KR20060060477A - Image display device with anode pad and method for manufacturing the anode pad - Google Patents

Abstract

The present invention relates to an image display apparatus which maintains an area where an electron emitting portion and a fluorescent layer are located at even intervals without embedding a spacer, and improves an anode pad portion. The image display apparatus according to the present invention provides an electron emitting portion. A first substrate, a second substrate disposed in front of the first substrate to form a first region together with the first substrate, and a second substrate disposed behind the first substrate and in communication with the first region together with the first substrate. And a vacuum structure having a reinforcing member forming a second region. At this time, the second substrate forms a metal anode electrode on one surface thereof and an anode pad portion of metal contacting the anode electrode, and forms an uneven surface having a surface roughness of 0.2 to 2 μm on a contact portion with the anode pad portion.

Vacuum structure, anode electrode, fluorescent screen, black layer, anode pad part, electron emitting part, reinforcing member, reinforcing board

Description

IMAGE DISPLAY DEVICE WITH ANODE PAD AND METHOD FOR MANUFACTURING THE ANODE PAD

1 is a cross-sectional view of an image display device according to an embodiment of the present invention.

FIG. 2 is a bottom view of the second substrate shown in FIG. 1.

3 is a perspective view of the image display device illustrated in FIG. 1 as viewed from the rear.

4 is a sectional view of an image display device showing another embodiment of the reinforcing member.

5 is a sectional view of an image display device showing another embodiment of a vacuum structure.

6 is a partial perspective view of the reinforcing substrate shown in FIG. 5.

7A and 7B are schematic views at each step shown to explain a method for manufacturing an anode pad part according to the present invention.

8 is a partially exploded perspective view showing a case where the image display device according to the present invention is applied to a field emission display device.

9 is a partial sectional view showing a case where the image display device according to the present invention is applied to a field emission display device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly, to an image display device in which an area in which an electron emitting portion and a fluorescent layer are located at uniform intervals and an anode pad portion are improved without embedding a spacer.

An image display apparatus using electrons for emitting a fluorescent layer typically has a basic structure of a vacuum structure having an electron emitting portion and a fluorescent layer therein, and excites a fluorescent layer with electrons emitted from the electron emitting portion to display a predetermined display. It works.

Such image display apparatuses can be classified into a method using a hot cathode and a method using a cold cathode according to the type of electron source. In addition, depending on the shape of the vacuum structure, a bulb-type structure such as a cathode ray tube is used, and an inner space is formed after the front substrate and the rear substrate are bonded at random intervals, such as a fluorescent display tube and a field emission display device. It can be classified in a manner using an exhausted plate-like structure.

In the image display apparatus using the flat panel structure as described above, as the screen size increases and the internal vacuum degree increases, the compressive force applied to the vacuum structure increases. Therefore, in the conventional image display apparatus, a large number of spacers are provided inside the vacuum structure to prevent deformation or breakage of the vacuum structure due to the compressive force while maintaining the front substrate and the rear substrate at regular intervals.

However, in recent years, as the image display device becomes higher resolution, the width of the non-light emitting area in which the spacer is to be located becomes narrower. Accordingly, a spacer having a fine size and a high aspect ratio is required. However, spacers satisfying this condition are not easy to manufacture, and there are many difficulties in the process when attaching thousands of micro spacers onto the front substrate or the rear substrate.

In addition, the conventional image display apparatus may not increase the initial vacuum degree due to the spacers in the process of exhausting the inside of the structure through the exhaust pipe, and a bad mounting of the spacer may occur in the exhaust process. If the image display device does not initially secure high vacuum, the degree of vacuum is gradually lowered due to outgassing of members provided inside the vacuum structure, thereby degrading device characteristics. In addition, spacers in which mounting failure occurs may damage the fluorescent layer or block the electron beam path, thereby degrading the screen quality.

