Abstract:
An electrode structure for a front board of a plasma display panel (PDP). The electronic structure connects all the sustain electrodes on the front board to prevent data transformation errors caused by holes. The fabrication method of the electronic structure is also disclosed.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an electrode structure, and more particularly to an electrode structure appropriate for a front board of a plasma display panel (PDP) and fabrication method thereof.  
         [0003]     2. Description of the Related Art  
         [0004]     PDPs are generally divided into alternating current (AC) and direct current (DC) types. The AC type PDP comprises a front board and a back board. Bus electrodes are formed on the front board. Data electrodes are formed on the back board. The front and back boards are typically glass substrates. The bus electrodes are composed of photosensitive electrode material.  
         [0005]     In order to increase the shading values of pixels, the bus electrodes utilize two coats of a screen printing material. As shown in  FIG. 1   a , a dark color electrode material covers a front board  1  to form a dark color layer  3  and a light color electrode material covers the dark color layer  3  to form a light color layer  5 .  
         [0006]     The dark color electrode material is ruthenium and the light color electrode material is silver. The electrode material of the dark color layer  3  and the light color layer  5  is different such that shrinkage of the dark color layer  3  and light color layer  5  is not the same. As shown in  FIG. 1   b , if the shrinkage of the dark color electrode material is more than the light color electrode material, edges of the front board  1  with curl.  
         [0007]     In order to solve the uneven shrinkage problem, a conventional method is used to control areas of the dark color layer  3  and the light color layer  5 .  FIG. 2   a  shows a conventional front board. A dark color layer  4  is formed on a front board  2  and a light color layer  6  is formed on the dark color layer  4 . The area of the light color layer  6  is greater than the area of the dark color layer  4 . When a scraper of a screen printing tool contacts the light color layer  6  moving from left to right, a hole  8  is generated in a left terminal of the dark color layer  4 , as shown in  FIG. 2   b.    
         [0008]      FIG. 2   c  shows a top view of a conventional front board. An electrode pattern comprising electrodes X 1 ˜X n  is formed in the front board. When the hole  8  appears in the electrode X 1 , the electrode X 1  is cut off and malfunctions resulting in reduced PDP yield of the PDP to reduce.  
       SUMMARY OF THE INVENTION  
       [0009]     An object of the present invention is to provide an electrode structure and an electrode fabrication method for preventing electrodes hole cut-off.  
         [0010]     Accordingly, the present invention provides an electrode fabrication method. First, a substrate comprising a first region and a second region is provided. A first conductive layer is then formed overlying the first region. Next, a second conductive layer is formed overlying the first region and the second region. Finally, the second conductive layer and the underlying first conductive layer are patterned to form an electrode pattern. The electrode pattern comprises a first electrode line, a second electrode line, and a connection segment. The first electrode line and the second electrode line are disposed in parallel and formed on the first region and the second region. The connection segment connects the first electrode line and the second electrode line in the first region.  
