JP3014379B1 - Low temperature forming method of piezoelectric / electrostrictive film and piezoelectric / electrostrictive film formed by the method - Google Patents

Abstract

The present invention provides a piezoelectric / electrostrictive film which has superior piezoelectric characteristics, simplifies a manufacturing process, saves energy, and shortens a process lead time, and a method for manufacturing the same. SOLUTION: A step of manufacturing a solution containing the constituent materials by dissolving the ceramic constituent materials in a solvent, a step of adding a citric acid to a solution mixture in which the constituent components are dissolved, and a step of mixing. Heat-treating the liquid to cause a non-explosive oxidation-reduction combustion reaction to form an ultrafine oxide powder having a uniform particle size distribution without scattering, and to form constituent elements based on water or an organic solvent. Dissolving to produce a sol solution, mixing an ultrafine oxide powder and a sol solution to produce a paste, forming a piezoelectric / electrostrictive film using the paste as a substrate, Subjecting the strained film to low temperature heat treatment to remove the solvent and allow the sol to act as a reaction medium on the surface of the oxide particles to induce bonding between the ultrafine particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a piezoelectric / electrostrictive film at a low temperature using an ultrafine ceramic oxide powder and a piezoelectric / electrostrictive film manufactured by the method. A method of forming a piezoelectric / electrostrictive film at a low temperature using a super-reactive ultra-fine ceramic oxide powder manufactured in a single step at a low temperature using an acid as a combustion aid and manufactured by the method. Related to a piezoelectric / electrostrictive film.

[0002]

2. Description of the Related Art Ink jet heads, memory chips,
Regarding ceramic oxide powder, which is a raw material in the manufacture of various devices using ceramics such as piezoelectric materials, emphasis is placed on miniaturization of unit particles and uniformization of particle size distribution. this is,
This is because in the case of fine particles, reactivity and applicability can be improved by reducing activation energy by surface treatment or charging the particles.

[0003] In the production of various membrane devices using ceramics, in order to form a piezoelectric / electrostrictive film on a diaphragm, conventionally, a ceramic sol whose viscosity has been adjusted or modified with a suitable solvent has been used. A method of attaching a ceramic oxide powder to a diaphragm has been mainly used.

[0004] Considering the quality of the finally obtained film, the methods mainly used for ceramic sols are dip coating, spin coating, electrochemical redox method (electroc redox method).
Chemical oxidation / reduction) and other methods used for ceramic oxide powder include various printing methods, molding methods, and electrophoretic vapor deposition methods (el
ectrophoretic deposition).

[0005] Among them, the printing method, molding method and coating method are examined as follows.

In the printing method, a ceramic paste is manufactured using a ceramic oxide powder, printed on a diaphragm using a screen or the like, and then subjected to a binder removal treatment at 500 ° C. or more and a heat treatment at 100 ° C. or more. This is a method of forming a piezoelectric / electrostrictive film having a predetermined thickness by firing.

[0007] In the molding method, similarly to the printing method, a ceramic paste is manufactured and applied to an uneven mold formed on a diaphragm to form a ceramic film. This is a method for producing a piezoelectric / electrostrictive film by performing a heat treatment at 1,000 ° C. or more and firing.

As a coating method, a ceramic sol or ceramic paste whose fluidity is adjusted is placed at the center, and the diaphragm is rotated to coat the ceramic sol or the ceramic paste on the diaphragm, and then dried and then sintered. Coating method, dip coating to impregnate the diaphragm with ceramic sol and coat the ceramic sol on the diaphragm by surface tension,
There is a spray coating method in which a ceramic sol is sprayed onto a diaphragm through a nozzle to perform coating. Also in such a coating method, after forming a ceramic film on the diaphragm, the binder is removed at 500 ° C. or more,
By baking after heat treatment at 1,000 ° C or more,
Manufacture piezoelectric / electrostrictive films.

Although the coating method has disadvantages for use in actuators, it is usefully applied to many other devices, particularly to produce films having a thickness at the boundary between thin and thick films. Sometimes useful.

FIG. 2 shows a process for manufacturing a conventional piezoelectric / electrostrictive film as described above.

Conventionally, in order to produce a ceramic paste used for a printing method, a molding method or a coating method, a binder for securing the inherent properties of the paste and ceramic particles are uniformly dispersed to make the paste uniform, and the printing is performed. In order to be applied to a vehicle, a vehicle for imparting appropriate fluidity, a plasticizer for enabling fine molding, a dispersant for imparting homogeneity to a paste, and the like are dissolved and dispersed in a solvent. A method in which ceramic particles having an average particle size of 1 μm manufactured by a solid phase method are added to a solution, followed by mixing and stirring.

