Manufacturing method for element substrates

Abstract

To provide an element substrate which exhibits stable discharge performance.SOLUTION: An element substrate manufacturing method is for manufacturing an element substrate which is used for a liquid discharge head for discharging a liquid to a recorded medium, which has a nozzle 45 including an outlet opposite to the recorded medium and a pressure generation chamber 44 communicating with the nozzle 45, and which is provided with a substrate subjected to liquid-repellent treatment on a part of the surface of a side opposite to the recorded medium, and a generation element 22 that generates energy for discharging the liquid in the pressure generation chamber from the outlet. This method comprises: a liquid-repellent treatment step of executing liquid-repellent treatment on the substrate; and a liquid-repellent region removal step of removing a part of a liquid-repellent region 25 subjected to the liquid-repellent treatment so as to expose a non-liquid-repellent region 26 not subjected to the liquid-repellent treatment on a surface opposite to the recorded medium of the substrate.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an element substrate, a liquid ejection head including the element substrate, and a method for manufacturing an element substrate. [Background Art]

[0002] A recording apparatus (liquid ejection apparatus) using an inkjet method performs recording by causing ink (recording liquid) droplets to be ejected from ejection ports formed on an element substrate toward a recording medium, fly to, and adhere to the recording medium, by means of a liquid ejection head including the element substrate. In such an element substrate, liquid-repellent treatment has been conventionally performed in the vicinity of ejection ports on a surface where the ejection ports are formed, in order to prevent a reduction in ejection performance caused by droplets adhering to the vicinity of the ejection ports.

[0003] Patent Document 1 discloses a method for patterning a liquid-repellent film as a method for performing liquid-repellent treatment on a substrate constituting an element substrate. When patterning is performed using a resist mask, after surface treatment and hydrophilic treatment are performed, a resist is formed, patterned, and subjected to fluorine plasma treatment, whereby liquid repellency is restored. [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Laid-Open No. 2010-5994 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, in the above method, since ink repellency is restored after hydrophilic treatment, the liquid-repellent treatment performance is not stable and tends to vary.

[0006] Therefore, an object of the present invention is to provide an element substrate having stable ejection performance. [Means for Solving the Problem]

[0007] To achieve the above objective, the method for manufacturing the element substrate of the present invention is as follows: A method for manufacturing an element substrate used in a liquid discharge head that discharges liquid onto a recording medium, A substrate having a nozzle including an outlet facing the recording medium, and a pressure generating chamber communicating with the nozzle, wherein a portion of the outlet surface on which the outlet is formed is treated with a liquid-repellent coating, A generating element that generates energy to discharge the liquid in the pressure generating chamber from the discharge port, In a method for manufacturing an element substrate, A liquid-repellent treatment step is performed on the substrate, A liquid-repellent region removal step, which removes a portion of the liquid-repellent region that has been treated with the liquid-repellent treatment, such that a non-liqui-repellent region that has not been treated with the liquid-repellent treatment is exposed on the surface of the substrate facing the recording medium, Includes, The substrate has a protrusion that extends from the ejection port surface toward the recording medium side, and the protrusion has a height of 10 μm or more from the ejection port surface. The liquid-repellent region removal step is characterized by removing the upper part of the protrusion that has been treated with the liquid-repellent process by grinding. Furthermore, in order to achieve the above objective, the method for manufacturing the element substrate of the present invention is as follows: A method for manufacturing an element substrate used in a liquid discharge head that discharges liquid onto a recording medium, A substrate having a nozzle including an outlet facing the recording medium, and a pressure generating chamber communicating with the nozzle, wherein a portion of the outlet surface on which the outlet is formed is treated with a liquid-repellent coating, A generating element that generates energy to discharge the liquid in the pressure generating chamber from the discharge port, In a method for manufacturing an element substrate, A mask bonding step in which a hard mask is bonded to the ejection port surface of the substrate, A mask portion removal step, which removes the portion of the hard mask facing the nozzle, A liquid-repellent treatment step is performed on the substrate, a liquid-repellent region removing step of removing a part of the liquid-repellent region subjected to the liquid-repellent treatment such that a non-liquid-repellent region not subjected to the liquid-repellent treatment is exposed on a surface of the substrate facing a recording medium; characterized by comprising 。

Effect of the Invention

[0008] According to the present invention, an element substrate having stable ejection performance can be provided.

Brief Description of Drawings

[0009] [Figure 1] FIG. 1 is a perspective view of the element substrate according to the first embodiment. [Figure 2] FIGS. 2A and 2B are diagrams illustrating a method for manufacturing the element substrate according to the first embodiment. [Figure 3] FIGS. 3A and 3B are diagrams illustrating a method for manufacturing an element substrate according to a second embodiment. [Figure 4] FIG. 4 is a perspective view of an element substrate according to a third embodiment. [Figure 5] FIGS. 5A and 5B are diagrams illustrating a method for manufacturing an element substrate according to the third embodiment. [Figure 6] FIG. 6 is a top view of the element substrate according to the third embodiment. [Figure 7] FIGS. 7A and 7B are diagrams illustrating a method for manufacturing an element substrate according to a fourth embodiment. [Figure 8] FIGS. 8A and 8B are diagrams illustrating a method for manufacturing an element substrate according to a fifth embodiment.

Mode for Carrying Out the Invention

[0010] Hereinafter, with reference to the drawings, modes for carrying out the present disclosure will be exemplarily described in detail. However, the dimensions, materials, shapes, and relative arrangements of components described in the following embodiments should be appropriately changed depending on the configuration of an apparatus to which the disclosure is applied and various conditions. That is, the scope of the present disclosure is not intended to be limited to the following embodiments.

[0011] (First Embodiment) The liquid ejection head according to the present invention is applicable to apparatuses such as printers, copying machines, and facsimile machines serving as recording apparatuses (liquid ejection apparatuses). In the present embodiment, a liquid ejection head provided in an inkjet printer as a recording apparatus will be described as an example. In addition to the liquid ejection head, the recording apparatus is provided with a liquid storage portion that stores liquid such as ink to be supplied to the liquid ejection head, a conveying mechanism for a recording medium on which recording is performed, and the like. Further, the liquid ejection head may be mounted on the recording apparatus as a cartridge formed integrally with a liquid storage portion that supplies liquid to the liquid ejection head. Further, as the liquid ejection head, a piezoelectric element may be used as a generating element for generating energy for ejecting liquid, or an element that generates thermal energy such as a heater may be used. Hereinafter, an embodiment in which the present invention is applied to a liquid ejection head using a piezoelectric element will be described.

[0012] <Configuration of Element Substrate> FIG. 1 is a schematic diagram of an element substrate 100 according to the first embodiment. In the element substrate 100 serving as a substrate for a liquid ejection head, a piezoelectric element 2 for generating energy to eject liquid such as ink and a vibration plate 3 are disposed on a substrate 1. Further, the substrate 1 is formed with a flow path 7 through which liquid passes, a bubble generation chamber 8 serving as a pressure generation chamber, and a nozzle 4 including an ejection port 4a facing a recording medium, which are communicated with each other. The nozzle 4 extends in a facing direction in which the ejection port 4a faces the recording medium, and the liquid that has passed through the flow path 7, the bubble generation chamber 8, and the nozzle 4 is ejected toward the recording medium such as recording paper. A surface of the substrate 1 facing the recording medium side includes an ejection port surface 1a on which the ejection port 4a of the nozzle 4 is formed as a first surface, and a protruding surface 1b protruding toward the recording medium side from the ejection port surface 1a as a second surface. That is, the substrate 1 is formed with a protruding portion 1c protruding toward the recording medium side with respect to the ejection port surface 1a. In the present embodiment, the ejection port surface 1a is subjected to liquid repellent treatment to form an ink repellent region (liquid repellent region) 5. On the other hand, the protruding surface 1b is a non-ink-repellent region (non-liquid-repellent region) 6 that has not been subjected to liquid repellent treatment, and a protective member 9 for protecting the nozzle plate is adhesively bonded onto the protruding surface 1b.

[0013] The element substrate 100 is connected to a housing that contains liquid, and liquid supplied from the housing passes through liquid passages, such as the flow path 7, within the substrate 1, causing the liquid to be discharged from the nozzle 4 of the element substrate 100 toward the recording medium. The element substrate 100 is electrically connected to an electrical wiring member and discharges liquid according to instructions received from a recording device via the electrical wiring member.

[0014] Substrate 1 uses a silicon substrate on which a piezoelectric element, electrical wiring, liquid channels including a foaming chamber, and a diaphragm are formed using MEMS (Micro Electro Mechanical Systems) technology. Substrate 1 is formed by further bonding a silicon substrate on which an outlet is formed to the silicon substrate. In other words, substrate 1 is formed by bonding various substrates, such as a channel substrate and an actuator substrate. Substrate 1 has passages through which liquid flows, as well as spaces for the piezoelectric element 2 and electrodes for operating the piezoelectric element 2.

[0015] The passage through which the liquid flows within the substrate 1 consists of a flow path 7, a foaming chamber 8, and a nozzle 4. The flow path 7 communicates with a housing that contains the liquid, and the liquid flows from the flow path 7 to the foaming chamber 8. The foaming chamber 8 is a liquid chamber that stores the liquid discharged from the nozzle 4 and is formed in communication with the nozzle 4. The nozzle 4 is a passage that extends parallel to the stacking direction of the substrate 1, and multiple nozzles are formed on the substrate 1.

[0016] The piezoelectric elements 2 are for generating vibrational energy for liquid discharge and are provided corresponding to each of the nozzles 4. The diaphragm 3 is positioned to face the foaming chamber 8 and is vibrated by the piezoelectric elements 2 provided on the diaphragm 3. When viewed from a direction perpendicular to the discharge port surface 1a, the piezoelectric elements 2 and the diaphragm 3 are positioned to overlap with the nozzles 4. The vibration of the piezoelectric elements 2 is transmitted through the diaphragm 3 to the liquid inside the foaming chamber 8 (pressure generating chamber), pressurizing the liquid and causing it to be discharged from the discharge port.

[0017] As described above, the nozzle 4a outlet surface 1a of the substrate 1 is treated with a liquid-repellent coating. By making the area around the nozzle 4a an ink-repellent region 5, the adhesion of scattered liquid droplets to the vicinity of the nozzle can be suppressed, and a decrease in ejection performance can be prevented. However, the entire nozzle surface 1a does not necessarily need to be an ink-repellent region 5; areas where the effect of liquid droplet adhesion on ejection performance is negligible may not be treated with a liquid-repellent coating and may be designated as non-ink-repellent regions 6.

[0018] Furthermore, the protruding surface 1b of the convex portion 1c that protrudes in the stacking direction from the discharge port surface 1a is a non-ink-repellent area 6 that has not been treated with a liquid-repellent coating. When viewed from a direction perpendicular to the discharge port surface 1a, the convex portion 1c is positioned so as not to overlap with the foaming chamber 8. By making the protruding surface 1b a non-ink-repellent area 6, a separate component such as a protective member 9 can be bonded to the substrate 1 with good adhesion using an adhesive or the like. In addition, by configuring the protruding surface 1b to be higher than the discharge port surface 1a, the height of the protective member 9 can be minimized, and a decrease in the strength of the protective member 9 can be suppressed.

[0019] The protective member 9 is a member for suppressing contact between the substrate 1 and a cleaning member, such as a wipe, used when the liquid dispensing device is restored to its discharge state. In the stacking direction, the upper surface of the protective member 9 is positioned higher than the upper surface of the substrate 1 (the nozzle 4 forming surface) and is located on the non-ink-repellent region 6 (on the non-liquid-repellent region). By providing the protective member 9, strong contact between the cleaning member and the substrate 1 can be suppressed, preventing cracking of the substrate 1.

