Patent ID: 8278956

Claim:
A method of maintaining contact between a plurality of microelectronic contactors and terminals of semiconductor devices, the method comprising: coupling a probe card assembly to a prober machine for testing semiconductor devices, the probe card assembly comprising: a plurality of microelectronic contactors for contacting terminals of semiconductor devices to test the semiconductor devices, the plurality of microelectronic contactors being attached to a probe head; a stiffener assembly for providing mechanical support to the microelectronic contactors and for connecting the probe card assembly to the prober machine, the stiffener assembly comprising a first stiffener body with a first central portion and a second stiffener body with a second central portion, the first stiffener body and the second stiffener body being mechanically connected together in only the first central portion and the second central portion; the probe head being attached to the first stiffener body at a plurality of locations outside the first central portion of the first stiffener body; the second stiffener body being attached to the prober machine at a plurality of locations outside the second central portion of the second stiffener body; causing the probe head and the first stiffener body to which the probe head is attached to expand or contract thermally a first percentage substantially in a first plane so that the ones of the probes and the ones of the terminals of the semiconductor devices maintain sufficient alignment to maintain said contact as the semiconductor devices expand or contract thermally; and simultaneously causing the second stiffener body which is attached to the prober machine to expand or contract thermally a second percentage substantially in a second plane substantially parallel to the first plane.