Abstract:
A system for manufacturing a flat panel display is provided including: a first mask loading/unloading part for loading at least one mask; a main mask-stage for disposing the mask; a first mask-transferer for transferring the mask from the first mask loading/unloading part onto the main mask-stage; a second mask loading/unloading part positioned apart from the first mask loading/unloading part by a predetermined distance; and a second mask-transferer for transferring the mask from the second mask loading/unloading part onto the main mask-stage. This system may reduce the time required for changing masks used to manufacture flat panel displays.

Description:
BACKGROUND  
       [0001]     (a) Field of the Invention  
         [0002]     The present invention relates to a system and method for manufacturing a flat panel display, and in particular, to an exposure system and method for forming a semiconductor layer on a substrate.  
         [0003]     (b) Description of Related Art  
         [0004]     Flat panel displays, such as liquid crystal displays (LCDs) and organic light emitting diode (OLED) displays, are widely used. A liquid crystal display includes a pair of panels, which include field generating electrodes formed thereon, and a liquid crystal layer disposed therebetween. Liquid crystal molecules of the liquid crystal layer are rearranged by voltages supplied to the electrodes. Transmittance of light passing through the liquid crystal layer is controlled by the rearrangement of the liquid crystal layer.  
         [0005]     Such a panel is manufactured by sequentially processing the substrate with, for example, a thin film deposition process, a cleaning process, a resist coating process, an exposure process, and an etching process.  
         [0006]     An exposure system for performing the exposure process includes a mask, a mask-loader for loading the mask, a mask stage, a mask-transferer for transferring the mask from the mask-loader onto the mask stage, and a substrate transferee. Only one mask-loader, one mask stage, and one mask-transferer are provided in the exposure system.  
         [0007]     In the event that the mask is contaminated or a model is changed, the mask may need to be changed.  
         [0008]     Conventional exposure systems may experience a variety of problems. For example, since only one mask-loader, one mask stage, and one mask-transferer are provided in the exposure system, an excessive amount of time may be consumed in changing the mask, when a change of mask is required. In particular, when the mask is changed, a new mask is transferred from the mask-loader to the mask stage, only after the original mask is completely transferred from the mask stage to the mask-loader by the mask-transferer. Accordingly, an excessive amount of time may be consumed by the change of mask.  
         [0009]     Consequently, during manufacture of the liquid crystal display, manufacturing time may be wasted. For example, 5 to 10 minutes may be consumed by a cycle for merely changing the mask. As a result, productivity may deteriorate.  
       SUMMARY  
       [0010]     A method and apparatus for manufacturing a flat panel display which may resolve the above-mentioned problems and significantly decrease the mask-change time are provided.  
         [0011]     An exemplary system for manufacturing a flat panel display according to an embodiment of the present invention includes: a first mask loading/unloading part for loading or unloading at least one mask; a main mask-stage for receiving the mask; a first mask-transferer for transferring the mask from the first mask loading/unloading part onto the main mask-stage; a second mask loading/unloading part positioned apart from the first mask loading/unloading part by a predetermined distance; and a second mask-transferer for transferring the mask from the second mask loading/unloading part onto the main mask-stage.  
         [0012]     In a further embodiment according to the present invention, the system further includes: a first assistant mask-stage positioned between the main mask-stage and the first mask loading/unloading part; and a second assistant mask-stage positioned between the main mask-stage and the second mask loading/unloading part.  
         [0013]     In another further embodiment according to the present invention, the system further includes: a shuttle or a Linear Motion (LM) guider respectively positioned between the main mask-stage and the first assistant mask-stage, and between the main mask-stage and the second assistant mask-stage.  
         [0014]     In another further embodiment according to the present invention, the system further includes: a substrate fixer positioned below the main mask-stage and apart therefrom by a predetermined distance; a plurality of substrate loading/unloading parts for loading or unloading the substrate; and a substrate-transferer for transferring a substrate from a selected substrate loading/unloading part of the substrate loading/unloading parts onto the substrate fixer or transferring the substrate from the substrate fixer onto the selected substrate loading/unloading part.  
