Head chip, liquid jet head, and liquid jet recording device

Abstract

To provide a head chip, a liquid jet head and a liquid jet recording device capable of improving the degree of freedom in design and miniaturizing the head chip.SOLUTION: A head chip according to an aspect of the present disclosure includes: an actuator plate that is deformable so that a pressure chamber in which liquid is stored expands or contracts; a common electrode and individual electrodes which are formed on the actuator plate to generate an electric field in the actuator plate; and a cover plate which is superposed on the actuator plate. The cover plate is provided with through-holes that penetrates the cover plate. In the through-holes, common through-wiring that connects between external wiring provided in the cover plate and the common electrode and individual through-wiring that connects between the external wiring and the individual electrode are formed in a state of being separated from each other.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a head chip, a liquid jet head, and a liquid jet recording apparatus. [Background technology]

[0002] The inkjet head ejects ink onto a recording medium through a head chip. The head chip includes an actuator plate in which ejection channels are formed, and a cover plate overlaid on the actuator plate. The cover plate is formed with a through hole that functions as a through hole (see, for example, Patent Document 1 below). That is, a through wiring is formed in the through hole, and the through wiring is connected to one of the common electrode and the individual electrodes (for example, the individual electrode) formed on the actuator plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-254234 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, since one system of through wiring is formed for one through hole, it is necessary to form two through holes in order to form two systems of through wiring. Therefore, in the conventional technology, there is still room for improvement in terms of improving design freedom and miniaturizing the head chip.

[0005] The present disclosure provides a head chip, a liquid jet head, and a liquid jet recording apparatus that enable improved design freedom and miniaturization of the head chip. [Means for solving the problem]

[0006] In order to solve the above problems, the present disclosure employs the following aspects. (1) A head chip according to one embodiment of the present disclosure comprises an actuator plate that is deformable so as to expand or contract a pressure chamber in which liquid is contained, a common electrode and an individual electrode formed on the actuator plate to generate an electric field in the actuator plate, and a cover plate overlaid on a first surface of the actuator plate facing a first side in a thickness direction, wherein a through hole is formed in the cover plate in the thickness direction, and within the through hole, a common through wiring that connects between the common electrode and an external wiring provided on the first side in the thickness direction of the cover plate, and an individual through wiring that connects between the external wiring and the individual electrode are formed in a state separated from each other.

[0007] According to this aspect, since two types of wiring (common through wiring and individual through wiring) are formed in a state separated from each other in one through hole, the number of through holes formed in the cover plate can be reduced compared to the case where one type of wiring is formed for each through hole. Therefore, it is possible to improve the design freedom and to miniaturize the head chip. By miniaturizing the head chip, for example, when the head chip is produced at the wafer level, the number of cover plates that can be obtained from one wafer can be increased. As a result, the cost of the head chip can be reduced.

[0008] (2) In the head chip according to the above aspect (1), the cover plate is formed with a first recess opening on a first surface facing a first side in the thickness direction and a second recess opening on a second surface facing a second side opposite to the first side in the thickness direction, the through hole is formed by portions of the first recess and the second recess that communicate with each other, the second recess has a first inner surface portion located at the same position as the inner surface of the first recess when viewed from the thickness direction or more inward than the inner surface of the first recess when viewed from the thickness direction, and a second inner surface portion located at a different position from the first inner surface portion when viewed from the thickness direction and outward from the inner surface of the first recess when viewed from the thickness direction, and it is preferable that the common through wiring and the individual through wiring penetrate the cover plate through the first inner surface portion and the inner surface of the first recess. According to this aspect, the first inner surface portion of the second recess is at the same position as the inner surface of the first recess or protrudes inwardly, so that when various wirings are formed through the first opening portion of the first recess that opens onto the first surface, it is easy to form the various wirings continuously over the first inner surface portion and the inner surface of the first recess. In addition, a portion (outer protrusion) that protrudes outward from the first recess when viewed in the thickness direction is formed in the second recess. Therefore, when the actuator plate and the cover plate are bonded together, the outer protrusion functions as an adhesive reservoir. This makes it possible to prevent the electrical continuity between the common through wire and the common electrode, and between the individual through wires and the individual electrodes, from being blocked by the adhesive.

[0009] (3) In the head chip relating to the above aspect (2), it is preferable that the first recesses are provided at intervals in a first direction intersecting the thickness direction, the second recess extends in the first direction so as to straddle at least two adjacent first recesses among the plurality of first recesses, the first inner surface portion is located on the inner surface of the second recess at the same position or inside the inner surface of the first recess in a second direction intersecting the first direction as viewed from the thickness direction, and the second inner surface portion is located on the inner surface of the second recess outward in the first direction relative to the inner surface of the first recess. According to this aspect, it is only necessary to provide one second recess for at least two adjacent first recesses among the multiple first recesses, which improves the manufacturing efficiency of the second recesses compared to the case where second recesses are separately formed corresponding to each first recess.

[0010] (4) In a head chip according to either aspect (2) or (3) above, it is preferable that the first recess is tapered such that an inner diameter thereof decreases toward a second side in the thickness direction, and that the dimension of the first recess in the thickness direction is greater than the dimension of the second recess in the thickness direction. According to this aspect, when the common through wiring and the individual through wiring are formed through the opening of the first recess by oblique deposition, for example, the common through wiring can be easily formed continuously on the inner surface of the through hole, thereby improving the yield and reducing the cost of the head chip.

[0011] (5) In a head chip according to either aspect (2) or (3) above, it is preferable that the first recess is formed in a tapered shape such that an inner diameter gradually decreases toward a second side in the thickness direction, and the dimension of the first recess in the thickness direction is smaller than the dimension of the second recess in the thickness direction. According to this aspect, when the first recess is formed by sandblasting or the like, the inner diameter is tapered so that it gradually decreases from the first opening to a predetermined range in the thickness direction, but once the predetermined range is exceeded, the inner diameter may expand once and then decrease again. In this case, a constricted portion is formed in the middle of the thickness direction in the first recess. The constricted portion tends to be formed on the second side in the thickness direction as the inner diameter of the first opening increases. Therefore, in this embodiment, the thickness dimension of the first recess is made smaller than the thickness dimension of the second recess, thereby making it possible to reduce the inner diameter of the first opening, thereby improving design freedom, narrowing the pitch of the pressure chambers, and miniaturizing the head chip.

[0012] (6) In a head chip according to any one of aspects (1) to (5) above, a common pad connected to the common through wiring at the opening edge of the through hole and an individual pad connected to the common through wiring at the opening edge of the through hole are formed on a first surface of the cover plate facing a first side in the thickness direction, and it is preferable that the common pad and the individual pad extend in a direction away from each other from the through hole on the first surface of the cover plate. According to this aspect, since the common pad and the individual pads extend from the opening edge of one through hole, the wiring length of the common pad and the individual pads can be reduced and the common pad and the individual pads can be placed closer to each other than when they extend from the upper opening edges of separate through holes. This makes it possible to reduce the electrostatic capacitance of the head chip. As a result, the responsiveness of the head chip can be improved and heat generation in the head chip can be suppressed.

[0013] (7) In a head chip according to any one of the above aspects (1) to (6), it is preferable that a separation processing portion is formed in the cover plate to separate the common through wiring and the individual through wiring within the through hole. According to this aspect, after the wiring materials that become the common through wiring and the individual through wiring are formed in the through hole at the same time, the common through wiring and the individual through wiring can be separated by post-processing, which improves manufacturing efficiency compared to the case where the formation areas of the common through wiring and the individual through wiring are controlled in advance by patterning or the like.

[0014] (8) In a head chip relating to any of the aspects of (7) above, it is preferable that the through holes are provided at intervals in a first direction intersecting the thickness direction, and the separation processing portion extends in a groove-like manner in the first direction so as to span between at least two adjacent through holes among the plurality of through holes. According to this aspect, by forming the separation processed portion across the plurality of through holes, the common through wiring and the individual through wiring of each of the plurality of through holes can be collectively separated, thereby making it possible to further improve manufacturing efficiency.

[0015] (9) A liquid jet head according to an aspect of the present disclosure preferably includes the head chip according to any one of the above aspects (1) to (8). According to this aspect, since the head chip according to the above aspect is included, it is possible to provide a small-sized, low-cost liquid jet head.

