KR20090103079A - Plasma display panel and manufacturing method therefor - Google Patents

Abstract

The present invention relates to a plasma display panel capable of reducing noise caused by a gap between a top plate and a bottom plate, and a method of manufacturing the same. Plasma display panel of the present invention is arranged to face each other at a predetermined interval across the partition wall and is disposed in the long side portion between the top plate and the lower plate to seal the discharge space partitioned by the partition and the upper plate and lower plate having a long side portion and a short side portion; A first sealing material and a second sealing material disposed on the short side portion, a first spacer inserted into the first sealing material, and a second spacer inserted into the second sealing material and smaller than the first spacer, the first sealing material and the second sealing material The groove is provided in at least one of the upper plate and the lower plate of the portion where the overlaps.

Description

Plasma display panel and manufacturing method therefor

The present invention relates to a plasma display panel and a method for manufacturing the same, which can reduce noise due to a nonuniform spacing between an upper plate and a lower plate.

Plasma display panels (PDPs) typically include a front plate with XY electrodes, dielectrics and MgO films disposed on a transparent substrate, and address electrodes, dielectrics, barrier ribs and phosphors disposed on another substrate. And a back plate provided. The upper plate and the lower plate are disposed to face each other at a predetermined interval by the partition wall. In addition, the plasma display panel applies a signal to the address electrode and the Y-electrode through the mounted control circuit to select a discharge cell for emitting light, and alternately applies a signal to the X-electrode and the Y-electrode to generate a still image or a moving picture. Display. The X-electrode, the Y-electrode and the address electrode are driven by the control circuit.

In the above-described plasma display panel, during the process of sealing the upper plate and the lower plate, warpage may occur in the panel due to a difference in shrinkage of the partition and / or the sealing material, or an unnecessary gap may occur between the upper plate and the lower plate of the panel. The unnecessary gap here makes the gap between the top and bottom panels of the panel uneven. This gap is one of the noise generating elements in the panel. In particular, the gap formed in the dummy area portion of the panel after the sealing process of the panel is one of the main causes of the panel noise.

The technical problem of the present invention is to provide a method of manufacturing a plasma display panel that can prevent noise caused by non-uniform spacing between the upper and lower plates.

Another technical problem of the present invention is to manufacture a plasma display panel capable of preventing adverse effects due to the difference in shrinkage of the long and short sides of the panel during the sealing / exhaust of the upper and lower plates using a sealing material such as a frit. To provide a way.

According to an aspect of the present invention for solving the above problems, the upper plate and the lower plate facing each other at a predetermined interval with a partition therebetween having a long side and a short side; A first sealant disposed on the long side portion between the upper plate and the lower plate and a second sealant disposed on the short side portion to seal the discharge space partitioned by the partition wall; A first spacer inserted into the first sealing material; And a second spacer inserted into the second sealing material and smaller in size than the first spacer. Here, the groove is provided in at least one of the upper plate and the lower plate of the portion where the first sealing material and the second sealing material overlap.

According to another aspect of the present invention, the method comprising the steps of: preparing a first sealant mixed by adding a first spacer to a sealing material; Preparing a second sealing material in which a second space smaller in size than the first spacer is added to the sealing material and mixed; Preparing an upper plate and a lower plate each having a long side portion and a short side portion and facing each other at predetermined intervals with partition walls therebetween; Forming a groove in a portion where the first sealing material and the second sealing material overlap at least one of the upper plate and the lower plate; Applying a first sealant to a long side of at least one of the upper and lower plates and a second sealant to the short side; And a step of aligning and sealing the upper plate and the lower plate.

The volume of the first spacer is 10% or less than the size of the second spacer.

According to the present invention, in the manufacture of a plasma display panel, by equalizing the distance between the top plate and the bottom plate, it is possible to reduce the noise caused by the unwanted gap between the top plate and the bottom plate and to improve the quality of the panel.

1 is an exploded perspective view for explaining a plasma display panel of the present invention.

2 is a cross-sectional view of a long side portion of a plasma display panel according to a comparative example.

3A and 3B are plan views illustrating the structure before and after the sealing step of the plasma display panel of the present invention;

4A is a partial cross-sectional view of a long side portion of the plasma display panel of FIG. 3B.

4B is a partial cross-sectional view of a short side portion of the plasma display panel of FIG. 3B.

