Patent Application
20080096362
Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In the drawings, elements having the same function are denoted by the same reference signs for easy understanding of the characteristics of the structure.
A plasma display panel 1 is equipped with a sealing member 35 that encloses a gas filled space 30, first and second substrates (glass substrates 11 and 21) that sandwich the gas filled space 30 and the sealing member 35, a dielectric layer (first insulator layer) 17 that is sandwiched between the first glass substrate 11 and the sealing member 35, and a dielectric layer (second insulator layer) 42 that is sandwiched between the second glass substrate 21 and the sealing member 35. The structure of the plasma display panel 1 is similar to that of the plasma display panel shown in
A dielectric layer 17 that is supported by the glass substrate 11 on the front side is an element for AC drive, and it covers first and second electrodes X and Y arranged in parallel over the entire screen. The dielectric layer 42 that is supported by the glass substrate 21 on the rear side covers third electrodes A over the entire screen so as to prevent the third electrodes A from deterioration due to discharge. Note that electrification of the dielectric layer 42 may be utilized positively for controlling address discharge and that the dielectric layer 42 may be utilized as a stopper in a sandblasting process for cutting and forming the partition 23.
The plasma display panel 1 has a characteristic that materials and thicknesses of the dielectric layer 17 and the dielectric layer 42 are selected so that etching time of the two layers until etching depth reaches the thicknesses of the layers are the same time period under the conditions that one side of each of the layers is exposed to etchant and that the same etching method is used for the layers. The etching process is not performed on the dielectric layer 17 and the dielectric layer 42 in the state shown in
The manufacturing method of the plasma display panel 1 includes a step of forming layers of predetermined elements on the glass substrates 11 and 21, a step of bonding the glass substrates 11 and 21 with the sealing member 35, and a step of evacuating inside air via an air hole that is provided to the glass substrate 21 in advance and filling a gas instead. When the bonding of the substrates is finished in the manufacturing stage, the dielectric layer 17 and the dielectric layer 42 are extended to the periphery of the sealing member 35 as shown in
There are methods of forming the substrate covering layer, which include a method of applying glass paste onto the substrate by a die coat method, a spin coat method, a spray method, a screen printing method or the like and baking the same, and a method of sticking a laminating green sheet containing glass frit to the substrate and baking the same. It is preferable for good productivity to form the substrate covering layer to cover the entire mother glass having dimensions that includes a plurality of glass substrates and then to divide the mother glass into a plurality of glass substrate.
Concrete examples of the material, the thickness and the etching method of the substrate covering layer including the dielectric layers 17 and 42 are as follows.
The same material was used for the dielectric layer 17 on the front side and the dielectric layer 42 on the rear side, and the thickness T1 of the dielectric layer 17 was set to the substantially same as the thickness T2 of the dielectric layer 42. The term “substantially” means that a difference between the thicknesses is within a range of manufacturing error like approximately a few percent, which can be regarded that the thicknesses are the same.
The material of the dielectric layer was low melting point glass made of glass frit that had the following composition and was burned at 600 degrees centigrade.
PbO: 70-75 weight percent
B2O3: 10-20 weight percent
SiO2: 10-20 weight percent
Here, design dimensions of the thicknesses T1 and T2 were 30 microns.
The sealing member 35 was made of sealing low melting point glass (e.g., ASF-2000 made by Asahi Glass Co., Ltd.). Its pattern width was approximately 10 mm, and its thickness was approximately 150 microns in the bonded state.
A work was put in a shower room into which shower of etchant was supplied, which was nitric acid solution of molar concentration 6% at temperature 25 degrees centigrade. Thus, the extending portion 17A and the extending portion 42A were etched. The extending portions 17A and 42A were removed completely at substantially the same time. The etching time was three minutes.
