Liquid dispensing tip, liquid dispensing head, and method for manufacturing a liquid dispensing head

Abstract

The objective is to provide a liquid dispensing head that can suppress the deterioration of liquid dispensing performance. [Solution] The liquid dispensing tip comprises a first substrate and a second substrate. The bonding surface of the second substrate with the liquid supply member is provided with a first adhesive layer containing a first adhesive and a second adhesive layer containing a second adhesive. When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the second substrate has a protruding portion that protrudes in a first direction from the first substrate. The second adhesive layer is provided on the protruding portion.

Description

Technical Field

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

Background Art

[0002] Generally, in order to bond a plurality of members constituting a liquid ejection substrate that ejects a liquid, two or more types of adhesives may be used.

[0003] Patent Document 1 discloses a liquid ejection head (liquid ejection substrate) in which a first member and a second member including an energy generating element for generating energy for ejecting a liquid are bonded by two or more types of adhesives. In the liquid ejection head of Patent Document 1, a first adhesive is applied to a first convex portion in the first member, and a second adhesive is applied to a second convex portion in the first member. In the liquid ejection head of Patent Document 1, the first convex portion and the second convex portion have different heights from each other. Therefore, even when two or more types of adhesives are used, mixing of these adhesives can be suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the liquid ejection head of Patent Document 1, the physical property values of the first adhesive and the physical property values of the second adhesive are different from each other. Therefore, in the liquid ejection head of Patent Document 1, the resonance frequencies generated during the liquid ejection operation are different between the location where the first adhesive is applied and the location where the second adhesive is applied. That is, in the liquid ejection head of Patent Document 1, there is a risk of affecting the liquid ejection performance.

[0006] Therefore, the present disclosure aims to provide a liquid dispensing head that can suppress a decrease in liquid dispensing performance. [Means for solving the problem]

[0007] The liquid discharge tip of the present disclosure comprises a first substrate on which a nozzle for discharging liquid supplied from a liquid supply member is formed, and a second substrate on which a connecting channel is formed that is connected to a supply channel formed in the liquid supply member, wherein the bonding surface of the second substrate with the liquid supply member is provided with a first adhesive layer containing a first adhesive and a second adhesive layer containing a second adhesive, and when the liquid discharge tip is viewed from a direction perpendicular to the bonding surface, the second substrate has a protruding portion that protrudes in a first direction from the first substrate, and the second adhesive layer is provided on the protruding portion. [Effects of the Invention]

[0008] The liquid dispensing head of this disclosure can suppress a decrease in liquid dispensing performance. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic perspective view of a liquid dispensing device applicable to one embodiment. [Figure 2] A schematic perspective view of a liquid dispensing head that can be applied to one embodiment. [Figure 3] A schematic perspective view of a liquid dispensing head that can be applied to one embodiment. [Figure 4] A schematic exploded perspective view of a liquid dispensing head applicable to one embodiment. [Figure 5] A schematic perspective view of a liquid dispensing unit applicable to one embodiment. [Figure 6] A schematic perspective view of a liquid dispensing unit applicable to one embodiment. [Figure 7] A schematic exploded perspective view of a liquid dispensing unit applicable to one embodiment. [Figure 8] Schematic perspective view of an electrical connection part applicable to one embodiment. [Figure 9] Schematic diagram of a liquid ejection chip applicable to one embodiment. [Figure 10] Schematic cross-sectional view of a liquid ejection chip applicable to one embodiment. [Figure 11] Explanatory drawing of an adhesive applicable to one embodiment. [Figure 12] Diagram showing a liquid ejection chip and a liquid ejection unit in a comparative example. [Figure 13] Diagram showing a liquid ejection chip and a liquid ejection unit in a comparative example. [Figure 14] (a) is a graph showing the simulation result of the vertical stress generated in the liquid ejection part of one embodiment, and (b) is a schematic bottom view of the liquid ejection chip applicable to one embodiment. [Figure 15] Flowchart showing a method for manufacturing a liquid ejection head applicable to one embodiment. [Figure 16] Schematic plan view of a liquid ejection chip in a state where an adhesive applicable to one embodiment is applied. [Figure 17] (a) is a graph showing the simulation result of the vertical stress generated in the liquid ejection part of one embodiment, and (b) is a schematic bottom view of the liquid ejection chip applicable to one embodiment. [Mode for Carrying Out the Invention]

[0010] [First Embodiment] <Liquid ejection device 10> FIG. 1 is a schematic perspective view of a liquid ejection device 10 applicable to the present embodiment.

[0011] The Z, X, and Y axes described in each of the drawings referred to in the following description indicate the coordinate axes in the liquid ejection device 10. The Z axis indicates the first axis, the X-axis direction indicates the second axis, and Y indicates the third axis. These axes are orthogonal to each other. The Z-axis direction (the first-axis direction) indicates the direction in which liquid (for example, ink) is ejected by the liquid ejection head 100. The X-axis direction (the second-axis direction) indicates the arrangement direction of the nozzles 3 (see FIG. 9 and the like) in the liquid ejection chip 210 (see FIG. 6 and the like). The Y-axis direction (the third-axis direction) indicates the conveyance direction of the recording medium P.

[0012] While the conveyance device 11 continuously conveys the recording medium P in the conveyance direction, the liquid ejection device 10 shown in FIG. 1 records an image by ejecting liquid (for example, ink) from the liquid ejection head 100 disposed at a fixed position. As described above, in the present embodiment, an inkjet recording device including a so-called full-line type liquid ejection head 100 is used as the liquid ejection device 10. The liquid ejection head 100 is formed with nozzles 3 (see FIG. 9 and the like) for ejecting liquid (for example, ink) over the side corresponding to the entire width (the length in the X-axis direction) of the recording medium P.

[0013] In the present embodiment, the liquid ejection head 100 corresponds to four colors of cyan (C), magenta (M), yellow (Y), and black (K). Specifically, the liquid ejection head 100 includes a first liquid ejection head 100Ca and a second liquid ejection head 100Cb corresponding to cyan (C) ink. The liquid ejection head 100 includes a third liquid ejection head 100Ma and a fourth liquid ejection head 100Mb corresponding to magenta (M) ink. The liquid ejection head 100 includes a fifth liquid ejection head 100Ya and a sixth liquid ejection head 100Yb corresponding to yellow (Y) ink. The liquid ejection head 100 includes a seventh liquid ejection head 100Ka and an eighth liquid ejection head 100Kb corresponding to black (K) ink.

