JP2008279707A - Manufacturing method for nozzle substrate, liquid droplet ejection head and liquid droplet ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a manufacturing method or the like for a nozzle substrate which can form a desired nozzle shape. <P>SOLUTION: The manufacturing method includes the process of opening a nozzle supply port 31B-1 from one surface side of a silicon substrate 51 and forming a recess to be a nozzle 31, the process of applying a liquid substance and forming a coating film 54 which covers a surface which has the recess to be the nozzle 31, and the process of forming a nozzle ejection port 31A-1 by performing anisotropic wet etching and penetrating the recess from a surface of the opposite side to the surface which has the recess to be the nozzle 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a nozzle substrate on which nozzles are formed by microfabrication, a droplet discharge head that discharges droplets of ink or the like, and a method for manufacturing a droplet discharge device.

For example, microfabrication technology (MEMS: Micro) that forms fine elements by processing silicon, etc.
Electro Mechanical Systems) has made rapid progress. Examples of microfabricated elements formed by microfabrication technology include, for example, a droplet discharge head (inkjet head), a micropump, and an optical variable filter used in a recording (printing) apparatus such as a droplet discharge type printer. There are electrostatic actuators such as motors, pressure sensors and the like.

Here, a droplet discharge head will be described as an example of a microfabricated element. A droplet discharge type recording (printing) apparatus is used for printing in various fields regardless of whether it is for home use or industrial use.
The droplet discharge method is, for example, a method in which a droplet discharge head having a plurality of nozzles is moved relative to an object (paper, etc.), and droplets are discharged to a predetermined position of the object for printing or the like. It is. This method includes color filters for producing a display device using liquid crystals, display panels (OLEDs) using electroluminescence elements such as organic compounds,
It is also used in the production of microarrays of biomolecules such as DNA and proteins.

As a method of ejecting droplets from a nozzle by a droplet ejection head, for example, there is a method in which a liquid is heated and droplets are ejected by the pressure of generated air (bubbles). Also, a discharge chamber for storing liquid is provided in a part of the flow path, and the wall of at least one surface of the discharge chamber (here, the bottom wall)
Hereinafter, there is a method in which the wall is referred to as a diaphragm) and the pressure in the discharge chamber is increased by a shape change to discharge a droplet from a communicating nozzle. In addition, the diaphragm is a movable electrode, a voltage is applied between the electrode (fixed electrode) facing the diaphragm at a distance, and the generated electrostatic force (electrostatic attractive force is often used. In some cases, the diaphragm is displaced by the generated electrostatic attraction force and discharged by the pressure (see, for example, Patent Document 1).

JP 2000-52551 A

Here, consider a nozzle substrate having nozzles for ejecting liquid as droplets. The nozzle substrate is manufactured by performing anisotropic etching on a substrate by a dry etching method (dry etching, hereinafter referred to as dry etching) and a wet etching method (wet etching, hereinafter referred to as wet etching). In general, a process is often employed in which dry etching is performed from one surface side to form a nozzle shape, and wet etching is performed from the other surface until etching is performed through the nozzle. Here, in order to improve discharge performance, the shape of the nozzle is often formed in two or more steps that are close to a tapered shape.

For example, when wet etching is performed, a portion other than the portion where wet etching is performed (particularly the nozzle portion formed by dry etching) is not etched, so that the portion other than the portion where wet etching is performed is protected against etching (for example, oxidation protection film). Protect with silicon film.

However, for example, a deposit film (film generated by the deposition process) left after performing various deposition processes such as dry etching, and foreign matters such as dust (hereinafter referred to as particles) are formed as a portion serving as a nozzle. May adhere to the inside of the recessed part. Further, since the concave portion is formed in a direction perpendicular to the substrate and there is an edge portion, it is very difficult to uniformly form the side surface of the concave portion with a desired thickness. For this reason, when an etching resistant protective film is not formed in part, an etchant (etching solution) may infiltrate (wrap around) from the part, and the formed nozzle shape may collapse.

As a result, the discharge performance of the liquid droplets discharged from the nozzles may be lowered (for example, the discharge direction does not go straight (becomes oblique)). Also, if the discharge performance is too low, the nozzle substrate cannot be used, which may lead to a decrease in yield.

