JP2004202296A - Liquid drop spray manufacturing apparatus and substrate formed by the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high quality pattern wiring board and a device substrate. <P>SOLUTION: A liquid drop spray apparatus is for forming a pattern wiring or a device by spraying a plurality of the liquid drops of a fine particle-containing solution by a spray head 11 having 20 μm diameter discharge port to be applied on a substrate 14 to form a pattern on an electric conduction region on the substrate 14, volatilizing a volatile component in the liquid drop pattern after being applied to leave solid matter on the substrate and the electric conduction region. In such a case, when the size of the fine particle is expressed by Dp and the diameter of a discharge port is expressed by Do, the relation of Dp to Do is controlled to be 0.0001≤Dp/Do≤0.01. In the spray head 11, the liquid drop is jetted by the growth action force of film boiling bubbles produced for a moment in the solution and the shape of the liquid in the flying of the liquid drop is made narrow long columnar to have a length 5 times of the diameter and the relative speed of the board 14 to the spray head 11 is controlled to be ≤1/3 of the jetting speed of the solution. Further, the narrow long columnar liquid in the flying is flied at a high speed to accompany a plurality of fine drops in the back side. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００７５】
【表２】

【００７６】
【表３】

【００７７】
【表４】

【００７８】
以上の結果より、吐出口径がΦ５μｍ〜Φ２０μｍの噴射ヘッドを用いた場合、Ａｇ微粒子径Ｄｐと吐出口径Ｄｏとは、Ｄｐ／Ｄｏ≦０.０１の関係を満足するようにすれば目詰まりのない安定した液滴噴射が得られることがわかる。なお、Ｄｐ／Ｄｏの下限値であるが、このように大変微細な微粒子を安定して、溶液中に分散することを考えると、Ａｇ微粒子径Ｄｐが０.０００３μｍ以下は困難である。また、吐出口径がΦ２０μｍ以下の噴射ヘッド全てに安定して液滴噴射させられるようにするには、余裕をみてＤｐ／Ｄｏの下限値を０.０００１にすればよい。すなわち、Ａｇ微粒子径Ｄｐと吐出口径Ｄｏとは、０.０００１≦Ｄｐ／Ｄｏ≦０.０１の関係を満足するようにすれば、吐出口径がΦ２０μｍ以下の噴射ヘッドを使用した液滴噴射によるパターン形成、あるいはデバイス形成を行うことができる安定した分散液を製造でき、吐出口（ノズル）の目詰まりも生じないようにすることができることがわかる。
【００７９】
なお、この実験では、丸形状の吐出口（ノズル）を使用したが、他の形状の場合は、その面積比較をすればよく、たとえば１８μｍ×１８μｍの矩形吐出口の場合は、本発明の丸形状のΦ２０μｍノズルとほぼ同等である。言い換えるならば、本発明は面積がほぼ３００μｍ²以下のノズルを使用した噴射ヘッド、またその下限値はほぼ２０μｍ²のノズル（吐出口径がΦ５μｍ）で、このような溶液を噴射してパターン形成、あるいはデバイス形成を行う場合に適用されるものである。
【００８０】
また、実験はピエゾ素子を液滴吐出の原動力とした噴射ヘッドを使用したが、この微粒子含有溶液を微小吐出口から噴射するという原理そのものに起因する目詰まりの課題は、後述する溶液中に瞬時に発生させた膜沸騰気泡の成長作用力を利用して微粒子含有溶液を微小吐出口から噴射するという原理にもとづく噴射ヘッドにも共通の課題であり、膜沸騰気泡利用の噴射ヘッドにも上記結果はそのまま適用することができる。
【００８１】
また、サーマルヘッド等を用いて膜沸騰気泡を発生させる方式はその構造上、発熱体部や、吐出口部の高密度、高集積配列が可能で、６００ｄｐｉ〜１２００ｄｐｉあるいはそれ以上の配列密度で、かつ吐出口（ノズル）数も５００〜１００００個というものが容易に実現でき、生産効率の高い製造装置に適している。
【００８２】
次に、本発明の他の特徴について説明する。前述のように本発明は微粒子含有溶液が微小な吐出口から目詰まりを起こすことなく安定した液滴噴射するようにしたものであるが、ここでは溶液噴射後に基板上に溶液が付着し、良好なパターン、あるいはデバイスを形成するにはどのようにしたらよいのかを検討した結果を示す。
【００８３】
前述のように、本発明では、吐出ヘッドユニット１１は基板１４に対して一定の距離を保ちながらパターン、あるいは機能デバイス群の形成面に対して平行にＸ、Ｙ方向の相対移動を行いつつ、パターン、あるいは機能デバイス群を形成する。すなわち、基板１４に対して、吐出ヘッドユニット１１が基板面に対して平行移動する、もしくは吐出ヘッドユニット１１に対して基板１４が平行移動する。
【００８４】
その際、パターン、あるいは機能デバイス群を形成するための微粒子含有溶液の噴射を行う毎に相対移動を止めて噴射を行うと高精度なパターン、あるいは機能デバイス群を形成することが可能である。しかし生産性が著しく低下するので、その相対移動を止めることなく、順次溶液の噴射を行うようにしている。その場合、その相対移動速度（例えば図２のキャリッジのＸ方向移動速度）は、単に生産性向上だけで決定されるべきではなく、高精度なパターン、あるいは機能デバイス群を形成するという観点からも検討されなければならない。
【００８５】
図１１は、本発明が好適に使用される膜沸騰気泡の成長作用力を利用して微粒子含有溶液を微小吐出口から噴射させた場合の噴射、飛翔時の溶液の形状を示したものである。図１２、図１３は、ピエゾ素子を液滴吐出の原動力とし、機械的作用力で噴射させた場合の噴射、飛翔時の溶液の形状を示したものである。
【００８６】
図１１と図１２および図１３の違いは、図１１の場合が、溶液の一部を瞬時（数μｓの間）に３００〜４００℃に加熱させ、膜沸騰気泡を発生させ、その気泡の瞬時（数μｓの間）の成長、圧力上昇（作用力）を利用して溶液を噴射するために、ピエゾ素子を液滴吐出の原動力とし、機械的作用力で噴射させた場合よりも噴射圧力が高く、噴射速度も速いという点である。その結果、図１１に示すように、飛翔時に、溶液の飛翔形状が飛翔方向に細長柱状に伸び、後方に複数の微小な滴（サテライト微小滴８１）を伴って高速で飛翔するという特徴を持っている。
【００８７】
たとえば、溶液飛翔時の形状は、通常安定した膜沸騰気泡を発生させて飛翔させた場合、飛翔方向に伸びた細長柱状の長さｌは、その直径ｄの５倍以上の長さとなり、またその速度は、ほぼ５ｍ／ｓ〜２０ｍ／ｓとなって飛翔する。
その結果、噴射が安定し噴射された溶液の基板上への着弾精度が高いという利点があるが、一方で、噴射ヘッドと基板の相対移動速度を適切に選ばないと、飛翔方向に細長柱状に伸びた後方部の溶液や、後方に連なった複数の微小な滴（サテライト微小滴８１）が、良好な丸いドット形成を妨げることもなる。
【００８８】
本発明では、この点に関して鋭意検討した結果、このような微粒子含有溶液の噴射を行う場合、その噴射速度と前記相対移動速度との間の関係を最適化することが必要であることに気がついた。ところで、このように吐出ヘッドユニット１１を基板１４に対して一定の距離を保ちながらＸ、Ｙ方向の相対移動を行いつつ、微粒子含有溶液の噴射を行い、パターン、あるいは機能デバイス群を形成する場合には、溶液は前記相対速度と噴射速度の合成ベクトルの速度で基板１４上に付着、形成される。そしてその位置精度については、基板１４と吐出ヘッドユニット１１の溶液噴射口面の距離と、前記合成ベクトルの速度を考慮し、噴射のタイミングを適宜選ぶことにより、その狙いの位置に溶液を付着させることができる。
【００８９】
しかしながら、たとえ狙いの位置に付着させることができたとしても、もし、前記相対速度が速すぎる場合には、その相対速度に引きずられて付着溶液が基板１４上で流れ、良好な丸いドット形状とならず、良好なパターン、あるいは機能デバイス群を形成できなくなる。また、後方に連なった複数の微小な滴（サテライト微小滴）が、本来付着すべき位置から外れた位置に、ランダムに散らばった状態で付着し、良好な丸いドット形成の妨げ、機能デバイス性能の低下を引き起こす場合がある。本発明はこの点について検討したものである。
【００９０】
以下に、検討結果の１例を示す。この例は、図２のような装置を用い、キャリッジ１２のＸ方向移動速度、ならびに吐出ヘッドユニット１１の噴射速度を変えて、基板１４上で良好な溶液付着ができ、良好なパターン形成ができるかどうか調べたものである。
【００９１】
