Liquid discharge head and method of manufacturing the same

Abstract

To solve the problem that wiring on a wiring board may be broken because a temperature change causes stress on the wiring board when the wiring board is joined to a member in a tension applied state if the linear expansion coefficient of the wiring board is different from that of the member; and to provide a liquid discharge head having high reliability for the temperature change and a method of manufacturing the same.SOLUTION: A liquid discharge head comprises: a discharge module having an element substrate on which elements for discharging liquid are formed, a support member that supports the element substrate, and a wiring board electrically connected to the element substrate; and a flow path member that is connected to the discharge module, and in which flow paths for supplying the liquid discharged by the element substrate. The wiring board is adhered to the support member with a first adhesive, and adhered to the flow path member with a second adhesive having a Young's modulus after curing lower than that of the first adhesive.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head and a manufacturing method thereof. [Background technology]

[0002] A liquid ejection head that ejects liquid to perform recording or the like includes an element substrate manufactured using a silicon substrate. A wiring substrate is generally electrically connected to the element substrate. Such a wiring substrate is bonded across a plurality of members including the element substrate. The members and the wiring substrate are often made of different materials, and may have different linear expansion coefficients. When the linear expansion coefficients of the wiring substrate and the member are different, if an attempt is made to bond the wiring substrate to the member under tension, there is a risk that the wiring substrate will be stressed by temperature change and the wiring of the wiring substrate will break.

[0003] Patent Document 1 describes the use of different adhesives at both ends of the wiring board when bonding the wiring board between the element substrate and the support member. The shortest distance between the first adhesive bonding one end and the second adhesive bonding the other end is made shorter than the distance along the wiring board between the first adhesive and the second adhesive, making it difficult for tension to be applied to the wiring board and improving reliability against temperature changes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-97159 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, there is a method of making the wiring board slack so that tension is less likely to be applied, but controlling the amount of adhesive, thickness, width, etc., when creating slack in the wiring board is difficult, and if the amount of adhesive, etc., cannot be properly controlled, there is a risk that the wiring will break.

[0006] Therefore, the present invention provides a liquid ejection head having high reliability against temperature changes, and a method for manufacturing the same. [Means for solving the problem]

[0007] Therefore, the liquid ejection head of the present invention is a liquid ejection head comprising: an ejection module having an element substrate on which elements for ejecting liquid are formed, a support member for supporting the element substrate, and a wiring substrate electrically connected to the element substrate; and a flow path member connected to the ejection module and having a flow path formed therein for supplying liquid to be ejected by the element substrate, wherein the wiring substrate is bonded to the support member by a first adhesive, and is bonded to the flow path member by a second adhesive having a lower Young's modulus after hardening than that of the first adhesive. Effect of the Invention

[0008] According to the present invention, it is possible to provide a liquid ejection head having high reliability against temperature changes and a method for manufacturing the same. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view showing a main part of the liquid ejection device. [Diagram 2] FIG. 2 is a perspective view showing a liquid ejection head. [Diagram 3] FIG. 2 is an exploded perspective view of each component or unit that constitutes the liquid ejection head. [Figure 4] FIG. 2 is a perspective view showing a discharge module. [Diagram 5] FIG. 13 illustrates the discharge module before application of a sealant. [Figure 6] FIG. 13 is a diagram showing the discharge module after the sealant has been applied. [Figure 7] FIG. 2 is a perspective view showing a liquid ejection head. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is an enlarged view showing part B in FIG. [Figure 10] 4 is a flowchart showing a manufacturing process of the liquid ejection unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] 1 is a perspective view showing a main part of a liquid ejection device 1000 in this embodiment. The liquid ejection device 1000 in this embodiment is a liquid ejection device (hereinafter, also simply referred to as device) that records a color image on a recording medium 3 by ejecting cyan (C), magenta (M), yellow (Y), and black (Bk) inks. In the figure, the X direction is the transport direction of the recording medium 3, the Y direction is the width direction of the recording medium, and the Z direction is the direction intersecting the X and Y directions and is the direction in which liquid is ejected.

