Liquid jet head, liquid jet apparatus, and method of manufacturing a liquid jet head

Abstract

To provide a liquid jet head which can inhibit accumulation of air bubbles near a nozzle communication passage, and to provide a liquid jet device and a manufacturing method of the liquid jet head.SOLUTION: A joint substrate 200 is provided with nozzle communication passages 31 each of which allows a pressure chamber 12 and a nozzle 21 to communicate with each other. The nozzle communication passage 31 has: a pair of first inner wall surfaces forming wall surfaces in a first direction; and a pair of second inner wall surfaces forming wall surfaces in a second direction orthogonal to the first direction. At least one of the second inner wall surfaces includes an inclination surface which inclines so that a length of the nozzle communication passage 31 becomes shorter toward the nozzle 21 side. An angle of the inclination surface relative to a liquid jet surface on which the nozzles 21 are open is smaller than an angle of the first inner wall surface relative to the liquid jet surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a liquid ejection apparatus that eject liquid from nozzles, and a method for manufacturing a liquid ejection head, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as liquid, and a method for manufacturing an ink jet recording head. [Background technology]

[0002] An inkjet recording head, which is a typical example of a liquid ejection head that ejects liquid droplets, includes, for example, a nozzle and a flow path such as a pressure chamber that communicates with the nozzle, and ejects ink droplets from the nozzle by causing a pressure change in the ink in the pressure chamber using a pressure generating means.

[0003] For example, there is a configuration in which a pressure chamber and a nozzle are connected via a nozzle communication passage, which is a straight hole (see Patent Document 1). Patent Document 1 discloses a configuration in which a flow path forming substrate in which a pressure chamber is formed and a nozzle plate in which a nozzle is formed are joined together with a communication plate sandwiched therebetween, and a nozzle communication passage with a diameter larger than that of the nozzle is provided in this communication plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-124887 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above configuration in which the pressure chamber and the nozzle are connected by a nozzle communicating passage, the opening shapes at the connection between the pressure chamber and the nozzle communicating passage are different, and the opening shapes at the connection between the nozzle communicating passage and the nozzle are also different, so steps are likely to be formed at the connection between the nozzle communicating passage and the pressure chamber and the connection between the nozzle communicating passage and the nozzle, which creates the problem that air bubbles are likely to accumulate near the nozzle communicating passage, for example, at the connection between the nozzle communicating passage and the pressure chamber and the connection between the nozzle communicating passage and the nozzle.

[0006] This problem exists not only in ink jet recording heads, but also in liquid ejection heads that eject various types of liquid. [Means for solving the problem]

[0007] An aspect of the present invention that solves the above-mentioned problem is a liquid jet head comprising: a flow path forming substrate in which a plurality of pressure chambers are arranged side by side in a first direction; and a bonding substrate bonded to one side of the flow path forming substrate, the bonding substrate including at least a nozzle plate in which nozzles connected to the pressure chambers are provided; wherein the bonding substrate is provided with a nozzle communication passage that communicates the pressure chambers with the nozzles; the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction perpendicular to the first direction; at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzles; and the angle of the inclined surface with respect to the liquid jet surface in which the nozzles open is smaller than the angle of the first inner wall surfaces with respect to the liquid jet surface.

[0008] Another aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head of the above aspect.

[0009] and a bonding substrate bonded to one side of the flow path forming substrate, the bonding substrate including at least a nozzle plate having nozzles connected to the pressure chambers, wherein the bonding substrate is provided with nozzle communication passages that communicate the pressure chambers with the nozzles, the nozzle communication passages having a pair of first inner wall surfaces that form wall surfaces in the first direction and a pair of second inner wall surfaces that form wall surfaces in a second direction perpendicular to the first direction, at least one of the second inner wall surfaces including an inclined surface that is inclined such that a length of the nozzle communication passage in the second direction becomes shorter toward the nozzles, and an angle of the inclined surface with respect to a liquid ejection surface into which the nozzles open is smaller than an angle of the first inner wall surface with respect to the liquid ejection surface, wherein the bonding substrate is configured to include a single crystal silicon substrate having a surface with a {100} plane, and the nozzle communication passages are formed by anisotropic wet etching of the single crystal silicon substrate. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view of an ink jet recording head according to a first embodiment. [Figure 2] 1 is a plan view of an ink jet recording head according to a first embodiment. [Figure 3] 1 is a cross-sectional view of an ink jet recording head according to a first embodiment. [Figure 4] 1 is a cross-sectional view of an ink jet recording head according to a first embodiment. [Figure 5] 1 is an enlarged plan view showing a main part of an ink jet recording head according to a first embodiment. [Figure 6] 1 is an enlarged cross-sectional view showing a main part of an ink jet recording head according to a first embodiment. [Figure 7] FIG. 10 is a cross-sectional view of an ink jet recording head according to a second embodiment. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing a main part of an ink jet recording head according to a third embodiment. [Figure 9] FIG. 10 is an enlarged cross-sectional view showing a main part of an ink jet recording head according to a fourth embodiment. [Figure 10] FIG. 10 is an enlarged cross-sectional view of an ink jet recording head according to a fifth embodiment. [Figure 11] FIG. 1 is a diagram illustrating a schematic configuration of a recording apparatus according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below based on an embodiment. However, the following description is of one aspect of the present invention, and the configuration of the present invention can be modified as desired within the scope of the invention. In each drawing, the same components are given the same reference numerals, and duplicated descriptions will be omitted.

[0012] In each figure, X, Y, and Z represent three spatial axes that are orthogonal to one another. In this specification, the directions along these axes are referred to as the X direction, Y direction, and Z direction. In each figure, the direction indicated by the arrow is the positive (+) direction, and the direction opposite the arrow is the negative (-) direction. The Z direction indicates the vertical direction, with the +Z direction pointing vertically downward and the -Z direction pointing vertically upward. Furthermore, the three spatial axes X, Y, and Z, which are not limited to positive and negative directions, will be described as the X axis, Y axis, and Z axis.

[0013] (Embodiment 1) FIG. 1 is an exploded perspective view showing the main configuration of an ink jet recording head, which is an example of a liquid jet head according to a first embodiment of the present invention. FIG. 2 is a plan view of the ink jet recording head as viewed from the -Z direction. FIG. 3 is a cross-sectional view of the ink jet recording head, taken along line AA' in FIG. 2. FIG. 4 is a cross-sectional view of the ink jet recording head, taken along line BB' in FIG. 2. FIG. 5 is an enlarged plan view of a flow path forming substrate and a bonding substrate as viewed from the -Z direction, illustrating pressure chambers and nozzle communication paths. FIG. 6 is an enlarged cross-sectional view showing the vicinity of an ink communication portion of the ink jet recording head.

