KR100744573B1 - plasma display panel - Google Patents

Abstract

The present invention relates to a method of forming a plasma display partition wall using a soft mold, and the present invention provides a method for preparing a soft mold, and filling the photosensitive partition wall paste into the soft mold and temporarily curing the filled photosensitive partition wall paste so as not to flow. Step and sealing the inlet of the photosensitive partition wall paste with a polymer resin or a hot melt resin, cutting the soft mold to fit the display size and the step of the temporary photosensitive partition wall paste on the back substrate formed by a separate process It is aimed at presenting a sixth step of press molding after alignment.

Plasma display; septum

Description

Plasma display panel

1 is a cutaway perspective view of a conventional surface discharge type AC PDP.

Figure 2 is a process diagram of a part of an embodiment according to the present invention, a stripe type soft mold and its cross-sectional view.

3 is a process diagram of one embodiment according to the present invention, (a) is a photosensitive partition paste, and (b) is a process diagram for uniformly removing the paste applied to the mold thick film portion using a roller.

Figure 4 is a process diagram of a part of an embodiment according to the present invention, a process chart for making a sheet for the partition wall by UV pre-curing.

5 is a process diagram of a part of an embodiment according to the present invention, which is a process chart for cutting a partition sheet to a display size.

FIG. 6 is a process diagram of a part of an embodiment according to the present invention, in which an adhesive is applied to impart adhesion to a back substrate.

7 is a process diagram of a part of an embodiment according to the present invention, in which pressure is applied to a partition sheet to attach to a rear substrate.

8 is a process diagram of one embodiment according to the present invention, (a) is a process chart for releasing a mold on a partition sheet on a rear substrate, and (b) is a process chart for forming a partition by firing.

***** Explanation of the main symbols in the drawings *****

10: soft mold 20: coating roll

30: photopolymerization type photosensitive partition wall paste 40: cutting roll

50: polymer resin or hot melt resin

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (PDP) manufacturing technology, and more particularly, to a paste composition for forming barrier ribs of PDP and a method of forming partition walls using the same.

The plasma display panel (PDP) is a display element for displaying an image by using a plasma generated at the time of gas discharge, and is also called a gas discharge display element. The PDP fills discharge gas such as Ne and Xe between the upper plate and the lower plate, and the vacuum ultraviolet rays generated through the gas discharge excite the red (R), green (G), and blue (B) phosphors to generate visible light.

1 is a cross-sectional view of a conventional surface discharge AC drive type PDP. Referring to FIG. 1, in the surface discharge type AC drive PDP (hereinafter referred to as "PDP"), a back substrate 1, an address electrode 2, a white dielectric 3, a partition wall 4, etc. form a back plate. The front substrate 5, the transparent electrode 6, the bus electrode 7, the transparent dielectric 8, the dielectric protective film (not shown), the black stripe (not shown), etc. To achieve. In addition, phosphors R, G, and B 9 for realizing color in the PDP are disposed between the partition walls 4.

Among these, the partition wall has a three-dimensional structure with a line width of about 50 to 80 µm, which makes the formation process difficult. PDP bulkhead formation processes include screen printing method, sand blast method, photolithography, press method, and LTCC-M (Low Temperature Co-fired). Ceramic on Metal) and the like are known.

Screen printing is a method of repeating a desired pattern printing and drying process several times using a screen mask. Since the screen printing method requires repeated printing several times until the desired barrier height is obtained, the barrier wall is inclined, the instability of the discharge characteristics due to the height variation of the barrier wall, the uniformity in the formation of phosphors, and the screen mask mesh ) Marks are pointed out as a problem, the yield is expected to decrease due to poor reproducibility, and due to the limitation of the screen mask, it is difficult to produce a high-definition pattern.

