JP2007288153A - Piezoelectric actuator, method for producing same, liquid droplet jetting apparatus, and method for producing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent damage as much as possible by reducing stress concentration caused in a portion, even if the portion whose thickness rapidly changes occurs in a thin film layer formed by a film forming process by AD method. <P>SOLUTION: A film-forming nozzle 52 is moved, so that an edge of areas with a piezoelectric material layer 31 formed therein by the film-forming nozzle 52 moving relative to a vibration plate 30, is positioned outside deformable portions 30a of a vibration plate 30 and overlaps with restricted portions 30b, when seeing from the direction orthogonal to the vibration plate 30. This reduces stress concentration on a portion of the piezoelectric layer 31 corresponding to a boundary portion of the deposition areas. Therefore, the damage of the piezoelectric material layer 31 is prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piezoelectric actuator manufacturing method, a droplet ejecting apparatus manufacturing method, a piezoelectric actuator, and a droplet ejecting apparatus.

  Conventionally, a substrate made of a metal material, a thin film piezoelectric material layer made of a ferroelectric piezoelectric ceramic material such as PZT (lead zirconate titanate), and an electrode for generating an electric field in the piezoelectric material layer There is known a piezoelectric actuator comprising: This piezoelectric actuator drives a target by deforming a substrate using expansion and contraction of a piezoelectric material layer when an electric field is applied.

On the other hand, as one method for forming a thin film on the surface of a flat substrate, an aerosol containing a particulate thin film material and a carrier gas is sprayed from a deposition nozzle toward the substrate, and the particles are generated by the collision energy at that time. There is known an aerosol deposition method (hereinafter referred to as AD method) in which a film is deposited on a substrate surface. Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-122341) discloses a film forming method in which a piezoelectric material layer is formed on a substrate surface in a thin film shape using this AD method. According to this film forming method, while the film forming nozzle having the slit is moved relative to the substrate, the aerosol containing the particles of the piezoelectric material and the carrier gas is sprayed from the slit to the substrate, so that the particles of the piezoelectric material are placed on the substrate. To form a piezoelectric material layer on the substrate.
JP 2004-122341 A

    When forming a thin film layer on a substrate by the AD method, it is most common to spray aerosol while moving the film forming nozzle relative to the substrate in a predetermined direction (scanning direction). In the band-shaped thin film layer formed on the substrate, a film thickness distribution is likely to occur in the width direction that is a direction orthogonal to the scanning direction (see FIG. 10 of Patent Document 1). As a factor, first, since the flow velocity distribution of the aerosol ejected from the slit is not uniform, a difference occurs in the speed at which particles are deposited. Another factor is that the aerosol sprayed from the slit at a predetermined angle scrapes off a part of the film previously formed on the substrate, and as a result, the deposition of particles in the region is delayed. It has become.

    Therefore, when a piezoelectric material layer is formed by the AD method, a film thickness distribution is likely to occur in the formed piezoelectric material layer in a direction orthogonal to the moving direction of the film forming nozzle. May occur.

    The object of the present invention is to reduce the stress concentration generated in the thin film layer formed by the film formation process by the AD method, and to prevent damage as much as possible. It is an object to provide a piezoelectric actuator capable of satisfying the requirements and a manufacturing method thereof.

Means for Solving the Problems and Effects of the Invention

  According to the first aspect of the present invention, a substrate having a plurality of deformable portions and a restraining portion for partitioning the deformable portion, and the piezoelectric material layer and the deformable portion are disposed on the substrate and overlap with the substrate. A method of manufacturing a piezoelectric actuator comprising a plurality of thin film layers including drive electrodes disposed on the substrate, comprising: providing the substrate; and forming the plurality of thin film layers on the substrate; The step of forming the thin film layer includes the step of forming at least one thin film layer of the plurality of thin film layers on a plurality of regions partitioned adjacent to each other on the substrate and a boundary portion between the adjacent regions. The aerosol containing the particles forming the at least one thin film layer and the carrier gas is sprayed from the film forming nozzle to each region while moving the film forming nozzle relative to each other so as to be positioned outside the deformable part. Method for manufacturing a piezoelectric actuator comprising to form is provided.

  When a thin film layer is formed on the substrate by spraying aerosol while moving the film forming nozzle relative to the substrate in a certain direction, the formed thin film layer has a direction perpendicular to the moving direction of the film forming nozzle. Film thickness distribution is likely to occur. Therefore, when a thin film layer is formed in each of these regions by moving the film forming nozzles relative to a plurality of adjacent regions on the substrate, a film thickness distribution is generated in each of the film forming regions. In a portion where the film formation region is adjacent (boundary portion), a rapid change in film thickness is likely to occur in the thin film layer. Therefore, for example, when the thin film layer is a piezoelectric material layer, the thickness changes rapidly when an electric field is applied to the piezoelectric material layer during the polarization process in the manufacturing stage or when the piezoelectric actuator drives the target, and the piezoelectric material layer is deformed. In particular, a large stress concentration tends to occur at the boundary portion. The inventors have found that this stress concentration can cause cracks at the boundary and cause damage to the piezoelectric material layer.

  According to the method for manufacturing a piezoelectric actuator of the present invention, at least one thin film layer of the piezoelectric actuator has a boundary portion between a plurality of regions, that is, a region where the drive electrode and the deformable portion of the substrate overlap, that is, the piezoelectric material by the drive electrode. It is located outside the region where the electric field is directly applied to the layer and the substrate is greatly deformed (active portion), and does not overlap this region. For this reason, even if a sudden change in film thickness occurs in the thin film layer at the boundary of the film formation region, the stress concentration generated in that portion is reduced, and the thin film layer is prevented from being damaged. Rise.

  In the method for manufacturing a piezoelectric actuator of the present invention, a slit for injecting aerosol may be formed in the film forming nozzle, and the slit may have a size such that an area of the aerosol to be injected on the substrate covers at least one pressure chamber. You may have. By using a slit having such a size, it is possible to form a film so that the boundary part of the film formation region is outside the active part.

  In the method for manufacturing a piezoelectric actuator of the present invention, any deformable portion can be formed in a plurality of divided regions.

  In the method for manufacturing a piezoelectric actuator of the present invention, in the step of forming the thin film layer, each of the plurality of regions is arranged such that the boundary portion overlaps the restraining portion when viewed from a direction orthogonal to the substrate. On the other hand, the film forming nozzle can be moved. According to this manufacturing method, the boundary portion of the region where the thin film layer is formed by the relative movement of the deposition nozzle with respect to the substrate overlaps with the restraining portion of the substrate and does not overlap with the deformable portion. Even when a sudden change in film thickness occurs in the thin film layer at the boundary portion of the film region, the stress concentration generated in that portion is reduced.

