JP4159659B2 - Manufacturing method of inkjet head component - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing an inkjet head unit products for use in apparatus such as a printer for forming an ink image on a medium such as recording paper by ejecting ink droplets.
[0002]
[Prior art]
The configuration of a conventional basic ink jet head is shown in FIG. A conventional inkjet head is a liquid in which a nozzle plate 200 having an ejection port 210 opened for ejecting ink and a liquid chamber side wall 120b constituting a liquid chamber 110b serving as an ink pressurizing chamber are formed. The chamber component 100b, a thin plate-shaped diaphragm 300, and a base 500 on which the piezoelectric element 400 is disposed. An ink jet head having such a piezoelectric element 400 is called a piezoelectric ink jet head. Note that a heat generation type (also referred to as a bubble jet method) is another method for ejecting ink from the inkjet head. However, in the case of the heat generation type, the diaphragm 300 and the piezoelectric element 400 do not exist, and a heat generation element is formed on the base 500. Is done. In either method, the nozzle plate 200 and the liquid chamber component 100b are indispensable components of the inkjet head.
[0003]
The structure of each part shown in FIG. 7 will be described below. The plurality of liquid chambers 110b provided by the liquid chamber side wall 120b formed in the liquid chamber component 100b also serves as an ink flow path and an ink pressurizing chamber. A large number of liquid chambers 110b are connected to each other at one end, and this portion is generally called a manifold (not shown). The manifold is responsible for supplying ink into the liquid chamber 110b.
[0004]
In the nozzle plate 200, a plurality of discharge ports 210 are perforated, and one discharge port 210 is arranged so as to correspond to one liquid chamber 110b. Ink pressurized in the liquid chamber 110 b is ejected from the ejection port 210.
[0005]
Diaphragm 300 is a thin plate-like component usually about 3 to 5 μm. This diaphragm 300 is for transmitting the strain to the liquid chamber 110b when the piezoelectric element 400 expands and contracts due to the electrostrictive effect, and its rigidity must be low.
[0006]
The piezoelectric element 400 as a driving body generates distortion by its own electrostrictive effect, pressurizes the ink in the liquid chamber 110b by the distortion, and discharges the ink from the corresponding discharge port 210. Therefore, each piezoelectric element 400 corresponds to each liquid chamber 110b, and when one liquid chamber 110b is pressurized, it is separated so as not to affect the other liquid chamber 110b. ing. These separated piezoelectric elements 400 are fixed on a base 500.
[0007]
In recent years, ink jet printers are required to have high printing quality, and for this reason, high-density printing has been rapidly advanced. In the ink jet head, high density printing means high density of each component as it is. Among the above-described inkjet head components, the liquid chamber side wall 120b constituting the liquid chamber 110b needs to be formed as finely and as densely as possible.
[0008]
Therefore, a method of combining the photolithography method and the electroforming method has been proposed as a method for forming the liquid chamber side wall 120b. FIG. 5 is a diagram showing a conventional method for manufacturing a liquid chamber part by photolithography and electroforming.
[0009]
In FIG. 5A, an opaque conductive film 20 that blocks light in a desired shape is formed on a transparent substrate 10 that transmits light, and the transparent conductive film 20 is exposed on the transparent substrate 10 so as to cover the opaque conductive film 20. An insoluble material layer 30 is applied. In this state, light is irradiated through the transparent substrate 10 as shown in FIG. 5A to expose the photosensitive insoluble material layer 30. In general, such an exposure method is called a back exposure method.
[0010]
Next, development is performed to form a photosensitive insoluble material layer 30b as shown in FIG. When the photosensitive insoluble material is exposed and developed by the back exposure method, the photosensitive insoluble material is patterned to be wide on the transparent substrate 10 side and narrow on the surface side as shown in FIG. This phenomenon becomes more prominent as the coated photosensitive insoluble material is thicker. This is caused by non-uniform exposure amount in the thickness direction of the photosensitive insoluble material.
[0011]
Next, an electroforming plating process is performed using the opaque conductive film 20 as an electrode to form a liquid chamber component 100b made of an electroforming material (FIG. 5D).
[0012]
Finally, the transparent substrate 10, the opaque conductive film 20, and the photosensitive insoluble material layer 30b are removed from the liquid chamber part 100b to complete the process. This manufacturing method corresponds to high density by using a photolithography method capable of forming a fine shape.
