount A at 160 ° C. of the adhesive layer of the uncured or semi-cured adhesive sheet at a temperature of 160 ° C. and a certain amount of radiation are applied to the adhesive sheet from the viewpoint of obtaining good adhesiveness. It is preferable that the flow amount B of the adhesive layer after the satisfies the relationship of B / A ≧ 1/10. Further, the storage elastic modulus at 50 ° C. of the adhesive layer after irradiating a fixed amount of radiation to the uncured or semi-cured adhesive sheet is preferably 15 MPa or more. Further, it is preferable that the adhesive layer satisfies the following conditions.
1) The storage elastic modulus at 100 ° C. in an uncured or semi-cured state is 0.001 MPa or more and 2 MPa or less; 2) The storage elastic modulus at 50 ° C. is 7.5 MPa or more and 50 MPa or less; 3) After irradiation The storage elastic modulus at 50 ° C. is from 15 MPa to 100 MPa, and 4) the storage elastic modulus at 50 ° C. after curing is from 100 MPa to 5000 MPa. Furthermore, it is preferable that the adhesive strength at 250 ° C. of the laminated cured product of the 5 mm square semiconductor element and the support member using the adhesive layer of the adhesive sheet after irradiation with radiation is 3.0 N / chip or more. . The storage elastic modulus of the adhesive layer of the adhesive sheet after heat curing, when measured using a dynamic viscoelasticity measuring device, is 10 MPa or more and 2,000 MPa or less at 25 ° C., and 3 MPa or more and 50 MPa or less at 260 ° C. Is preferred.
Further, as another aspect of the present invention, a method for manufacturing a semiconductor device and a semiconductor device as described below are provided.
A method for manufacturing a semiconductor device, wherein a semiconductor element and a supporting member for mounting a semiconductor element or a semiconductor element are bonded to each other using the adhesive sheet of the present invention.
Adhering the adhesive sheet of the present invention having an adhesive layer and a base material layer to a semiconductor wafer with the adhesive layer interposed therebetween; and dicing the semiconductor wafer with an adhesive layer. A step of forming a semiconductor element; a step of irradiating the adhesive sheet with radiation after dicing to cure the adhesive layer and then peeling off the base film layer; Bonding a semiconductor device mounting support member or semiconductor elements to each other via the adhesive sheet.
A semiconductor device having a structure in which a semiconductor element and a supporting member for mounting a semiconductor element or a semiconductor element is bonded to each other using the adhesive sheet of the present invention.
Example
Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these. The evaluation of the adhesive sheet was performed according to the method described in the section of the evaluation method described later unless otherwise specified in each example.
(Synthesis Example 1) [Synthesis of photobase generator]
30 g of 2-nitrobenzyl alcohol was dissolved in 300 g of tetrahydrofuran by stirring at room temperature using a magnetic stirrer. A solution composed of 24.5 g of 4,4'-diphenylmethane diisocyanate and 100 g of tetrahydrofuran, which had been mixed in advance, was added dropwise to this solution over 30 minutes, and the mixture was stirred at room temperature for 1 hour. Thereafter, a Liebig condenser was set, and a reaction was performed for 2 hours while heating to 60 ° C. in an oil bath. After the reaction, the mixture was cooled to room temperature and concentrated using a rotary evaporator until the reaction liquid became half.
When the obtained concentrate was added to 1000 parts by weight of n-hexane, a white precipitate was obtained. This precipitate was filtered by suction and dried under vacuum at 60 ° C. overnight to obtain the desired 2-nitrobenzylcarbamic acid derivative (PB-1). The yield was 49.5 g (91% yield).
(Synthesis Example 2) [Synthesis of photobase generator]
Add p-nitrobenzoic acid methyl ester (2.00 g, 11 mmol), N, N-dimethylhydrazine (0.66 g, 11 mmol) and phenylglycidyl ether (1.66 g, 11 mmol) to tert-butanol (15.0 g). Then, after stirring at 50 ° C. for 10 hours, and further stirring at room temperature (25 ° C.) for 48 hours, a white precipitate was formed. After this was filtered off, it was washed twice with ethyl acetate and dried with a vacuum drier to obtain an amine imide (PB-2). The yield was 3.67 g, the yield was 85%, and the melting point was 146-147 ° C.
(Synthesis Example 3) [Synthesis of photobase generator]
p-Cyanobenzoic acid methyl ester (2.00 g, 12 mmol), N, N-dimethylhydrazine (0.75 g, 12 mmol), phenylglycidyl ether (1.86 g, 12 mmol) were added to tert-butanol (10 g), After stirring at 50 ° C. for 72 hours, the mixture was further stirred at room temperature for 48 hours. After tert-butanol was removed from the obtained reaction solution with a rotary evaporator, 10 g of ethyl acetate was added and recrystallization was performed to obtain a white amine imide (PB-3). The yield was 2.74 g, the yield was 65%, and the melting point was 148 to 149 ° C.
(Synthesis Example 4) [Synthesis of photobase generator]
A solution of 1-benzyl-2-methylimidazole (1.73 g, 10.5 mmol) in acetone (5 g) was dissolved in phenacyl bromide (2.00 g, 10.5 mmol) in acetone (20 g). Was slowly added, followed by stirring at room temperature (25 ° C.) for 2 hours, whereby white crystals were precipitated. This was filtered, washed twice with acetone, and dried under vacuum at 60 ° C. for 5 hours to obtain imidazolium bromide salt 1 (yield 3.54 g).
The above imidazole bromide salt 1 (2.00 g, 5.4 mmol) was dissolved in a methanol / water (15 g / 15 g) solution, and sodium tetraphenylborate (1.84 g) dissolved in water (5.0 g) was added thereto. , 5.4 mmol) was slowly added. With the addition, precipitation in the form of a white slurry was observed. After the addition, the mixture was further stirred at room temperature for 5 hours. The precipitate was filtered, dissolved in acetone (20 g) and recrystallized to obtain the desired imidazolium tetraphenylborate (PB-4) (yield 2.86 g). This compound ¹ H-NMR is shown in FIG. Further, the melting point and the thermal decomposition onset temperature in an oxygen atmosphere were measured by TG-DTA, and were found to be 187 ° C and 224 ° C.
(Synthesis Example 5) [Synthesis of photobase generator]
p-Nitrophenacyl bromide (2.00 g, 8.2 mmol) was dissolved in acetone (20 g), and 1,2-dimethylimidazole (0.79 g, 8.2 mmol) dissolved in acetone (5 g) was added thereto. The solution was added slowly, followed by stirring at room temperature for 2 hours, whereupon white crystals precipitated. This was filtered, washed twice with acetone, and then dried under vacuum at 60 ° C. for 5 hours to obtain imidazolium bromide salt 2 (yield 2.62 g).
The above imidazole bromide salt (2.00 g, 5.8 mmol) was dissolved in a methanol / water (15 g / 15 g) solution, and sodium tetraphenylborate (2.01 g) dissolved in water (5.0 g) was added thereto. 5.8 mmol) was added slowly. With the addition, precipitation in the form of a white slurry was observed. After the addition, the mixture was further stirred at room temperature for 5 hours. This was filtered, dissolved in acetone (20 g) and recrystallized to obtain the desired imidazolium tetraphenylborate (PB-5) (yield 2.83 g).
This compound ¹ H-NMR is shown in FIG. In addition, the melting point and the thermal decomposition onset temperature in an oxygen atmosphere were measured by TG-DTA, and the melting point was 165 ° C and the decomposition onset temperature was 195 ° C.
(Synthesis example 6) [Synthesis of polyimide resin]
In a 500 ml flask equipped with a thermometer, a stirrer and a 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 And stirred. After dissolution of the diamine, 52.2 g (0.1 mol) of 1,10- (decamethylene) bis (trimellitate anhydride) was added little by little while cooling the flask 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 with water. The reaction solution was poured into water, and the precipitated polymer was separated by filtration and dried to obtain a polyimide resin (PI-1).
(Synthesis Example 7) [Synthesis of polyimide resin]
In a 500 ml flask equipped with a thermometer, a stirrer and a calcium chloride tube, 5.41 g (0.045 mol) of 1,12-diaminododecane and 11.54 g of ether diamine (manufactured by BASF, ether diamine 2000 (molecular weight: 1923)) were added. 0.01 mol), 24.3 g (0.045 mol) of polysiloxane diamine (manufactured by Shin-Etsu Silicone, KF-8010 (molecular weight: 900)) and 169 g of N-methyl-2-pyrrolidone were charged and stirred. After dissolution of the diamine, 31.23 g (0.1 mol) of 4,4 ′-(4,4′-isopropylidenediphenoxy) bis (phthalic dianhydride) was added while cooling the flask in an ice bath. Were added. After reacting at room temperature for 8 hours, 112.7 g of xylene was added, and the mixture was heated at 180 ° C. while blowing in nitrogen gas to azeotropically remove xylene with water. The reaction solution was poured into water, and the precipitated polymer was separated by filtration and dried to obtain a polyimide resin (PI-2).
(Synthesis Example 8) [Synthesis of polyimide resin]
41.0 g (0.10 mol) of 2,2-bis (4- (4-aminophenoxy) phenyl) propane was placed in a 1-liter four-necked flask equipped with a stirrer, a nitrogen inlet tube, and a drying tube. Under a nitrogen stream, 250 g of N-methyl-2-pyrrolidone was added to form a solution. The flask was transferred to a water bath, and 41.0 g (0.10 mol) of 1,2- (ethylene) bis (trimellitate dianhydride) was added little by little with vigorous stirring. When the acid dianhydride was almost dissolved, the reaction was carried out for 6 hours while stirring slowly to obtain a polyamic acid solution. Next, a distillation apparatus was attached to the four-necked flask containing the polyamic acid solution, and 220 g of xylene was added. The condensed water generated by the imidization was azeotropically distilled off together with xylene with vigorous stirring on a 180 ° C. oil bath under a nitrogen stream. The reaction solution was poured into water, and the precipitated polymer was separated by filtration and dried to obtain a polyimide resin (PI-3).
Table 1 shows the compositions and physical properties of the obtained polyimide resins (PI-1 to PI-3). In addition, each physical property was measured on condition of the following.
(12) 'Tg
The measurement was carried out using a differential scanning calorimeter (hereinafter abbreviated as DSC) (manufactured by PerkinElmer Co., Ltd., DSC-7 type) at a heating rate of 10 ° C./min.
(13) 'weight average molecular weight
It was measured by gel permeation chromatography (hereinafter abbreviated as GPC) and converted into standard polystyrene.

