JP2014060282A - Manufacturing method of electromechanical conversion film, electromechanical conversion film, electromechanical conversion element, droplet discharge head, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an electromechanical conversion film that is economical because of a large amount of deposition per one deposition.SOLUTION: A manufacturing method of an electromechanical conversion film for manufacturing an electromechanical conversion film on at least a part of a ground comprises the steps of: causing a ground 51 to be subjected to surface modification to have a predetermined pattern; applying a sol-gel solution including fine particles having the same constitution as that of the electromechanical conversion film and a precursor of the electromechanical conversion film, to an area of the ground not subjected to the surface modification by an ink jet method; and heating the applied sol-gel solution. The average particle diameter of the fine particles is less than 1 μm.

Description

  The present invention relates to an electromechanical conversion film manufacturing method, an electromechanical conversion film, an electromechanical conversion element, a droplet discharge head, and an image forming apparatus.

  Devices such as a vibration sensor, a piezoelectric speaker, and various driving devices include an electromechanical conversion element in which electromechanical conversion films are stacked. In a driving device, for example, a liquid discharge head of an ink jet recording apparatus includes a nozzle that discharges ink droplets, a liquid chamber that communicates with the nozzle, and an electromechanical conversion element such as a piezoelectric element. By applying pressure, ink droplets are ejected from the nozzles.

  An example of a method for producing an electromechanical conversion element is a method in which a step of applying a precursor solution of an electromechanical conversion film on a base and then performing a heat treatment is repeated until a desired film thickness is obtained. In this method, the film thickness obtained by a single film formation is about 50 to 100 nm, and in order to obtain desired electromechanical conversion characteristics, it is necessary to undergo a plurality of repeated treatments.

  Therefore, in Patent Documents 1 and 2, the electromechanical conversion film having a large film formation amount per film formation is obtained by adding fine particles made of a metal oxide having the same composition as the electromechanical conversion film to the precursor solution. A method is disclosed.

  However, the manufacturing methods described in Patent Documents 1 and 2 use a spin coating method, and the precursor solution is applied to regions other than the region of the electromechanical conversion film to be finally formed. Therefore, the amount of the electromechanical conversion film formed with respect to the applied precursor solution is small, and the manufacturing cost may be increased.

  The present invention has been made in view of the above circumstances and problems, and an object of the present invention is to provide an economical method for producing an electromechanical conversion film with a large amount of film formation per film formation.

An electromechanical conversion film manufacturing method for manufacturing an electromechanical conversion film on at least a part of a substrate,
Modifying the surface of the base into a predetermined pattern;
Applying a sol-gel solution containing fine particles having the same composition as the electromechanical conversion film and a precursor of the electromechanical conversion film to an area of the base that is not surface-modified by an inkjet method;
Heating the applied sol-gel solution;
Including
An electromechanical conversion film manufacturing method is provided in which the average particle size of the fine particles is less than 1 μm.

  The amount of film formation per film formation is large, and an economical method for producing an electromechanical conversion film can be provided.

FIG. 1 is a schematic diagram showing an example of the structure of the droplet discharge head of this embodiment. FIG. 2 is a schematic diagram for explaining an embodiment in which a SAM film is patterned on a base. FIG. 3 is a schematic diagram for explaining another embodiment of patterning a SAM film on a base. FIG. 4 is a schematic diagram for explaining an embodiment in which an electromechanical conversion film is formed on a surface-modified base. FIG. 5 is a schematic diagram for explaining the landing state of the precursor solution in the first embodiment. FIG. 6 is an example of a PE hysteresis curve of the electromechanical transducer according to the first embodiment. FIG. 7 is a schematic view for explaining the ink jet recording apparatus of the present embodiment. FIG. 8 is another schematic diagram for explaining the ink jet recording apparatus of the present embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment and each example, components such as members and components having the same function or shape are given the same reference numerals as much as possible to avoid duplicate explanation. In addition, the content described in embodiment is only one form, and the scope of the present invention is not limited to this.

  In this embodiment, the “image forming apparatus” of the liquid discharge recording method forms an image by landing droplets on a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. The “image formation” means not only that an image having a meaning such as a character or a figure is imparted to the medium, but also an image having no meaning such as a pattern is imparted to the medium ( It also simply means that a droplet is landed on a medium).

  Furthermore, in the present embodiment, the “droplet” is not limited to what is referred to as ink, but includes what is referred to as recording liquid, fixing processing liquid, resin, liquid, and the like, and image formation can be performed. It is used as a generic term for all liquid droplets that can be made into fine droplets. The term “recording medium” does not limit the material to paper, but also includes OHP sheets, cloth, etc., and means that the droplets adhere to it, and can be used as a recording medium, recording paper, recording paper, etc. It is used as a general term for anything from what is called thin paper to thick paper, postcard, envelope, or simply paper. Further, the image is not limited to a two-dimensional image, and includes a three-dimensional image.