[0012] 1 shows an apparatus 1000 in which a liquid ejection head 1 applies ink directly to a recording medium 3 transported in the X direction. The recording medium 3 is mounted on a transport section 2 and transported to a position facing four liquid ejection heads 1 (1C, 1M, 1Y, 1Bk) that eject different inks. The four liquid ejection heads 1 are arranged in the X direction in the order of 1Bk, 1Y, 1M, 1C, and inks are applied to the recording medium 3 in the order of black, yellow, magenta, and cyan. Each liquid ejection head 1 has multiple ejection openings arranged in the Y direction for ejecting ink.

[0013] Although cut paper is shown as the recording medium 3, the recording medium 3 may be continuous paper supplied from a roll of paper. The recording medium 3 is not limited to paper, and may be, for example, a film.

[0014] Furthermore, in this embodiment, an example of a liquid ejection device in which one liquid ejection head 1 ejects ink of a single color has been shown, but one liquid ejection head may be configured to eject ink of multiple colors.

[0015] 2(a) and 2(b) are perspective views showing a liquid ejection head 1 according to the present embodiment. The liquid ejection head 1 is a line-type liquid ejection head in which 17 element substrates 10 capable of ejecting ink are arranged in a straight line (arranged in-line). The liquid ejection head 1 includes a signal input terminal 91 and a power supply terminal 92 electrically connected to each element substrate 10 via a flexible wiring substrate 40 and a printed wiring substrate 90. The signal input terminal 91 and the power supply terminal 92 are electrically connected to a control unit of the device 1000, and supply an ejection drive signal and power required for ejection to the element substrate 10 via the flexible wiring substrate 40, respectively. By consolidating the wiring using an electric circuit in the printed wiring substrate 90, the number of signal output terminals 91 and power supply terminals 92 can be reduced compared to the number of element substrates 10. This can reduce the number of electrical connections that need to be removed when assembling the liquid ejection head 1 to the device 1000 or when replacing the liquid ejection head 1.

[0016] 2(a), a liquid connection part 111 provided on one side of the liquid ejection head 1 is connected to a liquid supply system of the device 1000. This allows ink to be supplied from the supply system of the device 1000 to the liquid ejection head 1, and ink that has passed through the liquid ejection head 1 is collected into the supply system of the device 1000. In this way, the ink is configured to be circulated via the path of the device 1000 and the path of the liquid ejection head 1.

[0017] 3 is an exploded perspective view of each part or unit that constitutes the liquid ejection head 1. A liquid ejection unit 300, a liquid supply unit 220, and a printed wiring board 90 are attached to a housing 80. A liquid connection part 111 is provided in the liquid supply unit 220, and a filter that communicates with each opening of the liquid connection part 111 is provided inside the liquid supply unit 220 to remove foreign matter from the ink being supplied. The liquid that has passed through the filter is supplied to a negative pressure control unit 230 that is arranged on the liquid supply unit 220.

[0018] The negative pressure control unit 230 is a unit equipped with a pressure adjustment valve, and attenuates pressure loss changes in the supply system of the device 1000 (the supply system upstream of the liquid ejection head 1) that occur with fluctuations in the liquid flow rate by the action of valves and spring members provided inside. This makes it possible to stabilize negative pressure changes downstream of the negative pressure control unit 230 (the liquid ejection unit 300 side) within a certain range. Two pressure adjustment valves are built into the negative pressure control unit 230. The two pressure adjustment valves are set to different control pressures, and the high-pressure side communicates with the common supply flow path in the liquid ejection unit 300 via the liquid supply unit 220, and the low-pressure side communicates with the common recovery flow path via the liquid supply unit 220.

[0019] The housing 80 includes a liquid ejection unit support section 81 and an electric wiring board support section 82, and supports the liquid ejection unit 300 and the printed wiring board 90 while ensuring the rigidity of the liquid ejection head 1. The printed wiring board support section 82 supports the printed wiring board 90, and is fixed to the liquid ejection unit support section 81 by screwing. The liquid ejection unit support section 81 is provided with openings 83 and 84 into which a joint rubber 100 is inserted. The liquid supplied from the liquid supply unit 220 is guided via the joint rubber 100 to the second flow path member 60 constituting the liquid ejection unit 300.

