JP2003011359A - Ink jet head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that the drop ejection characteristics are deviated. SOLUTION: A gap spacer part 24 for forming a gap with respect to a diaphragm 15 is provided on a counter electrode 22 and a silicon oxide film 25 containing boron and/or phosphorus is formed on the surface of the gap spacer part 24 and the counter electrode 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and a manufacturing method thereof, and more particularly to an electrostatic ink jet head and a manufacturing method thereof.

[0002]

2. Description of the Related Art An ink jet head used in an ink jet recording apparatus used as an image recording apparatus such as a printer, a facsimile machine, a copying machine, a plotter or an image forming apparatus, has a nozzle for ejecting ink droplets and a liquid chamber communicating with the nozzle. (Also referred to as an ink flow path, a pressure chamber, a discharge chamber, a pressurized liquid chamber, etc.), a diaphragm forming at least a part of the wall surface of the liquid chamber, and a counter electrode facing the diaphragm. In addition, the electrostatic force generated by applying a voltage between the vibrating plate and the counter electrode deforms and displaces the vibrating plate to change the pressure / volume in the liquid chamber to eject ink droplets from the nozzle. Electric type inkjet heads are known.

As such an electrostatic ink jet head, for example, as described in Japanese Patent Laid-Open No. 6-71882, a first substrate made of a silicon substrate having a vibrating plate and a liquid chamber, and a silicon oxide film. A second substrate made of a silicon substrate having a concave portion formed on the bottom surface of the concave portion and a counter electrode formed on the bottom surface of the concave portion, and a third substrate having a nozzle formed thereon are made of Si.
A method is known in which a Si-Si direct bonding method is used and the gap length between the diaphragm and the counter electrode is defined by the step depth of the recess and the counter electrode thickness. Further, the above publication also discloses the use of a diffusion layer in the silicon substrate as an electrode.

[0004]

As in the conventional electrostatic ink jet head described above, a recess is formed in the silicon oxide film of the second substrate so that the gap length between the diaphragm and the counter electrode can be adjusted by the step depth of the recess. When the gap length is large and the electrode thickness is thin relative to the depth of the recess, the accuracy of the gap length is almost determined by the precision of the depth of the recess. If it is made smaller, there is a problem that the gap length variation becomes larger.

In this case, if the electrode thickness is reduced, the gap length variation can be suppressed to a small level, but the resistance of the electrode becomes high, which causes a problem that the drive voltage cannot be increased.

Specifically, the gap length = 1.
In case of 8 μm (each tolerance is 10%), recess depth = 2.0 μm ± 0.2 μm, electrode thickness = 0.2 μm
Gap depth = 1.8 μm when ± 0.02 μm
± 0.22μm, the gap depth variation is ±
It will be 12%. On the other hand, when the gap length is reduced by keeping the electrode thickness as it is, for example, the gap length =
In the case of 0.2 μm (each tolerance is 10%),
Recess depth = 0.4 μm ± 0.04 μm, electrode thickness = 0.
When 2 μm ± 0.02 μm, the gap depth = 0.
The difference is 2 μm ± 0.06 μm, and the variation in the gap depth is ± 30%.

In this case, when the electrode thickness is reduced, for example, when the electrode thickness is 0.02 μm, the gap length = 0.
In the case of 2 μm (each tolerance is 10%), recess depth = 0.4 μm ± 0.04 μm, electrode thickness = 0.02
μm ± 0.002 μm, gap depth = 0.2 μ
The variation of the gap depth can be maintained within ± 12%, and the resistance of the electrode becomes high due to the thin thickness of the electrode.

In this case, as described above, by adopting the structure in which the diffusion layer in the silicon substrate is used as the electrode,
Although the accuracy of the gap does not decrease due to the thickness of the electrode, since the electrode and the substrate are separated by the pn junction, only one side voltage can be applied and the process for ensuring the breakdown voltage becomes complicated. Another problem is that it is difficult to secure the yield of the pn junction when the area of the electrode of the electrostatic inkjet head is relatively large. Further, since the circumference of the vibration chamber (the chamber including the space where the diaphragm is deformed) is not completely sealed, it is necessary to separately seal with a sealing material in order to prevent foreign matter from entering during operation. However, there is a risk that foreign matter may enter the gap during the manufacturing process (until sealing after opening the vibration plate of the pad portion).

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a highly reliable ink jet head in which variations in ink droplet ejection characteristics are reduced.

