JP2004098506A - Electrostatic actuator, liquid drop ejecting head and its manufacturing process, ink cartridge, inkjet recorder, micropump, and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that characteristic variation is significant and reliability is insufficient. <P>SOLUTION: Electrodes 24 are provided on a base substrate 21 while being divided by electrode dividing grooves 26 which are then filled with an insulating film 27 and flattened. Furthermore, a sacrifice layer is formed and after a diaphragm 22 is formed, the sacrifice layer is removed by etching to form a gap 23 thus constituting an actuator substrate 11. Surface of the actuator substrate 11 is formed flatly on the diaphragm 22 side. <P>COPYRIGHT: (C)2004,JPO

Description

【００４９】
なお、（１）式において、Ｆ：電極間に働く力、ε：誘電率、Ｓ：電極の対向する面の面積、ｄ：電極間距離、Ｖ：印加電圧である。
【００５０】
そこで、前述したように犠牲層エッチングでギャップ２３を形成することにより、高精度に微小なギャップを形成することができる。
【００５１】
次に、このインクジェットヘッドの製造方法の第１実施形態について図４ないし図６を参照して説明する。なお、図４及び図５は同製造方法の説明に供する断面説明図、図６は同じく平面説明図である。
ここでは、ベース基板に電極材料、犠牲層、振動板材料を成膜して行くことでアクチュエータ基板を製作する。
【００５２】
先ず、図４（ａ）に示すように、面方位（１００）のシリコン基板４１に絶縁膜となる熱酸化膜４５を例えばウエット酸化法により約１．０μｍの厚みに成膜する。その後、熱酸化膜４５上に個別電極となるポリシリコン４４を０．４μｍの厚みに成膜し、このポリシリコン４４に低抵抗化のために燐をドープする。そして、図６にも示すように、リソエッチ法により電極分離溝４６を形成した後、絶縁膜としての高温酸化膜（ＨＴＯ膜）４７を０．２５μｍ厚みに成膜する。このとき、電極分離溝４６はＨＴＯ膜４７で埋め込まれて電極となるポリシリコ４４表面を含めて平坦になる。なお、個別電極となるポリシリコン４４には図５に示すように電極パッド部５１も形成する。
【００５３】
次いで、同図（ｂ）に示すように、ＨＴＯ膜４３上に犠牲層となるポリシリコン４８を０．５μｍ厚みに成膜した後、図６にも示すように、リソエッチ法により分離溝５０を形成し、さらに絶縁膜としての高温酸化膜（ＨＴＯ膜）４２ｃを０．１μｍ厚みに成膜する。このとき、分離溝５０の幅は、ＨＴＯ膜４２ｃなどの振動板材料で埋め込まれる溝幅にすることが好ましく、振動板材料の厚みにもよるが２．０μｍ以下にすることが好ましい。ここでは、分離溝５０の幅を０．５μｍとし、ＨＴＯ膜４２ｃで埋め込まれるようにしている。
【００５４】
このように、犠牲層４８を溝５０で分離し、且つ絶縁膜４２ｃで埋め込むことにより、後工程において表面に段差の少ない略平坦な状態での作り込みが可能となり、アクチュエータ基板の表面の略平坦化を図れ、後工程のプロセス設計が容易となる。
【００５５】
さらに、同図（ｃ）に示すように、共通電極となるリンドープポリシリコン４２ａを０．２μｍ厚みに、次いで振動板保護膜となる酸化膜４２ｂを０．３μｍ厚みに成膜する。その後、リソエッチ法により犠牲層除去孔４９を後に液室間隔壁となる領域に形成するために、犠牲層除去孔４９よりオーバーサイズしたパターンをリソエッチ法により形成し、酸化膜４２ｂａ、ポリシリコン４２ａの順にエッチングを行なう。その後、酸化を行なって除去孔４９の側面に露出したポリシリコン４２ａ表面に酸化膜４２ａ１を形成する。
【００５６】
その後、図５（ａ）及び図６に示すように、リソエッチ法により除去孔４９のパターニングを行ない酸化膜（ＨＴＯ膜）４２ｃをエッチング除去し、ＳＦ_６を用いた等方性のドライエッチングにより犠牲層４８を除去してギャップ４３を形成する。なお、ＫＯＨやＴＭＡＨなどのアルカリエッチング液を用いたウェットエッチングでも良いし、ＸＦ_２ガスを用いた常圧ドライエッチングでも良い。
【００５７】
ここで犠牲層（ポリシリコン）４８の周りを酸化膜４７、４２ｃで囲んだ構造としているため、酸化膜に対して選択性の高い犠牲層エッチング条件で犠牲層４８を除去でき、ギャップ２３を精度よく形成することができる。また、分離溝５０で分離されたギャップ２３、２３間の犠牲層４８ａをギャップスペーサとして残存させることで、基板表面を略平坦に作り込むことができる。
【００５８】
なお、犠牲層除去孔４９の大きさによりエッチングガス（又は液）導入部のコンダクタンスが決定されるため、これが小さいと犠牲層除去時にガス（又は液）供給律速でエッチング速度が決定され、エッチング速度が遅くなるため、反応律速となる様に除去孔４９部のコンダクタンスを大きくする必要がある。このためには、除去孔４９の断面積がギャップ長の２乗よりもさらに大きくしておくことが好ましい。また、除去孔４９の配置間隔はギャップ部分の犠牲層を均等にエッチングできる様、ギャップの短辺長よりも小さいピッチで配置しておくことが好ましい。
【００５９】
その後、同図（ｂ）に示すように、上述のようにして得られたアクチュエータ基板１１に、液室（吐出室）６、共通液室８となる貫通部を形成した流路形成部材１２を接着剤で貼り合わせる。このとき、アクチュエータ基板１１表面は略平坦に形成されているので、容易に接着が可能である。また、流路形成部材１２で前記犠牲層除去孔４９を塞ぐことでギャップ２３を完全に封止することができる。
【００６０】
そして、図では省略したが、最後にノズル板２を流路形成部材１２表面に貼り合わせることで静電型液滴吐出ヘッドが完成する。
【００６１】
なお、ここでは、犠牲層４８にポリシリコンを用いたが、犠牲層として他の材料を使用することもできる。犠牲層にシリコン酸化膜を使用する場合は保護膜としてポリシリコンを用いる。犠牲層酸化膜をウエットエッチ法、ＨＦベーパー法、ケミカルドライエッチング法などにより除去後、保護膜としてポリシリコン表面を酸化することで絶縁層を形成する。
【００６２】
また、犠牲層にレジストを用いてＯ_２プラズマや剥離液で除去する方法や犠牲層に高分子材料を用いて有機系剥離液で除去する方法、犠牲層にアルミを用いてＫＯＨなどの薬液で除去する方法、犠牲層にＴｉＮ用いてＮＨ_３ＯＨとＨ_２Ｏ_２混合液などの薬液で除去する方法等、種々の組み合わせで上述したと同様のプロセスを組み立てることができる。
【００６３】
また、電極材料にはポリシリコン以外にも、前述したように、金属とシリコンの化合物である化合物シリサイドや高融点金属を用いることもできる。さらに、絶縁膜にＣＶＤ酸化膜、ポリシリコンに低温ポリシリコンを持ちいれば、アルミのような金属材料やＩＴＯ膜、ネサ膜（ＳｎＯ_２）等を電極材料として用いることもできる。
【００６４】
さらに、振動板表面にｐＨ値の高いアルカリ性インクに対する保護膜としてインクに対して耐腐食性を有する耐インク接液膜を成膜する場合において、アクチュエータ基板１１表面が略平坦であるのでスピンコート法により均一な接液膜を成膜することができる。
【００６５】
また、アクチュエータ基板１１表面が略平坦であるので、スピンコート法により塗布された感光性ポリイミドやＤＦＲで液室（吐出室）を形成することもできる。
【００６６】
このように、上記製造フローにより作製した静電型アクチュエータを含む液滴吐出ヘッドは、犠牲層膜厚によりギャップ間隔を規定するため、精度良く、且つバラツキの少ないギャップ形成が可能であり、特性（吐出特性）のバラツキが少なく、信頼性が向上し、高品質画像を記録することができるようになる。また、直接接合や陽極接合などが必要なく、２枚の基板で液滴吐出ヘッドを構成することができ、低コスト化を図れ、更に大半を半導体プロセスで作成できることから、歩留まり良く安定したヘッドを得ることができる。
【００６７】
また、アクチュエータ基板１１のベース基板にシリコン基板を用いることで、上記でも説明したような高温プロセスが使用できプロセス設計が容易となる。なお、高温プロセスとは、熱酸化、ＨＴＯやドープドポリシリコンを形成する熱ＣＶＤ、上質な窒化膜を形成するＬＰ−ＣＶＤ　等のプロセスを指す。加えて、電気的、機械的に優れた膜を選択でき信頼性の高い液滴吐出ヘッドが低コストで得られる。
【００６８】
次に、本発明の第２実施形態に係る液滴吐出ヘッドを構成する静電型アクチュエータについて図７及び図８を参照して説明する。なお、図７は同アクチュエータの振動板短手方向に沿う断面説明図、図８は同アクチュエータの１チャンネル分の平面説明図であり、同図（ａ）は電極分離溝を説明するための説明図、（ｂ）は犠牲層分離溝を説明するための説明図である。また、ここでは、前述した図４ないし図６の説明で用いた符号を用いて説明する。