[0020] Next, the configuration of the flow path member 210 included in the liquid discharge unit 300 will be described. As shown in FIG. 3, the flow path member 210 is configured by laminating a first flow path member 50 and a second flow path member 60. A flow path through which liquid flows is formed in the first flow path member 50 and the second flow path member 60, and a plurality of discharge modules 200 are bonded to the bonding surface of the first flow path member 50 with an adhesive (not shown). The flow path member 210 is a flow path member that distributes liquid supplied from the liquid supply unit 220 to each discharge module 200 and returns liquid flowing out of the discharge module 200 to the liquid supply unit 220. In addition, the flow path member 210 is fixed to the liquid discharge unit support part 81 with screws, thereby suppressing warping and deformation.

[0021] 4(a) and (b) are perspective views showing the discharge module 200. Also, Fig. 4(c) shows an enlarged view of the vicinity of the discharge port 13 in the element substrate 10.

[0022] In the discharge module 200, the element substrate 10 and the flexible wiring substrate 40 are bonded to a surface 301 (first surface 301) of the support member 30 on which the support member communication port 31 is provided, using an adhesive. Details of the bonding of the element substrate 10 and the flexible wiring substrate 40 to the support member 30 will be described later. The surface of the element substrate 10 opposite to the discharge port surface 131 on which the discharge ports 13 are provided is supported by the first surface 301 of the support member 30. The terminal 16 on the element substrate 10 and the terminal 41 on the flexible wiring substrate 40 are electrically connected by a wire (electrical connection member). Furthermore, the wire is sealed by being covered with a sealant A501. The terminal 42 on the opposite side of the flexible wiring substrate 40 from the element substrate 10 is electrically connected to a connection terminal 93 (see FIG. 3) of the printed wiring substrate 90.

[0023] The support member 30 is a support body for supporting the element substrate 10 and a flow path member for fluidly connecting the element substrate 10 and the flow path member 210 (see FIG. 3), and therefore preferably has a high degree of flatness and can be bonded with sufficiently high reliability. Alumina or a resin material is preferable as the material. In addition to wires, inner leads or the like can be used as electrical connection members for connecting the element substrate 10 and the flexible wiring board 40, and the flexible wiring board 40 and the printed wiring board 90.

[0024] As shown in FIG. 4(c), the element substrate 10 has a plurality of ejection port rows in which a plurality of ejection ports 13 are arranged. At positions corresponding to the ejection ports 13, energy generating elements 15, which are heat generating elements (pressure generating elements) that use thermal energy to foam the liquid, are arranged. A partition 22 defines a pressure chamber 23 in which the energy generating element 15 is provided. The energy generating element 15 is electrically connected to a terminal 16 by an electric wiring (not shown) provided on the element substrate 10. The energy generating element 15 generates heat based on a pulse signal input from a control circuit of the device 1000 via a printed wiring board 90 (see FIG. 3) and a flexible wiring board 40, to boil the liquid. The liquid is ejected from the ejection port 13 by the force of foaming caused by this boiling.

[0025] FIG. 5 is a diagram showing the discharge module 200 in this embodiment before application of a sealant. FIG. 6 is a diagram showing the discharge module 200 in this embodiment after application of a sealant. FIG. 7 is a perspective view showing the liquid discharge head 1, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. FIG. 9 is an enlarged view showing a portion IX in FIG. 8. The element substrate 10 is bonded onto the support member 30 with an adhesive A701. Furthermore, the flexible wiring board 40 is bonded onto the support member 30 with an adhesive C703. The flexible wiring board 40 may be any flexible wiring, and may be an FPC, a TAB, or the like.

[0026] Examples of the adhesive A701 and the adhesive C703 include epoxy resin, acrylic resin, epoxy acrylate resin, imide resin, amide resin, etc. Also, examples of the curing method include two-liquid mixing curing in which a curing agent is mixed, heat curing by heating, UV curing by ultraviolet irradiation, etc.

[0027] The element substrate 10 and one end of the flexible wiring substrate 40 are electrically connected. Methods for electrically connecting the element substrate 10 and the flexible wiring substrate 40 include wire bonding, which connects them with metal wires, and gang bonding, which connects them with inner leads of the flexible wiring substrate 40. A sealant A501 is applied to the lower and upper parts of the electrically connected wires 401 (see FIG. 5), which seals and protects the wires 401 by insulating them. In this manner, the ejection module 200 is completed.

