Nozzle plate, inkjet head, method for manufacturing nozzle plate, and method for manufacturing inkjet head

Abstract

When manufacturing the nozzle plate 10, a groove 15 is pre-processed in the part where the substrate is shaped to form a depth of 5μm or more and 10μm or less. When the shape is shaped along the groove 15 by laser processing, the groove 15 becomes a step 151. Adhesive residue 152 is attached to the step 151. In addition, the adhesive residue 152 is smaller than the step 151, so it will not cause poor adhesion or voids when the nozzle plate 10 is bonded to the flow path, etc.

Description

Technical Field

[0001] This invention relates to a nozzle plate, an inkjet head, a method for manufacturing a nozzle plate, and a method for manufacturing an inkjet head. Background Technology

[0002] In an inkjet head that ejects ink, a flow path substrate is bonded to a nozzle plate, which serves as a substrate on which nozzles are formed, using an adhesive, and ink is ejected from the nozzles. As a method for forming nozzles in a substrate, a method is known as follows: a tool is pressed into the substrate and stretched so that the recess reaches the back side of the substrate, and then the protrusion on the back side of the substrate is ground, thereby transferring the shape of the tool through the substrate (see, for example, Patent Document 1).

[0003] As the substrate for such a nozzle plate, metals such as SUS (Steel Use Stainless) are used, based on the viewpoints of chemical stability of ink and durability against mechanical friction. As a method for processing the shape of the nozzle plate from the metal plate on which the nozzle is formed, wet etching based on etching solution (see Patent Document 2) and laser etching based on laser equipment (see Patent Document 3) are known, for example.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 3755332

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-217706

[0008] Patent Document 3: Japanese Patent Application Publication No. 2007-307842 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, when the shape is processed by wet etching, the resist mask enters the nozzle, and even if the resist is stripped after the shape is processed, resist residue may remain in the nozzle.

[0011] Furthermore, when machining shapes using laser etching, poor adhesion or voids may occur near the laser-processed area due to protrusions caused by dross. While using short-pulse lasers such as picosecond or femtosecond lasers can suppress dross formation, these devices are more expensive than commonly used nanosecond pulse lasers, resulting in poor economic viability.

[0012] Additionally, when bonding the flow path substrate to the nozzle plate, poor adhesion may occur due to adhesive being exposed on the side.

[0013] The present invention was made in view of the above circumstances, and its object is to provide a nozzle plate, an inkjet head, a method for manufacturing a nozzle plate, and a method for manufacturing an inkjet head that can suppress the generation of poor adhesion or voids during bonding.

[0014] Methods for solving problems

[0015] To address the aforementioned issues, the invention described in technical solution 1 provides a nozzle plate, which is a nozzle plate for an inkjet head, wherein the nozzle plate comprises:

[0016] The first surface is bonded to the upper substrate using an adhesive; and

[0017] The second side has an opening for the ink-dispensing nozzle.

[0018] The first surface has a stepped portion formed at its edge.

[0019] The invention described in technical solution 2 is based on the nozzle plate described in technical solution 1.

[0020] There is residue adhering to the stepped portion.

[0021] The invention described in technical solution 3 is based on the nozzle plate described in technical solution 1 or 2.

[0022] The substrate forming the nozzle plate is silicon or metal.

[0023] The invention described in technical solution 4 is based on the nozzle plate described in any one of technical solutions 1 to 3.

[0024] The stepped portion has a depth of more than 5 μm and less than 10 μm in the center direction of the nozzle plate.

[0025] The invention described in technical solution 5 provides an inkjet head,

[0026] A nozzle plate having any one of the technical solutions 1 to 4.

[0027] The invention described in technical solution 6 provides a method for manufacturing a nozzle plate, which is the method for manufacturing a nozzle plate according to any one of technical solutions 1 to 4, comprising:

[0028] The groove processing step forms a recess on the first surface in a manner that shapes multiple nozzle plates for a single substrate.

[0029] The nozzle forming process forms a nozzle such that an opening is formed on the second surface of the substrate; and

[0030] In the shape processing step, the nozzle plate is cut out from the substrate by cutting off the recess through laser processing.

[0031] The invention described in technical solution 7 is based on the method for manufacturing the nozzle plate described in technical solution 6.

[0032] The recess is formed by wet etching.

