JP2024001905A - Liquid ejection head and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejection head that prevents ejection failure by reducing flow resistance of a liquid and to provide a method for manufacturing the same.

SOLUTION: A liquid ejection head includes: an ejection port 2 that ejects a liquid; an ejection-port formation substrate 1 in which the ejection port is formed; a pressure generating element that generates pressure for ejecting the liquid; a pressure chamber 8 on which the pressure generated by driving of the pressure generating element acts; a pressure-chamber formation substrate 11 in which a pressure chamber is formed; wherein the ejection-port formation substrate 1 and the pressure-chamber formation substrate 11 are bonded to each other; and wherein a vertical groove is formed in a pressure-chamber-side internal wall of the ejection port.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a liquid ejection head and a method for manufacturing the same.

In recent years, in the field of inkjet printers, there has been a demand for high-quality and high-speed printed matter output. An inkjet printer is provided with a liquid ejection head that ejects liquid. Furthermore, the liquid ejection head includes an ejection port for ejecting droplets, a pressure generating element such as a heater or a piezoelectric element that generates pressure for ejecting the liquid, and a pressure chamber on which the pressure acts.

Patent Document 1 discloses a discharge port forming substrate on which a discharge port is formed, a pressure chamber forming substrate forming a pressure chamber, and a liquid flow path forming substrate provided with a pressure generating element and serving as a flow path communicating with the pressure chamber. A bonded liquid ejection head is described. In the liquid ejection head, the pressure generated by the pressure generating element acts on the liquid flowing through the flow path of the liquid flow path forming substrate in the pressure chamber, so that the liquid is ejected from the ejection port. Further, by supplying the liquid that has flowed through the flow path of the liquid flow path forming substrate to the ejection port by the amount of the ejected liquid, the meniscus is kept constant and the liquid can be continuously ejected at high speed.

Japanese Patent Application Publication No. 2012-250517

However, in the liquid ejection head described in Patent Document 1, when liquid is continuously ejected at high speed, there is a risk that ejection failure may occur due to large flow resistance of the ejection port, liquid flow path, etc. For example, when a liquid is ejected from an ejection port, there are liquids that are ejected and liquids that are attracted by tension to the ejected liquid but are not ejected. Such undischarged liquid forms a gap in the meniscus due to the return force when returning to the liquid surface. At this time, if the meniscus reaches the opening end of the discharge port forming substrate, the opening end of the discharge port forming substrate becomes a resistance. As a result, it becomes difficult for the liquid to be introduced into the ejection port, and, for example, the liquid may not be refilled in time for the ejection operation at a high frequency, which may result in ejection failure.

In addition, if the pressure chamber forming substrate and the liquid flow path forming substrate are bonded with adhesive, the liquid flow path may be blocked by excess adhesive, increasing flow resistance and making it difficult for the liquid to flow. . In such a case, it becomes difficult to supply the liquid to the ejection port, and there is a possibility that the liquid cannot be refilled in time for the ejection operation at a high frequency, resulting in ejection failure.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a liquid ejection head that can suppress ejection failure by reducing the flow resistance of liquid, and a method for manufacturing the same.

In order to solve the above problems, the present invention provides an ejection port for ejecting a liquid, an ejection port forming substrate on which the ejection port is formed, a pressure generating element that generates pressure for ejecting the liquid, and a pressure generating element that generates a pressure for ejecting the liquid. A liquid ejection head having a pressure chamber on which pressure generated by driving an element acts, and a pressure chamber forming substrate on which the pressure chamber is formed, the ejection port forming substrate and the pressure chamber forming substrate being joined. A vertical groove is formed in the inner wall of the discharge port on the pressure chamber side.

According to the present invention, it is possible to provide a liquid ejection head that suppresses ejection failure by reducing the flow resistance of liquid, and a method for manufacturing the same.

FIG. 3 is a cross-sectional view of a liquid ejection head. FIG. 3 is an enlarged view of the vicinity of the ejection port of the liquid ejection head. FIG. 2 is a cross-sectional view of a liquid ejection head including a two-layered ejection port forming substrate. FIG. 3 is an enlarged view of the vicinity of a joint of a two-layer discharge port forming substrate. FIG. 3 is an enlarged view of the vicinity of the ejection port of the liquid ejection head. FIG. 3 is an enlarged view of the joint between the pressure chamber forming substrate and the liquid flow path forming substrate. FIG. 3 is a schematic diagram showing a method of manufacturing a liquid ejection head.

Hereinafter, examples of each embodiment of the present invention will be described using the drawings. Note that the following embodiments do not limit the matters of the present invention, and not all combinations of features described in the present embodiments are essential to the solution of the present invention. Note that the same reference numbers are given to the same components.

(First embodiment)
FIG. 1 is a cross-sectional view of the liquid ejection head 100. In the liquid ejection head 100 of the present invention, an ejection port forming substrate 1, a pressure chamber forming substrate 4, and a liquid flow path forming substrate 7 are stacked in this order. These substrates may be formed from a plurality of substrates, or a plurality of other substrates may be stacked.

