Method for manufacturing nozzle plate, liquid ejecting head, and liquid ejecting apparatus

Abstract

The invention provides a nozzle plate manufacturing method, a liquid ejecting head, and a liquid ejecting apparatus. This method for manufacturing a nozzle plate is provided with: a first step for preparing a substrate, which is a member in which a first nozzle layer comprising silicon, an intermediate layer comprising silicon oxide, and a second nozzle layer comprising silicon are laminated in this order, and in which a space is provided in a portion of the intermediate layer; a second step in which, after the first step, a Bosch process is performed on a first region in which at least a part of the first nozzle layer overlaps the space, thereby providing a first nozzle opening communicating with the space; and a third step in which a Bosch process is performed on a second region in which at least a part of the second nozzle layer overlaps the space portion, thereby providing a second nozzle opening that communicates with the space portion and has a larger diameter than the first nozzle opening.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a nozzle plate having a nozzle for ejecting a liquid, a liquid ejecting head for ejecting a liquid, and a liquid ejecting device including the liquid ejecting head. Background Art

[0002] A liquid ejecting device typified by an inkjet recording device such as an inkjet printer includes a liquid ejecting head capable of ejecting a liquid such as ink stored in a cartridge or a tank in the form of droplets.

[0003] The liquid ejecting head includes a nozzle plate provided with nozzles for ejecting droplets. The nozzle is a member having a first nozzle opening provided on the ejection surface side and a second nozzle opening communicating with the first nozzle opening and having a larger diameter than the first nozzle opening. In order to set the ejection characteristics of the droplets ejected from such a nozzle, such as the ejection speed or the weight of the droplets, to a target value, it is necessary to form the length of the first nozzle opening without error. However, in the case of forming the first nozzle opening by ordinary etching, although the length of the first nozzle opening is adjusted by adjusting the etching time, an error is caused due to time control. Therefore, a nozzle plate using an SOI substrate formed by sandwiching an insulating film such as silicon oxide between two silicon substrates has been proposed (for example, refer to Patent Document 1).

[0004] However, there are problems such as when an SOI substrate is used for the nozzle plate and the first nozzle opening is formed by ordinary etching, when the insulating film functions as an etching stop layer, ions are bent due to the charging of the insulating film, and a part of the side wall of the first nozzle opening on the insulating film side is etched widely, so-called notching occurs, and thus the desired shape cannot be obtained for the first nozzle opening, and the desired ejection characteristics cannot be obtained.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-51833. Summary of the Invention

[0006] A method for manufacturing a nozzle plate according to the present invention for solving the above problems is a method for manufacturing a nozzle plate provided with nozzles to be mounted on a liquid ejection head, and includes the following steps: a first step of preparing a substrate in which a first nozzle layer made of silicon, an intermediate layer made of silicon oxide, and a second nozzle layer made of silicon are laminated in this order, and a space portion is provided in a part of the intermediate layer; a second step of, after the first step, performing a Bosch process on a first region where at least a part of the first nozzle layer overlaps with the space portion, thereby providing a first nozzle opening communicating with the space portion; and a third step of performing a Bosch process on a second region where at least a part of the second nozzle layer overlaps with the space portion, thereby providing a second nozzle opening communicating with the space portion and having a larger diameter than the first nozzle opening.

[0007] Another aspect of the present invention is a liquid ejection head, characterized by having: a nozzle plate provided with nozzles; a pressure chamber substrate provided with a pressure chamber for applying pressure to a liquid for ejecting the liquid from the nozzles. In the liquid ejection head, a first nozzle layer made of silicon, an intermediate layer made of silicon oxide, and a second nozzle layer made of silicon are laminated on the nozzle plate in this order. In the first nozzle layer, a first nozzle opening is provided. In the intermediate layer, a space portion communicating with the first nozzle opening is provided. In the second nozzle layer, a second nozzle opening communicating with the space portion and having a larger diameter than the first nozzle opening is provided. Sector-shaped notches are respectively formed at the first nozzle opening and the second nozzle opening, and no sector-shaped notch is formed at the space portion.

[0008] Furthermore, another aspect of the present invention is a liquid ejection device, characterized by including the liquid ejection head described in the above aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A diagram showing a schematic configuration of the liquid ejection device according to Embodiment 1.

[0010] Figure 2 An exploded perspective view of the liquid ejection head according to Embodiment 1.

[0011] Figure 3 A top view of the main part of the liquid ejection head according to Embodiment 1.

[0012] Figure 4 A cross-sectional view of the main part of the liquid ejection head according to Embodiment 1.

[0013] Figure 5 A cross-sectional view of the main part of the nozzle plate according to Embodiment 1, which is enlarged.

[0014] Figure 6 It is a partially enlarged cross-sectional view showing a modified example of the nozzle plate according to Embodiment 1.

[0015] Figure 7 It is a partially enlarged cross-sectional view showing a modified example of the nozzle plate according to Embodiment 1.

[0016] Figure 8 It is a partially enlarged cross-sectional view showing a modified example of the nozzle plate according to Embodiment 1.

[0017] Figure 9 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0018] Figure 10 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0019] Figure 11 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0020] Figure 12 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0021] Figure 13 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0022] Figure 14 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0023] Figure 15 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 1.

[0024] Figure 16 It is a cross-sectional view with the main part of the nozzle plate according to Embodiment 2 enlarged.

[0025] Figure 17 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 2.

[0026] Figure 18 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 2.

[0027] Figure 19 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 2.

[0028] Figure 20 It is a cross-sectional view showing a manufacturing method of the nozzle plate according to Embodiment 2. Detailed implementation manners

[0029] The present invention will be described in detail below based on embodiments. However, the following description represents the content of one mode of the present invention and can be arbitrarily changed within the scope of the present invention. Components denoted by the same reference numerals in the respective drawings represent the same components, and the description is appropriately omitted. In addition, in each drawing, X, Y, and Z represent three mutually orthogonal spatial axes. In this specification, the directions along these axes are set as the X direction, the Y direction, and the Z direction. The direction toward which the arrow mark in each drawing points is set as the positive (+) direction, and the direction opposite to the arrow mark is set as the negative (-) direction for description. Further, the Z direction represents the vertical direction, the +Z direction represents vertically downward, and the -Z direction represents vertically upward. Furthermore, for the directions of the three spatial axes for which the positive and negative directions are not defined, they are described as the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0030] Embodiment 1

[0031] Figure 1 FIG. is a diagram showing a schematic configuration of a liquid ejection device 1 according to Embodiment 1 of the present invention.

[0032] As Figure 1 shown, the liquid ejection device 1 is a so-called serial printer that includes a liquid ejection head H, conveys a medium S in the X-axis direction, and performs printing by ejecting liquid from the liquid ejection head H toward the medium S in the +Z direction while reciprocating the liquid ejection head H in the Y-axis direction. In addition, as the medium S, in addition to cloth, any material such as recording paper or resin film can be used. Furthermore, the direction in which the liquid ejection head H reciprocates is not limited to the Y-axis direction and may be a direction inclined with respect to both the X-axis direction and the Y-axis direction.

[0033] Such a liquid ejection device 1 includes a liquid ejection head H, a liquid storage unit 3, a control unit 4 as a control unit, a conveyance mechanism 5 that sends out the medium S, and a moving mechanism 6.

[0034] The liquid ejection head H ejects the liquid supplied from the liquid storage unit 3 that stores the liquid in the form of droplets in the +Z direction.

[0035] The liquid storage unit 3 stores a plurality of types of liquids having different colors or components ejected from the liquid ejection head H separately. As the liquid storage unit 3, for example, a cartridge that can be detached and attached to the liquid ejection device 1, a bag-shaped ink bag formed of a flexible film, an ink tank that can replenish ink, etc. can be cited. In addition, in Figure 1A liquid reservoir 3 is illustrated. Incidentally, the liquid reservoir 3 can be either a liquid reservoir 3 with partitioned chambers that stores multiple types of liquids separately, or multiple liquid reservoirs 3 that are separately provided according to multiple types of liquids. In addition, the liquid reservoir 3 can also be divided into a main tank and a sub-tank. It can also have the following structure: the sub-tank is connected to the liquid ejection head H, and the liquid consumed by ejecting droplets from the liquid ejection head H is replenished from the main tank to the sub-tank.

