JP2009029018A - Method for manufacturing nozzle substrate, nozzle substrate, liquid droplet delivering head, and liquid droplet delivering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a nozzle substrate or the like which can prevent a water repellent film from peeling caused by liquid droplet erosion of a ground, and is excellent in durability to the liquid droplets. <P>SOLUTION: The method for manufacturing the nozzle substrate 1 comprises the process for forming a nozzle hole 11 on the surface of the substrate 100 by etching processing, the process for sticking a supporting substrate 120 on the face of the substrate 100 on which the nozzle hole 11 is formed, the process for opening the nozzle hole 11 by thinning the face on opposite side to the face of the substrate 100 on which the nozzle hole 11 is formed, the process for performing water repellent treatment of the face on the opposite side to the face of the substrate 100 on which the nozzle hole 11 is formed, and the process for releasing the supporting substrate 120 from the substrate 100. The process for water repellent treatment is performed by forming a metal base oxide film 13 on the face on the opposite side to the face of the substrate 100 on which the nozzle hole 11 is formed, and forming the water repellent film 14 on the metal base oxide film 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

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 element, 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 high-quality printing, image quality, and the like for inkjet heads, and there has been a demand for higher nozzle density and improved ejection performance. For this reason, various devices and proposals have been made for the nozzle portion of the inkjet head.
In an ink jet head, in order to improve ink ejection characteristics, it is desirable to adjust the thickness of the substrate so that the flow path resistance of the nozzle portion is adjusted and the optimum nozzle length is obtained.
When manufacturing such a nozzle substrate, an ICP (Inductivel) is formed from one surface of the silicon substrate.
y Coupled Plasma) Performs anisotropic dry etching using electric discharge to form first recesses (small-diameter recesses serving as discharge portions) and second recesses (large-diameter recesses serving as introduction portions) having different inner diameters in two stages After that, a part of the opposite surface is dug down by anisotropic wet etching to adjust the length of the nozzle hole (for example, see Patent Document 1).

On the other hand, there is also a method in which after the silicon substrate is polished to a desired thickness in advance, the both sides of the silicon substrate are dry-etched to form the discharge part and the introduction part of the nozzle hole (
For example, see Patent Document 2).

Japanese Patent Laid-Open No. 11-28820 (pages 4-5, FIGS. 3 and 4) Japanese Patent Laid-Open No. 9-57981 (page 2 to page 3, FIGS. 1 and 2)

In the technique described in Patent Document 1, since the ejection surface on which the nozzle hole opens is located on the bottom surface of the recess that is stepped down from the surface of the nozzle substrate, the ink droplet may be bent and the nozzle hole may be clogged. When paper dust, ink, etc. that cause
These were wiped with rubber pieces or felt pieces, but the wiping work was not easy.

In the technique described in Patent Document 2, the silicon base material must be made thinner as the density of the ink jet head increases. However, such a silicon base material is easily cracked during the manufacturing process and thus becomes expensive. . In dry etching, cooling is performed with helium gas or the like from the back surface of the substrate so that the processing shape is stable. However, when the nozzle hole penetrates, the helium gas leaks and etching may not be possible. It was.

For this reason, a concave part that becomes a nozzle hole is formed in advance in a silicon base material, and a double-sided adhesive sheet that has a release layer whose adhesive strength is easily reduced by stimuli such as ultraviolet rays or heat is bonded to the surface on which the concave part is formed. There is also a method of opening a nozzle hole (concave portion) by thinning the silicon base material by grinding or etching from the surface opposite to the surface on which the concave portion is formed.
In such a nozzle substrate manufacturing method, an ink repellent film is formed on the surface on the ink ejection side.
Before forming the ink repellent film, an oxide film (SiO ₂ film) is formed in order to increase the adhesion of the ink repellent film and provide ink resistance. This SiO ₂ film has a temperature at which the adhesive sheet does not deteriorate (
The film is formed by an ECR sputtering apparatus or the like that can form a dense film at room temperature.

