JP2007088449A - Composite material film, piezoelectric actuator, and process for manufacturing inkjet head, and piezoelectric actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric actuator in which adhesiveness can be improved between overlapping layers, and to provide a process for manufacturing an inkjet head. <P>SOLUTION: A lower electrode 3 is formed by spraying aerosol Z containing conductive material particles M1 and ceramics particles M2 toward a diaphragm 2 and sticking these particles thereto. When ceramics particles M2 having a high hardness are admixed to the conductive material particles M1 and sprayed, the ceramics particles M2 adhere to the surface of the diaphragm 2 while eating into the diaphragm by impact of collision thus enhancing adhesion between the diaphragm 2 and lower electrode 3. Furthermore, adhesiveness of the lower electrode 3 and a piezoelectric layer 4 is improved because the lower electrode 3 contains oxide ceramics of the same properties as those of the oxide ceramics composing the piezoelectric layer 4, thereby retarding stripping due to difference of thermal expansion coefficient. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite material film, a piezoelectric actuator, an inkjet head manufacturing method, and a piezoelectric actuator.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2001-54946) discloses an example of a piezoelectric actuator used for an inkjet head or the like. This piezoelectric actuator includes a substrate (vibration plate) provided so as to close an opening of a pressure chamber communicating with a nozzle opening in a flow path forming body, and a lower electrode, a piezoelectric layer, and an upper electrode are laminated on the substrate. It is. When an electric field is applied between the lower electrode and the upper electrode, the substrate is bent as the piezoelectric layer is deformed, and the ink in the pressure chamber is pressurized and ejected from the nozzle opening.

As a method for manufacturing such a piezoelectric actuator, there is a method called an aerosol deposition method (AD method) disclosed in Patent Document 1. This is because piezoelectric particles such as lead zirconate titanate (PZT) in which fine particles of a piezoelectric material are dispersed in a gas (aerosol) are jetted toward the substrate surface, and the fine particles collide and deposit on the substrate. Is formed.
JP 2001-54946 A

  By the way, it is necessary to anneal the piezoelectric film formed by the AD method as described above in order to obtain the piezoelectric characteristics necessary to sufficiently bend the substrate.

  However, if the annealing process is performed at a high temperature exceeding 600 ° C., for example, elements contained in the substrate may diffuse into the piezoelectric film and deteriorate the piezoelectric characteristics. In particular, in recent years, there is a desire to use stainless steel, which is inexpensive and excellent in workability, as a substrate. However, since stainless steel contains metal elements such as Fe and Cr that easily diffuse in the piezoelectric film, this problem is remarkable. Become. Therefore, in order to improve the piezoelectric characteristics, an insulating oxide layer such as alumina is provided as a diffusion preventing layer between the substrate and the piezoelectric film. In such a case, a lower electrode is provided between the diffusion prevention layer and the piezoelectric layer in order to apply an electric field to the piezoelectric layer.

  However, when many layers are laminated in this way, stress is generated at the interface of the overlapping layers due to the difference in the thermal expansion coefficient of the material constituting each layer during the high-temperature annealing treatment, and peeling easily occurs. End up.

  In the manufacture of an inkjet head, the ink flow path forming body is made of a metal material so that a fine ink flow path can be easily formed, and the piezoelectric actuator substrate to be joined to the ink flow path forming body In order to avoid adverse effects such as warpage during thermocompression bonding to the ink flow path forming body, it is preferable that the ink flow path forming body is made of a material having a coefficient of thermal expansion close to that of the ink flow path forming body, that is, the same kind of metal. However, when a metal substrate is used in this way, the metal element contained in the substrate is likely to diffuse into the piezoelectric layer. For this reason, it is necessary to provide an anti-diffusion layer between the substrate and the piezoelectric layer. When it is necessary to stack a large number of layers in this way, it is not possible to ensure the adhesion of each layer with the conventional method. It was not always easy.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composite material film, a piezoelectric actuator, a method for manufacturing an ink jet head, and a piezoelectric actuator that can improve adhesion between mutually overlapping layers. There is.

Means for Solving the Problems and Effects of the Invention

According to a first aspect of the present invention, there is provided a method for producing a composite material film, comprising: a step of mixing conductive material particles and ceramic particles to obtain a mixture; and a step of spraying an aerosol containing the mixture onto a substrate. Is done.
By doing so, a composite material film including conductive material particles and ceramic particles can be easily manufactured.

  According to the second aspect of the present invention, a first electrode layer forming step of forming one electrode layer by spraying an aerosol containing conductive material particles and ceramic particles onto a substrate and attaching these particles. A piezoelectric layer forming step of spraying an aerosol containing particles of piezoelectric material onto the one electrode layer and attaching the particles of the piezoelectric material, and an annealing process for annealing the piezoelectric layer There is provided a method of manufacturing a piezoelectric actuator including a step and a second electrode layer forming step of forming another electrode layer paired with the one electrode layer on the piezoelectric layer.

  There are no particular limitations on the ceramic particles, and any ceramic particles may be used as long as they have a hardness sufficient to cause biting upon collision with the substrate and are chemically stable. Specifically, oxide ceramics such as alumina, silica, zirconia, and mullite can be used alone or in admixture of two or more.

  The conductive material particle is not particularly limited as long as it is a general electrode material. For example, Ag, Pt, Au, Co, Ti, Ni, Pd, etc. may be used alone or in combination of two or more. Can be used. In particular, Pt, Au, or the like that hardly diffuses into other layers is preferable. This is to ensure conductivity as an electrode and to avoid a decrease in piezoelectric characteristics of the piezoelectric layer due to diffusion.

  The substrate and the piezoelectric material are not particularly limited as long as they can be used normally as a material for the piezoelectric actuator. For example, the substrate material is stainless steel (SUS430, SUS304, etc.), 42A alloy, alumina, zirconia, titanium. As the piezoelectric material, lead zirconate titanate (PZT), barium titanate, lead titanate, lead magnesium niobate (PMN), lead nickel niobate (PNN), etc. are used alone or in combination of two or more. Can be used.

