1. Field of the Invention
The present invention relates to a flat panel display apparatus, and in particular to a backplate of a PDP(Plasma Display Panel) has a high definition, a high aspect ratio, and a high luminance.
2. Description of the Background Art
Recently, a flat panel display apparatus such as a LCD(Liquid, Crystal Display), a FED(Field Emission Display) and a PDP(Plasma Display Panel) has been intensively studied. Among the above-described apparatuses, the PDP is easily fabricated because of its simple structure and has a high luminance and light emitting efficiency, a good memory function, and a wide view angle wider than 160xc2x0, so that the PDP is well applicable to a wide screen of more than 40 inches.
The construction of a surface discharge AC PDP of the conventional art will be explained with reference to FIG. 1.
A front glass plate 10 and a back glass plate 20 are facing and distanced from each other, and a discharge region 30 which is defined by a corresponding barrier rib 23 is formed between the front glass plate 10 and the back glass plate 20.
A plurality of address electrodes A are extended in a certain direction on the upper surface of the back glass plate 20. A dielectric layer 22 is formed on the upper surfaces of the back glass plate 20 and the address electrodes A.
A plurality of barrier ribs 23 are formed on the upper surface of the dielectric layer between the address electrodes A. In addition, a fluorescent layer 24 is coated on both walls of each barrier rib 23 and on the upper surface of the dielectric layer 22 which covers the address electrodes A.
A sustain and display electrode Xn and a scan electrode Yn are spaced-apart in a parallel direction perpendicular to the direction of the address electrodes A on one surface of the front glass plate. The sustain and display electrode Xn is formed of a transparent ITO(lndium Tin Oxide), so that light passes through the same. Therefore, the sustain and display electrode is called as a transparent electrode. Bus electrodes 13 are formed at the end portions of the sustain and display electrode Xn and the scan electrode Yn for applying a stable driving voltage. The bus electrode 13 is formed of an aluminum or chrome/copper/chrome layers. In addition, a dielectric layer 14 which is formed of a PbO group material covers the sustain and display electrode Xn, the scan electrode Yn, the bus electrode 13 and the front glass plate 10. MgO is coated on the surface of the dielectric layer 14 as a protection film 15. The MgO protection film protects the PbO dielectric layer from a sputtering of ions and has a relatively higher secondary electron generating coefficient characteristic when an ion energy collides with the surfaces during a PDP plasma discharge and decreases a driving and sustaining voltage of the discharge plasma.
As shown in FIG. 1, He, Ne, Ar or a mixed gas of the same and a mixed gas of Xe 31 are filled in a discharge cell surrounded by the barrier rib of the PDP. The region between the barrier ribs becomes a discharge region 30, namely, a discharge cell 30 for generating a discharge therein.
In the PDP, a plasma discharge is generated in the discharge region 30 by applying a certain voltage to the transparent electrodes. As an infrared ray generated by the plasma discharge excites the fluorescent layer formed on the backplate for thereby generating a visual ray. The thusly generated visual ray is made incident onto the front plate for thereby displaying a certain character or graphic. Therefore, the front plate is used as a plate for displaying graphics, and the backplate is used for generating visual light.
As described above, the PDP apparatus includes a plurality of discharge cells which are physically separated from each other by the barrier ribs. In order to fabricate a PDP apparatus having a lot amount of pixels using the same area panel, a plurality of discharge cells are required. However, when decreasing the size of the discharge region in order to increase the number of discharge cells, the discharge efficiency is decreased. Therefore, in a state that a certain size of the discharge region is maintained, in order to manufacture a large number of discharge cells, a higher and thicker barrier rib is required. A method for satisfying the above-described requirements has been intensively studied. The conventional barrier rib fabrication method will be explained with reference to FIGS. 2 through 4.
First, a fabrication method of a barrier rib based on a screen print method will be explained with reference to FIGS. 2A through 2C.
As shown in FIG. 2A, a dielectric film 201 is formed on an upper surface of a glass plate 200. Next, a screen(not shown) having a pattern for fabricating a barrier rib is prepared on an upper surface of the glass plate 200. An insulation paste is coated on the screen using a roller, etc. and is dried for thereby forming a first insulation paste pattern 202 as shown in FIG. 2a. Thereafter, the screen is prepared thereon again, and an insulation paste is coated and then dried. The above-described operation is repeatedly performed, so that a second insulation paste pattern 203 is stacked on the first insulation paste pattern 202 as shown in FIG. 2b. 
Next, the screen print method is repeatedly performed until the entire height of the stacked insulation paste pattern becomes 150xcx9c200 xcexcm for thereby forming a barrier rib 204 as shown in FIG. 2C.
The above-described barrier rib fabrication method based on the screen print method is simple, and the cost of the same is low. However, it is needed to adjust the position of the plate and the screen at every time when performing the screen print process. In addition, a certain small misalignment may occur when adjusting the positions of the screen and plate in the repeated screen print processes, it is difficult to fabricate an accurate barrier rib and high definition barrier rib. In addition, since the above-described print and dry processes are repeatedly performed, a fabrication time is too extended.
