JP2008227144A - Piezoelectric actuator, its production process, and liquid injection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric actuator including a piezoelectric element with a wiring connected with an upper electrode electrically insulated with a lower electrode. <P>SOLUTION: The piezoelectric actuator 100 comprises a base 10, a lower electrode 20 provided on the base 10, a piezoelectric substance layer 30 provided on the lower electrode 20, an upper electrode 40 provided on the piezoelectric substance layer 30, a wiring part 70 connected electrically with the upper electrode 40, and an insulating layer 60 for electrically insulating the lower electrode 20 and the wiring part 70 so as to provide a piezoelectric element 50 with the lower electrode 20, the piezoelectric substance layer 30 and the upper electrode 40. The insulating layer 60 is provided so as to cover at least partially the side surface of the lower electrode 20 and the piezoelectric substance layer 30. The wiring part 70 is formed on the insulating layer 60. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piezoelectric actuator, a manufacturing method thereof, and a liquid jet head.

  A piezoelectric actuator generally includes a piezoelectric element having a structure in which a piezoelectric body made of an inorganic oxide is sandwiched between two electrodes. The piezoelectric actuator is an element that performs electromechanical conversion by applying a voltage between electrodes of a piezoelectric element to cause deformation of the piezoelectric body. The voltage applied between the electrodes of the piezoelectric element is generally several volts to several tens of volts, and is larger than the voltage applied between the electrodes in other devices such as a memory. Therefore, in the piezoelectric element, electrical insulation between electrodes and wirings is more important than other devices.

Piezoelectric actuators are required to be miniaturized, and the arrangement of piezoelectric elements inside the piezoelectric actuators is being investigated. If it is not necessary to reduce the size, the upper and lower electrodes are formed to be shifted in order to insulate the wiring between the lower electrode and the upper electrode, as in the piezoelectric / electrostrictive actuator described in JP-A-8-116684. For example, sufficient space was available for wiring. If the piezoelectric elements are arranged densely, there is no room for shifting the upper and lower electrodes, and the portion where the wiring of the upper electrode is arranged is limited. For example, as in the piezoelectric actuator described in Japanese Patent Laid-Open No. 2007-006620, in the portion where the wiring of the upper electrode is performed, the lower electrode is disposed inside the piezoelectric body to ensure insulation between the lower electrode and the wiring To be done.
JP-A-8-116684 JP 2007-006620 A

  However, when the lower electrode is disposed inside the piezoelectric body, a portion of the piezoelectric body that is not sandwiched between the upper and lower electrodes is generated, which may cause damage to the element. It is necessary to remove this portion of the piezoelectric body also in terms of arranging the piezoelectric elements at high density. In order to further increase the density while removing unnecessary piezoelectric bodies, it is necessary to properly arrange the upper and lower electrodes and wiring in a limited space and to insulate them appropriately. . When performing such a compact arrangement, it is particularly difficult to secure a distance between the wiring of the upper electrode and the lower electrode.

  An object of the present invention is to provide a piezoelectric actuator including a piezoelectric element in which a wiring connected to an upper electrode is electrically insulated from the lower electrode, a manufacturing method thereof, and a liquid ejecting head including such a piezoelectric actuator. .

The piezoelectric actuator according to the present invention is
A substrate;
A lower electrode provided above the substrate;
A piezoelectric layer provided above the lower electrode;
An upper electrode provided above the piezoelectric layer;
A wiring portion electrically connected to the upper electrode;
An insulating layer for electrically insulating the lower electrode and the wiring portion;
Including
A piezoelectric element is constituted by the lower electrode, the piezoelectric layer and the upper electrode,
The insulating layer is provided so as to cover the lower electrode and at least a part of a side surface of the piezoelectric layer,
The wiring part is formed above the insulating layer.

  Such a piezoelectric actuator has a piezoelectric element in which the wiring connected to the upper electrode is electrically and reliably insulated from the lower electrode.

