Patent ID: 6043667
Filing Date: 2000-03-28
Classification: G01R

Abstract:
A substrate tester for testing a substrate according to a particular testing operation, said tester comprising:a substrate carrier for receiving the substrate to be tested therein, the substrate carrier having a rough locator for roughly locating the substrate therein with respect to said substrate carrier;a lift plate having a first test head assembly and a substrate locator mechanism thereon, said lift plate being disposed for travel in a z-axis direction between a home position, an intermediate position, and a probing position, said lift plate further having mechanical stop pins thereon;a carrier plate having slots therein for horizontally receiving the substrate carrier, said carrier plate being disposed for travel in the z-axis direction between the intermediate position and the probing position;a bridge plate disposed above said lift plate, and said carrier plate, said bridge plate having a second test head assembly mounted on an underside thereof, the second test head assembly having a electrical contact disposed at the z-axis probing position; andmeans for controlling a travel of said lift plate from the home position to the probing position, wherein the mechanical stop pins of said lift plate pick up said carrier plate at the intermediate position, and further at the intermediate position, a top surface of the first test head assembly engages the substrate carrier from below and the substrate locator mechanism accurately positions, locates, and clamps the substrate with respect to an exact center of the substrate in a precise X-Y location.