However, the ink resistance of the SiO ₂ film is insufficient and there is a problem in durability. In particular,
When alkaline ink is used and the inkjet head is driven to discharge for a long period of time, the ink soaks from the portion not completely covered with the ink repellent film (pinhole), and Si
In some cases, the surface of the O ₂ film was corroded and the ink-repellent film was peeled off by wiping.

The present invention was made to solve the above problems, and even when droplets are driven to discharge over a long period of time, it is possible to prevent peeling of the water-repellent film due to underlying droplet erosion, An object of the present invention is to provide a nozzle substrate manufacturing method, a nozzle substrate, a droplet discharge head, and a droplet discharge device that are excellent in durability against droplets.

The method for manufacturing a nozzle substrate according to the present invention includes a step of forming nozzle holes on the surface of a base material by etching, a step of bonding a support substrate to a surface of the base material on which nozzle holes are formed, and a nozzle hole of the base material The step of thinning the surface opposite to the surface on which the nozzles are formed to open the nozzle holes, the step of water repellent treatment of the surface of the substrate opposite to the surface on which the nozzle holes are formed, and the support substrate as the substrate A method of manufacturing a nozzle substrate having a step of peeling from a metal-based oxide film after forming a metal-based oxide film on a surface opposite to the surface on which the nozzle holes of the substrate are formed. This is performed by forming a water repellent film on the oxide film.

Since the support substrate is bonded to the surface of the base material on which the nozzle holes are formed, the surface opposite to the surface on which the nozzle holes are formed is thinned to open the nozzle holes. The base material is not cracked or chipped during manufacture, handling is easy, and yield is improved.
In the above manufacturing process, after forming a highly water-resistant metal-based oxide film on the surface of the substrate opposite to the surface on which the nozzle holes are formed, that is, the surface on the droplet discharge side, and further Since the water-repellent film is formed on the nozzle substrate, the water-repellent film is not peeled off when the base material is eroded in the nozzle substrate manufactured using the base material. Thus, the water repellency can be maintained on the surface of the nozzle hole on the droplet discharge side for a long period of time, and the durability against the droplet is excellent, and the stability of the droplet discharge can be ensured.

In the nozzle substrate manufacturing method according to the present invention, the metal-based oxide film is any one of hafnium oxide, tantalum oxide, titanium oxide, indium tin oxide, and zirconium oxide.

Hafnium oxide, tantalum oxide, titanium oxide, indium tin oxide, and zirconium oxide are excellent as water-resistant protective films because they are highly resistant to chemicals and difficult to etch.

In the method for manufacturing a nozzle substrate according to the present invention, the metal-based oxide film is formed by any one of facing target sputtering, ECR sputtering, and ion beam sputtering.

At a temperature at which the support substrate does not peel off, a dense metal oxide film having excellent durability and high adhesion to the base material can be formed.

A nozzle substrate according to the present invention is a nozzle substrate having a nozzle hole for discharging a droplet and having a water-repellent film provided on a surface of the nozzle hole on the droplet discharge side, and the droplet discharge side of the nozzle hole A water repellent film is provided on this surface through a metal oxide film.

Since the water repellent film is provided on the surface of the nozzle substrate on the droplet discharge side through a highly water-resistant metal-based oxide film, the water repellent film does not peel off due to the erosion of the base material. Thereby, the water repellency of the surface of the nozzle substrate on the liquid droplet ejection side can be maintained for a long period of time, the durability against the liquid droplets is excellent, and the stability of liquid droplet ejection can be ensured.

Further, in the nozzle substrate according to the present invention, the metal-based oxide film has hafnium oxide, tantalum oxide,
One of titanium oxide, indium tin oxide, and zirconium oxide.

Hafnium oxide, tantalum oxide, titanium oxide, indium tin oxide, and zirconium oxide are excellent as water-resistant protective films because they are highly resistant to chemicals and difficult to etch.

  A droplet discharge head according to the present invention includes the nozzle substrate described above.