  In the method for manufacturing a piezoelectric actuator of the present invention, the substrate may have a row of deformable portions in which a plurality of the deformable portions are arranged in a predetermined direction. In the step of forming the thin film layer, the substrate is formed. The film nozzle may be moved at a time in the predetermined direction with respect to the substrate, thereby forming the film all over the region overlapping the row of the deformable portions as viewed from the direction orthogonal to the substrate. According to this manufacturing method, the boundary portion of the film formation region of the thin film layer does not exist in the region overlapping the deformable portion, and the stress concentration in that portion is reduced. In this manufacturing method, a method of forming a thin film layer on an area overlapping with a row of deformable portions is performed by moving the film forming nozzle only once, and a film forming nozzle for one film forming area. And a method of moving particles a plurality of times and depositing particles on the film formation region.

  In the piezoelectric actuator manufacturing method of the present invention, in the step of forming the thin film layer, an aerosol containing particles of piezoelectric material and a carrier gas is ejected from the film forming nozzle onto the substrate, and the piezoelectric material Layers can be deposited. According to this manufacturing method, the stress concentration generated in the piezoelectric material layer at the boundary portion of the film formation region can be reduced, and damage to the piezoelectric material layer can be prevented.

  In the method for manufacturing a piezoelectric actuator of the present invention, the plurality of thin film layers may have an insulating layer, and in the step of forming the thin film layer, particles of insulating material and a carrier gas are supplied from the film forming nozzle. An insulating layer that insulates between the substrate having conductivity and the drive electrode may be formed by injecting an aerosol containing the substrate onto the substrate. According to this manufacturing method, the stress concentration generated in the insulating layer at the boundary portion of the film formation region can be reduced, and the insulating layer can be prevented from being damaged.

  According to the second aspect of the present invention, a plurality of pressure chambers arranged along a plane, a flow path unit having a plurality of injection nozzles respectively communicating with the plurality of pressure chambers, and the plurality of pressure chambers Is disposed on one surface of the flow path unit so as to cover the substrate, and has a deformable portion that can be deformed facing the pressure chamber and a restraint portion joined to the flow path unit, and is disposed on the substrate. A liquid comprising a piezoelectric material layer, and a piezoelectric actuator comprising a plurality of thin film layers including a drive electrode disposed so that at least a part of the piezoelectric material layer overlaps the deformable portion on one surface of the piezoelectric material layer A method for manufacturing a droplet ejecting apparatus, comprising: forming the plurality of thin film layers on the substrate; and attaching the flow path unit to the substrate, wherein the forming the thin film layer comprises: At least one thin film layer of the plurality of thin film layers is positioned on a plurality of regions divided adjacent to each other on the substrate, and a boundary portion between the adjacent regions is positioned outside the deformable portion. As described above, in the droplet ejecting apparatus, the aerosol including the particles forming the at least one thin film layer and the carrier gas is ejected from the deposition nozzle to each region while the deposition nozzle is relatively moved. A manufacturing method is provided.

  According to this method for manufacturing a droplet ejecting apparatus, at least one thin film layer of a piezoelectric actuator has a boundary portion between a plurality of regions, that is, a region where a drive electrode and a deformable portion of a substrate overlap, that is, a piezoelectric material by a drive electrode. An electric field is directly applied to the layer and the substrate is positioned outside the region where the substrate is greatly deformed. For this reason, even when a sudden change in film thickness occurs in the thin film layer at the boundary portion of the film formation region, the stress concentration generated in that portion is reduced and damage to the thin film layer is prevented.

  In the method for manufacturing a liquid droplet ejecting apparatus of the present invention, a slit for ejecting aerosol may be formed in the film forming nozzle, and the area of the aerosol ejected on the substrate covers at least one pressure chamber. It may have a large size. By using a slit having such a size, it is possible to form a film so that the boundary part of the film formation region is outside the active part.

  In the method for manufacturing a droplet ejecting apparatus of the present invention, any deformable portion can be formed in a plurality of divided areas.

  In the method of manufacturing a droplet ejecting apparatus according to the aspect of the invention, in the step of forming the thin film layer, the plurality of regions are arranged such that the boundary portion overlaps the restraining portion when viewed from a direction orthogonal to the substrate. The film forming nozzle can be moved for each. According to this manufacturing method, the boundary portion of the region where the thin film layer is formed by the relative movement of the deposition nozzle with respect to the substrate overlaps with the restraining portion of the substrate and does not overlap with the deformable portion. Even when a sudden change in film thickness occurs in the thin film layer at the boundary portion of the film region, the stress concentration generated in that portion is reduced.

  In the method for manufacturing a droplet ejecting apparatus of the present invention, the substrate may have a row of deformable portions in which the deformable portions are arranged in a predetermined direction, and in the step of forming the thin film layer, The film forming nozzle may be moved at a time in the predetermined direction with respect to the substrate to form a film on the entire region overlapping the row of the deformable portions when viewed from the direction orthogonal to the substrate. . According to this manufacturing method, the boundary portion of the film formation region of the thin film layer does not exist in the region overlapping the deformable portion, and the stress concentration in that portion is reduced. In this manufacturing method, a method of forming a thin film layer on an area overlapping with a row of deformable portions is performed by moving the film forming nozzle only once, and a film forming nozzle for one film forming area. And a method of moving particles a plurality of times and depositing particles on the film formation region.

  In the method for manufacturing a droplet ejecting apparatus of the present invention, in the step of forming the thin film layer, an aerosol containing particles of piezoelectric material and a carrier gas is ejected from the film forming nozzle onto the substrate. A piezoelectric material layer can be deposited. According to this manufacturing method, the stress concentration generated in the piezoelectric material layer at the boundary portion of the film formation region can be reduced, and damage to the piezoelectric material layer can be prevented.

  In the method for manufacturing a droplet ejecting apparatus of the present invention, the plurality of thin film layers may have an insulating layer, and in the step of forming the thin film layer, particles of insulating material and a carrier gas are formed from the film forming nozzle. An insulating layer that insulates between the conductive substrate and the drive electrode can be formed by spraying an aerosol containing According to this manufacturing method, the stress concentration generated in the insulating layer at the boundary portion of the film formation region can be reduced, and the insulating layer can be prevented from being damaged.

