JP3967805B2 - Photoresist film - Google Patents

Description

だだしｌ、ｍ、ｎは０又は正数を示す。
【００１９】
エチレンオキシド変性トリメチロールプロパントリアクリレート以外のエチレン性不飽和化合物としては多官能モノマーや単官能モノマーが単独、または２種以上用いられる。
多官能モノマーとして具体的には、エチレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート、テトラエチレングリコールジ（メタ）アクリレート、プロピレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ブチレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、１，６−ヘキサングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、グリセリンジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、２，２−ビス（４−（メタ）アクリロキシジエトキシフェニル）プロパン、２，２−ビス−（４−（メタ）アクリロキシポリエトキシフェニル）プロパン、２−ヒドロキシ−３−（メタ）アクリロイルオキシプロピル（メタ）アクリレート、エチレングリコールジグリシジルエーテルジ（メタ）アクリレート、ジエチレングリコールジグリシジルエーテルジ（メタ）アクリレート、フタル酸ジグリシジルエステルジ（メタ）アクリレート、グリセリンポリグリシジルエーテルポリ（メタ）アクリレートが挙げられるが、好ましくはプロピレングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレートが用いられる。
【００２０】
単官能モノマーとして具体的には、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、２−ヒドロキシブチル（メタ）アクリレート、２−フェノキシ−２−ヒドロキシプロピル（メタ）アクリレート、２−（メタ）アクリロイルオキシ−２−ヒドロキシプロピルフタレート、３−クロロ−２−ヒドロキシプロピル（メタ）アクリレート、グリセリンモノ（メタ）アクリレート、２−（メタ）アクリロイルオキシエチルアシッドホスフェート、フタル酸誘導体のハーフ（メタ）アクリレート、Ｎ−メチロール（メタ）アクリルアミドなどが挙げられ、好ましくは、２−フェノキシ−２−ヒドロキシプロピル（メタ）アクリレート、フタル酸誘導体のハーフ（メタ）アクリレートが用いられる。
【００２１】
ベースポリマー（ａ）１００重量部に対するエチレン性不飽和化合物（ｂ）の割合は、２５〜１００重量部、特に３５〜７５重量部の範囲から選ぶことが望ましい。エチレン性不飽和化合物（ｂ）の割合が１００重量部を越えると、乾燥後長期保存に耐える十分な粘度が得られず、スリットしたロール端面よりレジストが流れ出るエッジフュージョンを起こすので好ましくなく、エチレン性不飽和化合物（ｂ）の割合が２５重量部未満では乾燥後の粘度が高くなり過ぎ、可撓性不足により、カッティングの際にチップが出たり、架橋成分不足により、現像で良好なパターン形状が得られない。
【００２２】
自己開裂型開始剤（ｃ）としては下記一般式（２）で表されるもので、具体的にはベンゾイン、ベンゾインメチルエーテル、ベンゾイルイソプロピルエーテル、ベンゾインイソブチルエーテル、ベンゾインブチルエーテル、２，２−ジヒドロキシ−２−フェニルアセトフェノン、２，２−ジメトキシ−２−フェニルアセトフェノン、２，２−ジエトキシ−２−フェニルアセトフェノンなどを挙げることができる。
【化２】

［式中Ｒ¹はフェニル基、又は置換フェニル基、Ｒ²は水素、水酸基、アルコキシ基、ハロゲン、Ｒ³は水酸基、アルコキシ基を表す。］
【００２３】
かかる自己開裂型開始剤（ｃ）の配合量は特に限定されないが、ベースポリマー（ａ）１００重量部に対して、自己解裂開始剤（ｃ）は１．０〜１５重量部が好ましく、更には２〜１２重量部含まれていることが好ましく、自己開裂開始剤（ｃ）が１．０重量部よりも少ないと十分に硬化させるために多大な露光量を要し、逆に１５重量部よりも多いと、可塑剤的効果が大きくエッジフュージョンの原因となり好ましくない。
【００２４】
更に本発明では、自己開裂型開始剤（ｃ）と光重合開始剤とを併用することができ、かかる光重合開始剤としては、ベンジルジフェニルジスルフィド、ジベンジル、ジアセチル、アントラキノン、ナフトキノン、３，３′−ジメチル−４−メトキシベンゾフェノン、ベンゾフェノン、ｐ，ｐ′−ビス（ジメチルアミノ）ベンゾフェノン、ｐ，ｐ′−ビス（ジエチルアミノ）ベンゾフェノン、ピバロインエチルエーテル、１，１−ジクロロアセトフェノン、ｐ−ｔ−ブチルジクロロアセトフェノン、ヘキサアリールイミダゾール二量体、２−クロロチオキサントン、２−メチルチオキサントン、２，４−ジエチルチオキサントン、２，２−ジクロロ−４−フェノキシアセトフェノン、フェニルグリオキシレート、α−ヒドロキシイソブチルフェノン、ジベゾスパロン、１−（４−イソプロピルフェニル）−２−ヒドロキシ−２−メチル−１−プロパノン、２−メチル−［４−（メチルチオ）フェニル］−２−モルフォリノ−１−プロパノン、トリブロモフェニルスルホン、トリブロモメチルフェニルスルホン、アクリジン、９−フェニルアクリジン、２，４−トリクロロメチル−（４′−メトキシフェニル）−６−トリアジン、２，４−トリクロロメチル−（４′−メトキシナフチル）−６−トリアジン等が例示される。
【００２５】
更に、本発明では、感度向上の目的でＮ−フェニルグリシン（ｄ）を配合することも有用で、配合割合は（ａ）１００重量部に対して０．１〜１．０重量部、特に０．２〜０．５重量部が好ましく、０．１重量部未満では感度向上の効果が望めず、１．０重量部を越えると未露光状態でベース染料の変色を起こし好ましくない。
【００２６】
又、本発明では、内部硬化を向上させる目的で、２，４，５−トリフェニルイミダゾール二量体（ｅ）を配合することも有用で、配合割合は（ａ）１００重量部に対して０．５〜１５重量部、特に１．０〜５．０重量部が好ましく、０．５重量部未満では十分な内部硬化が得られない為、現像後のパターン形状が悪化し好ましくなく、１５重量部を越えると未露光状態で保存中に２，４，５−トリフェニルイミダゾール二量体（ｅ）が結晶化して析出することがあり好ましくない。
【００２７】
本発明の感光性樹脂組成物（II）には、そのほか、染料（着色、発色）、密着性付与剤、可塑剤、酸化防止剤、熱重合禁止剤、溶剤、表面張力改質材、安定剤、連鎖移動剤、消泡剤、難燃剤などの添加剤を適宜添加することができる。
【００２８】
かくして得られた感光性樹脂組成物（II）はレリーフパターン製造、プリント配線板（ＰＷＰ）や透明電極等の加工の際のエッチングレジスト又はメッキレジスト等に幅広く利用することができるが、特に厚膜のレリーフパターンの製造に最適である。
【００２９】
本発明で用いられる保護フィルム（III）は、フォトレジストフィルムをロール状にして用いる場合に、粘着性を有する感光性樹脂組成物層が支持体フィルムに転着したり、感光性樹脂組成物層に壁などが付着するのを防止する目的で感光性樹脂組成物層に積層して用いられる。かかる保護フィルムとしては、例えばポリエステルフィルム、ポリエチレンフィルム、ポリプロピレンフィルム、ポリビニルアルコールフィルム、テフロンフィルムなどが挙げられるが、本発明はかかる例示のみに限定されるものではない。なお、該保護フィルムの厚さについては特に限定はなく、通常１０〜５０μｍ、なかんずく１０〜３０μｍであればよい
。
【００３０】
かくして本発明では上記支持体フィルム（I）、感光性樹脂組成物層（II）、保護フィルム（III）を順次積層したフォトレジストフィルムとなる。
次に、本発明のフォトレジストフィルムの製造及びそれを用いる厚膜のレリーフパターンの製造について説明する。
【００３１】
（成層方法）