  The present embodiment includes an electromechanical conversion element including an electromechanical conversion film, a droplet discharge head including the electromechanical conversion element, and an image forming apparatus including the droplet discharge head. The above-described image forming apparatus is generally called an ink jet recording apparatus. Note that specific configuration examples of the droplet discharge head and the image forming apparatus will be described in detail in an embodiment described later.

  The ink jet recording apparatus has many advantages such as low noise, high-speed printing, and the use of plain paper, which is an inexpensive recording medium with a high degree of ink freedom. Therefore, it is widely used as an image recording apparatus or an image forming apparatus such as a multi-function machine having a plurality of image forming functions such as a printer, a facsimile, a copying apparatus, and a plotter.

  A droplet discharge device used in an inkjet recording apparatus includes a nozzle that discharges ink droplets, a liquid chamber (also referred to as a discharge chamber, a pressure chamber, a pressure chamber, an ink flow path, and the like) that communicates with the nozzle, a liquid Pressure generating means for discharging the ink in the chamber.

  In this embodiment, the pressure generating means is a piezo type that discharges ink droplets by deforming a diaphragm that forms the wall surface of the liquid chamber using an electromechanical transducer such as a piezoelectric element. In the present embodiment, the piezoelectric pressure generating means includes a lateral vibration (bend mode) type utilizing deformation in the d31 direction.

(Droplet ejection head)
As described above, the electromechanical conversion film of this embodiment can be applied to an electromechanical conversion element and a droplet discharge head including the electromechanical conversion element. An embodiment in which the electromechanical conversion film of this embodiment is applied to a droplet discharge head will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing an example of the structure of the droplet discharge head of this embodiment.

  A droplet discharge head 10 used in an ink jet recording apparatus includes a nozzle plate 12 in which nozzle holes 11 for discharging ink droplets are formed, and a liquid chamber 21 (an ink flow path, a pressurized liquid chamber, A pressurizing chamber, a discharge chamber, and a pressure chamber), an electromechanical conversion element 40 that pressurizes ink in the pressurizing chamber, and a diaphragm 30 that forms the wall surface of the ink flow path. The liquid chamber 21 is formed by the nozzle plate 12, the liquid chamber substrate 20, and the vibration plate 30. The electromechanical conversion element 40 includes a first electrode 42, an electromechanical conversion film 43, and a second electrode 44, and the liquid chamber 21 includes a pressure chamber substrate 20, a vibration plate 30, and a nozzle plate 12. Composed. In response to the energy generated by the energy generating means, the vibration plate 30 is deformed and displaced, for example, in the lateral direction (d31 direction) and pressurizes the ink in the pressure chamber 21 to eject ink droplets from the nozzles.

Further, in order to improve the adhesion between the first electrode 42 and the diaphragm 30, for example, Ti, TiO ₂ , TiN, Ta, Ta ₂ O ₅ , Ta ₃ N _5, etc. are adhered on the diaphragm 30. A layer 41 may be provided.

  1 describes an example in which the electromechanical conversion film of this embodiment is applied to a droplet discharge head, but the present invention is not limited in this respect. The electrical conversion element including the electromechanical conversion film of the present embodiment may be used in applications such as a micropump, an ultrasonic motor, an acceleration sensor, a projector biaxial scanner, an infusion pump, and the like.

  The electromechanical conversion element 40 is disposed on the side facing the nozzle plate 12 and deforms and displaces the vibration plate 30 constituting the wall surface of the liquid chamber 21, so that the ink in the liquid chamber 21 is ejected from the nozzle hole 11 as an ink droplet. This is a piezo-type electromechanical transducer to be discharged. The electromechanical transducer 40 is deformed and displaced when a voltage is applied between the first electrode 42 and the second electrode 44.

(Electromechanical conversion membrane)
In this embodiment, examples of the material of the electromechanical conversion film 43 include PZT (solid solution of lead zirconate (PbZrO ₃ ) and lead titanate (PbTiO ₃ )) or BT (barium titanate (BaTiO ₃ )). It is done.

As PZT, for example, the ratio of PbZrO ₃ and PbTiO ₃ is 53:47, and the chemical formula indicates Pb (Zr _0.53 , Ti _0.47 ) O ₃ , generally PZT (53/47). PZT can be used. The characteristics of PZT vary depending on the ratio of PbZrO ₃ and PbTiO ₃ .

When PZT is used as the electromechanical conversion film, lead acetate, a zirconium alkoxide compound, and a titanium alkoxide compound are used as starting materials, and dissolved in methoxyethanol as a common solvent to prepare a PZT precursor solution. The mixing amount of the lead acetate, zirconium alkoxide compound, and titanium alkoxide compound can be appropriately selected by those skilled in the art depending on the desired composition of PZT (ratio of PbZrO ₃ and PbTiO ₃ ).

