Liquid dispensing head and recording device

Abstract

This reduces the possibility of deterioration occurring at the joint between the first and second members. [Solution] The liquid discharge head comprises a first member having a pressure chamber, a diaphragm located on the pressure chamber, and a piezoelectric element located on the diaphragm corresponding to the pressure chamber, and a second member located on the first member and having a supply passage capable of supplying liquid to the pressure chamber, wherein the first member is provided with an amorphous silicon layer, and the first part and the second member 3 are joined to each other via the amorphous silicon layer.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head and a recording apparatus.

Background Art

[0002] Patent Document 1 discloses a liquid ejection head that includes a first member having a pressure chamber, and a second member having a supply path capable of supplying liquid to the pressure chamber, wherein the first member and the second member are bonded to each other via a resin adhesive.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A liquid ejection head according to one aspect of the present disclosure includes: a first member having a pressure chamber, a vibration plate positioned over the pressure chamber, and a piezoelectric element positioned on the vibration plate corresponding to the pressure chamber; and a second member positioned over the first member and having a supply path capable of supplying liquid to the pressure chamber. The first member is provided with an amorphous silicon layer, and the first member and the second member are bonded to each other via the amorphous silicon layer.

Brief Description of the Drawings

[0005] [Figure 1] FIG. 1 is a side view schematically illustrating a printer according to a first embodiment. [Figure 2] FIG. 2 is a plan view schematically illustrating the printer according to the first embodiment. [Figure 3] FIG. 3 is a plan view schematically illustrating the liquid ejection head according to the first embodiment. [Figure 4] FIG. 4 is a side view of the liquid ejection head according to the first embodiment as viewed from A. [Figure 5]Figure 5 is a schematic plan view showing the first member, second member, and third member according to the first embodiment. [Figure 6] Figure 6 is a cross-sectional view along line II shown in Figure 5. [Figure 7] Figure 7 is a cross-sectional view along the line II-II shown in Figure 5. [Figure 8] Figure 8 is a plan view of the first member according to the first embodiment, showing the pressure chamber, liquid chamber, individual electrode wiring, common electrode wiring, and amorphous silicon layer extracted. [Figure 9] Figure 9 is a schematic plan view showing the first member according to the second embodiment. [Figure 10] Figure 10 is a cross-sectional view along the line III-III shown in Figure 9. [Modes for carrying out the invention]

[0006] Embodiments of the present invention will be described below with reference to the drawings.

[0007] Please note that the diagrams used in the following explanation are schematic, and the dimensions and proportions shown in the drawings do not necessarily correspond to reality. Even among multiple drawings showing the same configuration, the dimensions and proportions may not match each other in order to exaggerate the shape.

[0008] (First embodiment) Figure 1 is a schematic side view of the printer 10 according to this embodiment. Figure 2 is a schematic top view of the printer 10. The printer 10 is, for example, a color inkjet printer. For the sake of clarity, Figure 1 illustrates a three-dimensional Cartesian coordinate system including the X-axis, where the right direction of the paper is positive, and the Y-axis, where the back direction of the paper is positive. Such a Cartesian coordinate system is also shown in other drawings used in the explanation below.

[0009] Furthermore, in the following explanation, for convenience, the positive Z-axis direction may be referred to as "up." The X-axis direction is the direction in which the printing paper P is transported. Also, "viewing from above" means viewing from the Z-axis direction.

[0010] The configuration of the printer 10 according to this embodiment will be described with reference to Figures 1 and 2.

[0011] Figure 1 is a schematic side view showing a printer 10 including a liquid ejection head 1 according to this embodiment. Figure 2 is a schematic top view showing the printer 10. The printer 10 is, for example, a color inkjet printer.

[0012] As shown in Figure 1, the printer 10 includes a paper feed roller 101, a guide roller 102, a transport roller 103, a recovery roller 104, a head case 105, a frame 106, a liquid discharge head 1, a dryer 107, a sensor unit 108, and a control unit 109.

[0013] The control unit 109 controls the operation of the paper feed roller 101, guide roller 102, transport roller 103, recovery roller 104, head case 105, frame 106, liquid discharge head 1, dryer 107, and sensor unit 108.

[0014] The paper feed roller 101, guide roller 102, transport roller 103, and recovery roller 104 constitute a moving section that moves the printing paper P and the liquid discharge head 1 relative to each other. The printing paper P is an example of a recording medium. The moving section is controlled by the control unit 109. The printing paper P is transported from the paper feed roller 101, through two guide rollers 102A, onto a plurality of transport rollers 103. After that, the printing paper P is transported through two guide rollers 102B and two guide rollers 102C to the recovery roller 104.

[0015] The head case 105 accommodates the conveyance roller 103, the frame 106, and the liquid ejection head 1. The head case 105 is connected to the outside at a part such as a portion where the printing paper P enters and exits, and the rest is a space isolated from the outside. In the internal space of the head case 105, control factors such as temperature, humidity, and atmospheric pressure are controlled by the control unit 109 as needed.

[0016] The frames 106 are flat-plate shaped, and are positioned close above the printing paper P conveyed by the conveyance roller 103. Four frames 106 are positioned inside the head case 105 at predetermined intervals along the conveyance direction of the printing paper P. The number of frames 106 mounted on the printer 10 can be appropriately changed according to the printing target or printing conditions.

[0017] The liquid ejection head 1 has an elongated shape that is long in the vertical direction on the paper surface of Figure 2. As shown in Figure 2, five liquid ejection heads 1 are mounted on each frame 106. In each frame 106, the five liquid ejection heads 1 constitute a head module 100. In each frame 106, three of the liquid ejection heads 1 are arranged side by side along the direction intersecting the conveyance direction of the printing paper P, and the other two liquid ejection heads 1 are arranged one by one between the three liquid ejection heads 1 at positions shifted along the conveyance direction. In each frame 106, the respective liquid ejection heads 1 are arranged so as to overlap in the conveyance direction of the printing paper P. The number of liquid ejection heads 1 included in one frame 106 can be appropriately changed according to the printing target or printing conditions. The moving unit causes the printing paper P and the liquid ejection head 1 to move relative to each other by moving the printing paper P and the head module 100 relative to each other.

[0018] The liquid ejection head 1 according to the present embodiment is fixed to the printer 10. That is, the printer 10 is a line printer. Note that the printer 10 is not limited to a line printer, and may be a so-called serial printer that alternately performs an operation of ejecting liquid droplets while moving the liquid ejection head 1 in a direction intersecting the conveyance direction of the printing paper P, and the conveyance of the printing paper P.

[0019] The liquid ejection head 1 is controlled by the control unit 109 based on data such as images or characters, and ejects liquid toward the printing paper P. The distance between the liquid ejection head 1 and the printing paper P is, for example, approximately 0.5 to 20 mm.

[0020] The liquid ejection heads 1 belonging to one head module 100 are supplied with liquid of the same color, and the four head modules 100 can print with four colors of liquid. Each head module 100 may be provided with a reservoir substrate positioned over the five liquid ejection heads 1. Thereby, it is possible to supply liquid to the five liquid ejection heads 1 from the flow path included in the reservoir substrate. The colors of the liquid ejected from the liquid ejection heads 1 of each head module 100 are, for example, magenta, yellow, cyan, and black. By causing such liquid to land on the printing paper P, the printer 10 can print color images. Note that the types of liquid colors can be changed as appropriate. Further, the configuration may be such that the liquid ejection heads 1 belonging to one head module 100 are supplied with several types of color liquids, and one head module 100 can print with several types of color liquids.

