Abstract:
A system is provided for transferring a substrate of a flat panel display between the processing stations of a flat panel display manufacturing line. The system includes a transfer device that transfers a transfer container in which a substrate is loaded, a container loading and unloading device that loads and unloads the containers on and from the transfer device, and a substrate loading and unloading device that transfers the substrates between the container and processing equipment located at the respective stations. The transfer device includes a track mounted on a facility floor and a plurality of wheeled carriages that move programmably along the track by means of linear motors. The system enables substrate transfer time to be reduced substantially, yet provides robust protection of the substrates throughout the transfer process.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority under 35 U.S.C. § 119 of Korean Patent Application No. 2005-0063233, filed Jul. 13, 2005, the disclosure of which is incorporated herein by reference in its entirety.  
       BACKGROUND  
       [0002]     (1) Field of the Invention  
         [0003]     The present invention relates to a system for automatically transferring substrates of flat panel displays between the processing stations of a flat panel display manufacturing line.  
         [0004]     (2) Description of the Related Art  
         [0005]     Currently, flat panel displays, such as liquid crystal displays (“LCDs”), organic light emitting diode displays and the like, are used in a wide variety of display applications.  
         [0006]     A flat panel display is produced by conveying a glass substrate to processing equipment located at the respective stations of a flat panel display manufacturing line using a transferring system and then performing one or more manufacturing processes on the substrate at each of those locations.  
         [0007]     A conventional flat panel display transferring system includes a “cassette,” a “stoker,” a “conveyor,” and an “indexer.” In the conventional system, the cassette, in which a plurality of substrates is loaded, is stored in the stoker, and the stoker with the stored cassettes is carried to the entrance of processing equipment using the conveyor. The indexer is then used to move the substrates in the cassette into and out of the processing equipment at the respective entrances of the processing stations.  
         [0008]     However, conventional panel display conveying systems that use a cassette, stoker, conveyor, and indexer necessarily involve the presence of redundant in-process components, and can thus incur substantial costs in maintaining the redundant in-process components in the manufacturing line.  
       BRIEF SUMMARY  
       [0009]     In accordance with the exemplary embodiments described herein, the present invention overcomes the above problems by the provision of apparatus and methods for transferring flat panel displays within a flat panel display manufacturing line that minimizes both component transfer time and the number of in-process components present in the line.  
         [0010]     According to one exemplary embodiment thereof, a flat panel display transferring system comprises a transfer device that transfers a container in which a substrate is loaded, and a container loading and unloading (“LU”) device that loads and unloads the container to and from the display processing equipment located at the respective processing stations of the line. The transfer device can include a fixed member, such as a track, mounted on floor of the facility and a plurality of moveable members, such as wheeled trucks, or carriages, that move along the fixed member.  
         [0011]     The fixed member preferably includes a center track forming a closed loop and one or more looping branch tracks that branch out from the center track and are connected to the entrances of the respective display processing stations of the manufacturing line. In one exemplary embodiment, each of the center and branch tracks includes elongated rails and a plurality of coils disposed between the rails. For example, the tracks can comprise two parallel rails that are spaced apart from each other at a predetermined distance, with the plurality of coils being arranged at predetermined intervals along the length of the rails. Each of the rails preferably includes extensions that extend upwardly from the outer edges thereof.  
         [0012]     The carriages include a container support bed, a permanent magnet mounted under the bed and disposed in a spaced apart, overlying relationship with the coils, and wheels mounted under the bed and adapted to engage and roll along the rails. Preferably, auxiliary wheels that contact the upstanding extensions of the rails are also included below the bed. The coils of the track and the permanent magnet of the carriages define a linear motor that controllably propels the carriages along the tracks.  
         [0013]     The substrate transfer container includes a lattice-shaped base frame, a plurality of upstanding support frames mounted on the base frame, a plurality of first support pins mounted on the first support frame that support the substrate, and a container cover that covers the substrate. A base cover that closes the space between lattice beams of the base frame is also included. A side surface of the container cover is openable and closable, e.g., by means of a hinged closure, or door. The container can also include additional substrate support frames and pins mounted on top of each other for simultaneous transportation of a plurality substrates in a stacked fashion.  