[0033] The invention described in technical solution 8, in the method of manufacturing the nozzle plate described in technical solution 6 or 7,

[0034] It has a waterproof membrane forming process that forms a waterproof membrane on the second surface.

[0035] The invention described in technical solution 9 provides a method for manufacturing an inkjet head, comprising:

[0036] The nozzle plate manufacturing process includes manufacturing the nozzle plate as described in any one of technical solutions 1 to 4; and

[0037] In the bonding process, the first surface of the nozzle plate and the upper substrate are bonded together using an adhesive.

[0038] The effects of the invention

[0039] The nozzle plate, the inkjet head having the nozzle plate, the method for manufacturing the nozzle plate, and the method for manufacturing the inkjet head according to the present invention can suppress poor adhesion or voids during bonding. Attached Figure Description

[0040] Figure 1A This is an overall view of the inkjet head involved in this embodiment.

[0041] Figure 1B yes Figure 1A A cross-sectional view at the IB-IB line.

[0042] Figure 2 This is an enlarged cross-sectional view of the nozzle plate involved in this embodiment.

[0043] Figure 3 This is a flowchart illustrating a method for manufacturing a nozzle plate according to this embodiment.

[0044] Figure 4A This is a top view and a cross-sectional view along line AB, showing the manufacturing method of the nozzle plate according to this embodiment.

[0045] Figure 4B This is a top view and a cross-sectional view along line AB, showing the manufacturing method of the nozzle plate according to this embodiment.

[0046] Figure 4C This is a top view and a cross-sectional view along line AB, showing the manufacturing method of the nozzle plate according to this embodiment.

[0047] Figure 4DThis is a top view and a cross-sectional view along line AB, showing the manufacturing method of the nozzle plate according to this embodiment. Detailed Implementation

[0048] Hereinafter, embodiments relating to the nozzle plate, the inkjet head having the nozzle plate, the method of manufacturing the nozzle plate, and the method of manufacturing the inkjet head of the present invention will be described with reference to the accompanying drawings.

[0049] Figure 1A This is an overall view of the inkjet head 1 involved in this embodiment. Figure 1B Viewed from the side (-X direction side). Figure 1A A cross-sectional view of the inkjet head 1 at the IB-IB line. Figure 1B The image shows a cross-section of the inkjet head 1 at the face of the four nozzles 14 comprising four nozzle rows.

[0050] The inkjet head 1 includes a head chip 2, a common ink chamber 70, a support substrate 80, wiring components 3, and a drive unit 4.

[0051] The head chip 2 is a structure for ejecting ink from the nozzles 14, and multiple (in this case, four) plate-shaped substrates are stacked together. The bottommost substrate in the head chip 2 is the nozzle plate 10. Multiple nozzles 14 are formed on the nozzle plate 10, which can eject ink approximately perpendicularly to the ink ejection surface (the exposed surface of the nozzle plate 10) where the opening of the nozzle 14 is provided. On the side of the nozzle plate 10 opposite to the ink ejection surface, a pressure chamber substrate 20, a spacer substrate 40, and a wiring substrate 50 are sequentially and sequentially bonded together upward (in the +Z direction) using an adhesive or the like. Hereinafter, each of these substrates, such as the nozzle plate 10, the pressure chamber substrate 20, the spacer substrate 40, and the wiring substrate 50, will be referred to individually or collectively as flow path substrates 10, 20, 40, 50, etc.

[0052] In these flow path substrates 10, 20, 40, and 50, an ink flow path communicating with the nozzle 14 is provided, and an opening is formed in the exposed side (+Z direction side) of the wiring substrate 50. A common ink chamber 70 is provided on the exposed surface of the wiring substrate 50 in such a way that it covers all the openings. The common ink chamber 70 has an ink supply section 70a for supplying ink to the ink chamber forming member 70c and an ink discharge section 70b for discharging ink from the ink chamber forming member 70c in its upper part. The ink stored in the ink chamber forming member 70c of the common ink chamber 70 is supplied to each nozzle 14 from the opening of the wiring substrate 50.

