JP3674954B2 - Alkaline development type liquid photoresist composition for circuit board formation - Google Patents

Description

【００１１】
【化２】

【００１２】
【化３】

【００１３】
【化４】

【００１４】
【化５】

【００１５】
共重合体Ｉを重合する際に用いられる重合溶媒としては、たとえばメタノール、エタノール等のアルコール類；テトラヒドロフラン、ジオキサン等の環状エーテル類；メチルセロソルブアセテート等のセロソルブエステル類；エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、エチレングリコールジメチルエーテル、エチレングリコールジエチルエーテル、ジエチレングリコールモノメチルエーテル、ジエチレングリコールジメチルエーテル、ジエチレングリコールジエチルエーテルなどの多価アルコールのアルキルエーテル類；トルエン、キシレンなどの芳香族炭化水素類；アセトン、メチルエチルケトン、メチルイソブチルケトンなどのケトン類；酢酸エチル、酢酸ブチル、プロピレングリコールメチルエーテルアセテートなどのエステル類等が挙げられる。これらのうち、環状エーテル類、多価アルコールのアルキルエーテル類、エステル類が好ましい。
ラジカル重合における重合触媒としては通常のラジカル重合開始剤が使用でき、たとえば２，２’−アゾビスイソブチロニトリル、２，２’−アゾビス−（２，４−ジメチルバレロニトリル）、２，２’−アゾビス−（４−メトキシ−２，４−ジメチルバレロニトリル）等のアゾ化合物；ベンゾイルペルオキシド、ラウロイルペルオキシド、ｔ−ブチルペルオキシピバレート、１，１’−ビス−（ｔ−ブチルペルオキシ）シクロヘキサン等の有機過酸化物および過酸化水素等を挙げることができる。過酸化物をラジカル重合開始剤に使用する場合、還元剤を組み合わせてレドックス型の開始剤としても良い。
【００１６】
共重合体Ｉの分子量およびその分布は、本発明の組成物の溶液を均一に塗布することが可能である限り、特に限定されるものではない。
２．成分（Ｂ）（以下「エチレン性化合物」と記す。）：
本発明に用いられるエチレン性化合物としては、単官能または多官能のアクリル酸またはメタクリル酸のエステルを好ましいものとして挙げられる。
【００１７】
単官能（メタ）アクリレートとしては、市販品として、たとえばアロニックスＭ−１０１、同Ｍ−１１１、同Ｍ−１１４（東亜合成化学工業（株）製）、ＫＡＹＡＲＡＤ ＴＣ−１１０Ｓ、同ＴＣ−１２０Ｓ（日本化薬（株）製）、Ｖ−１５８、Ｖ−２３１１（大阪有機化学工業（株）製）等を挙げることができる。
２官能（メタ）アクリレートとしては、市販品として、たとえばアロニックスＭ−２１０、同Ｍ−２４０、同Ｍ−６２００（東亜合成化学工業（株）製）、ＫＡＹＡＲＡＤ ＨＤＤＡ、同ＨＸ−２２０、同Ｒ−６０４（日本化薬（株）製）、Ｖ２６０、Ｖ３１２、Ｖ３３５ＨＰ（大阪有機化学工業（株）製）等を挙げることができる。
また３官能以上の（メタ）アクリレートとしては、市販品としては、たとえばアロニックスＭ−３０９、同Ｍ−４００、同Ｍ−４０５、同Ｍ−４５０、同Ｍ−７１００、同Ｍ−８０３０、同Ｍ−８０６０（東亜合成化学工業（株）製）、ＫＡＹＡＲＡＤ ＴＭＰＴＡ、同ＤＰＣＡ−２０、同−３０、同−６０、同−１２０（日本化薬（株）製）、Ｖ−２９５、同−３００、同−３６０、同−ＧＰＴ、同−３ＰＡ、同−４００（大阪有機化学工業（株）製）等を挙げることができる。
これらの化合物は単独でまたは２種以上用いてもよく、共重合体Ｉ１００重量部に対して好ましくは３０〜２００重量部、より好ましくは５０〜１５０重量部である。３０重量部未満であると、感度が低下し易く、２００重量部を越えると、共重合体Ｉとの相溶性が悪くなり、塗膜形成後の塗膜表面に膜荒れを生じることがある。
【００１８】
３．成分（Ｃ）：
本発明に用いられる光重合開始剤としては、エチレン性化合物を反応せしめることが可能な光ラジカル重合開始剤、または共重合体Ｉ内のエポキシ基を反応せしめることが可能な光カチオン重合開始剤等を使用することができる。光ラジカル重合開始剤としては、たとえばベンジル、ジアセチル等のα−ジケトン類；ベンゾイン等のアシロイン類；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等のアシロインエーテル類；チオキサントン、２，４−ジエチルチオキサントン、チオキサントン−４−スルホン酸；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）ベンゾフェノン等のベンゾフェノン類；アセトフェノン、ｐ−ジメチルアミノアセトフェノン、α，α’−ジメトキシアセトキシベンゾフェノン、２，２’−ジメトキシ−２−フェニルアセトフェノン、ｐ−メトキシアセトフェノン、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、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）−ブタン−１−オン等のアセトフェノン類；アントラキノン、１，４−ナフトキノン等のキノン類；フェナシルクロライド、トリブロモメチルフェニルスルホン、トリス（トリクロロメチル）−ｓ−トリアジン等のハロゲン化合物；ジ−ｔ−ブチルパーオキサイド等の過酸化物；２，４，６−トリメチルベンゾイルジフェニルフォスフィンオキサイドなどのアシルフォスフィンオキサイド類等が挙げられる。
【００１９】
上述した種々の光重合開始剤の中で好ましい化合物としては、光ラジカル重合開始剤として、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、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）−ブタン−１−オン等のアセトフェノン類またはフェナシルクロライド、トリブロモメチルフェニルスルホン、２，４，６−トリメチルベンゾイルジフェニルフォスフィンオキサイド、トリス（トリクロロメチル）−ｓ−トリアジン等のハロゲン化合物を挙げることができる。
また、光カチオン重合開始剤としては、以下に示すような市販品を使用することができる。ジアゾニウム塩であるアデカウルトラセットＰＰ−３３（旭電化工業（株）製）、スルホニウム塩であるＯＰＴＯＭＥＲ ＳＰ−１５０、１７０
（旭電化工業（株）製）、メタロセン化合物であるＩＲＧＡＣＵＲＥ２６１（ＣＩＢＡ−ＧＥＩＧＹ社製）等を挙げることができる。
光重合開始剤の使用量は、共重合体Ｉ１００重量部に対して１．０〜５０重量部が好ましく、特に５〜３０重量部が好ましい。１重量部未満であると、酸素によるラジカルの失活（感度の低下）が生じ易く、また５０重量部を越えると、相溶性が悪くなったり、保存安定性が低下したりする。
また保存安定性の面から、光ラジカル重合開始剤のほうがカチオン重合開始剤より好ましい。さらに、これら光ラジカル重合開始剤と光カチオン重合開始剤または光増感剤とを併用することも可能である。
【００２０】
４．有機溶剤：
本発明の組成物には、上述した各成分を均一に混合する目的で有機溶剤を添加することができる。用いる溶剤としては、共重合体Ｉ、エチレン性化合物、光重合開始剤およびエポキシ化合物を均一に溶解させることができ、各成分と反応しないものが用いられる。かかる溶媒としては、たとえばメタノール、エタノール等のアルコール類；テトラヒドロフラン等の環状エーテル類；エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル等のグリコールエーテル類；メチルセロソルブアセテート、エチルセロソルブアセテート等のエチレングリコールアルキルエーテルアセテート類；ジエチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテル、ジエチレングリコールジメチルエーテル等のジエチレングリコール類；プロピレングリコールメチルエーテルアセテート、プロピレングリコールプロピルエーテルアセテート等のプロピレングリコールアルキルエーテルアセテート類；トルエン、キシレン等の芳香族炭化水素類；メチルエチルケトン、シクロヘキサノン、４−ヒドロキシ−４−メチル−２−ペンタノン等のケトン類；２−ヒドロキシプロピオン酸エチル、２−ヒドロキシ−２−メチルプロピオン酸エチル、２−ヒドロキシ−２−メチルプロピオン酸エチル、エトキシ酢酸エチル、ヒドロキシ酢酸エチル、２−ヒドロキシ−３−メチルブタン酸メチル、３−メトキシプロピオン酸メチル、３−メトキシプロピオン酸エチル、３−エトキシプロピオン酸エチル、３−エトキシプロピオン酸メチル、酢酸エチル、酢酸ブチル等のエステル類を用いることができる。
【００２１】
さらに、Ｎ−メチルホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ−メチルホルムアニリド、Ｎ−メチルアセトアミド、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ−メチルピロリドン、ジメチルスルホキシド、ベンジルエチルエーテル、ジヘキシルエーテル、アセトニルアセトン、イソホロン、カプロン酸、カプリル酸、１−オクタノール、１−ノナノール、ベンジルアルコール、酢酸ベンジル、安息香酸エチル、シュウ酸ジエチル、マレイン酸ジエチル、γ−ブチロラクトン、炭酸エチレン、炭酸プロピレン、フェニルセロソルブアセテート等の高沸点溶媒を添加することもできる。
これらの溶剤の中で、溶解性、各成分との反応性および塗膜の形成のしやすさから、エチレングリコールモノエチルエーテル等のグリコールエーテル類；エチルセロソルブアセテート等のエチレングリコールアルキルエーテルアセテート類；２−ヒドロキシプロピオン酸エチル等のエステル類；ジエチレングリコールモノメチルエーテル等のジエチレングリコール類が好適である。
上記溶剤の使用量は、用途、塗布方法に応じて調整することができ、組成物を均一に混合させることができれば特に限定されるものではないが、得られる組成物に対して５０重量％以下、好ましくは１０〜４０重量％である。
