JPH09161675A - Method for forming fluorescent surface of plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the exposure of a discharging electrode by forming an electrode so that the quantity of phosphor to be heaped on the electrode after forming a fluorescent layer is reduced, and to improve the brightness of PDP by forming a part except for the electrode into a fluorescent surface at the sufficient quantity of phosphor. SOLUTION: After filling a barrier space, which is surrounded by a cell barrier, with the phosphor paste, the paste is dried so as to vaporize the solvent of the paste, and a central part of a phosphor layer 7 is formed into the recessed-shape. At this stage, the barrier material, in which the solvent in the paste can be spread for intrusion, is used, and quantity of the paste to be heaped on an electrode pad 4 on a discharging electrode 2 is reduced. The sand blasting time for exposing the pad 4 is thereby shortened, and consequently, the residual quantity of the phosphor layer 7 is not reduced, and the luminance of a plasma display panel PDP can be improved. This process is repeated per each phosphor paste in red, green and blue so as to form each colored phosphor layer 7 in the predetermined barrier space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing process of a plasma display panel (hereinafter referred to as PDP), and more particularly to a method of forming a fluorescent screen on a cell barrier of a PDP.

[0002]

2. Description of the Related Art Conventionally, it has been proposed to provide a fluorescent screen on a wall surface of a cell barrier that defines a discharge space for the purpose of improving the brightness of a PDP. Then, as a method of forming a phosphor screen on the wall surface of the cell barrier, three types of phosphor pastes of red (R), green (G), and blue (B) are selectively filled into a predetermined cell barrier by screen printing. A method is known in which the phosphor layer deposited on the bottom surface is removed using a sandblast method, etc., and the electrodes required for discharge are exposed to form a predetermined phosphor screen after drying. See, for example, Japanese Patent Laid-Open No. 6-5205). In addition, the phosphor paste is completely filled into the cell barrier so that the top of the barrier is smooth, and then a sandblast-resistant mask is formed in a pattern such that the phosphor remains only on the wall surface, and then only the wall surface is sandblasted. A method of forming a fluorescent screen is also known.

[0003]

The method described in the prior art has the advantage that the production process is simple because it does not use a photosensitive paste, but until now it has been filled phosphor paste. The shape of the phosphor screen after drying could not be controlled. Therefore, the amount of the phosphor paste deposited on the bottom surface of the cell is large on the electrode and must be removed by sandblasting or the like, the processing time becomes long, and the brightness increases as the phosphor screen is formed in a larger area. Therefore, it is preferable to form it on the cell bottom surface excluding the discharge electrode, but there is a problem that it is difficult to form a fluorescent screen on the cell bottom surface other than the electrode portion necessary for discharge because the filling shape is not proper. .

The present invention has been made in view of the above problems. An object of the present invention is to improve the brightness of the PDP by reducing the amount of phosphor in the portion other than the discharge electrode portion on the inner surface of the cell. It is an object of the present invention to provide a phosphor screen forming method capable of easily forming a sufficient phosphor screen.

[0005]

In order to achieve the above object, a phosphor screen forming method according to the present invention fills a phosphor paste in a barrier space as a discharge space surrounded by a cell barrier and having an electrode on the bottom surface. And drying to evaporate the solvent contained in the phosphor paste to form a phosphor layer having a recessed shape in the central portion of the barrier space, and to expose the electrode portion necessary for discharge if necessary. In a method of forming a phosphor screen of a PDP, which includes a step of removing the phosphor layer deposited on the electrode by sandblasting, the phosphor layer is formed so that the amount of the phosphor deposited on the electrode after forming the phosphor layer is reduced. It is characterized in that the electrode portion necessary for discharge can be easily exposed by the subsequent sandblasting treatment by controlling the shape of the. And
There are the following three means for controlling the shape of the phosphor layer.

[0006] The first means is to use a barrier material having high wettability and / or permeability to the solvent in the phosphor paste. Specifically, 0.001 g of the solvent used for the phosphor paste was dropped on the surface of the sample formed by coating and baking on the substrate, and the spread portion on the sample surface when left for 5 minutes in a horizontal state A barrier material having a diameter of 10 mm or more is used.

The second means is that before filling the phosphor paste, the wettability to the solvent in the phosphor paste and / or
Alternatively, a highly permeable material is applied to the wall surface of the cell barrier. Specifically, a solvent used for the phosphor paste is applied to the surface of the sample formed by coating and baking it on the substrate with 0.0
01 g is dropped, and a material is applied so that the diameter of the spread portion on the surface of the sample becomes 10 mm or more when left for 5 minutes in a horizontal state. This material may be a phosphor paste.

The third means is to use an electrode material having low wettability and / or permeability to the solvent in the phosphor paste. Specifically, 0.001 g of the solvent used for the phosphor paste was dropped on the surface of the sample formed by coating and baking on the substrate, and the spread portion on the sample surface when left for 5 minutes in a horizontal state An electrode material having a diameter of 10 mm or less is used.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to examples.

