JP2004136656A - Process for manufacturing electrostatic attraction liquid ejection head, process for manufacturing nozzle plate, driving method for electrostatic attraction liquid ejection head, and electrostatic attraction liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a head ejecting solution, in the form of a liquid drop, from the forward end of a nozzle in which a multiple nozzle is realized by reducing an ejection voltage being applied to an electrode in the nozzle. <P>SOLUTION: In the method for manufacturing an electrostatic attraction liquid ejection head, a plurality of electrodes 142, 142, ... are formed, at first, on a substrate 141 through a film deposition process, a photolithography process and an etching process. A resist film 143' is formed on the substrate 141 to cover the electrodes 142, 142, ... entirely and then exposed and developed. The resist film 143' is formed into micro nozzles 103 corresponding to respective electrodes 142 and standing on the substrate 141 and a channel 145 is formed in each nozzle 103. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for manufacturing a nozzle plate for manufacturing a nozzle plate for discharging droplets onto a substrate, a method for manufacturing an electrostatic suction type liquid discharge head including the nozzle plate, and the electrostatic suction type liquid discharge head. The present invention relates to a method for driving an electrostatic suction type liquid ejection head for driving a liquid ejection head and an electrostatic suction type liquid ejection device provided with the electrostatic suction type liquid ejection head.

The conventional ink jet recording method includes a piezo method in which ink droplets are ejected by deforming an ink flow path by vibrating a piezoelectric element. A heating element is provided in the ink flow path, and the heating element generates heat to generate bubbles. A thermal method that discharges ink droplets in response to pressure changes in the ink flow path due to bubbles, and an electrostatic suction method that charges ink in the ink flow path and discharges ink droplets by the electrostatic suction force of the ink It has been known.
JP-A-11-277747 (FIGS. 2 and 3)

However, the above conventional example has the following problems.
(1) Limit and Stability of Micro Droplet Formation Due to the large nozzle diameter, the shape of the droplet ejected from the nozzle is not stable, and there is a limit to miniaturization of the droplet.
(2) High applied voltage In order to discharge a fine droplet, miniaturization of the discharge port of the nozzle is an important factor. However, according to the principle of the conventional electrostatic suction method, the nozzle diameter is large. As a result, the electric field intensity at the nozzle tip is weak, and it is necessary to apply a high ejection voltage (for example, a very high voltage close to 2000 [V]) in order to obtain the electric field intensity necessary for ejecting a droplet. . Therefore, since a high voltage is applied, drive control of the voltage becomes expensive, and there is also a problem in terms of safety.

Therefore, a first object is to provide a liquid ejection device capable of ejecting minute droplets. At the same time, a second object is to provide a liquid ejection device capable of ejecting stable droplets. It is a third object of the present invention to provide a liquid ejecting apparatus capable of ejecting fine liquid droplets and having high landing accuracy. Further, it is a fourth object of the present invention to provide an inexpensive and highly safe liquid ejecting apparatus capable of reducing the applied voltage.

In order to solve the above-mentioned problems, according to the present invention, in a manufacturing method for manufacturing an electrostatic suction type liquid discharge head having a plurality of nozzles for discharging a solution as droplets from the nozzle tip, A plurality of ejection electrodes for applying a voltage are formed on a substrate, a photosensitive resin layer is formed on the substrate so as to cover the entire plurality of ejection electrodes, and the photosensitive resin layer is exposed and developed. By doing so, the photosensitive resin layer is erected with respect to the substrate in correspondence with each of the discharge electrodes, and the nozzle diameter is formed into a nozzle shape of 30 μm or less, and the nozzle is formed in each of the nozzles. An electrostatic suction type liquid discharge, wherein a flow path in a nozzle is formed so as to communicate from the front end portion to the discharge electrode, and is joined to a solution supply channel corresponding to the plurality of nozzles. To provide a method of manufacturing a head.

Hereinafter, the term “nozzle diameter” refers to the internal diameter at the tip end from which the droplet is discharged (the internal diameter at the tip end of the nozzle). Note that the cross-sectional shape of the liquid ejection hole in the nozzle is not limited to a circle. For example, when the cross-sectional shape of the liquid ejection hole is a polygon, a star, or another shape, it indicates that the circumscribed circle of the cross-sectional shape is 30 [μm] or less. Hereinafter, the same applies to a case where other numerical values are limited in terms of the nozzle diameter or the inner diameter of the nozzle tip. In addition, the term “nozzle radius” indicates a length that is の of the nozzle diameter (the inner diameter of the nozzle tip).

According to a second aspect of the present invention, there is provided the method of manufacturing an electrostatic suction type liquid ejection head according to the first aspect, wherein at least an inner surface of each of the solution supply channels is made insulative and a nozzle tip is provided. A control electrode for controlling a meniscus position of the solution is provided in the solution supply channel.

According to a third aspect of the present invention, in the method for manufacturing the electrostatic suction type liquid discharge head according to the second aspect, the solution supply channel is formed of a piezoelectric material. Provided is a method for manufacturing a suction-type liquid ejection head.

A method according to any one of claims 1 to 3, wherein the nozzle diameter of the nozzle is less than 20 µm. A method for manufacturing a characteristic electrostatic suction type liquid ejection head is provided.

According to a fifth aspect of the present invention, in the method of manufacturing an electrostatic suction type liquid ejection head according to the fourth aspect, the nozzle diameter of the nozzle is 10 μm or less. Provided is a method for manufacturing a liquid ejection head.

According to a sixth aspect of the present invention, there is provided the method of manufacturing an electrostatic suction type liquid ejection head according to the fifth aspect, wherein the nozzle diameter of the nozzle is 8 μm or less. Provided is a method for manufacturing a liquid ejection head.

7. The method of manufacturing an electrostatic suction type liquid ejection head according to claim 6, wherein the nozzle diameter of the nozzle is 4 μm or less. Provided is a method for manufacturing a liquid ejection head.

As in the invention according to claim 8, the method according to any one of claims 1 to 7, wherein the photosensitive resin layer contains fluorine. A method for manufacturing a characteristic electrostatic suction type liquid ejection head is provided.

According to a ninth aspect of the present invention, there is provided a driving method for driving an electrostatic suction type liquid ejection head manufactured by the method for manufacturing an electrostatic suction type liquid ejection head according to any one of the first to eighth aspects. In the method, a tip of each of the nozzles faces a substrate, a chargeable solution is supplied to each of the solution supply channels, and a discharge voltage is applied to each of the plurality of discharge electrodes. Provided is a method for driving an electro-suction type liquid ejection head.

In addition, the “substrate” refers to an object to which the ejected droplet of the solution is landed, and the material is not particularly limited. Therefore, for example, when the above configuration is applied to an ink jet printer, a recording medium such as paper or a sheet corresponds to a base material, and when a circuit is formed using a conductive paste, a circuit is formed. The base to be formed corresponds to the substrate.

According to a tenth aspect of the present invention, in the driving method of the electrostatic suction type liquid ejection head according to the ninth aspect, the solution in each of the nozzle internal flow paths is formed in a convex shape from the tip of the nozzle. Provided is a method for driving an electrostatic suction type liquid discharge head, wherein a raised state is formed.

According to an eleventh aspect of the present invention, in the driving method of the electrostatic suction type liquid ejection head according to the tenth aspect, the solution in each of the nozzle flow paths is formed in a convex shape from the tip of the nozzle. A driving method for an electrostatic suction type liquid discharge head, wherein a discharge voltage is applied to the discharge electrode when a raised state is formed.

According to a twelfth aspect of the present invention, there is provided an electrostatic attraction type liquid ejection head manufactured by the method of manufacturing an electrostatic attraction type liquid ejection head according to any one of the first to eighth aspects. An electrostatic suction type liquid ejection device in which a tip portion of the nozzle can be disposed so as to face a substrate, and a solution supply means for supplying a chargeable solution to each of the nozzle flow paths; And a discharge voltage applying means for applying a discharge voltage to each discharge electrode.

As in the thirteenth aspect of the present invention, in the electrostatic suction type liquid ejecting apparatus according to the twelfth aspect, the solution in each of the nozzle internal flow paths protrudes from the tip of the nozzle in a convex shape. And a convex meniscus forming means for forming the liquid.

As in the invention according to claim 14, in the electrostatic suction type liquid ejecting apparatus according to claim 13, wherein the ejection voltage applying unit is configured such that the convex meniscus forming unit is provided in each of the flow paths in the nozzle. Provided is an electrostatic suction type liquid discharge device, wherein a discharge voltage is applied to the discharge electrode when the solution forms a convex shape from the tip of the nozzle.

According to a fifteenth aspect of the present invention, in the electrostatic suction type liquid ejecting apparatus according to the thirteenth or fourteenth aspect, the convex meniscus forming unit is provided with a piezoelectric element corresponding to each of the nozzles. An electrostatic suction type liquid discharge device is provided, wherein each of the piezoelectric elements changes the pressure of the solution in the nozzle flow path by deformation.

In a method for manufacturing a nozzle plate having a plurality of nozzles for discharging a solution as droplets from a nozzle tip, a plurality of discharge electrodes for applying a discharge voltage are provided on a substrate. Forming a photosensitive resin layer on the substrate so as to cover the entirety of the plurality of discharge electrodes, and exposing and developing the photosensitive resin layer to discharge the photosensitive resin layer to each of the discharge electrodes. The nozzle is formed upright with respect to the substrate corresponding to the electrode, and is formed in a nozzle shape having a nozzle diameter of 30 μm or less, and a flow path in the nozzle is formed in each of the nozzles so as to communicate from the tip of the nozzle to the discharge electrode. And a method for manufacturing a nozzle plate.

(17) The method of manufacturing a nozzle plate according to (16), wherein the nozzle diameter of the nozzle is less than 20 μm.

(18) A method of manufacturing a nozzle plate as described in (18), wherein the nozzle diameter of the nozzle is 10 μm or less.

(18) A method of manufacturing a nozzle plate according to the eighteenth aspect, wherein the nozzle diameter of the nozzle is 8 µm or less.

