Liquid dispensing head and method for manufacturing a liquid dispensing head

Abstract

To provide a liquid discharge head that can suppress large-sizing of a discharge head while arranging a capacitor near an element substrate in a liquid discharge device comprising the discharge head with the element substrate, and a liquid discharge head manufacturing method.SOLUTION: A liquid discharge device has: an element substrate for discharging a liquid; a support substrate which supports the element substrate; and a wiring board which is connected to the element substrate and on which a capacitor is mounted. The element substrate and the support substrate are connected. A support member includes a recess at a position facing the capacitor on a side face crossing a support face for supporting the element substrate.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a method for manufacturing the liquid ejection head.

Background Art

[0002] In a general liquid ejection device including an ejection head having an element substrate, high-speed processing is achieved by arranging a plurality of element substrates on the ejection head and performing many ejections simultaneously. A wiring substrate for supplying power and ejection signals is connected to each element substrate. In the case of an element substrate configured to eject liquid by the heat action of a heating resistor, ringing may occur when a large current flows through the wiring substrate. Due to this ringing, a large current may flow through the parasitic transistor of the field-effect transistor, which is a driving element, and the driving element may malfunction. In order to suppress the occurrence of such malfunctions, in the wiring substrate of the ejection head, it is common to arrange a capacitor near the connection portion with the element substrate.

[0003] In an ejection head, a capacitor mounted on a flexible wiring substrate is generally used. For such a capacitor, it is required to protect it from contact with ink by sealing it with a sealing agent and to provide it so as not to contact other members.

[0004] Patent Document 1 discloses a configuration in which, in an ejection head, the periphery of a capacitor mounted on a flexible wiring substrate is covered with a sealing agent, and this capacitor is arranged in a recess formed in a support member that supports the element substrate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the configuration of Patent Document 1, the capacitor is sealed with a sealing agent and is provided so as not to come into contact with other components. However, because the element substrate and the sealed capacitor are arranged side by side in the direction of the surface of the element substrate, it was difficult to reduce the size of the discharge head.

[0007] Therefore, the present invention provides a liquid discharge head and a method for manufacturing a liquid discharge head that can suppress the enlargement of the discharge head while arranging a capacitor near the element substrate. [Means for solving the problem]

[0008] Therefore, the liquid discharge head of the present invention comprises an element substrate that discharges liquid from a discharge port by the action of an element, a support member that supports the element substrate, a flexible wiring board electrically connected to the element substrate, and a capacitor mounted on the flexible wiring board. A sealing agent for sealing the aforementioned capacitor, A liquid dispensing head comprising the mounting portion for mounting the capacitor on the flexible wiring board is provided at an inclination with respect to the support surface of the support member that supports the element board, and the support member teeth , on the side surface intersecting the support surface 、 It has a recess Furthermore, the recess is provided on the side surface at a position opposite to the capacitor in a direction perpendicular to the surface of the flexible wiring board on which the capacitor is arranged, so as not to come into contact with the sealant. It is characterized by the following. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a liquid discharge head and a method for manufacturing a liquid discharge head that can suppress the enlargement of the discharge head while arranging a capacitor near the element substrate. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing a liquid dispensing device. [Figure 2] This is a perspective view showing the liquid dispensing head. [Figure 3] This is a cross-sectional view showing the area around the electrical wiring board in the liquid dispensing head. [Figure 4] This is a side view showing the second and third support members. [Figure 5] This is a cross-sectional view at VV in Figure 4. [Figure 6] This is a cross-sectional view from VI-VI in Figure 4. [Figure 7] This is a cross-sectional view of section VII-VII in Figure 4. [Figure 8] This is a perspective view showing the second and third support members. [Figure 9] This is a flowchart illustrating the manufacturing process of a liquid dispensing head. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. The following description is not intended to limit the scope of the present invention. As an example, in this embodiment, a thermal method is employed in which bubbles are generated by a heating element to discharge liquid, but the present invention can also be applied to liquid discharge heads employing a piezo method and various other liquid discharge methods.

[0012] Furthermore, this embodiment is a liquid dispensing device in which a liquid such as ink is circulated between a tank and a liquid dispensing head, but other configurations are also possible. For example, instead of circulating the ink, two tanks may be provided upstream and downstream of the liquid dispensing head, and the ink in the pressure chamber may be made to flow by flowing the ink from one tank to the other.

[0013] Furthermore, although the present embodiment is a so-called line-type head having a length corresponding to the width of the paper, the present invention can also be applied to a so-called serial-type liquid ejection head that ejects while moving with respect to the paper. Examples of the serial-type liquid ejection head include, but are not limited to, a configuration in which one element substrate for black ink and one element substrate for color ink are each mounted. That is, a short-line head shorter than the width of the paper may be created by arranging a plurality of element substrates so that the ejection ports overlap in the ejection port row direction, and the paper may be scanned with the short-line head.

[0014] FIG. 1 is a perspective view showing a liquid ejection apparatus 1000 to which the present embodiment can be applied. The liquid ejection apparatus 1000 includes a conveyance unit 1 that conveys a paper 2 and a line-type liquid ejection head 3 arranged substantially orthogonal to the conveyance direction of the paper, and is a line-type liquid ejection apparatus that performs ejection processing in one pass while continuously or intermittently conveying a plurality of papers 2. The paper 2 is not limited to cut paper and may be continuous roll paper. In the liquid ejection apparatus 1000, four single-color liquid ejection heads 3 corresponding to four types of CMYK inks are arranged in the conveyance direction of the paper 2 so that full-color liquid can be ejected. Note that FIG. 1 shows one single-color liquid ejection head 3.

[0015] The liquid ejection head 3 is fluidly connected to a main tank (not shown) and a buffer tank (not shown) via a supply path that supplies liquid to the liquid ejection head 3.

[0016] FIG. 2 is a perspective view showing the liquid ejection head 3. The liquid ejection head 3 is a page-wide head in which element substrates 100 for ejecting liquid are arranged in the X direction. The element substrate 100 generates bubbles by the mounted heating element to eject the liquid. Each element substrate 100 is electrically connected to an electric substrate 700 for controlling the ejection operation of the element substrate 100 via an electric wiring substrate 200. The electrical connection portions between the element substrate 100 and the electric wiring substrate 200 and between the electric wiring substrate 200 and the electric substrate 700 are each insulated and covered with a sealing member to suppress electrical failures due to liquid intrusion into the electrode portions. Each element substrate 100 and each electric wiring substrate 200 are each joined and fixed to a first support member 300 described later to constitute an ejection module. Each first support member 300 is joined and fixed to a second support member 400. The second support member 400 is joined and fixed to a third support member 600.

[0017] Liquid flow paths for supplying liquid to each element substrate 100 are formed in the first support member 300 and the second support member 400. A cover member 800 that forms a surface against which a suction recovery cap for removing bubbles in the flow path abuts is disposed around the element substrate 100.

[0018] Figure 3 is a cross-sectional view showing the area around the electrical wiring board 200 in the liquid discharge head 3. The electrical wiring board 200 is a flexible wiring board. One end of the electrical wiring board 200 is electrically connected to the element substrate 100, and the region including the connection is joined to the first support member 300 at the first surface (support surface) 901. A portion of the electrical wiring board 200 that is a predetermined distance away from the connection is joined to the second support member 400 at the third surface 903 of the second support member 400. The third surface 903 is a surface that is substantially perpendicular to the first surface 901. The adhesive used to join the electrical wiring board 200 to the third surface 903 preferably has a lower elastic modulus than the adhesive used to join the electrical wiring board 200 to the first surface 901. The electrical wiring board 200 and the second surface 902 of the second support member 400, which is substantially horizontal to the first surface 901, may be bonded together with an adhesive having a lower elastic modulus than the adhesive used to bond the electrical wiring board 200 and the first surface 901, or the bond may be filled with a sealant. However, this bonding is not mandatory.

[0019] Figure 4 is a side view showing the second support member 400 and the third support member 600. Figure 5 is a cross-sectional view of VV in Figure 4. Note that in Figure 4, the electrical wiring board 200 is omitted for clarity. As shown in Figure 5, a capacitor (electronic component) 201 is mounted on the electrical wiring board 200 near the connection point with the element board 100 (mounting area), and the mounted capacitor 201 is covered with a sealant 202. The capacitor 201 is positioned near the element board 100 to stabilize the driving voltage of the heating element and suppress the occurrence of malfunctions. The electrical wiring board 200 is bonded to the first support member 300 at the first bonding area 203, for example, by an adhesive, and to the second support member 400 at the second bonding area 204, for example, by an adhesive. The second bonding area 204 is the bonding area between the electrical wiring board 200 and the second surface 902 and third surface 903 of the second support member 400 (see Figure 3). Furthermore, the electrical wiring board 200 is bonded to the electrical substrate 700, for example, by double-sided tape, at a third adhesive portion 205 located further away from the connection portion with the element substrate 100 than the second adhesive portion 204. The electrical wiring board 200 is not particularly fixed at the location where the capacitor 201 is mounted, which is between the second adhesive portion 204 and the third adhesive portion 205.

[0020] In order to reduce the width in the Y direction of the liquid dispensing device 1000, a portion of the space between the second adhesive portion 204 and the third adhesive portion 205 of the electrical wiring board 200 is tilted. The electrical wiring board 200 is bonded and fixed between the second adhesive portion 204 and the third adhesive portion 205 with a length margin. At the curved portion 206 of the electrical wiring board 200, if the angle between the electrical wiring board 200 and the virtual surface 207, which is an extension of the surface of the electrical board 700 from the third adhesive portion 205 in the -Z direction, is small, the length margin of the electrical wiring board 200 increases. As a result, the displacement range due to vibrations during the operation of the liquid dispensing device 1000 increases at the location where the capacitor 201 of the electrical wiring board 200 is mounted, making it less likely for tension to be applied to the electrical wiring board 200.

[0021] Furthermore, at the bent portion 206 of the electrical wiring board 200, if the angle between the virtual surface 207, which is an extension of the surface of the electrical board 700 from the third adhesive portion 205 in the -Z direction, and the electrical wiring board 200 is large, there will be insufficient length in the electrical wiring board 200. As a result, the area in which displacement is possible due to vibrations during the operation of the liquid dispensing device 1000 will be small, and tension will be more likely to be applied to the electrical wiring board 200, which may cause the electrical wiring board 200 to break. For this reason, at the bent portion 206 of the electrical wiring board 200, it is desirable that the angle between the virtual surface 207, which is an extension of the surface of the electrical board 700 from the third adhesive portion 205 in the -Z direction, and the electrical wiring board 200 be between 20 degrees and 60 degrees.

[0022] If the second support member 400 comes into contact with the sealant 202 of the capacitor 201 mounted on the electrical wiring board 200, vibrations during the operation of the liquid dispensing device 1000 may cause damage to the capacitor 201 or cause the wiring on the electrical wiring board 200 to break due to the impact of contact. However, if the thickness of the second support member 400 is reduced to avoid interference between the sealant 202 and the second support member 400, its strength will decrease. Also, if the sealant 202 of the capacitor 201 is positioned sufficiently far from the second support member 400 in order to prevent contact with the sealant 202 of the capacitor 201 while maintaining the thickness of the second support member 400, the width of the liquid dispensing head in the Y direction will increase.

[0023] Furthermore, in order to suppress ringing, the capacitor 201 must be placed as close as possible to the element substrate 100. In order to avoid interference with the second support member 400, the mounting position of the capacitor 201 cannot be too far from the element substrate 100.