[0036] The control unit 4 comprehensively controls each element of the liquid ejection device 1, that is, the liquid ejection head H, the conveyance mechanism 5, the moving mechanism 6, etc.

[0037] The conveyance mechanism 5 is a component that conveys the medium S in the X-axis direction and has conveyance rollers 5a. The conveyance mechanism 5 rotates the conveyance rollers 5a to convey the medium S in the X-axis direction. The conveyance rollers 5a are rotated by the drive of a conveyance motor (not shown). The control unit 4 controls the conveyance of the medium S by controlling the drive of the medium conveyance motor. In addition, the conveyance mechanism 5 for conveying the medium S is not limited to the mechanism having the conveyance rollers 5a. For example, it can also be a mechanism that conveys the medium S by a belt or a roller.

[0038] The moving mechanism 6 is a mechanism for reciprocating the liquid ejection head H in the Y-axis direction and includes a holding body 7 and a conveyor belt 8. The holding body 7 is a so-called carriage that holds the liquid ejection head H and is fixed to the conveyor belt 8. The conveyor belt 8 is a seamless belt stretched along the Y-axis direction. The conveyor belt 8 is rotated by the drive of a conveyor motor (not shown). The control unit 4 controls the drive of the conveyor motor to rotate the conveyor belt 8, and further reciprocates the liquid ejection head H together with the holding body 7 in the Y-axis direction. In addition, the holding body 7 can also be structured to carry the liquid reservoir 3 together with the liquid ejection head H.

[0039] Under the control implemented by the control unit 4, the liquid ejection head H performs an ejection action of ejecting the liquid supplied from the liquid reservoir 3 in the form of droplets from each of the multiple nozzles 25 (refer to Figure 2 ) in the +Z direction. By performing the ejection action implemented by this liquid ejection head H in parallel with the conveyance of the medium S implemented by the conveyance mechanism 5 and the reciprocating movement of the liquid ejection head H implemented by the moving mechanism 6, so-called printing in which the liquid is applied to the medium S is performed.

[0040] Figure 2 is an exploded perspective view of the liquid ejection head H. Figure 3 is a top view of the pressure chamber substrate 10 in a state of being assembled in the liquid ejection head H. Figure 4 is with Figure 3A cross-sectional view of the liquid ejecting head H with line AA′ as a reference. Figure 5 For, magnified Figure 4 In addition, each direction of the liquid ejecting head H is described based on the direction when it is mounted on the liquid ejecting device 1, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0041] As shown in the figure, the liquid ejecting head H of this embodiment includes a pressure chamber substrate 10 , a communication plate 15 , a nozzle plate 20 having a plurality of nozzles 25 formed therein, a protective substrate 30 , a case member 40 , a piezoelectric actuator 300 , and a wiring member 110 .

[0042] The pressure chamber substrate 10 is composed of, for example, a silicon substrate, a glass substrate, an SOI (silicon on insulator) substrate, various ceramic substrates, etc. In the pressure chamber substrate 10, a plurality of pressure chambers 12 are arranged side by side along the X-axis direction. A plurality of pressure chambers 12 are arranged on a straight line along the X-axis direction in a manner that they are located at the same position with respect to the Y-axis direction. Two pressure chambers 12 adjacent to each other in the X-axis direction are divided by a partition wall not shown. In addition, in the present embodiment, the pressure chamber columns in which the pressure chambers 12 are arranged side by side along the X-axis direction are arranged in two columns in the Y-axis direction. Of course, the configuration of the pressure chambers 12 is not particularly limited thereto. For example, a plurality of pressure chambers 12 may also be arranged in a staggered manner along the X-axis direction. Here, the so-called configuration of the pressure chambers 12 in a staggered manner along the X-axis direction refers to the situation where the pressure chambers 12 arranged side by side in the X-axis direction are alternately staggered in the Y-axis direction. That is, the pressure chambers 12 are arranged in two rows in the Y-axis direction, and the two pressure chamber rows are staggered in the X-axis direction by half the pitch of the pressure chambers 12, so-called half pitch.

[0043] The communication plate 15 and the nozzle plate 20 are sequentially stacked on the surface of the pressure chamber substrate 10 facing the +Z direction. The vibration plate 50 and the piezoelectric actuator 300 are sequentially stacked on the surface of the pressure chamber substrate 10 facing the -Z direction.

[0044] The communication plate 15 is composed of a plate-like member joined to the surface of the pressure chamber substrate 10 facing the +Z direction. In the communication plate 15, a nozzle communication passage 16 that connects the pressure chamber 12 and the nozzle 25 is provided. Further, in the communication plate 15, a first manifold portion 17 and a second manifold portion 18 that form a part of a manifold 100 that serves as a common liquid chamber for commonly connecting a plurality of pressure chambers 12 are provided. The first manifold portion 17 is provided so as to penetrate the communication plate 15 in the Z-axis direction. In addition, the second manifold portion 18 is provided so as not to penetrate the communication plate 15 in the Z-axis direction but to open on the surface facing the +Z direction. Further, in the communication plate 15, a supply communication passage 19 that communicates with one end of the pressure chamber 12 in the Y-axis direction is independently provided for each pressure chamber 12. The supply communication passage 19 connects the second manifold portion 18 and the pressure chamber 12, thereby supplying the ink in the manifold 100 to the pressure chamber 12. As such a communication plate 15, a metal substrate such as a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, or a stainless steel substrate can be used. Preferably, the communication plate 15 uses a material having a coefficient of linear expansion equivalent to that of the substrates joined to the communication plate 15, that is, the pressure chamber substrate 10 and the nozzle plate 20, such as a silicon substrate or an SOI substrate. By using a material having a coefficient of linear expansion equivalent to that of the substrates joined to the communication plate 15 for the communication plate 15, it is possible to suppress the occurrence of peeling or cracks caused by warping due to the difference in the coefficients of linear expansion of the two.

[0045] The nozzle plate 20 is joined to the surface of the communication plate 15 opposite to the pressure chamber substrate 10, that is, the surface facing the +Z direction. On the nozzle plate 20, a plurality of nozzles 25 that communicate with the respective pressure chambers 12 via the nozzle communication passage 16 are formed. In the present embodiment, the plurality of nozzles 25 are arranged and disposed in a row along the X-axis direction. Further, in the present embodiment, two rows of nozzle rows in which the nozzles 25 are arranged side by side along the X-axis direction are separately provided in the Y-axis direction. Such a nozzle plate 20 is composed of an SOI substrate.

[0046] As Figure 5 shown, the nozzle plate 20 includes a first nozzle layer 21 formed of silicon, an intermediate layer 22 formed of silicon oxide such as silicon dioxide (SiO2), and a second nozzle layer 23 formed of silicon. The first nozzle layer 21, the intermediate layer 22, and the second nozzle layer 23 are laminated in this order in the -Z direction.

[0047] The thickness of the first nozzle layer 21 in the Z-axis direction is thinner than the thickness of the second nozzle layer 23, and the thickness of the intermediate layer 22 in the Z-axis direction is thinner than the thickness of the first nozzle layer 21. That is, the thickness in the Z-axis direction increases in the order of the intermediate layer 22, the first nozzle layer 21, and the second nozzle layer 23.

[0048] The nozzle 25 is a component that sprays ink droplets toward the +Z direction, and includes a first nozzle opening 26 formed on the first nozzle layer 21, a space portion 27 formed on the intermediate layer 22, and a second nozzle opening 28 formed on the second nozzle layer 23. These first nozzle opening 26, space portion 27, and second nozzle opening 28 are arranged and configured in the -Z direction in this order.

[0049] On the side walls of the first nozzle opening 26 and the second nozzle opening 28, sector-shaped notches (scallops) 26a and 28a are respectively formed. Here, the so-called sector-shaped notches 26a and 28a are shapes in which, when a through-hole or a recess is formed on a silicon substrate by the Bosch Process, waveforms as seen on the surface of a shell, that is, shapes in which a plurality of recesses are formed, are formed on the side walls of the through-hole or the recess. In addition, the Bosch Process is a method of forming a substantially vertical through-hole by alternately repeating etching and coating.