5A to 5C are cross-sectional views illustrating a plasma display panel according to still another embodiment of the present invention.

6A is a graph illustrating a noise measurement result of a plasma display panel according to a comparative example.

Figure 6b is a graph of the noise measurement results of the plasma display panel of the present invention.

<Description of the symbols for the main parts of the drawings>

10: top plate 11: substrate

12: X-Y electrode 12a, 12b: transparent electrode

13a, 13b: bus electrode 14: black layer

15, 23: dielectric layer 16: protective film

20: lower plate 21, 21 ': substrate

21a: groove 22: address electrode

24: partition 25: phosphor layer

30, 30 ': sealing material

30a: sealing member disposed on the long side portion (first sealing member)

30b: Sealing material disposed on the short side (second sealing material)

31: first spacer 32: second spacer

A: Long side B: Short side

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is an exploded perspective view illustrating a plasma display panel of the present invention.

Referring to FIG. 1, the plasma display panel includes a front plate 10 and a back plate 20 disposed to face each other. The upper plate 10 includes the transparent electrodes 12a and 12b, the bus electrodes 13a and 13b, the black layer 14, the first dielectric layer 15, and the passivation layer 16 formed on the transparent first substrate 11. The lower plate 20 includes an address electrode 22, a second dielectric layer 23, a partition wall 24, and a phosphor layer 25 formed on the second substrate 21. In addition, although not shown in FIG. 1, the plasma display panel includes a sealing material for sealing the upper plate 10 and the lower plate 20, and a spacer mixed with the sealing material.

Plasma display panel of the present embodiment has a different size depending on the position of the sealing material so that the gap nonuniformity between the upper plate 10 and the lower plate 20 according to the difference in the shrinkage rate of the sealing material that may occur in the sealing process of the panel does not occur or decrease. It is a main feature to have a spacer. In addition, the main feature is to have a substrate having grooves that can prevent height unevenness that may occur in overlapping portions of the sealing materials in which different sizes of spacers are mixed. The sealant and the spacer will be described in detail below.

Specifically, each component of the panel will be described in detail. The transparent electrodes 12a and 12b are electrodes for generating and maintaining a discharge. The transparent electrodes 12a and 12b may be formed of a transparent material having high visible light transmittance, for example, ITO, SnO ₂ , ZnO, CdSnO, or the like.

The bus electrodes 13a and 13b are electrodes for compensating for large resistance values of the transparent electrodes 12a and 12b, and are usually arranged in a narrower width than the transparent electrodes 12a and 12b. The bus electrodes 13a and 13b are formed of a material having low electrical resistance and not reacting with the first dielectric layer 15. As the material of the bus electrodes 13a and 13b, gold (Au), silver (Ag), or the like is applicable.

Each pair of the above-mentioned one transparent electrode 12a and one bus electrode 13a and the other transparent electrode 12b and the other bus electrode 13b is an XY electrode pair (hereinafter referred to as an XY electrode). To form.

The black layer 14 is disposed between one X-Y electrode and another X-Y electrode adjacent to the X-Y electrode to improve contrast. The black layer 14 is formed of a material having a very low visible light transmittance and a high external light absorbance.

The first dielectric layer 15 limits discharge current, maintains glow discharge, and accumulates wall charge. The first dielectric layer 15 may be formed of a material having a high withstand voltage and a high visible light transmittance. As the material of the first dielectric layer 15, PbO-B ₂ O ₃ -SiO ₂ or Bi ₂ O ₃ can be used. The first dielectric layer 15 is usually formed in a two-layer structure to have a uniform surface and a thickness of a predetermined size or more, but may be formed through a printing technique even in a single layer or a multilayer structure of three or more layers.

The protective film 16 is disposed on the first dielectric layer 15 to protect the first dielectric layer 15 from ion bombardment and to increase the secondary electron emission coefficient. The passivation layer 16 may be formed of a material having high visible light transmittance, high surface insulation, and excellent resistance to ion sputtering through thin film deposition technology. MgO or the like may be used as the material of the protective film 16.

The address electrode 22 is an electrode for selecting a discharge cell and is arranged in a stripe shape on the second substrate 21. At this time, the stripe address electrode 22 extends substantially perpendicular to the transparent electrodes 12a and 12b. The address electrode 22 is formed of a material having high electrical conductivity, such as gold (Au) or silver (Ag), through a printing technique.

