CN101244651A - Method of manufacturing piezoelectric actuator and method of manufacturing liquid transport device - Google Patents

Abstract

A recess is formed on the upper surface of the vibration plate at a position corresponding to the pressure chamber. Next, a low-elasticity material having a lower elastic modulus than the vibration plate is filled in the recess. Then, an aerosol including particles of a piezoelectric material and a carrier gas is sprayed on the upper surface of the vibration plate to form a piezoelectric layer. At this time, the particles of the piezoelectric material do not adhere to the surface of the low-elasticity material filled in the recess, and therefore the piezoelectric layer can be formed only in the region other than the surface of the low-elasticity material. Accordingly, a method of manufacturing a piezoelectric actuator is provided, which can easily prevent a piezoelectric layer from being formed on a surface of a recess when the piezoelectric layer is formed by an aerosol deposition method. The invention also provides a method of manufacturing a liquid delivery device including the piezoelectric actuator.

Description

Method of making piezoelectric actuator and method of making liquid delivery device

Cross References to Related Applications

This application claims priority from Japanese Patent Applications No. 2007-035688 and No. 2007-035689 filed on February 16, 2007, the disclosures of which are incorporated herein by reference in their entirety.

technical field

The present invention relates to methods of making piezoelectric actuators and methods of making liquid delivery devices.

Background technique

In general, as an inkjet head that ejects ink from a nozzle, there is known an inkjet head having a piezoelectric actuator that utilizes the force generated when an electric field acts on a piezoelectric material layer. The generated piezoelectric deformation (piezoelectric strain) applies ejection pressure to the ink.

For example, a piezoelectric actuator of an inkjet head described in Japanese Patent Application Laid-Open No. 2006-96034 has: a vibrating plate made of metal and covering a plurality of pressure chambers formed in a channel unit; a piezoelectric layer on the upper surface of the vibration plate; and a plurality of individual electrodes respectively arranged in regions facing the plurality of pressure chambers on the upper surface of the piezoelectric layer. Then, in this piezoelectric actuator, when a predetermined driving voltage is applied between the individual electrodes on the upper surface of the piezoelectric layer and the vibrating plate as a common electrode located on the lower side of the piezoelectric layer, the piezoelectric layer contracts , and produce bending deformation in the vibrating plate. Then, the volume in the pressure chamber changes with this deformation of the vibrating plate, thereby applying ejection pressure to the ink in the pressure chamber.

In addition, in the piezoelectric actuator of Japanese Patent Application Laid-Open No. 2006-96034, recessed portions (grooves, grooves) are formed in the upper surface of the vibration plate. As the recessed portion, a recessed portion formed in a region facing the pressure chamber and a recessed portion formed in an outer region not facing the pressure chamber are disclosed. Then, the piezoelectric layer is formed by depositing piezoelectric material particles on the entire upper surface of the vibrating plate including the recessed portion by using an aerosol deposition method (AD method) or the like. Then, since it is more difficult for particles to deposit in the recessed portion than in a flat area around the recessed portion, the piezoelectric layer is locally thinned in the region of the vibration plate where the recessed portion is formed. Therefore, in the region where the recessed portion is formed, the thickness of the vibration plate and the piezoelectric layer, that is, the rigidity of the piezoelectric actuator locally becomes low.

When the concave portion of the vibration plate is arranged in the area facing the pressure chamber, the vibration plate can be easily deformed in the area facing the pressure chamber. In other words, it is possible to reduce the drive voltage required to obtain a predetermined amount of deformation (ie, the amount of volume change in the pressure chamber). In addition, when the recessed portions of the vibration plate are each arranged in the region between adjacent pressure chambers, pressure fluctuations (crosstalk) due to propagation of deformation of the vibration plate between adjacent pressure chambers are suppressed. ).

In consideration of reducing the driving voltage by promoting deformation of the vibrating plate in the region facing the pressure chamber, or suppressing crosstalk between adjacent pressure chambers, it is preferable not to deposit a piezoelectric material on the surface of the recessed portion, The rigidity of the piezoelectric actuator is thereby further reduced in the region where the recess is formed. However, in the piezoelectric actuator described in Japanese Patent Application Laid-Open No. 2006-96034, the amount of piezoelectric material deposited in the recessed portion is smaller than that deposited on a flat area other than the recessed portion. The amount of electrical material, but the piezoelectric material is still deposited to some extent in the recessed portion. In addition, although the piezoelectric layer deposited in the recessed portion can be removed by laser or the like, the removal requires high processing accuracy so as not to remove the piezoelectric layer on the desired area, and adding these steps increases manufacturing cost.

Contents of the invention

An object of the present invention is to provide a method of manufacturing a piezoelectric actuator that can easily prevent the formation of a piezoelectric layer in the recessed portions when forming the piezoelectric layer on the surface of the vibrating plate in which the recessed portions are formed by the AD method. A piezoelectric layer is formed on the surface, and an object of the present invention is to provide a method of manufacturing a piezoelectric actuator which can easily remove the piezoelectric layer formed on the surface of the concave portion of the vibrating plate.

According to a first aspect of the present invention, there is provided a method of manufacturing a piezoelectric actuator, the method comprising:

There is provided a base member including a non-interfering portion, the vibrating plate being joined on an engaging surface thereof to cover the non-interfering portion, and a vibrating plate having a stacking surface on which the vibrating plate is stacked on the base member , and the stacking surface is on the side opposite to the bonding surface;

forming a recess at a position corresponding to the non-interfering portion in the stacked surface of the vibrating plate;

filling the recess of the vibrating plate with a low elastic material having an elastic modulus lower than that of the stacked surfaces of the vibrating plates;

Compression is formed by blowing a mist containing piezoelectric material particles and carrier gas onto the stacked surface of the vibrating plate to deposit the piezoelectric material particles on a region of the stacked surface different from the surface of the low-elasticity material filled in the recess. electrical layer; and

A first electrode arranged on one surface of the piezoelectric layer and a second electrode arranged on the other surface of the piezoelectric layer are formed.

According to the first aspect of the present invention, after filling the recessed portion of the vibration plate with a low-elasticity material having a smaller modulus of elasticity than that of the vibration plate, by blowing (spraying) a gas mist including piezoelectric material particles and a carrier gas onto the The vibration plate is made to collide with the vibration plate and the particles are deposited on the vibration plate to form the piezoelectric layer. Here, when the aerosol is sprayed on the surface of the vibrating plate provided with the low-elastic material, it is known that material particles are prevented from adhering to the low-elastic material having a low modulus of elasticity (ie, having a low surface hardness). on the surface (see Japanese Patent Application Laid-Open No. 2005-317952). Therefore, piezoelectric material particles are not deposited on the surface of the low-elasticity material filled in the recessed portion, and the piezoelectric layer 31 is formed only on a region other than the surface of the low-elasticity material 50 . In other words, the formation of the piezoelectric layer on the surface of the recess formed in the vibrating plate can be prevented only by adding a simple step of filling the recess with a low-elasticity material before forming the piezoelectric layer by the AD method.

In the method of manufacturing a piezoelectric actuator according to the present invention, the low-elasticity material may have fluidity.

In this case, since a material having fluidity is used as the low-elasticity material, filling of the low-elasticity material in the recessed portion can be easily performed. In addition, since a recessed portion is previously formed in the vibrating plate and then filled with a low-elasticity material in the recessed portion, the low-elasticity material having fluidity can be placed in a predetermined region where it is desired to prevent formation of a piezoelectric layer.

The method of manufacturing a piezoelectric actuator according to the present invention may further include removing the low-elasticity material after forming the piezoelectric layer. In this way, by removing the low-elastic material in the recessed portion after forming the piezoelectric layer, the rigidity of the piezoelectric actuator is further reduced in the region where the recessed portion is formed in the vibration plate.

The method of manufacturing a piezoelectric actuator according to the present invention may further include performing heat treatment on the piezoelectric layer after forming the piezoelectric layer, and the thermal decomposition temperature of the low-elasticity material may be lower than that used for the piezoelectric layer in the heat treatment temperature.

When the piezoelectric layer is formed by the AD method, particle miniaturization, lattice failure, etc. occur due to collision with the vibrating plate, so what often happens in this state is that the piezoelectric characteristics necessary for deforming the vibrating plate are not obtained . Therefore, in order to improve piezoelectric characteristics, heat treatment (annealing) is generally performed on the piezoelectric layer formed by the AD method. Here, in the present invention, since the thermal decomposition temperature of the low elastic material is lower than that of the piezoelectric layer (annealing temperature), the low elastic material is thermally decomposed and vaporized during heat treatment. That is, the heat treatment of the piezoelectric layer and the removal of the low-elasticity material can be performed simultaneously, and thus the manufacturing steps of the piezoelectric actuator can be reduced.

In the method of manufacturing a piezoelectric actuator according to the present invention, a recess may be formed on the stacked surface of the vibrating plates at a region facing the non-interfering portion. In this way, by forming a recess in the area of the vibration plate facing the non-interfering portion (deformation allowing portion), and further by not allowing the piezoelectric layer to be deposited on the surface of the recessed portion, the vibration plate becomes easy to be placed on the surface of the vibration plate. deformation in the region of the non-interfering portion, whereby the driving voltage can be reduced.

In the method of manufacturing a piezoelectric actuator according to the present invention, the recess may be formed on the stacked surface of the vibrating plate at a region of the peripheral portion facing the non-interfering portion. In this case, the piezoelectric layer is formed in a region where the recessed portion is not formed facing the central portion of the non-interference portion. Therefore, by arranging the first electrode and the second electrode so as to sandwich the piezoelectric layer, the central partial region where the piezoelectric layer is formed becomes a driving region where the piezoelectric layer contracts itself to generate a vibration in the vibrating plate. out of shape. On the other hand, no piezoelectric layer is formed in the area of the peripheral (edge) portion facing the non-interference portion, and this area becomes a driven area that follows the deformation of the vibration plate generated by the driving area in accordance with the Motion deformation.