It is possible to maintain the water repellency of the surface of the nozzle substrate on the droplet discharge side for a long period of time and to ensure the stability of droplet discharge.

  A droplet discharge apparatus according to the present invention is equipped with the droplet discharge head described above.

It is possible to maintain the water repellency of the surface of the nozzle substrate on the droplet discharge side for a long period of time and to ensure the stability of droplet discharge.

Embodiment 1 FIG.
1 is an exploded perspective view of a droplet discharge head according to Embodiment 1 of the present invention, FIG. 2 is a longitudinal sectional view of a main part in a state where the droplet discharge head of FIG. 1 is assembled, and FIG. It is an enlarged view of a nozzle hole.
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 discharging ink droplets is, for example, a nozzle hole portion formed in a two-stage cylindrical shape with different diameters, that is, located on the ink discharge surface 1b side, and the tip opens to the ink discharge surface 1b. The discharge portion 11a having a small diameter and the introduction portion 11b having a large diameter located on the bonding surface 1a side to be bonded to the cavity substrate 2 and having a rear end opened to the bonding surface 1a are perpendicular to the substrate surface and It is provided on the same axis.

As shown in FIG. 3, the ink discharge surface 1b of the nozzle substrate 1 has hafnium oxide (
A water repellent film (ink repellent film) 14 is provided through a metal oxide film 13 made of HfO ₂ ). Further, a hydrophilic film (ink affinity film) 12 made of SiO ₂ is formed on the inner wall 1c of the nozzle hole 11 and the bonding surface 1a.
In this way, 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 flying direction of the ink droplets and eliminating the scattering of the ink droplets. Variations in the discharge amount can be suppressed.

The cavity substrate 2 is made from a silicon substrate. The cavity substrate 2 has a discharge recess 2
10, an orifice recess 230 and a reservoir recess 240 are formed. The discharge recess 210 (discharge chamber 21) and the reservoir recess 240 (reservoir 24) communicate with each other through the orifice recess 230 (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. An ink supply hole 34 penetrating an electrode substrate 3 to be described later is formed at the bottom of the reservoir 24, and ink is supplied from an ink cartridge (not shown) through the ink supply hole 34. The bottom wall of the discharge chamber 21 is a diaphragm 22. Note that thermal oxidation or plasma CVD (Chemical CVD) 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 by Vapor Deposition). This insulating film 26
Prevents the occurrence of dielectric breakdown or short circuit when the inkjet head 10 is driven.

The electrode substrate 3 is produced from a glass substrate. 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 310
Inside, individual electrodes 31 made of ITO (Indium Tin Oxide) are formed by sputtering. Therefore, the gap formed between the diaphragm 22 and the individual electrode 31 is determined by the depth of the recess 310 and the thickness of the insulating film 26 covering the individual electrode 31 and the diaphragm 22.

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 29 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 28 on a cavity board | substrate are connected through drive control circuits 40, such as an IC driver.

Next, the operation of the inkjet head 10 configured as described above will be described. When the drive control circuit 40 is driven and a charge is supplied to the individual electrode 31 to be positively charged, the diaphragm 22 is negatively charged and an electrostatic force is generated between the individual electrode 31 and the diaphragm 22. This electrostatic force
The diaphragm 22 is attracted to the individual electrode 31 and bends. As a result, the volume of the discharge chamber 21 increases. When the supply of electric charges 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 ink in the discharge chamber 21 is reduced by the pressure at that time. A part of the ink is discharged from the nozzle hole 11 as an ink droplet. 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. FIG. 4 is a top view showing the nozzle substrate 1 according to the embodiment of the present invention.
FIG. 10 is a cross-sectional view showing the manufacturing process of the nozzle substrate 1 (cross-sectional view of FIG. 4 cut along the line AA), and FIGS. 11 to 12 are cross-sectional views showing the bonding process of the cavity substrate 2 and the electrode substrate 3. FIG. 13 is a manufacturing process diagram for manufacturing the inkjet head 10 by bonding the nozzle substrate 1 to the bonding substrate of the cavity substrate 2 and the electrode substrate 3.