[0050] In addition, on the space portion 27, no sector-shaped notch is formed. That is, the side wall surface of the space portion 27 becomes a flat surface along the Z-axis direction.

[0051] The inner diameter d2 of such a second nozzle opening 28 is larger than the inner diameter d1 of the first nozzle opening 26. That is, the inner diameter d1 of the first nozzle opening 26 and the inner diameter d2 of the second nozzle opening 28 satisfy the relationship d1 < d2. Here, the so-called inner diameter of the first nozzle opening 26 is the smallest inner diameter of the first nozzle opening 26. For example, when the inner diameter of the first nozzle opening 26 is different on the intermediate layer 22 side and the side opposite to the intermediate layer 22, that is, when the first nozzle opening 26 gradually narrows from the intermediate layer 22 side toward the side opposite to the intermediate layer 22, the inner diameter of the first nozzle opening 26 refers to the inner diameter of the portion on the side opposite to the intermediate layer 22. In addition, although a sector-shaped notch is formed on the side wall of the first nozzle opening 26, the inner diameter of the first nozzle opening 26 refers to the inner diameter of the portion that is the smallest due to the sector-shaped notch. In addition, the inner diameter of the first nozzle opening 26 can be the maximum inner diameter, and can also be the average value of the inner diameters measured at several positions in the depth direction, etc. The same applies to the inner diameter d2 of the second nozzle opening 28 as to the inner diameter d1 of the first nozzle opening 26.

[0052] The inner diameter d3 of the space portion 27 is larger than the inner diameter d1 of the first nozzle opening 26 and smaller than the inner diameter d2 of the second nozzle opening 28. That is, the inner diameter d1 of the first nozzle opening 26, the inner diameter d2 of the second nozzle opening 28, and the inner diameter d3 of the space portion 27 satisfy the relationship of d1 < d3 < d2. In this way, for the nozzle 25, the inner diameter gradually decreases in the order of the second nozzle opening 28, the space portion 27, and the first nozzle opening 26 along the flow direction of the ink, so that the inner diameter decreases stepwise toward the flow direction of the ink, and thus it is possible to suppress the formation of bubbles in the nozzle 25 or the situation where the ink stays. Therefore, it is possible to suppress the following situation, that is, due to the retention of bubbles in the nozzle 25, the ejection position of the ink droplets onto the medium S is shifted due to the bending of the ejection direction of the ink droplets, or ejection defects such as the ink droplets not being ejected occur.

[0053] In addition, the second nozzle layer 23 has a groove 29 that opens on the wall surface of the second nozzle opening 28 at the interface with the intermediate layer 22. Although the detailed situation of this groove 29 will be described later, it is formed by the grooving generated when the second nozzle opening 28 is formed by etching on the second nozzle layer 23. Here, the so-called grooving means that when a through hole is formed by etching from one surface side of the silicon substrate, by making the insulating film provided on the other surface side of the silicon substrate function as an etching stop layer, the insulating film is charged, and the ions used in the etching are bent, and then a part of the side wall of the through hole on the insulating film side is etched widely to form a groove.

[0054] In addition, although in the present embodiment, it is assumed that the second nozzle layer 23 has the groove 29, grooving does not necessarily occur when the second nozzle opening 28 is formed, and the groove 29 does not necessarily have to be formed. This is because when the second nozzle opening 28 is formed by etching on the second nozzle layer 23, there are portions with a larger etching rate and smaller portions in the plane of the second nozzle layer 23. In order to avoid the formation of unpenetrated portions at the second nozzle opening 28, a certain degree of over-etching is performed. Therefore, at this time, since the portion with a larger etching rate penetrates at an earlier timing, grooving is likely to occur, while in the portion with a smaller etching rate in China year, grooving does not occur or is difficult to occur. That is, there are also cases where the groove 29 is formed across the circumferential direction of the second nozzle opening 28, cases where the groove 29 is formed intermittently in the circumferential direction, or cases where the groove 29 is not formed at all.

[0055] In addition, the first nozzle layer 21 does not form a groove that opens on the wall surface of the first nozzle opening 26 at the interface with the intermediate layer 22. Although the detailed situation will be described later, this is because when the first nozzle opening 26 is formed by etching on the first nozzle layer 21, due to the presence of the space portion 27, grooving does not occur.

[0056] In this way, since no groove generated by grooving is formed at the boundary between the first nozzle opening 26 and the intermediate layer 22, the first nozzle opening 26 can be set to have substantially the same opening area across the Z-axis direction. Therefore, the shape of the first nozzle opening 26 can be stabilized, thereby suppressing the occurrence of deviation in the ejection characteristics of the ink droplets ejected from the nozzle 25.

[0057] In addition, by forming a groove 29 at the boundary between the second nozzle opening 28 and the intermediate layer 22, even if excess adhesive flows into the interior of the second nozzle opening 28 when the nozzle plate 20 and the communication plate 15 are bonded with the adhesive, the adhesive will escape into the groove 29, thereby suppressing the situation where the adhesive flows into the first nozzle opening 26 side. That is to say, the groove 29 functions as an adhesive escape groove. By allowing the excess adhesive to flow into the groove 29 in this way, it is possible to suppress the change in the shape of the first nozzle opening 26 caused by the adhesive flowing into the first nozzle opening 26, and to suppress the occurrence of deviation in the ejection characteristics of the ink droplets due to the adhesive. In addition, the dominant parameters that determine the ejection characteristics of the ink droplets are the size d1 of the opening 26 of the first nozzle and the depth in the Z-axis direction. Therefore, even if a groove 29 is formed at the boundary between the second nozzle opening 28 and the intermediate layer 22, as long as no groove generated by grooving is formed at the first nozzle opening 26, it will not have a great impact on the ejection characteristics of the ink droplets.

[0058] In addition, protective films 21a, 23a such as silicon oxide are formed on the exposed surfaces of the first nozzle layer 21 and the second nozzle layer 23. That is to say, the protective film 21a is formed on the surface of the first nozzle layer 21 facing the +Z direction, on the side wall surface of the first nozzle opening 26, and on the surface of the first nozzle layer 21 exposed through the through space portion 27. In addition, the protective film 23a is formed on the surface of the second nozzle layer 23 facing the -Z direction, on the side wall surface of the second nozzle opening 28, and on the inner surface of the groove 29. That is to say, the first nozzle opening 26 and the second nozzle opening 28 are actually formed inside the protective films 21a, 23a. Although there is no particular limitation on such protective films 21a, 23a, for example, silicon oxide formed by thermal oxidation of silicon can be cited. Of course, the protective films 21a, 23a can also be formed by methods other than thermal oxidation, and their materials are not limited to silicon oxide. In addition, when the protective films 21a, 23a are formed by methods other than thermal oxidation, a protective film can also be formed on the surface of the intermediate layer 22.

[0059] In addition, the shape of the nozzle 25 is not particularly limited thereto. Here, a modified example of the nozzle 25 is illustrated in Figures 6 - 8 In addition,Figures 6 - 8 FIG. is a cross-sectional view showing a modified example of the nozzle 25 according to Embodiment 1 of the present invention.

[0060] As Figure 6 shown, the inner diameter d4 of the space portion 27 is larger than the inner diameter d2 of the second nozzle opening 28. That is, the inner diameter d4 of the space portion 27 and the inner diameter d2 of the second nozzle opening 28 satisfy the relationship d4>d2. In this way, by setting the inner diameter d4 of the space portion 27 to be larger than the inner diameter d2 of the second nozzle opening 28, the side wall of the space portion 27 is formed outside the side wall of the second nozzle opening 28. That is, a recess is formed between the side wall of the second nozzle opening 28 and the side wall of the first nozzle opening 26 by the space portion 27. In this way, by forming the recess by the space portion 27, foreign matter contained in the ink flowing in from the second nozzle opening 28 is captured in the space portion 27, and the situation of the foreign matter facing the first nozzle opening 26 is reduced, thereby suppressing clogging of the first nozzle opening 26 caused by foreign matter. In addition, by providing the space portion 27 that forms a recess, even if excess adhesive flows into the inside of the second nozzle opening 28 when the nozzle plate 20 and the communication plate 15 are bonded with an adhesive, the adhesive will escape into the space portion 27, thereby suppressing the situation where the adhesive flows into the first nozzle opening 26 side. That is, the space portion 27 also functions as an adhesive escape groove. In this way, by allowing excess adhesive to flow into the space portion 27, it is possible to suppress a change in the shape of the first nozzle opening 26 caused by the adhesive flowing into the first nozzle opening 26, and further suppress a deviation in the ink droplet ejection characteristics due to the adhesive.