  In this case, ceramic particles having a hardness higher than that of conductive material particles such as metal are mixed and sprayed onto the substrate, and the ceramic particles adhere to the surface of the substrate due to impact of collision. Adhesion with the electrode layer can be improved. In addition, since one electrode layer contains oxide ceramics having the same quality and high affinity as the piezoelectric material (mostly oxide ceramics) constituting the piezoelectric layer laminated on the surface thereof, Adhesion between the electrode layer and the piezoelectric layer is also improved, and peeling due to a difference in thermal expansion coefficient is less likely to occur. Thereby, the adhesiveness between each layer which comprises a piezoelectric actuator can be made favorable. In addition, by mixing ceramic particles, the amount of relatively expensive conductive material particles used can be relatively reduced, so that the manufacturing cost can be reduced.

  In the method for manufacturing a piezoelectric actuator of the present invention, before the first electrode layer forming step, an aerosol containing ceramic particles that regulate diffusion of elements contained in the substrate into the piezoelectric layer is sprayed on the substrate. It may include forming an anti-diffusion layer by adhering. In this way, if relatively hard ceramic particles are used as the particles constituting the diffusion prevention layer, the ceramic particles adhere to the substrate surface by biting into the substrate due to the impact of the collision, and thus strongly adhere to the substrate. And since one electrode layer formed on this diffusion prevention layer contains the same quality and high affinity ceramic particles as the diffusion prevention layer, the adhesiveness with the diffusion prevention layer is good and due to the difference in thermal expansion coefficient. Peeling does not occur easily. In this way, even when many layers are stacked, adhesion between the respective layers can be ensured and peeling can be avoided. The ceramic particles constituting one electrode layer and the diffusion preventing layer may be the same or different types, but if different types are used, the upper layer is used. What is necessary is just to make it hardness so high that it attaches later. This is to increase the adhesion by causing the ceramic particles to bite into the surface of the adhesion layer.

  In the method for manufacturing a piezoelectric actuator of the present invention, the diffusion prevention layer may be formed only in a portion where the first electrode layer is formed. In this case, since the diffusion preventing layer is formed only in the portion where the electrode layer is formed, the element contained in the substrate diffuses to the piezoelectric layer in the portion where the diffusion preventing layer is not formed, and the piezoelectric performance is deteriorated. On the other hand, since the portion where the diffusion preventing layer is formed does not diffuse, the piezoelectric performance can be maintained and crosstalk can be suppressed.

  In the method for manufacturing a piezoelectric actuator of the present invention, after the first electrode layer forming step, an aerosol containing ceramic particles that restrict diffusion of elements contained in the one electrode layer into the piezoelectric layer is used as the one electrode. It may include forming a diffusion barrier layer by spraying onto the layer and depositing. In this case, since the diffusion preventing layer is composed of ceramic particles having the same quality and high affinity as the ceramic particles contained in one electrode layer, the adhesion with the one electrode layer is good and peeling due to the difference in thermal expansion coefficient. Is unlikely to occur. That is, it is possible to ensure adhesion between the layers and avoid peeling. Also in the present invention, the ceramic particles constituting one electrode layer and the diffusion prevention layer may be the same or different types, but when using different types, The upper layer (those to be attached later) may have a higher hardness. This is to increase the adhesion by causing the ceramic particles to bite into the surface of the adhesion layer.

  In the method for manufacturing a piezoelectric actuator of the present invention, a mixing ratio of the conductive material particles in the one electrode layer forming step may be 4 wt% to 50 wt%. According to such a blending ratio, it is possible to further ensure both of ensuring the conductivity as an electrode by the conductive material particles and ensuring the adhesion by biting the ceramic particles into the lower layer.

  According to the third aspect of the present invention, the step of spraying aerosol by an aerosol deposition method while changing the component or composition constituting the aerosol to form a multilayer film, the step of annealing the multilayer film, Forming a piezoelectric actuator on the multilayer film.

  In this case, since the multilayer film is continuously formed while changing the components of the aerosol and the composition thereof, the multilayer film can be formed more efficiently than the method of forming each layer in a separate process. Therefore, the manufacturing process of the piezoelectric actuator is improved.

  In the method for manufacturing a piezoelectric actuator of the present invention, the step of forming the multilayer film includes forming a first electrode layer by spraying an aerosol containing conductive material particles and ceramic particles at a predetermined ratio, and forming only the ceramic particles. Spraying an aerosol containing the second layer to form a second electrode layer, and spraying an aerosol containing conductive material particles and ceramic particles at a predetermined ratio to form the second electrode layer. In this case, the first electrode layer, the second layer, and the second electrode layer can be continuously formed while changing the ratio of the conductive material particles and the ceramic particles.

  In the method for manufacturing a piezoelectric actuator of the present invention, the ceramic particles for forming the second layer may be piezoelectric ceramic particles.

  In the method for manufacturing a piezoelectric actuator of the present invention, the ceramic particles for forming the second electrode layer may be alumina or zirconia, and the conductive material particles may be Ag or Au particles.

  According to the fourth aspect of the present invention, an inkjet head manufactured by joining the piezoelectric actuator manufactured by the manufacturing method according to the second aspect of the present invention and an ink flow path forming body provided with an ink flow path. In the method, a metal substrate is used as the substrate, and holes serving as the ink flow paths are formed in each of a plurality of metal plates made of the same kind of metal as the metal substrate, and the plurality of metal plates An ink flow path forming body forming step of forming the ink flow path forming body by laminating and bonding, and a bonding step of bonding the metal substrate to the upper surface of the ink flow path forming body A manufacturing method is provided.

