KR20080036781A - Electron emission device, manufacturing method of the device, and light emission device using the same - Google Patents

Abstract

An electron emission device, a manufacturing method thereof, and a light emitting device using the same are provided to prevent emission error by supplying driving currents in an electron emitting unit through a conductive path even when shrinking is generated in the electron emitting unit. An electron emission device includes a substrate, a cathode electrode, and electron emitting units(20). The cathode electrode includes a main electrode(141), a resistive layer(143), and a connection electrode(142). The main electrode is elongated along a direction of the substrate. The resistive layer having apertures(143a) is connected to the main electrode. The connection electrode, which is disposed in the apertures, is connected to the resistive layer. The electron emitting units, which are positioned at the apertures, are connected to the connection terminal.

Description

ELECTRON EMISSION DEVICE, MANUFACTURING METHOD OF THE DEVICE, AND LIGHT EMISSION DEVICE USING THE SAME

1 is a partially exploded perspective view of a light emitting device according to an embodiment of the present invention.

2 is a partial cross-sectional view of a light emitting device according to an embodiment of the present invention.

3 is a partial plan view of a cathode electrode of an electron emitting device according to an embodiment of the present invention.

4 is a partial plan view of a cathode electrode shown for explaining a modification of the connection electrode of the electron emission device according to an embodiment of the present invention.

5A-5I are schematic diagrams at each manufacturing step shown to illustrate a method of manufacturing an electron emitting device according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emission device, and more particularly, to an electron emission device having a resistive layer formed on a cathode electrode in order to increase electron emission uniformity, a method of manufacturing the same, and an electron emission display device using the same.

In general, an electron emission element may be classified into a method using a hot cathode and a method using 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 field emission array (FEA) type electron emission device includes an electron emission portion and a driving electrode for controlling electron emission of the electron emission portion, and includes one cathode electrode and one gate electrode. Low or high aspect ratio materials, such as carbon-based materials or nanometer-sized materials, utilize the principle that electrons are easily released by an electric field in vacuum.

The electron emitting devices are arranged in an array on the first substrate to form an electron emitting device together with the first substrate, and the light emitting unit includes a fluorescent layer, an anode electrode, and the like on an opposite surface of the second substrate with the first substrate. To constitute a light emitting device together with the electron emitting device.

In the light emitting device, an unstable driving voltage may be applied to the driving electrodes or a voltage drop may occur due to an internal resistance of the driving electrodes. In this case, the emission characteristics of the electron emission parts become nonuniform, leading to a decrease in the uniformity of emission for each pixel.

In order to solve the above problem, an opening is formed inside the cathode electrode, an isolation electrode is disposed in the opening, a resistance layer is formed between the cathode electrode and the isolation electrode on both sides of the isolation electrode, and the electron emission portion is formed on the isolation electrode. The formed structure has been proposed. In this structure, the emission characteristics of the electron emitters become uniform as the electron emitter receives a stabilized current through the resistive layer.

However, in the cathode electrode structure described above, due to the arrangement of the isolation electrode and the resistive layer, the degree of integration of the electron emission parts is low, so that it is difficult to obtain a sufficient amount of electrons for each pixel, and the brightness of the screen is low.

In addition, in the above-described cathode electrode structure, the cathode electrode-isolation electrode and the resistive layer are typically formed by patterning the photolithography process, and an alignment error may occur between the cathode electrode-isolation electrode and the resistive layer during manufacturing. In this case, a poor contact may occur between the resistive layer and the cathode electrode or between the resistive layer and the isolation electrode to block a current flow toward the electron emission unit.

Accordingly, the present invention is to solve the above problems, the present invention is provided with a resistive layer on the cathode electrode to increase the degree of integration of the electron emitters to increase the electron emission amount per pixel, to prevent a poor contact between the electron emitter and the resistive layer. An electron emitting device, a method of manufacturing the same, and a light emitting device using the same are provided.

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

A substrate, a cathode electrode formed on the substrate, an electron emission part electrically connected to the cathode electrode, the cathode electrode extending along one direction of the substrate, a resistance layer connected to the main electrode with an opening, and a resistance layer disposed in the opening And a connection electrode connected to the connection electrode, wherein the electron emission part is positioned in the opening and connected to the connection electrode.

The connection electrode may extend along the length of the main electrode.

The openings may be formed in plural in the resistance layer, and the connection electrode may be formed to correspond to the openings individually.

