JP5696408B2 - Method for manufacturing electromechanical transducer - Google Patents

Description

The present invention relates to the production how the electro-mechanical conversion element.

  2. Related Art An ink jet recording apparatus and a liquid ejection head used as an image recording apparatus or an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, etc. Pressure chambers, pressure chambers, discharge chambers, liquid chambers, etc.) and electromechanical transducers such as piezoelectric elements that pressurize the ink in the pressurized chambers, or electrothermal transducers such as heaters, or ink flow paths. Comprising a diaphragm that forms a wall surface of the ink and an energy generating means comprising an electrode facing the wall, and ejecting ink droplets from the nozzles by pressurizing ink in the pressurizing chamber with the energy generated by the energy generating means It has been known.

  Two types of ink jet recording heads have been put into practical use: those using a longitudinal vibration mode piezoelectric actuator that extends and contracts in the axial direction of the piezoelectric element, and those using a flexural vibration mode piezoelectric actuator. As an actuator using a flexural vibration mode actuator, for example, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique, and this piezoelectric material layer is applied to a pressure generating chamber by a lithography method. A device in which a piezoelectric element is formed so as to be separated into shapes and independent of each pressure generating chamber is known.

  However, in the lithography method, there is a problem in that the use efficiency of the material is poor and the process becomes complicated, so that the cost is increased and the tact time is increased. In particular, since a piezoelectric thin film requires a thickness of several μm, formation of a fine pattern by a printing method is being studied for cost reduction. For example, a technique for forming a fine pattern using a printing technique such as ink jet on a patterned substrate whose base is water-repellent and hydrophilic has been introduced (for example, see Patent Documents 1 and 2).

  However, in this case, most of the embodiments use a metal electrode based mainly on Pt as the lower electrode, and there is a concern about the fatigue characteristics of PZT, which is a typical material for the piezoelectric material layer. Specifically, there is a concern about deterioration of fatigue characteristics due to Pb diffusion contained in PZT. With respect to this problem, it is disclosed that the fatigue characteristics of PZT are improved by using an oxide electrode (see, for example, Patent Document 3).

  However, when an oxide electrode is used, the specific resistance value is about 10 to 1000 times higher than when a metal electrode is used. For this reason, when an oxide electrode is provided in common for a plurality of piezoelectric elements, a voltage drop occurs when a large number of ink droplets are ejected at the same time by driving a large number of piezoelectric elements at the same time. The displacement amount becomes unstable, and there is a problem that stable ink ejection characteristics cannot be obtained.

The present invention has been made in view of the above, and an object thereof is to provide a stable manufacturing how the ink ejection characteristics can be obtained an electromechanical conversion element.

  The method of manufacturing the electromechanical transducer includes a first step of forming a first electrode made of metal, a second electrode made of a conductive oxide on the first electrode, and the second electrode A second step of patterning the electrode, a third step of surface-modifying only the first electrode to make it water-repellent, and forming an electromechanical conversion film on the patterned second electrode by an ink jet method It is a requirement to have a fourth step and a fifth step of forming a third electrode made of a conductive oxide on the electromechanical conversion film.

According to the present invention can provide a manufacturing how stable ink ejection characteristics can be obtained electromechanical conversion element.

It is sectional drawing which illustrates the electromechanical conversion element which concerns on this Embodiment. It is a top view (the 1) which illustrates the manufacturing method of the electromechanical conversion element which concerns on this Embodiment. It is a top view (the 2) which illustrates the manufacturing method of the electromechanical conversion element which concerns on this Embodiment. It is sectional drawing which shows the other example of the electromechanical conversion element which concerns on this Embodiment. It is a top view which shows the other example of the electromechanical conversion element which concerns on this Embodiment. It is sectional drawing which illustrates the droplet discharge head using the electromechanical conversion element which concerns on this Embodiment. FIG. 5 is a cross-sectional view showing an example in which a plurality of droplet discharge heads of FIG. 4 are arranged. It is sectional drawing (the 1) illustrated about the detailed process by the inkjet method which concerns on this Embodiment. It is sectional drawing (the 2) illustrated about the detailed process by the inkjet method which concerns on this Embodiment. It is a perspective view which illustrates an inkjet coating device. FIG. 5 is a characteristic diagram showing a representative electric field strength and a hysteresis curve of polarization. It is a perspective view which illustrates an inkjet recording device. It is a side view which illustrates an inkjet recording device.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

  FIG. 1 is a cross-sectional view illustrating an electromechanical transducer according to this embodiment. Referring to FIG. 1, the electromechanical conversion element 10 includes a first electrode 13, a second electrode 14, an electromechanical conversion film 15, and a third electrode 16. The electromechanical transducer 10 is formed on a substrate 11 with a diaphragm 12 interposed. In the electromechanical transducer 10, the first electrode 13 is a metal electrode, and the second electrode 14 and the third electrode 16 are oxide electrodes. Reference numeral 17 denotes a SAM (Self Assembled Monolayer) film made of an alkanethiol material or the like attached to the surface of the first electrode 13 (hereinafter referred to as SAM film 17).

  2A and 2B are plan views illustrating the method for manufacturing the electromechanical transducer according to this embodiment. With reference to FIG. 2A and 2B, the manufacturing method of the electromechanical transducer 10 is demonstrated easily.

  First, the diaphragm 12, the first electrode 13, and the second electrode 14 are laminated on the substrate 11 in this order, and the second electrode 14 is processed into a desired pattern in advance. Next, as shown in FIG. 2A, immersion treatment is performed using a SAM material such as an alkanethiol material. Thereby, since the SAM material such as a thiol material reacts and the SAM film 17 adheres to the surface of the first electrode 13 made of metal, the surface state can be made water repellent. In addition, since the SAM material such as a thiol material does not react with the surface of the second electrode 14 made of oxide, the SAM film 17 does not adhere and the surface state is made hydrophilic. As described above, by processing the second electrode 14 into a desired pattern in advance before the electromechanical conversion film 15 is fabricated, partial modification of the hydrophilic portion and the hydrophobic portion can be performed only by immersing the SAM material such as the alkanethiol material. Can be performed by self-alignment. Therefore, the tact time for producing the electromechanical conversion film 15 can be greatly shortened.

  Next, as illustrated in FIG. 2B, the electromechanical conversion film 15 and the third electrode 16 are stacked in this order on the second electrode 14. Here, in order to make the electromechanical conversion film 15 have a thickness of about several μm, it is necessary to produce a plurality of layers by, for example, an inkjet method. When PZT is used as the material of the electromechanical conversion film 15, the heat treatment temperature needs to be 400 ° C. or higher, and therefore the SAM film 17 made of an alkanethiol material or the like disappears after the heat treatment. Therefore, it is necessary to form a first layer of PZT on the second electrode 14, and after the heat treatment, before forming the second and subsequent layers of PZT, it is necessary to perform an immersion treatment on the base as in FIG. 2A.

