JP4138421B2 - Droplet discharge head - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention relates to an inorganic electret actuatorUsedDroplet discharge headToRelated.
[0002]
[Prior art]
Micro actuators in various micro devices such as inkjet heads and other liquid ejection heads, micro pumps, micro light modulation devices, optical devices such as optical switches, micro switches (micro relays), micro flow meters, pressure sensors, micro motors, etc. Is used.
[0003]
For example, in an inkjet head used in an inkjet recording apparatus used as an image recording apparatus (image forming apparatus) such as a printer, a facsimile, a copying apparatus, or a plotter, a diaphragm is used as an actuator unit that generates energy for pressurizing ink in the ink flow path. A piezoelectric actuator such as a piezoelectric element that deforms the electrode or an electrostatic actuator is used.
[0004]
[Problems to be solved by the invention]
By the way, as an actuator capable of performing mechanical drive, there are a piezoelectric actuator mainly composed of PZT as described above and an electrostatic actuator using an electrostatic force. The former piezoelectric actuator is made of PZT containing lead. The latter electrostatic actuator has a problem that the driving force that can be generated is not so large.
[0005]
  The present invention has been made in view of the above problems, and is an inorganic electret actuator.Enables fine division drive with reduced mutual interference usingDroplet discharge headDoThe purpose is to provide.
[0006]
[Means for Solving the Problems]
  To solve the above problem,The droplet discharge head according to the present invention is
  In a droplet discharge head for discharging droplets,
  A lead-free inorganic electret actuator is formed by forming an electret layer and an electrode obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electron polarization on the diaphragm of the droplet discharge head as an actuator that generates pressure for ejecting the droplet. Configure
  The vibration plate has a rigidity of 5000 to 12000 kg / mm. ² And the thickness of the diaphragm is not more than the thickness of the electret layer and the electrode, and the thickness of the electret layer is not more than 1/5 with respect to the width of the electrode.
The configuration.
[0007]
  The droplet discharge head according to the present invention is
  In a droplet discharge head for discharging droplets,
  A lead-free inorganic electret actuator is formed by forming an electret layer and an electrode obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electron polarization on the diaphragm of the droplet discharge head as an actuator that generates pressure for ejecting the droplet. Configure
  The vibration plate has a rigidity of 5000 to 12000 kg / mm. ² And the film thickness of the diaphragm is equal to or less than the thickness of the electret layer and the electrode, and a groove is formed to divide the electret layer into a plurality of actuator parts to correspond to the groove part. The thickness of the electret layer to be ½ or less of the thickness of the electret layer
The configuration.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
An embodiment of an inorganic electret actuator according to the invention of claim 1 will be described with reference to FIG.
The inorganic electret actuator includes an electret layer 1 obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electronic polarization, and electrodes 2 and 3 are provided on both sides of the electret layer 1.
[0039]
Inorganic materials are cationic, negative ionic materials, or anodic or negative molecular groups, or ionic elements or atomic groups with different electronegativity are crystallized to give an electric field and orientation polarization. The electret layer 1 is formed by ion polarization and electron polarization. By applying a rectangular wave or an alternating voltage between the electrodes 2 and 3 of the electret layer 1, monomorph vibration or monomorph mechanical drive occurs as a whole.
[0040]
An example of the manufacturing process of such an inorganic electret actuator will be described with reference to FIGS.
First, as shown in FIG. 2, for example, 2MgO · 2Al of cordierite₂O_Three・ 5SiO₂La of complex powder (average particle size 0.5 to 3 μm) and fine powder (average particle size 0.5 to 3 μm)₂O_ThreeA green sheet 11 having a thickness of 50 μm is formed while supplying a material 12 mixed with 0.5 to 1 wt% onto a belt 13 and applying pressure with a press roller 14 while regulating the layer thickness. A cover is formed on the green sheet 11. A green sheet member as shown in FIG. 3A is obtained by supplying the sheet 15 and applying pressure by the pressure roller 16.
[0041]
Then, the green sheet 11 is dehydrated as shown in FIG. 3 (b), primary firing is performed at 400 to 500 ° C. as shown in FIG. 3 (b), and further, as shown in FIG. When fired at 850-1200 ° C., high rigidity (8000-15000 kg / mm²The material 21 having a large crystal distortion is obtained. This material 21 has a mixed composition of crystalline and amorphous.
[0042]
Thereafter, metal electrodes 2 and 3 are attached to both surfaces of the material 11 as shown in FIG. 5E, and are placed in the atmosphere at 450 ° C. in the atmosphere as shown in FIG. And held for 1 hour, and then, as shown in the same (g), it is cooled down with the DC 300 V electric field applied and left to reach room temperature. As a result, as shown in FIG. 6H, orientation and polarization occur, the crystal portion is maintained with a large strain maintained, and an electret layer 1 converted to an inorganic electret with a large internal polarization is obtained.
[0043]
Here, the basic structure of a device using this inorganic electret actuator is formed by, for example, a deformable member (hereinafter also referred to as “vibrating plate”) made of a conductive material or an insulating material coated with an electrode material. Then, this diaphragm is used as the lower electrode 3, and the inorganic electrode paste or sol-gel is screen printed or metal mask printed on the lower electrode 3 to form an inorganic oxide under sintering conditions. Then, the upper electrode is formed and sintered by printing a metal paste at the time of metal mask printing or after or before being divided into target elements by dry or wet etching. Voltage application and heating are simultaneously performed on the upper and lower electrodes 2 and 3 to form inorganic electrets.
[0044]
In this way, by configuring the inorganic electret actuator to include an electret layer in which an inorganic material is oriented, ion-polarized, and electronically polarized, a lead-free novel actuator having high mechanical strength can be obtained.
[0045]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 2 will be described.
Here, the inorganic material includes a ferroelectric, a dielectric, or a solid electrolyte material, and further includes these particle-oriented ceramics. Specific materials include ZrTiO_Four-SnO₂TiO₂, Fe₂O_Three-NiO, Zn₂TiO₂ZnNiTiO_FourZnFe₂O_Four, K₂OAl₂O₃-SiO₂, CaOAl₂O₃, BaTiO₃, Al₂O₃TiO₂, MgOAl₂O₃There are many polarizable inorganic materials.
[0046]
Moreover, ionization and orientation polarization by a polyvalent atomic group are possible by adding a transition metal system. As a crystal structure, a spinel structure, a perovskite structure, or a sintered body is partially crystallized, and a cube, a rectangular parallelepiped, a rhombohedral, a rhombohedral, and the like exist.
[0047]
The sintering temperature depends on the combination and composition ratio of the materials, the starting material of the raw material, and the particle dependency of the material. Although it is about 200 ° C. to 1200 ° C., good results are usually obtained at 300 ° C. to 600 ° C. Although polarization inversion occurs due to hygroscopicity or strong electric field due to applied voltage, functional deterioration occurs. Under the atmosphere control conditions in this example, the material is dehydrated and in a high oxide state, and the surface electrode metal film protection ensures reliability. The lifetime is satisfied.