The second dielectric layer 23 is disposed on the second substrate 21 to protect the address electrode 22 and have a high dielectric breakdown strength. The second dielectric layer 23 may be formed of a material having high light reflectance or colored with a material capable of increasing light reflectance. As the material of the second dielectric layer 23, PbO, SiO ₂ , B ₂ O _3, or the like is applicable.

The partition wall 24 prevents the discharge cell region from spreading in the length direction of the transparent electrodes 12a and 12b, prevents color mixing of visible light, increases color purity, and is installed to have a strength capable of supporting the top plate 10. The partition wall 24 is preferably narrower in width and moderately higher in height in order to form a large number of discharge spaces within the limited area. In addition, the partition wall 24 may be formed of a material having a dense structure in order to suppress inhalation of organic matter by the phosphor paste. As the material of the partition wall 24, PbO, SiO ₂ , B ₂ O _3, or the like can be used.

The phosphor layer 25 converts ultraviolet rays generated through discharge into visible light and emits them. The phosphor layer 25 is formed of a material having excellent light conversion efficiency and excellent color purity. The phosphor layer 25 includes a red phosphor layer (R), a green phosphor layer (G), and a blue phosphor layer (B).

The manufacturing method of the above-described plasma display panel of the present invention will be briefly described as follows.

First, the metal film for X-Y electrode and the black layer 14 are formed on the transparent substrate 11, and a dielectric is printed on it. The MgO thin film is deposited on the dielectric layer 15 to form a protective film 16. The upper plate 10 is prepared through the above process.

Next, a metal film for the address electrode 22 is coated on another substrate 21, and then patterned and a dielectric is printed thereon. After the dielectric is printed on the dielectric layer 23, the barrier rib 24 is formed by patterning by using a sandblasting technique. Then, the phosphor is applied in the discharge space partitioned by the partition wall 24 to form the phosphor layer 25. The lower plate 20 is prepared through the above process.

Next, a sealing material is coated on the dielectric layer of the prepared upper plate 10 or lower plate 20 and plasticized. The upper plate 10 and the lower plate 20 are aligned and fixed, and then fired at a predetermined temperature to be bonded. Then, the discharge space between the bonded upper plate 10 and the lower plate 20 is evacuated in a high vacuum state, and then the mixed gas is injected and sealed at about 500 Torr.

In the above-described method of manufacturing a plasma display panel, as shown in FIG. 2, the sealing material 30a 'positioned at the long side portion of the panel shrinks more than the sealing material (not shown) located at the short side portion of the panel, resulting in a difference in shrinkage rate. The top plate 10 and / or the bottom plate 20 may be bent, or an unwanted gap may be generated between the top plate 10 and the bottom plate 20. In particular, the unwanted gap is caused by the height difference between the sealant located at the short side and the sealant 30a 'located at the long side, which is one of the main causes of the panel noise.

However, in the manufacturing method of the plasma display panel of the present invention, in consideration of the difference in shrinkage of the sealing material generated after the sealing process described above, the sealing material applied to the long side of the panel and the sealing material applied to the short side is prepared separately according to the panel position. Differential coating allows the height of the sealing material to be kept constant despite the difference in shrinkage of the sealing material depending on the coating length. The sealing process of the upper plate and the lower plate, which is the main process of the present invention, will be described in more detail below.

3A and 3B are plan views illustrating the structure before and after the sealing step of the plasma display panel of the present invention. 4A is a partial cross-sectional view of the long side of the plasma display panel of FIG. 3B along the line II ′, and FIG. 4B is a partial cross-sectional view of the short side of the plasma display panel of FIG. 3B along the line II-II ′.

As shown in FIG. 3A, in the sealing step of the plasma display panel, the sealing material 30 is applied to the upper plate 10 or the lower plate 20, the upper plate 10 and the lower plate 20 are aligned and bonded together, and then exhausted. And gas injection.

At this time, in the present embodiment, due to the difference in the shrinkage of the sealing material applied to the long side portion and the short side portion of the panel, considering that the sealing material of the long side portion having a relatively long length shrink more than the sealing material of the short side portion having a relatively short length, When the sealant 30 is applied, a first sealant having a relatively large spacer is applied to the long side portion of the upper plate 10 or the lower plate 20, and a relatively small spacer is mixed at the cross section. 2 is made to apply the sealing material. Here, the long side means a long side in consideration of the rectangular screen area 40 of the plasma display panel, and the short side means a short side.

