Patent Application
20060109315
1. Field of the Invention
The present invention relates to a method of manufacturing a liquid discharge head which discharges a liquid, and a liquid discharge head, more particularly to an ink jet recording head which discharges ink to perform recording, and a method of manufacturing the ink jet recording head.
2. Related Background Art
As an ink jet recording head which discharges ink to perform recording, there is known a constitution (“side shooter type recording head”) in which an ink droplet is discharged in a direction vertical to a substrate on which there is formed an ink discharge energy generating element such as a heat generating resistor.
The following method is known as a method of manufacturing such side shooter type recording head.
In U.S. Pat. No. 5,4781606, there is disclosed a method of manufacturing an ink jet recording head, including the following steps. First, an ink flow path pattern is formed of a soluble resin on the substrate on which the ink discharge energy generating element is formed. Subsequently, a coating resin containing a solid epoxy resin is dissolved in a solvent at ordinary temperature, and a soluble resin layer is coated with a solvent to thereby form the coating resin layer constituting an ink flow path wall on the soluble resin layer. Moreover, an ink discharge port is formed in the coating resin layer above an ink discharge pressure generating element to elute the soluble resin layer.
Moreover, in U.S. Pat. No. 5,331,344, there is disclosed a method of manufacturing an ink jet recording head, including the following steps. First, a first photosensitive material layer for forming an ink oath is disposed on the substrate on which the ink discharge energy generating element is formed to subject the first photosensitive material layer to pattern exposure for forming the ink path. Subsequently, a second photosensitive material layer is further disposed on the first photosensitive material layer to subject the second photosensitive material layer to exposure of a pattern for forming the ink discharge port and an ink supply port. Thereafter, the first and second photosensitive material layers are developed.
On the other hand, in U.S. Pat. No. 5,278,584, there is disclosed a method of manufacturing an ink jet recording head, in which an orifice plate member is laminated on a member integrated with the substrate provided with the ink discharge energy generating element and constituting an ink flow path wall. The orifice plate member is constituted of a flexible circuit substrate material, and a thermosetting adhesive or the like is used in laminating the orifice plate member on the ink flow path wall.
However, the above-described ink jet recording heads have the following problems, respectively.
That is, in the method disclosed in U.S. Pat. No. 5,478,606, since the substrate on which the ink flow path pattern is formed is coated with the solvent to form the coating resin layer constituting the ink flow path wall, the coating resin layer extends along the ink flow path pattern. Therefore, in the ink jet recording head manufactured by this method, fluctuations are generated in a thickness of an orifice plate to form thick and thin portions, and there might occur a problem in a reliability of the thin portion of the orifice plate depending on use conditions.
In the method disclosed in U.S. Pat. No. 5,331,344, the above-described fluctuations of the film thickness are not generated, but there is a possibility that a mutually dissolved layer of the respective materials is generated in a boundary surface between a latent image pattern upper layer portion of the first photosensitive material layer and the second photosensitive material layer. Since this mutually dissolved layer remains even after the development of the first and second photosensitive material layers, a discharge control itself of the ink jet recording head might be adversely influenced.
On the other hand, in the method disclosed in U.S. Pat. No. 5,278,584, the above-described problems due to the film thickness fluctuations and the mutually dissolved layer are not generated. However, since the orifice plate member provided with the ink discharge port is laminated on the member constituting the ink flow path wall, there is a possibility that a problem is generated in a precision in positioning the members. In a case where a deviation is generated, a discharge direction of the ink droplet deviates from a desired direction, and it accordingly becomes difficult to perform high-precision printing/recording. In recent years, it has been demanded that in the ink jet-recording head, a discharge amount be reduced in order to realize a picture quality, and an arrangement density of the discharge ports be increased, but it is difficult to satisfy such requirement by the method disclosed in U.S. Pat. No. 5,278,584.
The present invention has been developed in view of the above-described problems. An object of the present invention is to form an orifice plate to be flat while forming an ink discharge port in a substrate with a satisfactory positional precision, and to provide an ink jet recording head capable of performing printing and recording with a high precision and having a high reliability, and a method of manufacturing the ink jet recording head.
