Method of producing plasma display panel with protective layer of an alkaline earth oxide

Abstract

The first object of the present invention is to provide a PDP with improved panel brightness which is achieved by improving the efficiency in conversion from discharge energy to visible rays. The second object of the present invention is to provide a PDP with improved panel life which is achieved by improving the protecting layer protecting the dielectrics glass layer. To achieve the first object, the present invention sets the amount of xenon in the discharge gas to the range of 10% by volume to less than 100% by volume, and sets the charging pressure for the discharge gas to the range of 500 to 760 Torr which is higher than conventional charging pressures. With such construction, the panel brightness increases. Also, to achieve the second object, the present invention has, on the surface of the dielectric glass layer, a protecting layer consisting of an alkaline earth oxide with (100)-face or (110)-face orientation. The protecting layer, which may be formed by using thermal Chemical Vapor Deposition (CVD) method, plasma enhanced CVD method, or a vapor deposition method with irradiation of ion or electron beam, will have a high sputtering resistance and effectively protect the dielectrics glass layer. Such a protecting layer contributes to the improvement of the panel life.

1. A method of producing a PDP, the method comprising:
 a first step of forming a front cover plate by forming a first electrode and a dielectric glass layer on a front glass substrate then forming a protecting layer of an alkaline earth oxide with one of (100)-face orientation and (110)-face orientation on the dielectric glass layer; and    a second step of forming a back plate by forming a second electrode and a fluorescent substance layer on a back glass substrate then bonding the front cover plate, on which the protecting layer has been formed, with the back plate, and charging a gas medium into a plurality of discharge spaces which are formed between the front cover plate and the back plate, the front cover plate and the back plate facing to each other.    
     
     
       2. The method of producing a PDP of  claim 1 , wherein
 in the first step, the protecting layer is formed with one of a thermal Chemical Vapor Deposition method and a plasma Chemical Vapor Deposition method by using an alkaline earth organometallic compound and oxygen.    
     
     
       3. The method of producing a PDP of  claim 2 , wherein
 the alkaline earth organometallic compound used in the first step is one of an alkaline earth metal chelate compound and an alkaline earth cyclopentadienyl compound.    
     
     
       4. The method of producing a PDP of  claim 3 , wherein
 the alkaline earth organometallic compound used in the first step is one of M(C 11 H 19 O 2 ) 2 , M(C 5 H 7 O 2 ) 2 , M(C 5 H 5 F 3 O 2 ) 2 , and M(C 5 H 5 ) 2 , wherein M represents one of magnesium, beryllium, calcium, strontium, and barium.    
     
     
       5. A method of producing a plasma display panel having a plurality of discharge space cells with a front substrate and a rear substrate and walls separating each cell, each discharge space is addressable by display electrodes to cause the cell to emit light comprising:
 depositing a protective layer of an alkaline earth oxide having one of a (100) crystal face orientation and a (110) crystal face orientation extending across a top surface of each cell; and    charging each cell with a discharge gas.    
     
     
       6. The plasma display panel method of  claim 5  wherein each cell is pressurized to pressure of approximately 500 to 760 Torrs. 
     
     
       7. The plasma display panel method of  claim 6  wherein each cell is charged with an xenon discharge gas between 10% by volume to approximately 100% by volume. 
     
     
       8. The plasma display panel method of  claim 7  wherein one of argon, kryptor, helium and neon is mixed with the xenon. 
     
     
       9. The plasma display panel method of  claim 7  wherein one of argon and krypton is mixed with the xenon in sufficient volume to provide ultraviolet light emission at a wavelength of 173 nm. 
     
     
       10. The plasma display panel method of  claim 7  wherein two additional discharge gases within the range of 10% to 50% by volume are mixed with the xenon. 
     
     
       11. The plasma display panel method of  claim 6  wherein a distance between adjacent display electrodes in the same plane is no greater than 0.1 mm. 
     
     
       12. The plasma display panel method of  claim 5  wherein the protective layer is selected from a group consisting of MgO, BeO, CaO, SrO and BaO. 
     
     
       13. The plasma display panel method of  claim 5  wherein the protective layer is magnesium oxide with a crystal face orientation of(110). 
     
     
       14. The plasma display panel method of  claim 5 , wherein the first substrate includes a dielectric glass layer and the dielectric glass layer is heated to a temperature between 350° C. to 400° C. during the depositing of the protective layer by a thermal chemical vapor deposition. 
     