A discharge port 2 for discharging a liquid is formed in the discharge port forming substrate 1 . The discharge port forming substrate 1 is bonded to the pressure chamber forming substrate 4 with an adhesive 3. The method of bonding the discharge port forming substrate 1 and the pressure chamber forming substrate 4 is not limited to the adhesive 3, but any method is sufficient as long as the two substrates can be bonded.

The pressure chamber forming substrate 4 is joined to the diaphragm 5, and forms a pressure chamber to which pressure generated by driving a pressure generating element, which will be described later, acts. The pressure chamber forming substrate 4 and the diaphragm 5 are collectively referred to as a pressure chamber forming substrate 11. The pressure chamber forming substrate 11 is bonded to the liquid flow path forming substrate 7 on which the liquid flow path 10 is formed using an adhesive 6. The liquid supplied in the direction of the arrow in the figure flows through the liquid flow path 10 and is supplied to the pressure chamber 8.

Here, the material of the adhesive 3 and the adhesive 6 is any one resin selected from the group consisting of acrylic resin, epoxy resin, silicone resin, benzocyclobutene resin, polyamide resin, polyimide resin, and urethane resin. It is preferable to include. It is more preferable that the adhesive contains benzocyclobutene resin since high bonding strength can be obtained.

A piezoelectric element 9 as a pressure generating element and a common electrode (not shown) for piezoelectric driving electrically connected to the piezoelectric element 9 are formed on the diaphragm 5 . Further, the common electrode of each piezoelectric element is connected to a drive circuit via a wiring member (for example, a flexible cable, etc.) not shown. By transmitting the driving electric signal to the piezoelectric element 9, the piezoelectric element 9 causes a volume change, and transmits the volume change to the pressure chamber 8 via the diaphragm 5. As a result, the pressure within the pressure chamber 8 changes, and the liquid filled within the pressure chamber 8 is discharged from the discharge port 2.

Here, the piezoelectric element 9 has been described as an example of the pressure generating element, but the pressure generating element may be a heater that changes the pressure within the pressure chamber using heat. When the pressure generating element is a heater, the liquid ejection head 100 does not need to have the diaphragm 5. In that case, the pressure chamber forming substrate 4 may be directly joined to the liquid flow path forming substrate 7.

In the case of a conventional liquid ejection head, as described above, when ejecting liquid from an ejection port, some liquid returns to the ejection port without being ejected, although it is attracted by the tension of the liquid actually ejected. When such undischarged liquid is released from the tension of the discharged liquid and returns into the discharge port, the meniscus position may retreat into the pressure chamber due to the returning force. Due to the retreat of the meniscus position, when the meniscus reaches the opening end of the entrance of the discharge port, the opening end of the entrance of the discharge port becomes a resistance. As a result, it becomes difficult for the liquid to be quickly introduced into the ejection port, and the liquid cannot be refilled in time for the ejection operation at a high frequency, which may result in ejection failure.

FIG. 2 is an enlarged view of the vicinity of the ejection ports of the liquid ejection head of this embodiment. 2(a) is a top view of the liquid ejection head 100 viewed from the ejection port forming substrate 1 side, FIG. 2(b) is a perspective view of the ejection port 2, and FIG. 2(c) is an enlarged view of the vicinity of the ejection port. 2(d) is a bottom view of the discharge port viewed from the pressure chamber forming substrate 4 side. In this embodiment, as shown in FIG. 2(c), a vertical groove 21 is formed in the inner wall of the discharge port on the pressure chamber side.

Even if a gap is formed in the meniscus due to liquid ejection and the meniscus extends to the open end of the ejection port forming substrate 1, the vertical groove 21 is formed on the inner wall of the ejection port 2 on the pressure chamber side. This makes it easier for liquid to be introduced into the discharge port due to capillary action. That is, by forming the vertical grooves 21, flow resistance can be reduced. As a result, even if the ejection operation is performed at a high frequency, the liquid refill can catch up with the ejection operation, and ejection failures can be suppressed.

The vertical grooves 21 refer to groove-shaped recesses formed substantially parallel to the communication direction of the discharge ports 2, as shown in FIGS. 2(b) and 2(c). Note that, as shown in FIG. 2(a), a vertical groove is formed on the inner wall of the discharge port 2 on the pressure chamber side, and no vertical groove is formed on the inner wall of the discharge port 2 on the opposite side from the pressure chamber. It is preferable. As a result, on the wall surface of the discharge port 2 on the pressure chamber side, the surface tension with the opening end of the discharge port forming substrate is suppressed, making it easier for liquid to be introduced into the discharge port, while changing the shape of the meniscus to a round shape when discharging the liquid. Therefore, the accuracy of the ejected liquid is not impaired. That is, ejection failure can be suppressed without impairing the image quality of printed matter.

