PHOTO-CURABLE RESIN COMPOSITION, METHOD OF PATTERNING THE SAME, AND INK JET HEAD AND METHOD OF FABRICATING THE SAME
A photo-curable resin composition, a method of patterning the same, an ink jet head, and a method of fabricating the same. The photo-curable resin composition includes an epoxy compound, a photo-catalyst provided as a photo-initiator, and a non-photo reactive solvent. The photo-catalyst may be a semiconductor material to generate electron-hall pairs using light energy. The semiconductor material is one selected from a group consisting of TiO2, CdS, Si, SrTiO3, WO, ZnO, SnO2, CdSe and CdTe, CdSe and CdTe. The epoxy compound may include a di-functional epoxy compound and a multi-functional epoxy compound. The non-photo reactive solvent may be one or a mixture selected from a group consisting of gamma-butyrolactone (GBL), cyclopentanone, C1-6 acetate, tetrahydrofurane (THF), and xylene. The photo-curable resin composition is patterned to form a fluid channel structure of the ink jet head.
This application is a divisional application of Ser. No. 11/004,939, filed Dec. 7, 2004, which claims the benefit of Korean Patent Application No. 2004-34430, filed May 14, 2004, the disclosure of which is hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present general inventive concept relates to a photo-curable resin composition, a method of patterning the photo-curable resin composition layer, and an ink jet head and method of fabricating the same and, more particularly, to a photo-curable resin composition including a photo-catalyst as a photo-initiator, a method of patterning a photo-curable resin layer made of the photo-curable resin composition, an ink jet head having the photo-curable resin layer, and a method of fabricating the same.
2. Description of the Related Art
An ink jet recording device functions to print an image by ejecting fine droplets of ink to a desired position of a recording medium. Such an ink jet recording device has been widely used since its price is low and numerous kinds of colors can be printed at a high resolution. The ink jet recording device basically includes an ink jet head for actually ejecting the ink and an ink container in fluid communication with the ink jet head. The ink stored in the ink container is supplied into the ink jet head through an ink channel, and the ink jet head ejects the ink supplied from the ink container to the recording medium to thereby complete a printing operation. An ink ejection type of the ink jet recording device is classified into an electro-thermal transducer type (hereinafter, referred to as “bubble-jet type”) ejecting the ink by generating bubbles in the ink using a heat source and an electro-mechanical transducer type ejecting the ink by controlling a change of an ink volume using deformation of a piezo-electric body used therein.
Referring to
In order to make the ink jet printer operate reliably and stably, each component disclosed hereinabove should satisfy predetermined conditions. In particular, the chamber plate 14 and the nozzle plate 20 should satisfy the following conditions as a structure for forming a fluid channel (hereinafter, referred to as “fluid channel structure”), in which the ink is moved and temporarily stored. That is, the chamber plate 14 and the nozzle plate 20 should have a high mechanical strength for maintaining a structural shape, the substrate 10 and other layers should have good adhesive properties, and the ink should have corrosion resistance properties. In addition, the chamber plate 14 and the nozzle plate 20 should have a fine structure so as to perform patterning, and should also have good photosensitivity and resolution for patterning the chamber plate 14 and the nozzle plate 20.
Research on a photo-curable resin composition as a material of a fluid channel structure satisfying the above-described conditions has been performed. For example, U.S. Pat. No. 4,623,676 discloses a photo-curable composition containing a polymerizable acrylic compound, a polymerizable epoxy functional silane, and a free radical aromatic complex salt photo-initiator. Further, U.S. Pat. No. 5,907,333 discloses a photo-curable resin composition containing a di-functional epoxy compound, a multi-functional epoxy compound, an aromatic complex salt photo-initiator and a non-photo reactive solvent.
Furthermore, U.S. Pat. No. 4,090,936, U.S. Pat. No. 5,478,606, etc., discloses various photo-curable resin compositions. However, none of the disclosed photo-curable resign compositions entirely satisfy the conditions described above. Therefore, the research on the fluid channel structure needs to be continuously performed to satisfy at least the above conditions.
SUMMARY OF THE INVENTIONIn order to solve the foregoing and/or other problems, it is an aspect of the general inventive concept to provide a photo-curable resin composition, which adopts a photo-catalyst as a photo-initiator, a method of patterning a photo-curable resin layer formed of the photo-curable resin composition, and an ink jet head having the photo-curable resin layer, and a method of fabricating the same.
Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
The foregoing and/or other aspects of the present general inventive concept may be achieved by providing a photo-curable resin composition including an epoxy compound, a photo-catalyst provided as a photo-initiator, and a non-photo reactive solvent. The photo-catalyst may be a material to generate electron-hole pairs. For example, the photo-catalyst may be one selected from a group consisting of TiO2, CdS, Si, SrTiO3, WO, ZnO, SnO2, CdSe and CdTe.
The epoxy compound may include a di-functional epoxy compound and a multi-functional epoxy compound. The non-photo reactive solvent may be one or a mixture selected from a group consisting of gamma-butyrolactone (GBL), cyclopentanone, C1-6 acetate, tetrahydrofurane (THF), and xylene.
In an aspect of the present general inventive concept, the photo-curable resin composition may include the epoxy compound of about 60 wt %, the photo-catalyst of about 2˜10 wt %, and the non-photo reactive solvent of about 10˜40 wt %.
The foregoing and/or other aspects of the present general inventive concept, may also be achieved by providing an ink jet head including a photo-curable resin layer made of a photo-curable resin composition. The ink jet head may include a substrate having a pressure-generating element to generate a pressure for ink ejection. A chamber plate formed by patterning the photo-curable resin layer including an epoxy compound, a photo-catalyst provided as a photo-initiator, and a non-photo reactive solvent can be disposed on the substrate, while a sidewall of a fluid channel through which the ink is moved is configured. A nozzle plate having a nozzle corresponding to the pressure-generating element can be disposed on the chamber plate. In another aspect of the present general inventive concept, the chamber plate and/or the nozzle plate may be a resin layer formed by patterning the novel photo-curable resin layer.
The foregoing and/or other aspects of the present general inventive concept may also be achieved by providing a method of fabricating the ink jet head, the method including preparing a substrate having a pressure-generating element to generate pressure for ink ejection, and forming on the substrate a chamber plate configuring a sidewall of a fluid channel, through which ink is moved, and a nozzle plate configuring an upper surface of the fluid channel and having a nozzle corresponding to the pressure-generating element, wherein at least the chamber plate can be formed by patterning a photo-curable resin layer including an epoxy compound, a photo-catalyst provided as a photo-initiator, and a non-photo reactive solvent. In an aspect of the present general inventive concept, the chamber plate and/or the nozzle plate may be formed by patterning the photo-curable resin layer.
In another aspect of the present general inventive concept, the method of fabricating the ink jet head may include patterning the photo-curable resin layer. The photo-curable resin layer may be patterned by a photolithography process. The patterning of the photo-curable resin layer may include forming the photo-curable resin layer on the substrate. The photo-curable resin layer can be selectively exposed using a photo-mask. Next, unexposed portions of the photo-curable resin layer can be removed.
BRIEF DESCRIPTION OF THE DRAWINGSThese and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIGS. 2 to 6 are cross-sectional views illustrating a method of fabricating an ink jet head in accordance with one embodiment of the present general inventive concept; and
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout the specification.
First, an ink jet head in accordance with an embodiment of the present general inventive concept will be described with reference to
Referring to
The ink supplied from an ink container, such as a cartridge (not shown), can pass through the ink supply hole 116 and the restrictor 120 sequentially to be temporarily stored in the ink chamber 118. The ink stored in the ink chamber 118 can be instantly heated by a heat-generating unit, i.e., the pressure-generating element 102, to be ejected in a shape of a droplet through the nozzles 114 by the pressure generated by the pressure-generating elements 102.
In an aspect of the present general inventive concept, the chamber plate 104′ and/or the nozzle plate 112 can be made of a novel photo-curable resin composition including a photo-catalyst as a photo-initiator. The photo-curable resin composition may include an epoxy compound, a photo-catalyst, and a non-photo reactive solvent. The photo-curable resin composition may include a photo-catalyst as a photo-initiator to induce a cross-link between epoxy compounds existing in a monomer or oligomer state.
Hereinafter, each component of the photo-curable resin composition will be described.
First, the epoxy compound may include a multi-functional epoxy compound and a di-functional epoxy compound. The multi-functional epoxy compound functions to increase cross-link density to improve resolution and solvent swelling. The multi-functional epoxy compound may be, for example, a novolac epoxy resin. The novolac epoxy resin is available from Dow Chemical Company, as a trade name entitled “D.E.N. 431”. The di-functional epoxy compound functions to add tensile strength and elastomeric properties to a resin layer. The di-functional epoxy compound may be, for example, diglycidyl ether bisphenol A, available from Shell Chemical Company, as a trade name entitled “EPON1010F, EPON828 or EPON1004”. In an aspect of the present general inventive concept, the epoxy compound including the multi-functional epoxy compound and the di-functional epoxy compound may have about 60 wt % with respect to a total weight of the resin composition.