[0061] In addition, as Figure 7 shown, the space portion 27 includes a first portion 27a on the second nozzle opening 28 side and a second portion 27b having a smaller inner diameter than the first portion 27a on the first nozzle opening 26 side. The inner diameter d5 of the first portion 27a is larger than the inner diameter d2 of the second nozzle opening 28, and the inner diameter d6 of the second portion 27b is smaller than the inner diameter d2 of the second nozzle opening 28. That is, the inner diameter d5 of the first portion 27a, the inner diameter d6 of the second portion 27b, and the inner diameter d2 of the second nozzle opening 28 satisfy the relationship d5>d2>d6. In addition, the inner diameter d5 of the first portion 27a and the inner diameter d6 of the second portion 27b are respectively larger than the inner diameter d1 of the first nozzle opening 26. That is, the inner diameter d5 of the first portion 27a, the inner diameter d6 of the second portion 27b, the inner diameter d1 of the first nozzle opening 26, and the inner diameter d2 of the second nozzle opening 28 satisfy the relationship d5>d2>d6>d1. In this way, even if the space portion 27 has a structure including the first portion 27a and the second portion 27b, it is the same as the above Figure 6Similarly, a recess is formed between the side wall of the second nozzle opening 28 and the side wall of the second portion 27b through the first portion 27a. Therefore, in the recess formed between the side walls of the first nozzle opening 26 and the second nozzle opening 28 through the first portion 27a, foreign matter contained in the ink can be captured, thereby suppressing clogging of the first nozzle opening 26 caused by foreign matter. In addition, excess adhesive flows into the recess formed by the first portion 27a, thereby suppressing deformation of the shape of the first nozzle opening 26 caused by the adhesive. In addition, since the inner diameter can be gradually reduced in the order of the second nozzle opening 28, the second portion 27b, and the first nozzle opening 26, the flow of the ink is not easily obstructed.

[0062] In addition, as Figure 8 shown, the inner diameter d7 of the space portion 27 is smaller than the inner diameter d2 of the second nozzle opening 28 and smaller than the inner diameter d1 of the first nozzle opening 26. That is, the inner diameter d7 of the space portion 27, the inner diameter d1 of the first nozzle opening 26, and the inner diameter d2 of the second nozzle opening 28 satisfy the relationship d2 > d1 > d7. In this way, by making the inner diameter d7 of the space portion 27 smaller than the inner diameter d1 of the first nozzle opening 26, even if foreign matter invades from the first nozzle opening 26, the intermediate layer 22 protruding inward compared to the first nozzle opening 26 can suppress the movement of the foreign matter toward the second nozzle opening 28 side.

[0063] In the present embodiment, the diaphragm 50 has an elastic film 51 made of silicon oxide provided on the pressure chamber substrate 10 side and an insulator film 52 made of zirconia provided on the surface of the elastic film 51 facing the -Z direction. In addition, the diaphragm 50 may be composed only of the elastic film 51, may be composed only of the insulator film 52, or may have a structure having other films in addition to the elastic film 51 and the insulator film 52.

[0064] The piezoelectric actuator 300 includes a first electrode 60, a piezoelectric body layer 70, and a second electrode 80 that are sequentially stacked on the diaphragm 50 in the -Z direction. Such a piezoelectric actuator 300 is also referred to as a piezoelectric element and refers to the part including the first electrode 60, the piezoelectric body layer 70, and the second electrode 80. In addition, the part where piezoelectric strain is generated in the piezoelectric body layer 70 when a voltage is applied between the first electrode 60 and the second electrode 80 is referred to as the active part 310. In contrast, the part where no piezoelectric strain is generated in the piezoelectric body layer 70 is referred to as the inactive part. That is, the active part 310 refers to the part of the piezoelectric body layer 70 that is sandwiched between the first electrode 60 and the second electrode 80. In the present embodiment, the active part 310 is formed for each pressure chamber 12. That is, a plurality of active parts 310 are formed in the piezoelectric actuator 300. The plurality of active parts 310 serve as driving elements that cause a pressure change in the ink in the pressure chamber 12. And generally, one of the electrodes of the active part 310 is set as an independent electrode that is independent for each active part 310, and the other electrode is set as a common electrode that is common among the plurality of active parts 310 to constitute. In the present embodiment, the first electrode 60 constitutes the independent electrode, and the second electrode 80 constitutes the common electrode. Of course, it is also possible that the first electrode 60 constitutes the common electrode and the second electrode 80 constitutes the independent electrode.

[0065] As Figure 3 shown, the first electrode 60 is cut for each pressure chamber 12 and constitutes an independent electrode that is independent for each active part 310. As Figure 3 and Figure 4 shown, the width of the piezoelectric body layer 70 in the Y-axis direction is a predetermined width, and it is continuously provided so as to straddle the X-axis direction. In addition, as Figure 3 shown, although a plurality of recesses 71 are formed on the piezoelectric body layer 70 at positions that do not overlap with the first electrode 60, the recesses 71 may not be provided. Such a piezoelectric body layer 70 is constituted by using, for example, a piezoelectric material composed of a perovskite-structured composite oxide represented by the general formula ABO3. As Figure 3 and Figure 4 shown, the second electrode 80 is continuously provided on the -Z direction side of the piezoelectric body layer 70, which is the side opposite to the first electrode 60, and constitutes a common electrode that is common among the plurality of active parts 310. The second electrode 80 is continuously provided so as to straddle the X-axis direction with the Y-axis direction being a predetermined width.

[0066] In addition, an independent lead electrode 91 as a lead wiring is led out from the first electrode 60. A common lead electrode 92 as a lead wiring is led out from the second electrode 80. At ends of these independent lead electrode 91 and common lead electrode 92 on the side opposite to the ends connected to the piezoelectric actuator 300, a wiring component 110 made of a flexible substrate having flexibility is connected. A drive signal selection circuit 111 is mounted on the wiring component 110. The drive signal selection circuit 111 has a plurality of switching elements for selecting whether to supply a drive signal COM for driving each active part 310 to each active part 310. That is, the wiring component 110 in the present embodiment is a COF (Chip On Film). In addition, in the wiring component 110, the drive signal selection circuit 111 may not be provided. That is, the wiring component 110 may also be an FFC (Flexible Flat Cable), an FPC (Flexible Printed Circuits), or the like.

[0067] As Figure 2 and Figure 4 shown, a protection substrate 30 having substantially the same size as the pressure chamber substrate 10 is bonded to the surface of the pressure chamber substrate 10 facing the -Z direction. The protection substrate 30 has a storage part 31 as a space for protecting the piezoelectric actuator 300. The storage part 31 is a component independently provided for each column of the piezoelectric actuators 300 arranged side by side in the X-axis direction, and two are formed side by side in the Y-axis direction. In addition, on the protection substrate 30, a through hole 32 penetrating in the Z-axis direction is provided between the two storage parts 31 arranged side by side in the Y-axis direction. The ends of the independent lead electrode 91 and the common lead electrode 92 led out from the electrodes of the piezoelectric actuator 300 extend so as to be exposed in the through hole 32, and the independent lead electrode 91, the common lead electrode 92, and the wiring component 110 are electrically connected in the through hole 32. As such a protection substrate 30, for example, it is made of a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates like the pressure chamber substrate 10.

