Liquid discharge head and recording apparatus

Abstract

This liquid discharge head comprises a first pressure chamber, a second pressure chamber, a first portion, a diaphragm, wiring, and a second portion. The first pressure chamber and the second pressure chamber are adjacent to each other in a first direction. The first portion is positioned between the first pressure chamber and the second pressure chamber. The diaphragm is positioned above the first pressure chamber, above the first portion, and above the second pressure chamber. The wiring overlaps the first portion and extends in a second direction intersecting the first direction. The second portion includes a diaphragm positioned between the first portion and the wiring. When viewed in cross-section from a plane perpendicular to the second direction, the contour of the wiring has a first contour line in contact with the second portion, and a second contour line connected to both ends of the first contour line and having no corners.

Description

Liquid dispensing head and recording device

[0001] This disclosure relates to a liquid dispensing head and a recording device.

[0002] A liquid discharge head is known for discharging liquid toward a recording medium (see, for example, Patent Document 1). For example, in a liquid discharge head, a diaphragm is located above adjacent pressure chambers separated by a pressure chamber girder, a piezoelectric element is located above the diaphragm corresponding to each pressure chamber, and wiring drawn from individual electrodes provided on the piezoelectric element is located above the diaphragm corresponding to the pressure chamber girder.

[0003] Japanese Patent Publication No. 2012-196838

[0004] A liquid discharge head according to one aspect of the present disclosure comprises a first pressure chamber and a second pressure chamber, a first portion, a diaphragm, wiring, and a second portion. The first and second pressure chambers are adjacent in a first direction. The first portion is located between the first and second pressure chambers. The diaphragm is located above the first pressure chamber, above the first portion, and above the second pressure chamber. The wiring overlaps the first portion and extends in a second direction intersecting the first direction. The second portion includes the diaphragm located between the first portion and the wiring. When viewed in cross-section in a plane perpendicular to the second direction, the contour of the wiring has a first contour line tangent to the second portion and a second contour line connecting to both ends of the first contour line and having no corners.

[0005] Figure 1 is a schematic side view showing a printer according to an embodiment. Figure 2 is a schematic top view showing a printer according to an embodiment. Figure 3 is an exploded perspective view showing the schematic configuration of the liquid ejection head in steps. Figure 4 is an exploded perspective view showing the schematic configuration of the line head unit in steps. Figure 5 is a cross-sectional view along the line V-V shown in Figure 3. Figure 6 is a perspective view showing the schematic configuration of a part of the channel group in the MEMS chip. Figure 7 is a cross-sectional view showing the detailed configuration of the actuator substrate. Figure 8 is a schematic top view showing the actuator substrate. Figure 9 is a cross-sectional view along the line VIII-VIII shown in Figure 8. Figure 10 is a diagram showing an example of the outline of the lead wiring shown in Figure 9. Figure 11 is an enlarged view of region XI shown in Figure 8.

[0006] The following describes in detail, with reference to the drawings, embodiments for implementing the liquid discharge head and recording device according to this disclosure (hereinafter referred to as "Embodiments"). However, this disclosure is not limited by these embodiments. Furthermore, each embodiment can be combined as appropriate, provided that the processing content is not inconsistent. Also, the same parts are denoted by the same reference numerals in each of the following embodiments, and redundant descriptions are omitted.

[0007] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations such as manufacturing accuracy or installation accuracy.

[0008] Furthermore, in the drawings referenced below, for the sake of clarity, mutually orthogonal X, Y, and Z axis directions are sometimes defined, and a Cartesian coordinate system is shown with the positive Z axis pointing vertically upward.

[0009] (Embodiment) <Printer Configuration> First, an overview of the printer 100, which is an example of a recording device according to the embodiment, will be described with reference to Figures 1 and 2. Figure 1 is a schematic side view showing the printer 100 according to the embodiment. Figure 2 is a schematic top view showing the printer 100 according to the embodiment. The printer 100 according to the embodiment is, for example, a color inkjet printer.

[0010] As shown in Figure 1, the printer 100 includes a paper feed roller 101, guide rollers 102A to 102C, multiple transport rollers 103, a recovery roller 104, a head case 105, multiple frames 106, multiple liquid discharge heads 1, a dryer 107, and a coating machine 109. Furthermore, the printer 100 includes a sensor unit 108 and a control unit 200.

[0011] The control unit 200 controls the paper feed roller 101, guide rollers 102A to 102C, multiple transport rollers 103, recovery roller 104, head case 105, multiple frames 106, multiple liquid discharge heads 1, dryer 107, sensor unit 108, and coating machine 109.

[0012] The printer 100 records images or characters on the printing paper P by depositing droplets of liquid onto the paper P. The printing paper P is an example of a recording medium. Before use, the printing paper P is wound around the paper feed roller 101. The printer 100 then transports the printing paper P from the paper feed roller 101 to the inside of the head case 105 via the guide roller 102A and the coating machine 109.

[0013] The coating machine 109 uniformly applies the coating agent to the printing paper P. This allows the printing paper P to undergo surface treatment, thereby improving the print quality of the printer 100.

[0014] The head case 105 houses multiple transport rollers 103, multiple frames 106, and multiple liquid discharge heads 1. Inside the head case 105, a space is formed that is isolated from the outside, except for parts that are connected to the outside, such as the area where the printing paper P enters and exits.

[0015] The internal space of the head case 105 is controlled by the control unit 200, as needed, by at least one of the control factors such as temperature, humidity, and atmospheric pressure. The transport roller 103 transports the printing paper P to the vicinity of the liquid discharge head 1 inside the head case 105.

[0016] The frame 106 is a rectangular flat plate and is positioned close above the printing paper P being transported by the transport roller 103. Also, as shown in Figure 2, the frame 106 is positioned so that its longitudinal direction is perpendicular to the transport direction of the printing paper P. Inside the head case 105, multiple (for example, four) frames 106 are positioned along the transport direction of the printing paper P.

[0017] Liquid, such as ink, is supplied to the liquid ejection head 1 from a liquid tank (not shown). The liquid ejection head 1 ejects droplets supplied from the liquid tank.

[0018] The control unit 200 controls the liquid ejection head 1 based on data such as images or characters, and ejects droplets toward the printing paper P. The distance between the liquid ejection head 1 and the printing paper P is, for example, about 0.5 to 20 mm.

[0019] The liquid dispensing head 1 is fixed to the frame 106. The liquid dispensing head 1 is fixed to the frame 106, for example, at both ends in the longitudinal direction. The liquid dispensing head 1 is positioned so that its longitudinal direction is perpendicular to the transport direction of the printing paper P.

[0020] In other words, the printer 100 according to this embodiment is a so-called line printer in which the liquid ejection head 1 is fixed inside the printer 100. However, the printer 100 according to this embodiment is not limited to a line printer, and may be a so-called serial printer. A serial printer is a printer that alternately performs the operation of recording while moving the liquid ejection head 1 in a direction intersecting the transport direction of the printing paper P, for example, in a nearly perpendicular direction, and transporting the printing paper P.

[0021] As shown in Figure 2, a unit formed by arranging multiple (for example, eight) liquid discharge heads 1 on a single frame 106 is also called a Line Head Unit (LHU). Figure 2 shows an example of a Line Head Unit 1A in which four liquid discharge heads 1 are positioned in a staggered pattern in front of the printing paper P in the transport direction, and four are positioned behind it. The liquid discharge heads 1 are positioned so that the centers of each liquid discharge head 1 do not overlap in the transport direction of the printing paper P.