Accordingly, an object of the present invention is to obtain a nozzle substrate manufacturing method capable of forming a desired nozzle shape in order to solve such a problem. Another object of the present invention is to obtain a method for manufacturing a droplet discharge head or the like based on the nozzle substrate.

The method for manufacturing a nozzle substrate according to the present invention includes a step of opening a nozzle supply port from one surface side of a silicon substrate, forming a recess serving as a nozzle, and applying a liquid substance to form a recess serving as a nozzle. Performing a process of forming a film covering the surface and anisotropic wet etching,
And a step of forming a discharge port of the nozzle by penetrating the recess from a surface opposite to the surface where the recess serving as the nozzle is formed.
According to the present invention, since a liquid material is applied to the surface on which the concave portion is formed to form a film and wet etching is performed, for example, even if particles remain before the wet etching, the protective film By covering with, it is possible to reliably prevent the etchant from entering the concave portion serving as the nozzle and to accurately form the nozzle. Therefore, a nozzle substrate with high discharge performance can be manufactured, and further, the yield can be increased.

In the method for manufacturing a nozzle substrate according to the present invention, a silicon oxide film is formed on a silicon substrate before applying a liquid material to the surface on which the recess is formed.
According to the present invention, since the liquid substance is applied after the silicon oxide film is formed in advance, further protection can be performed after the entire surface of the silicon substrate is protected.

In the method for manufacturing a nozzle substrate according to the present invention, the liquid material is SOG or amorphous fluororesin.
According to the present invention, since the liquid material is SOG or amorphous fluororesin, the silicon substrate can be reliably protected against the etchant. In particular, SOG can be removed in the same process as the silicon oxide film.

Moreover, the manufacturing method of the nozzle substrate which concerns on this invention performs anisotropic wet etching of a silicon substrate using an organic alkaline solution.
According to the present invention, potassium hydroxide (KOH), tetramethylammonium hydroxide (TM
Since anisotropic wet etching is performed using an alkaline aqueous solution such as AH), anisotropic wet etching of silicon can be performed with high accuracy.

Moreover, the nozzle substrate manufacturing method according to the present invention forms a tapered or stepped nozzle such that the discharge port has a smaller diameter than the supply port.
According to the present invention, since the nozzle is formed so as to have a tapered shape or a stepped shape, a nozzle substrate with high ejection performance can be manufactured, for example, the ejected liquid droplet can be straightened more reliably. be able to.

In addition, the method for manufacturing a droplet discharge head according to the present invention includes a nozzle substrate manufactured by the above method, a channel for supplying liquid to the nozzles of the nozzle substrate, and a liquid added to a part of the channel. And a step of bonding a substrate provided with a pressing means for pressing.
According to the present invention, since the droplet discharge head is manufactured using the nozzle substrate manufactured by the above manufacturing method, it is possible to manufacture a droplet discharge head with high discharge performance. In addition, the yield can be increased.

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 using the droplet discharge head manufactured by the above manufacturing method, a device having high discharge performance can be manufactured. In addition, the yield can be increased.

The droplet discharge head according to the present invention is manufactured by the above manufacturing method.
According to the present invention, a droplet discharge head with high discharge performance can be obtained by manufacturing with the above manufacturing method.

In addition, a droplet discharge apparatus according to the present invention is equipped with the above-described droplet discharge head.
According to the present invention, a droplet discharge device with high discharge performance can be obtained by manufacturing with the above manufacturing method.