In the method of manufacturing a piezoelectric actuator according to the present invention, the recess may be formed on the stacked surface of the vibrating plates at a region facing a central portion of the non-interfering portion. In this case, the piezoelectric layer is formed in a region where the recessed portion is not formed in the peripheral edge portion facing the non-interference portion. Therefore, by arranging the first electrode and the second electrode so as to sandwich the piezoelectric layer, the peripheral edge portion region where the piezoelectric layer is formed becomes a driving region where the piezoelectric layer itself shrinks so as to be in the vibrating plate. deformed. On the other hand, the piezoelectric layer is not formed in the region facing the central portion of the non-interfering portion, and this region becomes a driven region that deforms in a driven manner following deformation of the vibration plate generated by the driving region .

In the method of manufacturing a piezoelectric actuator according to the present invention, the base member may have a plurality of individual non-interference portions as non-interference portions and a partition wall separating the plurality of individual non-interference portions; and

The recess may be formed at a region facing the partition wall on the stacked surface of the vibrating plate. Thus, by forming the recessed portion in the region of the vibrating plate facing the partition wall portion and further by not allowing the piezoelectric layer to be deposited on the surface of the recessed portion, deformation of the vibration plate becomes difficult in the two parts separated by the partition wall portion. This deformation allows propagation between parts and suppresses crosstalk.

In the method for manufacturing a piezoelectric actuator according to the present invention, the vibrating plate can be made of a metal material, a predetermined reference potential can be continuously applied to the first electrode, and the reference potential can be selectively applied to the second electrode in conjunction with The reference potential is different from one of predetermined drive potentials, and the method may further include: forming an insulating layer covering the stacked surface after forming the recess in the stacked surface of the vibrating plate said recess of

forming the first electrode at a region not facing the recess on the surface of the insulating layer; and

After the piezoelectric layer is formed on the surface of the insulating layer to cover the first electrode, on the other surface of the piezoelectric layer on the side opposite to the vibrating plate, facing the The second electrode is formed at the region of the first electrode.

When the vibrating plate is made of a metal material, the recessed portion can be easily formed by etching. However, since the piezoelectric material is not deposited on the surface of the recessed portion when the piezoelectric layer is formed, there is concern that, while the surface of the recessed portion remains exposed, the surface of the recessed portion of the conductive vibration plate and the piezoelectric material arranged on the piezoelectric layer A short circuit occurs between the second electrodes on the side of the electrical layer opposite to the vibrating plate. However, in the present invention, since the insulating layer is formed to cover the recessed portion on the stacked surface of the vibration plate, a short circuit between the vibration plate and the second electrode can be reliably prevented. In addition, the first electrode arranged on the surface of the piezoelectric layer on the vibration plate side is insulated from the vibration plate having conductivity by the insulating layer covering the vibration plate. In addition, since the first electrode is covered by the piezoelectric layer, a short circuit between the first electrode and the second electrode is also prevented.

In the method of manufacturing a piezoelectric actuator according to the present invention, the low elastic material may be shaped to have a pellet or rod form. In this case, since the low-elasticity material is a solid material in the form of particles without fluidity, the low-elasticity material can be easily arranged in the recessed portion.

According to a second aspect of the present invention there is provided a method of manufacturing a liquid delivery device, the method comprising:

providing a channel unit in which a liquid channel including a pressure chamber is formed;

providing a vibration plate which is bonded to one surface of the channel unit on its joint surface to cover the pressure chamber, the vibration plate has a stacking surface on which the vibration plate is stacked on the base member, and the stacking surface on the side opposite the joining surface;

forming recesses in the stacked surfaces of the vibrating plates at positions corresponding to the pressure chambers;

filling the recess of the vibrating plate with a low elastic material having a lower modulus of elasticity than the stacked surface of the vibrating plate;

forming the piezoelectric layer by blowing a mist containing piezoelectric material particles and a carrier gas onto the stacked surface of the vibrating plate to deposit the piezoelectric material particles on a region different from the surface of the low-elasticity material filled in the recess;

A piezoelectric actuator is formed by arranging a first electrode on one surface of the piezoelectric layer and a second electrode on the other surface of the piezoelectric layer; and

A piezoelectric actuator is arranged on the one surface of the channel unit.

According to the second aspect of the present invention, the piezoelectric layer is formed in the vibration plate by an aerosol deposition method after filling a low elastic material having a smaller modulus of elasticity than that of the vibration plate in the concave portion of the vibration plate. Here, when the gas mist containing the piezoelectric material particles and the carrier gas is sprayed on the surface of the vibration plate formed with the low elastic material, the piezoelectric material is prevented from being deposited on the surface of the low elastic material. Therefore, it is possible to prevent the piezoelectric layer from being formed on the surface of the recessed portion formed in the vibrating plate only by adding a simple step of filling the recessed portion with a low-elasticity material before forming the piezoelectric layer by the AD method. That is, it is possible to easily manufacture a liquid transport device capable of achieving further reduction in driving voltage and suppressing crosstalk.

In the liquid delivery device according to the present invention, the low elastic material may have fluidity.

In this case, since a material having fluidity is used as the low-elasticity material, filling of the low-elasticity material in the recessed portion can be easily performed. In addition, since a recessed portion is previously formed in the vibrating plate and then filled with a low-elasticity material in the recessed portion, the low-elasticity material having fluidity can be placed in a predetermined region where it is desired to prevent formation of a piezoelectric layer.

According to a third aspect of the present invention, there is provided a method of manufacturing a piezoelectric actuator, the method comprising:

A base member is provided, which includes a non-interfering portion and a vibrating plate bonded to one surface of the base member on its joint surface to cover the non-interfering portion, the vibrating plate having a stacking surface on which the vibrating plate stacked on the base member with the stacking surface on the side opposite the joining surface;

forming a recessed portion at a position corresponding to the non-interfering portion in the stacked surface of the vibrating plate;

filling the recess of the vibrating plate with a filler thermally decomposed at the first temperature;

forming a stack including a vibration plate, a piezoelectric layer, and a filler by forming a piezoelectric layer on a stacked surface of the vibration plate;

heating the stack to a temperature equal to or higher than the first temperature to thermally decompose the filler and remove the filler and the portion of the piezoelectric layer on the surface of the filler; and

A first electrode arranged on one surface of the piezoelectric layer and a second electrode arranged on the other surface of the piezoelectric layer are formed.

According to the third aspect of the present invention, after the filler thermally decomposed at a predetermined temperature (first temperature) is filled in the concave portion of the vibration plate, the piezoelectric layer is formed on the stacked surface of the vibration plate. Then, the stack including the vibrating plate, the piezoelectric layer, and the filler is heated to a predetermined temperature (the thermal decomposition temperature of the filler) or higher. Therefore, the filler filled in the concave portion is thermally decomposed, and the filler is allowed to evaporate, and then the piezoelectric layer covering the filler on the region facing the concave portion is blown off. Therefore, it is possible to easily remove the piezoelectric layer in the region facing the recessed portion.

In the method of manufacturing a piezoelectric actuator according to the present invention, the filler may have fluidity. In this case, since a material having fluidity is used as the filler, filling of the filler in the concave portion can be easily performed. In addition, since a recessed portion is previously formed in the vibrating plate and then filled with a filler in the recessed portion, the filler having fluidity can be placed in a predetermined region where removal of the piezoelectric layer is desired.

In the method of manufacturing a piezoelectric actuator according to the present invention, when removing the filler and the portion of the piezoelectric layer, the stacked body may be heated to a temperature not lower than a second temperature greater than the first temperature, and annealing the piezoelectric layer at the second temperature.

Depending on the method of forming the piezoelectric layer, there may be cases where the necessary piezoelectricity for deforming the vibration plate cannot be obtained due to reasons such as small material particle diameters, presence of lattice failure, etc. in the formed piezoelectric layer. electrical characteristics. In this case, in order to improve piezoelectric characteristics, heat treatment (annealing) of heating the piezoelectric layer to a predetermined annealing temperature (second temperature) is performed. Here, in the present invention, in the step of removing the filler and the piezoelectric layer, the stack including the piezoelectric layer, the vibrating plate, and the filler is heated to an annealing temperature of the piezoelectric layer higher than the thermal decomposition temperature of the filler or higher. Therefore, annealing of the piezoelectric layer and removal of the filler and the piezoelectric layer on the surface of the filler can be performed simultaneously, and thus the manufacturing steps of the piezoelectric actuator can be reduced.

In the method of manufacturing a piezoelectric actuator according to the present invention, a recess may be formed on the stacked surface of the vibrating plates at a region facing the non-interfering portion. In this way, by forming a recessed portion in the region of the vibrating plate facing the non-interfering portion and forming a piezoelectric layer on the vibrating plate, and then removing the piezoelectric layer on the surface of the recessed portion, the vibrating plate becomes easy to operate in the facing deformation in the region of the non-interfering portion, whereby the driving voltage can be reduced.

In the method of manufacturing a piezoelectric actuator according to the present invention, the recess may be formed on the stacked surface of the vibrating plate at a region of the peripheral portion facing the non-interfering portion. In this case, the piezoelectric layer is formed in a region where the recessed portion is not formed facing the central portion of the non-interference portion. Therefore, by arranging the first electrode and the second electrode so as to sandwich the piezoelectric layer, the central partial region where the piezoelectric layer is formed becomes a driving region where the piezoelectric layer contracts itself to generate a vibration in the vibrating plate. out of shape. On the other hand, the piezoelectric layer is removed in the area where the recessed portion is formed in the peripheral edge portion facing the non-interference portion, so this area becomes a driven area that follows the vibrating plate produced by the driving area Deformation deforms in a driven manner.