上記の感光性樹脂組成物（II）をポリエステルフィルム、ポリプロピレンフィルム、ポリスチレンフィルム、ビニロンフィルム等の支持フィルム（I）面に塗工した後、その塗工面の上からポリエチレンフィルム等の保護フィルム（III）を被覆してフォトレジストフィルムとする。
【００３２】
（露光）
フォトレジストフィルムによって画像を形成させるには支持体フィルム（I）と感光性樹脂組成物層（II）との接着力及び保護フィルム（III）と感光性樹脂組成物層（II）との接着力を比較し、接着力の低い方のフィルムを剥離してから感光性樹脂組成物層（II）の側を銅張基板の銅面などの金属面に貼り付けた後、他方のフィルム上にパターンマスクを密着させて露光する。感光性樹脂組成物が粘着性を有しないときは、前記他方のフィルムを剥離してからパターンマスクを感光性樹脂組成物層（II）に直接接触させて露光することもできる。
【００３３】
尚、本発明の厚膜ファインパターンの形状及び寸法としては、レリーフパターンの巾が１０〜２００μｍで隣接するパターンとの間隔が１０μｍ以上で、かつ巾と高さの比は１／１．５以下、好ましくは１／２．０以下である。又、パターンの断面形状がほぼ矩形を有し、側面と基板とのなす角度が９０°±１０°（８０°〜１００°）、更に隣接パターンとの間隔は１０μｍ以上である。
上記の如く本発明に適した厚膜レジストを形成されるためには、一度の操作で所望の厚膜を得ることが困難であることが多い。そこで上記のドライフィルムの積層においては、ベースフィルム上に形成したレジストを基材上に転写する操作を繰り返す多段ラミネート操作を行って、所望の厚膜とする方法が推奨される。更には１００μｍ以上の厚さの厚膜レジストを容易に形成することができる。
【００３４】
露光に際しては通常紫外線照射により行い、その際の光源としては、高圧水銀灯、超高圧水銀灯、カーボンアーク灯、キセノン灯、メタルハライドランプ、ケミカルランプなどが用いられる。紫外線照射後は、必要に応じ加熱を行って、硬化の完全を図ることもできる。
【００３５】
（現像）
露光後は、レジスト上のフィルムを剥離除去してから現像を行う。感光性樹脂組成物（II）層は稀アルカリ現像型であるので、露光後の現像は、炭酸ソーダ、炭酸カリウムなどのアルカリ０．３〜２重量％程度の稀薄水溶液を用いて行う。該アルカリ水溶液中には、表面活性剤、消泡剤、現像を促進させるための少量の有機溶剤等を混入させてもよい。
【００３６】
（エッチング、メッキ）
その後、通常塩化第二銅−塩酸水溶液や塩化第二鉄−塩酸水溶液等の酸性エッチング液を用いて常法に従ってエッチングを行う。希にアンモニア系のアルカリエッチング液も用いられる。メッキ法は、脱脂剤、ソフトエッチング剤などのメッキ前処理剤を用いて前処理を行った後、メッキ液を用いてメッキを行う。メッキ液としては、銅メッキ液、ニッケルメッキ液、鉄メッキ液、銀メッキ液、金メッキ液、錫メッキ液、コバルトメッキ液、亜鉛メッキ液、ニッケルコバルトメッキ液、はんだメッキ液等が挙げられる。
【００３７】
（硬化レジストの剥離除去）
エッチング工程又はメッキ工程後、残っている硬化レジストの剥離を行う。硬化レジストの剥離除去は、水酸化ナトリウム、水酸化カリウムなどの０．５〜５重量％程度の濃度のアルカリ水溶液からなるアルカリ剥離液を用いて行う。
【００３８】
本発明のフォトレジストフィルムは、特定のヘイズ値を有する支持体フィルム（I）／酸価が９５〜２５０ｍｇＫＯＨ／ｇで、重量平均分子量が５０００〜２０００００のベースポリマー（ａ）、エチレンオキシド変性トリメチロールプロパントリアクリレートを５０重量％以上含むエチレン性不飽和化合物（ｂ）、自己解裂型開始剤（ｃ）を含有してなる感光性樹脂組成物層（II）／保護フィルム（III）からなるため、感度、解像度、基板とレジストの密着性、導体への染み込みや導体のかけがないといった耐エッチング性やメッキ時にメッキラインのギザツキのないメッキ性に優れ、レジストパターンを短時間かつ高い歩留まりで行うことができ、更に厚膜ファインパターンを形成することができるのである。
【００３９】
【実施例】
以下、実施例を挙げて本発明を更に詳述する。
尚、ことわりのない限り「％」及び「部」は重量基準である。
実施例１
［感光性樹脂組成物の調製］
下記のベースポリマー（ａ）１００部に、下記のエチレン性不飽和化合物（ｂ）６７部、２，２′−ジメトキシ−２−フェニルアセトフェノン（ｃ）１０部、Ｎ−フェニルグリシン（ｄ）０．４部、２，４，５−トリフェニルイミダゾール二量体（ｅ）３．５部を配合してよく混合し、感光性樹脂組成物を調製した。
【００４０】
ベースポリマー（ａ）
メチルメタクリレート／ｎ−ブチルメタクリレート／メタクリル酸の共重合割合が重量基準で５０／２５／２５である共重合体（酸価１６３ｍｇＫＯＨ／ｇ、ガラス転移点９４℃、重量平均分子量７万）。
エチレン性不飽和化合物（ｂ）
エチレンオキシド変性トリメチロールプロパントリアクリレート６７％、ポリプロピレングリコールジアクリレート３３％からなるモノマーの混合物。
【００４１】
上記感光性樹脂組成物のドープをギャップ１０ミルのアプリケーターを用いて、ヘイズ値０．１％のポリエチレンテレフタレートフィルム（ＰＥＴフィルム）からなる支持体フィルム（I）（厚み２０μｍ）上に塗工し、室温で１分３０秒放置した後、６０℃、９０℃、１１０℃のオーブンでそれぞれ３分間乾燥して、レジスト厚５０μｍのドライフィルムとし、更にポリエチレンフィルムからなる保護フィルム（厚さ２３μｍ）をラミネートしてフォトレジストフィルムとした。
次にメチルエチルケトンで表面洗浄を行った厚さ２ｍｍのステンレススチール基板を６０℃に加温し、その表面に上記で得たフォトレジストフィルムを保護フィルムを剥がしながら、ラミネートした。その後、ＰＥＴフィルムをはがして、再度ラミネートを行い、更に同様のラミネート操作を計４回繰り返すことにより、ステンレススチール基板上に厚さ２００μｍのレジストを形成させた。
【００４２】
次いで得られた基材に、２ｋｗ水銀ショートアーク灯（平行光源）で、ストーファー２１段ステップタブレット（光透過量が段階的に少なくなるように作られたネガフィルム）の数値が９となる露光量で露光を行った。露光後１５分経過してからＰＥＴフィルムを剥離し、２０℃で０．５％炭酸ナトリウム水溶液をブレークポイント（未露光部分が完全溶解する時間）の１．５倍の現像時間でスプレーすることにより未露光部分を溶解除去して硬化樹脂画像を得た。
【００４３】
そして、この基材をニッケルメッキ液によりメッキを行った後、６０℃の３％水酸化ナトリウム水溶液で１．５ｋｇ／ｃｍ²でスプレーし、剥離を行い画像を形成した。
本発明において以下の項目を下記の如く評価した。
【００４４】
（イ）エッジフュージョン
ＰＥＴフィルムを積層したまま、作製したレジストを３００ｍｍ幅、１２０ｍ長にスリット、ロール化し、該ロールを３０℃、６０ＲＨ％の恒温、恒湿機中に横おきに遮光下で放置し、端面のレジストの浸みだしを、目視で以下の様に評価した。
○・・・３日間放置しても浸みだしがない。
×・・・３日間放置中に浸みだしを確認。
【００４５】
（ロ）感度
上記ステンレススチール基板上に設けた２００μｍ厚のレジストをカバーフィルムを除去後、炭酸ナトリウム０．５重量％、２０℃の現像液をスプレー圧０．５ｋｇ／ｃｍ²で噴霧し、基板表面が見えるまでの時間を最小現像時間とし、
最小現像時間の１．５倍の時間で、ストファーの２１段のステップダブレットを用いて現像した時、ステップ９を与える露光量（ｍｊ／ｃｍ²）を求めた。
【００４６】
（ハ）解像度
上記露光量におけるライン巾２００μｍのパターンの解像可能なスペースの巾を測定した。
【００４７】
（ニ）剥離性
ライン／スペース＝２００μｍ／２００μｍのパターンを形成後、そのスペース部に高さ１８０〜２００μｍのニッケルメッキを行った後、６０℃の３％水酸化ナトリウム水溶液を１．５ｋｇ／ｃｍ²でスプレーして、剥離を行い、以下の様に評価した。
○・・・３０分以内で剥がれ、剥離片の一部がＮｉメッキ部に残らない。
△・・・３０分以内で剥がれるが、剥離片の一部がＮｉメッキ側面に付着する。
×・・・３０分では剥がれない。
