Head chip, liquid jet head, liquid jet recording apparatus, and method of manufacturing head chip

Abstract

To provide a head chip which achieves uniformalization of discharge performance and is excellent in merchantability, and to provide a liquid jet head, a liquid jet recording device, and a manufacturing method of the head chip.SOLUTION: In a head chip 50 according to one embodiment of the disclosure, an inner surface of a discharge channel 61 is provided with: a first low dielectric film 118a provided at a lower end part; a second low dielectric film 118b provided at an upper end part; and a first common electrode part 123a which is provided ranging from the upper end part to the lower end part and covers the first low dielectric film 118a and the second low dielectric film 118b.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] The head chip mounted on an inkjet printer is constructed by stacking a cover plate and a nozzle plate on an actuator plate with multiple channels. The cover plate has ink flow paths formed on the upstream side of the channels that communicate with the channels. The nozzle plate has nozzle holes formed on the downstream side of the channels that communicate with the channels. Electrodes are formed on the partition walls of the actuator plate that separate each channel. To eject ink from the head chip, a voltage is applied between the electrodes, creating an electric field across the partition walls, causing the partition walls to slide and deform. This changes the volume within the channels, causing the ink in the channels to be ejected through the nozzle holes.

[0003] It is known that head chips generate heat due to increased power consumption and capacitance during operation. When a head chip generates heat, variations in ink viscosity and other factors are likely to occur, which may affect ejection performance. Therefore, for example, Patent Document 1 listed below discloses a configuration in which a low-dielectric film is interposed between a partition wall and an electrode at the upstream end of the channel (the portion communicating with the ink flow path). With this configuration, it is said that heat generation by the head chip can be suppressed by making it difficult for an electric field to be applied to the portion of the partition wall where the low-dielectric film is interposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 97 / 39897 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional head chips, dimensional variations in the low-dielectric film between channels were likely to occur. When dimensional variations in the low-dielectric film occur, the dimensions of the portion of the electrode that directly contacts the partition wall and the portion that contacts the partition wall via the low-dielectric film differ between channels. As a result, in conventional head chips, variations in ejection performance (output) were likely to occur between different channels in the same chip or between multiple chips.

[0006] The present disclosure provides a head chip, a liquid jet head, a liquid jet recording apparatus, and a method for manufacturing the head chip, which are superior in marketability and aim to achieve uniformity in ejection performance. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure employs the following aspects. (1) A head chip according to one aspect of the present disclosure includes an actuator plate having ejection channels extending in a first direction and spaced apart in a second direction intersecting the first direction, the actuator plate having an end face at which a first side end of the ejection channel in the first direction opens, and an ejection hole plate having ejection holes communicating with the ejection channel and arranged opposite the end face, wherein the inner surface of the ejection channel is provided with a first low dielectric film arranged at the first side end in the first direction, a second low dielectric film arranged at the second side end in the first direction, and a first electrode portion arranged from the first side end to the second side end in the first direction, covering the first low dielectric film and the second low dielectric film.

[0008] According to this aspect, when forming the first and second low-dielectric films on both ends of the ejection channel, a first mask having mask openings corresponding to the regions of the ejection channel where the first and second low-dielectric films are formed and a covering portion corresponding to the region where the low-dielectric films are not formed is disposed, for example. In this case, the region where the low-dielectric films are formed can be used as a tolerance for misalignment of the covering portions. That is, compared to a case where the covering portions are aligned at either end of the ejection channel, such as when the low-dielectric films are provided only at either end of the ejection channel in the first direction, the dimensions of the region where the low-dielectric films are not formed are more likely to be uniform between the ejection channels even when the covering portions are misaligned. As a result, variation in ejection performance between the ejection channels can be suppressed.

[0009] (2) In the head chip according to the above aspect (1), it is preferable that the distance between the first low dielectric film and the second low dielectric film in the first direction is constant among the plurality of ejection channels. According to this aspect, the portion of the first electrode portion located between the first low dielectric film and the second low dielectric film is in direct contact with the inner surface of the ejection channel and functions as a drive region that contributes to driving the actuator plate. In this aspect, the dimensions of the drive region are uniform among the ejection channels, so that variation in ejection performance among the ejection channels can be suppressed.

[0010] (3) In the head chip according to the above aspect (1) or (2), a cover plate is provided which has a liquid flow path which is connected to the ejection channel at a second side end in the first direction, and which is arranged facing the actuator plate in a thickness direction which intersects with the second direction as viewed from the first direction, and the ejection channel has a communication portion which overlaps with the liquid flow path as viewed from the thickness direction, and a pump portion which is arranged on a first side in the first direction relative to the communication portion, and in the first direction, it is preferable that the distance between the first low dielectric film and the second low dielectric film is shorter than the length of the pump portion. According to this aspect, since the driving region can be easily arranged in the pump section, the pump section can be driven efficiently and the discharge performance can be maintained.

[0011] (4) In the head chip according to the aspect (3) above, it is preferable that the first low dielectric film is located in the pump portion, and a portion of the second low dielectric film is located on the first side in the first direction relative to the boundary portion between the pump portion and the communication portion. According to this aspect, the drive region is reliably positioned in the pump section regardless of misalignment of the first low dielectric film and the second low dielectric film, which offsets the influence of misalignment of the first mask for forming the low dielectric film and makes it easier to maintain constant ejection performance between the ejection channels.

[0012] (5) In the head chip according to the aspect (3) above, it is preferable that the first low dielectric film is located in the pump portion, and the entire second low dielectric film is located on the second side in the first direction relative to the boundary between the pump portion and the communication portion. According to this aspect, even if a portion of the driving region is positioned off-center from the pump section due to misalignment of the first mask, the dimensions of the driving region remain constant. In this case, a portion of the first electrode portion located on the second side of the boundary between the pump section and the communication section (hereinafter referred to as the "protruding portion") directly contacts the inner surface of the ejection channel. Therefore, the protruding portion can contribute to driving the ejection channel to a significant extent. This makes it possible to suppress a decrease in ejection performance compared to a configuration in which the driving region is contained within the pump section when the entire second low dielectric film is located in the communication section. In other words, the impact on ejection performance caused by misalignment of the first mask used to form the low dielectric film can be reduced as much as possible.

[0013] (6) In a head chip according to any one of the above aspects (3) to (5), it is preferable that the actuator plate has a tail portion located on a second side in the first direction relative to the ejection channel, and the first electrode portion is located on the first side in the thickness direction on the inner surface of the ejection channel, is provided on a main surface of the tail portion facing the first side in the thickness direction, and is connected to the first electrode portion at the opening edge of the ejection channel, and is provided with a second electrode portion located on the second side in the thickness direction on the inner surface of the ejection channel, inside the first side end and second side end in the first direction, and is connected to the first electrode portion on the inner surface of the ejection channel. According to this aspect, on the second side in the thickness direction of the inner surface of the ejection channel, the first side end in the first direction constitutes a first non-forming region where the second electrode portion is not formed, and the second side end in the first direction constitutes a second non-forming region where the second electrode portion is not formed. When the first non-forming region and the second non-forming region are formed, for example, using a second mask, a covering portion is disposed corresponding to the non-forming region (both ends in the first direction) of the ejection channel, and a mask opening is disposed corresponding to the forming region of the second electrode portion. In this case, the non-forming region can be used as an allowance for allowing misalignment of the covering portion. That is, even if the second mask is misaligned in the first direction from the desired position, dimensional variation of the second electrode portion can be suppressed. This makes it easier to align the dimensions of the second electrode portion between the ejection channels when the covering portion is misaligned, compared to when only the second side end of the ejection channel is the non-forming region of the second electrode portion. As a result, variation in ejection performance between the ejection channels can be suppressed.

[0014] (7) In the head chip according to the above aspect (6), it is preferable that the dimension of the second electrode portion in the first direction is constant among the plurality of ejection channels. According to this aspect, it is possible to suppress variations in ejection performance between the ejection channels.

[0015] (8) In the head chip according to the above aspect (6) or (7), it is preferable that, on the second side in the thickness direction of the inner surface of the ejection channel, a first side end in the first direction constitutes a first non-forming region in which the second electrode portion is not formed, and, on the second side in the thickness direction of the inner surface of the ejection channel, a second side end in the first direction constitutes a second non-forming region in which the second electrode portion is not formed, the first non-forming region is located in the pump portion, and a part of the second non-forming region is located on the first side in the first direction of the boundary portion between the pump portion and the communicating portion. According to this aspect, the second electrode portion is reliably disposed in the pump portion, so that the pump portion can be driven efficiently and the ejection performance can be maintained.

