JP2017191859A - Electromechanical conversion member, liquid discharge head, liquid discharge unit, and apparatus for discharging liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable electromechanical conversion member by suppressing peeling of a common electrode.SOLUTION: There is provided an electromechanical conversion member that has a diaphragm 15, a common electrode adhesion layer 160, a lower electrode 161, a piezoelectric substance 162, and an upper electrode 163 formed on a substrate 14, and defines one of the lower electrode 161 and upper electrode 163 as a common electrode and the other as an individual electrode. The electromechanical conversion member has an area A at least including corner parts of the common electrode and an area B including the piezoelectric substance 162 on the common electrode adhesion layer 160. The area A and the area B are materials different from each other, and the area A has a higher adhesion to the common electrode than that of the area B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromechanical conversion member, a liquid discharge head, a liquid discharge unit, and an apparatus for discharging liquid.

  In general, printers, facsimiles, copiers, plotters, or image forming apparatuses that combine a plurality of these functions include, for example, an ink jet recording apparatus that includes a liquid discharge head that discharges liquid such as ink.

  The liquid discharge head includes a nozzle that discharges a liquid droplet of ink or the like, a liquid chamber (also referred to as a pressure chamber, a pressure chamber, a discharge chamber, or the like) that communicates with the nozzle and stores a liquid, and a piezoelectric element. The structure provided with electromechanical conversion elements, such as these, is known. In this liquid discharge head, when a voltage is applied to the piezoelectric element, the piezoelectric element vibrates so as to deform the diaphragm that forms a part of the wall of the liquid chamber, and the liquid in the liquid chamber is caused by the deformation of the diaphragm. Pressurized and liquid droplets can be discharged from the nozzle.

  Two types of liquid ejection heads have been put to practical use, one using a longitudinal vibration mode piezoelectric actuator that extends and contracts in the axial direction of the piezoelectric element, and one using a flexural vibration mode piezoelectric actuator.

  Among them, for example, a flexural vibration mode actuator is used, for example, a uniform piezoelectric layer is formed over the entire surface of the diaphragm by a film forming technique, and this piezoelectric layer is shaped to correspond to a pressure generating chamber by a lithography method. It is known that a piezoelectric element is formed so as to be separated into each liquid chamber and independent of each liquid chamber.

  The piezoelectric element used for the actuator in the flexural vibration mode includes, for example, a lower electrode that is a common electrode, a PZT film (piezoelectric layer) formed on the lower electrode, and an individual electrode formed on the PZT film. It is known that it is comprised with the upper electrode which is. Further, an interlayer insulating film is formed on the upper electrode to insulate the lower electrode from the upper electrode, and a wiring electrically connected to the upper electrode through a contact hole opened in the interlayer insulating film. The provided structure is known (see Patent Documents 1 and 2).

  Generally, when these actuators are patterned by a lithography method, a resist stripping process, an ashing process, or the like is performed in order to remove an etching residue or a resist. At this time, in order to improve productivity, the resist stripping process is often performed in a batch manner.

  As shown in FIGS. 19 and 20, a substrate 70 (wafer) on which an electrode and a piezoelectric layer are formed is placed on a substrate cassette 71, and a release liquid 73 is discharged from a release liquid discharge nozzle 72 provided outside the base 70. Supply to the base 70. At this time, the base cassette 71 is processed by rotating around the rotation shaft 74 so that the stripping solution 73 spreads over the entire surface of the base 70. After this resist stripping process, as shown in the partially enlarged view of FIG. 20B, peeling of the common electrode 75 occurs and there is a problem that the yield is greatly reduced.

  Peeling in this resist peeling process tends to occur particularly at the corners of the common electrode 75 having a large pattern located outside the substrate 70. Further, the peeling interface is an interface between the common electrode and the adhesion layer, and is generated when the resist stripping solution attacks the common electrode corner.

  Conventionally, materials and configurations for improving the adhesion of the common electrode have been proposed. For example, in Patent Document 3, an attempt is made to improve the adhesion between both the diaphragm (oxide film) and the lower electrode Pt (metal film) by incompletely oxidizing TiOx in the adhesion layer as 0 <x <2. Has been made. Patent Document 3 aims to ensure adhesion, improve crystal characteristics and orientation characteristics of PZT, and improve withstand voltage characteristics and manufacturing yield.

  In Patent Document 4, an attempt is made to alleviate the attack of the resist stripping solution by suppressing the peeling by making the corners of the common electrode round.

  However, although peeling of the electrode has been greatly suppressed by the conventional technique, it has not been eradicated in practice, and further improvement is necessary.

  Accordingly, an object of the present invention is to provide a highly reliable electromechanical conversion member by suppressing peeling of the common electrode.

  In order to solve the above-described problems, the present invention provides a diaphragm, a common electrode adhesion layer, a lower electrode, a piezoelectric body, and an upper electrode formed on a substrate, wherein one of the lower electrode and the upper electrode is a common electrode, An electromechanical conversion member having the other as an individual electrode, the surface including the region A including at least the corner of the common electrode and the region B including the piezoelectric body on the surface of the common electrode adhesion layer, A and the region B are different materials, and the region A has higher adhesion to the common electrode than the region B.

  ADVANTAGE OF THE INVENTION According to this invention, peeling of a common electrode can be suppressed and a highly reliable electromechanical conversion member can be provided.

