KR100759376B1 - A method of making triode type field emission display device - Google Patents

Abstract

Forming a cathode on the first substrate to form a high aspect ratio, fine and uniform hole in the insulating layer when the field emission display device is manufactured; Applying a photosensitive material on the first substrate to cover the cathode electrode; Patterning the photosensitive material in a predetermined pattern to form a guide pillar for forming an insulating layer hole at a position where an electron emission layer is to be formed on the cathode electrode; Forming a preliminary insulating layer to cover the guide pillar over the first substrate; Removing an upper portion of the preliminary insulating layer to expose the upper end of the guide pillar to the outside; Removing the guide pillar from the cathode electrode to form an insulating layer for forming a hole in a portion where the guide pillar is located; Forming a gate electrode having a hole corresponding to the hole of the insulating layer on the insulating layer; Forming an electron emission layer on the cathode; Arranging a second substrate having an anode electrode and a fluorescent film substantially parallel with the first substrate and combining the second substrate to form a sealed container; And evacuating the inside of the closed container.

Field emission display device, carbon nanotube, 3-pole structure, column

Description

Manufacturing method of triode type field emission display device {A METHOD OF MAKING TRIODE TYPE FIELD EMISSION DISPLAY DEVICE}

1 to 10 are partially enlarged cross-sectional views illustrating a manufacturing process of a field emission display device according to a first embodiment of the present invention.

11 to 18 are partially enlarged cross-sectional views illustrating a manufacturing process of a field emission display device according to a second exemplary embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a triode type field emission display device, and more particularly, to a method of manufacturing a triode type field emission display device having a large aspect ratio, fine and uniform holes.

Early field emission display devices formed a conical metal tip on the cathode electrode, and formed a gate electrode around the metal tip to emit electrons from the metal tip, thereby converting the emitted electrons into a fluorescent film attached to the anode electrode. It was formed into a structure that accelerates and implements an image.

However, since the structure of the field emission display device requires the use of expensive semiconductor equipment to form the metal tip, that is, the electron emission layer, the manufacturing cost increases, and it is difficult to implement a large area display due to a complicated manufacturing process. In order to solve the above problems, a field emission display device having the electron emission layer as a plane has been proposed. At this time, the plane electron emission layer is usually made of a carbon-based material, and in recent years, carbon nanotubes (CNTs) have been proposed. : Carbon NanoTube) is in the spotlight. It is known that the carbon nanotubes have a fine radius of curvature of about 100 kPa and their electron emission is smooth even at an external voltage of about 10 to 50 V. Accordingly, carbon nanotubes are expected to be an ideal electron emission source for field emission displays that can be easily driven with low voltage and have a large area.

In general, a field emission display device having carbon nanotubes as an electron emission source is manufactured in a triode structure having a gate electrode to easily control electron emission. In this case, the carbon nanotube electron emission layer In general, the insulating layer and the gate electrode are stacked on the cathode electrode, and then a hole is formed on the insulating layer and the gate electrode to expose the cathode to the outside, and then is formed in the hole and disposed on the cathode electrode. .

In the above process, the insulating layer having the hole may be formed by a thin film process such as plasma enhanced chemical vapor deposition (PECVD) or a thick film process by printing paste.

However, conventionally, there is a problem for each process, whether it is a thin film process or a thick film process with respect to the insulating layer, which is preventing the production of a good tripolar type field emission display device. That is, when forming the insulating layer using a thin film process, it is possible to form a film having excellent insulating properties, but there is a problem that it is difficult to form the film thickness as thick as necessary. Here, the required thickness of the insulating layer means a thickness thicker than the thickness of the electron emitting layer.

In addition, even if the insulating layer is formed to the required thickness by using the thin film process, the process time is long and the stress in the film must be controlled, and in order to make the thick film uniform during hole formation, only a complicated etching process is used. There is a problem.

On the other hand, in the case of forming the insulating layer by using a thick film printing method, it is easy to form a thick film to a desired thickness. However, in view of the characteristics of the printing method, it is difficult to form the above-mentioned holes uniformly and finely. Here, in the process of forming a hole in the insulating layer through a printing method, the insulating layer may have a hole only by the printing method itself, and once the insulating layer is printed and fired, the hole may be formed through an etching process. Although it is possible to achieve both, conventionally, the process of forming an insulation layer of the field emission display device using both printing methods has an inadequate aspect in that the insulation layer has a hole having a small size while having a desired thickness.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to form an insulating layer disposed between a cathode electrode and a gate electrode at a desired thickness, while forming a fine and uniform hole therein, when the field emission display device is manufactured. The present invention provides a method for manufacturing a field emission display device.

The present invention to achieve the above object,

A cathode electrode is formed on the first substrate, a photosensitive material is coated on the first substrate to cover the cathode electrode, and the photosensitive material is patterned in a predetermined pattern to form an electron emission layer on the cathode electrode. Forming a guide pillar for forming an insulating layer hole in the substrate, forming a preliminary insulating layer to cover the guide pillar over the first substrate, and removing an upper portion of the preliminary insulating layer to expose the upper end of the guide pillar to the outside. And removing the guide pillar from the cathode electrode to form an insulating layer for forming a hole in a portion where the guide pillar is located, and forming a gate electrode having a hole corresponding to the hole of the insulating layer on the insulating layer. And forming an electron emission layer on the cathode, and forming a second substrate on which an anode electrode and a fluorescent film are formed. Provided is a method of manufacturing a tripolar tube type field emission display device which is disposed substantially in parallel with a plate and is combined to form a sealed container and is exhausted from the sealed container.

In the above-described manufacturing method, the guide pillar for forming the insulating layer hole is formed in the photosensitive material by forming a hole having a predetermined pattern by a photolithography process, and plating the inside of the hole by a plating method to form a plating layer in the hole. Thereafter, the photosensitive material is removed from the first substrate to form a metal pillar by the plating layer. Herein, the method of forming the metal pillar may be performed by both an electrolytic plating method and an electroless plating method, and the method of removing the metal pillars may be achieved by a chemical etching method or an electrolysis method.

In the manufacturing method, the insulating layer hole forming guide pillar may be formed by patterning the photosensitive material in a photolithography process so that a pattern made of the photosensitive material remains at a position where the electron emission layer is to be formed. Can be. At this time, the exposure process of the photolithography process used for forming the pattern corresponding to the said guide pillar is a so-called front surface exposure method performed from the side of the 1st board | substrate with which the said cathode electrode was formed, or the 1st in which the said cathode electrode is not formed. Both the so-called backside exposure system performed from the back surface side of a board | substrate is possible, and a backside exposure system is especially preferable.

In addition, in the present invention, the photosensitive material may be selected from any one of a dry film resist (DFR) film, a polyimide, an emulsion, or a photoresist.

In the present invention, the preliminary insulating layer is formed by coating, drying, and firing the insulating paste on the first substrate so that the guide pillar for forming the insulating layer holes is covered by a printing method. It is formed as a printing method.

Accordingly, in the present invention as described above, in forming the field emission display device, before forming the insulating layer, a guide pillar corresponding to the hole of the insulating layer is formed in advance on the cathode electrode where the electron emitting layer is to be disposed, By finally forming the holes of the insulating layer by using the guide pillars, it is possible to form a triode type field emission display device having a finer, higher aspect ratio insulating layer hole.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 to 8 are schematic views for explaining the manufacturing process of the tripolar tube type field emission device according to the first embodiment of the present invention, the manufacturing of the tripolar type field emission device according to Example 1 of the present invention with reference to these drawings. Explain the process.