         [0014]     The container LU device includes an enclosure having an interior space and a vertical transfer device, or elevator, mounted in the enclosure. A fan unit having an air cleaning filter is mounted on the frame and arranged to blow filtered air into the enclosure to prevent the entrance of contaminants. The elevator operates to move the container in a vertical direction within the enclosure. The enclosure of the LU device includes an opening at a side surface thereof, the container LU device is mounted adjacent to each of the entrances of the processing stations, and a track of the system is laid out to pass through a lower side of the container LU device.  
         [0015]     In one exemplary embodiment, a substrate loading and unloading (“LU”) robot is mounted between the container LU device and the respective entrances of each of the processing stations. The LU robot includes a support portion, a horizontal and vertical transfer portion mounted on the support portion, and a transfer arm mounted on the horizontal and vertical transfer portion. A substrate loaded on the transfer arm of the robot is transferred from the transfer container to the equipment of a processing station through the opening of the enclosure of the LU device, and the transfer arm of the robot is arranged to move between the LU device and the processing equipment by way of the shortest path.  
         [0016]     In an alternative embodiment, a transfer conveyor is mounted between the LU device and the processing equipment, and a container conveyor is mounted in the transfer container such that the two conveyors are located in line with each other and at the same vertical level.  
         [0017]     In accordance with an exemplary method of the present invention, a method of transferring a flat panel display includes positioning a carriage, which moves along a track and on which a transfer container is loaded, below a container LU device, raising the container with an elevator mounted in the container LU device, and transferring a display substrate contained in the container into the equipment located at a display processing station. When the substrate has been transferred into the processing equipment, the empty carriage moves away from the station along the track.  
         [0018]     The method further includes lowering the transfer container with the elevator to load the container onto a second carriage, and moving the second carriage away from the station along the track.  
         [0019]     The method can further include opening a side surface of the container, introducing the transfer arm of a LU robot located between the container device and the processing equipment into the transfer container through an opening of the container LU device, loading the substrate onto the transfer arm, moving the transfer arm into the processing station, and placing the substrate in the processing equipment of the station.  
         [0020]     In an alternative embodiment of the method, the transfer container can include a container conveyer upon which the substrate is loaded, and transferring of the substrate contained in the container can include opening a side surface of the transfer container, positioning a transfer conveyor mounted between the container LU device and the processing equipment and positioned in line with and at the same vertical level as the container conveyer, and simultaneously driving the transfer conveyor and the container conveyor, thereby carrying the substrate loaded on the container conveyor into the equipment of a processing.  
         [0021]     According to another aspect of the present invention, a method is provided for transferring a flat panel display between the processing stations of a manufacturing line, including positioning a first moveable member that moves along a fixed member and on which a transfer container is loaded below a container LU device, and transferring a substrate contained in the transfer container into the equipment of a processing station by a substrate LU robot located between the container LU device and the station.  
         [0022]     The transferring of the substrate contained in the transfer container can include opening a side surface of the transfer container, introducing a transfer arm of a substrate LU robot located between the container LU device and the processing station into the transfer container through an opening of the container LU device, loading the substrate onto the transfer arm, moving the transfer arm into the processing station, and placing the substrate in the processing equipment of the station.  
         [0023]     In an alternative embodiment of the method, the transferring of the substrate contained in the transfer container may include opening a side surface of the transfer container, simultaneously driving a transfer conveyor mounted between the container LU device and the processing equipment and a container conveyor mounted in the transfer container, and carrying the substrate loaded on the container conveyor into the processing equipment. Preferably, the transfer conveyor and the container conveyor are located in line with each other and at the same vertical level.  