FIG. 3 is an example of a cross-sectional view illustrating a schematic configuration of a liquid ejection unit. It is another example of sectional drawing which shows schematic structure of a liquid discharge part. FIG. 2 is a cross-sectional view illustrating an example in which a plurality of liquid ejection units illustrated in FIG. 1 are arranged. FIG. 3 is a cross-sectional view illustrating an example in which a plurality of liquid ejection units illustrated in FIG. 2 are arranged. It is a figure which shows the example of the XRD pattern figure of a SRO film | membrane (111). (A) Top view of patterned upper electrode, (B) A-A ′ sectional view. (A) Top view of patterned upper electrode and piezoelectric body, (B) A-A ′ sectional view. (A) Top view of patterned upper electrode and piezoelectric body, (B) A-A ′ sectional view. It is a schematic diagram for demonstrating an example of the area | region A and the area | region B. FIG. It is a schematic diagram for demonstrating the other example of the area | region A and the area | region B. FIG. It is a schematic diagram which shows an example of the liquid discharge unit which concerns on this invention. It is a schematic diagram which shows the other example of the liquid discharge unit which concerns on this invention. It is a schematic diagram which shows the other example of the liquid discharge unit which concerns on this invention. It is a schematic diagram which shows the other example of the liquid discharge unit which concerns on this invention. 1 is a perspective view illustrating an example of a configuration of an image forming apparatus. 1 is a side view illustrating an example of a configuration of an image forming apparatus. It is a graph which shows the crystallinity of PZT in an Example and a comparative example. It is a graph which shows the corner part peeling rate in an Example and a comparative example. It is a conceptual diagram which forms a some piezoelectric element in a wafer. It is explanatory drawing about peeling of the corner part of the common electrode in a resist peeling process.

  Hereinafter, an electromechanical conversion member, a liquid discharge head, a liquid discharge unit, and a device for discharging a liquid according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

The present invention is an electric machine in which a diaphragm, a common electrode adhesion layer, a lower electrode, a piezoelectric body and an upper electrode are formed on a substrate, and one of the lower electrode and the upper electrode is a common electrode and the other is an individual electrode. A conversion member having a region A including at least a corner portion of the common electrode and a region B including the piezoelectric body on the surface of the common electrode adhesion layer, wherein the region A and the region B are different materials. The region A has higher adhesion to the common electrode than the region B.
Details will be described below.

  FIG. 1 and FIG. 2 are cross-sectional views in the arrangement direction of the liquid chambers showing a schematic configuration of a liquid discharge unit which is a basic component of the liquid discharge head, and only a portion corresponding to one liquid chamber is shown for convenience. In this embodiment shown in FIGS. 1 and 2, a nozzle substrate 12 having a nozzle 11 that discharges a liquid droplet of ink or the like, and a liquid chamber 13 (also referred to as a pressure chamber or the like) that communicates with the nozzle 11 and contains a liquid. ) Formed on the liquid chamber substrate 14 (hereinafter simply referred to as “substrate”). A vibration plate 15 serving as one wall surface of the liquid chamber 13 is formed on the substrate 14. A common electrode adhesion layer 160, a lower electrode 161, a piezoelectric body 162 (also referred to as an electro-mechanical conversion film) is formed on the vibration plate 15, A piezoelectric element 16 composed of the upper electrode 163 is provided.

  In the piezoelectric element 16 shown in FIG. 1, the lower electrode 161 is a common electrode, and the upper electrode 163 is an individual electrode. On the other hand, in the piezoelectric element 16 shown in FIG. 2, the lower electrode 161 is an individual electrode and the upper electrode 163 is a common electrode.

  The piezoelectric element 16 to which the drive voltage is applied vibrates so as to deform the vibration plate 15 between the substrate 14 and the piezoelectric element 16, and the liquid in the liquid chamber 13 is pressurized by the deformation of the vibration plate 15. , Droplets can be ejected from the nozzle 11.

  FIGS. 3 and 4 show examples in which a plurality of liquid ejection units shown in FIGS. 1 and 2 are arranged. As described above, one of the lower electrode 161 and the upper electrode 163 can be a common electrode and the other can be an individual electrode.

  The composite laminated substrate including the substrate 14, the piezoelectric element 16, and various electrodes configured as described above is an electromechanical conversion member called an actuator substrate.

  Next, the materials and methods of each part and member, which are constituent elements constituting the droplet discharge head, will be described more specifically.

<Board>
As the substrate 14, it is preferable to use a silicon single crystal substrate, and it is preferable to have a thickness of 100 to 600 μm. There are three types of plane orientations, (100), (110), and (111), but (100) and (111) are generally widely used in the semiconductor industry. A single crystal substrate having a plane orientation of 100) was mainly used.

Further, when a pressure chamber as shown in FIGS. 1 and 2 is manufactured, a silicon single crystal substrate is processed using etching. As an etching method in this case, it is common to use anisotropic etching. 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, while a structure having an inclination of about 54 ° can be produced in the plane orientation (100), a deep groove can be removed in the plane orientation (110), so that the arrangement density is increased while maintaining rigidity. I know you can. As this configuration, a single crystal substrate having a (110) plane orientation can be used. However, in this case, SiO ₂ which is a mask material is also etched, so it is preferable to use this point in consideration.

<Vibration plate>
In response to the force generated by the piezoelectric body, the base (vibration plate) is deformed and displaced, and ink droplets in the pressure chamber are ejected. Therefore, it is preferable that the diaphragm 15 has a predetermined strength. Examples of the material include those made of Si, SiO ₂ , Si ₃ N ₄ or the like by, for example, a CVD (Chemical Vapor Deposition) method.

Furthermore, it is preferable to select a material close to the linear expansion coefficient of the lower electrode and the electromechanical conversion film as shown in FIGS. In particular, as an electro-mechanical conversion film, since PZT (lead zirconate titanate) is generally used as a material, the linear expansion coefficient close to 8 × 10 ⁻⁶ (1 / K) is 5 A material having a linear expansion coefficient of × 10 ⁻⁶ to 10 × 10 ⁻⁶ is preferable, and a material having a linear expansion coefficient of 7 × 10 ^{−6 to} 9 × 10 ⁻⁶ is more preferable.

  Specific examples of the material include aluminum oxide, zirconium oxide, iridium oxide, ruthenium oxide, tantalum oxide, hafnium oxide, osmium oxide, rhenium oxide, rhodium oxide, palladium oxide, and compounds thereof. It can be produced by a spin coater using a Sol-gel method. The film thickness is preferably from 0.1 to 10 μm, more preferably from 0.5 to 3 μm. If it is smaller than this range, it will be difficult to process the pressure chamber as shown in FIGS. 1 and 2, etc. If it is larger than this range, the base will not be easily deformed and displaced, and ink droplet ejection will become unstable.

