Simplified model for on-chip interconnects in electromagnetic modelling of System-in-Package

We present effective medium approximation (EMA) that provides an homogeneous equivalent for the top layer of on-chip interconnects in an integrated circuit. An empirical mixing model for straightforward and fast extraction of the effective dielectric constant of a slab of integrated circuit wiring and its analytical formulation based on Maxwell-Garnett rule is presented for a range of aspect ratios, dielectric materials, metal fills, and frequencies. We expect this approach to find use in the electromagnetic modeling of System-in-Package. Experimental validation of proposed approach is demonstrated by free space measurement of a grating structure illuminated by a pair of lens horn antennas.