Electrical performance of interconnects in polyimide-copper thin-film multilayers on ceramic substrate

Thin-film multilayer substrate technology with dielectric layers made of polyimide resin requires openings on the ground plane for the outgassing of the resin. This paper describes a full electrical characterization of transmission lines in a multichip module based on thin-film multilayer on ceramic. Both time and frequency domain methods were used for the experimental characterization. Measured and modeled performances are compared for three kinds of ground opening geometries.