JPH11135026A - Plasma display panel - Google Patents

Abstract

(57) [Problem] To reduce pores of a partition wall constituting a discharge display cell,
The strength of the fired partition wall is high, chipping or the like is unlikely to occur during the manufacturing process, the partition wall capable of suppressing the deterioration of the luminance immediately after light emission can be formed inexpensively and efficiently, and has a high precision and fine pitch. Provided is a PDP having a partition wall with high definition. A phosphor is formed on the inner wall of a discharge display cell by selectively applying a voltage between electrodes to generate plasma.
Of the partition wall 4 of the discharge display cell 5 formed by the partition wall 4 that partitions the space between the pair of insulating substrates forming the back plate 2 and the front plate 3 that hermetically seals a discharge gas to be used as a light emitting element of the image display device. The porosity is less than 20%, and the porosity of the partition walls is more preferably less than 10%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (hereinafter, referred to as a "light-emitting element") used in a high-precision, inexpensive, lightweight, thin, large-screen color image display device or the like.
PDP).

[0002]

2. Description of the Related Art CRTs, which have been widely used as image display devices, have a disadvantage that they have a large volume and weight and require a high voltage.
Light emitting diode (LE) as information interface
D), a liquid crystal display element (LCD), or a flat-panel image display device having features such as a large screen such as a PDP, a high-quality image, a thin and light-weight, and any installation location are developed. I am doing it.

As a flat panel image display device that meets such demands, PDPs utilizing plasma emission have attracted much attention as light-emitting elements of color image display devices for large screens.

In such a PDP, a pair of flat insulating substrates forming a back plate and a front plate, and opposing electrode groups are provided in a minute discharge display cell surrounded by a partition partitioning the space. It has a structure in which a dischargeable gas such as a rare gas is hermetically sealed in a space, and a voltage is selectively applied between the opposing electrodes to generate plasma by discharge, and ultraviolet light emitted from the plasma is generated. The phosphor formed in the discharge display cell emits light and is used as a light emitting element of an image display device.

In general, during the process of manufacturing the PDP, as a method of manufacturing a partition constituting a discharge display cell, a paste made of a composition for forming a partition is repeatedly printed and dried in a partition pattern by a screen printing method on a back plate. A method of forming a partition shape by stacking up to a required height is well known.

However, in the screen printing method, since the thickness of a film that can be formed by one printing is about 10 μm, about 100 to 2
Since a partition wall of a discharge display cell requiring a height of about 00 μm is formed, it is necessary to repeat the printing and drying steps many times to laminate.

Therefore, the number of steps becomes extremely large, and the partition walls are easily deformed due to misalignment of the printing plate during printing, and good dimensional accuracy cannot be obtained due to the extension of the printing plate and the like. There is a limit in forming at a fine pitch, so that the demand for high definition as a PDP cannot be satisfied, and furthermore, the yield is very poor because it is necessary to print with high accuracy for each lamination. was there.

Therefore, as a method of solving such a problem, a partition wall material is formed in a layer on a back plate with a required thickness,
A resist layer is applied to the layer of the partition wall material, a resist mask is formed by a photolithography method, and unnecessary portions other than the partition walls are removed by sandblasting through the resist mask to form a partition wall having a desired shape. (See Japanese Patent Application Laid-Open No. 9-29638).

[0009]

However, in the sand blasting method, a repetition step such as a screen printing method is not required, and the bottom of the partition is not disturbed and the bottom of the partition is not disturbed. Although it is possible to form a partition having a high cross-sectional shape, it is necessary to grind and remove the layer made of the partition material in a porous state without increasing the density in order to improve the free-cutting property. There was a problem that the partition wall molded body had low strength and was easily chipped.

In addition, the compact of the partition wall does not sufficiently advance even after firing, and remains as pores in the partition wall.
During the manufacturing process of the DP, the partition walls are easily chipped, and the partition walls where the pores remain have a problem that the luminance is deteriorated immediately after light emission due to the adsorbed trace components and the like.

