JP4371501B2 - 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, in filling the phosphor paste into the space between the ribs , there is a step at the end of the rib near the outside of the formation pattern area, and the squeegee passes through this step, but the formation pattern once peeled off The plate emulsion surface at the end part flutters and re-contacts at the time of passing, and excess paste remaining on the emulsion surface adheres to the top of the rib, and depending on the situation, it flows out of the filling space and causes color mixing. Create a point.
[0006]
The present invention has been made in view of the above-described problems, and the object of the present invention is to form a phosphor paste at the end of the formation pattern when filling the space between the ribs with phosphor paste by screen printing. Another 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 color mixing.
[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 filling the phosphor paste in the space sandwiched between the ribs while moving the squeegee while holding the screen plate, the end of the rib on the terminal side where the squeegee moves 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 rib is affixed to the emulsion surface on the back side of the screen plate facing the rib so that the spacer moves while pressing the screen plate. It is characterized in that the squeegee comes down to the tip of the rib when it reaches the end of the rib .
[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, a spacer S having a thickness similar to the height of the rib 12 is attached to the emulsion surface on the back side of the screen plate 20, and this spacer S is the end of the squeegee when the screen plate 20 is pushed by the squeegee 22. It is located in the vicinity of the rib end on the side. Therefore, when the squeegee 22 moves while pressing the screen plate 20 and reaches the rib end portion, the spacer S 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. The squeegee 22 that holds the screen plate 20 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 spacer S and the rib 12 from overlapping, the spacer S is preferably installed so as to have an interval of about 1 to 2 mm from the rib end. In order to avoid the influence of the steps of the spacer S itself, it is preferable that the end of the spacer S is outside the area of the glass substrate 11 and the width of the spacer S is equal to or larger than the area width of the rib 12.
[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 having spacers attached to 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. . Thus, after filling and drying the three-color phosphor paste, visual inspection was performed, and no color mixing was observed at the pattern end.
[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. In this case as well, after three-color phosphor pastes were filled and dried, a visual inspection was performed, and color mixing was observed at the pattern end. In particular, there was much color mixing at the center in the width direction even at the end of the pattern.
[0018]
【The invention's effect】
As described above, according to the present invention, when the phosphor paste is filled in the space sandwiched between the ribs by screen printing, the vicinity of the end of the rib on the end side where the squeegee moves when the screen plate is pushed by the squeegee A spacer made of a resin film with a thickness corresponding to the height of the rib is affixed to the emulsion surface on the back side of the screen plate facing the rib so that the squeegee moves while pressing the screen plate. upon reaching the part, by the spacer it was so that going down the ribs above, since the stepped rib ends is eliminated, when the squeegee passes the rib ends, the screen plate may be such flutters Therefore, the excess paste remaining on the emulsion surface is prevented from adhering to the top of the rib, and color mixing is not caused.
[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 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. When filling the phosphor paste in the space sandwiched between the ribs by moving the squeegee, the ribs are positioned so that the screen plate is positioned near the end of the rib on the terminal side where the squeegee moves when pressed by the squeegee. A spacer made of a resin film with a thickness corresponding to the height of the rib is affixed to the emulsion surface on the back side of the opposite screen plate. When the squeegee moves while pressing the screen plate and reaches the end of the rib, the spacer A method for forming a phosphor screen of a plasma display panel, wherein the phosphor screen is lowered before the first step .

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