図１４にテストに使用したパターンの例を示す。ここでは、Ａｇ微粒子含有溶液を噴射させ、２列の近接した素子電極間（ＩＴＯ透明電極８２間）を、前記溶液によるドットパターン８３をつなぎ合わせた配線パターンを形成し、そのパターンの形成状況を評価したものである。評価は、形成後のパターンを顕微鏡下で観察し、良／不良（○／×）を判断した。図１４（Ａ）は良（○）であり、図１４（Ｂ）のように、個々のドットパターン８３が良好な丸い形状にならず、長円形になったり、基板上における着弾位置も本来の狙いの位置から外れたりして、隣のドットパターンと接触したりするようなものは不良（×）である。さらに、サテライト微小滴に起因する微小滴８４が散在しているようなものも不良（×）とした。
【００９２】
このような形状の評価とあわせて、上下のＩＴＯ透明電極８２間の抵抗値を測定し、ドット位置精度不良による断線あるいは隣（左右）のドットとの接触による抵抗値変動などを評価した（○：狙い通りの抵抗値、×：狙いから外れた抵抗値）。
【００９３】
実験条件の詳細を以下に示す。使用した基板はＩＴＯ透明電極８２付きガラス基板であり、前述のＡｇ微粒子含有溶液（ここでは、微粒子径が０.０１μｍのものを使用）を図７に示した噴射ヘッド（ただし、Φ５μｍのノズルを設けたＮｉエレクトロフォーミング形成のマルチノズルプレートを別途設けたもの）と組み合わせて、図１４のようなパターンを形成した。なお、図１４は簡略化のため、１対のＩＴＯ透明電極８２間を４ドットで埋めるように形成した図を示しているが、実際には、縦方向に１列で、約Φ８μｍのドットを約４μｍピッチで約１０００個打ち込み、上下のＩＴＯ透明電極８２間（電極間距離４ｍｍ）をつないでいる。また隣に中心間距離を１２μｍとして、同様のＩＴＯ透明電極８２およびＩＴＯ透明電極８２間をつなぐ同様のパターンを形成している。
【００９４】
使用した噴射ヘッドは、前述のような噴射ヘッド（図７は、簡略化した４個のノズルを示している）であるが、ノズル（吐出口）数を６４個としている。また、その配列密度が４００ｄｐｉのものである。発熱体サイズは１０μｍ×４０μｍであり、その抵抗値は１０２Ωである。ヘッドの駆動電圧は１０〜１１Ｖとして噴射速度を変え、パルス幅は２μｓ、駆動周波数は１４ｋＨｚとした。
【００９５】
このような条件で、ガラス基板上に前述のようなパターン（図１４）を形成し、形成後のパターン評価を行うとともに、それと同じ条件で、別途噴射実験を行い、吐出口から３ｍｍ先の溶液の噴射状況を観察した。これは図１４のテストパターンを基板と吐出口間距離を３ｍｍとして製作したからである。飛翔形態は図１１に示したように、飛翔方向に非常に細長く伸びた柱状（ｌ＝５ｄ〜２０ｄ）であった。また、飛翔滴後方に複数の微小滴（サテライト微小滴８１）を伴ったような状態であった。以下に検討結果を表５に示す。
【００９６】
【表５】

【００９７】
以上の結果より、キャリッジのＸ方向移動速度が、噴射速度の１／３を超えると、良好な素子が形成できないことがわかる。なおこの例は、噴射ヘッドをキャリッジ走査した例であるが、図３のように噴射ヘッドを固定し、基板を移動させる場合にも適用される。すなわち、噴射ヘッドと基板の相対移動速度は、噴射される溶液の速度の１／３以下にしなければならないということである。
【００９８】
以上の説明から明らかなように、本発明は、パターン配線基板あるいはデバイス基板を製作する技術であるが、数１０μｍ〜数μｍという非常に微細なパターンを従来のようなフォトリソ技術によるのではなく、従来にはない微小な吐出口を有する噴射ヘッドによって微粒子含有溶液の液滴を基板に直接噴射付与するという簡単な装置で、パターンやデバイスをダイレクト製作するようにしている。したがって、いわゆる半導体製造プロセスで使用されている高価な製造装置を必要とせず、低コストでかつ安定して製作できるようになった。
【００９９】
【発明の効果】
吐出口径がΦ２０μｍ以下の噴射ヘッドによって微粒子含有溶液の液滴を膜沸騰気泡の成長作用力で複数滴噴射付与し、パターン配線基板あるいはデバイス基板を製造する溶液噴射製造装置において、微粒子の大きさと吐出口径を最適化し、目詰まりのない安定した噴射を実現したので、新規な手法による高精度かつ高品質なパターン配線基板あるいはデバイス基板を低コストで製作できるようになった。また、基板と噴射ヘッドとの相対移動速度をその溶液の噴射速度の１／３以下としたので、新規な手法による高精度かつ高品質なパターン配線基板あるいはデバイス基板を低コストで製作できるようになった。
【０１００】
また、上記効果に加え、高速に噴射、飛翔できて高い着弾精度が実現できる噴射、飛翔条件としたので、新規な手法による高精度かつ高品質なパターン配線基板あるいはデバイス基板を低コストで製作できるようになった。
【０１０１】
上述のような新規な構成の液滴噴射製造装置によって製作されるパターン配線基板あるいはデバイス基板であるので、高精度、高品質かつ低コストのパターン配線基板あるいはデバイス基板が得られるようになった。
【図面の簡単な説明】
【図１】本発明の溶液噴射製造装置によって形成されるパターン配線の一実施例を説明するための図である。
【図２】本発明のパターン配線基板あるいはデバイス基板を製造する溶液噴射製造装置の一実施例を説明するための図である。
【図３】本発明のパターン配線基板あるいはデバイス基板を製造する溶液噴射製造装置の他の実施例を説明するための図である。
【図４】本発明のパターン配線基板あるいはデバイス基板の製造に適用される溶液付与装置を示す概略構成図である。
【図５】本発明に好適に使用されるピエゾ素子利用の噴射ヘッドの液滴噴射原理を説明する図である。
【図６】本発明に好適に使用されるピエゾ素子利用の噴射ヘッドの構造を示す図である。
【図７】本発明に好適に適用されるサーマル方式（バブル方式）の液体噴射ヘッドの例である。
【図８】マルチノズル型の液体噴射ヘッドをノズル側から見た図である。
【図９】マルチノズル型の液体噴射ヘッドを噴射する溶液ごとに積層し、ユニット化した図である。
【図１０】このようにユニット化したヘッドの斜視図ある。
【図１１】本発明の溶液噴射製造装置に使用される噴射ヘッドで膜沸騰気泡による作用力で噴射した場合の溶液飛翔形状の例を説明するための図である。
【図１２】本発明の溶液噴射製造装置に使用される噴射ヘッドで機械的変位による作用力で噴射した場合の液滴飛翔形状の例を説明するための図である。
【図１３】本発明の溶液噴射製造装置に使用される噴射ヘッドで機械的変位による作用力で噴射した場合の他の液滴飛翔形状の例を説明するための図である。
【図１４】本発明の溶液噴射製造装置によって、良好なパターン形成を行う条件を見出すために使用したテストパターンの例を示す図である。
【符号の説明】
１…配線パターン、２，３…端子、１０…基板、１１…吐出ヘッドユニット（噴射ヘッド）、１２…キャリッジ、１３…基板保持台、１４…基板、１５…微粒子含有溶液の供給チューブ、１６…信号供給ケーブル、１７…噴射ヘッドコントロールボックス、１８…Ｘ方向スキャンモータ、１９…Ｙ方向スキャンモータ、２０…コンピュータ、２１…コントロールボックス、２２…基板位置決め／保持手段、３１…ヘッドアライメント制御機構、３２…検出光学系、３３…噴射ヘッド、３４…ヘッドアライメント微動機構、３５…制御用コンピュータ、３６…画像識別機構、３７…ＸＹ方向走査機構、３８…位置検出機構、３９…位置補正制御機構、４０…インクジェットヘッド駆動・制御機構、４１…光軸、４２…素子電極、４３…液滴、４４…液滴着弾位置、４５…流路、４６…ピエゾ素子、４７…溶液、４８…（液体噴射ヘッド）ノズル、４９…フィルター、６５…ノズル、６６…発熱体基板、６７…蓋基板、６８…シリコン基板、６９…個別電極、７０…共通電極、７１…発熱体、７４…溝、７５…凹部領域、７６…溶液流入口、８１…サテライト微小滴、８２…素子電極（ＩＴＯ透明電極）、８３…ドットパターン、８４…微小滴。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for forming a wiring substrate or a functional device by ejecting a material containing fine particles by using a discharge device to form a pattern, and a pattern substrate or a functional device substrate formed by the apparatus.
[0002]
[Prior art]
In recent years, various devices such as a light-emitting device / medium and an optical processing device / medium using fine particles / ultrafine particles have been studied. For application of such fine particles to an element, high-density integration obtained by depositing a film or layer of a fine particle-containing material on a solid substrate is important. The thin film in which the fine particles are integrated at a high density is specifically applied to Non-Patent Document 1, Non-Patent Document 2, Non-Patent Document 3, Non-Patent Document 4, Non-Patent Document 5, Non-Patent Document 6, and the like. Have been.
[0003]
On the other hand, as a method of forming an inorganic compound thin film having excellent orientation, a molecular beam epitaxy method (MBE), a cluster ion beam method, an ion beam irradiation vacuum deposition method, a chemical vapor deposition method (CVD), and a physical vapor deposition method ( PVD), liquid phase epitaxy (LPE) and the like are known.
