JPH11179908A - Ink-jet head component and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a head which does not use an adhesive and stably discharges ink by carrying out an electroforming process using an electroformed mold by an exposure of a photosensitive insoluble material in two steps thereby forming a discharge opening of a relatively small size in a first electroforming step and a liquid chamber of a relatively large size in a second electroforming step. SOLUTION: An ink-jet head part has a first electroforming layer 11 forming a part of a bottom part of discharge openings. The electroforming layer 11 is formed by electroforming, including a liquid chamber wall 202a constituting many liquid chambers 201a which store ink and serve as a pressure chamber, and a discharge opening wall 102 with many discharge openings 101a each of which has a small-breadth small-height section to the liquid chamber 201a and through which pressured ink is discharged. This head part also has a second electroforming layer 12 forming a bottom part of the liquid chambers 201a. While the electroforming layer 12 is formed by electroforming, the layer is united with the first electroforming layer 11 in one body in the electroforming process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an ink jet head component used in an apparatus such as a printer for forming an ink image on a medium such as recording paper by discharging ink droplets.

[0002]

2. Description of the Related Art FIG. 4 shows the configuration of a conventional basic ink jet head. A nozzle plate 100 having an ejection port 101 serving as an ink ejection hole, a liquid chamber side wall component 200 having a liquid chamber side wall 202 forming a liquid chamber 201 serving as an ink pressurizing chamber, and a thin plate shape. Diaphragm 30
0 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. In addition, there is another heating method (also referred to as a bubble jet method) as an ink discharging method of the ink jet head. In the case of the heating method, the diaphragm 300 and the piezoelectric element 40 are used.
0 does not exist, and a heating element is formed on the base 500.
Whichever method is used, the nozzle plate 100 and the liquid chamber side wall part 2
00 is an essential component of the ink jet head.

The structure of each component shown in FIG. 4 will be described below. The plurality of liquid chambers 201 provided by the liquid chamber side wall 202 formed in the liquid chamber side wall part 200 serve as an ink flow path and an ink pressurizing chamber. In order to perform pressurization in the liquid chamber 201, the liquid chamber side wall 202 needs to have high rigidity. A large number of liquid chambers 201 are connected to one at one end, and the location is generally called a manifold (not shown). The manifold serves to supply ink into the liquid chamber 201.

A plurality of discharge ports 101 are formed in the nozzle plate 100, and one discharge port 101 is provided in one liquid chamber 2.
01 is arranged. The ink pressurized in the liquid chamber 201 is discharged from the discharge port 101.

[0005] The diaphragm 300 is a thin plate-shaped part usually having a thickness of about 3 to 5 µm. The diaphragm 300 transmits the distortion to the liquid chamber 201 when the piezoelectric element 400 expands and contracts due to the electrostriction effect, and the rigidity must be low.

The piezoelectric element 400, which is a driving body, generates distortion due to its own electrostriction effect, and pressurizes the ink in the liquid chamber 201 by the distortion.
Ink is ejected from No. 1. Therefore, each piezoelectric element 40
Reference numeral 0 corresponds to each of the liquid chambers 201. When one liquid chamber 201 is pressurized, the liquid chambers 201 are separated so as not to affect the other liquid chambers 201.

The separated piezoelectric elements 400 are mounted on a base 5
It is fixed on 00. The piezoelectric element 400 is mounted on the base 500
As a method of fixing the piezoelectric element 400, generally, a step of bonding the piezoelectric element 400 that has not been separated first to the base 500 with an adhesive, and then separating only the piezoelectric element 400 by cutting is performed. After the piezoelectric element 400 is fixed to the base 500, the piezoelectric element 400 is joined to the diaphragm 300.

In the basic configuration of the ink jet head as shown in FIG. 4, the nozzle plate 100 and the liquid chamber side wall component 200, which are manufactured separately, are joined by an adhesive. For this reason, an adhesive layer was always formed at the joint of each component.

The rigidity of the manufactured ink jet head differs depending on the thickness of the adhesive layer and the amount of protrusion, and as a result, the ejection performance also differs. Therefore, in the manufacture of the ink jet head, a great effort has been required for controlling the thickness of the adhesive layer and the amount of protrusion.

