JPH11162347A - Method of forming phosphor layer for plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the flow-out of the phosphor paste at the time of coating by providing a flow-out preventing wall in each end of grooves between ribs, and to burn this flow-out preventing wall for elimination at the time of burning the phosphor in a method of forming phosphor layer for plasma display panel. SOLUTION: A method of forming phosphor layer for plasma display panel is formed of a coating process for coating grooves formed between plural band- like ribs provided in a board surface in parallel with each other by using a nozzle, and a burning process for burning the coated phosphor paste. Before the phosphor coating process, a flow-out preventing wall 3 is formed in an end of each groove, and the flow-out preventing wall 3 is burned for elimination in the phosphor burning process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a plasma display panel (PDP), and more particularly to a method of forming a phosphor layer between ribs on a substrate having a plurality of strip-shaped ribs (partitions) on the surface.

[0002]

2. Description of the Related Art A PDP is a self-luminous display panel in which a pair of glass substrates are arranged at very small intervals and a discharge space (discharge cell) is formed therein by sealing the periphery. In this PDP, by providing a phosphor layer of an ultraviolet excitation type in a discharge cell, the phosphor layer is excited by discharge, and a color can be displayed. PDP for color display is
It has phosphor layers of three colors of R (red), G (green), and B (blue).

Conventionally, the phosphor layers of R, G, and B are formed by applying a phosphor paste mainly containing powdered phosphor particles on a substrate by a screen printing method for each color in order, and after drying. It was formed using a firing method (see, for example, Japanese Patent Application Laid-Open No. H5-299019).

That is, in a PDP for color display, generally, a phosphor paste is applied in a groove (discharge cell) between stripe-shaped ribs formed on a substrate. In the screen printing, three screen masks for each color are used, the printing is performed three times by properly aligning the screen masks with the ribs, and the phosphor paste for each color is applied to the discharge cells for each color. I have to.

[0005]

However, in recent years,
As the display of the PDP becomes higher definition, higher accuracy of the alignment of the screen mask with the ribs is required. However, in the printing technique using the screen mask as described above, the resolution and the alignment accuracy are limited. . For this reason,
In recent years, attention has been paid to a so-called dispensing-type phosphor application technique in which a relatively soft phosphor paste is used, and the phosphor paste is directly applied to a groove between the ribs using a nozzle.

However, when the phosphor paste is applied by this dispensing method, since the viscosity of the phosphor paste is reduced, the phosphor paste flows out from the end of the rib after the phosphor paste is applied, and the adjacent groove is formed. There was a problem that flows into the.

The present invention has been made in view of such circumstances, and has an outflow preventing wall provided at an end of a groove between ribs to prevent the phosphor paste from flowing out during coating. The outflow prevention wall is burned off when the phosphor is fired.

[0008]

According to the present invention, there is provided an application step of applying a phosphor paste using a nozzle to a groove formed between a plurality of strip-shaped ribs provided in parallel on a substrate surface, Before the phosphor coating step, forming an outflow prevention wall for preventing the outflow of the phosphor paste at the end of each groove, and applying the outflow prevention wall in the phosphor baking step. A method for forming a phosphor layer of a plasma display panel, characterized by burning out.

According to the present invention, since the phosphor outflow preventing wall is formed before the phosphor applying step, it is possible to prevent the phosphor paste from flowing out from each groove end at the time of application. In addition, since the phosphor outflow prevention wall is burned off in the phosphor baking process, the phosphor outflow prevention wall may cause airflow obstruction in a later-described process of exhausting the panel and enclosing the discharge gas after sealing the panel. Can be prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a substrate having a plurality of strip-shaped ribs provided in parallel on its surface is used in advance. Each rib is preferably straight, but may be curved. As the substrate, a glass substrate used for a conventionally known PDP can be used.

The rib can be formed by a conventionally known material and method. For example, as a method for forming the rib, a screen printing method, a method in which an etching mask is provided on a sheet-like low-melting glass layer by photolithography, and patterning is performed by sandblasting (sandblasting method) can be used.

As a method of applying a phosphor paste using a nozzle to a groove formed between a plurality of ribs used in the application step, a dispenser (nozzle) for discharging the phosphor paste is relatively positioned with respect to the groove. And a so-called dispensing method of applying a phosphor paste in the groove.