  In the present invention, when a specific B layer (hereinafter referred to as “B layer”) provided above a specific A layer (hereinafter referred to as “A layer”) is referred to as “B” directly on the A layer. This includes the case where the layer is provided and the case where the B layer is provided on the A layer via another layer.

  In the piezoelectric actuator according to the present invention, the insulating layer may be provided on an outer periphery of the piezoelectric element.

  In the piezoelectric actuator according to the present invention, the insulating layer may be provided on a part of the outer periphery of the piezoelectric element.

  In the piezoelectric actuator according to the present invention, the insulating layer may be made of an oxide containing silicon.

  In the piezoelectric actuator according to the present invention, the lower electrode includes a plurality of layers, and an outer periphery of a part of the plurality of layers is provided so as to be inside an outer periphery of a lower surface of the piezoelectric layer. be able to.

  In the piezoelectric actuator according to the present invention, a barrier layer may be further provided so as to cover at least a part of the side surface of the piezoelectric layer.

  In the piezoelectric actuator according to the present invention, a bank having a side surface facing the side surface of the piezoelectric element may be further provided on the base, and the insulating layer may be provided between the bank and the piezoelectric element. .

  A liquid jet head according to the present invention includes the above-described piezoelectric actuator. The liquid ejecting head according to the invention may include the piezoelectric actuator, a pressure chamber substrate below the piezoelectric actuator, and a nozzle plate below the pressure chamber substrate.

  Since such a liquid ejecting head includes a piezoelectric actuator having piezoelectric elements arranged at high density, when used for ink jet printing, the printed matter has high definition.

A method for manufacturing a piezoelectric actuator according to the present invention includes:
A step of sequentially laminating a lower electrode, a piezoelectric layer, and an upper electrode above the substrate;
Patterning the upper electrode, the piezoelectric layer, and the lower electrode to form a piezoelectric element;
Forming an insulating layer so as to cover at least a part of the side surface of the lower electrode and the piezoelectric layer;
Forming a wiring portion electrically connected to the upper electrode above the insulating layer;
including.

  The process of forming the said insulating layer of the manufacturing method of the piezoelectric actuator concerning this invention can be performed by a spin on glass (SOG) method.

  The process of forming the said insulating layer of the manufacturing method of the piezoelectric actuator concerning this invention can be performed by the inkjet method.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the following embodiment demonstrates an example of this invention.

1. Piezoelectric Actuator FIG. 1 is a cross-sectional view schematically showing a piezoelectric actuator according to this embodiment. FIG. 2 is a plan view schematically showing the piezoelectric actuator 100 according to the present embodiment. A cross section taken along line AA in FIG. 2 corresponds to FIG. In FIG. 2, the insulating layer 60 is depicted with the end portion shown by a broken line and seen through. FIG. 3 is a cross-sectional view schematically showing a modification of the piezoelectric actuator 100 according to the present embodiment. FIG. 4 is a plan view schematically showing a modification of the piezoelectric actuator 100 according to the present embodiment. A cross section taken along line AA in FIG. 4 corresponds to FIG.

  The piezoelectric actuator 100 includes a base body 10, a piezoelectric element 50, an insulating layer 60, and a wiring part 70.

  The base 10 is a member that performs mechanical output when the piezoelectric actuator 100 is operated. For example, the base 10 may include a diaphragm, may be a movable part of the liquid ejecting head, and may form a wall such as a pressure generation chamber. The base body 10 can bend and vibrate by the operation of the piezoelectric layer 30. It is desirable that the material of the base 10 includes a material having high rigidity and mechanical strength. The thickness of the substrate 10 is optimally selected according to the elastic modulus of the material used. As a material of the substrate 10, for example, an inorganic oxide such as zirconium oxide, silicon nitride, or silicon oxide, or an alloy such as stainless steel can be preferably used. The substrate 10 may have a laminated structure of two or more substances.

  The piezoelectric element 50 includes a lower electrode 20, a piezoelectric layer 30, and an upper electrode 40.