[0016] (10) A liquid jet recording apparatus according to an aspect of the present disclosure preferably includes the liquid jet head according to aspect (7) above. According to this aspect, since the head chip according to the above aspect is included, it is possible to provide a small-sized, low-cost liquid jet head. Effect of the Invention

[0017] According to one aspect of the present disclosure, it is possible to improve design freedom and reduce the size of the head chip. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic configuration diagram of an inkjet printer according to a first embodiment. [Diagram 2] FIG. 2 is a schematic configuration diagram of an inkjet head and an ink circulation mechanism according to the first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the head chip according to the first embodiment. [Figure 4] 4 is a cross-sectional view corresponding to line IV-IV in FIG. 3. [Diagram 5] 5 is a cross-sectional view corresponding to the line VV in FIG. 4. [Figure 6] 6 is a cross-sectional view corresponding to the line VI-VI in FIG. 5. [Figure 7] 7 is a cross-sectional view corresponding to the line VII-VII in FIG. 5. [Figure 8] FIG. 4 is a bottom view of the actuator plate according to the first embodiment. [Figure 9] FIG. 2 is a plan view of the actuator plate according to the first embodiment. [Figure 10]FIG. 2 is a plan view of a cover plate according to the first embodiment. [Figure 11] 4 is a flowchart for explaining a method for manufacturing the head chip according to the first embodiment. [Figure 12] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 13] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 14] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 15] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 16] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 17] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 18] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 19] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 20] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 21] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 22] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 23] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 24] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Diagram 25] 2A to 2C are process diagrams illustrating a manufacturing method of the head chip according to the first embodiment. [Figure 26] FIG. 11 is a cross-sectional view of a head chip according to a second embodiment. [Figure 27] FIG. 11 is a cross-sectional view of a head chip according to a third embodiment. [Figure 28] FIG. 11 is a cross-sectional view of a head chip according to a fourth embodiment. [Figure 29] FIG. 11 is a cross-sectional view of a head chip according to a fourth embodiment. [Diagram 30] FIG. 13 is a plan view of a cover plate according to a fourth embodiment. [Diagram 31] FIG. 13 is an explanatory diagram of a head chip according to a fourth embodiment. [Diagram 32] FIG. 13 is a cross-sectional view of a head chip according to a fifth embodiment. [Diagram 33] FIG. 13 is a cross-sectional view of a head chip according to a fifth embodiment. [Diagram 34] FIG. 13 is a plan view of an actuator plate according to a fifth embodiment. [Diagram 35] FIG. 13 is a plan view of a cover plate according to a fifth embodiment. [Diagram 36] FIG. 13 is a cross-sectional view of a head chip according to a modified example of the fifth embodiment. [Figure 37] FIG. 11 is a cross-sectional view of a head chip according to a modified example. [Figure 38] FIG. 11 is a cross-sectional view of a head chip according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. In the embodiments and modified examples described below, the same reference numerals may be used to designate corresponding configurations, and the description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly indicate such arrangements, but also indicate a state in which the components are relatively displaced with a tolerance or an angle or distance to the extent that the same function is obtained. In the following embodiment, an inkjet printer (hereinafter, simply referred to as a printer) that uses ink (liquid) to record on a recording medium will be taken as an example for description. In the drawings used in the following description, the scale of each component has been appropriately changed so that each component can be recognized.

[0020] (First embodiment) [Printer 1] FIG. 1 is a schematic diagram of a printer 1. A printer (liquid jet recording apparatus) 1 shown in FIG. 1 includes a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head (liquid jet head) 5, an ink circulation mechanism 6, and a scanning mechanism .

[0021] In the following explanation, an X, Y, Z Cartesian coordinate system is used as necessary. In this case, the X direction coincides with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper, etc.). The Y direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction indicates the height direction (gravity direction) perpendicular to the X and Y directions. In the following explanation, the X, Y, and Z directions will be explained with the arrows on the figures as the plus (+) side and the opposite side to the arrows as the minus (-) side. In this specification, the +Z side corresponds to the upward direction of gravity, and the -Z side corresponds to the downward direction of gravity.

[0022] The transport mechanisms 2 and 3 transport the recording medium P to the +X side. The transport mechanisms 2 and 3 each include a pair of rollers 11 and 12 extending in the Y direction, for example. The ink tanks 4 each contain ink of four colors, for example, yellow, magenta, cyan, and black. Each inkjet head 5 is configured to be capable of ejecting ink of one of the four colors, yellow, magenta, cyan, or black, according to the ink tank 4 connected thereto.

[0023] FIG. 2 is a schematic diagram of the ink-jet head 5 and the ink circulation mechanism 6. As shown in FIG. 1 and 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 includes a circulation flow path 23 having an ink supply pipe 21 and an ink discharge pipe 22, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22.

[0024] The pressure pump 24 pressurizes the inside of the ink supply pipe 21, and sends ink to the inkjet head 5 through the ink supply pipe 21. As a result, the ink supply pipe 21 side relative to the inkjet head 5 is under positive pressure. The suction pump 25 reduces the pressure inside the ink discharge tube 22 and sucks ink from the inkjet head 5 through the ink discharge tube 22. This creates a negative pressure on the ink discharge tube 22 side relative to the inkjet head 5. By driving the pressure pump 24 and the suction pump 25, the ink can be circulated between the inkjet head 5 and the ink tank 4 through the circulation flow path 23.

[0025] 1, the scanning mechanism 7 causes the inkjet head 5 to scan back and forth in the Y direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y direction, and a carriage 29 movably supported by the guide rail 28.

[0026] <Inkjet head 5> The inkjet head 5 is mounted on a carriage 29. In the illustrated example, a plurality of inkjet heads 5 are mounted side by side in the Y direction on one carriage 29. The inkjet head 5 includes a head chip 50, an ink supply unit (not shown) that connects the ink circulation mechanism 6 and the head chip 50, and a control unit (not shown) that applies a drive voltage to the head chip 50.

[0027] <Head chip 50> Fig. 3 is an exploded perspective view of head chip 50. Fig. 4 is a cross-sectional view of head chip 50 corresponding to line IV-IV in Fig. 3. Fig. 5 is a cross-sectional view of head chip 50 corresponding to line VV in Fig. 4. 3 to 5 is a so-called circulation type side shoot head chip 50 that circulates ink between ink tank 4 and ejects ink from the center of pressure chamber 61 (described later) in the extension direction (Y direction). Head chip 50 includes nozzle plate 51, flow path member 52, film 53, actuator plate 54, and cover plate 55. In the following description, in the Z direction, the direction from nozzle plate 51 to cover plate 55 (+Z side) may be referred to as the upper side, and the direction from cover plate 55 to nozzle plate 51 (-Z side) may be referred to as the lower side.

[0028] <Flow path member 52> 3, the flow path member 52 is in the form of a plate with its thickness direction in the Z direction. The flow path member 52 is made of a material having ink resistance. Examples of such materials that can be used include metals, metal oxides, glass, resins, and ceramics. The flow path member 52 is formed with a flow path 60 through which the ink flows, and a plurality of pressure chambers 61 that communicate with the flow path 60 and contain the ink. The flow paths 60 and the pressure chambers 61 penetrate the flow path member 52 in the Z direction.

[0029] The pressure chambers 61 are arranged at intervals in the X direction. Therefore, the portions of the flow path member 52 located between the adjacent pressure chambers 61 constitute partition walls 62 that separate the adjacent pressure chambers 61 in the X direction. Each pressure chamber 61 is formed in a groove shape extending linearly in the Y direction. Each pressure chamber 61 penetrates the flow path member 52 over the entire area in the Y direction. However, the pressure chamber 61 may penetrate the flow path member 52 in a part in the Y direction. In the first embodiment, a configuration in which the channel extension direction coincides with the Y direction will be described, but the channel extension direction may intersect with the Y direction. The planar shape of the pressure chamber 61 is not limited to a rectangular shape (a shape in which one of the X direction and the Y direction is the long side direction and the other is the short side direction). The planar shape of the pressure chamber 61 may be a polygonal shape such as a square shape or a triangular shape, a circular shape, an elliptical shape, or the like.

[0030] The flow passage 60 includes an inlet side common flow passage 64 , an inlet side communication passage 65 , an outlet side common flow passage 66 , and an outlet side communication passage 67 . The inlet-side common flow path 64 extends in the X direction through a portion of the flow path member 52 that is located on the +Y side with respect to each pressure chamber 61. The -X side end of the inlet-side common flow path 64 is connected to an inlet port (not shown). The inlet port is directly or indirectly connected to the ink supply tube 21 (see FIG. 2). That is, the ink flowing through the ink supply tube 21 is supplied to the inlet-side common flow path 64 through the inlet port. The inlet side communication passages 65 connect the inlet side common flow path 64 and each pressure chamber 61. Specifically, each inlet side communication passage 65 branches off toward the -Y side from a portion of the inlet side common flow path 64 that overlaps with each pressure chamber 61 when viewed from the X direction. The -Y side end of the inlet side communication passage 65 is connected to the pressure chamber 61.

[0031] The outlet side common flow path 66 extends in the X direction through a portion of the flow path member 52 that is located on the -Y side with respect to each pressure chamber 61. The +X side end of the outlet side common flow path 66 is connected to an outlet port (not shown). The outlet port is directly or indirectly connected to the ink discharge tube 22 (see FIG. 2). That is, the ink flowing inside the outlet side common flow path 66 is supplied to the ink discharge tube 22 through the outlet port. The outlet side communication passages 67 connect between the outlet side common flow path 66 and each pressure chamber 61. Specifically, each outlet side communication passage 67 branches off toward the +Y side from a portion of the outlet side common flow path 66 that overlaps with each pressure chamber 61 when viewed from the X direction. The +Y side end of the outlet side communication passage 67 is connected to the pressure chamber 61.

[0032] <Nozzle plate 51> 4 and 5, the nozzle plate 51 is fixed to the lower surface of the flow path member 52 by adhesion or the like. The nozzle plate 51 closes the lower end openings of the flow paths 60 and the pressure chambers 61. In the first embodiment, the nozzle plate 51 is formed of a metal material such as SUS or Ni-Pd. However, the nozzle plate 51 may have a single layer structure or a multilayer structure made of a resin material (e.g., polyimide), glass, silicon, or the like in addition to the metal material.

[0033] The nozzle plate 51 is formed with a plurality of nozzle holes 51a penetrating the nozzle plate 51 in the Z direction. The nozzle holes 51a are arranged at intervals in the X direction. Each nozzle hole 51a communicates with a corresponding pressure chamber 61 at the center in the X direction and the Y direction. In the first embodiment, each nozzle hole 51a is formed in a tapered shape such that the inner diameter gradually decreases from the top to the bottom.

