Integrated circuit interconnections testing

Claim 1

A test system for testing interconnections extending at least in part along a surface of a structure to one or more integrated circuits mounted on that structure, said test system comprising: a first integrated circuit mounted on said structure with a first said interconnection extending to a first input signal region therein, said first integrated circuit having both operating circuits and test circuits contained therein electrically connected to said first input signal region with at least a first portion of said test circuits being capable of being selected by control signals provided at a control signal region in said first integrated circuit to retain therein at least temporarily one or more portions of input signals provided at said first input signal region, said test circuits further being capable of providing response signals at least at one output signal region of said first integrated circuit in response to input signals retained in said test circuits first portion from said first input signal region, said test circuits first portion having therein a switchable resistance means electrically connected between said first input signal region and a first selected source of voltage and being additionally capable, if selected, of switching said switchable resistance means from being substantially an open circuit between said first input signal region and said first selected source of voltage to providing a selected resistance value therebetween in response to said control signals; a test control signal source means electrically connected to said first integrated circuit control signal region and capable of providing selected control signals thereto to cause said test circuits first portion resistance means to switch between providing a substantially open circuit and providing a selected resistance value between said first input signal region and said first selected source of voltage; a test signal source means electrically connected to said first interconnection at a location differing from that at which said first interconnection is connected to said first integrated circuit first input signal region, said test signal source means being capable of providing selected test signals on said first interconnection; and a test response receipt means electrically connected to said first integrated circuit output signal region to receive said response signals.