The nozzle plate 100 and the liquid chamber side wall component 200
Since they are separate bodies, precise alignment was performed at the time of joining.

In order to eliminate the trouble of being a separate body, it has been considered to integrally form the liquid chamber side wall part and the nozzle plate by injection molding. In this case, however, the liquid chamber is formed by forming the side wall, but not the discharge port. Because the hole diameter of the discharge port is 30-4
This is because it is 0 μm, which exceeds the limit of injection molding. Therefore, drilling was required after injection molding.
Excimer laser processing has been used for this drilling because processing accuracy is required.

[0012]

In the conventional ink jet head, as described above, the nozzle plate and the liquid chamber side wall component are joined by the adhesive. Therefore, an adhesive layer always exists on the joining surface, and it is necessary to accurately control the thickness and the amount of protrusion of the adhesive layer in the process of manufacturing the ink jet head. This is because the dispersion of the adhesive layer causes the rigidity of the ink jet head to vary and the ejection characteristics to vary. These variations have led to the deterioration of print quality.

Further, in a conventional ink jet head using an adhesive, when the ink is ejected for a long time, the adhesive is deteriorated, and the adhesive layer may be peeled off. In such a case, reliability regarding the ejection characteristics and durability of the inkjet head is lacking. In addition, since the nozzle plate and the liquid chamber side wall component are separate bodies, alignment is required at the time of joining. However, since the adhesive layer is interposed, high-accuracy alignment cannot be performed. If the positioning accuracy is poor, the ejection direction of the ink is deviated, which causes a deterioration in print quality.

On the other hand, in the method of forming the liquid chamber side wall parts by injection molding without using an adhesive, and then forming the discharge port by excimer laser processing, the material is made of a material in consideration of both injection moldability and excimer laser workability. One, and generally only polysulfone resin was available. For this reason, the rigidity of the liquid chamber side wall component is low, and sufficient pressurization is not performed even if an attempt is made to pressurize the ink inside the liquid chamber. As a result, the ink ejection characteristics were poor. This leads to poor print quality.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet head which forms an ink image on a medium such as recording paper by discharging ink droplets and which achieves high reliability and good print quality.

[0016]

According to the present invention, there is provided a method of manufacturing an inkjet head component, comprising:
First, an opaque conductive layer is formed by patterning the shape of the discharge port and the shape of the liquid chamber on a transparent substrate. The discharge port mold and liquid chamber made of a photosensitive insoluble material are formed on one surface of the transparent substrate on which the opaque conductive layer is formed. And mold. Next, an electroformed member is formed to a thickness that covers the upper surface of the discharge port mold and does not cover the upper surface of the liquid chamber type, and further forms a second liquid chamber type made of a photosensitive insoluble material on the liquid chamber type. . Thereafter, electroforming is performed on the electroformed member and the second liquid chamber mold. It is characterized by having a series of these steps.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The inkjet head component according to the present embodiment includes a part of a liquid chamber side wall 202a that is formed by an electroforming method, and forms a plurality of liquid chambers 201a that store ink and serve as a pressure chamber. A discharge port side wall 102, which has a small cross-sectional shape and has a large number of discharge ports 101a communicating with the liquid chamber 201a and discharging ink pressurized in the liquid chamber 201a, and a part of the bottom of the discharge port. A first electroformed layer 11 for forming the liquid chamber, a remaining portion of the side wall 202a of the liquid chamber formed by an electroforming method,
And a second electroformed layer 12 forming the bottom of the first electroformed layer 01a. Further, the second electroformed layer 12 is combined with the first electroformed layer 11 in the process of being formed by the electroforming method and is integrally formed.

FIG. 3 is a view showing a discharge port type for forming a discharge port side wall on a substrate and a liquid chamber type for forming a liquid chamber side wall. An opaque conductive layer 40 serving as an electrode for electroforming is patterned on the transparent substrate 30. Further, on one surface of the transparent substrate 30 where the opaque conductive layer 40 is formed, a lower photosensitive layer serving as an electroforming mold is provided. An insoluble material layer 21 is formed.