[0016] (9) In the head chip according to the above aspect (6) or (7), it is preferable that, on the second side in the thickness direction of the inner surface of the ejection channel, a first side end in the first direction constitutes a first non-forming region in which the second electrode portion is not formed, and, on the second side in the thickness direction of the inner surface of the ejection channel, a second side end in the first direction constitutes a second non-forming region in which the second electrode portion is not formed, the first non-forming region is located in the pump portion, and the entire second non-forming region is located on the second side in the first direction of the boundary portion between the pump portion and the communication portion. According to this aspect, the portion of the second electrode portion located on the second side of the boundary between the pump portion and the communication portion (hereinafter referred to as the protruding portion) can be made to contribute to driving the ejection channel to a considerable extent. This makes it possible to suppress a decrease in ejection performance compared to a configuration in which the second electrode portion is contained within the pump portion. In other words, it is possible to reduce as much as possible the impact on ejection performance caused by misalignment of the second mask for forming a low-dielectric film.

[0017] (10) A liquid jet head according to one aspect of the present disclosure includes the head chip according to any one of the above aspects (1) to (9). According to this aspect, it is possible to provide a liquid jet head with excellent marketability by achieving uniformity in jetting performance between each jetting channel in the same head chip or between multiple head chips.

[0018] (11) A liquid jet recording apparatus according to one aspect of the present disclosure includes the liquid jet head according to the above aspect (10). According to this aspect, it is possible to provide a liquid jet recording apparatus with excellent market value by achieving uniformity in jetting performance between each jetting channel in the same head chip or between a plurality of head chips.

[0019] (12) A method for manufacturing a head chip according to one aspect of the present disclosure includes: a low dielectric film forming process for forming a low dielectric film on the inner surface of an actuator plate having ejection channels extending in a first direction and spaced apart in a second direction intersecting the first direction, via a first mask; an electrode forming process for forming an electrode on the inner surface of the ejection channel so as to cover the low dielectric film; and a lamination process for overlapping a cover plate having a liquid flow path communicating with the inside of the ejection channel on the actuator plate in a thickness direction intersecting the second direction as viewed from the first direction, The injection channel includes a communication portion that overlaps the liquid flow path when viewed from the thickness direction, and a pump portion that is provided on a first side in the first direction of the communication portion, and the first mask has a first mask opening and a second mask opening whose spacing in the first direction is set to be shorter than the dimension of the pump portion in the first direction, and in the low dielectric film formation process, a material for forming the low dielectric film is introduced into the injection channel through the first mask opening and the second mask opening with a covering portion of the first mask located between the first mask opening and the second mask opening superimposed on the pump portion.

[0020] According to this aspect, in the low-dielectric film forming process, the first mask opening and the second mask opening (the low-dielectric film forming area) can be used as a tolerance for misalignment of the covering portion. That is, compared to a case where the covering portion is aligned at one end of the ejection channel, such as when the low-dielectric film is provided only at one end of the ejection channel in the first direction, the dimensions of the non-forming area of ​​the low-dielectric film are more likely to be uniform between the ejection channels even when the covering portion is misaligned. As a result, it is possible to suppress variations in the ejection performance between the ejection channels.

[0021] (13) In the method for manufacturing a head chip according to the aspect (12) above, the actuator plate has a tail portion located on a second side in the first direction relative to the ejection channel, and the electrode formation process includes a first process of introducing a material for forming the electrode into the ejection channel from the first side in the thickness direction, and a second process of introducing a material for forming the electrode into the ejection channel from the second side in the thickness direction through a second mask, wherein in the first process, the electrode is formed so as to cover the low dielectric film on the inner surface of the ejection channel, and a terminal connected to the electrode is formed on a main surface of the tail portion facing the first side in the thickness direction, and a third mask opening is formed in the second mask, the spacing in the second direction being set shorter than the dimension of the pump portion in the first direction, and it is preferable that in the second process, the material for forming the electrode is introduced into the ejection channel through the third mask opening while the third mask opening is superimposed on the pump portion. According to this aspect, in the second step, the portions of the second mask located on both sides of the third mask opening (non-forming regions) can be used as tolerances to allow for misalignment of the third mask opening. In other words, even if the second mask is misaligned in the first direction relative to the desired position, dimensional variations in the second electrode portion can be suppressed. This makes it easier to align the dimensions of the second electrode portion between each ejection channel when the covering portion is misaligned, compared to when only the second side end of the ejection channel is the non-forming region of the second electrode portion. As a result, variations in ejection performance between each ejection channel can be suppressed. [Effects of the Invention]

[0022] According to one aspect of the present disclosure, it is possible to provide a head chip, a liquid jet head, a liquid jet recording apparatus, and a method for manufacturing a head chip that are superior in marketability and that achieve uniformity in ejection performance. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram illustrating the configuration of an inkjet printer according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of a head chip according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view corresponding to line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view corresponding to the line IV-IV in FIG. 2. [Figure 5] FIG. 3 is a cross-sectional view corresponding to the line VV in FIG. [Figure 6] 6 is a cross-sectional view corresponding to the line VI-VI in FIG. 2. [Figure 7] 10 is a flowchart illustrating a method for manufacturing a head chip according to an embodiment. [Figure 8] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 9] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 10] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 11] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 12] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 13] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 14] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 15] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 16] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 17] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 18] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 19] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 20] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 21] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 22] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 23] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 24] 5A to 5C are process diagrams illustrating a method for manufacturing a head chip according to an embodiment. [Figure 25] FIG. 2 is a cross-sectional view of the head chip, illustrating the operation of the head chip according to the embodiment. [Figure 26] FIG. 2 is a cross-sectional view of the head chip, illustrating the operation of the head chip according to the embodiment. [Figure 27] FIG. 2 is a cross-sectional view of the head chip, illustrating the operation of the head chip according to the embodiment. [Figure 28] FIG. 2 is a cross-sectional view of the head chip, illustrating the operation of the head chip according to the embodiment. [Figure 29] FIG. 10 is a cross-sectional view of a head chip according to a first modified example. [Figure 30] FIG. 10 is a cross-sectional view of a head chip according to a second modified example. [Figure 31] FIG. 10 is a cross-sectional view of a head chip according to a third modified example. [Figure 32] FIG. 10 is a cross-sectional view of a head chip according to a third modified example. [Figure 33] FIG. 1 is a cross-sectional view of a head chip according to the prior art. [Figure 34] FIG. 1 is a cross-sectional view of a head chip according to the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the embodiments and modified examples described below, corresponding components may be designated by the same reference numerals, and their description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly refer to such arrangements, but also refer to a state in which there is a relative displacement with a tolerance or an angle or distance that provides the same function. In the following embodiment, an inkjet printer (hereinafter simply referred to as a printer) that records on a recording medium using ink (liquid) will be described as an example. In the drawings used in the following description, the scale of each component has been appropriately changed to make each component recognizable.

[0025] [Printer 1] FIG. 1 is a schematic diagram of the printer 1. As shown in FIG. 1, the printer (liquid jet recording apparatus) 1 of the first embodiment includes a pair of transport mechanisms 2 and 3, an ink supply mechanism 4, an inkjet head (liquid jet head) 5, and a scanning mechanism 6.

[0026] In the following explanation, an X, Y, Z Cartesian coordinate system will be used as necessary. In this case, the X direction corresponds to the transport direction (sub-scanning direction) of the recording medium P (e.g., paper, etc.). The Y direction corresponds to the scanning direction (main scanning direction) of the scanning mechanism 6. The Z direction indicates the height direction (gravity direction) perpendicular to the X and Y directions. In the following explanation, of the X, Y, and Z directions, the arrow side in the figure is the plus (+) side, and the opposite side to the arrow is the minus (-) side. In this specification, the +Z side corresponds to the upward direction in the direction of gravity, and the -Z side corresponds to the downward direction in the direction of gravity.

[0027] 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 supply mechanism 4 includes ink tanks 15 containing ink, and ink pipes 16 connecting the ink tanks 15 to the inkjet heads 5. The ink tanks 15 contain ink of four colors, for example, yellow, magenta, cyan, and black. Each inkjet head 5 is configured to be able to eject ink of one of the four colors, yellow, magenta, cyan, or black, depending on the ink tank 15 connected to it.

