Ink jet head and method for producing same

Inkjet head and its manufacturing method

Technical field

The present invention relates to an improvement of an ink jet type recording head. In particular, it relates to the provision of an inkjet recording head capable of high-definition by providing a manufacturing method that does not deteriorate the yield during manufacturing even if a pressure chamber substrate thinner than conventional products is used.

Background technique

The conventional inkjet recording head includes a pressure chamber substrate, a nozzle plate adhered to one side of the pressure chamber substrate, and a vibration plate provided on the other side of the pressure chamber substrate. The pressure chamber substrate is composed of a plurality of pressure chambers for storing ink formed on a silicon wafer, and a nozzle plate is bonded to each pressure chamber (cavity) to arrange nozzle holes. A piezoelectric element is formed on the opposite side of the pressure chamber of the vibration plate. In this structure, the pressure chamber is filled with ink, and if a voltage is applied to the piezoelectric element, the piezoelectric body changes in volume, and the volume changes in the pressure chamber. Using this pressure change, ink is ejected from the nozzle hole. In the prior art, the thickness of the silicon wafer and the height of the pressure chamber are set substantially the same.

However, in recent years, there has been an increasing demand for high-definition inkjet recording heads. In order to increase the definition of inkjet recording heads, the width and height of the pressure chambers and the thickness of the side walls separating the pressure chambers must be reduced.

However, the thickness of the silicon wafer that can be used now is about 200 μm, and this thickness defines the height separating the side walls of the pressure chamber. If the thickness of the silicon wafer is thinner than this thickness, the mechanical strength of the silicon wafer cannot be guaranteed, and there are usage problems such as breakage of the silicon wafer during the pressure chamber formation process.

It can be considered that the thin pressure chamber substrate of this thickness is formed separately from the piezoelectric element, another base is used in the formation of the piezoelectric element, and the pressure chamber substrate and the piezoelectric element are finally bonded together. In this way, there is no need to flow the pressure chamber substrate in the multiple processes for forming the piezoelectric element, and the disadvantage of using a thin pressure chamber substrate can be eliminated.

However, since the height of the piezoelectric element is only a few μm, after the piezoelectric element is formed, it cannot affect the piezoelectric element, and it is difficult to peel the piezoelectric element from the base.

Summary of the invention

In view of the above-mentioned problems, the first task of the present invention is to provide an inkjet recording head corresponding to high definition by arranging a thin pressure chamber substrate.

The second problem of the present invention is to provide a method for manufacturing an inkjet recording head that can improve the yield in manufacturing and can achieve cost reduction by forming a pressure chamber substrate with a thin thickness in a process different from that of the piezoelectric element.

The third subject of the present invention is to provide an inkjet recording head that can be manufactured at a lower cost by reliably peeling a piezoelectric element formed by a process different from that of the pressure chamber substrate from the base, thereby improving the yield in manufacturing and realizing cost reduction method.

The invention that solves the above-mentioned first problem is composed of an inkjet recording head having a structure capable of ejecting ink by applying a voltage to a piezoelectric element, and it includes: (a) a pressure chamber substrate forming a belt A pressure chamber structure with nozzles that can eject ink, so that the nozzles open in the same direction; (b) The common electrode film is formed on a side of the pressure chamber substrate that is different from the surface where the nozzles are installed, so as to seal the pressure chambers; ( c) Piezoelectric elements, including piezoelectric films and upper electrodes, are respectively formed at positions corresponding to the pressure chambers on the common electrode film; and (d) The accumulator part is equipped with more than one pressure chamber inside. The cover-like structure of the electrical component, and the ink reservoir is formed inside it.

The inkjet recording head of the present invention has a structure in which the nozzle and the pressure chamber are formed integrally with the same component.

The invention to solve the above-mentioned second and third problems is an inkjet recording head that ejects ink from nozzles provided in a pressure chamber by applying a voltage to a piezoelectric element to change the volume. The manufacturing method consists of: (a) forming a peeling layer that can be peeled off by light irradiation on a light-transmitting base; (b) forming a common electrode film on the peeling layer Common electrode film forming process; (c) Piezoelectric element forming process of forming a plurality of piezoelectric elements on the common electrode film; (d) Accumulator forming process of forming accumulator part, the accumulator part Equipped with a cover-like structure with more than one piezoelectric element inside, and an ink reservoir is formed inside; (e) By irradiating a predetermined light on the peeling layer from the base side, peeling occurs on the peeling layer , A peeling process of peeling the base; and (f) bonding a pressure chamber substrate with a plurality of pressure chambers on the common electrode film from which the base is peeled, so as to seal each pressure chamber.

