JP2024082955A - Manufacturing method of passage plate for inkjet head, manufacturing method of inkjet head, passage plate for inkjet head, and inkjet head - Google Patents

Abstract

To provide a manufacturing method of a passage plate including a vibration plate made of metal for inkjet, which can form a through-hole while enhancing processing accuracy and manufacturing efficiency, regardless of a kind of the metal and can suppress corrosion of the vibration plate.SOLUTION: The manufacturing method of a passage plate comprises the steps of: preparing a substrate in which a piezoelectric body and a first insulation layer which has a first opening part through which the piezoelectric body is exposed and a second opening part formed at a position different from a position of the piezoelectric body are formed on a support plate; forming a resist pattern of covering the second opening part; forming a metal film on a surface of the substrate having the resist pattern formed thereon; and removing the resist patter together with the metal film covering the resist pattern.SELECTED DRAWING: Figure 3

Description

The present invention relates to a method for manufacturing a flow path plate for an inkjet head, a method for manufacturing an inkjet head, a flow path plate for an inkjet head, and an inkjet head.

Piezo inkjet heads, which have a piezoelectric element that deforms when a voltage is applied, are known as inkjet heads used in inkjet printers and the like. Such inkjet heads usually have a laminate of a piezoelectric element and a diaphragm that deforms as the piezoelectric element deforms, and a pressure chamber whose volume changes as the piezoelectric element and the diaphragm deform.

In such an inkjet head, the vibration plate included in the laminate is formed over an area larger than the piezoelectric body, and then through holes are formed in the portions through which the ink flows. As a method for forming such through holes in the vibration plate, for example, Patent Document 1 discloses a method for forming through holes by etching an elastic film (vibration plate) made of silicon dioxide.

JP 2008-114371 A

However, there is a growing demand for inkjet heads that can improve the ink ejection speed and eject high-viscosity ink. In manufacturing such inkjet heads, it is necessary to increase the rigidity of the plate (hereinafter referred to as the flow path plate) that includes the diaphragm having the above-mentioned through holes.

To increase the rigidity of the flow path plate, the inventors considered using a metallic diaphragm. However, when attempting to form through holes by etching in a flow path plate including a metallic diaphragm as in Patent Document 1, depending on the type of metal, the processing accuracy and manufacturing efficiency decreased.

The present invention has been made in consideration of the above circumstances, and aims to provide a method for manufacturing a flow path plate including a metallic diaphragm, which is capable of forming through holes with improved processing accuracy and manufacturing efficiency regardless of the type of metal, a method for manufacturing an inkjet flow path plate, an inkjet head including the flow path plate, a flow path plate, and an inkjet head including the flow path plate.

In order to solve the above problems, one aspect of the present invention relates to a method for manufacturing a flow path plate for an inkjet head according to the following items [1] to [8].
[1] A method for manufacturing a flow path plate for an inkjet head, comprising the steps of: preparing a substrate on a support plate on which a piezoelectric body and a first insulating layer having a first opening exposing the piezoelectric body and a second opening formed in a position different from that of the piezoelectric body are formed; forming a resist pattern covering the second opening; forming a metal film on a surface of the substrate on which the resist pattern is formed; and removing the resist pattern together with the metal film covering the resist pattern.
[2] The method for manufacturing a flow path plate for an inkjet head described in [1], wherein in the step of forming the metal film, a laminate of multiple layers having different metal compositions is formed as the metal film.
[3] The method for manufacturing a flow path plate for an inkjet head described in [2], wherein in the step of forming the metal film, a laminate of a plurality of metal layers is formed, and the laminate is made of a metal selected from the group consisting of tungsten, molybdenum, chromium, titanium, nickel, iridium, platinum, copper, gold, and alloys thereof, and includes two or more metal layers having different compositions.
[4] The method for manufacturing a flow path plate for an inkjet head according to any one of [1] to [3], wherein in the step of forming the metal film, a metal film having a Young's modulus of 150 GPa or more and 250 GPa or less is formed.
[5] The method for manufacturing a flow path plate for an inkjet head described in any one of [1] to [4], wherein the preparing step includes a step of forming a piezoelectric body on a support plate, and a step of forming a first insulating layer on the support plate on which the piezoelectric body has been formed.
[6] The method for manufacturing a flow path plate for an inkjet head described in any one of [1] to [5], further comprising the steps of: forming a second insulating layer on the surface of the substrate from which the resist pattern has been removed; and removing a portion of the second insulating layer that covers the second opening.
[7] A method for manufacturing a flow path plate for an inkjet head described in [6], further comprising a step of forming a pressure chamber by forming a partition wall that constitutes a pressure chamber on the second insulating layer, and a step of removing the second insulating layer is performed after the step of forming the pressure chamber.
[8] The method for manufacturing a flow path plate for an inkjet head described in [7], wherein the preparing step includes preparing a substrate having an electrode film formed on a support plate, the piezoelectric body and the first insulating layer formed on the electrode film, and after the step of forming the pressure chamber, further including a step of removing the support plate from the electrode film and patterning the electrode film to form an electrode pattern, and a step of removing the second insulating layer is performed after the step of forming the electrode pattern.

