Abstract:
A method for cutting a liquid crystal display panel includes forming a first scribe line along attached first and second mother substrates to form a first region having a plurality of first-sized LCD panels and a first edge of the first region and to form a second region having a plurality of second-sized LCD panels and a first edge of the second region, separating the plurality of first-sized LCD panels formed at the first region into individual first-sized LCD panels, and separating the plurality of second-sized LCD panels formed at the second region into individual second-sized LCD panels.

Description:
[0001]    The present invention claims the benefit of Korean Patent Application No. 41288/2003 filed in Korea on Jun. 24, 2003, which is hereby incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a method for cutting a display panel and method for fabricating individual display cells, and particularly, to a method for cutting a liquid crystal display (LCD) panel and method for fabricating individual liquid crystal display cells using the same  
           [0004]    2. Description of the Background Art  
           [0005]    In general, an LCD device includes a matrix array of LCD cells supplied with data signals to control light transmittance of the LCD cells to display images. The LCD device is fabricated by forming a plurality of thin film transistor (TFT) array substrates on a first large-sized mother substrate, which is commonly formed of glass, and a plurality of color filter substrates on a second large-sized mother substrate. Then, the first and second large-sized mother substrates are attached to each other to form a plurality of unit LCD panels. Next, the attached first and second large-sized mother substrates undergo a cutting process to produce a plurality of individual unit LCD panels. The cutting process is commonly performed by forming a groove on a surface of one of the mother substrates using a cutting wheel having a hardness greater than a hardness of the glass mother substrates, and breaking the glass substrate along the groove. A cutting process of a unit liquid crystal display panel will now be described with reference to accompanying drawings.  
           [0006]    [0006]FIG. 1 is a schematic plan view of a unit LCD panel according to the related art. In FIG. 1, a liquid crystal display panel  10  includes an image display part  13  where LCD cells are arranged in a matrix configuration, a gate pad part  14  connected with gate lines  4  of the image display part  13 , and a data pad part  15  connected with data lines  5  of the image display part  13 . As shown in FIG. 1, one long side and one short side of a TFT array substrate  1  protrude from sides of a color filter substrate  2 . Accordingly, the gate pad part  14  is formed at the protruding short side of the TFT array substrate  1 , and the data pad part  15  is formed at the protruding long side of the TFT array substrate  1 .  
           [0007]    The gate pad part  14  supplies scan signals supplied from a gate driving part to the gate lines  4  of the image display part  13 , and the data pad part  15  supplies image information supplied from a data driving part to the data lines  5  of the image display part  13 . The gate lines  4  and the data lines  5  intersect at the image display part  13  of the TFT array substrate  1 , wherein a unit pixel is formed in a region where the gate and data lines  4  and  5  intersect. In addition, each unit pixel includes a TFT to function as a switching element and a pixel electrode connected to the TFT.  
           [0008]    The image display part  13  of the color filter substrate  2  is provided with a color filter that is separated into a plurality of cell areas by a black matrix and a common electrode that correspond to a pixel electrode formed at the TFT array substrate  1 .  
           [0009]    The TFT array substrate  1  and the color filter substrate  2  are attached together by a sealant (not shown) formed at an outer edge of the image display part  13 . In addition, spacers are provided between the attached TFT array substrate  1  and color filter substrate  2  to maintain a uniform cell-gap therebetween. Accordingly, a liquid crystal layer (not shown) is formed within the uniform cell-gap between the TFT array substrate  1  and the color filter substrate  2 .  
           [0010]    [0010]FIG. 2 is a cross sectional view of a plurality of LCD panels according to the related art. In FIG. 2, since each of the unit LCD panels is formed such that one side of the TFT array substrate  2  is formed to protrude from the color filter substrate  2 , each of the color filter substrates  2  formed on a second mother substrate  30  is mutually isolated from one another by a dummy region  31 . The dummy region  31  corresponds to an area where each of the TFT array substrates  1  protrude from the color filter substrates  2 .  
           [0011]    In addition, each of the unit LCD panels is positioned to maximize useable areas of the first and second mother substrates  20  and  30 . For example, each of the unit LCD panels are formed isolated from one another by a dummy region  32 , and in order to accommodate for a process margin a dummy region  21  is formed at an edge of the first and second mother substrates  20  and  30 .  
           [0012]    After the first and second mother substrates  20  and  30  are attached to each other, the attached first and second mother substrates  20  and  30  are cut into a plurality of individual LCD panels. Accordingly, the dummy region  32  are removed, and the dummy region  31  formed at the area where the color filter substrates  2  of the second mother substrate  30  are isolated.  
           [0013]    [0013]FIG. 3 is a schematic plan view of a plurality of LCD panels according to the related art, and FIG. 4 is a schematic plan view of a plurality of LCD panels according to the related art. In FIG. 4, when bigger-sized LCD panels  120  are fabricated on a mother substrate  100 , as compared to the LCD panels  110  I FIG. 3, only four LCD panels  120  can be formed on a portion of the mother substrate  100 . Accordingly, a large amount of the mother substrate  100  is discarded, thereby creating a significant amount of waste, increasing production costs, and reducing manufacturing efficiency.  
         SUMMARY OF THE INVENTION  
         [0014]    Accordingly, the present invention is directed to a method for cutting an LCD panel and method for fabricating individual LCD cells using the same that substantially obviates one of more of the problems due to limitations and disadvantages of the related art.  
           [0015]    An object of the present invention is to provide a method for cutting an LCD panel having a simplified alignment process.  
           [0016]    Another object of the present invention is provide a method for fabricating individual LCD cells having a simplified process.  
           [0017]    Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
           [0018]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method for cutting a liquid crystal display panel includes forming a first scribe line along attached first and second mother substrates to form a first region having a plurality of first-sized LCD panels and a first edge of the first region and to form a second region having a plurality of second-sized LCD panels and a first edge of the second region, separating the plurality of first-sized LCD panels formed at the first region into individual first-sized LCD panels, and separating the plurality of second-sized LCD panels formed at the second region into individual second-sized LCD panels.  
           [0019]    In another aspect, a method for fabricating individual liquid crystal display cells includes attaching first and second mother substrates together, forming a first scribe line within a first scribe line region along the attached first and second mother substrates to form a first panel having a plurality of first-sized LCD panels and a first panel edge of the first panel, and to form a second panel having a plurality of second-sized LCD panels and a first panel edge of the second panel, removing an end portion of the first panel to form a second panel edge of the first panel opposite to the first panel edge of the first panel, removing an end portion of the second panel to form a second panel edge of the second panel opposite to the first panel edge of the second panel, separating the plurality of first-sized LCD panels formed at the first region into individual first-sized LCD cells, and separating the plurality of second-sized LCD panels formed at the second region into individual second-sized LCD cells.  
           [0020]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a unit of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:  
         [0022]    [0022]FIG. 1 is a schematic plan view of a unit LCD panel according to the related art;  
         [0023]    [0023]FIG. 2 is a cross sectional view of a plurality of LCD panels according to the related art;  
         [0024]    [0024]FIG. 3 is a schematic plan view of a plurality of LCD panels according to the related art;  
         [0025]    [0025]FIG. 4 is a schematic plan view of a plurality of LCD panels according to the related art;  
         [0026]    [0026]FIGS. 5A and 5B are schematic plan views of exemplary mother substrates according to the present invention;  
         [0027]    [0027]FIGS. 6A and 6B are schematic plan views of an exemplary cutting process of LCD panels according to the present invention; and  
         [0028]    [0028]FIGS. 7A to  7 C are schematic plan views of another exemplary cutting process of LCD panels according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0030]    [0030]FIGS. 5A and 5B are schematic plan views of exemplary mother substrates according to the present invention. In FIGS. 5A and 5B, first and second mother substrates  210  and  220  may include a first region  211  fabricated to include a plurality of first LCD panels  201  each having a first size and isolated at certain intervals therein, and a second region  212  fabricated to include a plurality of second LCD panels  202  each having a second size and isolated at certain intervals therein. Accordingly, maximum efficiency may be obtained by making use of all useable space on the first and second mother substrates  210  and  220 .  
         [0031]    In FIGS. 5A and 5B, a plurality of alignment keys  204  may be formed at corner regions of each of the LCD panels  201  and each of the LCD panels  202 . In addition, a plurality of alignment pins  203  may be provided by a cutting apparatus, thereby aligning the attached first and second mother substrates  210  and  220  with the cutting apparatus.  
         [0032]    Although not specifically shown, each of the LCD panels  201  and  202  may be attached to each other along one short side and one long side of a TFT array substrate that may protrude from a color filter substrate. In addition, a gate pad part may be formed at the protruding one short side of the TFT array substrate, and a data pad part may be formed at the protruding one long side of the TFT array substrate.  
         [0033]    In FIG. 5B, a first region  211  where first-sized LCD panels  201  are formed and a second region  212  where second-sized LCD panels  202  are formed are aligned with a cutting apparatus, as detailed above. Then, a first scribing line  221  may be formed between the first region  211  and the second region  212  to separate the first region and the second region  212 . Accordingly, a distance (D1) between the first-sized LCD panels  201  and the first scribing line  221  and a distance (D2) between the first-sized LCD panels  201  and an end portion of the first region  211  may be different from each other. In addition, a distance (D3) between the second-sized LCD panels  202  and the first scribing line  221  and a distance (D4) between the second-sized LCD panels  202  and an end portion of the second region  212  may be different from each other.  
         [0034]    An exemplary method for cutting an LCD panel to produce a plurality of individual LCD panels fabricated on the attached mother substrates of FIGS. 5A and 5B may include a first alignment of the first and second mother substrates  210  and  220  with a cutting apparatus using the alignment pins  203 , and a second alignment using the alignment keys  204 . For example, the first alignment may include manual alignment of the attached first and second substrates  210  and  220  to contact the alignment pins  203  of the cutting apparatus. Then, the second alignment may include an imaging system for detecting coordinates of the alignment keys  204  to provide reference coordinates.  
         [0035]    [0035]FIGS. 6A and 6B are schematic plan views of an exemplary cutting process of LCD panels according to the present invention. In FIG. 6A, the separated second region  212  may be aligned with the cutting apparatus using the alignment pins  203  and the alignment keys  204 , and second scribing lines  222 A- 222 J may be formed along long sides and short sides of the second-sized LCD panels. For example, a first alignment may use the alignment pins  203  and a second alignment may use the alignment keys  204 , wherein an imaging system may detect coordinates of the alignment keys  204 , and the second region  212  may be positioned at reference coordinates. For example, an imaging device may move to predetermined reference coordinates to detect coordinates of the alignment key  204 . Then, the detected coordinates of the alignment key  204  may be compared with the reference coordinates, wherein the second region  212  may be aligned with the cutting apparatus so that the coordinates of the alignment key  204  may correspond to the reference coordinates.  
         [0036]    In FIG. 6B, the second region  212  may be overturned and aligned with the cutting apparatus, as detailed above. Then, by applying force to the surface of the second region  212 , a split may be formed along the second scribing lines  222 A- 222 J, and third scribing lines  223 A- 223 J may be formed along long sides and short sides of the second-sized LCD panels  202  using alignment process detailed above.  
         [0037]    Then, the second region  212  is again overturned and aligned with the cutting apparatus. Next, a split is generated along the third scribing lines  223 A- 223 J by supplying a force to a surface of the second region  212 . Accordingly, the second-sized LCD panels  202  are individually separated from the second region  212  by the splits generated along the second scribing lines  222 A- 222 J and third scribing lines  223 A- 223 J.  
         [0038]    However, since the distance (D3) between the second-sized LCD panels  202  and the first scribing line  221  and the distance (D4) between the second-sized LCD panels  202  and an end portion of the second region  212  are different from each other, each time the second region  212  is overturned, positions of the alignment keys  204  formed at the corners of the second-sized LCD panels  202  are changed. Accordingly, when the imaging system moves to predetermined reference coordinates, coordinates of the alignment keys  204  formed at the corners of the second-sized LCD panel  202  may not be detected. Thus, reference coordinates of the imaging system may need to be corrected, thereby reducing production efficiency.  
         [0039]    [0039]FIGS. 7A to  7 C are schematic plan views of another exemplary cutting process of LCD panels according to the present invention. In FIG. 7A, a first region  311  where first-sized LCD panels  301  are formed and a second region  312  where second-sized LCD panels  302  are formed may be loaded onto a cutting apparatus and aligned therewith. Then, a first scribing line  321  may be formed between the first region  311  and the second region  312  to separate the first region  311  and the second region  312 . For example, the first scribing line  321  may be formed so that a distance (D11) between the first-sized LCD panels  301  and the first scribing line  321  and a distance (D12) between the first-sized LCD panels  301  and an end portion of the first region  311  may be equal. Alternatively, the first scribing line  321  may be formed so that a distance (D13) between the second-sized LCD panels  302  and the first scribing line  321  and a distance (D14) between the second-sized LCD panels  302  and an end portion of the second region  321  may be equal.  
         [0040]    In order to form the first scribing line  321 , the first-sized LCD panels  301  and the second-sized LCD panels  302  may be formed on a large-sized mother substrate to include isolation intervals between the first-sized LCD panels  301  and the second-sized LCD panels  302 , a distance from an edge of the mother substrate to the first-sized LCD panels  301 , and a distance from an edge of the mother substrate to the second-sized LCD panels  302 .  
         [0041]    A process for cutting out an end portion of the first region  311  may be added after the first scribing line  321  is formed so that a distance (D11) between the first-sized LCD panels  301  and the first scribing line  321 , and a distance (D12) between the first-sized LCD panels  301  and an end portion of the first region  311  may be equal. Similary, a process for cutting an end portion of the second region  312  may be added so that a distance (D13) between the second-sized LCD panels  302  and the first scribing line  321 , and a distance (D14) between the second-sized LCD panels  302  and an end portion of the second region  312  may be equal.  
         [0042]    In FIG. 7B, the separated second region  312  may be loaded onto the cutting apparatus and aligned therewith. Then, second scribing lines  322 A- 322 J may be formed along short sides and long sides of the second-sized LCD panels  302 .  
         [0043]    In FIG. 7C, the second region  312  may be overturned and aligned with the cutting apparatus. As described above, the first scribing line  321  may be formed so that a distance (D13) between the second-sized LCD panels  302  and the first scribing line  321 , and a distance (D14) between the second-sized LCD panels  302  and an end portion of the second region  312  may be equal. Accordingly, when the second region  312  is overturned, positions of the alignment keys  304  formed at corners of the second-sized LCD panels  302  may not have changed. Thus, when the imaging system moves to predetermined reference coordinates, coordinates of the alignment keys  304  formed at the corners of the second-sized LCD panel  302  may be detected. Accordingly, the second region  312  may be aligned with the cutting apparatus without correction of the reference coordinates of the imaging system, thereby reducing time for performing the alignment and improving productivity.  
         [0044]    Then, by applying force to the surface of the second region  312 , a split may be generated along the second scribing lines  322 A- 322 J, and third scribing lines  323 A- 323 J may be formed along long sides and short sides of the second-sized LCD panels  302 .  
         [0045]    Then, the second region  312  may be again overturned and aligned with the cutting apparatus. As previously described, since the distance (D13) and the distance (D14) may be equal, positions of the alignment keys  304  formed at corners of the second-sized LCD panels  302  may not have changed. Next, by applying force to the surface of the second region  312 , a split may be generated along the third scribing lines  323 A- 323 J. Accordingly, the second-sized LCD panels  302  may be individually separated from the second region  312  by the spilts generated along the second scribing lines  322 A- 322 J and the third scribing lines  323 A- 323 J.  
         [0046]    In addition, a method for cutting an LCD panel may also include individually separating the LCD panels  301  of the first region  311  using the process for individually separating the LCD panels  302  of the second region  312 . Moreover, according to the present invention, the mother substrate may include additional regions each having different sized LCD panels, wherein the method for cutting an LCD panel may be employed.  
         [0047]    It will be apparent to those skilled in the art that various modifications and variations can be made in the method for cutting an LCD panel and an LCD panel fabricated using the same of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations provided they come within the scope of the appended claims and their equivalents.