  According to the fifth aspect of the present invention, the piezoelectric actuator manufactured by the manufacturing method in which the mixing ratio of the conductive material particles in the one electrode forming step is 4 wt% to 50 wt%, and the ink flow path Each of a plurality of metal plates made of the same kind of metal as the metal substrate, using a metal substrate as the substrate. Forming an ink channel forming body by forming a hole to be the ink channel and laminating and joining the plurality of metallic plates, and the ink channel forming body There is provided an ink jet head manufacturing method comprising a bonding step of bonding the metal substrate to an upper surface of the inkjet head.

  In these cases, even in an ink jet head having a fine ink flow path, adhesion between the layers constituting the piezoelectric actuator can be ensured.

  According to a sixth aspect of the present invention, a substrate, a first electrode layer formed on the substrate, a piezoelectric layer formed on the first electrode layer, and formed on the piezoelectric layer. And a second electrode layer, and the first electrode layer is provided with a piezoelectric actuator in which a conductive material is dispersed in ceramic particles.

  In this case, since the ceramic particles contained in the first electrode layer are adhered to the surface of the substrate while being adhered, the adhesion between the substrate and the first electrode layer is improved. In addition, since the first electrode layer includes oxide ceramics having the same quality and high affinity as the piezoelectric material constituting the piezoelectric layer laminated on the surface, the first electrode layer and the piezoelectric layer Adhesion is also good, and peeling due to the difference in thermal expansion coefficient hardly occurs. Therefore, the adhesion between the layers constituting the piezoelectric actuator can be improved. Furthermore, by mixing ceramic particles as a component of the first electrode layer, the amount of relatively expensive conductive material particles used can be relatively reduced, leading to a reduction in manufacturing costs.

  In the piezoelectric actuator of the present invention, the ceramic particles may be alumina or zirconia particles, and the conductive material particles may be Ag or Au particles.

<First Embodiment>
Hereinafter, a first embodiment embodying the present invention will be described in detail with reference to FIGS. 1 to 4B. FIG. 1 shows an inkjet head 10 according to this embodiment. The inkjet head 10 includes a flow path unit 11 (ink flow path forming body) having a plurality of pressure chambers 16 in which ink 20 is accommodated, and an actuator joined on the flow path unit 11 so as to close the pressure chambers 16. Plate 1 (piezoelectric actuator).

  The flow path unit 11 has a flat plate shape as a whole, and the nozzle plate 12, the manifold plate 13, the flow path plate 14, and the pressure chamber plate 15 (each metal plate) are sequentially stacked, and the plates 12, 13 are stacked. , 14 and 15 are joined to each other with an epoxy thermosetting adhesive.

  The nozzle plate 12 is formed of a polyimide-based synthetic resin material, and a plurality of ink discharge nozzles 19 for ejecting the ink 20 are formed in an array therein. The manifold plate 13 is formed of, for example, stainless steel (SUS430), and a plurality of nozzle channels 18 connected to the ink discharge nozzles 19 are provided therein. Similarly, the flow path plate 14 is formed of stainless steel (SUS430), and a plurality of pressure flow paths 17 communicating with the nozzle flow paths 18 are provided therein. The pressure chamber plate 15 is also made of stainless steel (SUS430), and a plurality of pressure chambers 16 communicating with the pressure channel 17 are provided therein. The pressure chamber 16 is connected to an ink tank through a flow path plate 14, a manifold flow path (not shown) provided in the manifold plate 13, and a common ink chamber. Thus, an ink flow path F is formed from the common ink chamber connected to the ink tank to the ink discharge nozzle 19 through the manifold flow path, the pressure chamber 16, the pressure flow path 17, and the nozzle flow path 18. Yes.

  The actuator plate 1 stacked on the flow path unit 11 includes a vibration plate 2 (substrate and metal substrate) constituting a part of the wall surface of the pressure chamber 16, and a lower electrode 3 (on the vibration plate 2). One electrode layer), a piezoelectric layer 4 laminated on the lower electrode 3, and an upper electrode 5 (another electrode layer) provided on the piezoelectric layer 4.

  The diaphragm 2 is formed in a rectangular shape using, for example, stainless steel (SUS430), and is joined to the upper surface of the flow path unit 11 by thermocompression bonding so as to cover the entire upper surface of the flow path unit 11. The diaphragm 2 is made of the same metal material as the manifold plate 13, the channel plate 14, and the pressure chamber plate 15 constituting the channel unit 11. 11 can be prevented from warping. When the diaphragm 2 is formed of a conductive material, it functions as a common electrode together with the lower electrode 3.

  The lower electrode 3 is formed at a position corresponding to the opening 16 </ b> A of the pressure chamber 16 on the surface opposite to the surface in contact with the flow path unit 11 in the diaphragm 2. The lower electrode 3 is provided in a region corresponding to the opening 16A of each pressure chamber 16 on the surface of the diaphragm 2, and is connected to the ground of a drive circuit IC (not shown). The lower electrode 3 is formed by an aerosol deposition method, and prevents diffusion of the conductive material particles M1 that ensure the conductivity as an electrode and the elements contained in the diaphragm 2 into the piezoelectric layer 4. And a ceramic particle M2 (see also FIG. 4B) that ensures adhesion to the piezoelectric layer 4 and also serves as a diffusion preventing layer.

  The piezoelectric layer 4 is made of a ferroelectric piezoelectric ceramic material such as lead zirconate titanate (PZT), and the entire surface of the diaphragm 2 is sandwiched between the lower electrode 3 and the diaphragm 2. Are laminated with a uniform thickness. The piezoelectric layer 4 is formed by an aerosol deposition method, and is subjected to polarization processing so as to be polarized in the thickness direction.

  A plurality of upper electrodes 5 are provided on the surface of the piezoelectric layer 4 (the surface opposite to the side in close contact with the diaphragm 2). The upper electrode 5 is provided in a region corresponding to the opening 16A of each pressure chamber 16, and is connected to the drive circuit IC and used as a drive electrode.