As a method for forming an organic compound thin film, a Langmuir-Blodgett method (LB method) and the like are known. What is generally called a quantum dot can be manufactured by utilizing a process in which a raw material sublimated in a high vacuum using a vacuum apparatus such as the MBE method described above forms dots in a self-organizing manner on a solid substrate. it can.
[0004]
However, in the above method, it is difficult to control the distance between dots and the size distribution, and there is a problem that a large cost is required to control the structure to a desired structure. Therefore, as a technique capable of solving such a problem, it has been proposed to form a film of a material containing fine particles by the ink jet principle, that is, by a liquid jet head. For example, Patent Literature 1 discloses an ultra-violet light having an ability to inkjet-coat an emulsion containing nanoparticles on a solid substrate and increase or increase and memorize the photoluminescence intensity as a function of the irradiation time or irradiation amount of the excitation light. A method of forming a thin film composed of an aggregate of fine particles (nanoparticles) on a solid substrate has been proposed.
[0005]
Also, studies have been made to apply the same principle to the fabrication of circuit boards in addition to such functional elements. For example, the following method is conventionally known as a method for manufacturing a circuit board.
(1) A method in which a resist is coated on a copper-clad laminate, and a photolithography method is used to form a copper wire pattern by exposing a circuit pattern, dissolving and removing an unexposed resist, and etching a resist-removed portion.
(2) A method in which a conductive paste is printed in a desired circuit pattern on a ceramic substrate by screen printing, and heat treatment is performed in a non-oxidizing atmosphere to sinter metal fine particles in the conductive paste to form a conductive pattern.
(3) A thin conductive layer is formed on the insulating substrate by vapor deposition of a conductive metal, a resist is coated on the conductive layer, and a circuit pattern is exposed by a photolithography method, and the unexposed resist is dissolved and removed. A method of forming a copper wire pattern by etching a removed portion.
[0006]
However, these methods have a problem that they are not suitable for forming a fine pattern. For example, Patent Document 2 discloses that a circuit pattern is directly drawn on a substrate by a metal paste using an inkjet head. A method of forming a wiring pattern and a method of manufacturing a circuit board have been proposed in which a fine pattern can be easily formed, no waste liquid treatment is required, a production process is simple, and equipment costs and production costs can be reduced.
[0007]
On the other hand, the present inventor has already proposed as Patent Document 3 an invention of manufacturing an electron source substrate using the ink jet principle.
As described above, various proposals using the ink jet principle have begun to be made, but the idea of manufacturing various devices or pattern substrates by such means is still new, and a more specific method is still unknown. It is a fact that there are many parts and it is in a fumbling state.
[0008]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-126681 [Patent Document 2]
JP 2002-134878 A [Patent Document 3]
Japanese Patent Application Laid-Open No. 2001-319567 [Non-Patent Document 1]
Light emitting device (LED) (Alivisatoset al.)
[Non-patent document 2]
Photoelectric conversion element (Greenham, NC, et al., Phys. Rev. B, 54, 17628 (1996))
[Non-Patent Document 3]
Ultrafast detector (Bhargava)
[Non-patent document 4]
Electroluminescent displays and panels (Bhargava, Alivisatoset al.)
[Non-Patent Document 5]
Nanostructured memory device (Chenet al.)
[Non-Patent Document 6]
Multicolor devices consisting of nanoparticle arrays (Dushkin et al.)
[0009]
[Problems to be solved by the invention]
(Object of the invention)
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object is to provide a novel solution jet manufacturing apparatus for manufacturing a high quality pattern wiring board or device board.
It is a second object of the present invention to perform stable solution jetting and to manufacture a high-quality pattern wiring board or device board in the above-described solution jetting manufacturing apparatus.
A third object is to provide a high-precision and high-quality pattern wiring board manufactured by the solution jet manufacturing apparatus having a novel configuration as described above.
A fourth object is to provide a high-precision and high-quality device substrate manufactured by the solution jet manufacturing apparatus having a novel configuration as described above.
[0010]
[Means for Solving the Problems]
The present invention, in order to achieve the above object,
First, a solution containing fine particles is sprayed onto a substrate by a spraying head having a discharge port diameter of Φ20 μm or less, and a pattern is formed in such a manner as to contact the energized region on the substrate so as to cover from above. In a solution jet manufacturing apparatus for forming a pattern wiring or a device by volatilizing a volatile component in a pattern formed by and leaving a solid content on the substrate and the energized region, the size of the fine particles is Dp, When the discharge port diameter is Do, 0.0001 ≦ Dp / Do ≦ 0.01, and the ejection head ejects the solution with the growth action force of the film boiling bubbles generated instantaneously in the solution. The shape at the time of the solution flight is an elongated columnar shape extending in the flight direction and having a length of 5 times or more the diameter thereof, and the relative movement speed between the substrate and the ejection head is It was 1/3 or less of the injection rate of the solution.
Second, in the first solution jet manufacturing apparatus, the solution of the elongated column-shaped solution at the time of flying is caused to fly at a high speed with a plurality of fine droplets rearward.
Third, a patterned wiring substrate is formed by the first or second solution jet manufacturing apparatus.
Fourth, a device substrate is formed by the first or second solution jet manufacturing apparatus.
Note that the substrate includes a substrate formed of a sheet or a film.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an example in which a pattern is formed on a substrate 10 such as a glass substrate, a plastic substrate, a semiconductor substrate such as Si, a glass / epoxy substrate, a flexible substrate or the like by the method of the present invention. FIG. 1A shows a state in which terminals 2 and 3 are formed on such a substrate 10, and a dotted line portion 1 'in FIG. 1A is an area where a wiring pattern as described later is generated. is there. FIG. 1B shows an example in which a solution containing fine conductive fine particles is ejected and drawn according to the droplet ejection principle to form a wiring pattern 1.
Here, as a means for applying a solution containing fine conductive fine particles, an ink jet technique is applied in the present invention. The specific method will be described below.
[0012]
FIG. 2 is a view for explaining an embodiment of a manufacturing apparatus for forming a pattern wiring board or a functional device according to the present invention. In the figure, 11 is an ejection head unit (ejection head), 12 is a carriage, and 13 is a carriage. A substrate holder, 14 a substrate such as a wiring substrate or a functional element substrate or a substrate forming a functional device, 15 a supply tube for a solution containing fine conductive fine particles, 16 a signal supply cable, 17 a jet head A control box (including a solution tank), 18 is an X-direction scan motor of the carriage 12, 19 is a Y-direction scan motor of the carriage 12, 20 is a computer, 21 is a control box, and 22 ( _22X1 , _22Y1 , _22X2 , _22Y2). ) Is a substrate positioning / holding means. In this case, the ejection head 11 is moved by carriage scanning on the front surface of the substrate 14 placed on the substrate holding table 13 to eject a solution containing fine conductive fine particles.
[0013]
FIG. 3 is a schematic view showing the configuration of a droplet applying apparatus applied to the manufacture of a patterned wiring board or the formation of a functional device according to the present invention. FIG. FIG. 4 is a schematic diagram of a section.
[0014]
The configuration in FIG. 3 differs from the configuration in FIG. 2 in that a wiring pattern or a functional device is formed on the substrate by moving the substrate 14 side. 3 and 4, 31 is a head alignment control mechanism, 32 is a detection optical system, 33 is an ejection head, 34 is a head alignment fine movement mechanism, 35 is a control computer, 36 is an image identification mechanism, and 37 is an XY scanning mechanism. 38, a position detection mechanism, 39, a position correction control mechanism, 40, an ink jet head driving / control mechanism, 41, an optical axis, 42, an element electrode, 43, a droplet, and 44, a droplet landing position.
[0015]
The droplet applying device (ejection head 33) of the ejection head unit 11 may be any mechanism as long as it can discharge a given amount of droplets in a fixed amount, and in particular, an ink jet principle capable of forming droplets of about 0.1 pl to several hundred pl. Mechanism is desirable.
[0016]
Examples of the ink jet system include a system disclosed in US Pat. No. 3,683,212 (Zoltan system), a system disclosed in US Pat. No. 3,747,120 (Stemme system), and US Pat. No. 3,946,398. As described in the method (Kyser method), an electric signal is applied to the piezo-vibration element, and the electric signal is converted into a mechanical vibration of the piezo-vibration element. There is a type in which droplets are ejected and fly, which is generally called a drop-on-demand system.
[0017]
As another method, there is a method (Sweet method) disclosed in US Pat. No. 3,596,275, US Pat. No. 3,298,030, and the like. This generates droplets of the recording liquid whose charge amount is controlled by the continuous vibration generation method, and the generated droplets whose charge amount is controlled fly between the deflection electrodes to which a uniform electric field is applied. By doing so, recording is performed on the recording member, which is usually called a continuous flow method or a charge control method.
[0018]
As another method, there is a method disclosed in Japanese Patent Publication No. 56-9429. In this method, bubbles are generated in a liquid, and droplets are ejected and fly from a fine nozzle by the action force of the bubbles. This is called a thermal ink jet system or a bubble jet (R) system.
[0019]
The method of ejecting the droplets in this way includes a drop-on-demand method, a continuous flow method, a thermal ink jet method, and the like, and the method may be appropriately selected as needed.
