JP3680855B2 - Electrostatically attracting droplet nozzle and method for producing the same - Google Patents

Description

  The present invention relates to an electrostatic attraction type droplet nozzle and a manufacturing method thereof, more specifically, electrostatic attraction type that is mounted on an ink jet droplet discharge device by electrostatic force, and discharge liquid is discharged from a liquid discharge port at the tip of a liquid flow path. The present invention relates to a droplet nozzle and a manufacturing method thereof.

  In recent years, in the fields of flat panel displays and computer-related devices, there has been a demand for simplification of manufacturing apparatuses, expansion of manufacturing freedom, and resource saving. In response to this, a method for producing an organic EL display by directly ejecting an organic EL (Electro Luminescence) material onto a silicon substrate using an ink jet nozzle that ejects droplets, and a solution containing conductive particles are printed. A method of directly drawing a wiring pattern by discharging onto a circuit board or the like has been studied.

As conventional ink jet nozzles that perform such direct drawing, for example, piezoelectric droplet nozzles using piezo elements, thermal droplet nozzles using droplet film boiling, and the like are known.
When both types of nozzles are used, clogging of the discharge liquid tends to occur at the discharge port of the liquid flow path. Accordingly, the nozzle diameter is restricted, and the minimum diameter of the ejected droplet (hereinafter referred to as the minimum droplet diameter) is limited to 20 μm.

Therefore, as a conventional ink jet type nozzle for solving this problem, an electrostatic attraction type nozzle as described in Patent Document 1 , for example, is known.
Hereinafter, a conventional electrostatic attraction type droplet nozzle will be described in detail with reference to FIGS.
As shown in FIGS. 28 and 29, a conventional electrostatic attraction-type droplet nozzle 100 includes a nozzle body 101 and a liquid channel 102 formed inside the nozzle body 101 and through which ink (discharge liquid) passes. , A pair of discharge electrodes 103 disposed on both sides of the liquid flow path 102, a covering member 104 that covers both discharge electrodes 103, and a sharp tip disposed in the liquid flow path 102, A discharge member 106 having a flat needle shape (hereinafter referred to as a needle plate shape) protruding outward from the liquid discharge port 105 at the tip, and an auxiliary member 107 made of an insulating material for fixing the discharge member 106 to the liquid flow path 102 And a grid electrode (gate electrode) 109 which is disposed at a position spaced apart from the liquid discharge port 105 and has an opening 108 through which the discharged ink passes.
Further, a bias power source 112 and a pulse power source 113 are connected to both ejection electrodes 103, respectively. Further, a flat counter electrode 110 facing the electrostatic attraction type droplet nozzle 100 is disposed at a predetermined position in the liquid discharge direction separated from the opening 108.
For example, a silicon substrate 111 for an organic EL display is in contact with the surface of the counter electrode 110 on the electrostatic attraction type droplet nozzle 100 side (hereinafter referred to as a nozzle side surface). The counter electrode 110 is connected to a droplet acceleration power source 114.

In the electrostatic attraction type droplet nozzle 100, first, a silicon substrate 111 for an organic EL display is disposed on the nozzle side surface of the counter electrode 110 with the back surface thereof as a contact surface.
Further, the surface of the liquid flow path 102 is wetted with ink supplied from an ink tank (not shown). Thereafter, a bias voltage of 1.5 to 2.0 kV is applied to the ejection electrode 103. Then, an electric field directed to the liquid discharge port 105 acts on the fine particles of the organic EL material contained in the ink in the liquid flow path 102.
As a result, the fine particles gradually concentrate while flowing in the direction of the liquid discharge port 105 along the discharge member 106 having a needle plate shape, and form droplets near the liquid discharge port 105. At this time, electrostatic repulsive force acts on the fine particles in the droplet, and the fine particles try to jump out toward the counter electrode 110.

However, the electrostatic repulsion force due to the bias voltage is set in advance smaller than the surface tension of the ink. Therefore, the fine particles cannot jump out from the surface of the droplet.
In this state, a pulse voltage of about 300 to 500 V is superimposed on the bias voltage according to the discharge amount of the fine particles.
As a result, the electrostatic repulsion force exceeds the surface tension of the liquid droplets, and the fine particles are discharged from the liquid discharge port 105 and fly toward the counter electrode 110 through the opening 108 of the grid electrode 109. At this time, when a voltage having a higher potential than the counter electrode 110 is applied to the grid electrode 109, the fine particles are subjected to a force due to an electric field between the grid electrode 109 and the counter electrode 110.
Thereby, the discharge of fine particles can be stabilized.
JP 2000-255066 A

However, in the conventional electrostatic attraction type droplet nozzle 100, the width of the ejection member 106 having a plate needle shape is as large as 140 μm, and the curvature radius of the tip of the ejection member 106 is as large as 10 μm.
As a result, it has been difficult to reduce the minimum ink droplet diameter to 1 μm or less that allows direct drawing on an organic EL display.
Further, in the conventional electrostatic attraction type droplet nozzle 100, since the electric field acting on the tip of the nozzle is small, a high voltage is required to eject droplets (fine particles).

In order to solve this problem, for example, dry etching, which is a kind of semiconductor microfabrication such as reactive ion etching (RIE), is applied to the silicon substrate from the surface side in the thickness direction of the substrate. It is conceivable to perform dry etching toward the surface.
However, the depth of dry etching that pierces a silicon substrate with a hole-shaped liquid flow path is as deep as several hundred μm, for example. The aspect ratio of the silicon substrate by dry etching such as RIE is about R10 to R100.
For this reason, bowing as an etching defect is likely to occur in the liquid flow path.
Boeing is a state in which etching in the lateral direction proceeds in the middle of forming the liquid flow path, and the side wall of the liquid flow path has a concave cross section.
Thereby, it was difficult to produce a liquid channel having a constant cross-sectional area over the entire length of the channel. As a result, a droplet having a minimum droplet diameter of 1 μm or less could not be discharged.

An object of the present invention is to provide an electrostatically attractive droplet nozzle capable of discharging a discharge liquid having a minimum droplet diameter of 1 μm or less and capable of being driven by a low voltage, and a manufacturing method thereof. .
Another object of the present invention is to provide an electrostatically attracting droplet nozzle capable of stabilizing droplet ejection and a method for manufacturing the same.

The electrostatic attraction type droplet nozzle shown as a reference example has a liquid flow path through which the discharge liquid passes in the nozzle body, and an electrostatic force generated by applying a voltage to the discharge electrode arranged in the liquid flow path. Accordingly, the nozzle body has a first substrate and a second substrate bonded to the first substrate, in which the discharge liquid is discharged from the liquid discharge port at the tip of the liquid flow path. A liquid channel groove constituting a part of the liquid channel is formed by dry etching on the surface of at least one of the first substrate and the second substrate on the bonding side.

According to this electrostatic attraction type droplet nozzle, when the nozzle body is formed by bonding the first substrate and the second substrate, the liquid flow formed by dry etching between the bonding surfaces of both substrates is formed. A liquid flow path is formed mainly using the channel groove.
In this case, when the groove for liquid flow path is dry-etched on the bonded surface of the selected substrate, the etching direction is not directed in the length direction of the groove but in the width direction of the groove. As a result, the etching amount is reduced.
Therefore, even in dry etching with an aspect ratio of R10 to R100, bowing is unlikely to occur in the liquid flow path. This makes it possible to produce a liquid flow path having a constant cross-sectional area over the entire length of the flow path using semiconductor microfabrication.
As a result, it is possible to discharge a droplet of a discharge liquid having a minimum droplet diameter of 1 μm or less, and an ink jet droplet discharge apparatus having an electrostatic attraction type droplet nozzle even at a lower voltage than in the past. Can be driven.

The method of the electrostatic attraction type droplet nozzle is not limited. For example, a permanent flow type that continuously discharges the discharge liquid may be used. Further, a drop-on-demand type that discharges a required amount of liquid when necessary may be used.
As the material of the nozzle body, for example, single crystal silicon, polycrystalline silicon, glass or the like can be employed. In short, if the substrate on which at least the liquid channel groove is formed is a material that can be finely processed among the first substrate and the second substrate by dry etching, which is a kind of semiconductor microfabrication method. Good.
The first substrate and the second substrate constituting the nozzle body may be the same material. Different materials may be used.
As the shape of the nozzle body, for example, a rectangular shape, a circular shape, an elliptical shape, or the like can be adopted in plan view.

The discharge liquid is obtained by adding a predetermined amount of fine particles to a predetermined solvent. As the solvent, for example, oil, water, organic solvent and the like can be employed.
As the fine particle material, for example, various organic EL materials, various pigments, various conductive materials and the like can be employed.
The particle diameter of the fine particles is 1 to 200 nm, preferably 10 to 50 nm. If it is less than 1 nm, it is difficult to produce fine particles.
In addition, when the thickness exceeds 200 nm, it is difficult to control the droplets, and there are problems such as a large volume change when the solvent is removed. The amount of fine particles added is, for example, 10 to 1000 parts by weight.

As the cross-sectional shape of the liquid channel, for example, a circle, an ellipse, a triangle, a polygon more than a quadrangle, and the like can be adopted.
The width of the liquid channel is 0.5 to 50 μm, preferably 0.5 to 5 μm.
If the thickness is less than 0.5 μm, processing becomes difficult and liquid clogging tends to occur. On the other hand, if it exceeds 50 μm, it is difficult to precisely control the droplets. The length of the liquid channel is not limited.
For example, PolySi, MoSi ₂ , WSi, TiSi ₂ , W, or the like can be used as the material of the discharge electrode.
The electrostatic attraction type droplet nozzle is mounted on an ink jet type droplet discharge device, and applies a voltage between the discharge electrode and a counter electrode having a flat plate shape so that droplets (fine particles) of the discharge liquid are opposed to each other. For example, it can be discharged onto the surface of a silicon substrate disposed on the electrode side.