In the method of manufacturing a piezoelectric actuator according to the present invention, the recess may be formed on the stacked surface of the vibrating plates at a region facing a central portion of the non-interfering portion. In this case, the piezoelectric layer is formed in a region where the recessed portion is not formed in the peripheral portion facing the non-interference portion. Therefore, by arranging the first electrode and the second electrode so as to sandwich the piezoelectric layer, the peripheral edge portion region where the piezoelectric layer is formed becomes a driving region where the piezoelectric layer itself shrinks so as to be in the vibrating plate. deformed. On the other hand, the piezoelectric layer is removed in the area where the recessed portion is formed facing the central portion of the non-interference portion, so this area becomes a driven area that deforms with the vibration plate generated by the driving area Transform in a driven manner.

In the method of manufacturing a piezoelectric actuator according to the present invention, the base member may have a plurality of individual non-interference portions as non-interference portions and a partition wall separating the plurality of individual non-interference portions; and

The recess may be formed at a region facing the partition wall on the stacked surface of the vibrating plate. In this way, by removing the piezoelectric layer on the surface of the recessed portion after forming the recessed portion in the region of the vibrating plate facing the partition wall portion and forming the piezoelectric layer on the vibrating plate, the deformation of the vibrating plate is difficult to be caused by the partition wall. Propagation between the two non-interfering parts that are partly separated, thus suppressing crosstalk.

In the method of manufacturing a piezoelectric actuator according to the present invention, the vibrating plate may be made of a metal material; and

A predetermined reference potential may be continuously applied to the first electrode, and one of the reference potential and a predetermined driving potential different from the reference potential is selectively applied to the second electrode, and the method may further include: An insulating layer is formed after forming the recess in the stack surface of the vibrating plate, the insulating layer covering the recess on the stack surface; The first electrode is formed at a region of the insulating layer; and after the piezoelectric layer is formed on the surface of the insulating layer to cover the first electrode, a The second electrode is formed on a surface on the side at a region facing the first electrode.

When the vibrating plate is made of a metal material, the recessed portion can be easily formed by etching. However, since the piezoelectric layer on the surface of the recessed portion is removed in the removing step, there is concern that, while the surface of the recessed portion remains exposed, the piezoelectric layer on the surface of the recessed portion of the conductive vibrating plate and the piezoelectric layer disposed on it is feared. A short circuit occurs between the second electrodes on the side opposite to the vibrating plate. However, in the present invention, since the insulating layer is formed to cover the recessed portion on the stacked surface of the vibration plate, a short circuit between the vibration plate and the second electrode can be reliably prevented. In addition, the first electrode arranged on the surface of the piezoelectric layer on the vibration plate side is insulated from the vibration plate having conductivity by the insulating layer covering the vibration plate. In addition, since the first electrode is covered by the piezoelectric layer, a short circuit between the first electrode and the second electrode is also prevented.

In the method of manufacturing a piezoelectric actuator according to the present invention, it may further include: heating the stacked body to a temperature lower than a second temperature higher than the first temperature, and at the first temperature annealing the piezoelectric layer at a second temperature to remove the filler; then heating the stack to a third temperature higher than the second temperature to anneal the piezoelectric layer again. In this case, the removal treatment and the annealing treatment can be performed at a temperature suitable for removing the filler and a temperature suitable for annealing, respectively, so the degree of freedom in adjusting the temperature can be increased.

According to a fourth aspect of the present invention there is provided a method of manufacturing a fluid delivery device, the method comprising:

providing a channel unit in which a liquid channel including a pressure chamber is formed;

providing a vibrating plate bonded to one surface of the channel unit on its bonding surface to cover the pressure chamber, the vibrating plate having a stacking surface on a side opposite to the bonding surface;

forming recesses in the stacked surfaces of the vibrating plates at positions corresponding to the pressure chambers;

filling the recess of the vibrating plate with a filler thermally decomposed at the first temperature;

forming a stack including a vibration plate, a piezoelectric layer, and a filler by forming a piezoelectric layer on a stacked surface of the vibration plate;

heating the stacked body to a temperature not less than the first temperature to thermally decompose the filler and remove the filler and the portion of the piezoelectric layer on the surface of the filler;

A piezoelectric actuator is formed by arranging a first electrode on one surface of the piezoelectric layer and a second electrode on the other surface of the piezoelectric layer; and

A piezoelectric actuator is arranged on the one surface of the channel unit.

According to the fourth aspect of the present invention, a filler thermally decomposed at a predetermined temperature or higher is filled in the concave portion of the vibrating plate, and then the piezoelectric layer is formed on the stacked surface of the vibrating plate. Then, the stacked body including the vibrating plate, the piezoelectric layer, and the filler is heated to the thermal decomposition temperature of the filler or higher. Therefore, the filler filled in the recessed portion is thermally decomposed, and the piezoelectric layer on the surface of the recessed portion is blown off, whereby the piezoelectric layer on the region facing the recessed portion can be easily removed. That is, it is possible to easily manufacture a piezoelectric actuator capable of further reducing the drive voltage and suppressing crosstalk.

In the method of manufacturing a liquid delivery device according to the present invention, the filler may have fluidity. In this case, since a material having fluidity is used as the filler, filling of the filler in the concave portion can be easily performed. In addition, since a recessed portion is previously formed in the vibrating plate and then filled with a filler in the recessed portion, the filler having fluidity can be placed in a predetermined region where removal of the piezoelectric layer is desired.

According to the present invention, the piezoelectric layer can be prevented from being formed on the surface of the concave portion formed in the vibrating plate only by adding a simple step of filling the concave portion with a low-elasticity material before forming the piezoelectric layer by the AD method. When a material having fluidity is used as the low-elasticity material, filling of the low-elasticity material in the recessed portion can be easily performed. In addition, since the recessed portion is formed in advance in the vibrating plate and then filled with the low-elasticity material in the recessed portion, the low-elasticity material having fluidity can be placed in a predetermined region where it is desired to prevent formation of the piezoelectric layer.

In addition, according to the present invention, by filling the filler in the concave portion of the vibrating plate, then forming the piezoelectric layer, and then causing the filler to thermally decompose to blow off the piezoelectric layer covering the filler, it is possible to easily remove the The piezoelectric layer in the region of the recessed portion. In addition, when a material having fluidity is used as the filler, filling of the filler in the recessed portion can be easily performed. Also, since a recessed portion is formed in advance in the vibrating plate and then filled with a filler in the recessed portion, it is possible to place a filler having fluidity in a predetermined region where removal of the piezoelectric layer is desired.

Description of drawings

FIG. 1 is a schematic configuration diagram of an inkjet printer according to an embodiment of the present invention.

Fig. 2 is a plan view of an ink jet head.

FIG. 3 is a partially enlarged view of FIG. 2 .

FIG. 4 is a cross-sectional view along line IV-IV in FIG. 3 .

FIG. 5 is a cross-sectional view along line V-V in FIG. 3 .

6A to 6C show a method of manufacturing the inkjet head common to the first and second embodiments, wherein FIG. 6A shows a plate bonding step, FIG. 6B shows an insulating layer forming step, and FIG. 6C shows a common electrode forming step.

7A to 7D show a method of manufacturing an inkjet head according to a first embodiment, wherein FIG. 7A shows a low elastic material filling step, FIG. 7B shows a piezoelectric layer forming step, FIG. 7C shows a heat treatment step, and FIG. 7D shows individual electrodes A forming step and a nozzle plate joining step.

FIG. 8 is a flowchart showing the steps shown in FIGS. 6A to 6D .

Fig. 9 is a flowchart showing the steps shown in Figs. 7A to 7D.

Fig. 10 shows another pattern of the step of filling with low elastic material or filler.

11A to 11D show a method of manufacturing an inkjet head according to a second embodiment, wherein FIG. 11A shows a filling step, FIG. 11B shows a piezoelectric layer forming step, FIG. 11C shows a removing step, and FIG. 11D shows a separate electrode forming step and Nozzle Plate Engagement Step.

Fig. 12 is a flowchart showing the steps shown in Figs. 11A to 11D.

FIG. 13 is a sectional view corresponding to FIG. 5 of an inkjet head of a first modification.

FIG. 14 is a sectional view corresponding to FIG. 5 of an inkjet head of a second modification.

Fig. 15 is a partially enlarged plan view of an ink jet head of a third modification.

Fig. 16 is a sectional view taken along line XV-XV in Fig. 15 .

FIG. 17 is a sectional view corresponding to FIG. 5 of an inkjet head of a fourth modification.

18 is a sectional view corresponding to FIG. 5 of an inkjet head of a fifth modification.

FIG. 19 is a sectional view corresponding to FIG. 5 of an inkjet head of a sixth modification.

Detailed ways

Next, a first embodiment of the present invention will be described. This embodiment is an example of applying the present invention as a liquid delivery device to an inkjet head that ejects ink onto recording paper for recording.

First, the inkjet printer 100 having the inkjet head 2 of this embodiment will be briefly described. As shown in Figure 1, the inkjet printer 100 has a carriage 1, a serial inkjet head 2 and a feed roller 3, the carriage 1 can move in the left and right direction in Figure 1, and the serial inkjet head 2 is located at On the carriage 1 and eject ink onto the recording paper P, the feed roller 3 feeds the recording paper P in the forward direction in FIG. 1 .

During movement in the left-right direction in FIG. 1 integrally with the carriage 1 , the inkjet head 2 injects ink supplied from an ink cartridge (not shown) through the nozzles 20 (see FIGS. 2 to 5 ) arranged on the lower side thereof. onto the recording paper P. In addition, the feed roller 3 feeds the recording paper P in the forward direction in FIG. 1 . Then, the inkjet printer 100 prints desired images, letters, etc. on the recording paper P by feeding the recording paper P in the forward direction by the feed roller 3 while ejecting ink onto the recording paper P through the nozzles 20 of the inkjet head 2. on the recording paper P.

