JP2020151857A - Liquid jet head, liquid jet device and electronic device - Google Patents

Abstract

To provide a liquid jet head, in which poor adhesion between a first substrate and a second substrate and deformation of the first substrate in a step of installing a wiring substrate can be suppressed.SOLUTION: The liquid jet head is equipped with: a first substrate including a first surface and a second surface at the opposite side of the first surface; a pressure chamber communicated with a nozzle for jetting liquid; a second substrate including a mounting surface opposing to the first surface with an interval; a first adhesion layer interposed between the first surface and the mounting surface; and a flexible wiring substrate jointed to a mounting region, a portion of the second surface. The mounting region includes a first region overlapping with the first adhesion layer in a planar view, and a second region not overlapping with the first adhesion layer in a planar view.SELECTED DRAWING: Figure 6

Description

The present invention relates to a liquid injection head, a liquid injection device, and an electronic device.

Conventionally, electronic devices such as a liquid injection head composed of a plurality of substrates bonded to each other have been proposed. For example, Patent Document 1 discloses an inkjet head including a head substrate having a flow path formed inside and a wiring substrate crimped to the head substrate via an adhesive resin layer. The wiring board is composed of a flat plate-shaped substrate body and FPCs (Flexible Printed Circuits) mounted on the surface of the substrate body.

Japanese Unexamined Patent Publication No. 2013-095088

In the configuration of Patent Document 1, an adhesive resin layer is formed over the entire space overlapping the FPC in a plan view in the gap between the substrate body and the head substrate. Therefore, in the process of crimping the substrate body to the head substrate, the pressure between the substrate body or the head substrate and the adhesive resin layer may be insufficient, and as a result, the substrate body and the head substrate may not be sufficiently bonded. On the other hand, in the configuration in which the adhesive resin layer is not formed in the space overlapping the FPC in a plan view in the gap between the substrate body and the head substrate, the substrate body is deformed in the process of crimping the FPC to the substrate body, and damage such as cracks is caused to the substrate. It may occur on the main body.

In order to solve the above problems, the liquid injection head according to one aspect of the present invention includes a first substrate including a first surface and a second surface opposite to the first surface, and a nozzle for injecting liquid. A second substrate including a pressure chamber that communicates with the first surface and a mounting surface that faces the first surface with a gap, a first adhesive layer that is interposed between the first surface and the mounting surface, and the second. A flexible wiring substrate joined to a mounting region that is a part of a surface is provided, and the mounting region includes a first region that overlaps the first adhesive layer in a plan view and the first adhesive layer. Includes a second region that does not overlap in plan view.

The liquid injection device according to one aspect of the present invention includes a liquid injection head that injects liquid from a nozzle and a control unit that controls the liquid injection head, and the liquid injection head has a first surface and the first surface. A first substrate including a second surface opposite to one surface, a second substrate including a pressure chamber communicating with a nozzle for injecting a liquid, and a mounting surface facing the first surface with a gap, and the above. The mounting area comprises a first adhesive layer interposed between the first surface and the mounting surface, and a flexible wiring substrate bonded to a mounting area that is a part of the second surface. Includes a first region that overlaps the first adhesive layer in a plan view and a second region that does not overlap the first adhesive layer in a plan view.

An electronic device according to one aspect of the present invention includes a first substrate including a first surface and a second surface opposite to the first surface, and a mounting surface facing the first surface with a gap. A second substrate, a first adhesive layer interposed between the first surface and the mounting surface, and a flexible wiring board bonded to a mounting region that is a part of the second surface are provided. However, the mounting region includes a first region that overlaps the first adhesive layer in a plan view and a second region that does not overlap the first adhesive layer in a plan view.

It is a block diagram which illustrates the structure of the liquid injection apparatus which concerns on 1st Embodiment. It is a block diagram which illustrates the functional structure of the liquid injection device. It is an exploded perspective view of the liquid injection head. It is sectional drawing of the liquid injection head. It is sectional drawing of the wiring formed on the relay board. It is a top view in the vicinity of the mounting area. It is sectional drawing of bb line in FIG. FIG. 6 is a cross-sectional view taken along the line cc in FIG. It is a flowchart which illustrates the manufacturing process of a liquid injection head. It is a top view near the mounting area in 2nd Embodiment. It is a top view near the mounting area in 3rd Embodiment. It is a top view in the vicinity of the mounting area in the modification. It is a top view in the vicinity of the mounting area in the modification.

A: First Embodiment In the following description, it is assumed that the X-axis, the Y-axis, and the Z-axis are orthogonal to each other. As illustrated in FIG. 3, one direction along the X-axis when viewed from an arbitrary point is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. Similarly, the directions opposite to each other along the Y axis from an arbitrary point are described as the Y1 direction and the Y2 direction, and the directions opposite to each other along the Z axis from an arbitrary point are described as the Z1 direction and the Z2 direction. .. The XY plane including the X-axis and the Y-axis corresponds to a horizontal plane. The Z-axis is an axis along the vertical direction, and the Z1 direction corresponds to the lower part in the vertical direction.