[0053] A pressure chamber 21 is provided along the ink flow path. The pressure chamber 21 is provided to penetrate the pressure chamber substrate 20 in the vertical direction (Z direction), and the upper surface of the pressure chamber 21 is formed by a vibrating plate 30 disposed between the pressure chamber substrate 20 and the spacer substrate 40. Due to the displacement (deformation) of the piezoelectric element 60 in the storage section 41 which is disposed adjacent to the pressure chamber 21 via the vibrating plate 30, the vibrating plate 30 (pressure chamber 21) deforms, thereby imparting a pressure change to the ink in the pressure chamber 21. By imparting an appropriate pressure change to the ink in the pressure chamber 21, the ink in the ink flow path is ejected as droplets from the nozzle 14 which communicates with the pressure chamber 21.

[0054] The support substrate 80 is bonded to the upper surface of the head chip 2, holding the ink chamber forming member 70c of the common ink chamber 70. The support substrate 80 is provided with an opening of approximately the same size and shape as the opening on the lower surface of the ink chamber forming member 70c. Ink in the common ink chamber 70 is supplied to the upper surface of the head chip 2 through the opening on the lower surface of the ink chamber forming member 70c and the opening of the support substrate 80.

[0055] The wiring component 3, such as an FPC (Flexible Printed Circuit), is connected to the wiring substrate 50 via wiring. The piezoelectric element 60 undergoes a displacement operation based on the drive signal transmitted via this wiring to the wiring 51 and the connection portion 52 (conductive component) within the storage unit 41. The wiring component 3 is led out through the support substrate 80 and connected to the drive unit 4.

[0056] The drive unit 4 receives control signals from the control unit of the inkjet recording device, power supply from the power supply unit, etc., and outputs appropriate drive signals of the piezoelectric element 60 to the wiring component 3 according to the ink ejection and non-ejection actions from each nozzle 14. The drive unit 4 is composed of IC (Integrated Circuit) and the like.

[0057] Figure 2 This is a cross-sectional view showing the structure of the nozzle plate 10. Figure 2 The cross-section of the nozzle plate 10 is shown in magnification.

[0058] The nozzle plate 10 has a substrate 11 cut from a substrate and on which nozzles 14 are provided, a protective film 12 provided on the surface of the substrate 11 and the inner wall surface of the nozzles 14, a waterproof film 13 formed on the lower surface of the substrate 11 overlapping with the protective film 12, a stepped portion 151 provided at the edge as a cut, and glue guards 16 provided on both sides of each nozzle 14.

[0059] Furthermore, the surface of the substrate 11 on the upper surface side will be referred to as the first surface 11a, and the surface of the substrate 11 on the lower surface side will be referred to as the second surface 11b.

[0060] The substrate 11 is a plate-shaped component cut from a substrate such as SUS (Steel Use Stainless) with a thickness of approximately 25 μm to 300 μm. By using SUS as the substrate, a nozzle plate 10 with excellent chemical stability and mechanical friction durability for ink can be formed. Furthermore, as described later, when a silicon substrate is used as the substrate 11, a thermal oxide film can also be formed on the outer layer of the substrate 11.

[0061] Nozzle 14 is a cylindrical hole with a circular opening on the second surface 11b of substrate 11.

[0062] The diameter of the opening of the nozzle 14 can be set to about 15μm to 30μm.

[0063] The protective film 12 is a film made of a material that does not dissolve upon contact with ink. For example, in addition to silicon carbide (SiC), silicon carbide oxide (SiOC), and silicon oxide (SiO2), metal oxide films such as aluminum oxide (Al2O3), zirconium oxide (ZrO2), titanium oxide (TiO2), hafnium oxide (HfO2), and tantalum oxide (Ta2O3) can also be used, as well as metal silicate films containing silicon in the metal oxide film (such as tantalum silicate (TaSiO)).

[0064] The thickness of the protective film 12 is not particularly limited, but is preferably set to, for example, around 50nm to 500nm.

[0065] The protective film 12, made of such an ink-resistant material, prevents the substrate 11 from being eroded by ink (especially alkaline or acidic ink). Furthermore, the protective film 12 can also be used as a base film for the waterproof film 13, which will be described later. Since the ink-resistant protective film 12 is not easily peeled off even when in contact with ink, by using the protective film 12 as a base film, it is possible to prevent the waterproof film 13 from peeling off together with the protective film 12, which serves as the base film.

[0066] A waterproof membrane 13 is formed overlapping a protective membrane 12, and an ink ejection surface is formed on its surface. The waterproof membrane 13 is a layer provided to have water resistance to ink and to inhibit the adhesion of ink and foreign matter. As the waterproof membrane 13, it is formed by using a protective membrane 12 made of the raw materials described above as a base film and vapor-depositing a silane coupling agent having a perfluorooxy group.

[0067] In addition, an opening penetrating the waterproof membrane 13 is provided at the location where the nozzle 14 is formed, and ink ejected from the nozzle 14 is ejected from this opening.

[0068] The stepped portion 151 is a cut along the outer periphery of the first surface 11a, and slag 152 generated during laser processing, as described later, is attached to its edge. The stepped portion 151 serves as a space to prevent the slag 152 generated during the shaping process of the recess 15 of the nozzle plate 10 from obstructing the bonding between the nozzle plate 10 and the flow path substrate 20. Additionally, it serves as a space to accommodate the adhesive exposed from the end face of the nozzle plate 10 during the bonding of the nozzle plate 10 and the flow path substrate 20.

[0069] The depth of the step portion 151 is not particularly limited, but is preferably set to 5μm to 10μm.

[0070] The adhesive protector 16 is a recessed portion provided in a manner substantially parallel to the row on which the nozzles 14 are formed. By providing the adhesive protector 16, the possibility of excess adhesive entering the nozzles 14 can be reduced when the nozzle plate 10 is bonded to the pressure chamber substrate 20, which serves as the upper substrate, using adhesive.

[0071] In addition, Figure 2 One of each of the two ribs of the nozzle 14 is provided with the adhesive protection 16, but its position and number are not limited thereto.

[0072] Next, the manufacturing method of the inkjet head 1 in this embodiment will be described, focusing on the manufacturing method of the nozzle plate 10.

[0073] Figure 3 This is a flowchart illustrating the process related to the manufacturing of the nozzle plate 10 (nozzle plate manufacturing process). Additionally, Figures 4A to 4D It is a top view illustrating the nozzle plate manufacturing process and a cross-sectional view along line AB.

[0074] like Figures 4A to 4D As shown, according to the nozzle plate manufacturing process involved in this embodiment, multiple nozzle plates 10 can be manufactured simultaneously from a single substrate.

[0075] In the nozzle plate manufacturing process, initially, as Figure 4A As shown, for the portion of the first surface 11a of the substrate 11 that is processed in the shape in step S106, which is a subsequent process, a groove is formed by wet etching (semi-etching) to form a recess 15 (step S101).

[0076] As a wet etching process, it can be performed by forming a photoresist mask on areas other than the portion where the substrate 11 is grooved and then immersing it in an etching solution. Furthermore, the photoresist mask only needs to be able to resist the etching solution and protect the substrate 11; it can be formed from an inorganic material such as silicon. As for the etching solution, for example, if the substrate 11 is a SUS substrate, a neutral salt etching solution containing an aqueous solution of ferric chloride (FeCl2) or copper chloride (CuCl2) is generally used. If the substrate 11 is a silicon substrate, a mixture of nitric acid (HNO3) and hydrofluoric acid (HF) is generally used. However, it is not limited to these methods, and any known etching solution can be selected.

[0077] After wet etching, the resist mask is removed from the surface of substrate 11.

[0078] In addition, during the groove processing step, a protective adhesive 16 is simultaneously formed as a groove portion parallel to the column forming the nozzle 14.

[0079] Next, as Figure 4B As shown, a perforation process is performed on the substrate 11 to form a nozzle 14 (step S102).

[0080] As a perforation process, a tool is used to stamp the substrate 11. Specifically, the side of the tool where the nozzle forming portion is provided is facing the first surface 11a of the substrate 11, and the nozzle forming portion is pressed against the first surface 11a to perform stamping. As a result, a nozzle recess is formed in the first surface 11a that is recessed toward the second surface 11b, and a nozzle protrusion is formed in the second surface 11b.

[0081] Next, the nozzle protrusion protruding from the second surface 11b is removed by grinding (step S103). Thus, the nozzle 14 opens in the second surface 11b.

[0082] Thus, a nozzle 14 is formed in the substrate 11, extending from the first surface 11a to the second surface 11b.

[0083] Next, a protective film 12 is formed on the nozzle plate 10, and a waterproof film 13 is formed on the second surface 11b, which is the ink ejection surface side (step S104).

[0084] First, the surface of the substrate 11 is cleaned to remove any foreign matter adhering to the substrate 11. The cleaning method for the substrate 11 can be, for example, US cleaning.

[0085] After the substrate 11 is cleaned, its surface is subjected to ion bombardment treatment. Ion bombardment treatment is a process that provides a physical effect on the components being treated by causing ions to collide with the components under reduced pressure.

[0086] Through this ion bombardment treatment, impurities and thin oxide films adhering to the surface of substrate 11 are removed and purified, thereby improving the adhesion of the protective film 12. In addition, oxidation of the surface of substrate 11 is suppressed.

[0087] After ion bombardment treatment, a protective film 12 is formed on the surface of the substrate 11 by plasma CVD. The substrate 11 with the protective film 12 is then cleaned to remove foreign matter adhering to the protective film 12. The cleaning method for the protective film 12 can be the same as described above, namely, US cleaning.

[0088] After the protective film 12 is washed off, as follows Figure 4C As shown, a waterproof membrane 13 is formed on the protective membrane 12. The waterproof membrane 13 is formed by a dry process, such as vacuum evaporation, using a silane coupling agent having a perfluorooxy group. As a silane coupling agent, aminosilane coupling agents such as γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-dioxypropyltriethoxysilane, as well as epoxysilane coupling agents such as γ-glycidyl etheroxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-glycidyl etheroxypropylmethyldiethoxysilane can be used.

[0089] Furthermore, the method for forming the waterproof membrane 13 is not limited to this, and can be formed, for example, by using conventionally known components and methods such as heat drying after immersing the substrate 11 in a liquid obtained by diluting a fluorinated organosilicon compound with a fluorine-based solvent.

[0090] Next, the waterproof membrane 13 formed outside the second surface 11b is removed (step S105). Specifically, the substrate 11 is first placed in an ashing device by masking the second surface 11b with a polyimide tape, and exposed to O2 plasma for several tens of seconds to remove the waterproof membrane 13 formed outside the second surface 11b. Afterward, the polyimide tape is removed and the substrate is cleaned.

[0091] Using the above method, a protective film 12 is formed on the entire surface of the substrate 11, and a waterproof film 13 is formed only on the second surface 11b.

[0092] Next, as Figure 4D As shown, the substrate 11 is processed by laser processing to form its shape (shape processing step, step S106).

[0093] In the shaping process, the recess 15 of the substrate 11, which has been grooved in step S101 (a previous process), is cut off using a laser device, thereby cutting the nozzle plate 10 from the substrate. The laser generated by the laser device is preferably an excimer laser, for example. This is because excimer lasers have short wavelengths and can perform preferred micro-processing. The wavelength of the excimer laser is in the range of 190 nm to 355 nm; specifically, ArF (wavelength 193 nm), KrF (248 nm), XeCl (wavelength 308 nm), and XeF (wavelength 351 nm) are preferably examples. Furthermore, conventionally known lasers such as YAG lasers and CO2 lasers can also be used as the laser.

[0094] In this process, the laser processing is performed by cutting off the recess 15 of the nozzle plate 10 as described above, so that the edge of the nozzle plate 10 after the outer shape processing process is formed as shown in the figure. Figure 2 The step section 151 shown.

[0095] Furthermore, typically, when the shape of the SUS substrate 11 is processed by laser machining, slag 152 forms near the processed portion. However, in this invention, laser machining is performed along the recess 15, so... Figure 2 As shown, slag 152 is formed at the edge of the stepped portion 151.

[0096] Using the above method, a nozzle plate 10 with a stepped portion 151 attached to the edge of the substrate 11 is obtained. The printhead chip 2 is manufactured by stacking the nozzle plate 10 and the flow path substrates 20, 40, and 50, and then combined with the common ink chamber 70, the support substrate 80, the wiring component 3, and the drive unit 4, etc., and embedded into a predetermined outer component, thus completing the inkjet head 1.

[0097] Next, we will describe the experiment conducted to confirm the height of the residue formed during the external processing of the above-described embodiment.

[0098] In this experiment, the height of the slag 152 formed during laser processing of SUS was evaluated.

[0099] Specifically, using a 50μm thick SUS304HTA material as the substrate, laser processing was performed every 20 scans using an MD-U1000C solid-state laser device (manufactured by Keyence Corporation, wavelength: 355nm, pulse width: 14nsec, switching speed: 40kHz, scan speed: 200mm / sec), which utilizes YVO4 crystallization. Various levels of laser output (2.4W / 1.8W / 1.2W / 0.6W) and the presence or absence of auxiliary gas were observed. Next, after cleaning the US material with pure water using 40kHz ultrasound for 20 minutes, the height of the residue 152 generated near the processing area was measured using a VK-X250 laser microscope (manufactured by Keyence Corporation), and the average value was calculated.

[0100] Table I shows the results of this experiment.

[0101] [Table 1]

[0102] Table I

[0103]

[0104] As shown in levels 1-3 of Table 1, the height of the slag 152 can be reduced by decreasing the laser output. However, as shown in levels 4 and 8, it is not preferable to perform shape processing when the output is reduced to below 0.6W.

[0105] Furthermore, as shown in Level 5-7, by using an auxiliary gas, the height variation of the sludge 152 caused by changes in laser output can be reduced, and the height is stabilized below 5 μm.

[0106] As shown in Experiment 1, the height of the slag 152 generated during laser processing is approximately 5 μm, especially less than 10 μm. Therefore, if the depth of the step portion 151 is approximately 5 μm, the slag 152 is less likely to cause poor adhesion or voids when bonding to the pressure chamber substrate 20. Furthermore, if the depth of the step portion 151 is approximately 10 μm, regardless of the conditions during laser processing, the slag 152 can be prevented from becoming an obstacle to adhesion after the shape processing.

[0107] As described above, the method for manufacturing the nozzle plate 10 in the above embodiments includes at least: a groove processing step, in which groove processing is performed on the portion to be shaped by wet etching to form a plurality of recesses 15 in a substrate; a nozzle forming step, in which a plurality of nozzles 14 are formed by perforation and grinding; and a shape processing step, in which the shape processing of the plurality of nozzle plates 10 is performed along the recesses 15 by laser processing.

[0108] According to this method, the residue 152 generated by the shape processing process is generated at the step portion 151 formed by the groove processing process. Therefore, when the nozzle plate 10 is bonded to the pressure chamber base plate 20, the occurrence of defects such as poor bonding and voids can be suppressed.

[0109] Furthermore, in the manufacturing method of the nozzle plate 10 according to the above embodiment, it is not necessary to remove the residue 152 generated on the edge of the nozzle plate 10 by grinding in order to suppress the aforementioned undesirable phenomenon. Therefore, the nozzle plate 10 can be manufactured efficiently, resulting in excellent productivity.

[0110] Furthermore, in the manufacturing method of the nozzle plate 10 according to the above embodiment, as shown in FIG4, each processing step can be performed in such a way that multiple nozzle plates 10 can be manufactured from a single substrate 11. Therefore, multiple nozzle plates 10 can be manufactured efficiently, resulting in excellent productivity.

[0111] Furthermore, in the manufacturing method of the nozzle plate 10 according to the above embodiment, the shape is processed by laser processing. Therefore, compared with the case where the shape is processed by wet etching, there is no need for the formation and removal of a resist mask, and no resist residue is generated inside the nozzle 14. Therefore, the nozzle plate 10 can be manufactured efficiently with excellent productivity.

[0112] Furthermore, in the manufacturing method of the nozzle plate 10 according to the above embodiment, even if slag 152 is generated during the shape processing step, the aforementioned undesirable phenomenon can be suppressed. Therefore, the nozzle plate 10 can be provided inexpensively without the need for short-pulse laser equipment with pulse widths of picoseconds or femtoseconds.

[0113] Furthermore, in the nozzle plate 10 manufactured by the manufacturing method described in the above embodiment, slag 152 is generated in the step portion 151. Therefore, when bonding with the pressure chamber substrate 20, which is the upper substrate, using an adhesive, even if a large amount of adhesive is used, the slag 152 can be prevented from becoming a wall and being exposed to the side.

[0114] Furthermore, by using the nozzle plate 10 manufactured by the manufacturing method described in the above embodiments, the inkjet head 1 can be manufactured cheaply and efficiently, resulting in excellent productivity.

[0115] Furthermore, the present invention is not limited to the above-described embodiments and various modifications can be made.

[0116] For example, in the above embodiment, the substrate of the nozzle plate 10 is made of SUS, but it is not limited to this. For example, conventionally known raw materials such as silicon substrates or materials made by electroforming metals such as Ni can also be used.