[0013]
Another manufacturing method for increasing the density of liquid chamber parts is a manufacturing method in which a silicon (Si) substrate is shaped by etching. FIG. 6 is a view showing a liquid chamber part manufactured by etching a Si substrate. A liquid chamber 110c is configured by a liquid chamber side wall 120c having a rectangular cross section in the liquid chamber component 100c, a manifold 130c for storing ink behind the liquid chamber 110c, and an ink supply port 140c behind the manifold 130c. However, it is similarly formed by etching.
[0014]
It is generally well known that anisotropic etching is performed on a Si substrate. The liquid chamber part 100c effectively uses this anisotropic etching for high density. By using anisotropic etching, the liquid chamber side wall 120c can be formed as a vertical wall, and as a result, the liquid chamber interval can be narrower than the inclined liquid chamber side wall, and high density can be achieved.
[0015]
[Problems to be solved by the invention]
When considering high density in a conventional ink jet head, the two types of liquid chamber components listed above were mainstream. However, each of the liquid chamber parts has its own problems.
[0016]
Liquid chamber parts by photolithography and electroforming have the advantage that the liquid chamber side wall can be finely formed, but the shape always has a certain inclination, which is one drawback. It was. The disadvantage is that when the width of the liquid chamber side wall is formed to be very narrow, the inclined side shape causes the liquid chamber side wall to have a triangular cross-sectional shape. The side wall of the liquid chamber having such a triangular cross-sectional shape no longer functions as the side wall of the liquid chamber, that is, the function of constituting individual liquid chambers and partitioning the liquid chambers. For the reasons described above, it can be said that the liquid chamber side wall having an inclination is inappropriate when the interval between the liquid chamber side walls (that is, the liquid chamber interval) is to be narrowed.
[0017]
On the other hand, in the case of a liquid chamber part by the Si etching method, the side wall of the liquid chamber and the cross section of the liquid chamber can be made into a rectangular shape, and a shape suitable for high density can be formed, however, because etching has anisotropy. The planar direction is etched only in a specific direction, and as shown in FIG. 6, the planar shape has an irregular shape formed by only a straight line having no curved shape. Such an irregular shape of the manifold or ink supply port that does not have a smooth curved shape at all causes unstable ink flow and causes bubbles to be mixed. Bubble mixing deteriorates the ink ejection performance, and in the worst case, makes it impossible to eject ink.
[0018]
The present invention aims at providing a method of manufacturing an ink-jet head unit products to enable suitable for high density, and no possibility of stable ink discharge bubbly.
[0019]
[Means for Solving the Problems]
In order to solve the above-described problems, an ink jet head component according to the present invention includes a liquid chamber side wall that forms a number of liquid chambers that store ink and serve as a pressure chamber, and a liquid chamber that is formed so as to cover the liquid chamber. An ink jet head component formed by electroforming using a liquid chamber mold in which the liquid chamber side wall is shaped by a photolithography method, and the liquid chamber side wall is the liquid plate. It is characterized by being formed perpendicular to the plane of the room top plate.
[0020]
Furthermore, the method of manufacturing an ink jet head component according to the present invention includes a liquid chamber side wall constituting a large number of liquid chambers for storing ink and serving as a pressure chamber, and a liquid chamber upper plate formed so as to cover the liquid chamber. The liquid chamber side wall is shaped by a photolithographic method, and a liquid chamber mold that is formed by transfer molding by electroforming using a liquid chamber mold as a master mold, the liquid chamber mold being A step of applying a photosensitive insoluble material layer on a transparent substrate on which an opaque conductive film patterned in a desired shape is formed; and 5 with respect to a surface through the transparent substrate and perpendicular to the transparent substrate. Exposing the photosensitive insoluble material layer by irradiating light at an angle of 10 degrees to 10 degrees, and an angle of -5 degrees to -10 degrees with respect to a plane through the transparent substrate and perpendicular to the transparent substrate To irradiate with light Forming a photosensitive insoluble material layer in which the vertical wall shape with respect to the photosensitive insoluble material layer is developed and exposing the photosensitive insoluble material layer plane of the transparent substrate I, to be formed by It is a feature.