FIG. 1 is a configuration diagram illustrating the liquid injection device 100 according to the first embodiment. The liquid injection device 100 of the first embodiment is an inkjet printing device that injects droplets of ink, which is an example of liquid, onto the medium 12. The medium 12 is typically printing paper. However, a print target of any material such as a resin film or a cloth is used as the medium 12. As illustrated in FIG. 1, a liquid container 14 for storing ink is installed in the liquid injection device 100. For example, a cartridge that can be attached to and detached from the liquid injection device 100, a bag-shaped ink pack made of a flexible film, or an ink tank that can be refilled with ink is used as the liquid container 14.

As illustrated in FIG. 1, the liquid injection device 100 includes a control unit 20, a transfer mechanism 22, a moving mechanism 24, and a liquid injection head 26. The control unit 20 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and controls each element of the liquid injection device 100. The control unit 20 is an example of a “control unit”.

The transport mechanism 22 transports the medium 12 along the Y axis under the control of the control unit 20. The moving mechanism 24 reciprocates the liquid injection head 26 along the X axis under the control of the control unit 20. The moving mechanism 24 of the first embodiment includes a substantially box-shaped transport body 242 that houses the liquid injection head 26, and an endless belt 244 to which the transport body 242 is fixed. A configuration in which a plurality of liquid injection heads 26 are mounted on the transport body 242, or a configuration in which the liquid container 14 is mounted on the transport body 242 together with the liquid injection head 26 can also be adopted.

The liquid injection head 26 ejects the ink supplied from the liquid container 14 from a plurality of nozzles onto the medium 12 under the control of the control unit 20. An image is formed on the surface of the medium 12 by each liquid injection head 26 ejecting ink onto the medium 12 in parallel with the transfer of the medium 12 by the transfer mechanism 22 and the repetitive reciprocation of the transfer body 242.

FIG. 2 is a block diagram illustrating a functional configuration of the liquid injection device 100. The transport mechanism 22 and the moving mechanism 24 are not shown for convenience. As illustrated in FIG. 2, the control unit 20 of the first embodiment supplies a plurality of signals including the drive signal D and a predetermined reference voltage Vbs to the liquid injection head 26. The drive signal D is a voltage signal whose voltage fluctuates in a predetermined cycle. The drive signal D and the reference voltage Vbs are supplied from the control unit 20 to the liquid injection head 26 via the wiring board 70 mounted on the liquid injection head 26.

As illustrated in FIG. 2, the liquid injection head 26 of the first embodiment includes a plurality of piezoelectric elements 40 corresponding to the plurality of nozzles, and a drive circuit 28 for driving each of the plurality of piezoelectric elements 40. .. The drive circuit 28 includes a plurality of switch SWs corresponding to the plurality of piezoelectric elements 40, respectively. Each of the plurality of switch SWs is composed of a transfer gate that switches the supply / stop of the drive signal D to the piezoelectric element 40 according to various control signals. The piezoelectric element 40 is deformed by the supply of the drive signal D.

FIG. 3 is an exploded perspective view of the liquid injection head 26, and FIG. 4 is a cross-sectional view taken along the line aa in FIG. In addition, in order to avoid complication of the drawing, hatching for each element is omitted in FIG.

As illustrated in FIG. 3, the liquid injection head 26 includes a plurality of nozzles N arranged along the Y axis. The plurality of nozzles N are divided into a first row La and a second row Lb which are arranged side by side at intervals along the X axis. Each of the first row La and the second row Lb is a set of a plurality of nozzles N linearly arranged along the Y axis. As can be understood from FIG. 4, in the liquid injection head 26 of the first embodiment, the elements related to each nozzle N in the first row La and the elements related to each nozzle N in the second row Lb are formed on the reference plane O. It is a structure that is installed substantially symmetrically with the. Therefore, in the following description, the elements corresponding to the first column La will be mainly described, and the description of the elements corresponding to the second column Lb will be omitted as appropriate. The reference plane O is a plane parallel to the YY plane.

As illustrated in FIGS. 3 and 4, the liquid injection head 26 of the first embodiment includes a flow path structure 30, a plurality of piezoelectric elements 40, a housing portion 50, a relay board 60, and a wiring board 70. .. The flow path structure 30 is an example of the “second substrate”, and the relay substrate 60 is an example of the “first substrate”.

The flow path structure 30 is a flat plate-like structure in which a flow path for supplying ink to each of the plurality of nozzles N is formed inside. The flow path structure 30 of the first embodiment is composed of a first flow path substrate 31, a second flow path substrate 32, a diaphragm 33, a nozzle plate 34, and a vibration absorbing body 35. Each member constituting the flow path structure 30 is a long plate-shaped member along the Y axis. The second flow path board 32 and the housing portion 50 are installed on the surface of the first flow path board 31 in the Z2 direction. On the other hand, the nozzle plate 34 and the vibration absorbing body 35 are installed on the surface of the first flow path substrate 31 in the Z1 direction. The members constituting the flow path structure 30 are fixed to each other by, for example, an adhesive.