[0010]

In order to solve the above problems, an ink jet head according to the present invention is provided with a gap spacer portion for forming a gap with a diaphragm on a counter electrode or a counter electrode material. A silicon oxide film containing boron and / or phosphorus is formed on the surface of the portion and the counter electrode.

In the ink jet head according to the present invention, a gap spacer portion for forming a gap with the counter electrode is provided on the diaphragm or the diaphragm material, and the gap spacer portion and the diaphragm surface are made of silicon containing boron and / or phosphorus. An oxide film is formed.

In the ink jet head according to the present invention, a gap spacer portion for forming a gap with the diaphragm is provided on the counter electrode or the counter electrode material, and the gap spacer portion and the counter electrode surface are made of silicon containing boron and / or phosphorus. A laminated film of an oxide film and an insulating film is formed.

In the ink jet head according to the present invention, a gap spacer portion for forming a gap with the counter electrode is provided on the diaphragm or the diaphragm material, and the gap spacer portion and the diaphragm surface are made of silicon containing boron and / or phosphorus. A laminated film of an oxide film and an insulating film is formed.

In these ink jet heads according to the present invention, it is preferable that one of the vibrating plate and the counter electrode is a common electrode and the other is an individual electrode, and the gap spacer portion is formed on the individual electrode side. Further, it is preferable that the diaphragm be an individual electrode.

A method of manufacturing an ink jet head according to the present invention is a method of manufacturing an ink jet head according to the present invention, which comprises a step of forming a material for a gap spacer portion on a diaphragm or a counter electrode, and a gap spacer. After a step of selectively etching a material to be a diaphragm or a counter electrode to form a gap, a silicon oxide film containing boron and / or phosphorus is formed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an inkjet head according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 2 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.

This ink jet head includes a first substrate 1 which is a flow path substrate using a silicon substrate, and a second substrate 2 which is an electrode substrate using a silicon substrate provided on the lower side of the first substrate 1. A nozzle unit 3 provided on the upper side of the first substrate 1. The nozzle unit 3 includes a flow path forming plate 4, a common ink chamber forming plate 5, and a nozzle plate 6, and nozzle holes 7 for ejecting a plurality of ink droplets. A liquid chamber 8 that is an ink flow path through which each nozzle hole 7 communicates, a common ink chamber 10 that communicates with each liquid chamber 8 through a fluid resistance portion 9 that also serves as an ink supply path, and a nozzle hole 7 and a liquid chamber 8. A nozzle communication path 11 and the like that communicate with each other are formed.

The first substrate 1 has a base substrate 12 and an oxide film 1
SOI (Silicon On I) in which the active layer 14 is joined via
The base substrate 12 of this SOI substrate is etched to form the liquid chamber 8 and the diaphragm 15 including the active layer 13 whose side is covered with the oxide film 22 is formed. . Here, a portion of the base substrate 12 where the liquid chamber 8 is not formed serves as a partition 16 between the liquid chambers.

In the first substrate 1, for example, a high-concentration boron layer serving as an etching stop layer is formed by previously injecting boron into a diaphragm to a silicon substrate to form a second substrate 2
After bonding with the side, the concave portion or the like which becomes the liquid chamber 8 is anisotropically etched using an etching solution such as a KOH aqueous solution, and at this time, the high-concentration boron layer serves as an etching stop layer to form the diaphragm 15. Good.

A protective film may be formed on the surface of the diaphragm 15. Particularly, when the diaphragm 15 is formed of a single crystal silicon substrate, a thermal oxide film can be easily formed on the surface by thermally oxidizing the diaphragm. This thermal oxide film is an insulating film having excellent properties such as insulating properties, defects and interface states.

On the other hand, on the second substrate 2, an insulating film 21 made of a silicon oxide film or the like formed by a thermal oxidation method using a single crystal silicon substrate is formed, and the diaphragm 15 is formed on the insulating film 21 in a predetermined manner. The electrode member (electrode material) 23 that forms the counter electrode 22 facing each other with the gap 17 is arranged, and the vibration plate 15 and the counter electrode 22 form the vibration plate 15
It constitutes an electrostatic actuator that deforms the electrostatic force.