  Note that the metal alkoxide compound is easily decomposed by moisture in the atmosphere. Therefore, stabilizers such as acetylacetone, acetic acid and diethanolamine may be added to the PZT precursor solution as stabilizers.

Examples of composite oxides other than PZT include barium titanate. In this case, it is also possible to prepare a barium titanate precursor solution by dissolving barium alkoxide and a titanium alkoxide compound in a common solvent. is there. These materials are described by the general formula ABO ₃ and correspond to composite oxides containing A = Pb, Ba, Sr B = Ti, Zr, Sn, Ni, Zn, Mg, and Nb as main components. The specific description is expressed as (Pb _1-x , Ba) (Zr, Ti) O ₃ , (Pb _1-x , Sr) (Zr, Ti) O ₃ , This is a case where the part Ba or Sr is substituted. Such substitution is possible with a divalent element, and the effect thereof has an effect of reducing characteristic deterioration due to evaporation of lead during heat treatment.

  In the present embodiment, fine particles containing a metal oxide having the same composition as the electromechanical conversion film to be manufactured are mixed in the above-described electromechanical conversion film precursor solution. As a specific example, when PZT is adopted for the electromechanical conversion film, PZT fine particles are mixed in the PZT precursor solution, and when BT is adopted, BT fine particles are mixed in the BT precursor solution. By containing fine particles containing a metal oxide having the same composition as the electromechanical conversion film to be produced in the precursor solution, it is possible to suppress the occurrence of cracks in the resulting electromechanical conversion film and improve the density. . This is because the mixed fine particles absorb the shrinkage of the precursor solution and can impart fluidity to the fine particles in the precursor solution.

  In film formation by a normal sol-gel method, since the precursor solution has a high shrinkage rate, the film thickness that can be formed by one film formation is around 100 nm in order to form the electromechanical conversion film without generation of cracks. It was. However, in this embodiment, since the solid content concentration in the precursor solution can be increased, the film thickness that can be formed at a time is as large as about 1 to 3 μm.

  In the present embodiment, the average particle size of the fine particles mixed in the precursor solution is preferably less than 1 μm. As will be described later, in this embodiment, the precursor solution is applied by an inkjet method. In the application of the precursor solution by the ink jet method, the ejection stability of the precursor solution is important. Specifically, the nozzle diameter of the droplet discharge head of the conventional ink jet recording apparatus is about φ15 to 30 μm. When the average particle diameter of the fine particles to be mixed is 1 μm or more, the liquid droplets may bend in the landing direction when the coating liquid is discharged, or the nozzle holes may be clogged. That is, the precursor solution cannot be stably discharged, and an electromechanical conversion film having a desired pattern may not be formed.

  The fine particles to be mixed may be particles having a monodisperse particle size distribution, but may also be particles having a particle size distribution, and preferably include, for example, fine particles having a particle size of 20 nm or less. Preferably having a particle size distribution from 1 to 1000 nm. For example, by including fine particles having a particle size of 20 nm or less (for example, 5 nm), a gap generated when fine particles having a particle size of 100 nm or more aggregate during sintering and crystallization can be filled. Therefore, generation | occurrence | production of a crack can be suppressed and a precise | minute electromechanical conversion film can be manufactured.

  In addition, the precursor solution usually contains components that are easily hydrolyzed by moisture in the atmosphere. Therefore, it is preferable to add acetylacetone, acetic acid, diethanolamine or the like as a stabilizer for suppressing hydrolysis.

(First electrode and second electrode)
As the material of the first electrode, a metal material such as a noble metal having high heat resistance and forming a SAM (Self Assembled Monolayer) film by reaction with alkanethiol shown below is used. It is preferable to do. Specifically, platinum (Pt), gold (Au), silver (Ag), copper (Cu), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium having high reactivity with the SAM material. A single metal such as (Os) or iridium (Ir), or an alloy material containing these metals can be used.
Moreover, after producing these metal layers, it is also possible to laminate | stack and use a conductive oxide layer. As the conductive oxide, specifically, there is a composite oxide described by the chemical formula ABO ₃ and having A = Sr, Ba, Ca, La, B = Ru, Co, Ni as main components, and SrRuO ₃ And CaRuO ₃ , (Sr _1-x Ca _x ) O ₃ which is a solid solution thereof, LaNiO ₃ and SrCoO ₃ , and further, (La, Sr) (Ni _1-y Co _y ) O ₃ which is a solid solution thereof. (Y may be 1). Other oxide materials include IrO ₂ and RuO ₂ .

  The first electrode can be manufactured by a method such as a sputtering method or a vacuum film forming method such as vacuum deposition.