The symbols in Table 1 indicate the following.
BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] propane DDO: 1,12-diaminododecane
EDA: ether diamine 2000 (molecular weight: 1923)
KF-8010: polysiloxane diamine (molecular weight: 900)
DBTA: 1,10- (decamethylene) bis (trimellitate anhydride)
BPADA: 4,4 '-(4,4'-isopropylidene diphenoxy) bis (phthalic dianhydride)
EBTA: 1,2- (ethylene) bis (trimellitate dianhydride)
Next, adhesive sheets 1 to 25 having the compositions shown in Tables 2 and 3 in Production Examples 1 to 25 were produced. The compositions of the adhesive sheets 1 to 25 are summarized in Tables 2 and 3.

(Production Example 1)
42.3 parts by weight of YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., o-cresol novolak type epoxy resin, epoxy equivalent: 210), phenolite LF2882 (trade name, manufactured by Dainippon Ink and Chemicals, bisphenol A novolak) 23.9 parts by weight, 44.1 parts by weight of HTR-860P-3 (trade name, manufactured by Nagase ChemteX Corp., epoxy group-containing acrylic rubber, molecular weight 1,000,000, Tg-7 ° C), Curezole 2PZ-CN ( 0.4 parts by weight of 1-cyanoethyl-2-phenylimidazole (trade name, manufactured by Shikoku Chemical Industry Co., Ltd.), NUC A-187 (trade name, γ-glycidoxypropyltrimethoxysilane, manufactured by Nippon Unicar Co., Ltd.) 0 0.7 parts by weight, and 0.5 parts by weight of a 2-nitrobenzylcarbamic acid derivative (PB-1), Stirring and mixing, and the mixture was deaerated under vacuum. This adhesive varnish was applied on a 50 μm-thick polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin Dupont Films Co., Ltd., surface tension: 50 dyne / cm), and dried by heating at 140 ° C. for 5 minutes. An adhesive sheet provided with a substrate (polyethylene terephthalate film) and having a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 1) was produced.
The storage elastic modulus when this adhesive sheet 1 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 360 MPa at 25 ° C. and 30 MPa at 260 ° C.
(Production Example 2)
In Production Example 1, 2-nitrobenzylcarbamic acid derivative (PB-1) was converted to 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (manufactured by Ciba Specialty Chemicals). Name: Irgacure 369) and the same operation as in Production Example 1 was carried out, and an adhesive sheet having a substrate (polyethylene terephthalate film) with a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (Adhesive sheet 2) was produced.
The storage elastic modulus when this adhesive sheet 2 is cured at 170 ° C. for 1 hour is measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of performing 80 μm, a temperature rise rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the pressure was 350 MPa at 25 ° C. and 25 MPa at 260 ° C.
(Production Example 3)
76.0 parts by weight of Denacol EX-411 (trade name, manufactured by Nagase ChemteX Corporation, aliphatic epoxy resin, 4-functional, epoxy equivalent: 231), phenolite LF2882 (trade name, manufactured by Dainippon Ink and Chemicals, bisphenol) A novolak resin) 39.0 parts by weight, HTR-860P-3) trade name, manufactured by Nagase ChemteX Corp., epoxy group-containing acrylic rubber, molecular weight 1,000,000, Tg-7 ° C) 76.7 parts by weight, Curesol 2PZ- 0.5 parts by weight of CN (trade name of Shikoku Chemical Industry Co., Ltd., 1-cyanoethyl-2-phenylimidazole), NUC A-187 (trade name of Nippon Unicar Co., Ltd., γ-glycidoxypropyltrimethoxysilane) ) 0.7 parts by weight, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (C Methyl ethyl ketone was added to a composition consisting of 1.0 part by weight of iba Specialty Chemicals (trade name: Irgacure 369), mixed with stirring, and degassed in vacuo. This adhesive varnish was applied on a 50 μm-thick polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin Dupont Films Co., Ltd., surface tension: 50 dyne / cm), and dried by heating at 140 ° C. for 5 minutes. An adhesive sheet provided with a substrate (polyethylene terephthalate film) and having a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 3) was produced.
The storage elastic modulus when this adhesive sheet 3 is cured at 170 ° C. for 1 hour is measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of performing 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 360 MPa at 25 ° C. and 10 MPa at 260 ° C.
(Production Example 4)
45.0 parts by weight of Epicoat 828 (trade name, manufactured by Japan Epoxy Resin Co., Ltd., bisphenol A type epoxy resin, epoxy equivalent 190), ESCN195 (trade name, Sumitomo Chemical Co., Ltd., o-cresol novolak type epoxy resin, epoxy equivalent) 195) 15.0 parts by weight, Plyofen LF2882 (trade name, manufactured by Dainippon Ink and Chemicals, Inc., bisphenol A novolak resin) 40.0 parts by weight, HTR-860P-3 (trade name, manufactured by Nagase ChemteX Corporation) , Epoxy group-containing acrylic rubber, molecular weight 1,000,000, Tg-7 ° C) 66.7 parts by weight, Curesol 2PZ-CN (trade name, manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole) 0.5 part by weight Part, NUC A-187 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-glycidoxypropyl) (Limethoxysilane) 0.7 part by weight, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (Circa Chemicals, trade name: Irgacure 369) 1.0 To the composition consisting of parts by weight, methyl ethyl ketone was added, mixed with stirring, and degassed under vacuum. This adhesive varnish was applied on a 50 μm-thick polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin Dupont Films Co., Ltd., surface tension: 50 dyne / cm), and dried by heating at 140 ° C. for 5 minutes. An adhesive sheet provided with a substrate (polyethylene terephthalate film) and having a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 3) was produced.
The storage elastic modulus when this adhesive sheet 4 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of performing 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 360 MPa at 25 ° C. and 14 MPa at 260 ° C.
(Production Example 5)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to an amine imide (PB-2) in Production Example 1, the same operation as in Production Example 1 was carried out, and a substrate (polyethylene terephthalate film) was provided. An adhesive sheet having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 5) was produced.
The storage elastic modulus when the adhesive sheet 5 is cured at 170 ° C. for 1 hour is measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the pressure was 350 MPa at 25 ° C. and 35 MPa at 260 ° C.
(Production Example 6)
In Production Example 1, the same operation as in Production Example 1 was carried out except that 0.1 part by weight of benzophenone was added, and an adhesive sheet provided with a substrate (polyethylene terephthalate film) having a thickness of 50 μm (excluding the substrate) The thickness of the adhesive sheet was 50 μm) (Adhesive sheet 6).
The storage elastic modulus when this adhesive sheet 6 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the pressure was 350 MPa at 25 ° C. and 35 MPa at 260 ° C.
(Production Example 7)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to the amine imide (PB-3) in Production Example 1, the same operation as in Production Example 1 was carried out, and a substrate (polyethylene terephthalate film) was provided. An adhesive sheet having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 7) was produced.
The storage elastic modulus when this adhesive sheet 7 is cured at 170 ° C. for 1 hour is measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the pressure was 350 MPa at 25 ° C. and 35 MPa at 260 ° C.
(Production Example 8)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to imidazolium tetraphenylborate (PB-4) in Production Example 1, the same operation as in Production Example 1 was carried out to obtain a base material (polyethylene terephthalate film). ) Having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 8).
The storage elastic modulus when this adhesive sheet 8 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of performing 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 340 MPa at 25 ° C. and 30 MPa at 260 ° C.
(Production Example 9)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to imidazolium tetraphenylborate (PB-5) in Production Example 1, the same operation as in Production Example 1 was carried out to obtain a base material (polyethylene terephthalate film). ) Having a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 9).
The storage elastic modulus when this adhesive sheet 9 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring apparatus (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rise rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the result was 360 MPa at 25 ° C. and 35 MPa at 260 ° C.
(Production Example 10)
In Production Example 1, the same operation as in Production Example 1 was performed except that the amount of the 2-nitrobenzylcarbamic acid derivative (PB-1) was 0.005 parts by weight, and the film thickness provided with the substrate (polyethylene terephthalate film) was obtained. (Adhesive sheet 10 excluding the base material) was 50 μm (adhesive sheet 10).
The storage elastic modulus when the adhesive sheet 10 is cured at 170 ° C. for 1 hour is measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 380 MPa at 25 ° C. and 30 MPa at 260 ° C.
(Production Example 11)
Except that the 2-nitrobenzyl carbamic acid derivative (PB-1) was changed to 150.0 parts by weight in Production Example 1, the same operation as in Production Example 1 was carried out, and the film thickness provided with the substrate (polyethylene terephthalate film) was obtained. (Adhesive sheet 11 excluding the base material) was 50 μm (adhesive sheet 11).
The storage elastic modulus when this adhesive sheet 11 is cured at 170 ° C. for 1 hour is measured using a dynamic viscoelasticity measuring apparatus (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rise rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the pressure was 25 MPa at 30 MPa and 260 ° C. at 1 MPa.
(Production Example 12)
The same operation as in Production Example 1 except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was omitted in Production Example 1, and an adhesive sheet having a base material (polyethylene terephthalate film) and a thickness of 50 μm was provided. (The thickness of the adhesive sheet excluding the base material was 50 μm) (Adhesive sheet 12) was produced.
The storage elastic modulus when this adhesive sheet 12 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 380 MPa at 25 ° C. and 30 MPa at 260 ° C.
(Production Example 13)