As another conventional barrier rib fabricating method, there is a sand blasting method. The above-described sand blasting method will be explained with reference to FIGS. 3A through 3E.
Next, as shown in FIG. 3A, an insulation paste 301 is formed on a glass plate 200 by a thickness of 150xcx9c200 xcexcm.
Next, as shown in FIG. 3B, a photosensitive film 302 is formed on the insulation paste 301. The photosensitive film 302 is formed in a tape shape by adding an organic material to a photosensitive slurry at a certain ratio and is stack-formed on the insulation paste.
The photosensitive film 302 is patterned by a photolithography method for thereby forming a photosensitive film pattern 302a as shown in FIG. 3C.
As shown in FIG. 3D, the insulation paste 301 is etched by spraying an alumina or silica particle(polishing material) using the photosensitive film pattern 302a as a mask.
Thereafter, the photosensitive film pattern 302a is removed for thereby forming a barrier rib 301a as shown in FIG. 3E.
In the barrier rib fabrication method based on the sand blasting method, it is possible to form a barrier rib on a large area plate and to implement a high definition. However, since a lot amount of pastes which are removed by a polishing material is required, and the fabrication cost is high. In addition, since a physical impact is applied to the plate during the fabrication process, a crack may occur at the plate during the molding operation of the insulation paste.
As another conventional barrier rib manufacturing method, an additive method will be explained with reference to FIGS. 4A through 4E.
As shown in FIG. 4a, a photosensitive film 401 is formed on a glass plate 400. The above-described photosensitive film may be formed in a dry film shape and is attached on the glass plate. The photosensitive film may be formed is such as manner that a photosensitive resin is coated using a spin cotter.
Next, the photosensitive film 401 is patterned based on a photolithograph method using a light exposing mask for thereby forming a photosensitive film pattern 402 as shown in FIG. 4B.
As shown in FIG. 4C, an insulation paste 403 is filled between the photosensitive film patterns 402.
As shown in FIG. 4d, the photosensitive film pattern 402 is removed, so that only the insulation paste 403 remains on the glass plate.
The above-described processes of FIGS. 4A through 4D are repeatedly performed, so that a barrier 404 having a height of 150xcx9c200 xcexcm is formed as shown in FIG. 4E.
In the additive method for fabricating a barrier rid, it is possible to fabricate a barrier rib having a fine width and a large size area plate. However, in this method, if the height of the barrier rib exceeds 10xe2x96xa1m, it takes long time to coat the pattern. In addition, since the insulation paste and photosensitive film are repeatedly patterned and removed for fabricating the barrier rib, a certain residual material of the insulation paste and photosensitive film may remain. In addition, the pattern may be deformed, and a crack may occur at the barrier rib.
Another conventional barrier rib fabrication method will be explained with reference to FIGS. 5A through 5D.
As shown in FIG. 5A, a barrier rib material layer 501 is formed on an upper surface of a glass plate 500 to have a thickness(for example, 150xcx9c200 xcexcm). The barrier rib material layer is formed by coating an insulation paste or attaching a green tape.
As shown in FIG. 5B, a mold 503 having a groove 502 is prepared at a portion in which a barrier rib is formed on the barrier rib material layer 501.
Next, a certain pressure is applied and stamped, and then as shown in FIG. 5C, a barrier rib material is filled into the groove 502.
Thereafter, the mold 503 is removed for thereby forming a barrier rib 505 as shown in FIG. 5D.
However, in the above-described stamping method, in order to fill a barrier rib material into the mold, a certain pressure is required. In addition, a uniform pressure must be applied to the mold. If the pressure is not uniform, the barrier rib may not have the same height. In addition, as the barrier rib is highly defined, it is impossible to separate the mold and the barrier rib material layer after the barrier rib material is filled in the mold.
Accordingly, it is an object of the present invention to provide a backplate for a PDP(Plasma Display Panel) which is capable of providing a backplate of a PDP using an easily etched metallic material.
It is another object of the present invention to provide a structure of a PDP backplate which has an excellent heat transfer characteristic and heat radiating characteristic.
To achieve the above object, there is provided a backplate for a PDP according to a first embodiment of the present invention which includes a metallic plate having a certain thickness, a plurality of barrier ribs formed by etching the metallic plate, and an insulation formed on the wall surfaces of the barrier ribs and on an upper surface of the metallic plate.
To achieve the above object, there is provided a backplate for a PDP according to a second embodiment of the present invention which includes a metallic plate having a certain thickness, a plurality of barrier ribs arranged at a certain distance from each other on the metallic plate, an insulation layer formed on the wall surfaces of the barrier ribs and an upper surface of the metallic plate, a conductive layer formed on an upper surface of the insulation layer, a dielectric layer formed on a surface of the conductive layer, and a florescent layer formed on an upper surface of the dielectric layer.
Additional advantages, objects and features of the invention will become more apparent from the description which follows.