Electrical characterization of printed circuit board interconnects: Measurements and analysis

The characteristic impedance of the traces of a 10 layer printed circuit test board was calculated using three different field solvers. The traces consisted of microstrips and different types of striplines. The characteristic impedance and the time-of-flight were also measured using a Tektronix TDR and a HP network analyzer. The values obtained from the field solvers were compared with the measured values. The suitability of the solvers to model interconnects (traces) was analyzed. The results obtained from the three field solvers compared well with the measured data for trace separations above three mils. The measured and the calculated results differed by more than 10 percent in some cases where the trace separations were less than three mils. This study provides a framework for evaluating the applicability of a field solver for modeling multilayer printed circuit board traces.