         [0011]     Accordingly, the present invention also provides a front board of a plasma display panel (PDP). A first region and a second region are defined on the front board. The first region is capable of displaying an image and the second region has a display driving circuit. The electrode structure comprises at least two electrode lines disposed in parallel and a connection segment. Each electrode line comprises a first segment and a second segment. The structures of the first segment and the second segment are different. The first segment is formed on the first region and the second segment on the second region. The connection segment is formed on the first region for connecting the electrode lines. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention can be more fully understood by reading the subsequent detailed description and examples with reference made to the accompanying drawings, wherein:  
         [0013]      FIGS. 1   a  to  1   b  are cross-sections showing a conventional electrode fabrication method;  
         [0014]      FIGS. 2   a  to  2   c  are cross-sections showing another conventional electrode fabrication method;  
         [0015]      FIGS. 3   a  to  3   d  are cross-sections showing an electrode fabrication method of the present invention;  
         [0016]      FIG. 4  is a top-view of the electrode structure of a second embodiment;  
         [0017]      FIG. 5  is a top-view of the electrode structure of a third embodiment;  
         [0018]      FIG. 6  is a top-view of the electrode structure of a fourth embodiment;  
         [0019]      FIG. 7  is a top-view of the electrode structure of a fifth embodiment;  
         [0020]      FIG. 8  is a top-view of the electrode structure of a sixth embodiment;  
         [0021]      FIG. 9  is a top-view of the electrode structure of a seventh embodiment;  
         [0022]      FIG. 10  is a structural diagram of a front board of a PDP. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]      FIGS. 3   a  to  3   d  are cross-sections showing an electrode fabrication method of the present invention. First, in  FIG. 3   a , a glass substrate  100  comprises a first region  11 , a second region C 1  and a third region C 2 . The first region  11  comprises a display region A and a buffer region B. Bus electrodes comprise sustain electrodes and scan electrodes. A sustain electrode driving circuit is disposed in the second region C 1 . A scan electrode driving circuit is disposed in the third region C 2 . The buffer region B is disposed between the display region A and the second region C 1 .  
         [0024]     Next, as shown in  FIG. 3   b , a first conductive layer  110  is formed overlying the display region A and the buffer region B.  
         [0025]     Next, as shown in  FIG. 3   c , a second conductive layer  120  is formed overlying the display region A, the buffer region B, the first region C 1  and the third region C 2 . A scraper of a screen printing tool moves from a left terminal to a right terminal of the glass substrate  100  such that the second conductive layer  120  completely covers the glass substrate  100  and the first conductive layer  110 . Generally, the first conductive layer  110  is a dark color layer and the second conductive layer  120  is a light color layer.  
         [0026]     Finally in  FIG. 3   d , the first electrode layer  110  and the second electrode layer  120  are patterned to form an electrode pattern on the glass substrate  100 . The display region A and the buffer region B have the first conductive layer  110  and the second conductive layer  120 . The first region C 1  and the third region C 2  have only the second conductive layer  120 .  
         [0027]     The electrode pattern comprises sustain electrodes X 1 ˜X 6  and connection segments CON 1 ˜CON 5 . The sustain electrodes X 1 ˜X 6  are connected in parallel. The connection segments CON 1 ˜CON 5  are formed in the buffer region B and connect to the sustain electrodes X 1 ˜X 6 . For example, the connection segment CON 1  connects the sustain electrodes X 1  and X 2 , and the connection segment CON 2  connects the sustain electrodes X 2  and X 3 . The electrode pattern further comprises scan electrodes Y 1 ˜Y 6  between the sustain electrodes X 1 ˜X 6 . The scan electrodes Y 1 ˜Y 6  are formed in the display region A and the third regions C 2 .  
         [0028]     A sustain driver  130  outputs identical sustain signals to the sustain electrodes X 1 ˜X 6 . If a hole  8  occurs in a right terminal of the second region C 1  of the sustain electrodes X 1 , the sustain signal is received through the connection segment CON 1 . When a hole occurs in any one sustain electrode, the sustain signal is received through connection segments.  
         [0029]     In this embodiment, although the connection segments CON 1 ˜CON 5  are formed in the buffer region B and connected to the sustain electrodes X 1 ˜X 6 , the present invention neither limits the location of the connection segments CON 1 ˜CON 5  nor the connection relationship between the connection segments CON 1 ˜CON 5  and the sustain electrodes X 1 ˜X 6 .  
         [0030]     Various connection methods are disclosed in the following.  FIG. 4  is a top-view diagram of the electrode structure of a second embodiment of the invention. The connection segments CON 1 ˜CON 5  connect the sustain electrodes X 1 ˜X 6  covering the entire buffer region B. If a hole  8  occurs in the right terminal of the second region C 1  of the sustain electrodes X 1 , the sustain signal is received through the connection segment CON 1 .  
