JP3597995B2

JP3597995B2 - Printing apparatus and manufacturing method thereof

Info

Publication number: JP3597995B2
Application number: JP21158798A
Authority: JP
Inventors: 健一米山; 清浩逆瀬川
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 1998-07-27
Filing date: 1998-07-27
Publication date: 2004-12-08
Anticipated expiration: 2018-07-27
Also published as: JP2000043257A

Description

【０００１】
【発明の属する技術分野】
本発明は、微細なノズル孔からインクを液滴として噴射して印字、画像等を形成する印刷用の各種プリンターや記録計、ファクシミリ、あるいは捺染分野や窯業分野で文様形成等に適用されるインク噴射装置等に用いられる高精度かつ軽量小型のインクジェットヘッドを有する印刷装置及びその製造方法に関するものである。
【０００２】
【従来の技術】
近年、マルチメディアの浸透に伴い、印版が不要で少量多品種の用途に適した小型軽量の各種情報の印刷用インターフェイスとして、従来のインパクト方式の印字装置に代わって、インク噴射装置や熱転写装置等を利用したノンインパクト方式の各種印刷装置が開発され、これらの利用範囲が各種産業分野に拡大している。
【０００３】
かかるノンインパクト方式の印刷装置のなかでも、前記インク噴射装置は、多階調化やカラー化が容易で、ランニングコストが低いことから将来性が注目されている。
【０００４】
前記インク噴射装置には、複数のノズル孔を有するノズル板と、インクの液滴を噴射させるための圧力を発生させるインク加圧室を主要な構成部品とするインクジェットヘッドが用いられており、該インクジェットヘッドは、一般的には、前記ノズル板と、該ノズル板のノズル孔からインクの液滴を色毎に個別に噴射させるために基板に隔壁を設けて溝を形成したインク加圧室と、該インク加圧室を密閉する蓋の役割を成す上部基板等から構成されている。
【０００５】
又、前記インクジェットヘッドにおいて、インク加圧室に圧力を発生させてインクの液滴を噴射する方式としては、必要なインクの液滴だけを噴射するドロップ・オン・デマンド型が主流になっており、例えば、カイザー型やサーマルジェット型が代表的な方式として採用されている。
【０００６】
前記カイザー型は、隔壁で複数の平行な溝を形成したインク加圧室を密閉する上部基板の少なくとも一部に薄壁を設け、該薄壁を圧電素子等で変形させてインク加圧室の溝の容積を変化させ、インク加圧室に内圧を発生させてインクを液滴として噴射させるものである。
【０００７】
又、前記サーマルジェット型は、前記インク加圧室内の一部に発熱体を設け、該インク加圧室内のインクを沸騰させた際の体積膨張を利用して内圧を発生させ、該インクを液滴として噴射させるものである。
【０００８】
しかしながら、前記カイザー型は、上部基板の表面に更に圧電素子等を設ける必要があることから、インクジェットヘッドとしては小型化が困難であり、又、前記サーマルジェット型は、インクに高熱を加えるためインク自体に耐熱性が要求され、インクの選択領域を狭めたり、インクを熱膨張させるために時間を要することから、応答性が劣る等の問題があった。
【０００９】
そこで、前記問題を解決するために、図６に示すような圧電材料から成る基板３０上に、平行に多数配置した溝３１を形成するための隔壁３２と、隔壁３２の側面に形成された電極３３と、隔壁３２の頂部に接合され、溝３１を密閉する上部基板３４とから成るインク加圧室３５と、インク加圧室３５の溝３１の開放端側に、溝３１と対応したノズル孔３６を有するノズル板３７を接合した構造を成すインクジェットヘッド３８から成る剪断モード型のインク噴射装置が提案されている。
【００１０】
この提案では、電極３３に駆動電圧を印加し、圧電材料の剪断モード変形を利用してインク加圧室３５の溝３１を形成する隔壁３２を歪み変形させて溝３１の容積を変化させることにより、溝３１中のインクを加圧し、溝３１に連通したノズル孔３６から、インクの液滴を噴射するものである（特開平７−２７６６４８号公報参照）。
【００１１】
【発明が解決しようとする課題】
前記提案の剪断モード型のインク噴射装置を構成するインクジェットヘッドは、従来のカイザー型やサーマルジェット型のように、上部基板表面に圧電素子等を設置させる必要がなく、又、インクに耐熱性が要求されることもないことから、小型化が可能となり、しかも応答性に優れ、高速の印刷が可能となる等、注目に値するものであった。
【００１２】
しかしながら、前記剪断モード型のインク噴射装置では、インクジェットヘッド３８のインク加圧室３５の溝３１を形成するのに、所要枚数重ねた薄い円盤状のダイヤモンドブレード等の切削具を回転しながら圧電材料から成る基板３０を切削して溝３１を刻設しているため、得られた溝３１の端部３９は、前記円盤状の切削具の曲率を転写した形状を成している。
【００１３】
従って、所望の噴射性能を得るためには、隔壁を歪み変形させてインク加圧室に十分な内圧を発生させることが必要となり、十分な隔壁駆動領域を確保しなければならないことから、前記未切削分を考慮して溝を長く設ける必要があり、インクジェットヘッド自体が大きくなると共に、材料コストが増加するという課題があった。
【００１４】
又、前記基板に溝を形成するに際しては、前述のような薄い円盤状のダイヤモンドブレード等の切削具を用いた加工方法では、切削条件が非常に難しく、送り速度、切り込み量、回転数等が適合しないと、ダイヤモンドブレード等の切削具自体がチッピングを起こしたりする等の課題もあった。
【００１５】
更に、得られた基板の溝は、切削具の断面形状が矩形状であることから該形状に相似した矩形状を呈し、隔壁頂部の上部基板との接合面積には限度を生じる結果、上部基板を接合する際に、接着剤が多いと該接着剤が溝にはみ出し易く、インク流路の容積がばらつき、インクの噴射特性が安定しなくなり、逆に接着剤が少ないと、接着不良を起こし、各インク加圧室を完全に密閉することができないという課題があり、接着歩留りの良い、量産に適した加工法であるとは言い難いものであった。
【００１６】
【発明の目的】
本発明は前記課題を解決するために成されたもので、その目的は、基板の溝幅が切削具の厚さに依存したり、溝の深さが切削具の切り込み量に依存したりせず、従来の切削具で生じる未切削部分を解消でき、しかも、隔壁の破損等の欠陥を低減でき、製造歩留りが向上すると共に、隔壁駆動領域が必要最小限の溝の長さで高精度に確保でき、その上、上部基板との接合歩留りが向上して安定したインクの噴射特性と、インクジェットヘッドの小型化及び材料コストの低減が可能となり、要求されている印字や画像、文様等のより高精細化が可能で、かつ量産に適したインクジェットヘッドから成るインク噴射装置を具備した印刷装置及びその製造方法を提供することにある。
【００１７】
【課題を解決するための手段】
本発明者等は、前記課題に鑑み鋭意検討した結果、剪断モード型のインク噴射装置において、上部基板を接合する隔壁の頂部の厚さが一定の範囲を確保できれば接着剤の塗布工程が容易かつ確実に行えて、十分な接着強度と高い接合信頼性が得られ、しかも、前記隔壁の成形方法を切削具を用いない、化学的処理あるいは熱処理により溶解あるいは分解して除去可能な隔壁成形型を用いた鋳込み成形法や転写法、印刷積層法等の成形方法を採用することにより、従来の加工法で残存していた曲率を有する未切削部分が不要となり隔壁駆動領域を拡大することができることから、前記溝の長さを必要最小限とすることができ、インクジェットヘッドの小型化及び高画質化が実現できることを見いだし、本発明に至った。
【００１８】
即ち、本発明の印刷装置は、基板の上に複数の隔壁を一体的に設けて平行な複数の溝を形成してなるインク加圧室構成部材と、前記溝の開放端側に接合してなり、ノズル孔を有するノズル板と、前記隔壁の頂部に接合された上部基板とを具備し、前記インク加圧室構成部材と、前記ノズル板と、前記上部基板でインク加圧室を形成し、前記隔壁が圧電性を有する材料から成り、該圧電性を有する材料の剪断モードにより前記隔壁を歪み変形させて溝の容積を変化させ、該溝に供給されたインクを該溝の一端に設けた前記ノズル孔から液滴として噴射するインクジェットヘッドをインク噴射装置として具備した印刷装置であって、前記隔壁の断面形状は、少なくとも隔壁の頂部側の側面が曲線状を成し、前記隔壁の頂部の厚さが該隔壁の最小の厚さより１５〜６０％大であるとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成すことを特徴とするものである。
【００１９】
とりわけ、前記隔壁の側面が全て曲線状を成すもの、曲線状とテーパー状を組み合わせたもの、又は複数の変曲点を有するものであることがより好ましく、更に、前記側面を階段状に変化させてなることが好ましい。
【００２０】
又、本発明の印刷装置の製造方法は、基板の上に複数の隔壁を一体的に設けて平行な複数の溝を形成してなるインク加圧室構成部材と、前記溝の開放端側に接合してなり、ノズル孔を有するノズル板と、前記隔壁の頂部に接合された上部基板とを具備するインクジェットヘッドをインク噴射装置として具備した印刷装置の製造方法であって、焼成後に少なくとも隔壁の頂部側の側面が曲線状を成し、該隔壁の頂部の厚さが該隔壁の最小の厚さより１５〜６０％大となるとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成す凹部を形成した隔壁成形型に、圧電性を有する材料から成る隔壁形成用組成物を充填して固化させた後、化学的処理により前記隔壁成形型を除去してから脱バインダー及び焼成して隔壁と基板を一体化するか、あるいは脱バインダー又は焼成の熱処理により前記隔壁成形型を分解除去すると同時に隔壁と基板を焼成一体化してインク加圧室構成部材を作成した後、隔壁の側面に電極を形成し、次いで隔壁の頂部に上部基板を接合すると共に、溝の開放端側にノズル孔を穿設したノズル板を接合してインク噴射装置を構成するインクジェットヘッドを形成することを特徴とするものである。
【００２１】
あるいは、本発明の印刷装置の他の製造方法として、基板の上に複数の隔壁を一体的に設けて平行な複数の溝を形成してなるインク加圧室構成部材と、前記溝の開放端側に接合してなり、ノズル孔を有するノズル板と、前記隔壁の頂部に接合された上部基板とを具備するインクジェットヘッドをインク噴射装置として具備した印刷装置の製造方法であって、焼成後に少なくとも隔壁の頂部側の側面が曲線状を成し、該隔壁の頂部の厚さが該隔壁の最小の厚さより１５〜６０％大となるとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成す凹部を形成した隔壁成形型に、圧電性を有する材料から成る隔壁形成用組成物を充填した後、基板を密着させて充填物を固化させ、次いで化学的処理により前記隔壁成形型を除去してから脱バインダー及び焼成して隔壁と基板を一体化するか、あるいは脱バインダー又は焼成の熱処理により前記隔壁成形型を分解除去すると同時に隔壁と基板を焼成一体化してインク加圧室構成部材を作成した後、隔壁の側面に電極を形成し、次いで隔壁の頂部に上部基板を接合すると共に、溝の開放端側にノズル孔を穿設したノズル板を接合してインク噴射装置を構成するインクジェットヘッドを形成する特徴とするものである。
【００２２】
特に、前記各印刷装置の製造方法で用いる隔壁成形型は、化学的処理あるいは熱処理により溶解あるいは分解除去可能な有機樹脂から成ることがより好適であり、更に、隔壁成形型として、基板上に感光性有機フィルムを接着して所定形状のマスクパターンを合わせて露光及び現像を行った後、マスクパターンを変更して前記工程を繰り返し、所定高さに積層して所定断面形状を有する溝部に該当する凸部を形成したものや、基板上に成形する隔壁の高さに相当する感光性レジスト層を形成し、所定のマスクパターンを合わせた後、露光及び現像を行って溝部に該当する凸部を形成したものが最も望ましいものである。
【００２３】
又、本発明の印刷装置の他の製造方法としては、基板の上に複数の隔壁を一体的に設けて平行な複数の溝を形成してなるインク加圧室構成部材と、前記溝の開放端側に接合してなり、ノズル孔を有するノズル板と、前記隔壁の頂部に接合された上部基板とを具備するインクジェットヘッドをインク噴射装置として具備した印刷装置の製造方法であって、基板上に所定形状の印刷製版を合わせてスクリーン印刷法にて圧電性を有する材料から成る隔壁形成用組成物を印刷して固化させた後、印刷製版を変更して前記印刷、固化工程を繰り返して隔壁形成用組成物を積層し、所定高さで焼成後に少なくとも隔壁の頂部側の側面が曲線状を成し、該隔壁の頂部の厚さが該隔壁の最小の厚さより１５〜６０％大となるとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成す断面形状を有する隔壁成形体を成形した後、脱バインダー及び焼成して隔壁と基板を一体化し、次いで隔壁の側面に電極を形成した後、隔壁の頂部に上部基板を接合すると共に、溝の開放端側にノズル孔を穿設したノズル板を接合してインク噴射装置を構成するインクジェットヘッドを形成することを特徴とするものである。
【００２４】
【作用】
本発明の印刷装置及びその製造方法によれば、隔壁の断面形状が、少なくとも隔壁の頂部側の側面が曲線状を成し、隔壁の頂部の厚さが該隔壁の最小の厚さより１５〜６０％大であるとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成す隔壁でインク加圧室を構成する複数の溝を形成することから、上部基板との接合面積が十分に確保され、接着剤の塗布工程が容易となって該接着剤のインク流路へのはみ出しや塗布不足が解消する上、十分な接着強度が得られる。
【００２５】
又、ダイヤモンドブレード等の切削具を用いることなく、化学的処理あるいは熱処理により溶解あるいは分解して除去可能な隔壁成形型を用いて鋳込み成形法や転写法、印刷積層法等の成形方法で、前記特徴を有する隔壁を成形することから、従来の切削にて基板の溝を形成した場合に見られた切削具の曲率を転写した形状を有する未研削部分を生ずることがないため、剪断モ―ドによる隔壁駆動領域が拡大され、同一のインク噴射特性を得るには溝の長さを従来よりも短くでき、インクジェットヘッド自体が小型軽量化され、材料コストも低減できると共に、かかるインクジェットヘッドから成るインク噴射装置の組み込み時の専有面積も大幅に低減され、引いては印刷装置自体の小型化にも寄与する。
【００２６】
更に、インクジェットヘッドが小型軽量化されることにより、インクジェットヘッドの移動速度の高速化、位置決め精度の向上にも寄与することになる。
【００２７】
【発明の実施の形態】
以下、本発明の印刷装置及びその製造方法について、図面に基づき詳細に説明する。
【００２８】
図１は、本発明の印刷装置を構成するインク噴射装置に用いられるインクジェットヘッドの一例である溝の長手方向に対して直角方向に切断した要部を示す断面図である。
【００２９】
図において、１はインク加圧室２を構成する基板３と、平行な複数の溝４を形成する隔壁５と、溝４の開放端側に接合したノズル孔６を穿設したノズル板７とを主要部とするインクジェットヘッドであり、隔壁５の頂部１３にはインク室（不図示）に連結する上部基板８が接合され、隔壁５の側面９には、駆動電界印加用の電極１０が形成されており、ノズル孔６はノズル板７に溝４と対応して列状に穿設されている。
【００３０】
本発明においては、隔壁５の頂部の厚さ１１が隔壁５の最小の厚さ１２より１５〜６０％大であることが必要なものであり、前記限定理由として隔壁５の頂部の厚さ１１が隔壁５の最小の厚さ１２より１５％未満となると、上部基板８との接合面積が小さくなり、正確に所定範囲で接着剤を塗布することが困難となり、６０％を越えると隔壁５の側面９に電極１０を形成することが困難となるためである。
【００３１】
従って、本発明では、隔壁５が前記条件を満足し、圧電性を有する材料の剪断モードにより隔壁５を歪み変形させて効率良く、かつ正確に再現性良く溝４の容積を変化できれるものであれば、その断面形状はいかなるものでも良い。
【００３２】
とりわけ、隔壁５の成形のし易さを考慮すると、少なくとも隔壁５の頂部１３側の側面９が曲線状を成す形状がより望ましい。
【００３３】
更に、隔壁５と上部基板８との接合歩留りが向上してより安定したインクの噴射特性が得られるという点では、隔壁５の頂部１３と基部１４の各端部を結ぶ直線１５が頂部１３の端部からの垂線と成す角度１６が、１〜３度であれば十分な接着面積が得られて接着歩留りが向上し、隔壁５の基部１４に応力が集中して隔壁５が成形時に破損する等の恐れもなく最適なものとなる。
【００３４】
従って、本発明の印刷装置を構成するインク噴射装置に用いられるインクジェットヘッドの隔壁の断面形状は、該インクジェットヘッドの他の例である溝の長手方向に対して直角方向に切断した要部を示す断面図である図２乃至図３に図示するように、隔壁５の側面９が全て全て曲線状を成すもの、あるいはテーパー状と曲面状を組み合わせたもの、複数の変曲点を有するもの等が適用可能であり、勿論、隔壁の厚さを階段状に変化させて構成しても、前記曲線状と階段状を組み合わせて隔壁の断面形状を形成しても良いことは言うまでもない。
【００３５】
尚、隔壁５のノズル孔６を穿設したノズル板７に接する側の厚さは、隔壁５の厚さの最大値となる形状が望ましく、その時の隔壁５の厚さは、ノズル孔６の大きさにより適宜選択できるが、概ねノズルピッチからノズル孔６の径の１．５倍の長さを差し引いた値を隔壁の最大値とすることができる。
【００３６】
次に、本発明の印刷装置の製造方法を、該印刷装置の要部を成すインク噴射装置を構成するインクジェットヘッドの製造工程を示す図４に基づき、その一例を説明する。
【００３７】
図４において、１は基板３と一体化した複数の平行な溝４を形成する隔壁５の頂部に接合した上部基板８と、溝４の開放端側に接合したノズル孔６を穿設したノズル板７とから成るインクジェットヘッドである。
【００３８】
本発明の印刷装置の製造方法として、先ず、隔壁形成用組成物を隔壁成形型の凹部に充填して隔壁を成形する方法では、基板３上に隔壁成形型１７を載置し、隔壁成形型１７と基板３で形成される凹部１８に隔壁形成用組成物１９を充填する工程から成る方法と、凹部１８を形成した隔壁成形型１７に隔壁形成用組成物１９を充填し、該充填物と接着するように基板３を押し付ける工程から成る方法がある。
【００３９】
本発明の基板３は、基板材料として隔壁と同一の圧電性を有する材料は勿論、隔壁と焼結後に一体化できるものであれば特に限定するものではなく、例えば、チタン酸ジルコン酸鉛系セラミックスやジルコニア等を挙げることができる。
【００４０】
次に、前記隔壁成形型１７は、前記詳述したように焼成後の前記隔壁の断面形状は、少なくとも隔壁の頂部側の側面が曲線状を成し、前記隔壁の頂部の厚さが該隔壁の最小の厚さより１５〜６０％大となる形状を成すとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成し、焼成収縮を考慮した凹部を設けたもので、その材質は、アルカリ液等の化学的処理により溶解できるもの、あるいは脱バインダー又は焼成の熱処理により分解揮散するものであれば特に限定するものではないが、前記いずれかの処理により除去可能なワックスや感光性有機レジストに代表される有機樹脂等が好適である。
【００４１】
とりわけ、前記隔壁成形型１７の隔壁形状を成す凹部１８を任意の形状に作製するという観点からは、基板上に感光性有機フィルムを接着して所定形状のマスクパターンを合わせて露光及び現像を行う工程を、マスクパターンを変更しながら繰り返し、所定高さで所定断面形状を有する溝部に該当する凸部を形成する方法、又は、基板上に成形する隔壁の高さに相当する感光性レジスト層を形成し、所定のマスクパターンを合わせた後、露光及び現像を行って溝部に該当する凸部を形成する方法が最適である。
【００４２】
具体的には、前記感光性レジスト層を形成させる手段は特に限定するものではないが、感光性レジスト層を液状のもので形成させる場合には、例えば、ロ―ルコーター法やドクターブレード法、スピンコーター法等により均一に塗布することができるが、均一膜厚を得易いという点からは感光性有機フィルムのように非液状のものを前記基板３に貼付して使用することが好ましく、その際、用いるマスクは、熱膨張の観点からはガラスマスクが好適である。
【００４３】
一方、前記露光の手段は、パターニングができれば特に限定するものではないが、電子線、紫外線、遠赤外線等を用いて露光することができ、コストや解像度の観点からは紫外線を用いた露光が好ましい。
【００４４】