<Common electrode adhesion layer>
For example, the common electrode adhesion layer 160 is formed as follows. After the Ti film is formed by sputtering, the titanium film is thermally oxidized using an RTA (Rapid Thermal Annealing) apparatus at 650 to 800 ° C. for 1 to 30 minutes in an O ₂ atmosphere to form a titanium oxide film. To form the titanium oxide film, reactive sputtering may be used, but thermal oxidation of the titanium film at a high temperature is desirable. The production by reactive sputtering requires a special sputtering chamber configuration because the silicon substrate needs to be heated at a high temperature. Furthermore, the crystallinity of the titanium oxide film is better in the oxidation by the RTA apparatus than in the oxidation by a general furnace. This is because, according to oxidation in a normal heating furnace, a titanium film that is easily oxidized forms several crystal structures at a low temperature, and thus it is necessary to break it once. Therefore, oxidation by RTA having a high temperature rising rate is advantageous for forming a good crystal.

As materials other than Ti, materials such as Ta, Ir, and Ru are also preferable.
The film thickness is preferably 10 nm to 50 nm, and more preferably 15 nm to 30 nm. If it is less than this range, there is a concern about the adhesion, and if it is larger than this range, the quality of the crystal of the electrode film produced thereon will be affected.
Details of the configuration of the common electrode adhesion layer will be described later.

<Lower electrode (common electrode or individual electrode)>
The lower electrode is preferably made of metal or metal and oxide. Here, both are devised so as to suppress peeling and the like by putting an adhesion layer between the diaphragm and the metal film. Details of the metal electrode film and the oxide electrode film will be described.

<Metal electrode film>
Conventionally, platinum having high heat resistance and low reactivity has been used as the metal material of the metal electrode film, but it may not be said that it has sufficient barrier properties against lead. -Platinum group elements, such as rhodium, and these alloy films are also mentioned. Further, when platinum is used, it is preferable that the above-mentioned adhesion layer is laminated first because adhesion to the base (particularly SiO ₂ ) is poor.

As a manufacturing method, vacuum film formation such as sputtering or vacuum deposition is generally used.
As a film thickness, 80-200 nm is preferable and 100-150 nm is preferable. If the thickness is smaller than this range, a sufficient current cannot be supplied as a common electrode, and a problem may occur when ink is ejected. Further, when the thickness is larger than this range, the cost increases when an expensive material of a platinum group element is used. In the case of using platinum as a material, the surface roughness increases when the film thickness is increased, which affects the surface roughness and crystal orientation of the oxide electrode film and PZT produced thereon. In some cases, such a problem that a sufficient displacement for ink ejection cannot be obtained may occur.

<Oxide electrode film>
As a material for the oxide electrode film, SrRuO ₃ (hereinafter, abbreviated as “SRO” as appropriate) is preferably used. Other than the left, Sr _x (A) _(1-x) Ru _y (B) _(1-y) A = Ba, Ca, B = Co, Ni, x, y = 0 to 0.5 Such materials are also mentioned. The oxide electrode film can be produced by a film formation method such as sputtering. The film quality of the SrRuO ₃ thin film varies depending on the sputtering conditions. In particular, in order to place importance on the crystal orientation, for example, to align the (111) orientation of the SrRuO ₃ film as well as the Pt (111) of the metal electrode film, Is preferably formed by heating the substrate at 500 ° C. or higher.

  Regarding SRO film formation conditions, for example, after film formation at room temperature, thermal acidification is performed at a crystallization temperature (650 ° C.) by RTA treatment. In this case, the SRO film is sufficiently crystallized and a sufficient value is obtained as the specific resistance as an electrode. However, as the crystal orientation of the film, (110) is easily preferentially oriented, and the film is formed thereon. The PZT film is also easily (110) oriented.

  For example, the SRO crystallinity produced on Pt (111) has a lattice constant close to that of Pt and SRO, and therefore, in the usual θ-2θ measurement, the 2θ positions of SRO (111) and Pt (111) are overlapped for discrimination. Is difficult. With respect to Pt, diffraction lines cancel each other at a position where 2θ tilted by Psi = 35 ° is about 32 ° due to the disappearance rule, and no diffraction intensity is observed. Therefore, it is possible to confirm whether the SRO is preferentially oriented to (111) by tilting the Psi direction by about 35 ° and judging from the peak intensity where 2θ is about 32 °.

  FIG. 5 shows data when 2θ = 32 ° is fixed and Psi is shaken. At Psi = 0 °, almost no diffraction intensity is observed at SRO (110), and diffraction intensity is observed at around Psi = 35 °. From this, it can be confirmed that the SRO is (111) oriented in the film produced under this film forming condition. In addition, regarding the SRO produced by the room temperature film formation and the RTA process described above, the diffraction intensity of SRO (110) is observed when Psi = 0 °.

  Although details will be described later, when the amount of displacement after being driven is estimated to be deteriorated compared to the initial displacement when continuously operating as a piezoelectric actuator, the orientation of PZT has a great influence. (110) is insufficient in suppressing displacement deterioration. Further, when the surface roughness of the SRO film is observed, it affects the film formation temperature, and the surface roughness is very small from room temperature to 300 ° C. and becomes 2 nm or less.

  As for the roughness, the surface roughness (average roughness) measured by AFM (Atomic Force Microscope) is used as an index. Although the surface roughness is very flat, the crystallinity is not sufficient, and sufficient characteristics cannot be obtained with respect to initial displacement as a piezoelectric actuator of PZT formed after that and displacement deterioration after continuous driving. .

  The surface roughness is preferably 4 nm to 15 nm, and more preferably 6 nm to 10 nm. If this range is exceeded, the dielectric breakdown voltage of the PZT deposited thereafter is very poor and leaks easily. Therefore, in order to obtain crystallinity and surface roughness as described above, the film formation temperature is 500 ° C. to 700 ° C., preferably 520 ° C. to 600 ° C.

