Liquid discharge recording element unit and method for manufacturing the same

Abstract

To suppress blockage of an ink channel due to protrusion of an adhesive without increasing a chip area.SOLUTION: In a liquid discharge recording element unit including: a first substrate which has a first partition wall that partitions a first channel including a plurality of discharge ports for discharging liquid for image recording and an energy generation unit which generates energy for discharging the liquid from the first channel via the discharge ports; and a second substrate which includes a second partition wall that partitions a second channel including a supply port for supplying the liquid and which is laminated on the first substrate by being bonded to each other with an adhesive such that the second channel communicates with the first channel, the first partition wall and the second partition wall are continuous while having a gap of a prescribed facing interval without the adhesive interposed therebetween in the lamination direction of the first substrate and the second substrate, and the hydraulic diameter of the gap is smaller than the hydraulic diameter of the minimum channel part having the minimum channel cross-sectional area in the first channel.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a liquid ejection recording element unit and a method for manufacturing the same.

Background Art

[0002] An inkjet printer is an output device that forms characters and images by ejecting minute droplets of ink as a recording liquid from an inkjet recording head as a liquid ejection recording head. In recent years, it has been used as a home or office device, and has further spread to industrial applications. This inkjet recording head is formed by accurately adhering a recording element unit to a support member connected to an ink supply means. Further, this recording element unit is formed by electrically mounting a recording element substrate having a plurality of ejection energy generation portions, an ink flow path, and an ink ejection port formed on a silicon substrate, an ejection signal output portion such as a drive IC, and a wiring substrate for transmitting an electrical signal from a printer main body. Among these, as a method for forming the ink flow path of the recording element unit, there is a method of bonding a plurality of substrates. Patent Document 1 describes a technique for preventing loss of ink ejection driving power due to protruding adhesive by providing a recess where ink does not pass on a bonding surface in ink flow path formation by adhesion. Further, Patent Document 2 proposes a technique for forming a flow path by filling an adhesive into a recess formed on a bonding surface and then bonding the substrates in order to improve workability and yield.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, inkjet recording heads have seen progress in shrinking the recording element substrate to further reduce product costs and miniaturizing components to improve functionality. To meet these product demands, the ink channels within the recording element unit require further miniaturization and narrower pitch. However, when attempting to form ink channels by bonding multiple substrates with uneven surfaces, the bonding area becomes narrow. Furthermore, the ink channels themselves become narrower, making them more susceptible to blockage due to adhesive overflow. Simply applying the technologies described in Patent Documents 1 and 2 would result in the formation of recesses that do not function as ink channels, raising concerns that this would lead to an increase in chip area.

[0005] The objective of the present invention is to provide a technology that can suppress blockage of the ink flow path due to adhesive overflow without increasing the chip area. [Means for solving the problem]

[0006] To achieve the above objective, the liquid ejection recording element unit of the present invention is: A first substrate comprising: a first partition wall that demarcates a first flow path including a plurality of discharge ports for discharging liquid for image recording; and an energy generating unit that generates energy to discharge the liquid from the first flow path through the discharge ports; A second substrate is laminated and bonded to the first substrate with an adhesive such that the second flow path is in communication with the first flow path, comprising a second partition wall that demarcates a second flow path including a supply port for supplying liquid, In a liquid discharge recording element unit equipped with, The first partition wall and the second partition wall are located in the stacking direction of the first substrate and the second substrate. They are connected with a predetermined gap between them without the use of adhesive, The hydraulic diameter of the gap is smaller than the hydraulic diameter of the smallest flow path section having the smallest flow path cross-sectional area in the first flow path. To achieve the above objective, the method for manufacturing the liquid ejection recording element unit of the present invention is as follows: A first substrate comprising: a first partition wall that demarcates a first flow path including a plurality of discharge ports for discharging liquid for image recording; and an energy generating unit that generates energy to discharge the liquid from the first flow path through the discharge ports; A second substrate is laminated and bonded to the first substrate with an adhesive such that the second flow path is in communication with the first flow path, comprising a second partition wall that demarcates a second flow path including a supply port for supplying liquid, A method for manufacturing a liquid discharge recording element unit comprising: A substrate manufacturing process for manufacturing the first substrate and the second substrate, A lamination step of bonding the first substrate and the second substrate together with an adhesive and stacking them, In a method for manufacturing a liquid ejection recording element unit including, In the lamination process, no adhesive is applied to the gap between the first partition wall and the second partition wall that are connected in the lamination direction of the first substrate and the second substrate, and the first substrate and the second substrate are laminated such that the hydraulic diameter of the gap is smaller than the hydraulic diameter of the smallest channel section having the smallest channel cross-sectional area in the first channel. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress blockage of the ink flow path due to adhesive overflow without increasing the chip area. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a schematic perspective view of a liquid ejection recording element unit according to an embodiment of the present invention. [Figure 1B] This is a schematic perspective view showing the manufacturing process of a liquid ejection recording element unit. [Figure 1C] This is a schematic perspective view showing the manufacturing process of a liquid ejection recording element unit. [Figure 1D] This is a schematic perspective view showing the manufacturing process of a liquid ejection recording element unit. [Figure 2] This is a schematic diagram showing the configuration of the ink flow channel substrate. [Figure 3] It is a schematic diagram showing the ink flow path configuration of Example 1 of the present invention. [Figure 4] It is a schematic diagram showing the configuration of the ink flow path member. [Figure 5] It is a schematic diagram of the ink flow path configuration by the ink flow path substrate and the ink flow path member. [Figure 6] It is a schematic diagram showing the ink flow path configuration of Example 2 of the present invention. [Figure 7] It is a schematic diagram showing the ink flow path configuration of Example 3 of the present invention. [Figure 8] It is a schematic diagram showing the ink flow path configuration of Example 4 of the present invention. [Figure 9] It is a diagram for explaining the hydraulic diameter in the ink flow path of Example 1 of the present invention.