The nozzle plate 34 is a plate-shaped member in which a plurality of nozzles N constituting the first row La and the second row Lb are formed. Each of the plurality of nozzles N is a circular through hole for ejecting ink. The nozzle plate 34 is manufactured by processing a silicon (Si) single crystal substrate using, for example, semiconductor manufacturing techniques such as photolithography and etching. However, a known material or manufacturing method can be arbitrarily adopted for manufacturing the nozzle plate 34.

As illustrated in FIGS. 3 and 4, the first space 311, a plurality of supply flow paths 312, a plurality of communication flow paths 313, and a relay flow path 314 are formed in the first flow path substrate 31. The first space 311 is an opening formed in a long shape along the Y axis in a plan view from the Z direction. The supply flow path 312 and the communication flow path 313 are through holes formed for each nozzle N. The relay flow path 314 is a space formed in a long shape along the Y axis over the plurality of nozzles N, and allows the first space 311 and the plurality of supply flow paths 312 to communicate with each other. Each of the plurality of communication flow paths 313 overlaps one nozzle N corresponding to the communication flow path 313 in a plan view.

As illustrated in FIGS. 3 and 4, a plurality of pressure chambers C are formed in the second flow path substrate 32. The pressure chamber C is formed for each nozzle N and is a long space along the X axis in a plan view. The plurality of pressure chambers C are arranged along the Y axis. The first flow path substrate 31 and the second flow path substrate 32 are manufactured by processing a silicon single crystal substrate by using, for example, a semiconductor manufacturing technique, similarly to the nozzle plate 34 described above. However, known materials and manufacturing methods can be arbitrarily adopted for manufacturing the first flow path substrate 31 and the second flow path substrate 32.

As illustrated in FIG. 3, an elastically deformable diaphragm 33 is installed on the surface of the second flow path substrate 32 opposite to the first flow path substrate 31. The diaphragm 33 is a plate-shaped member formed in a long rectangular shape along the Y-axis in a plan view from the direction of the Z-axis. As can be understood from FIGS. 3 and 4, the pressure chamber C is a space located between the first flow path substrate 31 and the diaphragm 33. As illustrated in FIG. 4, the pressure chamber C communicates with the communication flow path 313 and the supply flow path 312. Therefore, the pressure chamber C communicates with the nozzle N via the communication flow path 313 and also communicates with the liquid storage chamber R via the supply flow path 312 and the relay flow path 314.

The housing portion 50 of FIG. 3 is a case for storing ink supplied to a plurality of pressure chambers C, and is formed by, for example, injection molding of a resin material. A supply port 51 and a second space 52 are formed in the housing portion 50. The supply port 51 is a pipeline in which ink is supplied from the liquid container 14, and communicates with the second space 52. As illustrated in FIG. 4, the first space 311 of the first flow path substrate 31 and the second space 52 of the housing portion 50 communicate with each other. The space composed of the first space 311 and the second space 52 functions as a liquid storage chamber R for storing ink supplied to the plurality of pressure chambers C. The ink supplied from the liquid container 14 and passing through the supply port 51 is stored in the liquid storage chamber R. The ink stored in the liquid storage chamber R branches from the relay flow path 314 to each supply flow path 312, and is supplied and filled in parallel to the plurality of pressure chambers C. The vibration absorber 35 is a flexible film that constitutes the wall surface of the liquid storage chamber R, and absorbs pressure fluctuations of ink in the liquid storage chamber R.

As illustrated in FIGS. 3 and 4, a piezoelectric element 40 is formed in each pressure chamber C on the surface (hereinafter referred to as “mounting surface”) Fa in the Z2 direction of the flow path structure 30. Specifically, the mounting surface Fa is the surface of the diaphragm 33. The piezoelectric element 40 is a long passive element along the X axis in a plan view. A plurality of piezoelectric elements 40 are arranged along the Y axis. Each piezoelectric element 40 changes the pressure in the pressure chamber C by deforming according to the applied voltage. The piezoelectric element 40 changes the pressure in the pressure chamber C, so that the ink in the pressure chamber C is ejected from the nozzle N.

As illustrated in FIG. 4, each piezoelectric element 40 is a structure in which the first electrode 41, the piezoelectric layer 42, and the second electrode 43 are laminated in the above order in the Z2 direction. The first electrode 41 is an individual electrode individually formed for each piezoelectric element 40. Specifically, a plurality of long first electrodes 41 along the X axis are arranged along the Y axis at intervals from each other. The piezoelectric layer 42 covers the first electrode 41. For example, the piezoelectric layer 42 is formed of a known piezoelectric material such as lead zirconate titanate (Pb (Zr, Ti) O ₃ ). The second electrode 43 covers the piezoelectric layer 42. The second electrode 43 is a common electrode that is continuous over the plurality of piezoelectric elements 40. The piezoelectric element 40 is deformed by supplying the drive signal D to the first electrode 41.

