KR20080035121A - Spacer for Electron Emission Display and Electron Emission Display - Google Patents

Abstract

The spacer for an electron emission display according to the embodiment of the present invention includes a mother and a protrusion formed on the side of the mother. On the other hand, the electron emission display according to the embodiment of the present invention, the first substrate and the second substrate facing each other, the electron emission unit provided on one surface of the first substrate, the light emitting unit provided on the second substrate, and the first And a spacer disposed between the substrate and the second substrate, the spacer including a mother and a protrusion formed on the side of the mother.

Description

Spacer for electron emission display and Electron emission display

1 is a partially exploded perspective view of an electron emission display according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

3 is a perspective view illustrating main parts of a spacer of an electron emission display according to an exemplary embodiment of the present invention.

4 is an enlarged cross-sectional view of a portion IV-IV of FIG. 1.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission display, and more particularly, to spacers installed inside a vacuum vessel to support a compressive force applied to the vacuum vessel and an electron emission display having the spacers.

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

The electron emission device using the cold cathode may include a field emission array (FEA) type, a surface conduction emission type (SCE) type, and a metal-insulating layer-metal type. Metal (MIM) type and Metal-Insulator-Semiconductor (MIS) type are known.

The FEA type electron emission element includes an electron emission portion and a cathode electrode and a gate electrode as driving electrodes for controlling electron emission of the electron emission portion. Here, the electron emitting portion may be a material having a low work function or a high aspect ratio, for example, a tip structure having a sharp tip mainly made of molybdenum (Mo) or silicon (Si), or carbon nanotubes, graphite, and diamond. It can be constructed using carbon-based materials such as phase carbon, which utilize the principle of easily emitting electrons by an electric field in vacuum.

On the other hand, the electron emission elements are formed in an array on one substrate to form an electron emission device, and the electron emission device is combined with another substrate having a light emitting unit composed of a fluorescent layer and an anode electrode to emit electrons. A display (electron emission display) is constructed.

In the electron-emitting display, two substrates have a sealing member such as a frit at the edge thereof, and the two substrates are bonded to each other to form a vacuum container having an internal space, wherein the vacuum container has an approximately 10 internal space. ^It is maintained at a vacuum of ^-6 Torr.

Such a vacuum container receives a strong compressive force due to the pressure difference between the inside and the outside, and the compressive force increases in proportion to the screen size.

The vacuum vessel thus comprises a plurality of spacers therein, which maintain a constant spacing between the two substrates against the atmospheric pressure applied to the vacuum vessel. In this case, the spacer is mainly made of a dielectric such as glass or ceramic so that the driving electrodes on one substrate and the anode electrode on the other substrate are not shorted through the spacer.

The spacer is exposed to the inner space of the vacuum in which the flow of electrons continuously occurs and collides with the electrons emitted from the electron emitter, which leads to charging of the spacer and distorts the path of the electron beam. In order to prevent this, a structure is disclosed in which a coating layer is added to a surface of a conventional spacer and the coating layer is contacted with an electrode to discharge charge charged on the surface of the spacer.

However, the coating layer as described above has a problem that the thickness of the coating layer is poor, resulting in poor contact with the electrode, and even when formed as a double layer, it is added to the front surface of the spacer without considering the respective resistance value, thereby degrading the current carrying efficiency.

Accordingly, an object of the present invention is to provide a spacer having a structure for smoothing current flow and an electron emission display having the same.

In order to achieve the above object, the spacer for an electron emission display according to the embodiment of the present invention includes a mother and a protrusion formed on the side of the mother.

The protrusion is formed of metal.

In addition, the protrusions are formed spaced apart at predetermined intervals on the side of the parent, the planar shape is circular.

At this time, the diameter of the protrusions is 5 μm or less, and the interval between the protrusions is 2.5 to 5 μm.

In addition, the thickness of the protrusion is 1000 to 5000 mm 3.

The protrusion is made of at least one material selected from the group consisting of a material which does not occur oxidation below 500 ° C., for example, gold (Au), platinum (Pt), and aluminum (Al).

On the other hand, the electron emission display according to the embodiment of the present invention, the first substrate and the second substrate facing each other, the electron emission unit provided on one surface of the first substrate, the light emitting unit provided on the second substrate, and the first And a spacer disposed between the substrate and the second substrate, the spacer including a mother and a protrusion formed on the side of the mother.

The electron emission unit may be formed on a first electrode on a first substrate, a first electrode formed along one direction of the first substrate, a second electrode formed along a direction crossing the first electrode with an insulating layer therebetween, and a first electrode formed on the first electrode. And an electron emission unit electrically connected to the first electrode.