From the viewpoint of facilitating the introduction of liquid by capillary action, it is preferable that a plurality of vertical grooves in the present invention are formed along the circumferential direction of the discharge port. Further, the diameter d of the vertical groove is preferably 1 μm or less so that the liquid can be efficiently introduced by capillary action. Here, the diameter d of the vertical groove indicates the width of the groove-like recess.

According to the above configuration, the liquid is easily introduced into the ejection port due to capillary action, so the flow resistance of the liquid is reduced, and ejection failure can be suppressed.

(Second embodiment)
The configuration of a liquid ejection head in a second embodiment of the present invention will be described using FIG. 3. In the following description, only the parts that are different from the first embodiment will be mainly described, and the description of the same parts as the first embodiment will be omitted.

In this embodiment, the discharge port forming substrate 1 is configured by bonding a first substrate 31 disposed on the pressure chamber side and a second substrate 32 disposed on the opposite side to the pressure chamber with an adhesive 36. There is. The first substrate 31 has a first through hole 33 , and the second substrate 32 has a second through hole 34 . A discharge port 35 is formed by the first through hole 33 and the second through hole 34 communicating with each other. It is preferable that the diameters of the first through hole 33 and the second through hole 34 are approximately the same.

FIG. 4 is an enlarged view of the vicinity of the joint between the first substrate 31 and the second substrate 32. As described above, the first substrate 31 and the second substrate 32 are bonded with the adhesive 36. The liquid flowing from the pressure chamber 8 passes through the first through hole 33 and the second through hole 34 in this order, and is discharged from the liquid discharge head.

In the second embodiment, a vertical groove 37 is formed in the inner wall of the first through hole 33 on the pressure chamber side, and a vertical groove 38 is formed in the inner wall of the first through hole 33 on the second substrate side. By forming the vertical groove 37 on the inner wall of the first through hole 33 on the pressure chamber side, liquid can be easily introduced into the first through hole 33, as in the first embodiment. Furthermore, since the vertical groove 38 is formed in the inner wall of the first through hole 33 on the second substrate side, the excess adhesive that joins the first substrate 31 and the second substrate 32 can pass through the discharge port 35. The fear of blockage can be suppressed. That is, the vertical groove 38 formed on the second substrate side of the first through hole 33 serves as an escape groove for excess adhesive. In this way, by suppressing blockage due to excess adhesive, flow resistance can be reduced and discharge failures can be suppressed.

Note that the vertical groove 37 formed in the inner wall of the first through hole 33 on the pressure chamber side and the vertical groove 38 formed in the inner wall of the second substrate side may be the same vertical groove. That is, the vertical grooves 37 and 38 may be connected. Even in this case, the vertical grooves can serve to lower the flow resistance and serve as escape grooves for excess adhesive.

Of the adhesive bonding the first substrate 31 and the second substrate 32, unevenness tends to occur in the communicating portion of the discharge port 35. If there are such irregularities in the communication portion of the discharge port 35, the flow resistance of the liquid increases, and the flow of the liquid is obstructed. As a result, ejection failure may occur due to variations in ejection speed and ejection volume. Therefore, it is preferable that a vertical groove 39 be formed in the inner wall of the second through hole 34 on the first substrate 31 side. Thereby, the liquid can be easily introduced into the second through hole 34 by collapsing the meniscus shape of the liquid at the opening on the first substrate side by the capillary phenomenon of the vertical grooves. As a result, the liquid can be refilled in time even when ejecting at a high frequency, and ejection failures can be suppressed.

Similarly to the vertical grooves in the first embodiment, a plurality of vertical grooves in this embodiment are preferably formed along the circumferential direction of the discharge port, and the diameter of the vertical grooves is preferably 1 μm or less.

According to the above configuration, even if the discharge port forming substrate is formed by bonding multiple substrates with adhesive, the flow resistance of the liquid at the bonding surface of the substrates is reduced and discharge failures are suppressed. You can.

(Third embodiment)
The configuration of a liquid ejection head in a third embodiment of the present invention will be described. FIG. 5 is an enlarged view of the vicinity of the ejection ports of the liquid ejection head in the third embodiment. In the third embodiment, not only a vertical groove 21 is formed on the inner wall of the discharge port 2 on the pressure chamber side, but also an uneven portion 51 is formed on the inner wall on the opposite side from the pressure chamber.

When droplets are continuously ejected to improve printing speed, the meniscus at the tip of the nozzle hole is attracted to the ejected droplets and vibrates, causing the droplets to lose their shape and fail to land in the desired shape or location. There is a fear. Therefore, it is important to stabilize the meniscus shape at the tip of the ejection port after ejecting the liquid.

When a scallop (uneven) structure is formed on the inner wall of the discharge port 2 on the side opposite to the pressure chamber, the opening end of the discharge port on the side from which liquid is discharged becomes rounded, and the shape of the discharged droplets is stabilized. It tends to have a round shape. As a result, the landing accuracy of the liquid is improved, and deterioration in the image quality of printed matter can be suppressed.

According to the above configuration, the scallop structure 51 is formed on the inner wall on the side opposite to the pressure chamber of the ejection port, while suppressing ejection failure during high-frequency driving, thereby suppressing deterioration in the image quality of printed matter. It is possible.

(Fourth embodiment)
The configuration of a liquid ejection head in a fourth embodiment of the present invention will be described. In this embodiment, the ejection port forming substrate 1 has the same configuration as that described in FIG. 1, so the description thereof will be omitted. FIG. 6 is an enlarged view of the vicinity of the bonding surface between the pressure chamber forming substrate 11 and the liquid flow path forming substrate 7. As shown in FIG. As described above, the pressure chamber forming substrate 11 and the liquid flow path forming substrate 7 are bonded with the adhesive 6. By joining the pressure chamber forming substrate 11 and the liquid flow path forming substrate 7, a liquid flow path 10 through which liquid is supplied to the pressure chamber 8 is formed.

When the pressure chamber forming substrate 11 and the liquid flow path forming substrate 7 are bonded with the adhesive 6, when the arrangement of the liquid flow paths 10 is made denser, excess adhesive may protrude from the bonding surface. Cheap. As a result, the liquid flow path is blocked, flow resistance increases, and discharge failure may occur.

In the fourth embodiment, a vertical groove 41 is formed in the inner wall of the liquid flow path 10 on the pressure chamber forming substrate side. The excess adhesive fills the vertical grooves 41 by capillary action, forming an adhesive film 43 that extends in the circumferential direction on the inner wall of the liquid flow path 10. As a result, the risk of excess adhesive clogging the liquid flow path 10 is suppressed, and liquid is stably supplied to the pressure chamber 8 and the discharge port 2, so that discharge failures can be suppressed.

According to the above configuration, even when the pressure chamber forming substrate 11 and the liquid flow path forming substrate 7 are bonded with the adhesive 6, the flow resistance of the liquid due to the excess adhesive is reduced and discharge failures are suppressed. You can.

Note that the present invention is not limited to the above embodiments. Various changes and modifications can be made without departing from the spirit and scope of the invention. In addition, a configuration in which the configurations of each of the above-described embodiments are appropriately combined is also applicable. Examples according to the present invention will be shown below based on the above-described embodiments.

In this embodiment, a method of manufacturing a discharge port forming substrate 1 and a pressure chamber forming substrate 4, which are the characteristic parts of the present invention, will be explained. FIG. 7 is a schematic diagram showing a method of manufacturing the liquid ejection head in the above embodiment. Although a silicon substrate is used as the members of the discharge port forming substrate 1 and the pressure chamber forming substrate 4, the conductivity of the silicon substrate is not limited. That is, the conductivity of the silicon substrate may be any of P type, N type, and I type. Further, the thickness of the silicon substrate is, for example, about 725 μm, but is not limited to this.

First, as shown in FIG. 7(a), a silicon substrate 70 having a thickness of 725 μm, which will become the ejection port forming substrate 1, was prepared. The silicon substrate 70 has a first surface 71 that is the direction in which liquid is ejected from the ejection port 2, and a second surface 72 that is the back surface of the first surface 71. As shown in FIG. 7B, a recess 73 having a depth of 250 μm, which is deeper than the target substrate thickness of 200 μm of the ejection port forming substrate 1, was formed from the first surface 71 side of the silicon substrate 70. The recesses 73 were formed by patterning using photolithography and dry etching. A resist was applied to the first surface 71 of the silicon substrate 70 to a thickness of 10 um by spin coating, and exposed and developed to form an etching mask. A plurality of etching mask patterns (not shown) each having a diameter of 20 μm were formed on the first surface 71 of the silicon substrate 70 .

Next, a recess 73 having a plurality of vertical grooves 21 formed at the bottom was formed by dry etching using the Bosch process. Here, the Bosch process is a dry etching technique that periodically performs three steps: isotropic etching of a substrate, formation of an etching protection film, and anisotropic etching of the substrate. Specifically, the substrate is isotropically etched by isotropic etching, and an etching protection film is formed on the bottom and sidewalls of the etched recesses. Then, by performing anisotropic etching in the depth direction of the recess, the protective film on the bottom of the recess is removed without removing the protective film formed on the side walls of the recess, and etching proceeds only in the depth direction. I can go. This makes it possible to perform vertical deep excavation of the substrate at high speed and with a high aspect ratio.

In order to form the vertical grooves 21 in the recesses 73 by the Bosch process, it is possible to weaken the anisotropic etching conditions in the three etching cycles described above. When the anisotropy of the anisotropic etching is reduced by weakening the conditions, not only the bottom surface but also a portion of the protective film formed on the sidewalls is removed in the anisotropic etching process. That is, a portion of the side wall of the recess is exposed. By performing isotropic etching with the protective film residue formed on the sidewalls of the recess, the areas with the protective film residue will not be etched, and the areas where the protective film has been removed and part of the sidewall is exposed will be etched. As this progresses, vertical grooves are formed.

