Liquid ejection head and method of manufacturing the same

Abstract

To provide a liquid ejection head in which concentration and adhesion of liquid in a channel formed in an opening diameter conversion plate are suppressed, and to provide a method of manufacturing the same.SOLUTION: And an opening-diameter converting plate 201 that includes a third face 213 and a fourth face 214 that is a back face of the third face, and in which a first opening 211 that is connected to the supply opening and has a first opening width is formed in the third face and a second opening 212 that communicates with the first opening and has a second opening width is formed in the fourth face. 104, in the liquid ejection head in which the second opening width is larger than the first opening width in the second direction orthogonal to the first direction, the opening diameter conversion plate is provided with the supply connection flow path 202 that connects the first opening and the second opening, and the wall surface of the supply connection flow path includes the inclined portion 203 inclined with respect to the first direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a method for manufacturing the same. [Background technology]

[0002] A liquid ejection device is equipped with a liquid ejection head for ejecting liquid, and the liquid ejection device achieves a desired purpose by ejecting liquid. For example, in an inkjet recording device, an inkjet recording head, which is a liquid ejection head, is mounted on a carriage, and ink is ejected from an ejection element substrate provided in the inkjet recording head to record images, characters, etc. on a recording medium. The liquid ejected from the ejection element substrate is supplied from a liquid reservoir provided in the liquid ejection device or the liquid ejection head. While the liquid supplied from the liquid reservoir passes through a large-diameter flow path, the ejection element substrate has a fine flow path structure, so it is necessary to collect the liquid from the large-diameter flow path to the fine ejection element substrate.

[0003] Patent Document 1 discloses a liquid ejection head having an aperture diameter conversion plate for converting the aperture diameter from a large-diameter flow path to a small flow path in an ejection element substrate. The aperture diameter conversion plate has a first aperture connected to the ejection element substrate, a second aperture for supplying liquid to the aperture diameter conversion plate, and a connecting flow path connecting the first aperture and the second aperture, and the aperture width of the second aperture is configured to be larger than the aperture width of the first aperture. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-142533 Summary of the Invention [Problem to be solved by the invention]

[0005] Because the ejection ports of the ejection element substrate are exposed to the outside air, the liquid inside the ejection element substrate evaporates and becomes concentrated, and as this concentration progresses, there is a concern that ejection defects may occur. Because the aperture diameter conversion plate is directly connected to the ejection element substrate, in other words, because the aperture diameter conversion plate is located near the ejection ports, the connecting flow path connecting the second opening and the first opening must have a shape that makes it difficult for the liquid to become concentrated.

[0006] However, in the aperture diameter conversion plate described in Patent Document 1, the wall surface of the connecting flow path connecting the second aperture and the first aperture does not have an inclined portion but is curved, which means that liquid tends to accumulate at the bent portion, and there is a risk that the liquid will concentrate and solidify.

[0007] In view of the above-mentioned problems, it is an object of the present invention to provide a liquid ejection head that suppresses concentration and solidification of liquid in flow paths formed in an opening diameter conversion plate, and a method for manufacturing the same. [Means for solving the problem]

[0008] The liquid ejection head of the present invention comprises: an ejection element substrate having a first surface and a second surface that is the reverse side of the first surface, in which an ejection port for ejecting liquid is formed on the first surface, and a supply opening for supplying liquid to the ejection port is formed on the second surface; and an aperture diameter conversion plate having a third surface and a fourth surface that is the reverse side of the third surface, in which a first opening that is connected to the supply opening and has a first opening width is formed on the third surface, and a second opening that is connected to the first opening and has a second opening width is formed on the fourth surface, wherein the ejection element substrate and the aperture diameter conversion plate are stacked in a first direction, and in a second direction perpendicular to the first direction, the second opening width is larger than the first opening width, and a supply connection flow path that connects the first opening and the second opening is formed in the aperture diameter conversion plate, and a wall surface of the supply connection flow path includes an inclined portion that is inclined with respect to the first direction. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a liquid ejection head that suppresses adhesion of liquid in a flow path formed in an opening diameter conversion plate, and a method for manufacturing the same. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. [Figure 2] FIG. 2 is a cross-sectional schematic view of a liquid ejection head. [Figure 3] FIG. 2 is an exploded cross-sectional view of a liquid ejection head. [Figure 4] FIG. [Figure 5] 5A to 5C are schematic diagrams showing a manufacturing process of the opening diameter conversion plate. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the subject matter of the present invention, and not all combinations of features described in the embodiments are necessarily essential to the solution of the present invention. Note that the same reference numerals are used to designate the same components.