The connection electrode may be made of metal and may include a plurality of strips arranged at any intervals therebetween.

The strips may be formed in a stripe pattern or a cross stripe pattern, and the width of the strip may be within 1 μm.

The connection electrode may be formed to have a width of 1 to 2 μm larger than that of the opening of the resistance layer.

The connection electrode may be made of a transparent material, Indium Tin Oxide (ITO).

The light emitting device may include a gate electrode and a focusing electrode formed on the cathode, and the cathode, the gate electrode, and the focusing electrode may be insulated from each other.

In addition, in order to achieve the above object, a light emitting device according to an embodiment of the present invention,

A cathode and a cathode disposed on one side of the fluorescent layer, the cathode and the other side of the substrate disposed opposite to each other, a cathode electrode formed on the substrate, an electron emission unit electrically connected to the cathode electrode, a fluorescent layer formed on one surface of the other substrate, and an anode located on one surface of the fluorescent layer. The electrode includes a main electrode extending along one direction of the substrate, a resistance layer having an opening and connected to the main electrode, and a connection electrode disposed in the opening and connected to the resistance layer, and the electron emission part is positioned in the opening and connected to the connection electrode.

In addition, in order to achieve the above object, a method of manufacturing an electron emitting device according to an embodiment of the present invention,

A conductive material is coated on the substrate to form a conductive layer, a mask layer having an arbitrary pattern is formed on the conductive layer, the conductive layer exposed by the mask layer is etched, and the mask layer is removed from the substrate to form a main electrode and a main electrode. Forming a connection electrode spaced apart from the electrode, forming a preliminary resistive layer by coating a resistive material on the substrate while covering the main electrode and the connective electrode, and forming an opening for exposing the connecting electrode to the preliminary resistive layer to form a resistive layer. And forming an electron emission portion connected to the connection electrode in the opening.

The forming of the connection electrode may include forming strips of a stripe pattern or a cross stripe pattern on the connection electrode.

The forming of the connection electrode may include forming a sacrificial layer on the front surface of the substrate, patterning the sacrificial layer to form an opening corresponding to the opening of the resistive layer on the sacrificial layer, and forming an electron emission part including a photosensitive material on the front surface of the substrate. And a step of coating the paste, selectively irradiating ultraviolet rays from the back surface of the substrate, selectively curing the electron emission forming paste, developing the electron emission forming paste, and removing the sacrificial layer.

The electron emission paste may include a carbon-based material or a nanometer-sized material.

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 and 2 are partially exploded perspective and partial cross-sectional views of a light emitting device according to an embodiment of the present invention, respectively. And FIG. 3 is a partial plan view of a cathode electrode of an electron emitting device according to an embodiment of the present invention.

Referring to FIG. 1, the light emitting device includes a first substrate 10 and a second substrate 12 that are disposed to face each other in parallel at predetermined intervals. Sealing members (not shown) are disposed at the edges of the first substrate 10 and the second substrate 12 to bond the two substrates, so that the first substrate 10 and the second substrate 12 are internal spaces. It will be configured a container having. This vessel is configured as a vacuum vessel by evacuating the inner space to a vacuum of approximately 10 ⁻⁶ Torr.

An electron emission unit 100 made of electron emission devices is provided on one surface of the first substrate 10 facing the second substrate, and one surface of the second substrate 12 facing the first substrate 10. It is provided with a light emitting unit 110 that receives electrons and emits visible light.

First, the electron emission unit 100 will be described. On the first substrate 10, the cathode electrodes 14, which are the first electrodes, are formed in a stripe pattern along one direction (the x-axis direction of the drawing) of the first substrate. The first insulating layer 16 is formed on the entirety of the first substrate 10 while covering the cathode electrodes 14. Gate electrodes 18 serving as second electrodes are formed on the first insulating layer 16 in a stripe pattern along a direction orthogonal to the cathode electrode 14 (y-axis direction in the drawing).

In the present exemplary embodiment, each of the cathode electrodes 14 may include a main electrode 141 formed in a stripe pattern on the substrate, a connecting electrode 142 and a main electrode 141 spaced apart from the main electrode 141 by a predetermined distance. ) And the connection electrode 142 to form a plurality of openings 143a over the connection electrode 142.

The electron emission part 20 is formed on the connection electrode 142 while filling the resistance layer opening 143a, and the openings corresponding to the electron emission parts 20 are formed in the insulating layer 16 and the gate electrodes 18. 161 and 181 are formed to expose the electron emission parts 20 toward the second substrate 12.

The connection electrode 142 is made of a metal material, for example, the same material as the main electrode 141, and may be formed to have the strip 142a for the back exposure process of the electron emission part 20. The connection electrode 142 may be formed to have a width of about 1 to 2 μm larger than the width of the electron emission part 20, and each of the strips may have a width d of 1 μm or less. In FIG. 3, since the width W1 of the opening 143a of the resistive layer 143 and the width of the electron emission part 20 are the same, the width of the opening W1 of the resistive layer 143 and the width of the connection electrode 142 ( W2) is shown in comparison.

1 and 3 illustrate that the strips 142a are formed in a cross stripe pattern to form openings 142b for passing ultraviolet rays between the strips 142a. The strips 142a may be variously modified into a stripe pattern in addition to the cross stripe pattern.

On the other hand, the connection electrode may be formed without a strip, in which case the connection electrode is made of a transparent conductive material, for example, indium tin oxide (ITO), for the back exposure of the electron emission unit 20.

The resistive layer 143 forms one or a plurality of openings 143a along the length direction of the cathode electrode 14 at the intersection with the gate electrode 18. The opening 143a of the resistive layer 143 is formed to have the same width as the electron emitting part 20 so that the sidewall of the resistive layer opening 143a is in contact with the sidewall of the electron emitting part 20.

The resistance layer opening 143a is formed such that its planar shape is included inside the planar shape of the connection electrode 142, so that the resistance layer 143 and the connection electrode 142 are energized with each other.

The electron emission unit 20 may be formed of materials emitting electrons, for example, carbon-based materials or nanometer-sized materials when an electric field is applied in a vacuum. The electron emission unit 20 may include at least one material selected from the group consisting of, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, fullerenes (C ₆₀ ), and silicon nanowires. .

1 and 3 illustrate the case in which the connection electrode 142 extends along the length direction of the main electrode 141, the connection electrode may be formed separately to correspond to the pixel area or the electron emission part 20. Can be.

Referring to FIG. 4, the connection electrode 142 is formed to correspond to each electron emitter 20 individually, and accordingly, a current may be independently supplied to each electron emitter 20, so that the electron emitters 20 may be provided. The electron emission uniformity of the can be improved.

Meanwhile, in FIGS. 1, 3, and 4, the openings 143a of the electron emission unit 20 and the resistive layer 143 are circular, and thus, the openings of the resistive layer 143 are formed along the longitudinal direction of the main electrode 141. Although the case in which the 143a is arranged in a line is illustrated, the planar phenomenon and the arrangement structure of the electron emission unit 20 and the resistive layer openings 143a are not limited to the illustrated example and can be variously modified.

The focusing electrode 22, which is a third electrode, may be formed on the gate electrodes 18 and the first insulating layer 16. A second insulating layer 24 is positioned below the focusing electrode 22 to insulate the gate electrode 18 and the focusing electrode 22, and also to pass the electron beam through the focusing electrode 22 and the second insulating layer 24. Openings 221 and 241 are provided.

The focusing electrode forms an opening corresponding to each of the electron emission parts 20 to individually collect electrons emitted from each electron emission part 20, or forms one opening for each pixel area to emit light from one pixel area. The electrons can be comprehensively focused. 1 shows the second case.

Next, the light emitting unit 110 will be described. On one surface of the second substrate 12, the fluorescent layer 26, for example, the red, green, and blue fluorescent layers 26R, 26G, and 26B may be disposed on each other. It is formed at arbitrary intervals, and a black layer 28 for improving contrast of the screen is formed between each fluorescent layer 26. The fluorescent layer 26 may be disposed such that one color of the fluorescent layers 26R, 26G, and 26B correspond to one pixel area.

An anode electrode 30 made of a metal film such as aluminum (Al) is formed on the fluorescent layer 26 and the black layer 28. The anode electrode 30 receives the high voltage required for electron beam acceleration from the outside of the vacuum container to maintain the fluorescent layer 26 in a high potential state, and toward the first substrate 10 of the visible light emitted from the fluorescent layer 26. The luminance of the screen is increased by reflecting the emitted visible light toward the second substrate 12.

The anode electrode may be formed of a transparent conductive film such as indium tin oxide (ITO). In this case, the anode is positioned on one surface of the fluorescent layer 26 and the black layer 28 facing the second substrate 12. Moreover, the structure which forms simultaneously the above-mentioned metal film and a transparent conductive film as an anode electrode is also possible.

In addition, spacers 32 (see FIG. 2) are disposed between the first substrate 10 and the second substrate 12 to counteract the compressive force applied to the vacuum container and to keep the distance between the two substrates constant. The spacers 32 are positioned corresponding to the black layer 28 so as not to invade the fluorescent layer 26.

The electron emission display device having the above-described configuration may be driven by supplying a predetermined voltage to the cathode electrodes 14, the gate electrodes 18, the focusing electrode 22, and the anode electrode 30 from the outside.

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

Then, an electric field is formed around the electron emission part 20 in the pixel areas in which the voltage difference between the cathode electrode 14 and the gate electrode 18 is greater than or equal to the threshold, and electrons are emitted therefrom. The emitted electrons are focused to the center of the electron beam bundle while passing through the opening 221 of the focusing electrode 22, and attracted by the high voltage applied to the anode electrode 30 to impinge on the fluorescent layer 26 of the corresponding pixel region. It emits light.

In the aforementioned driving process, the electron emission unit 20 receives a current required for electron emission from the main electrode 141 through the resistance layer 143 and the auxiliary electrode layer 142, and in this process, the resistance layer 143 The emission characteristic of the discharge parts 20 is made uniform.

On the other hand, the electron emission portion 20 formed by the screen printing method may undergo a shrinkage during the firing process. In this case, the electron emission part 20 partially contacts the resistance layer 143 or, in severe cases, does not come into contact with each other, thereby causing an emission failure.

Therefore, in the present embodiment, the connection electrode 142 is electrically connected to the resistive layer 143 and the electron emission part 20, thereby maintaining a constant value in the electron emission part 20 regardless of whether the electron emission part 20 is contracted or not. Current can be supplied to prevent bad emission.

Next, a method of manufacturing an electron emitting device according to an embodiment of the present invention will be described.

5A-5I are schematic diagrams at each manufacturing step shown to illustrate a method of manufacturing an electron emitting device according to an embodiment of the present invention.

Referring to FIG. 5A, a conductive material is coated on the substrate 10 to form a conductive layer 34, and a mask layer 36 having an arbitrary pattern is formed on the conductive layer 34.

Referring to FIG. 5B, a portion of the exposed conductive layer 34 that is not covered by the mask layer 36 is etched to form a stripe pattern main electrode 141 and a connection electrode 142 having a strip 142a. .

Next, referring to FIGS. 5C and 5D, a resistive material is coated on the main electrode 141 and the connection electrode 142 to form a preliminary resistive layer 243, and patterned to form the opening 143a at the electron emission forming position. The cathode layer 14 is completed by forming a resistive layer 143 having a. The opening 143a of the resistive layer 143 has the same size as the electron emission part to expose a part of the surface of the connection electrode 142.

Referring to FIG. 5E, an insulating material is coated on the entire substrate 10 to cover the cathode electrodes 14 to form a first insulating layer 16 having a predetermined thickness. Chemical vapor deposition (CVD) and screen printing may be used as the method of forming the first insulating layer 16. The conductive material is coated on the first insulating layer 16 and patterned to form a stripe-shaped gate electrode 18 that intersects with the cathode electrode 14.

Referring to FIG. 5F, the gate electrode 18 and the first insulating layer 16 are sequentially partially etched by a known photolithography process to form the gate electrode opening 181 and the insulating layer opening 161.

Subsequently, referring to FIG. 5G, the sacrificial layer 38 is formed over the entire substrate 10 and patterned to form an opening 381 having the same size as the resistive layer opening 143a at the resistive layer opening 143a. .

5H and 5I, the electron emission part 20 is formed by filling the electron emission part forming paste 40 in the resistive layer opening 143a. This process screen-prints the electron-emitting portion forming paste 40 including the photosensitive material on the sacrificial layer 38, and irradiates ultraviolet rays from the rear surface of the substrate 10 to fill the resistive layer opening 143a. Selectively curing the forming paste 40, removing the uncured electron emitting portion forming paste through development, peeling off the sacrificial layer 38, and then drying and firing the cured electron emitting portion forming paste. It may consist of steps.

At this time, in the step of irradiating the ultraviolet rays, the ultraviolet rays are sufficiently irradiated so that the electron emitting portion forming paste portion covered by the connection electrode 142 may be cured through scattering of ultraviolet rays.

The paste for forming an electron emission region is a material selected from the group consisting of carbon-based materials or nanometer-sized materials, such as carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, fullerenes, silicon nanowires, or mixtures thereof. It may include.

Since the electron emission part 20 is cured through backside exposure, the adhesive force to the substrate 10 and the connection electrode 142 is excellent, and the electron emission part 20 is electrically contacted with the resistance layer 143 and the connection electrode 142. Connected to the main electrode 141 to receive a current required for electron emission. That is, even when the electron emission part 20 is contracted and spaced apart from the resistive layer 143 in the firing step, the electron emission part 20 may receive a current through the connection electrode 142, thereby preventing emission failure.

The electron emission unit 20 may improve emission efficiency by exposing the electron emission materials to the surface through an activation process of attaching and detaching an adhesive tape (not shown) onto the substrate 10 as necessary.

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, the electron emission device according to the present invention forms a connection electrode to provide an additional conduction path to the resistive layer and the electron emission part. Thus, even if a shrinkage phenomenon occurs in the electron emission part in the firing process, the electron emission device emits an additional conduction path. Since the driving current can be supplied to the part, the emission failure can be prevented.

Therefore, the light emitting device according to the present invention has the effect of improving display quality, such as improved uniformity of light emission for each pixel, thereby increasing color purity and color reproducibility.

Claims (16)

Board; A cathode electrode formed on the substrate; And An electron emission unit electrically connected to the cathode electrode Including, The cathode electrode, A main electrode extending in one direction of the substrate; A resistance layer having an opening and connected to the main electrode; And A connection electrode disposed in the opening and connected to the resistance layer; Including, And an electron emission device connected to the connection electrode while the electron emission portion is positioned in the opening. The method of claim 1, And the connection electrode extends along the longitudinal direction of the main electrode. The method of claim 1, And a plurality of openings formed in the resistive layer, and the connection electrode is formed to correspond to the openings individually. The method of claim 1, And the connecting electrode is made of metal. The method of claim 4, wherein And a plurality of strips in which the connecting electrode is disposed at any interval. The method of claim 5, And the strips are formed in a stripe pattern or a cross stripe pattern. The method of claim 5, And an electron emitting device having a width of the strip within 1 μm. The method of claim 1, And the connection electrode is formed to a width of 1 to 2 탆 larger than an opening of the resistive layer. The method of claim 1, And the connection electrode is formed of a transparent material. The method of claim 9, And said connecting electrode is made of Indium Tin Oxide (ITO). The method of claim 1, And a gate electrode and a focusing electrode formed over said cathode electrode, wherein said cathode electrode, said gate electrode and said focusing electrode are insulated from each other. The electron emission device as described in any one of Claims 1-11, Another substrate disposed to face the substrate; A fluorescent layer formed on one surface of the other substrate; And An anode located on one surface of the fluorescent layer Light emitting device comprising a. Coating a conductive material on the substrate to form a conductive layer; Forming a mask layer having an arbitrary pattern on the conductive layer; Etching the conductive layer exposed by the mask layer; Removing the mask layer from the substrate to form a main electrode and a connection electrode spaced apart from the main electrode; Forming a preliminary resistive layer by coating a resistive material on the substrate while covering the main electrode and the connecting electrode; An opening is formed in the preliminary resistive layer to expose the connection electrode to form a resistive layer; And Forming an electron emission unit connected to the connection electrode in the opening; A method of manufacturing an electron emitting device comprising the steps. The method of claim 13, The connecting electrode forming step, Forming strips of the stripe pattern or the cross stripe pattern on the connection electrode. The method of claim 13, The connecting electrode forming step, A sacrificial layer is formed on the entire surface of the substrate, the sacrificial layer is patterned to form an opening corresponding to the opening of the resistive layer on the sacrificial layer, and an electron emission forming paste including a photosensitive material on the entire surface of the substrate. Process of applying, and irradiating ultraviolet rays from the back surface of the substrate to selectively cure the paste for forming the electron emitting portion, to develop the paste for forming the electron emitting portion, and to remove the sacrificial layer Method of manufacturing an electron emitting device comprising a. The method of claim 15, And the electron emitting paste comprises a carbonaceous material or a nanometer sized material.

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