【００６９】
このアクチュエータでは、図７及び図８（ａ）に示すように、電極４４、４４間に２本の分離溝４６、４６を形成している。したがって、分離溝４６、４６間には電極材料（電極部材）４４ａが残存する。また、２つの分離溝４６、４６間は、図８（ａ）に示すように、複数箇所に設けた架橋部４６ａで架橋している。
【００７０】
このように、電極間の分離溝を複数にすることによって、分離溝を狭くした場合でも、異物やパターン欠陥に起因するパターニング不良によって電極同士がショートする可能性を低減することができ、歩留まりが向上し、低コストで信頼性の高いヘッドが得られる。更に、複数の分離溝を架橋する架橋部を設ける、つまり、分離溝間に残存する電極材料を更に分割することによって、一層確実に電極同士がショートする可能性を低減することができる。
【００７１】
また、このアクチュエータでは、図７及び図８（ｂ）に示すように、ギャップ４３、４３間に犠牲層４８を分離するための３本の分離溝５０を形成している。したがって、分離溝５０、５０、５０間には犠牲層（犠牲層材料）４８ａ、４６ａが残存する。また、３つの分離溝５０、５０、５０間は、図８（ｂ）に示すように、複数箇所に設けた架橋部５０ａで架橋している。
【００７２】
このように、犠牲層の分離溝を３本以上にすることによって、異物やパターン欠陥に起因するパターニング不良によって、ギャップ相互間で連通する可能性を低減することができ、歩留まりが向上し、低コストで信頼性の高いヘッドが得られる。更に、３本以上の分離溝相互間を架橋する架橋部を設ける、つまり、分離溝間に残存する犠牲層を更に分割することによって、一層確実にギャップ間が連通する可能性を低減することができる。
【００７３】
次に、本発明の第３実施形態に係る液滴吐出ヘッドを構成する静電型アクチュエータについて図９を参照して説明する。
この実施形態は、電極２４の引出し部２４ａ上に犠牲層２８ｂを残存させたものであり、この犠牲層２８ｂは各ギャップ２３、２３間に残存する犠牲層２８ａ（図２参照）と一体である。このように、電極２４の引出し部２４ａ上にも犠牲層を残存させることによってアクチュエータ基板１１の表面をより平坦に作り込むことができる。
【００７４】
また、この実施形態では、犠牲層２８ａ、２８ｂとして、例えばポリシリコンにＰやＡｓ等の不純物をドープして導電性材料とし、振動板２２を貫通する接続部材６１を用いて各チャンネル間で犠牲層２８ｂを電気的に接続し、犠牲層２８ａ、２８ｂを基準電位に接続するようにしている。このように、少なくともギャップ２３、２３間に残存する犠牲層２８ａを電気的に基準電位に接続することによって、ギャップ間の容量を低下させることができ、安定したアクチュエータの高速駆動が可能になる。
【００７５】
この場合、基準電位は、グランド電位、振動板電位、電極電位、振動板及び電極電位の中間の電位等、駆動方法により最適な電位が異なるため、駆動方法に応じて最適な電位にすることが好ましい。
【００７６】
なお、図１０に示すように、電極２４の引出し部２４ａ上に部分的に犠牲層２８ｂを残存させることもできる。このようにすれば、アクチュエータ間の容量を少なくできアクチュエータの高速駆動が可能となり、また電極引出し部２４ａの強度を維持することができる。この場合、上述したように各ギャップ２３、２３間に残存する犠牲層２８ａ（図２参照）については基準電位に接続するようにすることで、よりアクチュエータ間の容量を少なくできアクチュエータの高速駆動が可能となる。
【００７７】
次に、本発明に係る液滴吐出ヘッドのインクカートリッジ一体型ヘッドについて図１１を参照して説明する。
このインクカートリッジ一体型ヘッド１００は、ノズル孔１０１等を有する上記各実施形態のいずれかのインクジェットヘッド１０２と、このインクジェットヘッド１０１に対してインクを供給するインクタンク１０３とを一体化したものである。
【００７８】
このように本発明に係る液滴吐出ヘッドにインクを供給するインクタンクを一体化することにより、滴吐出特性のバラツキが少なく、信頼性の高い液滴吐出ヘッドを一体化したインクカートリッジ（インクタンク一体型ヘッド）が低コストで得られる。
【００７９】
次に、本発明に係る液滴吐出ヘッドであるインクジェットヘッドを搭載したインクジェット記録装置の機構の一例について図１２及び図１３を参照して説明する。なお、図１２は同記録装置の斜視説明図、図１３は同記録装置の機構部の側面説明図である。
【００８０】
このインクジェット記録装置は、記録装置本体１１１の内部に主走査方向に移動可能なキャリッジ、キャリッジに搭載した本発明に係るインクジェットヘッドからなる記録ヘッド、記録ヘッドへインクを供給するインクカートリッジ等で構成される印字機構部１１２等を収納し、装置本体１１１の下方部には前方側から多数枚の用紙１１３を積載可能な給紙カセット（或いは給紙トレイでもよい。）１１４を抜き差し自在に装着することができ、また、用紙１１３を手差しで給紙するための手差しトレイ１１５を開倒することができ、給紙カセット１１４或いは手差しトレイ１１５から給送される用紙１１３を取り込み、印字機構部１１２によって所要の画像を記録した後、後面側に装着された排紙トレイ１１６に排紙する。
【００８１】
印字機構部１１２は、図示しない左右の側板に横架したガイド部材である主ガイドロッド１２１と従ガイドロッド１２２とでキャリッジ１２３を主走査方向（図１２で紙面垂直方向）に摺動自在に保持し、このキャリッジ１２３にはイエロー（Ｙ）、シアン（Ｃ）、マゼンタ（Ｍ）、ブラック（Ｂｋ）の各色のインク滴を吐出する本発明に係る液滴吐出ヘッドであるインクジェットヘッドからなるヘッド１２４を複数のインク吐出口を主走査方向と交叉する方向に配列し、インク滴吐出方向を下方に向けて装着している。またキャリッジ１２３にはヘッド１２４に各色のインクを供給するための各インクカートリッジ１２５を交換可能に装着している。なお、本発明に係るインクカートリッジを搭載する構成とすることもできる。
【００８２】
インクカートリッジ１２５は上方に大気と連通する大気口、下方にはインクジェットヘッドへインクを供給する供給口を、内部にはインクが充填された多孔質体を有しており、多孔質体の毛管力によりインクジェットヘッドへ供給されるインクをわずかな負圧に維持している。
【００８３】
また、記録ヘッドとしてここでは各色のヘッド１２４を用いているが、各色のインク滴を吐出するノズルを有する１個のヘッドでもよい。
【００８４】
ここで、キャリッジ１２３は後方側（用紙搬送方向下流側）を主ガイドロッド１２１に摺動自在に嵌装し、前方側（用紙搬送方向上流側）を従ガイドロッド１２２に摺動自在に載置している。そして、このキャリッジ１２３を主走査方向に移動走査するため、主走査モータ１２７で回転駆動される駆動プーリ１２８と従動プーリ１２９との間にタイミングベルト１３０を張装し、このタイミングベルト１３０をキャリッジ１２３に固定しており、主走査モーター１２７の正逆回転によりキャリッジ１２３が往復駆動される。
【００８５】
一方、給紙カセット１１４にセットした用紙１１３をヘッド１２４の下方側に搬送するために、給紙カセット１１４から用紙１１３を分離給装する給紙ローラ１３１及びフリクションパッド１３２と、用紙１１３を案内するガイド部材１３３と、給紙された用紙１１３を反転させて搬送する搬送ローラ１３４と、この搬送ローラ１３４の周面に押し付けられる搬送コロ１３５及び搬送ローラ１３４からの用紙１１３の送り出し角度を規定する先端コロ１３６とを設けている。搬送ローラ１３４は副走査モータ１３７によってギヤ列を介して回転駆動される。
【００８６】
そして、キャリッジ１２３の主走査方向の移動範囲に対応して搬送ローラ１３４から送り出された用紙１１３を記録ヘッド１２４の下方側で案内する用紙ガイド部材である印写受け部材１３９を設けている。この印写受け部材１３９の用紙搬送方向下流側には、用紙１１３を排紙方向へ送り出すために回転駆動される搬送コロ１４１、拍車１４２を設け、さらに用紙１１３を排紙トレイ１１６に送り出す排紙ローラ１４３及び拍車１４４と、排紙経路を形成するガイド部材１４５，１４６とを配設している。
【００８７】
記録時には、キャリッジ１２３を移動させながら画像信号に応じて記録ヘッド１２４を駆動することにより、停止している用紙１１３にインクを吐出して１行分を記録し、用紙１１３を所定量搬送後次の行の記録を行う。記録終了信号または、用紙１１３の後端が記録領域に到達した信号を受けることにより、記録動作を終了させ用紙１１３を排紙する。
【００８８】
また、キャリッジ１２３の移動方向右端側の記録領域を外れた位置には、ヘッド１２４の吐出不良を回復するための回復装置１４７を配置している。回復装置１４７はキャップ手段と吸引手段とクリーニング手段を有している。キャリッジ１２３は印字待機中にはこの回復装置１４７側に移動されてキャッピング手段でヘッド１２４をキャッピングされ、吐出口部を湿潤状態に保つことによりインク乾燥による吐出不良を防止する。また、記録途中などに記録と関係しないインクを吐出することにより、全ての吐出口のインク粘度を一定にし、安定した吐出性能を維持する。
【００８９】
吐出不良が発生した場合等には、キャッピング手段でヘッド１２４の吐出口（ノズル）を密封し、チューブを通して吸引手段で吐出口からインクとともに気泡等を吸い出し、吐出口面に付着したインクやゴミ等はクリーニング手段により除去され吐出不良が回復される。また、吸引されたインクは、本体下部に設置された廃インク溜（不図示）に排出され、廃インク溜内部のインク吸収体に吸収保持される。
【００９０】