In the plasma display panel bonded through the firing process, the relatively long first seal 30a shrinks more than the second short seal 30b as shown in FIG. 3B. Therefore, the width w2 of the first sealing material 30a becomes wider than the width w1 of the second sealing material 30b. Nevertheless, in the present embodiment, as shown in FIGS. 4A and 4B, the volume of the first spacer 31 included in the first seal 30a includes the second spacer 32 included in the second seal 30b. (H) of the first sealing material 30a disposed on the long side portion A is substantially the same as the height h1 of the second sealing material 30b disposed on the short side portion B, since it is larger than the volume of Can be formed. As described above, according to the present invention, as shown in FIG. 2, the gap between the upper plate 10 and the lower plate 20 can be prevented from forming by the warpage of the upper plate 10 and the lower plate 20.

Although the size of the first spacer 31 and the second spacer 32 can be arbitrarily adjusted according to the characteristics of the sealing frit material and the size of the panel type, the first sealing material 30a of the long side portion A may be adjusted. In view of the experimental difference of the shrinkage of the second sealing member 30b of the short side portion B, for example, up to 10%, in this embodiment, the size of the first spacer 31 is about 10 larger than that of the second spacer 32. The content of the first spacer 31 contained in the first sealing material 30a is set to about 0.05 wt% to 2 wt%.

As described above, in the manufacture of the plasma display panel, the first sealing material 30a prepared by mixing the first spacer 31 having a relatively large size with the sealing material is disposed on the long side portion A having a relatively high shrinkage ratio, and the relative Height difference according to the shrinkage rate of the first sealant 30a by disposing the second sealant 30b prepared by mixing the second spacer 32 having a smaller size with the sealing raw material to the short side portion B having a smaller shrinkage rate. In addition, the height h1 of the first sealing material 30a of the long side portion A and the height h1 of the second sealing material 30b of the short side portion B may be substantially the same.

In other words, in the fabrication of the plasma display panel, a spacer which acts as a cushion is added to the frit paste and mixed, and the spacer is added to the long side and the short side in consideration of the shrinkage of the partition wall and / or the sealing material of the long side and the short side of the panel. By using a different particle size of the spacer, in the process of plasticizing the frit and sealing and evacuation, the top plate 10 and the top plate 10 may be separated by a difference between the shrinkage rate at which the long side portion A contracts and the shrinkage rate at which the short side portions B shrink. It is possible to prevent the gap from occurring between the lower plates 20.

On the other hand, although the case where the same size spacers are disposed in the first sealing member of the long side portion and the second sealing member of the short side portion may be considered, such a method is still long sided due to the difference in shrinkage of the long side portion and the short side portion, similar to the case shown in FIG. Since the height h2 of the negative sealing material 30a 'becomes smaller than the height h1 of the sealing material of the short side portion, the upper plate and / or the lower plate is bent, or a gap unevenly occurs between the upper plate and the lower plate. Therefore, the method using the spacer of the same size is not actually obtained noise prevention effect.

5A through 5C are cross-sectional views illustrating a plasma display panel according to another exemplary embodiment of the present invention.

In the manufacturing of the plasma display panel according to the present embodiment, as shown in FIG. 3B, the first sealing material 30a disposed on the long side portion A of the panel and the second sealing material 30b disposed on the short side portion are formed. Height nonuniformity may arise in the overlap part P. FIG.

For example, as shown in FIG. 5A, the overlapping portion P is formed at four corner portions where two long sides A and two short sides B of the panel meet when considering a rectangular panel. At this time, the overlapping portion P is formed by overlapping the first sealing material 30a and the second sealing material 30b at the corner portion, whereby the height of the overlapping portion P is different from the first sealing material 30a and the first portion. 2 It becomes higher by the predetermined height d than the height of the sealing material 30b. This height unevenness can cause panel noise.

On the other hand, in the manufacture of the plasma display panel, the process is controlled so that the height of the overlap portion P is uniform while using the first sealing material 30a and the second sealing material 30b in which spacers of different sizes are respectively mixed. If so, no further processing will be required. However, in the manufacturing process of the plasma display panel, when using the first sealing material 30a and the second sealing material 30b in which different sizes of spacers are respectively mixed, the overlapping portion P described above is reliably sealed while sealing the panel. It is difficult to make the height of) uniform. Therefore, in the present embodiment, grooves are formed in the glass substrate of the upper plate or the lower plate of the panel corresponding to the position of the overlapping portion P, and the height of the first and second sealing members including the overlapping portion P using the grooves as a whole Make it uniform.

