JP2005317952A - Piezoelectric actuator, ink-jet head and manufacturing method of them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To readily form a piezoelectric material layer on a part of a substrate surface area. <P>SOLUTION: A deposition allowable region A, that is developed to films by attaching the fine particles of the piezoelectric material in a carrier gas and a deposition inhibiting region B, that inhibits the development of films are provided by forming the pattern of a different hardness material layer 28 different from that of a substrate 26 on the substrate 26. If the carrier gas, containing the fine particles of the piezoelectric material, is sprayed onto the substrate 26 by AD method, the fine particles are attached onto the deposition allowable region A to form a film-like piezoelectric layer 27, thereby enabling easy formation of the layer 27 onto a part of the surface area of the substrate 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a piezoelectric actuator, an inkjet head manufactured using a so-called aerosol deposition method (AD method) in which a raw material is mixed with a gas and formed into a film by ejecting from a nozzle and colliding with a substrate. About.

As an example of a piezoelectric actuator used in an inkjet head or the like, a piezoelectric material layer including an ink flow path forming body in which a plurality of pressure chambers are formed, and a substrate constituting a part of a wall surface of each pressure chamber provided on the substrate There is a configuration in which the ink in the pressure chamber is ejected from a nozzle communicating with the pressure chamber (see, for example, Patent Document 1). In such a piezoelectric actuator, when the piezoelectric material layer is provided over the entire area of the substrate surface, one electrode (individual electrode) is individually arranged at a position corresponding to each pressure chamber on the upper surface of the piezoelectric material layer. By applying an electric field between the electrode and a conductive substrate used as a common electrode, the piezoelectric material layer is locally bent. However, in this case, vibration is also transmitted around the bent portion of the piezoelectric material layer, and as a result, the ejection speed and volume may vary when ink is ejected from the adjacent pressure chamber. For reasons such as preventing so-called crosstalk, it is desirable that the piezoelectric material layer is not provided over the entire area of the substrate surface, but only in a part of the region corresponding to the pressure chamber.
Japanese Patent Laid-Open No. 11-70653

  As a means for forming the piezoelectric material layer only in a partial region, for example, a resist having a predetermined pattern is formed on the substrate surface, and the piezoelectric material layer is formed on the entire upper surface by the aerosol deposition method (AD method). A method of removing the resist and leaving the piezoelectric material layer in a pattern on the substrate is conceivable. However, this method has a problem in that when the resist is removed, the piezoelectric material layer is divided, and the piezoelectric material layer on the substrate may be chipped or cracked.

  The present invention has been completed based on the above-described circumstances, and an object of the present invention is to provide a piezoelectric actuator, an ink jet head, and those capable of easily forming a piezoelectric material layer in a partial region of the substrate surface. A manufacturing method is provided.

  As a means for achieving the above object, the invention of claim 1 is a piezoelectric actuator for forming a piezoelectric material layer by spraying a carrier gas containing fine particles of a piezoelectric material onto a substrate surface and attaching the fine particles. In the manufacturing method, the film forming allowable range in which the fine particles of the piezoelectric material in the carrier gas are attached to the substrate surface in advance to form a film and the film formation in which the fine particles are prevented from adhering to the film form are inhibited. An inhibition region is provided, and then a carrier gas containing the fine particles is sprayed onto the substrate surface to form a piezoelectric material layer in the film formation allowable region.

  In the present invention, the phrase “inhibition of film formation due to adhesion of fine particles” means that the film formation inhibition region is less likely to form a film due to adhesion of the fine particles as compared to the allowable film formation range. When the carrier gas is sprayed, a very thin film (thin film that can be easily removed by a process such as heat treatment or peeling performed later) is formed in the film formation inhibition area compared to the film formation allowable area. Including cases where

  A second aspect of the present invention is a method for manufacturing a piezoelectric actuator in which a piezoelectric material layer is formed by spraying a carrier gas containing fine particles of a piezoelectric material onto one surface of the substrate to attach the fine particles. A film forming region provided with a film forming allowable region where the fine particles adhere to a film shape when the carrier gas is sprayed on and a film formation inhibiting region where the fine particles adhere to prevent the film from forming a film shape And a piezoelectric layer forming step in which a carrier gas containing the fine particles is sprayed on one surface of the substrate that has undergone the film formation region formation step to form a piezoelectric material layer in the film formation allowable region. Have

  According to a third aspect of the present invention, in the second aspect of the present invention, in the film formation region forming step, the film formation allowable region and the film formation inhibition region are made different by making the surface hardness different from each other. It has the characteristics in the place.

  According to a fourth aspect of the present invention, there is provided the method according to the third aspect, wherein a ratio value of the Vickers hardness Hv (b) of the film formation allowable region and the Vickers hardness Hv (p) of the fine particles is 0.39 ≦ Hv (p) / Hv (b) ≦ 3.08, and the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is less than 0.39 Or it has the characteristic in the value which exceeds 3.08.

  According to a fifth aspect of the present invention, there is provided the method according to the third aspect, wherein a ratio value of the Vickers hardness Hv (b) of the film formation allowable region and the Vickers hardness Hv (p) of the fine particles is 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43, and the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is less than 0.39. Or it has the characteristic in the value which exceeds 3.08.

  According to a sixth aspect of the present invention, in the method according to the third aspect, the value of the ratio between the Vickers hardness Hv (b) in the film formation allowable range and the Vickers hardness Hv (p) of the fine particles is 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43, and the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is less than 0.43. Or it has the characteristic in the value which exceeds 1.43.

  In the present invention, a film that is thinner than the film in the film formation allowable region may be formed in the film formation inhibition region, so the thin film formed in the film formation inhibition region is removed after the piezoelectric layer formation step. It is desirable to include the process to do.

  According to a seventh aspect of the present invention, in the method according to the third aspect, a ratio of the Vickers hardness Hv (b) in the film formation allowable region to the compressive fracture strength Gv (p) of the fine particles is 0.10 ≦ {Gv (P) / Hv (b)} × 100 ≦ 3.08, and the ratio between the Vickers hardness Hv (b) in the film formation inhibition region and the compression fracture strength Gv (p) of the fine particles is {Gv (P) / Hv (b)} × 100 <0.10 or {Gv (p) / Hv (b)} × 100> 3.08.

  According to an eighth aspect of the present invention, the ratio of the Vickers hardness Hv (b) in the film formation allowable range to the compressive fracture strength Gv (p) of the fine particles is 0.11 ≦ {Gv (P) / Hv (b)} × 100 ≦ 1.43, and the ratio between the Vickers hardness Hv (b) in the film formation inhibition region and the compression fracture strength Gv (p) of the fine particles is {Gv (P) / Hv (b)} × 100 <0.10 or {Gv (p) / Hv (b)} × 100> 3.08.

  According to a ninth aspect of the present invention, there is provided the method according to the third aspect, wherein the ratio of the Vickers hardness Hv (b) in the film formation allowable region to the compressive fracture strength Gv (p) of the fine particles is 0.11 ≦ {Gv (P) / Hv (b)} × 100 ≦ 1.43, and the ratio between the Vickers hardness Hv (b) in the film formation inhibition region and the compression fracture strength Gv (p) of the fine particles is {Gv (P) / Hv (b)} × 100 <0.11 or {Gv (p) / Hv (b)} × 100> 1.43.

  According to a tenth aspect of the present invention, in the method according to any one of the third to ninth aspects, in the film formation region forming step, a different hardness material layer having a surface hardness different from that of the substrate is patterned on one surface of the substrate. By forming, a region where one surface of the substrate that becomes the film formation allowable region is exposed and a region where the different hardness material layer that becomes the film formation inhibition region is formed are provided.

  The invention according to an eleventh aspect is characterized in that, in the tenth aspect, the different hardness material layer has an insulating property.

  According to a twelfth aspect of the invention, in any one of the second to eleventh aspects, the individual electrode for applying an electric field to the piezoelectric material layer on the piezoelectric material layer after the piezoelectric layer forming step. It is characterized in that it is provided with an electrode forming process for forming the electrode.

  According to a thirteenth aspect of the present invention, in the eleventh aspect, after the piezoelectric layer forming step, an electrode forming step of forming an individual electrode for applying an electric field to the piezoelectric material layer on the piezoelectric material layer. In addition, the electrode forming step is characterized in that a lead portion electrically connected to the individual electrode is formed on the different hardness material layer.

  According to a fourteenth aspect of the present invention, in the second aspect, in the film formation region forming step, the film formation allowable region is obtained by performing a surface treatment for adjusting a surface roughness of one surface of the substrate. It is characterized in that a region having a small surface roughness and a region having a large surface roughness serving as the film formation inhibition region are provided.

  According to a fifteenth aspect of the present invention, in the film forming region forming step according to the fifteenth aspect, the piezoelectric material fine particles in the carrier gas collide with a region which is the film forming inhibition region on one surface of the substrate. It is characterized in that a buffer liquid layer is provided to inhibit the fine particles from adhering to the film by reducing the speed.

  The invention of claim 16 is characterized in that, in the invention of claim 15, the buffer liquid layer is made of a liquid having non-volatility.

  The invention of claim 17 is characterized in that, in the invention of claim 2, the substrate is made of a conductive material and used as one electrode for applying an electric field to the piezoelectric material layer. Have.

  According to an eighteenth aspect of the present invention, there is provided an ink flow path forming body in which a common ink chamber and a plurality of ink flow paths from the common ink chamber to the nozzle through the pressure chamber are formed, and an actuator unit that changes the volume of the pressure chamber. A flow path forming body creating step for creating an ink flow path forming body in which a part of the pressure chamber is opened, and an actuator unit common to the ink flow path forming body A substrate fixing step of fixing a conductive substrate to be an electrode and closing the pressure chamber; and a carrier containing fine particles of piezoelectric material on a surface of the conductive substrate opposite to the fixing surface of the ink flow path forming body. Formation of a film forming region in which a film forming allowable region where the fine particles adhere to a film shape when a gas is blown and a film formation inhibiting region where the fine particles adhere and become a film shape are inhibited A piezoelectric layer forming step of spraying a carrier gas containing the fine particles to form a piezoelectric material layer as an active layer of the actuator unit in the film formation allowable region; and the actuator on the piezoelectric material layer. And an electrode forming step of forming individual electrodes of the unit.

  The invention according to claim 19 is a piezoelectric actuator in which a piezoelectric material layer is formed by spraying a carrier gas containing fine particles of a piezoelectric material on one surface of the substrate to adhere the fine particles, and on one surface of the substrate, A film forming allowable region in which the fine particles of the piezoelectric material in the carrier gas adhere to form a film and a film forming inhibition region in which the fine particles adhere to prevent the film from forming a film are provided. The piezoelectric material layer is formed in the region.

  According to a twentieth aspect of the present invention, in the film forming allowable region and the film formation inhibition region, a different hardness material layer having a surface hardness different from that of the substrate is formed on one surface of the substrate. It has the feature that it is made separately by doing.

  According to a twenty-first aspect of the present invention, in the film forming allowable region according to the twentieth aspect, the part of one surface of the substrate is exposed, and the film formation inhibition region is harder than the substrate. It is characterized in that it consists of a high material layer of different hardness.

  The invention of claim 22 is characterized in that, in any of claims 19 to 21, an individual electrode for applying an electric field to the piezoelectric material layer is formed so as to overlap the piezoelectric material layer. Have.

  According to a twenty-third aspect of the present invention, in the material according to the twenty-second aspect, the different hardness material layer is formed in the film formation inhibition region and has an insulating property, and the individual hardness layer is overlapped with the individual hardness material layer. It is characterized in that a lead portion electrically connected to the electrode is formed.

  According to a twenty-fourth aspect of the present invention, in the method according to the nineteenth aspect, the film formation inhibition area is formed by increasing the surface roughness of the substrate as compared with the film formation allowable area. Have

  According to a twenty-fifth aspect of the invention, in any one of the nineteenth to twenty-fourth aspects, the substrate is made of a conductive material and is used as a common electrode for applying an electric field to the piezoelectric material layer. It is characterized by

  The invention of claim 26 is an ink flow path forming body in which a common ink chamber and a plurality of ink flow paths from the common ink chamber to the nozzle through the pressure chamber are formed, and an actuator unit for changing the volume of the pressure chamber. The ink flow path forming body has a pressure chamber opening surface that opens a part of the pressure chamber, and the actuator unit is fixed to the pressure chamber opening surface and closes the pressure chamber. A conductive substrate serving as a common electrode of the actuator unit and a fine particle formed when a carrier gas containing fine particles of a piezoelectric material is sprayed on a surface opposite to the surface of the conductive substrate fixed to the ink flow path forming body. Formed in the film forming allowable area, the film forming allowable area that adheres until the film becomes a film, the film forming inhibition area that prevents the fine particles from adhering to the film shape, and A piezoelectric material layer serving as an active layer of effectuator eta unit, is formed in the film forming allowable range, has a characteristic where having the individual electrodes sandwiching the piezoelectric material layer between the conductive substrate.

<Invention of Claims 1, 2, 18, 18, 19 and 26>
When the carrier gas is sprayed by providing a film forming allowable area where the fine particles of the piezoelectric material in the carrier gas adhere to the substrate surface and a film formation inhibiting area where the film formation is inhibited In addition, the fine particles adhere to the film formation allowable region to form a film-like piezoelectric material layer. Thereby, the piezoelectric material layer can be easily formed in a partial region of the substrate surface.

<Invention of Claim 3 and Claim 20>
The film formation allowable area and the film formation inhibition area are created separately by making the surface hardness of each other different. That is, when a carrier gas containing fine particles of a piezoelectric material is sprayed, the film formation allowable region is set to a hardness that tends to form a film due to the adhesion of the fine particles, and the film formation inhibition region is formed into a film shape due to the adhesion of the fine particles. Since the hardness is difficult to become, it is possible to selectively form the piezoelectric material layer in the allowable film formation range.

<Invention of Claim 4>
The value of the ratio between the Vickers hardness Hv (b) in the allowable film formation range and the Vickers hardness Hv (p) of the fine particles is in the range of 0.39 ≦ Hv (p) / Hv (b) ≦ 3.08, The ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is set to a value less than 0.39 or more than 3.08, so that the piezoelectric material in the film formation inhibition region The film formation of the layer can be reliably inhibited, and the adhesion (film forming property) of the piezoelectric material layer in the film forming allowable range can be ensured.

<Invention of Claim 5>
The value of the ratio between the Vickers hardness Hv (b) in the allowable film formation range and the Vickers hardness Hv (p) of the fine particles is in the range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43, The ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is set to a value less than 0.39 or more than 3.08, so that the piezoelectric material in the film formation inhibition region The film formation of the layer is surely inhibited, and the piezoelectric material layer can be efficiently formed in the film formation allowable range.

<Invention of Claim 6>
The value of the ratio between the Vickers hardness Hv (b) in the allowable film formation range and the Vickers hardness Hv (p) of the fine particles is in the range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43, By setting the ratio of the Vickers hardness Hv (b) in the film formation inhibition area to the Vickers hardness Hv (p) of the fine particles to a value less than 0.43 or more than 1.43, the film formation is allowed in the film formation allowable area. A layer thicker than the piezoelectric material layer formed in the film inhibition region can be efficiently formed.

<Invention of Claim 7>
The ratio of the Vickers hardness Hv (b) in the allowable film formation range to the compressive fracture strength Gv (p) of the fine particles is in the range of 0.10 ≦ {Gv (p) / Hv (b)} × 100 ≦ 3.08 Yes, the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.10 or {Gv (p ) / Hv (b)} × 100> 3.08, the film formation of the piezoelectric material layer in the film formation inhibition region is surely inhibited, and the adhesion (film formation property) of the piezoelectric material layer in the film formation allowable region. ) Can be secured.

<Invention of Claim 8>
The ratio of the Vickers hardness Hv (b) in the allowable film formation range to the compression fracture strength Gv (p) of the fine particles is in the range of 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43 And the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.10 or { By satisfying Gv (p) / Hv (b)} × 100> 3.08, the film formation of the piezoelectric material layer in the film formation inhibition region is reliably inhibited, and the piezoelectric material layer is efficiently formed in the film formation allowable region. Can be formed.