[0048]
As a process, it is necessary to form a strain in a part of these crystals, but a film thickness of 1 μm to 300 μm 1 μm, a heating temperature of 300 ° C. to 400 ° C., and an applied voltage of DC 50 V to 500 V are sufficient.
[0049]
Particle oriented ceramics are obtained by first sintering sintered ionic anisotropic fine powders, giving high-pressure pressing directionality, and then performing secondary pressure sintering crystallization to obtain oriented ceramics. And become polarized.
[0050]
Here again, the basic structure of a device using this inorganic electret actuator is, for example, that a diaphragm is formed of a conductive material or an insulating material with an electrode material coated on it, and this is used as the lower electrode. The inorganic material paste or sol-gel is screen printed or metal mask printed, and an inorganic oxide is formed under sintering conditions. Then, after metal mask printing or after dividing into target elements by dry or wet etching, an upper electrode is formed and sintered by printing metal paste. Voltage application and heating are simultaneously performed on the upper and lower electrodes to form inorganic electrets.
[0051]
As described above, since the inorganic material includes a ferroelectric material, a dielectric material, or a solid electrolyte material, since the material itself has a dipole moment and has a polarization orientation, a large amount of displacement can be obtained.
[0052]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 3 will be described.
Here, a target metal ion is selectively implanted into an inorganic material by an ion implantation apparatus to form a composition.
[0053]
In general, many organic materials are caused by corona discharge. As for organic resin materials, defects are generated in the crystal structure by electron implantation or ion implantation on the surface of various blended resins such as fluorine resin, nylon (registered trademark) 11, etc. Polarization is performed.
[0054]
In contrast, in the case of inorganic materials, the surface thermal oxide film SiO of the silicon wafer₂An electret layer can be formed by irradiating an electron beam to (crystalline silicon oxide film), generating lattice defects, and forming a charge trap layer. However, an inorganic material has little crystal distortion due to electron implantation and almost no effect.
[0055]
Therefore, here, metal ions are implanted under reduced pressure. The manufacturing process of such an electret layer is demonstrated with reference to FIG.
First, when accelerating ions such as B, Sb, P, Ti, Bi, W, and Mn are implanted into the composite oxide 31 as shown in FIG. As shown in c), ions enter from the surface of the composite oxide 31 to about 100 to 3000 kg, but here, only the crystal distortion that is not ionized in a mixed state of metal.
[0056]
Furthermore, as shown in FIG. 4D, the metal ions reach 0.5 to 10 μm and are ionized by performing the sintering diffusion treatment (heat diffusion treatment). Thereby, the phase effect of crystal distortion and an ionic effect can be exhibited. And as shown to the figure (e), the electrodes 2 and 3 are attached and electret-ized and the electret layer 1 is formed. In this case, a large ion polarization, charge polarization, and orientation polarization can be obtained.
[0057]
In this way, by adopting a composition in which the target metal ions are selectively implanted into the inorganic material, the ion orientation and the polarization are increased by increasing the crystal distortion and composing the introduced multivalent ions.
[0058]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 4 will be described.
Here, the inorganic material is a metal oxide (TiO₂, NiO, Al₂O₃, Fe₂O₃, MnO₂, Co₂O3 / CoO, Sn₂O₃/ SnO, ZnO, etc.) and alkaline earth compound oxides (BaO, K)₂O, CaO, MgO, etc.) and ZrTiO containing ferroelectrics, dielectrics, or solid electrolyte materials₄-SnO₂TiO₂, Fe₂O₃-NiO, Zn₂TiO₂In addition, ZnNiTiO₄ZnFe₂O₄, K₂OAl₂O₃-SiO₂, CaOAl₂O₃, BaTiO₃, Al₂O₃TiO₂, MgOAl₂O₃It is a mixed composition of polarizable inorganic materials such as.
[0059]
In particular, a compound of an alkaline earth element is a material having an element ion group as a cation and another inorganic material as a negative ion, a large crystallinity, and a high ion orientation. A highly ionic material can be obtained by controlling the redox atmosphere during firing of the composite oxide.
[0060]
The concept of this embodiment is shown in FIG. The example in the figure is an example of polarization based on the negative degree of ion groups, and orientation and polarization easily occur. In fact, Mg₂Al₂O₄And K₂SiO₃, BaFe₂O₄Substances such as complex salts are polarized at high temperatures and electric fields.
[0061]
In this manner, by setting the inorganic material to include a metal oxide or an alkaline earth metal oxide, ion and charge polarization can be increased.
[0062]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 5 will be described.
ZrTiO₄-SnO₂TiO₂, Fe₂O₃-NiO, Zn₂TiO₂In addition, ZnNiTiO₄ZnFe₂O₄, K₂OAl₂O₃-SiO₂, CaOAl₂O₃, BaTiO₃, Al₂O₃TiO₂, MgOAl₂O₃Polarizable inorganic materials such as non-metallic elements and SiO₂, B₂O₃, P₂O₅, Sb2O5, Bi2O3) and further transition element oxides (V2O5, Cr₂O₃, CuO, Y₂O₃, Zr₂O₃, Nb₂O₃, Mo₂O₃, PD₂O₃, La₂O₃The composite oxide in which etc. are mixed can be easily controlled in valence depending on the firing state and atmosphere of the composite oxide containing the transition element. This can control the magnitude of crystal distortion as a result.
[0063]
A conceptual diagram of this embodiment is shown in FIG. Mixed oxides of inorganic dielectrics, polyvalent non-metallic elements, and transition elements are easily baked, especially because polyvalent atoms and transition elements have a low second ionization potential. , Orientation polarization occurs.
[0064]
As described above, by adopting a structure in which the inorganic material is a composite oxide including a transition metal oxide, unbound ions can be held in the crystal of the polyvalent element, and a large ionic polarization can be obtained.
[0065]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 6 will be described.
The inorganic material can be formed by the following method.
For example, a vapor deposition method can be used. In this case, as shown in FIG. 7, for example, as shown in FIG. 7, a plasma CVD apparatus is used, for example, in a chamber 42 holding a substrate 41 constituting a base electrode by decompressing and heating an organic metal or chloride having a high sublimation property. And is brought into contact with plasma or an oxidation reaction gas to cause vapor phase growth. In the figure, 43 is a nozzle, 44 is an anode, 45 is a cathode, 46 is a motor, 47 is a heater, and 48 is a sliding contact. An outline of the parallel plate electrode type plasma CVD apparatus is shown in FIG.
[0066]
Alternatively, a vapor deposition method can be used. In this case, the target inorganic material or metal is heated and sublimated, an oxidizing gas is introduced into the chamber, and a film is formed by vapor deposition.
Furthermore, in the sputtering method, the metal material is a DC power source and a sputtering gas (Ar, He, N2 and O₂The inorganic material having no electrical conductivity can be RF-sputtered with the same sputtering gas using a high-frequency power source.
