What Is the FR4 Circuit Board?

The FR4 circuit board is the standard name employed in PCB manufacturing. FR is the abbreviation of flame retardant. The value 4 is perceived as the typical rating of the material. The name FR4 is primarily employed in glass epoxy laminated sheets. This is something that appears to be woven and thin cloth sheets.

Basically, the FR4 circuit board is popularly considered to be a composite structure. Its fiberglass composition plays a critical part in providing the FR4 its essential structural stability. The fiberglass layer is based on the inner side, where it is bound and surrounded by epoxy resin that can resist flame. Epoxy resin is essential as it provides FR4 material the suitable rigidity.

Since FR4 works as the backbone of PCB, it is crucial to select the right FR4 material. Some of the available options include:

Standard FR4

FR4 High IRC

FR4 High TG

FR4 no copper

While choosing FR4 circuit board material, there are some aspects that you must keep in mind. One such aspect is the FR4 board thickness measured in inches, thousand, or millimeters.

Usually, the suitable FR4 material must be thin to help develop a PCB board with limited space. The reason to consider thin material is that it can accommodate many fragile components needed to create devices like USB connectors, Bluetooth devices, and other items using PCB boards. Thin FR4 material is yet ideal for creating larger devices where space-saving design is required.

Alternatively, thin FR4 material is best applied in flexible devices. For example, employing a thin FR4 material for medical and automotive PCB boards is appropriate since these boards demand consistent flexing.

Consequently, avoid selecting thin FR4 because it can initiate a higher risk of board fracture or damage.

Furthermore, the thickness of the FR4 material can influence the weight of PCB as well as the compatibility of the components.