  Regarding the composition ratio of Sr and Ru after film formation, Sr / Ru is preferably 0.82 or more and 1.22 or less. If it is out of this range, the specific resistance increases, and sufficient conductivity as an electrode may not be obtained.

  Furthermore, the film thickness of the SRO film is preferably 40 nm to 150 nm, and more preferably 50 nm to 80 nm. If the thickness is smaller than this range, sufficient characteristics may not be obtained for initial displacement and displacement deterioration after continuous driving, and it is difficult to obtain a function as a stop etching layer for suppressing PZT overetching. . If this range is exceeded, the dielectric breakdown voltage of the PZT deposited thereafter is very poor and leaks easily.

The specific resistance is preferably 5 × 10 ⁻³ Ω · cm or less, and more preferably 1 × 10 ⁻³ Ω · cm or less. If this range is exceeded, sufficient contact resistance cannot be obtained at the interface with the upper electrode as a common electrode, and sufficient current cannot be supplied as the common electrode, which may cause problems when ink is ejected. is there.

<Piezoelectric body>
PZT was mainly used as the piezoelectric material. PZT is a solid solution of lead zirconate (PbZrO ₃ ) and titanic acid (PbTiO ₃ ), and the characteristics differ depending on the ratio. In general, the composition exhibiting excellent piezoelectric characteristics has a ratio of PbZrO ₃ and PbTiO ₃ of 53:47. When expressed by a chemical formula, Pb (Zr _0.53 , Ti _0.47 ) O ₃ , general PZT (53 / 47). 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. As a specific description thereof, (Pb _1-x , Ba) (Zr, Ti) O ₃ , (Pb _1-x , Sr) (Zr, Ti) O ₃ , which is a part of Pb of the A site, Ba or Sr. Is replaced with. 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.

  As a manufacturing method, it 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. When PZT is produced by the Sol-gel method, a PZT precursor solution can be produced by using lead acetate, zirconium alkoxide, and titanium alkoxide compounds as starting materials and dissolving them 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 piezoelectric film (PZT film) is obtained on the entire surface of the 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 the 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.

  The film thickness of the piezoelectric body 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.

  The relative dielectric constant is preferably in the range of 600 to 2000, and more preferably in the range of 1200 to 1600. At this time, when this value is not satisfied, sufficient displacement characteristics cannot be obtained, and when the value is larger than this value, polarization processing is not sufficiently performed, and sufficient characteristics cannot be obtained for displacement deterioration after continuous driving. Occur.

The crystallinity of the piezoelectric body is preferably high. When the crystallinity is high, the displacement (power to be discharged) increases, and the discharge efficiency is improved.
The crystallinity of the piezoelectric body is determined by X-ray diffraction measurement. When X-ray diffraction measurement is performed, peaks of (111), (100), (010), (001), (101), (110), and (011) appear in PZT. As described above, as the orientation of PZT, (110) is insufficient in suppressing displacement deterioration, and among these, (100) or (001) is preferably the main orientation. It is preferable that the peak of (100) or (001) is 80% or more of the entire peak. In this case, it can be said that the crystallinity is high.

<Upper electrode (common electrode or individual electrode)>
The upper electrode is preferably made of metal or oxide and metal.
Details of the oxide electrode film and the metal electrode film are described below.

<Oxide electrode film>
About the material of an oxide electrode film, it can be set as the structure similar to the oxide electrode film of a lower electrode. The film thickness is preferably 20 nm to 80 nm, and more preferably 40 nm to 60 nm. If it is thinner than this film thickness range, it is difficult to obtain sufficient characteristics for initial displacement and displacement deterioration characteristics. If this range is exceeded, the dielectric breakdown voltage of the PZT deposited thereafter is very poor and leaks easily.

<Metal electrode film>
About the material of a metal electrode film, it can be set as the structure similar to the metal electrode film of a lower electrode. The film thickness is preferably 30 to 200 nm, more preferably 50 to 120 nm. When the thickness is smaller than this range, a sufficient current cannot be supplied as the individual electrode, and a problem may occur when ink is ejected. Further, when the thickness is larger than this range, the cost increases when an expensive material of a platinum group element is used. In addition, when platinum is used as the material, the surface roughness increases as the film thickness increases, and process defects such as film peeling tend to occur when an electrode is produced through an insulating protective film. .

<Configuration of common electrode adhesion layer>
Details of the configuration of the common electrode adhesion layer will be described. First, a patterning example of the lower electrode 161, the piezoelectric body 162, and the upper electrode 163 will be described. FIG. 6 is a diagram schematically showing a top view (A) and a cross-sectional view AA ′ of FIG. 6 (A) when the upper electrode 163 is patterned. In FIG. 6, after the lower electrode 161 and the piezoelectric film 162a are formed, the upper electrode 163 is patterned.

  FIG. 7 shows an example in which the piezoelectric body 162 is patterned with respect to FIG. FIG. 7 is a diagram schematically showing a top view (A) and a cross-sectional view A-A ′ of FIG. In the example shown in FIG. 7, the lower electrode 161 is a common electrode, and the upper electrode 163 is an individual electrode.

  On the other hand, another form is shown in FIG. FIG. 8 is another example in which the piezoelectric body 162 is patterned with respect to FIG. FIG. 8 schematically shows a top view (A) and a cross-sectional view (A) taken along the line A-A ′ of FIG. 8A when the piezoelectric body 162 is patterned similarly to FIG. 7. Thus, in the present invention, the lower electrode 161 may be a common electrode, the upper electrode 163 may be an individual electrode, the lower electrode 161 may be an individual electrode, and the upper electrode 163 may be a common electrode.

  As described in FIGS. 19 and 20, when the actuator is patterned by the lithography method, a resist stripping process, an ashing process, and the like are performed to remove the etching residue and the resist. Therefore, the resist stripping process is often performed in a batch manner.