[0012] The liquid ejection head according to this embodiment is an inkjet head that ejects ink, but is not limited to this as long as it ejects liquid. Since ink tends to solidify inside the opening diameter conversion member, the present invention is suitable for inkjet heads.

[0013] 1 shows an exploded perspective view of a liquid ejection head 1 according to this embodiment. The liquid ejection head 1 has a flow path unit 3 on which an ejection element substrate 4 is provided. The detailed configuration of the ejection element substrate 4 will be described later. The flow path unit 3 is a unit formed of flow paths for supplying liquid to the ejection element substrate 4.

[0014] The liquid ejection head 1 has a circulation unit 2 for circulating the liquid inside the liquid ejection head 1. The circulation unit 2 preferably includes a circulation pump (shown) for circulating the liquid and a pressure adjustment means (shown) for adjusting the pressure inside the liquid ejection head 1. The liquid ejection head 1 of this embodiment has the circulation unit 2, but may be configured without the circulation unit 2. Having the circulation unit 2 is more preferable because it prevents the liquid from stagnating in the opening diameter conversion plate 201 (FIG. 2), which will be described later. The circulation pump is preferably a small diaphragm pump, but may also be another type of tube pump, etc.

[0015] The liquid ejection head 1 has an electric wiring member 6 for driving a circulation pump provided in the circulation unit 2. The electric wiring member 6 is electrically connected to the main body of the liquid ejection device (shown in the accompanying drawings) and supplies power to the circulation pump. Furthermore, the electric wiring member 6 also serves to supply power to the ejection elements 101 (FIG. 2) provided on the ejection element substrate 4 via a flexible wiring board 7.

[0016] The liquid ejection head 1 has the above-described configuration covered by a frame 9 and a housing 10. The liquid ejection head 1 of this embodiment is mounted on a carriage of a liquid ejection device (not shown) and is a so-called serial head that moves relative to a recording medium onto which liquid is ejected from the liquid ejection head. Note that the liquid ejection head 1 may also be a so-called full-line head in which multiple ejection element substrates 4 are arranged in parallel with the recording medium.

[0017] Fig. 2 is a schematic cross-sectional view of the liquid ejection head 1, and Fig. 3 is an exploded cross-sectional view of the liquid ejection head. The ejection element substrate 4 is constructed by laminating an ejection port forming substrate 106, a pressure chamber forming substrate 107, and a flow path forming substrate 108.

[0018] The ejection orifice-forming substrate 106 has ejection orifices 102 formed therein for ejecting liquid. The material of the ejection orifice-forming substrate 106 is not particularly limited, but inorganic materials such as photosensitive resin compositions and SUS can be used. The flow path-forming substrate 108 has supply flow paths 104 (also referred to as supply openings) for supplying liquid to the ejection orifices. The flow path-forming substrate 108 also has ejection elements 101 formed therein for generating pressure for ejecting liquid from the ejection orifices 102. The ejection elements 101 may be of a thermal type that generates pressure for ejecting liquid using a thermoelectric conversion element, or a piezoelectric type that generates pressure for ejecting liquid using a piezoelectric element. Other liquid ejection methods are also possible. Power is supplied to the ejection elements 101 via wiring 109. The material of the flow path-forming substrate is not particularly limited, but it is preferably made of silicon. By forming the flow path-forming substrate 108 from silicon, the flow paths can be formed with high precision. The pressure chamber-forming substrate 107 has pressure chambers formed therein for applying pressure generated by the ejection elements 101 to the liquid. The materials for the pressure chamber forming substrate 107 and the ejection port forming substrate 106 are not particularly limited, but they are preferably made of a photosensitive resin composition.

