Electronic package substrate with an upper dielectric layer covering high speed signal traces

摘要

An electronic package component includes a flip-chip device mounted to a BGA substrate. The BGA substrate includes conductive traces formed on its upper surface and configured in a coplanar waveguide structure. The package includes a dielectric coating applied over the conductive traces and over the upper surface of the substrate. The coating is formed from a material having a dielectric constant that is equal to or approximately equal to the dielectric constant of the BGA substrate material. The dielectric coating reduces the adverse effects caused by phase velocity dispersion of the signal propagated by the coplanar waveguide.