KR100649522B1 - Plasma display panel - Google Patents

Abstract

The present invention relates to a plasma display panel, and in particular, the plasma display panel includes first and second substrates disposed substantially parallel to each other at random intervals, a plurality of address electrodes formed on the first substrate, and A first dielectric layer formed on the first substrate while covering the address electrodes, a plurality of partition walls provided on the first dielectric layer at a predetermined height to form a discharge space, a fluorescent layer formed in the discharge space, and the first substrate A plurality of display electrodes including a sustain electrode and a scan electrode and a second dielectric layer formed on the second substrate while covering the display electrodes and disposed in a direction crossing the address electrodes on one surface of the second substrate opposite to And a passivation layer coating the second dielectric layer, wherein the passivation layer is polycrystalline in a region corresponding to the scan electrode. MgO is included, and the region corresponding to the sustain electrode contains single crystal MgO.

When the protective film is formed, the response speed is improved by using a polycrystalline MgO material in the region corresponding to the scan electrode, and the monolithic MgO material is used on the entire surface of the display area, whereby discharge stability and temperature resistance characteristics can be effectively improved.

Description

Plasma Display Panel {PLASMA DISPLAY PANEL}

1 is a partially exploded perspective view showing an example of a plasma display panel of the present invention.

2 is a graph showing a discharge delay time of a plasma display panel manufactured according to Comparative Example 1. FIG.

3 is a graph showing a discharge delay time of a plasma display panel manufactured according to Comparative Example 2. FIG.

[Industrial use]

The present invention relates to a plasma display panel, and more particularly, to a plasma display panel having excellent response speed, discharge stability, and temperature resistance characteristics.

[Prior art]

Plasma display panel (PDP) is a device that displays letters or graphics by using the light emitted from the plasma generated during gas discharge, by applying a predetermined voltage to the two electrodes installed in the discharge space of the plasma display panel Plasma discharge is caused to occur between them, and the phosphor layer formed in a predetermined pattern is excited by ultraviolet rays generated during the plasma discharge to form an image.

Such plasma displays are largely divided into AC type, DC type, and hybrid type. AC type is the most widely used. A typical plasma display panel includes a lower substrate, a plurality of address electrodes formed on the lower substrate, a dielectric layer formed on the lower substrate on which the address electrodes are formed, and formed on the dielectric layer to maintain a discharge distance and prevent cross talk between cells. It includes a plurality of partitions and the phosphor layer formed on the surface of the partitions. The plurality of display electrodes are formed under the upper substrate so as to be spaced apart from the plurality of address electrodes formed on the lower substrate at predetermined intervals. The dielectric layer and the passivation layer sequentially cover the display electrode. In particular, as the protective film, MgO, which is not only transparent to transmit visible light but also excellent in dielectric layer protection and secondary electron emission performance, is mainly used.

Since the MgO protective film is in contact with the discharge gas, the components constituting the protective film and the film characteristics can greatly affect the discharge characteristics. At this time, the MgO protective film properties largely depend on the components and the deposition conditions during deposition.

Therefore, there is an urgent need to develop optimal components to meet the desired film properties.

The present invention is to solve the above problems, an object of the present invention is to provide a plasma display panel having improved response speed, discharge stability and temperature resistance characteristics.

In order to achieve the above object, the present invention provides a first substrate and a second substrate disposed substantially parallel at any interval, a plurality of address electrodes formed on the first substrate and the first substrate while covering the address electrodes A first dielectric layer formed on the first dielectric layer, the plurality of partition walls provided on the first dielectric layer at a predetermined height to form a discharge space, a fluorescent layer formed in the discharge space, and one surface of the second substrate facing the first substrate. A plurality of display electrodes including a storage electrode and a scan electrode and a second dielectric layer formed on the second substrate while covering the display electrodes, the second dielectric layer being disposed in a direction crossing the address electrodes and coating the second dielectric layer. A protective film comprising polycrystalline MgO in a region corresponding to the scan electrode, and a single crystal MgO in a region corresponding to the sustain electrode. It includes.