First, the manufacturing process of the nozzle substrate 1 will be described with reference to FIGS.
In addition, the numerical value described below shows an example, and is not limited to this.
(A) As shown in FIG. 5A, a silicon substrate 100 having a thickness of 280 μm is prepared, set in a thermal oxidation apparatus (not shown), an oxidation temperature of 1075 ° C., an oxidation time of 4 hours, oxygen and water vapor. Is subjected to thermal oxidation treatment under the conditions of the mixed atmosphere, and the surface of the silicon substrate 100 has a thickness of 1 μm of SiO.
_Two films 101 are formed uniformly.

(B) As shown in FIG. 5B, a resist 102 is coated on a bonding surface (a surface to be bonded to the cavity substrate 2 and also referred to as a surface on the rear end side) 100a of the silicon base material 100. Then, the portion 110a to be the discharge portion is patterned.

(C) As shown in FIG. 5C, the silicon substrate 100 is half-etched with, for example, a buffered hydrofluoric acid aqueous solution (hydrofluoric acid aqueous solution: ammonium fluoride aqueous solution = 1: 6) to obtain the SiO ₂ film 1.
Make 01 thinner. At this time, the surface of the ink discharge side (also referred to as the front end side) 100b SiO
_{The two} films 101 are also etched, and the thickness of the SiO ₂ film 101 is reduced.

(D) As shown in FIG. 5D, the resist 102 of the silicon substrate 100 is removed by washing with sulfuric acid or the like.

(E) As shown in FIG. 6 (e), resist 1 is formed on the bonding surface 100 a side of the silicon substrate 100.
03 is coated, and a portion 110b to be a discharge portion is patterned.

(F) As shown in FIG. 6F, the silicon substrate 100 is etched with a buffered hydrofluoric acid aqueous solution (hydrofluoric acid aqueous solution: ammonium fluoride aqueous solution = 1: 6) to form a portion 110b that becomes a nozzle hole.
The SiO ₂ film 101 of the silicon substrate 100 is opened. At this time, the surface 10 on the ink discharge side
The SiO ₂ film 101 of 0b is etched and completely removed.

(G) As shown in FIG. 6G, the resist 103 provided on the bonding surface 100a side of the silicon substrate 100 is removed by washing with sulfuric acid or the like.

(H) As shown in FIG. 7 (h), an ICP dry etching apparatus (not shown) performs S
The opening of the iO ₂ film 101 is anisotropically dry-etched vertically at a depth of 25 μm, and the introduction part 1
1a is formed. In this case, C ₄ F ₈ and SF ₆ are used as the etching gas, and these etching gases may be used alternately. Here, C ₄ F ₈ is used to protect the side surface of the groove so that etching does not proceed on the side surface of the groove to be formed, and SF ₆ is the silicon substrate 100.
Used to promote vertical etching.

(I) As shown in FIG. 7 (i), half etching is performed with a buffered hydrofluoric acid solution so that only the SiO ₂ film 101 in the portion to be the discharge portion is eliminated.

(J) As shown in FIG. 7 (j), the SiO ₂ film 10 is formed by an ICP dry etching apparatus.
The first opening is anisotropically dry-etched vertically at a depth of 40 μm to form a discharge portion 11b.

(K) after the SiO ₂ film 101 remaining on the surface of the silicon substrate 100 is removed by hydrofluoric acid solution, the silicon substrate 100 was set in a thermal oxidizer (not shown), oxidation temperature 1000 ° C., oxidation time 2 hours Then, a thermal oxidation treatment is performed under conditions in an oxygen atmosphere, and as shown in FIG. 7 (k), the side surface of the introduction portion 11a and the discharge portion 11b is further formed on the bonding surface 100a and the ink discharge side surface 100b of the silicon substrate 100. The SiO ₂ film 12 having a thickness of 0.1 μm is uniformly formed on the bottom surface.