  When performing printing, when a predetermined drive signal is issued from the drive circuit IC, the potential of the upper electrode 5 is set higher than that of the lower electrode 3, and an electric field is applied in the polarization direction (thickness direction) of the piezoelectric layer 4. Is done. Then, the piezoelectric layer 4 expands in the thickness direction and contracts in the surface direction. Thereby, the area | region corresponding to opening of the pressure chamber 16 in the piezoelectric layer 4 and the diaphragm 2 (namely, actuator plate 1) deform | transforms locally so that it may become convex to the pressure chamber 16 side (unimorph deformation). For this reason, the volume of the pressure chamber 16 decreases, the pressure of the ink 20 increases, and the ink 20 is ejected from the ink discharge nozzle 19. Thereafter, when the upper electrode 5 is returned to the same potential as that of the lower electrode 3, the piezoelectric layer 4 and the diaphragm 2 are restored to the original shape, and the volume of the pressure chamber 16 is restored to the original volume. Suction from the manifold flow path communicating with.

  The lower electrode 3 and the piezoelectric layer 4 are formed by an aerosol deposition method. FIG. 2 shows a schematic diagram of the film forming apparatus 30. The film forming apparatus 30 includes an aerosol generator 31 that forms an aerosol Z by dispersing material particles M in a carrier gas, and a film forming chamber 35 that causes the aerosol Z to be ejected from an ejection nozzle 37 and adhered to a substrate. ing.

  The aerosol generator 31 includes an aerosol chamber 32 in which the material particles M can be accommodated, and a vibration device 33 that is attached to the aerosol chamber 32 and vibrates the aerosol chamber 32. A gas cylinder B for introducing a carrier gas is connected to the aerosol chamber 32 via an introduction pipe 34. The distal end of the introduction tube 34 is located near the bottom surface in the aerosol chamber 32 and is buried in the material particles M. As the carrier gas, for example, an inert gas such as helium, argon, or nitrogen, air, oxygen, or the like can be used.

  The film forming chamber 35 is provided with a stage 36 for attaching a substrate on which a piezoelectric layer is to be formed, and an injection nozzle 37 provided below the stage 36. The injection nozzle 37 is connected to the aerosol chamber 32 via an aerosol supply pipe 38, and the aerosol Z in the aerosol chamber 32 is supplied to the injection nozzle 37 through the aerosol supply pipe 38. Further, a vacuum pump P is connected to the film forming chamber 35 via a powder recovery device 39, and the inside thereof can be decompressed.

  Next, a method for manufacturing the actuator plate 1 for the ink jet head 10 using the film forming apparatus 30 will be described.

  First, as shown in FIG. 3A, the diaphragm 2 made of stainless steel is overlapped with the upper surface of the pressure chamber plate 15 in the flow path unit 11 and joined by thermocompression bonding. The chamber 16 is closed.

  Next, as shown in FIG. 3B, the lower electrode 3 also serving as a diffusion preventing layer is formed on the diaphragm 2 (first electrode layer forming step). The lower electrode 3 is formed by an aerosol deposition method (AD method). First, masking (not shown) is performed on the surface of the vibration plate 2 outside the opening 16 </ b> A of the pressure chamber 16 by a well-known method and set on the stage 36 of the film forming apparatus 30. Next, a mixture of conductive material particles M <b> 1 and ceramic particles M <b> 2 is introduced as material particles M into the aerosol chamber 32.

  And carrier gas is introduce | transduced from the gas cylinder B, and the material particle M is made to soar by the gas pressure. At the same time, the aerosol chamber 32 is vibrated by the vibration device 33, whereby the material particles M and the carrier gas are mixed to generate the aerosol Z. Then, by depressurizing the inside of the film forming chamber 35 with the vacuum pump P, the aerosol Z in the aerosol chamber 32 is accelerated from the injection nozzle 37 while being accelerated at a high speed by the differential pressure between the aerosol chamber 32 and the film forming chamber 35. Erupt. The material particles M contained in the ejected aerosol Z collide with the diaphragm 2 and are deposited to form a layer of the lower electrode 3.

  At this time, if the material particles M are composed of relatively soft metal particles or the like, the particles M that have collided with the diaphragm 2 cannot sink into the plate surface, and a sufficient anchor layer is not formed. And the adhesion between the diaphragm 2 and the diaphragm 2 are weakened. As shown in FIG. 4A as a conceptual diagram, there is a clear boundary between the particles M1 and the particles 2a constituting the diaphragm 2. However, in this embodiment, among the material particles M, the ceramic particles M2 having an appropriate hardness collide with the surface of the diaphragm 2 at a high speed, and take a fine structure in which these are pulverized and are appropriately recessed into the diaphragm 2. . As shown in FIG. 4B, the particles M 1 and M 2 are embedded in the particles 2 a of the diaphragm 2 even at the boundary between the lower electrode 3 and the diaphragm 2. As a result, a layer having a dense grain interface and high adhesion can be produced.

  Subsequently, the masking is removed, and as shown in FIG. 3C, the piezoelectric layer 4 is formed by the aerosol deposition method (AD method) (piezoelectric layer forming step). First, the diaphragm 2 after the formation of the lower electrode 3 is set on the stage 36 of the film forming apparatus 30. Next, particles of piezoelectric material are introduced as material particles M into the aerosol chamber 32.

  Then, an aerosol Z is generated and sprayed on the diaphragm 2 in the same manner as the first electrode layer forming step described above. The material particles M contained in the ejected aerosol Z collide with the vibration plate 2 and deposit to form the piezoelectric layer 4. At this time, since the lower electrode 3 contains ceramic particles M2 having the same quality and good affinity as the oxide ceramic that is the piezoelectric material constituting the piezoelectric layer 4, the adhesion between the lower electrode 3 and the piezoelectric layer 4 is increased. Will also be good.