Moreover, the gap between the front substrate and the rear substrate, which is determined by the height of the spacer, has a certain limit in increasing its size due to the manufacturing limitations of the spacer. In the case of the field emission display device, this causes display defects such as electrons being emitted under the influence of the anode electric field in the electron emission portion of the pixel to be turned off. In general, the anode voltage and the screen brightness have a proportional relationship, and for the aforementioned reasons, the conventional field emission display has difficulty in implementing high brightness.

On the other hand, the image display device includes an anode pad portion formed over the inside and outside of the vacuum structure to apply a voltage to the anode electrode. Usually, the anode pad portion is formed at the same time as forming the black layer of the fluorescent screen, and the black layer and the anode pad portion are mainly composed of chromium oxide film.

In the conventional image display apparatus, the black layer and the anode pad portion are mainly divided into 1) an indium tin oxide (ITO) film serving as an anode electrode, into a display area and a pad area, ② sputtering chromium on the ITO film, and ③ a dry film resist on the chromium layer. Apply dry, ④ pattern the dry film resist through exposure and development, ⑤ selectively remove the chromium layer through etching, form the black layer and the anode pad pattern, ⑥ peel off the dry film resist, ⑦ heat treatment process It is completed by forming a chromium oxide film through the reaction of ITO and chromium. However, the anode pad portion thus completed has a disadvantage in that manufacturing is complicated and the process efficiency is lowered.

As described above, the spacer is an effective member for securing the stability of the flat plate vacuum structure, but is a major cause of lowering the productivity of the image display device, and serves as a detrimental factor in improving the screen quality.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to form a stable vacuum structure without embedding a spacer, and to provide an image display apparatus which can simplify the manufacturing process of the anode pad portion and reduce the manufacturing cost. It is.

An image display device of the present invention for achieving the above object comprises a first substrate provided with an electron emitting portion, a second substrate disposed in front of the first substrate to form a first region together with the first substrate, And a vacuum structure having a reinforcing member disposed behind the first substrate, the reinforcing member defining a second region in communication with the first region together with the first substrate. At this time, the second substrate forms a metal anode electrode on one surface thereof and an anode pad portion of metal contacting the anode electrode, and forms an uneven surface having a surface roughness of 0.2 to 2 μm on a contact portion with the anode pad portion.

In addition, the image display device of the present invention for achieving the above object, the first substrate provided with the electron emitting portion, and having a larger thickness than the first substrate and disposed in front of the first substrate and the metal anode electrode and the anode A second substrate provided with an anode pad portion of metal in contact with the electrode, and a reinforcement substrate having a thickness greater than that of the first substrate and attached to a rear surface of the first substrate and forming a vacuum structure together with the first substrate and the second substrate; do. At this time, the second substrate forms a concave-convex surface having a surface roughness of 0.2 to 2 μm at a contact portion with the anode pad portion.

In addition, the present invention, in order to achieve the above object,

Disposing a mask having an opening corresponding to the shape of the anode pad portion on the second substrate, and surface treating the second substrate portion exposed by the opening to form an uneven surface having a surface roughness of 0.2 to 2 μm; And forming an anode pad portion by sputtering a metal on an uneven surface.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of an image display device according to an exemplary embodiment of the present invention, FIG. 2 is a bottom view of the second substrate shown in FIG. 1, and FIG. 3 is a perspective view of the image display device shown in FIG. .                     

1 to 3, the image display device includes a first substrate 2 and a second substrate 4 disposed opposite to each other with the first region 100 interposed therebetween, and a rear side of the first substrate 2. And a vacuum structure (8) consisting of a reinforcing member (6) attached to and forming a second region (200) together with the first substrate (2).

The first region 100 and the second region 200 mean a space divided by the first substrate 2 in the vacuum structure 8, and the first substrate 2 in the vacuum structure 8. The through hole 2a is formed in the first region 100 and the second region 200 to communicate with each other.

More specifically, the first substrate 2 is provided with a configuration for electron emission, that is, electron emission means 10. The second substrate 4 is provided with a configuration, that is, a fluorescent screen 12, which emits visible light by electrons to perform any light emission or display.

The first substrate 2 and the second substrate 4 may be integrally bonded while the sidewalls 14 having a rectangular frame shape are positioned at edge portions between the two substrates. As a result, a first region 100 surrounded by the first substrate 2, the second substrate 4, and the sidewall 14 is formed, and the first substrate 2 and the second substrate (according to the height of the sidewall 14) are formed. The interval of 4) is determined.

The side wall 14 may be attached to the first substrate 2 and the second substrate 4 by frit, which is low melting point glass, and the reference numeral 16 in the drawing denotes the side wall 14 and the first substrate 2. And a first frit layer bonded to the second substrate 4.

Here, the second substrate 4 is preferably formed to a sufficient thickness to withstand the vacuum compression force, for example, a thickness of 10 mm or more. On the other hand, the first substrate 2 is preferably formed to a thickness smaller than the second substrate 4, for example, 5 mm or less.                     

Since the first substrate 2 is a substrate provided with driving electrodes for emitting electrons from the electron emitting portion together with the electron emitting portion, a process of forming an insulating layer for insulating between the electron emitting portion, the driving electrodes, and the driving electrodes is performed. Is subjected to several high temperature heat treatment processes. Accordingly, the thickness of the first substrate 2 is preferably 5 mm or less in order to reduce thermal stress of the first substrate 2 due to temperature change, thereby preventing cracking of the first substrate 2, and to increase film formation characteristics.

The reinforcing member 6 forming the outline of the vacuum structure 8 is attached to the back of the first substrate 2 in place of the first substrate 2, and is surrounded by the first substrate 2 and the reinforcing member 6. The second region 200 is formed. The second region 200 is formed to have a volume larger than that of the first region 100, preferably two times or more. The reinforcing member 6 may be attached to the first substrate 2 by frit, in which the reference numeral 18 denotes a second frit layer joining the first substrate 2 and the reinforcing member 6.

It is preferable that the minimum thickness of the reinforcing member 6 is greater than the thickness of the first substrate 2 in consideration of the strength characteristic. The reinforcing member 6 may be provided with an exhaust pipe 20 used to exhaust the inside of the structure, and a getter 22 for adsorbing and removing residual gas after the exhaust.

As described above, the vacuum structure 8 forms the second region 200 communicating with the first region 100 behind the first substrate 2 by the reinforcing member 6, thereby expanding the internal volume. The gap between the first substrate 2 and the second substrate 4 can be kept constant without having a spacer in the region 100, and a stable structure can be ensured.                     

And the vacuum structure 8 of the present embodiment can increase the internal volume to increase the initial vacuum degree to approximately 10 ^-6 Torr or more. If the initial vacuum degree is increased, even if the gas is released from the materials constituting the electron emitting means 10 or the fluorescent screen 12 when the product is used, the high initial vacuum degree compensates for this even if the vacuum degree is lowered, thereby preventing deterioration of the vacuum degree and consequent deterioration of device characteristics. Can be.

In the present embodiment, the fluorescent screen 12 includes a fluorescent layer, for example, red, green, and blue fluorescent layers 24R, 24G, 24B positioned at arbitrary distances from each other, and each of the fluorescent layers 24R, 24G, A black layer 26 positioned between 24B to increase the contrast of the screen, and an anode electrode 28 of a metal (for example, aluminum) formed on the fluorescent layers 24R, 24G and 24B and the black layer 26. Is done. An anode pad portion 30 is formed on the second substrate 4 over the inside and outside of the vacuum structure 8, and a part thereof contacts the anode electrode 28.

The anode electrode 28 is made of a metal film by deposition, not a transparent electrode layer such as ITO. The anode electrode 28 reflects the visible light emitted from the fluorescent layers 24R, 24G, and 24B toward the anode electrode 28 toward the second substrate 4 to increase the brightness of the screen, and the patterning process as in the conventional ITO film. This is not required so that the manufacturing process of the fluorescent screen 12 can be simplified.

