Liquid discharge head and liquid discharge device

Abstract

To provide a liquid discharge head that can suppress an adhesive from protruding from a joint region at a site where flow paths such as a bulkhead are not formed, while allowing the adhesive from protruding when the adhesive bonds substrates to each other.SOLUTION: A liquid discharge head comprises a liquid discharge substrate for discharging liquid. The liquid discharge substrate is configured to have a first substrate in which a flow path of liquid is formed and a second substrate bonded to the first substrate through an adhesive. The first substrate has a bonded region that is bonded to the second substrate, where the flow path is formed adjacent to only one side in the first substrate. A concave part is formed in the bonded region and the adhesive is stored in the concave part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a liquid ejection head and a liquid ejection apparatus, and more particularly to a technique for stacking and bonding together a plurality of substrates that constitute a liquid ejection head. [Background technology]

[0002] Some liquid ejection heads are formed by laminating a flow path substrate, in which flow paths for supplying liquid such as ink to ejection ports are formed, on a support substrate. Patent Document 1 describes that the laminated substrates are bonded together with an adhesive. In more detail, the adhesive is prevented from spilling out of the bonded portion by controlling the undulation of the adhesive layer when the adhesive layer is transferred to the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-61022 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the adhesive overflows, the overflowing adhesive moves onto the wall surfaces of the partition walls that form the flow paths of the flow path forming substrate and onto the support substrate, forming an adhesive layer not only on the adhesive portion of the partition wall but also on the portion connected thereto. As a result, for example, when an adhesive layer is used to prevent ink leakage between adjacent flow paths via the partition wall, the overflow can increase the portion of the adhesive layer that prevents ink leakage. From this point of view, it can be said that it is desirable to have as much adhesive overflow onto the wall surfaces of the partition walls and onto the support substrate as possible, as long as this does not cause problems such as blocking of the flow paths.

[0005] On the other hand, if the amount of adhesive is increased in an attempt to increase the amount of adhesive that protrudes around the partition walls, a large amount of adhesive will be poured into the bonding region where the support substrate is bonded in the portions of the flow path forming substrate where no flow paths are formed, such as the partition walls, etc. As a result, a large amount of adhesive may protrude into the flow paths adjacent to the bonding region, causing problems such as blockage of the flow paths.

[0006] The object of the present disclosure is to provide a liquid ejection head and a liquid ejection device that can tolerate the overflow of adhesive when bonding substrates together, while suppressing the overflow of adhesive from bonding areas in areas that do not form flow paths, such as partitions. [Means for solving the problem]

[0007] The liquid ejection head of the present disclosure includes a liquid ejection substrate for ejecting liquid, the liquid ejection substrate being configured to include a first substrate having a liquid flow path formed therein, and a second substrate bonded to the first substrate via an adhesive, the first substrate having a bonding region where the flow path is adjacent to only one side of the first substrate, a recess formed in the bonding region, and adhesive contained in the recess. Effect of the Invention

[0008] According to the above configuration, in the liquid ejection head, it is possible to prevent the adhesive from spilling out from the joining area of ​​the partition wall or other parts that do not form a flow path, while allowing the adhesive to spill out when joining the substrates together. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a cross section of a portion of a liquid ejection substrate that constitutes a liquid ejection head according to a first embodiment of the present disclosure. [Diagram 2] 2 is a cross-sectional view of a portion of the liquid ejection substrate shown in FIG. [Diagram 3] 3 is a diagram showing a portion A of the liquid ejection substrate shown in FIG. 2. [Figure 4]4(a) is a diagram of the flow path forming substrate of the liquid ejection substrate shown in Fig. 1, viewed from the underside thereof, and Fig. 4(b) is an enlarged view of part B in Fig. 4(a). [Diagram 5] FIG. 5 is a diagram showing a state in which two liquid ejection substrates shown in FIG. 4(a) are joined to each other. [Figure 6] FIG. 6 is an enlarged view of part C in FIG. 5. [Figure 7] 5 is a diagram showing a schematic view of a recess in a part of the bonding region in FIG. 4(b). FIG. [Figure 8] FIG. 4 is a diagram showing a liquid ejection substrate according to a second embodiment of the present disclosure. [Figure 9] 1 is a perspective view illustrating a liquid ejection head according to an embodiment of the present disclosure. [Figure 10] 1 is a perspective view showing a schematic diagram of an ink jet recording apparatus according to an embodiment of a liquid ejection apparatus; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of each component of the embodiments described below may be changed as appropriate depending on the configuration of the liquid ejection substrate of the liquid ejection head to which the present disclosure is applied, and various conditions. The scope of the present disclosure is not limited to the embodiments described below.