{Circle around (2)} The method of manufacturing a nozzle plate according to claim 19, wherein the nozzle diameter of the nozzle is 4 μm or less.

The method for manufacturing a nozzle plate according to any one of claims 16 to 20, as in the invention according to claim 21, wherein the photosensitive resin layer contains fluorine. And a method for producing the same.

The present invention is characterized in that the electric field is concentrated at the tip of the nozzle by increasing the electric field strength by making the nozzle have an ultra-small diameter unlike the conventional one. The reduction in the diameter of the nozzle will be described in detail later. In such a case, it is possible to discharge droplets even if there is no counter electrode facing the tip of the nozzle. For example, in a state where the counter electrode is not present, when the base material is arranged so as to face the nozzle tip portion, and when the base material is a conductor, the surface symmetry of the nozzle tip portion with respect to the receiving surface of the base material is used. A mirror image charge of opposite polarity is induced at a certain position, and when the substrate is an insulator, a video charge of opposite polarity is induced at a symmetric position determined by the dielectric constant of the substrate with respect to the receiving surface of the substrate. . The droplet is caused to fly by electrostatic force between the charge induced at the nozzle tip and the mirror image charge or the image charge.

However, the configuration of the present invention makes it possible to eliminate the need for the counter electrode, but the counter electrode may be used in combination. When the counter electrode is used in combination, it is preferable that the substrate is arranged along the opposing surface of the opposing electrode and the opposing surface of the opposing electrode is disposed perpendicular to the direction in which droplets are ejected from the nozzle, It is also possible to use electrostatic force due to the electric field between the nozzle and the counter electrode to guide the flying electrode, and if the counter electrode is grounded, the charge of the charged droplet can escape through the counter electrode. It is possible to obtain the effect of reducing the accumulation of electric charges, so that it can be said that it is preferable to use them together.

Further, since the nozzles are formed only by exposing and developing the photosensitive resin layer as in the inventions described in claims 1 and 16, flexibility in the shape of the nozzles and compatibility with a line head having a large number of nozzles are provided. This is advantageous in terms of performance and manufacturing cost.

Further, in the invention according to claim 2, the control electrode for controlling the meniscus position is provided in the solution supply channel, and changes the volume of the solution supply channel by applying a voltage to the control electrode, thereby changing the volume of the nozzle tip. It controls the meniscus position of the solution.

Further, in the invention according to claim 2, the reason why the inner surface of the solution supply channel is made insulative is to prevent a stroke through the solution existing between the discharge electrode and the control electrode, and May be covered with an insulating layer. It is necessary to determine the material and thickness of the insulating layer in consideration of the conductivity of the solution and the applied voltage. For example, vapor deposition of parylene resin, CVD of SiO ₂ , Si ₃ N _{4 and} the like are suitable.

Further, since the solution in the flow path in the nozzle protrudes from the tip at the tip of each nozzle, the electric field is concentrated at the projecting portion of the solution. And the electric field strength is greatly increased. For this reason, even if the voltage applied to the electrode is low, the droplet is ejected from the front end portion against the surface tension of the solution, and the droplet flies.

(4) By setting the internal diameter of the nozzle to less than 20 [μm] as in the inventions of claims 4 and 17, the electric field intensity distribution becomes narrow. Thereby, the electric field can be concentrated. As a result, the formed droplets can be minute and have a stable shape, and the total applied voltage can be reduced. In addition, immediately after being discharged from the nozzle, the droplet is accelerated by an electrostatic force acting between the electric field and the electric charge. However, when the droplet is separated from the nozzle, the electric field sharply decreases. Thereafter, the droplet is decelerated by air resistance. However, the microdroplet and the droplet in which the electric field is concentrated are accelerated by the mirror image force as approaching the base material and the counter electrode. By balancing the deceleration due to the air resistance and the acceleration due to the mirror image force, it is possible to stably fly the fine droplets and improve the landing accuracy.

By setting the internal diameter of the nozzle to 10 [μm] or less as in the invention according to claims 5 and 18, it is possible to further concentrate the electric field, to further miniaturize the droplet and to reduce the size of the counter electrode during flight. Since it is possible to reduce the influence of the variation in distance on the electric field strength distribution, it is possible to reduce the influence of the position accuracy of the counter electrode, the characteristics of the base material and the thickness on the droplet shape, and the impact on the landing accuracy. it can.

By setting the inner diameter of the nozzle to 8 [μm] or less as in the invention according to claims 6 and 19, it is possible to further concentrate the electric field, to further miniaturize the droplet, and to reduce the opposing electrode and Since it is possible to reduce the influence of variations in the distance of the base material on the electric field intensity distribution, the position accuracy of the counter electrode and the base material, the characteristics of the base material and the thickness on the droplet shape, and the impact on the landing accuracy are reduced. The effect can be reduced.

By setting the internal diameter of the nozzle to 4 [μm] or less as in the invention according to claims 7 and 20, remarkable electric field concentration can be achieved, the maximum electric field intensity can be increased, and It is possible to miniaturize a stable droplet and increase the initial discharge speed of the droplet. As a result, the flight stability is improved, so that the landing accuracy can be further improved and the ejection responsiveness can be improved.

Further, it is desirable that the inner diameter of the nozzle is larger than 0.2 [μm]. By making the inner diameter of the nozzle larger than 0.2 [μm], the charging efficiency of the droplets can be improved, so that the ejection stability of the droplets can be improved.
(1) In the configuration of each of the above claims, the nozzle (that is, the photosensitive resin layer) is formed of an electrically insulating material, and an electrode for applying a discharge voltage is inserted into the nozzle, or plating is performed to function as the electrode. Is preferred.
(2) In the configuration of each claim or the configuration of (1), the nozzle (that is, the photosensitive resin layer) is formed of an electrically insulating material, and an electrode is inserted into the nozzle or plating is formed as the electrode. It is preferable to provide a discharge electrode outside the nozzle.

The discharge electrode outside the nozzle is provided, for example, on the entire periphery or a part of the end face of the nozzle or the side face on the tip end side of the nozzle.

According to (1) and (2), in addition to the functions and effects according to the above-described claims, the ejection force can be improved, so that the droplet can be ejected at a low voltage even if the nozzle diameter is further reduced.
(3) In the structure of each of the above-mentioned claims, the structure of the above (1) or (2), it is preferable that the base material is formed of a conductive material or an insulating material.
(4) In the structure of each of the above claims, the structure of (1), (2) or (3), the discharge voltage V applied to the discharge electrode preferably satisfies the range of the following expression (1).

　ただし、γ：溶液の表面張力［Ｎ／ｍ］、ε₀：真空の誘電率［Ｆ／ｍ］、ｄ：ノズル直径［ｍ］、h：ノズル−基材間距離［ｍ］、ｋ：ノズル形状に依存する比例定数（１．５＜ｋ＜８．５）とする。
（５）上記各請求項の構成、上記（１）、（２）、（３）又は（４）の構成において、印加する吐出電圧が１０００［Ｖ］以下であることが好ましい。

Here, γ: surface tension of the solution [N / m], ε ₀ : dielectric constant of vacuum [F / m], d: nozzle diameter [m], h: distance between nozzle and substrate [m], k: nozzle The proportional constant (1.5 <k <8.5) depends on the shape.
(5) In the configuration of each of the above-mentioned claims, the above-mentioned (1), (2), (3) or (4), it is preferable that the applied ejection voltage is 1000 [V] or less.

By setting the upper limit value of the discharge voltage in this way, it is possible to easily perform the discharge control, and to easily improve the durability of the apparatus and the reliability by executing safety measures.
(6) In the configuration of each of the above-mentioned claims, the above-mentioned (1), (2), (3), (4) or (5), it is preferable that the applied ejection voltage is 500 [V] or less.

により決まる時定数τ以上のパルス幅Δtを印加する構成としても良い。ただし、ε：溶液の誘電率［Ｆ／ｍ］、σ：溶液の導電率［Ｓ／ｍ］とする。 By setting the upper limit value of the discharge voltage in this way, it is possible to further facilitate the discharge control, to further improve the durability of the apparatus, and to further improve the reliability by executing safety measures.
(7) In the configuration of each of the above-mentioned claims, and in any one of the above-mentioned (1) to (6), setting the distance between the nozzle and the base material to be 500 [μm] or less is effective even when the nozzle diameter is small. This is preferable because high landing accuracy can be obtained.
(8) In any one of the above-described claims and any one of the above-mentioned constitutions (1) to (7), it is preferable that pressure is applied to the solution in the nozzle.
(9) In the configuration according to any one of the claims, and in any one of the configurations (1) to (8), when discharging by a single pulse,

May be applied to apply a pulse width Δt that is equal to or greater than the time constant τ determined by Here, ε: the dielectric constant of the solution [F / m], σ: the conductivity of the solution [S / m].

According to the present invention, since the nozzle is formed only by exposing and developing the photosensitive resin layer, it is advantageous in flexibility in nozzle shape, compatibility with a line head having many nozzles, and manufacturing cost.

Also, since a plurality of nozzle shapes are formed and the respective flow paths in the nozzles are guided to the electrodes, it is possible to apply a discharge voltage to the solution supplied to the flow paths in the respective nozzles through the electrodes. When a discharge voltage is applied to the electrode, droplets are discharged from the tip of the nozzle shape, and a pattern in which the droplets landed on the substrate become dots is formed on the substrate. Since a plurality of such nozzle shapes are formed on the substrate, a pattern can be formed quickly.

In such a case, it is possible to discharge droplets without a counter electrode facing the tip of the nozzle. For example, in a state where the counter electrode is not present, when the base material is arranged so as to face the nozzle tip portion, and when the base material is a conductor, the surface symmetry of the nozzle tip portion with respect to the receiving surface of the base material is used. A mirror image charge of opposite polarity is induced at a certain position, and when the substrate is an insulator, a video charge of opposite polarity is induced at a symmetric position determined by the dielectric constant of the substrate with respect to the receiving surface of the substrate. . The droplet is caused to fly by electrostatic force between the charge induced at the nozzle tip and the mirror image charge or the image charge.