Since the anode pad part 30 is in contact with an external circuit device (not shown) and receives an anode voltage therefrom, excellent robustness is required. To this end, an uneven surface 4a having a surface roughness of 0.2 to 2 μm is formed at a portion of the second substrate 4 that contacts the anode pad portion 30, and the anode pad portion 30 is formed on the uneven surface 4a. Is formed.

The anode pad part 30 is made of metal such as chromium (Cr), nickel (Ni), copper (Cu), silver (Ag), or aluminum (Al), and the second substrate 4 is formed by the uneven surface 4a. The adhesion to) is increased, thereby improving the conductive properties and the adhesion life.

At this time, if the portion of the second substrate 4 in contact with the anode pad portion 30 has a surface roughness of less than 0.2 μm, the anode pad portion 30 is easily dropped in a subsequent cleaning section, and the anode pad portion 30 is separated from the anode pad portion 30. If the portion of the second substrate 4 in contact has a surface roughness of more than 2 μm, the vacuum structure 8 is degraded, such as leaking a vacuum or generating a leakage current.

1 and 3 illustrate a case in which the reinforcing member 6 is formed by combining two or more opposite surfaces, that is, a concave surface concave toward the first substrate 2 and a convex surface toward the first substrate 2.

In this embodiment, the reinforcing member 6 has a central portion 6a which forms a partial spherical surface convex toward the first substrate 2, and a central portion 6a and the first having a concave curvature toward the first substrate 2. It consists of a body part 6b connecting the substrate 2. This reinforcing member 6 is formed by the concave curvature of the body portion 6b facing the first substrate 2 while maintaining a sufficient volume of the second region 200 while maintaining the volume of the central portion 6a facing the first substrate 2. Due to the convex curvature, there is an effect of preventing an increase in the depth of the vacuum structure 8.

The reinforcing member 6 of the above-described shape is effective in dispersing the stress by the vacuum compression force, and helps to form a stable vacuum structure. At this time, the exhaust pipe 20 may be located at the center of the central portion 6a to minimize the total length of the vacuum structure (8).

The reinforcing member may be formed in the shape shown in FIG. 4 in addition to the shape described above. Referring to FIG. 4, the reinforcing member 32 includes an opposing portion 32a disposed at a predetermined distance from the rear surface of the first substrate 2 and arranged in parallel thereto, and the first substrate 2 from an edge of the opposing portion 32a. And a skirt portion 32b extending toward the back surface and attached to the rear surface of the first substrate 2. In this case, the skirt portion 32b may be formed to have a height greater than that of the side wall 14 so that the second region 200 may have a larger volume than the first region 100.

Meanwhile, a reinforcement substrate may be provided on the rear surface of the first substrate 2 instead of the reinforcement members 6 and 32 described above. Referring to FIG. 5, a reinforcing substrate 34 is attached to a rear surface of the first substrate 2 to form a vacuum structure 8 ′ together with the first substrate 2 and the second substrate 4. The reinforcing substrate 34 is formed to have a thickness larger than that of the first substrate 2, and after all the deposition processes are completed on the first substrate 2, the reinforcing substrate 34 is attached to the outside of the first substrate 2.

The first substrate 2 and the reinforcement substrate 34 have a total thickness of at least 10 mm, preferably at least 15 mm. The reinforcing substrate 34 is bonded to the rear surface of the first substrate 2 by the frit, and reference numeral 36 in the drawing denotes the second frit layer bonding the first substrate 2 and the reinforcing substrate 34.

As shown in FIGS. 5 and 6, the reinforcing substrate 34 may have a shape having a lattice-shaped protrusion 34b by forming a plurality of recesses 34a having a square pattern on the outer surface thereof. On the other hand, although not shown, the reinforcing substrate may be formed of a flat plate having a constant thickness. The lattice-shaped reinforcement board 34 exhibits strength characteristics similar to those of a flat plate reinforcement board, thereby reducing the weight of the reinforcing board 34 to reduce the weight of the image display device.

The reinforcement substrate 34 may be formed of glass or engineering plastic. Engineering plastics are polymer resins having molecular weights of hundreds of thousands to millions, and are excellent in strength, elasticity, impact resistance, wear resistance, heat resistance, cold resistance, chemical resistance, and electrical insulation. Among various kinds of engineering plastics, thermoplastic polyamide resin may be used as the reinforcing substrate 34.

The vacuum structure 8 ′ is provided with an exhaust port for exhausting an internal space. For example, as illustrated in FIG. 5, exhaust ports 2b and 34c may be formed in the first substrate 2 and the reinforcement substrate 34. Can be. At this time, the exhaust ports 2b and 34c are located in an area in which the electron emission means 10 is not provided, that is, an ineffective area, on the first substrate 2, and reference numeral 38 in the drawing denotes an exhaust pipe.

Next, a method of manufacturing the anode pad unit described above will be described with reference to FIGS. 7A and 7B.

First, as shown in FIG. 7A, a mask 40 having an opening 40a corresponding to the shape of the anode pad portion is disposed on the second substrate 4, and the second substrate 4 exposed by the opening 40a is disposed. ) Site | part is surface-treated and the uneven surface 4a which has surface roughness of 0.2-2 micrometers is formed.

The surface treatment includes a sand blasting method of forming a concave-convex surface 4a by spraying fine sand at high speed to a portion of the second substrate 4 exposed by the opening 40a, and a second substrate exposed by the opening 40a. (4) Either a surface etching method for etching the portions to form the uneven surface 4a, and a method for forming the uneven surface by rubbing the second substrate 4 portion exposed by the opening 40a with sand paper is applied. Can be.

Next, the anode pad portion 30 shown in FIG. 7B is completed by sputtering a metal, for example chromium, on the uneven surface 4a and removing the mask 40. As described above, the anode pad part 30 formed on the uneven surface 4a has excellent adhesion to the second substrate 4, and thus, even after several cleaning processes in the process of forming a black layer and a fluorescent layer, the second substrate ( Excellent film quality can be maintained without falling off from 4).

The case where the above-described image display device is applied to the field emission display device will be described with reference to FIGS. 8 and 9.

Referring to the drawings, cathode electrodes 44 are formed on the first substrate 2 in a stripe pattern along one direction (y-axis direction of the drawing) of the first substrate 2, and cover the cathode electrodes 44. In addition, the insulating layer 46 is formed on the entire first substrate 2. Gate electrodes 48 are formed in a sprite pattern on the insulating layer 46 in a direction orthogonal to the cathode electrode 44 (the x-axis direction in the drawing).

Openings 48a and 46a are formed in the gate electrode 48 and the insulating layer 46 at each intersection of the cathode electrode 44 and the gate electrode 48 to expose a part of the surface of the cathode electrode 44. The electron emission part 50 is formed on the cathode electrode 44.

The electron emission unit 50 is formed of materials that emit electrons when an electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. Preferred materials for use as the electron emitter 50 include any one of carbon nanotubes, graphite, graphite nanofibers, diamond, diamond-like carbon, C ₆₀ and silicon nanowires, or a combination thereof, and electron emitter 50 ), Screen printing, chemical vapor deposition, sputtering or direct growth of carbon nanotubes may be applied.

On the other hand, although not shown, the electron emitting portion may be made of a composite of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si). In the above description, the case in which the gate electrode 48 is positioned above the cathode electrode 44 with the insulating layer 46 interposed therebetween is also described in the case where the gate electrode is positioned below the cathode electrode with the insulating layer interposed therebetween. It is possible.

The fluorescent screen 12 having the above-described configuration is formed on one surface of the second substrate 4 facing the first substrate 2.

When a predetermined driving voltage is applied to the cathode electrode 44 and the gate electrode 48, an electric field is formed around the electron emission part 50 by the potential difference between the two electrodes, and electrons are emitted therefrom, and the emitted electrons are emitted. They are attracted by the high voltage applied to the anode electrode 28 to the second substrate 4 and collide with the fluorescent layer of the corresponding pixel to emit light.

At this time, the vacuum structure is made of a structure that sufficiently withstands the vacuum compression force without providing a support structure therein, it is possible to increase the distance between the first substrate 2 and the second substrate 4 to 5mm or more. As a result, a high voltage of 7 kV or higher can be applied to the anode electrode 28, so that screen brightness and color reproducibility can be increased.                     

In the above, the field emission display device has been described as an example of the image display device. However, the present invention is not limited thereto and can be applied to other image display devices.

In addition, although the preferred embodiment of the present invention has 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 is within the scope of the present invention.

As described above, the image display device according to the present invention provides a stable vacuum structure that withstands the vacuum compression force without embedding a spacer. Therefore, the image display device according to the present invention is easy to manufacture, and is advantageous for ensuring high vacuum, thereby preventing the deterioration of characteristics caused by the decrease in the degree of vacuum. In addition, the image display device according to the present invention has the effect of improving the adhesion properties of the anode pad portion and the adhesion life by increasing the adhesion of the anode pad portion to the second substrate by the above-mentioned uneven surface.

Claims (13)

A first substrate provided with an electron emission section, a second substrate disposed in front of the first substrate to form a first region together with the first substrate, and a first region disposed behind the first substrate and together with the first substrate And a vacuum structure having a reinforcing member forming a second region in communication with each other, The second substrate is an image in which a metal anode electrode and a metal anode pad portion in contact with the anode electrode are formed on one surface thereof, and an uneven surface having a surface roughness of 0.2 to 2 μm is formed on the contact portion with the anode pad portion. Display. The method of claim 1, And the first substrate forms at least one through hole for allowing a first region and a second region to communicate with each other in the vacuum structure. The method of claim 1, And the second substrate and the reinforcing member have a thickness greater than that of the first substrate. The method of claim 1, An image ticket market value of which the volume of said second area is greater than or equal to twice the volume of said first area. The method of claim 1, And a central portion forming the partial spherical surface convex toward the first substrate, and a body portion connecting the central portion and the first substrate with a concave curvature toward the first substrate. The method of claim 1, And the reinforcing member having an opposing portion disposed in parallel with the first substrate at an arbitrary distance from a rear surface of the first substrate, and a skirt portion extending from the edge of the opposing portion toward the first substrate. A first substrate provided with an electron emission section; A second substrate having a thickness greater than that of the first substrate and disposed in front of the first substrate, the second substrate being provided with a metal anode electrode and a metal anode pad portion in contact with the anode electrode; And A reinforcing substrate having a thickness greater than that of the first substrate and attached to a rear surface of the first substrate and forming a vacuum structure together with the first substrate and the second substrate, And the second substrate forms a concave-convex surface having a surface roughness of 0.2 to 2 탆 at a contact portion with the anode pad portion. The method of claim 7, wherein And the reinforcing substrate forms a lattice projection on its outer surface. The method of claim 7, wherein And the reinforcing substrate is formed of any one of glass and engineering plastic. The method according to claim 1 or 7, And the anode pad portion is formed of any one material selected from the group consisting of chromium (Cr), nickel (Ni), copper (Cu), silver (Ag), and aluminum (Al). The method according to claim 1 or 7, An image display device, wherein the electron emission portion is a cold cathode electron source. (a) disposing a mask having an opening corresponding to the shape of the anode pad portion on the second substrate; (b) surface-treating the second substrate portion exposed by the opening to form an uneven surface having a surface roughness of 0.2 to 2 μm; (c) forming an anode pad part by sputtering metal on the uneven surface; An anode pad portion manufacturing method of an image display device comprising a. The method of claim 12, A method of manufacturing an anode pad portion of an image display apparatus when the uneven surface is formed by any one of a sand blasting method, a surface etching method, and a rubbing method using sand paper.

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