[0020] In this embodiment, the protective member 9 is positioned such that, when viewed from a direction perpendicular to the discharge port surface 1a, the edge of the protective member 9 on the discharge port 4a side and the edge of the protrusion 1c overlap. Furthermore, the ink-repellent area 5 is formed up to the end of the protective member 9 on the discharge port 4a side, and when viewed from a direction perpendicular to the discharge port surface 1a, the boundary between the ink-repellent area 5 and the non-ink-repellent area 6 overlaps with the end of the protective member 9. Moreover, when viewed from a direction perpendicular to the discharge port surface 1a, the protrusion 1c and the protective member 9 Since the foaming chamber 8 is positioned so as not to overlap with the foaming chamber 8, the area near the discharge port 4a is designated as an ink-repellent area 5, resulting in a configuration that effectively suppresses discharge performance. Furthermore, since the protective member 9 is positioned away from the discharge port 4a, it is possible to suppress the reduction in discharge performance caused by the protective member 9, and also prevent damage to the substrate 1 when cleaning the discharge port surface 1a.

[0021] <Manufacturing method for element substrates> Next, the manufacturing method of the element substrate 100 will be described, focusing on the method for forming the ink-repellent region, which is characteristic of the present invention. The element substrate is manufactured, for example, by stacking multiple metal layers on a silicon wafer, forming ejection ports, and then separating them one by one using a dicing device or the like. In the following, the manufacturing process of the element substrate, which is characteristic of the present invention, from the formation of the ejection ports to the cutting process using a dicing device will be mainly described.

[0022] Figures 2(a) to 2(d) are schematic cross-sectional diagrams showing the manufacturing method of the element substrate 100 according to the first embodiment. In the following description, in order to distinguish between the finished product and the state during manufacturing, components that are substantially the same as those described in Figure 1 may be given different reference numerals.

[0023] The element substrate 100 has a laminated structure consisting of a channel substrate 11, an actuator substrate 12, and a nozzle substrate 13, in that order from the bottom layer. These substrates are made of, for example, silicon substrates, and predetermined channels and the like are formed by exposure and development of polyresist, followed by Si dry etching.

[0024] The flow channel substrate 11 is provided with a flow channel 41 through which liquid is supplied, a recess 42 in which a piezoelectric element 22 is placed, a recess 43 in which an electrode 24 is placed, and the like. An actuator substrate 12, which has a piezoelectric element 22 and a diaphragm 23, is formed on the flow channel substrate 11 by bonding technology using an adhesive 31 or the like. The piezoelectric element 22 is made of a sintered metal oxide crystal, for example, with a PZT (lead zirconate titanate) film applied. Furthermore, a nozzle substrate 13, on which a nozzle 45 is formed, is formed on the actuator substrate 12 by bonding technology using an adhesive 32 or the like. Figure 2(a) shows the flow channel substrate 11, actuator substrate 12, and nozzle substrate 13 stacked together, with various passages and spaces formed and processed into a desired shape. The aperture accuracy of the nozzle 45, etc., is based on the accuracy of photolithography such as exposure of polyresist, and can be formed with an accuracy of 1 μm or less.

[0025] As shown in Figure 2(a), a foaming chamber 44 is formed by the actuator substrate 12 and the nozzle substrate 13. The foaming chamber 44 communicates with the flow path 41 and the nozzle 45, and is provided to contain the ink supplied from the flow path 41 and to discharge the ink from the nozzle 45. The lower surface of the foaming chamber 44 is made up of a diaphragm 23 of the actuator substrate 12, and a piezoelectric element 22 is provided on the lower surface of the diaphragm 23 corresponding to the nozzle 45. In this way, the nozzle 45, the diaphragm 23 and the piezoelectric element 22 are positioned to overlap, and the vibration energy generated by the piezoelectric element allows the liquid to be discharged from the nozzle 45.

[0026] Furthermore, the nozzle substrate 13 has a stepped upper surface, and a protrusion 13b is provided that is positioned higher than the discharge port surface 13a where the discharge port of the nozzle 45 is formed. The protrusion 13b is positioned offset from directly above the foaming chamber 44.

[0027] After being processed into a predetermined shape, a liquid-repellent treatment process is performed in which an ink-repellent film is formed on the upper surface of the nozzle substrate 13 by vapor deposition, as shown in Figure 2(b), thereby forming an ink-repellent region 25. Fluoride is preferred as the ink-repellent film, and examples of fluoride include fluororesin materials. Note that methods other than vapor deposition may be used for film formation. In this process, the discharge surface 13a and protrusions 13b of the nozzle substrate 13 are covered with the ink-repellent film, forming the ink-repellent region 25.

[0028] Next, as shown in Figure 2(c), a liquid-repellent treatment removal process is performed in which the upper part of the protrusion 13b, along with the ink-repellent region 25, is removed by grinding or the like. In this process, the ink-repellent region 25 is removed from the upper surface of the protrusion 13b, and a non-ink-repellent region 26 is formed on the upper surface of the protrusion 13b.

[0029] As described above, since the nozzle is formed by photolithography, if the initial height of the protrusion 13b is large, the surface irregularities of the nozzle substrate 13 become large, making resist formation difficult. On the other hand, if the initial height of the protrusion 13b is too low, it becomes difficult to thin and remove the ink-repellent film. Therefore, the initial height of the protrusion 13b relative to the discharge port surface 13a shown in Figure 2(a) is preferably about 10 μm to 100 μm. Also, the post-grinding height of the protrusion 13b relative to the discharge port surface 13a shown in Figure 2(c) is preferably about 5 μm to 50 μm.

[0030] Then, as shown in Figure 2(d), a bonding process is performed in which the protective member 15 is bonded to the protrusion 13b of the nozzle substrate 13. Since the upper surface of the protrusion 13b has had the ink-repellent film removed and is now a non-ink-repellent area 26, the protective member 15 can be bonded using adhesive 35. After the bonding process of the protective member 15, the element substrate is completed through a cutting process using a dicing device.