[0011] (Embodiment 1) Fig. 1 is a perspective view showing a cross section of a part of a liquid ejection substrate constituting a liquid ejection head according to this embodiment, and Fig. 2 is a cross section of a part of the liquid ejection substrate shown in Fig. 1. As shown in Fig. 1 and Fig. 2, the liquid ejection substrate 10 includes a flow path forming substrate (hereinafter also referred to as a first substrate) 100, a support substrate (hereinafter also referred to as a second substrate) 300 joined to the flow path forming substrate 100 via an adhesive 200, and an energy generating element 400 provided on the flow path forming substrate 100 and configured to generate energy used to eject liquid.

[0012] The liquid ejection substrate 10 of this embodiment is mounted in an inkjet recording device as a liquid ejection device and ejects ink as a liquid.

[0013] A flow path layer 150 and a nozzle layer 160 are laminated on an upper surface (hereinafter also referred to as a first surface) 111 of the flow path forming substrate 100 in ranges corresponding to the portions to be formed, and ejection ports 120, pressure chambers 118, etc. are formed. A lower surface (hereinafter also referred to as a second surface) 112 of the flow path forming substrate 100 is bonded to a support substrate 300 via an adhesive 200 in accordance with the portions, as described later. In addition, a pitch conversion flow path 320 connected to a common flow path 132 formed in the flow path forming substrate 100 is formed in the support substrate 300.

[0014] The liquid ejection substrate 10 according to the present embodiment described above is divided into a flow path region 130 and a joining region 140 in a direction perpendicular to the arrangement direction of the ejection ports 120, as shown in FIG.

[0015] In the flow channel region 130, there are a common flow channel 132 for supplying liquid to the energy generating elements 400, individual flow channels 134 communicating with the common flow channel 132, and pressure chambers 118 in which the energy generating elements 400 are provided. The liquid reaches the pressure chambers 118 through the individual flow channels 134 from the common flow channel 132, and the liquid that reaches the pressure chambers 118 is ejected from the ejection ports 120 communicating with the pressure chambers 118 as the energy generating elements 400 generate energy. The common flow channel 132 also has a supply flow channel 132a for supplying liquid to the energy generating elements 400, and a recovery flow channel 132b for recovering the liquid that is supplied to the energy generating elements 400 and not used for ejection. In this way, the flow channel region 130 is a region in which the lower surface 112 of the partition wall 136 for forming each flow channel is bonded to the support substrate 300 by the adhesive 200. FIG. 3 is a diagram showing part A of the liquid ejection substrate shown in FIG. 2. The lower surface 112 of the partition wall 136 in the flow path forming substrate 100 is bonded to the upper surface (hereinafter also referred to as the third surface) 311 of the support substrate 300 via the adhesive 200. At this time, the overflowing adhesive moves to the lower parts of the wall surfaces 136a and 136b on both sides of the partition wall 136 forming the common flow path 132 and to a part of the upper surface 311 of the support substrate 300 adjacent to the partition wall 136, and hardens. As a result, the ink leak path IP, which is a passage for preventing ink from moving back and forth between the flow paths, can be lengthened, and a highly reliable liquid ejection head without unnecessary inflow or outflow of ink can be obtained. Note that, since different types of liquids may be flowed in the common flow path 132, the overflowing adhesive at the partition wall 136 can also prevent the adverse effects of a decrease in the circulation flow rate and liquid mixing.

[0016] 1 and 2 again, the bonding region 140 is a region in the flow path forming substrate 100 where the flow path is adjacent to only one side. That is, the portion in this region where the lower surface 112 of the flow path forming substrate 100 is bonded to the support substrate 300 is a region where ink does not leak through this bonding portion. A plurality of recesses (grooves) 142 for receiving adhesive are provided on the lower surface side of the flow path forming substrate 100 in this region. That is, when the lower surface 112 of the flow path forming substrate 100 is bonded to the upper surface 311 of the support substrate 300 via the adhesive 200, the adhesive 200 applied to the portion of the bonding region 140 adjacent to the common flow path 132 is received in the recesses 142. This makes it possible to suppress the adhesive from overflowing into the common flow path 132 adjacent to the bonding region 140, and to prevent the flow path from being blocked by the adhesive.

