Abstract:
An air track included a first body having a concave top surface with a plurality of air outlets or a flat surface with a notch and a plurality of air outlets. The body includes at least one air filter that runs along the length of at least a portion of the body. The air filter dividing the body into a first plenum and a second plenum. The air track also includes a hood covering at least a portion of the top surface. The air track further includes a stopper assembly that arrests the motion of a disk. The stopper assembly includes a disk detector that senses the presence of the disk on the air track.

Description:
FIELD OF INVENTION  
         [0001]    The invention relates to the manufacture of magnetic and optical recording media and in particular to a method and an apparatus for transporting small form factor disks from one processing station to another.  
         BACKGROUND  
         [0002]    In semiconductor processing, semiconductor wafers are transferred from one processing station to another. Semiconductor wafers have been transported by means of an air track. As illustrated in prior art FIG. 1, an air track  11  has a generally flat surface  12  for supporting a generally circular disc  13 . A manifold  14  in the form of a drilled opening extends along the centerline of air track  11  for receiving air under pressure to be discharged via the uniformly spaced outlets  16  at an angle having a vectorial component extending in the direction in which it is desired to transport disc  13 . The side edges  17  serve to guide disc  13  along a predetermined path.  
           [0003]    In some systems, it is desirable to guide the paths of disc  13  without mechanical constraints such as side edges  17  because direct contact with mechanical constraints may damage and contaminate disc  13 . Contamination to disc  13  can also come from the air used to support disc  13  on air track  11 . As illustrated in prior art FIG. 2, the upward flow of air  18  passes around the bottom surface of disc  13  and swirls downwardly onto the top surface of the disc. Any contaminants which may have been entrained in air  18  can therefore attach to the top and bottom surfaces of disc  13 .  
           [0004]    Thus, what is needed is an air track system optimized for transport of magnetic recording media that minimizes contact with mechanical constraints and reduces contamination from the air that supports the disk.  
         SUMMARY  
         [0005]    In one embodiment of the invention, an air track includes a body having a concave top surface. In another embodiment of the invention, an air track includes a body having an air filter that divides the body into a first plenum above a second plenum. The air filter runs along the length of at least a portion of the body. In yet another embodiment, an air track includes a hood that runs above at least a portion of a top surface of a body. In yet another embodiment, an air track includes a body having a top surface with a notch located approximately at the center of the top surface. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 shows a perspective view of an air track in the prior art.  
         [0007]    [0007]FIG. 2 shows an air flow diagram of the air track of FIG. 1 in the prior art.  
         [0008]    [0008]FIGS. 3A, 3B,  3 C, and  3 D show various views of an air track in accordance with one embodiment of the invention.  
         [0009]    [0009]FIGS. 4A, 4B,  4 C, and  4 D show various views of an air track in accordance with another embodiment of the invention.  
         [0010]    [0010]FIGS. 5A, 5B,  5 C,  5 D, and  5 E show various views of an air track in accordance with yet another embodiment of the invention.  
         [0011]    [0011]FIGS. 6A, 6B,  6 C, and  6 D show various views of a stopper assembly in accordance with one embodiment of the invention.  
         [0012]    [0012]FIGS. 7A, 7B, and  7 C show various views of a stopper assembly in accordance with another embodiment of the invention.  
         [0013]    [0013]FIGS. 8A, 8B,  8 C, and  8 D show various views of a stopper assembly in accordance with yet another embodiment of the invention.  
         [0014]    [0014]FIG. 9 shows a side view of an air stopper assembly in accordance with one embodiment of the invention.  
         [0015]    [0015]FIG. 10 shows a front view of a stopper assembly similar to the stopper of FIG. 6 in accordance with another embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0016]    FIGS.  3 A- 3 D illustrate an air track  300  in accordance with one embodiment of the invention. Air track  300  forms part of an air track conveyor system that transports magnetic or optical disks from one processing station to another during the manufacturing process. Processing stations are designed to receive disks from and unload disks onto air track  300 . For example, air track  300  is used to transport disks from a load station to a lube station. For more details regarding the load station and the lube station, the reader is directed to respective U.S. application Ser. Nos. ______ and ______, which are filed herewith, having the same assignee and are incorporated herein by reference.  
         [0017]    Air track  300  includes a body  301  defining a plenum  302 . Air enters body  301  through an air inlet  314  (shown in FIG. 3A). Body  301  has a top surface  304 . Top surface  304  is concave along the length of air track  300 . Top surface  304  has a radius R (shown in FIG. 3A). Top surface  304  has air outlets  308  that support a disk  310  transported along air track  300 . Air outlets  308  has a diameter of, e.g., 0.03 in. Any pattern of air outlets  308  can be used. Preferably, air outlets  308  are positioned on either side of inner diameter  312  of disk  310  to provide air against the bottom surface of disk  310 . Exemplary dimensions of body  301  for transporting a disk of 27.4 mm diameter are provided below.  
                               TABLE 1                                       D1   0.2   in.           D2   0.35   in.           D3   0.4   in.           Ø   0.03           H   1.5   in.           W   1.5   in.           T   0.125   in.           R   100   mm                      
 
         [0018]    Depending on the implementation, body  301  may be constructed from a single or multiple pieces of material. Although a straight air track  300  is illustrated in FIGS.  3 A- 3 D, a curved air track  300  can constructed in the same manner.  
         [0019]    The curvature of top surface  304  guides disk  310  along a predetermined path on air track  300 . As FIG. 3A illustrates, air outlets  308  located near the sides of air track  300  are closer to disk  310  than air outlets  308  located near the center of air track  300 . Thus, air outlets  308  located near the sides exert more force on disk  310  than air outlets  308  located near the center. The balance of these forces centers disk  310  along air track  300 . Accordingly, physical restraints are not needed to guide disk  310  along a predetermined path on air track  300 .  
         [0020]    Air track  300  can be positioned at an angle relative to its length to allow gravity to move disk  310  along a predetermined path on air track  300 . For example, air track  300  can be tilted  0  to  10  degrees relative to its length. Alternatively, air outlets  308  can be angled to push disk  310  along a predetermined path on air track  300 .  
         [0021]    FIGS.  4 A- 4 D illustrate an air track  400  in accordance with another embodiment of the invention. Air track  400  includes a body  401  and at least one air filter  404  that runs along the length of at least a portion of body  401 . Air filter  404  is, e.g., a 0.1 micron filter. Air filter  404  divides body  401  into top plenum  302  and bottom plenum  402 . Body  401  has concave top surface  304  and air outlets  308 . Body  401  may be constructed from a single or multiple pieces of material. Exemplary dimensions of body  401  are provided below.  
                               TABLE 2                                       D1   0.2   in.           D2   0.35   in.           D3   0.4   in.           Ø   0.03           H   3   in.           W   1.5   in.           T   0.125   in.           R   100   mm                      
 
         [0022]    Air enters body  401  through air inlet  414 . Air then travels from plenum  402  to plenum  302  through filter  404 . Air then exit plenum  302  through air outlets  308 . Depending on the implementation, a baffle  406  can be placed in plenum  402  to equalize the pressure therein. Clamps  408  and  410  support filter  404  between against the side walls of body  401 . Depending on the implementation, clamps  408  and  410  may be formed as part of body  401 , or as separate pieces attached to body  401 . Filter  404 , clamps  408  and  410  all run along the length of at least a portion of body  401 . Gaskets  412  are fitted between clamps  408  and filter  404  to ensure only filtered air travels from plenum  402  to  302 . Gaskets  412  are, e.g., a Viton® fluoroelastomer gaskets.  
         [0023]    Filter  404  removes contaminants from the air so disk  310  is not contaminated by the air. Filter  404  also causes a large pressure drop from plenum  402  to plenum  302 . The large pressure drop creates uniform air pressure within plenum  302 . The uniform pressure within plenum  302  ensures that the air exits evenly through air outlets  308  so that disk  310  is supported at a consistent height and no turbulent air flow exists.  
         [0024]    A protective hood  416  is positioned over top surface  304 . Hood  416  runs along the length of at least a portion of body  401 . Hood  416  forms an enclosure  418  over top surface  304  where air escapes from enclosure  418  through spaces  420 . Hood  416  prevents contaminants from collecting atop disk  310  as it travels along air track  300 . Furthermore, the air from air outlets  308  creates positive pressure within enclosure  418  to prevent contaminants from entering and contaminating disk  310  through spaces  420 .  
         [0025]    FIGS.  5 A- 5 E illustrate air track  500  in yet another embodiment of the invention. As can be seen, body  501  has a top surface  504  that is flat instead of concave. Body  501  also includes edges (walls)  502  that guide disk  310  along air track  500 . In some implementations, a portion of top surface  504  is removed or altered. For example, top surface  504  includes a notch  524  that runs along the length of at least a portion of top surface  504 . A flat top surface  504  may be less expensive to produce than a concave top surface  304  because it requires less complicated machining. However, disk  310  may be contaminated from contact with edges  502 . In other aspects, air track  500  is same as air track  400  of FIGS.  4 A- 4 D. Exemplary dimensions of body  501  are provided below.  
                               TABLE 3                                       D1   0.2   in.           D2   0.35   in.           D3   0.4   in.           D4   0.0625   in.           D5   0.125   in.           D6   1.2   in.           D7   0.175   in.           D8   0.01   in.           D9   0.31   in.           Ø   0.03           H   3   in.           W   1.5   in.           T   0.125   in.                      
 
         [0026]    A portion of air track  500  can be positioned at an angle relative to its width so disk  310  rests against one of edges  502  (e.g., a “reference edge”) while it is stationary or traveling along air track  500 . Placing disk  310  against a reference edge allows disk  310  to be consistent positioned in a predetermined location at a processing station. Alternatively, air outlets  308  can be angled to push disk  310  along air track  500  and/or against the reference edge.  
         [0027]    FIGS.  6 A- 6 D illustrate a stopper assembly  600  in one embodiment of the invention. Stopper  600  includes an arm  602  pivotally mounted to a frame  604  through a flexure hinge  606 . Arm  602  includes a vertical section  605  to contact disk  310  and a horizontal section  603  used to control movement of arm  602 . Horizontal section  603  rests atop a bore  608  of frame  604 . A ball bearing  610  is placed within bore  608 . An electric solenoid  612  (e.g., an actuator) is mounted to frame  604  below bore  608  so ball bearing  610  rests against the plunger (not shown) of solenoid  612 . Depending on the implementation, solenoid  612  can be activated or deactivated to push ball bearing  610  against horizontal section  603  to raise vertical section  605  so disk  310  can pass stopper  600  on air track  601 . Otherwise vertical section  605  rests on or near a top surface  625  of air track  601  to arrest the motion of disk  310  (e.g., to buffer disk  310 ). Contacts between vertical section  605  and top surface  625  can generate particles that contaminate disk  310 . Thus, it is preferred to rest vertical section  605  near top surface  625  without contacting top surface  625 . In one embodiment, a portion of vertical section  605  rests above a notch  617  on top surface  625 .  
         [0028]    Stopper  600  is mounted to the side of an air track  601  (representing any of air tracks  300 ,  400 , and  500 ) at a predetermined location (“stopper position”). Air track  601  includes a C-shaped slotted channel  652  where stopper  600  can be mounted. Nuts  654  (shown in FIGS. 6A, 6C, and  6 D) are inserted into channel  652 . Bolts  656  (shown in FIGS. 6A, 6C, and  6 D) are passed through bores  658  (shown in FIG. 6D) on frame  604  to secure frame stopper  600  to channel  652 .  
         [0029]    In one embodiment, stopper  600  includes a disk detector  650 . Disk detector  650  includes a light source  616  (e.g., a laser), a photo-detector  618 , a frame  620 , and a frame  622 . Light source  616  and photo-detector  618  are mounted on frame  620 . Frame  620  is pivotally mounted to frame  622  via a screw  621  (shown in FIGS. 6C and 6D). Frame  622  includes a slot  624  that allows screws  623  to secure frame  622  to frame  604  at various heights. Light source  616  shines a light toward a corner of a slot  617  (representing any slot or notch) on air track  601 . Photo-detector  618  detects the light reflected from the corner of notch  617  when disk  310  is not in the path of the light. Conversely, photo-detector  618  detects a lower amount of light when disk  310  is in the path of the light because disk  310  reflects the light to another direction. The path of the light can be aligned by changing the angle at which frame  620  is mounted to frame  622 , and the height at which frame  622  is mounted to frame  604 .  
         [0030]    Depending on the implementation, arm  602  can be raised or lowered when disk  310  is detected. For example, arm  602  can be lowered to stop disk  310  when a processing station is not ready to process disk  310 . Arm  602  can also be lowered to arrest the motion of disk  310  so it can be removed from air track  601  for processing. The stopper assembly  600  advantageously arrests the motion of disk  310  without changing the height of disk  310  on air track  601 .  
         [0031]    [0031]FIG. 10 illustrates a stopper assembly  1000  in one embodiment. Stopper assembly  1000  is the same as stopper assembly  600  except that photo-detector  618  is moved to an opposing side of air track  601  and air track  601  does not have a slot  617 . The same structure used to mount light source  616  can be used to mount photo-detector  618  on the opposing side of air track  601 . For example, photo-detector  618  is mounted on a frame  620 A. Frame  620 A is pivotally mounted to a frame  622 A. Frame  622 A includes a slot  624 A that allows screws  623 A to secure frame  622 A to frame  604 A at various heights. Frame  622 A is mounted to air track  601 .  
         [0032]    Light source  616  shines a light toward top surface  625  of air track  601 . Light source  616  and photo-detector  618  are aligned such that top surface  625  reflects the light to photo-detector  618  when disk  310  is not in the path of the light. In this implementation, photo-detector  618  detects light when disk  310  is not present. Alternatively, light source  616  and photo-detector  618  are aligned such that top surface of disk  310  reflects the light to photo-detector  618  when disk  310  is in the path of the light. In this implementation, photo-detector  618  detects light when disk  310  is present. Stopper  1000  can work equally well for an air track  601  with a concave top surface  625 .  
         [0033]    FIGS.  7 A- 7 C illustrate a stopper assembly  700  in one embodiment of the invention. Stopper  700  is mounted to the side of an air track  701  (representing any of air tracks  300 ,  400 , and  500 ). Stopper  700  includes an L-shaped frame  702  with a drive motor  704  and drive rollers  706  and  708  mounted thereon. Drive motor  704  rotates drive rollers  706  and  708  via a belt  710 . Alternatively, drive motor  704  rotates drive rollers  706  and  708  via a set of gears or any other conventional drive mechanism. A linear stage  712  moves frame  702  down to arrest the motion of disk  310  on air track  701 . Conversely, stage  712  moves frame  702  up to allow passage of disk  310 . Although not shown, the disk detector of FIGS.  6 A- 6 D can be mounted to air track  701  upstream from stopper  700  to detect the presence of disk  310 .  
         [0034]    Once stopper  700  has stopped disk  310 , drive motor  704  can drive driver rollers  706  and  708  to rotate disk  310  so it can be processed and/or inspected in-situ. For example, a processing equipment can perform optical inspection, laser texturing, spin rinse drying, and spin coating on disk  310  without removing it from air track  701 . In one implementation, disk  310  has a bar code that can be read when disk  310  is rotated by stopper  700 . Like stopper  600 , stopper  700  advantageously arrests the motion of disk  310  without changing the height of disk  310  on air track  701 .  
         [0035]    [0035]FIGS. 8A and 8B illustrate a stopper assembly  800  in one embodiment of the invention. Stopper  800  includes a top surface  804  and a bottom surface  806  made of a flexible material such as thin spring steel. Top surface  804  can be flat or concave as described above. Top surface  804  and bottom surface  806  are coupled by cross-members  807 . An actuator  802  is connected to bottom surface  806 . Actuator  802  is, e.g., a pneumatic piston. As FIG. 8B shows, the actuator pulls a portion of bottom surface  804  and top surface  806  downwards while sides  810  remain stationary when it is desired to stop disk  310 . Disk  310  then comes to rest at the lowered portion of top surface  804  from the forces of gravity. Disk  310  can continue along its path when actuator  802  releases the lowered portion of top surface  804 .  
         [0036]    [0036]FIG. 8C shows that top surface  804  and bottom surface  806  can slide against sides  810  when lowered. Alternatively, FIG. 8D shows that air gaps  808  can be provided between sides  810  and surfaces  804  and  806  so that surfaces  804  and  806  are lowered without sliding against sides  810 . Such a configuration will have a predictable leak from stopper  800  but will not generate particles that can contaminate disk  310  from surfaces  804  and  806  sliding against sides  810  FIG. 9 illustrates a stopper assembly  900  in one embodiment of the invention. In this embodiment, an air nozzle  902  is placed above air track  901  (representing any of air tracks  300 ,  400 , and  500 ) to supply air  904  onto the top surface of air track  901  to arrest the motion of disk  310 . Air  904  pushes against disk  310  so disk  310  cannot travel beyond air nozzle  902 .  
         [0037]    Although the invention has been described with reference to particular embodiments, the description is only of examples and should not be taken as a limitation. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as defined by the following claims.