Embodiment 1 FIG.
FIG. 1 is an exploded view of a droplet discharge head according to a first embodiment of the present invention. FIG. 1 shows a face eject type liquid droplet ejection head as a representative of an electrostatic actuator. (For the sake of clarity, the components are shown in the following drawings including FIG. May be different from the actual relationship, and the upper side of the figure is the upper side and the lower side is the lower side). In FIG. 1, the electrode substrate 10 has a thickness of about 1 mm. In FIG. 1, the electrode substrate 10 is bonded to the lower surface of the cavity substrate 20 so as to face the diaphragm 22. In the present embodiment, a borosilicate heat-resistant hard glass is used as a material for the substrate constituting the electrode substrate 10. The electrode substrate 10 has a depth of about 0.25 μm, for example, in accordance with each discharge chamber 21 formed in the cavity substrate 20.
The groove portion 11 is provided on the inner side (particularly the bottom portion) of the individual electrode 12A, the lead portion 12B, and the terminal portion 12C facing the discharge chambers 21 (hereinafter referred to as “electrode portion 1” unless otherwise specified).
2). In the present embodiment, ITO (Indium Tin Oxide) doped with indium with tin oxide as an impurity is used as the material of the electrode portion 12, and the bottom surface of the groove portion 11 is, for example, about 0.1 μm by sputtering or the like. The film is formed with a thickness of. The liquid supply port 13 serves as an intake port for supplying liquid such as ink from an external tank (not shown) to the droplet discharge head.

The cavity substrate 20 is made of, for example, a silicon single crystal substrate whose surface has a (110) plane orientation (including this substrate, hereinafter, simply referred to as a silicon substrate). The cavity substrate 20 is formed with a concave portion that becomes the discharge chamber 21 (the bottom wall becomes the vibration plate 22 that becomes the driven portion) and a concave portion that becomes the reservoir 24 for storing the liquid discharged common to each nozzle. Yes. For example, anisotropic wet etching is used to form the recess. The reservoir 24 temporarily stores the liquid supplied via the liquid supply port 13 and supplies the liquid to each discharge chamber 21. Also, the cavity substrate 20
The common electrode terminal 27 provided on the top is for supplying the cavity substrate 20 with a charge opposite to the charge supplied to the electrode portion 12. Further, in order to insulate the individual electrode 12 </ b> A from the diaphragm 22, an insulating film 23 is formed on the lower surface of the diaphragm 22.

In the present embodiment, for example, a silicon substrate having a thickness of about 200 μm is used as the nozzle substrate 30, and the nozzle substrate 30 is bonded to the cavity substrate 20 on the surface opposite to the electrode substrate 10 (upper surface in the case of FIG. 1). The nozzle substrate 30 of the present embodiment is assumed to have a plurality of nozzles 31 formed in two stages that communicate with the discharge chamber 21. Outside of nozzle substrate 30 (upper surface in the case of FIG. 1)
A cylindrical nozzle having a small diameter (about 20 μm) on the liquid discharge side (referred to as nozzle discharge port 31A-1) that is opened in a circular shape on the surface of the nozzle is referred to as a first nozzle 31A. . In addition, an opening (nozzle supply) having a larger diameter (approximately 50 μm) on the liquid supply side, opened to be circular on the inner surface (the surface facing the cavity substrate 20, the lower surface in FIG. 1). A cylindrical nozzle having a mouth 31B-1 is referred to as a second nozzle 31B. Here, it is assumed that the centers of the circles formed by the first nozzle 31A and the second nozzle 31B are the same (concentric circles). The diaphragm 32 is provided in order to buffer the force propagating to the liquid stored in the reservoir 24 by pressurizing the diaphragm 22. Further, a narrow groove serving as an orifice 33 is provided on the inner surface so that the discharge chamber 21 and the reservoir 24 are communicated with each other, and the liquid stored in the reservoir 24 is discharged into the discharge chamber 2.
1 is a communication groove for supplying to No.1. Moreover, the recessed part 3 which has nozzle discharge port 31A-1 in a bottom face
4. In FIG. 1, the nozzle substrate 30 is the upper surface and the electrode substrate 20 is the lower surface. However, in actual use, the nozzle substrate 30 is usually the lower surface than the electrode substrate 20.

FIG. 2 is a cross-sectional view of the droplet discharge head. The terminal portion 12 </ b> C is exposed to the outside at the electrode outlet 26. The oscillation circuit 41 including, for example, a driver IC or the like is electrically connected to the terminal portion 12C, directly or via a wire 42 such as a wire or FPC (Flexible Print Circuit).
This circuit is connected to the common electrode terminal 27, and controls the supply and stop of electric charges (power) to the individual electrodes 12A and the cavity substrate 20 (the diaphragm 22). The oscillation circuit 41 oscillates at a predetermined frequency, for example, and supplies a charge by applying, for example, a pulse voltage to the individual electrode 12A. Oscillation circuit 41
Is driven to oscillate, for example, by selectively supplying a charge to each individual electrode 12A to be positively charged,
The diaphragm 22 is relatively negatively charged. At this time, the diaphragm 22 is attracted to the individual electrode 12A by the electrostatic force and bent. This increases the volume of the discharge chamber 21. When the charge supply is stopped, the diaphragm 22 returns to its original state, but at that time, the volume of the discharge chamber 21 also returns to its original state, and droplets are discharged by the pressure. For example, printing is performed by the droplets landing on an ejection target. In order to prevent the space (gap) between the individual electrode 12A and the diaphragm 22 from communicating with the outside air by exposing the terminal portion 12C to the outside, the sealing material 25 is sealed and the outside air is blocked. Yes.

In the present embodiment, in addition to the wet etching-resistant protective film formed on the entire substrate before the step of performing wet etching when the nozzle substrate 30 is manufactured, the substrate is further formed as at least a portion that becomes the nozzle 31. A recess (hereinafter referred to as a recess that becomes the nozzle 31) is covered with a wet etching resistant protective film formed by injecting a liquid material. For this reason, for example, even if the protection by the protective film applied to the entire substrate is not completely performed by particles or the like, the concave portion that becomes the nozzle 31 can be protected from the etchant. The nozzle substrate 30 having high discharge performance by performing such a process.
Then, a droplet discharge head having the nozzle substrate 30 is manufactured.

3 and 4 are diagrams illustrating a method for manufacturing the nozzle substrate 30. FIG. Next, based on FIG.3 and FIG.4, the procedure of the manufacturing method of the nozzle substrate 30 in this invention is demonstrated. Actually, a plurality of nozzle substrates 30 of droplet discharge heads are simultaneously formed from a silicon wafer, but only a part of them is shown in FIGS.

First, when etching a silicon substrate 51 having a thickness of about 200 μm, the silicon substrate 5
A silicon oxide film 52 to be a film (resist) for protecting 1 is formed to a thickness of, for example, about 1.2 μm (FIG. 3A). The film forming method is not particularly limited, but here, for example, a high temperature (
A thermal oxidation method is used in which the silicon substrate 51 is exposed to an oxygen and water vapor atmosphere at about 1075 ° C.). Here, as the silicon substrate 51, a silicon substrate having a (100) plane orientation is used.

Then, in order to perform patterning by selectively etching the silicon oxide film 52, a photolithography method is used to apply a photosensitive agent to be a resist film, and a portion of the resist film to be the first nozzle 31A is formed by exposure and development. Remove. Then, for example, a silicon oxide film in a portion to be the first nozzle 31A is immersed in a hydrofluoric acid aqueous solution, a buffered hydrofluoric acid aqueous solution (BHF: for example, a liquid in which a hydrofluoric acid aqueous solution and an ammonium fluoride aqueous solution are mixed at 1: 6) or the like. 52 is removed by etching to expose the silicon (FIG. 3B).

Furthermore, a portion to become the second nozzle 31B (nozzle supply port 31B-1) and the orifice 33
The portion of the silicon oxide film 52 that is to be removed is removed by half etching. The removal method is the same as in the case of the portion that becomes the first nozzle 31A, but the silicon oxide film 52 is left slightly for the portion that becomes the second nozzle 31B and the portion that becomes the orifice 33.
Silicon is not exposed (FIG. 3C). Such removal by half etching is repeated by the number of stages of the nozzles 31 (in this embodiment, two stages are used).

Next, dry etching is performed, and the diameter of the first nozzle 31A is about 20 for example.
A recess (hole) having a thickness of about 50 μm and a depth of about 50 μm is formed (FIG. 3D). 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 (Kutafluorocyclobutane) as a gas used for etching. Then, dry etching is performed. Then, the silicon oxide film 52 in the portion that becomes the second nozzle 31B and the portion that becomes the orifice 33 left by the half etching is removed by photolithography or the like (FIG. 3E).

