SKEW-DATA ACQUISITION METHOD FOR IC TESTING APPARATUS

摘要

PURPOSE: To acquire skew data at a high speed by a method wherein, regarding ICs to be measured, which can be adjusted within the delay-time width of adjsted skew circuits whose delay time has been adjusted simultaneously, a skew-circuit control value is converged for every IC to be measured and the skew data is stored. ;CONSTITUTION: The delay time of skew circuits 30A in all stations 30 which acquire skew data is made minimum, and it is preserved as a lower-limit value separately from ICs (DUTs) to be measured. Then, the delay time of the circuits 30A in the stations 30 is made maximum. Then, a skew measurement is performed, and the result of a judgment on whether the measurement is proper or not is preserved. Then, whether a skew adjustment can be performed in the variable width of every circuit 30A is judged for every DOT. When any DUT to which the skew adjustment cannot be performed exists, the ICs are deteached and processed in such a way that the skew data is not acquired from now on. Only when the skew adjustment cannot be performed for all the DUTs, data which indicates that they cannot be adjusted with expected accuracy in the delay width of the skew circuits is set.;COPYRIGHT: (C)1995,JPO