【００４８】
（ホ）密着性
ライン巾１０〜２００μｍにおいて５μｍ毎にラインを設けたパターンマスク（ラインは１本のみ−スペース巾∞）を用いて上記の解像性評価と同様に現像して密着性良好な最小ライン巾（μｍ）を調べた。
【００４９】
（ヘ）メッキ性
ライン／スペース＝４００μｍ／３００μｍの現像後、レジストパターンをメッキし、レジストを剥離した後、基材を拡大顕微鏡で観察して、メッキラインのギザツキ具合によりを目視評価した。評価基準は下記の通りである。
○・・・ギザツキなし
△・・・端部に５μｍ未満のギザツキあり
×・・・端部に５μｍ以上のギザツキあり
【００５０】
実施例２
実施例１において、Ｎ−フェニルグリシン（ｄ）を除いた以外は、実施例１に準じて感光性樹脂組成物を調製し、更にヘイズ値１．４％のＰＥＴフィルム（I）（厚み２０μｍ）を用いた以外は同様に行い、上記と同様の評価を行った。
【００５１】
実施例３
実施例１において、２，４，５−トリフェニルイミダゾール二量体（ｅ）を除いた以外は、実施例１に準じて感光性樹脂組成物を調製し、更にヘイズ値１．４％のＰＥＴフィルム（I）（厚み２０μｍ）を用いた以外は同様に行い、上記と同様の評価を行った。
【００５２】
実施例４
実施例１において、Ｎ−フェニルグリシン（ｄ）、２，４，５−トリフェニルイミダゾール二量体（ｅ）を除いた以外は、実施例１に準じて感光性樹脂組成物を調製し、更にヘイズ値１．４％のＰＥＴフィルム（I）（厚み２０μｍ）を用いた以外は同様に行い、上記と同様の評価を行った。
【００５３】
実施例５
実施例１において、エチレン性不飽和化合物（ｂ）としてエチレンオキシド変性トリメチロールプロパントリアクリレートの含量を８０％、ポリピロピレングリコールジアクリレート２０％からなるモノマーの混合物を用いた以外は、実施例１に準じて感光性樹脂組成物を調製し、更にヘイズ値１．４％のＰＥＴフィルム（I）（厚み２０μｍ）を用いた以外は同様に行い、上記と同様の評価を行った。
【００５４】
実施例６
下記ベースポリマー（ａ）を１２５部用いた以外は、実施例１に準じて感光性樹脂組成物を調製し、更にヘイズ値１．０％のＰＥＴフィルム（I）（厚み１６μｍ）を用いた以外は同様に行い、上記と同様の評価を行った。
ベースポリマー（ａ）
メチルメタクリレート／ｎ−ブチルアクリレート／２−エチルヘキシルアクリレート／メタクリル酸の共重合割合が重量基準で４８／１０／２０／２２である共重合体（酸価１４３ｍｇＫＯＨ／ｇ、ガラス転移点４０．１℃、重量平均分子量７．５万）。
【００５５】
比較例１
実施例１において、エチレン性不飽和化合物（ｂ）としてエチレンオキシド変性トリメチロールプロパントリアクリレートを４０％、ポリピロピレングリコールジアクリレート６０％からなるモノマーの混合物を用いた以外は、実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
【００５６】
比較例２
実施例１において、エチレンオキシド変性トリメチロールプロパントリアクリレートの替わりにトリメチロールプロパントリアクリレートを用いた以外は、実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
【００５７】
比較例３
実施例１において、エチレン性不飽和化合物（ｂ）として、２、２′−ビス−（４−メタクリロキシポリエトキシフェニル）プロパン（ＢＰＥ−５００）のみを用いた以外は、実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
【００５８】
比較例４
実施例１において、２，２−ジメトキシ−２−フェニルアセトフェノン（ｃ）１０部の替わりにｐ，ｐ′−ビス（ジエチルアミノ）ベンゾフェノン１部を用いた以外は、実施例１に準じて感光性樹脂組成物を調製し，上記と同様の評価を行った。
【００５９】
比較例５
実施例１において、酸価が９１ｍｇＫＯＨ／ｇのポリマーを用いて実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
【００６０】
比較例６
実施例１において、酸価が２５１ｍｇＫＯＨ／ｇのポリマーを用いて実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
【００６１】
比較例７
実施例１において、重量平均分子量が３０００の下記ベースポリマー（ａ）を用いて実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
ベースポリマー（ａ）
メチルメタクリレート／スチレン／メタクリル酸の共重合割合が重量基準で４５／３０／２５である共重合体（酸価１６３ｍｇＫＯＨ／ｇ、ガラス転移点１１８℃）。
【００６２】
比較例８
実施例１において重量平均分子量が２５万の下記ベースポリマー（ａ）を用いて実施例１に準じて感光性樹脂組成物を調製し、上記と同様の評価を行った。
ベースポリマー（ａ）
メチルメタクリレート／ｎ−ブチルアクリレート／メタクリル酸の共重合割合が重量基準で６５／１０／２５である共重合体（酸価１６３ｍｇＫＯＨ／ｇ、ガラス転移点９４℃）。
【００６３】
比較例９
実施例１において、支持体フィルム（I）として、ヘイズ値４．０％のＰＥＴフィルムを用いた以外は同様に行い、上記と同様の評価した。
【００６４】
実施例及び比較例の評価結果は、表１に示す。
【表１】

【００６５】
【発明の効果】
本発明で得られたフォトレジストフィルムは、感度、解像力、レジスト剥離性に優れ、更に金属基板への密着性が良く、導体への染み込みや導体のかけがないといった耐エッチング性やメッキ時のメッキラインのギザツキがないといったメッキ性に優れるため、印刷配線板の製造、リードフレームの製造、厚膜レリーフパターンの製造、金属の精密加工等に用いられるエッチングレジスト又はメッキレジストとして有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoresist film used for the production of a printed wiring board, and more specifically, it has excellent sensitivity, resolution, resist peelability and adhesion, and there is no application or penetration of a conductor in etching or plating due to insufficient adhesion of the resist. The present invention relates to a photoresist film excellent in etching resistance or plating property.
[0002]
[Prior art]