[0028] As shown in FIG. 7 and FIG. 8, one or more discharge modules 200 are arranged on the first flow path member 50 and bonded with an adhesive B702. The flexible wiring board 40 of the discharge module 200 bonded to the first flow path member 50 is bonded and fixed to the first flow path member 50 with an adhesive D704. Furthermore, the other end of the flexible wiring board 40 of the discharge module 200 is adhered and fixed to the printed wiring board 90 and electrically connected. Methods for electrically connecting the flexible wiring board 40 and the printed wiring board 90 include wire bonding, which connects with a metal wire, and gang bonding, which connects with an inner lead of the flexible wiring board 40. This electrical connection is covered with a sealant C503 for insulation protection. A frame member 130 is bonded with an adhesive E705 so as to surround the element substrate 10 of the discharge modules 200 arranged and bonded to the first flow path member 50.

[0029] A sealant B502 is applied between the element substrate 10 and the frame member 130 to complete the liquid ejection head 1. The sealant B502 hardens over time. As shown in FIG. 8, the flexible wiring board 40 is sandwiched between the first flow path member 50 and the frame member 130.

[0030] In this embodiment, the material of the support member 30 is alumina, and the thickness is 1 mm. The flexible wiring board 40 is an FPC in which wiring is contained in a film, and has a linear expansion coefficient of 16.5 ppm and a thickness of 0.2 mm. The first flow path member 50 is made of a resin material with a linear expansion coefficient of 30.1 ppm. The element substrate 10 is bonded to the support member 30 with an adhesive A701, and the flexible wiring board 40 is bonded to the support member 30 with an adhesive C703. The method of electrically connecting the element substrate 10 and the flexible wiring board 40 is a wire bonding method using a gold wire with an outer diameter of 30 μm. The sealant A501 is a thermosetting epoxy resin.

[0031] The surface of the first flow path member 50 to which the discharge module 200 is bonded has a concave shape, and the step of the concave portion is 0.6 mm. The support member 30 of the discharge module 200 is placed in the concave portion of the first flow path member 50, and is bonded by adhesive B702. In this embodiment, 17 discharge modules 200 are arranged on the first flow path member 50, and the adhesive B702 is cured through a heat treatment process.

[0032] The position of the element substrate 10 in the liquid ejection head 1 affects the landing accuracy of the ejected liquid, that is, it greatly affects the recording quality of the ejected liquid. Therefore, the adhesive A701 used to fix the element substrate 10 to the support member 30 and the adhesive B702 used to fix the support member 30 to the first flow path member 50 need to be materials that have sufficient hardness after curing. It is desirable to use adhesives A701 and B702 with a Young's modulus of, for example, about 0.4 GPa or more and 10 GPa or less. In this embodiment, a thermosetting epoxy resin with a Young's modulus of about 1.1 GPa after curing is used for the adhesive A701 and adhesive B702.

[0033] Since the flexible wiring board 40 is electrically connected by a wire having an outer diameter of 30 μm, it is necessary to use an adhesive C703 having sufficient holding power to prevent the wire from breaking due to the movement of the flexible wiring board 40. In addition, it is preferable to use an adhesive C703 having a Young's modulus of, for example, about 0.4 GPa or more and 10 GPa or less. In this embodiment, a thermosetting epoxy resin having a Young's modulus after curing of about 0.96 GPa is used as the adhesive C703.

[0034] 8 and 9, an intermediate portion of the flexible wiring board 40 of the ejection module 200 is adhesively joined to the outer periphery of the first flow path member 50 using an adhesive D704. At this time, the flexible wiring board 40 is adhesively fixed so as to bridge between the support member 30 and the first flow path member 50.

[0035] The liquid ejection head 1 may be exposed to high or low temperature environments due to heat generation from the element substrate 10, or due to the usage environment or logistics environment. During such temperature changes, various members undergo thermal contraction, and the thermal contraction of the first flow path member 50, which is made of a resin member, is particularly large. When the first flow path member 50 thermally contracts due to temperature changes, a large tensile stress or contraction stress is applied to the flexible wiring board 40 fixed to the support member 30 and the first flow path member 50 in a bridging manner, and there is a risk that part of the wiring of the flexible wiring board 40 will break.