  According to the third aspect of the present invention, there is provided a piezoelectric actuator, a substrate having a plurality of deformable portions and a restraining portion for partitioning the deformable portion, a piezoelectric material layer disposed on the substrate, and the substrate A plurality of thin film layers including a drive electrode disposed so that at least a part of the piezoelectric material layer overlaps the deformable portion, and at least one thin film layer of the plurality of thin film layers includes: There is provided a piezoelectric actuator including a plurality of regions adjacent to each other, and a boundary portion between the regions is located outside the deformable portion.

  According to this piezoelectric actuator, at least one thin film layer has a boundary portion between a plurality of regions formed by relative movement of the film formation nozzle with respect to the substrate, a region where the drive electrode and the deformable portion of the substrate overlap, that is, The electric field is directly applied to the piezoelectric material layer by the drive electrode, and the substrate is positioned outside the region where the substrate is largely deformed. For this reason, even when a sudden change in film thickness occurs in the thin film layer at the boundary portion of the film formation region, the stress concentration generated in that portion is reduced and damage to the thin film layer is prevented.

  In the piezoelectric actuator of the present invention, at least one thin film layer may be the piezoelectric material layer.

  In the piezoelectric actuator according to the aspect of the invention, the thin film layer may be positioned on a plurality of regions divided adjacent to each other on the substrate, and a boundary portion between the adjacent regions may be located outside the deformable portion. In addition, an aerosol containing particles forming at least one thin film layer and a carrier gas may be jetted from the film forming nozzle to each region while moving the film forming nozzle relative to each region.

  According to the fourth aspect of the present invention, the liquid droplet ejecting apparatus has a plurality of pressure chambers arranged along a plane, and a flow path having a plurality of ejection nozzles respectively communicating with the plurality of pressure chambers. A substrate having a unit, a deformable portion that is disposed on one surface of the flow path unit so as to cover the plurality of pressure chambers, can be deformed facing the pressure chamber, and a restraining portion joined to the flow path unit. And a piezoelectric actuator having a piezoelectric material layer disposed on the substrate, and a plurality of thin film layers including a driving electrode disposed on one surface of the piezoelectric material layer so as to overlap the deformable portion, At least one thin film layer of the plurality of thin film layers of the piezoelectric actuator includes a plurality of regions adjacent to each other, and a droplet ejecting unit in which boundaries between these regions are located outside the deformable portion Location is provided.

  According to this droplet ejecting apparatus, the boundary between a plurality of regions formed by relative movement of at least one thin film layer of the piezoelectric actuator with respect to the substrate of the film forming nozzle is formed between the drive electrode and the deformable portion of the substrate. The overlapping region, ie, the region where the electric field is directly applied to the piezoelectric material layer by the drive electrode and the substrate is greatly deformed, is located outside. For this reason, even when a sudden change in film thickness occurs in the thin film layer at the boundary portion of the film formation region, the stress concentration generated in that portion is reduced and damage to the thin film layer is prevented.

  In the liquid droplet ejecting apparatus of the present invention, at least one thin film layer may be the piezoelectric material layer.

  In the liquid droplet ejecting apparatus according to the aspect of the invention, the thin film layer may be positioned on a plurality of regions divided adjacent to each other on the substrate, and a boundary portion between the adjacent regions may be located outside the deformable portion. As described above, the aerosol containing the particles forming the at least one thin film layer and the carrier gas may be sprayed from the deposition nozzle to each region while the deposition nozzle is relatively moved.

  In the liquid droplet ejecting apparatus of the present invention, the liquid droplet ejecting apparatus may be an ink jet printer.

    Next, an embodiment of the present invention will be described. The present embodiment is an example in which the present invention is applied to a serial type ink jet head that records an image or the like by ejecting ink onto a recording sheet while moving in one direction.

  First, the configuration of an ink jet printer provided with a serial ink jet head will be briefly described. As shown in FIG. 1, an inkjet printer 100 includes a carriage 4 that can move in the left-right direction in FIG. 1, and a serial-type inkjet head that is provided on the carriage 4 and ejects ink droplets onto a recording sheet 7. 1 (droplet ejecting device), a transport roller 5 for feeding the recording paper 7 forward in FIG. The ink jet printer 100 moves the ink jet head 1 integrally in the left and right direction (scanning direction) by the carriage 4 and then moves the ink jet nozzle 20 (see FIGS. 2 to 5) formed on the lower surface of the ink jet head 1 to the recording paper 7. On the other hand, desired characters and images are recorded on the recording paper 7 by ejecting ink.

  Next, the inkjet head 1 will be described with reference to FIGS. The inkjet head 1 is disposed on the upper surface of the flow path unit 2 in which an ink flow path including the ejection nozzle 20 and the pressure chamber 14 is formed, and applies ejection pressure to the ink in the pressure chamber 14. The piezoelectric actuator 3 is provided.

  First, the flow path unit 2 will be described. As shown in FIGS. 4 and 5, the flow path unit 2 includes a cavity plate 10, a base plate 11, a manifold plate 12, and a nozzle plate 13, and these four plates 10 to 13 are joined in a stacked state. Yes. Among these, the cavity plate 10, the base plate 11 and the manifold plate 12 are stainless steel plates, and ink flow paths such as a manifold 17 and a pressure chamber 14 described later can be easily etched in these three plates 10-12. It can be formed. The nozzle plate 13 is formed of, for example, a polymer synthetic resin material such as polyimide, and is bonded to the lower surface of the manifold plate 12. Or this nozzle plate 13 may be formed with metal materials, such as stainless steel, similarly to the three plates 10-12.

  As shown in FIGS. 2 to 5, among the four plates 10 to 13, the cavity plate 10 located at the uppermost position has holes through which a plurality of pressure chambers 14 arranged along a plane penetrate the plate 10. The plurality of pressure chambers 14 are respectively covered by a diaphragm 30 and a base plate 11 described later from above and below. The plurality of pressure chambers 14 are arranged in four rows in the paper feeding direction (vertical direction in FIG. 2). Furthermore, each pressure chamber 14 is formed in a substantially elliptical shape that is long in the scanning direction (left-right direction in FIG. 2) in plan view. In the present invention, “plan view” means viewing from a direction orthogonal to the diaphragm (substrate) 30.

