JP3932847B2 - ORGANIC EL ELEMENT AND ITS MANUFACTURING METHOD, EL DISPLAY, ELECTRONIC DEVICE - Google Patents

Description

【００４０】
このような共役系高分子有機化合物は固体で強い蛍光を持ち、均質な固体超薄膜を形成することができる。しかも形成能に富みＩＴＯ電極との密着性も高い。さらに、このような化合物の前駆体は、硬化した後は強固な共役系高分子膜を形成することから、加熱硬化前においては前駆体溶液を後述するインクジェットパターニングに適用可能な所望の粘度に調整することができ、簡便かつ短時間で最適条件の膜形成を行うことができる。
【００４１】
このような前駆体としては、例えばＰＰＶ（ポリ（パラ−フェニレンビニレン））またはその誘導体の前駆体が好ましい。ＰＰＶまたはその誘導体の前駆体は、水あるいは有機溶媒に可溶であり、また、ポリマー化が可能であるため光学的にも高品質の薄膜を得ることができる。さらに、ＰＰＶは強い蛍光を持ち、また二重結合のπ電子がポリマー鎖上で非極在化している導電性高分子でもあるため、高性能の有機ＥＬ素子を得ることができる。
【００４２】
このようなＰＰＶまたはＰＰＶ誘導体の前駆体として、例えば化学式（ＩＩ）に示すような、ＰＰＶ（ポリ（パラ−フェニレンビニレン））前駆体、ＭＯ−ＰＰＶ（ポリ（２，５−ジメトキシ−１，４−フェニレンビニレン））前駆体、ＣＮ−ＰＰＶ（ポリ（２，５−ビスヘキシルオキシ−１，４−フェニレン−（１−シアノビニレン）））前駆体、ＭＥＨ−ＰＰＶ（ポリ［２−メトキシ−５−（２’−エチルヘキシルオキシ）］−パラ−フェニレンビニレン）前駆体等が挙げられる。
【００４３】
【化２】

【００４４】
ＰＰＶまたはＰＰＶ誘導体の前駆体は、前述したように水に可溶であり、成膜後の加熱により高分子化してＰＰＶ層を形成する。前記ＰＰＶ前駆体に代表される前駆体の含有量は、組成物全体に対して０．０１〜１０．０ｗｔ％が好ましく、０．１〜５．０ｗｔ％がさらに好ましい。前駆体の添加量が少な過ぎると共役系高分子膜を形成するのに不十分であり、多過ぎると組成物の粘度が高くなり、インクジェット法による精度の高いパターニングに適さない場合がある。
【００４５】
さらに、発光層の形成材料としては、少なくとも１種の蛍光色素を含むのが好ましい。これにより、発光層の発光特性を変化させることができ、例えば、発光層の発光効率の向上、または光吸収極大波長（発光色）を変えるための手段としても有効である。すなわち、蛍光色素は単に発光層材料としてではなく、発光機能そのものを担う色素材料として利用することができる。例えば、共役系高分子有機化合物分子上のキャリア再結合で生成したエキシトンのエネルギーをほとんど蛍光色素分子上に移すことができる。この場合、発光は蛍光量子効率が高い蛍光色素分子からのみ起こるため、発光層の電流量子効率も増加する。したがって、発光層の形成材料中に蛍光色素を加えることにより、同時に発光層の発光スペクトルも蛍光分子のものとなるので、発光色を変えるための手段としても有効となる。
【００４６】
なお、ここでいう電流量子効率とは、発光機能に基づいて発光性能を考察するための尺度であって、下記式により定義される。
ηE ＝放出されるフォトンのエネルギー／入力電気エネルギー
そして、蛍光色素のドープによる光吸収極大波長の変換によって、例えば赤、青、緑の３原色を発光させることができ、その結果フルカラー表示体を得ることが可能となる。
さらに蛍光色素をドーピングすることにより、ＥＬ素子の発光効率を大幅に向上させることができる。
【００４７】
蛍光色素としては、赤色の発色光を発光する発光層を形成する場合、赤色の発色光を有するローダミンまたはローダミン誘導体を用いるのが好ましい。これらの蛍光色素は、低分子であるため水溶液に可溶であり、またＰＰＶと相溶性がよく、均一で安定した発光層の形成が容易である。このような蛍光色素として具体的には、ローダミンＢ、ローダミンＢベース、ローダミン６Ｇ、ローダミン１０１過塩素酸塩等が挙げられ、これらを２種以上混合したものであってもよい。
【００４８】
また、緑色の発色光を発光する発光層を形成する場合、緑色の発色光を有するキナクリドンおよびその誘導体を用いるのが好ましい。これらの蛍光色素は前記赤色蛍光色素と同様、低分子であるため水溶液に可溶であり、またＰＰＶと相溶性がよく発光層の形成が容易である。
【００４９】
さらに、青色の発色光を発光する発光層を形成する場合、青色の発色光を有するジスチリルビフェニルおよびその誘導体を用いるのが好ましい。これらの蛍光色素は前記赤色蛍光色素と同様、低分子であるため水・アルコール混合溶液に可溶であり、またＰＰＶと相溶性がよく発光層の形成が容易である。
【００５０】
また、青色の発色光を有する他の蛍光色素としては、クマリンおよびその誘導体を挙げることができる。これらの蛍光色素は、前記赤色蛍光色素と同様、低分子であるため水溶液に可溶であり、またＰＰＶと相溶性がよく発光層の形成が容易である。このような蛍光色素として具体的には、クマリン、クマリン−１、クマリン−６、クマリン−７、クマリン１２０、クマリン１３８、クマリン１５２、クマリン１５３、クマリン３１１、クマリン３１４、クマリン３３４、クマリン３３７、クマリン３４３等が挙げられる。
【００５１】
さらに、別の青色の発色光を有する蛍光色素としては、テトラフェニルブタジエン（ＴＰＢ）またはＴＰＢ誘導体を挙げることができる。これらの蛍光色素は、前記赤色蛍光色素等と同様、低分子であるため水溶液に可溶であり、またＰＰＶと相溶性がよく発光層の形成が容易である。
以上の蛍光色素については、各色ともに１種のみを用いてもよく、また２種以上を混合して用いてもよい。
【００５２】
これらの蛍光色素については、前記共役系高分子有機化合物の前駆体固型分に対し、０．５〜１０ｗｔ％添加するのが好ましく、１．０〜５．０ｗｔ％添加するのがより好ましい。蛍光色素の添加量が多過ぎると発光層の耐候性および耐久性の維持が困難となり、一方、添加量が少な過ぎると、前述したような蛍光色素を加えることによる効果が十分に得られないからである。
【００５３】
また、前記前駆体および蛍光色素については、極性溶媒に溶解または分散させてインクとし、このインクをインクジェットヘッド１０から吐出するのが好ましい。極性溶媒は、前記前駆体、蛍光色素等を容易に溶解または均一に分散させることができるため、インクジェットヘッド１０のノズル孔１８での発光層形成材料中の固型分が付着したり目詰りを起こすのを防止することができる。
【００５４】
このような極性溶媒として具体的には、水、メタノール、エタノール等の水と相溶性のあるアルコール、Ｎ，Ｎ−ジメチルホルムアミド（ＤＭＦ）、Ｎ−メチルピロリドン（ＮＭＰ）、ジメチルイミダゾリン（ＤＭＩ）、ジメチルスルホキシド（ＤＭＳＯ）等の有機溶媒または無機溶媒が挙げられ、これらの溶媒を２種以上適宜混合したものであってもよい。
【００５５】
さらに、前記形成材料中に湿潤剤を添加しておくのが好ましい。これにより、形成材料がインクジェットヘッド１０のノズル孔１８で乾燥・凝固することを有効に防止することができる。かかる湿潤剤としては、例えばグリセリン、ジエチレングリコール等の多価アルコールが挙げられ、これらを２種以上混合したものであってもよい。この湿潤剤の添加量としては、形成材料の全体量に対し、５〜２０ｗｔ％程度とするのが好ましい。
なお、その他の添加剤、被膜安定化材料を添加してもよく、例えば、安定剤、、粘度調整剤、老化防止剤、ｐＨ調整剤、防腐剤、樹脂エマルジョン、レベリング剤等を用いることができる。
【００５６】
このような発光層の形成材料１１４Ｂをインクジェットヘッド１０のノズル孔１８から吐出すると、形成材料１１４Ａは隔壁１５０内の正孔注入層１４０Ａ上に塗布される。
ここで、形成材料１１４Ａの吐出による発光層の形成は、赤色の発色光を発光する発光層の形成材料、緑色の発色光を発光する発光層の形成材料、青色の発色光を発光する発光層の形成材料を、それぞれ対応する画素１Ａに吐出し塗布することによって行う。なお、各色に対応する画素１Ａは、これらが規則的な配置となるように予め決められている。
【００５７】
各色の発光層形成のための、形成材料の吐出例について、図７（ａ）〜（ｃ）を参照して説明する。
この例では、前述したように予め前記の正孔注入層１４０Ａが、図７（ｂ）に示すように透明基板１２１のＸ方向、すなわち図７（ｂ）中の矢印に示す方向にインクジェットヘッド１０と透明基板１２１とが相対的に移動させられたことにより、全ての画素１Ａに形成されているものとする。なお、インクジェットヘッド１０にはノズル孔１８が、Ｘ方向と略直交する方向、すなわちＹ方向に配列されており、したがってＸ方向に並列している各画素列は、それぞれインクジェットヘッド１０のうちの対応する同じノズル孔１８から各画素１Ａ毎に断続的なインクの吐出がなされることにより、正孔注入層１４０Ａを形成したものとなっている。
【００５８】
このようにして正孔注入層１４０Ａが形成された各画素１Ａに、前述したようにして発光層の形成材料を吐出し塗布するが、その際、本発明では、前記発光層形成材料のうちの一つの色（本例では緑色）の発光層形成材料を、正孔注入層１４０Ａの場合と同様にＸ方向に断続的に吐出し塗布する。
