KR20030073367A - Field Emission Device and method of the same - Google Patents

Abstract

PURPOSE: An electron emission device and a method for manufacturing the same are provided to reduce manufacturing procedures and cost by eliminating the necessity of performing a process for forming a focusing electrode. CONSTITUTION: An electron emission device for emitting electrons by the electric field applied to an electron lead-out electrode(204), comprises a lower electrode(202) having a slope with respect to a flat substrate; and an insulating layer(203) interposed between the electron lead-out electrode and the lower electrode, and which maintains a voltage difference between the electron lead-out electrode and the lower electrode.

Description

Electronic emission device and method of manufacturing the same {Field Emission Device and method of the same}

The present invention relates to a technique for improving focusing of electrons emitted from an electron-emitting device of a flat-panel display device. In particular, the present invention can be applied to a large-screen flat-panel display manufacturing technology by implementing an electron-emitting device that can be applied at a low cost and large area on a flat surface. The present invention relates to an electron emitting device by a screen printing method and a method of manufacturing the same.

The composition of the electron-emitting device plays the biggest role in realizing the FED, which has the high brightness, low power, fast response speed and wide viewing angle, which are the advantages of the CRT for display, and which makes it possible to make a large volume that has been a disadvantage in the CRT. do.

In the conventional electron-emitting device for flat panel display, the electron-emitting device could be formed only by repeating the deposition and etching process using expensive equipment to obtain the electron-generating structure, and withdrawing electrons from the electron-emitting device. In order to do so, a classic world was required.

In addition, the electrons emitted in the process of emitting electrons due to the voltage difference between the electron-emitting electrode and the electron-emitting device are not concentrated and are emitted to the surroundings. In order to solve this problem, a focusing electrode must be formed through an expensive process.

In order to perform such a large number of processes, high cost is required, and it is not suitable for mass production, and there are many disadvantages such as difficulty in large-area application.

With the development of information and communication technology and the advent of the multimedia era, the importance of display is being emphasized more than ever.

Accordingly, there is a demand for development of a lightweight, thin, low power consumption, low cost, and high quality flat panel display.

Flat panel displays currently under development or production include PDP, LCD, VFD, FED, OLED, and ELD.

However, in terms of price and picture quality, CRTs are still competitive with some flat panel displays.

However, the market share of CRT is decreasing.

Therefore, researches on display devices based on vacuum technology having excellent quality of CRT and light weight and thinness are being made, and some progress has been made.

However, the process involved for the construction of the electron-emitting device, which is essential for the manufacture of a flat panel display device based on such a vacuum technology, requires high cost and is difficult to apply to mass production due to difficulty in large-area application.

Therefore, the development of a low cost and high efficiency electron emitting device plays a very important role.

Recently, a tip [105-a] type electron emitting device and a carbon-based material shown in FIG. 5B are used to induce concentration of an electric field shown in FIG. 105-b] has been studied.

In order to form a tip type electron emitting device, there is a lower electrode 102 for applying a signal on the substrate 101, an insulating layer 103 is formed thereon, and the electron extracting electrode 104 is formed through a mask having a pattern. After forming the film, the sacrificial layer having an inclination to the electron-emitting electrode using an evaporation apparatus called an E-beam having excellent thin film formation characteristics in the vertical direction while applying rotation to a substrate having a predetermined sized hole by an etching process. And a process such as forming a conical electron-emitting device 105-a by depositing a metal such as molybdenum using an E-beam in the vertical direction toward the substrate, requires complicated and expensive equipment.

In addition, it is known that there is a problem in even electron emission, such as a decrease in emission current, when a tip for emitting electrons is not sharply formed when forming a conical electron emission device.

In order to solve such a complicated process of forming a tip-shaped cone, a method using a carbon-based material having a property of emitting electrons at a low electric field is used.

5B shows an electron-emitting device constructed using a carbon-based material as an electron emission source.

Although the overall structure is similar to the tip type, it can be seen that the electron-emitting device is constructed in a planar shape using a carbon-based device in a conical electron-emitting source requiring complex fixing.

When electrons are emitted from the electron emission source, the spreading of the electron beam emitted from the device occurs due to the applied voltage applied to the electron-emitting electrode due to the characteristics of the electron-emitting device, and thus a focusing electrode forming process is required to prevent the electron beam from spreading. Do.