[0068] In addition, a housing member 40 is fixed to the protective substrate 30. The housing member 40 and the pressure chamber substrate 10 define a manifold 100 communicating with a plurality of pressure chambers 12. The housing member 40 has substantially the same shape as the above-described communication plate 15 in a top view, is joined to the protective substrate 30, and is also joined to the above-described communication plate 15. Such a housing member 40 has a recess 41 on the side of the protective substrate 30 that can accommodate the depth of the pressure chamber substrate 10 and the protective substrate 30. In addition, in the housing member 40, a third manifold portion 42 communicating with the first manifold portion 17 of the communication plate 15 is provided. And, the manifold 100 of the present embodiment is constituted by the first manifold portion 17 and the second manifold portion 18 provided in the communication plate 15 and the third manifold portion 42 provided in the housing member 40. The manifold 100 is provided for each column of the pressure chambers 12, that is, two in total are provided. Each manifold 100 is continuously provided across the X-axis direction in which the pressure chambers 12 are arranged side by side, and the supply communication channels 19 connecting the respective pressure chambers 12 and the manifold 100 are arranged side by side in the X-axis direction. In addition, on the housing member 40, an introduction port 44 communicating with the manifold 100 and for supplying ink to each manifold 100 is provided. In addition, on the housing member 40, a connection port 43 communicating with the through hole 32 of the protective substrate 30 and through which the wiring member 110 is inserted is provided, and the wiring member 110 is led out to the side of the surface of the liquid ejection head H facing the -Z direction via the connection port 43. As the housing member 40, a metal material, a resin material, etc. can be used.

[0069] In addition, on the surface on the +Z direction side where the first manifold portion 17 and the second manifold portion 18 of the communication plate 15 open, a plastic substrate 45 is provided. The plastic substrate 45 seals the openings on the +Z direction side of the first manifold portion 17 and the second manifold portion 18. In the present embodiment, such a plastic substrate 45 includes a sealing film 46 made of a flexible film and a fixing substrate 47 made of a hard material such as metal. Since the region of the fixing substrate 47 facing the manifold 100 becomes an opening 48 that is completely removed in the thickness direction, one surface of the manifold 100 becomes a plastic portion 49 that is sealed only by the flexible sealing film 46, which is a flexible portion.

[0070] In such a liquid ejection head H, ink is sucked in from the introduction port 44, and the flow path inside is filled with ink from the manifold 100 to the nozzle 25. Thereafter, in accordance with a signal from the drive signal selection circuit 111, by applying a voltage to each active portion 310 corresponding to the pressure chamber 12, the diaphragm 50 and the piezoelectric actuator 300 are bent and deformed together. As a result, the pressure of the ink in the pressure chamber 12 increases, and ink droplets are ejected from a predetermined nozzle 25.

[0071] Refer toFigures 9 - 15 The manufacturing method of the nozzle plate 20 of the liquid ejection head H according to the present embodiment will be described. In addition, Figures 9 - 15 FIG. is a cross-sectional view for explaining the manufacturing method of the nozzle plate.

[0072] First, as Figure 9 shown, a first process of preparing the substrate 120 is performed. The substrate 120 is a member in which a first nozzle layer 21 formed of silicon, an intermediate layer 22 formed of silicon oxide, and a second nozzle layer 23 formed of silicon are stacked in the -Z direction in this order, and a space portion 27 is formed in a part of the intermediate layer 22.

[0073] The substrate 120 is formed of a so-called SOI substrate. That is, in the first process, first, an oxide film is formed across the surface of the second nozzle layer 23 by oxidizing the surface of the second nozzle layer 23. Next, the oxide film is patterned into a specified shape by photolithography to form the intermediate layer 22 having the space portion 27. Thereafter, the second nozzle layer 23 on which the intermediate layer 22 is formed and the first nozzle layer 21 are bonded to form the substrate 120. In addition, for the space portion 27 of the intermediate layer 22, as previously shown in Figure 5 , its inner diameter d3 is formed to be smaller than the inner diameter d2 of the second nozzle opening 28. In addition, since the intermediate layer 22 will be etched in a subsequent process, it is preferably formed with an inner diameter smaller than the inner diameter d3 in advance. In addition, as shown in Figure 8 , the space portion 27 may also be formed in advance with an inner diameter d7 smaller than the inner diameter d1 of the first nozzle opening 26. In addition, as long as an SOI substrate in which the space portion 27 is formed in a part of the intermediate layer 22 can be prepared, the first process may not be the manufacturing method as described above. For example, instead of the second nozzle layer 23, the surface of the first nozzle layer 21 may be oxidized. Alternatively, an SOI substrate in which the space portion 27 is formed in a part of the intermediate layer 22 may be provided from the outside.

[0074] Next, as Figure 10 shown, a second process is performed, that is, for a first region 121 where at least a part of the first nozzle layer 21 overlaps with the space portion 27 (refer to Figure 9), a Bosch process is implemented and a first nozzle opening 26 communicating with the space portion 27 is provided. For the second process, in the present embodiment, the Bosch process is implemented starting from the surface of the first nozzle layer 21 on the side opposite to the intermediate layer 22, that is, the surface of the first nozzle layer 21 facing the +Z direction. In the Bosch process of forming the first nozzle opening 26, since the space portion 27 is formed in the intermediate layer 22, grooving caused by charging of the intermediate layer 22 does not occur. This is because, since the surface of the second nozzle layer 23 facing the +Z direction is etched when passing through the first nozzle layer 21, ions do not stay between the first nozzle opening 26 and the intermediate layer 22. That is, at the boundary between the first nozzle opening 26 and the intermediate layer 22, a groove formed by grooving is not formed. Incidentally, if the space portion 27 is not formed in the intermediate layer 22, when the first nozzle opening 26 is formed in the first nozzle layer 21 by the Bosch process, grooving may occur, and thus a groove may be formed at the boundary between the first nozzle opening 26 and the intermediate layer 22. In the present embodiment, by previously providing the space portion 27 in the intermediate layer 22, generation of grooving can be suppressed when forming the first nozzle opening 26, and further, formation of a groove at the boundary between the first nozzle opening 26 and the intermediate layer 22 can be suppressed. Therefore, the first nozzle opening 26 can be formed in a desired shape, and thus an adverse effect on the ejection characteristics caused by a defective shape of the first nozzle opening 26 can be suppressed.

[0075] Next, as Figure 11 shown, after the second process, a fourth process of forming an oxide film 122 so as to cover at least the first nozzle opening 26 of the first nozzle layer 21 is implemented. For the fourth process, in the present embodiment, by oxidizing the entire substrate 120, an oxide film 122 is formed on the surface of the first nozzle layer 21 not covered by the intermediate layer 22, that is, on the exposed surface including the side wall surface of the first nozzle opening 26 of the first nozzle layer 21, and an oxide film 123 is formed on the surface of the second nozzle layer 23 not covered by the intermediate layer 22.

[0076] Next, as Figure 12 shown, after the fourth process, a fifth process of thinning the second nozzle layer 23 of the substrate 120 is implemented. The fifth process grinds and polishes the second nozzle layer 23 by chemical mechanical polishing (CMP) or the like from the side of the second nozzle layer 23 opposite to the intermediate layer 22, that is, the surface facing the -Z direction. In addition, the thinning of the second nozzle layer 23 in the fifth process is not limited to grinding and polishing, and for example, the second nozzle layer 23 may be thinned by etching.

[0077] Next, as Figure 13As shown, a third process is implemented, that is, for a second region 124 where at least a part of the second nozzle layer 23 overlaps with the space portion 27 (refer to Figure 12 ), a Bosch process is implemented and a second nozzle opening 28 communicating with the space portion 27 is provided. In the third process, in the present embodiment, the Bosch process is implemented starting from the surface of the second nozzle layer 23 on the side opposite to the intermediate layer 22, that is, the surface of the second nozzle layer 23 facing the -Z direction. In the Bosch process for forming the second nozzle opening 28, since the oxide film 123 functions as an etching stop layer, grooving caused by the charging of the oxide film 123 occurs, and thus a groove 29 is formed at the boundary between the second nozzle opening 28 and the intermediate layer 22. In this way, even if a groove 29 is formed at the boundary between the second nozzle opening 28 and the intermediate layer 22, as long as no groove is formed at the first nozzle opening 26, it will not have a great impact on the ink droplet ejection characteristics. In addition, since the third process is implemented after the fourth process, the first nozzle layer 21 is covered by the oxide film 122, so it is possible to suppress the case where the first nozzle layer 21 is etched simultaneously when the second nozzle layer 23 is formed in the third process.