<Invention of Claim 9>
The ratio of the Vickers hardness Hv (b) in the allowable film formation range to the compression fracture strength Gv (p) of the fine particles is in the range of 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43 And the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.11 or { By setting Gv (p) / Hv (b)} × 100> 1.43, a layer thicker than the piezoelectric material layer formed in the film formation inhibition region can be efficiently formed in the film formation allowable region. .

<Invention of Claims 10 and 21>
When the carrier gas containing fine particles of piezoelectric material is sprayed on the substrate exposed to the film formation allowable region, the fine particles adhere to the hardness that tends to form a film, and the different hardness material formed in the film formation inhibition region By forming the layer to have a hardness that prevents the fine particles from adhering to form a film, a film formation allowable region and a film formation inhibition region can be created separately.

<Invention of Claim 11>
Since the different hardness material layer has insulating properties, it also functions as an insulating layer, and electrical wiring is easy.

<Invention of Claims 12 and 22>
Since an individual electrode for applying an electric field is formed on the piezoelectric material layer, each piezoelectric material layer can be driven individually.

<Invention of Claims 13 and 23>
Also, by forming the lead portion connected to the individual electrode on the top surface of the different hardness material layer having insulation, the different hardness material layer also serves as the insulation layer of the electrical wiring, so compared with the case where the insulation layer is formed separately. Thus, the structure and the manufacturing process are simplified, and the cost can be reduced.

<Invention of Claims 14 and 24>
By adjusting the surface roughness of the substrate, the allowable film forming range is set to a surface roughness that tends to be formed into a film shape due to adhesion of the fine particles of the piezoelectric material in the carrier gas, and the film forming inhibition region is formed by the adhesion of the fine particles to the film. By setting the surface roughness to be less likely to be a shape, the piezoelectric material layer can be selectively formed in a film formation allowable region.

<Invention of Claim 15>
When the fine particles in the carrier gas collide with the buffer liquid layer provided in the film formation inhibition region, the velocity of the fine particles is reduced, and the velocity energy necessary for adhering to the film is lost, so that the film is not formed.

<Invention of Claim 16>
Since the buffer liquid layer is made of a non-volatile liquid, it is difficult to volatilize even when the pressure is reduced in the film forming chamber in the piezoelectric layer forming step.

<Invention of Claims 17 and 25>
When the substrate is formed of a conductive material and used as one electrode for applying an electric field to the piezoelectric material layer, it is not necessary to provide one electrode in particular, which is advantageous in terms of manufacturing cost.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the inkjet head 10 of the present embodiment (corresponding to the “inkjet head” of the present invention) cut along the longitudinal direction of the pressure chamber 12, and FIG. FIG. 3 is a cross-sectional view taken along the hand direction, and FIG. 3 is a plan view of the inkjet head 10, and each drawing shows a part of the inkjet head 10.

The ink jet head 10 includes an ink flow path forming body 13 including a plurality of pressure chambers 12 in which ink 11 is accommodated and an upper surface is opened, and an actuator unit 14 fixed to the upper surface of the ink flow path forming body 13. It has.
The ink flow path forming body 13 has a flat plate shape as a whole, and the nozzle plate 16, the manifold plate 17, the flow path plate 18 and the pressure chamber plate 19 are sequentially laminated, and the plates 16, 17, 18, 19 are stacked. It is the structure which mutually joined with the epoxy-type thermosetting adhesive agent.

  The pressure chamber plate 19 is formed of a metal material such as stainless steel, and a plurality of pressure chambers 12 are arranged in the inside thereof. Each pressure chamber 12 is elongated in one direction and has a substantially oval shape when viewed from above. Similarly, the flow path plate 18 is formed of a metal material such as stainless steel, and a manifold flow path 20 and a pressure flow path 21 communicating with both ends of the pressure chamber 12 are provided therein. The manifold plate 17 is also formed of a metal material such as stainless steel, and extends in the short direction of the pressure chamber 12 and communicates with each manifold channel 20 and is connected to an ink tank (not shown). An ink chamber 22 and a nozzle channel 23 connected to the pressure channel 21 are formed. Further, the nozzle plate 16 is formed of a polyimide-based synthetic resin material, and a nozzle 24 for ejecting the ink 11 is connected to the nozzle flow path 23. In this way, a flow path is formed from the common ink chamber 22 connected to the ink tank to the nozzle 24 through the manifold flow path 20, the pressure chamber 12, the pressure flow path 21, and the nozzle flow path 23.

  The actuator unit 14 includes a substrate 26 that closes the pressure chamber 12. The substrate 26 is formed of a conductive metal material such as stainless steel, as will be described later, and is bonded to the upper surface of the pressure chamber plate 19 with an epoxy-based thermosetting adhesive, whereby the substrate 26 is made of ink. The flow path forming body 13 is fixed so as to cover the entire top surface. The substrate 26 is connected to the ground of a drive circuit (not shown) and is also used as a common electrode.

  On the upper surface of the substrate 26 in the actuator unit 14, a piezoelectric material layer 27 serving as an active layer of the actuator unit 14 is formed at each position corresponding to each pressure chamber 12. Each piezoelectric material layer 27 is made of a ferroelectric piezoelectric ceramic material such as lead zirconate titanate (PZT) and has a uniform thickness as a whole, and is slightly more than the pressure chamber 12 as viewed from above. Has a small, roughly oval shape. A different hardness material layer 28 made of an insulating material having a hardness different from that of the substrate 26 is formed on the entire surface of the upper surface of the substrate 26 except for the region where the piezoelectric material layer 27 is provided. The different hardness material layer 28 has a uniform thickness as a whole and is thinner than the piezoelectric material layer 27. On the upper surface of the substrate 26, a region corresponding to the piezoelectric material layer 27 is defined as a film formation allowable region A and a region corresponding to the different hardness material layer 28 is defined as a film formation inhibition region B. In the formation process, the fine film of the piezoelectric material in the carrier gas adheres to form a film in the allowable film formation area A, and the fine film adheres to form a film in the film formation inhibition area B. ing.

  In addition, on the upper surface of the actuator unit 14, individual electrodes 30 made of a thin film conductor are formed on the entire upper surface of each piezoelectric material layer 27. Further, on the upper surface of the different hardness material layer 28, a plurality of lead portions 31 that are also made of a thin-film conductor and are connected to the individual electrodes 30 are formed. Each lead part 31 is electrically connected to a drive circuit (not shown). The piezoelectric material layer 27 is polarized so as to be polarized in the thickness direction. When the potential of the individual electrode 30 is higher than that of the substrate 26 which is a common electrode by the drive circuit, the piezoelectric material layer 27 An electric field is applied in the polarization direction (direction from the individual electrode 30 toward the substrate 26). Then, the piezoelectric material layer 27 expands in the thickness direction and contracts in the direction along the surface of the substrate 26. Thereby, as shown in the left part of FIG. 2, the piezoelectric material layer 27 and the substrate 26 (that is, the actuator unit 14) are locally deformed so as to protrude toward the pressure chamber 12 (unimorph deformation). For this reason, the volume of the pressure chamber 12 decreases, the pressure of the ink 11 increases, and the ink 11 is ejected from the nozzle 24. Thereafter, when the individual electrode 30 is returned to the same potential as that of the substrate 26 which is a common electrode, the piezoelectric material layer 27 and the substrate 26 have the original shape, and the volume of the pressure chamber 12 returns to the original volume. Are sucked from the common ink chamber 22.

Next, the manufacturing method of the inkjet head 10 of this embodiment is demonstrated.
[Flow channel forming process]
First, the manifold plate 17, the flow path plate 18 and the pressure chamber plate 19 except for the nozzle plate 16 are stacked and joined in a state where they are aligned with each other. At this time, holes corresponding to the nozzle 24, the pressure chamber 12, the common ink chamber 22, and the like are provided in advance in each of the plates 16, 17, 18, and 19. Thereby, the ink flow path forming body 13 in a state where the upper surface of each pressure chamber 12 is opened is created. Since the nozzle plate 16 is formed of a synthetic resin material that is weak against heat, the nozzle plate 16 may be deformed by an annealing process in a piezoelectric layer forming process, which will be described later. Therefore, the nozzle plate 16 is bonded to the manifold plate 17 after the piezoelectric layer forming process. Is done.