[0019] As described above, the ejection element substrate 4 has a first surface 111 (the front surface of the ejection port forming substrate 106) and a second surface 112 (the rear surface of the flow path forming substrate 108) that is the rear surface of the first surface 111. The ejection ports 102 are formed on the first surface 111, and the supply flow paths 104 are formed on the second surface 112.

[0020] The liquid ejection head 1 of this embodiment is a circulation head in which the liquid circulates. In a circulation head, a recovery flow path (also called a recovery opening) is formed to recover the liquid that has been supplied from the supply port but not ejected from the ejection port, and the liquid continues to circulate, which has the advantage of making it easier to prevent the liquid from accumulating and solidifying in the flow path.

[0021] In the liquid ejection head 1 of this embodiment, the liquid that has flowed through the supply flow path 104 is supplied to the plurality of supply flow paths 103. Then, the liquid is supplied from the plurality of supply flow paths 103 to the plurality of ejection ports 102, respectively. Therefore, the supply flow path 104 is a so-called common supply flow path, and the supply flow path 103 is a so-called individual supply flow path. Hereinafter, the supply flow path 104 will be referred to as the common supply flow path 104, and the supply flow path 103 will be referred to as the individual supply flow path 103. The liquid ejection head 1 of this embodiment also has a recovery flow path 113 and a recovery flow path 114 for recovering liquid that has not been ejected from the ejection ports 102. The recovery flow path 113 is a so-called individual recovery flow path 113 for recovering liquid from each of the plurality of ejection ports, and the recovery flow path 114 is a so-called common recovery flow path 114 for recovering liquid from the plurality of individual recovery flow paths 113. In this way, by having supply flow paths and recovery flow paths, the liquid ejection head 1 of this embodiment can prevent liquid from accumulating and solidifying in the flow paths.

[0022] The individual supply channels 103 and the common supply channel 104 can be formed by the Bosch process, which is a type of reactive ion etching, or anisotropic etching using TMAH or KOH. The Bosch process is a method of forming vertical etching grooves in the substrate by alternately protecting and etching the wall surface. Alternatively, a method of forming blind holes and thinning the substrate by back grinding or CMP can be used to penetrate the grooves.

[0023] The liquid supplied from the liquid storage section (shown in the accompanying drawings) to the ejection element substrate 4 passes through a large-diameter flow path, whereas the ejection element substrate 4 has a fine flow path structure, so it is necessary to collect the liquid from the large-diameter flow path to the fine ejection element substrate 4.

[0024] For this reason, the liquid ejection head 1 of this embodiment has an aperture diameter conversion plate 201. The ejection element substrate 4 and the aperture diameter conversion plate 201 are stacked in a first direction (stacking direction). The aperture diameter conversion plate 201 has a third surface 213 and a fourth surface 214, which is the back surface of the third surface 213. A first opening 211 connected to the supply flow path 104 and having a first aperture width W1 is formed on the third surface 213, and a second opening 212 communicating with the first opening 211 and having a second aperture width W2 is formed on the fourth surface 214. In a second direction perpendicular to the stacking direction of the ejection element substrate 4 and the aperture diameter conversion plate 201, the second aperture width W2 is larger than the first aperture width W1. For this reason, the aperture diameter conversion plate 201 functions to collect liquid from large-diameter flow paths to the fine ejection element substrate 4.

[0025] The aperture diameter conversion plate 201 is directly connected to the ejection element substrate 4, in other words, the aperture diameter conversion plate 201 is located near the ejection element substrate, so that stagnation of liquid in the flow paths inside the aperture diameter conversion plate 201 becomes an issue.

[0026] Therefore, in the opening diameter conversion plate 201 of this embodiment, the first opening 211 and the second opening 212 are connected by a supply connection channel 202, and the wall surface of the supply connection channel 202 includes an inclined portion 203 that is inclined with respect to the first direction (stacking direction). This reduces the number of bent portions of the channel inside the opening diameter conversion plate 201, making it possible to suppress concentration and solidification of liquid in the channel formed inside the opening diameter conversion plate 201. Furthermore, the flow direction of the liquid flowing through the supply connection channel 202 is also inclined with respect to the first direction (stacking direction). This makes it easier for the liquid to flow to the corners of the channel formed inside the opening diameter conversion plate 201, reducing the risk of the liquid stagnation.