[0017] In this embodiment, the energy generating element 400 is a heating resistor, but may be in another form, for example, a piezoelectric element. Wiring for supplying power to the energy generating element 400 and pads for connecting electrodes are not shown. The adhesive 200 is preferably made of a material that has high adhesion to the flow path forming substrate 100 and the support substrate 300, and is preferably made of a material that has little air bubbles and is highly coatable, and is preferably made of a low viscosity material that makes it easy to reduce the thickness of the adhesive 200. For example, the adhesive 200 may contain any resin selected from the group consisting of epoxy resin, acrylic resin, silicone resin, benzocyclobutene resin, polyamide resin, polyimide resin, and urethane resin.

[0018] Furthermore, the adhesive 200 may be cured by a heat curing method or an ultraviolet delayed curing method. When the flow path forming substrate 100 or the support substrate 300 has ultraviolet light transparency, the adhesive 200 may be cured by an ultraviolet light.

[0019] Moreover, as a method for applying the adhesive 200, an adhesive transfer method depending on the substrate to be used can be mentioned. Specifically, a transfer substrate is prepared, and the adhesive 200 is applied thinly and uniformly on the transfer substrate by a spin coating method or a slit coating method. Thereafter, the applied adhesive 200 is brought into contact with the second surface 112 of the flow path forming substrate 100, so that the adhesive 200 can be transferred only to the second surface 112 of the flow path forming substrate 100. The size of the transfer substrate is preferably equal to or larger than the size of the flow path forming substrate 100. As the transfer substrate, silicon, glass, or a film such as PET, PEN, or PI is preferably used. Furthermore, as a method for directly forming the adhesive 200 on the flow path forming substrate 100, screen printing and dispense coating can be mentioned. Although the above description is given by taking the flow path forming substrate 100 as an example, the adhesive may be applied to the third surface 311 of the support substrate 300 to be bonded to the flow path forming substrate 100 as the same application method.

[0020] The flow path forming substrate 100 and the support substrate 300 coated with the adhesive 200 are bonded by heating the flow path forming substrate 100 and the support substrate 300 to a predetermined temperature in a bonding device, and then pressing them for a predetermined time and pressure. These bonding parameters are appropriately set depending on the adhesive material. In addition, in order to prevent air bubbles from entering the bonding portion of the flow path forming substrate 100 and the support substrate 300, it is preferable to bond the flow path forming substrate 100 and the support substrate 300 in a vacuum.

[0021] When the adhesive 200 is a thermosetting type, the adhesive 200 may be heated in a bonding device until it hardens. The bonded substrate assembly may be removed after bonding and heated in an oven or the like to promote the hardening of the adhesive 200. On the other hand, when the adhesive 200 is an ultraviolet delay type, the flow path forming substrate 100 is bonded to the support substrate 300 after a specified amount of ultraviolet light is irradiated to the adhesive 200 before bonding the support substrate 300 to the flow path forming substrate 100. After bonding the support substrate 300 to the flow path forming substrate 100, it is preferable to further heat the substrate assembly to sufficiently promote the hardening of the adhesive 200. When the adhesive 200 is an ultraviolet hardening type, after bonding the flow path forming substrate 100 and the support substrate 300, a specified amount of ultraviolet light is irradiated to the adhesive 200 on a substrate (the flow path forming substrate 100 and / or the support substrate 300) having ultraviolet light transparency to cure the adhesive 200. After the flow path forming substrate 100 is joined to the support substrate 300, it is preferable to further heat the substrate assembly to sufficiently promote hardening of the adhesive 200.

[0022] 4(a) is a view of the flow path forming substrate 100 of the liquid ejection substrate 10 shown in FIG. 1 as seen from its underside, and FIG. 4(b) is an enlarged view of part B in FIG. 4(a). As shown in FIG. 4(a) and FIG. 4(b), the recesses 142 are arranged in a staggered manner, thereby maintaining the rigidity of the substrate. Specifically, when the longitudinal direction of the common flow path 132 is defined as a first direction D1, the recesses 142 are arranged continuously in the first direction D1, and are arranged every other recess in a second direction D2 perpendicular to the first direction D1. In this embodiment, the recesses 142 are arranged along the longitudinal end 121a of the flow path forming substrate 100.

