Liquid dispensing head, liquid dispensing device, and method for manufacturing a liquid dispensing head

Abstract

Reduces damage such as cracks. [Solution] The liquid discharge head comprises a pressure chamber substrate having a plurality of pressure chambers arranged in a first direction, a diaphragm disposed on the pressure chamber substrate, a first electrode disposed on the diaphragm, a piezoelectric layer disposed on the first electrode, a second electrode disposed on the piezoelectric layer, and a seed layer located between the piezoelectric layer and the diaphragm for controlling the orientation of the piezoelectric layer, wherein the piezoelectric layer has a first region that does not overlap with the first electrode in the first direction and a second region that overlaps with the first electrode in the first direction, and the seed layer includes a first seed layer that is not disposed in the first region but is disposed in the second region, and a second seed layer provided on the first seed layer and disposed across both the first and second regions.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head, a liquid ejection device, and a method for manufacturing a liquid ejection head.

Background Art

[0002] In a liquid ejection head in which a diaphragm, a first electrode, a piezoelectric layer, and a second electrode are laminated in this order on a pressure chamber substrate having a plurality of pressure chambers, a seed layer for controlling the orientation of the piezoelectric layer may be provided between the piezoelectric layer and the diaphragm. For example, Patent Document 1 describes that a single-layer seed layer is uniformly formed on a patterned first electrode, and then a piezoelectric layer is formed on the seed layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, due to the heat treatment during the formation of the seed layer, the material contained in the layer directly under the first electrode concentrates and precipitates at the end of the first electrode. When such local segregation of the material occurs, it becomes an oxide, causing the piezoelectric layer to float at the end of the first electrode, and as a result, there is a risk of cracking.

Means for Solving the Problems

[0005] To solve the above problems, a liquid discharge head according to a preferred embodiment of the present disclosure comprises: a pressure chamber substrate having a plurality of pressure chambers arranged in a first direction; a diaphragm disposed on the pressure chamber substrate; a first electrode disposed on the diaphragm; a piezoelectric layer disposed on the first electrode; a second electrode disposed on the piezoelectric layer; and a seed layer located between the piezoelectric layer and the diaphragm for controlling the orientation of the piezoelectric layer, wherein the piezoelectric layer has a first region that does not overlap with the first electrode in the first direction and a second region that overlaps with the first electrode in the first direction; and the seed layer includes a first seed layer that is not disposed in the first region but is disposed in the second region, and a second seed layer provided on the first seed layer and distributed across both the first and second regions.

[0006] A liquid dispensing device according to a preferred embodiment of the present disclosure comprises a liquid dispensing head as described above and a control unit that controls the dispensing operation from the liquid dispensing head.

[0007] A preferred embodiment of the present disclosure is a method for manufacturing a liquid discharge head, comprising: a pressure chamber substrate having a plurality of pressure chambers arranged in a first direction; and a diaphragm disposed on the pressure chamber substrate, the method comprising: applying a layer formed of a first electrode material onto the diaphragm; applying a layer formed of a first seed layer material onto the layer formed of the first electrode material; heat-treating the layer formed of the first seed layer material; patterning the layer formed of the first electrode material and the layer formed of the first seed layer material; applying a layer formed of a second seed layer material onto the diaphragm and the layer formed of the first seed layer material; heat-treating the layer formed of the second seed layer material; and applying a piezoelectric material onto the layer formed of the second seed layer material, in this order. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an example configuration of a liquid dispensing device according to the embodiment. [Figure 2] This is an exploded perspective view of the liquid dispensing head according to the first embodiment. [Figure 3] This is a cross-sectional view along line AA in Figure 2. [Figure 4] Figure 2 is a plan view of a portion of the liquid discharge head. [Figure 5] This is a cross-sectional view along line BB in Figure 4. [Figure 6] This is an enlarged view of part α in Figure 5. [Figure 7] This is an explanatory diagram of a method for manufacturing a liquid dispensing head according to an embodiment. [Figure 8] This is an explanatory diagram of a method for manufacturing a liquid dispensing head according to an embodiment. [Figure 9] This is an explanatory diagram of the manufacturing method for a liquid dispensing head according to Comparative Example 1. [Figure 10] This is an explanatory diagram of the manufacturing method for a liquid dispensing head according to Comparative Example 2. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present disclosure will be described below with reference to the attached drawings. Note that the dimensions and scale of parts in the drawings may differ from actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of the present disclosure is not limited to these embodiments unless otherwise stated in the following description.

[0010] For convenience, the following explanation will use the X, Y, and Z axes intersecting each other as appropriate. In the following, one direction along the X axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. Similarly, opposite directions along the Y axis are the Y1 and Y2 directions. The Y1 or Y2 direction is an example of a "first direction". Also, opposite directions along the Z axis are the Z1 and Z2 directions. The Z1 direction is an example of a "second direction". In the following, viewing in the Z1 or Z2 direction may be referred to as a "planar view".

[0011] Here, typically, the Z-axis is the vertical axis, and the Z2 direction corresponds to the downward direction in the vertical. However, the Z-axis does not have to be the vertical axis. Also, the X, Y, and Z axes are typically orthogonal to each other, but are not limited to this; for example, they can intersect at an angle within the range of 80° to 100°.

[0012] 1: First Embodiment 1-1: Overall configuration of the liquid dispensing device Figure 1 is a schematic diagram showing an example of the configuration of a liquid ejection device 100 according to an embodiment. The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets toward a recording medium M. The recording medium M is, for example, printing paper. However, the recording medium M is not limited to printing paper, and may be any material to be printed on, for example, a resin film or a cloth.

[0013] As shown in Figure 1, the liquid dispensing device 100 comprises a liquid container 10, a control module 20, a transport mechanism 30, a moving mechanism 40, and a plurality of liquid dispensing heads 50. The control module 20 is an example of a "control unit".

[0014] The liquid container 10 stores ink. Specific examples of the liquid container 10 include a cartridge detachable from the liquid dispensing device 100, a bag-shaped ink pack made of flexible film, and an ink tank from which ink can be refilled. The type of ink stored in the liquid container 10 is arbitrary.

[0015] The control module 20 controls the operations of each element of the liquid ejection device 100. The control module 20 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory. Here, the control module 20 outputs a drive signal Com for driving the liquid ejection head 50 and a control signal SI for controlling the drive of the liquid ejection head 50. With such a drive signal Com and control signal SI, the control module 20 controls the ejection operation from the liquid ejection head 50.

[0016] The transport mechanism 30 transports the recording medium M along the Y-axis under the control of the control module 20.