[0014] As shown in the figure, an ink jet recording head (hereinafter also simply referred to as a recording head) 1, which is an example of a liquid jet head of this embodiment, jets ink as a liquid in the Z axis direction, more specifically in the +Z direction.

[0015] The recording head 1 includes a flow path forming substrate 10 in which ink flow paths through which ink flows are formed. The flow path forming substrate 10 is made of, for example, a single crystal silicon substrate whose surface has a {110} plane orientation, and in this embodiment, a single crystal silicon substrate whose surface has a (110) plane orientation. In other words, the flow path forming substrate 10 is made of a single crystal silicon substrate preferentially oriented in the (110) plane.

[0016] Here, the single crystal silicon substrate having a surface orientation of the {110} plane includes not only a single crystal silicon substrate having a surface orientation of the (110) plane, but also, for example, a single crystal silicon substrate having a surface orientation of the (101), (011), (-110), (-101), (0-11), etc. In other words, the single crystal silicon substrate having a surface orientation of the {110} plane includes a single crystal silicon substrate having a surface orientation equivalent to the (110) plane.

[0017] The material of the flow path forming substrate 10 is not limited to a single crystal silicon substrate having a surface plane orientation of {110}, but may be, for example, a single crystal silicon substrate having a surface plane orientation of {100}, or may be other silicon substrates such as a polycrystalline silicon substrate, an SOI substrate, a glass substrate, or various ceramic substrates.

[0018] In this flow path forming substrate 10, a plurality of pressure chambers 12 that form ink flow paths are arranged in a row along the X-axis direction, which is a first direction that intersects with the Z-axis direction. Adjacent pressure chambers 12 are separated by partition walls 11. The shape of the opening of the pressure chambers 12 is not particularly limited, but for example, is formed into a substantially parallelogram whose length in the Y-axis direction is longer than its length in the X-axis direction in a plan view.

[0019] In this embodiment, the flow path forming substrate 10 is made of a single crystal silicon substrate whose surface has a (110) plane orientation as described above, and each pressure chamber 12 is formed by anisotropic wet etching of the single crystal silicon substrate that becomes the flow path forming substrate 10. Therefore, the opening shape of each pressure chamber 12 is formed into a substantially parallelogram shape, as shown in FIG.

[0020] The first inner wall surface 12a on the long side of each pressure chamber 12 is composed of a first (111) plane perpendicular to the surface of the flow channel forming substrate 10, which is a (110) plane, and the second inner wall surface 12b on the short side is composed of a second (111) plane perpendicular to the (110) plane and intersecting the first (111) plane at a predetermined angle. That is, the first inner wall surface 12a, which is the wall surface in the X-axis direction of the pressure chamber 12, is composed of the first (111) plane, and the second inner wall surface 12b, which is the wall surface in the Y-axis direction, is composed of the second (111) plane.

[0021] The recording head 1 also includes, as ink flow paths, a supply manifold 100 which is a first common liquid chamber common to the plurality of pressure chambers 12, and a circulation manifold 110 which is a second common liquid chamber. The supply manifold 100 is provided on the outer side of the pressure chambers 12 in the -Y direction, and the circulation manifold 110 is provided on the outer side of the pressure chambers 12 in the +Y direction.

[0022] The flow path forming substrate 10 is provided with a first supply manifold section 13 constituting the supply manifold 100 and a first circulation manifold section 14 constituting the circulation manifold 110. The first supply manifold section 13 communicates with a second supply manifold section 32 provided on the communication plate 30 (described later) and a third supply manifold section 42 provided on the protective substrate 40, to form the supply manifold 100, which is a common liquid chamber shared by the multiple pressure chambers 12. The first circulation manifold section 14 communicates with a second circulation manifold section 33 provided on the communication plate 30 (described later) and a third circulation manifold section 43 provided on the protective substrate 40, to form the circulation manifold 110 common to each pressure chamber 12.

[0023] These first supply manifold section 13 and first circulation manifold section 14 are provided continuously in the X-axis direction across the area of ​​the flow path forming substrate 10 in which multiple pressure chambers 12 are formed, and are provided so as to penetrate the flow path forming substrate 10 in the Z-axis direction.

[0024] The flow path forming substrate 10 is also provided with ink supply channels 15 that connect the first supply manifold portion 13 to each pressure chamber 12. The ink supply channels 15 are individually provided for each pressure chamber 12 with a width similar to that of the pressure chamber 12, preferably narrower than that of the pressure chamber 12, and connect the -Y direction end of each pressure chamber 12 to the first supply manifold portion 13 that constitutes the supply manifold 100. Ink in the supply manifold 100 is supplied to each pressure chamber 12 via these ink supply channels 15.

[0025] In this way, the recording head 1 is provided with a supply flow path that includes the supply manifold 100 and the ink supply path 15 and that supplies ink from the supply manifold 100 to each pressure chamber 12 .

[0026] Meanwhile, the circulation manifold 110 is connected to each pressure chamber 12 by ink discharge paths 34 provided in the communication plate 30, which will be described later. The ink in each pressure chamber 12 is discharged to the circulation manifold 110 via these ink discharge paths 34 at a predetermined timing. Although not shown in the figures, the circulation manifold 110 is connected to the supply manifold 100, so that the ink in the circulation manifold 110 can be returned to the supply manifold 100 at a predetermined timing.

[0027] In this way, the recording head 1 is provided with a circulation flow path that includes the circulation manifold 110 and the ink discharge path 34 and that returns the ink discharged from the pressure chambers 12 to the supply manifold 100 .

[0028] In other words, the recording head 1 has an ink flow path that includes these supply flow path and circulation flow path, and is configured to be able to circulate ink within the ink flow path via the pressure chamber 12, and is, for example, a type that is also called a pressure chamber circulation head.

[0029] On the +Z direction side of the flow path forming substrate 10 in which ink flow paths such as the pressure chambers 12 are formed, there is provided a bonding substrate 200 including at least a nozzle plate 20 in which nozzles 21 connected to the pressure chambers 12 are provided. In this embodiment, the bonding substrate 200 is configured by the nozzle plate 20 and a communication plate 30 provided between the nozzle plate 20 and the flow path forming substrate 10. In other words, on the +Z direction side of the flow path forming substrate 10, the communication plate 30 and the nozzle plate 20 that constitute the bonding substrate 200 are stacked in this order.

[0030] A plurality of nozzles 21 corresponding to each pressure chamber 12 are formed in a row on the nozzle plate 20. The shape of the nozzles 21 is not particularly limited, but in this embodiment, the nozzles 21 are formed in a so-called straight shape. That is, the inner diameter of each nozzle 21 is approximately constant along the length of the nozzle 21, which is the Z-axis direction.

