KR20040011998A - Fabrication method of base mold frame for fabrication of additive soft mold for barrier rib in plasma display panel, fabrication method of soft mold using the basic mold frame and method of forming barrier rib using the soft mold - Google Patents

Abstract

PURPOSE: A base mold frame manufacturing method, a soft mold manufacturing method and a barrier rib forming method are provided to achieve improved durability and reduce manufacturing procedures and costs. CONSTITUTION: A base mold frame manufacturing method comprises a step of preparing a photosensitive glass(50); a step of exposing the photosensitive glass into a predetermined depth by using a photo mask(51); a step of performing a heat treatment on the photosensitive glass; and a step of removing the exposed area of the photosensitive glass by using the difference of etching characteristics between the exposed area and the unexposed area which have different structures after the heat treatment performed in the previous step.

Description

Basic mold making method for fabricating soft mold for forming partition wall of plasma display panel, soft mold manufacturing method using same and partition wall forming method using same {Fabrication method of base mold frame for fabrication of additive soft mold for barrier rib in plasma display panel , fabrication method of soft mold using the basic mold frame and method of forming barrier rib using the soft mold}

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 base mold frame manufacturing technology for manufacturing a soft mold for forming barrier ribs of a PDP. will be.

The plasma display panel (PDP) is a display element for displaying an image by using a plasma generated during 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.

PDP is divided into direct current (DC) type and alternating current (AC) type, and AC type is divided into counter discharge type and surface discharge type according to the electrode structure of discharge cell, and the opposite discharge type is due to phosphor deterioration due to ion shock. While there is a problem of shortening the lifespan, the surface discharge type overcomes the problem of the opposite structure by collecting discharges on opposite sides of the phosphor and minimizing phosphor degradation, and most PDPs adopt this method.

1 is a cross-sectional view of a surface discharge type AC PDP.

Referring to FIG. 1, in the surface discharge type AC PDP, a back substrate 10, an address electrode 11, a white dielectric 12, a partition 13, and the like form a back substrate, the front substrate 14, and the transparent electrode 15. ), The bus electrode 16, the transparent dielectric 17, the dielectric protective film 18, a black stripe (not shown), and the like form a front plate. In addition, phosphors R, G, and B 19 for realizing color in the PDP are disposed on the front plate in the case of a transmissive type and between partition walls 13 of the back plate in the case of a reflective type.

Among these, the partition wall has a three-dimensional structure with a line width of about 100 to 120 µm, which makes the formation process difficult. Currently, PDP bulkhead formation process includes 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 height of the partition wall formed by one printing is approximately 15 to 25 µm, this screen printing method requires printing and drying several times repeatedly until the desired partition height (100 to 200 µm) is obtained. Problems such as slanting of barrier ribs, instability of discharge characteristics due to height deviations of barrier ribs, uniformity reduction in forming phosphors, and screen mask mesh traces are pointed out as problems, and yield decreases due to poor reproducibility are expected. Due to the limitation of the high-precision pattern manufacturing is a disadvantage that is quite difficult.

The sand blasting method is to apply a barrier paste to a thickness of 300 to 400 μm, and then to laminate a photosensitive polymer film (commonly referred to as DFR (dry film resist)) having sanding resistance, and to expose and develop the same. The desired barrier pattern is obtained and then 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 with a developer. Such photolithography has the advantage of being able to precisely adjust the dimensions, while the loss of the paste is large and the photoresist is difficult to form down to the lower part of the photosensitive partition paste. have.

2A to 2C are diagrams illustrating a barrier rib forming process using a mold method according to the related art. In the mold method according to the related art, first, as shown in FIG. 2A, a green tape 21 including a partition forming material is attached onto a glass substrate 20, and then the plate pattern is engraved. The metal mold 22 is aligned on the green tape 21.

Next, pressure molding is performed as shown in FIG. 2B.

Subsequently, as shown in FIG. 2C, the plate-shaped metal mold 22 is separated in the vertical direction to form the partition wall 21a.

The conventional mold method as described above has the advantage that the process is very simple and the material utilization is high, while the height uniformity of the obtained partition wall 21a is lowered and the pressure applied to the large-area plate-shaped metal mold 22 is reduced. Due to this, there is a concern that the glass substrate 20 may be damaged, and it is difficult to separate (deform) between the plate-shaped metal mold 22 and the green tape 21 after pressure molding.

On the other hand, LTCC-M (Low Temperature Co-fired Ceramic on Metal) method is attached to a green sheet containing a partition forming material on a metal substrate (eg Ti), the address electrode and the dielectric layer on the green sheet After the formation of the mold, it is a step of forming a barrier rib by press molding with an embossing mold, which is a plate-shaped metal mold. The LTCC-M method can solve the alignment problem because there is almost no shrinkage in the horizontal direction during heat treatment, and the process is simpler than the screen printing method, and the equipment and material costs can be reduced, but in order to be applied to mass production of PDP, Technical matters such as securing ease of post-molding, restraining warp during simultaneous firing, and preventing warpage of the back substrate during press molding should be solved.

In order to solve the problems of the existing barrier rib forming process, a barrier rib forming method using a soft mold has been proposed (see Korean Patent Application Nos. 10-2001-0051454 and 10-2001-0051457).

3a to 3e is a soft mold manufacturing process according to the prior art.

In the buried soft mold fabrication process according to the prior art, first, a silicon-based coupling agent 31 such as Z-6040, manufactured by Dow-Corning, is formed on a metal substrate 30 or a glass substrate surface such as copper or nickel, as shown in FIG. 3A. It is applied to a thickness of 0.1 to 0.2㎛.

Next, as shown in FIG. 3B, a spin resist (900 rpm, 30 sec) of a photoresist 32 (for example, SU 8 of Microchem), which is easy to form a thick film of 300 μm or more, is dried and dried (90 ° C./20 min). Carry out the process.

Subsequently, an exposure (360-420 nm exposure source, 600-1000 mJ / cm ² exposure energy) process is performed using a photomask on which a partition pattern is drawn as shown in FIG. 3C, and development is performed to prepare a basic mold. .

Subsequently, as shown in FIG. 3D, a liquid room temperature-curable transparent silicone rubber raw material 33 (for example, silicone resin solution: hardener = 5 to 15: 1) or a urethane rubber raw material is placed in a basic mold in a vacuum casting machine. Inject, remove bubbles, and cure in oven at about 80 ° C. for about 5 minutes.

Next, the soft mold 34 is obtained by separating the cured room temperature type transparent silicone rubber from the basic mold as shown in FIG. 3E.

The partition wall is formed by pressing the partition wall paste in the same manner as the conventional mold method using the soft mold 34 as described above, and then demolding the roll in the manner of rolling up the soft mold 34.

Meanwhile, FIG. 4 is a plan view of a buried soft mold manufactured by performing an additional process on the soft mold 34 shown in FIG. 3E. The soft mold is formed such that the partition pattern of the soft mold 34 is exposed to form a through hole. When the back surface 34 is polished, the embedded soft mold 40 can be manufactured. In the case of using the buried soft mold 40, the buried soft mold 40 is aligned on the substrate, and the partition paste is embedded into the buried soft mold 40 by using a squeeze, followed by demolding.

When using a soft mold as described above, there is an advantage that the process is simple as in the conventional mold method, there is no fear of damage to the glass substrate during pressure molding because it uses a soft mold rather than a metal, demoulding due to the elasticity of the mold This has the advantage of being easy and ensuring the uniformity of the height of the partition wall.

Meanwhile, as a result of repeating the soft mold forming process shown in FIGS. 3D and 3E three to four times using the basic mold obtained through the process shown in FIGS. 3A to 3C, the weak bonding force between the glass and the photoresist was observed. And due to the strong adhesion of the silicone resin and the photoresist pattern is lost or dropped occurs. In addition, it was difficult to obtain a uniform high-definition pattern because the network structure of the polymer formed on the exposed portion at the time of developing the unexposed portion of the photoresist penetrated the non-exposed portion.

