Head chip, liquid jet head, liquid jet recording device and method for manufacturing head chip

Abstract

To provide a head chip, a liquid jet head, a liquid jet recording device and a method for manufacturing the head chip, which improve manufacturing efficiency and reduce a cost, and can protect an electrode.SOLUTION: A head chip includes: a flow channel member in which a plurality of pressure chambers storing liquid is formed so as to be aligned side by side in a first direction; an actuator plate which is arranged on the flow channel member in a state of facing the pressure chambers in a second direction crossing the first direction; pieces of driving wiring which are formed on flow channel opposite surfaces facing the flow channel members, in a driving part overlapping the pressure chambers when being viewed from the second direction, in the actuator plate; and a sheet-like protective film which has a first coating part coating the pieces of driving wiring on the flow channel opposite surfaces, and partitions the pressure chambers and the driving part.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] An 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 superposed on the actuator plate. In the actuator plate, electrodes are formed on the inner surfaces of the ejection channels. For example, Patent Document 1 below discloses a configuration in which electrodes are protected by a deposited film made of an insulating material such as a parylene-based resin material (e.g., parylene (registered trademark)).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described conventional technology, since the deposited film is formed by a film-forming method such as chemical vapor deposition (CVD), when film-forming defects (e.g., pinholes, etc.) occur, discontinuous portions are formed in the deposited film. In this case, ink may enter between the deposited film and the inner surface of the ejection channel through the discontinuous portion, which may cause short circuits or corrosion of the electrodes. In order to reduce the risk of film-forming defects, ensuring the thickness of the deposited film or strictly managing the film-forming state is required, which leads to a decrease in manufacturing efficiency and an increase in material costs.

[0005] The present disclosure provides a head chip, a liquid ejection head, a liquid ejection recording apparatus, and a method for manufacturing a head chip that can protect electrodes while improving manufacturing efficiency and reducing costs.

Means for Solving the Problems

[0006] In order to solve the above problems, the present disclosure has adopted the following aspects. (1) A head chip according to an aspect of the present disclosure includes a flow path member in which a plurality of pressure chambers for accommodating liquid are formed side by side in a first direction, an actuator plate disposed on the flow path member in a state facing in a second direction intersecting the first direction with respect to the pressure chamber, drive wirings respectively formed on flow path facing surfaces facing the flow path member in drive portions of the actuator plate that overlap the pressure chamber when viewed from the second direction, and a first covering portion covering the drive wirings on the flow path facing surfaces, and a sheet-like protective film partitioning between the pressure chamber and the drive portion.

[0007] According to this aspect, by partitioning between the pressure chamber and the drive portion with a sheet-like protective film, unlike a configuration in which a deposition film made of a parylene-based resin material or the like is formed by a film formation method such as CVD as in the prior art, it is possible to suppress the occurrence of discontinuous portions such as pinholes. That is, by partitioning between the pressure chamber and the drive portion with a continuously formed sheet-like protective film, it is possible to suppress liquid from reaching the drive wirings formed in the drive portion. Thereby, short circuits and corrosion of the drive wirings can be suppressed, and a head chip with excellent reliability can be provided. Further, by adopting a sheet-like protective film, a simple and low-cost protective film can be provided as compared with a configuration in which a deposition film is formed by a film formation method such as CVD. As a result, the manufacturing efficiency of the head chip can be improved, and the cost of the head chip can be reduced.

[0008] (2) In the head chip according to the aspect of (1) above, it is preferable that the protective film includes a protruding portion protruding outward in an intersecting direction intersecting the second direction when viewed from the second direction with respect to the flow path member and the actuator plate. According to this aspect, since the protective film is provided with the protruding portion, when the protective film is provided with respect to the flow path facing surface (drive portion), the protruding portion can be used as a gripping margin in the protective film forming process and as a margin for absorbing the positional deviation between the actuator plate and the protective film in a direction intersecting the second direction. Thereby, the manufacturing efficiency of the head chip can be improved.

[0009] (3) In the head chip according to the aspect of (2) above, it is preferable that the protruding portion covers a side surface of the actuator plate facing the intersecting direction. According to this aspect, the boundary portion between the first covering portion and the actuator plate is covered by the protruding portion. The entry of liquid from the outside of the head chip can be suppressed with respect to the interface between the flow path facing surface of the actuator plate and the protective film (first covering portion). Thereby, the reliability of the head chip can be improved.

[0010] (4) In the head chip according to the aspect of (3) above, it is preferable that the protruding portion extends along the first direction in a portion of the side surface facing a third direction that intersects the first direction among the intersecting directions. According to this aspect, the protruding portion will be arranged along the arrangement direction of the pressure chambers on the side surface of the actuator plate. Thereby, even if liquid enters the interface between the flow path member and the protective film, it is possible to suppress the liquid from bridging between drive wirings corresponding to different pressure chambers.

[0011] (5) In the head chip according to any one of the aspects (1) to (4) above, it is preferable that the protective film is continuously provided over the entire area of the flow path facing surface. According to this aspect, since the entire area of the flow path facing surface is covered with the protective film, it is possible to surely suppress the liquid from reaching the drive wiring.

[0012] (6) In the head chip according to the aspect (5) above, a recess that is recessed in a direction away from the flow path member in the second direction is formed in the drive unit, the drive wiring is formed on the inner surface of the recess, and the first covering portion is preferably provided along the inner surface of the recess so as to cover the drive wiring. According to this aspect, by forming the drive wiring on the inner surface of the recess, the surface area of the drive wiring can be ensured. As a result, the electric field generated in the actuator plate can be increased, and the pressure generated in the pressure chamber during liquid injection can be improved. Moreover, by forming a recess in the actuator plate, the rigidity of the actuator plate in the second direction can be increased.

[0013] (7) In the head chip according to any one of the aspects (1) to (4) above, an injection hole plate having injection holes communicating with the pressure chamber is provided on the side opposite to the actuator plate in the second direction with respect to the flow path member, and the protective film is continuous with the first covering portion and includes a second covering portion that covers a portion of the flow path member facing the pressure chamber, and a third covering portion that is continuous with the second covering portion and covers a surface of the flow path member facing the injection hole plate in the second direction, which is preferable. According to this aspect, since the interface between the actuator plate and the flow path member is covered by the second covering portion, the entry of liquid into the interface between the actuator plate and the flow path member can be suppressed. Moreover, since the surface of the flow path member facing the injection hole plate is covered by the third covering portion, even if the third covering portion is damaged and liquid enters the interface between the flow path member and the protective film, it is possible to suppress the liquid from reaching the interface between the actuator plate and the flow path member and suppress the peeling between the actuator plate and the flow path member. Further, since the distance to the interface between the protective film and the flow path member is separated by the thickness of the protective film, even if the second covering portion is damaged, it is possible to suppress the liquid from reaching the interface between the actuator plate and the flow path member and suppress the peeling between the actuator plate and the flow path member.

[0014] (8) In the head chip according to any one of the aspects (1) to (4) above, on the side opposite to the actuator plate in the second direction with respect to the flow path member, an injection hole plate having injection holes communicating with the pressure chamber is provided, and the protective film includes a first protective portion continuously provided over the entire area of the flow path facing surface, a second covering portion that is continuous with the first covering portion and covers the portion of the flow path member facing the pressure chamber, and a third covering portion that is continuous with the second covering portion and covers the surface of the flow path member facing the injection hole plate in the second direction. It is preferable to include a second protective portion that is superposed on the first protective portion on the drive portion. According to this aspect, since the entire area of the flow path facing surface is covered by the first protective portion, it is possible to reliably prevent the liquid from reaching the drive wiring. Further, since the interface between the actuator plate and the flow path member is covered by the second protective portion, it is possible to suppress the entry of the liquid into the interface between the actuator plate and the flow path member. Thereby, peeling between the actuator plate and the flow path member can be suppressed.

[0015] (9) In the head chip according to any one of the aspects (1) to (8) above, it is preferable that the softening point of the protective film is set to 120 °C or lower. According to this aspect, in the protective film forming step, when the protective film is brought into close contact with the drive portion while heating the protective film, it is possible to suppress the occurrence of polarization breakdown (for example, about 130 °C) of the actuator plate. Thereby, a head chip with excellent reliability can be provided.