[0017] The moving mechanism 40 reciprocates the liquid ejection head 50 along the X-axis under the control of the control module 20. The moving mechanism 40 has a substantially box-shaped carrier 41 called a carriage that houses the liquid ejection head 50, and an endless conveyor belt 42 to which the carrier 41 is fixed. In addition to the liquid ejection head 50, the aforementioned liquid container 10 may be mounted on the carrier 41.

[0018] Each of the plurality of liquid ejection heads 50 ejects ink supplied from the liquid container 10 onto the recording medium M from each of the plurality of nozzles N under the control of the control module 20. By performing this ejection in parallel with the conveyance of the recording medium M by the transport mechanism 30 and the reciprocating movement of the liquid ejection head 50 by the moving mechanism 40, an image with ink is formed on the surface of the recording medium M.

[0019] In the example shown in FIG. 1, the number of liquid ejection heads 50 is four. Note that the number of liquid ejection heads 50 is not limited to the example shown in FIG. 1 and is arbitrary, and may be a single number, or a plurality of three or less or five or more. Also, the arrangement of the plurality of liquid ejection heads 50 is not limited to the example shown in FIG. 1 and is arbitrary.

[0020] 1-2: Liquid ejection head Figure 2 is an exploded perspective view of the liquid dispensing head 50 according to the first embodiment. Figure 3 is a cross-sectional view taken along line AA in Figure 2. An example of the configuration of the liquid dispensing head 50 will be described below.

[0021] As shown in Figures 2 and 3, the liquid discharge head 50 has a plurality of nozzles N arranged in the direction along the Y axis.

[0022] The multiple nozzles N of the liquid discharge head 50 are divided into a first nozzle row Ln1 and a second nozzle row Ln2, which are spaced apart from each other in the direction along the X axis. Each of the first nozzle row Ln1 and the second nozzle row Ln2 is a collection of multiple nozzles N arranged linearly in the direction along the Y axis.

[0023] The liquid discharge head 50 has a configuration that is substantially symmetrical with respect to the X-axis. However, the positions of the multiple nozzles N of the first nozzle row Ln1 and the multiple nozzles N of the second nozzle row Ln2 along the Y-axis may coincide or differ. Figures 2 and 3 illustrate a configuration in which the positions of the multiple nozzles N of the first nozzle row Ln1 and the multiple nozzles N of the second nozzle row Ln2 along the Y-axis coincide.

[0024] As shown in Figures 2 and 3, the liquid discharge head 50 includes a communication substrate 510, a pressure chamber substrate 520, a nozzle plate 530, a vibration absorber 540, a diaphragm 550, a plurality of piezoelectric elements 560, a protective substrate 570, a case 580, and a wiring substrate 590.

[0025] The communication substrate 510 and the pressure chamber substrate 520 are stacked in this order in the Z1 direction, forming a flow path for supplying ink to multiple nozzles N. A diaphragm 550, multiple piezoelectric elements 560, a protective substrate 570, a case 580, a wiring board 590, and a drive circuit 600 are installed in the region located in the Z1 direction from the stack consisting of the communication substrate 510 and the pressure chamber substrate 520. On the other hand, a nozzle plate 530 and a vibration absorber 540 are installed in the region located in the Z2 direction from the said stack. Each element of the liquid discharge head 50 is generally a plate-shaped member that is elongated in the Y direction, and is joined to each other, for example, by adhesive. The elements of the liquid discharge head 50 will be described in order below.

[0026] The nozzle plate 530 is a plate-shaped member provided with a plurality of nozzles N in the first nozzle row Ln1 and the second nozzle row Ln2, respectively. Each of the plurality of nozzles N is a through hole through which ink passes. Here, the surface of the nozzle plate 530 facing the Z2 direction is the nozzle surface FN. The nozzle plate 530 is manufactured by processing a silicon single crystal substrate using semiconductor manufacturing technology, such as dry etching or wet etching. However, other known methods and materials may be used in the manufacture of the nozzle plate 530 as appropriate. In addition, the cross-sectional shape of the nozzles N is typically circular, but is not limited to this, and may be non-circular, such as polygonal or elliptical.

[0027] The communication substrate 510 is provided with a flow path R1, a plurality of supply flow paths Ra, and a plurality of communication flow paths Na for each of the first nozzle row Ln1 and the second nozzle row Ln2. Flow path R1 is a flow path provided in common to the plurality of nozzles N, and is a flow path that communicates with the plurality of nozzles N and is upstream of the nozzles N, and is composed of an elongated hole that extends in the direction along the Y axis in a plan view taken in the direction along the Z axis. Each of the supply flow path Ra and communication flow path Na is a flow path composed of a through hole formed for each nozzle N. Each supply flow path Ra communicates with flow path R1.

[0028] The connecting substrate 510 is manufactured, similar to the nozzle plate 530 described above, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology. However, other known methods and materials may be used in the manufacture of the connecting substrate 510 as appropriate.

[0029] The pressure chamber substrate 520 is a plate-shaped member provided with a plurality of pressure chambers C1, called cavities, for each of the first nozzle row Ln1 and the second nozzle row Ln2. The plurality of pressure chambers C1 are arranged in the direction along the Y axis. Each pressure chamber C1 is formed for each nozzle N and is a long space extending in the direction along the X axis in a plan view. As described above, the pressure chamber substrate 520 has a plurality of pressure chambers C1 arranged in the Y1 direction or the Y2 direction.

[0030] The pressure chamber substrate 520 is manufactured, similar to the nozzle plate 530 described above, for example, by processing a silicon single crystal substrate using semiconductor manufacturing technology. However, other known methods and materials may be used in the manufacture of the pressure chamber substrate 520 as appropriate.

[0031] The pressure chamber C1 is located between the communication substrate 510 and the diaphragm 550. For each of the first nozzle row Ln1 and the second nozzle row Ln2, multiple pressure chambers C1 are arranged in a direction along the Y axis. The pressure chamber C1 also communicates with the communication channel Na and the supply channel Ra, respectively. Therefore, the pressure chamber C1 communicates with the nozzle N via the communication channel Na and with the channel R1 via the supply channel Ra.

[0032] The diaphragm 550 is positioned on the surface of the pressure chamber substrate 520 facing the Z1 direction. The diaphragm 550 is an elastically vibrable plate-shaped member and vibrates due to the piezoelectric element 560. Details of the diaphragm 550 will be described later with reference to Figure 5.

[0033] On the surface of the diaphragm 550 facing the Z1 direction, a plurality of piezoelectric elements 560 corresponding to the nozzles N are arranged for each of the first nozzle row Ln1 and the second nozzle row Ln2. Each piezoelectric element 560 is a passive element that deforms when a potential corresponding to the drive signal Com is supplied, causing pressure fluctuations in the ink in the pressure chamber C1. Each piezoelectric element 560 is elongated in the direction along the X axis in a plan view. The plurality of piezoelectric elements 560 are arranged in the direction along the Y axis to correspond to the plurality of pressure chambers C1. The piezoelectric elements 560 overlap the pressure chambers C1 in a plan view. The piezoelectric elements 560 apply pressure to the pressure chambers C1 which are in communication with the nozzles N that eject the ink. Details of the piezoelectric elements 560 will be explained later with reference to Figures 4 to 6.

