Liquid dispensing head, liquid dispensing device, and method for manufacturing a liquid dispensing head

Abstract

To provide a liquid ejection head which makes high precision and nozzle plate deformation inhibition compatible and to provide a manufacturing method for the same.SOLUTION: A liquid ejection head has: a nozzle plate provided with an ejection port for ejecting a liquid; a flow-path formation member adjacent to the nozzle plate and provided with a pressure chamber connected to the ejection port via a nozzle; and an energy generation element configured to generate energy for ejecting the liquid into the pressure chamber; wherein the nozzle plate has a resin layer and a deformation inhibition layer whose Young's modulus is 50 GPa or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a liquid ejection head, a liquid ejection device, and a method for manufacturing a liquid ejection head.

Background Art

[0002] In an inkjet printer as a liquid ejection device, in order to achieve higher definition and higher quality printing, it is required to improve the processing accuracy of the liquid ejection head and make the liquid ejection head more high-definition.

[0003] Patent Document 1 describes a method for manufacturing a piezoelectric liquid ejection head in which a nozzle plate of a liquid ejection head is formed of a photosensitive resin, whereby the processing accuracy can be increased compared to processing by etching, and high definition can be achieved. Further, by using a photosensitive resin as the nozzle plate, it becomes possible to pattern the liquid repellent layer and the nozzles on the nozzle plate at once. Thereby, it is also described that, compared with the method of forming the liquid repellent layer after nozzle formation, entry of the water repellent layer into the nozzles can be prevented, so that cost reduction can be achieved in addition to high definition.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the piezoelectric liquid ejection head manufactured by the manufacturing method described in Patent Document 1, since the nozzle plate formed of the photosensitive resin is likely to be deformed, the loss of ejection energy applied to the liquid from the piezoelectric element increases, which may affect ejection.

[0006] Therefore, the present invention aims to provide a liquid discharge head and a method for manufacturing the same that achieve both high resolution and suppression of nozzle plate deformation. [Means for solving the problem]

[0007] To solve the above problems An example of an invention A liquid discharge head comprising: a nozzle plate provided with a discharge port for discharging liquid; a flow path member adjacent to the nozzle plate and provided with a pressure chamber connected to the discharge port via a nozzle; and an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, wherein the nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. Furthermore, the resin layer and the liquid-repellent layer are liquid dispensing heads containing a negative-type photosensitive resin. .

[0008] Also, Another example of the invention A nozzle plate provided with a discharge port for discharging liquid, and a pressure chamber provided adjacent to the nozzle plate and connected to the discharge port via the nozzle, Road section A liquid discharge head having a material and an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, wherein the nozzle plate has a liquid-repellent layer, a photosensitive material layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more, the method for manufacturing the liquid discharge head comprising a step of forming at least one of the photosensitive material layer and the liquid-repellent layer with a dry film resist The method for manufacturing a liquid discharge head is such that the step of joining the deformation-suppressing layer to the flow channel member is performed before the step of forming the photosensitive material layer and the liquid-repellent layer. . [Effects of the Invention]

[0009] According to the present invention, a liquid discharge head, a liquid discharge device, and a method for manufacturing a liquid discharge head are provided that achieve both high resolution and suppression of nozzle plate deformation. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example of a liquid dispensing head of the present invention. [Figure 2] This figure shows an example of a nozzle plate according to the present invention. [Figure 3] This figure shows an example of a nozzle plate according to the present invention. [Figure 4] This figure shows an example of a liquid dispensing head of the present invention. [Figure 5] This figure shows an example of a liquid dispensing head of the present invention. [Figure 6] This figure shows an example of a method for manufacturing a liquid dispensing head according to the present invention. [Figure 7] This figure shows an example of a method for manufacturing a liquid dispensing head according to the present invention. [Figure 8] This figure shows an example of a liquid dispensing head of the present invention. [Modes for carrying out the invention]

[0011] The following describes examples of preferred embodiments of the present invention. The liquid ejection head of the present invention is applicable to devices such as printers, copiers, facsimile machines with communication systems, word processors with printer units, and industrial recording devices combined with various processing devices. The liquid ejection head of the present invention can also be used for applications such as biochip fabrication and electronic circuit printing. Each embodiment described below is a suitable example of the present invention and has various technically preferred constituent elements. However, the present invention is not limited to the embodiments and other examples described below, and various modifications are possible without departing from the technical idea.

[0012] Figure 1 shows an example of a liquid discharge head of the present invention. As shown in Figure 1, the liquid discharge head includes a nozzle plate 10 provided with a discharge port 30 for discharging liquid, and a flow path forming member 1 connected to the nozzle plate 10 and provided with a pressure chamber 2 connected to the discharge port 30 via a nozzle 20. The flow path forming member 1 further includes an energy generating element configured to generate energy for discharging the liquid into the pressure chamber 2. As the energy generating element, elements known in the field of liquid discharge heads can be used as appropriate. For example, heating elements, ultrasonic elements, elements that discharge liquid using electrical or magnetic energy can be used. In this embodiment, the case in which a piezoelectric element 3 is used as the energy generating element will be described. The nozzle plate 10 also has a deformation suppression layer 11 and a photosensitive material layer 12, and may further have a liquid-repellent layer 13. In addition, in the nozzle plate 10, the nozzle 20 has a first part 21 of the nozzle formed in the deformation suppression layer 11 and a second part 22 of the nozzle formed outside the deformation suppression layer 11.