[0016] (10) In the head chip according to any one of the aspects (1) to (9) above, it is preferable that the protective film is formed of a thermoplastic resin. According to this aspect, in the protective film forming step, by heating the protective film, the protective film is easily deformed. Thereby, the protective film is easily brought into close contact with the drive portion.

[0017] (11) It is preferable that the liquid injection head according to one aspect of the present disclosure includes the head chip according to any one of the aspects (1) to (10) above. According to this aspect, since the head chip according to the above aspect is provided, a liquid ejection head with excellent reliability can be provided.

[0018] (12) The liquid ejection recording apparatus according to one aspect of the present disclosure preferably includes the liquid ejection head according to the above aspect (11). According to this aspect, since the head chip according to the above aspect is provided, a liquid ejection recording apparatus with excellent reliability can be provided.

[0019] (13) A method for manufacturing a head chip according to one aspect of the present disclosure includes a flow path member in which a plurality of pressure chambers for storing liquid are formed side by side in a first direction, an actuator plate disposed on the flow path member in a state facing the pressure chambers in a second direction intersecting the first direction, and the second direction being a polarization direction, and drive wirings respectively formed on a flow path facing surface facing the flow path member in a drive portion of the actuator plate that overlaps the pressure chamber when viewed from the second direction, and a sheet-like protective film that covers the drive wirings on the flow path facing surface of the drive portion and partitions between the pressure chamber and the drive portion. The method for manufacturing a head chip includes a protective film forming step of covering the drive portion with the protective film by closely adhering the protective film to the drive portion.

[0020] (14) In the method for manufacturing a head chip according to the above aspect (13), in the protective film forming step, in a chamber in which the actuator plate and the protective film are set, a first space located on the actuator plate side with respect to the protective film is set to a negative pressure with respect to a second space located on the side opposite to the actuator plate with respect to the protective film, so that it is preferable to closely adhere the protective film to the drive portion. According to this aspect, by generating a pressure difference between the first space and the second space, it is easy to quickly adhere the protective film to the drive portion.

Effects of the Invention

[0021] According to one aspect of the present disclosure, it is possible to protect the drive wiring while improving manufacturing efficiency and reducing costs.

Brief Description of the Drawings

[0022]

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Figure 22

Mode for Carrying Out the Invention

[0023] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. In the embodiments and modifications described below, corresponding components may be denoted by the same reference numerals and the description thereof may be omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel", "orthogonal", "center", "coaxial", etc. not only strictly represent such arrangements, but also represent states in which they are relatively displaced with tolerances and angles and distances that can obtain the same function. In the following embodiments, an inkjet printer (hereinafter simply referred to as a printer) that performs recording on a recording medium using ink (liquid) will be described as an example. In the drawings used in the following description, the scales of the respective members are appropriately changed in order to make the respective members recognizable in size.

[0024] (First Embodiment) [Printer 1] FIG. 1 is a schematic configuration diagram of printer 1. The 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 7.

[0025] In the following description, the orthogonal coordinate system of X, Y, and Z will be used for explanation as necessary. In this case, the X direction coincides with the conveyance direction (sub-scanning direction) of the recording medium P (for example, paper or the like). 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) orthogonal to the X direction and the Y direction. In the following description, among the X direction, Y direction, and Z direction, the side of the arrow in the figure is defined as the plus (+) side, and the side opposite to the arrow is defined as the minus (-) side. In this specification, the +Z side corresponds to the upper side in the gravity direction, and the -Z side corresponds to the lower side in the gravity direction.

[0026] The conveyance mechanisms 2 and 3 convey the recording medium P to the +X side. The conveyance mechanisms 2 and 3 each include, for example, a pair of rollers 11 and 12 extending in the Y direction. The ink tank 4 stores, for example, four colors of ink: yellow, magenta, cyan, and black separately. Each inkjet head 5 is configured to be able to eject the four colors of ink: yellow, magenta, cyan, and black, respectively, according to the connected ink tank 4.

[0027] Figure 2 is a schematic configuration diagram of the inkjet head 5 and the ink circulation mechanism 6. As shown in FIGS. 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.

[0028] The pressure pump 24 pressurizes the inside of the ink supply pipe 21 and sends the ink through the ink supply pipe 21 to the inkjet head 5. As a result, the ink supply pipe 21 side is at a positive pressure with respect to the inkjet head 5. The suction pump 25 reduces the pressure inside the ink discharge pipe 22 and sucks ink from the inkjet head 5 through the ink discharge pipe 22. As a result, the side of the ink discharge pipe 22 with respect to the inkjet head 5 is at a negative pressure. The ink can circulate between the inkjet head 5 and the ink tank 4 through the circulation channel 23 by driving the pressure pump 24 and the suction pump 25.

[0029] As shown in FIG. 1, the scanning mechanism 7 reciprocally scans the inkjet head 5 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.

[0030] <inkjet head 5> The inkjet head 5 is mounted on the 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 (see FIG. 3), an ink supply section (not shown) connecting between the ink circulation mechanism 6 and the head chip 50, and a control section (not shown) applying a drive voltage to the head chip 50.

[0031] <head chip 50> FIG. 3 is an exploded perspective view of the head chip 50. FIG. 4 is a cross-sectional view of the head chip 50 corresponding to the line IV-IV in FIG. 3. FIG. 5 is a cross-sectional view of the head chip 50 corresponding to the line V-V in FIG. 4. The head chip 50 shown in FIGS. 3 to 5 is a so-called circulating side-shoot type head chip that circulates ink with the ink tank 4 and discharges ink from the central portion in the extending direction (Y direction) in the pressure chamber 61 described later. The head chip 50 includes a nozzle plate 51, a flow path member 52, a first protective film 53, an actuator plate 54, a film 55, and a cover plate 56. In the following description, among the Z directions, the direction from the nozzle plate 51 toward the cover plate 56 (+Z side) is defined as the front side, and the direction from the cover plate 56 toward the nozzle plate 51 (−Z side) is defined as the back side for explanation.

[0032] The flow path member 52 is plate-shaped with the Z direction as the thickness direction. The flow path member 52 is formed of a material having ink resistance. As such a material, for example, metal, metal oxide, glass, resin, ceramics, etc. can be adopted. In the flow path member 52, a flow path 60 through which ink flows and a plurality of pressure chambers 61 that communicate with the flow path 60 and in which ink is stored are formed. The flow path 60 and the pressure chambers 61 penetrate the flow path member 52 in the Z direction.

[0033] FIG. 6 is a plan view of the flow path member 52. As shown in FIG. 6, the pressure chambers 61 are arranged at intervals in the X direction. Therefore, in the flow path member 52, the portion located between adjacent pressure chambers 61 constitutes a partition wall 62 that partitions between 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. In the first embodiment, a configuration in which the channel extending direction coincides with the Y direction will be described, but the channel extending direction may intersect the Y direction. Further, the planar shape of the pressure chamber 61 is not limited to a rectangular shape (a shape having one of the X direction and the Y direction as the longitudinal direction and the other as 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.

[0034] The flow path 60 includes an inlet-side common flow path 64, an inlet-side connection flow path 65, an outlet-side common flow path 66, an outlet-side connection flow path 67, and a bypass path 68. The inlet-side common flow path 64 extends in the X direction in 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 portion in 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 pipe 21 (see FIG. 2). That is, the ink flowing in the ink supply pipe 21 is supplied to the inlet-side common flow path 64 through the inlet port. The inlet-side connection flow path 65 connects between the inlet-side common flow path 64 and each pressure chamber 61. Specifically, each inlet-side connection flow path 65 branches from a portion of the inlet-side common flow path 64 that overlaps with each pressure chamber 61 when viewed in the Y direction, toward the -Y side. The -Y side end portion in the inlet-side connection flow path 65 is connected to the pressure chamber 61.

[0035] The outlet-side common flow path 66 extends in the X direction in 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 portion in 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 pipe 22 (see FIG. 2). That is, the ink flowing in the outlet-side common flow path 66 is supplied to the ink discharge pipe 22 through the outlet port. The outlet-side connection flow path 67 connects between the outlet-side common flow path 66 and each pressure chamber 61. Specifically, each outlet-side connection flow path 67 branches from a portion of the outlet-side common flow path 66 that overlaps with each pressure chamber 61 when viewed in the Y direction, toward the +Y side. The +Y side end portion in the outlet-side connection flow path 67 is connected to the pressure chamber 61.