That is, the prior art as described above has a disadvantage in that the durability of the basic mold is inferior and it is difficult to make a high definition because it uses a photoresist and a metal as the pattern material in forming the basic mold for manufacturing the soft mold. If the new mold is newly manufactured, additional costs are incurred, and if the change of the mold has a significant effect on the subsequent process, it is likely that the subsequent process should be set again.

The present invention is proposed to solve the problems of the prior art as described above, the basic mold for fabricating the soft mold for forming the partition wall of the plasma display panel that can ensure the durability and high definition of the basic mold for the soft mold manufacturing The purpose is to provide a method of making a frame.

1 is a cross-sectional view of a surface discharge type AC PDP.

Figure 2a to 2c is a partition wall forming process using a mold method according to the prior art.

3a to 3e is a soft mold manufacturing process according to the prior art.

4 is a plan view of a buried soft mold manufactured by performing an additional process on the soft mold shown in FIG. 3E.

5a to 5d is a basic mold frame manufacturing process for producing a soft mold according to an embodiment of the present invention.

6A to 6C are diagrams illustrating a process of fabricating a soft mold for forming a partition wall of a PDP using the basic mold shown in FIG. 5D.

7A to 7D are diagrams illustrating a process for forming barrier ribs of a PDP using the soft mold shown in FIG. 6C.

* Explanation of symbols for the main parts of the drawings

50: photosensitive glass

50a: exposure area

50b: non-exposed area

60: basic mold

70: soft mold

According to an aspect of the present invention for achieving the above technical problem, preparing a photosensitive glass; Exposing the photosensitive glass to a predetermined depth using a barrier mask; Heat treating the photosensitive glass; And removing an exposed region of the photosensitive glass by using an etching characteristic difference between an exposed region and a non-exposed region, the microstructure of which is changed by the heat treatment, to form a basic mold for fabricating a soft mold for forming a partition wall of the plasma display panel. A manufacturing method is provided.

In addition, according to another aspect of the present invention, in the method of manufacturing a soft mold for forming the partition wall of the plasma display panel using a basic mold for the production of the soft mold for forming the partition wall of the plasma display panel manufactured according to the above production method, Applying a release agent to the base mold; Injecting a liquid rubber raw material into the base mold; Curing the rubber raw material; And separating the cured rubber raw material from the basic mold frame, thereby providing a soft mold for forming a partition wall of the plasma display panel.

According to still another aspect of the present invention, a method of forming a partition wall of a plasma display panel using a soft mold for forming a partition wall of a plasma display panel manufactured according to the above manufacturing method, the method comprising: applying a partition paste on a substrate; Pressure molding the partition paste with the soft mold; And separating the soft mold from the substrate, thereby providing a soft mold for forming a partition wall of the plasma display panel.

In the present invention, a photosensitive glass is exposed and heat-treated using a partition mask (for example, a photo mask having a pattern having a polarity opposite to the partition pattern), and a basic mold is manufactured by etching the exposed portion by a predetermined depth. The basic mold manufactured as described above is advantageous in securing durability and miniaturization as well as the basic mold using the conventional photoresist and metal, and has a relatively simple manufacturing process.

Hereinafter, the following comparative examples will be introduced in order to enable those skilled in the art to more easily implement the present invention.

5a to 5d is a basic mold manufacturing process diagram for manufacturing a soft mold according to an embodiment of the present invention.

The manufacturing process of the basic mold using photosensitive glass is very similar to the photolithography process using a conventional photoresist except for the high temperature heat treatment process. That is, exposure, heat treatment, and etching are performed.

In the basic mold forming process according to the present embodiment, first, the photosensitive glass 50 is prepared as shown in FIG. 5A. As the photosensitive glass 50, Schott's Foturan, Hoya's PEG3, and the like may be used, and it is preferable to perform ultrasonic cleaning by repeating three times each of acetone, ethanol, and distilled water for three minutes.

