KR20060115101A - A method for producing an electron emission source, an electron emission source and an electron emission element having the electron emission source - Google Patents

Abstract

The present invention provides a method of forming a UV blocker-containing photoresist pattern defining an electron emission source formation region using a composition for forming a photoresist pattern including a UV blocker on a substrate, and defining the electron emission formation region. Applying, exposing, and developing the composition for forming an electron emission source on the substrate on which the UV-blocking agent-containing photoresist pattern is formed; and firing the electron emission composition on the electron emission source formation region. The present invention relates to a method for producing an electron emission source, and an electron emission element provided with the electron emission source. By using the electron emission source manufactured according to the method of manufacturing the electron emission source, an electron emission device having improved reliability can be obtained.

Description

A method for preparing an electron emission source, an electron emission source and an electron emission device comprising the electron emission source}

1A and 1B are diagrams schematically showing an exposure process and a development result of a conventional composition for forming an electron emission source,

2A is a schematic representation of a UV blocker-containing photoresist pattern in accordance with the present invention;

2B and 2C are schematic views illustrating an exposure process and a development result of the composition for forming an electron emission source according to the present invention, respectively.

3 is a view schematically showing an embodiment of an electron emitting device according to the present invention.

<Short description of drawing symbols>

10, 20: substrate 12, 22: photoresist pattern

17, 27: electron emission source formation region 19: overexposure residue

110: lower substrate 120: cathode electrode

130: insulator layer 140: gate electrode

160: electron emission source 170: phosphor layer

180: anode electrode 190: upper substrate

The present invention relates to an electron emission source manufacturing method, an electron emission source and an electron emission device, and more particularly, an electron emission source manufacturing method using a UV blocker-containing photoresist pattern, an electron emission source produced using the method and It relates to an electron emission device having the electron emission source.

An electron emission device emits electrons from an electron emission source of a cathode electrode by applying a voltage between the anode electrode and the cathode electrode to form an electric field, and impinges the electrons on a fluorescent material on the anode electrode side to emit light. It is an element to make.

Carbon-based materials including carbon nanotubes (CNTs), which have excellent electronic conductivity, have excellent conductivity and electric field concentration effects, low work function, and excellent field emission characteristics, so that low-voltage driving is easy and large area is possible. It is expected as an ideal electron emission source of an electron emission element.

The method for producing an electron emission source containing carbon nanotubes includes, for example, a carbon nanotube growth method using a CVD method or the like, a paste method using an electron emission source formation composition containing carbon nanotubes and a vehicle. By using the paste method, the manufacturing cost is low and an electron emission source can be formed in a large area. Compositions for forming electron emission sources, including carbon nanotubes, are described, for example, in US Pat. No. 6,436,221.

The step of applying an electron emission source to a predetermined electron emission source forming region in the electron emission source manufacturing method using the paste method may be divided into a case of using a separate photoresist pattern and a case of not using a photoresist pattern. For example, when the composition for forming an electron emission source includes a photosensitive resin and a photoinitiator, electron emission patterning is possible without a separate photoresist pattern.

Meanwhile, FIGS. 1A and 1B schematically illustrate a process and a development result of exposing an electron emission source to a predetermined electron emission source forming region using a conventional photoresist pattern, respectively.

According to FIG. 1A, a photoresist pattern 12 is formed on the substrate 10. The photoresist pattern 12 defines an electron emission source formation region 17. The photoresist pattern 12 is formed on the substrate 10, and then the composition for forming the electron emission source 14 is applied to cover the photoresist pattern 12 and the electron emission source formation region 17. Thereafter, the composition 14 for forming an electron emission source is exposed by the exposure light beam 16. The exposure beam 16 can be UV, for example.

FIG. 1B illustrates a result of development after performing an exposure process as shown in FIG. 1A. Referring to FIG. 1B, an electron emission source 18 exists as desired in the electron emission source forming region 17 defined by the photoresist pattern 12, but the original value is formed on the photoresist pattern 12. It can be seen that overexposure residues 19 remain. The overexposed part residue 19 is a residue remaining after the composition 14 for forming an electron emission source is exposed by the exposure light partially transmitted through the photoresist pattern 12 during the exposure process as shown in FIG. 1A. This may occur because the photoresist pattern 12 does not completely block the exposure light beam 16. The over-exposure residue 19 may remain in the electron-emitting device even after development, thereby reducing the reliability of the electron-emitting device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, an electron emission source manufacturing method for preventing the over-exposure residues from occurring in regions other than the electron emission source formation region, an electron emission source manufactured using the method and the An object of the present invention is to provide an electron emitting device having an electron emission source.

In order to achieve the above object of the present invention, a first aspect of the present invention, by using a composition for forming a photoresist pattern including a UV blocker on a substrate, using a UV blocker-containing photoresist pattern defining an electron emission source formation region Forming, applying, exposing and developing an electron emission source forming composition on the substrate on which the UV blocking agent-containing photoresist pattern defining the electron emission source forming region is formed; It provides a method for producing an electron emission source comprising the step of firing a composition for forming an electron emission source.

In order to achieve the another object of the present invention, a second aspect of the present invention provides an electron emission source manufactured using the method for producing an electron emission source.

In order to achieve another object of the present invention, a third aspect of the present invention provides an electron emission device provided with the electron emission source.

According to the electron emission source manufacturing method according to the present invention, it is possible to pattern the electron emission source with high precision without the over-exposed part residue, it is possible to obtain an electron emission device with improved reliability using this.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

According to the electron emission source manufacturing method according to the present invention, first, a UV blocking agent-containing photoresist pattern defining an electron emission source forming region is formed on the substrate. At this time, a composition for forming a UV blocker-containing photoresist pattern is used. By using the UV blocker-containing photoresist pattern, it is possible to prevent the formation of the overexposed part of the composition for forming an electron emission source in the electron emission source non-forming region.

FIG. 2A is provided with a UV blocker-containing photoresist pattern 22 defining an electron emission source forming region 27 over the substrate 20.

The substrate 20 is a substrate on which an electron emission source is to be formed, and may be different according to the electron emission element to be formed, which is easily recognized by those skilled in the art. For example, the "substrate" may be a cathode electrode when manufacturing an electron emission device having a gate electrode provided between a cathode electrode and an anode electrode, and a gate electrode disposed below the cathode electrode. When manufacturing an electron emission device, it may be an insulating layer which insulates the cathode electrode and the gate electrode.

The UV blocker-containing photoresist pattern 22 defines the electron emission source forming region 27, and because it includes a UV blocker, it is a region other than the electron emission forming region 27, that is, the electron emission non-forming region. Prevent UV transmission. This prevents overexposure residues 19 on the photoresist pattern 12 as shown in FIG. 1B.

The UV blocking agent-containing photoresist pattern 22 may be formed according to a conventional photoresist pattern forming method using a composition for forming a photoresist pattern including a UV blocking agent. More specifically, the photoresist pattern forming composition including the UV blocking agent may be applied, exposed, and developed on the substrate 20 of FIG. 2A to form the photoresist pattern 22.

The UV blocking agent may be selected from materials capable of effectively preventing UV transmission. More specifically, the UV blocking agent is TiO ₂ , ZnO and In ₂ O ₃ ; And oxides of V, Cr, Mn, Fe, Co, Ni, Cu and the above metals. Or from the group consisting of graphite and carbon black.

The content of the UV blocking agent may be 0.1 parts by weight to 50 parts by weight, preferably 1 part by weight to 15 parts by weight, per 100 parts by weight of the composition for forming a photoresist pattern. When the content of the UV blocker is less than 0.1 part by weight per 100 parts by weight of the composition for forming a photoresist pattern, the content of the UV blocker contained in the photoresist pattern is insignificant, and a satisfactory UV blocking effect cannot be obtained, and the content of the UV blocker This is because if the amount of the photoresist pattern forming composition exceeds 50 parts by weight, the precision of the photoresist pattern may be lowered and the viscosity may be increased, which may be disadvantageous in coating the composition for forming the photoresist pattern.

The photoresist pattern forming composition is not particularly limited as long as it can be used with the UV blocking agent according to the present invention. The photoresist pattern forming composition may be directly prepared and used, and a UV blocking agent may be added to a commercially available photoresist pattern forming composition.

Conventional photoresist pattern-forming compositions may include photosensitive resins, photoinitiators and solvents. The photoinitiator serves to initiate crosslinking of the photosensitive resin in response to exposure, and the solvent serves to impart a predetermined flowability and viscosity to the composition for forming a photoresist pattern.

The photosensitive resin includes, for example, novolak resin, but is not limited thereto. The photoinitiator may include, for example, a diazide photosensitive compound, but is not limited thereto. The solvent may include, but is not limited to, for example, propylene glycol methyl ether acetate (PGMEA), methyl methoxy propionate (MMP), and the like.

A detailed description of the composition for forming a photoresist pattern is described in Korean Patent Publication Nos. 2005-0022494, 2004-0077277, 2004-0066541, 2003-0060022, and the like. May be incorporated herein.

The method of forming the UV blocker-containing photoresist pattern 22 using the composition for forming a photoresist pattern including the UV blocker as described above may be a conventional photoresist forming method, that is, a photoresist including an application, exposure and development step. The formation method can be used. According to one embodiment of the method for forming the UV blocker-containing photoresist pattern 22, first, a composition for forming a photoresist pattern including a UV blocker is applied to the substrate 20. As the coating method, various methods such as a roll coating method and a spin coating method can be used. Thereafter, selective exposure is performed in consideration of the photoresist pattern to be formed. The exposure time and the light source may differ depending on the composition for forming a photoresist pattern used. Thereafter, the exposed photoresist pattern-forming composition is developed using a suitable developer to complete the UV blocker-containing photoresist pattern.

As described above, the photoresist pattern is formed on the substrate, and then the composition for forming an electron emission source is applied, followed by performing an exposure process as shown in FIG. 2B and then developing it, as shown in FIG. 2C. Likewise, an electron emission source is applied to the electron emission source forming region.

According to FIG. 2B, a photoresist pattern 22 defining an electron emission source formation region 27 is formed on the substrate 20, and covers the electron emission source formation region 27 and the photoresist pattern 22. The composition 24 for forming an electron emission source is applied.

The composition for forming an electron emission source includes a carbonaceous material and a vehicle. As the carbon-based material, for example, various materials such as carbon nanotubes, fullerenes, and silicon carbide may be used. On the other hand, the vehicle included in the composition for electron emission source formation serves to adjust the printability and viscosity of the composition for electron emission source formation. The vehicle may consist of a resin component and a solvent component.

The resin component may be, for example, a cellulose resin such as ethyl cellulose, nitro cellulose or the like; Acrylic resins such as polyester acrylate, epoxy acrylate, urethane acrylate and the like; At least one of a vinyl-based resin such as polyvinyl acetate, polyvinyl butyral, polyvinyl ether, and the like may be included, but is not limited thereto.

The solvent component is, for example, at least one of terpineol, butyl carbitol (BC), butyl carbitol acetate (BCA), toluene and texanol It may include. Among these, it is preferable to contain terpineol.

The content of the resin component may be 100 to 500 parts by weight, more preferably 200 to 300 parts by weight based on 100 parts by weight of the carbon-based material. On the other hand, the content of the solvent component may be 500 to 1500 parts by weight, preferably 800 to 1200 parts by weight based on 100 parts by weight of the carbon-based material. When the content of the vehicle consisting of the resin component and the solvent component is outside the above range may cause a problem that the printability and flowability of the composition for forming an electron emission source is lowered. In particular, when the content of the vehicle exceeds the above range, there is a problem that the drying time may be too long.

In addition, the composition for forming an electron emission source of the present invention may further include an adhesive component, a filler, and the like as necessary.

The adhesive component serves to attach the electron emission source to the substrate, and may be, for example, an inorganic binder. Non-limiting examples of such inorganic binders include frit, silane, water glass, and the like, and two or more of these may be mixed and used. The frit may be made of, for example, lead oxide-zinc oxide-boron oxide (PbO-ZnO-B ₂ O ₃ ). Among the inorganic binders, frit is preferable.

The content of the inorganic binder in the composition for forming an electron emission source may be 10 to 50 parts by weight, preferably 15 to 35 parts by weight based on 100 parts by weight of the carbon-based material. When the content of the inorganic binder is less than 10 parts by weight based on 100 parts by weight of the carbon-based material, satisfactory adhesive strength cannot be obtained, and when the content of the inorganic binder exceeds 50 parts by weight, printability may be deteriorated.

The filler is a material that serves to improve the conductivity of the carbon-based material that is not sufficiently adhered to the substrate, non-limiting examples thereof include Ag, Al, Pd.

The composition for forming an electron emission source of the present invention comprising a material as described above may have a viscosity of 3,000 to 50,000 cps, preferably 5,000 to 30,000 cps. If it is out of the viscosity range, a problem may arise that the workability is poor.

Thereafter, the composition 24 for forming an electron emission source is selectively exposed using the exposure light beam 26 as shown in FIG. 2B. The exposure ray 26 may be UV, for example.

At this time, by the UV blocking agent-containing photoresist pattern 22 according to the present invention, UV does not reach the composition for forming an electron emission source applied to the upper region of the photoresist pattern 22. Thus, as shown in FIG. 1B, the overexposed residue 19 is not formed on the photoresist pattern 12. Therefore, when the developing process is performed after the exposure process, not only the over-exposed part residues remain as shown in FIG. 2C, but also the UV blocking agent-containing photoresist pattern 22 is easily removed, so that The electron emission source remains accurate.