[0036] As shown in FIGS. 4 and 5, the nozzle plate 51 is fixed to the back surface of the flow path member 52 by adhesion or the like. The nozzle plate 51 has an outer shape in plan view equivalent to that of the flow path member 52. Therefore, the nozzle plate 51 closes the -Z side openings of the flow path 60 and the pressure chamber 61. In the first embodiment, the nozzle plate 51 is formed of a resin material such as polyimide to a thickness of about several tens to one hundred and several tens of μm. However, the nozzle plate 51 may have a single-layer structure or a laminated structure made of a metal material (such as SUS or Ni-Pd), glass, silicon, etc., in addition to the resin material.

[0037] A plurality of nozzle holes 71 penetrating the nozzle plate 51 in the Z direction are formed in the nozzle plate 51. The nozzle holes 71 are arranged at intervals in the X direction. Each nozzle hole 71 communicates with the corresponding pressure chamber 61 at the central portions in the X and Y directions. In the first embodiment, each nozzle hole 71 is formed in a tapered shape such that the inner diameter gradually decreases from the +Z side toward the -Z side, for example. In the first embodiment, the configuration in which the plurality of pressure chambers 61 and the plurality of nozzle holes 71 are arranged in a line in the X direction has been described, but the configuration is not limited thereto. When a plurality of pressure chambers 61 and a plurality of nozzle holes 71 arranged in the X direction are defined as a nozzle row, a plurality of nozzle rows may be provided at intervals in the Y direction. In this case, when the number of nozzle rows is n, it is preferable that the arrangement pitch of the nozzle holes 71 (pressure chambers 61) in the Y direction in one nozzle row is shifted by 1 / n pitch for each arrangement pitch of the nozzle holes 71 in another nozzle row adjacent to the one nozzle row.

[0038] The first protective film 53 is interposed between the flow path member 52 and the actuator plate 54. Details of the first protective film 53 will be described later.

[0039] The actuator plate 54 is provided on the first protective film 53 with the Z direction being the thickness direction. The outer shape of the actuator plate 54 in plan view is equivalent to the outer shape of the flow path member 52 in plan view. The actuator plate 54 is overlapped with the entire flow path member 52 with the first protective film 53 interposed therebetween. Therefore, the actuator plate 54 faces each pressure chamber 61 in the Z direction with the first protective film 53 interposed therebetween. Among the actuator plate 54, the portion overlapping with the pressure chamber 61 in plan view constitutes the drive portion 54a. Note that the actuator plate 54 (drive portion 54a) is not limited to a configuration that collectively covers each pressure chamber 61, and may be provided individually for each pressure chamber 61.

[0040] The actuator plate 54 is formed of a piezoelectric material such as PZT (lead zirconate titanate). The polarization direction of the actuator plate 54 is set to face the +Z side. Drive wirings 75 are formed on both surfaces of the actuator plate 54. The actuator plate 54 is configured to be deformable in the Z direction by generating an electric field due to the voltage applied by the drive wirings 75. The actuator plate 54 discharges ink from the pressure chamber 61 by expanding or contracting the volume in the pressure chamber 61 due to the deformation in the Z direction. Note that the configuration of the drive wirings 75 will be described later. Also, the polarization direction of the actuator plate 54 may face the -Z side.

[0041] The film 55 is fixed to the surface of the actuator plate 54 by adhesion or the like. In the first embodiment, the film 55 covers the entire surface area of the actuator plate 54. The film 55 has insulating properties and is formed of an elastically deformable material. Such a material is formed of, for example, a resin material (such as a polyimide-based, epoxy-based, or polypropylene-based material). In the first embodiment, "elastically deformable" means a member having a smaller compressive elastic modulus than the members adjacent in the Z direction in a state where a plurality of members are laminated. That is, the film 55 has a smaller compressive elastic modulus than the flow path member 52 and the actuator plate 54. Note that the film 55 is not an essential configuration.

[0042] The cover plate 56 is fixed to the surface of the film 55 by adhesion or the like with the Z direction being the thickness direction. The thickness of the cover plate 56 in the Z direction is thicker than that of the actuator plate 54, the flow path member 52, the first protective film 53, and the film 55. In the first embodiment, the cover plate 56 is formed of a material having insulating properties (for example, metal oxide, glass, resin, ceramics, etc.). Note that the cover plate 56, the film 55, and the actuator plate 54 constitute the laminate 100.

[0043] Next, the structure of the drive wiring 75 will be described. FIG. 7 is a bottom view of the actuator plate 54. FIG. 8 is a plan view of the actuator plate 54. The drive wiring 75 is provided corresponding to each pressure chamber 61. The drive wirings 75 corresponding to adjacent pressure chambers 61 are formed symmetrically with respect to the symmetry axis T along the Y direction. In the following description, the drive wiring 75 provided corresponding to one of the plurality of pressure chambers 61 will be described as an example, and the description of the drive wirings 75 corresponding to the other pressure chambers 61 will be omitted as appropriate. As shown in FIGS. 7 and 8, the drive wiring 75 includes a common wiring 81 and individual wirings 82. The common wiring 81 includes a first common electrode 81a, a second common electrode 81b, a back surface routing wiring 81c, a front surface routing wiring 81d, a first through wiring 81e, a second through wiring 81f, and a common pad 81g.

[0044] As shown in FIGS. 4 and 7, the first common electrodes 81a are respectively formed at positions overlapping with the respective partition walls 62 when viewed in the Z direction on the back surface (flow path facing surface) of the actuator plate 54. Specifically, the entire first common electrode 81a located on the +X side among the first common electrodes 81a (hereinafter referred to as the +X side common electrode 81a1) overlaps with the partition wall 62 located on the +X side (hereinafter referred to as the partition wall 62a) among the partition walls 62 partitioning the pressure chamber 61 when viewed in the Z direction. On the other hand, the entire first common electrode 81a located on the -X side among the first common electrodes 81a (hereinafter referred to as the -X side common electrode 81a2) overlaps with the partition wall 62 located on the -X side (hereinafter referred to as the partition wall 62b) among the partition walls 62 partitioning the pressure chamber 61 when viewed in the Z direction. Each first common electrode 81a extends linearly in the Y direction with the same length as the pressure chamber 61.

[0045] As shown in FIGS. 4 and 8, the second common electrode 81b is disposed on the surface of the actuator plate 54 at a position overlapping with the corresponding pressure chamber 61 when viewed in the Z direction and not overlapping with the first common electrode 81a when viewed in the Z direction. In the illustrated example, the second common electrode 81b is formed at the central portion in the X direction in the pressure chamber 61. The second common electrode 81b extends linearly in the Y direction with the same length as the pressure chamber 61. Note that the second common electrode 81b can be appropriately changed in terms of the width in the X direction and the like as long as it is formed at a position overlapping with the pressure chamber 61 when viewed in the Z direction.

[0046] As shown in FIGS. 4 and 7, the back surface routing wiring 81c is collectively connected to each first common electrode 81a on the back surface of the actuator plate 54. The back surface routing wiring 81c extends in the X direction while being connected to the -Y side end portions of the respective first common electrodes 81a.

[0047] As shown in FIGS. 4 and 8, the surface routing wiring 81d is connected to the second common electrode 81b on the surface of the actuator plate 54. The surface routing wiring 81d extends in the X direction from the -Y side end portion of the second common electrode 81b.

[0048] As shown in FIGS. 4, 7, and 8, the first through-wiring 81e connects the back-surface routing wiring 81c and the front-surface routing wiring 81d. The first through-wiring 81e is provided so as to penetrate the actuator plate 54 in the Z direction. Specifically, a first hole 91 for common wiring is formed in a portion of the actuator plate 54 that is located on the -X side with respect to the -X side common electrode 81a2. The first hole 91 for common wiring is a long groove that penetrates the actuator plate 54 in the Z direction and extends in the Y direction. The first through-wiring 81e is formed on the inner surface of the first hole 91 for common wiring. The first through-wiring 81e is formed over at least the entire region in the Z direction on the inner surface of the first hole 91 for common wiring. The first through-wiring 81e is connected to the back-surface routing wiring 81c at the -Z side opening edge of the first hole 91 for common wiring, while being connected to the front-surface routing wiring 81d at the +Z side opening edge of the first hole 91 for common wiring.