In order to solve the above problems, one aspect of the present invention relates to a method for manufacturing an inkjet head as described below in [9].
[9] A method for manufacturing an inkjet head, comprising the steps of: preparing a flow path plate having partition walls forming pressure chambers, the flow path plate being manufactured by the method for manufacturing a flow path plate for an inkjet head according to [7] or [8]; and bonding a nozzle plate having nozzle holes for ejecting ink droplets to the partition walls.

In order to solve the above problems, one aspect of the present invention relates to a flow path plate for an inkjet head as set forth in [10] to [11] below.
[10] A flow path plate for an inkjet head, comprising a laminate formed by stacking a first insulating layer, a piezoelectric body, and a second insulating layer in this order, the laminate having a through hole for allowing ink to flow, a cross-sectional area of the through hole in a plane perpendicular to the ink flow direction increases toward the downstream side in the ink flow direction, and a wall surface of the through hole is convexly curved toward the inside of the through hole.
[11] The flow path plate for an inkjet head according to [10], further comprising a partition wall that constitutes a pressure chamber and is formed on the second insulating layer.

In order to solve the above problems, one aspect of the present invention relates to an inkjet head as set forth in [12] below.
[12] An inkjet head comprising: a flow path plate for an inkjet head according to [11]; and a nozzle plate having nozzle holes for ejecting ink droplets and joined to a partition wall of a pressure chamber of the flow path plate.

The present invention provides a method for manufacturing a flow path plate including a metallic diaphragm, which can form through holes with improved processing accuracy and manufacturing efficiency regardless of the type of metal, a method for manufacturing an inkjet flow path plate, an inkjet head including the flow path plate, a flow path plate, and an inkjet head including the flow path plate.

FIG. 1 is a flowchart showing a method for manufacturing an inkjet head flow path plate in this embodiment. FIG. 2 is a flowchart showing a method for manufacturing an inkjet head flow path plate in this embodiment. 3A to 3E are schematic diagrams showing a method for manufacturing a flow path plate according to this embodiment. FIG. 4 is a partial enlarged view of the portion α in FIG. 3B. FIG. 5 is a schematic cross-sectional view showing the configuration of a flow path plate for an inkjet head according to this embodiment. FIG. 6 is a schematic cross-sectional view showing the configuration of an ink-jet head according to this embodiment.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that the present invention is not limited to the following embodiments.

1. Manufacturing method of a flow path plate for an inkjet head Figures 1 and 2 are flowcharts showing a manufacturing method of a flow path plate for an inkjet head (hereinafter simply referred to as a flow path plate) in this embodiment. As shown in Figure 1, the manufacturing method of a flow path plate includes a step (step S10) of preparing a substrate on which a piezoelectric body and a first insulating layer having a first opening exposing the piezoelectric body and a second opening formed at a position different from that of the piezoelectric body are formed, a step (step S20) of forming a resist pattern covering the second opening, a step (step S30) of forming a metal film on the surface of the substrate on which the resist pattern is formed, and a step (step S40) of removing the resist pattern together with the metal film covering the resist pattern.

In this embodiment, the method for manufacturing the flow path plate includes a step (step S50) of forming a second insulating layer on the surface of the substrate from which the resist pattern has been removed, which is an optional component, and a step (step S80) of removing the portion of the second insulating layer that covers the second opening.

In addition, in this embodiment, the manufacturing method of the flow channel plate further includes a step of forming a partition wall that constitutes a pressure chamber, which is an optional component, on the second insulating layer (step S60), and a step of removing the electrode film formed on the support plate from the support plate and patterning it to form an electrode pattern (step S70). Note that in this embodiment, when the manufacturing method of the flow channel plate does not include step S60, the manufactured flow channel plate can function as a piezoelectric plate.

