JP4157303B2

JP4157303B2 - Display device manufacturing method

Info

Publication number: JP4157303B2
Application number: JP2002027125A
Authority: JP
Inventors: 修一内古閑; 正浩多田
Original assignee: 東芝松下ディスプレイテクノロジー株式会社
Priority date: 2002-02-04
Filing date: 2002-02-04
Publication date: 2008-10-01
Anticipated expiration: 2022-02-04
Also published as: JP2003228299A

Description

【０００１】
【発明の属する技術分野】
本発明は、表示画素が有機ＥＬ（エレクトロルミネッセンス）素子等の自己発光素子からなる自己発光型表示装置の製造部品として表示装置基板を用いた表示装置製造方法に関し、特に駆動素子が自己発光素子毎に形成される表示装置基板を用いた表示装置製造方法に関する。
【０００２】
【従来の技術】
近年では、有機ＥＬ表示装置が軽量、薄型、高輝度という特徴を持つことからノート型パーソナルコンピュータや携帯用情報機器等の分野で液晶表示装置に代替可能なモニタディスプレイとして注目されている。この用途では、アクティブマトリクス型有機ＥＬ表示装置の開発が盛んである。このアクティブマトリクス型有機ＥＬ表示装置は、表示画素としてマトリクス状に配置される複数の有機ＥＬ素子、複数の有機ＥＬ素子の行に沿って配置される複数の走査線、複数の有機ＥＬ素子列に沿って配置される複数の信号線、これら走査線および信号線の交差位置近傍に配置され複数の有機ＥＬ素子に流れる電流をそれぞれ制御する複数の電流制御回路を備える。
【０００３】
有機ＥＬ素子は供給電流量に応じた輝度で自己発光する発光ダイオードであり、陽極および陰極間に有機材料層を挟持した構造を有する。有機材料層は、例えば赤、緑、または青の蛍光性有機化合物を含む薄膜である発光層、この発光層に陽極からの正孔を注入する正孔輸送層、およびこの発光層に陰極からの電子を注入する電子輸送層などを積層して得られる。直流電圧が有機ＥＬ素子の陽極および陰極間に印加されると、発光層は正孔輸送層および電子輸送層を介して注入される電子および正孔の再結合により励起子を生成し、この励起子の失活時に生じる光放出により発光する。電流制御回路は走査線を介して駆動されたときに信号線からの表示信号を取り込む画素スイッチ、一対の電源端子間において有機ＥＬ素子と直列に接続され画素スイッチからの表示信号に基づいて有機ＥＬ素子に電流を流す駆動素子、および画素スイッチが非導通である状態で表示信号を保持する容量素子等を含む。画素スイッチおよび駆動素子はガラス板のような安価な基板上に有機ＥＬ素子と一緒に形成可能な薄膜半導体素子により構成される。現在では、ポリシリコン半導体薄膜トランジスタが有機ＥＬ素子に十分な電流を供給可能な薄膜半導体素子として注目を集めている。
【０００４】
有機ＥＬ表示装置の製造では、これら薄膜半導体素子が走査線、信号線、および容量素子を構成するような配線と一緒に表示装置基板として基板形成工程で形成される。この後、画素形成工程がこの基板形成工程で得られた表示装置基板上に複数の有機ＥＬ素子を形成するために行われる。薄膜半導体素子あるいは配線の欠陥が基板形成工程で発生した場合、この欠陥を含む不良基板を画素形成工程に進めても最終的に得られる有機ＥＬ表示装置に正常な動作を期待することができない。従って、製品の歩留りが画素形成工程前に混入した不良基板のために低下し、製造コストが画素形成工程で不良基板に対して無駄に消費される処理時間および材料のために上昇する。
【０００５】
【発明が解決しようとする課題】
しかしながら、従来の構造では、薄膜半導体素子を形成しても、駆動素子は有機ＥＬ素子を形成するまで有機ＥＬ素子に接続されない状態にある。このような状態では、不良基板を発見するために有機ＥＬ素子に流れる電流を実際に測定できない。この結果、画素形成工程前に不良基板を除去して製品の歩留りを向上させることが困難であった。
【０００６】
本発明は上述のような問題に鑑みてなされたもので、自己発光素子の形成前に不良基板を発見する検査を行うことが可能な表示装置基板を用いた表示装置製造方法を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明によれば、絶縁基板と、この絶縁基板上に形成される第１および第２電源端子と、絶縁基板上で略マトリクス状に配置される複数の自己発光素子電極と、絶縁基板上で複数の自己発光素子電極および第１電源端子間にそれぞれ接続される複数の駆動素子と、これら駆動素子により制御される検査用電荷を保持するように絶縁基板上で複数の自己発光素子電極にそれぞれ容量結合して第２電源端子に接続される複数の検査電極とを備える表示装置基板を形成する基板形成工程と、複数の自己発光素子電極および複数の検査電極間の容量に保持される電荷の量について表示装置基板を検査して不良表示装置基板を除去する基板検査工程と、基板検査工程で除去されずに残った表示装置基板を用いて複数の自己発光素子を形成する画素形成工程とを備え、複数の自己発光素子の各々は対応自己発光素子電極からなる第１電極、この第１電極上に形成される発光部材層、およびこの発光部材層上に形成される第２電極を含み、画素形成工程は複数の検査電極を第２電源端子から切り離し複数の自己発光素子の第２電極を第２電源端子に接続する工程を含む表示装置製造方法が提供される。
【０００９】
この表示装置製造方法では、複数の検査電極が複数の駆動素子により制御される検査用電荷をそれぞれ保持するように絶縁基板上で複数の自己発光素子電極に容量結合して第２電源端子に接続される。これにより、複数の自己発光素子電極および複数の検査電極間の容量にそれぞれ保持される電荷の量についてエレクトロンビームテスタ等を用いて表示装置基板を検査し不良表示装置基板を除去することが可能となる。すなわち、正常な表示装置基板だけが複数の自己発光素子を形成するために用いられるため、製品の歩留りを向上させることができる。この場合、不良基板のために無駄に消費される処理時間および材料による製造コストの上昇を防止でき、全体としての生産性を向上できる。
【００１０】
【発明の実施の形態】
以下、本発明の第１実施形態に係る表示装置基板について添付図面を参照して説明する。この表示装置基板は例えば下面側から外部に光を取り出す下面発光型の有機ＥＬ表示装置の製造部品として用いられる。
【００１１】
図１はこの表示装置基板の回路構成を全体的に示し、図２は図１において隣接する３画素分の有機ＥＬ素子電極周辺の平面構造を示す。表示装置基板は光透過性の絶縁基板１、この絶縁基板１の表示領域ＤＳにマトリクス状に配置される複数の有機ＥＬ素子電極ＰＸ、複数の有機ＥＬ素子電極ＰＸの行に沿った複数の走査線Ｙ（Ｙ１〜Ｙｍ）、複数の有機ＥＬ素子電極ＰＸの列に沿った複数の信号線Ｘ（Ｘ１〜Ｘｎ）、並びに走査線Ｙ１〜Ｙｍを駆動する走査線駆動回路２、および信号線Ｘ１〜Ｘｎを駆動する信号線駆動回路３を備える。走査線駆動回路２および信号線駆動回路３は表示領域ＤＳの外側に配置される。
【００１２】
複数の有機ＥＬ素子電極ＰＸは例えば赤（Ｒ），緑（Ｇ），または青（Ｂ）の発光色で自己発光する有機ＥＬ素子のための開口領域をそれぞれ規定すると共に、これら有機ＥＬ素子に流れる電流を制御する複数の電流制御回路４にそれぞれ接続される。これら電流制御回路４は複数の走査線Ｙおよび複数の応信号線Ｘの交差位置に隣接して絶縁基板１上に形成される。走査線駆動回路２からの走査パルスは対応行の電流制御回路４を制御し、信号線駆動回路３からの表示信号は信号線を介して対応列の電流制御回路４に供給される。各電流制御回路４は電源端子Ｖddおよび対応有機ＥＬ素子電極ＰＸ間に接続されるＰチャネル型薄膜トランジスタ５、対応信号線Ｘおよび薄膜トランジスタ５のゲート間に接続されるＮチャネル型薄膜トランジスタ６、および電源端子Ｖddおよび薄膜トランジスタ５のゲート間に接続される容量素子７を含む。薄膜トランジスタ５は有機ＥＬ素子のための駆動素子として形成される。薄膜トランジスタ６は対応走査線Ｙを介して走査パルスが供給されたときに対応信号線Ｘからの表示信号を取り込み制御電圧として薄膜トランジスタ５のゲートに供給する画素スイッチとして形成される。容量素子７は薄膜トランジスタ６が非導通状態であるときに薄膜トランジスタ５の制御電圧を保持するために形成される。
【００１３】
この表示装置基板はさらに複数の薄膜トランジスタ６により制御される検査用電荷をそれぞれ保持するように絶縁基板１上で複数の有機ＥＬ素子電極ＰＸに容量結合して検査用電源端子Ｖtestに接続される複数の検査電極ＰＴを含む。各有機ＥＬ素子電極ＰＸは有機ＥＬ素子から放出される光を絶縁基板１を介して出射させるためにＩＴＯ（Indium Tin Oxide）のような光透過性電極材料層からなり、各検査電極ＰＴは例えば図２に示すように対応行の有機ＥＬ素子電極ＰＸの開口率を低下させないようにこれらの有機ＥＬ素子電極ＰＸの端部にそれぞれ対向して絶縁基板１上に形成される金属層からなる。
【００１４】
次に上述の表示装置基板を用いた有機ＥＬ表示装置の製造方法について述べる。図３は図２に示す各有機ＥＬ素子電極周辺の断面構造を示す。最初の基板形成工程では、光透過性絶縁基板１が用意される。この絶縁基板１はシリコンの拡散を阻止するバリアとなる下地表面を持つガラス板等であり、下地表面は例えばシリコン窒化膜とこのシリコン窒化膜を覆うシリコン酸化膜との積層体からなる。続いて、例えばトップゲート型のポリシリコン薄膜トランジスタが薄膜トランジスタ５および６としてこの絶縁基板１上に形成される。薄膜トランジスタ５および６は、ポリシリコン半導体薄膜１０を絶縁基板１の下地表面上に形成し、この半導体薄膜１０を覆って酸化シリコンのゲート絶縁膜１１を形成し、ゲート絶縁膜１１を覆って例えばＭｏＷ金属層を形成し、ゲート絶縁膜１１を介して半導体薄膜１０に対向するゲート電極Ｇを残してＭｏＷ金属層をパターニング処理し、さらにこのゲート電極Ｇをマスクとして半導体薄膜１０内に所定濃度の不純物をドープしてソースおよびドレインを形成することにより得られる。
【００１５】
検査電極ＰＴはＭｏＷ金属層のパターニング処理で薄膜トランジスタ５のゲート電極Ｇに接続される容量素子７の第１電極、薄膜トランジスタ６のゲート電極Ｇに接続される走査線Ｙ、および検査用電源端子Ｖtestおよび検査電極ＰＴを結ぶ配線と一緒に形成される。続いて、酸化シリコンの層間絶縁膜１２がゲート絶縁膜１１、検査電極ＰＴ、ゲート電極Ｇ、走査線Ｙ、容量素子７の第１電極を覆うように形成され、さらにＩＴＯ（Indium Tin Oxide）等の光透過性電極材料層が層間絶縁膜１２を覆って形成される。この光透過性電極材料層は有機ＥＬ素子電極ＰＸを残すようにパターニング処理される。この有機ＥＬ素子電極ＰＸは一旦レジストマスクで覆われ、複数のコンタクトホールが薄膜トランジスタ５および６のソースおよびドレイン等を露出して形成される。続いて、ソース電極Ｓ、ドレイン電極Ｄ、信号線Ｘ、容量素子７の第１電極に対向する容量素子７の第２電極を兼ねて電源端子Ｖddに接続されるＶdd側電源線がＭｏ／Ａｌ／Ｍｏのような３層構造の金属層として層間絶縁膜１２上に形成される。ここで、薄膜トランジスタ５および６のソース電極Ｓおよびドレイン電極Ｄはコンタクトホールを介して薄膜トランジスタ５および６のソースおよびドレインに接続される。薄膜トランジスタ５のソース電極Ｓは有機ＥＬ素子電極ＰＸに接続され、薄膜トランジスタ５のドレイン電極ＤはＶdd側電源線に接続される。薄膜トランジスタ６のソース電極Ｓはコンタクトホールを介して容量素子７の第１電極に接続され、薄膜トランジスタ６のドレイン電極Ｄは信号線Ｘに接続される。
【００１６】
この状態で、窒化シリコンの保護絶縁膜１３が有機ＥＬ素子電極ＰＸ、ソース電極Ｓ、ドレイン電極Ｄおよび層間絶縁膜１２を全体的に覆って形成され、有機ＥＬ素子電極ＰＸを部分的に露出するようにパターニング処理される。続いて、絶縁膜１４、例えば酸化シリコン膜が保護絶縁膜１３および有機ＥＬ素子電極ＰＸの露出部を全体的に覆って形成され、再び有機ＥＬ素子電極ＰＸを部分的に露出するようにパターニング処理される。続いて、表面処理した有機絶縁膜１５、例えばアクリル樹脂が絶縁膜１４および有機ＥＬ素子電極ＰＸの露出部を全体的に覆って形成され、再び有機ＥＬ素子電極ＰＸを部分的に露出するようにパターニング処理される。これらパターニング処理は有機ＥＬ素子電極ＰＸを部分的に露出しこの露出面に向かってテーパ状となる開口ＯＰを保護絶縁膜１３、親水性絶縁膜１４、および撥水性有機絶縁膜１５の絶縁体に形成することになる。基板形成工程はこれにより完了する。
【００１７】
続く基板検査工程では、複数の有機ＥＬ素子電極ＰＸおよび複数の検査電極ＰＴ間の容量Ｃtestにそれぞれ保持される電荷の量について表示装置基板が検査され、不良基板がこの検査結果に基づいて除去される。ここでは、所定の検査電圧を電源端子Ｖddおよび検査用電源端子Ｖtest間に印加し、電流制御回路４の制御により複数の有機ＥＬ素子電極ＰＸおよび複数の検査電極ＰＴ間の全容量に電荷を保持させ、例えばエレクトロンビームテスタを用いて表示装置基板の不良を検出する。このエレクトロンビームテスタは電子ビームを表示装置基板に照射することにより２次放出される電子ビームを捕捉して容量Ｃtestの蓄積電荷量に依存した複数の有機ＥＬ素子電極ＰＸの電位分布を画像として表示する。検査担当者はこの画像を観察し、薄膜トランジスタ５を含む電流制御回路４の動作が正常であるかどうかを確認して不良基板を特定する。また、エレクトロンビームテスタを用いる代わりに、複数の有機ＥＬ素子電極ＰＸおよび複数の検査電極ＰＴ間の容量Ｃtestに電荷を順次保持させ、各容量Ｃtestの電荷量を検査用電源端子Ｖtestから測定する積分回路を用いて表示装置基板の不良を検出してもよい。
【００１８】
続く画素形成工程では、図４に示すように複数の有機ＥＬ素子OLEDが基板検査工程で除去されずに残った、あるいは欠陥箇所をリペアするなどして基板検査工程で正常であると判断された表示装置基板を用いて形成される。この有機ＥＬ素子OLEDは有機材料層１６を一対のカソード電極１７およびアノード電極１８間に挟持した構造を有する。ここでは、有機ＥＬ素子電極ＰＸが上述のアノード電極１８として用いられる。有機材料層１６は例えば発光層ＥＭ、バッファ層１９、および電子輸送層２０を積層して構成される。発光層ＥＭは赤、緑、または青の蛍光性有機化合物を含む薄膜である。バッファ層１９は発光層ＥＭおよびアノード電極１８間に形成され、電子輸送層２０は発光層ＥＭおよびカソード電極１７間に形成される。アノード電極１８は例えばＩＴＯで構成される光透過性電極であり、カソード電極１７はＢａのような金属で構成される反射電極である。また、カソード電極は、Ａｇ等の保護層２１に覆われるよう構成される。
【００１９】
実際の画素形成工程では、例えば一定量の水溶性高分子溶液がインクジェット方式で開口ＯＰ内に注入され、これによりバッファ層１９を形成する。この後、一定量の蛍光性有機化合物を含む高分子溶液がインクジェット方式で開口ＯＰ内に注入され、これにより発光層ＥＭを形成する。この後、一定量の高分子溶液がインクジェット方式で開口ＯＰ内に注入され、これにより電子輸送層２０を形成する。撥水性絶縁膜１５および電子輸送層２０は金属蒸着により形成されるカソード電極１７、保護層２１で覆われる。カソード電極１７は表示装置基板において検査用電源端子Ｖtestとは独立に電源端子Ｖssに接続される。こうして得られた構造物はその外周端部付近に塗布されるシール材によりガラス板、金属板のような支持板２２に窒素雰囲気中で接着され、これにより窒素が保護層２１および支持板２２との間に封止される。
【００２０】
上述の有機ＥＬ素子OLEDは、アノード電極ＡＤから注入されたホールとカソード電極１７から注入された電子とが発光層ＥＭの内部で再結合したときに、発光層ＥＭを構成する有機分子を励起して励起子を発生させる。この励起子が放射失活する過程で発光し、この光が発光層ＥＭから光透過性のアノード電極１８、層間絶縁膜１２、ゲート絶縁膜１１、および絶縁基板１を介して外部へ出射する。この有機材料層１６は上述のような３層構造だけでなく、自己発光するように機能的に複合された２層または単層で構成することが可能である。また、電子輸送層２０は省略可能である。さらに、本実施形態ではアノード電極１８を光透過性電極とし、この光透過性電極を介して光を外部に取り出すが、カソード電極１７を光透過性電極とし、アノード電極１８を光反射性電極で構成しカソード電極１７側から光を外部に取り出してもよい。
【００２１】
図５は上述の製造方法で形成された有機ＥＬ表示装置の画素周辺回路を示す。基板形成工程では、有機ＥＬ素子OLEDがアノード電極１８となる有機ＥＬ素子電極ＰＸを除いて形成されないため、電源電圧を電源端子ＶddおよびＶss間に印加して有機ＥＬ素子OLEDの駆動素子となる薄膜トランジスタ５の動作を確認することができない。その代わりに、検査電極ＰＴがこの有機ＥＬ素子電極ＰＸに容量結合して検査用電源端子Ｖtestに接続される。これにより、検査電圧を電源端子Ｖddおよび検査用電源端子Ｖtest間に印加し、薄膜トランジスタ５を介して流れる電流Idにより有機ＥＬ素子電極ＰＸおよび検査電極ＰＴ間の容量Ｃtestに電荷を蓄積させることができる。有機ＥＬ素子電極ＰＸの電位はこの容量Ｃtestに蓄積された電荷に依存し、これにより検査電圧が検査用電源端子Ｖtestの電位を基準として容量Ｃtestに対応する電圧Ｖｆと薄膜トランジスタ５に対応する電圧Ｖdsに分圧されることになる。従って、有機ＥＬ素子電極ＰＸの電位を観測することにより薄膜トランジスタ５の動作を確認できる。薄膜トランジスタ５に欠陥がなくても、少なくとも走査線駆動回路２、信号線駆動回路３、電流制御回路４のいずれかに欠陥があるという状態が検出されるため、不良基板を特定可能である。
【００２２】
上述の実施形態では、複数の検査電極ＰＴが有機ＥＬ素子OLEDの駆動素子となる複数の薄膜トランジスタ５により制御される検査用電荷をそれぞれ保持するように絶縁基板１上で複数の有機ＥＬ素子電極ＰＸに容量結合して検査用電源端子Ｖtestに接続される。これにより、複数の有機ＥＬ素子電極ＰＸおよび複数の検査電極ＰＴ間の容量Ｃtestにそれぞれ保持される電荷の量についてエレクトロンビームテスタ等を用いて表示装置基板を検査し不良表示装置基板を除去することが可能となる。すなわち、正常な表示装置基板だけが複数の有機ＥＬ素子OLEDを形成するために用いられるため、製品の歩留りを向上させることができる。この場合、不良基板のために無駄に消費される処理時間および材料による製造コストの上昇を防止でき、全体としての生産性が向上する。結論としては、有機ＥＬ素子のような自己発光素子の駆動素子に接続される配線電極と容量結合する検査電極を設け、これら配線電極および検査電極間に容量を形成することが重要である。
【００２３】
尚、本発明は上述の実施形態に限定されず、その要旨を逸脱しない範囲で様々に変形可能である。
【００２４】
図６は図５に示す回路構成の第１変形例を示す。上述の実施例では、検査用電源端子Ｖtestが電源端子Ｖssから独立に形成されるが、この検査用電源端子Ｖtestを電源端子Ｖssとして共用してもよい。この構成にする場合には、基板検査工程後に検査用電源端子Ｖtestおよび検査電極ＰＴ間の配線をレーザトリミング等により例えば図６に示すように切断することが好ましい。これを行うことにより、容量Ｃtestが有機ＥＬ素子OLEDに並列な寄生容量として完成品の有機ＥＬ表示装置の動作に影響を与えることが避けられる。また、各電流制御回路４は例えば図６に示すように接続されたスイッチＳＷ１，ＳＷ２および容量素子ＣＫにより構成される公知の閾値キャンセル回路を含むように構成されても良い。これにより、複数の薄膜トランジスタ６間の閾値のバラツキに影響されることなく有機ＥＬ素子OLEDに流れる電流を制御することが可能となる。
【００２５】
図７は図５に示す回路構成の第２変形例を示す。上述の実施例では、複数の検査電極ＰＴの各々が図７に示すように対応有機ＥＬ素子電極ＰＸに容量結合して検査用電源端子Ｖtestに接続されたが、複数の検査抵抗Ｒtestの各々が対応有機ＥＬ素子電極ＰＸおよび検査用電源端子Ｖtest間に接続されてもよい。基板検査工程では、これら検査抵抗Ｒtestに流れる電流について表示装置基板が検査され、この検査結果に基づいて不良基板が除去される。この構成にする場合には、基板検査工程後に検査用電源端子Ｖtestおよび検査抵抗Ｒtest間の配線または検査抵抗Ｒtestおよび有機ＥＬ素子電極ＰＸ間の配線のいずれかをレーザトリミング等により例えば図７に示すように切断する必要がある。これを行うことにより、検査抵抗Ｒtestが有機ＥＬ素子OLEDに並列な電流路を形成して完成品の有機ＥＬ表示装置の動作に影響を与えることが無くなる。
【００２６】
また、上述の実施形態では、下面発光型の有機ＥＬ表示装置の製造部品として用いられる表示装置基板について説明したが、本発明は上面発光型の有機ＥＬ表示装置の製造部品として用いられる表示装置基板に適用することもできる。この上面発光型の有機ＥＬ表示装置では、有機ＥＬ素子OLEDから放出される光が絶縁基板１を介さずに上面から出射するため、有機ＥＬ素子電極ＰＸを透過する光を遮断しないように上述の検査電極ＰＴを配置する必要がない。従って、例えば有機ＥＬ素子電極ＰＸの中央部の下方に検査電極ＰＴを配置して検査電極ＰＴと有機ＥＬ素子電極ＰＸとを容量結合させてもよい。
【００２７】
【発明の効果】
以上のように本発明によれば、自己発光素子の形成前に不良基板を発見する検査を行うことが可能な表示装置基板およびこの表示装置基板を用いた表示装置製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る表示装置基板の回路構成を全体的に示す図である。
【図２】図１において隣接する３画素分の有機ＥＬ素子電極周辺の平面構造を示す図である。
【図３】図２に示す各有機ＥＬ素子電極周辺の断面構造を示す図である。
【図４】図３に示す断面構造の表示装置基板に形成された有機ＥＬ素子の断面構造を示す図である。
【図５】図４に示す有機ＥＬ素子を形成して完成した有機ＥＬ表示装置の画素周辺回路を示す図である。
【図６】図５に示す画素周辺回路の第１変形例を示す図である。
【図７】図５に示す画素周辺回路の第２変形例を示す図である。
【符号の説明】
１…絶縁基板
４…電流制御回路
５…電流駆動用薄膜トランジスタ
６…画素スイッチ用薄膜トランジスタ
７…容量素子
ＰＸ…有機ＥＬ素子電極
ＰＴ…検査電極
Ｖdd，Ｖss…電源端子
Ｖtest…検査用電源端子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device manufacturing method using a display device substrate as a manufacturing component of a self-luminous display device in which a display pixel is composed of a self-luminous element such as an organic EL (electroluminescence) element, and in particular, a driving element is provided for each self-luminous element. The present invention relates to a display device manufacturing method using a display device substrate formed on a substrate.
[0002]
[Prior art]
In recent years, organic EL display devices have attracted attention as monitor displays that can replace liquid crystal display devices in the fields of notebook personal computers, portable information devices, and the like because of their light weight, thinness, and high brightness. In this application, active matrix organic EL display devices are actively developed. This active matrix organic EL display device includes a plurality of organic EL elements arranged in a matrix as display pixels, a plurality of scanning lines arranged along a row of the plurality of organic EL elements, and a plurality of organic EL element columns. And a plurality of current control circuits that respectively control currents that flow through the plurality of organic EL elements and that are disposed in the vicinity of the intersection positions of the scanning lines and the signal lines.
[0003]
The organic EL element is a light-emitting diode that self-emits with a luminance corresponding to the amount of supplied current, and has a structure in which an organic material layer is sandwiched between an anode and a cathode. The organic material layer includes, for example, a light emitting layer that is a thin film containing a fluorescent organic compound of red, green, or blue, a hole transport layer that injects holes from the anode into the light emitting layer, and a cathode from the cathode into the light emitting layer. It is obtained by laminating an electron transport layer for injecting electrons. When a DC voltage is applied between the anode and cathode of the organic EL device, the light emitting layer generates excitons by recombination of electrons and holes injected through the hole transport layer and the electron transport layer, and this excitation Light is emitted by light emission that occurs when the child is deactivated. A current control circuit is a pixel switch that captures a display signal from a signal line when driven through a scanning line, and is connected in series with an organic EL element between a pair of power supply terminals, and is based on the display signal from the pixel switch. A driving element that supplies current to the element, a capacitor element that holds a display signal in a state where the pixel switch is non-conductive, and the like are included. The pixel switch and the drive element are constituted by a thin film semiconductor element that can be formed together with an organic EL element on an inexpensive substrate such as a glass plate. At present, polysilicon semiconductor thin film transistors are attracting attention as thin film semiconductor elements capable of supplying a sufficient current to organic EL elements.
[0004]
In the manufacture of an organic EL display device, these thin film semiconductor elements are formed in a substrate forming process as a display device substrate together with wirings constituting scan lines, signal lines, and capacitive elements. Thereafter, a pixel forming step is performed to form a plurality of organic EL elements on the display device substrate obtained in the substrate forming step. When a defect of a thin film semiconductor element or wiring occurs in the substrate forming process, normal operation cannot be expected in the finally obtained organic EL display device even if a defective substrate including this defect is advanced to the pixel forming process. Therefore, the product yield is reduced due to the defective substrate mixed before the pixel forming process, and the manufacturing cost is increased due to the processing time and material that are wasted on the defective substrate in the pixel forming process.
[0005]
[Problems to be solved by the invention]
However, in the conventional structure, even if the thin film semiconductor element is formed, the driving element is not connected to the organic EL element until the organic EL element is formed. In such a state, the current flowing through the organic EL element cannot be actually measured in order to find a defective substrate. As a result, it is difficult to remove the defective substrate before the pixel formation process and improve the yield of the product.
[0006]
The present invention has been made in view of the above-described problems, and provides a display device manufacturing method using a display device substrate capable of performing an inspection to find a defective substrate before forming a self-light-emitting element. Objective.
[0008]
[Means for Solving the Problems]
According to the present invention, an insulating substrate, first and second power supply terminals formed on the insulating substrate, a plurality of self-light-emitting element electrodes arranged in a substantially matrix shape on the insulating substrate, and the insulating substrate A plurality of drive elements respectively connected between the plurality of self-light-emitting element electrodes and the first power supply terminal, and a plurality of self-light-emitting element electrodes on the insulating substrate so as to hold inspection charges controlled by these drive elements, respectively A substrate forming step of forming a display device substrate having a plurality of inspection electrodes coupled to the second power supply terminals by capacitive coupling; and a charge held in a capacitance between the plurality of self-light emitting element electrodes and the plurality of inspection electrodes A substrate inspection process for inspecting the display device substrate for the amount and removing the defective display device substrate, and a pixel forming process for forming a plurality of self-luminous elements using the display device substrate remaining without being removed in the substrate inspection step With the door, the first electrode each of the plurality of self-luminous elements made of corresponding self-luminous element electrodes, the light emitting member layer formed on the first electrode, and a second electrode formed on the light emitting member layer In addition, there is provided a display device manufacturing method including a step of separating the plurality of inspection electrodes from the second power supply terminal and connecting the second electrodes of the plurality of self-light emitting elements to the second power supply terminal .
[0009]
In this display device manufacturing method, a plurality of test electrodes are capacitively coupled to a plurality of self-light emitting element electrodes on an insulating substrate so as to hold test charges controlled by a plurality of driving elements, and connected to a second power supply terminal. Is done. As a result, it is possible to inspect the display device substrate using an electron beam tester or the like and remove the defective display device substrate with respect to the amount of electric charge held in the capacitance between the plurality of self-light emitting element electrodes and the plurality of inspection electrodes. Become. That is, since only a normal display device substrate is used to form a plurality of self-light emitting elements, the yield of products can be improved. In this case, it is possible to prevent an increase in manufacturing cost due to processing time and materials that are wasted due to a defective substrate, and it is possible to improve productivity as a whole.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a display device substrate according to a first embodiment of the present invention will be described with reference to the accompanying drawings. This display device substrate is used, for example, as a manufacturing part of a bottom emission type organic EL display device that extracts light from the bottom surface side to the outside.
[0011]
FIG. 1 shows an overall circuit configuration of the display device substrate, and FIG. 2 shows a planar structure around the organic EL element electrodes for three adjacent pixels in FIG. The display device substrate is a light-transmissive insulating substrate 1, a plurality of organic EL element electrodes PX arranged in a matrix in the display region DS of the insulating substrate 1, and a plurality of scans along a row of the plurality of organic EL element electrodes PX. The scanning line driving circuit 2 for driving the lines Y (Y1 to Ym), the plurality of signal lines X (X1 to Xn) along the column of the plurality of organic EL element electrodes PX, the scanning lines Y1 to Ym, and the signal line X1 The signal line drive circuit 3 for driving .about.Xn is provided. The scanning line driving circuit 2 and the signal line driving circuit 3 are arranged outside the display area DS.
[0012]
The plurality of organic EL element electrodes PX each define an opening region for an organic EL element that emits light in a red (R), green (G), or blue (B) emission color, for example. Each is connected to a plurality of current control circuits 4 for controlling the flowing current. These current control circuits 4 are formed on the insulating substrate 1 adjacent to the intersections of the plurality of scanning lines Y and the plurality of response signal lines X. The scanning pulse from the scanning line driving circuit 2 controls the current control circuit 4 in the corresponding row, and the display signal from the signal line driving circuit 3 is supplied to the current control circuit 4 in the corresponding column via the signal line. Each current control circuit 4 includes a P-channel thin film transistor 5 connected between the power supply terminal Vdd and the corresponding organic EL element electrode PX, an N-channel thin film transistor 6 connected between the corresponding signal line X and the gate of the thin film transistor 5, and a power supply terminal. A capacitive element 7 connected between Vdd and the gate of the thin film transistor 5 is included. The thin film transistor 5 is formed as a drive element for the organic EL element. The thin film transistor 6 is formed as a pixel switch that takes in a display signal from the corresponding signal line X and supplies it as a control voltage to the gate of the thin film transistor 5 when a scanning pulse is supplied through the corresponding scanning line Y. The capacitor element 7 is formed to hold the control voltage of the thin film transistor 5 when the thin film transistor 6 is in a non-conductive state.
[0013]
The display device substrate is further coupled to the plurality of organic EL element electrodes PX on the insulating substrate 1 so as to hold the inspection charges controlled by the plurality of thin film transistors 6 and connected to the inspection power supply terminal Vtest. The test electrode PT is included. Each organic EL element electrode PX is composed of a light transmissive electrode material layer such as ITO (Indium Tin Oxide) in order to emit light emitted from the organic EL element through the insulating substrate 1, and each inspection electrode PT is, for example, As shown in FIG. 2, it is made of a metal layer formed on the insulating substrate 1 so as to face the end portions of the organic EL element electrodes PX so as not to decrease the aperture ratio of the organic EL element electrodes PX in the corresponding row.
[0014]
Next, a method for manufacturing an organic EL display device using the above-described display device substrate will be described. FIG. 3 shows a cross-sectional structure around each organic EL element electrode shown in FIG. In the first substrate forming step, a light transmissive insulating substrate 1 is prepared. The insulating substrate 1 is a glass plate or the like having a base surface serving as a barrier for preventing diffusion of silicon, and the base surface is made of, for example, a laminate of a silicon nitride film and a silicon oxide film covering the silicon nitride film. Subsequently, for example, top gate type polysilicon thin film transistors are formed on the insulating substrate 1 as thin film transistors 5 and 6. In the thin film transistors 5 and 6, a polysilicon semiconductor thin film 10 is formed on the base surface of the insulating substrate 1, a silicon oxide gate insulating film 11 is formed covering the semiconductor thin film 10, and the gate insulating film 11 is covered, for example, MoW. A metal layer is formed, the MoW metal layer is patterned while leaving the gate electrode G facing the semiconductor thin film 10 through the gate insulating film 11, and an impurity having a predetermined concentration is formed in the semiconductor thin film 10 using the gate electrode G as a mask. To form a source and a drain.
[0015]
The inspection electrode PT includes a first electrode of the capacitive element 7 connected to the gate electrode G of the thin film transistor 5 in the patterning process of the MoW metal layer, a scanning line Y connected to the gate electrode G of the thin film transistor 6, and an inspection power supply terminal Vtest and It is formed together with the wiring connecting the inspection electrodes PT. Subsequently, an interlayer insulating film 12 made of silicon oxide is formed so as to cover the gate insulating film 11, the inspection electrode PT, the gate electrode G, the scanning line Y, the first electrode of the capacitive element 7, and further, ITO (Indium Tin Oxide) or the like. The light transmissive electrode material layer is formed so as to cover the interlayer insulating film 12. The light transmissive electrode material layer is patterned so as to leave the organic EL element electrode PX. The organic EL element electrode PX is once covered with a resist mask, and a plurality of contact holes are formed by exposing the sources and drains of the thin film transistors 5 and 6. Subsequently, the source electrode S, the drain electrode D, the signal line X, and the second electrode of the capacitor element 7 facing the first electrode of the capacitor element 7 are connected to the power supply terminal Vdd, and the Vdd side power source line is Mo / Al. It is formed on the interlayer insulating film 12 as a metal layer having a three-layer structure such as / Mo. Here, the source electrode S and the drain electrode D of the thin film transistors 5 and 6 are connected to the sources and drains of the thin film transistors 5 and 6 through contact holes. The source electrode S of the thin film transistor 5 is connected to the organic EL element electrode PX, and the drain electrode D of the thin film transistor 5 is connected to the Vdd side power supply line. The source electrode S of the thin film transistor 6 is connected to the first electrode of the capacitor 7 through the contact hole, and the drain electrode D of the thin film transistor 6 is connected to the signal line X.
[0016]
In this state, a protective insulating film 13 made of silicon nitride is formed so as to entirely cover the organic EL element electrode PX, the source electrode S, the drain electrode D, and the interlayer insulating film 12, and the organic EL element electrode PX is partially exposed. Patterning is performed. Subsequently, a patterning process is performed so that the insulating film 14, for example, a silicon oxide film is formed so as to entirely cover the exposed portions of the protective insulating film 13 and the organic EL element electrode PX, and the organic EL element electrode PX is partially exposed again. Is done. Subsequently, the surface-treated organic insulating film 15, for example, acrylic resin is formed so as to cover the insulating film 14 and the exposed portion of the organic EL element electrode PX, and the organic EL element electrode PX is partially exposed again. Patterning is performed. In these patterning processes, the organic EL element electrode PX is partially exposed, and the opening OP that is tapered toward the exposed surface is formed on the insulator of the protective insulating film 13, the hydrophilic insulating film 14, and the water-repellent organic insulating film 15. Will form. Thus, the substrate forming process is completed.
[0017]
In the subsequent substrate inspection process, the display device substrate is inspected for the amount of charge held in the capacitance Ctest between the plurality of organic EL element electrodes PX and the plurality of inspection electrodes PT, and the defective substrate is removed based on the inspection result. The Here, a predetermined inspection voltage is applied between the power supply terminal Vdd and the inspection power supply terminal Vtest, and electric charges are held in the entire capacitance between the plurality of organic EL element electrodes PX and the plurality of inspection electrodes PT under the control of the current control circuit 4. For example, a defect of the display device substrate is detected using an electron beam tester. This electron beam tester captures a secondary emitted electron beam by irradiating the electron beam onto the display device substrate, and displays the potential distribution of the plurality of organic EL element electrodes PX depending on the accumulated charge amount of the capacitor Ctest as an image. To do. The inspector observes this image, confirms whether the operation of the current control circuit 4 including the thin film transistor 5 is normal, and identifies a defective substrate. Further, instead of using an electron beam tester, the charge is sequentially held in the capacitors Ctest between the plurality of organic EL element electrodes PX and the plurality of test electrodes PT, and the charge amount of each capacitor Ctest is measured from the test power supply terminal Vtest. You may detect the defect of a display apparatus board | substrate using a circuit.
[0018]
In the subsequent pixel formation process, it was determined that the plurality of organic EL elements OLED remained unremoved in the substrate inspection process as shown in FIG. 4 or were normal in the substrate inspection process by repairing defective portions. It is formed using a display device substrate. This organic EL element OLED has a structure in which an organic material layer 16 is sandwiched between a pair of a cathode electrode 17 and an anode electrode 18. Here, the organic EL element electrode PX is used as the anode electrode 18 described above. The organic material layer 16 is configured by stacking, for example, a light emitting layer EM, a buffer layer 19, and an electron transport layer 20. The light emitting layer EM is a thin film containing a red, green, or blue fluorescent organic compound. The buffer layer 19 is formed between the light emitting layer EM and the anode electrode 18, and the electron transport layer 20 is formed between the light emitting layer EM and the cathode electrode 17. The anode electrode 18 is a light transmissive electrode made of, for example, ITO, and the cathode electrode 17 is a reflective electrode made of a metal such as Ba. The cathode electrode is configured to be covered with a protective layer 21 such as Ag.
[0019]
In the actual pixel formation process, for example, a certain amount of water-soluble polymer solution is injected into the opening OP by the ink jet method, thereby forming the buffer layer 19. Thereafter, a polymer solution containing a certain amount of the fluorescent organic compound is injected into the opening OP by an ink jet method, thereby forming the light emitting layer EM. Thereafter, a certain amount of polymer solution is injected into the opening OP by an ink jet method, thereby forming the electron transport layer 20. The water repellent insulating film 15 and the electron transport layer 20 are covered with a cathode electrode 17 and a protective layer 21 formed by metal deposition. The cathode electrode 17 is connected to the power supply terminal Vss independently of the inspection power supply terminal Vtest on the display device substrate. The structure thus obtained is adhered to a support plate 22 such as a glass plate or a metal plate in a nitrogen atmosphere by a sealing material applied in the vicinity of the outer peripheral edge thereof, whereby nitrogen is bonded to the protective layer 21 and the support plate 22. It is sealed between.
[0020]
The organic EL element OLED described above excites organic molecules constituting the light emitting layer EM when holes injected from the anode electrode AD and electrons injected from the cathode electrode 17 recombine inside the light emitting layer EM. To generate excitons. The excitons emit light in the process of radiation deactivation, and the light is emitted from the light emitting layer EM to the outside through the light-transmitting anode electrode 18, the interlayer insulating film 12, the gate insulating film 11, and the insulating substrate 1. The organic material layer 16 can be constituted not only by the three-layer structure as described above, but also by two layers or a single layer functionally combined so as to emit light. Further, the electron transport layer 20 can be omitted. Further, in this embodiment, the anode electrode 18 is a light transmissive electrode, and light is taken out through the light transmissive electrode. The cathode electrode 17 is a light transmissive electrode, and the anode electrode 18 is a light reflective electrode. The light may be extracted outside from the cathode electrode 17 side.
[0021]
FIG. 5 shows a pixel peripheral circuit of the organic EL display device formed by the above-described manufacturing method. In the substrate forming process, since the organic EL element OLED is not formed except for the organic EL element electrode PX that becomes the anode electrode 18, a thin film transistor that becomes a driving element of the organic EL element OLED by applying a power supply voltage between the power supply terminals Vdd and Vss. The operation of 5 cannot be confirmed. Instead, the inspection electrode PT is capacitively coupled to the organic EL element electrode PX and connected to the inspection power supply terminal Vtest. Thereby, an inspection voltage is applied between the power supply terminal Vdd and the inspection power supply terminal Vtest, and electric charges can be accumulated in the capacitor Ctest between the organic EL element electrode PX and the inspection electrode PT by the current Id flowing through the thin film transistor 5. . The potential of the organic EL element electrode PX depends on the electric charge accumulated in the capacitor Ctest, whereby the test voltage is a voltage Vf corresponding to the capacitor Ctest and a voltage Vds corresponding to the thin film transistor 5 with reference to the potential of the test power supply terminal Vtest. The pressure will be divided. Therefore, the operation of the thin film transistor 5 can be confirmed by observing the potential of the organic EL element electrode PX. Even if the thin film transistor 5 is not defective, a state in which at least one of the scanning line driving circuit 2, the signal line driving circuit 3, and the current control circuit 4 is defective is detected, so that a defective substrate can be specified.
[0022]
In the above-described embodiment, the plurality of organic EL element electrodes PX on the insulating substrate 1 so that the plurality of inspection electrodes PT respectively hold the inspection charges controlled by the plurality of thin film transistors 5 serving as driving elements of the organic EL element OLED. Are coupled to the inspection power supply terminal Vtest. As a result, the display device substrate is inspected using an electron beam tester or the like for the amount of charge held in the capacitance Ctest between the plurality of organic EL element electrodes PX and the plurality of inspection electrodes PT, and the defective display device substrate is removed. Is possible. That is, since only a normal display device substrate is used to form a plurality of organic EL elements OLED, the yield of products can be improved. In this case, it is possible to prevent an increase in manufacturing cost due to processing time and materials that are wasted due to a defective substrate, and the overall productivity is improved. In conclusion, it is important to provide a test electrode that is capacitively coupled to a wiring electrode connected to a driving element of a self-luminous element such as an organic EL element, and to form a capacitance between the wiring electrode and the test electrode.
[0023]
In addition, this invention is not limited to the above-mentioned embodiment, It can deform | transform variously in the range which does not deviate from the summary.
[0024]
FIG. 6 shows a first modification of the circuit configuration shown in FIG. In the above-described embodiment, the inspection power supply terminal Vtest is formed independently of the power supply terminal Vss. However, the inspection power supply terminal Vtest may be shared as the power supply terminal Vss. In the case of this configuration, it is preferable to cut the wiring between the inspection power supply terminal Vtest and the inspection electrode PT after the substrate inspection step, for example, as shown in FIG. By doing this, it is possible to avoid the capacitance Ctest from affecting the operation of the finished organic EL display device as a parasitic capacitance parallel to the organic EL element OLED. In addition, each current control circuit 4 may be configured to include a known threshold cancellation circuit including switches SW1 and SW2 and a capacitor element CK connected as shown in FIG. 6, for example. As a result, it is possible to control the current flowing through the organic EL element OLED without being affected by the variation in threshold between the plurality of thin film transistors 6.
[0025]
FIG. 7 shows a second modification of the circuit configuration shown in FIG. In the above-described embodiment, each of the plurality of test electrodes PT is capacitively coupled to the corresponding organic EL element electrode PX as shown in FIG. 7 and connected to the test power supply terminal Vtest. It may be connected between the corresponding organic EL element electrode PX and the inspection power supply terminal Vtest. In the substrate inspection process, the display device substrate is inspected for the current flowing through these inspection resistors Rtest, and the defective substrate is removed based on the inspection result. In the case of this configuration, either the wiring between the inspection power supply terminal Vtest and the inspection resistor Rtest or the wiring between the inspection resistor Rtest and the organic EL element electrode PX is shown in FIG. Need to be cut. By doing this, the test resistor Rtest does not form a current path parallel to the organic EL element OLED and does not affect the operation of the finished organic EL display device.
[0026]
In the above-described embodiment, the display device substrate used as a manufacturing component of the bottom emission type organic EL display device has been described. However, the present invention is a display device substrate used as a manufacturing component of the top emission type organic EL display device. It can also be applied to. In this top emission type organic EL display device, since the light emitted from the organic EL element OLED is emitted from the upper surface without passing through the insulating substrate 1, the light transmitted through the organic EL element electrode PX is not blocked. There is no need to arrange the inspection electrode PT. Therefore, for example, the inspection electrode PT may be disposed below the center portion of the organic EL element electrode PX, and the inspection electrode PT and the organic EL element electrode PX may be capacitively coupled.
[0027]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a display device substrate capable of performing an inspection for finding a defective substrate before forming a self-light-emitting element, and a display device manufacturing method using the display device substrate. .
[Brief description of the drawings]
FIG. 1 is a diagram generally showing a circuit configuration of a display device substrate according to an embodiment of the present invention.
FIG. 2 is a diagram showing a planar structure around the organic EL element electrodes for three adjacent pixels in FIG.
3 is a view showing a cross-sectional structure around each organic EL element electrode shown in FIG. 2;
4 is a view showing a cross-sectional structure of an organic EL element formed on a display device substrate having a cross-sectional structure shown in FIG.
5 is a diagram showing a pixel peripheral circuit of an organic EL display device completed by forming the organic EL element shown in FIG. 4. FIG.
6 is a diagram showing a first modification of the pixel peripheral circuit shown in FIG. 5. FIG.
7 is a diagram showing a second modification of the pixel peripheral circuit shown in FIG. 5. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Insulating substrate 4 ... Current control circuit 5 ... Current drive thin film transistor 6 ... Pixel switch thin film transistor 7 ... Capacitance element PX ... Organic EL element electrode PT ... Test electrode Vdd, Vss ... Power supply terminal Vtest ... Test power supply terminal