[0067]
The CVD apparatus and the sputtering apparatus are suitable for forming a thin film, and the film growth is about 10 to 300 cm / min. In addition, the film can be easily formed while the crystal is grown by heating the substrate.
[0068]
When forming a film using any of these methods, a single layer or multiple layers are formed according to the purpose, and substrate heating and reaction gas are introduced at the time of film formation to form oxides or nitrides by plasma reaction. And control the crystallinity and amorphousness.
[0069]
In this case, since the thin film to be formed is flat, the upper electrode is then formed by a vapor deposition method or a photolithography method to form an inorganic electret layer by heating and an electric field.
[0070]
In addition, since the polarization effect is large due to the thin film, when the elements are made into multiple elements as an actuator, the mutual interference between the elements is small without dividing the elements only by individualizing the upper electrode (the electrode 2). This division step is unnecessary, and fine division is possible.
[0071]
In this way, an inorganic material is deposited on a substrate by vapor deposition or vapor deposition, and the substrate is heated and a reaction gas is introduced at the time of film formation to form an oxide or nitride to form a crystal. By forming the electret layer by controlling the property or the amorphous property, the crystallinity or the amorphous property can be easily controlled.
[0072]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 7 will be described.
Here, the inorganic material is formed into a film by electrodeposition or vapor deposition, and this is anodized. Anodization oxidizes with anions with an electrode reaction. For this reason, the site portion where the electrode reacts with ions simultaneously with the formation of the oxide becomes a hole state, and the oxide becomes a porous state. As an example, the anodic oxidation product of metallic Al is well known.
[0073]
Oxide is inorganic acid used (hydrochloric acid, sulfuric acid, nitric acid, perchloric acid), inorganic acid and organic acid (formic acid, acetic acid, oxalic acid, oxalic acid), pH 1-6, the porous size in the oxide film is 50Å-3μm It can be controlled within a range. The thickness of the oxide can be regulated by controlling the voltage of the electrolysis current in the anodic oxidation reaction. In addition, metal ions necessary for polarization are added in the anodic oxidation step, and these ions are electrophoretically deposited on the oxide porous pores and taken into the oxide. A flat thin film of material is formed, and then an upper electrode is formed by vapor deposition or photolithography, and an inorganic electret layer is formed by heating and an electric field.
[0074]
In addition, since the polarization effect is large due to the thin film, when the actuator is made into multiple elements, the mutual interference between the elements is small even if the elements are not divided, only by individualizing the upper electrode, and the conventional dividing process is unnecessary. It is. When this is polarized, a large polarization orientation material is obtained.
[0075]
Here, this manufacturing process will be described with reference to FIGS.
As shown in FIG. 9A, on a substrate 55 having an opening 55a, a diaphragm (deformable member) 53 that also serves as a lower electrode having a thickness of about 3 to 100 μm made of a metal material such as Ni—Cr or SUS. As shown in FIG. 2B, a film 56 of Al, Sn, Zn or the like is formed on the diaphragm 53 by a vapor deposition method or an electrodeposition method to a thickness of 3 to 100 μm, for example.
[0076]
Then, as shown in FIG. 10 (c), the diaphragm 53 is set to a positive potential, and a counter electrode serving as a negative electrode such as Pt is opposed to perform an electrochemical reaction in an acid bath, as shown in FIG. A hole 57 is generated in the electrode, and the diaphragm 53 and the counter electrode are electrically connected to each other through the hole 57, and the anion in the acid bath is transferred to perform a chemical reaction to form an anodic oxide film 58.
[0077]
Thereafter, metal ions of transition elements are introduced into the acid bath and electrodeposited into the holes 57. When this is heat-treated (for example, 300 to 500 ° C.), a composite oxide film is obtained. Therefore, as shown in FIG. 4D, an upper electrode 52 to be an individual electrode is formed, and DC 100 to 800 V is applied and heating to 300 to 800 ° C. is performed between the lower electrode and the diaphragm 53. Thus, the composite oxide film is electretized to form the electret layer 51. By applying a voltage between the electrode 52 and the diaphragm 53, monomorph vibration or monomorph mechanical drive can be performed.
[0078]
In this way, an inorganic material is formed by electrodeposition or vapor deposition, anodized, and metal ions are electrodeposited by electrophoresis to polarize and form the electret layer, thereby forming a thin film process and controlling its crystal. Becomes easier.
[0079]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 8 will be described.
Inorganic materials are mechanochemically mixed with metal oxides, alkaline earth metal oxides, or mixed materials thereof with transition metal oxides using a ball mill mixer or mortar mixer. When mixing, an organic solvent (alcohol, polyhydric alcohol, water, additives (PVA, starch) is added and pulverized with stirring particles to form a sol or gel. This is degassed and rolled into a highly viscous mass. It is formed into a sheet (green sheet) by a roller or the like.
[0080]
This is heated or combined with heating and reduced pressure degassing to form a composite oxide, formed on both sides by electrode baking or electrode screen printing, and heated and subjected to electric field treatment to obtain an inorganic electret layer.
[0081]
Here, this manufacturing process will be described with reference to FIGS.
First, as shown in FIG. 11, the sol-gel inorganic material 72 obtained as described above is supplied onto a belt 73 and a green sheet 71 having a required thickness is formed while the layer thickness is regulated by a press roller 74. Then, the cover sheet 75 is supplied onto the green sheet 11, pressed by the press rollers 74 and 76, fed onto the transport belt 77 at the next stage, and cut to an appropriate length by the cutter 78.
[0082]
Next, the green sheet member obtained as described above as shown in FIG. 12A is heated and sintered to form a composite oxide, and electrodes are formed on both sides as shown in FIG. 62 and 63 are formed, subjected to heating and electric field treatment, and electretized to obtain the electret layer 61.
[0083]
The inorganic electret actuator 60 obtained in this way is joined with an adhesive 67 on a vibration plate 64 provided on a substrate 65 having an opening 65a, for example. By applying a voltage between the electrode 62 and the diaphragm 63, monomorph vibration or monomorph mechanical drive can be performed.
[0084]
Thus, an electret layer can be formed in a simple process by forming an inorganic material in a sol or gel state or forming a film into a sheet, and forming an electret layer by using heating or heating together with vacuum degassing. .
[0085]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 9 will be described.
An inorganic material layer is formed, and primary baking and dehydration are performed at a low temperature. At this stage, the material is an oxide with chemically attached water, chemically bound water (hydrate). For example, there are unstable functional groups in which Si—OH, Al—OH, Fe—OH and the like are partially formed.
[0086]
Therefore, in order to perform further appropriate heat treatment on the primary fired body, an inorganic electret layer is formed and at the same time appropriate heating and an electric field are applied, and the inorganic material undergoes orientation polarization, ion polarization, and electronic polarization in the same process. At this time, the chemical composition of the inorganic material is Si—O—Si or Si═O depending on the atmospheric conditions. The dehydration becomes more complete, and the atomic group is greatly influenced by the electric field during the movement of the crystallization atomic group, and a material having a large ionic orientation, charge orientation and polarization orientation can be obtained. This electret material has improved reliability due to large polarization and scientific stabilization.