  As shown in FIG. 3, communication holes 15 and 16 are formed at positions where the base plate 11 overlaps both ends of the pressure chamber 14 in a plan view. In this example, each of the communication holes 15 and 16 has a radius of about 0.05 mm. Further, the manifold plate 12 has four manifolds 17 extending in the paper feeding direction (vertical direction in FIG. 2) so as to overlap with the communication hole 15 side portions of the pressure chambers 14 arranged in the paper feeding direction in plan view. Is formed. These four manifolds 17 communicate with an ink supply port 18 (see FIG. 2) formed in a vibration plate 30 described later, and ink is supplied from an ink tank (not shown) to the manifold 17 through the ink supply port 18. The Furthermore, a plurality of communication holes 19 that are continuous with the plurality of communication holes 16 are also formed at positions where the manifold plate 12 overlaps the ends of the plurality of pressure chambers 14 opposite to the manifold 17 in plan view.

  Further, a plurality of injection nozzles 20 are formed at positions where the nozzle plate 13 overlaps the plurality of communication holes 19 in plan view. As shown in FIG. 2, the plurality of injection nozzles 20 overlap with the end portions of the plurality of pressure chambers 14 arranged in four rows on the side opposite to the manifold 17, and in areas not overlapping with the four manifolds 17. Four nozzle rows 21a, 21b, 21c, and 21d are arranged in the paper feed direction (up and down direction in FIG. 2) at regular intervals and aligned in the scanning direction. These four nozzle rows 21a to 21d are each composed of the same number of jet nozzles 20, and the intervals (pitch P) of the jet nozzles 20 in the arrangement direction are all equal. Further, the four nozzle rows 21a to 21d are sequentially shifted to the downstream side in the paper feed direction (downward in FIG. 2) by P / 4. Accordingly, it is possible to form a plurality of dots arranged on the recording paper 7 at intervals of P / 4 in the paper feeding direction by the four nozzle rows 21a to 21d.

  As shown in FIG. 2, the plurality of injection nozzles 20 and the plurality of pressure chambers 14 corresponding to the plurality of injection nozzles 20 are arranged in the paper feed direction (first arrangement direction) as a result. At the same time, they are also arranged in a direction (second arrangement direction) intersecting with the paper feed direction at an angle θ, and arranged in a matrix along these two directions. However, the number of arrangements (10) of the injection nozzles 20 and the pressure chambers 14 in the first arrangement direction is larger than the number of arrangements (4) in the second arrangement direction, and the arrangement interval is small (arrangement density). Is high). That is, the first arrangement direction corresponds to the direction in which fine dot rows are formed on the recording paper 7.

  As shown in FIG. 4, the manifold 17 communicates with the pressure chamber 14 through the communication hole 15, and the pressure chamber 14 communicates with the injection nozzle 20 through the communication holes 16 and 19. As described above, a plurality of individual ink flow paths 25 extending from the manifold 17 to the ejection nozzle 20 through the pressure chamber 14 are formed in the flow path unit 2.

  Next, the piezoelectric actuator 3 will be described. As shown in FIGS. 2 to 5, the piezoelectric actuator 3 includes a metal diaphragm 30 (substrate) disposed on the upper surface of the flow path unit 2 and a plurality of pressure chambers 14 on the upper surface of the diaphragm 30. And a plurality of individual electrodes 32 (drive electrodes) formed on the upper surface of the piezoelectric material layer 31 so as to correspond to the plurality of pressure chambers 14, respectively. The piezoelectric material layer 31 and the individual electrode 32 are both thin film layers (thin film layers) having a thickness of about several μm to several tens of μm. As shown in FIG. 3, the width of each individual electrode 32 (the length in the paper feeding direction in FIG. 3) may be about 0.16 mm.

  The diaphragm 30 is a conductive plate made of a substantially rectangular metal material in plan view, and is made of, for example, an iron-based alloy such as stainless steel, a copper-based alloy, a nickel-based alloy, or a titanium-based alloy. . The diaphragm 30 is disposed on the upper surface of the cavity plate 10 so as to cover the plurality of pressure chambers 14, and is joined to the cavity plate 10. The portion of the diaphragm 30 that faces the pressure chamber 14 is a deformable portion 30a that can be bent and deformed in the vertical direction, while the portion of the diaphragm 30 that is joined to the cavity plate 10 is restrained from being deformed. It becomes the restraint part 30b. The diaphragm 30 is always held at the ground potential, and is a common electrode that acts on the piezoelectric material layer 31 between the individual electrode 32 and the diaphragm 30 so as to face the plurality of individual electrodes 32 and in the thickness direction. Doubles as

  On the upper surface of the vibration plate 30, a piezoelectric material layer 31 mainly composed of lead zirconate titanate (PZT), which is a solid solution and is a ferroelectric substance, is formed of lead titanate and lead zirconate. The piezoelectric material layer 31 is continuously formed across the plurality of pressure chambers 14. The piezoelectric material layer 31 is formed by an aerosol deposition method (AD method) in which an aerosol composed of very fine particles and a carrier gas is sprayed on the substrate to deposit the particles. The film forming process of the piezoelectric material layer 31 by this AD method will be described in detail later.

  On the upper surface of the piezoelectric material layer 31, a plurality of individual electrodes 32 having a substantially elliptical planar shape that is slightly smaller than the pressure chamber 14 are formed. These individual electrodes 32 are each formed at a position overlapping the central portion of the corresponding pressure chamber 14 in plan view. The individual electrode 32 is made of a conductive material such as gold, copper, silver, palladium, platinum, or titanium. Further, a plurality of contact portions 35 are drawn out from the left end portions of the plurality of individual electrodes 32 in FIG. The plurality of contact portions 35 are joined to contacts of a flexible wiring member (not shown) such as a flexible printed circuit (FPC), and the plurality of contact portions 35 are connected to the wiring portions 35. It is electrically connected to a driver IC (not shown) that selectively supplies a driving voltage to the plurality of individual electrodes 32 via a member. A region 31b of the piezoelectric material layer 31 that overlaps the individual electrode 32 becomes a region that is deformed by a drive voltage as described later, and this region 31b is referred to as an “active portion”. FIG. 3 shows the dimensions (length 0.6 mm, width 0.25 mm) of the pressure chamber 14 of the ink jet head used in this example, and dimensions (length 0.5 mm, width) of the active portion 31 b and the individual electrode 32. An example of 0.16 mm) was shown.