As illustrated in FIGS. 3 and 4, the relay board 60 is joined to the mounting surface Fa of the flow path structure 30. The flow path structure 30 and the relay board 60 are joined to each other by an adhesive layer 67. The adhesive layer 67 is formed of, for example, a photosensitive adhesive. The relay board 60 is a plate-shaped member including a first surface F1 and a second surface F2. The first surface F1 and the second surface F2 are located opposite to each other. Specifically, the first surface F1 is the surface of the relay board 60 in the Z1 direction, and the second surface F2 is the surface of the relay board 60 in the Z2 direction. As illustrated in FIG. 4, the first surface F1 of the relay board 60 and the mounting surface Fa of the flow path structure 30 face each other with a gap. The drive circuit 28 is mounted on the second surface F2 of the relay board 60. The drive circuit 28 is an IC chip that is long in the Y-axis direction.

The relay board 60 is a wiring board for electrically connecting the drive circuit 28 and the plurality of piezoelectric elements 40. As illustrated in FIG. 4, a plurality of wirings W (W1, W2, W3, W4) are formed on the relay board 60. The plurality of wirings W include the first wiring W1, the second wiring W2, and the third wiring W3. The first wiring W1 and the second wiring W2 are formed for each piezoelectric element 40. The first wiring W1 and the third wiring W3 are formed on the first surface F1, and the second wiring W2 is formed on the second surface F2. The first wiring W1 and the second wiring W2 are electrically connected to each other through a through hole H penetrating the relay board 60 along the Z axis. The drive signal D output by the drive circuit 28 for each piezoelectric element 40 is supplied to the second wiring W2. The reference voltage Vbs illustrated in FIG. 2 is supplied to the third wiring W3 from the wiring board 70.

FIG. 5 is a cross-sectional view of each wiring W (W1, W2, W3, W4) on the relay board 60. The configuration of the cross section orthogonal to the extending direction of each wiring W is illustrated in FIG. As illustrated in FIG. 5, a groove 63 is formed on the surface F (F1, F2) of the relay substrate 60. The groove 63 is a recess having a rectangular cross section that is recessed with respect to the surface F. Each wiring W is composed of a stack of a first layer 61 and a second layer 62. The first layer 61 is a conductive pattern formed of a low resistance metal such as copper (Cu). As illustrated in FIG. 5, the first layer 61 is formed inside the groove 63. The second layer 62 is a conductive pattern that covers the first layer 61. Specifically, the second layer 62 is formed of an adhesive layer formed on the surface of the first layer 61 with a metal such as titanium (Ti) or tungsten (W), and an adhesive layer made of a metal such as gold (Au). It is composed of a laminate with a wiring layer formed on the surface of. The adhesion layer is a conductive layer for improving the adhesion between the first layer 61 and the wiring layer. As described above, each wiring W formed on the relay board 60 includes a portion formed inside the groove portion 63. Therefore, there is an advantage that the resistance of the wiring W is reduced as compared with the configuration in which the wiring W is formed only by the conductive pattern formed on the surface F of the relay board 60. In the first embodiment, the structure of FIG. 5 is adopted for both the wiring W (W1, W3) on the first surface F1 and the wiring W (W2, W4) on the second surface F2, but the first surface. The structure of FIG. 5 may be adopted only for one of the wiring W on the F1 and the wiring W on the second surface F2.

As illustrated in FIG. 4, a connection terminal 65 and a connection terminal 66 are formed on the first surface F1 of the relay board 60. The connection terminal 65 is formed for each piezoelectric element 40. The connection terminal 65 and the connection terminal 66 are resin core bumps having a structure in which protrusions formed of a resin material are coated with a conductive layer.

The connection terminal 65 is connected to the first wiring W1 on the first surface F1. In a state where the relay board 60 is joined to the flow path structure 30, the connection terminal 65 comes into contact with the first electrode 41 on the mounting surface Fa of the flow path structure 30. Therefore, the drive signal D output by the drive circuit 28 is supplied to the first electrode 41 of the piezoelectric element 40 via the second wiring W2, the through hole H, the first wiring W1, and the connection terminal 65.

The connection terminal 66 is connected to the third wiring W3 on the first surface F1. In a state where the relay board 60 is joined to the flow path structure 30, the connection terminal 66 comes into contact with the second electrode 43 on the mounting surface Fa of the flow path structure 30. Therefore, the reference voltage Vbs supplied from the wiring board 70 to the third wiring W3 is supplied to the second electrode 43 of the piezoelectric element 40 via the connection terminal 66.

As described above, the wiring board 70 of FIG. 3 is a mounting component for electrically connecting the control unit 20 and the liquid injection head 26. FIG. 6 is a plan view of the liquid injection head 26 in which the vicinity of the wiring board 70 is enlarged. 7 is a cross-sectional view taken along the line bb in FIG. 6, and FIG. 8 is a cross-sectional view taken along the line cc in FIG.