For reference, the height of the barrier rib formed in one printing is about 15 to 25 μm, and the height of the desired barrier rib is usually 100 to 200 μm. In addition, the flatness of the partition wall during printing may be deteriorated due to the pattern stain generated during the mask fabrication process, which not only affects the formation of the phosphor, but also causes an unstable discharge during image implementation. In addition, the width of the printable pattern is limited due to the width of the mask pattern and the screen mesh, and thus, it is pointed out as an obstacle to producing high-definition and high-quality panels.

In the sand blasting method, after the barrier paste is applied and dried to a thickness of 200 to 300 μm, the dry film resist (DFR) having a sanding resistance is laminated and patterned through an exposure and development process. Using this pattern as a mask, the partition paste is scraped off with fine abrasive grains. This sandblasting method has the advantage that it is possible to form a high-definition partition wall compared to the printing method, but the process is complicated and material loss, and the separation of the powder mixture produced during the sandblasting process is not easy and environmentally friendly because it is a pollution material There is a problem. Above all, it is pointed out that the cracks in the partition wall during the subsequent firing process are large because the physical impact caused on the glass substrate during the sandblasting process is large.

Photolithography is a process of applying and drying the photosensitive partition wall paste, exposing with a photomask, and then selectively dissolving and removing the non-exposed portion of the paste using a developer. While the photolithography method has an advantage in that precise dimension adjustment is possible, the loss of the paste is large, and it is difficult to form a partition wall having a height of 100 μm or more because it is difficult to photosensitive to the lower part of the photosensitive partition paste.

The mold method attaches a green tape on a substrate, aligns the plate-shaped metal mold with the partition pattern engraved on the green tape, performs pressure molding under high temperature conditions, and then moves the plate-shaped metal mold in the vertical direction. It is a process of separating and forming a partition. This mold method has the advantage that the process is very simple and the material utilization is high, while the height uniformity of the obtained partition wall is inferior, and the glass substrate is broken due to the pressure applied to the mold of a large area. Since the contact area between the metal mold and the green tape is large, separation (demolding) is difficult.

Low Temperature Co-fired Ceramic on Metal (LTCC-M) method attaches a green tape on a metal substrate (for example, Ti), forms an address electrode and a dielectric layer on the green tape, and then embosses a mold of a plate metal mold. It is a process of forming a partition by press molding with an embossing mold. This LTCC-M method can solve the alignment problem because the process is simple, the equipment and material cost is reduced, and there is little shrinkage of the bulkhead pattern during the simultaneous firing. In addition, since the heavy glass substrate is replaced with a thin metal plate, there is an advantage of reducing the weight of the rear substrate, and the heat dissipation characteristics of the rear substrate are excellent by using a metal substrate having high thermal conductivity. However, in order to be applied to mass production of PDP, technical matters such as securing ease of demolding after pressing molding, suppressing cambar generated during simultaneous firing, and preventing bending of back substrate during pressing molding should be solved.

On the other hand, a rolling mold method (rolling mold method) has been proposed in order to reduce the damage of the glass substrate due to the high pressure during the press molding, which is a disadvantage of the mold method. The rolling mold method is a process of pressing a barrier rib paste applied on a substrate by rolling a metal cylinder (rolling mold) in which a stripe-shaped barrier rib is engraved on an outer circumferential surface thereof, and rolling the mold into a horizontal direction with respect to the substrate. Therefore, the glass substrate has a small pressure compared to the conventional mold method to prevent damage to the glass substrate, there is an advantage that does not require a cumbersome demolding process. However, it is difficult to manufacture metal molds because it is not easy to process metals, and thus, there is a disadvantage in that mold manufacturing costs are high.As the rolling progresses during molding, the paste adheres to the mold, so that a uniform partition pattern of high-definition can be obtained in a continuous process. There was a hard problem to get.

The present invention has been proposed to solve the problems of the prior art as described above, and after filling the partition wall paste in PET and soft mold (pre-curing) and making a pre-curing partition wall sheet on the sheet It is an object of the present invention to provide a method for forming a partition wall of a plasma display panel which is sealed by using a polymer resin or hot melt and then cut to fit the size of the display panel and press-molded on a glass substrate.