Furthermore, in the present invention, since the solution in the flow path in the nozzle protrudes from the tip portion at the tip portion of each nozzle shape, even if the voltage applied to the electrode is low, the solution has a convex portion. , The electric field is concentrated, and the electric field intensity is very high. Therefore, even if the voltage applied to the electrode is low, the droplet is ejected from the tip of the nozzle shape.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are provided with various technically preferable limits for carrying out the present invention, but the scope of the invention is not limited to the following embodiments and illustrated examples.

The nozzle diameter of each nozzle provided in the electrostatic suction type liquid ejection device described in the following embodiments is preferably 30 [μm] or less, more preferably less than 20 [μm], and further preferably 10 [μm]. ], Preferably 8 [μm] or less, more preferably 4 [μm] or less. Further, the nozzle diameter is preferably larger than 0.2 [μm]. Hereinafter, the relationship between the nozzle diameter and the electric field intensity will be described below with reference to FIGS. Corresponding to FIGS. 1 to 6, the electric field intensity when the nozzle diameter is φ0.2, 0.4, 1, 8, 20 [μm] and the nozzle diameter φ50 [μm] conventionally used as a reference. Shows the distribution.

Here, in each drawing, the nozzle center position indicates the center position of the liquid ejection surface of the liquid ejection hole at the tip of the nozzle. (A) of each figure shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm], and (b) shows that the distance between the nozzle and the counter electrode is 100 [μm]. [μm] is shown. The applied voltage was constant at 200 [V] under each condition. The distribution line in the figure indicates the range of charge intensity from 1 × 10 ⁶ [V / m] to 1 × 10 ⁷ [V / m].

FIG. 7 is a table showing the maximum electric field strength under each condition.

か ら From FIGS. 1 to 6, it was found that when the nozzle diameter was φ20 [μm] or more (FIG. 5), the electric field intensity distribution spread over a wide area. Further, from the chart of FIG. 7, it was also found that the distance between the nozzle and the counter electrode affected the electric field strength.

From these facts, when the nozzle diameter is φ8 [μm] or less (FIG. 4), the electric field intensity concentrates, and the fluctuation of the distance between the opposing electrodes hardly affects the electric field intensity distribution. Therefore, if the nozzle diameter is φ8 [μm] or less, stable ejection can be performed without being affected by the positional accuracy of the counter electrode, the variation in the material properties of the base material, and the variation in the thickness.

Next, FIG. 8 shows the relationship between the nozzle diameter of the nozzle and the maximum electric field strength when there is a liquid level at the tip of the nozzle.

グ ラ フ From the graph shown in FIG. 8, it was found that when the nozzle diameter was φ4 [μm] or less, the electric field concentration became extremely large and the maximum electric field intensity could be increased. As a result, the initial ejection speed of the solution can be increased, so that the flight stability of the droplets can be increased, and the ejection responsiveness can be improved since the moving speed of the electric charge at the nozzle tip portion can be increased.

Next, the maximum chargeable amount of the discharged droplet will be described below. The amount of charge that can be charged on the droplet is expressed by the following equation (3) in consideration of the Rayleigh splitting (Rayleigh limit) of the droplet.

　ここで、ｑはレイリー限界を与える電荷量［Ｃ］、ε₀は真空の誘電率［Ｆ／ｍ］、γは溶液の表面張力［Ｎ／ｍ］、ｄ₀は液滴の直径［ｍ］である。

Here, q is the amount of charge [C] that gives the Rayleigh limit, ε ₀ is the dielectric constant of vacuum [F / m], γ is the surface tension of the solution [N / m], and d ₀ is the diameter of the droplet [m]. It is.

The closer the charge q obtained by the above formula (3) is to the Rayleigh limit value, the stronger the electrostatic force is, even at the same electric field strength, and the ejection stability is improved. Spraying of the solution occurs at the discharge hole, and the discharge stability is lacking.

Here, the nozzle diameter of the nozzle, the discharge start voltage at which the droplet discharged at the nozzle tip starts to fly, the voltage value at the Rayleigh limit of the initial discharge droplet, and the ratio of the discharge start voltage to the Rayleigh limit voltage value A graph showing the relationship is shown in FIG.

From the graph shown in FIG. 9, it is found that when the nozzle diameter is in the range of φ0.2 [μm] to φ4 [μm], the ratio of the discharge start voltage to the Rayleigh limit voltage exceeds 0.6, and the droplet charging efficiency is good. Thus, it was found that stable ejection can be performed in this range.

For example, in the graph shown in FIG. 10 showing the relationship between the nozzle diameter and the region of the strong electric field (1 × 10 ⁶ [V / m] or more) at the nozzle tip, when the nozzle diameter becomes φ0.2 [μm] or less. It is shown that the region of the electric field concentration becomes extremely narrow. This indicates that the droplet to be discharged cannot receive sufficient energy for acceleration and the flight stability is reduced. Therefore, it is preferable to set the nozzle diameter to be larger than φ0.2 [μm].

As shown in FIG. 11, the electrostatic suction type droplet discharge device according to the present embodiment has liquid chamber partitions 106, 106,... And liquid chamber partitions 107, 107,. An electro-suction type liquid discharge head 100, a supply pump (not shown) for applying a supply pressure of the solution to each solution supply channel 101 of the liquid discharge head 100, and a circuit for driving the liquid discharge head 100 (FIGS. 13 and 14) , The discharge voltage applying means 25 and the counter electrode 23).

First, the liquid ejection head 100 will be described with reference to FIG. Here, FIG. 11 is a perspective view showing the bottom surface of the liquid ejection head 100 on the near side of the paper surface and showing the liquid ejection head 100 partially cut away. As shown in FIG. 11, a liquid ejection head 100 includes a liquid chamber structure 102 in which a plurality of solution supply channels 101 as liquid chambers are formed, and a chargeable solution attached to the bottom of the liquid chamber structure 102. A nozzle plate 104 provided with an ultra-small diameter nozzle 103 that discharges from the tip as a droplet corresponding to each solution supply channel 101.

The liquid chamber structure 102 will be described. FIG. 12 is a sectional view mainly showing one solution supply channel 101 when the liquid chamber structure 102 is viewed from the bottom direction. As shown in FIGS. 11 and 12, the liquid chamber structure 102 has a liquid chamber side wall 105, and a plurality of first liquid chamber partition walls 106, 106, Are provided on the liquid chamber side wall 105 so as to be parallel to each other. A second liquid chamber partition 107 is stacked on each first liquid chamber partition 106, and the second liquid chamber partition 107 is bonded and fixed to the first liquid chamber partition 106 via an adhesive layer 108. Accordingly, a plurality of grooves are formed on the liquid chamber side wall 105 by arranging a plurality of pairs of the first liquid chamber partition walls 106 and the second liquid chamber partition walls 108 in parallel with each other. The cover plate 110 is bonded and fixed to the second liquid chamber side walls 107, 107,... Via an adhesive layer 109 so as to face the liquid chamber side wall 105 and cover the plurality of grooves. ing. Thereby, a plurality of solution supply channels 101 defined by the pair of first liquid chamber partition walls 106, the pair of second liquid chamber partition walls 107, the liquid chamber side walls 105, and the cover plate 110 are formed. On the bottom surface of the liquid chamber structure 102, the bottom of each solution supply channel 101 is open, and the solution supply channel 101 is closed by bonding and fixing a nozzle plate 104 described below to the bottom surface of the liquid chamber structure 102. In the nozzle plate 104, nozzles 103 are formed corresponding to the respective solution supply channels 101.

Each solution supply channel 101 is shallow near the upper end face 111 of the liquid chamber side wall 105, and a shallow groove 118 is formed near the upper end face 111. At the upper part of the cover plate 110, a liquid inlet 119 and a manifold 120 connected to the liquid inlet 119 are formed. Then, by covering each solution supply channel 101 with the cover plate 110, the upper end of each solution supply channel 101 is connected to the liquid supply source storing the solution via the manifold 120 and the liquid inlet 119. The liquid ejection head 100 is provided with a supply pump (solution supply means) (not shown) for applying a supply pressure of the solution to each of the solution supply channels 101. The solution is supplied to the solution supply channel 101. The supply pump supplies the solution while maintaining a supply pressure within a range where the solution does not spill out from the tip of the nozzle 103 described later.

A control electrode 121 is provided on the wall surfaces of the liquid chamber partition walls 106 and 107, and an insulating layer 125 is provided on the control electrode 121. The reason why the control electrode 121 is covered with the insulating layer 125 to make the inner wall of the solution supply channel 101 insulative is that a stroke is generated through a solution existing between the discharge electrode 142 of the nozzle plate 104 and the control electrode 121 described later. This is to prevent The material and thickness of the insulating layer 125 need to be determined in consideration of the conductivity of the solution and the applied voltage. As the insulating layer 125, a film formed of a parylene resin by a vapor deposition method or a film formed of a SiO ₂ or Si ₃ N ₄ film by a CVD method is appropriate.

A conductive pattern 123 corresponding to each solution supply channel 101 is formed on a drive substrate 122 attached to a surface opposite to the surface of the liquid chamber side wall 105 in which the first liquid chamber side wall 106 is provided. And the control electrode 121 are connected by a conducting wire 124 by a wire bonding method.

The liquid chamber partition walls 106 and 107 are piezoelectric ceramic plates, which are made of a ferroelectric lead zirconate titanate (PZT) piezoelectric ceramic material, and are polarized in the laminating direction and in directions opposite to each other. The liquid chamber partition walls 106 and 107 are deformed when a voltage is applied to the control electrode 121, and a pressure is applied to the solution in the solution supply channel 101. No liquid droplets are ejected from the tip of the nozzle 103, and only a convex meniscus protruding outward from the tip of the nozzle 103 is formed. That is, the liquid chamber partition walls 106, 106,... And the liquid chamber partition walls 107, 107,. It is composed.

Next, the nozzle plate 104 will be described. FIG. 13 is a bottom view of the nozzle plate 104, and FIG. 14 is a cross-sectional view of the nozzle plate 104 cut along a cutting line AA '. The nozzle plate 104 includes an electrically insulating substrate 141 serving as a base, a plurality of ejection electrodes 142 formed on a surface 141a of the substrate 141, and a plurality of ejection electrodes 142, 142,. And a nozzle layer 143 laminated on the entire surface 141a.