  Further, as the material of the second electrode, a material such as a metal having high heat resistance similar to the lower electrode can be used. The second electrode can be manufactured by a method such as a sputtering method or a vacuum film formation method such as vacuum deposition.

(Diaphragm)
Since the first electrode is electrically connected as a common electrode when a signal is input to the electromechanical transducer, the diaphragm 30 under the first electrode can be an insulator or a conductor subjected to insulation treatment.

  As a specific material of the vibration plate 30, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a film in which these films are stacked having a thickness of about several microns can be used. In addition, a ceramic film such as an aluminum oxide film or a zirconia film in consideration of a difference in thermal expansion can also be used.

  As a method for forming the diaphragm, for example, the silicon-based insulating film can be obtained by CVD or thermal oxidation treatment of the silicon-based film. The metal oxide film can be formed by a sputtering method or the like.

(Method for producing electromechanical conversion film)
The method for producing an electromechanical conversion film of the present embodiment is a method for producing an electromechanical conversion film for producing an electromechanical conversion film on at least a part of a base,
Modifying the surface of the base into a predetermined pattern;
Applying a sol-gel solution containing fine particles having the same composition as the electromechanical conversion film and a precursor of the electromechanical conversion film to an area of the base that is not surface-modified by an inkjet method;
Heating the applied sol-gel solution;
including.

  In the present embodiment, an embodiment in which a PZT film is manufactured as an electromechanical conversion film will be described with reference to the drawings.

[Process for surface modification]
First, a surface treatment method for a base for producing an electromechanical conversion film will be described.

  FIG. 2 is a schematic diagram for explaining an embodiment in which a SAM film is patterned on a base.

  FIG. 2A shows a base 51 that is a first electrode, for example. In this embodiment, platinum (Pt) is used as the first electrode.

  A dipping process is performed on the base 51 using a SAM material made of alkanethiol or the like (FIG. 2B). Thereby, the SAM material reacts on the surface of the base 51 and the SAM film 52 adheres, and the surface of the base 51 can be made water repellent. Alkanethiol differs in reactivity and hydrophobicity (water repellency) depending on the molecular chain length, but a SAM material usually has 6 to 18 carbon atoms. The SAM material is prepared by diluting alkanethiol with a solvent such as alcohols in which the alkanethiol is dissolved and does not cause a chemical reaction. The concentration of alkanethiol is preferably about several millimoles / liter to several moles / liter.

  After a predetermined time, the base 51 is taken out, and the surplus molecules are washed by substitution with a solvent and dried.

  Next, a photoresist 53 is patterned by known photolithography (FIG. 2C). Thereafter, the SAM film is removed by dry etching, the photoresist 53 is removed, and the patterning of the SAM film is completed (FIG. 2D).

  In addition, a photoresist pattern is first formed from the state of FIG. 2A (FIG. 2B ′), SAM treatment is performed (FIG. 2C ″), and the resist is removed to remove the SAM. The film 52 may be patterned.

  In addition, the SAM film 52 in the exposed portion is removed by irradiating the base surface with ultraviolet rays or oxygen plasma through the photomask 54 from the state of FIG. 2B (FIG. 2C ′). Then, the SAM film 52 may be patterned.

  Note that the surface of the region where the SAM film remains after patterning is hydrophobic. On the other hand, in the region where the SAM film is removed by dry etching or the like and the surface is an electrode material, the surface becomes hydrophilic. Using this surface energy contrast, the PZT precursor liquid described in detail below can be applied separately.

  In addition, in FIG. 2, the embodiment in which the SAM film is patterned on the base 51 which is the first electrode of Pt has been described. However, as described above, the material of the first electrode is not limited to a metal such as Pt. Here, the case where the above-described metal layer and the lanthanum nickelate (LNO) layer that is an oxide are stacked and used as the material of the first electrode will be described as an example.

  FIG. 3 is a schematic diagram for explaining another embodiment for patterning a SAM film on a base. As shown in FIG. 3A, in the initial state, the base 51 has a structure in which a Pt layer, an LNO layer, and a Pt layer are stacked on the substrate 30 as the first electrode 42. Next, as shown in FIG. 3B, patterning is performed by a photolithography process and an etching process, thereby removing the Pt layer on the side different from the side on which the base exists. By this step, a region where the LNO layer is exposed and a region where the Pt layer remains can be formed. The SAM material has high reactivity with the Pt layer, but low reactivity with the LNO layer. Therefore, by performing the above-described SAM treatment in this state, as shown in FIG. 3C, a SAM film is formed only on the Pt layer and becomes hydrophobic, while a SAM film is formed on the LNO layer. Not hydrophilic.

[Coating step and irradiating step]
Next, a process of forming an electromechanical conversion film by repeatedly applying a sol-gel solution on the surface-modified first electrode and performing heat treatment will be described.