[0028] The scanning mechanism 6 causes the inkjet head 5 to scan back and forth in the Y direction. The scanning mechanism 6 includes a guide rail 22 and a carriage 23 supported by the guide rail 22 so as to be movable in the Y direction. During a printing operation on the recording medium P, the inkjet head 5 moves back and forth in the Y direction while mounted on the carriage 23.

[0029] <Inkjet head 5> 1, the inkjet heads 5 are mounted side by side in the Y direction on one carriage 23. The inkjet head 5 includes a head chip 50 (see FIG. 2), an ink supply unit (not shown) that connects the ink tank 15 and the head chip 50, and a control unit (not shown) that applies a drive voltage to the head chip 50.

[0030] <Head chip 50> FIG. 2 is an exploded perspective view of the head chip 50. As shown in FIG. 2 is a so-called edge shoot type head chip 50 that ejects ink from the end of an ejection channel 61 (described later) in the extension direction (Z direction). The head chip 50 includes a nozzle plate 51 (see FIG. 3, etc.), an actuator plate 53, and a cover plate 54.

[0031] The actuator plate 53 has a configuration in which a main plate 55 and a back plate 56 are stacked in the Y direction. The main plate 55 and the back plate 56 are made of a piezoelectric material such as PZT (lead zirconate titanate). The main plate 55 has a configuration in which, for example, two piezoelectric plates having different polarization directions in the Y direction are stacked (a so-called chevron type). As long as at least the main plate 55 of the actuator plate 53 is made of a piezoelectric material, the back plate 56 may be made of a material other than a piezoelectric material.

[0032] The actuator plate 53 is formed with ejection channels (ejection channels) 61 that are filled with ink and non-ejection channels (non-ejection channels) 62 that are not filled with ink. The channels 61, 62 are arranged alternately at intervals in the X direction (second direction) on the actuator plate 53. In this embodiment, a configuration will be described in which the channel extension direction coincides with the Z direction (first direction), but the channel extension direction may also intersect with the Z direction.

[0033] Fig. 3 is a cross-sectional view corresponding to line III-III in Fig. 2. In the following description, the +Y side (first side) is the front surface (main surface) side, the -Y side (second side) is the back surface side, the +Z side is the upper side (second side), and the -Z side is the lower side (first side). 3, the discharge channel 61 opens on the surface of the actuator plate 53 and extends in the Z direction. The discharge channel 61 includes an extending portion 61a and a cut-up portion 61b. The extension portion 61a is a portion with a uniform depth in the Y direction. The lower end (first side end) of the extension portion 61a is open at the lower end surface (first side end surface) of the actuator plate 53. In this embodiment, the extension portion 61a penetrates the main plate 55 in the Y direction. Therefore, the bottom surface of the extension portion 61a is formed by the surface of the back plate 56.

[0034] The raised portion 61b is continuous with the upper end of the extending portion 61a. The depth of the raised portion 61b in the Y direction gradually decreases as it extends upward. Specifically, the bottom surface of the raised portion 61b is formed as an inclined surface that curves and extends toward the surface side as it extends upward.

[0035] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 4, the non-ejection channels 62 open on the surface of the actuator plate 53 and penetrate the actuator plate 53 in the Z direction. The non-ejection channels 62 have a uniform depth in the Y direction over their entire length in the Z direction. The non-ejection channels 62 penetrate the main plate 55 in the Y direction. Therefore, the bottom surfaces of the non-ejection channels 62 are formed by the surface of the back plate 56.

[0036] As shown in FIG. 2, the portions of the actuator plate 53 located between the discharge channel 61 and the non-discharge channel 62 each constitute a drive wall 65. Therefore, the discharge channel 61 is surrounded on both sides in the X direction by a pair of drive walls 65. The portion of the actuator plate 53 located above the discharge channel 61 constitutes a tail portion 78. A partition groove 79 is formed in the tail portion 78. The partition groove 79 extends in the X direction on the surface of the tail portion 78, bridging the gap between adjacent non-discharge channels 62.

[0037] <Cover plate 54> As shown in FIGS. 2 to 4, the cover plate 54 is fixed to the surface of the actuator plate 53 by adhesive or the like. Specifically, the cover plate 54 is disposed with its thickness direction aligned in the Y direction. The cover plate 54 closes the openings on the surface side of each of the channels 61, 62, with the surface of the tail portion 78 exposed. In the Z direction, the lower end surface of the cover plate 54 is disposed flush with the lower end surface of the actuator plate 53.

[0038] An inlet common ink chamber 90 is formed in the cover plate 54 at a position overlapping the upper end of the ejection channel 61 when viewed from the Y direction. The inlet common ink chamber 90 extends in the X direction, for example, to a length spanning each of the channels 61 and 62, and opens on the surface of the cover plate 54. In the inlet shared ink chamber 90, an inlet slit (liquid flow path) 91 is formed at a position overlapping with the ejection channel 61 when viewed from the Y direction. The inlet slit 91 individually connects the upper end of each ejection channel 61 to the inside of the inlet shared ink chamber 90. The inlet slit 91 faces the cut-up portion 61b in the Y direction. Therefore, the inlet slit 91 communicates with each ejection channel 61, but does not communicate with each non-ejection channel 62.

[0039] As shown in FIGS. 3 and 4 , the region of discharge channel 61 below inlet slit 91 and covered by cover plate 54 constitutes pump section 100. When head chip 50 is driven, pump section 100 is a region where drive wall 65 is likely to deform in the X direction because the cover plate 54 restricts deformation of drive wall 65 in the Y direction. Meanwhile, the region of discharge channel 61 that is connected to inlet slit 91 (the region not covered by cover plate 54) constitutes communicating section 101. In the illustrated example, the boundary between pump section 100 and communicating section 101 is located below the boundary between extension section 61a and raised section 61b. However, the boundary between pump section 100 and communicating section 101 may coincide with the boundary between extension section 61a and raised section 61b in the Z direction, or may be located above the boundary between extension section 61a and raised section 61b.

[0040] The nozzle plate 51 is fixed to the lower end surface of the actuator plate 53 by adhesive or the like. The nozzle plate 51 is disposed with its thickness direction in the Z direction and its longitudinal direction in the X direction. In this embodiment, the nozzle plate 51 is formed of a resin material such as polyimide to a thickness of approximately 50 μm. However, the nozzle plate 51 may have a single-layer structure or a multi-layer structure made of a metal material (such as SUS or Ni-Pd), glass, silicon, or the like, in addition to the resin material. The nozzle plate 51 may be fixed directly to the lower end surface of the actuator plate 53, or may be fixed indirectly via, for example, an intermediate plate or the like.

[0041] The nozzle plate (injection hole plate) 51 is formed with the above-mentioned nozzle holes (injection holes) 102 that penetrate the nozzle plate 51 in the Z direction. The nozzle holes 102 are individually formed in the nozzle plate 51 at positions that face the ejection channels 61 in the Z direction. Each nozzle hole 102 is formed in a tapered shape that gradually narrows from top to bottom.

[0042] Next, the wiring structure of the actuator plate 53 will be described. The actuator plate 53 is provided with a low dielectric film 110, common wiring 111, and individual wiring 112. The low dielectric film 110 is a thin film made of a material with a low dielectric constant (e.g., SiO2, etc.). The low dielectric film 110 includes an ejection-side film 115 formed on the inner surface of the ejection channel 61, a non-ejection-side film 116 formed on the inner surface of the non-ejection channel 62, and a tail-side film 117 formed on the surface of the tail 78.

[0043] The discharge-side film 115 is formed at least in a range on the +Y side including the center in the Y direction within the discharge channel 61. The discharge-side film 115 includes inner surface portions 118 formed on both inner surfaces of the inner surface of the discharge channel 61 that face each other in the X direction, and a bottom surface portion 119 formed on the bottom surface of the cut-up portion 61b.

[0044] FIG. 5 is a cross-sectional view taken along line VV in FIG. As shown in FIGS. 3 and 5, the inner surface portion 118 includes a first low dielectric film 118a and a second low dielectric film 118b provided on the same inner surface of the ejection channel 61 and spaced apart in the Z direction. The first low dielectric film 118a is formed on the lower end of the pump section 100. The lower end of the first low dielectric film 118a coincides with the lower end of the discharge channel 61.

