Patent Description:
The inkjet head, which ejects ink, consists of the nozzle plate, which is a base material with a nozzle formed on it, to which a channel base material is bonded with an adhesive, and ink is ejected from the nozzle. As a method of forming the nozzle on the base material, a tool is pressed into the base material and squeezed so that the concave portion reaches the back surface of the base material, and then the convex portion on the back surface of the base material is polished to transfer the shape of the tool so that it penetrates the base material (see, for example, <CIT>).

SUS (Steel Use Stainless, stainless steel) and other metals are used as the base material of the nozzle plate from the viewpoints of chemical stability against ink and durability against mechanical friction. Wet etching with an etching solution (see <CIT>) and laser etching with a laser device (see <CIT>) are known as methods for processing the nozzle plate external shape from the metal plate on which the nozzle is formed. A nozzle plate manufacturing method and a nozzle plate is also known from <CIT>, which describes before fixing the nozzle plate <NUM> having nozzles 11a formed in an array to a surface of a channel constituting body comprising a laminated body composed of a manifold plate, a spacer plate and a base plate of the head unit <NUM>, a recessed groove <NUM> is preliminarily formed exactly in a shape of the outer periphery of the nozzle plate <NUM> into a material plate <NUM>, and a step part <NUM> is formed by separating the nozzle plate along a bottom part of the recessed groove <NUM> by laser beam machining. Although flashes/burrs <NUM> project at bottom edges of the step part <NUM>, leading ends of the flashes/burrs <NUM> are prevented from projecting outer than the surface of the nozzle plate <NUM>. Moreover, a nozzle plate manufacturing method and a nozzle plate is also known from <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

However, when wet etching is used to perform external shaping, the resist mask may penetrate into the nozzle, and resist residue may remain in the nozzle even after the resist is peeled off after the external shaping.

Furthermore, when external shaping is performed by laser etching, bonding defects or voids may occur near the laser processing position due to convexity caused by dross. Although the generation of dross can be suppressed by using a short-pulse laser such as picosecond or femtosecond lasers as the laser equipment, the cost of the equipment is higher than that of the nanosecond pulse laser equipment commonly used, making it less economical.

In addition, when bonding the channel base material to the nozzle plate, there is a risk of adhesive defects where the adhesive protrudes to the sides.

The present invention was made in view of these circumstances, and its purpose is to provide a nozzle plate, an inkjet head, a nozzle plate manufacturing method, and an inkjet head manufacturing method that can suppress bonding defects or voids during bonding.

In order to solve the above problem, a nozzle plate manufacturing method of the present invention is described in claim <NUM>. Preferred embodiments are described in the dependent claims.

According to the nozzle plate, the inkjet head including the nozzle plate, the nozzle plate manufacturing method, and the inkjet head manufacturing method of the present invention, it is possible to suppress the occurrence of bonding defects or voids during bonding.

Hereinafter, embodiments of the nozzle plate, the inkjet head including the nozzle plate, the nozzle plate manufacturing method, and the inkjet head manufacturing method will be described based on the drawings.

<FIG> is an overall view of the inkjet head <NUM> according to the embodiment, and <FIG> is a cross-sectional view of the inkjet head <NUM> of <FIG> viewed from the side (-X direction side) along the IB-IB line. <FIG> shows a cross-section of the inkjet head <NUM> in the surface containing the four nozzles <NUM> included in four nozzle rows.

The inkjet head <NUM> includes a head chip <NUM>, a common ink chamber <NUM>, a support substrate <NUM>, a wiring member <NUM>, a drive section <NUM>, and the like.

The head chip <NUM> is configured to eject ink from the nozzles <NUM>, and is made up of multiple (in this case, four) board-like substrates that are stacked and formed. The lowest substrate in the head chip <NUM> is the nozzle plate <NUM>. The nozzle plate <NUM> has multiple nozzles <NUM>, and ink can be ejected nearly perpendicularly to the ink ejection surface (the exposed surface of the nozzle plate <NUM>) where the openings of the nozzles <NUM> are provided. On the opposite side of the nozzle plate <NUM> from the ink ejection surface, the pressure chamber substrate <NUM> (chamber plate), spacer substrate <NUM>, and wiring substrate <NUM> are bonded and stacked by adhesive or the like in order toward the upper direction (+Z direction). In the following, the nozzle plate <NUM>, pressure chamber substrate <NUM>, spacer substrate <NUM>, and wiring substrate <NUM> are also individually or collectively referred to as channel substrates <NUM>, <NUM>, <NUM>, <NUM>, and the like.

These channel substrates <NUM>, <NUM>, <NUM>, and <NUM> are provided with ink channels that are connected to the nozzles <NUM>, and are open on the surface on the exposed side (+Z direction side) of the wiring substrate <NUM>. On the exposed surface of the wiring substrate <NUM>, a common ink chamber <NUM> is provided to cover all openings. The common ink chamber <NUM> has, at the upper section, an ink supply portion 70a that supplies ink to the ink chamber forming member 70c and an ink discharge portion 70b that discharges ink from the ink chamber forming member 70c. The ink stored in the ink chamber forming member 70c of the common ink chamber <NUM> is supplied to each nozzle <NUM> from the opening of the wiring substrate <NUM>.

In the middle of the ink channel, a pressure chamber <NUM> is provided. The pressure chamber <NUM> is provided through the pressure chamber substrate <NUM> in the vertical direction (Z direction), and the top surface of the pressure chamber <NUM> is composed of a diaphragm <NUM> provided between the pressure chamber substrate <NUM> and the spacer substrate <NUM>. The pressure change is imparted to the ink in the pressure chamber <NUM> by the deformation of the diaphragm <NUM> (pressure chamber <NUM>) due to the displacement (deformation) of the piezoelectric element <NUM> in the storage section <NUM> which is provided adjacent to the pressure chamber <NUM> via the diaphragm <NUM>. By an appropriate pressure change being applied to the ink in the pressure chamber <NUM>, the ink in the ink channel is ejected as a droplet from the nozzle <NUM> that is connected to the pressure chamber <NUM>.

The support substrate <NUM> is bonded to the top surface of the head chip <NUM> and holds the ink chamber forming member 70c of the common ink chamber <NUM>. The support substrate <NUM> is provided with the opening of approximately the same size and shape as the opening on the bottom surface of the ink chamber forming member 70c. The ink in the common ink chamber <NUM> is supplied to the top surface of the head chip <NUM> through the opening in the bottom surface of the ink chamber forming member 70c and the opening in the support substrate <NUM>.

The wiring member <NUM> is, for example, an FPC (Flexible Printed Circuits), or the like, and is connected to the wiring of the wiring substrate <NUM>. The piezoelectric element <NUM> is displaced by the drive signal transmitted to the wiring <NUM> and the connection <NUM> (conductive member) in the storage section <NUM> via this wiring. The wiring member <NUM> is drawn through the support substrate <NUM> and connected to the drive section <NUM>.

The drive section <NUM> receives control signals from the control section of the inkjet recording device and power supply from the power supply section. The drive section <NUM> outputs appropriate drive signals of the piezoelectric element <NUM> to the wiring member <NUM> according to the ink ejection or non-ejection operation from each nozzle <NUM>. The drive section <NUM> is composed of an IC (Integrated Circuit) or the like.

<FIG> is a cross-sectional view showing the configuration of the nozzle plate <NUM>. <FIG> shows an enlarged cross-sectional view of the nozzle plate <NUM>.

The nozzle plate <NUM> consists of a substrate <NUM> cut from a base material and provided with nozzles <NUM>, a protective film <NUM> provided on the plate surface of the substrate <NUM> and the inner wall surfaces of the nozzles <NUM>, a water repellent film <NUM> formed on the underside of substrate <NUM> to be overlaid on the protective film <NUM>, a step <NUM> that is a cut provided at the edge, and glue guards <NUM> provided on both sides of each nozzle <NUM>.

In the following, the upper side surface of the substrate <NUM> is referred to as the first surface 11a, the lower side surface of the substrate <NUM> is referred to as the second surface 11b.

The substrate <NUM> is a plate-shaped member cut from a base material such as SUS (Steel Use Stainless, stainless steel) with a thickness of approximately <NUM> to <NUM>. By using SUS as the base material, the nozzle plate <NUM> can be formed with excellent chemical stability against ink and mechanical friction durability. As described below, when a silicon substrate is used as the substrate <NUM>, a thermal oxide film may be formed on the outer layer of the substrate <NUM>.

The nozzle <NUM> is a cylindrical hole with a circular opening on the second surface 11b of the substrate <NUM>.

The diameter of opening of the nozzle <NUM> can be approximately <NUM> to <NUM>.

For the protective film <NUM>, a material that does not dissolve upon contact with the ink, such as silicon carbide (SiC), silicon oxycarbide (SiOC), and silicon oxide ( SiO<NUM>), , as well as metal oxide films such as aluminum oxide (Al<NUM>O<NUM>), zirconium oxide (ZrO<NUM>), titanium oxide (TiO<NUM>), hafnium oxide (HfO<NUM>) and tantalum oxide (Ta<NUM>O<NUM>), and metal silicate films containing silicon in metal oxide films (tantalum silicate (TaSiO), etc.) can be used.

The thickness of the protective film <NUM> is not limited, but is desirably, for example, <NUM> to <NUM>.

The protective film <NUM> made of such ink-resistant material inhibits the substrate <NUM> from being eroded by ink (especially, alkaline or acidic ink). The protective film <NUM> may also be used as a base film for the water repellent film <NUM> described below. Since the ink-resistant protective film <NUM> is not easily peeled off when it comes into contact with ink, by using the protective film <NUM> as the base film, it is possible to suppress the peeling of the water repellent film <NUM> together with the protective film <NUM> as the base film.

The water repellent film <NUM> is formed on top of the protective film <NUM>, and its surface forms the ink ejection surface. The water repellent film <NUM> is a layer provided to have water repellency against ink and to inhibit adhering of ink and foreign matter. As the water repellent film <NUM>, the water repellent film <NUM> is formed by vapor deposition of a silane coupling agent having perfluoroxyl groups, using the protective film <NUM> made of the aforementioned material as the base film.

The water repellent film <NUM> has openings through the water repellent film <NUM> at the positions where the nozzles <NUM> are formed, and ink ejected from the nozzles <NUM> is ejected through the openings.

The step <NUM> is a cut provided along the periphery of the first surface 11a, and dross <NUM> generated by laser processing, which will be described later, is attached to the edge. The step <NUM> is a space that prevents the dross <NUM> from interfering with the bonding of the nozzle plate <NUM> and the channel substrate <NUM>, the dross <NUM> being generated when external shaping is performed to the recess <NUM> of the nozzle plate <NUM>. The step <NUM> is also a space to contain the adhesive that protrudes from the edge surface of the nozzle plate <NUM> during the bonding of the nozzle plate <NUM> and the channel substrate <NUM>.

The depth of the step <NUM> is not limited, but is preferably <NUM> to <NUM>.

The glue guard <NUM> is a recessed groove section provided so that it is nearly parallel to the row of nozzles <NUM>. By providing the glue guard <NUM>, when the nozzle plate <NUM> is bonded to the pressure chamber substrate <NUM>, which is the upper layer substrate, with adhesive, there is less risk of excess adhesive getting into the nozzle <NUM>.

In <FIG>, one glue guard <NUM> is provided on each side of the nozzle <NUM>, but the position and number of glue guards are not limited to this.

Next, the manufacturing method of the inkjet head <NUM> of the embodiment is described, focusing on the manufacturing method of the nozzle plate <NUM>.

<FIG> is a flowchart showing the procedure of the process for manufacturing the nozzle plate <NUM> (nozzle plate manufacturing process). <FIG> are top views and cross-sectional views along the A-B line illustrating the nozzle plate manufacturing process.

As shown in <FIG>, according to the nozzle plate manufacturing process for the embodiment, multiple nozzle plates <NUM> can be manufactured simultaneously from a single base material.

In the nozzle plate manufacturing process, first, as shown in <FIG>, the portion of the first surface 11a of the substrate <NUM> that is to be subjected to external shaping in step S106 which is a later process is subjected to grooving (half etching) by a wet etching process to form the recess <NUM> (Step S101).

The wet etching process can be performed by forming a resist mask on the substrate <NUM>, excluding the grooving area, and immersing it in the etchant. It is sufficient that the resist mask is able to protect the substrate <NUM> against the etchant, and the resist mask can be made of inorganic material such as silicon, for example. As an etchant, for example, if the substrate <NUM> is a SUS base material, a neutral salt etchant, which is an aqueous solution containing ferric chloride (FeCl<NUM>), copper chloride (CuCl<NUM>) or the like is generally used. When the substrate <NUM> is a silicon substrate, a mixture of nitric acid (HNO<NUM>) and hydrofluoric acid (HF) is generally used. However, it is not limited to this, and any of the known etchants can be selected.

After the wet etching process, the resist mask is removed from the surface of the substrate <NUM>.

In the grooving process, the glue guard <NUM> which is the concave groove section parallel to the row of nozzles <NUM> to be formed is formed at the same time.

Next, as shown in <FIG>, punching is performed on the substrate <NUM> to form the nozzles <NUM> (Step S102).

As the punching, the tool is used to press the substrate <NUM>. Specifically, one side of the nozzle forming portion of the tool and the first surface 11a of the substrate <NUM> are made to face each other, and the nozzle forming portion is pressed against the first surface 11a. As a result, nozzle recesses which are concave toward the second surface 11b are formed on the first surface 11a, and nozzle convex portions are formed on the second surface 11b.

Next, the nozzle convex portions protruding from the second surface 11b are polished and removed (Step S103). Then, the nozzles <NUM> are opened on the second surface 11b.

As a result, the substrate <NUM> has nozzles <NUM> that penetrate from the first surface 11a to the second surface 11b.

Next, the protective film <NUM> is formed on the nozzle plate <NUM>, and the water repellent film <NUM> is formed on the second surface 11b, which is the ink ejection surface side (Step S104).

First, the surface of the substrate <NUM> is cleaned to remove foreign matter adhering to the substrate <NUM>. The method of cleaning the substrate <NUM> can be, for example, US cleaning.

After cleaning the substrate <NUM>, an ion bombardment treatment is performed on the surface of the substrate <NUM>. Ion bombardment treatment is a treatment in which physical effects are exerted on the material to be treated by bombarding the material to be treated with ions in a reduced pressure environment.

This ion bombardment treatment removes impurities and thin oxide films from the surface of the substrate <NUM> to clean it and improve the adhesion property of the protective film <NUM>. In addition, oxidation of the surface of the substrate <NUM> is suppressed.

After ion bombardment treatment, the protective film <NUM> is formed on the surface of the substrate <NUM> by the plasma CVD method, and the substrate <NUM> having the protective film <NUM> is cleaned to remove foreign matter adhering to the protective film <NUM>. The method of cleaning the protective film <NUM> can be US cleaning as described above.

After cleaning the protective film <NUM>, as shown in <FIG>, the water repellent film <NUM> is formed on the protective film <NUM>. The water repellent film <NUM> is formed by a dry process, such as vacuum evaporation, using a silane coupling agent having perfluoroxyl groups, for example. As the silane coupling agents, amino silane 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-ureidopropyltriethoxysilane, and epoxysilane coupling agents such as γ-glycidoxypropyltrimethoxysilane, β-(<NUM>,<NUM>-epoxycyclohexyl)ethyl trimethoxysilane, and γ-glycidoxypropyl methyl diethoxysilane are applicable.

The method of forming the water repellent film <NUM> is not limited to this. The water repellent film <NUM> may be formed on the basis of conventionally known components and methods, for example, by immersing the substrate <NUM> in a solution of a fluorine-containing organosilicon compound diluted with a fluorinated solvent and then thermally drying it.

Next, the water repellent film <NUM> formed on surfaces other than the second surface 11b is removed (Step S105). Specifically, first, the second surface 11b is masked with polyimide tape and the substrate <NUM> is installed in an ashing machine. Exposure to O<NUM> plasma is made for several tens of seconds to remove the water repellent film <NUM> formed on the surfaces other than the second surface 11b. The polyimide tape is then removed and cleaned.

By the method described above, the protective film <NUM> is formed on the entire surface of the substrate <NUM>, and the water repellent film <NUM> is formed only on the second surface 11b.

Next, as shown in <FIG>, external shaping is performed on the substrate <NUM> by laser processing (external shaping process, step S106).

In the external shaping process, the nozzle plate <NUM> is cut out from the base material by performing the laser processing with the laser equipment along the recess <NUM> of the substrate <NUM> on which the grooving was performed in step S101 which is a previous process, and by cutting the recess <NUM>. For example, excimer laser light can be preferably used as the laser light generated by the laser equipment. This is because excimer laser light has a short wavelength and is capable of desirable microprocessing. The wavelength of excimer laser light ranges from <NUM> to <NUM>. Specifically, for example, ArF (wavelength of <NUM>), KrF (<NUM>), XeCl (wavelength of <NUM>), XeF (wavelength of <NUM>), and the like are preferably cited. Conventional known laser beams such as YAG laser, CO<NUM> laser, and the like may be used as laser beams.

Since the laser processing in this process is performed by cutting the recess <NUM> of the nozzle plate <NUM> as described above, the step <NUM> as shown in <FIG> is formed at the edge of the nozzle plate <NUM> after the external shaping process.

In addition, when the external shaping is performed on the substrate <NUM> which is SUS by laser processing, in general, the dross <NUM> is formed near the processed portion. However, in the present invention, laser processing is performed along the recess <NUM>, and thus the dross <NUM> is formed at the edge of the step <NUM> as shown in <FIG>.

By the method described above, the nozzle plate <NUM> having the step <NUM> with the dross <NUM> formed on the edge of the substrate <NUM> is obtained. The head chip <NUM> is manufactured by stacking the nozzle plate <NUM> and the channel substrates <NUM>, <NUM>, and <NUM>, and is combined with the common ink chamber <NUM>, the support substrate <NUM>, the wiring member <NUM>, and the drive section <NUM> to be incorporated into a predetermined exterior member. Thereby, the inkjet head <NUM> is completed.

Next, the experiment conducted to confirm the height of the dross formed by the external shaping in the embodiment will be explained.

In this experiment, the height of the dross <NUM> formed when SUS is laser processed was evaluated.

Specifically, SUS304HTA material with a thickness of <NUM> was used as the base material, and a solid-state laser system using YVO4 crystals, MD-U1000C (manufactured by Keyence Corporation, wavelength: <NUM>, pulse width: <NUM> nsec, switch: <NUM>, scan speed: <NUM>/sec) was used to perform laser processing by <NUM> scans at a time for each level of laser output (<NUM> W / <NUM> W / <NUM> W / <NUM>. 6W) with or without assist gas. Next, <NUM> minutes of US cleaning was performed in pure water using <NUM> ultrasonic waves. After the US cleaning, a laser microscope, VK-X250 (manufactured by Keyence Corporation) was used to measure the height of the dross <NUM> generated near the processed portion, and the average value was calculated.

Table I is a table showing the results of this experiment.

As shown in levels <NUM> to <NUM> of Table <NUM>, as the laser output is reduced, the height of the dross <NUM> can be reduced. However, as shown in levels <NUM> and <NUM>, if the output is reduced to <NUM> W or lower, it is not preferable because it is no longer possible to perform the external shaping.

In addition, as shown in levels <NUM> to <NUM>, the use of an assist gas can reduce the change in the height of the dross <NUM> due to changes in laser output, and the height can be stabilized at <NUM> or less.

As shown in Experiment <NUM>, the height of dross <NUM> generated during laser processing is approximately <NUM>, especially <NUM> or less. Therefore, if the depth of the step <NUM> is approximately <NUM>, the dross <NUM> is less likely to cause bonding defects or void generation when bonding to the pressure chamber substrate <NUM>. If the depth of the step <NUM> is approximately <NUM>, the dross <NUM> can be prevented from becoming an obstacle to bonding after external shaping, regardless of the conditions at the time of laser processing.

As described above, the method for manufacturing the nozzle plate <NUM> according to the embodiment at least includes a grooving process that is forming multiple recesses <NUM> in a single substrate by grooving in the wet etching on the portion to be subjected to the external shaping, a nozzle forming process that is forming multiple nozzles <NUM> by punching and polishing, and an external shaping process that is performing external shaping of the multiple nozzle plates <NUM> along the recesses <NUM> by laser processing.

According to such a method, the dross <NUM> generated by the external shaping process is generated in the step <NUM> formed by the grooving process. Therefore, when the nozzle plate <NUM> is bonded to the pressure chamber substrate <NUM>, the occurrence of defects such as bonding defects and void generation can be suppressed.

In addition, in the method for manufacturing the nozzle plate <NUM> according to the embodiment, it is not necessary to remove the dross <NUM> generated at the edge of the nozzle plate <NUM> by polishing in order to suppress the occurrence of the aforementioned defects. Therefore, the nozzle plate <NUM> can be manufactured efficiently and the productivity is excellent.

In addition, in the method for manufacturing the nozzle plate <NUM> according to the embodiment, as shown in <FIG>, each process can be performed to produce multiple nozzle plates <NUM> from a single substrate <NUM>. Therefore, multiple nozzle plates <NUM> can be efficiently manufactured, and the productivity is excellent.

In addition, in the method for manufacturing the nozzle plate <NUM> according to the embodiment, since the external shaping is performed by laser processing, compared to the case where the external shaping is performed by wet etching, the process of forming and removing the resist mask becomes unnecessary, and resist residue inside the nozzle <NUM> is not generated. Therefore, the nozzle plate <NUM> can be manufactured efficiently and the productivity is excellent.