Each counter electrode 22 (electrode member 23)
A gap spacer portion 24 made of an HTO film or the like is formed thereon, and a silicon oxide film 25 containing boron and / or phosphorus is formed on the surfaces of the counter electrode 22 and the gap spacer portion 24. The silicon oxide film 25 containing boron and / or phosphorus also serves as a protective film on the surface portion of the counter electrode 22 for preventing electrical short circuit due to contact between the counter electrode 22 and the diaphragm 15.

As the silicon oxide film 25,
Silicon oxide film containing boron (BSG film: Boro-Silicat)
e Glass), a silicon oxide film not containing boron but containing phosphorus (PSG film: Phospho-Silicate Glass), or a silicon oxide film containing boron and phosphorus (BPSG film: BoroPh)
ospho-Silicate Glass) can be used.

The first substrate 1 and the second substrate 2 are directly joined to each other through the silicon oxide film 25 containing boron and / or phosphorus. Since the silicon oxide film 25 containing boron and / or phosphorus exhibits softening property at a low temperature of 1000 ° C. or less, good direct bonding can be achieved by reflowing by heat treatment after forming the silicon oxide film 25. A good surface property can be obtained.

The flow passage forming plate 4 of the nozzle unit 3 has a through hole for forming an ink supply passage (fluid resistance portion) 9 and a through hole for forming a nozzle communication passage 11, and the common ink chamber forming plate 5 has a common ink. Through-hole and nozzle communication path 1 forming chamber 10
Nozzle holes 7 are formed in the nozzle plate 6 and through holes forming No. 1 are formed. Then, the flow path forming plate 4 of the nozzle unit 3 is bonded onto the first substrate 1 with the adhesive 30.

The surface of the nozzle plate 6 is treated to be water repellent. Further, the nozzle unit 3 is provided with an ink supply port (not shown) for supplying ink to the common ink chamber 10 from the outside. Furthermore, the liquid chamber 8 and the diaphragm 1
It is also possible to adopt a structure in which the nozzle plate 6 having nozzle holes formed thereon is joined to the flow path substrate having the holes 5 formed thereon.

In this ink jet head, when a driving voltage is applied between the vibrating plate 15 and the counter electrode 22, the vibrating plate 15 is displaced to the electrode side by the electrostatic force generated between the vibrating plate 15 and the counter electrode 22. The ink is deformed, and accordingly, ink is supplied to the liquid chamber 8 from the common ink chamber 10 through the fluid resistance portion 9. After that, when the voltage is returned to 0, the vibrating plate 15 which is displaced causes the elastic force to return to the original position, so that ink droplets are ejected from the nozzle holes 7.

Here, in this ink jet head, the gap length between the diaphragm 15 and the counter electrode 22 is uniquely determined by the thickness of the gap spacer portion 24, and the thickness of the protective film on the counter electrode 22 is also made of silicon. Since it is uniquely determined by the thickness of the oxide film 25, it is possible to form a highly accurate gap and reduce variations in ink droplet ejection characteristics.

Next, a first embodiment of a manufacturing method according to the present invention for manufacturing this ink jet head will be described with reference to FIG. As shown in FIG. 3A, a silicon wafer is used as the second substrate 2 as a supporting substrate, and an oxide film of about 1.0 μm is formed as the insulating film 21 by thermal oxidation. After that, as the electrode member 23, WSi (thickness 0.20 μm) / poly-Si (thickness 0.15 μm,
A phosphorus-doped) laminated film is formed and separated into individual counter electrodes 22 by photolithography / etching. Then, a gap spacer material 31 (here, an HTO film) for forming the gap spacer portion 24 is formed to a thickness of 0.20 μm.

Here, CMP (Chemical Mechanical)
It is also possible to reduce the surface roughness of the gap spacer material 31 by Polishing). The necessity of the CMP step is determined by the surface roughness of the gap spacer material 31 at this point and the thickness / flowability of the insulating film 25 formed in the subsequent step. In some cases, it may not be necessary. In this embodiment, C
The MP process is omitted.

Then, as shown in FIG.
The gap 17 is formed by the litho / etching process.
The gap spacer material 31 in the part is etched to form a gap.
The up spacer portion 24 is formed. At this time, according to BHF
Wet etch or CHF _Three+ CF_FourDry by etc.
By etching, the gap spacer material 31 is applied to the counter electrode 2
It can be etched selectively with respect to 2. did
Therefore, the gap depth formed at this time is the gap
Thickness of the spacer portion 24 (film of the gap spacer material 31
Thickness).