[0031] If the nozzle substrate 13 is thin (for example, about 1 μm to 50 μm), the nozzle plate may crack due to excessive contact with the nozzle during the wiping operation of the discharge recovery. Therefore, a protective member 15 is provided to minimize contact between the cleaning member and the nozzle substrate 13. Considering mechanical strength, metal is preferable for the protective member 15, such as SUS, aluminum alloy, or nickel alloy, but silicon may also be used. Note that if protrusions such as the convex portion 13b or the protective member 15 are provided near the nozzle 45, it may adversely affect the discharge performance, so it is desirable to provide the protective member 15 at a position appropriately away from the nozzle 45. Specifically, the convex portion 13b and the protective member 15 should be provided at a distance from the nozzle 45 such that they do not overlap with the foaming chamber 44 when viewed from a direction perpendicular to the discharge opening surface 13a.

[0032] As described above, according to this embodiment, since the ink-repellent film in the ink-repellent region near the nozzle is formed by vapor deposition, stable liquid-repellent performance can be obtained and a decrease in ejection performance can be prevented. Furthermore, since a protective member for protecting the nozzle plate can be provided in a non-ink-repellent region at a position away from the nozzle, the strength against nozzle recovery operations and the like can be improved and nozzle damage can be prevented. Therefore, it is possible to manufacture an element substrate with stable ejection performance.

[0033] Furthermore, according to this embodiment, as shown in Figure 3(c), the ink-repellent region 25 is also formed on the vertical wall on the discharge port surface 13a side of the protrusion 13b. Therefore, it is possible to lower the surface energy not only of the nozzle surface but also of the vertical wall, making it possible to discharge ink smoothly without droplets remaining at the corners of the boundary between the nozzle surface and the vertical wall.

[0034] (Second embodiment) Next, as a second embodiment, a configuration in which a hard mask substrate that has been pre-processed to a predetermined shape is provided in addition to the first embodiment will be described. In the following, the characteristic parts of the second embodiment will be described in detail, and components similar to those in the first embodiment will be denoted by the same reference numerals and their description will be omitted.

[0035] The schematic configuration of the element substrate according to the second embodiment is the same as that of the first embodiment shown in Figure 1. That is, the upper surface of the substrate 1 is formed in a stepped shape, and the substrate 1 has an ejection port surface 1a which is an ink-repellent region 5 and a protruding surface 1b which is a non-ink-repellent region 6 formed higher than the ejection port surface 1a. Furthermore, the substrate 1 of this embodiment is configured to include a hard mask substrate 14, which will be described later, in addition to the flow channel substrate 11, actuator substrate 12, and nozzle substrate 13.

[0036] Figures 3(a) to 3(f) are schematic cross-sectional views showing a method for manufacturing an element substrate according to the second embodiment. In this embodiment, as shown in Figure 3(a), the flow channel substrate 11, actuator substrate 12, and nozzle substrate 13 are processed into predetermined shapes by photolithography before bonding the hard mask substrate 14.

[0037] The hard mask substrate 14 is pre-processed before bonding, and a first processed portion 46 is formed on its lower surface. The lower surface of the hard mask substrate 14 is formed in a stepped shape by the first processed portion 46, and the hard mask substrate 14 has an opposing portion 14a that faces the nozzle 45 and a bonding portion 14b that protrudes toward the substrate and is bonded to the nozzle substrate 13. When the hard mask substrate 14 is bonded to the nozzle substrate 13, the first processed portion 46 becomes the opposing space between the discharge port surface 13a of the nozzle substrate and the opposing portion 14a, contributing to the shortening of the grinding process. The hard mask substrate 14 is preferably one with a total substrate thickness of 400 μm to 725 μm, and the first processed portion 46 with a height of 100 μm to 200 μm is formed on its lower surface.

[0038] After being processed into a predetermined shape, a mask bonding process is performed in which the hard mask substrate 14 is bonded to the nozzle substrate 13 with adhesive 33, as shown in Figure 3(b). When the bonding portion 14b of the hard mask substrate 14 is bonded to the nozzle substrate 13, the first processing portion 46 is positioned directly above the foaming chamber 44 between the nozzle substrate 13 and the hard mask substrate 14. In other words, after the bonding process of the hard mask substrate 14, a space is formed near the top of the nozzle 45. Also, when viewed from a direction perpendicular to the discharge port surface 13a, the bonding portion 14b is positioned so as not to overlap with the foaming chamber 44. With this arrangement, the boundary between the ink-repellent region and the non-ink-repellent region formed in a later process is positioned away from the nozzle 45.

[0039] Next, as shown in Figure 3(c), a grinding process is performed as a mask removal process in which the upper part of the hard mask substrate 14, along with the ink-repellent area 25, is removed by grinding, and the area above the nozzle 45 on the nozzle substrate 13 is opened. At this time, since the first processed part 46 of the hard mask substrate 14 has been processed in advance, the time-consuming grinding process can be shortened.

[0040] Next, as shown in Figure 3(d), a liquid-repellent treatment process is performed in which an ink-repellent film is formed on the upper surfaces of the nozzle substrate 13 and the hard mask substrate 14 by vapor deposition, forming an ink-repellent region 25. Next, as shown in Figure 3(e), a grinding process is performed again as a liquid-repellent region removal process in which the upper part of the hard mask substrate 14 is ground off together with the ink-repellent region 25, exposing the non-ink-repellent region 26 on the hard mask substrate 14 (on the hard mask). At this time, the opposing portion 14a is completely removed, and only a part of the bonding portion 14b remains on the nozzle substrate 13. In this embodiment, the height of the hard mask substrate 14 relative to the discharge port surface 13a after grinding is preferably about 5 μm to 50 μm. Next, as shown in Figure 3(f), a bonding process is performed in which a protective member 15 is bonded to the non-ink-repellent region 26 of the hard mask substrate 14.