次に、本発明で用いることができる圧電性を有する材料を含有した隔壁形成用組成物１９としては、特に限定するものではなく、圧電すべり効果や圧電縦効果、圧電横効果等の各種圧電モードを利用できるものであればいずれでも良いが、なかでもチタン酸ジルコン酸鉛系のセラミック材料が最適である。
【００４５】
又、前記隔壁形成用組成物１９は、圧電性を有する材料以外に各種樹脂、溶剤等から成るバインダ―溶液を混合したものであり、それ以外に分散剤、増粘剤等の各種添加剤を添加することもできる。
【００４６】
尚、前記隔壁成形型１７の凹部１８に隔壁形成用組成物１９を充填する手段としては、公知のドクターブレード法やロールコーター法、印刷法等を適用して充填することができるが、その際、充填後に脱気処理しても良く、又、脱気処理した泥漿を充填しても良い。
【００４７】
次に、隔壁成形型１７の凹部１８に充填した隔壁形成用組成物１９を固化させるが、固化させる手段は、選択した隔壁形成用組成物１９に用いた樹脂によって異なり、乾燥させたり、あるいは加熱硬化、常温硬化させても良く、最終的に隔壁形状を保形できるものであれば、固化させる手段は特に限定するものではない。
【００４８】
前記固化した隔壁形成用組成物１９を凹部１８に保持した隔壁成形型１７は、化学的処理あるいは脱バインダー又は焼成の熱処理により溶解あるいは分解揮散させて除去するが、その方法は特に限定されるものではなく、例えば、アルカリ液で溶解させたり、レーザ―等で焼成分解させたり、後述の脱バインダー又は焼成の熱処理により分解させ、別途あるいは前記熱処理と同時に焼成して基板と隔壁を一体化することにより、隔壁の断面形状は、少なくとも隔壁の頂部側の側面が曲線状を成し、隔壁の頂部の厚さが隔壁の最小の厚さより１５〜６０％大である断面形状を成すとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成し、該隔壁により複数の溝４を有するインク加圧室構成部材を作製することができる。
【００４９】
尚、必要に応じて引き出し電極用のわずかな空間を溝４の端部に機械加工にて形成することも可能である。
【００５０】
一方、本発明の印刷装置の他の製造方法は、図５に示すように、基板３上に前記圧電性を有する材料及びバインダー、各種有機添加物から成るペースト状の隔壁形成用組成物１９を印刷製版２０を用いて印刷法により印刷塗布し、次いで乾燥して隔壁形成用組成物１９を固化させる。
【００５１】
その際、隔壁の断面形状は、少なくとも隔壁の頂部側の側面が曲線状を成し、隔壁の頂部の厚さが隔壁の最小の厚さより１５〜６０％大である断面形状を成すとともに、前記隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と１〜３度の角度を成すように任意の形状で印刷製版を種々用意し、一層印刷、乾燥する度に印刷製版を調節しながら前記印刷、乾燥を繰り返して積層することにより、既述したような図１乃至図３に図示した断面形状を含む種々の形状の隔壁成形体２１を自由に基板３上に成形することができ、特に、前記印刷法としては、印刷製版の作り易さやコストの面からは、スクリーン印刷法が最適である。
【００５２】
かくして得られた隔壁を形成した基板を、公知の脱バインダー処理を施してから焼成することにより、基板と一体化した複数の平行な溝を有するインク加圧室構成部材が得られる。
【００５３】
その後、前記いずれの製造方法においても、隔壁の頂部から基部方向に分極処理を行い、基板と一体化した複数の平行な溝を有するインク加圧室構成部材を作製した後、隔壁側面の少なくとも一部及び溝の端部に設けたわずかな空間に、駆動電界印加用の電極１０と引き出し電極（不図示）を、例えば、スパッタリング法やめっき法、蒸着法、イオンプレーティング法、又はＣＶＤ法等により形成する。
【００５４】
かかる電極に適用できる材料としては、特に限定するものではないが、銅、銀、金、白金、タングステン、ニッケル等の金属材料や、ペロブスカイト系の導電性セラミックス材料等が好適に使用することができる。
【００５５】
他方、前記ノズル板７は、レーザー等で所定寸法に穿孔してノズル孔６を形成したもので、その材料としては、各種プラスチックや金属、セラミックス等のいかなる材料をも使用することができ、例えば、ポリエチレンテレフタレートやポリイミド、ポリエーテルイミド、ポリエーテルケトン、ポリエーテルスルホン、ポリカーボネイト、酢酸セルロース等のプラスチック、あるいはステンレス鋼やクロムモリブデン鋼、アルミニウム等の金属、もしくはアルミナやジルコニア、チタン酸ジルコン酸鉛等のセラミックスが挙げられるが、特に、加工のし易さの観点からは、ポリエチレンテレフタレートやポリイミドから成るプラスチック板が好適である。
【００５６】
かくして得られた部材をそれぞれエポキシ系接着剤等で接着して組み立てることにより、本発明の印刷装置を構成するインク噴射装置の剪断モード型のインクジェットヘッドが得られる。
【００５７】
尚、本発明の印刷装置では、噴射させるインクとしては顔料又は／及び染料と、水やアルコール等の水系の溶剤、あるいはヘキサンやトルエン等の非水系の溶剤を主成分としたもののいずれにも適用可能である。
【００５８】
【実施例】
次に、本発明の印刷装置及びその製造方法について、以下のようにして評価した。
【００５９】
（実施例１）厚さ約３００μｍのチタン酸ジルコン酸鉛系セラミック基板上に、チタン酸ジルコン酸鉛系セラミック粉末と有機バインダー、可塑剤、溶剤、分散剤とから成るペースト状の隔壁形成用組成物を調製し、該隔壁形成用組成物を用いて隔壁の厚さに相当する幅８０μｍに設定したスクリーン製版により隔壁パターンを印刷した後、乾燥した。
【００６０】
次いで、３回の印刷、乾燥を繰り返した後、幅７５、８０、８５μｍにそれぞれ設定したスクリ―ン製版を順次用いて、各々４回、印刷、乾燥を繰り返して積層印刷を行い、最後に隔壁の幅が９０μｍに相当するスクリーン製版で３回積層印刷すると共に、最上層は引き出し電極用の僅かな空間を有する様な製版パターンで印刷し、高さ約５００μｍの隔壁成形体を有する基板を作製した。
【００６１】
その後、４５０℃の温度で脱バインダー処理を行い、続いて１２００℃の温度で焼成して一体化し、インク加圧室構成部材を作製した後、引き出し電極用のわずかな空間を溝の端部にスライシング加工にて形成した。
【００６２】
その後、隔壁の分極処理を施し、更に隔壁の側面の上部半分と溝の引き出し電極相当部にスパッタリング法により金電極を形成した。
【００６３】
一方、厚さ約３００μｍの他のチタン酸ジルコン酸鉛系セラミック基板に機械加工によりインク室連結用の穴を形成して上部基板を作製した。
【００６４】
又、ポリイミド製のプラスチック板にレーザーでノズル孔を穿孔してノズル板を作製した。
【００６５】
かくして得られた各部材を、エポキシ系接着剤で接着して組み上げ、評価用の剪断モード型のインクジェットヘッドを作製した。
【００６６】
評価に際し、先ず、隔壁の断面形状を確認すべく同一仕様で作製したインク加圧室構成部材を溝の長手方向に対して直角方向に切断し、その断面を走査型電子顕微鏡で観察し、隔壁の頂部の厚さとして隔壁の頂点から隔壁基部に向かって１５μｍの位置の厚さを測定すると共に、隔壁の厚さの内、最小の厚さを有する位置で寸法を測定して隔壁の最小の厚さとし、前記最小の厚さに対する隔壁の頂部の厚さの増大割合を１００分率で計算し、その割合を求めた。
【００６７】
又、隔壁の頂部と基部の各端部を結ぶ直線が該頂部の端部からの垂線と成す角度を測定した。
【００６８】
次に、同一仕様の評価用の剪断モード型のインクジェットヘッドの一部を用いて、該インクジェットヘッドを治具に固定し、上部基板のみを毎秒０．５ｍｍの引っ張り速度で引っ張り試験を行い、剥離した時の荷重で密着性、即ち各インク加圧室の密閉性を評価した。
【００６９】
更に、作製した評価用の剪断モード型のインクジェットヘッドを用いてインク液滴の噴射実験を実施し、インク流路の容積のバラツキの有無をインクの噴射特性の内、各インク加圧室の液滴の噴射速度で評価した。
【００７０】
その結果、インク加圧室の隔壁は、頂部の厚さが８７μｍ、最小の厚さは７４μｍの隔壁の中央部付近の厚さとなり、隔壁の基部の厚さが８１μｍで、最小の厚さに対する頂部の厚さの増大割合は１８％となり、隔壁の高さが４００μｍで、印刷ダレによるやや鼓形状を呈する断面形状であった。
【００７１】
更に、溝の端部で長さ２ｍｍの引き出し電極相当部と溝部の長さが１０ｍｍで、溝のピッチは１５０μｍを示し、各インク加圧室の密閉性の評価としての接着強度は１．８ｋｇであった。
【００７２】
又、インク液滴の噴射実験で、隔壁駆動領域が十分に確保できてインク液滴も十分に噴射でき、しかも、該液滴の噴射速度も毎秒１４±０．８ｍと極めて安定しており、高精細度化が可能な小型のインクジェットヘッドが得られていることが確認できた。
【００７３】
又、インク流路の容積のバラツキは０．１５％程度と極めて小さくインク液滴量も安定しており、噴射特性の安定性が確認できた。
【００７４】
（実施例２）実施例１において、隔壁の幅が８０μｍに相当するスクリーン製版で１５回印刷積層し、その後、隔壁の幅が９０μｍに相当する製版で３回積層印刷する以外は、実施例１と同様にして剪断モード型のインクジェットヘッドを作製し、同様に評価した。
【００７５】
その結果、インク加圧室の隔壁は、頂部の厚さが８７μｍ、最小の厚さは７５μｍの隔壁の基部の厚さとなり、最小の厚さに対する頂部の厚さの増大割合は１６％であり、隔壁の高さが４００μｍで、印刷ダレにより隔壁の頂部付近で曲線状のＲ部を呈する断面形状であった。
【００７６】
更に、インク加圧室の溝の端部は溝底部からほぼ垂直に形成されており、溝の端部で長さ２ｍｍの引き出し電極相当部と溝部の長さが１０ｍｍで、溝のピッチが１５０μｍを示し、隔壁と上部基板との密着性、即ち各インク加圧室の密閉性の評価としての接着強度は１．８ｋｇであった。
【００７７】
又、インク液滴の噴射実験で、隔壁駆動領域が十分に確保できてインク液滴も十分に噴射でき、しかも、該液滴の噴射速度も毎秒１４±０．７ｍと極めて安定しており、高精細度化が可能な小型のインクジェットヘッドが得られていることが確認できた。
【００７８】
又、インク流路の容積のバラツキは０．１５％程度と極めて小さくインク液滴量も安定しており、噴射特性の安定性が確認できた。
【００７９】
（比較例）先ず、外形寸法で厚さ１ｍｍ、奥行き１２ｍｍ、幅１２ｍｍのチタン酸ジルコン酸鉛から成る基板に、ブレードの厚さが７０μｍのダイヤモンドブレードを用いてダイシング法により溝を切削加工してインク加圧室部材を作製し、隔壁に分極処理を施した後、隔壁側面の上部半分と溝の引き出し電極相当部にスパッタリング法により金電極を形成した。
【００８０】
一方、厚さ約３００μｍのチタン酸ジルコン酸鉛基板にインク室連結用の穴を研削により穿孔して上部基板を作製した。
【００８１】
他方、ポリイミド製のプラスチック板にレ―ザーでノズル穴を穿孔してノズル板を作製した。
【００８２】
次いで、エポキシ系接着剤で前記各部材を接着して組み上げ、剪断モード型のインクジェットヘッドを作製し、実施例１と同様にして評価した。
【００８３】
その結果、得られたインクジェットヘッドは、外形寸法が厚さ１ｍｍ、奥行き１２ｍｍ、幅１２ｍｍから成り、インク加圧室の溝は、溝の幅が７１μｍ、溝の深さが３００μｍの矩形断面を有すると共に、溝の端部は、ダイヤモンドブレードの曲率を転写した円弧形状を成しており、又、該溝を形成する隔壁の頂部及び基部の厚さは共に約６９μｍであり、溝の端部で長さ２ｍｍの引き出し電極相当部を有し、溝部の長さは１０ｍｍ、溝の底部の長さは７ｍｍ、未切削部分長さは３ｍｍもあり、溝のピッチは１４０μｍであった。また、接着強度は１．０ｋｇと低いものであった。
【００８４】
従って、インク液滴の噴射実験では、隔壁駆動領域が十分に確保できず、得られた印字は極めて粗いピッチであり、その上、スライシング加工の振動、ぶれ等により隔壁の一部欠損が２ヵ所、隔壁の基部からの破損が１ヵ所認められ、欠陥のないインクジェットヘッドが得られていなかった。
【００８５】
以上の結果からも明らかなように、比較例では、上部基板と接する側の溝部の長さが長いため、接着剤の垂れ込みの影響を受け易く、インク加圧室の容積のバラツキは±０．２５％程度と極めて大である。
【００８６】
又、スライシング加工時のダイヤモンドブレード等のツール形状に依存する未切削部分が生じるために十分な隔壁駆動領域を確保できないことから、インク液滴を十分に噴出できず、又、上部基板との接着強度は低い値を示し、信頼性の低いものであり、スライシング加工に起因する隔壁の欠損や破損を有するものであった。
【００８７】
それに対して、本発明では、いずれも隔壁と上部基板とが密閉性良く接合されており、インク流路の容積のバラツキも極めて軽微で、各インク加圧室のインク噴射特性も安定しており、その上、いずれも溝の全長が隔壁駆動領域として確保できてインク液滴を十分な圧力で噴射でき、噴出特性が優れた小型のインクジェットヘッドを形成できるだけでなく、例えば、ラインプリンターヘッドの如き長いヘッドを容易に作製できる。
【００８８】
尚、本発明は前記詳述した実施例に何等限定されるものではない。
【００８９】
【発明の効果】
叙上の如く、本発明の印刷装置及びその製造方法によれば、印刷装置に具備されたインク噴射装置を構成するインクジェットヘッドのインク加圧室の隔壁が、頂部の厚さが隔壁の最小の厚さより１５〜６０％大であることから、上部基板と隔壁の頂部との接合面積を大とすることができ、接着剤の量の多少を問わず十分な接着強度が得られると共に、インク流路の密閉性を確実なものとして、かつその容積のバラツキを解消し、接着剤の塗布工程が容易になる等により、上部基板との接合歩留りが向上して安定したインクの噴射特性が得られる。
【００９０】
その上、ダイヤモンドブレード等の切削具を用いない成形方法により隔壁を成形する製造方法であることから、従来のように基板の溝幅が切削具の厚さに依存したり、溝の深さが切削具の切り込み量に依存したりせず、更に、切削にて基板の溝を形成した場合に見られた切削具の曲率を転写した形状を有する未研削部分を生ずることがないため、剪断モードによる隔壁駆動領域が拡大でき、同一のインク噴射特性を得るには隔壁駆動領域が必要最小限の溝の長さで従来よりも短く高精度に確保でき、インクジェットヘッドが小型軽量化され、材料コストも低減できると共に、かかるインクジェットヘッドから成るインク噴射装置の組み込み時の専有面積も大幅に低減され、引いては印刷装置自体の小型化にも寄与することができる。
【００９１】
従って、インクジェットヘッドが小型軽量化されることにより、インクジェットヘッドの移動速度の高速化、位置決め精度の向上が実現でき、基板サイズを長尺化することにより、インクジェットヘッドを移動させる必要のないラインプリンターヘッドも簡単に製造することができ、高速、高解像度の印刷が可能となり、要求されている印字や画像、文様等のより高精細化が可能で、かつ量産に適したインクジェットヘッドから成るインク噴射装置を具備した印刷装置が得られる。
【図面の簡単な説明】
【図１】本発明の印刷装置を構成するインク噴射装置に用いられるインクジェットヘッドの一例である溝の長手方向に対して直角方向に切断した要部を示す断面図である。
【図２】本発明の印刷装置を構成するインク噴射装置に用いられるインクジェットヘッドの他の例である溝の長手方向に対して直角方向に切断した要部を示す断面図である。
【図３】本発明の印刷装置を構成するインク噴射装置に用いられるインクジェットヘッドの他の例である溝の長手方向に対して直角方向に切断した要部を示す断面図である。
【図４】本発明の印刷装置の製造方法を説明するための、印刷装置の要部を成すインク噴射装置を構成するインクジェットヘッドの製造工程の一例を示す図である。
【図５】本発明の印刷装置の製造方法を説明するための、印刷装置の要部を成すインク噴射装置を構成するインクジェットヘッドの製造工程の他の例を示す図である。
【図６】従来の印刷装置を構成するインク噴射装置に用いられる一部破断したインクジェットヘッドの構造を示す斜視図である。
【図７】従来の印刷装置を構成するインク噴射装置に用いられる一部破断したインクジェットヘッドの構造を示す斜視図である。
【符号の説明】
１インクジェットヘッド
２インク加圧室
３基板
４溝
５隔壁
６ノズル孔
７ノズル板
８上部基板
９側面
１０電極
１１頂部の厚さ
１２最小の厚さ
１３頂部
１４基部
１５直線
１６角度
１７隔壁成形型
１８凹部
１９隔壁形成用組成物
２０印刷製版
２１隔壁成形体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is applicable to various printers and recorders for printing to form printing, images, etc. by ejecting ink as droplets from fine nozzle holes, facsimile, or pattern forming in the printing field and ceramic industry. The present invention relates to a printing apparatus having a high-precision, lightweight, and small-sized inkjet head used for an ejection apparatus and the like, and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, with the spread of multimedia, as an interface for printing various types of small and lightweight information that is not required for printing plates and is suitable for many kinds of small quantities, ink jet devices and thermal transfer devices have replaced conventional impact printing devices. Various types of non-impact printing apparatuses utilizing such devices have been developed, and the range of use thereof has been expanded to various industrial fields.
[0003]
Among such non-impact printing apparatuses, the ink ejecting apparatus has attracted attention for its future potential because it is easy to increase the number of gradations and colors and the running cost is low.
[0004]
The ink ejecting apparatus includes a nozzle plate having a plurality of nozzle holes, and an ink jet head having an ink pressurizing chamber for generating pressure for ejecting ink droplets as a main component. Ink jet heads are generally provided with a nozzle plate and an ink pressurizing chamber in which a groove is formed by providing a partition on a substrate for individually ejecting ink droplets for each color from nozzle holes of the nozzle plate. And an upper substrate serving as a lid for sealing the ink pressurizing chamber.
[0005]
In the ink jet head, a drop-on-demand type in which only necessary ink droplets are ejected as a method of ejecting ink droplets by generating pressure in an ink pressurizing chamber has become mainstream. For example, a Kaiser type or a thermal jet type is adopted as a typical method.