  Specifically, as will be described in detail with reference to FIGS. 6A and 6B described later, even when the second and subsequent layers are laminated after heat treatment, the hydrophilic portion and the hydrophobic portion can be obtained only by immersing the SAM material such as an alkanethiol material. This partial modification can be performed by self-alignment.

  In addition, after immersion treatment is performed using an alkanethiol material and only the surface of the first electrode 13 made of metal is immersed, the immersion treatment is similarly performed using an organic silane material to form a second electrode made of an oxide. Only the surface of 14 or the surface of the electromechanical conversion film 15 may be surface-treated. Since the organosilane material does not react with the metal surface, only the surface of the second electrode 14 that is an oxide can be treated. By using an organosilane material having a highly hydrophilic group, the contrast ratio between the hydrophilic portion and the hydrophobic portion on the surface can be further increased, and the electromechanical conversion film 15 is more effective in producing the ink-jet method. become.

  Thus, even when PZT is used as the material of the electromechanical conversion film 15, Pb diffusion can be prevented by using oxide electrodes for the second electrode 14 and the third electrode 16. Further, by providing a metal electrode having a sufficiently low specific resistance as the first electrode 13, a sufficient current can be supplied to the common electrode when voltage driving is performed, and a large number of piezoelectric elements are driven simultaneously. Even in this case, a sufficient amount of displacement can be obtained without variation between elements. As a result, the electromechanical conversion element 10 capable of obtaining stable ink ejection characteristics can be realized.

  FIG. 3A is a cross-sectional view showing another example of the electromechanical transducer according to the present embodiment. FIG. 3B is a plan view showing another example of the electromechanical transducer according to the present embodiment. 3A and 3B, the electromechanical transducer 20 includes a first electrode 13, a second electrode 14, an electromechanical transducer film 15, a third electrode 16, an insulating protective film 21, and the like. The fourth electrode 22 and the fifth electrode 23 are included. The electromechanical transducer 20 is formed on the substrate 11 via the diaphragm 12.

  The insulating protective film 21 is formed so as to cover the first electrode 13, the electromechanical conversion film 15, and the third electrode 16. The fourth electrode 22 is provided on the insulating protective film 21 and is electrically connected to the first electrode 13 through a contact hole 22 x that penetrates the insulating protective film 21. The fifth electrode 23 is provided on the insulating protective film 21 and is electrically connected to the third electrode 16 through a contact hole 23 x penetrating the insulating protective film 21. The second electrode 14, the third electrode 16, and the fifth electrode 23 are individual electrodes provided individually for each electromechanical conversion film 15, and the first electrode 13 and the fourth electrode 22. Is a common electrode provided in common for each electromechanical conversion film 15.

  By forming the insulating protective film 21 as shown in FIGS. 3A and 3B, it is possible to prevent problems due to electrical shorts and the like, and the breakdown of the electromechanical conversion film 15 due to moisture, gas, or the like.

  Next, a liquid droplet ejection head using the electromechanical transducer according to this embodiment will be described. FIG. 4 is a cross-sectional view illustrating a droplet discharge head using the electromechanical transducer according to this embodiment. Referring to FIG. 4, the droplet discharge head 30 includes an electromechanical transducer 10, a vibration plate 12, an adhesion layer 35, a pressure chamber substrate 37 that is a Si substrate, and a nozzle plate 39 provided with a nozzle 38. And have. The adhesion layer 35 is a layer provided to increase the adhesion between the first electrode 13 and the diaphragm 12. A pressure chamber 40 is formed by the vibration plate 12, the pressure chamber substrate 37, and the nozzle plate 39. In FIG. 4, the liquid supply means, the flow path, and the fluid resistance are omitted.

  FIG. 5 is a cross-sectional view showing an example in which a plurality of droplet discharge heads of FIG. 4 are arranged. The plurality of electromechanical transducers 10 can be formed on the Si substrate via the diaphragm 12 and the adhesion layer 35 so as to have performance equivalent to that of bulk ceramics in a simple manufacturing process. Thereafter, in order to form the pressure chamber 40, a part of the Si substrate is etched away from the back surface, and the nozzle plate 39 having the nozzles 38 is joined, whereby the droplet discharge head 50 can be manufactured. In FIG. 5, the liquid supply means, the flow path, and the fluid resistance are omitted.

  Next, each component shown in FIG. 1, FIG. 2A, FIG. 2B, FIG. 3A, FIG.

[Substrate 11]
As the substrate 11, it is preferable to use a silicon single crystal substrate, and it is usually preferable to have a thickness of 100 to 600 μm. There are three types of plane orientations, (100), (110), and (111). Generally, (100) and (111) are widely used in the semiconductor industry. In addition, a silicon single crystal substrate having a (100) plane orientation was used. Further, when the pressure chamber 40 as shown in FIG. 4 is manufactured, the silicon single crystal substrate is processed by using etching. In this case, anisotropic etching can be used as an etching method.

Anisotropic etching utilizes the property that the etching rate differs with respect to the plane orientation of the crystal structure. For example, in anisotropic etching immersed in an alkaline solution such as KOH, the (111) plane has an etching rate of about 1/400 compared to the (100) plane. Therefore, a structure having an inclination of about 54 ° can be produced in the plane orientation (100), whereas a deep groove can be dug in the plane orientation (110), so that the arrangement density is increased while maintaining rigidity. can do. In this embodiment, it is also possible to use a silicon single crystal substrate having a (110) plane orientation. However, in this case, it should be noted that SiO ₂ which is a mask material is also etched.

[Vibration plate 12]
In the droplet discharge head 30 shown in FIG. 4, the diaphragm 12 as a base is deformed and displaced by the force generated by the electromechanical conversion film 15, and the ink droplets in the pressure chamber 40 are discharged. Therefore, it is preferable that the diaphragm 12 has a predetermined strength. As the diaphragm 12, a material made of a material such as Si, SiO ₂ , Si ₃ N ₄ or the like by the CVD method can be used. Furthermore, it is preferable to select a material close to the linear expansion coefficient of the first electrode 13 and the electromechanical conversion film 15 as the material of the diaphragm 12.

In particular, since PZT is often used as the material of the electromechanical conversion film 15, the material of the diaphragm 12 has a linear expansion coefficient close to 8 × 10 ⁻⁶ (1 / K) of PZT. A material having a linear expansion coefficient of 5 × 10 ⁻⁶ to 10 × 10 ⁻⁶ (1 / K) is preferable, and further, a linear expansion coefficient of 7 × 10 ^{−6 to} 9 × 10 ⁻⁶ (1 / K) is preferable. More preferred is a material having

  Specific examples of the material of the diaphragm 12 include aluminum oxide, zirconium oxide, iridium oxide, ruthenium oxide, tantalum oxide, hafnium oxide, osmium oxide, rhenium oxide, rhodium oxide, palladium oxide, and compounds thereof. These can be produced by a spin coater using a sputtering method or a sol-gel method (Sol-gel) method.

