Protective film for plasma display panel and method for manufacturing this protective film, and plasma display panel and method for manufacturing thereof

Abstract

A plasma display panel 1 of the present invention has a protective film 14 over a sustaining electrode 15 and a scanning electrode 16 , with the main components of the protective film being CaO and SrO, and the concentration of the CaO in the protective film 14 is 20 mol % or more and 90 mol % or less. This protective film 14 has a smaller work function than a conventional MgO film so light can be emitted at a lower discharge voltage than in the past. If the discharge voltage is lower, the protective film 14 will be sputtered more slowly so that the service life of the plasma display panel 1 will be longer. Also, since the plasma gas contains xenon gas, the plasma display panel of the present invention has higher brightness.

1 . A method for manufacturing a protective film, comprising the step of forming a protective film containing SrO and CaO,
 wherein a first vapor deposition material having a main component which is SrO and a second vapor deposition material having a main component which is Cao are separately disposed inside a same vacuum chamber, and   wherein the amounts of vapor generated from the first and second vapor deposition materials are controlled and the first and second vapor deposition materials are vaporized such that the CaO content in the protective film will be at least 20 mol % and at most 90 mol %.   
     
     
         2 . The method for manufacturing a protective film according to  claim 1 , in which the protective film is formed over a first panel with a first electrode disposed on a surface thereof, and a second panel with a second electrode disposed on a surface thereof,
 wherein a dielectric film is disposed over at least one of the first and second electrodes, and   wherein the protective film is formed on a surface of the dielectric film by allowing each of the vapors of the first and second vapor deposition materials to reach the dielectric film.   
     
     
         3 . The method for manufacturing a protective film according to  claim 1 , wherein the first and second vapor deposition materials are vaporized while disposing the first vapor deposition material on a first hearth and disposing the second vapor deposition material on a second hearth different from the first hearth. 
     
     
         4 . The method for manufacturing a protective film according to  claim 1 , wherein the first and second vapor deposition materials are vaporized such that the CaO content in the protective film is at least 20 mol % and at most 90 mol %, by allowing an electron beam to emit from a first electron beam gun into the first vapor deposition material and by allowing an electron beam to emit from a second electron beam gun into the second vapor deposition material. 
     
     
         5 . A method for manufacturing a plasma display panel, comprising the steps of:
 separately disposing a first vapor deposition material containing SrO, and a second vapor deposition material containing CaO inside the same vacuum chamber;   forming a protective film containing SrO and CaO, with the CaO content being at least 20 mol % and at most 90 mol %, on the surfaces of first and second panels by heating the first and second vapor deposition materials while controlling the amounts of vapor generated; and   adhering the first and second panels together and sealing them,   wherein the steps at least from the step of forming the protective film to the sealing step are carried out in a vacuum atmosphere.   
     
     
         6 . The method for manufacturing a plasma display panel according to  claim 5 , wherein the first and second vapor deposition materials are heated while the first vapor deposition material is disposed on a first hearth and the second vapor deposition material is disposed on a second hearth different from the first hearth. 
     
     
         7 . The method for manufacturing a plasma display panel according to  claim 5 , wherein the first and second vapor deposition materials are vaporized and the amount of the vapor generated from the first and second vapor deposition materials are controlled such that the CaO content will be at least 20 mol % and at most 90 mol % by allowing an electron beam to emit from a first electron beam gun into the first vapor deposition material and by allowing an electron beam to emit from a second electron beam gun into the second vapor deposition material. 
     
     
         8 . A method for manufacturing a plasma display panel, the plasma display panel having a first panel and a second panel, a scanning electrode and a sustaining electrode being disposed on a surface of the first panel while being insulated from each other, an address electrode being disposed on a surface of the second panel and a fluorescent film being disposed on the address electrode,
 wherein an insert gas is charged in between the first and second panels, and by applying voltage between the address electrode and the scanning electrode, a write discharge occurs, and by applying AC voltage between the scanning electrode and the sustaining electrode, a sustaining discharge is brought about, and ultraviolet rays discharged from the plasma which is generated by the sustaining discharge are irradiated to the fluorescent film, thereby being emitted, the method for manufacturing a plasma display panel comprising the steps of:   separately disposing a first vapor deposition material having a main component which is SrO and a second vapor deposition material having a main component which is CaO inside a same vacuum chamber;   forming a protective film having the CaO content with at least 20 mol % and at most 90 mol % on the scanning electrode and the sustaining electrode by controlling the amount of vapor generated from the first and second vapor deposition materials; and   adhering the first and second panels together and sealing them.   
     
     
         9 . The method for manufacturing a plasma display panel according to  claim 8 , wherein the steps at least from the step of forming the protective film to the sealing step are carried out in a vacuum atmosphere.