[0087]
Here, an example of this manufacturing process will be described with reference to FIG.
As shown in FIG. 2A, the inorganic material layer is fired at a low temperature of 300 to 600 ° C. to obtain a primary fired body 85. At this time, the primary fired body 85 is in a state having a hydroxyl group such as Si—OH, Al—OH, or Fe—OH.
[0088]
Thereafter, as shown in FIG. 4B, electrodes 82 and 83 are formed and fired (heated) at 800 to 1200 ° C., and at the same time, a voltage of DC 200 to 400 V is applied to perform electretization. An electret layer 81 is obtained. At this time, by heating, Si—OH becomes K₂SiO₃It becomes a complex salt compound, and is fixed by being oriented and polarized by an electric field.
[0089]
In this way, polarization is facilitated by simultaneously applying orientation polarization, ion polarization, and electronic polarization by forming an electret layer and simultaneously applying heating and an electric field.
[0090]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 10 will be described.
By forming an inorganic material layer and performing an appropriate high-temperature heat treatment, the chemical composition of the inorganic material becomes Si—O—Si or Si═O depending on the atmospheric conditions. Dehydration is more complete, oxide formation is close to the stoichiometric composition, crystallization is progressing, and it is an oxide in a state of less hygroscopicity, deliquescence, moisture adsorption sites, and the like.
[0091]
Then, electrodes are formed on both surfaces, and then, for electretization as a secondary step, further heating and a high electric field are applied to perform orientation polarization, ion polarization, and electronic polarization. Heating and electric field have a mutual effect, and in the case of low heating, a high electric field is required, and vice versa. However, it is essential that the material has a melting point and is below that temperature.
[0092]
Here, an example of this manufacturing process will be described with reference to FIG.
As shown in FIG. 3A, the inorganic material layer is fired at a high temperature at 400 to 1200 ° C. to obtain a primary fired body 95. At this time, the primary fired body 95 is K.₂SiO₃, BaFe₂O₄, K₂Al₂O₄It is in a state where crystallization has progressed.
[0093]
Thereafter, as shown in FIG. 4B, electrodes 92 and 93 are formed, and heating and heating at 600 to 800 ° C. and application of a high voltage (high electric field) of DC 500 to 2 KV are performed for orientation and polarization, and electret The electret layer 91 is obtained by performing (orientation and polarization).
[0094]
As described above, after forming the inorganic material layer, stable polarization can be performed by applying orientation polarization, ion polarization, and electronic polarization by applying heating, an electric field, and a magnetic field.
[0095]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 11 will be described.
Here, heating and electric field treatment are performed in pressurized air at 1 atm or higher or in an oxygen-rich pressurized state with addition of oxygen during electretization. Thereby, the thermal diffusion of oxygen is sufficient, and a compound close to the stoichiometric composition ratio of the high oxide can be obtained.
[0096]
For example, an element having a multivalent valence is Fe₃O₄Are divalent FeO and trivalent Fe₂O₃This complex oxide is not limited by adding this condition.₂O_ThreeNear high crystallinity and high oxide.
[0097]
This is effective for increasing the anionic group's cathodicity. Furthermore, it is a high oxide as well as a high oxide at the same time, has little surface charge diffusion and transfer, has high frequency drive followability, a large electret effect, and good stability. Note that this step is performed in accordance with the description of FIG. 2 and FIG. 3 described in the embodiment of the first aspect of the invention in the heating and electric field application steps of FIG. Since heating and electric field treatment are performed in pressurized air or in an oxygen-rich pressurized state with oxygen addition, detailed description thereof is omitted.
[0098]
In this way, the material can be brought close to the stoichiometric composition by applying heating and an electric field in pressurized air or in an oxygen-rich oxygen-pressurized state during electretization, so that it becomes a peroxide. It is possible to improve reliability and functions.
[0099]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 12 will be described.
Here, at the time of electret treatment, heating and electric field treatment are performed in the atmosphere or oxygen-rich with oxygen addition at normal pressure. As a result, a highly stable oxide with high stability and flexibility in which oxygen diffusion is dense and crystallinity and amorphousness are mixed can be formed.
[0100]
Note that this step is performed in the air or with oxygen added as described above in the heating and electric field application steps of FIG. 3 (f) in accordance with the description of FIGS. 2 and 3 described in the embodiment of the invention of claim 1. Since the heating and electric field treatment are performed under normal pressure, the detailed description thereof is omitted.
[0101]
In this way, by applying heating and an electric field in the atmospheric state or in an oxygen-rich oxygen-enriched atmospheric state during electretization, the crystallinity is high, a high oxide is obtained, and a reproducible function is obtained. .
[0102]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 13 will be described.
Here, heating and electric field treatment are performed in a vacuum or a vacuum degassing state during electretization. As a result, it is possible to obtain a semiconductor material having a low internal resistance due to metal-rich crystallization and a material having a large strain deformation due to a low voltage applied electric field. In addition, the inorganic electret thus obtained can be driven at a low voltage. However, leakage occurs in high voltage driving, and heat generation and power loss occur.
[0103]
Note that this process is performed in accordance with the description of FIG. 2 and FIG. 3 described in the embodiment of the first aspect of the invention in the heating and electric field application processes of FIG. Since heating and electric field treatment are performed in a gas state, detailed description thereof is omitted.
[0104]
Thus, by applying heating and an electric field in a vacuum or reduced pressure degassing state during the electretization treatment, degassing of the reducing atmosphere and impurities and air removal between the molecular grain boundaries are possible, and the crystallinity increases. That is, the attached oxygen and weakly bonded oxygen are released, and the volatile additive is greatly reduced to obtain a complex oxide with high purity, thereby improving densification and crystallinity.
[0105]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 14 will be described.
Here, at the time of the electret treatment for semiconductorization, the inert gas atmosphere is heated and subjected to an electric field treatment in a gas atmosphere such as argon, helium, or nitrogen. As a result, metal materials and inorganic materials are dehydrated, internal element diffused and crystallized in the absence of anion elements, so transition elements are particularly easy to control the valence and have electrical resistance in the semi-moving region. Is obtained.
[0106]
Note that this step is also performed in the inert gas atmosphere as described above in the heating and electric field application steps of FIG. 3 (f) in accordance with the description of FIGS. 2 and 3 described in the embodiment of the invention of claim 1. Since the heating and electric field treatment are performed, detailed description thereof is omitted.
[0107]
In this way, by applying heating and an electric field in an inert gas atmosphere during electretization processing, electrode oxidation disappears or oxidizes even in high-temperature processing and does not increase in resistance, and it is possible to prevent fine growth by preventing oxide grain boundary growth. Crystal lumps and thin grain boundaries (bandries) are obtained, and the crystal ratio is increased.