Thereafter, as shown in FIG. 3C, a silicon oxide film 25 is formed on the surface of the counter electrode 22 and the entire surface of the gap spacer portion 24 by the atmospheric pressure CVD method. Here, a silicon oxide film containing about 4.0 wt% of boron and about 4.5 wt% of phosphorus, a so-called BPSG film, is formed by 0.15 μm.
Depot about. Then, the silicon oxide film 25 is densified at a high temperature in order to reduce surface roughness and discharge gas in the film. Here, it was performed in a nitrogen atmosphere at 1050 ° C. for 60 minutes.

Then, as shown in FIG. 3D, for example, an SOI substrate to be the first substrate 1 for forming the liquid chamber 8, the vibration plate 15 and the like, and a high concentration boron diffusion layer are formed on the second substrate 2. A silicon substrate 32 such as a single crystal silicon substrate is bonded by the steps of hydrophilic treatment, adhesion and heat treatment.

Here, hydrophilization treatment: sulfuric acid + hydrogen peroxide water, water washing, ammonia + hydrogen peroxide water, water washing heat treatment; 1
Bonding was performed at 000 ° C. for 60 minutes in a nitrogen atmosphere.

In this case, since the gap spacer portion 24 is formed on the side of the counter electrode 22 which is an individual electrode,
The alignment accuracy with the diaphragm 15 can be performed so not so severely.

Next, although not shown, the silicon substrate 32 is anisotropically etched with an alkaline aqueous solution (KOH aqueous solution or the like) to form the pressurized liquid chamber 8 and the vibrating plate 15, and the nozzle unit 3 is joined to form an ink jet. The head is completed.

Next, a second embodiment of the ink jet head according to the present invention will be described with reference to FIGS. 3 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 3 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm. In this ink jet head, a gap spacer portion 24 is formed on a vibration plate 15 (base substrate 14 which is a vibration plate material), and the gap spacer 24 and its opening, that is, a portion functioning as the vibration plate 15 (in the gap 17). A silicon oxide film 25 containing boron and / or phosphorus is formed on the surface of the facing portion). In this case, the silicon oxide film 25 also functions as a protective film for the diaphragm 15 and a short-circuit preventing film for the diaphragm 15 and the counter electrode 22. Also,
Although illustration is omitted, it is also possible to form a protective film on the surface of the counter electrode 22.

Even in the case of such a configuration, the diaphragm 15
Since the gap length between the counter electrode 22 and the counter electrode 22 is uniquely determined by the thickness of the gap spacer portion 24, and the thickness of the protective film on the vibration plate 15 is also uniquely determined by the thickness of the silicon oxide film 25, it is highly accurate. A gap can be formed, and variations in ink droplet ejection characteristics are reduced.

Next, a second embodiment of the manufacturing method according to the present invention for manufacturing this ink jet head will be described with reference to FIG. Here, an example in which the diaphragm 15 is formed of a high-concentration boron diffusion layer will be described. First, as shown in FIG. 1A, the crystal plane orientation (1
The silicon wafer which is the single crystal silicon substrate 33 of 10) is used, and the silicon substrate 33 has a boron concentration of 5 × 10 5.
Boron is diffused so as to have a concentration of ¹⁹ / cm ³ or more to form a high-concentration boron diffusion layer 34. Then, the gap spacer portion 2
As the gap spacer material 31 for forming 4, a HTO film, for example, is formed to a thickness of 0.20 μm.

Then, as shown in FIG.
The gap 17 is formed by the litho / etching process.
The gap spacer material 31 in the part is etched to form a gap.
The up spacer portion 24 is formed. At this time, according to BHF
Wet etch or CHF _Three+ CF_FourDry by etc.
By etching, the gap spacer material 31 is moved to the diaphragm 15
(This is the high-concentration boron diffusion layer 34 at this stage.)
Can be selectively etched. According to
The gap depth formed at this time is
Thickness of the sensor portion 24 (thickness of the gap spacer material 31)
Stipulated in.

Thereafter, as shown in FIG. 6C, a silicon oxide film 25 is formed by atmospheric pressure CVD on the surface of the portion of the high-concentration boron diffusion layer 34 to be the vibration plate 15 and the entire surface of the gap spacer portion 24. To do. Here, Boron 4.0w
a silicon oxide film containing about t% and about 4.5 wt% phosphorus,
A so-called BPSG film is deposited by about 0.15 μm. Then, the insulating film 25 is densified at a high temperature in order to reduce surface roughness and discharge gas in the film. Here, 1050 ℃
It was performed in a nitrogen atmosphere for -60 min.

