Patent ID: 8872532

Claim:
A wafer cassette system for holding a wafer comprising: a base comprising a fiducial, a receiving surface sized to receive said wafer, and a plurality of first alignment elements; a probe card assembly comprising a substrate, a plurality of probes arranged to contact terminals of said wafer, and a plurality of second alignment elements corresponding to said first alignment elements; and wherein said first alignment elements and said second alignment elements comprise complementary shapes capable of interlocking, wherein while interlocked, each pair of one of said first alignment elements interlocked with one of said second alignment elements constrains movement of one of said base or said probe card assembly relative to the other of said base or said probe card assembly in at least a first direction that is substantially parallel to said receiving surface while permitting relative movement of said one of said base or said probe card assembly relative to the other of said base or said probe card assembly in a direction substantially perpendicular to said receiving surface, and wherein while interlocked, each said pair of one of said first alignment elements interlocked with one of said second alignment elements permits movement of said one of said base or said probe card assembly relative to the other of said base or said probe card assembly in a second direction that is substantially perpendicular to said first direction and substantially parallel to said receiving surface.