The photo-catalyst can be provided as the photo-initiator to induce the cross-link between the epoxy compounds. The photo-catalyst may be a material to generate electron-hole pairs using light energy. In an aspect of the present general inventive concept, the photo-catalyst may be one selected from a group consisting of TiO2, CdS, Si, SrTiO3, WO, ZnO, SnO2, CdSe and CdTe. When the photo-catalyst is exposed by a light source having a wavelength equal to or less than 400 nm to be energized, electrons exiting in a valence band can be excited to a conduction band to generate the electron-hole pairs. The generated electron-hole pairs can be interacted with oxygen of an epoxy radical composing the epoxy compound, and the oxygen forming an epoxy ring may have a negative polarity compared to carbon, thus weakening a bonding strength between the oxygen and the carbon. As a result, a ring opening, in which one of two bondings between the oxygen and the carbon forming the epoxy ring is cut off, can be generated, and the carbon can be bonded to oxygen of another epoxy ring. The epoxy compound can be changed from a low molecular weight to a high molecular weight through the ring opening and the cross-link, and a high molecular chain can form a network structure to be cured. In this embodiment of the present general inventive concept, the photo-catalyst may have about 2˜10 wt % with respect to a total weight of the resin composition.
Next, the non-photo reactive solvent, which is capable of dissolving the epoxy compound and the photo-catalyst, may be, for example, one or a mixture selected from a group consisting of gamma-butyrolactone (GBL), cyclopentanone, C1-6 acetate, tetrahydrofurane (THF), and xylene. The non-photo reactive solvent may have about 10˜40 wt % with respect to the total weight of the resin composition. Besides, the photo-curable resin composition may add selective additives, such as silane coupling to improve adhesive properties, to the substrate and may also add a dye or surfactant to adjust an extinction coefficient of the photo-curable resin composition, to the substrate.
As described above, the ink jet head may have the chamber plate 104′ and/or the nozzle plate 112 made of the photo-curable epoxy resin composition including the photo-catalyst as the photo-initiator. Although the embodiment of the present general inventive concept has been described about the bubble-jet ink jet head employing a top shooting method, the present general inventive concept will not be limited thereto, and the photo-curable epoxy resin can be applied as materials for various fluid channel structures forming the fluid channel.
Hereinafter, a method of fabricating an ink jet head in accordance with another embodiment of the present general inventive concept will be described.
FIGS. 2 to 6 are cross-sectional views illustrating the method of fabricating the ink jet head according to another embodiment of the present general inventive concept.
Referring to
A photo-curable resin layer 104 can be formed on the substrate 100 having the pressure-generating elements 102. The photo-curable resin layer 104 may be formed by a spin coating method. The photo-curable resin layer 104 can be formed of the photo-curable resin composition including an epoxy compound, a photo-catalyst provided as a photo-initiator, a non-photo reactive solvent, and a selective additive as described above.
Referring to
After the chamber plate 104′ is formed, a process of forming a nozzle plate having a nozzle to eject the ink on the chamber plate 104′ is performed. The nozzle plate may be formed by various methods. For example, the nozzle plate may be formed of a metal, such as nickel, using an electro-forming, then may be attached to the chamber plate 104′. In an aspect of the present general inventive concept, the nozzle plate can be monolithically formed using the same material as the chamber plate 104′. Hereinafter, a method of monolithically forming the nozzle plate will be described.
Referring to
Referring to
Referring to
Referring to
As described above, the present general inventive concept may form the fluid channel structure forming the fluid channel of the ink jet head using the photo-curable resin composition including the photo-catalyst provided as the photo-initiator.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.
Claims
1. A photo-curable resin composition comprising:
- an epoxy compound;
- a photo-catalyst provided as a photo-initiator; and
- a non-photo reactive solvent.
2. The photo-curable resin composition according to claim 1, wherein the photo-catalyst comprises a semiconductor material to generate electron-hall pairs using light energy.
3. The photo-curable resin composition according to claim 2, wherein the photo-catalyst comprises one selected from a group consisting of TiO2, CdS, Si, SrTiO3, WO, ZnO, SnO2, CdSe and CdTe.
4. The photo-curable resin composition according to claim 2, wherein the epoxy compound comprises a di-functional epoxy compound and a multi-functional epoxy compound.
5. The photo-curable resin composition according to claim 4, wherein the epoxy compound has about 60 wt %, the photo-catalyst has about 2˜10 wt %, and the non-photo reactive solvent has about 10˜40 wt %.
6. The photo-curable resin composition according to claim 2, wherein the non-photo reactive solvent comprises one or a mixture selected from a group consisting of gamma-butyrolactone (GBL), cyclopentanone, C1-6 acetate, tetrahydrofurane (THF), and xylene.
7. A method of patterning a photo-curable resin layer, comprising:
- forming a photo-curable resin layer on a substrate, the photo-curable resin layer including an epoxy compound, a photo-catalyst provided as a photo-initiator, and a non-photo reactive solvent;
- selectively exposing the photo-curable resin layer using a photo-mask; and
- removing an unexposed portion of the photo-curable resin layer.
8. The method according to claim 7, wherein the photo-catalyst comprises a semiconductor material to generate electron-hall pairs by means of light energy.
9. The method according to claim 8, wherein the photo-catalyst comprises one selected from a group consisting of TiO2, CdS, Si, SrTiO3, WO, ZnO, SnO2, CdSe and CdTe.
10. The method according to claim 8, wherein the epoxy compound comprises a di-functional epoxy compound and a multi-functional epoxy compound.
11. The method according to claim 10, wherein the photo-curable resin layer comprises the epoxy compound of about 60 wt %, the photo-catalyst of about 2˜10 wt %, and the non-photo reactive solvent of about 10˜40 wt %.
12. The method according to claim 8, wherein the non-photo reactive solvent comprises one or a mixture selected from a group consisting of gamma-butyrolactone (GBL), cyclopentanone, C1-6 acetate, tetrahydrofurane (THF), and xylene.
13. A method of fabricating an ink jet head comprising:
- preparing a substrate having a pressure-generating element to generate a pressure for ink ejection; and
- forming on the substrate a chamber plate to configure a sidewall of a fluid channel through which ink is moved, and a nozzle plate to configure an upper surface of the fluid channel and having a nozzle corresponding to the pressure-generating element,
- wherein at least one of the chamber plate and the nozzle plate is formed by patterning a photo-curable resin layer including an epoxy compound, a photo-catalyst provided as a photo-initiator, and a non-photo reactive solvent.
14. The method according to claim 13, wherein the photo-catalyst comprises a semiconductor material to generate electron-hall pairs using light energy.
15. The method according to claim 14, wherein the photo-catalyst comprises one selected from a group consisting of TiO2, CdS, Si, SrTiO3, WO, ZnO, SnO2, CdSe and CdTe.
16. The method according to claim 14, wherein the epoxy compound comprises a di-functional epoxy compound and a multi-functional epoxy compound.
17. The method according to claim 16, wherein the photo-curable resin layer comprises the epoxy compound of about 60 wt %, the photo-catalyst of about 2˜10 wt %, and the non-photo reactive solvent of about 10˜40 wt %.
18. The method according to claim 13, wherein the forming of the chamber plate and the nozzle plate comprises:
- forming the nozzle plate using another photo-curable resin layer, so that the chamber plate and the nozzle plate are formed in a monolithic single body.
19. The method according to claim 13, wherein the forming of the chamber plate and the nozzle plate comprises:
- forming the photo-curable epoxy resin layer on the substrate to form both the nozzle plate and the chamber plate.
20. The method according to claim 19, wherein the forming of the photo-curable epoxy resin layer comprises selectively exposing the photo-curable epoxy resin layer to change a state of the epoxy compound using a characteristic of the photo-catalyst.
21. The method according to claim 19, wherein the forming of the chamber plate and the nozzle plate comprises:
- exposing the photo-curable resin layer to a light source so that the photo-catalyst induces a cross-link and a ring opening relating to the epoxy compound.
22. The method according to claim 21, wherein the exposing of the photo-catalyst to the light source comprises:
- changing the epoxy compound between a low molecular chain and a high molecular chain so that the epoxy compound is cured to a network structure.
Type: Application
Filed: Sep 6, 2007
Publication Date: Mar 13, 2008
Inventors: Byung-Ha Park (Suwon-si), Young-ung Ha (Suwon-si), Sung-joon Park (Suwon-si), Myong-jong Kwon (Suwon-si)
Application Number: 11/850,938
International Classification: G03C 1/04 (20060101); G03C 5/00 (20060101);