【００２２】
５．その他の添加剤：
本発明には、パターンの耐熱性、硬度をさらに向上させる目的で、エポキシ化合物を配合することができる。このようなエポキシ化合物としては、相溶性に影響がない限り限定されるものではないが、好ましくは、ビスフェノールＡ型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、環状脂肪族エポキシ樹脂、グリシジルエステル型エポキシ樹脂、グリシジルアミン型エポキシ樹脂、複素環式エポキシ樹脂の他、オプトマーＳＳ（日本合成ゴム（株）製）のようなグリシジルメタクリレート含有樹脂組成物を挙げる ことができる。これらの中で特に好ましくは、ビスフェノールＡ型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、グリシジルエステル型エポキシ樹脂等である。これらエポキシ化合物の使用量は、共重合体Ｉ１００重量部に対して好ましくは１００重量部以下、より好ましくは１０〜１００重量部である。
【００２３】
本発明の組成物においては、塗布性、消泡性、レベリング性を向上する目的で界面活性剤を配合することもできる。界面活性剤としては、たとえばＢＭ−１０００、ＢＭ−１１００（ＢＭ Ｃｈｅｍｉｅ社製）、メガファックＦ１４２Ｄ、同Ｆ１７２、同Ｆ１７３、同Ｆ１８３（大日本インキ化学工業（株）製）、フロラードＦＣ−１３５、同ＦＣ−１７０Ｃ、同ＦＣ−４３０、同ＦＣ−４３１（住友スリーエム（株）製）、サーフロンＳ−１１２、同Ｓ−１１３、同Ｓ−１３１、同Ｓ−１４１、同Ｓ−１４５（旭硝子（株）製）、ＳＨ−２８ＰＡ、同−１９０、同−１９３、ＳＺ−６０３２、ＳＦ−８４２８（東レシリコーン（株）製）等の名称で市販されているフッ素系界面活性剤を使用することができる。これらの界面活性剤の使用量は、共重合体Ｉ１００重量部に対して好ましくは５重量部以下、より好ましくは０．０１〜２重量部の範囲である。
【００２４】
また、基板との接着性を向上させるために接着助剤を使用することもできる。使用される接着助剤としては、官能性シランカップリング剤が有効である。ここで、官能性シランカップリング剤とは、カルボキシル基、メタクリロイル基、イソシアネート基、エポキシ基等の反応性置換基を有するシランカップリング剤を意味し、具体例としてはトリメトキシシリル安息香酸、γ−メタクリロキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、ビニルトリメトキシシラン、γ−イソシアネートプロピルトリエトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、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等を挙げることができる。
これらの接着助剤は、単独でも２種以上の組み合わせでも使用することができる。その配合量は、共重合体Ｉ１００重量部当たり２０重量部以下が好ましく、より好ましくは０．０５〜１０重量部の範囲である。
【００２５】
さらに、本発明の組成物には必要に応じて、充填材、着色剤、粘度調整剤などを添加することができる。
充填材としては、シリカ、アルミナ、タルク、ベントナイト、ジルコニウムシリケート、粉末ガラスなどを挙げることができる。
着色剤としては、アルミナ白、クレー、炭酸バリウム、硫酸バリウム等の体質顔料；亜鉛華、群青、紺青、酸化チタン、クロム酸亜鉛、ベンガラ、カーボンブラックなどの無機顔料；ブリリアントカーミン６Ｂ、パーマネントレッド６Ｂ、パーマネントレッドＲ、フタロシアニンブルー、フタロシアニングリーンなどの有機顔料；マゼンタ、ローダミンなどの塩基性染料；ダイレクトスカーレット、ダイレクトオレンジ等の直接染料；ローセリン、メタニルイエロー等の酸性染料などが挙げられる。
粘度調整剤として、ベントナイト、シリカゲル、アルミニウム粉末などを挙げることができる。
これらの添加剤は、組成物の本質的な特性を損なわない範囲、好ましくは、得られる組成物に対して５０重量％以下であることが好ましい。
【００２６】
本発明の組成物の調製は、充填材、着色剤を添加しない場合には、通常の方法で混合、攪拌するだけでよく、充填材、着色剤を添加する場合には、ディゾルバー、ホモジナイザー、３本ロールミル等の分散機を用い分散、混合させればよい。また必要に応じて、メッシュ、メンブレンフィルターなどを用いてろ過してもよい。
【００２７】
次に、本発明の組成物の使用方法について説明する。
１．塗膜の形成方法：
本発明においては、上述した組成物溶液を所定の被処理基板上に塗布し、プレベークにより溶媒を除去することによって所望の塗膜を形成することができる。被処理基板上への塗布方法は特に限定されず、スピンコート法、ロールコート法、スクリーン印刷法、アプリケーター法などの方法を採用することができる。
なお、本発明の組成物の塗膜の乾燥条件は、組成物各成分の種類、配合割合、塗布膜厚等によって異なるが、通常は７０〜９０℃で５〜２０分間程度である。乾燥時間が短すぎると、現像時の密着状態が悪くなり、また長すぎると、熱かぶりによる解像度の低下を招く。
【００２８】
２．露光方法：
得られた塗膜に所定のパターンのマスクを介して、２００〜５００ｎｍの紫外線または可視光線を照射することにより、必要な部分のみ光硬化させることできる。
これらの活性光線の線源として、低圧水銀灯、高圧水銀灯、超高圧水銀灯、メタルハライドランプ、アルゴンガスレーザーなどを用いることができる。また、Ｘ線、電子線なども活性エネルギー線として組成物の硬化に用いることができる。
露光量は、組成物各成分の種類、配合量、乾燥膜厚によってことなるが、高圧水銀灯使用の場合、１，０００〜５，０００ J/m ² （（株）オーク製ＵＶ４２）である。
【００２９】
３．現像方法：
本発明における現像方法としては、アルカリ性水溶液を現像液として用いて、不要な部分を溶解、除去し、露光部分のみ残存させ、パターンを形成させる。
本発明における現像液としては、たとえば水酸化ナトリウム、水酸化カリウム、炭酸ナトリウム、ケイ酸ナトリウム、メタケイ酸ナトリウム、アンモニア水、エチルアミン、ｎ−プロピルアミン、ジエチルアミン、ジ−ｎ−プロピルアミン、トリエチルアミン、メチルジエチルアミン、ジメチルエタノールアミン、トリエタノールアミン、テトラメチルアンモニウムヒドロキシド、テトラエチルアンモニウムヒドロキシド、ピロール、ピペリジン、１，８−ジアザビシクロ［５．４．０］−７−ウンデセン、１，５−ジアザビシクロ［４．３．０］−５−ノナン等のアルカリ類の水溶液を使用することができる。
また、上記アルカリ類の水溶液にメタノール、エタノール等の水溶性有機溶媒や界面活性剤を適当量添加した水溶液を現像液として使用することもできる。
現像時間は、組成物各成分の種類、配合割合、組成物の乾燥膜厚によってことなるが、通常３０〜１８０秒間であり、また現像の方法は液盛り法、ディッピング法、パドル法、スプレー現像法等のいずれでも良い。
現像後は、流水洗浄を３０〜９０秒間行い、エア−ガン等を用いて風乾させたり、オーブン中で乾燥させて、所望のパターンを得ることができる。
【００３０】
４．後処理：
本発明の組成物は、前記活性光線または活性エネルギー線の照射のみでも、十分に硬化させることができるが、用途に応じてさらに、露光（以下、「後露光」と記す。）、加熱硬化させることができ、特に永久膜として用いる場合には好ましい。
後露光としては、前記露光方法と同様の方法で行うことができ、露光量は特に限定されるものではないが、高圧水銀灯使用の場合、１，０００〜１０，０００ J/m ² （（株）オーク製ＵＶ４２）が好ましい。
また、加熱硬化の方法は、ホットプレート、オーブン等の加熱装置を用いて、所定の温度たとえば１２０〜２００℃で所定の時間、たとえばホットプレート上なら１０〜６０分間、オーブン中では３０〜９０分間加熱処理をさせればよい。こうすることによって、さらに良好な特性を有する硬化物を得ることができ
る。
【００３１】
【実施例】
以下に本発明を実施例により具体的に説明するが、本発明はこれに限定されるものではない。また、特にことわりの無い限り、部は重量部、％は重量％を示す。
（１） 共重合体Ｉの合成
共重合体Ｉの実施例として共重合体１〜８を、比較例として共重合体９〜１４を合成した。以下に詳細を述べる。
【００３２】
共重合体１の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビスイソブチロニトリル１０．０ｇと溶媒としてジエチレングリコールジメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、メタクリル酸４２．５ｇ、メタクリル酸グリシジル１００．０ｇ、ジシクロペンタニルメタクリレート９５．０ｇ、ブタジエン１２．５ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００３３】
共重合体２の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビス−２，４−ジメチルバレロニトリル１０．０ｇと溶媒としてジオキサン５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、クロトン酸４５．０５ｇ、メタクリル酸−６，７−エポキシヘプチル１０１．３５ｇ、イソボルニルメタクリレート６３．０８ｇ、スチレン２２．５３ｇ、イソプレン１８．０３ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００３４】
共重合体３の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤としてベンゾイルペルオキシド１０．０ｇと溶媒としてジエチレングリコールモノメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、イタコン酸５１．８８ｇ、α−エチルアクリル酸−６，７−エポキシヘプチル８２．５５ｇ、ベンジルメタクリレート８９．６３ｇ、α−メチルスチレン１１．８ｇ、ブタジエン１４．１６ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００３５】
