JP4164321B2 - Ink jet recording head manufacturing method, ink jet recording head, and ink jet recording apparatus - Google Patents

Description

【００３１】
次に、図４（ａ）および（ｂ）のように吐出口５を形成する。本例の場合、被覆樹脂層４は、光カチオン重合開始剤を含み、ネガ型の感光特性が付与されているため、フォトリソグラフィーによって吐出口５を形成する。すなわち、キャノン製マスクアライナーＭＰＡ６００を用い、マスクを介してパターン露光（露光時間５０秒）を行い、次いで９０℃の温度で４分間加熱処理を行った後に、現像処置を施して吐出口５を形成した。吐出口５の径は、φ２０μｍに形成した。
【００３２】
次に、シリコン基板１の裏面から、マスクを介してシリコンの異方性エッチングを行い、図５（ａ）および（ｂ）のようなインク供給口６を形成した。
【００３３】
次に、現工程において残存しているインク流路パターン３を全面露光により分解した後、図６（ａ）および（ｂ）のように、それを乳酸メチルによって除去した。
【００３４】
その後、被覆樹脂層４を完全に硬化させるために、２００℃の温度で１時間の加熱処理をしてから、電気的接続およびインク供給部材を配置して、インクジェット記録ヘッドを完成させた。
【００３５】
このように製作された本実施例の記録ヘッドの比較対象として、被覆樹脂層４の回転塗布の終了後に、それを減圧下に保持せずに、常圧下において９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行ったサンプルを作成した。そのサンプルに対する処理において、被覆樹脂層４の回転塗布終了後に減圧下での保持がない以外は、上述した実施例の記録ヘッドに対する処理と同様である。
【００３６】
本実施例の記録ヘッド、つまり被覆樹脂層４の回転塗布終了後に減圧下において保持された記録ヘッドの場合、所定パターンの画像を記録する記録検査の結果、歩留まりは９５％であった。不良の５％について解析を行ったところ、顕微鏡観察では、ゴミ等は検出されず原因は特定できなかった。
【００３７】
一方、比較対象としてのサンプル、つまり被覆樹脂層４の回転塗布終了後に減圧下に保持しなかった記録ヘッドの場合、本実施例の記録ヘッドと同様の記録検査の結果、歩留まりは８１％であった。不良の１９％について解析を行ったところ、顕微鏡観察においては、薄膜状のゴミによる不良が１３％、ゴミ等は検出されずに原因が特定できなかったものが６％であった。その薄膜状のゴミは、インク流路パターン３と被覆樹脂層４の相溶物と考えられる。
【００３８】
（第１の実施形態の実施例２）
本実施例では、２４μｍ角の電気熱変換素子２を２列配した。その電気熱変換素子２は３００ノズル分配置され、その配備形態は、６００ＤＰＩのピッチで２列、かつ千鳥状に配されており、記録ヘッドとして１２００ＤＰＩの３００ノズルが形成できるようになっている。なお、基板１は、シリコン基板用素材に２５０チップ分配列される。
【００３９】
このような基板１を用いて、前述した実施例１と同様の方法によって記録ヘッドを作成した。ただし、塗布溶媒としてキシレンを用い、前述した表１の被覆樹脂組成物を４５ｗｔ％の濃度で溶解して、スピンコートにより、インク流路パターン３上に塗布した。その塗布は、被覆樹脂層４が１２μｍとなるように、スピン回転数を調整しながら行う。その回転塗布の終了後、１０ｃｍＨｇの減圧下において、４０℃の温度で３分間保持してから、最後に常圧下にて９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行った。なお、吐出口５の径は、φ１５μｍとした。
【００４０】
このように製作された本実施例の記録ヘッドの比較対象として、被覆樹脂層４の回転塗布の終了後に、減圧下に保持せずに、常圧下において９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行ったサンプルを作成した。
【００４１】
本実施例の記録ヘッド、つまり被覆樹脂層４の回転塗布終了後に減圧下において保持された記録ヘッドの場合、所定パターンの画像を記録する記録検査の結果、歩留まりは９３％であった。不良の７％について解析を行ったところ、顕微鏡観察では、２％の記録ヘッドに糸状のゴミ等が検出され、残りの記録ヘッドに関してはゴミ等が検出されず原因は特定できなかった。その糸状のゴミは、組立て工程中に混入したと思われるゴミであり、前述した実施例１の比較例としてのサンプルにおいて検出された薄膜状のゴミとは明らかに形態が異なっていた。
【００４２】
一方、比較対象としてのサンプル、つまり被覆樹脂層４の回転塗布終了後に減圧下に保持しなかった記録ヘッドの場合、本実施例の記録ヘッドと同様の記録検査の結果、歩留まりは８５％であった。不良の１５％について解析を行ったところ、顕微鏡観察においては、薄膜状のゴミによる不良が１０％、ゴミ等は検出されずに原因が特定できなかったものが５％であった。その薄膜状のゴミは、インク流路パターン３と被覆樹脂層４の相溶物と考えられる。
【００４３】
（第１の実施形態の実施例３）
本実施例では、前述した実施例１と同様に記録ヘッドを作成した。ただし、塗布溶媒として、メチルイソブチルケトン／ジグライム＝１／１（ｗｔ）を用い、下表２の被覆樹脂組成物を５０ｗｔ％の濃度で溶解して、スピンコートにより、インク流路パターン３上に塗布した。その塗布は、被覆樹脂層４が１２μｍとなるように、スピン回転数を調整しながら行う。その回転塗布の終了後、５ｃｍＨｇの減圧下において、４０℃の温度で３分間保持してから、最後に常圧下にて９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行った。なお、吐出口５の径は、φ２０μｍとした。また、その吐出口５の形成に際しては、露光時間を６０秒とした。
【００４４】
【表２】

【００４５】
このように製作された本実施例の記録ヘッドの比較対象として、被覆樹脂層４の回転塗布の終了後に、減圧下に保持せずに、常圧下において９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行ったサンプルを作成した。
【００４６】
本実施例の記録ヘッド、つまり被覆樹脂層４の回転塗布終了後に減圧下において保持された記録ヘッドの場合、所定パターンの画像を記録する記録検査の結果、歩留まりは８２％であった。不良の１８％について解析を行ったところ、顕微鏡観察では、薄膜状のゴミ等は検出されなかった。
【００４７】
一方、比較対象としてのサンプル、つまり被覆樹脂層４の回転塗布終了後に減圧下に保持しなかった記録ヘッドの場合、本実施例の記録ヘッドと同様の記録検査の結果、歩留まりは７５％であった。不良の２５％について解析を行ったところ、顕微鏡観察において、薄膜状のゴミによる不良が１８％検出された。その薄膜状のゴミは、インク流路パターン３と被覆樹脂層４の相溶物と考えられる。
【００４８】
以上の実施例１，２，３から明らかなように、塗布溶媒の種類に拘わらず、被覆樹脂層４の回転塗布終了後に減圧下に保持した記録ヘッドと、被覆樹脂層４の回転塗布終了後に減圧下に保持しなかった記録ヘッドの記録検査の結果、インク流路パターン３と被覆樹脂層４の相溶物と考えられる薄膜状のゴミの出現率に大きな差が生じて、歩留まりに差が生じた。
【００４９】
（第２の実施形態）
以下、本発明の第２の実施形態について説明する。
【００５０】
本実施形態は、前述した第１の実施形態と同様に、図１から図６と同様の手順によって記録ヘッドを製造する。本実施形態は、図３（ａ）および（ｂ）の製造段階、つまり、エポキシ樹脂を含む被覆樹脂を溶媒に溶解し、スピンコート等のソルベントコート法によって、それをインク流路パターン３上に塗布して被覆樹脂層４を形成する製造段階において、その被覆樹脂層４の膜厚精度の観点から、その塗布溶媒を選定した。
【００５１】
すなわち、まず、インク流路パターン３は、多くの場合１０μｍ以上の膜厚を有するため、被覆樹脂層４は、少なくとも１０μｍ以上の凹凸を吸収して、その表面がフラットになるように形成しなければならない。図３（ａ）および（ｂ）において、電気熱変換素子２上のインク流路パターン３の膜厚と被覆樹脂層４の膜厚との合計分の距離Ｌは、前述したＯＨ距離、つまり電気熱変換素子２とオリフィス（インク吐出口の形成面）との間の距離となり、前述したように、ノズル毎の特性のばらつきを抑える上において、そのＯＨ距離を正確に設定することが重要となる。前者のインク流路パターン３の膜厚管理に関しては、基本的にほぼフラットな基板１上にインク流路パターン３を形成するため、通常のスピンコート法等によって充分な膜厚精度を出すことができる。問題は、後者の被覆樹脂層４の膜厚管理である。
【００５２】
前述した特開平６−２８６１４９号公報には、溶解可能な樹脂によって形成されたインク流路パターン３上に、エポキシ樹脂を含む被覆樹脂層４を形成する際に、被覆樹脂を濃度３０〜７０ｗｔ％で塗布溶媒に溶解し、それをソルベントコートによって形成する方法が記載されている。本発明者による詳細な検討の結果、より高精度に被覆樹脂層４の膜厚を管理するためには、被覆樹脂の固形分濃度と併せて、塗布溶媒の選定の必要性が判明した。塗布溶媒の選定に当たっては、考慮しべき事項として、溶解可能な流路パターン３を溶解、変形させないこと、およびエポキシ樹脂を含む被覆樹脂を必要な固形分濃度まで溶解させること等、厚膜の精度以外にも考慮するべき事項がある。本発明者の検討によれば、塗布溶媒として、２−エトキシエタノール（商品名：エチルセルソルブ）が最適であることが判明した。
【００５３】
以下、本発明の第２の実施形態における具体的な実施例について説明する。
【００５４】
（第２の実施形態の実施例１）