[0023] FIG. 5 is a diagram showing a state where two liquid ejection substrates shown in FIG. 4(a) are joined together, with the support substrate 300 omitted. FIG. 6 is an enlarged view of part C in FIG. 5. As shown in FIGS. 5 and 6, the recesses 142 are formed in the joining region 140 where the common flow path 132 is not formed. Here, the distance L1 between the end of the recess 142 closest to the common flow path in the arrangement of the recesses 142 and the end of the common flow path 132 adjacent to the recess 142 is set to be longer than the width 136c of the partition wall 136. This makes it possible to secure an adhesive area that allows the flow path forming substrate 100 and the support substrate 300 to be stably joined. As a result, the adhesive area of ​​the region of the distance L1 between the recesses 142 and the partition wall 136 can be made larger than the adhesive area of ​​one partition wall 136, and a highly reliable liquid ejection head can be obtained.

[0024] Furthermore, in this embodiment, when the recess 142 is not provided in the flow-path forming substrate 100, under the conditions that the distance L1 is 150 μm or more and the thickness of the adhesive 200 is between 0.5 μm and 4.0 μm, the adhesive that is not contained in the recess 142 may protrude into the common flow path 132 and cause blockage of the common flow path 132. That is, when the distance L1 is 150 μm or more and the thickness of the adhesive 200 is between 0.5 μm and 4.0 μm, it is desirable to provide the recess 142 in the bonding region 140 of the flow-path forming substrate 100.

[0025] FIG. 7 is a diagram showing a schematic view of a recess 142 in a part of the bonding region in FIG. 4(b). As shown in FIG. 7, the recesses 142a, 142b, 142c, and 142d are rectangular with a side length L of 10 μm to 50 μm, and the four corners 143 may be arcs. Furthermore, the opening ratio of the recesses 142a, 142b, 142c, and 142d per unit area in the bonding region 140 is 5% to 30%. That is, the area of ​​the recesses 142a, 142b, 142c, and 142d is 5% to 30% per unit area of ​​the bonding region 140. This unit area is the area of ​​a rectangle including the four recesses 142a, 142b, 142c, and 142d and having two sides with a length of 2A, as shown in FIG. The opening ratio may be determined comprehensively in consideration of the amount of adhesive 200 to be transferred, the opening shape of the flow path, the allowable amount of adhesive overflowing, and the like.

[0026] In this embodiment, the recesses 142a, 142b, 142c, and 142d have a side length L of 30 μm and an arc length R of the corner 143 of 6 μm. A distance A1 between the centers of two adjacent recesses 142a and 142b along the longitudinal end 121a of the flow path forming substrate 100 is 90 μm, and a distance A2 between the centers of two adjacent recesses 142a and 142c along the lateral end 121b of the flow path forming substrate 100 is 90 μm. A shift amount B between the centers of the two adjacent recesses 142a and 142c along the lateral end 121b of the flow path forming substrate 100 (see FIG. 4(b)) is 37.5 μm.

[0027] As shown in Fig. 7, when four recesses 142a, 142b, 142c, and 142d are taken as one set, the set has a rectangular shape, the length 2A of one side of the set is 180 μm, and the recesses are arranged inside the bonding region 140 as shown in Fig. 4(b). In this case, the opening ratio of the recesses 142a, 142b, 142c, and 142d per unit area is 10%. In other words, the area of ​​the recesses 142a, 142b, 142c, and 142d is 10% per unit area of ​​the bonding region 140. Other dimensional examples are shown in Table 1 below. JPEG2025031318000002.jpg35170 (Table 1) In the method of manufacturing the liquid ejection substrate of the liquid ejection head in this embodiment, the energy generating elements 400 made of TaSiN and used to eject droplets, an electric circuit (not shown) that drives the energy generating elements 400, and an electric connection part (not shown) that is electrically connected to the electric connection substrate are disposed on the flow path forming substrate 100. In detail, the flow path forming substrate 100 is made of silicon, and may be thinned down to a thickness of 625 μm by a grinding device.