[0034] The protective substrate 570 is a plate-shaped member installed on the surface of the diaphragm 550 facing the Z1 direction, protecting the plurality of piezoelectric elements 560 and reinforcing the mechanical strength of the diaphragm 550. Here, the plurality of piezoelectric elements 560 are housed in the space S between the protective substrate 570 and the diaphragm 550. The protective substrate 570 is made of, for example, a resin material.

[0035] Case 580 is a case for storing ink supplied to multiple pressure chambers C1. Case 580 is made of, for example, a resin material. Case 580 is provided with a flow path R2 for each of the first nozzle row Ln1 and the second nozzle row Ln2. Flow path R2 is a space connected to the aforementioned flow path R1 and is composed of an elongated hole extending in the direction along the Y axis in a plan view taken in the direction along the Z axis. Flow path R2 is in communication with the nozzles N and, together with flow path R1, functions as a reservoir R for storing ink supplied to multiple pressure chambers C1. Case 580 is provided with inlets HL for supplying ink to each reservoir R. The ink in each reservoir R is supplied to the pressure chamber C1 via each supply flow path Ra. Note that the position and number of inlets HL for each reservoir R are not limited to the examples in Figures 2 and 3 and are arbitrary.

[0036] The vibration absorber 540, also called the compliance substrate, is a flexible resin film that forms the wall surface of the reservoir R and absorbs pressure fluctuations of the ink in the reservoir R. The vibration absorber 540 may also be a flexible thin plate made of metal. The surface of the vibration absorber 540 facing the Z1 direction is joined to the communication substrate 510 by adhesive or the like.

[0037] The wiring board 590 is mounted on the surface of the diaphragm 550 facing the Z1 direction and is a mounting component for electrically connecting the control module 20 and the liquid discharge head 50. The wiring board 590 is a flexible wiring board such as COF (Chip On Film), FPC (Flexible Printed Circuit), or FFC (Flexible Flat Cable). In this embodiment, a drive circuit 600 is mounted on the wiring board 590. Under the control of the control module 20, the drive circuit 600 switches whether or not to supply pulses included in the drive signal Com output from the control module 20 to each of the plurality of piezoelectric elements 560 of the liquid discharge head 50. As described above, the wiring board 590 supplies the drive signal Com that drives the piezoelectric elements 560. Note that the wiring board 590 may be a rigid board. In this case, the drive circuit 600 is mounted on the rigid board or on a flexible board connected to the rigid board.

[0038] 1-3: Piezoelectric element Figure 4 is a plan view of a part of the liquid discharge head 50 shown in Figure 2. Figure 5 is a cross-sectional view along line BB in Figure 4. Figure 6 is an enlarged view of part α in Figure 5. In Figure 4, for ease of viewing, the portion of the second electrode 562 not covered by the second wiring 120 described later is indicated by dots.

[0039] The configuration of the diaphragm 550 and the piezoelectric element 560 will be described below with reference to Figures 4 to 6.

[0040] The diaphragm 550 has a first layer 551 and a second layer 552, which are stacked in this order in the Z1 direction.

[0041] The first layer 551 is an elastic film composed of, for example, silicon oxide (SiO2), and is formed by thermal oxidation of one side of a silicon single crystal substrate. The second layer 552 is an insulating film composed of, for example, zirconium oxide (ZrO2), and is formed by forming a zirconium layer by sputtering and then thermally oxidizing the layer.

[0042] The diaphragm 550 is not limited to the lamination of the first layer 551 and the second layer 552 described above, but may also be composed of a single layer or three or more layers. Furthermore, the material of each layer constituting the diaphragm 550 is not limited to the materials described above, but may be silicon or silicon nitride, for example. For example, in addition to ZrO2, TiO2, Al2O3, SiO2, SiN, etc. can be used as the material constituting the second layer 552. Also, the relative thicknesses of the first layer 551 and the second layer 552 are not limited to the illustrated example and are arbitrary.

[0043] Multiple piezoelectric elements 560 are arranged on the surface of the diaphragm 550 facing the Z1 direction. As shown in Figure 5, each piezoelectric element 560 has a first electrode 561, a second electrode 562, a piezoelectric layer 563, and a seed layer 130. These are the first electrode 561, the piezoelectric layer 563, the second electrode 562, and the seed layer 130, and they are stacked in this order in the Z1 direction. Thus, the liquid discharge head 50 has the first electrode 561, the piezoelectric layer 563, the second electrode 562, and the seed layer 130.

[0044] In the piezoelectric element 560, when a voltage is applied between the first electrode 561 and the second electrode 562, the piezoelectric layer 563 deforms due to the inverse piezoelectric effect. When the diaphragm 550 vibrates in conjunction with this deformation, the pressure in the pressure chamber C1 fluctuates, causing ink to be ejected from the nozzle N. In the piezoelectric element 560, when viewed along the Z-axis, the part where the first electrode 561, the second electrode 562, and the piezoelectric layer 563 overlap is the active part, and the part other than the active part is the inactive part.

[0045] As shown in Figure 4, the first electrode 561 is electrically connected to the first wiring 110, and a drive signal Com is supplied via the first wiring 110. The first wiring 110 is a lead wire provided individually for each piezoelectric element 560 and is electrically connected to the first electrode 561 of the corresponding piezoelectric element 560. On the other hand, the second electrode 562 is electrically connected to the second wiring 120, and a constant potential is supplied via the second wiring 120. The second wiring 120 is a common wiring provided in common to multiple piezoelectric elements 560 and is electrically connected to the second electrode 562.

[0046] In the example shown in Figure 4, the first wiring 110 is connected to the first electrode 561 and is drawn out from the first electrode 561 toward the wiring board 590 for each piezoelectric element 560. On the other hand, the second wiring 120 is drawn out from both ends of the second electrode 562 in the Y1 and Y2 directions toward the wiring board 590 toward the diaphragm 550. Here, the second wiring 120 has strip-shaped conductive layers 121 and 122 extending in the Y1 direction. The conductive layers 121 and 122 are arranged at a predetermined interval in the X1 direction. Such second wiring 120 also functions as a weight to suppress vibration of the diaphragm 550.

[0047] The constituent materials of the first wiring 110 and the second wiring 120 are not particularly limited, but examples include metals such as gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), and aluminum (Al). Among these, gold (Au) is preferably used as the constituent material for the first wiring 110 and the second wiring 120. Here, for each of the first wiring 110 and the second wiring 120, a structure in which a layer made of gold is laminated as a surface layer on top of a layer made of nickel-chromium or the like is preferably used.

