JP2001135228A - Method for forming fluorescent screen of plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent color mixture from causing at terminal parts of formed pattern, when filling fluorescent paste in rib spaces with screen-printing. SOLUTION: A spacer S equivalent to height of ribs 12 is installed near the rib end at the side of squeegee. Because a step at the rib end is eliminated, the screen print 20 will not flutter when a squeeze 22 passes the rib end, so that excess paste remaining on the face of emulsion is prevented from attaching to the rib top, not giving rise to such as color mixing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field 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 type flat panel display using gas discharge.
More specifically, the present invention relates to a method for forming a phosphor screen of a PDP.

[0002]

2. Description of the Related Art In general, a PDP has a structure in which a pair of electrodes arranged regularly on two opposing glass substrates are provided, and a gas mainly composed of Ne, Xe or the like is sealed between the electrodes. Then, a voltage is applied between these electrodes,
By generating a discharge in a minute cell around the electrode, each cell emits light to perform display. In order to display information, regularly arranged cells are selectively caused to emit light. There are two types of PDPs, a direct current type (DC type) in which the electrodes are exposed to the discharge space, and an alternating current type (AC type) in which the electrodes are covered with an insulating layer. And a refresh driving method and a memory driving method.

FIG. 1 shows a configuration example of an AC type PDP. This figure shows the front plate and the back plate separated from each other. As shown in the figure, two glass substrates 1 and 2 are arranged in parallel and opposed to each other, and both become the back plate. The ribs 3 provided on the glass substrate 2 in parallel with each other are held at regular intervals. On the back side of the glass substrate 1 serving as a front plate, composite electrodes composed of a sustain electrode 4 which is a transparent electrode and a bus electrode 5 which is a metal electrode are formed in parallel with each other, and a dielectric layer 6 is covered thereover. The protective layer 7 (MgO layer) is further formed thereon. On the front side of the glass substrate 2 serving as the back plate, address electrodes 8 are formed between the ribs 3 so as to be orthogonal to the composite electrodes and are formed in parallel with each other. Are formed, and a phosphor 10 is provided so as to cover the wall surface of the rib 3 and the cell bottom surface. The AC type PDP is of a surface discharge type, and has a structure in which an AC voltage is applied between composite electrodes on a front panel to discharge by an electric field leaking into a space. In this case, since the alternating current is applied, the direction of the electric field changes according to the frequency. Then, the phosphor 10 emits light by the ultraviolet light generated by the discharge, so that an observer can visually recognize the light transmitted through the front plate.

[0004]

Various methods such as a printing method and a photolithography method have been tried in the past to form a phosphor screen in a PDP as described above. Among them, the method of filling the phosphor paste into the space of the rib by screen printing requires a small amount of expensive phosphor, and the process is simple because the coating process and the patterning process can be performed simultaneously. There are significant benefits in terms of productivity, cost and cost. However, the screen printing method has the following problems.

Usually, in screen printing, the squeegee stroke length is set to be equal to or longer than the length of the pattern to follow the separation of the plate. However, when filling the rib space with the phosphor paste, there is a step at the end of the rib near the outside of the area of the formation pattern, and the squeegee passes through this step. The emulsion surface flutters during this passage and re-contacts, and the excess paste remaining on the emulsion surface adheres to the top of the ribs, and in some cases, flows out of the filling space to cause color mixing.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to fill a phosphor paste by screen printing into a space of a rib, and to form a phosphor paste at the end of a formed pattern. It is an object of the present invention to provide a method for forming a phosphor screen of a PDP, which is devised so as not to cause color mixing.

[0007]

In order to achieve the above object, according to the present invention, after forming ribs for defining a discharge space on a substrate, a phosphor paste is filled in the space of the ribs by screen printing. In the method of forming a phosphor screen of a PDP including a step, when the squeegee is moved while pressing the screen plate to fill the space of the rib with the phosphor paste, the height of the rib corresponding to the height of the rib near the end of the squeegee end side is provided. It is characterized by installing a spacer.

Specifically, for example, a spacer is attached to the emulsion surface on the back side of the screen plate, or the spacer is attached to a backing plate of the same height surrounding a substrate placed on a work table.

[0009]

FIG. 2 is an explanatory view showing an example of a 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 are formed. I have. The glass substrate 11 is surrounded by a pad 14 having the same height. Screen version 20 is frame 21
A mesh is stretched over the mesh, and a pattern formed on the mesh is patterned with an emulsion.
By moving the phosphor paste in the direction, the phosphor paste on the screen plate 20 is passed through the formation pattern and is filled in the rib space.

In the example shown in FIG. 2, a spacer S having the same thickness as the height of the rib 12 is attached to the emulsion surface on the back side of the screen plate 20, and the spacer S is pressed by the screen plate 20 by the squeegee 22. Sometimes it is located near the rib end on the squeegee end side. Therefore, when the squeegee 22 reaches the rib end while moving while pressing the screen plate 20, the spacer S equivalent to the height of the rib 12 descends to the tip of the rib 12, so that the step at the rib end is eliminated. Thus, the squeegee 22 holding the screen plate 20 moves smoothly.

FIG. 3 is an explanatory view showing another example of the phosphor screen forming method according to the present invention. In this example, a spacer S having the same thickness as the height of the rib 12 is attached to the upper surface of the backing plate 14, and the spacer S is applied to the rear side of the glass substrate 11 placed on the work table 13. When the plate 14 is applied, the glass substrate 11 is covered up to the vicinity of the rib end on the squeegee end side. Therefore, squeegee 2
2 moves while pressing the screen plate 20 and reaches the end of the rib, since the step at the end of the rib is eliminated by the spacer S corresponding to the rib height, the squeegee 22 holding the screen plate 20 moves smoothly. Will be.

As the material of the spacer, it is desirable to use a resin film, and among them, a PET (polyethylene terephthalate) film is preferable. It is best for the thickness of the spacer to be the same as the height of the rib, but it may be in the range of −50 μm to +100 μm relative to the height of the rib.

FIG. 4 shows the positional relationship between the substrate and the spacer when FIGS. 2 and 3 are viewed in plan. Spacer S
From the viewpoint of preventing the ribs 12 from overlapping with each other, it is preferable that the spacers S are provided so as to be spaced apart from the ends of the ribs by about 1 to 2 mm. In addition, in order to avoid the influence of the step of the spacer S itself, it is preferable that the end of the spacer S be outside the area of the glass substrate 11 and the width of the spacer S be equal to or larger than the area width of the rib 12.

[0014]

(Example 1) After patterning address electrodes on a glass substrate, a dielectric layer was formed to cover the address electrodes, and linear ribs were formed on the dielectric layer by sandblasting. . The width of the formed rib is 60 μm, the pitch is 220 μm, and the height is 120 μm. And FIG.
The phosphor paste was filled using a screen plate having a spacer attached to the emulsion surface as shown in (1). A 180 μm thick PET film was used for the spacer.

A paste containing a phosphor of green emission color (phosphor: 35% by weight of “P1-G1S” manufactured by Kasei Optonics Co., Ltd., resin solid content: 6.8 wt.
%, Solvent 58.2 wt%) between the ribs.
Dry at 0 ° C. for 30 minutes. Similarly, a paste containing a phosphor of blue emission color (phosphor: “K” manufactured by Kasei Optonics, Inc.
X-501A "27wt%, resin solid content 7.8wt%,
Solvent (65.2 wt%), paste containing phosphor of red emission color (phosphor: “KX-504” manufactured by Kasei Optonics Co., Ltd.)
A "35 wt%, resin solid content 4.1 wt%, solvent 57.
(9 wt%) between the ribs and dried similarly. After filling and drying the phosphor pastes of three colors as described above, a visual inspection was carried out, and no color mixture was observed at the end of the pattern.

Example 2 A rib space was filled with a phosphor paste in the same manner as in Example 1 except that a spacer was not attached to the screen plate but a spacer was attached to the backing plate as shown in FIG. . Also in this case, after the phosphor pastes of three colors were filled and dried, visual inspection was performed, and no color mixing was observed at the end of the pattern.

Comparative Example A rib space was filled with a phosphor paste in the same manner as in Example 1 except that conventional screen printing was performed without providing a spacer. And
Also in this case, after filling and drying the phosphor pastes of three colors, visual inspection was performed, and color mixture was observed at the end of the pattern. In particular, color mixing was large at the center of the width direction even at the end of the pattern.

[0018]

As described above, according to the present invention,
When filling the rib space with phosphor paste by screen printing, by installing a spacer equivalent to the height of the rib near the rib end on the squeegee end side,
Since the step at the end of the rib is eliminated, the screen plate does not flutter when the squeegee passes through the end of the rib, thereby preventing excess paste remaining on the emulsion surface from adhering to the top of the rib. The color mixing does not occur.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a plasma display panel in which a front plate and a back plate are separated from each other.

FIG. 2 is an explanatory diagram showing an example of a phosphor screen forming method according to the present invention.

FIG. 3 is an explanatory view showing another example of the phosphor screen forming method according to the present invention.

FIG. 4 is an explanatory diagram showing a positional relationship between a substrate and a spacer when FIGS. 2 and 3 are viewed in plan.

[Explanation of symbols]

 1, 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 backing plate 20 screen plate 21 frame 22 squeegee S spacer

Continued on front page F-term (reference) 5C028 FF16 HH14 5C040 FA01 GA02 GB02 GG09 JA12 MA02 MA22 MA23 5C094 AA08 AA42 BA31 BA32 CA19 DA13 EA04 EB02 EC03 FB12 FB16 FB20 GB10

Claims (3)

[Claims] 1. A method of forming a phosphor screen for a plasma display panel, comprising the steps of: forming a rib defining a discharge space on a substrate; and filling a phosphor paste in the space of the rib by screen printing. When filling the phosphor paste into the space of the rib by moving the squeegee while holding down, a spacer equivalent to the height of the rib is installed near the end of the rib at the end of the squeegee. Surface forming method. 2. The method for forming a phosphor screen of a plasma display panel according to claim 1, wherein a spacer is attached to the emulsion surface on the back side of the screen plate. 3. The method according to claim 1, wherein a spacer is attached to a backing plate of the same height that surrounds the substrate placed on the worktable.