Texas Instruments Incorporated
MULTI-SITE CONCURRENT WAFER PROBE MAGNETIC CIRCUIT TESTING

Abstract:

A wafer probe test system having a probe card with a probe head, a rotary magnet, a magnetic sensor positioned to sense the magnetic field of the rotary magnet and a controller coupled to the probe card, where the probe head has probe needles to engage features of test sites of a wafer in a wafer plane of orthogonal first and second directions, and the rotary magnet is rotatable around an axis of a third direction to provide a magnetic field to the wafer, in which the controller includes a model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of a rotational angle of the rotary magnet, a probe needle height along the third direction and a measured magnetic flux density of the magnetic sensor.