The liquid channel groove may be formed on the bonding surface of the first substrate. Alternatively, it may be formed on the bonding surface of the second substrate.
Furthermore, you may form in the bonding surface of both board | substrates.
As the cross-sectional shape of the liquid channel groove, for example, a circular shape, an elliptical shape, a triangular shape, or a polygonal shape having a square shape or more can be adopted.
Dry etching is a kind of semiconductor microfabrication technology, and a predetermined etching gas is used to form a liquid flow channel groove on a bonded surface of selected substrates.

In the electrostatic attraction type droplet nozzle, the discharge electrode is a needle-like electrode having a tip formed at an acute angle protruding from the liquid discharge port.

According to this electrostatic attraction type droplet nozzle, a needle-like electrode having a sharp tip is adopted as the discharge electrode, so that the fine particles contained in the discharge liquid are moved to the liquid discharge port side in the liquid flow path by the electrostatic force. When flowing, the fine particles are gradually concentrated along the sharp tip of the discharge electrode, while concentrating on the fine tip of the discharge electrode to form droplets.
As a result, it is possible to drive an ink jet type droplet discharge device in which an electrostatically attractive droplet nozzle is incorporated even at a lower voltage.

The angle of the sharp tip of the discharge electrode is, for example, 10 to 50 degrees.
The discharge electrode, which is a needle electrode, has a diameter of 0.1 to 40 μm, preferably 0.1 to 3 μm.
If it is less than 0.1 μm, processing becomes difficult. On the other hand, if it exceeds 40 μm, it becomes difficult to precisely control the droplets.
The tip electrode has a radius of curvature of 10 to 500 nm, preferably 10 to 100 nm.
If the thickness is less than 10 nm, the processing becomes difficult, and the electrostatic force tends to cause breakage.
Further, when the thickness exceeds 500 nm, a high voltage is required, and there is a problem that it is difficult to precisely control droplets.

Further, in the electrostatic attraction type droplet nozzle, the formation portion of the liquid discharge port is provided at a predetermined position in the liquid discharge direction separated from the liquid discharge port via an insulating electrode holder. A gate electrode is projected, and an opening through which the discharged discharge liquid passes is formed in the gate electrode .

Further , according to the electrostatic attraction type droplet nozzle, the fine particles discharged from the liquid discharge port fly through the opening of the gate electrode and then fly toward the counter electrode arranged at a predetermined position in the liquid discharge direction. To do.
At this time, when a voltage having a higher potential than that of the counter electrode is applied to the gate electrode, the fine particles in the ejected droplet are also subjected to a force by an electric field between the gate electrode and the counter electrode.
Thereby, the discharge of the discharge liquid (fine particles) can be stabilized.

The distance between the electrode holder and the liquid discharge port is not limited. For example, it is 1-20 micrometers.
As a material for the electrode holder, for example, silicon oxide, polyimide, silicon nitride, or the like can be used.
The thickness of the electrode holder is, for example, 1 to 10 μm.
As a material for the gate electrode, for example, PolySi, MoSi ₂ , TiSi ₂ , W, or the like can be employed.
As a method for forming the gate electrode, for example, a CVD (Chemical Vapor Deposition) method, a sputtering method, or the like can be employed.
As the shape of the opening, for example, a circular shape, an elliptical shape, a triangular shape, or a polygon shape that is equal to or larger than a quadrangle in a plan view can be adopted.
The size of the opening is, for example, 1 to 20 μm in diameter.

In this method of manufacturing an electrostatic attraction type droplet nozzle, a discharge electrode is disposed in a liquid flow path formed in the nozzle body and through which the discharge liquid passes, and an electrostatic force generated by applying a voltage to the discharge electrode. Thus, in the method of manufacturing an electrostatic attraction type droplet nozzle in which the discharge liquid is discharged from the liquid discharge port at the tip of the liquid flow path, at least one of the first substrate and the second substrate to be bonded to each other A groove forming step of forming, by dry etching, a liquid channel groove constituting a part of the liquid channel on the bonding side surface of the substrate; and after forming the groove, the first substrate and the second substrate Among them, a discharge electrode forming step for forming the discharge electrode on at least one substrate, and after forming the discharge electrode, the first substrate and the second substrate are bonded together to form a nozzle body, and at the same time, the liquid flow Form a liquid flow path including a channel groove And a bonding step.

According to this manufacturing method, when the nozzle body is formed by bonding the first substrate and the second substrate, the liquid channel groove formed by dry etching is mainly formed between the bonding surfaces of the two substrates. Forming a liquid flow path.
In this case, when the groove for liquid flow path is dry-etched on the bonded surface of the selected substrate, the etching direction is not directed in the length direction of the groove but in the width direction of the groove.
As a result, the etching amount is reduced. Therefore, even in dry etching with an aspect ratio of R10 to R100, bowing is unlikely to occur in the liquid flow path.
This makes it possible to produce a liquid flow path having a constant cross-sectional area over the entire length of the flow path using semiconductor microfabrication.
As a result, it is possible to discharge a droplet of a discharge liquid having a minimum droplet diameter of 1 μm or less, and an ink jet droplet discharge apparatus having an electrostatic attraction type droplet nozzle even at a lower voltage than in the past. Can be driven.

A method for attaching the first substrate and the second substrate is not limited. For example, when both substrates are made of the same silicon material, both substrates can be integrated by simply superimposing each other's bonding surfaces by van der Waals force.
Further, when the two substrates are made of different materials, the two substrates can be bonded together by, for example, anodic bonding. After bonding, in order to increase the bonding strength, a bonding heat treatment may be performed.
The type of dry etching is not limited. For example, RIE, plasma etching, ECR (Electron Cyclotron Resonance) etching, ion beam etching, photoexcited etching, or the like can be employed.
As a method for forming the discharge electrode, for example, a CVD method, a sputtering method, or the like can be employed.

According to the first aspect of the present invention , a liquid flow path through which the discharge liquid passes is formed in the nozzle body, and the discharge force is generated by an electrostatic force generated when a voltage is applied to the discharge electrode disposed in the liquid flow path. In the electrostatic attraction type droplet nozzle in which the liquid is discharged from the liquid discharge port at the tip of the liquid flow path, the discharge electrode is produced by anodization having a chip body and a needle portion protruding from the surface of the chip body. In the emitter tip thus formed, the needle portion is accommodated in the liquid flow path with the needle tip protruding from the liquid discharge port, and the tip end portion of the liquid flow path extends along the outer periphery of the needle portion. In other words, the electrostatically attractive droplet nozzle is gradually tapered.

Furthermore, according to the electrostatic attraction type droplet nozzle according to claim 1, when a voltage is applied to the emitter tip that is the ejection electrode, the fine particles contained in the ejection liquid in the liquid channel are applied to the needle portion of the emitter tip. Along the liquid discharge port side.
At this time, the tip portion of the liquid flow path is gradually tapered along the outer periphery of the fine needle portion (for example, 2 μm in diameter and the radius of curvature of the nozzle tip 200 nm) of the emitter chip obtained by anodization.
Thereby, a discharge liquid having a minimum droplet diameter of 1 μm or less can be discharged from the discharge port.
Moreover, it is possible to drive an ink jet type droplet discharge device incorporating an electrostatically attractive droplet nozzle even at a low voltage.

The material of the emitter tip is silicon. The tip body and the needle portion are integrally formed.
The vertical and horizontal dimensions of the chip body are not limited. For example, it is a square having a side of 5 to 50 μm. The thickness of the chip body is, for example, 0.1 to 5 μm.
The length of the needle part is, for example, 1 to 50 μm.
The diameter of the needle part is 0.1 to 10 μm, preferably around 1 μm.
If it is less than 0.1 μm, the mechanical strength is weakened and the life is shortened. On the other hand, if it exceeds 10 μm, it is difficult to reduce the diameter of the needle tip.
The diameter of the needle tip is 10 to 200 nm, preferably around 50 nm. If it is less than 10 nm, breakage easily occurs due to liquid discharge.
In addition, if it exceeds 200 nm, a high voltage is required, and there is a disadvantage that it is difficult to precisely control droplets. Details of the anodization will be described later.

The length of the needle tip protruding from the liquid discharge port is, for example, 1 to 50 μm.
The gap between the liquid discharge port and the peripheral side surface of the needle portion is 0.1 to 5 μm, preferably 0.1 to 1 μm.
If it is less than 0.1 μm, clogging of the liquid tends to occur. On the other hand, if it exceeds 1 μm, precise control of the droplets becomes difficult.

According to a second aspect of the present invention, a gate electrode protrudes from the liquid discharge port forming portion at a predetermined position in the liquid discharge direction separated from the liquid discharge port via an insulating electrode holder. The electrostatic attraction type droplet nozzle according to claim 1 , wherein the gate electrode is formed with an opening through which the discharged discharged liquid passes.

According to the electrostatic attraction type droplet nozzle according to claim 2, the fine particles discharged from the liquid discharge port pass through the opening of the gate electrode and then are applied to the counter electrode arranged at a predetermined position in the liquid discharge direction. Fly towards.
At this time, when a voltage having a higher potential than that of the counter electrode is applied to the gate electrode, the fine particles in the ejected droplet are also subjected to a force by an electric field between the gate electrode and the counter electrode.
Thereby, the discharge of the discharge liquid (fine particles) can be stabilized.

According to a third aspect of the present invention, the nozzle main body has a liquid flow path through which the discharge liquid passes, and the discharge liquid is generated by electrostatic force generated by application to the discharge electrode disposed in the liquid flow path. In a method for manufacturing an electrostatically attracting droplet nozzle that is discharged from a liquid discharge port at the tip of a liquid flow path, p-type silicon in which an n-type silicon region is formed on a part of a contact surface side with a hydrofluoric acid solution A discharge electrode manufacturing step of performing anodization on the substrate and manufacturing a discharge electrode composed of an emitter chip mainly having the n-type silicon region and having a chip body and a needle portion protruding from the surface of the chip body; An electrode bonding step of bonding the discharge electrode to the nozzle body with a surface opposite to the needle part as a bonding surface, and including the discharge electrode on the discharge electrode bonding side of the nozzle body Insulating film formation to form an insulating film And an outer wall forming step of forming a liquid channel outer wall film, which is an outer wall of the liquid channel, on the opposite side of the insulating film from the nozzle body, a raised portion of the insulating film covering the needle part, and a liquid Removing each tip of the raised portion of the flow path outer wall film, exposing the needle tip of the needle part, and forming the liquid discharge port; and after forming the liquid discharge port, It is a manufacturing method of the electrostatic attraction-type droplet nozzle provided with the liquid flow path formation process which removes a part including the said protruding part among the said insulating films, and forms the said liquid flow path.

According to the manufacturing method of the electrostatic attraction type droplet nozzle according to claim 3, when a voltage is applied to the emitter tip that is the discharge electrode, the fine particles contained in the discharge liquid in the liquid flow path become the needle portion of the emitter tip. Along the liquid discharge port side.
At this time, the tip portion of the liquid flow path is gradually tapered along the outer periphery of the fine needle portion (for example, 2 μm in diameter and the radius of curvature of the nozzle tip 200 nm) of the emitter chip obtained by anodization.
Thereby, a discharge liquid having a minimum droplet diameter of 1 μm or less can be discharged from the discharge port. Moreover, it is possible to drive an ink jet type droplet discharge device incorporating an electrostatically attractive droplet nozzle even at a low voltage.

As a method for manufacturing the emitter tip, for example, an anodizing method can be employed.
Anodizing is an etching performed under conditions of low current density in electrolytic etching using a silicon substrate as an anode in a hydrofluoric acid solution, and the silicon substrate is partially removed to form a porous layer.
In this anodization, since a silicon substrate is used as an anode and a potential barrier exists at the interface between the hydrofluoric acid solution and the silicon substrate, a p-type silicon substrate exhibits a forward-biased Schottky characteristic. Show.
On the other hand, an n-type silicon substrate exhibits a Schottky characteristic biased in the reverse direction. Porous silicon is formed under conditions of low current density.

In concrete emitter chip manufacture, a part of the back surface of a p-type single crystal silicon substrate is processed into a mesa shape by, for example, RIE.
Thereafter, phosphorus (P) ions are implanted into this mesa type region to form an n type region.
Next, the silicon substrate is mounted on the opened bottom surface of the anodizing tank containing the HF solution (hydrofluoric acid concentration of 25 to 49%), and the lid is fixed.
Then, a cathode electrode is inserted under the liquid surface of the HF solution, and an anode electrode is connected to the n-type region on the back surface of the silicon substrate.
Thereafter, current is passed between the electrodes at a current density of 5 to 50 mA / cm ² for 10 to 400 minutes.
As a result, the p-type silicon region (cathode side) of the silicon substrate becomes porous, while the n-type region on the anode side does not become porous.
As a result, a triangular pyramid-like or needle-like emitter tip is formed in one zone of the n-type region that is not made porous.

The material of the nozzle body is preferably the same silicon-based material as the emitter tip.
By van der Waal force, both members can be integrated by simply overlapping the emitter tip with the nozzle body.
Before bonding, it is preferable that the nozzle body is subjected to hydrophilic treatment.
Specifically, after RCA cleaning, the nozzle body is etched with a hydrofluoric acid solution (hydrofluoric acid concentration 1 to 10%) for 1 to 5 minutes to remove the natural oxide film on the surface. Then, the nozzle body is immersed in pure water for 5 to 10 minutes.
After bonding, the film is dried for 10 to 60 minutes in the atmosphere with a humidity of 40 to 60%. Then, heat treatment for enhancing the bonding strength and oxidizing the porous silicon layer is performed, for example, at 1000 ° C. for 2 hours in an oxygen atmosphere.
Next, the oxidized porous silicon layer is etched with an etchant of HF: H ₂ O ₂ = 1: 5, and the emitter chip integrated with the nozzle body is taken out.

As the insulating film used in the insulating film forming step, for example, a silicon oxide film or the like can be employed. The thickness of the insulating film is arbitrary. As a method for forming the insulating film, for example, a CVD method or a sputtering method can be employed.
As the liquid flow path outer wall film, for example, a silicon nitride film, WSi ₂ , Ta, or the like can be employed. The thickness of the liquid channel outer wall film is, for example, 0.5 to 2 μm. As a method for forming the liquid channel outer wall film, for example, a CVD method or a sputtering method can be employed.

The method of removing the tip of each raised portion of the insulating film and the liquid channel outer wall film is not limited.
For example, dry etching such as RIE or plasma etching can be employed. In addition, chemical mechanical polishing may be used.
The length of the needle tip portion of the needle portion exposed by this removal is, for example, 0.1 to 1 μm.
The diameter of the liquid discharge port is 0.1 to 5 μm, preferably 0.2 to 2 μm.
If it is less than 0.1 μm, liquid clogging is likely to occur. On the other hand, if it exceeds 2 μm, precise control of the droplets becomes difficult.
The method of forming a liquid flow path by removing a part including the raised portion of the insulating film is not limited. For example, wet etching according to the material of the insulating film can be employed. For example, when the insulating film is silicon oxide, etching using an HF solution is performed.

The invention according to claim 4 is the method of manufacturing an electrostatic attraction type droplet nozzle according to claim 3 , wherein the nozzle body is a silicon substrate.
As the silicon substrate, for example, a single crystal silicon substrate, a single crystal silicon substrate on which a silicon oxide film is formed, or the like can be employed.

The invention described in claim 5, wherein the insulating film is a silicon oxide film, in the liquid flow path forming step, the electrostatic described a portion of the insulating film in claim 3 or claim 4 is etched by hydrofluoric acid solution It is a manufacturing method of an attractive droplet nozzle.
For example, a hydrofluoric acid solution having a hydrofluoric acid concentration of 10 to 49% is used.

According to a sixth aspect of the present invention, in the liquid discharge port forming step, a resist film having a thickness in which at least the needle portion is buried is formed on the opposite side of the liquid channel outer wall film from the nozzle body, The method of manufacturing an electrostatically attractive droplet nozzle according to any one of claims 3 to 5 , wherein the surface layer of the resist film is dry-etched together with the tip portions of both raised portions.
At least the thickness of the resist film in which the needle part is buried is the sum of the insulating film thickness, the liquid channel outer wall film thickness, and the resist film thickness, with the bonding surface of the discharge electrode of the nozzle body as the reference plane. It means that the obtained value is larger than the height of the needle part.
As the dry etching, for example, RIE can be employed.

According to the seventh aspect of the present invention, an insulating layer and a conductive layer are sequentially formed on the opposite side of the liquid channel outer wall film to the liquid channel, and the liquid discharge port and the opposite portion of the conductive layer A gate electrode is formed by etching an opening through which the discharge liquid discharged from the liquid discharge port passes, and then the opening is formed in a portion of the insulating layer facing the opening. 7. The method of manufacturing an electrostatically attractive droplet nozzle according to any one of claims 3 to 6, wherein an electrode holder is formed by etching an internal space communicating with the liquid discharge port.

This insulating layer is a layer in which a liquid flow path is formed.
As a material for the insulating layer, for example, silicon oxide, silicon nitride, polyimide, or the like can be employed.
The thickness of the insulating layer is 1 to 50 μm, preferably 5 to 20 μm. If it is less than 1 μm, the flow path is likely to be clogged.
Moreover, when it exceeds 50 micrometers, the problem that manufacture becomes difficult will arise.
As a material for the conductive layer (gate electrode), PolySi, MoSi ₂ , TiSi ₂ , W, or the like can be employed.
As a method for forming the insulating layer and the conductive layer, for example, a CVD method, a sputtering method, or the like can be employed.

The size of the opening formed in the conductive layer may be larger than the opposing liquid discharge port.
As the shape of the opening, for example, a circle, an ellipse, a polygon more than a triangle can be adopted.
The etching solution for the conductive layer is appropriately selected according to the material of the conductive layer.
The insulating layer is a layer on which the electrode holder is formed. The shape and size of the internal space are substantially the same as the shape and size of the opening.
The etching solution for the insulating layer is appropriately selected according to the material of the insulating layer.