  As shown in FIGS. 19 and 20, a substrate 70 (wafer) on which an electrode and a piezoelectric layer are formed is placed on a substrate cassette 71, and a release liquid 73 is discharged from a release liquid discharge nozzle 72 provided outside the base 70. Supply to the base 70. At this time, the base cassette 71 is processed by rotating around the rotation shaft 74 so that the stripping solution 73 spreads over the entire surface of the base 70. After this resist stripping process, as shown in the partially enlarged view of FIG. 20B, peeling of the common electrode 75 occurs and there is a problem that the yield is greatly reduced.

  Peeling in this resist peeling process tends to occur particularly at the corners of the common electrode 75 having a large pattern located outside the substrate 70. Further, the peeling interface is an interface between the common electrode and the adhesion layer, and is generated when the resist stripping solution attacks the common electrode corner.

  On the other hand, in the present invention, on the surface of the common electrode adhesion layer 160, a region including at least the corner of the common electrode 161 (hereinafter referred to as region A) and a region including the piezoelectric body 162 (hereinafter referred to as region B). The region A and the region B are made of different materials, and the region A has higher adhesion to the common electrode 161 than the region B. As described above, in the present invention, by improving the adhesion layer, peeling in the resist stripping process can be suppressed, and a highly reliable electromechanical conversion member can be obtained.

A configuration example of the common electrode adhesion layer 160 in the present invention will be described with reference to FIGS. 9 and 10 are schematic views when the common electrode adhesion layer 160 is viewed from above.
In the example shown in FIG. 9A, Ti is formed on the diaphragm 15 by sputtering, and then TiO ₂ is formed by thermal oxidation and patterned into a sheet shape. In FIG. 9B, Ti is further formed as shown in FIG. 9A, and the Ti film on TiO ₂ is removed by etching. Thereby, in the common electrode adhesion layer 160, the region A (common electrode adhesion layer 160a) including the corner portion 161c of the common electrode is made of Ti, and the region B (common electrode adhesion layer 160b) including the piezoelectric body 162 is TiO _2. It will be composed of.
Note that in FIG. 9B, only one corner 161c of the common electrode is shown, and the others are omitted.

  Thereafter, as shown in FIG. 9C, a piezoelectric body 162 and an upper electrode 163 are formed on the common electrode adhesion layer 160. As shown in the drawing, the patterned upper electrode 163 (individual electrode) and the piezoelectric body 162 are formed in the region B (common electrode adhesion layer 160b), and include the corner 161c of the lower electrode 161 (common electrode). A common electrode adhesion layer 160a is formed in (Area A). Note that in FIG. 9C, the reference numeral of the lower electrode 161 (common electrode) is omitted (the same applies to FIG. 10C).

Another configuration example of the common electrode adhesion layer 160 is shown in FIG. In the example shown in FIG. 10, each layer is formed as in FIG. FIG. 10A is different from FIG. 9A in the area when patterning TiO ₂ . In FIG. 9, the region A (common electrode adhesion layer 160 a) is formed so as to surround the region B (common electrode adhesion layer 160 b) including the corner 161 c of the common electrode. It is formed at the four corners. Then, as shown in FIGS. 10B and 10C, a region A (common electrode adhesion layer 160a) and a region B (common electrode adhesion layer 160b) are formed.

Further, the region A in the common electrode adhesion layer is preferably alloyed with the common electrode. Thereby, the contact | adhesion power with a common electrode improves more and peeling of a common electrode can be suppressed more.
The alloying method is not particularly limited, and can be performed by a known method. For example, the method etc. which heat-process at 500-700 degreeC with heating apparatuses, such as RTA, are mentioned.

In a general electromechanical conversion member, it is considered that peeling occurs due to the direct attack of the stripping solution at the interface between the common electrode having a weak adhesion and the adhesion layer. Platinum (Pt) is well known as a material for the common electrode, and titanium (Ti) and titanium oxide (TiO ₂ ) are well known as an adhesion layer between platinum (Pt) and the substrate. When titanium (Ti) is used for the adhesion layer, platinum (Pt) has a large adhesion force due to the bonding between metals, but titanium (Ti) diffuses into platinum (Pt) and the piezoelectric body, resulting in poor piezoelectric properties. Become. On the other hand, when titanium oxide (TiO ₂ ) is used, diffusion is suppressed and good piezoelectric characteristics can be obtained, but the bond with platinum (Pt) is weak and the adhesion is lower than that of titanium (Ti). Become.

Considering the above, as a material of the common electrode and the common electrode adhesion layer, it is preferable that the region A in the common electrode adhesion layer 160 is Ti, the region B is TiO ₂ , and the common electrode is Pt. In this case, the piezoelectric characteristics can be improved while maintaining the adhesion between the common electrode and the common electrode adhesion layer.

  Next, an example of an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. FIG. 11 is an explanatory plan view of the main part of the apparatus, and FIG. 12 is an explanatory side view of the main part of the apparatus.

  This apparatus is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning moving mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 spans the left and right side plates 491A and 491B and holds the carriage 403 so as to be movable. The carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 spanned between the driving pulley 406 and the driven pulley 407.

  A liquid discharge unit 440 in which the liquid discharge head 404 and the head tank 441 according to the present invention are integrated is mounted on the carriage 403. The liquid discharge head 404 of the liquid discharge unit 440 discharges, for example, yellow (Y), cyan (C), magenta (M), and black (K) liquids. The liquid ejection head 404 is mounted with a nozzle row composed of a plurality of nozzles 11 arranged in the sub-scanning direction orthogonal to the main scanning direction, and the ejection direction facing downward.

  The liquid stored in the liquid cartridge 450 is supplied to the head tank 441 by the supply mechanism 494 for supplying the liquid stored outside the liquid discharge head 404 to the liquid discharge head 404.

  The supply mechanism 494 includes a cartridge holder 451 that is a filling unit for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, and the like. The liquid cartridge 450 is detachably attached to the cartridge holder 451. Liquid is fed from the liquid cartridge 450 to the head tank 441 by the liquid feeding unit 452 via the tube 456.

  This apparatus includes a transport mechanism 495 for transporting the paper 410. The transport mechanism 495 includes a transport belt 412 serving as transport means, and a sub-scanning motor 416 for driving the transport belt 412.