[0021]
Furthermore, the method of manufacturing an ink jet head component according to the present invention includes a liquid chamber side wall constituting a large number of liquid chambers for storing ink and serving as a pressure chamber, and a liquid chamber upper plate formed so as to cover the liquid chamber. The liquid chamber side wall is shaped by a photolithographic method, and a liquid chamber mold that is formed by transfer molding by electroforming using a liquid chamber mold as a master mold, the liquid chamber mold being a step photosensitive insoluble material layer to patterned opaque conductive film on a transparent substrate which is formed to coated to a desired shape, while rotating the transparent substrate, one 且and through the transparent substrate of the transparent a step of exposing the photosensitive insoluble material layer by irradiating light at an angle of -10 degrees to 10 degrees or -5 degrees 5 degrees with respect to a plane perpendicular to the substrate, developing the said photosensitive insoluble material layer Plane of transparent substrate Forming a photosensitive insoluble material layer in which the vertical wall shape for, and characterized in that it is formed by.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a perspective view of an essential part of an inkjet head component according to the present invention. Hereinafter, an embodiment of the present invention will be described with reference to FIG. The liquid chamber side wall 120a is formed side by side at a predetermined interval on a liquid chamber upper plate 150a (located below the liquid chamber side wall 120b in the drawing) as a base. A space surrounded by the liquid chamber upper plate 150a and the liquid chamber side wall 120a is the liquid chamber 110a, which becomes an ink pressurizing chamber. A manifold 130a for storing ink is formed behind the liquid chamber 110a, and an ink supply port 140a is formed behind the manifold 130a. The liquid chamber component 100a is formed by the above configuration.
[0023]
In the present embodiment, the liquid chamber side wall 120a has a rectangular cross-sectional shape with a height of 100 μm and a width of 50 μm, and the liquid chamber side walls 120a are formed side by side at intervals of 100 μm. Therefore, the cross-sectional shape of the liquid chamber 110a formed therein is a rectangular shape having a height of 100 μm and a width of 50 μm.
[0024]
On the other hand, the planar shape of the liquid chamber side wall 120a is designed so that the end portion on the manifold 130a side is formed with a smooth curve, and the ink is smoothly supplied to the liquid chamber 110a.
[0025]
Furthermore, the planar shape of the connecting portion from the ink supply port 140a to the manifold 130a is also formed with a smooth curve, and is designed to prevent air bubbles from entering.
[0026]
The liquid chamber part 100a having the above shape is formed by electroforming, and in this embodiment, the material is nickel (Ni). Ni is a material often used for electroforming, but it is a material excellent in corrosion resistance, and is very suitable as a component of liquid chamber parts that are constantly exposed to ink.
[0027]
Next, a method for manufacturing the inkjet head component according to the present embodiment will be described. FIG. 2 is a view showing a method of manufacturing the inkjet head component according to the present embodiment. On the transparent substrate 10, an opaque conductive film 20 in which the liquid chamber side wall, the manifold, and the planar shape of the side wall constituting the ink supply port are patterned is formed. A photosensitive insoluble material layer 30 is coated on the entire surface of the transparent substrate 10 on which the opaque conductive film 20 is formed. In this embodiment, a 0.4 mm thick glass substrate is used for the transparent substrate 10, and a copper (Cu) film formed to a thickness of 0.2 μm by a sputtering method is used for the opaque conductive film 20. A thick film negative resist (trade name: THB-130N) manufactured by JSR Co., Ltd., which was applied by spin coating with a thickness of 100 μm was used for No. 30. Patterning of the opaque conductive film 20 was performed by using a commonly used photolithography method and etching method. The photosensitive insoluble material layer 30 having a thickness of 100 μm could be formed by performing spin coating treatment twice for 10 seconds at 1000 rpm.
[0028]
In the present embodiment, a back exposure method is used in which light is irradiated from the other surface of the transparent substrate 10 where the photosensitive insoluble material 30 is not coated, and the photosensitive insoluble material layer 30 is exposed through the transparent substrate. . At this time, the opaque conductive film 20 serves as an exposure mask, and an exposed portion and an unexposed portion are generated in the photosensitive insoluble material layer 30.
[0029]
In the present embodiment, light is irradiated from a direction inclined by a predetermined angle with respect to a reference plane perpendicular to the transparent substrate 10 (FIG. 2A). Hereinafter, this angle is defined as a positive exposure angle + θ. In this embodiment, the positive exposure angle + θ is set to 6 degrees, and exposure is performed with an exposure amount of 600 mJ / cm 2.