The invention that solves the above-mentioned second and third problems is an inkjet recording head that can eject ink from nozzles provided in a pressure chamber by applying a voltage to a piezoelectric element to change the volume. The manufacturing method consists of: (a) forming a peeling layer forming process that can be peeled off by light irradiation on a first base with light transmission; (b) forming a common peeling layer on the peeling layer The common electrode film forming process of the electrode film; (c) The piezoelectric element forming process of forming a plurality of piezoelectric elements on the common electrode film; (d) The piezoelectric element is formed on the surface of the piezoelectric element by bonding with an adhesive layer. The bonding process of connecting the second base; (e) The first peeling process of peeling off the first base by irradiating predetermined light on the peeling layer from the side of the first base to produce peeling on the peeling layer; (f) On the common electrode film where the first base is peeled off, a pressure chamber substrate with a plurality of pressure chambers is bonded to seal each pressure chamber; and (g) a second peeling process of peeling off the second base.

The present invention is equipped with an intermediate layer forming process that also forms an intermediate layer between the peeling layer and the common electrode film.

According to the present invention, the piezoelectric body element forming process includes: a process of laminating a piezoelectric body layer on a common electrode film, a process of forming an upper electrode film on the piezoelectric body layer, and etching the laminated piezoelectric body layer and the upper electrode film The process of forming piezoelectric elements.

According to the present invention, any one of amorphous silicon, oxide ceramics, nitride ceramics, organic polymer materials, or metals is used to form the peeling layer.

According to the present invention, the pressure chamber substrate is manufactured by a process of forming a resin layer in a mold, a process of peeling the resin layer from the mold, and a process of providing a hole corresponding to a nozzle in the resin layer.

According to the present invention, the second peeling process causes peeling at the interface between the piezoelectric element and the common electrode film and the adhesive layer.

According to the present invention, the second peeling process produces peeling in the adhesive layer.

According to the present invention, the adhesive layer is made of a material containing a substance curable by additional energy.

According to the present invention, the adhesive layer is composed of a thermoplastic resin.

According to the present invention, an intermediate layer forming process for forming an intermediate layer between the adhesive layer and the second base is also provided.

According to the present invention, the intermediate layer is composed of a material containing more than one metal selected from Ni, Cr, Ti, Al, Cu, Ag, Au, or Pt. In the second peeling process, the intermediate layer and the adhesive layer Peeling occurs on the interface.

According to the present invention, the intermediate layer is composed of either porous silicon or an anodic oxide film. In the second peeling process, peeling occurs in the intermediate layer or at the interface between the intermediate layer and the second base.

According to the present invention, any one of amorphous silicon, oxide ceramics, nitride ceramics, organic polymer materials or metals is used to form the intermediate layer. In the second peeling process, the predetermined light is removed from the second base side. Irradiation on the intermediate layer causes peeling in the intermediate layer.

Description of the drawings

Fig. 1 is a perspective view of the inkjet printer of the present invention.

Fig. 2 is a perspective view and a partial cross-sectional view of the main part of the ink jet recording head of the present invention.

3 is a cross-sectional view of the manufacturing process of the ink jet recording head of Example 1. FIG. FIG. 3A shows the peeling layer forming process, FIG. 3B shows the common electrode film forming process, FIG. 3C shows the piezoelectric element forming process, and FIG. 3D shows the etching process.

4 shows a cross-sectional view of the manufacturing process of the ink jet recording head of Example 1. FIG. Fig. 4E shows the accumulator forming process, Fig. 4F shows the peeling process, Fig. 4G shows the bonding process, and Fig. 4D shows the completed cross-sectional view.

Fig. 5 shows a cross-sectional view of the manufacturing process of the pressure chamber substrate. Fig. 5A shows a master disk manufacturing process, Fig. 5B shows a substrate forming process, Fig. 5C shows a peeling process, and Fig. 5D shows a nozzle forming process.

FIG. 6 shows a cross-sectional view of the manufacturing process of the ink jet recording head of Example 2. FIG. Fig. 6A shows the piezoelectric element forming process, Fig. 6B shows the etching process, Fig. 6C shows the bonding process, and Fig. 6D shows the first peeling process.

FIG. 7 shows a cross-sectional view of the manufacturing process of the ink jet recording head of Example 2. FIG. Fig. 7E shows the bonding process, Fig. 7F shows the second peeling process, Fig. 7G shows the cleaning process, and Fig. 7H shows the accumulator forming process.

FIG. 8 shows a modification of the second peeling process.

FIG. 9 shows a cross-sectional view of the manufacturing process of the ink jet recording head of the third embodiment. FIG. 9A shows the intermediate layer forming process and the bonding process, and FIG. 9B shows the second peeling process.

detailed description

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<Example 1>

The first embodiment relates to an inkjet recording head in which a piezoelectric element is formed on a base, a stocker member is formed thereon, the piezoelectric element is peeled from the base, and the inkjet recording head is bonded to a separately manufactured integrated pressure chamber substrate.Manufacturing method. Manufacturing method.

(Structure of Inkjet Recording Head) FIG. 1 is a perspective view of an inkjet printer incorporating an inkjet recording head manufactured according to the manufacturing method of this embodiment. As shown in FIG. 1, the inkjet printer 100 of this embodiment is composed of: the inkjet recording head 101, the carriage 103, and the like of the present invention are provided on the main body 102. The printing paper 105 is mounted on the carriage 103. If the printing data is supplied from a computer not shown in the figure, the internal roller not shown in the figure introduces the printing paper 105 into the main body 102. When the printing paper 105 passes near the rollers, the inkjet recording head 101 is driven in the direction of the arrow in FIG. 1 to perform printing. The printing paper 105 after printing is discharged from the discharge port 104.