Then, dry etching is performed, and the diameter of the second nozzle 31B is about 50 μm,
A recess (hole) having a depth of 50 μm is formed. 50 μm for the first nozzle 31A
Recesses are formed up to m deep portions. Further, the orifice 33 is simultaneously formed by dry etching (FIG. 3F). Again, the type of dry etching is not particularly limited. When the dry etching is completed, the silicon oxide film 52 formed as a protective film is removed (FIG. 3G). The removal of the silicon oxide film 52 is performed, for example, by wet etching the entire surface with the above-described hydrofluoric acid aqueous solution or the like. Then, a silicon oxide film 53 is formed on the entire surface as a protective film for further wet etching (FIG. 4H). Here, the film forming method is not particularly limited, but for example, a thermal oxidation method capable of forming a film regardless of unevenness may be used.

Here, the nozzle 3 is not exposed to an oxygen and water vapor atmosphere due to particles or the like, for example.
In some cases, the silicon oxide film 53 is not formed in the recess that becomes 1, and wet etching may be performed. Therefore, in the present embodiment, the coating film 54 is formed (formed) and covered by applying a liquid material to the surface (particularly, the recess serving as the nozzle 31) where the recess serving as the nozzle 31 is formed. (FIG. 4 (i)). For example, the coating film 54 is formed by solidifying a liquid material. As the liquid substance, for example, SOG (Spin On Glass), amorphous fluororesin, or the like is used. In particular, since SOG has the same material structure as the silicon oxide film, it can be removed in the same process as the silicon oxide film 53. Further, the method for applying the liquid substance is not particularly limited, and examples thereof include spin coating and potting. After forming the coating film 54,
Using the photolithography method, the silicon oxide film 53 is removed by wet etching to remove the portion that becomes the recess 34 for penetrating the nozzle 31 and the portion that becomes the diaphragm 32 (FIG. 4J).

Next, the silicon substrate is immersed in an etching solution to form a recess 34 and a diaphragm 32.
The portion to be formed is wet-etched, penetrating the nozzle 31 and forming the diaphragm 32 (FIG. 4 (k)). For wet etching of silicon, for example, an aqueous solution of potassium hydroxide (KOH) having a concentration of 32 weight percent, an aqueous solution of tetramethylammonium hydroxide (TMAH) (organic alkali solution) of 25 weight percent, or the like is used. Especially KOH aqueous solution, TM
The AH aqueous solution has a good selection ratio relationship with the silicon oxide film, and there is little variation in etching.
Good dimensional accuracy with respect to the plane. The TMAH aqueous solution is used as a developer.

Then, the silicon oxide film 53 and the coating film 54 formed as a protective film are removed (FIG. 4L). Further, a silicon oxide film 55 for ink resistance protection and insulation is formed on the entire surface (FIG. 4 (m)). Here, the silicon oxide film 55 is formed by a thermal oxidation method. For example, plasma CVD (Chemical Vapor Deposition) using TEOS (here, Tetraethyl orthosilicate Tetraethoxysilane) is used.
: Also referred to as TEOS-pCVD). Further, another material such as Al ₂ O ₃ (aluminum oxide (alumina)) may be used as the insulating film.

FIG. 5 is a diagram illustrating a manufacturing process of the droplet discharge head. Based on FIG. 5, a manufacturing process of a droplet discharge head including manufacturing of another substrate will be described. In practice, a plurality of droplet discharge head members are simultaneously formed from a silicon wafer, but only a part thereof is shown in FIG.

A groove 11 having a depth of 0.2 μm is formed in accordance with the shape pattern of the electrode portion 12 on one surface of a glass substrate of about 1 mm to be the electrode substrate 10. Then, using a method such as sputtering, ITO having a thickness of 0.1 μm is formed on the inner side (particularly the bottom wall) of the groove 11 to form the electrode 12. Further, the liquid supply port 13 is formed by a sandblasting method or a cutting process. Thereby, the electrode substrate 10 is produced (FIG. 5A).