[0022] The line head unit 1A is composed of multiple liquid ejection heads 1 located on a single frame 106. The four line head units 1A are positioned along the transport direction of the printing paper P. Liquid ejection heads 1 belonging to the same line head unit 1A are supplied with ink of the same color. As a result, the printer 100 can perform printing with four colors of ink using the four line head units 1A. The four line head units 1A may be arranged side by side to form a carriage, which is one example of the final form of the liquid ejection head 1.

[0023] The ink colors ejected from each line head unit 1A are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 200 controls each line head unit 1A to eject multiple colors of ink onto the printing paper P, thereby enabling the printing of a color image on the paper P.

[0024] Furthermore, in order to treat the surface of the printing paper P, a coating agent may be dispensed onto the printing paper P from the liquid discharge head 1.

[0025] Furthermore, the number of liquid ejection heads 1 included in one line head unit 1A, or the number of line head units 1A installed in the printer 100, can be appropriately changed depending on the object to be printed or the printing conditions. For example, if the color to be printed on the printing paper P is a single color and the printing is limited to the area that can be printed with one liquid ejection head 1, then the number of liquid ejection heads 1 installed in the printer 100 may be as small as one.

[0026] The printed paper P, which has been processed inside the head case 105, is transported to the outside of the head case 105 by the transport roller 103, then transported by the guide roller 102B, and passes through the inside of the dryer 107. The dryer 107 dries the printed paper P. The printed paper P that has been dried in the dryer 107 is transported by the guide roller 102C and collected by the recovery roller 104.

[0027] In the printer 100, drying the printing paper P in the dryer 107 reduces the likelihood of the overlapping printing paper P sticking together or of undried liquid rubbing against each other in the recovery roller 104.

[0028] The sensor unit 108 is composed of a position sensor, a speed sensor, or a temperature sensor, etc. Based on the information from the sensor unit 108, the control unit 200 can determine the state of each part of the printer 100 and control each part of the printer 100.

[0029] The printer 100 described so far has shown the case where printing paper P is used as the printing target (i.e., recording medium), but the printing target in the printer 100 is not limited to printing paper P. For example, the printing target may be a roll of cloth or the like.

[0030] Alternatively, the printer 100 may transport the printing paper P on a conveyor belt instead of directly transporting it. By using a conveyor belt, the printer 100 can print on sheets of paper, cut cloth, wood, tiles, etc.

[0031] The printer 100 may also print wiring patterns for electronic devices by ejecting droplets containing conductive particles from the liquid ejection head 1. Alternatively, the printer 100 may produce chemical products by ejecting a predetermined amount of liquid chemical agent or droplets containing a chemical agent from the liquid ejection head 1 toward a reaction vessel or the like.

[0032] The printer 100 may also 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.

[0033] Wiping is a process that removes liquid adhering to the liquid discharge head 1 by wiping the surface of the area where the liquid droplets are discharged with a flexible wiper, for example.

[0034] Furthermore, the capping process is carried out, for example, as follows: First, a cap is placed over the surface of the area from which the droplets are dispensed (this is called capping). This creates a nearly sealed space between the surface of the area from which the droplets are dispensed and the cap.

[0035] Next, the droplets are repeatedly dispensed within this sealed space. This removes any liquid or foreign matter with a higher viscosity than standard that may have clogged the nozzle from which the droplets are dispensed.

[0036] <Configuration of the liquid discharge head in the line head unit> Next, the configuration of the liquid discharge head 1 and the line head unit 1A according to the embodiment will be described with reference to Figures 3 to 6. Figure 3 is an exploded perspective view showing the schematic configuration of the liquid discharge head 1 in steps. Figure 4 is an exploded perspective view showing the schematic configuration of the line head unit 1A in steps. Figure 5 is a cross-sectional view along the line V-V shown in Figure 3. Figure 6 is a perspective view showing the schematic configuration of a part of the channel group in the MEMS chip 10.

[0037] The liquid discharge head 1 is assembled in the order shown in Figures 3(a) to 3(c). The line head unit 1A is assembled in the order shown in Figures 4(a) and 4(b) using the eight liquid discharge heads 1 shown in Figure 3(c). As shown in Figure 3(a), the liquid discharge head 1 has a MEMS (Micro Electro Mechanical Systems) chip 10 and a COF substrate (Chip on Film) 11 on a film. One end of the MEMS chip 10 is bonded to one end of the COF substrate 11. As a result, as shown in Figure 3(b), the terminal 143 (see Figure 5) located at one end of the MEMS chip 10 is connected to the wiring (not shown) inside the COF substrate 11, thereby electrically connecting the MEMS chip 10 to the COF substrate 11. The MEMS chip 10 can also be referred to as an individual flow path member.

[0038] The COF substrate 11 mounts a drive IC 111. The drive IC 111 can communicate with the control unit 200 wirelessly or by wire. Accordingly, the drive IC 111 generates a drive signal based on the control signal transmitted from the control unit 200. Then, the drive IC 111 outputs the drive signal via the COF substrate 11 to an actuator substrate 3, which will be described later, in the MEMS chip 10. Thereby, the drive IC 111 can control the driving of the liquid ejection head 1.

[0039] Further, as shown in FIG. 3(b), the liquid ejection head 1 has a manifold member 12. The constituent material of the manifold member 12 may be metal or resin.

[0040] The manifold member 12 may have a layered structure of a plurality of plates, or may be a single layer of plate. Each plate has a base portion 12a and a protruding portion 12b. The protruding portion 12b is a portion that protrudes from the central region when the base portion 12a is divided into three in the longitudinal direction. The longitudinal direction of the base portion 12a is longer than the longitudinal direction of the MEMS chip 10. The manifold member 12 is joined to the MEMS chip 10 such that the base portion 12a is positioned over the MEMS chip 10. As a result, as shown in FIG. 3(c), an ultra-compact integrated module called a so-called Front End Module (FEM) is configured.

[0041] As an example of the layer structure of the manifold member 12, referring to FIG. 5 which shows a cross-section taken along the line V-V in FIG. 3(c), the manifold member 12 has a structure in which an uppermost plate 121a, an intermediate plate 121b, and a lowermost plate 121c are laminated in order from the top. The uppermost plate 121a has a filter 121f. The upper part of the filter 121f is connected to the reservoir flow path of the reservoir member 14 (see FIG. 4(b)). The filter 121f is located at the protruding portion 12b, and filters impurities in the liquid from the reservoir flow path. The uppermost plate 121a has a flow path 121 through which the impurity-filtered liquid flows. The lowermost plate 121c has a common flow path 123 along the longitudinal direction of the base portion 12a. The intermediate plate 121b is located between the uppermost plate 121a and the lowermost plate 121c, and has a hole 122 that communicates the flow path 121 of the uppermost plate 121a with the common flow path 123.

[0042] As shown in FIG. 4(a), eight front end modules (FEM) are arranged in a staggered pattern, and the eight manifold members 12 on the line are joined. As a result, the eight common flow paths 123 are positioned above the eight MEMS chips 10. Further, as shown in FIG. 4(b), a nozzle cover 13 that covers the eight MEMS chips 10 is joined below the eight MEMS chips 10. Thereby, the eight MEMS chips 10 are covered and protected by the nozzle cover 13. The longitudinal direction of the nozzle cover 13 is longer than the length of the eight manifold members 12. The nozzle cover 13 has eight rectangular openings 133. The openings 133 are located at positions corresponding to the eight nozzles 41 (see FIG. 5) of the eight MEMS chips 10, and allow liquid to be ejected from the eight nozzles 41.

[0043] Furthermore, the liquid discharge head 1 has a reservoir member 14 with a reservoir channel (not shown) inside. The longitudinal direction of the reservoir member 14 is longer than the length of the eight manifold members 12 on the line and is approximately equal to the length of the nozzle cover 13. The reservoir member 14 is joined to the eight manifold members 12 so as to be located above the eight manifold members 12. As a result, the reservoir channel is located on the common channel 123 of the eight manifold members 12.

[0044] The reservoir member 14 is, for example, an injection-molded product made of resin. Here, "made of resin" means made of resin, and includes resin which is the main component and contains a small amount of impurities. The reservoir member 14 may also be made of a conductive material such as metal. The reservoir member 14 distributes and supplies liquid from the reservoir channel to eight common channels 123.

[0045] Liquid supply ports 15 and liquid discharge ports 16 are located at both ends of the reservoir member 14 in the Y-axis direction. Liquid is supplied from the liquid supply ports 15 to the reservoir flow path within the reservoir member 14. The liquid discharge head 1 temporarily stores the liquid supplied to the reservoir member 14 in the reservoir flow path, supplies it to eight common flow paths 123 that branch off from the reservoir flow path, and discharges it from the nozzle 41 through the flow path in the MEMS chip 10 located below each common flow path 123. The liquid discharge head 1 discharges any liquid that was not supplied from the reservoir flow path of the reservoir member 14 to each common flow path 123 from the liquid discharge ports 16.

[0046] Furthermore, the liquid ejection head 1 may collect liquid from the liquid outlet 16 while printing is in progress. Doing so makes it less likely for air bubbles to accumulate in the reservoir flow path within the reservoir member 14. In addition, the temperature of the liquid ejection head 1 can be stabilized by supplying liquid adjusted to a constant temperature. The collected liquid may be passed through a filter or the like and then supplied back to the liquid ejection head 1. In other words, the liquid ejection head 1 may circulate the liquid. The supply and collection of liquid to and from the liquid ejection head 1, or the circulation of liquid, may be controlled by the control unit 200.

[0047] The above description shows an example of the configuration of the liquid discharge head 1. The configuration in Figure 4(b) may further include a circuit board, a heat sink for dissipating heat generated by the circuit board, cover members for the circuit board and heat sink, etc. For convenience, descriptions of these components have been omitted.

[0048] <Channel Group> The thickness direction of the MEMS chip 10 is defined as the Z-axis direction, and the positive Z-axis direction is defined as the vertically upward direction. The longitudinal direction (Y-axis direction) of the MEMS chip 10 is also called the row direction, and the short direction (X-axis direction) of the MEMS chip 10 is also called the column direction. In the example in Figure 5, the MEMS chips 10 located on both sides of line L show cross-sections of two channels arranged symmetrically with respect to line L.

[0049] A channel refers to a single unit configuration that includes a flow path extending from the supply path 51 through the connecting passage 52 and pressure chamber 131 to the nozzle 41, an actuator 30, and a diaphragm 38. A group of channels arranged in rows of 500 and in columns of two is called a channel group 10a or 10b. Channel groups 10a and 10b are arranged symmetrically with respect to line L shown in Figure 5. However, the number of channel groups can be changed as appropriate.

[0050] The MEMS chip 10 has a substrate in which a support substrate 2, an actuator substrate 3, and a nozzle substrate 4 are stacked from top to bottom. However, the three substrates, the support substrate 2, the actuator substrate 3, and the nozzle substrate 4, may be integrated into a single unit. Alternatively, only the two substrates, the actuator substrate 3 and the nozzle substrate 4, may be integrated into a single unit.

[0051] The support substrate 2 has a supply passage 51. The actuator substrate 3 has a bonding layer 3a and a pressure chamber substrate 3b stacked from top to bottom. The bonding layer 3a has a communication passage 52, an actuator 30, and a diaphragm 38. The diaphragm 38 is positioned on the lower surface of the actuator 30. The area around the actuator 30, other than the lower surface, is covered by a space 132. The area around the actuator 30, other than the lower surface, is covered by a space 132. The pressure chamber substrate 3b has a pressure chamber 131. The nozzle substrate 4 has nozzles 41 for discharging liquid. The pressure chambers 131 are arranged in a row of 100 to 2000 units and in a column of 2 units, for a total of 200 to 4000 units. Corresponding to the pressure chambers 131, there are 100 to 2000 nozzles 41 in the row and 2 units in the column, for a total of 200 to 4000 nozzles 41, and the same number of supply passages 51 and communication passages 52 as there are nozzles 41. In this configuration, the supply passages 51, connecting passages 52, pressure chambers 131, and nozzles 41, arranged in two rows of 100 to 2000 each along the row direction according to this embodiment, form channel groups 10a and 10b. The common flow path 123 is a common flow path for 200 to 4000 channels and is connected to the 200 to 4000 supply passages 51, which are arranged in two rows of 100 to 2000 each, and supplies liquid to the 200 to 4000 nozzles 41. In the plan view of the actuator substrate 3 shown in Figure 8, parts of the channel groups 10a and 10b, which are arranged in two rows in the row direction, are shown within the frames, respectively.

[0052] The bottom plate 121c is located on the support substrate 2. The upper surface of the support substrate 2 forms the bottom of the common channel 123. However, the bottom plate 121c may have a bottom and the common channel 123 may be located inside it. In this case, a hole communicating with the supply channel 51 may be provided in the bottom of the bottom plate 121c. The supply channel 51 penetrates the support substrate 2 in the Z-axis direction.

[0053] The bonding layer 3a is bonded to the support substrate 2. The communication passage 52 penetrates the bonding layer 3a and is connected to the supply passage 51. The actuator substrate 3 includes a bonding layer 3a that is bonded to the support substrate 2, and the bonding layer 3a is a substrate having a communication passage 52 that is connected to the supply passage 51 and supplies liquid to the nozzle 41.

[0054] The pressure chamber 131 is located below the actuator 30 and is connected to the communication passage 52, which connects the communication passage 52 to the nozzle 41. The pressure chamber 131 is a space enclosed by the diaphragm 38, the upper surface of the nozzle substrate 4, and the solid 39, and extends from a position below the communication passage 52 to a position above the nozzle 41.

[0055] Figure 6 is a perspective view showing a schematic configuration of part of the channel group 10a. In Figure 6, the channel group 10b is omitted. As shown in Figure 6, the actuator substrate 3 can be electrically connected to the outside through terminal 143 by electrical junctions 141 and 142 located at one end of the channel group 10a. One end of the channel group 10a is located on the opposite side of the channel group 10b.

[0056] <Configuration of Actuator Substrate> The detailed configuration of the actuator substrate 3 will be described with reference to Figures 7 and 8. Figure 7 is a cross-sectional view showing the detailed configuration of the actuator substrate 3. Figure 8 is a schematic plan view showing the actuator substrate 3. Note that Figure 7 shows the configuration of channel group 10a, and the configuration of channel group 10b is omitted. Since the configuration of channel group 10a and the configuration of channel group 10b are the same, the explanation of the configuration of channel group 10b will be omitted.

[0057] The thickness (length in the Z-axis direction) of the support substrate 2 is, for example, 200 to 400 μm. The thickness (length in the Z-axis direction) of the actuator substrate 3 is, for example, 30 to 75 μm. The thickness (length in the Z-axis direction) of the nozzle substrate 4 is, for example, 75 to 150 μm. In Figure 7, for convenience, the thickness of the actuator substrate 3 is shown to be thicker than the thickness of the nozzle substrate 4, but in reality, the thickness of the nozzle substrate 4 is thicker than the thickness of the actuator substrate 3. The constituent materials of the support substrate 2, pressure chamber substrate 3b, and nozzle substrate 4 may be Si.

[0058] The bonding layer 3a has a bonding film 31, an actuator 30, and a diaphragm 38. The bonding film 31 is bonded to the support substrate 2 on the upper surface of the bonding layer 3a. The communication passage 52 penetrates the bonding film 31, and the side surface of the communication passage 52 is the SiO of the bonding film 31. ２The bonding film 31 is formed of Si. The connecting passage 52 is located below the supply passage 51 and communicates with the supply passage 51. The bonding of the support substrate 2 and the bonding film 31 may be done by room temperature direct bonding using intermolecular forces, adhesive bonding, or gold-gold bonding. The bonding of the pressure chamber substrate 3b and the nozzle substrate 4 may also be done by room temperature direct bonding. Since the pressure chamber substrate 3b and the nozzle substrate 4 are formed from the same constituent material, they are easy to bond, and other bonding methods may also be used.

[0059] The pressure chamber 131 is located below the communication passage 52 and communicates with the communication passage 52. The pressure chamber 131 has an inlet passage 53. The inlet passage 53 is the connection portion of the pressure chamber 131 that communicates with the communication passage 52 at the connection portion between the communication passage 52 and the pressure chamber 131. The connection portion between the communication passage 52 and the pressure chamber 131 is the portion where the bonding layer 3a and the pressure chamber substrate 3b are connected at the boundary between the bonding layer 3a and the pressure chamber substrate 3b. As a result, the bonding layer 3a and the pressure chamber substrate 3b communicate with each other.

[0060] The pressure chamber 131 is connected to the communication passage 52 by an inlet passage 53 and extends below the actuator 30 on the positive X-axis side. Furthermore, there is a one-to-one correspondence between the pressure chamber 131 of each channel and the actuator 30, forming a single hollow region 3A within the actuator substrate 3. Liquid is stored within the pressure chamber 131. Each channel's pressure chamber 131 corresponds one-to-one with the supply passage 51, the communication passage 52, and the nozzle 41, and liquid is supplied from the common passage 123 of the manifold member 12. The common passage 123 supplies liquid to 200 to 4000 channels.

[0061] The thickness of the bonding layer 3a may be several μm to 20 μm. The thickness of the pressure chamber substrate 3b may be 30 to 75 μm. Examples of materials used to construct the pressure chamber substrate 3b include Si.

[0062] For example, the depth (length in the Z-axis direction) of the supply passage 51 is equal to the thickness of the support substrate 2 and may be 200 to 400 μm. The depth (length in the Z-axis direction) of the communication passage 52 is equal to the length from the upper surface of the bonding film 31 to the lower surface of the diaphragm 38, i.e., the thickness of the bonding layer 3a and may be several μm to 20 μm. The depth (length in the Z-axis direction) of the pressure chamber 131 is equal to the thickness of the pressure chamber substrate 3b and may be 30 to 75 μm.

[0063] The solid core 39 is located around each hollow region 3A between the diaphragm 38 and the nozzle substrate 4, and has the function of separating each hollow region 3A from other hollow regions 3A. Examples of materials that make up the solid core 39 include silicon.

[0064] The diaphragm 38 is located above the pressure chamber 131 and above the solid 39. The diaphragm 38 has openings in parts corresponding to each pressure chamber 131. Liquid is supplied to the pressure chamber 131 from the common channel 123 through these openings. The openings in the diaphragm 38 form part of the communication passage 52.

[0065] The thickness of the diaphragm 38 may be, for example, 1 μm or more and 10 μm or less. The diaphragm 38 in this embodiment is a single layer, but is not limited to this. For example, the diaphragm 38 may have a multilayer structure. Also, the diaphragm 38 may have a multilayer structure locally, for example, only on the solid 39. That is, the thickness of the diaphragm 38 on the solid 39 may be thicker than the thickness of the diaphragm 38 on the pressure chamber 131. Examples of constituent materials for the diaphragm 38 are Si, SiO ２ These are some examples.

[0066] The actuator 30 is provided on a diaphragm 38 corresponding to the pressure chamber 131. The actuator 30 has a common electrode 35, a piezoelectric element 36, and individual electrodes 37. The actuator 30 is provided in a 1:1 relationship with the pressure chamber 131. The actuator 30 has the common electrode 35 located on the diaphragm 38 corresponding to the pressure chamber 131, the piezoelectric element 36 located on the common electrode 35, and the individual electrodes 37 located on the piezoelectric element 36, but is not limited to this. For example, the individual electrodes 37, piezoelectric element 36, and common electrode 35 may be provided on the diaphragm 38 in that order.

[0067] The common electrode 35 is provided across the actuators 30 of multiple channels in each channel group 10a, 10b in a plan view of the actuator substrate 3 shown in Figure 8, but is not limited to this. For example, the common electrode 35 may be provided individually corresponding to each actuator 30 of each channel. The thickness of the common electrode 35 may be, for example, 0.1 to 1 μm. The constituent material of the common electrode 35 may be, for example, a metallic material such as Pt.

[0068] The piezoelectric elements 36 are individually provided corresponding to each pressure chamber 131, but are not limited to this arrangement. For example, the piezoelectric elements 36 may be provided across multiple channel pressure chambers 131 in a plan view of the actuator substrate 3. In the piezoelectric element 36, the portion sandwiched between the individual electrodes 37 and the common electrode 35 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 36 by the individual electrodes 37 and the common electrode 35, the piezoelectric element 36 contracts in a direction along the diaphragm 38. This contraction causes the piezoelectric element 36 to displace so that it becomes convex toward the pressure chamber 131. Along with the displacement of the piezoelectric element 36, the diaphragm 38 located on the pressure chamber 131 also displaces. As a result, pressure is applied to the liquid in the pressure chamber 131. This causes the liquid to be discharged from the pressure chamber 131 through the nozzle 41.

[0069] The thickness of the piezoelectric element 36 may be 1 μm or more and 10 μm or less. The constituent material of the piezoelectric element 36 is, for example, Pb(Zr,Ti)O ３ System, NaNbo ３ system, BaTiO ３ System, (BiNa)NboO ３ System, BiNaNB ５ O １５ Examples include ferroelectric ceramic constituent materials such as those found in certain systems.

[0070] Each individual electrode 37 is provided separately, corresponding to each pressure chamber 131. The thickness of each individual electrode 37 may be 0.05 μm or more and 1 μm or less. The constituent material of the individual electrode 37 may be a metallic material such as Pt.

[0071] The electrical joints 141 and 142 shown in FIG. 6 and FIG. 8 are located on the end portion of the actuator substrate 3 in the X-axis direction. The tips of the electrical joints 141 and 142 are formed of a plurality of terminals 143. The plurality of terminals 143 are electrically connected to the actuator substrate 3.

[0072] As shown in FIG. 7, the bonding layer 3a includes a vibration plate 38 located on the pressure chamber substrate 3b, an actuator 30 located on the vibration plate 38, an insulating film 33, and a bonding film 31. The insulating film 33 is located over at least a part of the actuator 30. The bonding film 31 is located over at least a part of the insulating film 33. The insulating film 33 is provided on the actuator 30 to prevent short circuits between the actuator 30 of each channel and the actuator 30 of another channel, or wirings such as the lead wiring 144.

[0073] The bonding film 31 is located under the support substrate 2, and bonds the support substrate 2 and the bonding layer 3a together. The thickness of the bonding film 31 may be, for example, 4 μm. Further, the constituent material of the bonding film 31 is, for example, SiO ２ and the like.

[0074] As shown in FIG. 7, below the bonding film 31, a protective film 32, an insulating film 33, and a common electrode 35 are laminated in this order from the top. The thickness of the protective film 32 may be, for example, 0.1 to 1 μm. Further, examples of the constituent material of the protective film 32 include materials such as SiN.

[0075] The thickness of the insulating film 33 may be, for example, 0.1 to 1 μm. Further, the constituent material of the insulating film 33 is, for example, SiO ２ and the like.

[0076] Note that the actuator 30 may have an unillustrated adhesion layer between the common electrode 35 and the piezoelectric body 36, and between the individual electrode 37 and the piezoelectric body 36. The thickness of the adhesion layer may be, for example, 0.05 μm. Further, examples of the constituent material of the adhesion layer include materials such as SiN.

[0077] The protective film 32 and the insulating film 33 are located on at least a portion of the actuator 30. The upper surface of the actuator 30 is exposed to the space 132, except for the outer periphery of the actuator 30.

[0078] The lead wires 144 are electrically connected to the individual electrodes 37 and are wires that extend from each individual electrode 37. In the example shown in Figure 7, the lead wires 144 are positioned between the protective film 32 and the insulating film 33 and extend from the portion corresponding to the pressure chamber 131 to the portion corresponding to the solid 39. The thickness of the lead wires 144 may be, for example, 0.1 μm or more and 1 μm or less. The constituent material of the lead wires 144 may be, for example, Au.

[0079] The protective film 32 protects the actuator 30 beneath the bonding film 31. The insulating film 33 is provided on the diaphragm 38 to cover the lead wiring 144 in order to reduce the possibility of corrosion of the lead wiring 144. The insulating film 33 is in close contact with the diaphragm 38, which generally corresponds to the solid 39 excluding the pressure chamber 131.

[0080] The bonding film 31, protective film 32, insulating film 33, common electrode 35, individual electrode 37, and lead wiring 144 according to this embodiment may be formed on each layer using the CVD method. By using the CVD method, the step coverage is improved, so the coverage of each layer and lead wiring 144 is improved, and the possibility of corrosion of each layer and lead wiring 144 can be further reduced. However, each layer and lead wiring 144 according to this embodiment may be formed using the sputtering method, not limited to the CVD method. By using the sputtering method, particles that will become the constituent material of each layer and lead wiring 144 will adhere. Therefore, the adhesion between each layer and the diaphragm 38 and lead wiring 144 can be improved. In addition, the lead wiring 144 may be formed at a desired position by the lift-off method using a resist. The cross-sectional shape of the lead wiring 144 may be a shape without corners at the time of film formation of the lead wiring 144, but is not limited to this. The cross-sectional shape of the lead wiring 144 may be made without corners by etching the corners after the lead wiring 144 is formed.

[0081] The wiring of the actuator substrate 3 according to this embodiment will be further described with reference to Figure 8. In a plan view, the actuator substrate 3 shown in Figure 8 shows a portion of the channel groups 10a and 10b arranged in two rows. 100 to 2000 lead wires 144 are located on each of the channel groups 10a and 10b.

[0082] The number of lead wires 144 on each channel group 10a, 10b may be set as appropriate. Each lead wire 144, when viewed from above, is connected to an individual electrode 37 corresponding to the pressure chamber 131 and is led out in the positive X-axis direction. Of the multiple lead wires 144, the lead wire 144b led out from channel group 10b is connected to an electrical junction 142 within the individual terminal region 201 formed in the positive X-axis direction of channel group 10a. The electrical junction 142 runs along the positive X-axis direction within the individual terminal region 201 and is electrically connected to the terminal 143 of the individual terminal region 201. Of the multiple lead wires 144, the lead wire 144a led out from channel group 10a in the positive X-axis direction is connected to an electrical junction 141 within the individual terminal region 201. The electrical junction 141 runs along the positive X-axis direction within the individual terminal region 201 and is electrically connected to the terminal 143 of the individual terminal region 201.

[0083] Therefore, each actuator 30 of channel groups 10a and 10b receives a drive signal from the drive IC 111 on the COF substrate 11 via terminals 143 through electrical junctions 141 and 142. Each individual electrode 37 of each actuator 30 is supplied with an individual drive potential via lead wiring 144 based on the drive signal (see Figure 5).

[0084] With this configuration, each actuator 30 of channel groups 10a and 10b receives a drive signal corresponding to a desired control signal from the control unit 200 (Figure 8(1)), and displaces the piezoelectric element 36 so that it protrudes toward the pressure chamber 131 according to the drive signal. As the piezoelectric element 36 is displaced, the diaphragm 38 located on the pressure chamber 131 is displaced, and pressure is applied to the liquid in the pressure chamber 131. As a result, liquid is discharged from each pressure chamber 131 through each nozzle 41. This causes the drive IC 111 to drive the liquid discharge head 1.

[0085] The common electrode 35 is electrically connected to the ground connection 145 of the ground region 202 via the common wiring 146 (Figure 8(2)). As a result, the common electrode 35 is supplied with ground potential. Ground potential means 0V. Note that the common wiring 146 is not shown in Figures 5 to 7.

[0086] <Configuration of the lead-out wiring and its vicinity> Next, the configuration of the lead-out wiring 144b and its vicinity will be explained with reference to Figures 9 to 11. Figure 9 is a cross-sectional view along the line VIII-VIII shown in Figure 8.

[0087] As shown in Figure 9, the actuator substrate 3 comprises a plurality of pressure chambers 131, a pressure chamber girder 134, a diaphragm 38, lead wiring 144b, a protective film 32, an insulating film 33, and a plurality of actuators 30.

[0088] The multiple pressure chambers 131 include a first pressure chamber 131a and a second pressure chamber 131b that are adjacent in the Y-axis direction, with the pressure chamber girder 134 in between. The Y-axis direction is an example of a first direction. The bottom surfaces of the multiple pressure chambers 131 are closed by a nozzle substrate 4 having a nozzle 41.

[0089] The pressure chamber girder 134 is located between adjacent pressure chambers 131 in the Y-axis direction, for example, between the first pressure chamber 131a and the second pressure chamber 131b. The pressure chamber girder 134 constitutes a part of the solid 39 and separates the first pressure chamber 131a and the second pressure chamber 131b. The width of the pressure chamber girder 134 in the Y-axis direction may be about 10 to 20 μm. The pressure chamber girder 134 is an example of the first part.

[0090] The diaphragm 38 is located above the first pressure chamber 131a, above the pressure chamber girder 134, and above the second pressure chamber 131b.

[0091] The lead wire 144b is located on the diaphragm 38 corresponding to the pressure chamber girder 134. The lead wire 144b is one of several lead wires 144 (see Figure 8), specifically the lead wire 144 drawn out from the channel group 10b (see Figure 8). Between the lead wire 144b and the diaphragm 38, an insulating film 33 and a common electrode 35 are interposed from top to bottom. That is, the lead wire 144b is located on the diaphragm 38 corresponding to the pressure chamber girder 134, with the insulating film 33 and the common electrode 35 sandwiched between the lead wire 144b and the diaphragm 38. The lead wire 144b extends in the X-axis direction, which intersects with the Y-axis direction. The X-axis direction is an example of a second direction.

[0092] The protective film 32 and the insulating film 33 are located on at least a portion of each actuator 30. The upper surface of each actuator 30 is exposed from the protective film 32 and the insulating film 33, except for the outer circumference of each actuator 30. The protective film 32 is provided on the diaphragm 38 so as to cover the lead wiring 144b and each actuator 30 from above. The insulating film 33 is provided on the diaphragm 38 so as to cover the lead wiring 144b from below.

[0093] Multiple actuators 30 are located on a diaphragm 38 corresponding to multiple pressure chambers 131. Each actuator 30 is provided in a one-to-one relationship with each pressure chamber 131. The multiple actuators 30 include a first actuator 30a corresponding to a first pressure chamber 131a and a second actuator 30b corresponding to a second pressure chamber 131b.

[0094] The first actuator 30a has a common electrode 35, a first piezoelectric element 36a, and individual electrodes 37. In the first actuator 30a, the common electrode 35, the first piezoelectric element 36a, and the individual electrodes 37 are positioned in this order on a diaphragm 38 corresponding to the first pressure chamber 131a. The second actuator 30b has a common electrode 35, a second piezoelectric element 36b, and individual electrodes 37. In the second actuator 30b, the common electrode 35, the second piezoelectric element 36b, and the individual electrodes 37 are positioned in this order on a diaphragm 38 corresponding to the second pressure chamber 131b.

[0095] The first piezoelectric element 36a and the second piezoelectric element 36b are displaced toward the first pressure chamber 131a and the second pressure chamber 131b by the application of voltage from the individual electrodes 37 and the common electrode 35. As the first piezoelectric element 36a and the second piezoelectric element 36b are displaced, the diaphragms 38 located above the first pressure chamber 131a and the second pressure chamber 131b are displaced, and pressure is applied to the liquid in the first pressure chamber 131a and the second pressure chamber 131b. As a result, the liquid is discharged from each of the first pressure chamber 131a and the second pressure chamber 131b through the respective nozzles 41.

[0096] Figure 10 shows an example of the contour 150 of the lead wiring 144b shown in Figure 9. As shown in Figure 10, the contour 150 of the lead wiring 144b, when viewed in cross-section in a plane perpendicular to the X-axis direction, has a first contour line 151 and a second contour line 152.

[0097] The first contour line 151 extends linearly in a direction (for example, in the Y-axis direction) along the upper surface of the diaphragm 38 (see Figure 9). When the portion including the diaphragm 38 located between the lead wiring 144b and the pressure chamber girder 134 (an example of the first portion) is designated as the second portion, the first contour line 151 may be the portion in contact with the lead wiring 144b and the second portion. That is, the first contour line 151 may be in contact with the second portion. The second portion in this embodiment includes the diaphragm 38, a common electrode 35 located on the diaphragm 38, and an insulating film 33 located on the common electrode 35. The first contour line 151 is the portion of the contour 150 that is in contact with the insulating film 33. This allows the lead wiring 144 to be provided without short-circuiting the lead wiring 144b and the common electrode 35, while the common electrode 35 is positioned below the first contour line 151.

[0098] In this example, the second part is shown as a multilayer structure in which the diaphragm 38, common electrode 35, and insulating film 33 are stacked in that order. However, the structure of the second part is not limited to a multilayer structure. For example, in another embodiment, the second part may consist only of the diaphragm 38. In this case, the first contour line 151 may be the portion of the contour 150 that is in contact with the diaphragm 38.

[0099] The second contour line 152 is connected to both ends of the first contour line 151 and extends in the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9). The second contour line 152 has no corners. A corner is a part where two straight lines intersect. The fact that the second contour line 152 has no corners means that the second contour line 152 does not have any parts where two straight lines intersect. The second contour line 152 does not need to have corners; for example, it may have parts where a straight line and a curve intersect, or parts where curves of different curvatures intersect. The second contour line 152 is the part of the contour 150 other than the first contour line 151. In other words, the second contour line 152 is the part of the contour 150 that is in contact with the film covering the lead wiring 144b (in this embodiment, the protective film 32).

[0100] The second contour line 152 of the contour 150 according to this embodiment is an arc shape that protrudes in the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9). That is, the second contour line 152 protrudes in a curved shape away from the diaphragm 38 (see Figure 9) in the section from one end to the other of the first contour line 151.

[0101] Here, the lead wiring 144b, located on the diaphragm 38 corresponding to the pressure chamber girder 134, is susceptible to stress from the diaphragm 38 when the diaphragm 38 located on the first pressure chamber 131a and the second pressure chamber 131b are displaced. As a result, shear stress is generated between the lead wiring 144 and the film covering the lead wiring 144b from above, i.e., the protective film 32, which may cause the protective film 32 to peel off from the lead wiring 144b.

[0102] In contrast, in the liquid discharge head 1 according to this embodiment, the contour 150 of the lead wiring 144b does not have corners on the second contour line 152 that protrudes in the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9). As a result, the covering of the lead wiring 144b can be improved compared to the case where the contour 150 has corners on the second contour line 152, for example, the case where the contour 150 has a portion where two straight lines intersect. As a result, even when shear stress is generated between the lead wiring 144 and the protective film 32 due to stress from the diaphragm 38, the peeling of the protective film 32 covering the lead wiring 144b can be reduced.

[0103] Furthermore, since the second contour line 152 of the contour 150 is arc-shaped and protrudes in the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9), the coverage of the lead wiring 144b can be further improved.

[0104] Furthermore, the curvature of the central portion 152a of the second contour line 152 may be greater than the curvature of the end portion 152b of the second contour line 152. Here, the end portion 152b refers to the regions at both ends of the area obtained by dividing the lead wiring 144b into three equal parts in the Y-axis direction. The central portion 152a refers to the region in the center of the area obtained by dividing the lead wiring 144b into three equal parts in the Y-axis direction. The curvature of the central portion 152a of the second contour line 152 is 4 to 6 × 10 ４ It may be expressed as [rad / m]. The curvature of the end 152b of the second contour line 152 is 2 to 4 × 10 ４ The value may be [rad / m]. The curvature of the second contour line 152 may increase from the end 152b of the second contour line 152 toward the central part 152a. This makes it less likely for shear stress to occur between the lead wiring 144 and the protective film 32 near the end 152b of the second contour line 152, compared to the case where the curvature of the second contour line 152 is constant, and further reduces peeling of the protective film 32 covering the lead wiring 144b.

[0105] Furthermore, in order to prove the relationship between the magnitudes of curvature, it is not necessary to precisely determine the curvature. For example, when comparing the following first distance D1 and second distance D2, if the second distance D2 is longer, the curvature of the central part 152a of the second contour line 152 may be considered greater than the curvature of the end part 152b of the second contour line 152. First distance D1: The distance from line A, which connects the outermost part of the second contour line 152 (the part that touches the first contour line 151) to the connection point between the central part 152a and the end part 152b of the second contour line 152, to the end part 152b of the second contour line 152, to the longest distance. Second distance D2: The distance from line B, which connects the connection point between the central part 152a and one end part 152b of the second contour line 152 to the connection point between the central part 152a and the other end part 152b of the second contour line 152, to the central part 152a of the second contour line 152, to the longest distance.

[0106] Furthermore, the thickness t of the lead wire 144b may be 1 / 10 or less of the width w of the lead wire 144b. The thickness t of the lead wire 144b may be, for example, about 0.1 to 1.0 μm, and the width w of the lead wire 144b may be, for example, about 5 to 20 μm. With this configuration, compared to the case where the thickness t is greater than 1 / 10 of the width w, the step of the lead wire 144b along the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9) is reduced, and thus the covering performance of the lead wire 144b can be further improved.

[0107] Furthermore, in this embodiment, the lead wiring 144b (see Figure 9) does not overlap with the first pressure chamber 131a and the second pressure chamber 131b when viewed from above. This reduces the stress generated between the lead wiring 144b and the protective film 32, and further reduces peeling of the protective film 32 covering the lead wiring 144b. In another embodiment, a portion of the lead wiring 144b may overlap with the first pressure chamber 131a or the second pressure chamber 131b when viewed from above. This reduces vibration in the portion of the diaphragm 38 located above the first pressure chamber 131a or the second pressure chamber 131b that overlaps with the lead wiring 144b. As a result, vibration can be reduced at the corner C (see Figure 9) formed by the pressure chamber girder 134 (an example of the first portion) and the diaphragm 38, which are prone to cracking, and the occurrence of cracks can be reduced.

[0108] The thickness of the lead wire 144b is, for example, the height of the highest point of the second contour line 152 from the first contour line 151, and the width of the lead wire 144b is, for example, the length of the first contour line 151.

[0109] As shown in Figures 9 and 10, the protective film 32 continuously covers at least a portion of the first piezoelectric element 36a, the lead wiring 144b, and at least a portion of the second piezoelectric element 36b along the Y-axis direction, and the lead wiring 144b is in contact with the protective film 32 on the surface including the second contour line 152. This increases the adhesion between the lead wiring 144b and the protective film 32, and even when the protective film 32 is subjected to stress due to the displacement of the first piezoelectric element 36a and the second piezoelectric element 36b, peeling of the protective film 32 covering the lead wiring 144b can be reduced.

[0110] The configuration of the lead-out wiring 144b also applies to the lead-out wiring 144a and the common wiring 146. A detailed explanation follows below.

[0111] First, let's describe the case where the configuration of the lead wiring 144b is applied to the lead wiring 144a. When viewed in cross-section with a plane perpendicular to the X-axis direction, the lead wiring 144a has a first contour line 151 (see Figure 10) and a second contour line 152 (see Figure 10). The first contour line 151 extends linearly in the direction along the upper surface of the diaphragm 38 (see Figure 9) (for example, in the Y-axis direction). The first contour line 151 is the portion of the contour 150 that is in contact with the insulating film 33 of the second portion. The second contour line 152 is connected to both ends of the first contour line 151 and extends in the thickness direction of the diaphragm 38 (for example, in the Z-axis direction). The second contour line 152 does not have corners. A corner is a portion where two straight lines intersect. The fact that the second contour line 152 does not have corners means that the second contour line 152 does not have a portion where two straight lines intersect. The second contour line 152 is the portion of the contour line 150 other than the first contour line 151.

[0112] Thus, in this embodiment, the contour 150 of the lead wiring 144a does not have corners in the second contour line 152 that protrudes in the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9). As a result, even if shear stress occurs between the lead wiring 144a and the protective film 32 due to stress from the diaphragm 38, the peeling of the protective film 32 covering the lead wiring 144a can be reduced.

[0113] Furthermore, as shown in Figure 7, the lead wires 144a and 144b are located in areas that overlap with the piezoelectric body 36 and the individual electrodes 37 in order to connect to the individual electrodes 37. The portions of the lead wires 144a and 144b that overlap with the piezoelectric body 36 and the individual electrodes 37 have stepped sections. For this reason, the protective film 32 covering the lead wires 144a and 144b is prone to peeling in the portions that overlap with the piezoelectric body 36 and the individual electrodes 37. In this embodiment, since the second contour line 152 of the lead wires 144a and 144b does not have corners, peeling of the protective film 32 is less likely to occur even in the portions that overlap with the piezoelectric body 36 and the individual electrodes 37.

[0114] Next, we will describe the case where the configuration of the lead wiring 144b is applied to the common wiring 146. When the common wiring 146 is viewed in cross-section from a plane perpendicular to the X-axis or Y-axis, it has a first contour line 151 (see Figure 10) and a second contour line 152 (see Figure 10). The first contour line 151 extends linearly in a direction along the upper surface of the diaphragm 38 (see Figure 9). In this embodiment, since the common wiring 146 is located on the diaphragm 38, the first contour line 151 of the common wiring 146 is the part of the contour 150 that is in contact with the diaphragm 38. The second contour line 152 is connected to both ends of the first contour line 151 and extends in the thickness direction of the diaphragm 38 (for example, in the Z-axis direction). The second contour line 152 does not have corners. A corner is a part where two straight lines intersect. The statement that the second contour line 152 does not have corners means that the second contour line 152 does not have any parts where straight lines intersect. The second contour line 152 is the part of the contour 150 other than the first contour line 151.

[0115] Thus, in this embodiment, the contour 150 of the common wiring 146 does not have corners in the second contour line 152 that protrudes in the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9). As a result, even if shear stress occurs between the common wiring 146 and the protective film 32 due to stress from the diaphragm 38, the peeling of the protective film 32 covering the common wiring 146 can be reduced. Furthermore, since the common wiring 146 is connected to multiple actuators 30, it is even more important to reduce the peeling of the protective film 32.

[0116] Figure 11 is an enlarged view of region XI shown in Figure 8. As shown in Figure 11, when viewed from the thickness direction (for example, the Z-axis direction) of the diaphragm 38 (see Figure 9), the lead wiring 144b may have a first portion 161 and a second portion 162. The first portion 161 is positioned to overlap with the pressure chamber girder 134. The second portion 162 is connected to the first portion 161 and extends outward from the position where it overlaps with the pressure chamber girder 134 in the X-axis direction. The width w1 of the first portion 161 may be smaller than the width w2 of the second portion 162. The width w1 of the first portion 161 can be, for example, about 5 to 10 μm, and the width w2 of the second portion 162 can be, for example, about 10 to 20 μm. In other words, the width w2 of the second portion may be greater than 1 times the width w1 of the first portion and less than 2 times the width w1 of the first portion. The width w1 of the first section 161 may be smaller than the width of the pressure chamber girder 134. Furthermore, the width w2 of the second section 162 may be larger than the width of the pressure chamber girder 134.

[0117] Thus, the width w1 of the first part 161 may be smaller than the width w2 of the second part 162. This allows the lead wiring 144b to be positioned so as not to overlap with the pressure chamber 131 when viewed from above. As a result, the possibility of the lead wiring 144b obstructing the displacement of the pressure chamber 131 can be reduced.

[0118] As described above, the liquid discharge head according to the embodiment (for example, liquid discharge head 1) comprises a first pressure chamber (for example, a first pressure chamber 131a) and a second pressure chamber (for example, a second pressure chamber 131b), a first part (for example, a pressure chamber beam 134), a diaphragm (for example, a diaphragm 38), wiring (for example, lead wiring 144b), and a second part. The first and second pressure chambers are adjacent in a first direction (for example, the Y-axis direction). The first part is located between the first and second pressure chambers. The diaphragm is located above the first pressure chamber, above the first part, and above the second pressure chamber. The wiring overlaps the first part and extends in a second direction (for example, the X-axis direction) that intersects the first direction. The second part includes a diaphragm located between the first part and the wiring. When viewed in cross-section from a plane perpendicular to the second direction, the wiring contour (for example, contour 150) has a first contour line (for example, first contour line 151) that is tangent to the second portion, and a second contour line (for example, second contour line 152) that is connected to both ends of the first contour line and does not have corners.

[0119] Therefore, according to the liquid discharge head of the embodiment, peeling of the film covering the wiring can be reduced.

[0120] <Note> The following additional notes are disclosed regarding the above embodiments. (1) A liquid discharge head comprising: a first pressure chamber and a second pressure chamber adjacent to each other in a first direction; a first portion located between the first pressure chamber and the second pressure chamber; a diaphragm located above the first pressure chamber, above the first portion and above the second pressure chamber; wiring overlapping the first portion and extending in a second direction intersecting the first direction; and a second portion including the diaphragm located between the first portion and the wiring, wherein, when viewed in cross-section in a plane perpendicular to the second direction, the contour of the wiring has a first contour line tangent to the second portion and a second contour line connected to both ends of the first contour line and having no corners. (2) The liquid discharge head according to (1), wherein the second contour line is arc-shaped. (3) The liquid discharge head according to (2), wherein the curvature of the central part of the second contour line is greater than the curvature of the ends of the second contour line. (4) The liquid discharge head according to any one of (1) to (3), wherein the thickness of the wiring is 1 / 10 or less of the width of the wiring. (5) The liquid discharge head according to any one of (1) to (4), wherein, when viewed in plan from the thickness direction of the diaphragm, the wiring has a first portion that is positioned to overlap with the first portion, and a second portion that is connected to the first portion and extends outward from the position where it overlaps with the first portion, and the width of the first portion is smaller than the width of the second portion. (6) The liquid discharge head according to (5), wherein the width of the second portion is greater than 1 times the width of the first portion and less than 2 times the width of the first portion. (7) The liquid discharge head according to any one of (1) to (6), wherein the wiring does not overlap with the first pressure chamber and the second pressure chamber. (8) The liquid discharge head according to any one of (1) to (6), wherein the wiring overlaps with the first pressure chamber or the second pressure chamber.(9) A liquid discharge head according to any one of (1) to (8), further comprising a first piezoelectric element overlapping the first pressure chamber, a second piezoelectric element overlapping the second pressure chamber, and a protective film covering the wiring, wherein the protective film continuously covers at least a portion of the first piezoelectric element, the wiring, and at least a portion of the second piezoelectric element along the first direction, and the wiring is in contact with the protective film on a surface including the second contour line. (10) A liquid discharge head according to any one of (1) to (8), further comprising a first actuator overlapping the first pressure chamber and a second actuator overlapping the second pressure chamber, wherein the second portion has a diaphragm located on the first portion, a common electrode located on the diaphragm and common to the first actuator and the second actuator, and an insulating film located on the common electrode, wherein the first contour line is in contact with the insulating film. (11) A liquid discharge head according to any one of (1) to (8), wherein the first contour line is in contact with the diaphragm. (12) A recording device comprising a liquid dispensing head described in any one of (1) to (11), and a control unit for controlling the liquid dispensing head.

[0121] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0122] 1 Liquid discharge head 2 Support substrate 3 Actuator substrate 3a Bonding layer 3A Hollow region 3b Pressure chamber substrate 4 Nozzle substrate 10 MEMS chip 10a, 10b Channel group 12 Manifold member 30 Actuator 30a First actuator 30b Second actuator 31 Bonding film 32 Protective film 33 Insulating film 35 Common electrode 36 Piezoelectric element 36a First piezoelectric element 36b Second piezoelectric element 37 Individual electrode 38 Diaphragm 39 Solid 41 Nozzle 100 Printer 131 Pressure chamber 131a First pressure chamber 131b Second pressure chamber 134 Pressure chamber beam 144, 144a, 144b Lead-out wiring 150 Contour 151 First contour line 152 Second contour line 161 First part 162 Second part 200 control unit

Claims

1. A liquid discharge head comprising: a first pressure chamber and a second pressure chamber adjacent to each other in a first direction; a first portion located between the first pressure chamber and the second pressure chamber; a diaphragm located above the first pressure chamber, above the first portion and above the second pressure chamber; wiring overlapping the first portion and extending in a second direction intersecting the first direction; and a second portion including the diaphragm located between the first portion and the wiring, wherein, when viewed in cross-section in a plane perpendicular to the second direction, the contour of the wiring has a first contour line tangent to the second portion and a second contour line connected to both ends of the first contour line and having no corners.

2. The liquid dispensing head according to claim 1, wherein the second contour line is arc-shaped.

3. The liquid discharge head according to claim 2, wherein the curvature of the central part of the second contour line is greater than the curvature of the ends of the second contour line.

4. The liquid dispensing head according to any one of claims 1 to 3, wherein the thickness of the wiring is 1 / 10 or less of the width of the wiring.

5. A liquid dispensing head according to any one of claims 1 to 4, wherein, when viewed in plan from the thickness direction of the diaphragm, the wiring has a first portion located so as to overlap with the first portion, and a second portion connected to the first portion and extending outward from the position overlapping with the first portion, and the width of the first portion is smaller than the width of the second portion.

6. The liquid dispensing head according to claim 5, wherein the width of the second portion is greater than one times the width of the first portion and less than twice the width of the first portion.

7. The liquid discharge head according to any one of claims 1 to 6, wherein the wiring does not overlap with the first pressure chamber and the second pressure chamber.

8. The liquid discharge head according to any one of claims 1 to 6, wherein the wiring overlaps with the first pressure chamber or the second pressure chamber.

9. A liquid dispensing head according to any one of claims 1 to 8, further comprising: a first piezoelectric element overlapping the first pressure chamber; a second piezoelectric element overlapping the second pressure chamber; and a protective film covering the wiring, wherein the protective film continuously covers at least a portion of the first piezoelectric element, the wiring, and at least a portion of the second piezoelectric element along the first direction, and the wiring is in contact with the protective film on a surface including the second contour line.

10. A liquid discharge head according to any one of claims 1 to 8, further comprising a first actuator overlapping the first pressure chamber and a second actuator overlapping the second pressure chamber, wherein the second portion has a diaphragm located on the first portion, a common electrode located on the diaphragm and common to the first actuator and the second actuator, and an insulating film located on the common electrode, and the first contour line is in contact with the insulating film.

11. The liquid discharge head according to any one of claims 1 to 8, wherein the first contour line is in contact with the diaphragm.

12. A recording device comprising a liquid dispensing head according to any one of claims 1 to 11, and a control unit for controlling the liquid dispensing head.

Images