For the production of printed wiring boards and the like, a photoresist method using a photosensitive resin composition is used. In this photoresist method, for example, a photosensitive resin composition is first placed on a support such as a transparent film. After coating to form a photosensitive resin composition layer, this photosensitive resin composition layer is laminated on the surface of a substrate on which a desired pattern is to be formed, and then an original image is formed on the photosensitive resin composition layer with a pattern mask. After the exposure, the unexposed portion is removed by a development process using a solvent or an alkaline aqueous solution to form a resist image. After the resist image thus formed is used as a protective mask, a known etching process or pattern plating process is performed. A method of producing a printed circuit board by peeling off the resist is usually performed. In such a manufacturing process, high sensitivity is required to improve productivity and shorten time.
[0003]
Further, in recent years, as electronic devices have become smaller and lighter, printed wiring boards have become finer and higher in density, and a dry film resist having high resolution (sometimes abbreviated as DFR) is required. The width of the relief pattern is 5 to 200 μm, the distance between adjacent patterns is 10 μm or more, and the ratio of width to height is 1 / 1.5 or less. However, a good DFR has become necessary.
[0004]
Conventional techniques for obtaining a relief pattern include a method for producing a relief pattern using a photopolymerization initiator having a specific molar extinction coefficient (Japanese Patent Publication No. 5-81897), a polymer having a defined molecular weight, and an unsaturated group-containing compound. In the photopolymerization composition using dialkylaminoacetophenone and 2,4,5-triphenylimidazole dimer as an initiator, the ratio of the compound having one unsaturated group in the unsaturated group-containing compound or two A composition that defines the ratio and molecular weight of the compound (JP-A-3-6202), a binder polymer having an α, β-unsaturated ethylenic monomer, a photopolymerized polymer, a compound having a specific structural formula and 2 , 4,5-triarylimidazole dimer photosensitive resin composition using an initiator (JP-A-2-62545), 2 as an initiator , 4,5-triphenylimidazolyl dimer has been proposed (Japanese Patent Publication No. 45-37377).
[0005]
[Problems to be solved by the invention]
However, in the technique disclosed in Japanese Patent Publication No. 5-81897, as the film thickness increases, the sensitivity decreases and the pattern shape becomes thicker and the resolving power becomes insufficient, and Japanese Patent Application Laid-Open Nos. Hei 3-6202 and Hei 2-62545. In the technique disclosed in Japanese Patent Laid-Open Publication No. 2007-184, there is a problem that as the thick film becomes thicker, the sensitivity decreases, the inverted trapezoidal pattern becomes prominent, and the resist stripping, which is the final process, takes much time. In the technique disclosed in Japanese Examined Patent Publication No. 45-37377, although the sensitivity is high, the pattern shape is thick and the resolution is insufficient, and there is still room for improvement in adhesion.
[0006]
On the other hand, in order to improve sensitivity, resolution, and adhesion, it has been proposed to use a support film having a haze value of 0.1 to 1.5% as a photoresist film (Japanese Patent Laid-Open No. 6-230579). In this technique, when an ordinary alkali development type dry film resist is used, the adhesion between the metal substrate and the resist is refined with the recent advancement of the technique. However, considering refinement, it is still not satisfactory, and there is a problem that the yield is reduced, such as the conductor being applied or soaked in etching, so-called etching resistance is poor, and plating lines are jagged during plating. It remains.
