JPH11213887A - Plasma display panel and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: A phosphor layer formed on the inner wall of a discharge display cell of a PDP can be formed from a bottom surface of the discharge display cell to a side surface of a partition wall with a uniform thickness without any coating defects, and with uniform and high accuracy. Provided is a PDP provided with a PDP substrate having a fine pitch, for example, a partition wall capable of realizing a large screen as large as 30 inches or more and having high definition, and a method of manufacturing the same. Discharge display in which a first coating layer formed of a composition for forming a partition formed on a back plate and a second coating layer formed of a composition for forming a phosphor layer are simultaneously plastically deformed and formed. Concave shape 8 formed by phosphor layer 7 provided on inner wall of cell 5
Has a shape along the inner shape of the discharge display cell 5 and at least a thickness 9 of the phosphor layer provided on the side surface of the partition wall 4.
Has a uniform thickness of ± 1 μm or less.

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) and a method for producing the same.

[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 device (LCD), or a flat-panel image display device that has features such as a large screen such as a PDP and the like, and has a feature that it is lightweight, thin, and can be installed anywhere. I am doing it.

[0003] As a flat-panel image display device that meets such demands, a PDP utilizing plasma emission has attracted attention as a light-emitting element of a color image display device for a large screen.

[0004] The PDP is formed in a matrix form facing each other at right angles in minute discharge display cells surrounded by a pair of flat insulating substrates forming a back plate and a front plate and partition walls partitioning the space. And a space in which a dischargeable gas such as a rare gas is hermetically sealed in the space, and a voltage is selectively applied between the opposed electrodes to discharge between the intersections of the electrodes. The generation of plasma causes the phosphor applied to the inside of the discharge display cell to be excited by the ultraviolet light emitted from the plasma to emit light, which is used as a light emitting element of an image display device.

[0005] The application state of the phosphor layer greatly affects the quality of the PDP, such as the light emission luminance and the sharpness of an image. Generally, in a reflection type PDP, the phosphor constituting the discharge display cell is used. As a method of forming the layer, a paste composed of a phosphor layer forming composition is filled between partition walls formed on the back plate by a screen printing method or the like, and the fluidity of the paste, that is, its own weight and surface tension are reduced. It is well known that a phosphor layer is formed uniformly from the side wall of the partition to the bottom of the discharge display cell between the partition walls.

Therefore, in the method for forming a phosphor layer by the screen printing method, the thickness of the phosphor layer can be controlled by the drying strength and leveling property of the binder constituting the paste, matching with the emulsion, and the like. However, since the formation of such a phosphor layer depends exclusively on the fluidity of the paste, bias or bridge of coating of the phosphor paste on the inner wall of the discharge display cell, displacement, insufficient thickness, pores, poor wetting. In addition, as the definition of the PDP advances, it becomes difficult to align the screen plate with the partition walls, and it is easy to cause unevenness in the emission luminance due to color mixing of the phosphor and uneven coating. The thickness of the phosphor layer is also thicker at the bottom of the discharge display cell, thinner at the side wall of the partition, and the thickness of the phosphor layer at the side of the partition is also gradually increased toward the bottom of the discharge display cell. Has Kunar trends, there is a phosphor layer liable to generate applied omission defects in the partition wall side.

In order to solve this problem, as shown in FIG. 3, a paste made of a composition for forming a partition is printed on an insulating substrate 18 by a screen printing method or the like and dried repeatedly to form a partition having a height of about 100 μm. 19, and then printing and drying a photosensitive phosphor paste, and using a photomask having an increased aperture ratio on the photosensitive phosphor layer formed on the photosensitive phosphor layer, not only on the bottom surface of the discharge display cell 20 but also on the side surfaces of the partition walls. A PDP 22 having a pattern 21 has been proposed (see Japanese Patent Application Laid-Open No. 7-212231).