このように、このインクジェット記録装置においては本発明に係る液滴吐出ヘッドであるインクジェットヘッドを搭載しているので、インク滴の吐出特性のバラツキが少なく、高い画像品質の画像を記録できる記録装置が得られる。
【００９１】
次に、本発明に係る静電型アクチュエータを備えたマイクロデバイスとしてのマイクロポンプについて図１４を参照して説明する。なお、同図は同マイクロポンプの要部断面説明図である。
このマイクロポンプは、流路基板２０１と本発明に係る静電型アクチュエータを構成するアクチュエータ基板２０２とを有している。流路基板２０１には流体が流れる流路２０３を形成している。アクチュエータ基板２０２は、ベース基板２２１上に設けた、流路２０１の壁面を形成する変形可能な振動板（可動板）２２２と、この振動板２２２の変形可能部２２２ａに所定のギャップ２２３を置いて対向する電極２２４とを含み、表面が略平坦面に形成されている。なお、アクチュエータ基板２０２の詳細な説明は省略するが、前記インクジェットヘッドの実施形態で説明したと同様である。
【００９２】
このマイクロポンプの動作原理を説明すると、前述したインクジェットヘッドの場合と同様に、電極２２４に対して選択的にパルス電位を与えることによって振動板２２２との間で静電吸引力が生じるので、振動板２２２の変形可能部２２２ａが電極２２４側に変形する。ここで、振動板２２２の変形可能部２２２ａを図中右側から順次駆動することによって流路２０１内の流体は、矢印方向へ流れが生じ、流体の輸送が可能となる。
【００９３】
この場合、本発明に係る静電型アクチュエータを備えることで、特性バラツキが少なく、安定した液体輸送を可能な小型で低消費電力のマイクロポンプを得られる。なお、ここでは振動板の変形可能部が複数ある例を示したが、変形可能部は１つでも良い。また、輸送効率を上げるために、変形可能部間に１又は複数の弁、例えば逆止弁などを設けることもできる。
【００９４】
次に、本発明に係る静電型アクチュエータを備えた光学デバイスの一例について図１５を参照して説明する。なお、同図は同デバイスの概略構成図である。
この光学デバイスは、表面が光を反射可能でかつ変形可能なミラー３０１を含むアクチュエータ基板３０２を有している。ミラー３０１の表面は反射率を増加させるため誘電体多層膜や金属膜を形成すると良い。
【００９５】
アクチュエータ基板３０２は、ベース基板３２１上に設けた、変形可能なミラー３０１（ヘッドの振動板に相当する。）と、このミラー３０１の変形可能部３０１に所定のギャップ３２３を介して対向する電極３２４とを含み、ミラー３０１の表面が略平坦に形成されている。このアクチュエータ基板３０２についても、振動板がミラー面を有する構成となっている点が前記インクジェットヘッドの実施形態で説明したものと異なるだけであるので、詳細な説明を省略する。
【００９６】
この光学デバイスの原理を説明すると、前述したインクジェットヘッドの場合と同様に、電極３２４に対して選択的にパルス電位を与えることによって、電極３２４と対向するミラー３０１の変形可能部３０１ａ間で静電吸引力が生じるので、ミラー３０１の変形可能部３０１が凹状に変形して凹面ミラーとなる。したがって、光源３１０からの光がレンズ３１１を介してミラー３０１に照射した場合、ミラー３０１を駆動しないときには、光は入射角と同じ角度で反射するが、ミラー３０１を駆動した場合は駆動された変形可能部３０１が凹面ミラーとなるので反射光は発散光となる。これにより光変調デバイスが実現できる。
【００９７】
そして、本発明に係る静電型アクチュエータを備えることで、特性バラツキの少ない小型で低消費電力の光学デバイスを得ることができる。
【００９８】
そこで、この光学デバイスを応用した例を図１６をも参照して説明する。この例は、上述した光学デバイスを２次元に配列し、各ミラー３０１の変形可能部３０１ａを独立して駆動するようにしたものである。なお、ここでは、４×４の配列を示しているが、これ以上配列することも可能である。
【００９９】
したがって、前述した図１５と同様に、光源３１０からの光はレンズ３１１を介してミラー３０１に照射され、ミラー３０１を駆動していないところに入射した光は、投影用レンズ３１２へ入射する。一方、電極３２４に電圧を印加してミラー３０１の変形可能部３０１ａを変形させている部分は凹面ミラーとなるので光は発散し投影用レンズ３１２にほとんど入射しない。この投影用レンズ３１２に入射した光はスクリーン（図示しない）などに投影され、スクリーンに画像を表示することができる。
【０１００】
なお、上記実施形態においては、液滴吐出ヘッドとしてインクジェットヘッドに適用した例で説明したが、インクジェットヘッド以外の液滴吐出ヘッドとして、例えば、液体レジストを液滴として吐出する液滴吐出ヘッド、ＤＮＡの試料を液滴として吐出する液滴吐出ヘッドなどの他の液滴吐出ヘッドにも適用できる。また、静電型アクチュエータは、マイクロポンプ、光学デバイス（光変調デバイス）以外にも、マイクロスイッチ（マイクロリレー）、マルチ光学レンズのアクチュエータ（光スイッチ）、マイクロ流量計、圧力センサなどにも適用することができる。
【０１０１】
【発明の効果】
以上説明したように、本発明に係る静電型アクチュエータによれば、ベース基板上に変形可能な振動板とこれに所定のギャップを置いて対向する電極とを備え、振動板と電極との間のギャップは犠牲層エッチングにより形成され、かつ、このアクチュエータの振動板側の表面が略平坦である構成としたので、特性バラツキが少なく、低コスト化を図れ、信頼性を向上できる。
【０１０２】
本発明に係る液滴吐出ヘッドによれば、液滴を吐出するノズルが連通する加圧液室内の液体を加圧するための本発明に係る静電型アクチュエータを構成するアクチュエータ基板と、加圧液室を形成する流路形成部材とを備えている構成としたので、滴吐出特性のバラツキが少なく、低コスト化を図れ、信頼性が向上する。
【０１０３】
本発明に係るインクカートリッジによれば、本発明に係る液滴吐出ヘッドとこの液滴吐出ヘッドにインクを供給するインクタンクを一体化したので、滴吐出特性のバラツキが少なく、低コスト化を図れ、信頼性が向上する。
【０１０４】
本発明に係るインクジェット記録装置によれば、インク滴を吐出する本発明に係る液滴吐出ヘッド、または本発明に係るインクカートリッジを搭載したので、高画質記録が可能になる。
【０１０５】
本発明に係るマイクロポンプによれば、流路の液体を加圧する本発明に係る静電型アクチュエータを構成するアクチュエータ基板と流路を形成する流路形成部材とを備えているので、小型で低消費電力のマイクロポンプが得られる。
【０１０６】
本発明に係る光学デバイスによれば、光を反射するミラーを変形させるための本発明に係る静電型アクチュエータを構成するアクチュエータ基板を備えているので、小型で低消費電力の光学デバイスが得られる。
【０１０７】
本発明に係る液滴吐出ヘッドの製造方法によれば、ベース基板上に形成した電極部材を複数の電極に分離溝で分離する工程と、分離溝を絶縁膜で埋め込んで平坦化する工程と、絶縁膜上に犠牲層を形成する工程と、犠牲層上に耐エッチング性を有する膜を含む振動板部材を形成する工程と、振動板部材に開口を形成した後犠牲層をエッチング除去する工程とを含む構成としたので、アクチュエータの振動板側の表面が略平坦であるヘッドを容易に得ることができる。
【図面の簡単な説明】
【図１】本発明の液滴吐出ヘッドの第１実施形態に係るインクジェットヘッドの分解斜視説明図
【図２】同ヘッドの振動板短手方向に沿う断面説明図
【図３】同ヘッドの振動板長手方向に沿う断面説明図
【図４】本発明の液滴吐出ヘッドであるインクジェットヘッドの製造方法の実施形態の説明に供する断面説明図
【図５】図４に続く工程を説明する断面説明図
【図６】同工程の説明に供する平面説明図
【図７】本発明に係る液滴吐出ヘッドの第２実施形態を構成する静電型アクチュエータの断面説明図
【図８】同アクチュエータの平面説明図
【図９】本発明に係る液滴吐出ヘッドの第３実施形態のインクジェットヘッドを説明する振動板長手方向に沿う断面説明図
【図１０】同実施形態の他の例を説明する断面説明図
【図１１】本発明に係るインクカートリッジの説明に供する斜視説明図
【図１２】本発明に係るインクジェット記録装置の一例を説明する斜視説明図
【図１３】同記録装置の機構部の説明図
【図１４】本発明にマイクロポンプの一例を説明する説明図
【図１５】本発明に係る光学デバイスの一例を説明する説明図
【図１６】同光学デバイスを用いた光変調デバイスの一例を説明する斜視説明図
【符号の説明】
１…第１基板、２…第２基板（ノズル板）、４…ノズル孔、６…吐出室、７…流体抵抗部、８…共通液室、１１…アクチュエータ基板、１２…流路形成部材、２１…ベース基板、２２…振動板、２３…ギャップ、２４…電極、１００…インクカートリッジ、１２４…記録ヘッド、２０１…流路基板、２０３…流路、２０２…アクチュエータ基板、２２２ａ…変形可能部、２４６…電極、３０１…ミラー、３０１ａ…変形可能部、３０２…アクチュエータ基板、３２４…電極。[0001]
[Industrial applications]
The present invention relates to an electrostatic actuator, a droplet discharge head and a method for manufacturing the same, an ink cartridge, an ink jet recording apparatus, a micropump, and an optical device.