As the phosphor paste, a conventionally known phosphor paste can be used. That is, a mixture of a resin and a solvent for each of the red, green, and blue phosphor materials can be used.

As a method for firing the phosphor paste used in the firing step, a conventionally known method can be applied. For example, the phosphor paste after drying is carried into a firing furnace by a belt conveyor together with the substrate, and is at a temperature not higher than the temperature at which the phosphor substance is degraded and at a temperature higher than a temperature at which the resin component can be burned off, about 440 to 460 ° C. The phosphor is baked by heating at the temperature described above to burn off the resin component mixed with the phosphor, whereby a phosphor layer can be formed.

The phosphor outflow preventing wall is formed at the end of each groove before the coating step in order to prevent the phosphor paste from flowing out. The material of the phosphor outflow prevention wall may be any material as long as it does not burn off and remain when the phosphor is fired, but is usually the same as the resin and solvent used in the phosphor paste. A mixture of a resin and a solvent is used.

Accordingly, the resin used for the phosphor outflow preventing wall includes polybutyl acrylate and polyacrylic acid which are used in a conventionally known phosphor paste.
Acrylic resins such as 2-ethylhexyl and polyacrylic acid, methacrylic resins such as polymethyl methacrylate (PMMA), 2-ethylhexyl polyacrylate and polymethacrylic acid, and cellulose resins such as methyl cellulose and ethyl cellulose are used. Similarly, as a solvent,
Alcohols, terpineol, cellosolve acetate, butyl carbitol acetate (BCA), butyl carbitol, toluene, butyl acetate, and the like, which are used in conventionally known phosphor pastes, are used.

Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. Note that the present invention is not limited to this. FIG. 1 is an explanatory diagram showing a configuration of an embodiment in which the present invention is applied to an AC-driven PDP for color display.

As shown in FIG. 1, in an AC-driven PDP 10 for color display according to the present invention, an inner surface of a front glass substrate (hereinafter referred to as a front substrate) 11 is provided for each line L of matrix display. A pair of sustain electrodes X,
Y is arranged. Each of the sustain electrodes X and Y includes a transparent electrode 12 and a metal electrode 13 and is covered with a dielectric layer 17. The dielectric layer 17 is made of magnesium oxide (M
gO).

On the inner surface of a rear glass substrate (hereinafter referred to as a rear substrate) 21, an address electrode A is formed on a base layer 22 so as to intersect with the sustain electrodes X and Y.
After the insulating layer 24 is formed thereon, a strip-shaped rib 29 is formed so as to sandwich the address electrode A. Phosphor layers 28R, 28G, 28B of three colors (R, G, B) are formed on the inner surface (bottom surface and side surface) of the elongated inter-rib groove (discharge space) defined by the strip-shaped rib 29.

Hereinafter, the steps of forming the phosphor layers 28R, 28G, 28B in the process of manufacturing the PDP 10 will be described. FIG. 2 is a perspective view showing a phosphor layer forming apparatus for a 42-inch color PDP. The above-mentioned phosphor layers 28R, 28
G and 28B denote a coating step of applying a phosphor paste by a dispense type phosphor layer forming apparatus 1 using a nozzle as shown in this figure, a drying step of drying the applied phosphor paste, and a drying step. The phosphor paste is formed through a firing step of firing the phosphor paste.

The phosphor layer forming apparatus 1 includes a mounting table 51,
An X-axis direction conveying device 54 for moving the nozzle 2 for applying the phosphor paste in the X-axis direction in the figure, and a pair of Y-axis direction conveying devices for moving the X-axis direction conveying device 54 in the Y-axis direction in the diagram. 52 and 53 are provided. Nozzle 2
It can be moved in the Z-axis direction in the figure, and is moved at the start and end of the application of the phosphor paste and when changing the color of the phosphor paste.

A substrate 50 is mounted on the mounting table 51. The substrate 50 is obtained by forming the ribs 29 on the above-described rear substrate 21 using a conventionally known material and method.
The rib 29 is formed so as to be parallel to the X axis.

The phosphor paste discharged from the nozzle 2 includes a conventionally known phosphor material for red, a phosphor material for green,
Resins and solvents are appropriately added to the blue phosphor material.