Next, the counter electrode 22 is formed on the silicon substrate 33.
The second substrate 2 on which is formed is directly bonded by the steps of hydrophilic treatment, alignment of the pattern of the gap spacer portion 24 and the pattern of the individual counter electrode 22, adhesion, and heat treatment. The joining conditions were the same as in the first embodiment.
In this case, since the gap spacer portion 24 is formed on the common electrode side (vibration plate 15 side), alignment with the individual electrode 22 is required.

Next, although not shown, the silicon substrate 33 is polished to a predetermined liquid chamber height to obtain an alkaline aqueous solution (KO).
An ink jet head is completed by forming the pressurized liquid chamber 8 and the vibrating plate 15 by anisotropic etching with a H aqueous solution or the like) and joining the nozzle unit 3 to each other.

Next, a third embodiment of the ink jet head according to the present invention will be described with reference to FIGS. 7 and 8. 7 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 8 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm. In this inkjet head, the diaphragm of the first substrate 1 is separated into the individual diaphragms 35, and the gap spacer portions 24 are formed on the individual diaphragms 35, and the gap spacer portions 24 and the openings thereof, that is, the gaps 17 of the individual diaphragms 35. A silicon oxide film 25 containing boron and / or phosphorus is formed on the surface of the portion facing the. The insulating film 25 also functions as a protective film for the individual diaphragm.

In addition, in this embodiment, since the silicon substrate which is a conductive material is used as the second substrate 42, the portion of the second substrate 42 facing the diaphragm 35 functions as the counter electrode 43. When an insulating substrate is used as the second substrate 42, a counter electrode serving as a conductive common electrode may be separately formed on the insulating substrate. In addition, even when a conductive substrate is used, a counter electrode can be separately formed due to resistance and other reasons.

Further, although not shown, a protective film can be formed on the second substrate 42 which also serves as a counter electrode. In particular, the second substrate 4 also serving as the counter electrode as in this example
When a silicon substrate is used for 2, by thermally oxidizing it, it is possible to obtain a thermal oxide film having very excellent characteristics such as insulation, defects and interface states.

Even in the case of such a configuration, the diaphragm 35
The gap length between the counter electrode 43 and the counter electrode 43 is uniquely determined by the thickness of the gap spacer portion 24, and the thickness of the protective film on the vibration plate 35 is also uniquely determined by the thickness of the silicon oxide film 25. A gap can be formed, and variations in ink droplet ejection characteristics are reduced. In addition, the diaphragm 35
Since the individual electrodes are used as the individual electrodes and the counter electrodes are used as the common electrodes, the number of constituent members is reduced, and accordingly, the number of steps is also reduced, so that a lower cost inkjet head is obtained.

Next, a third embodiment of the manufacturing method according to the present invention for manufacturing this ink jet head will be described with reference to FIG. First, as shown in FIG.
A silicon wafer, which is a single crystal silicon substrate 51 having a crystal plane orientation (110), is used as the first substrate 1, a thermal oxide film 52 of about 0.5 μm is formed on the surface of the silicon substrate 51, and the surface of the thermal oxide film 52 is formed. Polysilicon, which is a diaphragm material doped with phosphorus, is deposited to a thickness of about 2.0 μm, and the polysilicon is divided into individual diaphragms 35 by photolithography / etching. Then, the gap spacer portion 24
For example, an HTO film is formed to a thickness of 0.20 μm as the gap spacer material 31 for forming the.

Then, as shown in FIG.
The gap 17 is formed by the litho / etching process.
The gap spacer material 31 in the part is etched to form a gap.
The up spacer portion 24 is formed. At this time, according to BHF
Wet etch or CHF _Three+ CF_FourDry by etc.
By etching, the gap spacer material 31 is moved to the diaphragm 35.
Can be selectively etched with respect to. But
The gap depth formed at this time is
Thickness of the pacer portion 24 (film of gap spacer material 31
Thickness).

Thereafter, as shown in FIG. 7C, a silicon oxide film 25 is formed on the surface of the diaphragm 35 and the entire surface of the gap spacer portion 24 by the atmospheric pressure CVD method. Here, a silicon oxide film containing about 4.0 wt% of boron and about 4.5 wt% of phosphorus, a so-called BPSG film, is formed by 0.15 μm.
Depot about. Then, the insulating film 25 is densified at a high temperature in order to reduce surface roughness and discharge gas in the film. Here, it was performed in a nitrogen atmosphere at 1050 ° C. for 60 minutes.