  The lower electrode 20 is formed above the base body 10. The lower electrode 20 does not necessarily have the same shape as the lower part of the piezoelectric layer 30. For example, as shown in FIG. 2, when there is a similar piezoelectric element next to the piezoelectric element 50, it can be electrically connected so as to be a common lower electrode with the lower electrode of the piezoelectric element. The lower electrode 20 is electrically connected to an external circuit (not shown). The thickness of the lower electrode 20 is arbitrary as long as the deformation of the piezoelectric layer 30 can be transmitted to the base 10. The thickness of the lower electrode 20 can be set to, for example, 100 nm to 300 nm. The lower electrode 20 is paired with the upper electrode 40, sandwiches the piezoelectric layer 30, and functions as one electrode of the piezoelectric element 50. When the piezoelectric layer 30 is formed on the upper surface of the lower electrode 20, the lower electrode 20 has a function of making the crystal orientation and grain size of the piezoelectric layer 30 suitable for piezoelectric operation. The material of the lower electrode 20 is not particularly limited as long as it is a conductive material that satisfies this function. For example, the material of the lower electrode 20 includes various metals such as nickel, iridium and platinum, conductive oxides thereof (for example, iridium oxide), composite oxide of strontium and ruthenium, composite oxide of lanthanum and nickel, etc. Can be used. Further, the lower electrode 20 may be a single layer of the exemplified materials or a structure in which a plurality of materials are laminated.

The piezoelectric layer 30 is formed on the lower electrode 20. The thickness of the piezoelectric layer 30 can be 500 nm to 1500 nm. The piezoelectric layer 30 expands and contracts when an electric field is applied by the lower electrode 20 and the upper electrode 40, thereby causing the base 10 to bend or vibrate. A piezoelectric material can be used for the piezoelectric layer 30. As a material of the piezoelectric layer 30, a perovskite oxide (A includes Pb and B includes Zr and Ti) represented by a general formula ABO ₃ is preferably used. For example, lead zirconate titanate (PZT) and lead zirconate titanate niobate (PZTN) are preferable as the material of the piezoelectric layer 30 because of their good piezoelectric performance.

  The upper electrode 40 is formed on the piezoelectric layer 40. The upper electrode 40 is paired with the lower electrode 20 and functions as one electrode of the piezoelectric element 50. The thickness of the upper electrode 40 is not limited as long as it does not adversely affect the operation of the piezoelectric actuator 100. The thickness of the upper electrode 40 can be set to, for example, 50 nm to 200 nm. The material of the upper electrode 40 is not particularly limited as long as it is a conductive material. The material of the upper electrode 40 includes various metals such as nickel, iridium, gold and platinum, conductive oxides thereof (for example, iridium oxide, etc.), composite oxide of strontium and ruthenium, composite oxide of lanthanum and nickel, etc. Can be used. Further, the upper electrode 40 may be a single layer of the exemplified materials or a structure in which a plurality of materials are stacked.

  The insulating layer 60 is provided so as to cover the lower electrode 20 and at least a part of the side surface of the piezoelectric layer 30. The insulating layer 60 may cover the entire thickness direction of the side surface of the piezoelectric layer 30. The insulating layer 60 may cover a part of the lower side in the thickness direction of the side surface of the piezoelectric layer 30. In the example of FIGS. 1 and 2, the insulating layer 60 is provided so as to cover the entire piezoelectric actuator 100 except for the wiring portion 70, the upper electrode 40, and a part of the piezoelectric layer 30. The insulating layer 60 may be provided on a part of the piezoelectric actuator 100. For example, the insulating layer 60 may be provided only in a region below the wiring portion 70 as shown in FIGS. The insulating layer 60 preferably covers the piezoelectric layer 30 on the side surface of the piezoelectric layer 30 so as to be 80 nm or more upward from the boundary with the lower electrode 20. The upper surface of the insulating layer 60 may not be horizontal as shown in FIG. The insulating layer 60 is provided between the lower electrode 20 and the wiring part 70 in order to ensure insulation. As a material of the insulating layer 60, an inorganic material or an organic material can be used. Among them, a substance having a small Young's modulus is preferable. For example, the material of the insulating layer 60 is preferably silicon oxide or various polymers.