[0013] In liquid dispensing heads using piezoelectric elements, energy loss due to deformation of the nozzle plate is a common problem when the piezoelectric element vibrates to impart dispensing energy to the liquid. Therefore, materials with relatively high Young's moduli, such as Si or stainless steel, are often used for the nozzle plate and flow path forming members that receive the pressure generated from the piezoelectric element through the liquid. On the other hand, in this invention, a photosensitive material layer 12 is used on the nozzle plate with the aim of improving the processing accuracy of the nozzle plate and making the liquid dispensing head more precise. From the viewpoint of improving processing accuracy, the photosensitive material layer 12 is preferably a resin layer using a photosensitive resin, and in particular, from the viewpoint of improving durability, it is more preferably a resin layer using a negative-type photosensitive resin. Examples of photosensitive resins include UV-curable epoxy, acrylic, urethane, polyimide, silicone, or resins having a molecular structure that combines these. Mixtures of these resins may also be used.

[0014] Here, when using the photosensitive material layer 12 made of resin for the nozzle plate 10 for the purpose of improving the processing accuracy, the nozzle plate 10 has a deformation suppression layer 11 for the purpose of compensating for the softness of the nozzle plate 10. Thereby, the effect of reducing the deformation of the nozzle plate 10 when a force is applied to the liquid from the piezoelectric element 3 can be obtained. When discharging the liquid, the pressure applied to the nozzle plate 10 from the piezoelectric element 3 through the liquid is received by the deformation suppression layer 11, thereby suppressing the deformation of the nozzle plate 10.

[0015] The Young's modulus of the deformation suppression layer 11 is preferably 50 GPa or more. Generally, the Young's modulus of resin is lower than that of Si or stainless steel, about 2 GPa for epoxy resin, and even for resins with a large Young's modulus, it is reported to be less than 5 GPa. Therefore, if the Young's modulus of the deformation suppression layer 11 is 50 GPa, it will be more than 10 times that of a resin with a high Young's modulus. Further, the Young's modulus of the deformation suppression layer 11 is more preferably 130 GPa or more, and particularly preferably 193 GPa or more. If it is 130 GPa, a Young's modulus higher than that of Si can be obtained, and if it is 193 GPa or more, a Young's modulus higher than that of stainless steel can be obtained.

[0016] As the material of the deformation suppression layer 11, it is preferable to use Si because it can be processed by either wet etching or dry etching and is easy to improve the processing accuracy. When using a single crystal Si substrate, it is more preferable that the 111 plane, which is a crystal orientation with a high Young's modulus, overlaps the pressure chamber 2. Stainless steel, Ni, Ir, Ta, W, Mo, Cr, Co, Fe, Ru, SiC, TiC, WC, B4C, ZrO2, Al2O3, AlN, Si3N4, TiN, diamond, etc. may also be used. Also, alloys, laminated structures, or mixed materials of these may be used. The processing of these materials may be performed by wet etching or dry etching. When etching is difficult, laser processing, electron beam processing, ion beam processing, sandblasting, cutting processing, etc. may be used. Among these, femtosecond laser processing or water jet laser processing that can reduce the thermal influence during processing is preferable.

[0017] Next, the liquid repellent layer 13 will be described. By using the configuration of the present invention, the nozzle plate 10 has a configuration in which the liquid repellent layer 13, the photosensitive material layer 12, and the deformation suppression layer 11 are laminated in this order from the surface side. Thus, the second portion 22 of the nozzle can be formed in the liquid repellent layer 13 and the photosensitive material layer 12 at once, and an effect of reducing the entry of the first portion 21 of the nozzle into the liquid repellent layer 13 can be obtained, which is more preferable. Also, in order to obtain the liquid repellent effect by the liquid repellent layer 13 and perform good liquid ejection, a configuration in which the liquid repellent layer 13 is exposed on the surface is preferable.

[0018] Note that heat and solvent in the process of forming the liquid repellent layer 13 may affect the photosensitive material layer 12. In the configuration of the present embodiment, since the deformation suppression layer 11 is supported by the photosensitive material layer 12, deformation due to softening and internal stress of the photosensitive material layer 12 is reduced, and an effect of enabling high-definition processing of the nozzle plate 10 can be obtained.

[0019] As the material of the liquid repellent layer 13, for the same reason as the photosensitive material layer 12, it is preferably included with a photosensitive material, more preferably included with a photosensitive resin, and even more preferably included with a negative photosensitive resin. Also, it is more preferable that the photosensitivity of the photosensitive material layer 12 and the liquid repellent layer 13 is equivalent so that their respective dimensions can be adjusted even when the liquid repellent layer 13 and the photosensitive material layer 12 are exposed simultaneously.