[0045] 3, the second low dielectric film 118b is provided on the upper end (second side end) of the inner surface of the discharge channel 61. The second low dielectric film 118b is provided across the boundary between the pump section 100 and the communication section 101 in the Z direction. In this embodiment, the second low dielectric film 118b is continuously formed over the entire communication section 101 and the upper end of the pump section 100.

[0046] The dimension D1 in the Z direction of the first low dielectric film 118a is equal to the dimension D2 in the Z direction of the portion of the second low dielectric film 118b located in the pump section 100. However, the dimension D1 of the first low dielectric film 118a and the dimension D2 of the second low dielectric film 118b may be different from each other (see FIGS. 25, 26, etc.). Note that the discharge-side film 115 only needs to have at least the inner side surface portion 118, and may not have the bottom surface portion 119.

[0047] 4 and 5, the non-ejection side film 116 is formed at least in the range on the +Y side including the center in the Y direction within the non-ejection channel 62. The non-ejection side film 116 is formed on both inner surfaces of the non-ejection channel 62 that face each other in the X direction.

[0048] The non-ejection side film 116 includes a third low dielectric film 116a and a fourth low dielectric film 116b that are provided on the same inner side surface of the non-ejection channel 62 and spaced apart in the Z direction. The third low dielectric film 116a is formed facing the first low dielectric film 118a at the lower end of the non-ejection channel 62. The lower end of the third low dielectric film 116a coincides with the lower end of the non-ejection channel 62. The fourth low dielectric film 116b is provided on the upper part of the inner surface of the non-ejection channel 62. Specifically, the lower end of the fourth low dielectric film 116b is provided opposite the first low dielectric film 118a in the X direction. The upper end of the fourth low dielectric film 116b extends upward beyond the cut-up portion 61b. In the illustrated example, the upper end of the fourth low dielectric film 116b reaches the partitioning groove 79 in the Z direction.

[0049] 3, the tail-side membrane 117 is formed on a portion of the surface of the tail portion 78 that is located below the partitioning groove 79. The tail-side membrane 117 extends in the same straight line as the discharge channel 61 on the surface of the tail portion 78. The lower edge of the tail-side membrane 117 is continuous with the upper edge of the bottom portion 119 at the opening edge on the surface side of the discharge channel 61.

[0050] The common wiring 111 includes a common electrode (electrode) 120 and a common terminal (terminal portion) 121. The common electrode 120 is formed on the inner surface of the ejection channel 61. Specifically, the common electrode 120 includes a side electrode 123 and a bottom electrode .

[0051] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 3, 5, and 6, the side electrodes 123 are formed on the inner surfaces of the ejection channel 61 that face each other in the X direction. The side electrodes 123 include a first common electrode portion (first electrode portion) 123a formed in a range on the +Y side including the center in the Y direction within the ejection channel 61, and a second common electrode portion (second electrode portion) 123b formed in a range on the -Y side including the center in the Y direction within the ejection channel 61. The first common electrode portion 123a and the second common electrode portion 123b overlap at the center in the Y direction within the ejection channel 61.

[0052] The first common electrode portion 123a is formed over the entire area in the Z direction on the inner surface of the ejection channel 61. That is, the first common electrode portion 123a covers the first low dielectric film 118a and the second low dielectric film 118b separately at both ends in the Z direction. Both ends of the first common electrode portion 123a in the Z direction are disposed on the inner surface of the ejection channel 61 via the first low dielectric film 118a and the second low dielectric film 118b (see FIG. 5). Meanwhile, the portion of the first common electrode portion 123a located between the first low dielectric film 118a and the second low dielectric film 118b is in direct contact with the inner surface of the ejection channel 61 (see FIG. 6).

[0053] The area of ​​the first common electrode portion 123a that is in direct contact with the inner surface of the ejection channel 61 is referred to as the common driving region 125. The common driving region 125 is constant between each ejection channel 61. The dimension D3 in the Z direction of the common driving region 125 is smaller than the dimension D0 of the pump portion 100. It is preferable that the dimension D3 of the common driving region 125 is approximately 10% to 20% shorter than the dimension D0 of the pump portion 100. In the illustrated example, the entire area of ​​the common driving region 125 is provided within the range of the pump portion 100. However, as long as an electric field can be applied to the driving wall 65, a conductive material may be interposed between the first common electrode portion 123a located in the common driving region 125 and the inner surface of the ejection channel 61.

[0054] The second common electrode portion 123b is formed in a region (region excluding both ends in the Z direction) on the inner surface of the ejection channel 61 that is located inside the both ends in the Z direction. That is, on the inner surface of the ejection channel 61, a portion that is located below the second common electrode portion 123b constitutes a first non-formation region 128a where the second common electrode portion 123b is not formed. On the inner surface of the ejection channel 61, a portion that is located above the second common electrode portion 123b constitutes a second non-formation region 128b where the second common electrode portion 123b is not formed.

[0055] The dimension D4 in the Z direction of the second common electrode portion 123b is equal to the dimension D3 of the common driving region 125. In the example shown, the second common electrode portion 123b and the common driving region 125 entirely overlap in the Z direction. However, the dimension D4 in the Z direction of the second common electrode portion 123b and the dimension D3 of the common driving region 125 may be different. Furthermore, the second common electrode portion 123b and the common driving region 125 may be arranged with a partial offset in the Z direction (see FIGS. 25 to 29, etc.).

[0056] 2 and 3, the common terminal 121 is disposed on the surface of the tail 78 via the tail-side membrane 117. The common terminal 121 is formed in a strip shape extending in the Z direction on the surface of the tail 78. The common terminal 121 is connected to the common electrode 120 (bottom electrode 124) at the edge of the opening on the front surface side of the ejection channel 61.

[0057] As shown in FIGS. 4 to 6, the individual wiring 112 includes an individual electrode 130 and an individual terminal 131. The individual electrodes 130 are formed on the inner surfaces of the driving walls 65 that face the non-ejection channels 62. The individual electrodes 130 formed on opposing inner surfaces of the inner surfaces of the non-ejection channels 62 are separated by the bottom surfaces of the non-ejection channels 62. The individual electrodes 130 include a first individual electrode portion 130a formed in a range on the +Y side including the center in the Y direction within the non-ejection channels 62, and a second individual electrode portion 130b formed in a range on the -Y side including the center in the Y direction within the non-ejection channels 62. The first individual electrode portion 130a and the second individual electrode portion 130b overlap at the center in the Y direction within the non-ejection channels 62.

[0058] The first individual electrode portion 130a is formed over the entire area in the Z direction on the inner surface of the non-ejection channel 62. That is, the first individual electrode portion 130a covers the third low dielectric film 116a and the fourth low dielectric film 116b at both ends in the Z direction. In the first individual electrode portion 130a, both ends in the Z direction are disposed on the inner surface of the non-ejection channel 62 via the third low dielectric film 116a and the fourth low dielectric film 116b. On the other hand, the portion of the first individual electrode portion 130a located between the third low dielectric film 116a and the fourth low dielectric film 116b is in direct contact with the inner surface of the non-ejection channel 62.

[0059] The area of ​​the first individual electrode portion 130a that is in direct contact with the inner surface of the non-ejection channel 62 is referred to as the individual drive region 135. A dimension D5 in the Z direction of the individual drive region 135 is smaller than a dimension D0 of the pump portion 100. In the example shown, the entire area of ​​the individual drive region 135 is provided within the range of the pump portion 100. However, as long as an electric field can be applied to the drive wall 65, a conductive material may be interposed between the first individual electrode portion 130a located in the individual drive region 135 and the inner surface of the non-ejection channel 62.

[0060] The second individual electrode portion 130b is formed in a region (region excluding both ends in the Z direction) on the inner surface of the non-ejection channel 62 that is located inside the both ends in the Z direction. That is, on the inner surface of the non-ejection channel 62, a portion located below the second individual electrode portion 130b constitutes a third non-formation region 138a where the second individual electrode portion 130b is not formed. On the inner surface of the non-ejection channel 62, a portion located above the second individual electrode portion 130b constitutes a fourth non-formation region 138b where the second individual electrode portion 130b is not formed. It is preferable that the fourth non-formation region 138b extend above the ejection channel 61. In the illustrated example, the fourth non-formation region 138b reaches the upper end of the non-ejection channel 62.