[0014] The recording medium P is conveyed in the conveyance direction (-Y-axis direction) by the conveyance device 11. Recording is performed on the recording medium P by the liquid ejection head 100. [[ID=I3]]

[0015] Note that the liquid dispensing device 10 shown in Figure 1 is merely an example. The liquid dispensing device 10 may be configured to accommodate a liquid dispensing head 100 of any form. For example, the liquid dispensing head 100 may be configured to dispense only one type of ink, or it may be configured to dispense more than the four types of ink described above.

[0016] <Liquid dispensing head 100> Figure 2 is a schematic perspective view of a liquid dispensing head 100, which can be applied to this embodiment, as seen from below.

[0017] As shown in Figure 2, in the liquid discharge head 100 of this embodiment, four liquid discharge units 200 are arranged in a staggered pattern on a base member 310. A frame member 320 is joined to the base member 310. The frame member 320 has a frame structure that supports the ends of the support members 260 (see Figure 5, etc.). A reference member 340 is joined to the base member 310. The reference member 340 positions the liquid discharge head 100 relative to the liquid discharge device 10 (see Figure 1).

[0018] In this embodiment, the frame member 320 is formed to support multiple support members 260 with a single frame member. However, multiple frame members 320 may be formed, each supporting a separate support member 260.

[0019] Figure 3 is a schematic top-down perspective view of a liquid dispensing head 100 that can be applied to this embodiment.

[0020] As shown in Figure 3, the exterior of the liquid discharge head 100 is provided with a first cover member 420 for covering and protecting the electrical circuit board, and a second cover member 430 for covering and protecting the electrical connection part 252 (see Figure 8). The exterior of the liquid discharge head 100 is also provided with a liquid connection part 501 for supplying liquid to the inside of the liquid discharge head 100, and a refrigerant connection part 611 for supplying refrigerant to the inside of the liquid discharge head 100.

[0021] Figure 4 is a schematic exploded perspective view of a liquid dispensing head 100 that can be applied to this embodiment.

[0022] As shown in Figure 4, the liquid discharge head 100 contains a base unit 300, an electrical wiring board 400, a board holding member 410 for holding the electrical wiring board 400, a liquid supply unit 500, and a cooling unit 600. The base unit 300 includes a base member 310 and a frame member 320. The liquid supply unit 500 supplies liquid to the liquid discharge unit 200 via the base unit 300. The cooling unit 600 cools the drive circuit.

[0023] <Liquid Dispensing Unit 200> Figure 5 is a schematic top-down perspective view of a liquid dispensing unit 200 that can be applied to this embodiment.

[0024] As shown in Figure 5, the liquid discharge unit 200 includes a liquid supply member 240 that supplies liquid to a liquid discharge tip 210 (see Figure 6, etc.) and a flexible wiring board 250. Suitable examples of materials that can be applied to the liquid supply member 240 include alumina and resin.

[0025] Figure 6 is a schematic perspective view from below of a liquid dispensing unit 200 that can be applied to this embodiment.

[0026] As shown in Figure 6, the liquid dispensing unit 200 includes a liquid dispensing tip 210 for dispensing liquid, and a flexible wiring board 250 that is electrically connected to the liquid dispensing tip 210. The flexible wiring board 250 is provided with a drive circuit board 251 for driving the energy generating element 6 (see Figure 10(b)) of the liquid dispensing tip 210.

[0027] Furthermore, the liquid discharge unit 200 includes a support member 260 that is joined to the nozzle surface 201a (see Figure 9(a)) of the liquid discharge tip 210. The thickness of the support member 260 is preferably 300 μm or less. The narrower the gap between the nozzle surface 201a (see Figure 9(a)) and the recording medium P (see Figure 1), the more image distortion can be suppressed.

[0028] Figure 7 is a schematic exploded perspective view of a liquid dispensing unit 200 that can be applied to this embodiment.

[0029] As shown in Figure 7, the support member 260 has an opening 261 that allows liquid to be discharged from the nozzle 3 (see Figure 9(a)).

[0030] <Electrical connection part 252> Figure 8 is a schematic perspective view of an electrical connection section 252 that can be applied to this embodiment.

[0031] As shown in Figure 8, thin plate portions 211 are provided at both ends of the liquid discharge tip 210. Electrode portions 212 are provided on the thin plate portions 211. The flexible wiring board 250 is electrically connected to the liquid discharge tip 210 by bringing the electrical connection portion 252 of the flexible wiring board 250 and the electrodes of the electrode portions 212 into contact with each other. A support member 260 (see Figure 5, etc.) is joined to the nozzle surface 201a (see Figure 9(a)) to prevent liquid from entering the electrical connection portion 252 and to protect the liquid discharge tip 210.

[0032] <Liquid dispensing tip 210> Figure 9(a) is a schematic bottom view of a liquid dispensing tip 210 that can be applied to this embodiment.

[0033] As shown in Figure 9(a), the liquid discharge tip 210 includes a flow path forming substrate 204 and a nozzle substrate 201. The nozzle substrate 201 has a nozzle surface 201a on which nozzles 3 are formed. The bottom surface (nozzle surface 201a) of the liquid discharge tip 210 is formed on the nozzle substrate 201. A row of nozzles is formed on the nozzle surface 201a, consisting of multiple nozzles 3 for discharging liquid arranged along the longitudinal direction (X-axis direction) of the nozzle substrate 201. In this embodiment, multiple rows of nozzles are arranged side by side along the Y-axis direction.

[0034] The nozzle surface 201a is treated with a water-repellent coating to suppress liquid adhesion. However, in the area of ​​the nozzle surface 201a that is in contact with the support member 260, it is desirable to remove this water-repellent coating in order to improve the adhesive strength of the adhesive.

[0035] Figure 9(b) is a schematic plan view of a liquid dispensing tip 210 that can be applied to this embodiment.

[0036] As shown in Figure 9(b), the channel forming substrate 204 has a bonding surface 204a. A connecting channel 15 for supplying and recovering liquid to and from the liquid discharge tip 210 is formed in the channel forming substrate 204. An air communication port 16 is formed in the channel forming substrate 204 to allow air to be supplied to and from the liquid discharge tip 210.