[0020] Furthermore, it is preferable that the contact angle of pure water in the deformation suppression layer 11 is less than 90°, and the contact angle of pure water in the photosensitive material layer 12 is also less than 90°. In this case, the liquid is easily wetted by the deformation suppression layer 11 and the photosensitive material layer 12. Therefore, the liquid forms a meniscus within the second part 22 of the nozzle, and the discharge is stabilized. Here, the contact angle of liquids other than pure water tends to be lower than that of pure water, and the contact angle of water-based liquids with additives or liquids containing a large amount of organic solvents is also often less than 90°, so pure water was used as the standard for determining the contact angle. Even if the result of measuring the contact angle of various liquids is less than 90°, the same effect can be obtained. Furthermore, it is preferable that the difference between the contact angle of pure water in the deformation suppression layer 11 and the contact angle of pure water in the photosensitive material layer 12 is small, preferably 50° or less, and more preferably 30° or less. In addition, it is preferable to orient the nozzle 20 of the liquid discharge head downward in the direction of gravity in order to obtain the effect of strengthening the force supplying liquid to the nozzle 20. The state of the meniscus may also be controlled by adjusting the pressure applied to the liquid, either by increasing or decreasing it, using a pump or the like connected to the liquid discharge head.

[0021] Furthermore, a layer that has the effect of strengthening the bond between the liquid-repellent layer 13 and the photosensitive material layer 12 may be introduced within the photosensitive material layer 12, within the liquid-repellent layer 13, or at the interface between the photosensitive material layer 12 and the liquid-repellent layer 13. For example, a layer that strengthens the bond between the liquid-repellent layer 13 and the photosensitive material layer 12 can be introduced by using a silane coupling material or by combining plasma treatment or UV treatment.

[0022] Furthermore, the effect of suppressing deformation of the nozzle plate 10 can be enhanced by adding a filler material to the photosensitive material layer 12 or the liquid-repellent layer 13. As the filler material, a material with a higher Young's modulus than the photosensitive material layer 12 or the liquid-repellent layer 13 is preferred. The Young's modulus of the filler material is preferably 50 GPa or higher, more preferably 130 GPa or higher, and particularly preferably 193 GPa or higher, similar to the deformation-suppressing layer 11.

[0023] Furthermore, as shown in Figure 2(A), the deformation suppression layer 11 may have a support layer 111 with a Young's modulus of 50 GPa or more and a functional layer 112. The functional layer 112 may be formed of multiple layers, may be partially formed relative to the support layer 111, or may be formed inside the deformation suppression layer 11 sandwiched between two or more support layers 111. For example, if the functional layer 112 has a lower reflectivity than the support layer 111 at the wavelength of light that the photosensitive material layer 12 is sensitive to, the effect of reducing the reflected light that the photosensitive material layer 12 receives from the deformation suppression layer 11 can be obtained. In addition, if the surface of the functional layer 112 has siloxane bonds and a silane coupling material is used at the interface between the photosensitive material 12 and the functional layer 13, a chemical bond can be formed, and the effect of improving the adhesion between the photosensitive material layer 12 and the liquid-repellent layer 13 can be obtained. The functional layer 112 may be given functions such as a wiring layer, insulating layer, semiconductor layer, anti-reflective layer, diffusion prevention layer, protective layer, planarization layer, adhesion improvement layer, adhesive layer, or etching stop layer. Alternatively, the functional layer 112 may be patterned to give it functions that combine various electronic components such as circuits, sensors, memories, and batteries. The functional layer 112 may also be made of a material with a Young's modulus of less than 50 GPa.

[0024] Next, the detailed configuration of the nozzle plate 10 will be described. The cross-sectional shape of the nozzle 20 can be any of the various known shapes. Specifically, shapes consisting of a roughly circular shape, an ellipse, a polygon, or various straight lines and curves can be used. In addition, a protrusion may be provided on the discharge port 30 for purposes such as reducing mist.

[0025] In addition, in order to stabilize the position where the meniscus is formed on the outermost surface of the second portion 22 of the nozzle, it is preferable that the inner diameter of the second portion 22 of the second nozzle is smaller than the inner diameter of the first portion 21 of the first nozzle, and that the central axes of the nozzle 21 and the nozzle 22 are substantially the same. Here, as the inner diameter of the nozzle, for example, if the nozzle shape is approximately circular, the diameter may be used, and if it is elliptical, the major axis may be used. Furthermore, as will be described later, if the first portion 21 of the nozzle has a multi-stage structure or a tapered structure, the inner diameter of the surface in contact with the deformation suppression layer 12 may be used. This is preferable because the processing accuracy of the outermost surface of the second portion 22 of the nozzle becomes the lithography accuracy of the photosensitive material 12, and it is easier to improve the processing accuracy compared to the first portion 21 of the nozzle within the deformation suppression layer 11 formed by lithography and etching.

[0026] As described above, when the inner diameter of the second part 22 of the nozzle is smaller than that of the first part 21 of the nozzle, and the central axes of the nozzle 21 and the nozzle 22 are substantially the same, as shown in Figure 2(B), a protruding portion 121 is formed in the photosensitive material layer 12 that does not come into contact with the deformation suppression layer 11. Here, deformation occurs in the photosensitive material layer 12 and the liquid-repellent layer 13 due to internal stress in the photosensitive material layer 12 and the liquid-repellent layer 13. The protruding portion 121 is easily deformed because it is not fixed to the deformation suppression layer 11, and the larger the length a of the protruding portion 121, the greater the deformation due to the internal stress. Here, it is more preferable if the length a of the protruding portion is less than or equal to the total thickness of the photosensitive material layer 12 and the liquid-repellent layer 13, as this reduces the proportion of the deformable protruding portion and reduces the deformation of the protruding portion 121. Furthermore, by reducing the ratio of the length a of the protruding portion to the inner diameter of the first part 21 of the nozzle, the effect of reducing hardened foreign matter inside the nozzle can be obtained. Therefore, the length a of the protruding portion 121 is preferably 6% or less of the inner diameter of the first portion 21 of the nozzle, more preferably 5% or less, even more preferably 4% or less, and even more preferably 3% or less. In this case, the difference between the inner diameter of the first portion 21 of the nozzle and the inner diameter of the second portion 22 of the nozzle is preferably 12% or less of the inner diameter of the first portion 21 of the nozzle, more preferably 10% or less, even more preferably 8% or less, and even more preferably 6% or less. Here, hardened foreign matter inside the nozzle refers to foreign matter in which the photosensitive material has hardened in an area where hardening of the photosensitive material is not desired.

[0027] Furthermore, by making the thickness of the deformation-suppressing layer 11 greater than the combined thickness of the photosensitive material layer 12 and the liquid-repellent layer 13, the deformation-suppressing effect of the nozzle plate 10 is enhanced, but this changes the length of the nozzle 20, which affects the discharge. Therefore, in order to achieve both deformation suppression and good liquid discharge, the thickness of the deformation-suppressing layer 11 is preferably 200 μm or less, more preferably 100 μm or less, even more preferably 50 μm or less, and even more preferably 20 μm or less. In addition, to effectively obtain the deformation-suppressing effect, the thickness of the deformation-suppressing layer 11 is preferably 5 μm or more, and more preferably 10 μm or more.

[0028] Furthermore, the total thickness of the photosensitive material layer 11 and the liquid-repellent layer 13 is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. In this case, reducing the total thickness of the photosensitive material layer 11 and the liquid-repellent layer 13 may reduce abnormal liquid discharge. In addition, in order to stably exhibit liquid repellency, the total thickness is preferably 0.02 μm or more, and more preferably 0.05 μm or more.

[0029] Next, the detailed configuration of the nozzle 20 will be described. Figures 3(A) and 3(B) are enlarged views of the nozzle 20 in the present invention.

[0030] As shown in Figure 3(A), by making the first part 21 of the nozzle a multi-stage structure, the design range that achieves both deformation suppression and good discharge can be broadened. Specifically, even if the deformation suppression layer 11 is made thicker to suppress deformation, it is possible to adjust the design range of the liquid discharge speed and discharge volume, or to improve the circulation efficiency when circulating the liquid to prevent discharge failure. Similar effects can be obtained if the first part 21 of the nozzle has a tapered shape, and a combination of a multi-stage structure and a tapered structure may also be used.

[0031] As shown in Figure 3(A), it is preferable to form a nozzle wall adhesion portion 122 in which the photosensitive material 12 enters the first portion 21 of the nozzle from the second portion 22 of the nozzle. This increases the contact area between the photosensitive material layer 12 and the deformation suppression layer 11, resulting in improved adhesion. The first portion 21 of the nozzle may have a multi-stage structure, with some stages in contact with the nozzle wall adhesion portion 122 and others not. Whether the photosensitive material layer 12 is formed to enter the first portion 21 of the nozzle can be determined by observing the cross-section of the nozzle 20 or by compositional analysis.

[0032] As shown in Figure 3(B), a tapered shape may be formed between the photosensitive material layer 12 and the liquid-repellent layer 13. A larger taper angle θ can increase the ejection speed, so it is more preferable to have a taper angle of 2° or more, even more preferable to have a taper angle of 5° or more, and even more preferable to have a taper angle of 10° or more. Here, the photosensitive material layer 12 may have a multi-stage structure, or a structure that combines a multi-stage structure with a tapered shape.

[0033] Next, an example of the configuration of the discharge head in the present invention will be described. Figure 4 is a diagram showing an example of the liquid discharge head of the present invention. As shown in Figure 4(A), a nozzle plate 10 is connected to a flow path forming member 1 having a pressure chamber 2, and the pressure chamber 2 and the nozzle plate 10 are adjacent to each other. When the piezoelectric element 3 is driven to apply discharge energy to the liquid, pressure is applied to the nozzle plate 10 through the liquid. At this time, the deformation suppression layer 11 of the present invention works effectively, and the deformation of the nozzle plate 10 is suppressed.

[0034] As shown in Figure 4(B), a configuration in which a flow path exists between the piezoelectric element 3 and the nozzle plate 10 can also be used. In this case as well, when the piezoelectric element 3 is driven and energy is applied to the liquid, pressure is applied to the nozzle plate 10 through the liquid. Therefore, the flow path can be considered as a pressure chamber 2, and the deformation suppression layer 11 of the present invention works effectively.

[0035] As shown in Figure 4(C), another configuration can be used in which the piezoelectric element 3 and the nozzle plate 10 are separated. In this case as well, the energy applied to the liquid by driving the piezoelectric element 3 is applied to the nozzle plate 10 through the liquid, and can therefore be considered as part of the pressure chamber 2, including the flow path. Thus, the deformation suppression layer 11 of the present invention works effectively. Furthermore, pressure is also propagated through the liquid in the direction of the liquid supply port 31, which is a flow path that supplies liquid to the pressure chamber 2. In this configuration, if there is a portion adjacent to the nozzle plate 10 in the middle of the flow path of the liquid supply port 31, the deformation suppression layer 11 of the present invention, which applies pressure to the nozzle plate 10 through the liquid, works effectively.

[0036] Furthermore, the liquid discharge head may be processed in addition to the nozzle 20. Figure 5 shows an example of the liquid discharge head of the present invention. Figure 5(A) is a cross-sectional view, and Figure 5(B) is a top view corresponding to A-A' in Figure 5(A).

[0037] As shown in Figure 5(A), the deformation suppression layer 11 is composed of a support layer 111 and a functional layer 112. The functional layer 112 can be used, for example, as an etching stop layer. A first portion 21 of the nozzle is formed on the deformation suppression layer 11. A second portion 22 of the nozzle is also formed on the photosensitive material layer 12 and the liquid-repellent layer 13. The flow path forming member 1 has a pressure chamber 2, a piezoelectric element 3, and a liquid supply port 31.

[0038] Here, a processing pattern other than the nozzle 20 can be formed on at least one of the deformation suppression layer 11, the photosensitive material layer 12, and the liquid-repellent layer 13 to provide various functions. For example, forming a slit 41 on the nozzle plate 10 can have the effect of balancing the rigidity of the entire substrate, or when the nozzle plate 10 and the flow path forming member 1 are joined with an adhesive, it can have the effect of regulating the flow of the adhesive or improving adhesion through an anchoring effect. Alternatively, a pattern 42 may be formed on the nozzle plate 10. In this case, removing the photosensitive material layer 12 and the liquid-repellent layer 13 near the pattern 42 can further improve the visibility of the pattern 42. In areas without the processing pattern 42, a pattern 43 can be formed by processing the photosensitive material layer 12 and the liquid-repellent layer 13. Since these processing patterns can be processed simultaneously with the first part 21 or the second part 22 of the nozzle, processing is possible in the present invention without introducing a new processing step. These processing patterns can be used for identifying wafers or chips being processed, measuring the width and depth of the patterns, monitoring the processing state during or after processing, and aligning wafers or chips using the processing patterns as alignment marks.

[0039] Next, an example of the method for manufacturing a liquid dispensing head according to the present invention will be described. Figure 6 shows an example of the method for manufacturing a liquid dispensing head according to the present invention.

[0040] As shown in Figure 6(A), a structure 120 is prepared, which includes a flow channel forming member 1 having a pressure chamber 2 and a piezoelectric element 3, and a deformation suppression layer 11 having a first portion 21 of a nozzle. While there are various methods for joining the flow channel forming member 1 and the deformation suppression layer 11, such as adhesive bonding, anodic bonding, and surface activation bonding, it is preferable to use adhesive bonding because it increases the degree of freedom in selecting the material of the deformation suppression layer 11 and in processing.

[0041] Here, by using Si as the deformation suppression layer 11 and processing the first portion 21 of the nozzle using the Bosch process, a scallop can be formed on the wall surface of the first portion 21 of the nozzle. In the process of forming the photosensitive material layer 12, which will be described later, it is preferable to process the scallop so that it comes into contact with the photosensitive material layer 12, as this improves the adhesion between the deformation suppression layer 11 and the photosensitive material layer 12 due to the anchoring effect.

[0042] Next, as shown in Figure 6(B), a photosensitive material layer 12 is formed on the structure 120. The photosensitive material layer 12 can be formed by known methods, but it is preferable to form it using a dry film resist because it is easier to control the amount that enters the first portion 21 of the nozzle or the pressure chamber 2. In this case, the shape of the first portion 21 of the nozzle of the deformation suppression layer 11 can be made multi-stage, and the photosensitive material layer 12 can be formed to fill the uppermost stage of the first portion 21 of the nozzle, thereby controlling the amount that the photosensitive material enters the second and subsequent stages of the first portion 21 of the nozzle.

[0043] Furthermore, the photosensitive material layer 12 may have a multilayer structure comprising multiple materials with different photosensitivity. For example, by arranging a highly photosensitive layer on the liquid-repellent layer 13 side and a less photosensitive layer on the deformation-suppressing layer 11 side, it is possible to reduce the reflective influence that the liquid-repellent layer 13 receives from the photosensitive material layer 12 and the deformation-suppressing layer 11 during exposure after the formation of the liquid-repellent layer 13, as described later.

[0044] Next, as shown in Figure 6(C), a liquid-repellent layer 13 is formed. Here, the liquid-repellent layer 13 can be formed by known methods, such as slit coating, spin coating, spray coating, or screen printing. To reduce the deformation of the photosensitive material layer 12 when forming the liquid-repellent layer 13, it is preferable to form the liquid-repellent layer 13 with a reduced amount of solvent, and it is more preferable to form the liquid-repellent layer 13 with a dry film resist. Another method to reduce the deformation of the photosensitive material layer 12 is to form the photosensitive material layer 12 so that it enters the first portion 21 of the nozzle. This reduces the flow of the photosensitive material due to the solvent or heat during the formation of the liquid-repellent layer 13. Furthermore, when forming the liquid-repellent layer 13 by coating, it is preferable that the solvent used during the formation of the liquid-repellent layer 13 has a composition that does not easily dissolve the photosensitive material layer 12. By making such efforts, the effect of reducing the deformation of the photosensitive material layer 12 can be obtained.

[0045] Furthermore, by irradiating the liquid-repellent layer 13 with energy after its formation, the liquid-repellent components within the liquid-repellent layer 13 can be segregated to the surface, thereby improving the liquid-repellent performance. Energy irradiation can be performed using heat treatment with a hot plate or oven. Alternatively, electromagnetic waves such as lamps, lasers, or microwaves may be used, or irradiation with electron beams, ion beams, gas jets, or plasma treatment may be used. These energies may be irradiated continuously or instantaneously at high power.

[0046] Next, as shown in Figure 6(D), the second portion 22 of the nozzle is formed on the liquid-repellent layer 13 and the photosensitive material layer 12. The second portion 22 of the nozzle can be formed using known methods. For example, a series of steps such as exposure, PEB (Post-exposure bake), and development can be used. In this case, in various heat treatments, including PEB, it is preferable to gradually increase the heating temperature because this reduces the deformation of the photosensitive material layer 12. Additional heat treatment may be performed after development.

[0047] Next, a different embodiment of the method for manufacturing a liquid dispensing head according to the present invention will be described. Figure 7 shows an example of the method for manufacturing a liquid dispensing head according to the present invention. As shown in Figure 7(A), a structure 120 is prepared. Next, as shown in Figure 7(B), a film 14 formed on a support member 50 is transferred to the structure 120. Here, the film 14 can be a laminate of a layer for the photosensitive material layer 12 and a layer for the liquid-repellent layer 13.

[0048] Next, as shown in Figure 7(C), the film 14 is patterned while peeling off the support member 50 to form the second portion 22 of the nozzle. By applying force to the film 14, which has been transferred to cover the first portion 21 of the nozzle, through the support member 50, cohesive failure occurs in the film 14 at the edge of the first portion 21 of the nozzle, and the film 14 is patterned to form the second portion 22 of the nozzle. Here, in order to pattern the film 14 so that the second portion 22 of the nozzle does not shift from the edge of the first portion 21 of the nozzle, it is effective to make the thickness of the film 14 thin. For this reason, the thickness of the film 14 is preferably 1 μm or less, more preferably 0.5 μm or less, even more preferably 0.2 μm or less, and even more preferably 0.1 μm or less.

[0049] Furthermore, as shown in Figure 7(D), by irradiating the film 14 with energy, the liquid-repellent component can be segregated, creating a state in which the photosensitive material layer 12 and the liquid-repellent layer 13 are sufficiently separated. Here, the liquid-repellent layer 13 has a composition in which the contact angle with pure water is 90° or more, and the photosensitive material layer 12 has a composition in which the contact angle with pure water is less than 90°. Therefore, whether or not phase separation has occurred can be evaluated by scraping the photosensitive material layer 12 and the liquid-repellent layer 13 and measuring the contact angle with pure water. Alternatively, it can be estimated from the compositional analysis in the depth direction of the nozzle plate 10.

[0050] Furthermore, the film 14 can also be made from a mixture of the raw materials for the photosensitive material layer 12 and the liquid-repellent layer 13. Similar to the case where a laminate of the photosensitive material layer 12 and the liquid-repellent layer 13 is used as the film 14, by irradiating the film 14 with energy, a state in which the photosensitive material layer 12 and the liquid-repellent layer 13 are sufficiently separated can be formed. By using this embodiment in which the photosensitive material layer 12 and the liquid-repellent layer 13 are formed in one step, the total thickness of the photosensitive material layer 12 and the liquid-repellent layer 13 can be made thinner, and in addition, the number of forming steps can be reduced. Moreover, if liquid materials at room temperature (25°C) are used as the mixture of the raw materials for the photosensitive material layer 12 and the liquid-repellent layer 13, phase separation at room temperature becomes possible, resulting in a simplified process.

[0051] In the process of forming the nozzle 20, exposure may be performed by irradiating the entire surface, which simplifies the process. Furthermore, PEB, development, or additional heat curing can be performed. Development is not necessarily required, and a heat treatment that combines PEB and additional heat curing may be performed, and in either case, the process is simplified.

[0052] Regarding the order of forming each layer, as shown in Figures 6 and 7, it is preferable to form the photosensitive material layer 12 and the liquid-repellent layer 13 after joining the deformation-suppressing layer 11 and the flow channel forming member 1. If the photosensitive material layer 12 and the liquid-repellent layer 13 are formed on the deformation-suppressing layer 11 first, the deformation-suppressing layer 11 will be processed as a standalone unit, but since the deformation-suppressing layer 11 alone is thin and difficult to handle, a support member is often required. Therefore, by joining the deformation-suppressing layer 11 to the flow channel forming member 1 first, the flow channel forming member 1 acts as a support member for the deformation-suppressing layer 11, making it easier to handle.

[0053] In the above embodiment, a liquid discharge head using a piezoelectric element as an energy generating element for discharging liquid was described. However, the present invention is also effective when using an energy generating element other than a piezoelectric element. Here, Figure 8 shows a liquid discharge head in which a heating element is used as the energy generating element.

[0054] As shown in Figure 8, the liquid discharge head includes a flow path forming member 1 and a nozzle plate 10 connected to the flow path forming member 1. The flow path forming member 1 includes a pressure chamber 2, a heater 4, and a liquid supply port 31, while the nozzle plate 10 includes a deformation suppression layer 11, a photosensitive material layer 12, and a liquid-repellent layer 13. The nozzle plate 10 has a nozzle 20, which has a first nozzle portion 21 formed in the deformation suppression layer 11 and a second nozzle portion 22 formed outside the deformation suppression layer 11. In this configuration as well, similar to a liquid discharge head using a pressure element as an energy generating element, the deformation suppression layer 11 provides the effect of suppressing the deformation of the nozzle plate 10. [Examples]

[0055] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0056] <Examples> A liquid discharge head with the configuration shown in Figure 1 was formed. A Si substrate was used as the channel forming member 1, and a piezoelectric element 3 made of PZT (lead zirconate titanate), a drive circuit (not shown), a liquid supply port (not shown), and a pressure chamber 2 were formed thereon. Si was used as the material for the deformation suppression layer 11. After joining the channel forming member 1 and the deformation suppression layer 11 using an adhesive, the deformation suppression layer 11 was thinned to a thickness of 100 μm. Subsequently, a first portion 21 of a nozzle with a diameter of 30 μm was formed on the deformation suppression layer 11 using a Bosch process with a photoresist as the masking material.

[0057] Next, a negative-type photosensitive epoxy resin, prepared as a dry film with a thickness of 5 μm, was transferred onto the deformation-suppressing layer 11 as the photosensitive material layer 12. Subsequently, a liquid-repellent agent containing the negative-type photosensitive epoxy resin was applied to the photosensitive material layer 12 using a slit coater to form a liquid-repellent layer 13, which was then baked. Next, the photosensitive material layer 12 and the liquid-repellent layer 13 were exposed using a photomask sized to a diameter of 29 μm, and the second part 22 of the nozzle was formed by PEB, development, and additional heat treatment. Through these steps, a liquid ejection head was obtained. The obtained liquid ejection head was attached to the inkjet printer body (not shown), and an ink tank (not shown) containing ink was attached to the liquid ejection head. In this way, an inkjet printer as a liquid ejection device was configured.

[0058] <Comparative Example> A liquid ejection head was formed in which the deformation suppression layer 11 shown in Figure 1 was replaced with a photosensitive resin. A negative-type photosensitive epoxy resin was used as the photosensitive resin. The Young's modulus of the epoxy resin was 50 GPa or less, which is required for the deformation suppression layer of the present invention. The channel forming member 1 was formed with the same configuration as in the above example. For the member corresponding to the deformation suppression layer 11, five sheets of negative-type photosensitive epoxy resin, which had been dry-filmed to a thickness of 20 μm, were laminated together. Next, the dry film was exposed, PEB and developed to form the first part 21 of a nozzle with a diameter of 30 μm. Then, the photosensitive material layer 12, the liquid-repellent layer 13 and the second part 22 of the nozzle were formed in the same manner as in the example to obtain a liquid ejection head. An inkjet printer was configured in the same manner as in the example using the obtained liquid ejection head. When the inkjet printers of the example and the comparative example were compared, it was found that the ejection frequency could be increased when using the liquid ejection head of the example compared to when using the liquid ejection head of the comparative example. Furthermore, in the comparative example liquid dispensing head, there were cases where the rate of decreased dispensing speed and the rate of non-dispensing increased. [Explanation of Symbols]

[0059] 1. Flow channel forming member 2. Pressure chamber 3. Piezoelectric element 4 Heater 10 Nozzle Plates 11 Deformation suppression layer 12 Photosensitive material layer 13 Liquid repellent layer 111 Supporter layer 112 Functional Layers 20 nozzles 21. First part of the nozzle 22. Second part of the nozzle 30 outlet 31 Liquid supply port 50 Support member 121 Protruding section a. Length of the protruding part 122 Nozzle wall contact area

Claims

1. A nozzle plate provided with an outlet for dispensing liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. A liquid dispensing head in which the resin layer and the liquid-repellent layer contain a negative-type photosensitive resin.

2. A nozzle plate provided with a discharge port for discharging liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The nozzle has a first portion formed in the deformation-suppressing layer and a second portion formed outside the deformation-suppressing layer. The second portion has a smaller inner diameter than the first portion, A liquid dispensing head in which the difference between the inner diameter of the first portion and the inner diameter of the second portion is 12% or less of the inner diameter of the first portion.

3. A nozzle plate provided with a discharge port for dispensing liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The contact angle of pure water in the deformation-suppressing layer is less than 90°, and A liquid dispensing head in which the contact angle of pure water in the resin layer is less than 90°.

4. A nozzle plate provided with a discharge port for dispensing liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. A liquid dispensing head in which the thickness of the deformation-suppressing layer is greater than the combined thickness of the liquid-repellent layer and the resin layer.

5. A nozzle plate provided with a discharge port for dispensing liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. A liquid dispensing head in which the total thickness of the liquid-repellent layer and the resin layer is 10 μm or less.

6. A nozzle plate provided with a discharge port for dispensing liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The nozzle has a first portion formed in the deformation-suppressing layer and a second portion formed outside the deformation-suppressing layer. A liquid dispensing head in which the resin layer is formed to extend from the second portion into the first portion.

7. A nozzle plate provided with a discharge port for discharging liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, The nozzle plate comprises a liquid-repellent layer, a resin layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The deformation-suppressing layer comprises a support layer with a Young's modulus of 50 GPa or more, and a functional layer. A liquid dispensing head wherein, in light of wavelengths to which the resin layer is sensitive, the functional layer has a lower reflectivity than the support layer.

8. The liquid dispensing head according to any one of claims 1 to 7, wherein the energy generating element is a piezoelectric element.

9. The liquid discharge head according to any one of claims 1 to 7, wherein in the nozzle plate, the liquid-repellent layer is exposed on the surface on which the discharge port is provided, and the liquid-repellent layer, the resin layer, and the deformation-suppressing layer are laminated in that order from the surface side.

10. The liquid dispensing head according to any one of claims 2 to 7, wherein the resin layer and the liquid-repellent layer include a negative-type photosensitive resin.

11. The nozzle has a first portion formed in the deformation-suppressing layer and a second portion formed outside the deformation-suppressing layer. The second portion has a smaller inner diameter than the first portion, The liquid discharge head according to any one of claims 1, 3 to 7, wherein the difference between the inner diameter of the first portion and the inner diameter of the second portion is 12% or less of the inner diameter of the first portion.

12. The contact angle of pure water in the deformation-suppressing layer is less than 90°, and The liquid dispensing head according to any one of claims 1, 2, 4 to 7, wherein the contact angle of pure water in the resin layer is less than 90°.

13. The liquid dispensing head according to any one of claims 1 to 3 or 5 to 7, wherein the thickness of the deformation suppression layer is greater than the combined thickness of the liquid-repellent layer and the resin layer.

14. The liquid dispensing head according to any one of claims 1 to 4, 6, or 7, wherein the total thickness of the liquid-repellent layer and the resin layer is 10 μm or less.

15. The liquid discharge head according to any one of claims 1 to 7, wherein the nozzle formed in the deformation suppression layer has at least one of a multi-stage structure and a tapered structure.

16. The nozzle has a first portion formed in the deformation-suppressing layer and a second portion formed outside the deformation-suppressing layer. The liquid dispensing head according to any one of claims 1 to 5, 7, wherein the resin layer is formed to extend from the second portion into the first portion.

17. The deformation-suppressing layer comprises a support layer with a Young's modulus of 50 GPa or more, and a functional layer. The liquid dispensing head according to any one of claims 1 to 6, wherein the functional layer has a lower reflectivity than the support layer in light of wavelengths to which the resin layer is sensitive.

18. A liquid dispensing device having a liquid dispensing head according to any one of claims 1 to 7.

19. A nozzle plate provided with an outlet for dispensing liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, A method for manufacturing a liquid discharge head, wherein the nozzle plate comprises a liquid-repellent layer, a photosensitive material layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The process includes forming at least one of the photosensitive material layer and the liquid-repellent layer with a dry film resist, A method for manufacturing a liquid discharge head, wherein the step of joining the deformation suppression layer to the flow channel member is performed before the step of forming the photosensitive material layer and the liquid-repellent layer.

20. A nozzle plate provided with a discharge port for discharging liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, A method for manufacturing a liquid discharge head, wherein the nozzle plate comprises a liquid-repellent layer, a photosensitive material layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The process includes forming at least one of the photosensitive material layer and the liquid-repellent layer with a dry film resist, The nozzle has a first portion formed in the deformation suppression layer and a second portion formed outside the deformation suppression layer. A method for manufacturing a liquid dispensing head, comprising the step of forming the photosensitive material layer such that the photosensitive material layer extends from the second portion into the first portion.

21. A nozzle plate provided with a discharge port for discharging liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, A method for manufacturing a liquid discharge head, wherein the nozzle plate comprises a liquid-repellent layer, a photosensitive material layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. The process includes forming at least one of the photosensitive material layer and the liquid-repellent layer with a dry film resist, The nozzle has a first portion formed in the deformation suppression layer and a second portion formed outside the deformation suppression layer. A method for manufacturing a liquid dispensing head, comprising the step of forming at least one of the photosensitive material layer and the liquid-repellent layer with a dry film resist, wherein the second portion of the nozzle is formed by patterning the dry film resist while peeling it off the support member.

22. A nozzle plate provided with a discharge port for discharging liquid, A flow path member having a pressure chamber adjacent to the nozzle plate and connected to the discharge port via the nozzle, A liquid discharge head having an energy generating element configured to generate energy for discharging the liquid into the pressure chamber, A method for manufacturing a liquid discharge head, wherein the nozzle plate comprises a liquid-repellent layer, a photosensitive material layer, and a deformation-suppressing layer having a Young's modulus of 50 GPa or more. A step of forming at least one of the photosensitive material layer and the liquid-repellent layer with a dry film resist, A step of irradiating the liquid-repellent layer with energy to segregate the liquid-repellent components within the liquid-repellent layer, A method for manufacturing a liquid dispensing head having

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