Eight key HDI design principles

High‐density interconnect (HDI) continues to be the fastest growing segment of the printed circuit board (PCB) market. The purpose of this paper is to discuss the differences in designing HDI compared to conventional PCB multilayers. This is important for the challenging aspects of very high‐speed electronics that require care to control signal integrity and power integrity.

Eight new design principles were studied and illustrated with emphasis on how these differ from conventional PCB design.

HDI implementation can be improved 2X to 4X by employing these new design principles. Densities from 6‐12 in. per sq. inch to 18‐48 in. per sq. inch have been reported. Design time reductions of 50 percent and cost reductions of 30 percent were also seen.

This work was focused on the basic design principles and does not address electronics design automation tools or specific design steps. PCB design is a complex activity and readers are encouraged to obtain and use the references cited.

The paper describes various design and layout procedures that the authors have learned over the last 29 years involved in printed circuit design and fabrication. These principles can be combined with other innovations to enable a much more beneficial use of HDI technologies.