Then, the second substrate 42, which will be the counter electrode, is directly bonded to the silicon substrate 53 by the steps of hydrophilic treatment, adhesion and heat treatment. The bonding conditions are hydrophilic treatment;
Sulfuric acid + hydrogen peroxide solution, washed with water, ammonia + hydrogen peroxide solution,
Washing with water, heat treatment; 1000 ° C., 60 minutes, nitrogen atmosphere. In this case, since the gap spacer portion 24 is formed on the individual electrode side (vibration plate 35 side), the alignment accuracy with the vibration plate 35 is not so severe.

Next, although not shown in the figure, the silicon substrate 53 is polished to a predetermined liquid chamber height to obtain an alkaline aqueous solution (KO).
An ink jet head is completed by forming the pressurized liquid chamber 8 and the vibrating plate 35 by anisotropic etching with an H aqueous solution or the like) and joining the nozzle unit 3 to each other.

Next, a fourth embodiment of the ink jet head according to the present invention will be described with reference to FIGS. 10 is a cross-sectional explanatory view of the head in the longitudinal direction of the diaphragm, and FIG. 11 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm. In this inkjet head, the gap spacer portion 24 is formed on the electrode 22 (electrode member 23) similarly to the inkjet head of the first embodiment, and the gap spacer portion 24 and the electrode 22 are insulated not containing boron and phosphorus. The silicon oxide film 25 containing boron and / or phosphorus is formed through the film 26.

Here, a silicon nitride film is used as the insulating film 26. Since the silicon nitride film has a higher dielectric constant than the silicon oxide film, it can be driven at a lower voltage. Further, since the silicon nitride film is dense, the electrode protecting effect can be obtained even if the film thickness is comparatively thin.

Although not shown, it is also possible to form a protective film on the surface of the diaphragm 15. In particular, when the diaphragm 15 is a single crystal silicon substrate, thermal oxidation of the single crystal silicon substrate makes it possible to obtain a thermal oxide film having excellent properties such as insulation, defects, and interface states.

By stacking different films in this way, a higher performance ink jet head can be obtained. Then, as in the above-described embodiment, the gap length between the vibration plate 15 and the counter electrode 22 is determined by the gap spacer portion 2.
4 is uniquely determined, and the thickness of the protective film on the counter electrode 22 is also uniquely determined by the thicknesses of the insulating film 26 and the silicon oxide film 25. Therefore, a highly accurate gap can be formed, and the ink droplets can be formed. Variations in ejection characteristics are reduced.

Next, FIG. 12 shows the fourth embodiment of the manufacturing method according to the present invention for manufacturing this ink jet head.
The explanation will also be given with reference to As shown in FIG. 3A, a silicon wafer is used as the second substrate 2 as a supporting substrate,
As the insulating film 21, an oxide film of about 1.0 μm is formed by thermal oxidation. After that, as the electrode member 23, WSi (thickness 0.20 μm) / poly-Si (thickness 0.15 μm,
A phosphorus-doped) laminated film is formed and separated into individual counter electrodes 22 by photolithography / etching. Then, a gap spacer material 31 (here, an HTO film) for forming the gap spacer portion 24 is formed to a thickness of 0.20 μm.

Here, CMP (Chemical Mechanical)
It is also possible to reduce the surface roughness of the gap spacer material 31 by Polishing). The necessity of the CMP step is determined by the surface roughness of the gap spacer material 31 at this point and the thickness / flowability of the insulating film 25 formed in the subsequent step. In some cases, it may not be necessary. In this embodiment, C
The MP process is omitted.

Then, as shown in FIG.
The gap 17 is formed by the litho / etching process.
The gap spacer material 31 in the part is etched to form a gap.
The up spacer portion 24 is formed. At this time, according to BHF
Wet etch or CHF _Three+ CF_FourDry by etc.
By etching, the gap spacer material 31 is applied to the counter electrode 2
It can be etched selectively with respect to 2. did
Therefore, the gap depth formed at this time is the gap
Thickness of the spacer portion 24 (film of the gap spacer material 31
Thickness).