本実施例では、前述した図１から図６に示される手順にしたがって、インクジェット記録ヘッドを製作した。まず、シリコン基板１上に、図１に示すような形態で、３０μｍ角の電気熱変換素子（窒化タンタル ＴａＮ）２を２列配した。電気熱変換素子２は２５６ノズル分配置され、その配備形態は、３００ＤＰＩのピッチで２列、かつ千鳥状に配されており、記録ヘッドとして６００ＤＰＩの２５６ノズルが形成できるようになっている。なお、基板１は、シリコン基板用素材に２００チップ分配列される。
【００５５】
次に、図２（ａ）および（ｂ）のような溶解可能なインク流路パターン３を形成するために、ポジ型レジストＯＤＵＲ１０１０（東京応化工業社製）をスピンコートを用いて塗布し、成膜した。その後、キャノン製マスクアライナーＰＬＡ６２０（ｄｅｅｐ ＵＶ対応）により、マスクを介してパターン露光（露光時間３分）を行い、それから現像処理を行ってインク流路パターン３を形成した。そのインク流路パターン３の設計形状は、図７（図１のＢ―Ｂ′線に沿う断面図に相当）のとおりであり、幅が３３μｍ、、膜厚が１３μｍである。また、電気熱変換素子２の幅は３０μｍ、隣接する電気熱変換素子２の間隔は８４．５μｍである。
【００５６】
１つの基板（１チップ）１内の１０ノズルのインク流路パターン３の膜厚を１０個の基板分（１０チップ分）、つまり計１００ノズル分のインク流路パターン３の膜厚を膜厚計（λエース）によって測定した結果、その膜厚平均が１３．１μｍ（バラツキは、σ＝０．１μｍ）となり、ほぼ均一な膜厚に形成されていることが確認できた。
【００５７】
次に、図３（ａ）、（ｂ）のような被覆樹脂層４を形成するために、下表３の被覆樹脂組成物を、塗布溶媒としての２−エトキシエタノールに５０ｗｔ％の濃度で溶解し、それをスピンコートによりインク流路パターン３上に塗布した。その塗布は、被覆樹脂層４が１２μｍとなるように、スピン回転数を調整しながら行う。その後、９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行った。
【００５８】
【表３】

【００５９】
次に、図４（ａ）および（ｂ）のように吐出口５を形成する。本例の場合、被覆樹脂層４は、光カチオン重合開始剤を含み、ネガ型の感光特性が付与されているため、フォトリソグラフィーによって吐出口５を形成する。すなわち、キャノン製マスクアライナーＰＬＡ６２０を用い、マスクを介してパターン露光（露光時間４秒）を行い、次いで９０℃の温度で３分間加熱処理を行った後に、現像処置を施して吐出口５を形成した。吐出口５の径は、φ２０μｍに形成した。
【００６０】
次に、シリコン基板１の裏面から、マスクを介して、シリコンの異方性エッチングを行い、図５（ａ）および（ｂ）のようなインク供給口６を形成した。次に、現工程において残存しているインク流路パターンを全面露光により分解した後、図６（ａ）および（ｂ）のように、それを乳酸メチルによって除去した。その後、被覆樹脂層４を完全に硬化させるために、２００℃の温度で１時間の加熱処理をした。
【００６１】
このようにしてノズル構造を成した後、干渉膜厚計（Zygo new view 200）を用いて、電気熱変換素子２と吐出口５の形成面との間のＯＨ距離を測定した。そのＯＨ距離の測定個所は、１つの基板（１チップ）１内の１０ノズルを１０個の基板分（１０チップ分）、つまり計１００ノズル分とした。その１００ノズル分のＯＨ距離の平均は、２５．０μｍ（バラツキは。σ＝０．０４μｍ）であった。
【００６２】
このような本実施例のノズル構造の比較対象として、被覆樹脂の塗布溶媒として、２−エトキシエタノールに代えて、前述した特開平６−２８６１４９号公報の実施例１に記載されているメチルイソブチルケトン／キシレン＝１／１（重量部）を用いて、被覆樹脂層４を形成した。その比較対象のサンプルのＯＨ距離を前述した測定方法により測定した結果、その平均が２４．９μｍ（バラツキは、σ＝０．９μｍ）であった。上述した本発明の実施例におけるＯＨ距離の平均値と、その比較対象のサンプルにおけるＯＨ距離の平均値は、両者共に、ほぼ設計値の２５μｍに形成されてはいるものの、ＯＨ距離のバラツキσの値は、後者の比較対象のサンプルに比して、前者の本発明の実施例の場合の方が半分以下に低減していることが確認できた。
【００６３】
さらに、前者の本発明の実施例におけるノズル構造と、後者の比較対象のサンプルにおけるノズル構造のぞれぞれに対して、電気的接続およびインクタンク供給部材を配置して記録ヘッドを構成して、それらの両者の記録ヘッドからインク滴を吐出した。そして、両者の記録ヘッドのそれぞれに対して、１つの記録ヘッド当たり１ノズルからのインク滴の吐出量を１０個の記録ヘッド分測定した結果、前者の本発明の実施例の記録ヘッドにおけるインク滴の吐出量の平均値は８．５ピコリットル、バラツキは±０．３ピコリットルであった。一方、後者の比較対象のサンプルにおけるインク滴の吐出量の平均値は８．５ピコリットル、バラツキは±０．６ピコリットルであった。これら両者の比較から明らかなように、本発明の実施例のように塗布溶媒として２−エトキシエタノール（エチルセルソルブ）を用いた記録ヘッドは、ＯＨ精度のバラツキの低減を反映して、インク滴の吐出量のバラツキを小さく抑えることができる。
【００６４】
（第２の実施形態の実施例２）
本実施例では、前述した図１から図６に示される手順にしたがって、インクジェット記録ヘッドを製作した。まず、シリコン基板１上に、図１に示すような形態で、２４μｍ角の電気熱変換素子（窒化タンタル ＴａＮ）２を２列配した。電気熱変換素子２は３００ノズル分配置され、その配備形態は、６００ＤＰＩのピッチで２列、かつ千鳥状に配されており、記録ヘッドとして１２００ＤＰＩの３００ノズルが形成できるようになっている。なお、基板１は、シリコン基板用素材に２５０チップ分配列される。
【００６５】
次に、上述した実施例１と同様にして、図２（ａ）および（ｂ）のような溶解可能な樹脂によってインク流路パターン３を形成した。そのインク流路パターン３の設計形状は、図８（図１のＢ―Ｂ′線に沿う断面図に相当）のとおりであり、幅が３０μｍ、膜厚が１３μｍである。また、電気熱変換素子２の幅は２４μｍ、隣接する電気熱変換素子２の間隔は４２．５μｍである。
【００６６】
１つの基板（１チップ）１内の１０ノズルのインク流路パターン３の膜厚を１０個の基板分（１０チップ分）、つまり計１００ノズル分のインク流路パターン３の膜厚を膜厚計（λエース）によって測定した結果、その膜厚平均が１３．０μｍ（バラツキは、σ＝０．１μｍ）となり、ほぼ均一な膜厚に形成されていることが確認できた。
【００６７】
次に、図３（ａ）、（ｂ）のような被覆樹脂層４を形成するために、下表４の被覆樹脂組成物を、塗布溶媒としての２−エトキシエタノールに５０ｗｔ％の濃度で溶解し、それをスピンコートによりインク流路パターン３上に塗布した。その塗布は、被覆樹脂層４が１２μｍとなるように、スピン回転数を調整しながら行う。その後、９０℃の温度で３分間ベークして、塗布溶媒の乾燥を行った。
【００６８】
【表４】

【００６９】
次に、図４（ａ）および（ｂ）のように吐出口５を形成する。本例の場合、被覆樹脂層４は、光カチオン重合開始剤を含み、ネガ型の感光特性が付与されているため、フォトリソグラフィーによって吐出口５を形成する。すなわち、キャノン製マスクアライナーＭＰＡ６００を用い、マスクを介してパターン露光（露光時間６０秒）を行い、次いで９０℃の温度で３分間加熱処理を行った後に、現像処置を施して吐出口５を形成した。吐出口５の径は、φ１５μｍに形成した。
【００７０】
次に、シリコン基板１の裏面から、マスクを介して、シリコンの異方性エッチングを行い、図５（ａ）および（ｂ）のようなインク供給口６を形成した。次に、現工程において残存しているインク流路パターンを全面露光により分解した後、図６（ａ）および（ｂ）のように、それを乳酸メチルによって除去した。その後、被覆樹脂層４を完全に硬化させるために、２００℃の温度で１時間の加熱処理をした。
【００７１】
このようにしてノズル構造を成した後、干渉膜厚計（Zygo new view 200）を用いて、電気熱変換素子２と吐出口５の形成面との間のＯＨ距離を測定した。そのＯＨ距離の測定個所は、１つの基板（１チップ）１内の１０ノズルを１０個の基板分（１０チップ分）、つまり計１００ノズル分とした。その１００ノズル分のＯＨ距離の平均は、２５．０μｍ（バラツキは、σ＝０．３μｍ）であった。
【００７２】
さらに、このようなノズル構造に対して、電気的接続およびインクタンク供給部材を配置して記録ヘッドを構成して、その記録ヘッドからインク滴を吐出した。そして、１つの記録ヘッド当たり１ノズルからのインク滴の吐出量を１０個の記録ヘッド分測定した結果、インク滴の吐出量の平均値は５．０ピコリットル、バラツキは±０．２ピコリットルであった。このように１ノズル当たりのインク吐出量が５ピコリットルの微小量であるにも拘わらず、そのバラツキをきわめて小さい範囲に抑えることができた。
【００７３】
以上の実施例１，２において、前述した本発明の第１の実施形態と同様に、被覆樹脂層４の塗布終了後に減圧下に保持することにより、薄膜状のゴミの出現率を抑えて、記録ヘッドの製造上の歩留まりを向上させることもできる。これらの組合せの相乗効果により、記録ヘッドの信頼性を大幅に向上させることができる。
【００７４】
（インクジェット記録ヘッド全体の構成例）
図９は、本発明のインクジェット記録ヘッドの全体的な構成例を説明するための斜視図である。
【００７５】
図９において、２は、前述した第１、第２の実施形態におけるノズル構造を成す素子基板であり、２列に配列された複数の吐出口４が千鳥状に設けられている。素子基板２は、Ｌ字状に加工された支持部材１０２の一部に接着固定されている。この支持部材１０２上に固定された配線基板１０４の配線部分と、素子基板２における配線部分は、ボンディングにより電気的に接続されている。支持部材１０２は、コストおよび加工性等の観点から、アルミニウム材によって形成される。モールド部材１０３は、その内部に支持部材１０２の一部を挿入して、その支持部材１０２を支持すると共に、その内部に形成されたインク供給路を介して、インク貯留部から、前述したインク供給口６にインクを供給するための部材である。また、モールド部材１０３は、本例の記録ヘッド全体をインクジェット記録装置に着脱自在に固定するための装着、位置決め部材としての役割を果たす。