[0027] When viewed from the first direction (stacking direction), it is preferable that the first opening 211 and the second opening 212 do not overlap. With this configuration, the liquid that has flowed from the liquid storage section through the large-diameter flow path can be easily collected on the fine ejection element substrate 4.

[0028] The angle θ of inclination of inclined portion 203 with respect to the first direction is preferably 55° or more and 80° or less. With an inclination angle in this range, the liquid flowing through supply connection channel 202 can easily flow to the corners of the channel. Of the wall surfaces of supply connection channel 202, the wall surface facing inclined portion 203 may be a vertical surface.

[0029] Note that various films may be formed between the ejection element substrate 4 and the aperture diameter conversion plate 201 .

[0030] Since the liquid ejection head 1 of this embodiment is a liquid ejection head in which liquid circulates, the opening diameter conversion plate 201 is also formed with a structure for recovering liquid. The opening diameter conversion plate 201 is formed with a third opening 223 that connects to the common recovery channel 114 and is formed on the third surface 213, and a fourth recovery port 224 that communicates with the third opening 223 and is formed on the fourth surface 214. The third opening 223 and the fourth opening 224 are connected by a recovery connection channel 222. The opening widths of the third opening 223 and the fourth opening 224 are not particularly limited. Furthermore, the wall surface of the recovery connection channel 222 does not need to have an inclined portion.

[0031] A support substrate 301 for supporting the ejection element substrate 4 and the aperture diameter conversion plate 201 is bonded to the fourth surface 214 side of the aperture diameter conversion plate 201. The support substrate 301 is formed with supply through-holes 302 that connect to the second openings 212 of the aperture diameter conversion plate 201 and supply liquid, and recovery through-holes 303 that connect to the fourth openings 224 and recover liquid.

[0032] The liquid ejection head 1 has the above-mentioned flow path configuration, and the liquid circulates in the order of the supply through-hole, supply connection flow path, supply opening, recovery opening, recovery connection flow path, and recovery through-hole. The ejection element substrate 4 and the aperture diameter conversion plate 201 are bonded together with an adhesive layer 401, and the aperture diameter conversion plate 201 and the support substrate 301 are bonded together with an adhesive layer 402. Note that an adhesive film or the like may be formed between the ejection element substrate 4 and the aperture diameter conversion plate 201, and between the aperture diameter conversion plate 201 and the support substrate 301.

[0033] In a second direction orthogonal to the first direction (lamination direction), when the pitch between adjacent common supply channels 104 and common recovery channels 114 is P1, it is preferable that P1 is 0.6 mm or less. The smaller P1 is, the smaller the size of the discharge element substrate 4 can be, and the cost can be reduced.

[0034] In a second direction orthogonal to the first direction (lamination direction), when the distance between the center of the first opening and the center of the third opening is P2, if P1 > P2, corners are formed in the channels on the side of the opening diameter conversion plate 201 of the common supply channel or the common recovery channel, and liquid tends to accumulate. Therefore, it is preferable that P1 ≤ P2.

[0035] In a second direction orthogonal to the first direction (lamination direction), when the distance between the center of the second opening 212 and the center of the fourth opening 224 is P3, it is preferable that P3 is 3.0 mm or more.

[0036] In a second direction orthogonal to the first direction (lamination direction), when the distance between the center of the supply through-hole and the center of the recovery through-hole is P4, if P3 > P4, corners are formed near the fourth opening 224 of the opening diameter conversion plate 201, and liquid tends to accumulate. Therefore, it is preferable that P3 ≤ P4.

[0037] From the viewpoint of aggregating liquid on the discharge element substrate 4 by the opening diameter conversion plate 201, it is preferable that P2 < P3.