Mode for Carrying Out the Invention

[0009] Hereinafter, with reference to the drawings, the mode for carrying out this invention will be exemplarily and specifically described based on examples. Note that the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. Also, not all combinations of the features described in this embodiment are essential for the solution means of the present invention. The components described in the embodiment are merely examples, and are not intended to limit the scope of this invention only to them.

[0010] Referring to FIGS. 1A to 1D, the outline of the configuration of the liquid ejection recording unit according to the embodiment of the present invention will be described together with its manufacturing process (manufacturing method). FIG. 1A is a schematic diagram showing the liquid ejection recording element unit according to the embodiment of the present invention. FIGS. 1(b), (c), and (d) are schematic diagrams showing the manufacturing process of the liquid ejection recording element unit.

[0011] The liquid ejection recording element unit 1 (hereinafter referred to as the recording element unit 1) according to an embodiment of the present invention shown in FIG. 1A is used for a liquid ejection head in a liquid ejection device provided in a liquid ejection type recording device typified by an inkjet printer. In an inkjet printer, the liquid ejection head is configured as an inkjet recording head used to record a desired image on a recording material by ejecting ink as an image recording liquid onto the recording material. The recording device is also provided with an ink tank as a liquid storage unit for storing the liquid supplied to the liquid ejection head, a conveyance mechanism for a recording material such as a sheet which is an object to be recorded, and the like.

[0012] The ink supplied from an ink tank (not shown) passes through the ink flow path partitioned in the ink flow path member 80, the ink flow path substrate 30, and the recording element substrate 10 from an opening 81 as an ink supply port, and is ejected from an ink ejection port 14 (see FIG. 3 etc.). The ink receives the energy generated by a discharge energy generation unit 17 (see FIG. 3 etc.) provided in the ink flow path and protrudes from the ink ejection port 14. The ink ejected from the ejection port 14 adheres to the image recording surface of the recording material arranged to face the ejection port 14, and an image is formed (recorded) on the recording material.

[0013] FIG. 1B is a schematic perspective view showing the manufacturing process of the recording element unit 1, and shows a part of the configuration of the recording element unit 1 disassembled. That is, FIG. 1B shows a process in which the recording element substrate 10 as a first substrate (flow path forming member), the ink flow path substrate 30 as a second substrate (flow path forming member), the ejection port surface cover 40, and the electrical wiring member 50 are integrated. Before the integration shown in FIG. 1B, the flow path configurations and the like provided in the recording element substrate 10 and the ink flow path substrate 30 are respectively formed by etching the silicon substrate (substrate manufacturing process).

[0014] The recording element substrate 10 is manufactured by silicon etching technology and has an ink ejection port 14 (see Figure 3, etc.) on its back side. The recording element substrate 10 is formed by joining a wafer having an ejection energy generation section 17 (see Figure 3, etc.) and an electrode PAD 11 that conducts to it, and a wafer having an ink channel 12 that communicates with the ink ejection port 14 (see Figure 3, etc.), and then dicing it into individual pieces.