  The film thickness of the diaphragm 12 is preferably 0.1 to 10 μm, and more preferably 0.5 to 3 μm. If it is smaller than this range, it becomes difficult to process the pressure chamber 40 as shown in FIG. 4, and if it is larger than this range, the vibration plate 12 is difficult to be deformed and displaced, and ink droplet ejection becomes unstable.

[First electrode 13]
As the metal material used for the first electrode 13, for example, platinum having high heat resistance and low reactivity can be used. However, platinum may not have sufficient barrier properties against lead, and it is preferable to use a platinum group element such as iridium or platinum-rhodium, or an alloy film thereof. Further, platinum has poor adhesion to the diaphragm 12 (particularly SiO ₂ ) as a base. Therefore, when platinum is used as the material of the first electrode 13, it is preferable that the adhesion layer 35 is first laminated as a lower layer of the first electrode 13 as shown in FIG. 4. As a material of the adhesion layer 35, for example, Ti, TiO ₂ , Ta, Ta ₂ O ₅ , Ta ₃ N ₅ or the like can be used. As a manufacturing method of the first electrode 13, a sputtering method, vacuum deposition, or the like can be used. As a film thickness of the 1st electrode 13, 0.05-1 micrometer is preferable and 0.1-0.5 micrometer is more preferable.

[Second electrode 14]
When a complex oxide containing lead is used as the electromechanical conversion film 15, reaction or diffusion of lead contained in the electromechanical conversion film 15 with the second electrode 14 may occur to deteriorate the piezoelectric characteristics. Therefore, an electrode material having a barrier property against reaction / diffusion with lead is required as the material of the second electrode 14.

As a material of the second electrode 14, it is effective to use a conductive oxide. A specific material of the second electrode 14 is SrRuO ₃ , which is described by the chemical formula ABO ₃ and is a composite oxide mainly composed of A = Sr, Ba, Ca, La, B = Ru, CO, Ni. and CaRuO _3, another is a solid solution thereof _{(Sr1-x Cax) O 3} , LaNiO 3 or SrCOO _3, which is a solid solution thereof (La, Sr) may be _{(Ni1-y COy) O 3} (y = 1 ). Other oxide materials include IrO ₂ and RuO ₂ . In other words, the material of the second electrode 14 is described by the chemical formula ABO ₃ , where A is one or more of Sr, Ba, Ca, and La, and B is one or more of Ru, Co, and Ni. It can be a composite oxide as a component, or an oxide made of any of IrO ₂ and RuO ₂ .

  As a method for producing the second electrode 14, it can be produced by a spin coater using a sputtering method or a sol-gel method. In that case, since patterning is required, a desired pattern is obtained by photolithography etching or the like. As a method other than this, the second electrode 14 which is a hydrophilic region where the surface of the first electrode 13 which is the base other than the region where the second electrode 14 is formed is surface-modified to make it water-repellent and not water-repellent. The second electrode 14 may be formed in the formation region using an inkjet method. Note that the formation region of the second electrode 14 is a region where the patterned second electrode 14 is formed.

  Here, with reference to FIGS. 6A and 6B, a detailed process by the ink jet method according to the present embodiment will be described.

  First, as shown in FIG. 6A (a), a first electrode 13 as a base is prepared. Then, as shown in FIG. 6A (b), a SAM film 17 (self-assembled monomolecular film) is applied over the entire surface of the first electrode 13. Although the SAM film 17 differs depending on the material of the base, thiol is mainly selected when a metal is used as the base. Although the reactivity and hydrophobicity (water repellency) vary depending on the molecular chain length, C6 to C18 molecules are dissolved in a general organic solvent (alcohol, acetone, toluene, etc.) (concentration: several moles / liter). Using this solution, the entire surface can be applied by immersion, steam, spin coater, or the like, and the excess molecules can be formed on the surface of the first electrode 13 by being washed with substitution solvent and drying.

  Next, as shown in FIG. 6A (c), a photoresist 81 is patterned by photolithography. Next, as shown in FIG. 6A (d), the portion of the SAM film 17 not covered with the photoresist 81 is removed by dry etching, and the photoresist 81 is further removed to complete the patterning of the SAM film 17. To do.

  Next, as shown in FIG. 6A (e), when a droplet is applied by the droplet discharge head 82, a coating film is not formed on the SAM film 17 which is a hydrophobic portion, and the hydrophilic surface from which the SAM film 17 has been removed. The patterned precursor coating film 14a is formed only on the part. Thereafter, heat treatment is performed according to a normal sol-gel process. The heat treatment temperature of the patterned precursor coating film 14a is set such that the organic combustion temperature is 300 to 500 ° C, the crystallization temperature is 500 to 700 ° C, and the like. By such a high temperature treatment, as shown in FIG. 6A (f), the SAM film 17 disappears, and the patterned precursor coating film 14b in which the patterned precursor coating film 14a is heat-treated is produced.

  When the ink jet method is used, the film thickness is about 30 to 100 nm per layer, so that several layers need to be overprinted. Therefore, as shown in FIG. 6B (a), the SAM film 17 is patterned again to form the SAM film 17 around the patterned precursor coating film 14b. Then, as shown in FIG. 6B (b), a droplet is applied by a droplet discharge head 82, and a patterned precursor coating film 14b is formed on the patterned precursor coating film 14b which is a hydrophilic portion from which the SAM film 17 is removed. 14c is formed. Thereafter, heat treatment is performed as in FIG. 6A (e). By repeating the steps of FIG. 6B (a) and FIG. 6B (b), the patterned precursor coating film has a desired thickness as shown in FIG. 6B (c), and the second electrode 14 is obtained. As a film thickness of the 2nd electrode 14, 0.05-1 micrometer is preferable and 0.1-0.5 micrometer is more preferable. Thus, the 2nd electrode 14 patterned by the inkjet method is obtained.

  6A and 6B show an example in which the second electrode 14 is formed on the first electrode 13 serving as a base by an ink-jet method. However, for example, an ink-jet method may be used on the second electrode 14 serving as a base. When the electromechanical conversion film 15 is formed by the above, or when the third electrode 16 is formed by an inkjet method on the electromechanical conversion film 15 serving as a base, the same process can be performed.