【００７６】
（インクジェット記録装置の構成例）
図１０は、本発明のインクジェット記録ヘッドを使用可能なシリアルタイプのインクジェット記録装置の概略斜視図である。
【００７７】
図１０において、２００は、上述した本発明のインクジェット記録ヘッドが着脱自在に装着されるキャリッジである。本例の場合、記録ヘッドは、インク色の種類に応じて４種類装着され、イエローインクのタンク２０１Ｙ、マゼンタインクのタンク２０１Ｍ、シアンインクのタンク２０１Ｃ、ブラックインクのタンク２０１Ｂと共に、キャリッジ２００上に搭載される。
【００７８】
キャリッジ２００は、ガイドシャフト２０２に支持され、モータ２０３により順方向または逆方向に駆動される無端ベルト２０４により、ガイドシャフト２０２に沿って矢印Ａ方向（主走査方向）に往復移動される。無端ベルト２０４は、プーリ２０５，２０６間に架け渡されている。
【００７９】
被記録媒体としての記録紙Ｐは、矢印Ａ方向と直交する矢印Ｂ方向（副走査方向）に間欠的に搬送される。記録紙Ｐは、上流側の一対のローラユニット２０７，２０８と、下流側の一対のローラユニット２０９，２１０とによって挟持され、かつ一定の張力が印加されて、記録ヘッドに対する平面性を確保しながら搬送される。各ローラユニットに対する駆動力は、駆動部２１１から付与される。また、各ローラユニットは、モータ２０３によって駆動する構成としてもよい。
【００８０】
キャリッジ２００は、記録開始または記録動作中に、必要に応じてホームポジッションに停止する。このポジッションには、各記録ヘッドの吐出口面をキャップするキャップ部材２１２が設けられている。キャップ部材２１２には、吐出口面に開口する吐出口から画像の記録に寄与しないインクを強制的に吸引して、吐出口内の目詰まりを防止するための吸引回復手段が接続されている。
【００８１】
（その他）
なお、本発明は、特にインクジェット記録方式の中でも、インク吐出を行わせるために利用されるエネルギとして熱エネルギを発生する手段（例えば電気熱変換体やレーザ光等）を備え、前記熱エネルギによりインクの状態変化を生起させる方式の記録ヘッド、記録装置において優れた効果をもたらすものである。かかる方式によれば記録の高密度化，高精細化が達成できるからである。
【００８２】
その代表的な構成や原理については、例えば、米国特許第４７２３１２９号明細書，同第４７４０７９６号明細書に開示されている基本的な原理を用いて行うものが好ましい。この方式は所謂オンデマンド型，コンティニュアス型のいずれにも適用可能であるが、特に、オンデマンド型の場合には、液体（インク）が保持されているシートや液路に対応して配置されている電気熱変換体に、記録情報に対応していて核沸騰を越える急速な温度上昇を与える少なくとも１つの駆動信号を印加することによって、電気熱変換体に熱エネルギを発生せしめ、記録ヘッドの熱作用面に膜沸騰を生じさせて、結果的にこの駆動信号に一対一で対応した液体（インク）内の気泡を形成できるので有効である。この気泡の成長，収縮により吐出用開口を介して液体（インク）を吐出させて、少なくとも１つの滴を形成する。この駆動信号をパルス形状とすると、即時適切に気泡の成長収縮が行われるので、特に応答性に優れた液体（インク）の吐出が達成でき、より好ましい。このパルス形状の駆動信号としては、米国特許第４４６３３５９号明細書，同第４３４５２６２号明細書に記載されているようなものが適している。なお、上記熱作用面の温度上昇率に関する発明の米国特許第４３１３１２４号明細書に記載されている条件を採用すると、さらに優れた記録を行うことができる。
【００８３】
記録ヘッドの構成としては、上述の各明細書に開示されているような吐出口，液路，電気熱変換体の組合せ構成（直線状液流路または直角液流路）の他に熱作用部が屈曲する領域に配置されている構成を開示する米国特許第４５５８３３３号明細書，米国特許第４４５９６００号明細書を用いた構成も本発明に含まれるものである。加えて、複数の電気熱変換体に対して、共通するスリットを電気熱変換体の吐出部とする構成を開示する特開昭５９−１２３６７０号公報や熱エネルギの圧力波を吸収する開孔を吐出部に対応させる構成を開示する特開昭５９−１３８４６１号公報に基いた構成としても本発明の効果は有効である。すなわち、記録ヘッドの形態がどのようなものであっても、本発明によれば記録を確実に効率よく行うことができるようになるからである。
【００８４】
さらに、記録装置が記録できる記録媒体の最大幅に対応した長さを有するフルラインタイプの記録ヘッドに対しても本発明は有効に適用できる。そのような記録ヘッドとしては、複数記録ヘッドの組合せによってその長さを満たす構成や、一体的に形成された１個の記録ヘッドとしての構成のいずれでもよい。
【００８５】
加えて、上例のようなシリアルタイプのものでも、装置本体に固定された記録ヘッド、あるいは装置本体に装着されることで装置本体との電気的な接続や装置本体からのインクの供給が可能になる交換自在のチップタイプの記録ヘッド、あるいは記録ヘッド自体に一体的にインクタンクが設けられたカートリッジタイプの記録ヘッドを用いた場合にも本発明は有効である。
【００８６】
また、本発明の記録装置の構成として、記録ヘッドの吐出回復手段、予備的な補助手段等を付加することは本発明の効果を一層安定できるので、好ましいものである。これらを具体的に挙げれば、記録ヘッドに対してのキャッピング手段、クリーニング手段、加圧或は吸引手段、電気熱変換体或はこれとは別の加熱素子或はこれらの組み合わせを用いて加熱を行う予備加熱手段、記録とは別の吐出を行なう予備吐出手段を挙げることができる。
【００８７】
また、搭載される記録ヘッドの種類ないし個数についても、例えば単色のインクに対応して１個のみが設けられたものの他、記録色や濃度を異にする複数のインクに対応して複数個数設けられるものであってもよい。すなわち、例えば記録装置の記録モードとしては黒色等の主流色のみの記録モードだけではなく、記録ヘッドを一体的に構成するか複数個の組み合わせによるかいずれでもよいが、異なる色の複色カラー、または混色によるフルカラーの各記録モードの少なくとも一つを備えた装置にも本発明は極めて有効である。
【００８８】
さらに加えて、以上説明した本発明実施例においては、インクを液体として説明しているが、室温やそれ以下で固化するインクであって、室温で軟化もしくは液化するものを用いてもよく、あるいはインクジェット方式ではインク自体を３０℃以上７０℃以下の範囲内で温度調整を行ってインクの粘性を安定吐出範囲にあるように温度制御するものが一般的であるから、使用記録信号付与時にインクが液状をなすものを用いてもよい。加えて、熱エネルギによる昇温を、インクの固形状態から液体状態への状態変化のエネルギとして使用せしめることで積極的に防止するため、またはインクの蒸発を防止するため、放置状態で固化し加熱によって液化するインクを用いてもよい。いずれにしても熱エネルギの記録信号に応じた付与によってインクが液化し、液状インクが吐出されるものや、記録媒体に到達する時点ではすでに固化し始めるもの等のような、熱エネルギの付与によって初めて液化する性質のインクを使用する場合も本発明は適用可能である。このような場合のインクは、特開昭５４−５６８４７号公報あるいは特開昭６０−７１２６０号公報に記載されるような、多孔質シート凹部または貫通孔に液状又は固形物として保持された状態で、電気熱変換体に対して対向するような形態としてもよい。本発明においては、上述した各インクに対して最も有効なものは、上述した膜沸騰方式を実行するものである。
【００８９】
さらに加えて、本発明インクジェット記録装置の形態としては、コンピュータ等の情報処理機器の画像出力端末として用いられるものの他、リーダ等と組合せた複写装置、さらには送受信機能を有するファクシミリ装置の形態を採るもの等であってもよい。
【００９０】
【発明の効果】
以上説明したように、本発明は、溶解可能な樹脂によって形成された基体上のインク流路パターンの上に、インク流路壁となる被覆樹脂層を形成するソルベントコート後に、その被覆樹脂層を減圧状態に保持することによって、その被覆樹脂層を形成する被覆樹脂の溶媒の除去を促進し、インク流路パターンと被覆樹脂層との間に、記録ヘッドの最終製造工程においてゴミとなる相溶層が発生することを回避して、インクジェット記録ヘッドの製造上の歩留まりを向上させることができる。
【００９１】
さらに、被覆樹脂層を形成する被覆樹脂の溶媒として、２−エトキシエタノールを含む溶媒を用いることにより、被覆樹脂層の表面の平坦度を向上させて、インク吐出量のバラツキをきわめて小さい範囲に抑えることができる。
【図面の簡単な説明】
【図１】本発明の記録ヘッドを構成する基板の斜視図である。
【図２】（ａ）は、本発明の記録ヘッドのインク流路パターン形成段階における図１のＡ―Ａ′線に沿う断面図、（ｂ）は、そのインク流路パターンの形成段階における図１のＢ−Ｂ′線に沿う断面図である。
【図３】（ａ）は、本発明の記録ヘッドの被覆樹脂層形成段階における図１のＡ―Ａ′線に沿う断面図、（ｂ）は、その被覆樹脂層形成段階における図１のＢ−Ｂ′線に沿う断面図である。
【図４】（ａ）は、本発明の記録ヘッドの吐出口形成段階における図１のＡ―Ａ′線に沿う断面図、（ｂ）は、その吐出口形成段階における図１のＢ−Ｂ′線に沿う断面図である。
【図５】（ａ）は、本発明の記録ヘッドのインク供給口形成段階における図１のＡ―Ａ′線に沿う断面図、（ｂ）は、そのインク供給口形成段階における図１のＢ−Ｂ′線に沿う断面図である。
【図６】（ａ）は、本発明の記録ヘッドの被覆樹脂層溶解段階における図１のＡ―Ａ′線に沿う断面図、（ｂ）は、その被覆樹脂層溶解段階における図１のＢ−Ｂ′線に沿う断面図である。