     
       15. The plasma display panel method of  claim 5 , wherein the front substrate includes a dielectric glass layer and the dielectric glass layer is heated to a temperature between 250° C. to 300° C. during the depositing of the protective layer by a plasma enhanced chemical vapor deposition. 
     
     
       16. The plasma display panel method of  claim 5 , wherein the front substrate includes an upper glass plate and a lower dielectric glass layer, and display electrodes are formed from depositing a conductive paste on the upper glass plate, the paste is then baked to harden it and subsequently is sandwiched with the lower dielectric glass layer. 
     
     
       17. The plasma display panel method of  claim 5 , wherein the protective layer is deposited by transferring a paste of the alkaline earth oxide to the front substrate and baking it. 
     
     
       18. The plasma display panel method of  claim 17 , wherein the paste is a magnesium salt with a plate-shaped crystal structure. 
     
     
       19. The plasma display panel method of  claim 18 , wherein the paste is magnesium oxalate formed by dissolving ammonium oxalate in a magnesium chloride aqueous solution and heating it to form the plate-shaped crystal structure. 
     
     
       20. The plasma display panel method of  claim 5 , wherein the depositing of the protective layer is made by evaporating the alkaline earth oxide with an ion/electron beam in a vacuum. 
     
     
       21. A method of producing a plasma display panel having a plurality of discharge space cells, each discharge space cell is addressable by display electrodes to cause the cells to emit light, comprising:
 depositing a protective layer of an alkaline earth compound selected from the group consisting of M(C 11 H 19 O 2 ) 2 , M(C 5 H 7 O 2 ) 2 , M(C 5 H 5 F 3 O 2 ) 2 , and M(C 5 H 5 ) 2 , wherein M represents one of magnesium, beryllium, calcium, strontium, and barium, the protective layer having one of a (100) crystal-face orientation and a (110) crystal-face orientation extending across a surface of each cell; and    charging each cell with a discharge gas.    
     
     
       22. The plasma display method of  claim 21 , wherein the protective layer is deposited by one of a thermal chemical vapor deposition step and a plasma enhanced chemical vapor deposition step. 
     
     
       23. The plasma display method of  claim 22 , wherein the discharge gas includes at least 10% by volume Xe and is at a pressure of at least 500 Torr. 
     
     
       24. The plasma display method of  claim 23 , wherein the discharge gas includes one of Ar and Kr. 
     
     
       25. The plasma display method of  claim 23  wherein the discharge gas is selected from a group consisting of Ar-He-Xe, Ar-He-Xe, Kr-Ne-Xe, and Kr-He-Xe and the amount of Kr, Ar, He, or Ne should be in the range of 10% to 50% by volume. 
     
     
       26. The plasma display method of  claim 23 , wherein the alkaline earth compound is selected from the croup consisting of magnesium dipivaloyl methane, magnesium acetylacetone, magnesium trifluoroacetylacetone, and cyclopentadienyl. 
     
     
       27. A method of producing a plasma display panel having a plurality of discharge space cells, each discharge space cell is addressable by display electrodes to cause the cell to emit light, comprising:
 depositing a protective layer selected from the group consisting of magnesium dipivaloyl methane, magnesium acetylacetone, magnesium trifluoroacetylacetone, and cyclopentadienyl magnesium across a surface of each cell to provide one of a (100) crystal-face orientation and a (110) crystal-face orientation; and    charging each cell with a discharge gas including at least 10% by volume Xe at a pressure of at least 500 Torr.    
     
     
       28. A system for forming a protective layer on a plasma display panel comprising:
   a vacuum chamber housing,        means for supporting a plasma display panel substrate with electrodes in the housing;        means for heating the plasma display panel substrate;        means for evaporating, from a source of magnesium oxide, a predetermined amount of magnesium oxide to provide the protective layer on the plasma display panel substrate; and        an electron gun aligned with the means for supporting for evaporating magnesium oxide, as applied to the plasma display panel substrate, to provide a single layer of a  (   110   )- face orientation of sufficient thickness to provide sputtering resistance during a predetermined life term of the plasma display panel.     
     
     
       29. The system of  claim 28  wherein the plasma display panel substrate is heated to a temperature of  150 ° C. and the magnesium oxide is applied to a thickness of  5000  A ° for the protective layer.