Fig. 2 shows a perspective view of the main part of the ink jet recording head described above. For easy understanding, a partial cross-sectional view is shown. Only the outline of the structure will be described here, and the detailed manufacturing method will be described below. As shown in FIG. 2, the main part of the inkjet recording head is composed of a common electrode film 3 in which piezoelectric elements 4 are bonded and formed on an integrally formed pressure chamber substrate 2. Note that the stocker member 5 formed to cover the common electrode film is omitted in FIG. 2 (refer to FIG. 3).

By etching a single crystal silicon substrate or the like, the pressure chamber substrate 2 can be provided with a plurality of cavities 21 having the function of each pressure chamber. The cavities 21 are separated by side walls 22. Each cavity 21 is connected to a common flow path 23 through a supply port 24. On the other surface of the partition cavity 21, a nozzle 25 is provided. The common electrode film 3 is made of, for example, platinum or the like, and the piezoelectric element 4 is formed at a position corresponding to the cavity 21 on the common electrode film 3. In the common electrode film 3, an ink port 33 is provided with respect to a part of the common flow path 23.

The piezoelectric element 4 is formed by laminating a piezoelectric thin film formed of, for example, PZT or the like and an upper electrode.

Furthermore, the output terminal of the drive circuit not shown in the figure and the upper electrode of each piezoelectric element 4 are connected, and the ground terminal of the drive circuit and the common electrode film 3 are connected.

In the structure of the inkjet recording head described above, if the drive circuit is driven to apply a predetermined voltage to the piezoelectric element 4, a volume change is generated on the piezoelectric element 4, and the ink pressure in the cavity 21 is increased. If the ink pressure increases, ink droplets are ejected from the nozzle 25.

(Method of Manufacturing Inkjet Recording Head) With reference to FIGS. 3 to 5, the method of manufacturing the inkjet recording head of the present invention will be described. These figures are cross-sectional views of the manufacturing process of the ink jet recording head, showing the cutting conditions in the width direction of the cavity.

Peeling layer forming process (FIG. 3A ): A peeling layer forming process in which a peeling layer 11 for peeling the piezoelectric element and the common electrode film is formed on the first base 10 as a dummy substrate for forming the piezoelectric element.

(First base) As the first base 10, there is a translucent base that transmits irradiated light, and it is preferable to use a base having heat resistance and corrosion resistance in the piezoelectric element forming process. The transmittance of the irradiated light is preferably 10% or more, more preferably 50% or more. If the transmittance is too low, the attenuation of the irradiated light becomes large, which requires more energy than peeling off the peeling layer.

As for the corrosion resistance, since it reaches 400°C to 900°C or higher during the forming process, it is preferable to have the property of resistance to such a temperature. If the base has good heat resistance, the temperature can be set freely in the formation conditions of the piezoelectric element.

When the maximum temperature at which the piezoelectric element as the layer to be copied is formed is Tmax, the base is preferably made of a material having a stress point above Tmax. Specifically, the stress point is preferably 350°C or higher, and more preferably 500°C or higher. Examples of such materials include heat-resistant glass such as quartz glass, soda lime glass, Corning glass (Corning 7059), and Nippon Electric Glass OA-2. Especially the heat resistance of quartz glass is very good. The stress point of quartz glass is 1000°C compared to the 400°C to 600°C stress point of normal glass.

The thickness of the base does not have a large limiting factor, but the thickness is preferably about 0.1 mm to 0.5 mm, and more preferably 0.5 mm to 1.5 mm. If the thickness of the substrate is too thin, the strength will decrease. On the contrary, if it is too thick, the irradiated light will attenuate if the transmittance of the base is low. However, when the transmittance of the light irradiated from the base is high, the upper limit may be exceeded and the thickness may be increased.

In addition, in order to uniformly transmit the irradiated light to the peeling layer, the thickness of the base is preferably uniform.

(Peeling layer) The peeling layer 11 is a layer in which peeling occurs in the layer or at the interface (also referred to as "in-layer peeling" or "interface peeling") by irradiating light such as laser light. That is, in the release layer, irradiation with a certain intensity of light causes the atoms or molecules of the constituent substance to disappear or reduce the bonding force between atoms or molecules, causing detachment, etc., resulting in detachment. In addition, by the irradiation of the irradiated light, gas may be released from the peeling layer and peeling may occur. There are cases where the components contained in the release layer become gas and release to achieve release, and there are cases where the release layer becomes gas by absorbing light and releases its vapor to achieve release.

As the composition of this release layer, there are the following considerations.

1) Amorphous silicon (a-Si)

The amorphous silicon preferably contains H (hydrogen). The hydrogen content is preferably about 2 at% or more, more preferably 2 to 20 at%. If hydrogen is contained, hydrogen is released by light irradiation, and internal pressure is generated in the peeling layer, and this internal pressure can promote peeling. The hydrogen content is adjusted according to the film forming conditions. For example, in the case of using the CVD method, the gas composition can be adjusted by appropriately setting conditions such as gas pressure, gas environment, gas atmosphere, gas flow rate, gas temperature, substrate temperature, and incident light power.

2) Various oxide ceramics, dielectrics or semiconductors such as silicon oxide or silicon oxide, titanium oxide or titanium oxide, zirconium oxide or zirconium oxide, lanthanum oxide or lanthanum oxide, etc. As silicon oxide, SiO, SiO2, Si3O2. Examples of silicon oxides include K2Si3, Li2SiO3, CaSiO3, ZrSiO4, and Na2SO3.

Examples of titanium oxide include TiO, Ti2O3, and TiO2. Examples of titanium oxides include BaTiO4, BaTiO3, Ba2Ti9O20, BaTi5O11, CaTiO3, SrTiO3, PbTi3, MgTiO3, ZrTi2, SnTiO4, Al2Ti5, and FeTiO3.

As zirconium oxide, ZrO2 can be mentioned. Examples of zirconium oxides include BaZrO3, ZrSiO4, PbZrO3, MgZrO3, and K2ZrO3.

3) Nitride ceramics such as silicon nitride, aluminum nitride, titanium nitride, etc. 4) Organic polymer materials, as organic polymer materials, include -CH2-, -CO- (ketone), -CONH- (amide), -NH -(Imine), -COO-(ester), -N=N-(azo), -CH=N-() and other bonds (the bond between these atoms can be cut by light irradiation), if There are a lot of such keys, and other compositions are also possible.

In addition, the organic polymer material may be a material having aromatic hydrocarbons (1 or more benzene rings or fused rings thereof) in the structural formula. Specific examples of such organic polymer materials include polyolefins such as polyethylene and polypropylene, polyimides, polyamides, polyesters, polymethylmethacrylate (PMMA), and polyphenylene sulfide. Ether (PPS), polyethyl ether sulfonate (PES), epoxy resin, etc.

5) Metals Examples of metals include Al, Li, Ti, Mn, In, Sn, Y, La, Ce, Nd, Pr, Gd, or Sm, or alloys containing at least one of these metals.

(Thickness of the peeling layer) The thickness of the peeling layer is generally preferably about 1 nm to 20 μm, more preferably about 10 nm to 2 μm, and most preferably about 40 nm to 1 μm. If the thickness of the peeling layer is too thin, the thickness of the formed film will be detrimental to the uniformity of peeling, and if the thickness of the peeling layer is too thick, the necessary irradiated light power (light quantity) must be increased during peeling. In addition, it takes time to remove residues of the peeling layer remaining after peeling.

(Formation method) The method for forming the release layer is preferably a method capable of forming the release layer with a uniform thickness, and can be appropriately selected according to various conditions such as the composition and thickness of the release layer. For example, CVD (including MOCVD, low pressure CVD, ECR-CVD) method, vapor deposition, molecular beam vapor deposition (MB), sputtering method, ion fretting method, PVD method and other vapor phase film forming methods can be used. Various plating methods such as electroplating, immersion plating (flip), electroless plating, Langmuir blowjet (LB), spin coating, spray coating, roller coating and other coating methods, various printing methods, ink Spraying method, powder spraying method, etc. Among these methods, it is best to combine two or more methods.

Especially when the composition of the release layer is amorphous silicon (a-Si), it is better to form the film by CVD, especially low-pressure CVD and plasma CVD. In addition, in the case of using ceramics to form the release layer according to the sol-gel method and the case where the release layer is formed of an organic polymer material, it is preferable to form the film according to the coating method, especially spin coating.

(Regarding the intermediate layer) Although not shown in the figure, it is preferable to form an intermediate layer between the peeling layer 11 and the common electrode film 3. The intermediate layer functions as a protective layer and an insulating layer that physically or chemically protect the copied layer during manufacture or use, a barrier layer that prevents the transfer (migration) of components to or from the copied layer, and a reflective layer. At least one of the layers.

The composition of the intermediate layer can be appropriately selected according to the purpose. For example, in the case of an intermediate layer formed between a peeling layer made of amorphous silicon and a layer to be copied, silicon oxide such as SiO2 can be cited. In addition, as the composition of other intermediate layers, for example, Pt, Au, W, Ta, Mo, Al, Cr, Ti, or alloys containing these metals as main components can be cited.

The thickness of the intermediate layer can be appropriately determined according to the purpose of its formation. Generally, the thickness is preferably about 10 nm to 5 μm, and more preferably about 40 nm to 1 μm.

As a method of forming the intermediate layer, various methods described in the above-mentioned peeling layer can be used. In addition to forming the intermediate layer as one layer, multiple materials of the same or different compositions can also be used to form two or more layers. For example, the intermediate layer may be formed of any one of amorphous silicon, oxide ceramics, nitride ceramics, organic polymer materials, or metals. The predetermined light is irradiated on the intermediate layer, and peeling occurs in the intermediate layer.

