JP2004120809A - Inorganic erectret actuator, manufacturing method thereof, liquid droplet injecting head, optical device, pressure sensor, oscillator, and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leadless actuator for a high mechanical driving force. <P>SOLUTION: The inorganic material is crystallized by containing material of positive ionicity or negative ionicity, molecular group of positive polarity and negative polarity, or ion element or atomic group of different electronegativity which is applied with an electric field for orientational polarization, ionic polarization, and electronic polarization to constitute an electret layer 1. Electrodes 2 and 3 are formed on both surfaces of the electret layer 1, respectively. A rectangular wave and an alternating voltage are applied between the electrodes 2 and 3 to cause mono morph oscillation or mono morph mechanical driving as a whole. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to an inorganic electret actuator and a method for manufacturing the same, a droplet discharge head, an optical device, a pressure sensor, an oscillator, and a motor.
[0002]
[Prior art]
Micro actuators are used for various micro devices such as droplet discharge heads such as inkjet heads, micro pumps, micro light modulation devices, optical switches and other optical devices, micro switches (micro relays), micro flow meters, pressure sensors, and micro motors. Is used.
[0003]
For example, in an ink jet head used in an ink jet recording apparatus used as an image recording apparatus (image forming apparatus) such as a printer, a facsimile, a copying apparatus, and a plotter, a diaphragm is used as an actuator for generating energy for pressurizing ink in an ink flow path. For example, a piezoelectric actuator such as a piezoelectric element or an electrostatic actuator that deforms the piezoelectric element is used.
[0004]
[Problems to be solved by the invention]
By the way, as actuators that can perform mechanical driving, there are piezoelectric actuators mainly using PZT as described above and electrostatic actuators using electrostatic force, but PZT including lead is the former piezoelectric actuator. The latter is the main subject, and the latter 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 provides a novel inorganic electret actuator and a method of manufacturing the same, a droplet discharge head including the actuator, a droplet discharge head, an optical device, a pressure sensor, an oscillator, and a motor. The purpose is to do.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an inorganic electret actuator according to claim 1 is configured to include an electret layer obtained by subjecting an inorganic material to orientation polarization, ionic polarization, and electronic polarization.
[0007]
According to a second aspect of the present invention, in the inorganic electret actuator according to the first aspect, the inorganic material includes a ferroelectric material, a dielectric material, or a solid electrolyte material.
[0008]
According to a third aspect of the present invention, there is provided the inorganic electret actuator according to the second aspect, wherein the target metal ions are selectively implanted into the inorganic material to form a composition.
[0009]
According to a fourth aspect of the present invention, in the inorganic electret actuator according to any one of the first to third aspects, the inorganic material includes a metal oxide or an alkaline earth metal oxide.
[0010]
An inorganic electret actuator according to a fifth aspect is the inorganic electret actuator according to any one of the first to fourth aspects, wherein the inorganic material is a composite oxide containing a transition metal oxide.
[0011]
A method for manufacturing an inorganic electret actuator according to claim 6 is the method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein the inorganic material is formed on the substrate by vapor phase growth or vapor deposition. A film was formed, and a substrate was heated and a reaction gas was introduced at the time of film formation to form an oxide or a nitride and control the crystallinity or the amorphousness to form an electret layer.
[0012]
According to a seventh aspect of the present invention, there is provided a method for manufacturing an inorganic electret actuator according to any one of the first to fifth aspects, wherein the inorganic material is formed by electrodeposition or vapor deposition, anodized, and further formed of metal ions. Was electrophoretically deposited and polarized to form the electret layer.
[0013]
The method for producing an inorganic electret actuator according to claim 8 is the method for producing an inorganic electret actuator according to any one of claims 1 to 5, wherein the inorganic material is formed into a sol or gel state, or is formed into a sheet and is heated. Alternatively, the electret layer is formed by using both heating and vacuum degassing.
[0014]
A method for manufacturing an inorganic electret actuator according to claim 9 is the method for manufacturing an inorganic electret actuator according to any one of claims 6 to 8, wherein heating and an electric field are applied simultaneously with the formation of the electret layer to provide orientation polarization, ionic polarization, and electronic polarization. At the same time.
[0015]
According to a tenth aspect of the present invention, there is provided the method of manufacturing an inorganic electret actuator according to any one of the sixth to eighth aspects, wherein after forming the inorganic material layer, heating, an electric field, and a magnetic field are applied, and the orientation polarization and the ionization are performed. Polarization and electronic polarization were performed.
[0016]
A method for manufacturing an inorganic electret actuator according to claim 11 is the method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein the pressurized state in the pressurized air or the oxygen-rich state with oxygen added during electretization processing. In this configuration, heating and an electric field are applied.
[0017]
According to a twelfth aspect of the present invention, there is provided the method for manufacturing an inorganic electret actuator according to any one of the first to fifth aspects, wherein the heating is performed in the atmosphere or in an oxygen-rich, oxygen-rich, normal pressure state during the electretization process. And an electric field.
[0018]
A method for manufacturing an inorganic electret actuator according to claim 13 is the method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein heating and an electric field are applied in a vacuum or reduced pressure degassing state during the electretization treatment. Things.
[0019]
A method for manufacturing an inorganic electret actuator according to claim 14 is the method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein heating and an electric field are applied in an inert gas atmosphere during electretization. It is.
[0020]
A method for manufacturing an inorganic electret actuator according to claim 15 is the method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein heating and an electric field are applied in an atmosphere in which a reducing gas or an organic gas is added during electretization. It is configured.
[0021]
A method for manufacturing an inorganic electret actuator according to a sixteenth aspect is the method for manufacturing an inorganic electret actuator according to the second aspect, in which after the inorganic material layer is formed, heating and an electric field are applied to perform orientation polarization, ionic polarization, and electronic polarization. In some cases, a sintering aid having a flux effect is added.
[0022]
A method of manufacturing an inorganic electret actuator according to a seventeenth aspect is the method of manufacturing an inorganic electret actuator of the sixteenth aspect, wherein the crystallinity of the specific gravity of the composite oxide (stoichiometric composition) to be generated is 80% or more and 95% or less. It is configured.
[0023]
An inorganic electret actuator according to an eighteenth aspect is the inorganic electret actuator according to the second aspect, wherein an electrode layer is formed on the electret layer via a titanium layer.
[0024]
An inorganic electret actuator according to a nineteenth aspect is the inorganic electret actuator according to the second aspect, wherein an electrode layer is formed on the electret layer via an insulating layer having a dielectric constant of 3 or more.
[0025]
In an inorganic electret actuator according to a twentieth aspect, in the inorganic electret actuator according to the second aspect, an electrode layer is formed on the electret layer via a layer of silicon nitride, aluminum nitride, or another nitrogen compound. Things.
[0026]
An inorganic electret actuator according to a twenty-first aspect is configured such that the inorganic electret actuator according to any one of the first to fifth aspects is multi-structured, arrayed, and blocked.
[0027]
An inorganic electret actuator according to a twenty-second aspect is the inorganic electret actuator according to the twenty-first aspect, wherein the inorganic electret actuator is multi-structured, arrayed, and blocked by a sandblast method, a dry etch method, a wet method, or a dicing method.
[0028]
A droplet discharge head according to a twenty-third aspect is configured such that the actuator for generating the pressure for discharging the droplet is any of the inorganic electret actuators according to the present invention.
