JP2024081881A - HEAD CHIP, LIQUID JET HEAD, LIQUID JET RECORDING APPARATUS, AND METHOD FOR MANUFACTURING HEAD CHIP - Google Patents

Abstract

[Problem] To suppress a decrease in adhesive strength. [Solution] A head chip includes a plurality of members. Two of the plurality of members that are bonded to each other are a first member 101 and a second member 102. The head chip includes an undercoat adhesive layer 111 formed as a undercoat on a first member side adhesive surface 101f of the first member 101 to which the second member 102 is bonded, and a main adhesive layer 112 formed between the undercoat adhesive layer 111 and the second member 102. The viscosity of the undercoat adhesive layer 111 when uncured is lower than the viscosity of the main adhesive layer 112 when uncured. [Selected Figure] Figure 7

Description

Embodiments of the present disclosure relate to a head chip, a liquid jet head, a liquid jet recording device, and a method for manufacturing the head chip.

Patent Document 1 discloses an inkjet head including a substrate, a piezoelectric member fixed to the substrate, a first adhesive layer formed in an area on the surface of the substrate where the piezoelectric member is fixed, and a second adhesive layer formed between the first adhesive layer and the piezoelectric member. The first adhesive layer and the second adhesive layer are formed with adhesives of different colors. For example, the first adhesive layer is formed by applying an adhesive of a first color by spraying. An adhesive (adhesive of a second color) that forms a second adhesive layer is applied to the bonding surface of the piezoelectric member to the substrate. In this state, the piezoelectric member is placed on the first adhesive layer on the substrate and bonded to each other.

JP 2015-107556 A

However, when applying adhesive by spraying, the first adhesive layer may not be able to fully fill in the small irregularities on the surface of the substrate. For example, on an uneven surface with large differences in height on the surface of the substrate, there is a high possibility that an adhesive surface will be formed that follows the uneven surface. This will likely reduce the adhesive area between the bonded members, and reduce the adhesive strength.

This disclosure was made in consideration of the above problems, and aims to prevent a decrease in adhesive strength.

(1) A head chip according to one aspect of the present disclosure includes a plurality of members, two of which are bonded to each other as a first member and a second member, a base adhesive layer formed as a base on the adhesive surface of the first member to which the second member is bonded, and a main adhesive layer formed between the base adhesive layer and the second member, and the viscosity of the base adhesive layer when uncured is lower than the viscosity of the main adhesive layer when uncured.

According to the head chip of this embodiment, the base adhesive layer can easily penetrate deep into the unevenness of the adhesive surface of the first member to which the second member is adhered, compared to when the viscosity of the base adhesive layer when uncured is higher than the viscosity of the adhesive layer when uncured. This makes it possible to prevent a reduction in the adhesive area between the adherend members. Therefore, it is possible to prevent a decrease in adhesive strength.

(2) In the head chip of aspect (1), the base adhesive layer may have a flat surface on the surface of the base adhesive layer on which the main adhesive layer is formed.

With this configuration, air bubbles are less likely to get into the interface between the base adhesive layer and the main adhesive layer, compared to when the surface of the base adhesive layer on which the main adhesive layer is formed is uneven. Therefore, it is possible to suppress a decrease in adhesion caused by the formation of cavities in the adhesive layer.

(3) In the head chip of aspect (1), the base adhesive layer may have a curved or bent shape on the surface of the base adhesive layer on which the main adhesive layer is formed.

With this configuration, the bonding area between the bonded members is increased compared to when the surface of the base adhesive layer on which the main adhesive layer is formed is a flat surface. This further improves the adhesive strength.

(4) In a head chip according to any one of the aspects (1) to (3), the base adhesive layer may have a wedge shape in which the portion of the second member on which the main adhesive layer is formed bites into the surface of the base adhesive layer on which the main adhesive layer is formed.

With this configuration, the adhesive strength is improved by the anchor effect between the wedge shape of the base adhesive layer and the portion of the second member where this adhesive layer is formed. In addition, compared to an adhesive structure between simple surfaces (e.g., flat surfaces), the adhesive area increases by the surface area of the wedge shape, further improving the adhesive strength.

(5) In the head chip of any one of (1) to (4), the base adhesive layer may have an escape groove into which an excess portion of the main adhesive layer fits on the surface of the base adhesive layer on which the main adhesive layer is formed.

With this configuration, the excess portion of the adhesive layer enters the escape groove, reducing the amount of overflow of the adhesive layer. In addition, air bubbles are permitted to move from the surface of the base adhesive layer on which the adhesive layer is formed to the escape groove, preventing air bubbles from remaining on the surface of the base adhesive layer on which the adhesive layer is formed. Therefore, a decrease in adhesive strength due to air bubbles on the surface of the base adhesive layer on which the adhesive layer is formed can be prevented.

(6) In the head chip of any one of aspects (1) to (5), the base adhesive layer may have a recess or protrusion for positioning the second member on the surface of the base adhesive layer on which the main adhesive layer is formed.

With this configuration, the recesses or protrusions of the base adhesive layer eliminate the need to prepare a separate mark for positioning the second component. Furthermore, positioning by fit is possible, eliminating the need to manually align the marks. Therefore, accurate positioning is possible with ease.

(7) A liquid jet head according to one aspect of the present disclosure includes a head chip according to any one of aspects (1) to (6).

The liquid jet head according to this embodiment can provide a liquid jet head that can suppress a decrease in adhesive strength.

(8) A liquid jet recording device according to one aspect of the present disclosure includes a liquid jet head according to aspect (7) and a carriage to which the liquid jet head is attached.

The liquid jet recording device according to this aspect provides a liquid jet recording device that can suppress a decrease in adhesive strength.

(9) A method for manufacturing a head chip according to one aspect of the present disclosure is a method for manufacturing a head chip having a plurality of members, in which two of the plurality of members to be bonded to each other are a first member and a second member, and includes a first step of forming a base adhesive layer as a base on an adhesive surface of the first member to which the second member is bonded, and a second step of forming this adhesive layer between the base adhesive layer and the second member after the first step, in which the adhesive that becomes the base adhesive layer is pressed against the adhesive surface of the first member using a pressure plate.

According to the head chip manufacturing method of this aspect, by using a pressure plate to press the adhesive that will become the base adhesive layer onto the adhesive surface of the first member, the base adhesive layer can penetrate deep into the unevenness of the adhesive surface of the first member to which the second member is adhered. This makes it possible to prevent a decrease in the adhesive area between the adherends. This makes it possible to prevent a decrease in adhesive strength. In addition, since the shape of the surface that the pressure plate presses against can be transferred, the surface of the base adhesive layer on which this adhesive layer is formed can be given the desired shape and state. This makes it possible to ensure greater adhesive strength than by directly adhering to the adhesive surface of the first member, which has unevenness.

1 is a schematic configuration diagram of an inkjet printer according to a first embodiment. FIG. 2 is a schematic diagram of an inkjet head and an ink circulation unit according to the first embodiment. 1 is an exploded perspective view of an inkjet head according to a first embodiment; 1 is a cross-sectional view of an inkjet head according to a first embodiment. 1 is a cross-sectional view of an inkjet head according to a first embodiment. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. 3A and 3B are explanatory diagrams of an adhesive layer that bonds a first member and a second member according to the first embodiment. 3A to 3C are explanatory diagrams of a first step of the manufacturing method of the head chip according to the first embodiment. 11 is an explanatory diagram of a first step of a manufacturing method of a head chip according to a second embodiment. FIG. 13 is an explanatory diagram of a first step of a manufacturing method of a head chip according to a third embodiment. FIG. FIG. 11 is an explanatory diagram of the first step according to the third embodiment, following FIG. 10 . 13 is an explanatory diagram of a first step of a manufacturing method for a head chip according to a fourth embodiment. FIG. 13 is an explanatory diagram of an example of a first step of a manufacturing method for a head chip according to a fifth embodiment. FIG. 13 is an explanatory diagram of another example of the first step of the manufacturing method of the head chip according to the fifth embodiment. FIG. 13 is an explanatory diagram of an adhesive layer that bonds a first member and a second member according to the sixth embodiment. FIG. 13 is an explanatory diagram of an adhesive layer that bonds a first member and a second member according to a seventh embodiment. FIG. FIG. 13 is an explanatory diagram of a protruding portion of an adhesive layer according to a seventh embodiment. FIG. 23 is a perspective view of a head chip according to an eighth embodiment. FIG. 23 is a perspective view showing a step of a manufacturing method for a head chip according to the eighth embodiment. FIG. 23 is a plan view of a head chip according to an eighth embodiment.

Embodiments according to the present disclosure will be described below with reference to the drawings. In the embodiments, an inkjet printer (hereinafter simply referred to as a "printer") that uses ink (liquid) to record on a recording medium will be described as an example of a liquid ejection device equipped with a liquid ejection head equipped with a liquid ejection head chip (hereinafter simply referred to as a "head chip") according to the present disclosure. Note that in the drawings used in the following description, the scale of each component has been appropriately changed so that each component is of a recognizable size.

In the embodiments and variations described below, corresponding configurations may be given the same reference numerals and descriptions thereof may be omitted. In addition, in the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," do not only strictly indicate such arrangements, but also indicate a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained.

First Embodiment
<Printer>
FIG. 1 is a schematic diagram of a printer 1. As shown in FIG.
As shown in Fig. 1, the printer 1 of this embodiment includes a pair of transport means 2, 3, an ink tank 4, an inkjet head 5 (liquid ejection head), an ink circulation means 6, and a scanning means 7. In the following description, an X, Y, Z orthogonal coordinate system will be used as necessary. The X direction is the transport direction of a recording medium P (e.g., paper, etc.). The Y direction is the scanning direction of the scanning means 7. The Z direction is the up-down direction perpendicular to the X and Y directions.

The conveying means 2 and 3 convey the recording medium P in the X direction. Specifically, the conveying means 2 includes a grit roller 11 extending in the Y direction, a pinch roller 12 extending parallel to the grit roller 11, and a drive mechanism (not shown) such as a motor that rotates the grit roller 11 about its axis. The conveying means 3 includes a grit roller 13 extending in the Y direction, a pinch roller 14 extending parallel to the grit roller 13, and a drive mechanism (not shown) that rotates the grit roller 13 about its axis.

A plurality of ink tanks 4 are provided lined up in one direction. In this embodiment, the ink tanks 4 are ink tanks 4Y, 4M, 4C, and 4K, which respectively contain ink of four colors: yellow, magenta, cyan, and black. In this embodiment, ink tanks 4Y, 4M, 4C, and 4K are arranged lined up in the X direction.

As shown in FIG. 2, the ink circulation means 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation means 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. For example, the ink supply pipe 21 and the ink discharge pipe 22 are made of flexible hoses that are flexible enough to follow the operation of the scanning means 7 that supports the inkjet head 5.

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

As shown in FIG. 1, the scanning means 7 scans the inkjet head 5 back and forth in the Y direction. Specifically, the scanning means 7 includes a pair of guide rails 31, 32 extending in the Y direction, a carriage 33 movably supported on the pair of guide rails 31, 32, and a drive mechanism 34 that moves the carriage 33 in the Y direction. The transport means 2, 3 and the scanning means 7 function as a movement mechanism that moves the inkjet head 5 and the recording medium P relative to each other.

The drive mechanism 34 is disposed between the guide rails 31 and 32 in the X direction. The drive mechanism 34 includes a pair of pulleys 35 and 36 spaced apart in the Y direction, an endless belt 37 wound between the pair of pulleys 35 and 36, and a drive motor 38 that drives and rotates one of the pulleys 35.

The carriage 33 is connected to an endless belt 37. A plurality of inkjet heads 5 are mounted on the carriage 33. In this embodiment, the plurality of inkjet heads 5 are inkjet heads 5Y, 5M, 5C, and 5K that eject ink of four colors, yellow, magenta, cyan, and black, respectively. In this embodiment, the inkjet heads 5Y, 5M, 5C, and 5K are arranged side by side in the Y direction.

<Inkjet head>
3, the inkjet head 5 includes a pair of head chips 40A, 40B, a flow path plate 41, an inlet manifold 42, an outlet manifold (not shown), a feedback plate 43, and a nozzle plate (ejection plate) 44. The inkjet head 5 is of a circulation type (edge chute circulation type) that circulates ink between the ink tank 4 and the ink jet head 5, among so-called edge chute types that eject ink from the tip of the ejection channel 54 in the channel extension direction.

<Head chip>
The pair of head chips 40A, 40B is a first head chip 40A and a second head chip 40B. The following description will focus on the first head chip 40A. In the second head chip 40B, the same components as those in the first head chip 40A are given the same reference numerals, and detailed descriptions thereof will be omitted.
The first head chip 40A includes an actuator plate 51 and a cover plate 52 .

<Actuator plate>
The actuator plate 51 has a rectangular plate shape with its long sides in the X direction and its short sides in the Z direction. In this embodiment, the actuator plate 51 is a so-called chevron type laminated substrate in which two piezoelectric substrates having different polarization directions in the thickness direction (Y direction) are laminated (see FIG. 6). For example, a ceramic substrate made of PZT (lead zirconate titanate) or the like is preferably used as the piezoelectric substrate.

A plurality of channels 54, 55 are formed on the first main surface in the Y direction of the actuator plate 51 (first main surface on the actuator plate side). In the embodiment, the first main surface on the actuator plate side is the Y direction inner surface 51f1 of the actuator plate 51 (hereinafter referred to as the "AP side Y direction inner surface 51f1"). Here, the inner side in the Y direction means the center side in the Y direction of the inkjet head 5 (the side of the flow path plate 41 in the Y direction). In the embodiment, the second main surface on the actuator plate side is the Y direction outer surface of the actuator plate 51 (indicated by the reference symbol 51f2 in the figure).

Each channel 54, 55 is formed in a straight line extending in the Z direction (first direction). Each channel 54, 55 is formed alternately at intervals in the X direction (second direction). Each channel 54, 55 is defined between by a driving wall 56 made of the actuator plate 51. One channel 54 is an ejection channel 54 (ejection channel) that is filled with ink. The other channel 55 is a non-ejection channel 55 (non-ejection channel) that is not filled with ink.

FIG. 4 is a diagram including a cross section of the ejection channel 54 in the first head chip 40A.
As shown in FIG. 4, the discharge channel 54 has an extending portion 54a located at the lower end, and a cut-up portion 54b continuing upward from the extending portion 54a.
The extending portion 54a has a uniform groove depth over the entire length in the Z direction. The raised portion 54b has a groove depth that gradually becomes shallower toward the top.

As shown in FIG. 3, the upper end of the non-ejection channel 55 opens at the upper end surface of the actuator plate 51. The lower end of the non-ejection channel 55 opens at the lower end surface of the actuator plate 51.

FIG. 5 is a diagram including a cross section of the non-ejection channel 55 in the first head chip 40A.
As shown in FIG. 5, the non-ejection channel 55 has an extending portion 55a located at the lower end, and a cut-up portion 55b continuing upward from the extending portion 55a.
The extending portion 55a has a uniform groove depth over the entire length in the Z direction. The raised portion 55b has a groove depth that gradually becomes shallower toward the top.

As shown in FIG. 4, a common electrode 61 is formed on the inner surface of the ejection channel 54. An actuator plate side common pad 62 (hereinafter referred to as "AP side common pad 62") is formed on the Y direction inner surface of a portion 51e (hereinafter referred to as "AP side tail 51e") of the actuator plate 51 located above the ejection channel 54. The AP side common pad 62 is continuous with the common electrode 61. As shown in FIG. 3, a plurality of AP side common pads 62 are arranged at intervals in the X direction on the Y direction inner surface of the AP side tail 51e.

As shown in FIG. 5, individual electrodes 63 are formed on the inner surface of the non-ejection channel 55. As shown in FIG. 6, the individual electrodes 63 are formed separately on the inner surfaces of the non-ejection channel 55 that face each other in the X direction. Therefore, among the individual electrodes 63, the individual electrodes 63 that face each other within the same non-ejection channel 55 are electrically separated at the bottom surface of the non-ejection channel 55. The individual electrodes 63 are formed over the entire inner surface of the non-ejection channel 55 (the entire Y direction and Z direction).

As shown in FIG. 5, actuator plate side individual wiring 64 (hereinafter referred to as "AP side individual wiring 64") is formed on the Y direction inner surface of the AP side tail portion 51e. As shown in FIG. 3, the AP side individual wiring 64 extends in the X direction on the Y direction inner surface of the AP side tail portion 51e that is located above the AP side common pad 62. The AP side individual wiring 64 connects opposing individual electrodes 63 with the ejection channel 54 in between.

<Cover plate>
As shown in FIG. 3, the cover plate 52 has a rectangular plate shape with a long side in the X direction and a short side in the Z direction. The first main surface (cover plate side first main surface) of the cover plate 52 facing the AP side Y direction inner surface 51f1 is joined to the AP side Y direction inner surface 51f1. In the embodiment, the cover plate side first main surface is the Y direction outer surface 52f1 (hereinafter referred to as the "CP side Y direction outer surface 52f1") of the cover plate 52. Here, the Y direction outer side means the opposite side to the Y direction center side of the inkjet head 5 (the opposite side to the flow path plate 41 side in the Y direction). In the embodiment, the cover plate side second main surface is the Y direction inner surface 52f2 (hereinafter referred to as the "CP side Y direction inner surface 52f2") of the cover plate 52.