[Electromechanical conversion film 15]
In the present embodiment, PZT is mainly used as the material of the electromechanical conversion film 15. PZT is a solid solution of lead zirconate (PbTiO ₃ ) and titanic acid (PbTiO ₃ ), and the characteristics differ depending on the ratio. The composition exhibiting excellent piezoelectric properties has a ratio of PbZrO ₃ and PbTiO ₃ of 53:47. When expressed by the chemical formula, it is indicated as Pb (Zr0.53, Ti0.47) O ₃ , generally PZT (53/47). It is. 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, Znmg, and Nb as main components. As specific description (Pb1-x, Ba) ( Zr, Ti) O 3, substituted by (Pb1-x, Sr) ( Zr, Ti) O 3, which is a part of Pb of the A site Ba and Sr This is the case. 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.

  The electromechanical conversion film 15 can be produced by a spin coater using a sputtering method or a sol-gel method. In that case, since patterning is required, a desired pattern is obtained by photolithography etching or the like. When PZT is prepared by a sol-gel method, a PZT precursor solution can be prepared by using lead acetate, zirconium alkoxide, and titanium alkoxide compound as starting materials and dissolving in methoxyethanol as a common solvent to obtain a uniform solution. Since the metal alkoxide compound is easily hydrolyzed by moisture in the atmosphere, an appropriate amount of a stabilizer such as acetylacetone, acetic acid or diethanolamine may be added to the precursor solution as a stabilizer.

  When a PZT film is obtained on the entire surface of the base substrate, it is obtained by forming a coating film by a solution coating method such as spin coating and performing heat treatments such as solvent drying, thermal decomposition, and crystallization. Since transformation from the coating film to the crystallized film involves volume shrinkage, it is necessary to adjust the precursor concentration so that a film thickness of 100 nm or less can be obtained in one step in order to obtain a crack-free film.

  In the case of manufacturing by an inkjet method, a film patterned by a manufacturing flow similar to that of the second electrode 14 (see FIGS. 6A and 6B) can be obtained. As for the surface modifying material, although it varies depending on the material of the base, the silane compound is mainly selected when the oxide is used as the base, and the alkanethiol is mainly selected when the metal is the base.

  The thickness of the electromechanical conversion film 15 is preferably 0.5 to 5 μm, more preferably 1 μm to 2 μm. If it is smaller than this range, it will not be possible to generate a sufficient displacement, and if it is larger than this range, many layers will be laminated, resulting in an increase in the number of steps and a longer process time.

[Third electrode 16]
As the material of the third electrode 16, it is effective to use a conductive oxide as an electrode, as in the second electrode 14. A specific material of the third electrode 16 is SrRuO ₃ , which is described by the chemical formula ABO ₃ , and is a composite oxide mainly composed of A = Sr, Ba, Ca, La, B = Ru, CO, Ni. and CaRuO _3, another is a solid solution thereof _{(Sr1-x Cax) O 3} , LaNiO 3 or SrCOO _3, which is a solid solution thereof (La, Sr) may be _{(Ni1-y COy) O 3} (y = 1 ). Other oxide materials include IrO ₂ and RuO ₂ . It is also effective to use a platinum group element such as platinum, iridium, or platinum-rhodium, an alloy film thereof, an Ag alloy, Cu, Al, or Au on the conductive oxide to supplement the wiring resistance.

  The third electrode 16 can be manufactured by a spin coater using a sputtering method or a sol-gel method. In that case, since patterning is required, a desired pattern is obtained by photolithography etching or the like. In addition, a film patterned by an inkjet method can be manufactured using a step of partially modifying the surface of the second electrode 14 and the base surface. In the case of manufacturing by the inkjet method, a patterned film can be obtained by a manufacturing flow similar to that of the second electrode 14 (see FIGS. 6A and 6B). As a film thickness of the 3rd electrode 16, 0.05-1 micrometer is preferable and 0.1-0.5 micrometer is more preferable.

[Insulating protective film 21]
The insulating protective film 21 is provided for the purpose of preventing defects due to electrical shorts and the like, and the destruction of the electromechanical conversion film 15 due to moisture, gas, or the like. As a material of the insulating protective film 21, an inorganic film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film, or an organic film such as a polyimide or a parylene film is preferable. As a film thickness of the insulating protective film 21, 0.5-20 micrometers is preferable and 1-10 micrometers is more preferable. If the thickness of the insulating protective film 21 is smaller than this range, the function as the insulating protective film cannot be sufficiently achieved, and if it is larger than this range, the process time becomes longer.

  As a method for manufacturing the insulating protective film 21, CVD, sputtering, spin coating, or the like can be used. In addition, it is necessary to prepare contact holes 22x and 23x for electrically connecting the fourth electrode 22 and the fifth electrode 23 with the first electrode 13 and the third electrode 16, respectively. To obtain a desired pattern.

In addition, the insulating protective film 21 having the contact holes 22x and 23x can be manufactured by a single process using a screen printing method. As the paste-like material used for screen printing, a resin and inorganic or organic particles dissolved in an organic solvent can be used. Examples of the resin include materials including polyvinyl alcohol resin, polyvinyl acetal resin, acrylic resin, ethyl cellulose resin, and the like. Examples of the inorganic particles include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), zinc oxide (ZnO), and barium titanate (BaTiO ₃ ). Among these, materials having a relatively low relative dielectric constant such as silica, alumina, and zinc oxide are preferable.

  In the case of forming a fine pattern as assumed in the present invention, insulation protection is achieved by transferring a paste-like material filled in a mesh having a wire diameter of 15 to 50 μm and an aperture ratio of 40 to 60%. Since the film 21 is formed, the insulating protective film 21 can be formed together with the contact holes 22x and 23x.

[Fourth electrode 22, fifth electrode 23]
The material of the fourth electrode 22 and the fifth electrode 23 is preferably a metal electrode material made of any one of an Ag alloy, Cu, Al, Au, and PTir. The fourth electrode 22 and the fifth electrode 23 can be formed by using, for example, a sputtering method, a spin coating method, or the like, and then can be formed into a desired pattern by photolithography etching or the like. In addition, a film patterned by an inkjet method can be manufactured by using a step of partially modifying the surface of the insulating protective film 21 that is a base. In the case of manufacturing by an inkjet method, a patterned film can be obtained by a manufacturing flow similar to that of the second electrode 14 (see FIGS. 6A and 6B).

  As the surface modifying material, a silane compound is mainly selected when the insulating protective film 21 as an underlayer is an oxide. In the case of an organic material such as polyimide (PI), the surface energy of the irradiated region can be increased by irradiating with ultraviolet rays. As a result, the high-definition patterns of the fourth electrode 22 and the fifth electrode 23 can be directly drawn in the region where the surface energy is increased by using the inkjet method. As a polymer material capable of increasing the surface energy with ultraviolet rays, for example, materials described in JP-A-2006-060079 can be used.

