Abstract:
A plasma display panel is disclosed. The plasma display panel having an additional thin layer between each electrode and a glass substrate in an electrode pad region minimizes migration of the electrode which results from a potential difference between the electrodes while the PDP is driven.

Description:
TECHNICAL FIELD  
       [0001]     The present invention generally relates to a plasma display panel, and more specifically, to an AC plasma display panel where an electrode of an electrode pad is not directly formed on a glass substrate but an additional thin layer is formed between the glass substrate and the electrode of the electrode pad, thereby minimizing migration of electrodes.  
       BACKGROUND ART  
       [0002]     A plasma display panel (hereinafter, referred to as “PDP”) has a panel formed by sealing two substrates spaced from each other at a predetermined distance. The space between two substrates is filled with discharge gas. A group of electrodes, which are formed on each substrate has its end portion extended to an external end portion of the substrate for connection with external driving circuits. This connection region of the electrode group is entitled as an electrode pad.  
         [0003]     Generally, an electrode of the electrode pad which is formed of metal having low resistance such as silver (Ag) is directly formed on a glass substrate in a prior art. In driving this PDP, a potential difference is generated between the electrodes, this potential difference leading ions of each electrode to being combined with a metal electrode of the glass substrate. Therefore, the adjacent electrodes are shorted, which is called migration.  
         [0004]      FIG. 1  is a diagram illustrating migration generated from electrode pads of a conventional plasma display panel.  
         [0005]     When an electric field is applied to metal, the metal in an anode is dissolved and moves through non-metal material to a cathode due to effect of the electric field. This phenomenon may cause short between the metal electrodes.  
         [0006]      FIG. 2  is a diagram illustrating the actual shape of the migration generated between electrodes.  
         [0007]     When electrodes X and Y are fetched to the same electrode pad in order to embody a large multi-screen having four plasma display panels connected seamlessly, the interval between the electrodes becomes narrower so that the short between the electrodes which results from the migration becomes a serious problem.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a diagram illustrating migration generated from an electrode pad of a conventional plasma display panel.  
         [0009]      FIG. 2  is a diagram illustrating the actual shape of the migration generated between electrodes.  
         [0010]      FIG. 3  is a diagram illustrating an electrode pad of a plasma display panel according to a first embodiment of the present invention.  
         [0011]      FIG. 4  is a diagram illustrating an electrode pad of a plasma display panel according to a second embodiment of the present invention.  
         [0012]      FIG. 5  is a diagram illustrating an electrode pad of a plasma display panel according to a third embodiment of the present invention.  
         [0013]      FIG. 6  is a diagram illustrating an electrode pad of a plasma display panel according to a fourth embodiment of the present invention.  
         [0014]      FIG. 7  is a diagram illustrating an electrode pad of a plasma display panel according to a fifth embodiment of the present invention.  
         [0015]      FIG. 8  is a diagram illustrating an electrode pad of a plasma display panel according to a sixth embodiment of the present invention.  
         [0016]      FIG. 9  is a cross-sectional diagram illustrating the cross section cut in a direction A-A′ of  FIG. 6 .  
         [0017]      FIG. 10  is a diagram illustrating an electrode pad of a plasma display panel according to a seventh embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0000]     Technical Subject  
         [0018]     Accordingly, it is an object of the present invention to minimize migration by forming an additional thin layer between a glass substrate and each electrode of an electrode pad.  
         [0019]     Technical Solution  
         [0020]     There is provided a plasma display panel including a front substrate and a rear substrate, which each has side portion extended in a different direction. This side portion becomes an electrode pad region where electrodes of the substrate are fetched to be coupled with an external driving circuit. The plasma display panel comprises at least one or more additional thin layers formed between the electrode and the substrate for preventing the electrode of the electrode pad region from being directly contacted with the substrate.  
       PREFERRED EMBODIMENTS  
       [0021]     The present invention will be described in detail with reference to the accompanying drawings.  
         [0022]     FIGS.  3  to  5  are diagrams illustrating an electrode pad of a plasma display panel according to first to third preferred embodiment of the present invention.  
         [0023]     In an embodiment, a thin layer  20  (hereinafter, referred to as “additional thin layer”) is additionally formed between a glass substrate  10  and electrodes X (X 1 , X 2 , . . . ) and Y (Y 1 , Y 2 , . . . ) fetched in the electrode pad region, so that metal ions (i.e. Ag) of each electrode X and Y may not be flow into the glass substrate  10 .  