[0029]
The optical device according to claim 24 is configured such that the actuator for driving the optical mirror surface is any of the inorganic electret actuators according to the present invention.
[0030]
An optical device according to claim 25 is the optical device according to claim 24, wherein the electrode surface of the inorganic electret actuator is an optical mirror surface.
[0031]
A pressure sensor according to a twenty-sixth aspect is configured to include an electret layer obtained by subjecting an inorganic material to orientation polarization, ionic polarization, and electronic polarization.
[0032]
The pressure sensor according to claim 27 is the pressure sensor according to claim 26, wherein the pressure sensor has a two-dimensional surface.
[0033]
An oscillator according to a twenty-eighth aspect is configured to include any one of the inorganic electret actuators according to the present invention.
[0034]
In a droplet discharge head according to a twenty-ninth aspect, the actuator for generating a pressure for discharging a droplet is the inorganic electret actuator according to any one of the first to fifth and eighteen to twenty-second aspects, and each actuator has only one electrode divided. Configuration and below.
[0035]
The motor according to claim 30 is configured to include a rotor including an electret layer obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electron polarization.
[0036]
An inorganic electret actuator according to claim 30 is the inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22, wherein the thickness of the electret layer is 1/5 or less of the drive electrode width for applying a voltage. It has a certain configuration.
[0037]
The inorganic electret actuator according to claim 31 is the inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22, wherein a groove is formed to incompletely divide the electret layer into a plurality of actuator portions. The thickness of the electret layer is less than half the thickness of the electret layer.
[0038]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
An embodiment of the inorganic electret actuator according to the first aspect of the present invention will be described with reference to FIG.
The inorganic electret actuator includes an electret layer 1 in which an inorganic material is oriented, ion-polarized, and electronic-polarized, and electrodes 2 and 3 are provided on both surfaces of the electret layer 1.
[0039]
Inorganic materials can be crystallized by incorporating cationic or anionic materials, or anodic or negative molecular groups, or ionic elements or atomic groups with different electronegativities, and crystallize to give an electric field and orientate 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, a monomorph vibration or a monomorph mechanical drive is generated as a whole.
[0040]
An example of a 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 ₂ O ₃ ・ 5SiO ₂ La of fine powder (average particle size 0.5-3 μm) is added to fine powder of composite oxide (average particle size 0.5-3 μm). ₂ O ₃ Is supplied to a belt 13 to form a green sheet 11 having a thickness of 50 μm while controlling the layer thickness by pressing with a press roller 14, and forming a cover on the green sheet 11. The sheet 15 is supplied and pressed by the pressing roller 16 to obtain a green sheet member as shown in FIG.
[0041]
Then, as shown in FIG. 3 (b), the green sheet 11 is subjected to a dehydration treatment, and as shown in FIG. 3 (b), primary firing is performed at 400 to 500 ° C., and as shown in FIG. 3 (d), When fired at 850 to 1200 ° C., high rigidity (8000 to 15000 kg / mm ² The 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. 4E, and placed at 450 ° C. in the air as shown in FIG. After holding for 1 hour, the substrate is cooled down while the electric field of 300 V DC is applied as shown in FIG. As a result, as shown in FIG. 2H, orientation and polarization occur, the crystal part is maintained while maintaining large distortion, and the electret layer 1 is formed into an inorganic electret with a large internal polarization.
[0043]
Here, a basic configuration of a device using the inorganic electret actuator is, for example, a deformable member (hereinafter, also referred to as a “diaphragm”) formed of a conductive material or an insulating material having a surface coated with an electrode material. The diaphragm is used as the lower electrode 3, and the paste or sol-gel of the inorganic material is screen-printed or metal-mask-printed on the lower electrode 3 to form an inorganic oxide under sintering conditions. Then, at the time of printing a metal mask, or after dividing into target elements by dry or wet etching or before, the upper electrode is formed by printing a metal paste and sintered. Voltage application and heating are simultaneously performed on the upper and lower electrodes 2 and 3 to form an inorganic electret.
[0044]
As described above, by configuring the inorganic electret actuator to include the electret layer in which the inorganic material is orientation-polarized, ion-polarized, and electronic-polarized, a novel lead-free actuator having high mechanical strength can be obtained.
[0045]
Next, an embodiment of the inorganic electret actuator according to the second aspect of the present invention will be described.
Here, the inorganic material includes a ferroelectric material, a dielectric material, or a solid electrolyte material, and further includes these grain-oriented ceramics. Specific materials include ZrTiO. ₄ -SnO ₂ TiO ₂ , Fe ₂ O ₃ -NiO, Zn ₂ TiO ₂ , ZnNiTiO ₄ , ZnFe ₂ O ₄ , K ₂ OAl ₂ O ₃ -SiO ₂ , CaOAl ₂ O ₃ , BaTiO ₃ , Al ₂ O ₃ TiO ₂ , MgOAl ₂ O ₃ There are many other polarizable inorganic materials.
[0046]
In addition, ionization and orientation polarization by a polyvalent atomic group can be performed by adding a transition metal system. As the crystal structure, there are a spinel structure, a perovskite structure, and a partially crystallized sintered body, and a cubic, rectangular, rhomboid, rhombohedral, or the like exists.
[0047]
The sintering temperature depends on the combination and composition ratio of the materials, the starting material of the raw material, and the particle dependence of the material. The temperature is about 200 ° C to 1200 ° C, but usually good results are obtained at 300 ° C to 600 ° C. Polarization reversal occurs due to hygroscopicity or a strong electric field due to applied voltage, causing functional degradation.However, under the atmosphere control conditions in this example, the material is dehydrated and highly oxidized. , Lifetime is satisfied.
[0048]
As a process, it is necessary to form a strain in a part of these crystals. However, a film thickness of 1 μm to 300 μm, a heating temperature of 300 ° C. to 400 ° C., and an applied voltage of DC 50 V to 500 V are sufficient.
[0049]
In addition, the grain oriented ceramics are obtained by first sintering the sintered ionic anisotropic fine powder, giving it high-temperature pressing directionality, and then crystallizing it by secondary pressure sintering to obtain oriented ceramics. And become polarized.
[0050]
Here, the basic configuration of a device using this inorganic electret actuator is, for example, that a diaphragm is formed of a conductive material or an insulating material coated with an electrode material on the surface, and this is used as a lower electrode, and this lower electrode is used as the lower electrode. The inorganic material paste or sol-gel is screen-printed or metal-mask-printed to form an inorganic oxide under sintering conditions. Then, at the time of printing a metal mask or after dividing into target elements by dry or wet etching, the upper electrode is formed and sintered by printing a metal paste. Voltage application and heating are simultaneously performed on the upper and lower electrodes to form an inorganic electret.
[0051]
As described above, when the inorganic material includes a ferroelectric material, a dielectric material, or a solid electrolyte material, since these materials themselves have a dipole moment and have polarization orientation, a large displacement can be obtained.
[0052]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 3 will be described.
Here, the target metal ion is selectively implanted into the inorganic material by an ion implantation apparatus to form a composition.
[0053]
Generally, many organic materials are based on corona discharge. Regarding organic resin materials, defects are induced in the crystal structure by electron implantation or ion implantation on the surface of miscellaneous blend resins such as fluorine resin, nylon (registered trademark) 11, etc. Polarization is being performed.