[0008]

However, the PDP 22 in which the phosphor pattern 21 is formed from the side surface to the bottom surface of the partition wall 19 of the discharge display cell 20 using the photosensitive phosphor paste and a photomask having an increased aperture ratio. Thus, although the surface area of light emission increases and the luminance improves, in each of the high-definition discharge display cells 20, the variation in the thickness 23 of the phosphor layer on the side wall of the partition is as large as ± 10 μm or more,
Therefore, in addition to deteriorating the image display quality such as uneven brightness of the PDP, in the above proposal, in order to form the phosphor layer up to the side wall of the partition inside the discharge display cell, the photosensitive phosphor paste is applied between the partitions by a screen printing method. There is a possibility that the phosphor paste may not be accurately positioned and efficiently filled in the narrow gap between the high-definition partition walls.
There has been a problem that it is difficult to eliminate the unevenness of the emission luminance due to the coating defect, the color mixture of the phosphor and the coating unevenness.

[0009]

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 uniformly form a phosphor layer formed on the inner wall of a discharge display cell of a PDP from the bottom of the discharge display cell to the side wall of the partition. A PDP substrate having a high-definition partition wall which can be formed with a small thickness and without coating defects, has a uniform, high-precision and fine pitch, and is extremely easy to make a large screen of, for example, 30 inches or more. An object of the present invention is to provide a PDP and a method for manufacturing the same.

[0010]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned problems, and as a result, have found that a first coating layer made of a composition for forming a partition wall and a phosphor layer on the first coating layer are formed. A back plate constituting an insulating substrate having a second coating layer formed of the composition is placed on a flat support, and the coating layer is simultaneously plastically deformed to form a partition wall molded body and a phosphor layer molded body. By
The obtained PDP substrate was found to be able to uniformly and uniformly cover a phosphor layer having a sufficient thickness up to the side surfaces of the partition walls constituting the discharge display cells, to improve the production yield, and to be able to manufacture efficiently. Invented the invention.

That is, the PDP of the present invention comprises a plurality of inner walls of a plurality of discharge display cells comprising a pair of insulating substrates forming a back plate and a front plate made of ceramics or glass, and a partition partitioning a facing space between the insulating substrates. The concave shape formed by the phosphor layer provided on the PDP substrate has a shape along the inner shape of the discharge display cell, and at least the variation in the thickness of the phosphor layer provided on the side wall of the partition is ± 1 μm or less. Having a light emitting element.

The method of manufacturing a PDP according to the present invention further comprises the steps of: forming a first coating layer made of a composition for forming a partition wall and a second coating layer made of a composition for forming a phosphor layer on a back plate constituting an insulating substrate. The laminates are sequentially laminated, and the laminate is pressed and deformed plastically by using a mold having projections corresponding to the spaces of the discharge display cells. After the partition walls and the phosphor layer are simultaneously molded, the binder is removed, followed by debinding. A PDP substrate is formed by firing and integrating with a back plate.

Further, another method for producing a PDP of the present invention comprises the steps of:
As means for simultaneously plastically deforming the first coating layer comprising the partition wall forming composition and the second coating layer comprising the phosphor layer forming composition, a groove corresponding to a shape obtained by integrating the partition wall and the phosphor layer is used. The phosphor layer is plastically deformed while rotating and pressing the roll-shaped molding die engraved to form a phosphor layer with the phosphor layer adhered to the wall surface. After debinding treatment, it is fired and integrated with the back plate for PDP. It is characterized by forming a substrate.

[0014]

According to the PDP of the present invention and the method of manufacturing the same, the first coating layer formed of the composition for forming a partition formed on the back plate forming the insulating substrate and the second coating layer formed of the composition for forming the phosphor layer are formed. The coating layer is plastically deformed by the mold and the partition and the phosphor layer are molded at the same time, so that the dimensions and shape of the mold are accurately transferred and the phosphor of another color is not mixed and the partition is formed. A phosphor layer having a uniform thickness is formed on the side of the body, so that the variation in the brightness of the discharge display cells can be reduced.

