JP3716469B2 - Photosensitive paste for pattern processing - Google Patents

Description

これらの屈折率を向上させるモノマーに、種々の感光性モノマーを混合して用いることもできる。
【００４１】
感光性モノマーとしては、炭素−炭素不飽和結合を含有する化合物で、その具体的な例として、メチルアクリレート、エチルアクリレート、ｎ−プロピルアクリレート、イソプロピルアクリレート、ｎ−ブチルアクリレート、ｓｅｃ−ブチルアクリレート、ｓｅｃ−ブチルアクリレート、イソ−ブチルアクリレート、ｔｅｒｔ−ブチルアクリレート、ｎ−ペンチルアクリレート、アリルアクリレート、ベンジルアクリレート、ブトキシエチルアクリレート、ブトキシトリエチレングリコールアクリレート、シクロヘキシルアクリレート、ジシクロペンタニルアクリレート、ジシクロペンテニルアクリレート、２−エチルヘキシルアクリレート、グリセロールアクリレート、グリシジルアクリレート、ヘプタデカフロロデシルアクリレート、２−ヒドロキシエチルアクリレート、イソボニルアクリレート、２−ヒドロキシプロピルアクリレート、イソデキシルアクリレート、イソオクチルアクリレート、ラウリルアクリレート、２−メトキシエチルアクリレート、メトキシエチレングリコールアクリレート、メトキシジエチレングリコールアクリレート、オクタフロロペンチルアクリレート、フェノキシエチルアクリレート、ステアリルアクリレート、トリフロロエチルアクリレート、アリル化シクロヘキシルジアクリレート、１，４−ブタンジオールジアクリレート、１，３−ブチレングリコールジアクリレート、エチレングリコールジアクリレート、ジエチレングリコールジアクリレート、トリエチレングリコールジアクリレート、ポリエチレングリコールジアクリレート、ジペンタエリスリトールヘキサアクリレート、ジペンタエリスリトールモノヒドロキシペンタアクリレート、ジトリメチロールプロパンテトラアクリレート、グリセロールジアクリレート、メトキシ化シクロヘキシルジアクリレート、ネオペンチルグリコールジアクリレート、プロピレングリコールジアクリレート、ポリプロピレングリコールジアクリレート、トリグリセロールジアクリレート、トリメチロールプロパントリアクリレート、アクリルアミド、アミノエチルアクリレートおよび上記化合物の分子内のアクリレートを一部もしくはすべてをメタクリレートに変えたもの、γ−メタクリロキシプロピルトリメトキシシラン、１−ビニル−２−ピロリドンなどが挙げられる。
【００４２】
本発明ではこれらを１種または２種以上使用することができる。これら以外に、不飽和カルボン酸等の不飽和酸を加えることによって、感光後の現像性を向上することができる。不飽和カルボン酸の具体的な例としては、アクリル酸、メタアクリル酸、イタコン酸、クロトン酸、マレイン酸、フマル酸、ビニル酢酸、またはこれらの酸無水物などがあげられる。
【００４３】
一方、感光性オリゴマーや感光性ポリマーとしては、ベンゼン環、ナフタレン環などの芳香環を有するメタクリレートモンマーもしくはアクリレートモノマー、具体的には、フェニル（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、ベンジル（メタ）アクリレート、１−ナフチル（メタ）アクリレート、２−ナフチル（メタ）アクリレート、ビスフェノールＡジ（メタ）アクリレート、ビスフェノールＡ−エチレンオキサイド付加物のジ（メタ）アクリレート、ビスフェノールＡ−プロピレンオキサイド付加物のジ（メタ）アクリレート、チオフェノール（メタ）アクリレート、ベンジルメルカプタン（メタ）アクリレート、また、これらの芳香環の水素原子のうち、１〜５個を塩素または臭素原子に置換したモノマー、上記一般式（Ａ）、（Ｂ）、（Ｃ）に示した化合物、もしくは、スチレン、ｐ−メチルスチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、塩素化スチレン、臭素化スチレン、α−メチルスチレン、塩素化α−メチルスチレン、臭素化α−メチルスチレン、クロロメチルスチレン、ヒドロキシメチルスチレンのうち少なくとも１種類を重合して得られたオリゴマーやポリマーを用いることができる。
【００４４】
重合する際に、これらのモノマーの含有率が１０重量％以上、さらに好ましくは３５重量％以上になるように、他の感光性のモノマーと共重合することができる。共重合するモノマーとしては、前述の炭素−炭素不飽和結合を含有する化合物を用いることができる。
【００４５】
また、不飽和カルボン酸等の不飽和酸を共重合することによって、感光後の現像性を向上することができる。不飽和カルボン酸の具体的な例としては、アクリル酸、メタアクリル酸、イタコン酸、クロトン酸、マレイン酸、フマル酸、ビニル酢酸、またはこれらの酸無水物などがあげられる。
【００４６】
こうして得られた側鎖にカルボキシル基等の酸性基を有するポリマーもしくはオリゴマーの酸価（ＡＶ）は５０〜１８０、さらには７０〜１４０の範囲が好ましい。酸価が５０未満であると、現像許容幅が狭くなる。また、酸価が１８０を越えると未露光部の現像液に対する溶解性が低下するようになるため現像液濃度を濃くすると露光部まで剥がれが発生し、高精細なパターンが得られにくい。
【００４７】
以上示した、ポリマーもしくはオリゴマーに対して、光反応性基を側鎖または分子末端に付加させることによって、感光性を付与することができる。好ましい光反応性基は、エチレン性不飽和基を有するものである。エチレン性不飽和基としては、ビニル基、アリル基、アクリル基、メタクリル基などがあげられる。
【００４８】
このような側鎖をオリゴマーやポリマーに付加させる方法は、ポリマー中のメルカプト基、アミノ基、水酸基やカルボキシル基に対して、グリシジル基やイソシアネート基を有するエチレン性不飽和化合物やアクリル酸クロライド、メタクリル酸クロライドまたはアリルクロライドを付加反応させて作る方法がある。
【００４９】
グリシジル基を有するエチレン性不飽和化合物としては、アクリル酸グリシジル、メタクリル酸グリシジル、アリルグリシジルエーテル、エチルアクリル酸グリシジル、クロトニルグリシジルエーテル、クロトン酸グリシジルエーテル、イソクロトン酸グリシジルエーテルなどがあげられる。
【００５０】
イソシアネート基を有するエチレン性不飽和化合物としては、（メタ）アクリロイルイソシアネート、（メタ）アクリロイルエチルイソシアネート等がある。
【００５１】
また、グリシジル基やイソシアネート基を有するエチレン性不飽和化合物やアクリル酸クロライド、メタクリル酸クロライドまたはアリルクロライドは、ポリマー中のメルカプト基、アミノ基、水酸基やカルボキシル基に対して０．０５〜１モル当量付加させることが好ましい。
【００５２】
本発明において用いられる感光性ペースト中に、バインダー、光重合開始剤、紫外線吸光剤、増感剤、増感助剤、重合禁止剤、可塑剤、増粘剤、有機溶媒、酸化防止剤、分散剤、有機あるいは無機の沈殿防止剤などの添加剤成分を加えることも行われる。
【００５３】
バインダーとしては、ポリビニルアルコール、ポリビニルブチラール、メタクリル酸エステル重合体、アクリル酸エステル重合体、アクリル酸エステル−メタクリル酸エステル共重合体、α−メチルスチレン重合体、ブチルメタクリレート樹脂などがあげられる。このバインダー成分の高屈折率化を行うことも、感光性有機成分の高屈折率化には効果的である。バインダー成分の高屈折率化方法は、前述の感光性ポリマーや感光性オリゴマーにおいて、光反応性基であるエチレン性不飽和基を側鎖または分子末端に付加していないものを用いることができる。つまり、感光性ポリマーや感光性オリゴマーの反応性基を付与する工程を省略したものをバインダーとして用いることができる。
【００５４】
光重合開始剤としての具体的な例として、ベンゾフェノン、ｏ−ベンゾイル安息香酸メチル、４，４−ビス（ジメチルアミン）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、４，４−ジクロロベンゾフェノン、４−ベンゾイル−４−メチルジフェニルケトン、ジベンジルケトン、フルオレノン、２，２−ジエトキシアセトフェノン、２，２−ジメトキシ−２−フェニル−２−フェニルアセトフェノン、２−ヒドロキシ−２−メチルプロピオフェノン、ｐ−ｔ−ブチルジクロロアセトフェノン、チオキサントン、２−メチルチオキサントン、２−クロロチオキサントン、２−イソプロピルチオキサントン、ジエチルチオキサントン、ベンジル、ベンジルジメチルケタノール、ベンジルメトキシエチルアセタール、ベンゾイン、ベンゾインメチルエーテル、ベンゾインブチルエーテル、アントラキノン、２−ｔ−ブチルアントラキノン、２−アミルアントラキノン、β−クロルアントラキノン、アントロン、ベンズアントロン、ジベンゾスベロン、メチレンアントロン、４−アジドベンザルアセトフェノン、２，６−ビス（ｐ−アジドベンジリデン）シクロヘキサノン、２，６−ビス（ｐ−アジドベンジリデン）−４−メチルシクロヘキサノン、２−フェニル−１，２−ブタジオン−２−（ｏ−メトキシカルボニル）オキシム、１−フェニル−プロパンジオン−２−（ｏ−エトキシカルボニル）オキシム、１，３−ジフェニル−プロパントリオン−２−（ｏ−エトキシカルボニル）オキシム、１−フェニル−３−エトキシ−プロパントリオン−２−（ｏ−ベンゾイル）オキシム、ミヒラーケトン、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、ナフタレンスルホニルクロライド、キノリンスルホニルクロライド、Ｎ−フェニルチオアクリドン、４，４−アゾビスイソブチロニトリル、ジフェニルジスルフィド、ベンズチアゾールジスルフィド、トリフェニルホルフィン、カンファーキノン、四臭素化炭素、トリブロモフェニルスルホン、過酸化ベンゾインおよびエオシン、メチレンブルーなどの光還元性の色素とアスコルビン酸、トリエタノールアミンなどの還元剤の組合せなどがあげられる。本発明ではこれらを１種または２種以上使用することができる。光重合開始剤は、感光性成分に対し、０．０５〜１０重量％の範囲で添加され、より好ましくは、０．１〜５重量％である。重合開始剤の量が少なすぎると、光感度が不良となり、光重合開始剤の量が多すぎれば、露光部の残存率が小さくなりすぎるおそれがある。