[0108]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 15 will be described.
Here, during the electretization process, hydrogen, carbon monoxide, or ammonia, alcohol, aromatic gas, ketone gas, or aldehyde gas is added as an inert gas to the inert gas, Heating and electric field treatment are performed in these atmospheres.
As a result, the reducing gas is decomposed and a deoxygenation reaction of radical hydrogen or carbon monoxide occurs. This regulates the amount and controls the deoxygenation forcibly. Furthermore, there is a reducing action, and the inorganic material becomes a semiconductor.
[0109]
Note that this step is also performed in accordance with the description of FIG. 2 and FIG. 3 described in the embodiment of the invention of claim 1, as described above in the heating and electric field application steps of FIG. Since heating and electric field treatment are performed in a gas-added atmosphere, detailed description thereof is omitted.
[0110]
In this way, by applying heating and an electric field in the reducing gas or organic gas addition atmosphere during the electretization treatment, it is possible to control the valence of the polyvalent element of the transition metal element, and increase the crystallinity and distortion. In addition, since the reduction is forced, a mass of fine crystals and a thin grain boundary (bundry) can be obtained by preventing the growth of oxide grain boundaries.
[0111]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 16 will be described.
Here, an inorganic material layer is formed using an inorganic material including a ferroelectric material, a dielectric material, or a solid electrolyte material, for example, using the manufacturing method according to the invention of claim 6, 7 or 8, and then heated. When an orientation electric field, ionic polarization, or electronic polarization is performed by applying an electric field, a sintering aid having a flux effect is added.
[0112]
This is the addition of vitreous, CuO, Bi₂O_Three, PbO, B₂O₃, Sb₂O₅, P₂O₅Or alkaline earth carbonates and nitrates, but for example CaCO₃, BaCO₃, K₂CO₃Or Ca (NO₃)₂, Ba (NO₃)₂, KNO₃Etc. are added at 0.5 to 10 wt%.
[0113]
These are effective as sintering aids for inorganic materials, and can be prevented from being embrittled by lowering the crystallization temperature and containing an amorphous material (glass body), thereby achieving densification and flexibility. This promotes the improvement of the elastic modulus of the material and the development of some flexibility, 8000kg / mm2 ~ 20000kg / mm²Thus, a large driving force as a monomorph actuator can be obtained.
[0114]
The state of the crystal grain boundary in this case is shown in FIG. As shown in FIG. 5A, when no flux agent is added, there are voids (small voids) in the crystal grain boundary portion, and an amorphous body exists in the crystal grain boundary. This amount is controllable.
[0115]
Here, when a flux agent is added, as shown in FIG. 4B, glassy material is formed simultaneously with decomposition, and the material is condensed at the melted portion, thereby preventing the generation of voids. Therefore, low temperature firing becomes possible. Also in this case, an amorphous body exists in the crystal grain boundary, and embrittlement prevention and slight flexibility are exhibited.
[0116]
In this way, after forming the inorganic material layer, by applying a heating and an electric field, and adding a sintering aid having a flux effect when performing orientation polarization, ion polarization, and electronic polarization, a ferroelectric, dielectric In addition, by forming an inorganic material layer containing a solid electrolyte material and adding a sintering aid with a flux effect, it becomes easier to control the crystallinity and the grain boundary gap due to the flux effect, and sintering with good orientation polarization The body is obtained.
[0117]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 17 will be described.
Again, using an inorganic material, including a ferroelectric, dielectric, or solid electrolyte material, for example, using the manufacturing process of the invention of claim 6, 7 or 8 to form an inorganic material layer, followed by heating In the case where orientation polarization, ion polarization, and electronic polarization are performed by applying an electric field, a sintering aid having a flux effect is added.
[0118]
Here, when a sintering aid having a flux (melting) effect is added and heat melting and decomposition are performed, crystallization starts at a temperature at which crystal growth does not occur in the main composite oxide. This is because when the sintering aid is heated and melted and decomposed, ions, radicals, and primary decomposition products are generated, and the chemically unstable part (functional group) on the surface of the composite oxide grain boundary of the main material is the main material. The composite oxide grain boundary surfaces react with each other to grow crystals, or form a composite salt (amorphous) glass body of the constituent material composition of the main material and the sintering aid. Thereby, the main material crystal growth and the amorphous composite oxide are formed. This can form a dense structure with high crystallinity and slight flexibility.
[0119]
Here, the composition ratio depends on the amount of sintering aid to be added and the processing temperature. That is, the range of 80% or more and 95% or less of the specific gravity relative to the composite oxide stoichiometric composition (close-packed) crystal specific gravity of the main material is reliable in terms of crystal strain, elastic modulus, denseness, and flexibility. Large actuators can be obtained.
[0120]
As described above, when the sintering aid is added, the electric field distortion depending on crystallinity is obtained by setting the crystallinity of the generated composite oxide (stoichiometric composition) specific gravity to 80% or more and 95% or less. In addition, the amorphous portion has flexibility, and cracks due to monomorph driving do not occur, and the device has high workability and can form a microfabricated device.
[0121]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 18 will be described.
Again, using an inorganic material, including a ferroelectric, dielectric, or solid electrolyte material, an inorganic material layer is formed using, for example, the manufacturing process of the invention of claim 6, 7 or 8, followed by heating and An electric field is applied to perform orientation polarization, ion polarization, and electronic polarization.
[0122]
Electrode formation on the composite oxide is carried out by depositing the titanium layer as an underlayer with a vapor deposition method or a baking method including frit glass, and reacting with the elements of the composite oxide or the highly diffusible elements of the sintering aid. And ion diffusion of the electrode material is prevented. Furthermore, the adhesion is improved. Thereafter, an electrode is formed of nickel, an alloy thereof, or a noble metal material that is an electrode material. Here, the property that the chemical stability of titanium element is large is used.
[0123]
Here, an example of this actuator will be described with reference to FIG. Electrodes 102 and 103 made of nickel or the like are formed on both sides of the electret layer 101 via titanium (Ti) layers 104 and 104 layers. This titanium metal layer is chemically stable and has good adhesion, and can prevent ion diffusion and reaction of the material.
[0124]
Thus, by adopting a structure in which the electrode layer is formed through the titanium layer with respect to the electret layer, it is possible to prevent ion diffusion from the inorganic material, prevention of alloying, and prevention of oxidation by oxygen diffusion. An electrode can be formed on the electrode material nickel, its alloy, or a noble metal material, and the reliability is improved.
[0125]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 19 will be described.
Again, using an inorganic material, including a ferroelectric, dielectric, or solid electrolyte material, an inorganic material layer is formed using, for example, the manufacturing process of the invention of claim 6, 7 or 8, followed by heating and An electric field is applied to perform orientation polarization, ion polarization, and electronic polarization.