Thereafter, as shown in FIG. 7C, a silicon nitride film as an insulating film 26 is formed on the surface of the counter electrode 22 and the entire surface of the gap spacer portion 24 by the low pressure CVD method to a thickness of about 0.05 μm. A silicon oxide film 25 is formed on the insulating film 26 by atmospheric pressure CVD to a thickness of 0.05 μm. Then, densification is performed at a high temperature in order to reduce the surface roughness and release gas in the film. Here, 10
It was carried out at 50 ° C. for 60 minutes in a nitrogen atmosphere.

Then, as shown in FIG. 7D, for example, an SOI substrate to be the first substrate 1 for forming the liquid chamber 8, the vibration plate 15 and the like, and a high concentration boron diffusion layer are formed on the second substrate 2. A silicon substrate 32 such as a single crystal silicon substrate is bonded by the steps of hydrophilic treatment, adhesion and heat treatment.

Here, hydrophilization treatment: sulfuric acid + hydrogen peroxide water, water washing, ammonia + hydrogen peroxide water, water washing heat treatment; 1
Bonding was performed at 000 ° C. for 60 minutes in a nitrogen atmosphere.

Next, although not shown, the silicon substrate 32 is anisotropically etched with an alkaline aqueous solution (KOH aqueous solution or the like) to form the pressurized liquid chamber 8 and the vibrating plate 15, and the nozzle unit 3 is joined to form an ink jet. The head is completed.

In each of the above-described embodiments, the side shooter type head formed so that the ink droplets are ejected in the displacement direction of the vibration plate has been described. However, the ink droplets are generated in the direction intersecting the displacement direction of the vibration plate. The same applies to an edge shooter type head formed so as to eject ink. The present invention is not limited to ejecting ink droplets, but can be applied to ejecting droplets of liquid resist or the like.

Further, the electrostatic actuator composed of the vibration plate and the electrodes described in the embodiments of the present invention is not limited to the ink jet head, but is also a micro electrostatic pump, a micro relay, an optical switch, a micro switch (micro relay). It can also be used as an actuator for a multi-optical lens.

[0066]

As described above, according to the ink jet head of the present invention, the gap spacer portion forming the gap with the diaphragm is provided on the counter electrode or the counter electrode material, and the gap spacer portion and the counter electrode are provided. Since the silicon oxide film containing boron and / or phosphorus is formed on the surface, the variation in the gap is reduced and the variation in the ink droplet ejection characteristics is reduced.

According to the ink jet head of the present invention, the gap spacer portion for forming the gap with the counter electrode is provided on the diaphragm or the diaphragm material, and the gap spacer portion and the diaphragm surface are filled with boron and / or phosphorus. Since the containing silicon oxide film is formed, the variation in the gap is reduced and the variation in the ink droplet ejection characteristics is also reduced.

According to the ink jet head of the present invention, the gap spacer portion for forming a gap with the diaphragm is provided on the counter electrode or the counter electrode material, and boron and / or phosphorus is provided on the gap spacer portion and the counter electrode surface. Since the laminated film of the silicon oxide film containing and the insulating film is formed,
Variations in the gap are reduced, variations in ink droplet ejection characteristics are reduced, and higher performance is achieved.

According to the ink jet head of the present invention, the gap spacer portion forming the gap with the counter electrode is provided on the diaphragm or the diaphragm material, and the gap spacer portion and the diaphragm surface are filled with boron and / or phosphorus. Since the laminated film of the silicon oxide film containing the insulating film and the insulating film is formed, the variation in the gap is reduced, the variation in the ink droplet ejection characteristics is reduced, and the performance is further improved.

In these ink jet heads according to the present invention, one of the vibrating plate and the counter electrode is used as a common electrode and the other is used as an individual electrode, and a gap spacer portion is formed on the individual electrode side to oppose the vibrating plate. Alignment with the electrodes is not required, and the cost can be reduced. Further, by using the diaphragm as an individual electrode, it is possible to reduce the number of parts and the number of steps, and to reduce the cost.

According to the method of manufacturing an ink jet head of the present invention, the step of forming a material for the gap spacer portion on the diaphragm or the counter electrode, and the material for the gap spacer selectively with the diaphragm or the counter electrode. Since the silicon oxide film containing boron and / or phosphorus is formed after the step of etching to form a gap, the gap spacer portion is selectively etched using the diaphragm or the counter electrode as an etching stop. Therefore, the inkjet head according to the present invention can be manufactured with high accuracy.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view in a longitudinal direction of a diaphragm of an inkjet head according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional explanatory view of the head in the lateral direction of the diaphragm.

