JP2008273079A - Manufacturing method for nozzle substrate, manufacturing method for liquid droplet discharge head and manufacturing method for liquid droplet discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method or the like for a nozzle substrate in which a water repellent film and a hydrophilic film can be uniformly and simply formed to a liquid droplet discharge surface and a channel of liquid droplets, respectively. <P>SOLUTION: The manufacturing method for the nozzle substrate 1 which has nozzle holes 11 for discharging the liquid droplets, and in which the liquid droplet discharge surface 1b of the nozzle hole 11 is water repellent and an inner surface 1c of the nozzle hole 11 is hydrophilic includes the process of forming the water repellent film 12 to at least a liquid droplet discharge surface 100b of a nozzle base material 100, for example, only the liquid droplet discharge surface 100b, or to the whole surface; the process of further forming the hydrophilic film 13 to at least the liquid droplet discharge surface 100b and a nozzle hole inner surface 100c of the nozzle base material 100 formed with the water repellent film 12, for example, to the whole surface; and the process of removing the hydrophilic film 13 formed to the liquid droplet discharge surface 100b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a nozzle substrate manufacturing method, a droplet discharge head manufacturing method, and a droplet discharge apparatus manufacturing method.

As a droplet discharge head for discharging droplets, for example, an inkjet head mounted on an inkjet recording apparatus is known. The ink-jet head has many advantages such as extremely low noise during recording, high-speed printing, and use of inexpensive plain paper with a high degree of ink freedom. Among them, a so-called ink-on-demand system that discharges ink droplets only when recording is necessary does not require collection of ink droplets that are not necessary for recording, and is now mainstream. Ink-on-demand ink jet heads include a method using an electrostatic force as a driving means and a method using a piezoelectric vibrator, a heating element, or the like as a method for ejecting ink.

Ink jet heads generally include a nozzle substrate in which a plurality of nozzle holes for discharging ink droplets are formed, and an ink such as a discharge chamber and a reservoir that are bonded to the nozzle substrate and communicate with the nozzle holes. And a cavity substrate on which a flow path is formed, and an ink droplet is ejected from a selected nozzle hole by applying pressure to the ejection chamber by a driving unit.

In recent years, there has been an increasing demand for ink jet heads with higher quality such as printing and image quality, and higher density and improved ejection performance have been demanded. For this reason, various devices and proposals have been made for the nozzle portion of the inkjet head.

Ink jet heads are subjected to ink repellent treatment on the ink ejection surface to prevent ink from adhering to the ink ejection surface and smudges, and the inside of the nozzle holes is subjected to parent ink treatment to stabilize the meniscus.

As a method for manufacturing a nozzle substrate having nozzle holes, a water and oil repellent material is applied to the nozzle substrate,
Silicone rubber is affixed to the water and oil repellent film on the nozzle substrate surface and exposed to an oxygen plasma environment.
There has been a method in which the water / oil repellent film inside the nozzle hole and the back side of the nozzle substrate is removed to make it hydrophilic / lipophilic (for example, see Patent Document 1).

In addition, a funnel-shaped nozzle hole with a cylindrical thin diameter part at the tip is opened in the nozzle substrate, the nozzle hole is filled with resin, and an ink-repellent film is formed on the surface of the nozzle substrate by electrodeposition coating and plating However, there has been a method of removing the resin inside the nozzle hole (see, for example, Patent Document 2).

In addition, a hole penetrating both surfaces with a diameter larger than the nozzle hole was formed, a lyophilic film was formed so as to close the hole, and the lyophilic film formed on the discharge surface was removed by polishing to form a liquid repellent film. Later, there was a method of opening a nozzle hole with a laser, a micro drill, ashing, or the like (for example, see Patent Document 3).

Japanese Patent Laid-Open No. 9-267478 (page 2 to page 3, FIG. 2) JP 2001-18398 A (page 3 to page 4, FIG. 2) JP 2006-326873 A (pages 8-9, FIG. 5)

In the technique described in Patent Document 1, there is a case where the water / oil repellent film removed by plasma is reattached inside the nozzle hole and cannot be uniformly formed.
In the technique described in Patent Document 2, the shape of the nozzle hole is limited to a funnel shape having a small diameter portion at the tip, and the ink film is resistant to using an organic solvent to remove the resin filled in the nozzle hole. Limited to chemicals.
In the technique described in Patent Document 3, the nozzle hole has to be processed twice, the process becomes long, and the nozzle hole is limited to a straight shape.