  Next, the operation of the piezoelectric actuator 3 during ink ejection will be described. When a driving voltage is selectively applied to the plurality of individual electrodes 32 from the driver IC, the individual electrodes 32 above the piezoelectric material layer 31 to which the driving voltage is applied and the piezoelectric material layer 31 held at the ground potential are below. The potential of the diaphragm 30 as the common electrode on the side becomes different, and an electric field in the thickness direction is generated in the piezoelectric material layer 31 sandwiched between the individual electrode 32 and the diaphragm 30. Here, when the polarization direction of the piezoelectric material layer 31 is the same as the direction of the electric field, the piezoelectric material layer 31 extends in the thickness direction that is the polarization direction and contracts in the horizontal direction. As the piezoelectric material layer 31 contracts and deforms, the diaphragm 30 bends so as to protrude toward the pressure chamber 14, so that the volume in the pressure chamber 14 decreases and pressure is applied to the ink in the pressure chamber 14. The ink droplets are ejected from the ejection nozzle 20 that is applied and communicates with the pressure chamber 14.

  Next, a method for manufacturing the inkjet head 1 will be described. FIG. 6 schematically shows the manufacturing process of the inkjet head 1. First, as shown in FIG. 6A, the four plates 10 to 13 constituting the flow path unit 2 and the diaphragm 30 of the piezoelectric actuator 3 are joined by bonding, metal diffusion bonding, or the like (providing a substrate). Step).

  Next, the piezoelectric actuator 3 is manufactured by the following steps. As shown in FIG. 6B, the piezoelectric material layer 31 is formed on the upper surface of the vibration plate 30 (the surface opposite to the joint surface with the flow path unit 2) by the AD method. That is, an aerosol containing ultrafine particles of piezoelectric material and a carrier gas is jetted toward the diaphragm 30 to collide at high speed, and particles are densely deposited on the upper surface of the diaphragm 30 to form a thin film piezoelectric material layer 31. Form. Thereafter, as shown in FIG. 6C, a plurality of individual electrodes 32 and a plurality of contact portions 35 are formed on the upper surface of the piezoelectric material layer 31 by screen printing, sputtering, vapor deposition, or the like.

  Further, the process of forming the piezoelectric material layer 31 by the AD method will be described in more detail. FIG. 7 is a schematic configuration diagram of a film forming apparatus 50 for the piezoelectric material layer 31. The film forming apparatus 50 is connected to an aerosol generator 60 via an aerosol supply pipe 64 and a film forming nozzle 52 disposed in the film forming chamber 51 and a film forming chamber 51. A stage 53 for moving the diaphragm 30 in a predetermined direction is provided.

  The aerosol generator 60 generates an aerosol Z that is a mixture of an ultrafine particle (for example, a particle size of 1 μm or less) piezoelectric material M and a carrier gas. The aerosol generator 60 includes an aerosol chamber 61 that can accommodate material particles M therein, and a vibration device 62 that is attached to the aerosol chamber 61 and vibrates the aerosol chamber 61. A gas cylinder G for introducing a carrier gas is connected to the aerosol chamber 61 via an introduction pipe 63. As the carrier gas, dry air, nitrogen gas, argon gas, oxygen gas, helium gas or the like is used. A film forming nozzle 52 and a stage 53 are installed in the film forming chamber 51, and the film forming chamber 51 is connected to a vacuum pump P through an exhaust pipe 54. A rectangular slit 55 (see FIG. 8) that is long in one direction and that opens toward the vibration plate 30 on the stage 53 is provided at the tip of the film forming nozzle 52. Further, the stage 53 moves the diaphragm 30 in the width direction of the slit 55 (horizontal direction in FIG. 7).

  Then, the film forming apparatus 50 reduces the pressure in the film forming chamber 51 with a vacuum pump and sprays the aerosol generated by the aerosol generator from the slit 55 of the film forming nozzle 52 toward the upper surface of the diaphragm 30. At the same time, the diaphragm 30 on the stage 53 is moved relative to the film forming nozzle 52 to form the piezoelectric material layer 31 in a predetermined region of the diaphragm 30 (step of forming a thin film layer).

  Further, the relative movement of the vibration plate 30 and the film forming nozzle 52 when the piezoelectric material layer 31 is formed will be described in detail. 8A and 8B show the positional relationship between the diaphragm 30 and the film forming nozzle 52 during film formation. As described above, the vibration plate 30 actually moves with respect to the film formation nozzle 52 together with the stage 53. However, in the following description, the film formation nozzle 52 moves with respect to the vibration plate 30 for convenience. It shall be.

  As shown in FIG. 8A, the film forming nozzle 52 has a width direction of the slit 55 with respect to a region on the upper surface of the vibration plate 30 (direction perpendicular to the longitudinal direction of the slit 55: the front-rear direction in FIG. 8). The aerosol is sprayed onto the vibration plate 30 while moving to the piezoelectric material layer 31 to form the piezoelectric material layer 31 in this region. Further, when it is necessary to form the piezoelectric material layer 31 in another region other than this region, as shown in FIG. The aerosol is sprayed while moving in the width direction of the slit 55 to form the piezoelectric material layer 31 in this region. The injection may be stopped until the film formation nozzle 52 reaches above the other region, and the injection may be resumed when the injection start position in another region is reached. FIG. 8C shows a region (hereinafter referred to as “injection region”) 31a on the substrate covered with the aerosol ejected from the film forming nozzle 52 in a stopped state. In this example, the ejection region 31 a is rectangular, has a width of about 0.4 mm, and has a length that completely accommodates the two active portions 31 b aligned in the scanning direction of the piezoelectric material layer 31. The spray region 31a may use a film forming nozzle 52 that is long enough to cover one active part 31b or three or more active parts 31b. In this way, the piezoelectric material layer 31 is formed over a wide area on the upper surface of the vibration plate 30 by spraying the aerosol while moving the film forming nozzle 52 relative to each of the plurality of regions on the upper surface of the vibration plate 30. It becomes possible to do.

  When the piezoelectric material layer 31 is formed in each of a plurality of regions on the upper surface of the vibration plate 30, the moving direction of the film forming nozzle with respect to the plurality of regions is the same as shown in FIGS. 8A and 8B. In FIG. 8, it may be from front to rear. Alternatively, the deposition nozzle is moved from the front to the rear with respect to a certain area so that aerosol can be continuously sprayed to a plurality of areas, and the deposition nozzle from the rear to the front with respect to the next adjacent area. The movement direction of the film forming nozzle may be switched alternately.