【図７】本発明の記録ヘッドの第２の実施形態における実施例１の要部の拡大断面図である。
【図８】本発明の記録ヘッドの第２の実施形態における実施例２の要部の拡大断面図である。
【図９】本発明の記録ヘッド全体の構成例を説明するための斜視図である。
【図１０】本発明の記録ヘッドを使用可能な記録装置の要部の斜視図である。
【符号の説明】
１ 基板（基体）
２ 電気熱変換素子
３ インク流路パターン
４ 被覆樹脂層
５ 吐出口
６ インク供給口[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an ink jet recording head capable of discharging minute ink droplets, an ink jet recording head manufactured by the method, and an ink jet recording apparatus using the ink jet recording head manufactured by the method.
[0002]
[Prior art]
Conventionally, various methods have been proposed for manufacturing an ink jet recording head used in ink jet recording technology. The present applicant has previously proposed a method for manufacturing an inkjet recording head that is optimal for obtaining a high-quality image in Patent Document 1. This Patent Document 1 describes a method of manufacturing an ink jet recording head that is optimal for the following ink ejection method. That is, the ink discharge method is applied to the electrothermal conversion element as the ink discharge pressure generating element (discharge energy generating element) described in Patent Document 2, Patent Document 3, and Patent Document 4, in accordance with the recording information. Is applied to the electrothermal conversion element to generate thermal energy that gives the ink a rapid temperature rise exceeding nucleate boiling, thereby forming bubbles in the ink, and communicating the bubbles with the outside air to form ink droplets. It is a method of discharging. Specifically, Patent Document 1 discloses a method of forming a coating resin layer containing an epoxy resin on a dissolvable ink flow path pattern.
[0003]
In the ink discharge methods described in Patent Document 2, Patent Document 3, and Patent Document 4, the distance between the electrothermal conversion element and the orifice (formation surface of the ink discharge port) (hereinafter referred to as “OH” distance). ) Is the main factor that determines the ink ejection volume, it is important to set the OH distance accurately and with good reproducibility with respect to the design value. As a specific example, Patent Document 1 previously proposed by the present applicant applies a coating resin when forming a coating resin layer containing an epoxy resin on an ink flow path pattern formed of a soluble resin. A method is disclosed in which a solvent is dissolved and dissolved in a solvent at a concentration of 30 to 70 wt%.
[0004]
[Patent Document 1]
JP-A-6-286149
[0005]
[Patent Document 2]
Japanese Patent Laid-Open No. 4-10940
[0006]
[Patent Document 3]
JP-A-4-10941
[0007]
[Patent Document 4]
JP-A-4-10942
[0008]
[Problems to be solved by the invention]
According to a detailed study by the present inventors, when forming a coating resin layer containing an epoxy resin on an ink flow path pattern formed of a dissolvable resin, an ink flow path pattern and a coating resin layer are rarely used. It was confirmed that a very thin compatible layer was generated between the two and that became garbage in the final process, resulting in the occurrence of defective products.
[0009]
In addition, when laminating resists, as a method for preventing compatibility between resists, for example, JP-A-5-17285 discloses that an upper layer resist is formed by vapor deposition polymerization. However, in an inkjet recording head, the coating resin layer needs to have a film thickness of about 5 μm or more, and it is required to form a flat film with good coverage on the ink flow path pattern. Have difficulty.
[0010]
On the other hand, in recent years, there has been a demand for high image quality comparable to silver salt photography in ink jet recording, and for that purpose, it is necessary to eject ink droplets of about 10 picoliters or less with high reproducibility. There is a need to further increase the accuracy of the nozzle structure including the setting accuracy of the OH distance.
[0011]
An object of the present invention is to improve an ink jet recording head manufacturing yield, further improve the flatness of the surface of the coating resin layer, and suppress an ink discharge amount variation within a very small range. It is an object to provide a manufacturing method, an ink jet recording head, and an ink jet recording apparatus.
[0012]
[Means for Solving the Problems]
The inkjet recording head manufacturing method of the present invention includes a substrate provided with an ejection energy generating element that generates energy used for ejecting ink. Dissolution Forming an ink flow path pattern with possible resin; At normal temperature The coating resin containing a solid epoxy resin is dissolved in a solvent, and the ink flow path pattern is dissolved in the solvent. of The ink flow path pattern is formed by solvent coating on the top. of Forming a coating resin layer on the ink flow path wall; Above Coating resin layer In Forming an ink ejection port; Remove the ink flow path pattern And a step of holding the coating resin layer under reduced pressure after solvent coating for forming the coating resin layer.
[0013]
The ink jet recording head of the present invention is manufactured by the above method.
[0014]
The inkjet recording apparatus of the present invention is an inkjet recording apparatus capable of recording an image on a recording medium using an inkjet recording head, wherein the inkjet recording head manufactured by the above method is used as the inkjet recording head. And
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
(First embodiment)
FIG. 1 is a perspective view of a silicon substrate 1 on which a plurality of electrothermal conversion elements 2 as ink discharge pressure generating elements (discharge energy generating elements) are arranged. The electrothermal conversion element 2 is connected to an electrode and an IC circuit (not shown) in order to operate the element 2.
[0017]
2 to 6 are explanatory diagrams of the manufacturing procedure of the ink jet recording head using the silicon substrate 1 of FIG. In these drawings, (a) is a sectional view taken along the line AA in FIG. 1, and (b) is a sectional view taken along the line BB in FIG.
[0018]
First, as shown in FIGS. 2A and 2B, the ink flow path pattern 3 is formed on the substrate 1 by a soluble resin layer. As a material for forming the ink flow path pattern, a positive resist can be suitably used. The positive resist is required to have a characteristic that it does not dissolve when a coating resin layer described later is solvent-coated, and therefore a resist composed of an ionizing radiation decomposing polymer compound having a molecular weight of 10,000 or more is optimal. Specific examples include polymethyl methacrylate and polymethyl isopropenyl ketone.
[0019]
Next, the coating resin containing the epoxy resin is dissolved in a solvent, and applied onto the dissolvable ink flow path pattern 3 by a solvent coating method such as spin coating, and the coating resin shown in FIGS. 3 (a) and 3 (b). Such a coating resin layer 4 is formed.
[0020]
Usually, in a solvent coating method such as spin coating, a film is formed by drying a coating solvent by a heat treatment after coating (about 70 ° C. to about 120 ° C.). That is, heat treatment for drying the solvent is performed in a state in which the coating solvent at the time when the coating is finished remains. Therefore, an extremely thin compatible layer may be formed between the ink flow path pattern and the coating resin layer 4. According to the study by the present inventor, it has been found that this compatible layer remains as dust in the post-processing step, and as a result, decreases the manufacturing yield of the ink jet recording head.
[0021]
When forming the coating resin layer 4 on the dissolvable ink flow path pattern 3, the present inventor holds the substrate 1 in a reduced pressure state after application of the dissolved coating resin and before the heat treatment. It has been found that the generation of the compatible layer can be completely suppressed by removing most of the coating solvent and then performing heat treatment to form a film. Therefore, when the coating resin layer 4 in FIGS. 3A and 3B is formed, the coating solvent is removed by such reduced pressure. The reduced pressure state can be appropriately set depending on the vapor pressure of the coating solvent used. The reduced pressure state needs to be set to approximately 50 cmHg or less, and is preferably set to 30 cmHg or less. Moreover, it is preferable to set the temperature of the board | substrate 1 in such a pressure-reduced state to 50 degrees C or less. That is, from the viewpoint of drying the solvent, it is preferable that the temperature is high even in a reduced pressure state, but from the viewpoint of preventing the formation of a compatible layer, a temperature of 50 ° C. or less is optimal.
[0022]
The coating solvent is required to have a property of completely dissolving the epoxy resin and the like and not dissolving the ink flow path pattern 3, and at the same time is appropriately selected depending on the film thickness of the coating resin layer 4 to be formed. Specific examples include methyl isobutyl ketone, 2 ethoxyethanol, ethyl cellosolve acetate, diglyme, toluene, xylene and the like.
[0023]
After the coating resin layer 4 is formed, the discharge port 5 is formed in the coating resin layer 4 as shown in FIGS. As a method for forming the discharge port 5, for example, a method in which the coating resin layer 4 is made photosensitive, exposed (photocured) by a normal photolithography technique and developed, or the coating resin layer 4 is formed. It is possible to adopt a method in which the film is heated and cured and etched by an excimer laser or oxygen plasma.
[0024]
Next, as shown in FIGS. 5A and 5B, the substrate 1 is subjected to anisotropic etching from the back surface to form the ink supply port 6. The ink supply port 6 may be previously formed in the substrate 1 by mechanical processing.
[0025]
Finally, as shown in FIGS. 6A and 6B, the ink flow path pattern 3 is dissolved to complete the nozzle. Then, the ink jet recording head is completed by electrical connection (not shown) and connection with the ink supply member.
[0026]
Hereinafter, specific examples in the first embodiment of the present invention will be described.
[0027]
(Example 1 of the first embodiment)
In this example, an ink jet recording head was manufactured according to the procedure shown in FIGS. 1 to 6 described above. First, two rows of 30 μm-square electrothermal transducers (tantalum nitride TaN) 2 were arranged on the silicon substrate 1 in the form shown in FIG. The electrothermal conversion elements 2 are arranged for 256 nozzles and arranged in two rows and staggered at a pitch of 300 DPI so that 256 nozzles of 600 DPI can be formed as a recording head. The substrate 1 is arranged for 200 chips on a silicon substrate material.
[0028]
Next, a positive resist ODUR1010 (polymethyl isopropenyl ketone manufactured by Tokyo Ohka Kogyo Co., Ltd.) is spin-coated to form the ink flow path pattern 3 with a soluble resin as shown in FIGS. 2 (a) and 2 (b). Was applied to form a film. Thereafter, pattern exposure (exposure time: 3 minutes) was performed through a mask using a Canon mask aligner PLA620 (compatible with deep UV), and then development processing was performed to form an ink flow path pattern 3.
[0029]
Next, in order to form the coating resin layer 4 as shown in FIGS. 3A and 3B, the coating resin composition shown in Table 1 below is dissolved in 2-ethoxyethanol as a coating solvent at a concentration of 50 wt%. Then, it was applied onto the ink flow path pattern 3 by spin coating. The application is performed while adjusting the spin speed so that the coating resin layer 4 becomes 12 μm. After completion of the spin coating, the coating solvent was dried at a temperature of 40 ° C. for 3 minutes under a reduced pressure of 5 cmHg, and finally baked at a temperature of 90 ° C. for 3 minutes under normal pressure.
[0030]
[Table 1]

[0031]
Next, the discharge port 5 is formed as shown in FIGS. In the case of this example, the coating resin layer 4 contains a cationic photopolymerization initiator and has a negative photosensitive property. Therefore, the discharge port 5 is formed by photolithography. That is, using Canon mask aligner MPA600, pattern exposure (exposure time 50 seconds) is performed through a mask, followed by heat treatment at a temperature of 90 ° C. for 4 minutes, and then development treatment is performed to form the discharge port 5. did. The diameter of the discharge port 5 was formed to φ20 μm.
[0032]
Next, anisotropic etching of silicon was performed from the back surface of the silicon substrate 1 through a mask to form an ink supply port 6 as shown in FIGS.
[0033]
Next, after the ink flow path pattern 3 remaining in the current process was decomposed by the entire surface exposure, it was removed with methyl lactate as shown in FIGS. 6 (a) and 6 (b).
[0034]
Thereafter, in order to completely cure the coating resin layer 4, a heat treatment was performed at a temperature of 200 ° C. for 1 hour, and then an electrical connection and an ink supply member were arranged to complete the ink jet recording head.
[0035]
As a comparison target of the recording head of this embodiment manufactured in this way, after the coating of the coating resin layer 4 is completed, it is baked for 3 minutes at a temperature of 90 ° C. under normal pressure without being held under reduced pressure. Thus, a sample in which the coating solvent was dried was prepared. The processing for the sample is the same as the processing for the recording head of the above-described embodiment, except that there is no holding under reduced pressure after the spin coating of the coating resin layer 4 is completed.
[0036]
In the case of the recording head of this example, that is, the recording head held under reduced pressure after the spin coating of the coating resin layer 4 was completed, the yield was 95% as a result of the recording inspection for recording an image of a predetermined pattern. When 5% of the defects were analyzed, dust or the like was not detected by microscopic observation, and the cause could not be specified.
[0037]
On the other hand, in the case of a sample as a comparison target, that is, a recording head that was not held under reduced pressure after the spin coating of the coating resin layer 4 was completed, the yield was 81% as a result of the recording inspection similar to the recording head of this example. It was. When 19% of the defects were analyzed, in the microscopic observation, 13% of the defects due to thin-film dust were found, and 6% were those whose cause could not be identified without being detected. The thin-film dust is considered to be a compatible material of the ink flow path pattern 3 and the coating resin layer 4.
[0038]
(Example 2 of the first embodiment)
In this example, two rows of 24 μm square electrothermal transducers 2 were arranged. The electrothermal conversion elements 2 are arranged for 300 nozzles and arranged in two rows and staggered at a pitch of 600 DPI so that 300 nozzles of 1200 DPI can be formed as a recording head. The substrate 1 is arranged for 250 chips on a silicon substrate material.
[0039]
Using such a substrate 1, a recording head was produced by the same method as in Example 1 described above. However, xylene was used as a coating solvent, and the coating resin composition shown in Table 1 was dissolved at a concentration of 45 wt% and applied onto the ink flow path pattern 3 by spin coating. The application is performed while adjusting the spin speed so that the coating resin layer 4 becomes 12 μm. After completion of the spin coating, the coating solvent was dried at a temperature of 40 ° C. for 3 minutes under a reduced pressure of 10 cmHg and finally baked at a temperature of 90 ° C. for 3 minutes under normal pressure. The diameter of the discharge port 5 was φ15 μm.
[0040]
As a comparison target of the recording head of this example manufactured in this way, after the end of spin coating of the coating resin layer 4, it was baked for 3 minutes at a temperature of 90 ° C. under normal pressure without being held under reduced pressure. A sample was prepared by drying the coating solvent.
[0041]
In the case of the recording head of this example, that is, the recording head held under reduced pressure after the spin coating of the coating resin layer 4 was completed, the yield was 93% as a result of the recording inspection for recording an image of a predetermined pattern. When 7% of the defects were analyzed, in microscopic observation, thread-like dust or the like was detected in 2% of the recording heads, and no dust or the like was detected for the remaining recording heads, and the cause could not be specified. The yarn-like dust is dust that seems to have been mixed during the assembly process, and the form was clearly different from the thin-film dust detected in the sample as a comparative example of Example 1 described above.
[0042]
On the other hand, in the case of a sample to be compared, that is, a recording head that was not held under reduced pressure after the spin coating of the coating resin layer 4 was completed, the yield was 85% as a result of the recording inspection similar to the recording head of this example. It was. When 15% of the defects were analyzed, in the microscopic observation, the defect due to the thin film-like dust was 10%, and the dust was not detected and the cause could not be identified was 5%. The thin-film dust is considered to be a compatible material of the ink flow path pattern 3 and the coating resin layer 4.
[0043]
(Example 3 of the first embodiment)
In this example, a recording head was prepared in the same manner as in Example 1 described above. However, methyl isobutyl ketone / diglyme = 1/1 (wt) is used as a coating solvent, the coating resin composition shown in Table 2 below is dissolved at a concentration of 50 wt%, and spin coating is performed on the ink flow path pattern 3. Applied. The application is performed while adjusting the spin speed so that the coating resin layer 4 becomes 12 μm. After completion of the spin coating, the coating solvent was dried at a temperature of 40 ° C. for 3 minutes under a reduced pressure of 5 cmHg, and finally baked at a temperature of 90 ° C. for 3 minutes under normal pressure. The diameter of the discharge port 5 was φ20 μm. In forming the ejection port 5, the exposure time was 60 seconds.
[0044]
[Table 2]

[0045]
As a comparison target of the recording head of this example manufactured in this way, after the end of spin coating of the coating resin layer 4, it was baked for 3 minutes at a temperature of 90 ° C. under normal pressure without being held under reduced pressure. A sample was prepared by drying the coating solvent.
[0046]
In the case of the recording head of this example, that is, the recording head held under reduced pressure after the spin coating of the coating resin layer 4 was completed, the yield was 82% as a result of recording inspection recording an image of a predetermined pattern. When 18% of the defects were analyzed, thin film dust or the like was not detected by microscopic observation.
[0047]
On the other hand, in the case of a sample to be compared, that is, a recording head that was not held under reduced pressure after the spin coating of the coating resin layer 4 was completed, the yield was 75% as a result of the recording inspection similar to the recording head of this example. It was. When 25% of the defects were analyzed, 18% of the defects due to thin-film dust were detected by microscopic observation. The thin-film dust is considered to be a compatible material of the ink flow path pattern 3 and the coating resin layer 4.
[0048]
As is clear from Examples 1, 2, and 3 above, regardless of the type of coating solvent, the recording head held under reduced pressure after the end of spin coating of the coating resin layer 4 and the end of spin coating of the coating resin layer 4 are completed. As a result of the recording inspection of the recording head that was not held under reduced pressure, a large difference occurred in the appearance rate of thin film-like dust considered to be a compatible material of the ink flow path pattern 3 and the coating resin layer 4, and the difference in yield was found. occured.
[0049]
(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described.
[0050]
In the present embodiment, the recording head is manufactured by the same procedure as that shown in FIGS. 1 to 6 as in the first embodiment. In the present embodiment, the manufacturing stage shown in FIGS. 3A and 3B, that is, a coating resin containing an epoxy resin is dissolved in a solvent, and is applied onto the ink flow path pattern 3 by a solvent coating method such as spin coating. In the production stage in which the coating resin layer 4 is formed by coating, the coating solvent was selected from the viewpoint of film thickness accuracy of the coating resin layer 4.
[0051]
That is, first, since the ink flow path pattern 3 has a film thickness of 10 μm or more in many cases, the coating resin layer 4 must be formed so as to absorb at least 10 μm or more unevenness and to have a flat surface. I must. 3A and 3B, the distance L corresponding to the sum of the film thickness of the ink flow path pattern 3 on the electrothermal conversion element 2 and the film thickness of the coating resin layer 4 is the OH distance described above, that is, the electricity. This is the distance between the thermal conversion element 2 and the orifice (formation surface of the ink discharge port), and as described above, it is important to set the OH distance accurately in order to suppress the variation in the characteristics of each nozzle. . Regarding the thickness control of the former ink flow path pattern 3, since the ink flow path pattern 3 is basically formed on the substantially flat substrate 1, sufficient film thickness accuracy can be obtained by a normal spin coating method or the like. it can. The problem is the film thickness management of the latter coating resin layer 4.
[0052]
In JP-A-6-286149 described above, when the coating resin layer 4 containing an epoxy resin is formed on the ink flow path pattern 3 formed of a soluble resin, the concentration of the coating resin is 30 to 70 wt%. Describes a method in which it is dissolved in a coating solvent and formed by solvent coating. As a result of detailed studies by the present inventor, in order to manage the film thickness of the coating resin layer 4 with higher accuracy, it has been found that it is necessary to select a coating solvent together with the solid content concentration of the coating resin. In selecting the coating solvent, the thick film accuracy such as not dissolving and deforming the dissolvable flow path pattern 3 and dissolving the coating resin including the epoxy resin to the required solid content concentration are the considerations. There are other items to consider. According to the study of the present inventor, it was found that 2-ethoxyethanol (trade name: Ethyl Cellosolve) is optimal as the coating solvent.
[0053]
Specific examples in the second embodiment of the present invention will be described below.
[0054]
(Example 1 of the second embodiment)
In this example, an ink jet recording head was manufactured according to the procedure shown in FIGS. 1 to 6 described above. First, two rows of 30 μm-square electrothermal transducers (tantalum nitride TaN) 2 were arranged on the silicon substrate 1 in the form shown in FIG. The electrothermal conversion elements 2 are arranged for 256 nozzles and arranged in two rows and staggered at a pitch of 300 DPI so that 256 nozzles of 600 DPI can be formed as a recording head. The substrate 1 is arranged for 200 chips on a silicon substrate material.
[0055]
Next, in order to form a dissolvable ink flow path pattern 3 as shown in FIGS. 2A and 2B, a positive resist ODUR1010 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied using a spin coat, Filmed. Thereafter, pattern exposure (exposure time: 3 minutes) was performed through a mask using a Canon mask aligner PLA620 (compatible with deep UV), and then development processing was performed to form an ink flow path pattern 3. The design shape of the ink flow path pattern 3 is as shown in FIG. 7 (corresponding to a cross-sectional view along the line BB ′ in FIG. 1), the width is 33 μm, and the film thickness is 13 μm. The width of the electrothermal conversion element 2 is 30 μm, and the interval between the adjacent electrothermal conversion elements 2 is 84.5 μm.
[0056]
The thickness of the ink flow path pattern 3 of 10 nozzles in one substrate (1 chip) 1 is equivalent to the thickness of 10 substrates (10 chips), that is, the thickness of the ink flow path pattern 3 for a total of 100 nozzles. As a result of measurement by a total (λ ace), the average film thickness was 13.1 μm (the variation was σ = 0.1 μm), and it was confirmed that the film was formed in a substantially uniform film thickness.
[0057]
Next, in order to form the coating resin layer 4 as shown in FIGS. 3A and 3B, the coating resin composition shown in Table 3 below was dissolved in 2-ethoxyethanol as a coating solvent at a concentration of 50 wt%. Then, it was applied onto the ink flow path pattern 3 by spin coating. The application is performed while adjusting the spin speed so that the coating resin layer 4 becomes 12 μm. Then, the coating solvent was dried by baking at a temperature of 90 ° C. for 3 minutes.
[0058]
[Table 3]

[0059]
Next, the discharge port 5 is formed as shown in FIGS. In the case of this example, the coating resin layer 4 contains a cationic photopolymerization initiator and has a negative photosensitive property. Therefore, the discharge port 5 is formed by photolithography. That is, using Canon mask aligner PLA620, pattern exposure (exposure time: 4 seconds) is performed through a mask, followed by heat treatment at a temperature of 90 ° C. for 3 minutes, and then development treatment is performed to form the discharge port 5 did. The diameter of the discharge port 5 was formed to φ20 μm.
[0060]
Next, anisotropic etching of silicon was performed from the back surface of the silicon substrate 1 through a mask to form an ink supply port 6 as shown in FIGS. Next, after the ink flow path pattern remaining in the current process was decomposed by full exposure, it was removed by methyl lactate as shown in FIGS. 6 (a) and 6 (b). Thereafter, in order to completely cure the coating resin layer 4, a heat treatment was performed at a temperature of 200 ° C. for 1 hour.
[0061]
After forming the nozzle structure in this way, the OH distance between the electrothermal transducer 2 and the discharge port 5 formation surface was measured using an interference film thickness meter (Zygo new view 200). The measurement points of the OH distance were 10 nozzles in one substrate (1 chip) 1 for 10 substrates (10 chips), that is, 100 nozzles in total. The average of the OH distances for 100 nozzles was 25.0 μm (the variation was σ = 0.04 μm).
[0062]
As a comparison object of the nozzle structure of this example, methyl isobutyl ketone described in Example 1 of the above-mentioned JP-A-6-286149 is used instead of 2-ethoxyethanol as a coating solvent for the coating resin. The coating resin layer 4 was formed using / xylene = 1/1 (parts by weight). As a result of measuring the OH distance of the comparative sample by the measurement method described above, the average was 24.9 μm (the variation was σ = 0.9 μm). Although the average value of the OH distance in the above-described embodiment of the present invention and the average value of the OH distance in the sample to be compared are both formed to be approximately 25 μm of the designed value, the variation of the OH distance σ It was confirmed that the value was reduced to half or less in the case of the former embodiment of the present invention as compared with the latter sample to be compared.
[0063]
Further, a print head is configured by arranging an electrical connection and an ink tank supply member for each of the nozzle structure in the former embodiment of the present invention and the nozzle structure in the latter comparative sample. Ink droplets were ejected from both recording heads. As a result of measuring the ejection amount of ink droplets from one nozzle per recording head for each of the recording heads for each of the recording heads, the ink droplets in the recording head of the former embodiment of the present invention were measured. The average value of the discharge amount was 8.5 picoliters, and the variation was ± 0.3 picoliters. On the other hand, the average value of the ink droplet ejection amount in the latter sample to be compared was 8.5 picoliters, and the variation was ± 0.6 picoliters. As is clear from the comparison between the two, the recording head using 2-ethoxyethanol (ethyl cellosolve) as the coating solvent as in the embodiment of the present invention reflects the reduction in variation in OH accuracy, and ink drops The variation in the discharge amount can be kept small.
[0064]
(Example 2 of the second embodiment)
In this example, an ink jet recording head was manufactured according to the procedure shown in FIGS. 1 to 6 described above. First, two rows of 24 μm square electrothermal transducers (tantalum nitride TaN) 2 were arranged on the silicon substrate 1 in the form shown in FIG. The electrothermal conversion elements 2 are arranged for 300 nozzles, and are arranged in two rows and staggered at a pitch of 600 DPI so that 300 nozzles of 1200 DPI can be formed as a recording head. The substrate 1 is arranged for 250 chips on a silicon substrate material.
[0065]
Next, in the same manner as in Example 1 described above, the ink flow path pattern 3 was formed from a soluble resin as shown in FIGS. 2 (a) and 2 (b). The design shape of the ink flow path pattern 3 is as shown in FIG. 8 (corresponding to a cross-sectional view along the line BB ′ in FIG. 1), the width is 30 μm, and the film thickness is 13 μm. The width of the electrothermal conversion element 2 is 24 μm, and the interval between the adjacent electrothermal conversion elements 2 is 42.5 μm.
[0066]
The thickness of the ink flow path pattern 3 of 10 nozzles in one substrate (1 chip) 1 is equivalent to the thickness of 10 substrates (10 chips), that is, the thickness of the ink flow path pattern 3 for a total of 100 nozzles. As a result of measurement with a total (λ ace), the average film thickness was 13.0 μm (the variation was σ = 0.1 μm), and it was confirmed that the film was formed in a substantially uniform film thickness.
[0067]
Next, in order to form the coating resin layer 4 as shown in FIGS. 3A and 3B, the coating resin composition shown in Table 4 below was dissolved in 2-ethoxyethanol as a coating solvent at a concentration of 50 wt%. Then, it was applied onto the ink flow path pattern 3 by spin coating. The application is performed while adjusting the spin speed so that the coating resin layer 4 becomes 12 μm. Then, the coating solvent was dried by baking at a temperature of 90 ° C. for 3 minutes.
[0068]
[Table 4]

[0069]
Next, the discharge port 5 is formed as shown in FIGS. In the case of this example, the coating resin layer 4 contains a cationic photopolymerization initiator and has a negative photosensitive property. Therefore, the discharge port 5 is formed by photolithography. That is, using Canon mask aligner MPA600, pattern exposure (exposure time 60 seconds) is performed through a mask, and then heat treatment is performed at a temperature of 90 ° C. for 3 minutes, followed by developing treatment to form the discharge port 5. did. The diameter of the discharge port 5 was formed to φ15 μm.
[0070]
Next, anisotropic etching of silicon was performed from the back surface of the silicon substrate 1 through a mask to form an ink supply port 6 as shown in FIGS. Next, after the ink flow path pattern remaining in the current process was decomposed by full exposure, it was removed by methyl lactate as shown in FIGS. 6 (a) and 6 (b). Thereafter, in order to completely cure the coating resin layer 4, a heat treatment was performed at a temperature of 200 ° C. for 1 hour.
[0071]
After forming the nozzle structure in this way, the OH distance between the electrothermal transducer 2 and the discharge port 5 formation surface was measured using an interference film thickness meter (Zygo new view 200). The measurement points of the OH distance were 10 nozzles in one substrate (1 chip) 1 for 10 substrates (10 chips), that is, 100 nozzles in total. The average of the OH distances for 100 nozzles was 25.0 μm (the variation was σ = 0.3 μm).
[0072]
Further, an electrical connection and an ink tank supply member are arranged for such a nozzle structure to constitute a recording head, and ink droplets are ejected from the recording head. As a result of measuring the ejection amount of ink droplets from one nozzle per recording head for 10 recording heads, the average ejection amount of ink droplets is 5.0 picoliters, and the variation is ± 0.2 picoliters. Met. Thus, although the ink discharge amount per nozzle is a minute amount of 5 picoliters, the variation can be suppressed to an extremely small range.
[0073]
In the above-described Examples 1 and 2, as in the first embodiment of the present invention described above, by holding under reduced pressure after the coating resin layer 4 has been applied, the appearance rate of thin-film dust is suppressed, It is also possible to improve the manufacturing yield of the recording head. Due to the synergistic effect of these combinations, the reliability of the recording head can be greatly improved.
[0074]
(Configuration example of the entire inkjet recording head)
FIG. 9 is a perspective view for explaining an overall configuration example of the ink jet recording head of the present invention.
[0075]
In FIG. 9, 2 is an element substrate having the nozzle structure in the first and second embodiments described above, and a plurality of ejection ports 4 arranged in two rows are provided in a staggered manner. The element substrate 2 is bonded and fixed to a part of the support member 102 processed into an L shape. The wiring portion of the wiring substrate 104 fixed on the support member 102 and the wiring portion of the element substrate 2 are electrically connected by bonding. The support member 102 is formed of an aluminum material from the viewpoints of cost, workability, and the like. The mold member 103 inserts a part of the support member 102 therein to support the support member 102, and supplies the ink supply described above from the ink reservoir through an ink supply path formed inside the mold member 103. A member for supplying ink to the mouth 6. The mold member 103 also serves as a mounting and positioning member for removably fixing the entire recording head of this example to the ink jet recording apparatus.
[0076]
(Configuration example of ink jet recording apparatus)
FIG. 10 is a schematic perspective view of a serial type ink jet recording apparatus that can use the ink jet recording head of the present invention.
[0077]
In FIG. 10, reference numeral 200 denotes a carriage on which the above-described ink jet recording head of the present invention is detachably mounted. In the case of this example, four types of recording heads are mounted according to the type of ink color, and are mounted on the carriage 200 together with a yellow ink tank 201Y, a magenta ink tank 201M, a cyan ink tank 201C, and a black ink tank 201B. Installed.
[0078]
The carriage 200 is supported by the guide shaft 202 and reciprocated in the direction of arrow A (main scanning direction) along the guide shaft 202 by an endless belt 204 driven in the forward direction or the reverse direction by the motor 203. The endless belt 204 is bridged between the pulleys 205 and 206.
[0079]
The recording paper P as a recording medium is intermittently conveyed in an arrow B direction (sub-scanning direction) orthogonal to the arrow A direction. The recording paper P is sandwiched between a pair of upstream roller units 207 and 208 and a pair of downstream roller units 209 and 210, and is applied with a constant tension to ensure flatness with respect to the recording head. Be transported. Driving force for each roller unit is applied from the driving unit 211. Each roller unit may be driven by a motor 203.
[0080]
The carriage 200 stops at the home position as necessary during recording start or recording operation. This position is provided with a cap member 212 that caps the ejection port surface of each recording head. The cap member 212 is connected to suction recovery means for forcibly sucking ink that does not contribute to image recording from the discharge port that opens on the discharge port surface to prevent clogging in the discharge port.
[0081]
(Other)
The present invention includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for ejecting ink, particularly in the ink jet recording system, and the ink is generated by the thermal energy. In the recording head and the recording apparatus of the type that causes the state change, excellent effects are brought about. This is because such a system can achieve high recording density and high definition.
[0082]
As for the typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid and, as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0083]
As the configuration of the recording head, in addition to the combination configuration (straight liquid channel or right angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting part The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the lens is disposed in the bending region, are also included in the present invention. In addition, for a plurality of electrothermal transducers, Japanese Patent Application Laid-Open No. Sho 59-123670 that discloses a configuration in which a common slit is used as a discharge portion of the electrothermal transducer or an aperture that absorbs pressure waves of thermal energy is provided. The effect of the present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461 which discloses a configuration corresponding to the discharge unit. That is, whatever the form of the recording head is, according to the present invention, recording can be performed reliably and efficiently.
[0084]
Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. As such a recording head, either a configuration satisfying the length by a combination of a plurality of recording heads or a configuration as a single recording head formed integrally may be used.
[0085]
In addition, even the serial type as shown in the above example can be connected to the main body of the recording head or attached to the main body of the device so that electrical connection with the main body of the device and ink supply from the main body are possible. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.
[0086]
In addition, it is preferable to add a recording head ejection recovery means, a preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention, since the effects of the present invention can be further stabilized. Specifically, heating is performed using a capping unit, a cleaning unit, a pressurizing or suction unit, an electrothermal transducer, a heating element different from this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.
[0087]
Also, regarding the type or number of recording heads to be mounted, for example, a plurality of recording heads are provided corresponding to a plurality of inks having different recording colors and densities, in addition to one provided corresponding to a single color ink. May be used. That is, for example, as a recording mode of the recording apparatus, not only a recording mode of only a mainstream color such as black, but also a recording head may be configured integrally or by a combination of a plurality of different colors, Alternatively, the present invention is extremely effective for an apparatus having at least one of full-color recording modes by color mixing.
[0088]
In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, ink that is solidified at room temperature or lower and that softens or liquefies at room temperature may be used. In the ink jet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that it is in the stable discharge range. A liquid material may be used. In addition, it is solidified and heated in an untreated state in order to actively prevent the temperature rise caused by thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating. You may use the ink which liquefies by. In any case, by applying thermal energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case where ink having a property of being liquefied for the first time is used. The ink in such a case is in a state of being held as a liquid or a solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, the electrothermal converter may be opposed to the electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0089]
In addition, the ink jet recording apparatus according to the present invention may be used as an image output terminal of an information processing device such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. The thing etc. may be sufficient.
[0090]
【The invention's effect】
As described above, according to the present invention, the coating resin layer is formed after the solvent coating for forming the coating resin layer serving as the ink channel wall on the ink channel pattern on the substrate formed of the soluble resin. By maintaining the reduced pressure state, the removal of the solvent of the coating resin that forms the coating resin layer is promoted, and the compatibility between the ink flow path pattern and the coating resin layer becomes dust in the final manufacturing process of the recording head. The generation of layers can be avoided, and the manufacturing yield of the ink jet recording head can be improved.
[0091]
Further, by using a solvent containing 2-ethoxyethanol as a solvent for the coating resin for forming the coating resin layer, the flatness of the surface of the coating resin layer is improved and the variation in the ink discharge amount is suppressed to a very small range. be able to.
[Brief description of the drawings]
FIG. 1 is a perspective view of a substrate constituting a recording head of the present invention.
2A is a cross-sectional view taken along the line AA ′ of FIG. 1 at the ink flow path pattern forming stage of the recording head of the present invention, and FIG. 2B is a view at the ink flow path pattern forming stage. It is sectional drawing which follows the BB 'line of 1. FIG.
3A is a cross-sectional view taken along the line AA ′ of FIG. 1 in the coating resin layer forming stage of the recording head of the present invention, and FIG. 3B is a cross-sectional view of FIG. It is sectional drawing which follows the -B 'line.
4A is a cross-sectional view taken along the line AA ′ of FIG. 1 in the discharge port formation stage of the recording head of the present invention, and FIG. 4B is a cross-sectional view of FIG. It is sectional drawing which follows a 'line.
5A is a cross-sectional view taken along the line AA ′ of FIG. 1 in the ink supply port forming stage of the recording head of the present invention, and FIG. 5B is a cross-sectional view of FIG. 1B in the ink supply port forming stage. It is sectional drawing which follows the -B 'line.
6A is a cross-sectional view taken along the line AA ′ of FIG. 1 in the coating resin layer dissolution stage of the recording head of the present invention, and FIG. 6B is a cross-sectional view of FIG. It is sectional drawing which follows the -B 'line.
FIG. 7 is an enlarged cross-sectional view of a main part of Example 1 in the second embodiment of the recording head of the present invention.
FIG. 8 is an enlarged cross-sectional view of a main part of Example 2 in the second embodiment of the recording head of the present invention.
FIG. 9 is a perspective view for explaining a configuration example of the entire recording head of the present invention.
FIG. 10 is a perspective view of a main part of a recording apparatus that can use the recording head of the present invention.
[Explanation of symbols]
1 Substrate (base)
2 electrothermal transducer
3 Ink flow path pattern
4 Coating resin layer
5 Discharge port
6 Ink supply port

Claims (9)

Forming an ink flow path pattern with a dissolvable resin on a substrate provided with an ejection energy generating element that generates energy used for ejecting ink; and
The coating resin containing a solid epoxy resin dissolved in a solvent at ambient temperature, by solvent coating onto the ink flow path pattern this coating resin serving as an ink flow path wall on said ink flow path pattern Forming a layer;
The coating resin layer, forming ink discharge ports,
Removing the ink flow path pattern,
In the manufacturing method of the inkjet recording head having
A method of manufacturing an ink jet recording head, comprising a step of holding the coating resin layer under reduced pressure after solvent coating for forming the coating resin layer.   The method of manufacturing an ink jet recording head according to claim 1, wherein the reduced pressure is 30 cmHg or less.   The method of manufacturing an ink jet recording head according to claim 1, wherein the reduced pressure is a temperature of 50 ° C. or less. The soluble resin forming the ink flow path pattern is ionizing radiation decomposition type, the manufacture of ink jet recording head according to claim 1, characterized in that it comprises a polymethyl isopropenyl ketone 3 Method.   5. The method of manufacturing an ink jet recording head according to claim 1, wherein the solvent for dissolving the coating resin contains xylene.   6. The method of manufacturing an ink jet recording head according to claim 1, wherein the solvent for dissolving the coating resin contains 2-ethoxyethanol.   7. The method of manufacturing an ink jet recording head according to claim 1, wherein the ejection energy generating element is an electrothermal conversion element that generates thermal energy.   An ink jet recording head manufactured by the method according to claim 1. In an inkjet recording apparatus capable of recording an image on a recording medium using an inkjet recording head,
An ink jet recording apparatus using the ink jet recording head manufactured by the method according to claim 1 as the ink jet recording head.

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