The thickness T1 of the dielectric layer 17 on the front side was substantially the same as the thickness T2 of the dielectric layer 42 on the rear side, while the material of the dielectric layer 17 was different from the material of the dielectric layer 42. However, the materials of the layers were selected so that the etching speeds of the layers were substantially the same. More specifically, material and thickness of the dielectric layer 17 were selected to be the same as those of the first example described above. Then, the dielectric layer 42 was made of low melting point glass having the following composition.
PbO: 60-65 weight percent
B2O3: 5-10 weight percent
SiO2: 20-30 weight percent
The etching process was performed under the same condition as the first example. Then, the extending portions 17A and 42A were removed completely at substantially the same time.
The material of the dielectric layer 42 on the rear side was selected to have smaller etching speed than the dielectric layer 17 on the front side, and the thickness T2 of the dielectric layer 42 was selected to be smaller than the thickness T1 of the dielectric layer 17.
The material of the dielectric layer 17 was the same as that in the first example, and the thickness T1 of the dielectric layer 17 was 30 microns. The dielectric layer 42 was low melting point glass having the following composition, and the thickness T2 of the dielectric layer 42 was 10 microns.
ZnO: 55-65 weight percent
B2O3: 20-30 weight percent
SiO2: 5-10 weight percent
The etching process was performed under the same condition as the first example. Then, the extending portions 17A and 42A were removed completely at substantially the same time.
A plasma display panel 2 is equipped with a sealing member 35 that encloses a gas filled space 30, first and second substrates (glass substrates 11 and 21) that sandwich the gas filled space 30 and the sealing member 35, a dielectric layer (first insulator layer) 191 that is sandwiched between the first glass substrate 11 and the sealing member 35, and a dielectric layer (second insulator layer) 22 that is sandwiched between the second glass substrate 21 and the sealing member 35.
The plasma display panel 2 has a characteristic that the dielectric layer 19 covering the electrodes X and Y on the front side has a double layer structure including the first dielectric layer (under layer) 191 and a second dielectric layer (over layer) 192. In addition, materials and thicknesses of the under layer 191 and the dielectric layer 22 on the rear side are selected so that etching time of the two layers until etching depth reaches the thicknesses of the layers are the same time period under the conditions that one side of each of the layers in the thickness direction is exposed to etchant and that the same etching method is used for the layers. The etching process is not performed on the under layer 191 and the dielectric layer 22 in the state shown in
The over layer 192 is an element for setting the thickness of the dielectric layer 19 to be large enough for adapting to the AC drive. The over layer 192 is disposed so as to extend over the entire screen and not to protrude from the outer rim of the sealing member 35. Although the over layer 192 contacts the sealing member 35 in
When the bonding of the substrates is finished in the manufacturing stage of the plasma display panel 2, the under layer 191 and the dielectric layer 22 are extended to the periphery of the sealing member 35 as shown in
There are methods of equalizing the etching time of the extending portions 191A and 22A, which are similar to the methods of the first to the third examples described above. In other words, it is sufficient to equalize materials and thicknesses T3 and T2 of the substrate covering layers on the front side and on the rear side, or to select materials having equal etching speed and equalize the thicknesses T3 and T2, or to make the thickness T3 and the thickness T2 different from each other in accordance with a difference of their etching speeds.
As to the embodiments described above, there is no special limitation of materials of the electrodes, the arrangement form of the same, the cell structure of the screen, and the like. The materials and the thicknesses T1, T2 and T3 of the dielectric layers 17, 19, 22 and 42, the material and the dimensions of the sealing member 35, the etchant, the type of the etching device, and the like are not limited to those exemplified above but can be modified within the scope in accordance with the spirit of the present invention, if necessary.
The present invention can be applied to various display devices that perform color displays with gas discharge, which include a display device of a data processing device such as a personal computer or a workstation, a flat type television set, a display device for a public display such as advertisement or guide information, and the like.
While example embodiments of the present invention have been shown and described, it will be understood that the present invention is not limited thereto, and that various changes and modifications may be made by those skilled in the art without departing from the scope of the invention as set forth in the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-287998 | Oct 2006 | JP | national |