[0048] The first electrode 561 is an individual electrode positioned on the diaphragm 550, spaced apart from each other for each piezoelectric element 560. A drive signal Com is supplied to the first electrode 561. The second electrode 562 is a common strip-shaped electrode positioned on the piezoelectric layer 563, extending along the Y-axis to be continuous across multiple piezoelectric elements 560. A constant potential is supplied to the second electrode 562, for example.

[0049] Examples of materials that make up the first electrode 561 and the second electrode 562 include metallic materials such as platinum (Pt), aluminum (Al), iridium (Ir), nickel (Ni), gold (Au), and copper (Cu). Of these, one type can be used alone, or two or more types can be used in combination in the form of an alloy or laminate.

[0050] When the first electrode 561 contains Ir, the diffusion of components contained in the piezoelectric layer 563 can be suppressed, as will be described later. As a result, changes in the composition of the piezoelectric layer 563 can be suppressed.

[0051] In the examples shown in Figures 5 and 6, an adhesion layer 561b is placed between the diaphragm 550 and the first electrode 561. The adhesion layer 140 is a layer that enhances the adhesion between the first electrode 561 and the diaphragm 550, and is made of a metal such as titanium. At least a portion of the adhesion layer 140 can also be considered as part of the first electrode 561 or the diaphragm 550. Furthermore, the layer made of titanium may be interposed between the first electrode 561 and the diaphragm 550 for some reason.

[0052] The piezoelectric layer 563 is placed on the first electrode 561 and is composed of a piezoelectric material. A composite oxide having a perovskite structure represented by the general composition formula ABO3 is preferably used as the piezoelectric material. Examples of such composite oxides include lead zirconate titanate (Pb(Zr,Ti)O3), lead magnesium niobate / lead titanate solid solution (Pb(Mg,Nb)O3-PbTiO3), etc. Furthermore, the composite oxide is not limited to the lead-containing compounds mentioned above, but may also be lead-free compounds, such as potassium sodium niobate ((K,Na)NbO3, abbreviated as "KNN"), bismuth ironate ((BiFeO3, abbreviated as "BFO"), potassium sodium lithium niobate ((K,Na,Li)(NbO3)), potassium sodium lithium tantalate niobate ((K,Na,Li)(Nb,Ta)O3), bismuth manganese (BiMnO3, abbreviated as "BM"), etc. In this way, when the piezoelectric layer 563 contains K, Na, and Nb, the piezoelectric layer 563 can be constructed from a lead-free material.

[0053] In the example shown in Figure 4, the piezoelectric layer 563 is a strip-shaped structure extending along the Y-axis so as to be continuous across multiple piezoelectric elements 560. Here, the piezoelectric layer 563 is provided with notches G extending along the X-axis, penetrating the piezoelectric layer 563 in regions corresponding to the gaps between adjacent pressure chambers C1 in a plan view. Note that the piezoelectric layer 563 may be provided individually for each piezoelectric element 560. The notches G may also be closed-end grooves.

[0054] As shown in Figure 6, the piezoelectric layer 563 has a first region A1, a second region A2, and a third region A3. The first region A1 is a region of the piezoelectric layer 563 that does not overlap with the first electrode 561 in the Y1 or Y2 direction. In other words, the first region A1 is a region in the piezoelectric layer 563 whose range along the Y axis is different from that of the first electrode 561. On the other hand, the second region A2 is a region of the piezoelectric layer 563 that overlaps with the first electrode 561 in the Y1 or Y2 direction. In other words, the second region A2 is a region in the piezoelectric layer 563 whose range along the Y axis is the same as that of the first electrode 561. The third region A3 is a region of the piezoelectric layer 563 that is located between the first region A1 and the second region A2 in the Y1 or Y2 direction.

[0055] In the example shown in Figure 6, the first region A1 is stacked on a region F1 on the upper surface of the diaphragm 550 that is flat along the Y1 or Y2 direction when viewed in a cross section perpendicular to the X-axis. Region F1 can also be described as a flat region on the upper surface of the diaphragm 550 that is aligned with a virtual plane perpendicular to the Z-axis. On the other hand, the second region A2 is stacked on a region F2 on the upper surface of the first electrode 561 that is flat along the Y1 or Y2 direction when viewed in a cross section perpendicular to the X-axis. Region F2 can also be described as a flat region on the upper surface of the first electrode 561 that is aligned with a virtual plane perpendicular to the Z-axis. The third region A3 is stacked on a region F3 on the upper surface of the first electrode 561 that is inclined with respect to the Y1 or Y2 direction when viewed in a cross section perpendicular to the X-axis. Region F3 can also be described as a flat region on the upper surface of the first electrode 561 that is inclined around the X-axis with respect to a virtual plane perpendicular to the Z-axis.

[0056] The inclination angle of region F3 with respect to a virtual plane perpendicular to the Z-axis is not particularly limited and can be arbitrary, as long as it is greater than 0° and less than 90°. Furthermore, the inclination of region F3 with respect to the virtual plane perpendicular to the Z-axis can be formed, for example, by adjusting the etching rate when patterning the first electrode 561 by etching, or by using a grayscale mask.

[0057] The seed layer 130 is located between the piezoelectric layer 563 and the diaphragm 550 and is a layer for controlling the orientation of the piezoelectric layer 563. The seed layer 130 is in contact with the first electrode 561, the diaphragm 550, and the piezoelectric layer 563, and has a crystalline structure that serves as a seed crystal for the piezoelectric layer 563. This improves the orientation of the piezoelectric layer 563. As a result, the displacement force of the piezoelectric element 560 can be increased. Therefore, the discharge performance of the liquid discharge head 50 can be improved.

[0058] The material constituting the seed layer 130 may be any material that has the function of controlling the orientation of the piezoelectric layer 563, but it is preferable that it contains titanium (Ti), and more preferably that it contains bismuth (Bi) iron (Fe), titanium (Ti), and lead (Pb). A material containing bismuth (Bi) iron (Fe), titanium (Ti), and lead (Pb) can control the orientation of the piezoelectric layer 563 as a composite oxide having a perovskite structure with Bi and Pb at site A and Fe and Ti at site B.

[0059] The seed layer 130 includes a first seed layer 131 and a second seed layer 132. The first seed layer 131 is not located in the first region A1, but is located in the second region A2. The second seed layer 132 is located above the first seed layer 131 and spans both the first region A1 and the second region A2.