  The conveyance belt 412 adsorbs the paper 410 and conveys it at a position facing the liquid ejection head 404. The transport belt 412 is an endless belt and is stretched between the transport roller 413 and the tension roller 414. The adsorption can be performed by electrostatic adsorption or air suction.

  The transport belt 412 rotates in the sub-scanning direction when the transport roller 413 is rotationally driven by the sub-scanning motor 416 via the timing belt 417 and the timing pulley 418.

  Further, on one side of the carriage 403 in the main scanning direction, a maintenance / recovery mechanism 420 that performs maintenance / recovery of the liquid ejection head 404 is disposed on the side of the transport belt 412.

  The maintenance / recovery mechanism 420 includes, for example, a cap member 421 for capping the nozzle surface (surface on which the nozzle 11 is formed) of the liquid ejection head 404, a wiper member 422 for wiping the nozzle surface, and the like.

  The main scanning movement mechanism 493, the supply mechanism 494, the maintenance / recovery mechanism 420, and the transport mechanism 495 are attached to a housing including the side plates 491A and 491B and the back plate 491C.

  In this apparatus configured as described above, the paper 410 is fed and sucked onto the transport belt 412, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412.

  Therefore, the liquid ejection head 404 is driven in accordance with the image signal while moving the carriage 403 in the main scanning direction, thereby ejecting liquid onto the stopped paper 410 to form an image.

  Thus, since this apparatus includes the liquid ejection head according to the present invention, a high-quality image can be stably formed.

  Next, another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 13 is an explanatory plan view of the main part of the unit.

  The liquid discharge unit includes a casing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning moving mechanism 493, a carriage 403, and a liquid among the members constituting the liquid discharge device. The discharge head 404 is configured.

  Note that a liquid discharge unit in which at least one of the above-described maintenance and recovery mechanism 420 and the supply mechanism 494 is further attached to, for example, the side plate 491B of the liquid discharge unit may be configured.

  Next, still another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 14 is an explanatory front view of the unit.

  This liquid discharge unit includes a liquid discharge head 404 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

  The flow path component 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path component 444. In addition, a connector 443 that is electrically connected to the liquid ejection head 404 is provided above the flow path component 444.

  In the present application, the “apparatus for discharging liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and test cells. Yes, unless specifically limited, includes everything that the liquid adheres to.

  The material of the above-mentioned “applicable liquid” is temporary liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, textiles for clothing, etc. However, it only needs to be attached.

  In addition, “liquid” includes ink, processing liquid, DNA sample, resist, pattern material, binder, modeling liquid, or a solution and dispersion containing amino acid, protein, calcium, and the like.

  In addition, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulator for granulating raw material fine particles by spraying a composition liquid dispersed in a solution through a nozzle.

  A “liquid ejection unit” is a unit in which functional parts and mechanisms are integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated, such as the liquid discharge unit 440 shown in FIG. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. Further, as shown in FIG. 13, there is a liquid discharge unit in which a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

  Further, as shown in FIG. 14, as a liquid discharge unit, there is a unit in which a liquid discharge head and a supply mechanism are integrated by connecting a tube to a liquid discharge head to which a head tank or a flow path component is attached. .

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  The “liquid discharge head” is not limited to the pressure generating means to be used. For example, in addition to the piezoelectric actuator as described in the above embodiment (a multilayer piezoelectric element may be used), a thermal actuator using an electrothermal conversion element such as a heating resistor, a diaphragm and a counter electrode are included. An electrostatic actuator or the like may be used.

  In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling” and the like in the terms of the present application are all synonymous.

  Next, an example of an apparatus for ejecting liquid according to the present invention will be described with reference to FIGS. FIG. 15 is an explanatory perspective view of the apparatus, and FIG. 16 is an explanatory side view of a mechanism portion of the apparatus. Hereinafter, an ink jet recording apparatus will be described as an example, but the apparatus for ejecting liquid is not limited to this.

  The ink jet recording apparatus of the present embodiment includes a carriage movable in the main scanning direction inside the recording apparatus main body 81, a recording head comprising the ink jet head embodying the present invention mounted on the carriage, and an ink cartridge for supplying ink to the recording head. A paper feed cassette (or a paper feed tray) 84 on which a large number of sheets 83 can be stacked from the front side is freely detachable at the lower part of the apparatus main body 81. The manual tray 85 for manually feeding the paper 83 can be opened, the paper 83 fed from the paper feed cassette 84 or the manual tray 85 is taken in, and the printing mechanism After recording a required image by the unit 82, the image is discharged onto a discharge tray 86 mounted on the rear side.

  The printing mechanism 82 holds a carriage 93 slidably in the main scanning direction by 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). (Y), cyan (C), magenta (M), black (Bk) A head 94 comprising an ink jet head according to the present invention for ejecting ink droplets of each color has a plurality of ink ejection openings (nozzles) as the main scanning direction. They are arranged in the intersecting direction and mounted with the ink droplet ejection direction facing downward. In addition, each ink cartridge 95 for supplying ink of each color to the head 94 is replaceably mounted on the carriage 93.

  The ink cartridge 95 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside, and the capillary force of the porous body. Thus, the ink supplied to the inkjet head is maintained at a slight negative pressure. Further, although the heads 94 of the respective colors are used here as the recording heads, a single head having nozzles for ejecting ink droplets of the respective colors may be used.

  Here, the carriage 93 is slidably fitted to the main guide rod 91 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 92 on the front side (upstream side in the paper conveyance direction). doing. 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 a main scanning motor 97, and the timing belt 100 is moved to the carriage 93. The carriage 93 is driven to reciprocate by forward and reverse rotation of the main scanning motor 97.

  On the other hand, in order to convey the paper 83 set in the paper feed cassette 84 to the lower side of the head 94, the paper feed roller 101 and the friction pad 102 for separating and feeding the paper 83 from the paper feed cassette 84 and the paper 83 are guided. A guide member 103, a transport roller 104 that reverses and transports the fed paper 83, a transport roller 105 that is pressed against the peripheral surface of the transport roller 104, and a leading end that defines a feed angle of the paper 83 from the transport roller 104 A roller 106 is provided. The transport roller 104 is rotationally driven by a sub-scanning motor 107 through a gear train.

