Joint member, liquid ejection head, liquid ejection unit, and liquid ejection device

Abstract

To provide a bonding member which enables easy evaluation of a bonding state, and to provide a liquid discharge head, a liquid discharge unit, and a liquid discharge apparatus.SOLUTION: An actuator substrate 2 forming a bonding member 100 is provided with a surface structure 115 facing a facing surface structure 204 of a holding substrate 50. The surface structure 115 has a first surface part 115a. The first surface part 115a is lower than a bonding surface 29 of the actuator substrate 2 to be bonded to a bonding surface 59 of the holding substrate 50. The facing surface structure 204 of the holding substrate 50 is provided with a through hole 207 which is open facing a part of the first surface part 115a and has a cross-sectional area narrower than an area of the first surface part.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to a joining member, a liquid ejection head, a liquid ejection unit, and an apparatus for ejecting liquid. [Background technology]

[0002] For example, some liquid ejection heads include a nozzle plate, a flow path plate, a wall member, a holding substrate (protective member), a common flow path member, and the like, which are joined together with an adhesive to form a joining member (bonding member).

[0003] Conventionally, when a holding substrate is attached with adhesive to a substrate having a plurality of electromechanical conversion elements, it is known to provide the holding substrate with a leg for checking the adhesion state, which is attached to the substrate by the adhesive (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-069654 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when two members are joined with an adhesive, it is preferable to be able to easily determine the state of the joint.

[0006] The present invention has been made in consideration of the above problems, and has an object to make it possible to easily determine the bonding state. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention Claim 1 The joining member according to the present invention is A joining member in which a first member and a second member are joined with an adhesive, The first member has a first surface portion that is lower than a height of a joint surface with the second member, The second member is provided with a through hole that opens to face a part of the first surface portion and has a cross-sectional area smaller than an area of ​​the first surface portion. 、 The first member is provided with a second surface portion that is lower in height than the first surface portion, The second member is provided with a through hole that opens to face a part of the second surface portion and has a cross-sectional area smaller than an area of ​​the second surface portion. The composition was as follows. Effect of the Invention

[0008] According to the present invention, the bonding state can be easily determined. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of a liquid ejection head according to a first embodiment of the present invention; [Diagram 2] FIG. [Diagram 3] FIG. 4 is a cross-sectional explanatory view taken along the nozzle arrangement direction. [Figure 4] FIG. 4 is a cross-sectional explanatory view taken along a direction perpendicular to the nozzle arrangement direction. [Diagram 5] FIG. 4 is a cross-sectional view illustrating a joining member in the embodiment. [Figure 6] FIG. [Figure 7] 13 is an explanatory diagram illustrating the overflow of adhesive on the legs of the holding substrate; FIG. [Figure 8] FIG. 2 is a plan view illustrating an actuator substrate. [Figure 9] FIG. 4 is an explanatory plan view of the holding substrate as viewed from the bonding surface side. [Figure 10] FIG. 4 is a plan view illustrating a surface structure of the actuator substrate. [Figure 11] FIG. 11 is an explanatory cross-sectional view taken along line AA in FIG. [Figure 12] FIG. 4 is a plan view illustrating an opposing surface structure of a holding substrate. [Figure 13] FIG. 13 is an explanatory cross-sectional view taken along line CC in FIG. [Figure 14]13 is a cross-sectional explanatory view of a joining member corresponding to line AA in FIG. 10 and line BB in FIG. 12. [Figure 15] 13 is a cross-sectional view illustrating another example of a joined state of the joining members; FIG. [Figure 16] 13 is a cross-sectional view illustrating another example of a joined state of the joining members; FIG. [Figure 17] 13 is a cross-sectional view illustrating another example of a joined state of the joining members; FIG. [Figure 18] FIG. 2 is a cross-sectional explanatory view of Comparative Example 1. [Figure 19] 13 is a plan view illustrating a state in which an adhesive is applied to an opposing surface structure of a holding substrate in a bonding member according to a second embodiment of the present invention. FIG. [Figure 20] FIG. 20 is an explanatory cross-sectional view taken along line DD in FIG. 19. [Figure 21] 13 is a plan view illustrating a surface structure of an actuator substrate in a bonding member according to a third embodiment of the present invention. FIG. [Figure 22] FIG. [Figure 23] FIG. 11 is a cross-sectional explanatory view of a pressure chamber portion of a liquid ejection head according to a fourth embodiment of the present invention. [Figure 24] FIG. 11 is an explanatory cross-sectional view of a joining member according to a fifth embodiment of the present invention. [Diagram 25] 1 is a plan view illustrating a main portion of an example of a printing apparatus as a liquid ejecting apparatus according to the present invention; [Figure 26] FIG. [Figure 27] FIG. 13 is a plan view illustrating a main portion of another example of a liquid ejection unit according to the present invention. [Figure 28] FIG. 13 is a front view illustrating still another example of the liquid ejection unit according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. A liquid ejection head according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 4. Fig. 1 is a perspective view of the head, Fig. 2 is a plan view of the same, Fig. 3 is a cross-sectional view of the same along the nozzle arrangement direction, and Fig. 4 is a cross-sectional view of the same along a direction perpendicular to the nozzle arrangement direction.