【００５５】
紫外線吸光剤を添加することも有効である。紫外線吸収効果の高い吸光剤を添加することによって高アスペクト比、高精細、高解像度が得られる。紫外線吸光剤としては有機系染料からなるもの、中でも３５０〜４５０ｎｍの波長範囲で高ＵＶ吸収係数を有する有機系染料が好ましく用いられる。具体的には、アゾ系染料、アミノケトン系染料、キサンテン系染料、キノリン系染料、アミノケトン系染料、アントラキノン系、ベンゾフェノン系、ジフェニルシアノアクリレート系、トリアジン系、ｐ−アミノ安息香酸系染料などが使用できる。有機系染料は吸光剤として添加した場合にも、焼成後の絶縁膜中に残存しないで吸光剤による絶縁膜特性の低下を少なくできるので好ましい。これらの中でもアゾ系およびベンゾフェノン系染料が好ましい。有機染料の添加量は０．０５〜５重量部が好ましい。０．０５重量％以下では紫外線吸光剤の添加効果が減少し、５重量％を越えると焼成後の絶縁膜特性が低下するので好ましくない。より好ましくは０．１５〜１重量％である。有機顔料からなる紫外線吸光剤の添加方法の一例を上げると、有機顔料を予め有機溶媒に溶解した溶液を作製し、次に該有機溶媒中にガラス粉末を混合後、乾燥することによってできる。この方法によってガラス粉末の個々の粉末表面に有機の膜をコートしたいわゆるカプセル状の粉末が作製できる。
【００５６】
本発明において、無機微粒子に含まれるＰｂ、Ｆｅ、Ｃｄ、Ｍｎ、Ｃｏ、Ｍｇなどの金属およびその酸化物がペースト中に含有する感光性成分と反応してペーストが短時間でゲル化し、塗布できなくなる場合がある。このような反応を防止するために安定化剤を添加してゲル化を防止することが好ましい。用いる安定化剤としては、トリアゾール化合物が好ましく用いられる。トリアゾール化合物の中でも特にベンゾトリアゾールが有効に作用する。本発明において使用されるベンゾトリアゾールによるガラス粉末の表面処理の一例を上げると、無機微粒子に対して所定の量のベンゾトリアゾールを酢酸メチル、酢酸エチル、エチルアルコール、メチルアルコールなどの有機溶媒に溶解した後、これら微粒子が十分に浸すことができるように溶液中に１〜２４時間浸積する。浸積後、好ましくは２０〜３０℃下で自然乾燥して溶媒を蒸発させてトリアゾール処理を行った粉末を作製する。使用される安定化剤の割合（安定化剤／無機微粒子）は０．０５〜５重量％が好ましい。
【００５７】
増感剤は、感度を向上させるために添加される。増感剤の具体例としては、２，４−ジエチルチオキサントン、イソプロピルチオキサントン、２，３−ビス（４−ジエチルアミノベンザル）シクロペンタノン、２，６−ビス（４−ジメチルアミニベンザル）シクロヘキサノン、２，６−ビス（４−ジメチルアミノベンザル）−４−メチルシクロヘキサノン、ミヒラーケトン、４，４−ビス（ジエチルアミノ）−ベンゾフェノン、４，４−ビス（ジメチルアミノ）カルコン、４，４−ビス（ジエチルアミノ）カルコン、ｐ−ジメチルアミノシンナミリデンインダノン、ｐ−ジメチルアミノベンジリデンインダノン、２−（ｐ−ジメチルアミノフェニルビニレン）−イソナフトチアゾール、１，３−ビス（４−ジメチルアミノベンザル）アセトン、１，３−カルボニル−ビス（４−ジエチルアミノベンザル）アセトン、３，３−カルボニル−ビス（７−ジエチルアミノクマリン）、Ｎ−フェニル−Ｎ−エチルエタノールアミン、Ｎ−フェニルエタノールアミン、Ｎ−トリルジエタノールアミン、Ｎ−フェニルエタノールアミン、ジメチルアミノ安息香酸イソアミル、ジエチルアミノ安息香酸イソアミル、３−フェニル−５−ベンゾイルチオテトラゾール、１−フェニル−５−エトキシカルボニルチオテトラゾールなどがあげられる。本発明ではこれらを１種または２種以上使用することができる。なお、増感剤の中には光重合開始剤としても使用できるものがある。増感剤を本発明の感光性ペーストに添加する場合、その添加量は有機物量に対して通常０．０５〜４０重量％、より好ましくは５〜４０重量％である。増感剤の量が少なすぎれば光感度を向上させる効果が発揮されない。また、増感剤は、露光波長付近での吸収を有しており、一般的に露光波長での屈折率向上効果が著しい。
【００５８】
重合禁止剤は、保存時の熱安定性を向上させるために添加される。重合禁止剤の具体的な例としては、ヒドロキノン、ヒドロキノンのモノエステル化物、Ｎ−ニトロソジフェニルアミン、フェノチアジン、ｐ−ｔ−ブチルカテコール、Ｎ−フェニルナフチルアミン、２，６−ジ−ｔ−ブチル−ｐ−メチルフェノール、クロラニール、ピロガロールなどが挙げられる。重合禁止剤を添加する場合、その添加量は、感光性ペースト中に、通常、０．００１〜１重量％である。
【００５９】
可塑剤の具体的な例としては、ジブチルフタレート、ジオクチルフタレート、ポリエチレングリコール、グリセリンなどがあげられる。
【００６０】
酸化防止剤は、保存時におけるアクリル系共重合体の酸化を防ぐために添加される。酸化防止剤の具体的な例として２，６−ジ−ｔ−ブチル−ｐ−クレゾール、ブチル化ヒドロキシアニソール、２，６−ジ−ｔ−４−エチルフェノール、２，２−メチレン−ビス−（４−メチル−６−ｔ−ブチルフェノール）、２，２−メチレン−ビス−（４−エチル−６−ｔ−ブチルフェノール）、４，４−ビス−（３−メチル−６−ｔ−ブチルフェノール）、１，１，３−トリス−（２−メチル−６−ｔ−ブチルフェノール）、１，１，３−トリス−（２−メチル−４−ヒドロキシ−ｔ−ブチルフェニル）ブタン、ビス［３，３−ビス−（４−ヒドロキシ−３−ｔ−ブチルフェニル）ブチリックアシッド］グリコールエステル、ジラウリルチオジプロピオナート、トリフェニルホスファイトなどが挙げられる。酸化防止剤を添加する場合、その添加量は通常、添加量は、ペースト中に、通常、０．００１〜１重量％である。
【００６１】
本発明の感光性ペーストには、溶液の粘度を調整したい場合、有機溶媒を加えてもよい。このとき使用される有機溶媒としては、メチルセロソルブ、エチルセロソルブ、ブチルセロソルブ、メチルエチルケトン、ジオキサン、アセトン、シクロヘキサノン、シクロペンタノン、イソブチルアルコール、イソプロピルアルコール、テトラヒドロフラン、ジメチルスルフォキシド、γ−ブチロラクトン、ブロモベンゼン、クロロベンゼン、ジブロモベンゼン、ジクロロベンゼン、ブロモ安息香酸、クロロ安息香酸などやこれらのうちの１種以上を含有する有機溶媒混合物が用いられる。
【００６２】
感光性ペーストは、通常、無機微粒子、紫外線吸光剤、感光性ポリマー、感光性モノマー、光重合開始剤、ガラスフリットおよび溶媒等の各種成分を所定の組成となるように調合した後、３本ローラや混練機で均質に混合分散し作製する。
【００６３】
ペーストの粘度は無機微粒子、増粘剤、有機溶媒、可塑剤および沈殿防止剤などの添加割合によって適宜調整されるが、その範囲は２０００〜２０万ｃｐｓ（センチ・ポイズ）である。例えばガラス基板への塗布をスクリーン印刷法以外にスピンコート法で行う場合は、２０００〜５０００ｃｐｓが好ましい。スクリーン印刷法で１回塗布して膜厚１０〜２０μｍを得るには、５万〜２０万ｃｐｓが好ましい。
【００６４】
次に、感光性ペーストを用いてパターン加工を行う一例について説明するが、本発明はこれに限定されない。
ガラス基板もしくはセラミックスの基板の上に、感光性ペーストを全面塗布、もしくは部分的に塗布する。塗布方法としては、スクリーン印刷、バーコーター、ロールコーター等公知の方法を用いることができる。塗布厚みは、塗布回数、スクリーンのメッシュ、ペーストの粘度を選ぶことによって調整できる。
【００６５】