[0054]
On the other hand, with inorganic materials, the surface thermal oxide film SiO ₂ The (crystalline silicon oxide film) can be irradiated with an electron beam to generate lattice defects, form a charge trap layer, and form an electret layer. However, with an inorganic material, crystal distortion due to electron implantation is small, and there is almost no effect.
[0055]
Therefore, here, metal ions are implanted under reduced pressure. The manufacturing process of such an electret layer will be described with reference to FIG.
First, as shown in FIG. 3B, 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 up to about 100 to 3000 °, but here, there is only metal distortion in which metal is mixed and not ionized.
[0056]
Further, as shown in FIG. 3D, by performing the sintering diffusion process (heating diffusion process), the metal ions reach 0.5 to 10 μm and are ionized. Thereby, a phase effect of the crystal distortion and the ion effect can be exhibited. Then, as shown in FIG. 1E, the electrodes 2 and 3 are attached and electretization is performed to form the electret layer 1. In this case, a large ion polarization, charge polarization, and orientation polarization can be obtained.
[0057]
As described above, by adopting a configuration in which target metal ions are selectively implanted into the inorganic material and formed into a composition, ion orientation and polarization are increased due to increase in crystal distortion and composition of the introduced multiply-charged ions.
[0058]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 4 will be described.
Here, the inorganic material is a metal oxide (TiO 2). ₂ , NiO, Al ₂ O ₃ , Fe ₂ O ₃ , MnO ₂ , Co ₂ O3 / CoO, Sn ₂ O ₃ / SnO, ZnO, etc.) and alkaline earth compound oxides (BaO, K ₂ ZrTiO containing O, CaO, MgO, etc.) and a ferroelectric, dielectric, or solid electrolyte material ₄ -SnO ₂ TiO ₂ , Fe ₂ O ₃ -NiO, Zn ₂ TiO ₂ And ZnNiTiO ₄ , ZnFe ₂ O ₄ , K ₂ OAl ₂ O ₃ -SiO ₂ , CaOAl ₂ O ₃ , BaTiO ₃ , Al ₂ O ₃ TiO ₂ , MgOAl ₂ O ₃ It is a mixture composition of a polarizable inorganic material such as.
[0059]
In particular, a compound of an alkaline earth element is a material having a high crystallinity and a high ionic orientation, in which the element ion group functions as a cation and the other inorganic material functions as a negative ion. By controlling the oxidation-reduction atmosphere during firing of the composite oxide, a material having high ionicity can be obtained.
[0060]
The concept of this embodiment is shown in FIG. The example shown in the figure is an example of polarization due to the negativeness of an ion group, and orientation and polarization easily occur. Actually, Mg ₂ Al ₂ O ₄ And K ₂ SiO ₃ , BaFe ₂ O ₄ The complex salt material is polarized by high temperature and electric field.
[0061]
In this manner, by employing a structure in which the inorganic material contains a metal oxide or an alkaline earth metal oxide, ionic and charge polarization can be increased.
[0062]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 5 will be described.
ZrTiO ₄ -SnO ₂ TiO ₂ , Fe ₂ O ₃ -NiO, Zn ₂ TiO ₂ And ZnNiTiO ₄ , ZnFe ₂ O ₄ , K ₂ OAl ₂ O ₃ -SiO ₂ , CaOAl ₂ O ₃ , BaTiO ₃ , Al ₂ O ₃ TiO ₂ , MgOAl ₂ O ₃ And other non-metallic elements such as SiO ₂ , B ₂ O ₃ , P ₂ O ₅ , Sb2O5, Bi2O3) and a transition element oxide (V2O5, Cr ₂ O ₃ , CuO, Y ₂ O ₃ , Zr ₂ O ₃ , Nb ₂ O ₃ , Mo ₂ O ₃ , PD ₂ O ₃ , La ₂ O ₃ The valence control of the composite oxide containing a mixture of these elements is easy depending on the firing state and atmosphere of the composite oxide containing the transition element. This can result in controlling the magnitude of the crystal strain.
[0063]
FIG. 6 shows a conceptual diagram of this embodiment. Mixed oxides of inorganic dielectrics, polyvalent non-metallic elements, and transition elements are easily ionized due to the firing atmosphere, especially since polyvalent atoms and transition elements also have a low second ionization potential, and ion polarization by heating and electric field Then, orientation polarization occurs.
[0064]
As described above, by employing a structure in which the inorganic material is a composite oxide containing a transition metal oxide, unbonded ions can be retained in a crystal of a polyvalent element, and 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 phase growth method can be used. In this case, as shown in FIG. 7, for example, as shown in FIG. 7, an organic metal or chloride having high sublimability of an inorganic material is reduced in pressure and heated in a chamber 42 holding a substrate 41 constituting a base electrode by heating. And brought into contact with plasma or an oxidizing 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. FIG. 8 schematically shows a parallel plate electrode type plasma CVD apparatus.
[0066]
Further, an evaporation method can be used. In this case, a 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.
Further, in the sputtering method, the metal material is a DC power source and a sputtering gas (Ar, He, N2, ₂ In addition, RF sputtering can be performed on the inorganic material having no conductivity by using a high-frequency power supply with the same sputtering gas.
[0067]
The CVD apparatus and the sputtering apparatus are suitable for forming a thin film, and the film growth rate is about 10 to 300 ° / min. Further, the film can be easily formed while growing the crystal by heating the substrate.
[0068]
When forming a film using any of these methods, a single layer or a multi-layer film is formed according to the purpose, and at the time of film formation, a substrate is heated and a reaction gas is introduced to form an oxide or a nitride by a plasma reaction. To control the crystallinity and non-crystallinity.
[0069]
In this case, since the thin film to be formed is flat, the upper electrode is next formed by an evaporation method or a photolithography method, and an inorganic electret layer is formed by heating and an electric field.
[0070]
In addition, since the polarization effect is large in the thin film, when each element is formed as a multi-actuator as an actuator, mutual interference between the elements is small without dividing the element only by individualizing the upper electrode (the electrode 2). Is not necessary, and fine division is possible.
[0071]
As described above, one or more layers of an inorganic material are formed on a substrate by vapor deposition or vapor deposition, and when the film is formed, the substrate is heated and a reaction gas is introduced to form an oxide or a nitride to form a crystal. When the electret layer is formed by controlling the properties or the non-crystallinity, the crystallinity or the non-crystallinity 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 by electrodeposition or vapor deposition, and this is anodized. Anodization oxidizes anions with an electrode reaction. For this reason, the site portion where the electrode reacts with the ions at the same time as the formation of the oxide becomes a hole state, and the oxide becomes a porous state. As an example, anodized products of metal Al are well known.
[0073]
Depending on the inorganic acid (hydrochloric acid, sulfuric acid, nitric acid, perchloric acid) used, the inorganic acid and the organic acid (formic acid, acetic acid, succinic acid, oxalic acid), pH 1 to 6, the porous size in the oxide film is 50 to 3 μm. It can be controlled within a range. The thickness of the oxide can be regulated by controlling the voltage of the electrolytic current in the anodic oxidation reaction. In addition, metal ions required for polarization are added in the anodization step, and the ions are electro-deposited into the porous pores of the oxide by electrophoresis and taken into the oxide. A flat thin film of a material is formed, and then an upper electrode is formed by a vapor deposition method or a photolithography method, and an inorganic electret layer is formed by heating and an electric field.
