JP4218949B2 - Electrostatic suction type liquid discharge head manufacturing method, nozzle plate manufacturing method, electrostatic suction type liquid discharge head driving method, and electrostatic suction type liquid discharge device - Google Patents

Description

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

As a conventional ink jet recording method, a piezo method that ejects ink droplets by deforming an ink flow path by vibration of a piezoelectric element, a heating element is provided in the ink flow path, and the heating element generates heat to generate bubbles. And a thermal method that discharges ink droplets in response to pressure changes in the ink flow path caused by bubbles, and an electrostatic suction method that charges ink in the ink flow channels and discharges ink droplets by the electrostatic suction force of the ink It has been known.
Japanese Patent Laid-Open No. 11-277747 (FIGS. 2 and 3)

However, the conventional example has the following problems.
(1) Limit and stability of microdroplet formation Since the nozzle diameter is large, the shape of the droplet ejected from the nozzle is not stable, and there is a limit to micronization of the droplet.
(2) High applied voltage For the discharge of minute droplets, miniaturization of the nozzle outlet is an important factor, but in the principle of the conventional electrostatic suction method, the nozzle diameter is large. As a result, the electric field strength at the nozzle tip is weak and it was necessary to apply a high discharge voltage (for example, a very high voltage close to 2000 [V]) in order to obtain the electric field strength necessary for discharging the droplet. . Therefore, in order to apply a high voltage, voltage drive control becomes expensive, and there is also a problem in terms of safety.

  Accordingly, a first object is to provide a liquid ejecting apparatus capable of ejecting micro droplets. At the same time, a second object is to provide a liquid ejecting apparatus capable of ejecting stable droplets. Furthermore, a third object is to provide a liquid ejecting apparatus that can eject minute droplets and has high landing accuracy. Furthermore, a fourth object is to provide an inexpensive and highly safe liquid ejection device that can reduce the applied voltage.

In order to solve the above problems, in a manufacturing method for manufacturing an electrostatic suction type liquid discharge head having a plurality of nozzles for discharging a solution as charged droplets from a nozzle tip as in the invention of claim 1 A plurality of discharge electrodes for applying a discharge voltage are formed on the substrate, a photosensitive resin layer is formed on the substrate so as to cover the entire plurality of discharge electrodes, and the photosensitive resin layer is exposed. A nozzle having a protruding shape in which the photosensitive resin layer is erected with respect to the substrate by developing so as to correspond to each of the discharge electrodes, and the inner diameter of the tip of the nozzle is larger than 0.2 μm and 4 μm In addition to forming the following, a flow path in the nozzle is formed in each of the nozzles so as to pass from the tip of the nozzle to the discharge electrode, and solution supply corresponding to the plurality of nozzles Provided is a method of manufacturing an electrostatic attraction type liquid discharge head characterized by joining to a channel.

  Hereinafter, the term “nozzle diameter” refers to the internal diameter (the internal diameter of the nozzle tip) at which the droplet is discharged. The cross-sectional shape of the liquid discharge hole in the nozzle is not limited to a circle. For example, when the cross-sectional shape of the liquid discharge hole is a polygon, star, or other shape, the circumscribed circle of the cross-sectional shape is 30 [μm] or less. Hereinafter, in the case of the nozzle diameter or the internal diameter of the tip of the nozzle, the same applies when other numerical values are limited. In addition, the term “nozzle radius” indicates a length that is ½ of this nozzle diameter (inner diameter at the tip of the nozzle).

According to a second aspect of the present invention, in the method of manufacturing the electrostatic attraction type liquid discharge head according to the first aspect, when forming the plurality of nozzles, the shape of each nozzle is increased toward the tip. Provided is a method for manufacturing an electrostatic attraction type liquid discharge head characterized in that it has a truncated cone shape with a reduced diameter .

According to a third aspect of the present invention, in the method of manufacturing the electrostatic attraction type liquid discharge head according to the first or second aspect, a through-hole communicating with the substrate is formed when the plurality of discharge electrodes are formed. Is formed on each discharge electrode. A method of manufacturing an electrostatic attraction type liquid discharge head is provided.

According to a fourth aspect of the present invention, in the method of manufacturing the electrostatic suction type liquid discharge head according to the third aspect, a positive type is used as the photosensitive resin layer, and the photosensitive resin layer Provided is a method for manufacturing an electrostatic suction type liquid discharge head, wherein a portion overlapping each through hole is exposed to a deep layer during exposure and a portion between the plurality of nozzles is exposed to a middle layer.

According to a fifth aspect of the present invention, in the method of manufacturing an electrostatic suction type liquid discharge head according to any one of the first to third aspects, at least the inner surface of each of the solution supply channels is insulative. And providing a control electrode for controlling the meniscus position of the solution at the tip of the nozzle in the solution supply channel.

According to a sixth aspect of the present invention, in the method of manufacturing the electrostatic suction type liquid discharge head according to the fifth aspect, the solution supply channel is formed of a piezoelectric material. A method for manufacturing a suction-type liquid discharge head is provided.

According to a seventh aspect of the present invention, in the manufacturing method of the electrostatic attraction type liquid discharge head according to any one of the first to sixth aspects, the photosensitive resin layer contains fluorine. Provided is a method for manufacturing an electrostatic attraction type liquid discharge head.

A drive for driving the electrostatic suction type liquid discharge head manufactured by the manufacturing method of the electrostatic suction type liquid discharge head according to any one of claims 1 to 7 as in the invention of claim 8. In the method, the tip of each nozzle is opposed to a substrate, a chargeable solution is supplied to each solution supply channel, and a discharge voltage is applied to each of the plurality of discharge electrodes. Provided is a method for driving an electrosuction liquid discharge head.

  The “base material” refers to an object that receives the landing of the droplets of the discharged solution, and is not particularly limited in terms of material. 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 power base should correspond to the substrate.

According to a ninth aspect of the present invention, in the driving method of the electrostatic attraction type liquid discharge head according to the eighth aspect , the solution in the flow path in each nozzle protrudes from the tip of the nozzle. Provided is a driving method of an electrostatic suction type liquid discharge head, characterized by forming a raised state.

According to a tenth aspect of the present invention, in the driving method of the electrostatic attraction type liquid discharge head according to the ninth aspect , the solution in the flow path in each nozzle protrudes from the tip portion of the nozzle. There is provided a driving method of an electrostatic suction type liquid discharge head, wherein a discharge voltage is applied to the discharge electrode when a raised state is formed.

As in the invention described in claim 11 , the electrostatic suction type liquid discharge head manufactured by the method of manufacturing an electrostatic suction type liquid discharge head described in any one of claims 1 to 7 , An electrostatic suction type liquid discharge device in which a tip portion of the nozzle can be disposed to face a substrate, a solution supply means for supplying a chargeable solution to each of the flow paths in the nozzle, and the plurality of the plurality of nozzles There is provided an electrostatic suction type liquid ejecting apparatus, further comprising ejection voltage applying means for applying an ejection voltage to each ejection electrode.

As in the invention according to claim 12 , in the electrostatic suction type liquid ejection device according to claim 11 , the solution in the flow path in each nozzle rises in a convex shape from the tip of the nozzle An electrostatic suction type liquid discharge device is further provided, which further includes a convex meniscus forming means for forming the above.

According to a thirteenth aspect of the present invention, in the electrostatic suction type liquid discharge device according to the twelfth aspect , the discharge voltage applying means includes the convex meniscus forming means of each of the flow paths in the nozzle. There is provided an electrostatic suction type liquid discharge apparatus, wherein a discharge voltage is applied to the discharge electrode when a solution is formed in a convex shape from the tip of the nozzle.