[0031] The material of the nozzle plate 20 is not particularly limited, but for example, a relatively inexpensive polycrystalline silicon substrate is preferably used. Furthermore, the method of forming the nozzles 21 is not particularly limited, but when a polycrystalline silicon substrate is used as the nozzle plate 20, it is preferable to form the nozzles 21 by dry etching. This makes it possible to form straight-shaped nozzles 21 in the nozzle plate 20 relatively easily.

[0032] The nozzle plate 20 may be made of a single crystal silicon substrate having a surface orientation of {110} or a single crystal silicon substrate having a surface orientation of {100}.

[0033] Furthermore, the nozzle plate 20 can be made of, for example, an SOI substrate, a glass substrate, various ceramic substrates, or a metal substrate. Examples of metal plates include a stainless steel substrate. Furthermore, the nozzle plate 20 can be made of an organic material such as a polyimide resin.

[0034] However, it is preferable to use a material for the nozzle plate 20 that has a thermal expansion coefficient close to that of the communicating plate 30. This makes it possible to suppress warping of the nozzle plate 20 and the communicating plate 30 due to the difference in thermal expansion coefficient when the temperatures of the nozzle plate 20 and the communicating plate 30 change.

[0035] The communication plate 30 is provided with a plurality of nozzle communication passages 31 that respectively connect each pressure chamber 12 with each nozzle 21. As will be described in detail later, one of the features of the present invention lies in the shape of the nozzle communication passages 31. The communication plate 30 is also provided with a second supply manifold section 32 that, together with the first supply manifold section 13 provided on the flow path forming substrate 10, constitutes a supply manifold 100.

[0036] Furthermore, the communication plate 30 is provided with a second circulation manifold section 33 which, together with the first circulation manifold section 14 provided on the flow path forming substrate 10, constitutes a circulation manifold 110, and an ink discharge path 34 which connects this second circulation manifold section 33 to each pressure chamber 12.

[0037] The second supply manifold section 32, the second circulation manifold section 33, and the ink discharge channels 34 are provided so as to open on the surface of the communicating plate 30 on the -Z direction side, without penetrating the communicating plate 30 in the Z axis direction. The second supply manifold section 32 and the second circulation manifold section 33 are provided continuously in the X axis direction across the region in which the multiple pressure chambers 12 are formed. The ink discharge channels 34 are provided independently for each pressure chamber 12, and connect the +Y direction end of each pressure chamber 12 to the second circulation manifold section 33 that constitutes the circulation manifold 110.

[0038] Here, we will explain in more detail the shape of the nozzle communication passage 31. The nozzle communication passage 31 is provided so as to penetrate the communication plate 30 in the Z-axis direction, and connects each pressure chamber 12 with each nozzle 21. As shown in Fig. 5, the nozzle communication passage 31 is formed by a pair of first inner wall surfaces 31a that form wall surfaces in the X-axis direction, which is a first direction, and a pair of second inner wall surfaces 31b that form wall surfaces in the Y-axis direction, which is a second direction perpendicular to the X-axis direction.

[0039] In this embodiment, the communication plate 30 is formed of a single crystal silicon substrate having a (110) surface orientation, similar to the flow path forming substrate 10, and the nozzle communication passage 31 is formed by anisotropic wet etching of this single crystal silicon substrate.

[0040] For this reason, the opening shape of each nozzle communicating passage 31 is formed into a substantially parallelogram, and the wall surface on the long side of each nozzle communicating passage 31, i.e., the first inner wall surface 31a which is the wall surface in the X-axis direction, is composed of a first (111) plane which is perpendicular to the (110) plane of the surface of the communicating plate 30. Furthermore, the wall surface on the short side of each nozzle communicating passage 31, i.e., the wall surface in the Y-axis direction, is composed of a second inner wall surface 31b which is perpendicular to the (110) plane and intersects with the first (111) plane at a predetermined angle.

[0041] In other words, the first inner wall surface 31a of the nozzle communication passage 31 is configured as a surface that is approximately perpendicular to the liquid ejecting surface where the nozzles 21 open, which in this embodiment is the surface of the nozzle plate 20. That is, the angle θ1 of the first inner wall surface 31a with respect to the liquid ejecting surface is approximately a right angle (see FIG. 4, etc.).

[0042] On the other hand, each second inner wall surface 31b of the nozzle communication passage 31 is an inclined surface that is inclined so that the length of the nozzle communication passage 31 in the Y-axis direction becomes shorter toward the nozzle 21, that is, toward the +Z direction (see FIG. 3). Therefore, the angle θ2 of the second inner wall surface 31b with respect to the liquid ejection surface (in this embodiment, the angle θ2 with respect to the surface of the nozzle plate 20 where the nozzle 21 opens) is smaller than the angle θ1 of the first inner wall surface 31a with respect to the liquid ejection surface. As described above, the second inner wall surface 31b is composed of a second (111) plane that is inclined at a predetermined angle with respect to the first (111) plane. As a result, the inclination angle θ2 of the second inner wall surface 31b with respect to the liquid ejection surface in the Y-axis direction is approximately 30 degrees (see FIG. 6).

[0043] The opening width of the nozzle communicating passage 31 on the pressure chamber 12 side in the X-axis direction is narrower than the opening width of the pressure chamber 12 on the nozzle communicating passage 31 side. Furthermore, the opening width of the nozzle communicating passage 31 on the nozzle 21 side is wider than the opening width of the nozzle 21 on the nozzle communicating passage 31 side.

[0044] In this embodiment, the first inner wall surface 12a of the pressure chamber 12 and the first inner wall surface 31a of the nozzle connecting passage 31 are surfaces that are approximately perpendicular to the liquid ejection surface. That is, in the X-axis direction, the width of the first inner wall surface 12a of the pressure chamber 12 and the nozzle connecting passage 31 is approximately constant over the Z-axis direction. Furthermore, the nozzle 21 is formed in a straight shape as described above.

[0045] 4, the width W1 of the nozzle communication passage 31 is narrower than the width W2 of the pressure chamber 12. The width W1 of the nozzle communication passage 31 is also wider than the opening width W3 of the nozzle 21.

[0046] By connecting each pressure chamber 12 to each nozzle 21 via the nozzle communicating passage 31 having such a shape, it is possible to improve the discharge of air bubbles contained in ink near the nozzle communicating passage 31. Because the second inner wall surface 31b, which is the wall surface of the nozzle communicating passage 31 in the Y-axis direction, which is the ink flow direction, is an inclined surface, it is possible to easily increase the flow rate of ink near the nozzle communicating passage 31. For example, the flow rate of ink near the nozzle communicating passage 31 is also likely to increase during various cleaning operations such as flushing, suction cleaning, and pressure cleaning, or when circulating ink via the circulation manifold 110. This makes it possible to improve the discharge of air bubbles that remain near the nozzle communicating passage 31. In other words, it is possible to prevent air bubbles from remaining near the nozzle communicating passage 31.

