JP2010143106A - Nozzle substrate, liquid droplet delivery head, liquid droplet delivery device, and method of manufacturing those - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle substrate, a liquid droplet delivery head, and a liquid droplet delivery device, restraining a liquid droplet protection film formed on a liquid droplet delivery face of the nozzle substrate from being separated or damaged, and enhancing durability of the nozzle substrate against a liquid droplet, and a method of manufacturing those. <P>SOLUTION: This nozzle substrate 1 is formed with a nozzle hole 11 for delivering the liquid droplet while penetrating a silicon substrate 100, and includes the second liquid droplet protection film 14 formed on a liquid droplet delivery face 100a of the silicon substrate 100, and a conductive terminal 13 formed in a liquid droplet delivery face 100a side, and having a withstand voltage lower than that of the second liquid droplet protection film 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nozzle substrate having a nozzle hole for discharging a droplet, a droplet discharge head, a droplet discharge device, and a method for manufacturing the same.

  For example, a droplet discharge head (inkjet head) mounted on a droplet discharge apparatus such as a droplet discharge type printer generally includes a nozzle substrate on which nozzle holes for discharging ink droplets are formed. A cavity substrate (also referred to as a flow channel substrate) in which ink flow paths such as a discharge chamber and a reservoir are formed is bonded to the substrate, and ink droplets are discharged from selected nozzle holes by applying pressure to the discharge chamber by the drive unit. It is configured as follows. As the driving means, there are a method using an electrostatic force, a piezoelectric method using a piezoelectric element, a method using a heating element, and the like. In such a droplet discharge type droplet discharge apparatus, printing is performed by moving a droplet discharge head relative to a printing material (paper or the like) and discharging the droplet to a predetermined position of the printing material. Is.

  In recent years, there has been a demand for an inkjet head having a structure having a plurality of nozzle rows for the purpose of increasing the printing speed and color, and in addition, the nozzles have a higher density and a longer length (per one row). The number of nozzles is increasing), and the number of actuators in the inkjet head is increasing. From such a background, an inkjet head excellent in high-precision processing and high durability of a nozzle is required, and various devices and proposals have been made conventionally. Among these, there are the following conventional techniques for covering the droplet discharge surface of the nozzle substrate, the inner surface of the nozzle hole, and the surface (bonding surface) in contact with the liquid flow path on the opposite side.

  For example, in Patent Document 1, a hydrophobic coating is continuously formed from the inner surface of a nozzle hole composed of a channel wafer and a heater wafer to the nozzle surface (discharge surface), and the hydrophobic coating is formed only on the inner surface of the nozzle hole. It has also been proposed to form a hydrophilic coating thereon.

JP-A-5-124200

As described above, the droplet discharge head mounted on the droplet discharge device is relatively moved with respect to the substrate (paper or the like). For this reason, the nozzle substrate of the droplet discharge head and the substrate to be printed slide to generate static electricity, and electrostatic discharge occurs between the nozzle substrate and the substrate to be printed.
Due to such electrostatic discharge, there is a problem that the droplet protective film (coating treatment) formed on the ejection surface of the nozzle substrate is peeled off or damaged.

  In particular, in the case of a nozzle substrate made of silicon, when a droplet protective film (silicon oxide film or the like) is peeled off or broken, silicon is eroded by, for example, alkaline ink droplets (discharge liquid), and the durability against the droplets is increased. There was a problem that it decreased.

  The present invention has been made to solve the above-described problems, and can suppress the occurrence of peeling or breakage of the droplet protective film formed on the droplet discharge surface of the nozzle substrate. It is an object of the present invention to obtain a nozzle substrate, a droplet discharge head, a droplet discharge device, and a manufacturing method thereof that can improve the durability of the nozzle substrate.

A nozzle substrate according to the present invention is a nozzle substrate in which a nozzle hole for ejecting droplets is formed by penetrating a silicon substrate, and a droplet protective film formed on a droplet ejection surface of the silicon substrate; And a terminal portion formed on the droplet discharge surface side and having a dielectric strength lower than that of the droplet protective film.
According to the present invention, since the terminal portion having a lower withstand voltage than the droplet protective film is provided, the static electricity charged on the printed material can be discharged to the terminal portion. For this reason, it is possible to suppress the occurrence of peeling or breakage of the droplet protective film formed on the droplet discharge surface of the nozzle substrate.
Further, by suppressing the occurrence of peeling or breakage of the droplet protective film, the silicon substrate can be prevented from being eroded by the droplets, and the durability of the nozzle substrate against the droplets can be improved.

In the nozzle substrate according to the present invention, the terminal portion is formed between the nozzle hole and an end portion of the nozzle substrate.
According to the present invention, since the terminal portion is formed between the nozzle hole and the end portion of the nozzle substrate, it is possible to suppress the occurrence of peeling or breakage of the droplet protective film formed in the vicinity of the nozzle hole and the nozzle hole. Can do.

In the nozzle substrate according to the present invention, a nozzle hole array in which a plurality of the nozzle holes are arranged is formed, and the terminal portion is formed wide in the width direction of the nozzle hole array.
According to the present invention, since the terminal portion is formed wide in the width direction of the nozzle hole row, each nozzle hole constituting the nozzle hole row and the droplet protective film formed in the vicinity thereof are not peeled off or damaged. Can be suppressed.

In the nozzle substrate according to the present invention, the terminal portion is formed of a material capable of ohmic contact with the silicon substrate, and is electrically connected to the silicon substrate.
According to the present invention, the static electricity discharged to the terminal portion can be caused to flow to the silicon substrate regardless of whether the electrostatic charge charged on the substrate has a positive or negative charge polarity.

In the nozzle substrate according to the present invention, the terminal portion is mainly composed of a refractory metal silicide film or ITO film.
According to the present invention, since the terminal part is mainly composed of a refractory metal silicide film, the adhesion between the terminal part and the silicon substrate can be improved.
In addition, since the ITO film is general-purpose as an electrode material, the manufacturing cost and the like can be reduced.

In the nozzle substrate according to the present invention, a portion of the droplet discharge surface of the silicon substrate where the droplet protective film is not formed is used as the terminal portion.
According to the present invention, since the portion where the droplet protective film is not formed on the droplet discharge surface of the silicon substrate is used as the terminal portion, the manufacturing process for forming the terminal portion can be omitted, and the terminal portion can be easily formed. It is possible to reduce the manufacturing cost and the like.

In the nozzle substrate according to the present invention, at least the surface of the terminal portion has a coating film having a dielectric strength lower than that of the droplet protective film.
According to the present invention, since the coating film having a lower withstand voltage than the droplet protective film is provided, the durability of the nozzle substrate against droplets can be further improved, and static electricity charged on the printed material is discharged to the terminal portion. be able to.

In addition, a droplet discharge head according to the present invention includes the nozzle substrate described above.
According to the present invention, since the nozzle substrate is provided, it is possible to suppress the occurrence of peeling or breakage of the droplet protective film formed on the droplet discharge surface of the nozzle substrate, and the nozzle substrate against the droplets. A droplet discharge head capable of improving durability can be obtained.

In the liquid droplet ejection head according to the present invention, the terminal portion is grounded to a housing in which the liquid droplet ejection head is accommodated.
According to the present invention, since the terminal portion is grounded to the casing in which the droplet discharge head is accommodated, the electric charge discharged to the terminal portion can be released to the casing.

A droplet discharge device according to the present invention is equipped with the above-described droplet discharge head.
According to the present invention, since the above-described droplet discharge head is mounted, it is possible to suppress the occurrence of peeling or damage of the droplet protective film formed on the droplet discharge surface of the nozzle substrate. A droplet discharge head that can improve the durability of the nozzle substrate can be obtained.

In the liquid droplet ejection apparatus according to the present invention, the liquid droplet ejection head is mounted such that the terminal portion is disposed upstream of the nozzle hole in the conveyance direction of the printed material.
According to the present invention, since the terminal portion is arranged on the upstream side in the conveyance direction of the printing material from the nozzle hole, the static electricity charged on the printing material is discharged to the terminal portion before the printing material is conveyed to the vicinity of the nozzle. be able to. For this reason, peeling or breakage of the droplet protective film formed near the nozzle hole and the nozzle hole can be suppressed.

The method for manufacturing a nozzle substrate according to the present invention includes a step of forming a nozzle hole by penetrating a silicon substrate, and a portion of the droplet discharge surface of the silicon substrate where a terminal portion is to be formed is a first mask member. A step of forming a droplet protective film on the droplet discharge surface, a step of removing the first mask member, and a portion other than a portion of the droplet discharge surface of the silicon substrate where the terminal portion is formed. Are covered with a second mask member, and a step of forming a terminal portion having a dielectric strength lower than that of the droplet protective film and a step of removing the second mask member are included.
According to the present invention, the droplet protective film and the terminal portion can be formed on the droplet discharge surface of the silicon substrate. For this reason, static electricity charged on the substrate can be discharged to the terminal portion, and peeling or damage of the droplet protective film can be suppressed. Further, by suppressing the occurrence of peeling or breakage of the droplet protective film, the silicon substrate can be prevented from being eroded by the droplets, and the durability of the nozzle substrate against the droplets can be improved.
In addition, since the terminal portion is formed using the first mask member and the second mask member, the manufacturing process can be simplified and the manufacturing cost can be reduced as compared with the case where the photolithography method is used. it can.

Further, the method for manufacturing a nozzle substrate according to the present invention includes a step of forming a coating film having a lower withstand voltage than the droplet protective film on the droplet protective film and the terminal portion on the droplet discharge surface. In addition.
According to the present invention, since the coating film is formed on the droplet protective film and the terminal portion on the droplet discharge surface, it is possible to further improve the durability of the nozzle substrate against the droplet. In addition, since the coating film having a lower withstand voltage than the droplet protective film is formed, static electricity charged on the printed material can be discharged to the terminal portion.

In the method for manufacturing a nozzle substrate according to the present invention, the terminal portion is formed by sputtering.
According to the present invention, since the terminal portion is formed by sputtering, the terminal portion can be formed at a relatively low temperature step in the film forming step. As a result, when the nozzle substrate is manufactured, a film can be formed in a state where a support substrate such as a resin is adhered to the nozzle substrate, handling properties and processing efficiency are improved, and costs can be reduced.

The method for manufacturing a nozzle substrate according to the present invention includes a step of forming a nozzle hole by penetrating a silicon substrate, and a portion of the droplet discharge surface of the silicon substrate where a terminal portion is to be formed is a first mask member. Forming a droplet protective film on the droplet discharge surface, removing the first mask member, and covering the droplet discharge surface with a lower withstand voltage than the droplet protective film. Forming a film, and using the portion of the droplet discharge surface where the droplet protective film is not formed as the terminal portion.
According to the present invention, the portion of the droplet discharge surface of the silicon substrate where the droplet protective film is not formed is used as the terminal portion. For this reason, static electricity charged on the substrate can be discharged to the terminal portion, and peeling or damage of the droplet protective film can be suppressed.
In addition, since a coating film with a lower withstand voltage than the droplet protective film is formed on the droplet discharge surface, the portion of the droplet discharge surface where the droplet protective film is not formed is prevented from eroding the silicon substrate by the droplet. And the durability of the nozzle substrate against droplets can be improved.
Further, since the portion of the droplet discharge surface of the silicon substrate where the droplet protective film is not formed is used as the terminal portion, the manufacturing process for forming the terminal portion can be omitted, and the terminal portion can be easily formed. Thus, the manufacturing cost can be reduced.

In the method for manufacturing a nozzle substrate according to the present invention, the droplet protective film is formed by plasma CVD.
According to the present invention, since the droplet protective film is formed by plasma CVD, the droplet protective film can be formed at a relatively low temperature step in the film forming step. As a result, when the nozzle substrate is manufactured, a film can be formed in a state where a support substrate such as a resin is adhered to the nozzle substrate, handling properties and processing efficiency are improved, and costs can be reduced.

Further, a method for manufacturing a droplet discharge head according to the present invention is a method for manufacturing a droplet discharge head by applying the above-described method for manufacturing a nozzle substrate.
According to the present invention, since the droplet discharge head is manufactured by applying the nozzle substrate manufacturing method described above, the occurrence of peeling or breakage of the droplet protective film formed on the droplet discharge surface of the nozzle substrate is suppressed. Thus, a droplet discharge head that can improve the durability of the nozzle substrate against droplets can be manufactured.

In addition, a method for manufacturing a droplet discharge device according to the present invention is a method for manufacturing a droplet discharge device by applying the method for manufacturing a droplet discharge head described above.
According to the present invention, since the droplet discharge device is manufactured by applying the method for manufacturing the droplet discharge head, the droplet protective film formed on the droplet discharge surface of the nozzle substrate is peeled off or broken. It is possible to manufacture a droplet discharge device that can suppress the durability of the nozzle substrate against droplets.

Embodiment 1 FIG.
Hereinafter, a droplet discharge head including a nozzle substrate according to the present invention will be described with reference to the drawings. Here, as an example of a droplet discharge head, an electrostatic drive type inkjet head will be described with reference to FIGS. The present invention is not limited to the structure and shape shown in the following drawings, and the driving method can also be applied to a droplet discharge head that discharges droplets by other different driving methods. .

The present invention is not limited to the structure and shape shown in the following figures. Moreover, in the following drawings, in order to make it easy to see, the relationship of the size of each component may be different from the actual one. Further, description will be made with the upper side of the figure as the upper side and the lower side as the lower side.
Further, as an example of the electrostatic actuator, a face discharge type liquid droplet discharge head is shown, but the present invention is not limited to this and can be applied to an edge discharge type. Further, a droplet discharge head and a droplet discharge device of a different drive method (for example, using a piezoelectric element or a heating element) other than the electrostatic drive method as a drive method for supplying energy for droplet discharge It can also be applied to.

First, the structure of an inkjet head is shown in FIGS.
FIG. 1 is an exploded perspective view showing a schematic configuration of an ink jet head according to Embodiment 1 of the present invention, and a part thereof is shown in cross section. FIG. 2 is a partial cross-sectional view of the inkjet head showing a schematic configuration of the right half of FIG. 1 in the assembled state. FIG. 3 is an enlarged cross-sectional view of the nozzle hole portion of FIG. FIG. 4 is a top view of the nozzle substrate of FIG.

  As shown in FIGS. 1 to 4, the inkjet head 10 according to the present embodiment includes a nozzle substrate 1 provided with a plurality of nozzle holes 11 formed at a predetermined pitch and conductive terminals 13 as terminal portions. The cavity substrate 2 provided with the ink supply path independently for each nozzle hole 11 and the electrode substrate 3 provided with the individual electrodes 31 facing the vibration plate 22 of the cavity substrate 2 are bonded together. It is configured.