The present invention has been made to solve the above-described problems, and a nozzle substrate capable of forming a water-repellent film on a droplet discharge surface and a hydrophilic film on a droplet channel uniformly and easily. It is an object of the present invention to provide a manufacturing method, a manufacturing method of a droplet discharge head, and a manufacturing method of a droplet discharge device.

A method for manufacturing a nozzle substrate according to the present invention includes a nozzle substrate having a nozzle hole for discharging a droplet, the droplet discharge surface of the nozzle hole is water repellent, and the inner surface of the nozzle hole is hydrophilic. A method for producing a water repellent film on at least a droplet discharge surface of the nozzle substrate; and
A step of further forming a hydrophilic film on at least a droplet discharge surface and an inner surface of the nozzle hole of the nozzle substrate on which the water repellent film is formed; and a step of removing the hydrophilic film formed on the droplet discharge surface. It is a waste.

When the water repellent film and the hydrophilic film are formed in the nozzle holes, plasma treatment with argon, oxygen, or the like is unnecessary, so that the water repellent film and the hydrophilic film can be formed uniformly. In addition, since the inner wall of the nozzle hole is made uniform hydrophilic, the droplet discharge characteristics are stabilized, ink flying bending is suppressed, and the quality is improved. Further, when the nozzle hole is processed, it is not necessary to fill a protective material or reprocess the nozzle hole, and the process is simplified. Moreover, when forming a nozzle hole, arbitrary shapes can be selected.

Further, in the method for manufacturing a nozzle substrate according to the present invention, the step of forming the water repellent film on at least the droplet discharge surface of the nozzle base material forms the water repellent film only on the droplet discharge surface of the nozzle base material. It is a process to do.
A water repellent film can be formed uniformly by a simplified process.

In the method for manufacturing a nozzle substrate according to the present invention, the step of forming a water repellent film on at least a droplet discharge surface of the nozzle base includes the water repellent on the droplet discharge surface and the nozzle hole inner surface of the nozzle base. This is a step of forming a film.
A water repellent film can be formed uniformly by a simplified process.

Further, in the method for manufacturing a nozzle substrate according to the present invention, the step of forming the water repellent film on at least the droplet discharge surface of the nozzle base material is the step of forming the water repellent film on the entire surface of the nozzle base material. is there.
A water repellent film can be formed uniformly by a simplified process.

Further, in the method for manufacturing a nozzle substrate according to the present invention, the step of further forming a hydrophilic film on at least a droplet discharge surface and an inner surface of the nozzle hole of the nozzle base material on which the water-repellent film is formed includes: It is a step of further forming the hydrophilic film on the surface.
A hydrophilic film can be formed uniformly by a simplified process.

In the method for producing a nozzle substrate according to the present invention, the hydrophilic film formed on the droplet discharge surface is removed by polishing.
A uniform water repellent film can be easily exposed.

In the method for manufacturing a nozzle substrate according to the present invention, the water-repellent film and the hydrophilic film are formed by dip coating.
The water repellent film and the hydrophilic film can be formed reliably and accurately.

In the method for producing a nozzle substrate according to the present invention, the water-repellent film is made of a silane compound containing a fluoroalkyl group.
With the water-repellent film, it is possible to reliably prevent the droplets from adhering to the droplet discharge surface and contamination.

Further, in the method for producing a nozzle substrate according to the present invention, the water repellent film is composed of trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, and tridecafluorooctyltrimethoxysilane. It consists of either.
The above-described water-repellent film can surely prevent the droplets from adhering to the droplet discharge surface and dirt.

In the method for producing a nozzle substrate according to the present invention, the hydrophilic film is a silane coupling agent represented by XSi (OR) ₃ , wherein X is an amino group, and OR is an ethoxy group or methoxy group. It consists of a hydrolyzable functional group consisting of a group.
The inner surface of the nozzle hole is made uniform by the hydrophilic film, and the meniscus inside the nozzle hole is stabilized.

Further, in the method for producing a nozzle substrate according to the present invention, the hydrophilic film has γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, and γ- (2 -Aminoethyl) consisting of any of aminopropyltriethoxysilane.
The inner surface of the nozzle hole is made uniform by the hydrophilic film, and the meniscus inside the nozzle hole is stabilized.

In the nozzle substrate manufacturing method according to the present invention, the nozzle base material is made of silicon, stainless steel, or nickel.
A nozzle hole can be easily formed by a method suitable for each of these substrates.