Next, the inkjet head 2 will be described in detail. As shown in Figures 2 to 5, the inkjet head 2 has a channel unit 4 and a piezoelectric actuator 5, the channel unit 4 is formed with an ink channel comprising a nozzle 20 and a pressure chamber 14, and the piezoelectric actuator 5 pairs The ink in the pressure chamber 14 applies pressure to eject the ink through the nozzles 20 of the channel unit 4 .

First, the channel unit 4 will be explained. As shown in FIGS. 4 and 5 , the channel unit 4 has a cavity plate 10 , a base plate 11 , a header plate 12 and a nozzle plate 13 , and these four plates 10 to 13 are bonded together in a stacked layer. Of these plates, the cavity plate 10, the base plate 11, and the header plate 12 are plates made of stainless steel, and in the three plates 10 to 13, ink passages to be described below can be easily formed by etching such as Manifold 17, pressure chamber 14. In addition, the nozzles 13 are formed of, for example, a high-molecular synthetic resin material such as polyimide, and are attached to the lower surface of the header plate 12 .

As shown in FIGS. 2 to 5 , among the four plates 10 to 13 , the cavity plate 10 at the uppermost position has a plurality of pressure chambers arranged along a flat surface and formed by holes penetrating the plate 10 vertically. Room 14. Then, as shown in FIG. 5, each adjacent pair of pressure chambers 14 is separated by a partition wall 10a. In addition, the plurality of pressure chambers 14 are arranged in two rows in a zigzag form in the sheet feeding direction (up-and-down direction in FIG. 2 ). Then, the plurality of pressure chambers 14 are respectively covered from the upper side and the lower side by the vibration plate 30 and the base plate 11 which will be described below. In addition, each pressure chamber 14 is formed in a substantially elliptical shape that is long in the scanning direction (left-right direction in FIG. 2 ) in plan view.

As shown in FIGS. 3 and 4 , communication holes 15 , 16 are formed in the substrate 11 at positions respectively overlapping both ends of each pressure chamber 14 in plan view. In addition, in the header plate 12 , two headers 17 extending in the sheet feeding direction are formed to overlap portions on the communication hole 15 side of the pressure chambers 14 arranged in two rows in plan view. These two headers 17 communicate with ink supply holes 18 formed in a vibrating plate 30 to be described below, and ink is supplied to the headers 17 from an ink tank (not shown) via the ink supply holes 18 . Also, a plurality of communication holes 19 respectively communicating with the plurality of communication holes 16 are formed in the header plate 12 at positions on the side opposite to the header 17 overlapping the ends of the plurality of pressure chambers 14 in plan view. place.

In addition, the plurality of nozzles 20 are formed in the nozzle plate 13 at positions overlapping with the plurality of communication holes 19 in plan view, respectively. As shown in FIG. 2 , the plurality of nozzles 20 are arranged to overlap respectively the ends of the plurality of pressure chambers 14 arranged in two rows in the sheet feeding direction on the side opposite to the header 17 . In other words, the plurality of nozzles 20 are arranged in two rows in a zigzag form respectively corresponding to the plurality of pressure chambers 14 .

Then, as shown in FIG. 4 , each of the manifolds 17 communicates with one of the pressure chambers 14 via one of the communication holes 15, and each of the pressure chambers 14 communicates with each of the pressure chambers 14 via the communication holes 16, 19. One of the nozzles 20 communicates. In this way, a plurality of individual ink channels 21 each extending from one header 17 to one nozzle 20 via one pressure chamber 14 are formed in the channel unit 4 .

Next, the piezoelectric actuator 5 will be described. As shown in FIGS. 2 to 5 , the piezoelectric actuator 5 has: a vibrating plate 30 arranged on the upper surface of the cavity plate 10 so as to cover the plurality of pressure chambers 14 ; an insulating layer 37 , the The insulating layer 37 covers the upper surface (stack surface) of the vibration plate 30; the piezoelectric layer 31 is arranged on the upper surface of the vibration plate 30 covered by the insulating layer 37; the common electrode 34 (first electrode), The common electrode 34 is arranged on the lower surface of the piezoelectric layer 31 (between the insulating layer 37 and the piezoelectric layer 31); and the plurality of individual electrodes 32 (second electrodes) are arranged on the upper surface of the piezoelectric layer 31 .

The vibration plate 30 is a metal plate having a substantially rectangular shape in plan view, and is composed of, for example, an iron alloy such as stainless steel, a copper alloy, a nickel alloy, a titanium alloy, or the like. As shown in FIGS. 4 and 5 , in a state where the vibration plate 30 is disposed on the upper surface of the cavity plate 10 to cover the plurality of pressure chambers 14 , the lower surface (joint surface) of the vibration plate 30 is bonded to the cavity plate. 10 of the partition wall portion 10a. It is to be noted that the cavity plate 10 to which the vibrating plate 30 is joined corresponds to the base member of the present invention, and the pressure chamber 14 formed in the cavity plate 10 corresponds to an acceptable (allowable) deformation portion of the present invention.

In the upper surface of the vibration plate 30 , a plurality of recessed portions (recesses) 40 are formed at positions respectively corresponding to the plurality of pressure chambers 14 . Specifically, each recessed portion 40 is a substantially annular (C-shaped) groove (groove) partly divided in the circumferential direction. Then, in the area facing the peripheral portion of one pressure chamber 14 on the upper surface of the vibration plate 30 , the recessed portion 40 extends along substantially the entire circumference of the pressure chamber except the area facing the communication hole 15 . In addition, as shown in FIG. 3 , the outer peripheral shape of the recessed portion 40 is slightly larger than that of the pressure chamber, and the recessed portion 40 is formed to cover the edge of the corresponding pressure chamber 14 in plan view. That is, the inner portion of the recessed portion 40 is arranged in a region facing the pressure chamber 14 , and the outer portion of the recessed portion 40 is arranged in a region not facing the pressure chamber 14 .

An insulating layer 37 is formed on the entire upper surface of the vibrating plate 30 , and the surfaces of the plurality of recessed portions 40 are covered with the insulating layer 37 . As will be described in detail later, in the manufacturing steps of the piezoelectric actuator 5, the piezoelectric layer 31 is heat-treated after the insulating layer 37 is formed, so an insulating material having a high heat-resistant temperature is used for the insulating layer 37. As such a heat insulating material, for example, a heat insulating ceramic material such as alumina, zirconia, or the like can be used.

The piezoelectric layer 31 is formed of a piezoelectric material mainly composed of lead zirconate titanate (PZT), which is a ferroelectric solid solution of lead titanate and lead zirconate. The piezoelectric layer 31 is formed to cover the plurality of pressure chambers 14 on the upper surface of the vibration plate 30 where the insulating layer 37 is formed. However, the piezoelectric layer 31 is not formed on the surface of the plurality of recessed portions 40 of the vibrating plate 30 . In other words, by forming a plurality of through holes 41 in the piezoelectric layer 31 corresponding to the plurality of recessed portions 40, respectively, a structure is realized in which a plurality of driving portions 38 respectively surrounded by a plurality of through holes 41 are arranged In the area of the central portion facing the plurality of pressure chambers 14 . In addition, each recessed portion 40 is cut in a region facing one end portion of one pressure chamber 14 (the end portion on the communication hole 15 side), and the piezoelectric layer 31 (coupling portion) is formed in the cut recessed portion. part 40 on the surface of this part. That is, the piezoelectric layer 31 has a structure in which a plurality of drive portions 38 respectively corresponding to a plurality of pressure chambers 14 are coupled to each other by a plurality of coupling portions 39 .

The common electrode 34 is arranged on the surface of the insulating layer 37 (ie, the lower surface of the piezoelectric layer 31 ), and is insulated from the upper surface of the conductive vibration plate 30 by the insulating layer 37 . The common electrode 34 is formed of a conductive metal such as gold, copper, silver, palladium, platinum, titanium or the like. The common electrode 34 is formed to face at least all of the plurality of pressure chambers 14 . However, the common electrode 34 is not formed in a region facing the recessed portion 40 of the vibration plate 30 . In addition, as described above, by forming the piezoelectric layer 31 in the region other than the region facing the plurality of recessed portions 40 , the common electrode 34 is completely covered by the piezoelectric layer 31 and is not exposed. In addition, this common electrode 34 is connected to an unillustrated driver IC, and is constantly held at the ground potential as a reference potential by the driver IC.

A plurality of individual electrodes 32 are respectively arranged on the upper surfaces of the plurality of drive portions 38 of the piezoelectric layer 31 . Each individual electrode 32 has a substantially elliptical-shaped main electrode portion 32a slightly smaller in plan view than the pressure chamber 14 and a contact portion 32b extending from one end of the main electrode portion 32a along the upper surface of the piezoelectric layer 31 . The main electrode portion 32 a is arranged on the upper surface of the piezoelectric layer 31 in a region facing the substantially central portion (drive portion 38 ) of one pressure chamber 14 . On the other hand, the contact portion 32b is drawn out along the longitudinal direction of the main electrode portion 32a from the one end portion of the main electrode portion 32a along the longitudinal direction on the upper surface of the coupling portion 39 connected to the driving portion 38, and The contact portion 32 b extends to an area not facing the pressure chamber 14 . In addition, similarly to the common electrode 34, the plurality of individual electrodes 32 are also formed of a conductive material such as gold, copper, silver, palladium, platinum, titanium, or the like.

The contact portions 32b of the plurality of individual electrodes 32 are connected to an unillustrated driver IC through a flexible printed circuit (FPC). Then, the plurality of individual electrodes 32 are configured such that one of a ground potential and a predetermined driving potential different from the ground potential is selectively applied from the driver IC to the plurality of individual electrodes 32 .