In addition, an object of the present invention is to provide a paste composition for forming partition walls of a plasma display panel to facilitate demoulding of a mold after pressure molding.

The object of the present invention is the first step of preparing a soft mold, the second step of filling the photosensitive partition paste into the soft mold and the third step of preliminarily hardening the filled photosensitive partition paste does not flow, and the photosensitive partition wall paste Aligning the photosensitive barrier rib paste on the back substrate formed by a fourth step of sealing the inlet with a polymer resin or a hot melt resin, a fifth step of cutting the soft mold to fit the display size, and a separate process, and then press molding And a sixth step, wherein the fourth step and the fifth step can be achieved by a method of forming a partition wall of the plasma display panel, regardless of the order.

Hereinafter, with reference to the accompanying drawings will be described in detail the advantages, features and preferred embodiments of the present invention.

2 to 8 is a process chart of forming a partition sheet of the display panel size by filling the partition paste in the soft mold according to an embodiment of the present invention, it will be described with reference to this.

First, as shown in FIG. 2, a stripe type soft mold 10 made of PET (polyethylene terephthalate) material is prepared, and then a photopolymerization type is shown in FIG. 3 (a). The photosensitive partition wall paste 30 is filled by the depth of the soft mold 10 using the coating roll 20. The photosensitive partition face 30 was designed to have a viscosity of 1,000 to 4,000 cps. At this time, the depth of the soft mold 10 is formed according to the height of the PDP partition wall, and is formed to be approximately 100 to 200 μm. Instead of the coating roll 20, it is a matter of course that a variety of paste coating apparatus, such as knife (knife) or bar (bar) shape can be used. PET is made by polymerizing ethylene glycol with terephthalic acid or dimethyl terephthalate.

Next, as shown in FIG. 3 (b), the paste 30 applied to the portion of the thick film beyond the height of the partition cell is scraped off with a cutting roll 40 or a knife to paste the paste on the thick film of the glass substrate. Try not to exist if possible.

Conventionally, PDMS (PolydimethylSiloxane) material is mainly used to form PDP barrier ribs using a soft mold. In the case of the soft mold of PDMS material, the releasability after demolding the partition wall to the lower substrate is good, but there is a problem in that the dimension of the partition wall cannot be accurately represented due to a weak hardness and a problem in shrinkage force. In contrast, the present invention has an advantage of accurately expressing the dimensions of the partition wall by using a soft mold made of PET material having a higher hardness than PDMS.

As shown in FIG. 4, the photopolymerized photosensitive partition wall paste filled in the soft mold of PET material is pre-heated at 50 ° C. to 80 ° C. in order to prevent flowing or flowing down.

Next, as shown in FIG. 5, the sheet filled with the barrier paste cured in the soft mold is cut according to the size and process of the display panel. In Fig. 5 the cutting position is indicated by a simple arrow. When using PDMS as a soft mold forming material, there is a problem in that the shape of the partition wall is damaged during cutting. However, in the present invention, since the soft mold is made of a PET material having high hardness, cutting is easy and simple.

Hereinafter, a process of applying a soft mold of PET material having a hardened partition wall to the PDP lower substrate will be described.

As illustrated in FIG. 6, the hardened partition wall is sealed with a polymer resin or a hot melt resin 60 to several tens of micrometers. The type of polymer resin or hot melt resin 60 may be a PU (PolyUreathane) resin, an acrylic resin, an acrylic resin, a melamine resin, an epoxy resin, a polyester resin, or the like. Was used. As the polymer resin, D-ace 600 was used as the polyurethane adhesive of the manufacturer Dongsung Chemical, and EVA hot melt resin DJ 104 of the manufacturer Daejin Chemical was used as the hot melt resin. The step of suture shown in FIG. 6 may be carried out after curing as shown in FIG. 4 and before the cutting process of FIG. 5.