[0074]
In addition, since the polarization effect is large in the thin film, when each element is multiplied as an actuator, the mutual interference between each element is small even if the element is not divided, only the individualization of the upper electrode. It is. When this is polarized, a large polarization alignment 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 made of a metal material such as Ni-Cr or SUS and serving as a lower electrode having a thickness of about 3 to 100 μm is provided. As shown in FIG. 4B, a film 56 of, for example, Al, Sn, Zn, or the like is formed on the vibration plate 53 to a thickness of, for example, 3 to 100 μm by an evaporation method or an electrodeposition method.
[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. Then, the diaphragm 53 and the counter electrode are electrically communicated through the hole 57, anions in the acid bath are transferred, and a chemical reaction is performed to form an anodic oxide film 58.
[0077]
Thereafter, a metal ion of a transition element is introduced into the acid bath, and electrodeposited in the hole 57. When this is subjected to a heat treatment (for example, 300 to 500 ° C.), a composite oxide film is obtained. Therefore, as shown in FIG. 2D, an upper electrode 52 serving as an individual electrode is formed, and a voltage of 100 to 800 V DC and heating at 300 to 800 ° C. are applied between the upper electrode 52 and the diaphragm 53 serving as a lower electrode. Then, 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 driving can be performed.
[0078]
As described above, the inorganic material is formed by electrodeposition or vapor deposition, anodized, and further, metal ions are electrodeposited by electrophoresis and polarized to form the electret layer. 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.
The inorganic material is mechanochemically mixed with a metal oxide or an alkaline earth metal oxide or a mixed material thereof with a transition metal oxide using a ball mill mixer or a mortar mixer. In this method, an organic solvent (alcohol, polyhydric alcohol, water, and additives (PVA, starch)) is added at the time of mixing, and crushed particles are stirred to form a sol or gel. 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 deaeration to form a composite oxide, which is formed on both surfaces by electrode baking or electrode screen printing, and then subjected to heating and 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 state inorganic material 72 obtained as described above is supplied onto a belt 73, and while controlling the layer thickness with a press roller 74, a green sheet 71 having a required thickness is formed. Then, a cover sheet 75 is supplied onto the green sheet 11, pressed by press rollers 74 and 76, sent to the next conveyor belt 77, and cut by a cutter 78 into an appropriate length.
[0082]
Next, heating and sintering are performed on the green sheet member obtained as described above as shown in FIG. 12 (a) to form a composite oxide, and electrodes are formed on both surfaces as shown in FIG. 12 (b). After forming 62 and 63, heating and electric field treatment are performed thereon, and electretization is performed to obtain an electret layer 61.
[0083]
The inorganic electret actuator 60 thus obtained is bonded with an adhesive 67 on, for example, a vibration plate 64 provided on a substrate 65 having an opening 65a. By applying a voltage between the electrode 62 and the diaphragm 63, monomorph vibration or monomorph mechanical driving can be performed.
[0084]
In this manner, the electret layer can be formed in a simple process by forming the inorganic material in a sol or gel state, or forming a film in a sheet shape, and forming the electret layer by heating or using heating and vacuum degassing in combination. .
[0085]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the ninth aspect of the present invention will be described.
An inorganic material layer is formed, and primary firing 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 is an unstable functional group partially composed of Si-OH, Al-OH, Fe-OH and the like.
[0086]
Therefore, in order to further perform appropriate heating treatment on the primary fired body, an appropriate electrification and an electric field are applied simultaneously with the formation of the inorganic electret layer, and the inorganic material performs orientation polarization, ionic polarization, and electronic polarization in the same step. At this time, the chemical composition of the inorganic material is Si—O—Si or Si ＝ O, depending on the atmospheric conditions. Dehydration becomes more complete, and the atomic groups are greatly affected by the electric field during the movement of the atomic groups during crystallization, so that 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. 3A, 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 has a hydroxyl group such as Si-OH, Al-OH, or Fe-OH.
[0088]
Thereafter, as shown in FIG. 2B, the electrodes 82 and 83 are formed and fired (heated) at 800 to 1200 ° C., and at the same time, a voltage of 200 to 400 V DC is applied to perform electretization. An electret layer 81 is obtained. At this time, by heating, Si-OH becomes K ₂ SiO ₃ Etc., and are oriented and polarized by an electric field and fixed.
[0089]
As described above, by applying heating and an electric field simultaneously with the formation of the electret layer and simultaneously performing the orientation polarization, the ionic polarization, and the electronic polarization, the polarization is facilitated.
[0090]
Next, an embodiment of a method of manufacturing an inorganic electret actuator according to the invention of claim 10 will be described.
By forming an inorganic material layer and performing appropriate high-temperature heat treatment, the chemical composition of the inorganic material becomes Si—O—Si or Si ＝ O depending on atmospheric conditions. This is an oxide in which the dehydration is more complete, the oxide formation is close to the stoichiometric composition, the crystallization is advanced, and the hygroscopicity, deliquescent, moisture adsorption sites and the like are small.
[0091]
Electrodes are formed on both surfaces, and then, for electretization as a secondary process, higher heating and a higher electric field are applied to perform orientation polarization, ionic polarization, and electronic polarization. Heating and the electric field have a mutual effect. In the case of low heating, a high electric field is required, and conversely, a high heating temperature results. However, the material has a melting point, and it is essential that the temperature be lower than that temperature.
[0092]
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 high temperature of 400 to 1200 ° C. to obtain a primary fired body 95. At this time, the primary fired body 95 is K ₂ SiO ₃ , BaFe ₂ O ₄ , K ₂ Al ₂ O ₄ In a state of advanced crystallization.
[0093]
After that, as shown in FIG. 2B, 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 to perform orientation and polarization, thereby performing electret. (Electrification and polarization are performed) to obtain an electret layer 91.
[0094]
As described above, after forming the inorganic material layer, by applying heating, an electric field, and a magnetic field to perform orientation polarization, ionic polarization, and electronic polarization, stable polarization can be performed.
[0095]
Next, an embodiment of a method for manufacturing an inorganic electret actuator according to the invention of claim 11 will be described.
Here, during the electretization treatment, heating and electric field treatment are performed in pressurized air of 1 atm or more or in an oxygen-rich pressurized state with oxygen addition. This makes it possible to obtain a compound in which the thermal diffusion of oxygen is sufficient and which has a high stoichiometric composition ratio of a high oxide.
[0096]
An element having a multivalent valence is, for example, Fe ₃ O ₄ Is divalent FeO and trivalent Fe ₂ O ₃ Is a complex oxide of ₂ O ₃ And a crystal-rich high oxide can be obtained.
[0097]
This is effective in increasing the cathodicity of the anion group. Furthermore, it is a high oxide and also electrically high and low antibody at the same time, has little diffusion and movement of surface charge, has a followability of high frequency driving, has a large electret effect, and has good stability. This step is similar to the description of FIGS. 2 and 3 described in the first embodiment of the present invention, and the heating and electric field applying steps shown in FIG. Since heating and electric field treatment are performed in compressed air or in an oxygen-rich pressurized state with oxygen addition, detailed description thereof is omitted.
[0098]
In this way, by applying heating and an electric field in pressurized air or in an oxygen-rich oxygen-pressurized state during the electretization treatment, the material can be made close to the stoichiometric composition, and a peroxide is formed. It is possible to improve reliability and function.