[0021] Furthermore, in addition to printing colored liquids, the printer 10 may print a liquid such as a coating agent uniformly or in a patterned manner with the liquid ejection head 1 in order to perform surface treatment on the printing paper P. Note that the printer 10 may apply the coating agent from an unillustrated applicator instead of the liquid ejection head 1.

[0022] The dryer 107 dries the printing paper P. After passing through the two guide rollers 102B, the printing paper P is dried by the dryer 107. Drying in the dryer 107 makes it less likely for the overlapping printing paper P to stick together or for undried liquid to rub against each other when wound up by the recovery roller 104.

[0023] The sensor unit 108 includes a position sensor, a speed sensor, a temperature sensor, and the like. The control unit 109 can control each part of the printer 10 based on the information from each sensor.

[0024] The printer 10 may include a cleaning unit for cleaning the liquid ejection head 1. The cleaning unit cleans the liquid ejection head 1, for example, by wiping or capping.

[0025] The recording medium may be other than printing paper P, such as rolled cloth. The printer 10 may also transport the recording medium on a conveyor belt. In this way, the printer 10 can use sheet paper, cut cloth, wood, or tiles as the recording medium. Furthermore, the printer 10 may print wiring patterns for electronic equipment by ejecting a liquid containing conductive particles from the liquid ejection head 1. In addition, the printer 10 may produce chemical compounds by ejecting a predetermined amount of liquid chemical agent or a liquid containing a chemical agent from the liquid ejection head 1 towards a reaction vessel and allowing it to react.

[0026] The configuration of the liquid discharge head 1 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a schematic plan view showing the liquid discharge head 1 according to this embodiment. Figure 4 is a side view of the liquid discharge head 1 shown in Figure 3 as seen from A. Note that the two wavy lines shown in the vertical direction of the paper in Figure 3 represent omitted lines.

[0027] The liquid dispensing head 1 comprises a first member 2, a second member 3, a third member 4, and a fourth member 5.

[0028] The first member 2 comprises a single-crystal silicon substrate 20, a diaphragm 23 located on the single-crystal silicon substrate 20, and a plurality of piezoelectric elements 24 located on the diaphragm 23. The single-crystal silicon substrate 20 is located on the third member 4. The single-crystal silicon substrate 20 has a plurality of pressure chambers 21 and a plurality of liquid chambers 22 formed therein.

[0029] The multiple pressure chambers 21 are through-holes penetrating the single-crystal silicon substrate 20 in the Z-axis direction, and each is connected to a plurality of nozzles 41 provided on the third member 4. In this embodiment, each of the multiple pressure chambers 21 is physically connected to the plurality of nozzles 41, but is not limited to this. For example, each of the multiple pressure chambers 21 may be fluidly connected to the plurality of nozzles 41 via a flow path such as a descender. That is, "connected" is a concept that includes not only physical connections but also fluidly connected connections. The multiple pressure chambers 21 are located along the Y-axis direction. Also, when viewed from above, the multiple pressure chambers 21 are located such that their longitudinal direction is along the X-axis direction and their short direction is along the Y-axis direction. In this embodiment, the pressure chambers 21 have a substantially rectangular planar shape, but are not limited to this. For example, the pressure chambers 21 may have a rhombus or circular planar shape. Liquid is stored inside the pressure chambers 21. When pressure is applied to the liquid in the pressure chamber 21, the liquid is discharged to the outside as droplets from the nozzle 41.

[0030] The multiple liquid chambers 22 are through-holes that penetrate the single-crystal silicon substrate 20 in the Z-axis direction, and each is connected to one end of the multiple pressure chambers 21 in the longitudinal direction. Liquid chambers 22 connected to pressure chambers 21 located on the positive X-axis side are connected to the negative X-axis side end of the pressure chamber 21. Liquid chambers 22 connected to pressure chambers 21 located on the negative X-axis side are connected to the positive X-axis side end of the pressure chamber 21. In addition, liquid is stored in the liquid chambers 22, similar to the pressure chambers 21. When viewed from above, the liquid chambers 22 include a portion with a smaller width in the Y-axis direction, i.e., a smaller flow path width, compared to the pressure chambers 21, and therefore function as a so-called throttling.

[0031] The diaphragm 23 is located on a single-crystal silicon substrate 20. Examples of materials that make up the diaphragm 23 include Si and SiO2.

[0032] Multiple piezoelectric elements 24 are located on diaphragms 23 corresponding to multiple pressure chambers 21. Here, "corresponding" in this specification means, for example, in the relationship between two members, that when viewed from above, at least a portion of them overlaps, or when viewed in cross-section, at least a portion of them overlaps in the vertical direction. Multiple piezoelectric elements 24 are provided in a 1:1 relationship with multiple pressure chambers 21. By applying a voltage to the piezoelectric elements 24, the piezoelectric elements 24 are displaced. As the piezoelectric elements 24 are displaced, the diaphragms 23 located on the pressure chambers 21 are also displaced. As a result, pressure is applied to the liquid in the pressure chambers 21. This causes the liquid to be discharged from the pressure chambers 21 through the nozzles 41. Multiple piezoelectric elements 24 are not located on diaphragms 23 corresponding to multiple liquid chambers 22.

[0033] The second member 3 is located on the first member 2. The second member 3 has a predetermined thickness that is thicker than the first member 2 in the Z-axis direction, and has the function of supporting the first member 2. The second member 3 is provided with a plurality of supply passages 31. The second member 3 is made of single-crystal silicon.

[0034] The multiple supply passages 31 are through-holes that penetrate the second member 3 in the Z-axis direction, and each is connected to one of the multiple liquid chambers 22. Each of the multiple supply passages 31 is connected to one of the multiple pressure chambers 21 via the multiple liquid chambers 22. The supply passages 31 function as so-called throttling, similar to the liquid chambers 22. Furthermore, when viewed from above, the multiple supply passages 31 are located in the center of the second member 3 in the X-axis direction.

[0035] The third member 4 is equipped with a plurality of nozzles 41. The third member 4 is made of single-crystal silicon. The third member 4 is located below the first member 2. In this embodiment, the third member 4 has substantially the same shape as the first member 2 when viewed from above.

[0036] The multiple nozzles 41 are through holes that penetrate the third member 4 in the Z-axis direction. The multiple nozzles 41 are positioned along the Y-axis direction and form a nozzle group. The liquid discharge head 1 according to this embodiment has two nozzle groups: a nozzle group on the positive X-axis side and a nozzle group on the negative X-axis side. Although the liquid discharge head 1 according to this embodiment has two nozzle groups, it may have only one nozzle group or three or more nozzle groups. The two nozzle groups according to this embodiment are configured parallel to each other. The distance between the nozzles 41 in each nozzle group is 84.6 μm. In other words, the resolution of the nozzles 41 in the nozzle group is 300 dpi. The nozzles 41 of the nozzle group on the positive X-axis side are each positioned between the nozzles 41 of the nozzle group on the negative X-axis side in the Y-axis direction. In other words, the nozzles 41 of the nozzle group on the positive X-axis side and the nozzles 41 of the nozzle group on the negative X-axis side are offset from each other in the Y-axis direction, and the resolution of the nozzles 41 of the two nozzle groups combined is 600 dpi. The spacing between the nozzles 41 in each nozzle group may be set appropriately according to the resolution.