The protective film may include polycrystalline MgO in a region corresponding to the scan electrode, and may include single crystal MgO in the other protective film region.

Hereinafter, the present invention will be described in more detail.

In the three-electrode structure (address electrode (A electrode), sustain electrode (X electrode), and scan electrode (Y electrode)) of the plasma display panel, the sustain discharge is generated between the X and Y electrodes, but the cell is turned on for the sustain discharge to occur. The address discharge for determining the above occurs between the A and Y electrodes. On the surfaces of the dielectric layers covering the sustain electrodes and the scan electrodes, a protective film having high sputter resistance is formed in order to reduce ion bombardment caused by discharge gas during discharge.

In the plasma display panel, since the material and the film characteristics of the protective film greatly influence the discharge characteristics, the protective film functions as a discharge electrode. As such a protective film, an MgO film having excellent sputter resistance and high secondary electron emission coefficient is used. The sintered polycrystalline MgO material commonly used as the material of the MgO film has a disadvantage in that the display quality is changed due to a difference in time in response to a writing signal according to a temperature change, whereas a single crystal MgO produced in a fusion is made. The material has a slower response time than polycrystalline MgO material but is insensitive to temperature changes.

According to the present invention, the stability of the single crystal MgO material and the fast response of the polycrystalline MgO material are mixed. In the protective film region corresponding to the scan electrode, the response speed is improved by using the polycrystalline MgO material and the region corresponding to the sustain electrode is single crystal. By using MgO materials, discharge stability and temperature resistance characteristics could be effectively improved.

That is, the plasma display panel of the present invention includes polycrystalline MgO in the region corresponding to the scan electrode (Y electrode) and single crystal MgO in the region corresponding to the sustain electrode.

The protective film may include polycrystalline MgO in a region corresponding to the scan electrode, and may include single crystal MgO in the other protective film region.

The polycrystalline MgO preferably has a MgO purity of 99% or more, and more preferably 99.9% or more. If the purity of the polycrystalline MgO is less than 99%, it is not preferable because it affects the deposited film properties and temperature dependence due to the influence of impurities added in the production of MgO source (MgO source).

In addition, the polycrystalline MgO preferably has a relative density of 3.2 or less, and more preferably 3 or less.

The protective film preferably has an average thickness of 3000 to 8000 GPa, and more preferably 3000 to 6000 GPa.

FIG. 1 is a partially exploded perspective view showing an example of the plasma display panel of the present invention having the protective film. The plasma display panel of the present invention is not limited to FIG. 1.

As shown in FIG. 1, in the plasma display panel of the present invention, address electrodes 3 are formed in one direction (Y direction in the drawing) on a first substrate 1 and a lower substrate, The first dielectric layer 5 is formed on the first substrate 1 while covering the field 3. A partition wall 7 is formed between the address electrodes 3 on the first dielectric layer 5, and the partition wall 7 may be formed as an open type or a closed type as necessary. Between each partition wall 7, phosphor layers 9 of red (R), green (G) and blue (B) colors are located. In addition, display electrodes 13 including scan electrodes and sustain electrodes are formed on one surface of the second substrate 11 (upper substrate) opposite to the first substrate 1 in a direction crossing the address electrode 3. The scan electrode and the sustain electrode are composed of a pair of transparent electrodes 13a and a bus electrode 13b. In addition, the second dielectric layer 15 and the passivation layer 17 are disposed on the entire second substrate 11 while covering the display electrodes 13.

The passivation layer 17 includes polycrystalline MgO in a region corresponding to the scan electrode (Y electrode), single crystal MgO in a region corresponding to the sustain electrode, and preferably includes polycrystalline MgO in a region corresponding to the scan electrode. In addition, the other protective film region may contain single crystal MgO.

The plasma display panel is manufactured by applying the edges of the upper and lower substrates of the plasma display panel manufactured as described above with frit to seal both substrates and injecting discharge gas such as Ne or Xe.