42.3 parts by mass of YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., o-cresol novolak type epoxy resin, epoxy equivalent: 210), phenolite LF2882 (trade name, manufactured by Dainippon Ink and Chemicals, bisphenol A novolak) Resin) 23.9 parts by mass, HTR-860P-3) Nagase ChemteX Corporation, trade name, acrylic rubber containing epoxy group, molecular weight 1,000,000, Tg-7 ° C) 44.1 parts by mass, Cureazole 2PZ-CN ( 0.4 parts by mass of 1-cyanoethyl-2-phenylimidazole (trade name, manufactured by Shikoku Chemical Industry Co., Ltd.), NUC A-187 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-glycidoxypropyltrimethoxysilane) 0 0.75 parts by mass, 22.05 parts by mass of 4G (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd., tetraethylene glycol dimethacrylate) and - a composition comprising 0.5 parts by hydroxycyclohexyl phenyl ketone, and stirred mixed with methyl ethyl ketone and vacuum degassed. This adhesive varnish is applied on a 50 μm-thick polyethylene terephthalate film, and dried by heating at 140 ° C. for 5 minutes to obtain an adhesive sheet having a substrate (polyethylene terephthalate film) having a thickness of 50 μm (excluding the substrate). (Adhesive sheet 13) having a thickness of 50 μm.
The storage elastic modulus when this adhesive sheet 13 was cured at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm, film thickness) As a result of 80 μm, a temperature rising rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), it was 400 MPa at 25 ° C. and 50 MPa at 260 ° C.
(Production Example 14)
50 parts by weight of the polyimide resin (PI-1) obtained in Production Example 6, 10 parts by weight of o-cresol novolak type epoxy resin (trade name: ESCN-195, manufactured by Nippon Kayaku Co., Ltd.), and phenol novolak resin (Meiwa) 5.3 g of tetraphenylfosifonium tetraphenylborate (trade name: TPPK, manufactured by Hokuko Chemical Co., Ltd., trade name: TPPK) manufactured by Kasei Co., Ltd .; 0.2 parts by weight of the obtained 2-nitrobenzylcarbamic acid derivative (PB-1) is added to and dissolved in 200 parts by weight of N-methyl-2-pyrrolidone as a solvent. This was stirred well and uniformly dispersed to obtain an adhesive varnish. This adhesive varnish was applied on a 50 μm-thick polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin DuPont Films Co., Ltd., surface tension: 50 dyne / cm), and dried by heating at 150 ° C. for 20 minutes. An adhesive sheet provided with a base material (polyethylene terephthalate film) and having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 14) was produced.
(Production Example 15)
In Production Example 14, 2-nitrobenzylcarbamic acid derivative (PB-1) was converted to 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (manufactured by Ciba Specialty Chemicals, Inc.) Name: Irgacure 369) and the same operation as in Production Example 14 was carried out, and a 50 μm-thick adhesive sheet provided with a base material (polyethylene terephthalate film) (the thickness of the adhesive sheet excluding the base material was 50 μm) (Adhesive sheet 15) was produced.
(Production Example 16)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to an amine imide (PB-2) in Production Example 14, the same operation as in Production Example 14 was carried out to provide a base material (polyethylene terephthalate film). An adhesive sheet having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 16) was produced.
(Production Example 17)
Except that 0.05 parts by weight of benzophenone was added in Production Example 16, the same operation as in Production Example 16 was carried out, and an adhesive sheet provided with a substrate (polyethylene terephthalate film) and having a thickness of 50 μm (excluding the substrate) (The thickness of the adhesive sheet was 50 μm) (Adhesive sheet 17).
(Production Example 18)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to an amine imide (PB-3) in Production Example 14, the same operation as in Production Example 14 was carried out to provide a substrate (polyethylene terephthalate film). An adhesive sheet having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 18) was produced.
(Production Example 19)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to imidazolium tetraphenylborate (PB-4) in Production Example 14, the same operation as in Production Example 14 was performed, and a base material (polyethylene terephthalate film) was obtained. ) Having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material is 50 μm) (adhesive sheet 19).
(Production Example 20)
Except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was changed to imidazolium tetraphenylborate (PB-5) in Production Example 14, the same operation as in Production Example 14 was performed, and a base material (polyethylene terephthalate film) was obtained. ) Having a thickness of 50 μm (the thickness of the adhesive sheet excluding the base material was 50 μm) (adhesive sheet 20).
(Production Example 21)
50 parts by weight of the polyimide resin (PI-2) obtained in Production Example 7, 13 parts by weight of o-cresol novolak type epoxy resin (trade name: ESCN-195, manufactured by Nippon Kayaku Co., Ltd.), and phenol novolak resin (Meiwa) 6.9 parts by weight, manufactured by Kasei Co., Ltd., trade name: H-1) 0.13 parts by weight, tetraphenylfosifonium tetraphenylborate (trade name: TPPK, manufactured by Hokuko Chemical Co., Ltd.), 2-benzyl 4.0 parts by weight of 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 369) was added to N-methyl-2-solvent. Add and dissolve in 200 parts by weight of pyrrolidone. This was stirred well and uniformly dispersed to obtain an adhesive varnish. This adhesive varnish was applied on a 50 μm-thick polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin DuPont Films Co., Ltd., surface tension: 50 dyne / cm), and dried by heating at 150 ° C. for 20 minutes. An adhesive sheet provided with a substrate (polyethylene terephthalate film) and having a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 21) was produced.
(Production Example 22)
In Production Example 15, 0.004 parts by weight of 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (trade name: Irgacure 369, manufactured by Ciba Specialty Chemicals) was used. Except for this, the same operation as in Production Example 15 was performed to produce an adhesive sheet having a substrate (polyethylene terephthalate film) and a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 22). did.
(Production Example 23)
In Production Example 15, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1-one (manufactured by Ciba Specialty Chemicals, trade name: Irgacure 369) was changed to 120.0 parts by weight. Except for this, the same operation as in Production Example 15 was performed to produce an adhesive sheet having a substrate (polyethylene terephthalate film) and a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 23). did.
(Production Example 24)
In Production Example 14, the same operation as in Production Example 14 was performed except that the 2-nitrobenzylcarbamic acid derivative (PB-1) was omitted, and an adhesive sheet having a base material (polyethylene terephthalate film) and a thickness of 50 μm was provided. (The thickness of the adhesive sheet excluding the base material was 50 μm) (Adhesive sheet 24) was produced.
(Production Example 25)
50 parts by weight of the polyimide resin (PI-3) obtained in Production Example 8, 13 parts by weight of o-cresol novolak type epoxy resin (trade name: ESCN-195, manufactured by Nippon Kayaku Co., Ltd.), and phenol novolak resin (Meiwa) 6.9 parts by weight of Kasei Co., Ltd., trade name: H-1) 0.13 parts by weight of tetraphenylfosifonium tetraphenylborate (trade name: TPPK, manufactured by Hokuko Chemical Co., Ltd.) It is added and dissolved in 200 parts by weight of a certain N-methyl-2-pyrrolidone. This was stirred well and uniformly dispersed to obtain an adhesive varnish. This adhesive varnish was applied on a 50 μm-thick polyethylene terephthalate (Teijin Tetron film: G2-50, manufactured by Teijin DuPont Films Co., Ltd., surface tension: 50 dyne / cm), and dried by heating at 150 ° C. for 20 minutes. An adhesive sheet having a substrate (polyethylene terephthalate film) and a thickness of 50 μm (the thickness of the adhesive sheet excluding the substrate was 50 μm) (adhesive sheet 25) was produced.
The adhesive sheets 1 to 25 produced in Production Examples 1 to 25 were evaluated as shown in Examples 1 to 45 and Comparative Examples 1 to 11 below.
(Examples 1 to 11)
Using the adhesive sheets 1 to 11 obtained in Production Examples 1 to 11, a semiconductor device sample in which a semiconductor chip and a wiring substrate using a 25 μm-thick polyimide film as a base material are bonded together with an adhesive sheet (a solder ball is applied to one side). Formed) and examined for heat resistance and moisture resistance. As the heat resistance evaluation method, a reflow crack resistance and a temperature cycle test were applied. The reflow crack resistance was evaluated by repeating the process of passing the sample through an IR reflow furnace set at a maximum temperature of the sample surface of 240 ° C. so as to maintain the temperature for 20 seconds and cooling the sample by leaving it at room temperature twice. The cracks in the sample were visually observed and observed with an ultrasonic microscope. The probability of no crack generation (% / 100 chips) is shown. The temperature cycle resistance is as follows: a sample is left in an atmosphere of −55 ° C. for 30 minutes and then left in an atmosphere of 125 ° C. for 30 minutes as one cycle. After 1000 cycles, the sample is peeled or cracked using an ultrasonic microscope. (% / 100 chips). The moisture resistance was evaluated at a temperature of 121 ° C., a humidity of 100%, and 2.03 × 10 ⁵ This was performed by observing peeling after treatment for 72 hours in an atmosphere of Pa (pressure cooker test: PCT treatment). It is shown as the probability that no peeling occurred (% / 100 chips).
On the other hand, the adhesive sheets 1 to 11 were attached on a silicon wafer having a thickness of 150 μm, 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 at 5 mm × 5 mm at a speed of 100 mm / sec. Then, using a UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd., 500 mJ / cm 2 was used. Exposure was performed from the support film side of the adhesive sheet at the exposure amount of, and chips diced by a pickup device were picked up, and chip flying during dicing and pickup properties were evaluated. The chip flying at the time of dicing was indicated by the probability of the chip flying at the time of dicing (% / 100 chips), and the pick-up property was indicated by the probability of being able to be picked up by picking up the chip after the dicing by the pickup die bonder (% / 100 chips). .
Further, the silicon wafer with the adhesive sheet was exposed from the support film side of the adhesive sheet at an exposure amount of 500 mJ / cm 2, and the adhesive strength at the interface between the adhesive sheet and the base material before and after the exposure was measured at 90 ° peel strength (tensile strength). Speed 50 mm / min). Table 4 summarizes the results of these evaluations.
(Comparative Examples 1-2)
The adhesive sheets 12 and 13 obtained in Production Examples 12 and 13 were evaluated under the same conditions as in Example 1. Table 4 shows the results.
(Examples 12 to 21)
The adhesive sheets 14 to 23 obtained in Production Examples 14 to 23 were evaluated under the same conditions as in Example 1. Table 5 shows the results.
(Comparative Examples 3 and 4)
The adhesive sheets 24 and 25 obtained in Production Examples 24 and 25 were evaluated under the same conditions as in Examples and 1. Table 5 shows the results.