[0060] Each of these first seed layer 131 and second seed layer 132 is composed of a material capable of controlling the orientation of the piezoelectric layer 563 as described above. Here, since the second seed layer 132 is arranged across both the first region A1 and the second region A2, the orientation of the piezoelectric layer 563 can be controlled in both the active and inactive parts. Therefore, the occurrence of damage such as cracks caused by differences in the orientation of the piezoelectric layer 563 between the active and inactive parts can be reduced.

[0061] Furthermore, since the second seed layer 132 is provided on top of the first seed layer 131, it is formed after the formation of the first seed layer 131, as will be described in detail later. Also, the first seed layer 131 can be heat-treated before patterning the first electrode 561 and the first seed layer 131. During this heat treatment, diffusible materials (especially Ti) in the layers such as the adhesion layer 140 directly beneath the first electrode 561 cannot diffuse laterally but diffuses in the thickness direction. Therefore, the materials of the layers such as the adhesion layer 140 do not concentrate and precipitate during this heat treatment. In addition, the second seed layer 132 is heat-treated after patterning the first seed layer 131, but by this time, the diffusible materials in the layers such as the adhesion layer 140 have completely diffused. Therefore, the materials of the layers such as the adhesion layer 140 do not concentrate and precipitate at the edges of the first electrode 561 during this heat treatment. From the above, the occurrence of damage such as cracks caused by localized segregation of materials such as Ti in the layers such as the adhesion layer 140 can also be reduced.

[0062] Here, if the first electrode 561 contains Ir, the Ir contained in the first electrode 561 is easily diffused by heat treatment. Furthermore, the effect of Ir in suppressing the diffusion of Ti is particularly pronounced compared to other combinations of elements. Therefore, when Ti segregates, including Ir in the first electrode 561 significantly reduces the occurrence of localized segregation of the material in layers such as the adhesion layer 140 by using the first seed layer 131 and the second seed layer 132.

[0063] Furthermore, if the piezoelectric layer 563 contains K, Na, and Nb, and the piezoelectric layer 563 does not contain Ti, then if the first electrode 561 contains Ti, the affinity between the first electrode 561 and the piezoelectric layer 563 will be low. Therefore, if Ti diffuses from layers such as the adhesion layer 140, the Ti will precipitate on the edge of the first electrode 561 without entering the piezoelectric layer 563. Consequently, in this case, using the first seed layer 131 and the second seed layer 132 significantly reduces the occurrence of local segregation of the material in layers such as the adhesion layer 140.

[0064] The first seed layer 131 is not placed in the third region A3, whereas the second seed layer 132 is placed in the third region A3 as well. This improves the orientation of the third region A3. If the first electrode 561 and the first seed layer 131 are formed by a single patterning, the first seed layer 131 cannot be formed in region F3 of the first electrode 561. If the seed layer 130 is not present in region F3, the third region A3 between the first region A1 and the second region A2 becomes unoriented, resulting in a large difference in orientation between these regions, which may lead to crack formation. In contrast, by providing the second seed layer 132 on region F3, the orientation of the third region A3 can be improved. As a result, the difference in orientation between these regions is reduced, thereby reducing the occurrence of cracks.

[0065] When the thickness of the first seed layer 131 in the second region A2 is a, the thickness of the second seed layer 132 in the second region A2 is b, and the thickness of the second seed layer 132 in the first region A1 is c, it is preferable that a+b>c is satisfied. In other words, it is preferable that the thickness (a+b) of the seed layer 130 in the second region A2 is greater than the thickness c of the seed layer 130 in the first region A1. This allows for a favorable increase in the crystallinity of both the first region A1 and the second region A2 of the piezoelectric layer 563. As a result, the occurrence of cracks in the piezoelectric layer 563 is favorably reduced.

[0066] Here, typically, the thicker the seed layer 130, the better the crystallinity of the piezoelectric layer 563. However, for example, if KNN is used as the material for the piezoelectric layer 563, and ZrO is used as the material for the second layer 552 of the diaphragm 550 XWhen used, in the seed layer 130 above the second layer 552, if the thickness of the seed layer 130 becomes too thick, conversely, the crystallinity of the piezoelectric layer 563 may become low. Therefore, if the seed layer 130 in the non-active part is formed with a thickness equal to or greater than that of the seed layer 130 in the active part, in the non-active part, the piezoelectric layer 563 is directly laminated on the diaphragm 550, so the crystallinity of the piezoelectric layer 563 becomes extremely low, and as a result, cracks may occur in the same way as when the piezoelectric layer 563 in the non-active part is unoriented.

[0067] From this, it is preferable that the thicknesses a, b, and c satisfy the above-mentioned relationship. Thereby, the decrease in the crystallinity of the piezoelectric layer 563 in the non-active part as described above is reduced, so that the crystallinity of both the first region A1 and the second region A2 of the piezoelectric layer 563 can be suitably increased.

[0068] When the thickness of the second seed layer 132 in the second region A2 is b and the thickness of the second seed layer 132 in the first region A1 is c, it is preferable to satisfy b < c. Thereby, it is possible to prevent the thickness of the seed layer 130 in the second region A2 from becoming unnecessarily thick. As a result, the optimization of the orientation control of the piezoelectric layer 563 can be achieved in both the active part and the non-active part. Here, in the active part, since the first seed layer 131 exists, the orientation control of the piezoelectric layer 563 can be performed by the first seed layer 131. On the other hand, in the non-active part, since the first seed layer 131 does not exist, it is necessary to perform the orientation control of the piezoelectric layer 563 by the second seed layer 132. Therefore, by making the thickness c of the second seed layer 132 in the first region A1 thicker than the thickness b of the second seed layer 132 in the second region A2, in other words, by satisfying b < c, the optimization of the orientation control of the piezoelectric layer 563 can be achieved in both the active part and the non-active part.

[0069] On the other hand, if the thickness c of the second seed layer 132 in the first region A1 is made thinner than the thickness b of the second seed layer 132 in the second region A2, the thickness of the seed layer 130 in the active portion becomes too thick in controlling the orientation of the piezoelectric layer 563 in both the active portion and the non-active portion. As a result, due to an increase in the electrical resistance of the seed layer 130 in the active portion, there is a problem that the discharge characteristics deteriorate due to a deterioration in conductivity between the first electrode 561 and the piezoelectric layer 563.

[0070] When the thickness of the first seed layer 131 in the second region A2 is a, the thickness of the second seed layer 132 in the second region A2 is b, and the thickness of the second seed layer 132 in the first region A1 is c, it is preferable to satisfy b < a < c and a + b > c. Thereby, it is possible to satisfy b < c and a + b > c so that the difference between the thicknesses (a + b) and c does not become too large.

[0071] The first seed layer 131 and the second seed layer 132 are each in contact with the first electrode 561 at least partially. Such a first seed layer 131 and second seed layer 132 can be obtained by forming the second seed layer 132 after forming the first seed layer 131.