As illustrated in FIGS. 6 to 8, a plurality of wiring boards 70 are formed on a flexible base body 71 formed of a film made of a resin material and a plurality of surfaces (hereinafter referred to as “joining surfaces”) Fb of the base body 71. The wiring 72 is provided. Although the wiring 72 in FIG. 6 is actually located behind the substrate 71, the outer shape of each wiring 72 is shown by a solid line for convenience in FIG. The wiring board 70 is composed of flexible connecting components such as FPC (Flexible Printed Circuits) or FFC (Flexible Flat Cable). The wiring board 70 is joined to the second surface F2 of the relay board 60. Specifically, as illustrated in FIGS. 6 to 8, a part of the joint surface Fb on the base 71 of the wiring board 70 is formed in a part of the region (hereinafter referred to as “mounting region”) A on the second surface F2. Be joined. As described above with reference to FIG. 2, the drive signal D and the reference voltage Vbs are supplied to the liquid injection head 26 via the wiring board 70.

As illustrated in FIGS. 6 to 8, the plurality of wirings 72 of the wiring board 70 are formed on the joint surface Fb of the substrate 71 at intervals in the X-axis direction. Each wire 72 extends along the Y axis. The Y-axis is an example of the "first axis". On the other hand, on the second surface F2 of the relay board 60, a plurality of fourth wirings W4 corresponding to the plurality of wirings 72 of the wiring board 70 are formed. The plurality of fourth wirings W4 include a wiring for supplying the drive signal D to the drive circuit 28 and a wiring for supplying the reference voltage Vbs to the third wiring W3. The fourth wiring W4 is formed on the second surface F2 together with the above-mentioned second wiring W2. As described above with reference to FIG. 5, the fourth wiring W4 is composed of a stack of the first layer 61 and the second layer 62. That is, a part or all of the fourth wiring W4 is formed inside the groove portion 63 formed on the second surface F2.

As illustrated in FIG. 7, the wiring board 70 and the relay board 60 are joined via the second adhesive layer 82. The second adhesive layer 82 is interposed between the joint surface Fb of the wiring board 70 and the second surface F2 of the relay board 60. The region where the second adhesive layer 82 is formed on the second surface F2 may be referred to as a mounting region A. The second adhesive layer 82 is a non-conductive adhesive that does not contain a conductor such as conductive particles. The non-conductive adhesive is, for example, a non-conductive adhesive paste (NCP) or a non-conductive adhesive film (NCF). That is, the joint surface Fb and the second surface F2 are joined to each other by the second adhesive layer 82 in a state where the surface of the wiring 72 and the surface of the fourth wiring W4 are in close contact with each other. However, an anisotropic conductive adhesive in which a plurality of conductive particles are dispersed may be used for joining the wiring board 70 and the relay board 60. The anisotropic conductive adhesive is, for example, an anisotropic conductive film (ACF: Anisotropic Conductive Film) or an anisotropic conductive paste (ACP: Anisotropic Conductive Paste). The wiring 72 and the fourth wiring W4 may be electrically connected by soldering.

As illustrated in FIGS. 7 and 8, the first adhesive layer 81 is interposed in the gap between the first surface F1 of the relay board 60 and the mounting surface Fa of the flow path structure 30. The relay board 60 and the flow path structure 30 are joined to each other by the first adhesive layer 81 and the adhesive layer 67. The first adhesive layer 81 is formed together with the above-mentioned adhesive layer 67 by, for example, a photosensitive adhesive. Therefore, there is an advantage that the first adhesive layer 81 can be formed in a desired shape with high accuracy.

As illustrated in FIGS. 6 to 8, the first adhesive layer 81 is composed of a plurality of adhesive portions 811. The plurality of adhesive portions 811 are arranged side by side at intervals in the Y-axis direction. Each adhesive portion 811 extends linearly along the X axis. That is, each adhesive portion 811 is formed along a direction in which the wiring 72 intersects the extending direction. Specifically, as illustrated in FIG. 6, each adhesive portion 811 is a series of portions that overlap the plurality of wirings 72 of the wiring board 70 in a plan view. That is, each adhesive portion 811 is continuous along the X axis over a plurality of wirings 72 in a plan view. As can be understood from the above description, each of the plurality of wirings 72 has a first portion 72a that overlaps the first adhesive layer 81 in a plan view and a first adhesive layer 81 in a plan view, as illustrated in FIG. Includes a second portion 72b that does not overlap. The first portion 72a and the second portion 72b are arranged alternately along the Y axis. The film thickness of the first portion 72a and the film thickness of the second portion 72b are equal to each other. That is, the wiring 72 is formed to have a constant film thickness over the first portion 72a and the second portion 72b. In other words, the height of the surface of the wiring 72 is equal between the first portion 72a and the second portion 72b. According to the above configuration, there is an advantage that the deformation of the relay substrate 60 or the substrate 71 can be suppressed as compared with the configuration in which the film thickness of the wiring 72 is different between the first portion 72a and the second portion 72b.