  Moreover, the electrode film used as the 4th electrode 22 and the 5th electrode 23 can be obtained by screen printing using the following paste-form materials marketed. Perfect Gold (registered trademark) (gold paste, trade name manufactured by Vacuum Metallurgical Co., Ltd.), Perfect Copper (copper paste, trade name manufactured by Vacuum Metallurgical Co., Ltd.), OrgacOnPastevariant 1/4, Paste variant 1/3 (above, transparent PEDOT / PSS ink, trade name manufactured by Agfa Gebalto, Japan), OrgacOnCarbOnPaste variant 2/2 (carbon electrode paste, trade name, manufactured by Agfa Gebalto, Japan), BAYTRON (registered trademark) P (PEDT / PSS aqueous solution, Stark Vitech, Japan) Product name).

  The thickness of each of the fourth electrode 22 and the fifth electrode 23 is preferably 0.1 to 20 μm, and more preferably 0.2 to 10 μm. If the film thickness of each of the fourth electrode 22 and the fifth electrode 23 is smaller than this range, the resistance becomes large and it becomes impossible to pass a sufficient current through the electrodes, so that the head ejection becomes unstable and larger than this range. And process time will be longer.

  Examples of the present invention will be described below.

<Example 1>
A thermal oxide film (film thickness of 1 micron) was formed on a silicon wafer, and a titanium film (film thickness of 50 nm) was formed as the adhesion layer 35, and subsequently a platinum film (film thickness of 200 nm) was formed as the first electrode 13 by sputtering. The adhesion layer 35 made of a titanium film has a role of improving the adhesion between the thermal oxide film and the platinum film. Next, a SrRuO film (thickness: 200 nm) was formed by sputtering as the second electrode. Thereafter, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) is formed by a spin coat method, a resist pattern 81 is formed by ordinary photolithography, and then an ICP etching apparatus (manufactured by Samco) is used as shown in FIGS. 1 and 2A. A simple pattern was produced.

Next, as the surface treatment of the first electrode 13, CH ₃ (CH ₂ ) ₆ —SH is used as the alkanethiol and immersed in a solution having a concentration of 0.01 mol / liter (solvent: isopropyl alcohol). The SAM treatment was performed after washing with alcohol and drying. The contact angle of water on the platinum film after SAM treatment is 92.2 °, whereas the contact angle of water on the SrRuO film is 15 °, and the subsequent electromechanical conversion film 15 is formed by inkjet. It was confirmed that there was sufficient contrast between the hydrophilic surface and the water repellent surface.

  Next, PZT (53/47) is formed as an electromechanical conversion film 15 by inkjet. In the synthesis of the precursor coating solution, lead acetate trihydrate, isopropoxide titanium, and isopropoxide zirconium were used as starting materials. Crystal water of lead acetate was dissolved in methoxyethanol and then dehydrated. The lead amount is 10 mol% excess relative to the stoichiometric composition. This is to prevent crystallinity deterioration due to so-called lead loss during heat treatment.

  Isopropoxide titanium and isopropoxide zirconium were dissolved in methoxyethanol, the alcohol exchange reaction and the esterification reaction were advanced, and the PZT precursor solution was synthesized by mixing with the methoxyethanol solution in which the lead acetate was dissolved. The PZT concentration was 0.1 mol / liter. A PZT precursor solution is applied to the hydrophilic region (SrRuO film produced as the second electrode 14) patterned in the step of FIGS. 6A and 6B by using this liquid with an ink jet coating apparatus.

  FIG. 7 is a perspective view illustrating an inkjet coating apparatus. In the inkjet coating apparatus 60 shown in FIG. 7, a Y-axis driving unit 62 is installed on a gantry 61, and a stage 64 on which a substrate 63 is mounted is installed on the platform 61 so as to be driven in the Y-axis direction. The stage 64 is attached with suction means such as vacuum and static electricity not shown, and the substrate 63 is fixed. The ink jet coating apparatus is a typical example of the droplet discharge apparatus according to the present invention.

  An X-axis driving means 66 is attached to the X-axis support member 65, and a head base 68 mounted on the Z-axis driving means 67 is attached to the X-axis support member 65, so that it can move in the X-axis direction. ing. An ink jet head 69 that discharges ink is mounted on the head base 68. Ink is supplied from an ink tank (not shown) to the inkjet head 69 via a colored resin ink supply pipe 70. The ink jet head 69 is a typical example of a droplet discharge head according to the present invention.

  The film thickness obtained by one film formation is preferably around 100 nm, and the precursor concentration is optimized from the relationship between the film formation area and the amount of applied precursor. FIG. 6A (e) described above shows a state where the coating is performed by the ink jet coating apparatus, and the precursor solution spreads only in the hydrophilic portion and forms a pattern due to the contrast of the contact angle. This is treated as 120 ° C. as the first heating (solvent drying), and then the organic substance is thermally decomposed (500 ° C.) as shown in FIG. 6A (f). The film thickness at this time was 90 nm.

  Subsequently, a patterned SAM film was formed by performing immersion treatment with alkanethiol as repeated surface treatment. The contact angle of water on the platinum film after SAM treatment is 92.2 °, whereas the contact angle of water on the PZT film prepared by inkjet is 15 °, and the second and subsequent layers are repeated. It was confirmed that the hydrophilic surface and the water-repellent surface had sufficient contrast for film formation by inkjet.

  The above process was repeated 6 times to obtain a 540 nm film, and then crystallization heat treatment (temperature 700 ° C.) was performed by RTA (rapid heat treatment). Defects such as cracks did not occur in the film. Further, crystallization treatment was performed by performing SAM film treatment 6 times → selective application of PZT precursor → drying at 120 ° C. → thermal decomposition at 500 ° C. Defects such as cracks did not occur in the film. The film thickness reached 1000 nm.

  Next, a SrRuO film (thickness: 200 nm) was formed by sputtering as the third electrode 16. Thereafter, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) is formed by spin coating, a resist pattern is formed by ordinary photolithography, and then an ICP etching apparatus (manufactured by Samco) is used as shown in FIGS. 1 and 2B. The pattern was formed and the electromechanical transducer 10 was produced.

  Next, as the insulating protective film 21, a parylene film (film thickness: 2 μm) was formed by CVD. Thereafter, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) is formed by spin coating, a resist pattern is formed by ordinary photolithography, and then a pattern as shown in FIGS. 3A and 3B is formed using RIE (manufactured by Samco). Produced.

  Finally, an Al film (film thickness 5 μm) was formed by sputtering as the fourth electrode 22 and the fifth electrode 23. Thereafter, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) is formed by spin coating, a resist pattern is formed by ordinary photolithography, and then a pattern as shown in FIGS. 3A and 3B is formed using RIE (manufactured by Samco). The electromechanical transducer 20 was formed.

