Optical testing device

Abstract

A chuck adapted to test electrical and/or optical components on a device-under-test (DUT).

1 . A test assembly comprising: 
 (a) a chuck for supporting a device under test;    (b) said chuck defining an optical path that is transmissive to an optical signal; and    (c) a conductive member at least partially laterally spaced apart from said chuck connected to a guard potential.    
   
   
       2 . The assembly of  claim 1  wherein said chuck has a conductive surface in face-to-face abutment with said device under test when said device-under-test is supported thereon.  
   
   
       3 . The assembly of  claim 1  wherein said chuck has a planar upper surface for supporting said device-under-test.  
   
   
       4 . The assembly of  claim 1  wherein said chuck defines a substantially circular optical path there through.  
   
   
       5 . The assembly of  claim 1  wherein said optical signal originates from said device-under-test.  
   
   
       6 . The assembly of  claim 1  wherein said optical signal originates at a location spaced apart from said device-under-test.  
   
   
       7 . The assembly of  claim 1  wherein said conductive member is at least partially laterally surrounding said chuck.  
   
   
       8 . The assembly of  claim 1  wherein said chuck and said conductive member are spaced apart from each other.  
   
   
       9 . The assembly of  claim 8  further comprising an insulating member located between said chuck and said conductive member.  
   
   
       10 . The assembly of  claim 1  wherein said optical path includes an optically transmissive material through which said optical signal passes.  
   
   
       11 . The assembly of  claim 10  wherein said optically transmissive material includes a conductive coating electrically connected to said guard potential.  
   
   
       12 . The assembly of  claim 11  wherein said conductive coating is located below said device-under-test.  
   
   
       13 . The assembly of  claim 1  wherein said conductive coating is located above said device-under-test.  
   
   
       14 . The assembly of  claim 1  wherein said conductive member laterally surrounds a majority of said chuck.  
   
   
       15 . The assembly of  claim 1  wherein a shield potentially is laterally spaced apart from said chuck.  
   
   
       16 . The assembly of  claim 15  wherein said shield potential is provided at a location laterally spaced apart from said chuck.  
   
   
       17 . The assembly of  claim 1  wherein said device-under-test is maintained on said chuck by a vacuum.  
   
   
       18 . The assembly of  claim 10  wherein said optically transmissive material is substantially co-planar with an upper surface of said chuck.  
   
   
       19 . The assembly of  claim 10  wherein the combination of said optically transmissive material and said chuck support said device-under-test over a majority of the surface area of said device-under-test when said device-under-test is supported thereon.  
   
   
       20 . A test assembly comprising: 
 (a) a chuck for supporting a device under test;    (b) said chuck defining an optical path that is transmissive to an optical signal; and    (c) a conductive member positioned at least partially within said optical path wherein said optical signal passes through at least a portion of said conductive member, wherein said conductive member is connected to a guard potential.    
   
   
       21 . The assembly of  claim 20  wherein said conductive member is located above said device-under-test.  
   
   
       22 . The assembly of  claim 20  wherein said conductive member is located below the device-under-test.  
   
   
       23 . The assembly of  claim 22  further comprising another conductive member positioned at least partially within said optical path located above said device-under-test wherein said optical signal passes through at least a portion of said another conductive member, wherein said another conductive member is connected to said guard potential.  
   
   
       24 . The assembly of  claim 20  wherein said chuck has a conductive surface in face-to-face abutment with said device under test when said device-under-test is supported thereon.  
   
   
       25 . The assembly of  claim 20  wherein said chuck has a planar upper surface for supporting said device-under-test.  
   
   
       26 . The assembly of  claim 20  wherein said chuck defines a substantially circular optical path there through.  
   
   
       27 . The assembly of  claim 20  wherein said optical signal originates from said device-under-test.  
   
   
       28 . The assembly of  claim 20  wherein said optical signal originates at a location spaced apart from said device-under-test.  
   
   
       29 . The assembly of  claim 20  wherein said chuck and said conductive member are spaced apart from each other.  
   
   
       30 . The assembly of  claim 20  wherein a shield potentially is laterally spaced apart from said chuck.  
   
   
       31 . The assembly of  claim 20  wherein said device-under-test is maintained on said chuck by a vacuum.