KR20060104367A - Electron emission device - Google Patents

Abstract

A first substrate and a second substrate disposed to face each other at a predetermined interval, an electron emission portion formed on the first substrate to emit electrons from the first substrate toward the second substrate, and formed on the second substrate Light emitting parts emitted by electrons emitted from the electron emission parts of the first substrate and an effective screen area set on the first and second substrates to maintain a gap between the first and second substrates. And a getter disposed to surround the spacer.

Cathode electrode, gate electrode, insulating layer, electron emission part, spacer, getter mounting.

Description

Electron emission device

1 is a partial cross-sectional view of an electron emission device according to the present invention.

2 is a perspective view showing an extract of a spacer and a getter installed on a substrate according to the present invention.

3 is a plan view of an electron emission device according to the present invention.

TECHNICAL FIELD The present invention relates to an electron emitting device, and more particularly, to an electron emitting device having an improved mounting state of a getter for maintaining an internal vacuum state in a high vacuum state.

In general, the electron emission device may be classified into a method using a hot cathode and a cold cathode according to the type of the electron source.

Here, the electron-emitting device using a cold cathode is a field emitter array (FEA) type, surface conduction emission (SCE) type, metal-insulator-metal-insulator- metal (MIM) type and metal-insulator-semiconductor (MIS) type and the like are known.

The MIM type and the MIS type electron emission devices each form an electron emission portion having a metal / insulation layer / metal (MIM) and a metal / insulation layer / semiconductor (MIS) structure, and are disposed between two metals having an insulation layer therebetween, or When a voltage is applied between the metal and the semiconductor, a principle is used in which electrons are moved and accelerated from a metal having a high electron potential or from a semiconductor to a metal having a low electron potential.

The SCE-type electron emission device forms an electron emission portion by providing a conductive thin film between the first electrode and the second electrode disposed to face each other on a substrate, and providing a micro crack to the conductive thin film. When the current flows to the surface of the conductive thin film by applying it, the principle that the electron is emitted from the electron emission portion.

The FEA type electron emission device uses a principle that electrons are easily emitted by an electric field in vacuum when a material having a low work function or a large aspect ratio is used as the electron source, and molybdenum (Mo) Alternatively, an example has been developed in which a tip structure mainly made of silicon (Si) or the like is used, or a carbon-based material such as carbon nanotubes, graphite, or diamond-like carbon is used as an electron source.

As such, the electron emission device using the cold cathode basically includes driving electrodes for controlling electron emission of the electron emission unit along with an electron emission unit on the first of the two substrates constituting the vacuum container, and a fluorescent layer on the second substrate. In addition, an electron acceleration electrode for efficiently accelerating electrons emitted from the first substrate side toward the fluorescent layer is used to perform a predetermined light emission or display function.

On the other hand, when the sintering or bonding of the upper and lower substrates is completed as described above, the gas inside the panel using a pump while heating the panel in order to mount a getter in the exhaust tube and remove moisture (H ₂ O) in the panel. To the outside chamber.

 When the degree of vacuum inside the panel reaches a desired level during exhaust, the panel and the outer chamber are isolated by a pinch-off process that cuts the middle portion of the exhaust tube by using a local heating device installed adjacent to the exhaust tube.

 At this time, since the internal vacuum degree of the insulated panel falls again upon punch-off, the process of restoring the vacuum degree by activating the getter at high temperature is continued.

 In general, the method of mounting the getter is to mount the getter inside the panel before joining the upper and lower substrates, and to mount the getter just above the pinch-off point in the exhaust tube after joining the substrate. There is a way to insert the getter by installing it.

The method of pre-mounting the getter in the panel has an advantage that the gas adsorption efficiency for the field emission array is relatively high when the getter is mounted in the panel close to the field emission array.

However, the method of pre-mounting the getter inside the panel attaches the getter to the upper substrate, so that one side of the getter adhered to the upper substrate does not adsorb gas, so the gas adsorption efficiency cannot be increased beyond a certain limit and in the atmospheric atmosphere. There is a disadvantage that the getter may be contaminated during the main sintering of the frit glass to be done.

In addition, when the gutter is inserted into the getter exhaust pipe, the damage of the getter becomes relatively large when tip-off of the exhaust pipe is made. In the case of making a separate gutter room, the thickness of the panel increases, thus increasing the labor of manufacturing the panel. Has a problem that is relatively increased.

