Liquid ejection head and method for manufacturing liquid ejection head

Abstract

To improve reliability of a liquid discharge head.SOLUTION: The liquid ejection head includes an element substrate that ejects a liquid in response to an electric signal, a support member that supports the element substrate, and a flexible wiring substrate that is fixed to the support member and supplies the electric signal to the element substrate. On a surface where the support member supports the element substrate, the flexible wiring substrate includes a fixed portion fixed to the support member by an adhesive and a non-fixed portion not fixed to the support member. The flexible wiring board is bent from a position included in the non-fixed part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] When manufacturing a liquid ejection head that ejects liquid, a flexible wiring board having flexibility may be bent to fit the shape of a housing and then attached to the housing.

[0003] Patent Document 1 discloses a liquid ejection head including a housing in which a recess is formed and an electric wiring board (flexible wiring board) fixed to the housing in a bent state, and a method for manufacturing the same.

[0004] According to the manufacturing method of Patent Document 1, in the process of attaching the electric wiring board to the housing, any bending of the electric wiring board is accommodated inside a recess formed in the housing. Therefore, the manufacturing method of Patent Document 1 and the liquid ejection head manufactured by this manufacturing method can prevent the electric wiring board fixed to the housing from floating. This in turn can prevent the floating electric wiring board from contacting other components and impairing the electrical safety of the liquid ejection head. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-093452 Summary of the Invention [Problem to be solved by the invention]

[0006] In the housing of Patent Document 1, the electrical wiring board is bonded to the side of the housing where the recording element board (element board) is attached with an adhesive. If, for some reason, the adhesive overflows from the housing when it is applied, the electrical wiring board will bend from the part of the applied adhesive that overflowed. If the electrical wiring board is bent in this state, the electrical wiring board will be attached to the housing in a state where the above-mentioned floating occurs. As such, the technology of Patent Document 1 leaves room for improvement.

[0007] Furthermore, when the electrical wiring board is bent at the adhesive, excessive stress is applied to the electrical wiring board, which may cause damage to the electrical wiring board, which may lead to electrical problems.

[0008] Therefore, an object of the present disclosure is to provide a technique that can improve the reliability of flexible wiring boards. [Means for solving the problem]

[0009] The liquid ejection head of the present disclosure comprises an element substrate that ejects liquid in response to an electrical signal, a support member that supports the element substrate, and a flexible wiring substrate that is fixed to the support member and supplies an electrical signal to the element substrate, and is characterized in that, on the surface where the support member supports the element substrate, the flexible wiring substrate includes a fixed portion that is fixed to the support member with an adhesive and a non-fixed portion that is not fixed to the support member, and the flexible wiring substrate is bent starting from a position included in the non-fixed portion. [Effects of the Invention]

[0010] According to the technology of the present disclosure, the reliability of the flexible wiring board can be improved. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of a liquid ejection apparatus that can be applied to an embodiment. [Figure 2] FIG. 1 is an exploded perspective view showing an example of a liquid ejection head that can be applied to an embodiment. [Figure 3] FIG. 1 is a perspective view showing an example of a liquid ejection head that can be applied to an embodiment. [Figure 4] FIG. 1 is a cross-sectional view showing an example of a liquid ejection head that can be applied to an embodiment. [Figure 5] FIG. 1 is a cross-sectional view showing an example of a flexible wiring board that can be applied to an embodiment. [Figure 6] 10 is a flowchart showing an example of a manufacturing process for a liquid ejection head that can be applied to an embodiment. [Figure 7] 5A to 5C are diagrams illustrating a manufacturing process of a liquid ejection head that can be applied to an embodiment. [Figure 8] 5A to 5C are diagrams showing a reference example of a manufacturing process for a liquid ejection head. [Figure 9] FIG. 10 is a cross-sectional view showing a modified example of the liquid ejection head. [Figure 10] FIG. 1 is a cross-sectional view showing an example of a liquid ejection head that can be applied to an embodiment. [Figure 11] FIG. 1 is an explanatory diagram of a liquid ejection head that can be applied to an embodiment. [Figure 12] FIG. 1 is an explanatory diagram of a liquid ejection head that can be applied to an embodiment. [Figure 13] 5A to 5C are diagrams illustrating a manufacturing process of a liquid ejection head that can be applied to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] Fig. 1(a) is a schematic perspective view showing an example of a liquid ejection apparatus 100 that can be applied to this embodiment, Fig. 1(b) is a block diagram of a control system of the liquid ejection apparatus 100.

[0013] The coordinate axes in the figure will be explained. The ±X direction indicates the main scanning direction of the liquid ejection head 101. The +Y direction is the transport direction of the recording medium P. The +Y direction will be referred to as the transport direction as appropriate. The -Y direction is the opposite direction to the +Y direction. The Z direction indicates the height direction of the liquid ejection head 101. The -Z direction is the direction in which liquid (e.g., ink) is ejected from the liquid ejection head 101. The +Z direction is the opposite direction to the -Z direction. When the liquid ejection head 101 is attached to the device, the ±X direction is the width direction of the liquid ejection head 101, the ±Y direction is the depth direction of the liquid ejection head 101, and the ±Z direction is the height direction of the liquid ejection head 101.

[0014] In this embodiment, the description will be made assuming that ink is used as the liquid. However, the liquid that can be used in the technology of the present disclosure is not limited to ink. In addition to ink, various recording liquids can be used as the liquid, including treatment liquids used for the purposes of improving the fixation of ink on the recording medium P, reducing uneven gloss, and improving abrasion resistance.

[0015] The liquid ejection device 100 shown in FIG. 1(a) is a serial scan type inkjet printer in which a liquid ejection head 101 ejects ink while performing a scanning motion to record an image or the like on a recording medium P. The liquid ejection head 101 is mounted on a carriage 102. The carriage 102 moves in the main scanning direction (±X direction) along a guide shaft 103. The recording medium P is transported in a transport direction (+Y direction) that intersects (in this example, orthogonal to) the main scanning direction by transport rollers 104, 105, 106, and 107.