[0002]
[Prior art]
[Patent Document 1] JP-A-6-71882
[Patent Document 2] JP-A-2001-18383
[Patent Document 3] Japanese Patent Application Laid-Open No. 11-314363
[0003]
An inkjet head, which is a droplet ejection head used in an image recording apparatus such as a printer, a facsimile, and a copying apparatus or an inkjet recording apparatus used as an image forming apparatus, includes a single or a plurality of nozzle holes for discharging ink droplets, and the nozzle holes. A discharge chamber (also referred to as a pressure chamber, an ink chamber, a liquid chamber, a pressurized liquid chamber, a pressure chamber, an ink flow path, etc.) communicating with the pressure chamber, and a pressure generating means for generating a pressure for pressurizing the ink in the discharge chamber. Ink is ejected from the nozzle holes by pressurizing the ink in the ejection chamber with the pressure generated by the pressure generating means.
[0004]
The droplet discharge head includes, for example, a droplet discharge head that discharges a liquid resist as droplets, a droplet discharge head that discharges a DNA sample as droplets, and the like. . The microactuator constituting the actuator of the droplet discharge head includes, for example, a micropump, an optical device such as a micro light modulation device, a micro switch (micro relay), a multi-optical lens actuator (optical switch), a micro flow meter, a pressure sensor, and the like. It can also be applied to sensors and the like.
[0005]
By the way, as a droplet discharge head, a piezo type that discharges ink droplets by deforming and displacing a diaphragm forming a wall surface of a discharge chamber using an electromechanical transducer such as a piezoelectric element as a pressure generating means. A thermal type in which bubbles are generated by ink film boiling using an electrothermal conversion element such as a heating resistor disposed in a discharge chamber to discharge ink droplets, and a vibrating plate forming a wall surface of the discharge chamber is statically moved. There is an electrostatic type in which ink droplets are ejected by being deformed by electric power.
[0006]
In recent years, a bubble type and an electrostatic type, which are lead-free due to environmental problems, have attracted attention. In addition to lead-free, a plurality of electrostatic types have been proposed which have little effect on the environment from the viewpoint of low power consumption.
[0007]
As this electrostatic ink jet head, for example,
As described in Patent Document 1, a pair of electrodes is provided via an air gap, and one electrode functions as a diaphragm, and ink is filled on the opposite side of the diaphragm from the opposite electrode. An ink chamber is formed, and by applying a voltage between the electrodes (between the diaphragm and the electrode), an electrostatic attraction acts between the electrodes to deform the electrode (the diaphragm). When the voltage is removed, the diaphragm becomes elastic. Some devices return to the original state by force and eject ink droplets using the force.
[0008]
Also,
Patent Document 2 describes that a head is formed by forming a minute gap between a diaphragm and an electrode by sacrifice layer etching and joining a liquid chamber substrate thereon.
It is listed. Also,
Japanese Patent Application Laid-Open Publication No. H11-163,086 discloses a single-beam or double-beam vibration plate that allows ink to flow into a gap, and enables low-voltage driving by filling the gap with high-dielectric-constant ink. Has been described.
[0009]
[Problems to be solved by the invention]
By the way, in an electrostatic ink jet head including an electrostatic actuator having a diaphragm and electrodes facing each other, the air gap between the electrodes must be extremely small in order to reduce the voltage.
[0010]
However, above
In the head described in Patent Literature 1, an air gap is created by forming a concave portion by etching and bonding to a diaphragm substrate by anodic bonding, and it is possible to form such a minute gap with high accuracy and little variation. It is very difficult and there is a problem that the yield does not increase.
[0011]
So, above
In the head described in Patent Literature 2, a gap formation method using sacrifice layer etching is used as a method for forming a gap with high accuracy. However, since holes for etching a sacrifice layer are formed on the surface of the diaphragm, the diaphragm is formed. The reliability of the device decreases. In addition, since the method of closing the etching hole with the insulating film after the sacrifice layer etching is used, it is necessary to form a thick insulating film for sealing the hole, the rigidity of the diaphragm increases, the driving voltage increases, In addition, there is a problem that the diaphragm rigidity is a factor of variation. In addition, there is unevenness on the surface of the actuator substrate due to the formation of the gap, high alignment accuracy is required when joining the liquid chamber substrates, the joining area is reduced, and work errors such as destruction due to contact at the time of joining are liable to occur. There is a problem that it is easy to cause a decrease in performance and a decrease in yield.
[0012]
Also, the above
In the head described in Patent Literature 3, a gap is formed by sacrificial layer etching. However, the diaphragm has a single-stick or double-stick structure, and the gap communicates with the liquid chamber. In this case, there is no need to form a hole for etching the sacrificial layer, and the ink can penetrate into the gap. Therefore, by using a high dielectric constant ink, the effective gap can be reduced and low voltage driving is possible. However, since a voltage is applied to the ink in the gap, there is a problem that the problem of aggregation of the ink components easily occurs, and high-speed driving cannot be performed due to the conductance of the ink in the gap.
[0013]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an electrostatic actuator that has a small characteristic variation and high reliability, and a highly reliable liquid droplet discharge characteristic with the use of the electrostatic actuator. Droplet ejection head and ink cartridge capable of obtaining the same, an inkjet recording apparatus capable of performing high-quality recording by including the droplet ejection head or the ink cartridge, a micropump and an optical device capable of obtaining high reliability with little variation in operation characteristics, It is an object of the present invention to provide a method for manufacturing a droplet discharge head that has a small variation in droplet discharge characteristics and high reliability.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, an electrostatic actuator according to the present invention includes a deformable diaphragm on a base substrate and electrodes facing each other with a predetermined gap therebetween. Is formed by sacrifice layer etching, and the surface of the actuator on the diaphragm side is substantially flat.
[0015]
Here, it is preferable that the step on the surface of the actuator on the diaphragm side does not exceed 0.5 μm. Preferably, the base substrate is formed from a silicon substrate. Further, it is preferable that a sacrifice layer remains between a plurality of gaps. In this case, when the remaining sacrifice layer is made of a conductive material, it is preferable that the sacrifice layer be connected to a reference potential.
[0016]
Further, it is preferable that the sacrificial layer is wholly or partially left on the electrode lead portion formed integrally with the electrode. Furthermore, it is preferable that adjacent electrodes are separated by a plurality of separation grooves. In this case, it is preferable that the separation grooves be buried with an insulating film.
[0017]
Further, the sacrificial layer is preferably such that a portion to be removed by etching and a remaining portion are separated by a single or a plurality of separation grooves. In this case, it is preferable that the separation grooves be buried with an insulating film.
[0018]
Further, the sacrificial layer removed by etching is preferably polysilicon or amorphous silicon, and the electrode is preferably formed of polysilicon, a compound silicide, a metal, or a high melting point metal, and at least a part of the diaphragm is provided. Is polysilicon, compound silicide, metal, high melting point metal, ITO film, Nesa film (SnO ₂ ) Or ZnO.
[0019]
The droplet discharge head according to the present invention includes an actuator substrate constituting an electrostatic actuator according to the present invention for pressurizing a liquid in a pressurized liquid chamber to which a nozzle that discharges a droplet communicates, and a pressurized liquid chamber. And a flow path forming member to be formed.
[0020]
Here, it is preferable that the flow path forming member seals the opening for removing the sacrificial layer formed on the actuator substrate constituting the electrostatic actuator.
[0021]
The ink cartridge according to the present invention integrates the droplet discharge head according to the present invention and an ink tank that supplies ink to the droplet discharge head.
[0022]
An ink jet recording apparatus according to the present invention is equipped with the droplet discharge head according to the present invention for discharging ink droplets or the ink cartridge according to the present invention.
[0023]
A micropump according to the present invention includes an actuator substrate that forms an electrostatic actuator according to the present invention that pressurizes a liquid in a flow path, and a flow path forming member that forms a flow path.
[0024]
An optical device according to the present invention includes an actuator substrate constituting an electrostatic actuator according to the present invention for deforming a mirror that reflects light.
[0025]
A method for manufacturing a droplet discharge head according to the present invention includes a step of separating an electrode member formed on a base substrate into a plurality of electrodes by a separation groove, a step of embedding the separation groove with an insulating film, and a step of flattening the insulating film; Forming a sacrificial layer thereon, forming a diaphragm member including a film having etching resistance on the sacrificial layer, and etching and removing the sacrificial layer after forming an opening in the diaphragm member. It is configured.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of an ink jet head according to a first embodiment of the droplet discharge head of the present invention, and is a partial cross-sectional view. FIG. 2 is a cross-sectional explanatory view of the same head along the transverse direction of the diaphragm, and FIG. 3 is a cross-sectional explanatory view of the same head along the longitudinal direction of the diaphragm.