Next, the operation of the piezoelectric actuator 5 at the time of ink ejection will be described. When a drive voltage is selectively applied from the driver IC to a plurality of individual electrodes 32, the potential of the main electrode portion 32a of the individual electrode 32 to which the drive voltage is applied and the common potential of the lower side of the piezoelectric layer 31 held at ground potential The potentials of the electrodes 34 become different from each other, so an electric field along the thickness direction is generated in the driving portion 38 of the piezoelectric layer 31 sandwiched between the individual electrodes 32 and the common electrode 34 . Then, when the polarization direction of the piezoelectric layer 31 is the same as the direction of the electric field, the piezoelectric layer 31 extends in the thickness direction as the polarization direction and contracts in the horizontal direction, and, with this contraction of the piezoelectric layer 31 Deformation, a portion of the vibration plate 30 facing one of the pressure chambers 14 is deformed to protrude toward the pressure chamber 14 side (unimorph deformation). At this time, the volume of the pressure chamber 14 is reduced, and thus pressure is applied to the ink therein, whereby ink droplets are ejected through the nozzles 20 communicating with the pressure chamber 14 .

Here, as described above, since a driving portion 38 sandwiched between the common electrode 34 and an individual electrode 32 is arranged on the upper surface of the vibrating plate 30 in a region facing the central portion of a pressure chamber 14, the The region becomes a driving region in which, when a driving potential is applied to the individual electrodes 32 , the driving portion 38 contracts by itself and produces deformation in the vibration plate 30 . On the other hand, the area surrounding the driving area on the upper surface of the vibrating plate 30 (the area facing the peripheral portion of one of the pressure chambers 14) becomes a driven area where the vibrating plate 30 is driven due to the contraction of the driving portion 38. And deform according to the driven mode. Then, in the driven region, a recessed portion 40 is formed in the vibrating plate 30 , and in addition, the piezoelectric layer 31 is not arranged on the surface of the recessed portion 40 . This means that the stiffness of the piezo actuator 5 is locally reduced in this driven region.

Thus, when the rigidity of the piezoelectric actuator 5 is lowered in the driven region, the vibrating plate 30 becomes easily deformed in a region facing one of the pressure chambers 14 when the driving portion 38 contracts in the horizontal direction. In other words, it is possible to reduce the driving voltage (the voltage between the individual electrodes 32 and the common electrode 34 ) required for generating a predetermined or greater deformation in the vibrating plate 30 , thereby reducing the electric power of the piezoelectric actuator 5 consume.

In addition, when the rigidity of the piezoelectric actuator 5 is lowered in the surrounding area of the driving portion 38, when the driving portion 38 facing one of the pressure chambers 14 contracts, the deformation generated in the vibrating plate 30 along with the contraction It becomes difficult to propagate to adjacent pressure chambers 14 . That is, crosstalk between adjacent pressure chambers 14 is suppressed.

Next, the method of manufacturing the inkjet head 2 of this embodiment will be described with reference to FIGS. 6A to 6D , FIGS. 7A to 7D , and FIGS. 8 and 9 . Here, FIGS. 8 and 9 are flowcharts showing steps shown in FIGS. 6A to 6D and FIGS. 7A to 7D , respectively. First, a plurality of recessed portions 40 are formed in regions on the upper surface of the vibration plate 30 that will face peripheral portions of the plurality of pressure chambers 14 when bonded to the cavity plate 10 (recessed portion forming step). Here, in this embodiment, since the vibrating plate 30 is composed of a metal material, the plurality of recessed portions 40 can be easily formed by etching.

On the other hand, holes constituting ink passages such as pressure chambers 14 and manifolds 17 are formed in cavity plate 10 , base plate 11 and manifold plate 12 among the plates constituting channel unit 4 . Since these plates 10 to 12 are composed of a metal material similarly to the vibrating plate 30 , holes constituting the ink passage can be easily formed by etching.

Then, as shown in FIG. 6A , four plates, vibrating plate 30 , cavity plate 10 , base plate 11 , and header plate 12 are stacked in layers and bonded together. In this joining step, the four plates can be joined together by, for example, performing metal diffusion bonding by heating the stacked plates to a predetermined temperature (for example, 1000° C.) or higher while pressing them. Alternatively, the four boards can be bonded together by a ceramic adhesive with high thermal resistance.

Next, as shown in FIG. 6B , on the upper surface of the vibrating plate 30 , an insulating layer 37 is formed to cover the plurality of recessed portions 40 (insulating layer forming step). Here, when an insulating ceramic material such as alumina or zirconia is used, ceramics can be deposited on the upper surface of the vibrating plate 30 by employing an aerosol deposition method (AD method), a sputtering method, a chemical vapor deposition method (CVD method), or the like. material particles to form the insulating layer 37 .

Then, as shown in FIG. 6C , on the surface of the insulating layer 37 , the common electrode 34 is formed to face all of the plurality of pressure chambers 14 (common electrode (first electrode) forming step). However, the common electrode 34 is not formed in a region facing the plurality of recessed portions 40 of the vibration plate 30 . This common electrode 34 can be formed by screen printing, a vapor deposition method, a sputtering method, or the like.

Next, as shown in FIG. 7A , a low-elastic material 50 having fluidity is filled in the recessed portion 40 covered with the insulating layer 37 (low-elastic material filling step). Here, the elastic modulus is much lower than that of the vibrating plate 30 made of metal and the insulating layer 37 (for example, alumina) covering the upper surface of the vibrating plate 30 (about 300 GPa), and thermally decomposed A material whose temperature is much lower than the heat treatment temperature (annealing temperature: 650° C. to 900° C.) of the piezoelectric layer 31 is used as the fluid low elasticity material 50 , which will be described later. For example, an epoxy resin (in an uncured state, a thermal decomposition temperature of about 400°C), a fluorine-containing resin (in an uncured state, a thermal decomposition temperature of about 600°C), or the like can be used.

Here, by using a material having fluidity as the low elastic material 50, the filling operation in the recessed portion 40 can be easily performed. For example, as shown in FIG. 7A , a dispenser 51 may be used to inject the low elastic material 50 into the recessed portion 40 . Alternatively, as shown in FIG. 10 , it is also possible to apply the low-elasticity material 50 on the surface of the insulating layer 37 using a doctor blade 52 or the like, thereby filling the low-elasticity material 50 in the recessed portion 40 .

In addition, by forming the recessed portion 40 in the region corresponding to the pressure chamber 14 on the upper surface of the vibrating plate 30 in advance and filling the recessed portion 40 with the fluid low elastic material 50 , it is possible to use a fluidic low-elasticity material 50 . The elastic material is placed in the recessed portion 40, and the low elastic material can be prevented from flowing out of the predetermined filling area. In addition, the low-elasticity material 50 may be any material as long as it exhibits fluidity at least when filled, and the low-elasticity material 50 does not particularly need to have fluidity after being filled in the recessed portion 40 .

After that, as shown in FIG. 7B , piezoelectric layer 31 is formed by the AD method on the upper surface of vibration plate 30 covered with insulating layer 37 (piezoelectric layer forming step). Specifically, first, piezoelectric material (PZT) particles and carrier gas are mixed by an aerosol generator not shown to generate an aerosol. Then, a gas mist including piezoelectric material particles and carrier gas is sprayed (blown) toward the vibrating plate through a thin film forming nozzle (not shown), and the piezoelectric material particles hit the surface of insulating layer 37 at high speed and are deposited thereon. In addition, as a carrier gas, an inert gas such as helium, argon, or the like may be used, or nitrogen, oxygen, air, or the like may be used.

By the way, since the low elastic material 50 filled in the recessed portion 40 of the vibrating plate 30 is a material having a modulus of elasticity (rigidity) lower than that of the vibrating plate 30 and the insulating layer 37, the insulating layer 37 in the vibrating plate 30 The area of the recessed portion filled with the low elastic material 50 on the covered upper surface has a lower surface hardness than the other areas. Here, the present inventors found that when a mist including piezoelectric material particles and a carrier gas is sprayed on the vibrating plate 30, particles are prevented from being deposited on areas having In the region of lower modulus of elasticity (surface hardness) (see Japanese Patent Application Laid-Open No. 2005-317952).

Therefore, when the gas mist is sprayed on the upper surface of the vibrating plate 30 after the low elastic material 50 is filled in the concave portion 40 of the vibrating plate 30, as shown in FIG. on the surface of the low-elastic material 50 in the recessed portion 40 , and the piezoelectric layer 31 is formed only on an area other than the surface of the low-elastic material 50 . That is, the piezoelectric layer 31 (drive portion 38 ) is formed on the upper surface of the vibrating plate 30 on a region surrounded by the recessed portion 40 and facing the central portion of the pressure chamber 14 while the piezoelectric layer 31 is not formed. On the area of the peripheral edge portion facing the pressure chamber 14 where the recessed portion 40 is formed. In addition, as described above, since the common electrode 34 is not formed on the region facing the recessed portion 40 , the piezoelectric layer 31 is formed to completely cover the common electrode 34 .

By the way, when the piezoelectric layer 31 is formed by the AD method, particle miniaturization, lattice failure, etc. occur when the vibrating plate 30 is hit, so in this state, it is not possible to obtain the necessary force for deforming the vibrating plate 30. Piezoelectric properties. Therefore, in order to crystal-grow piezoelectric material particles and recover lattice failure in the crystal to improve piezoelectric characteristics, the stack including the piezoelectric layer 31, the vibrating plate 30, and the plates 10 to 12 is heated to a predetermined annealing temperature, by This heat treatment (annealing) is performed on the piezoelectric layer 31 (heat treatment step).

From the perspective of improving the piezoelectric characteristics of the piezoelectric material, the higher the annealing temperature, the better, but when the annealing temperature is too high, it helps to diffuse the (metal) elements included in the vibrating plate made of metal, and these elements Goes over the insulating layer 37 and reaches the piezoelectric layer 31 . Then, the piezoelectric characteristics of the piezoelectric layer 31 decrease due to this element diffusion. Therefore, the annealing temperature is set to a temperature capable of suppressing diffusion of elements included in the vibration plate 30 to the piezoelectric layer 31 . Specifically, the annealing temperature is set between 650°C and 900°C.