[0020]
In the present invention, in a manufacturing apparatus (FIG. 2) for forming such a pattern wiring substrate or a functional device, the holding position of the substrate 14 is determined by adjusting the holding position by the board positioning / holding means 22 of the apparatus. Although simplified in FIG. 2, the substrate positioning / holding means 22 is in contact with each side of the substrate 14 and can be finely adjusted in the X direction and the Y direction orthogonal thereto in the order of submicrons. The control unit is connected to the ejection head control box 17, the computer 20, the control box 21, and the like, so that the positioning information and the fine adjustment displacement information and the like, and the position information and timing of the droplet application can be constantly fed back.
[0021]
Furthermore, in the manufacturing apparatus for forming the pattern wiring board or the functional device of the present invention, in addition to the position adjustment mechanism in the X and Y directions, a rotation position adjustment mechanism not shown (not visible because it is located below the substrate 14). have. In this regard, the shape of the pattern wiring substrate or the functional device forming substrate of the present invention, the arrangement of the functional device groups to be formed, and the like will be described first.
[0022]
The pattern wiring substrate or the functional device forming substrate of the present invention may be a glass substrate, a ceramic substrate, various plastic substrates such as PET, a semiconductor substrate such as Si, a glass / epoxy substrate, a polyimide film, depending on its purpose and application. A flexible substrate made of a polymer film such as a polyamideimide film, a polyamide film, and a polyester film is preferably used. For example, various plastic substrates and polymer films are effective for patterned wiring boards or functional devices that require light weight.
[0023]
The shapes of various plastic substrates and polymer fills used for the pattern wiring substrate or the functional device forming substrate of the present invention are economical to produce and supply such a substrate, or to finally produce a functional device forming substrate It is rectangular because of the use. In other words, the vertical and horizontal sides of the rectangular shape are parallel to each other, the horizontal and horizontal sides are parallel to each other, and the vertical and horizontal sides are at right angles.
[0024]
In the present invention, a group of functional devices to be formed is arranged in a matrix on such a substrate, and two directions orthogonal to each other in the matrix correspond to directions of a vertical side or a horizontal side of the substrate. Arrange the functional devices so as to be parallel. The reason for arranging the functional device groups in a matrix and the reason for making the vertical and horizontal sides of the substrate parallel to two orthogonal directions of the matrix will be described below.
[0025]
As shown in FIG. 2 or FIG. 3, in the present invention, after the positional relationship between the substrate 14 and the solution ejection surface of the ejection head unit 11 is determined first, no particular position control is performed. In other words, the ejection head unit 11 ejects the solution while performing relative movement in the X and Y directions in parallel with the functional device group formation surface while keeping a certain distance from the substrate 14. In other words, the X direction and the Y direction are two directions orthogonal to each other. If the vertical side or the horizontal side of the substrate is set to be parallel to the Y direction or the X direction when positioning the substrate, Since the two functional device groups are also arranged in two parallel directions in the matrix, the device groups can be formed with high accuracy only by the mechanism that performs the relative movement and the ejection. In other words, if the substrate shape as in the present invention, the matrix arrangement of functional device groups, and the relative movement device in two orthogonal X and Y directions are used, the positioning of the substrate before performing the droplet formation for device formation can be performed. If done correctly, a high-precision matrix-like array of functional devices can be obtained.
[0026]
Here, the description will return to the rotation position adjustment mechanism described above. As described above, in the present invention, the positioning of the substrate before performing the droplet ejection for device formation is performed accurately, only the relative movement in the X and Y directions is performed, and no other control is performed. The aim is to obtain a matrix-like array of groups. In this case, a problem is a deviation in a rotation direction (a rotation direction with respect to an axis perpendicular to a plane determined by the two directions X and Y) when the substrate is first positioned.
In order to correct the deviation in the rotation direction, the present invention has a rotation position adjustment mechanism (not shown but located below the substrate 14) as described above. Accordingly, when the displacement in the rotation direction is also corrected and the side of the substrate is positioned, the apparatus of the present invention can obtain a high-precision matrix of functional device groups by relative movement only in the X and Y directions.
[0027]
In the above, this rotation position adjusting mechanism has been described as a mechanism separate from 22 (22 _X1 , 22 _{Y 1} , 22 _{X 2} , 22 _{Y 2} ) by the substrate positioning / holding means of FIG. However, it is also possible to provide the substrate positioning / holding means 22 with a rotation position adjusting mechanism. For example, the substrate positioning / holding unit 22 is in contact with the side of the substrate 14 so that the position of the entire substrate positioning / holding unit 22 can be adjusted in the X direction or the Y direction. The angle can be adjusted by allowing two screws provided at a distance to move independently of each other at a portion of the substrate 22 that is in contact with the side of the substrate 14. The rotation position control information is also connected to the ejection head control box 17, the computer 20, the control box 21 and the like in the same manner as the above-described positioning information in the X and Y directions and the fine adjustment displacement information. Timing and the like can be constantly fed back.
[0028]
The above description is based on the premise that the substrate preferably used in the present invention is basically rectangular, except that a semiconductor substrate such as Si is supplied as a round wafer, In this case, one side of a straight line called an orientation flat (orientation flat) indicating the direction of the crystal orientation axis may be brought into contact with the substrate positioning / holding means 22.
[0029]
Next, other means and configurations for positioning according to the present invention will be described. In the above description, the substrate positioning / holding means 22 is in contact with the side of the substrate 14 so that the position of the entire substrate positioning / holding means 22 can be adjusted in the X direction or the Y direction. A description will be given of an example in which strip patterns are provided not in the sides of the substrate 14 but in two directions orthogonal to each other on the substrate. As described above, in the present invention, the functional device groups are formed on the substrate by arranging them in a matrix. It is formed so as to be parallel. Such a pattern can be easily formed on a substrate by a photofabrication technique.
[0030]
The present invention is applied not only to the case of forming a large number of functional device groups arranged in a matrix but also to the case of forming a wiring pattern as shown in FIG. As in this example, they are formed in two orthogonal directions, and are formed so as to be parallel to the vertical and horizontal directions (X direction, Y direction) of the substrate, respectively. This wiring pattern may be formed as a pattern for such a positioning purpose at a position where the original function of the substrate of the present invention is not impaired, or may be formed as a device electrode 42 (FIG. 4) or each device. The wiring pattern such as the X-direction wiring and the Y-direction wiring may be regarded as a two-way strip pattern perpendicular to each other in the present invention. If such a band-shaped pattern is provided, the pattern can be detected by a detection optical system 32 using a CCD camera and a lens, as described later with reference to FIG. 4, and can be fed back to position adjustment.
[0031]
Next, in the Z direction, which is a direction perpendicular to the X and Y directions, in the present invention, after the positional relationship between the substrate 14 and the solution ejection surface of the ejection head unit 11 is determined first, in particular, There is no position control. In other words, the ejection head unit 11 performs the relative movement in the X and Y directions while maintaining a certain distance (1 to 3 mm) with respect to the substrate 14, and ejects the solution containing fine conductive fine particles. At the time of ejection, the position control of the ejection head unit 11 in the Z direction is not particularly performed. The reason is that if the control is performed at the time of ejection, not only the mechanism, the control system, and the like become complicated, but also the formation of the functional device by applying the droplets to the substrate 14 is delayed, and the productivity is significantly reduced. .
[0032]
Instead, in the present invention, the flatness of the substrate 14 and the flatness of the device holding the substrate 14 and the accuracy of a carriage mechanism and the like for relatively moving the ejection head unit 11 in the X and Y directions are improved. By doing so, the relative movement of the ejection head unit 11 and the substrate 14 in the X and Y directions is performed at high speed without performing the Z-direction control at the time of ejection, thereby improving productivity. As an example, the variation in the distance between the substrate 14 and the solution ejection surface of the ejection head unit 11 when applying the solution of the present invention (during ejection) is suppressed to 2 mm or less (the size of the substrate 14 is 100 mm × 100 mm or more). , 4000 mm x 4000 mm or less).
[0033]
Note that the device is usually configured so that the plane determined by the two directions of the X and Y directions is kept horizontal (a plane perpendicular to the vertical direction), but when the substrate 14 is small (for example, 500 mm × 500 mm or less). In (2), it is not always necessary to make a plane determined by the two directions of X and Y horizontal, and it is only necessary to make the positional relationship of the substrate 14 most efficient for the device.
[0034]
Next, the configuration of the ejection head unit 11 will be described with reference to FIG. In FIG. 4, reference numeral 32 denotes a detection optical system that captures image information on the substrate 14, which is close to the ejection head 33 that ejects the droplet 43, and that is based on the optical axis 41 and the focal position of the detection optical system 32 and the ejection head 33. The droplet 43 is disposed so that the droplet landing position 44 of the droplet 43 coincides with the droplet landing position 44.
[0035]
In this case, the positional relationship between the detection optical system 32 and the ejection head 33 shown in FIG. 3 can be precisely adjusted by the head alignment fine movement mechanism 34 and the head alignment control mechanism 31. The detection optical system 32 uses a CCD camera and a lens.