[0126]
The composite oxide electret is effective due to the electric field strength and crystal distortion, and does not require a current. Therefore, when an electrode is formed, an electrode material is formed by a CVD method, a coating method, or an impregnation method with an insulating layer having a large dielectric constant as a base. Thereby, reaction with the element of complex oxide and the element with large diffusibility of sintering auxiliary agent can be prevented, and ion diffusion of electrode material can be prevented. This is particularly effective when the composite oxide is a material having a resistance in the semiconductor region.
[0127]
As described above, the electrode layer is formed through the insulating layer having a dielectric constant of 3 or more with respect to the electret layer, whereby the voltage drop due to the divided voltage of the applied voltage can be reduced and applied. An electric field is efficiently applied to an inorganic material, and an impurity element is blocked by an insulating layer, so that an actuator without electrode damage can be obtained.
[0128]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 20 will be described.
Again, using an inorganic material, including a ferroelectric, dielectric, or solid electrolyte material, an inorganic material layer is formed using, for example, the manufacturing process of the invention of claim 6, 7 or 8, followed by heating and An electric field is applied to perform orientation polarization, ion polarization, and electronic polarization.
[0129]
When forming an electrode, a nitrogen compound such as silicon nitride or aluminum nitride which is an insulating layer is formed as a base layer. Nitride has high chemical stability, high density, and high heat resistance and moisture resistance. In addition, there is a dielectric constant, and there is little drop in electric field potential.
[0130]
As described above, the electrode layer is formed on the electret layer through silicon nitride, aluminum nitride, or other nitrogen compound layers, so that a nitrogen compound close to the stoichiometric composition can be easily formed. It can be formed and its crystal is dense, so it can prevent the diffusion of impurities, prevent the diffusion of ions from inorganic materials, prevent alloying, and also prevent the oxidation by oxygen diffusion, stable characteristics Is obtained.
[0131]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 21 will be described.
Although the inorganic material composite oxide depends on the size of the crystal grains, it can be a multi-element, array, or block, as well as a single drive element. Thereby, it is possible to configure a droplet discharge head such as an inkjet head using a line pressure sensor and a monomorph drive (actuator) element line arrayed one-dimensionally. Further, as a two-dimensional surface pressure sensor, a writing sensor, an input sensor, and the like can be used.
[0132]
In this way, an actuator suitable for the purpose can be configured by making the inorganic electret actuators multi-layered, arrayed, or blocked.
[0133]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 22 will be described.
The film thickness of the inorganic material composite oxide can be widely adjusted to 0.5 μm to 3 μm by a manufacturing method. As a drive element for mechanically driving the monomorph, various methods can be used as a method for making a multi-layer, an array, and a block.
[0134]
For example, when dividing into 50 to 200 dpi by the sand blast method, an appropriate pattern is formed with a dry film resist, and the blast is made of a material having high hardness such as 3 to 8 μm of SiC, a pressure of 2 atm, a flow rate of 3 to 5 m / Process with s. When this method is used, the minimum is the formation of 50 μm elements, but a large number of large-area elements can be manufactured in a short time.
[0135]
In the case of dry etching, although depending on the constituent material of the inorganic material composite oxide, after formation of the resist pattern, sublimation etching is divided by RIE reaction in fluorine, chlorine and bromine. Anisotropy and isotropy are possible depending on conditions. Although this depends on the aspect ratio, an element having a thickness of 10 μm can be produced in the range of 0.5 to 1.
[0136]
In the case of a wet method, an ion dissolution etchant of an inorganic material composite oxide is used. However, it is only isotropic and is a mixture of mineral acids. A 30 μm element is common in mass production.
[0137]
Although the dicing method can be used, the width of the dicing blade is 20 μm, and there is a problem such as chipping, and the driving element is 30 μm.
[0138]
Here, an example of element division by etching will be described with reference to FIG. As shown in FIG. 6A, for example, the electret layer 111 is formed on the diaphragm 113 which also serves as the lower electrode, and as shown in FIG. 5B, the upper electrode 112 is formed on the electret layer 111, Further, a resist 115 is formed.
[0139]
Then, as shown in FIG. 6C, etching is performed with blast, reactive ions, and reaction solution to form a predetermined resist pattern 116, and then etching is performed as shown in FIG. The electret layer 111 is sequentially etched and divided into a plurality of actuator elements 110. Thereafter, the resist pattern 116 is removed as shown in FIG.
[0140]
As described above, the device can be efficiently formed by being multi-layered, arrayed, or blocked by the sandblasting method, the dry etching method, the wet method, or the dicing method.
[0141]
Next, an embodiment of a droplet discharge head according to the invention of claim 23 will be described. Here, an inorganic material composite oxide is arrayed and divided (blocked) to drive a diaphragm of a droplet discharge head such as an inkjet head on-demand, and droplets are ejected from corresponding nozzles. it can. The diaphragm is driven by a monomorph with an inorganic material composite oxide electret to eject droplets.
[0142]
A configuration example of an ink jet head which is such a droplet discharge head will be described with reference to FIGS.
A liquid chamber 124 is formed by joining a flow path forming member 121 made of a porous body and a diaphragm 123, and a nozzle forming member 126 having a nozzle 125 communicating with the liquid chamber 124 is joined to the flow path forming member 121, Further, a common liquid chamber 127 for supplying ink to the plurality of liquid chambers 124 and a supply member 129 having an ink supply port 128 from the outside to the common liquid chamber 127 are joined.
[0143]
An electret actuator 130 having the diaphragm 123 as a lower electrode is provided on the diaphragm 123. Here, the electret layer 131 and the electrode 132 of this electret actuator 130 are divided | segmented independently corresponding to each liquid chamber 124, respectively, and the diaphragm 123 is set as the structure used as a common electrode without dividing | segmenting.
[0144]
In this inkjet head, ink is supplied from the common liquid chamber 127 to the liquid chamber 124 through the porous member of the flow path forming member 121, and the diaphragm 123 pressurizes the ink in the liquid chamber 124 by driving the electret actuator 130 monomorphically. Ink droplets are ejected from the nozzle 125 while deforming in the direction.
[0145]
As described above, by configuring the droplet discharge head using the inorganic electret actuator according to the present invention, it is possible to configure a droplet discharge head including an actuator that performs a novel mechanical drive.
[0146]
Next, an embodiment of an optical device according to the invention of claim 24 will be described.
Here, an inorganic material electret actuator is provided corresponding to the optical mirror surface that reflects light, and the optical mirror surface is deformed by mechanically driving this actuator, and light bending is performed corresponding to each drive element. Can be made.
[0147]
A metal electrode film serving as a common electrode is formed on an organic film or a thin film inorganic material, and an electret material is formed thereon. In this case, when a low temperature process is selected, a sol-gel containing fine crystal nuclei is applied or formed by a squeegee method. This is heated and dehydrated, and further, an electrode is formed by screen printing, metal mask vapor deposition, or the like, and sintered at an electric field of DC 300 V and heating at 250 ° C. Each monomorph drive element can be easily driven by forming a slit between adjacent elements. The optical mirror surface can be produced by vapor deposition, electrodeposition, or the like.