Lower photosensitive insoluble material layer 21 serving as an electroforming mold
Are a discharge port type 211, a liquid chamber type 212, a manifold type 2
13. The ejection port mold 211 takes the shape of the ink ejection hole, and the liquid chamber mold 212 takes the shape of the liquid chamber formed by the liquid chamber side wall. The manifold type 213 is a manifold that stores ink and supplies ink into the liquid chamber. Although only one discharge port type 211 and one liquid chamber type 212 are illustrated in FIG. 3 for explanation, originally, a large number of discharge port types 211 and liquid chamber types 212 are arranged side by side at a predetermined pitch. And liquid chamber type 2
12 are connected by a manifold die 213 at the rear end.

In the present invention, the state shown in FIG. 3 is a basic state, and the manufacturing process proceeds based on this substrate. First, steps up to a state shown in FIG. 3 will be described. First, an opaque conductive layer 40 was formed by patterning on a transparent substrate 30 having translucency. In the present embodiment, an opaque conductive layer 40 made of copper (Cu) is first placed on a transparent substrate 30 made of glass.
Was formed to a thickness of 0.2 μm by a sputtering method. Thereafter, the photosensitive resist was patterned into a desired shape on the opaque conductive layer 40 by a generally known photolithography method. Further, the portion not covered with the photosensitive resist was etched by wet etching to pattern the opaque conductive layer 40. The photosensitive resist was removed thereafter. As shown in FIG. 3, the opaque conductive layer 40 having a desired shape in the present embodiment has a shape of an ink ejection hole, a shape of a liquid chamber as an ink pressurizing chamber, and a shape of a manifold as an ink reservoir. The shapes are removed by etching.

Next, the opaque conductive layer 40 of the transparent substrate 30
After the photosensitive insoluble material was applied to the entire surface of the transparent substrate 30 where the photosensitive insoluble material was not applied, light was transmitted through the transparent substrate 30 from the other surface of the transparent substrate 30 where the photosensitive insoluble material was not applied. Such an exposure method is generally called a back exposure method. In the back exposure method, the opaque conductive layer 40 serves as an exposure mask, and can expose an arbitrary portion of the photosensitive insoluble material. In the present embodiment, THB-30 (trade name) manufactured by Nippon Synthetic Rubber Co., Ltd. was used as the photosensitive insoluble material. The spin coating method was used as a coating method, and spin coating was performed at a rotation speed of 2500 rpm for 10 seconds, so that a coating having a thickness of 30 μm could be performed. In the exposure, PEM-500 manufactured by Union Optical Co., Ltd. was used as an exposure apparatus, and 300 mJ was used.
/ Cm2.

Further, by developing the photosensitive insoluble material that is partially exposed, only the exposed portion is formed as the lower photosensitive insoluble material layer 21. The lower photosensitive insoluble material layer 21 has a discharge port shape 21 having a discharge port shape.
1, a liquid chamber type 212 having a liquid chamber shape, and a manifold type 213 having a manifold shape. In the present embodiment, using a developer dedicated to THB-30,
Development was performed at a liquid temperature of 5 ° C. for 5 minutes.

Through the above steps, the lower photosensitive insoluble material layer 2 composed of the discharge port type 211, the liquid chamber type 212, and the manifold type 213 is formed on the transparent substrate 30 as shown in FIG.
1 is formed. In the present invention, based on the substrate in the state shown in FIG. 3, an inkjet head component comprising an electroformed member having a discharge port and a liquid chamber is formed.

FIG. 2 is a view showing main steps of the manufacturing method of the present invention. AA near the discharge port 101a in FIG.
A part of the cross section and a part of the BB cross section in the vicinity of the liquid chamber 201a are compared for each process.

FIG. 2A shows the discharge port mold 211 in the state of FIG.
2 is a cross section near the liquid chamber mold 212 and a cross section near the liquid chamber mold 212. The steps so far are as described above. An opaque conductive layer 40 made of Cu is patterned on one surface of a transparent substrate 30 made of a glass substrate.
The lower photosensitive insoluble material layer 21 is formed only on the portion where 0 does not exist. In the present embodiment, the width b1 of the discharge port mold 211 and the width b2 of the liquid chamber mold 212 are set to b1 = 20 μm and b2 = 60 μm, respectively. The thickness of the lower photosensitive insoluble material layer 21 is 3 as described above.
The thickness was 0 μm.