[0047] In the communication plate 30 constituting the bonded substrate 200, the nozzle communication passage 31 formed by the first inner wall surface 31a and the second inner wall surface 31b is <111> In this embodiment, the nozzle communication passages 31 are arranged in parallel along the X-axis direction of the communication plate 30, which is the (111) direction.

[0048] When the nozzle communicating passages 31 are arranged in a row in the (111) direction, the first inner wall surfaces 31a, which are approximately perpendicular to the liquid ejection surface, can be formed relatively easily by anisotropic wet etching of the single crystal silicon substrate that will become the communicating plate 30. Furthermore, because the first inner wall surfaces 31a are approximately perpendicular to the liquid ejection surface, the multiple nozzle communicating passages 31 arranged in a row can be arranged at high density.

[0049] In addition, the above <111> The direction includes not only the (111) direction but also, for example, the (-111) direction, the (1-11) direction, the (11-1) direction, etc. <111> The directions include directions equivalent to the (111) direction.

[0050] In this embodiment, the communicating plate 30 is formed of a single crystal silicon substrate whose surface has a (110) plane orientation, but there are no particular limitations on the material of the communicating plate 30. The communicating plate 30 can also be made of other silicon substrates such as polycrystalline silicon substrates, SOI substrates, etc.

[0051] However, it is preferable that the communicating plate 30 be made of a material whose thermal expansion coefficient is close to that of the flow path forming substrate 10. This makes it possible to suppress warping of the flow path forming substrate 10 and the communicating plate 30 due to the difference in thermal expansion coefficient when the temperatures of the flow path forming substrate 10 and the communicating plate 30 change.

[0052] Similarly to the nozzle communication passages 31, the second supply manifold portion 32, the second circulation manifold portion 33, and the ink discharge passages 34 provided in the communication plate 30 are also formed by anisotropic wet etching of the single crystal silicon substrate that will become the communication plate 30. Of course, the method for forming the nozzle communication passages 31, the second supply manifold portion 32, the second circulation manifold portion 33, and the ink discharge passages 34 is not particularly limited, and they may also be formed by dry etching, for example.

[0053] Furthermore, the method for bonding the nozzle plate 20 and the communicating plate 30 that constitute the bonded substrate 200 is not particularly limited, but it is preferable that they be bonded by room temperature bonding. That is, it is preferable that the nozzle plate 20 and the communicating plate 30 are bonded in close contact with each other without an adhesive layer or the like being interposed between them. This further prevents air bubbles from remaining in the connection portion between the nozzle communication passage 31 and the nozzle 21, that is, the bonded portion between the communicating plate 30 and the nozzle plate 20.

[0054] In this embodiment, the nozzle plate 20 and the communication plate 30 are bonded to form the bonded substrate 200, but the bonded substrate 200 may be composed of a single substrate. For example, the bonded substrate 200 may be formed of an SOI substrate, and the nozzle plate 20 made of a polycrystalline silicon substrate or the like and the communication plate 30 made of a single crystal silicon substrate with a {110} plane surface may be formed as an integrated component.

[0055] 6, a flow path protective film 150 is provided on the inner surface of the ink flow path including each nozzle communication path 31. The flow path protective film 150 does not necessarily have to be provided over the entire surface of the ink flow path, but it is preferable that it be provided at least on the surface of the second inner wall surface 31b of the nozzle communication path 31.

[0056] Because the second inner wall surface 31b is an inclined surface, there is a risk that the communicating plate 30, which is a silicon substrate, will be more likely to be dissolved by the ink as the ink flow rate increases near the nozzle communicating passage 31. However, by providing the flow path protective film 150 on the inner surface of the nozzle communicating passage 31, particularly on the surface of the second inner wall surface 31b, which is an inclined surface, it is possible to prevent the communicating plate 30 from being dissolved by the ink.

[0057] The flow channel protective film 150 may be formed, for example, as a single layer of a liquid-resistant single material or composite material, or as a laminated film of multiple materials. Liquid resistance here refers to etching resistance against ink, which is a basic or acidic liquid. Examples of liquid-resistant materials used for the flow channel protective film 150 include oxides or nitrides of elements selected from the group consisting of tantalum (Ta), titanium (Ti), zirconium (Zr), niobium (Nb), vanadium (V), hafnium (Hf), silicon (Si), aluminum (Al), tungsten (W), and yttrium (Y). In other words, the flow channel protective film 150 may be formed as a single layer of a single material or composite material containing an oxide or nitride of the above elements, or as a laminated film of multiple materials. Of course, the material for the flow channel protective film 150 is not limited to these examples, and any material capable of suppressing dissolution of the communication plate 30 by ink may be used.

[0058] The method for forming the flow path protective film 150 is not particularly limited, but it can be formed by, for example, atomic layer deposition (ALD). By using atomic layer deposition, the flow path protective film 150 can be formed in a dense state with high film density, and adhesion to objects such as the communication plate 30 is very good.

[0059] Incidentally, on the surface of the flow channel forming substrate 10 opposite to the bonding substrate 200, i.e., on the surface on the −Z direction side, a piezoelectric actuator 300 is provided via a vibration plate 50. The piezoelectric actuator 300 is provided corresponding to each pressure chamber 12.

[0060] In the recording head 1, the piezoelectric actuator 300 is driven to flex and deform the vibration plate 50, and this deformation causes a pressure change in the ink inside the pressure chamber 12, thereby performing a recording operation in which ink is ejected from the nozzle 21. Note that the configurations of the vibration plate 50 and the piezoelectric actuator 300 are not particularly limited, and known technology may be applied, so detailed explanation will be omitted.

[0061] A protective substrate 40 is further bonded to the surface of the flow path forming substrate 10 on the -Z direction side with an adhesive or the like. The protective substrate 40 has a holding portion 41 which is a space that protects the piezoelectric actuators 300. The holding portion 41 is formed to have a size that can accommodate multiple piezoelectric actuators 300 arranged side by side in the X axis direction.

[0062] The protective substrate 40 is also provided with a third supply manifold section 42 that communicates with the first supply manifold section 13 provided on the flow path forming substrate 10 to form the supply manifold 100. Similar to the first supply manifold section 13, the third supply manifold section 42 is provided continuously over an area corresponding to the plurality of pressure chambers 12 arranged in a row in the X-axis direction.