Further, a first coating layer made of a composition for forming a partition wall and a second coating layer made of a composition for forming a phosphor layer are applied on the back plate, and then formed with high precision. The molded mold is pressed against the coating layer to be plastically deformed, so that a partition wall molded body having a phosphor layer having a uniform thickness formed on a wall surface can be molded in a single step. The step of aligning with the partition can be omitted, and the partition and the phosphor layer can be molded and fired simultaneously, so that the process can be significantly shortened and the production yield can be improved, and the PDP substrate having a high precision and fine pitch It is possible to efficiently and inexpensively manufacture a PDP capable of displaying a very high-quality natural image, which is provided with the above.

[0016]

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

FIG. 1 is a cross-sectional 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, and a discharge partitioned by the partition wall 4. The PDP includes a display cell 5, a plurality of electrodes 6 provided in the discharge display cell 5, and a phosphor layer 7 provided on an inner wall of the discharge display cell 5.

In the PDP of the present invention, the phosphor layer 7 formed by plastic deformation on at least the side surface of the partition wall 4 shown in FIG.
The concave shape 8 formed by the phosphor layer 7 provided on the inner wall of the discharge display cell 5 has a shape along the inner shape of the discharge display cell 5 and the thickness 9 of the phosphor layer provided on at least the side surface of the partition wall 4. Have a uniform thickness of ± 1 μm or less.

FIG. 2 shows the steps up to the step of simultaneously forming the partition and the phosphor layer for explaining the method of manufacturing the PDP of the present invention.

As shown in FIG. 2, a method of manufacturing a PDP according to the present invention comprises firstly forming a first coating layer 10 made of a partition-forming composition and a phosphor layer on a back plate 2 forming one of the insulating substrates. A second coating layer 11 composed of a forming composition was applied to a predetermined thickness, and a projection 12 corresponding to a space of a discharge display cell was formed from the surface of the second coating layer 11. The molding die 13 is pressed and plastically deformed, and the molded body 16 of the partition wall and the molded body 17 of the phosphor layer are simultaneously molded in a batch system.

Another method of manufacturing a PDP according to the present invention is to provide a groove 14 corresponding to a shape in which a partition and a phosphor layer are integrated.
Using a roll-shaped forming die 15 engraved with, pressing while rotating against the surface of the second coating layer 11 to cause plastic deformation,
The molding 16 of the partition walls and the molding 17 of the phosphor layer are simultaneously and continuously molded.

The molded body 16 of the partition walls and the molded body 17 of the phosphor layer thus obtained are heated together with the back plate 2 to a predetermined temperature to remove the binder, and then fired to form a PD integrated with the back plate 2.
A substrate for P is formed.

The partition wall forming composition of the present invention may be any glass material which becomes vitreous 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 material. Can be used as a component, the inorganic component and a binder, a solvent,
A mixture with various organic substances such as additives can be appropriately prepared and used according to the molding conditions of the partition walls.

The composition for forming a phosphor layer may be any mixture of a phosphor which is excited by ultraviolet rays and emits light of each color of RGB and a glass material which becomes vitreous after firing and binds the phosphor. For example, a mixture of a low-melting glass powder and a phosphor powder composed of a metal oxide can be used as an inorganic component, and a mixture of the inorganic component and a binder, a solvent, and an organic substance such as various additives can be appropriately molded under molding conditions. Can be prepared and used according to

It is sufficient that the first coating layer of the composition for forming a partition wall and the second coating layer of the composition for forming a phosphor layer finally have plastic deformability. It is also possible to form a coating layer with the composition itself having the above, or to impart plastic deformation to the coating layer after forming each of the coating layers.

As an organic substance suitable for the composition having plastic deformability, the binder may be, for example, acrylic or
A butyral-based thermoplastic binder or a reactive curable resin such as an ultraviolet curable resin, a photocurable resin, or a thermosetting resin can be used. On the other hand, as a method of imparting plastic deformation to the coating layer formed on the back plate, in addition to previously adding the organic material exhibiting plastic deformation to each composition, after forming the coating layer on the back plate Post-treatments such as drying, gelling, etc. can be applied to impart plastic deformability.

As a method for forming each of the coating layers, a known roll coater method, doctor blade method, or the like can be applied, but the doctor blade method is preferable in consideration of mass productivity.