ここでペーストをガラス基板上に塗布する場合、基板と塗布膜との密着性を高めるために基板の表面処理を行うことができる。表面処理液としてはシランカップリング剤、例えばビニルトリクロロシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、トリス−（２−メトキシエトキシ）ビニルシラン、γ−グリシドキシプロピルトリメトキシシラン、γ−（メタクリロキシプロピル）トリメトキシシラン、γ（２−アミノエチル）アミノプロピルトリメトキシシラン、γ−クロロプロピルトリメトキシシラン、γ−メルカプトプロピルトリメトキシシラン、γ−アミノプロピルトリエトキシシランなどあるいは有機金属例えば有機チタン、有機アルミニウム、有機ジルコニウムなどである。シランカップリング剤あるいは有機金属を有機溶媒例えば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、メチルアルコール、エチルアルコール、プロピルアルコール、ブチルアルコールなどで０．１〜５％の濃度に希釈したものを用いる。次にこの表面処理液をスピナーなどで基板上に均一に塗布した後に８０〜１４０℃で１０〜６０分間乾燥することによって表面処理ができる塗布した上から、フォトマスクを用いて、マスク露光する。用いるマスクは、感光性有機成分の種類によって、ネガ型もしくはポジ型のどちらかを選定する。この際使用される活性光源は、たとえば、近紫外線、紫外線、電子線、Ｘ線などが挙げられるが、これらの中で紫外線が好ましく、その光源としてはたとえば低圧水銀灯、高圧水銀灯、超高圧水銀灯、ハロゲンランプ、殺菌灯などが使用できる。これらのなかでも超高圧水銀灯が好適である。露光条件は塗布厚みによって異なるが、５〜１００ｍＷ／ｃｍ² の出力の超高圧水銀灯を用いて０．１〜３０分間露光を行なう。
【００６６】
感光性ペーストを塗布した後に、その表面に酸素遮蔽膜を設けることによって、パターン形状を向上することができる。酸素遮蔽膜の一例としては、ＰＶＡの膜が挙げられる。ＰＶＡ膜の形成方法は濃度が０．５〜５重量％の水溶液をスピナーなどの方法で基板上に均一に塗布した後に７０〜９０℃で１０〜６０分間好ましいＰＶＡの溶液濃度は、１〜３重量％である。この範囲にあると感度が一層向上する。ＰＶＡ塗布によって感度が向上するのは次の理由が推定される。すなわち感光性成分が光反応する際に、空気中の酸素があると光硬化の感度を妨害すると考えられるが、ＰＶＡの膜があると余分な酸素を遮断できるので露光時に感度が向上するので好ましい。ＰＶＡ以外に水溶性で、透明なポリマー例えばセルロース系のメチルセルロースなども使用できる。
【００６７】
露光後、現像液を使用して現像を行なうが、この場合、浸漬法やスプレー法で行なう。現像液は、感光性ペースト中の有機成分が溶解可能である有機溶媒を使用できる。また該有機溶媒にその溶解力が失われない範囲で水を添加してもよい。感光性ペースト中にカルボキシル基等の酸性基を持つ化合物が存在する場合、アルカリ水溶液で現像できる。アルカリ水溶液として水酸化ナトリウムや水酸化カルシウム水溶液などのような金属アルカリ水溶液を使用できるが、有機アルカリ水溶液を用いた方が焼成時にアルカリ成分を除去しやすいので好ましい。有機アルカリとしては、公知のアミン化合物を用いることができる。具体的には、テトラメチルアンモニウムヒドロキサイド、トリメチルベンジルアンモニウムヒドロキサイド、モノエタノールアミン、ジエタノールアミンなどが挙げられる。アルカリ水溶液の濃度は通常０．０１〜１０重量％、より好ましくは０．１〜５重量％である。アルカリ濃度が低すぎれば未露光部が除去されずに、アルカリ濃度が高すぎれば、パターン部を剥離させ、また露光部を腐食させるおそれがあり良くない。
【００６８】
次に焼成炉にて焼成を行う。焼成雰囲気や温度はペーストや基板の種類によって異なるが、通常は空気中もしくは窒素雰囲気中で焼成する。焼成温度は４００〜１０００℃で行う。ガラス基板上にパターン加工する場合や無機微粒子として銀を用いた場合は、５２０〜６１０℃の温度で１０〜６０分間保持して焼成を行う。
【００６９】
また、以上の工程中に、乾燥、予備反応の目的で、５０〜３００℃加熱工程を導入しても良い。
【００７０】
また、本発明の感光性ペーストをポリエステルフィルムなどの上に塗布することによって、回路材料やディスプレイに用いる感光性グリーンシートを得ることができる。
【００７１】
【実施例】
以下に、本発明を実施例を用いて、具体的に説明する。ただし、本発明はこれに限定はされない。なお、実施例、比較例中の濃度（％）は重量％である。
【００７２】
実施例は、無機微粒子および有機成分からなる感光性ペーストを作成した。作成手順は、まず、有機成分の各成分を８０℃に加熱しながら溶解し、その後、無機微粒子を添加し、混練機で混練することによって、ペーストを作成した。
【００７３】
次に、３０ｃｍ角のソーダガラス基板上に、スクリーン印刷法で複数回塗布によって、１００μｍおよび１５０μｍの塗布厚みになるように塗布を行った後、８０℃で３０分乾燥した。
【００７４】
次に、マスクを用いて露光を行った。マスクは、ピッチ２２０μｍ、線幅６０μｍ、プラズマディスプレイにおけるストライプ状の隔壁パターン形成が可能になるように設計したクロムマスクである。露光は、５０ｍＷ／ｃｍ² の出力の超高圧水銀灯で紫外線露光を行った。
その後、モノエタノールアミンの１％水溶液に浸漬して、現像を行った。
【００７５】
さらに、得られたガラス基板を１２０℃で１時間乾燥した後、５８０℃で１時間焼成を行った。焼成により約２０％程度の収縮が生じる。
【００７６】
評価は、パターン形状（線幅５０μｍ、高さ８０μｍもしくは１２０μｍ、ピッチ２２０μｍがターゲット）を電子顕微鏡観察によって観察した。高さ８０μｍ、１２０μｍ共に良好な形状が得られている場合は○、８０μｍのみ良好な形状が得られている場合を△、８０μｍ、１２０μｍの両方とも欠落などにより良好な形状が得られていない場合を×として評価を行った。
【００７７】
また、有機成分の屈折率は、エリプソメトリー法によって、２５℃における４３６ｎｍの波長の光に関して測定を行った。
【００７８】
ガラス微粒子としては、組成が、ＳｉＯ₂ ；１３％、Ａｌ₂ Ｏ₃ ；２％、Ｂ₂ Ｏ₃ ；１５％、Ｂｉ₂ Ｏ₃ ；３５％、Ｌｉ₂ Ｏ；１０％、ＺｎＯ；５％、Ｎａ₂ Ｏ；１５％、ＺｒＯ₂ ；５％のものを用いた。このガラス微粒子の４３６ｎｍの波長での屈折率は、１．６８であった。
【００７９】
ガラス微粒子は、予めアトライターにて微粉末にした後、プラズマ気流中で球状化処理して作製した粉末で、平均粒子径；３．４μｍ、比表面積；４．１ｍ² ／ｇ、球形率９５個数％の粉末を用いた。球形率の測定は、粉末を光学顕微鏡で３００倍の倍率で撮影し、このうち計測可能な粒子を計数し、球形のものの比率を表す。
【００８０】
実施例１〜６
表１に示す組成の有機物を用いて、感光性ペーストを作製し、パターン作成を行った。
【００８１】
比較例１〜２
表１に示す組成の有機物を用いて、感光性ペーストを作製し、パターン作成を行った。
【００８２】
【表１】

【表２】

【表３】

【００８３】
【発明の効果】
本発明の感光性ペーストによって、高アスペクト比かつ高精度のパターン加工が可能になる。これによって、ディスプレイ、回路材料等の厚膜、高精度のパターン加工が可能になり、精細性の向上、工程の簡略化が可能になる。
【００８４】
特に、簡便に高精度のプラズマディスプレイパネルの隔壁を形成することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel photosensitive paste.
The photosensitive paste of the present invention is used for pattern processing of circuit materials and the like in displays such as plasma displays.
[0002]
[Prior art]
In recent years, circuit materials and displays have been reduced in size and definition, and along with this, improvement in pattern processing technology is also desired. In particular, for forming a partition for a green sheet or a plasma display panel used for a CPU of a computer or the like, there is a demand for a material that is highly accurate and capable of pattern processing with a high aspect ratio.
[0003]
Conventionally, when pattern processing of an inorganic material is performed, screen printing using a paste made of an inorganic powder and an organic binder is often used. However, screen printing has a drawback in that a highly accurate pattern cannot be formed.
[0004]
