Test structure designed for vias in multi-layer package substrate

A symmetrical test structure for the measurement of vias in multi-layer package substrate was put forward in this paper. Based on the known S-parameters of this designed symmetrical structure and the deduced expressions, an indirect method to get the actual S-parameters of a single via was presented. In order to verify the validity of the proposed method, the simulation models were built in Power SI environment from SIGRITY. After a comparison between the simulated and calculated results, the correctness of the proposed method was proved.