[0034] <Film 53> The film 53 is fixed to the upper surface of the flow path member 52 by adhesion or the like. The film 53 is disposed over the entire upper surface of the flow path member 52. As a result, the film 53 closes the upper end openings of the flow paths 60 and the pressure chambers 61. The film 53 is formed from a material that is insulating and resistant to ink and is elastically deformable. As such a material, the film 53 is formed from, for example, a resin material (polyimide-based, epoxy-based, polypropylene-based, etc.).

[0035] <Actuator plate 54> The actuator plate 54 is fixed by adhesive or the like to the upper surface of the film 53 with the Z direction as the thickness direction. The actuator plate 54 faces each pressure chamber 61 in the Z direction with the film 53 sandwiched therebetween. Note that the actuator plate 54 is not limited to a configuration in which it collectively covers each pressure chamber 61, and may be provided for each pressure chamber 61 individually.

[0036] The actuator plate 54 is made of a piezoelectric material such as PZT (lead zirconate titanate), etc. The actuator plate 54 is set so that the polarization direction faces one direction on the +Z side.

[0037] Recesses 68 are formed in the actuator plate 54 at portions that overlap with the pressure chambers 61 in plan view. The recesses 68 are recessed upward with respect to the lower surface of the actuator plate 54. Specifically, the recesses 68 extend in the Y direction along the pressure chambers 61 in plan view. The recesses 68 are formed in a rectangular shape when viewed from the Y direction. Note that in the illustrated example, the portions of the above-mentioned film 53 that correspond to the recesses 68 extend along the inner surface of the recesses 68.

[0038] Groove portions 69 are formed in portions of the actuator plate 54 located on both sides of the recess 68 in the X direction. The groove portions 69 overlap with the partition walls 62 in a plan view. The groove portions 69 are recessed downward with respect to the upper surface of the actuator plate 54. The groove portions 69 extend in the Y direction along the recess 68. In the illustrated example, the dimension of the groove portions 69 in the Z direction is larger than the dimension of the recess 68 in the Z direction. The dimension of the groove portions 69 in the X direction is smaller than the dimension of the recess 68 in the X direction. The dimension of the groove portions 69 in the Y direction is equal to the dimension of the recess 68 in the Y direction.

[0039] As shown in Figs. 5 and 6, a first through hole 54a and a second through hole 54b are formed in the actuator plate 54. Each through hole 54a, 54b is formed in a tapered shape in which the inner diameter (inner dimension) in at least the Y direction gradually decreases from the top to the bottom. However, the inner diameter of each through hole 54a, 54b may be uniform over the entire Z direction. In addition, the planar shape of each through hole 54a, 54b can be appropriately changed to a circular shape, an elliptical shape, a polygonal shape, or the like. Each through hole 54a, 54b may have the same shape or different shapes.

[0040] The first through holes 54a penetrate in the Z direction through portions of the actuator plate 54 that overlap with the -Y side ends of the pressure chambers 61 in a plan view. The second through holes 54b penetrate in the Z direction through portions of the actuator plate 54 that overlap with the +Y side ends of the pressure chambers 61 in a plan view. The corresponding first through holes 54a and second through holes 54b are formed in positions facing each other in the Y direction. The first through holes 54a and second through holes 54b may be provided in positions shifted in the X direction with respect to the pressure chambers 61 in a plan view. The corresponding first through holes 54a and second through holes 54b may be provided so as not to face each other in the Y direction (shifted in the X direction).

[0041] <Cover plate 55> The cover plate 55 is fixed by adhesion or the like to the upper surface of the actuator plate 54, with the Z direction being the thickness direction. The thickness of the cover plate 55 in the Z direction is thicker than the actuator plate 54, the flow path member 52, and the film 53. In the first embodiment, the cover plate 55 is formed from an insulating material (for example, metal oxide, glass, resin, ceramics, etc.).

[0042] A conductive portion 55a is formed in the cover plate 55. The conductive portion 55a is formed in a portion of the cover plate 55 that is located between the first through hole 54a and the second through hole 54b in the Y direction. In the example shown in the figure, the conductive portion 55a is formed in a portion that is located closer to the second through hole 54b. However, the position of the conductive portion 55a can be changed as appropriate.

[0043] Fig. 6 is a cross-sectional view corresponding to the line VI-VI in Fig. 5. Fig. 7 is a cross-sectional view corresponding to the line VII-VII in Fig. 6. As shown in FIGS. 5 to 7, the conductive portion 55a has an upper recess (first recess) 71 and a lower recess (second recess) 72. The upper recesses 71 are formed in the cover plate 55 at the same positions in the X direction as the first through holes 54a and the second through holes 54b. That is, a plurality of upper recesses 71 are formed at intervals in the X direction. However, the conductive portion 55a may be disposed offset in the X direction with respect to the through holes 54a and 54b.

[0044] The upper recess 71 opens at the upper surface of the cover plate 55. That is, the upper recess 71 constitutes the upper end opening of the conductive portion 55a. In plan view, the upper recess 71 is formed in a rectangular shape (or an oval shape) with the Y direction as the major axis direction, for example. In cross-sectional view, the upper recess 71 is formed in a tapered shape in which the inner diameter (inner dimension) in at least the Y direction gradually decreases from the top to the bottom. The shape of the upper recess 71 in plan view can be appropriately changed to a perfect circle, a polygonal shape, or the like.

[0045] The lower recess 72 opens on the lower surface of the cover plate 55. That is, the lower recess 72 constitutes the lower end opening of the conductive portion 55a. The lower recess 72 is formed in a groove shape extending in the X direction so as to span all the upper recesses 71. The lower recess 72 communicates with the upper recess 71 through a portion overlapping with the upper recess 71 in a plan view. The portion of the conductive portion 55a where the upper recess 71 and the lower recess 72 communicate with each other constitutes a through hole 73 penetrating the cover plate 55 in the Z direction. The lower recess 72 does not necessarily have to span all the upper recesses 71, but may at least span between adjacent upper recesses 71.

[0046] The lower recess 72 has a dimension in the Y direction equal to the dimension in the Y direction of the lower end opening of the upper recess 71. In the illustrated example, the dimension in the Y direction of the lower recess 72 is uniform throughout the Z direction. As shown in FIG. 5, of a pair of inner surfaces of the lower recess 72 facing each other in the Y direction, the +Y side inner surface (first inner surface portion) 72a is connected without a step from the same position in a plan view as the portion located on the +Y side of the lower end opening edge of the upper recess 71 (hereinafter referred to as the +Y side opening edge). Therefore, the +Y side inner surface 72a is located within the dimensional range of the lower end opening of the upper recess 71 as viewed in the Z direction, and extends continuously to the inner surface of the upper recess 71. Of the pair of inner surfaces facing each other in the Y direction in the lower recess 72, the -Y side inner surface (first inner surface portion) 72b is connected without a step to a portion located on the -Y side of the lower end opening edge of the upper recess 71 (hereinafter referred to as the -Y side opening edge). Therefore, the +Y side inner surface 72b is located within the dimensional range of the lower end opening of the upper recess 71 as viewed from the Z direction, and extends continuously to the inner surface of the upper recess 71.

[0047] 6, the +X side end of the lower recess 72 is located on the +X side with respect to the upper recess 71 located furthest on the +X side among the upper recesses 71. That is, the +X side inner surface (second inner surface portion) 72c of the inner surface of the lower recess 72 is located on the +X side with respect to any of the upper recesses 71. The -X side end of the lower recess 72 is located on the -X side with respect to the upper recess 71 located furthest on the -X side among the upper recesses 71. That is, among the inner surfaces of the lower recess 72, the -X side inner surface (second inner surface portion) 72d is located on the -X side with respect to any of the upper recesses 71.

[0048] 5, in the first embodiment, the dimension in the Z direction of the upper recess 71 is larger than the dimension in the Z direction of the lower recess 72. Furthermore, the opening area of ​​the lower end opening of the lower recess 72 is larger than the opening area of ​​the upper end opening of one of the upper recesses 71. However, the opening area of ​​the lower end opening of the lower recess 72 may be equal to or smaller than the opening area of ​​the upper end opening of one of the upper recesses 71.

[0049] Next, various wirings formed on the head chip 50 will be described. As shown in FIG. 4, the actuator plate 54 is provided with common wiring 81 and individual wiring 82 as drive wiring. The common wiring 81 includes a first common electrode 81a, a second common electrode 81b, a third common electrode 81c, a bottom surface wiring 81d (see FIG. 7), an top surface wiring 81e (see FIG. 8), and a first common through wiring 81f (see FIG. 5).

[0050] FIG. 8 is a bottom view of the actuator plate 54. As shown in FIG. 4 and FIG. 8, the first common electrodes 81a are formed on the lower surface of the actuator plate 54 at positions overlapping with the partition walls 62 and the grooves 69 when viewed from the Z direction. In the first embodiment, the first common electrode 81a located on the +X side of the first common electrodes 81a corresponding to one pressure chamber 61 is shared with the first common electrode 81a located on the -X side of the first common electrodes 81a of another pressure chamber 61 adjacent to the one pressure chamber 61 on the +X side. On the other hand, the first common electrode 81a located on the -X side of the first common electrodes 81a corresponding to one pressure chamber 61 is shared with the first common electrode 81a located on the +X side of the first common electrodes 81a corresponding to the other pressure chamber 61 adjacent to the one pressure chamber 61 on the -X side. Note that the first common electrodes 81a may be separated from each other between the pressure chambers 61.

[0051] FIG. 9 is a plan view of the actuator plate 54. As shown in FIG. 4 and 9, the second common electrode 81b is disposed on the upper surface of the actuator plate 54 at a position that overlaps with the corresponding pressure chamber 61 when viewed from the Z direction, but does not overlap with the first common electrode 81a when viewed from the Z direction. The second common electrode 81b extends linearly in the Y direction with a length equal to that of the pressure chamber 61. The third common electrode 81c is formed over the entire inner surface of each groove 69. That is, the third common electrode 81c is disposed on both sides in the X direction of the second common electrode 81b. Note that it is sufficient that the third common electrode 81c is formed on at least a part of the inner surface of the groove 69.

