Diagnostics of the ICs solder joints by measuring voltage of the constant component of signal-response that appears at the influence of the periodic sequence of the electric current square pulses

Below are the results of the measurements of U_CN voltage of the constant component of signal- response of the test samples of solder joints of chip imitator of integral circuit (IC) and substrate made of polyimide film while applying periodic sequence of square pulse of electric current. The samples with high and abnormally high U_CN voltage level were detected with their resistance still within the range of values for the rest of the samples. The test sample with abnormally high U_CN voltage level showed noninertial properties and was the carrier of hidden defects in the area of solder joint (inhomogeneities, pores, thin dielectric layers, metal film corrosion). Qualitative samples showed inertial properties and had low U_CN voltage levels, proportional to the durability of pulses of electric current. The results of the measurements prove high informativity of the diagnostic method by U_CN level while applying pulses of electric current, and the sensitivity to the hidden defects in the area of solder joints ICs. The results of the work can be used while working out automatized means of operational integral electrophysic diagnostics of conducting test IC structures with high requirements to their maintenance reliability.