In addition, since the photolithography technique is used to form the resist mask, the apparatus is expensive and the manufacturing process is complicated. In addition, the grinding force is reduced due to wear deterioration of the abrasive, and the grinding process is stabilized due to aging. Unsolved problems are that it is difficult to form a uniform high-definition partition wall, and most of the partition wall material other than the part where the partition wall is formed must be removed in large quantities as grinding dust, which increases the manufacturing cost. Met.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and an object of the present invention is to reduce the pores of the partition walls constituting the discharge display cell of the PDP so that the strength of the partition wall molded body and the partition fired body can be reduced. High, hardly cause chipping or the like during the manufacturing process, and obtain a partition capable of suppressing the deterioration of luminance immediately after light emission, can form the partition inexpensively and efficiently, have a fine pitch with high precision, for example, 30 inches or more It is an object of the present invention to provide a PDP having a large screen and a partition wall with high definition.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above-mentioned problems, and as a result, it has been found that, by reducing the number of pores by further densifying the fired and integrated partition on the back plate constituting the insulating substrate, the light emission immediately after light emission is achieved. It has been found that a PDP having high-precision and high-strength partition walls composed of fine pitches can be obtained inexpensively and efficiently, thereby leading to the present invention.

That is, in the PDP of the present invention, a plasma is generated by selectively applying a voltage between the electrodes to generate a plasma, and a phosphor formed on the inner wall of the discharge display cell emits light to emit light as a light emitting element of an image display device. Wherein the porosity of the partition wall of the discharge display cell formed by the partition partitioning the space between the pair of insulating substrates forming the back plate and the front plate hermetically sealed therein is less than 20%, In particular, it is more preferable that the porosity of the partition wall is less than 10%.

[0015]

According to the PDP of the present invention, since the porosity of the partition walls constituting the PDP is small and the fired body is dense, the strength of the partition walls is improved and the amount of trace components adsorbed on the partition walls is reduced, so that the PDP is reduced. PDP substrate with high-precision, low-cost partition walls having a fine pitch that acts to reduce the risk of the trace components being mixed into the rare gas during operation and suppresses deterioration of luminance immediately after light emission Is efficiently obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a PDP of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially broken perspective view showing a PDP of the present invention.

In FIG. 1, reference numeral 1 denotes a partition wall 4 provided in parallel with a space between a back plate 2 and a front plate 3 facing each other, a discharge display cell 5 partitioned by the partition wall 4, and a discharge display cell 5 provided in the discharge display cell 5. The PDP includes a plurality of electrodes 6 and a phosphor 7 provided on an inner wall of the discharge display cell 5.

When the porosity of the partition walls constituting the PDP of the present invention is 20% or more, the obtained partition walls have low strength and are liable to be chipped. Less effective.

Therefore, the porosity of the partition is limited to less than 20%, and in particular, the porosity is preferably less than 10% from the viewpoint of suppressing the deterioration of luminance immediately after light emission.

Here, the porosity of the partition wall is defined by the following equation.

[0022]

(Equation 1)

Next, FIG. 2 is a perspective view showing a process up to a partition forming step for explaining an example of a method of manufacturing a PDP of the present invention.

As shown in FIG. 2, the PDP of the present invention presses a coating layer 8 made of a composition for forming a partition formed on a surface of a back plate 2 with a predetermined thickness by a partition forming die 9. The coating layer 8 is pressurized and plastically deformed.
Using a roll-shaped mold 12 in which a groove 11 for partition wall formation is engraved, the roll-shaped mold 12 is pressed against the coating layer 8 while rotating, and pressed to form a groove 11 for partition wall formation. By continuously forming the partition wall molded body 10 by plastically deforming it, the partition wall molded body 10 having a high density can be obtained.

The partition wall molded body 10 thus obtained is heated to a predetermined temperature together with the back plate 2 to remove the binder, and then fired to form a PDP having the partition walls 4 integrated with the back plate 2.
The substrate 13 for use is obtained.

The composition for forming a partition wall may be any glass material which becomes glassy after firing and can maintain airtightness. For example, a mixture of a low melting point glass powder and an oxide ceramic powder may be used as an inorganic component. A mixture of the inorganic component and an organic substance such as a binder, a solvent, and various additives can be appropriately prepared and used according to the molding conditions of the partition wall.

It is sufficient that the coating layer of the composition for forming a partition finally has plastic deformability. For example, the coating layer may be formed of the composition for forming a partition having plastic deformation, or a partition may be formed. After forming the coating layer of the molding composition,
It is also possible to impart plastic deformation to the coating layer.

The organic material suitable for the partition wall forming composition having plastic deformability includes, for example, a binder such as
An acrylic or butyral-based thermoplastic binder or a reaction-curable resin such as an ultraviolet-curable resin, a photo-curable resin, or a thermosetting resin can be used.

On the other hand, the method for imparting plastic deformation to the coating layer of the partition wall forming composition formed on the back plate is as follows, except that the organic substance exhibiting plastic deformation is previously added to the partition wall forming composition. First, after forming a coating layer on the back plate, post-treatments such as drying and gelling may be performed to impart plastic deformability.

