WO2008032355A1

WO2008032355A1 - Plasma display panel and method of forming phosphor layer thereof

Info

Publication number: WO2008032355A1
Application number: PCT/JP2006/317985
Authority: WO
Inventors: Seiki Kurogi; Nobuyuki Hori
Original assignee: Hitachi Plasma Display Limited
Priority date: 2006-09-11
Filing date: 2006-09-11
Publication date: 2008-03-20
Also published as: JPWO2008032355A1

Abstract

The absolute amount of moisture trapped in the panel is reduced by forming a red or green phosphor layer as an underlayer of blue phosphor layer to thereby while ensuring the intensity of light emission from the blue phosphor layer, reduce the amount of blue phosphor material used. There is provided a plasma display panel (PDP) comprising an electric discharge space made between a pair of substrata and, disposed in matrix form therein, a multiplicity of cell sets each composed of a cell furnished with red phosphor layer (28R), a cell furnished with green phosphor layer (28G) and a cell furnished with blue phosphor layer (28B), wherein phosphor layer of other color (31R) is disposed as a reflective layer under the blue phosphor layer (28B).

Description

Plasma display panel and phosphor layer forming method thereof

Technical field

The present invention relates to a plasma display panel (hereinafter referred to as PDP) and a method for forming a phosphor layer thereof. More specifically, the present invention has a red phosphor layer, a green phosphor layer, and a blue phosphor layer. The present invention relates to a PDP that performs full-color display with phosphors and a method for forming the phosphor layer. In recent years, PDPs can be displayed on television due to the development of colorization, and are attracting attention as the most promising candidates for large flat panel display realization devices.

Background art

[0002] As a conventional PDP, an AC-driven three-electrode surface discharge type PDP is known! This PDP is provided with a large number of display electrodes capable of surface discharge in the horizontal direction on the inner surface of one substrate (for example, the front substrate), and an address for selecting light emitting cells on the inner surface of the other substrate (for example, the rear substrate). A large number of electrodes are provided in the direction intersecting the display electrode, and the intersection between the display electrode and the address electrode is formed as one cell (unit light emitting region). One pixel consists of three sub-cells: a red (R) cell with a red phosphor layer, a green (G) cell with a green phosphor layer, and a blue (B) cell with a blue phosphor layer. Consists of pixels. These phosphor layers are generally formed on the substrate on the back side.

[0003] The display electrodes on the front substrate and the address electrodes on the rear substrate are each covered with a dielectric layer, and the dielectric layer of the front substrate is covered with a protective film made of MgO.

The PDP is manufactured by sealing the periphery with the front-side substrate and the back-side substrate made in this manner facing each other, and then enclosing a discharge gas inside.

[0004] In this PDP, light emission of a desired color is obtained by combining fluorescence generated from phosphor layers of three colors of red, blue, and green.

As the red phosphor material, (Y, Gd) BO: Eu, Y 2 O: Eu, or the like is used. Green

3 2 3

As the color phosphor material, Zn SiO: Mn, Zn GeO: Mn, or the like is used. Blue

2 4 2 2

As phosphor materials, BaMgAl 2 O 3: Eu, BaSrMgAl 2 O 3: Eu, etc. are often used.

10 17 10 17

ing. Of these, blue phosphor materials such as BaMgAl 2 O 3: Eu and BaSrMgAl 2 O 3: Eu are red.

10 17 10 17

Compared with the phosphor material and the green phosphor material, the crystal structure has a layered structure, and moisture present in the air is selectively adsorbed on the surface of the Ba—O layer of the phosphor. End up. Therefore, moisture adhering to the blue phosphor material is taken into the panel (see Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2003-213258

Disclosure of the invention

Problems to be solved by the invention

[0006] Moisture taken into the panel reacts with phosphors by discharge or reacts with MgO formed as a protective film, thereby causing deterioration of panel brightness, chromaticity change, or driving margin. Problems such as a decrease and an increase in discharge voltage may occur.

[0007] The present invention has been made in view of such circumstances, and a red or green phosphor layer is formed below the blue phosphor layer, while ensuring the amount of light emitted from the blue phosphor layer. By reducing the amount of blue phosphor material used, the absolute amount of moisture taken into the panel is reduced.