For the substrate to be the cavity substrate 20, first, for example, one surface of the silicon substrate 61 having a low oxygen concentration with a (110) plane orientation is mirror-polished to a thickness of 220 μm. Next, the surface on which the boron-doped layer 62 is formed on the silicon substrate 61 is set on a quartz boat so as to face a solid diffusion source mainly composed of B ₂ O ₃ . Further, a quartz boat is set in a vertical furnace, and the inside of the furnace is made into a nitrogen atmosphere. For example, the temperature is raised to 1050 ° C. and held for 7 hours to diffuse boron into the silicon substrate 61 to form a boron doped layer 62. . At this time, a boron compound is formed on the surface of the boron dope layer 62 (not shown), but etching with a hydrofluoric acid aqueous solution is possible by oxidizing for 1 hour 30 minutes in an oxygen and water vapor atmosphere at 600 ° C. It is chemically changed to B ₂ O ₃ + SiO ₂ and removed by wet etching with a hydrofluoric acid aqueous solution. Further, the insulating film 2 is formed on the surface on which the boron doped layer 62 is formed by plasma CVD.
3 is formed (FIG. 5B). The insulating film 23 is formed by a plasma CVD method, for example, at a processing temperature of 360 ° C., a high frequency output of 250 W, a pressure of 66.7 Pa (0.5 Torr),
The gas flow rate is TEOS flow rate 100 cm ³ / min (100 sccm), oxygen flow rate 1000 c
A 0.1 μm film is formed under the condition of m ³ / min (1000 sccm).

Next, after heating the silicon substrate 61 and the electrode substrate 10 to 360 ° C., the electrode substrate 10 has a negative electrode,
A positive electrode is connected to the silicon substrate 61, and a voltage of 800V is applied to perform anodic bonding. Then, in the bonded substrate after anodic bonding, the surface of the silicon substrate 61 is ground until the thickness of the silicon substrate 61 becomes about 60 μm. Thereafter, in order to remove the work-affected layer, the silicon substrate 61 is wet-etched by about 10 μm with a potassium hydroxide solution having a concentration of 32 w%, for example. As a result, the thickness of the silicon substrate 61 is reduced to about 50 μm (FIG. 5C).

For example, a silicon oxide film 63 serving as an etching mask is formed on the wet etched surface by a plasma CVD method using TEOS. As film formation conditions for the silicon oxide film 63, for example, the processing temperature during film formation is 360 ° C., the high frequency output is 700 W, and the pressure is 33.3.
Pa (0.25 Torr), gas flow rate is TEOS flow rate 100 cm ³ / min (100 sc
cm) and an oxygen flow rate of 1000 cm ³ / min (1000 sccm). Film formation using TEOS can be performed at a relatively low temperature, and heating of the substrate can be suppressed as much as possible. Further, using photolithography, portions of the silicon oxide film 63 that become the discharge chamber 21, the reservoir 24, and the electrode outlet 26 are removed by etching (FIG. 5).
(D)). Here, for example, silicon is exposed in the portions that become the discharge chamber 21 and the electrode outlet 26, and the silicon oxide film 63 is left in the reservoir 24 by half etching. This is because the portion that becomes the reservoir 24 is made rigid by leaving silicon.

Next, the bonded substrate is immersed in a 35 wt% potassium hydroxide aqueous solution, and wet etching is performed until the thickness of the portion that becomes the discharge chamber 21 becomes about 10 μm. Further, the bonded substrate is immersed in a 3 wt% potassium hydroxide aqueous solution, and etching is continued until it is determined that the etching stop is sufficiently effective in the boron doped layer 62. Thus, by performing wet etching using the two types of potassium hydroxide aqueous solutions having different concentrations, the surface roughness of the diaphragm 22 to be formed is suppressed, and the thickness accuracy is 0.80 ± 0.05 μm or less. can do. As a result, the discharge performance of the droplet discharge head can be stabilized (
FIG. 5 (e)). When the wet etching is finished, the bonded substrate is immersed in a hydrofluoric acid aqueous solution, for example, and the silicon oxide film 63 on the surface of the silicon substrate 61 is removed (FIG. 5F).