  The wiring part 70 is provided above the insulating layer 60. The wiring part 70 may be provided in contact with the piezoelectric layer 30. The wiring part 70 is electrically connected to the upper electrode 10. The wiring part 70 is electrically insulated from the lower electrode 20 by at least the insulating layer 60. The wiring unit 70 electrically connects the upper electrode 40 and an external circuit (not shown). Various materials such as nickel, iridium, gold, and platinum can be used as the material of the wiring portion 70, and a single layer structure or a multilayer structure may be used.

  The piezoelectric element 50 of the present embodiment may have a flush side surface formed so that the side surface of the lower electrode 20, the side surface of the piezoelectric layer 30, and the side surface of the upper electrode 40 are continuous. Forming such a flush side surface on the piezoelectric element 50 may be advantageous for arranging the piezoelectric elements 50 at a high density. For example, in FIG. 1 and FIG. 2, in the portion forming the short side of the rectangular piezoelectric element 50, the side surfaces of the lower electrode 20, the piezoelectric layer 30 and the upper electrode 40 are formed in the same plane. The flush side surface is formed by simultaneously etching the upper electrode 40, the piezoelectric layer 30, and the lower electrode 20, for example. Even when the wiring part 70 is provided on the flush side surface, the insulating layer 60 can reliably insulate between the lower electrode 20 and the wiring part 70.

  The piezoelectric actuator 100 according to the present embodiment has the following characteristics.

  In the piezoelectric actuator 100, the lower electrode 20 and the wiring part 70 are sufficiently separated by the insulating layer 60. Therefore, the piezoelectric actuator 100 is an element that corresponds to the increase in density of the piezoelectric element 50 and that is electrically reliably insulated between the lower electrode 20 and the wiring part 70. Further, since the insulating layer 60 of the piezoelectric actuator 100 is made of a material having a low Young's modulus such as silicon oxide, the operation of the element is hardly hindered. Further, it is preferable that the insulating layer 60 is smaller so that the operation of the element is not hindered.

2. Piezoelectric Actuator Manufacturing Method FIGS. 5 to 8 are cross-sectional views schematically showing the manufacturing process of the piezoelectric actuator 100 of FIG.

  The method for manufacturing the piezoelectric actuator 100 according to the present embodiment includes a step of forming a piezoelectric laminate, a step of forming a piezoelectric element, a step of forming an insulating layer, and a step of forming a wiring portion.

  As shown in FIG. 5, first, the base 10 is prepared, and the lower electrode 20 a is formed on the base 10. The lower electrode 20a can be formed by a method such as sputtering, vacuum deposition, or CVD. Next, the piezoelectric layer 30a is laminated on the lower electrode 20a. The piezoelectric layer 30a is formed by a sol-gel method, a CVD method, or the like. In the sol-gel method, a desired film thickness may be obtained by repeating a series of operations of raw material solution coating, preheating, and crystallization annealing several times. Next, the upper electrode 40a is laminated on the piezoelectric layer 30a. The upper electrode 40a can be formed by a method such as sputtering, vacuum deposition, or CVD. Here, for example, when the material of the piezoelectric layer 30a is PZT, the piezoelectric laminate 50a is formed by performing crystallization annealing at about 700 ° C. in an oxygen atmosphere.