[0052] 8, the bottom surface wiring 81d is connected collectively to each of the first common electrodes 81a on the bottom surface of the actuator plate 54. The bottom surface wiring 81d extends in the X direction while being connected to the -Y side end of each of the first common electrodes 81a.

[0053] 9, the upper surface wiring 81e is connected to the second common electrode 81b and the third common electrode 81c on the upper surface of the actuator plate 54. The upper surface wiring 81d extends in the X direction while connecting the -Y side ends of the second common electrode 81b and the third common electrode 81c to each other.

[0054] As shown in FIG. 5, the first common through wiring 81f connects the lower surface wiring 81d and the upper surface wiring 81e. The first common through wiring 81f is formed on the inner surface of the first through hole 54a over the entire length in the Z direction at least in the portion facing the -Y side. The lower end edge of the first common through wiring 81f is connected to the lower surface wiring 81d at the lower end opening edge of the first through hole 54a. The upper end edge of the first common through wiring 81f is connected to the upper surface wiring 81e at the upper end opening edge of the first through hole 54a. Note that the first common through wiring 81f may be formed partially on any of the inner surfaces of the first through hole 54a as long as it connects the lower surface wiring 81d and the upper surface wiring 81e.

[0055] As shown in FIG. 4, the individual wiring 82 includes an individual electrode 82a, a lower surface wiring 82b (see FIG. 8), an upper surface wiring 82c (see FIG. 9), and a first individual through wiring 82d (see FIG. 5).

[0056] As shown in FIG. 4 and FIG. 7, the individual electrode 82a is formed at least on the inner surface of the recess 68. In the illustrated example, the individual electrode 82a is formed over the entire inner surface of the recess 68. The individual electrode 82a is formed between the first common electrodes 81a in a plan view. The individual electrode 82a extends in the Y direction with a gap in the X direction from each of the first common electrodes 81a. The entire individual electrode 82a overlaps with the corresponding pressure chamber 61 when viewed from the Z direction. In this case, at least a part of the individual electrode 82a overlaps with the second common electrode 81b when viewed from the Z direction. Note that the individual electrode 82a may be formed on at least a part of the inner surface of the recess 68. In addition to the inner surface of the recess 68, the individual electrode 82a may be connected to a portion of the lower surface of the actuator plate 54 that is located around the recess 68.

[0057] 8, the bottom surface wiring 82b is connected to the +Y side end of the individual electrode 82a on the bottom surface of the actuator plate 54. The bottom surface wiring 82b corresponding to adjacent pressure chambers 61 are separated from each other. As shown in FIG. 9, the upper surface lead-out wiring 82c is formed on the upper surface of the actuator plate 54 along the −Y side edge of the upper opening edge of the second through-hole 54b.

[0058] As shown in FIG. 5 and FIG. 7, the first individual through wiring 82d connects the lower surface wiring 82b and the upper surface wiring 82c. The first individual through wiring 82d is formed on the inner surface of the second through hole 54b over the entire length in the Z direction at least in the portion facing the +Y side. The lower end edge of the first individual through wiring 82d is connected to the lower surface wiring 82b at the lower end opening edge of the second through hole 54b. The upper end edge of the first individual through wiring 82d is connected to the upper surface wiring 82c at the upper end opening edge of the second through hole 54b. Note that the first individual through wiring 82d does not have to be formed around the entire inner surface of the second through hole 54b as long as it connects the lower surface wiring 82b and the upper surface wiring 82c.

[0059] FIG. 10 is a plan view of the cover plate 55. As shown in FIG. As shown in FIGS. 5 and 10, the cover plate 55 is formed with a second common through wire 85 and a second individual through wire 86 as connection wires, and a common pad 87 and an individual pad 88 as terminal wires. The second common through wiring 85 connects the second common electrode 81b and the common pad 87. The second common through wiring 85 is formed on the inner surface of each through hole 73 over the entire length in the Z direction. Specifically, the upper half of the second common through wiring 85 is formed on at least a portion of the inner surface of the upper recess 71 that is located on the -Y side. The upper end edge of the second common through wiring 85 is located on the upper end opening edge of the upper recess 71 (through hole 73). The lower half of the second common through wiring 85 is formed on the -Y side inner surface 72b of the inner surface of the lower recess 72. The upper and lower halves of the second common through wiring 85 are connected at the boundary portion between the upper recess 71 and the lower recess 72. The lower end edge of the second common through wiring 85 is located on the lower end opening edge of the lower recess 72 (through hole 73). The lower end edge of the second common through wiring 85 is connected to a portion of the upper surface lead-out wiring 81e that is exposed through the through hole 73 at the lower end opening edge of the through hole 73. The second common through-wire 85 may be connected to either the second common electrode 81b or the third common electrode 81c.

[0060] 6, the second common through wiring 85 is not formed in the portion of the lower recess 72 located between the through holes 73. In other words, the adjacent second common through wirings 85 are separated from each other by the portion of the lower recess 72 located between the through holes 73.

[0061] 5 and 10, the common pad 87 is formed on the upper surface of the cover plate 55. The common pad 87 extends in the Y direction on a portion of the upper surface of the cover plate 55 that overlaps with the pressure chamber 61 when viewed from the Z direction. The common pad 87 is connected to the upper edge of the second common through wiring 85 at the upper opening edge of the through hole 73.

[0062] As shown in FIG. 5 and FIG. 7, the second individual through wiring 86 connects the second individual through wiring 82e and the individual pad 88. The second individual through wiring 86 is formed on the inner surface of each through hole 73 over the entire length in the Z direction. Specifically, the upper half of the second individual through wiring 86 is formed on at least a portion of the inner surface of the upper recess 71 that is located on the +Y side. The upper end edge of the second individual through wiring 86 is located on the upper end opening edge of the upper recess 71 (through hole 73). The lower half of the second individual through wiring 86 is formed on the +Y side inner surface 72a of the inner surface of the lower recess 72. The upper and lower halves of the second individual through wiring 86 are connected at the boundary portion between the upper recess 71 and the lower recess 72. The lower end edge of the second individual through wiring 86 is located on the lower end opening edge of the lower recess 72 (through hole 73). The lower end edge of the second individual through wire 86 is connected to a portion of the upper surface lead-out wire 82 c that is exposed through the through hole 73 at the lower opening edge of the through hole 73 .

[0063] 7, in the lower recess 72, the second individual through wirings 86 are not formed in the portions located between the through holes 73. In other words, adjacent second individual through wirings 86 are separated from each other by the portions of the lower recess 72 located between the through holes.

[0064] 10, the individual pads 88 are formed on the upper surface of the cover plate 55. The individual pads 88 extend in the Y direction on a portion of the upper surface of the cover plate 55 that overlaps with the pressure chambers 61 when viewed from the Z direction. The individual pads 88 are connected to the upper edge of the second individual through wirings 86 at the upper opening edge of the through hole 73. In this embodiment, the common pad 87 and the individual pads 88 extend in directions spaced apart from each other in the Y direction, sandwiching the through hole 73 therebetween.

[0065] A flexible printed circuit board (not shown) serving as external wiring is pressure-bonded to the upper surface of the cover plate 55. The flexible printed circuit board is mounted on the common pad 87 and the individual pads 88 on the upper surface of the cover plate 55.

[0066] [Printer 1 operation method] Next, a case where characters, figures, etc. are recorded on a recording medium P using the printer 1 configured as described above will be described below. 1 are each fully filled with ink of a different color. Also, the ink in the ink tanks 4 is filled in the inkjet head 5 via the ink circulation mechanism 6.

[0067] When the printer 1 is operated in this initial state, the recording medium P is conveyed to the +X side while being sandwiched between the rollers 11 and 12 of the conveying mechanisms 2 and 3. At the same time, the carriage 29 moves in the Y direction, causing the inkjet head 5 mounted on the carriage 29 to move back and forth in the Y direction. While the inkjet heads 5 are moving back and forth, ink is appropriately ejected from each inkjet head 5 onto the recording medium P. In this way, characters, images, etc. can be recorded on the recording medium P.

[0068] The movement of each ink-jet head 5 will now be described in detail. In the inkjet head 5 of the circulation side chute type as in the first embodiment, first, the pressurizing pump 24 and the suction pump 25 shown in FIG. 2 are operated to circulate ink in the circulation flow path 23. In this case, the ink circulating in the ink supply tube 21 is supplied into each pressure chamber 61 through the inlet side common flow path 64 and the inlet side communication path 65. The ink supplied into each pressure chamber 61 circulates in the Y direction in each pressure chamber 61. Thereafter, the ink is discharged into the outlet side common flow path 66 through the outlet side communication path 67, and then returned to the ink tank 4 through the ink discharge tube 22. In this way, ink can be circulated between the inkjet head 5 and the ink tank 4.

[0069] When the inkjet head 5 starts to move back and forth due to the movement of the carriage 29 (see FIG. 1), a drive voltage is applied between the common electrodes 81a, 81b and the individual electrodes 82a, 82b via the flexible printed circuit board. At this time, the drive voltage is applied with the common electrodes 81a to 81c at a reference potential GND and the individual electrode 82a at a drive potential Vdd.