When a ceramic oxide powder produced by a conventional solid phase method is used, the above-mentioned organic substances must be added without fail. If no organic substances are added, the viscosity of the ceramic paste is adjusted. In addition, when the ceramic paste is coated on the diaphragm, there is a problem that the coating is not performed.

Further, the ceramic paste produced by such a method cannot be molded at a low temperature because of the large size of the ceramic particles. In the case of a dispersant, the paste is unilaterally provided without information on the composition or the production method. There are drawbacks that should be dependent on the supplier.

In order to manufacture a piezoelectric / electrostrictive film using the ceramic paste manufactured by the above method, the ceramic paste is printed or molded on a vibrating plate, dried at 130 ° C., and heated at 1,000 ° C. or more. Although the heat treatment is performed, there is a problem that before the heat treatment after the drying, another additional heat treatment should be performed at a temperature of 500 ° C. or more in order to remove the added organic component at all.

Further, since the heat treatment must be performed at 1,000 ° C. or higher, there is a problem that the range of the diaphragm that can be selected is limited.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a combustion process using citric acid as a combustion aid and a single process at a low temperature.
A method of forming a piezoelectric / electrostrictive film by using a ceramic oxide powder having a very fine particle size and a very high reactivity by a printing method, a molding method and a coating method and a low-temperature heat treatment. It is an object of the present invention to provide a piezoelectric / electrostrictive film formed at a lower temperature.

[0017]

In order to achieve the above object, the present invention provides a solution or dispersion mixture containing a ceramic constituent material by dissolving or dispersing a ceramic constituent material in a solvent or a dispersion medium. Adding a citric acid to the solution or dispersion mixture in which the ceramic constituents are dissolved or dispersed to prepare a mixture, and heat-treating the mixture at 100 to 500 ° C. for non-explosive oxidation. A step of forming an ultrafine ceramic oxide powder having a particle size of 1 μm or less and having a uniform particle size without scattering by causing a reduction combustion reaction, and forming the ultrafine ceramic oxide powder based on water or an organic solvent. Producing a ceramic sol solution by dissolving a ceramic constituent element having the same or a similar component as that of the ceramic powder; Mixing a sol solution to produce a ceramic paste, applying the ceramic paste to a diaphragm to form a piezoelectric / electrostrictive film, and forming the formed piezoelectric / electrostrictive film at 100 to 600 ° C. Heat treated,
Removing the solvent and allowing the ceramic sol to act as a reaction medium on the surface of the ceramic oxide particles to induce bonding between the ultrafine ceramic oxide powder particles. The molding method and the piezoelectric / electrostrictive film manufactured by the method are characterized.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

First, a method for producing an ultrafine ceramic oxide powder used as a raw material for producing a piezoelectric / electrostrictive film according to the present invention as shown in FIG. 1 will be described.

In the method for producing an ultrafine ceramic oxide powder according to the present invention, a ceramic constituent element material is sufficiently dissolved or uniformly dispersed in a solvent or a dispersion medium to produce a solution or dispersion mixture containing ceramic constituent elements. To do,
Preparing a solution or dispersion mixture in which the ceramic constituents are dissolved or dispersed, and performing an oxidation-reduction combustion reaction with the anion of the ceramic constituent element in the solution or dispersion mixture in which the ceramic constituents are dissolved or dispersed. Adding the required amount or more of citric acid to produce a mixture to produce a mixture;
A heat treatment at 00 ° C., and an additional heat treatment at 700 to 900 ° C. to improve crystallinity.

As raw materials containing ceramic constituents,
An oxide of a ceramic constituent element, a salt of a ceramic constituent element such as a carbonate or a nitrate and an organic or inorganic substance, or a body of a ceramic constituent element is used.

As the ceramic constituent element, lead (P
b) It is preferable to use a piezoelectric / electrostrictive ceramic element having titanium (Ti) as a basic constituent element.

In particular, the ceramic constituent elements include:
Lead (Pb), zirconium (Zr), titanium (Ti),
Or, lead (Pb), zirconium (Zr), titanium (T
i) / lead (Pb), magnesium (Mg), niobium (N
It is preferred to use one consisting of components containing b).