(L) FIG. 8 (l) (hereinafter, until reaching FIG. 8 (o), the silicon substrate 1 shown in FIG. 7 (k)
As shown in a state in which the top and bottom of 00 are reversed, the support substrate 120 made of a transparent material such as glass,
A double-sided tape 50 having a self-peeling layer 51 whose adhesion is easily reduced by stimulation such as ultraviolet rays or heat is attached. When the surface of the self-peeling layer 51 of the double-sided tape 50 bonded to the support substrate 120 and the bonding surface 100a of the silicon base material 100 face each other and are bonded together in a vacuum, air bubbles are not adhered to the bonding interface and are adhered cleanly. The Here, if air bubbles remain at the bonding interface, the thickness of the silicon substrate 100 that is thinned by the polishing process varies. Double-sided tape 50
For example, SELFA-BG (registered trademark: manufactured by Sumitomo Chemical Co., Ltd.) is used.

(M) As shown in FIG. 8 (m), the surface 100b on the ink discharge side of the silicon substrate 100 is ground by a back grinder (not shown), and the silicon substrate 100 is opened until the leading end of the introduction portion 11a is opened. Thin out. Furthermore, the surface 100b on the ink ejection side may be polished by a polisher or a CMP apparatus, and the leading end of the introduction portion 11a may be opened. At this time, the inner walls of the introduction part 11a and the discharge part 11b are washed by a water washing and removing process of the abrasive in the nozzle.
Alternatively, the opening of the leading end portion of the introducing portion 11a may be performed by dry etching. For example, by dry etching using SF ₆ as an etching gas, the silicon substrate 100 is thinned to the tip of the introduction portion 11a, and the SiO ₂ film 12 at the tip of the introduction portion 11a exposed on the surface is CF
_It may be removed by dry etching using an etching gas such as ₄ or CHF ₃ .

(N) As shown in FIG. 8 (n), on the surface 100b on the ink ejection side of the silicon substrate 100,
Metal-based oxide film 1 made of hafnium oxide (HfO ₂ ) using an opposed target sputtering apparatus
3 is formed with a thickness of 0.1 μm. Here, the metal-based oxide film 13 made of hafnium oxide.
The film formation may be performed at a temperature (about 100 ° C.) or less at which the self-peeling layer 51 does not react.
In addition, it may be performed by ion beam sputtering or the like, and is not limited to the sputtering method. However, considering durability and the like, it is necessary to form a dense film, and it is desirable to use an apparatus capable of forming a dense film at room temperature, such as an ECR sputtering apparatus. If the film can be formed at a temperature that does not affect the self-peeling layer 51 and the adhesion to the silicon substrate 100 can be secured, the film forming method is not limited to sputtering and the like, but CVD (Chemical Vapor Depositio)
n) etc. may be used.

(O) As shown in FIG. 8 (o), a water repellent treatment (ink repellent treatment) is applied to the surface 100 b on the ink ejection side of the silicon substrate 100. That is, a water-repellent material containing F atoms is further formed by vapor deposition or dipping on the metal-based oxide film 13 made of hafnium oxide formed on the ink discharge side surface 100b. A water repellent film 14 is formed on the metal layer 100b via a metal oxide film 13. At this time, the inner walls of the introduction part 11a and the discharge part 11b are also subjected to water repellent treatment.

(P) FIG. 9 (p) (hereinafter, until reaching FIG. 9 (s), the silicon substrate 1 shown in FIG. 8 (o)
As shown in FIG. 5, the surface 10 on the ink ejection side subjected to water repellent treatment is shown.
A protective film 60 is affixed to 0b. Here, for example, E-MASK (registered trademark:
Nitto Denko) is used.

(Q) As shown in FIG. 9 (q), UV light is irradiated from the support substrate 120 side.

(R) As shown in FIG. 9 (r), the self-peeling layer 51 of the double-sided tape 50 is formed on the silicon substrate 10.
The support substrate 120 is detached from the silicon base material 100 by peeling from the zero bonding surface 100a.