And a focusing electrode disposed on the first electrode and the second electrode while maintaining insulation from the first electrode and the second electrode.

The electron emission unit is made of at least one material selected from the group consisting of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, fullerenes (C ₆₀ ), and silicon nanowires.

The light emitting unit includes a fluorescent layer formed on the second substrate and an anode electrode formed on the second substrate while being connected to the fluorescent layer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a partially exploded perspective view of an electron emission display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

1 and 2, an electron emission display according to an exemplary embodiment of the present invention includes a first substrate 10 and a second substrate 12 disposed to be parallel to each other at predetermined intervals. The 1st board | substrate 10 and the 2nd board | substrate 12 are joined by the sealing member (not shown) arrange | positioned at the edge, and comprise the container which has an internal space. The vessel is evacuated to a vacuum of approximately 10 ⁻⁶ Torr to constitute a vacuum vessel consisting of the first substrate 10, the second substrate 12, and the sealing member.

On the surface of the first substrate 10 facing the second substrate 12, electron emission elements are provided in the electron emission unit 100 forming an array, and the second substrate 12 facing the first substrate 10. The light emitting unit 110 includes a fluorescent layer, an anode electrode, and the like on the surface of the substrate.

The first substrate 10 provided with the electron emission unit 100 and the second substrate 12 provided with the light emission unit 110 combine to form an electron emission display.

The vacuum vessel of the above-described configuration may include other electrons including field emission array (FEA) type, surface conduction emission (SCE) type, metal-insulating layer-metal (MIM) type, and metal-insulating layer-semiconductor (MIS) type. Applicable to an emissive display, the following is more specifically described by taking a field emission array (FEA) type electron emissive display as an example.

First, cathode electrodes 14 are formed on the first substrate 10 in a stripe pattern along one direction (y-axis direction in FIG. 1) of the first substrate 10.

The first insulating layer 16 is formed on the entire first substrate 10 while covering the cathode electrodes 14, and the gate electrodes 18 are formed on the first insulating layer 16 with the cathode electrodes 14. It is formed in a stripe pattern along the direction orthogonal (the x-axis direction in FIG. 1).

As a result, an intersection region of the cathode electrode 14 and the gate electrode 18 is formed, and the intersection region may constitute one unit pixel. Electron emitters 20 are formed in each unit pixel on the cathode electrodes 14.

In addition, first and second openings 161 and 181 corresponding to the electron emission parts 20 are formed in the first insulating layer 16 and the gate electrodes 18, respectively, on the first substrate 10. The electron emitting portion 20 is exposed. That is, the electron emission part 20 is formed on the cathode electrode 14 while being disposed in the first and second openings 161 and 181 of the first insulating layer 16 and the gate electrode 18. In the present embodiment, the electron emitting portion and the first and second openings are formed in a circular shape with respect to the planar shape, but these shapes are not necessarily limited to the illustrated example.

In the present embodiment, the electron emission unit 20 is formed of materials emitting electrons when a electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. That is, the electron emission unit 20 is composed of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbon, fullerene (C ₆₀ ), silicon nanowires, and combinations thereof. On the other hand, the electron emission unit 20 may be formed of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si).

The electron emitters 20 may be provided in plural in each unit pixel area, and the plurality of electron emitters 20 may be any one of the cathode electrode 14 and the gate electrode 18, for example, a cathode. The electrodes 14 may be positioned in a line at an arbitrary distance from each other along the longitudinal direction of the electrodes 14. Of course, the arrangement state of the electron emission units for each unit pixel is not limited to this and can be variously modified.

The second insulating layer 22 and the focusing electrode 24 are sequentially formed on the gate electrodes 18. The second insulating layer 22 disposed below the focusing electrode 24 is formed on the front surface of the first substrate 10 to cover the gate electrodes 18 to insulate the gate electrode 18 and the focusing electrode 24. Let's do it.

In addition, the focusing electrode 24 is formed of one film having an arbitrary size on the second insulating layer 22.

Third and fourth openings 221 and 241 are also formed in the second insulating layer 22 and the focusing electrode 24 to pass the electron beam.

In the present exemplary embodiment, the third opening 221 of the second insulating layer 22 and the fourth opening 241 of the focusing electrode 24 collectively focus electrons emitted from one unit pixel. However, the present invention is not limited thereto, and openings corresponding to the electron emission units may individually collect electrons emitted from each electron emission unit.