In the step of applying the phosphor paste by the phosphor layer forming apparatus 1, first, the nozzle 2 is moved to the application start point by the X-axis direction conveying device 54 and the Y-axis direction conveying devices 52 and 53, and the nozzle 2 is moved. Hold at a predetermined height. Usually, this position is the end of the rib 29.

Then, while discharging the red phosphor paste from the nozzle 2, the nozzle 2 is moved in the direction of the arrow X by the X-axis direction conveying device 54 and moved by the length of one rib 29. Is stopped, and the nozzle 2 is moved in the arrow Y direction by the Y-axis direction transfer devices 52 and 53. The movement amount at this time is 3 pitches (movement amount that skips the groove between the ribs 29 for green and blue).

Then, the nozzle 2 is moved in the opposite direction by the X-axis direction conveying device 54 while again discharging the red phosphor paste from the nozzle 2.

When these operations are sequentially performed and the application of the red phosphor paste is completed, the nozzle 2 is replaced.
Next, a phosphor paste for green and then a phosphor paste for blue are sequentially applied.

The order of the colors may be set arbitrarily. Alternatively, a plurality of nozzles 2 may be provided, and the phosphor paste may be applied to a plurality of grooves at once.

In the coating step, the phosphor paste is applied by the phosphor layer forming apparatus 1 as described above. As a pretreatment step of this coating step, an outflow preventing wall for preventing the outflow of the phosphor paste is provided. Provide.

FIG. 3 is an explanatory view showing the structure of the phosphor outflow prevention wall. The phosphor outflow prevention walls 3 are for preventing the phosphor paste from flowing out, and are formed at both ends of the rib 29.

The material of the phosphor outflow preventing wall is a mixture of the same resin and solvent as the resin and solvent used for the phosphor paste. In this example, ethyl cellulose was used as the resin, and cellosolve acetate was used as the solvent.

The phosphor outflow preventing wall 3 is formed by providing the phosphor layer forming apparatus 1 with an outflow preventing wall forming nozzle for discharging the paste for the phosphor outflow preventing wall, and applying the phosphor paste. First, the resin paste for the phosphor outflow prevention wall is formed by moving the outflow prevention wall forming nozzle in the direction of arrow Y by the Y-axis direction conveying devices 52 and 53 while discharging the resin paste for the outflow prevention wall forming nozzle. can do.

Next, the phosphor outflow prevention wall 3 is dried,
Eliminates the solvent component contained in the phosphor outflow prevention wall.
For drying after forming the phosphor outflow prevention wall 3, a heater may be provided on the back side of the mounting table 51 of the phosphor layer forming apparatus 1.

Alternatively, the formation of the phosphor outflow prevention wall 3 is as follows.
Prior to the application step by the phosphor layer forming apparatus 1, it may be formed in advance and dried.

FIG. 4 is an explanatory view showing a state in which the phosphor paste is applied after the phosphor outflow prevention wall 3 is formed. As shown in this figure, when the phosphor outflow prevention wall 3 is formed, the phosphor paste 4 is formed by the rib 29 and the phosphor outflow prevention wall 3 when the phosphor paste 4 is applied. Since it flows in the box to the position of the phosphor outflow prevention wall 3 by its own leveling property, uniform (uniform) phosphor paste 4 can be filled.

Therefore, when applying the phosphor paste 4 by the phosphor layer forming apparatus 1, it is not necessary to set the start position and the end position of the application so strictly. Also, the delay of the actual discharge start operation at the start of coating,
Such as the delay of the actual discharge stop operation at the end of coating,
Even if a timing deviation occurs, the level of the phosphor paste 4 becomes constant due to its own leveling property, so that a margin is provided for the control operation at the start and end of the application of the phosphor layer forming apparatus 1. it can.

In the coating step, as described above, as a pretreatment step of the coating step, an outflow preventing wall for preventing the outflow of the phosphor paste is provided, and then the phosphor paste is applied by the phosphor layer forming apparatus 1.

Next, in the drying step, the phosphor paste is dried by a conventionally known method. That is, the substrate is carried into a drying furnace by a belt conveyor, and heated at 100 to 150 ° C. for 1 to 2 hours to dry the phosphor paste and to remove the solvent component contained in the phosphor paste. The heating conditions are appropriately set according to the substrate size and the material of the phosphor paste.