[0061] The dimension D6 in the Z direction of the second individual electrode unit 130b is equal to the dimension D5 of the individual drive area 135. In the example shown, the second individual electrode unit 130b and the individual drive area 135 entirely overlap in the Z direction. However, the dimension D6 in the Z direction of the second individual electrode unit 130b and the dimension D5 of the individual drive area 135 may be different. Furthermore, the second individual electrode unit 130b and the individual drive area 135 may be arranged with a partial offset in the Z direction.

[0062] 3 and 4, it is preferable that the first common electrode portion 123a (common driving area 125) and the first individual electrode portion 130a facing each other across the driving wall 65 have the same Z-direction dimensions D3 and D5, respectively, and that they entirely overlap in the Z direction as viewed from the X direction. However, the dimension D3 of the common driving area 125 and the dimension D5 of the first individual electrode portion 130a may be different from each other. Furthermore, the first common electrode portion 123a and the first individual electrode portion 130a may be partially misaligned as viewed from the X direction.

[0063] It is preferable that the second common electrode portion 123b and the second individual electrode portion 130b facing each other across the driving wall 65 have the same Z-direction dimensions D4 and D6 and overlap entirely in the Z direction as viewed in the X direction. However, the dimension D4 of the second common electrode portion 123b and the dimension D6 of the second individual electrode portion 130b may be different from each other. Furthermore, the second common electrode portion 123b and the second individual electrode portion 130b may be partially misaligned as viewed in the X direction.

[0064] 2, the individual terminal 131 is formed on the surface of the tail portion 78 at a portion located above the common terminal 121. The individual terminal 131 has a strip shape extending in the X direction. The individual terminal 131 connects the individual electrodes 130 (first individual electrode portions 130a) that face each other in the X direction with the ejection channel 61 therebetween at the front-side opening edges of the non-ejection channels 62 that face each other in the X direction with the ejection channel 61 therebetween. The individual terminal 131 and the common terminal 121 are separated by a partition groove 79.

[0065] 3 and 4, a flexible printed circuit board 139 is crimped onto the surface of the tail portion 78. The flexible printed circuit board 139 is connected to the common terminal 121 and the individual terminals 131 on the surface of the tail portion 78. The flexible printed circuit board 139 is drawn out upward.

[0066] [Printer 1 operation method] Next, a case where characters, figures, etc. are recorded on the recording medium P using the printer 1 configured as described above will be described below. 1 are initially filled with ink of different colors. The ink in the ink tanks 15 is then supplied to the inkjet head 5 via the ink pipes 16.

[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 rollers 11 and 12 of the conveyance mechanisms 2 and 3. At the same time, the carriage 23 moves in the Y direction, causing the inkjet head 5 mounted on the carriage 23 to move back and forth in the Y direction. While the inkjet heads 5 are reciprocating, ink is ejected appropriately 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] When the inkjet head 5 begins to move back and forth due to the movement of the carriage 23 (see FIG. 1), a drive voltage is applied between the common electrode 120 and the individual electrode 130 via the flexible printed circuit board 139. At this time, the drive voltage is applied between the electrodes 120, 130 with the individual electrode 130 at drive potential Vdd and the common electrode 120 at reference potential GND. This causes thickness slip deformation in the drive wall 65 due to the so-called inverse piezoelectric effect, resulting in a V-shaped bending deformation starting from the center in the Y direction. In other words, the drive wall 65 deforms so as to expand the volume of the ejection channel 61.

[0069] After the volume of each ejection channel 61 has increased, the voltage applied between the common electrode 120 and the individual electrode 130 is set to zero. This causes the drive wall 65 to return to its original state, and the volume of the ejection channel 61, which had once increased, returns to its original volume. This increases the pressure inside the ejection channel 61, pressurizing the ink. A pressure wave generated by the increased pressure inside the ejection channel 61 then propagates toward the nozzle hole 102. As a result, the ink inside the ejection channel 61 is ejected in the form of droplets through the nozzle hole 102. The ink ejected from the nozzle hole 102 lands on the recording medium P, allowing characters, images, and the like to be recorded on the recording medium P.

[0070] <Method of manufacturing the head chip 50> Next, a method for manufacturing the above-mentioned head chip 50 will be described. Fig. 7 is a flowchart for explaining the method for manufacturing head chip 50. Figs. 8 to 10 are plan views of main wafer 200, showing steps for explaining the method for manufacturing head chip 50. Figs. 11 to 24 are plan views of main wafer 200, showing steps for explaining the method for manufacturing head chip 50, with Figs. 11 to 18 being cross-sectional views corresponding to line AA in Fig. 8 and Figs. 19 to 24 being cross-sectional views corresponding to line BB in Fig. 8. In this embodiment, a method for manufacturing a plurality of head chips 50 collectively at wafer level will be described. As shown in FIG. 7, the head chip 50 is manufactured through, for example, a pattern forming process, a first dicing process, a second dicing process, a low dielectric film forming process, a first wiring forming process (first process), a third dicing process, a cover wafer laminating process (laminating process), a grinding process, a second wiring forming process (second process), a back wafer laminating process, a singulation process, and a nozzle plate laminating process.

[0071] First, in the pattern formation step, a mask pattern (not shown) to be used in the first electrode formation step is formed. Specifically, a mask material such as a photosensitive dry film is attached to the surface of the main wafer 200 (see FIG. 8), which will later become the main plate 55. Thereafter, the mask material is patterned using photolithography technology to remove the mask material from the portions of the mask material that are located in the formation regions of the common wiring 111 and the individual wiring 112 (see FIG. 4). As a result, a mask pattern is formed on the surface of the main wafer 200, with openings at least in the formation regions of the common terminals 121 and the individual terminals 131. The mask material may be formed by coating or the like on the surface of the main wafer 200.

[0072] As shown in FIGS. 8 and 11, the first dicing step forms first dicing lines 210 on the main wafer 200, which will later become the discharge channels 61. Specifically, a dicer is inserted into the main wafer 200 from the front side and travels a predetermined distance. The length of the first dicing lines 210 along the extension direction L1 is set to a length equivalent to approximately two discharge channels 61. Therefore, both ends of the first dicing lines 210 in the extension direction L1 function as the cut-up portions 61b (see FIG. 3) of the discharge channels 61, and the central portion of the first dicing lines 210 in the extension direction L1 functions as the extended portion 61a (see FIG. 3). In the first dicing step, the above-described operation is repeatedly performed at intervals on the main wafer 200 in the extension direction L1 and in a cross direction intersecting the extension direction L1 (hereinafter referred to as the cross direction L2).

[0073] 8 and 19, in the second dicing step, second dicing lines 211 that will later become non-ejection channels 62 are formed. Specifically, a dicer is inserted into portions of the main wafer 200 located on both sides of the first dicing lines 210 in the X direction, and is caused to run over the entire length of the main wafer 200 in the extension direction L1. As a result, second dicing lines 211 are formed between adjacent first dicing lines 210.

[0074] 12 and 20, in the low dielectric film forming step, a low dielectric film 110 is formed on a main wafer 200. Specifically, the low dielectric film forming step is performed by obliquely depositing a material for forming the low dielectric film 110 onto the surface of the main wafer 200 with a metal mask (first mask) 220 set on the surface of the main wafer 200. The metal mask 220 is formed in a plate shape having mask openings (first mask opening 221a and second mask opening 221b) in portions of the main wafer 200 that overlap with the formation region of the low dielectric film 110.

[0075] The first mask opening 221a is located at the center of the first dicing line 210 in the extension direction L1. The first mask opening 221a has a length in the extension direction L1 that is approximately twice the length of the above-mentioned first low dielectric film 118a (D1×2). The first mask opening 221a has a width in the intersecting direction L2 that spans all of the dicing lines 210, 211. However, the first mask opening 221a may be formed for each one or more dicing lines 210, 211.

[0076] The second mask openings 221b are located on both sides of the first mask opening 221a in the extension direction L1. One of the second mask openings 221b extends from one end of the first dicing line 210 to an area outside the first dicing line 210. The other second mask opening 221b extends from the other end of the first dicing line 210 to an area outside the first dicing line 210.

[0077] A portion of the metal mask 220 located between one second mask opening 221b and the first mask opening 221a, and a portion of the metal mask 220 located between the other second mask opening 221b and the first mask opening 221a each constitute a channel covering portion (covering portion) 222. Each channel covering portion 222 overlaps with the driving regions 125, 135, and has a dimension in the extension direction L1 set to be smaller than the dimension D0 of the pump portion 100. Furthermore, a portion of the metal mask 220 located between adjacent first dicing lines 210 and on the opposite side of the second mask opening 221b from the channel covering portion 222 constitutes a tail covering portion 223.