A portion of silicon (boron doped layer 62) that becomes the electrode outlet 26 of the silicon substrate 61 is removed and opened. The removal method is not particularly limited. For example, it can be broken by a pin or the like. Moreover, it can also open by performing dry etching. Thereafter, sealing is performed by pouring, for example, epoxy resin or depositing silicon oxide along the opening of the gap formed between the cavity substrate 20 and each groove portion 11 at the end of the electrode outlet 26. A stopper 25 is formed and sealed, and the gap is blocked from the outside air (FIG. 5G). Here, although not particularly illustrated, for example, a silicon oxide film for protecting the liquid may be formed on the upper surface of the cavity substrate 20 by plasma CVD using TEOS, for example.

When the sealing is completed, for example, a mask having an opening at a portion to be the common electrode terminal 27 is attached to the surface of the bonding substrate on the silicon substrate 61 side. Then, for example, sputtering is performed using platinum (Pt) as a target to form the common electrode terminal 27. Then, the above-described nozzle substrate 30 manufactured in a separate process is bonded to the cavity substrate 2 of the bonded substrate by using, for example, an epoxy adhesive.
Bonding is performed from the 0 side and bonded (FIG. 5H). Then, dicing is performed along the dicing line, and cutting into individual droplet discharge heads is completed.

As described above, according to the first embodiment, when the nozzle substrate 30 is manufactured, a liquid material such as SOG or amorphous fluororesin is applied to the surface on which the concave portion to be the nozzle 31 is formed, and is solidified to be applied. Since the wet etching is performed after forming, for example, even if particles remain before the wet etching, by covering with the coating film 54, the intrusion of the etchant into the recess that becomes the nozzle 31 is surely prevented. The nozzle 31 can be formed precisely. Therefore, it is possible to obtain the nozzle substrate 30 with high discharge performance, and it is possible to increase the yield. At this time, since the silicon oxide film 53 is formed as a resist in advance, the entire substrate can be protected. Further, by using SOG or amorphous fluororesin as the liquid material, protection from an etchant (especially an alkaline aqueous solution such as KOH or TMAH) can be reliably performed.

Embodiment 2. FIG.
In the above-described embodiment, the silicon oxide film 53 is formed on the entire surface, and further, the liquid film is applied to form the coating film 54 on the surface on which the concave portion to be the nozzle 31 is formed. It is not limited. For example, CVD is provided on the surface on which the concave portion to be the nozzle 31 is formed.
A silicon oxide film 53 may be formed by, for example, and a coating film 54 may be formed on the surface where the concave portion to be the nozzle 31 is formed.

Embodiment 3 FIG.
In the above-described embodiment, the nozzle 31 having a two-stage configuration including the first nozzle 31A and the second nozzle 31B.
However, it is not limited to this. In order to improve straightness and improve the discharge performance, three or more stages of nozzles may be configured or may be tapered.

Further, the droplet discharge head in the above-described embodiment includes the electrode substrate 10 and the cavity substrate 2.
Although the three substrates 0 and the nozzle substrate 30 are laminated, the present invention is not limited to this. For example, in order to increase the volume of the reservoir 24, the present invention can also be applied to a droplet discharge head having a configuration in which a recess serving as the reservoir 24 is formed on an independent substrate and four substrates are stacked.

In the above-described embodiment, the liquid droplet ejection head that pressurizes the liquid by displacing the vibration plate 22 by the electrostatic force generated between the vibration plate 22 and the individual electrode 12A and ejects the liquid droplets from the nozzle 31 has been described. . The present invention is not limited to this. For example, generating gas
The present invention can also be applied to a droplet discharge head using another pressing method such as using a piezoelectric element.

Embodiment 4 FIG.
FIG. 6 is an external view of a droplet discharge apparatus using the droplet discharge head manufactured in the above embodiment. FIG. 7 is a diagram illustrating an example of main constituent means of the droplet discharge device. 6 and 7 is intended for printing by a droplet discharge method (inkjet method). Further, it is a so-called serial type device. In FIG. 12, a drum 101 that supports a print paper 110 that is a substrate to be printed and a droplet discharge head 102 that discharges ink to the print paper 110 and performs recording are mainly configured. Although not shown, there is an ink supply means for supplying ink to the droplet discharge head 102. The print paper 110 is held by being pressed against the drum 101 by a paper press roller 103 provided parallel to the axial direction of the drum 101. A feed screw 104 is provided parallel to the axial direction of the drum 101, and the droplet discharge head 102 is held. As the feed screw 104 rotates, the droplet discharge head 102 moves in the axial direction of the drum 101.