Since the first adhesive layer 81 is formed in the above shape, the mounting region A is the first adhesive layer A1 that overlaps the first adhesive layer 81 in a plan view, as illustrated in FIGS. 6 and 8. It includes a second region A2 that does not overlap the layer 81 in a plan view. Each of the first region A1 and the second region A2 is a region extending linearly along the X axis. The first region A1 and the second region A2 are arranged alternately along the Y axis. That is, the first adhesive layer 81 overlaps only a part of the mounting region A in a plan view.

FIG. 9 is an explanatory diagram of the manufacturing process of the liquid injection head 26. As illustrated in FIG. 9, first, in step S1, a photosensitive adhesive is applied to the mounting surface Fa of the flow path structure 30. In step S2 after the execution of step S1, the adhesive layer 67 and the first adhesive layer 81 are formed by patterning the adhesive.

In step S3 after the execution of step S2, the relay substrate 60 is placed on the surface of the flow path structure 30 so that the first surface F1 faces the mounting surface Fa with the adhesive layer 67 and the first adhesive layer 81 sandwiched between them. Will be installed. In step S4 after the execution of step S3, the relay substrate 60 is crimped to the flow path structure 30 in the above state. In the process of crimping the relay substrate 60, the adhesive is cured by exposure. Through the above steps, the flow path structure 30 and the relay substrate 60 are joined by the adhesive layer 67 and the first adhesive layer 81.

In step S5 after the execution of step S4, the wiring board 70 is joined to the second surface F2 of the relay board 60. Specifically, the wiring board 70 is heated before the relay board 60 with the second adhesive layer 82 interposed between the joint surface Fb of the wiring board 70 and the second surface F2 of the relay board 60. Be pressed. Through the above steps, the wiring board 70 and the relay board 60 are joined via the second adhesive layer 82.

As described above, in the first embodiment, the mounting region A of the wiring board 70 includes the second region A2 that does not overlap with the first adhesive layer 81. That is, the first adhesive layer 81 is formed so as to partially overlap the mounting region A. Therefore, as compared with the configuration in which the first adhesive layer 81 is formed over the entire mounting area A, in the step S4 of joining the flow path structure 30 and the relay board 60, the flow path structure 30 or the relay board 60 and the first 1 Sufficient pressure acts between the adhesive layer 81 and the adhesive layer 81. Therefore, the flow path structure 30 and the relay board 60 can be firmly joined by the first adhesive layer 81.

On the other hand, in the configuration in which the first adhesive layer 81 does not overlap the mounting region A, the relay board 60 can be deformed in the Z1 direction by being pressed by the wiring board 70 in the step S5 of crimping the wiring board 70 to the relay board 60. There is sex. Against the background of the above circumstances, in the first embodiment, the first adhesive layer 81 is formed so as to partially overlap the mounting region A. That is, the relay board 60 is supported by the first adhesive layer 81 from the Z1 direction. Therefore, the deformation of the relay board 60 in the step S5 of crimping the wiring board 70 to the relay board 60 is suppressed. As a result of suppressing the deformation, it is possible to reduce the possibility that damage such as a crack occurs on the relay board 60.

As understood from the above description, according to the first embodiment, the relay board 60 is deformed in the step S5 in which the wiring board 70 is installed while suppressing poor adhesion between the flow path structure 30 and the relay board 60. There is an advantage that can be reduced.

In the first embodiment, since the wiring board 70 is crimped to the relay board 60 via the second adhesive layer 82, the above-mentioned effect that the deformation of the relay board 60 is suppressed by the first adhesive layer 81 is particularly effective. is there. Further, in the first embodiment, the first wiring W1 formed on the first surface F1 and the second wiring W2 formed on the second surface F2 are electrically connected via the through hole H. In the above configuration, the relay board 60 tends to be easily damaged due to the concentration of stress in the vicinity of the through hole H. Therefore, the configuration of the first embodiment in which the deformation of the relay board 60 is suppressed by the first adhesive layer 81 is particularly effective.

Further, in the first embodiment, the portion of the wiring 72 of the wiring board 70 that overlaps the mounting region A includes the first portion 72a that overlaps the first adhesive layer 81 in a plan view. In step S5 of joining the wiring board 70 to the relay board 60, the second surface F2 of the relay board 60 is pressed by the surface of the wiring 72. Therefore, according to the configuration in which the wiring 72 overlaps the first adhesive layer 81 in a plan view in the mounting region A, there is an advantage that the deformation of the relay board 60 in the step S5 of crimping the wiring board 70 can be effectively suppressed. In the first embodiment, in particular, since the first adhesive layer 81 includes a series of adhesive portions 811 that overlap the plurality of wirings 72 in a plan view, the above-mentioned effect that the deformation of the relay substrate 60 in the step S5 can be suppressed is particularly remarkable. Is.

B: Second Embodiment The second embodiment will be described. For the elements having the same functions as those of the first embodiment in each of the embodiments illustrated below, the reference numerals used in the description of the first embodiment will be used and detailed description of each will be omitted.