Next, as illustrated in FIG. 5B, ultraviolet (UV) exposure is performed using an energy of 2J / cm 2 using a photomask 51 on which a pattern having a polarity opposite to a desired partition pattern is drawn. At this time, by changing the angle of the light source in a predetermined direction it is possible to adjust the profile of the final pattern structure (for example, semi-box type).

Subsequently, a high temperature heat treatment is performed on the photosensitive glass 50 having undergone the exposure process as shown in FIG. 5C. At this time, the high temperature heat treatment is maintained at 50 to 70 minutes after the temperature is raised to 480 to 520 ℃ at a temperature increase rate of 5 to 8 ℃ / min, and maintained for 50 to 70 minutes after the temperature is raised to the same temperature increase rate up to 580 to 620 ℃ Then, it is preferably carried out in a manner of cooling to room temperature. By this heat treatment, the photosensitive glass 50 of the non-exposed area 50b is crystallized. Reference numeral 50a of the description indicates an exposure area.

Subsequently, as shown in FIG. 5D, the 10% hydrofluoric acid (HF) solution was used to etch the exposed area 50a of the photosensitive glass to a depth of 180 to 200 μm, which is the required height before firing the partition walls, and then distilled water was removed. Remove the etching liquid on the photosensitive glass 50 through the used cleaning, dry for 10 minutes at 110 ℃, and then laser annealing, polishing, metal coating treatment to improve the flatness and wear resistance of the surface Etc. to complete the basic mold 60 for soft mold production. Here, the ultrasonic effect may be applied during the wet etching to increase the etching effect.

The photosensitive glass 50 is added with a trace amount of refined impurities (lithium-aluminum silicate series) to have photosensitivity. The small amount of impurities plays a very important role in the microstructure change of the photosensitive glass 50 in the exposure process and the heat treatment process. That is, when exposure and heat treatment are performed on the photosensitive glass 50, the microstructures of the exposure area 50a and the non-exposure area 50b are changed, so that the etching characteristics of the etchant may be changed during the subsequent etching process.

The basic mold for fabricating the soft mold for forming the partition wall of the PDP manufactured through the above process is made of the substrate and the pattern integrally, so that the basic mold is fabricated using the existing photoresist and metal in the durability and high resolution screen. Superior to the framework In addition, in the case of manufacturing a basic mold using a photoresist, a silicon coupling agent should be used for adhesion of the substrate and the photoresist, but the present invention does not require a separate coupling agent.

6A to 6C are diagrams illustrating a process of fabricating a soft mold for forming a partition wall of a PDP using the basic mold 60.

In the soft mold fabrication process for forming the partition wall of the PDP using the basic mold of the present invention, first, a release agent 61 is applied onto the basic mold 60 as shown in FIG. 6A. The mold release agent is used to facilitate demolding of the soft mold from the basic mold mold 60. Zn stearate, dimethyl silicone resin, organic or silicone mold release agent may be used.

Next, as shown in FIG. 6B, the rubber solution 62 is injected and bubbles are removed three times in a vacuum molder, and then cured in an oven at a temperature of about 50 ° C. for about 30 minutes. At this time, the rubber solution 62 may be a silicone solution such as SYLGARD 184 or SH9555 (a solution in which a silicon sol and a curing agent are mixed), a urethane rubber solution, or the like.

Subsequently, the cured rubber is demolded from the base mold 60 as shown in FIG. 6C to obtain a soft mold 70 for forming a partition.

7A to 7D are diagrams illustrating a process of forming barrier ribs of the PDP using the soft mold 70.

In the PDP partitioning process shown, first, the partition paste 81 is applied on the back substrate 80 to a thickness of 200 to 300 µm as shown in FIG. 7A, and then in the partition paste 81 in a drying oven. Remove 70% to 80% of the solvent.

Next, as shown in FIG. 8B, the soft mold 70 is aligned on the partition paste 81, and pressure molding is performed at a temperature of 30 to 80 占 폚.