(4) The back surface 142b of the substrate 141 is fixed to the bottom surface of the liquid chamber structure 102 via an adhesive or the like. Are formed in the substrate 141. The through holes 141c, 141c,... Are arranged so as to correspond to the solution supply channels 101, respectively. It communicates with 101. That is, the through hole 141c forms the lower part of the solution supply channel 101.

Are formed to correspond to the respective through holes 141c. Each discharge electrode 142 is formed on the surface 141a of the substrate 141 so as to cover the corresponding through hole 141c, and when viewed from the bottom, each discharge electrode 142 overlaps the corresponding through hole 141c. That is, each ejection electrode 142 faces the corresponding solution supply channel 101 and forms the bottom surface of the corresponding solution supply channel 101. The discharge electrode 142 has a through hole 142a formed at a portion overlapping the through hole 141c, and the through hole 142a communicates with the corresponding solution supply channel 101. In addition, wirings 144 formed integrally are connected to the respective ejection electrodes 142, and the respective wirings 144 are connected to a bias power supply 30 described later. In the drawing, the discharge electrode 142 has a ring shape and the wiring 144 has a square shape when viewed from the bottom, but the present invention is not limited to such a shape.

A plurality of nozzles 103, 103,... Are integrally formed in the nozzle layer 143, and the plurality of nozzles 103, 103,. Each nozzle 103 is formed so as to stand substantially perpendicularly to the substrate 141 (to hang down). The nozzles 103 are arranged so as to correspond to the solution supply channels 101, and each nozzle 103 overlaps the corresponding through hole 141c when viewed from the bottom. Each of the nozzles 103 is formed with an in-nozzle flow path 145 penetrating from the tip of the nozzle 103 along the center line thereof. A nozzle hole 103 a which is the end of the in-nozzle flow path 145 is formed at the tip of each nozzle 103. ing. The in-nozzle flow path 145 communicates with the corresponding solution supply channel 101 through the through hole 142a of the discharge electrode 142, and the discharge electrode 142 faces the in-nozzle flow path 145. The solution supplied to each solution supply channel 101 is also supplied to the through-hole 141 c and the inside of the nozzle channel 145, and directly contacts the discharge electrode 142 in each of the solution supply channel 101 and each of the nozzle channels 145. In the drawings, a plurality of nozzles 103 are arranged in one row, but may be arranged in two or more rows or in a matrix.

The nozzle layer 143 including these nozzles 103, 103,... Has electrical insulation, and the inner surface of the nozzle flow path 145 also has electrical insulation. Further, the nozzle layer 143 including these nozzles 103, 103,... May have water repellency (for example, the nozzle layer 143 is formed of a resin containing fluorine), or the nozzles 103, 103. A water-repellent film having a water-repellent property may be formed on the surface layer (for example, a metal film is formed on the surfaces of the nozzles 103, 103,..., And the metal and the water-repellent resin are further formed on the metal film). A water-repellent layer is formed by eutectoid plating.) Here, the water repellency is a property that repels a solution discharged from the nozzle 103. The water repellency of the nozzle layer 143 can be controlled by selecting a water repellent treatment method according to the solution. Examples of the water-repellent treatment method include electrodeposition of a cationic or anionic fluororesin, application of a fluoropolymer, a silicone resin, polydimethylsiloxane, sintering, eutectoid plating of a fluoropolymer, and amorphous. Alloy thin film deposition method, method of depositing a film of organosilicon compound mainly composed of polydimethylsiloxane or fluorine-containing silicon compound formed by plasma polymerization of hexamethyldisiloxane as a monomer by plasma CVD method There is.

さ ら に Each nozzle 103 will be described in more detail. The nozzle 103 has a uniform opening diameter at the tip and the nozzle flow path 22, and as described above, these are formed with a very small diameter. The shape of the nozzle 103 is sharply formed at the distal end so that the diameter becomes smaller toward the distal end, and is formed as a truncated cone that is almost conical. To give an example of specific dimensions of each part, the internal diameter of the nozzle flow path 145 is 30 [μm] or less, further less than 20 [μm], further 10 [μm] or less, further 8 [μm] or less. It is preferably 4 [μm] or less, and in this embodiment, the internal diameter of the nozzle flow path 145 is set to 1 [μm]. The outer diameter at the tip of the nozzle 103 is set at 2 [μm], the diameter at the root of the nozzle 103 is set at 5 [μm], and the height of the nozzle 103 is set at 100 [μm].

The dimensions of the nozzle 103 are not limited to the above example. In particular, the inner diameter of the nozzle is in a range in which a discharge voltage capable of discharging a droplet by the effect of electric field concentration described below is less than 1000 [V], and is, for example, 70 [μm] or less. Desirably, the lower limit value is a diameter of 20 [μm] or less, which is a range in which it is feasible to form a through-hole through which a solution passes by the current nozzle forming technology. It is desirable that the shapes of the nozzles 103 are the same, but they may be different.

The shape of the nozzle internal flow path 145 does not have to be formed in a straight line having a constant inner diameter as shown in FIG. For example, as shown in FIG. 15A, the cross-sectional shape of the end portion of the in-nozzle channel 145 on the solution supply channel 101 side may be rounded. Further, as shown in FIG. 15B, the inner diameter of the end of the flow path 145 on the side of the solution supply channel 101 is set to be larger than the inner diameter of the end on the discharge side, and the inner surface of the flow path 145 in the nozzle. May be formed in a tapered peripheral surface shape. Further, as shown in FIG. 15 (C), only the end of the in-nozzle flow path 145 on the solution supply channel 101 side described later is formed in a tapered peripheral surface shape, and the discharge end side of the tapered peripheral surface is closer to the discharge end side. It may be formed in a straight line having a constant inner diameter.

Next, a circuit configuration for driving the liquid ejection head 100 will be described. The circuit for driving the liquid ejection head 100 includes an ejection voltage applying means 25 (shown in FIG. 13 for convenience) for individually applying an ejection voltage to the ejection electrodes 142, 142,..., And the nozzles 103, 103,. And an opposing electrode 23 (shown in FIG. 14) that supports a base material 200 that receives the landing of the droplet on the opposing surface 23a.

The ejection voltage applying means 25 includes a bias power supply 30 for applying a DC bias voltage to the ejection electrode 142 and an ejection power supply 29 for applying a pulse voltage superimposed on the bias voltage to a potential required for ejection to the ejection electrode 142. It is provided corresponding to each ejection electrode 142. The bias power supply 30 and the discharge power supply 29 may be common to all the discharge electrodes 142, 142,..., But in this case, the discharge power supply 29 applies a pulse voltage individually to the discharge electrodes 142, 142,.

The bias voltage by the bias power supply 30 is always applied within a range in which the solution is not ejected, so that the width of the voltage to be applied at the time of ejection is reduced in advance, thereby improving the reactivity at the time of ejection. I have.

The discharge voltage power supply 29 applies the pulse voltage to the bias voltage and applies the discharge electrodes 142, 142,... Individually only when the solution is discharged. At this time, the value of the pulse voltage is set so that the superimposed voltage V satisfies the following condition.

　ただし、γ：溶液の表面張力［Ｎ／ｍ］、ε₀：真空の誘電率［Ｆ／ｍ］、ｄ：ノズル直径［ｍ］、h：ノズル−基材間距離［ｍ］、ｋ：ノズル形状に依存する比例定数（１．５＜ｋ＜８．５）とする。

Here, γ: surface tension of the solution [N / m], ε ₀ : dielectric constant of vacuum [F / m], d: nozzle diameter [m], h: distance between nozzle and substrate [m], k: nozzle The proportional constant (1.5 <k <8.5) depends on the shape.

By way of example, the bias voltage is applied at DC 300 [V] and the pulse voltage is marked at 100 [V]. Therefore, the superimposed voltage at the time of ejection is 400 [V].

The opposing electrode 23 has an opposing surface 23a perpendicular to the nozzles 103, 103,..., And supports the substrate 200 along the opposing surface 23a. The distance from the tips of the nozzles 103, 103,... To the opposing surface 23a of the opposing electrode 23 is set to 100 [μm] as an example.

(4) Since the counter electrode 23 is grounded, it always maintains the ground potential. Therefore, when the pulse voltage is applied, the discharged liquid droplets are guided to the counter electrode 23 side by electrostatic force due to an electric field generated between the tip of each nozzle 103 and the opposing surface 23a.

Since the liquid discharge head 100 discharges droplets by increasing the electric field strength by the electric field concentration at the tip of each of the nozzles 103, 103,... Although it is possible to discharge droplets without guidance by the counter electrode 23, it is desirable that guidance by electrostatic force be performed between the nozzles 103, 103,... And the counter electrode 23. It is also possible to release the charge of the charged droplet by grounding the counter electrode 23.

The solution supplied to the liquid discharge head 100 and discharged from the liquid discharge head 100 will be described.

Examples of the solution include water, COCl ₂ , HBr, HNO ₃ , H ₃ PO ₄ , H ₂ SO ₄ , SOCl ₂ , SO ₂ Cl ₂ , and FSO ₃ H as the inorganic liquid. As the organic liquid, methanol, n-propanol, isopropanol, n-butanol, 2-methyl-1-propanol, tert-butanol, 4-methyl-2-pentanol, benzyl alcohol, α-terpineol, ethylene glycol, glycerin, Alcohols such as diethylene glycol and triethylene glycol; phenols such as phenol, o-cresol, m-cresol, and p-cresol; dioxane, furfural, ethylene glycol dimethyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol, and butyl Ethers such as carbitol, butyl carbitol acetate, epichlorohydrin; acetone, methyl ethyl ketone, 2-methyl-4-pentanone, acetoacetate Ketones such as enone; fatty acids such as formic acid, acetic acid, dichloroacetic acid and trichloroacetic acid; methyl formate, ethyl formate, methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, 3-methoxybutyl acetate, and acetic acid n-pentyl, ethyl propionate, ethyl lactate, methyl benzoate, diethyl malonate, dimethyl phthalate, diethyl phthalate, diethyl carbonate, ethylene carbonate, propylene carbonate, cellosolve acetate, butyl carbitol acetate, ethyl acetoacetate, cyanoacetic acid Esters such as methyl and ethyl cyanoacetate; nitromethane, nitrobenzene, acetonitrile, propionitrile, succinonitrile, valeronitrile, benzonitrile, ethylamine, diethylamine, ethylenediamine, aniline, N-methylaniline, N, N-dimethylaniline, o-toluidine, p-toluidine, piperidine, pyridine, α-picoline, 2,6-lutidine, quinoline, propylenediamine, formamide, N-methylformamide, N, N-dimethylformamide, N, Nitrogen-containing compounds such as N-diethylformamide, acetamido, N-methylacetamido, N-methylpropionamide, N, N, N ', N'-tetramethylurea, N-methylpyrrolidone; and dimethylsulfoxide, sulfolane and the like. Sulfur compounds; hydrocarbons such as benzene, p-cymene, naphthalene, cyclohexylbenzene, and cyclohexene; 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,1,2- Tetrachloroethane, 1,1,2,2-tetrachloro Loethane, pentachloroethane, 1,2-dichloroethylene (cis-), tetrachloroethylene, 2-chlorobutane, 1-chloro-2-methylpropane, 2-chloro-2-methylpropane, bromomethane, tribromomethane, 1-bromopropane, etc. Halogenated hydrocarbons, and the like. Alternatively, two or more of the above liquids may be mixed and used as a solution.

Further, when a conductive paste containing a large amount of a substance having high electric conductivity (silver powder or the like) is used as a solution and the liquid is ejected, the above-described target substance to be dissolved or dispersed in the liquid is a nozzle. There is no particular limitation except for coarse particles that cause clogging. As a phosphor such as PDP, CRT, and FED, a conventionally known phosphor can be used without any particular limitation. For example, as a red phosphor, (Y, Gd) BO ₃ : Eu, YO ₃ : Eu, etc., and as a green phosphor, Zn ₂ SiO ₄ : Mn, BaAl ₁₂ O ₁₉ : Mn, (Ba, Sr, Mg) O -Blue phosphors such as α-Al ₂ O ₃ : Mn include BaMgAl ₁₄ O ₂₃ : Eu and BaMgAl ₁₀ O ₁₇ : Eu. It is preferable to add various binders in order to firmly adhere the above-mentioned target substance onto the recording medium. Examples of the binder used include celluloses such as ethyl cellulose, methyl cellulose, nitrocellulose, cellulose acetate, and hydroxyethyl cellulose and derivatives thereof; alkyd resins; polymethacrylic acid, polymethyl methacrylate, 2-ethylhexyl methacrylate-methacrylic acid copolymer. (Meth) acrylic resin and its metal salt such as lauryl methacrylate / 2-hydroxyethyl methacrylate copolymer; poly (meth) acrylamide resin such as poly N-isopropylacrylamide and poly N, N-dimethylacrylamide; polystyrene, acrylonitrile Styrene resins such as styrene copolymer, styrene / maleic acid copolymer, styrene / isoprene copolymer; styrene / n-butyl methacrylate Styrene and acrylic resins such as copolymers; saturated and unsaturated polyester resins; polyolefin resins such as polypropylene; halogenated polymers such as polyvinyl chloride and polyvinylidene chloride; polyvinyl acetate, vinyl chloride and vinyl acetate Polyvinyl resins such as polymers; Polycarbonate resins; Epoxy resins; Polyurethane resins; Polyacetal resins such as polyvinyl formal, polyvinyl butyral, and polyvinyl acetal; Polyethylene such as ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer resin Amide resins such as benzoguanamine; urea resins; melamine resins; polyvinyl alcohol resins and their anionic cationic modifications; polyvinyl pyrrolidone and its copolymers; Homopolymers, copolymers and crosslinked products of alkylene oxides such as polyethylene oxide; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyether polyols; SBR, NBR latex; dextrin; sodium alginate; gelatin and its derivatives; Natural or semi-synthetic resins such as tragacanth gum, pullulan, gum arabic, locust bean gum, guar gum, pectin, carrageenan, glue, albumin, various starches, corn starch, konjac, seaweed, agar, soybean protein; terpene resins; ketone resins; Rosin and rosin ester; polyvinyl methyl ether, polyethylene imine, polystyrene sulfonic acid, polyvinyl sulfonic acid, and the like can be used. These resins may be used not only as a homopolymer but also as a blend within a compatible range.

場合 When the liquid ejection device of the present embodiment is used as a patterning method, it can be typically used for display purposes. Specifically, formation of a phosphor of a plasma display, formation of a rib of a plasma display, formation of an electrode of a plasma display, formation of a phosphor of a CRT, formation of a phosphor of a field emission display (FED), formation of a rib of an FED , A liquid crystal display color filter (RGB color layer, black matrix layer), a liquid crystal display spacer (a pattern corresponding to the black matrix, a dot pattern, and the like). The rib referred to here generally means a barrier, and is used to separate plasma regions of each color in a plasma display as an example. Other applications include microlenses, patterning application of magnetic materials, ferroelectrics, and conductive pastes (wiring and antennas) for semiconductor applications, and normal printing and special media (films, fabrics, steel plates, etc.) for graphic applications ), Curved surface printing, printing plates of various printing plates, application using this embodiment such as adhesives and sealing materials for processing applications, and pharmaceuticals for bio and medical applications (mixing a plurality of trace components) ), Application of a sample for genetic diagnosis and the like.

Next, a method for manufacturing the liquid ejection head 100 will be described.

To manufacture the liquid ejection head 100, the liquid chamber structure 102 and the nozzle plate 104 may be manufactured separately, and then the nozzle plate 104 may be bonded and fixed to the bottom surface of the liquid chamber structure 102.

In order to manufacture the liquid chamber structure 102, first, a zirconate titanate (PZT) piezoelectric material constituting the liquid chamber side wall 105, the first liquid chamber partition wall 106, and the second liquid chamber partition wall 107 will be described. Is prepared and formed into a sheet having a predetermined thickness by using a method such as a doctor blade method or a screen printing method.

Then, a piezoelectric laminate is formed by laminating a pair of sheets using an adhesive that becomes the adhesive layer 108, and thereafter, a polarization process is performed by a well-known method, whereby the upper sheet and the lower sheet are Are polarized in the thickness direction and in directions opposite to each other.

Then, the piezoelectric laminate obtained by grinding a piezoelectric laminate formed by laminating a pair of sheets using a tool (not shown) (for example, a diamond blade), thereby forming a solution supply channel 101 in the piezoelectric laminate. A plurality of grooves are formed parallel to each other.

(4) Thereafter, electrodes are formed on the liquid chamber partition walls 106 and 107 constituting the grooves by a known method such as plating. No electrode is formed on the bottom surface of the groove. Then, an adhesive to be the adhesive layer 109 is applied to the upper portion of the second liquid chamber partition 107 and the cover plate 110 is attached to the liquid chamber structure 102 in which a plurality of solution supply channels 101 are formed in parallel with each other. Is manufactured. Then, the drive substrate 122 is attached to the liquid chamber side wall 105, and one end of the conducting wire 124 is joined to each electrode 11, and the other end of the conducting wire 124 is joined to the wiring pattern 123.

On the other hand, in order to manufacture the nozzle plate 104, as shown in FIG. 16, first, a flat substrate 141 is prepared (at this time, a plurality of through holes 141c, 141c,... Are not yet formed in the substrate 141). .), A conductive film 142 ′ is formed on the entire surface 141 a of the substrate 141 by a film forming method such as a PVD method, a CVD method, and a plating method, and resists 150, 150,... Are formed on the conductive film 142 ′ by a photolithographic method. To form Here, the shape of the resist 150 in a plan view is a shape in which the ejection electrode 142 and the wiring 144 are combined in a bottom view. Note that the substrate 141 may be a glass substrate, a silicon wafer, or a resin substrate, but has an insulating property.

Next, when the conductive film 142 ′ is etched using the resists 150, 150,... As a mask, the conductive film 142 ′ is shaped and the plurality of ejection electrodes 142, 142,. After that, the resists 150, 150,... Are removed (FIG. 17). Since the plurality of discharge electrodes 142, 142,... Are collectively formed through the film forming step, the masking step, and the shape processing step, the production efficiency of the nozzle plate 104 is high.

Next, a resist layer (photosensitive resin layer) 143 'is formed on the entire surface 141a of the substrate 141 so as to cover all of the ejection electrodes 142, 142,... And the wirings 144, 144,. 18). The resist layer 143 'may be of a positive type or a negative type. The resist layer 143 'is made of a photosensitive resin, and its composition is preferably PMMA, SU8, or the like.

(4) Next, exposure is performed by an electron beam, a femtosecond laser, or the like according to the shape of the plurality of nozzles 103 to form the resist layer 143 '. That is, when the resist layer 143 'is of a positive type, a portion of the resist layer 143' overlapping the through hole 142a of the discharge electrode 142, 142,. The part in between is exposed to the middle layer. On the other hand, when the resist layer 143 'is of a negative type, portions of the resist layer 143' that become the plurality of nozzles 103 are exposed. Here, instead of exposing the resist layer 143 'with an electron beam or a femtosecond laser, the resist layer 143' may be exposed with a visible light, an ultraviolet ray, an excimer laser, an i-line, a g-line, or the like. That is, the electromagnetic wave (light in a broad sense) used for photosensitization may be anything that exposes the resist layer 143 '.

Next, by applying a developing solution to the resist layer 143 ′, the resist layer 143 ′ is removed in a shape corresponding to the exposure, and a plurality of nozzles 103, 103,. (FIG. 19). In FIG. 19, the nozzle has a conical shape or a truncated conical shape, but may have a flat shape that does not protrude.

Here, when the resist layer 143 'is a positive photosensitive resin, the irradiation energy is large on the surface side of the exposed resist layer 143', and conversely, the irradiation energy decreases toward the substrate 141 side. , The solubility in the developing solution decreases toward the substrate 141 side. Therefore, when the resist layer 143 'is of the positive type, the nozzles 103, 103, 103,... Having a substantially conical or truncated cone shape having a larger diameter toward the substrate 141 side can be formed more easily. Further, since the plurality of nozzles 103, 103,... Are formed collectively only by forming the resist layer 143 'and then exposing and developing the resist layer 143', the production efficiency of the liquid discharge head is high.

Next, a resist film 151 is formed on the back surface 141b of the substrate 141 by photolithography (FIG. 20). Here, the shape of the resist film 151 when viewed in a plan view is a shape that is open at a portion to be the through holes 141c, 141c,. Then, when the substrate 141 is etched using the resist film 151 as a mask, a plurality of through holes 141c, 141c,... Are formed in the substrate 141, and then the resist film 151 is removed (FIG. 21). Thereby, the nozzle plate 104 is manufactured.

.. Formed in the substrate 141 are opposed to the respective solution supply channels 101 of the liquid chamber structure 102, and the back surface 141b of the substrate 141 is bonded to the bottom surface of the liquid chamber structure 102 with an adhesive or the like. (FIG. 21). Also, a bias power supply 30 and an ejection voltage power supply 29 are electrically connected to the wirings 144, 144,. Thereby, the liquid ejection head 100 is manufactured.

The surface layers of the nozzles 103 may be subjected to a water-repellent treatment as necessary. For example, the surface layer of the nozzles 103 may be made water-repellent by forming the resist layer 143 ′ with a water-repellent photosensitive resin (for example, a fluorine-containing photosensitive resin). , 103,... Are formed, a metal film (for example, Ni, Au, Pt, etc.) is formed on the surface of the nozzle 103 in a state where the respective nozzle holes 103a are masked with a resist. By forming a water-repellent film formed by eutectoid plating, the surface layers of the nozzles 103 may be made water-repellent (resist masking the nozzle holes 103a is removed last). The water-repellent photosensitive resin is a PTFE or FEP dispersion having an average particle diameter of about 0.2 μm or a CYTOP manufactured by Asahi Glass Co., Ltd. in which a fluororesin is dissolved in a perfluorosolvent. It refers to a dispersion mixed by 10%, and in dispersion, FEP having a lower melting point is preferred. In addition, examples of the dispersion include MDF FEP 120-J (54 wt%, water dispersion) manufactured by DuPont, and Fluon XAD911 (60 wt%, water dispersion) manufactured by Asahi Glass Co., Ltd. Further, the resist polymer for F2 lithography is also a fluorine-containing photosensitive resin, and may be one in which fluorine is introduced into a polymer main chain or one in which fluorine is introduced into a side chain.

Since the nozzles 103, 103,... Are formed only by exposing and developing the resist layer 143 'as in the above manufacturing method, flexibility in the shape of the nozzle 103, manufacturing cost, and compatibility with a long line head Is advantageous. For example, in order to manufacture a head as disclosed in Japanese Patent Application Laid-Open No. 2001-68827, a micro hole is formed in a silicon substrate based on the silicon substrate. Is more convenient, the manufacturing method of the present embodiment is more advantageous in manufacturing a long line head, and the manufacturing cost of the head 100 is considered to be more advantageous in the present embodiment.

Next, a method of driving the liquid ejection head 100 and a droplet ejection operation of the liquid ejection head 100 will be described. FIG. 22 is an explanatory diagram showing the relationship between the solution discharging operation and the voltage applied to the solution. FIG. 22 (A) shows a state in which discharging is not performed, and FIG. 22 (B) shows a discharging state.

The supply pump supplies a chargeable solution to the in-nozzle flow paths 145 of the respective nozzles 103 via the liquid inlet 119 and the manifold 120, and in this state, the respective discharge power is supplied by the respective bias power supplies 30. A bias voltage is applied to the solution via 142. In this state, the solution is charged, and a concave meniscus is formed at the tip of each nozzle 103 by the solution (FIG. 22A).

Among the nozzles 103, 103,..., The pulse voltage is applied to the solution by the ejection voltage power supply 29 via the ejection electrode 142, and the control electrode is synchronized with the pulse voltage. A pulse voltage is also applied to 121. When a pulse voltage is applied to the control electrode 121, the liquid chamber partition walls 106 and 107 expand, and the volume of the solution supply channel 101 decreases, thereby increasing the pressure of the solution in the solution supply channel 101. Therefore, a convex meniscus protruding outward is formed at the tip of the nozzle 103. Further, since the pulse voltage is applied to the ejection electrode 142 almost simultaneously with the application of the pulse voltage to the control electrode 121, the electric field is concentrated by the apex of the convex meniscus projecting to the outside, and finally the surface tension of the solution is increased. Micro droplets are ejected to the counter electrode side against the pressure (FIG. 22B).

When the pulse voltage applied to the discharge electrode 142 ends and the pulse voltage applied to the control electrode 121 ends, the volume of the solution supply channel 101 increases, so that the solution becomes concave at the tip of the nozzle 103. A concave meniscus is formed, and the solution is supplied to the nozzle channel 145 of the nozzle 103 that has discharged the liquid via the liquid inlet 119 and the manifold 120.

In the above description, when the pulse voltage is applied to the control electrode 121, the liquid chamber partition walls 106 and 107 expand and the volume of the solution supply channel 101 increases, but the pulse voltage is applied to the control electrode 121. As a result, the liquid chamber partition walls 106 and 107 may be contracted to operate such that the volume of the solution supply channel 101 is reduced. However, in this case, the pulse voltage is not applied to the control electrode 121 when the pulse voltage is applied to the ejection electrode 142 at the time of ejection, and the bias voltage is applied to the ejection electrode 142 when the ejection is not performed. Sometimes a pulse voltage is applied to the control electrode 121. As another head driving method, the fact that the discharge voltage varies depending on the meniscus position of the nozzle 103 is used, and a voltage V ₀ that does not discharge is applied to the discharge electrode 142 at a position where the meniscus is lower than the tip of the nozzle 103. By changing the volume of the solution supply channel 101 by applying a pulse voltage to 121, the discharge can be controlled by controlling the meniscus position discharged from the tip of the nozzle 103 capable of discharging at the voltage V ₀ .

In addition, a convex meniscus is formed by applying pressure to the solution in the solution supply channel 101 at the time of discharge by the liquid chamber partition walls 106 and 107 which are piezoelectric elements. However, the solution in the solution supply channel 101 is formed by a heater or the like. A convex meniscus may be formed by applying pressure to the solution by boiling the film at the time of ejection. Since the convex meniscus forming means changes the pressure of the solution in the nozzle flow path 145, any method may be used as long as the volume of the solution supply channel 101 is changed, and the partition wall of the solution supply channel 101 is bent by electrostatic force. Alternatively, an electrostatic suction method that changes the volume is also possible. The ejection may be performed without forming the convex meniscus. However, it is advantageous to form and eject the convex meniscus in terms of safety and control cost in terms of constant ejection voltage and droplet ejection control. is there.

As a method of using the liquid ejection head 100, for example, the liquid ejection head 100 (mainly, the liquid chamber structure 102 and the nozzle plate 104) is positioned relative to the substrate 200 in a plane parallel to the substrate 200. By selectively ejecting droplets from the tips of the respective nozzles 103 while moving, a pattern in which droplets that have landed on the surface of the substrate 200 become dots is formed on the surface of the substrate 200. Since the plurality of nozzles 103, 103,... Are arranged in a row, the base material 200 is moved in a direction perpendicular to the row of the nozzles 103, 103,. By selectively discharging droplets from the front end, a pattern in which droplets that have landed on the surface of the base material 200 become dots can be formed on the surface of the base material 200. Since the liquid ejection head 100 is provided with a plurality of nozzles 103, a pattern can be formed quickly. In addition, the liquid discharge head 100 includes a circuit wiring pattern formation, a metal ultrafine particle wiring pattern formation, a carbon nanotube and its precursor and a catalyst array, a ferroelectric ceramics and its precursor patterning, It can be used for any of high orientation of polymer and its precursor, zone refining, microbead manipulation, active tapping, and formation of three-dimensional structure.

As described above, since the liquid discharge head 100 discharges droplets using the nozzle 103 having a very small diameter, which is not available in the related art, the electric field is concentrated by the charged solution in the nozzle flow path 145, and the electric field intensity is reduced. Enhanced. For this reason, in a nozzle having a structure in which the electric field is not concentrated as in the related art (for example, an inner diameter of 100 [μm]), the voltage required for ejection becomes too high, and a nozzle with a small diameter is considered to be virtually impossible to eject. , It is possible to discharge the solution at a lower voltage than before.

Because of the small diameter, it is possible to easily perform control to reduce the discharge flow rate per unit time due to the low nozzle conductance, and to achieve a sufficiently small droplet diameter without narrowing the pulse width (see above). According to each condition, the solution is discharged at 0.8 [μm].

Furthermore, since the ejected droplets are charged, the vapor pressure is reduced even for minute droplets, and by suppressing evaporation, the loss of droplet mass is reduced and flight is stabilized. In addition, it is possible to prevent a drop in landing accuracy of the droplet.

Furthermore, since the surface layers of the nozzles 103, 103,... Have water repellency, the solution in the nozzles 103, 103,. Also, since the surface layers of the nozzles 103, 103,... Have water repellency, the solution does not adhere to the vicinity of the nozzle holes 103a, and does not adversely affect the ejection of the droplets. Since the surface layers of the nozzles 103, 103,... Have water repellency, a meniscus formed at the time of ejection is formed in a beautiful convex shape, and droplets are ejected stably.

Further, since a pressure is applied to the solution in the nozzle 103 almost simultaneously with the application of the pulse voltage to the solution in each nozzle 103, even if the pulse voltage applied to the ejection electrode 142 is a low voltage, Drops are ejected. That is, it is possible to discharge the solution with a nozzle having a small diameter, which has been considered to be practically impossible to discharge due to an excessively high voltage required for discharge, at a lower voltage than in the past.