[Board fixing process]
Next, the substrate 26 of the actuator unit 14 is overlapped and bonded to the upper surface of the pressure chamber plate 19 of the ink flow path forming body 13, and the pressure chambers 12 are closed by the substrate 26.

[Film formation region formation process]
Next, as shown in FIG. 4 and FIG. 5A, by forming a different hardness material layer 28 having a surface hardness different from that of the substrate 26 on the substrate 26, a film forming allowable area A is obtained. A region where the surface of the substrate 26 is exposed and a region where the different hardness material layer 28 serving as the film formation inhibition region B is formed are provided. In the next piezoelectric layer forming step, a carrier gas containing fine particles of a piezoelectric material such as lead zirconate titanate (PZT) is sprayed on the surface of the substrate 26 to attach the fine particles in a film form. The film formation allowable area A is an area where the fine particles adhere until the carrier gas is sprayed, that is, an area where the piezoelectric material layer 27 is formed. This is a region where the fine particles are prevented from adhering to a film when the carrier gas is sprayed.

  In the present embodiment, the film formation allowable area A and the film formation inhibition area B are distinguished by the difference in surface hardness. The present inventors have found that the relationship between the hardness of the substrate and the hardness of the fine particles of the piezoelectric material affects the result of whether or not the piezoelectric layer is formed. When the value of the ratio between the Vickers hardness Hv (b) and the Vickers hardness Hv (p) of the fine particles of the piezoelectric material is 0.39 ≦ Hv (p) / Hv (b) ≦ 3.08, the piezoelectric material I found that a film was formed. Furthermore, it has been found that the piezoelectric material layer can be formed efficiently in a short time when it is in the range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43. In addition, the present inventors have found that instead of the relationship between the hardness of the fine particles and the hardness of the substrate surface, the relationship between the compressive fracture strength of the fine particles and the hardness of the substrate surface may be used as an index. When the ratio of the allowable range of Vickers hardness Hv (b) to the compressive fracture strength Gv (p) of the fine particles is in the range of 0.10 ≦ {Gv (p) / Hv (b)} × 100 ≦ 3.08 We found that a piezoelectric material was deposited on the film. Furthermore, it has been found that the piezoelectric material layer can be efficiently formed in a short time when it is in the range of 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43. In the present embodiment, the surface hardness of each of the film formation allowable area A and the film formation inhibition area B is determined based on this condition.

The substrate 26 is made of a conductive metal material having a hardness that is easy to form a film when fine particles adhere to the carrier gas containing fine particles of the piezoelectric material. When the piezoelectric material is lead zirconate titanate (PZT), the Vickers hardness of the fine particles is Hv 300 to 400, and the compression fracture strength is 0.8 to 4.0 GPa. A Vickers hardness of the surface of Hv 280 to 700 is selected so as to satisfy. Specifically, for example, stainless steel of Hv450 to 600, nickel alloy, nickel, etc. are used.
On the other hand, the different hardness material layer 28 is made of a material having a hardness different from that of the substrate 26, and the fine particles are applied to the substrate 26 when a carrier gas containing fine particles of the piezoelectric material is sprayed in a piezoelectric layer forming process described later. It is made of an insulating material having a low dielectric constant and a hardness that is less likely to adhere and form a film. When the piezoelectric material is lead zirconate titanate (PZT), the material layer with different hardness is selected such that the surface Vickers hardness is less than Hv280 or more than Hv700.

As the insulating material having a hardness lower than that of the substrate 26 and having a low dielectric constant, for example, a polyimide resin having an Hv of 100 or less is used. Besides, an epoxy resin, a polyetherimide resin, a polyphenylene sulfide resin, a fluororesin, a fluorinated polymer, A crystalline polyolefin resin, syndiotactic polystyrene resin, organic silica, fluorinated carbon, COPNA resin, oxazole resin, paraxylylene resin, or the like may be used.
Various methods are used to form a polyimide resin or the like as the different hardness material layer 28 in a pattern on the substrate 26. For example, an electrolytic deposition method (plating method, for example, placing a conductive substrate in a polyimide solution) is used. Then, a polyimide film is formed on the substrate by applying a voltage between the electrodes.) Alternatively, a polyimide resin layer is formed over the entire surface of the substrate 26 by spin coating, and then the film formation is permitted in the polyimide resin layer. The different hardness material layer 28 is formed in a pattern by removing the portion corresponding to the region A by laser irradiation.

Further, as the different hardness material layer 28, an insulating material having a higher hardness than that of the substrate 26 and having a low dielectric constant can be used. For example, alumina having Hv 1400 to 2000 is used, and in addition, silicon nitride, silicon oxide, nitride Aluminum, silicon carbide, diamond-like carbon having Hv 1000 to 2000, TiN having Hv 1500 to 2200, and the like are used.
In order to form alumina or the like as a different hardness material layer 28 on the upper surface of the substrate 26 in a pattern, for example, the following (A) or (B) may be used.
(A) First, an alumina layer is formed on the entire surface of the substrate 26 by CVD (vapor phase epitaxy) or AD. Next, the alumina layer is irradiated with a laser to remove a portion corresponding to the deposition allowable area A.
(B) First, a resist is patterned and formed in a region corresponding to the film formation inhibition region on the surface of the substrate 26. Next, an alumina layer is formed on the entire surface of the substrate 26 by CVD or AD. Finally, the resist is removed. In this case, since the alumina layer is formed very thin as compared with the piezoelectric material layer 27, the occurrence of chipping and cracks does not cause a problem.

[Piezoelectric layer forming process]
Next, the piezoelectric material layer 27 of the actuator unit 14 is formed by an aerosol deposition method (AD method). FIG. 6 is a schematic view of a film forming apparatus for forming the piezoelectric material layer 27. Reference numeral 35 denotes a gas cylinder for supplying an inert gas such as helium, argon, nitrogen, or the like as a carrier gas, and the carrier gas is sent from the gas cylinder 35 to the aerosol generator 37 through the introduction pipe 36. The aerosol generator 37 includes an aerosol chamber 38 that can be filled with a fine particle powder of a piezoelectric material, and a vibration device 39 that vibrates the aerosol chamber 38, and the piezoelectric material filled in the aerosol chamber 38. While stirring the fine particle powder 40, the carrier gas is fed into the aerosol chamber 38, whereby the fine particle powder 40 is suspended in the gas to be aerosolized. In addition, as carrier gas, inert gas, such as helium, argon, nitrogen, air, oxygen, etc. can be used, for example. As the piezoelectric material, for example, lead zirconate titanate (PZT), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, zinc oxide, or the like can be used.

  The aerosolized carrier gas containing fine particles of the piezoelectric material is sent from the aerosol chamber 38 to the nozzle 43 provided in the film forming chamber 42 through the aerosol introduction tube 41. A stage 44 for attaching the substrate 26 to the tip of the nozzle 43 is provided in the film forming chamber 42, and carrier gas is injected from the nozzle 24 toward the substrate 26. In addition, a vacuum pump 46 is connected to the film forming chamber 42 via a powder recovery device 45 so that the inside of the film forming chamber 42 is depressurized.

  With the film forming apparatus, a carrier gas containing fine particles of the piezoelectric material is sprayed evenly over the entire surface of the substrate 26 that has undergone the film forming region forming step. Then, as shown in FIG. 5B, in the film forming allowable region A, the piezoelectric material fine particles in the carrier gas collide with and adhere to the exposed surface of the substrate 26, and are deposited to form a film-like piezoelectric material layer. 27 is formed. On the other hand, in the film formation inhibition zone B, the fine particles of the piezoelectric material in the carrier gas collide with the different hardness material layer 28. At this time, since the different hardness material layer 28 has a hardness that makes it difficult for the fine particles to adhere and form a film when the carrier gas containing the fine particles of the piezoelectric material is sprayed, the fine particles have the different hardness material layer 28. Even if it adheres to the film, it does not become a film with a thickness similar to that in the allowable film formation area A. In this way, the piezoelectric material layer 27 is selectively formed in the film formation allowable area A on the surface of the substrate 26. Thereafter, the piezoelectric material layer 27 is annealed as necessary. Note that when a thin film of piezoelectric material is formed on the different hardness material layer 28 as described above, such a thin film often has low adhesion to the substrate 26, and thus often peels off during the annealing process. Further, a process for removing the thin film of the piezoelectric material formed on the different hardness material layer 28 may be performed. In this process, the adhesive tape may be peeled off after the adhesive film A and the film formation inhibition area B are applied, or the substrate may be hit from the back surface.