In the plasma display panel according to the embodiment of the present invention, a driving voltage is applied from the electrodes to generate an address discharge between the electrodes, thereby forming wall charges in the dielectric layer, and forming the wall charges on the upper substrate in the discharge cells selected by the address discharge. Sustain discharge is caused between these electrodes by an alternating current signal supplied alternatingly to a pair of electrodes. As a result, the discharge gas charged in the discharge cells forming the discharge cells is excited and transitioned to generate ultraviolet rays, and to generate an image while generating visible light by excitation of the phosphor by the ultraviolet rays.

In the plasma display panel according to the embodiment of the present invention, a driving voltage is applied from the electrodes to generate an address discharge between the electrodes, thereby forming wall charges in the dielectric layer, and forming the wall charges on the upper substrate in the discharge cells selected by the address discharge. Sustain discharge is caused between these electrodes by an alternating current signal supplied to a pair of electrodes. Accordingly, the discharge gas charged in the discharge space forming the discharge cell is excited and transitioned to generate ultraviolet rays, and to generate an image while generating visible light by excitation of the phosphor by the ultraviolet rays.

Since the method of manufacturing the plasma display panel of the present invention having the above-described structure is well known in the art, detailed description thereof will be omitted since it is well understood by those skilled in the art. However, the main features of the present invention will be described in detail only for the forming process of the protective film.

MgO protective film of the present invention has a sputtering property that can mitigate the effects of the ion impact of the discharge gas during discharge during plasma display panel operation to protect the dielectric layer from ion collision and to lower the discharge voltage through the emission of secondary electrons The transparent protective thin film is formed by covering a dielectric layer with a thickness of 3000 to 8000 Å.

Polycrystalline MgO or single crystal MgO, which is the MgO protective film forming material, is not particularly limited in its production method, but polycrystalline MgO is manufactured using a general sintering method, and single crystal MgO is manufactured using a melting method.

Specifically, in the case of polycrystalline MgO, MgO powder is mixed and dried to undergo a compression and molding process, and then crystal growth is performed at a high temperature of 1200 ° C. In addition, as an example of the melting method for producing single crystal MgO, the Arc melting method is a method of melting the raw material at a high temperature of 3000 ℃ in the crucible and slowly cooling and inducing single crystal growth through crystal nuclei generated during reduction. Blocks may be prepared by the arc melting method, and the prepared blocks may be processed into vacuum deposition pellets.

The protective film of the present invention may be formed by a thick film printing method using a paste and a deposition method using a plasma. Among them, the deposition method is relatively resistant to sputtering due to the impact of ions, and the discharge sustain voltage and the discharge start voltage due to secondary electron emission. It is desirable to be able to reduce.

The method of forming the protective film by the plasma deposition method is magnetron sputtering, electron beam deposition, IBAD (ion beam assisted deposition), CVD (chemical vapor deposition), sol-gel (sol-gel) method Alternatively, ion plating may be performed by ionizing the evaporated particles, and ion plating may be used for the adhesion and crystallinity of the MgO protective film, similar to the sputtering method, but with the advantage that deposition can be performed at a high speed of 8 nm / s. More preferably, electron beam evaporation.

The plasma display panel of the present invention includes a MgO protective film containing polycrystalline MgO in a region corresponding to a scan electrode (Y electrode) and a single crystal MgO in a region corresponding to a sustain electrode, whereby the polycrystalline MgO is prepared by melting a single crystal. Since the response speed is relatively faster than that of MgO, the probability of discharge success can be increased, and the problem of deterioration of display quality due to delay in response speed can be solved.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention and the present invention is not limited to the following examples.

(Example 1)

A display electrode was formed in a stripe shape in a conventional manner using an indium tin oxide conductor material on an upper substrate made of soda lime glass.

Subsequently, a paste of lead-based glass was coated over the entire surface of the upper substrate on which the display electrode was formed and baked to form a dielectric layer.