As mentioned above, there is a demand for a flow path plate with increased rigidity. In response to this demand, the inventors have considered increasing the thickness of the silicon dioxide diaphragm described in Patent Document 1.

However, when trying to form through-holes in a diaphragm with increased thickness by etching as in Patent Document 1, in the case of wet etching, side etching tends to progress more, making it impossible to form the through-holes in the desired shape, and reducing processing accuracy. In addition, in the case of dry etching, it takes more time to form the through-holes due to the larger thickness, reducing manufacturing efficiency.

The inventors therefore attempted to increase the rigidity of the flow path plate by forming a metallic diaphragm. While this succeeded in increasing the rigidity of the flow path plate, depending on the type of metal, the machining accuracy of the through holes and the manufacturing efficiency decreased.

This is thought to be because the solubility of metals in the etching solution differs depending on the metal. For example, metals that dissolve easily in the etching solution tend to undergo side etching more easily, which is thought to result in a decrease in the processing accuracy.

In addition, when trying to form through holes in a metal diaphragm using dry etching, the etching speed is slow, making it impossible to improve manufacturing efficiency.

After extensive research, the inventors discovered that these problems can be solved by the above-described method for manufacturing a flow path plate. Figures 3A to 3E are schematic diagrams showing the method for manufacturing a flow path plate according to this embodiment.

In the above manufacturing method, through holes for ink flow are formed by lift-off. Specifically, in a substrate 11 having a piezoelectric body 20 and a first insulating layer 30 having a first opening 31 and a second opening 32 formed on a support plate 10, a resist pattern 40 is formed to cover the second opening 32 (FIG. 3A), and a metal film 50 is formed on the surface of the substrate 11 on which the resist pattern 40 is formed (FIG. 3B). The resist pattern 40 is then removed together with the metal film 50 covering the resist pattern 40 to manufacture a flow channel plate 100 having through holes 70 (FIGS. 3C and 3E).

In the above-mentioned lift-off method, the metal film 50 is not directly etched, but the resist pattern 40 coated with the metal film 50 is removed to form the through-hole 70, which improves the processing accuracy of the through-hole regardless of the type of metal, and increases the manufacturing efficiency of the flow path plate.

1-1. Substrate preparation step (step S10)
In this process, a substrate is prepared in which a piezoelectric body is formed on a support plate, and a first insulating layer having a first opening exposing the piezoelectric body and a second opening formed in a position different from the piezoelectric body.

As shown in FIG. 2, this process may include a step of forming a piezoelectric body on a support plate (step S12) and a step of forming a first insulating layer on the support plate on which the piezoelectric body has been formed (step S13). When this process includes steps S12 and S13, a substrate on which a piezoelectric body and a first insulating layer have been formed on a support plate is prepared in steps S12 and S13. When this process does not include steps S12 and S13, a substrate on which a piezoelectric body and a first insulating layer have been formed on a support plate is prepared in advance.

When this process includes steps S12 and S13, it may further include a step (step S11) of forming an electrode film on the support plate.

1-1-1. Step of forming electrode film (step S11)
In this step, an electrode film is formed on the entire surface of the support plate.

The method for forming the electrode film is not particularly limited, but examples include sputtering and vapor deposition.

Examples of materials for the electrode film include iridium, platinum, etc.

1-1-2. Step of forming a piezoelectric body (step S12)
In this step, a piezoelectric body is formed on a support plate.

The type of the support plate is not particularly limited, and may be, for example, a silicon substrate, a magnesium oxide substrate, or a zinc oxide substrate.

The method for forming the piezoelectric body on the support plate is not particularly limited. For example, a method of forming a piezoelectric film on the surface of the support by sputtering, and then patterning the film by etching to form the piezoelectric body, or a method of bonding a prefabricated piezoelectric body onto a substrate, etc., are available. In this process, it is preferable to form the piezoelectric body on a substrate on which an electrode film has been formed.

The material contained in the piezoelectric body is not particularly limited, but is, for example, PZT (lead zirconate titanate).

In this process, the piezoelectric body may be formed on a support plate on which an electrode film of the piezoelectric body has been formed in advance. When step S10 includes step S11, in this process, the piezoelectric body is formed on the support plate on which the electrode film has been formed in step S11.

1-1-3. Step of forming first insulating layer (step S13)
The method for manufacturing a flow path plate in this embodiment may include a step of forming a first insulating layer on the support plate on which the piezoelectric body is formed in step S12.