[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 the electretization treatment, heating and electric field treatment are performed in the atmosphere or in an oxygen-rich oxygen-added atmosphere at normal pressure. This makes it possible to form a flexible, stable and highly reliable oxide in which oxygen diffusion is dense and crystallinity and amorphousness are mixed.
[0100]
This step is similar to the description of FIGS. 2 and 3 described in the embodiment of the first aspect of the invention, and in the step of heating and applying an electric field in FIG. Since heating and electric field treatment are performed at normal pressure with oxygen richness, detailed description thereof will be omitted.
[0101]
As described above, by applying heating and an electric field in the atmosphere or in the oxygen-rich oxygen-rich state at the time of the electretization treatment, the crystallinity is large, 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, at the time of the electretization treatment, heating and electric field treatment are performed in a vacuum or degassed state under reduced pressure. This makes it possible to obtain a semiconductor material having a small internal resistance due to metal-rich crystallization and having a large strain deformation due to a low voltage applied electric field. 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]
In this step, as in the case of FIG. 2 and FIG. 3 described in the embodiment of the first aspect of the present invention, the heating step and the step of heating and the application of an electric field in FIG. Since the heating and the electric field treatment are performed in a gaseous state, a detailed description thereof will be omitted.
[0104]
As described above, by applying heating and an electric field in a vacuum or reduced pressure degassing state during the electretization treatment, degassing of a reducing atmosphere and impurities and removal of air between molecular grain boundaries can be performed, thereby increasing the crystallinity. That is, attached oxygen and weakly bound oxygen are eliminated, the amount of volatile additives is significantly reduced, and a high-purity composite oxide is obtained, so that densification and crystallinity are improved.
[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 electretization treatment for semiconductor conversion, heating and electric field treatment are performed in an inert gas atmosphere in a gas atmosphere of argon, helium, nitrogen, or the like. As a result, the metal material or the inorganic material dehydrates and diffuses and crystallizes the internal element in the absence of an anion element. Is obtained.
[0106]
Note that, also in this step, the heating and electric field application steps in FIG. 3F are performed under the inert gas atmosphere as described above with reference to FIGS. 2 and 3 described in the first embodiment of the present invention. Since the heating and the electric field treatment are performed in step (a), detailed description thereof will be omitted.
[0107]
As described above, by applying heating and an electric field in an inert gas atmosphere during electretization processing, electrode oxidation is not lost or oxidized even at high temperature processing, and resistance is not increased. A crystal mass and its grain boundaries (boundary) are thin, and the crystallinity 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 treatment, hydrogen, carbon monoxide or a reducing gas is added to the inert gas, or ammonia, alcohol, an aromatic gas, a ketone-based gas, or an aldehyde-based gas is added 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 and carbon monoxide occurs. This regulates its amount and forcibly controls deoxygenation. Further, there is a reducing action, and the inorganic material is converted into a semiconductor.
[0109]
Note that, also in this step, as described above in the steps of heating and applying an electric field in FIG. Since heating and electric field treatment are performed in a gas-added atmosphere, detailed description thereof is omitted.
[0110]
As described above, by applying heating and an electric field in a reducing gas or organic gas added atmosphere during the electretization treatment, it is possible to particularly control the valence of the polyvalent element of the transition metal element and increase the crystallinity and distortion. Since the forcible reduction prevents the growth of the oxide grain boundaries, a fine crystal lump and a thin grain boundary (boundary) can be obtained.
[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 including a ferroelectric material, a dielectric material, or a solid electrolyte material is used to form an inorganic material layer using, for example, the manufacturing method according to the invention of claim 6, 7, or 8, and then heating is performed. When performing orientation polarization, ionic polarization, and electronic polarization by applying an electric field, a sintering aid having a flux effect is added.
[0112]
This is to add vitreous, CuO, Bi ₂ O ₃ , PbO, B ₂ O ₃ , Sb ₂ O ₅ , P ₂ O ₅ Also, alkaline earth carbonates and nitrates are added. ₃ , BaCO ₃ , K ₂ CO ₃ , Or Ca (NO ₃ ) ₂ , Ba (NO ₃ ) ₂ , KNO ₃ And the like are added at 0.5 to 10 wt%.
[0113]
These are effective as sintering aids for inorganic materials, and can be prevented from becoming brittle 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, and it is 8000 kg / mm2 to 20,000 kg / mm. ² And a large driving force as a monomorph actuator can be obtained.
[0114]
FIG. 15 shows the state of the crystal grain boundaries in this case. As shown in FIG. 3A, when no fluxing agent is added, voids (small voids) are present at the crystal grain boundaries, and an amorphous material exists at the crystal grain boundaries. This amount is controllable.
[0115]
Here, when a fluxing agent is added, as shown in FIG. 3B, a vitreous material is formed at the same time as the decomposition, and the material is condensed in the melted portion, thereby preventing generation of voids. Therefore, low-temperature firing becomes possible. Also in this case, an amorphous body is present at the crystal grain boundaries, and the material exhibits the effect of preventing embrittlement and some flexibility.
[0116]
As described above, by applying a heating and an electric field after forming the inorganic material layer, and adding a sintering aid having a flux effect when performing orientation polarization, ionic polarization, and electronic polarization, a ferroelectric substance, a dielectric substance, Or, by forming an inorganic material layer containing a solid electrolyte material and adding a sintering aid having a flux effect, it becomes easy to control the crystallinity and the grain boundary gap by 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 seventeenth aspect will be described.
Also 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 process of the invention according to claim 6, 7, or 8, and then heating and When orientation polarization, ionic 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 to cause melting and decomposition by heating, crystallization starts even at a temperature at which crystal growth does not occur in the composite oxide of the main material. This is because, when the sintering aid is heated and melted and decomposed, ions and radicals, as well as 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 becomes the main material. The surfaces of the composite oxide grain boundaries react with each other to grow crystals or form a composite salt (amorphous) glass body of the composition of the constituent material of the main material and the sintering aid. As a result, a composite oxide of the main material crystal growth and the amorphous body is formed. This can form a dense structure with high brittleness and little flexibility with high crystallinity.
[0119]
Here, the composition ratio depends on the amount of the 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 of the composite oxide stoichiometric composition (closest packed) crystal specific gravity of the main material is the reliability of crystal strain, elastic modulus, denseness, and flexibility. Large actuator is obtained.
[0120]
As described above, when the sintering aid is added, the crystallinity of the generated composite oxide (stoichiometric composition) specific gravity is set to 80% or more and 95% or less, so that electric field distortion depending on crystallinity is obtained. Further, the amorphous portion has flexibility, cracks due to monomorph driving do not occur, and the device has high workability, and a finely processed device can be formed.
[0121]
Next, an embodiment of the inorganic electret actuator according to the eighteenth aspect will be described.
Also 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 process of the invention according to claim 6, 7, or 8, and then heating and An electric field is applied to perform orientation polarization, ionic polarization, and electronic polarization.