[0028] Also, a flow channel for distributing liquid and a recess 142 for accommodating the adhesive 200 are formed in the flow channel-forming substrate 100. In detail, in order to form the recess 142 for accommodating the adhesive 200 or the flow channel for distributing liquid, anisotropic etching is performed using the Bosch process, which is a type of reactive ion etching, or TMAH, KOH, or the like. The Bosch process is capable of forming vertical etching grooves in the flow channel-forming substrate 100 by alternately performing coating and etching. Furthermore, blind holes can be formed and the flow channel-forming substrate 100 can be thinned by back grinding or CMP to allow penetration.

[0029] In detail, a resist is patterned from the second surface 112 of the flow channel forming substrate 100 using a photolithography technique, and then dry etching is performed using a Bosch process. For example, when the common flow channel 132 is processed to a depth of 475 μm, the recess 142 can be processed to a depth of 250 to 300 μm. The reason why the recess 142 is shallower than the common flow channel 132 is due to the influence of a microloading effect caused by the difference in the opening area. In addition, the recess 142 can be formed by simultaneously patterning and etching the common flow channel 132, but when the volume of the recess 142 is to be adjusted individually, the common flow channel 132 and the recess 142 can also be patterned and etched individually.

[0030] Similarly, the individual flow paths 134 are formed from the first surface 111 of the flow path forming substrate 100, and the common flow path 132 and the individual flow paths 134 are connected to each other.

[0031] The support substrate 300 is made of silicon and has a thickness of 725 μm. A resist is patterned from a fourth surface 312 opposite to a third surface 311 bonded to the flow path forming substrate 100 using photolithography technology in the same manner as the flow path forming substrate 100, and blind holes are processed to a depth of 320 μm by dry etching using the Bosch process. Thereafter, the substrate is thinned to 300 μm by back grinding and CMP from the third surface 311, and the blind holes are penetrated to form a pitch conversion flow path 320 connected to the common flow path 132.

[0032] Next, a substrate for adhesive transfer was prepared, and a benzocyclobutene solution was spin-coated to a thickness of 7 μm as the adhesive 200. A PET film was used as the substrate for transfer. After coating, a bake treatment was performed at 100° C. for 5 minutes to volatilize the solvent. The adhesive formed on the substrate for transfer was brought into contact with the second surface 112 of the flow path forming substrate 100 while applying heat, thereby transferring the adhesive 200 to the flow path forming substrate 100, and the thickness after transfer to the flow path forming substrate 100 was 2.5 μm.

[0033] Also, the flow path forming substrate 100 and the support substrate 300 are aligned using a bonding alignment device and heated in a vacuum to bond them. For example, bonding may be performed at a vacuum level of 100 Pa or less and a temperature of 150° C. When the adhesive overflowing into the common flow path 132 after bonding was checked, the thickness of the adhesive overflowing from the partition wall 136 forming the common flow path 132 was equal to or less than the thickness of the adhesive overflowing from the other parts of the common flow path 132.

[0034] After the flow path forming substrate 100 and the support substrate 300 are bonded and cooled, they are removed from the apparatus and heat treated in an oven in a nitrogen atmosphere at 250° C. for 1 hour to harden the adhesive.

[0035] Next, a negative photosensitive resin dissolved in a PGMEA solvent is spin-coated onto a PET film, dried at 100°C in an oven to form a dry film, which is then transferred to the first surface 111 of the flow path forming substrate 100, and the PET film is peeled off to form a photosensitive resin layer. The photosensitive resin layer is exposed to a pattern that will become the flow path, and then PEB is performed to create a latent image. Next, a dry film is laminated in the same manner, and a pattern that will become the nozzle is exposed, and then PEB is performed to develop the flow path and nozzle together, completing a wafer for a liquid ejection head.

[0036] A wafer for a liquid ejection head is manufactured by forming multiple modified layers inside a silicon substrate in the thickness direction of the substrate (flow path forming substrate 100 or support substrate 300) using stealth dicing with a laser, and by applying an external force to the wafer, cracks progress between the modified portions, allowing the wafer to be fractured and a liquid ejection substrate to be obtained.

[0037] (Embodiment 2) FIG. 8 is a diagram showing a liquid ejection substrate according to a second embodiment of the present disclosure, and shows the liquid ejection substrate from the support substrate side without the support substrate. In this embodiment, the recess 142 is provided without following the longitudinal direction of the common flow channel 132. In detail, in the flow channel region 130 formed by bonding the flow channel forming substrate 100 and the support substrate 300 with the adhesive 200, the distance 130a between the end 133 of the common flow channel 132 and the end 121b in the lateral direction of the flow channel forming substrate 100 is 150 μm or more, and the thickness of the adhesive 200 is between 0.5 μm and 4.0 μm. If the recess 142 is not provided in this dimensional relationship, the adhesive may overflow into the common flow channel 132, thereby causing blockage of the flow channel, etc.

[0038] In this embodiment, when the distance 130a is 150 μm or more and the thickness of the adhesive 200 is 0.5 μm to 4.0 μm, the recess 142 is provided along the short-side end 121b of the flow path forming substrate 100. In this embodiment, the flow path region 130 is multiple, and an extension portion 146 of the bonding region 140 is formed between two adjacent flow path regions 130, and the recess 142 is also provided in the extension portion 146. It is desirable that the bonding region 140 is spaced a distance L2 from the common flow path 132 adjacent to the bonding region 140. For example, in order to ensure an adhesion area that can stably bond the flow path forming substrate 100 and the support substrate 300, the distance L2 may be longer than the width 136c of the partition wall 136 that separates the common flow path 132. This ensures that the adhesion area between the adhesive 200 and the region between the recess 142 and the partition wall 136 is greater than the adhesion area between the adhesive 200 and one partition wall 136, thereby improving the reliability of the liquid ejection head.

[0039] In this embodiment, the distance 130a from the end 133 of the common flow channel 132 to the short-side end 121b of the flow channel forming substrate 100 is 150 μm or more, and the distance 137 between two adjacent flow channel regions 130 is 150 μm or more.

[0040] In this embodiment, by providing a recess 142 in the flow path forming substrate 100, when the flow path forming substrate 100 is bonded to the support substrate 300 via the adhesive 200, the amount of adhesive that overflows from the partition 136 separating the common flow paths 132 is maintained while suppressing overflow of the adhesive into the common flow paths 132 adjacent to the bonding region 140 of the flow path forming substrate 100, and the occurrence of leaks between the common flow paths 132 can be prevented, thereby obtaining a highly reliable liquid ejection substrate.

[0041] Fig. 9 is a perspective view showing a liquid ejection head according to an embodiment of the present disclosure. As shown in Fig. 9, the liquid ejection head 3 is formed by joining a plurality of liquid ejection substrates 10 having the above-mentioned configuration. In detail, the liquid ejection head 3 is a line-type liquid ejection head in which 17 liquid ejection substrates 10 capable of ejecting ink are arranged in a straight line (arranged in-line). The liquid ejection head 3 includes a signal input terminal and a power supply terminal electrically connected to each liquid ejection substrate 10 via a flexible wiring substrate 40 or the like.

[0042] 10 is a perspective view showing a schematic diagram of an inkjet recording apparatus according to an embodiment of a liquid ejection device. The inkjet recording apparatus 1000 is equipped with liquid ejection heads 3 that eject cyan (C), magenta (M), yellow (Y) and black (Bk) inks. The recording apparatus 1000 records an image on the recording medium P by ejecting ink from these liquid ejection heads 3 onto the recording medium P in accordance with recording data. In the figure, the X direction is the transport direction of the recording medium P, the Y direction is the width direction of the recording medium, and the Z direction is the vertical upward direction.

[0043] The liquid ejection device is not limited to the above-mentioned recording device. For example, the liquid ejection device may be a single-function printer having only a recording function, or a multifunction printer having multiple functions such as a recording function, a FAX function, and a scanner function. The liquid ejection device may also be a manufacturing device for manufacturing color filters, electronic devices, optical devices, microstructures, etc. using a predetermined recording method, or a microbubble generating device.

[0044] (Other embodiments) It is clear from the above description that any combination of the first and second embodiments described above is included in the embodiments of the present invention as long as it is not contrary to the spirit of the present invention.

[0045] The present disclosure includes configurations typified by the following liquid ejection head and liquid ejection device examples.

[0046] <Configuration 1> A liquid ejection head including a liquid ejection substrate for ejecting liquid, the liquid ejection substrate includes a first substrate having a liquid flow path formed therein, and a second substrate bonded to the first substrate via an adhesive; the first substrate has a bonding region to be bonded to the second substrate, the bonding region being adjacent to a flow path on only one side of the first substrate, and a recess is formed in the bonding region; The liquid ejection head is characterized in that an adhesive is contained in the recess.