Specifically, sulfur hexafluoride gas was used as the etching gas, and fluorocarbon gas was used to form the protective film. Dry etching was performed by setting the bias power for anisotropic etching to 50 W, compared to the bias power of 100 W for normal anisotropic etching, to form vertical grooves in the recesses. Thereafter, the resist serving as an etching mask was removed to form a silicon substrate 70 as shown in FIG. 7(b).

Next, as shown in FIG. 7(c), the silicon substrate 70 was thinned to a thickness of 200 μm from the second surface 72, and the ejection port forming substrate 1 was manufactured. The thinning method was a combination of grinding thinning by back grinding, which is a method for thinning a silicon substrate, and polishing by CMP. Due to the thinning, the concave portion 73 became a through hole, and the discharge port 2 was formed in the discharge port forming substrate 1. At this time, the vertical groove 21 formed in the recess 73 was exposed to the discharge port opening, and the vertical groove 21 was formed in the direction along the hole starting from the discharge port opening.

By performing the thinning process from the back side of the substrate on which the recesses with vertical grooves were formed, it was possible to not only control the desired thickness of the substrate, but also form vertical grooves on the opening surface of the thinned side. . Since it is near the opening that the liquid experiences flow path resistance due to the surface tension of the meniscus, it is preferable that vertical grooves be formed at the opening of the discharge port.

Next, as shown in FIG. 7(d), a silicon substrate 77 having a thickness of 400 μm and serving as the pressure chamber forming substrate 4 was prepared separately. The silicon substrate 77 has a first surface 76 to which the adhesive 3 is applied and a second surface 75 on the back side.

Next, as shown in FIG. 7E, a through hole 78 that will become a pressure chamber 8 is opened in the first surface 76 of the silicon substrate 77, thereby producing a pressure chamber forming substrate 4. To form the through holes, patterning was first performed using photolithography. Specifically, a resist was applied to the surface of the silicon substrate 77 to a thickness of 10 um by spin coating, and exposed and developed to form an etching mask (not shown). A plurality of etching mask patterns were formed on the silicon substrate 77, each having a long side of 100 μm and a horizontal side of 50 μm.

Next, dry etching was performed using the Bosch process to form through holes. Specifically, dry etching was performed for 45 minutes using sulfur hexafluoride gas and fluorocarbon gas to form through holes 78 in the silicon substrate 77 at a set target depth of 450 μm. After forming the through hole 78, the resist serving as an etching mask was removed.

Next, as shown in FIG. 7(f), the adhesive 3 was formed on the first surface 76 of the pressure chamber forming substrate 4. As a method for forming an adhesive layer on a silicon substrate, a transfer method can be adopted in which an adhesive is applied to an adhesive transfer base material and then transferred to the substrate. Benzocyclobutene resin was used as the adhesive.

Examples of the adhesive curing method include a heat curing method and an ultraviolet delayed curing method. Specifically, a base material for adhesive transfer was prepared, and a benzocyclobutene solution as an adhesive was spin-coated to a thickness of 3 μm. A PET film was used as the transfer base material. In addition, in order to volatilize the solvent after applying the solution, baking treatment was performed at 100° C. for 5 minutes. The adhesive formed on the transfer base material was transferred by bringing it into contact with the first surface 76 of the pressure chamber forming substrate 4 while applying heat.

Next, as shown in FIG. 7(g), the third surface 74 of the ejection port forming substrate 1 and the first surface 76 of the pressure chamber forming substrate 4 are bonded together so as to face each other, thereby forming a liquid ejecting head. A bonded substrate 79 was formed. The substrates were bonded together using a substrate bonding device after positioning was adjusted using alignment marks (not shown) formed on the two substrates, and the adhesive was then cured. Specifically, the discharge port forming substrate 1 and the pressure chamber forming substrate 4 were aligned using a bonding alignment device, and the bonding was performed by heating in a vacuum. Bonding was performed at a vacuum degree of 100 Pa or less and a temperature of 150°C. After the bonding was completed and cooled, it was taken out from the apparatus and heat treated at 250° C. for 1 hour in an oven under a nitrogen atmosphere to harden the adhesive. In this way, the bonded substrate 79 of the liquid ejection head was completed.

Although the method for manufacturing the ejection port forming substrate 1 has been described above in detail, the liquid flow path forming substrate 7 can also be manufactured by the same method as the ejection port forming substrate 1. Furthermore, the created liquid flow path forming substrate 7 and pressure chamber forming substrate 4 can be bonded by the same method as the method of bonding the discharge port forming substrate 1 and the pressure chamber forming substrate 4.

Although the method for manufacturing the liquid ejection head in the first embodiment has been described above as an example, liquid ejection heads in other embodiments can also be manufactured using a similar method. For example, when the discharge port forming substrate is formed from the first substrate 31 and the second substrate 32, the first recess and the second recess are formed in the first substrate and the second substrate, respectively. The first through hole 33 and the second through hole 34 can be formed by performing dry etching.

The liquid ejection head 100 can be manufactured by joining the created ejection port forming substrate, pressure chamber forming substrate, and liquid flow path forming substrate.