[0036] Therefore, in this embodiment, in order to relieve the stress on the flexible wiring board 40, an adhesive D704 that fixes the flexible wiring board 40 to the first flow path member 50 is used that has a lower Young's modulus than the adhesive C703 that bonds the flexible wiring board 40 and the support member 30. In other words, an adhesive with a lower rigidity than the adhesive C703 is used for the adhesive D704 that fixes the flexible wiring board 40 to the first flow path member 50. It is desirable to use an adhesive C704 with a Young's modulus of, for example, about 0.005 GPa or more and 0.5 GPa or less. In this embodiment, a room temperature curing acrylic modified silicone with a Young's modulus of about 0.15 GPa is used for the adhesive D704.

[0037] The adhesive E705 used to bond the frame member 130 to the first flow path member 50 is also interposed between the frame member 130 and the flexible wiring board 40, and fixes the flexible wiring board 40. Therefore, in order to reduce the stress on the flexible wiring board 40, it is desirable to use an adhesive E705 having a lower Young's modulus than the adhesive C703. In this embodiment, the same room temperature curing acrylic modified silicone as the adhesive D704 is used as the adhesive E705. The Young's modulus of the adhesive E705 may be equal to or less than the Young's modulus of the adhesive D704.

[0038] According to the configuration of this embodiment, an adhesive having a lower Young's modulus than the adhesive C703 is used for the adhesive D704 that bonds the first flow path member 50 and the flexible wiring board 40, and for the adhesive E705 that fixes the frame member 130 and the flexible wiring board 40. This allows the adhesives D704 and E705 to deform and alleviate stress that occurs in the flexible wiring board 40 due to thermal contraction of the flexible wiring board 40 and expansion of the first flow path member 50 caused by heat generation from the element substrate 10, changes in the environmental temperature, and the like. This reduces the risk of damage to the flexible wiring board 40.

[0039] The stress applied to flexible wiring board 40 was compared between the case in which the Young's modulus of adhesives D704 and E705 is low relative to the Young's modulus of adhesive C703 as in this embodiment, and the case in which the Young's modulus of adhesives D704 and E705 is the same relative to the Young's modulus of adhesive C703.

[0040] When adhesive D704 was made of the same material (Young's modulus 0.96 GPa) as adhesive C703, the stress applied to flexible wiring board 40 when the temperature changed from -30°C to +100°C was calculated to be 236 to 474 MPa.

[0041] On the other hand, in this embodiment, in which the Young's modulus of adhesive D704 and adhesive E705 is 0.15 GPa, which is lower than that of adhesive C703, the stress applied to flexible wiring board 40 during the same temperature change as above was 171 to 258 MPa. In other words, it was confirmed that the stress was reduced more than when the Young's modulus of adhesive D704 bonding the first flow path member 50 and flexible wiring board 40 and the Young's modulus of adhesive C703 bonding the flexible wiring board 40 and support member 30 were the same.

[0042] In this embodiment, a configuration in which 17 discharge modules 200 are arranged on the first flow path member 50 has been described, but the same effect can be obtained with a configuration in which one discharge module 200 is joined.

[0043] 10 is a flowchart showing the manufacturing process of the liquid ejection unit 300. In addition, the symbol "S" in the explanation of each process means a step in the flowchart. In manufacturing the liquid ejection unit 300, first, in S01, the element substrate 10 is bonded to the support member 30 using an adhesive A701. In S02, the adhesive A701 is cured by heat treatment. Then, in S03, the flexible wiring substrate 40 is bonded to the support member 30 using an adhesive C703. In S04, the flexible wiring substrate 40 is wire-bonded to the element substrate 10. Then, in S05, the sealant A501 is applied to cover the wire-bonded portion.

[0044] In S06, the adhesive C703 and the sealant A501 are cured by heat treatment to complete the discharge module 200. In S07, the support member 30 is adhered to the recess of the first flow path member 50 using the adhesive B702, thereby joining the discharge module 200 to the first flow path member 50. Then, in S08, the printed wiring board 90 and the flexible wiring board 40 are joined. In S09, the printed wiring board 90 is electrically connected to the terminals 42 of the flexible wiring board 40 by wire bonding. In S10, the sealant A is applied to the wire bonding portion of the flexible wiring board 40 to cover it.