In the molding die and the roll-shaped molding die used here, since the address electrodes are required to be aligned between the partition walls over the entire back plate, the dimensional accuracy between the partition walls is within ± 1 μm. Since this has been achieved, the variation in the thickness of the phosphor layer of the present invention is within ± 1 μm over the entire surface of the PDP, and as a result, the variation in the luminance of the PDP is within 1% within the panel surface. Become.

The molding die may be made of metal, resin, rubber or the like. Further, a composite molding die using a resin or rubber member only on the surface of a metal base material may be used. In addition, the surface of the mold has no problem even if it is subjected to a surface treatment or the like in order to improve releasability or abrasion resistance. It is sufficient that irregularities having a shape corresponding to the partition walls in which the body layer is integrated are formed on the surface thereof. In particular, grooves having the above-described shape are carved on the roll-shaped surface, and the partition wall forming composition and the phosphor are rotated while rotating. A roll-shaped mold for plastically deforming the composition for forming a layer is most suitable in terms of accuracy and mass productivity.

On the other hand, as the insulating substrate used for the back plate and the front plate of the present invention, a transparent glass substrate such as soda lime glass, low soda glass, lead alkali silicate glass and borosilicate glass can be used. High strain point low 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.

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.

The front plate is sealed to a PDP substrate having the phosphor layer obtained on the inner wall of the discharge display cell, and a discharge gas containing Xe, He-Xe, Ne-Xe or the like as a main component is discharged.
The PDP is completed by hermetically sealing at 0 to 600 Torr.

[0034]

Next, the PDP of the present invention and the method for producing the same were evaluated as follows. First, 4 mm 2mm
On a back plate made of 0-inch size soda lime glass, electrodes having a width of 90 μm are formed in a stripe shape using an electrode paste containing Ag as a main component by 220 μm by a thick film printing method.
A back plate with electrodes was produced by forming the entire surface at a pitch and baking.

On the other hand, the width is 50 μm, the height is 150 μm,
A roll-shaped metal partition wall forming die having a large number of partition-shaped concave grooves formed by integrating phosphor layers having a pitch of 220 μm was prepared.

Next, on the back plate with electrodes, a partition-forming composition comprising a low-melting glass powder, a butyral resin, a solvent and a dispersant is uniformly applied by a roll coater to form a first coating layer. Further, a phosphor layer-forming composition comprising a phosphor powder, a low-melting glass powder, a butyral resin, a solvent, and a dispersant is uniformly applied on the first coating layer by a roll coater to form a second coating. A layer was formed.

The above-mentioned composition for forming a phosphor layer is made of RGB.
Are prepared, and they are respectively formed with a pitch of 220 μm and a width of 180 μm and a thickness of 20 μm so as to be adjacent to each other in parallel in a stripe shape.

Thereafter, the back plate on which the coating layer is formed is placed on a flat metal support, and the roll-shaped metal mold is pressed against the coating layer on the back plate while rotating. After simultaneously plastically deforming the first coating layer made of the composition for forming a partition wall and the second coating layer made of the composition for forming a phosphor layer, the roll-shaped forming mold is released and the partition wall is formed on the back plate. A molded body of the phosphor layer formed on the molded body and the bottom surface between the molded body and the partition wall side was formed.

Next, the support was removed, the molded body was adhered to the back plate, and the binder was maintained at a predetermined temperature to remove the binder. Then, the firing atmosphere was appropriately changed according to the main components of each material, and the temperature was set at 550 to 580 ° C. It was baked for 10 minutes to produce a PDP substrate for evaluation integrated with the back plate.

With respect to the PDP for evaluation thus obtained, the cross section was observed by SEM, the shapes of the partition walls and the phosphor layer were observed, and the thickness of the phosphor layer on the side face of the partition wall was measured.

As a result, the concave portion formed by the phosphor layer has a very smooth surface and is formed in a shape corresponding to the inner shape of the discharge display cell. The width of the partition wall including the phosphor layer is 45 μm. From the cross-sectional shape, the thickness of the phosphor layer from the top of the partition to the bottom on the back plate side is 15 μm ± 1 μm
And was formed uniformly.

