KR20010004329A - Method for forming front panel of pdp by using press forming - Google Patents

Abstract

PURPOSE: A method for forming a front panel of a plasma display panel using a press forming is provided to increase an area of a discharge electrode. CONSTITUTION: A method for forming a front panel of a plasma display panel comprises the following steps. The first step is to generate a plastic deformation through a heat treatment of a glass substrate under a temperature higher than a deformation point. The temperature of the heat treatment is different according to the kind of substrates, such as a soda lime glass or a high deformation point glass. The second step is to form a convex and concave portions on a surface of the glass substrate by performing a press forming of the glass substrate with a metal pattern. The third step is to form an indium tin oxide(ITO) film with the convex and concave portions and form a resist pattern using a liquid crystal resist on the ITO film. The fourth step is to form an ITO electrode(11A) by selectively etching the ITO film by the use of the resist pattern as an etching mask, and remove the resist pattern. The fifth step is to form a bus electrode(13) on the ITO electrode(11A). So, a surface area of the ITO electrode(11A) contributing to a light emission is increased.

Description

Method for Forming Plasma Display Panel Front Panel Using Press Forming {METHOD FOR FORMING FRONT PANEL OF PDP BY USING PRESS FORMING}

The present invention relates to a method for manufacturing a plasma display panel, and more particularly, to a method for forming a front plate of a plasma display panel.

Plasma display panels (hereinafter referred to as PDPs) are devices that display characters or graphics using light emitted from plasma generated during gas discharge. PDP has the advantage of being most suitable for large-scale display among various flat panel displays such as liquid crystal display (LCD), field emission display (FED), and electroluminescence display (ELD) which are being actively studied.

That is, the plasma display panel can be enlarged to 40 "or more, and CRT level colorization is possible because the ultraviolet light generated by the discharge uses a photoluminescence mechanism that emits visible light by stimulating the fluorescent film. As a self-emissive display, it has many unique advantages not found in other flat panel devices, such as a wide viewing angle of more than 160 °. It is considered as a large display device for multimedia.

PDP uses two glass substrates with a thickness of about 3 mm to apply an appropriate electrode and phosphor on each substrate, and forms plasma in the space therebetween while maintaining the distance between the two substrates at about 0.1 mm to 0.2 mm. Since it is adopted, it can be enlarged as a flat plate. In addition, in the PDP, the gas discharge has a strong non-linearity in which discharge does not occur even when a voltage is applied between electrodes, and a super large panel having a memory function that is essential for driving a large display. Even in this case, a high quality image can be expressed without deteriorating the luminance.

Plasma display panels have a direct current (DC type) in which the electrode for generating plasma is directly exposed to the plasma so that conduction current flows directly through the electrode, and the electrode is covered with a dielectric and is not directly exposed. ) Is divided into the alternating current type (AC type).

The front plate of the AC type PDP includes a pair of parallel transparent electrodes, a bus electrode formed on the transparent electrode to increase conductivity, a dielectric layer, and the like. The back plate consists of an address electrode perpendicular to the bus electrode, a dielectric layer, a partition formed on the dielectric layer, a fluorescent layer formed between the partition walls, and the like. The front plate and the back plate of such a structure are sealed and exhausted, and a PDP is manufactured.

In order to increase the luminous efficiency of the PDP, ITO (Indium Tin Oxide) transparent electrodes are being used, and efforts are being made to develop higher efficiency PDPs by changing the structure of the transparent electrodes that contribute to the discharge in various forms. For example, a technique for increasing the discharge efficiency has been developed by adding a protruding electrode in a direction in which a discharge is made to a linear ITO electrode. In addition, development is being conducted in a direction to increase the discharge area by increasing the gap between the ITO electrode area and the electrode and to reduce cross talk with adjacent cells.

However, all of the ITO electrodes developed in the related art have a planar structure in two dimensions, so there is a limit to the increase in the area of the electrode that contributes to the discharge.

The present invention devised to solve the above problems is to provide a method for forming a front plate of a plasma display panel using press molding, which can further increase the area of the discharge electrode.

1A to 1F are cross-sectional views of a front plate forming process of a plasma display panel according to an embodiment of the present invention.

2A and 2B are explanatory views for explaining the surface area increase rate of the front substrate and the electrode according to the uneven shape of the mold, respectively.

* Description of reference numerals for the main parts of the drawings *

10: glass substrate 10A: glass substrate having irregularities

11: ITO 12: liquid resist

11A: ITO electrode 12: bus electrode

In order to achieve the above object, the present invention provides a method for forming a front plate of a plasma display panel, comprising: a first step of heat-treating a glass substrate at a temperature higher than a strain point; And forming a concave-convex on the surface of the glass substrate by press molding the glass substrate with a mold having concavo-convexities on its surface under the heat treatment temperature condition of the first step. do.

After the second step, it may further include a third step of performing a heat treatment to reduce the stress applied to the glass substrate in the second step.

Further, after the third step, a fourth step of forming a transparent layer having irregularities along the surface of the glass substrate on the glass substrate; And a fifth step of forming the transparent electrode by patterning the transparent layer.

The present invention forms a front substrate having irregularities on its surface by using press molding in forming a PDP front plate, and increases the surface area of the ITO electrode which contributes to light emission by forming an ITO electrode having irregularities along the surface of the front substrate. It has its features.

Hereinafter, a method of forming a PDP front plate according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, as shown in FIG. 1A, the glass substrate 10 is heat-treated at a uniform temperature equal to or more than the strain point (distortion point) so that plastic deformation occurs. At this time, the temperature is determined according to the temperature of the glass substrate 10. For example, the heat treatment temperature is set according to the type of the substrate such as soda lime glass and high strain point glass.

In FIG. 1A, reference numeral 20 denotes a heater and 21 denotes a heating element.

Next, as shown in FIG. 1B, the metal mold | die 30 in which the uneven | corrugated shape was defined is provided, and press molding is performed, maintaining the glass substrate 10 at the temperature more than the strain point which hot forming of a glass substrate is performed. When using soda-lime glass, press molding is performed at the temperature of 600 degreeC or more. On the other hand, the mold 30 uses a stainless-based mold that can be easily separated from the glass substrate 10 after press work because the adhesion with the glass substrate 10 is low.

After forming the glass substrate 10A having irregularities on the surface according to the press working, in order to prevent cracking of the glass substrate 10A in the subsequent process due to the residual stress generated in the press molding, The heat treatment is performed for a long time to soften the structure of the cured glass substrate.

As a result of this process, as shown in FIG. 1C, a glass substrate 10A having irregularities is formed.

Next, as shown in FIG. 1D, the ITO film 11 is formed on the glass substrate 10A having the unevenness, thereby forming the ITO film 11 having the unevenness, and the liquid phase is formed on the ITO film 11. The resist pattern 12 using the resist is formed.

Next, as shown in FIG. 1E, the ITO film 11 is selectively etched using the resist pattern as an etch mask to form the ITO electrode 11A, and the resist pattern is removed.

Next, as shown in Fig. 1F, a bus electrode 13 is formed on the ITO electrode 11A.

Thereafter, a dielectric, an MgO protective film, and the like are formed.

In the above-described embodiment of the present invention, the mold 30 has a continuous hemispherical shape as shown in FIG. 1B, or is embossed in the form of a sine wave so as to be formed on a glass substrate as shown in FIG. 2A. It may have embossing, or it may have serrated irregularities.

2A and 2B are explanatory views for explaining the surface area increase rates of the front substrate and the electrode according to the uneven shape of the mold, respectively.

FIG. 2A illustrates the surface growth rate when the mold 31 having the sinusoidal irregularities is used. The straight length 'a' in the absence of the irregularities is the length of 'L' in accordance with the formation of the sinusoidal irregularities. Will increase. Assuming that the sine wave irregularities are the circumference of the circle having a radius r and the center angle (φ) is 90 °, in the structure as shown in FIG. In this case, it can be seen that in this case, the area of the ITO electrode is increased by about 10% than before forming by pressing.

Figure 2b is for explaining the surface increase rate in the case of using a mold 32 having a tooth-shaped unevenness, the length of "L" in accordance with the formation of the sawtooth unevenness in the straight length 'a' in the absence of unevenness Will increase. In the structure as shown in FIG. 2B, when θ is 45 °, L = 1.414a, and in this case, the area of the ITO electrode may be increased by about 40% than before forming by pressing.

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

The present invention made as described above is press-processed into a mold having irregularities to form a front substrate having irregularities on the surface thereof, and an ITO electrode having irregularities along the surface of the front substrate to form an area and discharge characteristics of the front substrate. Can change.

Claims (6)

In the method of forming the front plate of the plasma display panel, A first step of heat-treating the glass substrate at a temperature higher than the strain point; And A second step of forming irregularities on the surface of the glass substrate by press molding the glass substrate with a mold having irregularities on the surface thereof under the heat treatment temperature condition of the first step; Method for forming a front plate of the plasma display panel comprising a. The method of claim 1, After the second step, And a third step of performing a heat treatment to reduce the stress applied to the glass substrate in the second step. The method of claim 2, After the third step, A fourth step of forming a transparent layer having irregularities along the surface of the glass substrate on the glass substrate; And And forming a transparent electrode by patterning the transparent layer. The method of claim 3, wherein And a sixth step of forming a bus electrode on the transparent electrode. The method according to any one of claims 1 to 4, The mold is A method of forming a front plate of a plasma display panel, characterized by having hemispherical, sinusoidal, or serrated irregularities. The method of claim 5, And forming the transparent electrode from indium tin oxide (ITO).