Within the PCB industry, FR-4 materials have long been accepted as “standard” materials. However, their use was not specific to the types of board being designed. For today’s high-speed, high-frequency designs, careful engineering and material selection relative to the resin systems and glass weave styles needed will ensure that a product will work as specified, as designed, and as manufactured. In addition, the finish of the copper used in the signal and power layers also needs to be controlled in order to ensure that loss goals are met.