[0038] The opening diameter conversion plate 201 is preferably formed of silicon. As the crystal plane of the silicon substrate, substrates with (100) or (110) planes can be selected. Particularly when wet etching is performed with an alkaline aqueous solution using a substrate with a crystal plane of (110), the wall surfaces of the supply connection channel 202 and the recovery connection channel 222 can be easily formed vertically. Further, when the inclined portion 203 is laser-irradiated by a laser processing apparatus such as a YAG laser, and the processing diameter of the laser processing portion is R and the processing pitch is T, the supply connection channel 202 having the inclined portion 203 can be continuously formed by processing so that T < R / 2. Also, as shown in the cross-sectional view of the supply connection channel in FIG. 4, when the processing diameter is R and the processing pitch is T, the supply connection channel 202 can be discontinuously formed by processing so that T < 2R. When the supply connection channel 202 is formed discontinuously, the rigidity of the opening diameter conversion plate 201 can be increased compared to the case where it is formed continuously. Further, by performing etching with an alkaline aqueous solution such as TMAH (tetramethylammonium hydroxide aqueous solution) or KOH (potassium hydroxide aqueous solution) after laser processing, it is also possible to remove silicon debris generated by laser processing and smooth the processed surface.

[0039] (Example) Next, a manufacturing method of the aperture diameter conversion plate 201 of this embodiment will be described with reference to FIG. 5. First, a silicon substrate 201 having a thickness of 0.725 mm was prepared as shown in FIG. 5(a). Next, as shown in FIG. 5(b), a photoresist 207 was formed on the fourth surface 214 of the silicon substrate, and the photoresist 207 was patterned in the region of the fourth surface 214 where the second aperture 212 and the fourth aperture 224 were to be formed. Next, as shown in FIG. 5(c), blind holes including the second aperture 212 and the fourth aperture 224 were formed to a depth of 400 μm by dry etching using the Bosch process. Similarly, as shown in FIG. 5(d), blind holes including the first aperture 211 were formed to a depth of 400 μm on the third surface 213. At this time, by forming a through hole including the third aperture 223, the third aperture 223 and the fourth aperture 224 were connected by the recovery connection channel 222. In the step of FIG. 5(d), the silicon substrate 201 is flipped over from the state of FIG. 5(c). Next, as shown in FIG. 5(e), the photoresist 207 formed on the silicon substrate was removed. Next, as shown in FIG. 5(f), laser processing was performed so that the blind holes including the first openings 211 and the blind holes including the second openings 212 communicated with each other. At this time, the laser processing was performed so that the inclination angle θ with respect to the first direction (stacking direction) was 75°. In addition, P1 and P2 were 0.6 mm, P3 was 3.0 mm, P4 was 3.3 mm, W1 was 0.25 mm, and W2 was 1.8 mm.

[0040] The aperture diameter conversion plate 201 manufactured by the above-described process was laminated with the ejection element substrate 4 and the support substrate 301 to manufacture a liquid ejection head as shown in Fig. 1. The liquid ejection head 1 manufactured in this manner has an inclined portion 203 inside the aperture diameter conversion plate 201, which prevents the liquid from accumulating, concentrating, and solidifying inside the aperture diameter conversion plate 201.

[0041] To summarize the present invention as described above, the present invention includes the following configurations and methods.

[0042] (Configuration 1) an ejection element substrate having a first surface and a second surface that is the reverse side of the first surface, in which ejection ports for ejecting liquid are formed in the first surface and supply openings for supplying liquid to the ejection ports are formed in the second surface; an opening diameter conversion plate having a third surface and a fourth surface that is the reverse side of the third surface, wherein a first opening connected to the supply opening and having a first opening width is formed in the third surface, and a second opening communicating with the first opening and having a second opening width is formed in the fourth surface; Equipped with the ejection element substrate and the aperture diameter conversion plate are stacked in a first direction, a liquid ejection head in which the second opening width is larger than the first opening width in a second direction perpendicular to the first direction, a supply connection flow path that connects the first opening and the second opening is formed in the opening diameter conversion plate; The liquid ejection head is characterized in that a wall surface of the supply connection flow path includes an inclined portion inclined with respect to the first direction.

[0043] (Configuration 2) 2. The liquid ejection head according to configuration 1, wherein the flow direction of the liquid flowing through the supply connection channel is inclined with respect to the first direction.

[0044] (Configuration 3) 3. The liquid ejection head according to configuration 1 or 2, wherein the angle of inclination of the inclined portion with respect to the first direction is equal to or greater than 55° and equal to or less than 80°.

[0045] (Configuration 4) 4. The liquid ejection head according to any one of configurations 1 to 3, wherein the first opening and the second opening do not overlap when viewed from the first direction.