Next, in the firing step, the dried phosphor paste is fired by a conventionally known method. That is,
The substrate after drying is carried into a firing furnace by a belt conveyor, heated at a temperature of about 440 to 460 ° C., and the phosphor paste is fired, and the resin component mixed with the phosphor paste is lost by burning, Thereby, a phosphor layer is formed.

In this firing step, the phosphor outflow prevention wall 3 is burned and burned at the same time as the phosphor to burn out. The same material as the resin used for the phosphor paste is used as the material for the phosphor outflow prevention wall 3, and these resins are usually decomposed and / or burned at a temperature of 230 to 300 ° C. The phosphor can be sufficiently burned off at the firing temperature of the phosphor.

FIG. 5 is an explanatory view showing a state in which a phosphor layer has been formed after firing. As shown in this figure, after the firing step, the phosphor outflow preventing wall disappears, and the phosphor layer 28
Since only R, 28G, and 28B remain, the phosphor outflow preventing wall does not hinder ventilation in the later-described step of exhausting the panel and enclosing the discharge gas after sealing the panel.

In this manner, the phosphor outflow preventing wall is formed before the coating step, and the phosphor outflow preventing wall is burned off in the phosphor baking step, so that the end of each groove of the phosphor paste at the time of coating is formed. Outflow from
Further, in the step of exhausting the inside of the panel and filling the discharge gas after the panel is sealed later, it is possible to prevent the phosphor outflow prevention wall from obstructing the ventilation.

In the embodiment described above, the outflow prevention wall is described as being formed at the time of applying the phosphor paste. However, the present invention is not limited to the application of the phosphor paste, and the groove between the ribs may be formed. The present invention can also be applied to a case in which an insulating paste is applied to form an insulating layer of an address electrode.

The PDP has been described by taking an AC driven PDP for color display as an example. However, the present invention is not limited to this, and a number of belt-like ribs are provided between a pair of substrates. What kind of PDP is a PDP having a configuration in which a pair of electrodes are arranged in a partitioned discharge space?
The present invention can be applied to DP.

[0045]

According to the present invention, even when a phosphor paste having a low viscosity is used, it is possible to prevent the phosphor paste from flowing out at the time of applying the phosphor paste, thereby enabling highly accurate filling. In addition, since the outflow prevention wall is burned off in the phosphor baking step, the outflow prevention wall which becomes an obstacle to ventilation in the step of exhausting and discharging the gas in the panel can be removed without providing a special removal step. This greatly contributes to the improvement of PDP performance.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment in which the present invention is applied to an AC-driven PDP for color display.

FIG. 2 is a perspective view showing an apparatus for forming a phosphor layer for a color PDP in an embodiment.

FIG. 3 is an explanatory diagram illustrating a configuration of a phosphor outflow prevention wall in an example.

FIG. 4 is an explanatory view showing a state in which a phosphor paste is applied after forming a phosphor outflow prevention wall in the example.

FIG. 5 is an explanatory view showing a state in which a phosphor layer is formed after firing in an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Phosphor layer forming apparatus 2 Nozzle 3 Outflow prevention wall 4 Phosphor paste 10 AC drive type PDP for color display 11 Front side substrate 12 Transparent electrode 13 Metal electrode 17 Dielectric layer 18 Protective film 21 Back side substrate 22 Base layer 24 Insulating layers 28R, 28G, 28B Phosphor layers 29 Ribs 50 Substrate 51 Mounting table 52 X-axis direction transfer device 52, 53 Y-axis direction transfer device A Address electrode L Display line X, Y Sustain electrode

Claims (2)

[Claims] 1. A coating step of applying a phosphor paste using a nozzle to a groove formed between a plurality of strip-shaped ribs provided in parallel on a substrate surface, and a firing step of firing the applied phosphor paste. Before the phosphor coating process,
A method for forming a phosphor layer for a plasma display panel, comprising: forming an outflow prevention wall at an end of each groove to prevent outflow of a phosphor paste; and burning out the outflow prevention wall in a phosphor baking step. 2. The outflow prevention wall is formed of a resin paste discharged from a nozzle.
The method for forming a phosphor layer of the plasma display panel according to the above.