The cover plate 52 is formed with a liquid supply passage 70 that penetrates the cover plate 52 in the Y direction (third direction) and communicates with the ejection channels 54. The liquid supply passage 70 includes a common ink chamber 71 that opens on the inside of the cover plate 52 in the Y direction, and a plurality of slits 72 that communicate with the common ink chamber 71, open on the outside in the Y direction, and are spaced apart in the X direction. The common ink chamber 71 communicates with each of the ejection channels 54 through the slits 72. On the other hand, the common ink chamber 71 does not communicate with the non-ejection channels 55.

As shown in FIG. 4, a common electrode 65 (hereinafter referred to as the "liquid supply path inner electrode 65") is formed on the inner surface of the liquid supply path 70 in the cover plate 52. A cover plate side common pad 66 (hereinafter referred to as the "CP side common pad 66") is formed around the slit 72 on the CP side Y direction outer surface 52f1. A common lead wiring 67 is formed around the common ink chamber 71 on the CP side Y direction inner surface 52f2. As shown in FIG. 3, a plurality of recesses 73 are formed on the upper end of the cover plate 52, recessed inward in the Z direction of the cover plate 52 and spaced apart in the X direction.

As shown in FIG. 4, the common outgoing wiring 67 is drawn out to the Y-direction outer surface of the portion 52e (hereinafter referred to as the "CP side tail portion 52e") of the cover plate 52 located above the actuator plate 51. As a result, the common electrode 61 formed on the inner surface of the multiple ejection channels 54 is electrically connected to the flexible substrate 45 (external wiring) at the common terminal 68 via the AP side common pad 62, the CP side common pad 66, the liquid supply path inner electrode 65, and the common outgoing wiring 67. In the embodiment, the common outgoing wiring 67 and the liquid supply path inner electrode 65 constitute the connection wiring 60 that connects the common electrode 61 and the flexible substrate 45.

Cover plate side individual wiring 69 (hereinafter referred to as "CP side individual wiring 69") is formed on the cover plate 52. The CP side individual wiring 69 includes cover plate side individual pads 69a (hereinafter referred to as "CP side individual pads 69a") arranged at positions corresponding to the AP side individual wiring 64 when the actuator plate 51 and the cover plate 52 are joined, and individual terminals 69b formed by extending linearly upward after being inclined so as to be positioned outward in the X direction toward the upper side from the CP side individual pads 69a.

The individual terminals 69b extend to the upper end of the Y-direction outer surface of the CP-side tail 52e. As a result, the individual electrodes 63 formed on the inner surface of the multiple non-ejection channels 55 are electrically connected to the flexible substrate 45 (see FIG. 5) at the individual terminals 69b via the AP-side individual wiring 64 and the CP-side individual pads 69a. In the embodiment, the Y-direction outer surface of the CP-side tail 52e serves as the connection surface to which the flexible substrate 45 is connected.

<Flow path plate>
The flow path plate 41 is sandwiched between the first head chip 40A and the second head chip 40B in the Y direction. As shown in FIG. 3, the outer shape of the flow path plate 41 is a rectangular plate having a long side in the X direction and a short side in the Z direction. The CP-side Y-direction inner side surface 52f2 of the first head chip 40A is joined to the first main surface 41f1 (surface facing the first head chip 40A) in the Y direction of the flow path plate 41. The CP-side Y-direction inner side surface 52f2 of the second head chip 40B is joined to the second main surface 41f2 (surface facing the second head chip 40B) in the Y direction of the flow path plate 41.

Each of the main surfaces 41f1 and 41f2 of the flow path plate 41 is formed with an inlet flow path 74 that is individually connected to the common ink chamber 71, and an outlet flow path 75 that is individually connected to the circulation path 76 of the feedback plate 43. The flow path plate 41 is formed so that the inlet flow path 74 and the outlet flow path 75 are aligned in the Z direction.

Each inlet flow channel 74 includes an inlet liquid storage section 74s that temporarily stores ink before the ink flows into the common ink chamber 71. As shown in FIG. 3, the inlet liquid storage section 74s extends linearly in the X direction at the center of the top and bottom of the flow channel plate 41 while maintaining a constant vertical width. As shown in FIG. 4, the flow channel plate 41 is provided with an inlet flow channel partition wall 41a that divides the inlet flow channel 74 into the first head chip 40A side and the second head chip 40B side in the Y direction.

The outlet flow passages 75 are connected to an outlet manifold (not shown) at the other end surface in the X direction of the flow passage plate 41. The outlet manifold is connected to the ink discharge pipe 22 (see FIG. 1). Each outlet flow passage 75 includes an outlet liquid storage section 75s that temporarily stores ink flowing out of the circulation path 76. As shown in FIG. 3, the outlet liquid storage section 75s extends linearly in the X direction at the lower end of the flow passage plate 41 while maintaining a constant vertical width.

As shown in FIG. 4, the flow path plate 41 is provided with an outlet flow path partition wall 41b that divides the outlet flow path 75 into the first head chip 40A side and the second head chip 40B side in the Y direction. In the cross-sectional view of FIG. 4, the inlet flow path 74 and the outlet flow path 75 are not formed in the portion of the flow path plate 41 that overlaps with the CP side tail portion 52e in the Y direction. In other words, the portion of the flow path plate 41 that overlaps with the CP side tail portion 52e in the Y direction is made of a solid member 41c.

<Inlet manifold>
3, the inlet manifold 42 is joined together to one end surface in the X direction of each of the head chips 40A, 40B and the flow path plate 41. The inlet manifold 42 is formed with a supply path 77 that communicates with each inlet flow path 74. The inlet manifold 42 is connected to the ink supply pipe 21 (see FIG. 1).

<Feedback plate>
The feedback plate 43 has a rectangular plate shape with a long side in the X direction and a short side in the Y direction. The feedback plate 43 is joined together to the lower end surfaces of the head chips 40A, 40B and the flow path plate 41. The feedback plate 43 has a plurality of circulation paths 76 formed therein, which connect the ejection channels 54 of the head chips 40A, 40B to the outlet flow paths 75. The plurality of circulation paths 76 include a first circulation path 76a and a second circulation path 76b. The plurality of circulation paths 76 penetrate the feedback plate 43 in the Z direction.

As shown in FIG. 4, the first circulation path 76a extends in the Y direction. The inner end of the first circulation path 76a in the Y direction is connected to the outlet flow path 75. The outer end of the first circulation path 76a in the Y direction is connected to each of the ejection channels 54 of the first head chip 40A.

As shown in FIG. 5, the second circulation path 76b extends in the Y direction. The inner end of the second circulation path 76b in the Y direction is connected to the outlet flow path 75. The outer end of the second circulation path 76b in the Y direction is connected to each of the ejection channels 54 of the second head chip 40B.

<Nozzle plate>
3, the nozzle plate 44 has an outer shape like a rectangular plate with its long sides in the X direction and its short sides in the Y direction. The nozzle plate 44 is joined to the lower end surface of the feedback plate 43. The nozzle plate 44 has an array of multiple nozzle holes 78 (injection holes) that penetrate the nozzle plate 44 in the Z direction. The multiple nozzle holes 78 include a first nozzle hole 78a and a second nozzle hole 78b.

As shown in FIG. 4, each of the first nozzle holes 78a communicates with a corresponding ejection channel 54 of the first head chip 40A via a first circulation path 76a.
As shown in FIG. 5, each of the second nozzle holes 78b communicates with a corresponding ejection channel 54 of the second head chip 40B via a second circulation path 76b.
On the other hand, each of the non-ejection channels 55 does not communicate with the nozzle holes 78a, 78b, and is covered from below by the feedback plate 43.

<Adhesive Layer>
FIG. 7 is an explanatory diagram of an adhesive layer 110 that bonds the first member 101 and the second member 102 according to the first embodiment.
7, the head chips 40A and 40B include a plurality of members including an actuator plate 51 having an ejection channel 54 (corresponding to a channel through which liquid passes). Two of the plurality of members that are bonded to each other are a first member 101 and a second member 102. The head chips 40A and 40B include an adhesive layer 110 between the first member 101 and the second member 102.

The adhesive layer 110 comprises a base adhesive layer 111 formed as a base on the adhesive surface 101f of the first member 101 to which the second member 102 is adhered, and a main adhesive layer 112 formed between the base adhesive layer 111 and the second member 102. The adhesive layer 110 is formed by laminating the main adhesive layer 112 on the base adhesive layer 111. The viscosity of the base adhesive layer 111 when uncured is lower than the viscosity of the main adhesive layer 112 when uncured.