[0016] The liquid ejection head 101 is equipped with a circulation unit 108, which circulates the liquid in an ejection unit 204 (see FIG. 2), which will be described later. The recording elements (which will be described later) provided in the ejection unit 204 are driven by a head driver 121 in response to input signals received from the main body by a contact wiring board 211 (see FIG. 2). Electrical wiring required for ejection and liquid piping are supplied to the carriage 102 by a guide 109.

[0017] The CPU 122, which functions as a control unit, controls the liquid ejection device 100 based on programs such as processing procedures stored in the ROM 123. The RAM 124 is used as a work area for executing these processes. The CPU 122 controls the head driver 121 based on image data from a host device 125 external to the liquid ejection device 100.

[0018] The CPU 122 also controls, via a first motor driver 126, a carriage motor 127 for moving the carriage 102. The CPU 122 also controls, via a second motor driver 128, a conveying motor 129 for conveying the recording medium P.

[0019] The liquid ejection head 101 is configured to be capable of full-color printing using CMYK (cyan, magenta, yellow, and black) inks. Examples of liquids ejected by the liquid ejection head 101 are not limited to these. The liquid ejection head 101 may be configured to eject white ink and reaction liquid, or may be configured to eject only black ink.

[0020] A cap member (not shown) is disposed at a position away from the conveyance path of the recording medium P. When liquid ejection is not being performed, the cap member moves relatively to a position where it covers the face of the liquid ejection head 101. With the face covered by the cap member, a suction operation is performed to prevent drying at the ejection port 300 (see FIG. 3), fill the ejection port 300, and perform recovery.

[0021] FIG. 2 is a schematic exploded perspective view of the liquid ejection head 101 that can be applied to this embodiment, viewed from the connecting member 202 side.

[0022] 2, the liquid ejection head 101 has a circulation unit 108. The circulation unit 108 includes a circulation unit 108m, a circulation unit 108y, a circulation unit 108k, and a circulation unit 108c corresponding to magenta ink, yellow ink, black ink, and cyan ink, respectively.

[0023] The circulation unit 108 is connected to a flow path member 201 that functions as a housing for the liquid ejection head 101. The circulation unit 108 and the flow path member 201 can be connected using any connection method. For example, the circulation unit 108 and the flow path member 201 can be connected by screwing with a sealing member sandwiched between them, or by welding, etc. A connection member 202 having a supply port 203 for receiving liquid from the apparatus main body is attached to the flow path member 201. The connection member 202 is in communication with each of the circulation units 108 (108m, 108y, 108k, and 108c).

[0024] When the liquid ejection head 101 is attached to the apparatus body, a supply tube (not shown) corresponding to the type of liquid to be ejected is connected to the supply port 203. The supply tube is provided in a guide 109 (see FIG. 1(a)). Each liquid supplied from each of these supply tubes passes through a connecting member 202 and is supplied to each circulation unit 108. A discharge unit 204 is connected to the bottom surface (the surface in the -Z direction) of the flow path member 201, and the liquid supplied to the circulation unit 108 passes through the flow path member 201 and is supplied to the discharge unit 204.

[0025] The discharge unit 204 can be fixed to the flow path member 201 using any method. For example, the discharge unit 204 may be adhered to the flow path member 201 using an adhesive, or may be fastened with screws with a sealing member sandwiched therebetween.

[0026] The ejection unit 204 includes an element substrate 205 including recording elements that generate energy for ejecting liquid, a cover member 208 that covers the flexible wiring substrate 206, and the flexible wiring substrate 206. The ejection unit 204 includes a support member 207 that supports the element substrate 205 and the flexible wiring substrate 206. A flow path 210 that supplies liquid from the circulation unit 108 to the element substrate 205 is formed in the support member 207.

[0027] An electrical signal sent from the mounting body to the contact wiring board 211 is sent to the element substrate 205 via the flexible wiring board 206. An opening for exposing the element substrate 205 is formed in the cover member 208 at a location corresponding to the element substrate 205. An opening is formed in the flexible wiring board 206 at a location corresponding to the element substrate 205. The element substrate 205 is adhered so as to be positioned inside these openings. In the configuration of this embodiment shown in FIG. 2, the element substrate 205 is not covered by the cover member 208.

[0028] 3(a) is a schematic perspective view of a liquid ejection head 101 that can be applied to this embodiment, viewed from the side of the contact wiring substrate 211. In FIG. 3(a), the surface that ejects liquid faces upward in the drawing.

[0029] In the element substrate 205 shown in Figure 3(a), a plurality of printing elements for ejecting liquid and electrical wiring for supplying power to each printing element are formed on a silicon substrate using film formation technology. A plurality of flow paths and a plurality of ejection ports 300 corresponding to the printing elements are formed using photolithography technology. A single ejection port array 301 is formed by arranging the plurality of ejection ports 300 along the Y direction. In addition, liquid supply ports (openings) for supplying liquid to each of the plurality of ejection port arrays 301 are formed on the back surface of the element substrate 205 (the surface facing the +Z direction in Figure 3(a)) in a number corresponding to the type of liquid to be ejected.

[0030] Furthermore, in the element substrate 205, the liquid supply port and the space formed within the support member 207 form a liquid chamber (not shown) that holds the liquid.

[0031] In this embodiment, a plurality of element substrates 205 (specifically, two) are attached to a support member 207. Each of these element substrates 205 is configured to be able to eject a plurality of types of liquid. A plurality of ejection ports 300 for ejecting liquid are formed in the element substrate 205. A printing element (for example, an electrothermal conversion element) is provided so as to correspond to each of these ejection ports 300. An example of an electrothermal conversion element is a heater.

[0032] The element substrate 205 and the flexible wiring substrate 206 are electrically connected. The support member 207 supports the element substrate 205 and the flexible wiring substrate 206 so that the electrical connection between the flexible wiring substrate 206 and the element substrate 205 is maintained. The flexible wiring substrate 206 is electrically connected to the contact wiring substrate 211. In this way, in this embodiment, the flexible wiring substrate 206 and the contact wiring substrate 211 form an electrical wiring section.

[0033] The contact wiring substrate 211 includes terminals 302 (for example, contact pads that function as electrical contacts) for receiving an electrical signal input from the device main body. The contact wiring substrate 211 is positioned and fixed to the back side of the flow path member 201 (the surface facing the -Y direction in FIG. 3(a)). The flow path member 201 is integrally molded, and has a flow path (not shown) formed therein that is connected to the flow path 210 (see FIG. 2). An electrical signal for ejecting liquid is input from the device main body to the element substrate 205 via the contact wiring substrate 211 and the flexible wiring substrate 206.

[0034] 3(b) is a schematic perspective view of the liquid ejection head 101 applicable to this embodiment, viewed from the side of the connecting member 202. In FIG. 3(b), the surface that ejects liquid faces downward in the drawing.

[0035] 3(b), the circulation unit 108 is detachably attached to the flow path member 201. The flow path member 201 is attached with a connection member 202 having a flow path connected to the circulation unit 108.

[0036] Fig. 4(a) is a cross-sectional view taken along line IVa-IVa in Fig. 3. For convenience of explanation, the following description will be given with the bottom surface (surface from which liquid is ejected) of the liquid ejection head 101 facing upward (+Z direction) in the drawing.

[0037] 4(a), the liquid ejection head 101 includes an element substrate 205 that ejects liquid in response to an electrical signal supplied from the outside, a support member 207 that supports the element substrate 205, and a flexible wiring substrate 206. The flexible wiring substrate 206 is fixed to the support member 207 in a state where it is bent along the support member 207.

[0038] The support member 207 has a first support surface 413 (a surface facing the -Z direction in FIG. 4(a)) that supports the flow path member 201, and a second support surface 414 (a surface facing the +Z direction in FIG. 4(a)) that supports the flexible wiring board 206. An adhesive 410 is applied to a portion of the second support surface 414, thereby bonding the support member 207, the flexible wiring board 206, the element substrate 205, and the cover member 208 together.

[0039] FIG. 4(b) is an enlarged view of region IVb in FIG. 4(a).

[0040] 4(b), on the surface where the support member 207 supports the element substrate 205, the flexible wiring board 206 includes a fixed portion 421 that is fixed to the support member 207 with an adhesive 410, and a non-fixed portion 422 that is not fixed to the support member 207. The flexible wiring board 206 is bent using a position included in the non-fixed portion 422 as a starting point 423. In this embodiment, the starting point refers to a point where the flexible wiring board 206, which extends linearly along a predetermined direction (the Y direction in this embodiment), starts to bend.

[0041] A cover member 208 that covers the flexible wiring board 206 but does not cover the element substrate 205 is adhered to the flexible wiring board 206 using an adhesive 410. That is, the cover member 208 has an opening that exposes the element substrate 205. A space 412 that can contain the adhesive 410 is formed in the cover member 208. In a cross-sectional view of the liquid ejection head 101, a part of the space 412 and a part of the fixing portion 421 overlap in the height direction (Z direction).

[0042] In this embodiment, the space 412 is a cutout of the cover member 208 formed so that the surface of the cover member 208 facing the flexible wiring board 206 is spaced apart in the +Z direction. The space 412 is formed near the starting point 423. For example, the cutout of the cover member 208 is formed so as to be located between the starting point 423 and the element substrate 205 in a direction parallel to the first support surface 413.

[0043] In the support member 207, a groove 411 capable of accommodating the adhesive 410 is preferably formed between the fixed portion 421 and the non-fixed portion 422. In a cross-sectional view of the liquid ejection head 101, the groove 411 overlaps with the fixed portion 421 in the height direction (Z direction) of the liquid ejection head 101. With this configuration, excess adhesive 410 is accommodated inside the groove 411. That is, it is possible to prevent the adhesive 410 from adhering to the non-fixed portion 422.

[0044] The inventors applied adhesive 410 assuming the maximum amount to be applied (width 1.2 mm, height 0.3 mm) in the process of attaching cover member 208. Then, they confirmed that when cover member 208 having a notch (depth 0.3 mm, width 1.2 mm) was attached to support member 207, adhesive 410 did not spill out onto non-fixed portion 422.

[0045] It is preferable that the depth of the notch (length in the Y direction) is 2.0 mm or more, and the height of the notch (length in the Z direction) is 0.3 mm or more and 0.5 mm or less. With this configuration, even if too much adhesive 410 is applied for some reason, the adhesive 410 is contained within the space 412. In other words, it is possible to prevent the adhesive 410 from adhering to the non-fixed portion 422. The adhesive 410 includes, for example, a thermosetting material. The adhesive 410 is fixed by being heated and cured at a predetermined temperature.

[0046] In this embodiment, an epoxy resin material that is relatively hard after curing is used as the adhesive 410. The Shore D hardness of the epoxy resin material is 60 Hs or more. The epoxy resin material is cured by heating at 120°C for 3 minutes or more. This configuration is particularly effective when the hardness after curing is high.

[0047] Furthermore, groove 411 was formed near starting point 423, and it was confirmed that adhesive 410 did not spill out into non-fixed portion 422 when flexible wiring board 206 was attached to support member 207. In this embodiment, the depth (length in the Z direction) of groove 411 was 0.3 mm, and the width (length in the Y direction) of groove 411 was 0.8 mm. However, the size of groove 411 is not limited to this size.

[0048] FIG. 5 is a schematic cross-sectional view of a flexible wiring board 206 that can be applied to this embodiment.

[0049] 5, the flexible wiring board 206 has a multi-layer structure, which includes a base film layer 501 containing polyimide, a copper foil 502, and a cover film layer 503 containing Mictron.

[0050] A first adhesive layer 504 is present between the base film layer 501 and the copper foil 502. The first adhesive layer 504 bonds the base film layer 501 and the copper foil 502 to each other. A second adhesive layer 505 is present between the copper foil 502 and the cover film layer 503. The second adhesive layer 505 bonds the copper foil 502 and the cover film layer 503 to each other.

[0051] In flexible wiring board 206, the thickness (length in the Z direction) of base film layer 501 at the portion bonded to second support surface 414 (see FIG. 4) is, for example, about 50.0 μm. In flexible wiring board 206, the thickness (length in the Z direction) of copper foil 502 at the portion bonded to second support surface 414 is, for example, about 35.0 μm. In flexible wiring board 206, the thickness (length in the Z direction) of cover film layer 503 at the portion bonded to second support surface 414 is, for example, about 4.4 μm.

[0052] The flexible wiring board 206 may have a structure in which the above-mentioned configuration is double-layered.

[0053] <Method of Manufacturing Liquid Ejection Head 101> Fig. 6 is a flowchart showing the manufacturing process of the liquid ejection head 101 in this embodiment. Figs. 7(a) to 7(f) are diagrams for explaining the state of each process. Each process (step) in Fig. 6 will be explained in order below with reference to Figs. 7(a) to 7(f). In the following explanation, the symbol "S" means a step.

[0054] As a prerequisite for carrying out the following manufacturing steps, the connection between the flexible wiring substrate 206 and the contact wiring substrate 211 has been completed. The process of adhering the flexible wiring substrate 206 and the element substrate 205 to the support member 207 has also been completed. The application of a sealant to the electrical connection portions has also been completed. Furthermore, the applied adhesive and sealant have also been thermally cured.

[0055] In the following description, for the sake of convenience, the liquid ejection head 101 in a state in which the contact wiring substrate 211 and the flow path member 201 have not yet been fixed together will be referred to as the "head unit 700 (see FIGS. 7(a) to (d))."

[0056] In S601, as shown in FIG. 7(a), the head unit 700 is fixed onto the clamp mechanism 702 of the backup unit 701.

[0057] 7(b), the backup mechanism 704 of the support unit 703 is brought into contact with the head unit 700. The position of the head unit 700 is determined by the backup unit 701 and the backup mechanism 704.

[0058] In S603, as shown in FIG. 7(c), the pressing mechanism 705 of the backup unit 701 is lowered to fix the head unit 700 from above.

[0059] In S604, as shown in FIG. 7(d), with the head unit 700 fixed from above, the roller 707 of the bending unit 706 is brought into contact with the flexible wiring board 206 to bend the flexible wiring board 206.

[0060] 7(e), a bending block 708 is pressed against the flexible wiring substrate 206, thereby bending the flexible wiring substrate 206 to a substantially right angle. By bending the flexible wiring substrate 206 at a substantially right angle, each of the multiple pins 201a of the flow path member 201 is inserted relatively to each of the multiple elongated holes of the contact wiring substrate 211. At this time, a positioning member 709 comes into contact with the contact wiring substrate 211, and the position of the contact wiring substrate 211 is determined.

[0061] In this embodiment, step S605 is performed before the step (S606) of crimping contact wiring substrate 211. This allows flexible wiring substrate 206 to be fixed in a state where the reaction force acting on the bent portion of flexible wiring substrate 206 is suppressed, while restricting the up and down movement of flexible wiring substrate 206 within the range of the elongated hole.

[0062] In S606, as shown in FIG. 7(f), the contact wiring substrate 211 is crimped to the flow path member 201. There may be two or more crimping positions. In this embodiment, a total of four pins 201a protrude from the flow path member 201, two at the top and two at the bottom. These four pins 201a are inserted into four elongated holes formed in the contact wiring substrate 211, respectively. With the pins 201a fitted into the elongated holes, the pins 201a are crimped by a crimping horn 710. By crimping in this manner, the contact wiring substrate 211 is fixed to the flow path member 201.

[0063] Of the two pins 201a present at the top and two at the bottom, the two pins 201a present at the top may be crimped before the two pins 201a present at the bottom, or the two pins 201a present at the bottom may be crimped before the two pins 201a present at the top.

[0064] In S607, the crimping horn 710 is released from the pin 201a.

[0065] In S608, the bending unit 706 is detached from the flexible wiring board 206.

[0066] In S609, the holding mechanism 705 is released from the head unit 700.

[0067] In S610, the head unit 700 is removed from the clamp mechanism 702. This releases the head unit 700 from being fixed by the backup unit 701.

[0068] After the above steps, the flexible wiring board 206 is bent so as not to be damaged, and the contact wiring board 211 is crimped to the flow path member 201 .

[0069] [Reference example] In the following, to facilitate understanding of the effect of the non-fixed portion 422 (see FIG. 4) of this embodiment, a reference example will be shown and described. Various components (for example, a paper feed roller (not shown)) are provided inside the liquid ejection device.

[0070] If the flexible wiring board 206 (see FIG. 2, etc.) is not bent at a substantially right angle, there is a risk that the flexible wiring board 206 may come into contact with these components. In order to prevent this contact, it is important to bend the flexible wiring board 206 without causing any lifting.

[0071] Fig. 8(a) is a schematic cross-sectional view of a head unit 800 in a reference example. In Fig. 8(a), the same configurations as in this embodiment will be given the same names as in this embodiment, and explanations will be omitted, and the configurations different from this embodiment will be mainly described.

[0072] 8(a), the flexible wiring board 206 of the head unit 800 does not have a non-fixed portion 422 (see FIG. 4) that is not fixed to the support member 207 on the upper surface of the support member 207. If the flexible wiring board 206 is sandwiched between the support member 207 and the cover member 208 and adhesive 410 is applied without providing the non-fixed portion 422, the adhesive 410 may protrude outside the support member 207.

[0073] FIG. 8(b) is a schematic cross-sectional view showing a reference example of the head unit 800 in a state where the flexible wiring board 206 is bent with the adhesive 410 protruding.

[0074] As shown in Figure 8(b), if the flexible wiring board 206 is bent at an acute angle starting from the protruding adhesive 410, excessive tensile stress may act on the surface of the flexible wiring board 206, which may cause damage to the flexible wiring board 206.

[0075] FIG. 8(c) is a diagram showing an example of damage that has occurred in the flexible wiring board 206.

[0076] 8(c), when flexible wiring board 206 is bent while being subjected to excessive tensile stress, cracks 801 may occur on the surface of flexible wiring board 206. When cracks 801 occur in flexible wiring board 206, electrical defects (such as short circuits) may occur.

[0077] As described above, in this embodiment, when supporting member 207 and cover member 208 are bonded together with flexible wiring board 206 sandwiched therebetween, non-fixed portion 422 is provided to which adhesive 410 is not applied. When flexible wiring board 206 is to be folded, flexible wiring board 206 can be folded using a predetermined position inside non-fixed portion 422 as folding starting point 423. With this configuration, flexible wiring board 206 is not bent at an acute angle using protruding adhesive 410 as the folding starting point.

[0078] Therefore, according to the liquid ejection head of the present disclosure, the reliability of the flexible wiring board can be improved.

[0079] Furthermore, a groove 411 and a space 412 are formed in the fixed portion 421, which is located closer to the element substrate 205 than the non-fixed portion 422. With this configuration, excess adhesive 410 can escape into the groove 411, the space 412, or both.

[0080] By forming the groove 411 and the space 412 in this way, it is possible to increase the margin for the amount of adhesive to be applied compared to when the groove 411 and the space 412 are not formed.

[0081] [Variations] FIG. 9(a) is a diagram showing a first modified example of this embodiment.

[0082] As shown in FIG. 9(a), the space 412 may be formed by a notch having an R shape.

[0083] FIG. 9(b) is a diagram showing a second modified example of this embodiment.

[0084] 9(b), the space 412 may be formed by a tapered notch. The taper is formed so as to gradually separate from the flexible wiring board 206 from the fixed portion 421 toward the non-fixed portion 422.

[0085] 9(a) and 9(b) gradually expands from the inside to the outside of the cover member 208, so that the air above the adhesive 410 that has spilled into the space 412 is not blocked but is open to the outside air. This configuration makes it easier to ensure a storage area for the adhesive 410 in the fixing portion 421.

[0086] FIG. 9(c) is a diagram showing a third modified example of this embodiment.

[0087] As shown in FIG. 9( c ), the space 412 may be a groove formed in the cover member 208 .

[0088] In this modified example, in the height direction of the liquid ejection head 101, a concave groove that is spaced apart from the flexible wiring board 206 is formed in the part of the cover member 208 that overlaps with the fixed portion 421 when the liquid ejection head 101 is viewed in cross section.

[0089] FIG. 9(d) is a diagram showing a fourth modified example of this embodiment.

[0090] 9(d), the space 412 may be a tapered groove formed in the cover member 208. In this modification, in the height direction of the liquid ejection head 101, a tapered groove having a taper that gradually moves away from the flexible wiring board 206 is formed in the portion of the cover member 208 that overlaps with the fixing portion 421 when the liquid ejection head 101 is viewed in cross section.

[0091] 9(c) and 9(d), it is possible to ensure a sufficient thickness at the end of the cover member 208. Therefore, when a cap member (not shown) caps the cover member 208, the rigidity of the cover member 208 is advantageous.

[0092] In any of the cases of Figures 9(a) to (d), it is preferable that the volume of the space 412 is secured so that excess adhesive 410 can be accommodated to prevent the adhesive 410 from entering the non-fixed portion 422.

[0093] [Second embodiment] A second embodiment of the technology of the present disclosure will be described below with reference to the drawings. In the following description, the same names and symbols are used for configurations that are similar to or correspond to those of the first embodiment, and descriptions thereof will be omitted, and differences will be mainly described.

[0094] In the flexible wiring board 206 of the first embodiment, the side on which the contact wiring board 211 is attached is bent. However, the flexible wiring board 206 may be bent along a surface of the flow path member 201 facing in the opposite direction to the surface on which the contact wiring board 211 is attached.

[0095] The present embodiment aims to provide a technique that allows flexible wiring board 206 to be bent along the surface facing in the direction opposite to the surface to which contact wiring board 211 is attached without damaging it.

[0096] FIG. 10 is a schematic cross-sectional view of a liquid ejection head 101 that can be applied to this embodiment.

[0097] 10, the flexible wiring board 206 of this embodiment is also bent from the upper surface (surface facing the +Z direction) of the support member 207 along a surface facing in the opposite direction to the surface on which the contact wiring board 211 is attached. Hereinafter, the surface of the support member 207 facing in the opposite direction to the surface on which the contact wiring board 211 is attached will be referred to as the back surface.

[0098] In this embodiment, a notch is also formed on the rear surface side of the cover member as the space 412. In addition, a groove 411 is also formed on the upper surface (surface facing the +Z direction) of the support member 207, closer to the rear surface than the element substrate 205. This configuration can prevent the adhesive 410 from reaching the bending starting point 423 on the rear surface side of the flexible wiring substrate 206.

[0099] Even if too much adhesive 410 is applied to the upper surface of the support member 207, closer to the rear surface of the support member 207 than to the element substrate 205, the adhesive 410 is contained within the groove 411, the space 412, or both.

[0100] Therefore, even when flexible wiring board 206 is bent along the back surface from the upper surface of support member 207, flexible wiring board 206 will not be bent from protruding adhesive 410 as a starting point.

[0101] Fig. 11(a) is a schematic plan view of a liquid ejection head 101 that can be applied to this embodiment. Fig. 11(a) is a view of the liquid ejection head 101 shown in Fig. 10, viewed from the +Z direction toward the -Z direction in Fig. 10. For ease of explanation, the cover member 208 (see Fig. 10) has been removed in Fig. 11(a).

[0102] 11(a), in a plan view of the bottom surface of the support member 207 (the surface facing the viewer in FIG. 11(a)), three grooves 411 are formed along the X direction at the end of the bottom surface of the support member 207 on the -Y direction side. One groove 411 is formed along the X direction at the end of the bottom surface of the support member 207 on the +Y direction side.

[0103] The flexible wiring substrate 206 has a through-hole 206a formed therein, which penetrates the flexible wiring substrate 206 in the Z direction while the flexible wiring substrate 206 is adhered to the support member 207. This configuration does not impede the supply of liquid from the support member 207 to the element substrate 205. A portion of the through-hole 206a overlaps with a portion of the flexible wiring substrate 206 that is bent. In other words, when the flexible wiring substrate 206 is bent, the through-hole 206a also bends.

[0104] FIG. 11(b) is a schematic diagram showing a step of applying an adhesive 410 that can be applied to this embodiment.

[0105] As shown in FIG. 11(b), in this embodiment, adhesive 410 is discharged from a needle 1100 onto a coating surface (surface facing the +Z direction in FIG. 11(b)) of the liquid ejection head 101. The coating surface of the liquid ejection head 101 includes the upper surface of a support member 207 and a flexible wiring board 206 stacked on the upper surface of the support member 207. Therefore, the distance D1 from the needle 1100 to the coating surface of the liquid ejection head 101 changes depending on whether or not the flexible wiring board 206 is present. This raises concerns that the adhesive 410 may spill out, particularly in areas where the flexible wiring board 206 is present.

[0106] 11(c) is a bottom view of the cover member 208 and flexible wiring board 206 that can be applied to this embodiment. For convenience of explanation, the cover member 208 is shown as a bottom perspective view. As described above, there is a concern that the adhesive 410 may protrude from the area where the flexible wiring board 206 is present.

[0107] 11(c), a space 412 for suppressing the overflow of the adhesive 410 is formed in the cover member 208 at the portion where the cover member 208 and the flexible wiring board 206 overlap. For example, it is preferable to form a notch as the space 412 that can cover the entire width (length in the X direction) of the flexible wiring board 206.

[0108] As described above, according to the technique of this embodiment, the flexible wiring board 206 can be bent along the surface facing in the direction opposite to the surface to which the contact wiring board 211 is attached without being damaged.

[0109] [Modification of the second embodiment] Fig. 12(a) is a schematic plan view of a liquid ejection head 101 that can be applied to this embodiment. Fig. 12(a) is a view of the liquid ejection head 101 shown in Fig. 10, viewed from the +Z direction toward the -Z direction in Fig. 10. For ease of explanation, the cover member 208 (see Fig. 10) has been removed in Fig. 12(a).

[0110] 12(a), in a plan view of the bottom surface of the support member 207 (the surface facing the viewer in FIG. 12(a)), one groove 411 is formed along the X direction at the end of the bottom surface of the support member 207 on the -Y direction side. One groove 411 is formed along the X direction at the end of the bottom surface of the support member 207 on the +Y direction side.

[0111] Flexible wiring board 206 has through-hole 206a formed therein, which penetrates flexible wiring board 206 in the Z direction while flexible wiring board 206 is adhered to support member 207. A portion of through-hole 206a overlaps with a portion of flexible wiring board 206 that is bent. That is, when flexible wiring board 206 is bent, through-hole 206a is also bent.

[0112] In addition, in both FIG. 12(a) and FIG. 11(a), the configuration of the groove 411 formed on the +Y direction side of the bottom surface of the support member 207 is the same.

[0113] Fig. 12(b) is a schematic diagram of a process for applying adhesive 410 that can be applied to this embodiment. Note that Fig. 12(b) will be described assuming that adhesive 410 is applied to a portion of flexible wiring substrate 206 that cannot be bent.

[0114] As shown in FIG. 12(b), when adhesive 410 is applied to the portion of flexible wiring board 206 that cannot be bent, distance D2 from needle 1100 to flexible wiring board 206 remains unchanged.

[0115] 12(c) is a bottom view of the cover member 208 and flexible wiring board 206 that can be applied to this embodiment. For convenience of explanation, the cover member 208 is shown as a bottom perspective view.

[0116] As described above, in this modification, the distance D2 from the needle 1100 to the flexible wiring substrate 206 remains unchanged. Therefore, in this modification, the space 412 may be formed so as to cover the entire width (length in the X direction) of the flexible wiring substrate 206, as shown in Fig. 12(c). In this modification, the groove 411 and space 412 formed on the -Y direction side are larger than the groove 411 and space 412 formed on the -Y direction side in Figs. 11(a) and 11(b).

[0117] Therefore, the groove 411 and the space 412 of this modified example can accommodate more adhesive 410 than the groove 411 and the space 412 shown in Figures 11(a) and 11(b). In other words, the margin for the amount of adhesive 410 to be applied can be increased.

[0118] [Third embodiment] Hereinafter, a third embodiment of the technology of the present disclosure will be described with reference to the drawings. In the following description, the same names and symbols are used for configurations that are similar to or correspond to those of the first and second embodiments, and descriptions thereof will be omitted, and differences will be mainly described.

[0119] In the liquid ejection head 101 of the first and second embodiments, a cover member 208 and a contact wiring substrate 211 are attached. However, the cover member 208 and the contact wiring substrate 211 are not essential components of the liquid ejection head. According to this embodiment, even in a liquid ejection head that does not have the cover member 208 or the contact wiring substrate 211, the reliability of the flexible wiring substrate can be improved.

[0120] Fig. 13(a) is a schematic cross-sectional view of a liquid ejection head 101 that can be applied to this embodiment. The liquid ejection head 101 shown in Fig. 13(a) is in a state before the flexible wiring substrate 206 is bent.

[0121] 13(a), the liquid ejection head 101 of this embodiment includes a housing 1300 in which a flow path member 201 and a support member 207 are integrally formed. An element substrate 205 and a flexible wiring substrate 206 are bonded to the upper surface of the housing 1300 with an adhesive 410. Grooves 411 are formed on the upper surface of the housing 1300 at both the end on the −Y direction side and the end on the +Y direction side. Any adhesive 410 that overflows when the element substrate 205 is bonded is contained within the grooves 411.

[0122] Fig. 13(b) is a schematic cross-sectional view of a liquid ejection head 101 that can be applied to this embodiment. In the liquid ejection head 101 shown in Fig. 13(b), the flexible wiring board 206 is crimped to the housing 1300.

[0123] 13(b), the flexible wiring board 206 of this embodiment is directly crimped to the housing 1300. The housing 1300 has a pin 201a. With the flexible wiring board 206 bent at a substantially right angle, the pin 201a is relatively inserted into an opening formed in the flexible wiring board 206 and crimped.

[0124] In this embodiment as well, flexible wiring board 206 has fixed portion 421 to which adhesive 410 is applied and non-fixed portion 422 to which adhesive 410 is not applied. Bending starting point 423 of flexible wiring board 206 is located inside non-fixed portion 422.

[0125] Therefore, the flexible wiring board 206 will not be bent starting from the protruding adhesive 410. This type of liquid ejection head also improves the reliability of the flexible wiring board.

[0126] [Other embodiments] The above describes examples to which the technology of the present disclosure can be applied. However, the above description does not limit the technical scope of the present disclosure. As an example, in this embodiment, a thermal method is used in which a recording element (heater) generates bubbles to eject liquid. However, the technology of the present disclosure can also be applied to liquid ejection heads that employ a piezo method in which a piezoelectric element is used as a recording element for ejecting liquid, or various other liquid ejection methods.

[0127] The liquid ejection head and liquid ejection device equipped with the liquid ejection head of the present disclosure can be applied to devices such as copiers, facsimiles with communication systems, and word processors with printer units. In addition, the liquid ejection head and liquid ejection device equipped with the liquid ejection head of the present disclosure can be applied to full-line inkjet printers equipped with a liquid ejection head whose width is wider than the width of a recording medium. Furthermore, the liquid ejection head and liquid ejection device equipped with the liquid ejection head can be applied to industrial recording devices combined with various processing devices. For example, the liquid ejection head can be used in applications such as biochip production, electronic circuit printing, and semiconductor substrate production.

[0128] In the above-described embodiment, the liquid ejection device is configured to circulate the liquid between the tank and the liquid ejection head, but other configurations are also possible. For example, the liquid may be circulated between the tank and the liquid ejection head. Alternatively, instead of circulating the liquid, two tanks may be provided upstream and downstream of the liquid ejection head, and the liquid may flow from one tank to the other to cause the liquid to flow within the pressure chamber.

[0129] The present disclosure includes the following configurations and methods.

[0130] [Configuration 1] an element substrate that ejects liquid in response to an electrical signal; a support member for supporting the element substrate; a flexible wiring board fixed to the support member for supplying electrical signals to the element substrate; A liquid ejection head comprising: On a surface where the support member supports the element substrate, the flexible wiring board includes a fixed portion fixed to the support member with an adhesive and a non-fixed portion not fixed to the support member, the flexible wiring board is bent starting from a position included in the non-fixed portion; A liquid ejection head characterized by:

[0131] [Configuration 2] a cover member that covers the flexible wiring board and has an opening that exposes the element substrate is adhered to the flexible wiring board; The liquid ejection head according to configuration 1.

[0132] [Configuration 3] The cover member has a space formed at the boundary between the fixed portion and the non-fixed portion, the space being capable of accommodating an adhesive. 3. The liquid ejection head according to configuration 2.

[0133] [Configuration 4] the space is located between the starting point and the element substrate in a direction parallel to the surface; 4. The liquid ejection head according to configuration 3.

[0134] [Configuration 5] The space is formed by a notch formed in the cover member. 5. The liquid ejection head according to configuration 3 or 4.

[0135] [Configuration 6] The notch has an R shape. 6. The liquid ejection head according to configuration 5.

[0136] [Configuration 7] The notch has a taper that gradually moves away from the flexible wiring board from the fixed portion toward the non-fixed portion. 7. The liquid ejection head according to configuration 5 or 6.

[0137] [Configuration 8] The space is formed by a groove formed in the cover member. 8. The liquid ejection head according to any one of configurations 3 to 7.

[0138] [Configuration 9] the groove is a tapered groove inclined with respect to the flexible wiring board; A liquid ejection head according to configuration 8.

[0139] [Configuration 10] a groove capable of accommodating an adhesive is formed in the support member between the starting point and the element substrate in a direction parallel to the surface; 10. The liquid ejection head according to any one of the first to ninth aspects.

[0140] [Configuration 11] a contact wiring board electrically connected to the flexible wiring board; a housing having a first surface on which the contact wiring board is mounted and a second surface facing in the opposite direction to the first surface; Further provided with the fixing portion includes a first fixing portion and a second fixing portion different from the first fixing portion, the non-fixed portion includes a first non-fixed portion and a second non-fixed portion different from the first non-fixed portion, the first fixed portion and the first non-fixed portion are provided closer to the first surface than the element substrate, the second fixed portion and the second non-fixed portion are provided closer to the second surface than the element substrate; 11. The liquid ejection head according to any one of the first to tenth aspects.

[0141] [Configuration 12] a flow path member having a flow path for supplying a liquid to the element substrate; The support member has a first support surface that supports the flow path member and a second support surface that supports the flexible wiring board and the element substrate. 12. The liquid ejection head according to any one of the first to eleventh aspects.

[0142] [Method 13] A method for manufacturing a liquid ejection head that ejects liquid, comprising: a bonding step of bonding a flexible wiring board having flexibility and an element substrate that ejects liquid to a support member; a bending step of bending a portion of the flexible wiring board that is not bonded to the support member; Including, In the bonding step, the flexible wiring board is bonded to the support member so that the support member has a fixed portion that is fixed to the support member and a non-fixed portion that is not fixed to the support member on a surface where the support member supports the element substrate; In the bending step, the flexible wiring board is bent starting from a position included in the non-fixed portion. A method for manufacturing a liquid ejection head, comprising:

[0143] [Method 14] The method further includes a coating step of coating the support member with an adhesive before the bonding step so that the non-fixed portion and the fixed portion are formed. Method 14. A method for manufacturing a liquid ejection head according to method 13.

[0144] [Method 15] In the bonding step, the fixing portion includes a first fixing portion and a second fixing portion different from the first fixing portion, the non-fixed portion includes a first non-fixed portion and a second non-fixed portion different from the first non-fixed portion, the first fixed portion and the first non-fixed portion are provided on one side of the element substrate, the second fixed portion and the second non-fixed portion are provided on the other side of the element substrate; 15. A method for manufacturing a liquid ejection head according to Method 13 or 14.

[0145] [Method 16] Prior to the bending step, a cover member that covers the flexible wiring board and has an opening through which the element substrate is exposed is adhered to the flexible wiring board; 16. A method for manufacturing a liquid ejection head according to any one of Methods 13 to 15.

[0146] [Method 17] The method further includes a connecting step of connecting a contact wiring board having electrical contacts to the flexible wiring board. 17. A method for manufacturing a liquid ejection head according to any one of Methods 13 to 16.

[0147] [Method 18] The bending step is performed before the connecting step. A method for manufacturing a liquid ejection head according to Method 17.

Claims

1. an element substrate that ejects liquid in response to an electrical signal; a support member for supporting the element substrate; a flexible wiring board fixed to the support member for supplying electrical signals to the element substrate; A liquid ejection head comprising: On a surface where the support member supports the element substrate, the flexible wiring board includes a fixed portion fixed to the support member with an adhesive and a non-fixed portion not fixed to the support member, the flexible wiring board is bent starting from a position included in the non-fixed portion; A liquid ejection head characterized by:

2. a cover member that covers the flexible wiring board and has an opening that exposes the element substrate is adhered to the flexible wiring board; The liquid ejection head according to claim 1 .

3. The cover member has a space formed at the boundary between the fixed portion and the non-fixed portion, the space being capable of accommodating an adhesive. The liquid ejection head according to claim 2 .

4. the space is located between the starting point and the element substrate in a direction parallel to the surface; The liquid ejection head according to claim 3 .

5. The space is formed by a notch formed in the cover member. The liquid ejection head according to claim 3 .

6. The notch has an R shape. The liquid ejection head according to claim 5 .

7. The notch has a taper that gradually moves away from the flexible wiring board from the fixed portion toward the non-fixed portion. The liquid ejection head according to claim 5 .

8. The space is formed by a groove formed in the cover member. The liquid ejection head according to claim 3 .

9. the groove is a tapered groove inclined with respect to the flexible wiring board; The liquid ejection head according to claim 8 .

10. a groove capable of accommodating an adhesive is formed in the support member between the starting point and the element substrate in a direction parallel to the surface; The liquid ejection head according to claim 1 .

11. a contact wiring board electrically connected to the flexible wiring board; a housing having a first surface on which the contact wiring board is mounted and a second surface facing in a direction opposite to the first surface; Further provided with the fixing portion includes a first fixing portion and a second fixing portion different from the first fixing portion, the non-fixed portion includes a first non-fixed portion and a second non-fixed portion different from the first non-fixed portion, the first fixed portion and the first non-fixed portion are provided closer to the first surface than the element substrate, the second fixed portion and the second non-fixed portion are provided closer to the second surface than the element substrate; The liquid ejection head according to claim 1 .

12. a flow path member having a flow path for supplying a liquid to the element substrate; the support member has a first support surface that supports the flow path member and a second support surface that supports the flexible wiring board and the element substrate. The liquid ejection head according to claim 1 .

13. A method for manufacturing a liquid ejection head that ejects liquid, comprising: a bonding step of bonding a flexible wiring board having flexibility and an element substrate that ejects liquid to a support member; a bending step of bending a portion of the flexible wiring board that is not bonded to the support member; Including, In the bonding step, the flexible wiring board is bonded to the support member so that the support member has a fixed portion that is fixed to the support member and a non-fixed portion that is not fixed to the support member on a surface where the support member supports the element substrate; In the bending step, the flexible wiring board is bent starting from a position included in the non-fixed portion. A method for manufacturing a liquid ejection head, comprising:

14. The method further includes a coating step of coating the support member with an adhesive before the bonding step so that the non-fixed portion and the fixed portion are formed. The method for manufacturing a liquid ejection head according to claim 13.

15. In the bonding step, the fixing portion includes a first fixing portion and a second fixing portion different from the first fixing portion, the non-fixed portion includes a first non-fixed portion and a second non-fixed portion different from the first non-fixed portion, the first fixed portion and the first non-fixed portion are provided on one side of the element substrate, the second fixed portion and the second non-fixed portion are provided on the other side of the element substrate; The method for manufacturing a liquid ejection head according to claim 13.

16. Prior to the bending step, a cover member that covers the flexible wiring board and has an opening through which the element substrate is exposed is adhered to the flexible wiring board; The method for manufacturing a liquid ejection head according to claim 13.

17. The method further includes a connecting step of connecting a contact wiring board having electrical contacts to the flexible wiring board. The method for manufacturing a liquid ejection head according to claim 13.

18. The bending step is performed before the connecting step. The method for manufacturing a liquid ejection head according to claim 17.

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