[0006]
In the Kaiser type, a thin wall is provided on at least a part of an upper substrate that seals an ink pressurizing chamber in which a plurality of parallel grooves are formed by partition walls, and the thin wall is deformed by a piezoelectric element or the like to form the ink pressurizing chamber. By changing the volume of the groove, an internal pressure is generated in the ink pressurizing chamber, and the ink is ejected as droplets.
[0007]
In the thermal jet type, a heating element is provided in a part of the ink pressurizing chamber, and an internal pressure is generated by utilizing a volume expansion when the ink in the ink pressurizing chamber is boiled, and the ink is converted into a liquid. It is to be ejected as a drop.
[0008]
However, in the Kaiser type, since it is necessary to further provide a piezoelectric element or the like on the surface of the upper substrate, it is difficult to reduce the size of the ink jet head, and in the thermal jet type, high heat is applied to the ink. Since the ink itself is required to have heat resistance, and it takes a long time to narrow the selected area of the ink or to thermally expand the ink, there are problems such as poor response.
[0009]
In order to solve the above problem, a partition wall 32 for forming a large number of grooves 31 arranged in parallel on a substrate 30 made of a piezoelectric material as shown in FIG. 33 and an upper substrate 34 joined to the top of the partition wall 32 and sealing the groove 31. A nozzle hole corresponding to the groove 31 is formed at the open end side of the groove 31 of the ink pressure chamber 35. There has been proposed a shear mode type ink ejecting apparatus including an inkjet head 38 having a structure in which a nozzle plate 37 having a nozzle 36 is joined.
[0010]
In this proposal, a driving voltage is applied to the electrode 33, and the partition 32 forming the groove 31 of the ink pressurizing chamber 35 is deformed and deformed by utilizing the shear mode deformation of the piezoelectric material to change the volume of the groove 31. The ink in the groove 31 is pressurized, and the ink droplet is ejected from the nozzle hole 36 communicating with the groove 31 (see Japanese Patent Application Laid-Open No. 7-276648).
[0011]
[Problems to be solved by the invention]
The ink jet head constituting the proposed shear mode type ink ejecting apparatus does not require a piezoelectric element or the like to be provided on the upper substrate surface unlike a conventional Kaiser type or thermal jet type, and the ink has heat resistance. Since it is not required, it is notable that the device can be reduced in size, has excellent responsiveness, and enables high-speed printing.
[0012]
However, in the above-described shear mode type ink ejecting apparatus, in order to form the grooves 31 of the ink pressurizing chamber 35 of the ink jet head 38, the piezoelectric material is rotated while rotating a required number of cutting tools such as a thin disk-shaped diamond blade. Since the groove 31 is formed by cutting the substrate 30 made of, the end 39 of the obtained groove 31 has a shape obtained by transferring the curvature of the disc-shaped cutting tool.
[0013]
Therefore, in order to obtain a desired ejection performance, it is necessary to generate a sufficient internal pressure in the ink pressurizing chamber by deforming the partition wall, and it is necessary to secure a sufficient partition driving region. It is necessary to provide a long groove in consideration of the amount of cutting, which causes a problem that the ink jet head itself becomes large and the material cost increases.
[0014]
Further, when forming a groove in the substrate, in a processing method using a cutting tool such as a thin disk-shaped diamond blade as described above, the cutting conditions are very difficult, the feed rate, the cutting depth, the number of rotations, etc. If not, there is also a problem that the cutting tool itself such as a diamond blade causes chipping.
[0015]
Further, the groove of the obtained substrate has a rectangular shape similar to the cross-sectional shape of the cutting tool since the cross-sectional shape of the cutting tool is rectangular. At the time of joining, if there is a large amount of adhesive, the adhesive tends to protrude into the groove, the volume of the ink flow path varies, the ink ejection characteristics become unstable, and conversely, if the amount of the adhesive is small, adhesion failure occurs. There is a problem that the ink pressurizing chambers cannot be completely sealed, and it is hard to say that this is a processing method that has a good adhesion yield and is suitable for mass production.
[0016]
[Object of the invention]
The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to make the groove width of the substrate depend on the thickness of the cutting tool or the depth of the groove depends on the cutting amount of the cutting tool. In addition, the uncut portion generated by the conventional cutting tool can be eliminated, defects such as breakage of partition walls can be reduced, manufacturing yield can be improved, and the partition drive region can be formed with the minimum necessary groove length with high accuracy. In addition, the bonding yield with the upper substrate is improved, and the stable ink ejection characteristics, and the ink jet head can be made smaller and the material cost can be reduced. An object of the present invention is to provide a printing apparatus provided with an ink ejecting apparatus including an ink jet head which can be made high-definition and suitable for mass production, and a method of manufacturing the same.
[0017]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in view of the above problems, and as a result, in a shear mode type ink ejecting apparatus, if the thickness of the top of the partition wall joining the upper substrate can be secured in a certain range, the adhesive application step is easy and A partition mold that can be reliably performed, has sufficient adhesive strength and high bonding reliability, and can be removed by dissolving or decomposing by chemical treatment or heat treatment without using a cutting tool for the method of forming the partition. By adopting the molding method used such as the casting method, the transfer method, and the printing lamination method, the uncut portion having the curvature remaining by the conventional processing method becomes unnecessary, and the partition driving area can be enlarged. It has been found that the length of the groove can be minimized, and that the size and the image quality of the ink jet head can be reduced.
[0018]
That is, the printing apparatus of the present invention is configured such that a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, and the ink pressurizing chamber constituting member is joined to the open end side of the grooves. A nozzle plate having a nozzle hole, and an upper substrate joined to the top of the partition wall, wherein the ink pressurizing chamber forming member, the nozzle plate, and the upper substrate form an ink pressurizing chamber. The partition is made of a material having piezoelectricity, and the partition is deformed by a shear mode of the material having piezoelectricity to change the volume of the groove, and the ink supplied to the groove is provided at one end of the groove. A printing apparatus provided with an ink jet head that ejects droplets from the nozzle holes as an ink ejecting apparatus, wherein a cross-sectional shape of the partition wall has a curved side surface at least on a top side of the partition wall, and a top portion of the partition wall. Is the minimum thickness of the partition wall With 15 to 60% greater Halfbeak, in which a straight line connecting the ends of the top and base of said partition wall, characterized in that an angle of the perpendicular and 1-3 degrees from the end portion of said top.
[0019]
In particular, it is more preferable that all the side surfaces of the partition have a curved shape, a combination of a curved shape and a tapered shape, or a shape having a plurality of inflection points. Preferably.
[0020]
In addition, the method of manufacturing a printing apparatus according to the present invention includes an ink pressurizing chamber forming member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves; A method of manufacturing a printing apparatus, comprising: an ink jet device having an ink jet head including a nozzle plate having a nozzle hole and an upper substrate bonded to the top of the partition wall. The side surface on the top side is curved, the thickness of the top of the partition is 15 to 60% larger than the minimum thickness of the partition, and a straight line connecting the top of the partition and each end of the base is formed. After filling a partition forming composition made of piezoelectric material into a partition forming mold having a recess formed at an angle of 1 to 3 degrees with a perpendicular from the end of the top and solidifying the mold, a chemical treatment is performed. After removing the partition mold, remove the binder and After baking to integrate the partition and the substrate, or by disassembling and removing the partition forming mold by heat treatment of binder removal or baking, and simultaneously baking and integrating the partition and the substrate to form an ink pressurizing chamber constituent member, Forming an electrode on the side surface, then joining the upper substrate to the top of the partition, and joining a nozzle plate having a nozzle hole formed on the open end side of the groove to form an ink jet head constituting an ink ejecting apparatus. It is a feature.