Specifically, as shown in FIG. 5B, in the present embodiment, the groove 21a is formed in the substrate 21 'of the upper or lower panel of the panel, and the overlapping portion P described above is used by using the groove 21a. Make the height uniform. The groove 21a is preferably disposed at four corner portions of the panel, as shown in Fig. 5C. The groove 21a may be formed at a predetermined depth on one surface of the substrate 21 'by various conventional processing methods such as polishing. The shape or depth of the groove 21a may be appropriately selected in consideration of the final height or width of the sealing material and / or the size or height of the overlapping portion P.

6A is a graph illustrating a noise measurement result of a plasma display panel according to a comparative example. 6B is a graph illustrating a noise measurement result of the plasma display panel of the present invention.

In this experiment, noise was measured at atmospheric pressure, 1000 atmospheres, 1600 atmospheres, 1600 atmospheres, 2300 atmospheres, and 2800 atmospheres for the five modules for the comparative example and the five modules of the present example, respectively.

As shown in Fig. 6A, in the case of the plasma display panel of the comparative example, the module 1, the module 2, the module 3, the module 4, and the module 5 are about 24 to 26 kPa at atmospheric pressure and about 28 to 29 at 1000 atm in the order described. 소음, it produced about 32 ~ 36㏈ at 1600 atm, about 48 ~ 49㏈ at 2300 atm, and about 52 ~ 55㏈ at 2800 atm.

On the other hand, in the case of the plasma display panel of this embodiment, as shown in Fig. 6B, the module 1, the module 2, the module 3, the module 4, and the module 5 are about 22 to 23 kPa at normal pressure and about 1000 atm in the order described. It produced about 30 ~ 32㏈ at 25 ~ 26㏈, 1600atm, about 42 ~ 43㏈ at 2300 기, and about 48 ~ 51㏈ at 2800 압.

As such, the present embodiment forms grooves in the glass substrate in the region where the seal frits of the long side portion and the short side portion of the panel overlap, thereby making the height of the long side portion and the short side portion as well as their overlapping portion uniform. Therefore, it is possible to effectively prevent noise due to height unevenness between the upper plate and the lower plate during the manufacturing process of the plasma display panel.

The scope of the above-described invention is defined in the claims below, not limited to the description in the text of the specification, all modifications and variations belonging to the equivalent scope of the claims will fall within the scope of the invention.

Claims (8)

An upper plate and a lower plate disposed to face each other at predetermined intervals with the partition walls interposed therebetween; A first sealing member disposed on the long side portion between the upper plate and the lower plate and a second sealing member disposed on the short side portion to seal the discharge space partitioned by the partition wall; A first spacer inserted into the first sealing material; And A second spacer inserted into the second sealing material and smaller in size than the first spacer, And a groove provided in at least one of the upper plate and the lower plate of a portion where the first sealing material and the second sealing material overlap. The method of claim 1, And a volume of the first spacer is 10% or less than a volume of the second spacer. The method of claim 1, The sealing material is a plasma display panel consisting of a lead-free glass frit. The method of claim 1, And a width of the sealant positioned at the long side portion is greater than a width of the sealant positioned at the short side portion. The method of claim 1, An electrode group disposed between the upper plate and the lower plate and causing discharge in the discharge space; And And a phosphor layer disposed in the discharge space and emitting light by the discharge. Preparing a mixed first sealing material by adding a first spacer to the sealing material; Preparing a second sealing material in which a second space having a smaller size than the first spacer is added to the sealing material and mixed; Preparing an upper plate and a lower plate each having a long side portion and a short side portion and facing each other at predetermined intervals with partition walls therebetween; Forming a groove in a portion where the first sealing material and the second sealing material overlap at least one of the upper plate and the lower plate; Applying the first sealing material to the long side of at least one of the upper plate and the lower plate and applying the second sealing material to the short side; And And arranging and sealing the upper plate and the lower plate. The method of claim 6, The volume of the first spacer is greater than 10% than the size of the second spacer of the plasma display panel manufacturing method. The method of claim 6, The sealing raw material is a plasma display panel manufacturing method of the lead-free glass frit.