[0037] The connecting channel 15 communicates with the liquid connection section 501 (see Figure 3) via the liquid supply unit 500 (see Figure 4). The liquid connection section 501 is connected to an external liquid tank (not shown). As a result, the liquid supplied from the liquid tank is supplied to the inside of the liquid discharge tip 210 via the liquid connection section 501 and the connecting channel 15.

[0038] <Internal structure of liquid dispensing tip 210> Figure 10(a) is a schematic cross-sectional perspective view of a liquid dispensing tip 210 that can be applied to this embodiment. Note that Figure 10(a) shows a cross-section of the liquid dispensing tip 210 when cut along the line XA-XA in Figure 9(a).

[0039] As shown in Figure 10(a), the liquid discharge tip 210 includes a first substrate 220 and a second substrate 230. The first substrate 220 comprises a nozzle substrate 201, a liquid chamber substrate 202, and a liquid supply substrate 203. The first substrate 220 is constructed by stacking the liquid supply substrate 203, the liquid chamber substrate 202, and the nozzle substrate 201 in this order.

[0040] The second substrate 230 includes a channel-forming substrate 204 containing an elastic damper film 204D. Inside the pressure chamber 5 formed in the first substrate 220, which includes a liquid supply substrate 203 fixed to the channel-forming substrate 204, the pressure fluctuates when liquid is discharged. However, the damper film 204D deforms due to the pressure fluctuations generated inside the pressure chamber 5, thereby suppressing the propagation of these pressure fluctuations to other pressure chambers. The liquid discharge tip 210 is constructed by stacking the second substrate 230 and the first substrate 220 in this order.

[0041] Figure 10(b) is an enlarged perspective view showing a portion of Figure 10(a).

[0042] As shown in Figure 10(b), in the first substrate 220, the liquid chamber substrate 202 includes an elastic diaphragm 9. With the liquid supply substrate 203, liquid chamber substrate 202, and nozzle substrate 201 stacked in this order, a pressure chamber 5 connected to the nozzle 3 is formed between the nozzle substrate 201 and the liquid supply substrate 203. In each of the multiple pressure chambers 5, the diaphragm 9, which constitutes a part of the liquid chamber substrate 202, functions as a deformable wall surface.

[0043] The pressure chamber 5 functions as a flow path connected to the nozzle 3. The height (length in the Z-axis direction) of the flow path consisting of the pressure chamber 5 and the nozzle 3 is preferably 300 μm or less. By thinning the flow path in this way, relatively high discharge and circulation performance can be achieved. Therefore, the combined thickness of the nozzle substrate 201 and the liquid chamber substrate 202, which constitute a part of the flow path, is preferably 300 μm or less.

[0044] The diaphragm 9 is equipped with multiple energy generating elements 6, each corresponding to one of the multiple liquid chambers, for generating energy to discharge the liquid.

[0045] In this embodiment, a piezoelectric element is used as the energy generating element 6. The energy generating element 6 is provided at a position corresponding to each of the multiple nozzles 3. The energy generating element 6 receives power to discharge the liquid and is driven, causing the diaphragm 9 to deform. As the diaphragm 9 deforms, the liquid filled inside the pressure chamber 5 is pressurized. As the liquid filled inside the pressure chamber 5 is pressurized, the liquid is discharged from the nozzle 3.

[0046] On the liquid chamber substrate 202, a liquid supply substrate 203 is bonded to the surface opposite to the surface bonded to the nozzle substrate 201. The liquid supply substrate 203 has individual supply channels 7 for supplying liquid to the pressure chamber 5 and individual recovery channels 8 for recovering liquid from the pressure chamber 5. With the liquid supply substrate 203, liquid chamber substrate 202, and nozzle substrate 201 stacked in this order, the individual supply channels 7 and individual recovery channels 8 are connected to the pressure chamber 5. The materials constituting the nozzle substrate 201, liquid chamber substrate 202, liquid supply substrate 203, and channel forming substrate 204 each include silicon, etc.

[0047] In this embodiment, each of these substrates is formed individually. However, each of these substrates may be formed integrally.

[0048] In the second substrate 230, a connecting channel 15, a common supply channel 27, a common supply connecting passage 17, a common recovery connecting passage 18, and a common recovery channel 28 are formed on the channel-forming substrate 204. The common supply channel 27 is connected to the common supply connecting passage 17. With the second substrate 230 and the first substrate 220 stacked in this order, one common supply connecting passage 17 is connected to a plurality of individual supply channels 7.

[0049] With the second substrate 230 and the first substrate 220 stacked in this order, the multiple individual recovery channels 8 are connected to a single common recovery communication channel 18. The common recovery communication channel 18 is connected to a common recovery channel 28. Liquid flowing from a liquid tank (not shown) into the common supply channel 27 via the connecting channel 15 flows into the individual supply channels 7 via the common supply communication channel 17 and is supplied to the pressure chamber 5.

[0050] When the energy generating element 6 is activated, the liquid supplied to the pressure chamber 5 is discharged from the nozzle 3. The liquid that is not discharged flows into the individual recovery channel 8.

[0051] Furthermore, when the energy generating element 6 is not operating (for example, when circulating to adjust the liquid temperature), all the liquid supplied to the pressure chamber 5 flows into the individual recovery channel 8. The liquid that flows into the individual recovery channel 8 flows into the common recovery channel 28 via the common recovery communication channel 18, and then is recovered into a liquid tank (not shown) via the connecting channel 15.

[0052] <First adhesive 701, and second adhesive 702> Figure 11(a) is a schematic plan view of the liquid dispensing tip 210 with an adhesive applied, which can be applied to this embodiment.

[0053] As shown in Figure 11(a), when the liquid dispensing tip 210 is viewed from above, the first adhesive 701 and the second adhesive 702 are applied to the bonding surface 204a of the liquid dispensing tip 210. The physical properties of the first adhesive 701 and the second adhesive 702 are different from each other. Examples of physical properties include the coefficient of linear expansion and the modulus of elasticity.