<Example 2>
The first electrode 13 is formed in the same process as in Example 1, and then the surface treatment of the first electrode 13 is performed using CH ₃ (CH ₂ ) ₆ —SH as the alkane thiol with a concentration of 0. It was immersed in a 01 mol / liter (solvent: isopropyl alcohol) solution, then washed and dried with isopropyl alcohol, and a SAM treatment was performed. A photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) was formed by spin coating, a resist pattern was formed by ordinary photolithography, and oxygen plasma treatment was performed to remove the exposed SAM film. The residual resist after the treatment was dissolved and removed with acetone, and the contact angle was evaluated. As a result, the removal portion showed a value of 46.2 °, and that of the portion covered with the resist showed a value of 104.3 °. It was confirmed that the pattern was made.

  Next, a LaNiO film was formed as the second electrode 14 by inkjet. In the synthesis of the precursor coating solution, isopropoxide lanthanum and bis (acetylacetonato) nickel (II) (dihydrate) were used as starting materials. After dehydration treatment of bis (acetylacetonato) nickel (II) (dihydrate), isopropoxide lanthanum and bis (acetylacetonato) nickel (II) are dissolved in methoxyethanol, alcohol exchange reaction, The esterification reaction was advanced to synthesize a LaNiO precursor solution to a concentration of 0.3 mol / liter.

  This liquid is applied to the hydrophilic region using the ink jet coating apparatus 60 as in the first embodiment. Due to the contact angle contrast, the precursor solution spreads only in the hydrophilic part and forms a pattern. This was treated at 150 ° C. as the first heating (solvent drying), heat-treated at 400 ° C. for 1 hour at a rate of temperature rise (10 ° C./min) in an oxygen atmosphere, and finally crystallization heat treatment (temperature 700 ° C.) Was performed by RTA (rapid heat treatment). At this time, the film thickness was 80 nm. Subsequently, after repeated washing with isopropyl alcohol, a SAM film was formed by the same dipping treatment. The above process was repeated three times to obtain a 240 nm film. Defects such as cracks did not occur in the film.

  Next, the substrate was subjected to SAM treatment by the same production method as in Example 1, and then the electromechanical conversion film 15 was produced by the inkjet method. Next, after performing the SAM process of the foundation | substrate by the method similar to the 2nd electrode 14, LaNiO was formed as the 3rd electrode 16 with the inkjet method, and the electromechanical conversion element 10 was produced.

Next, as the insulating protective film 21, SiO ₂ (film thickness 2 μm) was formed by CVD. Thereafter, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) is formed by spin coating, a resist pattern is formed by ordinary photolithography, and then a pattern as shown in FIGS. 3A and 3B is formed using RIE (manufactured by Samco). Produced.

  Next, after performing the SAM treatment of the base, using a commercially available AgPd ink, printing on a desired pattern with the inkjet coating apparatus 60, and then heat-treating at 300 ° C. to form the fourth electrode 22 and the fifth electrode 23. An electromechanical transducer 20 was produced.

<Example 3>
Until the pattern formation after the formation of the second electrode 14, after performing the same process as in Example 1, as the surface treatment of the first electrode 13, CH ₃ (CH ₂ ) ₆ —SH is used as the alkanethiol, It was immersed in a 0.01 mol / liter (solvent: isopropyl alcohol) solution, then washed and dried with isopropyl alcohol, and SAM treatment was performed. After that, as a surface treatment of the second electrode 14, using a silane compound (Chemical Formula 1), it is immersed in a 0.01 mol / liter (solvent: isopropyl alcohol) solution, then washed and dried with isopropyl alcohol, SAM treatment was performed.

ＳＡＭ処理後の白金膜上の水の接触角は９２．２°であるのに対して、ＳｒＲｕＯ膜上
の水の接触角は５°以下であり、その後の電気機械変換膜１５をインクジェットにより成
膜するには、親水面と撥水面のコントラストが十分取れていることが確認できた。

The contact angle of water on the platinum film after SAM treatment is 92.2 °, whereas the contact angle of water on the SrRuO film is 5 ° or less, and the subsequent electromechanical conversion film 15 is formed by inkjet. It was confirmed that the hydrophilic surface and the water-repellent surface had sufficient contrast for film formation.

  Next, the electromechanical conversion film 15 was produced by the inkjet method by the same production method as in Example 1. At this time, in the production of the electromechanical conversion film for the second and subsequent layers, the SAM treatment of the base is performed using alkanethiol as the surface treatment of the first electrode 13 and the silane compound as the surface treatment of the electromechanical conversion film, and then inkjet It was produced by the method. The insulating protective film 21, the fourth electrode 22, and the fifth electrode 23 were produced in the same manner as in Example 1 to produce the electromechanical conversion element 20.

<Comparative example 1>
The first electrode 13 is formed in the same process as in Example 1, and then the surface treatment of the first electrode 13 is performed using CH ₃ (CH ₂ ) ₆ —SH as the alkane thiol with a concentration of 0. It was immersed in a 01 mol / liter (solvent: isopropyl alcohol) solution, then washed and dried with isopropyl alcohol, and a SAM treatment was performed. A photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) was formed by spin coating, a resist pattern was formed by ordinary photolithography, and oxygen plasma treatment was performed to remove the exposed SAM film. The residual resist after the treatment was dissolved and removed with acetone, and the contact angle was evaluated. As a result, the removal portion showed a value of 46.2 °, and that of the portion covered with the resist showed a value of 104.3 °. It was confirmed that the pattern was made.

  Next, the base SAM treatment was performed by the same manufacturing method as in Example 1, and then the electromechanical conversion film 15 was manufactured by inkjet. Next, a Pt film (thickness 200 nm) was formed by sputtering as an electrode. Thereafter, a photoresist (TSMR8800) manufactured by Tokyo Ohka Co., Ltd. is formed by spin coating, a resist pattern is formed by ordinary photolithography, and then an ICP etching apparatus (manufactured by Samco) is used as shown in FIGS. 3A and 3B. A pattern was produced, and the insulating protective film 21, the fourth electrode 22, and the fifth electrode 23 were produced in the same manner as in Example 1 to produce the electromechanical conversion element 20.

<Comparative example 2>
Until the formation of the second electrode 14, the same process as in Example 1 was performed, and then the surface treatment of the second electrode 14 was performed using CH ₃ (CH ₂ ) ₇ —SiCl ₃ as the silane compound, with a concentration of 0. It was immersed in a 0.01 mol / liter (solvent: isopropyl alcohol) solution, then washed and dried with isopropyl alcohol, and subjected to SAM treatment. A photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) was formed by spin coating, a resist pattern was formed by ordinary photolithography, and oxygen plasma treatment was performed to remove the exposed SAM film. The residual resist after the treatment was dissolved and removed with acetone, and the contact angle was evaluated. As a result, the removal portion showed a value of 46.2 °, and that of the portion covered with the resist showed a value of 104.3 °. It was confirmed that the pattern was made.

