Abstract:
There are provided a plasma display panel (PDP) wherein a seam area is minimized, so that continuity of screens can be stably ensured, and a method of fabricating the same. In the PDP formed by assembling a plurality of unit PDPs, each of the unit PDPs includes front and rear substrates; a sealant formed on the side surfaces of the front and rear substrates; side electrodes formed on the sealant; and functional layers formed on the rear surface of the rear substrate and the side surfaces of the front and rear substrates.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to PCT Application No. PCT/KR2008/002146 filed on 2008 Apr. 16 and Korean Patent Application No. 10-2007-0038817 filed on 2007 Apr. 20, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which in its entirety are herein incorporated by reference. 
     BACKGROUND 
     1. Field 
     The present invention relates to a multi plasma display panel (PDP) and a method of fabricating the same, and more particularly, to a multi PDP wherein a seam area is minimized, so that continuity of screens can be stably ensured, and a method of fabricating the same. 
     2. Description of the Related Art 
     Display devices are becoming larger in size, and the plasma display panel (PDP) is no exception in that regard. However, there is a limit in increasing the size of a PDP using only one glass substrate. Therefore, recently, a multi plasma display panel has appeared, in which PDPs with a predetermined size are assembled continuously. 
     Such a multi PDP has an advantage in that the display area of the multi PDP are extended, and respective PDPs can be controlled individually to display different screens. 
     However, as the multi PDP is configured by assembling several PDPs, no image is formed at the joint between the PDPs, i.e., a seam area, and therefore, continuity of screens may be degraded. 
     SUMMARY 
     The present invention has been conceived to solve the aforementioned problems. Accordingly, an object of the present invention is to provide a PDP wherein a seam area is minimized, so that continuity of screens can be stably ensured, and a method of fabricating the same. 
     According to an aspect of the present invention, there is provided a PDP, includes: front and rear substrates; a sealant formed on side surfaces of the front and rear substrates; side electrodes formed on the sealant; and functional layers formed on the rear surface of the rear substrate and the side surfaces of the front and rear substrates. 
     According to another aspect of the present invention, there is provided a method of fabricating a PDP includes the steps of: stacking and laminating front and rear substrates together and forming a sealant on side surfaces of the front and rear substrates; sealing front and rear substrates together by the sealant; polishing the sealant; forming side electrodes on the sealant; forming a moisture proof layer on the rear surface of the rear substrate and the side surfaces of the front and rear substrates; forming an insulating layer on the moisture proof layer; forming an EMI (electromagnetic interference) shielding layer on the insulating layer; and forming a protection layer on the EMI shielding layer. 
     According to the present invention, by polishing the sealant and simplifying the configuration of function layers, the seam area in a PDP can be minimized, and therefore, continuity of screens can be stably ensured. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a PDP according to an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view of a PDP taken along line A-A′ of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of a PDP taken along line B-B′ of  FIG. 1 ; 
         FIG. 4  is a flowchart illustrating the process of fabricating a PDP according to an embodiment of the present invention; and 
         FIGS. 5 to 11  are cross-sectional views illustrating the method of fabricating a PDP according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a PDP and a method of fabricating the same, according to embodiments of the present invention, will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view of a PDP according to an embodiment of the present invention, and  FIGS. 2 and 3  are cross-sectional views of a PDP taken along lines A-A′ and B-B′ of  FIG. 1 , respectively. 
     As shown in  FIG. 1 , the PDP  100  according to an embodiment of the present invention is configured by assembling a plurality of unit PDPs  200 . As the plurality of unit PDPs  200  are assembled, a seam area S exists at the joint portion of the unit PDPs. 
     The configuration of the unit PDP  200  will be described below. As shown in  FIGS. 2 and 3 , the unit PDP  200  basically has a configuration in which a front plate  210  and a rear substrate  220  are sequentially stacked and laminated together. Although not shown in these figures, through a preparation process, a scan electrode, a sustain electrode, a dielectric layer, a protection layer, and the like are formed on the front substrate  210 , and an address electrode, a dielectric layer, a rib, a phosphor layer, and the like are formed on the rear substrate  220 . In  FIG. 2 , an inner front electrode  211  is formed on the front substrate  210 , and a first side front electrode  212  is formed on the side surface of the front substrate  210 . The inner front electrode  211 , an outer front electrode  221  and the first side front electrode  212  are electrodes having the same function as any one of the scan and sustain electrodes. An optical film  230  is further formed on the front surface of the front substrate  210 . 