According to an eighth aspect of the present invention, the nozzle body has a liquid flow path through which the discharge liquid passes, and the discharge liquid is generated by electrostatic force generated by application to the discharge electrode disposed in the liquid flow path. In a method for manufacturing an electrostatically attracting droplet nozzle that is discharged from a liquid discharge port at the tip of a liquid flow path, p-type silicon in which an n-type silicon region is formed on a part of the contact surface with a hydrofluoric acid solution A discharge electrode manufacturing step of performing anodization on the substrate and manufacturing a discharge electrode composed of an emitter chip mainly having the n-type silicon region and having a chip body and a needle portion protruding from the surface of the chip body; An electrode bonding step of bonding the discharge electrode to the nozzle body using a surface opposite to the needle portion as a bonding surface; and an elastomer layer forming step of forming an organic elastomer layer on a flat surface of the dummy substrate; The organic ester A through-hole forming step of forming a through-hole through which the discharge electrode can be inserted with ease through the front and back surfaces of the steamer layer; and inserting the discharge electrode into the through-hole, It is a manufacturing method of an electrostatic attraction type droplet nozzle provided with the elastomer pasting process which pastes an organic elastomer layer on the surface.

According to invention of Claim 8, the organic elastomer layer which used the organic elastomer as a forming material is formed in a nozzle main body, and a liquid flow path is produced in this organic elastomer layer.
Thereby, a liquid flow path can be produced easily and with high accuracy.

As the dummy substrate, for example, a silicon (single crystal or polycrystal) substrate, a glass substrate, an acrylic substrate, a vinyl chloride substrate, a metal substrate, or the like can be employed.
As the elastomer, for example, SYLGARD 184 ((registered trademark), PDMS; polydimethylsiloxane) manufactured by Dow Corning, USA can be used.
Among these, PDMS is preferable because the flow path can be easily produced with high precision of several microns, the adhesiveness with the nozzle is good, and the permeability of the discharge liquid is good. The thickness of the organic elastomer layer is 1 to 2000 μm.
If it is less than 1 μm, the flow path is too small, and the discharge liquid hardly penetrates into the flow path.
On the other hand, when the thickness exceeds 2000 μm, it is difficult to obtain a sufficient electric field for liquid discharge because the distance between the electrodes is long even if a counter electrode is provided.
A preferable thickness of the organic elastomer layer is 20 to 100 μm. Within this range, a flow path height of 10 μm optimum for supply of the discharge liquid can be obtained, and the discharge liquid can be supplied in an appropriate amount capable of realizing discharge of fine droplets.
The method for forming the organic elastomer layer on the dummy substrate is not limited. For example, a spin coating method or the like can be employed.
Moreover, as a method of forming a through-hole in an organic elastomer layer, the method of melt | dissolving with a machining method, a laser processing method, a sputter | spatter processing method, transdecahydronaphthalene etc. is employable, for example.
As a method of peeling the organic elastomer layer from the dummy substrate, for example, a metal jig having a flat tip and having a vacuum suction function is contact-sucked to the organic elastomer, and then, it is peeled off from the dummy substrate by applying a tensile stress. The method to do can be adopted.
As a method for attaching the organic elastomer layer to the nozzle body, for example, a method in which the nozzle and the through hole are aligned by an aligner and then self-adhered by applying stress can be employed.

Further, according to the manufacturing method thereof according to an electrostatic attraction type liquid droplet nozzle and claim 7 according to claim 2, fine particles discharged from the liquid discharge port passes through the opening of the gate electrode Then, it flies toward the counter electrode arranged at a predetermined position in the liquid discharge direction.
At this time, when a voltage whose potential is higher than that of the counter electrode is applied to the gate electrode, the fine particles in the discharged discharge liquid are also subjected to a force by an electric field between the gate electrode and the counter electrode. Thereby, the discharge of fine particles can be stabilized.

Furthermore, according to the electrostatic attraction type droplet nozzle according to claim 1 and claim 2 and the manufacturing method thereof according to claims 3 to 7, when a voltage is applied to the emitter tip that is the discharge electrode, In the flow path, the discharged liquid flows toward the liquid discharge port along the needle part of the emitter tip.
At this time, the tip of the liquid flow path is gradually tapered along the outer periphery of the fine needle portion obtained by anodization.
As the distance between the droplet nozzle and the counter electrode is reduced, the liquid attracted by the electric field wets thinly on the surface of the droplet nozzle.
Furthermore, when the electric field in the vicinity of the tip of the head becomes larger than the force synthesized by the surface tension of the discharge liquid and Si and the viscosity and conductivity of the discharge liquid due to the force exerted on the charged discharge liquid, the Taylor cone A meniscus called is formed.
Thereby, a droplet having a size of 1 μm or less is ejected from the nozzle tip.
As a result, a discharge liquid having a minimum droplet diameter of 1 μm or less can be discharged from the discharge port.
Moreover, it is possible to drive an ink jet type droplet discharge device incorporating an electrostatically attractive droplet nozzle even at a low voltage.

According to the serial mounting of the invention in claim 8, to form an organic elastomeric layer in which the organic elastomer forming material in the nozzle body, so producing a liquid flow path to the organic elastomeric layer, a liquid flow path easily and accurately Can be produced.

Embodiments of the present invention will be described below with reference to the drawings. First, a reference example will be described with reference to FIGS.

In FIG. 1, reference numeral 10 denotes an electrostatic attraction type droplet nozzle according to a reference example of the present invention.
This electrostatic attraction type droplet nozzle 10 is a silicon substrate for directly producing an organic EL display by using a discharge liquid (special ink) obtained by adding a predetermined amount of charged fine particles of an organic EL material in a solvent. 11 is incorporated in an ink jet type droplet discharge device that discharges the ink to the nozzle 11.
Specifically, the electrostatic attraction type droplet nozzle 10 communicates with an ink ejection port of an ink tank 13 that stores ejection liquid in the inkjet head 12 of the inkjet type droplet ejection apparatus. As the organic EL material, polyphenylvinylene is adopted. An organic solvent is used as the solvent.

Hereinafter, the electrostatic attraction type droplet nozzle 10 will be described in detail.
The electrostatic attraction type droplet nozzle 10 has a liquid flow path 15 through which the discharge liquid passes through the nozzle body 14, and the electrostatic force generated by the application to the discharge electrode 16 disposed in the liquid flow path 15, A nozzle that discharges liquid from a liquid discharge port 15 a at the tip of the liquid flow path 15.
The nozzle body 14 is mainly composed of a lower-arranged first substrate 17 and an upper-arranged second substrate 18 each having a rectangular shape in plan view.
The first substrate 17 is made of single crystal silicon. The dimensions are 10 mm in length, 5 mm in width, and 500 μm in thickness.
The dimension of the second substrate 18 is made of glass. The dimensions are 10 mm in length, 5 mm in width, and 500 μm in thickness.

Among these, on the surface (upper surface) on the bonding side of the first substrate 17, the four liquid channel grooves 19 constituting a part of the liquid channel 15 except for the front end portion thereof are arranged in the nozzle width direction. Are formed in parallel at a constant pitch (5 μm).
Each liquid channel groove 19 has a rectangular cross section. The groove width is 5 μm and the groove length is 50 μm.
In the base portion of the first substrate 17, an aluminum discharge electrode 16 is formed over the entire exposed surface including the portion where each liquid channel groove 19 is formed.
A bias power source 20 and a pulse power source 21 are connected to the ejection electrode 16. Both power supplies 20, 21 are grounded.

A counter electrode 22 having a frame plate shape is fixed to the distal end portion of the first substrate 17 with a gap having a predetermined width between the distal ends of the liquid channel grooves 19.
A silicon oxide film (not shown) is interposed between the fixed surface between the front end portion of the first substrate 17 and the counter electrode 22. Therefore, the tip portion of the first substrate 17 becomes the electrode holder 23 having an insulating property.
The counter electrode 22 is connected to a droplet acceleration power supply 24. The counter electrode 22 is also grounded.
On the surface of the counter electrode 22 on the nozzle side, the silicon substrate 11 for the organic EL display is disposed with the back surface thereof as a contact surface.

Next, a manufacturing method of the electrostatic attraction type droplet nozzle 10 of the reference example will be described with reference to FIGS. 2 and 3 showing partial views of the electrostatic attraction type droplet nozzle 10.
First, the first substrate 17 is cleaned with an RCA cleaning solution (FIG. 2A).
Next, a Ni (nickel) film for mask 25 is formed on the upper surface of the first substrate 17 by sputtering (FIG. 2B).
The film thickness of the Ni film 25 is 0.5 to 1 μm. The film forming condition for the Ni film 25 is DC sputtering.

Then, a resist 26 is applied to the upper surface of the Ni film 25, and then exposed and developed while leaving a part of the resist 26, thereby forming four windows for forming the liquid flow channel grooves 19 (FIG. 2). (C)).
Next, a part of the Ni film 25 is removed by etching with a phosphoric acid solution through each window (FIG. 2D).
Thereafter, the resist film 26 is stripped with an inorganic or organic resist stripper (FIG. 2E).
Then, a part of the upper surface of the first substrate 17 exposed from the window portion of the Ni film 25 is dry etched by RIE.
As a result, four liquid channel grooves 19 are respectively formed on the upper surface of the first substrate 17 (FIG. 2F).
As etching conditions, SF ₆ : O ₂ : Ar = 4: 6: 4 is used as an etching gas.

The liquid channel groove 19 has a length of 50 μm, a width of 5 μm, and a depth of 12 μm.
Thereafter, the first substrate 17 is immersed in a phosphoric acid solution, and the Ni film 25 remaining on the upper surface of the substrate is removed (FIG. 3A).
Then, using a known lithography technique, the discharge electrode 16 is formed by sputtering aluminum having a thickness of 1 μm only on the exposed surface of the original portion of the first substrate 17 (FIG. 3B).
Then, the second substrate 18 is bonded to the upper surface of the first substrate 17 by anodic bonding.
As a result, the electrostatically attractive droplet nozzle 10 having the four liquid channels 15 mainly including the liquid channel grooves 19 is produced between the bonding surfaces of the two substrates.
The anodic bonding is performed by heating the first substrate 17 to 400 ° C. and applying −1000 V to the second substrate 18.