[0037] The fourth member 5 is located on the second member 3. In plan view, the fourth member 5 has substantially the same shape as the second member 3. The fourth member 5 is equipped with a common channel 51. The fourth member 5 is made of resin.

[0038] The common channel 51, when viewed from above, is located in the center of the fourth member 5 in the X-axis direction and is provided along the Y-axis direction. Therefore, the common channel 51 is located on and connected to multiple supply channels 31. Thus, the common channel 51 can supply liquid to multiple supply channels 31.

[0039] The pressure chamber 21, liquid chamber 22, supply passage 31, and common passage 51 are filled with liquid. Pressure is applied to the pressure chamber 21 by the piezoelectric element 24, which supplies liquid from the pressure chamber 21 to the nozzle 41, and liquid droplets are discharged from the nozzle 41. Liquid is also supplied to the pressure chamber 21 from the common passage 51 via the liquid chamber 22 and supply passage 31.

[0040] In the liquid discharge head 1 according to this embodiment, two constrictions, a liquid chamber 22 and a supply passage 31, are provided between each pressure chamber 21 and the common flow path 51. This reduces so-called crosstalk, where a pressure wave generated in one pressure chamber 21 propagates to the other pressure chamber 21 through the common flow path 51.

[0041] Figures 3 and 4 show an example of the configuration of the liquid discharge head 1, and may include other components besides those shown in Figures 3 and 4.

[0042] Furthermore, the common flow path 51 may have both a supply common flow path for supplying liquid to the pressure chamber 21 and a recovery common flow path for recovering liquid from the pressure chamber 21. This gives the liquid discharge head 1 a circulation function that recovers a portion of the liquid that was not discharged from the nozzle 41.

[0043] The flexible substrate 6 is located on the end of the first member 2 in the negative X-axis direction. The liquid discharge head 1 according to this embodiment has one flexible substrate 6, but is not limited to this. For example, the liquid discharge head 1 may have two or more flexible substrates 6. Here, one end of the flexible substrate 6 is electrically connected to the first member 2, and the other end of the flexible substrate 6 is drawn out above the second member 3 and the fourth member 5. The flexible substrate 6 is a flexible wiring board and has the function of transmitting a drive signal to the first member 2.

[0044] The drive IC 7 is mounted on the flexible circuit board 6. The drive IC 7 is electrically connected to the control unit 109. Therefore, the drive IC 7 generates a drive signal based on the signal sent from the control unit 109. Furthermore, the drive IC 7 outputs this drive signal to the piezoelectric element 24 via the flexible circuit board 6. This allows the drive IC 7 to control the drive of the liquid discharge head 1.

[0045] The first member 2, the second member 3, and the third member 4 will be described in detail with reference to Figure 5. Figure 5 is a schematic plan view showing the first member 2, the second member 3, and the third member 4 according to this embodiment. Figure 6 is a cross-sectional view along line II shown in Figure 5. Figure 7 is a cross-sectional view along line II-II shown in Figure 5. The two wavy lines shown vertically in Figure 5 represent omitted lines.

[0046] The first member 2 further comprises an insulator 2N, individual electrode wiring 25, common electrode wiring 26, a protective film 27, a bonding layer 28, and an amorphous silicon layer 29. In Figure 5, the bonding layer 28 and the amorphous silicon layer 29 are shown in gray.

[0047] The piezoelectric element 24 comprises a common electrode 241, a piezoelectric body 242, and individual electrodes 243. In this embodiment, the piezoelectric element 24 has the common electrode 241 located on the diaphragm 23, the piezoelectric body 242 located on the common electrode 241, and the individual electrodes 243 located on the piezoelectric body 242, but is not limited to this arrangement. For example, the order of the common electrode 241 and individual electrodes 243 relative to the diaphragm 23 may be reversed. Specifically, the individual electrodes 243, piezoelectric body 242, and common electrode 241 may be arranged on the diaphragm 23 in that order.

[0048] The common electrode 241 in this embodiment is provided in common to multiple pressure chambers 21, but is not limited to this. For example, the common electrode 241 may be provided individually corresponding to each pressure chamber 21. The thickness of the common electrode 241 may be 0.05 μm or more and 1 μm or less. The constituent material of the common electrode 241 may be a metallic material such as Pt.

[0049] In this embodiment, the piezoelectric element 242 is provided individually corresponding to each pressure chamber 21, but is not limited thereto. For example, the piezoelectric element 242 may be provided in common to multiple pressure chambers 21 when viewed from above. The piezoelectric element 242 is sandwiched between individual electrodes 243 and a common electrode 241. The thickness of the piezoelectric element 242 may be 1 μm or more and 10 μm or less. The constituent material of the piezoelectric element 242 may be, for example, Pb(Zr,Ti)O3 system, NaNbO3 system, BaTiO3 system, (BiNa)NbO3 system, BiNaNB5O 15 Examples include ferroelectric ceramic materials such as those found in the iodine system.

[0050] The individual electrodes 243 are provided individually, corresponding to each pressure chamber 21. Furthermore, the individual electrodes 243 have substantially the same shape as the piezoelectric element 242. The thickness of the individual electrodes 243 may be between 0.05 μm and 1 μm. The constituent material of the individual electrodes 243 may be, for example, a metallic material such as Pt.

[0051] In the piezoelectric element 242, the portion sandwiched between the individual electrodes 243 and the common electrode 241 is polarized in the thickness direction along the Z-axis. Therefore, for example, when a voltage is applied in the polarization direction of the piezoelectric element 242 by the individual electrodes 243 and the common electrode 241, the piezoelectric element 242 contracts in the direction along the diaphragm 23. This contraction is restricted by the diaphragm 23. As a result, the piezoelectric element 242 is displaced so as to become convex toward the pressure chamber 21. Along with the displacement of the piezoelectric element 242, the diaphragm 23 located on the pressure chamber 21 is also displaced. As a result, pressure is applied to the liquid in the pressure chamber 21. Due to the pressure applied to the pressure chamber 21, the liquid is discharged from the nozzle 41.

[0052] The insulator 2N is positioned to cover the diaphragm 23 and the common electrode 241. Furthermore, in a plan view, the insulator 2N is positioned to surround the individual electrodes 243. The thickness of the insulator 2N may be, for example, 0.1 μm or more and 1 μm or less. The constituent material of the insulator 2N may be, for example, SiO2.

[0053] Furthermore, the insulator 2N is positioned to cover the ends of each piezoelectric element 242 and the ends of each individual electrode 243. Here, the ends of each piezoelectric element 242 and the ends of each individual electrode 243 include the ends in the X-axis direction and the ends in the Y-axis direction. By covering the ends of each piezoelectric element 242, the insulator 2N can reduce the possibility of the piezoelectric element 242 peeling away from the individual electrode 243. By covering the ends of each individual electrode 243, the insulator 2N can reduce the possibility of the individual electrode 243 peeling away from the diaphragm 23. On the other hand, the insulator 2N is not located in the central part of the piezoelectric element 24 so as not to hinder the displacement of the piezoelectric element 24.

[0054] There are multiple individual electrode wirings 25. Each of the multiple individual electrode wirings 25 is electrically connected to each individual electrode 243. The number of individual electrode wirings 25 is the same as the number of piezoelectric elements 24. The individual electrode wirings 25 are drawn out from the X-axis negative end of each individual electrode 243 to the X-axis negative end of the first member 2. At the X-axis negative end of the first member 2, the individual electrode wirings 25 are electrically connected to the flexible substrate 6. As a result, the individual electrode 253 receives a drive signal from the drive IC 7 via the flexible substrate 6 and the individual electrode wirings 25.

[0055] The individual electrode wiring 25 is located on the insulator 2N. That is, by having the insulator 2N between the individual electrode wiring 25 and the common electrode 241, the possibility of electrical conductivity between the individual electrode wiring 25 and the common electrode 241 can be reduced. Furthermore, in this embodiment, the individual electrode wiring 25 passes over the insulator 2N, which is positioned to cover the end of the piezoelectric element 242, and connects to the individual electrode 243, thus reducing the possibility of electrical conductivity to the piezoelectric element 242.

[0056] The thickness of the individual electrode wiring 25 may be, for example, 0.1 μm or more and 1 μm or less. The constituent material of the individual electrode wiring 25 may be, for example, gold.

[0057] The common electrode wiring 26 is electrically connected to the common electrode 241. The common electrode wiring 26 is located on the common electrode 241 at its X-positive end. The common electrode wiring 26 is also drawn out from the portion located on the common electrode 241 to the X-negative end of the first member 2. The common electrode wiring 26 is drawn out to the X-negative end of the first member 2, passing through the Y-positive and Y-negative directions of the common electrode 241. At the X-negative end of the first member 2, the common electrode wiring 26 is electrically connected to the flexible substrate 6. As a result, the common electrode 241 is supplied with a ground potential from the drive IC 7 via the flexible substrate 6 and the common electrode wiring 26.

[0058] In this embodiment, the common electrode wiring 26 is located on the insulator 2N except for the portion located on the common electrode 241. Although the common electrode wiring 26 in this embodiment is located on the insulator 2N, it may also be located directly on the diaphragm 23. The thickness of the common electrode wiring 26 may be, for example, 0.1 μm or more and 1 μm or less. The constituent material of the common electrode wiring 26 is, for example, Au.

[0059] The protective film 27 is located on the insulator 2N, the individual electrode wiring 25, and the common electrode wiring 26. When viewed from above, the protective film 27 is not located at the end of the first member 2 on the negative X-axis side. As a result, the protective film 27 is not located on the individual electrode wiring 25 and the common electrode wiring 26 at the end of the first member 2 on the negative X-axis side, making it possible to connect the flexible substrate 6 to the individual electrode wiring 25 and the common electrode wiring 26.

[0060] Furthermore, the protective film 27 is positioned to cover the insulator 2N at the ends of each piezoelectric element 242 and the ends of each individual electrode 243. By covering the insulator 2N at the ends of each piezoelectric element 242, the protective film 27 can further reduce the possibility of the piezoelectric element 242 peeling off from the individual electrode 243. By covering the insulator 2N at the ends of each individual electrode 243, the protective film 27 can further reduce the possibility of the individual electrode 243 peeling off from the diaphragm 23. On the other hand, similar to the insulator 2N, the protective film 27 is not located in the center of the piezoelectric element 24 so as not to hinder the displacement of the piezoelectric element 24.

[0061] The thickness of the protective film 27 may be, for example, 0.1 μm or more and 1 μm or less. The constituent material of the protective film 27 may be, for example, SiN.

[0062] The bonding layer 28 is located on the protective film 27. Furthermore, when viewed from above, the bonding layer 28 is positioned to surround the multiple piezoelectric elements 24. Because the bonding layer 28 surrounds the multiple piezoelectric elements 24 when viewed from above, it is possible to seal the multiple piezoelectric elements 24. Alternatively, the bonding layer 28 may be positioned to individually surround each piezoelectric element 24 when viewed from above.

[0063] The thickness of the bonding layer 28 may be, for example, 2 μm or more and 10 μm or less. Examples of the constituent materials of the bonding layer 28 include SiO2 and SiN.

[0064] The amorphous silicon layer 29 is located on the bonding layer 28. The amorphous silicon layer 29 contains amorphous silicon. The amorphous silicon layer 29 may contain other atoms as impurities. In this embodiment, the amorphous silicon layer 29 is composed of at least 90% amorphous silicon. Amorphous silicon is non-crystalline silicon in which silicon atoms are randomly bonded to each other. In this embodiment, the amorphous silicon layer 29 overlaps the bonding layer 28 when viewed from above.

[0065] In this embodiment, the liquid discharge head 1 is formed on the bonding layer 28 by irradiating a second member 3, which is made of single-crystal silicon, with an Ar ion beam under high vacuum conditions, thereby scattering silicon atoms onto the bonding layer 28. Here, high vacuum conditions refer to 10 ―5 This refers to a vacuum level of Pa or less. Furthermore, "activated" means that silicon atoms have unbonded hands. In this embodiment, the liquid discharge head 1 is formed on the bonding layer 28 by irradiating the second member 3 with an Ar ion beam to scatter silicon atoms onto the bonding layer 28, but it is not limited to this. For example, the amorphous silicon layer 29 may be formed on the bonding layer 28 by irradiating a single crystal silicon other than the second member 3 with an Ar ion beam to scatter silicon atoms onto the bonding layer 28. In other words, other single crystal silicon may be used to form the amorphous silicon layer 29, not limited to the second member 3 used in the liquid discharge head 1.

[0066] The second member 3 is located on an amorphous silicon layer 29 and is joined to the first member 2. Specifically, under high vacuum, silicon atoms are scattered using the aforementioned Ar ion beam, which activates the surface of the second member 3. When the activated portion of the single-crystal silicon contained in the second member 3 is brought into contact with the activated amorphous silicon layer 29, the unbonded bonds of the amorphous silicon layer 29 and the unbonded bonds of the second member 3 bond together, and the first member 2 and the second member 3 are joined to each other.

[0067] In this embodiment, the liquid discharge head 1 is joined to the first member 2 and the second member 3 by bringing into contact the activated portion of the single-crystal silicon contained in the second member 3 with the activated amorphous silicon layer 29, but it is not limited to this. In this embodiment, the liquid discharge head 1 may also be joined to the first member 2 and the second member 3 by scattering silicon atoms in the second member 3 to form activated amorphous silicon, and then bringing the activated amorphous silicon into contact with the activated amorphous silicon layer 29 of the first member 2.

[0068] In this embodiment, the liquid dispensing head 1 has a first member 2 and a second member 3 joined to each other via an amorphous silicon layer 29. Amorphous silicon has excellent chemical stability, and its degradation due to the influence of liquid is slower than, for example, resins used in resin adhesives. Here, degradation due to the influence of liquid includes, for example, degradation due to hydrolysis, elution, or swelling. Furthermore, since resins have lower thermal stability than amorphous silicon, the possibility of degradation due to hydrolysis, elution, or swelling increases as the liquid temperature rises. Therefore, in this embodiment, since the first member 2 and the second member 3 are joined via an amorphous silicon layer 29 which has excellent chemical and thermal stability, the possibility of degradation occurring at the joint between the first member 2 and the second member 3 due to the influence of the supplied liquid can be reduced. In this embodiment, the liquid dispensing head 1 is constructed such that the first member 2 and the second member 3 are joined via an amorphous silicon layer 29. Therefore, when viewed from above, the joint between the first member 2 and the second member 3 overlaps with the amorphous silicon layer 29. Furthermore, amorphous silicon is less susceptible to deterioration due to oxidation compared to metals used in metal joining. As a result, the liquid dispensing head 1 in this embodiment can reduce the possibility of deterioration due to oxidation at the joint between the first member 2 and the second member 3.

[0069] In this embodiment, the liquid dispensing head 1 is joined to the first member 2 and the second member 3 by bringing into contact the activated portion of the single-crystal silicon contained in the second member 3 with the activated amorphous silicon layer 29. Alternatively, in this embodiment, the liquid dispensing head 1 is joined to the first member 2 and the second member 3 by scattering silicon atoms on the second member 3 to form activated amorphous silicon, and then bringing the activated amorphous silicon into contact with the activated amorphous silicon layer 29 of the first member 2. The first member 2 and the second member 3 can be joined at room temperature. Here, room temperature is defined as 5 to 35 degrees Celsius, and in this embodiment, the liquid dispensing head 1 is joined to the first member 2 and the second member 3 at 25 degrees Celsius. Therefore, since joining the first member 2 and the second member 3 does not require joining at high temperatures of 200 degrees Celsius or higher, such as by joining with a resin adhesive or metal diffusion bonding, the possibility of damage to the piezoelectric element 24, particularly the first member 2, due to exposure to high temperatures during joining can be reduced.

[0070] As described above, in this embodiment, the liquid discharge head 1 has an amorphous silicon layer 29 in which 90% or more is composed of amorphous silicon. Therefore, because the amorphous silicon layer 29 of the liquid discharge head 1 according to this embodiment contains fewer impurities, the possibility of deterioration occurring at the joint between the first member 2 and the second member 3 can be further reduced. Furthermore, in a liquid discharge head 1 in which 99% or more of the amorphous silicon layer 29 is composed of amorphous silicon, the possibility of deterioration occurring at the joint between the first member 2 and the second member 3 can be further reduced because there are even fewer impurities.

[0071] Furthermore, the diaphragm 23 has a through hole 231 at a position corresponding to the supply passage 31 when viewed from above. In other words, the diaphragm 23 has a through hole 231 at a position that overlaps with the supply passage 31 when viewed from above. Therefore, in the liquid discharge head 1 according to this embodiment, liquid can be supplied to the pressure chamber 21 from the supply passage 31 and the through hole 231. The joint between the first member 2 and the second member 3, located between the supply passage 31 and the through hole 231, is in contact with the liquid supplied to the pressure chamber 21 from the supply passage 31 and is therefore susceptible to the effects of the liquid. Therefore, in the liquid discharge head 1 according to this embodiment, the amorphous silicon layer 29 is positioned to surround the through hole 231 when viewed from above. As a result, in the liquid discharge head 1 according to this embodiment, the joint between the first member 2 and the second member 3 near the through hole 231 can be made less susceptible to the effects of the liquid supplied to the pressure chamber 21 from the supply passage 31 and the through hole 231.

[0072] The amorphous silicon layer 29 does not overlap with the pressure chamber 21 when viewed from above. Since the first member 2 and the second member 3 are joined via the amorphous silicon layer 29, the rigidity of the portion of the first member 2 that overlaps with the amorphous silicon layer 29 is increased. In the liquid discharge head 1 according to this embodiment, since the amorphous silicon layer 29 does not overlap with the pressure chamber 21 when viewed from above, the possibility of increased rigidity of the diaphragm 23 located on the pressure chamber 21 can be reduced. Therefore, the liquid discharge head 1 according to this embodiment can reduce the possibility of decreased displacement of the diaphragm 23 due to displacement of the piezoelectric element 24.

[0073] On the other hand, when viewed from above, the amorphous silicon layer 29 partially overlaps with the liquid chamber 22. The liquid chamber 22 is connected to the pressure chamber 21. Furthermore, the liquid chamber 22 is located between the supply passage 31 and the pressure chamber 21. In the liquid discharge head 1 according to this embodiment, because the amorphous silicon layer 29 partially overlaps with the liquid chamber 22, a portion of the amorphous silicon layer 29 is located on the liquid chamber 22. Because a portion of the amorphous silicon layer 29 is located on the liquid chamber 22, the rigidity of the diaphragm 23 on which the amorphous silicon layer 29 overlaps is increased. Therefore, the liquid discharge head 1 according to this embodiment can reduce the displacement of the diaphragm 23 on which the amorphous silicon layer 29 overlaps. In addition, the liquid chamber 22 includes a portion with a width smaller than the width of the pressure chamber 21. Therefore, the liquid discharge head 1 according to this embodiment can further reduce the displacement of the diaphragm 23 located on the liquid chamber 22. Therefore, the liquid discharge head 1 according to this embodiment is less likely to generate pressure waves in the liquid chamber 22, thus reducing fluid crosstalk.

[0074] Furthermore, the thickness of the amorphous silicon layer 29 may be, for example, 1 nm or more and 20 nm or less. By reducing the thickness of the amorphous silicon layer 29 to 20 nm or less, variations in the thickness of the amorphous silicon layer 29 can be reduced. Therefore, the liquid discharge head 1 according to this embodiment can reduce the possibility of poor bonding between the first member 2 and the second member 3 due to variations in the thickness of the amorphous silicon layer 29.

[0075] When viewed in cross-section, the amorphous silicon layer 29 is located above the piezoelectric element 24. In other words, when viewed in cross-section, the amorphous silicon layer 29 is located on the positive Z-axis side of the piezoelectric element 24. Specifically, when viewed in cross-section, the amorphous silicon layer 29 is located on the positive Z-axis side of the individual electrodes 243 of the piezoelectric element 24. In this embodiment, because the amorphous silicon layer 29 is located above the piezoelectric element 24 when viewed in cross-section, the liquid discharge head 1 can reduce the possibility of the second member 3 located on the amorphous silicon layer 29 coming into contact with the piezoelectric element 24. Therefore, the liquid discharge head 1 in this embodiment can reduce the possibility of hindering the displacement of the piezoelectric element 24.

[0076] In the liquid discharge head 1 according to this embodiment, since the amorphous silicon layer 29 is located on the bonding layer 28, even if the thickness of the amorphous silicon layer 29 is relatively small, the thickness can be ensured by the bonding layer 28. In the liquid discharge head 1 according to this embodiment, the thickness of the bonding layer 28 is greater than the thickness of the amorphous silicon layer 29. In the liquid discharge head 1 according to this embodiment, since the amorphous silicon layer 29 is located on the bonding layer 28, for example, it becomes easy to form the amorphous silicon layer 29 above the piezoelectric element 24.

[0077] In the liquid discharge head 1 according to this embodiment, the upper surface of the bonding layer 28 is located above the piezoelectric element 24 when viewed in cross-section. In other words, the upper surface of the bonding layer 28 is located on the positive Z-axis side of the piezoelectric element 24 when viewed in cross-section. As a result, the amorphous silicon layer 29 located on the bonding layer 28 is located above the piezoelectric element 24. Therefore, the liquid discharge head 1 according to this embodiment can reduce the possibility of hindering the displacement of the piezoelectric element 24 due to the second member 3 contacting the piezoelectric element 24.

[0078] The upper surface of the bonding layer 28 is a flat surface achieved by CMP (Chemical Mechanical Polishing). CMP is a polishing process that uses chemical and mechanical actions with a slurry containing chemicals and abrasive particles. Polishing methods such as chemical polishing, electrolytic polishing, buffing, and lapping may be used. In the liquid discharge head 1 according to this embodiment, since the upper surface of the bonding layer 28 is a flat surface, the amorphous silicon layer 29 located on the bonding layer 28 is similarly flattened. Therefore, the liquid discharge head 1 according to this embodiment can reduce bonding defects between the first member 2 and the second member 3. It is preferable that the height difference on the upper surface of the bonding layer 28 be smaller than the thickness of the amorphous silicon layer 29. Here, the height difference is the difference in position in the Z-axis direction when any point is taken on the upper surface of the bonding layer 28. It is preferable that the height difference on the upper surface of the bonding layer 28 be 20 nm or less.

[0079] The bonding layer 28 and the amorphous silicon layer 29 are positioned to surround the piezoelectric element 24 in a plan view. As described above, the constituent material of the bonding layer 28 contains SiO2 or SiN, and therefore has high moisture resistance, heat resistance, and insulation properties. For this reason, in the liquid discharge head 1 according to this embodiment, the piezoelectric element 24 can be sealed by the bonding layer 28 and the amorphous silicon layer 29 being positioned to surround the piezoelectric element 24 in a plan view. By sealing the piezoelectric element 24, the possibility of deterioration due to moisture and oxidation due to oxygen can be reduced.

[0080] In the liquid dispensing head 1 according to this embodiment, the bonding layer 28 and the amorphous silicon layer 29 are positioned surrounding a plurality of piezoelectric elements 24. Therefore, in the liquid dispensing head 1 according to this embodiment, the bonding layer 28 and the amorphous silicon layer 29 make it possible to seal the plurality of piezoelectric elements 24 together, allowing the plurality of piezoelectric elements 24 to be brought closer together compared to the case where each piezoelectric element 24 is enclosed individually. As a result, it is possible to miniaturize the liquid dispensing head 1.

[0081] The bonding layer 28 and the amorphous silicon layer 29 may be positioned to individually surround each of the plurality of piezoelectric elements 24. In a liquid discharge head configured such that the bonding layer 28 and the amorphous silicon layer 29 individually surround each of the plurality of piezoelectric elements 24, for example, the possibility of vibrations generated in one piezoelectric element 24 propagating to adjacent piezoelectric elements 24 can be reduced.

[0082] In this embodiment, the piezoelectric element 24 is located in a space A with an amorphous silicon layer 29 and a bonding layer 28 as its walls. That is, the piezoelectric element 24 in this embodiment is located in a space A that is independent of the outside of the liquid discharge head 1. In the liquid discharge head 1 in this embodiment, the atmospheric pressure in space A is set to be lower than the atmospheric pressure outside the liquid discharge head 1, for example, standard atmospheric pressure. Therefore, the piezoelectric element 24 in this embodiment has a reduced amount of oxygen in space A, which reduces the possibility of oxidation.

[0083] In the liquid discharge head 1 according to this embodiment, the atmospheric pressure in space A is 1 Pa or less, which is approximately 1 / 100,000th or less of the standard atmospheric pressure of 101,325 Pa. The atmospheric pressure in the independent space A can be reduced, for example, by joining the first member 2 and the second member 3 under vacuum. Furthermore, in the liquid discharge head 1 according to this embodiment, the first member 2 and the second member 3 are joined by the bonding of unbonded silicon bonds, that is, by covalent bonding. Therefore, in the liquid discharge head 1 according to this embodiment, a strong bonding force is generated at the joint between the first member 2 and the second member 3, resulting in high airtightness of the independent space A and making it easy to maintain the atmospheric pressure in the independent space A.

[0084] In the liquid discharge head 1 according to this embodiment, the lower surface 32 of the second member 3, which includes the portion that overlaps with the piezoelectric element 24 in a plan view, is located above the lower surface 33 of the portion that overlaps with the amorphous silicon layer 29 in a plan view. In other words, the lower surface 32 of the second member 3, which includes the portion that overlaps with the piezoelectric element 24 in a plan view, is located on the positive Z-axis side than the lower surface 33 of the portion that overlaps with the amorphous silicon layer 29 in a plan view. That is, in the liquid discharge head 1 according to this embodiment, the second member 3 forms a recess when viewed in cross-section. In the liquid discharge head 1 according to this embodiment, since the lower surface 32 of the second member 3, which includes the portion that overlaps with the piezoelectric element 24 in a plan view, is located above the lower surface 33 of the portion that overlaps with the amorphous silicon layer 29 in a plan view, the possibility of the second member 3 contacting the piezoelectric element 24 and hindering the displacement of the piezoelectric element 24 can be reduced.

[0085] The second member 3 in this embodiment contains single-crystal silicon. The surface of the single-crystal silicon can be activated using an Ar ion beam under high vacuum. By bringing the activated single-crystal silicon contained in the second member 3 into contact with the activated amorphous silicon layer 29, the first member 2 and the second member 3 can be joined to each other without high-temperature treatment. The first member 2 and the second member 3 can be joined to each other by a so-called room-temperature joining method. In the liquid discharge head 1 according to this embodiment, by joining the first member 2 and the second member 3 by a room-temperature joining method, the possibility of damage to the piezoelectric element 24 due to exposure to high temperatures, for example, can be reduced.

[0086] Referring to Figure 8, the relationship between the amorphous silicon layer 29 and the individual electrode wiring 25 and common electrode wiring 26 will be described in detail. Figure 8 is a plan view showing the pressure chamber 21, liquid chamber 22, individual electrode wiring 25, common electrode wiring 26, and amorphous silicon layer 29 in the first member 2 according to this embodiment. In Figure 8, the amorphous silicon layer 29 is shown in gray.

[0087] The individual electrode wiring 25, which is drawn out from the portion corresponding to the pressure chamber 21 on the positive X-axis side, is drawn out to the negative X-axis end of the first member 2, passing between the pressure chambers 21 on the negative X-axis side and between the liquid chambers 22 on the negative X-axis side.

[0088] When viewed from above, the amorphous silicon layer 29 partially overlaps with the individual electrode wiring 25. Therefore, in the liquid discharge head 1 according to this embodiment, the position where the amorphous silicon layer 29 partially overlaps with the individual electrode wiring 25 is held down by the second member 3, thereby reducing the possibility of peeling of the individual electrode wiring 25. Specifically, when viewed from above, the amorphous silicon layer 29 is positioned to overlap with the individual electrode wiring 25 located between the pressure chamber 21 on the positive X-axis side and the pressure chamber 21 on the negative X-axis side. Also, when viewed from above, the amorphous silicon layer 29 is positioned to overlap between the pressure chamber 21 on the negative X-axis side and the end of the first member 2 on the negative X-axis side.

[0089] Furthermore, when viewed from above, the amorphous silicon layer 29 partially overlaps with the common electrode wiring 26. Therefore, in the liquid discharge head 1 according to this embodiment, the position where the amorphous silicon layer 29 partially overlaps with the common electrode wiring 26 is held down by the second member 3, thereby reducing the possibility of peeling of the common electrode wiring 26. Specifically, when viewed from above, the amorphous silicon layer 29 is positioned to overlap with the common electrode wiring 26 except for the end on the negative X-axis side of the first member 2. That is, when viewed from above, the amorphous silicon layer 29 is positioned to overlap with the portion of the common electrode wiring 26 other than the portion that connects to the flexible substrate 6.

[0090] Next, we will explain how to manufacture the liquid dispensing head 1.

[0091] First, prepare a single-crystal silicon substrate.

[0092] A diaphragm 23, piezoelectric element 24, insulator 2N, individual electrode wiring 25, common electrode wiring 26, and protective film 27 are formed on a single-crystal silicon substrate by sputtering, sol-gel method, CVD method, or thermal oxidation method.

[0093] Next, SiO2, which will become the bonding layer 28, is formed on the protective film 27 by sputtering. The SiO2 is initially formed relatively thickly on the protective film 27. Subsequently, the SiO2 is reduced in thickness by grinding. Then, the upper surface of the SiO2 is flattened by CMP. The SiO2 flattened by polishing is the bonding layer 28. The thickness of the bonding layer 28 is approximately 2 μm after grinding and polishing. Note that polishing methods other than CMP may be used.

[0094] Next, the second member 3 is manufactured by forming a supply channel 31 in a single-crystal silicon substrate. The second member 3 is irradiated with an Ar ion beam, causing amorphous silicon to be scattered onto the bonding layer 28, thereby forming an amorphous silicon layer 29. When amorphous silicon is scattered using the aforementioned Ar ion beam under high vacuum, the surface of the second member 3 is activated.

[0095] Next, when the activated portion of the single-crystal silicon contained in the second member 3 is brought into contact with the activated amorphous silicon layer 29, the first member 2 and the second member 3 are joined together. Note that the Ar ion beam irradiation and the joining of the first member 2 and the second member 3 are performed under high vacuum and at room temperature.

[0096] Next, the pressure chamber 21 and the liquid chamber 22 are formed by etching the lower surface of the single-crystal silicon substrate of the first member 2.

[0097] Next, the third member 4 is manufactured by forming a nozzle 41 on a single-crystal silicon substrate. The lower surface of the first member 2 and the upper surface of the third member 4 are activated by irradiating them with an Ar ion beam under high vacuum. Subsequently, the lower surface of the first member 2 and the upper surface of the third member 4 can be joined by bringing them into contact at room temperature and under high vacuum. At this time, an amorphous silicon layer is formed between the first member 2 and the third member 4. In other words, the first member 2 and the third member 4 are joined to each other via the amorphous silicon layer.

[0098] Next, the fourth member 5 is manufactured by forming a common channel 51 in the resin member. The fourth member 5 is joined to the second member 3 via a resin adhesive.

[0099] Next, a flexible substrate 6 on which the drive IC 7 is mounted is prepared. The flexible substrate 6 on which the drive IC 7 is mounted is bonded to the first member 2 via adhesive so as to be electrically connected to the individual electrode wiring 25 and common electrode wiring 26 of the first member 2. This allows the liquid dispensing head 1 to be manufactured. Note that there are no limitations on the order of film formation or bonding.

[0100] (Second embodiment) A liquid discharge head 1a according to the second embodiment will now be described. In describing the liquid discharge head 1a according to this embodiment, basically only the differences from the liquid discharge head 1 according to the first embodiment will be described. Matters not specifically mentioned may be the same as in the first embodiment or can be inferred from the first embodiment.

[0101] Figure 9 is a schematic plan view showing the first member 2a according to the second embodiment. Figure 10 is a cross-sectional view along the line III-III shown in Figure 9. The two wavy lines shown vertically in Figure 9 represent omitted lines. In Figure 10, the second member 3 and the third member 4 are also shown.

[0102] In Figure 9, the bonding layer 28 and the first amorphous silicon layer 29a are shown in gray. Here, the first amorphous silicon layer 29a corresponds to the amorphous silicon layer 29 described in the first embodiment.

[0103] In this embodiment, the liquid discharge head 1a is formed on the bonding layer 28 by irradiating a second member 3, which is made of single-crystal silicon, with an Ar ion beam under high vacuum, thereby scattering silicon atoms onto the bonding layer 28.

[0104] The second member 3 is located on the first amorphous silicon layer 29a and is joined to the first member 2a. Specifically, under high vacuum, silicon atoms are scattered using the Ar ion beam described above, which activates the surface of the second member 3. When the activated portion of the single-crystal silicon contained in the second member 3 is brought into contact with the activated first amorphous silicon layer 29a, the unbonded hands of the first amorphous silicon layer 29a and the unbonded hands of the second member 3 bond together, and the first member 2a and the second member 3 are joined to each other.

[0105] In the liquid discharge head 1a according to this embodiment, the first member 2a and the second member 3 are joined to each other via a first amorphous silicon layer 29a, similar to the liquid discharge head 1 according to the first embodiment. Therefore, in the liquid discharge head 1a according to this embodiment, since the first member 2a and the second member 3 are joined via a first amorphous silicon layer 29a which has excellent chemical and thermal stability, the possibility of deterioration occurring at the joint between the first member 2a and the second member 3 due to the influence of the supplied liquid can be reduced. Furthermore, the liquid discharge head 1a according to this embodiment can also reduce the possibility of deterioration occurring at the joint between the first member 2a and the second member 3 due to oxidation.

[0106] The liquid discharge head 1a according to this embodiment differs from the liquid discharge head 1 according to the first embodiment in that it further has a second amorphous silicon layer 29b. The second amorphous silicon layer 29b is located on the piezoelectric element 24 and on the protective film 27. When viewed from above, the second amorphous silicon layer 29b is located in the portion excluding the portion having the first amorphous silicon layer 29a, and in the portion excluding the end on the negative X-axis side of the first member 2a. That is, when viewed from above, the second amorphous silicon layer 29b is located in the portion excluding the bonding layer 28, and in the portion excluding the end on the negative X-axis side of the first member 2a.

[0107] A first amorphous silicon layer 29a is formed on the bonding layer 28, and at the same time, the second member 3, which is single-crystal silicon, is irradiated with an Ar ion beam under high vacuum, causing amorphous silicon to be scattered onto the portion excluding the part having the first amorphous silicon layer 29a and the end on the negative X-axis side of the first member 2a, thereby forming a second amorphous silicon layer 29b.

[0108] The second amorphous silicon layer 29b, like the first amorphous silicon layer 29a, is non-crystalline silicon in which silicon atoms are randomly bonded to each other. The thickness of the second amorphous silicon layer 29b may be the same as the thickness of the first amorphous silicon layer 29a, for example, 1 nm to 20 nm or less.