[0072] The first seed layer 131 and the second seed layer 132 are preferably made of the same material as each other. Thereby, by enhancing the affinity between the first seed layer 131 and the second seed layer 132, the adhesion between the first seed layer 131 and the second seed layer 132 can be enhanced. As a result, peeling between the first seed layer 131 and the second seed layer 132 can be reduced. On the other hand, if the first seed layer 131 and the second seed layer 132 are made of different materials from each other, the affinity between the first seed layer 131 and the second seed layer 132 may deteriorate, and peeling between the first seed layer 131 and the second seed layer 132 may occur due to a deterioration in the adhesion between the first seed layer 131 and the second seed layer 132.

[0073] The first seed layer 131 and the second seed layer 132 preferably each contain Ti. This makes it possible to realize the first seed layer 131 and the second seed layer 132 that can suitably control the orientation of the piezoelectric layer 563.

[0074] The first seed layer 131 and the second seed layer 132 preferably contain Bi, Fe, Ti, and Pb, respectively. This allows the seed layer 130 to be constructed with a composite oxide having a perovskite structure, thereby suitably improving the orientation of the piezoelectric layer 563.

[0075] When both the first seed layer 131 and the second seed layer 132 are provided, the second seed layer 132 is present in both the first region A1 and the second region A2. As a result, both the first region A1 and the second region A2 are preferentially oriented to the (100) plane, and the orientation states of the first region A1 and the second region A2 are very similar to each other. Thus, when both the first seed layer 131 and the second seed layer 132 are provided, the first region A1 and the second region A2 preferentially oriented to the same crystal plane orientation.

[0076] In contrast, if only the first seed layer 131 is provided, the first seed layer 131 is present only in the second region A2. As a result, the second region A2 preferentially aligns to the (100) plane, while the first region A1 does not preferentially align to the (100) plane. Furthermore, in this case, the difference in orientation between the first region A1 and the second region A2 is significant.

[0077] 1-4: Method for manufacturing a liquid dispensing head Figures 7 and 8 are explanatory diagrams of a method for manufacturing the liquid discharge head 50 according to an embodiment. The method for manufacturing the liquid discharge head 50 is as shown in Figures 7 and 8, and steps ST1 to ST7 are carried out in this order. Each step will be described below in order.

[0078] Step ST1 involves applying a layer 561A, which is made of the material for the first electrode 561, onto the diaphragm 550. More specifically, in step ST1, for example, after forming the diaphragm 550, a bonding layer 140A is uniformly formed on the second layer 552 by sputtering a metal such as titanium, and then a layer 561A is uniformly formed on the bonding layer 140A by sputtering a metal such as platinum.

[0079] Step ST2 involves applying a layer 131A, formed from the material of the first seed layer 131, onto a layer 561A, formed from the material of the first electrode 561, after step ST1. More specifically, step ST2 forms layer 131A, which is a precursor layer of the first seed layer 131, by applying a solution such as a MOD solution containing the precursor material of the first seed layer 131 onto layer 561A using a spin coating method or the like.

[0080] Step ST3 involves heat-treating layer 131A, which is formed from the material of the first seed layer 131, after step ST2. More specifically, in step ST3, for example, layer 131A, which is the precursor layer of the first seed layer 131, is dried and degreased at approximately 350°C using an oven or the like, and then heat-treated at approximately 750°C for approximately 5 minutes using RTA (rapid thermal annealing) or the like. This forms layer 131B, in which the precursor constituting layer 131A is crystallized by firing. Note that the conditions for the heat treatment are not limited to the above example and can be changed as appropriate.

[0081] Step ST4, after step ST3, patterns layer 561A, formed from the material of the first electrode 561, and layer 131B, formed from the material of the first seed layer 131. More specifically, step ST4 patterns layer 561A and layer 131B together using known processing techniques such as photolithography and etching. This forms the patterned first electrode 561 and the patterned first seed layer 131. At this time, the adhesion layer 140A is patterned, thereby forming the adhesion layer 140.

[0082] Step ST5, after step ST4, coats layer 132A, which is made of the material for the second seed layer 132, onto the diaphragm 550 and the first seed layer 131 (a layer made of the material for the first seed layer 131). More specifically, step ST5 forms layer 132A, which is a precursor layer for the second seed layer 132, by applying a solution such as a MOD solution containing the precursor material for the second seed layer 132 across the diaphragm 550 and the first seed layer 131 using a spin coating method or the like.

[0083] Step ST6, after step ST5, heat-treats layer 132A, which is formed from the material of the second seed layer 132. More specifically, in step ST6, for example, layer 132A, which is the precursor layer of the second seed layer 132, is dried and degreased at about 350°C in an oven or the like, and then heat-treated at about 750°C for about 5 minutes using an RTA or the like. This forms the second seed layer 132, in which the precursor constituting layer 132A is crystallized by firing. Note that the conditions for the heat treatment are not limited to the example above and can be changed as appropriate. Also, the conditions such as temperature and time for the heat treatment in step ST6 may be the same as or different from the conditions for the heat treatment in step ST3.

[0084] Step ST7 involves applying a piezoelectric material onto the second seed layer 132 (a layer formed from the material of the second seed layer 132) after step ST6. More specifically, in step ST7, for example, a precursor layer of the piezoelectric layer 563 is formed by applying a solution such as a MOD solution containing a piezoelectric precursor material onto the second seed layer 132 using a spin coating method or the like. After that, the precursor layer is dried and degreased at approximately 350°C in an oven or the like, and then heat-treated at approximately 750°C for approximately 5 minutes using an RTA or the like. This forms the piezoelectric layer 563. Note that the application and heat treatment of the piezoelectric material may be performed in multiple steps. Furthermore, the conditions for the heat treatment are not limited to the above example and can be changed as appropriate.

[0085] After step ST7 described above, the piezoelectric layer 563 is patterned by known processing techniques such as photolithography and etching, although not shown in the diagram. At this time, a portion of the second seed layer 132 is also removed by patterning so that its planar shape matches the planar shape of the piezoelectric layer 563. This yields the piezoelectric element 560. Subsequently, the liquid discharge head 50 is obtained through appropriate known processes. Note that the patterning of the piezoelectric layer 563 is performed, for example, after the formation of the pressure chamber C1 on the pressure chamber substrate 520.