For example, the adhesive layer 110 may be formed from a resin material such as a thermosetting resin or an ultraviolet-curing resin. For example, the base adhesive layer 111 may be formed from an epoxy-based adhesive. For example, the main adhesive layer 112 may be formed from an acrylic-based adhesive. Note that the materials for the base adhesive layer 111 and the main adhesive layer 112 are not limited to those mentioned above. For example, the materials for the base adhesive layer 111 and the main adhesive layer 112 can be changed according to the design specifications.

The example of FIG. 7 shows the adhesive surface 101f (hereinafter also referred to as the "first member adhesive surface 101f") of the first member 101 to which the second member 102 is adhered. In FIG. 7, the fine irregularities on the first member adhesive surface 101f are exaggerated, with reference numeral 101a indicating an example of a concave portion and reference numeral 101b indicating an example of a convex portion. For comparison, in FIG. 7, a two-dot chain line indicates a virtual line 101v in the case where the first member adhesive surface 101f is assumed to be flat. Here, the base adhesive layer 111 penetrates deep into the irregularities of the first member adhesive surface 101f (inside the concave portion 101a). The base adhesive layer 111 covers the entire first member adhesive surface 101f without any gaps.

The base adhesive layer 111 has a flat surface 111f on the surface of the base adhesive layer 111 on which the main adhesive layer 112 is formed (corresponding to the upper surface of the base adhesive layer 111).

The upper surface (flat surface 111f) of the base adhesive layer 111 is a flat surface that is generally parallel to the adhesive surface of the second member 102 to which the first member 101 is adhered (hereinafter also referred to as the "second member side adhesive surface 102f"; equivalent to the lower surface of the second member 102). The upper surface of the base adhesive layer 111 is formed in a flat surface that includes the upper ends (the uppermost ends of the convex portions 101b) of the irregularities on the first member side adhesive surface 101f within the plane.

The adhesive layer 112 is interposed between the lower surface of the second member 102 (corresponding to the second member side adhesive surface 102f) and the upper surface (flat surface 111f) of the base adhesive layer 111. The adhesive layer 112 covers the entire second member side adhesive surface 102f without any gaps. The adhesive layer 112 covers the entire upper surface (flat surface 111f) of the base adhesive layer 111 without any gaps. The interface 103 between the base adhesive layer 111 and the adhesive layer 112 has the upper end (the uppermost end of the convex portion 101b) of the irregularities on the first member side adhesive surface 101f within the plane. The interface 103 refers to the boundary where the base adhesive layer 111 and the adhesive layer 112 are in contact with each other.

<How the printer works>
Next, a method of operation of the printer 1 when using the printer 1 to record characters, figures, etc. on the recording medium P will be described.
1 are each filled with a sufficient amount of ink of a different color. Also, the ink in the ink tanks 4 is filled in the inkjet head 5 via the ink circulation means 6.

1, when the printer 1 is operated in the initial state, the grit rollers 11 and 13 of the conveying means 2 and 3 rotate, conveying the recording medium P in the conveying direction (X direction) between the grit rollers 11 and 13 and the pinch rollers 12 and 14. At the same time as the recording medium P is conveyed, the drive motor 38 rotates the pulleys 35 and 36 to move the endless belt 37. As a result, the carriage 33 reciprocates in the Y direction while being guided by the guide rails 31 and 32.
During the reciprocating movement of the carriage 33, the inkjet heads 5 eject ink of four colors onto the recording medium P as appropriate, thereby enabling characters, images, and the like to be recorded on the recording medium P.

Here, the movement of each ink-jet head 5 will be described.
In the vertical circulation type inkjet head 5 of the edge shoot type as in this embodiment, the pressurizing pump 24 and the suction pump 25 shown in FIG. 2 are first operated to circulate ink in the circulation flow path 23. In this case, the ink flowing through the ink supply tube 21 passes through the supply path 77 of the inlet manifold 42 shown in FIG. 3 and flows into each inlet flow path 74 of the flow path plate 41. The ink that flows into each inlet flow path 74 passes through each common ink chamber 71, and is then supplied to each ejection channel 54 through the slit 72. The ink that flows into each ejection channel 54 is collected in the outlet flow path 75 through the circulation path 76 of the feedback plate 43, and then is discharged to the ink discharge tube 22 shown in FIG. 2 through the outlet manifold (not shown). The ink discharged to the ink discharge tube 22 is returned to the ink tank 4 and then supplied to the ink supply tube 21 again. In this way, the ink is circulated between the inkjet head 5 and the ink tank 4.

When the carriage 33 (see FIG. 1) starts reciprocating, a drive voltage is applied to each electrode 61, 63 via the flexible substrate 45. At this time, the individual electrode 63 is set to a drive potential Vdd, and the common electrode 61 is set to a reference potential GND, and a drive voltage is applied between each electrode 61, 63. Then, thickness slip deformation occurs in the two drive walls 56 that define the ejection channel 54, and these two drive walls 56 deform so as to protrude toward the non-ejection channel 55 side. That is, since the actuator plate 51 of this embodiment is made of two piezoelectric substrates that have been polarized in the thickness direction (Y direction) and are stacked, applying a drive voltage causes a V-shaped bending deformation centered on the middle position of the drive wall 56 in the Y direction. As a result, the ejection channel 54 deforms as if it is bulging.

When the volume of the ejection channel 54 increases due to the deformation of the two driving walls 56, the ink in the common ink chamber 71 is guided into the ejection channel 54 through the slit 72. The ink guided into the ejection channel 54 becomes a pressure wave and propagates into the ejection channel 54. When this pressure wave reaches the nozzle hole 78, the driving voltage applied between the electrodes 61, 63 is set to zero.
As a result, the driving wall 56 is restored, and the volume of the ejection channel 54, which had increased once, returns to its original volume. This action increases the pressure inside the ejection channel 54, and pressurizes the ink. As a result, the ink can be ejected from the nozzle hole 78. At this time, the ink is ejected as liquid ink droplets as it passes through the nozzle hole 78. This makes it possible to record characters, images, and the like on the recording medium P, as described above.

The method of operation of the inkjet head 5 is not limited to the above. For example, the drive wall 56 in the normal state may be deformed inwardly of the ejection channel 54, so that the ejection channel 54 appears to be recessed inward. In this case, this can be achieved by applying a voltage between the electrodes 61, 63 with a polarity opposite to that of the voltage described above, or by reversing the polarization direction of the actuator plate 51 without changing the polarity of the voltage. In addition, the ejection channel 54 may be deformed so as to bulge outward, and then deformed so as to recess inward, thereby increasing the pressure of the ink when ejected.

<Method of Manufacturing Head Chip>
The manufacturing method of the head chip of this embodiment is a manufacturing method of a head chip equipped with a plurality of members including an actuator plate 51 having an ejection channel 54, and includes a first step of forming a base adhesive layer 111 as a base on the first member side adhesive surface 101f of the first member 101 to which the second member 102 is adhered, and a second step of forming a main adhesive layer 112 between the base adhesive layer 111 and the second member 102 after the first step, in which an adhesive that becomes the base adhesive layer 111 is pressed against the adhesive surface of the first member 101 using a pressure plate 120.
Incidentally, the head chips 40A and 40B can be manufactured in the same manner.

The method for manufacturing the head chip includes a member preparation process for preparing a first member 101 and a second member 102, and a member bonding process for bonding the first member 101 and the second member 102 to each other.

In the member preparation process, multiple members (first member 101 and second member 102) including the actuator plate 51 described above are prepared. For example, at least one of the actuator plate 51, cover plate 52, and flow path plate 41 corresponds to the first member 101, and the feedback plate 43 corresponds to the second member 102 (side-flat adhesion). For example, when the side (surface) of at least one of the actuator plate 51, cover plate 52, and flow path plate 41 is cut with a dicer or the like, the surface becomes rough, resulting in unevenness on the adhesive surface of the first member 101. Note that when the actuator plate 51 corresponds to the first member 101, the cover plate 52 may correspond to the second member 102 (flat adhesion). After the member preparation process, the process proceeds to the member adhesion process.

In the member bonding process, the first member 101 and the second member 102 are bonded to each other by the adhesive layer 110 described above. The member bonding process includes a first process of forming a base adhesive layer 111 on the first member side bonding surface 101f, and a second process of forming a main adhesive layer 112 between the base adhesive layer 111 and the second member 102.