Means for solving the problem

The present invention relates to a cell in which a red phosphor layer is formed, a cell in which a green phosphor layer is formed, and a cell in which a blue phosphor layer is formed in a discharge space formed between a pair of substrates. Is a plasma display panel in which a large number of cells are arranged in a matrix, and a phosphor layer of another color is formed as a reflective layer under the blue phosphor layer. It is a plasma display panel.

The invention's effect

According to the present invention, it is possible to reduce impurity gas such as moisture in the panel at a low cost without reducing the amount of light emitted from the blue phosphor layer and without increasing the number of steps. Brief description of

FIG. 1 is an explanatory diagram showing a configuration of a PDP of the present invention. 圆 2] An explanatory view showing a phosphor layer of the PDP of the present invention.

圆 3] An explanatory view showing a phosphor layer of a comparative example.

FIG. 4 is an explanatory view showing the manufacturing process of the rear panel assembly of the present invention in the order of steps.

[0011] 10 PDP

11 Front side board

12 Transparent electrode

13 Bus electrode

17, 24 Dielectric layer

18 Protective film

21 Back side board

28R, 28G, 28B, 31R phosphor layer

29 Bulkhead

30 Discharge space

A Address electrode

L Display line

X, Y display electrode

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, as a pair of substrates, glass, quartz, ceramics and other substrates, and desired components such as electrodes, insulating films, dielectric layers and protective films on these substrates. Is included.

[0013] Display electrodes may be arranged in a certain direction on the substrates on the front side of the pair of substrates. Further, address electrodes may be arranged on the substrate on the back side in a direction intersecting with the display electrodes.

The display electrode and the address electrode can be formed using various materials and methods known in the art. Examples of materials used for the electrode include ITO and SnO.

2 Clear conductive materials and metallic conductive materials such as Ag, Au, Al, Cu, Cr. As a method for forming the electrode, various methods known in the art can be applied. For example, it may be formed using a thick film forming technique such as printing, or may be formed using a thin film forming technique such as physical deposition or chemical deposition. Examples of the thick film forming technique include a screen printing method. Among thin film formation techniques, examples of physical deposition methods include vapor deposition and sputtering. Examples of the chemical deposition method include a thermal CVD method, a photo-CVD method, and some! /, A plasma CVD method.

[0015] The red phosphor layer, the green phosphor layer, or the blue phosphor layer is formed by releasing a phosphor paste containing red, green, or blue phosphor powder, a binder resin, and a solvent in a groove-like shape between the partition walls. It can be formed by applying it into the electric space by screen printing or a method using a dispenser, repeating this for each color, and then baking. In addition, the phosphor layer can be formed by a photolithography technique using a sheet-like phosphor layer material (so-called green sheet) containing phosphor powder, a photosensitive material, and a binder resin. In this case, a phosphor sheet of each color is formed between the corresponding barrier ribs by applying a sheet of a desired color to the entire display area on the substrate, exposing and developing, and repeating this for each color. It is out.

[0016] The red phosphor material used for the red phosphor paste includes (Y, Gd) BO: Eu and Y 2 O

3 2

: Eu or the like can be used. As a green phosphor material used for green phosphor paste

Three

Zn SiO: Mn, Zn GeO: Mn, or the like can be used. Blue phosphor paste

2 4 2 2

Examples of blue phosphor materials used in the present invention include BaMgAl 2 O 3 Eu and BaSrMgAl 2 O 3 Eu.

10 17 10 17 Can be used.

In the present invention, the other color phosphor layer formed as the reflection layer is preferably a red phosphor layer or a green phosphor layer. In this case, it is desirable that the total thickness of the blue phosphor layer and the underlying phosphor layer is approximately the same as that of the red phosphor layer or the green phosphor layer. The blue phosphor material contained in the blue phosphor layer is BaMgAl 2 O 3:

10 17

Eu may be used. BaSrMgAl 2 O 3: Eu may be used.

10 17

The present invention also provides a cell in which a red phosphor layer is formed, a cell in which a green phosphor layer is formed, and a blue phosphor layer in a discharge space formed between a pair of substrates. Of a plasma display panel in which a large number of cells are arranged in a matrix. A phosphor layer forming method comprising: applying a phosphor paste of each color to a region where each color phosphor layer is to be formed, drying the substrate, and firing the phosphor paste to form a phosphor layer. When applying red phosphor layer to the area where the red phosphor layer is to be formed, or when applying green phosphor paste to the area where the green phosphor layer is to be formed, either Display panel comprising a step of applying the same phosphor paste to the blue phosphor layer formation planned area and drying, and then applying the blue phosphor paste to the blue phosphor layer formation planned area This is a phosphor layer forming method.

Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings. It should be noted that the present invention can be variously modified without being limited thereto.

[0020] Fig. 1 (a) and Fig. 1 (b) are explanatory diagrams showing the configuration of the PDP of the present invention. Fig. 1 (a) is an overall view, and Fig. 1 (b) is a partially exploded perspective view. This PDP is an AC-driven 3-electrode surface discharge PDP for color display.

The PDP 10 includes a front substrate 11 and a rear substrate 21. As the substrate 11 on the front side and the substrate 21 on the back side, a glass substrate, a quartz substrate, a ceramic substrate, or the like can be used.

[0022] Display electrodes X and Y are arranged at equal intervals in the horizontal direction on the inner side surface of the substrate 11 on the front side. The display line L is entirely between the adjacent display electrode X and display electrode Y. Each display electrode X, Y consists of a wide transparent electrode 12 such as ITO, SnO, etc., for example, Ag, Au, A

2

1, Cu, Cr, and their laminated bodies (for example, a laminated structure of CrZCuZCr) are composed of a narrow bus electrode 13 made of metal that also has equal force. For display electrodes X and Y, the desired number and thickness of Ag and Au can be obtained by using a thick film formation technology such as screen printing, and the others using thin film formation technology such as vapor deposition and sputtering, and etching technology. It can be formed with length, width and spacing.

[0023] In this PDP, a display electrode X and a display electrode Y are arranged at equal intervals, and a display line L is formed between adjacent display electrodes X and Y, which is a so-called ALIS structure PDP. However, the present invention can also be applied to a PDP having a structure in which the pair of display electrodes X and Y are arranged with a gap (non-discharge gap) where no discharge occurs. A dielectric layer 17 is formed on the display electrodes X and Y so as to cover the display electrodes X and Υ. The dielectric layer 17 is formed by applying a low-melting glass paste to the front substrate 11 by screen printing and baking. The dielectric layer 17 is made of SiO by plasma CVD.

2 You may form by forming a film.

A protective film 18 is formed on the dielectric layer 17 to protect the dielectric layer 17 from damage caused by ion collision caused by discharge during display. This protective film is made of MgO. The protective film can be formed by a thin film forming process known in the art, such as electron beam evaporation or sputtering.

A plurality of address electrodes A are formed on the inner side surface of the substrate 21 on the back side in a direction intersecting the display electrodes X and Y in plan view, and the dielectric layer 24 covers the address electrodes A. Is formed. The address electrode A generates an address discharge for selecting a light emitting cell at an intersection with one display electrode Y, and is formed of a three-layer structure of CrZCuZCr. In addition, the address electrode A can be formed of, for example, Ag, Au, Al, Cu, Cr, or the like. As with the display electrodes X and Y, the address electrode A also uses a thick film formation technique such as screen printing for Ag and Au, and a thin film formation technique such as vapor deposition and sputtering and an etching technique for the other. Thus, it can be formed with a desired number, thickness, width and interval. The dielectric layer 24 can be formed using the same material and the same method as the dielectric layer 17.

On the dielectric layer 24 between the adjacent address electrodes A and A, a plurality of stripe-shaped partition walls 29 are formed. The shape of the barrier ribs 29 is not limited to this, and may be a mesh shape that divides the discharge space into cells. This mesh-like partition is also called a grid-like rib, a box rib, a waffle rib or the like. The partition wall 29 can be formed by a sandblasting method, a printing method, a photoetching method, or the like. For example, in the sandblasting method, a glass paste having a low melting point glass frit, a binder resin, a solvent and the like is applied on the dielectric layer 24 and dried, and then a cutting having a partition pattern opening on the glass paste layer. It is formed by spraying cutting particles with the mask provided, cutting the glass paste layer exposed at the opening of the mask, and further firing. In the photo-etching method, instead of cutting with cutting particles, a photosensitive resin is used for the binder resin, and the mask is removed. It forms by baking after the used exposure and image development.