[0024] Therefore, in this embodiment, as shown in Figure 5, a recess 412 is provided on the side surface of the second support member 400 (the surface that intersects with the support surface that supports the element substrate 100) at the location where the encapsulant 202 of the capacitor 201 and the second support member 400 interfere. The width of the recess 412 in the X direction is wide enough to allow for sufficient width separation of the electrical wiring board 200 to avoid contact with the electrical wiring board 200 during vibration. By providing the recess 412 in this way, contact between the encapsulant 202 of the capacitor 201 and the second support member 400 can be avoided.

[0025] Figure 6 is a cross-sectional view of section VI-VI in Figure 4, and Figure 7 is a cross-sectional view of section VII-VII in Figure 4. In areas where the encapsulant 202 of the capacitor 201 and the second support member 400 do not interfere with each other, a thickened section 410 is provided on the side of the second support member 400 to maintain strength, as shown in Figure 6. As shown in Figure 7, a thinned section 411 with an internal space is provided in part of the thickened section 410 to improve moldability. Here, the wall thickness (width in the Y direction) of the wall forming the thickened section 410 is 6.8 mm, the wall thickness (width in the Y direction) of the wall forming the thinned section 411 is 2.3 mm, and the wall thickness of the wall forming the recess 412 is 1.5 mm.

[0026] As shown in Figure 5, the second support member 400 has an elongated U-shape that opens in the Z direction, and is therefore prone to warping deformation where the sides collapse inward due to shrinkage during molding. To mitigate this warping deformation, the second support member 400 is provided with an inclined portion 401 connecting the top surface 402 and the side surface 403. The inclined portion 401 is provided so as to connect the top surface 402 and the portion of the side surface 403 that is more than half the height in the Z direction, and the angle between the top surface 402 and the inclined portion 401 is preferably 20 degrees or more and less than 60 degrees.

[0027] Figure 8 is a perspective view showing the second support member 400 and the third support member 600. Note that in Figure 8, the electrical wiring board 200 is partially omitted, and the electrical board 700 is also omitted.

[0028] Although there is no inclined portion on the side portion opposite to side portion 403, as shown in Figure 8, on the side portion opposite to side portion 403, the recess 412 is provided between the thin portion 411 and the thick portion 410, resulting in an uneven shape with alternating thin and thick portions 411 and 410. Therefore, the shape is less prone to warping deformation.

[0029] The mounting position of the capacitor 201 on the electrical wiring board 200 is preferably near the element board 100, and preferably on the electrical wiring board 200, it is preferably mounted closer to the element board 100 than the center between the element board 100 and the electrical board 700. In this embodiment, for example, it is mounted at a position where the ratio of the element board 100 side to the electrical board 700 side is 2:3. Since the capacitor 201 is used in a 30V power line, its rated voltage is 50V and its capacitance is, for example, 10μF.

[0030] Thus, a recess 412 is formed on the side of the second support member 400, opposite the capacitor 201. This makes it possible to provide a liquid discharge head and a method for manufacturing a liquid discharge head that can suppress the enlargement of the discharge head while placing the capacitor in the vicinity of the element substrate. In the above, a single capacitor was used as an example of an electronic component to suppress the effect of ringing, but the electronic components applicable to the present invention are not limited to this. Any configuration that suppresses the effect of ringing may include a circuit that includes resistors and inductors in addition to capacitors.

[0031] Figure 9 is a flowchart showing an example of the manufacturing process for the liquid discharge head 3. The symbol "S" in the description of each process indicates a step in the flowchart. In the manufacturing of the liquid discharge head 3, first, in S01, the element substrate 100 is joined to the first support member 300 using an adhesive. In S02, the adhesive is cured by heat treatment. Then, in S03, one end of the electrical wiring board 200 is joined to the first support member 300 with an adhesive on the first surface 901. In S04, the electrical wiring board 200 is wire-bonded to the element substrate 100. Then, in S05, a sealant is applied to cover the wire-bonded portion.