[0021]
Alternatively, as another manufacturing method of the printing apparatus of the present invention, an ink pressurizing chamber constituting member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, and an open end of the grooves. A method for manufacturing a printing apparatus comprising an ink jet head having an ink jet head comprising a nozzle plate having a nozzle hole, and an upper substrate joined to the top of the partition wall, wherein The top side surface of the partition wall has a curved shape, the thickness of the top portion of the partition wall is 15 to 60% larger than the minimum thickness of the partition wall, and a straight line connecting the top portion of the partition wall and each end of the base. Is filled with a composition for forming a partition wall made of piezoelectric material into a partition wall mold having a recess formed at an angle of 1 to 3 degrees with a perpendicular from the end of the top, and then the substrate is brought into close contact and filled. Solidify and then by chemical treatment Either removing the partition mold and then removing the binder and firing to integrate the partition and the substrate, or decomposing and removing the partition mold by heat treatment for binder removal or firing and simultaneously firing and integrating the partition and the substrate After forming the pressurizing chamber constituent member, an electrode is formed on the side surface of the partition wall, and then the upper substrate is bonded to the top of the partition wall, and the nozzle plate having a nozzle hole formed on the open end side of the groove is bonded to the ink. This is a feature of forming an ink jet head constituting an ejection device.
[0022]
In particular, it is more preferable that the partition mold used in the manufacturing method of each of the printing apparatuses is made of an organic resin that can be dissolved or decomposed and removed by a chemical treatment or heat treatment. After bonding and exposure of the organic film and exposure and development in accordance with a mask pattern of a predetermined shape, the mask pattern is changed, and the above-described process is repeated. After forming a convex portion, a photosensitive resist layer corresponding to the height of the partition wall to be formed on the substrate is formed, and after adjusting a predetermined mask pattern, performing exposure and development to form a convex portion corresponding to the groove portion. The formed one is the most desirable one.
[0023]
Further, as another manufacturing method of the printing apparatus of the present invention, there are provided an ink pressurizing chamber constituting member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, A method for manufacturing a printing apparatus comprising an ink jet head as an ink ejecting apparatus, the ink jet head including a nozzle plate having a nozzle hole joined to an end side and having a nozzle hole, and an upper substrate joined to the top of the partition wall. After a printing plate having a predetermined shape is combined and printed and solidified with a partition wall forming composition made of a material having piezoelectricity by a screen printing method, the printing plate is changed, and the printing and solidifying steps are repeated to form a partition wall. After laminating the forming composition and firing at a predetermined height, at least the side surface on the top side of the partition wall has a curved shape, and the thickness of the top portion of the partition wall is 15 to 60% larger than the minimum thickness of the partition wall. Together with the top and base of the bulkhead After molding a partition wall molded body having a cross-sectional shape in which a straight line connecting each end forms an angle of 1 to 3 degrees with a perpendicular from the end of the top, the binder and the substrate are integrated by debinding and firing, and then After the electrodes are formed on the side surfaces of the partition, the upper substrate is joined to the top of the partition, and a nozzle plate having a nozzle hole formed on the open end side of the groove is joined to form an ink jet head constituting an ink ejecting apparatus. It is characterized by the following.
[0024]
[Action]
ADVANTAGE OF THE INVENTION According to the printing apparatus and its manufacturing method of the present invention, the cross-sectional shape of the partition wall is such that at least the side surface on the top side of the partition wall is curved, and the thickness of the top of the partition wall is 15 to 60 more than the minimum thickness of the partition wall. %, And a plurality of grooves forming an ink pressurizing chamber are formed by partition walls in which a straight line connecting the top of the partition and each end of the base forms an angle of 1 to 3 degrees with a perpendicular from the end of the top. Because of the formation, the bonding area with the upper substrate is sufficiently ensured, the application process of the adhesive becomes easy, the protrusion of the adhesive into the ink flow path and the insufficient application are eliminated, and the sufficient adhesive strength is obtained. can get.
[0025]
Also, without using a cutting tool such as a diamond blade, a molding method such as a casting method, a transfer method, and a printing lamination method using a partition wall mold capable of being dissolved or decomposed and removed by chemical treatment or heat treatment. Since the partition wall having the characteristic is formed, an unground portion having a shape in which the curvature of the cutting tool is transferred, which is observed when the groove of the substrate is formed by the conventional cutting, is not generated. In order to obtain the same ink jetting characteristics, the length of the groove can be made shorter than before, the ink jet head itself can be reduced in size and weight, the material cost can be reduced, and the ink comprising the ink jet head can be obtained. The area occupied by the ejecting device when it is installed is also greatly reduced, which also contributes to downsizing of the printing device itself.
[0026]
Further, the reduction in size and weight of the ink jet head contributes to an increase in the moving speed of the ink jet head and an improvement in positioning accuracy.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a printing apparatus and a manufacturing method thereof according to the present invention will be described in detail with reference to the drawings.
[0028]
FIG. 1 is a cross-sectional view showing a main part of a groove, which is an example of an ink jet head used in an ink ejecting apparatus constituting a printing apparatus of the present invention, cut in a direction perpendicular to a longitudinal direction of a groove.
[0029]
In FIG. 1, reference numeral 1 denotes a substrate 3 forming an ink pressurizing chamber 2, a partition wall 5 forming a plurality of parallel grooves 4, and a nozzle plate 7 having a nozzle hole 6 joined to an open end side of the groove 4. The upper part 8 connected to an ink chamber (not shown) is joined to the top part 13 of the partition 5 and the electrode 10 for applying a driving electric field is formed on the side surface 9 of the partition 5. The nozzle holes 6 are formed in the nozzle plate 7 in rows corresponding to the grooves 4.
[0030]
In the present invention, the thickness 11 at the top of the partition 5 needs to be 15 to 60% larger than the minimum thickness 12 of the partition 5. When the thickness is less than 15% than the minimum thickness 12 of the partition wall 5, the bonding area with the upper substrate 8 becomes small, and it becomes difficult to apply the adhesive accurately in a predetermined range. This is because it becomes difficult to form the electrode 10 on the side surface 9.
[0031]
Therefore, in the present invention, the partition wall 5 satisfies the above conditions, and the partition wall 5 can be deformed by the shear mode of the piezoelectric material, and the volume of the groove 4 can be changed efficiently and accurately with good reproducibility. If so, its sectional shape may be any.
[0032]
In particular, considering the ease of forming the partition wall 5, it is more desirable that at least the side surface 9 of the partition wall 5 on the side of the top 13 has a curved shape.
[0033]
