Probe card changer system and method

A prober-to-test head interface system, comprising;

• a carriage having a plurality of cam followers on the perimeter of said carriage;
• a cam ring having a plurality of cam grooves on the interior of said cam ring;
• positioning means detachably coupled to said carriage for positioning said cam followers in said cam grooves, said positioning means comprising:
• an arm detachably coupled at one end to said carriage;
• a first air cylinder coupled to another end of said arm for moving said carriage in a direction substantially parallel to the plane of said cam ring;
• and
• a second air cylinder coupled to said another end of said arm and said first cylinder for moving said carriage in a direction substantially perpendicular to the plane of said cam ring;
• rotating means coupled to said cam ring for rotating said cam ring, thereby causing said cam followers to track in said cam grooves and move said carriage in a direction perpendicular to the plane of said cam ring, said rotating means comprising:
• a cam-locking cylinder coupled to said cam ring for rotating said cam ring when said cam-locking cylinder is actuated, and
• a theta ring concentric with and adjacent said cam ring for finely adjusting the angular positioning of said carriage with respect to the orientation of a device under test.

A method of testing a semiconductor wafer in a prober tester comprising the steps of:

• positioning a carriage having a probe card disposed therein and a plurality of cam followers on the perimeter of said carriage in a cam ring having a plurality of cam grooves located on the interior of said cam ring to engage said cam followers in said cam grooves, the probe card having a plurality of test pins;
• rotating said cam ring, thereby causing said cam followers to track in said cam grooves and move said carriage in a direction perpendicular to the plane of said cam ring, thereby coupling said probe card to a test head;
• rotating a theta ring coupled to said cam ring, thereby finely adjusting the angular position of said carriage with respect to the orientation of a device under test;
• positioning the semiconductor wafer such that said test pins make contact with the semiconductor wafer;
• and
• probing the semiconductor wafer.