FIG. 10 is a plan view of the liquid injection head 26 in which the vicinity of the wiring board 70 in the second embodiment is enlarged. As illustrated in FIG. 10, in the second embodiment as well as in the first embodiment, the mounting region A is a first region A1 that overlaps the first adhesive layer 81 and a second region that does not overlap the first adhesive layer 81. Includes A2.

The first adhesive layer 81 is composed of a plurality of adhesive portions 811. Each bonded portion 811 in the second embodiment extends along a direction intersecting the X-axis and the Y-axis. That is, each adhesive portion 811 extends along a direction in which each wiring 72 of the wiring board 70 is inclined with respect to the extending direction. The angle of each adhesive portion 811 is arbitrary, but FIG. 10 illustrates a configuration in which each adhesive portion 811 extends along a direction of inclination at an angle of 45 ° with respect to the X-axis and the Y-axis. .. As understood from the above description, in the second embodiment as well as in the first embodiment, the first adhesive layer 81 includes a plurality of adhesive portions 811 along the direction intersecting the X axis, and each adhesive is bonded. The unit 811 is continuous over a plurality of wirings 72. In the second embodiment, the same effect as in the first embodiment is realized.

C: Third Embodiment FIG. 11 is a plan view of the liquid injection head 26 in which the vicinity of the wiring board 70 in the third embodiment is enlarged. As illustrated in FIG. 11, in the second embodiment as well as in the first embodiment, the mounting region A is a first region A1 that overlaps the first adhesive layer 81 and a second region that does not overlap the first adhesive layer 81. Includes A2.

The first adhesive layer 81 is composed of a plurality of adhesive portions 811. The plurality of adhesive portions 811 in the third embodiment are arranged in a matrix along the X-axis and the Y-axis. The Y-axis is an example of the "first axis" and the X-axis is an example of the "second axis". Specifically, a plurality of adhesive patterns G are formed between the mounting surface Fa of the flow path structure 30 and the first surface F1 of the relay board 60. Each of the plurality of adhesive patterns G is composed of a plurality of adhesive portions 811 arranged at intervals along the X axis. The plurality of adhesive patterns G are arranged side by side at intervals in the Y-axis direction. The positions of the respective adhesive portions 811 on the X-axis are different between the two adhesive patterns G adjacent to each other in the Y-axis direction. It may be expressed that a plurality of adhesive portions 811 are arranged in a staggered pattern. The same effect as that of the first embodiment is realized in the third embodiment.

D: Modification example Each form illustrated above can be variously transformed. Specific modifications that can be applied to each of the above-described forms are illustrated below. Two or more embodiments arbitrarily selected from the following examples can be appropriately merged to the extent that they do not contradict each other.

(1) The planar shape of the first adhesive layer 81 is not limited to the above-mentioned examples of each form. For example, as illustrated in FIG. 12, the first adhesive layer 81 may include a plurality of adhesive portions 811 extending along the Y axis. The plurality of adhesive portions 811 shown in FIG. 12 are arranged side by side at intervals in the direction of the X axis, and overlap each wiring 72 in a plan view. Further, as illustrated in FIG. 13, the first adhesive layer 81 may be formed in a grid pattern in which a plurality of portions along the X-axis and a plurality of portions along the Y-axis are combined. As can be understood from the example of FIG. 13, it is not essential that the first adhesive layer 81 includes a plurality of adhesive portions 811 that are separated from each other. As can be understood from the above examples, regardless of the planar shape of the first adhesive layer 81, the mounting region A is planar on the first region A1 and the first adhesive layer 81 which overlap the first adhesive layer 81 in a plan view. A configuration including a second region A2 that does not overlap visually is preferable.

(2) The driving element for injecting the ink in the pressure chamber C from the nozzle N is not limited to the piezoelectric element 40 exemplified in each of the above-described embodiments. For example, a heat generating element that generates air bubbles inside the pressure chamber C by heating to fluctuate the pressure may be used as the driving element.

(3) In each of the above-described embodiments, the serial type liquid injection device 100 that reciprocates the transport body 242 on which the liquid injection head 26 is mounted is illustrated, but the line type liquid in which a plurality of nozzles N are distributed over the entire width of the medium 12 is illustrated. The present invention can also be applied to an injection device.

(4) The liquid injection device 100 illustrated in each of the above-described embodiments can be adopted in various devices such as a facsimile machine and a copier, in addition to a device dedicated to printing. However, the application of the liquid injection device of the present invention is not limited to printing. For example, a liquid injection device that injects a solution of a coloring material is used as a manufacturing device that forms a color filter for a display device such as a liquid crystal display panel. Further, a liquid injection device for injecting a solution of a conductive material is used as a manufacturing device for forming wiring and electrodes on a wiring board. Further, a liquid injection device for injecting a solution of an organic substance related to a living body is used, for example, as a manufacturing device for manufacturing a biochip.