  A printing receiving member 109 is provided as a paper guide member that guides the paper 83 sent from the transport roller 104 below the recording head 94 in accordance with the movement range of the carriage 93 in the main scanning direction. A conveyance roller 111 and a spur 112 that are rotationally driven to send the paper 83 in the paper discharge direction are provided on the downstream side of the printing receiving member 109 in the paper conveyance direction, and the paper 83 is further delivered to the paper discharge tray 86. A roller 113 and a spur 114, and guide members 115 and 116 that form a paper discharge path are disposed.

  At the time of recording, the recording head 94 is driven according to the image signal while moving the carriage 93, thereby ejecting ink onto the stopped sheet 83 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 83 has reached the recording area, the recording operation is terminated and the paper 83 is discharged.

  Further, a recovery device 117 for recovering defective ejection of the head 94 is disposed 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 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 head 94 is sealed with a capping unit, and bubbles and the like are sucked out from the discharge port with the suction unit through the tube. Is removed by the cleaning means to recover the ejection failure. Further, the sucked ink is discharged to 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.

  Thus, since this inkjet recording apparatus is equipped with the inkjet head produced in Example 1 of the present invention, there is no ink droplet ejection failure due to vibration plate drive failure, and stable ink droplet ejection characteristics can be obtained. , Improve the image quality.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example.

Example 1
A diaphragm 15 composed of SiO ₂ and Si ₃ N ₄ was formed on a 6-inch silicon wafer by a CVD method, and a Ti film (thickness 30 nm) was formed as a common electrode adhesion layer 160 by a sputtering apparatus. Thereafter, thermal oxidation was performed at 750 ° C. using RTA to form a TiO ₂ film.
Next, as shown in FIG. 9A, the TiO ₂ film was formed into a sheet by etching after forming a resist pattern by photolithography. After the patterning, a Ti film (30 nm) is further formed, and the Ti film on the TiO ₂ film is removed by etching. As shown in FIG. 9B, the common electrode adhesion layer 160 composed of Ti and TiO ₂ is obtained. Formed.
Subsequently, as a metal film of the lower electrode 161 (common electrode), a Pt film (film thickness: 100 nm) was formed by sputtering. The substrate was heated at 550 ° C. during the sputtering film formation.

Next, a solution adjusted to Pb: Zr: Ti = 114: 53: 47 was prepared as a piezoelectric film, and a film was formed by spin coating.
For the synthesis of a specific precursor coating solution, lead acetate trihydrate, isopropoxide titanium, and normal propoxide zirconium were used as starting materials. Crystal water of lead acetate was dissolved in methoxyethanol and then dehydrated. The lead amount is excessive with respect to the stoichiometric composition. This is to prevent crystallinity deterioration due to so-called lead loss during heat treatment. Isopropoxide titanium and normal propoxide 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 0.5 mol / l. Using this solution, a film was formed by spin coating. After the film formation, the film was dried at 120 ° C. and thermally decomposed at 500 ° C. After thermal decomposition treatment of the third layer, crystallization heat treatment (temperature: 750 ° C.) was performed by RTA (rapid heat treatment). At this time, the film thickness of PZT was 240 nm. This process was performed a total of 8 times (24 layers) to obtain a PZT film thickness of about 2 μm. The crystallinity of PZT was evaluated using XRD for the samples prepared so far.

Next, an SrRuO ₃ film (film thickness 40 nm) was formed as an oxide film of the upper electrode 163 (individual electrode), and a Pt film (film thickness 125 nm) was formed as a metal film by sputtering. Then, after forming a resist pattern by ordinary photolithography, etching the Pt film and oxide film, etching with a resist stripper using an amine-based stripper for 30 minutes, and using an asher 3 The upper electrode 163 was patterned by performing an ashing process for a minute. Similarly, after forming a resist pattern by photolithography, the piezoelectric film was etched, resist stripping and ashing were performed, and the piezoelectric film was patterned. Next, after forming a resist pattern by photolithography, resist peeling treatment and ashing treatment were performed, and the lower electrode 161 (common electrode) was patterned into a sheet shape.

A mode at this stage is illustrated in FIG. The patterned upper electrode 163 (individual electrode) and piezoelectric body 162 are in the common electrode adhesion layer 160b (TiO ₂ ) area, and the area including the corner portion 161c of the lower electrode (common electrode) is in the common electrode adhesion layer 160a (Ti). Exists.

  In the electromechanical conversion member produced so far, the number of peeling at the corner of the lower electrode 161 (common electrode) was counted, and the corner peeling rate was calculated. As shown in FIG. 19, 32 electromechanical conversion members are formed on the base, and four lower electrodes (common electrodes) are formed on each electromechanical conversion member. Further, the parameter of the corner of the lower electrode (common electrode) in the substrate is the number of electromechanical conversion members (32) × the number of common electrodes (4) × the number of corners (4) = 512. is there.

(Example 2)
In Example 1, an electromechanical conversion member similar to that in Example 1 was produced except that the common electrode adhesion layer was patterned as shown in FIG. Similarly, the crystallinity measurement of PZT by XRD, the number of peeling at the corners of the lower electrode (common electrode) were counted, and the corner peeling rate was calculated.

(Comparative Example 1)
In Example 1, the electromechanical conversion member similar to Example 1 was produced except that the common electrode adhesion layer was not patterned and only TiO ₂ was used. Similarly, the crystallinity measurement of PZT by XRD, the number of peeling at the corner of the lower electrode (common electrode) was counted, and the corner peeling rate was calculated.

(Comparative Example 2)
In Example 1, the electromechanical conversion member similar to Example 1 was produced except that the common electrode adhesion layer was not patterned and only Ti was formed. Similarly, the crystallinity measurement of PZT by XRD, the number of peeling at the corner of the lower electrode (common electrode) was counted, and the corner peeling rate was calculated.