On the other hand, the drum 101 is rotationally driven by a motor 106 via a belt 105 or the like.
The print control means 107 also feeds the feed screw 104 based on the print data and the control signal.
The motor 106 is driven, and although not shown here, the oscillation drive circuit is driven to vibrate the vibration plate 22 to perform printing on the print paper 110 while performing control.

Here, the liquid is ejected onto the print paper 110 as ink, 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. Moreover, let the droplet discharge head be a dispenser,
In the case of use for the discharge to a substrate that becomes a microarray of biomolecules, DNA (Deoxyr
A liquid containing a probe such as ibo Nucleic Acids: deoxyribonucleic acid) or other nucleic acids (for example, Ribo Nucleic Acid: ribonucleic acid, Peptide Nucleic Acids: peptide nucleic acid) may be discharged. In addition, it can also be used for discharging dyes such as cloth.

2 is an exploded view of a droplet discharge head according to Embodiment 1. FIG. It is sectional drawing of a droplet discharge head. FIG. 6 is a process diagram (part 1) illustrating the production of the nozzle substrate according to the first embodiment. FIG. 6 is a process diagram (part 2) illustrating the production of the nozzle substrate according to the first embodiment. It is a figure which shows the manufacturing process of a droplet discharge head. 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

10 electrode substrate, 11 groove portion, 12 electrode portion, 12A individual electrode, 12B lead portion,
12C terminal portion, 13 liquid supply port, 20 cavity substrate, 21 discharge chamber, 22 diaphragm, 23 insulating film, 24 reservoir, 25 sealing material, 26 electrode outlet, 27 common electrode terminal, 30 nozzle substrate, 31 nozzle, 31A First nozzle, 31A-1 Nozzle outlet, 31B Second nozzle, 31B-1 Nozzle supply port, 32 Diaphragm, 33 Orifice, 34 Recess, 41 Oscillator circuit, 42 Wiring, 51 Silicon substrate, 52, 53
55, silicon oxide film, 54 coating film, 61 silicon substrate, 62 boron doped layer,
63 silicon oxide film, 100 printer, 101 drum, 102 droplet discharge head,
103 Paper pressure roller, 104 Feed screw, 105 Belt, 106 Motor, 107
Print control means, 110 print paper.

Claims (9)

Opening the nozzle supply port from one side of the silicon substrate and forming a recess to be a nozzle;
Applying a liquid material and forming a film covering a surface on which the concave portion to be the nozzle is formed;
A step of forming a discharge port of the nozzle by performing anisotropic wet etching and penetrating the recess from a surface opposite to the surface on which the recess serving as the nozzle is formed. Production method. 2. The method of manufacturing a nozzle substrate according to claim 1, wherein a silicon oxide film is formed on the silicon substrate before the liquid material is applied to the surface on which the concave portion is formed. The liquid material is SOG or amorphous fluororesin.
Or the manufacturing method of the nozzle substrate of 2. The method of manufacturing a nozzle substrate according to claim 1, wherein anisotropic wet etching of the silicon substrate is performed using an alkaline aqueous solution. The nozzle substrate manufacturing method according to any one of claims 1 to 4, wherein a nozzle having a tapered shape or a stepped shape is formed so that the discharge port has a smaller diameter than the supply port. A nozzle substrate manufactured by the method according to claim 1;
A liquid comprising: a step of bonding a flow path for supplying a liquid to the nozzle of the nozzle substrate and a substrate provided with a pressurizing means for pressurizing the liquid to a part of the flow path. A method for manufacturing 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 6. A droplet discharge head manufactured by the method for manufacturing a droplet discharge head according to claim 6.   A liquid droplet ejection apparatus, comprising the liquid droplet ejection head according to claim 8.

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