JP4175459B2 - Partition wall forming method for plasma display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming barrier ribs for a plasma display panel for forming fine barrier ribs of display cells on a substrate in a plasma display panel manufacturing process.
[0002]
[Prior art]
As shown in the perspective view of FIG. 2, the basic configuration of the plasma display panel is such that the front substrate 1 and the rear substrate 2 are opposed to each other by strip electrodes 3 and 4 formed on both substrates at right angles. Thus, light is emitted by causing discharge in the stripe-shaped or grid-shaped partition walls 5 formed on the back substrate 2 at the intersection. The partition wall 5 is required to have a very fine structure. For example, in the case of a stripe-shaped structure, a large screen plasma display having a height of 100 to 150 μm and a width of several tens of μm has a diagonal dimension of 40 to 60 inches. It is required to be formed over the entire surface of the rear substrate.
[0003]
Various methods have been implemented for the partition wall forming method. For example, a screen printing method in which a dielectric paste serving as a partition wall is repeatedly screen-printed to a predetermined height and fired, or a dielectric paste is applied to a predetermined thickness and dried, and then the surface is exposed to light. Patterning with a photosensitive resist and removing the unnecessary part by sandblasting, or a sandblasting method, forming a groove pattern in the photosensitive resist, embedding and drying the dielectric paste in the groove, and then removing the photosensitive resist An embedding method has been put to practical use.
[0004]
However, in the screen printing method, since the screen printing must be repeated many times, the screen is deformed and needs to be aligned every time. Is difficult to form at low cost and with high accuracy. In the sand blasting method, the partition walls are patterned by a photolithography technique and can be formed with high accuracy. However, since the number of processes is large and about 2/3 of the material is consumed, it is wasteful and it is difficult to reuse the material, resulting in high cost. Similarly, the photo embedding method has a large number of steps, and it is difficult to embed a dielectric paste in a narrow gap groove, and it is difficult to cope with the formation of finer partition walls.
[0005]
Therefore, in order to reduce the manufacturing cost and the number of steps, a method called a pressure molding method has been proposed (see, for example, Patent Document 1). In this method, as an example, as shown in the cross-sectional view of FIG. 3A, a mold 6 having a recess that matches the shape of the partition is prepared, and a material for forming the partition is formed in the recess of the mold 6. A mixture of ceramics or glass powder and a solvent and a binder of an organic additive (hereinafter referred to as green sheet 7) is filled. On the other hand, the back substrate 2 made of ceramics or glass is separately prepared, and the green sheet 7 molded body is joined and integrated with the back substrate 2 to form the partition walls.
[0006]
Specifically, the back substrate 2 is pressed against the surface of the green sheet 7 filled in the mold 6 and pressure-bonded, and the green sheet 7 is dried and solidified. After that, as shown in the cross-sectional view of FIG. 3B, the partition 6 made of the green sheet 7 is transferred and formed on the back substrate 2 by releasing the molding die 6 upside down. Is.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 09-134676 (FIG. 2)
[0008]
[Problems to be solved by the invention]
However, the conventional pressure molding method described above has the following problems. First, the back substrate made of ceramics or glass has a large area of 40 inches or more, and substrate deformation such as undulation or unevenness is likely to exist. For this reason, it is difficult to press the mold uniformly against the mold, and the green sheet filled in the mold cannot be completely transferred.
[0009]
In addition, since the following ability of the mold against the substrate deformation is difficult, the green sheet enters the gap between the back substrate and the mold, and the film thickness of the overcoat portion does not become zero. There is.
[0010]
In addition, a molding die for pressure-molding a fine partition wall must be processed with a large number of grooves having a depth of 100 to 150 μm and a width of several tens of μm, and a molding die corresponding to an increase in the area of the back substrate can be used. It is not easy to manufacture with high precision by machining, and there is a problem that it is expensive.
[0011]
The present invention has been made in order to solve the above-described problems, eliminates the difficulty of processing in the production of a mold and realizes cost reduction, and allows fine partition walls to be formed on a large area plasma display panel with a high yield. An object is to provide a method for forming a partition wall.
[0012]
[Means for Solving the Problems]
The present invention relates to a method for forming a partition for a plasma display panel, in which a mold for forming a partition is filled with a green sheet and the partition is formed by transferring the green sheet to a rear substrate. The process of installing in the order of flat plate type, the back substrate is stacked on the flat plate type, the press load is applied from above the back substrate, the flat plate type is pushed down, and the through hole provided in the flat plate type is filled with the green sheet And a step of stopping the press when the filled green sheet comes into close contact with the back substrate, lifting the back substrate to peel off the green sheet filled in the flat plate, and transferring the green sheet to the back substrate It is a forming method.
[0013]
In the present invention, the flat plate mold has a partition wall forming method in which a plurality of through holes are formed in a single plate, and a green sheet is filled into the long holes to form a partition wall. According to the present invention, when the green sheet filled in the flat plate mold is peeled off by lifting the back substrate, the green sheet is separated from the flat plate mold in advance so that the adhesion strength of the green sheet to the flat plate mold is larger than that of the flat plate mold. This is a method of forming a partition that has been subjected to mold surface treatment. Also, the green sheet is pulled out from the flat plate mold and transferred to the back substrate due to the difference between the adhesion force of the green sheet to the back substrate and the adhesion to the flat plate mold. This is a method for forming a partition.
[0014]
Further, the present invention provides a partition wall in which the thickness of the green sheet is formed to be greater than the thickness of the flat plate type, and the flat plate type is separated from the release sheet even if the green sheet is in close contact with the back substrate by pressing. The present invention is also a partition wall forming method in which a green sheet is brought into close contact with a back substrate by the flat plate mold and a press, and the green sheet is transferred to the back substrate.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of a partition wall forming method according to the present invention in the order of steps (a), (b), (c), and (d).
[0016]
First, as shown in FIG. 1A, a base 8 having a strong and smooth surface is installed horizontally. A release sheet 9 is placed on the base 8. This release sheet 9 may be one generally used as a release material. Next, a green sheet 7 as a partition material is placed thereon. The green sheet 7 is obtained by processing a mixture of ceramics or glass powder and a binder of a solvent and an organic additive into a plate shape. The thickness of the green sheet 7 is formed to be slightly thicker than the thickness of the flat plate mold 10 placed thereon. Next, a flat plate mold 10 serving as a partition mold is placed on the green sheet 7. This flat plate mold 10 is a single metal plate having a thickness of about 100 to 150 μm formed with a large number of fine long holes 11 having a width of about several tens of μm. Compared with the groove processing in a conventional mold, Since it is sufficient to provide a through hole, processing is easy.
[0017]
Next, the back substrate 2 is placed on the flat plate mold 10 as shown in FIG. Then, with the release sheet 9, the green sheet 7, the flat plate mold 10, and the back substrate 2 stacked on the base 8, a press load is gradually applied so that pressure is evenly applied to the entire surface from above.
[0018]
Next, as shown in FIG. 3C, the flat plate mold 10 starts to sink into the green sheet 7 as the press load is applied, and the long holes 11 of the flat plate mold 10 are filled with the green sheet 7. The press is completed when the entire long hole 11 is filled with the green sheet 7. At this time, since the thickness of the green sheet 7 is larger than the thickness of the flat plate mold 10, the flat plate mold 10 does not penetrate the green sheet 7 and reach the release sheet 9 below it.
[0019]
Next, as shown in FIG. 4D, after the press is completed, the rear substrate 2 is lifted. At this time, the adhesion to the green sheet is in the relationship of the back substrate >> the flat plate inner wall or the release sheet, and the adhesion to the back substrate is the strongest. This difference in adhesion is obtained by the difference in surface roughness between the back substrate and the flat plate type, or by applying a release agent to the flat plate type or making the inner wall a tapered structure. This is realized by subjecting to a mold release surface treatment and providing a relative difference in adhesion between the green sheet and the green sheet. As a result, simultaneously with lifting the back substrate 2, the green sheet 7 is peeled off from the flat plate mold 10, and the partition 5 formed by the green sheet 7 is transferred to the back substrate 2. In addition, since there is a release sheet 9 under the green sheet 7, the adhesion with the green sheet 7 is extremely weak and can be easily peeled when the back substrate 2 is lifted. Next, the back substrate 2 on which the green sheets 7 are transferred to form the partition walls 5 is baked to complete the formation of stripe-shaped partition walls.
[0020]
【The invention's effect】
As described above, according to the present invention, the rear substrate is placed on the green sheet and the flat plate, and the partition wall can be formed by a simple method of simply applying a pressing pressure. High productivity can be obtained with less man-hours.
[0021]
Also, even if the back substrate has undulations or irregularities due to deformation, the flat plate type is a thin single plate, so that the followability to the substrate deformation is improved, and the green sheet is completely transferred to the back substrate. Therefore, the occurrence of defects in the partition walls can be prevented.
[0022]
In addition, since a mold for pressure-molding a fine partition wall is a flat plate that is a single plate, conventionally, a large number of grooves having a depth of 100 to 150 μm and a width of about several tens of μm have to be processed. Compared to the above, since it suffices to punch a long hole, machining becomes easy, and it can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a process diagram illustrating an embodiment of the present invention.
FIG. 2 is a perspective view showing an example of a plasma display panel structure.
FIG. 3 is a cross-sectional view illustrating a conventional partition wall forming method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front substrate 2 Back substrate 3, 4 Strip electrode 5 Partition wall 6 Mold 7 Green sheet 8 Base 9 Release sheet 10 Flat plate 11 Slot