[0086] In the above method for manufacturing the liquid discharge head 50, the heat treatment in step ST3 is performed before the patterning in step ST4. During this heat treatment, diffusible materials such as Ti in the layers such as the adhesion layer 140A directly below the layer 561A cannot diffuse laterally but diffuses in the thickness direction. Therefore, during this heat treatment, the materials of the layers such as the adhesion layer 140A do not precipitate in a concentrated area. Furthermore, after the patterning in step ST4, a heat treatment for the second seed layer 132 is performed in step ST6, but by the time of this heat treatment, the diffusible materials in the layers such as the adhesion layer 140 have already diffused completely in step ST3. Therefore, during this heat treatment, the materials of the layers such as the adhesion layer 140 do not precipitate in a concentrated area at the end of the first electrode 561. As a result, the occurrence of cracks caused by localized segregation of the materials in the layers such as the adhesion layer 140 can also be reduced.

[0087] The effects of the above manufacturing method will be explained below in comparison with Comparative Examples 1 and 2.

[0088] (Comparative Example 1) Figure 9 is an explanatory diagram of the manufacturing method of the liquid discharge head 50X according to Comparative Example 1. The liquid discharge head 50X is configured in the same way as the liquid discharge head 50, except that it is equipped with a seed layer 130X instead of the seed layer 130. The seed layer 130X is configured in the same way as the seed layer 130, except that the first seed layer 131 is omitted. That is, the seed layer 130X is composed only of the second seed layer 132.

[0089] The manufacturing method for the liquid discharge head 50X is as shown in Figure 9, and steps ST2X to ST5X are carried out in that order. Each step will be described below in order. In the following, the same matters as in the manufacturing method of the liquid discharge head 50 will be reused or omitted as appropriate.

[0090] Step ST2X, following step ST1 described above, patterns the layer 561A formed from the material of the first electrode 561. This forms the first electrode 561, which consists of the patterned first electrode 561 and the adhesion layer 140.

[0091] Step ST3X involves applying a layer 132A, formed from the material of the second seed layer 132, onto the diaphragm 550 and the first electrode 561, after step ST2X.

[0092] In step ST4X, after step ST3X, layer 132A, which is formed from the material of the second seed layer 132, is heat-treated. This forms a seed layer 130X, which is formed by crystallizing the precursor layer 132A through firing.

[0093] Step ST5X involves applying a piezoelectric material onto the seed layer 130X after step ST4X. This forms the piezoelectric layer 563.

[0094] In the above method for manufacturing the liquid discharge head 50X, during the heat treatment in step ST4X, diffusible materials such as Ti from the materials of the layers such as the adhesion layer 140 diffuse to other layers. However, the first electrode 561 (especially the Ir contained in the first electrode 561) has properties that make it difficult for Ti to diffuse. For this reason, during the heat treatment in step ST4X, the first electrode 561 is positioned above the adhesion layer 140, so materials such as Ti do not easily advance above the adhesion layer 140. However, since the patterning in step ST2X is performed before the heat treatment in step ST4X, there is nothing on the edge of the first electrode 561 (especially the tapered portion of region X) that suppresses the diffusion of Ti during the heat treatment in step ST4X. Therefore, during the heat treatment in step ST4X, Ti and other materials segregate near the edge of the first electrode 561. When localized segregation of Ti or other materials occurs, it forms oxides such as TiOx, which can cause floating-like structures to form on the piezoelectric material at the end of the first electrode 561, potentially leading to cracking.

[0095] (Comparative Example 2) Figure 10 is an explanatory diagram of the manufacturing method of the liquid discharge head 50Y according to Comparative Example 2. The liquid discharge head 50Y is configured in the same way as the liquid discharge head 50, except that it is equipped with a seed layer 130Y instead of the seed layer 130. The seed layer 130Y is configured in the same way as the seed layer 130, except that the second seed layer 132 is omitted. That is, the seed layer 130Y is composed only of the first seed layer 131.

[0096] The manufacturing method for the liquid discharge head 50Y is as shown in Figure 10, with steps ST5Y and ST6Y performed in that order. Each step will be described below in order. Note that, in the following, the same explanations as those for the manufacturing method of the liquid discharge head 50 will be reused or omitted as appropriate.

[0097] Step ST5Y involves performing steps ST1 through ST4 described above to form a patterned first electrode 561 and a patterned first seed layer 131, which is a seed layer 130Y.

[0098] In step ST6Y, following step ST5Y, a piezoelectric material is applied to the diaphragm 550 and the seed layer 130Y. This forms the piezoelectric layer 563.

[0099] In the above method for manufacturing the liquid discharge head 50Y, the first electrode 561 and seed layer 130Y are formed by performing steps ST1 to ST4, so, similar to the method for manufacturing the liquid discharge head 50, segregation of materials such as Ti in layers such as the adhesion layer 140A is eliminated. The mechanism is thought to be as described in the above-mentioned method for manufacturing the liquid discharge head 50. That is, at the time of the heat treatment in step ST3, the patterning of layer 561A has not been performed, so layer 561A is formed over the entire area on the upper side of the material such as Ti that is trying to diffuse, and there is no escape route for the material such as the tapered portion of region F3 in Comparative Example 1. Therefore, even if layer 131A is heat-treated in step ST3, segregation of materials such as Ti in specific regions as in Comparative Example 1 does not occur, and most of it is absorbed into the diaphragm 550 (more specifically ZrO X The material then passes through to the second layer 552), which is composed of the same elements. This makes it possible to suppress segregation of Ti and other elements at the ends of the first electrode 561.

[0100] However, in Comparative Example 2, the seed layer 130Y cannot be provided in the non-active portion. As a result, the orientation of the piezoelectric layer 563 differs significantly between the active and non-active portions, causing cracks to occur at the boundary between them.

[0101] In contrast, in the manufacturing method of the liquid discharge head 50 shown in Figures 7 and 8, the second seed layer 132 is arranged across both the active and inactive parts, so that the orientation of the piezoelectric layer 563 can be controlled in both the active and inactive parts. Therefore, the occurrence of cracks caused by differences in the orientation of the piezoelectric layer 563 between the active and inactive parts can be reduced.

[0102] In Comparative Example 1, it is conceivable to perform a heat treatment between steps ST1 and ST2X solely to allow the material such as Ti in the adhesion layer 140 to fully diffuse. However, in that case, the heat treatment would be performed with layer 561A exposed, resulting in a rough surface of layer 561A. This would lead to a decrease in the orientation of the piezoelectric layer 563 due to a deterioration in the properties of the seed layer 130X. In contrast, in step ST3, the heat treatment is performed with the surface of layer 561A protected by layer 131A, so such problems do not occur, and the material such as Ti in the adhesion layer 140 diffuses completely without segregation.

[0103] 2: Variant Each of the forms exemplified above can be modified in various ways. Specific examples of modifications that can be applied to each of the aforementioned forms are given below. Any form selected from the following examples can be combined as appropriate, provided they do not contradict each other.