As methods for improving this problem, JP-A-1-296534, JP-A-2-165538, and JP-A-5-342992 propose a method of forming a photolithographic technique using a photosensitive paste. Yes. However, since the high-aspect ratio and high-definition partition cannot be obtained because the sensitivity and resolution of the photosensitive paste are low, for example, when processing a pattern having a thickness exceeding 80 μm, a plurality of processing steps (screen Printing (exposure / development / development) is required, and there is a drawback that the process becomes long.
[0005]
Japanese Patent Laid-Open No. 2-165538 discloses a method in which a photosensitive paste is coated on transfer paper, and then a transfer film is transferred onto a glass substrate to form partition walls. Japanese Patent Laid-Open No. 3-57138 discloses a photoresist. A method for forming a partition wall by filling a groove of a layer with a dielectric paste has been proposed. Japanese Patent Application Laid-Open No. 4-109536 proposes a method of forming partition walls using a photosensitive organic film. However, these methods have a problem in that the number of processes is increased because a transfer film, a photoresist, or an organic film is required. In addition, a partition wall having high definition and a high aspect ratio has not been obtained.
[0006]
[Problems to be solved by the invention]
As a result of intensive studies on the photosensitive paste without the above disadvantages, the present inventors have reached the following invention. In particular, an object is to provide a photosensitive paste that enables high-aspect ratio and high-precision pattern processing.
[0007]
[Means for Solving the Problems]
The present invention is characterized in that by controlling the refractive index of the organic component in the photosensitive paste, reflection / scattering at the interface with the inorganic component is reduced, and pattern processing with high aspect ratio and high accuracy is performed. It relates to a photosensitive paste.
[0008]
An object of the present invention is composed of inorganic fine particles containing glass fine particles and an organic component containing a photosensitive compound. For pattern processing A photosensitive paste, wherein the glass fine particles contain 5 to 80% by weight of at least one of bismuth oxide, lead oxide, and lithium oxide, and the photosensitive compound is a benzene ring, naphthalene ring, biphenyl ring, anthracene ring, It contains at least one of a thiophene ring and a carbazole ring, and the refractive index of the organic component is 1.56 to 1.80 For pattern processing This is achieved with a photosensitive paste.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The inorganic fine particles are fine particles such as glass, ceramics and metals (gold, platinum, silver, copper, nickel, aluminum, palladium, tungsten, ruthenium oxide, etc.) generally used for electronic materials.
[0010]
The case of 50 to 95 parts by weight of inorganic fine particles and 5 to 50 parts by weight of organic components is excellent in pattern processing characteristics.
[0011]
Particularly useful in the present invention is when fine glass particles are used as the inorganic fine particles. It is preferable to use glass particles in 60% by weight or more of the inorganic particles.
[0012]
The glass fine particles are not particularly limited as long as they are known, but by using 50% by weight or more of glass fine particles having a heat softening temperature of 350 to 600 ° C., pattern processing is performed on a glass substrate used for a normal display. it can.
[0013]
As such glass fine particles, glass fine particles containing 5 to 80% by weight of at least one of bismuth oxide, lead oxide, and lithium oxide can be used. From the viewpoint of the pot life and insulating properties of the paste, bismuth oxide. It is preferable to use glass fine particles containing 5 to 50% by weight.
[0014]
As a glass composition containing bismuth oxide,
Bi ₂ O _Three 5-50% by weight
SiO ₂ 3-60% by weight
B ₂ O _Three 5-40% by weight
It is preferable to use glass fine particles containing the above components, and further, the glass fine particles are expressed in terms of oxides.