[0045] Then, in S11, the sealant A is hardened by heat treatment. After that, in S12, the flexible wiring board 40 is bonded to the first flow path member 50 using an adhesive D704. Then, in S13, the frame member 130 is bonded to the first flow path member 50 using an adhesive E705. At this time, the frame member 130 and the flexible wiring board 40 are also bonded by the adhesive E705. Thereafter, the sealant B (not shown in FIGS. 8 and 9) is applied between the frame member 130 and the element substrate 10, and the liquid discharge unit 300 is completed.

[0046] In this embodiment, an example has been described in which the flexible wiring board 40 is directly bonded to the first flow path member 50 using the adhesive D704, but this is not limited to this, and the flexible wiring board 40 may be bonded to the first flow path member 50 via another member.

[0047] In this way, the adhesive D704 that fixes the flexible wiring board 40 to the first flow path member 50 has a lower Young's modulus than the adhesive C703 that bonds the flexible wiring board 40 and the support member 30. This makes it possible to provide a liquid ejection head that is highly reliable against temperature changes.

[0048] The disclosure of this embodiment includes the following configurations and methods.

[0049] (Configuration 1) an element substrate on which elements for ejecting liquid are formed; A support member for supporting the element substrate; a wiring board electrically connected to the element substrate; a dispensing module having a flow path member connected to the discharge module and having a flow path formed therein for supplying a liquid to be discharged by the element substrate; A liquid ejection head comprising: A liquid ejection head characterized in that the wiring board is adhered to the support member by a first adhesive, and is adhered to the flow path member by a second adhesive having a lower Young's modulus after hardening than the first adhesive.

[0050] (Configuration 2) the wiring board is a flexible wiring board, The liquid ejection head according to configuration 1, wherein an electrical connection portion between the element substrate and the flexible wiring substrate is sealed with a first sealant.

[0051] (Configuration 3) The device further includes a frame member provided to surround the element substrate, The liquid ejection head according to configuration 2, wherein the flexible wiring board is bonded to the frame member by a third adhesive having a lower Young's modulus after hardening than the first adhesive.

[0052] (Configuration 4) 4. The liquid ejection head according to configuration 3, wherein the second adhesive and the third adhesive are the same adhesive.

[0053] (Configuration 5) 4. The liquid ejection head according to configuration 3, wherein the Young's modulus of the second adhesive after curing is equal to or less than the Young's modulus of the third adhesive after curing.

[0054] (Configuration 6) A liquid ejection head according to any one of configurations 1 to 5, wherein the Young's modulus of the first adhesive after curing is 0.4 GPa or more and 10 GPa or less, and the Young's modulus of the second adhesive after curing is 0.005 GPa or more and 0.5 GPa or less.

[0055] (Configuration 7) The liquid ejection head according to configuration 3 or 4, wherein a gap between the element substrate and the frame member is sealed with a second sealant.

[0056] (Configuration 8) The flexible wiring board is sandwiched between the flow path member and the frame member, one surface of the sandwiched position is adhered to the flow path member by the second adhesive, and the other surface is adhered to the frame member by the third adhesive, forming a liquid ejection head as described in configuration 3 or 4.

[0057] (Configuration 9) The liquid ejection head according to any one of the connection configurations 1 to 8, wherein the flow path member is connected to a plurality of the ejection modules.

[0058] (Method 1) an element substrate on which elements for ejecting liquid are formed; A support member for supporting the element substrate; a wiring board electrically connected to the element substrate; a dispensing module having a flow path member connected to the discharge module and having a flow path formed therein for supplying a liquid to be discharged by the element substrate; A method for manufacturing a liquid ejection head comprising: adhering the wiring board to the support member with a first adhesive; a step of adhering the wiring board to the flow path member by a second adhesive having a Young's modulus after hardening lower than that of the first adhesive; A method for manufacturing a liquid ejection head, comprising:

[0059] (Method 2) The method for producing a liquid ejection head according to method 1, further comprising a step of curing the first adhesive by heat treatment.