  Subsequently, in order to obtain necessary piezoelectric characteristics, the formed piezoelectric layer 4 is annealed. At this time, metal elements such as Fe and Cr contained in the stainless steel diaphragm 2 diffuse into the piezoelectric layer 4. However, since the lower electrode 3 also serving as a diffusion prevention layer is provided in a region corresponding to the opening 16A of the pressure chamber 16, that is, a region bent by applying a voltage, the metal element of the diaphragm 2 is piezoelectric. It does not diffuse into layer 4. Therefore, the piezoelectric characteristics can be maintained in the region deflected by the application of voltage. Further, since the lower electrode 3 contains the ceramic particles M2, the diaphragm 2 and the lower electrode 3 and the lower electrode 3 and the piezoelectric layer 4 are in close contact with each other. Can do.

  Next, as shown in FIG. 3D, the upper electrode 5 and a plurality of lead portions (not shown) connected to each upper electrode 5 are formed on the upper surface of the piezoelectric layer 4. In order to form the upper electrode 5 and the lead portion, for example, a conductor film may be formed over the entire area of the piezoelectric layer 4 and then formed into a predetermined pattern using a photolithography etching method. Alternatively, the piezoelectric layer may be formed. The upper surface of 4 may be formed directly by screen printing.

  Thereafter, an electric field stronger than that in the normal ink ejection operation is applied between the upper electrode 5 and the lower electrode 3 to polarize the piezoelectric layer 4 between both electrodes in the thickness direction (polarization treatment). Thus, the actuator plate 1 is completed.

  As described above, according to the present embodiment, the lower electrode 3 is formed by spraying the aerosol Z containing the conductive material particles M1 and the ceramic particles M2 on the diaphragm 2 and attaching these particles. In this way, if the ceramic particles M2 having high hardness are mixed and sprayed on the conductive material particles M1, the ceramic particles M2 adhere to the surface of the diaphragm 2 due to the impact of the collision. Adhesiveness with the electrode 3 can be improved. Furthermore, since the lower electrode 3 contains an oxide ceramic that is the same quality as the oxide ceramic that is the material constituting the piezoelectric layer 4, the adhesion between the lower electrode 3 and the piezoelectric layer 4 is improved, and thermal expansion is achieved. Peeling due to the difference in rate is less likely to occur. In this manner, the adhesion between the layers constituting the actuator plate 1 can be improved. In addition, by mixing the ceramic particles M2, the amount of the relatively expensive conductive material particles M1 used can be relatively reduced, so that the manufacturing cost can be reduced.

  Further, ceramic particles M2 having a diffusion preventing effect are used. Thereby, since the lower electrode 3 can serve as a diffusion preventing layer, a separate step of forming a diffusion preventing layer is not required, and the manufacturing process can be simplified.

Second Embodiment
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 5A to 6B. The difference of this embodiment from the first embodiment is that a diffusion prevention layer 46 is provided between the diaphragm 42 and the lower electrode 43 in the actuator plate 41. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  The actuator plate 41 of this embodiment shown in FIG. 6B is for an ink jet head as in the first embodiment, and includes a diaphragm 42 that constitutes a part of the wall surface of the pressure chamber 16. On the vibration plate 42, a diffusion preventing layer 46, a lower electrode 43 laminated on the diffusion preventing layer 46, a piezoelectric layer 44 laminated on the lower electrode 43, and a piezoelectric layer 44 are provided. The upper electrode 45 is provided.

  In order to manufacture the actuator plate 41 of the present embodiment, first, the diaphragm 42 is overlapped and joined to the upper surface of the pressure chamber plate 15 in the same manner as in the first embodiment, and each pressure is applied by the diaphragm 42. The chamber 16 is closed (FIG. 5A).

  Next, in the diffusion preventing layer forming step, the diffusion preventing layer 46 is formed on the vibration plate 42 in a region corresponding to the opening 16 </ b> A of the pressure chamber 16. (FIG. 5B). The diffusion prevention layer 46 is formed by an aerosol deposition method (AD method) using the film forming apparatus 30 similar to that of the first embodiment. As the material particles M, oxide ceramic particles (for example, alumina) having a diffusion preventing function for preventing diffusion of elements contained in the vibration plate 42 into the piezoelectric layer 44 are used. At this time, since the ceramic particles have a relatively high hardness, the ceramic particles adhere to the surface of the diaphragm 42 by being impacted by a collision. Thereby, the vibration plate 42 and the diffusion preventing layer 46 are strongly adhered.

  Next, as shown in FIGS. 5C and 5D, an aerosol deposition method (AD method) is used on the surface of the vibration plate 42 on which the diffusion prevention layer 46 is formed using the film forming apparatus 30 similar to the first embodiment. ) To form the lower electrode 43 and the piezoelectric layer 44. At this time, since the diffusion prevention layer 46 is composed of oxide ceramics having the same quality and good affinity as the oxide ceramics (ceramic particles M2) included in the lower electrode 3, the diffusion prevention layer 46 and the lower electrode 43 are formed. Adhesion with the resin is also good. Further, as described in the first embodiment, the lower electrode 43 includes ceramic particles M2 having the same quality and good affinity as the oxide ceramic that is the piezoelectric material constituting the piezoelectric layer 44. The adhesion between the piezoelectric layer 44 and the piezoelectric layer 44 is also improved.

  Subsequently, as shown in FIG. 6A, the formed piezoelectric layer 44 is annealed. At this time, since the diffusion prevention layer 46 is provided in a region corresponding to the opening 16A of the pressure chamber 16 (that is, a region bent by applying a voltage), the piezoelectric element of the metal element contained in the vibration plate 42 is provided. Diffusion into layer 44 is prevented. Therefore, as in the first embodiment, the piezoelectric characteristics can be maintained in the region bent by applying a voltage. Further, since the diaphragm 42 and the diffusion preventing layer 46, the diffusion preventing layer 46 and the lower electrode 43, and the lower electrode 43 and the piezoelectric layer 44 are in close contact with each other, peeling due to thermal shock can be avoided.

  Thereafter, the upper electrode 45 is formed as in the first embodiment (FIG. 6B), and the polarization process is performed to complete the actuator plate 41.