From Tables 4 and 5, it was found that the adhesive sheet of the present invention has excellent heat resistance and moisture resistance, has no chip fly during dicing, and has good pickup properties. Furthermore, since the difference in adhesive strength before and after exposure was large, the working condition tolerance was large, and it was found that the workability was excellent.
(Example 22)
The tack strength, flow amount and melt viscosity of the adhesive sheet 1 produced in Production Example 1 before and after irradiation were measured under the following conditions. The results are shown in Table 6 together with the evaluation results in Tables 4 and 5 described above.
(10) Tack strength
The tack strength of the adhesive layer of the adhesive sheet 1 was measured at 25 ° C. by a method described in JISZ0237-1991 using a tacking tester manufactured by RHESCA. The measurement conditions were as follows: probe diameter 5.1 mmφ, peeling speed 10 mm / s, contact load 9.81 × 10 ³ Pa (100 gf / cm ² ), For a contact time of 1 s.
(2) 'Flow amount
The adhesive sheet 1 is cut into a size of 10 × 20 mm, placed on a slide glass so that the adhesive layer side of the adhesive sheet is in close contact with the adhesive sheet, and is subjected to a thermocompression bonding tester (manufactured by Tester Sangyo Co., Ltd.). Pressing at 160 ° C. and 0.8 MPa for 18 seconds, the longest distance protruding beyond the initial size from the end of the long piece of 20 mm for the four samples is 2 points for each sample with an optical microscope, for a total of 8 points Measured and measured the flow volume consisting of the average value
(3) 'Melting viscosity
After laminating eight adhesive layers of the adhesive sheet 1 to form a film having a thickness of about 400 μm, this was punched out into a circular shape having a diameter of 11.3 mm as a sample. It was pressurized with 5N (2.5 kgf) for 5 seconds, measured by a parallel plate plus and a meter method, and the melt viscosity (η) was calculated by the following equation.