In order to obtain an electrowetting effect on the nozzle 103, an electrode (for example, the above-described metal film formed under the water-repellent film) is provided on the outer periphery of the nozzle 103, or the flow path 145 in the nozzle. May be provided on the inner surface of the substrate and covered with an insulating film from above. By applying a voltage to this electrode, the wettability of the inner surface of the nozzle channel 145 can be increased by the electrowetting effect on the solution to which the voltage is applied by the discharge electrode 142, The solution can be smoothly supplied to the flow path 145, and the ejection can be performed satisfactorily, and the response of the ejection can be improved.

Further, the ejection voltage applying means 25 constantly applies a bias voltage to each ejection electrode 142 and performs ejection of droplets by using a pulse voltage as a trigger. The discharge may be performed by applying a continuous rectangular wave and switching the level of the frequency. In order to discharge droplets, solution charging is indispensable, and even if a discharge voltage is applied at a frequency higher than the speed at which the solution is charged, discharge is not performed, and if the frequency is changed to a frequency at which the solution can be charged sufficiently Discharge is performed. Therefore, when the discharge is not performed, the discharge voltage is applied at a frequency higher than the dischargeable frequency, and the discharge of the solution is controlled by performing control to reduce the frequency to a frequency band in which the discharge can be performed only when the discharge is performed. Becomes possible. In such a case, there is no change in the potential itself applied to the solution, so that it is possible to further improve the time responsiveness and thereby improve the landing accuracy of the droplet.

[Theoretical explanation of electrostatic suction type liquid ejection device]
Previously, it was considered impossible to discharge droplets beyond the range defined by the following conditional expression.

　ここで、λ_Cは静電吸引力によりノズル先端部からの液滴の吐出を可能とするための溶液液面における成長波長［ｍ］であり、λ_C＝2πγh²/ε₀V²で求められる。

Here, λ _C is the growth wavelength [m] on the solution surface for enabling the droplet to be ejected from the tip of the nozzle by the electrostatic attraction force, and is obtained by λ _C = 2πγh ² / ε ₀ V ² Can be

　本発明では、静電吸引型インクジェット方式において果たすノズルの役割を再考察し、従来吐出不可能として試みられていなかった領域において、マクスウェル力などを利用することで、微小液滴を形成することができる。

In the present invention, the role of the nozzles played in the electrostatic suction type inkjet method is reconsidered, and it is possible to form minute droplets by utilizing Maxwell force or the like in a region which has not been conventionally attempted as impossible ejection. it can.

(4) Formulas that approximately represent the discharge conditions and the like for measures to realize such a drive voltage reduction and micro-volume discharge are described below.

The following description is applicable to the electrostatic suction type liquid ejection device described in each embodiment of the present invention.

Now, it is assumed that the conductive solution is injected into the nozzle of the inside d, and the nozzle is positioned perpendicular to the height of h from the infinite plate conductor as the base material. This is shown in FIG. At this time, it is assumed that the electric charge induced at the nozzle tip concentrates on the hemisphere at the nozzle tip, and is approximately represented by the following equation.

　ここで、Ｑ：ノズル先端部に誘起される電荷［Ｃ］、ε₀：真空の誘電率［Ｆ／ｍ］、ε：基材の誘電率［Ｆ／ｍ］、h：ノズル−基材間距離［ｍ］、ｒ：ノズル内部の直径の半径［ｍ］、Ｖ：ノズルに印加する総電圧［Ｖ］である。α：ノズル形状などに依存する比例定数で、1〜1.5程度の値を取り、特にｄ≪ｈのときほぼ1程度となる。

Here, Q: electric charge [C] induced at the tip of the nozzle, ε ₀ : dielectric constant of vacuum [F / m], ε: dielectric constant of substrate [F / m], h: between nozzle and substrate Distance [m], r: radius [m] of the diameter inside the nozzle, V: total voltage [V] applied to the nozzle. α: a proportional constant depending on the nozzle shape and the like, and takes a value of about 1 to 1.5, and becomes about 1 particularly when d≪h.

{Circle around (2)} When the substrate as the base material is a conductive substrate, it is considered that mirror image charges Q ′ having opposite signs are induced at symmetric positions in the substrate. When the substrate is an insulator, the image charge Q ′ having the opposite sign is similarly induced at a symmetric position determined by the dielectric constant.

で与えられる。ここでｋ：比例定数で、ノズル形状などにより異なるが、1.5〜8.5程度の値をとり、多くの場合5程度と考えられる。（P. J. Birdseye and D.A.Smith, Surface Science, 23 (1970) 198-210）。 By the way, the electric field intensity E _loc. [V / m] at the tip of the convex meniscus at the nozzle tip is assuming that the radius of curvature of the convex meniscus tip is R [m].

Given by Here, k is a proportional constant, which varies depending on the nozzle shape and the like, but takes a value of about 1.5 to 8.5, and is considered to be about 5 in many cases. (PJ Birdseye and DASmith, Surface Science, 23 (1970) 198-210).

For the sake of simplicity, let d / 2 = R. This corresponds to a state in which the conductive solution is swelled into a hemispherical shape having the same radius as the radius of the nozzle at the nozzle tip due to surface tension.

（７）、（８）、（９）式よりα＝１とおいて、

と表される。 Consider the balance of the pressure acting on the liquid at the nozzle tip. First, as for the electrostatic pressure, if the liquid area at the nozzle tip is S [m ² ],

From equations (7), (8) and (9), setting α = 1,

It is expressed as

　ここで、γ：表面張力［Ｎ／ｍ］、である。
静電的な力により流体の吐出が起こる条件は、静電的な力が表面張力を上回る条件なので、 On the other hand, if the surface tension of the liquid at the nozzle tip is P _S ,

Here, γ: surface tension [N / m].
The condition under which the ejection of fluid occurs due to the electrostatic force is a condition where the electrostatic force exceeds the surface tension.

となる。十分に小さいノズル径をもちいることで、静電的な圧力が、表面張力を上回らせる事が可能である。
この関係式より、Ｖとｄの関係を求めると、

が吐出の最低電圧を与える。すなわち、式（６）および式（１３）より、

が、本発明の実施形態における動作電圧となる。

It becomes. By using a sufficiently small nozzle diameter, the electrostatic pressure can exceed the surface tension.
When the relationship between V and d is obtained from this relational expression,

Gives the lowest voltage for ejection. That is, from Equations (6) and (13),

Is the operating voltage in the embodiment of the present invention.

FIG. 9 shows the dependence of the discharge limit voltage Vc on the nozzle having a certain radius d. From this figure, it was clarified that, considering the concentration effect of the electric field by the minute nozzle, the discharge start voltage decreases as the nozzle diameter decreases.

In the conventional concept of an electric field, that is, when only the electric field defined by the voltage applied to the nozzle and the distance between the counter electrodes is considered, the voltage required for ejection increases as the size of the nozzle becomes smaller. On the other hand, if attention is paid to the local electric field strength, the discharge voltage can be reduced by making the nozzles minute.

吐出 Ejection by electrostatic suction is basically based on charging of liquid (solution) at the nozzle end. It is considered that the charging speed is about a time constant determined by dielectric relaxation.

　溶液の誘電率εを１０Ｆ／ｍ、溶液導電率σを１０^-6Ｓ／ｍを仮定すると、τ＝１．８５４×１０^-6ｓｅｃとなる。あるいは、臨界周波数をｆ_c［Ｈｚ］とすると、

となる。このｆ_cよりも早い周波数の電界の変化に対しては、応答できず吐出は不可能になると考えられる。上記の例について見積もると、周波数としては１０ｋＨｚ程度となる。このとき、ノズル半径２μｍ、電圧５００Ｖ弱の場合、ノズル内流量Ｇは１０^-13ｍ³／ｓと見積もることができるが、上記の例の液体の場合、１０ｋＨｚでの吐出が可能なので、1周期での最小吐出量は１０ｆｌ（フェムトリットル、１ｆｌ＝１０^-16ｌ）程度を達成できる。

Assuming that the solution has a dielectric constant ε of 10 F / m and a solution conductivity σ of 10 ⁻⁶ S / m, τ = 1.854 × 10 ⁻⁶ sec. Alternatively, when the critical frequency and f _c [Hz],

It becomes. For a change in electric field early frequency than the f _c, the discharge can not respond is considered to be impossible. Estimating the above example results in a frequency of about 10 kHz. At this time, when the nozzle radius is 2 μm and the voltage is slightly less than 500 V, the flow rate G in the nozzle can be estimated to be 10 ⁻¹³ m ³ / s. However, in the case of the liquid of the above example, the discharge at 10 kHz is possible, so one cycle Can achieve a minimum discharge amount of about 10 fl (femtoliter, 1 fl = 10 ⁻¹⁶ l).

Note that each of the above embodiments is characterized by the effect of concentrating the electric field at the nozzle tip and the effect of the image force induced on the opposing substrate, as shown in FIG. For this reason, it is not necessary to make the substrate or the substrate support conductive as in the prior art, or to apply a voltage to these substrates or the substrate support. That is, an insulating glass substrate, a plastic substrate such as polyimide, a ceramic substrate, a semiconductor substrate, or the like can be used as the substrate.

In each of the above embodiments, the voltage applied to the electrode may be either positive or negative.

Furthermore, by keeping the distance between the nozzle and the substrate at 500 [μm] or less, discharge of the solution can be facilitated. Although not shown, it is desirable to perform feedback control based on nozzle position detection so as to keep the nozzle constant with respect to the base material.

基材 Also, the substrate may be placed and held in a conductive or insulating substrate holder.

FIG. 24 is a side sectional view of a nozzle portion of an electrostatic suction type liquid ejection device as an example of another basic example to which the present invention is applied. An electrode 15 is provided on the side surface of the nozzle 1, and a controlled voltage is applied between the electrode 15 and the solution 3 in the nozzle. The purpose of this electrode 15 is to control the electronetting effect. If a sufficient electric field is applied to the insulator constituting the nozzle, the Electrotting effect is expected to occur without this electrode. However, in this basic example, the role of the ejection control is also achieved by more positively controlling using this electrode. When the nozzle 1 is made of an insulator, the nozzle tube at the tip is 1 μm, the inner diameter of the nozzle is 2 μm, and the applied voltage is 300 V, the effect is about 30 atm. Although this pressure is insufficient for discharge, it is significant from the viewpoint of supplying the solution to the nozzle tip, and it is considered that discharge can be controlled by this control electrode.