[0028] Red (R), green (G), and blue (B) phosphor layers 28R, 28G, and 28B are formed on the side and bottom surfaces of the groove-shaped discharge space between the barrier ribs 29! C Phosphor layer 28R, 28G, 28 Βί, phosphor powder containing phosphor powder, binder resin and solvent, screen printing in the grooved discharge space between the barrier ribs 29, or a method using a dispenser This is applied by repeating the process for each color and then firing. The force that the red phosphor layer 31R is formed in the lower layer of the blue phosphor layer 28Β according to the characteristics of the present invention will be described later.

[0029] In the PDP, the substrate 11 on the front side and the substrate 21 on the back side are arranged so that the display electrode X, Υ and the address electrode Α cross each other, the periphery is sealed, and the partition wall 29 The discharge space 30 surrounded by is filled with a discharge gas mixed with Xe and Ne. In this PDP, the discharge space 30 at the intersection of the display electrodes X and Y and the address electrode A is one cell (unit light emitting region) which is the minimum unit of display. One pixel consists of three cells, R, G, and B.

FIG. 2 is an explanatory view showing a phosphor layer of the PDP of the present invention. This figure shows a state in which the PDP is cut in a direction perpendicular to the partition wall.

As described above, the red phosphor layer 28R, the green phosphor layer 28G, and the blue phosphor layer 28B are formed in the elongated concave groove-shaped discharge space between the partition walls 29. In addition, a phosphor layer 31R of another color is formed as a reflective layer below the blue phosphor layer 28B. In the present embodiment, the other color phosphor layer 31R is the red phosphor layer 31R. These phosphor layers 28R, 28G, 28B, and 31R are formed by applying a phosphor paste by a method known in the art, that is, a screen printing method or a dispenser method, and drying and baking the phosphor paste. ing.

[0031] The red phosphor layer 31R formed below the blue phosphor layer 28B has a thickness of 10 to 30 / ζ πι at the thickest portion. The blue phosphor layer 28Β thereon is formed with a thickness of 10 to 30 μm at the thickest portion.

The total layer thickness of the blue phosphor layer 28B and the red phosphor layer 31R below the blue phosphor layer 28B is substantially the same as that of the red phosphor layer 28R or the green phosphor layer 28G. FIG. 3 is an explanatory view showing a phosphor layer of a comparative example.

In this comparative example, the red phosphor layer 28R, the green phosphor layer 28G, and the blue phosphor layer 28B are merely formed in the elongated concave groove-like discharge space between the partition walls 29 and 29. . There is only one blue phosphor layer 28B, and no other color phosphor layer is formed under the blue phosphor layer 28B. These phosphor layers 28R, 28G, and 28B are also formed by applying a phosphor paste by a method known in the art, that is, a screen printing method or a dispenser method, and drying and baking the phosphor paste.

4 (a) to 4 (f) are explanatory views showing a manufacturing process of the rear panel assembly (panel assembly) of the present invention shown in FIG. 2 in the order of steps.

First, a substrate 21 on the back side that also has glass power is prepared. In the next step, a conductive film such as a three-layer structure of CrZCuZCr or A1 is formed on the inner side of the substrate 21 by sputtering or the like. The conductive film is patterned into a desired shape by photolithography or the like to form the address electrode A (see FIG. 4 (a)). Address electrode A is also called data electrode

Then, the dielectric layer 24 is formed so as to cover the address electrode A in the next step. The dielectric layer 24 is formed by applying a low-melting glass paste by a screen printing method and baking it (see FIG. 4B).

In the next step, a partition wall 29 is formed on the dielectric layer 24 by a sandblasting method, a screen printing method, or the like (see FIG. 4C).

[0035] The force that forms the phosphor layer in the next step In the case of the comparative example shown in FIG.

, Red, green, and blue phosphor pastes are applied to the respective discharge cells, dried, and baked to form respective film thicknesses.

On the other hand, in the present embodiment, when the red phosphor paste is applied to the R cell,

Apply red phosphor paste to the B cell as well (see Fig. 4 (d)). In other words, red phosphor paste is applied to R cell and B cell at a time, then green phosphor paste is applied to G cell and dried (see Fig. 4 (e)). There is no particular limitation on the order of application. After that, apply blue phosphor paste to the B cell with a smaller filling amount than usual and dry it (see Fig. 4 (f)). [0037] The red phosphor material used for the red phosphor paste includes (Y, Gd) BO: Eu, YO

3 2

: Eu is used. The green phosphor material used for the green phosphor paste is Zn SiO

3 2

: Mn, Zn GeO: Mn, etc. are used. Blue phosphor material used for blue phosphor paste

4 2 2

As the material, BaMgAl 2 O 3: Eu, BaSrMgAl 2 O 3: Eu, or the like is used. Binder

10 17 10 17

As the resin and the solvent, those known in the art are appropriately used.

[0038] After the phosphor paste is applied and dried in the above process, the substrate 21 on the back side is loaded into the firing furnace, and the phosphor paste is fired to form the phosphor layer of the present embodiment. (See Fig. 2).

[0039] In the above, the red phosphor layer is formed under the blue phosphor layer, but the green phosphor layer may be formed by forming a phosphor layer of a color other than blue under the blue phosphor layer. Form it.

[0040] In general, light emission of a phosphor material excited by ultraviolet light in a PDP is light emission by a phosphor material up to a depth of about 10 / zm, and the underlying phosphor material below that acts as a reflector. ing. Therefore, it is desirable that the other color phosphor layer formed below the blue phosphor layer is formed by forming a phosphor material denser than the blue phosphor material as the reflective layer. Specifically, it is desirable to form a reflective layer having the same film thickness and a higher reflectance than the blue phosphor material.

[0041] In this way, the absolute amount of moisture taken into the panel is reduced by reducing the amount of blue phosphor material used. Of course, the amount of light emitted from the blue phosphor layer is reduced as it is, so that a phosphor layer of another color is formed as a reflective layer on the base to supplement the amount of light emitted from the blue phosphor layer.

[0042] In order to supplement the amount of light emitted from the blue phosphor layer, for example, when a white reflective layer is provided on the base of the blue phosphor layer, a step of forming a white reflective layer is required. Will increase and cost will increase. For this reason, from the viewpoint of shortening the manufacturing process and reducing the cost, a reflecting phosphor layer is formed under the blue phosphor layer using the existing red phosphor paste or green phosphor paste.

[0043] As described above, according to the present embodiment, before applying the blue phosphor paste, the phosphor paste of another color is applied to the area where the blue phosphor paste is to be applied in the same process. A phosphor layer formed of another color phosphor paste is used as a reflective layer. As a result, it is possible to reduce impurity gas such as moisture in the panel without increasing the number of steps without reducing the amount of light emitted from the blue phosphor layer, that is, at low cost.

Claims

The scope of the claims

[1] A set of a cell in which a red phosphor layer is formed, a cell in which a green phosphor layer is formed, and a cell in which a blue phosphor layer is formed in a discharge space formed between a pair of substrates Is a plasma display panel in which a large number of cells are arranged in a matrix,

A plasma display panel characterized in that a phosphor layer of another color is formed as a reflective layer under the blue phosphor layer.

2. The plasma display panel according to claim 1, wherein the phosphor layer of another color formed as the reflective layer is a red phosphor layer or a green phosphor layer.

3. The plasma display panel according to claim 1, wherein the total thickness of the blue phosphor layer and the phosphor layer below it is substantially the same as that of the red phosphor layer or the green phosphor layer.

[4] The blue phosphor material contained in the blue phosphor layer is BaMgAl 2 O 3: Eu or BaSrMgAl

10 17 1

The plasma display panel according to claim 1, which is O: Eu.

0 17

[5] A set of a cell in which a red phosphor layer is formed, a cell in which a green phosphor layer is formed, and a cell in which a blue phosphor layer is formed in a discharge space formed between a pair of substrates A method for forming a phosphor layer of a plasma display panel in which a large number of cells are arranged in a matrix,

The phosphor layer of each color is applied to the region where the phosphor layer is to be formed, dried, and baked to form a phosphor layer.

When applying the phosphor paste, apply it either when applying the red phosphor paste to the area where the red phosphor layer is to be formed, or when applying the green phosphor paste to the area where the green phosphor layer is to be formed. Apply the same phosphor paste to the blue phosphor layer formation planned area and dry it.

Thereafter, a phosphor layer forming method for a plasma display panel, comprising a step of applying a blue phosphor paste to a region where the blue phosphor layer is to be formed.