[0007]
Therefore, in the present invention, under such a background, the sensitivity, the resolution, the resist peelability, and the adhesiveness are excellent. Also, the resist is not sufficiently adhered to the conductor in etching or plating. An object of the present invention is to provide a photoresist film having excellent plating properties without roughness.
[0008]
[Means for Solving the Problems]
However, as a result of intensive studies to solve such problems, the present inventors have found that in a photoresist film comprising a support film (I) / photosensitive resin composition layer (II) / protective film (III), The haze value of the film (I) is 0.01 to 1.5%, the photosensitive resin composition layer (II) has an acid value of 95 to 250 mgKOH / g, and a weight average molecular weight of 5000 to 200000. It comprises a base polymer (a), an ethylenically unsaturated compound (b), a self-cleaving initiator (c), and (b) contains 50% by weight to 80% by weight of ethylene oxide-modified trimethylolpropane triacrylate. The present inventors have found that the photoresist film to be included meets the above-mentioned purpose and have completed the present invention.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described.
The support film (I) used in the present invention is of course transparent and has a haze value of 0.01 to 1.5%, preferably 0.01 to 1.0%, more preferably 0.01 to It is necessary to be in the range of 0.5%. Here, the haze value is a value representing turbidity, and the haze value (%) is calculated from the total transmittance T of light irradiated by the lamp and transmitted through the sample and the transmittance D of light diffused and scattered in the sample. ) Is determined as H (%) = (D / T) × 100. These are defined by JIS K 7105, and can be easily measured by a commercially available turbidimeter, for example, NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd.
[0010]
A support film having a haze value of less than 0.01% is difficult to obtain, and a support film having a haze value of more than 1.5% is not capable of improving effects such as sensitivity, resolution, and adhesion. Examples of the support film (I) having a haze value of 0.01 to 1.5% include, for example, Teijin's highly transparent film GS series, Diafoil Hoechst's R series, DuPont Mylar D series, and Toray Industries, Inc. Examples thereof include polyethylene terephthalate films such as T series and vinylon films manufactured by Nippon Synthetic Chemical Industry.
The film thickness of the support film (I) is 10 to 30 μm, preferably 12 to 25 μm, and more preferably 16 to 23 μm. If it exceeds 30 μm, the resolution is lowered and the cost is increased. If it is less than 10 μm, the film is too flexible and inconvenient to handle.
[0011]
The photosensitive resin composition layer (II) of the present invention has a base polymer (a) having an acid value of 95 to 250 mgKOH / g and a weight average molecular weight of 5,000 to 200,000, an ethylenically unsaturated compound (b), a self-cleaving type. It comprises a photosensitive resin composition comprising an initiator (c) and containing 50% by weight or more of ethylene oxide-modified trimethylolpropane triacrylate in (b).
As base polymer (a) used for this invention, it is required that an acid value is 95-250 mgKOH / g, Preferably it is 110-163 mgKOH / g. If the acid value is less than 95 mg KOH / g, good developability cannot be obtained, resulting in poor resolution and poor pattern skirt shape, which is unsuitable, and if it exceeds 250 mg KOH / g, the fine line adhesion failure due to a decrease in developer resistance, Due to swelling during development, the resolution is poor and is unsuitable.
[0012]
The weight average molecular weight of the base polymer (a) needs to be 5,000 to 200,000, preferably 30,000 to 120,000, and more preferably 50,000 to 100,000. If the weight average molecular weight is less than 5,000, sufficient film retention cannot be obtained when the film is formed by coating and drying, which is not suitable for causing edge fusion. If the weight average molecular weight exceeds 200,000, sufficient developability is obtained. It is unsuitable because it causes poor resolution.
[0013]
Specific examples of the base polymer (a) include acrylic resins, polyester resins, polyamide resins, polyurethane resins, and epoxy resins.
[0014]
Among these, acrylic (copolymer) resins based on (meth) acrylate and copolymerized with ethylenically unsaturated carboxylic acid and other copolymerizable monomers, acetoacetyl group-containing acrylic (copolymer) Combined) resin is preferably used as the base polymer (a).
[0015]
(Meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate. , Benzyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, and the like.
[0016]
As the ethylenically unsaturated carboxylic acid, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid are preferably used. In addition, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, or anhydrides and half thereof. Esters can also be used. Of these, acrylic acid and methacrylic acid are particularly preferred.
[0017]
The ethylenically unsaturated compound (b) of the present invention contains 50% by weight to 80% by weight of ethylene oxide-modified trimethylolpropane triacrylate in (b), and further includes 60% by weight to 80% by weight. It is preferable, and it is particularly preferably 65 to 80% by weight. If the content is less than 50% by weight, good fine wire adhesion cannot be obtained, which is not preferable.
[0018]
The ethylene oxide-modified trimethylolpropane triacrylate is represented by the following general formula (1).
[Chemical 1]

However, l, m, and n are 0 or a positive number.
[0019]
As the ethylenically unsaturated compound other than the ethylene oxide-modified trimethylolpropane triacrylate, a polyfunctional monomer or a monofunctional monomer may be used alone or in combination of two or more.
Specific examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and butylene. Glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, 2,2-bis (4- (meth) acryloxydiethoxy Enyl) propane, 2,2-bis- (4- (meth) acryloxypolyethoxyphenyl) propane, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, ethylene glycol diglycidyl ether di (meth) Examples include acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, and glycerin polyglycidyl ether poly (meth) acrylate, preferably propylene glycol di (meth) acrylate and trimethylolpropane. Tri (meth) acrylate is used.
[0020]
Specific examples of the monofunctional monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2 -(Meth) acryloyloxy-2-hydroxypropyl phthalate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, half of phthalic acid derivative ( (Meth) acrylate, N-methylol (meth) acrylamide and the like can be mentioned. Preferably, 2-phenoxy-2-hydroxypropyl (meth) acrylate and phthalic acid derivative half (meth) acrylate are used.
[0021]
The ratio of the ethylenically unsaturated compound (b) to 100 parts by weight of the base polymer (a) is preferably selected from the range of 25 to 100 parts by weight, particularly 35 to 75 parts by weight. When the ratio of the ethylenically unsaturated compound (b) exceeds 100 parts by weight, it is not preferable because a sufficient viscosity that can withstand long-term storage after drying cannot be obtained, and an edge fusion from which the resist flows out from the slit roll end face is caused. If the ratio of the unsaturated compound (b) is less than 25 parts by weight, the viscosity after drying becomes too high, and due to insufficient flexibility, a chip appears during cutting, and due to insufficient crosslinking component, a good pattern shape is obtained by development. I can't get it.