(Where Z0 is the thickness of the adhesive film before applying the load, Z is the thickness of the adhesive film after applying the load, V is the volume of the adhesive film, F is the applied load, and t is the applied load. Represents time)
(Examples 23 to 25)
The tack strength, flow amount, and melt viscosity of the adhesive sheets 2 to 4 prepared in Production Examples 2 to 4 before and after irradiation were measured under the same conditions as in Example 22. Table 6 shows the results.
(Examples 26 to 29)
The tack strength, flow amount, and melt viscosity of the adhesive sheets 14 to 17 produced in Production Examples 14 to 17 before and after irradiation were measured under the same conditions as in Example 22. Table 6 shows the results.
(Comparative Examples 5 to 6)
The tack strength, flow amount, and melt viscosity of the adhesive sheets 12 and 25 produced in Production Examples 12 and 25 before and after irradiation were measured under the same conditions as in Example 22. Table 6 shows the results.

From Table 6, it was found that the adhesive sheet of the present invention did not cause chip flying at the time of dicing because of excellent adhesion to the wafer before exposure.
Further, the adhesive sheet of the present invention was found to be excellent in pick-up properties because the adhesive strength to the semiconductor chip interface after irradiation was greatly reduced.
In addition, the adhesive sheet of the present invention was found to be excellent in reliability such as heat resistance and moisture resistance, since the decrease in film fluidity before and after irradiation was small.
(Example 30)
Using an UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd., the adhesive sheet 1 produced in Production Example 1 was exposed from the base film side of the adhesive sheet at an exposure amount of 500 mJ / cm2. The tack strength after irradiation was measured in the same manner as in Example 22.
Further, the adhesive sheet 1 was exposed in the same manner as described above, and tan δ and storage elasticity before and after irradiation were measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology Co., Ltd., automatic static load) under the following conditions. It was measured. The results are shown in Table 7 together with the reliability evaluation results shown in Tables 4 and 5.
Sample size: length 20mm, width 4mm, film thickness 80μm
Heating rate: 5 ° C / min,
Measurement mode: Tension mode,
Frequency: 10Hz
(Examples 31 to 33)
The tack strength, tan δ, and storage modulus of the adhesive sheets 2 to 4 prepared in Production Examples 2 to 4 before and after irradiation were measured under the same conditions as in Example 30. The results are shown in Table 7 together with the reliability evaluation results shown in Tables 4 and 5.
(Examples 34 to 37)
The tack strength, tan δ, and storage modulus of the adhesive sheets 14 to 16 and 21 prepared in Production Examples 14 to 16 and 21 before and after irradiation were measured under the same conditions as in Example 30. The results are shown in Table 7 together with the reliability evaluation results shown in Tables 4 and 5.
(Comparative Examples 7 to 9)
The tack strength, tan δ, and storage modulus of the adhesive sheets 12, 13 and 25 produced in Production Examples 12, 13 and 25 before and after irradiation were measured under the same conditions as in Example 30. The results are shown in Table 7 together with the reliability evaluation results shown in Tables 4 and 5.

From Table 7, it was found that the adhesive sheet of the present invention was excellent in pickup properties because the adhesiveness with the base film was sufficiently reduced after irradiation with radiation. Furthermore, since the fluidity did not decrease much even after irradiation, it was found that it had excellent reliability such as heat resistance and moisture resistance.
(Example 38)
Using an UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd., the adhesive sheet 1 produced in Production Example 1 was exposed from the base film side of the adhesive sheet at an exposure amount of 500 mJ / cm2. Using the same device as in Example 30, the storage elastic modulus before and after irradiation was measured. In addition, the storage elastic modulus of the adhesive layer cured at 170 ° C. for 1 hour was measured in the same manner. On the other hand, the flow amount and the melt viscosity after irradiation were measured under the same conditions as in Example 22. Furthermore, a semiconductor device sample (a solder ball is formed on one side) is prepared by bonding a semiconductor chip (5 mm × 5 mm × 400 μm thick) and a wiring substrate using a polyimide film of 25 μm thickness as a base material with an adhesive sheet after irradiation with radiation. Then, the adhesive strength at 250 ° C. was measured using an automatic adhesive strength tester (manufactured by Hitachi Chemical Technoplant Co., Ltd.) as shown in FIG. The results are shown in Table 8 together with the results shown in Table 2.
(Examples 39 to 45)
Storage elastic modulus before and after irradiation of the adhesive sheets 2 to 4 and 14 to 17 produced in Production Examples 2 to 4 and 14 to 17; storage elastic modulus of the adhesive layer cured at 170 ° C. for 1 hour; after irradiation , The melt viscosity and the adhesive strength at 250 ° C. were measured under the same conditions as in Example 38. The results are shown in Table 8 together with the results shown in Tables 4 and 5.
(Comparative Examples 10 and 11)
Adhesive sheets 12 and 13 prepared in Production Examples 12 and 13 Storage elastic modulus before and after irradiation, storage elastic modulus of adhesive layer cured at 170 ° C. for 1 hour, flow amount after irradiation, melt viscosity and 250 ° C. Was measured under the same conditions as in Example 38. The results are shown in Table 8 together with the results shown in Tables 4 and 5.

From Table 8, it was found that the adhesive sheet of the present invention was excellent in reliability such as heat resistance and moisture resistance because the fluidity of the film before and after irradiation was small. In addition, since the storage elastic modulus difference before and after the irradiation was large, it was found that there was no chip fly during dicing and the pickup was excellent.
<Evaluation method>
(1) Storage modulus
The storage elastic modulus of the adhesive sheet was measured using a dynamic viscoelasticity measuring device (manufactured by Rheology Co., DVE-V4) (sample size: length 20 mm, width 4 mm, film thickness 80 μm, heating rate 5 ° C./min, (Tensile mode, 10 Hz, automatic static load).
(2) Measurement of flow volume
An adhesive sheet having a thickness of 50 μm (thickness of the adhesive sheet excluding the substrate layer) including an adhesive layer and a base layer (PET film (Teijin Tetron film G2-50 manufactured by Teijin DuPont Films, Inc.)) A 1 × 2 cm strip sample S having a size of 1 × 2 cm was prepared by punching a 1 × 2 cm strip. Then, in a thermocompression test apparatus (manufactured by Tester Sangyo Co., Ltd.), the strip sample S was placed on a stage heated to 160 ° C., and a pressure of 0.8 MPa was applied for 18 seconds. Then, after taking out the sample S from the thermocompression bonding test apparatus, as shown in FIG. 12, the resin protruding from the end of the long piece (2 cm side) of the sample S is indicated by 55 and 56 in the figure. As described above, the first and second longest protrusion distances (longitudinal distances a) were measured with an optical microscope. Such an operation was performed for four samples, and the average value of the protruding distances, that is, the average value of the distances of eight points in total, was obtained as the flow amount.
(3) Melt viscosity
The value measured and calculated by the parallel plate plastometer method was used as the melt viscosity of the adhesive sheet. Eight adhesive sheets are laminated to produce a film having a thickness of about 400 μm. This was punched out into a circle having a diameter of 11.3 mm as a sample. The sample was pressurized at 160 ° C. with a load of 2.5 kgf for 5 seconds, and the melt viscosity was calculated from the thickness of the sample before and after pressurization using Formula 1.

