JPH06297706A - Ink jet head and production thereof - Google Patents

Abstract

PURPOSE:To provide a high density ink jet head stable in ink emitting characteristics in low cost by preventing the positional shift of ink passages, energy acting chambers and ink supply ports all of which are made of a photosensitive resin by a simple method. CONSTITUTION:The reference holes 3 of a substrate 1 and an orifice plate 8 are formed as cavities not having a photosensitive resin layer 4 formed thereto and ink passage grooves, energy acting chamber grooves and ink supply port grooves are formed by photolithography. Next, the substrate 1 and the orifice plate 8 are aligned on the basis of the same reference holes 3 to be bonded to obtain ink passages, energy acting chambers and ink supply ports.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head used in an apparatus such as a printer which ejects ink droplets to form an ink image on a medium such as recording paper.

[0002]

2. Description of the Related Art An ink jet head applied to an ink jet recording system (liquid jet recording system) generally has a fine ink discharge port (hereinafter referred to as an orifice), an ink supply port, an ink flow path and a part of an ink flow path ( (Energy chamber) or an energy generating element that is provided outside the substrate to generate energy used for ejecting ink. During recording, a small ink droplet is ejected from the orifice by the operation of the energy generating element. It is ejected and drops on the recording paper, and printing and recording are thereby performed. Such an inkjet head is disclosed in Japanese Patent Publication No. 42670/1990. The structure will be described with reference to FIGS. FIG. 11 is a schematic perspective view of the inkjet head. FIG. 13 is a cross-sectional view when cutting is performed at the position indicated by the alternate long and short dash line YY ′ in FIG. 11. Description will be made with reference to FIG. The substrate 1 is made of glass, plastic, ceramic, metal or the like, and functions as one of the wall surfaces of the ink flow path groove 9, the ink supply port groove 10, and the energy action chamber groove 11. In the manufacturing method, first, an energy generating element 2 that generates energy used for ejecting ink from the orifice 7 is arranged on the substrate 1.

Next, a photosensitive resin layer 4 is formed on the substrate 1 provided with the energy generating element 2. Next, the ink flow path groove 9, the ink supply port groove 10, and the energy action chamber groove 11 are collectively formed in the photosensitive resin layer 4 cured by a known photolithography means. Finally, each groove is covered with a cover plate 8 (hereinafter referred to as an orifice plate) on which the orifice 7 is formed to obtain an inkjet head.

In recent years, in order to obtain a high-definition printed matter, an ink jet head having a high density of orientations 7 is required. In that case, the space between the energy action chambers 11 is narrowed, and the width of the energy action chambers 11 is also reduced. Therefore, it is important to increase the height of the energy action chamber 11 in order to obtain the required pressure volume.
If the pressure volume is insufficient, the amount of ink at the time of ejecting ink will be small, and the area per recording dot on the recording medium will be small, and repeated striking or the like must be performed to obtain the required area. However, there are problems that the printing speed becomes slower, the ink supply to the energy action chamber 11 becomes unstable, and the ink ejection characteristics become unstable. If the photosensitive resin layer 4 is made thicker, the energy action chamber 11 can be made higher, but if it is made thicker, light does not uniformly reach from the upper surface to the bottom face of the photosensitive resin layer 4 at the time of exposure, and the dimensional accuracy of the energy action chamber 11 is deteriorated, and the ink The ejection characteristics become unstable. Therefore, in order to raise the energy action chamber 11 with high accuracy, the energy action chamber groove 11, the ink flow channel groove 9, and the ink supply port groove 10 are formed not only on the substrate 1 but also on the orifice plate 8 by the photosensitive resin layer 4, A method has been proposed in which the energy action chamber 11 is raised by joining with each groove on the substrate side. At this time, it is necessary to join them so that there is no positional deviation. In order to reduce the positional deviation, first, the ink flow path groove 9, the energy action chamber groove 11, and the ink supply port groove 10 of the photosensitive resin layer 4 are formed.
It is necessary to accurately arrange the substrate 1 and the orifice plate 8 at predetermined positions. As a method thereof, the exposure mask alignment reference hole 3 is provided in the substrate 1 and the orifice plate 8, and the substrate 1 and the alignment mask 3 are observed while observing the positional deviation between the reference hole 3 and the center of the exposure mask alignment mark 6 with an optical microscope or the like. A general method is to finely move the orientation plate 8 back and forth and left and right. Specifically, as shown in FIG. 10, the exposure mask alignment mark 6 has a shape including an arc slightly larger than the reference hole diameter and a circle smaller than the reference hole diameter. Align to. Next, in order to reduce the positional deviation, it is necessary to superpose and bond the substrate 1 and the orifice plate 8 with high accuracy.