[0063] Furthermore, the protective substrate 40 is provided with a third circulation manifold section 43 that communicates with the first circulation manifold section 14 provided on the flow path forming substrate 10 to form the circulation manifold 110. Similar to the first circulation manifold section 14, this third circulation manifold section 43 is provided continuously over an area corresponding to the plurality of pressure chambers 12 arranged in a row in the X-axis direction.

[0064] Furthermore, the protective substrate 40 is provided with a through-hole 44 penetrating in the Z-axis direction in an area facing the ink discharge path 34 of the communicating plate 30. Although not shown in the drawings, the lead electrodes drawn from each piezoelectric actuator 300 extend into the through-hole 44, and the lead electrodes are connected to external wiring within the through-hole 44.

[0065] In the recording head 1 of this embodiment, ink is taken in from an external ink supply means (not shown), and the ink flow paths from the supply manifold 100 and circulation manifold 110 to the nozzles 21 are filled with ink. Then, a voltage is applied via external wiring to each piezoelectric actuator 300 corresponding to a pressure chamber 12. This causes the piezoelectric actuator 300 and the diaphragm 50 to bend and deform, increasing the pressure inside each pressure chamber 12 and causing ink droplets to be ejected from each nozzle 21.

[0066] As described above, in the recording head 1 according to this embodiment, the nozzle communication passage 31 that connects the pressure chamber 12 and the nozzle 21 is provided in the communication plate 30 that constitutes the bonding substrate 200, and the nozzle communication passage 31 has a pair of first inner wall surfaces 31a that form the wall surfaces in the X direction and a pair of second inner wall surfaces 31b that form the wall surfaces in the Y axis direction that is perpendicular to the X axis direction, and at least one of the second inner wall surfaces 31b includes an inclined surface that is inclined so that the length of the nozzle communication passage 31 in the Y axis direction becomes shorter toward the nozzle 21, and the angle of the inclined surface with respect to the liquid ejection surface into which the nozzle 21 opens is smaller than the angle of the first inner wall surface 31a with respect to the liquid ejection surface.

[0067] This increases the ink flow velocity near the nozzle communicating passage 31. This makes it possible to prevent air bubbles from stagnating near the nozzle communicating passage 31. Because the ink flow velocity increases, air bubbles stagnating near the nozzle communicating passage 31 can be appropriately removed by, for example, performing various cleaning operations or circulating ink.

[0068] Furthermore, the communication plate 30 constituting the bonded substrate 200 is preferably made of a single crystal silicon substrate with a surface orientation of {110}. The nozzle communication passages 31 are preferably formed by anisotropically wet etching the communication plate 30. The plurality of nozzle communication passages 31 are formed by etching the communication plate 30 constituting the bonded substrate 200. <111> This makes it relatively easy to form the nozzle communication passages 31 defined by the first inner wall surfaces 31a that are substantially perpendicular to the liquid ejection surface, and makes it possible to arrange multiple nozzle communication passages 31 at high density.

[0069] Furthermore, the second inner wall surface 31b, which is an inclined surface, is preferably formed as a {111} plane that intersects with the {110} plane of the communication plate 30 that constitutes the bonded substrate 200. This makes it possible to relatively easily form the nozzle communication passage 31 in the desired shape by anisotropically wet etching the communication plate 30 made of a single crystal silicon substrate.

[0070] Furthermore, the recording head 1 preferably has a supply flow path that includes a supply manifold 100 that communicates with the multiple pressure chambers 12 and that supplies ink from the supply manifold 100 to each pressure chamber 12, and a circulation flow path that includes a circulation manifold 110 that communicates with the multiple pressure chambers 12 and that returns ink that is discharged from each pressure chamber 12 to the circulation manifold 110 to the supply manifold. In the case of a recording head 1 that has such a supply flow path and circulation flow path, air bubbles near the nozzle communication paths 31 can be more appropriately removed by circulating ink.

[0071] If the recording head 1 is capable of circulating ink, it is preferable that each of the second inner wall surfaces 31b of the nozzle communicating passages 31 includes an inclined surface. This makes it possible to more effectively remove air bubbles contained in the ink near the nozzle communicating passages 31 when circulating ink.

[0072] Furthermore, it is preferable that the opening width of the nozzle communicating passage 31 on the pressure chamber 12 side is narrower than the opening width of the pressure chamber 12 on the nozzle communicating passage 31 side. This makes it possible to ensure a sufficient volume for the pressure chamber 12 while generating a sufficient flow of ink in the nozzle communicating passage 31. Furthermore, it is preferable that the opening width of the nozzle communicating passage 31 on the nozzle 21 side is wider than the opening width of the nozzle 21 on the nozzle communicating passage 31 side. This makes it possible to further prevent bubbles from stagnating near the boundary between the nozzle 21 and the nozzle communicating passage 31.

[0073] The bonding substrate 200 preferably includes a nozzle plate 20 made of a polycrystalline silicon substrate on which nozzles 21 are formed, the nozzle plate 20 being provided on the surface opposite to the flow path forming substrate 10. This allows the nozzles 21 to be formed relatively easily by dry etching or the like, and also reduces the manufacturing cost of the nozzle plate 20.

[0074] The bonding substrate 200 may also include a nozzle plate 20 made of a single crystal silicon substrate having a {100} or {110} plane, on the surface opposite to the flow path forming substrate 10, where the nozzle 21 is formed. This allows the nozzle 21 to be formed relatively easily by anisotropic wet etching or dry etching.

[0075] Furthermore, the bonding substrate 200 may be made of an SOI substrate and include the nozzle plate 20 and a communication plate 30 that is provided on the flow path forming substrate 10 side of the nozzle plate 20 and is made of a single crystal silicon substrate with a {110} plane surface and in which the nozzle communication paths 31 are formed. With this configuration, the bonding substrate 200 can be formed relatively easily and inexpensively.

[0076] Furthermore, it is preferable that the surface of the second inner wall surface 31b, which is an inclined surface, is formed with a flow path protective film 150. This can prevent the communication plate 30, which is made of a silicon substrate, from being dissolved by the ink.

[0077] Furthermore, when the bonded substrate 200 is configured to include a communicating plate 30 in which the nozzle communicating passages 31 are formed and a nozzle plate 20 in which the nozzles 21 are formed, and the bonded substrate 200 is formed by bonding the communicating plate 30 and the nozzle plate 20, it is preferable to bond the communicating plate 30 and the nozzle plate 20 by room temperature bonding. This makes it possible to further suppress the accumulation of air bubbles at the connection portions between the nozzle communicating passages 31 and the nozzles 21.