[0078] In the low dielectric film forming process, the metal mask 220 is set on the surface of the main wafer 200. At this time, it is preferable that the center of the first mask opening 221a in the extension direction L1 coincides with the center of the first dicing line 210 in the extension direction L1. This causes the center of the pump section 100 in the Z direction to coincide with the center of the driving regions 125, 135 (channel covering section 222) in the Z direction. In this state, oblique deposition is performed on the surface of the main wafer 200, so that the material for the low dielectric film 110 is deposited on the main wafer 200 through the mask openings 221a, 221b. That is, the low dielectric film 110 is deposited on the surface of the main wafer 200 and on the +Y side of the inner surfaces of each dicing line 210, 211. After the low dielectric film forming process, the metal mask 220 is removed.

[0079] 13 and 21, in the first wiring formation process, an electrode material is deposited by oblique deposition or the like on the surface of the main wafer 200 via a mask pattern (not shown). As a result, the common wiring 111 and parts of the individual wiring 112 (first common electrode portion 123a, first individual electrode portion 130a, common terminal 121, and individual terminal 131) are formed on the surface of the main wafer 200 and the inner surfaces of each dicing line 210, 211. In this case, as shown in FIG. 13, part of the first common electrode portion 123a is deposited via the low dielectric film 110 at appropriate locations (both ends and the center) of the first dicing line 210. The common terminal 121 is deposited on the surface of the main wafer 200 via the low dielectric film 110. The individual terminal 131 is formed directly on the surface of the main wafer 200. As shown in FIG. 21, a part of the first individual electrode portion 130a is formed at an appropriate position on the second dicing line 211 with the low dielectric film 110 interposed therebetween.

[0080] 9, in the third dicing step, third dicing lines 213 are formed which will later become the partitioning grooves 79. Specifically, a dicer is inserted into the main wafer 200 from the front side into a portion of the main wafer 200 located between adjacent first dicing lines 210 in the extension direction L1, and the dicer is caused to travel in the intersecting direction L2.

[0081] As shown in FIGS. 14 and 22, in the cover wafer laminating step, a cover wafer 230, which will later become the cover plate 54, is laminated on the surface of the main wafer 200 in the Y direction. As shown in FIGS. 15 and 23, in the grinding step, the rear surface of the main wafer 200 is subjected to grinding processing, and the first dicing lines 210 and the second dicing lines 211 are opened on the rear surface of the main wafer 200.

[0082] 16 and 24, the second wiring formation step is performed by obliquely depositing an electrode material onto the back surface of the main wafer 200 with a metal mask (second mask) 240 set on the back surface of the main wafer 200. The metal mask 240 is formed in a plate shape having mask openings (third mask openings) 241 in portions of the main wafer 200 that overlap with the formation regions of the second common electrode portion 123b and the second individual electrode portion 130b.

[0083] The mask openings 241 are located on both sides of the center of the first dicing line 210 in the extension direction L1. The mask openings 241 are portions that overlap with the driving regions 125, 135, and the dimension in the extension direction L1 is set to be smaller than the dimension D0 of the pump section 100. The mask openings 241 have a width in the intersecting direction L2 that spans all of the dicing lines 210, 211. However, the mask openings 241 may be formed for one or more dicing lines 210, 211.

[0084] A portion of the metal mask 240 located between the mask openings 241 that overlap one first dicing line 210 constitutes a central covering portion 242a. The central covering portion 242a is located at the center of the first dicing line 210 in the extension direction L1. A portion of the metal mask 240 located on the opposite side of the mask opening 241 from the central covering portion 242a constitutes an outer covering portion 242b. The outer covering portion 242b extends from the end of the first dicing line 210 to an area outside the first dicing line 210.

[0085] In the second wiring formation process, the metal mask 240 is set on the back surface of the main wafer 200. At this time, it is preferable that the center of the central covering portion 242a in the extension direction L1 coincides with the center of the first dicing line 210 in the extension direction L1. As a result, the center of the pump portion 100 in the Z direction coincides with the center of the driving regions 125, 135 (mask opening 241) in the Z direction. In this state, oblique deposition is performed on the back surface of the main wafer 200, and an electrode material is formed on the inner surface of each dicing line 210, 211 through the mask opening 241. In this case, as shown in FIG. 16, the second common electrode portion 123b is formed on the inner surface of the first dicing line 210 except for the center and both end portions in the extension direction L1. Meanwhile, as shown in FIG. 24, the second individual electrode portion 130b is formed on the inner surface of the second dicing line 211 in a portion facing the second common electrode portion 123b in the intersecting direction L2.

[0086] 17, in the back wafer stacking step, a back wafer 245, which will later become the back plate 56, is stacked on the back surface of the main wafer 200. As a result, the dicing lines 210 and 211 are closed.

[0087] 10 and 18, in the singulation process, a wafer assembly 246 consisting of a main wafer 200, a cover wafer 230, and a back wafer 245 is divided into individual head chips 50. Specifically, a dicer is run in the intersecting direction L2 along the center of the first dicing lines 210 in the extension direction L1 (see Q1 in FIG. 9) and along the portions of the wafer assembly 246 located between adjacent first dicing lines 210 in the extension direction L1 (see Q2 in FIG. 9). This forms a plurality of chip assembly 247 in which the above-mentioned actuator plates 53 and cover plates 54 are cut out on a chip-by-chip basis.

[0088] In the nozzle plate bonding step, the nozzle plate 51 is bonded to the chip bonded body 247 cut out in the singulation step. In this way, the head chip 50 is manufactured.

[0089] As described above, in this embodiment, the inner surface of the discharge channel 61 is provided with a first low dielectric film 118a at the lower end, a second low dielectric film 118b at the upper end, and a first common electrode portion 123a that is provided from the upper end to the lower end and covers the first low dielectric film 118a and the second low dielectric film 118b. According to this configuration, when the inner side surface portions 118 (the first low dielectric film 118a and the second low dielectric film 118b) are formed at both ends of the ejection channel 61, a metal mask 220 is disposed, which has mask openings 221a and 221b corresponding to the regions of the ejection channel 61 where the low dielectric films 118a and 118b are formed, and has covering portions 222 and 223 corresponding to the regions where the low dielectric films 118a and 118b are not formed. In this case, the regions where the low dielectric films 118a and 118b are formed can be used as an allowance for allowing misalignment of the channel covering portions 222. That is, compared to a case where the inner side surface portions 118 are provided only at either end of the ejection channel 61 in the Z direction (extension direction L1), where the channel covering portions 222 are aligned at either end of the ejection channel 61, the dimensions of the regions where the inner side surface portions 118 are not formed are more likely to be uniform between the ejection channels 61 even when the channel covering portions 222 are misaligned. As a result, variations in ejection performance among the ejection channels 61 can be suppressed.

[0090] The above-mentioned effects will be explained with reference to the drawings. Figures 33 and 34 are cross-sectional views of head chip 50 according to the prior art. Figures 25 and 26 are cross-sectional views of head chip 50 according to this embodiment. In the following explanation, the same components as those in head chip 50 according to this embodiment will be assigned the same reference numerals and explanations thereof will be omitted. As shown in FIGS. 33 and 34 , in the conventional head chip 50, the inner surface portion 118 of the low-dielectric film 110 is formed with the channel covering portion 1002 of the metal mask 1001 covering the lower ends of the ejection channels 61. That is, the mask opening 1003 of the metal mask 1001 exposes a portion including the upper ends of the ejection channels 61. In this case, if the metal mask 1001 is misaligned in the Z direction from the desired position, the Z-direction dimension D3 of the common drive region 125 is likely to vary. That is, as shown in FIG. 33 , if the metal mask 1001 is misaligned in the +Z direction from the desired position, the common drive region 125 becomes longer. On the other hand, as shown in FIG. 34 , if the metal mask 1001 is misaligned in the −Z direction from the desired position, the common drive region 125 becomes shorter. As a result, the length of the common drive region 125 differs among the head chips 50 singulated from the wafer bonded body 246 (see FIG. 17 ). As a result, there is a possibility that variations in ejection performance may occur between the head chips 50. Furthermore, if the metal mask 1001 is misaligned around an axis along the Y direction, the length of the common driving region 125 will differ between the ejection channels 61 in the same head chip 50. As a result, there is a possibility that the ejection performance will vary between the ejection channels 61 in the same head chip 50.