  Next, the electromechanical conversion film 15 was produced by an inkjet method. At this time, since the silane compound disappears after baking at 500 ° C. in the production of the first layer, the SAM film is patterned by performing the same SAM treatment before producing the electromechanical conversion film of the second layer, and then inkjet Thus, an electromechanical conversion film 15 was produced. About the 3rd electrode 16, the insulating protective film 21, the 4th electrode 22, and the 5th electrode 23, it produced similarly to Example 1, and the electromechanical transducer 20 was produced.

<Evaluation of Examples 1 to 3 and Comparative Examples 1 and 2>
Electrical characteristics and electromechanical conversion ability (piezoelectric constant) were evaluated using the electromechanical transducers prepared in Examples 1 to 3 and Comparative Examples 1 and 2, and the results are summarized in Table 1.

表１に示すように、初期においては、実施例１〜３並びに比較例１及び２の何れにおいても、膜の比誘電率εｒは１２００前後、誘電損失ｔａｎδは０．０２前後、残留分極Ｐｒは２０〜２５μＣ／ｃｍ^２程度、抗電界Ｅｃは４０〜５０ｋＶ／ｃｍ程度であり、通常のセラミック焼結体と同等の特性であった。なお、図８は、代表的な電界強度と分極のヒステリシス曲線を示す特性図である。

As shown in Table 1, initially, in any of Examples 1 to 3 and Comparative Examples 1 and 2, the relative dielectric constant εr of the film is around 1200, the dielectric loss tan δ is around 0.02, and the residual polarization Pr is The coercive electric field Ec was about ²⁰ to 25 kC / cm ^{2 and} about 40 to 50 kV / cm, which were the same characteristics as a normal ceramic sintered body. FIG. 8 is a characteristic diagram showing a typical electric field strength and polarization hysteresis curve.

The electromechanical conversion capacity was calculated from the amount of deformation caused by the application of an electric field with a laser Doppler vibrometer and fitting by simulation. As shown in Table 1, the piezoelectric constant d31 was −140 to −160 pm / V in any of Examples 1 to 3 and Comparative Examples 1 and 2, which was also the same value as the ceramic sintered body. . This is a characteristic value that can be sufficiently designed as a liquid discharge head. There is no significant difference in the initial characteristics, but when looking at durability (characteristics immediately after applying 10 ¹⁰ times the applied voltage), the characteristics of Comparative Examples 1 and 2 are particularly large in the piezoelectric constant d31. I understood.

[Discharge evaluation of liquid discharge head]
Next, using the electromechanical transducers produced in Examples 1 to 3 and Comparative Examples 1 and 2, the liquid ejection head 50 of FIG. 5 was produced, and liquid ejection was evaluated. Using an ink whose viscosity was adjusted to 5 cp, and confirming the discharge situation when an applied voltage of −10 to −30 V was applied with a simple PuSH waveform, it was possible to discharge from any nozzle hole except for Comparative Example 2. It was confirmed.

  As for Comparative Example 2, the discharge varied and was not stable depending on the nozzle location. In the electromechanical conversion film manufacturing process, when the patterned SAM film was repeatedly manufactured, there was a portion where the adjacent electromechanical conversion films were in contact with each other because the alignment repeatability was insufficient. On the other hand, in Examples 1 to 3 and Comparative Example 1, the portions where the electromechanical conversion films were in contact with each other as in Comparative Example 2 were not seen.

As described above, it was confirmed that Examples 1 to 3 had a large difference in durability (characteristics immediately after applying 10 ¹⁰ times repeated applied voltage) as compared with Comparative Examples 1 and 2. That is, it was confirmed that the electromechanical transducers manufactured in Examples 1 to 3 can obtain stable ink droplet ejection characteristics including durability. In addition, it is thought that the reason that a favorable result was not obtained in Comparative Example 1 was that the second electrode layer 14 made of metal was not formed on the first electrode 13 made of conductive oxide. In addition, it is considered that the reason why a favorable result was not obtained in Comparative Example 2 was that the region where the electromechanical conversion film 15 was formed was not hydrophilized.

  Next, an example of an ink jet recording apparatus equipped with a droplet discharge head having an electromechanical conversion element manufactured by any one of Examples 1 to 3 will be described with reference to FIGS. FIG. 9 is a perspective view illustrating an ink jet recording apparatus, and FIG. 10 is a side view illustrating the ink jet recording apparatus. The ink jet recording apparatus is a typical example of the droplet discharge apparatus according to the present invention.

  Referring to FIGS. 9 and 10, the ink jet recording apparatus 100 mainly includes a carriage 101 that can move in the main scanning direction inside the recording apparatus main body, a recording head 102 mounted on the carriage 101, and the recording head 102. A printing mechanism 104 including an ink cartridge 103 for supplying ink; The recording head 102 is a droplet discharge head (inkjet head) having an electromechanical conversion element manufactured by any of the methods of Examples 1 to 3.

  In addition, a sheet feeding cassette 106 capable of stacking a large number of sheets 105 can be detachably attached to the lower part of the apparatus main body from the front side, and a manual feed tray 107 for manually feeding sheets 105 is provided. The paper 105 fed from the paper feed cassette 106 or the manual feed tray 107 can be taken in, and a required image is recorded by the printing mechanism 104, and then discharged to a paper discharge tray 108 mounted on the rear side. Make paper.

  The printing mechanism unit 104 holds a carriage 101 slidably in the main scanning direction by a main guide rod 109 and a sub guide rod 110 which are guide members horizontally mounted on left and right side plates (not shown). (Y), cyan (C), magenta (M), black (Bk) recording heads 102 that eject ink droplets of each color are arranged in a direction intersecting the main scanning direction with a plurality of ink ejection openings (nozzles), The ink droplet is ejected in the downward direction.

  In addition, each ink cartridge 103 for supplying ink of each color to the recording head 102 is replaceably mounted on the carriage 101. The ink cartridge 103 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the recording head 102 below, and a porous body filled with ink inside. The ink supplied to the recording head 102 by the force is maintained at a slight negative pressure. Further, although the heads of the respective colors are used here as the recording heads 102, a single head having nozzles for ejecting ink droplets of the respective colors may be used.

  Here, the carriage 101 is slidably fitted to the main guide rod 109 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 110 on the front side (upstream side in the paper conveyance direction). doing. In order to move and scan the carriage 101 in the main scanning direction, a timing belt 114 is stretched between a driving pulley 112 and a driven pulley 113 that are rotationally driven by a main scanning motor 111, and the timing belt 114 is attached to the carriage 101. The carriage 101 is reciprocally driven by forward and reverse rotations of the main scanning motor 111.