As the solvent or dispersion medium for dissolving or dispersing the ceramic constituent material, one or more of water or an organic solvent capable of dissolving or dispersing the raw material containing the ceramic constituent is selected. To use. Dimethylformamide (dime
thyl formamide), methoxyethanol (methoxyethan)
ol), acetic acid, alcohols and the like are mainly used.

As the combustion aid, citric acid which is an organic compound capable of causing a combustion reaction is used. In a conventional method, citric acid is a kimono-forming agent that is not a combustion aid and is used to impart homogeneity to the reaction, and the Petini method (Pechin
It can be applied to processes such as i process, and use the flammability and kimono forming effects of citric acid to induce a controlled combustion reaction.

Citric acid is added to and mixed with a solution or dispersion mixture in which the ceramic constituents are dissolved or dispersed to produce a mixture. As the amount of citric acid to be added, an amount required to cause an oxidation-reduction combustion reaction with the anion of the ceramic constituent element or more is added. The progress of the reaction can be controlled by the amount of citric acid added.

The mixed solution containing citric acid was mixed with 10
Heat treatment at 0-500 ° C. As the temperature of the heat treatment increases, the crystallinity of the ceramic phase improves, but even when the heat treatment temperature is only 100 ° C. or more, the combustion reaction of citric acid can sufficiently start, and even when the heat treatment is performed at 500 ° C. or more, the reaction is continued. Although possible, heat treatment at a higher temperature is meaningless compared to conventional methods.

More preferably, the heat treatment is performed at a temperature of 150 to 300 ° C. This temperature range is a heat treatment at a considerably low temperature, but the crystallinity of the ceramic phase can be appropriately secured.

The citric acid is removed during the combustion reaction,
The ceramic oxide is formed without scattering due to the reaction heat of the citric acid generated at this time.

In such a reaction, the other components of the ceramic constituent elements are removed by a combustion reaction for a sufficient time, so that a pure form of ceramic oxide powder containing no impurities is formed.

The ceramic oxide powder produced by the above method has a particle size of 1 μm or less, particularly 0.01 to 0.1 μm.
m, a very fine powder having a uniform particle size distribution, in which the basic particles are independent or weak aggregates (soft aggregat
Since it is present in the form of e) and is a completely burned ceramic, the additional heat treatment does not reduce the weight.

Further, since the surface has excellent reactivity and can be formed only by heat treatment at a low temperature, the degree of freedom of the diaphragm is high, and various printing methods can be applied to the diaphragm.

In order to improve the crystallinity of the manufactured ultrafine ceramic oxide powder, the method may further include a step of further heat-treating the manufactured ultrafine ceramic oxide powder at 700 to 900 ° C.

A method of forming a piezoelectric / electrostrictive film at a low temperature using the ultrafine ceramic oxide powder manufactured as described above will be described. The low-temperature forming process of the piezoelectric / electrostrictive film according to the present invention is as shown in FIG.

The ceramic paste is produced by mixing a ceramic oxide powder and a ceramic sol solution produced by dissolving ceramic constituent elements of the same or similar components having an affinity for the ceramic oxide powder.

As a ceramic oxide powder, it is effective to use a fine powder in order to secure a system capable of low-temperature molding in consideration of the reactivity of the ceramic oxide powder itself. The used ceramic oxide powder is used.

It is preferable to use an ultrafine ceramic oxide containing lead (Pb) and titanium (Ti) as basic constituent elements, and particularly to use an oxide made of a component containing lead, zirconium and titanium. preferable.

At room temperature, the surface of the ultrafine ceramic oxide powder is present in combination with more than one layer of water, wherein the water bound to the surface affects the acidity and basicity of the ceramic oxide powder surface. And acts as a catalyst when the ceramic oxide powder and the ceramic sol solution are mixed.

The ceramic sol solution is produced by dissolving ceramic constituent elements based on water or an organic solvent. Although various organic solvents can be used as a base, it is preferable to use mainly organic solvents selected from acetic acid, dimethylformamide, methoxyethanol, glycols and alcohols.

The ceramic constituent elements used in producing the ceramic sol solution are lead (Pb), zirconium (Z
r), it is preferable to use a component containing titanium (Ti), and the concentration of the ceramic sol solution used is 0.1 to 5
M is preferable.