Moreover, the manufacturing method of the nozzle board | substrate concerning this invention forms the said nozzle hole by etching from both surfaces, after thinning the said nozzle base material which consists of silicon | silicone.
A nozzle hole can be easily formed by a method suitable for a silicon substrate.

Moreover, the manufacturing method of the nozzle board | substrate concerning this invention forms the said nozzle hole by perforation in the said nozzle base material consisting of stainless steel or nickel.
A nozzle hole can be easily formed by a method suitable for a stainless steel substrate or a nickel substrate.

A manufacturing method of a droplet discharge head according to the present invention has a nozzle hole for discharging a droplet,
A method of manufacturing a droplet discharge head using a method of manufacturing a nozzle substrate in which the droplet discharge surface of the nozzle hole is water-repellent and the inner surface of the nozzle hole is hydrophilic, wherein at least the liquid of the nozzle substrate Forming a water-repellent film on the droplet discharge surface, forming a hydrophilic film on the surface of the nozzle substrate on which the water-repellent film is formed, and removing the hydrophilic film on the droplet discharge surface. A method of manufacturing a nozzle substrate including the above is used.
A droplet discharge head in which droplet discharge is stable and quality is improved can be provided.

The method for manufacturing a droplet discharge device according to the present invention has a nozzle hole for discharging a droplet, the nozzle discharge surface of the nozzle hole is water-repellent, and the inner surface of the nozzle hole is hydrophilic A method for manufacturing a droplet discharge apparatus for manufacturing a droplet discharge head using a substrate manufacturing method, comprising: forming a water repellent film on at least a droplet discharge surface of the nozzle base; and A method of manufacturing a nozzle substrate, comprising: a step of further forming a hydrophilic film on at least a droplet discharge surface and an inner surface of a nozzle hole of the formed nozzle base material; and a step of removing the hydrophilic film formed on the droplet discharge surface. A method for manufacturing a droplet discharge head is used.
A high quality droplet discharge device can be provided.

Embodiment 1 FIG.
1 is an exploded perspective view of a droplet discharge head (inkjet head) according to Embodiment 1 of the present invention, FIG. 2 is a longitudinal sectional view of a main part in a state where FIG. 1 is assembled, and FIG. 3 is a main part of FIG. FIG.
In the figure, an inkjet head 10 includes a nozzle substrate 1 in which a plurality of nozzle holes 11 are provided at predetermined intervals, a cavity substrate 2 in which an ink supply path is provided independently for each nozzle hole 11, and a cavity substrate 2. The electrode substrate 3 provided with the individual electrodes 31 is bonded to the diaphragm 22 and is configured to be bonded.

The nozzle substrate 1 is made of a silicon base material. The nozzle hole 11 for ejecting ink droplets is a nozzle hole portion formed in a two-stage cylindrical shape with different diameters, that is, the ink ejection surface 1b.
The first nozzle hole (a small-diameter hole in the ejection port portion) 11a whose tip is open to the ink discharge surface 1b and the introduction port is located on the joint surface 1a side to be joined to the cavity substrate 2 The portion is composed of a second nozzle hole 11b having a large diameter that opens to the bonding surface 1a (a large-diameter hole in the introduction port portion) 11b, and is provided perpendicular to the substrate surface and coaxially. An ink repellent film (water repellent film) 12 is formed on the ink discharge surface 1b, and a nozzle ink inner wall (inner surface of the nozzle hole) 1c and a bonding surface 1a of the nozzle hole 11 are a hydrophilic ink film (hydrophilic film). 13 is formed.
In this manner, the ink droplet ejection direction is aligned with the central axis direction of the nozzle hole 11 to exhibit stable ink ejection characteristics, thereby eliminating variations in the ink droplet flight direction and eliminating ink droplet scattering. The variation in the discharge amount can be suppressed.

The cavity substrate 2 is made of a silicon base material, and a discharge recess 210, an orifice recess 230, and a reservoir recess 240 are formed. And the orifice recess 230 (
The discharge recess 210 (discharge chamber 21) and the reservoir recess 240 (reservoir 24) communicate with each other through the orifice 23). The reservoir 24 constitutes a common ink chamber common to the discharge chambers 21 and communicates with the discharge chambers 21 via the orifices 23. Reservoir 24
An ink supply hole 25 penetrating an electrode substrate 3 to be described later is formed at the bottom of the ink cartridge, and ink is supplied from an ink cartridge (not shown) through the ink supply hole 25. The bottom wall of the discharge chamber 21 is a diaphragm 22. It should be noted that thermal oxidation or plasma CVD (Chemical Vapor Deposition) is applied to the entire surface of the cavity substrate 2 or at least the surface facing the electrode substrate 3.
An insulating SiO ₂ film 26 is applied. This insulating film 26 prevents dielectric breakdown and short circuit when the inkjet head 10 is driven.