[0122]
An electrode is formed on the composite oxide by depositing a titanium layer as an underlayer by vapor deposition or baking with frit glass, and reacting with the element of the composite oxide or the highly diffusible element of the sintering aid. And ion diffusion of the electrode material is prevented. Further, the adhesion is improved. Thereafter, an electrode is formed of nickel or an alloy thereof, which is an electrode material, or a noble metal material. Here, the property that the chemical stability of the 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 surfaces of the electret layer 101 via titanium (Ti) layers 104 and 104, respectively. 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 configuration in which the electrode layer is formed on the electret layer with the titanium layer interposed therebetween, it is possible to prevent ion diffusion from the inorganic material, prevent alloying, and prevent oxidation due to oxygen diffusion. An electrode can be formed on the electrode using nickel or an alloy thereof or a noble metal material, thereby improving reliability.
[0125]
Next, an embodiment of the inorganic electret actuator according to the nineteenth aspect will be described.
Also 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 process of the invention according to claim 6, 7, or 8, and then heating and An electric field is applied to perform orientation polarization, ionic polarization, and electronic polarization.
[0126]
The composite oxide electret has an effect caused by 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 using an insulating layer having a large dielectric constant as a base. Thereby, it is possible to prevent the reaction with the element of the composite oxide and the element having high diffusibility of the sintering aid, and to prevent the ion diffusion of the electrode material. This is particularly effective when the composite oxide is a material having the resistance of the semiconductor region.
[0127]
As described above, by adopting a structure in which the electrode layer is formed with respect to the electret layer via the insulating layer having a dielectric constant of 3 or more, the voltage drop due to the division of the applied voltage can be reduced, and the voltage is applied. An electric field is efficiently applied to the inorganic material, and further, an impurity element is blocked by the insulating layer, so that an actuator without electrode damage can be obtained.
[0128]
Next, an embodiment of the inorganic electret actuator according to the twentieth aspect will be described.
Also 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 process of the invention according to claim 6, 7, or 8, and then heating and An electric field is applied to perform orientation polarization, ionic polarization, and electronic polarization.
[0129]
Then, when an electrode is formed, 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 the electric field potential does not drop much.
[0130]
In this manner, by adopting a structure in which the electrode layer is formed with respect to the electret layer via a layer of silicon nitride, aluminum nitride, or another nitrogen compound, a nitrogen compound having a stoichiometric composition can be easily formed. It can be formed and its crystal is dense, so that diffusion of impurities can be prevented, ion diffusion from inorganic materials, alloying prevention, oxidation by oxygen diffusion can be prevented, and stable characteristics can be obtained. Is obtained.
[0131]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 21 will be described.
Although depending on the size of the crystal grains, the inorganic material composite oxide is not limited to a single driving element, but can be multiplied, arrayed, or blocked. As a result, 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 that are arrayed one-dimensionally. Further, a writing sensor and an input sensor can be used as the two-dimensional surface pressure sensor.
[0132]
As described above, by making the inorganic electret actuator multi-layered, arrayed, or blocked, an actuator suitable for the purpose can be configured.
[0133]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 22 will be described.
The thickness of the inorganic material composite oxide can be widely adjusted to 0.5 μm to 3 μm by a manufacturing method. As a driving element for mechanically driving the monomorph, various methods can be used as a method for performing multi-unit, arraying, and blocking.
[0134]
For example, when dividing into 50 to 200 dpi by the sandblasting method, an appropriate pattern is formed with a dry film resist, the blast is made of a material having a high hardness such as 3 to 8 μm of SiC, and a pressure of 2 atm and a flow rate of 3 to 5 m /. Process with s. In the case of this method, the minimum is the formation of a 50 μm element, but a large number of elements having a large area can be manufactured in a short time.
[0135]
In the case of dry etching, although it depends on the constituent material of the inorganic material composite oxide, after the formation of the resist pattern, sublimation etching is performed by a RIE reaction using fluorine, chlorine, and bromine. Anisotropy and isotropy are possible depending on the conditions. Although this depends on the aspect ratio, an element of 10 μm can be manufactured at 0.5 to 1.
[0136]
In the case of the wet method, an ion dissolving etchant of an inorganic material composite oxide is used. However, it is only isotropic and is a mixture of mineral acids. An element of 30 μm is common in mass production.
[0137]
Although the dicing method can be used, the dicing blade has a limit of 20 μm in width and has problems such as chipping. The driving element has a limit of 30 μm.
[0138]
Here, an example of element division by etching will be described with reference to FIG. As shown in FIG. 1A, for example, an electret layer 111 is formed on a diaphragm 113 which also serves as a lower electrode, and as shown in FIG. 2B, an upper electrode 112 is formed on the electret layer 111. Further, a resist 115 is formed.
[0139]
Then, as shown in FIG. 4C, a predetermined resist pattern 116 is formed by etching with blast, reaction ions, and a reaction solution, and then the upper electrode 112 is etched as shown in FIG. Then, the electret layer 111 is sequentially etched to be divided into a plurality of actuator elements 110. After that, the resist pattern 116 is removed as shown in FIG.
[0140]
As described above, the elements can be efficiently formed by being multi-layered, arrayed, or blocked by a sand blast method, a dry etch method, a wet method, or a dicing method.
[0141]
Next, an embodiment of a droplet discharge head according to the invention of claim 23 will be described. Here, the inorganic material composite oxide is arrayed and divided (blocked) to drive the diaphragm of a droplet discharge head such as an ink-jet head on demand so that 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]
An example of the configuration of an ink jet head that is such a droplet discharge head will be described with reference to FIGS.
A liquid chamber 124 is formed by joining the flow path forming member 121 made of a porous body and the 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]
Then, an electret actuator 130 using the diaphragm 123 as a lower electrode is provided on the diaphragm 123. Here, the electret layer 131 and the electrodes 132 of the electret actuator 130 are independently divided corresponding to the respective liquid chambers 124, and the diaphragm 123 is not divided and used as a common electrode.
[0144]
In this inkjet head, ink is supplied from the common liquid chamber 127 to the liquid chamber 124 through the porosity 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. The ink droplet is ejected from the nozzle 125 while being deformed 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 optical device according to an embodiment of the present invention will be described.
Here, an inorganic material electret actuator is provided corresponding to the optical mirror surface that reflects light, and the actuator is mechanically driven to deform the optical mirror surface and perform optical bending 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 an electrode is formed by screen printing or metal mask vapor deposition, etc., and sintered at an electric field of 300 V and heating at 250 ° C. Each monomorph driving element may form a slit between adjacent elements to facilitate driving. The optical mirror surface can be manufactured by a vapor deposition method, an electrodeposition method, or the like.
[0148]
An example of this optical device will be described with reference to FIGS.
In this optical device, a diaphragm (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 an individual electrode 152 are provided on the diaphragm 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 an evaporation method, an electrodeposition method, or the like.
[0149]
FIG. 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 substantially in the center of the opening 155a.
[0150]
In this optical device, when the electret actuator 150 is not driven, the optical mirror surface 156 is flat, and 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 by a phantom line to become a convex mirror, so that the incident light 158 becomes scattered light.
[0151]
As described above, by configuring the optical device using the inorganic electret actuator according to the present invention, it is possible to configure an optical device including an actuator that performs a novel mechanical drive.
[0152]
Next, an embodiment of the optical device according to the invention of claim 25 will be described.
Here, the optically smooth surface of the underlying electrode is maintained by a thin film forming method, drive elements including inorganic electret actuators are formed, and the divided drive electrode surfaces are optically cleaned while the individual electrode surfaces of each element maintain the underlying smooth surface. As a mirror, an optical device that bends light corresponding to each drive element is obtained.