FIG. 8 is an explanatory diagram of a first step of the method for manufacturing the head chip according to the first embodiment.
8, in the first step, the adhesive (hereinafter also referred to as "base adhesive") that will become the base adhesive layer 111 is pressed against the first member side adhesive surface 101f using a pressure plate 120. The pressure plate 120 is a plate member for forming an adhesive surface suitable for adhesion on the unevenness on the first member side adhesive surface 101f that has a height difference that cannot be flattened by application by spraying or the like. In this embodiment, the adhesive surface suitable for adhesion is the flat surface 111f. Therefore, the pressure plate 120 has a planar transfer surface 120f that follows the flat surface 111f.

In the first step, after applying the base adhesive to the extent that the unevenness on the first member side adhesive surface 101f is filled, the pressing plate 120 having the planar transfer surface 120f is pressed from above the base adhesive (in the direction of the arrow in FIG. 8). Then, the pressing plate 120 is separated from the base adhesive. For example, the timing (step) for separating the pressing plate 120 may be the following (1) to (3).
(1) Apply base adhesive → press plate → press plate detach (base adhesive is uncured)
This allows for better compatibility with the adhesive.
(2) Apply base adhesive → press with pressure plate → temporarily harden base adhesive → separate pressure plate. This improves the transferability of the adhesive surface shape of the base adhesive layer and allows for better compatibility with the main adhesive.
(3) Applying base adhesive -> pressing with pressure plate -> base adhesive completely hardening -> detaching with pressure plate. This improves the transferability of the adhesive surface shape of the base adhesive layer.

For example, the pressure plate 120 is formed from a material such as polytetrafluoroethylene or glass that has releasability against the base adhesive. For example, if the base adhesive is made from an epoxy adhesive, it is preferable that the material used to form the pressure plate 120 is polytetrafluoroethylene. For example, the material used to form the pressure plate 120 can be changed according to the design specifications.

In this embodiment, the viscosity of the base adhesive (corresponding to the viscosity of the base adhesive layer 111 when uncured) is lower than the viscosity of the adhesive (hereinafter also referred to as the "main adhesive") that becomes the main adhesive layer 112 (corresponding to the viscosity of the main adhesive layer 112 when uncured). Therefore, in the first step, it is easier to make the base adhesive penetrate deep into the irregularities on the first component side adhesive surface 101f, compared to when the viscosity of the base adhesive is higher than or equal to the viscosity of the main adhesive.

Then, the base adhesive applied to the first component side adhesive surface 101f is cured by heating, ultraviolet irradiation, or the like. As a result, a base adhesive layer 111 is formed on the first component side adhesive surface 101f. After the first process, the process moves to the second process. Note that the base adhesive may also move to the second process in an uncured state.

In the second step, the main adhesive layer 112 is formed between the base adhesive layer 111 and the second member 102. In the second step, the main adhesive is first applied to the upper surface (flat surface 111f) of the base adhesive layer 111. Next, the second member 102 is placed on the upper surface of the base adhesive layer 111 via the main adhesive. Then, the main adhesive between the base adhesive layer 111 and the second member 102 is cured by heating, ultraviolet irradiation, or the like. As a result, the main adhesive layer 112 is formed between the base adhesive layer 111 and the second member 102. That is, the first member 101 and the second member 102 are bonded to each other via the adhesive layer 110 (base adhesive layer 111 and main adhesive layer 112). In addition, in the second step, not only the main adhesive but also the base adhesive may be cured together.
Through the above steps, a head chip is obtained.

Before the second step, a base adhesive layer 111 may be formed on the adhesive surface (second member side adhesive surface 102f) of the second member 102 to which the first member 101 is adhered. For example, as in the first step, a pressure plate 120 may be used to press the base adhesive against the second member side adhesive surface 102f. This allows the first member 101 and the second member 102 to be adhered to each other via the base adhesive layer 111 (two layers) and the main adhesive layer 112. For example, the installation mode of the base adhesive layer 111 on the second member side adhesive surface 102f can be changed according to the design specifications.

For example, the first and second steps may be applied to a method for manufacturing an inkjet head. For example, the method for manufacturing an inkjet head includes a plurality of members including the actuator plate described above, and includes a first step of forming a base adhesive layer 111 as a base on the adhesive surface of the first member 101 to which the second member 102 is attached, and a second step of forming a main adhesive layer 112 between the base adhesive layer 111 and the second member 102 after the first step. In the first step, the adhesive to be the base adhesive layer 111 may be pressed against the adhesive surface of the first member 101 using a pressure plate 120.

For example, the actuator plate 51 may be the first member 101, and the feedback plate 43 may be the second member 102. For example, the actuator plate 51 may be cut with a dicing saw before the actuator plate 51 and the feedback plate 43 are bonded to each other. In this case, the surface (cut surface) of the actuator plate 51 has a very large arithmetic mean roughness (Ra) defined by JIS (JIS B 0601, ISO 25178). Therefore, the surface (cut surface) of the actuator plate 51 is likely to be a rough surface with variations in period, height, and shape. In addition, it is difficult to polish the surface (rough surface) of the actuator plate 51 with a grinder or the like. In particular, when the actuator plate 51 is made of a ceramic substrate made of PZT (lead zirconate titanate) or the like, it is extremely difficult to smooth the surface of the actuator plate 51 by polishing or the like.

For example, if adhesive is applied to the surface (rough surface) of the actuator plate 51 by spraying, the fine irregularities on the surface of the actuator plate 51 may not be sufficiently filled with adhesive. For example, if the surface of the actuator plate 51 has an uneven surface with a large difference in height, there is a high possibility that an adhesive surface will be formed along the uneven surface. As a result, the adhesive area between the adherends (actuator plate 51 and feedback plate 43) will decrease, and the adhesive strength will likely decrease.

In contrast, according to the present manufacturing method, even if the surface (cut surface) of the actuator plate 51 is rough as described above, the adhesive that will become the base adhesive layer 111 can be pressed against the surface of the actuator plate 51 (corresponding to the first member side adhesive surface 101f) using the pressure plate 120 described above, allowing the base adhesive layer 111 to penetrate deep into the unevenness of the surface of the actuator plate 51. This makes it possible to prevent a reduction in the adhesive area between the adherend members (the actuator plate 51 and the feedback plate 43). This is therefore of great practical benefit in preventing a decrease in adhesive strength.

<Action and effect>
The head chips 40A and 40B of this embodiment include a plurality of members including an actuator plate 51 having an ejection channel 54. Two of the plurality of members that are bonded to each other are a first member 101 and a second member 102. The head chips 40A and 40B include a base adhesive layer 111 formed as a base on a first member side adhesive surface 101f of the first member 101 to which the second member 102 is bonded, and a main adhesive layer 112 formed between the base adhesive layer 111 and the second member 102. The viscosity of the base adhesive layer 111 when uncured is lower than the viscosity of the main adhesive layer 112 when uncured.

With this configuration, it is easier for the base adhesive layer 111 to penetrate deep into the irregularities of the first member side adhesive surface 101f, compared to when the viscosity of the base adhesive layer 111 when uncured is higher than the viscosity of the main adhesive layer 112 when uncured. This makes it possible to prevent a reduction in the adhesive area between the adherend members 101, 102. Therefore, it is possible to prevent a decrease in adhesive strength.

The base adhesive layer 111 of this embodiment has a flat surface 111f on the surface of the base adhesive layer 111 on which the main adhesive layer 112 is formed.
With this configuration, compared to a case where the surface of the base adhesive layer 111 on which the main adhesive layer 112 is formed is uneven, air bubbles are less likely to get into the interface 103 between the base adhesive layer 111 and the main adhesive layer 112. Therefore, it is possible to suppress a decrease in adhesion caused by the formation of cavities in the adhesive layer 110.

The inkjet head 5 of this embodiment includes the head chips 40A and 40B described above.
According to this configuration, it is possible to obtain the inkjet head 5 capable of suppressing a decrease in adhesive strength.

The printer 1 of this embodiment includes the inkjet head 5 described above, and a carriage 33 to which the inkjet head 5 is attached.
According to this configuration, a printer 1 capable of suppressing a decrease in adhesive strength can be obtained.

The head chip manufacturing method of this embodiment is a method for manufacturing a head chip having a plurality of members including an actuator plate 51 having an ejection channel 54. Two of the plurality of members that are bonded to each other are a first member 101 and a second member 102. The head chip manufacturing method includes a first step of forming a base adhesive layer 111 as a base on the first member side bonding surface 101f of the first member 101 to which the second member 102 is bonded, and a second step of forming a main adhesive layer 112 between the base adhesive layer 111 and the second member 102 after the first step. In the first step, a pressure plate 120 is used to press the base adhesive that will become the base adhesive layer 111 against the first member side bonding surface 101f.