Here, the thermal decomposition temperature of the low elastic material 50 filled in the recessed portion 40 of the vibrating plate 30 is lower than the aforementioned annealing temperature. Therefore, when the stacked body including the piezoelectric layer 31, the vibrating plate 30, and the plates 10 to 12 is heated to 650° C. to 900° C. for heat treatment on the piezoelectric layer 31, the low elastic material 50 heats up as shown in FIG. 7C. Decomposes and evaporates, thus removing the low elastic material 50 in the recessed portion 40 (removing step).

After that, as shown in FIG. 7D , a plurality of individual electrodes 32 are formed on the upper surface of the plurality of drive portions 38 of the piezoelectric layer 31 facing the plurality of pressure chambers 14 and the common electrodes 34 (individual electrodes (second electrodes) ) forming step). The plurality of individual electrodes 32 may be formed by screen printing, a vapor deposition method, a sputtering method, or the like.

Finally, after forming a plurality of nozzles 20 in the nozzle plate 13 made of synthetic resin by laser processing or the like, the nozzle plate 13 is bonded to the lower surface of the header plate 12 by an adhesive or the like.

In addition, similarly to the other three plates 10 to 12 constituting the passage unit 4, the nozzle plate 13 may be formed of a metallic material such as stainless steel. In this case, the heat-resistant temperature of the nozzle plate 13 is higher than the annealing temperature of the piezoelectric layer 31, so the nozzle plate 13 can be bonded to the header plate 12 before the piezoelectric layer forming step. For example, in the plate joining step shown in FIG. 6A , the plates 10 to 12 and the vibrating plate 30 and the nozzle plate 13 may be joined together at one time.

According to the method of manufacturing the inkjet head 2 as described above, the following effects are obtained. When the gas mist is sprayed on the upper surface of the vibrating plate 30 after the low elastic material 50 is filled in the recessed portion 40 formed in the vibrating plate 30 , the piezoelectric material is not deposited in the recessed portion 40 filled in the recessed portion 40 . on the surface of the elastic material 50 , and the piezoelectric material 31 is formed only in a region other than the surface of the low-elastic material 50 . That is, only by adding a simple step of filling the low-elasticity material 50 in the recessed portion 40 before forming the piezoelectric layer 31 by the AD method, it is possible to prevent the surface of the recessed portion 40 formed in the vibrating plate 30 from A piezoelectric layer 31 is formed thereon. In addition, when a material having fluidity is used as the low elastic material 50, filling in the recessed portion 40 can be easily performed. In addition, since the recessed portion 40 is formed in advance in the vibrating plate 30 and the low-elasticity material 50 is filled in the recessed portion 40, the low-elasticity material 50 can be placed in a predetermined region where it is desired to prevent the piezoelectric layer 31 from being formed. .

In addition, since the low elastic material 50 in the recessed portion 40 is removed after the piezoelectric layer 31 is formed, the rigidity of the entire piezoelectric actuator 5 in the region where the recessed portion 40 is formed can be further reduced. Therefore, the vibration plate 30 becomes easier to deform in the region facing the pressure chamber 14, and the driving voltage can be further reduced. In addition, crosstalk between adjacent pressure chambers 14 can be further suppressed. Moreover, by thermally decomposing the low-elasticity material 50 during the heat treatment (annealing) of the piezoelectric layer 31, the removal of the low-elasticity material 50 can be performed simultaneously with the annealing of the piezoelectric layer 31, and thus the manufacturing of the piezoelectric actuator 5 can be reduced. step.

Since the insulating layer 37 is formed to cover the plurality of recessed portions 40 on the upper surface of the vibration plate 30 , the upper surface of the vibration plate 30 is not exposed in the plurality of recessed portions 40 . Therefore, occurrence of a short circuit between the conductive vibration plate 30 and the individual electrodes 32 to which the driving voltage is applied is reliably prevented. In addition, the common electrode 34 on the lower side of the piezoelectric layer 31 is insulated from the conductive vibration plate 30 by the insulating layer 37 . In addition, since the common electrode 34 is covered by the piezoelectric layer 31 and is not exposed, a short circuit between the common electrode 34 and the individual electrodes 32 is also prevented.

second embodiment

Next, a second embodiment of the present invention will be described. This embodiment is also an example of applying the present invention as a liquid delivery device to an inkjet head that ejects ink onto recording paper for recording. The same parts as those in the method of manufacturing the liquid delivery device according to the first embodiment will be assigned the same reference numerals, and descriptions thereof will be omitted.

The steps up to the step of forming the common electrode 34 to face all the pressure chambers 14 on the surface of the insulating layer 37 as shown in FIG. 6C are the same as those in the manufacturing steps of the first embodiment. It is to be noted that FIG. 12 is a flowchart representing the steps shown in FIGS. 11A to 11D . After the common electrode 34 is formed, as shown in FIG. 11A , a filler 150 having fluidity is filled in the recessed portion 40 covered with the insulating layer 37 (filling step). Here, a material having a thermal decomposition temperature much lower than the heat treatment temperature (annealing temperature: 600°C to 900°C) of the piezoelectric layer 31 is used as the fluid filler 150, which will be described below. For example, an epoxy resin (in an uncured state, a thermal decomposition temperature of about 400° C.), a fluorine-containing resin (in an uncured state, a thermal decomposition temperature of about 600° C.), or the like can be used.

Here, by using a material having fluidity as the low elastic material 50, the filling operation in the recessed portion 40 is easily performed. For example, as shown in FIG. 11A , a dispenser 51 may be used to inject a low elastic material 50 into the recessed portion 40 . Alternatively, as shown in FIG. 10 , it is also possible to apply the low elastic material 50 on the surface of the insulating layer 37 using a doctor blade 52 or the like to fill the low elastic material 50 in the recessed portion 40 .

In addition, by forming the recessed portion 40 in advance on the upper surface of the vibrating plate 30 in a region corresponding to the pressure chamber 14 and filling the recessed portion 40 with the fluid low-elasticity material 50 , the low-elasticity having fluidity can be The material is seated in the recessed portion 40, and the low elastic material 150 can be prevented from flowing out of the predetermined filling area. In addition, the filler 150 may be any material as long as it exhibits fluidity at least when filled, and the filler does not particularly need to have fluidity after being filled in the concave portion 40 .

Thereafter, as shown in FIG. surface (piezoelectric layer forming step). Here, the piezoelectric layer 31 can be formed by an aerosol deposition (AD) method, a sputtering method, a chemical vapor deposition (CVD) method, a hydrothermal synthesis method, or the like.

Incidentally, in the case where miniaturization of particles, lattice failure, etc. occur in the piezoelectric layer 31 when the piezoelectric layer 31 is formed by the AD method or the like, it is not possible to obtain the desired effect for deforming the vibrating plate 30 in this state. required piezoelectric properties. Therefore, in this case, in order to grow the particle crystal of the piezoelectric material and restore the lattice failure in the crystal to improve the piezoelectric characteristics, the stacked body including the piezoelectric layer 31, the vibrating plate 30, and the plates 10 to 12 is heated to a predetermined annealing temperature or higher, whereby heat treatment (annealing) is performed on the piezoelectric layer 31 (heat treatment step).

It should be pointed out that from the perspective of improving the piezoelectric characteristics of a single piezoelectric material, the higher the annealing temperature, the better, but when the annealing temperature is too high, it will help the element diffusion included in the vibrating plate made of metal, And these elements pass over the insulating layer 37 and reach the piezoelectric layer 31 . Then, the piezoelectric characteristics of the piezoelectric layer 31 decrease due to this element diffusion. Therefore, the annealing temperature is set to a temperature capable of suppressing diffusion of elements included in the vibration plate 30 to the piezoelectric layer 31 . Specifically, the annealing temperature is set between 650°C and 900°C.

Here, the thermal decomposition temperature of the filler 150 filled in the concave portion 40 of the vibrating plate 30 is lower than the aforementioned annealing temperature of the piezoelectric layer 31 . Therefore, when the stacked body 60 including the piezoelectric layer 31 , the vibrating plate 30 , and the plates 10 to 12 is heated to 650° C. to 900° C. for annealing on the piezoelectric layer 31 , the filler 150 thermally decomposes and the filler 150 thus evaporated. Then, by allowing the filler 150 to evaporate, as shown in FIG. 11C , the piezoelectric layer 31 covering the filler in the region facing the recessed portion 40 is blown off and removed (removing step). Here, since the thermal expansion coefficient of the filler 150 is greater than that of the piezoelectric layer 31 and the filler 150 greatly expands as the stack 60 is heated, a portion of the piezoelectric layer 31 covering the filler 150 is cracked. When the filler 150 is evaporated by further heating the stack 60 , the pressure in the region of the recess 40 covered by the piezoelectric layer 31 increases rapidly and the portion of the piezoelectric layer 31 covering the recess 40 is blown away. Accordingly, the piezoelectric layers 31 remaining in the regions surrounded by the recessed portions 40 facing the central portion of the pressure chamber 14 become the drive portions 38 , respectively. Here, in the removing step, the remaining piezoelectric layer 31 that has not been blown off may be removed by an adhesive tape or the like.

Thereafter, similarly to the first embodiment, a plurality of individual electrodes 32 are formed on the upper surface of the plurality of driving portions 38 of the piezoelectric layer 31 facing the plurality of pressure chambers 14 and the common electrode 34 (individual electrodes (second electrode) forming step). The plurality of individual electrodes 32 can be formed by screen printing, a vapor deposition method, a sputtering method, or the like.

Finally, after forming a plurality of nozzles 20 in the nozzle plate 13 made of synthetic resin by laser processing or the like, the nozzle plate 13 is bonded to the lower surface of the header plate 12 by an adhesive or the like.