(5) The liquid injection head 26 illustrated in each of the above-described embodiments is an example of an electronic device. Examples of the piezoelectric device other than the liquid injection head 26 include, for example.
[A] Ultrasonic devices such as ultrasonic cleaners, ultrasonic diagnostic devices, ultrasonic oscillators or ultrasonic motors,
[B] Various filters such as a blocking filter for harmful rays such as infrared rays, an optical filter using the photonic crystal effect by forming quantum dots, or an optical filter using light interference of a thin film.
[C] Various sensors such as infrared sensor, ultrasonic sensor, heat sensitive sensor, pressure sensor, pyroelectric sensor, or angular velocity sensor,
[D] In addition, various devices such as temperature-electric converters, pressure-electric converters, ferroelectric transistors or piezoelectric transformers,
Is exemplified. The present invention is applied to any electronic device including a structure in which a first substrate and a second substrate are joined.

100 ... liquid injection device, 12 ... medium, 14 ... liquid container, 20 ... control unit, 22 ... transfer mechanism, 24 ... movement mechanism, 242 ... transfer body, 244 ... transfer belt, 26 ... liquid injection head, 28 ... drive circuit , 30 ... Flow path structure, 31 ... First flow path substrate, 311 ... First space, 312 ... Supply flow path, 313 ... Communication flow path, 314 ... Relay flow path, 32 ... Second flow path substrate, 33 ... Vibrating plate, 34 ... Nozzle plate, 35 ... Vibration absorber, 40 ... Piezoelectric element, 41 ... First electrode, 42 ... Piezoelectric layer, 43 ... Second electrode, 50 ... Housing, 51 ... Supply port, 52 ... 2 spaces, 60 ... relay board, 61 ... first layer, 62 ... second layer, 63 ... groove, 65, 66 ... connection terminal, 67 ... adhesive layer, 70 ... wiring board, 71 ... base, 72 ... wiring, R ... Liquid storage chamber, C ... Pressure chamber, N ... Nozzle.

Claims (11)

A first substrate including a first surface and a second surface opposite to the first surface,
A second substrate including a pressure chamber communicating with a nozzle for injecting a liquid and a mounting surface facing the first surface with a gap.
A first adhesive layer interposed between the first surface and the mounting surface,
A flexible wiring board, which is joined to a mounting region which is a part of the second surface, is provided.
The mounting region is a liquid injection head including a first region that overlaps the first adhesive layer in a plan view and a second region that does not overlap the first adhesive layer in a plan view. The wiring board
A flexible substrate including a joint surface to be joined to the second surface,
Includes one or more wires provided on the joint surface.
In the one or more wirings, the portion that overlaps the mounting area in a plan view is
A first portion that overlaps the first adhesive layer in a plan view,
The liquid injection head according to claim 1, comprising a second portion that does not overlap the first adhesive layer in a plan view. The one or more wirings are a plurality of wirings.
The liquid injection head according to claim 2, wherein the first adhesive layer includes a series of adhesive portions that overlap the plurality of wirings in a plan view. The one or more wires extend along the first axis and
The liquid injection head according to claim 2, wherein the first adhesive layer includes a plurality of adhesive portions along a direction intersecting the first axis. The one or more wires extend along the first axis and
The liquid injection head according to claim 2, wherein the first adhesive layer includes a plurality of adhesive portions arranged along the first axis and the second axis intersecting the first axis. The liquid injection head according to any one of claims 2 to 5, further comprising a second adhesive layer interposed between the joint surface and the second surface. The first wiring provided on the first surface and
It is provided with a second wiring provided on the second surface.
The liquid injection head according to any one of claims 1 to 6, wherein the first wiring and the second wiring are electrically connected to each other through a through hole penetrating the first substrate. The liquid injection head according to claim 7, wherein at least a part of one or both of the first wiring and the second wiring is provided inside a groove formed in the first substrate. The liquid injection head according to any one of claims 1 to 8, wherein the first adhesive layer is formed of a photosensitive adhesive. A liquid injection head that injects liquid from a nozzle,
A control unit for controlling the liquid injection head is provided.
The liquid injection head
A first substrate including a first surface and a second surface opposite to the first surface,
A second substrate including a pressure chamber communicating with the nozzle and a mounting surface facing the first surface with a gap.
A first adhesive layer interposed between the first surface and the mounting surface,
A flexible wiring board, which is joined to a mounting region which is a part of the second surface, is provided.
The mounting region is a liquid injection device including a first region that overlaps the first adhesive layer in a plan view and a second region that does not overlap the first adhesive layer in a plan view. A first substrate including a first surface and a second surface opposite to the first surface,
A second substrate including a mounting surface facing the first surface with a gap,
A first adhesive layer interposed between the first surface and the mounting surface,
A flexible wiring board, which is joined to a mounting region which is a part of the second surface, is provided.
The mounting region is an electronic device including a first region that overlaps the first adhesive layer in a plan view and a second region that does not overlap the first adhesive layer in a plan view.

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