[0041] According to this embodiment, when forming nozzles or the like on a substrate by photolithography, since no protrusions are provided on the surface of the substrate, stable formation is possible and the dimensional accuracy of the nozzles or the like is improved. Furthermore, the positional accuracy of the boundary between the ink-repellent and non-ink-repellent areas depends on the placement accuracy of the hard mask substrate when joining the hard mask substrate, so the deviation from the design value can be kept to about 10 μm or less.

[0042] Based on the above, according to this embodiment, by vapor deposition, the area near the nozzle can be made an ink-repellent region, and a position away from the nozzle can be made a non-ink-repellent region, and a protective member for protecting the nozzle plate can be provided. Therefore, it is possible to stabilize the liquid-repellent properties, prevent nozzle damage, and manufacture an element substrate with stable ejection performance.

[0043] (Third embodiment) Next, as a third embodiment, a configuration in which the discharge surface where the discharge port is formed and the adhesive surface to which the protective member is bonded are the same surface will be described. In the following, the characteristic parts of the third embodiment will be described in detail, and components similar to those of the first embodiment will be denoted by the same reference numerals and their description will be omitted.

[0044] Figure 4 is a schematic diagram of the element substrate 300 according to the third embodiment. The element substrate 300 has piezoelectric elements 2 and a diaphragm 3 arranged on a substrate 10, and a flow path 7, a foaming chamber 8, and a nozzle 4 are formed in communication with each other. Multiple nozzle 4a are formed on the discharge port surface 10a of the substrate 10, and a protective member 9 that protrudes from the discharge port surface 10a is provided on the discharge port surface 10a. In other words, the third embodiment differs from the first embodiment in that the surface on which the discharge ports 4a are formed on the substrate 10 and the surface on which the protective member 9 is provided are the same surface.

[0045] In this embodiment as well, the protective member 9 is positioned so as not to overlap with the foaming chamber 8 when viewed from the direction of protrusion of the protective member 9 (the stacking direction of the substrate 10). In other words, this configuration suppresses a decrease in discharge performance due to the protective member 9.

[0046] Of the discharge port surface 10a, the area near the discharge port 4a is an ink-repellent region 5 that has been treated to repel liquid, and the area where the protective member 9 is provided is an ink-repellent region 6. The ink-repellent region 5 is formed up to the end of the protective member 9 on the discharge port 4a side, and the boundary between the ink-repellent region 5 and the ink-repellent region 6 overlaps with the end of the protective member 9.

[0047] Next, the method for manufacturing the element substrate 300 will be explained, focusing on the method for forming the ink-repellent region, which is characteristic of the present invention. Figures 5(a) to 5(g) are schematic cross-sectional views showing the method for manufacturing the element substrate 300 according to the third embodiment. In this embodiment, as shown in Figure 5(a), the flow channel substrate 11, actuator substrate 12, and nozzle substrate 13 are processed into predetermined shapes by photolithography before bonding the hard mask substrate 14.

[0048] In this embodiment, the hard mask substrate 14 is pre-processed before bonding, and a first processed portion 46 and a second processed portion 47 are formed on the lower surface. The lower surface of the hard mask substrate 14 is formed in a stepped shape by the first processed portion 46, and the hard mask substrate 14 has an opposing portion 14a that faces the nozzle 45 and a bonding portion 14b that is bonded to the nozzle substrate 13. As the hard mask substrate 14, for example, one with a total thickness of 400 to 725 μm is preferred, and the depth of the first processed portion 46 is preferably 100 μm to 200 μm. The first processed portion 46 is a part processed after the hard mask substrate 14 has been bonded to the nozzle substrate 13 in order to shorten the grinding process, and is formed to create an opposing space between the opposing portion 14a of the hard mask substrate 14 and the discharge port surface 13a of the nozzle substrate 13.

[0049] The second processing section 47 is formed in a groove shape in the joint 14b of the hard mask substrate 14 and is pre-processed to facilitate the subsequent hard mask substrate removal process. The second processing section 47 is the part into which the stripping solution is poured during the hard mask substrate removal process, and a depth of 50 μm to 100 μm is preferable in order to open the upper surface of the second processing section 47 after the grinding process. Multiple second processing sections 47 are formed on the lower surface of the hard mask substrate 14 to increase the contact area between the stripping solution and the hard mask substrate 14 when the stripping solution is poured in. In other words, the hard mask substrate 14 in this embodiment is exposed to chemical substances and removed during the manufacturing process of the element substrate 300. The bonding material 36 that bonds the hard mask substrate 14 to the nozzle substrate 13 is removed at the same time as the hard mask substrate 14. Therefore, it is preferable to use a material that is easily dissolved by chemical substances such as a resist rather than an adhesive for the bonding material 36.

[0050] After being processed into a predetermined shape, a mask bonding process is performed in which the hard mask substrate 14 is bonded onto the nozzle substrate 13 by bonding material 36, as shown in Figure 5(b). When the plate 14 is bonded to the nozzle substrate 13, the first processing section 46 is positioned directly above the foaming chamber 44 between the nozzle substrate 13 and the hard mask substrate 14. In other words, after the bonding process of the hard mask substrate 14, a space is formed near the top of the nozzle 45.

[0051] Next, as shown in Figure 5(c), a grinding process is performed as a mask removal process in which the upper part of the hard mask substrate 14, along with the ink-repellent area 25, is removed by grinding, and the area above the nozzle 45 on the nozzle substrate 13 is opened. At this time, since the first processed part 46 of the hard mask substrate 14 has been processed in advance, the time-consuming grinding process can be shortened.

[0052] Next, as shown in Figure 5(d), a liquid-repellent treatment process is performed in which an ink-repellent film is formed on the upper surfaces of the nozzle substrate 13 and the hard mask substrate 14 by vapor deposition, thereby forming an ink-repellent region 25. Next, as shown in Figure 5(e), in a liquid-repellent region removal process, the upper part of the hard mask substrate 14 is ground down along with the ink-repellent region 25, and a second processing section 47 opens on the upper surface of the hard mask substrate 14. In this embodiment, the height of the hard mask substrate 14 relative to the discharge port surface 13a after grinding is preferably about 5 μm to 50 μm.