  As shown in FIG. 8, when the film-formation nozzle 52 for injecting aerosol is moved in one direction with respect to the vibration plate 30 to form the band-shaped piezoelectric material layer 31, the film of the band-shaped piezoelectric material layer 31 is formed. The thickness is substantially uniform in the longitudinal direction, that is, the moving direction of the film forming nozzle 52 (front-rear direction in FIG. 8), and there is almost no film thickness distribution. On the other hand, with respect to the width direction of the band-shaped piezoelectric material layer 31 (direction perpendicular to the moving direction of the film forming nozzle 52: the left-right direction in FIG. 8), the flow velocity distribution of the aerosol ejected from the slit 55 is not uniform. The piezoelectric material layer 31 tends to have a film thickness distribution.

  And in the film-forming process of the piezoelectric material layer 31 of this embodiment, as shown by the broken line arrow in FIG. The piezoelectric material layer 31 is formed on the upper surface of the diaphragm 30 by moving in the direction in which the deformable portions 30 a of the diaphragm 30 correspond to the plurality of pressure chambers 14. More specifically, a region A1 of the diaphragm 30 that overlaps two pressure chamber rows on one side in the scanning direction (left side in FIG. 9A) and 2 on the other side in the scanning direction (right side in FIG. 9A). The film formation nozzle 52 is moved in the direction in which the pressure chambers 14 are arranged with respect to each of the two regions A1 and A2 adjacent to each other in the scanning direction in the region A2 overlapping the pressure chamber row. That is, the film forming nozzle 52 is moved in the arrangement direction of the pressure chambers 14 with respect to the region A1, and the piezoelectric material layer is formed all over the region A1 overlapping the two left pressure chamber rows (rows of the deformable portions 30a). 31 is formed. Subsequently, the film forming nozzle 52 is moved in the arrangement direction of the pressure chambers 14 with respect to the region A2, and the piezoelectric material layer 31 is formed all at once in the entire region A2 overlapping with the two pressure chamber rows on the right side. The piezoelectric material layer 31 may be formed on the regions A1 and A2 by moving the film forming nozzle 52 only once for each film forming region. It may be carried out by moving the particles a plurality of times and depositing the particles by overlapping them.

  As described above, the piezoelectric material layer 31 formed by moving the film forming nozzle 52 in the arrangement direction of the pressure chambers 14 is parallel to the moving direction of the film forming nozzle 52 as shown in FIG. With respect to the paper feed direction, which is the direction, the film thickness is substantially uniform. On the other hand, as shown in FIG. 9C, a certain film thickness distribution is generated in the piezoelectric material layer 31 in the scanning direction of the inkjet head 1, which is a direction orthogonal to the moving direction of the film forming nozzle 52. When the piezoelectric material layer 31 is formed in each of the two regions A1 and A2 of the diaphragm 30, the moving speed of the film forming nozzle 52 (that is, the moving speed of the stage 53) and the amount of aerosol sprayed from the slit 55 If the film forming conditions such as the same are the same, the film thickness distributions in these two regions A1 and A2 are substantially equal.

  Therefore, as shown in FIG. 9C, depending on the film thickness distribution of the two regions A1 and A2, the film thickness of the piezoelectric material layer 31 is abrupt at the boundary portion B (joint portion) between these regions A1 and A2. May change. As described above, when the piezoelectric material layer 31 has a portion where the film thickness rapidly changes, a predetermined voltage is applied to the individual electrode 32 at the time of polarization processing after the film formation or when the ejection pressure is applied to the ink in the pressure chamber 14. When an electric field is applied to the piezoelectric material layer 31 and the piezoelectric material layer 31 is deformed, stress concentration occurs in the portion, and the piezoelectric material layer 31 may be damaged.

  However, as shown in FIG. 9A, in this embodiment, the boundary portion B (boundary portion) between the regions A1 and A2 where the piezoelectric material layer 31 is formed is the pressure chamber 14 (deformable). The film forming nozzle 52 is moved in the paper feeding direction with respect to the vibration plate 30 so as to overlap with the restraining portion 30b of the vibration plate 30 joined to the flow path unit 2 outside the portion 30a) and the individual electrode 32. That is, the boundary portion B between the two regions A1 and A2 is located between the two central pressure chamber rows, and the boundary portion B does not overlap the pressure chamber 14 (deformable portion 30a).

  Therefore, even when the film thickness of the piezoelectric material layer 31 changes abruptly at the boundary portion B between the regions A1 and A2, the boundary portion B can be obtained when an electric field is applied to the piezoelectric material layer 31 by the individual electrode 32. Since it does not overlap with the deformable portion 30a to be deformed, the stress concentration generated in the piezoelectric material layer 31 at the boundary portion B is reduced. Therefore, damage to the piezoelectric material layer 31 is prevented, and the reliability of the piezoelectric actuator 3 is increased.

  Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals and description thereof is omitted as appropriate.

<Modification 1>
When a voltage is applied to the individual electrode 32 and an electric field in the thickness direction acts on the piezoelectric material layer 31, the deformation of the portion of the piezoelectric material layer 31 that overlaps the pressure chamber 14 is the largest. Therefore, as shown in FIG. 10, the boundary portion B between the regions A1 and A2 where the piezoelectric material layer 31 is formed by the relative movement of the film forming nozzle 52 should be at least outside the individual electrodes 32 in plan view. What is necessary is just to overlap with the pressure chamber 14 (deformable part 30a) somewhat. Also in this modified embodiment 1, the effect of reducing the stress concentration generated in the boundary portion B between the regions A1 and A2 can be obtained.

<Modification 2>
As shown in FIGS. 11 and 12, the individual electrode 32 </ b> B of the piezoelectric actuator 3 </ b> B may be formed in an annular shape along the periphery of the pressure chamber 14 in a region overlapping the pressure chamber 14 in plan view. The piezoelectric actuator 3B causes the diaphragm 30 to bend and deform by the expansion and contraction of the piezoelectric material layer 31 in the portion overlapping the peripheral edge of the pressure chamber 14 when a drive voltage is applied to the individual electrode 32B, and the pressure is reduced. Pressure is applied to the ink in the chamber 14. When manufacturing such a piezoelectric actuator 3B, the boundary between a plurality of regions formed by relative movement of the film forming nozzle 52 with respect to the diaphragm 30 is positioned outside the pressure chamber 14. The membrane nozzle 52 is moved.