Furthermore, a straight line 15 connecting the top 13 and each end of the base 14 of the partition 5 is formed by the straight line 15 of the top 13 in that the bonding yield between the partition 5 and the upper substrate 8 is improved and more stable ink ejection characteristics are obtained. If the angle 16 formed with the perpendicular from the end is 1 to 3 degrees, a sufficient bonding area can be obtained and the bonding yield is improved, stress is concentrated on the base 14 of the partition 5 and the partition 5 is broken at the time of molding. It becomes the most suitable without fear of etc.
[0034]
Therefore, the cross-sectional shape of the partition wall of the ink jet head used in the ink ejecting apparatus constituting the printing apparatus of the present invention indicates a main portion cut in a direction perpendicular to the longitudinal direction of the groove which is another example of the ink jet head. As shown in FIGS. 2 and 3 which are cross-sectional views, those in which all side surfaces 9 of the partition wall 5 form a curved shape, those in which a tapered shape is combined with a curved surface shape, those in which a plurality of inflection points are provided, and the like. The present invention is applicable. Needless to say, the sectional shape of the partition may be formed by changing the thickness of the partition in a stepwise manner or by combining the curved shape and the stepwise shape.
[0035]
The thickness of the partition wall 5 on the side in contact with the nozzle plate 7 in which the nozzle hole 6 is formed is desirably a shape having the maximum value of the thickness of the partition wall 5. Although it can be appropriately selected depending on the size, a value obtained by subtracting a length 1.5 times the diameter of the nozzle hole 6 from the nozzle pitch can be set as the maximum value of the partition wall.
[0036]
Next, an example of a method of manufacturing a printing apparatus according to the present invention will be described with reference to FIG. 4 showing a manufacturing process of an ink jet head constituting an ink ejecting apparatus which is a main part of the printing apparatus.
[0037]
In FIG. 4, reference numeral 1 denotes a nozzle having an upper substrate 8 joined to the top of a partition wall 5 forming a plurality of parallel grooves 4 integrated with the substrate 3 and a nozzle hole 6 joined to the open end side of the groove 4. An ink jet head comprising a plate 7.
[0038]
As a method for manufacturing a printing apparatus of the present invention, first, in a method of filling a concave portion of a partition wall forming mold with a composition for forming a partition wall to form a partition wall, a partition wall forming die 17 is placed on the substrate 3 and the partition wall forming die is placed. A step of filling the partition wall forming composition 19 into the concave portion 18 formed by the substrate 17 and the substrate 3, and a step of filling the partition wall forming composition 19 into the partition wall forming mold 17 in which the concave portion 18 is formed; There is a method that includes a step of pressing the substrate 3 so as to be bonded.
[0039]
The substrate 3 of the present invention is not particularly limited as long as it can be integrated with the partition after sintering, as well as a material having the same piezoelectricity as the partition as the substrate material. For example, lead zirconate titanate-based ceramics And zirconia.
[0040]
Next, as described above in detail, the partition wall forming mold 17 has a cross-sectional shape of the partition wall after firing, wherein at least the side surface on the top side of the partition wall is curved, and the thickness of the top of the partition wall is equal to the thickness of the partition wall. And a straight line connecting the top of the partition and each end of the base forms an angle of 1 to 3 degrees with a perpendicular from the end of the top, while forming a shape that is 15 to 60% larger than the minimum thickness of the partition, The material is provided with a concave portion in consideration of firing shrinkage, and its material is not particularly limited as long as it can be dissolved by a chemical treatment such as an alkali solution or can be decomposed and volatilized by heat treatment of debinding or firing. Suitable are waxes removable by any of the above-mentioned treatments, organic resins typified by photosensitive organic resists, and the like.
[0041]
In particular, from the viewpoint of forming the recess 18 forming the partition shape of the partition forming mold 17 into an arbitrary shape, a photosensitive organic film is adhered onto a substrate, and exposure and development are performed by matching a mask pattern of a predetermined shape. The process is repeated while changing the mask pattern, a method of forming a convex portion corresponding to a groove having a predetermined cross-sectional shape at a predetermined height, or a photosensitive resist layer corresponding to the height of the partition wall formed on the substrate. After forming and matching a predetermined mask pattern, a method of performing exposure and development to form a convex portion corresponding to the groove is optimal.
[0042]
Specifically, the means for forming the photosensitive resist layer is not particularly limited. When the photosensitive resist layer is formed of a liquid, for example, a roll coater method, a doctor blade method, Although it can be applied uniformly by a coater method or the like, it is preferable to use a non-liquid material such as a photosensitive organic film attached to the substrate 3 from the viewpoint of easily obtaining a uniform film thickness. The mask used is preferably a glass mask from the viewpoint of thermal expansion.
[0043]
On the other hand, the exposure means is not particularly limited as long as patterning can be performed, but exposure can be performed using an electron beam, ultraviolet light, far-infrared light, and the like, and exposure using ultraviolet light is preferable from the viewpoint of cost and resolution. .
[0044]
Next, the composition 19 for forming a partition wall containing a material having a piezoelectric property that can be used in the present invention is not particularly limited, and various piezoelectric modes such as a piezoelectric sliding effect, a piezoelectric longitudinal effect, and a piezoelectric transverse effect can be used. Any material can be used as long as it can be used, but among them, a lead zirconate titanate-based ceramic material is optimal.
[0045]
Further, the partition wall forming composition 19 is obtained by mixing a binder solution composed of various resins, solvents and the like in addition to the material having piezoelectricity, and further includes various additives such as a dispersant and a thickener. It can also be added.
[0046]
As a means for filling the concave portion 18 of the partition wall forming mold 17 with the partition wall forming composition 19, a known doctor blade method, a roll coater method, a printing method, or the like can be applied. After filling, degassing treatment may be performed, or degassed slurry may be filled.
[0047]
Next, the partition wall forming composition 19 filled in the concave portion 18 of the partition wall forming mold 17 is solidified. The means for solidifying depends on the resin used for the selected partition wall forming composition 19, and is dried or heated. The means for solidification is not particularly limited as long as it can be cured or cured at room temperature and can finally maintain the shape of the partition walls.
[0048]
The partition wall mold 17 holding the solidified partition wall forming composition 19 in the concave portion 18 is removed by dissolving or decomposing and volatilizing by heat treatment such as chemical treatment, binder removal or baking, but the method is not particularly limited. Rather, for example, dissolving with an alkali solution, baking and decomposing by laser or the like, decomposing by heat treatment of binder removal or baking described below, and baking separately or simultaneously with the heat treatment to integrate the substrate and the partition wall As a result, at least the side surface on the top side of the partition wall has a curved shape, the thickness of the top portion of the partition wall is 15 to 60% larger than the minimum thickness of the partition wall, The straight line connecting the top and each end of the base forms an angle of 1 to 3 degrees with the perpendicular from the end of the top, and the partition walls form an ink pressurizing chamber constituent member having a plurality of grooves 4. Seisuru can.
[0049]
If necessary, a small space for the extraction electrode can be formed at the end of the groove 4 by machining.
[0050]
On the other hand, as shown in FIG. 5, another manufacturing method of the printing apparatus according to the present invention is to form a paste-like partition wall forming composition 19 comprising the above-mentioned piezoelectric material, binder and various organic additives on a substrate 3. The composition is applied by printing using a printing plate 20 by a printing method, and then dried to solidify the partition wall forming composition 19.