On the other hand, as means for forming the partition wall forming composition in a layered form, the partition wall forming composition is applied on a back plate by a roll coater method, a doctor blade method, a screen printing method, a gravure printing method or the like. The doctor blade method is preferable in consideration of mass productivity.

The partition mold may be made of metal, resin, rubber, or the like. Needless to say, a composite partition using a resin or rubber member only on the surface of a metal base material is used. It is also possible to use a molding die, and there is no problem even if a surface treatment or the like is performed on the surface of the partition molding die in order to improve the releasability or the wear resistance.

As the shape of the partition wall mold, a plate-shaped or roll-shaped mold having a plurality of grooves corresponding to the shape of the partition wall can be used. In particular, it is easy to manufacture the partition wall mold. From the viewpoint of the dimensional accuracy and mass productivity of the molded body,
A roll-shaped partition mold is optimal.

The molded partition wall thus obtained is heated to a predetermined temperature to remove the binder, and then subjected to a firing step.
A PDP substrate can be obtained by being integrated with the back plate.

Thereafter, a phosphor is applied to each discharge display cell via a mask pattern and baked. Then, the back plate and the front plate are sealed, and Xe, He-Xe, Ne-Xe or the like is mainly used. A discharge gas as a component is hermetically sealed at 10 to 600 Torr to complete a PDP.

As the insulating substrate used for the back plate and the front plate, a transparent glass substrate such as soda lime glass, low soda glass, lead alkali silicate glass, and borosilicate glass can be used. Spotted soda glass is preferred.

In addition, silver (A)
g), a conductive metal such as nickel (Ni), aluminum (Al), or an alloy thereof, or a conductive paste obtained by mixing the conductive metal or its alloy with a small amount of glass.

On the other hand, a transparent electrode on which indium oxide, tin oxide or the like is deposited is formed on a front plate which is an insulating substrate on the display surface side.

[0038]

Next, the PDP of the present invention was evaluated as follows.

(Embodiment 1) First, an electrode having a width of 50 μm was stripped on a back plate made of 40-inch soda lime glass having a thickness of 2 mm using an electrode paste containing Ag as a main component by a thick film printing method. A back plate provided with electrodes was prepared by forming the entire surface at a pitch of 220 μm and baking.

On the other hand, the width is 40 μm, the height is 200 μm,
A roll-shaped metal partition wall forming die having a large number of partition-shaped concave grooves corresponding to a pitch of 220 μm was prepared.

Next, a partition wall forming composition comprising a low melting glass powder, a butyral resin, a solvent and a dispersant is uniformly applied on a back plate having the electrodes by a doctor blade to form a dense coating layer. Formed.

Thereafter, the back plate on which the coating layer was formed was placed on a flat support made of metal, and the roll-shaped partition mold was pressed against the back plate on which the coating layer was formed. Then, after the coating layer made of the partition wall forming composition was plastically deformed to give a partition wall shape, the partition wall forming mold was released to form a partition wall formed body on the back plate.

Then, after the above-mentioned partition wall molded body and the back plate adhered to each other are kept at a predetermined temperature and subjected to a binder removal treatment,
The firing atmosphere is appropriately changed according to the main components of each material.
The resultant was baked at 580 ° C. for 10 minutes to produce a PDP substrate having partition walls integrated with the back plate.

A phosphor is applied to each of the thus obtained discharge display cells of the PDP substrate through a mask pattern, and then the phosphor is baked. Then, the back plate and the front plate are sealed, and Ne- A discharge gas containing Xe as a main component was hermetically sealed to prepare a PDP for evaluation.

First, using the PDP for evaluation, a voltage of 200 V was applied between the electrodes of the back plate and the front plate to cause the discharge display cell to emit light, and the luminance at the start of light emission and after 30 minutes had elapsed was measured. Then, the degree of the deterioration was evaluated.

The porosity of the partition is determined by cutting the PDP for evaluation and polishing the cross section of the partition, observing the cross section of the partition with a scanning electron microscope (SEM), and analyzing the cross section of the partition by image processing. , Identifying the pores and the rest,
The total area occupied by pores in the partition wall cross section and the partition wall cross-sectional area were obtained, and the porosity of the partition wall was calculated by the following equation.

[0047]

(Equation 1)

As a result, the porosity of the partition wall was 8%, and the luminance at the start of light emission was 156 cd / m ² , but the luminance after 30 minutes passed was 152 cd / m ^2, which was extremely low immediately after the light emission. It was small, and no defects such as cracks and chips were found in the partition walls.