According to this method, the base adhesive layer 111 can penetrate deep into the unevenness of the first member side adhesive surface 101f by pressing the base adhesive against the first member side adhesive surface 101f using the pressing plate 120. This makes it possible to prevent the adhesion area between the adherend members 101, 102 from decreasing. This makes it possible to prevent a decrease in adhesive strength. In addition, since the shape of the pressing surface of the pressing plate 120 can be transferred, the surface of the base adhesive layer 111 on which the main adhesive layer 112 is formed can be made into the desired shape and state. This makes it possible to ensure adhesive strength more than by directly adhering to the adhesive surface of the first member 101, which has unevenness.

<Modification>
The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the inkjet printer 1 is described as an example of a liquid ejecting apparatus, but the liquid ejecting apparatus is not limited to a printer. For example, a fax machine, an on-demand printer, or the like may be used.

In the above embodiment, a two-row type inkjet head 5 in which the nozzle holes 78 are arranged in two rows has been described, but this is not limited to this. For example, an inkjet head 5 with three or more rows of nozzle holes may also be used, or an inkjet head 5 with a single row of nozzle holes may also be used.

In the above embodiment, a configuration in which the ejection channels 54 and the non-ejection channels 55 are arranged alternately has been described, but the present invention is not limited to this configuration. For example, the present invention may be applied to an inkjet head of a so-called three-cycle system in which ink is ejected sequentially from all channels.

In the above embodiment, a chevron type actuator plate is used, but the present invention is not limited to this. In other words, a monopole type actuator plate (polarization direction is in one direction, the thickness direction) may also be used.

In the above embodiment, the inlet flow path 74 is configured to open at one end surface of the flow path plate 41 in the X direction, but the present invention is not limited to this configuration. For example, the inlet flow path 74 may be configured to open at one end surface of the flow path plate 41 in the Z direction, or the inlet flow path 74 may be configured to open at one end surface of the flow path plate 41 in the Y direction.

In the above embodiment, the outlet flow path 75 is configured to open at the other end surface of the flow path plate 41 in the X direction, but the present invention is not limited to this configuration. For example, the outlet flow path 75 may be configured to open at one end surface of the flow path plate 41 in the Z direction, or the outlet flow path 75 may be configured to open at one end surface of the flow path plate 41 in the Y direction.

In the above-described embodiment, a configuration in which the circulation path side flow path cross-sectional area is smaller than the channel side flow path cross-sectional area has been described, but this is not the only possible configuration. For example, the circulation path side flow path cross-sectional area may be equal to or larger than the channel side flow path cross-sectional area.

In the above embodiment, the configuration in which the CP side Y direction outer surface 52f1 serves as the connection surface for the flexible substrate 45 has been described, but this is not the only possible configuration. For example, the CP side Y direction inner surface 52f2 may serve as the connection surface.

In the above embodiment, the portion of the flow path plate 41 that overlaps with the CP-side tail portion 52e in the Y direction is configured as a solid member 41c, but this is not the only possible configuration. For example, the portion of the flow path plate 41 that overlaps with the CP-side tail portion 52e in the Y direction may be configured as a hollow member.

In the above embodiment, the flow path plate 41 is integrally formed from the same material, but the present invention is not limited to this configuration. For example, the flow path plate 41 may be formed from a combination of multiple materials.

In the above-described embodiment, a configuration in which the inkjet head moves relative to the recording medium during printing (so-called shuttle machine) has been described as an example, but the present disclosure is not limited to this configuration. The configuration according to the present disclosure may be adopted in a configuration in which the inkjet head is fixed and the recording medium is moved relative to the inkjet head (so-called fixed head machine).
In the above embodiment, the recording medium P is paper, but the present invention 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 a food product.
In the above-described embodiment, the liquid ejection head is mounted on the liquid ejection recording device, but the present invention is not limited to this configuration. In other words, the liquid ejected from the liquid ejection head is not limited to the liquid that is to be landed on the recording medium, and may be, for example, a medicinal liquid to be mixed in a medicine, a food additive such as a seasoning or a fragrance to be added to food, or an aromatic to be sprayed into the air.
In the above embodiment, the configuration has been described in which the Z direction coincides with the direction of gravity, but the present invention is not limited to this configuration, and the Z direction may be aligned with the horizontal direction.

Second Embodiment
FIG. 9 is an explanatory diagram of a first step of the method for manufacturing a head chip according to the second embodiment.
In the first embodiment described above, an example was given in which the surface of the base adhesive layer on which the main adhesive layer is formed is flat, but this is not limited thereto. For example, as shown in Fig. 9, the base adhesive layer 211 may have a curved or bent shape 211f on the surface of the base adhesive layer 211 on which the main adhesive layer is formed. In the second embodiment, the same reference numerals are used to designate the same components as those in the above-mentioned embodiment, and detailed description thereof will be omitted.

The curved or bent shape 211f includes not only rounded shapes such as curved surfaces, but also irregular shapes with corners in part or in whole (for example, a triangular cross section or a shape with acute corners). The example in Figure 9 shows a curved surface, but this may also include a bent (cornered) shape.

For example, the average length (RSm value) of the elements that form the curved or bent shape 211f may be 200 μm or less. The RSm value means the line roughness defined in JIS (JIS B 0601). The RSm value corresponds to the average pitch (average length between the center of the concave portion and the center of the convex portion) of the concaves and convexes that are the elements that form the curved or bent shape 211f. Although not shown, the second member side adhesive surface to which the first member 101 is adhered in the second member is curved to follow the curved or bent shape 211f of the base adhesive layer 211.

In this embodiment, the adhesive surface suitable for adhesion is a curved or bent shape 211f. Therefore, the pressing plate 220 has a curved transfer surface 220f that follows the curved or bent shape 211f. For example, in the first step, after applying a base adhesive to the extent that it fills in the unevenness, the pressing plate 220 having the curved transfer surface 220f is pressed from above the base adhesive (in the direction of the arrow in Figure 9). The subsequent steps are the same as those in the first embodiment described above, so detailed explanations are omitted.

As described above, the base adhesive layer 211 of this embodiment has a curved or bent shape 211f on the surface of the base adhesive layer 211 on which the main adhesive layer is formed.
According to this configuration, the bonding area between the bonded members 101, 102 is increased compared to when the surface of the base adhesive layer 211 on which the main adhesive layer is formed is a flat surface, and therefore the adhesive strength is further improved.

Third Embodiment
Fig. 10 is an explanatory diagram of a first step of the method for manufacturing a head chip according to the third embodiment. Fig. 11 is an explanatory diagram of the first step according to the third embodiment, following Fig. 10.
In the above-mentioned first embodiment, the upper surface of the base adhesive layer is a plane generally parallel to the lower surface (the second member side adhesive surface) of the second member, but this is not limited thereto. For example, as shown in Fig. 10, the base adhesive layer 311 may have a wedge shape 311w in which the portion of the second member on which the main adhesive layer is formed bites into the surface of the base adhesive layer 311 on which the main adhesive layer is formed. In the third embodiment, the same components as those in the above-mentioned embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

For example, if the first member 101 is a rectangular plate, the wedge shape 311w may extend across the short side or long side of the first member side adhesive surface 101f. In the example of FIG. 10, the wedge shape 311w has a negative taper shape (inverted trapezoid). Although not shown, the portion of the second member where the main adhesive layer is formed has a shape that allows the wedge shape 311w of the base adhesive layer 311 to bite into it.

In this embodiment, the base adhesive layer 311 has a wedge shape 311w that is a negative taper shape (inverted trapezoid). Therefore, the pressing plate 320 has a wedge shape 320w that is a tapered shape (trapezoid) that corresponds to the wedge shape 311w. For example, in the first step, after applying the base adhesive to an extent that fills the unevenness on the first member side adhesive surface 101f and the spaces between the wedge shapes 320w of the pressing plate 320, the pressing plate 320 having the wedge shape 320w that is a tapered shape (trapezoid) is pressed from above the base adhesive.

Then, the pressure plate 320 is separated from the base adhesive. For example, the base adhesive applied to the first member side adhesive surface 101f is cured by heating or ultraviolet irradiation, and then the pressure plate 320 is removed by sliding the pressure plate 320 in the direction of the arrow in FIG. 11. As a result, a base adhesive layer 311 having a wedge shape 311w is formed on the first member side adhesive surface 101f. The subsequent steps are the same as those in the first embodiment described above, and therefore a detailed description will be omitted.