共重合体４の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビスイソブチロニトリル１０．０ｇと溶媒としてジエチレングリコールジメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、メタクリル酸６３．６８ｇ、メタクリル酸−６，７−エポキシヘプチル４７．６２ｇ、ｓｅｃ−ブチルメタクリレート１１４．２８ｇ、スチレン１１．９ｇ、イソプレン１１．９ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００３６】
共重合体５の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビス−２，４−ジメチルバレロニトリル１０．０ｇと溶媒としてジオキサン５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、クロトン酸６７．５ｇ、α−エチルアクリル酸−６，７−エポキシヘプチル５０．０ｇ、マレイン酸ジエチル１０５．０ｇ、α−メチルスチレン２５．０ｇ、ブタジエン２．５ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００３７】
共重合体６の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤としてベンゾイルペルオキシド１０．０ｇと溶媒としてジエチレングリコールモノエチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、イタコン酸６４．２８ｇ、メタクリル酸グリシジル９５．２５ｇ、メチルメタクリレート３０．９５ｇ、スチレン４７．６３ｇ、イソプレン１１．９０ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００３８】
共重合体７の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビスイソブチロニトリル１０．０ｇと溶媒としてジエチレングリコールジメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、メタクリル酸６７．５ｇ、メタクリル酸グリシジル５０．０ｇ、ジシクロペンタニルメタクリレート８０．０ｇ、スチレン５０．０ｇ、ブタジエン２．５ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４０】
共重合体９の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビスイソブチロニトリル１０．０ｇと溶媒としてジエチレングリコールジメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、イタコン酸８５．４５ｇ、ジシクロペンタニルメタクリレート１０１．２８ｇ、スチレン６３．３ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４１】
共重合体１０の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビス−２，４−ジメチルバレロニトリル１０．０ｇと溶媒としてジエチレングリコールモノメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、クロトン酸７１．０５ｇ、イソボルニルメタクリレート１１３．１５ｇ、α−メチルスチレン５２．６３ｇ、ブタジエン１３．１５ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４２】
共重合体１１の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤としてベンゾイルペルオキシド１０．０ｇと溶媒としてジオキサン５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、メタクリル酸７５．７５ｇ、ｓｅｃ−ブチルメタクリレート１４３．９５ｇ、ブタジエン３０．０ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４３】
共重合体１２の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビスイソブチロニトリル１０．０ｇと溶媒としてジエチレングリコールジメチルエーテル５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、メタクリル酸グリシジル６９．４５ｇ、マレイン酸ジエチル１１１．１ｇ、スチレン６９．４５ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４４】
共重合体１３の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤として２，２’−アゾビス−２，４−ジメチルバレロニトリル１０．０ｇと溶媒としてエチルセルセロブアセテート５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、α−エチルアクリル酸−６，７−エポキシヘプチル３４．２５ｇ、ベンジルメタクリレート１４５．２５ｇ、α−メチルスチレン６８．５ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４５】
共重合体１４の合成
ドライアイス／メタノール還流器の付いたフラスコを窒素置換した後、重合開始剤としてベンゾイルペルオキシド１０．０ｇと溶媒としてプロピレングリコールメチルエーテルアセテート５１０．０ｇを仕込み、重合開始剤が溶解するまで攪拌する。引き続いて、イタコン酸６４．９３ｇ、アクリロニトリル１０３．９ｇ、スチレン６４．９３ｇ、イソプレン１６．２３ｇを仕込んだ後、ゆるやかに攪拌を始めた。その後、溶液の温度を８０℃に上昇させ、この温度を５時間保持した後、９０℃で１時間加熱させて重合を終結させた。その後、反応生成物を多量のメタノールに滴下して反応物を凝固させた。この凝固物を水洗後、凝固物と同重量のテトラヒドロフランに再溶解し、多量のメタノールで再度凝固させた。この再溶解−凝固操作を計３回行った後、得られた凝固物を６０℃で４８時間真空乾燥し、目的とする共重合体を得た。
【００４６】
（２） 回路基板形成用アルカリ現像型液状フォトレジスト組成物の調製
成分（Ａ）、成分（Ｂ）、成分（Ｃ）、溶剤およびその他の添加剤を表１の如く配合して、該組成物を得た。表１において、成分（Ａ）の１〜７は本発明の共重合体であり、９〜１５は本発明の共重合体ではない。尚、成分（Ａ）の１５は、従来より、アルカリ現像型フォトレジスト組成物において、しばしば用いられるビスフェノールＡ型エポキシアクリレートである。調製した組成物のうち、充填材および着色剤を配合しないものについては、ヘンシェルミキサーで混合、攪拌を行い、充填材および着色剤を配合したものについては、充填材および着色剤以外の成分をヘンシェルミキサーで混合、攪拌し、引き続いて充填材および着色剤をこれに添加し、再度、混合、攪拌を行った後、３本ロールミルで混練した。
【００４７】
（３） 諸特性の評価
▲１▼ 厚膜解像性の評価
表２の組成物のうち充填材および着色剤を含まない組成物１〜９、１５〜２０および２４について行った。
Ｓi Ｏ₂ ガラス基板上にスピンナーを用いて、該組成物を塗布した後、８０℃で１０分間ホットプレート上プレベークして、膜厚３０μm の塗膜を形成した。次に、解像度測定用のネガマスク（TOPPAN-TEST-CHART-N)を介して、高圧水銀灯（ミカサ電機製ＭＬ−３型）を用いて３，０００J/m²（オーク製作所製ＵＶ−４２）露光した。これを、０．５％のテトラメチルアンモニウムヒドロキシド水溶液中で現像した。その後流水洗浄し、窒素ブローして残存パターンを得た。これを光学顕微鏡で観察し、解像度を測定した。また、現像後の膜厚測定（ＨＥＲＺ社製αステップ１００）し、残膜率（％）を求めた。ここで、残膜率とは、現像後の膜厚をプレベーク後の膜厚で除して、１００をかけた値である。結果を表２に示す。
【００４８】
▲２▼ 電気めっき用レジストとしての性能評価
電気めっき用レジストとしての性能を評価する為、レジストパターンの電気めっき液耐性を調べた。また、実際に電気めっき法によるバンプ形成を行い、形成されたパンブの状態を調べた。
まず、レジストパターンの電気めっき液耐性について説明する。表１の組成物のうち組成物１〜９、１５〜２０および２４を用い、ステンレス（ＳＵＳ３０４）基板上に▲１▼と同じ方法で膜厚３０μm のレジストパターンを得たのち、１５０℃で３０分間ホットプレート上で加熱硬化させ、試験体とした。金めっき液、ニッケルめっき液、銅めっき液の各めっき液の攪拌液中に６０℃で６０分間、試験体を浸漬後、これを取り出し、流水洗浄の後乾燥し、被処理試験体を得た。被処理試験体を走査型電子顕微鏡で観察し、レジストパターンの状態を観察し、電気めっき液耐性を評価した。
次に、別に用意したステンレス基板を用い、露光において、５０μm ×５０μm の正方形が陰影部として描かれたマスクを用いた以外は上記と同じ方法、条件で試験体を得、これを用いてバンプ形成のテストを実施した。試験体のレジストパターンには５０μm ×５０μm の凹形状が形成されている。各めっき液を用い、６０℃で４０〜６０分かけて電気めっきを行った。次いで、電気めっきを施した試験体からレジストを剥離する為に、剥離液の攪拌液中に該試験体を５０℃で６０分間浸漬してレジストを剥離した。レジストを剥離したのち、基板上に形成された５０μm ×５０μm のバンプを走査型電子顕微鏡で観察した。
各めっき液および剥離液の仕様を以下に示し、結果を表２に示す。
【００４９】
【表１】

