KR100823203B1 - Structure of front plate of pdp and manufacturing method thereof - Google Patents

Abstract

A front plate of a PDP(Plasma Display Panel) and a manufacturing method thereof are provided to improve light emitting efficiency of the PDP by decreasing a visual ray loss by forming a transparent dielectric only on an aluminum surface. An aluminum material is patterned in various shapes, such that a sustain electrode shape(47) is obtained. An aluminum oxide film(46) is formed on the aluminum electrode. A magnesium oxide layer is formed as a protective film(48), such that a surface aluminum oxide film serves as a dielectric film on an electrode surface. The aluminum oxide has a high voltage withstanding property and a low relative dielectric constant. A thickness of the aluminum electrode is between 5 and 100 mum. A thickness of the aluminum oxide film is between 1 and 20 mum.

Description

Front panel structure of plasma display device and its manufacturing method {STRUCTURE OF FRONT PLATE OF PDP AND MANUFACTURING METHOD THEREOF}

1 is a cross-sectional perspective view schematically showing the structure of a plasma display element;

2 is a schematic diagram of a front substrate structure according to the prior art;

3 is a schematic diagram of a front substrate structure provided by the present invention;

4 is a schematic view of the head of the paste injecting member for causing the downward and forward flow of the paste into the mold cavity in the present invention;

5 is a schematic process diagram of a manufacturing process according to one embodiment of a mold to be used in the present invention;

6 is a schematic process diagram of some processes of a method of manufacturing a partition wall using a flat mold in the method according to the present invention;

7A and 7B are schematic process diagrams of some processes of a method of manufacturing a partition wall using a roller mold in the method according to the present invention.

The present invention relates to a front panel structure of a plasma display device (PDP) and a method of manufacturing the same.

PDP is a flat panel display device, and is mainly used for large display devices of 40 inches or more because of its excellent image quality, thin thickness, and light weight. In the plasma display device, a pixel is formed at a point where the barrier rib formed on the bottom plate, the address electrode, and the sustain electrode formed on the top plate vertically cross each other to implement an image.

A schematic structure of such a PDP is shown in FIG. 1. The dielectric layer 90 is coated on the bottom plate 80 made of a glass or metal substrate, and the address electrode 50 is formed on the bottom plate 80 or the dielectric layer 90. A long stripe-shaped partition wall 60 exists with the address electrode 50 interposed therebetween, and phosphors are coated on the spaced surface between the partition walls 60 to form a sub pixel. A sustain electrode 40 is formed in the upper plate 10 made of glass, and a dielectric 20 and an MgO protective layer 30 are present below it. The electrode structure of the front plate is shown in more detail in FIG. 2, wherein the sustain electrode is composed of an Ag BUS electrode 42 and an ITO transparent electrode 41. The Ag BUS electrode is a voltage generated because the ITO electrode has high electrical resistance. It serves to prevent descent. When the upper plate 10 and the lower plate 80 are combined, a plurality of pixel spaces separated by the partition wall 60 are formed. He / Xe gas or Ne / Xe gas is enclosed in such an isolation space. When voltage is applied to the sustain electrode 40 and the address electrode 50, plasma is formed in the space, and the vacuum ultraviolet rays generated from the plasma are generated. (vacuum ultra vilolet) excites the phosphor coated on the side walls and the bottom of the partition walls, thereby generating red, green and blue visible light.

Ag has typically been used as a bus electrode material in the front panel. After applying a paste or sheet containing Ag powder to a glass substrate, patterning is performed through exposure / development or the like. ) Has been used mainly. However, a method for using aluminum, which is less expensive than Ag, as an electrode material is disclosed in US Pat. No. 6.037,713 and US Pat. No. 6,517,400. In US Pat. No. 6.037,713, an aluminum thin film is formed on a glass substrate to a thickness of 500 to 4,000 nm by CVD, vacuum deposition, and sputtering, and then chromium is suppressed to suppress oxidation reaction and diffusion during firing of aluminum and a transparent glass dielectric. Methods of coating oxides are provided. In US Pat. No. 6,517,400, an aluminum film is laminated on a ceramic paste to be adhered and patterned in the form of an electrode, or a photoresist is patterned on a substrate and then plated with Cu or the like to obtain an electrode form. In order to suppress interfacial oxidation reactions, a method of coating Ni or Cr is provided.