In addition, similarly to the other three plates 10 to 12 constituting the passage unit 4, the nozzle plate 13 may be formed of a metallic material such as stainless steel. In this case, the heat-resistant temperature of the nozzle plate 13 is higher than the annealing temperature of the piezoelectric layer 31, so the nozzle plate 13 can be bonded to the header plate 12 before the piezoelectric layer forming step. For example, in the plate joining step shown in FIG. 6A , the plates 10 to 12 and the vibrating plate 30 and the nozzle plate 13 may be joined together at one time.

With the method of manufacturing the inkjet head 2 according to the second embodiment described above, the following effects are obtained. After filling the filler 150 in the concave portion 40 of the vibrating plate 30 and forming the piezoelectric layer 31 on the upper surface of the vibrating plate 30 , the stacked body 60 including the vibrating plate 30 , the piezoelectric layer 31 and the filler 150 will be Heating to the thermal decomposition temperature of the filler 150 or higher. Accordingly, the filler 150 filled in the concave portion 40 is thermally decomposed and the filler 150 is vaporized, and the piezoelectric layer 31 covering the filler 150 is blown off. Therefore, the piezoelectric layer 31 in the region facing the recessed portion 40 can be easily removed. Therefore, the piezoelectric actuator 5 capable of further reducing the drive voltage and suppressing crosstalk can be easily manufactured.

If a filler whose thermal decomposition temperature is lower than the annealing temperature of the piezoelectric layer 31 is used as the filler 150, the filler 150 and the piezoelectric layer 31 on its surface can be removed while the piezoelectric layer 31 is annealed, so that The manufacturing steps of the piezoelectric actuator 5 are reduced. In addition, although the annealing of the piezoelectric layer 31 is combined with (also used for) thermal decomposition treatment of the filler 150 in the above embodiment, these treatments may be performed independently. For example, when the thermal decomposition temperature of the filler 150 is much lower than the annealing temperature of the piezoelectric layer 31, the thermal decomposition treatment may be performed at a temperature higher than the thermal decomposition temperature of the filler 150 and lower than the annealing temperature of the piezoelectric layer 31. , followed by annealing at high annealing temperatures. That is, heat treatment such as thermal decomposition treatment, annealing, and the like can be performed independently in two or more stages.

In addition, according to the methods of manufacturing the inkjet head 2 according to the first and second embodiments described above, since the insulating layer 37 is formed to cover the plurality of recessed portions 40 on the upper surface of the vibrating plate 30, the upper surface of the vibrating plate 30 Not exposed in the plurality of recessed portions 40 . Therefore, occurrence of a short circuit between the conductive vibration plate 30 and the individual electrodes 32 to which the driving voltage is applied is reliably prevented. In addition, the common electrode 34 located below the piezoelectric layer 31 is insulated from the conductive vibration plate 30 by the insulating layer 37 . In addition, since the common electrode 34 is covered by the piezoelectric layer 31 and is not exposed, occurrence of a short circuit between the common electrode 34 and the individual electrodes 32 is also prevented.

Modifications in which various changes are made to the first and second embodiments are described next. However, portions having the same structures as in the above embodiments are given the same reference numerals, and descriptions thereof are appropriately omitted.

first variant

The area where the recessed portion is formed on the vibrating plate in the first and second embodiments is not limited to the area facing the peripheral edge portion of the pressure chamber.

For example, as shown in FIG. 13 , each of the recessed portions 40A may be formed on the upper surface of the vibrating plate 30A from an area facing the peripheral portion of the pressure chamber 14 across the partition wall portion 10 a to facing the adjacent one. The area of the peripheral portion of the pressure chamber 14 . In this case, when the piezoelectric material particles are deposited by the AD method after the low-elasticity material is filled in the recessed portion 40A, no piezoelectric material will be formed on the region facing the peripheral portion of the pressure chamber 14 and the partition wall portion 10a. piezoelectric layer 31A. Alternatively, after filling the filler 150 in the concave portion 40A to form the piezoelectric layer 31A, the peripheral edge portion and the portion facing the pressure chamber 14 can be removed by heating to the thermal decomposition temperature of the filler or higher. The piezoelectric layer 31A is on the region of the partition wall portion 10a. Therefore, the rigidity of the piezoelectric actuator in the region (driven region) facing the peripheral portion of the pressure chamber is reduced, whereby the driving voltage can be reduced. In addition to this, the rigidity of the piezoelectric actuator in the region facing the partition wall portion 10a is also reduced, whereby deformation of the vibration plate 30A can be more effectively suppressed in two pressure chambers divided by one partition wall portion 10a. Propagation between chambers 14 (crosstalk).

second variant

The recessed portion does not have to be formed in the region facing the pressure chamber on the upper surface of the vibration plate. For example, when it is necessary to give more priority to suppressing crosstalk than lowering the drive voltage, as shown in FIG. Crosstalk has the greatest influence, and the piezoelectric layer 31 is not formed on the surface of the recessed portion 40B.

third variant

In the first and second embodiments, the driving portions of the piezoelectric layers are respectively arranged in regions facing the central portions of the pressure chambers, and these regions become the driving regions. However, when the position of the driving portion (driving area) is different, the position of the driven area deformed in a driven manner along with the deformation of the driving portion is also different, so the position where the recessed portion should be formed inevitably changes.

For example, as shown in FIGS. 15 and 16 , when an annular driving portion 38C as part of the piezoelectric layer 31C is formed on the upper surface of the vibrating plate 30C in a region facing the peripheral portion of the pressure chamber 14 and the annular individual electrodes 32C are arranged When on the upper surface of the driving portion 38C, the area facing the peripheral portion of the pressure chamber 14 becomes the driving area, and the area facing the central portion of the pressure chamber 14 becomes the driven area. In manufacturing such a piezoelectric actuator, first, the recessed portion 40C is formed on the upper surface of the vibrating plate 30C in the driven area facing the central portion of the pressure chamber 14 . Then, by filling the low-elasticity material in the recessed portion 40C and depositing piezoelectric material particles on the upper surface of the vibrating plate 30C by the AD method, it is possible to form only in the driving region facing the peripheral portion of the pressure chamber 14 Piezoelectric layer 31C (drive portion 38C). Alternatively, the piezoelectric layer 31C on the region facing the central portion of the pressure chamber 14 is removed by filling the filler in the concave portion 40C, then forming the piezoelectric layer 31C, and then evaporating the filler 150 by thermal decomposition, The piezoelectric layer 31C (drive portion 38C) may be formed on a drive region facing the peripheral portion of the pressure chamber 14 .

fourth variant

As shown in FIG. 17 , by constantly maintaining the vibration plate 30 made of metal at the ground potential, it is possible to use the upper surface of the vibration plate 30 as a common electrode (first electrode) facing the plurality of individual electrodes 32 . In this case, the step of separately forming the common electrode is no longer necessary, and the structure of the piezoelectric actuator also becomes simple. It is to be noted that, in the fourth modification, unlike the first and second embodiments, it is of course not necessary to cover the upper surface of the vibration plate 30 as the common electrode with the insulating layer 37 . However, since piezoelectric material particles are not deposited on the surface of the recessed portion 40 , the conductive portion of the recessed portion 40 is exposed, and there is concern that a short circuit occurs between the surface of the recessed portion 40 and the individual electrode 32 . Therefore, in order to prevent such a short circuit from occurring, only the surface of the recessed portion 40 in the upper surface of the vibration plate 30 may be covered with an insulating layer.

fifth variant

As shown in FIG. 18, a common electrode 34 constantly kept at a ground potential (reference potential) may be arranged on the upper surface of the piezoelectric layer 31, and a separate electrode of one potential of the ground potential and the drive potential is selectively applied. The electrode 32 may be formed on the surface of the insulating layer 37 and disposed on the lower surface of the piezoelectric layer 31 (between the piezoelectric layer 31 and the insulating layer 37 ).

sixth variant

In the first embodiment, as the low-elasticity material filled in the concave portion of the vibrating plate, a material having a thermal decomposition temperature higher than the heat treatment temperature of the piezoelectric layer can also be used. In this case, as shown in FIG. 19 , the low elastic material 50 remains on the recessed portion 40 even after the piezoelectric layer 31 is heat-treated. Therefore, the rigidity of the piezoelectric actuator becomes higher to some extent in the region where the recessed portion is formed, compared to the case where the low elastic material 50 is removed from the recessed portion 40 as in the above-described embodiment. However, compared with the mode in which the piezoelectric layer 31 is not locally formed on the upper surface of the flat vibration plate having no concave portion, the rigidity of the piezoelectric actuator is reduced by the amount of thickness reduction of the vibration plate 30 having high rigidity. .

seventh variant

In the second variant, it is not always necessary to anneal the piezoelectric layer. Depending on the method of forming the piezoelectric layer, desired piezoelectric characteristics can be ensured and thus annealing is no longer necessary. In addition, the piezoelectric layer can also be formed by bonding a piezoelectric sheet obtained by burning a green sheet made of a piezoelectric material to the vibration plate, and in this case it is not necessary to perform heat treatment after bonding to the vibration plate. In addition, in terms of other manufacturing steps, it is preferable in some cases to perform the step of removing the filler separately from the annealing.

Therefore, regardless of whether the piezoelectric layer is annealed, a step of heating the stack including the piezoelectric layer, the vibrating plate, and the filler to the thermal decomposition temperature of the filler or higher is also performed separately to remove the filler and piezoelectric layer on its surface.

It is to be noted that the vibrating plate does not have to be the metal plate in the first and second embodiments described above, and one formed of a material other than metal (for example, a ceramic material such as alumina and zirconia, silicon, etc.) may also be used. The vibrating plate, as long as it has rigidity capable of performing unimorph deformation with the contraction of the driving part to a certain extent. In this case, the most preferable method of forming the recessed portion 40 in the vibrating plate is ultrasonic machining. In addition, the low-elasticity material or the filler has the fluidity in the first and second embodiments described above, but the low-elasticity material and the filler do not always have to have fluidity. For example, a solid low-elasticity material or filler in the form of pellets or rods can be filled in the concave portion of the vibrating plate, and then the low-elasticity material can be cured in the concave portion by, for example, heating, after which the AD method can be used in the A piezoelectric layer is formed on the surface of the vibrating plate where the concave portion is formed. Here, the reason for curing the low-elasticity material or filler is to prevent the low-elasticity material or filler from being ejected due to impact when material particles of the piezoelectric layer collide with the low-elasticity material or filler at high speed in the AD method. Therefore, in the case of forming the piezoelectric layer by a method other than the AD method, curing of the filler can be omitted without fear that the filler is given an excessive impact.

In the foregoing, as an embodiment of the present invention, description has been made using an example in which the present invention is applied to a piezoelectric actuator of an inkjet head that applies ejection pressure to ink in a pressure chamber, and the subject matter to which the present invention is applied Not limited to this. For example, the present invention can be applied as a liquid transfer device for transferring a liquid (such as a chemical solution or a biochemical solution) in a micro total analysis system (μTAS), a device for transferring a liquid (such as a solvent or a chemical solution) in a micro chemical system. Piezoelectric actuators for liquid delivery actuators such as liquid delivery devices.

In addition, the subject matter to which the present invention is applied is not limited to an actuator for applying pressure to a liquid such as ink. Specifically, the present invention can also be applied to piezoelectric actuators for applications other than liquid transportation, such as allowing the vibration plate to deform in the deformation allowing portion of the base member and pressing and driving by the deformation portion of the vibration plate Actuators for various types of objects.

Claims (23)

1. A method of manufacturing a piezoelectric actuator, the method comprising: There is provided a base member including a non-interfering portion, the vibrating plate being joined on an engaging surface thereof to cover the non-interfering portion, and a vibrating plate having a stacking surface on which the vibrating plate is stacked on the base member , and the stacking surface is on the side opposite to the bonding surface; forming a recess at a position corresponding to the non-interfering portion in the stacked surface of the vibrating plate; filling the recess of the vibrating plate with a low elastic material having an elastic modulus lower than that of the stacked surfaces of the vibrating plates; Compression is formed by blowing a mist containing piezoelectric material particles and carrier gas onto the stacked surface of the vibrating plate to deposit the piezoelectric material particles on a region of the stacked surface different from the surface of the low-elasticity material filled in the recess. electrical layer; and A first electrode arranged on one surface of the piezoelectric layer and a second electrode arranged on the other surface of the piezoelectric layer are formed. 2. The method of manufacturing a piezoelectric actuator according to claim 1, wherein said low-elasticity material has fluidity. 3. The method of manufacturing a piezoelectric actuator according to claim 2, further comprising removing the low-elasticity material after forming the piezoelectric layer. 4. The method for manufacturing a piezoelectric actuator according to claim 3, further comprising performing heat treatment on the piezoelectric layer after forming the piezoelectric layer, wherein the thermal decomposition temperature of the low-elasticity material is lower than that of The heat treatment temperature for the piezoelectric layer in this heat treatment is low. 5. The method of manufacturing a piezoelectric actuator according to claim 2, wherein said recess is formed on said stacked surface of said vibrating plate at a region facing said non-interfering portion. 6. The method of manufacturing a piezoelectric actuator according to claim 5, wherein said recess is formed on said stacked surface of said vibrating plate at a region facing a peripheral portion of said non-interfering portion. 7. The method of manufacturing a piezoelectric actuator according to claim 5, wherein said recess is formed on said stacked surface of said vibrating plate at a region facing a central portion of said non-interfering portion. 8. The method of manufacturing a piezoelectric actuator according to claim 2, wherein said base member has a plurality of individual non-interference portions as said non-interference portions and separates said plurality of individual non-interference portions the dividing wall; and The recess is formed on the stacking surface of the vibrating plate at a region facing the partition wall. 9. The method for manufacturing a piezoelectric actuator according to claim 2, wherein said vibrating plate is made of a metal material, a predetermined reference potential is continuously applied to said first electrode, and a predetermined reference potential is selectively applied to said second electrode. the reference potential and one of predetermined driving potentials different from the reference potential, and The method also includes: forming an insulating layer after forming the recess in the stack surface of the vibrating plate, the insulating layer covering the recess on the stack surface; forming the first electrode at a region not facing the recess on the surface of the insulating layer; and After the piezoelectric layer is formed on the surface of the insulating layer to cover the first electrode, on the other surface of the piezoelectric layer on the side opposite to the vibrating plate, facing the The second electrode is formed at the region of the first electrode. 10. The method of manufacturing a piezoelectric actuator according to claim 1, wherein said low elastic material is shaped to have a pellet or rod form. 11. A method of making a liquid delivery device comprising: providing a channel unit in which a liquid channel including a pressure chamber is formed; providing a vibration plate which is bonded to one surface of the channel unit on its joint surface to cover the pressure chamber, the vibration plate has a stacking surface on which the vibration plate is stacked on the base member, and the stacking surface on the side opposite the joining surface; forming recesses in the stacked surfaces of the vibrating plates at positions corresponding to the pressure chambers; filling the recess of the vibrating plate with a low elastic material having a lower modulus of elasticity than the stacked surface of the vibrating plate; forming the piezoelectric layer by blowing a mist containing piezoelectric material particles and a carrier gas onto the stacked surface of the vibrating plate to deposit the piezoelectric material particles on a region different from the surface of the low-elasticity material filled in the recess; A piezoelectric actuator is formed by arranging a first electrode on one surface of the piezoelectric layer and a second electrode on the other surface of the piezoelectric layer; and A piezoelectric actuator is arranged on the one surface of the channel unit. 12. The method of manufacturing a fluid delivery device according to claim 10, wherein said low elastic material has fluidity. 13. A method of manufacturing a piezoelectric actuator comprising: A base member is provided, which includes a non-interfering portion and a vibrating plate bonded to one surface of the base member on its joint surface to cover the non-interfering portion, the vibrating plate having a stacking surface on which the vibrating plate stacked on the base member with the stacking surface on the side opposite the joining surface; forming a recessed portion at a position corresponding to the non-interfering portion in the stacked surface of the vibrating plate; filling the recess of the vibrating plate with a filler thermally decomposed at the first temperature; forming a stack including a vibration plate, a piezoelectric layer, and a filler by forming a piezoelectric layer on a stacked surface of the vibration plate; heating the stack to a temperature equal to or higher than the first temperature to thermally decompose the filler and remove the filler and the portion of the piezoelectric layer on the surface of the filler; and A first electrode arranged on one surface of the piezoelectric layer and a second electrode arranged on the other surface of the piezoelectric layer are formed. 14. The method of manufacturing a piezoelectric actuator according to claim 13, wherein the filler has fluidity. 15. The method of manufacturing a piezoelectric actuator according to claim 14, wherein when removing the filler and the portion of the piezoelectric layer, the stacked body is heated to a temperature not lower than a second temperature, The second temperature is greater than the first temperature, and the piezoelectric layer is annealed at the second temperature. 16. The method of manufacturing a piezoelectric actuator according to claim 14, wherein said recess is formed on said stacked surface of said vibrating plate at a region facing said non-interfering portion. 17. The method of manufacturing a piezoelectric actuator according to claim 16, wherein said recess is formed on said stacked surface of said vibrating plate at a region facing a peripheral portion of said non-interfering portion. 18. The method of manufacturing a piezoelectric actuator according to claim 16, wherein said recess is formed on said stacked surface of said vibrating plate at a region facing a central portion of said non-interfering portion. 19. The method of manufacturing a piezoelectric actuator according to claim 14, wherein said base member has a plurality of individual non-interference portions as said non-interference portions and separates said plurality of individual non-interference portions the dividing wall; and The recess is formed on the stacking surface of the vibrating plate at a region facing the partition wall. 20. The method of manufacturing a piezoelectric actuator according to claim 2, wherein: the vibrating plate is composed of a metal material; and continuously applying a predetermined reference potential to the first electrode, and selectively applying one of the reference potential and a predetermined driving potential different from the reference potential to the second electrode, and The method also includes: forming an insulating layer after forming the recess in the stack surface of the vibrating plate, the insulating layer covering the recess on the stack surface; forming the first electrode at a region not facing the recessed portion on the surface of the insulating layer; and After the piezoelectric layer is formed on the surface of the insulating layer to cover the first electrode, on the surface of the piezoelectric layer on the side opposite to the vibrating plate, facing the first electrode, The second electrode is formed at the region of the first electrode. 21. The method of manufacturing a piezoelectric actuator according to claim 14, further comprising: heating the stacked body to a temperature lower than a second temperature higher than the first temperature, and at annealing the piezoelectric layer at the second temperature to remove the filler; then heating the stack to a third temperature higher than the second temperature to anneal the piezoelectric layer again. 22. A method of making a liquid delivery device, the method comprising: providing a channel unit in which a liquid channel including a pressure chamber is formed; providing a vibrating plate bonded to one surface of the channel unit on its bonding surface to cover the pressure chamber, the vibrating plate having a stacking surface on a side opposite to the bonding surface; forming recesses in the stacked surfaces of the vibrating plates at positions corresponding to the pressure chambers; filling the recess of the vibrating plate with a filler thermally decomposed at the first temperature; forming a stack including a vibration plate, a piezoelectric layer, and a filler by forming a piezoelectric layer on a stacked surface of the vibration plate; heating the stacked body to a temperature not less than the first temperature to thermally decompose the filler and remove the filler and the portion of the piezoelectric layer on the surface of the filler; A piezoelectric actuator is formed by arranging a first electrode on one surface of the piezoelectric layer and a second electrode on the other surface of the piezoelectric layer; and A piezoelectric actuator is arranged on the one surface of the channel unit. 23. The method of manufacturing a fluid delivery device of claim 22, wherein the filler has fluidity.

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