(Embodiment 1) The evaluation method of the material performed in this embodiment is as shown in FIG. The solvent c (butyl carbitol acetate) used in the phosphor paste is applied to the surface of the sample b (film thickness after baking: 10 μm) formed by applying and baking on the substrate a, the micro syringe d (needle inner diameter). : 0.3 mm).
The dropping amount is 0.001 g. Leave it horizontal for 5 minutes at room temperature and atmospheric pressure. The diameter A of the spread portion of the solvent c on the sample surface is measured.
The measurement of the spread portion includes both the sample surface portion and the penetration portion.

Table 1 shows the materials used in this example and the measurement results by the above evaluation method.

[0012]

[Table 1]

FIG. 2 is a sectional view of the panel used in this embodiment.
Shown in In this panel, patterns of electrodes 2, overcoat 3, electrode pads 4 and cell barriers 5 are formed on a glass substrate 1 by a screen printing method, a filling method, a sand blast method or the like and baked. In this embodiment, the cell barriers 5 have a pitch of 500 μm and a line width of 100 μm.
A panel having a matrix pattern of m and a film thickness of 150 μm, in which a square electrode pad 4 having a side of 150 μm is exposed near the center of the bottom surface of the barrier space was used. Further, in this embodiment, a black material “NP7948” is provided on the top of the barrier 5.
(Manufactured by Noritake Company Limited) were laminated.

Next, a fluorescent screen is formed on the panel. First, as shown in FIG. 3, a phosphor paste 6 was filled in a barrier space as a discharge space surrounded by the cell barrier 5 by a screen printing method, and then dried at 150 ° C. for 20 minutes. By filling and drying the phosphor paste 6 in the barrier space in this way, the solvent contained in the paste is vaporized, and the phosphor layer composed of the phosphor and the paste has a concave shape at the center of the cell. . At this time, the barrier material is shown in Table 1.
When a material such as "NP7947" (manufactured by Noritake Co., Ltd.) in which the solvent in the phosphor paste spreads quickly and soaks in, the shape of the phosphor layer 7 becomes as shown in FIG. 4 (a). , Table 1 "NP781
If the solvent such as “0” (same as above) in which the solvent in the phosphor paste is repelled on the barrier and is difficult to spread is used, the impregnation of the solvent into the barrier-forming material is delayed, so that the entire surface is loose. The attached shape is as shown in FIG. And this process is red (R), green (G), blue (B)
This phosphor paste was performed three times in total, and the phosphor layers 7 of the respective colors were formed in the predetermined barrier spaces.

As the phosphor powder, red phosphor and Y ₂ O are used.
₃ : Eu, BaAl ₁₂ O ₁₉ : Mn was used for the green phosphor, and BaMgAl ₁₄ O ₂₃ : Eu ²⁺ was used for the blue phosphor. The phosphor paste used was a paste in the weight ratio of phosphor / binder resin (ethyl cellulose) / solvent (butyl carbitol acetate) = 50/5/45. Although the screen printing method is used as the filling means of the phosphor paste, the present invention is not limited to this and may be filled by other means such as a spray method. Further, the phosphor, the binder resin, and the solvent are not limited to these, and may be appropriately selected depending on the combination with the barrier material. What is important is how the phosphor paste spreads when it is applied to the barrier material or how easily it is impregnated.

Subsequently, the phosphor layer 7 deposited on the electrode pad 4 in order to expose the electrode portion required for discharge was removed by sandblasting. As a result, among the materials shown in Table 1 in which the material whose measured value is one digit is used (NP7810), the exposure of the discharge electrode after filling and drying is small and the load on the sandblasting process for the discharge electrode exposure becomes large, In addition, since the shape of the phosphor layer is not appropriate, the amount of phosphor remaining on the cell bottom surface on the phosphor surface after sandblasting is reduced. In contrast, materials with two or more digits (N
In the case of using P7947), since the shape is improved, it becomes possible to form an appropriate phosphor screen in a short sandblasting time. Note that one of the four cells
Since the blast rate is slower than other phosphor pastes, the cell was thinly applied, and it was confirmed that the electrodes were exposed enough to be used without sandblasting.

(Example 2) A panel similar to that used in Example 1 was filled with a sufficiently diluted phosphor paste and dried, and as a result, fluorescence having phosphors preferentially adhered to the wall surface of the cell barrier was obtained. The surface was formed. Next, in the same manner as in Example 1, the barrier space was filled with the phosphor paste by a screen printing method, and then dried at 150 ° C. for 20 minutes. After that, as a result of exposing the electrode by sandblasting,
A phosphor screen having the same shape as in Example 1 could be formed. In this embodiment, the phosphor paste diluted as the material that easily penetrates is used, but the material is not limited to this, and the barrier wall surface may be covered with a material having a measured value of 10 mm or more by the above measurement. It is a thing.