Common electrode film formation process (FIG. 3B ): The common electrode film formation process is a process of forming the common electrode film 3 on the peeling layer 11. The common electrode film has a function as one electrode of the piezoelectric element.

The composition of the common electrode film 3 is not particularly limited, but it is preferable to use a composition that has high conductivity and can withstand the temperature when the piezoelectric element is formed. For example, Pt, Au, Al, Ni, In, etc. can be used.

As a method of forming the common electrode film 3, it is preferable to select an appropriate method according to its composition and thickness. For example, sputtering method, vapor deposition method, CVD method, electroplating method, electroless plating method, etc. can be used.

Piezoelectric element forming process (FIG. 3C ): The piezoelectric element forming process is a process of forming a piezoelectric thin film 41 and an upper electrode film 42 on the common electrode film 3 in a predetermined thickness.

As the composition of the piezoelectric thin film 41, a ferroelectric ceramic represented by lead zirconate titanate (PZT) or the like is preferable.

The formation of the piezoelectric thin film 41 is preferably performed by a sol-gel method. The PZT-based sol with a predetermined composition adjusted by the sol-gel method is coated on the common electrode film 3, and the so-called sintering process is repeated a predetermined number of times. As the coating method, a spin coating method, a roll coating method, a die coating method, etc. can be used. After coating and sintering are repeated a predetermined number of times, if integral sintering is performed, a piezoelectric thin film 41 having a perovskite crystal structure can be formed. Furthermore, in addition to the sol-gel method, a sputtering method may also be used.

The composition and formation method of the upper electrode film 42 are the same as those of the common electrode film 3.

Corrosion process (Figure 3D): In the etching process, the upper electrode film and the piezoelectric film are etched and formed into the shape of the piezoelectric element.

As the etching method, dry etching with good anisotropy is preferred. On the upper electrode film 42, a patterned photoresist is placed in the shape of a piezoelectric element and then etched. Adjust the corrosion rate by selecting the corrosive gas appropriately. In addition, the etching time is managed to remove the upper electrode film 42 and the piezoelectric thin film 41 in the region where the photoresist is not provided, so that the common electrode film 3 is exposed. After etching, the photoresist is removed by ashing.

Accumulator forming process (Figure 4E): In the accumulator forming process, the accumulator part is covered and formed on the piezoelectric element. The stocker member 5 is a U-shaped cover member whose cross section is as shown in FIG. 4E. On a part of it, an opening (not shown in the figure) for supplying ink from an external ink bottle is provided.

The hopper member 5 preferably has a certain degree of mechanical strength and durability against ink, and heat resistance is not particularly required. Therefore, any material such as resin, silicone, glass, metal, etc. can be selected as the composition of the hopper part.

Before bonding the stocker member 5, wiring with respect to each piezoelectric element 4 is performed. That is, each output terminal of a driving circuit not shown in the figure is connected to the upper electrode 42 of each piezoelectric element 4, and the ground terminal of the driving circuit is connected to the common electrode film 3. Then, the stocker member 5 is bonded so as to cover the piezoelectric element 4. The ink reservoir 51 is formed on the inner side of the hopper member 5. The resin used for bonding can be arbitrarily selected.

Peeling process (FIG. 4F ): In the peeling process, light 60 is irradiated from the inner side (lower side in FIG. 4F) of the first base 10 to abrade the peeling layer 11, and the first base 10 is peeled off.

It is determined by the composition of the peeling layer, irradiated light, and other factors that the irradiated light produces intra-layer peeling, or interface peeling, or intra-layer peeling in the peeling layer. The main factors include, for example, the type, wavelength, intensity, and depth of the irradiated light.

The irradiation light is preferably irradiation light that can cause delamination and/or interface delamination in the peeling layer. For example, X-rays, ultraviolet rays, visible light, infrared rays (heat rays), lasers, millimeter waves, microwaves and other electromagnetic waves of various wavelengths can be used. . In addition, radiation (α-rays, β-rays, γ-rays), etc., which are electron beams may also be used. Among these irradiated lights, it is preferable to use a laser from the viewpoint of easily causing abrasion on the peeling layer.

As laser devices that generate such lasers, various gas lasers, individual lasers (semiconductor lasers), etc. can be cited, but excimer lasers, Nd-YAG lasers, argon lasers, CO2 lasers, CO lasers, and He-Ne lasers are particularly preferred. Among them, the excimer laser is the best. Since the excimer laser outputs high energy in the short waveband, it can take a short time to produce abrasion on the peeling layer. Therefore, almost no temperature rise occurs in the adjacent layer and the adhesive layer, and the deterioration and damage of the layer can be minimized to achieve peeling.

