KR100560532B1 - Field emission display device and manufacturing method of the same - Google Patents

Abstract

A field emission display device and a manufacturing method for improving light emission uniformity and brightness, the field emission display device comprising: first and second substrates, cathode electrodes formed in a stripe pattern on one surface of the first substrate, and facing the first substrate; On one surface of the second substrate, an anode electrode formed in a stripe pattern perpendicular to the cathode electrode and a plurality of electrodes are arranged independently in the pixel region of the cathode electrode crossing the anode electrode, and each tip portion is formed, thereby forming an electric field. And an emitter emitting electrons and a fluorescent film formed on the anode and receiving electrons to emit light. The emitter is formed by screen printing, and with the pointed ends of the particles partially exposed to the emitter surface upon application of voltage, electrons are emitted while the electric field is uniformly concentrated at the tip formed on each emitter. As a result, the light emitting uniformity and luminance of the screen can be improved while the emitter is formed by a thick film process that is simple in manufacturing and is advantageous for manufacturing a large display device.

Field emission, FD, field emission, emitter, cathode electrode, anode electrode, screen printing

Description

Field emission display device and manufacturing method thereof {Field emission display device and manufacturing method of the same}

1 is a cross-sectional view of a field emission display device according to the present invention.

2 is a partially enlarged view of a cathode electrode.

3 is a process chart showing a method of manufacturing a field emission display device according to the present invention.

4 is a schematic diagram showing a cathode electrode forming step;

5 to 7 are schematic diagrams showing the step of forming the emitter extruded portion.

8 is a schematic diagram showing an emitter paste printing step.

9 is a schematic diagram illustrating an anode electrode forming step.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display device. More particularly, the present invention relates to a field emission display device, and more specifically, emitters are formed per unit pixel while the emitters are manufactured in a thick film process. The present invention relates to a field emission display device and a method of manufacturing the same.

In general, a field emission display (FED) forms a strong electric field on an emitter to emit electrons, and the emitted electrons move at a vacuum speed to impinge on the fluorescent film formed on the anode electrode and emit a fluorescent film. It is a display element for implementing the image of.

Here, the emitter is an electron emission source of the field emission display device, and is formed in a spindt type or a plane type according to the structure of the display device. The spin type emitter is a triode tube mainly having a pointed cone shape. It is formed in a structure and is usually manufactured by a thin film process in which electron-emitting materials such as silicon or molybdenum are laminated on a cathode electrode.

These spin type emitters form tens or hundreds of emitter arrays per unit pixel, and emit electrons by concentrating an electric field at each emitter tip when voltage is applied. This has the advantage of excellent brightness and uniformity of the screen, but the manufacturing process is complicated to increase the manufacturing cost of the display device, there is a disadvantage in the manufacturing of a large display device.

On the other hand, the surface-type emitter is mainly formed in a bipolar structure, formed over the entire pixel region on the cathode electrode intersecting the anode electrode, and formed of a material having a relatively low work function compared to silicon or other metals, so that the physical pointed tip Even without the formation of electrons, electrons are emitted from the entire emitter surface when voltage is applied.

These surface type emitters are mainly composed of graphite, diamond like carbon (DLC), carbon nanotubes, carbon fibers, and the like, and are manufactured by thin film processes such as chemical vapor deposition or laser ablation, or screens. It is manufactured by a thick film process such as printing. Among them, the thick film process is simpler than the thin film process, so that the display device can be manufactured at a lower cost and has an advantage in manufacturing a large display device.

However, in the surface type emitter manufactured by the thick film process, most of the particles constituting the emitter are irregularly disposed so that the sharp ends of the particles are partially exposed to vacuum, and when the voltage is applied, the electric field is exposed to the vacuum. The electron emission takes place inside the emitter within a pixel, as it is mainly concentrated at the pointed end of the field, where electron emission takes place.

This non-uniform emission of electrons acts as a cause of lowering the uniformity and luminance of light emission not only in one pixel but also throughout the screen.

Therefore, the present invention is designed to solve the above problems, the object of the present invention is to produce an emitter by a thick film process, which is relatively easy to manufacture, while being present independently per unit pixel and forming an emitter having each tip portion The present invention provides a field emission display device and a method of manufacturing the same, which improve screen luminance and light emission uniformity.

In order to achieve the above object, the present invention,

The first and second substrates,

A cathode electrode formed on one surface of the first substrate in a stripe pattern;

An anode formed on one surface of the second substrate facing the first substrate in a stripe pattern perpendicular to the cathode electrode;

An emitter configured to independently form a plurality of front ends and to emit electrons by forming an electric field while a plurality of electrodes are independently disposed in a pixel region of the cathode electrode crossing the anode electrode;

A field emission display device is formed on the anode and includes a fluorescent film that receives electrons and emits light.

In addition, the present invention to achieve the above object,

Forming a cathode on the first substrate;

Forming a plurality of emitter extrusions in the screen mesh,

Mounting the screen mesh on a first substrate;

Applying an emitter paste onto the screen mesh and pressing with a squeeze to independently release a certain amount of emitter paste into the pixel region above the cathode electrode through each emitter extrusion;

Drying and firing the released emitter paste to remove organic matter inside the emitter paste,

Forming an anode and a fluorescent film on the second substrate;

It provides a method for manufacturing a field emission display device comprising the step of integrally sealing the first and second substrate.

The screen mesh forms an emitter extruded portion such that at least one emitter extruded portion is disposed in a pixel region of the cathode electrode, and one surface on which the emitter extruded portion is formed faces the first substrate, and the emitter extruded portion is formed of a screen. The further away from the surface of the mesh, the larger the diameter is formed.

As a result, a plurality of emitters are independently formed in the pixel region of the cathode electrode, and each emitter has a tip portion protruding to a predetermined height in the center according to the shape of the emitter extruded portion formed on the screen mesh.

Therefore, when voltage is applied, not only the electric field is concentrated at the sharp ends of the particles partially exposed to the emitter surface, but also electrons are emitted, and the electrons are uniformly concentrated at the tip of each emitter, thereby emitting electrons. It has the advantage of improving the uniformity of light emission throughout the pixel and the screen, and the brightness of the screen due to the increased amount of electron emission.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a field emission display device according to an exemplary embodiment of the present invention, wherein the field emission display device includes first and second substrates 10 and 20 disposed to face each other at regular intervals, and stripes on one surface of the first substrate 10. A cathode electrode 12 formed in a pattern, an anode electrode 22 formed in a stripe pattern perpendicular to the cathode electrode 12 on one surface of the second substrate 20 facing the cathode electrode 12, and the cathode And a plurality of emitters 14 disposed on the electrode 12 and a fluorescent film 24 formed on the surface of the anode electrode 22.

As the cross region of the cathode electrode 12 and the anode electrode 22 constitutes one pixel, when the pulse signal voltage required for driving each pixel is applied to the cathode electrode 12 and the anode electrode 22, A strong electric field formed between the cathode electrode 12 and the anode electrode 22 emits electrons (shown in dashed lines) at the emitter 14 in the pixel region, and the emitted electrons collide with the fluorescent film 24 It emits light.

The emitter 14 is made of a material having a low work function, for example graphite, diamond-like carbon, carbon nanotubes, carbon fibers, etc., so as to easily emit electrons even at a low electric field, and is manufactured by a thick film process. .

In the field emission display device according to the present exemplary embodiment, a plurality of emitters 14 are independently disposed in a unit pixel area on the cathode electrode 12, and each emitter 14 has a predetermined height at its center. It has a protruding tip.

As shown in FIG. 2, the emitter 14 is formed in a shape having a square bottom surface and a tip portion having a predetermined height, and the emitters 14 are separated from each other at regular intervals. Exists as.

As a result, when a predetermined voltage is applied to the cathode electrode 12 and the anode electrode 22 during the operation of the field emission display device, the electric field is uniformly concentrated at the tip end formed in each emitter 14 and the entire unit pixel. Uniform electron emission is achieved. At the same time, of course, the electrons are emitted from the ends of the particles constituting the emitter 14 partially exposed to the vacuum.

Therefore, in the field emission display device according to the present embodiment, the plurality of emitters 14 are independently disposed in the pixel region, and each emitter 14 forms a tip portion having a predetermined height, thereby emitting electrons in the unit pixel. By uniformly improving the uniformity of light emission and increasing the amount of electron emission effectively improves the brightness of the screen.

Next, a method of manufacturing the field emission display device according to the present invention will be described.

3 is a process flowchart sequentially illustrating a method of manufacturing a field emission display device according to the present invention.

In order to fabricate the field emission display device, first, as shown in FIG. 4, indium tin oxide (ITO) or silver is sputtered on the first substrate 10 and partially etched, or ITO or silver paste is screen printed. The stripe pattern cathode electrode 12 is formed. The barrier rib paste is screen printed and heat-treated between the cathode electrodes 12 to form the lower barrier rib 16.

Next, the screen mesh is plated in a specific pattern to form the emitter 14. The screen mesh is a known one in which extremely thin wires such as stainless steel, polyester, or nylon are organized in a fine lattice shape, and the screen mesh is formed by using a photolithography process.

The process of making the screen mesh will be described in more detail with reference to FIGS. 5 to 7 as follows. First, a conventional screen mesh 30 is prepared, and a positive type platemaking emulsion, that is, a photoresist solution is applied to one surface of the screen mesh 30, and then dried to cure the first photoresist film 32.

Then, an exposure mask 34 having a plurality of holes 34a formed on the screen mesh 30 is mounted, and an exposure lamp (not shown) is operated to perform exposure for a predetermined time. A portion of the first photoresist film 32 irradiated with light (shown by an arrow) through the hole 34a formed in the exposure mask 34 by the exposure operation is increased in solubility by a chemical reaction.

As a result, when the exposure mask 34 is removed and the first photoresist film 32 is developed, the portion of which the solubility is increased is removed while the first photoresist film 32 has a plurality of first emitters as shown in FIG. 6. The extrusion hole 32a is formed.

As shown in FIG. 7, the second photoresist film 36 is formed on the surface of the first photoresist film 32, and partially exposed and developed to form the second photoresist film 36 on the first emitter extrusion hole 32a. The second emitter extrusion hole 36a having a diameter larger than the one emitter extrusion hole 32a is formed.

Since the thickness of the photoresist film formed by the application of one plate making emulsion is approximately 1 to 2 µm, the above-described process, that is, the photo, is performed until the thickness of the entire photoresist film formed on the screen mesh 30 is approximately 10 µm. The formation of the resist film, the partial exposure and the development process are repeated at least five times.

At this time, the diameter of the emitter extrusion hole formed in each photoresist film is gradually formed larger than the diameter of the emitter extrusion hole formed first, and as shown in FIG. 8, the multilayer formed on the final screen mesh 30. The photoresist film 38 forms an emitter extruded portion 38a having a gradually larger diameter as it moves away from the surface of the screen mesh 30.

As such, the screen mesh 30 is plated to form a plurality of emitter extruded portions 38a, and at least one or more, more preferably, a plurality of emitter extruded portions 38a are disposed in a unit pixel area. The film 38 is patterned.

Next, the patterned screen mesh 30 is mounted on the first substrate 10 at regular intervals. In particular, the screen mesh 30 smoothly moves the squeeze 40, and the multilayer photoresist film 38 is formed so that each emitter can be formed in the shape of the emitter extruded portion 38a. One surface is disposed to face the first substrate 10.

Then, the emitter paste 42 is applied onto the screen mesh 30, and the squeeze 40 is moved from one end of the screen mesh 30 to the opposite side of the screen mesh 30 to compress the emitter paste 42, thereby compressing the respective emitters. The emitter paste 42 is extruded onto the cathode electrode 12 through the rotor extrusion section 38a.

The emitter paste 42 printed on the cathode electrode 12 as described above forms a leading end portion having a predetermined height at the center portion according to the shape of the emitter extrusion portion 38a. Are independently arranged in the unit pixel region without overlapping with the adjacent emitter paste.

This can be easily realized by adjusting the viscosity of the emitter paste 42 after printing of the emitter paste 42 such that the shape is not disturbed and does not overlap with the adjacent emitter paste while maintaining the tip shape.

As described above, the emitter paste 42 is printed on the cathode electrode 12, and then the organic material inside the emitter paste 42 is removed through a drying and firing process.

For example, the emitter paste 42 includes graphite as a main component, and an additive such as a solvent and a binder is mixed to have a viscosity suitable for printing. The emitter paste 42 is formed by a drying and baking process performed after a printing process. The organic material inside is removed to complete the final emitter 14.

As described above, a plurality of emitters 14 are independently disposed in the unit pixel area, and each emitter 14 forms a tip portion having a constant height. The manufacturing of the emitter 14 is to adjust the pattern shape of the screen mesh 30 to easily adjust the shape and size of the emitter 14, the arrangement interval and the number of emitter 14 in the unit pixel. .

Subsequently, as shown in FIG. 9, a stripe pattern anode electrode 22 is formed on the transparent second substrate 20 in the same manufacturing process as the cathode electrode 12 described above, and the phosphor paste is formed on the anode electrode 22. After the coating, the fluorescent film 24 is formed by heat treatment, and a well-known partition paste is printed between the anode electrodes 22 and then heat-treated to form the upper partition wall 26.

Finally, the first substrate 10 and the second substrate 20 are integrally sealed through a known sealing process, the inside of the display element is evacuated to high vacuum, and then the display element is sealed to seal the display element. The same field emission display device is completed.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, according to the present invention, a plurality of emitters are independently disposed in the pixel area, and as each emitter forms a tip portion having a predetermined height, the electron emission in the unit pixel is uniformed and the amount of electron emission is increased to increase the uniformity of emission of the screen. The brightness can be effectively improved.

In addition, the emitter is manufactured by a thick film process, thereby lowering the manufacturing cost of the display device and having a more advantageous advantage in manufacturing a large display device.

Claims (6)

First and second substrates; A cathode electrode formed on one surface of the first substrate in a stripe pattern; An anode formed on a surface of the second substrate facing the first substrate in a stripe pattern perpendicular to the cathode electrode; An emitter configured to independently form a plurality of front ends of the plurality of electrodes independently disposed in the pixel region of the cathode electrode crossing the anode electrode and to emit electrons by forming an electric field; And a fluorescent film formed on the anode and configured to receive electrons and emit light. Forming a cathode on the first substrate; Forming a plurality of emitter extrusions in the screen mesh; Mounting the screen mesh on a first substrate; Applying an emitter paste onto the screen mesh and pressing with a squeeze to independently release a certain amount of emitter paste into the pixel region above the cathode electrode through each emitter extrusion; Drying and firing the released emitter paste to remove organic material within the emitter paste; Forming an anode electrode and a fluorescent film on a second substrate; And integrally sealing the first and second substrates. The method of claim 2, Forming an emitter extrusion in the screen mesh, Applying and drying a platemaking emulsion on the screen mesh to form a first photoresist film, and partially exposing and developing the first emitter extrusion hole; Forming a second photoresist film on the surface of the first photoresist film, partially exposing and developing to form a second emitter extrusion hole having a diameter larger than that of the first emitter extrusion hole on the first emitter extrusion hole; A method of manufacturing a field emission display device comprising the step. The method of claim 3, wherein Forming an emitter extrusion in the screen mesh, The photoresist film is repeatedly formed at least five times, and an emitter extrusion hole is formed in each photoresist film, and the emitter extrusion hole is formed to have a gradually larger diameter than the previously formed emitter extrusion hole. A method of manufacturing a field emission display device. The method of claim 2, Forming an emitter extrusion in the screen mesh, A method of manufacturing a field emission display device comprising forming at least one emitter extruded portion within a pixel region of a cathode electrode. The method of claim 2, Mounting the screen mesh on the first substrate, A method of manufacturing a field emission display device comprising mounting a screen mesh so that one surface of the emitter extruded portion faces the first substrate.

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