[0015] First, an ink channel substrate 30 for forming an ink channel for supplying ink to the recording element substrate 10 is laminated and bonded to the recording element substrate 10 (lamination process). The ink channel substrate 30 has channel openings formed on both the bonding surface (joint surface) with the recording element substrate 10 and the opposite surface, so as to communicate with the ink channel 12 formed in the recording element substrate 10.

[0016] The drive IC 20, which generates and outputs the electrical signal for ink ejection, is electrically mounted on an electrical wiring component 50 connected to the printer body. In this embodiment, a flexible wiring board with polyimide used for the base film and cover film is used as the electrical wiring component 50. Note that the electrical wiring component is not limited to a specific type and can be appropriately selected, including printed circuit boards and the like.

[0017] Next, the ejection port surface of the recording element substrate 10, where the ink ejection port 14 (see Figure 3, etc.) opens, is bonded to the ejection port surface cover 40, which is open to match the ink ejection port 14. Then, the electrical wiring member 50 on which the drive IC 20 is mounted is bonded. In this embodiment, alumina is used as the ejection port surface cover 40, but the material is not limited to this and can be changed to a metal member or the like as appropriate.

[0018] Figure 1C is a schematic perspective view showing the manufacturing process of the recording element unit 1, and shows a disassembled portion of the components of the recording element unit 1. Figure 1C shows the process of electrically connecting the recording element substrate 10 and the electrical wiring member 50, which were integrated in the process shown in Figure 1B. Specifically, the electrode pad 11 on the recording element substrate 10, which is bonded to the discharge port surface cover 40, and the electrode pad 21 on the drive IC 20, which is mounted on the electrical wiring member 50, are electrically connected by wire bonding 22.

[0019] Figure 1D is a schematic perspective view showing the manufacturing process of the recording element unit 1, and shows a disassembled view of a part of the components of the recording element unit 1. Figure 1D shows the process of protectively coating the wire bonding 22 formed in the process of Figure 1C, and further laminating and bonding the ink flow channel member 80 as a third flow channel forming member.

[0020] In other words, the electrically connected electrodes PAD11, 21 and bonding wire 22 are covered with a sealing material 62. Note that the electrical mounting means and configuration are not limited to this and can be modified as appropriate. For example, the electrical wiring members 50 and the drive IC 20 may be directly electrically connected to the discharge port cover 40 without adhesive bonding.

[0021] Then, the ink channel member 80 is bonded to the ink channel substrate 30. This forms the recording element unit 1 shown in Figure 1A. At this time, the ink channel member 80 has channel openings formed on both the bonding surface (joint surface) with the ink channel substrate 30 and the opposite surface, so as to communicate with the first opening 31 formed in the ink channel substrate 30. In this embodiment, alumina is used as the ink channel member 80. However, the material is not limited to this and can be changed to metal materials as appropriate.

[0022] (Example 1) The recording element unit 1 in Embodiment 1 of the present invention will be described using Figures 2(a) to 5(c).

[0023] Figure 2(a) is a schematic perspective view of the ink channel substrate 30 with the side opposite to the bonding surface (joint surface) with the recording element substrate 10 (the bonding surface with the ink channel member 80) facing upward. Figure 2(b) is a schematic perspective view of the ink channel substrate 30 with the bonding surface (joint surface) with the recording element substrate 10 facing upward. Figure 2(c) is a schematic plan view showing the planar configuration of the ink channel substrate 30 in this embodiment as seen from the side of the bonding surface with the recording element substrate 10. Figures 3(a), 3(b), and 3(c) are schematic diagrams showing the state in which the ink channel is formed by bonding the recording element substrate 10 and the ink channel substrate 30 in this embodiment.

[0024] In this embodiment, the ink flow path is formed by connecting a flow path (first flow path) partitioned in the recording element substrate 10 including an ink ejection port 14, and a flow path (second flow path) partitioned in the ink flow path substrate 30 including a first opening 31 as an ink supply port, through substrate bonding.

[0025] The ink flow channel substrate 30 has a second opening 32 on the bonding surface (joining surface) 30b (second surface) with respect to the recording element substrate 10, and a first opening 31 on the opposite surface 30a (first surface). The first opening 31 and the second opening 32 are in communication within the ink flow channel substrate 30.