[0011] The liquid ejection head 1 includes a nozzle plate 10, a flow path plate 20, a vibration plate member 30 which is a wall member, a piezoelectric element 40 which is a pressure generating element, a holding substrate (protection substrate, supply path substrate) 50, and the like.

[0012] Here, the portion consisting of the flow path plate 20, the vibration plate member 30 and the piezoelectric element 40 constitutes the actuator substrate 2.

[0013] A plurality of nozzles 11 for ejecting liquid are formed in the nozzle plate 10. Here, the nozzles 11 are arranged in two nozzle rows.

[0014] The flow path plate 20, together with the nozzle plate 10 and the vibration plate member 30, forms a pressure chamber 21 to which the nozzle 11 communicates, an individual supply flow path 22 that also serves as a fluid resistance portion communicating with the pressure chamber 21, and an intermediate supply flow path 23 that communicates with two or more individual supply flow paths 22.

[0015] This intermediate supply flow path 23 communicates with a common flow path formed by a common flow path member through an opening 39 in the vibration plate member 30 and an opening 51 provided in the holding substrate 50. The opening 51 in the holding substrate 50 may communicate with all of the intermediate supply flow paths 23 and form a part of the common flow path.

[0016] The vibration plate member 30 forms a deformable vibration region 31 that forms a part of the wall surface of the pressure chamber 21. A piezoelectric element 40 is provided integrally with the vibration region 31 on the surface of the vibration plate member 30 opposite to the pressure chamber 21.

[0017] The piezoelectric element 40 is configured by sequentially laminating a lower electrode 41, a piezoelectric layer (piezoelectric body) 42, and an upper electrode 43 from the vibration region 31 side. On this piezoelectric element 40, an insulating film 25 is formed.

[0018] The lower electrode 41, which serves as a common electrode for the multiple piezoelectric elements 40, is connected to a common electrode power supply wiring pattern. The lower electrode 41 is a single electrode layer formed across all the piezoelectric elements 40 in the nozzle arrangement direction.

[0019] Furthermore, the upper electrode 43 which becomes the individual electrode of the piezoelectric element 40 is connected to a driving IC (hereinafter referred to as a "driver IC") 500 which is a driving circuit section via individual wiring 46 and electrode pads 47. The individual wiring 46 and the like are covered with an insulating film 26.

[0020] A holding substrate 50 covering the piezoelectric elements 40 on the actuator substrate 2 is bonded to the diaphragm member 30 side of the actuator substrate 2 with an adhesive 114 .

[0021] The holding substrate 50 is provided with an opening 51 which is a part of the flow path connecting the common flow path and the pressure chamber 21, a recess 52 which houses the piezoelectric element 40, and an opening 53 which houses the driver IC 500. The opening 51 is a slit-shaped through hole which extends in the nozzle arrangement direction, and here constitutes a part of the common liquid chamber.

[0022] In this holding substrate 50 , the joint surfaces 59 of the legs 50 a between the recesses 52 , 52 for accommodating the piezoelectric elements 40 are joined to the joint surface 29 of the actuator substrate 2 by an adhesive 114 .

[0023] In this liquid ejection head 1, when a voltage is applied between the upper electrode 43 and the lower electrode 41 of the piezoelectric element 40 from the driver IC 500, the piezoelectric layer 42 expands in the electrode lamination direction, i.e., in the electric field direction, and contracts in a direction parallel to the vibration region 31. This generates a tensile stress on the lower electrode 41 side of the vibration region 31, causing the vibration region 31 to bend towards the pressure chamber 21, pressurizing the liquid inside, and causing the liquid to be ejected from the nozzle 11.

[0024] Next, a method for confirming the bonding state of the actuator substrate and the holding substrate that constitute the bonding member according to this embodiment and the bonding state will be described with reference to Fig. 5 to Fig. 7. Fig. 5 is a cross-sectional explanatory view of the bonding member, Fig. 6 is a planar explanatory view of the holding substrate, and Fig. 7 is an explanatory view for explaining the overflow of adhesive on the legs of the holding substrate.

[0025] The bonding member 100 is a member in which the actuator substrate 2 is bonded to the holding substrate 50, and in the following description, the actuator substrate 2 is referred to as a first member, and the holding substrate 50 is referred to as a second member.