[0070] Application of the drive voltage generates a potential difference in the X direction between the first common electrode 81a and the individual electrodes 82a. Due to the potential difference generated in the X direction, the actuator plate 54 undergoes thickness slip deformation in the Z direction due to shear mode. Specifically, an electric field is generated between the first common electrode 81a and the individual electrodes 82a in directions away from each other in the X direction. As a result, the portions of the actuator plate 54 corresponding to each pressure chamber 61 shear upward from both ends toward the center in the X direction.

[0071] On the other hand, a potential difference occurs in the Z direction between the individual electrode 82a and the second common electrode 81b, and between the individual electrode 82a and the third common electrode 81c. Due to the potential difference occurring in the Z direction, an electric field is generated in the actuator plate 54 in a direction parallel to the polarization direction (Z direction). As a result, the actuator plate 54 expands and contracts in the Z direction due to the bend mode. That is, in the head chip 50 of the first embodiment, the deformations caused by the shear mode and the bend mode of the actuator plate 54 both extend in the Z direction. Specifically, when the driving voltage is applied, the actuator plate 54 deforms in a direction away from the pressure chamber 61. This causes the volume in the pressure chamber 61 to expand. After that, when the driving voltage is set to zero, the actuator plate 54 restores, and the volume in the pressure chamber 61 tries to return to the original volume. In the process of the actuator plate 54 restoring, the pressure in the pressure chamber 61 increases, and the ink in the pressure chamber 61 is ejected to the outside through the nozzle hole 51a. When the ink ejected to the outside lands on the recording medium P, print information is recorded on the recording medium P.

[0072] <Method of Manufacturing Head Chip 50> Next, a method for manufacturing the above-mentioned head chip 50 will be described. Fig. 11 is a flowchart for explaining the method for manufacturing head chip 50. Figs. 12 to 25 are process diagrams for explaining the method for manufacturing head chip 50, and are cross-sectional views corresponding to Figs. 4 and 5. For convenience, the following description will be given taking as an example a case in which head chip 50 is manufactured at the chip level. As shown in FIG. 11, the manufacturing method for the head chip 50 includes a first actuator processing step S01, a first cover processing step S02, a first bonding step S03, a second actuator processing step S04, a second cover processing step S05, a second bonding step S06, a first flow path member processing step S07, a third bonding step S08, a second flow path member processing step S09, and a fourth bonding step S10.

[0073] 12, in the first actuator processing step S01, first, recesses 100, 101 to become the first through-hole 54a and the second through-hole 54b are formed (recess formation step). Specifically, a mask pattern is formed on the upper surface of the actuator plate 54, in which the regions for forming the first through-hole 54a and the second through-hole 54b are opened. Then, a sandblasting process or the like is performed on the upper surface of the actuator plate 54 through the mask pattern. As a result, the recesses 100, 101 that are recessed from the upper surface are formed in the actuator plate 54. The recesses 100, 101 may be formed by a dicing process, a precision drilling process, an etching process, or the like.

[0074] 13, in the first actuator processing step S01, grooves 69 are formed in the actuator plate 54 (groove forming step). Specifically, the grooves 69 are formed by performing a dicing process or the like on the upper surface of the actuator plate 54. The grooves 69 have a smaller dimension in the Z direction than the recesses 100, 101. The groove forming step may be performed prior to the recess forming step.

[0075] 14, in a first actuator processing step S01, the portions of the various wirings that are to be located on the upper surface of the actuator plate 54 are formed (first wiring formation step). In the first wiring formation step, a mask pattern having openings in areas where the wirings are to be formed is first formed on the upper surface of the actuator plate 54. Next, an electrode material is formed on the actuator plate 54 by, for example, oblique deposition. The electrode material is formed on the actuator plate 54 through the openings in the mask pattern. As a result, various wirings are formed on the upper surface of the actuator plate 54 and on the inner surfaces of the recesses 100 and 101.

[0076] In the first cover processing step S02, the conductive portion 55a is formed in the cover plate 55. The first cover processing step S02 includes an upper recess forming step and a lower recess forming step.

[0077] 15, in the upper recess forming step, a mask pattern is formed on the upper surface of the cover plate 55, the mask pattern having an opening for forming the upper recess 71. Then, the upper surface of the cover plate 55 is sandblasted through the mask pattern. As a result, the cover plate 55 has blast marks 110 recessed into the upper surface.

[0078] Here, when the upper recess 71 is formed by sandblasting, the blast mark 110 is formed in a tapered shape with the inner diameter gradually decreasing from the upper end opening to a predetermined range in the Z direction. However, when the depth (dimension in the Z direction) of the blast mark 110 exceeds the predetermined range, the inner diameter may expand once and then decrease again. As a result, a constricted portion 112 is formed in the middle part of the blast mark 110 in the Z direction, especially in the part facing the Y direction. Once the constricted portion 112 is formed, when an electrode material is formed on the inner surface of the blast mark 110, it is difficult for the electrode material to flow around the part of the blast marks 110, 111 located below the constricted portion 112. This may result in a decrease in yield, etc.

[0079] Therefore, in the first cover processing step S02, as shown in FIG. 16, after the upper recess forming step, the lower recess forming step is performed. In the lower recess forming step, dicing is performed on the lower surface of the cover plate 55. The width of the dicer 120 used in the lower recess forming step is set to be equal to or larger than the dimension of the constricted portion 112. When forming the lower recess 72, the dicer 115 is advanced to a position on the lower surface of the cover plate 55 that overlaps in plan view with at least one of the constricted portions 112 facing each other in the Y direction among the blast marks 110, with the rotation axis line coinciding with the Y direction. Then, the dicer 115 is caused to travel in the X direction so as to cross each blast mark 110. At this time, dicing is performed with the dicer 115 advanced to above the constricted portion 112 in the blast marks 110. As a result, the conductive portion 55a is formed with the constricted portion 112 removed. That is, the portion machined by dicer 115 in the lower recess forming step constitutes lower recess 72 , and the portion of blast mark 110 remaining after the lower recess forming step constitutes upper recess 71 .

[0080] As shown in FIG. 17, in the first bonding step S03, the cover plate 55 is attached to the upper surface of the actuator plate 54 by adhesive or the like. As a result, the conductive portion 55a and the recess 100 communicate with each other. In the first bonding step S03, the excess adhesive that is swept away when the actuator plate 54 and the cover plate 55 are pressure-bonded together is accommodated in the lower recess 72. That is, in the first embodiment, the lower recess 72 extends in the X direction so as to straddle all the upper recesses 71 and 76. Therefore, the excess adhesive is evenly accommodated in the lower recess 72. In addition, it is easier to ensure the opening area of ​​the lower recess 72 compared to when the lower recess 72 communicates only with the upper recess 71. As a result, the adhesive is prevented from flowing into the through hole 73 in a concentrated manner.

[0081] 18, in the second actuator processing step S04, a grinding process is performed on the lower surface of the actuator plate 54 (grinding step). At this time, the actuator plate 54 is ground to a position where the recess 100 is open on the lower surface of the actuator plate 54 and the groove portion 69 is not open, thereby forming the first through hole 54a and the second through hole 54b.

[0082] 19, in a second actuator processing step S04, recesses 68 are formed in the lower surface of the actuator plate 54 (recess forming step). The recesses 68 are formed by, for example, performing a dicer process on the lower surface of the actuator plate 54.

[0083] 20, various wirings such as the first common electrode 81a and the first individual electrodes 82a are formed on the lower surface of the actuator plate 54 (second wiring formation process). In the second wiring formation process, a mask pattern having openings in areas where the wirings are to be formed is first formed on the lower surface of the actuator plate 54. Then, an electrode material is formed on the actuator plate 54 by, for example, deposition. The electrode material is formed on the actuator plate 54 through the openings in the mask pattern.

[0084] Next, as shown in FIG. 21, in the second cover processing step S05, the through wirings 85, 86 and the pads 87, 88 are formed on the cover plate 55 (third wiring forming step). Specifically, a mask pattern is first formed on the upper surface of the cover plate 55, in which the formation regions of the through wirings 85, 86 and the pads 87, 88 are opened. Next, an electrode material is formed on the cover plate 55 by, for example, oblique deposition from the Y direction. A part of the electrode material is formed on the upper surface of the cover plate 55 through the opening of the mask pattern. As a result, the pads 87, 88 are formed. In addition, a part of the electrode material enters the conductive portion 55a through the opening of the mask pattern and the upper end opening of the conductive portion 55a (upper recess 71). The electrode material that has entered the conductive portion 55a adheres to the inner surface of each through hole 73. As a result, the through wirings 85, 86 are formed on the inner surface of each through hole 73.

[0085] Here, in the conductive portion 55a, the lower recess 72 extends in the X direction so as to straddle all the upper recesses 71. Therefore, the electrode material is less likely to flow into the portion of the lower recess 72 located between the adjacent upper recesses 71. That is, the portion of the cover plate 55 located between the adjacent upper recesses 71 functions as a mask for the portion of the lower recess 72 located between the adjacent upper recesses 71. As a result, the second common through wirings 85 are formed in a state in which they are separated from each other between the adjacent through holes 73.

[0086] As shown in FIG. 22, in the second bonding step S06, the film 53 is attached to the lower surface of the actuator plate 54 with an adhesive or the like. 23, in the flow path member first processing step S07, a flow path 60 (see FIG. 6) and a pressure chamber 61 are formed in the flow path member 52. The flow path 60 and the pressure chamber 61 are formed by performing, for example, a dicing process or a sandblasting process on the flow path member 52. Then, a portion of the flow path member 52 that separates adjacent pressure chambers 61 remains as a partition wall 62.

[0087] As shown in FIG. 24, in the third bonding step S08, the flow path member 52 is attached to the lower surface of the film 53 with an adhesive or the like.