[0049] FIG. 9 is a plan view of the cover plate 56. As shown in FIGS. 4 and 9, the second through-wiring 81f routes the first through-wiring 81e to the surface of the cover plate 56. The second through-wiring 81f is provided so as to penetrate the film 55 and the cover plate 56 in the Z direction. Specifically, a second hole 92 for common wiring is formed at a position where the film 55 and the cover plate 56 overlap with the first hole 91 for common wiring when viewed in the Z direction. The second hole 92 for common wiring is a long groove that penetrates the film 55 and the cover plate 56 in the Z direction and extends in the Y direction, similar to the first hole 91 for common wiring. The second hole 92 for common wiring communicates with the first hole 91 for common wiring. The second through-wiring 81f is formed on the inner surface of the second hole 92 for common wiring. The second through-wiring 81f is formed over at least the entire region in the Z direction on the inner surface of the second hole 92 for common wiring. The second through-wiring 81f is connected to the first through-wiring 81e at the -Z side opening edge of the second hole 92 for common wiring.

[0050] As shown in FIG. 9, the common pad 81g is formed on the surface of the cover plate 56. The common pad 81g extends in the X direction in a portion of the surface of the cover plate 56 that overlaps with the pressure chamber 61 when viewed from the Z direction. The -X side end portion of the common pad 81g is connected to the second through wiring 81f at the +Z side opening edge of the second hole 92 for common wiring.

[0051] As shown in FIGS. 7 and 8, the individual wiring 82 includes a first individual electrode 82a, a second individual electrode 82b, a back surface routing wiring 82c, a front surface routing wiring 82d, a first through wiring 82e, a second through wiring 82f, and an individual pad 82g.

[0052] As shown in FIGS. 4 and 7, the first individual electrode 82a is formed between the first common electrodes 81a on the back surface of the actuator plate 54. The first individual electrode 82a extends in the Y direction while being spaced apart from each first common electrode 81a in the X direction. The first individual electrode 82a generates a potential difference with the first common electrode 81a. At least a part of the first individual electrode 82a overlaps with the second common electrode 81b when viewed from the Z direction. Therefore, the first individual electrode 82a generates a potential difference with the second common electrode 81b.

[0053] As shown in FIGS. 4 and 8, the second individual electrode 82b is formed on the surface of the actuator plate 54 in portions located on both sides in the X direction with respect to the second common electrode 81b. Each second individual electrode 82b extends in the Y direction while being spaced apart from the second common electrode 81b in the X direction. The second individual electrode 82b generates a potential difference with the second common electrode 81b.

[0054] As shown in FIGS. 4 and 8, the second individual electrode 82b located on the +X side among the second individual electrodes 82b (hereinafter referred to as the +X side individual electrode 82b1) generates a potential difference with the +X side common electrode 81a1. A part of the +X side individual electrode 82b1 overlaps with the partition wall 62a when viewed from the Z direction. The +X side individual electrode 82b1 faces the +X side common electrode 81a1 in the Z direction on the partition wall 62a.

[0055] On the other hand, among the second individual electrodes 82b, the second individual electrode 82b located on the -X side (hereinafter referred to as the -X side individual electrode 82b2) generates a potential difference with the -X side common electrode 81a2. A part of the -X side individual electrode 82b1 overlaps with the partition wall 62b when viewed from the Z direction. The -X side individual electrode 82b2 faces the -X side common electrode 81a2 in the Z direction on the partition wall 62b.

[0056] As shown in FIG. 7, the back surface routing wiring 82c is connected to the first individual electrode 82a on the back surface of the actuator plate 54. The back surface routing wiring 82c extends in the X direction from the +Y side end portion of the first individual electrode 82a.

[0057] As shown in FIG. 8, the front surface routing wiring 82d is collectively connected to each second individual electrode 82b on the front surface of the actuator plate 54. The front surface routing wiring 82d extends in the X direction while being connected to the +Y side end portions of the second individual electrodes 82b.

[0058] As shown in FIGS. 4, 7, and 8, the first through wiring 82e connects between the back surface routing wiring 82c and the front surface routing wiring 82d. The first through wiring 82e is provided to penetrate the actuator plate 54 in the Z direction. Specifically, in the portion of the actuator plate 54 located on the +X side with respect to the +X side individual electrode 82b1, a first hole 93 for individual wiring is formed. The first hole 93 for individual wiring is a long groove that penetrates the actuator plate 54 in the Z direction and extends in the Y direction. On the inner surface of the first hole 93 for individual wiring, the first through wirings 82e of the adjacent pressure chambers 61 are formed in a state of being separated from each other. The first through wiring 82e is connected to the back surface routing wiring 82c at the lower end opening edge of the first hole 93 for individual wiring, while being connected to the front surface routing wiring 82d at the +Z side opening edge of the first hole 93 for individual wiring.

[0059] As shown in FIGS. 4 and 9, the second through-wiring 82f extends the first through-wiring 82e to the surface of the cover plate 56. The second through-wiring 82f is provided to penetrate the film 55 and the cover plate 56 in the Z direction. Specifically, a second hole 94 for individual wiring is formed at a position where the first hole 93 for individual wiring in the film 55 and the cover plate 56 overlaps when viewed from the Z direction. The second hole 94 for individual wiring penetrates the film 55 and the cover plate 56 in the Z direction and is a long groove extending in the Y direction similar to the first hole 93 for individual wiring. The second hole 94 for individual wiring communicates with the first hole 93 for individual wiring. On the inner surface of the second hole 94 for individual wiring, the second through-wirings 82f of adjacent pressure chambers 61 are formed in a separated state from each other. The second through-wiring 82f is connected to the first through-wiring 82e at the -Z side opening edge of the second hole 94 for individual wiring.

[0060] The individual pad 82g is formed on the surface of the cover plate 56. The individual pad 82g extends in the X direction on the surface of the cover plate 56 at a portion that overlaps the pressure chamber 61 when viewed from the Z direction. The +X side end portion of the individual pad 82g is connected to the second through-wiring 82f at the +Z side opening edge of the second hole 94 for individual wiring.

[0061] As shown in FIG. 4, the portion of the drive wiring 75 formed on the surface of the actuator plate 54 is covered with the film 55. Specifically, among the drive wirings 75, the second common electrode 81b, the second individual electrode 82b, the surface routing wirings 81d, 82d, and the first through-wirings 81e, 82e are covered with the film 55.

[0062] As shown in FIGS. 5 and 9, a common separation groove 96 is formed on the surface of the cover plate 56. The common separation groove 96 extends in the X direction so as to cross between the pressure chambers 61 at a portion of the surface of the cover plate 56 that is located between the common pad 81g and the individual pad 82g. A flexible printed circuit board 97 is pressure-bonded to the surface of the cover plate 56. The flexible printed circuit board 97 is mounted on the common pad 81g and the individual pad 82g on the surface of the cover plate 56. The flexible printed circuit board 97 is drawn out to the +Z side. Each common wiring 81 (common pad 81g) corresponding to the plurality of pressure chambers 61 is made common on the flexible printed circuit board 97.

[0063] Here, as shown in FIGS. 3 to 5, the first protective film 53 is integrally formed in a sheet shape (film shape), and is arranged so as to partition between the pressure chamber 61 and the drive unit 54a by a so-called skin pack. The first protective film 53 is provided on the back surface of the actuator plate 54 and on the side surface of the laminate 100 (the laminate of the actuator plate 54, the film 55, and the cover plate 56) via an adhesive. For example, an EVA-based adhesive is preferably used as the adhesive. However, as the adhesive, in addition to the EVA-based adhesive, acrylic-based, epoxy-based, silicone-based, urethane-based, etc. can also be used.

[0064] The first protective film 53 includes a back surface protection portion (first covering portion) 53a, a +X side protruding portion 53b, a -X side protruding portion 53c, a +Y side protruding portion 53d, and a -Y side protruding portion 53e. The back surface protection part 53a is sandwiched between the actuator plate 54 and the flow path member 52. The back surface protection part 53a covers the entire back surface of the actuator plate 54 in a state of being in direct or indirect contact with the back surface of the actuator plate 54. That is, in the portion of the back surface of the actuator plate 54 where the drive wiring 75 is not formed, the back surface protection part 53a is in direct contact with the back surface of the actuator plate 54. In the portion of the back surface of the actuator plate 54 where the drive wiring 75 is formed, the back surface protection part 53a covers the back surface of the actuator plate 54 in a state of being in contact with the drive wiring 75 (for example, the first common electrode 81a, the first individual electrode 82a, the back surface routing wiring 81c, 82c, etc.). Further, the back surface protection part 53a closes the lower end opening of the first hole 91 for common wiring and the -Z side opening of the first hole 93 for individual wiring. In the first embodiment, since the back surface protection part 53a is continuously formed over the entire back surface of the actuator plate 54, the exposure of the drive wiring 75 into the pressure chamber 61 is suppressed. Note that the back surface protection part 53a is joined to the surface of the flow path member 52 via an adhesive or the like.

