Patent ID: 8625300

Claim:
A computer program product comprising a computer-readable device storing program instructions, wherein the program instructions are program instructions for designing layers of a substrate for mounting and interconnecting a semiconductor die, and wherein the program instructions comprise: program instructions for first identifying locations of signal-bearing vias from among a pattern of large-diameter conductive vias extending from a top side to a bottom side of a core comprising a dielectric layer; program instructions for second identifying signal-bearing conductive path profiles for critical signals routed above or below ends of the signal-bearing vias; and program instructions for generating a first mask design for a transmission line reference plane metal layer including voids around the profile of the signal-bearing vias so that capacitive coupling between the ends of the signal-bearing vias and the transmission line reference plane metal layer is substantially reduced, and wherein for the signal-bearing conductive path profiles identified by the second identifying, the program instructions for generating include a conductive stripe extending through the corresponding void.