  Further, although the edge of the individual electrode 32B and the edge of the pressure chamber 14 may coincide with each other, in order to increase the driving efficiency by deforming the piezoelectric material layer 31 in the region immediately inside the edge of the pressure chamber 14 more greatly. 11 and 12, the individual electrode 32 </ b> B may be formed so as to extend from the edge of the pressure chamber 14 to a further outer region. In this case, the boundary between the plurality of regions where the piezoelectric material layer 31 is formed by the relative movement of the film formation nozzle 52 with respect to the vibration plate 30 is at least the pressure chamber 14 (deformable portion 30a) of the individual electrode 32B. ) (Ie, the edge of the pressure chamber 14), and may overlap with a portion of the individual electrode 32 B positioned outside the pressure chamber 14.

<Modification 3>
As shown in FIG. 13A, the plurality of pressure chambers 14 includes two paper feeding directions (first arrangement direction) and a direction inclined by an angle θ with respect to the paper feeding direction (second arrangement direction). They are arranged in a matrix along the direction. Therefore, the film formation nozzle 52 is moved relative to the vibration plate 30 in the second arrangement direction, and the pressure chambers 14 (deformable portions) of the vibration plate 30 arranged in the second arrangement direction are arranged. The piezoelectric material layer 31 may be formed at a time in a region overlapping with 30a). In this case, the piezoelectric material layer 31 has a film thickness distribution as shown in FIG. 13B, and the film thickness may change abruptly at the boundary between the film formation regions A3 and A4. By moving the film formation nozzle 52 so that the boundary between the film formation regions A3 and A4 is located between the pressure chamber rows, the stress concentration generated at the boundary portion can be reduced.

<Modification 4>
In the embodiment, the piezoelectric material layer 31 that is one of the thin film layers constituting the piezoelectric actuator 3 is formed by the AD method. However, a thin film layer other than the piezoelectric material layer 31 may be formed by the AD method. Good. For example, as shown in FIG. 14, the individual electrode 32 is disposed on the upper surface of the diaphragm 30 (the lower surface of the piezoelectric material layer 31), and the common electrode 34 is common to the plurality of individual electrodes on the upper surface of the piezoelectric material layer 31. The configuration of being opposed to each other has an advantage that wiring for supplying a driving voltage to the individual electrode 32 can be easily routed on the upper surface of the diaphragm 30. However, in this configuration, when the diaphragm 30 is a conductive metal plate, it is necessary to provide an insulating layer 36 between the diaphragm 30 and the individual electrode 32 to insulate them. The insulating layer 36 needs to have a certain degree of rigidity, like the diaphragm 30, in order to reliably transmit the deformation of the piezoelectric material layer 31 to the ink in the pressure chamber 14, for example, alumina, zirconia, etc. It is made of an insulating ceramic material.

  Here, the insulating layer 36 made of a ceramic material such as alumina can be formed by the AD method in the same manner as the film forming step of the piezoelectric material layer 31 described above. That is, the aerosol containing the fine particles of the ceramic material forming the insulating layer 36 and the carrier gas is transferred to the slit 55 of the film forming nozzle 52 while moving the film forming nozzle 52 having the slit 55 in a predetermined direction with respect to the vibration plate 30. Then, the insulating layer 36 is formed by spraying on the diaphragm 30 (see FIG. 8). At that time, similarly to the above-described embodiment, the boundary between the plurality of regions formed by the relative movement of the film forming nozzle 52 with respect to the diaphragm 30 overlaps the pressure chamber 14 (deformable portion 30a) of the individual electrode 32. The film forming nozzle 52 may be moved so as to be positioned outside the outermost surface.

  In this modified embodiment 4, both the insulating layer 36 and the piezoelectric material layer 31 may be formed by the above-described film forming process using the AD method, or the piezoelectric material layer 31 may be formed by a method other than the AD method. A film may be formed.

  The above-described embodiment and its modified form are examples in which the present invention is applied to a piezoelectric actuator for an ink jet head, but the form to which the present invention can be applied is not limited thereto. That is, as long as it is configured to drive the target by deforming the deformable portion of the substrate, it can also be applied to a piezoelectric actuator used outside the field of inkjet heads. The liquid droplet ejecting apparatus is not limited to an ink jet printer, and can be applied to an apparatus for ejecting liquid droplets used in various fields such as medical treatment and analysis.

1 is a schematic configuration diagram of an inkjet printer according to an embodiment of the present invention. It is a top view of an inkjet head. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is the VV sectional view taken on the line of FIG. It is explanatory drawing of the manufacturing process of an inkjet head. It is a schematic block diagram of the film-forming apparatus. (A) is a figure which shows the positional relationship of the diaphragm and film-forming nozzle in the area | region with a diaphragm at the time of film-forming of a piezoelectric material layer, (b) is a figure of the diaphragm at the time of film-forming of a piezoelectric material layer It is a figure which shows the positional relationship of the diaphragm and film-forming nozzle in another area | region, (c) is a top view which shows the relationship between an injection area | region and an active part. (A) is a plan view of the inkjet head, (b) is a side view of the piezoelectric actuator when viewed from the scanning direction, and (c) is a side view of the piezoelectric actuator when viewed from the paper feed direction. . It is a top view of the inkjet head which concerns on the modification 1. FIG. 6 is a partially enlarged view of an inkjet head according to a modified embodiment 2. FIG. It is the XII-XII sectional view taken on the line of FIG. (A) is a top view of the inkjet head which concerns on the modification 3, (b) is the side view seen from the scanning direction of the piezoelectric actuator which concerns on the modification 3. FIG. FIG. 6 is a cross-sectional view corresponding to FIG. 4 of an inkjet head according to a modified embodiment 4;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet head 2 Flow path unit 3, 3B Piezoelectric actuator 14 Pressure chamber 20 Injection nozzle 30a Deformation allowance part 30b Restraint part 30 Diaphragm 31 Piezoelectric material layer 32, 32B Individual electrode 36 Insulating layer 52 Film formation nozzle

Claims (21)