         [0024]     First to third embodiments disclosed in FIGS.  3  to  5  presumes that the electrode X (X 1 , X 2 , . . . ) is fetched in an opposite direction to that of the electrode Y (Y 1 , Y 2 , . . . ). And, each of FIGS.  3  to  5  illustrates example in which the length of the additional thin layer is different from each other.  
         [0025]     The width of the additional thin layer  20  is larger than or the same as that of the electrode X or Y of the electrode pad, and is formed with the same shape that of the electrode X or Y fetched to the electrode pad so that the electrodes X and Y may not be directly contacted with the glass substrate  10 . The additional thin layer in the embodiments is formed with a belt type having a predetermined length toward the internal direction of the panel. Each of the additional thin layers  20  is separated from other adjacent additional thin layers  20  not to be connected with each other.  
         [0026]     The additional thin layer  20  may be formed of the same material as a transparent substrate ITO (not shown) formed in a display region (not shown) of the plasma display panel. The material used in the transparent substrate ITO is used as the additional thin layer  20  so that an additional process or material for formation of the additional thin layer  20  is not required. That is, when the transparent substrate ITO (not shown) is formed in the display region (not shown), the additional thin layer  20  is patterned with the transparent substrate ITO. Unlike the embodiments disclosed in  FIGS. 3 and 4 , the ITO film in the display region is connected with the additional thin layer  20  in the embodiment of  FIG. 5 .  
         [0027]     Since the ITO is formed with a pure crystalline type on the substrate, and has low moisture and reactivity, the migration phenomenon can be remarkably prevented.  
         [0028]     FIGS.  6  to  8  are diagrams illustrating an electrode pad of a plasma display panel according to fourth to sixth preferred embodiments of the present invention.  
         [0029]     In the preferred embodiments of FIGS.  6  to  8 , electrodes X and Y are fetched to one direction for displaying a plurality of plasma display panels seamlessly with a large screen.  
         [0030]     Here, a multi-plasma display panel is exemplified where the electrodes X and Y are fetched only to one direction so that they may be displayed to the edge of the opposite side to minimize the width between the display regions.  
         [0031]     Since the electrodes X and Y are fetched only to one direction in this preferred embodiment, the width between the electrodes becomes narrower than in the first to second preferred embodiments. As a result, the structure of the electrode becomes weak to the migration. Therefore, the additional thin layer  20  is more required in the electrode structure of the preferred embodiment.  
         [0032]     The explanation on formation of the additional thin layer  20  of the preferred embodiment is omitted because it is the same as that of the first to third preferred embodiments.  
         [0033]      FIG. 9  is a cross-sectional diagram illustrating the cross section cut in a direction A-A′ of  FIG. 6 . The additional thin layer  20  having a predetermined length is formed on the glass substrate  10  of the electrode pad, and then the electrode Y 2  is formed thereon. Here, since the additional thin layer ITO  20  may be formed of a thin film, limit by the height of the additional thin layer  20  is not generated when other structures are formed.  
         [0034]     Additionally, suppose that the additional thin layer  20  is formed of the same material as that of the transparent substrate ITO (not shown) of the display region (not shown). When the transparent substrate ITO (not shown) is formed in the display region, the additional thin layer  20  is formed together so that an additional process is not required.  
         [0035]     In the above-described embodiments, the additional thin layers  20  are formed to correspond one by one to the electrodes X and Y, respectively, so that each of the additional thin layers  20  may be separated from each other because the additional thin layer  20  is formed of the same material as that of the transparent substrate ITO. Therefore, when the additional thin layer is formed with insulating material with which a thin film is fabricated, the additional thin layers are not separated to correspond one-by-one to the electrodes X and Y. Instead, an additional thin layer  40  may be formed to correspond to the whole electrodes X and Y as shown in  FIG. 10 .  
         [0036]     In case of FIGS.  6  to  8 , when the additional thin layer is formed of insulating material, an additional thin layer corresponding to all electrodes X and Y can be formed.  
       INDUSTRIAL APPLICABILITY  
       [0037]     As discussed earlier, in a plasma display panel according to an embodiment of the present invention, an electrode of an electrode pad is formed on an additional thin layer of a thin film, thereby minimizing migration of electrodes.