[0005]

However, as shown in FIG. 11, since the exposure mask alignment reference hole 3a for exposure and the alignment reference hole 3b for bonding are separately provided,
Even if each groove is accurately arranged at a predetermined position with respect to the reference hole 3a at the time of exposure, the substrate 1 used at the time of exposure and the exposure mask alignment reference hole 3a of the orifice plate 8 and the alignment reference hole used at the time of bonding The distance variation with 3b is added at the time of joining, resulting in a large positional deviation (see FIG. 12). For this reason, there arises a problem that the ink flow path resistance becomes large and the ink ejection speed becomes slow.
In the future, the arrangement density of the orifice 7 will become higher and the ink flow path width will become narrower, and in particular, the positional deviation in this direction will greatly affect the ink ejection characteristics. In addition, there is a problem in that bubbles do not easily escape and ink is not ejected.

Further, when the energy application chamber 11 is raised or the shape is changed depending on the thickness, the photosensitive resin layer 4 becomes a multi-layer, so that the exposure mask alignment reference hole 3a at the time of exposure as shown in FIG. When the photosensitive resin layer 4 is formed, since the photosensitive resin layer 4 is colored, the visual field of the reference hole portion becomes dark, and the misalignment between the reference hole 3a and the mask alignment mark 6 is optical. There is also a problem that it is difficult to see with a microscope and it is not possible to perform accurate alignment. Therefore, man-hours are required and cost is increased.

The object of the present invention is to solve the above-mentioned problems, and it is possible to prevent the positional deviation of the ink flow path, the energy action chamber, and the ink supply port by a simple method, and to improve the stable ink ejection characteristics. It is to provide a density inkjet head at low cost.

[0008]

An ink jet head according to the present invention has an ink ejection port, an energy action chamber, an ink supply port, the ink ejection port, the energy action chamber and the ink supply port on a substrate and a cover plate. At least one wall surface of the communicating ink flow path is formed of a photosensitive resin, and has an energy generating element used for ejecting ink arranged corresponding to the ink flow path or the energy action chamber. In an inkjet head, a photosensitive resin layer is formed on a substrate and a cover plate that are provided with reference holes that serve as a reference for aligning and joining an exposure mask, and a photosensitive resin layer is formed except for the reference holes. Then, the ink ejection port, the energy application chamber, the ink supply port, and the ink flow path are formed at predetermined positions. Next, the substrate and the cover plate are aligned with each other and joined with the reference hole as a reference.

[0009]

The present invention will be described below with reference to specific examples, but the present invention is not limited thereto.

First, a method for manufacturing an ink jet head of the present invention will be described in detail with reference to the drawings. First, as shown in FIG. 1, during exposure and bonding to a substrate 1 made of an appropriate material such as glass, plastic, ceramic, metal, etc., on which an energy generating element 2 for ejecting ink such as a heating element or a piezoelectric element is provided. The alignment reference holes 3 are vertically or horizontally symmetrical with respect to the center of the substrate 1 and are provided at two positions apart from where the ink flow path, the energy action chamber and the ink supply port are formed. The hole is formed by a known method such as pressing or etching when the substrate is a metal.

Next, the surface of the substrate 1 is washed and dried, and then a photosensitive resin layer 4a is formed as shown in FIG.
At this time, the photosensitive resin layer 4a is not formed in the alignment reference hole 3. Alternatively, even if formed, the photosensitive resin layer 4a around the alignment reference hole 3 is removed to leave a cavity before exposure. As the photosensitive resin used here, a known photosensitive resin can be used regardless of whether it is liquid type or film type, positive type or negative type. The photosensitive resin layer can be formed by a known method such as a roll coater, a spin coater, a spray coater, or a hot pressure roller laminator. Among these, a method of laminating a dry film photoresist with a hot pressure roller laminator is preferable from the viewpoints of workability and uniformity of layer thickness. In this embodiment, a negative type dry film photoresist is used for the photosensitive resin layer.

Next, as shown in FIG. 3, the photosensitive resin layer 4a is formed.
The exposure mask 5 having a predetermined pattern is overlaid on the substrate, and the substrate 1 is finely moved back and forth and left and right while observing the positional deviation of the alignment reference hole 3 of the substrate and the alignment mark 6 of the exposure mask with an optical microscope or the like to minimize the displacement amount. Exposure is performed after adjusting to the limit. Through this step, the photosensitive resin layer 4a is divided into a cured portion (exposed portion) and a solubilized portion (unexposed portion).

Next, a new photosensitive resin layer 4b is formed on the photosensitive resin layer 4a which has undergone the exposure process in order to raise the energy action chamber. The method of forming the photosensitive resin layer 4b may be the same as the method of forming the photosensitive resin layer 4a formed in FIG.

Next, as shown in FIG. 4, exposure is performed by the same method as in FIG. At this time, as shown in FIG. 4, since the photosensitive resin layer 4 is not formed in the alignment reference hole 3 at the time of exposure, the reference hole 3 and the alignment mark 6 of the exposure mask.
Since the misaligned state of can be seen clearly with an optical microscope, it can be accurately adjusted in a short time. When a negative type photosensitive resin is used, the photosensitive resin layer 4a is doubly exposed, but attenuated light after reaction in the photosensitive resin layer 4b arrives and does not affect the dimensional accuracy. The steps of forming the photosensitive resin layer and exposing are repeated until the photosensitive resin layer 4 having a desired thickness is obtained, and then, as shown in FIG. After being dissolved and removed, an ink flow channel groove, an energy action chamber groove, and an ink supply port groove are obtained at predetermined positions with respect to the reference hole 3. As the developer, a known developer corresponding to the type of photosensitive resin can be used. FIG. 5 shows the case where the step of developing is performed after repeating the steps of forming the photosensitive resin layer and exposing three times.

Next, as shown in FIG. 6, an orifice plate 8 having an orifice 7 made of an appropriate material such as glass, plastic, ceramics, and metal is formed in the same process as the substrate (perforation, photosensitive resin layer). Coating, exposure, and development) to form the ink flow channel groove, the energy action chamber groove, and the ink supply port groove at predetermined positions with respect to the reference hole 3.

Next, as shown in FIG. 7, the substrate 1 having the ink flow path groove, the energy action chamber groove, and the ink supply port groove is formed.
And the orifice plate 8 are joined to obtain an ink flow path, an energy action chamber, and an ink supply port. As shown in FIG. 7, since the alignment reference hole 3 at the time of exposure is used as it is, the positional deviation amount of the ink flow path groove between the substrate 1 and the orifice plate 8 is
As in the conventional example, when the exposure mask alignment reference hole 3a of the substrate 1 and the orifice plate 8 used at the time of exposure and the bonding reference hole 3b used at the time of bonding are different from each other, the positional deviation due to the variation in the distance between the two holes is Does not occur.

FIG. 8 is a perspective view of the ink jet head obtained in this embodiment, and FIG. 9 is a sectional view of the ink jet head of FIG. The orifice 7 is on the orifice plate 8 and the energy generating element 2 is on the substrate 1.
The case where it is provided on the upper surface of FIG. The specific examples will be given below for comparison and comparison in more detail.

[Embodiment 1] First, a nickel substrate (10 m in length) provided with an energy generating element for ejecting ink.
m, width 30 mm) with a 1 mm diameter circular hole for alignment reference on the left and right on the center line in the vertical direction.
It is formed at a place by a pressing method with a hole distance of 28 mm.

Next, a negative type dry film photoresist (trade name "Audil", manufactured by Tokyo Ohka Kogyo Co., Ltd., thickness 55 μm, width 26 mm) is placed on a nickel substrate at a temperature of 80 to 100 ° C. using a hot pressure roller laminator. , 30 ~
Lamination is performed at a feed rate of 40 cm / min and a pressure of 1 to ³ kg / cm ² . The width of dry film photoresist is 26m, which is shorter than the distance (28mm) between two alignment reference holes.
Since m is used, the reference hole is not laminated and remains a cavity.

Then, while observing the positional deviation between the alignment reference hole and the center of the alignment mark of the exposure mask with an optical microscope, the nickel substrate is precisely aligned while finely moving back and forth and left and right. The alignment mark is slightly larger (1.002 mm) and smaller (0.998 m) than the reference hole diameter.
Since the shape includes the circular arc of m), the positioning is performed so that the reference hole is inserted between the two circular arcs.

Next, using an ultra high pressure mercury lamp, 70 mJ / c
Exposure is performed with a light amount of m ² . After this bonding and exposure are repeated a total of three times, 1,1,1-trichloroethane is sprayed using a spray to remove the unexposed portion, and the ink flow path groove and energy working chamber are provided in the center of the inside of the two reference holes. Obtain a groove and an ink supply port groove.

Next, a stainless steel substrate having an orifice is subjected to the same process as the nickel substrate (drilling, coating of the photosensitive resin layer, exposure, and development) with ink channel grooves, energy action chamber grooves, and ink supply port grooves as two criteria. It is formed in the center of the inside of the hole.

Next, the nickel substrate and the stainless steel substrate are aligned with the alignment reference hole at the time of exposure and the positioning pin of the bonding jig so that the ink flow channel groove, the energy action chamber groove and the ink supply port groove face each other. To do. Next, the nickel substrate and the stainless steel substrate which were overlapped with each other were bonded to each other at a temperature of 150 ° C. for 10 minutes using a bonding jig, and 470 g / cm ²
The ink flow path, energy action chamber, and
Get the ink supply port.

The ink jet head thus obtained has a deionized water: ethanol: glycerin: dye = 90:
When printing was performed using an inkjet ink composed of 4: 4: 2 (weight ratio), the ink ejection speed was 9 to 10.
m / sec and ink weight = 0.10 to 0.12 μg, and high-speed and high-density printing could be stably performed. Also,
The positional deviation of the ink flow path, the energy action chamber, and the ink supply port of the nickel substrate and the stainless steel substrate of the obtained inkjet head was about 5 μm.

[Comparative Example 1] First, a nickel substrate (10 m in length) provided with an energy generating element for ejecting ink.
m, horizontal 30 mm), circular holes dedicated to aligning the exposure mask are formed at two positions on the left and right symmetrically on the vertical centerline by a pressing method with a hole distance of 25 mm. At the same time, there are 2 round holes dedicated to positioning at the time of joining, each with a diameter of 1 mm.
It is formed by pressing without press at different places.

Next, a negative type dry film photoresist (trade name "Audyl", manufactured by Tokyo Ohka Kogyo Co., Ltd., thickness 55 μm, width 26 mm) is placed on a nickel substrate at a temperature of 80 to 100 ° C. using a hot pressure roller laminator. , 30 ~
Lamination is performed at a feed rate of 40 cm / min and a pressure of 1 to ³ kg / cm ² . Since the width (26 mm) of the dry film photoresist is wider than the distance (25 mm) between the two reference holes, the reference holes are laminated and closed.

Next, while observing the positional deviation between the alignment reference hole and the center of the alignment mark of the exposure mask with an optical microscope, the nickel substrate is precisely aligned while finely moving back and forth and left and right. The alignment mark is slightly larger (1.002 mm) and smaller (0.998 m) than the reference hole diameter.
Since the shape includes the circular arc of m), the positioning is performed so that the reference hole is inserted between the two circular arcs.

Next, using an ultra high pressure mercury lamp, 70 mJ / c
Exposure is performed with a light amount of m ² . After this bonding and exposure are repeated a total of three times, 1,1,1-trichloroethane is sprayed using a spray to remove the unexposed portion, and the ink flow path groove and energy working chamber are provided in the center of the inside of the two reference holes. Obtain a groove and an ink supply port groove.

Next, the stainless steel substrate having an orifice is formed in the same process as the nickel substrate (drilling, coating of the photosensitive resin layer, exposure, and development) with the ink flow channel groove, the energy action chamber groove, and the ink supply port groove as reference holes. It is formed in the center of the inside.

Next, the nickel substrate and the stainless steel substrate are aligned so that the ink flow channel groove, the energy action chamber groove, and the ink supply port groove face each other by the alignment reference hole at the time of exposure and the positioning pin of the bonding jig. To do. Next, the nickel substrate and the stainless steel substrate which were overlapped with each other were bonded to each other at a temperature of 150 ° C. for 10 minutes using a bonding jig, and 470 g / cm ²
The ink flow path, energy action chamber, and
Get the ink supply port.

The ink jet head thus obtained has a pure water: ethanol: glycerin: dye = 90:
Printing was performed using an inkjet ink having the same composition as in the example of 4: 4: 2 (weight ratio). Ink ejection speed = 5 to 10 m / sec, ink weight = 0.05 to
Since the amount was 0.12 μg, high-speed and high-density printing could be stably performed. In addition, the positional deviation of the ink flow path, the energy action chamber, and the ink supply port of the nickel substrate and the stainless steel substrate of the obtained inkjet head was about 15 μm.

As described above, in this embodiment, since the positional deviation is smaller by about 10 μm than the conventional example, the variation in ink ejection speed and ink weight is small.

[0033]

As described above, according to the method of manufacturing the ink jet head of the present invention, the photosensitive resin layer is formed on the substrate and the cover plate provided with the reference holes which serve as the reference of the exposure mask alignment, except the reference holes. After forming, exposing with reference to the reference hole, development is performed to form the ink discharge port, the energy action chamber, the ink supply port, and the ink flow path at predetermined positions. Next, the substrate and the cover plate are aligned and joined with the same reference hole as a reference. Therefore, the ink flow path, the energy action chamber,
The positional deviation of the ink supply port can be prevented by a simple method. Therefore, there is an advantage that a high-density inkjet head with stable ink ejection characteristics can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a perforated substrate showing a manufacturing process of an inkjet head according to the present invention.

FIG. 2 is a schematic cross-sectional view of a substrate on which a photosensitive resin layer is formed, showing a manufacturing process of an inkjet head according to the present invention.

3 is a schematic cross-sectional view of a substrate on which a photosensitive resin has been exposed by superimposing a mask on the photosensitive resin layer in the process subsequent to FIG. 2 showing a manufacturing process of an inkjet head according to the present invention.

FIG. 4 is a view showing a manufacturing process of an inkjet head according to the present invention, which is a substrate subsequent to the process shown in FIG. 3, in which a photosensitive resin is further formed on the exposed photosensitive resin, and then a mask is superposed and the photosensitive resin is exposed. 3 is a schematic cross-sectional view of FIG.

FIG. 5 is a schematic cross-sectional view of a first substrate, which shows a manufacturing process of an inkjet head according to the present invention, and which is repeatedly developed by repeatedly stacking and exposing a photosensitive resin to a desired thickness.

FIG. 6 is a schematic cross-sectional view of an orifice plate after development, showing a manufacturing process of an inkjet head according to the present invention.

FIG. 7 is a schematic cross-sectional view showing a manufacturing process of the inkjet head according to the present invention, which is a bonding process subsequent to FIG. 6;

FIG. 8 is a schematic perspective view of an inkjet head manufactured by the manufacturing method of the present invention.

9 shows an inkjet head manufactured by the manufacturing method of the present invention, and is a cross-sectional view when the inkjet head is cut at a position indicated by a chain line XX 'in FIG.

FIG. 10 is a schematic diagram of an exposure mask alignment method.

FIG. 11 is a schematic perspective view of an inkjet head manufactured by a conventional manufacturing method.

FIG. 12 is a schematic cross-sectional view of a joining process of an inkjet head manufactured by a conventional manufacturing method.

13 is a cross-sectional view showing an inkjet head manufactured by a conventional manufacturing method, and is a cross-sectional view taken along the chain line YY ′ in FIG. 11.

FIG. 14 is a schematic cross-sectional view showing a process of manufacturing an inkjet head according to the present invention, in which a photosensitive resin is further formed on the exposed photosensitive resin, and then a mask is overlaid to expose the photosensitive resin. is there.

[Explanation of symbols]

 1 substrate 2 energy generating element 3a, 3b alignment reference hole 4a, 4b photosensitive resin layer 5 exposure mask 6 exposure mask alignment mark 7 orifice 8 orifice plate 9 ink flow channel 10 ink supply port groove 11 energy action chamber groove 12 exposure pattern

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Claims (3)

[Claims] 1. An ink discharge port, an energy action chamber, an ink supply port, and at least one wall surface of an ink flow path communicating between the ink discharge port, the energy action chamber, and the ink supply port on a substrate and a cover plate. In an inkjet head having an energy generating element that is formed of a photosensitive resin and that is used for ejecting ink that is disposed corresponding to the ink flow path or the energy action chamber, the exposure of a substrate and a cover plate An ink jet head characterized in that a reference hole, which serves as a reference for alignment at the time of joining, is made hollow without forming a photosensitive resin layer. 2. The reference hole has a circular shape, and is vertically or horizontally symmetrical with respect to the center of the substrate and the cover plate, and is located at a position farther from a position where an ink flow path, an energy action chamber, and an ink supply port are formed. The ink jet head according to claim 1, wherein the ink jet head is provided at a position. 3. The method of manufacturing an inkjet head according to claim 1, wherein (a) a step of providing a reference hole as a reference for aligning the exposure mask on the substrate and the cover plate, and (b)
A step of forming a photosensitive resin layer on the substrate and the cover plate,
(C) exposing a required portion of the photosensitive resin layer to a predetermined position with reference to the reference hole; (d) removing an unexposed portion of the photosensitive resin layer; and (e) the substrate. A method for manufacturing an inkjet head, wherein the steps of aligning and covering the cover plate with the reference hole as a reference are performed in this order.