In the release layer 11, when there is a wavelength dependence on the generation of abrasion, the wavelength of the laser beam to be irradiated is preferably about 100 nm to 350 nm. In the peeling layer, due to layer changes such as gas evolution, vaporization, or sublimation, the wavelength of the laser beam to be irradiated is preferably about 350 nm to 1200 nm.

In addition, in the case of an excimer laser, the energy density of the irradiated laser is preferably about 10 to 5000 mJ/cm2. The irradiation time is preferably about 1 to 1000 nsec, and more preferably about 10 to 100 nsec. If the energy density is low or the irradiation time is short, then sufficient abrasion will not occur, and if the energy density is high or the irradiation time is long, the irradiated light passing through the release layer and the intermediate layer will have an adverse effect on the layer to be copied.

It is best to irradiate light with uniform intensity. The light irradiation direction is not limited to the direction perpendicular to the release layer, and may be a direction inclined at a predetermined angle with respect to the release layer. In addition, in the case where the area of the peeling layer is larger than the irradiation area of one irradiated light, the entire area of the peeling layer may be irradiated in multiple times. In addition, the same place can be irradiated multiple times. In addition, it is also possible to irradiate the same area or different areas with light of different types and different wavelengths (wavelength bands) multiple times.

After the first base 10 is peeled off, if there are residues of the peeling layer on the common electrode film 3, these residues are removed by washing.

Bonding process (FIG. 4G): The bonding process is a process of bonding the pressure chamber substrate 2 manufactured according to different processes on the common electrode film 3. Hereinafter, the manufacturing method of the pressure chamber substrate will be briefly described with reference to FIG. 5.

Master disk manufacturing process (FIG. 5A): First, a master disk 16 for replicating the pressure chamber substrate 2 is manufactured. After forming a pattern on the base material along areas other than the cavity 21 and the common flow path 23, the master 16 is manufactured by etching to a predetermined depth. The composition of the base material, that is, the base plate, is preferably corrodible. In addition to silicone, glass, quartz, resin, metal, ceramic or film can be used. In the patterned photoresist, a positive photoresist in which a cresol-based resin is mixed with a diazonaphthol derivative as a photosensitizer or the like can be used as it is. The photoresist layer is formed according to the spin coating method, the dipping method, the spraying method, and the bar code method.

After exposure, if the development process is performed according to predetermined conditions, the photoresist in the exposed area can be selectively removed. If etching is performed in this state, the portion corresponding to the side wall 22 and the like are corroded, and a mold for manufacturing the pressure chamber substrate 2 can be obtained. As the corrosion method, a wet method and a dry method can be selected. The material of the base material, corrosion profile, corrosion rate and other conditions are appropriately selected.

After etching, the photoresist is removed, and a master disk 16 is made.

In addition, during the etching, the depth of the etching is equal to the height corresponding to the side wall 22 and the like formed on the substrate of the pressure chamber. The height of the side wall is designed to be about 200 μm in, for example, an inkjet recording head having a resolution of 720 dpi.

Substrate forming process (FIG. 5B): After the master disk 16 is formed, the substrate material 2b is coated on the surface of the master disk 16, and the pressure chamber substrate 2 is formed by curing. As the substrate material, any material that satisfies the characteristics of mechanical strength and corrosion resistance required as a pressure chamber substrate for ink ejection is sufficient. There is no particular limitation on its composition, but it is best to use light, heat, or use A material that is cured by both light and heat. In the case of using this material, a universal exposure device, baking oven and hot plate can be used, which can achieve cost reduction and space saving. As such a substance, synthetic resins such as acrylic resins, epoxy resins, melamine resins, phenol resins, styrene resins, or polyimine resins, or silicon polymers such as polysilazanes can be used, for example. When a solvent component is included in the substrate material, the solvent is removed by heat treatment. In addition, as the substrate material, thermoplastic materials can also be used. For example, hydrated glass containing several to several tens of wt% moisture can be used.

In the coating method of the substrate material, a spin coating method, a dipping method, a spraying method, a roller coating method, a barcode method, or the like can be used.

Substrate peeling process (FIG. 5C ): Next, the cured substrate material 2 b, that is, the pressure chamber substrate 2, is peeled from the master disk 16.

As a peeling method, the master 16 is fixed, and stretch peeling is performed while maintaining the suction and fixing of the pressure chamber substrate 2. In the case where the adhesiveness between the master disk and the pressure chamber substrate is high, it is preferable to shape the concave portion of the master disk 16 into a predetermined tapered shape in advance. In addition, before peeling, light is irradiated on the interface between the master disk and the pressure chamber substrate, so that the adhesion between the master disk and the pressure chamber substrate is reduced or may disappear. At the interface between the master disk and the pressure chamber substrate, while weakening the bonding force between atoms or molecules, the gas released from the pressure chamber substrate is used to promote separation. The light used is preferably, for example, an excimer laser. In the case of irradiating light, the master 16 must be formed of a light-transmitting material. Furthermore, it is preferable to form a layer corresponding to the above-mentioned peeling layer on the interface between the master 16 and the pressure chamber substrate 2 in advance. Specifically, the above-mentioned method can be used as it is.

Nozzle forming process (FIG. 5D ): The nozzle 25 is formed on the peeled pressure chamber substrate 2.

The method of forming the nozzle 25 is not particularly limited. For example, various methods such as photolithography, laser processing, FIB processing, and electrical discharge processing can be used.

The pressure chamber substrate 2 manufactured by the above process is bonded to the common electrode film 3 where the stocker member 5 is bonded. The surface of the pressure chamber substrate 2 where the nozzle is not provided is bonded to the common electrode film 3 so that each cavity 21 corresponds to the piezoelectric element 4.

According to the above-mentioned embodiment 1, since the piezoelectric element is formed on the first base, the pressure chamber substrate with a thin thickness is manufactured by other processes, and finally the piezoelectric element and the pressure chamber substrate are bonded, even if the pressure chamber substrate is mechanically weak It is also possible to manufacture inkjet recording heads with high yields. Therefore, since the pressure chamber substrate can be formed thinner than the conventional one, a high-resolution inkjet recording head can be manufactured.

<Example 2>

The second embodiment relates to a method of manufacturing an ink jet recording head in which the piezoelectric element formed on the base is bonded to other bases at one time, then the pressure chamber substrate is bonded, and finally the accumulator member is bonded.

In the second embodiment, since the structure of the manufactured ink jet recording head is the same as that of the above-mentioned embodiment 1, the description is omitted.

(Method of Manufacturing Inkjet Recording Head) Next, referring to Figs. 6 to 7, a method of manufacturing the inkjet recording head of the present invention will be described. These drawings are cross-sectional views of the manufacturing process of the inkjet recording head showing the state cut in the width direction of the cavity.

The peeling layer forming process, the common electrode film forming process, the piezoelectric element forming process (FIG. 6A), and the etching process (FIG. 6B) are different from those of the peeling layer forming process (FIG. 3A) and the common electrode film of Example 1 above. The forming process (FIG. 6B), the piezoelectric element forming process (FIG. 6C), and the etching process (FIG. 6D) are the same, so the description thereof is omitted.

Bonding process (FIG. 6C): The bonding process is a process of bonding the surface of the piezoelectric element 4 forming the first base 10 and the second base using an adhesive.

Since the composition as the second base is the same as the first base 10 of the first embodiment described above, the description thereof is omitted.

As the composition of the adhesive used for the adhesive layer 13, for example, any adhesives such as epoxy-based, acrylate-based, and silicone-based adhesives can be used. In the second peeling process described later, these adhesives are determined based on whether peeling occurs at the interface of the adhesive layer or within the layer.

However, in this embodiment, by applying light, heat, or both light and heat, it is necessary to generate intra-layer peeling inside the adhesive layer. Therefore, as a thermoplastic resin, the composition preferably contains -CH2-, -CO- (ketone), -CONH- (amide), -NH- (imine), -COO- (ester), -N= Materials with bonds such as N-(azo) and -CH=N-() (the bonds between these atoms can be cut by light irradiation). In addition, in the structural formula, there may also be aromatic hydrocarbons (1 or 2 or more benzene rings or condensed rings) materials. Specific examples of such organic polymer materials include polyolefin resins such as polyethylene and polypropylene, polyimide resins, polyamide resins, polyester resins, acrylic resins, and epoxy resins. , Melamine resin, phenol resin, etc.

For example, the adhesive layer 13 can be formed by a coating method. In the case of using a curable adhesive, for example, a curable adhesive is applied to the surface of the piezoelectric element 4 as the layer to be replicated, and the second base 12 is adhered thereon, and then the curable adhesive is used The curing method corresponding to the characteristics of the adhesive is to cure the curing adhesive to bond the copied layer and the second base 12.

In the case of using a light-curing adhesive, apply the light-curing adhesive to the layer to be copied, and after arranging the light-transmitting second base 12 on the uncured adhesive layer, it is best The light for curing is irradiated from the side of the second base to cure the adhesive layer.

Furthermore, an adhesive layer 13 may be formed on the side of the second base 12, and a layer to be copied may be adhered thereon.

The first peeling process (FIG. 6D) and bonding process (FIG. 7E): Regarding the first peeling process and bonding process, since it is the same as the peeling process (FIG. 4F) and bonding process (FIG. 4G) of the above-mentioned embodiment 1, Therefore, the description is omitted. The manufacturing method of the pressure chamber substrate 2 is also the same as that of the above-mentioned first embodiment (FIG. 5 ).

Second peeling process (FIG. 7F): The second peeling process is a process of peeling off the second base 12 from the pressure chamber substrate 2 side by generating peeling in the adhesive layer 13 layer.

In this process, a predetermined energy is applied to the adhesive layer 13 to cause peeling on the adhesive layer. In the case of using a thermoplastic resin in the adhesive layer, peeling occurs by applying heat exceeding the transfer temperature of the thermoplastic resin as a whole.

In the adhesive layer, in the case of using the above-mentioned material that causes peeling in the layer by light irradiation, light is irradiated from the upper portion of the second base 12 to cause peeling.