[0091] In contrast, in this embodiment, even if the metal mask 220 is misaligned on the -Z side from the desired position as shown in Fig. 25, or even if the metal mask 220 is misaligned on the +Z side from the desired position as shown in Fig. 26, it is possible to suppress dimensional variations in the common drive region 125. Therefore, even if the channel covering portion 222 is misaligned as described above, the dimensions of the non-forming region of the inner side surface portion 118 are likely to be uniform between the ejection channels 61. As a result, it is possible to suppress variations in ejection performance between the ejection channels 61.

[0092] In this embodiment, the distance in the Z direction between the first low dielectric film 118a and the second low dielectric film 118b (the dimension D3 of the common driving region 125) is constant among the multiple ejection channels 61. According to this configuration, the portion of the first common electrode portion 123a located between the first low dielectric film 118a and the second low dielectric film 118b is in direct contact with the inner surface of the ejection channel 61 and functions as a common driving region 125 that contributes to driving the actuator plate 53. In this embodiment, the dimension D3 of the common driving region 125 is constant between each of the ejection channels 61, so that variation in ejection performance between each of the ejection channels 61 can be suppressed.

[0093] In this embodiment, the distance between the first low dielectric film 118a and the second low dielectric film 118b in the Z direction (the dimension D3 of the common driving region 125) is shorter than the length of the pump section 100. According to this configuration, the common driving area 125 can be easily arranged in the pump section 100, so that the pump section 100 can be driven efficiently and the discharge performance can be maintained.

[0094] In this embodiment, the first low dielectric film 118a is located in the pump section 100, and a part of the second low dielectric film 118b is located below the boundary between the pump section 100 and the communication section 101. According to this configuration, regardless of misalignment of the low dielectric films 118a and 118b, the common driving region 125 is reliably positioned in the pump section 100. Therefore, the influence of misalignment of the metal mask 220 for forming the low dielectric film is offset, and it is easy to maintain constant ejection performance between each ejection channel 61.

[0095] In this embodiment, the discharge channel 61 is configured to have a second common electrode portion 123b that is provided on the inner surface of the discharge channel 61 on the -Y side, in an area inside the Z-direction ends, and that is connected to the first common electrode portion 123a on the inner surface of the discharge channel 61. According to this configuration, on the −Y side of the inner surface of the discharge channel 61, the lower end constitutes a first non-formation region 128a where the second common electrode portion 123b is not formed, and the upper end constitutes a second non-formation region 128b where the second common electrode portion 123b is not formed. When the first non-formation region 128a and the second non-formation region 128b are formed, for example, via a metal mask 240, covering portions 242a and 242b are arranged corresponding to the non-formation regions 128a and 128b (both ends in the Z direction) of the discharge channel 61, and a mask opening 241 is arranged corresponding to the formation region of the second common electrode portion 123b. In this case, the non-formation regions 128a and 128b can be used as an allowance for allowing for misalignment of the mask opening 241. That is, even if the metal mask 240 is displaced to the -Z side from the desired position as shown in Fig. 27, or even if the metal mask 240 is displaced to the +Z side from the desired position as shown in Fig. 28, dimensional variations in the second common electrode portion 123b can be suppressed. As a result, compared to a case where only the upper end of the ejection channel 61 is a region where the second common electrode portion 123b is not formed, the dimensions of the second common electrode portion 123b are more likely to be uniform between the ejection channels 61 when the covering portions 242a, 242b are displaced. As a result, variations in ejection performance between the ejection channels 61 can be suppressed.

[0096] Moreover, in this embodiment, the fourth non-forming region 138b is provided on the inner surface of the non-discharge channel 62 in a portion located above the pump portion 100. This configuration can prevent the application of an electric field caused by the current flowing through second individual electrode portion 130b to the portion of driving wall 65 located above pump portion 100 (the portion that is less likely to contribute to driving). This can prevent heat generation in head chip 50 and reduce power consumption.

[0097] In this embodiment, the dimension of the second common electrode portion 123b in the Z direction is constant among the multiple ejection channels 61. According to this configuration, variations in ejection performance among the ejection channels 61 can be suppressed.

[0098] In this embodiment, the first non-forming region 128a is located in the pump portion 100, and a part of the second non-forming region 128b is located below the boundary between the pump portion 100 and the communication portion 101. According to this configuration, the second common electrode portion 123b is reliably arranged in the pump portion 100, so that the pump portion 100 can be driven efficiently and the ejection performance can be maintained.

[0099] The inkjet head 5 and printer 1 of this embodiment are equipped with the head chip 50 described above, and therefore it is possible to achieve uniformity in ejection performance between each ejection channel 61 in the same head chip 50 or between multiple head chips 50, thereby providing an inkjet head 5 and printer 1 with excellent marketability.

[0100] (First Modification) 29, in the head chip 50 of this modified example, the entire second low dielectric film 118b is provided in a portion located above the boundary between the pump section 100 and the communication section 101. That is, as a result of the metal mask 220 being misaligned to the +Z side, the entire second low dielectric film 118b is provided in the communication section 101. In this modified example, the first common electrode portion 123a is provided over the entire area in the Z direction, so that when the second low dielectric film 118b is located in the communication portion 101, the upper end portion of the common driving region 125 is located in the communication portion 101.

[0101] As in this modification, even when a portion of the common driving region 125 is positioned off-center from the pump section 100 due to misalignment of the metal mask 220, the dimension D3 of the common driving region 125 remains constant. In this case, a portion of the first common electrode portion 123a located above the boundary between the pump section 100 and the communication section 101 (hereinafter referred to as the "protruding portion") directly contacts the inner surface of the ejection channel 61. Therefore, the protruding portion can contribute to driving the ejection channel 61 to a considerable extent. As a result, when the entire second low dielectric film 118b is located in the communication section 101, the deterioration of ejection performance can be suppressed compared to a configuration in which the common driving region 125 is contained within the pump section 100. In other words, the effect on ejection performance caused by misalignment of the metal mask 220 used for forming the low dielectric film can be reduced as much as possible.

[0102] (Second Modification) 30 , in head chip 50 of this modified example, second non-forming region 128b is entirely provided in a portion located above the boundary between pump portion 100 and communication portion 101. That is, as a result of metal mask 240 being misaligned to the +Z side, second non-forming region 128b is entirely provided in communication portion 101. Therefore, a portion (upper end portion) of second common electrode portion 123b is located in communication portion 101.

[0103] In this case, the portion of the second common electrode portion 123b located above the boundary between the pump portion 100 and the communication portion 101 (hereinafter referred to as the protruding portion) can be made to contribute to driving the ejection channel to a considerable extent. This makes it possible to suppress a decrease in ejection performance compared to a configuration in which the second common electrode portion 123b is contained within the pump portion 100. In other words, it is possible to reduce as much as possible the effect on ejection performance caused by misalignment of the metal mask 240 used for forming the low dielectric film.

[0104] (Third Modification) In the above-described embodiment and various modified examples, the non-formation areas 128a, 128b, 138a, and 138b are provided on both sides of the second common electrode portion 123b and the second individual electrode portion 130b in the Z direction. However, in the present disclosure, the non-formation areas 128a, 128b, 138a, and 138b may not be provided. 31, the second common electrode portion 123b extends over the entire area of ​​the extending portion 61a in a portion located on the -Y side of the inner surface of the ejection channel 61. The lower end of the second common electrode portion 123b coincides with the lower end of the ejection channel 61. On the other hand, the upper end of the second common electrode portion 123b reaches the boundary (knife edge portion) between the bottom surface of the extending portion 61a and the bottom surface of the cut-up portion 61b.

[0105] 32, the second individual electrode portion 130b extends over the entire area in the Z direction in a portion located on the -Y side of the inner surface of the non-ejection channel 62. The lower end of the second common electrode portion 123b coincides with the lower end of the non-ejection channel 62. On the other hand, the upper end of the second individual electrode portion 130b coincides with the upper end of the non-ejection channel 62.

[0106] According to this modification, the dimensions of the second common electrode portion 123b and the second individual electrode portion 130b in the Z direction can be ensured, and therefore the second common electrode portion 123b and the second individual electrode portion 130b can be easily made to contribute to driving the ejection channels 61. As a result, the output of the head chip 50 can be easily improved.