When the ultrafine ceramic oxide powder and the ceramic sol solution are mixed, the content of the ceramic sol solution is 10 to 200 with respect to the ultrafine ceramic oxide powder.
It is preferable to use parts by weight. If the content of the ceramic sol solution is 200 parts by weight or more, the ultrafine ceramic oxide powder is excessively diluted and the viscosity of the mixture is low,
When the amount is less than 10 parts by weight, the amount of the ultrafine ceramic oxide powder is large and the viscosity becomes excessively high.

When both systems of the ultrafine ceramic oxide powder and the ceramic sol solution are mixed, the liquid ceramic sol solution uniformly coats the surface of the solid ceramic oxide powder and connects the ultrafine ceramic oxide powder particles. This effectively fills the gaps between the powders.

In the powder-sol mixture thus formed, the ultra-fine ceramic oxide powder having the specific properties of ceramic is surrounded by a ceramic sol solution of the same or similar components, so that it is suitable. The ceramic sol has excellent fluidity and acts as a reaction medium on the surface of the ultrafine ceramic oxide powder to improve the reactivity of the powder surface.

The organic component contained in the sol ensures the stability of the contact interface when the mixture comes into contact with another organic substance, and imparts dispersibility and homogeneity.

In such a system, a sol is thermally decomposed at a low temperature and converted into a composition identical or similar to that of the ultrafine ceramic oxide powder, so that a ceramic having improved connectivity between particles even at a low temperature is used. You can get the system.

In order to ensure the stability of the mixture of the ultrafine ceramic oxide powder and the ceramic sol solution and the fluidity required for molding, an organic solvent for adjusting physical properties may be added. As the organic solvent for adjusting physical properties, various ones can be used, but it is preferable to use glycols or alcohols having any viscosity and low vapor pressure at normal temperature.

When an organic solvent for adjusting physical properties is added to a mixture of the ultrafine ceramic oxide powder and the ceramic sol solution, the amount of the organic solvent for adjusting physical properties is 1 to 100% by weight based on the ultrafine ceramic oxide powder. It is preferable to use a part. When the amount of the organic solvent for adjusting physical properties is less than 1 part by weight, there is no effect of adding the organic solvent for adjusting physical properties, and when the amount exceeds 100 parts by weight, the mixture can maintain viscosity. In other words, it is excessively diluted, resulting in poor moldability during molding.

The addition amount of the organic solvent for adjusting the physical properties is particularly preferably 10 to 40 parts by weight based on the ultrafine ceramic oxide powder. The effect of addition can be exerted.

In order to improve the dispersibility and homogeneity of a mixture obtained by adding a solvent for adjusting physical properties to a mixture of a ceramic oxide powder and a ceramic sol solution, a small amount of an organic substance may be added. In this case, it is preferable to use a long-chain alcohol or a polar organic solvent as the organic substance to be added.

It is preferable to use pentanol or hexanol as the long-chain alcohol, and it is preferable to use acetylacetone or methoxyethanol as the polar organic solvent.

The amount of the organic substance to be added is preferably 1 to 50 parts by weight based on the ultrafine ceramic oxide powder.
This is because if the amount of the organic substance is less than 1 part by weight, there is no effect of adding the organic substance, and if the amount exceeds 50 parts by weight, the mixture cannot maintain the viscosity and is diluted too much to form. This is because the sex becomes worse.

The addition amount of the organic substance is particularly preferably 10 to 40 parts by weight with respect to the ultrafine ceramic oxide powder, and within this addition amount, the viscosity of the mixture is appropriately maintained and the effect of the addition of the organic substance is reduced. I can play.

The piezoelectric paste produced by the above method is applied to a diaphragm by a printing method, a molding method or a coating method to form a piezoelectric / electrostrictive film.

As the diaphragm, a high molecular organic compound such as metal, resin, or ceramic can be used.

Nickel or stainless steel is mainly used as the metal, polyester, polyimide or Teflon-based resin is mainly used as the high molecular organic compound of the resin, and aluminum oxide (Al ₂ O ₃₎ is used as the ceramic. O ₃ ), zirconium oxide (Zr
O ₂ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ),
Use silicon dioxide (SiO ₂ ) or glass system.

The piezoelectric / electrostrictive film formed on the diaphragm is 100
Heat treatment at ~ 600 ° C. The solvent is removed by this heat treatment, and the ceramic sol acts as a reaction medium on the surface of the oxide particles to induce bonding between the ultrafine ceramic oxide particles.