[Individual electrode formation process]
Subsequently, as shown in FIG. 5C, the individual electrodes 30 are formed on the upper surface of each piezoelectric material layer 27, and a plurality of lead portions 31 connected to the individual electrodes 30 are formed on the upper surface of the different hardness material layer 28. Form. In order to form the individual electrode 30 and the lead portion 31, for example, after forming a conductor film over the entire area of the piezoelectric material layer 27 and the different hardness material layer 28, a predetermined pattern is formed by using a photolithography etching method. Alternatively, printing may be performed directly on the upper surfaces of the piezoelectric material layer 27 and the different hardness material layer 28.

  After the individual electrode formation step, an electric field stronger than that in the normal ink ejection operation is applied between the individual electrode 30 and the common electrode substrate 26 to polarize the piezoelectric material layer 27 between both electrodes in the thickness direction (polarization). processing). Thus, the inkjet head 10 is completed.

  Next, a description will be given of a test conducted by the present inventor based on his / her own knowledge to find a condition for separately forming the film formation allowable area A and the film formation inhibition area B.

[Test 1 Substrate hardness and deposition rate]
<Data 1-1>
As the substrate, a stainless (SUS430) plate having a Vickers hardness of Hv290 on the surface of the substrate on which aerosol is sprayed was used. The substrate surface was polished so that the roughness was Rz ≦ 0.7. As the material particles, PZT having an average particle diameter of 0.3 to 1 μm, Vickers hardness Hv 300 to 400, and compressive fracture strength 0.8 to 4.0 GPa was used.
The surface hardness of the stainless steel substrate was adjusted by heating the substrate at 400 to 800 ° C. in air or in vacuum to change its surface properties. Moreover, the measurement of Vickers hardness was performed by the nanoindentation method. The test was performed at a test force F = 0.015 N using a Nano-Hardness Tester manufactured by + csm as a measuring device and a Barcovic indenter as an indenter. Moreover, the measurement of compressive fracture strength was similarly performed using Nano-Hardness Tester manufactured by + csm as a measuring device, and was calculated from the compressive force Fd at the time of particle fracture by the formula (1).
Gv (p) = 0.9 × Fd / d ² (1)
Where Gv (p): compressive fracture strength (unit: GPa)
Fd: compression force at the time of particle breakage (unit: kN)
d: Diameter of the particle (unit: mm)

  A piezoelectric material layer having a thickness of 10 μm was formed on the substrate by the same film forming apparatus as in the above embodiment. The film forming conditions are as follows: film forming chamber pressure 150 Pa, aerosol chamber pressure 30000 Pa, nozzle opening size 10 mm × 0.4 mm, carrier gas type He, nozzle substrate relative speed 1.2 mm / sec, nozzle-substrate distance 10-20 mm, The particle speed was 250 m / sec. The deposition rate of the piezoelectric material layer was measured.

<Data 1-2>
Film formation was performed in the same manner as Data 1-1 except that a stainless steel (SUS430) plate having a Vickers hardness of Hv440 on the substrate surface onto which aerosol was sprayed was used.

<Data 1-3>
The film was formed in the same manner as Data 1-1 except that a Pt film was previously formed by sputtering on the surface of the stainless steel (SUS430) plate on which aerosol was sprayed, and the substrate had a Vickers hardness of Hv700. The film formation rate was examined.

<Data 1-4>
Except for using a gold-plated plate having a Vickers hardness of Hv130 as the substrate, film formation was performed in the same manner as Data 1-1, and the film formation rate was examined.

<Data 1-5>
Except for using a Vickers hardness Hv210 stainless steel (SUS430) plate as the substrate, film formation was performed in the same manner as Data 1-1, and the film formation rate was examined.

<Data 1-6>
Except for using a Vickers hardness Hv280 stainless steel (SUS430) plate as a substrate, film formation was performed in the same manner as Data 1-1, and the film formation rate was examined.

<Data 1-7>
Except for using a platinum plate having a Vickers hardness of Hv770 with a surface of 850 ° C. to 1200 ° C. coated with paste-form Pt on the surface of the ceramic plate on which aerosol is sprayed, the data 1-1 and Film formation was performed in the same manner, and the film formation rate was examined.

<Results and discussion>
Tables 1 and 2 show data on the substrate material, Vickers hardness, and deposition rate.

  As shown in Tables 1 and 2, when the substrate hardness was Hv130, the film formation rate was as low as 0.13 μm / sec. When the hardness of the substrate was increased, the film formation rate gradually increased, particularly rapidly in the vicinity of the hardness Hv280, and reached a maximum at 0.29 μm / sec when the hardness was Hv290. This is presumably because the fine particles that collided with the substrate surface were crushed so that the fine particles strongly adhered to the substrate or the previously adhered particles.

  When the hardness of the substrate was further increased, the film formation rate was gradually decreased, and the film formation rate was significantly decreased in the vicinity of Hv700. This is presumably because the fine particles were repelled on the substrate surface and became difficult to sink into the substrate surface. In the range up to the substrate hardness Hv700, the film formation rate was practically good, and it was confirmed by visual observation that the piezoelectric material layer was formed without gaps and the adhesion was good. When the hardness was further increased, the film formation rate further decreased.

  As described above, the Vickers hardness Hv (b) of the substrate in the film formation allowable range is set to a range of 130 to 770, that is, the Vickers hardness Hv (b) of the surface on the substrate where the fine particles adhere to The ratio of hardness to Hv (p) is in the range of 0.39 ≦ Hv (p) / Hv (b) ≦ 3.08, or the Vickers hardness Hv ( By setting the ratio of b) to the compressive fracture strength Gv (p) of the fine particles in the range of 0.10 ≦ {Gv (p) / Hv (b)} × 100 ≦ 3.08, the film growth is ensured. It was confirmed that it could be expected. Among these, in particular, the Vickers hardness Hv (b) of the substrate in the film formation allowable range is set to a range of 280 to 700, that is, the Vickers hardness Hv (b) and the fine particles on the surface on the substrate where the fine particles adhere. The ratio of the Vickers hardness to Hv (p) is in the range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43, or the Vickers hardness of the surface on the side where the fine particles adhere to the substrate Adhesion is sufficient by setting the ratio of Hv (b) to the compressive fracture strength Gv (p) of the fine particles in the range of 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43. It has been found that a piezoelectric material layer satisfying the above requirements is preferable because it is reliably formed in a short time. Further, among them, in particular, the Vickers hardness Hv (b) of the substrate in the film forming allowable range is in the range of 290 to 440, that is, 0.68 ≦ Hv (p) / Hv (b) ≦ 1.38 or 0. By setting the range of 18 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.38, the film forming speed for forming the piezoelectric material layer is stable at high speed, and the productivity and manufacturing cost (particulate material) It has been found that a method for manufacturing a piezoelectric material layer that is excellent in terms of cost can also be realized.

[Test 2 Influence of aerosol injection speed on success or failure of film formation]
Next, the success or failure of film formation when the aerosol injection speed was changed was examined. The substrate and material particles were the same as those in Data 1-1, and the particle velocity of the material particles was selected in the range of 150 m / s to 400 m / s. The other film forming conditions were the same as those in Data 1-1.

<Results and discussion>
Table 3 shows data relating to the success or failure of film formation when the particle velocity was changed. When the film formation rate was 0.1 μm / s or more, “◯” was displayed, and when it was less than 0.1 μm / s, “X” was displayed. The combination of the particle speed and the hardness ratio that were not measured was indicated as “−”.

