Abstract:
Methods and apparatus for supporting a substrate are provided. According to one aspect of the invention, a substrate support is provided which includes a first major surface comprising a plurality of flat support tiles and a plurality of leveling mechanisms coupled to the plurality of support tiles, wherein the plurality of leveling mechanisms are adapted to level the plurality of flat support tiles with respect to each other so as to provide a flat and level first major surface of the substrate support. Numerous other aspects are provided.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is related to the following commonly-assigned, co-pending U.S. Patent Applications, each of which is hereby incorporated herein by reference in its entirety for all purposes: 
         [0002]    U.S. patent application Ser. No. 10/781,953 filed Feb. 19, 2004 and entitled “METHODS AND APPARATUS FOR POSITIONING A SUBSTRATE RELATIVE TO A SUPPORT STAGE” (Attorney Docket No. 8166); 
         [0003]    U.S. patent application Ser. No. 11/212,043 filed Aug. 25, 2005 and entitled “METHODS AND APPARATUS FOR ALIGNING INKJET PRINT HEAD SUPPORTS” (Attorney Docket No. 9521-6); 
         [0004]    U.S. patent application Ser. No. 11/521,177 filed Sep. 13, 2006 and entitled “METHOD AND APPARATUS FOR MANUFACTURING A PIXEL MATRIX OF A COLOR FILTER FOR A FLAT PANEL DISPLAY” (Attorney Docket No. 10502); and 
         [0005]    U.S. patent application Ser. No. 11/761,832 filed Jun. 12, 2007 and entitled “METHOD AND APPARATUS FOR DEPOSITING INK ONTO SUBSTRATES” (Attorney Docket No. 11127). 
     
    
     FIELD OF THE INVENTION 
       [0006]    The present invention relates to equipment for handling substrates used in the manufacture of color filters for flat panel displays, and more particular, to methods and apparatus for supporting a substrate. 
       BACKGROUND 
       [0007]    Inkjet printing systems are being employed in numerous applications including the manufacture of color filters for flat panel displays (FPDs). In color filter manufacture, ink is jetted onto a matrix formed on a substrate, such as a panel made of glass or polymer. Conventionally, FPDs are produced on standard-sized substrates, such as ‘20K’ substrates, having surface dimensions on the order of 1300 mm by 1500 mm. A number of inkjet printer systems have been configured to accommodate substrates of this size. 
         [0008]    Seventh generation TFT-LCD substrates measure approximately 1,800 mm×2,200 mm (1.8 meters×2.2 meters) and can produce up to eight 40-inch or six 46-inch display objects (e.g., large-screen TV panels) per substrate. The next generations of FPDs in development and future generations are intended to have considerably larger display sizes. These larger FPDs are to be produced on correspondingly larger standard substrates. For example, a new standard substrate size, referred to as a ‘60K’, has surface dimensions on the order of 2600 mm by 2300 mm. 
         [0009]    Conventional inkjet printing systems configured to operate on 20K substrates may not be able to accommodate the larger 60K substrates effectively. In particular, the support stage upon which substrates are mounted in such systems may not be able to support 60K substrates at all in some cases, and in other cases, may do so in a sub-optimal or ineffective way. Inkjet printing systems that can accommodate the next generation 60K substrates would be desirable. 
       SUMMARY OF THE INVENTION 
       [0010]    In an aspect of the present invention, a substrate support is provided which includes (1) a first major surface comprising a plurality of flat support tiles and (2) 
         [0011]    a plurality of leveling mechanisms coupled to the plurality of support tiles, wherein the plurality of leveling mechanisms are adapted to level the plurality of flat support tiles with respect to each other so as to provide a flat and level first major surface of the substrate support. 
         [0012]    In a another aspect of the present invention, an inkjet printing system is provided which includes (1) a movable platform, (2) a substrate support coupled to the moving platform which further includes (i) a first major surface comprising a plurality of flat support tiles and (ii) a plurality of leveling mechanisms coupled to the plurality of support tiles, and (3) a plurality of inkjet print heads adapted to deposit ink onto a substrate positioned on the first major surface of the substrate support, wherein the plurality of leveling mechanisms are adapted to level the plurality of flat support tiles with respect to each other so as to provide a flat and level first major surface of the substrate support. 
         [0013]    In yet another aspect of the present invention, a method of supporting a substrate is provided which includes (1) providing a plurality of support tiles, each of the plurality of support tiles having an area sufficiently small to enable the support tiles to be flattened, (2) flattening the plurality of support tiles, (3) combining the plurality of flat support tiles so as to form a substrate support, and (4) leveling the plurality of support tiles on the substrate support so as to provide a flat and level major surface of the substrate support. 
         [0014]    Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a schematic perspective view of an exemplary inkjet printing system in accordance with embodiments of the present invention. 
           [0016]      FIG. 2  is a schematic top plan view of an exemplary substrate support in accordance with embodiments of the present invention. 
           [0017]      FIG. 3  is a bottom perspective view of an exemplary clamping apparatus in accordance with embodiments of the present invention. 
           [0018]      FIG. 4  is a bottom perspective view of the exemplary substrate support in accordance with embodiments of the present invention. 
           [0019]      FIG. 5A  is a cross-sectional perspective view showing a substrate in a ‘down’ position with respect to the substrate support in accordance with embodiments of the present invention. 
           [0020]      FIG. 5B  is a cross-sectional perspective view showing a substrate in a ‘up’ position with respect to the substrate support in accordance with embodiments of the present invention. 
           [0021]      FIG. 6  is perspective view of an exemplary substrate support and platform in accordance with embodiments of the present invention. 
           [0022]      FIG. 7  is cross-sectional view of an exemplary leveling mechanism in accordance with embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    In inkjet printing systems, substrates to be printed upon are generally placed and supported on a horizontal platform referred to herein as a substrate support. Substrate supports may not be perfectly level, and as supports are manufactured in larger sizes to support larger substrates, surface anomalies and unevenness may be magnified. Due to the high-resolution and strict tolerances employed in current inkjet printing processes, total height differences along the surface of the substrate support on the order of 25 microns or greater may cause inaccuracies in printing operations if not corrected or compensated for. 
         [0024]    To support large substrates (e.g., 60K substrates), an inventive substrate support comprises a plurality of sections or divisions, referred to herein as support tiles. While the entire surface area of the substrate support may be too large to machine (‘flatten’), each of the component support tiles of which the substrate support is formed may be small enough to machine to a high level of flatness. The flattened support tiles may be independently leveled with respect to each other after being installed on the substrate support to provide a uniform substrate support surface. The inventors of the present invention have found that independent leveling of flattened support tiles allows 25 micron tolerances to be achieved. 
         [0025]    A perspective view of an exemplary inkjet printing system that may be employed in the context of the invention is shown in  FIG. 1 . The inkjet printing system  100  as a whole is supported by a frame structure  102  onto which a planar platform  104  may be movably coupled. The platform  104  may be coupled to a driving mechanism  106  which may include, for example, one or more rollers, belts, and/or other transmission devices driven by one or more motors (not shown). The platform  104  may be moved with respect to the frame structure  102  by the driving mechanism  106  in the Y-axis direction (into or out of the page as shown). A substrate support  108  adapted to secure a one more substrates (e.g., 60K and 20K substrates)  110 ,  112  may be coupled to the top surface of the platform  104 . An exemplary embodiment of the substrate support  108  is described in greater detail below with respect to  FIG. 2 . It is noted that substrate supports are sometimes referred to by different terms in the relevant art including: ‘chuck’, ‘system chuck’, and ‘support stage’. The term ‘substrate support’ as used herein is meant to include all devices upon which a substrate is placed and supported in inkjet printing systems and is expressly intended to encompass the aforementioned alternative terms. 
         [0026]    When driven, the platform  104  may convey the substrate support  108  and any substrates  110 ,  112  positioned thereon under a plurality of inkjet print heads  114 ,  115 ,  116  which are adapted to deposit ink into wells (e.g., pixel wells)(not shown) disposed on the substrates  110 ,  112 . As described in previously incorporated U.S. patent application Ser. No. 11/521,177 (Attorney Docket No. 10502), the substrates  110 ,  112  may include black matrix material with which an array of pixel wells may be fabricated. The array of pixel wells disposed on the substrates  110 ,  112  allows specific amounts of different colors of ink to be deposited without blending, enabling a colored pattern to be produced on the substrates  110 ,  112 . For example, each of the inkjet print heads  114 ,  115 ,  116  may be adapted to deposit a different color of ink, such as red (R), green (G) and blue (B) and may be operated so as to produce a color filter for a FPD including sets of Red/Green/Blue pixels on the substrates  110 ,  112 . Other colors and combinations may be used. 
         [0027]    The individual print heads  114 ,  115 ,  116  may be movable independently in the horizontal X-axis direction along a bridge support  118  and may each be rotatable about their respective central axes in the horizontal plane so as to deposit ink over the entire width of the substrates  110 ,  112  at different pitches (horizontal spacings). Additional adjustments may be effected by movement of the bridge support  118  in the Y-axis direction and/or rotation of the bridge support  118  in the horizontal plane as described in previously incorporated U.S. patent application Ser. No. 11/212,043 (Attorney Docket No. 9521-6). Such adjustments may be made to accommodate substrates that are oriented at different angles with respect to the X and Y axes. 
         [0028]    It is noted that while only three print heads  114 ,  115 ,  116  are shown, the inkjet printing system  100  may include a greater number of inkjet print heads (e.g., 6, 9, 12 print heads) arranged on one or more bridge supports. For example, previously incorporated U.S. patent application Ser. No. 11/761,832 (Attorney Docket No. 11127), describes an inkjet printing system which includes four sets of inkjet print heads, in which each set includes three inkjet print heads, totaling twelve (12) inkjet print heads. 
         [0029]    Referring to  FIG. 2 , an exemplary substrate support  108  according to an embodiment of the present invention is shown. In one or more embodiments, the entire surface are of the substrate support  108  may be on the order of approximately 2.7 meters width (X-axis direction) by approximately 2.7 meters length (Y-axis direction). However, the substrate support  108  may have other width and length dimensions. As discussed above, the surface area of a monolithic substrate support may be difficult to machine, grind or polish to the requisite flatness and/or uniformity. According to the invention, a modular substrate support  108  comprises a plurality of support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  which, individually, may be machined, ground, polished, etc. (‘flattened’), to the requisite flatness and uniformity. The individual support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may then be installed together to form the substrate support  108  and leveled (e.g., raised, lowered, aligned, and/or tilted) with respect each other as described further below with respect to  FIG. 7 . 
         [0030]    In the embodiment depicted in  FIG. 2 , the substrate support  108  includes nine (9) support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  arranged in a 3 by 3 configuration (three rows by three columns), in which each support tile has approximately the same shape and surface dimensions (i.e., width and length). In the depicted embodiment, the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may be approximately 0.9 m by 0.9 m. However, it is to be appreciated that a smaller or larger number of tiles may be used (e.g., 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16) and the support tiles may have varied shapes and surface dimensions with respect to each other. 
         [0031]    The substrate support  108  may also include a first spill tray  220   a  positioned at a first longitudinal end of the substrate support  108  coupled to support tiles  202 ,  208  and  214 , and a second spill tray  220   b  positioned at a second longitudinal end of the substrate support  108  coupled to support tiles  206 ,  212  and  218 . The top surfaces of spill trays  220   a ,  220   b  may be positioned slightly lower relative to the top surfaces of support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  such that the spill trays  220   a ,  220   b  may receive ink that spills off of the substrates  110 ,  112  and/or substrate support  108  during printing. Calibration glass  222  may be included on one or more edges of the substrate support  108  for the purpose of aligning a substrate (e.g., 60K substrate  110 ) on the substrate support  108 . In the embodiment depicted, the calibration glass  222  is positioned at a top or back edge of the substrate support  108 . The calibration glass  222  may provide a window for one or more optical devices (e.g., light sources, detectors, not shown) positioned under the substrate support  108  which may facilitate automatic or manual alignment of an edge of the 60K substrate  110 . In one or more embodiments, upper support tiles  202 ,  208 ,  214  may be shaped or have portions removed to provide for the placement of the calibration glass  222 . 
         [0032]    The support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may be made of a metal such as aluminum, or any other material having suitable (e.g., relatively light) weight, rigidity and support strength, so that the substrates  110 ,  112  positioned on substrate support  108  may be securely held in position, may be moved at suitable speeds (e.g., about 0.1 to 2 m/s), and may be brought to rest without causing damage to the substrates  110 ,  112 . The support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may also be coated, for example with an anti-stain surface treatment in order to reduce surface cleaning. In one or more embodiments, each support tile  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may have a weight of about 45 kg to 60 kg. However, other weight tiles may be used. 
         [0033]    The example substrate support  108  including support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  depicted in  FIG. 2  is configured to support 60K standard-sized substrates in both 0 and 90 degree orientations (i.e., with the long dimension of the substrate aligned in the Y-axis direction, or in the X-axis direction). In the embodiment depicted in  FIG. 2 , 60K substrates  110  may be placed and secured at a first, zero (0) degree position  223  (shown in phantom) or at a second, ninety (90) degree position  224  (also shown in phantom) oriented perpendicularly with respect to the first position  223 . As can be discerned the first and second positions  223 ,  224  encompass a substantial portion of the tiled area of the substrate support  108  and portions of each of the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218 . 
         [0034]    In some embodiments (as depicted), the substrate support may also be adapted to support 20K substrates  112  in a first zero (0) degree position  225  (shown in phantom) or at a second, ninety (90) degree position  226  (also shown in phantom) oriented perpendicularly with respect to the first position  225 . 20K substrates  112  may be positioned at other locations and/or orientations on the substrate support  108 . As can be discerned, the area covered by the respective first and second positions  225 ,  226  encompasses a smaller portion of the surface area of substrate support  108 , including substantial portions of tiles  210  and  212  and smaller portions of tiles  204 ,  206 ,  210 ,  216  and  218 . 
         [0035]    Substrates  110 ,  112  may be secured in the first/second positions  223 / 224 ,  225 / 336  at least in part, by application of pneumatic (e.g., vacuum suction) and/or electrical (e.g., electrostatic) forces. The substrates  110 ,  112  may also be secured in the first and second positions  223 / 224 ,  225 / 226  by employing one or more mechanical or electro-mechanical clamping apparatuses as described further below. 
         [0036]    In one or more embodiments, the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may include openings (e.g., holes, lines) that are coupled to a blower/vacuum source such as, for example, a pneumatic assembly (not shown), that may provide either an upward blower pressure or a downward suction force on substrates  110 ,  112  positioned over the openings. In particular, the support tiles  202 ,  204 ,  206 ,  208 ,  212 ,  214 ,  216 ,  218  may include respective blower/vacuum lines  232 ,  234 ,  236 ,  238 ,  242 ,  244 ,  246 ,  248  configured in rectangular arrangements of various sizes to provide suction over several portions of the substrates  110 ,  112 . As shown, the central support tile  210  includes two sets of vacuum lines  240 ,  241  to promote stability in the center of the substrate support  108 . Other pneumatic line configurations may be used. 
         [0037]    In operation, when a substrate  110 ,  112  is placed on a substrate support, an upward pressure is applied via blower/vacuum lines  232 ,  234 ,  236 ,  238 ,  242 ,  244 ,  246 ,  248  so that the substrate  110  may float over the substrate  108 , which enables the substrate  110  to be shifted more easily into a desired position. The blower/vacuum lines  232 ,  234 ,  236 ,  238 ,  240 ,  241 ,  242 ,  244 ,  246 ,  248  and pneumatic assembly may be adapted to provide an upward pressure of approximately 40 to 60 pounds per square inch (psi) although other pressure may be applied. 
         [0038]    The substrate support  108  may include respective clamping apparatuses  250 ,  252 ,  254  and  256  (not shown in detail) adapted to secure respective upper left, lower left, upper right and lower right corners of substrate  110  in either the first or second position  223 ,  224 . In some embodiments, the substrate support  108  may also include additional clamping apparatuses  251 ,  253 ,  255  and  257  adapted to secure respective upper left, lower left, upper right and lower right corners of substrate  112  in either the first or second position  225 ,  226 . 
         [0039]    Referring to  FIG. 3 , an exemplary clamping apparatus (e.g.,  250 ) that may be employed in the context of the present invention is shown in bottom perspective view. A clamping apparatus as described in commonly-assigned application Ser. No. 10/781,953 (Attorney Docket No. 8166) may also be used. The clamping apparatus  250  may include two clamping assemblies  302 ,  304 , each including a stationary clamp mechanism and a rotational clamp mechanism. The stationary clamp mechanism in each clamping assembly  302 ,  304  is adapted to establish a reference position and act as a stop against which an edge (e.g., near a corner) of the substrate  110  may be forcibly secured. The rotational clamp mechanism in each clamping assembly  302 ,  304  is adapted to apply a force (e.g., in the plane of the substrate support  108 ) on an edge of the substrate  110 . In one or more embodiments, the stationary clamp mechanism may include a banking pad (of which one is shown)  306  adapted to moved to and establish a reference position for the substrate  110 . The rotational clamp mechanism may include a movable member such as a push pad  308  and a biasing device such as a spring  310  adapted to apply pressure to an edge of a substrate  110 . 
         [0040]    The clamping apparatus  250  may further include a first actuator  312  (e.g., pneumatic, electro-mechanical, etc.) adapted to move the banking pad  306  in a horizontal direction and a second actuator  314  adapted to move the banking pad  306  in a vertical direction. The first and second actuators  312 ,  314  may be operated so as to move the banking pad  306  into a reference position, to form a stationary boundary against which a corner edge of the substrate  110  may be clamped and secured. In one or more embodiments, the first actuator  312  is adapted to move the banking pad  306  about 10 mm in a horizontal direction and the second actuator  314  is adapted may move the banking pad  306  about 20 mm in a horizontal direction so as to establish an approximately ±10 mm capture range, repeatable up to about within 0.5 mm. Other ranges may be used. 
         [0041]    In operation, to define the area(s)  223 ,  224  in which the substrate  110  is intended to be secured, three reference positions, which together define a plane, may be selected. The reference positions correspond to the locations of three stationary clamping mechanisms of the clamping apparatuses  250 ,  252 ,  254 ,  256 . The three stationary clamping mechanisms (out of eight possible mechanisms) are actuated to move banking pads (e.g.,  306 ) to the three selected reference positions. In some embodiments, the three stationary clamping mechanisms used to establish the reference positions may be selected from clamping apparatus  250 ,  252  and  254  (on the upper left, lower left and upper right corners, respectively), but preferably not from clamping apparatuses  250  and  254  solely, in which case all of the reference positions would be on the same (upper) edge of the substrate  110 . 
         [0042]    In an exemplary clamping process, after a substrate  110  has been placed on the substrate support  108 , an upward pressure may be applied via blower or vacuum lines  232 ,  234 ,  236 ,  238 ,  240 ,  241 ,  242 ,  244 ,  246 ,  248 , allowing the substrate  110  to float over the substrate support  108 . A banking pad  306  of clamping apparatus  250  may be raised over the substrate  110  and moved to a first reference position near the upper left corner of the substrate  110 , a banking pad of clamping apparatus  252  may be raised over the substrate  110  and moved to a second reference position near the lower left corner of the substrate  110  and a banking pad of clamping apparatus  254  may be raised over the substrate  110  and moved near a third reference position at the upper right corner of substrate  110 . It is noted that other stationary clamping mechanisms of the same or other clamping apparatuses may be used. In addition, one or both of the clamping mechanisms (stationary and/or rotational) of a clamping apparatus (e.g.,  302 ,  304 ) may be used in a given clamping operation. 
         [0043]    Once the banking pads have been moved to establish reference positions, as the substrate  110  is floating, rotational clamping mechanisms of the same or other clamping apparatuses  250 ,  252 ,  254 ,  256  may be actuated to apply force onto edges of the substrate  110  (e.g., near the corners) so as to urge the substrate  110  into contact with the banking pads in the reference positions, thus clamping the substrate  110  in the aligned position (e.g.,  223 ) on the substrate support  108 . The substrate  110  may be forcibly maintained in the aligned position by the biasing action of springs in the rotational clamping mechanisms (e.g.,  310 ). 
         [0044]    Once the substrate  110  has been clamped, the upward pressure through blower or vacuum lines  232 ,  234 ,  236 ,  238 ,  240 ,  241 ,  242 ,  244 ,  246 ,  248  may be turned off, and a downward suction force may be activated. In this manner, the substrate  110  is secured by both mechanical clamping and pneumatic suction and may be maintained precisely in a preset, aligned position and orientation even during rapid and/or abrupt movements of the substrate support  108  (e.g., during a printing run). 
         [0045]    Referring now to  FIG. 4 , which depicts a bottom perspective view of the substrate support  108 , a lift frame  402  may be positioned between the movable platform  104  and the substrate support  108  and may be adapted to lift substrates  110 ,  112  off of the substrate support  108  using lift pins  404  (only one labeled) coupled (e.g., rigidly attached) to the lift frame  402 . Each of the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  ( FIG. 2 ) may include respective lift pin openings  262   a - b ,  264   a - d ,  266   a - c ,  268   a ,  270   a - b ,  272   a - b ,  274   a - b ,  276   a - d ,  278   a - c  through which lift pins  404  may extend through the tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  into contact with a substrate  110 ,  112  positioned on the substrate support  108 . Thus, in the particular depicted example embodiment, the substrate support  108  accommodates, through openings in the support tiles, the use of twenty-three (23) lift pins  404 . It is noted however, that other configurations and numbers of lift pin openings may be used to accommodate a different number and configuration of lift pins  404 . 
         [0046]    The lift frame  402  and lift pins  404  may be lifted by action of one or more actuators  406 ,  407  coupled to the lift frame  404 . The lift frame  402  may be coupled to the substrate support  108  by bearings (e.g., linear bearings)  408 ,  409 . Although two actuators  406 ,  407  and bearings  408 ,  409  are shown, a larger or smaller number of actuators and bearings may be used (e.g., 1, 3, 4, 5). In some embodiments, the actuators  406 ,  407  may be pneumatically-driven and may be coupled to the pneumatic assembly (not shown) provided for the operation of the vacuum lines. In additional or alternative embodiments, the actuators  406 ,  407  may be electrically or electromechanically driven, e.g., via one or more motors. 
         [0047]    In operation, when a substrate  110 ,  112  is to be installed on or removed from the inkjet printing system  100 , the actuators  406 ,  407  may be driven to exert an upward force on the lift frame  402  (at one or more points on the frame), which may move the lift frame  402  from a rest or ‘down’ position to an ‘up’ position. The upward movement of the lift frame  402  in turn causes lift pins  404  to move in an upward stroke through openings  262   a - b ,  264   a - d ,  266   a - c ,  268   a ,  270   a - b ,  272   a - b ,  274   a - b ,  276   a - d ,  278   a - c . The upward stroke of the lift pins  404 , which may be about 125 mm in length (other lengths may be used), is sufficient to force the substrate  110 ,  112  off of the substrate support  108  so as to allow a robot end effector or other suitable device to remove the substrate  110 ,  112  from the substrate support  108 . The substrates  110 ,  112  may be supported by the lift pins  404  above the substrate support  108  by approximately the length of the upward stroke. Other stroke lengths and speeds may be used.  FIGS. 5A and 5B  illustrate the respective ‘down’ and ‘up’ positions in cross-sectional perspective view and show relative change from the ‘down’ position in which a substrate (e.g.,  110 ) rests upon the substrate support  108  (shown in  FIG. 5A ) to the ‘up’ position in which the substrate  110  is raised by the lift pins  404  above and off of the substrate support  108  (shown in  FIG. 5B ). In alternative embodiments, other apparatuses and techniques may be used to lift a substrate  110  from the substrate support  108  such as using one or more robot arms, grippers, etc. 
         [0048]    As noted above, each of the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may be flattened before being installed on the substrate support  108 . Upon installation, the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may then be leveled with respect to each other to achieve a flat, level, and co-planar surface across the entire substrate support  108 . According to some embodiments of the invention, each of the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may include one or more level adjustment mechanisms (‘leveling mechanisms’) adapted to adjust the level at one or more points on the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218 . In the exemplary embodiment of the substrate support  108  depicted in  FIG. 2 , a number of leveling mechanisms are shown. As depicted, leveling mechanisms  282   a - d ,  284   a - d ,  286   a - d ,  288   a - d ,  290   a - d ,  292   a - d ,  294   a - d ,  296   a - d  and  298   a - d  are positioned on and adapted to level respective support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218 . 
         [0049]    As depicted, each support tile  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may include four (4) leveling mechanisms. The use of a plurality of leveling mechanisms allows each support tile to be raised or lowered at more than one point on a support tile surface. However, it is noted that a larger or smaller number of leveling mechanisms may be used (e.g., 1, 2, 3, 5, 6, etc.). The leveling mechanisms may be operated automatically using actuators (not shown) or manually (as shown and described below). 
         [0050]    Each of the leveling mechanisms  282   a - d ,  284   a - d ,  286   a - d ,  288   a - d ,  290   a - d ,  292   a - d ,  294   a - d ,  296   a - d ,  298   a - d  coupled to support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may also be coupled to one or more base supports which may comprise a plate, frame, post or the like, and which may serve as a fixed reference point for the operation of the leveling mechanisms and also as a support.  FIG. 6  is a perspective view of an exemplary substrate support  108  and planar platform  104  according to an embodiment of the invention. As shown, each of the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  rest on a respective plurality of posts  602   a - d ,  604   a - d ,  606   a - d ,  608   a - d ,  610   a - d ,  612   a - d ,  614   a - d ,  616   a - d ,  618   a - d , which, in turn, are fixedly coupled to the planar platform  104 . In at least one embodiment of the invention, each one of the leveling mechanisms  282   a - d ,  284   a - d ,  286   a - d ,  288   a - d ,  290   a - d ,  292   a - d ,  294   a - d ,  296   a - d ,  298   a - d , is coupled to one of the respective posts  602   a - d ,  604   a - d ,  606   a - d ,  608   a - d ,  610   a - d ,  612   a - d ,  614   a - d ,  616   a - d ,  618   a - d . However, other arrangements for coupling the leveling mechanisms  282   a - d ,  284   a - d ,  286   a - d ,  288   a - d ,  290   a - d ,  292   a - d ,  294   a - d ,  296   a - d ,  298   a - d  may be employed. 
         [0051]      FIG. 7  is a cross-sectional view of an example of a leveling mechanism  700  that may be used with the inventions disclosed herein. In the depicted embodiment, the leveling mechanism  700  may include an AFAB™ alignment kit manufactured by and commercially available from Silicon Valley Automation of Forney, Tex. In some embodiments, each of the leveling mechanisms  282   a - d ,  284   a - d ,  286   a - d ,  288   a - d ,  290   a - d ,  292   a - d ,  294   a - d ,  296   a - d ,  298   a - d  discussed above with respect to  FIG. 2  may include similar leveling mechanisms  700 . In additional and/or alternative embodiments, other leveling mechanisms may be used. The leveling mechanism  700  may include an annular threaded adjustment member  702  having a hollow portion  703  which is adapted to rest on a fixed base  704  (such as posts  602   a - d , etc., shown in  FIG. 6 ) at a first end  705 , and to extend into an opening  706  of a support tile  202  at a second end  707  such that a gap  708  is maintained between the surface of the fixed base  704  and the surface of the support tile  202  opposite the surface of the fixed base  704 . 
         [0052]    An annular keyed adjustment member  710  may be positioned in the opening  706  of the support tile  202  above the threaded adjustment member  702 . The keyed adjustment member  710  includes a first section  711  having a first outer annular radius, and a second portion  712  having a second outer annular radius smaller than the outer annular radius of the first section  711 . It is to be appreciated that the opening  706  in the support tile  202  includes corresponding portions of different diameters to accommodate the first and second sections  711 ,  712  of keyed adjustment member  710 . 
         [0053]    The first section  711  of the keyed adjustment member  710  may include a hollow portion  714  adapted to receive an adjustment tool and a solid portion  715  situated under the hollow portion  714 . Toward the opposite end of the first section  711  from the hollow portion  714 , a flange  716  is formed at the conjunction of the first and section sections  711 ,  712  of the keyed adjustment member  710 . The flange  716  rests on a corresponding ledge  718  formed in the opening  706  of the support tile  202  formed where the wider and narrower portions of the opening  706  meet. 
         [0054]    The second section  712  of the keyed adjustment member  710  is adapted to extend into the hollow portion  703  of the threaded adjustment member  702 . A screw  720  having a head  722  adapted to receive a tightening tool (e.g., an Allen wrench) may be positioned to extend through both the keyed adjustment member  710  and the threaded adjustment member  702  into the fixed base  704 , which may include a corresponding threaded opening  723  to receive the screw  720 . The head  722  of the screw  720  is adapted to contact the first section  711  of the keyed adjustment member  710  while a bottom portion of the screw  720  may be threadably coupled to the threaded adjustment member  702  and fixed base  704 . 
         [0055]    In operation, after the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  have been flattened and assembled on a substrate support  108 , the leveling mechanisms  282   a - d ,  284   a - d ,  286   a - d ,  288   a - d ,  290   a - d ,  292   a - d ,  294   a - d ,  296   a - d ,  298   a - d  may be inserted into the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  and then adjusted to level the entire surface of the substrate support  108 . 
         [0056]    The insertion and adjustment of an individual leveling mechanism  700  may proceed as follows. The threaded adjustment member  702  and keyed adjustment member  710  are inserted into opening  706  in a support tile (e.g.,  202 ). The screws  720  may then be inserted and threaded into the fixed base  704  preferably without substantially tightening the screw  720 . An adjustment tool (not shown) may then be inserted into the hollow portion  714  of the first section  711  of the keyed adjustment member  710 . The adjustment tool engages the solid portion  715  of the first section  711  of the keyed adjustment member  710  and the screw  720 . By turning the adjustment tool, a downward pressure may be brought to bear on the head  722  of the screw  720  and the solid portion  715  of the first section  711  of keyed adjustment member  710 . In response to the application of downward pressure, solid portion  715  may move through the hollow portion  703  of the threaded adjustment member  702 . Downward movement of the solid portion  715  is directly translated to the support tile  202  as downward pressure of the flange  716  acts on the ledge  718  in opening  706  causing a corresponding downward movement of the support tile  202 , reducing the gap  708  between the support tile  202  and the fixed base  704 . In this manner, the gap  708  may be adjusted to a desired level. Once the desired gap level has been reached, the screw  720  may be tightened to secure the components of the leveling mechanism  700  in place. It is noted that while the exemplary leveling process described which employs the depicted mechanical leveling mechanism  700  is a manual process, other leveling mechanisms may be used which may, for example, function automatically using sensors and actuators which may, for example, employ open or closed-loop feedback to reach a desired gap level. 
         [0057]    As a support tile  202  may include a plurality of leveling mechanisms  700  at separate locations, the support tile  202  may be leveled by setting the gap  708  at each location to the same level. The same principal applies to the entire substrate support  108  as the plurality of support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may be adjusted via their respective leveling mechanisms so as to initially set the gap between the support tiles and the fixed bases positioned under each support to the same level. In one or more embodiments, the leveling mechanism  700  and/or the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  may be equipped with a level indicator (not shown) adapted to indicate whether or not an individual support tile has been leveled. The level indicator may comprise, for example, a bubble encased in fluid, or any other suitable level sensor (e.g., an optical sensor including an interferometry device which may detect misalignment, etc.). 
         [0058]    It is noted that the respective fixed bases positioned under the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  (e.g., posts  602   a - d ,  604   a - d ,  606   a - d ,  608   a - d ,  610   a - d ,  612   a - d ,  614   a - d ,  616   a - d ,  618   a - d ) may not be precisely the same height. In this case, to achieve a level substrate support  108  surface, the gaps between the support tiles  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218  and their respective fixed bases  704  may be adjusted to different levels to accommodate the different heights of the bases. Since the correct gaps may not be precisely known in advance, the same or additional level indicators may also be incorporated on the substrate support  108  to indicate whether one or more support tiles have or have not been leveled with respect to each other. 
         [0059]    The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and method which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, the substrate support may accommodate and/or include a maintenance module adapted to treat the inkjet print heads, and a vision microscope and/or a drop visualization system adapted to ensure proper printing alignment. 
         [0060]    Further, the present invention may also be applied to spacer formation, polarizer coating, and nanoparticle circuit forming. 
         [0061]    Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims.