PWB solutions for High Speed Systems

This paper will describe a method to assist system designers of High Speed Systems in the selection of PWB design/build attributes. The attributes that will be covered are; dielectric material, circuit trace width and thickness, PWB thickness, copper surface roughness, and Plated Through Hole (PTH) stub length. Changes to these attributes are weighed against the cost and the risk of each change to arrive at an optimal system design. Manufacturability limitations that must be considered include board size, drill and plate aspect ratio capabilities, minimum spacing and internal layer registration capabilities. The system requirements may drive design attributes such as low loss dielectrics, subcomposites, microvias, buried vias, and/or back drilling. Such complex board designs will limit the number of capable suppliers that can be quoted so unnecessary complexity needs to be avoided.