[0051]
At that time, the cross-sectional shape of the partition wall is such that at least the side surface on the top side of the partition wall has a curved shape, and the thickness of the top of the partition wall is 15 to 60% larger than the minimum thickness of the partition wall, Various types of printing plates are prepared in any shape so that a straight line connecting the top of the partition and each end of the base forms an angle of 1 to 3 degrees with a perpendicular from the end of the top. By repeating the above-mentioned printing and drying while adjusting the printing plate making, the partition wall molded bodies 21 of various shapes including the cross-sectional shapes shown in FIGS. The screen printing method is most suitable as the printing method from the viewpoint of ease of making a printing plate and cost.
[0052]
The substrate on which the partition walls thus obtained are formed is subjected to a known binder removal treatment and then baked, whereby an ink pressurizing chamber constituting member having a plurality of parallel grooves integrated with the substrate is obtained.
[0053]
Thereafter, in any of the above-described manufacturing methods, after performing polarization processing in the base direction from the top of the partition wall to produce an ink pressurizing chamber constituent member having a plurality of parallel grooves integrated with the substrate, at least one of the side surfaces of the partition wall is formed. An electrode 10 for applying a driving electric field and an extraction electrode (not shown) are provided in a small space provided at the end of the portion and the groove, for example, by a sputtering method, a plating method, a vapor deposition method, an ion plating method, a CVD method, or the like. Formed by
[0054]
Materials that can be applied to such an electrode are not particularly limited, but metal materials such as copper, silver, gold, platinum, tungsten, and nickel, and perovskite-based conductive ceramic materials can be suitably used. .
[0055]
On the other hand, the nozzle plate 7 is formed by forming a nozzle hole 6 by piercing a predetermined size with a laser or the like. As the material, any material such as various plastics, metals, and ceramics can be used. Plastics such as polyethylene terephthalate, polyimide, polyetherimide, polyetherketone, polyethersulfone, polycarbonate, cellulose acetate, or metals such as stainless steel, chromium molybdenum steel, aluminum, or alumina, zirconia, lead zirconate titanate, etc. Of these, a plastic plate made of polyethylene terephthalate or polyimide is particularly preferable from the viewpoint of ease of processing.
[0056]
By assembling the members thus obtained by bonding them with an epoxy-based adhesive or the like, a shear mode ink jet head of an ink ejecting apparatus constituting the printing apparatus of the present invention can be obtained.
[0057]
In the printing apparatus of the present invention, the ink to be ejected is applied to any of pigments and / or dyes, and aqueous solvents such as water and alcohols, or non-aqueous solvents such as hexane and toluene. It is possible.
[0058]
【Example】
Next, the printing apparatus of the present invention and the method of manufacturing the same were evaluated as follows.
[0059]
Example 1 A composition for forming a paste-like partition wall comprising a lead zirconate titanate-based ceramic powder, an organic binder, a plasticizer, a solvent, and a dispersant, on a lead zirconate titanate-based ceramic substrate having a thickness of about 300 μm. An article was prepared, and a barrier rib pattern was printed using a screen plate having a width of 80 μm corresponding to the thickness of the barrier rib using the composition for forming a barrier rib, and then dried.
[0060]
Next, after repeating printing and drying three times, lamination printing was performed by repeating printing and drying four times each using a screen stencil set to a width of 75, 80, and 85 μm, and finally a partition wall. Is printed three times with a screen stencil having a width of 90 μm, and the uppermost layer is printed with a stencil pattern having a small space for a lead electrode to produce a substrate having a partition wall molded body having a height of about 500 μm. did.
[0061]
Thereafter, a binder removal treatment is performed at a temperature of 450 ° C., followed by baking at a temperature of 1200 ° C. to integrate the ink pressurizing chamber components, and a small space for a lead electrode is formed at an end of the groove. It was formed by slicing.
[0062]
Thereafter, the partition was polarized, and a gold electrode was formed by a sputtering method on the upper half of the side surface of the partition and the portion corresponding to the lead electrode of the groove.
[0063]
On the other hand, holes for ink chamber connection were formed in another lead zirconate titanate-based ceramic substrate having a thickness of about 300 μm by machining to form an upper substrate.
[0064]
Further, a nozzle plate was prepared by perforating a nozzle hole in a polyimide plastic plate with a laser.
[0065]
The members thus obtained were bonded together with an epoxy-based adhesive to assemble them, thereby producing a shear mode ink jet head for evaluation.
[0066]
At the time of evaluation, first, to confirm the cross-sectional shape of the partition, the ink pressurizing chamber constituent member manufactured with the same specifications was cut in a direction perpendicular to the longitudinal direction of the groove, and the cross section was observed with a scanning electron microscope. Measure the thickness at the position of 15 μm from the top of the partition wall toward the base of the partition wall as the thickness of the top of the partition wall, and measure the dimension at the position having the minimum thickness among the partition wall thicknesses to determine the minimum thickness of the partition wall. The percentage of increase in the thickness of the top of the partition wall relative to the minimum thickness was calculated as a percentage, and the percentage was determined.
[0067]
The angle formed by a straight line connecting the top of the partition and each end of the base with a perpendicular from the end of the top was measured.
[0068]
Next, using a part of the shear mode type inkjet head for evaluation of the same specification, the inkjet head was fixed to a jig, and only the upper substrate was subjected to a tensile test at a tensile speed of 0.5 mm / sec, and peeling was performed. The adhesiveness, that is, the tightness of each ink pressurized chamber, was evaluated by the load at the time of the above.
[0069]
Further, an ink droplet ejection experiment was performed using the prepared shear mode ink jet head for evaluation, and the presence or absence of variation in the volume of the ink flow path was checked by examining the presence or absence of variation in the volume of the ink flow path. The evaluation was made based on the drop ejection speed.
[0070]
As a result, the partition wall of the ink pressurizing chamber has a thickness of 87 μm at the top and a thickness of about 74 μm near the center of the partition wall with a minimum thickness of 74 μm, and the base thickness of the partition wall is 81 μm, which is smaller than the minimum thickness. The rate of increase in the thickness of the top portion was 18%, the height of the partition wall was 400 μm, and the cross-sectional shape had a slightly drum-shaped shape due to printing sag.
[0071]
Furthermore, the length of the groove portion is 10 mm, the length of the groove portion is 10 mm, the pitch of the groove is 150 μm, and the adhesive strength as an evaluation of the sealing property of each ink pressurizing chamber is 1.8 kg. Met.
[0072]
Also, in the experiment of ejecting ink droplets, the partition driving area can be sufficiently secured and the ink droplets can be sufficiently ejected, and the ejection speed of the droplets is extremely stable at 14 ± 0.8 m / sec. It was confirmed that a small inkjet head capable of achieving high definition was obtained.
[0073]
Further, the variation in the volume of the ink flow path was extremely small, about 0.15%, and the amount of ink droplets was also stable, confirming the stability of the ejection characteristics.
[0074]
(Example 2) Example 1 is the same as Example 1 except that printing and laminating are performed 15 times by screen plate making in which the width of the partition walls is equivalent to 80 µm, and then three times by using plate making in which the width of partition walls is equivalent to 90 µm. In the same manner as in the above, a shear mode type ink jet head was produced and evaluated in the same manner.
[0075]
As a result, the partition wall of the ink pressurizing chamber has a top thickness of 87 μm and a minimum thickness of 75 μm at the base of the partition wall, and the increase ratio of the top thickness to the minimum thickness is 16%. The height of the partition wall was 400 μm, and the cross-sectional shape was such that a curved R portion was exhibited near the top of the partition wall by printing sag.