(Where Z0 is the thickness of the adhesive sheet before applying the load, Z is the thickness of the adhesive sheet after applying the load, V is the volume of the adhesive sheet, F is the applied load, and t is the applied load. Represents time.)
(4) Peel strength against gold plating (adhesive strength)
A chip (5 mm square) and a gold-plated substrate (flexible substrate with copper foil electrolytic gold plating (Ni: 5 μm, Au: 0.3 μm)) are laminated on an adhesive sheet on a 120 ° C. hot plate, and cured at 130 ° C. for 30 min + 170 ° C. for 1 h. did. The peel strength at 250 ° C. of the sample was measured at normal temperature and after moisture absorption (85/85, 48 h).
(5) Reflow crack resistance and temperature cycle resistance (test)
500 mJ / cm using a UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd. ² A semiconductor device sample in which a semiconductor element and an adhesive sheet and a wiring board using a polyimide film having a thickness of 25 μm as a base material are bonded to each other using the adhesive sheet exposed from the support film side of the adhesive sheet with an exposure amount of Ball was formed), and heat resistance and moisture resistance were examined. As a method for evaluating heat resistance, a reflow crack resistance and a temperature cycle test were applied. The evaluation of the reflow crack resistance is based on J-STD-020A, which is a JEDEC standard, and the semiconductor device sample that has been subjected to the moisture absorption treatment (85 ° C., 85% RH, 168 hours) corresponding to level 2 is evaluated on the sample surface. The sample was passed through an IR reflow furnace set at a maximum temperature of 265 ° C. and maintained at a temperature of 260 ° C. or higher for 10 to 20 seconds, and cooled by standing at room temperature twice. Cracks in the sample were visually observed. And observed with an ultrasonic microscope.も の indicates that no cracks occurred, and X indicates that cracks occurred. The temperature cycle resistance is as follows: a sample is left in an atmosphere of -55 ° C for 30 minutes and then left in an atmosphere of 125 ° C for 30 minutes as one cycle, and after 1000 cycles, destruction such as peeling or cracking is performed using an ultrasonic microscope. Indicates that no occurrence occurred, and x indicates occurrence.
(6) Moisture resistance evaluation
Temperature 121 ° C, humidity 100%, 2.03 × 10 ⁵ This was performed by observing peeling after treatment for 72 hours in an atmosphere of Pa (pressure cooker test: PCT treatment). When no peeling was observed, it was evaluated as ○, and when peeled, it was evaluated as x.
(7) Chip fly and pick-up during dicing
The adhesive sheet was stuck on a silicon wafer having a thickness of 150 μm, 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 at a speed of 100 mm / sec into 5 mm × 5 mm. Then, using a UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd., 2,000 mJ / cm. ² The semiconductor element exposed to light from the support film side of the adhesive sheet at the exposure amount was picked up and diced by a pickup device, and the semiconductor element flying during dicing and the pickup property were evaluated. The probability (% / 100 semiconductor elements) that the semiconductor element after dicing was successfully picked up by the pick-up die bonder is shown.
(8) Storage modulus, tan δ
The storage elastic modulus and tan δ of the adhesive layer were measured using a dynamic viscoelasticity measuring device (manufactured by Rheology Co., DVE-V4, automatic static load) under the following conditions.
Sample size: length 20mm, width 4mm, film thickness 80μm
Heating rate: 5 ° C / min, Measurement mode: Tensile mode, Frequency: 10 Hz
(9) 90 ° peeling force (adhesive strength)
The adhesive sheet is laminated on the semiconductor wafer at 120 ° C. with the adhesive layer interposed therebetween, and the silicon wafer with the adhesive sheet is laminated at 500 mJ / cm. ² The adhesive sheet was exposed from the substrate side at the exposure amount of, and the adhesive strength of the adhesive / adhesive layer / substrate interface before and after the exposure was measured at a 90 ° peel strength (tensile speed: 50 m / min).
(10) Tack strength
The tack strength at 25 ° C. was measured using a tacking tester manufactured by RHESCA according to the method described in JISZ0237-1991 under the following measurement conditions.
Probe diameter: 5.1 mmΦ, peeling speed: 10 mm / s, contact load: 100 gf / cm ² , Contact time: 1s
(11) Evaluation of heat resistance and moisture resistance
500 mJ / cm using a UV-330 HQP-2 type exposure machine manufactured by Oak Manufacturing Co., Ltd. ² Using the adhesive sheet exposed from the support film side of the adhesive sheet at the exposure amount of the above, a semiconductor element and a wiring board using the adhesive sheet and a polyimide film having a thickness of 25 μm as a base material at 180 ° C., 0.4 N for 5 seconds Semiconductor device samples (with solder balls formed on one side) bonded under the conditions were prepared, and heat resistance and moisture resistance were examined. As a method for evaluating heat resistance, a reflow crack resistance and a temperature cycle test were applied. The evaluation of the reflow crack resistance is based on J-STD-020A, which is a JEDEC standard, and the semiconductor device sample that has been subjected to the moisture absorption treatment (85 ° C., 85% RH, 168 hours) corresponding to level 2 is evaluated on the sample surface. The sample is passed through an IR reflow furnace set at a maximum temperature of 265 ° C. and maintained at a temperature of 260 ° C. or higher for 10 to 20 seconds, and cooled by standing at room temperature twice. Was observed visually and with an ultrasonic microscope.も の indicates that no crack or peeling occurred, and X indicates that occurred. The temperature cycle resistance is as follows: a sample is left in an atmosphere of -55 ° C for 30 minutes and then left in an atmosphere of 125 ° C for 30 minutes as one cycle, and after 1000 cycles, destruction such as peeling or cracking is performed using an ultrasonic microscope. Indicates that no occurrence occurred, and x indicates occurrence. The moisture resistance was evaluated at a temperature of 121 ° C., a humidity of 100%, and 2.0.3 × 10 ⁵ The test was performed by observing peeling after treatment for 72 hours in an atmosphere of Pa (pressure cooker test: PCT treatment). When no peeling was observed, it was evaluated as ○, and when peeled, it was evaluated as x.
(12) Tg of thermoplastic resin used
The Tg of the thermoplastic resin used was determined by a suggestive scanning calorimeter (DSC) at a heating rate of 10 ° C./min.
(13) Weight average molecular weight of thermoplastic resin used
It was measured using gel permeation chromatography and converted using a standard polystyrene calibration curve.
(14) Change rate of calorific value by DSC
In the present adhesive sheet, the rate of change (reaction rate) when the calorific value by DSC of the adhesive layer when irradiated with radiation is A and the calorific value before irradiation is B is expressed by the formula: (BA) ) / B. The DSC measurement conditions are as follows.
Heating rate: 10 ° C / min, Measurement temperature: 20 ° C to 300 ° C
(15) 90 ° peeling force
500 mJ / cm to a silicon wafer with an adhesive sheet obtained by sticking the adhesive sheet on a silicon wafer having a thickness of 150 μm. ² And the adhesive strength between the adhesive layer and the substrate interface before and after the exposure was measured by a 90 ° peeling force (tensile speed: 50 mm / min).
The present application is based on Japanese patent applications filed by the same applicant, namely, Japanese Patent Application No. 2001-256285 (filing date: August 27, 2001) and Japanese Patent Application No. 2001-256286 (filing date: August 27, 2001). Japanese Patent Application No. 2001-262662 (filing date: August 31, 2001), Japanese Patent Application No. 2001-269013 (filing date: September 5, 2001), Japanese Patent Application No. 2002-35488 (filing date: February 2002) 13th), Japanese Patent Application No. 2002-37032 (filed on February 14, 2002), Japanese Patent Application No. 2002-76577 (filed on March 19, 2002), and Japanese Patent Application No. 2002-83777 (filed on March 3, 2002). Japanese Patent Application No. 2002-83818 (filing date: March 25, 2002), Japanese Patent Application No. 2002-83844 (filing date: March 25, 2002), Japanese Patent Application No. 2002-137. 52 No. be those with the priority claim based on (filed May 13, 2002), which is incorporated these specification herein by reference.
Industrial applicability
The adhesive sheet of the present invention can be used as a dicing tape in the dicing step, and as an adhesive having excellent connection reliability in the joining step of the semiconductor element and the support member. It has heat resistance and moisture resistance necessary for mounting a semiconductor element having a large difference, and is excellent in workability.
Further, the method for manufacturing a 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 element mounting support member. It has the necessary heat resistance, moisture resistance and workability in such a case.
[Brief description of the drawings]
FIG. 1
It is sectional drawing of an example of the adhesive sheet which concerns on this invention.
FIG. 2
It is sectional drawing of another example of the adhesive sheet which concerns on this invention.
FIG. 3
It is a figure showing the state where the semiconductor wafer was stuck on the adhesive sheet concerning the present invention.
FIG. 4
It is explanatory drawing in the case where the adhesive sheet which concerns on this invention is used for the dicing process of a semiconductor wafer.
FIG. 5
FIG. 5 is a diagram illustrating a state in which the adhesive sheet is irradiated with radiation from the back surface after the step illustrated in FIG. 4.
FIG. 6
FIG. 6 is a view showing a step of picking up a semiconductor element after the step shown in FIG. 5.
FIG. 7
It is a figure which shows the semiconductor element and the adhesive layer which were picked up.
FIG. 8
It is a figure showing the state where a semiconductor element was thermocompression-bonded to a supporting member for semiconductor element mounting.
FIG. 9
Of the imidazolium tetraphenylborate obtained in Synthesis Example 4 ¹ It is an H-NMR chart.
FIG. 10
Of the imidazolium tetraphenylborate obtained in Synthesis Example 5 ¹ It is an H-NMR chart.
FIG. 11
It is a schematic diagram of an automatic adhesion tester.
FIG. 12
It is a figure showing the measuring method of the protruding distance.
Explanation of reference numerals
1. Base film
2. First adhesive layer
3. Second adhesive layer
4: Suction collet
5. Support member for mounting semiconductor element
10, 11 ... adhesive sheet
A: Semiconductor wafer
A1, A2, A3 ... Semiconductor element
B ... Radiation
21 ... Semiconductor chip
22 ... Adhesive sheet
23 Wiring board
31 ... action part
32 ... body
40 ... Stop part
41 ... Hot plate
C: Automatic adhesion tester
D: Semiconductor device sample
50 ... arrow
S: Test piece