FIG. 3 is a cross-sectional explanatory diagram illustrating a method of manufacturing the inkjet head according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional explanatory view in the longitudinal direction of the diaphragm of the inkjet head according to the second embodiment of the present invention.

FIG. 5 is a cross-sectional explanatory view of the same head in the lateral direction of the diaphragm.

FIG. 6 is a cross-sectional explanatory diagram illustrating a method of manufacturing an inkjet head according to a second embodiment of the present invention.

FIG. 7 is an explanatory cross-sectional view in the longitudinal direction of the diaphragm of the inkjet head according to the third embodiment of the present invention.

FIG. 8 is a cross-sectional explanatory view of the same head in the lateral direction of the diaphragm.

FIG. 9 is a cross-sectional explanatory diagram illustrating a method of manufacturing an inkjet head according to a third embodiment of the invention.

FIG. 10 is an explanatory cross-sectional view in the longitudinal direction of the diaphragm of the inkjet head according to the fourth embodiment of the present invention.

FIG. 11 is a cross-sectional explanatory view of the same head in the lateral direction of the diaphragm.

FIG. 12 is a cross-sectional explanatory diagram illustrating a method of manufacturing an inkjet head according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st substrate, 2 ... 2nd substrate, 8 ... Liquid chamber, 15 ... Vibration plate, 17 ... Gap, 21 ... Insulating film, 22 ... Counter electrode,
24 ... Gap spacer part, 25 ... Silicon oxide film, 2
6 ... Insulating film.

Claims (7)

[Claims] 1. A vibrating plate comprising: a nozzle for ejecting ink droplets; a liquid chamber communicating with the nozzle; a vibrating plate forming a wall surface of the liquid chamber; and a counter electrode facing the vibrating plate. In an ink jet head that deforms ink with electrostatic force to eject ink droplets from the nozzles, a gap spacer portion that forms a gap with the diaphragm is provided on the counter electrode or counter electrode material, and the gap spacer portion and the counter electrode An inkjet head comprising a silicon oxide film containing boron and / or phosphorus formed on the electrode surface. 2. A vibrating plate comprising: a nozzle for ejecting ink droplets; a liquid chamber communicating with the nozzle; a vibrating plate forming a wall surface of the liquid chamber; and a counter electrode facing the vibrating plate. In an ink jet head that deforms ink by electrostatic force to eject ink droplets from the nozzles, a gap spacer portion that forms a gap with the counter electrode is provided on the vibration plate or the vibration plate material. An ink jet head, characterized in that a silicon oxide film containing boron and / or phosphorus is formed on the surface of the plate. 3. A vibrating plate comprising: a nozzle for ejecting ink droplets; a liquid chamber communicating with the nozzle; a vibrating plate forming a wall surface of the liquid chamber; and a counter electrode facing the vibrating plate. In an ink jet head that deforms ink with electrostatic force to eject ink droplets from the nozzles, a gap spacer portion that forms a gap with the diaphragm is provided on the counter electrode or counter electrode material, and the gap spacer portion and the counter electrode An inkjet head comprising a laminated film of a silicon oxide film containing boron and / or phosphorus and an insulating film formed on an electrode surface. 4. A vibrating plate comprising: a nozzle for ejecting ink droplets; a liquid chamber communicating with the nozzle; a vibrating plate forming a wall surface of the liquid chamber; and a counter electrode facing the vibrating plate. In an ink jet head that deforms ink by electrostatic force to eject ink droplets from the nozzles, a gap spacer portion that forms a gap with the counter electrode is provided on the vibration plate or the vibration plate material. An inkjet head comprising a laminated film of a silicon oxide film containing boron and / or phosphorus and an insulating film formed on a plate surface. 5. The inkjet head according to claim 1, wherein one of the diaphragm and the counter electrode is a common electrode, and the other is an individual electrode.
An ink jet head having a gap spacer portion formed on the individual electrode side. 6. The inkjet head according to claim 1, wherein the vibrating plate is an individual electrode. 7. The manufacturing method for manufacturing an inkjet head according to claim 1, wherein a step of forming a material for a gap spacer portion on the diaphragm or the counter electrode, and the gap. An inkjet head characterized in that a silicon oxide film containing boron and / or phosphorus is formed after a step of selectively etching a material to be a spacer with the vibration plate or the counter electrode to form a gap. Production method.