[0054] For example, the coefficient of thermal expansion of the first adhesive 701 is 1.2 times greater than the coefficient of thermal expansion of the second adhesive 702. The modulus of elasticity of the first adhesive 701 is 1.2 times greater than the modulus of elasticity of the second adhesive 702. Alternatively, the coefficient of thermal expansion of the second adhesive 702 may be 1.2 times greater than the coefficient of thermal expansion of the first adhesive 701. The modulus of elasticity of the second adhesive 702 may be 1.2 times greater than the modulus of elasticity of the first adhesive 701.

[0055] The first adhesive 701 is applied around a row of connecting channels 15 arranged along the shorter direction (Y-axis direction). This makes it possible to supply liquid from the liquid supply member 240 (see Figure 11(b), etc.) to the liquid discharge tip 210 while suppressing liquid leakage. Since the first adhesive 701 is applied near the connecting channels 15 through which the liquid flows, it is preferable that it has liquid resistance (for example, chemical resistance to ink).

[0056] Meanwhile, the second adhesive 702 is applied to both ends of the liquid dispensing tip 210 in the longitudinal direction (X-axis direction).

[0057] In this embodiment, the second substrate 230 has a first projection 800 that protrudes outward from the longitudinal (X-axis direction) end of the first substrate 220 when the second substrate 230 is laminated on the first substrate 220. The second adhesive 702 is applied only to the first projection 800.

[0058] The curing timing of the first adhesive 701 and the curing timing of the second adhesive 702 are different. The second adhesive 702 cures before the first adhesive 701. For example, the second adhesive 702 cures at room temperature, while the first adhesive 701 cures at a temperature higher than room temperature. With this configuration, when performing the heat curing treatment to fix the liquid dispensing tip 210 to the liquid supply member 240, the second adhesive 702 cures before the first adhesive 701, making it possible to temporarily fix the liquid dispensing tip 210 to the liquid supply member 240.

[0059] Then, by curing the first adhesive 701 with the liquid dispensing tip 210 temporarily fixed to the liquid supply member 240, the liquid dispensing tip 210 can be fixed to the liquid supply member 240 while suppressing displacement of the liquid dispensing tip 210.

[0060] An example of a first adhesive 701 that can be applied to this embodiment is a thermosetting adhesive. However, the example of the first adhesive 701 is not limited to this, as long as it has resistance to the liquid used.

[0061] Examples of second adhesives 702 applicable to this embodiment include thermosetting adhesives, UV-curing adhesives, two-component mixed adhesives, and anaerobic curing adhesives. The second adhesive 702 is not limited to these, as long as it can be cured before the first adhesive 701 cures.

[0062] As in this embodiment, by surrounding the connecting channel 15 with the first adhesive 701 and applying the second adhesive 702 at a position away from the connecting channel 15, the risk of liquid adhering to the second adhesive 702 can be reduced.

[0063] Figure 11(b) is a schematic cross-sectional view of the liquid discharge unit 200 when cut along the X-axis.

[0064] As shown in Figure 11(b), the liquid discharge tip 210 comprises a first substrate 220 and a second substrate 230. The first substrate 220 has a nozzle 3 (see Figure 10(a), etc.) formed on it that discharges liquid supplied from a liquid supply member 240. The second substrate 230 has a connecting channel 15 (see Figure 11(a), etc.) that is connected to a supply channel 241 formed in the liquid supply member 240.

[0065] A first adhesive layer 701a containing a first adhesive 701 and a second adhesive layer 702a containing a second adhesive 702 are provided on the bonding surface of the second substrate 230 with the liquid supply member 240. When the liquid discharge tip 210 is viewed from a direction perpendicular to the bonding surface of the second substrate 230 with the liquid supply member 240, the second substrate 230 has a first protrusion 800 that protrudes from the first substrate 220 in a first direction (X-axis direction). The second adhesive layer 702a is provided on the first protrusion 800.

[0066] The bonding surface 204a of the liquid dispensing tip 210 with the liquid supply member 240 (see Figure 11(a), etc.) includes a first region 701b where a first adhesive layer 701a containing a first adhesive 701 is provided. The bonding surface 204a also includes a second region 702b where a second adhesive layer 702a containing a second adhesive 702 having a coefficient of thermal expansion different from that of the first adhesive 701 is provided.

[0067] In the orientation in which the liquid discharge tip 210 is used, the second region 702b is provided at the end (first projection 800) in the first direction of the joint surface 204a, and is not provided directly above the liquid discharge section 200a, which includes the connecting channel 15 and the plurality of nozzles 3.

[0068] Specifically, in a cross-sectional view of the liquid dispensing unit 200, an adhesive layer 700 containing a cured adhesive is provided between the liquid dispensing tip 210 and the liquid supply member 240. The adhesive layer 700 includes a first adhesive layer 701a containing a cured first adhesive 701, and a second adhesive layer 702a containing a cured second adhesive 702. In a cross-sectional view of the liquid dispensing unit 200, the liquid supply member 240 has a second projection 900 that protrudes outward from the longitudinal (X-axis) end of the first substrate 220.

[0069] The liquid discharge unit 200 includes a liquid discharge section 200a containing a plurality of nozzles 3 (see Figure 9(a), etc.). The length of the liquid discharge section 200a in the X-axis direction is approximately equal to the length of the nozzle row in the X-axis direction. In the X-axis direction, the first adhesive layer 701a is provided inside the liquid discharge section 200a.

[0070] Outside the liquid discharge portion 200a, the second adhesive layer 702a is provided only on the first protrusion 800.

[0071] The amount of protrusion of the first protrusion 800 is preferably 1 / 2 or more of the amount of protrusion of the second protrusion 900, and less than 1.

[0072] For example, the ratio of the coefficients of linear expansion after heat curing in the first adhesive layer 701a and the second adhesive layer 702a may satisfy the following equation (Equation 1).

[0073] (Equation 1) ... Linear expansion coefficient of the first adhesive layer 701a : Linear expansion coefficient of the second adhesive layer 702a = 1:3

[0074] For example, the ratio of the elastic moduli after heat curing in the first adhesive layer 701a and the second adhesive layer 702a may satisfy the following equation (Equation 2).