The focusing electrode is of two types: a method of forming a focusing electrode in parallel with the electron-drawing electrode and a method of forming an insulating layer on the electron-drawing electrode again and forming a focusing electrode thereon in a direction perpendicular to the electron-drawing electrode. I use it.

6A to 6C show the shape of the electron beam emitted from the tip type electron emission device when a voltage is applied to the electron extraction electrode.

Fig. 6A shows electron emission characteristics from a tip type electron emission device in which no focusing electrode is formed.

Electrons emitted from the tip tip spread upward and spread widely.

Fig. 6B shows the emission characteristics of the electron beam when the planar focusing electrode is constructed and applied.

The electrons emitted at the tip of the tip by the electric field applied to the electron withdrawing electrode are spread by the focusing electrode 106 formed in parallel with the electron withdrawing electrode as compared with the emitted electron emission characteristic shown in FIG. 6A. You can see little.

However, even when the planar focusing electrode 106 is used, it is difficult to completely control the electrons emitted to the surroundings.

FIG. 7A shows the form of an electron beam emitted from the electron-emitting device by applying a voltage to the electron-emitting electrode when using a carbon-based material as the electron-emitting device.

7B is a view illustrating emission characteristics of the electron beam when the planar focusing electrode is configured and applied.

The electrons emitted from the carbon-based electron-emitting devices by the electric field applied to the electron-drawing electrodes are spread by the focusing electrode 106 formed in parallel with the electron-emitting electrodes to the emitted electron-emitting characteristics shown in FIG. 7A. It can be seen that it is relatively small.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a flat panel display electron-emitting device and a method of manufacturing the same.

Figure 1a is a view of the electron-emitting device formed using a carbon-based device as an electron emission source in accordance with the present invention, the conductive paste is formed for the purpose of performing the role of the lower electrode and the focusing electrode by the screen printing method

FIG. 1B is a cross-sectional view taken along the line AA ′ of the electron-emitting device shown in FIG. 1A

Fig. 2 is a schematic view of electron 1 emission of an electron-emitting device using a carbon-based material according to the present invention and a focusing electrode formed of a conductive paste by screen printing.

3A to 3F are process diagrams of an electron-emitting device having a focusing electrode by the printing method according to the present invention.

4 is an embodiment produced by applying the present invention

Figure 5a is a cross-sectional view of a conventional tip-type electron emitting device

Figure 5b is a cross-sectional view of the electron-emitting device using a conventional carbon series

6A is a schematic view of electron emission of a tip type light emitting device having a conventional electron extraction electrode;

6B is a schematic view of electron emission of a tip type electron emission device in which a conventional electron extraction electrode and a parallel focusing electrode exist.

6c is a schematic view of electron emission of a tip type electron emission device having a conventional electron extraction electrode and a vertical focusing electrode;

7A is a schematic view of electron emission of a device manufactured using a conventional carbon-based material as an electron-emitting device.

7B is an electron emission conceptual diagram when a focusing electrode is formed in parallel with an electron withdrawing electrode in a device manufactured using a conventional carbon-based material as an electron emission device;

* Explanation of symbols for the main parts of the drawings

101: substrate 102: lower electrode

103: insulating layer 104: lead-out electrode

105: electron-emitting device 106: focusing electrode

201: carbon-based electron emitting device 202: lower electrode

203: insulating layer 204: electron withdrawing electrode

205: lower electrode lead wire 206: electron withdrawing electrode lead wire

207: substrate

In order to achieve the above object, in the present invention, in the electron-emitting device of a flat-panel display device which emits electrons by applying an electric field applied to the electron-emitting electrode using a carbon-based device as an electron-emitting source, the lower electrode is a flat substrate. The electron-emitting device is formed between the lower electrodes, the insulating layer is formed on the upper surface corresponding to the lower electrode, and the electron-emitting electrode is formed on the upper surface corresponding to the insulating layer. It is characterized by.

In addition, the lower electrode may have a circular, rectangular, linear, or the like pattern, and may serve as a focusing electrode.

In addition, the electron-emitting device is a carbon-based material of at least one of carbon nanotubes (CNTs), diamond like carbon (DLC), Graphit nanofiber (GNF), Graphite, the electron-emitting device has a pattern of circular, square, linear and the like. It is characterized by having.

In addition, the present invention is a step of forming an electron-emitting device by applying a carbon paste on a substrate using a screen printing method, the step of forming a conductive paste having a predetermined viscosity on the substrate by a screen printing method; Forming a carbon-based material on the conductive paste formed on the substrate; Forming a carbon material protective layer; Forming an insulating layer over the protective layer; Forming an electron extracting electrode layer on the insulating layer by using a printing method or a general thin film deposition method; Characterized in that the finishing process to remove the protective layer covering the carbo material.

According to the present invention, the lower electrode is formed by screen printing using a conductive paste in the configuration of the electron-emitting device of the flat panel display, and the lower electrode is formed by the shape of the conductive paste formed on the substrate during printing at the same time as the signal is applied to the lower electrode. A method of enabling an electrode to even serve as a focusing electrode.

The screen printing method uses a paste having a constant viscosity and passes it through a patterned mask mesh to be applied onto a substrate. Coating is evenly distributed on the entire mask. It is a first step, and consists of two steps of depositing on a substrate by applying pressure to the applied paste on a mask called a squeegee.

In the past, screen printing has been used as the main device of printers for printing documents, and has the characteristics of uniform height and fine spacing in paste distribution, and above all, inexpensive process equipment and uniform height This has the advantage of being possible.

In addition, the present invention is characterized in that the carbon-based material is used as the electron-emitting device.

Carbon-based materials such as carbon nanotubes (CNTs), diamond-like carbon (DLC), graphit nanofiber (GNF), and graphite emit mechanical electrons under a much lower electric field than applying a high field to the tip for electron emission. With the discovery of chemical stability, the application of flat panel devices to electron-emitting devices based on vacuum technology is being made.

Therefore, the present invention uses a carbon-based material having a characteristic of drawing electrons at a low electric field, and a separate process required for manufacturing a focusing electrode in a conventional electron-emitting device has a low cost such as a screen printing device and spin-coating. Presenting an idea that can be solved only by the bottom electrode manufacturing process using the equipment of the, to configure an electron-emitting device that can be applied to a large area of low cost on the plane.

The present invention improves the existing complicated and expensive process for constructing an electron-emitting device, using a carbon-based material as the electron-emitting device, and using a screen printing method using a conductive paste suitable for printing. It is the biggest feature that the low-cost large-area application is made possible by preparing a lower electrode having a role to serve as a focusing electrode for controlling the concentration of electrons emitted.

The conductive paste formed at a uniform and precise interval on the plane by the screen printing method has a certain angle in the direction of the substrate by gravity depending on the viscosity of the paste and the thickness of the paste applied by the screen printer due to the characteristics of the paste itself having a viscosity. Paste flow occurs that changes the original shape.

A carbon-based material emitting electrons at a low electric field on the lower electrode thus formed is formed by a method such as photo-lithography or spin coating, and an insulating layer and an electron withdrawing electrode are sequentially formed.

1A shows a structure of a lower electrode having a focusing function formed using the screen printing method according to the present invention, a carbon-based electron emitting device, an insulating layer, and an electron extracting electrode formed thereon.

In order to apply a voltage to the carbon-based electron-emitting device 201, a lower electrode 202 having a predetermined slope is formed by a screen printing method, and a voltage difference between the electron-out electrode 204 and the lower electrode 202 is determined. An insulating layer 203 for holding is positioned between the electron withdrawing electrode 204 and the lower electrode 202.

The lower electrode lead wire 205 for applying a signal to the lower electrode is formed in connection with the lower electrode, and the electron drawing electrode lead wire 206 for applying a signal to the electron withdrawing electrode is provided with the lower electrode lead wire and the insulating layer 203. It is separated and connected to the electron withdrawing electrode.

FIG. 1B is a cross-sectional view taken along the line A-A 'of the structure shown in FIG. 1A.

The conductor paste for the lower electrode 202 applied by the screen printing method is formed on the substrate 207 with a constant inclination.

A carbon-based electron-emitting device 201 is formed between the formed lower electrodes, and an insulating layer 203 is positioned between the electron-drawing electrode 204 and the lower electrode 202 serving as a focusing function.

2 is a view illustrating emission characteristics of electrons emitted from an electron emission device when a lower electrode having a focusing function according to the present invention is used.

The electrons emitted from the electron-emitting device are emitted in a simple structure without the focusing electrode formed in parallel with the electron-emitting electrode layer required by the tip-type electron-emitting device or the focusing electrode formed vertically on the electron-emitting electrode. You can see it going straight without doing.

3A to 3B illustrate an example of a manufacturing process of forming an electron-emitting device by applying carbon paste onto a substrate using the screen printing printer method of the present invention.

a) A conductive paste having a certain viscosity is formed on the substrate by using a screen printing method. The conductive paste formed on the substrate has a constant inclination.

b) A carbon-based material is formed on the conductive paste formed on the substrate. The carbon-based material may be formed directly using chemical vapor deposition (CVD), or the like, and the carbon material may be mixed with a photoresist to produce a liquid phase, and then widely used for pattern formation. Many methods are possible, such as forming through the exposure process used.

c) A carbon material protective layer is formed because the carbon material may be damaged in the process proceeded to form the electron withdrawing electrode.

d) The formation of the insulating layer is formed on the protective layer by a method using a photosensitive insulating material, a printing material or the like.

e) Electron drawing electrode layer is formed on the insulating layer using a printing method or a general thin film deposition method.

f) Finish the process by removing the protective layer covering the carbon material.

Specific embodiments of the present invention will be described with reference to FIG. 4.

Referring to FIG. 4, electron-emitting devices are formed on the lower substrate, and each electron-emitting device is simultaneously formed through the above-described process.

When a voltage is applied to the electron withdrawing electrode, electrons are emitted from the carbon-based material due to the voltage difference between the electron withdrawing electrode and the lower electrode.

The emitted electrons emit an electron beam having excellent straightness by the lower electrode, which serves as a focusing electrode, and the emitted electron beam is accelerated toward the upper substrate to which the high pressure is applied and hits the phosphor formed on the upper substrate. Will be released.

As described above, the present invention uses a screen printing method, which is widely used to control the divergence of an electron beam, which is a problem when emitting electrons from an electron emitting device through a drawing electrode, and thus, a conductive paste is used for the lower electrode and the focusing electrode. Forming a carbon-based material having a characteristic of emitting electrons under a low electric field in a paste state having a predetermined viscosity as an electron-emitting device and forming it on the substrate, thereby forming an electron-emitting device. By avoiding the focusing electrode forming process, which is an additional process for reducing the spreading of the electron beam emitted from the electron emitting device when forming the conventional electron emitting device, the overall number of processes can be reduced, and the role of the focusing electrode can be reduced. Screen printers that require low cost By applying the step, and at the same time constituting the electron-emitting device of low cost and high efficiency, it is to achieve a structure in which a large-area application easy.

As a result of the present invention, in order to reduce the divergence of the electron beam, the focusing electrode formation fixing, which requires a high cost, is eliminated, and the lower electrode is manufactured by using a screen printing method to manufacture the shape of the focusing electrode. In addition, by forming a tip type electron-emitting device having problems such as mass production and large-area application using a carbon-based material that emits electrons at a low electric field, it solves the existing problems of simplicity and aspect application. It is possible to do

Claims (9)

An electron emitting device of a flat panel display device that emits electrons by applying an electric field applied to an electron extraction electrode, An electron-emitting device, characterized in that the lower electrode is formed to have a slope with respect to the flat substrate. The method of claim 1, And the electron-emitting device is formed in a space between the lower electrodes. The method of claim 1, And an insulating layer formed on an upper surface of the lower electrode to correspond to the lower electrode. The method of claim 3, wherein And an electron-emitting electrode formed on the upper surface of the insulating layer to correspond to the insulating layer. The method of claim 1, The lower electrode has an electron emission device, characterized in that it has a pattern of a circle, a square, a linear. The method of claim 1, And the lower electrode serves as a focusing electrode. The method of claim 1, The electron-emitting device of claim 1, wherein the electron-emitting devices are made of at least one carbon-based material of carbon nanotubes (CNTs), diamond like carbon (DLC), graphit nanofibers (GNF), and graphite. The method of claim 2, The electron-emitting device is characterized in that it has a pattern of circular, square, linear and the like. A process of forming an electron-emitting device by coating carbon paste on a substrate using a screen printing method, Forming a conductive paste having a predetermined viscosity on the substrate by a screen printing method; Forming a carbon-based material on the conductive paste formed on the substrate; Forming a carbon material protective layer; Forming an insulating layer over the protective layer; Forming an electron extracting electrode layer on the insulating layer by using a printing method or a general thin film deposition method; An electron-emitting device manufacturing method comprising a finishing process of removing a protective layer covering a carbo material.