【００５０】
【表２】

【００５１】
（電解金めっき液の仕様）
クエン酸ナトリウム ： １００ｇ／Ｌ
ＫＡｕ（ＣＮ)₂ ： ８ｇ／Ｌ
スルファミン酸ニッケル： ３ｇ／Ｌ
酢酸亜鉛 ０．５ｇ／Ｌ
水 ： 全体が１Ｌ（リットル）になる量
ｐＨ ： ４．５
電流密度 ： ２．０Ａ／ｄｍ²
（電解ニッケルめっき液の仕様）
塩化ニツケルル ： １００ｇ／Ｌ
ほう酸 ： ８ｇ／Ｌ
スルファミン酸ニッケル： ６００ｇ／Ｌ
水 ： 全体が１Ｌ（リットル）になる量
ｐＨ ： ４．０
電流密度 ： ３．０Ａ／ｄｍ²
（電解銅めっき液の仕様）
硫酸銅 ： ２１０ｇ／Ｌ
硫酸 ： ５２ｇ／Ｌ
水 ： 全体が１Ｌ（リットル）になる量
ｐＨ ： １．０
電流密度 ： ３．０Ａ／ｄｍ²
（剥離液の組成）
フェノール ： ２５部
ジメチルスルフォキシド： ２０部
オルトジクロルベンゼン： ５５部
【００５２】
▲３▼ 無電解めっき用レジストとしての性能評価
無電解めっき用レジストとしての性能を評価する為、実際に無電解銅めっきを行い、形成された銅の配線パターンの状態、めっき後のレジストパターンの状態を調べた。以下に詳細を説明する。
活性化処理を施したガラスエポキシ基板に、３０５メッシュのポリエステルスクリーンを用いて、表２の組成物のうち組成物１１〜１３、２１〜２３および２５をスクリーン印刷して塗布し、８０℃で１０分間ホットプレート上でプレベークして、膜厚３５μm の塗膜を得た。次に、露光においてＪＩＳ−Ｚ−３１９７（２形）に準ずるくし形電極パターンが陰影部分として描かれているマスクを用いた以外は、▲１▼と同じ方法、条件でレジストパターンを得た。その後１０，０００J/m²の後露光を行い、さらに１５０℃、２時間の熱硬化を施して試験体とした。試験体を無電解銅めっき液に６０℃で２４時間浸漬し、くし形電極上の無電解銅めっきを形成させた。この試験体は、フルアディティブ法によるプリント回路基板に相当する。実体顕微鏡により、形成された銅の配線パターンの形状、レジストパターンの劣化状態を観察した。また、無電解銅めっき工程後の試験体について、パターンの形成されている部分以外を用いて、クロスカット試験を行い、密着性の評価とした。
下記にめっき液の仕様を示し、表３に結果を示す。
【００５３】
【表３】

【００５４】
（無電解銅めっき液の仕様）
硫酸銅 ： １０ｇ／Ｌ
エチレンジアミン４酢酸： ３０ｇ／Ｌ
３５％ホルマリン ： ４ｍｌ／Ｌ
ポリエチレングリコール（分子量４００）： ３ｇ／Ｌ
ジピリジル ： ４０ｍｇ／Ｌ
水酸化ナトリウム ：ｐＨ１３となる量
水 ： 全体が１Ｌ（リットル）になる量
【００５５】
▲４▼ 層間絶縁膜、回路保護膜としての性能評価
次に、層間絶縁膜、回路保護膜としての性能を評価する為に、レジスト層の表面絶縁抵抗、レジストパターンの半田耐熱性について調べた。まず、▲３▼で作成したレジストパターンと無電解めっきよりなるフルアディティブ基板を試験体に用いて、１００Ｖで１分印加の条件で初期表面絶縁抵抗値および４０℃、９０％、９６時間の吸湿処理後の表面絶縁抵抗値を測定した（ＪＩＳ Ｚ３１９７に準拠）。半田耐熱性については、表面絶縁抵抗値の測定に用いたものと同一の組成物について、▲３▼と同一の方法および条件でガラスエポキシ基板上に３５μmレジスト塗膜を得た後、露光において、▲２▼で用いたマスクを用いた以外は▲３▼と同一の方法および条件でレジストパターンを得、さらに▲３▼の方法により、レジストパターンの後処理を行い試験体を得た。
試験体を錫６０％、鉛４０％よりなる２６０℃の半田浴に１０秒間浸漬させ、その後室温に戻す操作を４回繰り返した後、走査型電子顕微鏡でレジストパターンの損傷を調べた。表３に結果を示す。
【００５６】
表２によれば、本発明の回路基板形成用アルカリ現像型液状フォトレジスト組成物：実施例１−１〜１−９は、電気めっき工程中で、優れた形状保持性を示し、良好なバンプを形成することができた。また、膜厚３０μｍという厚膜において、高残膜率を維持しつつ良好な解像性を示したことから、優れたアルカリ現像性と厚膜解像性を有することが判る。ここで，アスペクト比（厚み／解像度）は、最大１．９に達し、高アスペクト比を有することが分かる。一方、成分（Ａ）が本発明の共重合体ではない比較例１−１〜１−３および１−７は、電気めっき工程中の密着状態が劣り、比較例１−４〜１−６は、アルカリ現像性を有しないものであった。
表３によれば、本発明の回路基板形成用アルカリ現像型液状フォトレジスト組成物：実施例２−１〜２−３は、無電解銅めっき工程中で、良好な形状保持性を示し、良好な無電解銅めっき層が得られた。また、クロスカット試験（ＪＩＳＫ５４００）においても良好な結果を示し、無電解めっきレジストとして優れていることが判る。一方、成分（Ａ）が本発明の共重合体ではない比較例２−１〜２−４においては、無電解工程中にレジストが剥離し、正常な銅の配線パターンを得ることができず、また、クロスカット試験においても劣るものであった。さらに、表３によれば、本発明の回路基板形成用アルカリ現像型液状フォトレジスト組成物：実施例２−１〜２−３は、優れた表面絶縁抵抗性と半田耐熱性を有しており、層間絶縁膜、回路保護膜としても使用可能であることが判る。
【００５７】
【発明の効果】
本発明に係わる回路基板形成用アルカリ現像型液状フォトレジスト組成物は、不飽和カルボン酸と、エポキシ基を有するラジカル重合性化合物、および共役ジオレフィン系不飽和化合物を含有する他のラジカル重合性化合物との共重合体を含有することを特徴とするものであるが、該共重合体の不飽和カルボン酸量をコントロールすることによって、レジスト組成物に、優れたアルカリ現像性と厚膜解像性を付与することができる。また、レジストパターン形成後に、レジストパターン中に存在する該共重合体を熱架橋せしめ、また、その熱架橋度合いをコントロールすることによって、用途に応じた、耐めっき液性などの耐薬品性、密着性、耐半田性を持たせることができる。こうした組成物は、回路基板形成における電気めっき用、無電解めっき用、などのめっき用レジスト、さらには、層間絶縁膜、回路保護膜として好適に用いることができる。特に、高アスペクトパターニングを要求される用途に好適である。また、本発明の組成物は、半田レジスト、エッチングレジストとしても用いることができる。[0001]
[Industrial application fields]
The present invention relates to a photoresist composition, and more particularly, a circuit used for bump formation, wiring formation, interlayer insulation layer, and circuit protection film that is performed when a circuit board is manufactured and a semiconductor or electronic component is mounted on the circuit board. More particularly, the present invention relates to an alkali development type liquid photoresist composition for forming a circuit board for high aspect patterning which is required in the production of a high density wiring board.
[0002]
[Prior art]
As a method for forming a circuit such as a printed wiring board, a method using electroplating or electroless plating is known. Electroplating is used for wiring formation, electrode formation, and formation of joints with the outside called bumps, and a plating electrode film is formed on a substrate in advance to form a plating layer.Other than partIs covered with a resist, electroplating is then performed on the exposed portion of the electrode, and then the resist is removed and etched to form a predetermined circuit. Electroless plating is a subtractorTibLaw, Semi-AditeIUsed in circuit formation methods called the full and additive methods, circuits on both sides of the substrate, and through-hole conductionPlatingUsed for the formation of
For these applications, plating resistance, chemical resistance, adhesion, high resolution during thick film formation, and the like are required. In addition, in the case of a full additive method or when a circuit is formed on a single-sided substrate and laminated to form a multilayer, various characteristics as a permanent resist are also required. Also,Along with the recent trend toward high-density wiring,Wiring width and,While the bump area is reduced,Their thickness tends to increase,Therefore, a high aspect patterning property is required.
[0003]
Conventionally, solvent-developable dry film photoresists have been used as resists for etching, plating, and insulation formation in the fields of circuit board manufacture, semiconductor and electronic component mounting on circuit boards, and the like. However, since a large amount of solvent is required for development, it has a drawback that it is difficult to use from the viewpoint of safety and health such as air pollution. Therefore, dry film photoresists that do not use organic solvents and alkali-development type liquid photoresists have been developed. However, dry film photoresists are prone to air bubbles during thermocompression bonding, and have good adhesion and heat resistance. However, it is difficult to use.
So far, various alkali development type liquid photoresists have been disclosed, and those using copolymers of methacrylic acid and alkyl methacrylate (Japanese Patent Publication No. 54-34327), of unsaturated carboxylic acid and alkyl group are disclosed. Using a copolymer having a glass transition point of 80 ° C. or more with a methacrylic acid alkyl ester having 4 or more carbon atoms (Japanese Patent Publication No. 58-12777),Carboxyl group-containing unsaturatedUsing a copolymer of a monomer and a styrene type monomer or a non-acidic vinyl compound (Japanese Patent Publication No. 55-38961), α, β-unsaturated carboxylic acidacid15 to 40 wt% and (meth) acrylic acid alkyl ester 15 to 45 wt%AndAnd a copolymer using 40 to 60% by weight of a styrene monomer (Japanese Patent Publication No. 54-25957) is known.
[0004]
[Problems to be solved by the invention]
However, in any case, it cannot be said that alkali developability, thick film resolution, plating resistance, chemical resistance, adhesion, and heat resistance are sufficient. In order to solve these problems, attempts have been made to achieve both alkali developability and various characteristics by coexisting an epoxy group and a carboxylic acid group in a resist composition and thermally cross-linking both groups after pattern formation.
However, these compositions may be a mixture of a compound containing an epoxy group and a compound containing a carboxylic acid (Japanese Patent Laid-Open No. 62-187722) or a modified compound by a polymer reaction (Japanese Patent Laid-Open No. 64-64). 62375). The disadvantages of these conventional compositions are that when they are a mixture, they have problems to be solved such as compatibility of the two kinds of compounds, storage stability of the composition, and rough coating. When it is a compound, there is a problem to be solved in the reproducibility due to complicated synthesis and difficulty in quantifying the reaction.