  As described above, according to the present embodiment, even when many layers are laminated with the diffusion prevention layer 46, the lower electrode 43, and the piezoelectric layer 44, adhesion between the respective layers can be ensured and peeling can be avoided. .

  Hereinafter, the present invention will be described in more detail with reference to examples.

<Example 1-1>
1. Formation of Lower Electrode and Piezoelectric Layer (1) Lower Electrode The film forming apparatus is basically the same as the apparatus shown in FIG. 2 used in the above embodiment, but in this example, as shown in FIG. A device further comprising two aerosol generators 41 and a cylinder was used. Similarly to the first aerosol generator 31, the second aerosol generator 41 is also provided with an aerosol chamber 42 in which the material particles M can be accommodated, and an additive that is attached to the aerosol chamber 42 and vibrates the aerosol chamber 42. A vibration device 43 is provided, and a gas cylinder B for introducing a carrier gas is connected to the aerosol chamber 42 via an introduction pipe 34. First, a substrate in which an alumina layer having a thickness of 1 to 3 μm is formed on the surface of a stainless steel (SUS430) plate, an alumina powder having an average particle diameter of 0.3 to 1 μm and an Ag powder is mixed at a ratio of 99: 1. Was mixed in the first aerosol chamber 32 as the lower electrode material M. On the alumina layer of the substrate, nozzle opening 0.4 mm × 10 mm, film forming chamber pressure 200 Pa, aerosol chamber pressure 30000 Pa, carrier gas type He, gas flow rate 4.5 liter / min, nozzle-substrate distance 10-20 mm As a result, aerosol was sprayed from the first aerosol generator 31, and the lower electrode layer was formed by the AD method. The thickness of the lower electrode layer was approximately 1 to 2 μm as measured by a step using a surface roughness meter.
(2) Piezoelectric layer In order to form a piezoelectric layer, the nozzles 37 of the first aerosol generator 31 and the second aerosol generator 41 shown in FIG. On the lower electrode layer formed as described above, PZT powder with an average particle size of 0.3 to 1 μm accommodated in the second aerosol chamber 42 is converted into a second aerosol generator under the same conditions as in (1) above. By spraying from 41, a piezoelectric layer was formed by the AD method. The thickness of the piezoelectric layer was approximately 8 μm as measured by a step using a surface roughness meter.
(3) Annealing treatment Subsequently, the formed piezoelectric layer was subjected to an annealing treatment. A muffle furnace (FP100, manufactured by Yamato Kogyo Co., Ltd.) was heated to 850 ° C., and the substrate after forming the piezoelectric layer was put inside. After holding for a predetermined time, the substrate was taken out of the furnace and cooled to room temperature by natural cooling.
2. Test The film formation after the formation of the lower electrode layer and after the formation of the piezoelectric layer was visually observed. Further, the surface resistance of the lower electrode was measured by a resistance measuring instrument (digital multimeter CDM-170).

<Example 1-2>
The test was performed by forming the lower electrode and the piezoelectric layer in the same manner as in Example 1-1 except that the mixing ratio of the alumina powder and the Ag powder was set to 98: 2.

<Example 1-3>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 1-1 except that the mixing ratio of the alumina powder and the Ag powder was 96: 4.

<Example 1-4>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 1-1 except that the mixing ratio of alumina powder and Ag powder was 90:10.

<Example 1-5>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 1-1 except that the mixing ratio of the alumina powder and the Ag powder was set to 70:30.

<Example 1-6>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 1-1 except that the mixing ratio of the alumina powder and the Ag powder was 50:50.

<Example 2-1>
As the lower electrode material, a mixture of zirconia powder and Ag powder at a mixing ratio of 99: 1 was used. Other than that, the lower electrode and the piezoelectric layer were formed in the same manner as in Example 1-1, and the test was performed.

<Example 2-2>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 2-1, except that the mixing ratio of zirconia powder and Ag powder was 98: 2.

<Example 2-3>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 2-1, except that the mixing ratio of zirconia powder and Ag powder was 96: 4.

<Example 2-4>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 2-1, except that the mixing ratio of zirconia powder and Ag powder was 90:10.

<Example 2-5>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 2-1, except that the mixing ratio of the zirconia powder and the Ag powder was set to 70:30.

<Example 2-6>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 2-1, except that the mixing ratio of the zirconia powder and the Ag powder was 50:50.

<Example 3-1>
As the lower electrode material, a mixture of alumina powder and Au powder at a mixing ratio of 99: 1 was used. Other than that, the lower electrode and the piezoelectric layer were formed in the same manner as in Example 1-1, and the test was performed.

<Example 3-2>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 3-1, except that the mixing ratio of alumina powder and Au powder was 98: 2.

<Example 3-3>
The test was performed by forming the lower electrode and the piezoelectric layer in the same manner as in Example 3-1, except that the mixing ratio of the alumina powder and the Au powder was 96: 4.

<Example 3-4>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 3-1, except that the mixing ratio of alumina powder and Au powder was 90:10.

<Example 3-5>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 3-1, except that the mixing ratio of the alumina powder and the Au powder was set to 70:30.

<Example 3-6>
A test was performed by forming a lower electrode and a piezoelectric layer in the same manner as in Example 3-1, except that the mixing ratio of the alumina powder and the Au powder was 50:50.

<Comparative Example 1>
As the lower electrode material, Ag powder not mixed with alumina powder was used. Other than that, the lower electrode and the piezoelectric layer were formed in the same manner as in Example 1-1, and the test was performed.

<Comparative example 2>
An Ag thin film having a thickness of 0.5 μm was formed on the substrate by sputtering, and this was used as the lower electrode layer. Other than that, the lower electrode and the piezoelectric layer were formed in the same manner as in Example 1-1, and the test was performed.