To achieve the above-described object, according to one aspect of the present invention, there is provided a method of manufacturing a liquid discharge head, comprising: a first photosensitive material layer forming step of forming a layer constituted of a first photosensitive material on a first substrate having a liquid discharge energy generating element which generates energy for discharging a liquid; a latent image forming step of performing pattern exposure on the first photosensitive material layer to form a latent image of a flow path pattern; a second substrate laminating step of laminating a flat second substrate constituted of an inorganic material on the photosensitive material layer on which the latent image has been formed; a discharge port forming step of forming a discharge port in the second substrate; and a flow path forming step of developing the pattern which has been formed in the latent image forming step and which is to constitute a flow path, and forming the flow path.
Moreover, according to another aspect of the present invention, there is provided a method of manufacturing a liquid discharge head, comprising: a mold forming step of forming, exposing, and developing a second photosensitive resin layer which is to constitute a mold of an ink flow path on a first substrate having a liquid discharge energy generating element which generates energy for discharging a liquid, and forming the mold which is to constitute a part of the ink flow path; a first photosensitive material layer forming step of forming a layer constituted of a first photosensitive material on the first substrate on which the mold of the ink flow path has been formed; a latent image forming step of performing pattern exposure on the first photosensitive material layer to form a latent image pattern which is to constitute a part of the flow path; a second substrate laminating step of laminating a flat second substrate constituted of an inorganic material on the photosensitive material layer on which the latent image has been formed; a discharge port forming step of forming a discharge port in the second substrate; and a flow path forming step of developing the latent image pattern which has been formed in the latent image forming step and which is to constitute a part of the flow path, and removing the pattern together with the mold formed in the mold forming step to form the flow path.
According to the above-described manufacturing method, the following effects can be produced.
1) Since the flat orifice plate constituted of the inorganic substrate is formed, a distance between the surface of the orifice plate and a heat generating resistor is kept to be constant, and ink droplet discharge properties of the ink jet recording head becomes very satisfactory.
2) The ink discharge port can be formed with a positioning precision by use of photolithography after laminating the orifice plate. Therefore, it is possible to provide the recording head whose ink discharge performance has been rapidly enhanced as compared with a method of forming the ink discharge port before laminating the plate.
3) Since the inorganic substrate made of silicon or the like is used in the orifice plate, a resin is not swollen owing to a ink liquid. The resin swelling is heretofore feared during use of the ink jet recording head. It is possible to provide the recording head having a high reliability even during long-term use.
4) The ink flow path made of the resin (photosensitive material) is formed between the substrate on which the heat generating resistor has been formed and the substrate which is to constitute the orifice plate. Therefore, the resin also functions as a bonding layer between the two substrates, and another adhesive layer for exclusive use is not required for a nozzle member. Therefore, there can be provided the manufacturing method which is capable of reducing manufacturing costs of the recording head.
5) Since the inorganic substrate is used in the orifice plate, it is not necessary to form any special ink-repellent layer that has been adopted in the conventional resin-made orifice plate.
6) Since the ink flow path is made of the resin, degrees of freedom in shape design and preparation are rapidly enhanced as compared with a case where the ink flow path is constituted of the inorganic substrate only. Therefore, the ink droplet discharge performance can be easily controlled.
Embodiments of the present invention will be described hereinafter in detail with reference to the drawings.
It is to be noted that in the following description, portions having the same function are denoted with the same reference numerals, and description thereof is omitted. An ink jet recording head will be described hereinafter which jets ink to form a flying droplet and perform recording, but the present invention is not limited to a device which performs the recording. The present invention is applicable to a liquid discharge head which discharges a liquid, for use in, for example, preparing an electric wiring line, manufacturing a color filter, or preparing a DNA chip.