[0022]
The self-cleaving initiator (c) is represented by the following general formula (2), specifically, benzoin, benzoin methyl ether, benzoyl isopropyl ether, benzoin isobutyl ether, benzoin butyl ether, 2,2-dihydroxy- Examples include 2-phenylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 2,2-diethoxy-2-phenylacetophenone.
[Chemical 2]

[Wherein R ¹ represents a phenyl group or a substituted phenyl group, R ² represents hydrogen, a hydroxyl group, an alkoxy group, halogen, and R ³ represents a hydroxyl group or an alkoxy group. ]
[0023]
The amount of the self-cleaving initiator (c) is not particularly limited, but the self-cleaving initiator (c) is preferably 1.0 to 15 parts by weight with respect to 100 parts by weight of the base polymer (a). Is preferably contained in an amount of 2 to 12 parts by weight. When the self-cleavage initiator (c) is less than 1.0 part by weight, a large amount of exposure is required for sufficient curing, and conversely 15 parts by weight. If it is more than the range, the plasticizer effect is large, which causes edge fusion, which is not preferable.
[0024]
Furthermore, in the present invention, the self-cleaving initiator (c) and a photopolymerization initiator can be used in combination. Examples of the photopolymerization initiator include benzyldiphenyl disulfide, dibenzyl, diacetyl, anthraquinone, naphthoquinone, 3,3 ′. -Dimethyl-4-methoxybenzophenone, benzophenone, p, p'-bis (dimethylamino) benzophenone, p, p'-bis (diethylamino) benzophenone, pivaloin ethyl ether, 1,1-dichloroacetophenone, pt- Butyldichloroacetophenone, hexaarylimidazole dimer, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, 2,2-dichloro-4-phenoxyacetophenone, phenylglyoxylate, α-hydroxyisobutylphenol , Dibezoparone, 1- (4-isopropylphenyl) -2-hydroxy-2-methyl-1-propanone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, tribromophenylsulfone , Tribromomethylphenyl sulfone, acridine, 9-phenylacridine, 2,4-trichloromethyl- (4'-methoxyphenyl) -6-triazine, 2,4-trichloromethyl- (4'-methoxynaphthyl) -6 Examples include triazine and the like.
[0025]
Furthermore, in the present invention, it is also useful to blend N-phenylglycine (d) for the purpose of improving sensitivity, and the blending ratio is 0.1 to 1.0 part by weight, particularly 0, per 100 parts by weight of (a). .2 to 0.5 part by weight is preferable, and if it is less than 0.1 part by weight, the effect of improving the sensitivity cannot be expected, and if it exceeds 1.0 part by weight, the base dye is discolored in an unexposed state.
[0026]
In the present invention, it is also useful to blend 2,4,5-triphenylimidazole dimer (e) for the purpose of improving internal curing, and the blending ratio is 0 for 100 parts by weight of (a). .5 to 15 parts by weight, particularly 1.0 to 5.0 parts by weight is preferable, and if it is less than 0.5 parts by weight, sufficient internal curing cannot be obtained, so that the pattern shape after development is deteriorated, which is not preferable. If the amount exceeds 2, the 2,4,5-triphenylimidazole dimer (e) crystallizes and precipitates during storage in an unexposed state, which is not preferable.
[0027]
In addition, the photosensitive resin composition (II) of the present invention includes dyes (coloring, color development), adhesion imparting agents, plasticizers, antioxidants, thermal polymerization inhibitors, solvents, surface tension modifiers, stabilizers. Additives such as chain transfer agents, antifoaming agents, and flame retardants can be added as appropriate.
[0028]
The photosensitive resin composition (II) thus obtained can be widely used as an etching resist or a plating resist when processing relief patterns, printed wiring boards (PWP), transparent electrodes, etc. It is most suitable for the manufacture of relief patterns.
[0029]
When the protective film (III) used in the present invention is used in the form of a roll of photoresist film, the photosensitive resin composition layer having adhesiveness is transferred to the support film, or the photosensitive resin composition layer. In order to prevent the wall from adhering to the photosensitive resin composition layer, it is used by being laminated on the photosensitive resin composition layer. Examples of such a protective film include a polyester film, a polyethylene film, a polypropylene film, a polyvinyl alcohol film, and a Teflon film, but the present invention is not limited to such examples. In addition, there is no limitation in particular about the thickness of this protective film, What is necessary is just normally 10-50 micrometers, especially 10-30 micrometers.
[0030]
Thus, the present invention provides a photoresist film in which the support film (I), the photosensitive resin composition layer (II), and the protective film (III) are sequentially laminated.
Next, the production of the photoresist film of the present invention and the production of a thick film relief pattern using the photoresist film will be described.
[0031]
(Stratification method)
After coating the photosensitive resin composition (II) on a support film (I) such as a polyester film, a polypropylene film, a polystyrene film, or a vinylon film, a protective film (III ) To form a photoresist film.
[0032]
(exposure)
To form an image with a photoresist film, the adhesive force between the support film (I) and the photosensitive resin composition layer (II) and the adhesive force between the protective film (III) and the photosensitive resin composition layer (II) After the film with the lower adhesive strength is peeled off, the photosensitive resin composition layer (II) side is attached to a metal surface such as a copper surface of a copper-clad substrate, and then the pattern is formed on the other film. Exposure is performed with the mask in close contact. When the photosensitive resin composition does not have adhesiveness, the pattern mask can be directly contacted with the photosensitive resin composition layer (II) after the other film is peeled off for exposure.
[0033]
In addition, as the shape and dimension of the thick film fine pattern of the present invention, the width of the relief pattern is 10 to 200 μm, the distance between adjacent patterns is 10 μm or more, and the ratio of width to height is 1 / 1.5 or less. , Preferably 1 / 2.0 or less. The cross-sectional shape of the pattern is substantially rectangular, the angle between the side surface and the substrate is 90 ° ± 10 ° (80 ° to 100 °), and the distance between adjacent patterns is 10 μm or more.
In order to form a thick resist suitable for the present invention as described above, it is often difficult to obtain a desired thick film by a single operation. Therefore, in the lamination of the dry film described above, a method of obtaining a desired thick film by performing a multi-stage laminating operation that repeats an operation of transferring the resist formed on the base film onto the substrate is recommended. Furthermore, a thick film resist having a thickness of 100 μm or more can be easily formed.
[0034]
The exposure is usually performed by ultraviolet irradiation, and as a light source at that time, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, or the like is used. After the ultraviolet irradiation, heating can be performed as necessary to complete the curing.