On the other hand, the non-evaporable getter is formed by vapor deposition or sputtering, but in the formation thereof, it is necessary to avoid the pattern of the electron emitting portion and the phosphor, and has a problem in the manufacturing process that an accurate masking treatment is required. have. If the masking becomes insufficient and the electron emission portion is contaminated by the deposition method or the like, it will affect the electron emission characteristics and shorten the life of the flat display device.

 Several methods for forming a non-evaporable getter have also been proposed as a film forming method other than the vapor deposition method and the sputtering method. For example, Japanese Patent Laid-Open No. 5-159697 proposes a method for producing a non-evaporable getter by powder processing forming or powder pressing sintering.

 However, in the method disclosed in this publication, cracks and deformations are liable to occur during sintering due to the distribution of shrinkage ratios, etc., and constraints such that a non-evaporable getter having a complex shape cannot be formed, or powder generation due to powder molding There are problems such as this.

As a method of arranging and fixing a non-evaporable getter formed by a powder press-molding sintering method or the like inside a flat panel display device, for example, as disclosed in Japanese Patent Application Laid-Open No. 2000-311638, a non-evaporable getter is obtained by using an adhesive. A method of fixing is proposed. In this method, however, masking is difficult when applying the adhesive, and depending on the type of adhesive, gas is released from the adhesive during or after the heat-activating treatment of the getter, and the gas absorption capacity of the getter is reduced or the electric field is released. There is a fear that the electron emission characteristics may be degraded due to contamination of the mold. Moreover, in order to prevent such inconvenience, there also exists a problem of requiring research for preventing the degassing from an adhesive agent.

Therefore, especially in flat display devices, the arrangement of the non-evaporable getter was very difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electron emission device capable of increasing adsorption efficiency of gas to a getter and preventing an effective screen from being reduced due to the getter.

It is still another object of the present invention to provide an electron emission device capable of improving fixability of a getter.

Still another object of the present invention is to provide an electron emission device capable of fundamentally preventing the movement of the getter container from heat deformation and external impact, and further increasing the vacuum degree of the space partitioned between the upper and lower substrates. In providing.

Another object of the present invention is to provide an electron emitting device that is easy to install a non-evaporable getter.

In order to achieve the above object, the electron emitting device according to the present invention,

A first substrate and a second substrate disposed to face each other at a predetermined interval, an electron emission portion formed on the first substrate to emit electrons from the first substrate toward the second substrate, and formed on the first substrate Light emitting parts emitted by electrons emitted from the electron emission parts of the first substrate and an effective screen area set on the first and second substrates to maintain a gap between the first and second substrates. And a getter disposed to surround the spacer.

The getter may be provided in a donut shape and inserted into the spacer so that the spacer is disposed therein.

The getter may be formed by being coated on an outer circumferential surface of the spacer.

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 an electron emitting device according to a first embodiment of the present invention.

Referring to the drawings, the electron emission device includes a first substrate 2 and a second substrate 4 which are arranged in parallel to each other to form an internal space. Among these substrates, the first substrate 2 is provided with a configuration for emitting electrons, and the second substrate 4 is provided with a configuration in which visible light is emitted by electrons to cause any light emission or display.

First, on the first substrate 2, the cathode electrodes 6, which are the first electrodes, have a predetermined pattern, for example, a stripe shape, and are arranged in a plurality of directions along one direction of the first substrate 2 at arbitrary intervals from each other. Is formed. The insulating layer 8 is formed on the entire first substrate 2 while covering the cathode electrodes 6.

On the insulating layer 8, a plurality of gate electrodes 10, which are second electrodes, are formed in a predetermined pattern, for example, in a stripe shape, along a direction orthogonal to the cathode electrode 6 at arbitrary intervals from each other. .

When the region where the cathode electrode 6 and the gate electrode 10 cross each other is defined as a pixel region, one or more openings 12 are formed in the gate electrode 6 and the insulating layer 8 in each pixel region to form a cathode electrode ( Expose some surface of 6). An electron emission portion 14 is formed on the cathode electrode 6 inside the opening 12. The electron emission portion 14 is electrically connected thereto in contact with the cathode electrode 6.

The planar shape of the electron emission unit 14, the number and arrangement form per pixel area, etc. are not limited to the illustrated example and may be variously modified.