  Next, as shown in FIG. 5, a patterned mask layer 95 is formed on the piezoelectric laminate. Next, the upper electrode 40a, the piezoelectric layer 30a, and the lower electrode 20a are etched, and as shown in FIG. 6, the upper electrode 40, the piezoelectric layer 30, and the lower electrode 20 are etched as necessary, thereby the piezoelectric element 50. Get. In this step, the masking and patterning steps may be repeated a plurality of times. Further, this step can be performed using a composite oxide of lanthanum and nickel as a so-called hard mask instead of the mask layer 95, or can be performed by combining both. As an etching method, a dry etching method, a wet etching method, or a combination thereof can be used. For example, the upper electrode 40 can be satisfactorily patterned by dry etching using a mixed gas of halogen gas and argon gas and the piezoelectric layer 30 using a mixed gas of halogen gas and chlorofluorocarbon gas. After the patterning, the mask layer 95 is removed by ashing, wet etching, or the like.

  Next, as shown in FIG. 7, an insulating layer 60 is formed so as to cover the lower electrode 20 and at least a part of the piezoelectric layer 30. This step can be performed by a known method such as a spin-on-glass (SOG) method or an inkjet method. According to the SOG method, it is easy to form the insulating layer 60 over the entire piezoelectric actuator 100 as in the example of FIG. 7 and 8 show an example in which this step is performed by a spin-on-glass method. As shown in FIG. 7, an insulating layer 60a is formed by applying and heat-treating an SOG material by spin coating. In the illustrated example, the insulating layer 60 a is applied so as to cover the side surface of the upper electrode 40, but may cover the upper electrode 40. Thereafter, a known etch back method is performed to form the insulating layer 60 so as to cover the lower electrode 20 and part of the piezoelectric layer 30 and expose the upper electrode 40 as shown in FIG. it can. Thereafter, the SOG layer (insulating layer 60a) other than the periphery of the capacitor may be removed using a mask having a size at least 80 nm larger than the size of the lower electrode. In this case, since the size of the insulating layer 60 in contact with the periphery of the capacitor is reduced while ensuring the insulation, the characteristics of the piezoelectric element are improved.

  Next, as shown in FIGS. 1 and 2, a wiring portion 70 electrically connected to the upper electrode 40 is provided above the insulating layer 60. The wiring part 70 can be formed, for example, by a method such as sputtering, vacuum deposition, CVD, electroless plating, and patterning.

  In this way, the piezoelectric actuator 100 is manufactured. However, the manufacturing method according to the present embodiment can include a step of appropriately forming another member or a step of performing a surface treatment between the steps.

  As described above, according to the method for manufacturing the piezoelectric actuator 100 of the present embodiment, the piezoelectric actuator 100 can be obtained by a simple process.

3. Modified Examples The piezoelectric actuator 100 according to the present embodiment can be variously modified. Hereinafter, modified examples will be described, but description of components that are substantially the same as the configuration of the piezoelectric actuator 100 described above will be omitted.

  9 to 11 are cross-sectional views schematically showing modified examples of the piezoelectric actuator 100 according to the present embodiment. As shown in FIGS. 9 to 11, the lower electrode 20 is composed of a plurality of layers, and is provided so that the outer periphery of a part of the plurality of layers is inside the outer periphery of the lower surface of the piezoelectric layer 30. be able to. For example, as shown in FIG. 9, the lower electrode 20 and the wiring 70 can be further separated by undercutting the lower electrode upper layer 24 of the lower electrode 20. In this case, as shown in FIG. 11, for example, if the thickness of the lower electrode to be undercut is about 100 nm, the insulating layer only needs to cover the periphery of the lower electrode, and it is not necessary to cover the side wall of the piezoelectric element.

  In such a lower electrode 20, for example, the material of the lower electrode lower layer 22 of the lower electrode 20 is a metal such as nickel, iridium, gold, platinum, and the material of the lower electrode upper layer 24 of the lower electrode 20 is a composite of lanthanum and nickel. After the lower electrode 20 is patterned using an oxide, the lower electrode upper layer 24 can be selectively etched. This modification has the effect of controlling the crystallinity of the piezoelectric layer 30 by the lower electrode 20 and further separating the distance between the lower electrode 20 and the wiring 70.

  12 and 13 are cross-sectional views schematically showing modifications of the piezoelectric actuator 100 according to the present embodiment. As shown in FIGS. 12 and 13, the piezoelectric actuator 100 can further include a barrier layer 80 so as to cover at least a part of the side surface of the piezoelectric layer 30. The barrier layer 80 may be provided above the insulating layer 60 as shown in FIG. 12, or may be provided below the insulating layer 60 as shown in FIG. When the barrier layer 80 is provided above the upper electrode 40, an opening 82 can be provided above the upper electrode 40 in order to electrically connect the upper electrode 40 and the wiring part 70. .

  The barrier layer 80 has a function of preventing impurities such as hydrogen, water, and a compound containing carbon diffusing from the outside from diffusing into the piezoelectric layer 30 and deteriorating the piezoelectric layer 30. The thickness of the barrier layer 80 is preferably a thickness that does not hinder the operation of the piezoelectric actuator 100. If the barrier layer 80 is too thick, the operation of the piezoelectric actuator 100 is restricted. Therefore, it is not formed thick enough to ensure insulation between the lower electrode 20 and the wiring part 70. As a material of the barrier layer 80, it is only necessary to have a barrier property and an insulating property. For example, aluminum oxide is preferable. Such a barrier layer 80 can be provided by, for example, a sputtering method or a vapor deposition method before the above-described insulating layer 60a is formed or after the insulating layer 60 is formed.

  The piezoelectric actuator 100 further including such a barrier layer 80 corresponds to high density, and sufficient electrical insulation between the lower electrode 20 and the wiring portion 70 is ensured. In addition, the piezoelectric layer 30 Has a piezoelectric element 50 that is difficult to deteriorate.

  14 and 16 are cross-sectional views schematically showing modifications of the piezoelectric actuator 100 according to the present embodiment. 15 and 17 are plan views schematically showing modifications of the piezoelectric actuator 100 according to the present embodiment. In FIG. 15, the insulating layer 60 is depicted with the end portion shown by a broken line and seen through. 14 and FIG. 16 correspond to cross sections taken along line AA in FIG. 15 and line AA in FIG.

  As shown in FIGS. 14 and 15, the piezoelectric actuator 100 can further include a bank 90 having a side surface facing the side surface of the piezoelectric element 50 on the base 10. An insulating layer 60 can be provided between the bank 90 and the piezoelectric element 50. A wiring unit 70 is provided above the bank 90. When a plurality of wiring parts 70 are provided on the bank 90, the bank 90 is provided so that the wiring parts 70 are insulated from each other. Since the bank 90 is provided to face the side surface of the piezoelectric element 50, a recess is formed between the side surface of the piezoelectric element 50 and the side surface of the bank 90.

  14 and 15, the bank 90 is obtained by removing the upper electrode 40 from the configuration of the piezoelectric element 50. In this example, since the region of the bank 90 that contacts the wiring portion 70 is the piezoelectric layer 93, the wiring portions 70 are insulated from each other. The material of the bank 90 is arbitrary as long as the wiring portions 70 are insulated from each other when the plurality of wiring portions 70 are provided. For example, in FIG. 14 and FIG. 15, the lower portion of the bank 90 has a lower electrode 92, but the wiring portion 70 is insulated from each other, and thus may be such a bank 90. The bank 90 may be composed of a single layer or a plurality of layers.

  As shown in FIG. 14, the bank 90 has a function of keeping the thickness of the insulating layer 60 thicker than when the bank 90 is not provided (insulating layer 62). Therefore, it is sufficient that the height of the bank 90 is higher than the thickness of the lower electrode 20 of the piezoelectric element 50. An insulating layer 60 may be provided on the bank 90. When the insulating layer 60 is formed by the SOG method or the ink jet method, the bank 90 has an effect of suppressing that the material of the applied insulating layer 60 flows and becomes thin.

  FIGS. 16 and 17 are examples in which the piezoelectric actuator 100 having the bank 90 is provided with an insulating layer 60 by an ink jet method. As shown in FIGS. 16 and 17, even when the insulating layer 60 is formed by the ink jet method, the bank 90 prevents the raw material of the insulating layer 60 from flowing out to other regions. Thereby, the insulating layer 60 can reliably cover the lower electrode 20 and a part of the piezoelectric layer 30 on the side surface of the piezoelectric element 50.

  The bank 90 is provided before the step of providing the insulating layer 60. 14 to 17, the bank 90 has a lower electrode 92 and a piezoelectric layer 93 structure common to the piezoelectric element 50. Therefore, the bank 90 can be provided by patterning so as to leave the bank 90 in the step of forming the piezoelectric element 50. As a method for forming the bank 90, after the piezoelectric element 50 is formed, a photo-curing resin or the like can be provided on the substrate 10 by patterning. Furthermore, the bank 90 may be formed by applying a resin on the substrate 10 by inkjet after forming the piezoelectric element 50.

  By providing the bank 90 in this manner, the amount of the insulating layer 60 can be reduced, and the operation load of the piezoelectric actuator 100 can be further reduced.

4). Liquid Ejecting Head FIG. 18 is a cross-sectional view schematically showing a liquid ejecting head 1000 having the piezoelectric actuator 100 of the present embodiment. FIG. 19 is a plan view schematically showing a liquid jet head 1000 having the piezoelectric actuator 100 of the present embodiment. A cross section taken along line BB in FIG. 19 corresponds to FIG.

  The liquid ejecting head 1000 according to this embodiment includes a piezoelectric actuator 100, a pressure chamber substrate 200, and a nozzle plate 300.

  The pressure chamber substrate 200 is provided below the piezoelectric actuator 100. The pressure chamber substrate 200 constitutes a side wall of the pressure chamber 210. As shown in FIG. 18, the pressure chamber 210 is formed below the piezoelectric actuator 100 corresponding to the position of the piezoelectric element 50. The upper wall of the pressure chamber 210 is constituted by the base body 10 of the piezoelectric actuator 100. The pressure chamber 210 communicates with a liquid reservoir (not shown). The pressure chamber 210 is supplied with liquid from the liquid reservoir. As a material of the pressure chamber substrate 200, for example, silicon, stainless steel, SUS, nickel, titanium, titanium alloy, or the like can be used.

  The nozzle plate 300 is provided below the pressure chamber substrate 200. The nozzle plate 300 constitutes a lower wall of the pressure chamber 210 and has a plurality of nozzle holes 310 corresponding to the pressure chamber 210. The liquid filled in the pressure chamber 210 is discharged from the nozzle hole 310 by the operation of the piezoelectric actuator 100. As the material of the nozzle plate 300, for example, silicon, stainless steel, titanium, titanium alloy, or the like can be used.

  The liquid ejecting head 1000 can be manufactured as follows. The piezoelectric actuator 100, the pressure chamber substrate 200, and the nozzle plate 300 are prepared in advance. The pressure chamber substrate 200 is formed, for example, by patterning a silicon substrate by forming a mask pattern using a photolithographic method and etching it. The nozzle plate 300 can be manufactured, for example, by cutting a stainless plate and drilling the nozzle hole 310 at a predetermined position. By assembling the piezoelectric actuator 100, the pressure chamber substrate 200, and the nozzle plate 300 manufactured as described above at predetermined positions using a known positioning means or the like, using an adhesive or the like as necessary, a liquid jet The head 1000 is manufactured.

  Since the liquid ejecting head 1000 according to the present embodiment includes the piezoelectric actuator 100 having the piezoelectric elements 50 arranged at high density, the printed matter has high definition when used for inkjet printing.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

1 is a cross-sectional view schematically showing a piezoelectric actuator 100 according to the present invention. The top view which shows typically the piezoelectric actuator 100 concerning this invention. 1 is a cross-sectional view schematically showing a piezoelectric actuator 100 according to the present invention. The top view which shows typically the piezoelectric actuator 100 concerning this invention. Sectional drawing which shows the manufacturing process of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the manufacturing process of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the manufacturing process of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the manufacturing process of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the modification of the piezoelectric actuator 100 of this invention typically. The top view which shows typically the modification of the piezoelectric actuator 100 of this invention. Sectional drawing which shows the modification of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the modification of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the modification of the piezoelectric actuator 100 of this invention typically. Sectional drawing which shows the modification of the piezoelectric actuator 100 of this invention typically. The top view which shows typically the modification of the piezoelectric actuator 100 of this invention. Sectional drawing which shows the modification of the piezoelectric actuator 100 of this invention typically. The top view which shows typically the modification of the piezoelectric actuator 100 of this invention. FIG. 3 is a cross-sectional view schematically showing a liquid jet head 1000 according to the present invention. FIG. 2 is a plan view schematically showing a liquid jet head 1000 according to the present invention.

Explanation of symbols

10 substrate, 20 lower electrode, 22 lower electrode lower layer, 24 lower electrode upper layer,
30 piezoelectric layer, 40 upper electrode, 50 piezoelectric element, 60 insulating layer, 62 insulating layer,
70 wiring portion, 80 barrier layer, 82 opening, 90 bank, 92 lower electrode,
93 Piezoelectric layer, 100 Piezoelectric actuator, 200 Pressure chamber substrate, 210 Pressure chamber 300 Nozzle plate, 310 Nozzle hole

Claims (11)

A substrate;
A lower electrode provided above the substrate;
A piezoelectric layer provided above the lower electrode;
An upper electrode provided above the piezoelectric layer;
A wiring portion electrically connected to the upper electrode;
An insulating layer for electrically insulating the lower electrode and the wiring portion;
Including
A piezoelectric element is constituted by the lower electrode, the piezoelectric layer and the upper electrode,
The insulating layer is provided so as to cover the lower electrode and at least a part of a side surface of the piezoelectric layer,
The wiring portion is a piezoelectric actuator formed above the insulating layer. In claim 1,
The insulating layer is a piezoelectric actuator provided on an outer periphery of the piezoelectric element. In claim 1,
The said insulating layer is a piezoelectric actuator provided in a part of outer periphery of the said piezoelectric element. In any one of Claims 1 thru | or 3,
The insulating layer is a piezoelectric actuator composed of an oxide containing silicon. In any one of Claim 1 thru | or 4,
The lower electrode includes a plurality of layers, and the piezoelectric actuator is provided so that an outer periphery of a part of the plurality of layers is located inside an outer periphery of a lower surface of the piezoelectric layer. In any one of Claims 1 thru | or 5,
Furthermore, the piezoelectric actuator provided with the barrier layer so that at least one part of the side surface of the said piezoelectric material layer might be covered. In any one of Claims 1 thru | or 6,
Furthermore, the piezoelectric actuator which provided the bank which has a side surface which opposes the side surface of the said piezoelectric element on the said base | substrate, and provided the said insulating layer between the said bank and the said piezoelectric element.   A liquid ejecting head comprising the piezoelectric actuator according to claim 1. A step of sequentially laminating a lower electrode, a piezoelectric layer, and an upper electrode above the substrate;
Patterning the upper electrode, the piezoelectric layer, and the lower electrode to form a piezoelectric element;
Forming an insulating layer so as to cover at least a part of the side surface of the lower electrode and the piezoelectric layer;
Forming a wiring portion electrically connected to the upper electrode above the insulating layer;
A method for manufacturing a piezoelectric actuator, comprising: In claim 9,
The step of forming the insulating layer is a method of manufacturing a piezoelectric actuator, which is performed by a spin-on-glass (SOG) method. In claim 9,
The step of forming the insulating layer is a method of manufacturing a piezoelectric actuator, which is performed by an ink jet method.

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