Background Art A most general discharge display panel is a plasma display panel. As an example of the discharge display panel, the plasma display panel will be hereinafter explained.

The plasma display panel is a flat display device in which sustain electrodes and address electrodes are fabricated in the form of a matrix between upper and lower plates to drive pixels and images can be implemented by using ultraviolet rays generated due to discharge between the electrodes.

Recently, as a new product, the plasma display panel has been spotlighted. in the display markets. The reason is that the plasma display panel is suitable for a large screen and it can be employed in a wall-mounted display device because of its small thickness.

In particular, among display devices with a memory function, the plasma display panel is the only self-emissive display device capable of displaying moving pictures with the large screen.

The constitution of the conventional discharge display panel will be hereinafter explained.

FIG. 1 shows upper and lower plate structures of the conventional plasma display panel. As shown in the figure, the upper plate structure of the plasma display panel is manufactured in such a manner that a pair of sustain electrodes 45 with a predetermined width and height are formed on a coplanar surface of an upper substrate 50, a dielectric layer 40 is then formed for protecting the sustain electrodes 45 and for preserving charges excited upon discharge so that the discharge can be made again even at a low voltage upon

sustain discharge, and a protective layer 35 for protecting the electrodes and the like from being damaged due to strong discharge and for discharging secondary electrons is finally formed on the dielectric layer 40.

As also shown in the figure, the lower plate structure of the conventional plasma display panel is manufactured in such a manner that respective unit cells are selectively addressed onto a lower substrate 10 and address electrodes 15 for inducing initial discharge are then formed thereon. Further, an insulating dielectric layer 20 is formed on the address electrodes 15, discharge spaces are formed on the dielectric layer 20, separators 30 for preventing crosstalk phenomena between the adjacent cells are formed, and phosphor layers 25 made of R, G, B phosphors for generating visible rays by using ultraviolet rays generated from the discharge are formed on the dielectric layer 20 and sidewalls of the separators 30.

Furthermore, the discharge spaces 55 are formed between the upper and lower substrates. Discharge gas such as Ne, Xe, He gas is injected into the discharge spaces 55.

Then, an upper surface of the lower plate structure comes into close contact with a lower surface of the upper plate structure, and thus, a complete unit cell of the plasma display panel is fabricated.

According to the plasma display panel manufactured as such, surface discharge is generated and images are displayed thereon, as follows.

If an initial discharge voltage is applied to the sustain electrodes 45 and the address electrodes 15 so that a potential difference can be produced therebetween, the initial discharge is produced in the discharge space 55. Then, the ultraviolet rays are generated while the surface discharge is produced between the pair of sustain electrodes 45.

At this time, due to the generated ultraviolet rays, the phosphors of the adjacent phosphor layer 25 are excited and full color display is then made.

That is, electrons remaining within discharge cells are accelerated by means of the applied voltage, and they collide with mixed inert gas injected into the discharge cells at a pressure of about 400-600 Torr and the ultraviolet rays are then generated. Thus, the visible rays are generated due to the collision of the generated ultraviolet rays with the phosphor layer 25. By combining the cells in which the discharge is produced in the

above manner with the cells in which the discharge is not produced, desired images can be displayed.

However, the conventional plasma display panel manufactured as such has the following problems.

The lower plate structure of the conventional plasma display panel is manufactured in such a manner that the address electrodes 15 for selectively addressing the cells are first formed longitudinally on the lower substrate 10 made of glass in the form of a stripe, and entire surfaces of the electrodes are covered with the dielectric layer 20 for protecting and insulating the address electrodes 15. Further, the separators 30 for defining the discharge space 55 of the respective cells for use in the discharge are formed on the dielectric layer 20.

Therefore, according to the lower plate structure of the conventional plasma display panel, the address electrodes 15 and the dielectric layer 20 should be beforehand formed on the lower substrate 10 prior to manufacture of the separators 30. In addition, in order to manufacture the separators 30, the processes of printing, drying, exposure, developing, sand blast, peeling, and baking should be sequentially performed. In the baking process, the processing temperature should be maintained to be greater than about 550°C.

Furthermore, the lower substrate 30 on which the separators 30 are formed is generally made of a transparent glass material, which is in turn most likely to be deformed at the processing temperature from above about 510°C. However, since the baking process for the separators should be performed above the temperature at which the deformation of the glass occurs, the distortion of the lower substrate 10 made of the glass cannot be prevented during the high temperature baking process of forming the separators 30.