[0078] Next, as Figure 14 shown, the oxide films 122 and 123 of the substrate 120 are removed. In the present embodiment, the oxide film 122 of the first nozzle layer 21 and the oxide film 123 of the second nozzle layer 23 are removed by etching with hydrofluoric acid or the like. Thereby, the oxide film 123 that divides the first nozzle opening 26 and the second nozzle opening 28 is removed, and thus the first nozzle opening 26 and the second nozzle opening 28 communicate through the space portion 27. In addition, in this process, when the oxide films 122 and 123 are removed by etching, a part of the intermediate layer 22 formed of silicon oxide is also removed. Therefore, for example, by adjusting the etching time, it is also possible to form, as Figure 5 shown, the inner diameter d3 of the space portion 27 to be smaller than the inner diameter d2 of the second nozzle opening 28, and it is also possible to form, as Figure 6 shown, the inner diameter d4 of the space portion 27 to be larger than the inner diameter d2 of the second nozzle opening 28. In addition, by stopping the etching midway when the space portion 27 is in the state as Figure 6 shown, it is also possible to form, as Figure 7 shown, a space portion 27 having a first part 27a and a second part 27b. Incidentally, although in the present embodiment, in the first process, the inner diameter d3 of the space portion 27 is formed to be larger than the inner diameter d1 of the first nozzle opening 26 and smaller than the inner diameter d2 of the second nozzle opening 28, it is not particularly limited thereto. For example, as Figure 8 shown, in the first process, if the inner diameter d7 of the space portion 27 is formed in advance to be smaller than the inner diameter d1 of the first nozzle opening 26, then inFigure 14 In the process shown, by adjusting the etching time, it is also possible to form Figures 5 - 8 the space portion 27 shown in any one of Figure 5 The figure showing the formation of the space portion 27 shown in

[0079] Next, as Figure 15 shown, a protective film 21a is formed on the first nozzle layer 21, and a protective film 23a is formed on the second nozzle layer 23. In the present embodiment, by oxidizing the entire substrate 120, the protective films 21a and 23a are simultaneously formed on the first nozzle layer 21 and the second nozzle layer 23. Thus, the nozzle plate 20 of the present embodiment is manufactured.

[0080] As described above, in the manufacturing method of the nozzle plate 20 of the present embodiment, no groove caused by grooving is formed at the boundary on the intermediate layer 22 side of the first nozzle opening 26. Therefore, the shape of the first nozzle opening 26 can be stably formed. In addition, since the length of the first nozzle opening 26 in the Z-axis direction can be managed by the thickness of the first nozzle layer 21, the length of the first nozzle opening 26 can be formed with higher precision compared to the case of adjusting by the etching time. Therefore, it is possible to suppress the occurrence of variations in the ink ejection characteristics due to the unstable shape of the nozzle 25, and it is possible to suppress the occurrence of variations in the printing quality.

[0081] Embodiment 2

[0082] Figure 16 FIG. is a cross-sectional view of the main part of the nozzle plate 20 according to Embodiment 2 of the present invention. In addition, the same reference numerals are given to the same components as those in the above-described Embodiment 1, and repeated descriptions are omitted.

[0083] Similar to the above-described Embodiment 1, the nozzle plate 20 of the present embodiment is composed of an SOI substrate including a first nozzle layer 21, an intermediate layer 22, and a second nozzle layer 23.

[0084] The nozzle 25 includes a first nozzle opening 26, a space portion 27, and a second nozzle opening 28. The inner diameter d8 of the space portion 27 is substantially the same as the inner diameter d1 of the first nozzle opening 26, or is only slightly larger than the inner diameter d1 of the first nozzle opening 26 by the amount of the protective film 21a.

[0085] In addition, the inner diameter d8 of the space portion 27 is smaller than the inner diameter d2 of the second nozzle opening 28.

[0086] On the respective side walls of the first nozzle opening 26 and the second nozzle opening 28, fan-shaped notches 26a and 28a are formed. In addition, no fan-shaped notch is formed on the side wall of the space portion 27, and it is flat along the Z-axis direction.

[0087] In addition, no groove caused by grooving is formed at the boundary between the second nozzle opening 28 and the intermediate layer 22. No groove caused by grooving is formed at the boundary between the first nozzle opening 26 and the intermediate layer 22.

[0088] In such a nozzle 25, since no groove caused by grooving is formed at the first nozzle opening 26 and the second nozzle opening 28, the shapes of the first nozzle opening 26 and the second nozzle opening 28 can be formed into desired shapes with high precision.

[0089] Refer to Figures 17 - 20 to describe the manufacturing method of such a nozzle plate 20. In addition, Figures 17 - 20 FIG. is a cross-sectional view for describing the manufacturing method of the nozzle plate 20 according to Embodiment 2 of the present invention.

[0090] First, as Figure 17 shown, a first process of preparing a substrate 120 is performed, where the substrate 120 is a component in which a first nozzle layer 21 formed of silicon, an intermediate layer 22 formed of silicon oxide, and a second nozzle layer 23 formed of silicon are stacked in the -Z direction in this order, and a space portion 27 is formed in a part of the intermediate layer 22.

[0091] Next, as Figure 18 shown, after the first process, a fifth process of thinning the second nozzle layer 23 of the substrate 120 is performed.

[0092] Next, as Figure 19 shown, after the fifth process, a third process is performed, that is, for a second region 124 (refer to Figure 18 ) where at least a part of the second nozzle layer 23 overlaps with the space portion 27, a Bosch process is performed to provide a second nozzle opening 28 communicating with the space portion 27. In the third process, in the present embodiment, the Bosch process is performed from the surface of the second nozzle layer 23 opposite to the intermediate layer 22, that is, from the surface of the second nozzle layer 23 facing the -Z direction. In the Bosch process of forming the second nozzle opening 28, since the space portion 27 is formed in the intermediate layer 22, it is not easy to generate grooving, and thus no groove is formed at the boundary between the second nozzle opening 28 and the intermediate layer 22.

[0093] Next, as Figure 20 shown, after the third process, a second process is performed, that is, for a first region 121 (refer to Figure 19)The Bosch process is implemented from the second nozzle layer 23 side, thereby providing a first nozzle opening 26 communicating with the space portion 27. In the second process, the surface of the first nozzle layer 21 on the second nozzle layer 23 side, that is, the surface facing the -Z direction, is covered by the intermediate layer 22. That is to say, in the second process, the Bosch process is performed on the first nozzle layer 21 using the intermediate layer 22 as a mask, thereby forming the first nozzle opening 26. That is to say, the above-mentioned fifth process is implemented after the first process and before the third process.

[0094] In this way, for the first nozzle opening 26, since it is formed by performing the Bosch process on the first nozzle layer 21 from the second nozzle layer 23 side, no grooving occurs, and no grooves caused by grooving are formed on the side walls of the first nozzle opening 26. In addition, since the length of the first nozzle opening 26 in the Z-axis direction is defined by the thickness of the first nozzle layer 21, it is possible to suppress the occurrence of deviations in the length of the first nozzle layer 21 in the Z-axis direction.

[0095] After that, Figure 15 similarly to the above-described Embodiment 1, a protective film 21a is formed on the first nozzle layer 21, and a protective film 23a is formed on the second nozzle layer 23. Thereby, the nozzle plate 20 is manufactured.

[0096] As described above, in the manufacturing method of the nozzle plate 20 of the present embodiment, no grooves caused by grooving are formed at the boundary of the first nozzle opening 26 on the intermediate layer 22 side. Therefore, the shape of the first nozzle opening 26 can be stably formed. In addition, since the length of the first nozzle opening 26 in the Z-axis direction can be managed by the thickness of the first nozzle layer 21, compared with the case of adjusting by the etching time, the length of the first nozzle opening 26 can be formed with high precision. Therefore, it is possible to suppress the occurrence of deviations in the ink ejection characteristics due to the unstable shape of the nozzle 25, and it is possible to suppress the occurrence of deviations in the printing quality. In addition, in the manufacturing method of the nozzle plate 20 of the present embodiment, no grooves caused by grooving are formed at the second nozzle opening 28 either. Thus, it is also possible to suppress the occurrence of deviations in the shape of the nozzle 25.

