Wafer transfer apparatus, wafer gripper, and wafer gripper guide used in such wafer transfer apparatus

Abstract

In a wafer transfer apparatus for transferring a semiconductor wafer, a wafer gripper is composed of a pair of gripper arms, and a gripper guide is attached to each of the gripper arms. A driving unit operates the gripper arms such that the semiconductor wafer is releasably gripped with the gripper guides of the gripper arms. Each of the gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and the groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.

1 . A wafer transfer apparatus for transferring a semiconductor wafer, which comprises: 
 a wafer gripper composed of first and second gripper arms which are pivotally joined to each other;    a first gripper guide attached to said first gripper arms;    a second gripper guide attached to said second gripper arms; and    a driving unit that operates said first and second grippers such that the semiconductor wafer is releasably gripped with said first and second gripper guides of said first and second gripper arms,    wherein each of said first and second gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and said groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.    
   
   
       2 . The wafer transfer apparatus as set forth in  claim 1 , wherein an end portion of said first gripper arm is formed as a curved end portion to which said first gripper guide is attached, and an end portion of said second gripper arm is formed as a semi-circularly curved end portion to which said second gripper guide is attached.  
   
   
       3 . The wafer transfer apparatus as set forth in  claim 2 , wherein said semi-circularly curved end portion terminates with an arch extension which is detachably connected thereto, and said second gripper guide is attached to said arch extension.  
   
   
       4 . The wafer transfer apparatus as set forth in  claim 3 , wherein said arch extension has a third gripper guide attached thereto.  
   
   
       5 . The wafer transfer apparatus as set forth in  claim 1 , wherein said generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and said ridge element is protruded from an outer side edge defining one of the tapered side wall faces.  
   
   
       6 . The wafer transfer apparatus as set forth in  claim 5 , wherein said bottom wall face is configured as an arch bottom wall face having substantially a same curvature as that of a peripheral edge of the semiconductor wafer.  
   
   
       7 . The wafer transfer apparatus as set forth in  claim 6 , wherein said arch bottom wall face has a width which is substantially equivalent to a thickness of the semiconductor wafer.  
   
   
       8 . A wafer gripper for gripping a semiconductor wafer, which comprises: 
 first and second gripper arms which are pivotally joined to each other;    a first gripper guide attached to said first gripper arms; and    a second gripper guide attached to said second gripper arm,    wherein each of said first and second gripper guides is formed with a groove for receiving a peripheral edge of the semiconductor wafer, and said groove is configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof.    
   
   
       9 . The wafer gripper as set forth in  claim 8 , wherein an end portion of said first gripper arm is formed as a curved end portion to which said first gripper guide is attached, and an end portion of said second gripper arm is formed as a semi-circularly curved end portion to which said second gripper guide is attached.  
   
   
       10 . The wafer gripper as set forth in  claim 9 , wherein said semi-circularly curved end portion terminates with an arch extension which is detachably connected thereto, and said second gripper guide is attached to said arch extension.  
   
   
       11 . The wafer gripper as set forth in  claim 10 , wherein said arch extension has a third gripper guide attached thereto.  
   
   
       12 . The wafer gripper as set forth in  claim 8 , wherein said generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and said ridge element is protruded from an outer side edge defining one of the tapered side wall faces.  
   
   
       13 . The wafer gripper as set forth in  claim 12 , wherein said bottom wall face is configured as an arch bottom wall face having substantially a same curvature as that of a peripheral edge of the semiconductor wafer.  
   
   
       14 . The wafer gripper as set forth in  claim 13 , wherein said arch bottom wall face has a width which is substantially equivalent to a thickness of the semiconductor wafer.  
   
   
       15 . A wafer gripper guide comprising: 
 a body portion which is formed with a groove for receiving a peripheral edge of a semiconductor wafer, said groove being configured as a generally V-shaped groove featuring a ridge element protruded from an outer side edge thereof; and    an attachment portion extended from said body portion.    
   
   
       16 . The wafer gripper guide as set forth in  claim 15 , wherein said generally V-shaped groove is defined by a bottom wall face, and a pair of tapered side wall faces extending from the lateral sides of the bottom wall face, and said ridge element is protruded from an outer side edge defining one of the tapered side wall faces.  
   
   
       17 . The wafer gripper guide as set forth in  claim 16 , wherein said bottom wall face is configured as an arch bottom wall face having substantially a same curvature as that of a peripheral edge of the semiconductor wafer.  
   
   
       18 . The wafer gripper guide as set forth in  claim 17 , wherein said arch bottom wall face has a width which is substantially equivalent to a thickness of the semiconductor wafer.  
   
   
       19 . The wafer gripper guide as set forth in  claim 15 , wherein said ridge element has a height of at most 0.5 mm.