U.S. patent application number 11/850938 was filed with the patent office on 2008-03-13 for photo-curable resin composition, method of patterning the same, and ink jet head and method of fabricating the same.
Invention is credited to Young-ung Ha, Myong-jong Kwon, Byung-Ha Park, Sung-joon Park.
Application Number | 20080063978 11/850938 |
Document ID | / |
Family ID | 35309828 |
Filed Date | 2008-03-13 |
United States Patent
Application |
20080063978 |
Kind Code |
A1 |
Park; Byung-Ha ; et
al. |
March 13, 2008 |
PHOTO-CURABLE RESIN COMPOSITION, METHOD OF PATTERNING THE SAME, AND
INK JET HEAD AND METHOD OF FABRICATING THE SAME
Abstract
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
TiO.sub.2, CdS, Si, SrTiO.sub.3, WO, ZnO, SnO.sub.2, 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.
Inventors: |
Park; Byung-Ha; (Suwon-si,
KR) ; Ha; Young-ung; (Suwon-si, KR) ; Park;
Sung-joon; (Suwon-si, KR) ; Kwon; Myong-jong;
(Suwon-si, KR) |
Correspondence
Address: |
STANZIONE & KIM, LLP
919 18TH STREET, N.W.
SUITE 440
WASHINGTON
DC
20006
US
|
Family ID: |
35309828 |
Appl. No.: |
11/850938 |
Filed: |
September 6, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11004938 |
Dec 7, 2004 |
|
|
|
11850938 |
Sep 6, 2007 |
|
|
|
Current U.S.
Class: |
430/280.1 ;
430/320; 430/322 |
Current CPC
Class: |
G03F 7/0048 20130101;
G03F 7/038 20130101; B41J 2/1603 20130101; B41J 2/1631 20130101;
G03F 7/0043 20130101 |
Class at
Publication: |
430/280.1 ;
430/320; 430/322 |
International
Class: |
G03C 1/04 20060101
G03C001/04; G03C 5/00 20060101 G03C005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 14, 2004 |
KR |
2004-34430 |
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 TiO.sub.2, CdS, Si, SrTiO.sub.3, WO, ZnO, SnO.sub.2,
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.about.10 wt %, and the non-photo reactive solvent has
about 10.about.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 TiO.sub.2, CdS,
Si, SrTiO.sub.3, WO, ZnO, SnO.sub.2, 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.about.10 wt %, and the non-photo reactive
solvent of about 10.about.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 TiO.sub.2, CdS,
Si, SrTiO.sub.3, WO, ZnO, SnO.sub.2, 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.about.10 wt %, and the non-photo reactive
solvent of about 10.about.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.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] 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 INVENTION
[0002] 1. Field of the Invention
[0003] 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.
[0004] 2. Description of the Related Art
[0005] 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.
[0006] FIG. 1 is a perspective view illustrating a conventional
bubble-jet ink jet head disclosed in U.S. Pat. No. 4,882,595.
[0007] Referring to FIG. 1, the bubble-jet ink jet print head
includes a substrate 10, a chamber plate 14 disposed on the
substrate 10 to form an ink chamber 12 for receiving the ink, a
heat-generating resistor 16 disposed in the ink chamber 12, and a
nozzle plate 20 having a nozzle 18 for ejecting the ink. The ink is
filled in the ink chamber 12 through a restrictor 22, and also
filled in the nozzle 18 in fluid communication with the ink chamber
12 using a capillary phenomenon. When the heat-generating resistor
16 is energized, the heat-generating resistor 16 generates heat to
form bubbles in the ink filled in the ink chamber 12. As the
bubbles are expanded, the ink filled in the ink chamber 12 is
pressurized to eject the ink through the nozzle 18.
[0008] 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.
[0009] 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.
[0010] 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 INVENTION
[0011] In 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.
[0012] 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.
[0013] 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 TiO.sub.2, CdS, Si, SrTiO.sub.3, WO, ZnO,
SnO.sub.2, CdSe and CdTe.
[0014] 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.
[0015] 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.about.10 wt %, and the
non-photo reactive solvent of about 10.about.40 wt %.
[0016] 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.
[0017] 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.
[0018] 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 DRAWINGS
[0019] These 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:
[0020] FIG. 1 is a perspective view illustrating a conventional
bubble-jet ink jet print head;
[0021] 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
[0022] FIGS. 7 and 8 are cross-sectional views illustrating a
method of fabricating an ink jet head in accordance with another
embodiment of the present general inventive concept.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] 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.
[0024] First, an ink jet head in accordance with an embodiment of
the present general inventive concept will be described with
reference to FIG. 6.
[0025] Referring to FIG. 6, pressure-generating elements 102 to
generate pressure for ink ejection can be disposed on a substrate
100. The substrate 100 can be a silicone substrate having a
thickness of about 500 .mu.m. It is effective in mass production
since the silicone substrate widely used in manufacturing a
semiconductor device can be used as it is. The
pressure-generating-elements 102 may be a heat-generating resistor
made of a high-resistance metal such as a tantalum-aluminum alloy.
A chamber plate 104' can be disposed on the substrate having the
pressure-generating elements 102. The chamber plate 104' configures
a sidewall of a fluid channel including a pressure chamber 118 and
a restrictor 120. A nozzle plate 112 having nozzles 114
corresponding to the pressure-generating elements 102 can be
disposed on the chamber plate 104'. An ink supply hole 116 passing
through the substrate 100 can be disposed on a center portion of
the substrate 100.
[0026] 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.
[0027] 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.
[0028] Hereinafter, each component of the photo-curable resin
composition will be described.
[0029] 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.
[0030] 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 TiO.sub.2, CdS, Si, SrTiO.sub.3, WO, ZnO, SnO.sub.2,
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.about.10 wt % with
respect to a total weight of the resin composition.
[0031] 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.about.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.
[0032] 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.
[0033] Hereinafter, a method of fabricating an ink jet head in
accordance with another embodiment of the present general inventive
concept will be described.
[0034] 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.
[0035] Referring to FIG. 2, a substrate 100 can be prepared. The
substrate 100 may be a silicone substrate used in a process of
manufacturing a semiconductor device. Pressure-generating elements
102 are formed on the substrate 100. In an aspect of the present
general inventive concept, the pressure-generating elements 102 may
be a heat-generating resistor made of a high-resistance metal, such
as a tantalum-aluminum alloy. Besides, interconnection lines to
supply electrical signals to the pressure-generating elements 102,
a conductive pad to electrically connect the pressure-generating
elements 102 to an external circuit, a silicone oxide heat barrier
layer to cover the substrate 100, and a passivation layer to
protect the above structures may be formed on the substrate 100. A
formation method and a material of the structures including the
pressure-generating elements 102 will not be intended to limit the
scope of the present general inventive concept, and it will be
understood that the method and the material can be variously
modified by technologies known to those skilled in the art.
Therefore, their descriptions will be omitted.
[0036] 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.
[0037] Referring to FIG. 3, the photo-curable resin layer 104 can
be patterned to form a chamber plate 104' configuring a sidewall of
a fluid channel through which the ink is moved. That is, the
chamber plate 104' can be formed by patterning the photo-curable
resin layer 104. The photo-curable resin layer 104 may be patterned
by a photolithography process. More specifically, first, the
photo-curable resin layer 104 is formed, and then a soft baking
operation can be performed on the photo-curable resin layer 104 at
low temperature in order to remove a solvent ingredient. Next, the
photo-curable resin layer 104 can be selectively exposed using a
first photo-mask 106 provided with a fluid channel pattern. UV or
DUV (deep ultra violate) having a wavelength equal to or less than
400 nm, for example, I-line having a wavelength of about 365 nm,
KrF laser having a wavelength of about 248 nm, or ArF laser having
a wavelength of about 193 nm, may be employed as a light source hv
during the exposure operation. As a result of the exposure
operation, an exposed portion of the photo-curable resin layer 104
can be cross-linked by the photo-catalyst added as the
photo-initiator to thereby be cured. An unexposed portion of the
photo-curable resin layer 104 can still exist in a low molecular
state, for example, a monomer or oligomer state. Then, the
unexposed portion of the photo-curable resin layer 104 can be
removed. The unexposed portion of the photo-curable resin layer 104
may be easily removed using, for example, a solvent consisting of a
developer, acetone, a halogen element, or an alkaline solvent. As a
result, as shown in FIG. 3, the chamber plate 104' can be formed on
the substrate 100. In the meantime, before the unexposed portion is
removed, a post-exposure bake operation may be selectively
performed. The post-exposure bake operation may be performed at a
temperature of about 60.about.95.degree. C. in order to further
cure the photo-curable resin layer 104 at the exposed portion.
[0038] 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.
[0039] Referring to FIG. 4, a positive photo-resist can be formed
to fill a space between the chamber plates 104' so that the chamber
plate 104' is covered on an entire surface of the substrate 100
having the chamber plate 104'. After that, a planarization process,
such as a chemical mechanical polishing (CMP) process, can be
performed to expose an upper surface of the chamber plate 104' to
thereby form a sacrificial mold layer 108 filling between the
chamber plates 104'. In the meantime, a thickness of the chamber
plate 104' may be somewhat decreased while performing the CMP
process.
[0040] Referring to FIG. 5, a nozzle material layer can be formed
on an entire surface of the chamber plate 104' and the sacrificial
mold layer 108. The nozzle material layer may be formed of the
photo-curable epoxy resin composition, which is the same material
as the chamber plate 104'. After that, the nozzle material layer
formed of the photo-curable epoxy resin composition can be
patterned. The patterning of the nozzle material layer can be
similar to the process of forming the chamber plate 104' described
above. Briefly describing, the nozzle material layer can be exposed
to a light source hv using a second photo-mask 110 provided with a
nozzle pattern. After that, an unexposed portion of the nozzle
material layer can be removed using the solvent. As a result, as
shown in FIG. 5, a nozzle plate 112 having nozzles 114
corresponding to the pressure-generating elements 102 can be
formed.
[0041] Referring to FIG. 6, the substrate 100 can be etched to form
an ink supply hole 116 passing through the substrate 100, and then
the sacrificial mold layer 108 can be removed using an appropriate
solvent. As a result, the fluid channel including the ink chamber
118 and the restrictor 120 can be formed at a region where the
sacrificial mold layer 108 is removed.
[0042] FIGS. 7 and 8 are cross-sectional views illustrating a
method of fabricating an ink jet head in accordance with another
embodiment of the present general inventive concept. In an aspect
of the present general inventive concept, a chamber plate and a
nozzle plate may be simultaneously formed by one photolithography
process.
[0043] Referring to FIGS. 7 and 8, a sacrificial mold layer 304 can
be formed on a substrate 300 provided with pressure-generating
elements 302. The sacrificial mold layer 304 may be formed by
patterning a positive photo-resist using a photolithography
process. The sacrificial mold layer 304 is formed on the substrate
300 to cover a region where a fluid channel is to be formed. Next,
a photo-curable epoxy resin layer covering the sacrificial mold
layer 304 can be formed on the substrate having the sacrificial
mold layer 304. As described above, the photo-curable epoxy resin
layer may include an epoxy compound, a photo-catalyst provided as a
photo-initiator, and a non-photo reactive solvent. Next, as shown
in FIG. 8, the photo-curable epoxy resin layer can be exposed to a
light source hv using a photo-mask 304 provided with a nozzle
pattern. As a result, a fluid channel structure 306 having nozzles
308 corresponding to the pressure-generating elements 302 can be
formed on the substrate 300. After that, subsequent processes
described in previous embodiment of the present general inventive
concept can be performed to form an ink supply hole and remove the
sacrificial mold layer 304.
[0044] 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.
[0045] 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.
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