FR-4 : This is the most commonly used material in printed circuit boards. It is a glass reinforced epoxy laminate sheet. The epoxy used is flame retardant and water resistant. It provides good strength to weight ratios. The tensile strength offered by this material is very high.
PTFE (Teflon): PTFE is a kind of plastic material that does not provide any resistance, thus is used for high speed, high frequency applications. PTFE is extremely flexible, making it invaluable in applications with tight tolerances. It is also extremely lightweight, allowing it to be used across various industries. It is also flame resistant, exhibits high physical strength, provides temperature stability, and is versatile in application.
Metal :The traditional materials of copper, aluminum, iron, etc. are still used in printed circuit boards. These materials allow the use of Surface Mount Technology (SMT) for the integration of components. They also provide mechanical durability. Thus, the product life of metal base PCBs is much longer.