The Evolution of FR-4
FR-4 (or FR4) is a grade designation assigned to glass-reinforced epoxy laminate sheets, tubes, rods and printed circuit boards. It is the primary insulating backbone upon which the vast majority of rigid printed circuit boards are produced. FR-4 is a composite material composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant.
With near zero water absorption, the material is known to retain its high mechanical values and electrical insulating qualities in both dry and humid conditions. Over the past 40-plus years of PCB manufacturing, e-glass supported FR-4 resin laminates have been the materials of choice in the industry. FR-4 resin laminates have superior dimensional stability and give a reasonably acceptable thermal performance. EPCB knows that the competitive prices and performance of FR-4 materials allows designers to get the printed circuit boards they need for nearly any application.