         [0031]      FIG. 5  is a top-view diagram of the electrode structure of a third embodiment. The connection segments CON 1 ˜CON 3  cover a portion of the buffer region B. The connection segment CON 1  connects the sustain electrodes X 1  and X 2 . The connection segment CON 2  connects the sustain electrodes X 3  and X 4 . The connection segment CON 3  connects the sustain electrodes X 5  and X 6 . Therefore, each sustain electrode is connected to the neighboring sustain electrode through at least one connection segment. If a hole  8  occurs in the right terminal of the second region C 1  of the sustain electrodes X 1 , the sustain signal is received through the connection segment CON 1 .  
         [0032]     A characteristic of the present invention is that each sustain electrode is connected to one or more sustain electrodes through the connection segment.  
         [0033]      FIG. 6  is a top-view diagram of the electrode structure of a fourth embodiment. The connection segments CON 1 ˜CON 5  connect the sustain electrodes X 1 ˜X 6 , and cover part of the buffer region B and part of the second regions C 1 .  
         [0034]      FIG. 7  is a top-view diagram of the electrode structure of a fifth embodiment. The connection segments CON 1 ˜CON 3  cover a portion of the buffer region B and a portion of the second regions C 1 . In the buffer region B, the connection segments CON 1 ˜CON 3  comprise the first conductive layer  110  and the second conductive layer  120 . In the second regions C 1 , the connection segments CON 1 ˜CON 3  have only the second conductive layer  120 . The connection segment CON 1  connects the sustain electrodes X 1  and X 2 . The connection segment CON 2  connects the sustain electrodes X 3  and X 4 . The connection segment CON 3  connects the sustain electrodes X 5  and X 6 .  
         [0035]      FIG. 8  is a top-view diagram of the electrode structure of a sixth embodiment. The connection segments CON 1 ˜CON 5  connect the sustain electrodes X 1 ˜X 6 , and cover a portion of the buffer region B and the greater portion of the second regions C 1 .  
         [0036]      FIG. 9  is a top-view diagram of the electrode structure of a seventh embodiment. The connection segments CON 1 ˜CON 3  connect the sustain electrodes X 1 ˜X 6 , and cover a portion of the buffer region B and the greater portion of the second regions C 1 . The connection segment CON 1  connects the sustain electrodes X 1  and X 2 . The connection segment CON 2  connects the sustain electrodes X 3  and X 4 . The connection segment CON 3  connects the sustain electrodes X 5  and X 6 .  
         [0037]      FIG. 10  is a structural diagram of a front board of a PDP. The front board  100  comprises first region  11  and second region C 1 . The first region  11  is capable of displaying an image. The second region C 1  has a sustain driver  130 . The bus electrodes of the front board  100  comprise sustain electrodes X 1 ˜X n  and scan electrodes Y 1 ˜Y n .  
         [0038]     Sustain electrodes X 1 ˜X n  are disposed in parallel. Each sustain electrode comprises a first segment formed on the first region  11  and a second segment formed on the second region C 1 . The first region  11  has a laminated construction with first conductive material layer. The second region C 1  has only second conductive material layer. Connection segments CON 1 ˜CON n-1  form on the first region  11  for connecting sustain electrodes X 1 ˜X n .  
         [0039]     The first region  11  comprises display region A for displaying an image and buffer region B between the first region  11  and second region C 1  for disposing connecting connection segments CON 1 ˜CON n-1 . In this embodiment, connection segments CON 1 ˜CON n-1  form on a portion of buffer region B and second region C 1 .  
         [0040]     In addition, the front board  100  further comprises scan electrodes Y 1 ˜Y n  controlled by a scan driver  140  and formed on display region A and third region C 2 .  
         [0041]     When a hole  8  occurs in the right terminal of the second region C 1  of any one sustain electrode, the sustain electrode also receives the sustain signal through the connection segment.  
         [0042]     While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.