[0076]
Further, the end of the groove of the ink pressurizing chamber is formed almost perpendicularly from the groove bottom, and the end of the groove has a portion corresponding to a 2 mm long extraction electrode, the length of the groove is 10 mm, and the pitch of the groove is 150 μm. The adhesive strength between the partition and the upper substrate, that is, the adhesive strength as an evaluation of the tightness of each ink pressurizing chamber was 1.8 kg.
[0077]
Also, in the experiment of ejecting ink droplets, the partition driving area can be sufficiently secured and the ink droplets can be sufficiently ejected, and the ejection speed of the droplets is extremely stable at 14 ± 0.7 m / sec. It was confirmed that a small inkjet head capable of achieving high definition was obtained.
[0078]
Further, the variation in the volume of the ink flow path was extremely small, about 0.15%, and the amount of ink droplets was stable, confirming the stability of the ejection characteristics.
[0079]
(Comparative Example) First, grooves were cut by dicing on a substrate made of lead zirconate titanate having a thickness of 1 mm, a depth of 12 mm, and a width of 12 mm using a diamond blade having a blade thickness of 70 μm. After preparing an ink pressurizing chamber member and performing polarization processing on the partition, a gold electrode was formed by a sputtering method on the upper half of the side surface of the partition and on a portion corresponding to the lead electrode of the groove.
[0080]
On the other hand, holes for connecting the ink chambers were drilled in a lead zirconate titanate substrate having a thickness of about 300 μm to form an upper substrate.
[0081]
On the other hand, a nozzle plate was formed by punching a nozzle hole with a laser on a polyimide plastic plate.
[0082]
Next, the above members were adhered to each other with an epoxy-based adhesive and assembled to produce a shear mode ink jet head, which was evaluated in the same manner as in Example 1.
[0083]
As a result, the obtained inkjet head has outer dimensions of 1 mm in thickness, 12 mm in depth, and 12 mm in width, and the groove of the ink pressurizing chamber has a rectangular cross section with a groove width of 71 μm and a groove depth of 300 μm. At the same time, the end of the groove has an arc shape in which the curvature of the diamond blade is transferred, and the thickness of the top and the base of the partition wall forming the groove is both about 69 μm. It had a 2 mm long extraction electrode equivalent part, the groove had a length of 10 mm, the bottom of the groove had a length of 7 mm, the uncut portion had a length of 3 mm, and the pitch of the groove was 140 μm. Further, the adhesive strength was as low as 1.0 kg.
[0084]
Therefore, in the experiment of ejecting ink droplets, the partition driving area could not be sufficiently secured, and the obtained print had an extremely coarse pitch. In addition, there were two defects in the partition due to vibrations and blurring of the slicing process. One breakage from the base of the partition wall was observed, and no defect-free inkjet head was obtained.
[0085]
As is clear from the above results, in the comparative example, since the length of the groove on the side in contact with the upper substrate is long, the groove is easily affected by the dripping of the adhesive, and the variation in the volume of the ink pressurizing chamber is ± 0. It is as large as about .25%.
[0086]
In addition, since an uncut portion depending on the tool shape such as a diamond blade at the time of slicing is generated, a sufficient partition driving region cannot be secured, so that ink droplets cannot be ejected sufficiently, and adhesion to the upper substrate is not achieved. The strength exhibited a low value, was low in reliability, and had breakage or breakage of the partition wall due to slicing.
[0087]
On the other hand, in the present invention, the partition wall and the upper substrate are all joined together with good sealing properties, the variation in the volume of the ink flow path is extremely small, and the ink ejection characteristics of each ink pressurizing chamber are stable. In addition, in each case, the entire length of the groove can be secured as a partition driving area, ink droplets can be ejected with sufficient pressure, and not only can a small inkjet head having excellent ejection characteristics be formed, but also, for example, a line printer head such as A long head can be easily manufactured.
[0088]
The present invention is not limited to the above-described embodiment.
[0089]
【The invention's effect】
As described above, according to the printing apparatus and the method of manufacturing the same of the present invention, the partition wall of the ink pressurizing chamber of the ink jet head constituting the ink ejecting apparatus provided in the printing apparatus has a minimum thickness of the top wall of the partition wall. Since the thickness is 15 to 60% larger than the thickness, the bonding area between the upper substrate and the top of the partition can be increased, sufficient adhesive strength can be obtained irrespective of the amount of the adhesive, and ink flow can be achieved. The sealing performance of the road is ensured, the variation in the volume is eliminated, and the application process of the adhesive is facilitated, so that the bonding yield with the upper substrate is improved and stable ink ejection characteristics can be obtained. .
[0090]
In addition, since it is a manufacturing method in which the partition wall is formed by a forming method that does not use a cutting tool such as a diamond blade, the groove width of the substrate depends on the thickness of the cutting tool or the depth of the groove is different from the conventional method. It does not depend on the cutting depth of the cutting tool, and furthermore, it does not generate an unground portion having a shape in which the curvature of the cutting tool transferred when the groove of the substrate is formed by cutting, so that the shear mode The partition driving area can be enlarged, and the partition driving area can be secured with a minimum necessary groove length and with higher precision than before in order to obtain the same ink jetting characteristics, and the ink jet head is reduced in size and weight, and the material cost is reduced. In addition to this, the area occupied by the ink ejecting apparatus including such an ink jet head when the ink ejecting apparatus is assembled is greatly reduced, and the printing apparatus itself can be reduced in size.
[0091]
Therefore, the inkjet head can be reduced in size and weight, so that the moving speed of the inkjet head can be increased and the positioning accuracy can be improved. By increasing the substrate size, a line printer that does not need to move the inkjet head can be realized. Heads can be easily manufactured, high-speed, high-resolution printing is possible, and the required high-definition of printing, images, and patterns can be achieved. A printing device equipped with the device is obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of a groove, which is an example of an ink jet head used in an ink ejecting apparatus constituting a printing apparatus of the present invention, cut in a direction perpendicular to a longitudinal direction of a groove.
FIG. 2 is a cross-sectional view showing a main part of another example of an ink jet head used in an ink ejecting apparatus constituting the printing apparatus of the present invention, which is cut in a direction perpendicular to a longitudinal direction of a groove.
FIG. 3 is a cross-sectional view showing a principal part of another example of an ink jet head used in an ink ejecting apparatus constituting the printing apparatus of the present invention, which is cut in a direction perpendicular to a longitudinal direction of a groove.
FIG. 4 is a view illustrating an example of a manufacturing process of an ink jet head constituting an ink ejecting apparatus which is a main part of the printing apparatus, for explaining a manufacturing method of the printing apparatus of the present invention.
FIG. 5 is a view illustrating another example of the manufacturing process of the ink jet head constituting the ink ejecting apparatus which is a main part of the printing apparatus, for explaining the manufacturing method of the printing apparatus of the present invention.
FIG. 6 is a perspective view showing a partially broken structure of an ink jet head used in an ink ejecting apparatus constituting a conventional printing apparatus.
FIG. 7 is a perspective view showing a partially broken structure of an ink jet head used in an ink ejecting apparatus constituting a conventional printing apparatus.
[Explanation of symbols]
1 inkjet head
2 Ink pressurizing chamber
3 substrate
4 grooves
5 Partition wall
6 Nozzle hole
7 Nozzle plate
8 Upper substrate
9 sides
10 electrodes
11 Top thickness
12 Minimum thickness
13 Top
14 Base
15 straight line
16 angles
17 Partition mold
18 recess
19 Composition for forming barrier ribs
20 Printing plate making
21 Partition wall molded body