FIG. 9 described above shows the nozzle diameter dependence of the discharge start voltage in the embodiment to which the present invention is applied. As the nozzle of the electrostatic suction type liquid discharge device, the nozzle shown in the liquid discharge head 100 shown in FIG. 11 was used. It has been clarified that the discharge start voltage decreases as the size of the nozzle becomes smaller, and that the discharge can be performed at a lower voltage than before.

In each of the above embodiments, the solution discharge condition is a function of each of the distance (h) between the nozzle substrates, the amplitude (V) of the applied voltage, and the frequency (f) of the applied voltage, and each satisfies certain conditions. Is required as a discharge condition. Conversely, if any one of the conditions is not satisfied, it is necessary to change other parameters.

This situation will be described with reference to FIG.

{Circle around (1)} There is a certain critical electric field Ec that does not discharge unless a higher electric field is applied. The critical electric field varies depending on the diameter of the nozzle, the surface tension of the solution, the viscosity, and the like, and it is difficult to discharge the liquid at Ec or less. At or above the critical electric field Ec, that is, at the dischargeable electric field strength, there is a roughly proportional relationship between the distance between the nozzle substrate (h) and the amplitude of the applied voltage (V), and when the distance between the nozzle and the base material is reduced, the critical The applied voltage V can be reduced.

Conversely, when the distance h between the nozzle and the substrate is extremely large and the applied voltage V is increased, even if the same electric field intensity is maintained, the burst or the burst of the fluid droplet occurs due to the action of corona discharge or the like. I will.

FIG. 1A shows the electric field intensity distribution when the nozzle diameter is φ0.2 [μm], and FIG. 1A shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. 1 (b) shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 2A shows the electric field intensity distribution when the nozzle diameter is φ0.4 [μm], and FIG. 2A shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. FIG. 2B shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 3A shows the electric field intensity distribution when the nozzle diameter is φ1 [μm], and FIG. 3A shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 4A shows the electric field intensity distribution when the nozzle diameter is φ8 [μm], and FIG. 4A shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 5A shows the electric field intensity distribution when the nozzle diameter is φ20 [μm], and FIG. 5A shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 6A shows the electric field intensity distribution when the nozzle diameter is φ50 [μm], and FIG. 6A shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. 7 is a table showing the maximum electric field intensity under each condition of FIGS. FIG. 4 is a diagram illustrating a relationship between a nozzle diameter of a nozzle and a maximum electric field intensity when a liquid level is present at a tip position of the nozzle. It shows the relationship between the nozzle diameter of the nozzle, the discharge start voltage at which the droplet discharged at the nozzle tip starts to fly, the voltage value at the Rayleigh limit of the initial discharge droplet, and the ratio of the discharge start voltage to the Rayleigh limit voltage value. FIG. 4 is a graph showing a relationship between a nozzle diameter and a region of a strong electric field at a nozzle tip. FIG. 1 is a perspective view showing a liquid ejection head as an embodiment of the present invention, partially cut away. FIG. 12 is a cross-sectional view illustrating a liquid chamber structure provided in the liquid ejection head illustrated in FIG. 11 when viewed from a bottom surface direction. FIG. 12 is a bottom view showing a nozzle plate provided in the liquid ejection head shown in FIG. 11. FIG. 14 is a cross-sectional view cut along a cutting line AA ′ shown in FIG. 13. 15A is a partially cutaway perspective view showing an example of another shape of the flow path in the nozzle, FIG. 15A is an example in which a roundness is provided on the solution chamber side, and FIG. Is an example in which is a tapered peripheral surface, and FIG. 15C shows an example in which a tapered peripheral surface and a linear flow path are combined. 4 is a drawing showing steps of a method for manufacturing the liquid ejection head. FIG. 17A is a plan view illustrating a process of the method of manufacturing the liquid discharge head, FIG. 17A is a plan view, and FIG. 17B is a cross-sectional view taken along a cutting line BB ′. 4 is a drawing showing steps of a method for manufacturing the liquid ejection head. 4 is a drawing showing steps of a method for manufacturing the liquid ejection head. 4 is a drawing showing steps of a method for manufacturing the liquid ejection head. 4 is a drawing showing steps of a method for manufacturing the liquid ejection head. It is explanatory drawing which shows the relationship between the discharge operation | movement of a solution, and the voltage applied to a solution, FIG.22 (A) shows the state which does not perform discharge, and FIG.22 (B) shows the discharge state. As an embodiment of the present invention, this is shown for explaining the calculation of the electric field strength of the nozzle. FIG. 1 is a side sectional view of a liquid ejection mechanism as an example of the present invention. FIG. 5 is a diagram illustrating a discharge condition based on a distance-voltage relationship in the liquid discharge device according to the embodiment of the present invention.

Explanation of reference numerals

Reference Signs List 100 liquid ejection head 102 liquid chamber structure 101 solution supply channel 104 nozzle plate 103 nozzle 106 first liquid chamber partition (piezoelectric element, convex meniscus forming means)
107 second liquid chamber partition (piezoelectric element, convex meniscus forming means)
121 Control electrode 141 Substrate 142 Discharge electrode 143 Nozzle layer 143 'Resist layer (photosensitive resin layer)
145 Nozzle flow path 25 Discharge voltage applying means

Claims (21)

In a manufacturing method for manufacturing an electrostatic suction type liquid discharge head having a plurality of nozzles for discharging a solution as droplets from a nozzle tip,
A plurality of ejection electrodes for applying an ejection voltage are formed on a substrate, a photosensitive resin layer is formed on the substrate so as to cover the entire plurality of ejection electrodes, and the photosensitive resin layer is exposed and exposed. By developing, the photosensitive resin layer is erected on the substrate in correspondence with each of the discharge electrodes, and the nozzle diameter is formed into a nozzle shape of 30 μm or less. A flow path in the nozzle is formed so as to communicate from the tip of the nozzle to the discharge electrode, and is joined to a solution supply channel corresponding to the plurality of nozzles. 2. The electrostatic suction according to claim 1, wherein at least the inner surface of each of the solution supply channels is made insulative, and a control electrode for controlling a meniscus position of a solution at a nozzle tip is provided in the solution supply channel. 3. Manufacturing method of a liquid discharge head. 3. The method according to claim 2, wherein the solution supply channel is formed of a piezoelectric material. The method of manufacturing an electrostatic suction type liquid ejection head according to any one of claims 1 to 3, wherein the nozzle diameter of the nozzle is less than 20 µm. The method according to claim 4, wherein the nozzle diameter of the nozzle is 10 µm or less. 6. The method for manufacturing an electrostatic suction type liquid ejection head according to claim 5, wherein the nozzle diameter of the nozzle is 8 μm or less. 7. The method according to claim 6, wherein the nozzle diameter of the nozzle is 4 μm or less. The method of manufacturing an electrostatic suction type liquid discharge head according to any one of claims 1 to 7, wherein the photosensitive resin layer contains fluorine. A driving method for driving an electrostatic attraction type liquid ejection head manufactured by the method of manufacturing an electrostatic attraction type liquid ejection head according to claim 1.
An electrostatic suction type wherein the tip of each of the nozzles is opposed to a base material, a chargeable solution is supplied to each of the solution supply channels, and a discharge voltage is individually applied to the plurality of discharge electrodes. A method for driving the liquid ejection head. 10. The method of driving an electrostatic suction type liquid discharge head according to claim 9, wherein the solution in each of the nozzle internal flow paths forms a convex shape from the tip of the nozzle. The electrostatic suction type according to claim 10, wherein a discharge voltage is applied to the discharge electrode when the solution in each of the flow paths in the nozzle forms a convex shape from the tip of the nozzle. A method for driving the liquid ejection head. An electrostatic suction type liquid ejection head manufactured by the method for manufacturing an electrostatic suction type liquid ejection head according to any one of claims 1 to 8, wherein a tip of each nozzle faces a substrate. An electrostatic suction type liquid ejection device that can be arranged as
Solution supply means for supplying a chargeable solution to each of the nozzle channels,
And a discharge voltage applying means for applying a discharge voltage to each of the plurality of discharge electrodes. 13. The electrostatic suction type liquid according to claim 12, further comprising a convex meniscus forming means for forming a state in which the solution in each of the nozzle internal flow paths protrudes from the tip of the nozzle. Discharge device. The ejection voltage applying means applies an ejection voltage to the ejection electrode when the convex meniscus forming means forms a state in which the solution in each of the flow paths in the nozzle protrudes from the tip of the nozzle. The electrostatic suction type liquid ejection device according to claim 13, wherein: The convex meniscus forming means has a piezoelectric element provided corresponding to each of the nozzles, and each of the piezoelectric elements changes the pressure of the solution in the flow path in the nozzle by deformation. An electrostatic suction type liquid ejection device according to claim 13. In a manufacturing method for manufacturing a nozzle plate having a plurality of nozzles for discharging a solution as droplets from a nozzle tip,
A plurality of ejection electrodes for applying an ejection voltage are formed on a substrate, a photosensitive resin layer is formed on the substrate so as to cover the entire plurality of ejection electrodes, and the photosensitive resin layer is exposed and exposed. By developing, the photosensitive resin layer is erected on the substrate in correspondence with each of the discharge electrodes, and the nozzle diameter is formed into a nozzle shape of 30 μm or less. Forming a flow path in the nozzle so as to communicate from the tip of the nozzle to the discharge electrode. The method according to claim 16, wherein the nozzle diameter of the nozzle is less than 20m. 18. The method according to claim 17, wherein the nozzle diameter of the nozzle is 10 μm or less. 19. The method for manufacturing a nozzle plate according to claim 18, wherein the nozzle diameter of the nozzle is 8 μm or less. 20. The method according to claim 19, wherein the nozzle diameter of the nozzle is 4 μm or less. The method according to any one of claims 16 to 20, wherein the photosensitive resin layer contains fluorine.

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