To summarize the present invention as described above, the present invention includes the following configurations.

(Configuration 1)
A discharge port for discharging a liquid, a discharge port forming substrate on which the discharge port is formed, a pressure generating element that generates pressure for discharging the liquid, and a pressure on which the pressure generated by driving the pressure generating element acts. A liquid ejection head having a chamber and a pressure chamber forming substrate on which the pressure chamber is formed, the ejection port forming substrate and the pressure chamber forming substrate being joined, and the pressure chamber side of the ejection port A liquid ejection head characterized by having vertical grooves formed on its inner wall.

(Configuration 2)
The liquid ejection head according to configuration 1, wherein the vertical groove is not formed on an inner wall of the ejection port on a side opposite to the pressure chamber.

(Configuration 3)
The liquid ejection head according to configuration 1 or 2, wherein a plurality of the vertical grooves are formed along the circumferential direction of the ejection port.

(Configuration 4)
4. The liquid ejection head according to any one of configurations 1 to 3, wherein an uneven portion is formed on an inner wall of the ejection port on a side opposite to the pressure chamber.

(Configuration 5)
The ejection port forming substrate is arranged such that a first through hole of the first substrate disposed on the pressure chamber side communicates with a second through hole of the second substrate. and the second substrate are bonded together with an adhesive, and the discharge port includes the first through hole and the second through hole, and the vertical 5. The liquid ejection head according to any one of configurations 1 to 4, wherein the groove is formed on an inner wall of the first through hole on the pressure chamber side.

(Configuration 6)
6. The liquid ejection head according to configuration 5, wherein a vertical groove is formed on the first substrate side of the second through hole.

(Configuration 7)
A plurality of vertical grooves are formed in the first through hole along the circumferential direction of the inner wall of the first through hole, and a plurality of vertical grooves are formed in the second through hole. , the liquid ejection head according to configuration 6, wherein a plurality of the second through holes are formed along the circumferential direction of the inner wall of the second through hole.

(Configuration 8)
It further includes a liquid flow path communicating with the pressure chamber, and a liquid flow path forming substrate on which the liquid flow path is formed, and includes a liquid flow path forming substrate formed with the discharge port forming substrate, the pressure chamber forming substrate, and the liquid flow path forming substrate. Configuration 1 in which the pressure chamber forming substrate and the liquid flow path forming substrate are laminated in order, the pressure chamber forming substrate and the liquid flow path forming substrate are bonded with an adhesive, and a vertical groove is formed on the inner wall of the liquid flow path on the pressure chamber forming substrate side. 8. The liquid ejection head according to any one of 7.

(Configuration 9)
A pressure generating element that generates pressure for discharging liquid, a pressure chamber on which the pressure generated by driving the pressure generating element acts, a pressure chamber forming substrate on which the pressure chamber is formed, and a liquid communicating with the pressure chamber. A liquid ejection head having a flow path and a liquid flow path forming substrate on which the liquid flow path is formed, the pressure chamber forming substrate and the liquid flow path forming substrate being joined with an adhesive, and the liquid flow path forming substrate having the liquid flow path formed therein. A liquid ejection head characterized in that a vertical groove is formed on an inner wall of the liquid flow path on the pressure chamber forming substrate side.

(Configuration 10)
10. The liquid ejection head according to configuration 9, wherein a plurality of the vertical grooves are formed along the circumferential direction of the liquid flow path.

(Configuration 11)
11. The liquid ejection head according to configuration 9 or 10, wherein the vertical groove is filled with the adhesive.

(Configuration 12)
12. The liquid ejection head according to any one of configurations 1 to 11, wherein the vertical groove has a diameter of 1 μm or less.

(Configuration 13)
In a method for manufacturing a liquid ejection head, the method includes: an ejection port forming substrate forming an ejection port for ejecting liquid; and a pressure chamber forming substrate forming a pressure chamber on which pressure acts for ejecting liquid from the ejection port. The pressure in the recess is reduced by forming a recess in the discharge port forming substrate, forming a protective film on the side wall of the recess, and removing a portion of the protective film on the pressure chamber side of the recess. forming the ejection port, comprising the steps of periodically exposing a part of the side wall on the chamber side; and forming the ejection port on the ejection port forming substrate by dry etching the recessed portion. A method for manufacturing a liquid ejection head, characterized in that a vertical groove is formed on the pressure chamber side of the ejection port by the dry etching in the step.

(Configuration 14)
The ejection port forming substrate is arranged such that a first through hole of the first substrate disposed on the pressure chamber side communicates with a second through hole of the second substrate. and the second substrate are bonded together with an adhesive, and the discharge port includes the first through hole and the second through hole, and the discharge port includes the first through hole and the second through hole. forming a first recess in one substrate; forming a protective film on a side wall of the first recess; and removing a part of the protective film on the pressure chamber side of the first recess. The first through hole is formed in the first substrate by periodically exposing a part of the side wall of the first recess on the pressure chamber side, and by dry etching the first recess. and forming a vertical groove on the pressure chamber side of the first through hole by the dry etching in the step of forming the first through hole. Head manufacturing method.