         [0015]     In another further embodiment according to the present invention, the system further includes: first and second substrate fixers respectively positioned below the first and second assistant mask-stages and apart therefrom by a predetermined distance; first and second substrate loading/unloading parts for loading or unloading the substrate; and first and second substrate-transferers for respectively transferring a substrate from the first and the second substrate loading/unloading parts onto the first and the second substrate fixers or respectively transferring the substrate from the first and the second substrate fixers onto the first and the second substrate loading/unloading parts.  
         [0016]     In another further embodiment according to the present invention, the first and second substrate fixers move horizontally.  
         [0017]     An exemplary method for manufacturing a flat panel display according to an embodiment of the present invention includes; transferring a first mask from a first mask loading/unloading part onto a main mask-stage by a first mask-transferer; transferring a second mask from a second mask loading/unloading part onto a second assistant mask-stage by a second mask-transferer; performing an exposure process for a predetermined time by the first mask on the main mask-stage; transferring the first mask from the main mask-stage onto the first assistant mask-stage, and transferring a second mask from the second assistant mask-stage onto the main mask-stage, after completing the exposure process for the predetermined time; and performing an exposure process using the second mask on the main mask-stage for a predetermined time.  
         [0018]     In a further embodiment according to the present invention, the first mask and second masks have a same pattern.  
         [0019]     In another further embodiment according to the present invention, the method further includes: transferring the first mask from the first assistant mask-stage onto the first mask loading/unloading part by the first mask-transferer; transferring a third mask from the first mask loading/unloading part onto the first assistant mask-stage by the first mask-transferer; transferring the second mask from the main mask-stage onto the second assistant mask-stage, and transferring the third mask from the first assistant mask-stage onto the main mask-stage, after completing the exposure process for the predetermined time by the second mask; and performing an exposure process using the third mask on the main mask-stage for a predetermined time.  
         [0020]     In another further embodiment according to the present invention, the exposure process includes: transferring a substrate from a selected substrate loading/unloading part of the substrate loading/unloading parts onto a substrate fixer by a substrate-transferer; exposing the substrate by the first mask of the main mask-stage; and transferring the exposed substrate from the substrate fixer onto the selected substrate loading/unloading part.  
         [0021]     In another further embodiment according to the present invention, the exposure process includes: transferring a substrate from a first substrate loading/unloading part onto a first substrate fixer, positioned to a lower side of the fist assistant mask-stage, by a substrate-transferer; moving the first substrate fixer such that the substrate is positioned to a lower side of the main mask-stage; exposing the substrate by the first mask of the main mask-stage; and transferring the exposed substrate from the first substrate fixer onto the first substrate loading/unloading part.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The present invention will become more apparent by describing preferred embodiments thereof in detail with reference to the accompanying drawings, in which:  
         [0023]     FIGS.  1  to  4  are top plan views of an exposure system according to an embodiment of the present invention, and show sequential operations in which a mask and a substrate are transferred; and  
         [0024]     FIGS.  5  to  8  are top plan views of an exposure system according to another embodiment of the present invention, and show sequential operations in which a mask and a substrate are transferred. 
     
    
     DETAILED DESCRIPTION  
       [0025]     The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the inventions are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.  
         [0026]     A system for manufacturing a flat panel display according to an embodiment of the present invention will hereinafter be described in detail with reference to FIGS.  1  to  4 .  
         [0027]     FIGS.  1  to  4  are top plan views of an exposure system according to an embodiment of the present invention, and show sequential operations in which a mask and a substrate are transferred.  
         [0028]     As shown in  FIGS. 1 and 2 , an exposure system according to an embodiment of the present invention includes a first mask loading/unloading part  110 , a first mask-transferer  111 , a first assistant mask-stage  131 , a main mask-stage  132 , a second assistant mask-stage  133 , a second mask-transferer  121 , and a second mask loading/unloading part  120 . Such devices  110 ,  111 ,  131 ,  132 ,  133 ,  121 , and  120  for a mask are arranged in a generally “U”-shaped pattern.  