[0060] (Method 3) the wiring board is a flexible wiring board, The method for producing a liquid ejection head according to method 1 or 2, further comprising the step of electrically connecting the flexible wiring board and the element substrate by wire bonding. [Explanation of symbols]

[0061] 30 Support member 40 Flexible wiring board 90 Printed Wiring Board 200 Dispensing Module 300 Liquid Dispensing Unit 703 Adhesive C 704 Adhesive D 705 Adhesive E

Claims

1. A substrate on which an element for dispensing liquid is formed, A support member that supports the element substrate, A wiring board electrically connected to the element substrate, A dispensing module having, A flow channel member supporting the discharge module and having a flow channel formed therein for supplying the liquid discharged by the element substrate, A liquid dispensing head equipped with, The wiring board is bonded to the support member with a first adhesive and to the flow path member with a second adhesive. The support member is bonded to the flow channel member by a third adhesive, the third adhesive having a Young's modulus lower than that of the first adhesive after curing. A liquid dispensing head characterized in that the Young's modulus of the second adhesive after curing is lower than the Young's modulus of the first adhesive and the third adhesive after curing.

2. The aforementioned wiring board is a flexible wiring board, The liquid dispensing head according to claim 1, wherein the electrical connection between the element substrate and the flexible wiring substrate is sealed with a first sealant.

3. The element substrate is further provided with a frame member surrounding it, The liquid dispensing head according to claim 2, wherein the flexible wiring board is bonded to the frame member by a fourth adhesive whose cured Young's modulus is lower than that of the first adhesive after curing.

4. The liquid dispensing head according to claim 3, wherein the second adhesive and the fourth adhesive are the same adhesive.

5. The liquid dispensing head according to claim 3, wherein the Young's modulus of the second adhesive after curing is equal to or less than the Young's modulus of the fourth adhesive after curing.

6. A liquid dispensing head according to any one of claims 1 to 5, wherein the Young's modulus of the first adhesive after curing is 0.4 GPa or more and 10 GPa or less, and the Young's modulus of the second adhesive after curing is 0.005 GPa or more and 0.5 GPa or less.

7. The liquid dispensing head according to claim 6, wherein the Young's modulus of the third adhesive after curing is 0.4 GPa or more and 10 GPa or less.

8. The liquid dispensing head according to claim 3, wherein the space between the element substrate and the frame member is sealed with a second sealant.

9. The liquid discharge head according to claim 3, wherein the flexible wiring board is sandwiched between the flow channel member and the frame member, one side of the sandwiched position is bonded to the flow channel member by the second adhesive, and the other side is bonded to the frame member by the fourth adhesive.

10. The liquid dispensing head according to claim 1, wherein the second adhesive contains an acrylic-modified silicone resin.

11. The element substrate is bonded to the support member by a fifth adhesive, The liquid dispensing head according to claim 1, wherein the Young's modulus of the second adhesive after curing is lower than the Young's modulus of the fifth adhesive after curing.

12. The liquid discharge head according to claim 1, wherein the flow path member is connected to a plurality of discharge modules.

13. An element substrate equipped with an element for dispensing liquid, A support member that supports the element substrate, A wiring board electrically connected to the element substrate, A dispensing module having, A flow channel member supporting the discharge module and having a flow channel formed therein for supplying the liquid discharged by the element substrate, A method for manufacturing a liquid dispensing head equipped with, The process involves bonding the wiring board to the support member with a first adhesive, The steps include bonding the support member to the flow channel member with a third adhesive, The process of bonding the wiring board to the flow channel member with a second adhesive having a Young's modulus lower than that of the first and third adhesives after curing, A method for manufacturing a liquid dispensing head, characterized by having the following features.

14. A method for manufacturing a liquid dispensing head according to claim 13, further comprising the step of curing the first adhesive by heat treatment.

15. The aforementioned wiring board is a flexible wiring board, A method for manufacturing a liquid discharge head according to claim 13, further comprising the step of electrically connecting the flexible wiring board and the element board by wire bonding.

16. The method for manufacturing a liquid dispensing head according to claim 13, further comprising curing a second adhesive which is a room-temperature curing adhesive.

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