As described above, the base adhesive layer 311 of this embodiment has a wedge shape 311w in which the portion of the second member on which the main adhesive layer is formed bites into the surface of the base adhesive layer 311 on which the main adhesive layer is formed.
According to this configuration, the adhesive strength is improved by the anchor effect between the wedge shape 311w of the base adhesive layer 311 and the portion of the second member where the adhesive layer is formed. In addition, compared to an adhesive structure between simple surfaces (e.g., between flat surfaces), the adhesive area increases by the surface area of the wedge shape 311w, further improving the adhesive strength.

Fourth Embodiment
FIG. 12 is an explanatory diagram of a first step of the method for manufacturing a head chip according to the fourth embodiment.
In the above-mentioned first embodiment, the upper surface of the base adhesive layer is a flat surface without grooves, but the present invention is not limited to this. For example, as shown in Fig. 12, the base adhesive layer 411 may have a clearance groove 411g into which an excess portion of the main adhesive layer fits on the surface of the base adhesive layer 411 on which the main adhesive layer is formed (the upper surface of the base adhesive layer 411). In the fourth embodiment, the same reference numerals are used for the same components as those in the above-mentioned embodiment, and detailed description thereof will be omitted.

For example, when the first member 101 is a rectangular plate, the escape groove 411g may extend across the short side or long side of the first member side adhesive surface. In the example of FIG. 12, the escape groove 411g has a rectangular groove-like concave shape recessed from the upper surface of the base adhesive layer 411 toward the first member 101. Although not shown, the second member side adhesive surface to which the first member 101 is adhered in the second member has a shape that follows the upper surface of the base adhesive layer 411 (specifically, the upper surface of the base adhesive layer 411 other than the escape groove 411g). The second member may have a shape that fits into part of the escape groove 411g.

In this embodiment, the base adhesive layer 411 has a rectangular groove-shaped escape groove 411g. Therefore, the pressure plate 420 has a rectangular protruding protrusion 420p that corresponds to the escape groove 411g. For example, in the first step, after applying the base adhesive to an extent that fills the unevenness on the first member side adhesive surface and the spaces between the protrusions 420p of the pressure plate 420, the pressure plate 420 having the rectangular protruding protrusions 420p is pressed from above the base adhesive. The subsequent steps are the same as those in the first embodiment described above, and therefore detailed explanations are omitted.

As described above, the base adhesive layer 411 of this embodiment has a clearance groove 411g into which the excess portion of the adhesive layer fits on the surface of the base adhesive layer 411 on which the adhesive layer is formed.

With this configuration, the excess portion of the adhesive layer enters the clearance groove 411g, reducing the amount of overflow of the adhesive layer. In addition, air bubbles are permitted to move from the upper surface of the base adhesive layer 411 to the clearance groove 411g, preventing air bubbles from remaining on the upper surface of the base adhesive layer 411. This makes it possible to prevent a decrease in adhesive strength due to air bubbles being present on the surface of the base adhesive layer 411 on which the adhesive layer is formed.

The shape of the escape groove is not limited to the above. For example, by making the escape groove into a wedge shape as shown in FIG. 10, it can also be used as an adhesive escape groove with an anchor effect. In addition, the adhesive area increases by the surface area of the escape groove, further improving the adhesive strength.

Fifth Embodiment
Fig. 13 is an explanatory diagram of an example of a first step of the method for manufacturing a head chip according to the fifth embodiment. Fig. 14 is an explanatory diagram of another example of the first step of the method for manufacturing a head chip according to the fifth embodiment.
In the above-mentioned first embodiment, the upper surface of the base adhesive layer is a flat surface without any irregularities, but the present invention is not limited to this. For example, as shown in Fig. 13 and Fig. 14, the base adhesive layers 511A and 511B may have a recess 511r or a protrusion 511c for positioning the second member on the surface of the base adhesive layers 511A and 511B on which the main adhesive layer is formed (the upper surface of the base adhesive layer 411). In the fifth embodiment, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment, and detailed description thereof will be omitted.

For example, if the first member 101 is a rectangular plate, the recess 511r or the protrusion 511c may be provided in a range not exceeding the short side or not exceeding the long side of the adhesive surface on the first member side. In the example of FIG. 13, the recess 511r has a rectangular concave shape recessed from the upper surface of the base adhesive layer 511A toward the first member 101. In this case, although not shown, the portion of the second member where this adhesive layer is formed has a protrusion that fits into the recess 511r of the base adhesive layer 511A.

On the other hand, in the example of FIG. 14, the convex portion 511c has a rectangular convex shape that protrudes from the upper surface of the base adhesive layer 511B. In this case, although not shown, the portion of the second member where the adhesive layer is formed has a concave portion into which the convex portion 511c of the base adhesive layer 511B fits.

For example, the shape of the recess 511r or the protrusion 511c is not limited to the above. For example, the shape of the recess 511r or the protrusion 511c may be a cross, a circle, a rectangle, or the like in a plan view, or a shape that combines at least two of these. For example, the shape of the recess 511r or the protrusion 511c may be any shape that allows the second member to be fitted into each other so as to be positioned.

In this embodiment, the base adhesive layers 511A and 511B have a recess 511r or a protrusion 511c, so that the pressing plates 520A and 520B have a protrusion 520c corresponding to the recess 511r or a recess 520r corresponding to the protrusion 511c.
For example, in the case where the pressing plate 520A has the convex portion 520c, in the first step, the base adhesive is applied to the extent that it fills the unevenness on the first member side bonding surface and the gaps between the convex portions 520c of the pressing plate 520A, and then the pressing plate 520A having the convex portions 520c is pressed from above the base adhesive. The subsequent steps are the same as those in the first embodiment described above, and therefore detailed explanations are omitted.

On the other hand, if the pressing plate 520B has a recess 520r, in the first step, after applying a base adhesive to the extent that it fills the unevenness on the first member side adhesive surface and the recess 520r of the pressing plate 520B, the pressing plate 520B having the recess 520r is pressed from above the base adhesive. The subsequent steps are the same as those in the first embodiment described above, so detailed explanations are omitted.

As described above, the base adhesive layers 511A, 511B of this embodiment have the recesses 511r or the protrusions 511c for positioning the second member on the surfaces of the base adhesive layers 511A, 511B on which the main adhesive layer is formed.
According to this configuration, the recess 511r or the protrusion 511c of the base adhesive layers 511A and 511B eliminates the need to prepare a separate mark for positioning the second member. Furthermore, since positioning by fitting is possible, positioning by manually aligning the marks is not required. Therefore, accurate positioning can be easily achieved.

For example, if the recess 511r or the protrusion 511c is provided in a range equal to or less than the short side or long side of the adhesive surface on the first member side, the pressing plates 520A, 520B are larger than the first member 101, making it easier to fix and hold the first member 101. Therefore, when pressing the base adhesive against the adhesive surface on the first member side, precise positioning of the pressing plates 520A, 520B is also easy.

The shape of the recesses or protrusions of the base adhesive layer is not limited to the above. For example, in the case of uniaxial positioning, the shape of the recesses or protrusions can be made to cross the short or long side of the adhesive surface on the first component side as shown in Figure 12, and can also be used as an adhesive escape groove.

Sixth Embodiment
FIG. 15 is an explanatory diagram of an adhesive layer that bonds a first member and a second member according to the sixth embodiment.
In the first embodiment described above, an example was given in which the materials for forming the base adhesive layer and the main adhesive layer were not limited, but this is not limiting. For example, as shown in Fig. 15, the materials for forming the base adhesive layer 611 and the main adhesive layer 612 may be the same adhesive. In the sixth embodiment, the same reference numerals are used for the same components as those in the above-mentioned embodiments, and detailed description thereof will be omitted.

For example, the materials forming the base adhesive layer 611 and the main adhesive layer 612 do not have to be completely the same, and may be substantially the same. For example, the components of the materials forming the base adhesive layer 611 and the main adhesive layer 612 may be adjusted so that the viscosity of the base adhesive (corresponding to the viscosity of the base adhesive layer 611 when uncured) is lower than the viscosity of the main adhesive (corresponding to the viscosity of the main adhesive layer 612 when uncured).

As described above, the materials forming the base adhesive layer 611 and the main adhesive layer 612 in this embodiment are the same adhesive.
According to this configuration, the base adhesive layer 611 and the main adhesive layer 612 are made of adhesives of similar substances, so that they are compatible with each other and the adhesives are more compatible with each other. Therefore, the base adhesive layer 611 can be applied thinly to the first member 601, and air bubbles and the like can be easily released after application. In addition, by pressing the applied base adhesive with a pressure plate, the base adhesive can be spread to the depths of the curved unevenness (rough surface unevenness) of the surface of the first member 601. Therefore, the compatibility between the first member 601 and the base adhesive can be improved compared to application methods such as thick coating.