The reason that the reaction is sufficient only by a low-temperature heat treatment at 100 to 600 ° C. is because the water on the surface of the ultrafine ceramic oxide powder hydrolyzes the ceramic sol solution and the ceramic sol solution released by hydrolysis is separated from the ceramic sol solution. This is because a reaction equivalent to sintering is performed by a mutual reaction between the constituent raw materials and the ultrafine ceramic oxide powder. Further, the added organic substance is also removed during the heat treatment process.

More preferably, the heat treatment is carried out at a temperature of 150 to 300 ° C., and the crystallinity and the formability of the piezoelectric / electrostrictive film can be appropriately secured while the heat treatment is performed at a considerably low temperature.

When a printing method or a molding method is used when applying the ceramic paste to the diaphragm, the thickness of the formed piezoelectric / electrostrictive film can be adjusted by adjusting the thickness of the screen or the mold. Therefore, a piezoelectric / electrostrictive film from a thin film form to a thick film form can be freely formed.

When the coating method is used, a film can be formed on the diaphragm as a whole and then processed, and a piezoelectric / electrostrictive film having a desired pattern can be formed by masking. It is. The thickness of the formed film is adjusted by repeating the process of forming the film on the diaphragm and performing the heat treatment.

The method may further include drying the formed film after applying the ceramic paste to the diaphragm and before performing the heat treatment. At this time, drying is performed at 70 to 150 ° C.
It is preferable to carry out in.

Although the piezoelectric / electrostrictive film manufactured by such a method is heat-treated at a low temperature, it has excellent characteristics inherent in ceramics, and controls the thickness of the formed piezoelectric / electrostrictive film. Accordingly, it is possible to form a piezoelectric / electrostrictive film in a thin film form to a piezoelectric / electrostrictive film in a thick film form.

Thus, only by the low-temperature heat treatment,
Since the piezoelectric / electrostrictive film can be formed without limitation of the film thickness, its applicability is high.

Further, since it is not necessary to add an organic substance such as a dispersant, it is not necessary to go through a step of removing the binder at a temperature of 500 ° C. or more before the heat treatment. Can be formed.

[0065]

The present invention will be described below in detail with reference to examples. However, the following examples are illustrative of the invention and do not limit the scope of the invention.

Example 1 Pb (Zr _0.52 Ti _0.48 )
20 g of _0.60 (Mg _0.32 Nb _0.67 ) _0.40 O ₃ powder was mixed with 8 g of PZT (52/48) sol based on acetic acid and stirred in an agate mortar for 15 minutes to produce a paste.
The prepared paste was printed on a SUS (stainless steel) 316L vibrating plate having a thickness of 30 μm, on which a fine pattern produced by a SUS plate was placed.

After drying at 70 ° C. for 10 minutes, heat treatment was performed at 150 ° C. for 2 hours. Aluminum was sputtered on the formed piezoelectric / electrostrictive film to form an upper electrode, a potential was applied, and the displacement of the diaphragm due to the piezoelectric phenomenon was measured.

The piezoelectric characteristics appearing as the displacement of the diaphragm were superior to those of the piezoelectric / electrostrictive films manufactured by the conventional method.

(Example 2) PZT (52/48) powder 3
g with 1.2 g of acetic acid based PZT (52/48) sol, 0.3 g of triethylene glycol,
The mixture was stirred in an automatic mortar for 1 hour to produce a paste.

The produced paste was mixed with S using a fine pattern produced on a 250 mesh steel screen.
Printing was performed on US316L diaphragm and alumina diaphragm, dried at 70 ° C. for 10 minutes, and then heat-treated at 300 ° C. for 2 hours.

A silver paste was printed and heat-treated at 300 ° C. to form an upper electrode, a potential was applied, and the displacement of the diaphragm due to the piezoelectric phenomenon was measured.

The piezoelectric characteristics appearing as the displacement of the vibration plate were superior to those of a piezoelectric / electrostrictive film manufactured by a conventional method.

(Example 3) PZT (52/48) powder 3
g was mixed with 1.2 g of acetic acid-based PZT (52/48) sol, 0.3 g of triethylene glycol, and 0.12 g of 1-pentyl alcohol, and stirred in an automatic mortar for 1 hour to produce a paste.

The produced paste was mixed with a fine pattern prepared on a 250-mesh steel screen using a fine pattern.
After printing on US316L diaphragm and alumina diaphragm, it was dried at 70 ° C. for 10 minutes and heat-treated at 300 ° C. for 2 hours.

