Patent ID: 6684170
Filing Date: 2004-01-27
Classification: G01R

Abstract:
A method of detecting an integrated circuit in failure among integrated circuits, based on spectrum which is a result of analyzing a frequency of a current running through an integrated circuit when a test signal is applied to said integrated circuit, without preparing data of an integrated circuit in no failure, as a reference, said method comprising the steps of:(a) assuming that all integrated circuits under test define a under-test integrated circuit set, and testing each one of said integrated circuits in said under-test integrated circuit set to judge if any one of said integrated circuits is in failure; (b) modifying said under-test integrated circuit set by removing integrated circuits having been judged to be in failure in said step (a), from said under-test integrated circuit set; (c) measuring spectrum of a current supplied from a power source into each one of said integrated circuits in said under-test integrated circuit set modified in step (b); (d) calculating a mean value and standard deviation of said spectrum for said under-test integrated circuit set modified in step (b); (e) judging whether said standard deviation is equal to or smaller than a predetermined value; (f) modifying said under-test integrated circuit set by removing an integrated circuit having specific spectrum determined based on said mean value, from said under-test integrated circuit set, if said standard deviation is greater than said predetermined value, and repeating said steps (d), (e) and (f); and (g) judging said under-test integrated circuit set modified in said step (b) to be in no failure, if said standard deviation has been judged to be equal to or smaller than said predetermined value in said step (e).