[0153]
An example of this optical device will be described with reference to FIG.
This optical device has a silicon oxide (SiO 2) on a silicon wafer 165 as shown in FIG. ₂ A) A film 166 is formed with a thickness of 2 to 5 μm, and a base electrode 163 is formed on the SiO 2 film 166 with Pt, Au, Ni—Cr or the like.
[0154]
Then, an electret layer 161 is formed on the electrode 163 as shown in FIG. 2B, and a drive electrode 162 is formed on the electret layer 161 with Al, Ag or the like 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, as shown in FIG. 4D, an opening 165a is formed in the silicon wafer 155 by silicon etching or the like. At this time, the SiO 2 film 166 serves as an etching stop layer and also forms a deformable portion (diaphragm).
[0156]
In this optical device, when the electret actuator 160 is not driven, the optical mirror surface 167 is flat, so that 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 and becomes a convex mirror or a concave mirror, so that the incident light 168 becomes scattered light.
[0157]
By thus configuring the optical device having the electrode surface as the optical mirror, the configuration is simplified.
[0158]
Next, an embodiment of the pressure sensor according to the invention of claim 26 will be described.
When the inorganic electret layer is deformed by receiving an external pressure, the electret layer undergoes a pyroelectric voltage generation and a resistance change due to internal crystal distortion. By detecting the change in voltage or resistance, a pressure sensor that displays an external pressure as an electric signal based on a rise in gate voltage of the switching element or a change in partial pressure can be configured.
[0159]
Next, an embodiment of the pressure sensor according to the invention of claim 27 will be described. By multiplying the inorganic electret and forming an in-plane two-dimensional pressure sensor, a writing sensor or a two-dimensional surface distribution pressure sensor can be formed.
[0160]
An example of a writing input sensor using the pressure sensor according to 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 electrodes 173 and the Y electrodes 172 are arranged in a matrix. Further, 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, a voltage generated or a voltage dividing resistance changes at a portion where the X electrode 173 and the Y electrode 172 cross each other. A corresponding output is obtained.
[0162]
Next, an embodiment of the transmitter according to the invention of claim 28 will be described.
Here, the inorganic material electret configuration can be freely formed in elastic modulus (rigidity) and shape. The material of the vibrator is not limited to the organic material, but can be made of a material with a high resonance point and a shape configuration by bonding an inorganic material, a ceramic film, a metal film, or an organic film and an inorganic material film. A wide range of oscillators can be configured. With organic electrets, material cones and horns with high rigidity are difficult to drive, and high-frequency oscillations cannot follow, and there is a limit.
[0163]
Next, an embodiment of a droplet discharge head according to the present invention will be described. For the thin film inorganic material electret, a film having a thickness of about 0.5 to 100 μm can be freely selected. Therefore, an inorganic electret actuator suitable for the purpose is produced, and only individual electrodes for mechanically driving the actuator are divided into a target size to form an array. As a result, it is possible to configure a droplet discharge head in which the mutual interference between adjacent bits is reduced and a stable discharge characteristic is obtained without forming the drive elements (entire actuators) in an array and dividing (blocking) them.
[0164]
Here, an example of an ink jet head which is a droplet discharge head will be described with reference to FIG.
In this head, a vibrating plate 183 also serving as a common electrode is formed on a flow path forming member 185, an electret layer 181 is formed on the vibrating plate 183, and the electret layer 181 is further divided by each bit. By providing the electrodes 182, a plurality of inorganic electret actuators 180 are provided corresponding to the respective nozzles 187 of the respective liquid chambers 186.
[0165]
In this case, since the plurality of inorganic electret actuators 180 have the electret layer 181 and the vibration plate 183 integrated with each other, the head has reduced mutual interference between adjacent bits.
[0166]
Next, an embodiment of the motor according to claim 30 will be described.
Here, by using an inorganic material electret configuration, an appropriate electret area is set in the plane, or an appropriate shape is cut out and set on the rotor of the electrostatic motor, so that the rotational speed according to 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 the electret motor includes stators 201A to 201D and a rotor 202 using an electret. Then, similarly to the principle of rotation of the induction motor shown in FIG. 27, by changing the voltage applied to the stators 201A to 201D, suction and repulsion occur with the rotor 202, and the rotor 202 rotates.
[0168]
Therefore, in the inorganic material electret layer 200 according to the present invention, since the substrate can be divided without physically dividing the substrate, an electret motor can be configured by using this for a rotor.
[0169]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 31 will be described.
When the inorganic material is formed into a thin film by flattening, 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 rigidity of the monomorph diaphragm is 5,000 to 12,000 kg / mm. ² When the film thickness is equal to or less than the electret film thickness, the aspect ratio (b / a) where the mutual interference is small is 1/5 or less, and the mutual interference noise can be completely ignored is 1/8 or less. . As a result, it is possible to perform the fine division driving in which the process is deleted and the mutual interference is reduced.
[0170]
For example, as shown in FIGS. 29 and 30, an inorganic electret actuator 210 is formed by forming an electret layer 211 and an electrode 212 on a diaphragm 213 of the droplet discharge head using an inorganic electret actuator as an actuator of a droplet discharge head. When the thickness of the diaphragm 213 is equal to or less than the thickness of the electret layer 211 and the electrode 212, when the thickness of the electret layer 211 is b and the element width (the width of the drive electrode 212) is a, b / a is set to 1/5 or less, preferably 1/8 or less.
[0171]
Next, an embodiment of the inorganic electret actuator according to the invention of claim 32 will be described.
An electret structure in which an inorganic material is flattened to form a thin film, and orientation polarization, ionic polarization, and electron polarization are applied.When multiple elements are not used to completely divide the element and grooves are formed between sensor elements, individual electrodes are used as masks. Etch or cut grooves with an equivalent pattern. The groove depth is such that the rigidity of the monomorph diaphragm is 5000 to 12000 kg / mm. ² In this range, the film thickness of the film and the thickness of the electret film are formed to be equal 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 以下 or less of the thickness of the electret layer, and the ignorable mutual interference noise is １ ／ or less. As a result, it is possible to perform the fine division driving in which the process is deleted and the mutual interference is reduced.
[0172]
For example, as shown in FIG. 31, an inorganic electret actuator is used as an actuator of 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 a groove 224. When a plurality of inorganic electret actuators 220 are configured and 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 set to c, and the thickness of the electret layer 221 corresponding to the groove 224 is set to d. In this case, the groove depth is set so that d / c is 1/2 or less, preferably 1/5 or less.
[0173]
【The invention's effect】
As described above, the inorganic electret actuator according to the present invention is configured to include the electret layer in which the inorganic material is subjected to the orientation polarization, the ion polarization, and the electron polarization, so that the actuator is capable of obtaining a lead-free large mechanical displacement. According to the method for manufacturing an inorganic electret actuator according to the present invention, it is possible to manufacture the lead-free inorganic electret actuator according to the present invention, which can provide a large mechanical displacement. Furthermore, according to the droplet discharge head, the optical device, and the transmitter according to the present invention, a novel head, optical device, and transmitter including the inorganic electret actuator according to the present invention can be obtained, and the pressure sensor according to the present invention can be obtained. According to the motor, a novel pressure sensor and motor having an inorganic electret layer can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory sectional view of an inorganic electret actuator according to the first embodiment of the present invention;
FIG. 2 is an explanatory diagram for explaining an example of a manufacturing process of the inorganic electret actuator.