  On the other hand, in order to convey the paper 105 set in the paper feed cassette 106 to the lower side of the recording head 102, the paper feed roller 115 and the friction pad 116 for separating and feeding the paper 105 from the paper feed cassette 106 and the paper 105 are guided. A guide member 117 that rotates, a conveyance roller 118 that reverses and conveys the fed paper 105, a conveyance roller 119 that is pressed against the peripheral surface of the conveyance roller 118, and a feeding angle of the sheet 105 from the conveyance roller 118. A tip roller 120 is provided.

  The transport roller 118 is rotationally driven by a sub-scanning motor 121 through a gear train. A printing receiving member 122 is provided as a paper guide member that guides the paper 105 fed from the transport roller 118 on the lower side of the recording head 10.2 corresponding to the range of movement of the carriage 101 in the main scanning direction. . A conveyance roller 123 and a spur 124 that are rotationally driven to send the paper 105 in the paper discharge direction are provided on the downstream side of the printing receiving member 122 in the paper conveyance direction, and the paper 105 is further delivered to the paper discharge tray 108. A roller 125 and a spur 126, and guide members 127 and 128 that form a paper discharge path are disposed.

  At the time of recording, the recording head 102 is driven in accordance with the image signal while moving the carriage 101, thereby ejecting ink onto the stopped paper 105 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 105 has reached the recording area, the recording operation is terminated and the paper 105 is discharged. Further, a recovery device 129 for recovering the ejection failure of the recording head 102 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 101.

  The recovery device 129 includes a cap unit, a suction unit, and a cleaning unit. The carriage 101 is moved to the recovery device 129 side during printing standby, and the recording head 102 is capped by the capping means, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is 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 (nozzle) of the recording head 102 is sealed with a capping unit, and bubbles and the like are sucked out together with ink from the discharge port with a suction unit through a tube. Etc. are removed by the cleaning means, and the ejection failure is recovered. The sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir.

  Thus, since the inkjet recording apparatus 100 is equipped with the recording head 102 which is a droplet discharge head (inkjet head) having an electromechanical conversion element manufactured by any of the methods of Examples 1 to 3, There is no ink droplet ejection failure due to vibration plate drive failure, stable ink droplet ejection characteristics are obtained, and image quality is improved.

  As described above, even when PZT is used as the material of the electromechanical conversion film, Pb diffusion can be prevented by using oxide electrodes for the second electrode and the third electrode. In addition, by providing a metal electrode having a sufficiently low specific resistance as the first electrode, a sufficient current can be supplied to the common electrode when voltage driving is performed, and a large number of piezoelectric elements are driven simultaneously. In this case, a sufficient amount of displacement can be obtained without variation between elements. As a result, an electromechanical conversion element capable of obtaining stable ink ejection characteristics can be realized.

  The preferred embodiments and examples have been described in detail above, but the present invention is not limited to the above-described embodiments and examples, and the above-described embodiments are not deviated from the scope described in the claims. Various modifications and substitutions can be made to the embodiments.

DESCRIPTION OF SYMBOLS 10, 20 Electromechanical conversion element 11 Board | substrate 12 Diaphragm 13 1st electrode 14 2nd electrode 14a, 14b, 14c Patterned precursor coating film 15 Electromechanical conversion film 16 3rd electrode 17 SAM film 21 Insulating protective film 22 Fourth electrode 22x, 23x Contact hole 23 Fifth electrode 30 Droplet ejection head 35 Adhesion layer 37 Pressure chamber substrate 38 Nozzle 39 Nozzle plate 40 Pressure chamber 50, 82 Droplet ejection head 60 Inkjet coating device 61 Mounting base 62 Y Axis drive means 63 Substrate 64 Stage 65 X-axis support member 66 X-axis drive means 67 Z-axis drive means 68 Head base 69 Inkjet head 70 Colored resin ink supply pipe 81 Photoresist 100 Inkjet recording apparatus 101 Carriage 102 Recording head 103 Ink cartridge 1 04 Printing Mechanism 105 Paper 106 Paper Feed Cassette 107 Manual Tray 108 Paper Discharge Tray 109 Main Guide Rod 110 Subordinate Guide Rod 111 Main Scanning Motor 112 Drive Pulley 113 Driven Pulley 114 Timing Belt 115 Feed Roller 116 Friction Pad 117 Guide Member 118 Conveyance Rollers 119 and 123 Conveying rollers 120 Leading rollers 121 Sub-scanning motors 122 Printing receiving members 124 and 126 Spurs 125 Discharge rollers 127 and 128 Guide portions 129 Recovery devices

JP 2004-006645 A JP 2005-327920 A Patent 3019845

Claims (10)

A first step of forming a first electrode made of metal;
Forming a second electrode made of a conductive oxide on the first electrode, and patterning the second electrode;
A third step in which only the first electrode is surface-modified to make it water repellent;
A fourth step of forming an electromechanical conversion film on the patterned second electrode by an inkjet method;
And a fifth step of forming a third electrode made of a conductive oxide on the electromechanical conversion film.   The method of manufacturing an electromechanical transducer according to claim 1, wherein in the third step, the first electrode is surface-modified using a thiol compound.   3. The method for manufacturing an electromechanical transducer according to claim 1, further comprising a sixth step of hydrophilizing the second electrode before the fourth step.   The method for manufacturing an electromechanical transducer according to claim 3, wherein in the sixth step, the second electrode is surface-modified using a silane compound.   5. The method of manufacturing an electromechanical transducer according to claim 1, wherein the second electrode is manufactured by sputtering or a spin coater. In the second step, a region other than the second electrode formation region on the first electrode is subjected to surface modification to make it water repellent and to a second electrode formation region which is a hydrophilic region that is not water repellent. The method for producing an electromechanical transducer according to any one of claims 1 to 5, wherein the second electrode is formed using an inkjet method. The material of the second electrode is described by the chemical formula ABO ₃ , wherein A is one or more of Sr, Ba, Ca, and La, and B is one or more of Ru, Co, or Ni as a main component. The method for producing an electromechanical transducer according to any one of claims 1 to 6, which is a composite oxide or an oxide made of any of IrO ₂ and RuO ₂ .   The electricity according to any one of claims 1 to 7, further comprising a step of forming an insulating protective film having a contact hole covering the first electrode and the third electrode after the fifth step. A method for manufacturing a mechanical transducer.   The electromechanical transducer according to claim 8, further comprising a step of forming a fourth electrode made of metal that is electrically connected to the first electrode through the contact hole and serves as a common electrode on the insulating protective film. Manufacturing method.   10. The electric machine according to claim 8, further comprising a step of forming a fifth electrode made of metal which is electrically connected to the third electrode through the contact hole and becomes an individual electrode on the insulating protective film. 10. A method for manufacturing a conversion element.

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