[0053] Figure 6(a) is a top view of Figure 5(e), showing the shape of the second processing section 47. The second processing section is formed by machining multiple grooves with a square cross-section to increase the contact area with the stripping solution in the dissolution process described later. Figure 6(b) shows a modified example of the second processing section 47, where the cross-sectional shape of the grooves is rectangular. The second processing section is not limited to the above configuration; the cross-sectional shape and depth can be freely selected as long as the removal of the hard mask substrate can be facilitated.

[0054] After the grinding process, a mask removal process is performed in which a stripping solution is poured into the opening of the second processing section 47, dissolving and removing the hard mask substrate 14, and a non-ink-repellent area 26 is formed on the nozzle substrate 13. Figure 5(f) shows the state in which the hard mask substrate 14 has been removed from the nozzle substrate 13, and the area where the hard mask substrate 14 was originally provided is exposed as a non-ink-repellent area 6. As the stripping solution, a resist stripping solution soluble in resist can be used. Subsequently, as shown in Figure 5(g), a bonding process is performed in which a protective member 15 is bonded to the non-ink-repellent area 26 of the nozzle substrate 13.

[0055] As described above, according to this embodiment, by vapor deposition, the area near the nozzle can be made an ink-repellent region, and a position away from the nozzle can be made a non-ink-repellent region, and a protective member for protecting the nozzle plate can be provided.Therefore, it is possible to stabilize the liquid-repellent properties, prevent nozzle damage, and manufacture an element substrate with stable ejection performance.Also, similar to the second embodiment, since nozzles and the like can be formed by photolithography on a substrate surface without irregularities, the dimensional accuracy of nozzles and the like is improved compared to the first embodiment.

[0056] Furthermore, according to this embodiment, since no protrusions are provided, it is easy to reduce the distance between the recording medium and the nozzle 45. Whether to provide protrusions on the substrate as in the first embodiment, etc., or to form the substrate in a flat shape as in this embodiment, can be appropriately selected considering the desired ejection performance, manufacturing difficulty, etc.

[0057] (Fourth embodiment) Next, as a fourth embodiment, a configuration in which the shape of the processed portion of the hard mask substrate is changed from that of the third embodiment will be described. In the following, the characteristic parts of the fourth embodiment will be described in detail, and components similar to those of the third embodiment will be denoted by the same reference numerals and their description will be omitted.

[0058] The schematic configuration of the element substrate according to the fourth embodiment is the same as that of the third embodiment shown in Figure 4. That is, the surface on which the ejection port 4a of the substrate 10 is formed and the surface on which the protective member 9 is provided are the same surface, and an ink-repellent region 5 and an ink-non-ink-repellent region 6 are formed on the ejection port surface 10a.

[0059] In the third embodiment, as shown in Figure 5(g), the end of the ink-repellent region 25 on the protective member 9 side is formed to be raised compared to other parts. While this fence-like formation of the ink-repellent film prevents droplets from remaining in the corners, as explained in the first embodiment, depending on the configuration of the element substrate, the raised portion may be unnecessary and become waste. Therefore, in the fourth embodiment, the manufacturing method was modified so that no ink-repellent film remains in that portion.

[0060] Figures 7(a) to 7(g) are schematic cross-sectional views showing a method for manufacturing an element substrate according to the fourth embodiment. In this embodiment, as shown in Figure 7(a), a hard mask substrate 14 is bonded to a flow channel substrate 11, an actuator substrate 12, and a nozzle substrate 13 that have been processed into a predetermined shape by photolithography.

[0061] The hard mask substrate 14 in this embodiment is pre-processed before bonding, and a first processing portion 46 and a second processing portion 47 are formed on the lower surface. The lower surface of the hard mask substrate 14 is formed in a stepped shape by the first processing portion 46, and the hard mask substrate 14 has a facing portion 14a that faces the nozzle 45 and a bonding portion 14b that is bonded to the nozzle substrate 13. As the hard mask substrate 14, for example, one with a total thickness of 400 to 725 μm is preferred. The first processing portion 46 is provided to shorten the grinding process, and the depth of the first processing portion 46 is preferably 100 μm to 200 μm. The second processing portion 47 is formed on the bonding portion 14b for removal of the hard mask substrate 14, and the depth of the second processing portion 47 is preferably 50 μm to 100 μm.

[0062] The second processed portion 47 of this embodiment differs from the third embodiment in that the edge of the joint portion 14b on the side of the first processed portion 46 (opposing portion side) is also processed. By pre-processing the edge portion adjacent to the first processed portion 46 on the lower surface side of the hard mask substrate 14, it is possible to prevent the ink-repellent film from remaining in a fence-like manner.

[0063] In this embodiment, the bonding process of the hard mask substrate 14 shown in Figure 7(b) and the grinding process of the upper part of the hard mask substrate 14 shown in Figure 7(c) are the same as in the third embodiment. After the grinding process, because the second processing section 47 has the above-described configuration, an overhang portion 48 remains at the end of the hard mask substrate 14 on the nozzle 45 side, protruding from the upper part of the hard mask substrate 14 towards the nozzle 45 side after grinding.

[0064] Subsequently, as shown in Figure 7(d), a liquid-repellent treatment process is performed in which an ink-repellent film is formed on the nozzle substrate 13 and the hard mask substrate 14 by vapor deposition. However, in this embodiment, the ink-repellent region 25 is formed by the eaves 48 in a different manner than in the third embodiment. Of the portion of the discharge port surface 13a of the nozzle substrate 13 that is covered by the eaves 48, the ink-repellent film wraps around to the end on the nozzle 45 side, forming the ink-repellent region 25. On the other hand, the ink-repellent film does not wrap around to the vicinity of the boundary between the nozzle substrate 13 and the hard mask substrate 14, so the ink-repellent region 25 is not formed there. Therefore, in this embodiment, the ink-repellent region 25 is divided at the boundary between the nozzle substrate 13 and the hard mask substrate 14. By using this manufacturing method, the ink-repellent film is not formed along the vertical wall portion of the hard mask substrate 14, thus preventing the ink-repellent film from forming and remaining in a fence-like manner.

[0065] To prevent the ink-repellent film from spreading to the boundary between the nozzle substrate 13 and the hard mask substrate 14, it is preferable that the length of the eaves portion 48 (the length of the projection from the end) be 50 μm or more. Furthermore, the deeper the second processing portion 47, the shorter the grinding process required to remove the hard mask substrate 14, while at the same time, the easier it is for the ink-repellent film to spread to the underside of the eaves portion 48. Therefore, the depth of the second processing portion 47 and the length of the eaves portion 48 should be determined considering factors such as the efficiency of the grinding process and the ease with which the ink-repellent film spreads.

[0066] After the ink-repellent film formation process, as shown in Figure 7(e), a grinding process is performed as a mask removal process in which the upper part of the hard mask substrate 14, along with the ink-repellent region 25, is ground away, and a second processing section 47 opens on the upper surface of the hard mask substrate 14. Subsequently, a stripping solution is poured into the opening of the second processing section 47, and the hard mask substrate 14 is removed by dissolution, exposing the non-ink-repellent region 26 on the nozzle substrate 13. Figure 7(f) shows the state after the mask removal process has been performed, the hard mask substrate 14 has been removed from the nozzle substrate 13, and the area where the hard mask substrate 14 was originally provided is exposed as a non-ink-repellent region 6. At this time, the thickness of the ink-repellent film is formed to be approximately constant throughout the entire ink-repellent region 25. Subsequently, as shown in Figure 7(g), a bonding process is performed in which a protective member 15 is bonded to the non-ink-repellent region 26 of the nozzle substrate 13.

[0067] As described above, according to this embodiment, by vapor deposition, the area near the nozzle can be made an ink-repellent region, and the area away from the nozzle can be made a non-ink-repellent region, and a protective member for protecting the nozzle plate can be provided.Therefore, it is possible to stabilize the liquid-repellent properties, prevent nozzle damage, and manufacture an element substrate with stable ejection performance.Also, similar to the third embodiment, it is possible to prevent the ink-repellent film from remaining in a fence-like manner.

[0068] (Fifth embodiment) Next, as a fifth embodiment, a configuration in which the shape of the processed portion of the hard mask substrate is changed compared to the third and fourth embodiments will be described. In the following, the characteristic parts of the fifth embodiment will be described in detail, and components similar to those in the third embodiment will be denoted by the same reference numerals and their description will be omitted.

[0069] The schematic configuration of the element substrate according to the fifth embodiment is the same as that of the third embodiment shown in Figure 4. That is, the surface on which the ejection port 4a of the substrate 10 is formed and the surface on which the protective member 9 is provided are the same surface, and an ink-repellent region 5 and a non-ink-repellent region 6 are formed on the ejection port surface 10a.

[0070] In the third embodiment, the method for manufacturing the element substrate included a step of pouring in a stripping solution as a step of removing the hard mask substrate 14. On the other hand, in this embodiment, the manufacturing method was modified so that the hard mask substrate removal step is combined with a cutting step in which the silicon wafer is cut with a dicing device or the like to obtain individual element substrates.

[0071] Figures 8(a) to 8(g) are schematic cross-sectional views showing a method for manufacturing an element substrate according to the fifth embodiment. In this embodiment, as shown in Figure 8(a), a hard mask substrate 14 is bonded to a flow channel substrate 11, an actuator substrate 12, and a nozzle substrate 13 that have been processed into a predetermined shape by photolithography.

[0072] The hard mask substrate 14 in this embodiment is pre-processed before bonding, and a first processed portion 46 and a second processed portion 47 are formed on the lower surface. The lower surface of the hard mask substrate 14 is formed in a stepped shape by the first processed portion 46 and the second processed portion 47. The hard mask substrate 14 has a facing portion 14a that faces the nozzle 45, a bonding portion 14b that is bonded to the nozzle substrate 13, and an intermediate portion 14c located between the facing portion 14a and the bonding portion 14b. As the hard mask substrate 14, for example, one with a total thickness of 400 to 725 μm is preferred. The first processed portion 46 is provided to shorten the grinding process, and the depth of the first processed portion 46 is preferably 100 μm to 200 μm.

[0073] As described above, the second processing section 47 of this embodiment is processed in the same way as the first processing section 46 so that the lower surface of the hard mask substrate 14 is formed in a stepped shape. The depth of the second processing section 47 is preferably 50 μm to 100 μm, and is formed shallower than the first processing section 46. That is, the intermediate section 14c is closer to the discharge port surface 13a than the opposing section 14a in the direction perpendicular to the discharge port surface 13a. It is located further from the discharge port surface 13a than the joint portion 14b.

[0074] In this embodiment, the bonding process of the hard mask substrate 14 shown in Figure 8(b) and the grinding process of the upper part of the hard mask substrate 14 shown in Figure 8(c) are the same as in the third embodiment. After the grinding process, because the second processing section 47 has the above-described configuration, an overhang portion 48 is formed at the nozzle 45 side end of the hard mask substrate 14, protruding from the upper part of the ground hard mask substrate 14 toward the nozzle 45. Furthermore, the overhang length of the overhang portion 48 in this embodiment is formed to be longer compared to the fourth embodiment.

[0075] Subsequently, as shown in Figure 8(d), an ink-repellent film is formed on the nozzle substrate 13 and the hard mask substrate 14 by vapor deposition. In this embodiment as well, the ink-repellent region 25 is not formed near the boundary between the nozzle substrate 13 and the hard mask substrate 14, and the ink-repellent region 25 is divided at the boundary between the nozzle substrate 13 and the hard mask substrate 14. In this embodiment, compared to the fourth embodiment, the eave length of the eaves portion 48 is larger, so the area where the ink-repellent region 25 is not formed is larger. By using this manufacturing method, the ink-repellent film is not formed along the vertical wall portion of the hard mask substrate 14, so it is possible to prevent the ink-repellent film from forming and remaining in a fence-like manner. The depth of the second processing portion 47 and the eave length of the eaves portion 48 should be determined considering the efficiency of the grinding process and the wrap-around properties of the ink-repellent film.