Bi ₂ O _Three 5-50% by weight
SiO ₂ 3-60% by weight
B ₂ O _Three 5-40% by weight
BaO 0-25% by weight
Al ₂ O _Three 0 to 5% by weight
ZnO 2-40% by weight
It was found that an excellent pattern can be formed on a glass substrate by using glass fine particles containing the above components.
[0015]
In glass powder, Li ₂ O can be contained, but the amount is preferably 60% by weight or less.
Also, in the glass powder, CaO, TiO ₂ , ZrO ₂ Etc., but the amount is preferably 20% by weight or less.
Na ₂ O, K ₂ O, Y ₂ O _Three It is preferable that the metal oxide such as 5% by weight or less.
[0016]
The composition in the glass powder is SiO ₂ Is preferably blended in the range of 3 to 60% by weight, and if it is less than 3% by weight, the denseness, strength and stability of the glass layer are lowered, and there is a mismatch between the glass substrate and the thermal expansion coefficient. Deviates from the value. Moreover, by making it 60 weight% or less, there exists an advantage that a thermal softening point becomes low and baking to a glass substrate is attained.
[0017]
B ₂ O _Three By blending in the range of 5 to 40% by weight, electrical, mechanical and thermal properties such as electrical insulation, strength, thermal expansion coefficient, and denseness of the insulating layer can be improved. On the other hand, if it exceeds 40% by weight, the stability of the glass is lowered.
[0018]
Bi ₂ O _Three Is preferably 5 to 80% by weight, more preferably 5 to 60% by weight, and still more preferably 5 to 50% by weight. If it is less than 5% by weight, it is less effective to control the baking temperature when baking the glass paste on the glass substrate. If it exceeds 80% by weight, the heat-resistant temperature of the glass becomes too low and baking onto the glass substrate becomes difficult.
[0019]
ZnO is preferably blended in the range of 2 to 40% by weight. If it exceeds 40% by weight, the temperature for baking onto the glass substrate becomes too low to be controlled, and the insulation resistance becomes low, which is not preferable.
[0020]
The particle size of the glass powder used in the above is selected in consideration of the shape of the pattern to be produced, but the 50% by weight particle size is preferably 0.1 to 10 μm.
[0021]
Further, the inventors have found that high aspect ratio patterning is possible by using glass fine particles having a spherical shape as glass fine particles. By using 50% by weight or more of glass particles having a sphericity of 80% by number or more as glass particles, the glass surface area can be reduced and light scattering in the paste can be suppressed.
[0022]
Further, it is preferable to use glass fine particles characterized by using glass fine particles having a total light transmittance of 50% or more at a wavelength of 436 nm as glass fine particles. The pattern characteristics are improved by suppressing scattering and absorption inside the glass fine particles.
[0023]
As the glass fine particles used in this case, the 50 wt% particle size is 1 to 7 µm, the 10 wt% particle size is 0.4 to 2 µm, the 90 wt% particle size is 4 to 10 µm, and the specific surface area is 0.2 to 3 m. ² / G of glass particles are suitable.
[0024]
The glass containing the above bismuth oxide, lead oxide, and lithium oxide has an average refractive index of 1.56 to 1.80, and in many cases 1.60 to 1.80. In this case, when the average refractive index of the organic component is 1.56 or less, the refractive index difference between the organic component and the inorganic fine particles is large, and pattern formation becomes difficult due to light scattering.
[0025]
Accordingly, the inventors have found that a photosensitive paste containing an organic component having a refractive index of 1.56 or more, and further 1.60 or more is high even when glass fine particles having a glass transition point of 350 to 550 ° C. are used. It was found that the aspect ratio is effective for high-precision patterning. However, when the average refractive index of the organic component is 1.80 or more, the refractive index is too high, and conversely, light scattering becomes too large, which is not preferable.
[0026]
In particular, when glass particles containing 10% by weight or more of bismuth oxide are used, the refractive index of the organic component is preferably 1.56 or more.
[0027]
Moreover, the pattern workability at the time of thick film is further improved by making the difference in the average refractive index between the organic component used and the inorganic fine particles 0.05 or less. The difference in average refractive index is an absolute value obtained by subtracting the average refractive index of organic matter from the average refractive index of inorganic fine particles.
[0028]
In the measurement of the refractive index in the present invention, it is accurate to confirm the effect by measuring the wavelength of the ultraviolet light to be irradiated after applying the paste. In particular, it is preferable to measure with light having a wavelength in the range of 350 to 480 nm. Furthermore, refractive index measurement with i-line (365 nm) or g-line (436 nm) is preferable.
[0029]
The organic component includes a photosensitive component selected from at least one of a photosensitive monomer, a photosensitive oligomer, and a photosensitive polymer, and a binder, a photopolymerization initiator, an ultraviolet light absorber, a sensitizer, a sensitization aid, Addition components such as a polymerization inhibitor, a plasticizer, a thickener, an organic solvent, an antioxidant, a dispersant, an organic or inorganic precipitation inhibitor are also added.
[0030]
As a result of intensive studies, the inventors have found the following method as a method for setting the refractive index of the organic component to 1.56 to 1.80.
[0031]
(1) The organic component contains 10 to 80% by weight of halogen atoms such as sulfur atom, bromine atom, chlorine atom and iodine atom.
(2) The organic component contains 10 to 80% by weight, preferably 20 to 80% by weight, of at least one of a benzene ring, naphthalene ring, biphenyl ring, anthracene ring, thiophene ring and carbazole ring.
It is considered that the most effective method is to contain the above-mentioned elements and cyclic groups in the photosensitive component in the organic component.
[0032]
Regarding the photosensitive paste used in the present invention, the content of the photosensitive component is preferably 10% by weight or more in the organic component from the viewpoint of sensitivity to light. Furthermore, it is preferable that it is 30 weight% or more.
[0033]
As the photosensitive component, there are a light-insolubilized type and a light-solubilized type,
(1) Containing a functional monomer, oligomer or polymer having one or more unsaturated groups in the molecule
(2) Containing photosensitive compounds such as aromatic diazo compounds, aromatic azide compounds, and organic halogen compounds
(3) So-called diazo resins such as condensates of diazo amines and formaldehyde
Etc. In addition, as a light-soluble type,
(4) Containing inorganic salts of diazo compounds and organic acids, quinonediazos
(5) Naphthoquinone 1,2-diazide-5-sulfonic acid ester of, for example, phenol or novolak resin, in which quinonediazos are combined with a suitable polymer binder
Etc.
[0034]
Although all the above-mentioned photosensitive components can be used in the present invention, (1) most easily has a refractive index of 1.56 or more. As a method for increasing the refractive index of the photosensitive component, there is a method using at least one of a photosensitive monomer, a photosensitive oligomer, and a photosensitive polymer having a high refractive index.
[0035]
As the photosensitive monomer, use of a methacrylate monomer or an acrylate monomer containing an aromatic ring such as a benzene ring or a naphthalene ring is effective for increasing the refractive index.
[0036]
Specifically, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A -Di (meth) acrylate of ethylene oxide adduct, di (meth) acrylate of bisphenol A-propylene oxide adduct, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, thiophenol (meth) acrylate, benzyl Mercaptans (meth) acrylates or compounds in which 1 to 5 hydrogen atoms in these aromatic rings are substituted with chlorine or bromine atoms can be used.
[0037]
In addition, as a monomer containing a sulfur atom in the molecule, there is a compound having a sulfur content of 15% by weight or more and having at least one polymerizable unsaturated bond, and the following compounds are listed. It is done.
[0038]
(1) Monomer having a thiol (meth) acrylate group in the molecule
(2) Monomers containing a phenyl sulfide structure in the molecule
Specific examples of the monomer include thiol (meth) acrylate monomers represented by the following general formula (A), (B) or (C).