[0075] (Equation 2) ... Elastic modulus of the first adhesive layer 701a : Elastic modulus of the second adhesive layer 702a = 10:7

[0076] Figure 14(a) is a graph showing the simulation results of the normal stress generated in the liquid discharge section 200a of this embodiment. In Figure 14(a), the dashed line S1 shows the simulation results of the normal stress generated in the liquid discharge section 200a (see Figure 11(b)) in this embodiment. The dotted line S' shows the simulation results of the normal stress generated in the liquid discharge section 200a (see Figure 12(b)) in the first comparative example. The dashed line S'' shows the simulation results of the normal stress generated in the liquid discharge section 200a (see Figure 13(b)) in the second comparative example.

[0077] Figure 14(b) is a schematic bottom view of the liquid discharge tip 210 applied to this embodiment. In Figure 14(b), "N0" to "NX" indicate the respective numbers of the multiple nozzles 3.

[0078] In this embodiment, when viewing the liquid discharge tip 210 from below, the nozzle number of the nozzle 3 located in the upper left corner is "N0". The nozzle number of the nozzle 3 located directly below and to the right of the nozzle 3 with nozzle number "N0" is "N1". The nozzle number of the nozzle 3 located directly below and to the right of the nozzle 3 with nozzle number "N1" is "N2". The nozzle number of the nozzle 3 located directly below and to the right of the nozzle 3 with nozzle number "N2" is "N3". The nozzle number of the nozzle 3 located fourth in the -X direction from the nozzle 3 with nozzle number "N0" is "N4". The nozzle number of the nozzle 3 located directly below and to the right of the nozzle 3 with nozzle number "N4" is "N5". The nozzle numbers are then assigned sequentially as described above.

[0079] In Figure 14(a), the horizontal axis of the graph corresponds to each of the multiple nozzle numbers shown in Figure 14(b).

[0080] On the other hand, the vertical axis of the graph shows the moving average of the vertical stress generated at a total of four locations in the liquid discharge section 200a, specifically at the nozzle and the three nozzles preceding it, in each of this embodiment, the first comparative example, and the second comparative example.

[0081] In this embodiment, "normal stress" refers to the stress that occurs along the X-axis direction, which is perpendicular to the Z-axis direction.

[0082] As described above using Figures 11(a) and 11(b), the first adhesive 701 and the second adhesive 702 (see Figure 11(a)) are made of different materials. If the first adhesive 701 and the second adhesive 702 are thermosetting adhesives, it is necessary to lower the temperature of the first adhesive layer 701a and the second adhesive layer 702a (see Figure 11(b)) after the first adhesive 701 and the second adhesive 702 have cured.

[0083] While the temperature of the first adhesive layer 701a and the second adhesive layer 702a is decreasing, this temperature change causes the first adhesive layer 701a and the second adhesive layer 702a to shrink. This shrinkage generates normal stress at the interface (boundary) between the first adhesive layer 701a and the second adhesive layer 702a.

[0084] Furthermore, the normal stress generated in the first adhesive layer 701a and the second adhesive layer 702a tends to be transmitted toward the nozzle surface 201a of the liquid discharge tip 210. This is because the liquid discharge tip 210 contains a relatively rigid material (e.g., silicon), making it difficult to absorb or dissipate the force it receives. Thus, the normal stress generated at the adhesive interface between the liquid discharge tip 210 and the liquid supply member 240, and the normal stress transmitted toward the nozzle surface 201a, are correlated.

[0085] As shown in Figures 14(a) and 14(b), the normal stress values ​​at both ends of the liquid discharge section 200a in the X-axis direction tend to be greater than the normal stress value at the center of the liquid discharge section 200a in the X-axis direction.

[0086] As shown in Figures 12(a) and 12(b), in the first comparative example, the length in the X-axis direction of the first substrate 220 and the length in the X-axis direction of the second substrate 230 were the same. That is, the first protrusion was not provided. Therefore, when a difference in vertical stress occurs in the adhesive layer 700, the difference between the vertical stress value at both ends of the liquid discharge portion 200a in the X-axis direction and the vertical stress value at the center of the liquid discharge portion 200a in the X-axis direction becomes large.

[0087] Furthermore, among the examples shown in Figure 14(a), the configuration of the first comparative example results in the largest vertical stress value acting on the liquid discharge section 200a. Therefore, with the configuration of the first comparative example, it becomes difficult to discharge the liquid stably.

[0088] As shown in Figures 13(a) and 13(b), in the second comparative example, the distance from the liquid discharge section 200a to the interface between the first adhesive 701 and the second adhesive 702 was greater compared to the first comparative example.

[0089] However, the length in the X-axis direction of the first substrate 220 and the length in the X-axis direction of the second substrate 230 were the same. In other words, the first protrusion was not provided. Therefore, when a normal stress occurs in the adhesive layer 700, the difference between the normal stress value at both ends of the liquid discharge portion 200a in the X-axis direction and the normal stress value at the center of the liquid discharge portion 200a in the X-axis direction becomes larger than in this embodiment.

[0090] Furthermore, among the examples shown in Figure 14(a), the configuration of the second comparative example results in the second largest vertical stress value acting on the liquid discharge section 200a. Therefore, with the configuration of the second comparative example, it becomes difficult to discharge the liquid stably.

[0091] As shown in Figures 11(a) and 11(b), in this embodiment, the interface between the first adhesive 701 and the second adhesive 702 is provided at a large distance from the liquid discharge section 200a, similar to the second comparative example. Furthermore, the length in the X-axis direction of the second substrate 230 is longer than the length in the X-axis direction of the first substrate 220.

[0092] With the first substrate 220 and the second substrate 230 joined together, the second adhesive layer 702a is provided on the first protrusions 800 that protrude from both ends of the first substrate 220 on the second substrate 230. With this configuration, since the liquid discharge section 200a is not located directly beneath the second adhesive layer 702a, even if vertical stress is generated in the second adhesive layer 702a, that vertical stress is less likely to be transmitted to the nozzle 3.

[0093] Furthermore, in this embodiment, the vertical stress is less likely to be transmitted not only to the nozzle 3 but also to the diaphragm 9 (see Figure 10(b)).

[0094] Furthermore, as shown in Figure 14(a), the variation in the normal stress values ​​in this embodiment is smaller than the variation in the normal stress values ​​in the first comparative example and the variation in the normal stress values ​​in the second comparative example.