[0035]
(developing)
After the exposure, the film on the resist is peeled off and then developed. Since the photosensitive resin composition (II) layer is a dilute alkali development type, development after exposure is performed using a dilute aqueous solution of about 0.3 to 2% by weight of alkali such as sodium carbonate and potassium carbonate. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.
[0036]
(Etching, plating)
Then, it etches in accordance with a conventional method normally using acidic etching liquid, such as a cupric chloride-hydrochloric acid aqueous solution and a ferric chloride-hydrochloric acid aqueous solution. Rarely, an ammonia-based alkaline etching solution is also used. In the plating method, pretreatment is performed using a pretreatment agent such as a degreasing agent or a soft etching agent, and then plating is performed using a plating solution. Examples of the plating solution include copper plating solution, nickel plating solution, iron plating solution, silver plating solution, gold plating solution, tin plating solution, cobalt plating solution, zinc plating solution, nickel cobalt plating solution, and solder plating solution.
[0037]
(Removal removal of cured resist)
After the etching process or the plating process, the remaining cured resist is peeled off. Stripping and removing the cured resist is performed using an alkali stripping solution made of an aqueous alkali solution having a concentration of about 0.5 to 5% by weight such as sodium hydroxide or potassium hydroxide.
[0038]
The photoresist film of the present invention is a base film (a) having a specific haze value (I) / base polymer (a) having an acid value of 95 to 250 mgKOH / g and a weight average molecular weight of 5,000 to 200,000, and an ethylene oxide-modified trimethylolpropane. Since it consists of a photosensitive resin composition layer (II) / protective film (III) containing an ethylenically unsaturated compound (b) containing 50 wt% or more of triacrylate and a self-cleaving initiator (c), It has excellent sensitivity, resolution, adhesion between the substrate and the resist, etching resistance such as no penetration of the conductor and coating of the conductor, and excellent plating performance without plating line roughness at the time of plating. In addition, a thick fine film pattern can be formed.
[0039]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
Unless otherwise specified, “%” and “part” are based on weight.
Example 1
[Preparation of photosensitive resin composition]
100 parts of the following base polymer (a), 67 parts of the following ethylenically unsaturated compound (b), 10 parts of 2,2′-dimethoxy-2-phenylacetophenone (c), N-phenylglycine (d) 0. 4 parts and 3.5 parts of 2,4,5-triphenylimidazole dimer (e) were blended and mixed well to prepare a photosensitive resin composition.
[0040]
Base polymer (a)
A copolymer having a copolymerization ratio of methyl methacrylate / n-butyl methacrylate / methacrylic acid of 50/25/25 on a weight basis (acid value 163 mgKOH / g, glass transition point 94 ° C., weight average molecular weight 70,000).
Ethylenically unsaturated compound (b)
A monomer mixture consisting of 67% ethylene oxide-modified trimethylolpropane triacrylate and 33% polypropylene glycol diacrylate.
[0041]
The dope of the photosensitive resin composition was coated on a support film (I) (thickness 20 μm) made of a polyethylene terephthalate film (PET film) having a haze value of 0.1% using an applicator having a gap of 10 mils, After standing at room temperature for 1 minute and 30 seconds, each was dried in an oven at 60 ° C., 90 ° C., and 110 ° C. for 3 minutes to form a dry film with a resist thickness of 50 μm, and a protective film made of polyethylene film (thickness: 23 μm) was laminated. A photoresist film was obtained.
Next, a stainless steel substrate having a thickness of 2 mm subjected to surface cleaning with methyl ethyl ketone was heated to 60 ° C., and the photoresist film obtained above was laminated on the surface while peeling off the protective film. Thereafter, the PET film was peeled off, the lamination was performed again, and the same laminating operation was repeated four times in total to form a resist having a thickness of 200 μm on the stainless steel substrate.
[0042]
Next, exposure of the obtained base material with a 2 kW mercury short arc lamp (parallel light source) with a numerical value of 9 on a stove 21-step tablet (a negative film made so that the amount of light transmission decreases stepwise) Exposure was carried out in a quantity. After 15 minutes after exposure, the PET film is peeled off and sprayed with a 0.5% sodium carbonate aqueous solution at 20 ° C. for 1.5 times the development time of the break point (the time during which the unexposed part is completely dissolved). Unexposed portions were dissolved and removed to obtain a cured resin image.
[0043]
And after plating this base material with a nickel plating solution, it sprayed at 1.5 kg / cm < ² > with 3% sodium hydroxide aqueous solution of 60 degreeC, and it peeled and formed the image.
In the present invention, the following items were evaluated as follows.
[0044]
(A) With the edge fusion PET film laminated, the prepared resist was slit and rolled into a width of 300 mm and a length of 120 m, and the roll was left sideways in a constant temperature and humidity controller at 30 ° C. and 60 RH% under light shielding. Then, the resist soaking of the end face was visually evaluated as follows.
○ ... No soaking even after 3 days.
× ・ ・ ・ Checked out while standing for 3 days.
[0045]
(B) Sensitivity After removing the cover film from the 200 μm-thick resist provided on the stainless steel substrate, the substrate is sprayed with 0.5 wt% sodium carbonate, 20 ° C. developer at a spray pressure of 0.5 kg / cm ^2. The time until the surface is visible is the minimum development time,
The exposure dose (mj / cm ² ) giving Step 9 was determined when developing with a stiffer 21-step step doublet in 1.5 times the minimum development time.
[0046]
(C) Resolution The width of a resolvable space of a pattern having a line width of 200 μm at the above exposure amount was measured.
[0047]
(D) After forming a pattern of peelable line / space = 200 μm / 200 μm, nickel plating with a height of 180 to 200 μm was performed on the space, and then 3% sodium hydroxide aqueous solution at 60 ° C. was added to 1.5 kg / cm It sprayed by ² and peeled and evaluated as follows.
○: Peeled within 30 minutes, and part of the peeled piece does not remain in the Ni-plated part.
Δ: Peeling within 30 minutes, but part of the peeling piece adheres to the Ni plating side surface.
×: Does not peel off in 30 minutes.
[0048]
(E) Adhesion Line width of 10 to 200 μm Using a pattern mask provided with a line every 5 μm (only one line—space width ∞), development is performed in the same manner as in the above-described resolution evaluation, and adhesion is good. The minimum line width (μm) was examined.
[0049]
(F) Plating line / space = After development of 400 μm / 300 μm, the resist pattern was plated and the resist was peeled off, and then the substrate was observed with a magnifying microscope to visually evaluate the plating line roughness. The evaluation criteria are as follows.