[0107] (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-described 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, a fax machine, an on-demand printer, etc. may also be used. In the above-described embodiment, a configuration in which the inkjet head moves relative to the recording medium during printing (a 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 also be employed in a configuration in which the inkjet head is fixed and the recording medium moves relative to the inkjet head (a so-called fixed head machine). In the above-described embodiment, the recording medium P is paper, but this is not limiting. 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, a configuration in which the liquid jet head is mounted on a liquid jet recording apparatus has been described, but the present invention is not limited to this configuration. That is, the liquid jetted from the liquid jet head is not limited to the liquid that lands on a recording medium, but may be, for example, a medicinal liquid to be mixed into a medicine, a food additive such as a seasoning or flavoring to be added to food, or an aromatic to be sprayed into the air.

[0108] In the above-described embodiment, the Z direction coincides with the direction of gravity, but the invention is not limited to this configuration, and the Z direction may be aligned with the horizontal direction. In the above-described embodiment, the first direction coincides with the Z direction and the second direction coincides with the X direction, but the present invention is not limited to this configuration. The first direction and the second direction may be defined separately from the X direction and the Z direction.

[0109] In the above-described embodiment, the low dielectric films 118a, 118b, 116a, and 116b are formed only on the +Y side of the inner surface of each of the channels 61 and 62. However, the present invention is not limited to this configuration. The low dielectric films may be formed over the entire inner surface of each of the channels 61 and 62 in the Y direction. In the above-described embodiment, the electrodes (for example, the first common electrode portion 123a and the second common electrode portion 123b) are formed in separate processes on the +Y side and the −Y side of the inner surface of the channel, but the present invention is not limited to this. The first common electrode portion 123a and the first individual electrode portion 130a may be formed collectively over the entire area of ​​the inner surface of the channel in the Y direction.

[0110] In the above-described embodiment, the low dielectric films 118a, 118b, 116a, and 116b are formed on the inner surfaces of the channels 61 and 62, respectively. However, the present invention is not limited to this configuration. The low dielectric film may be provided only on the inner surface of either the ejection channel 61 or the non-ejection channel 62. In the above-described embodiment, the configuration in which the ejection channels 61 and the non-ejection channels 62 are alternately arranged has been described, but the present disclosure is not limited to this. For example, the present disclosure may be applied to a head chip 50 of a so-called three-cycle system in which ink is ejected sequentially from all channels.

[0111] In the above-described embodiment, the actuator plate 53 is described as a chevron type in which two piezoelectric plates having different polarization directions in the Y direction are stacked, but this configuration is not limiting. The actuator plate 53 may also be formed of a single piezoelectric plate whose polarization direction is unidirectional throughout the Y direction (thickness direction) (so-called monopole type). In the monopole type head chip 50, various electrodes are provided on at least the +Y side of each channel 61, 62, including the center in the Y direction.

[0112] 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]

[0113] 1...Inkjet printer (liquid jet recording device) 5...Inkjet head (liquid jet head) 50...Head tip 51...Nozzle plate (injection hole plate) 53...Actuator plate 51...Nozzle plate (injection hole plate) 54...Cover plate (flow path member) 61...Discharge channel (injection channel) 78: Tail 91: Inlet slit (liquid flow path) 100: Pump section 101:Communication part 102: Nozzle hole (injection hole) 110: Low dielectric film 118a: First low dielectric film 118b: Second low dielectric film 120: Common electrode (electrode) 121: Common terminal (terminal part) 123a: First common electrode part (first electrode part) 123b: Second common electrode part (second electrode part) 128a: First non-formation area 128b: 2nd non-formation area 221a: First mask opening 221b: Second mask opening 222: Covering part 241: Mask opening (third mask opening)

Claims

1. an actuator plate having ejection channels extending in a first direction and spaced apart in a second direction intersecting the first direction, the ejection channels having an end face at which first side ends in the first direction open; an injection hole plate having injection holes communicating with the injection channel and disposed opposite the end surface; a cover plate having a liquid flow path communicating with the ejection channel at a second side end in the first direction, the cover plate being provided facing the actuator plate in a thickness direction intersecting the second direction when viewed from the first direction, The inner surface of the injection channel has a first low dielectric film provided at a first side end in the first direction; a second low dielectric film provided at a second side end in the first direction; a first electrode portion that is provided from a first side end portion to a second side end portion in the first direction and that covers the first low dielectric film and the second low dielectric film; The injection channel a communication portion overlapping the liquid flow path when viewed in the thickness direction; a pump portion provided on a first side of the communication portion in the first direction, a distance between the first low dielectric film and the second low dielectric film in the first direction is shorter than a length of the pump portion; the first low dielectric film is located in the pump portion, The head chip in which the entire second low dielectric film is located on the second side in the first direction relative to the boundary between the pump section and the communication section.

2. The head chip according to claim 1 , wherein the distance between the first low dielectric film and the second low dielectric film in the first direction is constant among the plurality of ejection channels.

3. the actuator plate includes a tail portion located on a second side of the ejection channel in the first direction; the first electrode portion is located on a first side in the thickness direction of the inner surface of the ejection channel, a terminal portion provided on a main surface of the tail portion facing the first side in the thickness direction and connected to the first electrode portion at an opening edge of the ejection channel; A head chip as described in claim 1 or claim 2, further comprising: a second electrode portion provided on the inner surface of the ejection channel on a second side in the thickness direction, inside the first side end and second side end in the first direction, and connected to the first electrode portion on the inner surface of the ejection channel.

4. The head chip according to claim 3 , wherein the dimension of the second electrode portion in the first direction is constant among the plurality of ejection channels.

5. a first side end portion in the first direction of the second side in the thickness direction of the inner surface of the ejection channel constitutes a first non-forming region in which the second electrode portion is not formed, a second side end portion in the first direction of the second side in the thickness direction of the inner surface of the ejection channel constitutes a second non-formation region in which the second electrode portion is not formed, the first non-forming region is located in the pump portion, 5. The head chip according to claim 3, wherein a part of the second non-forming region is located on the first side in the first direction relative to a boundary between the pump portion and the communication portion.

6. a first side end portion in the first direction of a second side in the thickness direction of the inner surface of the ejection channel constitutes a first non-forming region in which the second electrode portion is not formed; a second side end portion in the first direction of the second side in the thickness direction of the inner surface of the ejection channel constitutes a second non-forming region in which the second electrode portion is not formed, the first non-forming region is located in the pump portion, 5. The head chip according to claim 3, wherein the entire second non-forming region is located on the second side in the first direction relative to a boundary between the pump portion and the communication portion.

7. A liquid-jet head comprising the head chip according to any one of claims 1 to 6.

8. A liquid jet recording apparatus comprising the liquid jet head according to claim 7.

9. a low dielectric film forming step of forming a low dielectric film on an inner surface of an actuator plate having ejection channels extending in a first direction and spaced apart in a second direction intersecting the first direction, using a first mask; an electrode forming step of forming an electrode on the inner surface of the jet channel so as to cover the low dielectric film; a lamination step of overlaying a cover plate having a liquid flow path communicating with the inside of the ejection channel on the actuator plate in a thickness direction intersecting the second direction when viewed from the first direction, The injection channel a communication portion overlapping the liquid flow path when viewed in the thickness direction; a pump portion provided on a first side of the communication portion in the first direction, the first mask is formed with a first mask opening and a second mask opening, the distance between which is set to be shorter than the dimension of the pump portion in the first direction; In the low dielectric film forming step, a material for forming the low dielectric film is introduced into the injection channel through the first mask opening and the second mask opening in a state where a covering portion of the first mask located between the first mask opening and the second mask opening is overlapped with the pump portion, the actuator plate includes a tail portion located on a second side of the ejection channel in the first direction; The electrode forming step includes: a first step of introducing a material for forming the electrode into the injection channel from a first side in the thickness direction; a second step of introducing a material for forming the electrode into the injection channel from a second side in the thickness direction through a second mask, In the first step, the electrode is formed on the inner surface of the ejection channel so as to cover the low dielectric film, and a terminal connected to the electrode is formed on a main surface of the tail portion facing a first side in the thickness direction, the second mask is formed with a third mask opening, the spacing of which in the second direction is set shorter than the dimension of the pump portion in the first direction; In the second step, the electrode forming material is introduced into the ejection channel through the third mask opening in a state where the third mask opening is superimposed on the pump portion.

Images