[0095] Therefore, it can be seen that this embodiment shows more stable liquid discharge performance in the liquid discharge tip 210 compared to the first and second comparative examples.

[0096] <Manufacturing method> Figure 15 is a flowchart illustrating a method for manufacturing a liquid dispensing head 100 applicable to this embodiment. In Figure 15, the symbol "S" represents a step. Note that only characteristic steps of the technology of this disclosure are shown in Figure 15. Other steps may be performed using known methods.

[0097] In S1501, as described above using Figure 11(a), the first adhesive 701 is applied to the first region 701b of the bonding surface 204a of the liquid discharge tip 210.

[0098] In step S1502, as described above using Figure 11(a), a second adhesive 702, which has a different coefficient of thermal expansion than the first adhesive 701, is applied to the second region 702b of the bonding surface 204a of the liquid discharge tip 210. That is, the second adhesive 702 is applied to the first protrusion 800 of the bonding surface of the second substrate 230 with the liquid supply member 240, which protrudes in the first direction (X-axis direction) from the first substrate 220.

[0099] In step S1503, the liquid discharge tip 210 is joined to the liquid supply member 240 such that the connecting channel 15 formed in the liquid discharge tip 210 is connected to the supply channel 241 formed in the liquid supply member 240.

[0100] In S1504, the second adhesive 702 is cured with the liquid discharge tip 210 joined to the liquid supply member 240.

[0101] In step S1505, the first adhesive 701 is cured with the liquid discharge tip 210 joined to the liquid supply member 240.

[0102] The above is a description of the manufacturing method for the liquid dispensing head 100.

[0103] When performing the above-described steps, steps S1501 and S1502 may be performed in reverse order. Similarly, steps S1504 and S1505 may be performed in reverse order, but it is preferable that S1504 be performed before S1505. This is because this method makes it possible to fix the liquid discharge tip 210 to the liquid supply member 240 while the liquid discharge tip 210 is temporarily attached to the liquid supply member 240.

[0104] For example, if the first adhesive 701 and the second adhesive 702 are thermosetting adhesives, it is preferable to use the second adhesive 702 which hardens at room temperature or above, and the first adhesive 701 which hardens at a higher temperature than the second adhesive 702. In this way, steps S1504 and S1505 can be combined into a single heating step that heats the entire chip. In the heating step, when a predetermined temperature (first temperature) is reached, the second adhesive hardens first, and then when a second temperature higher than the first temperature is reached, the first adhesive hardens. Alternatively, if the second adhesive 702 is a UV-curing adhesive, it is preferable to irradiate the second adhesive 702 with UV light before hardening the first adhesive 701 to harden the second adhesive 702.

[0105] This method makes it possible to prevent the liquid dispensing tip 210 from shifting position while it is being fixed in place.

[0106] As described above, in this embodiment, the first adhesive 701 and the second adhesive 702 are applied to the bonding surface 204a of the liquid dispensing tip 210 with the liquid supply member 240. By curing the second adhesive 702 before the first adhesive 701, it becomes possible to fix the liquid dispensing tip 210 to the liquid supply member 240 in a temporarily fixed state.

[0107] On the other hand, the coefficient of linear expansion of the first adhesive 701 is different from that of the second adhesive 702. Therefore, when the first adhesive layer 701a, which is cured with the first adhesive 701, and the second adhesive layer 702a, which is cured with the second adhesive 702, expand, the difference in the normal stress acting on each of them may cause damage to the liquid dispensing tip 210.

[0108] Therefore, in this embodiment, a first adhesive 701 and a second adhesive 702 are used such that the difference in their perpendicular stresses is as small as possible. This reduces the risk of the liquid dispensing tip 210 being damaged due to the difference in perpendicular stresses between the first adhesive 701 and the second adhesive 702.

[0109] Furthermore, the vertical stress generated in the first adhesive layer 701a and the second adhesive layer 702a tends to act directly beneath them. However, in this embodiment, the second adhesive layer 702a is provided on the first protrusion 800 of the second substrate 230, which protrudes outward from the first substrate 220 on which the energy generating element 6 and nozzle 3 are provided. That is, in the orientation in which the liquid discharge tip 210 is used, the second adhesive layer 702a is not provided directly above the energy generating element 6 and nozzle 3.

[0110] Therefore, even if a vertical stress occurs in the second adhesive layer 702a, the energy generating element 6 and nozzle 3 are not directly beneath it, thus reducing the impact on liquid discharge.

[0111] Therefore, the liquid dispensing tip of this embodiment can suppress a decrease in liquid dispensing performance.

[0112] [Second Embodiment] This embodiment aims to provide a liquid dispensing tip 210 that can suppress the decrease in liquid dispensing performance compared to the first embodiment. In the following description, components that are the same as or corresponding to the first embodiment are denoted by the same reference numerals and their descriptions are omitted, while the differences are mainly described.

[0113] Figure 16 is a schematic plan view of the liquid dispensing tip 210 with an adhesive applied, which can be applied to this embodiment.

[0114] As shown in Figure 16, in this embodiment, when the liquid dispensing tip 210 is viewed from above, the second adhesive 702 is applied to the area inside a virtual circle B whose radius is a virtual straight line B1 connecting the corner of the first protrusion 800 and the corner of the liquid dispensing tip 200a closest to that corner. That is, it is desirable that the second adhesive 702 be applied only to both ends of the first protrusion 800 in the Y direction.

[0115] In this case, when the second adhesive 702 hardens, the second adhesive layer 702a is formed inside a virtual circle B whose radius is a virtual straight line B1 that connects the corner of the first protrusion 800 and the nozzle 3 closest to that corner, when the liquid dispensing tip 210 is viewed from above.

[0116] In this embodiment, the second adhesive layer 702a is provided only at both ends of the first protrusion 800 in the Y direction. The first adhesive 701 is applied to the central part of the first protrusion 800 in the Y direction. Therefore, in this embodiment, once the first adhesive 701 and the second adhesive 702 have hardened, the second adhesive layer 702a is provided only around the four corners of the joint surface 204a.