These methods offer the possibility of reducing the material cost by replacing the expensive Ag BUS electrode materials used with low-cost aluminum, but the process is complicated in multiple steps, and the existing three-electrode surface discharge faceplate structure is retained. As a result, the impact on PDP performance improvement and manufacturing cost reduction is limited.

Accordingly, the present invention provides a novel front plate structure and a method of manufacturing the same, which replaces the three-electrode surface discharge front plate structure and manufacturing process, thereby solving the problems of the prior art and technical problems that have been desired from the past. For the purpose.

According to the above object, the present invention replaces the front plate composed of the traditional structure of ITO electrode / Ag BUS electrode / transparent glass dielectric film / MgO protective film with a simple structure of Al / Al ₂ O ₃ / MgO protective film or Al / MgO protective film. will be. In another aspect, the present invention provides a method for manufacturing a PDP front plate structure consisting of forming an aluminum oxide dielectric film or an MgO dielectric and a protective film by anodizing after aluminum is patterned into various types of electrode structure. More specifically, the present invention provides a method for manufacturing a partition wall of a front plate having excellent visible light transmittance and a simplified manufacturing process.

Looking at this in detail.

 First, a front plate structure composed of the glass substrate 10 / ITO electrode 41 / Ag BUS electrode 42 / transparent glass dielectric film 20 / MgO protective film 30 according to the conventional technique shown in FIG. Glass substrate 10 as shown in 3 (A) / adhesive layer 45 / aluminum 47 / aluminum oxide dielectric film 46 / MgO protective film 48 or glass substrate as shown in Fig. 3 (B) ( 10) / adhesive layer 45 / aluminum electrode 47 / MgO dielectric and protective film 44 are provided.

 Second, by replacing expensive Ag electrode and ITO electrode with low-cost aluminum electrode, it provides technology that can drastically reduce the manufacturing cost of PDP by reducing material cost and simplifying process.

Third, by replacing the existing glass transparent dielectric film with an alumina dielectric film formed only on the surface of the aluminum electrode, it provides a technology that can reduce the power consumption of the PDP by improving the luminous efficiency of the PDP by eliminating visible light transmittance loss through the transparent dielectric film. do.

Fourthly, the present invention provides a technology that can dramatically reduce the manufacturing cost of PDP by improving the yield by simplifying the manufacturing process and structure.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The front panel structure for the plasma display device (PDP) provided by the present invention is shown in FIG. 3. As shown in FIG. 3A, the aluminum material is patterned into various shapes to pattern the sustaining electrode shape 47, and after forming the aluminum oxide 46 film on the surface of the aluminum electrode, the magnesium oxide layer is used as the protective film 48. As shown in FIG. The aluminum oxide film on the surface of the aluminum electrode serves as a dielectric film on the electrode surface required for ac-PDP. Since aluminum oxide has excellent withstand voltage characteristics and has a relatively low relative dielectric constant of about 9, aluminum oxide has suitable characteristics as a dielectric material requiring excellent withstand voltage characteristics and appropriate capacitance.

Further, as shown in FIG. 3B, the aluminum material is patterned in various forms to pattern the sustaining electrode shape 47, and after the magnesium oxide 49 film is formed on the surface of the aluminum electrode, the magnesium oxide layer is protected by the protective film 44. The magnesium oxide film on the surface of the aluminum electrode serves as a dielectric film on the electrode surface required by ac-PDP. Since magnesium oxide has excellent withstand voltage characteristics and has a relatively low relative dielectric constant of about 9, magnesium oxide has suitable characteristics as a dielectric material requiring excellent withstand voltage characteristics and appropriate capacitance.

In the structure provided by this invention, it is preferable that the thickness of an aluminum electrode exists in the range of 5 micrometers-100 micrometers. More preferably, the thickness should be in the range of 5 μm to 20 μm. The width of the electrode is preferably in the range of 50 μm to 200 μm, more preferably in the range of 50 μm to 100 μm. The aluminum oxide or magnesium oxide dielectric film on the surface of the electrode must be in the range of 1 µm to 20 µm in order to satisfy the characteristics required by ac-PDP. More preferably, it is in the range of 5 micrometers-10 micrometers.

In the structure provided by the present invention, the aluminum electrode pattern includes at least one stripe-shaped scan electrode 55 and the holding cell with respect to a discharge cell composed of a partition wall 65 having a rectangular or waffle type as shown in FIG. 4A. It is possible to form the electrode 56, and to form the square scan electrode 55 and the sustain electrode 56 shown in Fig. 4B in order to maintain the voltage applied to the electrode uniformly. In the above structure, the width of the aluminum electrode pattern is maintained at a cell opening ratio of 70% or more with respect to the area of the discharge cell, so that the visible light generated in the discharge cell is blocked by the aluminum electrode. The degradation can be reduced.

Preferred manufacturing processes for implementing the structure are described below. 5A-5G provide one method of implementing the structure. First, the pressure-sensitive adhesive layer 45 is formed on the surface of the glass substrate 10 by lamination, or the pressure-sensitive adhesive slurry is coated, followed by drying to form the pressure-sensitive adhesive layer 45 (FIG. 5A). It is preferable that the adhesive tape and the slurry for adhesion contain an organic adhesive, a glass powder, a coloring agent, and other additives. The glass powder was converted into PbO-SiO ₂ -B ₂ O ₃ , Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ , ZnO-B ₂ O ₃ -SiO ₂ and P ₂ O ₅ -B ₂ O ₃ -SiO ₂ Any of low melting point solder glass materials having a sintering temperature of at least 600 ° C. having at least one selected from the group consisting of these may be used. The method of coating the adhesive slurry may include a doctor blade coating method, a die coating method, a screen printing method, a spin coating method and a dipping method. Can be.

The aluminum foil 47 or the sheet 47 is attached to the upper portion of the adhesive layer formed by the above process by heating / pressurizing using a roll lamination method or the like (FIG. 5B). At this time, it is necessary to prevent air from being trapped at the interface between the adhesive layer and the aluminum foil. The photoresist is coated on the surface of the aluminum layer thus formed, and exposed and developed in the shape of an aluminum electrode to form an etching protection pattern film 75 (FIG. 5C). The substrate thus prepared is chemically etched and removed to protect the photoresist using an aluminum etching solution to form an aluminum electrode pattern (FIG. 5E). The substrate on which the aluminum pattern is formed is heated to the firing temperature of the glass so as to be chemically bonded to the substrate glass and the aluminum electrode. At this time, the portion of the fired adhesive glass layer 45 that does not contact the aluminum electrode may be removed as shown in FIG. 5E. This is because it is advantageous to use colored glass such as black as the adhesive glass material in order to improve the bright room contrast ratio of the PDP. The adhesive glass layer may be removed by etching by using an aqueous solution including nitric acid (HNO ₃ ).

The substrate to which the aluminum electrode pattern is chemically adhered to the glass substrate is immersed in an anodizing solution of aluminum, and voltage is applied to the aluminum electrode to induce an anodizing reaction to form an aluminum oxide film (FIG. 5F). The anodizing solution can use various solutions, such as a phosphoric acid type, a sulfuric acid type, a hydroxyl type, and a chromic acid type. At this time, it is possible to perform an intermediate heat treatment process or multiple anodizing treatment to minimize the occurrence of defects such as cracking of the alumina oxide film formed by anodizing on the electrode surface.

The front plate formed by the above process is heated to remove moisture and other impurities contained in the aluminum oxide film during anodizing, and then a magnesium oxide protective film is formed on these surfaces (FIG. 5G). In the above process, the heating temperature is preferably in the range of 250 ° C to 550 ° C. The magnesium oxide protective film may be electron-beam evaporation, ion plating, sputtering, chemical vapor deposition, or the like, and the protective film layer may have a thickness of 500 nm to 1000 nm. desirable. In addition, a magnesium oxide protective film can be formed by using a thick film formation method. Electrophoresis is performed by dipping a treated material up to FIG. 5F in a solution in which nano-sized magnesium oxide powder is dispersed, and then applying a voltage to an aluminum electrode to coat it. Law can be used. It is also possible to use common thick film processes such as screen printing and spin coating as the thick film formation method.

6A to 6E provide another method of implementing the structure. First, the pressure-sensitive adhesive layer 45 is formed on the surface of the glass substrate 10 by lamination, or the pressure-sensitive adhesive slurry is coated, followed by drying to form the pressure-sensitive adhesive layer 45 (FIG. 6A). It is preferable that the adhesive tape and the slurry for adhesion contain an organic adhesive, a glass powder, a coloring agent, and other additives. The glass powder was converted into PbO-SiO ₂ -B ₂ O ₃ , Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ , ZnO-B ₂ O ₃ -SiO ₂ and P ₂ O ₅ -B ₂ O ₃ -SiO ₂ Any of low melting point solder glass materials having a sintering temperature of at least 600 ° C. having at least one selected from the group consisting of these may be used. The method of coating the adhesive slurry may include a doctor blade coating method, a die coating method, a screen printing method, a spin coating method and a dipping method. Can be.

The aluminum foil 47 or the sheet 47 is attached to the upper portion of the adhesive layer formed by the above process by heating / pressurizing using a roll lamination method or the like (FIG. 6B). At this time, it is necessary to prevent air from being trapped at the interface between the adhesive layer and the aluminum foil. The aluminum layer and the adhesive layer thus formed are formed of an electrode pattern using a high energy heat source such as a laser (FIG. 6C). Argon laser, Ng-YAG laser, excimer laser, etc. can be used as a laser heat source.

The substrate on which the aluminum electrode pattern is formed is heated to the firing temperature of the glass so as to be chemically bonded to the substrate glass and the aluminum electrode. The substrate to which the aluminum electrode pattern is chemically adhered to the glass substrate is immersed in an anodizing solution of aluminum, and voltage is applied to the aluminum electrode to induce an anodizing reaction to form an aluminum oxide film (FIG. 6D). The anodizing solution can use various solutions, such as a phosphoric acid type, a sulfuric acid type, a hydroxyl type, and a chromic acid type. At this time, it is possible to perform an intermediate heat treatment process or multiple anodizing treatment to minimize the occurrence of defects such as cracking of the alumina oxide film formed by anodizing on the electrode surface.

The front plate formed by the above process is heated to remove moisture and other impurities contained in the aluminum oxide film during anodizing, and then a magnesium oxide protective film is formed on these surfaces (FIG. 6E). In the above process, the heating temperature is preferably in the range of 250 ° C to 550 ° C. As the magnesium oxide protective film, electron-beam evaporation, ion plating, sputtering, chemical vapor deposition, or the like may be used, and the thickness of the protective film layer is preferably 500 nm to 1000 nm. Do. In addition, a magnesium oxide protective film can be formed by using a thick film formation method. Electrophoresis is performed by dipping a treated material up to FIG. 5F in a solution in which nano-sized magnesium oxide powder is dispersed, and then applying a voltage to an aluminum electrode to coat it. Law can be used. It is also possible to use common thick film processes such as screen printing and spin coating as the thick film formation method.

The present invention also relates to an alternating current plasma display element (ac-PDP) which comprises a front plate manufactured by a method using such a structure and material. Since a method for manufacturing a PDP using the front plate manufactured by the above method and the back plate manufactured by the existing process is well known in the art, a detailed description thereof will be omitted.

As described above, according to the structure and material of the ac-PDP faceplate of the present invention, aluminum having excellent electrical conductivity is used as the electrode material in place of the existing ITO and Ag BUS electrode materials, and transparent in the existing faceplate structure. While the glass dielectric is uniformly coated on the whole, in the present invention, since visible light loss due to the transparent dielectric is eliminated by forming only on the aluminum surface, it is possible to reduce manufacturing costs of the existing ac-PDP and to improve luminous efficiency. As a result, the ac-PDP front panel structure and manufacturing method provided by the present invention can improve the product reliability of the PDP front panel, improve the yield of the product and improve the uniformity of quality, such an electrode forming process is Manufacturing costs can be drastically reduced.

Those skilled in the art to which the present invention pertains will be capable of various applications and modifications within the scope of the present invention based on the above contents. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (13)

 An AC PDP front panel, wherein an aluminum oxide dielectric film and an MgO protective film or an MgO dielectric and protective film are formed on a glass substrate, an adhesive layer, and an aluminum sustain electrode which are sequentially stacked. The front plate structure for an AC PDP according to claim 1, wherein the aluminum sustain electrode stripe type or square pattern has a pattern, and the area fraction of the aluminum sustain electrode pattern occupies the surface area of the discharge cell is 30% or less. The front plate structure for an AC PDP according to claim 1, wherein the thickness of the aluminum sustain electrode is 5 µm to 100 µm. The front plate structure for an AC PDP according to claim 1, wherein the aluminum oxide dielectric film has a thickness of 2 µm to 20 µm. The front plate structure for an AC PDP according to claim 1, wherein the adhesive layer between the aluminum electrode and the glass substrate uses a colored low melting glass material. 6. The front plate structure for AC PDP according to claim 5, wherein the glass material has a color of black to gray and is excellent in absorbance to visible light, and the firing temperature of the glass is 600 ° C or lower. The composition of claim 5, wherein the composition of the glass material is PbO-SiO ₂ -B ₂ O ₃ , Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ , ZnO-B ₂ O ₃ -SiO ₂ , and P ₂ O _5. A front plate structure for an AC PDP, characterized in that the glass is a low melting point glass composed mainly of one or more selected from the group consisting of -B ₂ O ₃ -SiO ₂ . The aluminum foil or sheet is adhered to the adhesive layer, and then patterned, and then PbO-SiO ₂ -B ₂ O ₃ , Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ , ZnO-B ₂ O contained in the adhesive layer. Consisting of forming an aluminum electrode by heating a glass containing at least one selected from the group consisting of ₃ -SiO ₂ , and P ₂ O ₅ -B ₂ O ₃ -SiO ₂ to a temperature to be fired, to form an MgO film. The manufacturing method of the front plate structure for AC PDP containing the method. The method according to claim 8, further comprising a step of forming an aluminum oxide dielectric film by an aqueous solution anodizing step after forming the aluminum electrode and before forming the MgO film. 10. A method according to claim 8 or 9, wherein the patterning is formed using a laser. 10. The method of claim 9, wherein the aqueous solution anodizing process comprises using an acid solution, phosphoric acid, or chromic acid sulfate as an aqueous solution anodizing solution, and including heat treatment in the range of 250 ° C to 550 ° C to remove impurities such as defects and moisture in the anodizing layer. Manufacturing method characterized in that. The method of claim 8 or 9, wherein the magnesium oxide film is e-beam evaporation, ion plating, sputtering, CVD, electrophoresis, printing, spin coating, blade coating, or die coating (10). It is formed by the die coating method. Plasma display device comprising a front plate having the structure of claim 1.

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