Most electrical engineers and individuals involved with printed circuit boards are familiar with the material FR4. FR4 is the backbone material upon which most rigid circuit boards are built. However, many are unaware of what FR4 is, let alone why it is the most popular PCB base.To get more news about fr4 board, you can visit pcbmake official website.
Read on to learn more about FR4 printed circuit boards, such as what they are, why they are so popular and how FR4 PCB specifications compare to other options within the industry.

FR4, also written as FR-4, is both a name and a rating. The name is applied to the fiberglass-reinforced epoxy-laminated sheets used in printed circuit board manufacturing. However, the name also functions as a grade used to rate epoxy laminate sheets. The designation essentially indicates the base quality of a laminate sheet, meaning a variety of sheet materials and designs fall under the FR4 rating. The “FR” in the name stands for flame retardant, while the 4 differentiates the material from others of the same class.
The material widely referred to as FR4 is a composite structure. The most basic layer of the material is fiberglass woven into a thin, cloth-like sheet. The fiberglass gives FR4 its necessary structural stability. This innermost fiberglass layer is then surrounded and bound by a flame-resistant epoxy resin. This resin is what gives the material rigidity, among its other physical properties.FR4 sheets are widely popular among electrical engineers and designers as a PCB base material
FR4 sheets are widely popular among electrical engineers and designers as a PCB base material. The low cost and versatility of the material, as well as its wealth of beneficial physical properties, accounts for that popularity. FR4 sheets are electrical insulators with high dielectric strength. They also feature a high strength-to-weight ratio and are lightweight and resistant to moisture. Add this to their relative temperature resistance, and FR4 can perform well in most environmental conditions.
These qualities make FR4 an ideal default substrate for quality PCB manufacturing processes. When used appropriately, these properties can also form the foundations of high-quality and low-cost PCBs.
Within a PCB, FR4 forms the primary insulating backbone. This is the base upon which the manufacturing company builds the circuit. Once prepared, the FR4 board is laminated with one or more layers of copper foil using heat and adhesive. This copper forms the circuits in the finished product and may cover one or both sides, depending on the design of the board.
Complex PCBs may use more than one side or even layer the circuit board to produce more sophisticated circuits. From here, the circuits are drawn and etched out before being covered with a solder mask layer, preparing the board for the final silkscreen layer and the subsequent soldering process.