Claims

An ink pressurizing chamber constituting member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, and a nozzle plate having a nozzle hole joined to an open end side of the groove, An upper substrate joined to the top of the partition wall, the ink pressurizing chamber forming member, the nozzle plate, and the upper substrate forming an ink pressurizing chamber, wherein the partition wall has a piezoelectric property. The partition wall is deformed by the shear mode of the piezoelectric material to change the volume of the groove, and the ink supplied to the groove is ejected as droplets from the nozzle hole provided at one end of the groove. A printing apparatus provided with an ink jet head as an ink ejecting apparatus, wherein the cross-sectional shape of the partition wall has a curved side surface at least on the top side of the partition wall, and the thickness of the top of the partition wall is the minimum of the partition wall. 15-60% larger than the thickness Together, the printing device a straight line connecting the ends of the top and base of said partition wall, characterized in that an angle of the perpendicular and 1-3 degrees from the end portion of said top.

2. The printing apparatus according to claim 1, wherein all of the side surfaces of the partition have a curved shape, a combination of a curved shape and a tapered shape, or a shape having a plurality of inflection points.

The printing apparatus according to claim 1, wherein the side surface is changed in a stepwise manner.

An ink pressurizing chamber constituting member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, and a nozzle plate having a nozzle hole joined to an open end side of the groove, A method of manufacturing a printing apparatus comprising an ink jet device having an ink jet head comprising an upper substrate joined to the top of the partition as an ink jetting device, wherein at least the top side of the partition has a curved side after firing. The thickness of the top of the partition is 15 to 60% larger than the minimum thickness of the partition, and the straight line connecting the top of the partition and each end of the base is 1 to 3 degrees with the perpendicular from the end of the top. After filling and solidifying the partition wall forming composition formed of a material having piezoelectricity into the partition wall forming mold in which the concave portion forming the angle is formed, removing the partition wall forming mold by a chemical treatment, then removing the binder and removing the binder. Baking to integrate the partition and substrate Alternatively, the partition wall mold is decomposed and removed by heat treatment of binder removal or firing, and at the same time, the partition wall and the substrate are fired and integrated to form an ink pressurizing chamber constituent member. A method of manufacturing a printing apparatus, comprising joining an upper substrate and joining a nozzle plate having a nozzle hole formed on an open end side of a groove to form an ink jet head constituting an ink ejecting apparatus.

An ink pressurizing chamber constituting member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, and a nozzle plate having a nozzle hole joined to an open end side of the groove, A method of manufacturing a printing apparatus comprising an ink jet device having an ink jet head comprising an upper substrate joined to the top of the partition as an ink jetting device, wherein at least the top side of the partition has a curved side after firing. The thickness of the top of the partition is 15 to 60% larger than the minimum thickness of the partition, and the straight line connecting the top of the partition and each end of the base is 1 to 3 degrees with the perpendicular from the end of the top. After filling the partition wall forming mold having a concave portion forming an angle with the partition wall forming composition made of a material having piezoelectricity, the substrate is brought into close contact to solidify the filler, and then the partition wall forming mold is subjected to a chemical treatment. After removing the binder and baking Then, the partition wall and the substrate are integrated, or the partition wall mold is decomposed and removed by heat treatment of binder removal or baking, and at the same time, the partition wall and the substrate are baked and integrated to form an ink pressurizing chamber constituent member, and the side surface of the partition wall is formed. Forming an ink jet head constituting an ink ejecting apparatus by joining an upper substrate to the top of the partition wall and joining a nozzle plate having a nozzle hole formed on the open end side of the groove. Manufacturing method of a printing apparatus.

The method according to claim 4, wherein the partition mold is made of an organic resin that can be dissolved or decomposed and removed by a chemical treatment or a heat treatment.

The partition mold has a predetermined cross-sectional shape at a predetermined height by repeating a process of bonding a photosensitive organic film on a substrate, performing exposure and development in accordance with a mask pattern of a predetermined shape while changing the mask pattern. The method according to any one of claims 4 to 6, wherein a protrusion corresponding to the groove is formed.

The partition mold was formed with a photosensitive resist layer corresponding to the height of the partition to be formed on the substrate, and after adjusting a predetermined mask pattern, exposed and developed to form a convex portion corresponding to the groove. The method of manufacturing a printing apparatus according to claim 4, wherein the printing apparatus is a printer.

An ink pressurizing chamber constituting member in which a plurality of partitions are integrally provided on a substrate to form a plurality of parallel grooves, and a nozzle plate having a nozzle hole joined to an open end side of the groove, A method of manufacturing a printing apparatus comprising, as an ink ejecting apparatus, an ink jet head having an upper substrate joined to the top of the partition wall, wherein a printing plate having a predetermined shape is combined on the substrate to perform piezoelectric printing by a screen printing method. After printing and solidifying the partition wall forming composition made of a material having properties, the printing plate is changed, the printing is repeated, and the solidifying step is repeated to laminate the partition wall forming composition, and at least after firing at a predetermined height, A side surface on the top side of the partition wall is curved, the thickness of the top portion of the partition wall is 15 to 60% larger than the minimum thickness of the partition wall, and a straight line connecting the top of the partition wall and each end of the base. Is perpendicular to the end of the top After molding a partition wall molded body having a cross-sectional shape forming an angle of up to 3 degrees, binder and substrate are integrated by binder removal and firing, and then an electrode is formed on the side surface of the partition wall, and then the upper substrate is placed on the top of the partition wall. A method of manufacturing a printing apparatus, comprising joining an ink jet head constituting an ink ejecting apparatus by joining a nozzle plate having a nozzle hole formed on an open end side of a groove.