  The nozzle substrate 1 is made from a silicon substrate 100. For example, a single crystal silicon substrate is used. A polycrystalline silicon (polysilicon) substrate may be used. A method for manufacturing the nozzle substrate 1 will be described in detail later.

As will be described in detail with reference to FIG. 3, the nozzle substrate 1 is provided with nozzle holes 11 for penetrating the silicon substrate 100 and discharging liquid droplets such as ink droplets. The nozzle hole 11 includes a first nozzle hole 11a that discharges droplets and a second nozzle hole 11b that introduces droplets.
The first nozzle hole 11a is formed in a cylindrical shape with a small diameter (about 20 to 30 μm) perpendicular to the surface (droplet ejection surface) 100a of the nozzle substrate 1. The second nozzle hole 11b is provided coaxially with the first nozzle hole 11a, has a larger cross-sectional area than the first nozzle hole 11a, and has a cylindrical cross-sectional shape. Thus, by making the nozzle hole 11 have a two-stage vertical hole, the ink droplet discharge direction can be aligned with the central axis direction of the nozzle hole 11, and stable ink discharge characteristics can be exhibited. it can. That is, there is no variation in the flying direction of the ink droplets, there is no scattering of the ink droplets, and variations in the ejection amount of the ink droplets can be suppressed. In addition, the nozzle density can be increased. Here, an example in which the nozzle hole 11 has a structure having two stages of holes is shown, but a plurality of stages may be formed in stages, and the cross-sectional area of the nozzle holes is continuous toward the discharge direction. It is good also as the shape which decreases to. Further, the step portion between the first nozzle hole 11a and the second nozzle hole 11b may be formed in a tapered shape.

Here, as shown in FIG. 3, a first liquid made of, for example, SiO ₂ is formed on the bonding surface 100b of the nozzle substrate 1 with the cavity substrate 2 (the surface opposite to the droplet discharge surface 100a) and the inner wall of the nozzle hole 11. The droplet protective film 12 is continuously formed. Therefore, the inner surface of the nozzle hole 11 has hydrophilicity.

On the droplet discharge surface 100a, a second droplet protective film 14 made of, for example, SiO ₂ is formed with a film thickness of about 0.2 to 2 μm. A conductive terminal 13 having conductivity is formed on a part of the droplet discharge surface 100a with a film thickness of about 0.2 to 2 μm. That is, the conductive terminal 13 having conductivity has a lower withstand voltage against static electricity than the second droplet protective film 14. By forming the conductive terminal 13 having a low withstand voltage against static electricity in this way, it is possible to easily discharge the static electricity charged on the printed material to the conductive terminal 13, and discharge to the second droplet protective film 14. Can be suppressed.

  The conductive terminal 13 is formed of a material capable of ohmic contact with the silicon substrate 100 and is electrically connected to the silicon substrate 100. For this reason, the static charge discharged to the conductive terminal 13 flows into the silicon substrate 100 regardless of whether the electrostatic charge charged on the printing material has a positive or negative charge polarity. As the material of the conductive terminal 13, for example, a refractory metal silicide film having good affinity with silicon is used. Thereby, the adhesiveness between the conductive terminal 13 and the silicon substrate 100 can be improved. For example, an ITO (Indium Tin Oxide) film may be used. Since the ITO film is general-purpose as an electrode material, the manufacturing cost and the like can be reduced.

The conductive terminal 13 is formed between the nozzle hole 11 and the substrate end of the nozzle substrate 1 as shown in FIG. For example, it is formed at a position away from the vicinity of the nozzle hole 11. When the conductive terminal 13 is formed in the vicinity of the nozzle hole 11, it is necessary to form the protective film at the end of the nozzle hole 11 and the conductive terminal 13 with high accuracy, which increases manufacturing costs and the like. It is desirable to form it outside the vicinity of the nozzle hole 11.
In addition, the conductive terminal 13 is formed wide in the width direction of the nozzle hole row composed of the plurality of nozzle holes 11. For example, the vertical width (width in the width direction of the nozzle hole row) is formed to be longer than at least the width of the nozzle hole row, and the horizontal width is formed to be about 20 to 40 μm. Note that the shape of the conductive terminal 13 is not limited to this, and any shape may be used as long as the conductive terminal 13 is located upstream of each nozzle hole 11 in the conveyance direction of the substrate. For example, the conductive terminal 13 may be divided into a plurality of pieces.

  Further, the conductive terminal 13 is grounded via a silicon substrate 100 to a casing (not shown) in which the inkjet head 10 is accommodated. For example, as shown in FIG. 2, the silicon substrate 100 and the housing are electrically connected by bringing the grounding portion 28 at the substrate end of the nozzle substrate 1 into contact with the housing. As a result, the charge due to static electricity flowing into the silicon substrate 100 from the conductive terminal 13 can be released to the housing. The connection of the housing is not limited to this, and any connection is possible as long as the conductive terminal 13 and the housing are electrically connected. For example, the common electrode 27 is grounded and the silicon substrate 100 and the common electrode 27 are connected. May be electrically connected. Further, the conductive terminal 13 and the housing may be directly connected.

Further, in order to improve water repellency on the droplet discharge surface 100a side, a water repellent film 15 serving as a coating film is formed on the second droplet protective film 14 and the conductive terminal 13. Yes. The water repellent film 15 is formed so as to have a lower withstand voltage against static electricity than the second droplet protective film 14. That is, on the droplet discharge surface 100a, the portion where the water repellent film 15 and the conductive terminal 13 are formed is more static than the portion where the water repellent film 15 and the second droplet protective film 14 are formed. Therefore, the withstand voltage against is reduced.
The water repellent film 15 is preferably composed mainly of a fluorine-containing organosilicon compound. The reason is that the hydroxyl group on the surface of the second droplet protective film 14 is firmly bonded to a hydrolyzing group such as a methoxy group of the fluorine-containing organosilicon compound, so that the second droplet protective film 14 and the surface thereof are bonded. This is because the adhesion to the formed water-repellent film 15 is improved.

  The cavity substrate 2 is bonded and bonded to the nozzle substrate 1 configured as described above. The cavity substrate 2 is made from a silicon substrate. For example, a single crystal silicon substrate is used. In the cavity substrate 2, ink channel grooves communicating with each of the nozzle holes 11 are formed by anisotropic wet etching. The ink channel groove includes a discharge recess 210 serving as the discharge chamber 21 with the diaphragm 22 serving as a bottom wall, a reservoir recess 230 serving as the reservoir 23 serving as a common ink chamber, and the reservoir recess 230 and each discharge recess 210. An orifice recess 240 is formed to be an orifice 24 that communicates with each other. The diaphragm 22 can be formed with a high accuracy by forming it with a boron diffusion layer. The orifice 24 can also be provided on the nozzle substrate 1 side. In this case, the orifice 24 is formed as a narrow groove-like recess communicating with the reservoir recess 230 and each discharge recess 210 on the joint surface 100b.