○ ・ ・ ・ No jaggedness △ ・ ・ ・ There is a jaggedness of less than 5 μm at the end × ・ ・ ・ There is a jaggedness of 5 μm or more at the end [0050]
Example 2
In Example 1, except for removing N-phenylglycine (d), a photosensitive resin composition was prepared according to Example 1, and further a PET film (I) having a haze value of 1.4% (thickness 20 μm). The same evaluation as described above was performed except that was used.
[0051]
Example 3
In Example 1, except that 2,4,5-triphenylimidazole dimer (e) was removed, a photosensitive resin composition was prepared according to Example 1, and PET having a haze value of 1.4% was further prepared. The same evaluation as described above was performed except that the film (I) (thickness 20 μm) was used.
[0052]
Example 4
In Example 1, a photosensitive resin composition was prepared according to Example 1 except that N-phenylglycine (d) and 2,4,5-triphenylimidazole dimer (e) were removed. The same evaluation as above was performed except that the PET film (I) having a haze value of 1.4% (thickness 20 μm) was used.
[0053]
Example 5
Example 1 is the same as Example 1 except that a mixture of monomers consisting of 80% ethylene oxide-modified trimethylolpropane triacrylate and 20% polypropylene glycol diacrylate was used as the ethylenically unsaturated compound (b). According to the same manner, a photosensitive resin composition was prepared, and the same evaluation as described above was performed except that a PET film (I) having a haze value of 1.4% (thickness 20 μm) was used.
[0054]
Example 6
Except for using 125 parts of the following base polymer (a), a photosensitive resin composition was prepared according to Example 1, and a PET film (I) having a haze value of 1.0% (thickness: 16 μm) was used. Were performed in the same manner and evaluated in the same manner as described above.
Base polymer (a)
A copolymer having a copolymerization ratio of methyl methacrylate / n-butyl acrylate / 2-ethylhexyl acrylate / methacrylic acid of 48/10/20/22 on a weight basis (acid value 143 mgKOH / g, glass transition point 40.1 ° C., Weight average molecular weight 75,000).
[0055]
Comparative Example 1
In Example 1, according to Example 1 except that a mixture of monomers composed of 40% ethylene oxide-modified trimethylolpropane triacrylate and 60% polypyrylene glycol diacrylate was used as the ethylenically unsaturated compound (b). A photosensitive resin composition was prepared and evaluated in the same manner as described above.
[0056]
Comparative Example 2
In Example 1, a photosensitive resin composition was prepared according to Example 1 except that trimethylolpropane triacrylate was used instead of ethylene oxide-modified trimethylolpropane triacrylate, and evaluation similar to the above was performed.
[0057]
Comparative Example 3
In Example 1, according to Example 1 except that only 2,2′-bis- (4-methacryloxypolyethoxyphenyl) propane (BPE-500) was used as the ethylenically unsaturated compound (b). A photosensitive resin composition was prepared and evaluated in the same manner as described above.
[0058]
Comparative Example 4
A photosensitive resin according to Example 1 except that 1 part of p, p'-bis (diethylamino) benzophenone was used instead of 10 parts of 2,2-dimethoxy-2-phenylacetophenone (c) in Example 1. A composition was prepared and evaluated in the same manner as described above.
[0059]
Comparative Example 5
In Example 1, the photosensitive resin composition was prepared according to Example 1 using the polymer whose acid value is 91 mgKOH / g, and the same evaluation as the above was performed.
[0060]
Comparative Example 6
In Example 1, a photosensitive resin composition was prepared according to Example 1 using a polymer having an acid value of 251 mgKOH / g, and the same evaluation as described above was performed.
[0061]
Comparative Example 7
In Example 1, a photosensitive resin composition was prepared according to Example 1 using the following base polymer (a) having a weight average molecular weight of 3000, and the same evaluation as described above was performed.
Base polymer (a)
A copolymer having a copolymerization ratio of methyl methacrylate / styrene / methacrylic acid of 45/30/25 on a weight basis (acid value 163 mgKOH / g, glass transition point 118 ° C.).
[0062]
Comparative Example 8
A photosensitive resin composition was prepared according to Example 1 using the following base polymer (a) having a weight average molecular weight of 250,000 in Example 1, and the same evaluation as described above was performed.
Base polymer (a)
A copolymer having a copolymerization ratio of methyl methacrylate / n-butyl acrylate / methacrylic acid of 65/10/25 on a weight basis (acid value 163 mg KOH / g, glass transition point 94 ° C.).
[0063]
Comparative Example 9
In Example 1, it carried out similarly except having used PET film with a haze value of 4.0% as support body film (I), and evaluated similarly to the above.
[0064]
The evaluation results of Examples and Comparative Examples are shown in Table 1.
[Table 1]

[0065]
【The invention's effect】
The photoresist film obtained in the present invention is excellent in sensitivity, resolving power, resist releasability, and further has good adhesion to a metal substrate, so that it does not soak into the conductor and does not cover the conductor, and plating during plating. Since it has excellent plating properties such as no line roughness, it is useful as an etching resist or plating resist used in the production of printed wiring boards, lead frames, thick film relief patterns, precision metal processing, and the like.

Claims (5)

In the photoresist film comprising the support film (I) / photosensitive resin composition layer (II) / protective film (III), the haze value of the support film (I) is 0.01 to 1.5%, In addition, the photosensitive resin composition layer (II) has a base polymer (a) having an acid value of 95 to 250 mgKOH / g and a weight average molecular weight of 5,000 to 200,000, an ethylenically unsaturated compound (b), a self-cleavage type start A photoresist film comprising an agent (c) and containing 50 wt% to 80 wt% of ethylene oxide-modified trimethylolpropane triacrylate in (b). 2. The photo of claim 1, wherein the photosensitive resin composition layer (II) further comprises N-phenylglycine (d) and 2,4,5-triphenylimidazole dimer (e). Resist film. The photosensitive resin composition layer (II) contains the ethylenically unsaturated compound (b) with respect to 100 parts by weight of the base polymer (a) having an acid value of 95 to 250 mgKOH / g and a weight average molecular weight of 5,000 to 200,000. 25 to 100 parts by weight, 1.0 to 15 parts by weight of the self-cleaving initiator (c), 0.1 to 1.0 part by weight of N-phenylglycine (d), 2,4,5-triphenylimidazole The photoresist film according to claim 1 or 2, comprising 0.5 to 15 parts by weight of the dimer (e). The photoresist film according to claim 1, which is used for producing a relief pattern. 5. The photoresist film according to claim 4, wherein the width of the relief pattern is 5 to 200 [mu] m, the interval between adjacent patterns is 10 [mu] m or more, and the ratio of width to height is 1 / 1.5 or less. .