Cleaning process (FIG. 7G): In the cleaning process, the adhesive remaining on the periphery of the piezoelectric element 4 is removed by peeling inside the layer. In order to remove the adhesive, a solvent that does not affect the piezoelectric element and the common electrode film is used. For example, using acetone, isopropanol, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, benzene, xylene, cresol, chlorobenzene, toluene, butyl acetate, n-hexane, cyclohexane, methyl ethyl ketone, Dichloromethane, N,N-dimethylformamide, dimethyl sulfoxide and other solvents.

Stocker forming process (FIG. 7H ): The stocker part forming process is a process of covering the piezoelectric element from which the adhesive has been removed and bonding the stocker part 5. Since the details are the same as the accumulator forming process (FIG. 4E) of Embodiment 1 described above, the description is omitted.

In addition, in this embodiment, by appropriately selecting the composition of the adhesive and the peeling method, peeling can occur at the interface between the piezoelectric element 4 and the common electrode film 3 and the adhesive layer 13. For example, as an adhesive agent, in the case of selecting an adhesive agent with greater adhesion to the second base than the adhesion between the piezoelectric element 4 and the common electrode film 3, as shown in FIG. 8, it is possible to Peeling occurs from the interface between the piezoelectric element 4 and the common electrode film 3 and the adhesive layer 13. If such peeling occurs, there is an advantage that the cleaning in the cleaning process can be easily achieved.

As described above, according to the second embodiment, the piezoelectric element is formed on the first base, and after bonding with the second base, the first base is peeled off. In addition, since the pressure chamber substrate with a thin thickness is manufactured by another process, and finally the pressure chamber substrate and the piezoelectric element are bonded, even if the pressure chamber substrate is mechanically weak, an inkjet recording head with a high yield can be manufactured. Therefore, since it can be formed to be thinner than the conventional pressure chamber substrate, a high-resolution inkjet recording head can be manufactured.

According to the second embodiment, before the first base is peeled off, since the piezoelectric element and the like are particularly fixed to the second base through the adhesive layer, there is an advantage of easy and safe handling of the piezoelectric element in the manufacturing process.

<Third Embodiment>

The third embodiment of the present invention is a modification of providing the bonding process and the second peeling process in the above-mentioned second embodiment.

The ink jet recording head and its manufacturing method of this embodiment are substantially the same as the above-mentioned embodiment. However, the difference is that the intermediate layer 14 is provided before the bonding process (FIG. 6C ), and then the second base 12 is bonded.

Deformation of the bonding process (FIG. 9A ): Before the bonding process, the intermediate layer 14 is formed on the second base 12 in advance.

As the composition of the intermediate layer 14, a composition that easily causes peeling at the interface with the adhesive layer 13, that is, a composition with low adhesiveness with the adhesive layer 13 is adopted.

For example, when an acrylate-based adhesive is used in the adhesive layer 13, a composition containing one or more metals selected from Ni, Cr, Ti, Al, Cu, Ag, Au, and Pt can be adopted. Generally, these metals have low adhesion to acrylic adhesives, and they can be formed with good controllability by using vacuum film forming methods such as sputtering, vapor deposition, or CVD.

In addition, as the composition of the intermediate layer 14, a composition that easily causes peeling in the intermediate layer 14 or the interface between the intermediate layer 14 and the second base 12 can be adopted. As such a composition, in addition to the same composition as the above-mentioned release layer 11, an anodic oxide film such as porous silicon or aluminum can be cited.

Modification of the second peeling process (FIG. 9B): In order to peel the second base 12 from the adhesive layer 13, in the case of using the intermediate layer 14 of the same composition as the peeling layer 11, as shown in FIG. The intermediate layer 14 is irradiated with light (laser) 60 on the side of the base 12, and peeling occurs.

Furthermore, in the case of using porous silicon, it can be peeled off within the layer of the intermediate layer 14 and the interface between the intermediate layer 14 and the second base 12 by cutting. In addition, when an anodic oxide film is used, it can be cut in the middle layer 14 by cutting, or mechanically such as cutting without an electric field, in the middle layer 14 and between the middle layer 14 and the second layer. The interface of the base 12 is peeled off. It is preferable to clean and remove the adhesive layer 13 remaining on the pressure chamber substrate 2 by solvent treatment or the like.

As described above, according to the third embodiment, since the intermediate layer is provided, the pressure chamber substrate and the second base can be easily peeled off.

According to the present invention, since the pressure chamber substrate is provided with a thin thickness, it is possible to provide an inkjet recording head that can correspond to high definition.

According to the manufacturing method of the ink jet recording head of the present invention, since a process different from the process of forming the piezoelectric element is used to form the pressure chamber substrate with a thin thickness, the manufacturing yield is improved and the cost can be reduced.

According to the manufacturing method of the inkjet recording head of the present invention, since the piezoelectric element formed by a process different from the process of forming the pressure chamber substrate is reliably peeled from the base, the manufacturing yield is improved. , And can achieve low cost.