[0026] Specifically, the first openings 31 are arranged in multiples on the surface 30a, spaced apart in both the longitudinal direction (first direction) and the transversely short direction (second direction) of the ink flow path substrate 30. In contrast, the second openings 32 have a groove shape extending in the longitudinal direction of the ink flow path substrate 30 on the adhesive surface 30b, and multiple first openings 31 are opened at the bottom of the groove at intervals in the same direction. That is, the second openings 32 are configured to connect the multiple first openings 31 arranged in the longitudinal direction of the ink flow path substrate 30. Multiple second openings 32 are provided so as to be spaced apart in the transverse direction of the ink flow path substrate 30 and arranged parallel to each other. Between two adjacent second openings 32, there is a first partition wall extending in the longitudinal direction. It is separated by a partition wall 37. Therefore, the multiple first openings 31 that open on the surface 30a opposite to the adhesive surface 30b are configured to communicate with the ink flow path 12 provided on the recording element substrate 10 via one of the multiple second openings 32 that open on the side of the adhesive surface 30b with the recording element substrate 10. In addition, the ink flow path substrate 30 has an annular adhesive region 33 formed on the outer periphery of the adhesive surface 30b, surrounding the multiple second openings 32 with the recording element substrate 10.

[0027] On the other hand, the recording element substrate 10 has an ink channel 12 with a groove shape extending in the longitudinal direction at the bonding surface (joining surface) with the ink channel substrate 30, and multiple minimum channel sections 19 are provided at the bottom of the groove. The minimum channel section 19 is the channel with the smallest channel cross-sectional area among the channels partitioned within the recording element substrate 10. The minimum channel section 19 is connected to an energy-giving channel section 14a, which is a channel space where the ejection energy generation section 17 and the ink ejection port 14 face each other and energy is applied to the ink ejected from the ink ejection port 14. Multiple ink channels 12 are arranged in parallel with spacing in the short direction, corresponding to the second opening 32 of the ink channel substrate 30. Two adjacent ink channels 12 are separated by a partition wall 15, which is a second partition wall extending in the longitudinal direction. Two ink channels 12 separated by one partition wall 15 are in communication with each other via the energy-giving channel section 14a.

[0028] Adhesive 60 is applied only to the outer periphery of the bonding surface between the recording element substrate 10 and the ink channel substrate 30, and the recording element substrate 10 and the ink channel substrate 30 are pressed together to crush the adhesive 60, thereby bonding them together. This creates an ink channel that communicates from the first opening 31 of the ink channel substrate 30 to the ink discharge port 14 of the recording element substrate 10. The spaces between two adjacent ink channels 12 in the short direction and between two second openings 32 are separated by partition walls 15 and 37 that are connected in the substrate stacking direction.

[0029] The ink flowing through the ink channel is ejected from the ink outlet 14 by the energy generated by the ejection energy generation unit 17 in the energy supply channel section 14a. The specific configuration of the ejection energy generation unit 17 is not limited to any particular type, but for example, it may be equipped with a piezoelectric element, and by changing the volume of the channel through the deformation of the piezoelectric element, it generates the pressure required to eject the ink. Alternatively, for example, it may be equipped with an electrothermal exchange element, and the ink may be ejected by heating the ink and generating bubbles.

[0030] This ink channel is a circulating ink channel in which ink flows from the first opening 31 of the ink channel substrate 30 toward the ejection energy generation section 17 of the recording element substrate 10 by an ink pressurizing means (not shown), and the ink that is not ejected returns to the first opening 31. That is, the two ink channels 12 separated by a partition wall 15 are in communication with each other via an energy-generating channel section 14a, and the two second openings 32 separated by a partition wall 37 connected to this partition wall 15 are also in communication with each other. Therefore, as shown in Figures 3(b) and 3(c), the two ink channels separated by partition walls 15 and 37, which are connected in the stacking direction of the recording element substrate 10 and the ink channel substrate 30, are capable of circulating ink flow via the energy-generating channel section 14a.

[0031] Figure 3(b) is a cross-sectional view AA of Figure 3(a), showing the path (arrow 70a) of the ink from the first opening 31 of the ink channel substrate 30 toward the vicinity of the ejection energy generation unit 17. Figure 3(c) is a cross-sectional view BB of Figure 3(a), showing the path (arrow 70b) of the un-ejected ink returning from the vicinity of the ejection energy generation unit 17 to the first opening 31 of the ink channel substrate 30. Note that ink circulation within this liquid channel is not an essential component of the present invention, and the present invention can be similarly applied to ink channel configurations that do not involve circulation.

[0032] In this embodiment, the thickness of the partition wall 15, which is the ink channel partition wall width 16, is 100 μm to 200 μm. When the partition wall 15 is bonded to the ink channel substrate 30 (partition wall 37) using adhesive, there is a concern that the ink channel may become blocked by excess adhesive. Therefore, in this embodiment, the bonding area on the bonding surface between the recording element substrate 10 and the ink channel substrate 30 is the area excluding the opposing areas between partition wall 15 and partition wall 37, specifically, the outer peripheral area of ​​the bonding surface. This makes it possible to suppress blockage of the ink channel due to excess adhesive without increasing the chip area. The recording element substrate 10 and the ink channel substrate 30, formed by silicon etching, have precisely finished bonding surfaces. Therefore, by compressing the adhesive applied only to the outer peripheral area of ​​the bonding surface as thinly as possible, the gap 61, which is the opposing distance in the stacking direction between partition wall 15 and ink channel substrate 30 (partition wall 37), can be minimized. The gap 61 between the partition wall 15 and the ink channel substrate 30 (partition wall 37) depends on the filler particle size, viscoelasticity, curing shrinkage, and other physical properties of the adhesive 60 used.

[0033] In this embodiment, the gap 61 between partition wall 15 and partition wall 37 is set as a predetermined opposing distance of 0 to 25 μm, i.e., 25 μm or less.

[0034] Here, assuming the use of the same type of ink, the fluid resistance within the ink channel is generally defined by equation (1), using the hydraulic diameter dh according to the channel width, the channel cross-sectional area A of that portion, and the wet edge length (perimeter of the cross-section) S. dh = 4A / S (1)

[0035] The scope of application of the present invention is such that the hydraulic diameter dh1 in the smallest flow path section 19 and the hydraulic diameter dh2 in the gap 61 between the partition wall 15 and the partition wall 37 satisfy the relationship given by equation (2). dh1>dh2 (2)

[0036] Figure 9 shows the hydraulic diameter dh1 in the smallest flow path section 19 and the hydraulic diameter dh2 in the gap 61 in the recording element unit 1 according to this embodiment. As shown in Figure 9, in this embodiment, the smallest flow path section 19 is a square with a width 19w of 60 μm × 60 μm. Also, the distance of the gap 61 between partition wall 15 and partition wall 37 in the depth direction (longitudinal direction of the ink flow path substrate 30) in Figures 3(b) and 3(c) is assumed to be 25 mm (= 25000 μm). That is, the gap 61 between partition wall 15 and partition wall 37 in the joint surface between the ink flow path substrate 30 and the recording element substrate 10 is long in the longitudinal direction and very narrow in the short direction, corresponding to the second opening 32 and the ink flow path 12. In this embodiment, the hydraulic diameter in this region will be determined. Based on these calculations, the hydraulic diameter dh1 in the smallest flow path section 19 is 60, and the hydraulic diameter dh2 in the gap 61 between the partition wall 15 and the partition wall 37 is 50, satisfying the relationship in equation (2).

[0037] The hydraulic diameter of the gap 61 between partition wall 15 and partition wall 37 is smaller than the hydraulic diameter of the minimum flow path section 19. Since a smaller hydraulic diameter results in greater resistance to the fluid, the ink flows more easily through the minimum flow path section 19 than through the gap 61. In other words, by satisfying the relationship in equation (2), ink leakage from the gap 61 can be sufficiently suppressed even without the interposition of an adhesive, and this does not hinder ink flow to the vicinity of the discharge energy generation section 17 or ink circulation within the flow path. Furthermore, since the same type of ink flows within the ink flow path, even if there is a minute leak from the gap 61 in the flow path partition wall, it will not cause any problems in terms of product functionality.

[0038] Furthermore, the values ​​for the ink channel partition width, the gap between the channel partitions, and the minimum ink channel width are not limited to those shown herein and can be appropriately changed according to various design conditions such as ink properties, the material of the ink channel components, and the internal pressure of the channel during ink flow. Furthermore, the ink channel substrate 30 is not limited to silicon in material, but can be made of polished metal, ceramic, or other materials as appropriate, as long as the flatness of the bonding surface with the recording element substrate 10 is sufficient for the allowable gap of the channel partition.

[0039] Figure 4(a) is a schematic perspective view of the ink channel member 80 with the side opposite to the adhesion surface with the ink channel substrate 30 (the first surface) facing upward. Figure 4(b) is a schematic perspective view of the ink channel member 80 with the adhesion surface with the ink channel substrate 30 (the second surface) facing upward. Figure 4(c) is a schematic plan view showing the planar configuration of the ink channel member 80 in this embodiment as seen from the side of the adhesion surface with the ink channel substrate 30. Figures 5(a), 5(b), and 5(c) are schematic diagrams showing the formation state of the ink channel by adhesion between the ink channel substrate 30 and the ink channel member 80 in this embodiment.

[0040] The ink channel member 80 has a second opening 82 on the bonding surface with the ink channel substrate 30, and a first opening 81 on the opposite surface. The first opening 81 and the second opening 82 are in communication within the ink channel member 80. The formation pitch of the first opening 81 and the second opening 82 is larger than the formation pitch of the openings 31 and 32 of the ink channel member 30, and plays a role in expanding the ink channel pitch. The bonding region 83 of the ink channel member 80 is composed of a region between the multiple second openings 82 which are elongated in the short direction of the ink channel member 80 and arranged parallel to each other with spacing in the longitudinal direction, and a region of the outer periphery surrounding all of the multiple second openings 82. Adhesive is applied to the ink channel substrate 30 or the ink channel member 80 so that the adhesive is in this bonding region 83, and the ink channel substrate 30 and the ink channel member 80 are bonded together.

[0041] Figure 5(b) is a cross-sectional view AA of Figure 5(a), and, similar to Figure 3(b), shows the path (arrow 70a) of the ink toward the vicinity of the ejection energy generation unit 17. Figure 5(c) is a cross-sectional view BB of Figure 5(a), and, similar to Figure 3(c), shows the path (arrow 70b) of the un-ejected ink returning from the vicinity of the ejection energy generation unit 17 to the first opening 81 of the ink flow path member 80. The ink paths shown in the cross-sectional views AA and BB are separated by an adhesive (not shown) at their respective second openings 82. In this embodiment, the recording element unit 1 is equipped with three ink flow path forming members, but the number of flow path forming members is not limited to this and can be increased or decreased as appropriate depending on the required flow path pitch and design configuration.

[0042] As described above, this embodiment makes it possible to suppress blockage of the ink flow path due to adhesive overflow without increasing the chip area. Therefore, the reliability of the recording performance of the recording device can be improved.

[0043] (Example 2) A recording element unit according to Embodiment 2 of the present invention will be described using Figure 6. The basic configuration and operation of the recording element unit of Embodiment 2 are the same as those of Embodiment 1. Therefore, elements in Embodiment 2 that have the same or equivalent functions and configurations as those in Embodiment 1 are denoted by the same reference numerals, and detailed explanations are omitted. Matters in Embodiment 2 that are not specifically described here are the same as those in Embodiment 1.

[0044] Figure 6 is a schematic cross-sectional view showing the formation of the ink channel by adhesion between the recording element substrate 10 and the ink channel substrate 30 in Example 2. Compared to Example 1, a filter 34 is formed in the ink channel of the ink channel substrate 30. This filter 34 prevents debris from entering the ink channel, thereby suppressing clogging of the ink outlet and poor ink discharge.

[0045] The filter 34 is, for example, an ink channel base formed by joining multiple silicon wafers. In the plate 30 and the recording element substrate 10, through holes smaller than the ink channels can be formed in the portion corresponding to the ink channels by silicon etching technology in at least one of the wafers to be bonded. In addition to silicon etching, methods such as forming through holes smaller than the ink channels on the silicon wafer on which the ink channel substrate 30 and the recording element substrate 10 are formed using a photosensitive resin and photolithography technology may also be applied as appropriate.

[0046] Note that the filter 34 is not limited to the form shown in Figure 6, and may be formed on, for example, the recording element substrate 10 or on ink flow path components such as the ink flow path member 80.

[0047] As described above, this embodiment provides the same effects as in Embodiment 1, and also prevents a decrease in reliability due to the intrusion of dust into the ink flow path.

[0048] (Example 3) A recording element unit according to Embodiment 3 of the present invention will be described with reference to Figure 7. The basic configuration and operation of the recording element unit of Embodiment 3 are the same as those of Embodiment 1. Therefore, elements in Embodiment 3 that have the same or equivalent functions and configurations as those in Embodiment 1 are denoted by the same reference numerals, and detailed explanations are omitted. Matters in Embodiment 3 that are not specifically described here are the same as those in Embodiment 1.

[0049] Figure 7 is a schematic cross-sectional view showing the formation of the ink channel by adhesion between the recording element substrate 10 and the ink channel substrate 30 in Example 3. Compared to Example 1, a damper film 35 is formed in the ink channel of the ink channel substrate 30. Due to the function of this damper film 35, the ejection driving force supplied to the ink from the ejection energy generation unit 17 is transmitted into the channel, thereby suppressing adverse effects on ink ejection.

[0050] The damper film 35 can be formed, for example, by forming a film of polyimide or the like on an opening made by silicon etching technology in an ink channel substrate 30 and a recording element substrate 10 formed by joining multiple silicon wafers. Furthermore, a similar configuration can be obtained by forming an elastic film, not limited to polyimide, on the ink channel substrate 30 and the recording element substrate 10.

[0051] The damper film 35 is not limited to the form shown in Figure 7, and may be formed on, for example, the recording element substrate 10 or on ink flow channel components such as the ink flow channel member 80.

[0052] As described above, this embodiment provides the same effects as in Example 1, and also makes it possible to control the flow characteristics within the ink channel according to the physical properties of the ink used.

[0053] (Example 4) Embodiment 4 of the present invention will be described using Figures 8(a) and 8(b). The basic configuration and operation of the recording element unit in Embodiment 4 are the same as those in Embodiment 1. Therefore, elements in Embodiment 4 that have the same or equivalent functions and configurations as those in Embodiment 1 are denoted by the same reference numerals, and detailed explanations are omitted. Matters in Embodiment 4 that are not specifically described here are the same as in Embodiment 1.

[0054] Figure 8(a) is a schematic plan view showing the ink channel substrate 30 in Embodiment 4 of the present invention. Figure 8(b) is a schematic cross-sectional view showing the formation state of the ink channel by adhesion between the recording element substrate 10 and the ink channel substrate 30 in Embodiment 4. In Embodiment 4, compared to Embodiment 1, the recording element substrate 10 and the ink channel substrate 30 are provided with ink channel color spacing walls. That is, different types (colors, etc.) of ink supplied from the multiple first openings 31 are provided. Therefore, the ink channels (liquid channels) formed between the recording element substrate 10 and the ink channel substrate 30 are divided into multiple independent ink channels for each type of ink. To this end, a third partition wall 15b is provided on the recording element substrate 10, and a fourth partition wall 18 is provided on the ink channel substrate 30 so as to be connected to it in the stacking direction. Adhesive 60 is interposed between partition walls 15b and 18 to bond them together. With this configuration, the liquid channels can be separated for each type of ink, and when the technology of the present invention is applied to a recording device equipped with a multi-color head, it becomes possible to realize a configuration that suppresses the mixing of multiple types of ink. In this embodiment, the width (thickness) of partition walls 15b and 18 is set to a value of 300 μm or more, taking into account the excess adhesive 80. This value can be changed as appropriate by providing a region for the excess adhesive to escape.

[0055] As described above, this embodiment provides the same effects as in Examples 1 to 3, and also enables the formation of highly reliable ink channels compatible with multiple types of ink. Therefore, this embodiment can improve the reliability of ink ejection and thus the reliability of the recording performance of the recording device. Note that this embodiment is not limited to the configuration shown in Figure 8, and the same configuration can be applied to various channel shapes.

[0056] The configurations shown in each of the above embodiments can be combined with each other, as long as there are no technical inconsistencies. [Explanation of Symbols]

[0057] 1…Liquid ejection recording head, 2…Liquid ejection recording element unit, 10…Recording element substrate, 11…Electrode PAD, 12…Ink flow path, 14…Ink ejection port, 15…Ink flow path partition, 16…Ink flow path partition width, 17…Ejection energy generation unit, 18…Ink flow path color spacing wall, 19w…Minimum ink flow path width, 20…Drive IC, 21…Electrode PAD, 22…Bonding wire, 30…Ink flow path substrate, 31…First opening of ink flow path substrate, 32…Second opening of ink flow path substrate, 33…Adhesive contact area of ​​ink flow path substrate, 34…Filter, 35…Damper film, 40…Ejection port surface cover, 50…Electrical wiring member, 60…Adhesive, 61…Gap in ink flow path partition, 62…Sealing material for electrical mounting part, 70…Ink flow, 80…Ink flow path member, 81…First opening of ink flow path member, 82…Second opening of ink flow path member, 83…Adhesive contact area of ​​ink flow path member

Claims

1. A first substrate comprising: a first partition wall that demarcates a first flow path including a plurality of discharge ports for discharging liquid for image recording; and an energy generating unit that generates energy to discharge the liquid from the first flow path through the discharge ports; A second substrate is laminated and bonded to the first substrate with an adhesive so as to be connected to the first substrate, comprising a second partition wall that demarcates a second flow path including a supply port for supplying liquid, and the second flow path communicates with the first flow path. In a liquid discharge recording element unit equipped with, The first partition wall and the second partition wall are connected in the stacking direction of the first substrate and the second substrate with a predetermined gap between them without an adhesive interposed between them. A liquid discharge recording element unit characterized in that the hydraulic diameter of the gap is smaller than the hydraulic diameter of the smallest flow path portion having the smallest flow path cross-sectional area in the first flow path.

2. The liquid ejection recording element unit according to claim 1, characterized in that the first substrate and the second substrate are silicon substrates.

3. The liquid ejection recording element unit according to claim 1 or 2, characterized in that the thickness of the portion forming the gap in the first partition wall is 100 μm to 200 μm.

4. The liquid ejection recording element unit according to any one of claims 1 to 3, characterized in that the predetermined opposing distance is 25 μm or less.

5. The liquid ejection recording element unit according to any one of claims 1 to 4, characterized in that the first substrate and the second substrate are bonded together via an adhesive applied only to the outer periphery of the bonding surface.

6. The liquid flow path that connects from the supply port, through the second flow path and the first flow path, to the plurality of discharge ports is configured such that liquid that is not discharged from the plurality of discharge ports can circulate within the liquid flow path, as described in any one of claims 1 to 5.

7. The liquid discharge recording element unit according to claim 6, further comprising a filter provided in the liquid flow path.

8. The liquid discharge recording element unit according to claim 6, further comprising a damper membrane provided in the liquid flow path.

9. The second substrate is provided with a plurality of supply ports, The liquid discharge recording element unit according to any one of claims 1 to 8, characterized in that the liquid supplied from each of the multiple supply ports is of the same type.

10. The second substrate is provided with a plurality of supply ports, The liquid flow path that connects from the multiple supply ports through the second flow path and the first flow path to the multiple discharge ports is divided into multiple liquid flow paths corresponding to the types of liquid supplied from each of the multiple supply ports. The first substrate divides the first flow path into a plurality of first flow paths and has a third partition wall that divides the plurality of discharge ports corresponding to the divided plurality of first flow paths. The second substrate has a fourth partition wall that divides the second channel into a plurality of second channels corresponding to the plurality of divided first channels, The liquid ejection recording element unit according to any one of claims 1 to 8, characterized in that the third partition wall and the fourth partition wall are bonded together with an adhesive in the stacking direction.

11. The liquid ejection recording element unit according to claim 10, characterized in that the thickness of the portion of the third partition wall and the fourth partition wall that is bonded together with the adhesive is greater than the thickness of the portion of the first partition wall that forms the gap.

12. The liquid ejection recording element unit according to claim 10 or 11, characterized in that the thickness of the portion of the third partition wall and the fourth partition wall that is bonded together with the adhesive is 300 μm or more.

13. A first substrate comprising: a first partition wall that demarcates a first flow path including a plurality of discharge ports for discharging liquid for image recording; and an energy generating unit that generates energy to discharge the liquid from the first flow path through the discharge ports; A second substrate is laminated and bonded to the first substrate with an adhesive so as to be connected to the first substrate, comprising a second partition wall that demarcates a second flow path including a supply port for supplying liquid, and the second flow path communicates with the first flow path. A method for manufacturing a liquid discharge recording element unit comprising: A substrate manufacturing process for manufacturing the first substrate and the second substrate, A lamination step of bonding the first substrate and the second substrate together with an adhesive and stacking them, In a method for manufacturing a liquid ejection recording element unit including, A method for manufacturing a liquid ejection recording element unit, characterized in that, in the lamination step, no adhesive is applied to the gap between the first partition wall and the second partition wall that are connected in the lamination direction of the first substrate and the second substrate, and the first substrate and the second substrate are laminated such that the hydraulic diameter of the gap is smaller than the hydraulic diameter of the smallest channel section having the smallest channel cross-sectional area in the first channel.

14. The method for manufacturing a liquid ejection recording element unit according to claim 13, characterized in that the first substrate and the second substrate are manufactured by silicon etching in the substrate manufacturing process.

15. The method for manufacturing a liquid ejection recording element unit according to claim 13 or 14, characterized in that, in the substrate manufacturing process, the first substrate is manufactured such that the thickness of the portion forming the gap in the first partition wall is in the range of 100 μm to 200 μm.

16. A method for manufacturing a liquid ejection recording element unit according to any one of claims 13 to 15, characterized in that, in the lamination step, the first substrate and the second substrate are laminated such that the distance between the first partition wall and the second partition wall in the gap is 25 μm or less.

17. A method for manufacturing a liquid ejection recording element unit according to any one of claims 13 to 16, characterized in that, in the lamination step, an adhesive is applied only to the outer periphery of the bonding surface between the first substrate and the second substrate to bond the first substrate and the second substrate together.

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