Next, a method of using the ink jet type droplet discharge apparatus having the electrostatically induced droplet nozzle 10 of the reference example will be described.
As shown in FIG. 1, first, the silicon substrate 11 for organic EL display is disposed on the nozzle side surface of the counter electrode 22 with the back surface thereof as a contact surface.
Further, the surface of each liquid flow path 15 is wetted by the discharge liquid (special ink) supplied from the ink tank 13.
Thereafter, a bias voltage of 2 kV is applied to the ejection electrode 16. Then, an electric field directed to the liquid discharge port 15 a acts on the fine particles of the organic EL material contained in the discharge liquid in each liquid flow path 15.
Thereby, the fine particles are gradually concentrated on the liquid discharge port 15a to form droplets of the discharge liquid.
At this time, electrostatic repulsion acts on the fine particles in the droplets, and the fine particles are likely to fly out from the liquid discharge port 15a toward the counter electrode 22 arranged outward in the ink discharge direction.
However, the electrostatic repulsive force due to the bias voltage is set to be smaller than the surface tension of the discharged liquid. Therefore, the fine particles cannot jump out from the surface of the droplet.
Thereafter, a pulse voltage of about 100 to 300 V is superimposed on the bias voltage according to the discharge amount of the fine particles.
As a result, the electrostatic repulsion force exceeds the surface tension of the droplet, and the fine particles are discharged from the liquid discharge port 15a. The protruding fine particles are collected by the solvent attached to the surface. Therefore, it can be said that the fine particle group in flight is a fine droplet.

As described above, in the reference example, the nozzle body 14 is divided from the first substrate 17 and the second substrate 18, and the liquid channel groove 19 is formed on the bonding surface of the first substrate 17 by RIE. Is formed.
In addition, when the liquid channel groove 19 is dry-etched on the bonding surface of the first substrate 17, the etching direction is not the length direction of the liquid channel groove 19 but the width direction of the liquid channel groove 19. Therefore, the etching amount becomes as small as about 0.2 μm.
As a result, even with dry etching having an aspect ratio of about R10 to R100, bowing is unlikely to occur in the liquid channel groove 19 and thus the liquid channel 15.
Thereby, the liquid flow path 15 having a constant cross-sectional area over the entire length of the flow path can be produced using semiconductor microfabrication.
Therefore, it is possible to discharge a discharge liquid having a minimum droplet diameter of 1 μm or less.
In addition, the ink jet type droplet discharge device can be driven even when the voltage is lower than in the case of the conventional electrostatic attraction type droplet nozzle.

As shown in FIG. 4, instead of the counter electrode 22, a gate electrode 28 having a part of an opening 27 is disposed at the tip of the first substrate 17, and the liquid is removed from the gate electrode 28. The counter electrode 22 may be disposed at a predetermined position in the ejection direction.
In this case, the fine particles discharged from the liquid discharge port 15 a fly through the opening 27 of the gate electrode 28 and then fly toward the counter electrode 22.
At that time, when a voltage having a higher potential than the counter electrode 22 is applied to the gate electrode 28, the fine particles are also subjected to a force by an electric field between the gate electrode 28 and the counter electrode 22. As a result, it is possible to stabilize the discharge of fine particles.

Furthermore, as shown in FIG. 5, a flat needle-like electrode in which a tip formed at an acute angle protrudes from the liquid discharge port 15 a may be employed as the discharge electrode 16.
In the case of this embodiment, when the discharge liquid flows to the liquid discharge port 15a side in the liquid flow path 15 by electrostatic force, the fine particles contained in the discharge liquid are concentrated along the sharp tip of the discharge electrode 16. However, it concentrates on the fine tip of the discharge electrode 16.
In addition, the opening width of the liquid discharge port 15 a is narrowed by a pair of front wall pieces 29 in accordance with the tip of the tapered discharge electrode 16.
As a result, even when the voltage is lower, the ink jet type droplet discharge device can be driven.
And as shown in FIG. 6, you may employ | adopt not only the plate needle-shaped discharge electrode 16 but the gate electrode 28. FIG.
If comprised in this way, both the effect by providing the plate-needle-like discharge electrode 16 and the effect by providing the gate electrode 28 can be acquired simultaneously.

Next, a second embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 7, the electrostatic attraction type droplet nozzle 40 of the second embodiment is accommodated in the ink tank 13 of the ink jet head 12 incorporated in the ink jet type droplet discharge device. The ink tank 13 is a rectangular parallelepiped container.
A large-diameter opening 13a is formed on the liquid discharge side (hereinafter, front side) plate of the ink tank 13 except for the outer peripheral portion.
A discharge liquid supply port 13 b is formed in a part of the plate on the side opposite to the opening 13 a (hereinafter, rear side) of the ink tank 13.
The electrostatic attraction type droplet nozzle 40 includes a nozzle body 14, three discharge electrodes 16 arranged at a predetermined pitch on the surface of the nozzle body 14 on the discharge liquid discharge side, and the opening 13 a from the inside of the ink tank 13. A liquid flow path outer wall film 30 having three raised portions 30a each having a liquid discharge port 15a at the tip is provided at a portion facing the discharge electrode 16.

The nozzle body 14 is made of a silicon substrate that has a rectangular shape in plan view, which is slightly smaller in vertical and horizontal dimensions than the liquid discharge side plate of the ink tank 13.
Thereby, a gap is formed between the both side surfaces of the nozzle body 14 and the both side plates of the ink tank 13 for the discharge liquid to flow into the liquid flow path 15 formed in the nozzle body 14.
The space between the nozzle body 14 and the plate on the supply port 13b side of the ink tank 13 is a liquid storage portion for the discharged liquid.
The discharge electrode 16 in Example 2 is an emitter tip manufactured by anodization (FIG. 8). For convenience of explanation, the same number as the discharge electrode 16 is given to the emitter tip. Details of the anodizing method will be described later.

The emitter chip 16 has a square-shaped chip body 16a (vertical 20 μm × width 20 μm) in plan view and a needle portion 16b (length: 10 to 20 μm, diameter of about 2 μm) protruding from the center of the surface of the chip body 16a. A radius of curvature of 50 to 200 nm).
The needle portion 16b is accommodated in the internal space of the corresponding raised portion 30a with the needle tip protruding from the liquid discharge port 15a.
The raised portion 30a has a conical cylinder shape that is gradually tapered along the outer periphery of the needle portion 16b. The internal space of the raised portion 30 a constitutes a part of the liquid flow path 15.
A counter electrode 22 having a flat plate shape is disposed at a predetermined position in the liquid discharge direction. A silicon substrate 11 for an organic EL display is disposed on the nozzle side surface of the counter electrode 22 in a state where the back surface of the substrate is in contact.

Next, with reference to FIG. 9 and FIG. 10, the manufacturing method of the emitter tip 16 by an anodizing method is demonstrated.
First, a p-type silicon substrate 41 having a surface orientation of (100) (resistivity 2-5 Ωcm) is inserted into the reactor of the RIE apparatus.
Then, the surface layer portion on the back surface of the wafer is dry etched into a mesa shape by RIE (FIG. 9A). The etching amount is 1 μm.
The etching conditions by RIE are high frequency power of 400 W and time of 5 minutes using CF ₄ .
Thereafter, a resist 42 is formed on the mesa-type region 41a on the back surface of the silicon substrate 41 by known lithography.
Then, the silicon substrate 41 is inserted into the reaction furnace of the sputtering apparatus. Subsequently, a metal mask 43 made of aluminum having a thickness of 1 μm is formed on the back surface of the silicon substrate 41 by sputtering.

Then, the resist 42 in the mesa type region 41a is stripped with a predetermined resist stripping solution. As a result, a window portion is formed in the mesa-shaped region 41a of the metal mask 43 and exposed to the outside (FIG. 9B).
Thereafter, the silicon substrate 41 is inserted into an ion implantation furnace, phosphorus ions (P ⁺ ) are ion-implanted into the exposed mesa region 41a, and this portion is formed into an n-type region (n-type silicon region) having a thickness of 0.5 μm. 44 (similarly, FIG. 9B).
The ion implantation conditions are an acceleration voltage of phosphorus ions of 100 keV and an ion implantation amount of 1 × 10 ¹⁴ cm ⁻² .
Next, the metal mask 43 is removed by dipping in a predetermined mask removing solution. Then, heat treatment for activation is performed on the silicon substrate 41 after ion implantation. The heat treatment conditions are a nitrogen atmosphere, a treatment temperature of 800 ° C., and a treatment time of 30 minutes.

Next, as shown in FIG. 10, the silicon substrate 41 having the n-type region 44 is mounted on the opened bottom surface of the anodizing tank 45 in which the HF solution (hydrofluoric acid concentration 25%) is stored.
A Viton O-ring 46a is interposed between the silicon substrate 41 and the bottom of the anodizing tank 45a.
Thereafter, the cathode electrode 46 is inserted under the surface of the HF solution, and the anode electrode 47 is connected to the n-type region 44 of the silicon substrate 41.
Thereafter, a current is passed from the DC power source 38 at a current density of 15 mA / cm ² for 30 minutes. At that time, the current value is measured by the ammeter 39. As a result, most of the p-type silicon region (cathode side) of the silicon substrate 41 becomes porous, and a porous silicon layer 41a is formed.
On the other hand, the n-type region 44 on the anode side is not made porous. As a result, the n-type region 44 is used as a chip body 16a in an area of the n-type region 44, and the emitter 16b protrudes from the center of the inner surface of the n-type region 44 (the surface on the inner side of the silicon substrate 41). A chip 16 is formed (FIG. 9C).
At this time, the back surface portion of the chip body 16 a slightly protrudes outward from the back surface of the silicon substrate 41.