In addition, in the method for manufacturing the nozzle plate <NUM> according to the embodiment, even if the dross <NUM> is generated during the external shaping process, the occurrence of the aforementioned defects can be suppressed. Therefore, the nozzle plate <NUM> can be provided at a low cost without the need to use a short pulse laser device with a pulse width of picoseconds or femtosecond order.

In addition, the nozzle plate <NUM> manufactured by the manufacturing method according to the embodiment has the dross <NUM> at the step <NUM>. Therefore, in bonding with the pressure chamber substrate <NUM>, which is the upper layer substrate, with the adhesive, even if the amount of adhesive is large, it is possible to prevent the dross <NUM> from becoming a wall to make it protrude to the sides.

In addition, by using the nozzle plate <NUM> manufactured by the manufacturing method according to the embodiment, the inkjet head <NUM> can be manufactured inexpensively and efficiently, and the productivity is excellent.

The present invention is not limited to the embodiment, but can be modified in various ways.

For example, in the embodiment, the base material of the nozzle plate <NUM> is made of SUS, but the base material of the nozzle plate <NUM> is not limited to this. For example, other conventionally known materials such as a silicon substrate or electroformed metal such as Ni may be used.

In the embodiment, an example of forming the protective film <NUM> on the entire surface of the substrate <NUM> is used, but the range of forming the protective film <NUM> is not limited to this. The protective film <NUM> may be provided on at least a portion of the first surface 11a and the inner wall surface of nozzle <NUM> in the surface of the substrate <NUM> (that is, any range which ink may come into contact with and requires the ink resistance).

Although the protective film <NUM> is a monolayer structure, the composition of the protective film <NUM> is not limited to this, and a multilayer structure is also acceptable. If the protective film <NUM> is unnecessary, the nozzle plate <NUM> does not need to be provided with the protective film <NUM>.

The inner wall surface of the nozzle <NUM> may be tapered so that the closer it is to the opening of the nozzle <NUM>, the smaller the cross-sectional area parallel to the first surface 11a is.

The nozzle <NUM> in the nozzle plate <NUM> may include a connecting passageway having an opening wider than the nozzle <NUM>, an ink channel leading ink that is discharged without being ejected from the nozzle <NUM>, or the like. The shape of the nozzle <NUM> is not limited to the abbreviated conical shape as shown in <FIG>.

In cases where the inkjet head <NUM> does not need to have the water repellency in the ink ejection surface, the nozzle plate <NUM> does not necessarily need to be provided with the water repellent film <NUM>.

The embodiment illustrates, as an example, the inkjet head <NUM> in the vent mode that fluctuates the pressure of ink in the pressure chamber <NUM> by deforming the piezoelectric element <NUM> and causes ink to be ejected. However, this is not intended to be a limitation. For example, the present invention may be applied to the inkjet head in the shear mode, in which a pressure chamber is provided inside the piezoelectric body and the pressure of ink in the pressure chamber is fluctuated by generating the shear mode type displacement in the piezoelectric body on the wall of the pressure chamber. The present invention is not limited to the method of deforming the pressure chamber. For example, the present invention may also be applied to the inkjet head of the thermal method which ejects ink by generating bubbles in the ink by heating.

In the embodiment, in the grooving process, the recess <NUM> is formed by wet etching. However, the processing to form the recess <NUM> is not limited to this, and the recess <NUM> may be formed by laser processing. However, it is preferable to form the recess <NUM> by wet etching since laser processing may cause distortion and warping of the base material.

Claim 1:
A nozzle plate manufacturing method for a nozzle plate (<NUM>), the nozzle plate (<NUM>) comprising:
a first surface (11a) that is bonded to an upper layer substrate (<NUM>) by an adhesive; and
a second surface (11b) in which an opening of a nozzle (<NUM>) that ejects an ink is provided, wherein
a step (<NUM>) is formed at an edge of the first surface (11a),
the nozzle plate manufacturing method comprising:
a grooving process (S101) that is forming a recess (<NUM>) in the first surface (11a) so as to form external shapes of multiple nozzle plates (<NUM>) for a single base material, wherein the recess (<NUM>) is formed by wet etching;
a nozzle forming process (S102, S103) that is forming the nozzle (<NUM>) such that the opening is formed in the second surface (11b) of the base material; and
an external shaping process (S106) that is cutting the recess (<NUM>) by laser processing and cutting out the nozzle plates (<NUM>) from the base material.