As described above, the first insulating layer formed in this process has a first opening that exposes the piezoelectric body and a second opening formed at a position different from the piezoelectric body. In this embodiment, the second opening is formed at a position where the through hole of the flow path plate is formed. The first insulating layer can be formed, for example, by forming a resin film on the surface of a support plate on which the piezoelectric body is formed, and patterning the resin film by photolithography. At this time, the material contained in the first insulating layer may be a positive photosensitive resin composition or a negative photosensitive resin composition. Of these, a negative photosensitive resin composition is preferred.

When a positive-type photosensitive resin composition is used as the material for the first insulating layer, the insulating layer formed on the surface of the support plate is masked except for the areas where the first and second openings are to be formed, and the unmasked areas are exposed to light. The exposed areas are then dissolved using a developer to form a first insulating layer having a first and second openings.

When a negative photosensitive resin composition is used as the material for the first insulating layer, the portions of the insulating layer formed on the surface of the support plate where the first opening and the second opening are to be formed are masked, and the unmasked portions are exposed to light. The masked portions are then dissolved using a developer to form a first insulating layer having the first opening and the second opening.

The positive-type photosensitive resin composition contains a resin component and a photosensitizer. Examples of the resin component include alkali-soluble resins such as acrylic resins, epoxy resins, phenolic resins, polysiloxanes, polyimides, polyamides, and polybenzoxazoles.

Examples of the photosensitizer include quinone diazide compounds, sulfonium salts, phosphonium salts, diazonium salts, iodonium salts, etc.

The negative photosensitive resin composition contains a resin component, a photopolymerizable compound, and a photopolymerization initiator. Examples of the resin component include alkali-soluble resins such as acrylic resins, epoxy resins, phenolic resins, polysiloxanes, polyimides, polyamides, and polybenzoxazoles.

The photopolymerizable compound is preferably a radically polymerizable compound. The radically polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization. Examples of radically polymerizable compounds include unsaturated carboxylic acid esters and (meth)acrylates. Of these, (meth)acrylates are preferred.

Examples of the above (meth)acrylates include monofunctional (meth)acrylates such as isoamyl acrylate, stearyl acrylate, lauryl acrylate, and octyl acrylate, and multifunctional (meth)acrylates such as triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tri(meth)acrylate.

The (meth)acrylate may be, for example, an alkylene oxide such as ethylene oxide (EO) or propylene oxide (PO), or may be modified with caprolactone (modified (meth)acrylate).

The photopolymerization initiator is preferably a radical polymerization initiator. Examples of radical polymerization initiators include intramolecular bond cleavage type radical polymerization initiators and intramolecular hydrogen abstraction type radical polymerization initiators.

Examples of intramolecular bond cleavage type radical polymerization initiators include acetophenone-based initiators such as diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, and 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, benzoin-based initiators such as benzoin and benzoin methyl ether, and acylphosphine oxide-based initiators such as 2,4,6-trimethylbenzoindiphenylphosphine oxide.

Examples of intramolecular hydrogen abstraction type radical polymerization initiators include benzophenone-based initiators such as benzophenone, o-benzoylmethylbenzoate, and 4-phenylbenzophenone, thioxanthone-based initiators such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone, and aminobenzophenone-based initiators such as 4,4'-diethylaminobenzophenone, etc.

Examples of the developer include organic alkaline aqueous solutions such as tetramethylammonium hydroxide (TMAH) aqueous solution and choline aqueous solution, and inorganic alkaline aqueous solutions such as potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, potassium carbonate aqueous solution, sodium carbonate aqueous solution, and lithium carbonate aqueous solution.

The light source used for the above exposure is preferably ultraviolet light.

The thickness of the first insulating layer formed in this process is not particularly limited, but is preferably 1 μm or more and 5 μm or less, and more preferably 2 μm or more and 4 μm or less.

In this process, the first insulating layer may be heated and hardened. This makes it easier for the ends of the first opening and the second opening to curve. The formation of the above-mentioned curvature makes it easier to remove the resist pattern in the process of removing the resist pattern, which will be described later.

In this process, the actinic radiation curable ink that is the material for the first insulating layer may be applied to the support plate and cured to form the first insulating layer.

1-2. Step of forming a resist pattern (step S20)
In this step, a resist pattern is formed to cover the second opening of the first insulating layer.

Specifically, after applying resist to the substrate surface prepared in step S10, a photomask is used to expose the resist so that a resist pattern is formed in the second opening, and the resist pattern is formed using a developer. This makes it possible to form a resist pattern that covers only the second opening.

The resist pattern that is formed covers almost the entire second opening, but may also cover only a small portion of the first insulating layer near the second opening, or may be slightly smaller than the second opening.

The resist pattern may be formed using a positive-type photosensitive resin composition or a negative-type photosensitive resin composition, but it is preferable to form it using a positive-type photosensitive resin, which has excellent pattern accuracy.

The positive-type photosensitive resin composition and negative-type photosensitive resin composition that can be used in this process can be any known resin composition used as a lift-off resist.

In the process of forming the metal film described below, the greater the difference between the thickness of the metal film and the thickness of the resist pattern, the more likely it is that a shadow of the resist pattern (a fine gap between the resist pattern and the first insulating layer) will be formed. Because the metal film is less likely to penetrate into this shadowed area, the base portion of the resist pattern is less likely to be covered with the metal film. As a result, in the process of removing the resist pattern described below, the stripping solution will more easily penetrate into the bottom of the resist pattern, making it easier to remove the resist pattern. The thickness of the resist pattern can be, for example, at least twice the thickness of the metal film.

1-3. Step of forming metal film (step S30)
In this step, a metal film is formed on the surface of the substrate on which the resist pattern was formed in step S20. Specifically, a metal film is formed so as to cover all of the first insulating layer, the piezoelectric body, and the resist pattern.

The metal film formed in this process can function as a diaphragm in an inkjet head.

Examples of methods for forming the metal film include vapor deposition and sputtering. Examples of metals that can be used to form the metal film include tungsten, molybdenum, chromium, titanium, nickel, iridium, platinum, copper, gold, and alloys thereof. Of these, tungsten, molybdenum, chromium, nickel, iridium, platinum, and alloys thereof are preferred from the viewpoint of increasing the rigidity of the metal film. Furthermore, copper and gold have excellent electrical conductivity, so metal films (diaphragms) made of these materials can also function as electrodes for piezoelectric bodies.

In this process, it is preferable to form the metal film as a laminate of multiple layers with different metal compositions. This makes it possible to, for example, stack a layer made of a metal that can increase rigidity and a layer made of a metal with low electrical resistivity, thereby increasing the rigidity of the metal film while allowing the metal film to function as an electrode for the piezoelectric body. From this perspective, it is preferable to form the metal film as a laminate including two or more metal layers with different compositions, made of a metal selected from the group consisting of tungsten, molybdenum, chromium, titanium, nickel, iridium, platinum, copper, gold, and alloys thereof.

Conventionally, when a laminate of multiple layers with different metal compositions is formed as a metal film, when the formed metal film is used as a diaphragm, the diaphragm is exposed to ink, which easily causes galvanic corrosion. In contrast, in this embodiment, the process of forming the second insulating layer described below causes the second insulating layer to cover the metal film (diaphragm), making the metal film (diaphragm) less likely to be exposed to ink and less likely to cause galvanic corrosion.

In addition, in this process, it is preferable to form a metal film having a Young's modulus of 150 GPa or more and 250 GPa or less. When a laminate of multiple layers is formed as the metal film, the Young's modulus refers to the Young's modulus value of the laminate. If the Young's modulus is 150 GPa or more, the rigidity of the metal film can be increased. If the Young's modulus is 250 GPa or less, the metal film (vibration plate) is more likely to deform in response to the deformation of the piezoelectric body. This makes it easier to cause a change in volume of the pressure chamber, making it easier to eject ink. The Young's modulus can be measured by a vibrating reed method. A metal film having a Young's modulus in the above range can be formed by appropriately selecting and adjusting the material and film thickness of the metal film.

The thickness of the metal film formed in this process can be, for example, 1 μm or more and 8 μm or less, and preferably 3 μm or more and 6 μm or less.

1-4. Step of removing resist pattern (step S40)
In this step, the resist pattern is removed together with the metal film covering the resist pattern. Specifically, this step is performed using a stripping solution for removing the resist pattern.

Figure 4 is a partial enlarged view of the α portion in Figure 3B. In step S30, the shadow of the resist pattern 40 is easily formed, so that it is difficult to completely cover the gap 32a between the resist pattern 40 and the first insulating layer 30 with the metal film 50. Therefore, the stripping solution can be permeated from the gap 32a, so that the resist pattern 40 can be removed together with the metal film 50 covering the resist pattern 40. In this step, for example, even if the resist pattern 40 remains slightly on the first insulating layer 30 and there is a boundary between the resist pattern 40 and the first insulating layer 30, the resist pattern 40 can be removed together with the metal film 50 covering the resist pattern 40.

In this process, the resist pattern can be removed, for example, by immersing the substrate in a stripping solution or by injecting the stripping solution into the gap.

Examples of stripping solutions include N-methylpyrrolidone (NMP) and acetone.

1-5. Step of forming second insulating layer (step S50)
In this embodiment, the method for manufacturing a flow path plate may include a step of forming a second insulating layer (see FIG. 3D ). As shown in FIG. 3D , in this step, a second insulating layer 60 is formed on the surface of the substrate 11 from which the resist pattern 40 has been removed in step S40. Specifically, a metal film 50 that covers the piezoelectric body 20 and the first insulating layer 30 (other than the second opening 32), and a second insulating layer 60 that covers the second opening 32 of the first insulating layer 30 are formed.

The process of forming the second insulating layer allows the formation of a second insulating layer that covers the metal film, thereby suppressing corrosion of the metal film (diaphragm) caused by exposure to ink or air. In addition, when a laminate of multiple layers with different metal compositions is formed as the metal film in step S30, this process can suppress bimetallic corrosion of the metal film (diaphragm), as described above.

Examples of materials for the second insulating layer include silicon compounds such as silica, silicon nitride, and silicon carbide, polyimide resin, and parylene resin. Of these, silicon carbide and polyimide resin are preferred.

The method for forming the second insulating layer is not particularly limited, but the second insulating layer can be formed by sputtering, CVD, or spin coating.

In this process, it is preferable to form a second insulating layer having a thickness of 1 μm or more and 5 μm or less, and it is more preferable to form a second insulating layer having a thickness of 2 μm or more and 4 μm or less.

1-6. Step of forming partition walls (step S60)
In this embodiment, the method for manufacturing the flow path plate may include a step of forming partition walls that constitute the pressure chambers on the second insulating layer.

The pressure chamber applies pressure to the ink by deformation of the piezoelectric body and the diaphragm. Therefore, in this process, a partition is formed so that the pressure chamber can be formed on the second insulating layer that covers the piezoelectric body.

The method for forming the partition wall is not particularly limited, but for example, the partition wall can be formed on the second insulating layer by joining a previously prepared partition wall to the second insulating layer or by electroplating (electroforming).

1-7. Step of forming electrode pattern (step S70)
In this embodiment, when preparing a substrate having an electrode film, a piezoelectric body, and a first insulating layer formed on a support plate in step S10, a step of removing the support plate from the electrode film and patterning the electrode film to form an electrode pattern may be included. This step is performed after step S60. The electrode pattern includes an electrode electrically connected to the piezoelectric body and a wiring pattern electrically connected to the electrode.

The method for patterning the electrode film is not particularly limited, but examples include dry etching and wet etching.

After the electrode pattern is formed, a process of forming a protective film that covers the electrode pattern may be performed. Examples of materials for the protective film include polyimide, etc. From the viewpoint of making it easier to remove only the second insulating layer that covers the second opening in the process of removing the second insulating layer that covers the second opening, which will be described later, it is preferable to form a protective film that exposes the second opening and then remove only the portion of the protective film that covers the second opening.

The protective film can be formed, for example, by a spin coating method.

1-8. Step of removing the second insulating layer (step S80)
In this embodiment, when the method for manufacturing a flow path plate includes a step of forming a second insulating layer (step S50), the manufacturing method includes a step of removing the second insulating layer (see FIG. 3E ). As shown in FIG. 3E , in this step, a portion 61 of the second insulating layer 60 formed in step S50 that covers the second opening 32 is removed.

In this process, by removing the second insulating layer that covers the second opening, a through hole (flow path) for the flow of ink can be formed in the laminate of the first insulating layer, the metal film (vibration plate), and the second insulating layer.

Examples of methods for removing the second insulating layer covering the second opening include dry etching, wet etching, laser processing, and the like. Of these, dry etching is preferred.

This step may be performed after the step of forming the second insulating layer (step S50), but when the method for manufacturing a flow channel plate in this embodiment includes a step of forming a partition wall (step S60), this step is preferably performed after step S60. Also, when the method for manufacturing a flow channel plate in this embodiment includes a step of patterning the electrode film (step S70), this step is preferably performed after step S70.

By carrying out this step after step S60, it is possible to suppress adhesion of foreign matter inside the through-hole during the formation of the partition wall. In addition, if an electrode film is formed on the support plate, by carrying out this step after step S70, for example, the electrode film located at the second opening can be removed and patterned in advance in step S70, so that the through-hole can be formed by simply removing the second insulating layer covering the second opening in this step. Therefore, it is possible to further shorten the processing time for the through-hole, improve manufacturing efficiency, and further increase processing accuracy.

2. Manufacturing Method of Inkjet Head A manufacturing method of an inkjet head according to this embodiment includes the steps of: preparing a flow path plate having partition walls that form pressure chambers, which is manufactured by the above-described manufacturing method of a flow path plate; and bonding a nozzle plate having nozzle holes for ejecting ink droplets to the partition walls of the prepared flow path plate.

2-1. Step of Preparing a Flow Channel Plate In this step, a flow channel plate having partition walls that form pressure chambers and manufactured by the above-mentioned method of manufacturing a flow channel plate is prepared.

In this step, a nozzle plate having nozzle holes for ejecting ink droplets is bonded to the partition walls constituting the pressure chambers of the flow path plate prepared in the preparation step, at a position where the nozzle holes communicate with the pressure chambers. More specifically, the nozzle plate is aligned so that the nozzle holes are located directly below the piezoelectric body, and then the nozzle plate is bonded to the partition walls.

The method for joining the above is not particularly limited, but may be, for example, a method of joining using an adhesive.

In this embodiment, the method for manufacturing the inkjet head may further include a step of bonding a common ink chamber forming member having a common ink chamber to the surface of the flow path plate facing the first insulating layer.

3. Flow Channel Plate Fig. 5 is a schematic cross-sectional view showing the configuration of a flow channel plate 100 for an inkjet head according to this embodiment. As shown in Fig. 5, the flow channel plate has a laminate 110 formed by laminating a piezoelectric body 111, a first insulating layer 112, a vibration plate 113, and a second insulating layer 114. The flow channel plate can be manufactured by the above-mentioned flow channel plate manufacturing method.

The laminate has through holes 115 for allowing ink to flow. The cross-sectional area of the through holes 115 in a plane perpendicular to the ink flow direction (the direction of the arrow X in FIG. 5) increases toward the downstream side of the ink flow direction. Furthermore, the wall surface of the through holes 115 is curved in a convex shape toward the inside of the through holes 115.

The through holes 115 are formed at the same positions in the first insulating layer 112, the vibration plate 113, and the second insulating layer 114 in the laminate 110. In other words, the through holes 115 are holes that are pierced so that the flow direction of the ink is perpendicular to the horizontal plane.

By forming a laminate of the first insulating layer and the vibration plate (metal film) having a second opening whose wall surface is curved as described above using the above-mentioned method of manufacturing the flow path plate, the through hole 115 has the above-mentioned shape. And, by having the through hole 115 have the above-mentioned shape, it is possible to suppress the adhesion of air bubbles in the ink.

The type of material and thickness of the piezoelectric body 111 can be the same as that described in the manufacturing method of the flow path plate.

The type and thickness of the material of the first insulating layer 112 can be the same as those described in the manufacturing method of the flow path plate.

The material and thickness of the vibration plate 113 can be the same as the material and thickness of the metal film in the manufacturing method of the flow path plate.

The type and thickness of the material of the second insulating layer 114 can be the same as those described in the manufacturing method of the flow path plate.

In this embodiment, the flow path plate 100 may further include a partition 120 that constitutes a pressure chamber and is formed on the second insulating layer 114. The flow path plate 100 may further include an electrode 130 formed on the surface of the piezoelectric body 111 opposite to the surface on which the vibration plate 113 is laminated, and a wiring pattern 140 formed on the opposite surface. The wiring pattern 140 is electrically connected to the electrode 130.

The flow path plate 100 may further have a protective film (not shown) that covers the electrodes 130 and the wiring pattern 140.

6 is a schematic cross-sectional view showing the configuration of an inkjet head 200 according to this embodiment. As shown in Fig. 6, the inkjet head 200 has a flow path plate 100 having a partition wall 120 that forms a pressure chamber, and a nozzle plate 210 joined to the partition wall 120.