[0047] <Configuration 2> 2. The liquid ejection head according to configuration 1, wherein the first substrate has a partition wall configured to form a flow path for the liquid.

[0048] <Configuration 3> 3. The liquid ejection head according to configuration 2, wherein the distance between the recess and the partition wall adjacent to the recess is greater than the width of the partition wall.

[0049] <Configuration 4> 2. The liquid ejection head according to configuration 1, wherein the opening of the recess is rectangular.

[0050] <Component 5> 2. The liquid ejection head according to configuration 1, wherein in the bonding region, an opening ratio of the recesses per unit area is 5% to 30%.

[0051] <Component 6> 2. The liquid ejection head according to configuration 1, wherein the recess is provided along an end portion in the longitudinal direction of the first substrate.

[0052] <Component 7> 2. The liquid ejection head according to configuration 1, wherein the recess is provided along an end portion in a lateral direction of the first substrate.

[0053] <Component 8> The liquid ejection head described in configuration 1, characterized in that there are multiple recesses, the recesses are arranged in the longitudinal direction of the common flow path, and are arranged every other recess in a direction perpendicular to the longitudinal direction of the common flow path.

[0054] <Component 9> 4. The liquid ejection head according to configuration 3, wherein the width of the partition is 150 μm or more.

[0055] <Component 10> 10. The liquid ejection head of configuration 9, wherein the adhesive has a thickness of 0.5 to 4.0 μm when the second substrate is bonded to the bonding area of ​​the first substrate.

[0056] <Component 11> A liquid ejection head including a liquid ejection substrate for ejecting liquid, the liquid ejection substrate includes a first substrate having a liquid flow path formed therein, and a second substrate bonded to the first substrate via an adhesive; the first substrate has a bonding region to be bonded to the second substrate, the bonding region being adjacent to a flow path on only one side of the first substrate, and a recess is formed in the bonding region; A liquid ejection head in which an adhesive is accommodated in the recess. a liquid ejection head for ejecting ink from the liquid ejection head onto a recording medium to perform recording. [Explanation of symbols]

[0057] 10 Liquid discharge board 100 Flow path forming substrate 140 Junction area 142 Recess 200 Adhesive 300 Support substrate

Claims

1. A liquid ejection head including a liquid ejection substrate for ejecting liquid, the liquid ejection substrate includes a first substrate having a liquid flow path formed therein, and a second substrate bonded to the first substrate via an adhesive; the first substrate has a bonding region to be bonded to the second substrate, the bonding region being adjacent to a flow path on only one side of the first substrate, and a recess is formed in the bonding region; The liquid ejection head is characterized in that an adhesive is contained in the recess.

2. The liquid ejection head according to claim 1 , wherein the first substrate has a partition wall configured to form a flow path for the liquid.

3. 3. The liquid ejection head according to claim 2, wherein a distance between the recess and the partition wall adjacent to the recess is greater than a width of the partition wall.

4. 2. The liquid ejection head according to claim 1, wherein the opening of the recess is rectangular.

5. 2. The liquid ejection head according to claim 1, wherein an opening ratio of the recesses per unit area in the bonding region is 5% to 30%.

6. The liquid ejection head according to claim 1 , wherein the recess is provided along an end portion in a longitudinal direction of the first substrate.

7. The liquid ejection head according to claim 1 , wherein the recess is provided along an end portion in a lateral direction of the first substrate.

8. 2. The liquid ejection head according to claim 1, wherein the recesses are arranged in a longitudinal direction of the common flow path, and arranged every other recess in a direction perpendicular to the longitudinal direction of the common flow path.

9. 4. The liquid ejection head according to claim 3, wherein the partition has a width of 150 [mu]m or more.

10. 10. The liquid ejection head according to claim 9, wherein the adhesive has a thickness of 0.5 to 4.0 [mu]m when the second substrate is bonded to the bonding area of ​​the first substrate.

11. A liquid ejection head including a liquid ejection substrate for ejecting liquid, the liquid ejection substrate includes a first substrate having a liquid flow path formed therein, and a second substrate bonded to the first substrate via an adhesive; the first substrate has a bonding region to be bonded to the second substrate, the bonding region being adjacent to a flow path on only one side of the first substrate, and a recess is formed in the bonding region; A liquid ejection head in which an adhesive is accommodated in the recess. a liquid ejection head for ejecting ink from the liquid ejection head onto a recording medium to perform recording.

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