Next, the emitter chip 16 thus fabricated is taken out from the silicon substrate 41.
That is, the exposed back surface of the chip body 16a is bonded to the surface of the nozzle body 14 made of single crystal silicon by Van der Waals force (FIG. 9D). Thereby, the bonded substrate board 45 is formed.
The nozzle body 14 is subjected to a hydrophilic treatment before being bonded. Specifically, after the RCA cleaning, the nozzle body 14 is etched for 1 minute with a hydrofluoric acid solution (hydrofluoric acid concentration 1%), and the natural oxide film on the surface of the nozzle body 14 is removed. Then, the nozzle body 14 is immersed in pure water for 10 minutes.
After bonding, the film is dried in an atmosphere with a humidity of 50%.
Subsequently, heat treatment for strengthening the bonding strength and oxidizing the porous silicon layer 41a is performed in an oxygen atmosphere at 1000 ° C. for 2 hours (FIG. 9E). At that time, the porous silicon layer 41a is thermally oxidized to become an oxidized porous silicon layer 41b.
Next, the oxidized porous silicon layer 41b is etched from the bonded substrate with an etching solution of HF: H ₂ O ₂ = 1: 5, and the emitter chip 16 integrated with the nozzle body 14 is taken out (FIG. 9 (f )).

Next, with reference to FIGS. 11 and 12, a method of forming the liquid flow path 15 to the nozzle body 14 will be described.
First, an insulating film 49 made of silicon dioxide including the emitter chip 16 is formed on the bonding side of the emitter body 16 of the nozzle body 14 by the plasma CVD method (FIG. 11A).
This film formation is performed by supplying SiH ₄ gas for 20 minutes at a flow rate of 0.05 liter / min into a reaction furnace having a heating temperature of 300 ° C. and an oxygen atmosphere. The thickness of the insulating film 49 is 1 μm.
Then, a liquid channel outer wall film 30 made of silicon nitride is formed on the opposite side of the insulating film 49 from the nozzle body 14 by plasma CVD (FIG. 11B). The film thickness of the liquid flow path outer wall film 30 is 1 μm.
At the time of forming the liquid flow path outer wall film 30, SiH ₄ gas is supplied for 20 minutes at a flow rate of 0.05 liter / min into a reactor having a heating temperature of 300 ° C. and an NH ₃ gas atmosphere.
As a result, in the laminated insulating film 49 and liquid channel outer wall film, the raised portion 49a of the insulating film 49 and the liquid channel outer wall are formed in the region facing the needle portion 16b of the discharge electrode 16 in order from the lower layer. The raised portions 30a of the film 30 are formed respectively.

Thereafter, a resist film 51 having a thickness that allows the liquid flow path outer wall film 30 to be completely buried, specifically 2 μm, is applied to the opposite side of the liquid flow path outer wall film 30 from the nozzle body 14 by spin coating (see FIG. FIG. 11 (c)).
Subsequently, the surface layer of the resist film 51 is dry-etched by RIE together with the protruding portions 49a of the insulating film 49 and the tips of the protruding portions 30a of the liquid flow path outer wall film 30 (FIG. 12A).
Thereby, the needle tip of the needle part 16b is exposed and the liquid discharge port 15a is exposed. The diameter of the liquid discharge port 15a is about 5 μm.
At this time, the liquid discharge port 15 a is closed by the insulating film 49. The etching conditions for RIE are 5 minutes at a high frequency power of 400 W using a mixed gas of CF ₄ and oxygen.

Thereafter, the resist film 51 is stripped with a predetermined resist stripping solution (FIG. 12B). Then, in the liquid flow path outer wall film 30, a plurality of guide grooves 30b are dry-etched by RIE along imaginary lines connecting the raised portions 30a (FIGS. 12C and 12C1).
Further, the guide grooves 30 b on both ends of the imaginary line reach both ends of the liquid flow path outer wall film 30. Each guide groove 30b has a width of 10 μm and a depth of 2 μm. RIE conditions are CF ₄ gas and high frequency power of 500 W for 20 minutes.
Next, the nozzle body 14 is immersed in a hydrofluoric acid solution (hydrofluoric acid concentration 10%) for 5 minutes.
As a result, the hydrofluoric acid solution wet-etches each zone of each raised portion 30a and each zone of each guide groove 30b in the insulating film 49 via each liquid discharge port 15a and each guide groove 30b. As a result, the liquid flow path 15 is formed along the imaginary line (FIGS. 12D and 12D1).

Next, a method of using the ink jet type droplet discharge apparatus having the electrostatic attraction type droplet nozzle 40 of Example 2 will be described.
As shown in FIG. 7, first, the discharge liquid is stored in the liquid storage part in the ink tank 13, and the voltage from the bias power source 20 is applied to the emitter chip 16.
As a result, the discharge liquid stored in the liquid storage portion flows into the liquid flow path 15 from both ends of the liquid flow path 15 through the gaps on both sides of the nozzle body 14.
Thereafter, the discharged liquid passes through the liquid flow path 15 and reaches the internal space of each raised portion 30a. Within these raised portions 30a, the discharge liquid flows to the corresponding liquid discharge port 15a while gradually concentrating the fine particles along the needle portion 16b of the emitter tip 16. Thus, a droplet having a diameter of about 1 μm is formed at the liquid discharge port 15a.
Subsequently, the voltage from the pulse power source 21 is superimposed on the emitter chip 16.
As a result, the fine particles in the droplets of the liquid discharge port 15a that pass through each liquid discharge port 15a are discharged toward the silicon substrate 11 for the organic EL display disposed on the counter electrode 22 side.

Thus, when a voltage is applied to the emitter tip 16, the discharge liquid flows along the needle portion 16b toward the liquid discharge port 15a in the internal space of the raised portion 30a.
At this time, the tip of the liquid flow path 15 is gradually tapered along the outer periphery of the fine needle portion 16b (diameter 2 μm, needle tip curvature radius 200 nm) obtained by anodization.
Therefore, it is possible to discharge droplets having a minimum droplet diameter smaller than that in the reference example from the liquid discharge port 15a.
As a result, the ink jet droplet discharge apparatus can be driven at a lower voltage than in the reference example .
Other configurations, operations, and effects are in a range that can be estimated from the reference example, and thus the description thereof is omitted.

Next, an electrostatic attraction type droplet nozzle according to Embodiment 3 of the present invention will be described with reference to FIGS.
As shown in FIG. 13, the electrostatically attractive droplet nozzle 60 of Example 3 has a gate electrode around each raised portion 30 a of the liquid flow path outer wall film 30 via an insulating electrode holder 61. 28 is formed.
Hereinafter, a method for forming the gate electrode 28 will be described in detail with reference to FIGS.
First, a thick resist is applied on the outer surface side of the liquid flow path outer wall film 30 to form an insulating layer 62 (FIG. 14A). The thickness of the insulating layer 62 is 30 μm.
Therefore, the tip of the needle portion 16 b protruding from each liquid discharge port 15 a is buried under the surface of the insulating layer 62.
Next, the insulating layer 62 is irradiated with light from a light source through a photomask (not shown) to expose a portion of the insulating layer 62 facing the liquid discharge port 15a (same FIG. 14A).

Subsequently, a conductive layer 63 made of PolySi is formed on the surface of the insulating layer 62 by sputtering (FIG. 14B). The thickness of the conductive layer 63 is 1 μm. The film forming condition of the conductive layer 63 is a direct current sputtering method.
Thereafter, a thin resist 64 is applied on the surface of the conductive layer 63, and the resist 64 is exposed and developed.
As a result, a window portion is formed in a portion of the resist 64 excluding the formation region of the gate electrode 28.
Subsequently, the conductive layer 63 is immersed in the mixed acid solution. Thereby, an unnecessary portion of the conductive layer 63 is acid-etched through the window portion of the resist 64.
Therefore, the gate electrode 28 having the opening 27 inside is formed at a predetermined position on the surface of the insulating layer 62 (FIG. 14C). Thereafter, the resist 64 is stripped with a predetermined resist stripping solution.
Next, the resist insulating layer 62 is developed. As a result, the exposed portion of the insulating layer 62 is removed.
As a result, an annular electrode holder 61 having an internal space that communicates the opening 27 and the liquid discharge port 15a is formed at a portion facing the opening 27 (FIG. 14D).

Next, a method for forming the gate electrode 28 when the material of the electrode holder 61 is changed to silicon dioxide will be described in detail with reference to FIG.
First, silicon dioxide for the insulating layer 62A is grown thickly (30 μm) on the outer surface side of the liquid flow path outer wall film 30 by plasma CVD (FIG. 15A).
During film formation, a source gas of SiH ₄ is supplied at a rate of 0.05 liter / min for 60 minutes into a reaction furnace having an oxygen atmosphere and a furnace temperature of 350 ° C.
As the source gas, Si (OC ₂ H ₅ ) ₄ gas may be used instead of SiH ₄ gas.
Next, a conductive layer 63 made of PolySi is formed on the surface of silicon dioxide by a plasma CVD method to a thickness of 1 μm (FIG. 15B). During the film formation, SiH ₄ gas is supplied for 30 minutes into a reactor having a furnace temperature of 600 ° C.

Then, 2 μm of a resist 64 is applied on the surface of the conductive layer 63, and the resist 64 is exposed and developed on a portion excluding the formation region of the gate electrode 28.
As a result, a window portion is formed in the resist 64 except for the formation region of the gate electrode 28.
Subsequently, an unnecessary portion of the conductive layer 63 is acid etched with a mixed acid solution.
As a result, a gate electrode 28 having an opening 27 inside is formed at a predetermined position on the surface of silicon dioxide (FIG. 15C).
Subsequently, a resist 64 is applied to the surface of silicon dioxide including the gate electrode 28.
The resist 64 is exposed and developed in a portion excluding the formation region of the internal space that communicates the opening 27 and the liquid discharge port 15a.
Thereby, a window portion is formed in the resist 64 except for the formation region of the internal space.
Next, a part of the insulating layer 62A is wet-etched with an HF solution (hydrofluoric acid concentration 10%) through this window portion.
Thus, unnecessary portions of silicon dioxide are removed.
As a result, an annular electrode holder 61 having an internal space at a portion facing the opening 27 is formed (FIG. 15D).

As described above, since the gate electrode 28 is formed through the electrode holder 61 at the portion facing the raised portion 30a of the liquid flow path outer wall film 30, the droplets discharged from the liquid discharge port 15a are After passing through the opening 27 of the gate electrode 28, it jumps out toward the counter electrode 22 disposed at a predetermined position in the liquid discharge direction.
At that time, if a voltage having a potential higher than that of the counter electrode 22 is applied to the gate electrode 28, the fine particles in the ejected droplets are also subjected to a force by an electric field between the gate electrode 28 and the counter electrode 22.
Thereby, the discharge of droplets (fine particles) can be stabilized.
Other configurations, operations, and effects are the same as those of the second embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 16, the manufacturing method of the electrostatic attraction type droplet nozzle 70 using an organic elastomer layer is demonstrated in detail as a method of forming the liquid flow path in the nozzle body, which is the fourth embodiment. .
First, a resist structure 72 having a height of about 10 μm, a width of 10 μm, and an arbitrary length is formed on a dummy substrate 71 made of single crystal silicon having a thickness of 500 μm and a flat surface by a photolithographic technique (FIG. 16A). ).
Thereafter, a mixture of 10 parts by weight of a curing agent with respect to 100 parts by weight of PDMS (polydimethylsiloxane) is uniformly applied to the surface of the dummy substrate 71 with a thickness of 30 μm using a spin coater.
Then, it cures at 100 degreeC for 1 hour, and forms the organic elastomer layer 73 (FIG.16 (b)).
Then, a through hole 73a reaching the resist structure 72 is formed at a predetermined position of the organic elastomer layer 73 by a laser processing method (FIG. 16C).
The diameter of the through hole 73a is 10 μm. In the laser processing, laser light is passed through a convex lens to converge at a position where the through hole 73a is opened, and the laser light is irradiated at an output of 100 mJ for 0.5 seconds.

Next, a metal jig having a flat true tip and having a vacuum adsorption function is contact-adsorbed to the organic elastomer layer 73, and thereafter, a tensile stress is applied to peel the organic elastomer layer 73 from the dummy substrate 71 (see FIG. 16 (d)).
Thereby, the through-hole 73a becomes a desired shape penetrating the front and back surfaces of the organic elastomer layer 73.

Thereafter, in a state where the discharge electrode 16 is inserted into the through-hole 73a, the peeled organic elastomer layer 73 is aligned and bonded to the surface of the nozzle body 14 on the discharge electrode side using the aligner 74 (FIG. 16E). ).
Specifically, each of the nozzle body 14 and the organic elastomer layer 73 is vacuum-adsorbed, and when the through hole 73a in the organic elastomer layer 73 is positioned on the needle portion 16b on the nozzle body 14, the nozzle body 14 is raised, Stress is applied in contact with the organic elastomer layer 73.

Thereby, the organic elastomer layer 73 can be self-adhered to the nozzle body 14 without using an adhesive or the like.
Thus, since the organic elastomer layer 73 made of an organic elastomer is formed on the nozzle body 14 and the liquid flow path 15 is formed in the organic elastomer layer 73, the liquid flow path 15 can be easily and highly accurately formed. Can be produced.
Moreover, PDMS has improved adhesion with the nozzle body 14 made of silicon.
Furthermore, since the organic elastomer layer 73 in which the liquid discharge port 15a is formed is made of PDMS, the hydrophilicity of the liquid flow path 15 is high, and the permeability of the discharge liquid into the liquid flow path 15 is increased.
Other configurations, operations, and effects are the same as those of the second embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 17 and FIG. 18, the manufacturing method of the electrostatic attraction type droplet nozzle 70A which formed the organic elastomer layer of Example 5 in the nozzle main body 4 is demonstrated in detail.
Here, in Example 4, in order to improve the releasability of the organic elastomer layer 73 from the dummy substrate 71, the CF ₄ is subjected to plasma treatment after the production of the resist structure 72, and the surface of the silicon dummy substrate 71 and the resist are processed. The surface of the structure 72 is modified to a fine uneven surface, and the surface is terminated with F (fluorine).
Instead of CF ₄ , a fluorinated gas such as CHF ₃ or SF ₆ or a mixed gas of fluorinated gas and O ₂ may be employed.
The conditions for the plasma treatment are about 60 seconds at a power of 200 W and a pressure of 50 Pa.
Other configurations, operations, and effects are the same as those in the fourth embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 19, the manufacturing method of the electrostatic attraction type droplet nozzle 70B which is Example 6 and formed the organic elastomer layer in the nozzle body is demonstrated in detail.
Here, in Example 5, a resist film 75 having a thickness of 1 μm is formed over the entire surface of the dummy substrate 71 in order to improve the releasability of the organic elastomer layer 73 from the dummy substrate 71.
The resist structure 72 is formed on the surface of the resist film 75. An organic resin may be applied instead of the resist.
Other configurations, operations, and effects are the same as those in the fourth embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 20 and FIG. 21, the manufacturing method of the electrostatic attraction type droplet nozzle 70C which formed the organic elastomer layer 73 in the nozzle main body 14 of Example 7 is demonstrated in detail.
Here, in Example 6, in order to improve the releasability of the organic elastomer layer 73 from the dummy substrate 71, the CF ₄ is subjected to plasma treatment after the formation of the resist film 75, and the surface of the resist film 75 and the resist structure 72 are formed. The surface is modified to a fine uneven surface. Instead of CF ₄ , a fluorinated gas such as CHF ₃ or SF ₆ or a mixed gas of fluorinated gas and O ₂ may be employed.
Other configurations, operations, and effects are the same as those in the fourth embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 22 and FIG. 23, the manufacturing method of the electrostatic attraction type droplet nozzle 70D which formed the organic elastomer layer 73 in the nozzle main body 14 of Example 8 is demonstrated in detail.
Here, as another method for forming the through hole 73a in the fourth embodiment, plasma processing using masking is employed.
That is, in the method for forming the through hole 73a in the organic elastomer layer 73, the portion of the organic elastomer layer 73 excluding the through hole forming portion is masked by the masking film 76 made of Si ₃ N ₄ or the like using photolithography technology. To do.

Thereafter, the opening 76a is opened by O ₂ plasma treatment.
Instead of Si ₃ N ₄ , a photoresist, SiO ₂ , Al, Mo, W, Ti, WSi ₂ or the like may be employed.
Further, instead of O ₂ , a fluorinated gas such as CF ₄ or SF ₆ or a halogenated gas may be used. Further, a mixed gas of O ₂ and a fluorinated gas or a halogenated gas may be used.
Thereafter, the through hole 73a is formed using the opening 76a.
Other configurations, operations, and effects are the same as those in the fourth embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 24 and FIG. 25, the manufacturing method of the electrostatic attraction type droplet nozzle 70E which formed the organic elastomer layer 73 in the nozzle main body 14 of Example 9 is demonstrated in detail.
Here, in Example 4, in order to increase the strength of the organic elastomer layer 73 and improve the releasability from the dummy substrate 71, SiC filler 77 is dispersed in PDMS as a material of the organic elastomer layer 73.

Moreover, in order to disperse | distribute uniformly, an ultrasonic wave is applied.
The SiC filler 77 is a composite reinforcing fiber material having high strength, high elastic modulus, and high heat resistance mainly composed of SiC.
For example, Toka whiskers ((registered trademark), silicon carbide whiskers) manufactured by Tokai Carbon Co., Ltd. can be employed.
The amount of SiC filler 77 added is 3 parts by weight with respect to 100 parts by weight of PDMS.
Instead of SiC filler 77, _Al 2 _{O 3} (alumina), CaCO ₃ (calcium carbonate), talc _{(4SiO 2 3MgOH 2 O),} Al 2 O 3 2SiO 2 2H 2 O ( kaolin), SiO ₂ (silica), K ₂ Al ₄ (Si ₃ Al) ₂ O ₂₀ (OH) ₄ (mica), CaOSiO ₂ (wollastonite), K ₂ OnTiO ₂ (potassium titanate, whiskers), 6CaO6SiO ₂ H ₂ O (zonotonite), MgSO ₄ 5MgO8H ₂ O (basic magnesium sulfate), ZnO (zinc oxide), 9Al ₂ O ₃ 2B ₂ O ₃ (aluminum borate, whisker), or the like may be used.
Other configurations, operations, and effects are the same as those in the fourth embodiment, and thus description thereof is omitted.

Next, with reference to FIG. 26 and FIG. 27, the manufacturing method of the electrostatic attraction type droplet nozzle 70F which formed the organic elastomer layer 73 in the nozzle main body 14 of Example 10 is demonstrated in detail.
Here, in order to reduce the voltage of liquid discharge, the organic elastomer layer 73 of Example 4 is thicker than the length of the discharge electrode 16, and the gate electrode 78 is formed around the formation portion of the through hole 73a. .
The gate electrode 78 uses Al, PolySi, or the like.
The electrostatic attraction type droplet nozzle 70F applies a predetermined bias voltage between the ejection electrode 16 and the counter electrode 22, applies a predetermined pulse voltage to the gate electrode 78, and superimposes the pulse voltage on the bias voltage. As a result, the droplets of the discharge liquid can be discharged onto the surface of the silicon substrate 11 disposed at a predetermined position in the liquid discharge direction.
Other configurations, operations, and effects are the same as those in the fourth embodiment, and thus description thereof is omitted.

It is a principal part perspective view which shows the use condition of the electrostatic attraction-type droplet nozzle which concerns on the reference example of this invention. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle concerning the reference example of this invention. It is a continuation of the flow sheet of FIG. It is a principal part perspective view which shows the electrostatic attraction-type droplet nozzle which concerns on the other form of the reference example of this invention. It is a principal part perspective view which shows the electrostatic attraction-type droplet nozzle which concerns on another form of the reference example of this invention. It is a principal part perspective view which shows the electrostatic attraction-type droplet nozzle which concerns on another form of the reference example of this invention. It is principal part sectional drawing which shows the use condition of the electrostatic attraction-type droplet nozzle which concerns on Example 2 of this invention. It is a perspective view of the emitter tip incorporated in the electrostatic attraction type droplet nozzle concerning Example 2 of this invention. It is a flow sheet which shows the preparation method by anodizing of the emitter chip incorporated in the electrostatic attraction type droplet nozzle concerning Example 2 of this invention. It is a schematic diagram of the anodizing apparatus used for manufacture of the emitter chip incorporated in the electrostatic attraction type droplet nozzle concerning Example 2 of this invention. It is a flow sheet which shows the formation method of the liquid flow path which comprises a part of electrostatic attraction type droplet nozzle which concerns on Example 2 of this invention. It is a continuation of the flow sheet which shows the formation method of the liquid flow path which comprises a part of electrostatic attraction type droplet nozzle which concerns on Example 2 of FIG. It is principal part sectional drawing of the electrostatic attraction type droplet nozzle which concerns on Example 3 of this invention. It is a flow sheet which shows the formation method of the liquid flow path which comprises some electrostatic attraction-type droplet nozzles concerning Example 3 of this invention. It is a flow sheet which shows the formation method of another liquid channel which constitutes a part of electrostatic attraction type droplet nozzle concerning Example 3 of this invention. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle which concerns on Example 4 of this invention. It is a continuation of the manufacturing method flow sheet of the electrostatic attraction type droplet nozzle which concerns on Example 5 of this invention. It is a continuation of the manufacturing method flow sheet of the electrostatic attraction type droplet nozzle which concerns on Example 5 of FIG. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle which concerns on Example 6 of this invention. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle concerning Example 7 of this invention. It is a continuation of the manufacturing method flow sheet of the electrostatic attraction type droplet nozzle which concerns on Example 7 of FIG. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle concerning Example 8 of this invention. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle which concerns on Example 8 of FIG. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle concerning Example 9 of this invention. It is a flow sheet which shows the manufacturing method of the electrostatic attraction-type droplet nozzle which concerns on Example 9 of FIG. It is a flow sheet which shows the manufacturing method of the electrostatic attraction type droplet nozzle which concerns on Example 10 of this invention. It is a flow sheet which shows the manufacturing method of the electrostatic attraction-type droplet nozzle which concerns on Example 10 of FIG. It is sectional drawing which shows the use condition of the electrostatic attraction-type droplet nozzle which concerns on the conventional means. It is a principal part expansion perspective view of the electrostatic attraction type droplet nozzle which concerns on the conventional means.

Explanation of symbols

10, 40, 60, 70, 70A, 70B, 70C, 70D, 70E, 70F electrostatic attraction type droplet nozzle,
14 Nozzle body,
15 liquid flow path,
15a Liquid outlet,
16 Discharge electrode (emitter tip),
16a chip body,
16b Needle part,
17 first substrate,
18 second substrate,
19 Liquid channel groove,
23 electrode holder,
27 opening,
28, 78 gate electrodes,
30a ridge,
41 silicon substrate,
49 Insulating film,
49a ridge,
30 Liquid channel outer wall membrane,
51 resist film,
61 electrode holder,
62 insulation layer,
63 conductive layer,
71 dummy substrate,
73 organic elastomer layer,
73a Through hole.

Claims (8)

A liquid flow path through which the discharge liquid passes is formed in the nozzle body, and the discharge liquid is generated at the tip of the liquid flow path by the electrostatic force generated by applying a voltage to the discharge electrode arranged in the liquid flow path. In the electrostatic attraction type droplet nozzle discharged from the discharge port,
The discharge electrode is an emitter tip made by anodization having a tip body and a needle portion protruding from the surface of the tip body,
The needle part is housed in the liquid flow path with a space in a state where the needle tip protrudes from the liquid discharge port,
An electrostatically attracting droplet nozzle in which the tip of the liquid flow path is gradually tapered along the outer periphery of the needle. A gate electrode protrudes from the formation portion of the liquid discharge port at a predetermined position in the liquid discharge direction separated from the liquid discharge port via an insulating electrode holder. The electrostatic attraction type droplet nozzle according to claim 1, wherein an opening through which the discharged liquid is passed is formed. The nozzle body has a liquid flow path through which the discharged liquid passes, and the discharged liquid is discharged from the liquid discharge port at the tip of the liquid flow path by the electrostatic force generated by application to the discharge electrode disposed in the liquid flow path. In the manufacturing method of the electrostatic attraction type droplet nozzle discharged from
A p-type silicon substrate having an n-type silicon region formed on a part of the contact surface with the hydrofluoric acid solution is subjected to anodization, and the n-type silicon region is used as a main component, and a chip body, A discharge electrode manufacturing step of manufacturing a discharge electrode composed of an emitter tip having a needle portion protruding from the surface;
An electrode bonding step in which the discharge electrode is bonded to the nozzle body with a surface opposite to the needle portion as a bonding surface;
An insulating film forming step of forming an insulating film including the discharge electrode on the discharge electrode bonding side of the nozzle body;
An outer wall forming step of forming a liquid channel outer wall film to be an outer wall of the liquid channel on the opposite side of the nozzle body of the insulating film;
The tip of the raised portion of the insulating film covering the needle portion and the raised portion of the film for the liquid flow path outer wall are respectively removed to expose the needle tip of the needle portion and to form the liquid discharge port An exit forming step;
After forming the liquid discharge port, a part of the insulating film including the raised portion is removed, and a liquid flow path forming step for forming the liquid flow path is provided. . The method of manufacturing an electrostatically attractable droplet nozzle according to claim 3 , wherein the nozzle body is a silicon substrate. The insulating film is a silicon oxide film;
5. The method of manufacturing an electrostatically attractive droplet nozzle according to claim 3, wherein in the liquid flow path forming step, a part of the insulating film is etched with a hydrofluoric acid solution. In the liquid discharge port forming step,
On the side opposite to the nozzle body of the liquid channel outer wall film, a resist film having a thickness at which the needle part is buried is formed,
Subsequently, the surface layer of the resist film is dry-etched together with the tip portions of both raised portions, and the method for producing an electrostatically attractive droplet nozzle according to any one of claims 3 to 5 . An insulating layer and a conductive layer are sequentially formed on the side opposite to the liquid flow path of the liquid flow path outer wall film,
Of the conductive layer, a gate electrode is formed by etching an opening through which the discharge liquid discharged from the liquid discharge port passes in a zone opposite to the liquid discharge port,
Then, the of the insulating layer, the portion facing said opening, of the claims 3 to 6 to form the inner space by etching the electrode holder which communicates the opening portion and the liquid discharge port, The manufacturing method of the electrostatic attraction type | mold droplet nozzle of any one. The nozzle body has a liquid flow path through which the discharged liquid passes, and the discharged liquid is discharged from the liquid discharge port at the tip of the liquid flow path by the electrostatic force generated by application to the discharge electrode disposed in the liquid flow path. In the manufacturing method of the electrostatic attraction type droplet nozzle discharged from
A p-type silicon substrate having an n-type silicon region formed on a part of the contact surface with the hydrofluoric acid solution is subjected to anodization, and the n-type silicon region is used as a main component, and a chip body, A discharge electrode manufacturing step of manufacturing a discharge electrode composed of an emitter tip having a needle portion protruding from the surface;
An electrode bonding step in which the discharge electrode is bonded to the nozzle body with a surface opposite to the needle portion as a bonding surface;
An elastomer layer forming step of forming an organic elastomer layer on the flat surface of the dummy substrate;
A through-hole forming step for forming a through-hole through which the discharge electrode can be inserted with ease through the front and back surfaces of the organic elastomer layer;
An electrostatic attraction type droplet nozzle manufacturing method comprising: an elastomer bonding step in which a discharge electrode is inserted into the through hole and an organic elastomer layer is bonded to a surface on the discharge electrode side of the nozzle body.

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