The nozzle plate 210 has a nozzle hole 211 for ejecting ink droplets, and is joined to the partition wall 120 at a position where the nozzle hole 211 communicates with a pressure chamber 121 formed by the partition wall 120. The cross-sectional shape of the nozzle hole 211 is, for example, circular. From the viewpoint of improving the ejection stability of the ink, it is preferable that the nozzle hole 211 has a tapered shape.

In this embodiment, the inkjet head 200 may further include a common ink chamber forming member 220 for forming a common ink chamber 221, which is bonded to the surface of the flow path plate 100 on the side of the first insulating layer 112.

By using the method for manufacturing a flow path plate for an inkjet head of the present invention, it is possible to form through holes with improved processing accuracy and manufacturing efficiency regardless of the type of metal, and to suppress corrosion of the diaphragm. Therefore, the present invention is useful as a method for manufacturing a nozzle plate for an inkjet head that uses a metallic diaphragm.

REFERENCE SIGNS LIST 10 Support plate 11 Substrate 20, 111 Piezoelectric body 30, 112 First insulating layer 40 Resist pattern 50 Metal film 60, 114 Second insulating layer 70, 115 Through hole 100 Flow path plate 110 Laminated body 120 Partition wall 200 Inkjet head 210 Nozzle plate 220 Common ink chamber forming member

Claims (12)

A step of preparing a substrate on a support plate, the substrate including a piezoelectric body and a first insulating layer having a first opening exposing the piezoelectric body and a second opening formed at a position different from that of the piezoelectric body;
forming a resist pattern covering the second opening;
forming a metal film on the surface of the substrate on which the resist pattern is formed;
removing the resist pattern together with a metal film covering the resist pattern;
having
A method for manufacturing a flow path plate for an inkjet head. In the step of forming the metal film, a laminate of multiple layers having different metal compositions is formed as the metal film.
The method for manufacturing the flow path plate for an ink jet head according to claim 1 . In the step of forming the metal film, a laminate of a plurality of metal layers is formed,
The laminate includes two or more metal layers each made of a metal selected from the group consisting of tungsten, molybdenum, chromium, titanium, nickel, iridium, platinum, copper, gold, and alloys thereof, and each having a different composition.
The method for manufacturing the flow path plate for an ink jet head according to claim 2 . The method for manufacturing a flow path plate for an inkjet head according to claim 1, wherein the metal film forming step forms a metal film having a Young's modulus of 150 GPa or more and 250 GPa or less. The preparing step includes:
forming a piezoelectric body on a support plate;
forming a first insulating layer on the support plate on which the piezoelectric body is formed;
The method for manufacturing the flow path plate for an ink jet head according to claim 1 . forming a second insulating layer on the surface of the substrate from which the resist pattern has been removed;
removing a portion of the second insulating layer that covers the second opening;
The method for manufacturing a flow path plate for an ink jet head according to claim 1 , further comprising: The method further includes a step of forming a partition wall that constitutes a pressure chamber on the second insulating layer,
The step of removing the second insulating layer is performed after the step of forming the partition wall.
The method for manufacturing a flow path plate for an ink jet head according to claim 6. In the preparing step, a substrate is prepared in which an electrode film is formed on a support plate, and the piezoelectric body and the first insulating layer are formed on the electrode film;
After the step of forming the partition wall,
The method further includes a step of removing the support plate from the electrode film and patterning the electrode film to form an electrode pattern;
The step of removing the second insulating layer is performed after the step of forming the electrode pattern.
The method for manufacturing a flow path plate for an ink jet head according to claim 7. a step of preparing a flow path plate having a partition wall, the flow path plate being manufactured by the method for manufacturing a flow path plate for an inkjet head according to claim 7 or 8;
A method for manufacturing an inkjet head, comprising: bonding a nozzle plate having nozzle holes for ejecting ink droplets to the partition walls of the prepared flow path plate. A laminate including a piezoelectric body, a first insulating layer, a vibration plate, and a second insulating layer,
the laminate has through holes for allowing ink to flow therethrough;
a cross-sectional area of the through hole in a plane perpendicular to a flow direction of the ink increases toward a downstream side in the flow direction,
The wall surface of the through hole is curved convexly toward the inside of the through hole.
A flow path plate for inkjet heads. The flow path plate for an inkjet head according to claim 10, further comprising a partition wall that constitutes a pressure chamber and is formed on the second insulating layer. A flow path plate for an inkjet head according to claim 11;
a nozzle plate having nozzle holes for ejecting ink droplets and joined to partition walls constituting pressure chambers of the flow path plate;
An inkjet head comprising: