ABSTRACT
In the past few years increasing clock speeds and the use of higher frequencies in commercial electronics have resulted in a convergence of requirements between what have traditionally been considered “conventional” PWBs and those that were considered as “microwave and RF.” As a result, there has been a broad-based effort to optimize the performance and reduce the cost of PTFE-based microwave laminates, concurrent with an effort to develop non-PTFE, cost-effective alternative materials for applications where the full package of properties associated with PTFE can be “designed around.” It has become increasingly difficult for lossy (0.025 to 0.03) FR-4 and its derivatives to meet the needs of packaging at frequencies above 1 to 2 GHz where signal-to-noise ratio is critical. In this chapter we will look at PTFE laminates as well as some of the alternatives that have been developed.