  As shown in Table 3, when the ratio of the Vickers hardness Hv (b) of the surface on which the aerosol of the substrate is sprayed and the Vickers hardness Hv (p) of the fine particles is in the range of 0 to 0.25, the aerosol No film was formed even when the particle speed was changed within the range of 200 m / s to 400 m / s. However, when the ratio of Hv (b) to Hv (p) is in the range of 0.25 to 3.0, the aerosol particle velocity is set to any value within the range of 150 m / s to 400 m / s. Even so, film formation was confirmed (except for the combination of hardness ratio and particle speed at which the film formation speed was not measured). From the above results, it is considered that the influence of the aerosol particle velocity on the success or failure of the film formation is small.

  As described above, according to the present embodiment, the film formation allowable range A in which the fine particles of the piezoelectric material in the carrier gas are attached to the surface of the substrate 26 and the film formation is inhibited, and the film formation is inhibited. By providing the region B, when the carrier gas is sprayed, the fine particles adhere to the film formation allowable region A and the piezoelectric material layer 27 is formed. Thereby, the piezoelectric material layer 27 can be easily formed in a partial region of the surface of the substrate 26. Therefore, since it is not necessary to divide the piezoelectric material layer as in the prior art, it is possible to prevent the piezoelectric material layer from being chipped or cracked.

  Further, the film formation allowable area A and the film formation inhibition area B are made different by making the surface hardness of each other different. That is, when the carrier gas containing the fine particles of the piezoelectric material is sprayed on the surface of the substrate 26, the film formation allowable area A is set to a hardness at which the fine particles adhere to the film and the film formation inhibition area B is the fine particles. Therefore, the piezoelectric material layer 27 can be selectively formed in the film formation allowable region A.

  Further, the ratio of the Vickers hardness Hv (b) in the film formation allowable range A and the Vickers hardness Hv (p) of the fine particles is in a range of 0.39 ≦ Hv (p) / Hv (b) ≦ 3.08. The ratio of the Vickers hardness Hv (b) in the film formation inhibition zone B to the Vickers hardness Hv (p) of the fine particles is set to a value less than 0.39 or more than 3.08, or film formation The ratio of the Vickers hardness Hv (b) in the allowable range and the compressive fracture strength Gv (p) of the fine particles is in the range of 0.10 ≦ {Gv (p) / Hv (b)} × 100 ≦ 3.08, The ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compressive fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.39 or {Gv (p) / By ensuring that Hv (b)} × 100> 3.08, the film forming property of the piezoelectric material layer 27 in the film forming allowable region A is secured. Moni, the piezoelectric material layer 27 can be reliably inhibited to prevent deposition in the film deposition zone of inhibition B.

  Further, the ratio of the Vickers hardness Hv (b) in the allowable film formation range A to the Vickers hardness Hv (p) of the fine particles is in a range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43. The ratio of the Vickers hardness Hv (b) in the film formation inhibition zone B to the Vickers hardness Hv (p) of the fine particles is set to a value less than 0.39 or more than 3.08, or film formation The ratio between the Vickers hardness Hv (b) in the allowable range and the compressive fracture strength Gv (p) of the fine particles is in the range of 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43, The ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compressive fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.10 or {Gv (p) / By satisfying Hv (b)} × 100> 3.08, the piezoelectric material layer 27 can be efficiently formed in the deposition allowable region A. Can be, piezoelectric material layer 27 can be reliably inhibited to prevent deposition in the film deposition zone of inhibition B.

  Further, the ratio of the Vickers hardness Hv (b) in the allowable film formation range A to the Vickers hardness Hv (p) of the fine particles is in a range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43. The ratio of the Vickers hardness Hv (b) in the film formation inhibition zone B to the Vickers hardness Hv (p) of the fine particles is set to a value less than 0.43 or more than 1.43, or film formation The ratio between the Vickers hardness Hv (b) in the allowable range and the compressive fracture strength Gv (p) of the fine particles is in the range of 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43, The ratio between the Vickers hardness Hv (b) in the film formation inhibition region and the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.11 or {Gv (p) /Hv(b)}×100>1.43 so that the piezoelectric film formed in the film formation inhibition area B in the film formation allowable area A The thicker layer than postal layer 27 can be efficiently formed. In this case, since a thin film is also formed in the film formation inhibition region B, it is desirable to perform a process for removing the thin film.

Further, the substrate 26 exposed to the film formation allowable area A is formed in the film formation inhibition area B with a hardness that the fine particles adhere to easily form a film when the carrier gas containing the fine particles of the piezoelectric material is sprayed. By forming the different hardness material layer 28 to a hardness that prevents the fine particles from adhering to a film shape, the film formation allowable area A and the film formation inhibition area B can be formed separately.
Moreover, since the different hardness material layer 28 has insulation, it functions also as an insulating layer and electrical wiring is easy.
Moreover, since the individual electrode 30 for applying an electric field is formed on the piezoelectric material layer 27, each piezoelectric material layer 27 can be driven individually.

Further, by forming the lead portion 31 connected to the individual electrode 30 on the upper surface of the different hardness material layer 28 having an insulating property, the different hardness material layer 28 also serves as an insulating layer of the electric wiring, so that the insulating layer is formed separately. Compared to the case, the structure and the manufacturing process are simplified, and the cost can be reduced.
In addition, since the substrate 26 is formed of a conductive material and is used as one electrode for applying an electric field to the piezoelectric material layer 27, it is not necessary to provide one electrode in particular, and in terms of manufacturing cost. It will be advantageous.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the inkjet head 50 of the present embodiment, the different hardness material layer 52 provided in a region corresponding to the film formation inhibition region B on the surface of the substrate 26 in the actuator unit 51 has conductivity. Therefore, for the individual electrode 30 formed on the upper surface of each piezoelectric material layer 27, instead of the lead portion 31 of the first embodiment, the conductive path 54 of the flat cable 53 connected to a drive circuit (not shown). One end is connected. Other structures are almost the same as those of the first embodiment.

The substrate 26 is formed of the same material as that described in the first embodiment, and when a carrier gas containing fine particles of the piezoelectric material is sprayed in the piezoelectric layer forming step, the fine particles adhere to form a film. For example, stainless steel with Hv 450 to 600 is used.
Further, the different hardness material layer 52 is made of a material having conductivity and a hardness different from that of the substrate 26, and when the carrier gas containing the fine particles of the piezoelectric material is sprayed in the piezoelectric layer forming step, the substrate is formed. Compared to H.26, the hardness is less likely to form a film due to adhesion of fine particles.
As the conductive material having a hardness lower than that of the substrate 26, for example, aluminum having about Hv80 is used. Further, as the conductive material having a hardness higher than that of the substrate 26, for example, hard chromium plating of about Hv1000 is used.
The inkjet head 50 according to the present embodiment can also be manufactured in substantially the same procedure as the inkjet head 10 according to the first embodiment.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIGS. In the following description, the same components as those in the above embodiments are denoted by the same reference numerals and description thereof is omitted.
In the inkjet head 60 of the present embodiment, the surface roughness of the film formation inhibition region B where the piezoelectric material layer 27 is not formed on the surface of the substrate 62 of the actuator unit 61 is the film formation allowance where the piezoelectric material layer 27 is formed. It is made larger than the surface roughness of the area A. That is, in the present embodiment, the film formation allowable area A and the film formation inhibition area B are created by making the surface roughness different from each other, and the film formation allowable area A is piezoelectric in the piezoelectric layer forming step. When a carrier gas containing fine particles of material is sprayed, the surface roughness is such that the fine particles are likely to adhere to form a film, and the film formation inhibition region B has a surface roughness larger than the film formation allowable region A, When the carrier gas is sprayed, the surface roughness is set so that the fine particles are not easily attached to form a film.

