Test circuit for CMOS lead open detection by supply current testing under AC electric field application

A test circuit is proposed for detecting lead opens of CMOS ICs by measuring the supply current of a CMOS circuit made of the ICs which flows when AC electric field is applied from the outside. A signal of a sine waveform is provided to the test circuit. In the test circuit, the amplitude of the signal increases in proportion to time during a prespecified time. The amplified signal is provided to electrodes for AC electric field to be supplied to a circuit under test. When supply current change which is larger than a threshold value appears, it stops increasing the amplitude and the test circuit concludes that a lead open occurs in the circuit. If the elevated supply current change does not appear within the specified time, the test circuit concludes that the circuit is fault-free. It is shown by our experiments that lead opens in a CMOS IC is detected with the test circuit.