Next, as shown in FIG. 7, the partition sheet is aligned with the stacked rear substrate 100, and then press molding is performed. Herein, the stacked back substrate 100 refers to a substrate in which an address electrode and a white dielectric are stacked on the back substrate, and generally refers to a substrate in which components immediately before the partition walls are stacked. At this time, the back substrate temperature is maintained at a temperature of 30 ° C. to 80 ° C., and the ultraviolet ray (UV) exposure is performed on the photopolymerizable photosensitive partition wall paste 30 while maintaining the state before demolding the mold. In this case, UV exposure is preferably performed for 30 to 50 seconds using a 20W UV lamp, and if the total exposure energy is in the range of 230 to 250 mJ / cm 2, the photopolymerized photosensitive partition wall paste having a height of 100 to 250 μm with only one exposure ( 30) can be sufficiently exposed.

As shown in Fig. 8, demolding the soft mold 10 made of PET material and stopping for 30 minutes at 350 to 380 ° C at a temperature increase rate of 5 to 10 ° C / min, and then stopping for 30 minutes at 550 to 580 ° C and then cooling. The firing process was carried out to remove the organic component, leaving only the inorganic partition material, thereby obtaining a uniform partition having a height of 150 to 200 µm.

On the other hand, the present invention proposes a photopolymerizable photosensitive partition paste composition that facilitates demolding of the soft mold and the press-formed partition wall paste, and specifically, 50 to 70% by weight of the inorganic partition material powder, 10 to 30% by weight of the binder polymer, and a multi-pipe. A photopolymerizable photosensitive barrier paste composition comprising 10 to 30 wt% of a functional monomer or oligomer, 1 to 3 wt% of a photoinitiator, 0.5 to 2 wt% of a release agent, and a residual amount is proposed. In addition, 0.5 to 2% by weight of an additive such as a dispersant, an antifoaming agent, a smoothing agent, and a polymerization inhibitor may be further added to the photopolymerizable photosensitive partition paste.

Inorganic bulkhead material powder generally refers to a ceramic-reinforced composite material in which mainly red-borosilicate (PbO-SiO2-B2O ₃ ) powder and ceramic powders Al2O _3, TiO ₂ , ZnO, etc. are added. Methyl ethyl ketone (MEK), BTX (benzene, toluene, xylene), N, N-dimethylformamide diethyl acetal (N, N-DIMETHYLFORMAMIDE DIETHYL ACETAL) and the like were used.

Example

Table 1 sets forth the photopolymerizable photosensitive bulkhead paste composition used in the practice of the present invention.

Item ceramic A / A3598 A / A1924 TMPTA HEA Aerosil HSP188 TPO IC-184 Experiment 1 70 15 13 2 0.5 2 Experiment 2 75 13 10 2 0.5 2 Experiment 3 70 10 10 7 3 Experiment 4 50 20 20 8.5 1.5 Experiment 5 70 10 10 7 3 Experiment 6 70 10 5 12 3

The ceramic used was the average particle size of 1.9 ㎛ of NIHON YAMAMURA GLASS. A / A3598 and A / A1924 are polymer resins, which are solvent type and aqueous type, respectively.

Trimethylolpropane trimethacrylate (TMPTA) and 2-Hydroxyethyl acrylate (HEA) were tri- and mono-functional monomers, and Aerosil was added for viscosity and plasticity. HSP188, TPO, and IC-184 were used as photoinitiators.

Each experimental result is shown in Table 2.

