Abstract:
A method for manufacturing electrodes of a plasma display panel includes providing a front transparent substrate including transparent electrodes on the front transparent substrate, coating a black photosensitive paste film and a main photosensitive conductive paste film of negative-working type on the transparent electrodes, exposing the black photosensitive paste film and main photosensitive conductive paste film to define bus electrodes on the transparent electrodes, wherein exposure energy acting on main regions of the bus electrodes is greater than exposure energy acting on edge regions of the bus electrodes, developing the black photosensitive paste film and main photosensitive conductive paste film to form the bus electrodes, in which a thickness of the edge regions of the bus electrodes is less than a thickness of the main regions of the bus electrodes, and firing the black photosensitive paste film and main photosensitive conductive paste film.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a continuation application of U.S. application Ser. No. 10/907,832 filed Apr. 18, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a method for manufacturing electrodes of a plasma display panel (hereafter referred as PDP), and more particularly, to a method for manufacturing electrodes for preventing electrodes from experiencing edge curl effects and for increasing the quality of the PDP.  
         [0004]     2. Description of the Prior Art  
         [0005]     Recently, the field of multimedia applications is developing quickly. Users have a great demand for entertainment equipment. Conventionally, the cathode ray tube (CRT) display is commonly used. However, the cathode ray tube display does not meet the needs of multimedia technology because of it has a large volume. Therefore, many flat panel display technologies such as liquid crystal display (LCD), PDP, and field emission display (FED) have been developed. These display technologies are capable of manufacturing a thin, light, short and small monitor, and thus these technologies are going to be the mainstream technology for the future. Among these technologies, the PDP is attracting attention in the field of displays as a full-color display apparatus having a large size display area and is especially popular for use as a large size television or an outdoor display panel. This is because of its capability of serving as a high quality display resulting from the fact that it is a self-light emitting type display, has a wide angle of visibility, and has a short response time. Furthermore, the dimensions of the PDP can easily be increased in scale due to its simplicity in the manufacturing process.  
         [0006]     A color PDP is a display in which ultraviolet rays are produced by gas discharge to excite phosphors so that visible lights are emitted therefrom to perform a display operation. Generally, a 3-electrode type PDP including a common electrode, a scan electrode and an address electrode is employed in the AC type PDP.  
         [0007]     In a conventional 3-electrode AC type PDP, the address electrodes are disposed between parallel barrier ribs on a rear substrate. A plurality pair of conductive electrodes are arranged in parallel, and each pair of the conductive electrodes, including the common electrode and the scan electrode, is disposed in a direction perpendicular to the address electrodes and barrier ribs, thereby a plurality of ruminant cells are scaled therein.  
         [0008]     The common and scan electrodes generally include a transparent electrode and a bus electrode. The transparent electrode is formed by the material indium tin oxide (ITO) (e.g., a mixture of In 2 O 3  and SnO 2 ). The conductivity of the transparent electrode is low in comparison with that of metal and therefore a narrow width and fine conductive layer is added as the bus electrode on the transparent electrode to enhance its conductivity. The gap between the common electrode and scan electrode is set to obtain preferred fire voltage. A sustaining voltage is applied to the common electrode and the scan electrode to drive the PDP.  
         [0009]     According to the above description, we know that electrodes are key units of a PDP and thus the method for manufacturing electrodes is very important. Please refer to  FIG. 1  to  FIG. 3 .  FIG. 1  to  FIG. 3  are schematic diagrams for illustrating a method for manufacturing electrodes of a PDP according to the prior art. As shown in  FIG. 1 , a front substrate  10 , for example, glass or other transparent boards, is provided. Transparent electrodes  12  and  14  formed by the material of ITO are disposed on the front substrate  10  and a discharge gap  16  is present between the transparent electrodes  12  and  14 . A black photosensitive paste film  18  of negative-working type and a main photosensitive conductive paste film  20  of negative-working type cover the front substrate  10 , the transparent electrode  12 , and the transparent electrode  14 . Then, utilizing a photo mask  22 , an exposure process is performed. The photo mask  22  includes a shade region  24  and an opening region  26 . In the exposure process, light  27 , for example, a collimated ultraviolet (UV) light passes through the opening region  26  and is blocked by the shade region  24 .  