(S) As shown in FIG. 9 (s), the water repellent formed excessively on the bonding surface 100a side of the silicon substrate 100 and on the inner walls of the introduction part 11a and the discharge part 11b by Ar sputtering or O ₂ plasma treatment. The film 14 is removed.
Thereafter, in order to increase the adhesive strength of the nozzle substrate 100, it is immersed in a primer treatment solution for 1 hour, rinsed with pure water, and baked at 80 ° C. for 1 hour. At this time, for example, a silane coupling agent (model number: SH6020, manufactured by Toray Dow) is used as the primer treatment liquid.

(T) As shown in FIG. 10 (t) (hereinafter, the silicon substrate 100 shown in FIG. 9 (s) is turned upside down until reaching FIG. 10 (u)), the silicon substrate 100 joint surfaces 10
0a (surface opposite to the surface 100b on the ink discharge side on which the protective film 60 is attached) is adsorbed and fixed to the suction jig 70 and attached to the surface 100b on the ink discharge side as a support tape. The protective film 60 is peeled off.

(U) As shown in FIG. 10 (u), the suction fixing of the suction jig 70 is released. Thus, the nozzle substrate 1 formed by laminating the metal-based oxide film 13 made of hafnium oxide and the water-repellent film 14 is formed on the surface 100b on the ink ejection side.
Through the above steps, the nozzle substrate 1 is formed from the silicon base material 100.

In the above description, the case where the metal-based oxide film 13 made of hafnium oxide (HfO ₂ ) is used as the ink-resistant protective film on the surface 100b on the ink discharge side is shown. Such hafnium oxide has a very high chemical resistance and is a difficult-to-etch material that cannot be wet-etched, and is suitable as an ink-resistant protective film. Further, as the metal oxide film 13, tantalum oxide (
Ta ₂ O ₅ ), titanium oxide (TiO ₂ ), indium tin oxide (ITO), and zirconium oxide (ZrO ₂ ) may be used. Also in this case, it is a difficult-to-etch material that has high chemical resistance and cannot be wet etched, and is suitable as an ink-resistant protective film.
Other materials can be used as the metal-based oxide film 13 as long as the material is not limited to the above materials and has high chemical resistance. The water-repellent film 14 has a property of strongly bonding to the base material by a dehydration condensation reaction, and the ink-resistant protective film is an optimum base material for the water-repellent film 14 as described above, and OH groups are likely to adhere to the surface. An oxide film is desirable.

According to the manufacturing method of the nozzle substrate 1 according to the first embodiment, the nozzle hole 1 of the silicon base material 100
1 is formed on the surface on which the 1 is formed, that is, the bonding surface 100a, with the double-sided tape 50 interposed therebetween.
0 was bonded, and the silicon substrate 100 was made thinner than the surface 100b on the ink discharge side so as to open the nozzle hole 11. Therefore, in the manufacturing process of the nozzle hole 11, the silicon substrate 10
0 is not cracked or chipped, handling is easy, and yield is improved.
Further, in the above manufacturing process, a metal-based oxide film 13 such as hafnium oxide having high ink resistance is formed on the surface 100b on the ink ejection side of the silicon substrate 100, and the water-repellent film 1 is formed thereon.
4 is formed, the peeling of the water repellent film 14 caused by the erosion of the base material is eliminated. Accordingly, the water repellency of the surface 100b on the ink discharge side can be maintained for a long time, and the stability of ink discharge can be ensured.

Next, a method for manufacturing the cavity substrate 2 and the electrode substrate 3 will be described.
Here, a method of manufacturing the cavity substrate 2 from the silicon substrate 200 after bonding the silicon substrate 200 to the electrode substrate 3 will be described with reference to FIGS. 11 and 12.

(A) As shown in FIG. 11 (a), a glass substrate 300 made of borosilicate glass or the like is coated with gold /
Etching with hydrofluoric acid using a chrome etching mask,
2 is formed. 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. Then, the electrode substrate 3 is manufactured by forming a hole 34a that becomes the ink supply hole 34 by a drill or the like.