(Configuration 15)
forming a second recess in the second substrate; forming a protective film on a side wall of the second recess; and forming a protective film on the first substrate side of the second recess. a step of periodically exposing a part of the side wall of the second recess on the side of the first substrate by removing a part; and a step of dry etching the second recess. forming the second through hole in the substrate, the dry etching in the step of forming the second through hole forming a vertical groove on the first substrate side of the second through hole. 15. The method for manufacturing a liquid ejection head according to configuration 14.

(Configuration 16)
The pressure chamber forming substrate is configured to be bonded with an adhesive to a liquid flow path forming substrate that forms a liquid flow path communicating with the pressure chamber, and a step of forming a recess in the liquid flow path forming substrate; By forming a protective film on the side wall of the recess of the liquid flow path forming substrate and removing a part of the protective film on the pressure chamber side of the recess of the liquid flow path forming substrate, the liquid flow path forming substrate a step of periodically exposing a part of the side wall of the recess on the pressure chamber side; and a step of forming a liquid flow path in the liquid flow path forming substrate by dry etching the recessed portion of the liquid flow path forming substrate. The liquid ejection head according to any one of configurations 13 to 15, wherein a vertical groove is formed on the pressure chamber side of the liquid flow path by the dry etching in the step of forming the liquid flow path. manufacturing method.

(Configuration 17)
A pressure generating element that generates pressure for discharging a liquid, a pressure chamber forming substrate forming a pressure chamber to which pressure generated by driving the pressure generating element acts, and a liquid flow path communicating with the pressure chamber are formed. A method of manufacturing a liquid ejection head comprising: a liquid flow path forming substrate; forming a recess in the liquid flow path forming substrate; forming a protective film on a side wall of the recess; and forming the pressure chamber of the recess. A step of periodically exposing a part of the side wall of the recess on the pressure chamber side by removing a part of the protective film on the side, and a step of dry etching the recess, are performed on the liquid flow path forming substrate. forming the liquid flow path, and forming a vertical groove on the pressure chamber side of the liquid flow path by the dry etching in the step of forming the liquid flow path. Head manufacturing method.

(Configuration 18)
18. The method for manufacturing a liquid ejection head according to any one of configurations 13 to 17, wherein a plurality of the vertical grooves are formed along the circumferential direction of the ejection port.

(Configuration 19)
19. The method of manufacturing a liquid ejection head according to any one of configurations 13 to 18, wherein the vertical groove has a diameter of 1 μm or less.

(Configuration 20)
17. The method of manufacturing a liquid ejection head according to any one of configurations 13 to 16, wherein an uneven portion is formed on an inner wall of the ejection port on a side opposite to the pressure chamber.

1 Discharge port forming substrate 2 Discharge port 4 Pressure chamber forming substrate 5 Vibration plate 7 Liquid flow path forming substrate 9 Piezoelectric element 10 Liquid flow path 11 Pressure chamber forming substrate 21 Vertical groove

Claims (20)