Subsequently, as shown in FIG. 7C, the soft mold 70 is gradually rolled up as if the contact surface between the crimped bulkhead paste 81 a and the soft mold 70 is reduced at a constant speed from the edge of the soft mold 70. Demold.

Subsequently, as shown in FIG. 7D, a firing process is performed at a temperature of 500 to 580 ° C. to remove organic components in the partition paste 31, and only the inorganic partition material is left to leave the partition wall 81b having a height of 110 to 130 μm. To obtain.

Meanwhile, when the back polishing process is further performed on the soft mold 70 illustrated in FIG. 6C, a buried soft mold may be manufactured, and a partition wall may be formed by a buried method using the buried soft mold.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

For example, in the above-described embodiment, the case of using ultraviolet (UV) as an exposure source of photosensitive glass has been described as an example, but the present invention is also applied to the case of using a light source of another wavelength band as the exposure source.

The present invention described above can secure the durability and high-definition of the basic mold for soft mold production, thereby reducing the soft mold production cost can be expected to achieve the effect of high-definition of the partition wall pattern.

Claims (10)

Preparing a photosensitive glass; Exposing the photosensitive glass to a predetermined depth using a barrier mask; Heat treating the photosensitive glass; And Removing the exposed area of the photosensitive glass by using a difference in etching characteristics between the exposed area and the non-exposed area where the microstructure is changed by the heat treatment. Basic mold production method for producing a soft mold for forming a partition wall of the plasma display panel comprising a. The method of claim 1, After performing the step of removing the exposure area of the photosensitive glass, Wet cleaning the photosensitive glass; The method of claim 1, further comprising the step of drying the photosensitive glass after the wet cleaning. The method of claim 1, After performing the step of removing the exposure area of the photosensitive glass, And performing at least one selected from laser annealing, polishing, and metal coating on the photosensitive glass. The method of claim 1, Preparing the photosensitive glass, Method for manufacturing a basic mold for fabricating the soft mold for forming the partition wall of the plasma display panel, characterized in that for performing the ultrasonic cleaning using acetone, ethanol, distilled water for the photosensitive glass, respectively. The method of claim 1, The photosensitive glass is a basic mold manufacturing method for manufacturing a soft mold for forming the partition wall of the plasma display panel, characterized in that the lithium-silicate silicate-based impurities are added. The method according to claim 1 or 5, The heat treatment of the photosensitive glass, Firstly raising the temperature from room temperature to 480 to 520 ° C. at a temperature rising rate of 5 to 8 ° C./min; Maintaining for 50 to 70 minutes while the primary temperature is completed; Secondly warming up to 580-620 ° C. at a rate of 5-8 ° C./min; Maintaining for 50 to 70 minutes while the secondary temperature is completed; And A method of fabricating a basic mold for fabricating a soft mold for forming a partition wall of a plasma display panel, the method comprising the step of cooling to room temperature. The method of claim 6, In the step of removing the exposure area of the photosensitive glass, A method of fabricating a basic mold for fabricating a soft mold for partition wall formation of a plasma display panel, wherein the etching is performed using a hydrofluoric acid solution. The method of claim 5, Exposing the photosensitive glass to a predetermined depth; A method for fabricating a basic mold for fabricating a soft mold for partition wall formation of a plasma display panel, characterized by using ultraviolet rays as an exposure source. In the method of manufacturing a soft mold for forming a partition wall of a plasma display panel using a basic mold for manufacturing a soft mold for forming a partition wall of a plasma display panel manufactured according to claim 1, Applying a release agent to the base mold; Injecting a liquid rubber raw material into the base mold; Curing the rubber raw material; And Separating the cured rubber stock from the base mold Soft mold manufacturing method for forming the partition wall of the plasma display panel comprising a. In the method of forming a partition of a plasma display panel using a soft mold for forming a partition of a plasma display panel manufactured according to the method of claim 9, Applying a partition paste on the substrate; Pressure molding the partition paste with the soft mold; And Separating the soft mold from the substrate Soft mold manufacturing method for forming the partition wall of the plasma display panel comprising a.