Due to the distortion of the substrate, there is a problem in that positions of the address electrodes already formed on the substrate prior to the manufacture of the separators may be changed from an already designed pattern.

In the plasma display panel, alignment of the address electrodes formed on the lower substrate with the separators and central portions of the separators should be made as

precisely as possible for the uniform discharge between the cells. However, there are some problems in view of the alignment of the address electrodes due to the aforementioned change in the positions of the address electrodes. Thus, a yield of the above process is reduced and manufacturing costs are increased.

In addition, there is a further problem in that all functional elements such as separators, address electrodes and dielectric layer are not matched or aligned with the already designed pattern because the substrate is distorted due to the high temperature baking process. Due to the above, it is very difficult to adjust the alignment of the phosphor layer which should be aligned with the address electrodes and then formed on upper ends of the separators.

In particular, in the plasma display panel with very high resolution, the spaces defined between the separators should be very precisely patterned. If the electrodes are not formed in accordance with the pattern, the uniform discharge spaces between the respective cells cannot be obtained. Thus, there is a still further problem in that the desired resolution of the plasma display panel cannot be achieved.

Moreover, the address electrodes 15 and the dielectric layer 20 can be generally formed on the lower substrate 10 at a temperature below about 500°C. However, since the baking process of forming the separators 30 should be kept at a temperature above about 550 °C, an excessively high temperature (above about 550 °C) should be maintained during a process of bonding the address electrodes 15 and the dielectric layer 20 which are formed on the lower substrate 10 prior to the manufacture of the separators 30.

An object of the present invention is to provide a lower plate structure of a discharge display panel and a method of manufacturing the same wherein change in positions of elements (layers) constituting respective cells due to distortion of glass can be prevented and a need for an excessively high temperature process can be avoided.

Another object of the present invention is to provide a structure of a discharge display panel wherein change in positions of elements (layers) constituting respective cells due to distortion of glass can be prevented and a need for an excessively high temperature process can be avoided.

Disclosure of Invention According to an aspect of the present invention for achieving the above objects, there is provided a lower plate structure of a discharge display panel of the present invention, which comprises a substrate, a plurality of separators formed directly on a top surface of the substrate for defining discharge spaces, address electrodes formed on surfaces of the respective discharge spaces defined between the adjacent separators, and phosphor layers formed on the respective address electrodes.

Preferably, the lower plate structure of the present invention further comprises dielectric layers formed on the respective address electrodes.

More preferably, the separators are formed integrally with the substrate.

According to another aspect of the present invention, there is provided a structure of a discharge display panel, which comprises a lower plate including a substrate, a plurality of separators formed directly on a top surface of the substrate, address electrodes formed on surfaces of respective discharge spaces defined between the adjacent separators, and phosphor layers formed on the respective address electrodes ; and an upper plate which includes a pair of sustain electrodes for inducing surface discharge from a bottom surface thereof and is bonded to a top surface of the lower plate.

According to a further aspect of the present invention, there is provided a structure of a discharge display panel according to the present invention, which comprises a lower plate including a substrate, a plurality of separators formed directly on a top surface of the substrate, address electrodes formed on surfaces of respective discharge spaces defined between the adjacent separators, and phosphor layers formed on the respective address electrodes; and an upper plate which includes discharge electrodes for inducing counter discharge from a bottom surface thereof and is bonded to a top surface of the lower plate.

In addition, according to a still further aspect of the present invention, there is provided a method for manufacturing a lower plate structure of a discharge display panel, comprising the steps of forming a plurality of separators on a substrate, forming address electrodes between the respective adjacent separators, forming dielectric layers on the respective address electrodes, and forming phosphor layers on the respective dielectric layers.

Preferably, the respective address electrodes are formed out of Au/Al and the dielectric layers made of A1203 are formed thereon by means of an anodization technique.

Brief Description of Drawings FIG. 1 is a view showing a structure of a general discharge display panel.

FIGS. 2a and 2b are views showing a structure of a discharge display panel according to a first preferred embodiment of the present invention.

FIG. 3 is a view showing a structure of a discharge display panel according to a second preferred embodiment of the present invention.