The electron emission unit 14 is formed of materials that emit electrons when an electric field is applied, such as a carbon-based material or a nanometer-sized material. Preferred materials for use as the electron emission portion 14 include any one of carbon nanotubes, graphite, graphite nanofibers, diamond, diamond-like carbon, C ₆₀ , silicon nanowires, or a combination thereof. Printing, direct growth, chemical vapor deposition or sputtering can be applied.

In this configuration an insulating layer 8 is arranged between the cathode electrodes 6 and the gate electrodes 10 to electrically insulate the two electrodes.

Next, a fluorescent layer 16 and a black layer 18 are formed on one surface of the second substrate 4 facing the first substrate 2, and aluminum is disposed on the fluorescent layer 16 and the black layer 18. An anode electrode 20 made of a metal film such as is formed. The anode electrode 20 receives a high voltage necessary for accelerating the electron beam from the outside, and reflects the visible light emitted toward the first substrate 2 of the visible light emitted from the fluorescent layer 16 toward the second substrate 4 side of the screen. It increases the brightness.

The anode electrode may be made of a transparent conductive film such as indium tin oxide (ITO) instead of a metal film. In this case, the anode electrode may be positioned on one surface of the fluorescent layer facing the second substrate and the black layer, and may be formed in plural in a predetermined pattern.

The first substrate 2 and the second substrate 4 described above are integrally formed by the glass frit 5 applied around the substrate at random intervals while the gate electrode 10 and the anode electrode 20 face each other. Is bonded to each other to form an electron-emitting device by evacuating the internal space and maintaining it in a vacuum state.

In the electron emitting device as described above, the first and second substrates 2 and 4 are formed outside the effective screen area 100 of the electron emitting device around the application area of the glass frit 5. A plurality of spacers 40 for maintaining the spacing therebetween are provided (see FIG. 3).

The spacer 40 is provided as a post of a circular or polygonal shape and is disposed on the side adjacent to the glass frit 5 as shown in FIG. 2, and the outer side of the spacer 20 surrounds the spacer 20. The getter 42 is formed in the form.

In the present embodiment, the spacer 40 is formed in a cylindrical shape, and the getter 42 is provided in a donut shape and inserted into the spacer 40 so as to be disposed therein.

At this time, an outer circumferential surface of the spacer 40 may be formed with concavities and convexities to reinforce the mutual coupling force between the getter 42 and the spacer 40, and on the other hand, the outer circumferential surface roughness of the space 40 may be relative. It can also be formed large.

Here, the getter 42 is applicable to either evaporation type or non-evaporation type.

In addition, when the spacer 40 is provided, the getter 42 may be provided in the form of a coating treatment on the surface thereof.

Since the getter is arranged along the circumference of the effective screen region, the electron-emitting device having such a configuration can advantageously bring about an improvement in the degree of vacuum with respect to the vacuum panel formed by the first and second substrates during the manufacturing process.

This is because the getter is provided in a large number in the vacuum panel, and is distributed evenly inside the vacuum panel centering on the effective screen area without focusing on any one side inside the vacuum panel as in the prior art.

Further, even in the mounting surface of the getter, in the present invention, since the getter is connected to the spacer and is installed on the outer circumference of the spacer, the getter can be strengthened and the utilization thereof can be improved.

On the other hand, the present invention is not limited to the FEA type electron emitting device of the above embodiment, but is easily applied to other electron emitting devices.

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. Of course it belongs to the range of.

As such, the electron-emitting device according to the present invention may have a foundation capable of producing a high-quality product by improving the degree of vacuum inside the vacuum panel due to the increased number of getters.

Claims (6)

A first substrate and a second substrate disposed to face each other at a predetermined interval; An electron emission part formed on the first substrate to emit electrons from the first substrate toward the second substrate; A light emitting part formed on the second substrate and emitting light by electrons emitted from the electron emitting part of the first substrate; A spacer disposed outside the effective screen area set on the first and second substrates to maintain a gap between the first and second substrates; And Getters that wrap around this spacer Electron emitting device comprising a. The method of claim 1, The getter is provided in a donut shape and is inserted into the spacer so that the spacer is disposed therein. The method of claim 1, The getter is formed by coating the outer peripheral surface of the spacer. The method of claim 1, Electron emission device in which the spacer is formed in a cylindrical shape. The method of claim 1, And a plurality of spacers and the getters are provided along the edges of the first and second substrates. The method according to any one of claims 1 to 5, And the getter is an evaporation type or non-evaporation type.

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