[0046] (Configuration 5) 5. The liquid ejection head according to any one of configurations 1 to 4, wherein the aperture diameter conversion plate is made of silicon.

[0047] (Configuration 6) the ejection element substrate has a recovery opening for recovering liquid that has not been ejected from the ejection orifices, A liquid ejection head described in any one of configurations 1 to 5, wherein the opening diameter conversion plate comprises a third opening connected to the recovery opening and formed on the third surface, a fourth opening communicating with the third opening and formed on the fourth surface, and a recovery connection flow path connecting the third opening and the fourth opening.

[0048] (Configuration 7) 7. The liquid ejection head according to configuration 6, wherein the liquid circulates through the supply connection channel, the supply opening, the recovery opening, and the recovery connection channel in this order.

[0049] (Configuration 8) The liquid ejection head according to configuration 6 or 7, wherein when the distance between the center of the supply opening and the center of the recovery opening in the second direction is defined as P1, P1 is 0.6 mm or less.

[0050] (Configuration 9) The liquid ejection head according to any one of configurations 6 to 8, wherein when the distance between the center of the first opening and the center of the third opening in the second direction is P2, P1≦P2.

[0051] (Configuration 10) A liquid ejection head according to any one of configurations 6 to 9, wherein when the distance between the center of the second opening and the center of the fourth opening in the second direction is P3, P3 is 3.0 mm or more.

[0052] (Configuration 11) a supply through hole for supplying liquid to the second opening and a recovery through hole for recovering liquid from the fourth opening are formed, and the ejection element substrate and the opening diameter conversion plate are supported by a support substrate; the support substrate is joined to the fourth surface of the opening diameter conversion plate so that the second opening and the supply through hole are connected and the fourth opening and the recovery through hole are connected; In the second direction, when the distance between the center of the supply through-hole and the center of the recovery through-hole is P4, the liquid discharge head according to Configuration 10, wherein P3 ≤ P4.

[0053] (Configuration 12) The liquid discharge head according to Configuration 10, wherein P2 < P3.

[0054] (Configuration 13) The liquid discharge head according to any one of Configurations 1 to 12, further comprising a circulation pump for circulating the liquid.

[0055] (Method 1) A discharge element substrate having a discharge port for discharging a liquid and a supply opening for supplying the liquid to the discharge port, An aperture diameter conversion plate having a first aperture connected to the supply opening and having a first aperture width and a second aperture connected to the first aperture and having a second aperture width, wherein the discharge element substrate and the aperture diameter conversion plate are laminated in a first direction, A method for manufacturing a liquid discharge head, wherein in a second direction orthogonal to the first direction, the second aperture width is larger than the first aperture width, An etching step of forming the first aperture and the second aperture by etching, A laser processing step of communicating between the first aperture and the second aperture by laser processing to form a supply connection flow path connecting the first aperture and the second aperture, Including, The method for manufacturing a liquid discharge head, wherein the supply connection flow path includes an inclined portion inclined with respect to the first direction.

[0056] (Method 2) The method for manufacturing a liquid discharge head according to Method 1, wherein the aperture diameter conversion plate is formed of silicon.

[0057] (Method 3) 3. The method for manufacturing a liquid ejection head according to Method 1 or 2, wherein the etching step is carried out by reactive ion etching or wet etching using an alkaline aqueous solution.

[0058] (Method 4) The method for manufacturing a liquid ejection head according to Method 3, wherein the alkaline aqueous solution is a tetramethylammonium hydroxide aqueous solution or a potassium hydroxide aqueous solution. [Explanation of symbols]

[0059] 1 Liquid ejection head 2 Ejection element board 102 Discharge port 103 Individual supply channel 104 common supply channel (supply opening) 106 Discharge port formation substrate 107 Pressure chamber forming substrate 108 Flow path forming substrate 111 First Side 112 Second Side 201 Opening diameter conversion plate 202 Supply connection channel 203 Slope 211 First Opening 212 Second Opening 213 Third Side 214 The Fourth Side