[0026] The bonding member 100 is formed by bonding bonding surfaces 59, such as the leg parts 50a between the recesses 52, 52 provided on the holding substrate 50 and the wall parts 50b (see FIG. 4) on the recess 53 side and the opening 51 side, to the bonding surface 29 of the actuator substrate 2 with an adhesive 114. At this time, it is important that the amount of adhesive 114 is appropriate.

[0027] Therefore, it is necessary to check the bonding condition of the adhesive 114 that bonds the bonding surface 59 of the holding substrate 50 and the bonding surface 29 of the actuator substrate 2, such as whether or not there is excessive overflow of the adhesive 114 and whether or not there are any areas where the adhesive 114 is lacking.

[0028] This bonding state can be determined, for example, by looking at the fillet shape of the adhesive 114. However, the bonding portion between the leg portion 50a located between the piezoelectric elements 40, 40 of the holding substrate 50 and the opposing bonding surface 29 of the actuator substrate 2 cannot be seen from the outside due to the presence of the holding substrate 50.

[0029] The bonding state at such an invisible bonding portion can be observed, for example, by using an infrared microscope (IR microscope) to observe the bonding portion through the holding substrate 50. However, since the image observed by the IR microscope is unclear, it is not possible to confirm the fillet shape of the adhesive 114.

[0030] Furthermore, for example, when adhesive 114 migrates along the side wall surface of leg portion 50a as shown in FIG. 7, even if an attempt is made to observe the fillet shape of adhesive 114 through holding substrate 50 with an IR microscope, the fillet shape cannot be confirmed due to excess adhesive 114A that has migrated along the side wall surface.

[0031] In this way, it is not easy to use an IR microscope to check the fillet shape of the adhesive 114 between the bonding surface 59 of the leg 50a and the bonding surface 29 through the holding substrate 50 and determine the bonding condition.

[0032] Next, a configuration relating to monitoring the bonding state of the bonding member 100 in this embodiment will be described with reference to Fig. 8 to Fig. 13. Fig. 8 is an explanatory plan view of the actuator substrate, Fig. 9 is an explanatory plan view from the bonding surface side of the holding substrate, Fig. 10 is an explanatory plan view of the surface structure of the actuator substrate, and Fig. 11 is an explanatory cross-sectional view taken along line AA in Fig. 10. Fig. 12 is an explanatory plan view of the opposing surface structure of the holding substrate, Fig. 13 is an explanatory cross-sectional view taken along line CC in Fig. 12, and Fig. 14 is an explanatory cross-sectional view of the bonding member corresponding to line AA in Fig. 10 and line BB in Fig. 12.

[0033] As described above, the description will be given of the bonding member 100 in which the actuator substrate 2 is the first member and the holding substrate 50 is the second member. The actuator substrate 2 and the holding substrate 50 are, for example, produced by chamfering a plurality of silicon wafers, and are bonded at the wafer stage by applying adhesive 114 and then separated, but the present invention is not limited to this. Therefore, the description will be given here in units of the actuator substrate 2 and the holding substrate 50, and when multiple pieces are produced using a wafer, a note to that effect will be added.

[0034] The actuator substrate 2, which is a first member, is provided with a surface structure 115 on the surface side to which the bonding surface 59 of the holding substrate 50, which is a second member, is bonded with an adhesive 114. On the other hand, the holding substrate 50 is provided with an opposing surface structure 204 corresponding to the surface structure 115 of the actuator substrate 2, and a through hole 207 penetrating the opposing surface structure 204 is formed.

[0035] Here, the surface structure 115 of the actuator substrate 2 has a first surface 115a, a second surface 115b, a third surface 115c, a fourth surface 115d, and an enclosure 115e. The first surface 115a to the fourth surface 115 have surfaces facing the holding substrate 50 at different positions in the height direction.

[0036] The first surface portion 115a is lower than a bonding surface 29 between the actuator substrate 2 and the bonding surface 59 of the holding substrate 50. The second surface portion 115b is lower than the first surface portion 115a. The third surface portion 115c is lower than the first surface portion 115a and higher than the second surface portion 115b.

[0037] The fourth surface portion 115d is at the same height as the bonding surface 29 with the leg portion 50a of the holding substrate 50 of the actuator substrate 2. The surrounding portion 115e is also at the same height as the bonding surface 29.

[0038] For example, the height of the fourth surface portion 115d and the surrounding portion 115e is 4 μm (the same as the height of the bonding surface 29), the height of the first surface portion 115a is 3 μm, the height of the second surface portion 115b is 1 μm, and the height of the third surface portion 115c is 2 μm.

[0039] The arrangement order of the first to fourth surfaces 115a to 115d in this embodiment is not limited to that in this embodiment. Also, the first to fourth surfaces 115a to 115d are tip surfaces of independent protrusions, but the first to fourth surfaces 115a to 115d can be formed as an integrated protrusion if they have different heights.

[0040] Moreover, the surrounding portion 115e is a bonding surface, and is bonded to the surrounding portion 204e of the facing surface structure 204 of the holding substrate 50 by the adhesive 114. The height of the surrounding portion 115e is the same as the height of the fourth surface portion 115d, and can perform the same function as the fourth surface portion 115d.

[0041] The opposing surface structure 204 of the holding substrate 50 is configured with a first wide portion 204a to a fourth wide portion 204d, which are opposing surface portions facing the first surface portion 115a to the fourth surface portion 115d on the structure 115 of the actuator substrate 2, at the same height as a flat surface by the adhesive 114. The first wide portion 204a to the fourth wide portion 204d are at the same height as the bonding surface 59.

[0042] At least a part of the periphery of the first wide portion 204a to the fourth wide portion 204d is provided with a recess 204f that forms a portion lower in height than the first wide portion 204a to the fourth wide portion 204d.

[0043] In this embodiment, bridging portions 204g, which are narrowed portions, are provided between the wide portions 204a to 204d, between the first wide portion 204a and the surrounding portion 204e, and between the second wide portion 204b and the surrounding portion 204e to bridge the wide portions.

[0044] Furthermore, through holes 207 having openings facing the first surface portion 115a to the fourth surface portion 115d are formed in the first wide portion 204a to the fourth wide portion 204d of the holding substrate 50. The through holes 207 penetrate the holding substrate 50 including the facing surface structure 204 in the thickness direction.

[0045] In this embodiment, the adhesive 114 for bonding the actuator substrate 2 and the holding substrate 50 is applied by thin-film transfer onto the holding substrate 50, for example, by flexographic printing.

[0046] In the facing surface structure 204 of this embodiment, the first wide portion 204a to the fourth wide portion 204d, the bridging portion 204g, and the surrounding portion 204e other than the recess 204f all have the same height, and are provided with the adhesive 114. On the other hand, the adhesive 114 is not provided to the recess 204f and the through hole 207.

[0047] In this embodiment, the bridge portion 204g is provided in order to reinforce the first wide portion 204a to the fourth wide portion 204d. By providing the bridge portion 204g, the strength is improved compared to when the wide portion exists in isolation, and damage to the wide portion can be prevented when the adhesive 114 is thin-film-transferred by flexographic printing on a wafer-by-wafer basis.

[0048] In addition, in this embodiment, recesses 204f are formed around the first wide portion 204a to the fourth wide portion 204d so that when the actuator substrate 2 and the holding substrate 50 are bonded, excess adhesive 114 applied to the opposing surface structure 204 of the holding substrate 50 can escape into the recesses 204f.

[0049] The entire opposing surface structure 204 of the holding substrate 50 may be formed as a uniform flat surface without providing such a recess 204f. In this case, however, excess adhesive 114 may migrate in the surface direction toward the surface portions of the first surface portion 115a to the fourth surface portion 115d of the surface structure 115 of the actuator substrate 2 that the adhesive 114 would not normally come into contact with, which may result in the failure to accurately evaluate the adhesion state.

[0050] By providing the recess 204f as in this embodiment, it is possible to prevent such a situation from occurring, and it becomes possible to more accurately evaluate the joining state (bonding state).

[0051] Next, evaluation of the bonding state between the actuator substrate 2 and the holding substrate 50 will be described.

[0052] The actuator substrate 2 and the holding substrate 50 are joined with an adhesive 114, and an IR microscope 600 or the like can be used from the holding substrate 50 side to check whether the adhesive 114 has been applied to the first surface portion 115a to the fourth surface portion 115d of the actuator substrate 2.

[0053] In other words, by checking which of the first surface portion 115a to the fourth surface portion 115d are bonded (in contact) with the opposing surface structure 204 of the holding substrate 50 by the adhesive 114, it is possible to evaluate whether the bonding state is appropriate, for example, whether there is insufficient or excessive adhesive 114, or whether the bonding is appropriate.

[0054] In addition, if the holding substrate 50 is optically transparent to transmit infrared light, such as a silicon substrate, the holding substrate 50 can be used for observation.

[0055] 14, of the surface structure 115, the fourth surface portion 115d and the surrounding portion 115e, which are at the same height as the bonding surface 29 of the actuator substrate 2, are bonded with the fourth wide portion 204d and the surrounding portion 204e, which are at the same height as the bonding surface 59 of the facing surface structure 204, by the adhesive 114. Furthermore, the first surface portion 115a, which is lower than the fourth surface portion 115d and the surrounding portion 115e, is bonded with the first wide portion 204a by the adhesive 114.

[0056] On the other hand, the third surface portion 115c, which is the next lowest after the first surface portion 115a, is not joined to the third wide portion 204c by the adhesive 114, and the second surface portion 115b, which is the next lowest, is not joined to the second wide portion 204b by the adhesive 114. This makes it possible to confirm that at least a predetermined amount of squeezing ε (for example, 1 μm) is obtained.

[0057] The crushing amount ε here means the amount (crushed height) by which the adhesive 114 adhering to the surrounding portion 204e of the opposing surface structure 204 of the holding substrate 50 is crushed by the surrounding portion 115e of the surface structure 115 of the actuator substrate 2 when the actuator substrate 2 and the holding substrate 50 are joined.

[0058] The height of the surrounding portion 115e of the surface structure 115 of the actuator substrate 2 is the same as the height of the bonding surface 29 of the actuator substrate 2, and the height of the surrounding portion 204e of the opposing surface structure 204 of the holding substrate 50 is the same as the height of the bonding surface 59. Therefore, the squeezing amount ε corresponds to the squeezing amount ε of the adhesive 114 at the bonding portion between the bonding surface 29 and the bonding surface 59.

[0059] For example, when the target thickness of the adhesive 114 is set to 3 μm on average and the squeezing amount ε is 1 μm or more, it is evaluated that there is no gap between the bonding surface 29 of the actuator substrate 2 and the bonding surface 59 of the holding substrate 50, and there is no insufficient adhesion.

[0060] In this case, in the example of FIG. 14, as described above, at least the predetermined amount of squeezing ε (for example, 1 μm) is obtained, and therefore it is evaluated that there is no insufficient adhesion.

[0061] In other words, at least when the first surface portion 115a of the actuator substrate 2 is bonded to the holding substrate 50 side, which is the second member, with the adhesive 114, the bonding member 100 is not insufficient.

[0062] Here, in this embodiment, the first wide portion 204a to the fourth wide portion 204d of the opposing surface structure 204 of the holding substrate 50, which is the second member, are provided with through holes 207 that open into the first surface portion 115a to the fourth surface portion 115d of the actuator substrate 2, which is the first member.

[0063] As a result, when the actuator substrate 2 and the holding substrate 50 are bonded together, voids (air bubbles) in the adhesive 114 are released from the through holes 207, so that a clear image can be obtained when observing with the IR microscope 600. As a result, the reliability of checking the bonded state is improved.

[0064] That is, in a configuration in which no through-hole 207 is provided, such as in Comparative Example 1 shown in FIG. 18, the voids in the adhesive 114 are not eliminated, and therefore, when observed with the IR microscope 600, a clear image cannot be obtained.

[0065] Also, around the opening 39 of the diaphragm member 30 which actually needs to be sealed, voids in the adhesive 114 can escape due to the opening 39, and when the sealing state is checked with an infrared microscope, a clear image without voids can be obtained. By making the structure of the part which actually needs to be sealed the same as the structure of the bonding monitor, a clearer image can be obtained, and the inspection reliability can be improved.

[0066] Depending on the type of adhesive 114, it may become wavy after being applied to the holding substrate 50. For example, even if the thickness of the adhesive 114 is 3 μm on average, the thickness may vary within a range of 2.5 μm to 3.5 μm. Even in such a case, if a squashing amount of 1 μm or more is obtained, a squashing amount of 0.5 μm or more is ensured even at the part where the adhesive 114 has the thinnest thickness of 2.5 μm, and a state of insufficient adhesion can be avoided. Even if air bubbles are trapped in the wavy part, the air bubbles are discharged from the through hole, making it possible to clearly determine the adhesion state. The threshold value of the squashing amount ε is set according to the type of adhesive, the method of applying the adhesive, etc.

[0067] Next, other examples of the bonding state of the bonding member will be described with reference to Fig. 15 to Fig. 17. Fig. 15 to Fig. 17 are cross-sectional explanatory views similar to Fig. 14, which are provided for explaining evaluation of the bonding state between the actuator substrate 2 and the holding substrate 50.

[0068] In the bonding state shown in Figure 15, the fourth surface portion 115d and surrounding portion 115e of the surface structure 115 of the actuator substrate 2, which are at the same height as the bonding surface 29 of the actuator substrate 2, are bonded to the fourth wide portion 204d and surrounding portion 204e, which are at the same height as the bonding surface 59 of the opposing surface structure 204, with adhesive 114.

[0069] Furthermore, the first surface portion 115a, which is lower than the fourth surface portion 115d and the surrounding portion 115e, is joined to the first wide portion 204a with the adhesive 114, and the third surface portion 115c, which is the next lowest after the first surface portion 115a, is also joined to the third wide portion 204c with the adhesive 114. However, the second surface portion 115b, which is the next lowest after the third surface portion 115c, is not joined to the second wide portion 204b with the adhesive 114.

[0070] Therefore, such a bonding state can be evaluated as being, for example, good.

[0071] In contrast, in the bonding state shown in Figure 16, the fourth surface portion 115d and surrounding portion 115e of the surface structure 115 of the actuator substrate 2, which are at the same height as the bonding surface 29 of the actuator substrate 2, are bonded to the fourth wide portion 204d and surrounding portion 204e, which are at the same height as the bonding surface 59 of the opposing surface structure 204, with adhesive 114.

[0072] However, none of the first to third surface portions 115a to 115c, which are lower than the fourth surface portion 115d and the surrounding portion 115e, are joined by the adhesive 114 to the first to third wide portions 204a to 204c.

[0073] Therefore, such a bonding state can be evaluated as being defective due to a lack of adhesive.

[0074] In addition, in the bonding state shown in FIG. 17, the first surface portion 115a to the fourth surface portion 115d and the surrounding portion 115e of the surface structure 115 of the actuator substrate 2 are all bonded to the first wide portion 204a to the fourth wide portion 204d and the surrounding portion 204e with the adhesive 114.

[0075] Therefore, such a bond can be evaluated as being poor because there is too much adhesive.

[0076] Next, a bonding member according to a second embodiment of the present invention will be described with reference to Fig. 19 and Fig. 20. Fig. 19 is a plan view of the state in which an adhesive is applied to the facing surface structure of the holding substrate in the second embodiment, and Fig. 20 is a cross-sectional view taken along line DD in Fig. 19.

[0077] In this embodiment, the opposing surface portion structure 204 of the holding substrate has one opposing surface 204 h that is at the same height as the bonding surface 59 .

[0078] When the adhesive 114 is applied to the opposing surface 204h of the opposing surface structure 204, it is patterned into the first shape portion 114a to the fourth shape portion 114d, the surrounding portion 114e, and the bridge shape portion 114g, which have approximately the same shapes as the first surface portion 115a to the fourth surface portion 115d and surrounding portion 115e of the surface structure 115 of the actuator substrate 2.

[0079] As a result, even if the recess 204f in the first embodiment described above is not provided, the adhesive 114 will not be directed toward any of the four first to fourth surface portions 115a to 115d in the surface structure 115 of the actuator substrate 2 that it would not normally come into contact with.

[0080] Therefore, there is no risk of the adhesive overflowing, which can occur when applying adhesive in flexographic printing, making it impossible to accurately evaluate the bonding condition.

[0081] Next, a bonding member according to a third embodiment of the present invention will be described with reference to Fig. 21 and Fig. 22. Fig. 21 is a plan view of a surface structure of an actuator substrate in this embodiment, and Fig. 22 is a cross-sectional view of the surface structure.

[0082] In this embodiment, the surface structure 115 of the actuator substrate 2 is made of the same material as the other components of the actuator substrate 2. This allows the first surface 115a to the fourth surface 115d and the surrounding portion 115e of the surface structure 115 to be easily formed in the film formation process for forming the piezoelectric elements and the like of the actuator substrate 2.

[0083] In this embodiment, the vibration plate member 30 has a three-layer structure of a SiO2 film 30a, a Si layer 30b, and a SiO2 film 30c from the flow path plate 20 side. The insulating film 25 has a two-layer structure of an Al2O3 film 25a and a SiN film 25b. The wiring film 46A is a single layer of Al. The insulating film 26 is a single layer of SiN.

[0084] The fourth surface portion 115d and the surrounding portion 115e are structures in which the diaphragm member 30, the insulating film 25 having a two-layer structure, the wiring film 46A of the lead-out wiring 46, and the insulating film 26 are laminated.

[0085] The second surface portion 115b is a laminated structure of the SiO2 film 30a and the Si layer 30b of the three-layered diaphragm member 30. The second surface portion 115b is lower in height than the fourth surface portion 115d and the surrounding portion 115e by the layer thickness of the SiO2 film 30c, the insulating film 25, the wiring film 46A, and the insulating film 26 of the diaphragm member 30.

[0086] The first surface portion 115a is a structure in which the diaphragm member 30, the insulating film 25, and the wiring film 46A are laminated together. The first surface portion 115a is lower in height than the fourth surface portion 115d and the surrounding portion 115e by the layer thickness of the insulating film 26.

[0087] The third surface portion 115c is a structure in which the diaphragm member 30, the insulating film 25, and the insulating film 26 are laminated. The third surface portion 115c is lower in height than the fourth surface portion 115d and the surrounding portion 115e by the layer thickness of the insulating film 22 and a part of the wiring film 46A.

[0088] In this embodiment, the first to fourth surface portions 115a to 115d and the surrounding portion 115e are bridged together by bridge portions 115g.

[0089] Next, a liquid ejection head according to a fourth embodiment of the present invention will be described with reference to Fig. 23. Fig. 23 is a cross-sectional explanatory view of a pressure chamber portion of the head.

[0090] In this embodiment, the lower electrode 41 constituting the piezoelectric element 40 is an individual electrode, and the upper electrode 43 is a common electrode.

[0091] Next, a joining member according to a fifth embodiment of the present invention will be described with reference to Fig. 24. Fig. 24 is a cross-sectional explanatory view of the joining member according to this embodiment.

[0092] In this embodiment, the surrounding portion 204 a constituting the facing surface structure 204 of the holding substrate 50 is also provided with a through hole 207 .

[0093] This allows voids in the adhesive 114 that bonds the enclosure 204 to escape.

[0094] In the above-described embodiments, the bonding member is a member that bonds the actuator substrate and the holding substrate of the liquid ejection head. However, the bonding member may be a member other than the liquid ejection head.

[0095] Next, an example of a printing apparatus as an apparatus for discharging liquid according to the present invention will be described with reference to Figures 25 and 26. Figure 25 is an explanatory plan view of the main parts of the apparatus, and Figure 26 is an explanatory side view of the main parts of the apparatus.

[0096] This printing device 400 is a serial type device, and a carriage 403 is reciprocated in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B to movably hold the carriage 403. The carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0097] A liquid ejection unit 440 is mounted on this carriage 403, which integrates a liquid ejection head 1 according to the present invention and a head tank 441. The head 1 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 1 is mounted with a nozzle row made up of a plurality of nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward.

[0098] The printing apparatus 400 includes a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412.

[0099] The conveyor belt 412 attracts the paper 410 and conveys it to a position facing the head 1. The conveyor belt 412 is an endless belt, and is stretched between a conveyor roller 413 and a tension roller 414. The paper can be attracted by electrostatic attraction or air suction.

[0100] The conveyor belt 412 moves in a circular motion in the sub-scanning direction as the conveyor rollers 413 are rotated by a sub-scanning motor 416 via a timing belt 417 and a timing pulley 418 .

[0101] Furthermore, a maintenance and recovery mechanism 420 for performing maintenance and recovery of the liquid ejection head 1 is disposed on one side of the conveyor belt 412 on one side of the carriage 403 in the main scanning direction.

[0102] The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 that caps the nozzle surface of the head 1, a wiper member 422 that wipes the nozzle surface, and the like.

[0103] The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

[0104] In the printing device 400 configured in this manner, a sheet of paper 410 is fed onto and adsorbed to the conveyor belt 412, and the sheet of paper 410 is conveyed in the sub-scanning direction by the rotation of the conveyor belt 412.

[0105] Therefore, by driving the head 1 in response to an image signal while moving the carriage 403 in the main scanning direction, liquid is discharged onto the stationary paper 410 to form an image. do.

[0106] Next, another example of a liquid discharge unit according to the present invention will be described with reference to Fig. 27. Fig. 27 is an explanatory plan view of the main part of the unit.

[0107] This liquid ejection unit 440 is made up of, among the members constituting the device that ejects the liquid, a housing portion made up of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a head 1.

[0108] It is also possible to configure a liquid discharge unit in which the above-mentioned maintenance and recovery mechanism 420 is further attached to, for example, the side plate 491B of this liquid discharge unit 440.

[0109] Next, still another example of a liquid discharge unit according to the present invention will be described with reference to Fig. 28. Fig. 28 is an explanatory front view of the unit.

[0110] This liquid discharge unit 440 is composed of a head 1 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444 .

[0111] The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. Furthermore, a connector 443 for electrically connecting with the liquid ejection head 1 is provided on the upper part of the flow path part 444.

[0112] In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but it is preferable that the viscosity of the liquid is 30 mPa·s or less at room temperature and pressure, or by heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, etc., containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural colorant, etc., and these can be used for applications such as inkjet ink, surface treatment liquid, a liquid for forming a component of an electronic element or a light-emitting element, an electronic circuit resist pattern, a material liquid for three-dimensional modeling, etc.

[0113] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0114] A "liquid ejection unit" is a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to ejecting liquid. For example, a "liquid ejection unit" includes a combination of a liquid ejection head and at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0115] Here, integration includes, for example, a liquid ejection head, a functional part, and a mechanism that are fixed to each other by fastening, bonding, engaging, etc., and one is held movably relative to the other. Also, the liquid ejection head, the functional part, and the mechanism may be configured to be detachable from each other.

[0116] For example, there are liquid ejection units in which the liquid ejection head and the head tank are integrated together, and there are also liquid ejection units in which the liquid ejection head and the head tank are integrated together by being connected to each other by a tube, etc. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

[0117] Furthermore, there is a liquid ejection unit in which the liquid ejection head and the carriage are integrated.

[0118] In some liquid ejection units, the liquid ejection head is movably supported by a guide member that constitutes a part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together, and in some liquid ejection units, the liquid ejection head, the carriage, and the main scanning movement mechanism are integrated together.

[0119] Furthermore, there is a liquid ejection unit in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which the liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

[0120] In addition, some liquid ejection units have a head tank or a liquid ejection head to which a flow path component is attached, and a tube is connected to the liquid ejection head, integrating the liquid ejection head with a supply mechanism. Liquid is supplied from a liquid storage source to the liquid ejection head via this tube.

[0121] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0122] Note that, here, the "liquid ejection unit" is described in combination with a liquid ejection head, but the "liquid ejection unit" also includes a head module or head unit including the liquid ejection head described above, which is integrated with the functional components and mechanisms described above.

[0123] "Liquid ejection devices" include devices that are equipped with a liquid ejection head, a liquid ejection unit, a head module, a head unit, etc., and eject liquid by driving the liquid ejection head. Liquid ejection devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0124] This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0125] For example, examples of "devices that eject liquid" include image forming devices that eject ink to form an image on paper, and three-dimensional modeling devices that eject modeling liquid onto a powder layer formed by layering powder in order to create a three-dimensional object (a three-dimensional model).

[0126] In addition, the term "liquid ejection device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves and devices that create three-dimensional images.

[0127] The above-mentioned "object to which liquid can adhere" means an object to which liquid can adhere at least temporarily, and to which the liquid adheres and sticks, or to which the liquid adheres and penetrates, etc. Specific examples include media such as paper, recording paper, film, cloth, and other recording media, electronic boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects to which liquid can adhere.

[0128] The material of the above-mentioned "object to which liquid can adhere" may be any material to which liquid can adhere even temporarily, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, and ceramics.

[0129] Furthermore, the "liquid ejection device" may be a device in which a liquid ejection head and an object to which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which a liquid ejection head moves, a line type device in which a liquid ejection head does not move, etc.

[0130] Other examples of "liquid ejecting devices" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that ejects a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0131] In the present application, the terms image formation, recording, printing, imprinting, printing, modeling, and the like are all synonymous. [Explanation of symbols]

[0132] 1 Liquid ejection head 2 Actuator substrate (first member) 10 Nozzle plate 11 Nozzle 20 Flow path plate 21 Pressure Chamber 29 Joint surface 30 Diaphragm member 50 holding substrate (second member) 59 Joint surface 100 Joint material 114 Adhesive 115 Surface structure 115a to 115d: first surface portion to fourth surface portion 204 Opposing surface structure 204a to 204d 1st wide section to 4th wide section 207 Through Hole 400 Printing device (device that ejects liquid) 403 Carriage 440 Liquid Dispensing Unit

Claims

1. A joining member in which a first member and a second member are joined with an adhesive, The first member has a first surface portion that is lower than a height of a joint surface with the second member, The second member has a through hole that opens to face a part of the first surface portion and has a cross-sectional area smaller than an area of ​​the first surface portion. The first member is provided with a second surface portion that is lower in height than the first surface portion, The second member is provided with a through hole that opens to face a part of the second surface portion and has a cross-sectional area smaller than an area of ​​the second surface portion. A joining member characterized by:

2. The first member has a third surface portion that is lower than the first surface portion and higher than the second surface portion. The joining member according to claim 1 .

3. The first member has a fourth surface portion having the same height as the joint surface with the second member.

3. The joining member according to claim 1 or 2.

4. A joining member in which a first member and a second member are joined with an adhesive, The first member has a first surface portion that is lower than a height of a joint surface with the second member, The second member has a through hole that opens to face a part of the first surface portion and has a cross-sectional area smaller than an area of ​​the first surface portion. The second member has an opposing surface portion to which the adhesive is applied and which faces the surface portion of the first member. A joining member characterized by:

5. The opposing surface of the second member is at the same height as the joint surface with the first member. The joining member according to claim 4 .

6. the second member has opposing surface portions corresponding to the respective surface portions of the first member, The opposing surfaces are bridged to each other by a bridge portion. The joining member according to claim 4 or 5.

7. The second member has a portion that is lower than the opposing surface portion on at least a part of the periphery of the opposing surface portion.

7. The joining member according to claim 4, wherein the joining member is made of a material selected from the group consisting of tungsten, ... and zinc.

8. The joining member according to any one of claims 1 to 7 is included. A liquid ejection head comprising:

9. A liquid ejection unit comprising the liquid ejection head according to claim 8.

10. 10. A liquid ejection device comprising: a liquid ejection head according to claim 8; or a liquid ejection unit according to claim 9.

Images