[0032] In S06, the adhesive and sealant are cured by heat treatment. In S07, the first support member 300 is bonded to the second support member 400 using the adhesive. Then, in S08, the electrical circuit board 700 and the electrical wiring board 200 are bonded together with double-sided tape. In S09, the electrical circuit board 700 is electrically connected to the terminals of the electrical wiring board 200 by wire bonding. In S10, a sealant is applied to the wire bonding portion of the electrical wiring board 200 to cover it.

[0033] Then, in S11, the sealant is cured by heat treatment. After that, in S12, with the capacitor 201 mounted on the electrical wiring board 200 positioned to face the recess 412 formed in the second support member 400, the electrical wiring board 200 is joined to the second support member 400 using adhesive. Then, in S13, the cover member 800 is joined to the second support member 400 using adhesive. At this time, both the cover member 800 and the electrical wiring board 200 are joined with adhesive. After that, a sealant is applied between the cover member 800 and the element substrate 100 to complete the liquid discharge head 3.

[0034] This embodiment includes the following configurations and methods.

[0035] (Composition 1) A device substrate that discharges liquid through the action of the element, A support member that supports the element substrate, A wiring board electrically connected to the element substrate, A capacitor mounted on the aforementioned wiring board, A liquid dispensing head equipped with, A liquid dispensing head characterized in that a recess is formed on the side surface of the support member that intersects with the support surface that supports the element substrate, at a position facing the capacitor.

[0036] (Configuration 2) The liquid discharge head according to configuration 1, wherein the capacitor is sealed with a sealing agent.

[0037] (Composition 3) A device substrate that discharges liquid through the action of the element, A support member that supports the element substrate, A wiring board electrically connected to the element substrate, An electronic component mounted on the aforementioned wiring board for stabilizing the ejection on the element board, A liquid dispensing head equipped with, A liquid dispensing head characterized in that a recess is formed on the side surface of the support member that intersects with the support surface that supports the element substrate, at a position facing the electronic component.

[0038] (Composition 4) The liquid dispensing head according to configuration 3, wherein the electronic component is a capacitor that stabilizes the drive voltage applied to the element.

[0039] (Composition 5) The liquid discharge head according to configuration 1 or 4, wherein the wiring board is a flexible wiring board.

[0040] (Composition 6) The liquid discharge head according to configuration 5, wherein the mounting portion for mounting the capacitor on the flexible wiring board is provided at an inclination with respect to the support surface.

[0041] (Composition 7) The liquid dispensing head according to configuration 1 or 3, wherein the support member has an inclined portion between the support surface and the side surface that is inclined with respect to the support surface.

[0042] (Composition 8) The liquid discharge head according to configuration 7, wherein the inclined portion has an inclination of 20 degrees or more and less than 60 degrees with respect to the support surface.

[0043] (Composition 9) The liquid dispensing head according to configuration 1 or 4, wherein the wiring board is bonded at a first bonding portion that is bonded to the element board, a second bonding portion that is bonded to the support member, and a third bonding portion that is bonded to an electrical board for controlling the dispensing operation of the element board, and the capacitor is provided between the second bonding portion and the third bonding portion.

[0044] (Composition 10) The liquid discharge head according to configuration 1 or 3, wherein the side surface comprises a thick-walled portion and a thin-walled portion at positions different from the recess.

[0045] (Composition 11) The liquid dispensing head according to configuration 10, wherein the recess is provided between the thick-walled portion and the thin-walled portion, and the thick-walled portion and the thin-walled portion are arranged alternately.

[0046] (Composition 12) A liquid dispensing head according to configuration 1 or 3, comprising a cover member surrounding the element substrate.

[0047] (Composition 13) The support member comprises a first support member and a second support member. The element substrate is joined to the first support member, The second support member is joined to the first support member, The recess is a liquid dispensing head according to configuration 1 or 3 of the second support member.

[0048] (Composition 14) The liquid dispensing head according to configuration 13, wherein the second support member is formed by arranging and joining a plurality of the first support members.

