Abstract:
The invention includes mainly a machine base, a carrier, a sliding control mechanism, a latch mechanism, a horizontal shifting mechanism, and a lifting mechanism. The FOUP (front-opening unified pod) is put on the carrier and latched by a locking plate of the latch at an accurate position. The carrier moves forwardly to tightly engage the FOUP to a gate on an access at a backboard of the machine base, and thus a cover of the FOUP is opened by a headstock gear at the back of the gate then carried backwardly away from the FOUP by the horizontal shifting mechanism and lowered by the lifting mechanism. Reversely, the cover is closed on the FOUP. As such, the cover is loaded and opened automatically, as well as in closed, which can be a part of automation and prevents wafers from contamination.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a FOUP (front-opening unified pod) auto-loading structure and, more particularly, to a FOUP auto-loading structure, which is suitable for use in the load port of a wafer manufacturing equipment to automatically close/open the cover of a FOUP. 
   2. Brief Description of the Prior Art 
   Current wafer process puts wafers in a unified pod such that the purity of the small inner of the unified pod is well controlled. Because the purity of the small inner of the unified pod is well controlled, the purity of the external cleanroom is less critical. This saves much clean expenditure on the wafer manufacturing equipment. However, external dust or human body dust may be carried in the manufacturing equipment when opening the cover of the unified pod manually, so as to bring about contamination to wafers. 
   SUMMARY OF THE INVENTION 
   The invention has been accomplished to provide a FOUP auto-loading structure, which eliminates the cited problem. It is an object of the present invention to provide a FOUP auto-loading  structure, which automatically loads the FOUP for opening or closing its cover, thereby preventing wafers from contamination. It is another object of the present invention to provide a FOUP auto-loading structure, which can be a part of an full-automated wafer manufacturing process. 
   To achieve the objects and according to one aspect of the present invention, the FOUP auto-loading structure comprises a machine base, a carrier, a sliding control mechanism, a latch, a horizontal shifting mechanism and a lifting mechanism. The machine base has a backboard with an upper access, a table against middle of the backboard, and a base against bottom of the backboard. The carrier supported by the table is adapted to carry a FOUP. The carrier has an elongated opening close by the backboard. The sliding control mechanism is mounted on the table to support the carrier and control it toward or away from the access. The latch below the carrier has, a rail fixedly fastened on bottom thereof, a threaded rod disposed in parallel to the rail of the latch, a sliding pad threaded onto the threaded rod of the latch and adapted to slide along the rail of the latch, a motor adapted to rotate the threaded rod of the latch clockwise/counter-clockwise so as to make the sliding pad slide forwardly and backwardly, and a locking plate fixedly mounted on the sliding pad of the latch and adapted to latch the FOUP on the  carrier by inserting through the elongated opening of the carrier and moving with the sliding pad of the latch to a retaining portion of the carrier. The horizontal shifting mechanism has a rail fixedly mounted on the base of the machine base, a horizontal threaded rod disposed in parallel to the rail of the horizontal shifting mechanism, a platform threaded onto the threaded rod of the horizontal shifting mechanism, and a motor to drive and control the platform to move horizontally along the rail of the horizontal shifting mechanism as rotating the threaded rod of the horizontal shifting mechanism clockwise/counter-clockwise, thereby moving the platform horizontally along the rail of the horizontal shifting mechanism toward/away from the backboard of the machine base. The lifting mechanism has a motor and a threaded rod and slider set vertically mounted on the platform of the horizontal shifting mechanism. The threaded rod and slider set has a vertical rail, a threaded rod longitudinally mounted in the vertical rail, a sliding pad threaded onto the threaded rod of the lifting mechanism and moved along the vertical rail upon the rotation of the threaded rod of the lifting mechanism. According to another aspect of the present invention, the FOUP auto-loading structure further comprises a headstock gear moved with the sliding pad of the lifting mechanism and controlled to close/open the cover of the FOUP on the carrier. According to still another  aspect of the present invention, the headstock gear has a gate, two racks, two support arms and a driving unit. The gate moves in and out of the access of the backboard of the machine base. The two racks are fixedly fastened on a surface of the gate that does not contact the FOUP. The two support arms are respectively extended from the racks and connected to the sliding pad of the lifting mechanism. The driving unit mounted above the two racks and controlled to close/open the cover of the FOUP on the carrier has a transmission shaft, a motor controlled to rotate the transmission shaft, two rotary bolts respectively coupled to the transmission shaft and inserted through the through holes of said gate for engaging into the locking holes and rotating with the transmission shaft to thus close/open the cover of the FOUP on the carrier. According to still another aspect of the present invention, the carrier has a round opening for inserting through a locking bolt engaging with a locking bolt control motor to thus lock the FOUP on the carrier. 
   Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a FOUP auto-loading  structure according to the present invention. 
       FIG. 2A  is an exploded view of a part of the present invention, showing the arrangement of the latch, the locking bolt and locking bolt control motor, the sliding control mechanism, and the table. 
       FIG. 2B  is a sectional view of a part of the present invention, showing the arrangement of the latch, the locking bolt and locking bolt control motor, and the sliding control mechanism between the carrier and the table. 
       FIG. 3  is a perspective view of the lower part of the present invention, showing the arrangement of the horizontal shifting mechanism and the lifting mechanism. 
       FIG. 4  is a perspective backside view of a part of the present invention, showing the arrangement of the lifting mechanism, the horizontal shifting mechanism, and the headstock gear. 
       FIG. 5  is a perspective view in an enlarged scale of the upper part of  FIG. 4 . 
       FIG. 6  is a schematic cross-section showing the operation of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , a typical FOUP (front-opening unified pod)  8  and an inventive FOUP auto-loading structure are shown,  wherein the inventive structure is applied for automatically loading a cover  82  of the FOUP  8  and opening/closing the cover. In addition to the cover  82 , the FOUP  8  also includes an front-opening  81  closed by the cover  82  and a bottom plate  83 . The cover  82  has two locking holes  821  and  821 ′. The bottom plate  83  has a positioning portion  831  at the center and a retaining portion  832  at a side close by the cover. 
   Referring to  FIGS. 1 and 2 , the inventive FOUP auto-loading structure includes a machine base  1 , a carrier  2 , a sliding control mechanism  21 , a latch  4 , a horizontal shifting mechanism  5  and a lifting mechanism  6 . The machine base, referenced by  1 , has a backboard  11  fixedly disposed against load port of the manufacturing equipment  9  a table  12  is transversely disposed against middle of the backboard  11 , a base  13  fixedly disposed against bottom of the backboard  11 , an access  110  disposed at upper of the backboard  11 , two parallel sliding slots  111  and  112  longitudinally disposed at the backboard  11  and below the table  12  (see also  FIG. 4 ), and a gasket  113  fastened on edges of the access  110  facing the FOUP  8  and adapted to accommodate the front-opening  81  of the FOUP  8 . 
   The carrier, referenced by  2 , has three upright positioning rods  201  corresponding to three positioning grooves  833  at the bottom plate  83  of the FOUP  8  for positioning the FOUP  8  on the  carrier  2 , two first upright detecting pins  202  and  202 ′ corresponding to two round recesses  834  and  834 ′ at the bottom plate  83  of the FOUP  8  for detecting a frontend manufacturing process or backend manufacturing process, two second upright detecting pins  203  and  203 ′ corresponding to detecting recesses  835  and  835 ′ at the bottom plate  83  of the FOUP  8  for detecting if a type of the FOUP  8  is a 13-piece or 25-piece, and a third upright detecting pin  206  (see  FIG. 2B ) to determine if the FOUP  8  is positioned correctly. If the FOUP  8  does not match the upright detecting pins  201 ,  202  and  203 ′, the bottom plate  83  is tilted and cannot press down the third upright detecting  206 . In this case, it means that the FOUP  8  is not correctly positioned. The carrier  2  further has a round opening  204  to accommodate a locking bolt  3  (described later) and an elongated opening  205  to accommodate a locking plate  45  (described later). 
     FIG. 2A  shows the carrier  2  supported by a sliding control mechanism  21  on the table  12 . The sliding control mechanism  21  has two parallel rails  22  and  22 ′ fixedly mounted on the table  12 , limit switches  221  and  221 ′ respectively disposed at two ends of rail  22 , two sliding pads  23  and  23 ′ fixedly mounted respectively on the parallel rails  22  and  22 ′ of the carrier  2  for movement along the rails  22  and  22 ′, a threaded rod  25  fixedly mounted on the table  12  below the sliding pad  23  close by the limit switches   221  and  221 ′, and a reversible motor  24  adapted to rotate the threaded rod  25  clockwise/counter-clockwise. The sliding pad  23  is threaded onto the threaded rod  25 . When starting the reversible motor  24  to rotate the threaded rod  25  clockwise or counter-clockwise, the carrier  2  is moved with the sliding pads  23  and  23 ′ along the rails  22  and  22 ′ toward or away from the access  110 . 
   Referring to  FIG. 2B  and  FIG. 2A  again, a locking bolt control motor  31  and a latch  4  are fixedly fastened to the bottom of the carrier  2 . A locking bolt  3  is a T shape with a stem coupling to the locking bolt control motor  31  through limit switches  311 ,  311 ′ and a head inserting through the round opening  204  of the carrier  2  into the positioning portion  831  of the bottom plate  83  of the FOUP  8 . After inserting the locking bolt  3  into the positioning portion  831  of the bottom plate  83  of the FOUP  8 , the locking bolt control motor  31  rotates the locking bolt  3  by 90° angle to lock the FOUP  8 . The limit switches  311  and  311 ′ control the motor  31  to rotate clockwise or counterclockwise 90°, so as to move the locking bolt  3  between the lock and the unlock positions. 
   The latch  4  has a rail  41 , a sliding pad  42 , a motor  43 , a threaded rod  44 , the locking plate  45 , limit switches  411 ,  411 ′ and rollers  46 . The rail  41  is fixedly fastened to a bottom of the latch  4  in parallel to the threaded rod  44  on which a slide  42  is  disposed to move along the rail  41  with rotation of the threaded rod  44 . The limit switches  411  and  411 ′ are respectively mounted on two ends of the rail  41 , and a motor  43  is controlled to rotate the threaded rod  44 . The locking plate  45  is fixedly mounted on the sliding pad  42  and inserted through the elongated opening  205  of the carrier  2  to latch the retaining portion  832  of the bottom plate  83  of the FOUP  8 . Clockwise/counter-clockwise rotation of the motor  43  drives the locking plate  45  to be moved forwardly and backwardly with the sliding pad  42 , and therefore the locking plate  45  is pressed on or released from the retaining portion  832  of the bottom plate  83  of the FOUP  8 . Further, the plastic rollers  46  are bilaterally disposed at top of the locking plate  45  in order to prevent the retaining portion  832  from being damaged as the retaining portion  832  presses down on the locking plate  45  and eliminates dust caused by friction between the retaining portion  832  and the locking plate  45 . 
   Referring to  FIG. 3 , a horizontal shifting mechanism  5  and a lifting mechanism  6  are respectively installed over the base  13  of the machine base  1 . The horizontal shifting mechanism  5  has two parallel rails  51  and  51 ′ disposed respectively on the base  13  of the machine base  1  and extended perpendicular to the backboard  11 , two limit switches  511  and  511 ′ respectively disposed at two ends of rail  51 , a horizontal threaded rod  53  disposed in parallel  above the rails  51  and  51 ′, a platform  52  threaded by the threaded rod  53  and movably supported by the rails  51  and  51 ′, and a motor  54  to rotate the threaded rod  53  clockwise/counter-clockwise so as to move the platform  52  forwardly/backwardly along the rails  51  and  51 ′ relative to the backboard  11 . The lifting mechanism  6  has a threaded rod and slider set  61  and an upright motor  65  mounted on the platform  52  of the horizontal shifting mechanism  5 . The threaded rod and slider set  61  has a vertical rail  62  of U-shaped cross section having an outward opening, two guide rods  621  connecting the vertical rail  62  to the backboard  11  by inserting through respective guide holes  114  of the backboard  11  for guiding the vertical rail  62  to horizontally move with the platform  52 , a threaded rod  64  vertically mounted in the vertical rail  62 , a sliding pad  63  threaded onto the threaded rod  64  and moved along the vertical rail  62  as rotating the threaded rod  64 , and a limit switch  622  mounted in the vertical rail  62  to reduce an impact of the sliding pad  63 . The motor  65  rotates the threaded rod  64  clockwise/counter-clockwise to thus move the sliding pad  63  upwardly/downwardly along the vertical rail  62 . 
   Referring to  FIGS. 4 and 5  and  FIG. 1  again, a headstock gear  7  is disposed on a backside of the backboard  11 . The headstock gear  7  has a gate  71  fitting the access  110  of the backboard  11  and a gasket  712  fastened on edges of the gate  71  at  a surface not contacting the FOUP  8  and adapted to accommodate the cover  82  of the FOUP  8 . The gate  71  has two front positioning pins  713  respectively engaged to the positioning recesses  822  and  822 ′ on the cover  82  of the FOUP  8  and to prevent the FOUP  8  from displacement and two through holes  711  corresponding to the locking holes  821  and  821 ′ of the cover  82  of the FOUP  8 . The headstock gear  7  also has two parallel racks  72  and  72 ′ fixedly fastened on a back of the gate  71 , two support arms  73  and  73 ′ respectively disposed over the racks  72  and  72 ′ below the gate  71  in order to insert through the sliding slots  111  and  112  of the backboard  11  and fixedly connect to the sliding pad  63  of the threaded rod and slider set  61  of the lifting mechanism  6  for enabling the gate  71  to be moved with the horizontal shifting mechanism  5  and the lifting mechanism  6 , and a driving unit  74  mounted on the back of the gate  71  and controlled to close/open the cover  82  of the FOUP  8 . The driving unit  74  has a transmission shaft  76 , a motor  75  controlled to rotate the transmission shaft  76 , two rotary bolts  77  and  77 ′ respectively coupled to the transmission shaft  76  and inserted through the through holes  711  of the gate  71  for engaging into the locking holes  821  and  821 ′ of the cover  82  of the FOUP  8  to open the cover  82  from the opening  81  of the FOUP  8 . Further, at least one, for example, two detectors  78  are disposed on top of the gate  71 .  After opening the cover  82 , the detectors  78  are moved with the gate  71  up and down relative to the FOUP  8  to detect wafer number and position in the FOUP  8 . In addition, a detector  79  is mounted on the back of the backboard  11  above the access  110  to detect protrusive wafers in the FOUP  8 , so as to prevent wafers from damage when closing/opening of the cover  82 . 
   As stated above, when the FOUP  8  is carried to the carrier  2  by hand or an automatic truck, positioning of the FOUP  8  is detected by the detecting pins  202 ,  203  and  206 , and then the detecting pin  206  is pressed down to start the motor  31  to rotate the locking bolt  3  by 90°, and therefore the locking bolt  31  is engaged with the positioning portion  831  on the bottom plate  83  of the FOUP  8 . At the same time, the motor  43  of the latch  4  rotates the threaded rod  44  to move the locking plate  45  with the sliding pad  42  and engage with the retaining portion  831  of the bottom plate  83  of the FOUP  8 . This double-locking effect can ensure accurately forward movement of the FOUP  8 . The sliding control mechanism  21  then moves the carrier  2  and the FOUP  8  forwardly, causing the opening  81  of the FOUP  8  to be forced into close contact with the gasket  113  of the access  110 . Therefore, when the motor  75  of the driving unit  74  rotates the rotary bolts  77  and  77 ′ for opening the cover  82 , the FOUP  8  is maintained free from contamination. Thereafter, the horizontal shifting mechanism  5   moves the cover  82  horizontally and backwardly, and then the lifting mechanism  6  lowers the cover  82  for allowing the internal mechanical arm of the manufacturing equipment  9  to carry wafers from the FOUP  8 . On the contrary, when closing the cover  82  on the FOUP  8 , the procedure is repeated reversely. Therefore, the FOUP  8  can be automatically opened and closed in the manufacturing equipment  9  without contamination. 
   Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.