[0088] 25, in a second flow path member processing step S09, a grinding process is performed on the lower surface of the flow path member 52 (grinding step). At this time, the flow path member 52 is ground to a position where the flow paths 60 and the pressure chambers 61 open on the lower surface of the flow path member 52.

[0089] In the fourth bonding step S10, the nozzle plate 51 is attached to the lower surface of the flow path member 52 in a state in which the nozzle holes 51a and the pressure chambers 61 are aligned. Through the above steps, the head chip 50 is completed.

[0090] In this manner, in the head chip 50 of the first embodiment, a second common through wiring 85 connected to the common electrodes 81a to 81c and a second individual through wiring 86 connected to the individual electrode 82a are formed within the through hole 73 in a state separated from each other. According to this configuration, since two systems of wiring (second common through wiring 85 and second individual through wiring 86) are formed in a state separated from each other in one through hole 73, the number of through holes 73 formed in cover plate 55 can be reduced compared to the case where one system of wiring is formed for each through hole 73. Therefore, it is possible to improve the degree of freedom in design and to miniaturize head chip 50. By miniaturizing head chip 50, for example, when head chip 50 is produced at the wafer level, the number of cover plates 55 that can be obtained from one wafer can be increased. As a result, the cost of head chip 50 can be reduced.

[0091] In the head chip 50 of the first embodiment, the cover plate 55 is formed with an upper recess (first recess) 71 that opens on the upper surface (first surface facing the first side in the thickness direction) and a lower recess (second recess) 72 that opens on the lower surface (second surface facing the second side in the thickness direction) and communicates with the upper recess 71. The lower recess 72 includes a +Y side inner surface (first inner surface portion) 72a and a -Y side inner surface 72b that are located at the same position in a plan view with respect to the lower end opening edge (inner surface) of the upper recess 71, and a +X side inner surface (second inner surface portion) 72c and a -X side inner surface 72d that are located outside in the X direction with respect to the inner surface of the upper recess 71. According to this configuration, when forming the second common through wiring 85 and the second individual through wiring 86 through the upper end opening of the upper recess 71, it is easy to form continuous wiring over either the +Y side inner surface 72a or the -Y side inner surface 72b, as well as the inner surface of the upper recess 71. In addition, since the lower recess 72 has a +X side inner surface 72c and a -X side inner surface 72d located outside the inner surface of the upper recess 71 in the X direction, an outward protrusion is formed in the portion of the lower recess 72 located outside the upper recess 71 in the X direction. Therefore, when the actuator plate 54 and the cover plate 55 are bonded together, the outward protrusion functions as an adhesive reservoir. That is, compared to a case where the opening area of ​​the lower recess 72 is formed to be equal to that of the upper recess 71, adhesive can be stored in a portion other than the communication portion (through hole 73) between the upper recess 71 and the lower recess 72. This makes it possible to prevent the conduction between the common wiring 81 and the second common through wiring 85 from being interrupted by the adhesive, and the conduction between the common wiring 81 and the second common through wiring 85 can be stabilized. As a result, the yield can be improved.

[0092] In head chip 50 of the first embodiment, a plurality of upper recesses 71 are provided at intervals in the X direction (first direction), and lower recess 72 extends in the X direction so as to straddle two adjacent upper recesses 71 among the plurality of upper recesses 71. Y-side inner surfaces 72a, 72b are disposed at the same position as the inner surface of lower recess 72, and X-side inner surfaces 72c, 72d are located on the outer side in the X direction with respect to the inner surfaces of upper recesses 71, 75 among the inner surfaces of lower recess 72. According to this configuration, it is sufficient to provide one lower recess 72 for each of the multiple upper recesses 71. Therefore, it is possible to improve the manufacturing efficiency of the lower recess 72 compared to a case in which the lower recess 72 is separately formed corresponding to each upper recess 71.

[0093] In head chip 50 of the first embodiment, upper recess 71 is formed in a tapered shape in which the inner diameter decreases downward, and the dimension of upper recess 71 in the Z direction is larger than the dimension of lower recess 72 in the Z direction. According to this configuration, for example, when the second common through wiring 85 and the second individual through wiring 86 are formed through the upper end opening of the upper recess 71 by oblique deposition, the second common through wiring 85 and the second individual through wiring 86 can be easily formed continuously on the inner surface of the through hole 73. As a result, the yield can be improved and the cost of the head chip 50 can be reduced.

[0094] In head chip 50 of the first embodiment, common pad 87 and individual pads 88 are formed on the upper surface of cover plate 55, and extend in directions away from each other from the upper opening edge of through hole 73. According to this configuration, the common pad 87 and the individual pads 88 extend from the upper opening edge of one through hole 73, so that the wiring lengths of the common pad 87 and the individual pads 88 can be reduced and the common pad 87 and the individual pads 88 can be placed closer to each other than when they extend from the upper opening edges of separate through holes. This makes it possible to reduce the electrostatic capacitance of the head chip 50. As a result, the responsiveness of the head chip 50 can be improved and heat generation in the head chip 50 can be suppressed.

[0095] Since the inkjet head 5 and printer 1 of the first embodiment include the head chip 50 described above, it is possible to provide a small-sized, low-cost inkjet head 5 and printer 1.

[0096] Second embodiment FIG. 26 is a cross-sectional view of the head chip 50 according to the second embodiment, which corresponds to FIG. In head chip 50 shown in FIG. 26, the dimension of upper recess 71 in the Z direction is smaller than the dimension of lower recess 72 in the Z direction.

[0097] Here, the above-mentioned constricted portion 112 tends to be formed at a deeper position in the blast mark 110 as the inner diameter of the upper end opening of the blast mark 110 (upper recess 71) increases. Therefore, as in the second embodiment, the Z-direction dimension of the upper recess 71 is made smaller than the Z-direction dimension of the lower recess 72, thereby making it possible to reduce the inner diameter of the upper end opening of the upper recess 71. As a result, it is possible to improve the degree of freedom in design, to narrow the pitch of the pressure chambers 61, and to reduce the size of the head chip 50.

[0098] Third embodiment FIG. 27 is a cross-sectional view of head chip 50 according to the third embodiment, corresponding to FIG. In the head chip 50 shown in FIG. 27, the lower recess 72 is provided individually corresponding to the upper recess 71. Of the inner surface of the lower recess 72, both ends in the X direction are located outside the lower end opening edge of the upper recess 71 in the X direction. Specifically, the +X side inner surface (second inner surface portion) 72c of the inner surface of the lower recess 72 is located on the +X side with respect to the lower end opening edge of the upper recess 71. Of the inner surfaces of the lower recess 72, the -X side inner surface (second inner surface portion) 72d is located on the -X side with respect to the lower end opening edge of the upper recess 71. Note that the +X side inner surface 72c and the -X side inner surface 72b may be located outside at least the lower end opening edge of the inner surface of the upper recess 71. In this case, the +X side inner surface 72c and the -X side inner surface 72d may be located outside the upper end opening edge of the inner surface of the upper recess 71, for example. The opening area of ​​the lower end opening of the lower recess 72 may be larger or smaller than the opening area of ​​the upper end opening of the upper recess 71 .

[0099] In the head chip 50 of the third embodiment, the upper recess 71 and the lower recess 72 are formed to correspond to each other, making it easier to ensure stable conductivity compared to, for example, when adjacent second common through wirings 85 are formed in the same lower recess 72.

[0100] (Fourth embodiment) Fig. 28 is an enlarged cross-sectional view of head chip 50 according to the fourth embodiment, corresponding to Fig. 5. Fig. 29 is an enlarged cross-sectional view of head chip 50 according to the fourth embodiment, corresponding to Fig. 6. Fig. 30 is a plan view of cover plate 55 of head chip 50 according to the fourth embodiment, corresponding to Fig. 10. Fig. 31 is a cross-sectional view corresponding to Fig. 28 and is an explanatory diagram of head chip 50 according to the fourth embodiment. 31 , in the second cover processing step S04, when forming an electrode material in the conductive portion 55a, the electrode material may also be deposited on the inner surface facing the X direction among the inner surfaces of the upper recess 71 due to the influence of the relative positional accuracy between the deposition source and the cover plate 55, the processing accuracy of the upper recess 71, etc. In this case, the second common through wiring 85 and the second individual through wiring 86 may be connected on the inner surface facing the X direction among the inner surfaces of the upper recess 71.

[0101] Therefore, as shown in FIG. 28 to FIG. 30, the cover plate 55 has a separation processing portion 150 that separates the second common through wiring 85 and the second individual through wiring 86 in the conductive portion 55a. The separation processing portion 150 is formed in a groove shape extending in the X direction so as to straddle each through hole 73. The separation processing portion 150 is formed so that the dimension in the Y direction is smaller than that of the lower recess 72 and the dimension in the Z direction is larger than that of the upper recess 71. The separation processing portion 150 is formed so as to pass through the center of each through hole 73 in the Y direction. Therefore, the separation processing portion 150 opens on the inner surface of the upper recess 71 facing the X direction. As a result, the second common through wiring 85 and the second individual through wiring 86 are separated by the separation processing portion 150 on the inner surface of the upper recess 71 facing the X direction.

[0102] 31, the separation processing portion 150 is formed by performing dicing processing on the upper surface of the cover plate 55 using a dicer 151, for example. The dimension of the separation processing portion 150 in the Z direction may be equal to or smaller than the dimension of the upper recess 71. In other words, the dimension of the separation processing portion 150 in the Z direction can be appropriately adjusted according to the depth of the electrode material attached to the inner surface of the upper recess 71.