In the film formation region forming step, first, a substrate 62 fixed to the upper surface of the ink flow path forming body 13 in the substrate fixing step is prepared. As the substrate 62, the same material as that described in the first embodiment can be used, and for example, stainless steel of Hv450 to 600 is used. Further, the upper surface of the substrate 62 has a sufficiently small surface roughness over the entire area (for example, Ra: 1 μm or less). Then, a resist 63 is formed on the upper surface of the substrate 62 by patterning in a region corresponding to the film formation allowable region A (see FIG. 10A). Next, an etching process for roughening the surface is performed on the surface of the substrate 62 (see FIG. 10B), and the surface roughness of the region without the resist 63 on the surface of the substrate 62 is increased (for example, Ra: 2 μm or more). To do. Subsequently, the resist 63 is removed (see FIG. 10C). Thereby, the film formation allowable area A with a small surface roughness and the film formation inhibition area B with a large surface roughness are formed in a pattern on the surface of the substrate 62.
Moreover, you may perform this process as follows, for example. A mold that has been patterned in advance so that the surface roughness of the region corresponding to the film formation inhibition region B is large and the surface roughness of the region corresponding to the film formation allowable region is small is prepared. By pressing against the surface of the substrate 62 having a small roughness over the entire region, the surface roughness of the region corresponding to the film formation inhibition region B is increased.

  Next, in the piezoelectric layer forming step, when a carrier gas containing fine particles of piezoelectric material is sprayed on the surface of the substrate 62, the fine particles adhere well and deposit in a film form in the allowable film formation area A with a small surface roughness. (See FIG. 10D). On the other hand, in the film formation inhibition region B having a large surface roughness, the fine particles are only slightly attached and do not form a film, or even if a film is formed, the film is much thinner than the film formation allowable region A. Therefore, it can be easily peeled later.

  According to the present embodiment, by adjusting the surface roughness of the substrate 62, the film formation allowable area A is set to a surface roughness that tends to form a film due to adhesion of fine particles of the piezoelectric material in the carrier gas. The piezoelectric material layer 27 can be selectively formed in the film formation allowable region A by setting the region B to have a surface roughness that prevents the fine particles from adhering to form a film.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the following description, the same components as those in the above embodiments are denoted by the same reference numerals and description thereof is omitted.
In the ink jet head (not shown) of this embodiment, the buffer liquid layer 70 is provided in a region corresponding to the film formation inhibition region B on the upper surface of the substrate 26. The buffer liquid layer 70 is a layer for inhibiting the fine particles from adhering to the film shape by reducing the collision speed of the fine particles of the piezoelectric material in the carrier gas in the piezoelectric layer forming step. As the buffer liquid layer 70, a liquid having a non-volatile property and a high viscosity is used. For example, an oil-based liquid such as silicon oil or soybean oil is used. Since the buffer liquid layer 70 is made of a non-volatile liquid, it does not easily volatilize even when the pressure is reduced in the film formation chamber 42 in the piezoelectric layer forming process. Further, since the buffer liquid layer 70 is made of a liquid having a high viscosity, it hardly flows on the substrate 26 and the pattern stability is good.

In the film formation region forming step, the buffer liquid layer 70 is formed by coating the aforementioned liquid on the surface of the substrate 26 in a pattern by a transfer method or an ink jet method (see FIG. 11A). It is formed in a region corresponding to B. For the substrate 26, the same materials as those described in the first embodiment can be used. For example, stainless steel of Hv450 to 600 is used.
Next, when a carrier gas containing fine particles of piezoelectric material is sprayed onto the surface of the substrate 26 in the piezoelectric layer forming step, in the film formation allowable region A, the fine particles directly collide with the exposed surface of the substrate 26. At this time, since the fine particles collide with a sufficient speed, they adhere to the surface of the substrate 26 and are deposited to form a film-like piezoelectric material layer 27 (see FIG. 11B). On the other hand, in the film formation inhibition zone B, when the fine particles in the carrier gas collide with the buffer liquid layer 70, the speed is reduced, and when the fine particles reach the surface of the substrate 26, the velocity energy necessary to adhere to the film is lost. Therefore, it does not become a film.
Thereafter, in the individual electrode forming step, as shown in FIG. 11C, the individual electrode 30 is formed on the upper surface of the piezoelectric material layer 27, and the conductive path 54 of the flat cable 53 is connected to the individual electrode 30. .

According to the present embodiment, when the fine particles in the carrier gas collide with the buffer liquid layer 70 provided in the film formation inhibition region B, the velocity of the fine particles is reduced, and the velocity energy necessary to adhere to the film shape Film is not formed.
Further, since the buffer liquid layer 70 is made of a non-volatile liquid, it is difficult to volatilize even when the pressure is reduced in the film forming chamber 42 in the piezoelectric layer forming process.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) According to the present invention, in the first and second embodiments, the correspondence relationship between the surface hardness of the substrate and the different hardness material layer may be reversed. That is, the substrate is made of a material having a surface hardness that does not easily form a film when the carrier gas containing fine particles of the piezoelectric material is sprayed, such as alumina or zirconia having a high surface hardness. As the hardness material layer, a material having a surface hardness that is likely to form a film due to adhesion of the fine particles, for example, stainless steel, gold, nickel, or the like having a surface hardness lower than that of the substrate is used. In the film formation region forming step, the different hardness material layer is provided in a region corresponding to the film formation allowable region on the substrate surface, and the substrate surface is exposed in the film formation inhibition region. Even with such a configuration, it is possible to selectively form a piezoelectric material layer in a film forming allowable region.

(2) In each of the above embodiments, a piezoelectric actuator used as an ink jet head has been shown. However, the present invention, for example, a piezoelectric actuator other than an ink jet head such as a micropump for transferring a liquid using a piezoelectric material layer and its manufacture. The method can also be applied.

Sectional drawing which cut | disconnected the inkjet head of 1st Embodiment of this invention along the longitudinal direction of a pressure chamber. Sectional view of the inkjet head cut along the short side of the pressure chamber Top view of inkjet head Plan view when a different hardness material layer is formed on the substrate (A) Cross-sectional view when a different hardness material layer is formed on the substrate (B) Cross-sectional view when a carrier gas containing fine particles of the piezoelectric material is sprayed on the substrate (C) Individually on the upper surface of the piezoelectric material layer Sectional view when electrodes are formed Schematic diagram of deposition system Sectional drawing which cut | disconnected the inkjet head of 2nd Embodiment along the longitudinal direction of a pressure chamber. Top view of inkjet head Sectional drawing which cut | disconnected the inkjet head of 3rd Embodiment along the longitudinal direction of a pressure chamber. (A) Cross section when resist is patterned on substrate (B) Cross section when etching is performed (C) Cross section when resist is removed from substrate (D) Fine particles of piezoelectric material are included on substrate Sectional view when spraying the carrier gas (A) Sectional view when the buffer liquid layer is coated on the substrate in the fourth embodiment (B) Sectional view when carrier gas containing fine particles of piezoelectric material is sprayed on the substrate (C) Piezoelectric material layer Sectional view when individual electrodes are formed on the top surface

Explanation of symbols

10, 50, 60 ... Inkjet head (piezoelectric actuator)
DESCRIPTION OF SYMBOLS 12 ... Pressure chamber 13 ... Ink flow path formation body 14,51, 61 ... Actuator unit 22 ... Common ink chamber 24 ... Nozzle 26, 62 ... Substrate 27 ... Piezoelectric material layer 28, 52 ... Different hardness material layer 30 ... Individual electrode 31 ... Lead part 70 ... Buffer liquid layer A ... Deposition allowable range B ... Deposition inhibition

Claims (26)