According to a fourteenth aspect of the present invention, in the electrostatic attraction type liquid ejection device according to the twelfth or thirteenth aspect , the convex meniscus forming means is a piezoelectric element provided corresponding to each of the nozzles. There is provided an electrostatic suction type liquid ejecting apparatus including an element, and each piezoelectric element changes a pressure of a solution in a flow path in the nozzle by deformation.

A manufacturing method for manufacturing a nozzle plate having a plurality of nozzles for discharging a solution as charged droplets from a nozzle tip as in the invention according to claim 15 , wherein a plurality of discharge electrodes for applying a discharge voltage are formed on a substrate A photosensitive resin layer is formed on the substrate so as to cover the whole of the plurality of discharge electrodes, and the photosensitive resin layer is exposed and developed to correspond to each of the discharge electrodes. The photosensitive resin layer is formed into a protruding nozzle that stands up with respect to the substrate, and the inner diameter of the tip of the nozzle is greater than 0.2 μm and less than or equal to 4 μm . A nozzle plate manufacturing method is characterized in that an in-nozzle flow path is formed so as to lead from the tip of the nozzle to the discharge electrode.

A method of manufacturing a nozzle plate according to claim 15 , as in the invention described in claim 16 , wherein when forming the plurality of nozzles, the outer diameter of each of the nozzles decreases toward the tip. Provided is a method of manufacturing a nozzle plate characterized by being trapezoidal.

According to a seventeenth aspect of the present invention, in the method for manufacturing a nozzle plate according to the fifteenth or sixteenth aspect , when the plurality of discharge electrodes are formed, through holes extending to the substrate are formed in the discharge electrodes. A method for manufacturing a nozzle plate is provided.

  The method of manufacturing a nozzle plate according to claim 17, wherein a positive type is used as the photosensitive resin layer, and each of the through holes is exposed during exposure of the photosensitive resin layer. Provided is a method for producing a nozzle plate, wherein a portion overlapping a hole is exposed to a deep layer and a portion between the plurality of nozzles is exposed to a middle layer.

The nozzle plate manufacturing method according to any one of claims 15 to 18 , as in the invention described in claim 19 , wherein the photosensitive resin layer contains fluorine. A manufacturing method is provided.

The present invention is characterized in that the electric field strength is increased by concentrating the electric field at the tip of the nozzle by making the nozzle an ultra-fine diameter that is not conventional. The diameter reduction of the nozzle will be described in detail later. In such a case, it is possible to discharge liquid droplets without a counter electrode facing the tip of the nozzle. Then, the droplets fly by the electrostatic force induced at the nozzle tip .

  However, although the configuration of the present invention can eliminate the need for the counter electrode, the counter electrode may be used in combination. When using the counter electrode together, it is desirable to arrange the base material in a state along the counter surface of the counter electrode and to arrange the counter surface of the counter electrode perpendicular to the direction of droplet discharge from the nozzle, It is possible to use electrostatic force due to the electric field between the nozzle and the counter electrode for induction of the flying electrode, and if the counter electrode is grounded, the charge of the charged droplet can be released through the counter electrode. In addition, since the effect of reducing the accumulation of electric charge can be obtained, it can be said that the combined use is desirable.

  In addition, since the nozzle is formed simply by exposing and developing the photosensitive resin layer as in the inventions according to claims 1 and 16, flexibility in the nozzle shape 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 5 , the control electrode for controlling the meniscus position is provided in the solution supply channel, and the volume of the solution supply channel is changed by applying a voltage to the control electrode, so that the nozzle tip portion It controls the meniscus position of the solution.

Further, in the invention according to claim 5 , the reason why the inner surface of the solution supply channel is insulative is to prevent a stroke through the solution existing between the discharge electrode and the control electrode. The control electrode provided on the substrate may be covered with an insulating layer. The level of the insulating layer needs to determine the material and film thickness in consideration of the conductivity of the solution and the applied voltage. For example, vapor deposition of parylene resin, CVD of SiO ₂ or Si ₃ N ₄ is suitable.

  In addition, as in the inventions according to claims 10 and 13, since the solution in the flow path in the nozzle rises in a convex shape from the tip portion at the tip portion of each nozzle, the electric field is concentrated in the convex portion of the solution. In addition, the electric field strength is greatly increased. Therefore, even when the voltage applied to the electrode is low, the droplet is ejected from the tip portion against the surface tension of the solution, and the droplet is ejected.

The electric field strength distribution is narrowed by setting the internal diameter of the nozzle to less than 20 [μm]. As a result, the electric field can be concentrated. As a result, the formed droplets can be made minute and the shape can be stabilized, and the total applied voltage can be reduced. In addition, immediately after the droplet is ejected 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 rapidly decreases, and thereafter, the droplet is decelerated due to air resistance. However, droplets that are minute droplets and in which an electric field is concentrated are accelerated by electrostatic force as they approach the substrate or the counter electrode. By balancing the deceleration by the air resistance and the acceleration by the electrostatic force , it is possible to stably fly the fine droplets and improve the landing accuracy.

By the internal diameter of Bruno nozzle to 10 [[mu] m] or less, it becomes more possible to concentrate an electric field, and the minute of additional droplet, the variation of the distance of the counter electrode during flight can affect the electric field strength distribution Therefore, 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 accuracy.

The internal diameter of Roh nozzle by a 8 [[mu] m] or less, it becomes possible to further concentrate the electric field, and the minute of additional droplets to change the electric field intensity distribution of the distance of the counter electrode and substrate during flight Since the influence can be reduced, it is possible to reduce the influence of 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 accuracy.

When the internal diameter of the nozzle is set to 4 [μm] or less as in the inventions according to claims 1 and 15 , a remarkable electric field concentration can be achieved, the maximum electric field strength can be increased, It is possible to make stable ultrafine droplets and increase the initial discharge speed of the droplets. Thereby, by improving the flight stability, it is possible to further improve the landing accuracy and improve the ejection response.

As in the first and fifteenth aspects of the present invention, the inner diameter of the nozzle is preferably 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 discharge 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 electrical insulating material, and an electrode for applying a discharge voltage is inserted into the nozzle or plating that functions as the electrode is formed. It is preferable.
(2) In the configuration of each of the above claims or the configuration of (1), the nozzle (that is, the photosensitive resin layer) is formed of an electrical insulating material, and an electrode is inserted into the nozzle or plating as the electrode is formed. It is preferable to provide an electrode for discharge also outside the nozzle.

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

According to (1) and (2), in addition to the operational effects of the above claims, the ejection force can be improved, so that even when the nozzle diameter is further reduced, the liquid droplets can be ejected at a low voltage.
(3) In the configuration of each of the above claims and the configuration of (1) or (2), the base material is preferably formed of a conductive material or an insulating material.
(4) In the configuration of each of the above claims and the configuration of (1), (2), or (3), the discharge voltage V applied to the discharge electrode preferably satisfies the range of the following formula (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。

Where γ: surface tension of the solution [N / m], ε ₀ : vacuum dielectric constant [F / m], d: nozzle diameter [m], h: distance between nozzle and substrate [m], k: nozzle A proportional constant depending on the shape (1.5 <k <8.5) is used.
(5) In the configurations of the above claims and the configurations of (1), (2), (3) or (4), it is preferable that the applied discharge voltage is 1000 [V] or less.