[0039]
R in the structural formula represents a hydrogen atom or a methyl group.
[0040]
[Chemical 1]

Various monomers that can improve the refractive index can be mixed and used.
[0041]
The photosensitive monomer is a compound containing a carbon-carbon unsaturated bond, and specific examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, sec. -Butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-pentyl acrylate, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2 -Ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate, heptadecafluorodecyl acrylate, 2 Hydroxyethyl acrylate, isobornyl acrylate, 2-hydroxypropyl acrylate, isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluoropentyl acrylate, phenoxyethyl acrylate, Stearyl acrylate, trifluoroethyl acrylate, allylated cyclohexyl diacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol di Acrylate, dipipe Taerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, methoxylated cyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, triglycerol diacrylate, Examples include trimethylolpropane triacrylate, acrylamide, aminoethyl acrylate, and those obtained by changing some or all of the acrylates in the molecule to methacrylate, γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone, etc. It is done.
[0042]
In the present invention, one or more of these can be used. In addition to these, the development property after exposure can be improved by adding an unsaturated acid such as an unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.
[0043]
On the other hand, as a photosensitive oligomer or photosensitive polymer, a methacrylate monomer or acrylate monomer having an aromatic ring such as a benzene ring or a naphthalene ring, specifically, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl ( Of (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, bisphenol A di (meth) acrylate, di (meth) acrylate of bisphenol A-ethylene oxide adduct, bisphenol A-propylene oxide adduct Di (meth) acrylate, thiophenol (meth) acrylate, benzyl mercaptan (meth) acrylate, and monomers obtained by substituting 1 to 5 of these aromatic ring hydrogen atoms with chlorine or bromine atoms, Compounds represented by the general formulas (A), (B), (C), or styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, chlorinated styrene, brominated styrene, α-methylstyrene, An oligomer or polymer obtained by polymerizing at least one of chlorinated α-methylstyrene, brominated α-methylstyrene, chloromethylstyrene, and hydroxymethylstyrene can be used.
[0044]
In the polymerization, it can be copolymerized with other photosensitive monomers so that the content of these monomers is 10% by weight or more, more preferably 35% by weight or more. As the monomer to be copolymerized, the aforementioned compound containing a carbon-carbon unsaturated bond can be used.
[0045]
Moreover, the developability after exposure can be improved by copolymerizing an unsaturated acid such as an unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.
[0046]
The acid value (AV) of the polymer or oligomer having an acidic group such as a carboxyl group in the side chain thus obtained is preferably 50 to 180, more preferably 70 to 140. When the acid value is less than 50, the allowable development width becomes narrow. Further, if the acid value exceeds 180, the solubility of the unexposed portion in the developing solution is lowered. Therefore, if the concentration of the developing solution is increased, the exposed portion is peeled off and it is difficult to obtain a high-definition pattern.
[0047]
Photosensitivity can be imparted to the polymer or oligomer shown above by adding a photoreactive group to the side chain or molecular end. Preferred photoreactive groups are those having an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acrylic group, and a methacryl group.
[0048]
Such a side chain can be added to an oligomer or polymer by using an ethylenically unsaturated compound having a glycidyl group or an isocyanate group relative to a mercapto group, amino group, hydroxyl group or carboxyl group in the polymer. There is a method of making an acid chloride or allyl chloride by addition reaction.
[0049]
Examples of the ethylenically unsaturated compound having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, glycidyl crotonic acid, glycidyl ether of isocrotonic acid, and the like.
[0050]
Examples of the ethylenically unsaturated compound having an isocyanate group include (meth) acryloyl isocyanate and (meth) acryloylethyl isocyanate.
[0051]
In addition, the ethylenically unsaturated compound having a glycidyl group or an isocyanate group, acrylic acid chloride, methacrylic acid chloride or allyl chloride is 0.05 to 1 molar equivalent with respect to a mercapto group, amino group, hydroxyl group or carboxyl group in the polymer. It is preferable to add.
[0052]
In the photosensitive paste used in the present invention, binder, photopolymerization initiator, ultraviolet light absorber, sensitizer, sensitizer, polymerization inhibitor, plasticizer, thickener, organic solvent, antioxidant, dispersion An additive component such as an additive or an organic or inorganic suspending agent is also added.
[0053]
Examples of the binder include polyvinyl alcohol, polyvinyl butyral, methacrylic ester polymer, acrylic ester polymer, acrylic ester-methacrylic ester copolymer, α-methylstyrene polymer, and butyl methacrylate resin. Increasing the refractive index of the binder component is also effective for increasing the refractive index of the photosensitive organic component. As a method for increasing the refractive index of the binder component, the above-described photosensitive polymer or photosensitive oligomer in which an ethylenically unsaturated group that is a photoreactive group is not added to a side chain or a molecular end can be used. That is, what omitted the process which provides the reactive group of a photosensitive polymer or a photosensitive oligomer can be used as a binder.
[0054]
Specific examples of the photopolymerization initiator include benzophenone, methyl o-benzoylbenzoate, 4,4-bis (dimethylamine) benzophenone, 4,4-bis (diethylamino) benzophenone, 4,4-dichlorobenzophenone, 4 -Benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenyl-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, p -T-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyl, benzyldimethylketanol, benzylmethoxyethyl acetal, benzoy , Benzoin methyl ether, benzoin butyl ether, anthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzosuberone, methyleneanthrone, 4-azidobenzalacetophenone, 2,6- Bis (p-azidobenzylidene) cyclohexanone, 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone, 2-phenyl-1,2-butadion-2- (o-methoxycarbonyl) oxime, 1-phenyl- Propanedion-2- (o-ethoxycarbonyl) oxime, 1,3-diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoyl) ) Oxime, Michler's ketone, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, naphthalenesulfonyl chloride, quinolinesulfonyl chloride, N-phenylthioacridone, 4,4-azobisisobutyro Photoreducing dyes such as nitrile, diphenyl disulfide, benzthiazole disulfide, triphenylformine, camphorquinone, carbon tetrabromide, tribromophenyl sulfone, benzoin peroxide and eosin, methylene blue and ascorbic acid, triethanolamine, etc. Examples include a combination of reducing agents. In the present invention, one or more of these can be used. A photoinitiator is added in 0.05-10 weight% with respect to the photosensitive component, More preferably, it is 0.1-5 weight%. If the amount of the polymerization initiator is too small, the photosensitivity will be poor, and if the amount of the photopolymerization initiator is too large, the residual ratio of the exposed area may be too small.
[0055]
It is also effective to add an ultraviolet light absorber. A high aspect ratio, high definition, and high resolution can be obtained by adding a light-absorbing agent having a high ultraviolet absorption effect. As the ultraviolet light absorber, an organic dye, particularly an organic dye having a high UV absorption coefficient in a wavelength range of 350 to 450 nm is preferably used. Specifically, azo dyes, amino ketone dyes, xanthene dyes, quinoline dyes, amino ketone dyes, anthraquinone dyes, benzophenone dyes, diphenyl cyanoacrylate dyes, triazine dyes, p-aminobenzoic acid dyes, and the like can be used. . Even when an organic dye is added as a light-absorbing agent, it is preferable because it does not remain in the insulating film after baking and the deterioration of the insulating film characteristics due to the light-absorbing agent can be reduced. Of these, azo dyes and benzophenone dyes are preferable. The addition amount of the organic dye is preferably 0.05 to 5 parts by weight. If it is 0.05% by weight or less, the effect of adding an ultraviolet light absorber is reduced, and if it exceeds 5% by weight, the insulating film properties after firing are deteriorated. More preferably, it is 0.15-1 weight%. An example of a method for adding an ultraviolet light absorber composed of an organic pigment is as follows. A solution in which an organic pigment is previously dissolved in an organic solvent is prepared, and then glass powder is mixed in the organic solvent and then dried. By this method, a so-called capsule-shaped powder in which an organic film is coated on the surface of each glass powder can be produced.
