Transferring device

Abstract

A transferring device including a transferring device main body; a transferring arm which is coupled with the transferring device main body to transfer a workpiece; and a supporting hand which has a plurality of engaging parts coupled with the transferring arm and forming a predetermined angle therebetween to support the workpiece based on a force applied to the workpiece according to varying rotation speeds of the transferring arm. Thus, a transferring device can stably support a workpiece.

1 . A transferring device, comprising:
 a transferring device main body;   a transferring arm that couples with the transferring device main body to transfer a workpiece; and   a supporting hand which has a plurality of engaging parts coupled with the transferring arm and forms a predetermined angle therebetween to support the workpiece based on a force applied to the workpiece according to varying rotation speeds of the transferring arm.   
   
   
       2 . The transferring device according to  claim 1 , wherein the supporting hand comprises a coupling part which couples with the transferring arm and a plurality of blades which extend from the coupling part and are spaced apart from each other. 
   
   
       3 . The transferring device according to  claim 2 , wherein the engaging part comprises a first engaging part formed on the coupling part, and a second engaging part formed on each of the blades, and the angle between the engaging parts is defined by an angle between the second engaging parts with respect to the center of the workpiece. 
   
   
       4 . The transferring device according to  claim 3 , wherein the angle between the second engaging parts is determined on the basis of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to the varying rotation speeds of the transferring arm. 
   
   
       5 . The transferring device according to  claim 4 , wherein the engaging parts is provided in a position where the resultant force of the centrifugal force and the rotation inertial force becomes the maximum. 
   
   
       6 . The transferring device according to  claim 3 , wherein the engaging parts are depressed from a planar surface of the supporting hand by a predetermined depth. 
   
   
       7 . The transferring device according to  claim 3 , wherein the engaging parts form a larger diameter than the workpiece. 
   
   
       8 . The transferring device according to  claim 3 , wherein the supporting hand comprises a spacer which is depressed inside the engaging parts. 
   
   
       9 . The transferring device according to  claim 8 , wherein the spacer has a smaller diameter than the workpiece. 
   
   
       10 . The transferring device according to  claim 3 , wherein the supporting hand comprises one of stainless steel and ceramic. 
   
   
       11 . The transferring device according to  claim 3 , wherein the supporting hand comprises an inclination part formed along edges of the engaging parts. 
   
   
       12 . The transferring device according to  claim 1 , wherein the workpiece comprises a wafer. 
   
   
       13 . A transferring device to transfer a workpiece, comprising:
 a body;   a transferring arm to extend away from and contract toward the body; and   a supporting hand to connect with the transferring arm, the supporting hand comprising:
 a coupling part to engage with the transferring arm, 
 two blades extending from the coupling part and spaced from each other by a predetermined amount, 
 a stepped engaging part having a circular stepped portion extending about a circular region crossing the coupling part and an outer portion of the two blades, the stepped engaging part stepped down from a surface of the coupling part and having a diameter wider than the workpiece, and 
 a spacer part stepped down from the stepped engaging part in a center portion thereof. 
   
   
   
       14 . The transferring device according to  claim 13 , wherein an angle X formed at the center of the diameter of the stepped engaging part between a line extending to a center of the stepped engaging part crossing one of the blades and a line extending to a center of the stepped engaging part crossing the other one of the blades is determined on the basis of a direction of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to a varying rotation speed of the transferring arm. 
   
   
       15 . The transferring device according to  claim 14 , wherein the angle X is calculated as follows:
 calculating a centrifugal force as F (centrifugal) =mdω 2      where “m” refers to the weight of the workpiece  15 , “d” is distance from the rotation center of the transferring device main body  20  to the center of the workpiece  15  (see  FIG. 3 ), and “ω” is an angular velocity (radian/sec) of the transferring device main body,   calculating an angular acceleration α=ω/t,   where “t” refers to acceleration time,   calculating the rotation inertial force according to an angular acceleration as F (rotation) =mdα,   combining the calculated centrifugal force and the rotation inertial force as F=√{square root over (F Q   centrifugal +F Q   rotation )},   and calculating the angle X as   
     
       
         
           
             X 
             = 
             
               
                 
                   cos 
                   
                     - 
                     1 
                   
                 
                  
                 
                   ( 
                   
                     
                       F 
                       centrifugal 
                     
                     F 
                   
                   ) 
                 
               
               . 
             
           
         
       
     
   
   
       16 . A supporting hand usable with a transferring device to transfer a workpiece, comprising:
 a coupling part provided on a first end to couple with a transferring arm of the transfer device;   a couple of blades which extend from the coupling part and are spaced apart from each other; and   a stepped engaging part stepped from the surface of the coupling part and having a predetermined diameter extending across the coupling part and the coupling blades to support the workpiece thereon, the stepped engaging part having a larger diameter than the workpiece.   
   
   
       17 . The supporting hand according to  claim 16 , wherein an angle between the engaging part on the first blade and the engaging part on the second blade is determined on the basis of a direction of a resultant force of a centrifugal force and a rotation inertial force applied to the workpiece according to a varying rotation speed of the transferring arm. 
   
   
       18 . A method of determining an angle between blades of a transfer device supporting hand to transfer a wafer, the method comprising:
 calculating an optimal rotation speed of a transferring device main body; and   calculating an angle between a predetermined part of two blades with respect to a center portion of a wafer holding area of the supporting hand.   
   
   
       19 . The method of according to  claim 18 , wherein the calculating an optimal rotation speed of the transferring device comprises:
 calculating a rotation speed in the speed increasing region where the transferring device main body starts rotating and reaches the optimal speed, the uniform speed region where the transferring device rotates at a uniform speed, and a speed decreasing region where the rotation speed of the transferring device main body becomes 0 from the optimal speed.