[0103] In the head chip 50 of the fourth embodiment, after the wiring material that becomes the second common through wiring 85 and the second individual through wiring 86 is formed in the through hole 73 at once, the second common through wiring 85 and the second individual through wiring 86 can be separated by post-processing. This makes it possible to improve manufacturing efficiency compared to the case where the formation areas of the second common through wiring 85 and the second individual through wiring 86 are controlled in advance by patterning or the like. Moreover, as in the head chip 50 of the fourth embodiment, by forming the separation processed portion 150 across the plurality of through holes 73, it is possible to collectively separate the second common through wiring 85 and the second individual through wiring 86 of each of the plurality of through holes 73. As a result, it is possible to further improve the manufacturing efficiency.

[0104] In the fourth embodiment, the configuration in which the separation processed portion 150 is formed so as to straddle the through holes 73 has been described, but the present invention is not limited to this configuration. The separation processed portion 150 may be formed only in the upper recess 71 where the second common through wiring 85 and the second individual through wiring 86 may be connected to each other. In the fourth embodiment, a configuration has been described in which the amount of penetration of the dicer 151 is within the range of the conductive portion 55a, but the present invention is not limited to this configuration. The dicer 151 may reach the actuator plate 54. This allows the separation processing unit 150 to separate wiring of different systems formed on the portion of the upper surface of the actuator plate 54 that is exposed through the conductive portion 55a.

[0105] In the fourth embodiment, the configuration in which the excess electrode material is removed by dicing has been described, but the present invention is not limited to this configuration. For example, the excess electrode material may be removed by laser irradiation. When the excess electrode material is removed by laser irradiation, the laser irradiation mark caused by the laser irradiation on the inner surface of the upper recess 71 becomes the separation processing part 150.

[0106] Fifth embodiment 32 and 33 are cross-sectional views of a head chip 200 according to the fifth embodiment. 32 and 33 includes a nozzle plate 201, an actuator plate 202, and a cover plate 203. The head chip 200 has a configuration in which the nozzle plate 201, the actuator plate 202, and the cover plate 203 are stacked in this order in the Z direction.

[0107] <Actuator plate 202> The actuator plate 202 is formed with a channel row 210. The channel row 210 has ejection channels 211 that are filled with ink, and non-ejection channels 212 that are not filled with ink. The channels 211, 212 are arranged alternately in the actuator plate 202 with an interval therebetween in the X direction.

[0108] 32, the discharge channel 211 is formed in the +Y side portion of the actuator plate 202. The discharge channel 211 is formed in a circular arc shape that protrudes downward when viewed from the X direction. The discharge channel 211 opens on the upper and lower surfaces of the actuator plate 202. The dimension of the discharge channel 211 in the Y direction becomes smaller as it goes downward.

[0109] 33, the non-ejection channels 212 extend linearly over the entire length of the actuator plate 202 in the Y direction, penetrating the actuator plate 202 in the Z direction. Portions of the actuator plate 202 located between adjacent ejection channels 211 and non-ejection channels 212 each constitute a driving wall 215.

[0110] <Cover plate 203> 32 and 33, the cover plate 203 is laminated by adhesion or the like on the upper surface of the actuator plate 202 so as to cover the upper end openings of the channels 211, 212. An inlet common flow path 220 is formed in the cover plate 203 at a position overlapping the -Y side end of the ejection channel 211 in a plan view. The inlet common flow path 220 extends in the X direction, for example, by a length spanning the channel row 210, and opens at the upper surface of the cover plate 203. In the inlet common flow channel 220, an inlet slit 221 is formed at a position overlapping with the discharge channel 211 in a plan view. The inlet slit 221 individually communicates between the -Y side end of each discharge channel 211 and the inside of the inlet common flow channel 220.

[0111] An outlet common flow channel 225 is formed in the cover plate 203 at a position overlapping in plan view with the +Y side end of the discharge channel 211. The outlet common flow channel 225 extends in the X direction, for example, by a length spanning the channel row 210, and opens at the upper surface of the cover plate 203. In the outlet common flow path 225, an outlet slit 226 is formed at a position overlapping with the non-ejection channel 212 in a plan view. The outlet slit 226 separately communicates between the +Y side end of each ejection channel 211 and the inside of the outlet common flow path 225. Therefore, the inlet slit 221 and the outlet slit 226 communicate with each ejection channel 211, but do not communicate with the non-ejection channel 212.

[0112] <Nozzle plate 201> The nozzle plate 201 is laminated on the lower surface of the actuator plate 202 by adhesion or the like. Nozzle holes 201a are formed in the nozzle plate 201 at positions overlapping with the centers of the ejection channels 211 in the Y direction. An intermediate plate (not shown) may be interposed between the nozzle plate 201 and the actuator plate 202. In this case, the ejection channels 211 and the nozzle holes 201a are communicated with each other through communication holes formed in the intermediate plate.

[0113] Next, a description will be given of the drive wiring (common wiring 230 and individual wiring 235) formed on the actuator plate 202. FIG. As shown in FIGS. 32 and 34, the common wiring 230 includes a common electrode 231 and a common lead wiring 232.

[0114] The common electrodes 231 are formed on at least the inner surfaces of the ejection channels 211 that face each other in the X direction. The common outgoing wiring 232 is formed on the upper surface of a portion (hereinafter referred to as tail portion 202a) of the actuator plate 202 located on the -Y side with respect to the ejection channel 211. The common outgoing wiring 232 is provided on the upper surface of the tail portion 202a in correspondence with each ejection channel 211. Each common outgoing wiring 232 extends linearly in the Y direction with respect to the corresponding ejection channel 211. The +Y side end of the common pad 255 is connected to the common electrode 231 at the upper opening edge of the ejection channel 211.

[0115] As shown in FIGS. 33 and 34, the individual wiring 235 includes an individual electrode 236 and an individual lead-out wiring 237. The individual electrodes 236 are formed on the inner surfaces of the non-ejection channels 212 that face each other in the X direction. The individual lead-out wiring 237 is formed on the upper surface of the tail portion 202a in a portion located on the -Y side of the common lead-out wiring 232. The individual lead-out wiring 237 is in a belt shape extending in the X direction. The individual lead-out wiring 237 connects the individual electrodes 236 that face each other in the X direction with the ejection channel 211 therebetween at the upper opening edges of the non-ejection channels 212 that face each other in the X direction with the ejection channel 211 therebetween.

[0116] FIG. 35 is a plan view of the cover plate 203. 32 and 35, a conductive portion 260 is formed in the cover plate 203. The conductive portion 260 includes an upper recess 261 and a lower recess 262. The upper recess 261 is formed in a tapered shape in which the inner diameter in at least the Y direction gradually decreases from the top to the bottom in a cross-sectional view.

[0117] The lower recess 262 is formed in a groove shape extending in the X direction so as to span all of the upper recesses 261. The lower recess 262 communicates with the inside of the upper recess 261 through a portion that overlaps with the upper recess 261 in a plan view. In the conductive portion 260, a portion where the upper recess 261 and the lower recess 262 communicate with each other constitutes a through hole 263 that penetrates the cover plate 203 in the Z direction.

[0118] Of a pair of inner surfaces facing each other in the Y direction in the lower recess 262, the +Y side inner surface (first inner surface portion) 262a is connected without a step from the same position in a plan view as the +Y side opening edge of the lower end opening edge of the upper recess 261. Therefore, the +Y side inner surface 262a is located within the dimensional range of the lower end opening of the upper recess 261 as viewed in the Z direction, and extends continuously to the inner surface of the upper recess 261. Of the pair of inner surfaces of the lower recess 262 facing each other in the Y direction, the -Y side inner surface (first inner surface portion) 262b is connected without a step from the same position as the -Y side opening edge of the lower end opening edge of the upper recess 261 in a plan view. Therefore, the +Y side inner surface 262a is located within the dimensional range of the lower end opening of the upper recess 261 as seen from the Z direction, and extends continuously to the inner surface of the upper recess 261. The +X side end of the lower recess 262 is located on the +X side with respect to the upper recess 261 located closest to the +X side among the upper recesses 261. The -X side end of the lower recess 262 is located on the -X side with respect to the upper recess 261 located closest to the -X side among the upper recesses 261.

[0119] The cover plate 203 is formed with a common through wire 251 and an individual through wire 252 as connection wires, and a common pad 255 and an individual pad 256 as terminal wires.

[0120] As shown in FIG. 32, the common through wiring 251 is formed over the entire length in the Z direction in a portion located on the +Y side of the inner surface of the through hole 263. Specifically, the upper half of the common through wiring 251 is formed in at least a portion located on the +Y side of the inner surface of the upper recess 261. The upper edge of the common through wiring 251 is located at the upper opening edge of the upper recess 261 (through hole 263). The lower half of the common through wiring 251 is formed on the +Y side inner surface 262a of the inner surface of the lower recess 262. The upper and lower halves of the common through wiring 251 are connected at the boundary between the upper recess 261 and the lower recess 262. The lower edge of the common through wiring 251 is located at the lower opening edge of the lower recess 262 (through hole 263). The lower edge of the common through wiring 251 is connected to the common lead wiring 232 on the upper surface of the tail portion 202a.

[0121] As shown in FIGS. 32 and 35, the common pad 255 extends on the upper surface of the cover plate 203 from the upper opening edge of the through hole 263 toward the +Y side.