<Comparative Example 3>
A TiAg thin film having a thickness of 0.5 μm was formed on the substrate by sputtering, and this was used as a lower electrode layer. Other than that, the lower electrode and the piezoelectric layer were formed in the same manner as in Example 1-1, and the test was performed.

[Results and discussion]
In Example 1-1 to 1-6 and Comparative Example 1, the mixing ratio of the alumina powder and the Ag powder, the observation result of the film formation state after the lower electrode film formation and the piezoelectric layer film formation, and the lower electrode formation Table 1 shows the measurement results of the surface electrical resistance after and after annealing.

  In addition, Examples 2-1 to 2-6 and Examples 3-1 to 3-6 are also shown in Table 2 and Table 3 in the same manner. In these embodiments, the upper electrode can be formed on the piezoelectric layer by annealing or the like after the annealing process to complete the piezoelectric actuator.

下部電極層の材料としてアルミナ粉末を混入していないＡｇ粉末を用いた場合（比較例１）においては、ＡＤ法によってＡｇ粉末が基板のアルミナ層に密着せず、成膜を行うことができなかった。また、スパッタリングにより下部電極層を形成した場合（比較例２、３）には、上部に圧電膜を成膜した際に、下部電極層と基板のアルミナ層との間で剥離を生じた。これは、圧電膜形成時の圧電粒子の衝突応力のためであると考えられ、このことから、下部電極層と基板との密着力が充分ではないことがわかる。

When Ag powder not mixed with alumina powder is used as the material of the lower electrode layer (Comparative Example 1), the Ag powder does not adhere to the alumina layer of the substrate by the AD method, and film formation cannot be performed. It was. In addition, when the lower electrode layer was formed by sputtering (Comparative Examples 2 and 3), peeling occurred between the lower electrode layer and the alumina layer of the substrate when the piezoelectric film was formed on the upper part. This is considered to be due to the impact stress of the piezoelectric particles during the formation of the piezoelectric film, and this shows that the adhesion between the lower electrode layer and the substrate is not sufficient.

  On the other hand, when a mixture of alumina powder and Ag powder was used as the material for the lower electrode layer (Examples 1-1 to 1-6), peeling occurred both during and after the formation of the lower electrode layer. It was not observed, and it was found that the substrate-lower electrode layer-piezoelectric layer was in close contact. Further, the surface electric resistance of the lower electrode layer is 0.6Ω or less when Ag powder is 2% by weight or more, and the conductivity as the electrode can be sufficiently secured when the mixing amount of the conductive material particles is about 2% by weight. I understood. In addition, after annealing of the piezoelectric layer, the surface electrical resistance did not change significantly when the Ag powder was 4 wt% or more, but the surface electrical resistance increased to 20 Ω or more when the Ag powder was 2 wt%. This is considered to be because the conductivity of the lower electrode layer was lowered because Ag diffused into the piezoelectric layer or the alumina layer of the substrate by the annealing treatment. Therefore, in consideration of diffusion due to the annealing treatment, it is preferable that the ratio of the conductive material particles be 4% by weight or more.

  Further, with respect to the ceramic particles, sufficient adhesion could be obtained at a mixing ratio of 50% or more. Considering the effect of reducing the manufacturing cost by relatively reducing the amount of the relatively expensive conductive material particles used, the mixing ratio of the ceramic particles is preferably at least 50% or more, and the conductivity as an electrode is high. It is preferable to increase as much as possible within a range not to be damaged.

  In addition, when the ceramic particles are changed to zirconia powder (Examples 2-1 to 2-6) and when the conductive material particles are changed to Au (Examples 3-1 to 3-6), the results are large. There was no difference. When a material having a large diffusion amount during annealing is used as the conductive material particles, it is preferable that the ratio of the conductive material particles be higher than that of Ag or Au. Although data is not shown in detail, for example, when Fe or Cr is used, it is considered that conductivity can be secured at about 10% by weight.

  The scope of the present invention is not limited by the above-described embodiments, and, for example, those described below are also included in the scope of the present invention. In addition, the scope of the present invention extends to an equivalent range.

  In each of the above embodiments, a stainless steel substrate is used as the diaphragms 2 and 42. However, the material of the substrate is not limited to the above embodiments, and a ceramic substrate such as an alumina substrate may be used. In this case, since there is no diffusion from the substrate during the annealing process, the diffusion preventing layer can be omitted.

  In each of the above embodiments, since the insulating ceramic powder is mixed in the lower electrodes 3 and 43, depending on the mixing ratio with the conductive material particles, the diffusion state of the conductive material particles, etc. It may be difficult to secure a pass. In order to avoid this problem, a conductive material layer may be further laminated on the layer made of ceramic particles and conductive material particles by sputtering, AD method or the like.

  In each of the above embodiments, the piezoelectric layers 4 and 44 are formed directly on the lower electrodes 3 and 43. However, if the metal constituting the conductive material particles is a material that is easily diffused by annealing, A diffusion preventing layer may be provided between the electrode layer and the piezoelectric layer.

  In the above examples, a mixture of alumina powder and Ag powder, alumina powder and Au powder, and zirconia powder and Ag powder was used as the material of the lower electrode. However, a mixture of PZT powder and Ag powder or PZT powder and Au powder was used. When the piezoelectric layer is formed on the lower electrode material, only PZT powder may be used as the material.

  In each of the above embodiments, the piezoelectric actuator has been described as an example of manufacturing. However, the present invention is not limited to this, and manufacturing of battery cells, manufacturing of electrolytic membranes used in fuel cells, application of functional coatings such as high-efficiency catalysts, medical The method of the present invention can also be used in the production of various composite material films such as artificial bones in the field.