Next, as shown in FIG. 2B, a lower electroformed layer 11 is formed on the opaque conductive layer 40 by electroforming. What is important here is that the lower electroformed layer 11 is formed on all of the side and upper surfaces in the discharge port type, and the lower electroformed layer 11 is formed on a part of the side and upper surfaces in the liquid chamber type. This is to set the thickness of the casting layer 11. The upper part of the liquid chamber mold must never be covered with the lower electroformed layer 11. The above is the most characteristic feature of the manufacturing method of the present invention. In the present embodiment, the lower electroformed layer 11 made of Ni is formed with a thickness of 44 μm by nickel (Ni) electroforming. As a result, as shown in FIG. 2 (b), the upper surface of the discharge port type is covered with the lower electroformed layer 11, and the upper surface of the liquid chamber type is formed such that the lower electroformed layer 11 is formed only on the periphery. did it.

Further, the upper photosensitive insoluble material layer 22 was patterned on the surface on which the lower electroformed layer 11 of FIG. 2B was formed by photolithography using a back exposure method (FIG. 2C). The upper photosensitive insoluble material layer 22 is
It is formed only on the liquid chamber type that is exposed through the transparent substrate 30 and the lower photosensitive insoluble material layer 21. In the present embodiment, the second photosensitive insoluble material layer 22 is formed of THB-30. First, THB-30 was spin-coated at 1000 rpm.
m, a thickness of 60 μm under the condition of 10 seconds,
Back exposure was performed at an exposure amount of 0 mJ / cm2, and finally 4
The second photosensitive insoluble material 22 is formed by developing with a dedicated developer at 0 ° C.

Next, as shown in FIG. 2D, electroforming is performed so as to cover all the side surfaces and the upper surface of the upper photosensitive insoluble material layer 22, and the lower electroforming layer 11 and the upper electroforming layer 12 An inkjet head component having a discharge port and a liquid chamber is formed. In the present embodiment, the Ni electroforming method is used for forming the upper electroformed layer 12. The thickness of the upper electroformed layer 12 was 150 μm so that the upper photosensitive insoluble material layer 22 was completely covered.

Eventually, the ink jet head components comprising the lower electroformed layer 11 and the upper electroformed layer 12 are thereafter formed into a transparent substrate 30, an opaque conductive layer 30, and a lower photosensitive insoluble material layer 2.
1. The upper photosensitive insoluble material layer 22 is removed, and the completed inkjet head component is cut so as to have desired outer dimensions. By this cutting, the discharge port is also formed at the same time, and the discharge hole is completed.
In the present embodiment, the inkjet head component can be separated from the transparent substrate 30 by dissolving the opaque conductive layer 40 made of Cu and then also dissolving the lower photosensitive insoluble material layer 21 and the photosensitive insoluble material layer 22. . Further, in the present embodiment, the cutting process is performed so that the length of the discharge port is 50 μm.

The inkjet head component manufactured as described above has a rectangular orifice having a cross section of 20 μm in width and a height of 30 μm, a width of 60 μm (bottom) and a height of 90 μm.
And a liquid chamber having a step on the side wall of the liquid chamber. The step on the side wall was about 10 μm in the present embodiment, but if it is appropriate, there is almost no effect on the ink ejection characteristics.

[0031]

As described above, in the method for manufacturing an ink jet head component of the present invention, the discharge port and the ink jet head component forming the liquid chamber are integrally formed without using an adhesive. There is no variation in the adhesive layer, which has been regarded as a conventional problem. As a result, the ink ejection becomes stable,
Printing quality is good.

Further, since the bonding by the adhesive is not performed, the deterioration of the ink ejection characteristics caused by the deterioration of the adhesive does not occur. Therefore, the ink jet head is more durable than the conventional ink jet head, and the reliability over time is also improved.

Further, by integrally forming the discharge port and the liquid chamber without using an adhesive, highly accurate positioning of the discharge port and the liquid chamber can be achieved. As a result, it is possible to suppress the displacement of the ink ejection direction to be smaller than before, and it is possible to obtain high printing quality.

According to the method for manufacturing an ink jet head component of the present invention, since the component is formed by electroforming,
The inkjet head component can be made of a metal material. Therefore, the rigidity of the inkjet head component is extremely high, and it is possible to sufficiently pressurize the ink inside the liquid chamber. As a result, the ink ejection characteristics are improved, and the printing quality is improved.

As described above, according to the manufacturing method of the present invention, it is possible to manufacture an ink jet head having good printing quality and high reliability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an inkjet head component according to the present invention.

FIG. 2 is a cross-sectional view of each step near a discharge port and a liquid chamber in the manufacturing method according to the present invention.

FIG. 3 is a perspective view showing a discharge port type and a liquid chamber type before electroforming according to the present invention.

FIG. 4 is a configuration diagram of a conventional basic inkjet head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Lower electroformed layer 12 Upper electroformed layer 21 Lower photosensitive insoluble material layer 22 Upper photosensitive insoluble material layer 30 Transparent substrate 40 Opaque conductive layer 100 Nozzle plate 101, 101a Discharge port 102 Discharge port side wall 200 Liquid chamber side wall part 201, 201a Liquid chambers 202, 202a Liquid chamber side wall 211 Discharge port type 212 First liquid chamber type 222 Second liquid chamber type 213 Manifold type 300 Diaphragm 400 Piezoelectric element 500 Base

Claims (2)

[Claims] 1. A liquid chamber side wall forming a plurality of liquid chambers serving as pressurizing chambers for storing ink, and having a cross-sectional shape having a small width and height with respect to the liquid chambers, and communicating with the liquid chambers. An ejection port side wall forming a number of ejection ports for ejecting ink pressurized in the liquid chamber, and a bottom plate forming a bottom of the ejection port side wall and the liquid chamber side wall, and formed by electroforming. An inkjet head component to be manufactured, comprising: a first electroformed layer formed by electroforming to form a side wall of the discharge port, a bottom of the discharge port, and a part of a side wall of the liquid chamber; A second electroformed layer forming the remaining portion of the side wall of the liquid chamber formed by a method and the bottom plate;
Wherein the electroformed layer is formed integrally with the first electroformed layer in a process of being formed by an electroforming method. 2. A liquid chamber side wall forming a plurality of liquid chambers that store ink and serve as a pressure chamber, and have a cross-sectional shape having a small width and height with respect to the liquid chamber, and communicate with the liquid chamber. An ejection port side wall forming a number of ejection ports for ejecting ink pressurized in the liquid chamber, and a bottom plate forming a bottom of the ejection port side wall and the liquid chamber side wall, and formed by electroforming. A method for manufacturing an inkjet head component to be manufactured, comprising: forming a first substrate on a transparent substrate on which an opaque conductive layer patterned with a predetermined shape for forming the discharge port side wall and the liquid chamber side wall is formed; The photosensitive insoluble material is applied, exposed from the transparent substrate side through the opaque conductive layer, and developed to form a first side for forming the liquid chamber side wall.
Forming a discharge hole type having a smaller width with respect to the liquid chamber type and the first liquid chamber type for forming the discharge port side wall; and forming the upper surface of the opaque conductive layer and the discharge having a smaller width. Forming a first electroformed layer having a thickness that covers an upper surface of the mold and that does not cover the upper surface of the first liquid chamber mold; and an upper surface of the first electroformed layer and the first electroformed layer. By applying a second photosensitive insoluble material to the upper surface of the liquid chamber type, exposing it from the transparent substrate side through the opaque conductive layer and the first electroformed layer, and developing the first liquid chamber. Forming a second liquid chamber mold in which a second photosensitive insoluble material is patterned on the upper surface of the mold; and electroforming on the first electroformed layer to cover the upper surface of the second liquid chamber mold. Forming a second electroformed layer having a thickness of the order of: the transparent substrate, the discharge port type, the first liquid chamber type, Removing the second liquid chamber mold from the first electroformed layer and the second electroformed layer; and determining a predetermined position of the discharge port formed by the first electroformed layer and the second electroformed layer. Forming the opening of the discharge port by cutting the position of the ink jet head.