First, as shown in FIG. 1, a cathode electrode 4 on a line is formed on a first substrate (or lower substrate, hereinafter referred to as lower substrate for convenience) 2 that forms a vacuum container which is an external appearance of a field emission display device. To form a plurality. The cathode electrode 4 is generally formed of a metal such as chromium, silver, nickel, or the like, and in some cases, is also formed of indium tin oxide (ITO), which is a transparent material. The thickness of the cathode electrode 4 is preferably maintained at 1000 to 3000 kPa. For reference, FIG. 1 is a cross-sectional view taken along an axis parallel to the length direction of the cathode electrode 4. As the method of forming the cathode electrode 4, a thin film forming method such as sputtering or a thick film forming method such as printing may be selectively used depending on the material of the cathode electrode 4.

After the cathode electrode 4 is formed, as shown in FIG. 2, the photosensitive material 6 is coated on the lower substrate 2 so that the cathode electrode 4 is covered and patterned in a predetermined pattern. there is the turning, the photosensitive substance (6), DFR (Dry film resist) film, polyimide (polyimide), emulsion, or said lead may be provided with a photoresist or the like, the present embodiment clerical script is a film form of a DFR film It is applied.

In the present invention, the photosensitive material 6 is disposed on the cathode electrode 4 and patterned before the insulating layer is formed on the cathode electrode, such as in a manufacturing process of a general field emission display device. In order to form a guide pillar for forming an insulating layer hole on the cathode electrode 4, that is, the position where the electron emission layer is to be formed.

In the present embodiment, the guide pillar is formed through the following steps. First, as shown in FIG. 2, the photosensitive material 6 is exposed and developed by photolithography in a state where the photosensitive material 6 is disposed on the lower substrate 2 with a predetermined thickness. A hole 6a having a predetermined pattern is formed on the photosensitive material 6 (see FIG. 3).

Next, a plating layer 7 'is formed in the hole 6a using a plating method such as an electrolytic plating method or an electroless plating method (see FIG. 4). When the plating layer 7' is formed, the plating layer 7 'is formed. The photosensitive material 6 on the lower substrate 2 is removed from the lower substrate 2 so that the plating layer 7 'is exposed to the outside, thereby forming the guide pillar 7 (see FIG. 5). That is, in this embodiment, the guide pillar 7 is made of a metal pillar formed by plating.

Subsequently, a preliminary insulating layer 8 having a thickness sufficient to cover the guide pillar 7 over the lower substrate 2 is formed. In this embodiment, the preliminary insulating layer 8 is a printing method. Is formed. That is, an insulating paste is printed on the lower substrate 2 so that the guide pillar 7 is covered, and the printed insulating paste is dried in a temperature atmosphere of 90 to 120 ° C. to provide the preliminary insulating layer 8. (See Figure 6).

After the preliminary insulating layer 8 is formed, the upper portion of the preliminary insulating layer 8 is removed by polishing, sand blasting, or etching to expose the upper end of the guide pillar 7 to the outside. do. (See FIG. 7) Here, the thickness t of the preliminary insulating layer 8 remaining after removing the upper portion thereof is preferably equal to the height h of the guide pillar 7. It is also possible to have a size. Thereafter, it is further baked in a 400 to 550 ° C. temperature atmosphere to complete the formation of an insulating layer having the film quality required by the device.

Subsequently, a process of removing the guide pillar 7 by a removal liquid or electrolysis method for the plating layer 7 ′ is performed. When the guide pillar 7 is removed from the lower substrate 2, the preliminary A plurality of holes 10a are formed on the insulating layer 8, whereby the preliminary insulating layer 8 is formed of a true insulating layer 10 (see FIG. 8).

After the insulating layer 10 is manufactured through the manufacturing steps as described above, a gate electrode 12 is formed on the insulating layer 10 in the same manner as when the cathode electrode 4 is formed. A paste for the electron emission layer is printed into the hole 10a of the insulating layer 10 by a printing method to form an electron emission layer 14 having an arbitrary pattern on the cathode electrode 4. The paste is provided as a paste containing a carbon-based material such as carbon nanotubes, graphite, diamond, diamond phase carbon and the like.

When the electron emission layer 14 is formed and formed as shown in FIG. 9 through a printing method, a transparent second substrate (or a front substrate or less, or a front surface for convenience) is formed in a separate process from the rear substrate 2. An anode electrode 18 and a fluorescent film 20 are formed on the substrate 16, and the rear substrate (side glass 22 is disposed between the front substrate 16 and the rear substrate 2). 2) and the front substrate 16 in parallel, and then joining the rear substrate 2, the front substrate 14 and the side glass 22 through the seal member 24, thereby displaying the field emission display. To form one sealed container.

Finally, the inside of the sealed container is exhausted by an exhaust device (not shown), thereby completing a tripolar field type display device. (See FIG. 10)

Therefore, when the tripolar tube type field emission display device is formed through the above-described manufacturing steps, the process steps are simple, not through the etching method that is not only complicated but also difficult to control the shape of the hole, or the thick film printing method that is difficult to control the hole pattern. And a guide pillar corresponding to the hole shape through the plating method which is easy to control the pattern, and by using this, it is possible to easily form the holes of the insulating layer having fine and good aspect ratio, thereby improving the quality of the corresponding field emission display device. It becomes possible.

Next, another embodiment of the present invention will be described. 11 to 16 are schematic views for explaining a manufacturing process of the triode type field emission device according to the second embodiment of the present invention, with reference to these drawings of the triode type field emission device according to the second embodiment of the present invention. Describe the manufacturing process. In the second embodiment, the manufacturing steps of the above-described guide layer for forming the insulating layer hole are greatly different in view of the first embodiment. As shown in FIG. 11, the vacuum container of the field emission display device is first used. A plurality of cathode electrodes 32 on a line are formed on the first substrate (or lower substrate, hereinafter referred to as lower substrate for convenience) 30 to be formed. In this second embodiment, the cathode electrode 32 includes ITO 32a and chromium 32b that are sequentially stacked on the lower substrate 30 and patterned in a predetermined pattern. (See Figure 11)

Next, in order to form the guide pillar, a photosensitive material 34 is coated on the lower substrate 30 so as to cover the cathode electrode 32 as in the first embodiment. The photosensitive material 34 is preferably the same as those listed in the description of the first embodiment, and this second embodiment also uses a DFR film. The coating thickness of the photosensitive material 34 is then equal to or greater than the thickness of the insulating layer 40 (see FIG. 16) formed on the back substrate 30. (See Figure 12)

In this state, the photosensitive material 34 is patterned to form the guide pillar. In the second embodiment, the photosensitive material 34 is photolithographically treated to provide the guide as described above. Make a pillar. That is, the photosensitive material 34 is exposed and developed so that a predetermined pattern is formed on the photosensitive material 34. In this case, the exposure process of the photosensitive material 34 may include the lower substrate 30. As a reference, a predetermined light source may be irradiated to the photosensitive material 34 from a surface side of the lower substrate 30 on which the cathode electrode 32 is formed, or the cathode electrode 32 may be The photosensitive material 34 may be irradiated with a light source from the rear surface side of the lower substrate 30 which is not formed. In this embodiment, the above exposure step is performed by the above-described backside exposure method as shown in FIG. In this backside exposure process, the chromium 32b pattern of the cathode electrode 32 serves as a mask for patterning the photosensitive material 34.

After the exposure process is completed and the development process is performed, an insulating layer hole due to the photosensitive material 34 is formed between the chromium 32b and the chromium 32b of the cathode electrode 32, that is, the region where the electron emission layer is formed. The forming guide pillar 36 is formed to have a predetermined height and width (see FIG. 13).

Subsequently, as in the first embodiment, the preliminary insulating layer 38 is formed on the lower substrate 30 (see FIG. 14), and the preliminary insulating layer 38 is exposed to expose the top surface of the guide pillar 36. By removing the upper portion of () (see FIG. 15), and removing the guide pillar 36 from the lower substrate 30, the insulating layer 40 having a hole 40a in which the electron emission layer is to be finally obtained Form. (See Figure 16)

Since the processes of forming the preliminary insulating layer, removing the upper portion of the preliminary insulating layer, and removing the guide pillar are performed in the same manner as in the first embodiment, the detailed description thereof will be replaced with the above description. However, in the second embodiment, since the guide pillar is made of the photosensitive material, the removal liquid used for the removal of the guide pillar may be used corresponding to the photosensitive material.

After the insulating layer 40 is formed, the gate electrode 42 is formed on the insulating layer 40 as usual in the next step (see FIG. 17), and the hole 40a of the insulating layer 40 is formed. An electron emission layer 44 is formed on the cathode electrode 32 (see FIG. 18), and then the anode electrode 48 and the fluorescent film (on the second substrate (or front substrate) 46), which are separate substrates, are formed. 50 is formed, and then a sealed container is formed by interposing a side glass 52 between the lower substrate 30 and the front substrate 46 and sealing them with a sealing material 54. Such a sealed container is exhausted to complete a field emission display.

Since the above process steps are made in the same manner as in the first embodiment, the detailed description will be replaced by the above description.

In the above, preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the scope of the accompanying drawings. Naturally, this also belongs to the scope of the present invention.

According to the present invention, a guide pillar is formed of a photosensitive material or a plating layer, and the hole of the insulating layer is formed using the guide pillar, thereby forming a hole having a large aspect ratio, fine and uniform without using a complicated etching process.

Furthermore, the field emission display device according to the present invention has a large aspect ratio and has holes of a fine and uniform insulating layer, so that when electrons are focused from the electron emission layer to the fluorescent film through the holes, the field emission display device is provided between the gate electrode and the fluorescent film. By reducing the amount of leakage and focusing in a better state, the result is a high quality image with high contrast and clear color separation.

Claims (8)

Forming a cathode electrode over the first substrate; Applying a photosensitive material on the first substrate to cover the cathode electrode; Patterning the photosensitive material in a predetermined pattern to form a guide pillar for forming an insulating layer hole at a position where an electron emission layer is to be formed on the cathode electrode; Forming a preliminary insulating layer to cover the guide pillar over the first substrate; Removing an upper portion of the preliminary insulating layer to expose the upper end of the guide pillar to the outside; Removing the guide pillar from the cathode electrode to form an insulating layer for forming a hole in a portion where the guide pillar is located; Forming a gate electrode having a hole corresponding to the hole of the insulating layer on the insulating layer; Forming an electron emission layer on the cathode; Arranging a second substrate on which an anode electrode and a fluorescent film are formed to be substantially parallel to the first substrate and combining the second substrate to form a sealed container; And And exhausting the inside of the hermetically sealed container. The method of claim 1, The photosensitive material is a method of manufacturing a tripolar field emission display device, wherein the photosensitive material is selected from any one of a DFR (Dry Film Resist) film, polyimide, emulsion, or photoresist. The method of claim 1, Guide pillar for forming the insulating layer hole, Forming a hole having a predetermined pattern in the photosensitive material by a photolithography process, And plating the inside of the hole by a plating method to form a plating layer in the hole, and then removing the photosensitive material from the first substrate to form a metal pillar by the plating layer. The method of claim 3, wherein The forming of the preliminary insulating layer is a method of manufacturing a tripolar field emission display device by applying and drying an insulating paste on the first substrate so that the guide pillar for forming the insulating layer hole is covered by a printing method. The method of claim 3, wherein And removing the metal pillars by chemical etching or electrolysis. The method of claim 1, Guide pillar for forming the insulating layer hole, And patterning the photosensitive material so that a pattern made of the photosensitive material remains at a position where the electron emission layer is to be formed by a photolithography process. The method of claim 6, A method of manufacturing a tripolar tube type field emission display device, wherein the exposure by the photolithography step is performed from the rear surface of the first substrate on which the cathode electrode is not formed. A triode type field emission display according to any one of claims 1 to 7.

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