[0036]
In FIG. 3, reference numeral 36 denotes an image identification mechanism for identifying the image information captured by the detection optical system 32, and has a function of binarizing the contrast of the image and calculating the position of the center of gravity of the binarized specific contrast portion. It had. Specifically, a high-precision image recognition device VX-4210 manufactured by KEYENCE CORPORATION can be used. A means for giving the position information on the functional element substrate 14 to the obtained image information is the position detection mechanism 38. For this, a length measuring device such as a linear encoder provided in the XY direction scanning mechanism 37 can be used. A position correction control mechanism 39 performs position correction based on the image information and the position information on the functional element substrate 14, and the movement of the XY direction scanning mechanism 37 is corrected by this mechanism. Can be In addition, the ejection head 33 is driven by the inkjet head drive / control mechanism 40, and droplets are applied onto the functional element substrate 14. The above-described control mechanisms are centrally controlled by the control computer 35.
[0037]
By the way, FIG. 4 shows a diagram in which droplets are ejected obliquely to the substrate surface. This is because the detection optical system 32 and the ejection head 33 are shown together, and thus the droplets fly obliquely. However, in practice, the spray is applied so as to hit the substrate almost perpendicularly.
[0038]
In the above description, the ejection head unit 11 is fixed, and the relative movement between the ejection head unit 11 and the functional element substrate 14 is performed by moving the functional element substrate 14 to an arbitrary position by the XY direction scanning mechanism 37. However, needless to say, as shown in FIG. 2, the functional element substrate 14 may be fixed and the ejection head unit 11 may scan in the XY directions. In particular, when the present invention is applied to the production of a medium-sized substrate of about 200 mm × 200 mm to a large substrate of 2000 mm × 2000 mm or more, the functional element substrate 14 is fixed as in the latter case, and the X, Y It is preferable that the scanning is performed in the two directions described above, and the application of the solution droplets is sequentially performed in such two orthogonal directions.
[0039]
When the substrate size is about 200 mm × 200 mm or less, the ejection head unit for applying droplets is of a large array multi-nozzle type capable of covering a range of 200 mm, and the relative movement between the ejection head unit and the substrate is orthogonal. It is also possible to perform relative movement only in one direction (for example, only the X direction) without performing in the direction (X direction, Y direction), and mass productivity can be improved, but the substrate size is 200 mm × 200 mm. In the above case, it is difficult to technically and costly to manufacture a large-array multi-nozzle type ejection head unit that can cover such a range of 200 mm. Scanning is performed in two orthogonal directions, X and Y, and the application of liquid droplets is sequentially performed in such two orthogonal directions. It is better to adopt a configuration in which
[0040]
In particular, as a final substrate, even when a substrate smaller than 200 mm × 200 mm is manufactured, when a plurality of large substrates are to be manufactured, the original substrate is 400 mm × 400 mm or more. Since a size of 2000 mm × 2000 mm or more is used, the ejection head unit 11 is made to scan in two orthogonal directions, X and Y, and the application of the solution droplet is performed in the two orthogonal directions. It is better to adopt a configuration in which the operations are performed sequentially.
[0041]
As a material of the droplet 43, a solution containing fine conductive fine particles is used. For example, Au, Pt, Ag, Cu, Ni, Cr, Rh, Pd, Zn, Co, Mo, Ru, W, Os A solution containing fine metal particles such as, Ir, Fe, Mn, Ge, Sn, Ga, and In is preferably used.
In particular, when metal fine particles such as Au, Ag, and Cu are used, a fine circuit pattern having low electric resistance and high corrosion resistance can be formed.
[0042]
In the present invention, the solution containing such fine conductive fine particles includes an aqueous solution and an oil solution.
An aqueous solution obtained by dispersing such fine conductive fine particles in a dispersion medium mainly composed of water can be prepared, for example, by the following method.
That is, a water-soluble polymer is dissolved in an aqueous solution of a metal ion source such as chloroauric acid or silver nitrate, and an alkanolamine such as dimethylaminoethanol is added with stirring. In several tens seconds to several minutes, the metal ions are reduced, and metal fine particles having an average particle size of 0.5 μm (500 nm) or less are precipitated. After removing chlorine ions and nitrate ions by a method such as ultrafiltration, the solution is concentrated and dried to obtain a solution containing concentrated conductive fine particles. The solution containing conductive fine particles can be stably dissolved and mixed in water, an alcohol-based solvent, or a binder for a sol-gel process such as tetraethoxysilane or triethoxysilane.
[0043]
An oil-based solution obtained by dispersing fine conductive fine particles in a dispersion medium mainly composed of oil can be prepared, for example, by the following method.
That is, an oil-soluble polymer is dissolved in a water-miscible organic solvent such as acetone, and this solution is mixed with an aqueous metal ion source solution. The mixture is a heterogeneous system, but when alkanolamine is added while stirring the mixture, the metal fine particles are precipitated on the oil phase side in a form dispersed in the polymer. When this is concentrated and dried, a concentrated conductive fine particle-containing solution similar to that of an aqueous system is obtained. The solution containing the conductive fine particles can be stably dissolved and mixed in an aromatic, ketone, ester or other solvent, polyester, epoxy resin, acrylic resin, polyurethane resin or the like.
[0044]
The concentration of the conductive fine particles in the dispersion medium of the conductive fine particle-containing solution can be up to 80% by weight, but it is appropriately diluted according to the intended use.
Usually, the content of the conductive fine particles in the conductive fine particle-containing solution is suitably 2 to 50% by weight, the content of the surfactant and the resin is 0.3 to 30% by weight, and the viscosity is suitably 3 to 30 centipoise.
[0045]
In any of the materials, the present invention volatilizes volatile components in a solution and leaves a solid content on a substrate to form a pattern wiring or a functional device. The solids generate the function of each pattern or device, and the solvent (volatile component) is a vehicle for ejecting and applying droplets by the ink jet principle.
[0046]
Other examples of the material of the droplet 43 include an I-VII compound semiconductor such as CuCl, a II-VI compound semiconductor such as CdS and CdSe, a III-V compound semiconductor such as InAs, and a IV semiconductor. Semiconductor oxides, TiO ₂ , SiO, metal oxides such as SiO ₂ , phosphors, fullerenes, inorganic compounds such as dendrimers, phthalocyanines, organic compounds such as azo compounds, or nanoparticles of composite materials thereof. Contained solution.
[0047]
Nanoparticles targeted in the present invention are usually fine particles having a particle size of 0.0005 to 0.2 μm (0.5 to 200 nm), preferably 0.0005 to 0.05 μm (0.5 to 50 nm). More specifically, it is determined in consideration of the dispersion stability of fine particles in the production of a solution, the occurrence of clogging during injection described later, and the like.
[0048]
Incidentally, within the range not impairing the object of the present invention, the surface of these nanoparticles may be chemically or physically modified, or an additive such as a surfactant, a dispersion stabilizer or an antioxidant may be added. good. Such nanoparticles can be obtained by a colloid chemistry method such as a reverse micelle method (Lianos, P. et al., Chem. Phys. Lett., 125, 299 (1986)) or a hot soap method (Peng, X. et al. ., J. Am. Chem. Soc., 119, 7019 (1997)).
[0049]
The nanoparticle-containing solution that can be suitably used in the present invention is a dispersion in which the above-mentioned nanoparticles are dispersed in an emulsion in which the continuous phase is an aqueous phase and the dispersed phase is an oil phase (O / W emulsion).
The aqueous phase is mainly composed of water, but may be used by adding a water-soluble organic solvent to water. Examples of the water-soluble organic solvent include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200, # 400), glycerin, alkyl ethers of the above glycols, N-methylpyrrolidone, 1,3- Dimethylimidazolinone, thiodiglycol, 2-pyrrolidone, sulfolane, dimethylsulfoxide, diethanolamine, triethanolamine, ethanol, isopropanol and the like. The amount of the water-soluble organic solvent used in the aqueous dispersion medium is usually preferably 30% by weight or less, and more preferably 20% by weight.
[0050]
The content of the nanoparticles in the dispersion depends on the desired film (layer) structure or particle arrangement structure and the film (layer) thickness, but is usually in the range of 0.01 to 15% by weight based on the total weight of the dispersion. Although it is used, it is more preferably in the range of 0.05 to 10% by weight. If the content of the nanoparticles is too small, there is a possibility that the device function cannot be sufficiently exhibited, and if it is too large, the ejection stability at the time of ejecting the droplet by the ink jet principle is impaired.
[0051]
Further, in the nanoparticle-containing solution that is suitably used in the present invention and is sprayed by the inkjet principle, it is preferable that a surfactant and a solvent for dispersing the nanoparticles coexist in the dispersion. Examples of the surfactant include anionic surfactants (sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium laurate, ammonium salts of polyoxyethylene alkyl ether sulfate, etc.), and nonionic surfactants (polyoxyethylene alkyl Ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, etc., and these may be used alone or in combination of two or more. be able to.
[0052]
The amount of the surfactant is usually used in the range of 0.1 to 30% by weight based on the total weight of the solution, and is more preferably in the range of 5 to 20% by weight. If the amount of the surfactant is less than this range, oil-water separation occurs in the aqueous dispersion, and a uniform pattern of coating may not be obtained by applying droplets. Conversely, if it is more than this range, the viscosity of the aqueous dispersion medium tends to be too high.