[0148]
An example of this optical device will be described with reference to FIGS.
In this optical device, a vibration plate (deformable member) 153 which is a lower electrode and serves as a common electrode of each actuator is provided on a substrate 155 having an opening 155a, and an electret layer 151 and individual electrodes 152 are provided on the vibration plate 153. The formed electret actuator 150 is provided. An optical mirror surface 156 is formed on the surface of the diaphragm 123 on the opening 155a side by vapor deposition or electrodeposition.
[0149]
20A shows an example in which the electret actuator 150 is arranged so as to be biased with respect to the opening 155a, and FIG. 20B shows an example in which the electret actuator 150 is arranged at a substantially central portion of the opening 155a.
[0150]
In this optical device, since the optical mirror surface 156 is a flat surface when the electret actuator 150 is not driven, the incident light 158 is reflected at the same incident angle. On the other hand, when the electret actuator 150 is driven, the optical mirror surface 156 is deformed as shown in the phantom line and becomes a convex mirror, so that the incident light 158 becomes scattered light.
[0151]
Thus, by configuring an optical device using the inorganic electret actuator according to the present invention, an optical device including an actuator that performs a novel mechanical drive can be configured.
[0152]
Next, an embodiment of an optical device according to the invention of claim 25 will be described.
Here, a thin film formation method is used to maintain the optical smooth surface of the base electrode, to form a drive element composed of an inorganic electret actuator, and to divide the divided drive electrode surface optically with the individual electrode surface of each element maintaining the base smooth surface. As a mirror, an optical device for bending light corresponding to each driving element is obtained.
[0153]
An example of this optical device will be described with reference to FIG.
As shown in FIG. 2A, this optical device has a silicon oxide (SiO 2) on a silicon wafer 165.₂) A film 166 is formed to a thickness of 2 to 5 μm, and a base electrode 163 is formed on the SiO 2 film 166 using Pt, Au, Ni—Cr or the like.
[0154]
Then, an electret layer 161 is formed on the electrode 163 as shown in FIG. 4B, and a drive electrode 162 is formed on the electret layer 161 with Al, Ag, etc. as shown in FIG. Then, the inorganic electret actuator 160 is formed. The surface of the drive electrode 162 is an optical mirror surface 167.
[0155]
Thereafter, an opening 165a is formed in the silicon wafer 155 by silicon etching or the like as shown in FIG. At this time, the SiO 2 film 166 serves as an etching stop layer and constitutes a deformable portion (vibrating plate).
[0156]
In this optical device, since the optical mirror surface 167 is a flat surface when the electret actuator 160 is not driven, the incident light 168 is reflected at the same incident angle. On the other hand, when the electret actuator 160 is driven, the optical mirror surface 167 is deformed to be a convex mirror or a concave mirror, so that the incident light 168 becomes scattered light.
[0157]
By configuring the optical device having the electrode surface as an optical mirror in this way, the configuration is simplified.
[0158]
Next, an embodiment of a pressure sensor according to the invention of claim 26 will be described.
When the inorganic electret layer is deformed by external pressure, pyroelectric voltage generation or resistance change occurs due to internal crystal distortion in the electret layer. By detecting this voltage or resistance change, a pressure sensor that displays the external pressure as an electrical signal based on the gate voltage rise of the switching element or the change in partial pressure can be configured.
[0159]
Next, an embodiment of a pressure sensor according to the invention of claim 27 will be described. A writing sensor and a two-dimensional surface distribution pressure sensor can be configured by making multiple inorganic electrets and forming an in-plane two-dimensional pressure sensor.
[0160]
An example of a writing input sensor using the pressure sensor according to these claims 26 and 27 will be described with reference to FIGS.
In this writing input sensor, an X electrode 173, an electret layer 171 and a Y electrode 172 are formed on a rigid substrate 175 made of an insulator. The X electrode 173 and the Y electrode 172 are arranged in a matrix. The Y electrode 172 is covered with a protective film 176.
[0161]
In this writing input sensor, when the protective film 176 is touched with a pressure pen, the crossed portion of the X electrode 173 and the Y electrode 172 changes the voltage generation or voltage dividing resistance. A corresponding output is obtained.
[0162]
Next, an embodiment of a transmitter according to the invention of claim 28 will be described.
Here, the elastic material (rigidity) and shape of the inorganic material electret structure can be produced freely. The material of the vibrator is not limited to organic materials, but can be made of materials and shapes with high resonance points by bonding inorganic materials, ceramic films, metal films, organic films and inorganic material films, etc. A wide range of oscillators can be configured. With organic electrets, cones and horns with high rigidity are difficult to drive, and high-frequency oscillation cannot be followed, and there is a limit.
[0163]
Next, an embodiment of a droplet discharge head according to the invention of claim 29 will be described. The thin film inorganic material electret can be freely selected to form a film of about 0.5 to 100 μm. Therefore, an inorganic electret actuator suitable for the purpose is prepared, and only individual electrodes for mechanically driving the actuator are divided into a desired size and arrayed. Thereby, without interposing and dividing (blocking) the drive element (the entire actuator), the mutual interference between adjacent bits is reduced, and a droplet discharge head that can obtain stable discharge characteristics can be configured.
[0164]
Here, an example of an inkjet head which is a droplet discharge head will be described with reference to FIG.
In this head, a diaphragm 183 that also serves as a common electrode is formed on the flow path forming member 185, an electret layer 181 is formed on the diaphragm 183, and the further electret layer 181 is divided by each bit. By providing the electrodes 182, a plurality of inorganic electret actuators 180 are provided corresponding to the nozzles 187 of the liquid chambers 186.
[0165]
In this case, since the plurality of inorganic electret actuators 180 have the electret layer 181 and the diaphragm 183 integrated with each other, the head has reduced mutual interference between adjacent bits.
[0166]
Next, an embodiment of a motor according to the invention of claim 30 will be described.
Here, with the inorganic material electret configuration, the appropriate speed of electretization is set in the plane, or the appropriate shape is cut out and set on the rotor of the electrostatic motor, so that the rotation speed matches the frequency by the surrounding phase electric field drive An inorganic electret electrostatic motor having
[0167]
An example of this motor will be described with reference to FIGS.
First, as shown in FIG. 26, the basic configuration of an electret motor includes stators 201A to 201D and a rotor 202 using an electret. Then, similarly to the rotation principle of the dielectric motor shown in FIG. 27, by changing the voltage applied to the stators 201 </ b> A to 201 </ b> D, suction and repulsion occur with the rotor 202, and the rotor 202 rotates.
[0168]
Therefore, since the inorganic material electret layer 200 according to the present invention can be divided into elements without physically dividing the substrate, an electret motor can be configured by using this as a rotor.
[0169]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 31 will be described.