The present invention provides an alkali for circuit board formation having excellent alkali developability and thick film resolution, and having excellent plating resistance, chemical resistance, solder heat resistance, adhesion, and insulation in the exposed area. The object is to provide a developable liquid photoresist composition.
[0005]
[Means for Solving the Problems]
In view of the actual situation, the present inventors have reached the present invention as a result of intensive studies in consideration of the above-mentioned problems.
The greatest feature of the composition of the present invention is that the copolymer soluble in the alkaline aqueous solution as the base polymer has a carboxylic acid group and an epoxy group in the same molecule.
That is, the present invention
(A) (a) Unsaturated carboxylic acidThe copolymerization ratio of 5 to 50% by weight(B) Radical polymerizable compound having an epoxy groupThe copolymerization ratio of 5-70% by weight,and(C) Other radically polymerizable compoundsThe copolymer has a copolymerization ratio of 10 to 70% by weight, and the component (c) contains a conjugated diolefin unsaturated compound having a copolymerization ratio of 1 to 30% by weight.Copolymer,
(B) A polymerizable compound having at least one ethylenically unsaturated double bond, And
(C) a photopolymerization initiator,
An alkali development type liquid photoresist composition for forming a circuit board, comprising:
About.
[0006]
Hereinafter, the components of the composition of the present invention will be described.
1. Component (A) (hereinafter referred to as “copolymer I”):
The copolymer I used in the present invention is a copolymer that is soluble in an alkaline aqueous solution and can be crosslinked by heating. Copolymer I comprises (a) an unsaturated carboxylic acid and (b) a radical polymerizable compound having an epoxy group, (c)Contains conjugated diolefinically unsaturated compoundsIt can be obtained by radical copolymerization with other radical polymerizable compounds in a solvent.
Preferred examples of the unsaturated carboxylic acid include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; and dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid.
The copolymerization ratio of the unsaturated carboxylic acid in the copolymer I is preferably 5 to 50% by weight, particularly preferably 10 to 40% by weight. If it is less than 5% by weight, the obtained copolymer is hardly dissolved in an alkaline aqueous solution, so that a film residue is liable to occur after development, and it is difficult to obtain sufficient resolution. On the other hand, if it exceeds 50% by weight, the solubility of the obtained copolymer in an alkaline aqueous solution becomes too high, and dissolution of the exposed portion, that is, film slipping easily occurs.
[0007]
Examples of the radical polymerizable compound having an epoxy group include glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, acrylic acid-3, 4-epoxybutyl, methacrylic acid-3,4-epoxybutyl, acrylic acid-6,7-epoxyheptyl, methacrylic acid-6,7-epoxyheptyl, α-ethylacrylic acid-6,7-epoxyheptyl, etc. be able to. The copolymerization ratio of the radically polymerizable compound having an epoxy group in the copolymer I is preferably 5 to 70% by weight, particularly preferably 10 to 50% by weight. If it is less than 5% by weight, the heat resistance of the pattern obtained from the composition will not be sufficient.TheOn the other hand, when it exceeds 70% by weight, a problem is likely to occur in the storage stability of the copolymer.
[0008]
Next, other radically polymerizable compounds will be described.
Usually, when radical polymerization is carried out in a two-component system consisting of an unsaturated carboxylic acid and a radically polymerizable compound having an epoxy group, the epoxy group reacts with the carboxylic acid group during the polymerization reaction, resulting in crosslinking and gelation of the polymerization system. There is a problem to do. Therefore, in order to obtain the copolymer I, it is necessary to copolymerize another radical polymerizable compound as the third component to suppress the reaction between the epoxy group and the carboxylic acid group.
As the other radical polymerizable compound having such a purpose, a monoolefin unsaturated compound is preferable. In addition, by copolymerizing a monoolefin unsaturated compound, the mechanical properties of the copolymer can be appropriately controlled, and the solubility in an alkaline aqueous solution can be adjusted.
Examples of the monoolefin unsaturated compound include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, and t-butyl methacrylate; alkyl alkyl esters such as methyl acrylate and isopropyl acrylate; Methacrylic acid cyclic alkyl esters such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, dicyclopentanyloxyethyl methacrylate, isobornyl methacrylate; cyclohexyl acrylate, 2-methylcyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentanyloxyethyl Acrylic acid cyclic alkyl esters such as acrylate and isobornyl acrylate; E alkenyl methacrylate, methacrylic acid aryl esters such as benzyl methacrylate; phenyl acrylate, acrylic acid aryl esters such as benzyl acrylate; diethyl maleate, diethyl fumarate, diethyl itaconateUnsaturatedDicarboxylic acid diesters; hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate; styrene, α-methylstyrene, m-methylsterene, p-methylstyrene, p-methoxystyrene, acrylonitrile, methacrylonitrile, Vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate and the like can be used.
A plurality of these other radically polymerizable compounds can be used. For example, although the copolymer I exhibits sufficient heat resistance by thermal crosslinking, it can be further improved by using an aromatic radical polymerizable compound such as styrene as a part of other radical polymerizable compounds. Can be improved.
The copolymerization ratio of the other radically polymerizable compound in the copolymer I is preferably 10 to 70% by weight, particularly preferably 20 to 60% by weight. If it is less than 10% by weight, gelation tends to occur during the polymerization reaction, and if it exceeds 70% by weight, the solubility of the copolymer in the aqueous alkali solution is reduced, and the heat resistance of the pattern obtained from the composition is reduced. It may be insufficient.
Also,By replacing some of them with conjugated diolefin unsaturated compounds,Improves the adhesive shrinkage of the light-irradiated part and the adhesion of the patterned coating film to the substratebe able to.
As such a conjugated diolefin unsaturated compound, for example, 1,3-butadiene, isoprene, 2,3-dimethylbutadiene and the like can be used.
The copolymerization ratio of the conjugated diolefin unsaturated compound in the copolymer I is 1 to 30% by weight, particularly preferably 3 to 15% by weight. If it is less than 1% by weight, it does not contribute to improving the adhesion of the obtained pattern. If it exceeds 30% by weight, the solubility of the copolymer in the aqueous alkali solution is reduced, or the pattern obtained from the composition May have insufficient heat resistance.
[0009]
Thus, preferred structural units of the copolymer I include the following formulas (1), (2), (3), (4) and (5).
[0010]
[Chemical 1]