An upper substrate was manufactured by fabricating a protective film containing polycrystalline MgO having a purity of 99.9% MgO in a region corresponding to a scan electrode (Y electrode) and a single crystal MgO in a region corresponding to a sustain electrode using an electron beam deposition method on the dielectric layer. . The average thickness of the protective film produced was 5000 kPa. The film forming conditions were 1.0X10 ^-9 Pa in the attained vacuum degree, 1.0X10 ^-2 Pa in the partial pressure of oxygen gas, the substrate temperature was 200 deg. C, and the film formation rate was 20 Pa / sec.

(Comparative Example 1)

A protective film was prepared in the same manner as in Example 1 except that only single crystal MgO was used to prepare an upper substrate.

(Comparative Example 2)

A protective film was prepared in the same manner as in Example 1 except that only polycrystalline MgO was used to prepare an upper substrate.

2 and 3 are graphs showing the discharge delay time of the plasma display panel manufactured according to Comparative Examples 1 and 2. The measurement was performed 500 times in the upper left upper part and the front left lower part of the plasma display panel, respectively. The Y-axis value of 1 in FIGS. 2 and 3 means that the discharge generation rate is 1, and is a relative ratio of the data for which no discharge occurs in the measured total data.

As shown in FIGS. 2 and 3, the plasma display panel of Comparative Example 1 including single crystal MgO has a long response delay time, and the plasma display panel of Comparative Example 2 including polycrystalline MgO has a short response delay time. From this, it could be seen that the response time of the plasma display panel was changed depending on the characteristics of MgO, which is a constituent material in the protective film.

In addition, the room temperature (25 ℃), and high temperature to determine the change in the formation delay time (Tf) and the statistical delay time (Ts) according to the external temperature of the plasma display panel manufactured according to Example 1 and Comparative Examples 1 and 2 Operation at (60 ° C.) measured formation delay time and statistical delay time. Formation delay time (Tf) and statistical delay time (Ts) at each temperature are shown in Table 1 below.

Example 1 Comparative Example 1 Comparative Example 2 Tf (ns) Ts (ns) Tf (ns) Ts (ns) Tf (ns) Ts (ns) Room temperature 500 223 526 474 169 80 High temperature 446 142 521 454 148 54

As shown in Table 1, the plasma display panel of Example 1 including both monocrystalline MgO and polycrystalline MgO is slower in response time than in the plasma display panel of Comparative Example 2 including polycrystalline MgO, but includes only single crystal MgO. It was confirmed that the response speed was improved compared to the plasma display panel of Comparative Example 1.

According to the present invention, the response speed is improved by using a polycrystalline MgO material in a region corresponding to the scan electrode and a single crystal MgO material is used in a region corresponding to the eugeneous electrode, thereby effectively improving discharge stability and temperature resistance characteristics.

Claims (5)

First and second substrates disposed substantially parallel at any interval; A plurality of address electrodes formed on the first substrate and a first dielectric layer formed on the first substrate while covering the address electrodes; A plurality of partition walls provided on the first dielectric layer at a predetermined height and forming a discharge space; A fluorescent layer formed in the discharge space; A plurality of display electrodes including a sustain electrode and a scan electrode and the display electrodes and the display electrodes are disposed on one surface of the second substrate opposite to the first substrate, and are formed on the second substrate. A second dielectric layer; And A protective film for coating the second dielectric layer, The protective film includes polycrystalline MgO in a region corresponding to the scan electrode and single crystal MgO in a region corresponding to the sustain electrode. The method of claim 1, And the protective film includes polycrystalline MgO in a region corresponding to a scan electrode and single crystal MgO in another protective film region.   The method of claim 1, The protective film is a plasma display panel having an average thickness of 3000 to 8000 Å. The method of claim 1, Wherein the polycrystalline MgO has a purity of 99% or more. The method of claim 1, And said polycrystalline MgO has a relative density of 3.2 or less.

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