JP4371502B2 - Method for forming phosphor screen of plasma display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a plasma display panel (hereinafter referred to as PDP), which is a self-luminous flat panel display using gas discharge, and particularly relates to a method for forming a phosphor screen of a PDP.
[0002]
[Prior art]
In general, a PDP has a structure in which a pair of electrodes regularly arranged on two opposing glass substrates are provided, and a gas mainly composed of Ne, Xe, or the like is enclosed therebetween. Then, a voltage is applied between these electrodes, and discharge is generated in minute cells around the electrodes, thereby causing each cell to emit light for display. In order to display information, cells arranged regularly are selectively discharged. There are two types of PDPs: a DC type (DC type) with electrodes exposed in the discharge space and an AC type (AC type) covered with an insulating layer, both of which vary depending on the display function and driving method. Further, it is classified into a refresh driving method and a memory driving method.
[0003]
FIG. 1 shows an example of the configuration of an AC type PDP. This figure shows a state in which the front plate and the back plate are separated from each other. As shown in the figure, two glass substrates 1 and 2 are arranged in parallel and facing each other, and both serve as a back plate. The glass substrate 2 is held at regular intervals by ribs 3 provided in parallel to each other. On the back side of the glass substrate 1 serving as the front plate, a composite electrode composed of the sustain electrode 4 that is a transparent electrode and the bus electrode 5 that is a metal electrode is formed in parallel with each other, and a dielectric layer 6 is formed covering the composite electrode. The protective layer 7 (MgO layer) is further formed thereon. In addition, address electrodes 8 are formed between the ribs 3 so as to be orthogonal to the composite electrode on the front side of the glass substrate 2 serving as a back plate, and are parallel to each other. The phosphor 10 is provided so as to cover the wall surface of the rib 3 and the cell bottom surface. This AC type PDP is a surface discharge type, and has a structure in which an AC voltage is applied between the composite electrodes on the front plate and an electric field leaks into the space. In this case, since alternating current is applied, the direction of the electric field changes corresponding to the frequency. And the fluorescent substance 10 is light-emitted by the ultraviolet-ray which arises by this discharge, and an observer visually recognizes the light which permeate | transmits a front plate.
[0004]
[Problems to be solved by the invention]
Various methods such as a printing method and a photolithographic method have been tried to form a phosphor screen in the PDP as described above. Among these methods, the method of filling the phosphor paste in the space sandwiched by ribs by screen printing requires a small amount of expensive phosphor, and also allows a coating process and a patterning process to be performed simultaneously. It is simple and has great advantages in both productivity and cost. However, the screen printing method has the following problems.
[0005]
Usually, in the case of screen printing, the squeegee stroke length is set to be equal to or longer than the formation pattern length in order to follow the plate separation. However, when filling the space between the ribs with the phosphor paste, there is a step at the end of the rib near the outside of the formation pattern area, so the plate emulsion surface is damaged when the squeegee passes through this step. A pin pole defect occurs. If such a pinhole is present, the paste adheres to the start and end portions of the formation pattern on the subsequent substrate, and spot-like color mixing defects occur mainly at the corners of the rib formation area.
[0006]
The present invention has been made in view of the above-described problems, and the object of the present invention is to provide a corner of a rib forming area when a phosphor paste is filled in a space between ribs by screen printing. An object of the present invention is to provide a method for forming a phosphor screen of a PDP that is devised so as not to cause spot color mixing in a portion.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a phosphor of a PDP including a step of forming a rib for partitioning a discharge space on a substrate and then filling the space sandwiched between the ribs with a phosphor paste by screen printing. in the surface forming method, when moving the squeegee while holding the screen plate filling the phosphor paste into the space sandwiched between the ribs, the starting end及beauty end the squeegee is moved when the screen plate is pressed by the squeegee A spacer made of a resin film having a thickness corresponding to the height of the ribs is attached to the emulsion surface on the back side of the screen plate opposite to the ribs so that the squeegee is positioned in the vicinity of the rib ends on the end side. When the rib reaches the rib start end while moving while pressing the screen plate, the spacer comes down before the rib, and when it reaches the rib end, It is characterized in that it has to come down to the ribs of the first.
[0008]
Delete [0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 is an explanatory view showing an example of the phosphor screen forming method according to the present invention. In the figure, reference numeral 11 denotes a glass substrate on which a plurality of ribs 12 parallel to each other is formed, and a step of filling the phosphor paste into a space sandwiched between the ribs by screen printing is performed on a predetermined work table 13. It is placed. Further, the glass substrate 11 is surrounded by a backing plate 14 having the same height. The screen plate 20 is a known one in which a mesh is stretched on a frame 21 and the formation pattern is patterned on the mesh with an emulsion. The squeegee 22 is moved in the X direction in the figure while holding the screen plate 20 as shown in the figure. Thus, the phosphor paste on the screen plate 20 passes through the formation pattern and fills the space between the ribs.
[0010]