         [0029]     The exposure system according to an embodiment of the present invention further includes a substrate fixer  213 , a substrate-transferer  211 , a first substrate loading/unloading part  212 , and a second substrate loading/unloading part  210 . Such devices for a substrate are positioned apart from the above-mentioned mask-handling devices by a predetermined distance, and are positioned to a lower side of the mask-handling devices.  
         [0030]     The first and second mask loading/unloading parts  110  and  120  are respectively loaded with at least one mask, and the first mask loading/unloading part  110  is positioned apart from the second mask loading/unloading part  120  by a predetermined distance.  
         [0031]     The first mask-transferer  111  transfers a first mask  10  from the first mask loading/unloading part  110  onto the first assistant mask-stage  131  (or directly onto the main mask-stage  132  if a mask is not already present).  
         [0032]     The second mask-transferer  121  transfers a second mask  20  from the second mask loading/unloading part  120  onto the second assistant mask-stage  133  (or the main mask-stage  132 ).  
         [0033]     It is preferable that the first and second masks  10  and  20  have the same pattern as each other. In other embodiments, the first and second masks may have different patterns.  
         [0034]     The first and the second mask-transferers  111  and  121  may comprise robot arms which can move and rotate the mask vertically and/or horizontally.  
         [0035]     As mentioned above, since multiple mask-loaders and mask-transferers are provided, the unloading of the current mask and the loading of a replacement mask can be performed in parallel. Thus, a mask-change time (i.e., time consumed for changing a mask) can be decreased.  
         [0036]     The mask  10  (or  20 ) is disposed on an upper surface of the main mask-stage  132 . A substrate  1  (shown in  FIG. 3 ) is positioned in correspondence with a lower side of the main mask-stage  132 , and is separated from the main mask-stage  132  by a predetermined distance.  
         [0037]     The first and second assistant mask-stages  131  and  133  are respectively positioned at left and right sides with respect to the main mask-stage  132 . That is, the first assistant mask-stage  131  is positioned between the main mask-stage  132  and the first mask loading/unloading part  110 , and the second assistant mask-stage  133  is positioned between the main mask-stage  132  and the second mask loading/unloading part  120 . As mentioned above, the mask (refer to a second mask  20  in  FIG. 1  or a third mask  30  in  FIG. 2 ) is always disposed on either of the first or the second assistant mask-stages  131  or  133 , and accordingly the masks can always be available for a rapid exchange with the mask currently being used. Consequently, when a mask is changed, the ready mask can be promptly moved to the main mask-stage  132 , and therefore the mask-change time can be significantly decreased.  
         [0038]     The exposure system according to an embodiment of the present invention further includes a first shuttle [or linear mortion (LM) guider]  35  positioned between the main mask-stage  132  and the first assistant mask-stage  131 , and a second shuttle (or LM guider)  36  positioned between the main mask-stage  132  and the second assistant mask-stage  133 .  
         [0039]     The substrate fixer  213  is positioned on a lower side of the main mask-stage  132  in correspondence therewith, and supports/fixes the substrate  1  during an exposure of the substrate  1 .  
         [0040]     The first and the second substrate loading/unloading parts  212  and  210  load a plurality of substrates, and may align a substrate  1 .  
         [0041]     As shown in  FIGS. 3 and 4 , the substrate-transferer  211  transfers the substrate  1  from the first substrate loading/unloading part  212  onto the substrate fixer  213 , and an exposure process is performed. At the same time, a substrate  2  is loaded onto the second substrate loading/unloading part  210 .  
         [0042]     The substrate-transferer  211  transfers the substrate  1  repeatedly performed the exposure process from the substrate fixer  213  onto the first substrate loading/unloading part  212 . The substrate-transferer  211  transfers the substrate  2  from the second substrate loading/unloading part  210  onto the substrate fixer  213 , and an exposure process is repeatedly performed.  
         [0043]     A method for manufacturing a flat panel display according to an embodiment of the present invention will hereinafter be described in detail with reference to FIGS.  1  to  4 .  
         [0044]     First, as shown in  FIG. 1 , the first mask  10  is transferred from the first mask loading/unloading part  110  onto the main mask-stage  132  by the first mask-transferer  111 .  
         [0045]     The second mask  20  is transferred from the second mask loading/unloading part  120  onto the second assistant mask-stage  133  by the second mask-transferer  121 .  
         [0046]     Second, an exposure process is repeatedly performed using the first mask  10  on the main mask-stage  132 .  
         [0047]     The exposure process using the first mask  10  will hereinafter be described in more detail.  
         [0048]     First, as shown in  FIG. 3 , the substrate  1  is transferred from the first substrate loading/unloading part  212  onto the substrate fixer  213  by the substrate-transferer  211 . After the substrate  1  is aligned in correspondence with the first mask  10  by the substrate fixer  213 , the substrate  1  is then fixed by the substrate fixer  213 . At the same time, a new substrate  2  is loaded onto the second substrate loading/unloading part  210 .  
         [0049]     Second, the substrate  1  is exposed by the first mask  10  on the main mask-stage  132 . Thereafter, the exposed substrate  1  is transferred from the substrate fixer  213  onto the first substrate loading/unloading part  212  by the substrate-transferer  211 .  
         [0050]     As shown in  FIG. 4 , the new substrate  2  is transferred from the second substrate loading/unloading part  210  onto the substrate fixer  213  by the substrate-transferer  211 .  
         [0051]     The above-described exposure process is repeatedly performed. During the exposure process, the first mask  10  may be used to expose about 100 to 1000 substrates. Thereafter, the first mask  10  may be changed as follows.  
         [0052]     As shown in  FIG. 1 , the first mask  10  is transferred from the main stage  132  onto the first mask loading/unloading part  110  via the first assistant mask-stage  131  using the first shuttle  35  and the substrate-transferer  211 .  
         [0053]     Thereafter, as shown in  FIG. 2 , the second mask  20 , disposed on the second assistant mask-stage  133 , is transferred onto the main mask-stage  132 . At this time, the shuttle (or LM guider)  36  positioned between the main mask-stage  132  and the second assistant mask-stage  133  is used for facilitating movement of the second mask onto the main mask-stage  132 . Thereafter, the third mask  30  is transferred onto the first assistant mask-stage  131 .  
         [0054]     Thereafter, the above-mentioned exposure process is repeatedly performed by using second mask  20  on the main mask-stage  132 .  
         [0055]     As mentioned above, a mask may be changed while the exposure process is continuously performed.  
         [0056]     Furthermore, according to the conventional scheme, when a mask is changed, the current mask is first completely transferred from the mask stage to the mask loading/unloading part by the mask-transferer, and then a new mask is transferred from the mask loading/unloading part to the mask stage. Accordingly, the mask-change time can be excessively long.  
         [0057]     However, according to an embodiment of the present invention, multiple mask loading/unloading parts, mask-transferers, and assistant mask-stages are provided. Accordingly, as mentioned above, the mask-change time can be significantly decreased.  
         [0058]     A system for manufacturing a flat panel display according to a second embodiment of the present invention will hereinafter be described in detail with reference to FIGS.  5  to  8 .  
         [0059]     FIGS.  5  to  8  are top plan views of an exposure system according to a second embodiment of the present invention, and show sequential operations in which a mask and a substrate are transferred. In the description, components identical to the aforementioned embodiment will be given the same reference symbols.  
         [0060]     As shown in  FIGS. 5 and 6 , an exposure system according to a second embodiment of the present invention includes a first mask loading/unloading part  110 , a first mask-transferer  111 , a first assistant mask-stage  131 , a main mask-stage  132 , a second assistant mask-stage  133 , a second mask-transferer  121 , and a second mask loading/unloading part  120 . Such devices  110 ,  111 ,  131 ,  132 ,  133 ,  121 , and  120  for a mask are arranged in a generally “U”-shaped pattern.  
         [0061]     The exposure system according to the second embodiment of the present invention further includes first and second substrate fixers  213   a  and  213   b , first, second, and third substrate-transferers  211   a ,  211   b , and  211   c , a substrate aligning unit  220 , a first substrate loading/unloading part  210   a , and a second substrate loading/unloading part  210   b . Such devices for handling the substrates are disposed apart from the above-mentioned mask-handling devices by a predetermined distance.  
         [0062]     The first and second mask loading/unloading parts  110  and  120  are respectively loaded with a plurality of masks, and the first mask loading/unloading part  110  is positioned apart from the second mask loading/unloading part  120  by a predetermined distance.  
         [0063]     The first mask-transferer  111  is configured to transfer a first mask  10  between the first mask loading/unloading part  110  and the first assistant mask-stage  131  (or directly onto the main mask-stage  132  if a mask is not already present thereupon).  
         [0064]     The second mask-transferer  121  is configured to transfer a second mask  20  between the second mask loading/unloading part  120  and the second assistant mask-stage  133  (or directly onto the main mask-stage  132 ).  
         [0065]     As mentioned above, since multiple mask-loaders and mask-transferers are provided, the time consumed for changing masks can be decreased.  
         [0066]     The mask  10  (or  20 ) is disposed on an upper surface of the main mask-stage  132 . As shown in  FIG. 8 , a substrate  1  is positioned to be aligned with a lower side of the main mask-stage  132 , and is separated from the main mask-stage  132  by a predetermined distance.  
         [0067]     In the illustrated embodiment, the first and second assistant mask-stages  131  and  133  are respectively positioned at left and right sides with respect to the main mask-stage  132 . That is, the first assistant mask-stage  131  is positioned between the main mask-stage  132  and the first mask loading/unloading part  110 , and the second assistant mask-stage  133  is positioned between the main mask-stage  132  and the second mask loading/unloading part  120 . As mentioned above, the mask (refer to a second mask  20  in  FIG. 5  or a third mask  30  in  FIG. 6 ) is always disposed on either of the first and the second assistant mask-stages  131  or  133 , and accordingly the masks can always be available for a rapid exchange with the mask currently being used. Consequently, when a mask is changed, the ready mask can be promptly moved to the main mask-stage  132 , and therefore the mask-change time can be significantly decreased.  
         [0068]     The exposure system according to an embodiment of the present invention further includes a first shuttle [or Linear Motion (LM) guider]  35  positioned between the main mask-stage  132  and the first assistant mask-stage  131 , and a second shuttle (or LM guider)  36  positioned between the main mask-stage  132  and the second assistant mask-stage  133 .  
         [0069]     The first and second substrate fixers  213   a  and  213   b  are respectively positioned adjacent to a lower side of the first and second assistant mask-stages  131  and  133 , in correspondence therewith. Before an exposure process begins, either the first substrate fixer  213   a  or the second substrate fixer  213   b  is moved to a position corresponding with the main mask-stage  132 .  
         [0070]     The first substrate loading/unloading part  210   a  loads a plurality of substrates  1 , and the substrate aligning unit  220  is surrounded by the first, second, and third substrate-transferers  211   b ,  211   c , and  211   a . The substrate aligning unit  220  aligns a substrate  1 , before the substrate  1  is transferred onto the first or second substrate fixers  213   a  and  213   b.    
         [0071]     As shown in  FIGS. 7 and 8 , the first substrate-transferer  211   a  transfers a substrate  1  from the first substrate loading/unloading part  210   b  onto the substrate aligning unit  220 . The second substrate-transferer  211   b  transfers the substrate  1  from the substrate aligning unit  220  onto the first substrate fixer  213   a.    
         [0072]     In the embodiment illustrated in  FIGS. 5-8 , multiple substrate fixers and substrate-transferers are provided, and the plurality of substrate fixers can be moved to a position corresponding with the main mask-stage  132 .  
         [0073]     A method for manufacturing a flat panel display according to an embodiment of the present invention will hereinafter be described in detail with reference to FIGS.  5  to  8 .  
         [0074]     First, as shown in  FIG. 5 , the first mask  10  is transferred from the first mask loading/unloading part  110  onto the main mask-stage  132  via the first assistant mask-stage  131  by the first mask-transferer  111  and the firs shuttle  35 .  
         [0075]     The second mask  20  is transferred from the second mask loading/unloading part  120  onto the second assistant mask-stage  133  by the second mask-transferer  121 .  
         [0076]     Second, an exposure process is repeatedly performed using the first mask  10  on the main mask-stage  132 , while the second mask  20  is kept readily available on the second assistant mask-stage  133 . During the exposure process, the first mask  10  may be used to expose about 100 to 1000 substrates. Thereafter, the first mask  10  may be changed as follows.  
         [0077]     As shown in  FIG. 5 , the first mask  10  is transferred from the main stage  132  onto the first assistant mask-stage  131  using the first shuttle  35 .  
         [0078]     Thereafter, as shown in  FIG. 6 , the second mask  20 , disposed on the second assistant mask-stage  133 , is transferred onto the main mask-stage  132 . The shuttle (or LM guider)  36  positioned between the main mask-stage  132  and the second assistant mask-stage  133  is used to transfer the second mask onto the main mask-stage  132 .  
         [0079]     Thereafter, the exposure process is repeatedly performed by using second mask  20  on the main mask-stage  132 .  
         [0080]     The exposure process will hereinafter be described in detail.  
         [0081]     First, as shown in  FIG. 7 , a substrate  1  is transferred from the first substrate loading/unloading part  210   a  onto the substrate aligning unit  220  by the first substrate-transferer  211   a . The substrate  1  is aligned by the substrate aligning unit  220 , and is again transferred by the second substrate-transferer  211   b  from the substrate aligning unit  220  onto a first substrate fixer  213   a.    
         [0082]     Next, as shown in  FIG. 8 , the first substrate fixer  213   a  is moved such that the substrate  1  is positioned to the lower side of the main mask-stage  132 .  
         [0083]     After the substrate  1  is correctly aligned with the mask  20  on the main mask-stage  132 , the substrate  1  is exposed by the second mask  20 .  
         [0084]     At this time, a new substrate  2  is transferred from the second substrate loading/unloading part  210   b  onto the substrate aligning unit  220  by the first substrate-transferer  211   a . The substrate  1  is aligned by the substrate aligning unit  220 , and is again transferred by the third substrate-transferer  211   c  from the substrate aligning unit  220  onto a second substrate fixer  213   b.    
         [0085]     Thereafter, as shown in  FIG. 7 , the exposed substrate is transferred from the first substrate fixer  213   b  onto the substrate aligning unit  220  by the second substrate-transferer  211   b , and the aligned substrate is transferred from the substrate aligning unit  220  onto the first substrate loading/unloading part  201   a  by the first substrate-transferer  211   a.    
         [0086]     Such an exposure process may be repeatedly performed using the second mask  20 .  
         [0087]     Furthermore, according to the conventional scheme, when a mask is changed, the mask is first completely transferred from the mask stage to the mask loading/unloading part by the mask-transferer, and then a new mask is transferred from the mask loading/unloading part to the mask stage. Accordingly, the mask-change time is excessively consumed.  
         [0088]     However, according to an embodiment of the present invention, multiple mask loading/unloading parts, mask-transferers, and the assistant mask-stages are provided. Accordingly, as mentioned above, the mask-change time can be significantly decreased.  
         [0089]     As has been explained, systems and methods for manufacturing a flat panel display according to embodiments of the present invention may provide one or more of the following advantages.  
         [0090]     According to the present invention, since a plurality of mask loading/unloading parts are provided, the time consumed for a mask-change can be decreased.  
         [0091]     According to the present invention, since replacement masks are always available for a change on a plurality of assistant mask-stages, masks can be rapidly changed.  
         [0092]     According to the present invention, since a shuttle (or LM guider) is provided, a mask can be easily moved from an assistant mask-stage onto the main mask-stage.  
         [0093]     While the present invention has been described in detail with reference to the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the sprit and scope of the appended claims.