They are glass-reinforced hydrocarbon/ceramic thermoset laminates that reportedly provide superior high-frequency performance and can be economically used in standard epoxy/glass (FR4) processes. RO4350 can be used in lead-free processing and complies with the RoHS Directive. Another high-frequency circuit material, RO4450B, is a glassreinforced hydrocarbon/ceramic thermoset bondply designed for multilayer printed-circuit boards. It can also be fabricated using standard epoxy/glass (FR4) processes.