Thereafter, as shown in FIG. 2C, the electron emission source 28 printed on the substrate 20 undergoes a firing step. Through the firing step, the carbon-based material in the composition for forming an electron emission source may improve adhesion to the substrate, at least some vehicles may be volatilized, and other inorganic binders may be melted and solidified, thereby contributing to improvement in durability of the electron emission source. Will be. The firing temperature should be determined in consideration of the volatilization temperature and time of the vehicle included in the composition for electron emission source formation. Typical firing temperatures are 400 to 500 ° C, preferably 450 ° C. If the firing temperature is less than 400 ℃ may cause a problem that the volatilization such as a vehicle is not sufficiently made, if the firing temperature exceeds 500 ℃ may cause a problem that the manufacturing cost rises, the substrate may be damaged.

The firing step can be carried out in the presence of an inert gas. The inert gas may be, for example, nitrogen gas, argon gas, neon gas, xenon gas, and a mixed gas of two or more thereof. This is to minimize the deterioration of the carbon-based material during the predetermined step.

The carbon-based material on the surface of the fired product thus fired is optionally subjected to an activation step. According to one embodiment of the activation step, after applying a solution that can be cured in the form of a film through a heat treatment process, for example, an electron emission source surface treatment agent containing a polyimide-based polymer on the firing result, and then heat treatment Then, the film formed by the heat treatment is peeled off. According to another embodiment of the activation step, the activation process may be performed by forming an adhesive part having an adhesive force on the surface of the roller driven by a predetermined driving source and pressing the surface of the firing product at a predetermined pressure. Through this activation step, the carbon-based material may be controlled to be exposed or vertically aligned to the electron emission surface.

The electron emission source according to the present invention formed as described above is formed by using a UV blocker-containing photoresist pattern capable of effectively blocking UV, and thus no over-exposure residues remain in the electron emission source non-forming region, and a precise pattern Can have

The electron emission source as described above can be applied to the electron emission device. The electron emission device according to the present invention is formed so as to be electrically connected to a first substrate and a second substrate disposed opposite to each other, a cathode electrode formed on the first substrate, and a cathode electrode formed on the substrate, An electron emission source including a material, an anode electrode formed on the second substrate, and a fluorescent layer emitting light by electrons emitted from the electron emission source. The electron emission source is prepared by the method as described above.

3 is a cross-sectional view of an embodiment of such an electron emitting device. 3 schematically illustrates an electron emitting device having a triode structure among various electron emitting devices according to the present invention. The electron emission device 200 illustrated in FIG. 3 includes an upper plate 201 and a lower plate 202, and the upper plate is an upper electrode 190 and an anode electrode 180 disposed on the lower surface 190a of the upper substrate. And a phosphor layer 170 disposed on the bottom surface 180a of the anode electrode.

The lower plate 202 has a lower surface substrate 110 disposed in parallel with the upper substrate 190 at predetermined intervals to have an inner space, and a cathode electrode disposed in a stripe shape on the lower substrate 110 ( 120, a gate electrode 140 arranged in a stripe shape to intersect the cathode electrode 120, an insulator layer 130 disposed between the gate electrode 140 and the cathode electrode 120, and the insulator layer ( 130 and an electron emission source hole 169 formed in a portion of the gate electrode 140 and the electron emission source hole 169 are disposed in the electricity supply to the cathode electrode 120 and lower than the gate electrode 140. And an electron emission source 160 disposed therein. Detailed description of the electron emission source 160 is the same as described above, and thus will be omitted.

The upper plate 201 and the lower plate 202 are maintained in a vacuum at a pressure lower than atmospheric pressure, and the spacer 192 supports the pressure between the upper plate and the lower plate generated by the vacuum and partitions the light emitting space 210. It is disposed between the upper plate and the lower plate.

The anode electrode 180 applies a high voltage required for acceleration of electrons emitted from the electron emission source 160 to allow the electrons to collide with the phosphor layer 170 at high speed. The phosphor of the phosphor layer is excited by the electrons and emits visible light while falling from a high energy level to a low energy level.

The gate electrode 140 serves to facilitate the emission of electrons from the electron emission source 160, and the insulator layer 130 partitions the electron emission source hole 169 and the electrons. It serves to insulate the emission source 160 and the gate electrode 140.

The electron-emitting device of the present invention has been described with an electron-emitting device having a triode structure as shown in FIG. 3 as an example, but the present invention includes not only the triode structure, but also an electron emitting device having another structure including a dipole tube. In addition, it is possible to prevent damage to the electron emission element in which the gate electrode is disposed below the cathode electrode, the gate electrode and / or the cathode electrode due to the arc that is assumed to be caused by the discharge phenomenon, and to focus the electrons emitted from the electron emission source. It can also be used for electron emitting devices with grids / meshes to ensure the safety. On the other hand, it is also possible to apply the structure of the electron emitting device as a display device or a backlight unit.

Hereinafter, preferred examples and comparative examples of the present invention are described. The following examples are only described for the purpose of more clearly expressing the present invention, and the content of the present invention is not limited to the following examples.

Example

A photoresist pattern forming composition (trade name is AZ series, manufactured by Clariant) was prepared, and 5 g of Cr ₂ O ₃ was added as a UV blocking agent, and then on a substrate having a Cr gate electrode, an insulating film, and an ITO electrode. It was applied at 3 μm. Thereafter, exposure was performed using a mask capable of defining an electron emission source formation region, followed by development using a TMAH solution as a developer for the photoresist pattern forming composition, having a thickness of 3 μm and a height of 3 μm. And a photoresist pattern having an interval of 30 μm was formed.

Subsequently, 1 g of CNT powder (manufactured by ILJIN), 0.2 g of frit (8000 L, manufactured by Emerging Industries), 5 g of polyester acrylate, and 5 g of benzophenone were added to 10 g of terpineol, followed by stirring to have a viscosity of 30,000 cps. A composition for forming an electron emission source was prepared. The composition for forming an electron emission source was applied to the photoresist pattern and the electron emission source forming region, and then irradiated with a parallel exposure machine at an exposure energy of 2000 mJ / cm ² . Thereafter, the film was developed using acetone, and the composition for electron emission source formation was printed on the electron emission source formation region defined by the photoresist pattern. Thereafter, the mixture was calcined in the presence of a temperature of 450 ° C. and nitrogen gas to form an electron emission source. Subsequently, a substrate using ITO as a fluorescent film and an anode electrode was disposed so as to be oriented with the substrate on which the electron emission source was formed, and a spacer was formed between the substrates to maintain the cell gap between the substrates. The electron emitting device is referred to as sample 1.

Comparative example

An electron-emitting device was formed in the same manner as in the above example, except that a novolak-type photoresist composition without adding Cr ₂ O ₃ , a UV blocking agent, was used. This is called sample A.

As a result of observing the electron emission sources of Samples 1 and A with an optical microscope, it was found that in the case of Sample A, there was an overexposed residue, whereas in Sample 1, there was no overexposed residue. Sample 1 showed better performance in current density, lifetime, and the like than Sample A.

When the electron emission source is manufactured according to the electron emission source manufacturing method of the present invention, an effect can be obtained since no residues of the overexposed portion remain in the electron emission source non-forming region.

First, an arc phenomenon may be prevented when the electron emission device is driven.

Secondly, abnormal light emission due to hot-spots on the metal electrodes can be prevented.

Third, the short phenomenon with the gate electrode can be prevented.

Claims (6)

Forming a UV blocker-containing photoresist pattern defining an electron emission source forming region using a composition for forming a photoresist pattern including a UV blocker on a substrate; Coating, exposing and developing the composition for forming an electron emission source on the substrate on which the UV blocking agent-containing photoresist pattern defining the electron emission source formation region is formed; And Firing the composition for forming an electron emission source on the electron emission source formation region; Method of producing an electron emission source comprising a. The method of claim 1, wherein the UV blocking agent is selected from TiO ₂ , ZnO and In ₂ O ₃ ; And V, Cr, Mn, Fe, Co, Ni, Cu, and oxides of the metals. The method of claim 1, wherein the UV blocking agent is selected from the group consisting of graphite and carbon black. The method of claim 1, wherein the content of the UV blocking agent is 0.1 to 50 parts by weight per 100 parts by weight of the composition for forming the photoresist pattern. An electron emission source prepared according to any one of claims 1 to 4. A first substrate and a second substrate disposed to face each other; A cathode electrode formed on the first substrate; An electron emission source formed to be electrically connected to a cathode electrode formed on the substrate; An anode electrode formed on the second substrate; And A fluorescent layer emitting light by electrons emitted from the electron emission source; An electron emission device comprising: an electron emission source manufactured according to any one of claims 1 to 4;

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