[0065] The +X side protruding part 53b is the part of the first protective film 53 that protrudes toward the +X side with respect to the actuator plate 54. The +X side protruding part 53b extends continuously along the entire length of the +X side edge of the back surface protection part 53a. The +X side protruding part 53b is bent toward the +Z side with respect to the back surface protection part 53a on the +X side with respect to the actuator plate 54. The +X side protruding part 53b is in contact with the side surface of the laminate 100 that faces the +X side. The +X side protruding part 53b extends over the entire Y direction on the side surface of the laminate 100 that faces the +X side. The -X side protrusion 53c is the portion of the first protective film 53 that protrudes toward the -X side with respect to the actuator plate 54. The -X side protrusion 53c extends continuously along the entire length of the -X side edge of the back surface protection portion 53a. The -X side protrusion 53c is bent toward the +Z side with respect to the back surface protection portion 53a on the -X side with respect to the actuator plate 54. The -X side protrusion 53c is in close contact with the side surface of the laminate 100 that faces the -X side. The -X side protrusion 53c extends across the entire Y-direction on the side surface of the laminate 100 that faces the -X side.

[0066] The +Y side protrusion 53d is the portion of the first protective film 53 that protrudes toward the +Y side with respect to the actuator plate 54. The +Y side protrusion 53d extends continuously along the entire length of the +Y side edge of the back surface protection portion 53a. The +Y side protrusion 53d is bent toward the +Z side with respect to the back surface protection portion 53a on the +Y side with respect to the actuator plate 54. The +Y side protrusion 53d is in close contact with the side surface of the laminate 100 that faces the +Y side. The +Y side protrusion 53d extends across the entire X-direction on the side surface of the laminate 100 that faces the +Y side. The -Y side protrusion 53e is the portion of the first protective film 53 that protrudes toward the -Y side with respect to the actuator plate 54. The -Y side protrusion 53e extends continuously along the entire length of the -Y side edge of the back surface protection portion 53a. The -Y side protrusion 53e is bent toward the +Z side with respect to the back surface protection portion 53a on the -Y side with respect to the actuator plate 54. The -Y side protrusion 53e is in close contact with the side surface of the laminate 100 that faces the -Y side. The -Y side protrusion 53e extends across the entire X-direction on the side surface of the laminate 100 that faces the -Y side. Therefore, the entire circumference of the side surface of the laminate 100 is covered by the respective protrusions 53b to 53e.

[0067] In addition, it is preferable that each of the protruding portions 53b to 53e covers a boundary portion between the back surface protection portion 53a and the actuator plate 54 among the side surfaces of the laminate 100, more preferably covers up to a boundary portion between the film 55 and the actuator plate 54, or covers a boundary portion between the film 55 and the cover plate 56.

[0068] For the first protective film 53 of the first embodiment, a thermoplastic resin material having excellent insulation and ink resistance and a softening point (Vicat softening temperature conforming to JIS K7206) of 120°C or lower, more preferably 100°C or lower, is preferably used. In the first embodiment, the first protective film 53 is composed of a single-layer film such as an ionomer (softening point of 57°C to 80°C) or low-density polyethylene (softening point of 85°C to 97°C), or a laminated film. When a laminated film is adopted for the first protective film 53, it is preferable to use a material having excellent flexibility (for example, an ionomer or the like) as the base layer and a material having excellent ink resistance (for example, low-density polyethylene or the like) as the surface layer. Further, the thickness of the first protective film 53 is formed, for example, in the range of 10 μm to 200 μm.

[0069] [Operation method of printer 1] Next, the case of recording characters, figures, etc. on the recording medium P using the printer 1 configured as described above will be described below. Note that, as an initial state, it is assumed that the four ink tanks 4 shown in FIG. 1 are each sufficiently filled with ink of a different color. Also, the ink in the ink tank 4 is in a state of being filled into the inkjet head 5 via the ink circulation mechanism 6.

[0070] In such an initial state, when the printer 1 is operated, the recording medium P is conveyed in the +X direction 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, so that the inkjet head 5 mounted on the carriage 29 reciprocates in the Y direction. While the inkjet head 5 reciprocates, ink is appropriately ejected from each inkjet head 5 onto the recording medium P. Thereby, recording such as characters and images can be performed on the recording medium P.

[0071] Here, the movement of each inkjet head 5 will be described in detail below. In a circulation type side shoot type inkjet head 5 as in the present embodiment, first, by operating the pressure pump 24 and the suction pump 25 shown in FIG. 2, ink is circulated in the circulation channel 23. In this case, the ink flowing through the ink supply pipe 21 is supplied into each pressure chamber 61 through the inlet side common channel 64 and the inlet side communication channel 65. The ink supplied into each pressure chamber 61 flows through each pressure chamber 61 in the Y direction. Then, the ink is discharged into the outlet side common channel 66 through the outlet side communication channel 67, and then returned to the ink tank 4 through the ink discharge pipe 22. Thereby, ink can be circulated between the inkjet head 5 and the ink tank 4.

[0072] When the reciprocating movement of the inkjet head 5 is started by the movement of the carriage 29 (see FIG. 1), a driving voltage is applied between the common electrodes 81a, 81b and the individual electrodes 82a, 82b via the flexible printed circuit board 97. At this time, the common electrodes 81a, 81b are set as the reference potential GND, and the individual electrodes 82a, 82b are set as the driving potential Vdd to apply the driving voltage.

[0073] By applying a driving voltage, a potential difference is generated in the X direction between the first common electrode 81a and the first individual electrode 82a, and between the second common electrode 81b and the second individual electrode 82b. Due to the potential difference generated in the X direction, an electric field is generated in the actuator plate 54 in a direction orthogonal to the polarization direction (Z direction). As a result, the actuator plate 54 undergoes thickness-shear deformation in the Z direction in the shear mode. Specifically, on the back surface of the actuator plate 54, an electric field is generated in a direction approaching each other in the X direction between the first common electrode 81a and the first individual electrode 82a. On the front surface of the actuator plate 54, an electric field is generated in a direction separating from each other in the X direction between the second common electrode 81b and the second individual electrode 82b. As a result, the portions of the actuator plate 54 corresponding to the respective pressure chambers 61 undergo shear deformation upward as they move from both ends in the X direction toward the central portion.

[0074] On the other hand, a potential difference is generated in the Z direction between the first common electrode 81a and the second individual electrode 82b, and between the first individual electrode 82a and the second common electrode 81b. Due to the potential difference generated 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 undergoes expansion and contraction deformation in the Z direction in 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, by applying a driving voltage, the actuator plate 54 deforms in a direction away from the pressure chamber 61. As a result, the volume inside the pressure chamber 61 expands. Then, when the driving voltage is set to zero, as the actuator plate 54 restores, the volume inside the pressure chamber 61 attempts to return to its original state. During the process of the actuator plate 54 restoring, the pressure inside the pressure chamber 61 increases, and the ink inside the pressure chamber 61 is ejected to the outside through the nozzle hole 71. When the ink ejected to the outside lands on the recording medium P, print information is recorded on the recording medium P.

[0075] <Manufacturing method of the head chip 50> Next, the manufacturing method of the above-described head chip 50 will be described. FIG. 10 is a flowchart for explaining the manufacturing method of the head chip 50. FIGS. 11 to 17 are process diagrams for explaining the manufacturing method of the head chip 50. In the following description, for convenience, the case of manufacturing the head chip 50 at the chip level will be described as an example. As shown in FIG. 10, the manufacturing method of the head chip 50 includes a laminate processing step S1, a protective film forming step S2, a flow path member first processing step S3, a first bonding step S4, a flow path member second processing step S5, and a second bonding step S6.

[0076] As shown in FIG. 11, in the laminate processing step S1, a laminate 100 in which a drive wiring 75 is formed and an actuator plate 54, a film 55, and a cover plate 56 are laminated is formed. Specifically, for a part of the drive wiring 75 (common electrodes 81a, 81b, individual electrodes 82a, 82b, various routing wirings 81c, 81d, 82c, 82d, first through wirings 81e, 82e), for example, they are formed on the actuator plate 54 by a vapor deposition method or the like. On the other hand, for the remaining part of the drive wiring 75 (second through wirings 81f, 82f, common pad 81g, and individual pad 82g), after laminating the film 55 and the cover plate 56 on the surface of the actuator plate 54, they are formed on the cover plate 56 by a vapor deposition method or the like.

[0077] As shown in FIG. 12, in the protective film forming step S2, a first protective film 53 is formed on the laminate 100. In the protective film forming step S2, first, an adhesive is applied to the formation region of the first protective film 53 in the laminate 100. Subsequently, with the laminate 100 and the first protective film 53 facing each other, they are set in the chamber 101. Specifically, the laminate 100 is set on the stage 102 in the chamber 101 via the base film 103 with the back surface of the actuator plate 54 facing upward. The base film 103 is formed of a material that can be peeled off from both the actuator plate 54 and the first protective film 53. On the other hand, the first protective film 53 is set at a distance from the laminate 100 in the chamber 101. Among the first protective films 53, the portion outside the laminate 100 in plan view is held by a jig or the like (not shown). That is, the portion of the first protective film 53 located outside the laminate 100 also functions as a gripping margin for gripping the first protective film 53 in the chamber 101. Note that the first protective film 53 has a thickness about 2 to 5 times that in the state before being in close contact with the laminate 100 compared to the state after being in close contact with the laminate 100. Note that the adhesive may be applied to the first protective film 53 instead of the laminate 100.

[0078] With the laminate 100 and the first protective film 53 set in the chamber 101, the inside of the chamber 101 is heated so that the first protective film 53 reaches a temperature equal to or higher than the softening point within a range below the Curie point (the temperature at which polarization is completely destroyed) of the actuator plate 54. Then, the first space S1 (lower space) located on the actuator plate 54 side with respect to the first protective film 53 in the chamber 101 is made to have a negative pressure with respect to the second space S2 (upper space) located on the side opposite to the actuator plate 54 with respect to the first protective film 53.

[0079] Then, as shown in FIG. 13, due to the pressure difference between the first space S1 and the second space S2, the first protective film 53 approaches the laminate 100. Thereafter, the first protective film 53 contacts the laminate 100 and deforms while being stretched so as to follow the outer surface shape of the laminate 100. As a result, the first protective film 53 adheres closely to the outer surface of the laminate 100, and the skin pack body 110 shown in FIG. 14 is formed. Thereafter, after cooling the inside of the chamber 101 so that the first protective film 53 becomes below the softening point, the skin pack body 110 is taken out of the chamber 101. Specifically, the skin pack body 110 is taken out together with the base film 103 by cutting the first protective film 53 and the base film 103 around the laminate 100. Thereafter, the base film 103 is peeled off from the skin pack body 110. In the protective film forming step S2, the first protective film 53 and the laminate 100 (stage 102) may be moved closer to each other while generating a pressure difference between the first space S1 and the second space S2.

[0080] As shown in FIG. 15, in the first channel member processing step S3, a channel 60 (see FIG. 6) and a pressure chamber 61 are formed in the channel member 52. The channel 60 and the pressure chamber 61 are formed by performing, for example, sandblasting on the channel member 52.

[0081] As shown in FIG. 16, in the first bonding step S4, the channel member 52 is attached to the back surface of the first protective film 53 (back surface protection portion 53a) with an adhesive or the like.

[0082] As shown in FIG. 17, in the second channel member processing step S5, grinding is performed on the back surface of the channel member 52 (grinding step). At this time, the channel member 52 is ground on the back surface up to the positions where the channels 60 and the pressure chamber 61 open.

[0083] In the second bonding step S6, the nozzle plate 51 is attached to the back surface of the channel member 52 with the nozzle hole 71 and the pressure chamber 61 aligned. Thus, the head chip 50 is completed.

[0084] When manufacturing the head chip 50 at the wafer level, a laminate of a wafer for an actuator plate, a film, and a wafer for a cover plate is formed. Thereafter, the first protective film 53 may be formed for each laminate after the laminate of wafers is diced, or the laminate of wafers may be diced after the first protective film 53 is formed for the entire laminate of wafers.

[0085] As described above, the head chip 50 of the first embodiment includes a flow path member 52 in which a plurality of pressure chambers 61 are formed side by side in the X direction (first direction), an actuator plate 54 disposed facing the pressure chamber 61 in the Z direction (second direction), drive wirings 75 respectively formed on the back surface (flow path facing surface) of the drive portion 54a of the actuator plate 54, and a back surface protection portion (first covering portion) 53a that covers the drive wiring 75 on the back surface of the drive portion 54a, and includes a sheet-like first protective film 53 that partitions between the pressure chamber 61 and the drive portion 54a. According to this configuration, by covering the back surface of the drive portion 54a with the sheet-like first protective film 53, unlike a configuration in which a deposited film made of a para-xylene resin material or the like is formed by a film formation method such as CVD as in the prior art, the occurrence of discontinuous portions such as pinholes can be suppressed. That is, by protecting the back surface of the actuator plate 54 with the continuously formed sheet-like first protective film 53, it is possible to suppress ink from reaching the drive wiring 75 formed on the back surface of the actuator plate 54. Thereby, short circuits, corrosion, etc. of the drive wiring 75 can be suppressed, and a head chip 50 with excellent reliability can be provided. Further, by adopting the sheet-like first protective film 53, a simpler and lower-cost first protective film 53 can be provided compared to a configuration in which a deposited film is formed by a film formation method such as CVD. As a result, the manufacturing efficiency of the head chip can be improved, and the cost of the head chip can be reduced.

[0086] In the head chip 50 of the first embodiment, the first protective film 53 is configured to include protruding portions 53b to 53e that protrude outward in the X direction and the Y direction (crossing direction) with respect to the flow path member 52 and the actuator plate 54. According to this configuration, when providing the first protective film 53 on the back surface of the actuator plate 54, the protruding portions 53b to 53e can be used as the gripping margin in the protective film forming step S2 and as the absorption margin for the positional deviation between the actuator plate 54 and the first protective film 53 in the X direction or the Y direction. Thereby, the manufacturing efficiency of the head chip 50 can be improved.

[0087] In the head chip 50 of the first embodiment, the protruding portions 53b to 53e are configured to cover the side surface of the actuator plate 54. According to this configuration, the boundary portion between the back surface protection portion 53a and the actuator plate 54 is covered by the protruding portion 53b. Therefore, it is possible to suppress the entry of a liquid such as ink from the outside of the head chip 50 into the interface between the back surface protection portion 53a and the actuator plate 54. Thereby, the reliability of the head chip 50 can be improved.

[0088] In the head chip 50 of the first embodiment, the Y - side protruding portions 53d and 53e are configured to extend in the X direction on the portion of the side surface of the actuator plate 54 that faces the Y direction. According to this configuration, the Y - side protruding portions 53d and 53e are arranged along the arrangement direction of the pressure chambers 61 on the side surface of the actuator plate 54. Thereby, even if ink enters the interface between the flow path member 52 and the first protective film 53 (back surface protection portion 53a), it is possible to suppress the ink from bridging between the drive wirings 75 corresponding to different pressure chambers 61.

[0089] In the head chip 50 of the first embodiment, the first protective film 53 (back surface protection portion 53a) is configured to be continuously provided over the entire back surface of the actuator plate 54. According to this configuration, since the entire back surface of the actuator plate 54 is covered by the back surface protection portion 53a, it is possible to more reliably suppress the ink from reaching the drive wiring 75.

[0090] In the head chip 50 of the first embodiment, the softening point of the first protective film 53 is set to 120°C or lower. According to this configuration, in the protective film forming step S2, when the first protective film 53 is heated and adhered to the back surface of the actuator plate 54 (drive unit 54a), it is possible to suppress the occurrence of polarization breakdown (for example, about 130°C) of the actuator plate 54. Thereby, a head chip 50 with excellent reliability can be provided.

[0091] In the head chip 50 of the first embodiment, the first protective film 53 is formed of a thermoplastic resin. According to this configuration, in the protective film forming step S2, by heating the first protective film 53, the first protective film 53 can be easily deformed. Thereby, the first protective film 53 can be easily adhered to the back surface of the actuator plate 54 (drive unit 54a).

[0092] In the head chip 50 of the first embodiment, in the protective film forming step S2, the first protective film 53 is adhered by the pressure difference between the first space S1 and the second space S2. According to this configuration, the protective portion 53a can be quickly adhered to the drive unit 54a.

[0093] Since the printer 1 and the inkjet head 5 of the first embodiment include the above-described head chip 50, a printer 1 and an inkjet head 5 with excellent reliability can be provided.

[0094] (Second Embodiment) FIG. 18 and FIG. 19 are cross-sectional views of the head chip 50 according to the second embodiment. In the head chip 50 shown in FIGS. 18 and 19, the second protective film 253 is formed following the inner surface of the pressure chamber 61 and the back surface of the flow path member 52. In the second embodiment, among the head chip 50, the flow path member 52, the actuator plate 54, the film 55, and the cover plate 56 constitute a laminate 200, and the laminate 200 is covered with the second protective film 253 to constitute a skin pack body 210.

[0095] The second protective film 253 includes an actuator protection part (first covering part) 253a, a flow path protection part 253b, and protruding parts 253c to 253f. The actuator protection part 253a continuously covers the entire back surface of the drive part 54a. Thereby, the actuator protection part 253a partitions between the pressure chamber 61 and the drive part 54a.

[0096] The flow path protection part 253b is integrally provided along the inner surface of the pressure chamber 61, the inner surfaces of the various flow paths 60, and the back surface of the flow path member 52 among the flow path members 52. The flow path protection part 253b includes a pressure chamber covering part (second covering part) 255, a flow path covering part 256, and a back surface covering part (third covering part) 257.

[0097] The pressure chamber covering part 255 is continuous with the entire outer peripheral edge of the actuator protection part 253a. The pressure chamber covering part 255 continuously covers the entire inner side surface of the pressure chamber 61. The flow path covering part 256 is continuous with the actuator protection part 253a or the pressure chamber covering part 255. The flow path covering part 256 is continuously provided over the entire inner surface of the various flow paths 60 (the inlet side common flow path 64, the inlet side communication path 65, the outlet side common flow path 66, the outlet side communication path 67, and the bypass path 68). The flow path covering part 256 covers the inner surfaces of the various flow paths 60. The back surface covering part 257 is continuous with the pressure chamber covering part 255 or the flow path covering part 256. The back surface covering part 257 covers the entire back surface of the flow path member 52. That is, the back surface covering part 257 is sandwiched between the flow path member 52 and the nozzle plate 51. The back surface covering part 257 is joined to the nozzle plate 51 via an adhesive.

[0098] Each of the protruding portions 253c to 253f is connected to the outer peripheral edge of the back surface covering portion 257. Similar to the protruding portions 53b to 53e of the first embodiment, each of the protruding portions 253c to 253f protrudes in a plan view with respect to the flow path member 52 and covers the corresponding side surface among the side surfaces of the laminate 200. Note that each of the protruding portions 253c to 253f preferably covers the boundary portion between the flow path member 52 and the actuator plate 54, more preferably covers up to the boundary portion between the film 55 and the actuator plate 54, or covers the boundary portion between the film 55 and the cover plate 56.

[0099] The second protective film 253 of the second embodiment can be formed by performing the above-described protective film forming step S2 between the flow path member second processing step S5 and the second bonding step S6. That is, with the flow path member 52 laminated on the actuator plate 54, by performing the protective film forming step S2, the second protective film 253 adheres closely following the inner surface of the pressure chamber 61 and the back surface of the flow path member 52. Thereby, the skin pack body 210 is formed. Then, by attaching the nozzle plate 51 to the back surface of the second protective film 253 (back surface covering portion 257), the head chip 50 is completed.

[0100] In the head chip 50 of the second embodiment, the second protective film 253 is configured to include a pressure chamber covering portion 255 that is continuous with the actuator protection portion 253a and covers the portion of the flow path member 52 facing the pressure chamber 61, and a back surface covering portion 257 that is continuous with the pressure chamber covering portion 255 and covers the back surface of the flow path member 52 (the surface facing the injection hole plate). According to this configuration, since the interface between the actuator plate 54 and the flow path member 52 is covered by the second protective film 253, the entry of ink into the interface between the actuator plate 54 and the flow path member 52 can be suppressed. Moreover, since the back surface of the flow path member 52 is covered by the back surface covering portion 257, even if the back surface covering portion 257 is damaged and ink enters the interface between the flow path member 52 and the second protective film 253, it is possible to suppress the ink from reaching the interface between the actuator plate 54 and the flow path member 52, and suppress the peeling between the actuator plate 54 and the flow path member 52. Further, by separating the distance to the interface between the second protective film 253 and the flow path member 52 by the thickness of the second protective film 253, even if the pressure chamber covering portion 255 is damaged, it is possible to suppress the ink from reaching the interface between the actuator plate 54 and the flow path member 52, and suppress the peeling between the actuator plate 54 and the flow path member 52.

[0101] (Third Embodiment) FIGS. 20 and 21 are cross-sectional views of the head chip 50 according to the third embodiment. The third embodiment is different from the above-described embodiments in that both the first protective film 53 and the second protective film 253 are formed. In the head chip 50 shown in FIGS. 20 and 21, the first protective film 53 continuously covers the back surface of the actuator plate 54 and the side surfaces of the actuator plate 54, the film 55, and the cover plate 56. That is, the first protective film 53 covers the first laminate 301 including the actuator plate 54, the film 55, and the cover plate 56 from the -Z side and the side. In the third embodiment, the back surface protection portion 53a constitutes the first protection portion according to the present disclosure.

[0102] The second protective film (second protective portion) 253 is provided so as to cover the first protective film 53 from the outside. In this case, the actuator protection portion (first covering portion) 253a is in close contact with the back surface of the back surface protection portion 53a. Also, the corresponding protruding portions 53b to 53e and 253c to 253f are in close contact with each other on the corresponding side surfaces. That is, the second protective film 253 covers the second laminate 302 including the flow path member 52, the first protective film 53, the actuator plate 54, the film 55, and the cover plate 56 from the -Z side and laterally.

[0103] According to the head chip 50 of the third embodiment, since the entire back surface of the actuator plate 54 is covered by the first protective film 53 (back surface protection portion 53a), it is possible to more reliably suppress ink from reaching the drive wiring 75. Moreover, since the interface between the actuator plate 54 and the flow path member 52 is covered by the second protective film 253 (pressure chamber covering portion 255), it is possible to suppress the entry of ink into the interface between the actuator plate 54 and the flow path member 52. Thereby, peeling between the actuator plate 54 and the flow path member 52 can be suppressed.

[0104] (Fourth Embodiment) FIG. 22 is a cross-sectional view of the head chip 50 according to the fourth embodiment. In the head chip 50 shown in FIG. 22, in the actuator plate 54, recesses 401 are formed in portions that overlap with the respective pressure chambers 61 in a plan view. The recesses 401 are recessed upward with respect to the back surface of the actuator plate 54. Specifically, the recesses 401 extend in the Y direction along the pressure chambers 61 in a plan view. The recesses 401 are formed in a rectangular shape when viewed from the Y direction.

[0105] An individual electrode 82a is formed on the inner surface of the recess 401. In the illustrated example, the individual electrode 82a is formed over the entire inner surface of the recess 401. At least a part of the individual electrode 82a overlaps with the second common electrode 81b when viewed in the Z direction. Note that the individual electrode 82a may be formed on at least a part of the inner surface of the recess 401. Further, in addition to the inner surface of the recess 401, the individual electrode 82a may be continuous with a portion of the back surface of the actuator plate 54 that is located around the recess 401.

[0106] Groove portions 402 are formed in portions of the actuator plate 54 that are located on both sides in the X direction with respect to the recess 401. The groove portions 402 overlap, in plan view, with portions of the flow path member 52 that are located between adjacent pressure chambers 61. The groove portions 402 are recessed with respect to the surface of the actuator plate 54. The groove portions 402 extend in the Y direction along the recess 401. In the illustrated example, the dimension of the groove portions 402 in the Z direction is larger than the dimension of the recess 401 in the Z direction. The dimension of the groove portions 402 in the X direction is smaller than the dimension of the recess 401 in the X direction.