         [0024]     A better understanding of the above and many other features and advantages of the panel display substrate transfer system of the present invention may be obtained from the detailed description of the exemplary embodiments thereof below, particularly if such consideration is made in conjunction with the several views of the appended drawings, wherein like reference numerals are used to identify like elements illustrated in one or more of the figures thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]      FIG. 1  is an upper side schematic perspective view of a first exemplary embodiment of a system for transferring flat panel display substrates between the processing stations of a display manufacturing line in accordance with the present invention;  
         [0026]      FIGS. 2A, 2B  and  2 C are top plan, cross-sectional elevation, and upper side perspective views, respectively, of a transfer device of the system of  FIG. 1 ;  
         [0027]      FIG. 3  is an upper side perspective view of a transfer container of the system of FIG  1 ;  
         [0028]      FIG. 4  is an upper side perspective view of a container loading and unloading device of the system of  FIG. 1 ;  
         [0029]      FIGS. 5-8  are cross-sectional elevation views sequentially illustrating the loading and unloading of a substrate to and from a processing station using the container loading and unloading device and a transfer robot of the system of  FIG. 1 ;  
         [0030]      FIG. 9  is a cross-sectional elevation view of a second exemplary embodiment of a flat panel display substrate transferring system in accordance with the present invention, illustrating the loading and unloading of a substrate to and from a display processing station using a container loading and unloading device and a transfer robot thereof; and,  
         [0031]      FIGS. 10 and 11  are cross-sectional elevation views of a third exemplary embodiment of a flat panel display substrate transferring system in accordance with the present invention, sequentially illustrating the loading and unloading of a substrate to and from a display processing station using a container loading and unloading device and a pair of inline conveyors thereof. 
     
    
     DETAILED DESCRIPTION  
       [0032]      FIG. 1  schematically illustrates a first exemplary embodiment of a system for transferring the substrates of flat panel displays between the processing stations of a display manufacturing line in accordance with the present invention.  FIGS. 2A, 2B  and  2 C are top plan, cross-sectional elevation, and upper side perspective views, respectively, of a transfer device of the system of  FIG. 1 .  
         [0033]     As illustrated in  FIGS. 1-2C , the panel transferring system includes transfer devices  100 ,  140 , and  200  for transferring a transfer container  10  in which a display substrate  5  (see  FIG. 5 ) is loaded between the processing stations of the line, and a container loading and unloading (“LU”) device  300  for loading and unloading of the transfer container  10  to and from the equipment located at the respective stations  500 . A connection device  400  is provided between the processing stations  500  and the container LU device  300 . In the exemplary embodiment illustrated in  FIGS. 1-2C , a substrate loading and unloading (“LU”) robot  60  is mounted in the connection device  400 .  
         [0034]     The transfer devices  100 ,  140 , and  200  comprise tracks  100  and  200  mounted on the floor of the production facility, and a plurality of carriages  140  that move along the tracks  100  and  200  between the processing stations  500 . As illustrated in  FIG. 1 , the tracks  100  and  200  include a center track  100  forming a closed loop, and one or more looping branch tracks  200  that branch out from the center track  100  and are connected to the entrances of the respective processing stations  500 . As illustrated in  FIG. 2A and 2B , each of the center track  100  and the branch tracks  200  includes a pair of elongated rails  110  and  120 , and a plurality of coils  130  disposed between the rails at spaced intervals along their length. The rails  110  and  120  are parallel with and spaced apart from each other at a selected distance, and have extensions  111  and  121  which extend upwardly from the outer edges of the rails  110  and  120 .  
         [0035]     Each of carriages  140  includes a horizontal support bed  141 , a permanent magnet  150  mounted below the bed in a spaced apart, overlying relationship with the coils  130 , and wheels  161  and  162  respectively mounted on opposite sides of and below the bed and arranged to engage and roll along the rails. In the particular exemplary embodiment illustrated, the bed includes a pair of horizontal slats  145 , which help support the bed and prevent it from being warped or wracked by heavy loads.  
         [0036]     As illustrated in  FIGS. 2A and 2B , the support bed  141  of the carriage  140  also includes auxiliary wheels  171  and  172 , which are mounted below the support bed  141  to contact the respective upright extensions  111  and  121  of the rails  110  and  120 . The auxiliary wheels  171  and  172  apply a force toward the respective extensions  111  and  121  of the rails  110  and  120  such that lateral movement and yawing of the carriage  140  on the rails is resisted, thereby preventing the carriage from being easily derailed from the tracks  100  and  200  during operation.  
         [0037]     As those of skill in the art will appreciate, the permanent magnet  150  of the carriage  140  and the coils  130  of the tracks  100  and  200  define a linear motor that is capable of moving the carriage along the tracks stably, at a relatively high speed of about 200 m/minute. Thus, the carriages  140  do not need to be connected with a power supply unit, and further, do not require any mechanical element for the delivery of motive power. Accordingly, the carriages can be light in weight and programmed to move rapidly and with precision to any position along the tracks  100  and  200 .  
         [0038]     The center track  100  and the branch tracks  200  stably guide the carriages  140  in a predetermined path such that the carriages  140  cannot separate from the tracks during movement along either straight or curved portions thereof, and further, the carriages  140  can efficiently and stably change their direction of travel at junctions between the center and branch tracks  100  and  200 .  
         [0039]     In a preferred embodiment, the tracks  100  and  200  are connected to a communication device, such as a serial communication device or a field bus, such that operational information, including speed and position of the carriages  140 , can be monitored and controlled by a computer. Additionally, an interlocking device can be provided to prevent collisions between the carriages  140  during operation of the system. Addition fail-safe devices can be provided in the system such that a malfunction of one carriage  140  or the driving coil  130  associated with it can stop driving of the other carriages  140  and/or associated driver coils  130 .  
         [0040]     It should be further understood that, in the case of a conventional panel display transfer system of the type that uses a stoker, when the stoker malfunctions, the entire manufacturing process must be halted. However, in the transfer system of the present invention, if one carriage  140  is out of order, movement of the other carriages  140  within the system can be quickly resumed simply by removing only the malfunctioning carriage  140  from the system.  
         [0041]     Further, since the tracks  100  and  200  of the system can be easily laid, maintained and even waterproofed, if desired, the transfer system can be readily deployed in a processing line that uses moisture-aversive chemical agents, such as a cleaning line.  
         [0042]     Additionally, it may be seen that an increase in production capacity is readily obtainable simply by increasing the number of carriages  140 , and moreover, the travel path of the carriages  140  can be more rapidly and easily expanded as compared with a conventional conveyor system.  
         [0043]      FIG. 3  is an upper side perspective view of a transfer container  10  of the first embodiment of the flat panel display transferring system of the present invention. As illustrated in  FIG. 3 , the transfer container  10  includes a lattice-shaped base frame  11 , a plurality of support frames  13  mounted on the base frame  11 , first support pins  14  mounted on the support frame  13  and supporting a display substrate  5 , and a protective container cover  15  that covers the substrate  5 .  
         [0044]     The base frame  11  of the container  10  is provided with a lattice shape such that it is light in weight but strong so as to prevent it from being warped or wracked by the weight of a large substrate  5 . Base plugs, or covers  12 , are mounted in the openings between the lattice beams to prevent foreign material from entering the container through the openings.  
         [0045]     The first support pins  14  are mounted as a group and are spaced apart from each other at a selected intervals. Accordingly, an arm of a substrate loading and unloading (“LU”) robot  60  of the type described below can enter into the spaces between the first support pins  14 , lift up a substrate  5  supported on the pins, and carry it out of the transfer container  10 .  
         [0046]     Additional support frames and support pins (not illustrated) can be mounted above the first support frame  13  and pins  14  at selected vertical intervals, to support additional substrates  5  in the container in a stacked fashion. Thus, it should be understood that, although the particular transfer container  10  illustrated in the figures is shown as carrying only one substrate  5 , the container is can easily be configured to carry a plurality of substrates simultaneously. Preferably, the side surface of the container cover  15  is openable and closed by way of a hinged closure to prevent contamination of the substrates by foreign matter during transit. Accordingly, when the closure of the side surface of the container cover  15  is opened, the substrate LU robot  60  can either carry a substrate  5  out of the transfer container  10  or transfer a substrate from the processing station  500  into the container. Alternatively, the upper surface of the container cover  15  can incorporate a closure (not illustrated) that opens to enable the substrate LU robot  60  to carry the substrate  5  from the transfer container  10  to the processing equipment  500 .  
         [0047]     In the exemplary embodiment illustrated, the base frame  11  of the transfer container  10  is made of an aluminum (Al) alloy or carbon fiber reinforced plastic (CFRP), the base cover(s)  12  and the container cover  15  are made of polycarbonate, and the first support frame  13  and the first support pins  14  are made of carbon fiber reinforced plastics. Accordingly, the resulting transfer container  10  is both light in weight, strong and rigid, is easily maintained, and is difficult to deform. Since the transfer container  10  in which the substrate  5  is loaded moves to the respective processing stations  500  by way of the carriages  140 , the container can either transfer or store the substrate  5  while maintaining the high level of cleanliness required of a flat panel display manufacturing facility. Furthermore, the transfer container  10  can prevent the substrate  5  from being scratched or damaged when it is being transferred.  
         [0048]      FIG. 4  is an upper side perspective view of the container loading and unloading (“LU”) device  300  of the exemplary first embodiment of the flat panel display transferring system. As illustrated in  FIG. 4 , the container LU device  300  is mounted adjacent to the entrance of a display processing station  500  (see  FIG. 5 ), and the rails and driving coils  110 ,  120 , and  130  of the tracks pass through the lower side of the container LU device  300 . The container LU device  300  includes a rectangular enclosure  51  enclosing an internal space in which a vertical transfer device, i.e., an elevator  54 , is mounted. The enclosure  51  has openings  52  at its front and rear lower surfaces and openings  53  at its side surfaces. The rails and driving coils  110 ,  120 , and  130  of the tracks pass through the front and rear openings  52  of the enclosure  51 .  
         [0049]     The elevator  54  is mounted outside of the rails  110  and  120  that pass through the enclosure  51 , and is adapted to raise a transfer container  10  up from or lower it down onto a carriage  140  disposed on the rails, i.e., to transfer the transfer container  10  in a vertical direction relative to the rails and the carriage  140 .  
         [0050]     As illustrated in  FIG. 4 , a substrate LU robot  60  is arranged to unload a substrate  5  directly from the transfer container  10  to the processing equipment  500 . The substrate LU robot  60  is mounted between the container LU device  300  and the entrance of the substrate processing station  500  (see  FIG. 5 ), and includes a support portion  61 , a horizontal and vertical (“HV”) transfer portion  62  mounted on the support portion  61 , and a transfer arm  63  mounted on the HV transfer portion  62 . The HV transfer portion  62  moves the transfer arm  63  in a Y or Z direction, and the transfer arm  63  moves between the container LU device  300  and the entrance to the equipment of the processing station  500  by a straight-line, i.e., the shortest path, thereby minimizing substrate transfer time. Thus, during the loading or unloading of a substrate  5 , the substrate LU robot  60  is not required to rotate about a Z-axis, and the transfer arm  63  is required to move only in the XY plane.  
         [0051]     In addition, unlike a substrate LU robot  60  used in a conventional transfer system that includes a stoker, since the substrate LU robot  60  of the present embodiment needs to move only a small amount in the Z direction to be able to lift and place the substrate  5 , the amount of movement of the substrate  5  in the Z direction is relatively much smaller, and hence, the time required to load or unload the substrate  5  is relatively shorter.  
         [0052]     In operation, the transfer arm  63  of the substrate LU robot  60  enters into the transfer container  10  through the opening  53  in the side of the enclosure  51 , loads the substrate  5  thereon, then translates to the entrance of the processing station  500  and thereby carries the substrate  5  into the processing equipment located therein.  
         [0053]     As illustrated in  FIG. 4 , a fan unit  55  with an air filter is mounted on the enclosure  51  of the container LU device  300  and arranged to blow clean air downward into the enclosure  51 . As a result, contaminated air is prevented from entering into the transfer container  10 , and thus, dust is prevented from attaching to the substrate  5  when opening and closing the transfer container  10 . Thus, the cleanliness required in the flat panel display manufacturing facility can be maintained even during container loading and unloading.  
         [0054]     FIGS.  5  to  8  sequentially illustrate a method of loading or unloading a panel display substrate  5  to or from a substrate processing station  500  using the container LU device  300  and the substrate LU robot  60  of the first exemplary embodiment of the system of the present invention.  
         [0055]     As illustrated in  FIG. 5 , a carrier  140  is first loaded with a transfer container  10  containing one or more display substrates  5  and then propelled along the rails  110  and  120  of the tracks by the linear motor elements  130  and  150   a  to a position directly below the container LU device  300 , which is mounted adjacent to the entrance of a target processing station  500 , with a transfer device  400  incorporating a substrate LU robot  60  disposed therebetween.  
         [0056]     Next, as illustrated in  FIG. 6 , the transfer container  10  is raised by the elevator  54  of the container LU device  300  to a level that is slightly higher than the upper surface of the arm  63  of the substrate LU robot  60 .  
         [0057]     Then, as illustrated sequentially in  FIGS. 7 and 8 , the transfer arm  63  of the substrate LU robot  60  enters into the transfer container  10 , lifts the substrate  5  up from the support pins of the container, and translates it into the entrance of the processing station  500 . That is, as illustrated in  FIG. 7 , the hinged side surface  15   a  closure, or door, of the transfer container  10  is opened, and the transfer arm  63  of the substrate LU robot  60  enters through the side opening  53  of the container LU device  300  and into the transfer container  10 , as described above. The substrate  5  is then loaded onto the transfer arm  63 , and as illustrated in  FIG. 8 , the transfer arm  63  then moves into the processing station  500  and places the substrate  5  therein.  
         [0058]     When the substrate  5  is placed in the processing station  500 , the empty carriage  140  can then depart by way of the rails  110 ,  120  of the tracks  100 ,  200  to a next destination thereon. A second empty carriage  140  can then be moved along the tracks and positioned below the container LU device  300 . The empty transfer container  10  is then lowered by the elevator  54  and loaded onto the second carriage. The second carriage  140  can then depart, carrying the empty transfer container  10  to a next destination along the tracks.  
         [0059]     As will be appreciated, when it is desired to move a processed substrate  5  from a processing station  500  to another destination, e.g., a second processing station  500  in the manufacturing line, the foregoing procedure is simply effected in the reverse order.  
         [0060]     Since the carriages  140  can move continuously and independently of each other along the rails  110 ,  120  except when a transfer container  10  is being loaded or unloaded to or from them, transfer delays do not occur in the system and substrate transfer time is substantially reduced.  
         [0061]     Furthermore, since a plurality of substrates  5  can be transferred simultaneously using the same transfer container  10  and linear motor system, the number of in-process components can be significantly reduced. In addition, the cumulative substrate transfer time is substantially reduced by the more direct connection between the manufacturing process stations afforded by the system.  
         [0062]     As will be appreciated, in a factory manufacturing line, the in-process components are those that are being manufactured on the line at a given point in time. In general, since the same components are being successively processed in the factory, the in-process components exist in each stage of processing. Accordingly, the amount of the in-process components in each processing stage is generally calculated as inventory. In the system of the present invention, since the substrates  5  are successively transferred without the use of a conventional stoker, the transfer system operates without interruption or the need to provide redundant in-process components, and thus, the number of in-process components, i.e., excess inventory, is reduced.  
         [0063]     A second exemplary embodiment of a system for transferring flat panel displays between the processing stations of a panel display manufacturing line in accordance with the present invention is illustrated in the schematic cross-sectional elevation view  FIG. 9 , wherein like reference numerals are used to identify elements that are the same or similar to those of the first embodiment described above.  
         [0064]     As illustrated in  FIG. 9 , a carriage  140  loaded with a transfer container  10  containing a display substrate  5  is propelled along the rails  110 ,  120  of a track by the linear motor  130 ,  150   a  and then positioned directly below a container LU device  300  disposed adjacent to the entrance of a target display processing station  500 , with a transfer device  400  incorporating a substrate LU robot  60  disposed therebetween. Next, the substrate  5  in the transfer container  10  is carried directly into the processing equipment of the station  500  by the substrate LU robot  60 . That is, the hinged closure  15   a  in the side surface of the cover  15  of the transfer container  10  is first opened. The transfer arm  63  of the substrate LU robot  60  then enters into the transfer container  10  through the opening  53  of the container LU device  300 , and the substrate  5  is loaded onto the transfer arm  63 . The transfer arm  63  then moves into the equipment of the processing station  500  and places the substrate  5  therein.  
         [0065]     As may be seen by a comparison of  FIGS. 5 and 9 , the second embodiment differs from the first embodiment in that the substrate LU robot  60  transfers the substrate  5  contained in the transfer container  10  into the processing equipment  500  directly without raising the transfer container  10  off of the carriage  140 . That is, since the substrate  5  is initially disposed in the container  10  on the carriage  140  at a level slightly above that of the arm  63  of the substrate LU robot  60 , the step of raising the container  10  with an elevator  54  disposed in the container LU device  300  is unnecessary, and accordingly, the latter feature is eliminated from the second exemplary embodiment.  
         [0066]     A third exemplary embodiment of a system for transferring flat panel display substrates between the processing stations of a panel display manufacturing line in accordance with the present invention is illustrated in the schematic cross-sectional elevation view  FIG. 10 , wherein like reference numerals are used to identify elements that are the same as or similar to those of the first and second embodiments described above.  
         [0067]     The third embodiment of  FIG. 10  differs from the first and second embodiments above in that, instead of a substrate LU robot  60 , a transfer conveyor  71  is mounted between the container LU device  300  and the processing station  500 , and in the particular embodiment illustrated in  FIG. 10 , a second, container conveyor  72  is also mounted within the transfer container  10 .  
         [0068]     In a method of transferring flat panel displays using the transfer system of  FIG. 10 , a carriage  140  carrying a transfer container  10  having a container conveyor  72  with a substrate  5  loaded thereo is propelled along the rails  110 ,  120  of a track by the linear motor  130 ,  150   a  and positioned directly below the container LU device  300  mounted at the entrance of a target processing station  500 , as in the above embodiments.  
         [0069]     When positioned in the container LU device  300 , the transfer container  10  is raised by the elevator  54 , and the substrate  5  contained in the transfer container  10  is then transferred into the equipment of the processing station  500  by the transfer conveyor  71 . That is, the hinged closure  15   a  in the side surface of the transfer container  10  is first opened. The transfer conveyor  71  mounted between the container LU device  300  and the processing station  500  and the container conveyor  72  mounted in the transfer container  10  are positioned in line with each other and at the same vertical level. The transfer conveyor  71  and the container conveyor  72  are simultaneously driven and the substrate  5  is thereby carried from the container conveyor  72  to the transfer conveyor  71 , which then carries the substrate into the processing station  500 .  
         [0070]     When the substrate  5  contained in the transfer container  10  is transferred into the processing station  500 , the empty carriage  140  moves away to a next destination along the tracks.  
         [0071]     Next, as illustrated in  FIG. 11 , a second empty carriage  140  is moved along the rails  110 ,  120  and positioned below the container LU device  300 . The empty transfer container  10  is then lowered by the elevator  54  and loaded onto the second carriage, which then moves away to a programmed next destination along the tracks.  
         [0072]     According to the present invention, since a transfer device and a container LU device driven by a linear motor are used, the time to transfer a substrate between processing stations can be reduced substantially. Furthermore, since the substrates are transferred in protective transfer containers, the substrates are transferred more cleanly and safely.  
         [0073]     Furthermore, since the substrates are transferred using a plurality of transfer containers, rather than with a stoker and a cassette, the number of transfers required is minimized, and the number of in-process components in the system, and hence, in-process inventory, is reduced.  
         [0074]     In addition, a track system that incorporates a linear motor system is one that is easily set up and maintained, and a transfer system using the same can be flexibly embodied in accordance with the needs of the production processing, and production capacity is thus easily expanded.  
         [0075]     Moreover, even if specific manufacturing processing equipment is out of order, the other processing equipment is not affected and thus processing flexibility can be ensured.  
         [0076]     In addition, since a conventional cassette, stoker, conveyor, and indexer are not used, the initial investment cost of the processing equipment can be significantly reduced, and since the substrates are managed and transferred entirely within the transfer container, the number of in-process components can be significantly reduced at each stage of processing.  
         [0077]     By now, those of skill in this art will appreciate that many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of the substrate transferring system of the present invention without departing from its spirit and scope. In light of this, the scope of the present invention should not be limited to that of the particular embodiments illustrated and described herein, as they are only exemplary in nature, but instead, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.