The upper electrode was formed by sputtering gold, a potential was applied, and the displacement of the diaphragm due to the piezoelectric phenomenon was measured.

The piezoelectric characteristics appearing as the displacement of the vibration plate were superior to those of a piezoelectric / electrostrictive film manufactured by a conventional method.

(Example 4) PZT (52/48) powder 3
g was mixed with 1.2 g of acetic acid-based PZT (52/48) sol, 0.3 g of triethylene glycol, and 0.12 g of 1-pentyl alcohol, and stirred in an automatic mortar for 1 hour to produce a paste.

A mold was formed from a photosensitive film on a nickel diaphragm having a thickness of 10 μm, and the mold was adhered to the mold and filled with the produced ceramic paste.

After heat-treating this sample in air at 300 ° C. for 2 hours, aluminum was vacuum-deposited on the upper electrode, a potential was applied, and the displacement of the diaphragm due to the piezoelectric phenomenon was measured.

The piezoelectric characteristics appearing as the displacement of the diaphragm were superior to those of the piezoelectric / electrostrictive films manufactured by the conventional method.

Example 5 Lead acetate [Pb (CH ₃ CO ₃ )
O _2)] 196 g was dissolved in glacial acetic acid 250 ml, wherein the zirconium propoxide [Zr (n-C ₃ H
₇ O) ₄ ] 117 ml and titanium isopropoxide [Ti
_{(I-C 3 H 7 O} ) 4] was added 73 ml. After mixing for 30 minutes at room temperature, the solution was transferred to a round bottom flask and
After refluxing for 2 hours at 0 ° C.,
An M concentration of PZT (52/48) sol was prepared.

A ceramic paste was prepared by mixing PZT / PMN (60/40) fine powder, the acetic acid-based 2M PZT (52/48) sol, and trimethylene glycol. At this time, the fine powder and the liquid phase component (sol, trimethanol glycol) were mixed at a weight ratio of 40:60.

The produced ceramic paste was spin-coated on a nickel substrate, and the coated substrate was placed in a drying chamber and dried at 130 ° C.

By repeating the process of coating and drying,
After adjusting the thickness of the formed film, the film was dried at 130 ° C. for 1 hour and heat-treated at 200 ° C. for 2 hours to produce a piezoelectric / electrostrictive film.

(Embodiment 6) PZT / PMN (60/4)
0) 0.5M based on fine powder and methoxyethanol
PZT (52/48) sol was mixed to produce a ceramic paste. At this time, the fine powder and the sol were mixed in a ratio of 50:50.
At a weight ratio of

After the produced ceramic paste was spin-coated on a nickel substrate, it was placed in a drying chamber and dried at 130 ° C.

The above process was repeated to adjust the thickness of the formed film, dried at 130 ° C. for 1 hour, and heat-treated at 200 ° C. for 1 hour to produce a piezoelectric / electrostrictive film.

(Example 7) A 2M PZT (52/48) dimethylformamide-based sol was spin-coated on a SUS substrate and then dried at 130 ° C for 1 hour. On a dried substrate, PZT / PMN (40/60) fine powder is mixed with nitric acid based 2M PZT (52/48) sol,
A ceramic paste mixed with trimethylene glycol was spin coated. At this time, the fine powder and the liquid phase component (sol, trimethylene glycol) were mixed at a weight ratio of 60:40.

The resultant was dried at 130 ° C. for 1 hour and heat-treated at 300 ° C. for 2 hours to produce a piezoelectric / electrostrictive film.

Example 8 A fine pattern is formed on a SUS substrate using a photosensitive film as a mold. Substrate is dimethylformamide based 2M PZT (52/48)
It was immersed in a sol, dip coated, and dried at 130 ° C. for 1 hour.

The substrate was immersed in a ceramic paste in which PZT / PMN (40/60) fine powder was mixed with nitric acid base 2M PZT (52/48) sol and trimethylene glycol, and dip coated. At this time, the fine powder and the liquid phase component (sol, trimethylene glycol)
The mixture was mixed at a weight ratio of 0:30.

After drying at 130 ° C. for 1 hour and heat treatment at 300 ° C. for 2 hours, a piezoelectric / electrostrictive film was produced.

[0093]

According to the present invention described above, the piezoelectric / electrode is formed only by a low-temperature heat treatment without using a separate binder process, using an ultra-fine ceramic oxide powder having fine particles and excellent surface reactivity. A strain film can be formed.