a discharge port for discharging liquid;
an ejection port forming substrate on which the ejection port is formed;
a pressure generating element that generates pressure to discharge liquid;
a pressure chamber on which pressure generated by driving the pressure generating element acts;
a pressure chamber forming substrate on which the pressure chamber is formed;
A liquid ejection head having:
The discharge port forming substrate and the pressure chamber forming substrate are bonded,
A liquid ejection head characterized in that a vertical groove is formed on an inner wall of the ejection port on the pressure chamber side. 2. The liquid ejection head according to claim 1, wherein the vertical groove is not formed on an inner wall of the ejection port on a side opposite to the pressure chamber. 3. The liquid ejection head according to claim 2, wherein a plurality of the vertical grooves are formed along the circumferential direction of the ejection port. 3. The liquid ejection head according to claim 2, wherein an uneven portion is formed on an inner wall of the ejection port on a side opposite to the pressure chamber. The ejection port forming substrate is arranged such that a first through hole of the first substrate disposed on the pressure chamber side communicates with a second through hole of the second substrate. and the second substrate are bonded together with an adhesive,
The discharge port includes the first through hole and the second through hole,
3. The liquid ejection head according to claim 2, wherein the vertical groove is formed on an inner wall of the first through hole on the pressure chamber side. 6. The liquid ejection head according to claim 5, wherein a vertical groove is formed on the first substrate side of the second through hole. A plurality of vertical grooves are formed in the first through hole along the circumferential direction of the inner wall of the first through hole,
7. The liquid ejection head according to claim 6, wherein a plurality of vertical grooves are formed in the second through hole along a circumferential direction of an inner wall of the second through hole. a liquid flow path communicating with the pressure chamber;
further comprising a liquid channel forming substrate on which the liquid channel is formed,
The discharge port forming substrate, the pressure chamber forming substrate, and the liquid flow path forming substrate are stacked in this order,
The pressure chamber forming substrate and the liquid flow path forming substrate are bonded with an adhesive,
8. The liquid ejection head according to claim 1, wherein a vertical groove is formed in an inner wall of the liquid flow path on the pressure chamber forming substrate side. a pressure generating element that generates pressure to discharge liquid;
a pressure chamber on which pressure generated by driving the pressure generating element acts;
a pressure chamber forming substrate on which the pressure chamber is formed;
a liquid flow path communicating with the pressure chamber;
A liquid ejection head comprising: a liquid flow path forming substrate on which the liquid flow path is formed;
The pressure chamber forming substrate and the liquid flow path forming substrate are bonded with an adhesive,
A liquid ejection head characterized in that a vertical groove is formed on an inner wall of the liquid flow path on the pressure chamber forming substrate side. The liquid ejection head according to claim 9, wherein a plurality of the vertical grooves are formed along the circumferential direction of the liquid flow path. The liquid ejection head according to claim 9 or 10, wherein the longitudinal groove is filled with the adhesive. The liquid ejection head according to claim 2 or 9, wherein the diameter of the vertical groove is 1 μm or less. In a method for manufacturing a liquid ejection head, the method includes: an ejection port forming substrate forming an ejection port for ejecting liquid; and a pressure chamber forming substrate forming a pressure chamber on which pressure acts for ejecting liquid from the ejection port.
forming a recess in the discharge port forming substrate;
forming a protective film on the side wall of the recess;
Periodically exposing a part of the side wall of the recess on the pressure chamber side by removing a part of the protective film on the pressure chamber side of the recess;
forming the ejection port on the ejection port forming substrate by dry etching the recess;
has
A method for manufacturing a liquid ejection head, characterized in that a vertical groove is formed on the pressure chamber side of the ejection port by the dry etching in the step of forming the ejection port. The ejection port forming substrate is arranged such that a first through hole of the first substrate disposed on the pressure chamber side communicates with a second through hole of the second substrate. and the second substrate are bonded together with an adhesive,
The discharge port includes the first through hole and the second through hole,
forming a first recess in the first substrate;
forming a protective film on the side wall of the first recess;
Periodically exposing a part of the side wall of the first recess on the pressure chamber side by removing a part of the protective film on the pressure chamber side of the first recess;
forming the first through hole in the first substrate by dry etching the first recess;
has
14. The method of manufacturing a liquid ejection head according to claim 13, wherein the dry etching in the step of forming the first through hole forms a vertical groove on the pressure chamber side of the first through hole. forming a second recess in the second substrate;
forming a protective film on the side wall of the second recess;
Periodically exposing a part of the sidewall of the second recess on the first substrate side by removing a part of the protective film on the first substrate side of the second recess;
forming the second through hole in the second substrate by dry etching the second recess;
has
15. The method of manufacturing a liquid ejection head according to claim 14, wherein a vertical groove is formed on the first substrate side of the second through hole by the dry etching in the step of forming the second through hole. The pressure chamber forming substrate is bonded with an adhesive to a liquid flow path forming substrate forming a liquid flow path communicating with the pressure chamber,
forming a recess in the liquid flow path forming substrate;
forming a protective film on the side wall of the recess of the liquid flow path forming substrate;
Periodically exposing a part of the side wall of the recess of the liquid flow path forming substrate on the pressure chamber side by removing a portion of the protective film on the pressure chamber side of the recess of the liquid flow path forming substrate. and,
forming a liquid channel in the liquid channel forming substrate by dry etching the recessed portion of the liquid channel forming substrate;
has
14. The method for manufacturing a liquid ejection head according to claim 13, wherein a vertical groove is formed on the pressure chamber side of the liquid flow path by the dry etching in the step of forming the liquid flow path. A pressure generating element that generates pressure for discharging a liquid, a pressure chamber forming substrate forming a pressure chamber to which pressure generated by driving the pressure generating element acts, and a liquid flow path communicating with the pressure chamber are formed. In a method of manufacturing a liquid ejection head having a liquid flow path forming substrate,
forming a recess in the liquid flow path forming substrate;
forming a protective film on the side wall of the recess;
Periodically exposing a part of the side wall of the recess on the pressure chamber side by removing a part of the protective film on the pressure chamber side of the recess;
forming the liquid flow path in the liquid flow path forming substrate by dry etching the recess;
has
A method for manufacturing a liquid ejection head, characterized in that a vertical groove is formed on the pressure chamber side of the liquid flow path by the dry etching in the step of forming the liquid flow path. 17. The method of manufacturing a liquid ejection head according to claim 13, wherein a plurality of the longitudinal grooves are formed along the circumferential direction of the ejection port. 18. The method for manufacturing a liquid ejection head according to claim 13, wherein the longitudinal groove has a diameter of 1 μm or less. 14. The method for manufacturing a liquid ejection head according to claim 13, wherein an uneven portion is formed on an inner wall of the ejection port on a side opposite to the pressure chamber.

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