Claims (6)

In a method for forming a partition for a plasma display panel in which a green sheet is filled in a mold for forming a partition, and the partition is formed by transferring the green sheet to a back substrate, a release sheet, a green sheet, and a flat plate are formed on a base. A step of stacking in order, a step of stacking a back substrate on a flat plate, a step of applying a press load from the back substrate to push down the flat plate, and filling a through hole provided in the flat plate with a green sheet; When the filled green sheet comes into close contact with the back substrate, the press is stopped, the back substrate is lifted, the green sheet filled in the flat plate mold is peeled off, and the green sheet is transferred to the back substrate. A method for forming partition walls for a plasma display panel. 2. The barrier rib formation for a plasma display panel according to claim 1, wherein a plurality of through holes are formed in a single plate and a partition is formed by filling the elongated holes with a green sheet. Method. When the back substrate is lifted and the green sheet filled in the flat plate mold is peeled off, the release surface treatment is applied to the flat plate mold in advance so that the adhesion force of the green sheet to the back substrate is larger than the adhesion force with the flat plate mold. The method for forming a partition for a plasma display panel according to claim 1, wherein: When the back substrate is lifted and the green sheet filled in the flat plate is peeled off, the green sheet is pulled out of the flat plate due to the difference between the adhesion of the green sheet to the back substrate and the adhesion to the flat plate, and transferred to the back substrate. The method for forming a partition for a plasma display panel according to claim 1. The thickness of the green sheet is formed to be thicker than the thickness of the flat plate mold, and the flat plate mold is separated from the release sheet even if the green sheet is in close contact with the back substrate by pressing. A method for forming partition walls for a plasma display panel. 2. The method for forming a partition for a plasma display panel according to claim 1, wherein a green sheet is brought into close contact with the rear substrate by the flat plate mold and a press, and the green sheet is transferred to the rear substrate.

Images