FIG. 3 is an explanatory sectional view illustrating a step following FIG. 2;
FIG. 4 is a cross-sectional explanatory view illustrating an inorganic electret actuator according to the invention of claim 3 together with a manufacturing process thereof.
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 of manufacturing an inorganic electret actuator according to the invention of claim 6;
FIG. 8 is a schematic explanatory view of another example of a CVD apparatus for explaining a method of manufacturing an inorganic electret actuator according to the invention of claim 6;
FIG. 9 is an explanatory sectional view 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 a main part in the same manner.
FIG. 11 is an explanatory view for explaining a method for manufacturing an inorganic electret actuator according to the invention of claim 8;
FIG. 12 is an explanatory sectional view illustrating a step following FIG. 11;
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 view for explaining a method for 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 explaining a method for manufacturing an inorganic electret actuator according to the invention of claim 18;
FIG. 17 is an explanatory view explaining an inorganic electret actuator according to the invention of claim 22 together with its manufacturing process.
FIG. 18 is an explanatory sectional view for explaining a droplet discharge head according to the invention of claim 23;
FIG. 19 is a perspective explanatory view of the same.
FIG. 20 is an explanatory cross-sectional view for explaining the optical device according to the invention of claim 24;
FIG. 21 is a perspective explanatory view of the same.
FIG. 22 is an explanatory view 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 write input sensor as a pressure sensor according to the invention of claim 26;
FIG. 24 is an explanatory sectional view of the same.
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 describing the motor according to the twentieth aspect of the present invention.
FIG. 27 is a diagram illustrating the principle of the induction motor.
FIG. 28 is a perspective view for explaining a rotor using an inorganic electret.
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 an explanatory sectional view of the same.
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 (32)

An inorganic electret actuator comprising an electret layer obtained by subjecting an inorganic material to orientation polarization, ion polarization, and electronic polarization. The inorganic electret actuator according to claim 1, wherein the inorganic material includes a ferroelectric, a dielectric, or a solid electrolyte material. 3. The inorganic electret actuator according to claim 2, wherein target metal ions are selectively implanted into the inorganic material to form a composition. The inorganic electret actuator according to any one of claims 1 to 3, wherein the inorganic material includes a metal oxide or an alkaline earth metal oxide. The inorganic electret actuator according to any one of claims 1 to 4, wherein the inorganic material is a composite oxide containing a transition metal oxide. 6. The method for manufacturing an inorganic electret actuator according to claim 1, wherein one or more layers of the inorganic material are formed on the substrate by vapor deposition or vapor deposition, and the substrate is heated during the film formation. And forming a reactant gas to form an oxide or a nitride to control crystallinity or amorphousness to form the electret layer. The method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein the inorganic material is formed by electrodeposition or vapor deposition, anodized, and further, metal ions are electrodeposited by electrophoresis, A method for manufacturing an inorganic electret actuator, comprising forming the electret layer by polarizing. The method for manufacturing an inorganic electret actuator according to any one of claims 1 to 5, wherein the inorganic material is in a sol or gel state, or is formed into a sheet, and heating or heating and vacuum degassing are used in combination. A method for manufacturing an inorganic electret actuator, characterized in that the electret layer is formed by heating. The method for manufacturing an inorganic electret actuator according to any one of claims 6 to 8, wherein heating and an electric field are applied simultaneously with the formation of the electret layer to simultaneously perform orientation polarization, ionic polarization, and electronic polarization. A method for manufacturing an electret actuator. 9. The method for manufacturing an inorganic electret actuator according to claim 6, wherein after forming the inorganic material layer, heating, an electric field, and a magnetic field are applied to perform orientation polarization, ionic polarization, and electronic polarization. Of manufacturing an inorganic electret actuator. The method for producing an inorganic electret actuator according to any one of claims 1 to 5, wherein heating and an electric field are applied in pressurized air or in a pressurized state in an oxygen-rich state with oxygen added during electretization processing. Of manufacturing an inorganic electret actuator. 6. A method for producing an inorganic electret actuator according to claim 1, wherein heating and an electric field are applied in the atmosphere or in an oxygen-rich, oxygen-rich state at normal pressure during electretization. A method for manufacturing an electret actuator. 6. The method for manufacturing an inorganic electret actuator according to claim 1, wherein a heating and an electric field are applied in a vacuum or reduced pressure degassing state during the electretization process. 6. The method for manufacturing an inorganic electret actuator according to claim 1, wherein a heating and an electric field are applied in an inert gas atmosphere during the electretization treatment. 6. The method for producing an inorganic electret actuator according to claim 1, wherein heating and an electric field are applied in an atmosphere in which a reducing gas or an organic gas is added during electretization. Method. 3. A method for manufacturing an inorganic electret actuator according to claim 2, wherein a heating and an electric field are applied after forming the inorganic material layer to perform orientation polarization, ionic polarization, and electronic polarization, and a sintering aid having a flux effect. And an inorganic electret actuator. 17. The method for manufacturing an inorganic electret actuator according to claim 16, wherein a crystallinity of a specific gravity of a composite oxide (stoichiometric composition) to be generated is set to 80% or more and 95% or less. A method for manufacturing an inorganic electret actuator. 3. The inorganic electret actuator according to claim 2, wherein an electrode layer is formed on the electret layer via a titanium layer. 3. The inorganic electret actuator according to claim 2, wherein an electrode layer is formed via an insulating layer having a dielectric constant of 3 or more with respect to the electret layer. 3. The inorganic electret actuator according to claim 2, wherein an electrode layer is formed on the electret layer via a layer of silicon nitride, aluminum nitride, or another nitrogen compound. The inorganic electret actuator according to any one of claims 1 to 5, wherein the actuator is multi-layered, arrayed, or blocked. 22. The inorganic electret actuator according to claim 21, wherein the actuator is multi-layered, arrayed, or blocked by a sandblast method, a dry etch method, a wet method, or a dicing method. 23. A droplet discharge head for discharging droplets, wherein the actuator for generating a pressure for discharging the droplets is the inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22. Discharge head. 23. An optical device having an optical mirror surface for reflecting light, wherein the actuator for driving the optical mirror surface is the inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22. 25. The optical device according to claim 24, wherein an electrode surface of the inorganic electret actuator is the optical mirror surface. A pressure sensor comprising an electret layer obtained by subjecting an inorganic material to orientation polarization, ionic polarization, and electronic polarization. The pressure sensor according to claim 26, wherein the pressure sensor has a two-dimensional surface. An oscillator comprising the inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22. In a droplet discharge head for discharging droplets, an actuator for generating a pressure for discharging the droplet is the inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22, and each actuator is one electrode. A droplet discharge head characterized in that only one is divided. A motor comprising: a rotor including an electret layer in which an inorganic material is orientation-polarized, ion-polarized, and electron-polarized. The inorganic electret actuator according to any one of claims 1 to 5, and 18 to 22, wherein a thickness of the electret layer is 1/5 or less of a width of a driving electrode for applying a voltage. Inorganic electret actuator. 23. The inorganic electret actuator according to any one of claims 1 to 5, 18 to 22, wherein a groove is formed which divides the electret layer incompletely into a plurality of actuator portions, and the thickness of the electret layer in the groove portion. Is not more than の of the thickness of the electret layer.

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