  FIG. 4 is a schematic diagram for explaining an embodiment in which an electromechanical conversion film is formed on a surface-modified base.

  In the surface-modified base described with reference to FIG. 2, the region where the photoresist remains by photolithography becomes hydrophobic because the patterned SAM film remains even after the resist is removed. On the other hand, in the region where the photoresist has been removed by photolithography, the SAM film is removed by dry etching and the surface is an electrode material, so the surface is hydrophilic (FIG. 4A). Thereafter, a sol-gel solution 56 containing a PZT precursor and PZT fine particles is applied onto the base by an inkjet recording head 55 (FIG. 4B). The sol-gel liquid 56 is preferably adjusted in advance in terms of viscosity, surface tension, and the like so that it can be applied by the inkjet recording head 55. In FIG.4 (b), the application | coating area | region of a sol-gel liquid becomes only a hydrophilic area | region by the contrast of surface energy. By discharging the sol-gel liquid only to the hydrophilic surface area, the amount of the sol-gel liquid to be applied can be reduced as compared with a conventional process such as a spin coating method, and the process can be simplified.

  After applying the sol-gel solution by the ink jet method, the applied sol-gel solution is heated (heat treatment). The method of heating the applied sol-gel solution is not particularly limited, and for example, a method of heating directly from the lower surface side of the substrate using a hot plate, a method of heating indirectly using an infrared lamp, or the like, irradiation with laser light. The method etc. are mentioned. As a method of indirectly heating using an infrared lamp or the like, specifically, a method of irradiating infrared rays using an infrared lamp from the lower surface side of the substrate or a pair of infrared lamps so as to sandwich the substrate, The method of irradiating infrared rays from both the upper surface side (sol-gel liquid film side) and the lower surface side of the substrate can be mentioned. Among these, for example, as shown in FIG. 4C, it is preferable to employ a method of irradiating the interface between the precursor solution and the first substrate with laser light.

  In heating the sol-gel solution, after applying the precursor solution, a step of drying the solvent component, a step of thermally decomposing the dried precursor, and a step of crystallizing the pyrolyzed precursor together with fine particles are required. However, in the method of irradiating laser light, these heat treatments can be performed simultaneously by irradiating the interface between the precursor solution and the first substrate with laser light.

  In addition, during the heat treatment by irradiating laser light, the sol-gel liquid flows around the irradiation spot of the scanned laser light. The fine particles mixed in the sol-gel liquid are crystallized while flowing together with the sol-gel liquid components, so that the fine particles having a small particle diameter easily enter the gaps between the fine particles having a large particle diameter. Therefore, it is preferable to employ a method of irradiating laser light because an electromechanical conversion film that is denser and has less cracking can be formed.

The laser light is not particularly limited, and examples thereof include laser light of gas laser such as YAG laser, CO ₂ laser, and excimer laser.

  The laser species, laser irradiation time, and laser output are appropriately selected by those skilled in the art according to the absorption wavelength band of the solvent contained in the precursor solution, the film thickness to be formed (the coating amount of the precursor solution), and the like. Can do. For example, when a continuous irradiation type (CW) laser is used, the irradiation time can be changed by changing the moving speed of scanning during irradiation. In the case of a pulsed laser, the irradiation time can be adjusted by changing the light emission time.

  In addition, it is preferable to pattern the first electrode layer only in the region where the pattern of the electromechanical conversion film is formed. Thereby, since the first electrode layer pattern becomes a target for laser light irradiation at the time of laser light irradiation, scanning of laser light irradiation becomes easy. In addition, by irradiating only the first electrode layer pattern with laser light, the tact time can be shortened, the production efficiency can be improved, and the production cost can be reduced.

(First embodiment)
Next, specific embodiments will be described with reference to the drawings.

[Preparation of fine particle mixed PZT precursor solution]
In the first embodiment, a PZT film is employed as the electromechanical conversion film, and a PZT precursor solution is prepared by the following method. As starting materials for the PZT precursor solution, lead acetate trihydrate, isopropoxide titanium and isopropoxide zirconium were used. The crystal water of lead acetate was dehydrated after being dissolved in methoxyethanol. In addition, the usage-amount of the starting material prepared so that lead amount might be 13 mol% excess with respect to a stoichiometric composition. As a result, it is possible to prevent a decrease in crystallinity due to lead loss during heat treatment by laser light irradiation.

  Isopropoxide titanium and isopropoxide zirconium were dissolved in methoxyethanol, alcohol exchange reaction and esterification reaction were advanced, and mixed with the methoxyethanol solution in which the lead acetate was dissolved to obtain a PZT precursor solution. . The solid content concentration of the PZT precursor solution was adjusted to 0.5 mol / liter. Moreover, acetylacetone was added as a stabilizer.

  The obtained PZT precursor solution was mixed with PZT fine particle powder having an average particle diameter of 400 nm (maximum particle diameter 700 nm, minimum particle diameter 5 nm). In this embodiment, in order to manufacture an electromechanical conversion film having a thickness of about 1 μm to 1.5 μm, the mixing ratio of the sol-gel liquid and the fine particles is set to 1: 2. More specifically, the concentration of the fine particle powder with respect to the sol-gel liquid deposition was adjusted to 0.86 g / ml. The mixing was performed by a ball mill method for 6 hours to disperse the fine particle powder in the precursor solution.

  As Comparative Example 1, a precursor solution in which PZT fine particle powder having an average particle size of 1 μm (maximum particle size of 10 μm, minimum particle size of 10 nm) was mixed was also prepared. In Comparative Example 1, a precursor solution was prepared in the same manner as in the first embodiment except that PZT fine particle powder having an average particle diameter of 1 μm was mixed.

  Furthermore, as Reference Example 1, a precursor solution in which PZT fine particle powder having a particle size of 400 nm (monodispersed and not having a substantial particle size distribution) was mixed was also prepared. In Reference Example 1, a precursor solution was prepared in the same manner as in the first embodiment except that PZT fine particle powder having a particle size of 400 nm was mixed.

[Application of fine particle mixed PZT precursor solution]
A Pt layer, an LNO layer, and a Pt layer were formed as a first electrode by sputtering on a substrate on which a protective film had been formed in advance. As described with reference to FIG. 3, the LNO layer was patterned by a photolithography process and an etching process, and a substrate having a region where the LNO layer was exposed and a region where the Pt layer remained was obtained.

  Next, the above-described SAM treatment was performed on the substrate. As described above, the SAM material has high reactivity with the Pt layer, but low reactivity with the LNO layer. Therefore, a SAM film was selectively formed only on the exposed Pt layer by the SAM treatment. Tetradecanethiol was used as the SAM-treated alkanethiol solution. The contact angle of the SAM film on the substrate after the SAM treatment with respect to pure water was 125 degrees, and the contact angle of the LNO layer was 10 degrees or less. In this embodiment, the patterning of the LNO film (that is, the hydrophilic region) is 50 μm in the horizontal direction in FIG. 1 and 1500 μm in the depth direction in FIG. A plurality of LNO films were patterned and formed at a pitch of 100 μm in the horizontal direction of FIG.

  The precursor solution mixed with the PZT fine particle powder described above was applied to the hydrophilic region on the substrate (the region where the LNO layer where the SAM film is not formed is exposed) on the substrate.

  FIG. 5 is a schematic diagram for explaining the landing state of the precursor solution in the first embodiment. FIG. 5A is a photograph of the substrate after applying the precursor solution mixed with the PZT fine particle powder of the first embodiment, and FIG. 5B is the PZT fine particle powder of Comparative Example 1. It is the photograph of the board | substrate after apply | coating the precursor solution with which was mixed.

  As shown in FIG. 5 (a), it can be seen that the precursor solution of the first embodiment is accurately landed on the hydrophilic region of the substrate, and a fine particle mixed precursor solution film having a desired pattern is obtained. On the other hand, as shown in FIG. 5 (b), in Comparative Example 1, sol-gel solution was not applied and landing of the precursor solution on the hydrophobic region was observed. This is presumably because the fine particles used in Comparative Example 1 had a large average particle diameter of 1 μm, so that the nozzles were clogged in the ink jet head, and the droplets of the fine particle mixed precursor solution were bent.

[Manufacture of electromechanical transducers]
The precursor solution film mixed with the fine particles was irradiated with a laser from the precursor solution film side of the substrate using a laser irradiation apparatus. Laser irradiation was performed on the interface between the surface of the LNO layer as the first electrode layer and the precursor solution film. By laser irradiation, the precursor solution film is heat-treated (crystallization process) to form an electromechanical conversion film. After the laser irradiation, the substrate was heated at 300 ° C. for several seconds to remove the SAM film formed on the Pt layer.

  As the laser irradiation apparatus, a YAG laser having an oscillation wavelength of 532 nm was used, the irradiation spot diameter of the laser light was 50 μm, the irradiation laser output was 100 mW, and the scanning speed was 500 μm / s. In the present embodiment, the scanning direction is the depth direction in FIG.

  The film thickness of the electromechanical conversion film obtained in the first embodiment and Reference Example 1 was 1.3 μm. The electromechanical conversion film obtained in the first embodiment had no cracks, but the electromechanical conversion film obtained in Reference Example 1 had some crack defects. In the electromechanical conversion film obtained in the first embodiment, since the used fine particles have a particle size distribution, the filling rate of the fine particle powder in the precursor solution film is large. On the other hand, since the fine particles used in the reference example do not have a particle size distribution, the filling rate is small. This difference in filling rate is considered to have influenced the occurrence rate of cracks.

  On the electromechanical conversion film obtained in the first embodiment and Reference Example 1, a Pt film was formed as an upper electrode to produce an electromechanical conversion element. The obtained electromechanical transducer was measured for electrical characteristics and electromechanical transduction ability (piezoelectric constant).

FIG. 6 shows an example of the PE hysteresis curve of the electromechanical transducer of the first embodiment. The electromechanical transducer of the first embodiment had a relative dielectric constant of 1450 and a dielectric loss of 0.04. Further, the remanent polarization of the electromechanical transducer of the first embodiment was 22 μC / cm ² and the coercive electric field was 35.6 kV / cm. On the other hand, the electromechanical transducer of Reference Example 1 had a relative dielectric constant of 950 and a dielectric loss of 0.13. For the electromechanical transducer obtained in the first embodiment, the amount of deformation by applying an electric field was measured with a laser Doppler vibrometer, and the piezoelectric constant d31 was calculated from matching by simulation. The piezoelectric constant d31 of the electromechanical transducer of the first embodiment was 125 pm / V. Accordingly, it was confirmed that the various characteristics of the electromechanical transducer obtained in the first embodiment and the reference example 1 have characteristics sufficient for use as a droplet discharge head.

(Second Embodiment)
In the second embodiment, an embodiment in which the electromechanical conversion element of the above-described embodiment is applied to a droplet discharge head will be described.

  The configuration of the droplet discharge head to which the electromechanical transducer of the above-described embodiment is applied has been described with reference to FIG.

  As the droplet discharge head of this embodiment, a configuration in which a plurality of droplet discharge heads of FIG. 1 are arranged can be used.

  The droplet discharge head according to this embodiment is manufactured by manufacturing the electromechanical conversion element described in the above embodiments, and then etching the nozzle plate 12 having the nozzle holes 11 to form the liquid chamber 21 from the back surface. It can be created by joining. Therefore, a droplet discharge head having the same performance as a conventional droplet discharge head can be manufactured with a simple manufacturing process.

  Further, in FIG. 1 and the present embodiment, the case of applying to an inkjet head has been described as an example of use as a droplet discharge head, but the present embodiment is not limited to this. For example, it can be applied to uses such as a micro pump, an ultrasonic motor, an acceleration sensor, a two-axis scanner for a projector, and an infusion pump.

(Third embodiment)
In the third embodiment, an example of an ink jet recording apparatus equipped with the droplet discharge head of the second embodiment will be described with reference to FIGS. FIG. 7 is a schematic view for explaining the ink jet recording apparatus of the present embodiment, and FIG. 8 is another schematic view for explaining the ink jet recording apparatus of the present embodiment.

  The ink jet recording apparatus according to the present embodiment includes a carriage 93 that is movable in the main scanning direction inside the recording apparatus main body 81, an ink jet recording head 94 that is an embodiment of the present invention mounted on the carriage 93, and an ink jet recording head. A printing mechanism unit 82 and the like configured by an ink cartridge 95 that supplies ink to 94 are accommodated. A sheet feeding cassette (or a sheet feeding tray) 84 on which a large number of sheets 83 can be stacked can be detachably mounted on the lower part of the recording apparatus main body 81. Further, the manual feed tray 85 for manually feeding the paper 83 can be turned over. The paper 83 fed from the paper feed cassette 84 or the manual feed tray 85 is taken in, and after a required image is recorded by the printing mechanism unit 82, the paper is discharged to a paper discharge tray 86 mounted on the rear side.

  The printing mechanism 82 holds the carriage 93 slidably in the main scanning direction with a main guide rod 91 and a sub guide rod 92 which are guide members horizontally mounted on left and right side plates (not shown). An inkjet recording head 94 according to the present invention for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) is provided on the carriage 93, and a plurality of ink ejection ports (nozzles). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward. Further, the carriage 93 is mounted with replaceable ink cartridges 95 for supplying ink of the respective colors to the ink jet recording head 94.

  The ink cartridge 95 has an air port (not shown) communicating with the air at the upper side, a supply port (not shown) for supplying ink to the inkjet recording head 94 at the lower side, and a porous body (not shown) filled with ink inside. doing. The ink supplied to the inkjet recording head 94 is maintained at a slight negative pressure by the capillary force of the porous body. In addition, although the heads of the respective colors are used here as the ink jet recording head 94, a single head having nozzles for ejecting ink droplets of the respective colors may be used.