[0078] As described above, the recording head 1 according to this embodiment is configured so that ink is supplied from the supply manifold 100 to each pressure chamber 12 via the ink supply path 15, the ink in each pressure chamber 12 is discharged to the circulation manifold 110 via the ink discharge path 34, and the ink is returned from the circulation manifold 110 to the supply manifold 100. However, the configuration of the recording head 1 is not limited to this, and it is also possible to reverse the above and supply ink to each pressure chamber 12 from the circulation manifold 110 via the ink discharge path 34, discharge ink from each pressure chamber 12 to the supply manifold 100 via the ink supply path 15, and return the ink in the supply manifold 100 to the circulation manifold 110.

[0079] (Embodiment 2) 7 is a cross-sectional view of a recording head according to embodiment 2. In the figure, the same members are given the same reference numerals and redundant explanations will be omitted.

[0080] This embodiment is an example in which the recording head 1 has two rows of pressure chambers 12. That is, in the recording head 1 according to this embodiment, similar to the first embodiment, a plurality of pressure chambers 12 are arranged side by side in the X-axis direction, and two rows of such pressure chambers 12 are provided in the Y-axis direction. Then, as shown in Fig. 7, two pressure chambers 12 are arranged side by side in the Y-axis direction in the flow path forming substrate 10.

[0081] Two supply manifolds 100A and 100B are provided corresponding to the rows of pressure chambers 12, and the pressure chambers 12 in each row are connected to the corresponding supply manifolds 100A and 100B via ink supply paths 15.

[0082] A circulation manifold 110A is provided in the center of the flow path forming substrate 10 in the Y-axis direction, i.e., in the region between the two rows of pressure chambers 12. This circulation manifold 110A is provided in common to each of the two rows of pressure chambers 12, and is connected to each of the two rows of pressure chambers 12 via ink discharge channels 34.

[0083] During ink circulation, ink is discharged from the pressure chambers 12 in each row through the ink discharge passage 34 to the circulation manifold 110A, and the ink in this circulation manifold 110A is returned to each of the supply manifolds 100A and 100B.

[0084] In this embodiment, the second inner wall surface 31b of each nozzle connecting passage 31 is an inclined surface that is inclined so that the length of the nozzle connecting passage 31 in the Y-axis direction becomes shorter toward the nozzle 21, as in embodiment 1.

[0085] This increases the flow rate of ink near the nozzle communication passage 31, and similarly to the first embodiment, it is possible to prevent air bubbles from stagnating near the nozzle communication passage 31.

[0086] In this embodiment, the circulation manifold 110A is provided in common to the two rows of pressure chambers 12, but of course it may be provided independently for each row of pressure chambers 12. Furthermore, in this embodiment, two supply manifolds 100A, 100B are provided corresponding to each row of pressure chambers 12, but the supply manifold may be provided in common to the two rows of pressure chambers 12. For example, a supply manifold may be formed continuously so as to surround three sides of the pressure chambers 12 arranged in two rows, and be common to each of the pressure chambers 12 in the two rows.

[0087] (Embodiment 3) 8 is an enlarged cross-sectional view showing the vicinity of the nozzle communication portion of a recording head according to embodiment 3. This embodiment is a modified example of the bonding substrate, and is similar to embodiment 1 except for the shape of the nozzle. Note that the same members in the figures are given the same reference numerals, and redundant explanations will be omitted.

[0088] As shown in Figure 8, the nozzle 21A of this embodiment is composed of a first nozzle section 22 provided on the +Z direction side of the nozzle plate 20A, and a second nozzle section 23 provided on the -Z direction side of the nozzle plate 20A and having a larger diameter than the first nozzle section 22.

[0089] The bonded substrate 200A is formed by bonding the nozzle plate 20A, in which the nozzles 21A are formed, and the communication plate 30 together with an adhesive or the like. However, the method for bonding the nozzle plate 20A and the communication plate 30 is not particularly limited.

[0090] In this embodiment, as in the first embodiment, the second inner wall surface 31b of each nozzle communicating passage 31 is an inclined surface that is inclined so that the length of the nozzle communicating passage 31 in the Y-axis direction becomes shorter toward the nozzle 21. The inclination angle θ2 of the second inner wall surface 31b with respect to the liquid ejection surface in the Y-axis direction is approximately 30 degrees. This increases the flow rate of ink near the nozzle communicating passage 31, and, as in the first embodiment, makes it possible to prevent air bubbles from stagnating near the nozzle communicating passage 31.

[0091] (Embodiment 4) 9 is an enlarged cross-sectional view showing the vicinity of the nozzle communication portion of the recording head according to embodiment 4. This embodiment is a modified example of the bonding substrate, and is similar to embodiment 1 except that the bonding substrate is composed of a single substrate. Note that the same members in the figures are given the same reference numerals, and redundant explanations will be omitted.

[0092] 9, the bonded substrate 200B according to this embodiment is made of a single substrate, and the nozzles 21B are formed continuously from the nozzle connecting passages 31. Specifically, the bonded substrate 200B is made of a single crystal silicon substrate with a surface plane orientation of {110}, and the nozzles 21B, together with the nozzle connecting passages 31, are formed by anisotropic wet etching of the single crystal silicon substrate. For this reason, the inner diameter of the nozzles 21B becomes smaller towards the liquid ejection surface, that is, the surface side of the bonded substrate 200B where the nozzles 21B open.

[0093] In this embodiment, as in the first embodiment, the second inner wall surface 31b of each nozzle communicating passage 31 is an inclined surface that is inclined so that the length of the nozzle communicating passage 31 in the Y-axis direction becomes shorter toward the nozzle 21B. The inclination angle θ2 of the second inner wall surface 31b with respect to the liquid ejection surface in the Y-axis direction is approximately 30 degrees. This increases the flow rate of ink near the nozzle communicating passage 31, and, as in the first embodiment, makes it possible to prevent air bubbles from stagnating near the nozzle communicating passage 31.

[0094] (Embodiment 5) 10 is a cross-sectional view of a recording head according to embodiment 5. This embodiment is a modified example of the nozzle communication portion, and is otherwise similar to embodiment 1 except that the recording head does not have a circulation flow path. Note that the same members in the figures are given the same reference numerals, and redundant explanations will be omitted.

[0095] As shown in FIG. 10, the recording head 1 according to this embodiment does not include a circulation manifold or an ink discharge path that constitutes a circulation flow path, and all of the ink supplied from the ink supply path 15 to each pressure chamber 12 is ejected from the nozzle 21.

[0096] In the recording head 1 of this embodiment, the second inner wall surface 31b of each nozzle connecting passage 31 is an inclined surface that is inclined so that the length of the nozzle connecting passage 31 in the Y-axis direction becomes shorter toward the nozzle 21, as in embodiment 1.