[0107] A third common electrode 481c is formed on the inner surface of the groove portions 402. The third common electrode 481c is formed over the entire inner surface area of each groove portion 402. That is, the third common electrode 481c is disposed on both sides in the X direction with respect to the second common electrode 81b. Note that the third common electrode 481c may be formed on at least a part of the inner surface of the groove portions 402.

[0108] The first protective film 53 is provided so as to cover the laminate 100 from the -Z side and laterally. In this case, a part of the back surface protective portion 53a is provided following the entire inner surface of the recess 401, thereby covering the individual electrode 82a.

[0109] According to the fourth embodiment, by forming the drive wiring 75 (individual electrode 82a) along the inner surface of the concave portion 401, the surface area of the individual electrode 82a can be ensured. As a result, the electric field generated in the actuator plate 54 can be increased, and the pressure generated in the pressure chamber 61 during ink ejection can be improved. Moreover, by forming the concave portion 401 in the actuator plate 54, the rigidity of the actuator plate 54 in the Z direction can be enhanced.

[0110] (Other Modification Examples) Note that 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-described embodiments, as an example of the liquid ejection recording apparatus, the inkjet printer 1 has been described as an example, but it is not limited to printers. For example, a facsimile machine, an on-demand printer, or the like may be used. In the above-described embodiments, the configuration in which the inkjet head moves with respect to the recording medium during printing (so-called shuttle mechanism) 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 is moved with respect to the inkjet head while the inkjet head is fixed (so-called fixed head mechanism). In the above-described embodiments, the case where the recording medium P is paper has been described, but the present disclosure is not limited to this configuration. The recording medium P is not limited to paper, and may be a metal material, a resin material, or food. In the above-described embodiments, the configuration in which the liquid ejection head is mounted on the liquid ejection recording apparatus has been described, but the present disclosure is not limited to this configuration. That is, the liquid ejected from the liquid ejection head is not limited to that which lands on the recording medium, and may be, for example, a chemical solution to be blended in a preparation, a food additive such as a seasoning or a flavor added to food, or a fragrance sprayed into the air.

[0111] In the above-described embodiments, the configuration in which the Z direction coincides with the gravitational direction has been described, but the present disclosure is not limited to this configuration only, and the Z direction may be along the horizontal direction. In the above-described embodiment, the configuration in which the protective film is formed by a so-called skin pack has been described, but the configuration is not limited thereto. The protective film may be formed by pressure bonding or the like. In the above-described embodiment, the configuration in which each protruding portion covers the side surface of the laminate has been described, but the configuration is not limited thereto. The protruding portion only needs to protrude outward in a plan view with respect to at least the actuator plate 54. In this case, the protruding portion may be configured to be used only as a gripping margin of the protective film in the protective film forming step S2. In the above-described embodiment, the method of heating the protective film in the protective film forming step S2 has been described, but the configuration is not limited thereto. The protective film forming step S2 may be performed at room temperature.

[0112] In the above-described embodiment, the configuration in which the protruding portion covers the entire circumference of the side surface of the laminate has been described, but the configuration is not limited thereto. The protruding portion may cover a part of the side surface of the laminate. In this case, the protruding portion preferably covers the side surface facing the Y direction among the side surfaces of the laminate. In the above-described embodiment, the configuration in which the space between each drive unit 54a and each pressure chamber 61 is continuously partitioned by a single protective film has been described, but the configuration is not limited thereto. The protective film may separately partition the corresponding drive unit 54a and pressure chamber 61.

[0113] In addition, without departing from the spirit of the present disclosure, it is possible to appropriately replace the components in the above-described embodiment with well-known components, and the above-described modified examples may be appropriately combined.

Explanation of Reference Numerals

[0114] 1: Printer (Liquid Jet Recording Apparatus) 5: Ink Jet Head (Liquid Jet Head) 50: Head Chip 51: Nozzle Plate (Injection Hole Plate) 51a: Nozzle Hole (Injection Hole) 52: Flow Path Member 53: First Protective Film (Protective Film) 53a: Back protection part (first covering part, first protection part) 53b: +X side protruding part 53c: -X side protruding part 53d: +Y side protruding part 53e: -Y side protruding part 54: Actuator plate 54a: Driving part 61: Pressure chamber 75: Driving wiring 101: Chamber 253: Second protective film (protective film, second protection part) 253a: Actuator protection part (first covering part) 253c: +X side protruding part 253d: -X side protruding part 253e: +Y side protruding part 253f: -Y side protruding part 255: Pressure chamber covering part (second covering part) 257: Back protection part (third covering part) 401: Concave part

Claims

1. A flow path member in which a plurality of pressure chambers for containing a liquid are arranged side by side in a first direction, An actuator plate disposed on the flow path member in a state facing the pressure chamber in a second direction intersecting the first direction, Drive wirings respectively formed on flow path facing surfaces facing the flow path member in drive portions of the actuator plate that overlap the pressure chamber when viewed from the second direction, A head chip including a first covering portion covering the drive wiring on the flow path facing surface, and a sheet-like protective film partitioning between the pressure chamber and the drive portion.

2. The head chip according to claim 1, wherein the protective film includes a protruding portion protruding outward in an intersecting direction intersecting the second direction when viewed from the second direction with respect to the flow path member and the actuator plate.

3. The head chip according to claim 2, wherein the protruding portion covers a side surface of the actuator plate facing the intersecting direction.

4. The head chip according to claim 3, wherein the protruding portion extends along the first direction in a portion of the side surface facing a third direction intersecting the first direction among the intersecting directions.

5. The head chip according to any one of claims 1 to 4, wherein the protective film is continuously provided over the entire area of the flow path facing surface.

6. A recess is formed in the drive portion in a direction away from the flow path member in the second direction, The drive wiring is formed on an inner surface of the recess, The head chip according to claim 5, wherein the first covering portion is provided following the inner surface of the recess so as to cover the drive wiring.

7. An injection hole plate in which injection holes communicating with the pressure chamber are formed is provided on the side opposite to the actuator plate in the second direction with respect to the flow path member, The protective film, A second covering portion that is continuous with the first covering portion and covers a portion of the flow path member facing the pressure chamber, The head chip according to any one of claims 1 to 4, further including a third covering portion that is continuous with the second covering portion and covers a surface of the flow path member facing the injection hole plate in the second direction.

8. An injection hole plate in which injection holes communicating with the pressure chamber are formed is provided on the side opposite to the actuator plate in the second direction with respect to the flow path member, The protective film, A first protection part continuously provided across the entire area of the flow path facing surface; A second covering part that is continuous with the first covering part and covers the portion of the flow path member facing the pressure chamber, and a third covering part that is continuous with the second covering part and covers the surface of the flow path member facing the injection hole plate in the second direction, and a second protection part that is superposed on the first protection part on the drive part, the head chip according to any one of claims 1 to 4, comprising the same.

9. The head chip according to any one of claims 1 to 4, wherein the softening point of the protective film is set to 120°C or lower.

10. The head chip according to any one of claims 1 to 4, wherein the protective film is formed of a thermoplastic resin.

11. A liquid injection head including the head chip according to any one of claims 1 to 4.

12. A liquid injection recording apparatus including the liquid injection head according to claim 11.

13. A flow path member in which a plurality of pressure chambers for storing liquid are formed side by side in a first direction; An actuator plate that is disposed on the flow path member in a state facing the pressure chamber in a second direction intersecting the first direction, and having the second direction as a polarization direction; Drive wirings respectively formed on a flow path facing surface facing the flow path member in a drive part of the actuator plate that overlaps the pressure chamber when viewed from the second direction; A manufacturing method of a head chip including a sheet-like protective film that covers the drive wiring on the flow path facing surface of the drive part and partitions between the pressure chamber and the drive part, The manufacturing method of a head chip including a protective film forming step of covering the drive part with the protective film by closely adhering it on the drive part.

14. The manufacturing method of the head chip according to claim 13, wherein the protective film forming step makes the first space located on the actuator plate side with respect to the protective film negative pressure with respect to the second space located on the side opposite to the actuator plate with respect to the protective film in a chamber in which the actuator plate and the protective film are set, thereby closely adhering the protective film on the drive part.

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