A method for manufacturing a piezoelectric actuator, wherein a piezoelectric material layer is formed by spraying a carrier gas containing fine particles of a piezoelectric material on a substrate surface and attaching the fine particles.
A film forming allowable region in which the fine particles of the piezoelectric material in the carrier gas are attached to the surface of the substrate in advance to form a film and a film formation inhibiting region in which the fine particles are prevented from attaching to form a film are provided, Thereafter, a carrier gas containing the fine particles is sprayed onto the surface of the substrate to form a piezoelectric material layer in the film formation allowable region. A method of manufacturing a piezoelectric actuator, wherein a piezoelectric material layer is formed by spraying a carrier gas containing fine particles of a piezoelectric material on one surface of the substrate and attaching the fine particles,
A film formation allowable region where the fine particles adhere until they form a film when the carrier gas is sprayed on one surface of the substrate, and a film formation inhibition region where the fine particles adhere and become a film are inhibited. A film forming region forming step to be provided;
A piezoelectric layer forming step in which a carrier gas containing the fine particles is sprayed on one surface of the substrate that has undergone the film formation region forming step to form a piezoelectric material layer in the film formation allowable region;
A method for manufacturing a piezoelectric actuator, comprising: 3. The piezoelectric actuator according to claim 2, wherein in the film formation region forming step, the film formation allowable region and the film formation inhibition region are separately formed by making the surface hardness different from each other. Production method. The ratio of the Vickers hardness Hv (b) in the film formation allowable range to the Vickers hardness Hv (p) of the fine particles is in the range of 0.39 ≦ Hv (p) / Hv (b) ≦ 3.08 And the ratio of the Vickers hardness Hv (b) of the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is less than 0.39 or a value exceeding 3.08. Item 4. A method for manufacturing a piezoelectric actuator according to Item 3. The ratio of the Vickers hardness Hv (b) in the allowable film formation range to the Vickers hardness Hv (p) of the fine particles is in the range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43. And the ratio of the Vickers hardness Hv (b) of the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is less than 0.39 or a value exceeding 3.08. Item 4. A method for manufacturing a piezoelectric actuator according to Item 3. The ratio of the Vickers hardness Hv (b) in the allowable film formation range to the Vickers hardness Hv (p) of the fine particles is in the range of 0.43 ≦ Hv (p) / Hv (b) ≦ 1.43. And the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the Vickers hardness Hv (p) of the fine particles is less than 0.43 or more than 1.43. Item 4. A method for manufacturing a piezoelectric actuator according to Item 3. The ratio between the Vickers hardness Hv (b) in the film forming allowable range and the compressive fracture strength Gv (p) of the fine particles is 0.10 ≦ {Gv (p) / Hv (b)} × 100 ≦ 3.08 And the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.10 or The method for manufacturing a piezoelectric actuator according to claim 3, wherein {Gv (p) / Hv (b)} × 100> 3.08. The ratio of the Vickers hardness Hv (b) in the film formation allowable range to the compressive fracture strength Gv (p) of the fine particles is 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43. And the ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.10 or The method for manufacturing a piezoelectric actuator according to claim 3, wherein {Gv (p) / Hv (b)} × 100> 3.08. The ratio of the Vickers hardness Hv (b) in the film formation allowable range to the compressive fracture strength Gv (p) of the fine particles is 0.11 ≦ {Gv (p) / Hv (b)} × 100 ≦ 1.43. The ratio of the Vickers hardness Hv (b) in the film formation inhibition region to the compression fracture strength Gv (p) of the fine particles is {Gv (p) / Hv (b)} × 100 <0.11 or The method for manufacturing a piezoelectric actuator according to claim 3, wherein {Gv (p) / Hv (b)} × 100> 1.43. In the film formation region forming step, by patterning and forming a different hardness material layer having a surface hardness different from that of the substrate on one surface of the substrate, a region where the one surface of the substrate serving as the film formation allowable region is exposed; The method for manufacturing a piezoelectric actuator according to claim 3, further comprising: a region on which the different hardness material layer serving as the film formation inhibition region is formed. The method of manufacturing a piezoelectric actuator according to claim 10, wherein the different hardness material layer has an insulating property. 12. The method according to claim 2, further comprising an electrode forming step of forming an individual electrode for applying an electric field to the piezoelectric material layer on the piezoelectric material layer after the piezoelectric layer forming step. The manufacturing method of the piezoelectric actuator of description. After the piezoelectric layer forming step, an electrode forming step for forming an individual electrode for applying an electric field to the piezoelectric material layer on the piezoelectric material layer is provided. In this electrode forming step, the electrode is electrically connected to the individual electrode. 12. The method of manufacturing a piezoelectric actuator according to claim 11, wherein the connected lead portion is formed on the different hardness material layer. In the film formation region forming step, by performing a surface treatment that adjusts the surface roughness of one surface of the substrate, a region having a small surface roughness that is the film formation allowable region and a surface roughness that is the film formation inhibition region. The method for manufacturing a piezoelectric actuator according to claim 2, wherein a region having a large degree is provided. In the film formation region forming step, the fine particles adhere to the film shape by reducing the collision speed of the fine particles of the piezoelectric material in the carrier gas in the region that is the film formation inhibition region on one surface of the substrate. 3. The method of manufacturing a piezoelectric actuator according to claim 2, further comprising a buffer liquid layer that inhibits the buffer liquid layer. The method for manufacturing a piezoelectric actuator according to claim 15, wherein the buffer liquid layer is made of a liquid having non-volatility. The method for manufacturing a piezoelectric actuator according to claim 2, wherein the substrate is made of a conductive material and is used as one electrode for applying an electric field to the piezoelectric material layer. A method of manufacturing an ink jet head, comprising: an ink flow path forming body in which a common ink chamber and a plurality of ink flow paths extending from the common ink chamber to the nozzle through the pressure chamber are formed; and an actuator unit that changes the volume of the pressure chamber. Because
A flow path forming body creating step of creating an ink flow path forming body in which a part of the pressure chamber is opened;
A substrate fixing step of fixing a conductive substrate serving as a common electrode of the actuator unit to the ink flow path forming body, and closing the pressure chamber;
A deposition allowable region that adheres until the fine particles become a film when a carrier gas containing fine particles of piezoelectric material is sprayed on a surface of the conductive substrate opposite to the fixing surface of the ink flow path forming body; A film formation region forming step of providing a film formation inhibition region in which the fine particles are prevented from adhering to form a film;
A piezoelectric layer forming step of spraying a carrier gas containing the fine particles to form a piezoelectric material layer serving as an active layer of the actuator unit in the film formation allowable region;
Forming an individual electrode of the actuator unit on the piezoelectric material layer; and
A method of manufacturing an ink jet head, comprising: A piezoelectric actuator in which a piezoelectric material layer is formed by spraying a carrier gas containing fine particles of a piezoelectric material on one surface of the substrate and attaching the fine particles,
On one surface of the substrate, there are a film formation allowable region in which the fine particles of the piezoelectric material in the carrier gas adhere to form a film and a film formation inhibition region in which the fine particles adhere to form a film and are inhibited. A piezoelectric actuator provided, wherein the piezoelectric material layer is formed in the film formation allowable region. 20. The film formation allowable area and the film formation inhibition area are formed separately by forming a different hardness material layer having a surface hardness different from that of the substrate on one surface of the substrate. The piezoelectric actuator described in 1. 21. The film formation allowable region is formed by exposing a part of one surface of the substrate, and the film formation inhibition region is formed of the different hardness material layer having a hardness higher than that of the substrate. The piezoelectric actuator described in 1. The piezoelectric actuator according to any one of claims 19 to 21, wherein an individual electrode for applying an electric field to the piezoelectric material layer is formed on the piezoelectric material layer. The different hardness material layer is formed in the film formation inhibition region and has an insulating property, and a lead portion that is electrically connected to the individual electrode is formed on the different hardness material layer. The method for manufacturing a piezoelectric actuator according to claim 22. The piezoelectric actuator according to claim 19, wherein the film formation inhibition area is created by increasing the surface roughness of the substrate as compared with the film formation allowable area. The piezoelectric actuator according to any one of claims 19 to 24, wherein the substrate is made of a conductive material and is used as a common electrode for applying an electric field to the piezoelectric material layer. In an ink jet head having an ink flow path forming body in which a common ink chamber and a plurality of ink flow paths from the common ink chamber to the nozzle through the pressure chamber are formed, and an actuator unit that changes the volume of the pressure chamber,
The ink flow path forming body has a pressure chamber opening surface that opens a part of the pressure chamber,
The actuator unit is
A conductive substrate fixed to the pressure chamber opening surface and serving as a common electrode of an actuator unit that closes the pressure chamber;
A film forming allowable area formed on the surface opposite to the surface of the conductive substrate fixed to the ink flow path forming body and adhering until the fine particles form a film when a carrier gas containing fine particles of the piezoelectric material is sprayed. And a film formation inhibition region in which the fine particles are prevented from adhering to form a film,
A piezoelectric material layer serving as an active layer of the actuator unit formed in the film formation allowable region;
An inkjet head, comprising: an individual electrode that is formed in the film formation allowable region and sandwiches the piezoelectric material layer with the conductive substrate.

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