Claims

An insulating substrate; first and second power supply terminals formed on the insulating substrate; a plurality of self-light-emitting element electrodes arranged in a substantially matrix on the insulating substrate; and the plurality of self electrodes on the insulating substrate. A plurality of driving elements connected between the light emitting element electrode and the first power supply terminal, and the plurality of self-light emitting element electrodes on the insulating substrate so as to hold inspection charges controlled by the plurality of driving elements. Forming a display device substrate including a plurality of test electrodes that are capacitively coupled to each other and connected to the second power supply terminal,
A substrate inspection step of inspecting the display device substrate and removing the defective display device substrate for the amount of charge held in the capacitance between the plurality of self-luminous element electrodes and the plurality of inspection electrodes;
A pixel forming step of forming a plurality of self-luminous elements using a display device substrate remaining without being removed in the substrate inspection step,
Each of the plurality of self-light-emitting elements includes a first electrode composed of a corresponding self-light-emitting element electrode, a light-emitting member layer formed on the first electrode, and a second electrode formed on the light-emitting member layer, The pixel forming step includes a step of separating the plurality of inspection electrodes from the second power supply terminal and connecting the second electrodes of the plurality of self-light-emitting elements to the second power supply terminal.

Each self-light emitting element electrode is formed of a light-transmissive electrode material layer that emits light through the insulating substrate, and each inspection electrode is formed to face an end of the corresponding self-light emitting element electrode. Item 4. A display device manufacturing method according to Item 1.

Each driving element, together with a pixel switch that captures a display signal in a conductive state and supplies it to the driving element as a control voltage, and a capacitive element that holds the control voltage supplied to the driving element when the pixel switch is in a non-conductive state The display device manufacturing method according to claim 1, comprising a current control circuit.

The display device manufacturing method according to claim 3, wherein the pixel switch and the driving element are formed of thin film transistors.

The display device manufacturing method according to claim 4, wherein the current control circuit includes a threshold cancel circuit that cancels a threshold of a thin film transistor of the driving element.

The display device manufacturing method according to claim 1, wherein each self-light emitting element electrode is formed as one of an anode electrode and a cathode electrode of an organic EL element.

A plurality of scanning lines formed along a row of the plurality of self-light emitting element electrodes, each controlling a current control circuit in a corresponding row, and a current control of each corresponding column formed along a column of the plurality of self-light emitting element electrodes. The display device manufacturing method according to claim 3, further comprising a plurality of signal lines for supplying display signals to the circuit on the insulating substrate.

The display device manufacturing method according to claim 7, further comprising a driving circuit for driving the plurality of scanning lines and the plurality of signal lines on the insulating substrate.

In the substrate inspection step, a charge is held in the entire capacitance between the plurality of self-luminous element electrodes and the plurality of inspection electrodes, and the electron beam emitted secondarily is captured by irradiating the display device substrate with the electron beam. The method for manufacturing a display device according to claim 1, further comprising a step of detecting a defect of the display device substrate using an electron beam tester that displays the potential distribution of the plurality of self-light emitting element electrodes as an image.

In the substrate inspection step, the display device substrate is configured using an integration circuit that sequentially holds charges in the capacitors between the plurality of self-light emitting element electrodes and the plurality of inspection electrodes and measures the charge amount of each capacitor from a second power supply terminal. The display device manufacturing method according to claim 1, further comprising a step of detecting a defect of the display device.

The plurality of driving elements are each composed of a polysilicon thin film transistor, and the substrate forming step includes a single film forming process for simultaneously forming a gate electrode and the plurality of inspection electrodes of the polysilicon thin film transistor. The display device manufacturing method according to claim 1.