Also, when the piezoelectric / electrostrictive film is formed using the ceramic paste, the piezoelectric characteristics appearing as the displacement of the diaphragm are superior to the existing results despite the low temperature treatment. The manufacturing process has been simplified,
The process of manufacturing the piezoelectric / electrostrictive film using this is energy-saving, and there is an effect that the lead-time of the process is significantly reduced.

[Brief description of the drawings]

FIG. 1 is a process chart showing a process for producing an ultrafine ceramic oxide powder used in the present invention.

FIG. 2 is a process diagram showing a conventional piezoelectric / electrostrictive film forming process.

FIG. 3 is a process diagram showing a forming step of a low-temperature forming method of a piezoelectric / electrostrictive film according to the present invention.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H01L 41/24 H01L 41/22 A (56) References JP-A 64-56320 (JP, A) JP-A 64-24017 ( JP, A) JP-A-7-302706 (JP, A) JP-A-8-91809 (JP, A) Mater. Chem. 7 [9] (1997) p1815-1820 (58) Fields investigated (Int. Cl. ⁷ , DB name) C01B 13/14 C01B 13/32 C01G 25/00 C01G 33/00 C04B 35/49 H01L 41/24 CA (STN)

Claims (36)

(57) [Claims] A step of dissolving or dispersing the ceramic component material in a solvent or a dispersion medium to produce a solution or a dispersion mixture containing the ceramic component material; and a solution or a solution in which the ceramic component is dissolved or dispersed. Adding citric acid to the dispersion mixture to produce a mixture; and heat treating the mixture at 100-500 ° C. to cause a non-explosive oxidation-reduction combustion reaction, so that the particle size is 1 μm or less. Forming an ultrafine ceramic oxide powder having a uniform particle size distribution without scattering, and dissolving ceramic constituent elements having the same or similar components as the ultrafine ceramic oxide powder based on water or an organic solvent. Preparing a ceramic sol solution; mixing the ultra-fine ceramic oxide powder and the ceramic sol solution to prepare a ceramic paste; Forming a piezoelectric / electrostrictive film by applying the ceramic paste to a substrate; heat treating the formed piezoelectric / electrostrictive film at 100 to 600 ° C. to remove a solvent; Forming a bond between the ultrafine ceramic oxide powder particles by acting as a reaction medium on the surface of the ceramic oxide particles, thereby forming a piezoelectric / electrostrictive film at a low temperature. 2. The method of claim 1, further comprising a step of drying the formed film between the step of forming the film and the step of heat-treating. 3. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 2, wherein the formed film is dried at 70 to 150 ° C. 4. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 1, wherein the substrate is made of a high molecular organic compound such as a metal, a resin, or a ceramic. 5. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 4, wherein the metal is nickel or stainless steel. 6. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 4, wherein the high molecular weight organic compound of the resin is a polyester-based, polyimide-based or Teflon-based resin. 7. The ceramic film is made of aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon dioxide (S
iO ₂₎ or claim 4, characterized in that the glass-based
A low-temperature forming method of the piezoelectric / electrostrictive film according to the above. 8. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 1, wherein a printing method is used when forming the film by applying the ceramic paste to the substrate. 9. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 1, wherein a molding method is used when forming the film by applying the ceramic paste to the substrate. 10. The low-temperature forming method for a piezoelectric / electrostrictive film according to claim 1, wherein a coating method is used when forming the film by applying the ceramic paste to the substrate. 11. The piezoelectric device according to claim 1, wherein the ultrafine ceramic oxide comprises a component containing lead (Pb), zirconium (Zr), and titanium (Ti).
Low temperature forming method for electrostrictive film. 12. The method for forming a piezoelectric / electrostrictive film at a low temperature according to claim 1, wherein the temperature at which the formed film is heat-treated is 150 to 300 ° C. 13. dissolving or dispersing the ceramic constituent material in a solvent or a dispersion medium to produce a solution or a dispersion mixture containing the ceramic constituent material; and a solution or dispersion in which the ceramic constituent material is dissolved or dispersed. Adding citric acid to the dispersion mixture to produce a mixture; and heat treating the mixture at 100-500 ° C. to cause a non-explosive oxidation-reduction combustion reaction, so that the particle size is 1 μm or less. Forming an ultrafine ceramic oxide powder having a uniform particle size distribution without scattering, and dissolving ceramic constituent elements having the same or similar components as the ultrafine ceramic oxide powder based on water or an organic solvent. Producing a ceramic sol solution; mixing the ultrafine ceramic oxide powder and the ceramic sol solution to produce a ceramic paste. Forming a piezoelectric / electrostrictive film by applying the ceramic paste to a substrate; heat-treating the formed piezoelectric / electrostrictive film at 100 to 600 ° C. to remove a solvent; Acting as a reaction medium on the surface of the ceramic oxide particles so as to induce bonding between the ultrafine ceramic oxide powder particles. 