The electrode substrate 3 is made from a glass base material. The electrode substrate 3 is provided with a recess 310 at a position facing each diaphragm 22 of the cavity substrate 2. And each recessed part 31
Within 0, an individual electrode 31 made of ITO (Indium Tin Oxide) is formed by sputtering.
The individual electrode 31 includes a lead portion 31a and a terminal portion 31b connected to a flexible wiring board (not shown). The terminal portion 31b is exposed in the electrode extraction portion 311 in which the end portion of the cavity substrate 2 is opened for wiring. And the terminal part 31b of each individual electrode 31 and the common electrode 2 on the cavity substrate 2 are provided via a drive control circuit 40 such as an IC driver.
7 is connected.

Next, the operation of the inkjet head 10 configured as described above will be described. When the drive control circuit 40 is driven and charges are supplied to the individual electrodes 31 to charge them positively, the diaphragm 22 is charged negatively, and an electrostatic force is generated between the individual electrodes 31 and the diaphragm 22. Due to the electrostatic force, the diaphragm 22 is attracted to the individual electrode 31 and bent. As a result, the volume of the discharge chamber 21 increases. When the supply of the electric charge to the individual electrode 31 is stopped, the diaphragm 22 returns to its original state due to its elastic force, and at this time, the volume of the discharge chamber 21 decreases rapidly, and the discharge chamber 21 is caused by the pressure at that time.
Part of the ink inside is ejected from the nozzle hole 11 as ink droplets. Next, when the vibration plate 22 is similarly displaced, ink is supplied from the reservoir 24 through the orifice 23 into the discharge chamber 21.

About the manufacturing method of the inkjet head 10 comprised as mentioned above, FIGS.
Will be described.
4 is a top view showing the nozzle substrate 1 according to the first embodiment of the present invention, and FIGS. 5 to 7 are cross-sectional views showing the manufacturing process of the nozzle substrate 1 (cross-sectional view taken along line AA in FIG. 4). 8 to 9 are cross-sectional views showing a bonding process between the cavity substrate 2 and the electrode substrate 3, and FIG. 10 manufactures the inkjet head 10 by bonding the nozzle substrate 1 to the bonding substrate between the cavity substrate 2 and the electrode substrate 3. It is sectional drawing which shows the manufacturing process to do.

First, the manufacturing process of the nozzle substrate 1 will be described below with reference to FIGS.
(A) Both surfaces of a (110) plane-oriented silicon substrate are mirror-polished to form a silicon substrate 100 having a predetermined thickness as shown in FIG.

(B) Next, the silicon substrate 100 is heat-treated in an oxygen and water vapor atmosphere, and FIG.
As shown in b), both surfaces of the silicon substrate 100, that is, the bonding surfaces of the silicon substrate 100 (
100a which is a surface to be bonded to the cavity substrate 2 and is also referred to as a large-diameter hole side)
And the first SiO ₂ film 10 on the ink discharge surface (also referred to as a small-diameter hole side surface) 100b.
First and second SiO ₂ films 102 are formed. The first and second SiO ₂ films 101 and 102 are
Used as an etching resistant material.

(C) Next, as shown in FIG. 5C, the second nozzle pattern 104 is formed on the second SiO ₂ film 102 on the ink discharge surface 100b of the silicon substrate 100, and the first Si on the bonding surface 100a.
A first nozzle pattern 103 is formed on the O ₂ film 101 by photoetching using a photoresist and a hydrofluoric acid-based etchant, respectively.

(D) Next, as shown in FIG. 6D, anisotropic dry etching is performed on the ink discharge surface 100b of the silicon base material 100 on which the pattern is formed on the first SiO ₂ film 101, so that the first A portion 110a to be a nozzle is formed.

(E) Next, isotropic dry etching having a certain degree of anisotropy is performed on the bonding surface 100a of the silicon base material 100, and a portion that becomes the second nozzle hole as shown in FIG. 6 (e). 1
10b is formed. In this way, a portion to be a nozzle hole 110 having a two-stage structure is formed.

(F) Next, as shown in FIG. 6F, the first and second SiO ₂ films 101 and 102 formed on both surfaces of the silicon substrate 100 are removed with a hydrofluoric acid-based etching solution. Then, heat treatment is performed in an oxygen atmosphere to form a SiO ₂ film (not shown) on the surface of the silicon substrate 100.

In the above description, the silicon substrate 100 is etched when forming the portion 110 serving as the nozzle hole, but a substrate such as stainless steel or nickel may be used. In this case, the portion that becomes the nozzle hole is not formed by etching, but is formed by perforation. For example, the nozzle hole can be drilled by a punching device having a conical protrusion at the tip of the small diameter portion and having a punch having a large diameter portion and a small diameter portion (not shown).

(G) Thus, as shown in FIG. 7 (g) (an enlarged view of the main part of FIG. 6 (f)), the portion 110 serving as the nozzle hole is located on the ink ejection surface 100b side, and the tip thereof is the ink. Discharge surface 10
A portion 110a to be a first nozzle hole having a small diameter opening at 0b, and a second nozzle having a large diameter at which the introduction port portion is located on the bonding surface 100a side to be bonded to the cavity substrate 2 and opens to the bonding surface 100a. It is comprised from the part 110b used as a hole.

(H) As shown in FIG. 7 (h), a water repellent material containing fluorine atoms is applied to the ink ejection surface 100b.
Is applied by dip coating to form a water repellent film 12. In this case, the water repellent material 12 may be applied not only to the ink ejection surface 100b but also to the nozzle inner surface 100c to form the water repellent film 12.
As the water repellent material, a silane compound containing a fluoroalkyl group, for example, trifluoropropyltrimethoxysilane is used. A water repellent material such as heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, or tridecafluorooctyltrimethoxysilane may be used. Moreover, it is not based on dip coating, but can also be performed by vapor deposition, spray coating, spin coating, or the like.

(I) Next, as shown in FIG. 7 (i), a hydrophilic material is applied by dip coating to the surface of the nozzle substrate 100 including the ink discharge surface 100b, the inner wall surface 100c of the nozzle hole, and the bonding surface 100a. A hydrophilic film 13 is formed. As the hydrophilic material, a silane coupling agent represented by the chemical formula XSi (OR) ₃ , wherein X has an amino group (OR is a hydrolyzable functional group such as an ethoxy group or a methoxy group), for example, γ- (2-aminoethyl) aminopropyltrimethoxysilane is used. A hydrophilic material such as γ- (2-aminoethyl) aminopropylmethyldimethoxysilane or γ- (2-aminoethyl) aminopropyltriethoxysilane may be used.

(J) Finally, as shown in FIG. 7 (j), the hydrophilic film 13 formed on the surface of the water repellent film 12 on the ink ejection surface 100b is removed by polishing, and the water repellent film 12 appears on the surface. Like that.
Thus, the nozzle hole 11 is formed from the portion 110 that becomes the nozzle hole, the portion 110a that becomes the first nozzle hole becomes the first nozzle hole 11a, and the portion 110b that becomes the second nozzle hole becomes the second nozzle hole 11b. It becomes.
Through the above manufacturing process, the nozzle substrate 1 is formed from the silicon base material 100.

Next, the bonding process of the cavity substrate 2 and the electrode substrate 3 will be described with reference to FIGS.
Note that the bonding process of the cavity substrate 2 and the electrode substrate 3 is not limited to that shown in FIGS.
(A) First, as shown in FIG. 8 (a), a glass substrate 300 made of borosilicate glass or the like is etched with hydrofluoric acid using, for example, a gold / chromium etching mask, thereby forming a recess 310. Form. The recess 310 has a groove shape slightly larger than the shape of the individual electrode 31, and a plurality of the recesses 310 are formed.
Then, an electrode 31 made of ITO (Indium Tin Oxide) is formed on the bottom of the recess 310 by sputtering. Thereafter, a hole 25a to be the ink supply hole 25 is formed by a drill or the like.

(B) Next, after both surfaces of the silicon base material 200 are mirror-polished, as shown in FIG. 8B, one side of the silicon base material 200 is formed from TEOS (TetraEthyl Ortho silicate) by plasma CVD (Chemical Vapor Deposition). A silicon oxide film 201 is formed.
Note that before the silicon oxide film 201 is formed, a boron doped layer for etching stop may be formed. In addition, the diaphragm 22 with high thickness accuracy can be formed by forming the diaphragm from the boron dope layer.

(C) Then, as shown in FIG. 8 (c), the silicon substrate 200 shown in FIG. 8 (b),
The glass substrate 300 shown in FIG. 8A is heated, and the anode and glass substrate 3 are formed on the silicon substrate 200.
A cathode is connected to 00, and a voltage of about 800 V is applied to perform anodic bonding.

(D) After the anodic bonding of the silicon substrate 200 and the glass substrate 300, the bonded substrate obtained in the step of FIG. 8 (c) is etched with an aqueous potassium hydroxide solution or the like, whereby FIG.
As shown in FIG. 2, the entire silicon substrate 200 is thinned.

(E) Then, a TEOS film 202 is formed on the entire upper surface of the silicon substrate 200 (the surface opposite to the surface to which the glass substrate 300 is bonded) by plasma CVD.
The TEOS film 202 is patterned with a resist for forming a recess 210 serving as the discharge chamber 21, a recess 240 serving as the reservoir 24, and a portion (see FIG. 1) serving as the recess 230 serving as the orifice 23. The film 202 is removed by etching.
Thereafter, as shown in FIG. 9E, the silicon substrate 200 is etched with an aqueous potassium hydroxide solution or the like, thereby forming a recess 210 serving as the discharge chamber 21 and a recess 240 serving as the reservoir 24.
And the recessed part 230 used as the orifice 23 is formed. At this time, the portion 41a to be the electrode extraction portion 41 is also etched to be thinned. In the wet etching step shown in FIG. 9E, 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, the bonding substrate is etched with a hydrofluoric acid aqueous solution to remove the TEOS film 202 formed on the silicon substrate 200. Then, as shown in FIG. 9 (f), laser processing is performed on the hole portion 25 a that becomes the ink supply hole 25 of the glass substrate 300 so that the ink supply hole 25 penetrates the glass substrate 300. Thus,
The electrode substrate 3 is manufactured.

(G) Next, on the surface of the silicon substrate 200 on which the recesses 210 to be the discharge chambers 21 are formed,
As shown in FIG. 9G, a droplet protective film 202 made of TEOS or the like is formed by, for example, CVD.

(H) Then, as shown in FIG. 9 (h), the electrode extraction part 41 is opened by RIE (Reactive Ion Etching) or the like. In addition, the silicon substrate 200 is machined or laser processed to penetrate the ink supply holes 25 into the recesses 240 serving as the reservoirs 24. As a result, a bonded substrate in which the cavity substrate 2 and the electrode substrate 3 are bonded is completed.
Note that a sealing agent (not shown) for sealing the space between the diaphragm 22 and the individual electrode 31 may be applied to the electrode extraction portion 41.

Next, the bonding process of the nozzle substrate 1, the cavity substrate 2 and the electrode substrate 3 will be described below with reference to FIG.
As shown in FIG. 10, an adhesive layer is formed on the bonding surface 1 a of the nozzle substrate 1, and the cavity substrate 2 having the electrode substrate 3 bonded thereto is bonded to the nozzle substrate 1.
By passing through the above manufacturing process, the joined body of the nozzle substrate 1, the cavity substrate 2 and the electrode substrate 3 is completed.
Finally, the bonded substrate to which the cavity substrate 2, the electrode substrate 3, and the nozzle substrate 4 are bonded is separated by dicing (cutting), and the inkjet head 10 is completed.

According to the present invention, when the water repellent film 12 and the hydrophilic film 13 are formed in the nozzle hole 11, argon,
Since plasma treatment with oxygen or the like is unnecessary, the water repellent film 12 and the hydrophilic film 13 can be formed uniformly. In addition, since the nozzle hole inner wall 1c of the nozzle hole 11 has a uniform ink affinity, ink ejection characteristics are stabilized, ink flying bending is suppressed, and print quality is improved. Furthermore, when the nozzle hole 11 is processed, it is not necessary to fill the nozzle hole 11 with a protective material or to reprocess the nozzle hole 11, and the process is simplified. Moreover, when forming the nozzle hole 11, it can be set as arbitrary nozzle shapes.

Embodiment 2. FIG.
FIG. 11 is an enlarged cross-sectional view of the vicinity of a nozzle hole of a nozzle substrate according to Embodiment 2 of the present invention. As shown in the figure, in the nozzle substrate 1, the surface of the nozzle substrate 1 including the ink discharge surface 1b is covered with the water-repellent film 12, and the other surface excluding the ink discharge surface 1b, that is, the nozzle hole inner wall 1c.
Surfaces such as the bonding surface 1 a and the like are further covered with a hydrophilic film 13 on the water-repellent film 12. That is, the surface of the ink ejection surface 1 b is the water repellent film 12, and the surface of the nozzle hole inner wall 1 c is the hydrophilic film 13. In this case, the material of the water repellent film 12 and the hydrophilic film 13 is the same as the material shown in the first embodiment.
Other configurations, operations, and effects are the same as in the case of the first embodiment, and a description thereof will be omitted.

A method for manufacturing the inkjet head 10 configured as described above will be described with reference to FIGS. Note that only the steps of forming the water repellent film 12 and the hydrophilic film 13 of the nozzle substrate 1 are described in the first embodiment.
Therefore, this part will be described, and the description of the manufacturing process of other parts will be omitted.

(G) A portion 110 serving as a nozzle hole is formed by the same steps as steps (a) to (f) described in the first embodiment. In this way, as shown in FIG. 12G, a portion 110a to be a first nozzle hole having a small diameter and a portion 110b to be a second nozzle hole having a large diameter are formed.

(H) Next, as shown in FIG. 12 (h), a water repellent material containing fluorine atoms is applied to the surface of the nozzle substrate 100 including the ink ejection surface 100b, the nozzle inner surface 100c, and the bonding surface 100a by dip coating. Then, the water repellent film 12 is formed. Since the water repellent material is the same as that shown in Embodiment 1, the description thereof is omitted.

(I) Next, as shown in FIG. 12 (i), a hydrophilic material is further applied to the surface of the nozzle substrate 100 including the ink discharge surface 100b, the nozzle hole inner wall surface 100c, and the bonding surface 100a by dip coating, A hydrophilic film 13 is formed. Since the hydrophilic material is the same as that shown in Embodiment Mode 1, the description thereof is omitted.
Thus, the hydrophilic film 13 is formed on the water repellent film 12.

(J) Finally, as shown in FIG. 12 (j), the hydrophilic film 13 formed on the surface of the water repellent film 12 on the ink ejection surface 100b is removed by polishing, and the water repellent film 12 appears on the surface. Like that.
Through the above manufacturing process, the nozzle substrate 1 is formed from the silicon base material 100.
Other manufacturing processes are the same as those shown in the first embodiment, and thus the description thereof is omitted.

Embodiment 3 FIG.
FIG. 13 is a perspective view of a droplet discharge device (inkjet printer) according to Embodiment 3 of the present invention. The inkjet head 10 obtained in the first and second embodiments can be manufactured using the nozzle substrate 1 manufactured with a high yield, and the inkjet printer 400 as shown in FIG. Obtainable.
The inkjet head 10 obtained by the manufacturing method of Embodiment 1 is an example of a droplet discharge head, and the droplet discharge head is not limited to the inkjet head 10,
Manufacture of color filters for liquid crystal displays, organic EL by changing various droplets
The present invention can also be applied to formation of a light emitting portion of a display device, discharge of a biological liquid, and the like.
The droplet discharge head obtained by the manufacturing method of Embodiment 1 can also be used for a piezoelectric drive type droplet discharge device and a bubble jet (registered trademark) type droplet discharge device.

1 is an exploded perspective view of a droplet discharge head according to a first embodiment of the present invention. The longitudinal cross-sectional view of the principal part of the state which assembled FIG. Sectional drawing of the principal part of FIG. The top view of the nozzle substrate of FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate of FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate following FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate following FIG. Sectional drawing which shows the manufacturing process of the joining board | substrate which joined the cavity board | substrate and the electrode substrate. FIG. 9 is a cross-sectional view showing a manufacturing process of the bonded substrate following FIG. Sectional drawing which shows the manufacturing process which joins the bonding substrate of a cavity substrate and an electrode substrate to a nozzle substrate. Sectional drawing of the principal part of the droplet discharge head concerning Embodiment 2 of this invention. Sectional drawing which shows the manufacturing process of the nozzle substrate of FIG. FIG. 6 is a perspective view of an ink jet printer according to a third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle substrate, 1a Joint surface, 1b Ink discharge surface (droplet discharge surface), 1c Nozzle hole inner wall (inner surface of nozzle hole), 2 Cavity substrate, 3 Electrode substrate, 10 Inkjet head, 11 Nozzle hole, 11a 1st Nozzle hole (small diameter hole), 11b Second nozzle hole (
(Large diameter hole), 12 water repellent film, 13 hydrophilic film, 100 silicon substrate, 100a bonding surface (surface on the large diameter hole side), 100b ink ejection surface (surface on the small diameter hole side), 100c inner surface of the nozzle, 40
0 Inkjet printer.

Claims (16)

A nozzle substrate having a nozzle hole for discharging a droplet, the droplet discharge surface of the nozzle hole is water-repellent, and the inner surface of the nozzle hole is hydrophilic.
Forming a water repellent film on at least a droplet discharge surface of the nozzle substrate;
Further forming a hydrophilic film on at least a droplet discharge surface and an inner surface of the nozzle hole of the nozzle base material on which the water-repellent film is formed;
Removing the hydrophilic film formed on the droplet discharge surface,
A method for manufacturing a nozzle substrate, comprising: 2. The step of forming a water-repellent film on at least a droplet discharge surface of the nozzle substrate is a step of forming the water-repellent film only on the droplet discharge surface of the nozzle substrate. Nozzle substrate manufacturing method. The step of forming a water-repellent film on at least a droplet discharge surface of the nozzle substrate is a step of forming the water-repellent film on a droplet discharge surface and an inner surface of a nozzle hole of the nozzle substrate. Item 2. A method for producing a nozzle substrate according to Item 1. The nozzle substrate according to claim 1, wherein the step of forming the water repellent film on at least a droplet discharge surface of the nozzle base material is a step of forming the water repellent film on the entire surface of the nozzle base material. Manufacturing method. The step of further forming a hydrophilic film on at least the droplet discharge surface and the inner surface of the nozzle hole of the nozzle substrate on which the water-repellent film is formed is a step of further forming the hydrophilic film on the entire surface of the nozzle substrate. The method for manufacturing a nozzle substrate according to claim 1, wherein: The method for manufacturing a nozzle substrate according to claim 1, wherein the hydrophilic film formed on the droplet discharge surface is removed by polishing. The formation of the water repellent film and the hydrophilic film is performed by dip coating.
A method for producing a nozzle substrate according to any one of claims 6 to 10. The method for producing a nozzle substrate according to claim 1, wherein the water repellent film is made of a silane compound containing a fluoroalkyl group. 9. The water repellent film is made of any one of trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, and tridecafluorooctyltrimethoxysilane. Nozzle substrate manufacturing method. The hydrophilic film is a silane coupling agent represented by XSi (OR) ₃ , where X is an amino group, and OR is a hydrolyzable functional group composed of an ethoxy group or a methoxy group. The method for manufacturing a nozzle substrate according to claim 1, wherein the nozzle substrate is provided. The hydrophilic film is composed of γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (
The method for producing a nozzle substrate according to claim 10, comprising any one of 2-aminoethyl) aminopropylmethyldimethoxysilane and γ- (2-aminoethyl) aminopropyltriethoxysilane. The method for manufacturing a nozzle substrate according to claim 1, wherein the nozzle base material is made of any one of silicon, stainless steel, and nickel. 13. The method of manufacturing a nozzle substrate according to claim 12, wherein the nozzle hole is formed by etching from both sides after the nozzle substrate made of silicon is thinned. 13. The method of manufacturing a nozzle substrate according to claim 12, wherein the nozzle hole is formed by drilling in the nozzle base material made of stainless steel or nickel. Manufactures a droplet discharge head using a method for manufacturing a nozzle substrate having a nozzle hole for discharging droplets, the droplet discharge surface of the nozzle hole being water-repellent and the inner surface of the nozzle hole being hydrophilic A way to
Forming a water repellent film on at least a droplet discharge surface of the nozzle substrate, and further forming a hydrophilic film on at least the droplet discharge surface and the nozzle hole inner surface of the nozzle substrate on which the water repellent film is formed. And a method of manufacturing a nozzle substrate including a step of removing the hydrophilic film formed on the droplet discharge surface. Method of manufacturing a droplet discharge head by a method of manufacturing a nozzle substrate having nozzle holes for discharging droplets, the droplet discharge surface of the nozzle holes being water-repellent and the inner surface of the nozzle holes being hydrophilic A method of manufacturing a droplet discharge device using
Forming a water repellent film on at least a droplet discharge surface of the nozzle substrate, and further forming a hydrophilic film on at least the droplet discharge surface and the nozzle hole inner surface of the nozzle substrate on which the water repellent film is formed. A method of manufacturing a droplet discharge device, comprising: a method of manufacturing a droplet discharge head by a method of manufacturing a nozzle substrate, including a step of removing the hydrophilic film formed on the droplet discharge surface.

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