         [0010]     As shown in  FIG. 2 , after the exposure process, a development process is performed for patterning the black photosensitive paste film  18  and the main photosensitive conductive paste film  20 . Because the black photosensitive paste film  18  and the main photosensitive conductive paste film  20  are negative-working type, areas covered by the shade region  24  are removed to form bus electrodes  28  and  30 . Since the exposure of the bottom region of the bus electrodes  28  and  30  is less than the exposure of the top region of the bus electrodes  28  and  30 , especially in the edges of the bus electrodes  28  and  30 , the bus electrodes  28  and  30  look like trapezoids, in which an upper side is wider than a lower side.  
         [0011]     As shown in  FIG. 3 , a firing process is performed. A tensile force occurs while high temperature firing and causes the edges of the bus electrodes  28  and  30  to not adhere to the transparent electrodes  12  and  14  well. Therefore, edge curls  32 ,  34 ,  36 , and  38  of the bus electrodes  28  and  30  occur.  
         [0012]     In the prior art, the height of the edge curls  32 ,  34 ,  36 , and  38  is approximately 1-10 microns and the thickness of the buses  28  and  30  is approximately 2-20 microns. A dielectric layer cannot easily be formed under the edge curls  32 ,  34 ,  36 , and  38  and air bubbles will be formed, causing breakdown around the edge curls  32 ,  34 ,  36 , and  38 . This will seriously influence the quality of the PDP. There are two methods for improving the edge curls  32 ,  34 ,  36 , and  38 : decreasing the thickness of the bus electrodes  28  and  30  and changing the component of the black photosensitive paste film  18  and the main photosensitive conductive paste film  20  to increase the adhesion ability between the bus electrodes  28  and  30  and the transparent electrodes  12  and  14 . However, the two methods both will influence the resistance of the electrodes.  
       SUMMARY OF THE INVENTION  
       [0013]     It is therefore an objective of the present invention to provide a method for manufacturing electrodes of a plasma display panel for preventing the edge curl and increasing the quality of the electrodes.  
         [0014]     According to the present invention, a method for manufacturing electrodes of a plasma display panel includes the following steps. In the first step, a front transparent substrate including a plurality of transparent electrodes disposed on the front transparent substrate is provided. In the second step, a black photosensitive paste film of negative-working type is coated on the transparent electrodes. In the third step, a main photosensitive conductive paste film of negative-working type is coated on the black photosensitive paste film. In the fourth step, an exposure process is performed for exposing the black photosensitive paste film and the main photosensitive conductive paste film to define a plurality of bus electrodes on the corresponding transparent electrodes, wherein a first exposure energy acting on a plurality of main regions of the bus electrodes is greater than a second exposure energy acting on a plurality of edge regions of the bus electrodes. In the fifth step, a development process is performed to develop the exposed black photosensitive paste film and main photosensitive conductive paste film to form the bus electrodes, in which a first thickness of the edge regions of the bus electrodes is less than a second thickness of the main regions of the bus electrodes. In the sixth step, a firing process is performed to fire the developed black photosensitive paste film and main photosensitive conductive paste film.  
         [0015]     It is an advantage of the present invention that the manufactured electrodes are capable of preventing the edge curl and then reducing the breakdown probability of dielectrics near edges of the electrodes.  
         [0016]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  to  FIG. 3  are schematic diagrams for illustrating a method for manufacturing electrodes of a PDP according to the prior art.  
         [0018]      FIG. 4  to  FIG. 6  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a first preferred embodiment of the present invention.  
         [0019]      FIG. 7  is a schematic graph for illustrating exposure energies with corresponding positions.  
         [0020]      FIG. 8  and  FIG. 9  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a second preferred embodiment of the present invention.  
         [0021]      FIG. 10  to  FIG. 12  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a third preferred embodiment of the present invention.  
         [0022]      FIG. 13  and  FIG. 14  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a fourth preferred embodiment of the present invention.  
         [0023]      FIG. 15  to  FIG. 18  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a fifth preferred embodiment of the present invention.  
         [0024]      FIG. 19  and  FIG. 20  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a sixth preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0025]     Please refer to  FIG. 4  to  FIG. 6 .  FIG. 4  to  FIG. 6  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a first preferred embodiment of the present invention. As shown in  FIG. 4 , a front substrate  50 , for example, glass or other transparent boards, is provided. A plurality of transparent electrodes  52  and  54  are formed on the front substrate  50  and a discharge gap  56  is located between the transparent electrodes  52  and  54 . The transparent electrodes  52  and  54  consist of indium tin oxide (ITO).  
