Portable manipulator for stackable semiconductor test system

Abstract

This invention provides a manipulator for positioning a test head relative to a prober or other reference. The manipulator has a frame; a linkage coupled to the frame and including first and second links having freedom of rotation about respective pivots and a third link coupled to the first and second links such that the third link has translational and rotational degrees of freedom of movement; and an adaptor coupled to the third link and configured to attach to a test head. The invention also provides a method of controlling the manipulator.

1 . An apparatus for positioning a test head relative to a prober, comprising a frame, first and second elongate lead screws, each of the lead screws having an extremity pivotably coupled to the frame, the first lead screw pivotable about a first pivot axis and the second lead screw pivotable about a second pivot axis extending parallel to the first pivot axis, the first and second lead screws rotatable about respective first and second axes of rotation, the first axis of rotation extending perpendicular to the first pivot axis and the second axis of rotation extending perpendicular to the second pivot axis, a link having a first end portion rotatably coupled to the first lead screw and a second end portion rotatably coupled to the second lead screw, at least one actuator coupled to the first and second lead screws for rotating the first lead screw in opposite first and second directions about the first axis of rotation and for rotating the second lead screw in opposite first and second directions about the second axis of rotation and an arm coupled to the link and adapted to carry the test head whereby rotation of the first and second lead screws in the first direction causes the link to translate relative to the first and second lead screws so as to translate the test head relative to the frame and rotation of the first lead screw in the first direction and rotation of the second lead screw in the second direction causes the link to rotate relative to the first and second lead screws so as to pivot the test head relative to the frame.  
   
   
       2 . The apparatus of  claim 1  wherein the at least one actuator includes a first actuator coupled the first lead screw and a second actuator coupled to the second lead screw.  
   
   
       3 . The apparatus of  claim 1  wherein the arm includes a translation mechanism for moving the test head in opposite first and second directions along the arm.  
   
   
       4 . The apparatus of  claim 3  wherein the translation mechanism includes a linear guide rail.  
   
   
       5 . The apparatus of  claim 1  wherein the lead screws are rolling element screws.  
   
   
       6 . A manipulator for positioning a test head relative to a prober, comprising a frame, a linkage coupled to the frame and including first and second links having freedom of rotation about respective pivots and a third link coupled to the first and second links such that the third link has translational and rotational degrees of freedom of movement, and an adaptor coupled to the third link and configured to attach to a test head.  
   
   
       7 . The apparatus of  claim 6  wherein the first and second links are lead screws.  
   
   
       8 . The apparatus of  claim 6  wherein the first and second links are rolling element screws.  
   
   
       9 . The apparatus of  claim 6  wherein the third link is coupled to two independently controllable actuators.  
   
   
       10 . The apparatus of  claim 9 , wherein one actuator is an actuator included in a group of actuators consisting of an electric motor, a hydraulic actuator, and a pneumatic actuator.  
   
   
       11 . The apparatus of  claim 9 , further comprising a control system for synchronous and asynchronous actuation of the linkage.  
   
   
       12 . The apparatus of  claim 11 , wherein the control system includes a computer processor; a position sensor; and an orientation sensor.  
   
   
       13 . The apparatus of  claim 6 , further comprising an arm coupled to the third link for moving the test head relative to the third link.  
   
   
       14 . The apparatus of  claim 13 , wherein the arm includes a linear guide rail.  
   
   
       15 . The apparatus of  claim 6 , wherein the frame includes a plurality of wheels for moving the frame relative to a support surface.  
   
   
       16 . An automatic test system comprising a chassis, a test head mounted on the chassis and configured to couple with test articles, a conveyance for moving test articles towards and away from the test head, and a manipulator including a linkage for translating and rotating the test head to mount and dismount the test head relative to the chassis, the linkage having a movable pivot.  
   
   
       17 . The system of  claim 16 , further including a control system for selectably translating and rotating the test head relative to the chassis.  
   
   
       18 . The system of  claim 16 , wherein the test head and test articles are configured to mechanically couple.  
   
   
       19 . The system of  claim 16 , wherein the manipulator is the apparatus of  claim 1.