14. The piezoelectric / electrostrictive film according to claim 13, further comprising a step of drying the formed film between the step of forming the film and the step of heat-treating. 15. The piezoelectric / electrostrictive film according to claim 14, wherein the formed film is dried at 70 to 150 ° C. 16. The piezoelectric / electrostrictive film according to claim 13, wherein the substrate is formed of a metal, a high molecular weight organic compound such as a resin, or ceramic. 17. The piezoelectric / electrode according to claim 16, wherein the metal is nickel or stainless steel.
Electrostrictive film. 18. The polymer organic compound of the resin,
17. The piezoelectric / electrostrictive film according to claim 16, wherein the film is a polyester-based, polyimide-based or Teflon-based resin. 19. The ceramic film is made of aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon dioxide (SiO ₂ ) or a glass-based material. The piezoelectric / electrostrictive film according to claim 16, wherein 20. The piezoelectric / electrostrictive film according to claim 13, wherein when the ceramic paste is applied to a substrate to form a film, a printing method is used. 21. The piezoelectric / electrostrictive film according to claim 13, wherein when the ceramic paste is applied to a substrate to form a film, a molding method is used. 22. The piezoelectric / electrostrictive film according to claim 13, wherein when the ceramic paste is applied to a substrate to form a film, a coating method is used. 23. The piezoelectric / electrostrictive film according to claim 13, wherein the ultrafine ceramic oxide is made of a component containing lead (Pb), zirconium (Zr), and titanium (Ti). 24. The piezoelectric / electrostrictive film according to claim 13, wherein a temperature at which the formed film is heat-treated is 150 to 300 ° C. 25. An ultra-fine particle produced by a non-explosive oxidation-reduction combustion reaction at a low temperature of 100 to 500 ° C., having a particle size of 1 μm or less and containing lead (Pb) and titanium (Ti) as basic constituent elements. Molded by applying a ceramic paste produced by mixing a ceramic sol solution of the same or similar component with a ceramic oxide powder and an ultrafine ceramic oxide powder produced based on water or an organic solvent, and applying the paste to a substrate. The solvent is removed by a heat treatment at 100 to 600 ° C., and the ceramic sol acts as a reaction medium on the surface of the ultrafine ceramic oxide powder to induce bonding between the ultrafine ceramic oxide particles to perform low-temperature molding. A piezoelectric / electrostrictive film characterized by being made possible. 26. The piezoelectric / electrostrictive film according to claim 25, further comprising a step of drying the formed film between the step of forming the film and the step of heat-treating. 27. The piezoelectric / electrostrictive film according to claim 26, wherein the formed film is dried at 70 to 150 ° C. 28. The piezoelectric / electrostrictive film according to claim 25, wherein the substrate is formed of a high molecular organic compound such as a metal, a resin, or a ceramic. 29. The piezoelectric device according to claim 28, wherein the metal is nickel or stainless steel.
Electrostrictive film. 30. The polymer organic compound of the resin,
29. The piezoelectric / electrostrictive film according to claim 28, which is a polyester-based, polyimide-based or Teflon-based resin. 31. The ceramic film is made of aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ), silicon dioxide (SiO ₂ ) or a glass-based material. The piezoelectric / electrostrictive film according to claim 28, wherein: 32. The piezoelectric / electrostrictive film according to claim 25, wherein a printing method is used when forming the film by applying the ceramic paste to the substrate. 33. The piezoelectric / electrostrictive film according to claim 25, wherein a molding method is used when the ceramic paste is applied to a substrate to form a film. 34. The piezoelectric / electrostrictive film according to claim 25, wherein a coating method is used when the ceramic paste is applied to a substrate to form a film. 35. The piezoelectric / electrostrictive film according to claim 25, wherein the ultrafine ceramic oxide comprises a component containing lead (Pb), zirconium (Zr), and titanium (Ti). 36. The piezoelectric / electrostrictive film according to claim 25, wherein the temperature at which the formed film is heat-treated is 150 to 300 ° C.