Example 2 A composition for forming a partition wall was uniformly applied on the back plate in the same manner as in Example 1, and then subjected to a drying treatment at a temperature of 80 ° C. for 1 hour. A PDP for evaluation was prepared in the same manner as in Example 1.

The PDP for evaluation thus obtained was evaluated in the same manner as in Example 1. As a result, the porosity of the partition walls was 7%.
The luminance at the start of light emission is 158 cd / m ² , and the luminance after 30 minutes is 155 cd / m ^2, which means that there is almost no deterioration in luminance immediately after light emission. No defects such as chipping were observed.

(Example 3) On the back plate having the electrodes of Example 1, a mold was prepared in which the surface of the roll-shaped metal partition wall mold of Example 1 was subjected to a Teflon coating treatment. A PDP for evaluation was produced in the same manner as in Example 1.

The PDP for evaluation thus obtained was evaluated in the same manner as in Example 1. As a result, the porosity of the partition walls was 9%.
The luminance at the start of light emission is 155 cd / m ² , and the luminance after 30 minutes is 150 cd / m ² , which is also extremely small immediately after light emission, and the partition walls have defects such as cracks and chips. Was not found.

(Example 4) On the back plate having the electrodes of Example 1, a plate-shaped metal partition wall mold was prepared in place of the roll-shaped metal partition wall mold of Example 1, and the partition walls were sequentially formed. A PDP for evaluation was produced in the same manner as in Example 1 except that a molding die was pressed against the coating layer and plastically deformed to form a molded partition wall.

The PDP for evaluation thus obtained was evaluated in the same manner as in Example 1. As a result, the porosity of the partition walls was 15%, and the luminance at the start of light emission was 154 cd / m ² , whereas the porosity was 30 cd / m ^2. The luminance after a lapse of minutes was 145 cd / m ^2, and the deterioration of the luminance immediately after the light emission was small, and no defects such as cracks and chips were found in the partition walls.

(Comparative Example) After a layer of the composition for forming a partition was formed on the back plate having the electrodes of Example 1, a resist film was formed on the layer, and portions other than the portions corresponding to the partition were exposed and developed. A blast mask was prepared and subjected to sand blasting, and parts other than the partition were ground and removed. Then, the blast mask was removed to obtain a molded partition, and a PDP for evaluation was prepared in the same manner as in Example 1. .

The PDP for evaluation thus obtained was evaluated in the same manner as in Example 1. As a result, the porosity of the partition wall was as large as 30%, and the luminance at the start of light emission was 155 cd / m ² , whereas The luminance after a lapse of one minute was as low as 110 cd / m ^2, and it was confirmed that the deterioration of the luminance immediately after the light emission was extremely large, and defects such as cracks and chips were also found on the partition walls.

[0057]

According to the PDP of the present invention, since the porosity of the partition walls constituting the PDP is as low as less than 20%,
Since the strength of the fired partition walls is high and defects such as cracks and chips do not occur during the manufacturing process, the amount of trace components adsorbed on the partition walls is reduced. The mixing of components is reduced, and the deterioration of luminance immediately after light emission is suppressed.

Further, since the partition walls can be formed by plastically deforming the partition wall forming composition in a continuous pressing step using a high-definition partition wall forming mold, the production yield is improved, and the productivity is increased. PDP having high-definition partition walls with a large screen of, for example, 30 inches or more, which can form partition walls having a fine pitch with high precision at low cost and efficiently.
Is obtained.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing a PDP of the present invention.

FIG. 2 is a perspective view showing a process up to a partition forming step for explaining an example of a method of manufacturing a PDP of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PDP 2 Back plate 3 Front plate 4 Partition wall 5 Discharge display cell 6 Electrode 7 Phosphor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyohiro Sakasegawa 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima

Claims (2)

[Claims] A pair of insulating substrates forming a back plate and a front plate;
A plurality of discharge display cells are constituted by partition walls that partition the space between the insulating substrates, a plurality of electrodes are provided in the discharge display cells, a discharge gas is hermetically sealed, and a voltage is selectively applied between the electrodes. A plasma display panel which generates plasma and emits light from a phosphor formed on the inner wall of the discharge display cell to serve as a light emitting element of an image display device, wherein the porosity of the partition is less than 20%. Plasma display panel. 2. The plasma display panel according to claim 1, wherein the porosity of the partition is less than 10%.