[0104] 2-1: Variation 1 In the embodiments described above, an example is shown in which the second electrode 562 is a common electrode. However, the embodiment is not limited to this example, and the second electrode 562 may be an individual electrode for each piezoelectric element 650. In this case, the first electrode 561 may be a common electrode common to multiple piezoelectric elements 560. However, even when the first electrode 561 is a common electrode and the second electrode 562 is an individual electrode, the piezoelectric layer 563 includes a region that does not overlap with the first electrode 561.

[0105] 2-2: Variation 2 In the embodiments described above, a serial-type liquid dispensing device 100 was exemplified, in which a transporter 41 equipped with a liquid dispensing head 50 is moved back and forth. However, this disclosure also applies to a line-type liquid dispensing device in which multiple nozzles N are distributed across the entire width of the recording medium M.

[0106] 2-3: Variation 3 The liquid dispensing device 100 exemplified in the above-described form may be used in various devices such as facsimile machines and photocopiers, in addition to equipment dedicated to printing, and the applications of this disclosure are not particularly limited. However, the applications of the liquid dispensing device are not limited to printing. For example, a liquid dispensing device that dispenses a colorant solution can be used as a manufacturing device for forming color filters for display devices such as liquid crystal display panels. A liquid dispensing device that ejects a conductive material solution can be used as a manufacturing device for forming wiring and electrodes on a wiring board. A liquid dispensing device that ejects a solution of organic matter related to living organisms can be used, for example, as a manufacturing device for producing biochips. [Explanation of symbols]

[0107] 10...Liquid container, 20...Control module (control unit), 30...Transport mechanism, 40...Moving mechanism, 41...Transport body, 42...Transport belt, 50...Liquid discharge head, 50X...Liquid discharge head, 50Y...Liquid discharge head, 100...Liquid discharge device, 110...First wiring, 120...Second wiring, 121...Conductive layer, 122...Conductive layer, 130...Seed layer, 130X...Seed layer, 130Y...Seed layer, 1 31...First seed layer, 131A...Layer, 131B...Layer, 132...Second seed layer, 132A...Layer, 140...Adhesion layer, 140A...Adhesion layer, 510...Communicating substrate, 520...Pressure chamber substrate, 530...Nozzle plate, 540...Vibration absorber, 550...Diaphragm, 551...First layer, 552...Second layer, 560...Piezoelectric element, 561...First electrode, 561A...Layer, 561b...Adhesion layer, 562...Second electrode, 5 63...Piezoelectric layer, 570...Protective substrate, 580...Case, 590...Wiring board, 600...Drive circuit, 650...Piezoelectric element, A1...First region, A2...Second region, A3...Third region, C1...Pressure chamber, Com...Drive signal, F1...Region, F2...Region, F3...Region, FN...Nozzle surface, G...Notch, HL...Inlet, Ln1...First nozzle row, Ln2...Second nozzle row, M...Recording medium, N...Nozzle Na...communication channel, R...reservoir, R1...channel, R2...channel, Ra...supply channel, S...space, SI...control signal, ST1...process, ST2...process, ST2X...process, ST3...process, ST3X...process, ST4...process, ST4X...process, ST5...process, ST5X...process, ST5Y...process, ST6...process, ST6Y...process, ST7...process, a...thickness, b...thickness, c...thickness, α...part.

Claims

1. A pressure chamber substrate having a plurality of pressure chambers arranged in a first direction, A diaphragm placed on the pressure chamber substrate, A first electrode placed on the diaphragm, A piezoelectric layer disposed on the first electrode, A second electrode disposed on the piezoelectric layer, A liquid dispensing head having a seed layer located between the piezoelectric layer and the diaphragm for controlling the orientation of the piezoelectric layer, The piezoelectric layer has a first region that does not overlap with the first electrode in the first direction, and a second region that overlaps with the first electrode in the first direction. The aforementioned seed layer, A first seed layer is not located in the first region but is located in the second region, A liquid dispensing head characterized by comprising a second seed layer provided on the first seed layer and positioned across both the first and second regions.

2. The thickness of the first seed layer in the second region is a, The thickness of the second seed layer in the second region is b, When the thickness of the second seed layer in the first region is c, The liquid dispensing head according to claim 1, characterized in that a + b > c.

3. The thickness of the second seed layer in the second region is b, When the thickness of the second seed layer in the first region is c, The liquid dispensing head according to claim 1, characterized in that b < c.

4. The thickness of the first seed layer in the second region is a, The thickness of the second seed layer in the second region is b, When the thickness of the second seed layer in the first region is c, The liquid dispensing head according to claim 1, characterized in that b < a < c and a + b > c.

5. The liquid dispensing head according to claim 1, characterized in that the first seed layer and the second seed layer are each in contact with the first electrode in at least a portion thereof.

6. The liquid dispensing head according to claim 1, characterized in that the first seed layer and the second seed layer are made of the same material.

7. The liquid dispensing head according to claim 1, characterized in that the first seed layer and the second seed layer each contain Ti.

8. The liquid dispensing head according to claim 1, characterized in that the first seed layer and the second seed layer each contain Bi, Fe, Ti, and Pb.

9. The liquid dispensing head according to claim 1, characterized in that the first electrode contains Ir.

10. The liquid dispensing head according to claim 1, characterized in that the piezoelectric layer contains K, Na, and Nb.

11. The first region is a region that is stacked on top of a region of the upper surface of the diaphragm that is flat along the first direction, The liquid dispensing head according to claim 1, characterized in that the second region is a region stacked on top of a region of the upper surface of the first electrode that is flat along the first direction.

12. The piezoelectric layer further includes a third region located between the first region and the second region in the first direction, The liquid dispensing head according to claim 11, characterized in that the third region is stacked on a region of the upper surface of the first electrode that is inclined with respect to the first direction.

13. The first seed layer is not located in the third region. The liquid dispensing head according to claim 12, characterized in that the second seed layer is also arranged in the third region.

14. A liquid dispensing head according to any one of claims 1 to 13, A liquid dispensing device characterized by having a control unit that controls the dispensing operation from the liquid dispensing head.

15. A method for manufacturing a liquid discharge head, comprising a pressure chamber substrate having a plurality of pressure chambers arranged in a first direction, and a diaphragm disposed on the pressure chamber substrate, A step of applying a layer formed of the material of the first electrode onto the diaphragm, A step of coating a layer formed of the material of the first seed layer onto a layer formed of the material of the first electrode, A step of heat-treating a layer formed from the material of the first seed layer, A step of patterning a layer formed from the material of the first electrode and a layer formed from the material of the first seed layer, A step of applying a layer formed of the material for the second seed layer onto the diaphragm and the layer formed of the material for the first seed layer, A step of heat-treating the layer formed from the material of the second seed layer, A method for manufacturing a liquid dispensing head, characterized by performing the steps in this order: applying a piezoelectric material onto a layer formed of the material of the second seed layer, and

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