[0027]
This inkjet head is of a side shooter type in which ink droplets are ejected from nozzle holes provided on the surface of a substrate, and has a laminated structure in which two first and second substrates 1 and 2 are overlapped and joined. By joining the first substrate 1 and the second substrate 2, the discharge chambers 6 in which a plurality of nozzle holes 4 for discharging ink droplets communicate with each other, and ink is supplied to each of the discharge chambers 6 via the fluid resistance portion 7. A flow path such as a common liquid chamber (common ink chamber) 8 is formed. Note that an edge shooter type in which ink droplets are ejected from a nozzle hole provided at an end of the substrate can also be used.
[0028]
The first substrate 1 is formed by joining a flow path forming member 12 that forms a flow path such as a discharge chamber 6 and a common liquid chamber 8 on an actuator substrate 11 that constitutes the electrostatic actuator according to the present invention.
[0029]
The actuator substrate 11 includes a deformable vibration plate 22 and an electrode 24 opposed to the vibration plate 22 with a gap 23 therebetween on a base substrate 21 made of a single crystal silicon substrate. By forming the base substrate 21 from a silicon substrate, a high-temperature process can be used and the process design can be facilitated, and a highly reliable head (actuator) can be manufactured at a low cost by selecting a film excellent in electrical and mechanical properties. it can.
[0030]
Here, the electrode 24 is formed on the insulating film 21a formed on the base substrate 25 and is separated by a separation groove 26 for each channel, and the separation groove 26 is formed on the surface of the electrode 24 (surface on the side of the diaphragm 22). The insulating film 27 is embedded. By separating the electrode 24 by the groove 26 and embedding the electrode 24 with the insulating film 27, it is possible to form the electrode 24 in a substantially flat state with few steps on the surface in a later step, and to facilitate the process design in the later step.
[0031]
As a material (electrode member) of the electrode 24, polysilicon or compound silicide can be used, and since these materials can be formed and processed with stable quality and can have a structure that can withstand a high-temperature process. In other processes, restrictions on the temperature are reduced, and for example, a highly reliable insulating film (HTO film) can be laminated as the insulating film 27, so that the process options can be widened and the cost can be reduced. And high reliability.
[0032]
In addition, a metal or a high melting point metal can be used as a material (electrode member) of the electrode 24, thereby greatly reducing the resistance, lowering the driving voltage, and stabilizing any material. Since film formation and processing can be performed with reduced quality, cost reduction and high reliability can be achieved.
[0033]
The gap 23 is formed by etching and removing a sacrificial layer formed between the diaphragm 22 and the electrode 24 as described later. At least a plurality of gaps 23, 23 among the sacrificial layers used for forming the gap are formed. The intervening sacrificial layer 28a is left to form a partition.
[0034]
As described above, by forming the gap 23 by the sacrifice layer etching, the gap interval (gap length) can be precisely defined by the thickness of the sacrifice layer. Can be prevented and the yield is improved. Further, since the sacrificial layer 28a is left as a gap space (gap spacer), the surface of the actuator substrate 11 can be made flatter without forming a gap step. The process design in the post-process such as the joining process of the road forming member 12 becomes easy, and the cost can be reduced and the reliability can be improved.
[0035]
Here, it is preferable to use polysilicon or amorphous silicon as the sacrificial layer. These materials can be removed by etching, and a silicon oxide film having high etching resistance can be formed above and below the sacrificial layer, so that a manufacturing process with less variation can be achieved. Becomes possible.
[0036]
The diaphragm 22 is composed of a laminated film in which an insulating film 22c having etching resistance, an electrode film 22a serving as a common electrode, and an insulating film 22b are sequentially laminated. Note that a part of the insulating film 22c also serves as a protective film for leaving the sacrificial layer 28 on the gap wall. The insulating film 22c on the wall surface of the sacrifice layer 28 is one in which a separation groove formed in the sacrifice layer 28 in the manufacturing process is buried. The diaphragm 22 has an opening 29 for etching the sacrificial layer in order to form the gap 23 by the sacrificial layer etching.
[0037]
As a material of the electrode film 22a constituting a part of the diaphragm 22, polysilicon or a compound silicide can be used, and these materials can be formed and processed with stable quality, and can be used in a high-temperature process. Since the structure can withstand, the restriction on the temperature in other processes is reduced, and for example, a highly reliable insulating film (HTO film) can be stacked as the insulating film 22c, and the process options can be widened. And cost reduction and high reliability can be achieved.
[0038]
In addition, a metal or a high melting point metal can be used as a material of the electrode film 22a constituting a part of the vibration plate 22, thereby significantly reducing resistance and driving voltage. Since any material can be formed and processed with stable quality, cost reduction and high reliability can be achieved.
[0039]
Alternatively, as a material of the electrode film 22a constituting a part of the diaphragm 22, an ITO film, a Nesa film (SnO ₂ ) Or ZnO, which makes it easier to inspect the inside of the gap 23 and detect abnormalities during the manufacturing process, so that the cost can be reduced and the reliability can be improved.
[0040]
Further, the electrode 24 is integrally formed with an electrode lead portion 24a and pulled out to form an electrode pad portion 31 serving as a connection portion with a connection means such as an FPC for connecting to a drive IC or the like.
[0041]
The actuator substrate 11 configured as described above is formed so that the surface on the diaphragm 22 side is substantially flat. Since the surface of the actuator substrate 11 on the vibration plate 22 side is formed substantially flat as described above, the formation of the ink-resistant liquid-contacting film and the joining and forming steps of the flow path forming member are facilitated, so that the characteristics are varied. It is possible to manufacture a highly reliable electrostatic actuator with low cost at low cost.
[0042]
In this case, it is preferable that the surface step of the actuator substrate 11 does not exceed at least 0.5 μm. Within this range, an ink-resistant liquid-contacting film having corrosion resistance to ink having a film thickness of about 1 μm, for example, can be uniformly formed on the liquid chamber side surface of the vibration plate 22 by a spin coating method. In addition, even in the joining step of the flow path forming member and the like, the joining can be performed with high reliability without being affected by the step, and a highly reliable head can be obtained at low cost.
[0043]
The flow path forming member 12 is formed by joining a substantially flat surface of the actuator substrate 11 on the side of the vibration plate 22 and removing a portion corresponding to the discharge chamber 6 by etching.
[0044]
As the second substrate 2 bonded to the upper surface of the flow path forming member 12 of the first substrate 1, a nickel substrate having a thickness of 50 μm is used, and nozzle holes are formed on the surface of the substrate 2 so as to communicate with the discharge chamber 6. 4, a groove 7 serving as a fluid resistance for communicating the common liquid chamber 8 with the discharge chamber 6 is provided, and an ink supply port 9 is provided so as to communicate with the common liquid chamber 8.
[0045]
The operation of the ink jet head thus configured will be described. When a pulse potential of 40 V is applied from the oscillation circuit (drive circuit) to the individual electrode 24 in a state where the ejection chamber 6 is filled with the ink, the surface of the individual electrode 24 is charged to a positive potential, and a static potential is formed between the individual electrode 24 and the diaphragm 22. The electric power acts, and the diaphragm 22 bends toward the individual electrode 24. As a result, the pressure in the discharge chamber 6 decreases, and ink flows from the common liquid chamber 8 into the discharge chamber 6 via the fluid resistance portion 7.
[0046]
Thereafter, when the pulse voltage to the individual electrode 24 is set to 0 V, the diaphragm 22 bent downward by the electrostatic force returns to its original state due to its own rigidity. As a result, the pressure in the discharge chamber 6 sharply increases, and the ink droplet 35 is discharged from the nozzle hole 4 toward the recording paper 36 as shown in FIG. By repeating this, ink droplets can be continuously ejected.
[0047]
Here, the force F acting between the diaphragm 22 as an electrode and the individual electrode 24 increases in inverse proportion to the square of the distance d between the electrodes as shown in the following equation (1). In order to drive at a low voltage, it is important to form the gap (gap length) between the individual electrode 24 and the gap 23 between the diaphragm 22 narrow.
[0048]
(Equation 1)

[0049]
In the equation (1), F is a force acting between electrodes, ε is a dielectric constant, S is an area of a surface facing the electrodes, d is a distance between the electrodes, and V is an applied voltage.
[0050]
Therefore, by forming the gap 23 by the sacrifice layer etching as described above, a minute gap can be formed with high accuracy.
[0051]
Next, a first embodiment of the method for manufacturing the ink jet head will be described with reference to FIGS. 4 and 5 are cross-sectional explanatory views for explaining the manufacturing method, and FIG. 6 is a plan explanatory view of the same.
Here, an actuator substrate is manufactured by depositing an electrode material, a sacrificial layer, and a diaphragm material on a base substrate.
[0052]
First, as shown in FIG. 4A, a thermal oxide film 45 serving as an insulating film is formed on a silicon substrate 41 having a plane orientation (100) to a thickness of about 1.0 μm by, for example, a wet oxidation method. Thereafter, a polysilicon 44 serving as an individual electrode is formed in a thickness of 0.4 μm on the thermal oxide film 45, and the polysilicon 44 is doped with phosphorus for lowering the resistance. Then, as shown in FIG. 6, after the electrode separation groove 46 is formed by the lithography method, a high-temperature oxide film (HTO film) 47 as an insulating film is formed to a thickness of 0.25 μm. At this time, the electrode isolation groove 46 is buried with the HTO film 47 and becomes flat including the surface of the polysilicon 44 which becomes an electrode. Note that an electrode pad 51 is also formed on the polysilicon 44 serving as an individual electrode, as shown in FIG.
[0053]
Next, as shown in FIG. 6B, a polysilicon 48 serving as a sacrificial layer is formed to a thickness of 0.5 μm on the HTO film 43, and then, as shown in FIG. Then, a high-temperature oxide film (HTO film) 42c as an insulating film is formed to a thickness of 0.1 μm. At this time, the width of the separation groove 50 is preferably set to a groove width embedded with a diaphragm material such as the HTO film 42c, and is preferably 2.0 μm or less depending on the thickness of the diaphragm material. Here, the width of the separation groove 50 is set to 0.5 μm, and the separation groove 50 is embedded with the HTO film 42c.
[0054]
As described above, the sacrifice layer 48 is separated by the groove 50 and is buried with the insulating film 42c, so that it can be formed in a substantially flat state with few steps on the surface in a later process, and the substantially flat surface of the actuator substrate can be formed. And the subsequent process design becomes easy.
[0055]
Further, as shown in FIG. 3C, a phosphorus-doped polysilicon 42a serving as a common electrode is formed to a thickness of 0.2 μm, and an oxide film 42b serving as a diaphragm protection film is formed to a thickness of 0.3 μm. Thereafter, in order to form the sacrifice layer removing hole 49 by litho etching in a region to be a liquid chamber spacing wall later, a pattern oversized from the sacrifice layer removing hole 49 is formed by litho etching, and the oxide film 42ba and the polysilicon 42a are formed. Etching is performed in order. Thereafter, oxidation is performed to form an oxide film 42a1 on the surface of the polysilicon 42a exposed on the side surface of the removal hole 49.
[0056]
Thereafter, as shown in FIGS. 5A and 6, the removal hole 49 is patterned by a litho-etching method, and the oxide film (HTO film) 42 c is removed by etching. ₆ The gap 43 is formed by removing the sacrifice layer 48 by isotropic dry etching using. It should be noted that wet etching using an alkali etching solution such as KOH or TMAH may be used, or XF ₂ Normal pressure dry etching using gas may be used.
[0057]
Here, since the sacrifice layer (polysilicon) 48 is surrounded by the oxide films 47 and 42c, the sacrifice layer 48 can be removed under the sacrifice layer etching condition having high selectivity to the oxide film, and the gap 23 can be precisely formed. Can be well formed. In addition, by leaving the sacrificial layer 48a between the gaps 23 separated by the separation groove 50 as a gap spacer, the substrate surface can be made substantially flat.
[0058]
Since the conductance of the etching gas (or liquid) introduction portion is determined by the size of the sacrificial layer removing hole 49, if the value is small, the etching rate is determined by the gas (or liquid) supply rate at the time of removing the sacrificial layer. Therefore, it is necessary to increase the conductance of the removal hole 49 so as to control the reaction. For this purpose, it is preferable that the cross-sectional area of the removal hole 49 be larger than the square of the gap length. Further, it is preferable to arrange the removal holes 49 at a pitch smaller than the short side length of the gap so that the sacrificial layer in the gap portion can be uniformly etched.
[0059]
Thereafter, as shown in FIG. 2B, the flow path forming member 12 having the liquid chamber (discharge chamber) 6 and the common liquid chamber 8 formed therein is formed on the actuator substrate 11 obtained as described above. Adhere with adhesive. At this time, the surface of the actuator substrate 11 is formed substantially flat, so that it can be easily bonded. Further, the gap 23 can be completely sealed by closing the sacrificial layer removing hole 49 with the flow path forming member 12.
[0060]
Although not shown in the figure, the nozzle plate 2 is finally bonded to the surface of the flow path forming member 12 to complete the electrostatic droplet discharge head.
[0061]
Here, polysilicon is used for the sacrificial layer 48, but other materials can be used for the sacrificial layer. When a silicon oxide film is used for the sacrificial layer, polysilicon is used as a protective film. After the sacrificial layer oxide film is removed by a wet etch method, an HF vapor method, a chemical dry etching method, or the like, an insulating layer is formed by oxidizing the polysilicon surface as a protective film.
[0062]
In addition, a resist is used for the sacrificial layer and O ₂ A method of removing with a plasma or a stripping solution, a method of removing with a organic material using a polymer material for a sacrificial layer, a method of removing with a chemical solution such as KOH using aluminum for a sacrificial layer, and a method of using TiN for a sacrificial layer and NH ₃ OH and H ₂ O ₂ A process similar to that described above can be assembled in various combinations, such as a method of removing with a chemical solution such as a mixed solution.
[0063]
Further, as described above, a compound silicide, which is a compound of metal and silicon, or a high melting point metal can be used as the electrode material, in addition to polysilicon. Furthermore, if a CVD oxide film is used for the insulating film and a low-temperature polysilicon is used for the polysilicon, a metal material such as aluminum, an ITO film, and a Nesa film (SnO film) can be used. ₂ ) Can be used as the electrode material.
[0064]
Further, in the case where an ink-wet-resistant film having corrosion resistance to ink is formed on the diaphragm surface as a protective film for alkaline ink having a high pH value, the surface of the actuator substrate 11 is substantially flat. Thus, a more uniform liquid contact film can be formed.
[0065]
Further, since the surface of the actuator substrate 11 is substantially flat, a liquid chamber (ejection chamber) can be formed of photosensitive polyimide or DFR applied by spin coating.
[0066]
As described above, in the droplet discharge head including the electrostatic actuator manufactured according to the above manufacturing flow, since the gap interval is defined by the thickness of the sacrificial layer, the gap can be formed with high accuracy and with little variation. Discharge characteristics), the reliability is improved, and a high-quality image can be recorded. In addition, since no direct bonding or anodic bonding is required, a droplet discharge head can be constituted by two substrates, cost can be reduced, and most of the heads can be manufactured by a semiconductor process. Obtainable.
[0067]
Further, by using a silicon substrate as the base substrate of the actuator substrate 11, the high-temperature process as described above can be used, and the process design becomes easy. The high-temperature process refers to processes such as thermal oxidation, thermal CVD for forming HTO or doped polysilicon, and LP-CVD for forming a high-quality nitride film. In addition, it is possible to select a film excellent in electrical and mechanical properties and to obtain a highly reliable droplet discharge head at low cost.
[0068]
Next, an electrostatic actuator constituting a droplet discharge head according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a cross-sectional explanatory view of the same actuator along the transverse direction of the diaphragm, FIG. 8 is a plan explanatory view of one channel of the same actuator, and FIG. 7A is a description for explaining an electrode separation groove. FIG. 3B is an explanatory diagram for explaining a sacrifice layer separation groove. Also, here, the description will be made using the reference numerals used in the description of FIGS. 4 to 6 described above.
[0069]
In this actuator, as shown in FIGS. 7 and 8A, two separation grooves 46, 46 are formed between the electrodes 44, 44. Therefore, the electrode material (electrode member) 44a remains between the separation grooves 46. As shown in FIG. 8A, the two separation grooves 46 are bridged by bridge portions 46a provided at a plurality of locations.
[0070]
As described above, by using a plurality of separation grooves between the electrodes, even when the separation grooves are narrowed, the possibility that the electrodes are short-circuited due to a patterning defect caused by a foreign substance or a pattern defect can be reduced, and the yield can be reduced. An improved, low cost and highly reliable head can be obtained. Further, by providing a bridging portion for bridging a plurality of separation grooves, that is, by further dividing the electrode material remaining between the separation grooves, the possibility of short-circuiting between the electrodes can be reduced more reliably.
[0071]
Also, in this actuator, as shown in FIGS. 7 and 8B, three separation grooves 50 for separating the sacrificial layer 48 are formed between the gaps 43. Therefore, sacrifice layers (sacrifice layer materials) 48a, 46a remain between the separation grooves 50, 50, 50. As shown in FIG. 8B, the three separation grooves 50, 50, 50 are bridged by bridge portions 50a provided at a plurality of locations.
[0072]
As described above, by setting the number of the separation grooves of the sacrificial layer to three or more, the possibility of communication between the gaps due to the patterning failure caused by the foreign matter or the pattern defect can be reduced, and the yield can be improved, and the yield can be improved. A highly reliable head can be obtained at a low cost. Further, by providing a bridging portion bridging between three or more separation grooves, that is, by further dividing the sacrificial layer remaining between the separation grooves, it is possible to more reliably reduce the possibility that the gaps communicate with each other. it can.
[0073]
Next, an electrostatic actuator constituting a droplet discharge head according to a third embodiment of the present invention will be described with reference to FIG.
In this embodiment, a sacrifice layer 28b is left on the lead portion 24a of the electrode 24. This sacrifice layer 28b is integrated with the sacrifice layer 28a (see FIG. 2) remaining between the gaps 23. . Thus, the surface of the actuator substrate 11 can be made more flat by leaving the sacrificial layer also on the lead portion 24a of the electrode 24.
[0074]
Further, in this embodiment, as the sacrificial layers 28a and 28b, for example, polysilicon is doped with an impurity such as P or As to form a conductive material, and the sacrificial layers 28a and 28b are sacrificed between the respective channels by using the connection member 61 penetrating the diaphragm 22. The layer 28b is electrically connected, and the sacrificial layers 28a and 28b are connected to a reference potential. As described above, by electrically connecting at least the sacrificial layer 28a remaining between the gaps 23, 23 to the reference potential, the capacity between the gaps can be reduced, and stable high-speed driving of the actuator becomes possible.
[0075]
In this case, the reference potential varies depending on the driving method such as a ground potential, a diaphragm potential, an electrode potential, a potential intermediate between the diaphragm and the electrode potential, and the like. preferable.
[0076]
As shown in FIG. 10, the sacrificial layer 28b may partially remain on the lead portion 24a of the electrode 24. With this configuration, the capacity between the actuators can be reduced, the actuator can be driven at a high speed, and the strength of the electrode lead portion 24a can be maintained. In this case, as described above, by connecting the sacrificial layer 28a (see FIG. 2) remaining between the gaps 23, 23 to the reference potential, the capacity between the actuators can be further reduced, and the actuator can be driven at high speed. It becomes possible.
[0077]
Next, an ink cartridge integrated head of a droplet discharge head according to the present invention will be described with reference to FIG.
The ink cartridge integrated type head 100 is obtained by integrating the ink jet head 102 having any of the above-described embodiments having the nozzle holes 101 and the like, and the ink tank 103 that supplies ink to the ink jet head 101. .
[0078]
As described above, by integrating the ink tank that supplies ink to the droplet discharge head according to the present invention, there is little variation in droplet discharge characteristics, and an ink cartridge (ink tank) that integrates a highly reliable droplet discharge head. (Integrated head) can be obtained at low cost.
[0079]
Next, an example of a mechanism of an ink jet recording apparatus equipped with an ink jet head, which is a droplet discharge head according to the present invention, will be described with reference to FIGS. FIG. 12 is a perspective view of the recording apparatus, and FIG. 13 is a side view of a mechanism of the recording apparatus.
[0080]
The inkjet recording apparatus includes a carriage movable in the main scanning direction inside the recording apparatus main body 111, a recording head including the inkjet head according to the present invention mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. A paper cassette (or a paper tray) 114 capable of loading a large number of sheets 113 from the front side is detachably attached to a lower portion of the apparatus main body 111. The manual feed tray 115 for manually feeding the paper 113 can be opened, and the paper 113 fed from the paper feed cassette 114 or the manual feed tray 115 is taken in. After the image is recorded, the sheet is discharged to a sheet discharge tray 116 mounted on the rear side.
[0081]
The printing mechanism 112 holds the carriage 123 slidably in the main scanning direction (the direction perpendicular to the paper of FIG. 12) by a main guide rod 121 and a sub guide rod 122, which are guide members that are laterally mounted on left and right side plates (not shown). On the carriage 123, a head 124 composed of an inkjet head, which is a droplet discharge head according to the present invention, which discharges ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). Are arranged in a direction intersecting the main scanning direction with a plurality of ink ejection ports, and are mounted with the ink droplet ejection direction facing downward. Each ink cartridge 125 for supplying each color ink to the head 124 is exchangeably mounted on the carriage 123. It should be noted that the ink cartridge according to the present invention may be mounted.
[0082]
The ink cartridge 125 has an upper air port that communicates with the atmosphere, a lower supply port for supplying ink to the inkjet head, and a porous body filled with ink inside. Maintains the ink supplied to the inkjet head at a slight negative pressure.
[0083]
Further, although the heads 124 of each color are used as the recording heads here, a single head having nozzles for ejecting ink droplets of each color may be used.
[0084]
Here, the carriage 123 is slidably fitted on the main guide rod 121 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the front guide rod 122 on the front side (upstream side in the paper conveyance direction). are doing. In order to move and scan the carriage 123 in the main scanning direction, a timing belt 130 is stretched between a drive pulley 128 and a driven pulley 129 which are driven to rotate by a main scanning motor 127. , And the carriage 123 is reciprocally driven by forward and reverse rotation of the main scanning motor 127.
[0085]
On the other hand, in order to convey the paper 113 set in the paper feed cassette 114 to the lower side of the head 124, the paper 113 is guided by a paper feed roller 131 and a friction pad 132 for separating and feeding the paper 113 from the paper feed cassette 114. A guide member 133, a transport roller 134 that transports the fed paper 113 in a reversed state, a transport roller 135 pressed against the peripheral surface of the transport roller 134, and a leading end that defines an angle at which the paper 113 is fed from the transport roller 134. A roller 136 is provided. The transport roller 134 is driven to rotate by a sub-scanning motor 137 via a gear train.
[0086]
Further, an image receiving member 139 is provided as a paper guide member for guiding the paper 113 sent from the transport roller 134 below the recording head 124 in accordance with the movement range of the carriage 123 in the main scanning direction. On the downstream side of the printing receiving member 139 in the paper transport direction, there are provided a transport roller 141 and a spur 142 which are driven to rotate to transport the paper 113 in the paper discharge direction. Rollers 143 and spurs 144 and guide members 145 and 146 forming a paper discharge path are provided.
[0087]
At the time of recording, the recording head 124 is driven in accordance with an image signal while moving the carriage 123, thereby ejecting ink to the stopped paper 113 to record one line, and after transporting the paper 113 by a predetermined amount, Record the line. Upon receiving a recording end signal or a signal indicating that the rear end of the sheet 113 has reached the recording area, the recording operation is terminated and the sheet 113 is discharged.
[0088]
In addition, a recovery device 147 for recovering the ejection failure of the head 124 is disposed at a position outside the recording area on the right end side in the moving direction of the carriage 123. The recovery device 147 has a cap unit, a suction unit, and a cleaning unit. The carriage 123 is moved to the recovery device 147 side during printing standby, the head 124 is capped by the capping means, and the ejection port is kept in a wet state, thereby preventing ejection failure due to ink drying. In addition, by discharging ink that is not related to printing during printing or the like, the ink viscosity of all the discharge ports is kept constant, and stable discharge performance is maintained.
[0089]
In the event of a discharge failure, for example, the discharge port (nozzle) of the head 124 is sealed by a capping unit, and air bubbles and the like are sucked out of the discharge port by a suction unit through a tube, and ink or dust adhered to the discharge port surface. Is removed by the cleaning means, and the ejection failure is recovered. The sucked ink is discharged to a waste ink reservoir (not shown) provided at a lower portion of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir.
[0090]
As described above, since the inkjet recording apparatus is equipped with the inkjet head, which is the droplet ejection head according to the present invention, there is little variation in the ejection characteristics of ink droplets, and a recording apparatus capable of recording an image with high image quality is provided. can get.
[0091]
Next, a micropump as a microdevice provided with the electrostatic actuator according to the present invention will be described with reference to FIG. FIG. 3 is an explanatory cross-sectional view of a main part of the micropump.
This micropump has a flow path substrate 201 and an actuator substrate 202 constituting an electrostatic actuator according to the present invention. The flow path substrate 201 has a flow path 203 through which a fluid flows. The actuator substrate 202 includes a deformable diaphragm (movable plate) 222 that is provided on the base substrate 221 and forms the wall surface of the flow path 201, and a predetermined gap 223 is placed on the deformable portion 222 a of the diaphragm 222. The electrode 224 includes an opposing electrode 224 and has a substantially flat surface. Although a detailed description of the actuator substrate 202 is omitted, it is the same as that described in the embodiment of the inkjet head.
[0092]
The principle of operation of this micropump will be described. As in the case of the above-described ink jet head, by selectively applying a pulse potential to the electrode 224, an electrostatic attraction force is generated between the electrode 224 and the vibration plate 222. The deformable portion 222a of the plate 222 is deformed toward the electrode 224. Here, by sequentially driving the deformable portion 222a of the diaphragm 222 from the right side in the drawing, the fluid in the flow path 201 flows in the direction of the arrow, and the fluid can be transported.
[0093]
In this case, by providing the electrostatic actuator according to the present invention, it is possible to obtain a small-sized and low-power-consumption micropump capable of performing stable liquid transport with little characteristic variation. Although an example in which the diaphragm has a plurality of deformable portions is shown here, one deformable portion may be provided. In addition, one or more valves, for example, a check valve or the like can be provided between the deformable portions in order to increase the transportation efficiency.
[0094]
Next, an example of an optical device including the electrostatic actuator according to the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of the device.
This optical device has an actuator substrate 302 including a mirror 301 whose surface can reflect light and is deformable. It is preferable to form a dielectric multilayer film or a metal film on the surface of the mirror 301 to increase the reflectance.
[0095]
The actuator substrate 302 includes a deformable mirror 301 (corresponding to a diaphragm of the head) provided on a base substrate 321, and an electrode 324 that faces the deformable portion 301 of the mirror 301 via a predetermined gap 323. And the surface of the mirror 301 is formed substantially flat. The actuator substrate 302 also differs from that described in the embodiment of the ink jet head only in that the diaphragm has a mirror surface, and a detailed description thereof will be omitted.
[0096]
The principle of this optical device will be described. As in the case of the above-described ink jet head, by selectively applying a pulse potential to the electrode 324, the electrostatic force is applied between the deformable portion 301a of the mirror 301 facing the electrode 324. Since the attraction force is generated, the deformable portion 301 of the mirror 301 is deformed into a concave shape to become a concave mirror. Therefore, when the light from the light source 310 irradiates the mirror 301 via the lens 311, when the mirror 301 is not driven, the light is reflected at the same angle as the incident angle, but when the mirror 301 is driven, the driven deformation is caused. Since the possible portion 301 becomes a concave mirror, the reflected light becomes divergent light. Thereby, an optical modulation device can be realized.
[0097]
Further, by providing the electrostatic actuator according to the present invention, it is possible to obtain a small-sized and low-power-consumption optical device with small characteristic variations.
[0098]
Therefore, an example in which this optical device is applied will be described with reference to FIG. In this example, the above-described optical devices are two-dimensionally arranged, and the deformable portions 301a of each mirror 301 are independently driven. Although a 4 × 4 arrangement is shown here, more arrangements are possible.