The present invention is not limited to the above-described embodiment.

[0043]

According to the PDP and the method of manufacturing the same of the present invention, the partition walls and the phosphor layer are simultaneously formed by a molding die, and at least the variation in the thickness of the phosphor layer on the side wall of the partition is as high as ± 1 μm or less. Since the accuracy is obtained, it is possible to form a uniform and accurate phosphor layer, and a different color phosphor is applied to the adjacent discharge display cells, so that there is no coating defect that causes a color mixture, and at the same time, the fluorescent light is applied. As a result of the extremely high distance between the body layer surfaces, the variation in the distance between the openings of the discharge display cells becomes 1% or less, and a PDP capable of displaying a very high-quality natural image with extremely small luminance variation can be formed. .

On the other hand, there is no need for a step of aligning with the partition which requires precision as in the conventional thick film printing method for forming the phosphor layer. PDPs that can greatly reduce the process time, improve manufacturing yield, increase productivity, and have a high-precision, fine-pitch, large-screen screen of, for example, 30 inches or more, with high precision. Can be provided at a low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a PDP of the present invention.

FIG. 2 is a view illustrating a process up to a stage where a partition wall and a phosphor layer are simultaneously molded for explaining a method of manufacturing a PDP of the present invention.

FIG. 3 is a sectional view showing a conventional PDP.

[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 layer 8 Concave shape 9 Phosphor layer thickness 10 The 1st coating layer which consists of composition for partition formation 11 Composition for phosphor layer formation Second covering layer 12 made of a material 12 Convex portion 13 Mold 14 Groove 15 Roll-shaped mold 16 Partition wall molded body 17 Phosphor layer molded body

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Nishioka, 1-4, Yamashita-cho, Kokubu-shi, Kagoshima Inside the Kyocera Research Institute (72) Inventor, Shinichi Handa 10-1, Kawai, Gamo-cho, Gamo-gun, Shiga Prefecture (72) Inventor, Hironori Tashiro, 1-10, Kawai, Gamo-cho, Gamo-gun, Shiga Prefecture, Japan

Claims (3)

[Claims] 1. A plurality of discharge display cells are constituted by a pair of insulating substrates forming a back plate and a front plate made of ceramics or glass, and a partition partitioning a facing space between the insulating substrates. A plurality of electrodes are provided and hermetically sealed with a discharge gas, a voltage is selectively applied between the electrodes to generate plasma, and a phosphor provided on the inner wall of the discharge display cell emits light, and a light emitting element of the image display device. A plasma display panel, wherein the recessed shape formed by the phosphor layer provided on the inner wall of the discharge display cell has a shape along the inner shape of the discharge display cell, and at least the thickness of the phosphor layer provided on the side wall of the partition. A plasma display panel characterized in that the variation in height is ± 1 μm or less. 2. A first coating layer comprising a composition for forming a partition wall is formed on a back plate constituting an insulating substrate by adhesion, and further comprising a composition for forming a phosphor layer on the first coating layer. After the formation of the second coating layer, a mold having a projection corresponding to the space of the discharge display cell is pressed against the coating layer to plastically deform the first and second coating layers, After forming the partition wall and the phosphor layer at the same time, heating the formed body to remove the binder, and then firing and integrating with the back plate to form a plasma display panel substrate having the phosphor layer on the inner wall of the discharge display cell. A method for manufacturing a plasma display panel, comprising: 3. A first coating layer comprising a composition for forming a partition wall is formed on a back plate constituting an insulating substrate, and further comprising a composition for forming a phosphor layer on the first coating layer. After forming the second coating layer, the first and second roll-shaped molds each having a groove corresponding to a shape obtained by integrating the partition wall and the phosphor layer are pressed while rotatingly pressing the coating layer. After forming the partition wall and the phosphor layer simultaneously by plastically deforming the coating layer, the formed body is heated and debindered, and then fired and integrated with the back plate to have the phosphor layer on the inner wall of the discharge display cell. A method for manufacturing a plasma display panel, comprising forming a panel substrate.