It is sectional drawing of the inkjet head of 1st Embodiment. It is the schematic of the film-forming apparatus of 1st Embodiment. 3A is a cross-sectional view showing a state in which the diaphragm is joined to the ink flow path forming body in the manufacturing process of the actuator plate of the first embodiment, FIG. 3B is a cross-sectional view showing a state in which the lower electrode is formed, and FIG. Sectional drawing which shows a mode that the layer was formed, FIG. 3D is sectional drawing which shows a mode that the upper electrode was formed. 4A is a partially enlarged sectional view of the interface between the diaphragm and the lower electrode when ceramic particles are not mixed, and FIG. 4B is a partially enlarged sectional view of the interface between the diaphragm and the lower electrode when ceramic particles are mixed. is there. FIG. 5A is a cross-sectional view showing a state in which the diaphragm is joined to the ink flow path forming body in the manufacturing process of the actuator plate of the second embodiment, FIG. 5B is a cross-sectional view showing a state in which the diffusion prevention layer is formed, and FIG. FIG. 5D is a cross-sectional view showing a state in which a piezoelectric layer is formed. FIG. 6A is a cross-sectional view showing a state where an annealing process is performed in the manufacturing process of the actuator plate of the second embodiment, and FIG. 6B is a cross-sectional view showing a state where an upper electrode is formed. It is the schematic of the film-forming apparatus used in the Example.

Explanation of symbols

1 ... Actuator plate (piezoelectric actuator)
2, 42 ... Diaphragm (substrate, metal substrate)
3, 43 ... Lower electrode (one electrode layer)
4, 44 ... piezoelectric layers 5, 45 ... upper electrodes (other electrode layers)
10: Inkjet head 11: Channel unit (ink channel forming body)
12 ... Nozzle plate (metal plate)
13 ... Manifold plate (metal plate)
14 ... Channel plate (metal plate)
15 ... Pressure chamber plate (metal plate)
46 ... Diffusion prevention layer F ... Ink channel M ... Material particle M1 ... Conductive material particle M2 ... Ceramic particle Z ... Aerosol

Claims (15)

A step of mixing conductive material particles and ceramic particles to obtain a mixture;
Spraying an aerosol containing the mixture onto a substrate;
A method for producing a composite material film. A first electrode layer forming step of forming one electrode layer by spraying an aerosol containing conductive material particles and ceramic particles on a substrate and attaching these particles;
A piezoelectric layer forming step of forming a piezoelectric layer by spraying an aerosol containing particles of a piezoelectric material on the one electrode layer and attaching the particles of the piezoelectric material;
An annealing process for annealing the piezoelectric layer;
A second electrode layer forming step of forming another electrode layer paired with the one electrode layer on the piezoelectric layer;
A method for manufacturing a piezoelectric actuator including:   3. The method of manufacturing a piezoelectric actuator according to claim 2, wherein the ceramic particles are alumina or zirconia particles, and the conductive material particles are Ag or Au particles.   Before the first electrode layer forming step, an anti-diffusion layer is formed by spraying and adhering an aerosol containing ceramic particles that regulate the diffusion of elements contained in the substrate to the piezoelectric layer. The manufacturing method of the piezoelectric actuator of Claim 2 including this.   The method for manufacturing a piezoelectric actuator according to claim 4, wherein the diffusion prevention layer is formed only in a portion where the first electrode layer is formed.   After the first electrode layer forming step, by spraying and attaching an aerosol containing ceramic particles that regulates diffusion of elements contained in the one electrode layer into the piezoelectric layer, onto the one electrode layer The method for manufacturing a piezoelectric actuator according to claim 2, comprising forming a diffusion prevention layer.   3. The method of manufacturing a piezoelectric actuator according to claim 2, wherein, in the one electrode layer forming step, a mixing ratio of the conductive material particles is 4 wt% to 50 wt%. A process of forming a multilayer film by spraying an aerosol by an aerosol deposition method while changing components or compositions constituting the aerosol;
Annealing the multilayer film;
Forming an electrode on the multilayer film;
A method for manufacturing a piezoelectric actuator including:   The step of forming the multilayer film includes forming a first electrode layer by spraying conductive material particles and ceramic particles at a predetermined ratio, and spraying an aerosol containing only ceramic particles to form a second layer. The method for manufacturing a piezoelectric actuator according to claim 8, further comprising spraying conductive material particles and ceramic particles at a predetermined ratio to form the second electrode layer.   The method for manufacturing a piezoelectric actuator according to claim 9, wherein the ceramic particles for forming the second layer are piezoelectric ceramic particles.   10. The method of manufacturing a piezoelectric actuator according to claim 9, wherein the ceramic particles when forming the second electrode layer are alumina or zirconia, and the conductive material particles are Ag or Au particles. A method for manufacturing an ink jet head comprising a piezoelectric actuator manufactured by the manufacturing method according to claim 4 and an ink flow path forming body including an ink flow path.
Using a metal substrate as the substrate,
The ink flow path forming body is formed by forming a hole to be the ink flow path in each of a plurality of metal plates made of the same type of metal as the metal substrate, and laminating and bonding the plurality of metal plates. An ink flow path forming body forming step to be formed;
A bonding step of bonding the metal substrate to the upper surface of the ink flow path forming body;
A method for manufacturing an inkjet head comprising: A method for manufacturing an ink-jet head comprising joining a piezoelectric actuator manufactured by the manufacturing method according to claim 7 and an ink flow path forming body including an ink flow path,
Using a metal substrate as the substrate,
The ink flow path forming body is formed by forming a hole to be the ink flow path in each of a plurality of metal plates made of the same type of metal as the metal substrate, and laminating and bonding the plurality of metal plates. An ink flow path forming body forming step to be formed;
A bonding step of bonding the metal substrate to the upper surface of the ink flow path forming body;
A method for manufacturing an inkjet head comprising: A substrate,
A first electrode layer formed on the substrate;
A piezoelectric layer formed on the first electrode layer;
A second electrode layer formed on the piezoelectric layer;
A piezoelectric actuator in which a conductive material is dispersed in ceramic particles in the first electrode layer. 15. The piezoelectric actuator according to claim 14, wherein the ceramic particles are alumina or zirconia particles, and the conductive material particles are Ag or Au particles.

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