[0056]
In the present invention, the metal such as Pb, Fe, Cd, Mn, Co, and Mg contained in the inorganic fine particles and the oxide thereof react with the photosensitive component contained in the paste to be gelled and applied in a short time. It may disappear. In order to prevent such a reaction, it is preferable to add a stabilizer to prevent gelation. As a stabilizer to be used, a triazole compound is preferably used. Among the triazole compounds, benzotriazole works particularly effectively. As an example of the surface treatment of glass powder with benzotriazole used in the present invention, a predetermined amount of benzotriazole with respect to inorganic fine particles was dissolved in an organic solvent such as methyl acetate, ethyl acetate, ethyl alcohol, and methyl alcohol. Thereafter, it is immersed in the solution for 1 to 24 hours so that these fine particles can be sufficiently immersed. After soaking, it is preferably air-dried at 20 to 30 ° C. to evaporate the solvent to produce a triazole-treated powder. The proportion of the stabilizer used (stabilizer / inorganic fine particles) is preferably 0.05 to 5% by weight.
[0057]
A sensitizer is added in order to improve sensitivity. Specific examples of the sensitizer include 2,4-diethylthioxanthone, isopropylthioxanthone, 2,3-bis (4-diethylaminobenzal) cyclopentanone, 2,6-bis (4-dimethylaminibenzal) cyclohexanone, 2,6-bis (4-dimethylaminobenzal) -4-methylcyclohexanone, Michler's ketone, 4,4-bis (diethylamino) -benzophenone, 4,4-bis (dimethylamino) chalcone, 4,4-bis (diethylamino) ) Chalcone, p-dimethylaminocinnamylidene indanone, p-dimethylaminobenzylidene indanone, 2- (p-dimethylaminophenylvinylene) -isonaphthothiazole, 1,3-bis (4-dimethylaminobenzal) acetone 1,3-carbonyl-bis (4-diethylamino) Benzal) acetone, 3,3-carbonyl-bis (7-diethylaminocoumarin), N-phenyl-N-ethylethanolamine, N-phenylethanolamine, N-tolyldiethanolamine, N-phenylethanolamine, isoamyl dimethylaminobenzoate And isoamyl diethylaminobenzoate, 3-phenyl-5-benzoylthiotetrazole, 1-phenyl-5-ethoxycarbonylthiotetrazole and the like. In the present invention, one or more of these can be used. Some sensitizers can also be used as photopolymerization initiators. When adding a sensitizer to the photosensitive paste of this invention, the addition amount is 0.05 to 40 weight% normally with respect to the amount of organic substances, More preferably, it is 5 to 40 weight%. If the amount of the sensitizer is too small, the effect of improving the photosensitivity is not exhibited. Further, the sensitizer has absorption near the exposure wavelength, and generally has a remarkable effect of improving the refractive index at the exposure wavelength.
[0058]
A polymerization inhibitor is added to improve the thermal stability during storage. Specific examples of the polymerization inhibitor include hydroquinone, monoester of hydroquinone, N-nitrosodiphenylamine, phenothiazine, pt-butylcatechol, N-phenylnaphthylamine, 2,6-di-tert-butyl-p- Examples include methylphenol, chloranil, and pyrogallol. When adding a polymerization inhibitor, the addition amount is 0.001 to 1 weight% normally in the photosensitive paste.
[0059]
Specific examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, polyethylene glycol, glycerin and the like.
[0060]
The antioxidant is added to prevent oxidation of the acrylic copolymer during storage. Specific examples of antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-4-ethylphenol, 2,2-methylene-bis- ( 4-methyl-6-tert-butylphenol), 2,2-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4-bis- (3-methyl-6-tert-butylphenol), 1 , 1,3-Tris- (2-methyl-6-tert-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-tert-butylphenyl) butane, bis [3,3-bis -(4-Hydroxy-3-t-butylphenyl) butyric acid] glycol ester, dilauryl thiodipropionate, triphenyl phosphite and the like. When adding an antioxidant, the addition amount is usually 0.001 to 1% by weight in the paste.
[0061]
An organic solvent may be added to the photosensitive paste of the present invention in order to adjust the viscosity of the solution. As the organic solvent used at this time, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, Chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, and the like, and organic solvent mixtures containing one or more of these are used.
[0062]
The photosensitive paste is usually prepared by blending various components such as inorganic fine particles, ultraviolet light absorber, photosensitive polymer, photosensitive monomer, photopolymerization initiator, glass frit and solvent so as to have a predetermined composition, and then a three-roller. Or by mixing and dispersing homogeneously with a kneader.
[0063]
The viscosity of the paste is appropriately adjusted depending on the addition ratio of inorganic fine particles, thickener, organic solvent, plasticizer, precipitation inhibitor, etc., but the range is 2000 to 200,000 cps (centipoise). For example, when the coating on the glass substrate is performed by a spin coating method other than the screen printing method, 2000 to 5000 cps is preferable. In order to obtain a film thickness of 10 to 20 μm by a single screen printing method, 50,000 to 200,000 cps is preferable.
[0064]
Next, an example of performing pattern processing using a photosensitive paste will be described, but the present invention is not limited to this.
On the glass substrate or ceramic substrate, the photosensitive paste is applied over the entire surface or partially. As a coating method, known methods such as screen printing, bar coater, roll coater and the like can be used. The coating thickness can be adjusted by selecting the number of coatings, screen mesh, and paste viscosity.
[0065]
Here, when the paste is applied on the glass substrate, the substrate can be subjected to a surface treatment in order to improve the adhesion between the substrate and the coating film. As the surface treatment liquid, silane coupling agents such as vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, tris- (2-methoxyethoxy) vinylsilane, γ-glycidoxypropyltrimethoxysilane, γ- (methacryloxy) Propyl) trimethoxysilane, γ (2-aminoethyl) aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, or organic metals such as organic titanium, Organic aluminum, organic zirconium and the like. A silane coupling agent or an organic metal diluted with an organic solvent such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl alcohol, ethyl alcohol, propyl alcohol, or butyl alcohol to a concentration of 0.1 to 5% is used. Next, this surface treatment liquid is uniformly applied on a substrate with a spinner or the like, and then subjected to surface treatment by drying at 80 to 140 ° C. for 10 to 60 minutes, and then mask exposure is performed using a photomask. As the mask to be used, either a negative type or a positive type is selected depending on the type of the photosensitive organic component. Examples of the active light source used at this time include near ultraviolet rays, ultraviolet rays, electron beams, and X-rays. Among these, ultraviolet rays are preferable, and examples of the light sources include low pressure mercury lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, Halogen lamps and germicidal lamps can be used. Among these, an ultrahigh pressure mercury lamp is suitable. The exposure conditions vary depending on the coating thickness, but 5 to 100 mW / cm. ² The exposure is performed for 0.1 to 30 minutes using an ultrahigh pressure mercury lamp with the output of
[0066]
After applying the photosensitive paste, the pattern shape can be improved by providing an oxygen shielding film on the surface. An example of the oxygen shielding film is a PVA film. The PVA film is formed by uniformly applying an aqueous solution having a concentration of 0.5 to 5% by weight on a substrate by a method such as a spinner, and the preferable PVA solution concentration is 1 to 3 at 70 to 90 ° C. for 10 to 60 minutes. % By weight. Within this range, the sensitivity is further improved. The following reasons are presumed that the sensitivity is improved by application of PVA. That is, when the photosensitive component undergoes a photoreaction, oxygen in the air is thought to interfere with the sensitivity of photocuring, but a PVA film is preferable because it can block excess oxygen and improve sensitivity during exposure. . In addition to PVA, water-soluble and transparent polymers such as cellulosic methylcellulose can also be used.