  The carriage 93 is slidably fitted to the main guide rod 91 on the downstream side in the paper conveyance direction, and is slidably mounted on the sub guide rod 92 on the upstream side in the paper conveyance direction. In order to move and scan the carriage 93 in the main scanning direction, a timing belt 100 is stretched between a driving pulley 98 and a driven pulley 99 that are rotationally driven by the main scanning motor 97, so that the main scanning motor 97 is forward / reverse. The carriage 93 is reciprocated by the rotation. The timing belt 100 is fixed to the carriage 93.

  The ink jet recording apparatus according to the present embodiment also reverses the paper feed roller 101 that separates and feeds the paper 83 from the paper feed cassette 84, the friction pad 102, the guide member 103 that guides the paper 83, and the fed paper 83. A conveying roller 104 that conveys the sheet 83, a conveying roller 105 that is pressed against the peripheral surface of the conveying roller 104, and a leading end roller 106 that defines a feeding angle of the sheet 83 from the conveying roller 104 are provided. As a result, the paper 83 set in the paper feed cassette 84 is conveyed to the lower side of the inkjet recording head 94. The transport roller 104 is rotationally driven by a sub-scanning motor 107 through a gear train.

  The printing receiving member 108, which is a paper guide member, guides the paper 83 sent out from the conveyance roller 104 corresponding to the movement range of the carriage 93 in the main scanning direction on the lower side of the recording head 94. On the downstream side of the printing receiving member 108 in the paper conveyance direction, a conveyance roller 111 and a spur 112 that are rotationally driven to send out the paper 83 in the paper discharge direction are provided. Further, a discharge roller 113 and a spur 114 for sending the paper 83 to the discharge tray 86, and guide members 115 and 116 for forming a discharge path are provided.

  At the time of image recording, the recording head 94 is driven in accordance with the image signal while moving the carriage 93 to eject ink onto the stopped paper 83 to record one line, and after the paper 83 is conveyed by a predetermined amount Record the next line. Upon receiving a recording end signal or a signal that the trailing end of the paper 83 reaches the recording area, the recording operation is terminated and the paper 83 is discharged.

  A recovery device 117 for recovering defective ejection of the head 94 is provided at a position outside the recording area on the right end side in the movement direction of the carriage 93. The recovery device 117 includes a cap unit, a suction unit, and a cleaning unit. The carriage 93 is moved to the recovery device 117 side during printing standby, and the head 94 is capped by the capping unit, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained.

  When a discharge failure occurs, the discharge port of the head 94 is sealed by the capping unit, and bubbles and the like are sucked out from the discharge port by the suction unit through the tube. Also, ink or dust adhering to the ejection port surface is removed by the cleaning means, and the ejection failure is recovered. Further, the sucked ink is discharged into a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

  In the ink jet recording apparatus according to the present embodiment, since the droplet discharge head of the second embodiment is mounted, there is no ink droplet discharge failure due to vibration plate drive failure, and stable ink droplet discharge characteristics are obtained. , Improve the image quality.

DESCRIPTION OF SYMBOLS 10 Droplet discharge head 11 Nozzle hole 12 Nozzle plate 20 Liquid chamber board | substrate 21 Liquid chamber 30 Diaphragm 40 Electromechanical conversion element 41 Adhesion layer 42 1st electrode 43 Electromechanical conversion film 44 2nd electrode

Japanese Patent No. 3477724 JP 2006-1000033 A

Claims (8)

An electromechanical conversion film manufacturing method for manufacturing an electromechanical conversion film on at least a part of a substrate,
Modifying the surface of the base into a predetermined pattern;
A sol-gel solution containing fine particles having the same composition as the electromechanical conversion film and an average particle diameter of less than 1 μm, and a precursor of the electromechanical conversion film in a region where the surface is not surface-modified, A step of applying the ink jet method;
Heating the applied sol-gel solution;
A process for producing an electromechanical conversion film. The fine particles have a particle size distribution within a range from 5 nm to 1000 nm;
The method for producing an electromechanical conversion film according to claim 1. The step of heating is a step of irradiating the applied sol-gel solution with laser light.
The manufacturing method of the electromechanical conversion film of Claim 1 or 2. The step of irradiating the laser beam is a step of irradiating a laser to the interface between the applied sol-gel solution and the base,
The manufacturing method of the electromechanical conversion film of Claim 3. An electromechanical conversion film formed on the ground,
Modifying the surface of the base into a predetermined pattern;
A sol-gel solution containing fine particles having the same composition as the electromechanical conversion film and an average particle diameter of less than 1 μm, and a precursor of the electromechanical conversion film in a region where the surface is not surface-modified, A step of applying the ink jet method;
Heating the applied sol-gel solution;
An electromechanical conversion film formed by a process including:   The electromechanical conversion element including the electromechanical conversion film according to claim 5 and the second electrode on the electromechanical conversion film, wherein the base is a first electrode.   A liquid droplet ejection head comprising the electromechanical transducer according to claim 6.   An image forming apparatus comprising the droplet discharge head according to claim 7.