Next, on one surface of the second substrate 12 opposite to the first substrate 10, the fluorescent layer 26, for example, the red, green, and blue fluorescent layers 26R, 26G, and 26B may be separated from each other. It is formed at intervals, and a black layer 28 is formed between the fluorescent layers 26R, 26G, and 26B to improve contrast of the screen. The fluorescent layer 26 may correspond to one unit pixel for each unit pixel set in the first substrate 10.

An anode electrode 30 made of a metal such as aluminum (Al) is formed on the fluorescent layer 26 and the black layer 28. The anode electrode 30 receives the high voltage necessary for accelerating the electron beam from the outside to maintain the fluorescent layer 26 in a high potential state, and visible light emitted toward the first substrate 10 of the visible light emitted from the fluorescent layer 26. Is reflected toward the second substrate 12 to increase the brightness of the screen.

Meanwhile, in another embodiment of the present invention, the anode electrode may be made of a transparent conductive film such as indium tin oxide (ITO). This anode electrode is located between the second substrate and the fluorescent layer. Furthermore, in another embodiment of the present invention, the anode electrode may use the above-described transparent conductive film, and a structure in which a metal film is further formed thereon.

In addition, a plurality of spacers 32 are provided between the first substrate 10 and the second substrate 12 to maintain a constant gap between the two substrates 10 and 12 against the atmospheric pressure applied to the vacuum container. Is placed.

The spacers 32 are disposed on the focusing electrode 24 on the first substrate 10 side, and are disposed corresponding to the black layer 28 on the second substrate 12 side so as not to invade the fluorescent layer 26.

In the present embodiment, the spacer 32 includes a mother 321 and a protrusion 322 formed on the side surface of the mother 321.

3 is a partial perspective view of a spacer according to the present embodiment, and FIG. 4 is an enlarged cross-sectional view of a portion of the spacer IV-IV of FIG. 3.

As shown in FIGS. 3 and 4, the matrix 321 is formed in a wall shape, for example, and may be made of a material such as glass or ceramic.

A plurality of protrusions 322 are formed on the side surface of the matrix 321 exposed to the air in the vacuum container, spaced apart from each other at predetermined intervals.

The protrusion 322 may be formed in patterns having a circular surface shape, for example, a cylinder or hemispherical shape, on the side surface of the parent body 321. Here, in the case where the protrusions 322 are cylindrically spaced with a circular surface shape, the diameter r of the protrusions 322 is 5 μm or less, and the spacing between each of the protrusions 322 ( d) is 2.5-5 탆.

In addition, the protrusion 322 has a thickness t of 1000 to 5000 mm 3 and protrudes from the side of the mother body.

The structure of the protrusion 322 increases the surface roughness of the spacer matrix 321, thereby providing an effect of reducing the secondary electron emission coefficient.

The electron beams exposed inside the vacuum vessel impinge on the spacer surface at a predetermined angle of incidence. Due to this collision, secondary electrons are emitted from the spacer. As described above, when the embossed protrusion 322 is formed on the surface of the spacer 32, the secondary electrons are emitted from the spacer 32 with a predetermined emission angle compared to the smooth surface. Interferes with the movement of secondary electrons. Therefore, the spacer 32 of the present embodiment has a reduced secondary electron emission coefficient compared with the spacer having a smooth surface.

The protrusion 322 is made of a material that does not occur at 500 ° C. or less, and may be formed of metal particles such as gold (Au), platinum (Pt), and aluminum (Al). These materials have a specific resistance value of about 1 to 3 Ωcm and can smoothly flow current so as to discharge charges accumulated on the surface of the spacer 32 to the outside. It can also provide the effect of repelling the electron beam attracted to the spacer 32.

The protrusion 322 may be formed on the side surface of the spacer 32 using a screen mask. For example, after fixing the screen mask to the side of the spacer 32, metal particles are deposited using a sputtering method or the like. Then, the circular protrusion 322 is patterned on the surface of the spacer 32 through a mesh hole formed in the screen mask.

In the structure of the spacer 32 described above, the protrusion 322 is formed on the side surface of the matrix 321 to reduce the resistance of the entire spacer 32, thereby effectively preventing the charging of the spacer 32.

In addition, the protrusion 322 is protruded from the side of the parent 321, and is effective in reducing the emission coefficient of the secondary electrons emitted from the spacer 32 surface.

In the present embodiment, only the matrix formed into a wall was described. The shape is not limited thereto, and may be variously modified, such as a circular columnar shape or a square columnar shape. have.

Next, the driving process of the above-described electron emission display will be described.

The electron emission display is driven by supplying a predetermined voltage from outside to the cathode electrodes 14, the gate electrodes 18, the focusing electrode 24, and the anode electrode 30.

For example, any one of the cathode electrodes 14 and the gate electrodes 18 receives a scan driving voltage to serve as scan electrodes, and the other electrodes receive a data driving voltage to serve as data electrodes.

In addition, the focusing electrode 24 receives a voltage required for electron beam focusing, for example, 0 volts (V) or a negative DC voltage of several to collection volts (V), and the anode electrode 30 is required for accelerating the electron beam, for example, several hundreds. DC voltage of positive to thousands of volts (V) is applied.

As a result, an electric field is formed around the electron emission unit 20 in the unit pixels in which the voltage difference between the cathode electrode 14 and the gate electrode 18 is greater than or equal to the threshold, thereby emitting electrons from the electron emission unit 20. The emitted electrons are focused to the center of the electron beam bundle while passing through the second opening 241 of the focusing electrode 24, and are attracted by the high voltage applied to the anode electrode 30 to impinge on the fluorescent layer 26 of the corresponding unit pixel. do. This collision causes the fluorescent layer 26 to emit light to produce an arbitrary image.

In the above-described driving process, the electron emission display of the present embodiment can reduce the amount of charge accumulated in the spacer 32 because the total resistance of the spacer 32 is reduced and current flows smoothly.

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.

The electron emission display according to the embodiment of the present invention forms a metal layer having a small resistance value on the surface of the spacer exposed to vacuum, thereby reducing the resistance of the entire spacer and facilitating the flow of current, thereby charging the charge on the surface of the spacer. Can be discharged smoothly, and the pushing force can be provided to the electron beam passing through the inside of the vacuum container.

Therefore, it is possible to effectively prevent the phenomenon that the electron beam path is distorted by reducing drag and collision of the electron beam with respect to the charged spacer.

Such distortion prevention of the electron beam path may provide a high-quality image by accurately emitting a fluorescent layer corresponding to the electron emission part and realizing an accurate color accordingly.

Claims (22)

In the spacer for an electron emission display, matrix; And Protrusion formed on the side of the mother Spacer for an electron emission display comprising a. According to claim 1, A spacer for an electron emission display in which the protrusion is formed of a metal. The method according to claim 1 or 2, And a protrusion formed on the side surface of the mother body at predetermined intervals. According to claim 1, And the protrusion is circular in planar shape. The method of claim 4, wherein A spacer for an electron emission display having a diameter of the protruding portion of 5 μm or less. The method of claim 3, wherein A spacer for an electron emission display having a spacing between the protrusions of 2.5 to 5 μm. According to claim 1, And a thickness of the protrusion is 1000 to 5000 mm 3. The method of claim 2, The protrusion is an electron emission display spacer made of a material that does not occur below 500 ° C. The method according to claim 1 or 8, The protrusion may include at least one material selected from the group consisting of gold (Au), platinum (Pt), and aluminum (Al). According to claim 1, And said matrix is wall-shaped. A first substrate and a second substrate disposed to face each other; An electron emission unit provided on one surface of the first substrate; A light emitting unit provided on one surface of a second substrate facing the first substrate; And A spacer disposed between the first substrate and the second substrate Including, The spacer, matrix; And Protrusion formed on the side of the mother Electronic emission display comprising a. The method of claim 11, wherein An electron emission display in which the protrusions are formed of metal. The method of claim 11 or 12, And the protrusions formed on the side surfaces of the mother body at predetermined intervals. The method of claim 11, wherein And the protrusion is circular in planar shape. The method of claim 14, And an electron emission display having a diameter of 5 mu m or less. The method of claim 13, An electron emission display wherein the spacing between the protrusions is between 2.5 and 5 μm. The method of claim 11, wherein And the thickness of the protrusion is 1000 to 5000 mm 3. The method of claim 12, The protrusion is an electron emission display made of a material that does not occur oxidation below 500 ° C. The method of claim 11 or 18, The protrusion may include at least one material selected from the group consisting of gold (Au), platinum (Pt), and aluminum (Al). The method of claim 11, wherein The electron emission unit, A first electrode formed on the first substrate along one direction of the first substrate; A second electrode formed along the direction crossing the first electrode with an insulating layer interposed therebetween; And And an electron emission unit formed on the first electrode and electrically connected to the first electrode. The method of claim 20, And a focusing electrode which is insulated from the first electrode and the second electrode and positioned above the first electrode and the second electrode. The method of claim 11, wherein The light emitting unit, A fluorescent layer formed on the second substrate; And An anode electrode formed on the second substrate while being connected to the fluorescent layer Electronic emission display comprising a.

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