また、残りの赤色及び青色の発光層形成材料については、Ｘ方向と略直交するＹ方向に断続的に吐出し塗布する。
【００５９】
すなわち、まず図７（ａ）に示すように透明基板１２１のＹ方向に、赤色の発光層の形成材料を断続的に吐出し、Ｙ方向に配列された画素１Ａのうち予め赤色の発光層を形成するように設定されている画素（Ｒ１、Ｒ２、Ｒ３）に形成材料を塗布する。ここで、インクジェットヘッド１０にはノズル孔１８が、Ｙ方向と略直交する方向、すなわちＸ方向に配列されており、したがってＹ方向に並列している各画素列は、それぞれインクジェットヘッド１０のうちの対応する同じノズル孔１８から各画素１Ａ毎に断続的なインクの吐出がなされることにより、赤色の発光層の形成材料が塗布されたものとなっている。なお、Ｙ方向に並列されたこれら画素列については、その複数の列（図７（ａ）では３列）がインクジェットヘッド１０による一回の走査により同時に形成されるようになっている。
【００６０】
また、この赤色発光層の形成材料の吐出については、前述した正孔注入層１４０Ａの形成材料の吐出（図７（ｂ）参照）に対して９０°傾いた方向で行うようにしているが、このような吐出方向の変更については、透明基板１２１を載置した基板ステージ（図示せず）を回転させるか、あるいはインクジェットヘッド１０を９０°回転させることによって行う。すなわち、これによって図７（ｂ）に示した正孔注入層の形成の際の状態から、図７（ａ）に示した赤色発光層形成の状態に移行させているのである。
【００６１】
このようにして赤色発光層の形成材料を塗布したら、続いて緑色発光層の形成材料を吐出するべく、再度基板ステージあるいはインクジェットヘッド１０を回転させて、図７（ｂ）に示したようにインクジェットヘッド１０をそのノズル孔１８の列が透明基板１２１のＹ方向となるように相対的位置関係をセットする。そして、この状態のもとで緑色の発光層形成材料を透明基板１２１のＸ方向に断続的に吐出し、Ｘ方向に配列された画素１Ａのうち予め緑色の発光層を形成するように設定されている画素（Ｇ１、Ｇ２、Ｇ３、Ｇ４）に形成材料を塗布する。ここで、Ｘ方向に配列された画素１Ａは、図７（ａ）に示したようなＹ方向に形成された画素列と異なり、列を構成する全ての画素１Ａが同一色の発光層を形成する画素とはなっておらず、複数個毎、本例では３個の画素毎に１個の緑色の発光層を形成する画素（Ｇ１、Ｇ２、Ｇ３、Ｇ４）となっている。したがって、インクジェットヘッド１０からの断続的な吐出を行う際には、先の赤色発光層形成の場合とは異なり、吐出間隔をその分長くして行う必要がある。
【００６２】
このようにして緑色発光層の形成材料を塗布したら、続いて青色発光層の形成材料を吐出するべく、基板ステージあるいはインクジェットヘッド１０を再度回転させて、図７（ｃ）に示したようにインクジェットヘッド１０をそのノズル孔１８の列が透明基板１２１のＸ方向となるようにセットする。そして、この状態のもとで青色の発光層形成材料を透明基板１２１のＸ方向に断続的に吐出し、Ｙ方向に配列された画素１Ａのうち予め青色の発光層を形成するように設定されている画素（Ｂ１、Ｂ２、Ｂ３）に形成材料を塗布する。
【００６３】
このようにして正孔注入層１４０Ａを形成し、さらに各色の発光層形成材料を吐出塗布すると、同じノズル孔１８からの吐出によりその吐出方向に形成された画素列は、発光層のうちの緑色の画素列と正孔注入層１４０Ａの画素列とが透明基板１２１のＸ方向に、また発光層のうちの赤色の画素列と青色の画素列とがＹ方向に形成されることになる。すると、Ｘ方向の列間で生じる発光むらとＹ方向の列間で生じる発光むらとが確率的に言って共に同程度に起こると考えられることから、正孔注入層１４０Ａと赤色、緑色、青色の全て色の発光層とを同一の吐出方向で形成し、したがって各色の発光度のむらが同一の方向に生じる場合に比べ、発光むらとして視認される方向がＸ方向とＹ方向に分散され、これにより発光むらの偏りが少なくなる。
【００６４】
このようにして各色の発光層形成材料を吐出し塗布したら、発光層形成材料１１４Ｂ中の溶媒を蒸発させることにより、図５（ｂ）に示すように正孔層注入層１４０Ａ上に固形の発光層１４０Ｂを形成し、これにより正孔層注入層１４０Ａと発光層１４０Ｂとからなる発光部１４０を得る。ここで、発光層形成材料１１４Ｂ中の溶媒の蒸発については、必要に応じて加熱あるいは減圧等の処理を行うが、発光層の形成材料は通常乾燥性が良好で速乾性であることから、特にこのような処理を行うことなく、したがって各色の発光層形成材料を順次吐出塗布することにより、その塗布順に各色の発光層１４０Ｂを形成することができる。
その後、図５（ｃ）に示すように、透明基板１２１の表面全体に、あるいはストライプ状に反射電極１５４を形成し、有機ＥＬ素子を得る。
【００６５】
このように、本例の有機ＥＬ素子の製造方法にあっては、発光層のうちの緑色の画素列と正孔注入層１４０Ａの画素列とを透明基板１２１のＸ方向に、また発光層のうちの赤色の画素列と青色の画素列とをＹ方向に形成しているので、正孔注入層１４０Ａと赤色、緑色、青色の全て色の発光層とを同一の吐出方向で形成し、したがって各色の発光度のむらが同一の方向に生じる場合に比べ、発光むらとして視認される方向をＸ方向とＹ方向に分散することができ、これにより発光むらの偏りを少なくして全体としての表示品質の低下を軽減し、これの向上を図ることができる。
【００６６】
また、透明基板１２１上に予め隔壁１５０を形成しておき、該隔壁１５０内に正孔注入層の形成材料や発光層の形成材料を吐出し塗布しているので、吐出した際、各材料の着弾位置に少々バラツキがあっても、隔壁１５０内に着弾すれば所望の位置に発光層等を形成することができ、したがって発光層等からなる画素をそれぞれ所望位置に形成することにより、表示品質を高めることができる。
【００６７】
また、このようにして得られた有機ＥＬ素子にあっては、前記の製造方法によって得られてなることにより発光むらの偏りが少ないものとなることから、全体としての表示品質の低下が軽減され、表示品質の向上されたものとなる。
さらに、この有機ＥＬ素子を用いてなるＥＬディスプレイにあっても、高い表示品質を有するものとなる。
【００６８】
次に、本発明の有機ＥＬ素子の製造方法の他の例について説明する。
この例が先の例と異なるところは、インクジェット法で正孔注入層１４０Ａ及び発光層１４０Ｂを形成する際に、単一の画素に対する各形成材料の吐出を、単一のノズル孔１８からでなく、複数のノズル孔１８から行う点にある。
すなわち、本例では、図８（ａ）〜（ｃ）に示すように、一列に配列されたノズル孔１８間の間隔が図７（ａ）〜（ｃ）に示したものに比べ狭いインクジェットヘッド１０Ａを用意し、これを用いて正孔注入層１４０Ａ及び発光層１４０Ｂの形成材料を吐出するようにしている。
【００６９】
このインクジェットヘッド１０Ａによって正孔注入層１４０Ａ及び発光層１４０Ｂを形成するには、まず、図８（ｂ）に示すようにインクジェットヘッド１０Ａを、そのノズル孔１８の列が透明基板１２１のＹ方向となるようにセットし、その状態から図８（ｂ）中の矢印に示す方向にインクジェットヘッド１０Ａと透明基板１２１とをＸ方向に相対的に移動させ、これによって全ての画素１Ａに正孔注入層の形成材料を吐出し塗布する。このとき、インクジェットヘッド１０Ａは前述したようにノズル孔１８間の間隔が狭いことにより、単一の画素１Ａに対する正孔注入層形成材料の吐出が、単一のノズル孔１８からでなく、複数のノズル孔１８（本例では二つのノズル孔１８）から同時になされる。そして、先の例と同様にして塗布した形成材料から正孔注入層１４０Ａを形成する。
【００７０】
このように、単一のノズル孔１８からでなく複数のノズル孔１８から単一の画素１Ａに対して同時に吐出を行うことにより、この画素１Ａに吐出された形成材料の量は、ここへの吐出を行った複数のノズル孔１８間のバラツキが平均化された量となる。したがって、単一の正孔注入層１４０Ａを形成するノズル孔１８のグループ毎で比較した場合に、そのグループ間での吐出量のバラツキも平均化されることになる。
【００７１】
このようにして正孔注入層１４０Ａを形成したら、先の例と同様にして発光層の形成材料を吐出し塗布する。
すなわち、まず図８（ａ）に示すように透明基板１２１のＹ方向に、赤色の発光層の形成材料を断続的に吐出し、Ｙ方向に配列された画素１Ａのうち予め赤色の発光層を形成するように設定されている画素（Ｒ１、Ｒ２、Ｒ３）に形成材料を塗布する。この場合にも、正孔注入層の形成材料の場合と同様に、単一の画素１Ａに対する赤色発光層形成材料の吐出を、単一のノズル孔１８からでなく複数のノズル孔１８（本例では二つのノズル孔１８）から同時に行う。なお、Ｙ方向に並列されたこれら画素列については、先の例と同様に、その複数の列（図８（ａ）では３列）がインクジェットヘッド１０Ａによる一回の走査により同時に形成されるようになっている。
【００７２】
このようにして赤色発光層の形成材料を塗布したら、続いて緑色発光層の形成材料を吐出するべく、図８（ｂ）に示したようにインクジェットヘッド１０Ａをそのノズル孔１８の列が透明基板１２１のＹ方向となるようにセットする。そして、この状態のもとで先の例と同様にして緑色の発光層形成材料を透明基板１２１のＸ方向に断続的に吐出し、Ｘ方向に配列された画素１Ａのうち予め緑色の発光層を形成するように設定されている画素（Ｇ１、Ｇ２、Ｇ３、Ｇ４）に形成材料を塗布する。この場合にも、赤色発光層の形成材料の場合と同様に、単一の画素１Ａに対する緑色発光層形成材料の吐出を、単一のノズル孔１８からでなく複数のノズル孔１８（本例では二つのノズル孔１８）から同時に行う。なお、インクジェットヘッド１０からの断続的な吐出を行う際には、先の例と同様に、赤色発光層形成の場合よりその吐出間隔を長くして行う。
【００７３】
このようにして緑色発光層の形成材料を塗布したら、続いて青色発光層の形成材料を吐出するべく、図８（ｃ）に示したようにインクジェットヘッド１０Ａをそのノズル孔１８の列が透明基板１２１のＸ方向となるようにセットする。そして、この状態のもとで青色の発光層形成材料を透明基板１２１のＸ方向に断続的に吐出し、Ｙ方向に配列された画素１Ａのうち予め青色の発光層を形成するように設定されている画素（Ｂ１、Ｂ２、Ｂ３）に形成材料を塗布する。この場合にも、赤色発光層の形成材料の場合と同様に、単一の画素１Ａに対する青色発光層形成材料の吐出を、単一のノズル孔１８からでなく複数のノズル孔１８（本例では二つのノズル孔１８）から同時に行う。
【００７４】
このような発光層形成材料の吐出に際しても、単一のノズル孔１８からでなく複数のノズル孔１８から単一の画素１Ａに対して同時に吐出を行うことにより、この画素１Ａに吐出された形成材料の量を、ここへの吐出を行った複数のノズル孔１８間のバラツキが平均化された量とすることができる。したがって、単一の正孔注入層１４０Ａを形成するノズル孔１８のグループ毎で比較した場合に、そのグループ間での吐出量のバラツキも平均化されることになる。
【００７５】
そして、このように正孔注入層１４０Ａ及び各色の発光層１４０Ｂについて、いずれも単一の画素１Ａに対して複数のノズル孔１８から同時に吐出するようにしているので、ノズル孔１８のグループ間での吐出量のバラツキも平均化されることにより、全体としての表示品質の向上を図ることができる。
また、発光層のうちの緑色の画素列と正孔注入層１４０Ａの画素列とを透明基板１２１のＸ方向に、また発光層のうちの赤色の画素列と青色の画素列とをＹ方向に形成しているので、正孔注入層１４０Ａと赤色、緑色、青色の全て色の発光層とを同一の吐出方向で形成し、したがって各色の発光度のむらが同一の方向に生じる場合に比べ、発光むらとして視認される方向をＸ方向とＹ方向に分散することができ、これにより発光むらの偏りを少なくして全体としての表示品質の低下を軽減し、これの向上を図ることができる。
【００７６】
なお、図８（ａ）〜（ｃ）に示した例のごとく、単一の画素に対して複数のノズル孔１８から吐出を行う場合、図９に示すようにインクジェットヘッド１０Ａを、正孔注入層や発光層を形成する画素１Ａの列方向に対して所定量（例えば図９中の角度θ）傾けた状態で吐出するようにしてもよい。このようにしてインクジェットヘッド１０Ａを所定量傾け、ノズル孔１８の配列方向と移動方向（例えばＸ軸方向）との傾きを角度θとすれば、ノズル孔１８間の実際のピッチＤよりも見かけ上のピッチＥを狭くすることができ、これにより単一の画素１Ａに対して複数のノズル孔１８から略同時に吐出を行わせることができるようになる。
このようにしてノズル孔１８間の見かけ上の間隔を狭くするようにすれば、単一の画素１Ａに対して吐出するノズル孔１８の数を増やすことができ、したがって前述したようにノズル孔１８のグループ間での吐出量のバラツキをより平均化して、発光むらを一層少なくすることができる。
【００７７】
また、前記例では、画素１Ａ…の配列を図１０（ａ）に示すようにストライプ状としたが、図１０（ｂ）に示すようなモザイク状の配列や、図１０（ｃ）に示すようなデルタ状の配列などにおいても、同様の効果を得ることができる。
また、前記例では発光層１４０Ｂの下層として正孔注入層１４０Ａを形成したが、本発明はこれに限定されることなく、例えばこの正孔注入層に代えて正孔輸送層を形成するようにしてもよい。この正孔輸送層の形成材料としては特に限定されないものの、例えばピラゾリン誘導体、アリールアミン誘導体、スチルベン誘導体、トリフェニルジアミン誘導体等が用いられる。
【００７８】
また、前記例では画素１Ａ間を隔てる隔壁１５０を、ポリイミド材料とその表面を撥インク処理することによって形成したが、本発明はこれに限定されることなく、例えば樹脂ブラックレジストなどによって隔壁を形成してもよく、さらには隔壁を設けることなく正孔注入層や発光層を形成するようにしてもよい。
【００７９】
次に、前記例の有機ＥＬ素子を用いたＥＬディスプレイが備えられた電子機器の具体例について説明する。
図１１（ａ）は、携帯電話の一例を示した斜視図である。図１１（ａ）において、５００は携帯電話本体を示し、５０１は図１、図２に示したＥＬディスプレイを備えたＥＬ表示部（表示手段）を示している。
図１１（ｂ）は、ワープロ、パソコンなどの携帯型情報処理装置の一例を示した斜視図である。図１１（ｂ）において、６００は情報処理装置、６０１はキーボードなどの入力部、６０３は情報処理本体、６０２は前記の図１、図２に示したＥＬディスプレイを備えたＥＬ表示部（表示手段）を示している。
図１１（ｃ）は、腕時計型電子機器の一例を示した斜視図である。図１１（ｃ）において、７００は時計本体を示し、７０１は前記の図１、図２に示したＥＬディスプレイを備えたＥＬ表示部（表示手段）を示している。
図１１（ａ）〜（ｃ）に示す電子機器は、前記ＥＬディスプレイが備えられたものであるので、優れた表示品質が得られる表示手段を備えた電子機器となる。
【００８０】
【発明の効果】
以上説明したように本発明の有機ＥＬ素子の製造方法によれば、発光層のうちの少なくとも一つの色の発光層を形成する発光材料を、ノズルから第１の方向（例えばＸ方向）に断続的に吐出して複数の発光層からなる発光層の列を形成し、発光層のうちの他の色の発光層を形成する発光材料を、ノズルから第１の方向と略直交する第２の方向（例えばＹ方向）に断続的に吐出して複数の発光層からなる発光層の列を形成するので、インクジェットヘッドのノズル間での吐出量のバラツキに起因して吐出方向に形成される発光層の列間での発光むらを、発光層のうちの少なくとも一つの色と他の色とで略直交する方向に生じさせることができ、したがって発光むらの方向を一方向に偏らせないことにより全体としての表示品質の低下を軽減し、これの向上を図ることができる。
【００８１】
本発明の有機ＥＬ素子によれば、前記の製造方法によって得られてなることにより、表示品質の高いものとなる。
本発明のＥＬディスプレイによれば、前記有機ＥＬ素子を用いてなることにより高い表示品質を有するものとなる。
本発明の電子機器によれば、前記ＥＬディスプレイを用いてなることにより高い表示品質を有するものとなる。
【図面の簡単な説明】
【図１】 本発明のＥＬディスプレイの配置部を示す回路図である。
【図２】 画素部の平面構造を示す拡大平面図である。
【図３】 （ａ）〜（ｅ）は本発明の有機ＥＬ素子の製造方法を工程順に説明するための要部側断面図である。
【図４】 （ａ）〜（ｃ）は図３に続く工程を順に説明するための要部側断面図である。
【図５】 （ａ）〜（ｃ）は図４に続く工程を順に説明するための要部側断面図である。
【図６】 インクジェットヘッドの概略構成を説明するための図であり、（ａ）は要部斜視図、（ｂ）は要部側断面図である。
【図７】 （ａ）〜（ｃ）はインクジェットヘッドのノズル孔から発光層の形成材料を吐出する工程の一例を順に説明するための模式図である。
【図８】 （ａ）〜（ｃ）はインクジェットヘッドのノズル孔から発光層の形成材料を吐出する工程の他の例を順に説明するための模式図である。
【図９】 インクジェットヘッドを所定量傾けた状態で吐出する例を説明するための模式図である。
【図１０】 画素の配列パターンを説明するための図であって、（ａ）はストライプ状のパターン、（ｂ）はモザイク状のパターン、（ｃ）はデルタ状のパターンを示す図である。
【図１１】 ＥＬディスプレイが備えられた電子機器の具体例を示す図であり、（ａ）は携帯電話に適用した場合の一例を示す斜視図、（ｂ）は情報処理装置に適用した場合の一例を示す斜視図、（ｃ）は腕時計型電子機器に適用した場合の一例を示す斜視図である。
【図１２】 インクジェットヘッドのノズル孔から発光層の形成材料を吐出する工程の従来の例を説明するための模式図である。
【符号の説明】
１Ａ…画素、１０、１０Ａ…インクジェットヘッド、
１８…ノズル孔（ノズル）、１２１…透明基板、１４０Ａ…正孔注入層、
１４０Ｂ…発光層、１５０…隔壁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic EL element that is an electroluminescent element used for a display, a display light source, and the like, a manufacturing method thereof, an EL display, and an electronic apparatus.
[0002]
[Prior art]
2. Description of the Related Art In recent years, development of organic EL (electroluminescence) elements using organic substances in a light emitting layer has been accelerated as a spontaneous emission type display replacing a liquid crystal display. As a process for forming a light emitting layer made of an organic substance in an organic EL element, Appl. Phys. Lett. 51 (12), 21 September 1987, page 913, a method of depositing a low molecular weight material by vapor deposition, and Appl. Phys. Lett. 71 (1), 7 July 1997, page 34, a method of applying a polymer material has been mainly developed.
[0003]
As a means for colorization, when a low molecular weight material is used, a method of evaporating and forming a light emitting material of a different light emission color over a desired pixel corresponding portion through a mask having a predetermined pattern is performed. On the other hand, when a polymer material is used, since it can be patterned finely and easily, colorization using an ink jet method has attracted attention. The production of an organic EL element by the ink jet method is disclosed in, for example, JP-A-7-235378, JP-A-10-12377, JP-A-11-40358, and JP-A-11-54270.
In addition, in an organic EL element, it has been proposed to form a hole injection layer or a hole transport layer between an anode and a light emitting layer in order to improve luminous efficiency and durability (Appl. Phys. Lett. 51, 21 September 1987, page 913).
[0004]
By the way, in an organic EL element in which a hole injection layer and a light emitting layer are formed by an ink jet method, each pixel usually has a width corresponding to one dot ejected from one nozzle of the ink jet head. . As such pixels, for example, as shown in FIG. 12, a pixel R whose emission color is red, a pixel G which is green, and a pixel B which is blue are arranged in the same direction, and the respective columns are defined. Thus, an organic EL element is formed by arranging a large number of them.
[0005]
In order to form such light emitting layers of the pixels R, G, and B by the ink jet method, the substrate or the ink jet head is moved to move the RGB from one nozzle hole N of the ink jet head H as shown in FIG. One row of pixels is discharged. Further, as a whole, a plurality of rows of pixels of the same color are formed from a plurality of nozzles N by one scan, and thereafter, pixels of other colors are formed in the same manner.
[0006]
[Problems to be solved by the invention]
However, a plurality of nozzles N provided in the inkjet head H may vary in discharge amount due to different ink supply paths depending on their positions. For example, there may be a difference in the discharge amount between the nozzle N1 that discharges to the row of pixels R1 in FIG. 12 and the nozzle N2 that discharges to the row of pixels R2.
[0007]
However, in that case, of course, a difference in the layer thickness occurs according to the difference in ejection amount between the light emitting layers to be formed, and this causes unevenness in the degree of light emission between the columns of the pixels R1 and R2. As a result, the display quality is impaired. In addition, since such a tendency naturally occurs in other colors, in the organic EL element formed by such a method, all colors are in the horizontal direction (X direction) of the substrate shown in FIG. Unevenness in the luminous intensity occurs between the columns, and the display quality deteriorates.
[0008]
The present invention has been made in view of the above circumstances, and an object of the present invention is to manufacture an organic EL element with reduced deterioration in display quality caused by variations in the discharge amount between nozzles of an inkjet head and its manufacture. It is to provide a method, an EL display, and an electronic device.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing an organic EL device according to the present invention includes forming a plurality of light emitting layers by ejecting a light emitting material from a nozzle of an inkjet head onto a substrate, and corresponding to each of the light emitting layers. A method of manufacturing an organic EL element in which pixels are formed vertically and horizontally, wherein a light emitting material for forming a light emitting layer of at least one of the light emitting layers is intermittently ejected from the nozzle in a first direction. A row of light-emitting layers composed of a plurality of light-emitting layers is formed, and a light-emitting material forming a light-emitting layer of another color among the light-emitting layers is intermittently provided from the nozzle in a second direction substantially orthogonal to the first direction. The method is characterized in that a row of light-emitting layers composed of a plurality of light-emitting layers is formed by ejecting the liquid.
[0010]
According to this method for manufacturing an organic EL device, a light emitting material that forms a light emitting layer of at least one of the light emitting layers is intermittently ejected from a nozzle in a first direction, and light emission comprising a plurality of light emitting layers. A plurality of light emitting layers are formed by intermittently discharging a light emitting material forming a light emitting layer of another color among the light emitting layers from a nozzle in a second direction substantially orthogonal to the first direction. As a result, the uneven light emission between the light emitting layer rows formed in the ejection direction due to the variation in the ejection amount between the nozzles of the inkjet head is caused by at least one of the light emitting layers. One color and the other can be generated in a direction substantially orthogonal to each other, and therefore the direction of uneven light emission is not biased in one direction, thereby reducing the overall display quality and improving this. Can do.
[0011]
Further, in the method for manufacturing the organic EL element, the light emitting layer is formed in three colors of red, green, and blue, and a hole injection layer or a hole transport layer is formed on each of the pixels forming the light emitting layer. When forming the above-described forming material by discharging from the nozzle of the inkjet head, one color of the light emitting layer and the hole injection layer or the hole transport layer are discharged in the first direction. Preferably, each row is formed, and each of the other two colors of the light emitting layer is formed by ejecting each material in the second direction.
In this way, one color column of the light emitting layer and the hole injection layer or hole transport layer column are in the first direction, and the other two color columns of the light emitting layer are Since it is formed in the second direction, it is considered that the light emission unevenness occurring between the columns in the first direction and the light emission unevenness occurring between the columns in the second direction occur at the same level in terms of probability. It is possible to further reduce the unevenness in the direction of light emission unevenness, reduce the deterioration of the display quality as a whole, and improve it.
[0012]
Further, in the method for manufacturing the organic EL element, a single light emitting layer corresponding to each pixel is formed by simultaneously emitting a light emitting material from a plurality of nozzles arranged substantially orthogonal to the column direction of the light emitting layer to be formed. It is preferably formed by discharging.
In this way, since a single light emitting layer is formed by discharging from a plurality of nozzles, when compared for each group of nozzles forming a single light emitting layer, variations in the discharge amount between the nozzles. However, the variation in the discharge amount between the groups of nozzles is averaged, so that unevenness in light emission between the rows of the light emitting layers is reduced, and therefore the display quality as a whole can be improved.
[0013]
In the method of manufacturing the organic EL element, a single hole injection layer or hole transport layer corresponding to each pixel is substantially orthogonal to the column direction of the hole injection layer or hole transport layer to be formed. The material is preferably discharged by discharging the material from a plurality of nozzles arranged almost simultaneously.
In this way, since a single hole injection layer or hole transport layer is formed by discharging from a plurality of nozzles, each group of nozzles forming a single hole injection layer or hole transport layer is formed. In comparison, the variation in the discharge amount between the nozzles is averaged between the groups of nozzles, resulting in unevenness in the layer thickness between the hole injection layers or the hole transport layer rows. Therefore, a decrease in display quality due to the unevenness of the layer thickness can be reduced.
[0014]
In the method of manufacturing the organic EL element, it is preferable that the nozzle row of the inkjet head is ejected in a state where it is inclined by a predetermined amount with respect to the row direction of the light emitting layer to be formed.
In this way, it is possible to increase the number of nozzles ejected to a single light emitting layer by narrowing the apparent interval between the nozzles. Therefore, as described above, ejection between groups of nozzles is possible. The variation in the amount can be further averaged to reduce unevenness in light emission.
[0015]
Further, in the method for producing the organic EL element, it is preferable that the nozzle row of the inkjet head is ejected in a state inclined by a predetermined amount with respect to the row direction of the hole injection layer or hole transport layer to be formed.
In this way, the number of nozzles ejected to a single hole injection layer or hole transport layer can be increased by narrowing the apparent spacing between nozzles, and as described above. It is possible to reduce unevenness in the layer thickness of the hole injection layer or the hole transport layer obtained by further averaging the variation in the discharge amount between the nozzle groups.
[0016]
Further, in the method for manufacturing the organic EL element, it is preferable that partition walls separating pixels are formed on the substrate in advance, and the light emitting material is discharged into the partition walls to form a light emitting layer.
In this way, even if there is a slight variation in the landing position of each material when ejected, a light emitting layer or the like can be formed at a desired position by landing in the partition wall. The display quality can be improved by forming each at a desired position.
Note that at least the top surface of the partition wall preferably has a contact angle of 30 ° or more with respect to the liquid material discharged from the inkjet head.
In this way, it is possible to prevent the light emitting layer or the like from flowing out to the adjacent pixel beyond the partition.
[0017]
The organic EL device of the present invention is obtained by the above-described manufacturing method.
According to this organic EL element, the display quality is high by being obtained by the manufacturing method described above.
[0018]
The EL display of the present invention is characterized by using the organic EL element.
According to this EL display, it has a high display quality by using the organic EL element.
[0019]
The electronic apparatus of the present invention is characterized in that the EL display is provided as a display means.
According to this electronic apparatus, high display quality is achieved by using the EL display.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
First, a schematic configuration of an EL display including the organic EL element of the present invention obtained by applying the manufacturing method of the present invention will be described.
1 and 2 show an example in which the EL display of the present invention is applied to an active matrix display. In these drawings, reference numeral 1 denotes an EL display.
[0021]
As shown in FIG. 1 which is a circuit diagram, the EL display 1 includes a plurality of scanning lines 131, a plurality of signal lines 132 extending in a direction intersecting with the scanning lines 131, and these on a transparent display substrate. A plurality of common power supply lines 133 extending in parallel to the signal lines 132 are respectively wired, and each pixel has a pixel (pixel area element) 1A at each intersection of the scanning lines 131 and the signal lines 132. It is.
[0022]
For the signal line 132, a data side driving circuit 3 including a shift register, a level shifter, a video line, and an analog switch is provided.
On the other hand, for the scanning line 131, a scanning side driving circuit 4 including a shift register and a level shifter is provided. Each pixel region 1A has a switching thin film transistor 142 to which a scanning signal is supplied to the gate electrode via the scanning line 131, and a holding for holding an image signal supplied from the signal line 132 via the switching thin film transistor 142. The capacitor cap, the current thin film transistor 143 to which the image signal held by the storage capacitor cap is supplied to the gate electrode, and the common power supply line 133 are driven when the current thin film transistor 143 is electrically connected to the common power supply line 133. A pixel electrode 141 into which a current flows and a light emitting unit 140 sandwiched between the pixel electrode 141 and the reflective electrode 154 are provided.
[0023]
Under such a configuration, when the scanning line 131 is driven and the switching thin film transistor 142 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor cap, and according to the state of the holding capacitor cap, The on / off state of the current thin film transistor 143 is determined. Then, a current flows from the common power supply line 133 to the pixel electrode 141 through the channel of the current thin film transistor 143, and further, a current flows to the reflective electrode 154 through the light emitting unit 140, so that the light emitting unit 140 responds to the amount of current flowing therethrough. Will start to emit light.
[0024]
Here, the planar structure of each pixel 1A is an enlarged plan view in a state in which the reflective electrode and the organic EL element are removed, as shown in FIG. In this arrangement, the common power supply line 133, the scanning line 131, and other pixel electrode scanning lines (not shown) are surrounded.
[0025]
Next, a method for manufacturing an organic EL element provided in such an EL display 1 will be described with reference to FIGS. 3 to 5, only the single pixel 1 </ b> A is illustrated for simplifying the description.
First, a substrate is prepared. Here, in the organic EL element, light emitted from a light emitting layer to be described later can be extracted from the substrate side, and can be configured to be extracted from the side opposite to the substrate. In the case where the emitted light is extracted from the substrate side, transparent or translucent materials such as glass, quartz, and resin are used as the substrate material, but particularly inexpensive soda glass is preferably used. When soda glass is used, it is preferable to apply silica coating to the soda glass because it has an effect of protecting the soda glass that is weak against acid-alkali and further has an effect of improving the flatness of the substrate.
Alternatively, a color filter film, a color conversion film containing a fluorescent material, or a dielectric reflection film may be disposed on the substrate to control the emission color.
Further, in the case of a configuration in which emitted light is extracted from the side opposite to the substrate, the substrate may be opaque. In that case, a ceramic sheet such as alumina, a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation, A curable resin, a thermoplastic resin, or the like can be used.
[0026]
In this example, a transparent substrate 121 made of soda glass or the like is prepared as a substrate as shown in FIG. In response to this, a base protective film (not shown) made of a silicon oxide film having a thickness of about 200 to 500 nm is formed by plasma CVD using TEOS (tetraethoxysilane), oxygen gas, or the like as a raw material as necessary. .
[0027]
Next, the temperature of the transparent substrate 121 is set to about 350 ° C., and the semiconductor film 200 made of an amorphous silicon film having a thickness of about 30 to 70 nm is formed on the surface of the base protective film by plasma CVD. Next, a crystallization process such as laser annealing or solid phase growth is performed on the semiconductor film 200 to crystallize the semiconductor film 200 into a polysilicon film. In the laser annealing method, for example, a line beam having a beam length of 400 mm is used with an excimer laser, and the output intensity thereof is, for example, 200 mJ / cm. ² And With respect to the line beam, the line beam is scanned so that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps each region.
[0028]
Next, as shown in FIG. 3B, the semiconductor film (polysilicon film) 200 is patterned into an island-shaped semiconductor film 210, and the surface thereof is formed by plasma CVD using TEOS, oxygen gas, or the like as a raw material. A gate insulating film 220 made of a silicon oxide film or a nitride film having a thickness of about 60 to 150 nm is formed. The semiconductor film 210 serves as the channel region and the source / drain region of the current thin film transistor 143 shown in FIG. 2, but the semiconductor film serves as the channel region and the source / drain region of the switching thin film transistor 142 at different cross-sectional positions. Is also formed. That is, in the manufacturing process shown in FIGS. 3 to 5, two types of transistors 142 and 143 are formed at the same time, but since they are manufactured in the same procedure, only the current thin film transistor 143 will be described in the following description. The description of the switching thin film transistor 142 is omitted.
[0029]
Next, as shown in FIG. 3C, a conductive film made of a metal film such as aluminum, tantalum, molybdenum, titanium, or tungsten is formed by sputtering, and then patterned to form a gate electrode 143A.
Next, high-concentration phosphorus ions are implanted in this state, and source / drain regions 143a and 143b are formed in the semiconductor film 210 in a self-aligned manner with respect to the gate electrode 143A. Note that a portion where impurities are not introduced becomes a channel region 143c.
[0030]
Next, as illustrated in FIG. 3D, after forming the interlayer insulating film 230, contact holes 232 and 234 are formed, and the relay electrodes 236 and 238 are embedded in the contact holes 232 and 234.
Next, as illustrated in FIG. 3E, the signal line 132, the common power supply line 133, and the scanning line (not illustrated in FIG. 3) are formed on the interlayer insulating film 230. Here, the relay electrode 238 and each wiring may be formed in the same process. At this time, the relay electrode 236 is formed of an ITO film described later.
[0031]
Then, an interlayer insulating film 240 is formed so as to cover the upper surface of each wiring, a contact hole (not shown) is formed at a position corresponding to the relay electrode 236, and the ITO film is embedded in the contact hole. In addition, the ITO film is patterned and a pixel electrode electrically connected to the source / drain region 143a at a predetermined position surrounded by the signal line 132, the common power supply line 133, and the scanning line (not shown). 141 is formed. Here, a portion sandwiched between the signal line 132, the common power supply line 133, and further the scanning line (not shown) is a place where a hole injection layer and a light emitting layer are formed as described later.
[0032]
Next, as shown in FIG. 4A, a partition wall 150 is formed so as to surround the formation place. The partition 150 functions as a partition member, and is preferably formed of an insulating organic material such as polyimide. About the film thickness of the partition 150, it forms so that it may become the height of 1-2 micrometers, for example. Further, the partition 150 is preferably one that exhibits ink repellency with respect to the liquid ejected from the inkjet head 10. Specifically, the contact angle of the ink (liquid ejected from the inkjet head 10) with respect to the partition 150 is high. It is preferable that the angle is 30 ° or more.
In order to develop ink repellency in the partition wall 150, for example, a method of surface-treating the surface of the partition wall 150 with a fluorine-based compound or the like is employed. Examples of fluorine compounds include CF _Four , SF _Five , CHF _Three Examples of the surface treatment include plasma treatment and UV irradiation treatment.
Under such a configuration, a sufficiently high step 111 is formed between the formation site of the hole injection layer and the light emitting layer, that is, between the application position of these forming materials and the surrounding partition wall 150. It is formed.
[0033]
Next, as shown in FIG. 4B, with the upper surface of the display substrate 121 facing upward, the material for forming the hole injection layer is applied by the inkjet head method so as to be surrounded by the partition 150 by the inkjet head method. Selectively apply to position.
Here, as shown in FIG. 6A, the inkjet head 10 includes a nozzle plate 12 made of, for example, stainless steel and a vibration plate 13, and both are joined via a partition member (reservoir plate) 14. A plurality of spaces 15 and a liquid reservoir 16 are formed between the nozzle plate 12 and the diaphragm 13 by the partition member 14. Each space 15 and the liquid reservoir 16 are filled with ink, and each space 15 and the liquid reservoir 16 communicate with each other via a supply port 17. A plurality of nozzle holes 18 for ejecting ink from the space 15 are formed in the nozzle plate 12 in a line. On the other hand, a hole 19 for supplying ink to the liquid reservoir 16 is formed in the vibration plate 13.
[0034]
Further, a piezoelectric element (piezo element) 20 is joined to the surface of the diaphragm 13 opposite to the surface facing the space 15 as shown in FIG. The piezoelectric element 20 is positioned between a pair of electrodes 21 and is configured to bend so that when it is energized, it projects outward. The diaphragm 13 to which the piezoelectric element 20 is bonded in such a configuration is bent integrally with the piezoelectric element 20 at the same time so that the volume of the space 15 is increased. It is going to increase. Therefore, ink corresponding to the increased volume in the space 15 flows from the liquid reservoir 16 through the supply port 17. Further, when energization to the piezoelectric element 20 is released from such a state, both the piezoelectric element 20 and the diaphragm 13 return to their original shapes. Accordingly, since the space 15 also returns to its original volume, the pressure of the ink inside the space 15 rises, and the ink droplet 22 is ejected from the nozzle hole 18 toward the substrate.
The ink jet system of the ink jet head 10 may be a system other than the piezo jet type using the piezoelectric element 20. For example, the ink is generated by utilizing thermal energy using an electrothermal transducer as an energy generating element. You may employ | adopt the system of the head etc. which discharge.
[0035]
Using the inkjet head 10 having such a configuration, in this example, as shown in FIG. 4B, a material for forming a hole injection layer is applied as an ink in the partition 150.
As a material for forming the hole injection layer, polyphenylene vinylene whose polymer precursor is polytetrahydrothiophenylphenylene, 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane, tris (8-hydroxyquinolinol) ) Aluminum and the like.
At this time, the liquid forming material 114A tends to spread in the horizontal direction because of its high fluidity. However, since the partition wall 150 is formed so as to surround the applied position, the forming material 114A passes over the partition wall 150 and has its wall. It is prevented from spreading outside.
[0036]
In addition, the formation of the hole injection layer by discharging the forming material 114A from the nozzle hole 18 of the ink jet head 10 is performed by pixels arranged in this direction along the X direction of the transparent substrate 121 as described later. This is done sequentially for each 1A. In addition, since the discharge of the material for forming the hole injection layer is basically performed for all the pixels, among the plurality of nozzle holes 18 arranged in the ink jet head 10, it corresponds to each pixel 1 </ b> A. All the nozzle holes 18 to be discharged are discharged substantially simultaneously.
[0037]
Next, as shown in FIG. 4C, the solvent of the liquid precursor 114 </ b> A is evaporated by heating or light irradiation to form a solid hole injection layer 140 </ b> A on the pixel electrode 141.
Next, as shown in FIG. 5A, with the upper surface of the display substrate 121 facing upward, the light emitting layer forming material (light emitting material) 114B is injected as an ink from the inkjet head 10 into the holes 150. Selectively apply on layer 140A.
[0038]
As a material for forming the light emitting layer, for example, a material containing a precursor of a conjugated polymer organic compound and a fluorescent dye for changing the light emitting characteristics of the light emitting layer to be obtained is preferably used.
The precursor of the conjugated polymer organic compound is ejected from the inkjet head 10 together with a fluorescent dye or the like and formed into a thin film, and then, for example, is heated and cured as shown in the following formula (I), thereby conjugated polymer This refers to a material capable of generating a light emitting layer to be an organic EL layer. For example, in the case of a sulfonium salt of a precursor, a sulfonium group is eliminated by heat treatment and becomes a conjugated polymer organic compound.
[0039]
[Chemical 1]

[0040]
Such a conjugated polymer organic compound is solid and has strong fluorescence, and can form a homogeneous solid ultrathin film. In addition, it has high forming ability and high adhesion to the ITO electrode. Furthermore, since the precursor of such a compound forms a strong conjugated polymer film after curing, the precursor solution is adjusted to a desired viscosity applicable to inkjet patterning described later before heat curing. It is possible to form a film under optimum conditions in a simple and short time.
[0041]
As such a precursor, for example, a precursor of PPV (poly (para-phenylene vinylene)) or a derivative thereof is preferable. A precursor of PPV or a derivative thereof is soluble in water or an organic solvent, and can be polymerized, so that a high-quality thin film can be obtained optically. Furthermore, since PPV has strong fluorescence and is also a conductive polymer in which double bond π electrons are non-polarized on the polymer chain, a high-performance organic EL device can be obtained.
[0042]
Examples of precursors of such PPV or PPV derivatives include PPV (poly (para-phenylene vinylene)) precursors, MO-PPV (poly (2,5-dimethoxy-1,4), as shown in chemical formula (II), for example. -Phenylene vinylene)) precursor, CN-PPV (poly (2,5-bishexyloxy-1,4-phenylene- (1-cyanovinylene))) precursor, MEH-PPV (poly [2-methoxy-5- (2′-ethylhexyloxy)]-para-phenylene vinylene) precursor and the like.
[0043]
[Chemical 2]

[0044]
The precursor of the PPV or PPV derivative is soluble in water as described above, and is polymerized by heating after film formation to form a PPV layer. The content of the precursor typified by the PPV precursor is preferably 0.01 to 10.0 wt%, more preferably 0.1 to 5.0 wt% with respect to the entire composition. If the amount of the precursor added is too small, it is insufficient to form a conjugated polymer film. If the amount is too large, the composition has a high viscosity and may not be suitable for highly accurate patterning by the ink jet method.
[0045]
Furthermore, it is preferable that the light emitting layer forming material contains at least one fluorescent dye. Thereby, the light emission characteristics of the light emitting layer can be changed. For example, it is effective as a means for improving the light emission efficiency of the light emitting layer or changing the light absorption maximum wavelength (light emission color). That is, the fluorescent dye can be used not only as a light emitting layer material but also as a dye material having a light emitting function itself. For example, most of the exciton energy generated by carrier recombination on the conjugated macromolecular organic compound molecule can be transferred onto the fluorescent dye molecule. In this case, since light emission occurs only from fluorescent dye molecules having high fluorescence quantum efficiency, the current quantum efficiency of the light emitting layer is also increased. Therefore, by adding a fluorescent dye to the material for forming the light emitting layer, the emission spectrum of the light emitting layer simultaneously becomes that of the fluorescent molecule, which is effective as a means for changing the emission color.
[0046]
The current quantum efficiency here is a scale for considering the light emission performance based on the light emission function, and is defined by the following equation.
ηE = emitted photon energy / input electric energy
Then, by converting the light absorption maximum wavelength by doping the fluorescent dye, for example, three primary colors of red, blue, and green can be emitted, and as a result, a full color display can be obtained.
Furthermore, the luminous efficiency of the EL element can be greatly improved by doping with a fluorescent dye.
[0047]
As the fluorescent dye, when forming a light emitting layer that emits red colored light, it is preferable to use rhodamine or a rhodamine derivative having red colored light. Since these fluorescent dyes are low in molecular weight, they are soluble in an aqueous solution, have good compatibility with PPV, and can easily form a uniform and stable light emitting layer. Specific examples of such fluorescent dyes include rhodamine B, rhodamine B base, rhodamine 6G, rhodamine 101 perchlorate and the like, and a mixture of two or more thereof may be used.
[0048]
Moreover, when forming the light emitting layer which emits green colored light, it is preferable to use quinacridone and its derivatives having green colored light. These fluorescent dyes, like the red fluorescent dyes, are low in molecular weight and therefore soluble in aqueous solutions, and are compatible with PPV and can easily form a light emitting layer.
[0049]
Furthermore, when forming a light emitting layer that emits blue colored light, it is preferable to use distyrylbiphenyl having a blue colored light and derivatives thereof. These fluorescent dyes, like the red fluorescent dyes, are low in molecular weight and therefore are soluble in a water / alcohol mixed solution, and have good compatibility with PPV and facilitate the formation of a light emitting layer.
[0050]
In addition, examples of other fluorescent dyes having blue colored light include coumarin and derivatives thereof. These fluorescent dyes, like the above-mentioned red fluorescent dyes, are low in molecular weight and therefore are soluble in aqueous solutions, and have good compatibility with PPV and facilitate the formation of a light emitting layer. Specific examples of such fluorescent dyes include coumarin, coumarin-1, coumarin-6, coumarin-7, coumarin 120, coumarin 138, coumarin 152, coumarin 153, coumarin 311, coumarin 314, coumarin 334, coumarin 337, coumarin. 343 or the like.
[0051]
Furthermore, examples of the fluorescent dye having a blue colored light include tetraphenylbutadiene (TPB) and TPB derivatives. These fluorescent dyes, like the above-mentioned red fluorescent dyes, are low in molecular weight and are therefore soluble in aqueous solutions, and are compatible with PPV and can easily form a light emitting layer.
About the above fluorescent dye, only 1 type may be used for each color, and 2 or more types may be mixed and used for it.
[0052]
These fluorescent dyes are preferably added in an amount of 0.5 to 10 wt%, more preferably 1.0 to 5.0 wt%, based on the solid precursor of the conjugated polymer organic compound. If the amount of fluorescent dye added is too large, it will be difficult to maintain the weather resistance and durability of the light-emitting layer. On the other hand, if the amount added is too small, the effects of adding the fluorescent dye as described above cannot be obtained sufficiently. It is.
[0053]
The precursor and the fluorescent dye are preferably dissolved or dispersed in a polar solvent to form an ink, and this ink is preferably ejected from the inkjet head 10. Since the polar solvent can easily dissolve or uniformly disperse the precursor, the fluorescent dye, and the like, the solid component in the light emitting layer forming material in the nozzle hole 18 of the inkjet head 10 is attached or clogged. It can be prevented from waking up.
[0054]
Specific examples of such a polar solvent include water, alcohols compatible with water such as methanol and ethanol, N, N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethylimidazoline (DMI), An organic solvent or an inorganic solvent such as dimethyl sulfoxide (DMSO) may be used, and two or more of these solvents may be appropriately mixed.
[0055]
Furthermore, it is preferable to add a wetting agent to the forming material. Thereby, it can prevent effectively that a forming material dries and solidifies in the nozzle hole 18 of the inkjet head 10. FIG. Examples of the wetting agent include polyhydric alcohols such as glycerin and diethylene glycol, and a mixture of two or more of these may be used. The amount of the wetting agent added is preferably about 5 to 20 wt% with respect to the total amount of the forming material.
Other additives and film stabilizing materials may be added. For example, a stabilizer, a viscosity modifier, an anti-aging agent, a pH adjuster, an antiseptic, a resin emulsion, a leveling agent and the like can be used. .
[0056]
When such a light emitting layer forming material 114 </ b> B is discharged from the nozzle hole 18 of the inkjet head 10, the forming material 114 </ b> A is applied onto the hole injection layer 140 </ b> A in the partition wall 150.
Here, the formation of the light emitting layer by discharging the forming material 114A includes the formation material of the light emitting layer that emits red colored light, the material of the light emitting layer that emits green colored light, and the light emitting layer that emits blue colored light. The forming material is discharged and applied to the corresponding pixel 1A. The pixels 1A corresponding to the respective colors are determined in advance so that they are regularly arranged.
[0057]
An example of discharging the forming material for forming the light emitting layer of each color will be described with reference to FIGS.
In this example, as described above, the hole injection layer 140A is previously placed in the X direction of the transparent substrate 121 as shown in FIG. 7B, that is, in the direction indicated by the arrow in FIG. And the transparent substrate 121 are relatively moved, and are formed in all the pixels 1A. In addition, the nozzle holes 18 are arranged in the inkjet head 10 in a direction substantially orthogonal to the X direction, that is, in the Y direction, so that each pixel column arranged in parallel in the X direction corresponds to the corresponding one in the inkjet head 10. The hole injection layer 140A is formed by intermittently discharging ink from the same nozzle hole 18 for each pixel 1A.
[0058]
As described above, the light emitting layer forming material is discharged and applied to each pixel 1A on which the hole injection layer 140A is formed in this manner. In this case, in the present invention, among the light emitting layer forming materials, The light emitting layer forming material of one color (green in this example) is intermittently ejected and applied in the X direction as in the case of the hole injection layer 140A.
Further, the remaining red and blue light emitting layer forming materials are intermittently discharged and applied in the Y direction substantially orthogonal to the X direction.
[0059]
That is, first, as shown in FIG. 7A, the red light emitting layer forming material is intermittently ejected in the Y direction of the transparent substrate 121, and the red light emitting layer is preliminarily disposed among the pixels 1A arranged in the Y direction. A forming material is applied to the pixels (R1, R2, R3) set to be formed. Here, the nozzle holes 18 are arranged in the ink jet head 10 in a direction substantially orthogonal to the Y direction, that is, in the X direction. By intermittently discharging ink from the corresponding nozzle hole 18 for each pixel 1A, a red light emitting layer forming material is applied. For these pixel columns arranged in parallel in the Y direction, a plurality of columns (three columns in FIG. 7A) are simultaneously formed by a single scan by the inkjet head 10.
[0060]
Further, the discharge of the material for forming the red light emitting layer is performed in a direction inclined by 90 ° with respect to the discharge of the material for forming the hole injection layer 140A (see FIG. 7B). Such a change in the ejection direction is performed by rotating a substrate stage (not shown) on which the transparent substrate 121 is placed, or by rotating the inkjet head 10 by 90 °. That is, this shifts the state of forming the hole injection layer shown in FIG. 7B to the state of forming the red light emitting layer shown in FIG. 7A.
[0061]
After the red light emitting layer forming material is applied in this way, the substrate stage or the ink jet head 10 is rotated again to discharge the green light emitting layer forming material, and the ink jet ink as shown in FIG. The relative positional relationship of the head 10 is set so that the row of the nozzle holes 18 is in the Y direction of the transparent substrate 121. In this state, the green light emitting layer forming material is intermittently ejected in the X direction of the transparent substrate 121 so that the green light emitting layer is formed in advance among the pixels 1A arranged in the X direction. A forming material is applied to the pixels (G1, G2, G3, G4). Here, the pixels 1A arranged in the X direction are different from the pixel columns formed in the Y direction as shown in FIG. 7A, and all the pixels 1A constituting the columns form a light emitting layer of the same color. It is not a pixel to be used, but is a pixel (G 1, G 2, G 3, G 4) that forms one green light emitting layer for every plurality, in this example, for every three pixels. Therefore, when intermittent discharge from the inkjet head 10 is performed, it is necessary to increase the discharge interval accordingly, unlike the case of forming the red light emitting layer.
[0062]
After the green light emitting layer forming material is applied in this way, the substrate stage or the ink jet head 10 is rotated again in order to discharge the blue light emitting layer forming material, and the ink jet as shown in FIG. The head 10 is set so that the row of the nozzle holes 18 is in the X direction of the transparent substrate 121. In this state, the blue light emitting layer forming material is intermittently ejected in the X direction of the transparent substrate 121 so that the blue light emitting layer is formed in advance among the pixels 1A arranged in the Y direction. A forming material is applied to the pixels (B1, B2, B3).
[0063]
When the hole injection layer 140A is formed in this way, and the light emitting layer forming material of each color is further discharged and applied, the pixel column formed in the discharge direction by the discharge from the same nozzle hole 18 is the green of the light emitting layer. And the pixel column of the hole injection layer 140A are formed in the X direction of the transparent substrate 121, and the red pixel column and the blue pixel column of the light emitting layer are formed in the Y direction. Then, since it is considered that the light emission unevenness generated between the columns in the X direction and the light emission unevenness generated between the columns in the Y direction occur at the same level in terms of probability, the hole injection layer 140A and red, green, blue The light emitting layers of all the colors are formed in the same ejection direction, and therefore, the direction in which the unevenness of light emission of each color is generated in the same direction is dispersed in the X direction and the Y direction. As a result, unevenness in the emission unevenness is reduced.
[0064]
When the light emitting layer forming material of each color is discharged and applied in this way, the solvent in the light emitting layer forming material 114B is evaporated, and solid light emission is formed on the hole layer injection layer 140A as shown in FIG. The layer 140B is formed, whereby the light emitting portion 140 including the hole layer injection layer 140A and the light emitting layer 140B is obtained. Here, with respect to the evaporation of the solvent in the light emitting layer forming material 114B, treatment such as heating or decompression is performed as necessary. However, the light emitting layer forming material usually has good drying properties and is quick drying. Accordingly, the light emitting layer 140B of each color can be formed in the order of application by sequentially discharging and applying the light emitting layer forming material of each color without performing such processing.
Then, as shown in FIG.5 (c), the reflective electrode 154 is formed in the whole surface of the transparent substrate 121, or stripe form, and an organic EL element is obtained.
[0065]
As described above, in the method of manufacturing the organic EL element of this example, the green pixel column of the light emitting layer and the pixel column of the hole injection layer 140A are arranged in the X direction of the transparent substrate 121 and the light emitting layer Since the red pixel column and the blue pixel column are formed in the Y direction, the hole injection layer 140A and the red, green, and blue light emitting layers are formed in the same ejection direction, and therefore Compared to the case where the unevenness of the luminous intensity of each color occurs in the same direction, the direction visually recognized as the unevenness of the light emission can be distributed in the X direction and the Y direction, thereby reducing the unevenness of the unevenness of the light emission and the overall display quality. This can be reduced and improved.
[0066]
In addition, since the partition wall 150 is formed on the transparent substrate 121 in advance and the hole injection layer forming material and the light emitting layer forming material are discharged and applied in the partition wall 150, Even if the landing position varies slightly, if it lands in the partition wall 150, a light emitting layer or the like can be formed at a desired position. Therefore, display quality can be improved by forming each pixel composed of the light emitting layer or the like at a desired position. Can be increased.
[0067]
In addition, in the organic EL element obtained in this way, since it is obtained by the above-described manufacturing method, unevenness in light emission unevenness is reduced, so that deterioration in display quality as a whole is reduced. , Display quality will be improved.
Further, even an EL display using this organic EL element has high display quality.
[0068]
Next, another example of the method for producing the organic EL element of the present invention will be described.
This example differs from the previous example in that when forming the hole injection layer 140A and the light emitting layer 140B by the ink jet method, the discharge of each forming material to a single pixel is not performed from the single nozzle hole 18. The point is that the nozzle holes 18 are used.
That is, in this example, as shown in FIGS. 8A to 8C, the interval between the nozzle holes 18 arranged in a row is narrower than that shown in FIGS. 7A to 7C. 10A is prepared, and a material for forming the hole injection layer 140A and the light emitting layer 140B is discharged by using 10A.
[0069]
In order to form the hole injection layer 140A and the light emitting layer 140B by the inkjet head 10A, first, as shown in FIG. 8B, the inkjet head 10A is arranged such that the row of nozzle holes 18 is in the Y direction of the transparent substrate 121. In this state, the inkjet head 10A and the transparent substrate 121 are moved relative to each other in the X direction in the direction indicated by the arrow in FIG. The forming material is discharged and applied. At this time, since the inkjet head 10A has a narrow interval between the nozzle holes 18 as described above, the discharge of the hole injection layer forming material to the single pixel 1A is not performed from the single nozzle hole 18, but a plurality of It is made simultaneously from the nozzle holes 18 (two nozzle holes 18 in this example). Then, a hole injection layer 140A is formed from the applied forming material in the same manner as in the previous example.
[0070]
In this way, by simultaneously discharging from a plurality of nozzle holes 18 to a single pixel 1A instead of from a single nozzle hole 18, the amount of forming material discharged to this pixel 1A is The variation between the plurality of nozzle holes 18 that have discharged is an averaged amount. Therefore, when the nozzle holes 18 forming the single hole injection layer 140A are compared for each group, the variation in the discharge amount between the groups is also averaged.
[0071]
When the hole injection layer 140A is thus formed, the light emitting layer forming material is discharged and applied in the same manner as in the previous example.
That is, first, as shown in FIG. 8A, the material for forming the red light emitting layer is intermittently discharged in the Y direction of the transparent substrate 121, and the red light emitting layer is preliminarily disposed among the pixels 1A arranged in the Y direction. A forming material is applied to the pixels (R1, R2, R3) set to be formed. Also in this case, as in the case of the hole injection layer forming material, the red light emitting layer forming material is discharged from the single pixel 1A to a plurality of nozzle holes 18 (in this example) instead of from the single nozzle hole 18. Then, the two nozzle holes 18) are performed simultaneously. For these pixel rows arranged in parallel in the Y direction, a plurality of rows (three rows in FIG. 8A) are simultaneously formed by a single scan by the inkjet head 10A, as in the previous example. It has become.
[0072]
When the red light emitting layer forming material is applied in this manner, in order to subsequently discharge the green light emitting layer forming material, as shown in FIG. Set to 121 in the Y direction. In this state, the green light emitting layer forming material is intermittently ejected in the X direction of the transparent substrate 121 in the same manner as in the previous example, and the green light emitting layer is preliminarily discharged among the pixels 1A arranged in the X direction. The forming material is applied to the pixels (G1, G2, G3, and G4) that are set so as to form. Also in this case, as in the case of the red light emitting layer forming material, the discharge of the green light emitting layer forming material to the single pixel 1A is not performed from the single nozzle hole 18 but a plurality of nozzle holes 18 (in this example). Simultaneously from the two nozzle holes 18). When intermittent discharge from the inkjet head 10 is performed, the discharge interval is made longer than in the case of forming the red light emitting layer, as in the previous example.
[0073]
When the green light emitting layer forming material is applied in this manner, the inkjet head 10A has a row of nozzle holes 18 arranged on a transparent substrate as shown in FIG. Set to 121 in the X direction. In this state, the blue light emitting layer forming material is intermittently ejected in the X direction of the transparent substrate 121 so that the blue light emitting layer is formed in advance among the pixels 1A arranged in the Y direction. A forming material is applied to the pixels (B1, B2, B3). Also in this case, as in the case of the red light emitting layer forming material, the blue light emitting layer forming material is discharged from the single pixel 1A to a plurality of nozzle holes 18 (in this example, not the single nozzle hole 18). Simultaneously from the two nozzle holes 18).
[0074]
Even when such a light emitting layer forming material is discharged, the discharge is not performed from the single nozzle hole 18 but from a plurality of nozzle holes 18 to the single pixel 1A at the same time, thereby forming the discharge onto the pixel 1A. The amount of the material can be an amount obtained by averaging the variation among the plurality of nozzle holes 18 that have ejected the material. Therefore, when the nozzle holes 18 forming the single hole injection layer 140A are compared for each group, the variation in the discharge amount between the groups is also averaged.
[0075]
Since both the hole injection layer 140A and the light emitting layers 140B of the respective colors are discharged simultaneously from the plurality of nozzle holes 18 to the single pixel 1A in this way, between the groups of the nozzle holes 18 As a result, the display quality as a whole can be improved.
Further, the green pixel column of the light emitting layer and the pixel column of the hole injection layer 140A are arranged in the X direction of the transparent substrate 121, and the red pixel column and the blue pixel column of the light emitting layer are arranged in the Y direction. As a result, the hole injection layer 140A and the red, green, and blue light emitting layers are formed in the same discharge direction, and therefore, the light emission is uneven compared to the case where unevenness in the luminous intensity of each color occurs in the same direction. The direction visually recognized as unevenness can be dispersed in the X direction and the Y direction, thereby reducing the unevenness of the light emission unevenness, reducing the deterioration of the display quality as a whole, and improving this.
[0076]
In addition, as shown in FIGS. 8A to 8C, when discharging from a plurality of nozzle holes 18 to a single pixel, the inkjet head 10A is injected with holes as shown in FIG. The discharge may be performed in a state inclined by a predetermined amount (for example, an angle θ in FIG. 9) with respect to the column direction of the pixels 1A forming the layer or the light emitting layer. In this way, if the inkjet head 10A is tilted by a predetermined amount and the inclination between the arrangement direction of the nozzle holes 18 and the moving direction (for example, the X-axis direction) is the angle θ, it appears more than the actual pitch D between the nozzle holes 18. The pitch E of the nozzles 18 can be made narrower, so that the single pixel 1A can be ejected from the plurality of nozzle holes 18 substantially simultaneously.
If the apparent interval between the nozzle holes 18 is reduced in this way, the number of nozzle holes 18 ejected to a single pixel 1A can be increased, and therefore the nozzle holes 18 as described above. The variation in the discharge amount among the groups can be further averaged, and the unevenness in light emission can be further reduced.
[0077]
In the above example, the arrangement of the pixels 1A... Is striped as shown in FIG. 10 (a), but the mosaic arrangement as shown in FIG. 10 (b) or as shown in FIG. 10 (c). The same effect can be obtained even in a delta arrangement.
In the above example, the hole injection layer 140A is formed as the lower layer of the light emitting layer 140B. However, the present invention is not limited to this. For example, a hole transport layer may be formed instead of the hole injection layer. May be. The material for forming this hole transport layer is not particularly limited, and for example, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives and the like are used.
[0078]
In the above example, the partition wall 150 that separates the pixels 1A is formed by subjecting the polyimide material and its surface to ink repellent treatment. However, the present invention is not limited to this, and the partition wall is formed by, for example, a resin black resist. Alternatively, a hole injection layer or a light emitting layer may be formed without providing a partition wall.
[0079]
Next, a specific example of an electronic apparatus provided with an EL display using the organic EL element of the above example will be described.
FIG. 11A is a perspective view showing an example of a mobile phone. In FIG. 11A, reference numeral 500 denotes a mobile phone body, and reference numeral 501 denotes an EL display unit (display means) including the EL display shown in FIGS.
FIG. 11B is a perspective view illustrating an example of a portable information processing apparatus such as a word processor or a personal computer. In FIG. 11B, 600 is an information processing apparatus, 601 is an input unit such as a keyboard, 603 is an information processing body, 602 is an EL display unit (display means) provided with the EL display shown in FIGS. ).
FIG. 11C is a perspective view showing an example of a wristwatch type electronic device. In FIG. 11C, reference numeral 700 denotes a watch body, and reference numeral 701 denotes an EL display unit (display means) including the EL display shown in FIGS.
Since the electronic device shown in FIGS. 11A to 11C is provided with the EL display, it is an electronic device provided with display means for obtaining excellent display quality.
[0080]
【The invention's effect】
As described above, according to the method for manufacturing an organic EL element of the present invention, the light emitting material that forms the light emitting layer of at least one of the light emitting layers is intermittently provided from the nozzle in the first direction (for example, the X direction). A second light emitting material that forms a row of light emitting layers composed of a plurality of light emitting layers and forms a light emitting layer of another color among the light emitting layers is substantially perpendicular to the first direction from the nozzle. Light emission formed in the discharge direction due to the variation in the discharge amount between the nozzles of the inkjet head, since the light emitting layer array composed of a plurality of light emitting layers is formed by intermittently discharging in the direction (for example, Y direction). Light emission unevenness between the rows of layers can be generated in a direction substantially orthogonal to at least one color of the light emitting layer and the other color, and therefore the direction of light emission unevenness is not biased in one direction. Reduces overall display quality degradation, It is possible to record improvements.
[0081]
According to the organic EL element of the present invention, the display quality is high by being obtained by the above manufacturing method.
According to the EL display of the present invention, a high display quality is obtained by using the organic EL element.
According to the electronic apparatus of the present invention, high display quality is obtained by using the EL display.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an arrangement part of an EL display according to the present invention.
FIG. 2 is an enlarged plan view showing a planar structure of a pixel portion.
FIGS. 3A to 3E are cross-sectional side views of a main part for explaining the method of manufacturing an organic EL element of the present invention in the order of steps.
4A to 4C are cross-sectional side views of a main part for sequentially explaining steps subsequent to FIG. 3;
FIGS. 5A to 5C are side cross-sectional views of relevant parts for sequentially explaining steps following FIG. 4; FIGS.
6A and 6B are diagrams for explaining a schematic configuration of the inkjet head, in which FIG. 6A is a perspective view of a main part, and FIG. 6B is a side sectional view of the main part.
FIGS. 7A to 7C are schematic views for sequentially explaining an example of a process of discharging a light emitting layer forming material from a nozzle hole of an inkjet head. FIGS.
FIGS. 8A to 8C are schematic views for sequentially explaining another example of a process of discharging a light emitting layer forming material from a nozzle hole of an inkjet head. FIGS.
FIG. 9 is a schematic diagram for explaining an example in which the inkjet head is ejected in a state where the inkjet head is tilted by a predetermined amount.
10A and 10B are diagrams for explaining a pixel arrangement pattern, where FIG. 10A is a stripe pattern, FIG. 10B is a mosaic pattern, and FIG. 10C is a delta pattern.
FIGS. 11A and 11B are diagrams illustrating a specific example of an electronic device provided with an EL display, where FIG. 11A is a perspective view illustrating an example when applied to a mobile phone, and FIG. 11B is a case when applied to an information processing apparatus; FIG. 7C is a perspective view showing an example when applied to a wristwatch type electronic device.
FIG. 12 is a schematic diagram for explaining a conventional example of a process for discharging a light emitting layer forming material from a nozzle hole of an inkjet head.
[Explanation of symbols]
1A: Pixel, 10, 10A: Inkjet head,
18 ... Nozzle hole (nozzle), 121 ... Transparent substrate, 140A ... Hole injection layer,
140B ... luminous layer, 150 ... partition

Claims (10)

A method of manufacturing an organic EL element, wherein a plurality of light emitting layers are formed by discharging a light emitting material from a nozzle of an inkjet head onto a substrate, and a plurality of pixels are formed vertically and horizontally corresponding to each of the light emitting layers,
A light emitting material for forming a light emitting layer of at least one of the light emitting layers is intermittently ejected from the nozzle in a first direction to form a row of light emitting layers composed of a plurality of light emitting layers,
A light emitting material that forms a light emitting layer of another color among the light emitting layers is intermittently ejected from the nozzle in a second direction substantially orthogonal to the first direction. A method for producing an organic EL element, comprising forming a row. In the manufacturing method of the organic EL element of Claim 1,
The light emitting layer is formed in three colors of red, green, and blue, and a hole injection layer or a hole transport layer is ejected from the nozzle of the ink jet head to each pixel forming the light emitting layer. In forming by
Forming each row by discharging one color of the light emitting layer and a hole injection layer or a hole transport layer in a first direction with each material;
A method of manufacturing an organic EL element, wherein each of the other two colors of the light emitting layer is formed by discharging each material in a second direction. A single light-emitting layer corresponding to each pixel is formed by ejecting a light-emitting material from a plurality of nozzles arranged substantially orthogonal to the column direction of the light-emitting layer to be formed, approximately simultaneously. The manufacturing method of the organic EL element of Claim 1 or 2. A single hole injection layer or hole transport layer corresponding to each pixel is substantially simultaneously formed from a plurality of nozzles arranged substantially orthogonal to the column direction of the hole injection layer or hole transport layer to be formed. 3. The method of manufacturing an organic EL element according to claim 2, wherein the organic EL element is formed by discharging a material. 4. The method of manufacturing an organic EL element according to claim 3, wherein the nozzles of the ink jet head are ejected in a state inclined by a predetermined amount with respect to the direction of the light emitting layer to be formed. 5. The method for producing an organic EL device according to claim 4, wherein the nozzle row of the ink jet head is ejected in a state inclined by a predetermined amount with respect to the column direction of the hole injection layer or hole transport layer to be formed. The organic EL according to any one of claims 1 to 6, wherein a partition wall for separating pixels is formed on the substrate in advance, and a light emitting layer is formed by discharging the light emitting material into the partition wall. Device manufacturing method. The organic EL element obtained by the manufacturing method in any one of Claims 1-7. An EL display comprising the organic EL element according to claim 8. An electronic apparatus comprising the EL display according to claim 9 as display means.

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