(B) After both surfaces of the silicon substrate 200 are mirror-polished, as shown in FIG. 11B, on one surface of the silicon substrate 200, plasma CVD (Chemical Vapor Deposition) is used.
A silicon oxide film (insulating film) 26 made of TEOS (TetraEthylorthosilicate) is formed. In addition, before forming the silicon base material 200, a boron dope 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 fabricated as shown in FIG. 11A are heated to 360 ° C., and the silicon substrate 200 is connected to the anode and the electrode substrate 3 is connected to the cathode. 800
A voltage of about V is applied and bonding is performed by anodic bonding as shown in FIG.

(D) After the silicon substrate 200 and the electrode substrate 3 are anodically bonded, as shown in FIG. 11D, the bonded silicon substrate 200 is etched with an aqueous potassium hydroxide solution or the like, and the silicon substrate 200 is thinned. Turn into.

(E) A TEOS film 260 is formed on the entire upper surface of the silicon substrate 200 (the surface opposite to the surface on which the electrode substrate 3 is bonded) by plasma CVD. Then, the TEOS film 260 is patterned with a resist for forming a recess 210 to be the discharge chamber 21, a recess 230 to be the orifice 23, and a recess 240 to be the reservoir 24.
The EOS film 260 is removed by etching (see FIG. 12E).
Then, by etching the silicon substrate 200 with a potassium hydroxide aqueous solution or the like,
As shown in FIG. 12 (e), the recess 210 serving as the discharge chamber 21 and the recess 2 serving as the orifice 23.
30 and a recess 240 to be the reservoir 24 are formed. At this time, the portion that becomes the electrode extraction portion 29 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, the TEOS film 2 formed on the upper surface of the silicon substrate 200 is etched with an aqueous hydrofluoric acid solution as shown in FIG.
60 is removed.

(G) On the surface of the silicon substrate 200 on which the recesses 210 and the like serving as the discharge chambers 21 are formed, FIG.
As shown in (g), a TEOS film (insulating film) 26 is formed by plasma CVD.

(H) By RIE (Reactive Ion Etching) or the like, as shown in FIG. Further, laser processing is performed on the hole portion that becomes the ink supply hole 34 of the electrode substrate 3, and the bottom portion of the concave portion 240 that becomes the reservoir 24 of the silicon base material 200 is penetrated to form the ink supply hole 34. Further, the open end of the gap between the diaphragm 22 and the individual electrode 31 is filled with a sealing material 27 such as epoxy resin and sealed. Further, the common electrode 28 is formed on the end portion of the silicon substrate 200 by sputtering.

As described above, the cavity substrate 2 is manufactured from the silicon base material 200 bonded to the electrode substrate 3.
Finally, the nozzle substrate 1 manufactured as described above (FIGS. 5 to 10) is bonded to the cavity substrate 2 by bonding or the like, whereby the inkjet head 10 shown in FIG. 13 is completed.

According to the method for manufacturing the inkjet head 10 according to the first embodiment, the cavity substrate 2 is produced from the silicon substrate 200 in a state of being bonded to the electrode substrate 3 produced in advance. 200 is supported, and the silicon substrate 200
Even if the plate is made thin, it is not cracked or chipped, and handling becomes easy. Therefore, the yield is improved as compared with the case where the cavity substrate 2 is manufactured alone.

Embodiment 2. FIG.
FIG. 14 is a perspective view showing an ink jet recording apparatus equipped with an ink jet head having the nozzle substrate 1 obtained by the nozzle substrate manufacturing method according to the first embodiment. An ink jet recording apparatus 400 shown in FIG. 14 is an ink jet printer, and is equipped with the ink jet head 10 according to the first embodiment. Therefore, the ink jet recording apparatus 400 has good ejection characteristics and high density. It is possible to obtain the ink jet recording apparatus 400 that can increase the accuracy of the landing position and can perform stable and high-quality printing.
In addition to the ink jet recording apparatus 400 shown in FIG. 14, the ink jet head 10 shown in Embodiment 1 can produce various color droplets to produce a color filter for a liquid crystal display and a light emitting portion of an organic EL display apparatus. It can be used as a droplet discharge device for various uses such as the formation of micromolecules and the production of microarrays of biomolecule solutions used for genetic testing.

1 is an exploded perspective view of a droplet discharge head according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view of a main part in a state where the droplet discharge head of FIG. 1 is assembled. Sectional drawing which expanded the nozzle hole part of FIG. The top view of the nozzle substrate of FIG. Sectional drawing of the manufacturing process of the nozzle substrate of FIG. Sectional drawing of the manufacturing process of the nozzle substrate following FIG. Sectional drawing of the manufacturing process of the nozzle substrate following FIG. Sectional drawing of the manufacturing process of the nozzle substrate following FIG. Sectional drawing of the manufacturing process of the nozzle substrate following FIG. Sectional drawing of the manufacturing process of the nozzle substrate following FIG. Sectional drawing of the manufacturing process of a cavity board | substrate and an electrode substrate. Sectional drawing of the manufacturing process following FIG. Sectional drawing of the principal part of the droplet discharge head manufactured by the manufacturing process of FIGS. FIG. 6 is a perspective view of an ink jet recording apparatus according to Embodiment 2 of the present invention.

Explanation of symbols

1 nozzle substrate, 1a bonding surface (rear end surface), 1b ink ejection surface (front end surface),
2 cavity substrate, 3 electrode substrate, 10 inkjet head, 11 nozzle hole, 1
DESCRIPTION OF SYMBOLS 1a Ejection part, 11b Introduction part, 12 Hydrophilic film (parent ink film), 13 Metal oxide film, 1
4 Water repellent film (ink repellent film), 21 discharge chamber, 22 diaphragm, 23 orifice, 24 reservoir, 26 insulating film, 27 sealing material, 28 common electrode, 31 individual electrode, 34 ink supply hole, 40 drive control circuit , 100 Silicon base material, 100a Bonding surface (surface on the rear end side)
, 100b Ink discharge side surface (tip side surface), 120 support substrate, 400 inkjet recording apparatus.

Claims (7)

The step of forming nozzle holes on the surface of the base material by etching, the step of attaching a support substrate to the surface of the base material on which the nozzle holes are formed, and the surface of the base material on which the nozzle holes are formed are opposite. A step of opening the nozzle hole by thinning the surface on the side, a step of water-repellent treatment of the surface of the substrate opposite to the surface on which the nozzle hole is formed, and peeling the support substrate from the substrate A method of manufacturing a nozzle substrate comprising the steps of:
In the water repellent treatment, a metal oxide film is formed on a surface of the base opposite to the surface on which the nozzle holes are formed, and then a water repellent film is formed on the metal oxide film. A method for manufacturing a nozzle substrate, comprising: 2. The method of manufacturing a nozzle substrate according to claim 1, wherein the metal-based oxide film is any one of hafnium oxide, tantalum oxide, titanium oxide, indium tin oxide, and zirconium oxide. 3. The method of manufacturing a nozzle substrate according to claim 1, wherein the metal-based oxide film is formed by any one of facing target sputtering, ECR sputtering, and ion beam sputtering. A nozzle substrate having a nozzle hole for discharging a droplet, and having a water-repellent film provided on a surface of the nozzle hole on a droplet discharge side;
A nozzle substrate, wherein the water-repellent film is provided on a surface of the nozzle hole on the droplet discharge side via a metal-based oxide film. The nozzle substrate according to claim 4, wherein the metal-based oxide film is any one of hafnium oxide, tantalum oxide, titanium oxide, indium tin oxide, and zirconium oxide.   A liquid droplet ejection head comprising the nozzle substrate according to claim 4.   A droplet discharge apparatus, comprising the droplet discharge head according to claim 6.

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