[0117] Then, the first adhesive layer 701a is provided in the central part of the bonding surface 204a and in the central part of the first protrusion 800. With this configuration, the area to which the second adhesive 702 is applied becomes smaller than in the first embodiment. Therefore, the difference between the vertical stress value of the first adhesive layer 701a and the vertical stress value of the second adhesive layer 702a at the adhesive interface between the liquid discharge tip 210 and the flow channel forming substrate 204 (see Figure 11(b), etc.) can be made smaller.

[0118] Figure 17(a) is a graph showing the simulation results of the normal stress generated in the liquid discharge section 200a of this embodiment. In Figure 17(a), the dashed line S2 represents the simulation results of the normal stress generated in the liquid discharge section 200a (see Figure 16) of this embodiment.

[0119] Figure 17(b) is a schematic bottom view of the liquid dispensing tip 210 applied to this embodiment.

[0120] As shown in Figures 17(a) and 17(b), the vertical stress value generated in the liquid discharge section 200a of this embodiment is smaller than the vertical stress value generated in the liquid discharge section 200a of the first embodiment.

[0121] Furthermore, in this embodiment, the difference between the vertical stress value at the center of the liquid discharge section 200a and the vertical stress values ​​at both ends is smaller than in the first embodiment. Thus, in this embodiment, the difference between the vertical stress value of the first adhesive layer 701a and the vertical stress value of the second adhesive layer 702a can be made even smaller.

[0122] Therefore, the liquid discharge tip 210 of this embodiment can suppress the decrease in liquid discharge performance compared to the first embodiment.

[0123] [Other embodiments] The above describes examples of how the technology of this disclosure may be applied. However, the above description does not limit the technical scope of this disclosure.

[0124] In the embodiments described above, an inkjet recording head and an inkjet recording apparatus that eject ink were specifically illustrated as examples. However, the scope to which the technology of this disclosure can be applied is not limited thereto.

[0125] The liquid ejection head and liquid ejection device of this disclosure are applicable to devices such as printers, copiers, facsimile machines with communication systems, word processors with printer units, and industrial recording devices that combine them with various processing devices. For example, they can also be used for applications such as biochip manufacturing and electronic circuit printing.

[0126] In the embodiments described above, a method of discharging liquid by driving a piezoelectric element was employed. However, the technology of this disclosure can also be applied to liquid discharging heads employing a thermal method that discharges liquid using bubbles generated by a heater element, and various other liquid discharging methods.

[0127] The above embodiments describe an inkjet recording device in which a liquid such as ink is circulated between a tank and a liquid ejection head. However, other forms of inkjet recording devices may be used. For example, an inkjet recording device may be used in which, instead of circulating the ink, two tanks are provided upstream and downstream of the liquid ejection head, and ink is flowed from one tank to the other to circulate the ink in the pressure chamber.

[0128] In the embodiments described above, a liquid dispensing device 10 equipped with a so-called full-line type liquid dispensing head 100 was shown. However, the technology of this disclosure can also be applied to a liquid dispensing device that performs recording by dispensing liquid onto a recording medium P using a liquid dispensing head that scans in a scanning direction intersecting the transport direction of the recording medium P in a plane. That is, the technology of this disclosure can also be applied to a liquid dispensing device equipped with a so-called serial type liquid dispensing head.

[0129] This disclosure includes the following configuration and method.

[0130] [Configuration 1] A first substrate on which a nozzle is formed for discharging liquid supplied from a liquid supply member, A second substrate having a connecting channel formed thereon that is connected to a supply channel formed in the liquid supply member, A liquid dispensing tip comprising, The bonding surface of the second substrate with the liquid supply member is provided with a first adhesive layer containing a first adhesive and a second adhesive layer containing a second adhesive. When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the second substrate has a protrusion that protrudes in a first direction from the first substrate, The second adhesive layer is provided on the protruding portion, A liquid dispensing tip characterized by the following features.

[0131] [Configuration 2] When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the first adhesive layer is provided near the connecting channel and in a position that overlaps with the nozzle. The liquid dispensing tip described in Configuration 1.

[0132] [Configuration 3] The physical properties of the first adhesive layer and the physical properties of the second adhesive layer are different from each other. A liquid dispensing tip as described in configuration 1 or 2.

[0133] [Structure 4] The coefficient of linear expansion of the first adhesive layer and the coefficient of linear expansion of the second adhesive layer are different from each other. The liquid dispensing tip described in configuration 3.

[0134] [Composition 5] The coefficient of thermal expansion of the first adhesive is at least 1.2 times greater than the coefficient of thermal expansion of the second adhesive. The liquid dispensing tip described in configuration 4.

[0135] [Composition 6] The coefficient of thermal expansion of the second adhesive is at least 1.2 times greater than the coefficient of thermal expansion of the first adhesive. The liquid dispensing tip described in configuration 4.

[0136] [Composition 7] The elastic modulus of the first adhesive layer and the elastic modulus of the second adhesive layer are different from each other. The liquid dispensing tip described in configuration 3.

[0137] [Structure 8] The elastic modulus of the first adhesive is at least 1.2 times greater than the elastic modulus of the second adhesive. Liquid dispensing tip as described in configuration 7.

[0138] [Composition 9] The elastic modulus of the second adhesive is at least 1.2 times greater than that of the first adhesive. Liquid dispensing tip as described in configuration 7.

[0139] [Configuration 10] The first adhesive has higher liquid resistance than the second adhesive. A liquid dispensing tip as described in any one of items 1 to 9 of the configuration.

[0140] [Composition 11] The first adhesive is a thermosetting adhesive, The second adhesive is a UV-curing, two-component mixture, or anaerobic curing adhesive. Liquid dispensing tip as described in configuration 10.

[0141] [Composition 12] The first adhesive and the second adhesive are thermosetting adhesives. The curing temperature of the second adhesive is lower than the curing temperature of the first adhesive. A liquid dispensing tip as described in any one of items 1 to 11 of the configuration.

[0142] [Composition 13] In the first direction viewed from a direction perpendicular to the bonding surface, the liquid supply member is longer than the second substrate, and the distance the second substrate protrudes from the edge of the first substrate is at least half and less than 1 of the distance the liquid supply member protrudes from the edge of the first substrate. A liquid dispensing tip as described in any one of configurations 1 to 12.

[0143] [Composition 14] The second adhesive layer is provided at both ends of the protruding portion in the second direction, which intersects the first direction in a plane. A liquid dispensing tip as described in any one of items 1 to 13 of the configuration.

[0144] [Composition 15] Each of the aforementioned ends is contained within a virtual circle whose radius is the virtual straight line connecting the corner of the protrusion and the nozzle closest to that corner, when the liquid discharge tip is viewed from above. Liquid dispensing tip as described in configuration 14.

[0145] [Composition 16] A liquid dispensing tip as described in any one of items 1 to 15, The liquid supply member and, A liquid dispensing head characterized by having the following features.

[0146] [Method 17] A method for manufacturing a liquid discharge unit comprising: a liquid supply member for supplying liquid; and a liquid discharge tip including a first substrate on which a nozzle for discharging the liquid supplied from the liquid supply member is formed, and a second substrate on which a connecting channel connected to a supply channel formed in the liquid supply member is formed, wherein the liquid discharge unit comprises: A coating step of applying a first adhesive and a second adhesive to the bonding surface of the second substrate with the liquid supply member, A bonding step in which the position of the liquid supply member and the position of the second substrate are aligned and the liquid supply member and the liquid discharge tip are joined together, A curing step for curing the first adhesive and the second adhesive, Includes, When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the second substrate has a protrusion that protrudes in a first direction from the first substrate, In the coating step, the second adhesive is applied to the protruding portion. A method for manufacturing a liquid dispensing head, characterized by the following:

[0147] [Method 18] In the coating step, the first adhesive is applied near the connecting channel. In the bonding process, with the liquid dispensing tip viewed from a direction perpendicular to the bonding surface, the first adhesive is positioned to overlap with the nozzle. The manufacturing method described in Method 17.

[0148] [Method 19] The physical properties of the first adhesive and the physical properties of the second adhesive are different from each other. The manufacturing method described in Method 17 or 18.

Claims

1. A first substrate on which a nozzle is formed for discharging liquid supplied from a liquid supply member, A second substrate having a connecting channel formed on it that is connected to a supply channel formed in the liquid supply member, A liquid dispensing tip comprising, The bonding surface of the second substrate with the liquid supply member is provided with a first adhesive layer containing a first adhesive and a second adhesive layer containing a second adhesive. When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the second substrate has a protrusion that protrudes in a first direction from the first substrate, The second adhesive layer is provided on the protruding portion, A liquid dispensing tip characterized by the following features.

2. When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the first adhesive layer is provided near the connecting channel and in a position that overlaps with the nozzle. The liquid dispensing tip according to claim 1.

3. The physical properties of the first adhesive layer and the physical properties of the second adhesive layer are different from each other. A liquid dispensing tip according to claim 1 or 2.

4. The coefficient of linear expansion of the first adhesive layer and the coefficient of linear expansion of the second adhesive layer are different from each other. The liquid dispensing tip according to claim 3.

5. The coefficient of thermal expansion of the first adhesive is at least 1.2 times greater than the coefficient of thermal expansion of the second adhesive. The liquid dispensing tip according to claim 4.

6. The coefficient of linear expansion of the second adhesive is 1.2 times or more greater than the coefficient of linear expansion of the first adhesive. The liquid dispensing tip according to claim 4.

7. The elastic modulus of the first adhesive layer and the elastic modulus of the second adhesive layer are different from each other. The liquid dispensing tip according to claim 3.

8. The elastic modulus of the first adhesive is at least 1.2 times greater than the elastic modulus of the second adhesive. The liquid dispensing tip according to claim 7.

9. The elastic modulus of the second adhesive is at least 1.2 times greater than the elastic modulus of the first adhesive. The liquid dispensing tip according to claim 7.

10. The first adhesive has higher liquid resistance than the second adhesive. A liquid dispensing tip according to claim 1 or 2.

11. The first adhesive is a thermosetting adhesive, The second adhesive is a UV-curing type, a two-component mixture type, or an anaerobic curing type adhesive. The liquid dispensing tip according to claim 10.

12. The first adhesive and the second adhesive are thermosetting adhesives. The curing temperature of the second adhesive is lower than the curing temperature of the first adhesive. A liquid dispensing tip according to claim 1 or 2.

13. In the first direction viewed from a direction perpendicular to the bonding surface, the liquid supply member is longer than the second substrate, and the distance the second substrate protrudes from the edge of the first substrate is 1 / 2 or more and less than 1 of the distance the liquid supply member protrudes from the edge of the first substrate. A liquid dispensing tip according to claim 1 or 2.

14. The second adhesive layer is provided at both ends of the protruding portion in the second direction, which intersects the first direction in a plane. A liquid dispensing tip according to claim 1 or 2.

15. Each of the aforementioned ends is contained within a virtual circle whose radius is the virtual straight line connecting the corner of the protrusion and the nozzle closest to that corner, when the liquid discharge tip is viewed from above. The liquid dispensing tip according to claim 14.

16. A liquid dispensing tip according to claim 1 or 2, The liquid supply member and, A liquid dispensing head characterized by having the following features.

17. A method for manufacturing a liquid discharge unit comprising: a liquid supply member for supplying liquid; and a liquid discharge tip including a first substrate on which a nozzle for discharging the liquid supplied from the liquid supply member is formed, and a second substrate on which a connecting channel connected to a supply channel formed in the liquid supply member is formed, wherein the liquid discharge unit comprises: A coating step of applying a first adhesive and a second adhesive to the bonding surface of the second substrate with the liquid supply member, A bonding step in which the position of the liquid supply member and the position of the second substrate are aligned and the liquid supply member and the liquid discharge tip are joined together, A curing step for curing the first adhesive and the second adhesive, Includes, When the liquid dispensing tip is viewed from a direction perpendicular to the bonding surface, the second substrate has a protrusion that protrudes in a first direction from the first substrate, In the coating step, the second adhesive is applied to the protruding portion. A method for manufacturing a liquid dispensing head, characterized by the following:

18. In the coating step, the first adhesive is applied near the connecting channel. In the bonding process, with the liquid dispensing tip viewed from a direction perpendicular to the bonding surface, the first adhesive is positioned to overlap with the nozzle. The manufacturing method according to claim 17.

19. The physical properties of the first adhesive and the physical properties of the second adhesive are different from each other. The manufacturing method according to claim 17 or 18.

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