(Embodiment 3) The material evaluation method performed in this embodiment is the same as that described in Embodiment 1, and an electrode material is used as the sample b instead of the barrier material. Table 2 shows the materials used in this example and the measurement results.

[0019]

[Table 2]

The same phosphor paste was filled in the barrier space of the same panel as that used in Example 1 by the screen printing method, and then dried at 150 ° C. for 20 minutes to remove the solvent contained in the paste. And a phosphor layer having a concave shape at the center was obtained. At this time, as the electrode material, the ruthenium oxide paste “ESL3115” shown in Table 2 was used.
4A, the phosphor layer 7 has a shape as shown in FIG. 4A, and the nickel-based paste "ESL2" is used.
The one using "556" (manufactured by ESL) is as shown in FIG. 4 (b). Similar results were obtained when "ESL3114, 3116" was used as the ruthenium oxide paste and "ESL2554, 2555" was used as the nickel paste. Then, as a result of exposing the electrodes by sandblasting, the discharge electrodes were less exposed in the material (nickel-based paste) with a measured value of two digits, and compared with the material of less than one digit (ruthenium oxide-based paste). The load on the sandblast for forming the fluorescent screen was increased.

[0021]

As described above, the PD according to the present invention
In the method for forming the phosphor screen of P, a phosphor paste is filled in the barrier space of the cell barrier and dried to form a phosphor layer having a concave shape in the central portion of the barrier space, and if necessary, sandblasting is performed. In the method for forming the phosphor screen in which the electrode portion required for discharge is exposed by the method, the shape of the phosphor layer is controlled so that the amount of the phosphor deposited on the electrode after forming the phosphor layer is reduced. The discharge electrode can be easily exposed without treatment or even with sandblasting, and as a result, a phosphor screen having a sufficient film thickness can be formed on the wall surface and the bottom surface.
The brightness of P can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a material evaluation method.

FIG. 2 is a cross-sectional view of a panel used in an example.

FIG. 3 is a cross-sectional view showing a state immediately after filling the barrier space with a phosphor paste.

FIG. 4 is a cross-sectional view showing a state after the filled phosphor paste is dried.

[Explanation of symbols]

 1 Glass Substrate 2 Electrode 3 Overcoat 4 Electrode Pad 5 Cell Barrier 6 Phosphor Paste 7 Phosphor Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuto Shibuya 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd.

Claims (8)

[Claims] 1. A phosphor paste is filled in a barrier space as a discharge space which is surrounded by a cell barrier and has an electrode on the bottom surface, and is dried to vaporize a solvent contained in the phosphor paste to thereby vaporize the solvent in the barrier space. Plasma display panel including a step of forming a phosphor layer having a recessed shape in a central portion, and a step of removing a phosphor layer deposited on the electrode by sandblasting to expose an electrode portion required for discharge, if necessary The method for forming a phosphor screen of a plasma display panel, wherein the shape of the phosphor layer is controlled so that the amount of phosphor deposited on the electrode after the phosphor layer is formed is reduced. 2. The phosphor screen of claim 1, wherein a barrier material having high wettability and / or permeability to a solvent in the phosphor paste is used to control the shape of the phosphor layer. Method. 3. A sample in which 0.001 g of a solvent used for a phosphor paste is dropped on the surface of a sample formed by coating and baking the barrier material on a substrate, and left standing in a horizontal state for 5 minutes. The method for forming a phosphor screen of a plasma display panel according to claim 2, wherein the barrier material is such that the diameter of the widened portion on the surface is 10 mm or more. 4. In order to control the shape of the phosphor layer, a material having high wettability and / or permeability to the solvent in the phosphor paste is applied to the wall surface of the cell barrier before filling the phosphor paste. Item 2. A method for forming a phosphor screen of a plasma display panel according to item 1. 5. The sample surface when 0.001 g of the solvent used for the phosphor paste is dropped on the surface of the sample formed by coating and baking the material on the substrate, and the sample surface is left for 5 minutes in a horizontal state. The method for forming a fluorescent surface of a plasma display panel according to claim 4, wherein the material is such that the diameter of the widened portion at 10 mm is 10 mm or more. 6. The method for forming a phosphor screen of a plasma display panel according to claim 4, wherein the material is a phosphor paste. 7. The method for forming a phosphor screen of a plasma display panel according to claim 1, wherein an electrode material having low solvent wettability and / or penetrability of the phosphor paste is used to control the shape of the phosphor layer. . 8. A sample obtained by dropping 0.001 g of a solvent used for a phosphor paste on the surface of a sample formed by coating and baking the electrode material on a substrate, and leaving it in a horizontal state for 5 minutes. The method for forming a phosphor screen of a plasma display panel according to claim 7, wherein the electrode material is such that the diameter of the widened portion on the surface is 10 mm or less.