[0117] Furthermore, in the above embodiment, an example of forming a protective film 12 on the entire surface of the substrate 11 was used for illustration, but it is not limited to this. The protective film 12 may also be provided on at least a portion of the first surface 11a of the substrate 11 and the inner wall surface of the nozzle 14 (i.e., any range where ink resistance is required due to the possibility of ink contact).

[0118] Furthermore, the protective film 12 is designed as a single layer, but its structure is not limited to this; it can also be designed as a multi-layer structure. Additionally, if the protective film 12 is not required, it may not be provided in the nozzle plate 10.

[0119] Alternatively, the inner wall surface of the nozzle 14 can be formed into a conical shape such that the cross-sectional area parallel to the first surface 11a becomes smaller the closer it is to the opening of the nozzle 14.

[0120] Alternatively, the nozzle 14 provided on the nozzle plate 10 may also be configured to have a connecting passage having an opening wider than the nozzle 14, and an ink flow path that guides ink that is not ejected from the nozzle 14. The shape of the nozzle 14 is also not limited to, for example... Figure 2 It is roughly frustum-shaped as shown.

[0121] In addition, if it is not necessary to make the ink ejection surface of the inkjet head 1 waterproof, the waterproof membrane 13 may not necessarily be provided in the nozzle plate 10.

[0122] Furthermore, in the above embodiment, an inkjet head 1 in vent mode, which ejects ink by deforming the piezoelectric element 60 to change the pressure of the ink in the pressure chamber 21, was described as an example, but it is not intended to be limited thereto. For example, the present invention can also be applied to a shear mode inkjet head, in which a pressure chamber is provided inside a piezoelectric element and the piezoelectric element on the wall of the pressure chamber undergoes shear mode displacement to change the pressure of the ink in the pressure chamber. In addition, the invention is not limited to the method of deforming the pressure chamber; for example, the present invention can also be applied to a thermal inkjet head, in which ink is ejected by heating to generate bubbles.

[0123] Furthermore, in the above embodiment, the recess 15 is formed by wet etching in the groove processing step, but it is not limited to this and can also be formed by laser processing. However, when laser processing is performed, the substrate may become skewed or warped, so it is preferable to form it by wet etching.

[0124] Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above embodiments, but includes the scope of the invention as set forth in the claims and its equivalents.

[0125] Industrial availability

[0126] This invention can be used in nozzle plates to suppress poor adhesion or voids during bonding.

[0127] Symbol Explanation

[0128] 1 inkjet head

[0129] 10 Nozzle Plate

[0130] 11a Page 1

[0131] Page 2 of 11b

[0132] 13 Waterproof Membrane

[0133] 14 nozzles

[0134] 15 recesses

[0135] 20 Pressure Chamber Substrate (Upper Substrate)

[0136] 151 steps

[0137] 152 Sticky Residue

Claims

1. A nozzle plate that is a nozzle plate of an inkjet head, wherein the nozzle plate has: a first surface that is bonded to an upper substrate by an adhesive; and a second surface on which an opening portion of a nozzle that discharges ink is provided, the first surface has a step portion formed at a peripheral portion, the peripheral portion of the second surface is planar.

2. The nozzle plate according to claim 1, wherein a scum is attached to the step portion.

3. The nozzle plate according to claim 1, wherein a base material that forms the nozzle plate is silicon or a metal.

4. The nozzle plate according to any one of claims 1 to 3, wherein the step portion has a depth of 5 μm or more and 10 μm or less in a central direction of the nozzle plate.

5. An inkjet head that has the nozzle plate according to any one of claims 1 to 4.

6. A method of manufacturing a nozzle plate that is the method of manufacturing the nozzle plate according to any one of claims 1 to 4, comprising: a groove processing step of forming a recess portion on a first surface in a manner that forms a plurality of outer shapes of nozzle plates for one base material; a nozzle forming step of forming a nozzle in a manner that forms an opening portion on a second surface of the base material; and an outer shape processing step of cutting out the nozzle plate from the base material by cutting the recess portion by laser processing.

7. The method of manufacturing a nozzle plate according to claim 6, wherein the recess portion is formed by wet etching.

8. The method of manufacturing a nozzle plate according to claim 6 or 7, wherein a water repellent film forming step of forming a water repellent film on the second surface is included.

9. A method of manufacturing an inkjet head, comprising: a nozzle plate manufacturing step of manufacturing the nozzle plate according to any one of claims 1 to 4; and a bonding step of bonding the first surface of the nozzle plate and an upper substrate by an adhesive.

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