[0011]
[Chemical 2]

[0012]
[Chemical 3]

[0013]
[Formula 4]

[0014]
[Chemical formula 5]

[0015]
Examples of the polymerization solvent used in polymerizing the copolymer I include alcohols such as methanol and ethanol; cyclic ethers such as tetrahydrofuran and dioxane; cellosolv esters such as methyl cellosolve acetate; ethylene glycol monomethyl ether and ethylene glycol. Alkyl ethers of polyhydric alcohols such as monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; aromatic hydrocarbons such as toluene and xylene; acetone, methyl ethyl ketone, methyl isobutyl Ketones such as ketones; ethyl acetate, butyl acetate, propylene glycol methyl Esters such as chromatography ether acetate. Of these, cyclic ethers, polyhydric alcohol alkyl ethers, and esters are preferred.
As a polymerization catalyst in radical polymerization, a normal radical polymerization initiator can be used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2 Azo compounds such as' -azobis- (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1'-bis- (t-butylperoxy) cyclohexane, etc. And organic peroxides and hydrogen peroxide. When a peroxide is used as a radical polymerization initiator, a redox initiator may be combined with a reducing agent.
[0016]
The molecular weight of the copolymer I and its distribution are not particularly limited as long as the solution of the composition of the present invention can be uniformly applied.
2.Component (B) (hereinafter referred to as “ethylenic compound”):
Used in the present inventionEthylenic compoundPreferred examples include monofunctional or polyfunctional esters of acrylic acid or methacrylic acid.
[0017]
As monofunctional (meth) acrylates, commercially available products such as Aronix M-101, M-111, M-114 (manufactured by Toa Gosei Chemical Co., Ltd.), KAYARAD TC-110S, TC-120S (Japan) Kayaku Co., Ltd.), V-158, V-2311 (Osaka Organic Chemical Co., Ltd.) and the like.
As the bifunctional (meth) acrylate, commercially available products such as Aronix M-210, M-240, M-6200 (manufactured by Toa Gosei Chemical Industry Co., Ltd.), KAYARAD HDDA, HX-220, R- 604 (manufactured by Nippon Kayaku Co., Ltd.), V260, V312 and V335HP (manufactured by Osaka Organic Chemical Industry Co., Ltd.).
Moreover, as trifunctional or more than (meth) acrylate, as a commercial item, for example, Aronix M-309, M-400, M-405, M-450, M-7100, M-8030, M -8060 (manufactured by Toa Synthetic Chemical Industry Co., Ltd.), KAYARAD TMPTA, DPCA-20, -30, -60, -120 (manufactured by Nippon Kayaku Co., Ltd.), V-295, -300, -360, -GPT, -3PA, -400 (Osaka Organic Chemical Co., Ltd.) etc. can be mentioned.
These compounds may be used alone or in combination of two or more, and are preferably 30 to 200 parts by weight, more preferably 50 to 150 parts by weight with respect to 100 parts by weight of the copolymer I. If it is less than 30 parts by weight, the sensitivity tends to decrease, and if it exceeds 200 parts by weight,The compatibility with the copolymer I may deteriorate, and film roughness may occur on the surface of the coating film after forming the coating film.
[0018]
3.Ingredient (C):
Examples of the photopolymerization initiator used in the present invention include a photoradical polymerization initiator capable of reacting an ethylenic compound, or a photocationic polymerization initiator capable of reacting an epoxy group in the copolymer I. Can be used. Examples of photo radical polymerization initiators include α-diketones such as benzyl and diacetyl; acyloins such as benzoin; acyloin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; thioxanthone and 2,4-diethyl Thioxanthone, thioxanthone-4-sulfonic acid;Benzophenones such as benzophenone, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone; acetophenone, p-dimethylaminoacetophenone, α, α′-dimethoxyacetoxybenzophenone, 2,2 ′ -Dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl−[4- (Methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-diMeAcetophenones such as tilamino-1- (4-morpholinophenyl) -butan-1-one; quinones such as anthraquinone and 1,4-naphthoquinone; phenacyl chloride, tribromomethylphenylsulfone, tris (trichloromethyl)- Halogen compounds such as s-triazine; peroxides such as di-t-butyl peroxide; and acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
[0019]
Among the various photopolymerization initiators described above, preferred compounds include 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propylene as a photoradical polymerization initiator.NoAcetophenones such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one or phenacyl chloride, tribromomethylphenylsulfone, 2,4,6-trimethylbenzoyldiphenyl Mention may be made of halogen compounds such as phosphine oxide and tris (trichloromethyl) -s-triazine.
Moreover, as a photocationic polymerization initiator,,Commercial products as shown below can be used. Adeka Ultra Set PP-33 (Asahi Denka Kogyo Co., Ltd.) which is a diazonium salt, OPTOMER SP-150, 170 which is a sulfonium salt
(Asahi Denka Kogyo Co., Ltd.), IRGACURE261 (CIBA-GEIGY), which is a metallocene compound, and the like.
The amount of the photopolymerization initiator used is preferably 1.0 to 50 parts by weight, particularly preferably 5 to 30 parts by weight, based on 100 parts by weight of the copolymer I. If it is less than 1 part by weight, radical deactivation (decrease in sensitivity) due to oxygen tends to occur,AlsoIf it exceeds 50 parts by weight,Compatibility may deteriorate, or storage stability may decrease.
From the viewpoint of storage stability,The radical photopolymerization initiator is more preferable than the cationic polymerization initiator. further,These radical photopolymerization initiators and cationic photopolymerization initiators or photosensitizers can be used in combination.
[0020]
4). Organic solvent:
An organic solvent can be added to the composition of the present invention for the purpose of uniformly mixing the above-described components. As the solvent to be used, a solvent that can uniformly dissolve the copolymer I, the ethylenic compound, the photopolymerization initiator, and the epoxy compound and does not react with each component is used. Examples of such solvents include alcohols such as methanol and ethanol; cyclic ethers such as tetrahydrofuran; glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol alkyl ethers such as methyl cellosolve acetate and ethyl cellosolve acetate. Acetates; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol dimethyl ether; propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate and propylene glycol propyl ether acetate; aromatic hydrocarbons such as toluene and xylene; Methyl ethyl ketone Ketones such as hexanone, 4-hydroxy-4-methyl-2-pentanone; ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate , Ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl acetate, butyl acetate, etc. Esters can be used.
[0021]
Further, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone , Isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate, etc. A high boiling point solvent can also be added.
Among these solvents, glycol ethers such as ethylene glycol monoethyl ether; ethylene glycol alkyl ether acetates such as ethyl cellosolve acetate because of solubility, reactivity with each component, and ease of film formation; Esters such as ethyl 2-hydroxypropionate; diethylene glycols such as diethylene glycol monomethyl ether are preferred.
The amount of the solvent used is not particularly limited as long as it can be adjusted according to the application and application method, and the composition can be mixed uniformly, but it is 50% by weight or less based on the resulting composition. , Preferably 10 to 40% by weight.
[0022]
5. Other additives:
In the present invention, an epoxy compound can be blended for the purpose of further improving the heat resistance and hardness of the pattern. Such an epoxy compound is not limited as long as the compatibility is not affected, but is preferably a bisphenol A type epoxy resin, a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a cyclic aliphatic epoxy resin, In addition to glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, heterocyclic epoxy resins, glycidyl methacrylate-containing resin compositions such as Optomer SS (manufactured by Nippon Synthetic Rubber Co., Ltd.) can be mentioned. Among these, bisphenol A type epoxy resin, cresol novolac type epoxy resin, glycidyl ester type epoxy resin and the like are particularly preferable. The amount of these epoxy compounds used is preferably 100 parts by weight or less, more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the copolymer I.
[0023]
In the composition of this invention, surfactant can also be mix | blended in order to improve applicability | paintability, defoaming property, and leveling property. Examples of the surfactant include BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (manufactured by Dainippon Ink and Chemicals), Florard FC-135, FC-170C, FC-430, FC-431 (manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145 (Asahi Glass ( Co., Ltd.), SH-28PA, -190, -193, SZ-6032, SF-8428 (manufactured by Toray Silicone Co., Ltd.), etc. it can. The amount of these surfactants to be used is preferably 5 parts by weight or less, more preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the copolymer I.
[0024]
An adhesion assistant can also be used to improve the adhesion to the substrate. A functional silane coupling agent is effective as the adhesion aid to be used. Here, the functional silane coupling agent means a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group. Specific examples include trimethoxysilylbenzoic acid, γ -Methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanateNeAnd m-propyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.
These adhesion assistants can be used alone or in combination of two or more. The blending amount is preferably 20 parts by weight or less, more preferably 0.05 to 10 parts by weight per 100 parts by weight of the copolymer I.
[0025]
Furthermore, a filler, a coloring agent, a viscosity modifier, etc. can be added to the composition of this invention as needed.
fillingMaterialExamples thereof include silica, alumina, talc, bentonite, zirconium silicate, and powdered glass.
As colorants, extender pigments such as alumina white, clay, barium carbonate, barium sulfate;Inorganic pigments such as zinc white, ultramarine, bitumen, titanium oxide, zinc chromate, bengara, carbon black;Organic pigments such as Brilliant Carmine 6B, Permanent Red 6B, Permanent Red R, Phthalocyanine Blue, Phthalocyanine Green;Basic dyes such as magenta and rhodamine;Direct dyes such as direct scarlet and direct orange;Examples include acid dyes such as roserine and methanyl yellow.
Examples of the viscosity modifier include bentonite, silica gel, and aluminum powder.
These additives are within a range not impairing the essential characteristics of the composition, and preferably 50% by weight or less based on the obtained composition.
[0026]
BookInventionThe preparation of the composition comprises fillers,ColorantIf not added, just mixing and stirring in the usual way,ColorantWhen adding,What is necessary is just to disperse | distribute and mix using dispersers, such as a dissolver, a homogenizer, and a 3 roll mill. Moreover, you may filter using a mesh, a membrane filter, etc. as needed.
[0027]
next,The method for using the composition of the present invention will be described.
1. Method for forming the coating film:
In the present invention, the above-described composition solution is applied onto a predetermined substrate to be processed,PrebakedA desired coating film can be formed by removing the solvent. The coating method on the substrate to be processed is not particularly limited, and methods such as a spin coating method, a roll coating method, a screen printing method, and an applicator method can be employed.
In addition, although the drying conditions of the coating film of the composition of this invention differ with kinds of a composition, a mixture ratio, a coating film thickness, etc., it is about 70 minutes at about 70-90 degreeC for about 5 to 20 minutes. If the drying time is too short, the adhesion state during development is deteriorated, and if it is too long, the resolution is lowered due to hot fog.
[0028]
2. Exposure method:
By irradiating the obtained coating film with ultraviolet rays or visible light of 200 to 500 nm through a mask having a predetermined pattern, only a necessary portion can be photocured.
As a source of these actinic rays, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. X-rays, electron beams and the like can also be used as active energy rays for curing the composition.
The amount of exposure varies depending on the type of each component of the composition, the amount blended, and the dry film thickness.1,000-5,000 J / m ²  (UV42 manufactured by Oak Co., Ltd.).
[0029]
3. Development method:
As a developing method in the present invention, an alkaline aqueous solution is used as a developing solution, an unnecessary portion is dissolved and removed, and only an exposed portion is left to form a pattern.