         [0026]     A black photosensitive paste film  58  of negative-working type is coated on the transparent electrodes  52  and  54  for increasing the display contrast of a PDP (not shown in  FIG. 4 ) and then a main photosensitive conductive paste film  60  of negative-working type is coated on the black photosensitive paste film  58 .  
         [0027]     Utilizing a photo mask  62 , an exposure process is performed for exposing the black photosensitive paste film  58  and the main photosensitive conductive paste film  60  to define a plurality of bus electrodes (not shown in  FIG. 4 ) on the corresponding transparent electrodes  52  and  54 . The photo mask  62  includes a plurality of opening regions  64  and  66  in corresponding main regions  68  and  70  of the bus electrodes and a plurality of fence regions  72 ,  74 ,  76 , and  78  in corresponding edge regions  80 ,  82 ,  84 , and  86  of the bus electrodes. The fence regions  72 ,  74 ,  76 , and  78  include a plurality of parallel slits  88 ,  90 ,  92 ,  94 ,  96 ,  98 ,  100 , and  102  parallel to edges of the opening regions  64  and  66 . Light  104  such as a collimated ultraviolet (UV) light of the exposure process passes through the opening regions  64  and  66  and the fence regions  72 ,  74 ,  76 , and  78 . Because the fence regions  72 ,  74 ,  76 , and  78  include the parallel slits  88 ,  90 ,  92 ,  94 ,  96 ,  98 ,  100 , and  102 , the fence regions  72 ,  74 ,  76 , and  78  influence the light  104  by an interference effect. Please refer to  FIG. 7 .  FIG. 7  is a schematic graph for illustrating exposure energies with corresponding positions. As shown in  FIG. 7 , a first exposure energy acting on the main regions  68  and  70  of the bus electrodes is greater than a second exposure energy acting on the edge regions  80 ,  82 ,  84 , and  86  of the bus electrodes.  
         [0028]     As shown in  FIG. 5 , after the exposure process, a development process is performed to develop the exposed black photosensitive paste film  58  and main photosensitive conductive paste film  60  to form the bus electrodes  106  and  108 . Since the second exposure energy acting on the edge regions  80 ,  82 ,  84 , and  86  of the bus electrodes  106  and  108  is less than the first exposure energy acting on the main regions  68  and  70  of the bus electrodes  106  and  108 , a first thickness of the edge regions  80 ,  82 ,  84 , and  86  of the bus electrodes  106  and  108  is less than a second thickness of the main regions  68  and  70  of the bus electrodes  106  and  108 .  
         [0029]     As shown in  FIG. 6 , a firing process is performed for firing the developed black photosensitive paste film  58  and main photosensitive conductive paste film  60  to remove a resin component (not shown in  FIG. 6 ) from the black photosensitive paste film  58  and the main photosensitive conductive paste film  60 . Since the first thickness of the edge regions  80 ,  82 ,  84 , and  86  of the bus electrodes  106  and  108  is less than a second thickness of the main regions  68  and  70  of the bus electrodes  106  and  108 , a tensile force occurs while high temperature firing and the edges of the bus electrodes  106  and  108  adhere to the transparent electrodes  52  and  54  well. Therefore, edge curls will not occur.  
         [0030]     Please refer to  FIG. 8  and  FIG. 9 .  FIG. 8  and  FIG. 9  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a second preferred embodiment of the present invention. The difference between the first preferred embodiment and the second preferred embodiment is that a halftone mask is utilized to define bus electrodes.  
         [0031]     As shown in  FIG. 8 , utilizing a halftone mask  120 , an exposure process is performed for exposing a black photosensitive paste film  122  and a main photosensitive conductive paste film  124  on transparent electrodes  126  and  128  disposed on a front substrate  130  to define a plurality of bus electrodes (not shown in  FIG. 8 ) on the corresponding transparent electrodes  126  and  128 . The photo mask  120  includes a plurality of opening regions  132  and  134  in corresponding main regions  136  and  138  of the bus electrodes (not shown in  FIG. 8 ) and a plurality of halftone regions  140 ,  142 ,  144 , and  146  in corresponding edge regions  148 ,  150 ,  152 , and  154  of the bus electrodes. Light  156  such as a collimated ultraviolet (UV) light of the exposure process passes through the opening regions  132  and  134  and the halftone regions  140 ,  142 ,  144 , and  146 . Because the light  156  passing through the halftone regions  140 ,  142 ,  144 , and  146  is reduced, a first exposure energy acting on the main regions  136  and  138  of the bus electrodes is greater than a second exposure energy acting on the edge regions  148 ,  150 ,  152 , and  154  of the bus electrodes.  
         [0032]     As shown in  FIG. 9 , after the exposure process, a development process is performed to develop the exposed black photosensitive paste film  122  and main photosensitive conductive paste film  124  to form bus electrodes  158  and  160 . Since the second exposure energy acting on the edge regions  148 ,  150 ,  152 , and  154  of the bus electrodes  158  and  160  is less than the first exposure energy acting on the main regions  136  and  138  of the bus electrodes  158  and  160 , a first thickness of the edge regions  148 ,  150 ,  152 , and  154  of the bus electrodes  158  and  160  is less than a second thickness of the main regions  136  and  138  of the bus electrodes  158  and  160 . Therefore, in a following firing process, edge curls will not occur.  
         [0033]     Please refer to  FIG. 10  to  FIG. 12 .  FIG. 10  to  FIG. 12  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a third preferred embodiment of the present invention. The difference between the third preferred embodiment and the first preferred embodiment is that transparent electrodes are not formed on a front substrate.  
         [0034]     As shown in  FIG. 10 , a front substrate  200 , for example, glass or other transparent boards, is provided. A black photosensitive paste film  202  of negative-working type is coated on the front substrate  200  for increasing the display contrast of a PDP (not shown in  FIG. 10 ) and then a main photosensitive conductive paste film  204  of negative-working type is coated on the black photosensitive paste film  202 .  
         [0035]     Utilizing a photo mask  206 , an exposure process is performed for exposing the black photosensitive paste film  202  and the main photosensitive conductive paste film  204  to define a plurality of bus electrodes (not shown in  FIG. 10 ) on the front substrate  200 . The photo mask  206  includes a plurality of opening regions  208  and  210  in corresponding main regions  212  and  214  of the bus electrodes and a plurality of fence regions  216 ,  218 ,  220 , and  222  in corresponding edge regions  224 ,  226 ,  228 , and  230  of the bus electrodes. The fence regions  216 ,  218 ,  220 , and  222  include a plurality of parallel slits  232 ,  234 ,  236 ,  238 ,  240 ,  242 ,  244 , and  246  parallel to edges of the opening regions  208  and  210 . Light  247  such as a collimated ultraviolet (UV) light of the exposure process passes through the opening regions  208  and  210  and the fence regions  216 ,  218 ,  220 , and  222 . Because the fence regions  216 ,  218 ,  220 , and  222  include the parallel slits  232 ,  234 ,  236 ,  238 ,  240 ,  242 ,  244 , and  246 , the fence regions  216 ,  218 ,  220 , and  222  influence the light  247  by an interference effect. A first exposure energy acting on the main regions  212  and  214  of the bus electrodes is greater than a second exposure energy acting on the edge regions  224 ,  226 ,  228 , and  230  of the bus electrodes.  
         [0036]     As shown in  FIG. 11 , after the exposure process, a development process is performed to develop the exposed black photosensitive paste film  202  and main photosensitive conductive paste film  204  to form the bus electrodes  248  and  250 . Since the second exposure energy acting on the edge regions  224 ,  226 ,  228 , and  230  of the bus electrodes  248  and  250  is less than the first exposure energy acting on the main regions  212  and  214  of the bus electrodes  248  and  250 , a first thickness of the edge regions  224 ,  226 ,  228 , and  230  of the bus electrodes  248  and  250  is less than a second thickness of the main regions  212  and  214  of the bus electrodes  248  and  250 .  
         [0037]     As shown in  FIG. 12 , a firing process is performed for firing the developed black photosensitive paste film  202  and main photosensitive conductive paste film  204  to remove a resin component (not shown in  FIG. 12 ) from the black photosensitive paste film  202  and the main photosensitive conductive paste film  204 . Since the first thickness of the edge regions  224 ,  226 ,  228 , and  230  of the bus electrodes  248  and  250  is less than a second thickness of the main regions  212  and  214  of the bus electrodes  248  and  250 , a tensile force occurs while high temperature firing and the edges of the bus electrodes  248  and  250  adhere to the front substrate  200  well. Therefore, edge curls will not occur.  
         [0038]     Please refer to  FIG. 13  and  FIG. 14 .  FIG. 13  and  FIG. 14  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a fourth preferred embodiment of the present invention. The difference between the fourth preferred embodiment and the third preferred embodiment is that a halftone mask is utilized to define bus electrodes.  
         [0039]     As shown in  FIG. 13 , utilizing a half tone mask  260 , an exposure process is performed for exposing a black photosensitive paste film  262  and a main photosensitive conductive paste film  264  on a front substrate  266  to define a plurality of bus electrodes (not shown in  FIG. 13 ) on the front substrate  266 . The photo mask  260  includes a plurality of opening regions  268  and  270  in corresponding main regions  272  and  274  of the bus electrodes (not shown in  FIG. 13 ) and a plurality of halftone regions  276 ,  278 ,  280 , and  282  in corresponding edge regions  284 ,  286 ,  288 , and  290  of the bus electrodes. Light  292  such as a collimated ultraviolet (UV) light of the exposure process passes through the opening regions  268  and  270  and the halftone regions  276 ,  278 ,  280 , and  282 . Because the light  292  passing through the halftone regions  276 ,  278 ,  280 , and  282  is reduced, a first exposure energy acting on the main regions  272  and  274  of the bus electrodes is greater than a second exposure energy acting on the edge regions  284 ,  286 ,  288 , and  290  of the bus electrodes.  
         [0040]     As shown in  FIG. 14 , after the exposure process, a development process is performed to develop the exposed black photosensitive paste film  262  and main photosensitive conductive paste film  264  to form bus electrodes  294  and  296 . Since the second exposure energy acting on the edge regions  284 ,  286 ,  288 , and  290  of the bus electrodes  294  and  296  is less than the first exposure energy acting on the main regions  272  and  274  of the bus electrodes  294  and  296 , a first thickness of the edge regions  284 ,  286 ,  288 , and  290  of the bus electrodes  294  and  296  is less than a second thickness of the main regions  272  and  274  of the bus electrodes  294  and  296 . Therefore, in a following firing process, edge curls will not occur.  
         [0041]     Please refer to  FIG. 15  to  FIG. 18 .  FIG. 15  to  FIG. 18  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a fifth preferred embodiment of the present invention. The difference between the fifth preferred embodiment and the first preferred embodiment is that the fifth preferred embodiment illustrates a method for forming address electrodes on a rear substrate.  
         [0042]     As shown in  FIG. 15 , a rear substrate  300 , for example, glass or other transparent boards, is provided. A photosensitive conductive paste film  302  of negative-working type is coated on the rear substrate  300 .  
         [0043]     Utilizing a photo mask  304 , an exposure process is performed for exposing the photosensitive conductive paste film  302  to define a plurality of address electrodes (not shown in  FIG. 15 ) on the rear substrate  300 . The photo mask  304  includes a plurality of opening regions  306 ,  308  and  310  in corresponding main regions  312 ,  314  and  316  of the address electrodes and a plurality of fence regions  318 ,  320 ,  322 ,  324 ,  326  and  328  in corresponding edge regions  330 ,  332 ,  334 ,  336 ,  338  and  340  of the address electrodes. The fence regions  318 ,  320 ,  322 ,  324 ,  326  and  328  include a plurality of parallel slits  342 ,  344 ,  346 ,  348 ,  350 ,  352 ,  354 ,  356 ,  358 ,  360 ,  362  and  364  parallel to edges of the opening regions  306 ,  308  and  310 . Light  366  such as a collimated ultraviolet (UV) light of the exposure process passes through the opening regions  306 ,  308  and  310  and the fence regions  318 ,  320 ,  322 ,  324 ,  326  and  328 . Because the fence regions  318 ,  320 ,  322 ,  324 ,  326  and  328  include the parallel slits  342 ,  344 ,  346 ,  348 ,  350 ,  352 ,  354 ,  356 ,  358 ,  360 ,  362  and  364 , the fence regions  318 ,  320 ,  322 ,  324 ,  326  and  328  influence the light  366  by an interference effect. A first exposure energy acting on the main regions  312 ,  314  and  316  of the address electrodes is greater than a second exposure energy acting on the edge regions  330 ,  332 ,  334 ,  336 ,  338  and  340  of the address electrodes.  
         [0044]     As shown in  FIG. 16 , after the exposure process, a development process is performed to develop the photosensitive conductive paste film  302  to form the address electrodes  368 ,  370  and  372 . Since the second exposure energy acting on the edge regions  330 ,  332 ,  334 ,  336 ,  338  and  340  of the address electrodes  368 ,  370  and  372  is less than the first exposure energy acting on the main regions  312 ,  314  and  316  of the address electrodes  368 ,  370  and  372 , a first thickness of the edge regions  330 ,  332 ,  334 ,  336 ,  338  and  340  of the address electrodes  368 ,  370  and  372  is less than a second thickness of the main regions  312 ,  314  and  316  of the address electrodes  368 ,  370  and  372 .  
         [0045]     As shown in  FIG. 17 , a firing process is performed for firing the developed photosensitive conductive paste film  302  to remove a resin component (not shown in  FIG. 17 ) from the photosensitive conductive paste film  302 . Since the first thickness of the edge regions  330 ,  332 ,  334 ,  336 ,  338  and  340  of the address electrodes  368 ,  370  and  372  is less than a second thickness of the main regions  312 ,  314  and  316  of the address electrodes  368 ,  370  and  372 , a tensile force occurs while high temperature firing and the edges of the address electrodes  368 ,  370  and  372  adhere to the rear substrate  300  well. Therefore, edge curls will not occur.  
         [0046]     As shown in  FIG. 18 , a dielectric layer  374  is formed on the address electrodes  368 ,  370  and  372  and the rear substrate  300 . Then, a plurality of barrier ribs  376 ,  378 ,  380  and  382  are formed on the dielectric layer  374 .  
         [0047]     Please refer to  FIG. 19  and  FIG. 20 .  FIG. 19  and  FIG. 20  are schematic diagrams illustrating a method for manufacturing electrodes of a PDP according to a sixth preferred embodiment of the present invention. The difference between the sixth preferred embodiment and the fifth preferred embodiment is that a halftone mask is utilized to define address electrodes.  
         [0048]     As shown in  FIG. 19 , utilizing a half tone mask  390 , an exposure process is performed for exposing a photosensitive conductive paste film  392  on a rear substrate  394  to define a plurality of address electrodes (not shown in  FIG. 19 ) on the rear substrate  394 . The photo mask  390  includes a plurality of opening regions  396 ,  398  and  400  in corresponding main regions  402 ,  404  and  406  of the address electrodes (not shown in  FIG. 19 ) and a plurality of halftone regions  408 ,  410 ,  412 ,  414 ,  416  and  418  in corresponding edge regions  420 ,  422 ,  424 ,  426 ,  428  and  430  of the address electrodes. Light  432  such as a collimated ultraviolet (UV) light of the exposure process passes through the opening regions  396 ,  398  and  400  and the halftone regions  408 ,  410 ,  412 ,  414 ,  416  and  418 . Because the light  432  passing through the halftone regions  408 ,  410 ,  412 ,  414 ,  416  and  418  is reduced, a first exposure energy acting on the main regions  402 ,  404  and  406  of the address electrodes is greater than a second exposure energy acting on the edge regions  420 ,  422 ,  424 ,  426 ,  428  and  430  of the address electrodes.  
         [0049]     As shown in  FIG. 20 , after the exposure process, a development process is performed to develop the exposed photosensitive conductive paste film  392  to form address electrodes  434 ,  436  and  438 . Since the second exposure energy acting on the edge regions  420 ,  422 ,  424 ,  426 ,  428  and  430  of the address electrodes  434 ,  436  and  438  is less than the first exposure energy acting on the main regions  402 ,  404  and  406  of the address electrodes  434 ,  436  and  438 , a first thickness of the edge regions  420 ,  422 ,  424 ,  426 ,  428  and  430  of the address electrodes  434 ,  436  and  438  is less than a second thickness of the main regions  402 ,  404  and  406  of the address electrodes  434 ,  436  and  438 . Therefore, in a following firing process, edge curls will not occur.  
         [0050]     Compared to the prior art, it is an advantage of the present invention that the manufactured bus and address electrodes are capable of preventing the edge curl and then reducing the breakdown probability of dielectrics near edges of the bus and address electrodes.  
         [0051]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.