When an inorganic material is flattened and only the element portion is vibrated by applying a voltage only for forming an individual electrode, or when the monomorph is driven as an actuator, the monomorph diaphragm has a rigidity of 5000 to 12000 kg / mm.²When the film thickness is less than or equal to the electret film thickness, the aspect ratio (b / a) with little mutual interference is 1/5 or less, and the mutual interference noise can be ignored is 1/8 or less. . Thereby, it is possible to perform fine division driving with reduced process deletion and mutual interference.
[0170]
For example, as shown in FIGS. 29 and 30, an inorganic electret actuator 210 is used as an actuator for a droplet discharge head, and an electret layer 211 and an electrode 212 are formed on a diaphragm 213 of the droplet discharge head to form an inorganic electret actuator 210. If the thickness of the diaphragm 213 is equal to or less than the thickness of the electret layer 211 and the electrode 212, the thickness of the electret layer 211 is b, and the element width (the width of the drive electrode 212) is b / a is 1/5 or less, preferably 1/8 or less.
[0171]
Next, an embodiment of an inorganic electret actuator according to the invention of claim 32 will be described.
When an inorganic material is flattened to form an electret structure in which orientation polarization, ion polarization, and electron polarization are applied, multi-elements do not completely divide the element, and grooves are formed between sensor elements, using individual electrodes as a mask. Etch or cut groove with equivalent pattern. The depth of the groove is that the rigidity of the monomorph diaphragm is 5000-12000 kg / mm²In this range, the groove thickness of the film thickness and the electret film thickness is formed to be equal to or less. The thickness of the electret layer in the groove portion where the mutual interference due to the electret film thickness between the elements is small is 1/2 or less of the thickness of the electret layer, and the mutual interference noise can be ignored is 1/5 or less. Thereby, it is possible to perform fine division driving with reduced process deletion and mutual interference.
[0172]
For example, as shown in FIG. 31, an inorganic electret actuator is used as an actuator for a droplet discharge head, an electret layer 221 and an electrode 222 are formed on a diaphragm 223, and the electret layer 221 is incompletely divided by grooves 224. When a plurality of inorganic electret actuators 220 are configured, if the thickness of the diaphragm 223 is equal to or less than the thickness of the electret layer 221, the thickness of the electret layer 221 is c and the thickness of the electret layer 221 corresponding to the groove 224 is d. The groove depth is such that d / c is 1/2 or less, preferably 1/5 or less.
[0173]
【The invention's effect】
  As explained above,According to the droplet discharge head according to the present invention,Thus, a droplet discharge head capable of fine division driving with reduced mutual interference can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory cross-sectional view of an inorganic electret actuator according to the invention of claim 1;
FIG. 2 is an explanatory diagram for explaining an example of a manufacturing process of the inorganic electret actuator
FIG. 3 is a cross-sectional explanatory diagram illustrating a process following FIG.
FIG. 4 is an explanatory cross-sectional view for explaining an inorganic electret actuator according to the invention of claim 3 together with its manufacturing process.
FIG. 5 is a conceptual diagram for explaining an inorganic electret actuator according to the invention of claim 4;
FIG. 6 is a conceptual diagram for explaining an inorganic electret actuator according to the invention of claim 5;
FIG. 7 is a schematic explanatory view of a CVD apparatus for explaining a method for manufacturing an inorganic electret actuator according to the invention of claim 6;
FIG. 8 is a schematic explanatory diagram of another example of a CVD apparatus used to explain a method of manufacturing an inorganic electret actuator according to the invention of claim 6;
FIG. 9 is a cross-sectional explanatory diagram for explaining a method for manufacturing an inorganic electret actuator according to the invention of claim 7;
FIG. 10 is a schematic enlarged explanatory view of the main part.
FIG. 11 is an explanatory diagram for explaining a method of manufacturing an inorganic electret actuator according to the invention of claim 8;
12 is a cross-sectional explanatory diagram illustrating a process following FIG.
FIG. 13 is an explanatory diagram for explaining a method of manufacturing an inorganic electret actuator according to the invention of claim 9;
FIG. 14 is an explanatory diagram for explaining a method of manufacturing an inorganic electret actuator according to the invention of claim 10;
FIG. 15 is an explanatory diagram for explaining a method of manufacturing an inorganic electret actuator according to the invention of claim 16;
FIG. 16 is a conceptual diagram for explaining a method for manufacturing an inorganic electret actuator according to the invention of claim 18;
FIG. 17 is an explanatory view for explaining an inorganic electret actuator according to the invention of claim 22 together with its manufacturing process;
FIG. 18 is a cross-sectional explanatory diagram for explaining a droplet discharge head according to the invention of claim 23;
FIG. 19 is also a perspective explanatory view
FIG. 20 is an explanatory cross-sectional view for explaining an optical device according to the invention of claim 24;
FIG. 21 is also a perspective explanatory view
FIG. 22 is an explanatory view for explaining an optical device according to the invention of claim 25 together with its manufacturing process;
FIG. 23 is an explanatory plan view for explaining a writing input sensor as a pressure sensor according to the invention of claim 26;
FIG. 24 is a cross-sectional explanatory view
FIG. 25 is an explanatory diagram for explaining a droplet discharge head according to the invention of claim 29;
FIG. 26 is a diagram illustrating the principle of an electret motor used for explaining the motor according to the invention of claim 20;
FIG. 27 is a diagram illustrating the principle of a dielectric motor.
FIG. 28 is a perspective explanatory view for explaining the rotor by the inorganic electret as well.
FIG. 29 is a perspective explanatory view for explaining a droplet discharge head including an inorganic electret actuator according to the invention of claim 31;
FIG. 30 is a cross-sectional explanatory view
FIG. 31 is an explanatory perspective view for explaining a droplet discharge head including an inorganic electret actuator according to the invention of claim 32;
[Explanation of symbols]
1 ... electret layer, 2, 3 ... electrode

Claims (2)

In a droplet discharge head for discharging droplets,
A lead-free inorganic electret actuator is formed by forming an electret layer and an electrode obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electron polarization on the diaphragm of the droplet discharge head as an actuator that generates pressure for ejecting the droplet. Configure
The diaphragm has a rigidity in the range of 5000 to 12000 kg / mm ² , and the thickness of the diaphragm is equal to or less than the thickness of the electret layer and the electrode, and the thickness of the electret layer with respect to the width of the electrode The droplet discharge head is characterized in that is 1/5 or less . In a droplet discharge head for discharging droplets,
A lead-free inorganic electret actuator is formed by forming an electret layer and an electrode obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electron polarization on the diaphragm of the droplet discharge head as an actuator that generates pressure for ejecting the droplet. Configure
The diaphragm has a rigidity in the range of 5000 to 12000 kg / mm ² , and the thickness of the diaphragm is equal to or less than the thickness of the electret layer and the electrode. A droplet discharge head, characterized in that a groove to be divided is formed, and a thickness of the electret layer corresponding to the groove portion is ½ or less of a thickness of the electret layer .

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