[0049] (Method 1) A device substrate that discharges liquid through the action of the element, A support member that supports the element substrate, A wiring board electrically connected to the element substrate, An electronic component mounted on the aforementioned wiring board to stabilize the ejection on the element board, A method for manufacturing a liquid dispensing head equipped with, A step of electrically connecting the wiring board and the element board, A step of bonding the element substrate to the support surface of the support member, The steps include: positioning the wiring board on the side surface such that the electronic components mounted on the wiring board face a recess formed on the side surface of the support member that intersects with the support surface; A method for manufacturing a liquid dispensing head, characterized by having the following features. [Explanation of Symbols]

[0050] 100 element substrate 200 Electrical wiring boards 201 Capacitor 202 Encapsulating agent 400 Second support member 412 recess 1000 liquid dispensing device

Claims

1. A device substrate that discharges liquid from a discharge port due to the action of the element, A support member that supports the element substrate, A flexible wiring board electrically connected to the element substrate, A capacitor mounted on the aforementioned flexible wiring board, A sealing agent for sealing the aforementioned capacitor, A liquid dispensing head equipped with, The mounting portion for mounting the capacitor in the flexible wiring board is provided at an inclination with respect to the support surface of the support member that supports the element substrate, The support member has a recess on the side surface that intersects with the support surface, The liquid dispensing head is characterized in that the recess is provided on the side surface at a position opposite to the capacitor in a direction perpendicular to the surface of the flexible wiring board on which the capacitor is arranged, so as not to come into contact with the sealant.

2. The liquid discharge head according to claim 1, wherein the support member has a channel for supplying liquid to the element substrate.

3. The liquid dispensing head according to claim 1, wherein the support member comprises an inclined portion between the support surface and the side surface that is inclined with respect to the support surface.

4. The liquid dispensing head according to claim 3, wherein the inclined portion has an inclination of 20 degrees or more and less than 60 degrees with respect to the support surface.

5. The liquid dispensing head according to claim 1, wherein the flexible wiring board is bonded at a first bonding portion bonded to the element board, a second bonding portion bonded to the support member, and a third bonding portion bonded to an electrical board for controlling the dispensing operation of the element board, and the capacitor is provided between the second bonding portion and the third bonding portion.

6. The liquid discharge head according to claim 2, wherein the side surface comprises a thick-walled portion with a greater thickness up to the flow path and a thin-walled portion with a less thickness up to the flow path, at positions different from the recess.

7. The liquid dispensing head according to claim 6, wherein the recess is provided between the thick-walled portion and the thin-walled portion, and the thick-walled portion and the thin-walled portion are arranged alternately.

8. The liquid dispensing head according to claim 1, further comprising a cover member surrounding the element substrate.

9. The support member comprises a first support member and a second support member. The element substrate is joined to the first support member, The second support member is joined to the first support member, The recess is a liquid dispensing head according to claim 1, which is provided by the second support member.

10. The liquid dispensing head according to claim 9, wherein the second support member is formed by arranging and joining a plurality of the first support members.

11. The liquid dispensing head according to claim 1, wherein the element is a heating element.

12. A device substrate that discharges liquid from a discharge port due to the action of the element, A support member that supports the element substrate and has a channel for supplying liquid to the element substrate, A flexible wiring board electrically connected to the element substrate, The electronic components mounted on the aforementioned flexible wiring board, A sealing agent for sealing the aforementioned electronic component, A liquid dispensing head equipped with, The mounting portion for mounting the electronic components in the flexible wiring board is provided at an inclination with respect to the support surface of the support member that supports the element substrate, The support member has a recess on the side surface that intersects with the support surface, The liquid dispensing head is characterized in that the recess is provided on the side surface at a position opposite to the capacitor in a direction perpendicular to the surface of the flexible wiring board on which the capacitor is arranged, so as not to come into contact with the sealant.

13. The liquid dispensing head according to claim 12, wherein the electronic component is a capacitor that stabilizes the drive voltage applied to the element.

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