A substrate having a plurality of deformable portions and a restraining portion that partitions the deformable portions;
A method of manufacturing a piezoelectric actuator comprising: a piezoelectric material layer disposed on the substrate; and a plurality of thin film layers including drive electrodes disposed so as to overlap the deformable portion,
Providing the substrate;
Forming the plurality of thin film layers on the substrate,
The step of forming the thin film layer includes the step of forming at least one thin film layer of the plurality of thin film layers on a plurality of regions partitioned adjacent to each other on the substrate and a boundary portion between the adjacent regions. The aerosol containing the particles forming the at least one thin film layer and the carrier gas is sprayed from the film forming nozzle to each region while moving the film forming nozzle relative to each other so as to be positioned outside the deformable part. A method of manufacturing a piezoelectric actuator including forming.   The piezoelectric actuator according to claim 1, wherein a slit for injecting aerosol is formed in the film forming nozzle, and the slit has a size such that an area of the aerosol to be injected on the substrate covers at least one pressure chamber. Method.   The method for manufacturing a piezoelectric actuator according to claim 1, wherein any deformable portion is formed in a plurality of divided regions.   In the step of forming the thin film layer, the film forming nozzle is moved with respect to each of the plurality of regions so that the boundary portion overlaps the restraining portion when viewed from a direction orthogonal to the substrate. Item 2. A method for manufacturing a piezoelectric actuator according to Item 1.   The substrate has a row of deformable portions in which a plurality of deformable portions are arranged in a predetermined direction, and in the step of forming the thin film layer, the film forming nozzle is connected to the substrate in the predetermined direction. 5. The method of manufacturing a piezoelectric actuator according to claim 4, wherein the film is formed at a time on the entire region overlapping the row of the deformable portions when viewed from a direction orthogonal to the substrate.   2. The piezoelectric material layer according to claim 1, wherein in the step of forming the thin film layer, an aerosol containing piezoelectric material particles and a carrier gas is sprayed from the film formation nozzle onto the substrate. A method for manufacturing a piezoelectric actuator.   The plurality of thin film layers have an insulating layer, and in the step of forming the thin film layer, an aerosol containing particles of an insulating material and a carrier gas is sprayed from the film formation nozzle onto the substrate, thereby providing conductivity. The method for manufacturing a piezoelectric actuator according to claim 1, wherein an insulating layer is formed to insulate between the substrate having the electrode and the drive electrode. A plurality of pressure chambers arranged along a plane, a flow path unit having a plurality of injection nozzles respectively communicating with the plurality of pressure chambers, and one surface of the flow path unit so as to cover the plurality of pressure chambers And a substrate having a deformable portion deformable facing the pressure chamber and a restraining portion joined to the flow path unit, a piezoelectric material layer disposed on the substrate, and the piezoelectric material layer In one aspect, a method for manufacturing a droplet ejecting apparatus including a piezoelectric actuator including a plurality of thin film layers including a drive electrode disposed so that at least a part thereof overlaps the deformable portion,
Forming the plurality of thin film layers on the substrate;
Attaching the flow path unit to the substrate,
The step of forming the thin film layer includes the step of forming at least one thin film layer of the plurality of thin film layers on a plurality of regions partitioned adjacent to each other on the substrate and a boundary portion between the adjacent regions. The aerosol containing the particles forming the at least one thin film layer and the carrier gas is sprayed from the film forming nozzle to each region while moving the film forming nozzle relative to each other so as to be positioned outside the deformable part. A method of manufacturing a droplet ejecting apparatus including forming.   The droplet ejecting apparatus according to claim 8, wherein a slit for injecting aerosol is formed in the film forming nozzle, and the area of the aerosol injecting the slit onto the substrate covers at least one pressure chamber. Manufacturing method.   The method for manufacturing a droplet ejecting apparatus according to claim 8, wherein any deformable portion is formed in a plurality of divided regions.   In the step of forming the thin film layer, the film forming nozzle is moved with respect to each of the plurality of regions so that the boundary portion overlaps the restraining portion when viewed from a direction orthogonal to the substrate. Item 9. A method for manufacturing a droplet ejection device according to Item 8.   The substrate has a row of deformable portions in which a plurality of deformable portions are arranged in a predetermined direction, and in the step of forming the thin film layer, the film forming nozzle is connected to the substrate in the predetermined direction. The method of manufacturing a droplet ejecting apparatus according to claim 11, wherein film formation is performed at once on the entire region overlapping with the row of the deformable portions when viewed from a direction orthogonal to the substrate.   The method for manufacturing a droplet ejecting apparatus according to claim 8, wherein the at least one thin film layer is the piezoelectric material layer.   The method for manufacturing a droplet ejecting apparatus according to claim 8, wherein the at least one thin film layer is an insulating layer. A piezoelectric actuator,
A substrate having a plurality of deformable portions and a restraining portion that partitions the deformable portions;
A piezoelectric material layer disposed on the substrate, and a plurality of thin film layers including a drive electrode disposed on at least part of the piezoelectric material layer so as to overlap the deformable portion on one surface of the piezoelectric material layer;
The at least one thin film layer among the plurality of thin film layers includes a plurality of regions adjacent to each other, and a boundary portion between these regions is located outside the deformable portion.   The piezoelectric actuator according to claim 15, wherein at least one thin film layer is the piezoelectric material layer.   The thin film layer includes the at least one thin film on a plurality of regions divided adjacent to each other on the substrate and so that boundary portions of the adjacent regions are located outside the deformable portion. The piezoelectric actuator according to claim 15, wherein the piezoelectric actuator is formed by spraying an aerosol containing particles forming a layer and a carrier gas while moving the film forming nozzle relative to each region from the film forming nozzle. A droplet ejection device,
A plurality of pressure chambers arranged along a plane, and a flow path unit having a plurality of injection nozzles respectively communicating with the plurality of pressure chambers;
A substrate having a deformable portion that is arranged on one surface of the flow path unit so as to cover the plurality of pressure chambers and that can be deformed facing the pressure chamber, and a restraining portion joined to the flow path unit; A piezoelectric actuator having a piezoelectric material layer disposed on a substrate and a plurality of thin film layers including a drive electrode disposed on one surface of the piezoelectric material layer so as to overlap the deformable portion;
At least one thin film layer of the plurality of thin film layers of the piezoelectric actuator includes a plurality of regions adjacent to each other, and a boundary part of these regions is located outside the deformable portion. .   The droplet ejecting apparatus according to claim 18, wherein at least one thin film layer is the piezoelectric material layer.   The thin film layer includes the at least one thin film on a plurality of regions divided adjacent to each other on the substrate and so that boundary portions of the adjacent regions are located outside the deformable portion. The droplet ejecting apparatus according to claim 18, wherein the droplet ejecting apparatus is formed by ejecting an aerosol containing particles forming a layer and a carrier gas from the deposition nozzle to each region while relatively moving the deposition nozzle.   The liquid droplet ejecting apparatus according to claim 18, wherein the liquid droplet ejecting apparatus is an ink jet printer.

Images