Paste viscosity (cps) Filling UV curing Dysplasia Plastic properties Experiment 1 2,500 ○ ○ △ △ Experiment 2 3,500 ○ ○ △ △ Experiment 3 2,000 ◎ ○ ○ × Experiment 4 1,500 ◎ ○ ○ × Experiment 5 3,000 ◎ ◎ ◎ ◎ Experiment 6 3,000 ◎ ◎ ◎ ◎

◎: very good ○: good

△: normal ×: bad

The experimental results in Table 2 were measured using the Brookfield DV-11 Viscometer of the United States in the viscosity of the spindle s1 at 20 degrees Celsius, plastic profile analysis TGA analysis at elevated temperature 5 ~ 10 degrees / min The shape was taken by SEM photographs, and the light amount was measured by applying 100 ~ 200mJ / cm ² using a 20 watts UV lamp.

As an example, IC-184 in the short wavelength region at a composition ratio of 50 to 70% by weight of the inorganic barrier material powder, 10 to 30% by weight of the binder polymer, 10 to 30% by weight of the polyfunctional monomer or oligomer, and 1 to 3% by weight of the photoinitiator. Experimental results using the photoinitiator showed that the partition wall formation was easy and the plasticity characteristics were very good. The use of a release agent exhibiting release properties in this composition ratio can also be considered.

As described above, the present invention has the advantage that it can be used in any size PDP manufacturing process because the partition sheet formed by using a soft mold of PET material can be cut and used according to the size of the display. In addition, the present invention has the effect of minimizing the loss of the partition wall during the demolding process by curing the paste in a short time by using a soft mold of PET material with high UV transmittance.

While preferred embodiments of the present invention have been described using specific terms, such descriptions are for illustrative purposes only and it is understood that various changes and modifications may be made therein without departing from the spirit and scope of the following claims. You must lose.

Claims (12)

A first step of preparing a soft mold; A second step of filling the photosensitive partition wall paste into the soft mold; A third step of temporarily curing the filled photosensitive partition wall paste so as not to flow; A fourth step of sealing the inlet of the temporary photosensitive partition wall paste with a polymer resin or a hot melt resin; A fifth step of cutting the soft mold to fit a display size; And And arranging the temporary photosensitive barrier rib paste on a rear substrate formed by a separate process, and then pressing the molded article, wherein the fourth step and the fifth step are performed in any order. How to form partition walls of panels. The method of claim 1, The soft mold is formed of a polyethylene terephthalate (PET) material, characterized in that the partition wall forming method of the plasma display panel. The method of claim 1, The method of claim 4, wherein the sealing of the fourth step is made of at least one material selected from a PU (PolyUreathane) resin, an acrylic resin, a melamine resin, an epoxy resin, and a polyester resin. The method of claim 1, And wherein the fourth step is performed before the fifth step. The method of claim 1, The provisional hardening of the third step is performed at 30 to 80 ° C. The partition wall forming method of the plasma display panel. The method of claim 1, And a step 2-1 of removing the photosensitive partition wall paste protruding from the soft mold between the second step and the third step. The method of claim 1, The photosensitive partition wall paste may contain 50 to 70% by weight of inorganic partition material powder, 10 to 30% by weight of binder polymer, 10 to 30% by weight of polyfunctional monomer or oligomer, 1 to 3% by weight of photoinitiator, 0.5 to 2% by weight of release agent, and the remaining amount. A partition wall forming method for a plasma display panel, comprising a solvent. The method of claim 1, Step 7-1 to demold the soft mold after the sixth step; And And a seventh step of performing a step of firing the partition wall for cooling after stopping for 30 minutes at 350 to 380 ° C for 30 minutes at a temperature increase rate of 5 to 10 ° C / min, and stopping for 30 minutes at 550 to 580 ° C. A partition wall formation method of a plasma display panel. delete The method of claim 1, The method of forming a partition of the plasma display panel, wherein the back substrate temperature is maintained at a temperature of 30 ° C. to 80 ° C. during the press molding of the sixth step, and the ultraviolet light is exposed to the photosensitive partition wall paste. The method of claim 1, The photosensitive barrier rib paste is filled with a thickness of 100 to 250㎛ partition wall forming method of the plasma display panel. The method of claim 1, And the photosensitive barrier rib paste has a viscosity of 1000 to 4000 cps.

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