[0030]
Further, as shown in FIG. 2B, the light is irradiated at an angle of a predetermined angle from the direction of light irradiation in FIG. Hereinafter, this angle in FIG. 2B is defined as a negative exposure angle −θ with respect to the positive exposure angle + θ in FIG. In this embodiment, the negative exposure angle −θ is set to −6 degrees, and exposure is performed with an exposure amount of 600 mJ / cm 2. As a result of the exposure twice in FIGS. 2A and 2B, the photosensitive insoluble material layer 30 is partially exposed at an exposure amount of 1200 mJ / cm 2. For THB-130N, which is the photosensitive insoluble material layer 30 used in the present embodiment, this exposure amount is sufficient for light exposure.
[0031]
Next, the photosensitive insoluble material layer 30 partially exposed by the exposure was developed using a dedicated developer. As a result, a photosensitive insoluble material layer 30a having a wall shape perpendicular to the plane of the transparent substrate 10 as shown in FIG. 2C could be formed. The thing of this state becomes an electroforming mold for the electroforming process performed later. In this embodiment, development was performed for 5 minutes with a 40 ° C. THB-130N dedicated developer.
[0032]
Next, as shown in FIG. 2D, an electroforming process is performed on the electroforming mold obtained in FIG. 2C using the opaque conductive film 20 as an electrode to form the liquid chamber part 100a. Finally, the transparent substrate 10, the opaque conductive film 20, and the photosensitive insoluble material layer 30 a, which are electroforming molds, are removed from the liquid chamber component 100 a to complete the process.
[0033]
In the present embodiment, the liquid chamber part 100a is formed by Ni electroforming. At that time, the electroforming conditions were a current density of 1 A / dcm2, a bath liquid temperature of 50 ° C., and an electroforming time of 10 hours. The composition of the bath solution used is the following composition.
5L of pure water
Nickel sulfamate 1650g
150g nickel chloride
225g of boric acid
Sodium lauryl sulfate 5g
[0034]
On the other hand, in the present embodiment, the electroforming was removed by first dissolving the opaque conductive film 20 made of Cu with nitric acid and then dissolving the photosensitive insoluble material layer 30a with an aqueous potassium hydroxide solution.
[0035]
We have experimentally demonstrated that the vertical wall, which is a feature of the present invention, is achieved by setting the positive exposure angle + θ and the negative exposure angle −θ within a predetermined range. FIG. 4 is a view showing the exposure angle θ and the shape of the photosensitive insoluble material layer formed at that time. Note that the exposure angle θ referred to here is a value represented by an absolute value, and positive / negative is not distinguished.
[0036]
As shown in FIG. 4, when the exposure angle θ is smaller than 5 degrees, the photosensitive insoluble material layer 30b is patterned into a shape in which the vicinity of the transparent substrate 10 is wide and the vicinity of the surface is narrow. This shape is almost the same as the shape formed by the conventional back exposure method.
[0037]
On the other hand, if the exposure angle θ exceeds 10 degrees, the photosensitive insoluble material layer 30c is conversely patterned into a shape having a narrow width near the transparent substrate 10 and a wide area near the surface. In the worst case, there will be a situation where adjacent walls stick together.
[0038]
As described above, when the experiment was performed by changing the value of the exposure angle θ, it was found that the photosensitive insoluble material layer 30a was formed as a vertical wall when the exposure angle θ was 5 degrees or more and 10 degrees or less.
[0039]
Furthermore, when another experiment was advanced and the experiment was performed with the positive exposure angle + θ = 10 degrees and the negative exposure angle −θ = −5 degrees, it was confirmed that a vertical wall was formed even in this case. did it. That is, if the positive exposure angle + θ is in the range of 5 ° to 10 ° and the negative exposure angle −θ is in the range of −10 ° to −5 °, the exposure direction may be asymmetric. It became clear from the result.
[0040]
(Second Embodiment)
Another method for producing the inkjet head component of the present invention will be described below. FIG. 3 shows a part of the manufacturing method according to the second embodiment of the present invention. Similar to the first embodiment, an opaque conductive film 20 patterned in a desired shape is formed on a transparent substrate 10, and a photosensitive insoluble material layer 30 is applied to the entire upper layer thereof. ing. Each material and shape are not different from those of the first embodiment.
[0041]
As shown in FIG. 3, light is irradiated from a direction inclined by a predetermined exposure angle θ from the transparent substrate 10 side to expose the photosensitive insoluble material layer 30. The exposure angle θ is an inclination angle with respect to a reference plane perpendicular to the transparent substrate 10 and is an angle indicated by an absolute value as described above. The feature of the present embodiment is that the transparent substrate 10 is rotated during the exposure. After this exposure step, the ink jet head component of the present invention was manufactured by performing the steps after FIG. 2C in the first embodiment.
[0042]
In this embodiment, the exposure angle θ is set to 6 degrees, the substrate rotation speed is set to 10 rpm, and exposure is performed at an exposure amount of 1200 mJ / cm 2. Other steps are not different from those of the first embodiment.
[0043]
It has also been confirmed in the present embodiment that the exposure angle θ (absolute value) must be set within a range of 5 degrees to 10 degrees.
[0044]
【The invention's effect】
According to the present invention, it is possible to form a liquid chamber part having a liquid chamber cross section having a fine rectangular shape, and as a result, it is possible to increase the density of the inkjet head.
[0045]
Furthermore, since the planar shape of the side walls constituting the liquid chamber side wall, the manifold, and the ink supply port can be freely designed with a smooth curve, a liquid chamber part free from the risk of air bubbles being mixed can be obtained. This achieves stable ink ejection performance and improves the reliability of the inkjet head.
[0046]
As described above, according to the present invention, an ink jet head having high density and high reliability is achieved.
[Brief description of the drawings]
FIG. 1 is a perspective view of an essential part of an inkjet head component according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a method for manufacturing an ink jet head component according to the first embodiment of the present invention.
FIG. 3 is a view showing a part of a method for manufacturing an inkjet head component according to a second embodiment of the present invention.
FIG. 4 is a diagram showing an exposure angle θ and the shape of an electroforming mold formed thereby.
FIG. 5 is a view showing a method of manufacturing an inkjet head component using a conventional photolithography method and an electroforming method.
FIG. 6 is a perspective view of an essential part of an ink jet head component manufactured by etching a conventional Si substrate.
FIG. 7 is a configuration diagram of a conventional basic inkjet head.
[Explanation of symbols]
10 Transparent substrate 20 Opaque conductive film 30, 30a, 30b, 30c Photo-insoluble material layer 100a, 100b Liquid chamber parts 110a, 110b Liquid chamber 120a, 120b, 120c Liquid chamber side wall 130a, 130c Manifold 140a, 140c Ink supply port 150a Liquid Upper plate 200 Nozzle plate 210 Discharge port 300 Diaphragm 400 Piezoelectric element 500 Base

Claims (2)

A liquid chamber side wall constituting a large number of liquid chambers for storing ink and serving as a pressure chamber, and a liquid chamber upper plate formed so as to cover the liquid chamber, the liquid chamber side wall being formed by a photolithography method. A method for manufacturing an inkjet head component that is transferred and molded by electroforming using a liquid chamber mold shaped by
A step of applying a photosensitive insoluble material layer on a transparent substrate on which an opaque conductive film patterned in a desired shape is formed,
Exposing the photosensitive insoluble material layer by irradiating light through the transparent substrate and at an angle of 5 to 10 degrees with respect to a plane perpendicular to the transparent substrate;
Exposing the photosensitive insoluble material layer by irradiating light through the transparent substrate and at an angle of -5 degrees to -10 degrees with respect to a plane perpendicular to the transparent substrate ;
Developing the photosensitive insoluble material layer to form a photosensitive insoluble material layer having a wall shape perpendicular to the plane of the transparent substrate ;
A method for manufacturing an ink jet head component, characterized in that the method is formed by : A liquid chamber side wall constituting a large number of liquid chambers for storing ink and serving as a pressure chamber, and a liquid chamber upper plate formed so as to cover the liquid chamber, the liquid chamber side wall being formed by a photolithography method. A method for manufacturing an inkjet head component that is transferred and molded by electroforming using a liquid chamber mold shaped by
A step of applying a photosensitive insoluble material layer on a transparent substrate on which an opaque conductive film patterned in a desired shape is formed,
The photosensitive insoluble material is irradiated with light at an angle of 5 degrees to 10 degrees or -5 degrees to -10 degrees with respect to a plane perpendicular to the transparent substrate through the transparent substrate while rotating the transparent substrate. Exposing the layer;
Developing the photosensitive insoluble material layer to form a photosensitive insoluble material layer having a wall shape perpendicular to the plane of the transparent substrate ;
A method for manufacturing an ink jet head component, characterized in that the method is formed by :

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