[0076] After the ink-repellent film formation process, as shown in Figure 8(e), a grinding process is performed as a mask portion removal process in which the upper part of the hard mask substrate 14, along with the ink-repellent region 25, is ground away, and a non-ink-repellent region 26 is formed on the upper surface of the hard mask substrate 14. After the grinding process, the remaining part that was the base of the eaves portion 48 of the hard mask substrate 14 is located only in the portion that will be cut by the dicing device in the subsequent cutting process. Therefore, as shown in Figure 8(f), when the cutting process is performed, the multiple element substrates formed on the silicon wafer are separated individually by the dicing device, and the hard mask substrate 14 is removed from the element substrates. Then, as shown in Figure 8(g), a bonding process is performed in which the protective member 15 is bonded to the nozzle substrate 13 from which the hard mask substrate 14 has been removed.

[0077] As described above, according to this embodiment, by vapor deposition, the area near the nozzle can be made an ink-repellent region, and the area away from the nozzle can be made a non-ink-repellent region, and a protective member for protecting the nozzle plate can be provided.Therefore, it is possible to stabilize the liquid-repellent properties, prevent nozzle damage, and manufacture an element substrate with stable discharge performance.In addition, it is not necessary to perform a hard mask substrate removal step between the grinding step and the cutting step, in which a stripping solution or the like is poured in to remove the hard mask substrate 14, which leads to a shortening of the process.

[0078] Although embodiments of the present invention have been described illustratively above, the present invention is not limited to the embodiments described above. For example, various modifications are possible, such as manufacturing an element substrate by bonding a hard mask substrate having a first processed portion and a second processed portion to a substrate having a protrusion. [Explanation of Symbols]

[0079] 1…Substrate, 2, 22…Generating element, 4, 45…Nozzle, 4a…Discharge port, 5, 25…Liquid-repellent region, 8, 42…Foaming chamber (pressure generating chamber), 100…Element substrate

Claims

1. A method for manufacturing an element substrate used in a liquid discharge head that discharges liquid onto a recording medium, A substrate having a nozzle including an outlet facing the recording medium, and a pressure generating chamber communicating with the nozzle, wherein a portion of the outlet surface on which the outlet is formed is treated with a liquid-repellent coating, A generating element that generates energy to discharge the liquid in the pressure generating chamber from the discharge port, In a method for manufacturing an element substrate, A liquid-repellent treatment step is performed on the substrate, A liquid-repellent region removal step, which removes a portion of the liquid-repellent region that has been treated with the liquid-repellent treatment, such that a non-liqui-repellent region that has not been treated with the liquid-repellent treatment is exposed on the surface of the substrate facing the recording medium, Includes, The substrate has a protrusion that extends from the ejection port surface toward the recording medium side, and the protrusion has a height of 10 μm or more from the ejection port surface. The method for manufacturing an element substrate is characterized in that the liquid-repellent region removal step involves removing the upper part of the protrusion that has been treated with the liquid-repellent process by grinding.

2. The method for manufacturing an element substrate according to claim 1, further comprising a bonding step of bonding a protective member to the non-liquid-repellent region after the liquid-repellent region removal step.

3. A method for manufacturing an element substrate used in a liquid discharge head that discharges liquid onto a recording medium, A substrate having a nozzle including an outlet facing the recording medium, and a pressure generating chamber communicating with the nozzle, wherein a portion of the outlet surface on which the outlet is formed is treated with a liquid-repellent coating, A generating element that generates energy to discharge the liquid in the pressure generating chamber from the discharge port, In a method for manufacturing an element substrate, A mask bonding step in which a hard mask is bonded to the ejection port surface of the substrate, A mask portion removal step, which removes the portion of the hard mask facing the nozzle, A liquid-repellent treatment step is performed on the substrate, A liquid-repellent region removal step, which removes a portion of the liquid-repellent region that has been treated with the liquid-repellent treatment, such that a non-liqui-repellent region that has not been treated with the liquid-repellent treatment is exposed on the surface of the substrate facing the recording medium, A method for manufacturing an element substrate, characterized by including the following:

4. The hard mask has a facing portion that faces the pressure generating chamber, and a joining portion that protrudes toward the substrate side relative to the facing portion and is joined to the substrate, The method for manufacturing an element substrate according to claim 3, characterized in that the joint portion is provided in a position that does not overlap with the pressure generating chamber when viewed from a direction perpendicular to the discharge port surface.

5. The method for manufacturing an element substrate according to claim 4, characterized in that the liquid-repellent region removal step involves grinding and removing the liquid-repellent region and a part of the hard mask.

6. The method for manufacturing an element substrate according to claim 5, further comprising a bonding step of bonding a protective member to a non-liquid-repellent region formed on the hard mask by the liquid-repellent region removal step, after the liquid-repellent region removal step.

7. The method for manufacturing an element substrate according to claim 4 or 5, characterized in that it includes a mask removal step of dissolving and removing the bonding material that bonds the hard mask and the substrate after the liquid-repellent region removal step.

8. The method for manufacturing an element substrate according to claim 7, further comprising a bonding step of bonding a protective member to a non-liqui-repellent region formed on the substrate by the mask removal step, after the mask removal step.

9. The method for manufacturing an element substrate according to claim 7 or 8, characterized in that the hard mask has grooves formed therein that extend in a direction perpendicular to the discharge port surface.

10. The method for manufacturing an element substrate according to claim 9, characterized in that the groove is formed on the edge of the joint on the opposing side.

11. The hard mask further has an intermediate portion located between the opposing portion and the joining portion, The method for manufacturing an element substrate according to claim 7 or 8, characterized in that the intermediate portion is located closer to the discharge port surface than the opposing portion and further from the discharge port surface than the joint portion in a direction perpendicular to the discharge port surface.

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