     For reference, an outer dielectric layer  222  may further be formed on the rear surface of the rear substrate  220 . 
     A sealant  201  for isolating an inner space between the front and rear substrates  210  and  220  from an external environment is formed on side surfaces of the front and rear substrates  210  and  220 . A second side front electrode  202  having the same function as the inner front electrode  211 , the outer front electrode  221  and the first side front electrode  212  is formed on the sealant  201 . 
     In the sate that the front and rear substrates  210  and  220  are assembled together, and the sealant  201  and the second side front electrode  202  are formed on the side surfaces of the front and rear substrates  210  and  220 , functional layers are formed on the rear surface of the rear substrate  220  and the side surfaces of the front and rear substrates  210  and  220 , so that the exposed outer front electrode  221  and the second side front electrode  202  are protected, and the stacked and laminated state of the front and rear substrates  210  and  220  is maintained stably, isolated from the external physical environment. 
     Specifically, the functional layers include a moisture proof layer  240 , an insulating layer  250 , an EMI shielding layer  260  and a protection layer  270 . The moisture proof layer  240  is formed on the rear surface of the rear substrate  220  and the side surfaces of the front and rear substrates  210  and  220 . The moisture proof layer  240  functions to protect the outer front electrode  221  and the second side front electrode  202 , in other words, the sustain, bus and address electrodes, to prevent the second side front electrode  202  from migrating due to moisture absorption, and to prevent the second side front electrode  202  and the EMI shielding layer  260  from being electrically shorted. The moisture proof layer  240  may be formed of any one of acryl, urethane and epoxy, or a combination thereof. 
     The insulating layer  250  is formed on the moisture proof layer  240  to prevent the outer front electrode  221  and the second side front electrode  202  from being electrically shorted. 
     The EMI shielding layer  260  is formed on the insulating layer  250  so as to shield electromagnetic interference generated from the rear surface of the rear substrate  220  and the side surfaces of the front and rear substrates  210  and  220 . Preferably, the EMI shielding layer  260  is formed of a metallic material with high electric conductivity. The material used in the EMI shielding layer  260  may include any one of Ag, Cu, Pt, Au and AI, or a combination thereof. 
     The protection layer  270  is formed on the EMI shielding layer  260 , and basically functions to protect the unit PDP including the front and rear substrates  210  and  220  against external physical impact and to isolate the EMI shielding layer  260  from the outside electrically. The protection layer  270  may be formed of a material the same as or different from the moisture proof layer  240 . Specifically, the protection layer  270  may be formed of any one of acryl, urethane and epoxy, or a combination thereof. 
     In the aforementioned configuration of  FIG. 2 , the inner front electrode  211  formed on the front substrate  210 , i.e., the scan and the sustain electrodes, is drawn toward the outside.  FIG. 3  is a cross-sectional view illustrating an inner rear electrode  211   a  formed on the rear substrate  220 , i.e., an address electrode drawn toward the outside, in which the inner rear electrode  211   a  is drawn toward the outside through a side rear electrode  212   a  formed on the side of the rear substrate  220  and an outer rear electrode  221   a , unlike the inner front electrode  211 . The configuration of  FIG. 3  is the same as that of  FIG. 2 , except that the inner rear electrode  211   a  is drawn toward the outside through the side rear electrode  212   a  and the outer rear electrode  221   a . Therefore, detailed description will be omitted. For reference, the side electrode formed on the side surfaces of the front and rear substrates is subdivided into the first and second side front electrodes and the side rear electrode shown in  FIG. 3 . 
     The configuration of the PDP according to the embodiment of the present invention has been described above. Hereinafter, a method of fabricating a PDP according to an embodiment of the present invention will be described.  FIG. 4  is a flowchart illustrating the process of fabricating a PDP according to an embodiment of the present invention, and  FIGS. 5 to 11  are cross-sectional views illustrating the method of fabricating a PDP according to the embodiment of the present invention, which shows a method of forming front electrodes (scan and sustain electrodes). 
     As shown in  FIGS. 4 and 5 , after the preparation process has been completed (S 401 ), front and rear substrates  210  and  220  are stacked and laminated together (S 402 ), and a sealant  201  is formed on the side surfaces of the front and rear substrates  210  and  220 . The front and rear substrates  210  and  220  are sealed together by the sealant. Here, as described above in the preparation process, a scan electrode, a sustain electrode, a dielectric layer, a protection layer, and the like are formed on the front substrate  210 . In  FIG. 5 , an inner front electrode  211  is formed on the front substrate  210 , and a first side front electrode  212  is formed on the side surface of the front substrate  210 . The inner front electrode  211 , an outer front electrode  221  and the first side front electrode  212  are electrodes having the same function as any one of the scan and sustain electrodes. For reference, an outer dielectric layer  222  may be further formed on the rear surface of the rear substrate  220 . 