First, a method of manufacturing an ink jet recording head will be described according to the present invention with reference to
First, in the present embodiment, the desired number of ink discharge energy generating elements 1 such as heat generating resistors (electrothermal conversion elements) are arranged on a substrate 2 shown in
Next, as shown in
Here, a silicon substrate (thin silicon substrate 4) which is to constitute an orifice plate and which has been worked to be thin is laminated on the photosensitive material layer 3 (
Next, ink discharge ports 6 are formed in portions of the thin silicon substrate 4 which are positioned vertically above the ink discharge energy generating elements 1. First, as shown in
Moreover, as shown in
Thereafter, as shown in
Furthermore, the latent image pattern 30 formed in the step 5 hown in
The substrate 2 on which a nozzle portion has been prepared by the above-described steps is separated and cut into chips with a dicing saw or the like. Moreover, after performing electric bonding (not shown) for driving the ink discharge energy generating elements 1, a chip tank member for ink supply is connected, and the ink jet recording head is completed.
According to the above-described steps, since the ink discharge ports are formed after laminating the substrate which is to constitute the orifice plate, the ink discharge ports can be formed using an aligner or the like with a high positional precision.
Moreover, since silicon is used in the substrate that is to constitute the orifice plate, the substrate is not influenced by swelling by ink, peeling or the like, and the substrate is also provided with a liquid-repellent performance of the surface of the orifice plate which largely influences the ink discharge.
Next, a method of manufacturing another liquid discharge head of the present invention will be described with reference to
Next, as shown in
Here, a silicon substrate 4 which is to constitute an orifice plate and which has been worked to be thin is laminated on the photosensitive material layer 3 (
Next, ink discharge ports 6 are formed in portions of the thin silicon substrate 4 which are disposed vertically above the ink discharge energy generating elements 1. To form the ink discharge ports 6, first, as shown in
Moreover, as shown in
Furthermore, the latent image pattern 30 formed in the step shown in
According to the above-described steps, an effect similar to that of the first embodiment is obtained. In addition, since the ink flow path can be formed into a three-dimensional structure, there can be provided the recording head whose ink droplet discharge efficiency has been enhanced as compared with an ink jet recording head having a conventional constitution.
The present invention will be more specifically described hereinafter in accordance with two examples of each embodiment.
In Example 1, an ink jet recording head was prepared in accordance with the above-described procedure shown in
Moreover, a radical polymerized material of methacrylate anhydride was used in a photosensitive material layer 3 in
Next, as shown in
Subsequently, alignment required for forming ink discharge ports 6 in the thin silicon substrate 4 was performed with respect to the silicon substrate 2. To be more specific, as shown in
A method of forming the through ports 23 conforms to that of forming the ink discharge ports 6 described later. That is, a photo resist 5 (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was formed into a thickness of 1 μm on the thin silicon substrate 4. Moreover, patterns of the through ports 23 which were to constitute the windows for observing the alignment marks were formed at a ratio of 100 mJ/cm2 with an exposure device “model number MPA-600 Super” manufactured by Cannon Inc. in an exposing and developing step. This through port pattern may be sufficiently formed into a pattern which opens to be smaller than the region 21 provided with an alignment mark 22 on the substrate 2 and broader than the alignment mark 22 of the substrate 2 with a mechanical pre-alignment precision of the aligner. Furthermore, silicon was dry-etched by use of “Alcatel Micro Machining System 200” which was an ICP dry etcher manufactured by Alcatel Inc., and the through ports 23 which were to constitute the windows for observing the alignment marks were formed as shown in
Moreover, as shown in
Here, as shown in
Furthermore, after peeling the photo resist 5 as an etching-resistant mask, and forming an alkali-resistant protective member (not shown) on the thin silicon substrate 4, as shown in
Subsequently, when the latent image pattern 30 of the photosensitive material layer 3 was developed and eluted with methyl isobutyl ketone, an ink flow path 15 was formed as shown in
Moreover, the photosensitive material layer 3 was heat-cured in an oven at 250° C. for 60 minutes, and the substrate provided with a nozzle member was completed.
Finally, the substrate 2 on which the nozzle portion was prepared by the above-described steps was separated and cut into chips with a dicing saw or the like, and electrically bonded (not shown) in order to drive the ink discharge energy generating elements 1. Thereafter, a chip tank member for ink supply was connected, and the ink jet recording head was completed.
As a result of printing and recording with ink droplets discharged from the ink jet recording head prepared in Example 1, very high quality printing was achieved.
Furthermore, as a result of the printing and recording at 7.5% duty per A4-size sheet in the recording head of Example 1, even when the number of the printed sheets exceeded 8000 sheets, discharge properties were not deteriorated, and satisfactory printing and recording were achieved.
In Example 2, an ink jet recording head was prepared in accordance with a procedure shown in
Moreover, in a final step, the layer was heat-cured in an oven at 200° C. for 60 minutes.
As a result of printing and recording performed with ink droplets discharged from the ink jet recording head prepared in Example 2, very high quality printing was achieved.
Furthermore, as a result of the printing and recording performed at 7.5% duty per A4-size sheet in, the recording head of Example 2, even when the number of the printed sheets exceeded 8000 sheets, discharge properties were not deteriorated, and satisfactory printing and recording were achieved.
In Example 3, an ink jet recording head was prepared in accordance with a procedure shown in
Moreover, in
Subsequently, the ink flow path pattern 41 was solvent-coated with a photosensitive material layer 3 constituted of a composition of Table 2 (
In this case, the film was formed into a thickness of 5 μm on the ink flow path pattern 41, so that a total film thickness was 15 μm. Moreover, as shown in
Next, as shown in
Subsequently, in order to perform alignment required for forming ink discharge ports 6 in the thin silicon substrate 4 with respect to the silicon substrate 2, as shown in
Moreover, as shown in
Here, the ink discharge ports 6 were formed by dry-etching silicon by use of Alcatel Micro Machining System 200 as shown in
Furthermore, after peeling the photosensitive material layer 5 as an etching-resistant mask, and forming an alkali-resistant protective member 52 on the thin silicon substrate 4, as shown in
After peeling the alkali-resistant protective member 52. (
Finally, the layer was heat-cured in an oven at 200° C. for 60 minutes, and the substrate provided with a nozzle member was completed. Furthermore, the substrate 2 on which the nozzle portion was prepared by the above-described steps was separated and cut into chips with a dicing saw or the like, and electrically bonded (not shown) in order to drive the heat generating resistors 1. Thereafter, a chip tank member for ink supply was connected, and the ink jet recording head was completed.
As a result of printing and recording performed with ink droplets discharged from the ink jet recording head prepared in Example 3, very high quality printing was achieved.
Furthermore, as a result of the printing and recording performed at 7.5% duty per A4-size sheet in the recording head of Example 3, even when the number of the printed sheets exceeded 8000 sheets, discharge properties were not deteriorated, and satisfactory printing and recording were achieved.
In Example 4, an ink jet recording head was prepared in accordance with a procedure shown in
First, in
Subsequently, in
Diethylene glycol monobutyl ether 60 vol %;
Ethanol amine 5 vol %;
Morpholine 20 vol %;. and
Ion exchange water 15 vol %.
Furthermore, as shown in
Thereafter, a photosensitive material layer 3 (constituted of the same composition as that of the photosensitive material layer 3 described in Example 1) was formed (
Moreover, finally, the ink jet recording head of Example 4 was completed by performing heat-curing in an oven at 200° C. for 60 minutes, chip cutting, electric-bonding and the like.
As a result of printing and recording performed with ink droplets discharged from the ink jet recording head prepared in Example 4, very high quality printing was achieved.
Furthermore, as a result of the printing and recording performed at 7.5% duty per A4-size sheet in the recording head of Example 4, even when the number of the printed sheets exceeded 8600 sheets, discharge properties were not deteriorated, and satisfactory printing and recording were achieved.
This application claims priority from Japanese Patent Application No. 2004-337301 filed on Nov. 22, 2004, which is hereby incorporated by reference herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-337301 | Nov 2004 | JP | national |