[0053]
The solvent for dispersing the nanoparticles is usually a liquid such as toluene, hexane, pyridine, or chloroform, and is preferably volatile. The amount of the dispersing solvent is usually used in the range of about 0.1 to 20% by weight, but is more preferably in the range of 1 to 10% by weight. If the amount of the dispersing solvent is too small, the amount of ultrafine particles that can be contained in the aqueous medium will be small. Conversely, if it is more than this range, oil-water separation may occur in the aqueous dispersion medium.
[0054]
Further, the organic compound can be dissolved in the dispersion. Examples of such organic compounds include trioctylphosphine oxide (TOPO), thiophenol, photochromic compounds (spiropyran, fulgide, etc.), charge transfer complexes, electron-accepting compounds, etc., and those which are solid at room temperature are preferred. . In this case, the amount of the organic compound in the dispersion is 1 / 10,000 or more, preferably about 1/1000 to 10 times the weight of the nanoparticles.
[0055]
In addition, as long as the object of the present invention is not impaired, an additive such as a surfactant, a dispersion stabilizer or an antioxidant, or a polymer or a binder such as a material that gels in a coating and drying process is added to the suspension. Is also good.
Droplets of such a nanoparticle-containing solution are applied onto a substrate by the ink jet principle and dried to form a pattern wiring or a functional device. In the present invention, for example, first, at atmospheric pressure, air drying at -20 to 200 ° C., preferably about 0 to 100 ° C. for 1 hour or more, preferably 3 hours or more, and then drying under reduced pressure if necessary. good. The degree of pressure reduction at this time may be 1 × 10 ⁵ Pa or less, preferably about 1 × 10 ⁴ Pa or less, and the temperature is usually −20 to 200 ° C., preferably 0 to 100 ° C. The decompression time is about 1 to 24 hours.
[0056]
Although the thickness of the nanoparticle thin film obtained by the above method is not particularly limited, it is generally about 1 mm in diameter of the nanoparticle, preferably about 100 μm in diameter of the nanoparticle. Further, it is preferable that the nanoparticles exist at a certain density or higher in the nanoparticle thin film. In that sense, the average interparticle distance between the individual nanoparticles in the aggregate of nanoparticles is usually within the range of 10 times the particle diameter, and more preferably within the range of 2 times the particle diameter. If the average interparticle distance is too large, the nanoparticles will not exhibit collective function.
[0057]
Next, a liquid jet head suitably applied to the present invention will be described with reference to FIGS. This example is an example of seven nozzles.
This liquid jet head is provided with a piezo element 46 as an energy action section in a flow path 45 into which a solution 47 is introduced. When a pulse-like signal voltage is applied to the piezo element 46 to distort the piezo element 46 as shown in FIG. 5A, the volume of the flow path 45 is reduced and a pressure wave is generated. A droplet 43 is ejected from 48. FIG. 5B shows a state where the distortion of the piezo element 46 is eliminated and the volume of the flow channel 45 is increased.
[0058]
Here, the solution 47 introduced into the flow channel 45 immediately before the nozzle 48 has passed through the filter 49. As described above, in the present invention, the filter 49 is provided in the ejection head, and a filter removing function is provided near the nozzle 48. By doing so, foreign particles larger than those other than the conductive fine particles or nanoparticles in the solution of the present invention are trapped, and the performance of the pattern or device formed on the substrate is not reduced. . Such a filter 49 can be incorporated in the ejection head 11 as shown in FIG. 6 by using a small-sized simple filter. Further, the ejection head 11 itself can be made compact.
As such a filter 49, for example, a stainless mesh filter is suitably used, and the pore size (filter mesh size) is set to 0.8 μm to 2 μm.
[0059]
Next, another example of the liquid jet head suitably applied to the present invention will be described with reference to FIG. This example is an example of a thermal type (bubble type) liquid jet head, and the driving force of the droplet jetting is a growth force of film boiling bubbles generated instantaneously in a solution.
The liquid ejecting head shown here is of a type in which droplets are ejected from a short portion of a flow path through which a solution flows, and is called an edge shooter type.
Here, an example is shown in which the number of nozzles of the liquid ejecting head is four. This liquid ejecting head is formed by joining a heating element substrate 66 and a lid substrate 67. The heating element substrate 66 is formed on a silicon substrate 68 by an individual electrode 69, a common electrode 70, and an energy action section by a wafer process. Is formed by forming a heating element 71 which is
[0060]
On the other hand, the lid substrate 67 has a groove 74 for forming a flow channel into which a solution containing a functional material is introduced, and a common liquid chamber for accommodating the solution to be introduced into the flow channel. A concave region 75 is formed, and the flow path and the common liquid chamber are formed by joining the heating element substrate 66 and the lid substrate 67 as shown in FIG. In a state where the heating element substrate 66 and the lid substrate 67 are joined, the heating element 71 is located at the bottom of the flow path, and the solution introduced into these flow paths is located at the end of the flow path. The nozzle 65 for discharging a part of the liquid as droplets is formed. Here, the nozzle shape is rectangular, but this may be round.
[0061]
Further, in consideration of the ejection stability, a nozzle plate may be separately provided on the end face (the area of the nozzle 65) to have a desired nozzle diameter and a desired nozzle shape (for example, a round shape). In this case, for example, Ni is used as the nozzle plate, and a high-precision object can be formed by a method such as electroforming. Alternatively, it is also a good method to use a resin film (substrate) in which nozzle holes are formed by excimer laser processing.
The lid substrate 67 is provided with a solution inlet 76 for supplying a solution into the supply liquid chamber by a supply unit (not shown).
[0062]
In the present invention, one functional element is formed by a plurality of droplets, or a pattern for forming a functional element or the like is formed by overlapping or contacting dots with a plurality of droplets. Therefore, when such a multi-nozzle type liquid ejecting head is used, a functional element can be formed very efficiently. In this example, the liquid ejecting head has four nozzles. However, the number of nozzles is not necessarily limited to four, and it goes without saying that the larger the number of nozzles, the more efficient the formation of the functional element. However, this does not mean that simply increasing the number of liquid jet heads increases the cost of the liquid ejecting head and increases the probability of clogging of the ejecting nozzles. The balance is determined in consideration of the production efficiency of the conductive element.
[0063]
FIG. 8 shows a view of the multi-nozzle type liquid ejecting head manufactured in this way as viewed from the nozzle side. In the present invention, such a multi-nozzle type liquid ejecting head is provided for each solution to be ejected and mounted on a carriage as shown in FIG. FIG. 10 is a perspective view thereof.
[0064]
9 and 10, each of the multi-nozzle type liquid ejecting heads is denoted by A, B, C and D, but each of the liquid ejecting heads A, B, C and D has a nozzle portion corresponding to each liquid. A different type of conductive fine particle-containing solution or nanoparticle-containing solution can be ejected for each liquid ejecting head while being separated from each other.
[0065]
The present invention is to produce a functional device by spraying a solution containing conductive fine particles or a solution containing nanoparticles, but not only to spray a single solution, but also Since various types of solutions can be sprayed, for example, a device structure combining a solution for forming an electrode pattern and a solution for forming a functional device can be easily formed.
[0066]
Next, other features of the present invention will be described. As described above, in the present invention, a pattern wiring is formed or a functional device is formed. The solution used for the formation is a nanoparticle-containing solution. Then, the present invention relates to a technique for forming a pattern on a substrate by jetting the solution from a fine discharge port by a technique equivalent to the so-called inkjet jetting principle. However, in the inks conventionally used in the inkjet recording field, the dye is dissolved in the solution, whereas in the solution used in the present invention, the nanoparticles are only dispersed in the solution, so clogging occurs. Cheap.
[0067]
Furthermore, according to the present invention, in view of the required pattern or device application, an ejection head having an unprecedented minute ejection opening, for example, an ejection opening having a diameter of 20 μm or less (about 300 μm ² or less in terms of area). This clogging is a very serious problem.
[0068]
By the way, clogging is derived from the very principle that a solution is ejected from a fine discharge port. In other words, this is caused because the discharge port is fine. Therefore, there is a close relationship between the size of the discharge port and the size of the nanoparticles, which may be called foreign particles in the solution.
[0069]
In view of this point, the present invention pays attention to the size of the discharge port and the size of the nanoparticles, and finds out the relationship between the difficulty of clogging and their relationship. Specifically, a solution in which the nanoparticle diameter is changed is prepared, a droplet is ejected for a certain period of time using an ejection head whose ejection port is known, and then left for a certain period of time, and the droplet ejection is restarted. The discharge port was examined for clogging. In this case, not only the complete obstruction of the discharge port, but also partial clogging and the prior signs (slight clogging) leading to it were considered as clogging and tested.
[0070]
The used ejection head uses a piezo element as shown in FIGS. 5 and 6 as a driving force for discharging a droplet. That is, the mechanical displacement of the piezo element, which is an electro-mechanical conversion element, is used as the displacement of the diaphragm of the liquid chamber, and droplets are ejected from fine discharge ports by the displacement acting force.
Although not shown in the figure, an ejection head having a structure in which a nozzle plate having a nozzle hole separately provided on one surface of the nozzle was provided. The number of nozzles is shown as a simplified example of seven nozzles in the figure, but the number of nozzles (discharge ports) actually used is 64 and the arrangement density is 100 dpi. The driving voltage for droplet ejection was 20 V, and the driving frequency was 10 kHz. In addition, ejection heads H1 to H4 were prepared (the discharge port diameters were H1 = Φ20 μm, H2 = Φ15 μm, H3 = Φ10 μm, and H4 = Φ5 μm). The nozzle plate was formed by Ni electroforming, and the thickness of the discharge port portion was 25 μm.
[0071]
The solution used was produced as follows. That is, a water-soluble polymer was dissolved in silver nitrate, dimethylaminoethanol was added with stirring, and metal ions were reduced in 3 minutes to precipitate Ag fine particles having an average particle size of 0.5 μm (500 nm) or less. Thereafter, chlorine ions and nitrate ions were removed by an ultrafiltration membrane, and concentrated and dried to obtain a concentrated Ag fine particle-containing solution.
[0072]
Further, this Ag fine particle-containing solution was dissolved in acetone, and alkanolamine was added with further stirring to precipitate the Ag fine particles in a form dispersed in the polymer on the oil phase side. The concentrated Ag fine particle-containing solution which was concentrated and dried was dissolved and mixed in a mixed solvent of water, alcohol and ethylene glycol to obtain a jetting solution. In addition, in order to produce a solution in which the size of the Ag fine particles was changed, a centrifugal separator was used to prepare Ag fine particles having an average particle size of 0.0001 μm to 0.5 μm. However, those having an average particle diameter of 0.0003 μm or less were not produced, but could not be evaluated because they were not stable. The content of Ag fine particles in each solution was 10% by weight, and the resin content in the solutions was 20% by weight. The amount of ethylene glycol added was adjusted, and the viscosity of each solution was unified to 20 centipoise.
The test was performed by combining each solution having different Ag particle diameters with H1 to H4 having different ejection opening diameters, continuously performing droplet ejection for 10 minutes, and then allowing to stand for 10 hours in an atmosphere at a temperature of 40 ° C. and a humidity of 30%. Thereafter, the injection was restarted to check the occurrence of clogging. The results are shown in Tables 1 to 4.
[0073]
Table 1 shows the case of the head H1 (discharge port diameter Do = Φ20 μm), Table 2 shows the case of the head H2 (discharge port diameter Do = Φ15 μm), Table 3 shows the case of the head H3 (discharge port diameter Do = Φ10 μm), and Table 4 shows the head H4 (Discharge port diameter Do = Φ5 μm) is shown. In the judgment, a circle indicates a case where it can be practically used satisfactorily, a triangle indicates a case where it can be used but is not so preferable, and a cross indicates a case where it is not practical at all.
[0074]
[Table 1]

[0075]
[Table 2]

[0076]
[Table 3]

[0077]
[Table 4]

[0078]
From the above results, in the case where the ejection head having a discharge port diameter of Φ5 μm to Φ20 μm is used, clogging does not occur if the relationship between the Ag fine particle diameter Dp and the discharge port diameter Do satisfies the relationship Dp / Do ≦ 0.01. It can be seen that stable droplet ejection can be obtained. Although the lower limit of Dp / Do is considered, it is difficult to set the Ag fine particle diameter Dp to 0.0003 μm or less in consideration of such a very fine fine particle being stably dispersed in a solution. Further, in order to allow stable ejection of droplets to all ejection heads having an ejection diameter of 20 μm or less, the lower limit of Dp / Do may be set to 0.0001 with a margin. That is, if the relationship between the diameter Dp of the Ag fine particles and the diameter Do of the discharge port satisfies the relationship of 0.0001 ≦ Dp / Do ≦ 0.01, the pattern by the droplet discharge using the discharge head having the discharge diameter of Φ20 μm or less can be obtained. It can be seen that a stable dispersion liquid capable of forming or forming a device can be manufactured, and clogging of the discharge port (nozzle) can be prevented.
[0079]
In this experiment, a circular discharge port (nozzle) was used. However, in the case of another shape, the area may be compared. For example, in the case of a rectangular discharge port of 18 μm × 18 μm, the round shape of the present invention is used. It is almost equivalent to a Φ20 μm nozzle with a shape. In other words, the present invention provides a jet head using a nozzle having an area of about 300 μm ² or less, and a nozzle having a lower limit of about 20 μm ² (discharge port diameter of 5 μm). Alternatively, it is applied when forming a device.
[0080]
In the experiment, a jet head using a piezo element as a driving force for liquid droplet ejection was used. This is a common problem for the ejection head based on the principle that the fine particle-containing solution is ejected from the minute discharge port by utilizing the growth action force of the film boiling bubble generated in the ejection head. Can be applied as is.
[0081]
In addition, the method of generating film boiling bubbles using a thermal head or the like has a high density and high integration arrangement of the heating element portion and the discharge port portion due to its structure, and has an arrangement density of 600 dpi to 1200 dpi or more. In addition, the number of discharge ports (nozzles) of 500 to 10000 can be easily realized, which is suitable for a manufacturing apparatus with high production efficiency.
[0082]
Next, other features of the present invention will be described. As described above, in the present invention, the fine particle-containing solution is configured to eject stable droplets without causing clogging from the minute ejection port. The following shows the results of studying how to form a simple pattern or device.
[0083]
As described above, in the present invention, the ejection head unit 11 performs relative movement in the X and Y directions in parallel with the pattern or the formation surface of the functional device group while maintaining a certain distance with respect to the substrate 14. A pattern or a group of functional devices is formed. That is, the ejection head unit 11 moves parallel to the substrate surface with respect to the substrate 14, or the substrate 14 moves parallel to the ejection head unit 11.
[0084]
At this time, a high-precision pattern or a functional device group can be formed by stopping the relative movement each time the fine particle-containing solution for forming the pattern or the functional device group is ejected and performing the ejection. However, since the productivity is significantly reduced, the solution is sequentially sprayed without stopping the relative movement. In that case, the relative moving speed (for example, the moving speed of the carriage in the X direction in FIG. 2) should not be determined merely by improving the productivity, but also from the viewpoint of forming a highly accurate pattern or a functional device group. Must be considered.
[0085]
FIG. 11 shows the shape of the solution at the time of jetting and flying when the fine particle-containing solution is jetted from the fine discharge port using the growth action force of the film boiling bubble which is preferably used in the present invention. . FIG. 12 and FIG. 13 show the shape of the solution at the time of jetting and flying when the piezo element is used as a driving force for droplet ejection and jetted by a mechanical action force.
[0086]
The difference between FIG. 11 and FIGS. 12 and 13 is that, in the case of FIG. 11, a part of the solution is heated to 300 to 400 ° C. instantly (for several μs) to generate film boiling bubbles, and the instantaneous In order to eject the solution using the growth (for several μs) and the pressure rise (acting force), the piezo element is used as the driving force of the droplet discharge, and the ejection pressure is lower than when ejecting by the mechanical acting force. It is high and the injection speed is fast. As a result, as shown in FIG. 11, at the time of flight, the flight shape of the solution is elongated in the direction of flight in the form of an elongated column, and the solution is flying at a high speed with a plurality of fine droplets (satellite fine droplets 81) behind. ing.
[0087]
For example, the shape at the time of the flight of the solution is such that, when a stable film-boiling bubble is normally generated and caused to fly, the length l of the elongated columnar shape extending in the flight direction is at least 5 times the diameter d, and The flying speed is about 5 m / s to 20 m / s.
As a result, there is an advantage that the jetting is stable and the jetting accuracy of the jetted solution on the substrate is high.On the other hand, if the relative moving speed of the jetting head and the substrate is not appropriately selected, the jetting solution becomes an elongated column in the flight direction. The extended solution at the rear portion and a plurality of microdroplets (satellite microdroplets 81) connected to the rear portion may prevent good round dot formation.
[0088]
In the present invention, as a result of diligent studies on this point, it has been found that when jetting such a fine particle-containing solution, it is necessary to optimize the relationship between the jetting speed and the relative moving speed. . By the way, when the ejection head unit 11 is moved relative to the substrate 14 in the X and Y directions while keeping a constant distance, the solution containing fine particles is ejected to form a pattern or a functional device group. In this case, the solution is attached and formed on the substrate 14 at the speed of the combined vector of the relative speed and the jet speed. With respect to the positional accuracy, the solution is attached to the target position by appropriately selecting the ejection timing in consideration of the distance between the substrate 14 and the solution ejection port surface of the ejection head unit 11 and the speed of the composite vector. be able to.
[0089]
However, even if it is possible to adhere to the target position, if the relative speed is too fast, the attached solution flows on the substrate 14 by being dragged by the relative speed, and a good round dot shape is obtained. In other words, a good pattern or a group of functional devices cannot be formed. In addition, a plurality of microdroplets (satellite microdroplets) connected rearward are randomly attached to positions deviating from the positions where they should originally adhere, preventing good round dot formation and preventing the performance of functional devices. May cause degradation. The present invention has examined this point.
[0090]
The following is an example of the study results. In this example, by using the apparatus as shown in FIG. 2, the moving speed of the carriage 12 in the X direction and the jetting speed of the ejection head unit 11 are changed so that a good solution can be attached on the substrate 14 and a good pattern can be formed. It is checked whether it is.
[0091]
FIG. 14 shows an example of a pattern used for the test. Here, a solution containing Ag fine particles is sprayed to form a wiring pattern in which two rows of adjacent device electrodes (between the ITO transparent electrodes 82) are connected to dot patterns 83 of the solution, and the state of the pattern formation is shown. It was evaluated. For evaluation, the pattern after formation was observed under a microscope, and good / bad (不良 / ×) was determined. FIG. 14 (A) is good (○), and as shown in FIG. 14 (B), the individual dot patterns 83 do not have a good round shape, but have an oval shape. Those that deviate from the target position or come into contact with the next dot pattern are defective (x). Further, those in which minute droplets 84 caused by satellite minute droplets were scattered were also regarded as defective (x).
[0092]
Together with the evaluation of the shape, the resistance value between the upper and lower ITO transparent electrodes 82 was measured, and the disconnection due to poor dot position accuracy or the resistance value fluctuation due to contact with the adjacent (left and right) dots was evaluated (（). : Resistance value as aimed, ×: Resistance value out of aim).
[0093]
Details of the experimental conditions are shown below. The substrate used was a glass substrate provided with an ITO transparent electrode 82, and the above-mentioned Ag fine particle-containing solution (here, a fine particle having a particle size of 0.01 μm was used) was used as the jet head shown in FIG. 14 was formed in combination with the provided multi-nozzle plate formed by Ni electroforming. FIG. 14 shows a diagram in which the space between the pair of ITO transparent electrodes 82 is formed to be filled with four dots for simplicity. However, in actuality, dots of about Φ8 μm are vertically arranged in one row. Approximately 1000 are implanted at a pitch of about 4 μm to connect the upper and lower ITO transparent electrodes 82 (the distance between the electrodes is 4 mm). Further, with the center-to-center distance being 12 μm, a similar ITO transparent electrode 82 and a similar pattern connecting between the ITO transparent electrodes 82 are formed.
[0094]
The ejection head used was the above-described ejection head (FIG. 7 shows simplified four nozzles), but the number of nozzles (discharge ports) is 64. The array density is 400 dpi. The size of the heating element is 10 μm × 40 μm, and its resistance value is 102Ω. The driving speed of the head was changed from 10 to 11 V to change the ejection speed, the pulse width was 2 μs, and the driving frequency was 14 kHz.
[0095]
Under such conditions, the above-described pattern (FIG. 14) is formed on a glass substrate, and the formed pattern is evaluated. Under the same conditions, a separate injection experiment is performed to obtain a solution 3 mm away from the discharge port. Was observed. This is because the test pattern of FIG. 14 was manufactured with the distance between the substrate and the discharge port being 3 mm. As shown in FIG. 11, the flight form was a column (1 = 5d to 20d) that was very elongated in the flight direction. In addition, the state was such that a plurality of minute droplets (satellite minute droplets 81) were accompanied behind the flying droplet. The examination results are shown in Table 5 below.
[0096]
[Table 5]

[0097]
From the above results, it can be seen that when the moving speed of the carriage in the X direction exceeds １ ／ of the ejection speed, a good element cannot be formed. This example is an example in which the ejection head is scanned by the carriage, but is also applicable to a case where the ejection head is fixed and the substrate is moved as shown in FIG. That is, the relative movement speed between the ejection head and the substrate must be equal to or less than 1/3 of the speed of the solution to be ejected.
[0098]
As is clear from the above description, the present invention is a technology for manufacturing a pattern wiring substrate or a device substrate, but not using a very fine pattern of several tens μm to several μm by a photolithography technology as in the related art. Patterns and devices are directly manufactured by a simple device in which droplets of a solution containing fine particles are directly applied to a substrate by an ejection head having a minute ejection port which has not been conventionally provided. Therefore, expensive manufacturing equipment used in a so-called semiconductor manufacturing process is not required, and the semiconductor device can be manufactured stably at low cost.
[0099]
【The invention's effect】
In a solution jet manufacturing apparatus for manufacturing a pattern wiring substrate or a device substrate, a droplet of a solution containing fine particles is jetted by a jet head having a discharge diameter of Φ20 μm or less by the action of growing a film-boiling bubble. By optimizing the aperture and realizing stable jetting without clogging, it has become possible to manufacture high-precision and high-quality pattern wiring boards or device substrates by a novel method at low cost. In addition, since the relative movement speed between the substrate and the ejection head is set to 1/3 or less of the ejection speed of the solution, a high-precision and high-quality pattern wiring board or device substrate can be manufactured at a low cost by a novel method. became.
[0100]
In addition to the above-described effects, the jetting and flying conditions are such that the jetting and flying can be performed at high speed to achieve high impact accuracy, so that a high-precision and high-quality pattern wiring board or device substrate can be manufactured at a low cost by a novel method. It became so.
[0101]
Since it is a pattern wiring board or device substrate manufactured by the above-described novel configuration of the droplet jet manufacturing apparatus, a high-precision, high-quality, low-cost pattern wiring board or device substrate can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an embodiment of a pattern wiring formed by a solution jet manufacturing apparatus of the present invention.
FIG. 2 is a view for explaining an embodiment of a solution jet manufacturing apparatus for manufacturing a pattern wiring substrate or a device substrate according to the present invention.
FIG. 3 is a view for explaining another embodiment of the solution jet manufacturing apparatus for manufacturing a pattern wiring substrate or a device substrate according to the present invention.
FIG. 4 is a schematic configuration diagram showing a solution applying apparatus applied to the manufacture of a pattern wiring substrate or a device substrate according to the present invention.
FIG. 5 is a view for explaining the principle of droplet ejection of an ejection head utilizing a piezo element which is suitably used in the present invention.
FIG. 6 is a view showing the structure of a jet head utilizing a piezo element which is suitably used in the present invention.
FIG. 7 is an example of a thermal (bubble) liquid ejection head suitably applied to the present invention.
FIG. 8 is a view of the multi-nozzle type liquid ejecting head as viewed from the nozzle side.
FIG. 9 is a view in which a multi-nozzle type liquid ejecting head is stacked and unitized for each solution to be ejected.
FIG. 10 is a perspective view of the head unitized as described above.
FIG. 11 is a diagram for explaining an example of a solution flying shape when the ejection head used in the solution ejection manufacturing apparatus of the present invention ejects with the action force of film boiling bubbles.
FIG. 12 is a view for explaining an example of a droplet flying shape in a case where the ejection head used in the solution ejection manufacturing apparatus of the present invention ejects with an acting force due to mechanical displacement.
FIG. 13 is a diagram for explaining another example of a droplet flying shape when the ejection head used in the solution ejection manufacturing apparatus according to the present invention ejects the droplet by an action force due to mechanical displacement.
FIG. 14 is a diagram showing an example of a test pattern used for finding conditions for forming a good pattern by the solution jet manufacturing apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wiring pattern, 2, 3 ... Terminal, 10 ... Substrate, 11 ... Discharge head unit (ejection head), 12 ... Carriage, 13 ... Substrate holding stand, 14 ... Substrate, 15 ... Supply tube of solution containing fine particles, 16 ... Signal supply cable, 17: injection head control box, 18: X direction scan motor, 19: Y direction scan motor, 20: computer, 21: control box, 22: substrate positioning / holding means, 31: head alignment control mechanism, 32 ... Detection optical system, 33 ejection head, 34 head alignment fine movement mechanism, 35 control computer, 36 image identification mechanism, 37 XY direction scanning mechanism, 38 position detection mechanism, 39 position correction control mechanism, 40 ... Ink jet head drive / control mechanism, 41. Optical axis, 42. Element electrode, 43. ... droplet landing position, 45 ... flow path, 46 ... piezo element, 47 ... solution, 48 ... (liquid jet head) nozzle, 49 ... filter, 65 ... nozzle, 66 ... heating element substrate, 67 ... cover substrate, 68 ... Silicon substrate, 69 individual electrode, 70 common electrode, 71 heating element, 74 groove, 75 concave area, 76 solution inlet, 81 satellite fine droplet, 82 element electrode (ITO transparent electrode), 83 ... Dot pattern, 84.

Claims (4)

A fine particle-containing solution was jetted onto the substrate by a jetting head having a discharge port diameter of Φ20 μm or less to form a pattern in which the energized region on the substrate was contacted so as to cover from above, and formed by the applied solution. In a solution jet manufacturing apparatus for forming a pattern wiring or a device by volatilizing a volatile component in a pattern and leaving a solid content on the substrate and the energized region, the size of the fine particles is set to Dp, and the discharge port diameter is set to When Do, 0.0001 ≦ Dp / Do ≦ 0.01, and the jetting head jets the solution by the growth action of film boiling bubbles instantaneously generated in the solution, Is formed into a long and narrow columnar shape extending in the flight direction and having a length of 5 times or more the diameter thereof, and the relative moving speed between the substrate and the ejection head is determined by the melting speed. The solution injector manufacturing apparatus characterized in that the one-third or less of the jet velocity. 2. The solution jet manufacturing apparatus according to claim 1, wherein the elongated column-shaped solution at the time of flying is made to fly at a high speed with a plurality of fine droplets rearward. 3. A pattern wiring board formed by the solution jet manufacturing apparatus according to claim 1. A device substrate formed by the solution jet manufacturing apparatus according to claim 1.

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