Claims

1. an ejection element substrate having a first surface and a second surface that is the reverse side of the first surface, in which ejection ports for ejecting liquid are formed in the first surface and supply openings for supplying liquid to the ejection ports are formed in the second surface; an opening diameter conversion plate having a third surface and a fourth surface that is the reverse side of the third surface, wherein a first opening connected to the supply opening and having a first opening width is formed in the third surface, and a second opening communicating with the first opening and having a second opening width is formed in the fourth surface; Equipped with the ejection element substrate and the aperture diameter conversion plate are stacked in a first direction, a liquid ejection head in which the second opening width is larger than the first opening width in a second direction perpendicular to the first direction, a supply connection flow path that connects the first opening and the second opening is formed in the opening diameter conversion plate; A liquid ejection head, wherein a wall surface of the supply connection flow path includes an inclined portion inclined with respect to the first direction.

2. 2. The liquid ejection head according to claim 1, wherein the flow direction of the liquid flowing through the supply connection channel is inclined with respect to the first direction.

3. The liquid ejection head according to claim 1 , wherein the angle of inclination of the inclined portion with respect to the first direction is equal to or greater than 55° and equal to or less than 80°.

4. The liquid ejection head according to claim 1 , wherein the first opening and the second opening do not overlap when viewed from the first direction.

5. The liquid ejection head according to claim 1 , wherein the aperture diameter conversion plate is made of silicon.

6. the ejection element substrate has a recovery opening for recovering liquid that has not been ejected from the ejection orifices, 2. The liquid ejection head according to claim 1, wherein the opening diameter conversion plate comprises a third opening connected to the recovery opening and formed on the third surface, a fourth opening communicating with the third opening and formed on the fourth surface, and a recovery connection flow path connecting the third opening and the fourth opening.

7. The liquid ejection head according to claim 6 , wherein the liquid circulates in the order of the supply connection channel, the supply opening, the recovery opening, and the recovery connection channel.

8. 8. The liquid ejection head according to claim 7, wherein when the distance between the center of the supply opening and the center of the recovery opening in the second direction is defined as P1, P1 is 0.6 mm or less.

9. 9. The liquid ejection head according to claim 8, wherein when a distance between a center of the first opening and a center of the third opening in the second direction is P2, P1≦P2.

10. 10. The liquid ejection head according to claim 9, wherein when a distance P3 is defined as a distance between a center of the second opening and a center of the fourth opening in the second direction, P3 is 3.0 mm or more.

11. a supply through-hole for supplying liquid to the second opening and a recovery through-hole for recovering liquid from the fourth opening are formed, and the ejection element substrate and the opening diameter conversion plate are supported by a support substrate; the support substrate is joined to the fourth surface of the opening diameter conversion plate so that the second opening and the supply through hole are connected and the fourth opening and the recovery through hole are connected; 11. The liquid ejection head according to claim 10, wherein when a distance P4 is defined as a distance between a center of the supply through-hole and a center of the recovery through-hole in the second direction, P3≦P4.

12. The liquid ejection head according to claim 11, wherein P2<P3.

13. The liquid ejection head according to claim 7 , further comprising a circulation pump for circulating the liquid.

14. an ejection element substrate in which ejection ports for ejecting liquid and supply openings for supplying liquid to the ejection ports are formed; an aperture diameter conversion plate in which a first aperture connected to the supply aperture and having a first aperture width, and a second aperture connected to the first aperture and having a second aperture width are formed, the ejection element substrate and the aperture diameter conversion plate are stacked in a first direction, A method for manufacturing a liquid ejection head, wherein the second opening width is larger than the first opening width in a second direction perpendicular to the first direction, an etching step of forming the first opening and the second opening by etching; a laser processing step of communicating the first opening and the second opening by laser processing to form a supply connection flow path connecting the first opening and the second opening; Including, The method for manufacturing a liquid ejection head, wherein the supply connection flow path includes an inclined portion inclined with respect to the first direction.

15. The method for manufacturing a liquid ejection head according to claim 14, wherein the opening diameter conversion plate is made of silicon.

16. The method for manufacturing a liquid ejection head according to claim 14, wherein the etching step is carried out by reactive ion etching or wet etching using an alkaline aqueous solution.

17. The method for manufacturing a liquid ejection head according to claim 16, wherein the alkaline aqueous solution is a tetramethylammonium hydroxide aqueous solution or a potassium hydroxide aqueous solution.

Images