[0067]
After the exposure, development is performed using a developer. In this case, the immersion method or the spray method is used. As the developer, an organic solvent capable of dissolving the organic components in the photosensitive paste can be used. Further, water may be added to the organic solvent as long as its dissolving power is not lost. When a compound having an acidic group such as a carboxyl group is present in the photosensitive paste, development can be performed with an aqueous alkaline solution. A metal alkali aqueous solution such as sodium hydroxide or calcium hydroxide aqueous solution can be used as the alkali aqueous solution. However, it is preferable to use an organic alkali aqueous solution because an alkali component can be easily removed during firing. A known amine compound can be used as the organic alkali. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, and diethanolamine. The concentration of the alkaline aqueous solution is usually 0.01 to 10% by weight, more preferably 0.1 to 5% by weight. If the alkali concentration is too low, the unexposed portion is not removed, and if the alkali concentration is too high, the pattern portion may be peeled off and the exposed portion may be corroded.
[0068]
Next, firing is performed in a firing furnace. The firing atmosphere and temperature vary depending on the type of paste and substrate, but are usually fired in air or in a nitrogen atmosphere. The firing temperature is 400 to 1000 ° C. When patterning is performed on a glass substrate or when silver is used as the inorganic fine particles, firing is performed by holding at a temperature of 520 to 610 ° C. for 10 to 60 minutes.
[0069]
Moreover, you may introduce | transduce a 50-300 degreeC heating process in the above process for the purpose of drying and a preliminary reaction.
[0070]
Moreover, the photosensitive green sheet used for a circuit material or a display can be obtained by apply | coating the photosensitive paste of this invention on a polyester film etc.
[0071]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to this. The concentration (%) in Examples and Comparative Examples is% by weight.
[0072]
In Examples, a photosensitive paste composed of inorganic fine particles and an organic component was prepared. In the preparation procedure, first, each component of the organic component was dissolved while being heated to 80 ° C., and then inorganic fine particles were added and kneaded with a kneader to prepare a paste.
[0073]
Next, coating was performed on a 30 cm square soda glass substrate by screen printing so as to have a coating thickness of 100 μm and 150 μm, followed by drying at 80 ° C. for 30 minutes.
[0074]
Next, exposure was performed using a mask. The mask is a chromium mask designed to enable the formation of stripe-shaped barrier rib patterns in a plasma display with a pitch of 220 μm and a line width of 60 μm. Exposure is 50mW / cm ² UV exposure was performed with an ultra-high pressure mercury lamp with an output of.
Then, it developed by immersing in the 1% aqueous solution of monoethanolamine.
[0075]
Furthermore, after drying the obtained glass substrate at 120 degreeC for 1 hour, it baked at 580 degreeC for 1 hour. Shrinkage of about 20% occurs by firing.
[0076]
In the evaluation, a pattern shape (a line width of 50 μm, a height of 80 μm or 120 μm, and a pitch of 220 μm is a target) was observed with an electron microscope. If a good shape is obtained for both 80 μm and 120 μm in height, ○ indicates that a good shape is obtained only for 80 μm, and Δ indicates that a good shape is not obtained for both 80 μm and 120 μm. Was evaluated as x.
[0077]
The refractive index of the organic component was measured with respect to light having a wavelength of 436 nm at 25 ° C. by an ellipsometry method.
[0078]
Glass fine particles have a composition of SiO ₂ ; 13%, Al ₂ O _Three 2%, B ₂ O _Three ; 15%, Bi ₂ O _Three 35% Li ₂ O; 10%, ZnO; 5%, Na ₂ O: 15%, ZrO ₂ 5% was used. The refractive index of the glass fine particles at a wavelength of 436 nm was 1.68.
[0079]
The glass fine particles are powders prepared by making fine powders with an attritor in advance and then spheroidizing in a plasma stream. ² / G, a powder having a sphericity of 95% by number was used. In the measurement of the sphericity, the powder is photographed with an optical microscope at a magnification of 300 times, and among these, the measurable particles are counted, and the ratio of the spheres is expressed.
[0080]
Examples 1-6
A photosensitive paste was prepared using an organic material having a composition shown in Table 1, and a pattern was formed.
[0081]
Comparative Examples 1-2
A photosensitive paste was prepared using an organic material having a composition shown in Table 1, and a pattern was formed.
[0082]
[Table 1]

[Table 2]

[Table 3]

[0083]
【The invention's effect】
The photosensitive paste of the present invention enables pattern processing with a high aspect ratio and high accuracy. As a result, thick films such as displays and circuit materials and high-accuracy pattern processing can be performed, so that the definition can be improved and the process can be simplified.
[0084]
In particular, it is possible to easily form a high-precision partition wall of a plasma display panel.

Claims (15)

A photosensitive paste for pattern processing comprising inorganic fine particles containing glass fine particles and an organic component containing a photosensitive compound, wherein the glass fine particles contain at least one of bismuth oxide, lead oxide, and lithium oxide in an amount of 5 to 80. The photosensitive compound contains at least one of a benzene ring, a naphthalene ring, a biphenyl ring, an anthracene ring, a thiophene ring, and a carbazole ring, and the refractive index of the organic component is 1.56 to A photosensitive paste for pattern processing, which is 1.80. The photosensitive paste for pattern processing according to claim 1, comprising 50 to 95 parts by weight of inorganic fine particles and 5 to 50 parts by weight of an organic component. 3. The photosensitive paste for pattern processing according to claim 1, wherein the glass fine particles are contained in an amount of 60% by weight or more of the inorganic fine particles. The photosensitive paste for pattern processing according to claim 1, wherein glass fine particles having a heat softening temperature of 350 to 600 ° C. are used as the glass fine particles. Glass fine particles, Bi ₂ O ₃ 5 to 50% by weight in terms of oxide
SiO ₂ 3-60% by weight
B ₂ O ₃ 5-40% by weight
5. The pattern processing photosensitive paste according to claim 1, wherein glass fine particles containing any of the components are used. Glass fine particles, Bi ₂ O ₃ 5 to 50% by weight in terms of oxide
SiO ₂ 3-60% by weight
B ₂ O ₃ 5-40% by weight
BaO 0-25% by weight
Al ₂ O ₃ 0-5% by weight
ZnO 2-40% by weight
Glass fine particles containing the above components are used. The pattern processing photosensitive paste according to any one of claims 1 to 5. The photosensitive paste for pattern processing according to any one of claims 1 to 6, wherein glass fine particles having a sphericity of 80% by number or more are used as the glass fine particles. The photosensitive paste for pattern processing according to any one of claims 1 to 7, wherein glass fine particles having a total light transmittance of 50% or more at a wavelength of 436 nm are used as the glass fine particles. 9. The photosensitive material for pattern processing according to claim 1, wherein the organic component contains 10 to 90% by weight of an oligomer or polymer containing a carboxyl group in the molecule and having a weight average molecular weight of 500 to 100,000. Sex paste. The pattern according to any one of claims 1 to 9, wherein the organic component contains 10 to 90% by weight of an oligomer or polymer having an unsaturated double bond in the molecule and having a weight average molecular weight of 500 to 100,000. Photosensitive paste for processing . The photosensitive paste for pattern processing according to any one of claims 1 to 10, wherein the organic component contains 10 to 80% by weight of a polyfunctional polyfunctional acrylate compound and / or a methacrylate compound. The photosensitive paste for pattern processing according to any one of claims 1 to 11, wherein the organic component contains 0.05 to 5% by weight of a compound having ultraviolet absorption characteristics. The pattern according to any one of claims 1 to 12, wherein a photosensitive compound having a total content of sulfur atom, bromine atom, chlorine atom and iodine atom of 10 to 80% by weight is used in the organic component. Photosensitive paste for processing . The photosensitive paste for pattern processing according to any one of claims 1 to 13, wherein an organic component containing 5 to 40% by weight of a photosensitizer is used. The photosensitive paste for pattern processing according to claim 1, which is used for forming partition walls in a plasma display or a plasma addressed liquid crystal display.