Claims (46)

An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation,
The adhesive sheet, wherein the adhesive layer contains the following components.
(A) a thermoplastic resin,
(B) a thermopolymerizable component, and (c) a compound that generates a base upon irradiation with radiation The adhesive sheet according to claim 1, wherein the compound (c) that generates a base upon irradiation with radiation generates a base having a pKa of 7 or more in an aqueous solution upon irradiation with radiation. 3. The adhesive sheet according to claim 1, wherein the compound (c) that generates a base upon irradiation with radiation generates a base with light having a wavelength of 150 to 750 nm. 4. The adhesive sheet according to any one of claims 1 to 3, wherein the compound (c) that generates a base upon irradiation with radiation is an α-aminoketone compound. The adhesive sheet according to any one of claims 1 to 3, wherein the compound (c) that generates a base upon irradiation with radiation is an amine imide compound. The adhesive sheet according to any one of claims 1 to 3, wherein (c) the compound that generates a base upon irradiation with radiation is an imidazolium salt compound represented by the general formula (1) or (2).

(Wherein R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms, and 4 carbon atoms. Cycloalkyl group having 1 to 6 carbon atoms, cycloalkenyl group having 4 to 8 carbon atoms, phenoxyalkyl group having 1 to 6 carbon atoms, phenylalkyl group having 1 to 6 carbon atoms, cyanoalkyl group having 1 to 6 carbon atoms, 1 carbon atom A phenyl group substituted with a hydroxyalkyl group, a phenyl group, an electron-donating group and / or an electron-withdrawing group, a benzyl group, a benzyl group substituted with an electron-donating group and / or an electron-withdrawing group, a nitro group, Shows cyano group, mercapto group, thiomethyl group, fluorine, bromine, chlorine and iodine.
Ar ₁ is an aromatic group represented by the following formulas (I) to (XIV);

(Wherein, R ^{5 to} R ²⁸ are independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, and an alkylidene group having 1 to 8 carbon atoms. A cycloalkyl group having 4 to 8 carbon atoms, a cycloalkenyl group having 4 to 8 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a morpholino group, a mercapto group, Hydroxyl group, hydroxyalkyl group having 1 to 6 carbon atoms, halogen such as fluorine, chlorine, bromine, ester group having 1 to 6 carbon atoms, carbonyl group having 1 to 6 carbon atoms, aldehyde group, cyano group, trifluoromethyl group, A cyano group, a nitro group, a phenyl group, a phenyl group substituted by an electron-donating group and / or an electron-withdrawing group, and a benzyl group substituted by an electron-donating group and / or an electron-withdrawing group. , U V, W, Y, Z are independently represents carbon, nitrogen, oxygen, or sulfur atoms.)
Ar ₂ is an aromatic group represented by the following formulas (XV) to (XXIII);

(In the formula, R _{29 to} R ₃₆ are independently hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkylthio group having 1 to 8 carbon atoms, an alkylidene group having 1 to 8 carbon atoms. A cycloalkyl group having 4 to 8 carbon atoms, a cycloalkenyl group having 4 to 8 carbon atoms, an amino group, an alkylamino group having 1 to 6 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a morpholino group, a mercapto group, Hydroxyl group, hydroxyalkyl group having 1 to 6 carbon atoms, halogen such as fluorine, chlorine, bromine, ester group having 1 to 6 carbon atoms, carbonyl group having 1 to 6 carbon atoms, aldehyde group, cyano group, trifluoromethyl group, A phenyl group substituted by a cyano group, a nitro group, a phenyl group, an electron donating group and / or an electron withdrawing group, and a benzyl group substituted by an electron donating group and / or an electron withdrawing group, wherein A and B are , D E is independently a carbon, nitrogen, oxygen, any of a sulfur atom, they carbon, nitrogen, alkyl group having 1 to 6 carbon atoms, oxygen, may be combined with the sulfur.)
Further, X ^- is a dialkyl dithiocarbamate having 1 to 6 carbon atoms, a boric acid represented by the following formula (XXIV).