FIG. 4 is a flowchart illustrating processes of manufacturing a lower plate structure of the discharge display panel according to the present invention.

Best Mode for Carrying out the Invention Hereinafter, a discharge display panel of the present invention will be described with reference to the accompanying drawings.

FIGS. 2a and 2b show a structure of discharge display panel according to a first preferred embodiment of the present invention. In particular, FIG. 2a shows lower and upper plate structures as a whole, and FIG. 2b shows only the lower plate structure.

The discharge display panel according to the first embodiment of the present invention includes a pair of sustain electrodes 135 formed on an upper substrate 140 and performs surface discharge.

The upper plate structure of the discharge display panel of the present invention is configured in such a manner that the pair of sustain electrodes 135 with a predetermined width and height, a dielectric layer 130 for insulating the sustain electrodes 135, and a protective layer 125 for protecting the dielectric layer 130 so as to prolong the life of the panel are sequentially formed on a coplanar surface of the upper substrate 140.

The sustain electrodes 135 are formed so as to sustain continuous discharge after initial discharge. The dielectric layer 130 is formed so as to preserve charges, which are excited upon the discharge, so that the discharge can be again made even at a lower voltage upon the sustain discharge. The protective layer 125 is formed so as to prevent the

electrodes from being damaged due to the strong discharge and to ensure emission of secondary electrons.

Further, the lower plate structure of the plasma display panel according to the first embodiment of the present invention is configured in such a manner that separators 105 for defining uniform discharge spaces and preventing crosstalk between adjacent cells are first formed by etching a lower substrate 100 made of a transparent glass material. That is, the separators 105 can be formed integrally with the lower substrate by directly etching the lower substrate 100, contrary to the conventional separators.

Each of address electrodes 110 is applied to have a predetermined thickness onto whole surfaces of inner sidewalls of the two adjacent separators and a portion of a top surface of the lower substrate. A dielectric layer 115 for entirely covering and insulating the address electrode 110 is formed on the address electrode 110.

A phosphor layer 120 is formed on the dielectric layer 115. The dielectric layer 115 is almost covered with the phosphor layer 120 except an upper portion 115a of inner sidewalls of the dielectric layer 115. Thus, the discharge is induced between the sustain electrodes 135 formed on the upper substrate and the electrode portions 115a not covered with the phosphor layers 120 at the upper portions of the relevant separators 105.

The address electrodes 110 are formed so as to selectively address the respective cells and to induce the initial discharge. The phosphor layer 120 is made of R, G, B phosphors for emitting light by means of ultraviolet rays generated through the discharge and generating visible rays.

In particular, in a case where the address electrode 110, the dielectric layer 115, and the phosphor layer 120 are formed between the two adjacent separators 105 in order to manufacture the lower plate structure according to the first preferred embodiment of the present invention, they are applied onto a top surface of the lower substrate 100 up to about 80% of a height of the separator 105 and thus the remaining space is assigned as the discharge space. Therefore, as shown in FIG. 2b, the address electrode 110 and the dielectric layer 115 formed between the two adjacent separators 105 in the lower plate structure of the present invention are preferably formed to take a concave shape.

Hereinafter, a method for manufacturing the plasma display panel according to the

first embodiment of the present invention constructed as such will be explained.

FIG. 4 is a flowchart illustrating processes of manufacturing the lower plate structure of the discharge display panel according to the present invention.

The transparent glass material is first machined and cleaned so as to manufacture the lower substrate 100 with a desired size (step 500). The separators 105 are formed by etching the lower substrate 100 manufactured in step 500 (step 510). The separators 105 may be formed by forming the materials for the separators onto the top surface of the lower substrate 100 and then etching the materials for the separators to have the desired size.

Alternatively, the separators may be formed integrally with the lower substrate 100 through the direct etching of the substrate.

If the separators 105 are formed on the lower substrate 100 in step 510, cell units are formed in the plasma display panel. If the separators 105 are completely formed in step 510, each of the address electrodes is formed on the whole surfaces of the inner sidewalls of the two adjacent separators 105 and the top surface of the lower substrate between the separators (step 515).

That is, according to the present invention, the separators 105 are first formed on the lower substrate 100 and the address electrodes 110 are then formed thereon. Thus, since an effect of a baking temperature of the separators is eliminated when the address electrodes 110 are formed using a photosensitive paste method or pattern printing method, the baking process can be performed at a temperature below about 500°C.

Further, since the address electrodes 110 are formed after the separators 105 have been formed, the distortion of the substrates are not produced during the processes to be performed after the electrode formation. Thus, when the upper and lower plate structures are bonded with each other, there is no problem upon alignment thereof. Further, since the separators are first formed and the electrodes are then formed between them, the process of forming the electrodes can be easily performed.

Thereafter, the dielectric layer for entirely covering each of the address electrodes is formed on the address electrode 110 (step 520). At this time, if the address electrode 110 is formed out of Au/Al and then transformed into A1203 through an anodization technique, it may be used as the dielectric layer. Contrary to the conventional process, the

baking process of forming the dielectric layer 115 can also be performed at a temperature of about 400 °C. The reason is that the dielectric layer baking process cannot be affected by the temperature at the time when the separators are formed since the process of forming the dielectric layer 115 is performed after the separators have been formed.

In addition, as a final step of manufacturing the lower plate structure of the plasma display panel, the phosphor layer 120 is formed on the dielectric layer 115 (step 525). At this time, in order to maximize brightness and luminance efficiency, the phosphor layer is applied onto the inner surfaces of the sidewalls of the separators to have a uniform thickness. The phosphor layer is formed using a screen printing method, a photosensitive paste method, a dry film method, and the like.

As shown in FIG. 2b, the phosphor layers 120 are preferably applied in a state where some upper ends of the separators are not covered with the phosphor layers so that the uncovered electrode portions 115a can be formed at the upper ends of the separators.

The reason is that the discharge can be induced from between the electrodes of the upper substrate and the electrode portions not covered with the phosphor layers 120.

Now, a process of manufacturing the upper plate structure of plasma display panel for performing the surface discharge will be explained.

The upper plate structure of the plasma display panel is manufactured in such a manner that the pair of sustain electrodes 135 with the predetermined width and height are formed on the coplanar surface of the upper substrate 140, the dielectric layer 130 for protecting the sustain electrodes 135 and functioning as an electrical condenser is then printed thereon, and the protective layer 125 for protecting the sustain electrodes 135 and the dielectric layer 130 from being damaged and ensuring the prolonged life of the display panel is finally formed on the dielectric layer 40.

At this time, if the sustain electrodes 135 are formed out of Au/Al/Mg or Au/Mg and then transformed into Au/A1203/MgO or Au/MgO through the anodization technique, both the dielectric layer and the protective layer may be simultaneously formed.

If an initial discharge voltage is applied to the sustain electrodes 135 and the address electrodes 110 of the plasma display panel constructed as such so that a potential difference can be produced therebetween, the initial discharge is first produced, and then,

the ultraviolet rays are generated while the surface discharge is produced between the pair of sustain electrodes 135. At this time, due to the generated ultraviolet rays, the R, G, B phosphors of the adjacent phosphor layer 120 are excited and thus the light is emitted from the phosphors so that full color display can be made. Then, these colors are combined and desired images are thus displayed.

FIG. 3 shows a structure of a plasma display panel according to a second preferred embodiment of the present invention.

The plasma display panel according to the second embodiment of the present invention has a counter-discharge structure.

The lower plate structure of the plasma display panel according to the second embodiment of the present invention is identical with that of the first embodiment of the present invention, except that the upper plate structure thereof includes an ITO electrode and a metal electrode for performing the counter-discharge instead of the two sustain electrodes.

In the counter-discharge type structure, a highly conductive bus electrode may be further formed on the ITO electrode so as to enhance conductivity of the ITO electrode.

Industrial Applicability As described above, the discharge display panel of the present invention is manufactured in such a manner that the separators are first formed on the lower substrate, and the address electrodes and the dielectric layers are sequentially formed to define the discharge spaces between the adjacent separators. According to the present invention, therefore, the baking temperature for the manufacture of the address electrodes and the dielectric layers can be lowered since it is not affected by the baking temperature for the manufacture of the separators, contrary to the prior art. Accordingly, there are advantages in that the problem related to the alignment is solved since the distortion of the lower substrate due to the high temperature baking process can be prevented, and that the display panel can be easily manufactured since the temperature during the process of baking the address electrodes and the dielectric layers can be lowered.