[0109] In this embodiment, the second amorphous silicon layer 29b overlaps with the plurality of piezoelectric elements 24 when viewed from above. Therefore, the second amorphous silicon layer 29b in this embodiment functions as a protective film that protects the plurality of piezoelectric elements 24 from dust, moisture, and oxygen. Furthermore, because the silicon atoms of the second amorphous silicon layer 29b are randomly bonded together, it has a high resistance. In the liquid discharge head 1a according to this embodiment, the second amorphous silicon layer 29b is directly positioned on the plurality of piezoelectric elements 24. Therefore, in the liquid discharge head 1a according to this embodiment, the possibility of piezoelectric elements 24 conducting electrical circuits with other piezoelectric elements 24 via the second amorphous silicon layer 29b is reduced. In addition, because the thickness of the second amorphous silicon layer 29b is thin at 20 nm, the possibility of reduced displacement of the piezoelectric elements 24 can be reduced.

[0110] Furthermore, the second amorphous silicon layer 29b overlaps with the individual electrode wiring 25 when viewed from above. Therefore, in the liquid dispensing head 1a according to this embodiment, the second amorphous silicon layer 29b functions as a protective film that protects the individual electrode wiring 25 from dust, moisture, and oxygen. The second amorphous silicon layer 29b also functions as an insulator for the individual electrode wiring 25. Therefore, in the liquid dispensing head 1a according to this embodiment, the possibility of a short circuit is reduced even if moisture or ink enters between the individual electrode wiring 25 and other individual electrode wiring 25 or piezoelectric element 24.

[0111] Furthermore, the individual electrode wiring 25 drawn from the piezoelectric element 24 on the positive X-axis side passes between the piezoelectric elements 24 on the negative X-axis side and is drawn out to the negative X-axis side end of the first member 2a. The individual electrode wiring 25 located between the piezoelectric element 24 and the piezoelectric element 24 adjacent to it is close to the piezoelectric element 24 and therefore has a high possibility of short-circuiting. Therefore, in the liquid discharge head 1a according to this embodiment, the second amorphous silicon layer 29b, when viewed from above, overlaps with the individual electrode wiring 25 located between the piezoelectric element 24 and the piezoelectric element 24 adjacent to it, thereby reducing the possibility of short-circuiting. In addition, in the liquid discharge head 1a according to this embodiment, the individual electrode wiring 25 located between the piezoelectric element 24 and the piezoelectric element 24 adjacent to it is located, but any wiring, such as common electrode wiring, may be located there.

[0112] In this embodiment, the liquid discharge head 1a has a first amorphous silicon layer 29a located on a bonding layer 28. Therefore, even if the thickness of the first amorphous silicon layer 29a is relatively small, the bonding layer 28 can ensure sufficient thickness. The thickness of the bonding layer 28 is greater than the thickness of the first amorphous silicon layer 29a.

[0113] Furthermore, in the liquid dispensing head 1a according to this embodiment, the bonding layer 28 and the first amorphous silicon layer 29a are positioned surrounding the piezoelectric element 24 and the second amorphous silicon layer 29b. Therefore, the liquid dispensing head 1a according to this embodiment can seal the top of the piezoelectric element 24 with the second amorphous silicon layer 29b, and the area around the piezoelectric element 24 with the bonding layer 28 and the first amorphous silicon layer 29a. As a result, the liquid dispensing head 1a according to this embodiment can reduce the possibility of the piezoelectric element 24 being altered by moisture or oxidized by oxygen.

[0114] The first and second embodiments described above may be combined in any way as appropriate. [Explanation of Symbols]

[0115] 1, 1a Liquid dispensing head 2, 2a First member 21 Pressure Chamber 22 Liquid chamber 23 Diaphragm 231 Through hole 24 Piezoelectric elements 241 Common electrode 242 Piezoelectric 243 Individual electrodes 25 Individual electrode wiring 26 Common electrode wiring 28 Bonding layer 29 Amorphous silicon layer 29a First amorphous silicon layer 29b Second amorphous silicon layer 3. Second Member 31 Supply route 10. Printer (storage device) 109 Control Unit Space A

Claims

1. A first member having a pressure chamber, a diaphragm located on the pressure chamber, and a piezoelectric element located on the diaphragm corresponding to the pressure chamber, A second member is located on the first member and has a supply passage capable of supplying liquid to the pressure chamber, Equipped with, The first member is provided with an amorphous silicon layer, The first member and the second member are joined to each other via the amorphous silicon layer. Liquid dispensing head.

2. The diaphragm has a through hole at a position corresponding to the supply path, The amorphous silicon layer, when viewed from above, is positioned to surround the through-hole. The liquid dispensing head according to claim 1.

3. The first member further has a liquid chamber connected to the pressure chamber, The liquid chamber is located between the supply passage and the pressure chamber. When viewed from above, The liquid chamber includes a portion having a width smaller than the width of the pressure chamber. The amorphous silicon layer does not overlap with the pressure chamber, but overlaps with a portion of the liquid chamber. The liquid dispensing head according to claim 1.

4. The amorphous silicon layer is located above the piezoelectric element when viewed in cross-section. The liquid dispensing head according to claim 1.

5. The first member further has a bonding layer that is thicker than the thickness of the amorphous silicon layer, The amorphous silicon layer is located on the bonding layer, When viewed in cross-section, the upper surface of the bonding layer is located above the piezoelectric element. The liquid dispensing head according to claim 1.

6. The upper surface of the bonding layer is a flat surface. The liquid dispensing head according to claim 5.

7. The amorphous silicon layer and the bonding layer are positioned surrounding the piezoelectric element. The bonding layer is SiO ２ or containing SiN The liquid dispensing head according to claim 5.

8. The piezoelectric element is located in a space with the amorphous silicon layer and the bonding layer as walls. The atmospheric pressure in the aforementioned space is lower than standard atmospheric pressure. The liquid dispensing head according to claim 7.

9. The second member contains single-crystal silicon, The single-crystal silicon and the amorphous silicon layer contained in the second member are joined together. The liquid dispensing head according to claim 1.

10. The piezoelectric element comprises individual electrodes, a piezoelectric body, and a common electrode. The first member further has individual electrode wiring that is electrically connected to the individual electrodes, When viewed from above, the amorphous silicon layer partially overlaps with the individual electrode wiring. The liquid dispensing head according to claim 1.

11. The piezoelectric element comprises individual electrodes, a piezoelectric body, and a common electrode. The first member further has a common electrode wiring that is electrically connected to the common electrode, When viewed from above, the amorphous silicon layer partially overlaps with the common electrode wiring. The liquid dispensing head according to claim 1.

12. When the amorphous silicon layer is designated as the first amorphous silicon layer, The first member further has a second amorphous silicon layer that overlaps the piezoelectric element when viewed from above. The liquid dispensing head according to claim 1.

13. When the amorphous silicon layer is designated as the first amorphous silicon layer, The first member is, Wiring located between the piezoelectric element and an adjacent piezoelectric element, When viewed from above, a second amorphous silicon layer overlaps the wiring, It also has The liquid dispensing head according to claim 1.

14. The first member further has a bonding layer that is thicker than the thickness of the first amorphous silicon layer. The first amorphous silicon layer is located on the bonding layer, The upper surface of the bonding layer, when viewed in cross-section, is located above the piezoelectric element. The first amorphous silicon layer and the bonding layer are positioned surrounding the piezoelectric element and the second amorphous silicon layer. The liquid dispensing head according to claim 12.

15. A liquid dispensing head according to any one of claims 1 to 14, A moving unit that moves the liquid discharge head and the recording medium relative to each other, The system includes a control unit that controls the moving part. Recording device.

Images