Abstract: Impurities mixed in the liquid crystal device are detected by a method comprising the steps of applying a DC electric field to a liquid crystal device having a liquid crystal layer between a pair of electrodes, and irradiating the liquid crystal device with light within a specific wavelength, while an AC pulsed electric field is being applied to the liquid A crystal device after the DC electric field is removed to obtain a field response curve corresponding to time-dependent change of light intensity during a cycle of the AC pulsed electric field by time-resolved measurement of light passed through the liquid crystal layer, wherein the impurities are detected on the basis of specific quantitative change in the electric field response curve as a function of elapsed time after the DC electric field is removed.

Abstract: Multiple integrated circuit dice can be simultaneously engaged for probe testing by providing a wedge card having a plurality of needle probes mounted thereon and extending along two orthogonal directions with the probe cards being planarized below a first major surface. Each wedge card can then engage at least two integrated circuits simultaneously. The wedge cards and manipulators can be mounted on a probe card around a central opening for testing integrated circuit die through the opening, alternatively, the probe card and manipulator can be mounted to two movable rods attached to respective pairs of manipulators mounted on a platen around the semiconductor wafer with the rods and manipulators moving the wedge card and manipulator along two axes (X,Y) with the wedge card manipulator moving the wedge card in a third axis (Z).