[0097] Other Embodiments

[0098] Although the above describes various embodiments of the present invention, the basic structure of the present invention is not limited to the above structure.

[0099] Although in each of the above-described embodiments, a film-type piezoelectric actuator has been described as a driving element for causing a pressure change in the pressure chamber 12, it is not particularly limited thereto. For example, a thick-film piezoelectric actuator formed by a method such as screen printing, or a longitudinal vibration type piezoelectric actuator in which a piezoelectric material and an electrode forming material are alternately laminated and expanded and contracted in the axial direction can be used. In addition, as a driving element, a driving element that arranges a heating element in a pressure generating chamber and ejects droplets from a nozzle by bubbles generated by the heating of the heating element, or a so-called electrostatic actuator that generates static electricity between a diaphragm and an electrode and deforms the diaphragm by electrostatic force to eject droplets from the nozzle can be used.

[0100] Furthermore, the present invention is an invention that broadly targets the entire liquid ejection device including the liquid ejection head. Examples of the liquid ejection head include recording heads such as various inkjet recording heads used in image recording devices such as printers, and color material ejection heads used in the manufacture of color filters for liquid crystal displays and the like. In addition, examples of the liquid ejection head include electrode material ejection heads used in the formation of electrodes for organic EL displays, FED (field emission displays), etc., and biological organic matter ejection heads used in the manufacture of biochips, and the present invention can also be applied to liquid ejection devices including these liquid ejection heads.

[0101] In addition, although an inkjet recording device has been described as an example of the liquid ejection device, it can also be used in a liquid ejection device using the above-described other liquid ejection heads.

[0102] In addition, although in the above-described embodiment, an inkjet recording head that ejects ink has been described as an example of the liquid ejection head, and an inkjet recording device has been described as an example of the liquid ejection device, the present invention is a broad description targeting the entire liquid ejection head and liquid ejection device, and thus it is obvious that the present invention can also be applied to a liquid ejection head or a liquid ejection device that ejects a liquid other than ink. As other liquid ejection heads, for example, various recording heads used in image recording devices such as printers, color material ejection heads used in the manufacture of color filters for liquid crystal displays and the like, electrode material ejection heads used in the formation of electrodes for organic EL displays, FED (field emission displays), etc., and biological organic matter ejection heads used in the manufacture of biochips can be cited, and the present invention can also be applied to a liquid ejection device including the liquid ejection head in question.

[0103] Supplementary Note

[0104] From the examples illustrated above, the following structures can be grasped, for example.

[0105] The manufacturing method of the nozzle plate according to Method 1, which is a preferred method, is a manufacturing method of a nozzle plate provided with nozzles mounted on a liquid ejector head, and includes the following steps: a first step of preparing a substrate in which a first nozzle layer made of silicon, an intermediate layer made of silicon oxide, and a second nozzle layer made of silicon are laminated in this order, and a space portion is provided in a part of the intermediate layer; a second step of, after the first step, performing a Bosch process on a first region where at least a part of the first nozzle layer overlaps with the space portion to provide a first nozzle opening communicating with the space portion; and a third step of performing a Bosch process on a second region where at least a part of the second nozzle layer overlaps with the space portion to provide a second nozzle opening communicating with the space portion and having a larger diameter than the first nozzle opening.

[0106] Accordingly, since the space portion is formed in the intermediate layer in advance when the first nozzle opening is formed in the second step, it is difficult to generate grooving when the first nozzle opening is formed, and thus a groove is not formed at the boundary between the first nozzle opening and the intermediate layer. Therefore, the first nozzle opening can be formed into a desired shape with high precision. In addition, the length of the first nozzle opening can be formed with high precision according to the thickness of the first nozzle layer.

[0107] In Method 2, which is a specific example of Method 1, the third step is performed after the second step. Accordingly, the second step and the third step can be performed from both sides of the substrate, and thus a nozzle with high precision can be formed.

[0108] In Method 3, which is a specific example of Method 2, a fourth step is further included. The fourth step forms an oxide film so as to cover at least the first nozzle opening after the second step, and the third step is performed after the fourth step. Accordingly, when the third step is performed, the etching of the first nozzle opening can be suppressed by the oxide film.

[0109] In Method 4, which is a specific example of Method 3, a fifth step is further included. The fifth step thins the second nozzle layer after the fourth step. Accordingly, by not thinning the first nozzle layer, the length of the first nozzle opening can be formed with high precision according to the thickness of the first nozzle layer, and a nozzle plate with a desired thickness can be formed.

[0110] In Method 5, which is a specific example of Method 2, the Bosch process is performed from the first nozzle layer side in the second step, and the Bosch process is performed from the second nozzle layer side in the third step. Accordingly, the first nozzle opening and the second nozzle opening can be easily and highly precisely formed by the Bosch process.

[0111] In Mode 6, which is a specific example of Mode 1, the third process is implemented after the first process and before the second process. Accordingly, the third process can be implemented between the first process and the second process.

[0112] In Mode 7, which is a specific example of Mode 6, a fifth process is further provided. The fifth process thins the second nozzle layer after the first process and before the third process. Accordingly, by not thinning the first nozzle layer, the length of the first nozzle opening can be accurately formed according to the thickness of the first nozzle layer, and a nozzle plate with a desired thickness can be formed.

[0113] In Mode 8, which is a specific example of Mode 6, the Bosch process is implemented from the side of the second nozzle layer in the second process and the third process. Accordingly, the Bosch process can be implemented from the same side of the substrate to form the first nozzle opening and the second nozzle opening.

[0114] In Mode 9, which is a specific example of Mode 7, in the second process, the surface of the first nozzle layer on the side of the second nozzle layer is covered by the intermediate layer. Accordingly, when implementing the second process, by covering the surface of the first nozzle layer with the intermediate layer, the etching of the first nozzle layer when forming the second nozzle opening can be suppressed.

[0115] The liquid ejection head according to Mode 10, which is a preferred mode, includes: a nozzle plate provided with nozzles; a pressure chamber substrate provided with a pressure chamber for applying pressure to the liquid to eject the liquid from the nozzles. In the liquid ejection head, a first nozzle layer formed of silicon, an intermediate layer formed of silicon oxide, and a second nozzle layer formed of silicon are laminated on the nozzle plate in this order. In the first nozzle layer, a first nozzle opening is provided. In the intermediate layer, a space portion communicating with the first nozzle opening is provided. In the second nozzle layer, a second nozzle opening communicating with the space portion and having a larger diameter than the first nozzle opening is provided. Fan-shaped notches are respectively formed at the first nozzle opening and the second nozzle opening, and no fan-shaped notch is formed at the space portion.

[0116] Accordingly, fan-shaped notches can be formed at the first nozzle opening and the second nozzle opening, that is, they can be accurately formed by the Bosch process. In addition, no fan-shaped notch is formed at the space portion, that is, since the space portion is formed in advance when forming at least one of the first nozzle opening and the second nozzle opening, when forming at least one of the first nozzle opening and the second nozzle opening, no groove caused by grooving is formed due to the space portion, and the nozzle can be accurately formed.

[0117] In Mode 11, which is a specific example of Mode 10, the diameter of the space portion is larger than the diameter of the second nozzle opening. Accordingly, a recess is formed between the first nozzle opening and the second nozzle opening through the space portion. Foreign matter contained in the liquid is captured in the recess formed through the space portion, thereby suppressing clogging of the first nozzle opening caused by foreign matter. In addition, when bonding the second nozzle layer side of the nozzle plate to other components, excess adhesive can flow into the recess formed through the space portion, thereby suppressing the situation where excess adhesive flows into the first nozzle opening side.

[0118] In Mode 12, which is a specific example of Mode 10, the diameter of the space portion is larger than the diameter of the first nozzle opening and smaller than the diameter of the second nozzle opening. Accordingly, since the diameter gradually decreases from the second nozzle opening toward the first nozzle opening, liquid can be ejected from the nozzle under conditions that do not impede the flow of the liquid.

[0119] In Mode 13, which is a specific example of Mode 10, the diameter of the space portion is smaller than the diameter of the first nozzle opening. Accordingly, even if foreign matter invades from the first nozzle opening, the intermediate layer that protrudes more than the first nozzle opening can suppress the foreign matter from reaching the second nozzle opening.

[0120] In Mode 14, which is a specific example of Modes 10 to 13, the intermediate layer is thinner than both the first nozzle layer and the second nozzle layer. Accordingly, even if the intermediate layer is thin, it can fully function during the manufacture of the nozzle plate.

[0121] In Mode 15, which is a specific example of Mode 14, the first nozzle layer is thinner than the second nozzle layer. Accordingly, the length of the first nozzle opening can be defined by the thickness of the first nozzle layer, and the second nozzle layer can be used to adjust the thickness of the nozzle plate.

[0122] In Mode 16, which is a specific example of Mode 10, no groove is formed at the boundary between the first nozzle layer and the space portion. Accordingly, by not forming a groove in the first nozzle layer, the shape of the first nozzle opening can be formed with high precision.

[0123] In Mode 17, which is a specific example of Mode 16, the second nozzle layer forms a groove at the boundary with the space portion. Accordingly, a recess is formed between the first nozzle opening and the second nozzle opening through the groove. Foreign substances contained in the liquid are captured in the recess formed by the groove, thereby suppressing clogging of the first nozzle opening caused by foreign substances. In addition, when bonding the second nozzle layer side of the nozzle plate to other components, excess adhesive can flow into the recess formed by the groove, thereby suppressing the situation where excess adhesive flows into the first nozzle opening side. Further, since the groove of the second nozzle opening has little influence on the ejection characteristics of the nozzle, deterioration of the ejection characteristics can be suppressed.

[0124] In Mode 18, which is a specific example of Mode 10, the diameter of the space portion at a position closer to the second nozzle opening is larger than the diameter at a position closer to the first nozzle opening. Accordingly, a recess is formed on the side wall between the first nozzle opening and the second nozzle opening, so that foreign substances contained in the liquid can be captured, or excess adhesive can be captured, and the flow of the liquid can be hardly obstructed.

[0125] The liquid ejection device according to Mode 19, which is a preferred mode, includes the liquid ejection head described in the above modes. Accordingly, a liquid ejection device capable of suppressing variations in ejection characteristics and improving printing quality can be achieved.

[0126] Symbol Explanation

[0127] H... Liquid ejection head; S... Medium; 1... Liquid ejection device; 3... Liquid reservoir; 4... Control unit; 5... Conveying mechanism; 5a... Conveying roller; 6... Moving mechanism; 7... Holding body; 8... Conveyor belt; 10... Pressure chamber substrate; 12... Pressure chamber; 15... Communication plate; 16... Nozzle communication channel; 17... First manifold part; 18... Second manifold part; 19... Supply communication channel; 20... Nozzle plate; 21... First nozzle layer; 21a, 23a... Protective film; 22... Intermediate layer; 23... Second nozzle layer; 25... Nozzle; 26... First nozzle opening; 26a, 28a... Sector-shaped notch; 27... Space part; 27a... First part; 27b... Second part; 28... Second nozzle opening; 29... Groove; 30... Protective substrate; 31... Storage part; 32... Through hole; 40... Housing component; 41... Recess; 42... Third manifold part; 43... Connection port; 44... Introduction port; 45... Plastic substrate; 46... Sealing film; 47... Fixed substrate; 48... Opening part; 49... Plastic part; 50... Diaphragm; 51... Elastic film; 52... Insulator film; 60... First electrode; 70... Piezoelectric layer; 71... Recess; 80... Second electrode; 91... Independent lead electrode; 92... Common lead electrode; 100... Manifold; 110... Wiring component; 111... Drive signal selection circuit; 120... Substrate; 121... First region; 122, 123... Oxide film; 124... Second region; 300... Piezoelectric actuator; 310... Active part.

Claims

1. A method for manufacturing a nozzle plate, characterized in that: The method is a method for manufacturing a nozzle plate provided with nozzles to be mounted on a liquid ejecting head, and comprises the following steps, namely: A first step is to prepare a substrate in which a first nozzle layer formed of silicon, an intermediate layer formed of silicon oxide, and a second nozzle layer formed of silicon are stacked in this order, and a space portion is provided in a portion of the intermediate layer; a second step, after the first step, performing a Bosch process on a first region where at least a portion of the first nozzle layer overlaps with the space portion, thereby providing a first nozzle opening communicating with the space portion; The third step is to perform a Bosch process on a second region where at least a portion of the second nozzle layer overlaps with the space portion, thereby providing a second nozzle opening that communicates with the space portion and has a larger diameter than the first nozzle opening.

2. The method for manufacturing a nozzle plate according to claim 1, characterized in that , The third step is performed after the second step.

3. The method for manufacturing a nozzle plate according to claim 2, characterized in that , The method further comprises a fourth step of forming an oxide film to cover at least the first nozzle opening after the second step. The third step is performed after the fourth step.

4. The method for manufacturing a nozzle plate according to claim 3, characterized in that , The method further includes a fifth step of thinning the second nozzle layer after the fourth step.

5. The method for manufacturing a nozzle plate according to claim 2, characterized in that , The second step implements the Bosch process from the first nozzle layer side, The third step performs the Bosch process from the second nozzle layer side.

6. The method for manufacturing a nozzle plate according to claim 1, characterized in that , The third step is performed after the first step and before the second step.

7. The method for manufacturing a nozzle plate according to claim 6, characterized in that , The method further includes a fifth step of thinning the second nozzle layer after the first step and before the third step.

8. The method for manufacturing a nozzle plate according to claim 6, characterized in that , The second step and the third step are performed by a Bosch process from the second nozzle layer side.

9. The method for manufacturing a nozzle plate according to claim 7, characterized in that , In the second step, a surface of the first nozzle layer on the second nozzle layer side is covered with the intermediate layer.

10. A liquid ejecting head, characterized in that: have: a nozzle plate having nozzles disposed thereon; a pressure chamber substrate in which a pressure chamber for applying pressure to the liquid for ejecting the liquid from the nozzle is provided, In the liquid ejecting head, A first nozzle layer formed of silicon, an intermediate layer formed of silicon oxide, and a second nozzle layer formed of silicon are stacked in this order on the nozzle plate. In the first nozzle layer, a first nozzle opening is provided, In the intermediate layer, a space portion communicating with the first nozzle opening is provided, In the second nozzle layer, a second nozzle opening is provided which is communicated with the space portion and has a larger diameter than the first nozzle opening. A fan-shaped notch is formed at the first nozzle opening and the second nozzle opening, respectively. No fan-shaped notch is formed in the space portion.

11. The liquid ejecting head according to claim 10, wherein: The diameter of the space portion is larger than the diameter of the second nozzle opening.

12. The liquid ejecting head according to claim 10, wherein: The diameter of the space portion is larger than the diameter of the first nozzle opening and smaller than the diameter of the second nozzle opening.

13. The liquid ejecting head according to claim 10, wherein: The diameter of the space portion is smaller than the diameter of the first nozzle opening.

14. The liquid ejecting head according to any one of claims 10 to 13, wherein: The middle layer is thinner than the first nozzle layer and the second nozzle layer.

15. The liquid ejecting head according to claim 14, wherein: The first nozzle layer is thinner than the second nozzle layer.

16. The liquid ejecting head according to claim 10, wherein: The first nozzle layer has no groove formed at a boundary with the space portion.

17. The liquid ejecting head according to claim 16, wherein: The second nozzle layer forms a groove at a boundary with the space portion.

18. The liquid ejecting head according to claim 10, wherein: A diameter of the space portion at a position close to the second nozzle opening is larger than a diameter of the space portion at a position close to the first nozzle opening.

19. A liquid ejection device, characterized in that: A liquid ejecting head according to claim 10 is provided.

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