KR100796975B1 - Field emission apparatus capable of controlling electron beam trajectory and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a field emission device and a method of manufacturing the same. The present invention forms a cathode on the substrate, the cathode electrode of which the installation area / width is determined in accordance with the divergence or focusing of the electron beam, forms an emitter electrically connected to the cathode, and an insulator layer bonded to the substrate. Prepare an insulator substrate having an opening corresponding to the emitter and a gate electrode provided on one side of the insulator layer, and a cathode substrate and an insulator substrate having a cathode electrode and an emitter installed so that the emitter is located at the center of the opening. It provides a method for producing a field emission device comprising the step of bonding. In addition, a cathode electrode patterned in a predetermined shape on the rear substrate, and a structure in which the width of the cathode electrode is expanded on the rear substrate, is provided with an auxiliary electrode, a cathode electrode, and an auxiliary electrode electrically insulated from the cathode electrode. Provided is a field emission device comprising a covering insulator layer, a gate electrode overlying the insulator layer, an emitter located in the opening of the insulator layer and connected to the cathode electrode, and an anode substrate provided with the anode electrode and the phosphor.

Field emission display, cathode substrate, anode substrate, insulator substrate, electron beam trajectory

Description

Field emission device capable of controlling electron beam trajectory and its manufacturing method {Field Emission Device with E-Beam Trajectory Control Structure and Manufacturing Method}

1A and 1B are a partial cross-sectional view and a perspective view of a field emission display according to the prior art.

2 is a partial cross-sectional view showing an aspect of a field emission device according to an embodiment of the present invention.

3 is a partial cross-sectional view showing another embodiment of the field emission device according to the embodiment of the present invention.

4A and 4B are diagrams showing a potential distribution and an electron beam trajectory simulation result according to the cathode electrode area of the present invention.

5 is a partial cross-sectional view of a field emission device according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: anode substrate 11: front substrate

12 phosphor 13 anode electrode

20: cathode substrate 21: back substrate

22a, 22b, 22c: cathode electrode 22d: auxiliary electrode

23 emitter 30 insulator substrate

31 insulator layer 32 gate electrode

33: opening 40: spacer

The present invention relates to a field emission device including a field emission display (FED) and a field emission light emitting device, and more particularly, to a field emission device having a cathode electrode structure capable of controlling the emitter trajectory.

The field emission display device is vacuum packaged so that the cathode substrate with the field emitter and the anode substrate with the phosphor are opposed to each other at an arbitrary distance, and the electrons emitted from the field emitter of the cathode substrate are transferred to the anode substrate. It is an apparatus that displays an image by cathodoluminescence of a phosphor by colliding with a phosphor. Field emission displays have been widely researched and developed as flat panel displays that can replace conventional cathode ray tubes (CRTs). In addition, the field emission display device can be used as a field emission light emitting device by emitting a front surface of the phosphor by simplifying its structure by omitting control of each pixel, and as a back light unit of a liquid crystal display (LCD), etc. It is being studied for use.

In general, it is important to minimize the spread of electrons emitted from an emitter in a field emission display device by minimizing the influence of electrons reaching a phosphor other than the phosphor corresponding to the corresponding sub-pixel. In the case of an emission light emitting device, it is important to prevent the electron beam emitted from the emitter from being concentrated in a specific area and to obtain even light emission characteristics over a large area.

FIG. 1A is a partial cross-sectional view of a field emission display according to the prior art, and FIG. 1B is a partial perspective view of the field emission display shown in FIG. 1A. An anode electrode 3 is formed on one surface of the front substrate 1 of the anode substrate, and a phosphor 2 is located on one surface of the anode electrode 3. On the rear substrate 9 of the cathode substrate opposite to the front substrate 1 of the anode substrate, an emitter 7 for field emission electrically connected to the cathode electrode 8 and the cathode electrode 8 is located. The gate insulator layer 6 and the gate electrode 5 are positioned on one surface of the back substrate 9 on which the cathode electrode 8 and the emitter 7 are installed, and each emitter 7 has no gate electrode 6. It is exposed to the phosphor 2 through the opening 6a of the insulator layer 6.

When a predetermined driving voltage is applied to the cathode electrode 8, the gate electrode 5, and the anode electrode 3 to emit electrons from the emitter 7, the electron beam emitted from the emitter 7 spreads radially. Done. As a result, some of the electron beams emitted from the emitter 7 reach the adjacent phosphors instead of the phosphors 2 corresponding to the corresponding pixels and emit light, thereby degrading the color reproducibility of the screen.

The above-described field emission apparatus according to the prior art generally forms a gate insulator layer 6 using a thin film process, so that its height is only within 10 mu m. As the electric field emitter 7 which is mainly used, the height of the insulator layer 6 is not so high as compared to CNT (Carbon Nano Tube) having a length of several micrometers, and the height is also low compared to the diameter of the opening 6a. In the case of the structure having such a low insulator layer 6, the electron beam emitted from the emitter 7 spreads a lot when it reaches the phosphor 2 of the anode substrate, and the color purity of the field emission display device is lowered. In addition, even in the field emission light emitting device having a favorable beam spreading characteristic, it is difficult to apply a high voltage to the anode electrode 3 due to the height of the insulator layer 6 lower than the diameter / width of the opening 6a. It becomes difficult to produce. On the other hand, when the diameter / width of the opening 6a is wider than the height of the insulator layer 6, the emitter 7 may be damaged due to the arc discharge which may be caused by the high voltage anode electrode 3, The electric field formed by the node voltage can affect the emitter 7 and make perfect operation difficult. In general, it is known that the luminous efficiency of the phosphor increases as the anode voltage increases. For these reasons, in the case of the field emission display, the emitter 7 and the opening 6a which are relatively smaller than the size of the phosphor 2 are formed to reduce the electron beam spread of the emitter 7, It is necessary to form additional electrodes for electron beam focusing on the gate electrode 5. In this case, the structure and manufacturing process of the device are complicated, which makes it difficult to apply.

The field emission light emitting device has a structure similar to that of the field emission display device, and differs in emitting white light from the entire emission area. In the case of the field emission light emitting device, in order to obtain uniform surface emission characteristics, it is necessary to spread the electron beam emitted from the emitter to reach the phosphor. As described above, in order to obtain high efficiency field emission property, It is required to apply the node voltage as high as possible.

SUMMARY OF THE INVENTION An object of the present invention is to easily manufacture a field emission display device having high color reproducibility or a field emission light emitting device having high light uniformity by controlling the spreading degree of an electron beam emitted from an emitter by controlling the area / width of a cathode electrode or an emitter. It is to provide a structure and a manufacturing method of the field emission device capable of.

Another object of the present invention is to control the spread of the electron beam emitted from the emitter by controlling the voltage of the auxiliary electrode provided around the cathode electrode to be used as a field emission display device having high color reproducibility or a field emission light emitting device having high uniformity of light emission. To provide a field emission device that can be.

According to an aspect of the present invention to achieve the above object, the method comprising the steps of: forming a cathode electrode on which the installation area is determined according to the divergence or selection of the electron beam; Forming an emitter electrically connected to the cathode electrode; Preparing an insulator substrate having an insulator layer bonded to the substrate, an insulator layer provided in the insulator layer, and an opening corresponding to the emitter, and a gate electrode provided on one surface of the insulator layer; And bonding the insulator substrate to the substrate provided with the cathode electrode and the emitter, wherein the forming of the cathode electrode includes the width of the cathode electrode when the focus of the electron beam is selected. A method of manufacturing a field emission device is provided, which includes forming a wider area and forming a width of the cathode electrode smaller than a width of the opening when selecting the divergence of the electron beam.

According to another aspect of the invention, forming a cathode electrode on a substrate; Forming an auxiliary electrode insulated from the cathode electrode on the same side of the substrate and adjacent to the cathode electrode; Forming an emitter connected to the cathode electrode; Preparing an insulator substrate having an insulator layer bonded to the substrate, an insulator layer provided in the insulator layer, the opening corresponding to the emitter, and a gate electrode provided on one surface of the insulator layer; And bonding an insulator substrate to a substrate equipped with a cathode electrode and an emitter.

According to another aspect of the invention, the cathode electrode located on the rear substrate and patterned in a predetermined form; An auxiliary electrode insulated from the cathode electrode on the same surface on which the cathode electrode is installed and installed adjacent to the cathode electrode; An insulator layer covering a back substrate having a cathode electrode and an auxiliary electrode; A gate electrode positioned over the insulator layer and having a gate hole; And an emitter located in the opening of the insulator layer corresponding to the gate hole and connected to the cathode electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are provided to fully understand the present invention for those skilled in the art.

2 and 3 are partial cross-sectional views showing two aspects of a field emission device according to an embodiment of the present invention.

2 and 3, the field emission device according to the present embodiment basically includes a cathode substrate 20 having a cathode electrode 22a or 22b and an emitter 23 or 23a disposed on one surface of the rear substrate 21. ), An insulator substrate 30 having a gate electrode 32 formed on the insulator layer 31 and bonded to the cathode substrate 20, and two substrates 20 and 30 having these bonded shapes. ) And an anode substrate 10 provided on one surface thereof with a phosphor 12 and an anode electrode 13 for applying a high voltage to the phosphor 12, and a cathode substrate 20 or an insulator substrate 30. And a spacer 40 supporting between the and the anode substrate 10. The thickness / height h of the insulator layer 31 is formed somewhat higher than the gate hole, i.e. the width or diameter r of the opening 33, and the emitter 23 is formed through the opening 33 to the anode substrate 10. Is provided so as to face each other with the phosphor 12 of

The field emission device shown in FIG. 2 is an example of application to a display device, and the width W1 of the cathode electrode 22a has a structure wider than the width r of the opening 33. The width is equal to or smaller than the width of the opening, and the field emission device shown in FIG. 3 is an example of application to a light emitting device. The width W2 of the cathode electrode 22b is smaller than the width r of the opening 33. In this case, the width of the emitter 23a has a structure smaller than the width of the opening as the width of the cathode electrode 22b decreases. According to such a configuration, by controlling the areas of the cathode electrodes 22a and 22b, it is possible to diverge or focus the electron beams emitted from the emitters 23 and 23a to control the area of the phosphor that is actually emitted. The above-described cathode electrode can be controlled to reduce the spread of the electron beam as the installation area is wider and to increase the spread as the narrower, but the area of the cathode electrode is the distance between neighboring emitters, the height of the insulator layer, the width of the opening or Since it is limited in relation to the width and the like, it is preferable to determine the structure.

The manufacturing process of the field emission device according to the present embodiment will be briefly described as follows. First, a cathode provided with a cathode electrode 22a or 22b on which one side of the rear substrate 21 is arranged, in which the electron beam is divergent or focused, and an emitter 23 or 23a electrically connected to the cathode electrode. The substrate 20 is prepared. The cathode substrate 20 may be provided with an electrode for controlling the electron beam emitted from the emitter and a device for controlling the voltage and current applied to the electrode. Then, an anode substrate 10 provided with a phosphor 12 and an anode electrode 13 for applying a high voltage to the phosphor 12 on one surface of the front substrate 11 is prepared. In addition, the insulator substrate 30 having a gate electrode 32 provided on one surface or an upper surface of the insulator 31 having at least one layer having a predetermined thickness and having an opening 33 corresponding to the emitter of the cathode substrate 20 is provided. Prepare.

Next, the cathode substrate 20 and the insulator substrate 30 are bonded. For example, the cathode substrate 20 and the insulator substrate 30 are brought into close contact with each other by the pressure of the spacer 40 in the vacuum packaging process. At this time, the emitters of the cathode substrate 20 are aligned to be located at the center of the opening of the insulator substrate 30. Next, a vacuum package is provided in which the spacer 40 is sandwiched between the cathode substrate 20 and / or the insulator substrate 30 and the anode substrate 10.

Referring to the operation of the above-described field emission device is as follows. First, when an appropriate voltage is applied to the cathode electrode 22a or 22b, the anode electrode 13 and the gate electrode 32, the electron beam emitted from the emitter 23 or 23a by the gate electrode 23 becomes an anode electrode. A portion of the phosphor 12 accelerated by (13) to reach the phosphor 12 on the front substrate 11 and the accelerated electrons collide emits light inherent to the phosphor, for example, red, green or blue. In this case, a voltage of 0 volts is generally applied to the cathode electrodes 22a or 22b, a positive voltage of several tens to hundreds of volts is applied to the gate electrode 32, and a positive voltage of several thousand to tens of thousands of volts is applied to the anode electrode 13. Here, the height of the gate insulator layer 31 is formed to correspond to or higher than the diameter or width of the opening 33 so that the electric field formed by the anode electrode 13 is formed on the emitter 23 formed on the cathode electrode 22a or 22b. Or to shield against impact on 23a).

In the field emission device of the present invention described with reference to FIG. 2, unlike the structure of the cathode electrode 8 of the conventional field emission device described with reference to FIG. 1, the area of the cathode electrode 22a is formed to be larger than that of the opening 33. The electrons emitted from the rotor 23 are operated to focus more than the electrons emitted from the conventional field emission device. This is because the electric field formed under the gate electrode 32 is adjusted to prevent the electron beam from spreading as the area of the cathode electrode 22a is widened. In addition, unlike the structure of the cathode electrode 8 of the conventional field emission device described with reference to FIG. 1, the field emission device of the present invention described with reference to FIG. 3 forms an area of the cathode electrode 22b smaller than the area of the opening 33. While the area of the emitter 23a is also made smaller than the area of the cathode electrode 22b, the electrons emitted from the emitter 23a can be induced to spread more than the electrons emitted from the conventional field emission device. . On the other hand, when the field emission device shown in Figs. 2 and 3 are used for different purposes, for example, as a field emission display device and a field emission light emitting device, the phosphor 12 of the anode substrate 10 is installed according to the use. It is possible to change the area to be wider or narrower.

4A and 4B are diagrams showing simulation results of a potential distribution and an electron beam trajectory according to a cathode electrode area.

4A and 4B are simulation results of the potential distribution and the electron beam trajectory formed between the cathode electrode and the gate electrode when the area of the cathode electrode is wide and narrow in the field emission device according to the embodiment of the present invention. Shows each. As shown in FIG. 4A, when the area of the cathode electrode is set wider than the area of the opening, the distorted potential lines around the cathode electrode are straightened so that the electron beam emitted from the emitter can be emitted directly toward the anode electrode. To help them do this.

On the other hand, as shown in FIG. 4B, when the area of the cathode electrode is set to be smaller than the area of the opening, the potential lines around the cathode are distorted in a curve so that the electron beam emitted from the emitter is emitted outward when passing through the space. have.

5 is a partial cross-sectional view of a field emission device according to another embodiment of the present invention.

Referring to FIG. 5, the field emission device according to the present embodiment has a structure in which the technique of controlling the spreading degree of the electron beam trajectory by changing the cathode area described above is applied. The field emission device is electrically connected to the cathode electrode 22c around the cathode electrode 22c. It is a main feature to install the auxiliary electrode 22d insulated with the above.

The auxiliary electrode 22d for controlling the electron beam emitted from the emitter 23 is formed around the cathode electrode 22c fixed at 0 volts, for example, by applying a voltage higher or lower than the voltage of the cathode electrode 22c. The electron beam trajectory may be divergent or focused. For example, by applying an appropriate positive voltage to the auxiliary electrode 22d, the curved potential lines shown around the cathode electrode of FIG. 4a are further bent to emit more electron beam trajectories, or by applying a negative voltage to the flat potential lines of FIG. 4b. It may be bent concave around the electrode 22c so that the electron beam can be focused.

In addition, the auxiliary electrode 22d may be formed at the same height or lower around the cathode electrode 22c. In the case of the field emission display device, the electron beam may be focused by applying a voltage lower than the cathode, for example, a negative voltage. In the case of the field emission light emitting device, a positive voltage may be applied to emit the electron beam.

On the other hand, the width of the cathode electrode compared to the diameter of the opening mentioned in the above embodiment may be represented by the length in the width direction perpendicular to the longitudinal direction of the cathode electrode when the cathode electrode is in the form of a stripe. In addition, in the above-described embodiment, the width of the cathode electrode is compared with the opening diameter. However, the present invention is not limited to such a configuration. When the emitter is installed on the entire bottom surface of the opening, the width of the cathode electrode is the diameter / width of the emitter. This can be explained in preparation.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

As described above, according to the present invention, the electron beam emitted from the emitter by setting the width of the cathode electrode of the field emission device to be wider or narrower than the opening diameter or by installing an auxiliary electrode around the cathode electrode and applying a desired voltage. It is possible to focus or divert the locus of, thereby making it possible to easily manufacture a field emission device that can be used in a field emission display device having high color reproducibility or a field emission light emitting device having high emission uniformity.

Claims (12)

Forming a cathode on the substrate, the cathode of which the installation area is determined according to the divergence or the focus of the electron beam; Forming an emitter electrically connected to the cathode electrode; Preparing an insulator substrate having an insulator layer bonded to the substrate, an insulator layer provided in the insulator layer, and an opening corresponding to the emitter, and a gate electrode provided on one surface of the insulator layer; And Bonding the insulator substrate to the substrate provided with the cathode electrode and the emitter, Forming the cathode electrode, Forming a width of the cathode electrode wider than the width of the opening when focusing the electron beam; and forming a width of the cathode electrode smaller than the width of the opening when diverging the electron beam. Manufacturing method. The method of claim 1, When the width of the cathode electrode is formed smaller than the width of the opening, And forming a smaller width of the emitter in correspondence with the smaller width of the cathode electrode. Forming a cathode electrode on the substrate; Forming an auxiliary electrode adjacent to the cathode electrode on the same surface on the substrate; Forming an emitter connected to said cathode electrode; Preparing an insulator substrate having an insulator layer bonded to the substrate, an insulator layer formed in the insulator layer, and an opening corresponding to the emitter and a gate electrode provided on one surface of the insulator layer; And Bonding the insulator substrate to the substrate provided with the cathode electrode and the emitter. delete 4. The electric field of claim 1 or 3, further comprising forming an anode electrode and a phosphor on another substrate opposed to the insulator substrate, and vacuum-bonding a spacer between the two opposite substrates. Method of manufacturing the release device. A cathode electrode disposed on the rear substrate and patterned in a predetermined shape; An auxiliary electrode insulated from the cathode electrode and disposed adjacent to the cathode electrode on the same surface on which the cathode electrode is installed; An insulator layer covering the back substrate provided with the cathode electrode and the auxiliary electrode; A gate electrode disposed on the insulator layer and having a gate hole; And And an emitter located in an opening of the insulator layer corresponding to the gate hole and connected to the cathode electrode. The field emission device of claim 6, wherein a height of the auxiliary electrode is equal to or less than a height of the cathode electrode. The field emission device of claim 6, wherein a lower voltage or a negative voltage is applied to the auxiliary electrode. The field emission device of claim 6, wherein a voltage higher than that of the cathode is applied to the auxiliary electrode. 10. The device of claim 6, wherein the width of the opening is less than or equal to the height of the insulator layer. 10. The field emission device of claim 6, wherein the emitter is comprised of a carbonaceous material or a nanometer sized material. The field emission device according to any one of claims 6 to 9, further comprising a front substrate disposed opposite the rear substrate, an anode electrode and a phosphor located on the front substrate.

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