[0097] However, while in the above-described embodiment, both of the two second inner wall surfaces 31b in the Y-axis direction are inclined surfaces, in this embodiment, only one of the second inner wall surfaces 31b is inclined. Specifically, only the second inner wall surface 311 (31b) located on the ink supply path 15 side is inclined, and the second inner wall surface 312 (31b) located on the opposite side from the ink supply path 15 is a surface that is approximately perpendicular to the surface of the nozzle plate 20, which is the liquid ejection surface. In other words, the angle θ3 of the second inner wall surface 311 (31b) with respect to the liquid ejection surface is smaller than the angle θ4 of the second inner wall surface 312 (31b) with respect to the liquid ejection surface.

[0098] In this embodiment, too, the second inner wall surface 311 (31b) of each nozzle connecting passage 31 is an inclined surface, which increases the flow rate of ink near the nozzle connecting passage 31, and similar to embodiment 1, it is possible to suppress stagnation of air bubbles near the nozzle connecting passage 31.

[0099] In the recording head 1 of this embodiment, which does not have a circulation flow path, if each of the second inner wall surfaces 31b is an inclined surface, air bubbles are likely to accumulate near the second inner wall surface 312 (31b), so it is preferable that only the second inner wall surface 311 (31b) is an inclined surface.

[0100] (Other embodiments) Although the embodiments of the present invention have been described above, the basic configuration of the present invention is not limited to those described above.

[0101] For example, in the above embodiment, a configuration was given in which the entire surface of the second inner wall surface 31b of the nozzle communication passage 31 is an inclined surface, but the configuration of the second inner wall surface 31b is not limited to this. It is preferable that the entire surface of the second inner wall surface 31b is an inclined surface, but it is also possible for only a portion of the surface to be an inclined surface.

[0102] Furthermore, in each of the above-described embodiments, the main components of the recording head 1 are exemplified as a flow path forming substrate 10, a bonding substrate 200 consisting of a nozzle plate 20 and a communicating plate 30, etc., and a protective substrate 40, but of course the recording head 1 may be configured to include other substrates.

[0103] The ink jet recording head 1 of each of these embodiments is mounted on an ink jet recording apparatus I, which is an example of a liquid ejecting apparatus. Figure 11 is a schematic diagram showing an example of the ink jet recording apparatus I.

[0104] In the ink jet recording apparatus I shown in Fig. 11, a recording head 1 is provided with a detachable cartridge 2 constituting an ink supply means, and is mounted on a carriage 3. The carriage 3 on which the recording head 1 is mounted is provided so as to be movable in the axial direction of a carriage shaft 5 attached to the apparatus main body 4.

[0105] The driving force of the drive motor 6 is transmitted to the carriage 3 via multiple gears and a timing belt 7 (not shown), causing the carriage 3 carrying the recording head 1 to move along the carriage shaft 5. Meanwhile, the device body 4 is provided with a transport roller 8 as a transport means, and a recording sheet S, which is a recording medium such as paper, is transported by the transport roller 8. Note that the transport means for transporting the recording sheet S is not limited to the transport roller 8, and may be a belt, a drum, or the like.

[0106] In such an inkjet recording device I, the recording sheet S is transported in the X direction relative to the recording head 1, and the carriage 3 is moved back and forth along the Y axis relative to the recording sheet S, while ink droplets are ejected from the recording head 1, causing the ink droplets to land over almost the entire surface of the recording sheet S, thereby performing so-called printing.

[0107] Furthermore, in the above-described inkjet recording apparatus I, the recording head 1 is mounted on a carriage 3 and moves back and forth in the Y direction, which is the main scanning direction, but the configuration of the inkjet recording apparatus is not limited to this. The inkjet recording apparatus may be, for example, a so-called line-type recording apparatus in which the recording head 1 is fixed and printing is performed simply by moving a recording sheet S, such as paper, in the X direction, which is the sub-scanning direction. The present invention can also be applied to inkjet recording apparatuses with such a configuration.

[0108] In the above embodiment, an inkjet recording head is used as an example of a liquid jet head, and an inkjet recording device is used as an example of a liquid jet device. However, the present invention is directed to a wide range of liquid jet heads and liquid jet devices, and can of course be applied to liquid jet heads and liquid jet devices that jet liquids other than ink. Examples of other liquid jet heads include various recording heads used in image recording devices such as printers, colorant jet heads used in manufacturing color filters for liquid crystal displays, electrode material jet heads used in forming electrodes for organic EL displays, FEDs (field emission displays), and bioorganic material jet heads used in manufacturing biochips, and the present invention can also be applied to liquid jet devices equipped with such liquid jet heads. [Explanation of symbols]

[0109] I...inkjet recording apparatus (liquid ejection apparatus), 1...inkjet recording head (liquid ejection head), 2...cartridge, 3...carriage, 4...apparatus main body, 5...carriage shaft, 6...drive motor, 7...timing belt, 8...transport roller, 10...flow path forming substrate, 11...partition wall, 12...pressure chamber, 13...first supply manifold section, 14...first circulation manifold section, 15...ink supply path, 20...nozzle plate, 21...nozzle, 22...first nozzle section, 23...second nozzle section, 30...communicating plate, 31...nozzle communicating path , 31a...first inner wall surface, 31b...second inner wall surface, 32...second supply manifold portion, 33...second circulation manifold portion, 34...ink discharge path, 40...protective substrate, 41...holding portion, 42...third supply manifold portion, 43...third circulation manifold portion, 44...through hole, 50...vibration plate, 100...supply manifold, 110...circulation manifold, 150...flow path protective film, 200...bonding substrate, 300...piezoelectric actuator, 311(31b)...second inner wall surface, 312(31a)...first inner wall surface, S...recording sheet

Claims

1. a flow path forming substrate on which a plurality of pressure chambers are arranged in a first direction; A nozzle is bonded to one surface of the flow path forming substrate and is provided with a nozzle connected to the pressure chamber. a bonding substrate including at least a filter plate, a nozzle communication passage that communicates the pressure chamber with the nozzle is provided in the bonding substrate; the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction that is perpendicular to the first direction, at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzle, an angle of the inclined surface with respect to the liquid ejection surface on which the nozzle opens is smaller than an angle of the first inner wall surface with respect to the liquid ejection surface, The opening width of the nozzle communication passage on the pressure chamber side is narrower than the opening width of the pressure chamber on the nozzle communication passage side. A liquid jet head characterized by:

2. a flow path forming substrate on which a plurality of pressure chambers are arranged in a first direction; a bonding substrate bonded to one surface of the flow path forming substrate, the bonding substrate including at least a nozzle plate on which nozzles connected to the pressure chambers are provided, a nozzle communication passage that communicates the pressure chamber with the nozzle is provided in the bonding substrate; the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction that is perpendicular to the first direction, at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzle, an angle of the inclined surface with respect to the liquid ejection surface on which the nozzle opens is smaller than an angle of the first inner wall surface with respect to the liquid ejection surface, The bonding substrate includes a nozzle plate made of a polycrystalline silicon substrate on the surface opposite to the flow path forming substrate, on which the nozzles are formed. A liquid jet head characterized by:

3. a flow path forming substrate on which a plurality of pressure chambers are arranged in a first direction; a bonding substrate bonded to one surface of the flow path forming substrate, the bonding substrate including at least a nozzle plate on which nozzles connected to the pressure chambers are provided, a nozzle communication passage that communicates the pressure chamber with the nozzle is provided in the bonding substrate; the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction that is perpendicular to the first direction, at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzle, an angle of the inclined surface with respect to the liquid ejection surface on which the nozzle opens is smaller than an angle of the first inner wall surface with respect to the liquid ejection surface, The bonding substrate includes a nozzle plate formed on a surface opposite to the flow path forming substrate, the nozzle plate being made of a single crystal silicon substrate having a {100} or {110} plane. A liquid jet head characterized by:

4. a flow path forming substrate on which a plurality of pressure chambers are arranged in a first direction; a bonding substrate bonded to one surface of the flow path forming substrate, the bonding substrate including at least a nozzle plate on which nozzles connected to the pressure chambers are provided, a nozzle communication passage that communicates the pressure chamber with the nozzle is provided in the bonding substrate; the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction that is perpendicular to the first direction, at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzle, an angle of the inclined surface with respect to the liquid ejection surface on which the nozzle opens is smaller than an angle of the first inner wall surface with respect to the liquid ejection surface, A flow path protection film is formed on the surface of the inclined surface. A liquid jet head characterized by:

5. a flow path forming substrate on which a plurality of pressure chambers are arranged in a first direction; a bonding substrate bonded to one surface of the flow path forming substrate, the bonding substrate including a nozzle plate in which nozzles connected to the pressure chambers are formed, and a communication plate in which nozzle communication paths that communicate the pressure chambers with the nozzles are formed, the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction that is perpendicular to the first direction, at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzle, The angle of the inclined surface with respect to the liquid ejection surface on which the nozzle opens is smaller than the angle of the first inner wall surface with respect to the liquid ejection surface. A liquid jet head characterized by:

6. The liquid jet head according to any one of claims 1 to 5, The bonding substrate in which the nozzle communication passage is provided is made of a single crystal silicon substrate whose surface has a {110} plane orientation. A liquid jet head characterized by:

7. The liquid jet head according to claim 6, The nozzle communication paths are arranged in parallel along the <111> direction of the bonded substrate. A liquid jet head characterized by:

8. 8. The liquid jet head according to claim 6, The inclined surface is a {111} surface that intersects with the {110} surface of the bonded substrate. A liquid jet head characterized by:

9. The liquid jet head according to any one of claims 1 to 8, a supply flow path including a first common liquid chamber communicating with the plurality of pressure chambers, for supplying liquid from the first common liquid chamber to each pressure chamber; a circulation flow path including a second common liquid chamber communicating with the plurality of pressure chambers, for returning liquid discharged from each pressure chamber to the second common liquid chamber to the first common liquid chamber; A liquid jet head characterized by:

10. The liquid jet head according to claim 9, Each of the second inner wall surfaces includes the inclined surface. A liquid jet head characterized by:

11. A liquid jet head according to any one of claims 2 to 5 and claims 6 to 10 that do not cite claim 1, The opening width of the nozzle communication passage on the pressure chamber side is narrower than the opening width of the pressure chamber on the nozzle communication passage side. A liquid jet head characterized by:

12. The liquid jet head according to any one of claims 1 to 11, The nozzle communication passage has an opening width on the nozzle side that is wider than the opening width of the nozzle on the nozzle communication passage side. A liquid jet head characterized by:

13. The liquid jet head according to any one of claims 1, 4 to 5, and 6 to 12 that do not cite claim 3, The bonding substrate includes a nozzle plate made of a polycrystalline silicon substrate on the surface opposite to the flow path forming substrate, on which the nozzles are formed. A liquid jet head characterized by:

14. A liquid jet head according to any one of claims 1, 4 to 5, and 6 to 12 that do not cite claim 2, The bonding substrate includes a nozzle plate formed on a surface opposite to the flow path forming substrate, the nozzle plate being made of a single crystal silicon substrate having a {100} or {110} plane. A liquid jet head characterized by:

15. The liquid jet head according to any one of claims 2 to 3 and claims 13 to 14, which do not cite claim 5, The bonding substrate is made of an SOI substrate and includes the nozzle plate and a communication plate provided on the flow path forming substrate side of the nozzle plate, the communication plate being made of a single crystal silicon substrate with a {110} plane surface and having the nozzle communication path formed therein. A liquid jet head characterized by:

16. A liquid jet head according to any one of claims 1 to 3, claim 5, and claims 6 to 15 that do not cite claim 4, A flow path protection film is formed on the surface of the inclined surface. A liquid jet head characterized by:

17. The liquid jet head according to any one of claims 1 to 16, The inner diameter of the nozzle is substantially constant along the length of the nozzle. A liquid jet head characterized by:

18. The liquid jet head according to any one of claims 1 to 16, The inner diameter of the nozzle is smaller toward the liquid ejection surface. A liquid jet head characterized by:

19. The liquid jet head according to any one of claims 1 to 18 is provided. A liquid ejection device characterized by:

20. a flow path forming substrate on which a plurality of pressure chambers are arranged in a first direction; a bonding substrate bonded to one surface of the flow path forming substrate and including at least a nozzle plate on which nozzles connected to the pressure chambers are provided, a nozzle communication passage that communicates the pressure chamber with the nozzle is provided in the bonding substrate; the nozzle communication passage has a pair of first inner wall surfaces that form wall surfaces in the first direction, and a pair of second inner wall surfaces that form wall surfaces in a second direction that is perpendicular to the first direction, at least one of the second inner wall surfaces includes an inclined surface that is inclined so that the length of the nozzle communication passage in the second direction becomes shorter toward the nozzle, a method for manufacturing a liquid ejection head, wherein an angle of the inclined surface with respect to a liquid ejection surface on which the nozzles open is smaller than an angle of the first inner wall surface with respect to the liquid ejection surface, the bonding substrate is configured to include a single crystal silicon substrate having a {100} plane surface, forming the nozzle communication passage by anisotropic wet etching the single crystal silicon substrate; the bonding substrate includes a communication plate in which the nozzle communication passage is formed and a nozzle plate in which the nozzle is formed, The communication plate and the nozzle plate are bonded by room temperature bonding.

10. A method for manufacturing a liquid jet head, comprising:

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