Examples of the developer in the present invention include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl. Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4].3.[0] An aqueous solution of an alkali such as 5-nonane can be used.
Also,An aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution can also be used as a developer.
The development time varies depending on the type of each component of the composition, the blending ratio, and the dry film thickness of the composition, but is usually 30 to 180 seconds. The development method is a liquid piling method, dipping method, paddle method, spray development. Any of law etc. may be used.
After the development, washing with running water is performed for 30 to 90 seconds, and the desired pattern can be obtained by air drying using an air gun or the like or drying in an oven.
[0030]
4). Post-processing:
The composition of the present invention isRecordActinic ray orActivityAlthough it can be cured sufficiently only by irradiation with energy rays, exposure (hereinafter referred to as “the following”) depends on the application."Post-exposure". ) Can be heat cured,It is particularly preferred when used as a permanent film.
The post-exposure can be performed by the same method as the above-described exposure method, and the exposure amount is not particularly limited, but when using a high-pressure mercury lamp1,000 to 10,000 J / m ² (UV42 manufactured by Oak Co., Ltd.) is preferable.
The heat curing method is performed using a heating device such as a hot plate or oven at a predetermined temperature, for example, 120 to 200 ° C. for a predetermined time, for example, 10 to 60 minutes on the hot plate, or 30 to 90 minutes in the oven. What is necessary is just to heat-process. In this way, a cured product with even better characteristics can be obtained.
The
[0031]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”.
(1) Synthesis of copolymer I
Copolymers 1-8 were synthesized as examples of copolymer I, and copolymers 9-14 were synthesized as comparative examples. Details are described below.
[0032]
Synthesis of copolymer 1
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 510.0 g of diethylene glycol dimethyl ether as a solvent were added, and the polymerization initiator was dissolved. Stir until Subsequently, 42.5 g of methacrylic acid, 100.0 g of glycidyl methacrylate, 95.0 g of dicyclopentanyl methacrylate and 12.5 g of butadiene were charged, and then gently stirring was started. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0033]
Synthesis of copolymer 2
The flask equipped with a dry ice / methanol reflux was purged with nitrogen, and then charged with 10.0 g of 2,2′-azobis-2,4-dimethylvaleronitrile as a polymerization initiator and 510.0 g of dioxane as a solvent, and a polymerization initiator. Stir until dissolved. Subsequently, 45.05 g of crotonic acid, 101.35 g of methacrylic acid-6,7-epoxyheptyl, 63.08 g of isobornyl methacrylate, 22.53 g of styrene, and 18.03 g of isoprene were charged, and stirring was started gently. . Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0034]
Synthesis of copolymer 3
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of benzoyl peroxide as a polymerization initiator and 510.0 g of diethylene glycol monomethyl ether as a solvent are charged and stirred until the polymerization initiator is dissolved. Subsequently, 51.88 g of itaconic acid, 82.55 g of α-ethylacrylic acid-6,7-epoxyheptyl, 89.63 g of benzyl methacrylate, 11.8 g of α-methylstyrene and 14.16 g of butadiene were gently added. Stirring started. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0035]
Synthesis of copolymer 4
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 510.0 g of diethylene glycol dimethyl ether as a solvent were added, and the polymerization initiator was dissolved. Stir until Subsequently, 63.68 g of methacrylic acid, 47.62 g of methacrylic acid-6,7-epoxyheptyl, 114.28 g of sec-butyl methacrylate, 11.9 g of styrene and 11.9 g of isoprene were charged, and then gently stirring was started. . Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0036]
Synthesis of copolymer 5
The flask equipped with a dry ice / methanol reflux was purged with nitrogen, and then charged with 10.0 g of 2,2′-azobis-2,4-dimethylvaleronitrile as a polymerization initiator and 510.0 g of dioxane as a solvent, and a polymerization initiator. Stir until dissolved. Subsequently, 67.5 g of crotonic acid, 50.0 g of α-ethylacrylic acid-6,7-epoxyheptyl, 105.0 g of diethyl maleate, 25.0 g of α-methylstyrene, and 2.5 g of butadiene were slowly added. Stirring was started. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0037]
Synthesis of copolymer 6
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of benzoyl peroxide as a polymerization initiator and 510.0 g of diethylene glycol monoethyl ether as a solvent are charged and stirred until the polymerization initiator is dissolved. Subsequently, after it was charged with 64.28 g of itaconic acid, 95.25 g of glycidyl methacrylate, 30.95 g of methyl methacrylate, 47.63 g of styrene and 11.90 g of isoprene, the stirring was started gently. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0038]
Synthesis of copolymer 7
After substituting the flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 510.0 g of diethylene glycol dimethyl ether as a solvent were dissolved, and the polymerization initiator was dissolved. Stir until Subsequently, 67.5 g of methacrylic acid, 50.0 g of glycidyl methacrylate, 80.0 g of dicyclopentanyl methacrylate, 50.0 g of styrene and 2.5 g of butadiene were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0040]
Synthesis of copolymer 9
After substituting the flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 510.0 g of diethylene glycol dimethyl ether as a solvent were dissolved, and the polymerization initiator was dissolved. Stir until Subsequently, after it was charged with 85.45 g of itaconic acid, 101.28 g of dicyclopentanyl methacrylate, and 63.3 g of styrene, stirring was started gently. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0041]
Synthesis of copolymer 10
The flask equipped with a dry ice / methanol reflux was purged with nitrogen, and then charged with 10.0 g of 2,2′-azobis-2,4-dimethylvaleronitrile as a polymerization initiator and 510.0 g of diethylene glycol monomethyl ether as a solvent for polymerization. Stir until the initiator is dissolved. Subsequently, 71.05 g of crotonic acid, 113.15 g of isobornyl methacrylate, 52.63 g of α-methylstyrene, and 13.15 g of butadiene were charged, and stirring was started gently. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0042]
Synthesis of copolymer 11
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of benzoyl peroxide as a polymerization initiator and 510.0 g of dioxane as a solvent are stirred and stirred until the polymerization initiator is dissolved. Subsequently, 75.75 g of methacrylic acid, 143.95 g of sec-butyl methacrylate, and 30.0 g of butadiene were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0043]
Synthesis of copolymer 12
After substituting the flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 510.0 g of diethylene glycol dimethyl ether as a solvent were dissolved, and the polymerization initiator was dissolved. Stir until Subsequently, 69.45 g of glycidyl methacrylate, 111.1 g of diethyl maleate, and 69.45 g of styrene were charged, and then gently stirring was started. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0044]
Synthesis of copolymer 13
The flask equipped with a dry ice / methanol reflux was purged with nitrogen, and then charged with 10.0 g of 2,2′-azobis-2,4-dimethylvaleronitrile as a polymerization initiator and 510.0 g of ethyl cercerobacetate as a solvent, Stir until the polymerization initiator is dissolved. Subsequently, after 34.25 g of α-ethylacrylic acid-6,7-epoxyheptyl, 145.25 g of benzyl methacrylate and 68.5 g of α-methylstyrene were charged, the stirring was started gently. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0045]
Synthesis of copolymer 14
After substituting a flask equipped with a dry ice / methanol reflux with nitrogen, 10.0 g of benzoyl peroxide as a polymerization initiator and 510.0 g of propylene glycol methyl ether acetate as a solvent are stirred and stirred until the polymerization initiator is dissolved. Subsequently, after it was charged with 64.93 g of itaconic acid, 103.9 g of acrylonitrile, 64.93 g of styrene and 16.23 g of isoprene, stirring was started gently. Thereafter, the temperature of the solution was raised to 80 ° C., and this temperature was maintained for 5 hours, and then heated at 90 ° C. for 1 hour to complete the polymerization. Thereafter, the reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was performed three times in total, the obtained coagulated product was vacuum-dried at 60 ° C. for 48 hours to obtain the desired copolymer.
[0046]
(2) Preparation of alkaline development type liquid photoresist composition for circuit board formation
Component (A), component (B), component (C), solvent and other additives were blended as shown in Table 1 to obtain the composition. In Table 1, 1 to 5 of component (A)7Is a copolymer of the present invention, and 9 to 15 are not copolymers of the present invention. The component (A) 15 is a bisphenol A type epoxy acrylate which has been conventionally used in an alkali development type photoresist composition. Of the prepared compositions, those that do not contain fillers and colorants are mixed and stirred with a Henschel mixer, and those that contain fillers and colorants are mixed with ingredients other than fillers and colorants. After mixing and stirring with a mixer, a filler and a colorant were subsequently added thereto, and after mixing and stirring again, the mixture was kneaded with a three-roll mill.
[0047]
(3) Evaluation of various characteristics
(1) Evaluation of thick film resolution
Among the compositions in Table 2, compositions 1 to 1 that do not contain fillers and colorants9This was done for 15-20 and 24.
Si O₂The composition was applied onto a glass substrate using a spinner and then pre-baked on a hot plate at 80 ° C. for 10 minutes to form a coating film having a thickness of 30 μm. Next, through a negative mask (TOPPAN-TEST-CHART-N) for resolution measurement, using a high-pressure mercury lamp (ML-3 manufactured by Mikasa Electric), 3000 J / m²(Oak Manufacturing UV-42) exposed. This was developed in a 0.5% aqueous tetramethylammonium hydroxide solution. Thereafter, it was washed with running water and blown with nitrogen to obtain a residual pattern. This was observed with an optical microscope and the resolution was measured. The film thickness after development was measured (α step 100 manufactured by HERZ), and the remaining film ratio (%) was determined. Here, the remaining film ratio is a value obtained by dividing the film thickness after development by the film thickness after pre-baking and multiplying by 100. The results are shown in Table 2.
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(2) Performance evaluation as a resist for electroplating
In order to evaluate the performance as a resist for electroplating, the resistance of the resist pattern to the electroplating solution was examined. In addition, bumps were actually formed by electroplating, and the state of the formed bumps was examined.
First, the electroplating solution resistance of the resist pattern will be described. Of the compositions in Table 1, Compositions 1 to 1915 to 20 and 24, a resist pattern having a film thickness of 30 μm was obtained on a stainless steel (SUS304) substrate by the same method as in (1), and then cured by heating on a hot plate at 150 ° C. for 30 minutes. did. After immersing the test specimen in a stirring solution of each of a gold plating solution, a nickel plating solution, and a copper plating solution at 60 ° C. for 60 minutes, this was taken out, washed with running water and dried to obtain a test specimen. . The test specimen was observed with a scanning electron microscope, the state of the resist pattern was observed, and the electroplating solution resistance was evaluated.
Next, using a separately prepared stainless steel substrate, a test specimen was obtained under the same method and conditions as described above, except that a mask having a 50 μm × 50 μm square drawn as a shadow portion was used for exposure, and bump formation was performed using this. The test was conducted. A concave shape of 50 μm × 50 μm is formed in the resist pattern of the test specimen. Using each plating solution, electroplating was performed at 60 ° C. for 40 to 60 minutes. Next, in order to peel the resist from the electroplated test body, the test body was immersed in a stirring solution of a stripping solution at 50 ° C. for 60 minutes to strip the resist. After peeling off the resist, 50 μm × 50 μm bumps formed on the substrate were observed with a scanning electron microscope.
The specifications of each plating solution and stripping solution are shown below, and the results are shown in Table 2.
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[Table 1]