Seventh Embodiment
Fig. 16 is an explanatory diagram of an adhesive layer that bonds a first member and a second member according to the seventh embodiment. Fig. 17 is an explanatory diagram of a protruding portion of the adhesive layer according to the seventh embodiment.
In the above-mentioned fourth embodiment, an example was described in which the surface of the base adhesive layer on which the main adhesive layer is formed has a clearance groove into which the excess portion of the main adhesive layer fits, but this is not limited to this. For example, as shown in Figures 16 and 17, a configuration may be made in which an adhesive protrusion portion 713 is formed inside the grooves machined in the first member 701 and the second member 702. In the seventh embodiment, the same components as those in the above-mentioned embodiments are given the same reference numerals, and detailed description thereof will be omitted.

The examples in Figures 16 and 17 show a first member 701 having a first groove 701g that functions as a pump chamber, and a second member 702 having a second groove 702g that functions as a common flow path. For example, a base adhesive is applied to the first member side bonding surface and the second member side bonding surface using a pressure plate and cured, and then the first member 701 and the second member 702 are bonded via the main adhesive layer 712. Then, a protruding portion 713 is formed inside the grooves 701g, 702g machined in the first member 701 and the second member 702.

For example, if the adhesive is applied after the base adhesive layer 711 has hardened, the adhesive will flow and overflow along the hardened portions (overflowing portions of the base adhesive layer 711) inside the grooves 701g, 702g. This reduces the amount of adhesive that wraps around the walls inside the grooves 701g, 702g in the first member 701 and the second member 702, causing the overflowing portions 713 to grow three-dimensionally. This makes it difficult for adhesive to form on the walls inside the grooves 701g, 702g, making it easier to remove the hardened overflowing portions 713 in a later process.

As described above, the head chip of this embodiment is configured so that the adhesive protrusion portion 713 is formed inside the grooves 701 g and 702 g machined in the first member 701 and the second member 702 .
According to this configuration, the excess portion of the adhesive is formed inside the grooves 701g and 702g as a protruding portion 713. Therefore, the amount of adhesive (base adhesive and main adhesive) applied to the bonding surfaces between the first member 701 and the second member 702 can be kept as small as possible.

Eighth Embodiment
Fig. 18 is a perspective view of the head chip according to the eighth embodiment. Fig. 19 is a perspective view of a step of a method for manufacturing the head chip according to the eighth embodiment. Fig. 20 is a plan view of the head chip according to the eighth embodiment.
In the above-described first embodiment, an example in which the head chip includes the actuator plate 51 and the cover plate 52 has been described, but the present invention is not limited to this. For example, as shown in Fig. 18, the head chip 840 may include an actuator plate 851 (corresponding to a first member), a pair of flow path members 852 (corresponding to a second member), and a nozzle plate 844. In the eighth embodiment, the same reference numerals are used for configurations similar to those in the above-described embodiments, and detailed description thereof will be omitted.

In the examples of Figures 18 to 20, the actuator plate 851 has an ACT groove 851g in which an electrode is formed. The pair of flow path members 852 have a COM groove 852g that functions as an ink flow path and a pump chamber. For example, if the electrodes are formed by double-sided deposition or the like, the cut surface of the forming member 851M of the actuator plate 851 may be bonded to the cut surface of the forming member 852M of the pair of flow path members 852, and then the thick portion (part other than the groove) at the bottom of Figure 19 may be polished.

For example, in the first step, a base adhesive layer is formed as a base on the surfaces (cut surfaces) of the actuator plate 851 and the flow path member 852 that constitute the head chip 840. After the first step, in the second step, a main adhesive layer is formed between the base adhesive layers of the actuator plate 851 and the flow path member 852. In the first step, a pressure plate is used to press the base adhesive against the surfaces (cut surfaces) of the actuator plate 851 and the flow path member 852.

As described above, according to the configuration of this embodiment, even if the surfaces (cut surfaces) of the actuator plate 851 and the flow path member 852 constituting the head chip 840 are rough as described above, the base adhesive layer can be made to penetrate deep into the unevenness of each surface by pressing the base adhesive against each surface of the actuator plate 851 and the flow path member 852 using the above-mentioned pressing plate. Therefore, it is possible to suppress the reduction in the adhesion area between the adherend members (actuator plate 851 and flow path member 852). Therefore, there is a great practical benefit in suppressing the decrease in adhesive strength. For example, even in a region where strict alignment is performed so that the ACT groove 851g and the COM groove 852g are linear with each other in the actuator plate 851 and the flow path member 852, the decrease in adhesive strength can be suppressed.

In the first step, the base adhesive layer is not limited to being formed as a base on the surfaces (cut surfaces) of the actuator plate 851 and each flow path member 852 constituting the head chip 840. For example, in the first step, a base adhesive layer may be formed as a base on the surfaces of the actuator plate 851 and the nozzle plate 844 constituting the head chip 840. In this case, after the first step, in the second step, the main adhesive layer may be formed between the base adhesive layers of the actuator plate 851 and the nozzle plate 844. In the first step, the base adhesive may be pressed against the surfaces of the actuator plate 851 and the nozzle plate 844 using a pressure plate.

The head chip is not limited to a configuration including an actuator plate, a pair of flow path members, and a nozzle plate. For example, the head chip may be configured to include an actuator plate and a cover plate without including a nozzle plate. For example, the head chip may be configured to include an actuator plate, a cover plate, and a nozzle plate. For example, the head chip may be configured as a rooftop (ceiling-driven) or thermal type. For example, the configuration of the head chip can be changed according to the design specifications.

Although preferred embodiments of the present disclosure have been described and illustrated above, it should be understood that these are illustrative of the present disclosure and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present disclosure. Thus, the present disclosure should not be considered as limited by the foregoing description, but rather by the scope of the claims.

1 ... Printer (liquid jet recording device)
5... Inkjet head (liquid jet head)
33 ... carriage 40A, 40B ... head chip 51 ... actuator plate 54 ... ejection channel (channel through which liquid passes)
101 ... first member 101f ... first member side adhesive surface (adhesive surface of the first member to which the second member is adhered)
102 ... second member 111 ... base adhesive layer 111f ... flat surface 112 ... main adhesive layer 120 ... pressure plate 211 ... base adhesive layer 211f ... curved or bent shape 220 ... pressure plate 311 ... base adhesive layer 311w ... wedge shape 320 ... pressure plate 411 ... base adhesive layer 411g ... relief groove 420 ... pressure plates 511A, B ... base adhesive layer 511c ... convex portion 511r ... concave portion 520A, B ... pressure plate 601 ... first member 611 ... base adhesive layer 612 ... main adhesive layer 701 ... first member 702 ... second member 711 ... base adhesive layer 712 ... main adhesive layer 840 ... head chip 851 ... actuator plate (first member)
852 ... Flow path member (second member)
844 ... Nozzle plate

Claims (9)

A plurality of members are provided,
Two members to be bonded to each other among the plurality of members are a first member and a second member,
a base adhesive layer formed as a base on an adhesive surface of the first member to which the second member is adhered;
a main adhesive layer formed between the base adhesive layer and the second member,
The viscosity of the base adhesive layer when uncured is lower than the viscosity of the main adhesive layer when uncured.
Head chip. The base adhesive layer has a flat surface on the surface of the base adhesive layer on which the main adhesive layer is formed.
The head chip according to claim 1 . The base adhesive layer has a curved or bent shape on a surface of the base adhesive layer on which the main adhesive layer is formed.
The head chip according to claim 1 . The base adhesive layer has a wedge shape in which a portion of the second member on which the main adhesive layer is formed is wedged into a surface of the base adhesive layer on which the main adhesive layer is formed.
The head chip according to claim 1 . The base adhesive layer has a clearance groove into which an excess portion of the main adhesive layer fits on a surface of the base adhesive layer on which the main adhesive layer is formed.
The head chip according to claim 1 . The base adhesive layer has a concave or convex portion for positioning the second member on a surface of the base adhesive layer on which the main adhesive layer is formed.
The head chip according to claim 1 . The head chip according to any one of claims 1 to 3 is provided.
Liquid injection head. The liquid jet head according to claim 7 ,
A carriage to which the liquid ejection head is attached.
Liquid jet recording device. A method for manufacturing a head chip having a plurality of members,
Two members to be bonded to each other among the plurality of members are a first member and a second member,
a first step of forming a base adhesive layer as a base on an adhesive surface of the first member to which the second member is adhered;
A second step of forming a main adhesive layer between the base adhesive layer and the second member after the first step,
In the first step, the adhesive that will become the base adhesive layer is pressed against the adhesive surface of the first member using a pressing plate.
A method for manufacturing a head chip.

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