(Evaluation of crystallinity and peeling)
FIG. 17 shows the crystallinity of the piezoelectric PZT measured in Examples 1 and 2 and Comparative Examples 1 and 2, and FIG. 18 shows the counted corner peeling rate.
First, regarding the crystallinity of PZT, Examples 1 and 2 and Comparative Example 1 are good, but Comparative Example 2 is low. This is presumably because non-oxidized Ti diffuses to the lower electrode Pt layer and the piezoelectric PZT layer, and the crystal structure of the lower electrode Pt layer and the crystal structure of the piezoelectric PZT formed thereon are disturbed. As a result, the piezoelectric constant is lowered, and the characteristics as an electromechanical conversion member are considered to be lowered. In the electrical conversion member obtained in Comparative Example 2, the crystallinity is poor and the displacement is small, so the discharge efficiency is poor.

  Next, regarding the peeling rate of the corners of the lower electrode (common electrode), Examples 1 and 2 and Comparative Example 2 were 0%, while Comparative Example 1 was 47% peeled off. With respect to the fact that peeling did not occur in Examples 1 and 2 and Comparative Example 2, it seems that Ti of the adhesion layer at the corner where peeling easily occurs and the lower electrode Pt are alloyed, and the adhesion strength is sufficient. On the other hand, in Comparative Example 1, the corners where peeling is likely to occur are the oxide adhesion layer and the metal electrode layer, and the bonding is weakly performed by intermolecular force or electrostatic force, so it is considered that peeling occurred.

  From the above results, the common electrode adhesion layer is patterned as in Examples 1 and 2, and an appropriate material is formed at the corner where the piezoelectric PZT is formed and the corner where peeling easily occurs. An electromechanical conversion member that does not deteriorate can be manufactured.

(Discharge evaluation)
A liquid discharge head was manufactured by mounting wiring and a driving unit on the electromechanical conversion member manufactured in Example 1, further forming a pressure chamber as shown in FIGS. 1 and 3, and joining nozzles. An applied voltage of −10 to 30 V was applied by a simple Push waveform using ink whose viscosity was adjusted to 5 cp with this liquid discharge head. When the discharge state at this time was confirmed, it was confirmed that all the nozzle holes could be discharged. Furthermore, when continuous discharge durability evaluation was performed, it confirmed that it could discharge without a problem even after the drive of 10 ¹⁰ times.

11 Nozzle 12 Nozzle plate 13 Liquid chamber 14 Substrate 15 Vibrating plate 16 Piezoelectric element 70 Base (wafer)
Reference Signs List 71 Base cassette 72 Stripping liquid discharge nozzle 73 Stripping liquid 74 Rotating shaft 75 Common electrode 75p Peeling 81 Recording device main body 82 Printing mechanism 83 Paper 84 Paper feed cassette 85 Manual feed tray 86 Paper discharge tray 91 Main guide rod 92 Sub guide rod 93 Carriage 94 Liquid Discharge Head 95 Ink Cartridge 97 Main Scanning Motor 98 Drive Pulley 99 Driven Pulley 100 Timing Belt 101 Paper Feed Roller 102 Friction Pad 103 Guide Member 104 Transport Roller 105 Transport Roller 106 Leading Roller 107 Sub Scan Motor 109 Substrate Receiving Member 111 Transport Roller 112, 114 Spur 113 Discharge roller 115, 116 Guide member 117 Recovery device 160, 160a, 160b Common electrode adhesion layer 161 Lower electrode 162 Piezoelectric body 162a Electrical film 163 Upper electrode 200 Support substrate 300 Nozzle substrate 401 Guide member 403 Carriage 404 Liquid ejection head 405 Main scanning motor 406 Drive pulley 407 Driven pulley 408 Timing belt 410 Paper 412 Conveying belt 413 Conveying roller 414 Tension roller 416 Sub scanning motor 417 Timing belt 418 Timing pulley 420 Maintenance / recovery mechanism 421 Cap member 422 Wiper member 440 Liquid discharge unit 441 Head tank 442 Cover 443 Connector 444 Flow path component 450 Liquid cartridge 451 Cartridge holder 452 Liquid supply unit 456 Tube 491A, 491B Side plate 491C Back plate 491C Main scanning movement mechanism 494 Supply mechanism 495 Conveyance mechanism

Japanese Patent No. 3365485 Japanese Patent No. 4218309 JP 2013-161896 A JP 2016-13651 A

Claims (7)

A diaphragm, a common electrode adhesion layer, a lower electrode, a piezoelectric body, and an upper electrode are formed on a substrate, and the electromechanical conversion member has one of the lower electrode and the upper electrode as a common electrode and the other as an individual electrode. And
The surface of the common electrode adhesion layer has a region A including at least a corner of the common electrode, and a region B including the piezoelectric body,
The electromechanical conversion member, wherein the region A and the region B are made of different materials, and the region A has higher adhesion to the common electrode than the region B.   The electromechanical conversion member according to claim 1, wherein the region A is alloyed with the common electrode. The electromechanical conversion member according to claim 1, wherein the region A is Ti, the region B is TiO ₂ , and the common electrode is Pt. A liquid discharge head having a liquid chamber communicating with a nozzle for discharging droplets, and pressure generating means for generating pressure in the liquid in the liquid chamber,
The liquid discharge head, wherein the pressure generating unit includes the electromechanical conversion member according to claim 1.   A liquid discharge unit comprising the liquid discharge head according to claim 4.   A head tank for storing liquid to be supplied to the liquid discharge head, a carriage on which the liquid discharge head is mounted, a supply mechanism for supplying liquid to the liquid discharge head, a maintenance / recovery mechanism for maintaining and recovering the liquid discharge head, and the liquid 6. The liquid discharge unit according to claim 5, wherein the liquid discharge head is integrated with at least one of a main scanning movement mechanism that moves the discharge head in the main scanning direction. An apparatus for discharging liquid, comprising the liquid discharge head according to claim 4 or the liquid discharge unit according to claim 5 or 6.