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[Table 2]

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(Specifications of electrolytic gold plating solution)
Sodium citrate: 100 g / L
KAu (CN)₂        : 8g / L
Nickel sulfamate: 3g / L
Zinc acetate 0.5g / L
Water: 1 overallL (liter)Amount to be
pH: 4.5
Current density: 2.0 A / dm²
(Specifications of electrolytic nickel plating solution)
Nickel chloride: 100 g / L
Boric acid: 8g / L
Nickel sulfamate: 600 g / L
Water: 1 overallL (liter)Amount to be
pH: 4.0
Current density: 3.0 A / dm²
(Specifications of electrolytic copper plating solution)
Copper sulfate: 210 g / L
Sulfuric acid: 52 g / L
Water: 1 overallL (liter)Amount to be
pH: 1.0
Current density: 3.0 A / dm²
(Composition of stripping solution)
Phenol: 25 parts
Dimethyl sulfoxide: 20 parts
Orthodichlorobenzene: 55 parts
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(3) Performance evaluation as a resist for electroless plating
In order to evaluate the performance as a resist for electroless plating, electroless copper plating is actually performed, the state of the formed copper wiring pattern, after platingofThe state of the resist pattern was examined. Details will be described below.
Using a 305-mesh polyester screen, the compositions 11-13, 21-23 and 25 of the compositions in Table 2 were screen-printed and applied to the glass epoxy substrate subjected to the activation treatment. Pre-baking on a hot plate for 5 minutes gave a coating film with a thickness of 35 μm. Next, a resist pattern was obtained by the same method and conditions as in (1) except that a mask having a comb-shaped electrode pattern drawn as a shaded part in accordance with JIS-Z-3197 (Type 2) was used for exposure. Then 10,000 J / m²Post-exposure was performed, and further, thermosetting at 150 ° C. for 2 hours was performed to obtain a test specimen. The test specimen was immersed in an electroless copper plating solution at 60 ° C. for 24 hours to form an electroless copper plating on the comb electrode. This test body corresponds to a printed circuit board by a full additive method. The shape of the formed copper wiring pattern and the deterioration state of the resist pattern were observed with a stereomicroscope. Moreover, about the test body after an electroless copper plating process, the crosscut test was done except the part in which the pattern was formed, and it was set as adhesive evaluation.
The plating solution specifications are shown below, and the results are shown in Table 3.
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[Table 3]

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(Specifications of electroless copper plating solution)
Copper sulfate: 10 g / L
Ethylenediaminetetraacetic acid: 30 g / L
35% formalin: 4ml / L
Polyethylene glycol (molecular weight 400): 3 g / L
Dipyridyl: 40 mg / L
Sodium hydroxide :pAmount to become H13
Water: 1 overallL (liter)Amount to be
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(4) Performance evaluation as interlayer insulation film and circuit protection film
Next, in order to evaluate the performance as an interlayer insulating film and a circuit protective film, the surface insulation resistance of the resist layer and the solder heat resistance of the resist pattern were examined. First, using the fully additive substrate made of the resist pattern and electroless plating prepared in (3) as a test specimen, the initial surface insulation resistance value and moisture absorption at 40 ° C., 90%, 96 hours under the condition of application at 100 V for 1 minute. The surface insulation resistance value after the treatment was measured (based on JIS Z3197). Regarding solder heat resistance, a 35 μm resist coating film was obtained on a glass epoxy substrate by the same method and conditions as in (3) for the same composition used for the measurement of the surface insulation resistance value. A resist pattern was obtained by the same method and conditions as in (3) except that the mask used in (2) was used, and further a resist pattern was post-treated by the method of (3) to obtain a test specimen.
The test specimen was immersed in a 260 ° C. solder bath composed of 60% tin and 40% lead for 10 seconds and then returned to room temperature four times, and then the damage of the resist pattern was examined with a scanning electron microscope. Table 3 shows the results.
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According to Table 2, the alkaline development type liquid photoresist composition for circuit board formation of the present invention: Examples 1-1 to 1-9In the electroplating process, excellent shape retention was exhibited, and good bumps could be formed. In addition, in a thick film having a film thickness of 30 μm, good resolution was exhibited while maintaining a high residual film ratio, and thus it can be seen that the film has excellent alkali developability and thick film resolution. Here, the aspect ratio (thickness / resolution) is,Up to 1.9,It can be seen that it has a high aspect ratio. On the other hand, Comparative Examples 1-1 to 1-3 and 1-7, in which the component (A) is not a copolymer of the present invention, are inferior in the adhesion state during the electroplating process, and Comparative Examples 1-4 to 1-6 are , It did not have alkali developability.
According to Table 3, the alkali development type liquid photoresist composition for circuit board formation of the present invention: Examples 2-1 to 2-3In the electroless copper plating process, good shape retention was exhibited, and a good electroless copper plating layer was obtained. Moreover, a favorable result is shown also in the crosscut test (JISK5400), and it turns out that it is excellent as an electroless plating resist. On the other hand, in Comparative Examples 2-1 to 2-4 in which the component (A) is not the copolymer of the present invention, the resist peels off during the electroless process, and a normal copper wiring pattern cannot be obtained. Moreover, it was inferior also in the crosscut test. Furthermore, according to Table 3, the alkali development type liquid photoresist composition for circuit board formation of the present invention: Examples 2-1 to 2-3Has excellent surface insulation resistance and solder heat resistance, and can be used as an interlayer insulating film and a circuit protective film.
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【The invention's effect】
An alkaline development type liquid photoresist composition for circuit board formation according to the present invention comprises an unsaturated carboxylic acid, a radical polymerizable compound having an epoxy group, andContains conjugated diolefinically unsaturated compoundsIt is characterized by containing a copolymer with another radical polymerizable compound, but by controlling the amount of unsaturated carboxylic acid of the copolymer, the resist composition has excellent alkali developability. And thick film resolution can be imparted. In addition, after the resist pattern is formed, the copolymer present in the resist pattern is thermally crosslinked, and by controlling the degree of thermal crosslinking, chemical resistance such as plating solution resistance, adhesion And solder resistance can be provided. Such a composition can be suitably used as a plating resist for electroplating and electroless plating in forming a circuit board, and further as an interlayer insulating film and a circuit protective film. In particular,Suitable for applications requiring high aspect patterning. The composition of the present invention can also be used as a solder resist or an etching resist.

Claims (3)

(A) (a) copolymerization ratio of unsaturated carboxylic acid is 5 to 50% by weight , (b) copolymerization ratio of radical polymerizable compound having an epoxy group is 5 to 70% by weight , and (c) other radicals A copolymer having a copolymerization ratio of 10 to 70% by weight of a polymerizable compound , wherein the component (c) contains a conjugated diolefin unsaturated compound having a copolymerization ratio of 1 to 30% by weight. ,
(B) a polymerizable compound having at least one ethylenically unsaturated double bond , and (C) a photopolymerization initiator,
An alkali development type liquid photoresist composition for forming a circuit board, comprising: Component (C) is 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one , Phenacyl chloride, tribromomethylphenyl sulfone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, tris (trichloromethyl) -s-triazine and (1-6-η-cumene) (η-cyclopentadienyl) 2. The alkali developing liquid photoresist composition for forming a circuit board according to claim 1, which is selected from the group consisting of iron (+1) hexafluorophosphate (1-). In addition to the component (A), the component (B) and the component (C), it further contains an organic solvent selected from the group consisting of ethylene glycol monoethyl ether, ethyl cellosolve acetate, ethyl 2-hydroxypropionate and diethylene glycol monomethyl ether. Item 3. The alkali developing liquid photoresist composition for circuit board formation according to Item 1 or Item 2 .