     The sealant  201  is coated on the side surfaces of the front and rear substrate  210  and  220 , and then a process of polishing the sealant is performed (S 403 ). Through the process of polishing the sealant  201 , the thickness of the sealant  201  is decreased. Consequently, the seam area can be reduced. 
     After the process of polishing the sealant  201  has been completed, a second side front electrode  202  is formed on the polished sealant  201  (S 404 ). The second side front electrode  202  is the same electrode as the inner front electrode  211 , the outer front electrode  221  and the first side front electrode  212  as described above. The second side front electrode  202  is any one of the scan and sustain electrodes. 
     Thereafter, an optical film  230  is coated on the entire surface of the front substrate  210  (S 405 ). Subsequently, a moisture proof layer  240  is formed on the rear surface of the rear substrate  220  and the side surfaces of the front and rear substrates  210  and  220  (S 406 ). Specifically, the moisture proof layer  240  may be formed by coating a material for the moisture proof layer  240  using any one of a dipping method, a dispensing method, a spraying method, or a combination thereof, and then curing the material using any one of ultraviolet radiation, thermal treatment, natural drying, or a combination thereof. Here, the material for the moisture proof layer  240  is any one of acryl, urethane and epoxy. 
     The moisture proof layer  240  formed using such a method functions to protect the outer front electrode  221  and the second side front electrode  202 , in other words, the sustain, bus and address electrodes, to prevent the second side front electrode  202  and the outer front electrode  221  from migrating due to moisture absorption, and to prevent an EMI shielding layer  260  from being electrically shorted with the electrodes. 
     Subsequently, the optical film  230  coated on the entire surface of the front substrate  210  is cut to have a proper size, and an insulating layer  250  is then formed on the moisture proof layer  240  (S 407 ). The insulating layer  250  functions to prevent the outer front electrode  221  and second side front electrode  202  from being electrically shorted with the EMI shielding layer  260 . 
     Thereafter, the EMI shielding layer  260  is formed on the insulating layer  250  (S 408 ). The EMI shielding layer  260  functions to shield electromagnetic interference generated from the rear surface of the rear substrate  220  and the side surfaces of the front and rear substrates  210  and  220 . Preferably, the EMI shielding layer  260  is formed of a material which has high electric conductivity and is does not chemically react with other components. Specifically, the material may include any one of Ag, Cu, Pt, Au, Al, Pb, Cr, Ni, or a combination thereof. 
     The EMI shielding layer  260  may be formed by coating an EMI shielding material using any one of a dipping method, a dispensing method, a spraying method, a brushing method, or a combination thereof, and then curing the EMI shielding material using any one of ultraviolet radiation, thermal treatment, natural drying, or a combination thereof. Here, the EMI shielding layer  260  is to be laminated with the optical film  230 , and electromagnetic waves collected from the optical film  230  are eliminated through an external ground connected to the rear surface of the rear substrate  220  via the EMI shielding layer  260 . 
     Finally, a protection layer  270  is finally formed on the EMI shielding layer (S 409 ). The protection layer  270  may be formed of the same material as that constituting the moisture proof layer  240 , and the method of forming the moisture proof layer  240  may be employed to form the protection layer  270 . That is, the protection layer may be formed by coating an EMI shielding material using any one of a dipping method, a dispensing method, a spraying method, a brushing method, or a combination thereof, and then curing the EMI shielding material using any one of ultraviolet radiation, thermal treatment, natural drying, or a combination thereof. 
     As described above, the method of fabricating a PDP has been described with respect to the drawing of front electrodes, i.e., scan and sustain electrodes, and the configuration of functional layers. A description about the method of fabricating a PDP with respect to the drawing of the rear electrode, i.e., an address electrode, and the configuration of functional layers will be omitted. It because the drawing structure of the rear substrate is only slightly different from that of the front substrate, but the rear substrate electrode is the same as the front electrode in forming the functional layers. 
     The present invention relates to a PDP and a method of fabricating the same, and more particularly, to a PDP wherein a seam area is minimized, so that continuity of screens can be stably ensured, and a method of fabricating the same.