(In the formula, R _{37 to} R ₄₀ are independently hydrogen, fluorine, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a fluorophenyl group substituted with at least one or more fluorine atoms, or an imidazole group.) The adhesive sheet according to claim 1, wherein the adhesive layer contains (d) a singlet or triplet sensitizer. The adhesive sheet according to claim 7, wherein the (d) singlet or triplet sensitizer is at least one selected from the group consisting of a naphthalene derivative, an anthracene derivative, a carbazole derivative, a thioxanthone derivative, a benzophenone derivative, and a benzoin derivative. . The adhesive sheet according to any one of claims 1 to 8, wherein the thermoplastic resin (a) is a high molecular weight component containing a functional monomer and having a weight average molecular weight of 100,000 or more. The high molecular weight component having a weight average molecular weight of 100,000 or more containing the functional monomer is a glycidyl group-containing (meth) acrylic copolymer containing 0.5 to 6% by weight of a glycidyl group-containing repeating unit. The adhesive sheet according to the above. The adhesive layer comprises 10 to 400 parts by weight of a high molecular weight component containing the functional monomer and having a weight average molecular weight of 100,000 or more, 100 parts by weight of the (b) thermopolymerizable component, and (c) The adhesive sheet according to claim 9, which comprises 0.01 to 200 parts by weight of a radiation polymerizable compound which generates a base upon irradiation. The adhesive sheet according to any one of claims 1 to 8, wherein the (a) thermoplastic resin is a polyimide resin. The adhesive layer includes 100 parts by weight of the polyimide resin, 1 to 200 parts by weight of the (b) thermopolymerizable component, and 0.01 to 200 parts by weight of a compound that generates a base upon irradiation with radiation (c). The adhesive sheet according to claim 12, wherein the adhesive sheet contains a part. The adhesive sheet according to any one of claims 1 to 13, wherein the (b) thermopolymerizable component is an epoxy resin and an epoxy resin curing agent. The adhesive layer may have (A1) an adhesive strength of 200 mN / cm or more at an interface between the adhesive layer and the base material layer before irradiation, or (A2) the adhesiveness before irradiation. The adhesive sheet according to claim 1, wherein the adhesive layer has a tack strength at 25 ° C. of at least 0.5 N measured by a 5.1 mmφ probe and has at least one of the following characteristics.
(B1) a flow amount at 160 ° C. before irradiation is 100 to 10,000 μm;
(B2) melt viscosity at 160 ° C. before irradiation is 50 to 100000 Pa · s The adhesive layer has a (C1) adhesive strength difference between the adhesive layer / substrate layer interface before and after irradiation (adhesion strength before irradiation−adhesion strength after irradiation) of 100 mN / cm or more. Or (C2) a difference in tack strength at 25 ° C. (tack strength at 25 ° C. before irradiation—tack strength at 25 ° C. after irradiation) of 0.1 N / 2. The adhesive sheet according to claim 1, which is not less than a 5.1 mm Φ probe and has at least one of the following characteristics.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less. The adhesive layer has an uncured or semi-cured storage elastic modulus at 50 ° C of 0.1 MPa or more and 200 MPa or less, and has a storage elastic modulus at 50 ° C after irradiation with a certain amount of radiation. The pressure-sensitive adhesive layer which is twice as large as before and has been irradiated with a certain amount of radiation has at least one of the following properties (E), (F) and (G). The adhesive sheet according to claim 1, which is formed.
(E) a flow rate at 160 ° C. of 100 μm or more and 10,000 μm or less;
(F) a melt viscosity at 160 ° C. of 50 Pa · s or more and 10 ⁶ Pa · s or less, and (G) a storage elastic modulus at 180 ° C. of 100 MPa or less. An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation,
The adhesive layer has (A1) an adhesive strength of 200 mN / cm or more at an interface between the adhesive layer and the base material layer before irradiation, and has at least one of the following characteristics. An adhesive sheet provided.
(B1) a flow amount at 160 ° C. before irradiation is 100 to 10,000 μm;
(B2) melt viscosity at 160 ° C. before irradiation is 50 to 100000 Pa · s 19. The adhesive sheet according to claim 18, wherein a flow amount ratio before and after radiation irradiation (flow amount after irradiation / flow amount before irradiation) is 0.1 or more. 20. The adhesive sheet according to claim 18, wherein an adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) of the interface between the adhesive layer and the base material layer before and after radiation is 0.5 or less. Adhesive sheet. 20. The adhesive sheet according to any one of claims 17 to 19, wherein a difference in adhesive strength (adhesive strength before irradiation-adhesive strength after irradiation) between the adhesive layer and the base material layer interface before and after irradiation is 100 mN / cm or more. The adhesive sheet according to claim 1. The adhesive sheet according to any one of claims 18 to 20, wherein a melt viscosity ratio (melt viscosity after irradiation / melt viscosity before irradiation) of the adhesive sheet before and after irradiation is 100 or less. An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation,
The adhesive layer has (A2) a tack strength at 25 ° C. of 0.5 N or more measured by a 5.1 mmΦ probe before irradiation with radiation, and at least one of the following characteristics: Adhesive sheet with two properties.
(B1) a flow amount at 160 ° C. before irradiation is 100 to 10,000 μm;
(B2) melt viscosity at 160 ° C. before irradiation is 50 to 100000 Pa · s 24. In the adhesive sheet, a tack strength difference at 25 ° C. (tack strength before irradiation−tack strength after irradiation) of the adhesive layer before and after irradiation with a 5.1 mmΦ probe is 0.1 N or more. Adhesive sheet. 25. The adhesive sheet according to claim 23, wherein the adhesive sheet has a flow amount ratio before and after radiation irradiation (flow amount after irradiation / flow amount before irradiation) of 0.1 or more. 25. The adhesive sheet according to claim 23, wherein the adhesive sheet has a melt viscosity ratio before and after irradiation (melt viscosity after irradiation / melt viscosity before irradiation) of 100 or less. The adhesive sheet according to any one of claims 18 to 26, wherein the adhesive force between the adhesive layer and the base material layer is controlled by irradiating radiation. The adhesive sheet according to claim 27, wherein the radiation is light having a wavelength of 150 nm to 750 nm. The adhesive sheet according to any one of claims 18 to 28, wherein the adhesive strength after irradiation is 100 mN / cm or less. An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation,
The adhesive layer has a (C1) adhesive strength difference between the adhesive layer / substrate layer interface before and after irradiation (adhesion strength before irradiation−adhesion strength after irradiation) of 100 mN / cm or more. And an adhesive sheet having at least one of the following properties.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less. 31. The adhesive sheet according to claim 30, wherein an adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) at the interface between the adhesive layer and the base material layer before and after irradiation is 0.5 or less. Adhesive sheet. 31. The adhesive sheet, wherein the adhesive strength at the interface between the adhesive layer and the base material layer before radiation is 200 mN / cm or more, and the adhesive strength after radiation is 100 mN / cm or less. Adhesive sheet. An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation,
The adhesive layer has a (C2) difference in tack strength at 25 ° C. before and after irradiation (tack strength at 25 ° C. before irradiation—tack strength at 25 ° C. after irradiation). An adhesive sheet having a 0.1N / 5.1 mmφ probe or more and having at least one of the following characteristics.
(D1) Tan δ at 120 ° C. before irradiation is 0.1 or more, tan δ at 180 ° C. after irradiation is 0.1 or more,
(D2) Storage elastic modulus at 120 ° C. before irradiation is 10 MPa or less, and storage elastic modulus at 180 ° C. after irradiation is 100 MPa or less. 34. The adhesive sheet according to claim 33, wherein an adhesive strength ratio (adhesive strength after irradiation / adhesive strength before irradiation) at the interface of the adhesive layer / base layer before and after irradiation is 0.5 or less. Adhesive sheet. 35. The adhesive sheet, wherein the adhesive strength before radiation at the interface between the adhesive layer and the base material layer is 200 mN / cm or more, and the adhesive strength after radiation is 100 mN / cm or less. Adhesive sheet. An adhesive sheet comprising an adhesive layer and a substrate layer, wherein the adhesive force between the adhesive layer and the substrate layer is controlled by irradiation of radiation,
The adhesive layer has an uncured or semi-cured storage elastic modulus at 50 ° C of 0.1 MPa or more and 200 MPa or less, and has a storage elastic modulus at 50 ° C after irradiation with a certain amount of radiation. The pressure-sensitive adhesive layer which is twice as large as before and has been irradiated with a certain amount of radiation has at least one of the following properties (E), (F) and (G). Adhesive sheet made.
(E) a flow rate at 160 ° C. of 100 μm or more and 10,000 μm or less;
(F) a melt viscosity at 160 ° C. of 50 Pa · s or more and 10 ⁶ Pa · s or less, and (G) a storage elastic modulus at 180 ° C. of 100 MPa or less. The flow amount A at 160 ° C. of the adhesive layer of the adhesive sheet in an uncured or semi-cured state and the flow amount B of the adhesive layer after irradiating the adhesive sheet with a certain amount of radiation are B / A. The adhesive sheet according to claim 36, wherein a relationship of ≧ 1/10 is satisfied. The adhesive sheet according to claim 36 or 37, wherein a storage elastic modulus at 50 ° C of the adhesive layer after irradiating a fixed amount of radiation to the uncured or semi-cured adhesive sheet is 15 MPa or more. The adhesive sheet according to any one of claims 36 to 38, wherein the adhesive layer satisfies the following conditions.
1) The storage elastic modulus at 100 ° C. in an uncured or semi-cured state is 0.001 MPa or more and 2 MPa or less; 2) The storage elastic modulus at 50 ° C. is 7.5 MPa or more and 50 MPa or less; 3) After irradiation The storage elastic modulus at 50 ° C. is from 15 MPa to 100 MPa, and 4) the storage elastic modulus at 50 ° C. after curing is from 100 MPa to 5000 MPa. The adhesive strength at 5O <0> C of a laminated cured product of a 5 mm square semiconductor element and a support member using the adhesive layer of the adhesive sheet after irradiation with radiation is 3.0 N / chip or more. The adhesive sheet according to claim 1. The storage elastic modulus of the adhesive layer of the adhesive sheet after heat curing, when measured using a dynamic viscoelasticity measuring device, is 10 MPa or more and 2000 MPa or less at 25 ° C, and 3 MPa or more and 50 MPa or less at 260 ° C. The adhesive sheet according to any one of claims 36 to 40. The adhesive sheet according to any one of claims 36 to 41, wherein an adhesive force between the adhesive layer and the base material layer is controlled by irradiating a radiation. The adhesive sheet according to claim 42, wherein the radiation is light having a wavelength of 150 nm to 750 nm. The adhesive sheet according to any one of claims 36 to 43, wherein the adhesive strength after irradiation is 100 mN / cm or less. A step of attaching an adhesive sheet comprising the adhesive layer and the base material layer according to any one of claims 1 to 44 to a semiconductor wafer with the adhesive layer interposed therebetween; Dicing to form a semiconductor element with a pressure-sensitive adhesive layer; irradiating the adhesive sheet with radiation after dicing to cure the pressure-sensitive adhesive layer, and thereafter peeling the base film layer; Bonding the semiconductor element with the adhesive layer and the supporting member for mounting the semiconductor element, or bonding the semiconductor elements to each other via the adhesive sheet. A semiconductor device having a structure in which a semiconductor element and a supporting member for mounting a semiconductor element or a semiconductor element is bonded to each other using the adhesive sheet according to any one of claims 1 to 44.

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