In addition, an insulating film 25 for preventing a short circuit, a dielectric breakdown, or the like is formed on the cavity substrate 2 over the entire bonding surface with the electrode substrate 3. As the insulating film 25, SiO ₂ or SiN, or a so-called High-k material such as Al ₂ O ₃ or HfO ₂ is used according to the purpose. In particular, when a high-k material is used, the relative dielectric constant is larger than that of SiO ₂ , so that the pressure generated by the actuator can be increased, and the density can be further increased. The insulating film 25 may be formed on the opposing surface of the individual electrode 31 as necessary. Furthermore, the cavity substrate 2 over the entire surface of the ink flow channel side is ink-resistant protective film 26 is a thermal oxidation method, a sputtering method of SiO ₂ as the hydrophilic film is formed by CVD (Chemical Vapor Deposition) method or the like, such as Pt A common electrode 27 made of a metal film is formed on the cavity substrate 2.

  The electrode substrate 3 is anodic bonded to the cavity substrate 2 described above. The electrode substrate 3 is made of, for example, a borosilicate glass substrate. A concave portion 32 is formed by etching at a position facing the diaphragm 22 of the glass substrate, and an individual electrode 31 generally made of ITO (Indium Tin Oxide) is formed on the bottom surface of each concave portion 32 by sputtering. It is formed by. The individual electrode 31 has a lead part 31a and a terminal part 31b connected to a flexible wiring board (not shown). As shown in FIG. 2, these terminal portions 31b are exposed in an electrode extraction portion 36 in which the end portion of the cavity substrate 2 is opened for wiring. Further, an ink supply port 33 communicating with the reservoir 23 for supplying ink is formed on the electrode substrate 3 by a sandblast method or the like. The ink supply port 33 is connected to an ink tank (not shown).

The electrode substrate 3 and the cavity substrate 2 are anodically bonded so that the individual electrode 31 and the diaphragm 22 are disposed to face each other with a predetermined (for example, 0.1 μm) gap 34. Thus, the electrostatic actuator 4 that can apply a required pressure to the discharge chamber 21 is configured by the individual electrode 31 and the diaphragm 22 having the insulating film 25 facing each other via the gap 34. Note that the open end of the gap 34 is hermetically sealed with a sealing material 35 such as an epoxy resin or an inorganic oxide by a sputtering method so that moisture or dust does not enter inside. Thereby, the drive durability and reliability of the electrostatic actuator 4 are improved.
Then, as shown in a simplified manner in FIG. 2, in order to drive the electrostatic actuator 4, an FPC (Flexible Print Circuit) on which a driving means 5 such as a driver IC is mounted is connected to a conductive adhesive at an electrode extraction portion 36. Thus, wiring connection is made between the terminal portion 31 b of each individual electrode 31 and the metal common electrode 27 provided on the cavity substrate 2. The inkjet head 10 is completed as described above.

Here, the operation of the inkjet head 10 will be described. In order to eject ink droplets from an arbitrary nozzle hole 11, the electrostatic actuator 4 corresponding to the nozzle hole 11 is driven as follows.
A pulse voltage is applied between the individual electrode 31 and the diaphragm 22 which is a common electrode by the driving means 5. The diaphragm 22 is attracted and brought into contact with the individual electrode 31 side by the electrostatic force generated by the application of the pulse voltage, generates a negative pressure in the discharge chamber 21, sucks the ink in the reservoir 23, and vibrates the ink (meniscus). Vibration). When the voltage is released when the vibration of the ink becomes substantially maximum, the vibration plate 22 is detached from the individual electrode 31, and the ink is pushed out from the nozzle hole 11 by the restoring force of the vibration plate 22 at that time. Is discharged.

  According to the inkjet head 10 according to the present embodiment, since the conductive terminal 13 is provided on the droplet discharge surface 100a of the nozzle substrate 1, the static electricity charged on the printed material can be discharged to the conductive terminal 13. For this reason, it is possible to suppress the occurrence of peeling or breakage of the second droplet protective film 14 formed on the droplet discharge surface 100a of the nozzle substrate 1. Further, by suppressing the occurrence of peeling or breakage of the second droplet protective film 14, it is possible to prevent the silicon substrate 100 from being eroded by the droplets, and to improve the durability of the nozzle substrate 1 against the droplets. Can do. Further, since the durability of the nozzle substrate 1 against droplets is improved, even if the droplet material is corrosive to silicon, the droplet material is resistant to the second droplet protective film 14 made of a silicon oxide film. Can be used, and the selection range of the droplet material can be widened.

  Further, since the conductive terminal 13 is formed between the nozzle hole 11 and the end portion of the nozzle substrate 1, static electricity charged on the printed material is transferred to the conductive terminal 13 before the printed material is conveyed to the nozzle hole 11. It is possible to prevent the peeling or breakage of the second droplet protective film 14 formed in the vicinity of the nozzle hole 11 and the nozzle hole 11.

  Further, since the conductive terminal 13 is formed wide in the width direction of the nozzle hole row, each nozzle hole constituting the nozzle hole row and the second droplet protective film 14 formed in the vicinity thereof are peeled off or damaged. Occurrence can be suppressed.

  Further, since the conductive terminal 13 is formed of a material capable of making ohmic contact with the silicon substrate 100 and is electrically connected to the silicon substrate 100, the electrostatic charge charged on the printed material has a positive or negative charge polarity. Even so, the static electricity discharged to the conductive terminal 13 can flow to the silicon substrate 100.

  In addition, since the water-repellent film 15 is formed on the second droplet protective film 14 and the conductive terminal 13, the durability of the nozzle substrate against the droplets can be further improved, and static electricity charged on the printed material can be obtained. Can be discharged to the conductive terminal 13.

  Further, since the conductive terminal 13 is grounded to the casing in which the inkjet head 10 is accommodated via the silicon substrate 100, the charge due to static electricity discharged to the conductive terminal 13 can be released to the casing.

  In addition, since the conductive terminal 13 is formed on the droplet discharge surface 100a with substantially the same film thickness as the second droplet protective film 14, the conductive terminal 13 does not interfere with the conveyance of the printed material and is not formed on the printed material. The charged static electricity can be discharged to the conductive terminal 13.

  Next, the manufacturing method of the inkjet head 10 comprised as mentioned above is demonstrated using FIGS.

5 to 11 are partial cross-sectional views illustrating the manufacturing process of the nozzle substrate 1 of the first embodiment.
First, based on FIGS. 5-11, the procedure of the manufacturing method of the nozzle substrate 1 in embodiment is demonstrated. Actually, a plurality of nozzle substrates 1 of droplet discharge heads are simultaneously formed from a silicon wafer. However, FIGS. 5 to 11 show only a portion for forming a nozzle hole 11 as a part thereof. . Here, the following description will be made with specific numerical values. However, these numerical values represent an example and are not limited to these values.

(A) First, a silicon oxide film 101 serving as a film (resist) for protecting the silicon substrate 100 when etching is performed on the silicon substrate 100 having a thickness of about 725 μm, for example, is formed on the entire surface by about 0.5 μm (see FIG. 5 (a)).
The film forming method is not particularly limited, but here, for example, a thermal oxidation method is used in which the silicon substrate 100 is exposed to an oxygen and water vapor atmosphere at a high temperature (about 1075 ° C.).

(B) Next, in order to perform patterning by selectively etching the silicon oxide film 101, a photolithographic method is used for a bonding surface (referred to as a surface bonded to the cavity substrate 2) 100 b of the silicon substrate 100. A photosensitive agent to be the resist film 102 is applied. Then, a portion of the photoresist film 102 that becomes the second nozzle hole 11b is removed by exposure and development, and pattern formation (patterning) is performed (FIG. 5B).

(C) Then, the silicon oxide film 101 is etched by, for example, dry etching or wet etching (BHF: for example, a liquid in which a hydrofluoric acid aqueous solution and an ammonium fluoride aqueous solution are mixed at a ratio of 1: 6) to form the second nozzle hole 11b. The silicon oxide film 101 is removed (FIG. 5C).

(D) The photoresist film 102 is removed by washing with sulfuric acid or the like (FIG. 5D).

(E) Then, a photoresist film 110a is formed on the bonding surface 100b of the silicon substrate 100, a portion of the photoresist film 110a that becomes the first nozzle hole 11a is removed, and pattern formation (patterning) is performed (FIG. 6). (E)).

(F) Then, the silicon substrate 100 in the portion of the first nozzle hole 11a is etched by a predetermined amount by dry etching.

(G) Then, the photoresist film 110a is removed by washing with sulfuric acid or the like (FIG. 6G).

(H) Next, dry etching is performed to form a recess (hole) having a depth of about 40 μm using the silicon oxide film 101 formed other than the second nozzle hole 11b as a mask (FIG. 7 (h)). . The type of dry etching or the like is not particularly limited. For example, dry etching by ICP (Inductively Coupled Plasma) discharge may be performed. In this case, the etching is alternately repeated in the depth direction with SF ₆ (sulfur hexafluoride) while protecting the side wall surface with, for example, fluorine-based C ₄ F ₈ (octafluorocyclobutane) as a gas used for etching. Then, dry etching is performed.

(I) Next, the entire silicon oxide film 101 left by wet etching of the entire surface with a hydrofluoric acid aqueous solution or the like is removed (FIG. 7I).

(K) A silicon oxide film (SiO ₂ ) is applied to the bonding surface 100b of the silicon substrate 100 and the droplet discharge surface 100a serving as the ink discharge side surface and the inner walls of the first nozzle hole 11a and the second nozzle hole 11b. A first droplet protective film 12 is formed (FIG. 7 (k)). Here, for example, a 0.1 μm film is formed on the entire surface by using a dry thermal oxidation method in which the silicon substrate 100 is exposed to an oxygen atmosphere of about 1000 ° C. for 2 hours.

(L) Next, the bonding surface 100b of the silicon substrate 100 and the support substrate 120 are bonded and fixed with, for example, a double-sided tape 50 (FIG. 8L). From FIG. 8 (l) to FIG. 9 (r), FIG. 7 (k) is shown upside down.
The double-sided tape 50 is not particularly limited. For example, the adhesive strength (adhesive strength) may be reduced by heat, ultraviolet rays, or the like, and the tape may have a self-peeling layer. In the present embodiment, for example, a double-sided tape 50 having UV curable adhesive layers 51 whose adhesive strength is weakened by ultraviolet irradiation is provided on both sides. Here, if bubbles are included in the adhesive interface, the plate thickness may vary during polishing. Therefore, the UV curable adhesive layer 51 of the double-sided tape 50 bonded to the support substrate 120 and the support substrate 120 face each other. Bonding is performed in a vacuum so that bubbles are not left at the bonding interface so that clean bonding is performed.

(M) The silicon substrate 100 is ground by a back grinder (not shown) from the droplet discharge surface 100a of the silicon substrate 100 until the thickness becomes slightly larger than a desired plate thickness. Here, grinding is performed until a predetermined plate thickness is obtained. Further, polishing is performed to a desired plate thickness by a polisher and a CMP (Chemical Mechanical Polishing) apparatus (FIG. 8 (m)). Thereby, the tip of the first nozzle hole 11a is opened. That is, the nozzle hole 11 penetrating the silicon substrate 100 is formed.

(N) A metal or silicon first mask member 150 is placed on a portion of the droplet discharge surface 100a of the thinned silicon substrate 100 where the conductive terminal 13 is to be formed. Then, a silicon polymer film serving as the second droplet protective film 14 is formed to a thickness of 0.2 to 2 μm by plasma CVD (Chemical Vapor Deposition) of a siloxane raw material. Further, the silicon polymer film is dehydrated and condensed by irradiating UV light in the air, and the surface of the _second droplet protective film 14 is changed to SiO ₂ . Here, in order to secure the bonding state with the water repellent film 15, a silicon polymer film is formed by plasma CVD of a siloxane raw material, but the present invention is not limited to this, and the second droplet protective film 14 (SiO Any film can be used as long as it can form _two films. For example, the SiO ₂ film may be formed by plasma CVD using TEOS (Tetraethylorthosilicate Tetraethoxysilane) as a raw material.

(O) as shown in FIG. 9 (o), when removing the first mask member 150, portions mounted with the first mask member 150, a second droplet protective film 14 (SiO ₂ film) As a result, the silicon substrate 100 is opened and exposed.

(P) Next, the second mask member 151 having an opening in which the conductive terminal 13 is formed is placed on the droplet discharge surface 100a side of the silicon substrate 100, and the silicon substrate of the droplet discharge surface 100a is placed on the silicon substrate. A conductive terminal 13 is formed in a portion where 100 is opened. In the present embodiment, the conductive terminal 13 having a thickness of 0.2 μm is formed by sputtering (FIG. 9P). Here, although the conductive terminal 13 (a refractory metal silicide film) is formed by sputtering, the temperature at which the UV curable adhesive layer 51 is not deteriorated and the adhesion to the silicon substrate 100 can be secured. The sputtering method is not limited as long as the film can be formed at a temperature of about 100 ° C. or less. Further, for example, an ITO film or the like can be used as the material of the conductive terminal 13.

(Q) As shown in FIG. 9 (q), when the second mask member 151 is removed, the conductive terminal 13 is formed in the opening portion of the second mask member 150 (the opening portion of the silicon substrate 100). Will be. Thus, on the droplet discharge surface 100a of the silicon substrate 100, the second droplet protective film 14 and the conductive terminal 13 are formed with substantially the same film thickness.

(R) Next, a water repellent treatment is performed on the surface of the droplet discharge surface 100a on which the conductive terminal 13 and the second droplet protective film 14 are formed. The water repellent film 15 formed by this water repellent treatment has a lower withstand voltage than the second droplet protective film 14. In the present embodiment, for example, a water repellent material containing fluorine (F) atoms (for example, a silane coupling material) is applied to the droplet discharge surface 100a by dip coating or vapor deposition to form the water repellent film 15 (FIG. 9). (R)). By this water repellent treatment, the water repellent film 15 is also formed on the inner wall of the nozzle hole 11 which does not need to be formed.

(S) A protective film 60 is affixed to the droplet discharge surface 100a of the silicon substrate 100 (FIG. 10 (s)). From FIG. 10 (s) to (v), FIG. 9 (r) is shown upside down.

(T) Next, ultraviolet light is irradiated from the support substrate 120 side (FIG. 10 (t)).

(U) Then, the UV curable adhesive layer 51 of the double-sided tape 50 is cured to separate the support substrate 120 and the silicon substrate 100 (FIG. 10 (u)).

(V) by Ar plasma treatment or 0 ₂ plasma treatment, the bonding surface 100b of the silicon substrate 100, a water-repellent film 15 which is extra formed on the inner wall of the nozzle hole 11 is removed, or the no membrane water repellent To do. That is, the water repellent film 15 is made hydrophilic by eliminating the fluorine atoms. In this embodiment, Ar plasma treatment is performed (FIG. 10 (v)).

(W) Next, the bonding surface 100b side of the silicon substrate 100 is suction-fixed to the suction jig 70, and the protective film 60 attached to the droplet discharge surface 100a is peeled off (FIG. 11 (w)). FIGS. 11 (w) and 11 (x) are diagrams in which the top and bottom of FIG. 10 (v) are reversed.
Then, the suction fixing of the suction jig 70 is released, and cutting (dicing) or the like is performed using a cutter or the like, so that the nozzle substrate 1 is divided into individual pieces (chips).

In this way, a nozzle substrate is produced in which the conductive terminal 13 having a lower withstand voltage against static electricity than the second droplet protective film 14 is formed on the droplet discharge surface 100a side (FIG. 11 (x)).
Through the above steps, the nozzle substrate 1 is manufactured from the silicon substrate 100.

According to the method for manufacturing the nozzle substrate 1 according to the present embodiment, the second droplet protective film 14 and the conductive terminal 13 can be formed on the droplet discharge surface 100 a of the silicon substrate 100. For this reason, static electricity charged on the substrate can be discharged to the conductive terminal 13, and the occurrence of peeling or breakage of the second droplet protective film 14 can be suppressed. Further, by suppressing the occurrence of peeling or breakage of the second droplet protective film 14, it is possible to prevent the silicon substrate 100 from being eroded by the droplets, and to improve the durability of the nozzle substrate 1 against the droplets. Can do.
In addition, since the conductive terminal 13 is formed using the first mask member 150 and the second mask member 151, the manufacturing process is simplified and the manufacturing cost is reduced as compared with the case where the photolithography method is used. Can be achieved.

  Further, since the water-repellent film 15 is formed on the second droplet protective film 14 and the conductive terminal 13, the durability of the nozzle substrate 1 against the droplets can be further improved. Further, since the water repellent film 15 having a lower withstand voltage than the second droplet protective film is formed, static electricity charged on the printed material can be discharged to the conductive terminal 13.

  Further, since the conductive terminal 13 is formed by sputtering, the conductive terminal 13 can be formed at a relatively low temperature step in the film forming step. Accordingly, when the nozzle substrate 1 is manufactured, a film can be formed in a state where the support substrate 120 such as a resin is adhered to the nozzle substrate 1, handling property and processing efficiency are improved, and cost can be reduced.

  Further, since the second droplet protective film 14 is formed by plasma CVD, the second droplet protective film 14 can be formed at a relatively low temperature step in the film forming step. Accordingly, when the nozzle substrate 1 is manufactured, a film can be formed in a state where the support substrate 120 such as a resin is adhered to the nozzle substrate 1, handling property and processing efficiency are improved, and cost can be reduced.

  Further, since the support substrate 120 is bonded to the bonding surface 100b via the double-sided tape 50, the silicon substrate 100 is made thinner than the droplet discharge surface 100a and the nozzle hole 11 is opened. The silicon substrate 100 is not cracked or chipped, handling is easy, and the yield is improved.

  Next, a method for manufacturing the cavity substrate 2 and the electrode substrate 3 will be described.

12 and 13 are views showing a manufacturing process of the droplet discharge head.
Here, a method of manufacturing the cavity substrate 2 from the silicon substrate 200 after bonding a single crystal silicon substrate (hereinafter referred to as a silicon substrate) 200 to the electrode substrate 3 will be described with reference to FIGS. In practice, a plurality of droplet discharge head members are simultaneously formed from a silicon wafer, but only a part thereof is shown in FIGS.

(A) First, a recess 32 is formed in a glass substrate 300 made of borosilicate glass by etching with hydrofluoric acid using, for example, a gold / chromium etching mask. Note that the recess 32 has a groove shape slightly larger than the shape of the individual electrode 31, and a plurality of the recesses 32 are formed for each individual electrode 31. Then, an individual electrode 31 made of ITO (Indium Tin Oxide) is formed inside the recess 32 by sputtering, for example. Thereafter, a hole 33a to be the ink supply port 33 is formed by a drill or the like, thereby producing the electrode substrate 3 (FIG. 12A).

(B) After both surfaces of the silicon substrate 200 are mirror-polished, a silicon oxide film (insulating film) 25 made of TEOS is formed on one surface of the silicon substrate 200 by plasma CVD (Chemical Vapor Deposition) (FIG. 12B). ). In addition, before forming the silicon substrate 200, a boron doped layer for forming the thickness of the diaphragm 22 with high accuracy may be formed by using an etching stop technique. Etching stop is defined as a state in which bubbles generated from the etching surface are stopped, and in actual wet etching, it is determined that the etching is stopped when the generation of bubbles is stopped.

(C) The silicon substrate 200 and the electrode substrate 3 manufactured as shown in FIG. 12A are heated to, for example, 360 ° C., and the silicon substrate 200 is connected to the anode, and the electrode substrate 3 is connected to the cathode. A voltage of about 800 V is applied, and a voltage of about 800 V is applied to join by anodic bonding (FIG. 12C).

(D) After the silicon substrate 200 and the electrode substrate 3 are anodically bonded, the bonded silicon substrate 200 is etched with an aqueous potassium hydroxide solution or the like to thin the silicon substrate 200 (FIG. 12D).

(E) A TEOS film 260 is formed on the entire upper surface of the silicon substrate 200 (the surface opposite to the surface to which the electrode substrate 3 is bonded) by plasma CVD. The TEOS film 260 is patterned with a resist for forming a discharge recess 210 to be the discharge chamber 21, an orifice recess 240 to be the orifice 24, and a reservoir recess 230 to be the reservoir 23. Etch away.
Thereafter, the silicon substrate 200 is etched with a potassium hydroxide aqueous solution or the like to form a discharge recess 210 serving as the discharge chamber 21, an orifice recess 240 serving as the orifice 24, and a reservoir recess 230 serving as the reservoir 23 (FIG. 13E). ). At this time, the portion that becomes the electrode lead-out portion 36 for wiring is also etched and thinned. In the wet etching step, for example, a 35% by weight potassium hydroxide aqueous solution can be used first, and then a 3% by weight potassium hydroxide aqueous solution can be used. Thereby, surface roughness of the diaphragm 22 can be suppressed.

(F) After the etching of the silicon substrate 200 is completed, etching is performed with a hydrofluoric acid aqueous solution, and the TEOS film 260 formed on the upper surface of the silicon substrate 200 is removed as shown in FIG. f)).

(G) A TEOS film (insulating film) 26 is formed by plasma CVD on the surface of the silicon substrate 200 on which the discharge recesses 210 and the like that will become the discharge chambers 21 are formed (FIG. 13G).

(H) The electrode extraction unit 36 is opened by RIE (Reactive Ion Etching) or the like. Further, laser processing is performed on the hole portion that becomes the ink supply port 33 of the electrode substrate 3 to penetrate the bottom of the reservoir recess 230 that becomes the reservoir 23 of the silicon substrate 200, thereby forming the ink supply port 33. Further, the open end portion of the gap 34 between the diaphragm 22 and the individual electrode 31 is filled with a sealing material 35 such as epoxy resin and sealed. Further, the common electrode 27 is formed on the end portion of the silicon substrate 200 by sputtering (FIG. 13H).

As described above, the cavity substrate 2 is manufactured from the silicon substrate 200 bonded to the electrode substrate 3.
Finally, the ink jet head 10 shown in FIG. 2 is completed by bonding the nozzle substrate 1 manufactured as described above to the cavity substrate 2 by bonding or the like.

  According to the method for manufacturing the inkjet head 10 according to the present embodiment, the cavity substrate 2 is produced from the silicon substrate 200 bonded to the electrode substrate 3 produced in advance, so that the silicon substrate 200 is supported by the electrode substrate 3. Thus, even if the silicon substrate 200 is thinned, it is not cracked or chipped, and handling becomes easy. Accordingly, the yield is improved as compared with the case where the cavity substrate 2 is manufactured alone.

Embodiment 2. FIG.
In the first embodiment, the case where the conductive terminal 13 made of a conductive material is formed on the droplet discharge surface 100a of the silicon substrate 100 has been described. However, in the present embodiment, the droplet of the silicon substrate 100 is formed. A mode in which a portion of the ejection surface 100a where the second droplet protective film 14 is not formed is used as a terminal portion will be described.

FIG. 14 is an enlarged cross-sectional view of a nozzle substrate according to Embodiment 2 of the present invention.
Hereinafter, the configuration of the nozzle substrate 1 in the second embodiment will be described. In addition, the same code | symbol is attached | subjected about the structure same as the said Embodiment 1. FIG.

In the nozzle substrate 1 according to the second embodiment, the second droplet protective film 14 made of, for example, SiO ₂ has a film thickness of about 0.2 except for a part on the droplet discharge surface 100a of the silicon substrate 100. It is formed with ˜2 μm. A water repellent film 15 having a lower withstand voltage than that of the second droplet protective film 14 is formed on the entire surface of the droplet discharge surface 100a as in the first embodiment. That is, the conductive terminal 13 made of the metal material described in the first embodiment is not formed.
A portion of the droplet discharge surface 100a of the silicon substrate 100 where the second droplet protective film 14 is not formed is defined as a terminal portion 13b. That is, since the water-repellent film 15 has a lower withstand voltage than the second droplet protective film 14, the insulation of the terminal portion 13b, which is a portion on the droplet discharge surface 100a where the second droplet protective film 14 is not formed. The breakdown voltage is lower than the portion where the second droplet protective film 14 is formed.

  Even in such a configuration, similarly to the first embodiment, it is possible to easily discharge the static electricity charged on the printed material in the terminal portion 13b, and discharge to the second droplet protective film 14 is possible. Can be suppressed.

  Further, since the water-repellent film 15 is formed on the droplet discharge surface 100a, the portion of the droplet discharge surface 100a where the second droplet protective film is not formed is prevented from being eroded by the droplets of the silicon substrate 100. And the durability of the nozzle substrate 1 against droplets can be improved.

  Next, a method for manufacturing the nozzle substrate 1 in the present embodiment configured as described above will be described focusing on differences from the first embodiment. The manufacturing method of the cavity substrate 2 and the electrode substrate 3 is the same as that in the first embodiment.

  The manufacturing steps (a) to (o) are performed in the same manner as in the first embodiment, the second droplet protective film 14 is formed except for a part of the droplet discharge surface 100a of the silicon substrate 100, and the terminal portion 13b. The part of the silicon substrate 100 to be exposed is exposed. Then, in the second embodiment, after the manufacturing process (o), the manufacturing process (r) is performed to form the water repellent film 15 on the entire surface on the droplet discharge surface 100a side. Thereafter, the manufacturing steps (s) to (x) are performed in the same manner as in the first embodiment to create the nozzle substrate 1. That is, in the second embodiment, the manufacturing steps (p) and (q) are omitted.

  As described above, according to the method of manufacturing the nozzle substrate 1 according to the present embodiment, the portion of the droplet discharge surface 100a of the silicon substrate 100 where the second droplet protective film 14 is not formed is the terminal portion 13b. The manufacturing process for forming the conductive terminal 13 can be omitted, the terminal portion 13b can be easily formed, and the manufacturing cost and the like can be reduced.

Embodiment 3 FIG.
15 is a top view of the nozzle substrate according to the third embodiment of the present invention.
In the first embodiment (FIG. 4), the case where the conductive terminal 13 is provided only on one side (right side) of the nozzle hole row is shown, but not limited thereto, the conductive terminal 13 or the terminal portion 13b is For example, as shown in FIG. 15A, it may be further provided on the other side (left side) according to the conveyance direction of the substrate. Further, for example, as shown in FIG. 15B, it may be provided so as to surround the nozzle hole row.

  With such a configuration, static electricity charged on the printed material can be discharged to the conductive terminal 13 or the terminal portion 13b before the printed material is conveyed to the vicinity of the nozzle. For this reason, peeling or breakage of the droplet protective film formed near the nozzle hole and the nozzle hole can be suppressed.

Embodiment 4 FIG.
FIG. 16 is an external view of a droplet discharge apparatus using the droplet discharge head manufactured in the above embodiment. FIG. 17 is a diagram illustrating an example of main constituent means of the droplet discharge device.
An ink jet recording apparatus 400 as a liquid droplet ejection apparatus in FIGS. 16 and 17 is an ink jet printer on which the ink jet head 10 according to any one of the first to third embodiments is mounted.

  In FIG. 17, an ink jet recording apparatus 400 is mainly composed of a drum 401 on which a print paper 410 as a printing object is supported, and an ink jet head 10 as a liquid droplet discharge head for discharging ink onto the print paper 410 and performing recording. Composed. Although not shown, there is an ink supply unit for supplying ink to the inkjet head 10. The print paper 410 is held by being pressed against the drum 401 by a paper press roller 403 provided parallel to the axial direction of the drum 401. A feed screw 404 is provided parallel to the axial direction of the drum 401, and the inkjet head 10 is held. The inkjet head 10 is moved in the axial direction of the drum 401 by the rotation of the feed screw 404. In addition, the inkjet head 10 is mounted such that the conductive terminals 13 of the nozzle substrate 1 are arranged on the upstream side in the conveyance direction (movement direction) of the print paper 410 from the nozzle holes 11.

  On the other hand, the drum 401 is rotationally driven by a motor 406 via a belt 405 or the like. Further, the print control unit 407 drives the feed screw 404 and the motor 406 based on the print data and the control signal, and although not shown here, drives the oscillation drive circuit to vibrate the diaphragm 22, Printing is performed on the print paper 410 while controlling.

As described above, in the present embodiment, since the inkjet head 10 according to any of the first to third embodiments is mounted, the static electricity charged on the print paper 410 is converted into the conductivity formed on the nozzle substrate 1. It is possible to discharge to the terminal 13, and it is possible to suppress the occurrence of peeling or breakage of the second droplet protective film 14 of the nozzle substrate 1 and to improve the durability of the nozzle substrate 1 against the droplet. A discharge device can be obtained.
In the nozzle head 10, since the conductive terminal 13 is arranged on the upstream side in the transport direction of the print paper 410 from the nozzle hole 11, before the print paper 410 is transported to the vicinity of the nozzle hole 11, The charged static electricity can be discharged to the conductive terminal 13. For this reason, generation | occurrence | production of peeling or damage of the 2nd droplet protective film 14 formed in the nozzle hole 11 and the nozzle hole 11 vicinity can be suppressed.

  In the fourth embodiment, droplets are ejected as ink onto the print paper 410, but the liquid ejected from the droplet ejection head is not limited to ink. For example, in an application to be discharged onto a substrate to be a color filter, a liquid containing a pigment for a color filter, an application to be discharged to a display substrate such as an OLED, an application to be wired on a substrate, a liquid containing a compound to be a light emitting element In this case, for example, a liquid containing a conductive metal may be discharged from a droplet discharge head provided in each device. In addition, when the droplet discharge head is used as a dispenser and used for discharging onto a substrate that is a microarray of biomolecules, DNA (Deoxyribo Nucleic Acids: deoxyribonucleic acid), other nucleic acids (for example, Ribo Nucleic Acid: ribonucleic acid, Peptide (Nucleic Acids: peptide nucleic acids, etc.) A liquid containing a probe such as a protein may be discharged. In addition, it can also be used for discharging dyes such as cloth. In particular, it is effective to be used for a droplet discharge device for printing on hair, chemical fiber, etc., which is easily charged with static electricity.

1 is an exploded perspective view showing a schematic configuration of a droplet discharge head according to Embodiment 1 of the present invention. FIG. 2 is a partial cross-sectional view of a droplet discharge head showing a schematic configuration of a right half of FIG. 1 in an assembled state. It is an expanded sectional view of the nozzle hole part of FIG. It is a top view of the nozzle substrate of FIG. It is a fragmentary sectional view showing a manufacturing process of a nozzle substrate. FIG. 6 is a partial cross-sectional view illustrating a nozzle substrate manufacturing process following FIG. 5. FIG. 7 is a partial cross-sectional view illustrating a nozzle substrate manufacturing process following FIG. 6. FIG. 8 is a partial cross-sectional view illustrating a nozzle substrate manufacturing process following FIG. 7. FIG. 9 is a partial cross-sectional view showing the nozzle substrate manufacturing process following FIG. 8. FIG. 10 is a partial cross-sectional view illustrating the nozzle substrate manufacturing process following FIG. 9. FIG. 11 is a partial cross-sectional view illustrating a nozzle substrate manufacturing process following FIG. 10. It is a fragmentary sectional view which shows the process of manufacturing a cavity substrate from the manufacture of an electrode substrate, and the silicon substrate joined on the electrode substrate. FIG. 13 is a partial cross-sectional view showing a manufacturing step of the cavity substrate that follows FIG. 12. It is an expanded sectional view of the nozzle substrate which concerns on Embodiment 2 of this invention. It is a top view of the nozzle substrate which concerns on Embodiment 3 of this invention. It is an external view of a droplet discharge device using a droplet discharge head. It is a figure showing an example of the main structural means of a droplet discharge apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Nozzle substrate, 1a Droplet discharge surface, 1b Bonding surface, 2 Cavity substrate, 3 Electrode substrate, 4 Electrostatic actuator, 5 Driving means, 10 Inkjet head, 11 Nozzle hole, 11a 1st nozzle hole, 11b 2nd nozzle hole , 12 First droplet protective film, 13 Conductive terminal, 13b Terminal portion, 14 Second droplet protective film, 15 Water repellent film, 21 Discharge chamber, 22 Vibration plate, 23 Reservoir, 24 Orifice, 25 Insulating film , 26 Ink-resistant protective film, 27 Common electrode, 28 Grounding location, 31 Individual electrode, 31a Lead portion, 31b Terminal portion, 32 Recessed portion, 33 Ink supply port, 33a Hole portion, 34 Gap, 35 Sealing material, 36 Extraction of electrode Part, 50 double-sided tape, 51 curable adhesive layer, 60 protective film, 70 suction jig, 100 silicon substrate, 100a droplet Exit surface, 100b bonding surface, 101 silicon oxide film, 102 photoresist film, 110a photoresist film, 120 support substrate, 150 first mask member, 151 second mask member, 200 silicon substrate, 210 discharge recess, 230 reservoir recess , 240 orifice recess, 260 TEOS film, 300 glass substrate, 400 inkjet recording device, 401 drum, 403 paper pressure roller, 404 screw, 405 belt, 406 motor, 407 print control means, 410 print paper.

Claims (18)

A nozzle substrate having a nozzle hole for discharging a droplet through a silicon substrate,
A droplet protective film formed on the droplet ejection surface of the silicon substrate;
A nozzle substrate comprising: a terminal portion formed on a droplet discharge surface side and having a lower withstand voltage than the droplet protective film.   The nozzle substrate according to claim 1, wherein the terminal portion is formed between the nozzle hole and an end portion of the nozzle substrate. A nozzle hole row in which a plurality of the nozzle holes are arranged is formed,
The nozzle substrate according to claim 1, wherein the terminal portion is formed wide in the width direction of the nozzle hole row.   4. The nozzle substrate according to claim 1, wherein the terminal portion is made of a material capable of ohmic contact with the silicon substrate and is electrically connected to the silicon substrate.   5. The nozzle substrate according to claim 1, wherein the terminal portion includes a refractory metal silicide film or an ITO film as a main component.   The nozzle substrate according to any one of claims 1 to 3, wherein a portion of the droplet discharge surface of the silicon substrate where the droplet protective film is not formed is used as the terminal portion.   The nozzle substrate according to claim 1, further comprising a coating film having a dielectric strength lower than that of the droplet protective film on at least a surface of the terminal portion.   A liquid droplet ejection head comprising the nozzle substrate according to claim 1.   9. The droplet discharge head according to claim 8, wherein the terminal portion is grounded to a casing in which the droplet discharge head is stored.   10. A droplet discharge apparatus comprising the droplet discharge head according to claim 8 or 9.   11. The droplet discharge device according to claim 10, wherein the droplet discharge head is mounted such that the terminal portion is disposed upstream of the nozzle hole in the conveyance direction of the substrate. Forming a nozzle hole through the silicon substrate;
A step of covering a portion of the droplet discharge surface of the silicon substrate where the terminal portion is formed with a first mask member, and forming a droplet protective film on the droplet discharge surface;
Removing the first mask member;
A step of covering a portion of the droplet discharge surface of the silicon substrate other than a portion for forming the terminal portion with a second mask member, and forming a terminal portion having a lower withstand voltage than the droplet protective film;
And a step of removing the second mask member.   13. The nozzle according to claim 12, further comprising a step of forming a coating film having a lower withstand voltage than the droplet protective film on the droplet protective film and the terminal portion on the droplet discharge surface. A method for manufacturing a substrate.   14. The method of manufacturing a nozzle substrate according to claim 12, wherein the terminal portion is formed by sputtering. Forming a nozzle hole through the silicon substrate;
A step of covering a portion of the droplet discharge surface of the silicon substrate where the terminal portion is formed with a first mask member, and forming a droplet protective film on the droplet discharge surface;
Removing the first mask member;
Forming a coating film having a lower withstand voltage than the droplet protective film on the droplet discharge surface, and using the portion of the droplet discharge surface where the droplet protective film is not formed as the terminal portion. A method for manufacturing a nozzle substrate.   The method of manufacturing a nozzle substrate according to claim 12, wherein the droplet protective film is formed by plasma CVD.   A method for manufacturing a droplet discharge head, wherein the method for manufacturing a nozzle substrate according to any one of claims 12 to 16 is applied to manufacture a droplet discharge head.   A method for manufacturing a droplet discharge device, wherein the droplet discharge device is manufactured by applying the method for manufacturing a droplet discharge head according to claim 17.

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