[0122] As shown in FIG. 32, the individual through wiring 252 is formed over the entire length in the Z direction in a portion located on the -Y side of the inner surface of the through hole 263. Specifically, the upper half of the individual through wiring 252 is formed in at least a portion located on the -Y side of the inner surface of the upper recess 261. The upper end edge of the individual through wiring 252 is located at the upper end opening edge of the upper recess 261 (through hole 263). The lower half of the individual through wiring 252 is formed on the -Y side inner surface 262b of the inner surface of the lower recess 262. The upper and lower halves of the individual through wiring 252 are connected at the boundary portion between the upper recess 261 and the lower recess 262. The lower end edge of the individual through wiring 252 is located at the lower end opening edge of the lower recess 262 (through hole 263). The lower end edge of the individual through wiring 252 is connected to the individual lead wiring 237 on the upper surface of the tail portion 202a.

[0123] The common through wiring 251 and the individual through wiring 252 are separated from each other by the through hole 263. Specifically, the common through wiring 251 and the individual through wiring 252 are not formed on the inner surface of the upper recess 261 facing the X direction. Therefore, the upper halves of the common through wiring 251 and the individual through wiring 252 are separated from each other by the inner surface of the upper recess 261 facing the X direction. On the other hand, the lower recess 262 extends outward in the X direction with respect to the lower end opening edge of one of the upper recesses 261. Therefore, the lower halves of the common through wiring 251 and the individual through wiring 252 are separated from each other by the lower recess 262. Note that in order to separate the common through wiring 251 and the individual through wiring 252, a separating groove or the like may be formed in the through hole 263.

[0124] As shown in FIGS. 32 and 35, the individual pads 256 extend from the upper opening edge of the through-holes 263 on the upper surface of the cover plate 203 to the −Y side.

[0125] In the head chip 200 of the fifth embodiment, ejection channels (ejection channels) 211 and non-ejection channels (non-ejection channels) 212 are formed in the actuator plate 202, and common lead-out wiring 232 and individual lead-out wiring 237 are formed on the upper surface of the actuator plate 202. According to this configuration, the common electrode 231 formed on the inner surface of the ejection channel 211 can be easily routed to the common through-wire 251 , and the individual electrodes 236 formed on the inner surface of the non-ejection channel 212 can be easily routed to the individual through-wire 252 . Moreover, compared to a configuration in which a flexible printed circuit board is pressure-bonded to actuator plate 202, the thickness of the portion of head chip 200 to which the flexible printed circuit board is pressure-bonded can be ensured. Therefore, the work of pressure-bonding the flexible printed circuit board becomes easier, and manufacturing efficiency and yield can be improved.

[0126] In the above-mentioned fifth embodiment, the side shoot head chip 200 has been described as an example, but the present disclosure is not limited to this configuration. For example, as shown in Fig. 36, the configuration according to the present disclosure may be adopted in a so-called edge shoot type head chip 200 that ejects ink from the end of the ejection channel 211 in the extension direction (Y direction).

[0127] (Other variations) The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. For example, in the above embodiment, the inkjet printer 1 has been described as an example of a liquid jet recording apparatus, but the liquid jet recording apparatus is not limited to a printer. For example, the liquid jet recording apparatus may be a fax machine, an on-demand printer, or the like. In the above-described embodiment, a configuration in which the inkjet head moves relative to the recording medium during printing (so-called shuttle machine) has been described as an example, but the present disclosure is not limited to this configuration. The configuration according to the present disclosure may be adopted in a configuration in which the recording medium moves relative to the inkjet head while the inkjet head is fixed (so-called fixed head machine). In the above embodiment, the recording medium P is paper, but this is not limited to the above configuration. The recording medium P is not limited to paper, and may be a metal material, a resin material, or a food product. In the above-described embodiment, the liquid ejection head is mounted on the liquid ejection recording device, but the present invention is not limited to this configuration. In other words, the liquid ejected from the liquid ejection head is not limited to the liquid that is to be landed on the recording medium, and may be, for example, a medicinal liquid to be mixed in a medicine, a food additive such as a seasoning or a fragrance to be added to food, or an aromatic to be sprayed into the air.

[0128] In the above embodiment, the configuration has been described in which the Z direction coincides with the direction of gravity, but the present invention is not limited to this configuration, and the Z direction may be aligned with the horizontal direction. In the above embodiment, the upper recess is formed by sandblasting and the lower recess is formed by dicing, but the present invention is not limited to this configuration. The upper recess and the lower recess may be formed by a method appropriately selected from various processing methods such as sandblasting, dicing, and etching.

[0129] In each of the above-described embodiments, the through hole is formed by the communicating portion between the upper recess and the lower recess, but the present invention is not limited to this configuration. The through hole may be formed so as to penetrate the cover plate in the thickness direction.

[0130] In the above-described embodiment, a configuration in which a part of the inner surface of the lower recess is disposed at the same position as the lower end opening edge of the upper recess has been described, but the present invention is not limited to this configuration. For example, as in the conductive portion 410 shown in FIG 37, a part of the inner surface of the lower recess 411 (first inner surface portion) may be located inside the lower end opening edge of the upper recess 412 (second inner surface portion).

[0131] In the above-described first embodiment, a configuration has been described in which two grooves 69 are formed in each of the portions overlapping with each partition wall 62 in a plan view in order to provide a groove 69 corresponding to each pressure chamber 61, but the configuration is not limited to this. As shown in Fig. 38, one groove 69 may be provided in each of the portions overlapping with each partition wall 62 in a plan view so that the groove 69 can be shared between adjacent pressure chambers 61. In this case, the groove 69 can thereby narrow the pitch of the pressure chambers 61 (improving nozzle density) and improve actuator performance.

[0132] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0133] 1: Printer (liquid jet recording device) 5: Inkjet head (liquid ejection head) 50: Head chip 54: Actuator plate 61: Pressure chamber 71: Upper recess (first recess) 72: Lower recess (second recess) 72a: +Y side inner surface (first inner surface part) 72b: -Y side inner surface (first inner surface part) 72c: +X side inner surface (second inner surface part) 72d: -X side inner surface (second inner surface part) 81a: 1st common electrode (common electrode) 81b: Second common electrode (common electrode) 81c: Third common electrode (common electrode) 82a: Individual electrode 85: Second common through-hole wiring (common through-hole wiring) 86: Second individual through wiring (individual through wiring) 87: Common pad 88: Individual pad 150: Separation processing section 200: Head chip 202: Actuator plate 203: Cover plate 203 231: Common electrode 236: Individual electrode 251: Common through-hole wiring 255: Common pad 256: Individual through-wiring 257: Individual pad 261: Upper recess (first recess) 262: Lower recess (second recess) 262a: +Y side inner surface (first inner surface part) 262b: -Y side inner surface (first inner surface part) 262c: +X side inner surface (second inner surface part) 262d: -X side inner surface (second inner surface part)

Claims

1. an actuator plate that is deformable so that a pressure chamber in which liquid is contained expands or contracts; a common electrode and an individual electrode formed on the actuator plate to generate an electric field in the actuator plate; a cover plate superimposed on a first surface of the actuator plate facing a first side in a thickness direction, The cover plate is formed with a through hole penetrating the cover plate in the thickness direction, A head chip in which a common through-hole connecting an external wiring provided on a first side in the thickness direction of the cover plate and the common electrode, and an individual through-hole connecting the external wiring and the individual electrode are formed in a mutually separated state within the through-hole.

2. The cover plate includes: a first recess that opens onto a first surface facing a first side in the thickness direction; a second recess that opens onto a second surface facing a second side that is opposite to the first side in the thickness direction; the through hole is formed by a portion of the first recess and a portion of the second recess that are in communication with each other, The second recess is a first inner surface portion located at the same position as an inner surface of the first recess as viewed in the thickness direction, or located inside the inner surface of the first recess as viewed in the thickness direction; a second inner surface portion located at a position different from the first inner surface portion as viewed in the thickness direction and on an outer side of the inner surface of the first recess as viewed in the thickness direction, The head chip according to claim 1 , wherein the common through wire and the individual through wire penetrate the cover plate via the first inner surface portion and the inner surface of the first recess.

3. The first recesses are provided in a plurality of spaces in a first direction intersecting the thickness direction, The second recess extends in the first direction so as to straddle at least two adjacent first recesses among the plurality of first recesses, the first inner surface portion is located at the same position as or inside the inner surface of the first recess in a second direction intersecting the first direction as viewed from the thickness direction, among the inner surfaces of the second recess, The head chip according to claim 2 , wherein the second inner surface portion is located on an inner surface of the second recess outside the inner surface of the first recess in the first direction.

4. The first recess is formed in a tapered shape in which an inner diameter decreases toward a second side in the thickness direction, 4. The head chip according to claim 2, wherein a dimension of the first recess in the thickness direction is larger than a dimension of the second recess in the thickness direction.

5. The first recess is formed in a tapered shape such that an inner diameter gradually decreases toward the second side in the thickness direction, 4. The head chip according to claim 2, wherein a dimension of the first recess in the thickness direction is smaller than a dimension of the second recess in the thickness direction.

6. a common pad connected to the common through wiring at an opening edge of the through hole and an individual pad connected to the individual through wiring at an opening edge of the through hole are formed on a first surface of the cover plate facing a first side in the thickness direction; 4. The head chip according to claim 1, wherein the common pad and the individual pads extend in directions away from each other from the through hole on the first surface of the cover plate.

7. 4. The head chip according to claim 1, wherein the cover plate is formed with a separation processed portion that separates the common through wire and the individual through wire within the through hole.

8. The through holes are provided at intervals in a first direction intersecting the thickness direction, The head chip according to claim 7 , wherein the separation processed portion extends in the first direction in a groove shape so as to straddle at least two adjacent through holes among the plurality of through holes.

9. A liquid-jet head comprising the head chip according to claim 1 .

10. A liquid jet recording apparatus comprising the liquid jet head according to claim 9.

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