[0099]
Therefore, similarly to FIG. 15 described above, the light from the light source 310 is applied to the mirror 301 via the lens 311, and the light that enters the place where the mirror 301 is not driven enters the projection lens 312. On the other hand, the portion where the deformable portion 301a of the mirror 301 is deformed by applying a voltage to the electrode 324 becomes a concave mirror, so that light diverges and hardly enters the projection lens 312. The light incident on the projection lens 312 is projected on a screen (not shown) or the like, and an image can be displayed on the screen.
[0100]
In the above embodiment, an example in which the droplet discharge head is applied to an inkjet head has been described. However, as a droplet discharge head other than the inkjet head, for example, a droplet discharge head that discharges a liquid resist as a droplet, a DNA The present invention can be applied to other droplet discharge heads such as a droplet discharge head that discharges the sample as droplets. In addition to the micropump and the optical device (optical modulation device), the electrostatic actuator is applied to a microswitch (microrelay), a multi-optical lens actuator (optical switch), a micro flowmeter, a pressure sensor, and the like. be able to.
[0101]
【The invention's effect】
As described above, according to the electrostatic actuator of the present invention, the diaphragm includes a deformable diaphragm on the base substrate and electrodes facing each other with a predetermined gap therebetween. Is formed by etching the sacrifice layer and the surface of the actuator on the diaphragm side is substantially flat, so that there is little variation in characteristics, cost can be reduced, and reliability can be improved.
[0102]
According to the droplet discharge head according to the present invention, an actuator substrate constituting an electrostatic actuator according to the present invention for pressurizing a liquid in a pressurized liquid chamber to which a nozzle for discharging a droplet communicates, and a pressurized liquid Since the configuration includes the flow path forming member that forms the chamber, the variation in the droplet discharge characteristics is small, the cost can be reduced, and the reliability is improved.
[0103]
According to the ink cartridge of the present invention, since the droplet discharge head according to the present invention and the ink tank for supplying ink to the droplet discharge head are integrated, variation in droplet discharge characteristics is small, and cost can be reduced. , Reliability is improved.
[0104]
According to the inkjet recording apparatus of the present invention, since the droplet discharge head of the present invention for discharging ink droplets or the ink cartridge of the present invention is mounted, high-quality recording can be performed.
[0105]
According to the micropump according to the present invention, since the micropump includes the actuator substrate that forms the electrostatic actuator according to the present invention that pressurizes the liquid in the flow path and the flow path forming member that forms the flow path, the micropump is small and low-priced. A micro pump with low power consumption is obtained.
[0106]
According to the optical device according to the present invention, since the actuator device constituting the electrostatic actuator according to the present invention for deforming the mirror that reflects light is provided, an optical device with small size and low power consumption can be obtained. .
[0107]
According to the method of manufacturing a droplet discharge head according to the present invention, a step of separating an electrode member formed on a base substrate into a plurality of electrodes by a separation groove, and a step of burying the separation groove with an insulating film and planarizing the separation groove; A step of forming a sacrificial layer on the insulating film, a step of forming a diaphragm member including a film having etching resistance on the sacrificial layer, and a step of etching and removing the sacrificial layer after forming an opening in the diaphragm member. , It is possible to easily obtain a head in which the surface of the actuator on the diaphragm side is substantially flat.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an inkjet head according to a first embodiment of a droplet discharge head of the present invention.
FIG. 2 is an explanatory cross-sectional view of the head taken along a lateral direction of a diaphragm.
FIG. 3 is an explanatory cross-sectional view of the head along the longitudinal direction of the diaphragm.
FIG. 4 is a cross-sectional explanatory view for describing an embodiment of a method of manufacturing an ink-jet head which is a droplet discharge head according to the present invention.
FIG. 5 is an explanatory sectional view illustrating a step following FIG. 4;
FIG. 6 is an explanatory plan view for explaining the same step;
FIG. 7 is an explanatory sectional view of an electrostatic actuator constituting a second embodiment of the droplet discharge head according to the present invention.
FIG. 8 is an explanatory plan view of the actuator.
FIG. 9 is an explanatory cross-sectional view taken along a longitudinal direction of a diaphragm for explaining an ink jet head according to a third embodiment of the droplet discharge head according to the present invention.
FIG. 10 is a sectional explanatory view for explaining another example of the embodiment;
FIG. 11 is an explanatory perspective view for explaining an ink cartridge according to the present invention.
FIG. 12 is an explanatory perspective view illustrating an example of an ink jet recording apparatus according to the present invention.
FIG. 13 is an explanatory diagram of a mechanism section of the recording apparatus.
FIG. 14 is an explanatory diagram illustrating an example of a micropump according to the present invention.
FIG. 15 is an explanatory diagram illustrating an example of the optical device according to the present invention.
FIG. 16 is an explanatory perspective view illustrating an example of a light modulation device using the optical device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 1st board | substrate, 2 ... 2nd board | substrate (nozzle board), 4 ... nozzle hole, 6 ... discharge chamber, 7 ... fluid resistance part, 8 ... common liquid chamber, 11 ... actuator board | substrate, 12 ... flow path forming member, 21: base substrate, 22: diaphragm, 23: gap, 24: electrode, 100: ink cartridge, 124: recording head, 201: flow path substrate, 203: flow path, 202: actuator substrate, 222a: deformable part, 246: electrode, 301: mirror, 301a: deformable portion, 302: actuator substrate, 324: electrode.

Claims (24)

An electrostatic actuator that includes a deformable diaphragm on a base substrate and electrodes facing the diaphragm with a predetermined gap therebetween, and deforms the diaphragm with electrostatic force. In the electrostatic actuator, a gap between the diaphragm and the electrode is provided. Is formed by sacrificial layer etching, and the surface of the actuator on the side of the diaphragm is substantially flat. 2. The electrostatic actuator according to claim 1, wherein a step on a surface of the actuator on the diaphragm side does not exceed 0.5 μm. 3. The electrostatic actuator according to claim 1, wherein the base substrate is formed from a silicon substrate. 4. The electrostatic actuator according to claim 1, wherein the sacrificial layer remains between a plurality of gaps. 5. 5. The electrostatic actuator according to claim 4, wherein the remaining sacrificial layer is made of a conductive material, and the sacrificial layer is connected to a reference potential. The electrostatic actuator according to any one of claims 1 to 5, wherein the sacrificial layer is wholly or partially left on an electrode lead portion formed integrally with the electrode. Type actuator. 7. The electrostatic actuator according to claim 1, wherein the adjacent electrodes are separated by a plurality of separation grooves. The electrostatic actuator according to claim 7, wherein the separation groove is buried with an insulating film. 9. The electrostatic actuator according to claim 1, wherein a portion of the sacrificial layer removed by etching and a remaining portion are separated by a single or a plurality of separation grooves. Electric actuator. The electrostatic actuator according to claim 9, wherein the separation groove is buried with an insulating film. 11. The electrostatic actuator according to claim 1, wherein the sacrificial layer removed by etching is polysilicon or amorphous silicon. 12. The electrostatic actuator according to claim 1, wherein the electrode is formed of polysilicon or a compound silicide. The electrostatic actuator according to claim 1, wherein the electrode is formed of a metal or a high-melting metal. 14. The electrostatic actuator according to claim 1, wherein at least a part of the diaphragm is formed of polysilicon or compound silicide. 14. The electrostatic actuator according to claim 1, wherein at least a part of the vibration plate is formed of a metal or a high melting point metal. 14. The electrostatic actuator according to claim 1, wherein at least a part of the vibration plate is formed of an ITO film, a Nesa film (SnO ₂ ), or ZnO. . 17. The electrostatic discharge device according to claim 1, wherein a liquid in a pressurized liquid chamber to which a nozzle for discharging the liquid droplet communicates is pressurized by an electrostatic actuator to discharge the liquid droplet. A droplet discharge head comprising: an actuator substrate forming an actuator; and a flow path forming member forming the pressurized liquid chamber. 18. The droplet discharge head according to claim 17, wherein the flow path forming member seals an opening for removing the sacrificial layer formed on an actuator substrate constituting the electrostatic actuator. Characteristic droplet discharge head. 19. A droplet discharge head according to claim 17 or claim 18, wherein the droplet discharge head is an ink cartridge in which a droplet discharge head that discharges ink droplets and an ink tank that supplies ink to the droplet discharge head are integrated. An ink cartridge, characterized in that: 19. An ink jet recording apparatus equipped with an ink jet head for discharging ink droplets, wherein the ink jet head is the liquid drop discharging head according to claim 17 or 18. 20. An ink jet recording apparatus equipped with an ink cartridge integrating an ink jet head for discharging ink droplets and an ink tank for supplying ink to the ink jet head, wherein the ink cartridge is the ink cartridge according to claim 19. Inkjet recording device. 17. A micropump for transporting said liquid by pressurizing a liquid in a flow path by an electrostatic actuator and a flow forming said flow path and an actuator substrate constituting said electrostatic actuator according to claim 1. A micropump comprising a path forming member. An optical device for changing a light reflection direction by deforming a mirror that reflects light with an electrostatic actuator, comprising an actuator substrate constituting the electrostatic actuator according to any one of claims 1 to 16. An optical device, comprising: The method for manufacturing a droplet discharge head according to claim 17, wherein the electrode member formed on the base substrate is separated into a plurality of electrodes by a separation groove, and the separation groove is embedded with an insulating film. Flattening, forming a sacrificial layer on the insulating film, forming a diaphragm member including a film having etching resistance on the sacrificial layer, and forming an opening in the diaphragm member And removing the sacrificial layer by etching.

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