In the example shown in FIG. 2, spacers S ₁ and S ₂ having a thickness similar to the height of the ribs 12 are respectively attached to the emulsion surface on the back side of the screen plate 20, and these spacers S ₁ and S ₂ are the screen plate 20. Are pushed by the squeegee 22 so that they are positioned in the vicinity of the rib ends on the squeegee start end side and squeegee end side, respectively. Therefore, when the squeegee 22 moves while pressing the screen plate 20 and reaches the rib start end, the spacer S ₁ corresponding to the height of the rib 12 descends before the rib 12, so that there is a step at the rib start end. The squeegee 22 that presses the screen plate 20 moves smoothly. Further, when the squeegee 22 further advances and reaches the rib end portion, the spacer S ₂ corresponding to the height of the rib 12 comes down to the tip of the rib 12, so that there is no step at the rib end portion and the squeegee that presses the screen plate 20. 22 moves smoothly.
[0011]
Delete [0012]
As a material for the spacer, it is desirable to use a resin film, and among these, a PET (polyethylene terephthalate) film is preferable. The thickness of the spacer is best to be the same as the height of the rib, but may be in the range of −50 μm to +100 μm with respect to the height of the rib.
[0013]
Positional relation between the substrate and the spacer when the Figure 2 in plan view is as shown in FIG. From the viewpoint of preventing the spacers S ₁ and S ₂ and the ribs 12 from overlapping, the spacers S ₁ and S ₂ are preferably installed so as to be spaced from the rib ends by about 1 to 2 mm. Further, in order to avoid the influence of the steps of the spacers S ₁ and S ₂ themselves, the end portions of the spacers S ₁ and S ₂ are outside the area of the glass substrate 11, and the widths of the spacers S ₁ and S ₂ are also the ribs 12. It is preferable that the width be equal to or greater than the area width.
[0014]
【Example】
( Example)
After patterning the address electrodes on the glass substrate, a dielectric layer was formed covering the address electrodes, and line-shaped ribs were formed on the dielectric layer by sandblasting. The formed rib has a width of 60 μm, a pitch of 220 μm, and a height of 120 μm. Then, as shown in FIG. 2, the phosphor paste was filled using a screen plate in which two spacers were pasted on the emulsion surface. As the spacer, a PET film having a thickness of 180 μm was used.
[0015]
Paste containing phosphor of green emission color (phosphor: “P1-G1S” 35 wt%, resin solid content 6.8 wt%, solvent 58.2 wt%, manufactured by Kasei Optonix) between screen ribs with a screen printer Filled and dried at 120 ° C. for 30 minutes. Similarly, a paste containing a phosphor having a blue emission color (phosphor: “KX-501A” manufactured by Kasei Optonics Co., Ltd., 27 wt%, resin solid content: 7.8 wt%, solvent: 65.2 wt%), fluorescence of red emission color A paste containing phosphor (phosphor: “KX-504A” manufactured by Kasei Optonics Co., Ltd., 35 wt%, resin solid content: 4.1 wt%, solvent: 57.9 wt%) was filled between the ribs and dried in the same manner. . This phosphor screen forming step was performed on 1000 glass substrates using the same screen plate, but no spot color mixture was observed at the pattern start and end portions.
[0016]
Delete [0017]
(Comparative example)
The phosphor space was filled with the phosphor paste in the same manner as in the example except that conventional screen printing was performed without providing a spacer. And when this fluorescent screen formation process was performed about 1000 glass substrates using the same screen plate, spot color mixture was seen in the pattern start end part and termination | terminus part.
[0018]
【The invention's effect】
As described above, according to the present invention, when filling the phosphor paste into the rib space by screen printing, the starting end及beauty rib end of termination side squeegee moves when the screen plate is pressed by the squeegee Two spacers made of a resin film having a thickness corresponding to the height of the ribs are pasted on the emulsion surface on the back side of the screen plate facing the ribs so that the squeegee presses the screen plate. Upon reaching the ribs beginning while moving together with the spacer come down in front of the ribs reaches the rib end portion, by the spacer was so that going down the ribs earlier, eliminating a step of rib end Therefore, when the squeegee passes the end of the rib, the emulsion surface of the screen plate is not damaged, and pinhole defects are therefore eliminated. Since nor to live, it is eliminated that cause defects in spot color mixture corner portion of the rib forming area.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a plasma display panel with a front plate and a back plate separated from each other.
FIG. 2 is an explanatory view showing an example of a phosphor screen forming method according to the present invention.
FIG. 3 is an explanatory diagram showing a positional relationship between a substrate and a spacer when FIG. 2 is viewed in plan.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Glass substrate 3 Rib 4 Sustain electrode 5 Bus electrode 6 Dielectric tank 7 Protection tank 8 Address electrode 9 Dielectric tank 10 Phosphor 11 Glass substrate 12 Rib 13 Work table 14 Base plate 20 Screen plate 21 Frame 22 Squeegee S ₁ , S ₂ spacer

Claims (1)

In a method for forming a phosphor screen for a plasma display panel, the method includes forming a rib for partitioning a discharge space on a substrate and then filling the space sandwiched between the ribs with a phosphor paste by screen printing, while holding a screen plate. moving the squeegee when filling the phosphor paste into the space sandwiched between the ribs, each positioned in the vicinity of the rib end portion of the starting side及beauty termination side squeegee moves when the screen plate is pressed by the squeegee As shown in the figure, spacers made of a resin film with a thickness corresponding to the height of the ribs are affixed to the emulsion surface on the back side of the screen plate facing the ribs, and the ribs are moved while the squeegee moves while pressing the screen plate. When it reaches the start end, the spacer descends before the rib, and when it reaches the end of the rib, the spacer descends at the end of the rib. A phosphor screen forming method of a plasma display panel, characterized in that it has come way.

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