By setting the upper limit value of the discharge voltage in this way, discharge control can be facilitated, and the reliability of the apparatus can be easily improved by improving the durability of the apparatus and executing safety measures.
(6) In the configurations of the above claims and the configurations of (1), (2), (3), (4), or (5), it is preferable that the discharge voltage to be applied 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 make discharge control easier and to further improve the reliability by further improving the durability of the apparatus and executing safety measures.
(7) In the configuration of each of the above claims and the configuration of any of (1) to (6) above, the distance between the nozzle and the substrate may be 500 [μm] or less, even when the nozzle diameter is small. It is preferable because high landing accuracy can be obtained.
(8) In the configuration of each of the above claims and the configuration of any one of (1) to (7), it is preferable that the pressure is applied to the solution in the nozzle.
(9) In the configuration of each of the above claims and the configuration of any of the above (1) to (8), when discharging by a single pulse,

It is also possible to apply a pulse width Δt greater than or equal to the time constant τ determined by. Where ε is the dielectric constant [F / m] of the solution, and σ is the electrical conductivity of the solution [S / m].

  In the present invention, the nozzle is formed only by exposing and developing the photosensitive resin layer, which is advantageous in terms of flexibility in nozzle shape, compatibility with a line head having a large number of nozzles, and manufacturing cost.

  In addition, since a plurality of nozzle shapes are formed and each flow path in the nozzle is guided to the electrode, a discharge voltage can be applied to the solution supplied to each flow path in the nozzle through the electrode. By applying a discharge voltage to the electrodes, droplets are discharged from the tip of the nozzle shape, and a pattern in which the droplets that have landed on the substrate become dots is formed on the substrate. Since a plurality of such nozzle shapes are formed on the substrate, the pattern can be formed quickly.

In such a case, it is possible to discharge liquid droplets without a counter electrode facing the tip of the nozzle. Then, the droplets fly by the electrostatic force induced at the nozzle tip .

  Furthermore, in the present invention, since the solution in the nozzle flow path is raised from the tip at the tip of each nozzle shape, even if the voltage applied to the electrode is low, the convex portion of the solution In FIG. 2, the electric field is concentrated and the electric field strength is very high. Therefore, even if the voltage applied to the electrode is low, the liquid droplet is ejected from the tip of the nozzle shape.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, 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 even more preferably 10 [μm]. ], More preferably 8 [μm] or less, still more preferably 4 [μm] or less. The nozzle diameter is preferably larger than 0.2 [μm]. Hereinafter, the relationship between the nozzle diameter and the electric field strength will be described below with reference to FIGS. Corresponding to FIGS. 1 to 6, the electric field strength when the nozzle diameter is φ0.2, 0.4, 1, 8, 20 [μm] and the nozzle diameter φ50 [μm] conventionally used as a reference. Show the distribution.

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

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

  1 to 6, it was found that the electric field intensity distribution spreads over a wide area when the nozzle diameter is φ20 [μm] (FIG. 5) or more. In addition, it was found from the chart in FIG. 7 that the distance between the nozzle and the counter electrode affects the electric field strength.

  For these reasons, when the nozzle diameter is equal to or smaller than φ8 [μm] (FIG. 4), the electric field strength is concentrated and the variation in the distance of the counter electrode hardly affects the electric field strength 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 material characteristics of the base material, and the thickness.

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

  From the graph shown in FIG. 8, it was found that when the nozzle diameter becomes φ4 [μm] or less, the electric field concentration becomes extremely large and the maximum electric field strength can be increased. As a result, the initial discharge speed of the solution can be increased, so that the droplet flying stability is increased and the charge transfer speed at the nozzle tip is increased, thereby improving the discharge response.

  Next, the maximum charge amount that can be charged in the discharged droplets will be described below. The amount of charge that can be charged in 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 charge amount [C] that gives the Rayleigh limit, ε ₀ is the dielectric constant [F / m] of vacuum, γ is the surface tension [N / m] of the solution, and d ₀ is the diameter of the droplet [m]. It is.

  The closer the charge amount q obtained by the above equation (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. Dispersion of the solution occurs at the discharge holes, resulting in lack of discharge stability.

  Here, the nozzle diameter of the nozzle, the discharge start voltage at which the droplet discharged from 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, when the nozzle diameter is in the range of φ0.2 [μm] to φ4 [μm], the ratio of the ejection start voltage to the Rayleigh limit voltage value exceeds 0.6, and the charging efficiency of the droplets is good. Thus, it was found that stable discharge can be performed in this range.

For example, in the graph represented by 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 shown in FIG. 10, when the nozzle diameter becomes φ0.2 [μm] or less. It is shown that the region of electric field concentration becomes extremely narrow. This indicates that the ejected droplets cannot receive sufficient energy for acceleration and the flight stability is lowered. Therefore, the nozzle diameter is preferably set larger than φ0.2 [μm].

  As shown in FIG. 11, the electrostatic attraction type droplet discharge device of this embodiment is a static chamber provided with liquid chamber partition walls 106, 106,... And liquid chamber partition walls 107, 107,. An electrosuction liquid discharge head 100, a supply pump (not shown) for applying a solution supply pressure 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) shown in FIG.

  First, the liquid discharge head 100 will be described with reference to FIG. Here, FIG. 11 is a perspective view showing the liquid discharge head 100 with the bottom surface thereof being the front side of the paper and partially broken the liquid discharge head 100. As shown in FIG. 11, the liquid discharge head 100 includes a liquid chamber structure 102 in which a plurality of solution supply channels 101 serving as liquid chambers are formed, and a chargeable solution attached to the bottom of the liquid chamber structure 102. And a nozzle plate 104 provided with ultrafine nozzles 103 ejected as droplets from the tip thereof corresponding to the respective solution supply channels 101.

  The liquid chamber structure 102 will be described. FIG. 12 is a cross-sectional view mainly showing one solution supply channel 101 when the liquid chamber structure 102 is viewed from the bottom surface direction. As shown in FIGS. 11 and 12, the liquid chamber structure 102 includes 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 wall 107 is stacked on each first liquid chamber partition wall 106, and the second liquid chamber partition wall 107 is bonded and fixed to the first liquid chamber partition wall 106 through an adhesive layer 108. Thereby, on the liquid chamber side wall 105, a plurality of grooves are formed by arranging a plurality of protrusions made up of a pair of the first liquid chamber partition wall 106 and the second liquid chamber partition wall 108 in parallel with each other. The cover plate 110 is bonded and fixed on the second liquid chamber side walls 107, 107,... Via the 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 wall 105, and the cover plate 110 are formed. At the bottom surface of the liquid chamber structure 102, the bottom of each solution supply channel 101 is open, and each solution supply channel 101 is closed by adhering and fixing a nozzle plate 104 described later to the bottom surface of the liquid chamber structure 102. A nozzle 103 is formed in the nozzle plate 104 corresponding to each solution supply channel 101.

  Each solution supply channel 101 is shallow in the vicinity of the upper end surface 111 of the liquid chamber side wall 105, and a shallow groove 118 is formed in the vicinity of the upper end surface 111. A liquid inlet 119 and a manifold 120 connected to the liquid inlet 119 are formed in the upper part of the cover plate 110. Then, each solution supply channel 101 is covered with the cover plate 110, whereby the upper end portion of each solution supply channel 101 is connected to the liquid supply source that stores the solution via the manifold 120 and the liquid inlet 119. The liquid discharge head 100 is provided with a supply pump (solution supply means) (not shown) that applies a supply pressure of the solution to each solution supply channel 101, and each pressure is supplied from the liquid supply source by the pressure applied by the supply pump. A solution is supplied to the solution supply channel 101. This supply pump supplies the solution while maintaining the supply pressure in 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 occurs through the solution existing between the discharge electrode 142 of the nozzle plate 104 and the control electrode 121 described later. It is for preventing. The material and film thickness of the insulating layer 125 must be determined in consideration of the conductivity of the solution and the applied voltage. As the insulating layer 125, a film formed by depositing parylene resin by a vapor deposition method, or a film formed by depositing SiO ₂ or Si ₃ N ₄ by a CVD method is suitable.

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

  The liquid chamber partition walls 106 and 107 are piezoelectric ceramic plates, which are made of a piezoelectric zirconate titanate (PZT) piezoelectric ceramic material having ferroelectricity, and are polarized in a direction opposite to each other in the stacking direction. The liquid chamber partition walls 106 and 107 are deformed by applying a voltage to the control electrode 121, and pressure is applied to the solution in the solution supply channel 101. However, the pressure of the liquid droplet partition walls 106 and 107 alone will be described later. The liquid droplets are not ejected from the tip portion of the nozzle 103, and only a convex meniscus protruding from the tip portion of the nozzle 103 is formed. In other words, the liquid chamber partition walls 106, 106,... And the liquid chamber partition walls 107, 107,... Are convex meniscus forming means for forming a state in which the solution in each nozzle flow path 145 is raised from the tip. 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 taken along the cutting line AA ′. The nozzle plate 104 includes a base 141, an electrically insulating substrate 141, a plurality of discharge electrodes 142, 142,... Formed on the surface 141a of the substrate 141, and a plurality of discharge electrodes 142, 142,. A nozzle layer 143 laminated on the entire surface 141a.

  The back surface 142b of the substrate 141 is fixed to the bottom surface of the liquid chamber structure 102 with an adhesive or the like. Further, a plurality of through holes 141c, 141c,... Are formed in the substrate 141, and these through holes 141c, 141c,... Are arranged so as to correspond to the solution supply channels 101, respectively. 101 communicates. That is, the through hole 141 c constitutes the lower part of the solution supply channel 101.

  The discharge electrodes 142, 142,... Are formed so as 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 close the corresponding through hole 141c, and each discharge electrode 142 overlaps the corresponding through hole 141c when viewed from the bottom. That is, each ejection electrode 142 faces the corresponding solution supply channel 101 and constitutes the bottom surface of the corresponding solution supply channel 101. A through hole 142 a is formed in the discharge electrode 142 at a portion overlapping the through hole 141 c, and the through hole 142 a communicates with the corresponding solution supply channel 101. Each discharge electrode 142 is connected to a wiring 144 that is integrally formed, and each wiring 144 is 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 on the nozzle layer 143, and the plurality of nozzles 103, 103,. Each nozzle 103 is formed so as to stand substantially perpendicular to the substrate 141 (so as to hang down). These nozzles 103, 103,... Are arranged so as to correspond to the solution supply channels 101, respectively, and each nozzle 103 overlaps the corresponding through hole 141c when viewed from the bottom. Each nozzle 103 is formed with an in-nozzle channel 145 penetrating from the tip of the nozzle 103 along the center line thereof, and a nozzle hole 103 a serving as a terminal of the in-nozzle channel 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 142 a 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 141c and the nozzle flow path 145, and is in direct contact with the discharge electrode 142 in each solution supply channel 101 and each nozzle flow path 145. In the drawing, the plurality of nozzles 103, 103,... Are arranged in a line, but they may be arranged in two or more lines, or may be arranged 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. In addition, 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. ,... May be formed with a water-repellent film having water repellency (for example, a metal film is formed on the surface of the nozzles 103, 103,..., And the metal and the water-repellent resin are formed on the metal film. A water-repellent layer is formed by eutectoid plating.) Here, the water repellency is a property of repelling the solution discharged from the nozzle 103. Further, the water repellency of the nozzle layer 143 can be controlled by selecting a water repellent treatment method according to the solution. Water repellent treatment methods include electrodeposition of cationic or anionic fluorine-containing resins, fluorine polymer, silicone resin, polydimethylsiloxane coating, sintering method, eutectoid plating method of fluorine polymers, amorphous Deposition method of alloy thin film, Method of attaching a film such as organic silicon compound mainly composed of polydimethylsiloxane and fluorine-containing silicon compound formed by plasma polymerization of hexamethyldisiloxane as monomer by plasma CVD method There is.

  Each nozzle 103 will be described in further detail. The nozzle 103 has a uniform opening diameter at the tip and a 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 tip so that the diameter becomes narrower toward the tip, and is formed in a truncated cone shape that is almost as close to a cone as possible. As an example of specific dimensions of each part, the internal diameter of the in-nozzle channel 145 is 30 [μm] or less, further less than 20 [μm], further 10 [μm] or less, further 8 [μm] or less, 4 [μm] or less is preferable, and in this embodiment, the internal diameter of the flow path 145 in the nozzle is set to 1 [μm]. The external diameter at the tip of the nozzle 103 is set to 2 [μm], the diameter of the base of the nozzle 103 is set to 5 [μm], and the height of the nozzle 103 is set to 100 [μm].

  The dimensions of the nozzle 103 are not limited to the above example. In particular, the nozzle inner diameter is a range in which the discharge voltage that enables the discharge of droplets by the effect of electric field concentration described later is less than 1000 [V], for example, the nozzle diameter is 70 [μm] or less. Desirably, the diameter is 20 [μm] or less, and the diameter within which it is feasible to form a through-hole through which a solution is passed by the current nozzle forming technique is set as the lower limit. Further, it is desirable that the nozzles 103, 103,... Have the same shape, but they may have different shapes.

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

  Next, a circuit configuration for driving the liquid discharge head 100 will be described. The circuit for driving the liquid discharge head 100 includes discharge voltage application means 25 (shown in FIG. 13 for convenience) for individually applying discharge voltages to the discharge electrodes 142, 142,..., And the nozzles 103, 103,. And a counter electrode 23 (shown in FIG. 14) for supporting the substrate 200 that receives the landing of droplets on the counter surface 23a.

  The discharge voltage applying means 25 includes: a bias power source 30 that applies a DC bias voltage to the discharge electrode 142; and a discharge power source 29 that applies a pulse voltage that is superimposed on the bias voltage and that is a potential required for discharge to the discharge electrode 142. Corresponding to each discharge electrode 142 is provided. 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 to each of the discharge electrodes 142, 142,.

  The bias voltage by the bias power supply 30 is applied in a constant manner within a range where the solution is not discharged, thereby reducing in advance the voltage range to be applied during discharge, thereby improving the reactivity during discharge. Yes.

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

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。

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

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

  Further, since the counter electrode 23 is grounded, the ground potential is always maintained. Therefore, when a pulse voltage is applied, the liquid droplets ejected by the electrostatic force generated by the electric field generated between the tip of each nozzle 103 and the opposing surface 23a are guided to the opposing electrode 23 side.

  The liquid discharge head 100 discharges liquid droplets by increasing the electric field strength by concentration of the electric field at the nozzles 103, 103,... Although it is possible to discharge droplets without induction by the counter electrode 23, it is desirable that induction by electrostatic force is performed between the nozzles 103, 103,... And the counter electrode 23. In addition, the charge of the charged droplet can be released 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. Examples of the organic liquid include 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, butyl Ethers such as carbitol, butyl carbitol acetate, epichlorohydrin; acetone, methyl ethyl ketone, 2-methyl-4-pentanone, aceto Ketones such as enone; fatty acids such as formic acid, acetic acid, dichloroacetic acid, trichloroacetic acid; methyl formate, ethyl formate, methyl acetate, ethyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-3-methoxybutyl, 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, acetamide, N-methylacetamide, N-methylpropionamide, N, N, N ′, N′-tetramethylurea and N-methylpyrrolidone; dimethylsulfoxide, sulfolane and the like Sulfur compounds; hydrocarbons such as benzene, p-cymene, naphthalene, cyclohexylbenzene, 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. And halogenated hydrocarbons. Further, 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 electrical conductivity (silver powder or the like) is used as a solution and discharging is performed, the target substance to be dissolved or dispersed in the above-described liquid is a nozzle. There is no particular limitation except for coarse particles that cause clogging. Conventionally known phosphors such as PDP, CRT, FED and the like can be used without particular limitation. For example, (Y, Gd) BO ₃ : Eu, YO ₃ : Eu, etc. as red phosphors, and Zn ₂ SiO ₄ : Mn, BaAl ₁₂ O ₁₉ : Mn, (Ba, Sr, Mg) O as green phosphors. _{· α-Al 2 O 3:} Mn , etc., as a blue _{phosphor, BaMgAl 14 O 23: Eu,} BaMgAl 10 O 17: Eu and the like. Various binders are preferably added in order to firmly adhere the target substance to 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 resins such as lauryl methacrylate / 2-hydroxyethyl methacrylate copolymer and metal salts thereof; poly (meth) acrylamide resins such as poly N-isopropylacrylamide and poly N, N-dimethylacrylamide; polystyrene, acrylonitrile Styrene resins such as styrene copolymers, styrene / maleic acid copolymers, styrene / isoprene copolymers; styrene / n-butyl methacrylate Styrene and acrylic resins such as copolymer; Saturated and unsaturated polyester resins; Polyolefin resins such as polypropylene; Halogenated polymers such as polyvinyl chloride and polyvinylidene chloride; Polyvinyl acetate, polyvinyl 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 Resin; Amide resin such as benzoguanamine; Urea resin; Melamine resin; Polyvinyl alcohol resin and its anionic cation modification; Polyvinylpyrrolidone and its copolymer; Polyethylene oxide, carboxyl Alkylene oxide homopolymers, copolymers and cross-linked products 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, carrageenin, glue, albumin, various starches, corn starch, konjac, fungi, agar, soybean protein; terpene resin; ketone resin; Rosin and rosin ester; polyvinyl methyl ether, polyethyleneimine, polystyrene sulfonic acid, polyvinyl sulfonic acid and the like can be used. These resins may be used not only as a homopolymer but also blended within a compatible range.

  When the liquid ejection apparatus of this embodiment is used as a patterning method, it can be typically used for display applications. Specifically, plasma display phosphor formation, plasma display rib formation, plasma display electrode formation, CRT phosphor formation, FED (field emission display) phosphor formation, FED rib Formation, color filters for liquid crystal displays (RGB colored layers, black matrix layers), spacers for liquid crystal displays (patterns corresponding to black matrices, dot patterns, etc.), and the like. Here, the rib generally means a barrier, and when a plasma display is taken as an example, it is used to separate plasma regions of respective colors. Other applications include micro lenses, semiconductor coatings such as magnetic materials, ferroelectrics, conductive paste (wiring, antenna), etc., and graphic applications such as normal printing, special media (films, cloth, steel plates, etc.) ) Printing, curved surface printing, printing plates of various printing plates, application using this embodiment such as adhesives and sealing materials for processing applications, biopharmaceuticals for medical applications (mixing a plurality of trace components) It can be applied to the application of a sample for genetic diagnosis.

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

  In order to manufacture the liquid discharge 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 that constitutes the liquid chamber side wall 105, the first liquid chamber partition wall 106 and the second liquid chamber partition wall 107. Is prepared and formed into a sheet having a predetermined thickness using a doctor blade method, a screen printing method, or the like.

  Then, a piezoelectric laminated body 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 an upper sheet and a lower sheet Are polarized in the thickness direction and in opposite directions.

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

  Thereafter, electrodes are formed on the liquid chamber partition walls 106 and 107 constituting the groove by a known method such as plating. An electrode is not formed on the bottom surface of the groove. Then, when an adhesive to become the adhesive layer 109 is applied to the upper part of the second liquid chamber partition wall 107 and the cover plate 110 is bonded together, a liquid chamber structure 102 in which a plurality of solution supply channels 101 are formed in parallel to each other. Is manufactured. Then, the drive substrate 122 is attached to the liquid chamber side wall 105, and one end portion of the conducting wire 124 is joined to each electrode 11, and the other end portion of the conducting wire 124 is joined to the wiring pattern 123.

  On the other hand, in order to manufacture the nozzle plate 104, a flat substrate 141 is first prepared as shown in FIG. 16 (a plurality of through holes 141c, 141c,... Are not yet formed in the substrate 141 at this time). ), A conductive film 142 ′ is formed on the entire surface 141a of the substrate 141 by a film forming method such as PVD, CVD, plating, etc., and resists 150, 150,... Are formed on the conductive film 142 ′ by photolithography. Form. Here, the shape of the resist 150 in a plan view is a shape in which the discharge 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 processed to form a plurality of discharge electrodes 142, 142,. Then, the resists 150, 150,... Are removed (FIG. 17). As described above, since the plurality of discharge electrodes 142, 142,... Are collectively formed through the film forming process, the mask process, and the shape processing process, the production efficiency of the nozzle plate 104 is good.

  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 discharge electrodes 142, 142,... And the wirings 144, 144,. 18). The resist layer 143 ′ may be a positive type or a negative type. The resist layer 143 ′ is made of a photosensitive resin, and the composition is preferably PMMA, SU8, or the like.

  Next, the resist layer 143 ′ is formed with an electron beam, a femtosecond laser, or the like to be exposed in accordance with the shapes of the plurality of nozzles 103, 103,. That is, when the resist layer 143 ′ is a positive type, the portions of the resist layer 143 ′ that overlap the through holes 142a of the ejection electrodes 142, 142,... Are exposed to the deep layer, and the plurality of nozzles 103, 103,. The middle part is exposed to the middle layer. On the other hand, when the resist layer 143 ′ is a negative type, the portions of the resist layer 143 ′ that become the plurality of nozzles 103, 103,. Here, instead of exposing the resist layer 143 ′ with an electron beam or a femtosecond laser, the resist layer 143 ′ may be exposed with visible light, ultraviolet light, excimer laser, i-line, g-line, or the like. In other words, the electromagnetic wave (light in a broad sense) used for the light exposure may be anything that makes the resist layer 143 ′ be exposed.

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) .

  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 developer decreases toward the substrate 141 side. Therefore, when the resist layer 143 ′ is a positive type, the nozzles 103, 103,... Having a substantially conical shape or a substantially frustoconical shape whose diameter increases toward the substrate 141 can be easily formed. Further, since the plurality of nozzles 103, 103,... Are formed by simply forming the resist layer 143 ′ and then exposing and developing the resist layer 143 ′, the production efficiency of the liquid discharge head is good.

  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 seen in a plan view is a shape opened at a portion to be the through holes 141c, 141c,. 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.

  The through holes 141c, 141c,... 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). Further, the bias power supply 30 and the discharge voltage power supply 29 are electrically connected to the wirings 144, 144,. Thereby, the liquid discharge head 100 is manufactured.

  If necessary, the surface layer of the nozzles 103, 103,. For example, the surface layer of the nozzles 103, 103,... May have water repellency by forming the resist layer 143 ′ with a photosensitive resin having water repellency (for example, fluorine-containing photosensitive resin). , 103,..., A metal film (for example, Ni, Au, Pt, etc.) is formed on the surface of the nozzle 103 with each nozzle hole 103a masked with a resist, and the metal film and fluorine-containing resin are formed. The surface layer of the nozzles 103, 103,... May have water repellency by forming a water repellent film formed by eutectoid plating (the resist masking the nozzle hole 103a is removed last). The photosensitive resin having water repellency is from several percent to several percent of UV-sensitive resin CYTOP manufactured by Asahi Glass Co., Ltd. in which a fluororesin is dissolved in PTFE, FEP dispersion or a perfluoro solvent having an average particle size of about 0.2 μm. 10% dispersion-mixed, and in dispersion, FEP having a low melting point is preferred. In addition, the dispersion includes MDF FEP 120-J (54 wt%, water dispersion) manufactured by DuPont Co., Ltd., and Fullon XAD911 (60 wt%, water dispersion) manufactured by Asahi Glass Co., Ltd. In addition, the resist polymer for F2 lithography is also a fluorine-containing photosensitive resin, in which fluorine is introduced into the polymer main chain and fluorine is introduced into the side chain.

  As in the above manufacturing method, the nozzles 103, 103,... Are formed simply by exposing and developing the resist layer 143 ′, so flexibility in the shape of the nozzle 103, manufacturing cost, and support for 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 microhole is formed in a silicon substrate based on the silicon substrate. Therefore, the shape of the nozzle can be flexibly changed in accordance with the manufacturing method of the present embodiment. This is more convenient, and it is considered that the manufacturing method of this embodiment is more advantageous for manufacturing a long line head, and the manufacturing cost of the head 100 is also more advantageous for this embodiment.

  Next, a driving method of the liquid discharge head 100 and a droplet discharge operation of the liquid discharge head 100 will be described. FIG. 22 is an explanatory diagram showing the relationship between the solution discharge operation and the voltage applied to the solution. FIG. 22A shows a state in which no discharge is performed, and FIG. 22B shows a discharge state.

  A chargeable solution is supplied to the in-nozzle flow paths 145 of the respective nozzles 103 via the liquid introduction port 119 and the manifold 120 by the supply pump, and in this state, the respective discharge electrodes are supplied by the respective bias power sources 30. A bias voltage is applied to the solution via 142. In such a state, the solution is charged, and a meniscus that is recessed in the form of a solution is formed at the tip of each nozzle 103 (FIG. 22A).

  Among the nozzles 103, 103,..., The nozzle 103 that discharges droplets is supplied with a pulse voltage from the discharge voltage power supply 29 via the discharge 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 to reduce the volume of the solution supply channel 101, thereby increasing the pressure of the solution in the solution supply channel 101. Accordingly, 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 protruding outside, and finally the surface tension of the solution. Against this, fine droplets are ejected to the counter electrode side (FIG. 22B).

  When the pulse voltage applied to the discharge electrode 142 is finished and the pulse voltage applied to the control electrode 121 is finished, the volume of the solution supply channel 101 is increased, so that the solution becomes concave at the tip of the nozzle 103. A depressed meniscus is formed, and a solution is supplied to the in-nozzle channel 145 of the nozzle 103 that ejects the liquid via the liquid inlet 119 and the manifold 120.

In the above description, the liquid chamber partition walls 106 and 107 are expanded by applying a pulse voltage to the control electrode 121 and the volume of the solution supply channel 101 is increased. Conversely, a pulse voltage is applied to the control electrode 121. Thus, the liquid chamber partition walls 106 and 107 may contract so 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 a pulse voltage is applied to the discharge electrode 142 during discharge, and the bias voltage is applied to the discharge electrode 142 when discharge is not performed. Sometimes a pulse voltage is applied to the control electrode 121. Further, as another head driving method, utilizing the fact that the discharge voltage by the meniscus position in the nozzle 103 are different, the meniscus voltage V ₀ is applied to the not ejected at the position which falls below the nozzle 103 distal to the ejection electrode 142, the control electrode 121 it is possible to control the discharge by controlling the pulse voltage meniscus position discharged from the discharge capable nozzle 103 tip voltage V ₀ by varying the volume of the solution supply channel 101 by applying to the.

In addition, a convex meniscus was 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 was removed by a heater or the like. A convex meniscus may be formed by boiling the film at the time of discharge and applying pressure to the solution. The convex meniscus forming means changes the pressure of the solution in the in-nozzle flow path 145 and may be any method that changes the volume of the solution supply channel 101, and bends the partition wall of the solution supply channel 101 by electrostatic force. it is also possible in the way formula Ru changing the Mase volume. Although it is possible to discharge without forming the convex meniscus, it is advantageous to form and discharge the convex meniscus in terms of safety and control cost in making the discharge voltage constant and droplet discharge control. is there.

  As a method of using the liquid discharge head 100 described above, for example, the liquid discharge head 100 (mainly, the liquid chamber structure 102 and the nozzle plate 104) is relatively positioned with respect to the base 200 in a plane parallel to the base 200. By selectively ejecting droplets from the tips of the respective nozzles 103 while being moved, 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. Further, since the plurality of nozzles 103, 103,... Are arranged in a line, the base material 200 is moved in a direction perpendicular to the nozzles 103, 103,. By selectively discharging droplets from the tip, a pattern in which droplets that have landed on the surface of the substrate 200 become dots can be formed on the surface of the substrate 200. Since the liquid discharge head 100 is provided with a plurality of nozzles 103, 103,..., The pattern can be formed quickly. In addition, the liquid discharge head 100 is formed with a circuit wiring pattern, a metal ultrafine particle wiring pattern, a carbon nanotube and its precursor and a catalyst array, a ferroelectric ceramic and its precursor patterning, It can be used for 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 ejection head 100 ejects droplets with the unprecedented minute diameter nozzle 103, the electric field is concentrated by the charged solution in the nozzle flow path 145, and the electric field strength is increased. Enhanced. For this reason, with a nozzle having a structure that does not concentrate the electric field as in the prior art (for example, an inner diameter of 100 [μm]), the voltage required for ejection becomes too high, and the nozzle with a minute diameter that has been virtually impossible to eject. The solution can be discharged at a lower voltage than before.

  And since it has a very small diameter, it is possible to easily control to reduce the discharge flow rate per unit time due to the low nozzle conductance, and the droplet diameter (see above) is sufficiently small without narrowing the pulse width. According to each condition, discharge of the solution by 0.8 [μm]) is realized.

  In addition, since the ejected droplets are charged, the vapor pressure is reduced even for very small droplets and the evaporation is suppressed, so the loss of droplet mass is reduced and the flight is stabilized. , Preventing a drop in droplet landing accuracy.

  Further, since the surface layers of the nozzles 103, 103,... Have water repellency, the solution in the nozzles 103, 103,. In addition, since the surface layer of the nozzles 103, 103,... Has water repellency, the adhesion of the solution around the nozzle hole 103a does not adversely affect the discharge of droplets. Further, since the surface layer of the nozzles 103, 103,... Has water repellency, the meniscus formed at the time of discharge is formed in a beautiful convex shape, and the droplets are stably discharged.

  Furthermore, since the 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, the liquid voltage is applied even if the pulse voltage applied to the ejection electrode 142 is low. Drops are ejected. That is, it is possible to discharge a solution with a nozzle having a minute diameter, which has been impossible to be discharged practically because the voltage required for the discharge becomes too high, at a lower voltage than before.

  In order to obtain an electrowetting effect on the nozzle 103, an electrode (for example, a metal film formed under the above-described water-repellent film) is provided on the outer periphery of the nozzle 103, or the nozzle flow path 145 is provided. An electrode may be provided on the inner surface of the substrate and covered with an insulating film. By applying a voltage to this electrode, the wettability of the inner surface of the in-nozzle channel 145 can be increased by the electrowetting effect on the solution to which the voltage is applied by the discharge electrode 142, It is possible to smoothly supply the solution to the flow path 145, and to discharge well, and to improve the responsiveness of discharge.

  In addition, the discharge voltage applying means 25 constantly applies a bias voltage to each discharge electrode 142 and discharges a droplet by using a pulse voltage as a trigger. It is good also as a structure which discharges by applying the continuous rectangular wave and switching the frequency level. In order to discharge droplets, charging of the solution is indispensable. Even if a discharge voltage is applied at a frequency exceeding the charging speed of the solution, discharging is not performed, and the frequency is changed so that the solution can be sufficiently charged. Discharging is performed. Therefore, when discharging is not performed, the discharge voltage is applied at a frequency higher than the frequency at which ejection can be performed, and control is performed to reduce the frequency to a frequency band where ejection can be performed only when ejection is performed, thereby controlling solution ejection. Is possible. In such a case, since the potential applied to the solution itself does not change, it is possible to further improve the time response and thereby improve the droplet landing accuracy.

[Theoretical Explanation of Electrostatic Suction Liquid Discharge Device]
Previously, it was considered impossible to discharge droplets beyond the range determined 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 liquid surface of the solution for enabling the discharge of droplets from the nozzle tip by electrostatic attraction, and is obtained by λ _C = 2πγh ² / ε ₀ V ² . It is done.

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 nozzle in the electrostatic attraction type ink jet system is reconsidered, and a micro droplet can be formed by utilizing Maxwell force or the like in an area that has not been attempted as impossible in the past. it can.

  Formulas that approximate the discharge conditions and the like for measures for realizing such a drive voltage drop and a small amount of discharge are derived and will be described below.

  The following description is applicable to the electrostatic suction type liquid ejecting apparatus described in the above embodiments of the present invention.

  Now, it is assumed that the conductive solution is injected into the nozzle of the inside d and 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 charge induced in the nozzle tip is concentrated in the hemisphere at the nozzle tip, and is approximately expressed 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。

Where Q: charge [C] induced at the tip of the nozzle, ε ₀ : dielectric constant [F / m] of vacuum, ε: dielectric constant of substrate (F / m), h: between nozzle and substrate Distance [m], r: radius of nozzle internal diameter [m], 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 is about 1 particularly when d << h.

Further, when the substrate as the base material is a conductor substrate, it is considered that a mirror image charge Q ′ having an opposite sign at a symmetrical position in the substrate is virtually induced. When the substrate is an insulator, a video charge Q ′ having an opposite sign is virtually induced at a symmetrical 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 assumes that the radius of curvature of the convex meniscus tip is R [m].

Given in. Here, k: proportional constant, which varies depending on the nozzle shape and the like, 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 simplicity, let d / 2 = R. This corresponds to a state in which the conductive solution swells in a hemispherical shape having the same radius as the nozzle radius due to surface tension at the nozzle tip.

（７）、（８）、（９）式よりα＝１とおいて、

と表される。 Consider the balance of pressure acting on the liquid at the nozzle tip. First, the electrostatic pressure is determined by assuming that the liquid area at the nozzle tip is S [m ² ].

From the equations (7), (8) and (9), α = 1 is set,

It is expressed.

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 conditions under which fluid discharge occurs due to 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.
From this relational expression, when the relationship between V and d is obtained,

Gives the lowest discharge voltage. That is, from Equation (6) and Equation (13),

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

  The dependency of the discharge limit voltage Vc on the nozzle having a certain radius d is shown in FIG. From this figure, it is clear that the discharge start voltage decreases as the nozzle diameter decreases in consideration of the electric field concentration effect due to the minute nozzles.

  In the conventional way of thinking about the electric field, that is, considering only the electric field defined by the voltage applied to the nozzle and the distance between the counter electrodes, the voltage required for ejection increases as the nozzle becomes smaller. On the other hand, if attention is paid to the local electric field intensity, the discharge voltage can be lowered by the miniaturization of the nozzle.

  The discharge by electrostatic suction is basically charging of a liquid (solution) at the nozzle end. The charging speed is considered to be 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 dielectric constant ε of the solution is 10 F / m and the solution conductivity σ is 10 ⁻⁶ S / m, τ = 1.854 × 10 ⁻⁶ sec. Alternatively, if the critical frequency is f _c [Hz],

It becomes. It is considered that it is impossible to respond to a change in the electric field having a frequency faster than f _c and ejection is impossible. When the above example is estimated, the frequency is about 10 kHz. At this time, when the nozzle radius is 2 μm and the voltage is 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 in the above example, since discharge at 10 kHz is possible, one cycle is possible. The minimum discharge amount can be about 10 fl (femtoliter, 1 fl = 10 ⁻¹⁶ l).

Each of the above-described embodiments is characterized by the electric field concentration effect at the nozzle tip and the action of the electrostatic force induced on the counter substrate as shown in FIG. For this reason, it is not always necessary to make the substrate or the substrate support conductive as in the prior art or to apply a voltage to these substrates or 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, the discharge of the solution can be facilitated by keeping the distance between the nozzle and the substrate at 500 [μm] or less. Although not shown, it is desirable to perform feedback control by detecting the nozzle position so as to keep the nozzle constant with respect to the substrate.

  Further, the base material may be placed and held on a conductive or insulating base material holder.

  FIG. 24 is a side sectional view of a nozzle portion of an electrostatic attraction 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 to the nozzle solution 3. The purpose of the electrode 15 is an electrode for controlling the electrowetting effect. If a sufficient electric field is applied to the insulator constituting the nozzle, the Electrowetting effect is expected to occur even without this electrode. However, in this basic example, the role of discharge control is also fulfilled by controlling more positively using this electrode. When the nozzle 1 is made of an insulator, the nozzle tube at the tip is 1 μm, the nozzle inner diameter is 2 μm, and the applied voltage is 300 V, an electrowetting effect of about 30 atm is obtained. This pressure is insufficient for discharge, but is meaningful 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 dependency of the discharge start voltage on the nozzle diameter 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. As the nozzle size became smaller, the discharge start voltage decreased, and it became clear that discharge was possible at a lower voltage than before.

  In each of the above embodiments, the solution discharge conditions are functions of the nozzle substrate distance (h), the applied voltage amplitude (V), and the applied voltage frequency (f), and satisfy certain conditions for each. This is necessary as a discharge condition. Conversely, if any one of the conditions is not met, the other parameters must be changed.

  This will be described with reference to FIG.

  First, for discharge, there is a certain critical electric field Ec that does not discharge unless the electric field is higher than that. This critical electric field varies depending on the nozzle diameter, the surface tension of the solution, the viscosity, and the like, and it is difficult to discharge below Ec. Above the critical electric field Ec, that is, at the dischargeable electric field strength, there is a generally proportional relationship between the nozzle substrate distance (h) and the amplitude (V) of the applied voltage. The applied voltage V can be reduced.

  On the other hand, when the distance h between the nozzle and the substrate is extremely increased and the applied voltage V is increased, even if the same electric field strength is maintained, bursting of the fluid droplets, that is, bursting occurs due to the action of corona discharge. End up.

FIG. 1A shows the electric field strength distribution when the nozzle diameter is φ0.2 [μm], and FIG. 1A shows the electric field strength 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 strength distribution when the nozzle diameter is set to φ0.4 [μm]. FIG. 2A shows the electric field strength distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. 2 (b) 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 strength distribution when the nozzle diameter is φ1 [μm], and FIG. 3A shows the electric field strength distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field strength 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 strength distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 5A shows the electric field strength distribution when the nozzle diameter is φ20 [μm]. FIG. 5A shows the electric field strength distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field strength distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. FIG. 6A shows the electric field strength distribution when the nozzle diameter is φ50 [μm], and FIG. 6A shows the electric field strength distribution when the distance between the nozzle and the counter electrode is set to 2000 [μm]. b) shows the electric field strength distribution when the distance between the nozzle and the counter electrode is set to 100 [μm]. The chart which shows the maximum electric field strength on each condition of FIGS. It is a diagram which shows the relationship between the nozzle diameter of a nozzle, and the maximum electric field strength when a liquid level exists at the tip position of a nozzle. The relationship between the nozzle diameter of the nozzle and the discharge start voltage at which the droplet discharged from the nozzle tip starts flying, the voltage value at the Rayleigh limit of the initial discharge droplet, and the ratio between the discharge start voltage and the Rayleigh limit voltage value is shown. FIG. It is a graph represented by the relationship between a nozzle diameter and the area | region of the strong electric field of a nozzle front-end | tip part. FIG. 3 is a perspective view showing a partially broken liquid discharge head as an embodiment of the present invention. FIG. 12 is a cross-sectional view showing the liquid chamber structure provided in the liquid discharge head shown in FIG. FIG. 12 is a bottom view showing a nozzle plate provided in the liquid discharge head shown in FIG. 11. FIG. 14 is a cross-sectional view taken along the cutting line AA ′ shown in FIG. 13. FIG. 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 the solution chamber is rounded, and FIG. FIG. 15C shows an example in which the tapered peripheral surface and the linear flow path are combined. It is drawing which showed the process of the manufacturing method of the said liquid discharge head. It is drawing which showed the process of the manufacturing method of the said liquid discharge head, FIG. 17 (A) is a top view, FIG.17 (B) is sectional drawing fractured | ruptured and shown by the cutting line BB '. It is drawing which showed the process of the manufacturing method of the said liquid discharge head. It is drawing which showed the process of the manufacturing method of the said liquid discharge head. It is drawing which showed the process of the manufacturing method of the said liquid discharge head. It is drawing which showed the process of the manufacturing method of the said liquid discharge head. FIG. 22A is an explanatory diagram showing a relationship between a solution discharge operation and a voltage applied to the solution. FIG. 22A shows a state where no discharge is performed, and FIG. 22B shows a discharge state. As an embodiment of the present invention, it is shown to explain the calculation of the electric field strength of the nozzle. 1 is a side sectional view of a liquid discharge mechanism as an example of the present invention. It is a figure explaining the discharge conditions by the relationship of distance-voltage in the liquid discharge apparatus of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Liquid discharge head 102 Liquid chamber structure 101 Solution supply channel 104 Nozzle plate 103 Nozzle 106 1st liquid chamber partition (piezoelectric element, convex meniscus formation means)
107 Second liquid chamber partition wall (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 application means

Claims (19)

In a manufacturing method of manufacturing an electrostatic suction type liquid discharge head having a plurality of nozzles that discharge a solution as droplets charged from a nozzle tip,
A plurality of discharge electrodes for applying a discharge voltage is formed on the substrate, a photosensitive resin layer is formed on the substrate so as to cover the whole of the plurality of discharge electrodes, and the photosensitive resin layer is exposed and exposed. By developing, a nozzle having a projecting shape in which the photosensitive resin layer is erected with respect to the substrate corresponding to each discharge electrode, and the inner diameter of the tip of the nozzle is greater than 0.2 μm and less than 4 μm In addition, a flow path in the nozzle is formed in each of the nozzles so as to pass from the tip of the nozzle to the discharge electrode, and is joined to a solution supply channel corresponding to the plurality of nozzles. A method of manufacturing an electrostatic suction type liquid discharge head.   2. The method of manufacturing an electrostatic attraction type liquid discharge head according to claim 1, wherein when forming the plurality of nozzles, the shape of each nozzle is a frustoconical shape whose outer diameter becomes narrower toward the tip.   3. The method of manufacturing an electrostatic suction type liquid discharge head according to claim 1, wherein, in forming the plurality of discharge electrodes, a through hole extending to the substrate is formed in each discharge electrode.   A positive type is used as the photosensitive resin layer, and at the time of exposure of the photosensitive resin layer, a portion overlapping each through hole is exposed to a deep layer, and a portion between the plurality of nozzles is exposed to a middle layer. A method for manufacturing an electrostatic attraction type liquid discharge head according to claim 3.   4. The liquid supply channel according to claim 1, wherein at least an inner surface of each of the solution supply channels is insulative and a control electrode for controlling a meniscus position of a solution at a nozzle tip is provided on the solution supply channel. The manufacturing method of the electrostatic attraction | suction type liquid discharge head of item.   6. The method of manufacturing an electrostatic suction type liquid discharge head according to claim 5, wherein the solution supply channel is formed of a piezoelectric material. Electrostatic suction type method for producing a liquid discharge head according to any one of claims 1 6, wherein the photosensitive resin layer is a fluorine-containing. In the drive method which drives the electrostatic attraction type liquid discharge head manufactured by the manufacturing method of the electrostatic attraction type liquid discharge head according to any one of claims 1 to 7 ,
An electrostatic attraction type characterized in that a tip portion of each nozzle is opposed to a substrate, a chargeable solution is supplied to each solution supply channel, and a discharge voltage is applied to each of the plurality of discharge electrodes. A method for driving a liquid discharge head. The method of driving an electrostatic suction type liquid discharge head according to claim 8 , wherein the solution in each of the nozzle flow paths forms a state in which the solution protrudes from the tip of the nozzle. 10. The electrostatic attraction type according to claim 9 , wherein a discharge voltage is applied to the discharge electrode when the solution in the flow path in each nozzle forms a state in which the solution rises from the tip of the nozzle. A method for driving a liquid discharge head. Comprising an electrostatic attraction type liquid ejection head manufactured by the manufacturing method of an electrostatic attraction type liquid ejection head according to any one of claims 1 to 7, facing the tip portion of each of the nozzle to the substrate An electrostatic suction type liquid discharge device that can be arranged as
Solution supply means for supplying a chargeable solution to each of the flow paths in the nozzle;
An electrostatic suction type liquid ejection apparatus, further comprising ejection voltage application means for applying an ejection voltage to each of the plurality of ejection electrodes. The electrostatic attraction type liquid according to claim 11 , further comprising a convex meniscus forming means for forming a state in which the solution in each of the flow paths in the nozzles is raised from the tip of the nozzle. Discharge device. The discharge voltage applying means applies the discharge voltage to the discharge electrode when the convex meniscus forming means forms a state in which the solution in the flow path in each nozzle bulges from the tip of the nozzle. The electrostatic attraction type liquid ejection device according to claim 12 . The convex meniscus forming means has a piezoelectric element provided corresponding to each nozzle, and each piezoelectric element changes the pressure of the solution in the flow path in the nozzle by deformation. The electrostatic suction type liquid ejection device according to claim 12 or 13 . In a manufacturing method for manufacturing a nozzle plate having a plurality of nozzles for discharging a solution as charged droplets from a nozzle tip,
A plurality of discharge electrodes for applying a discharge voltage is formed on the substrate, a photosensitive resin layer is formed on the substrate so as to cover the whole of the plurality of discharge electrodes, and the photosensitive resin layer is exposed and exposed. By developing, a nozzle having a projecting shape in which the photosensitive resin layer is erected with respect to the substrate corresponding to each discharge electrode, and the inner diameter of the tip of the nozzle is greater than 0.2 μm and less than 4 μm In addition, the nozzle plate flow path is formed in each nozzle so as to pass from the tip of the nozzle to the discharge electrode. 16. The method of manufacturing a nozzle plate according to claim 15 , wherein when forming the plurality of nozzles, the shape of each nozzle is a frustoconical shape whose outer diameter becomes narrower toward the tip. Wherein the formation of the plurality of discharge electrodes, method of manufacturing a nozzle plate according to claim 15 or 16 a through hole through to the substrate and forming the respective discharge electrodes. A positive type is used as the photosensitive resin layer, and at the time of exposure of the photosensitive resin layer, a portion overlapping each through hole is exposed to a deep layer, and a portion between the plurality of nozzles is exposed to a middle layer. The method for manufacturing a nozzle plate according to claim 17 . The method for producing a nozzle plate according to any one of claims 15 to 18 , wherein the photosensitive resin layer contains fluorine.

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