A mixture of flame-retardant epoxy resin & glass fabric is used to create the FR4 category of printed circuit board materials needed. FR stands for flame retardant & complies with UL94V-0 standards. FR4 is ideal for common applications since it adheres to copper foil well and absorbs little water.
The substance commonly referred to it as FR4 is made of composite materials. Fibreglass that has been interwoven into a thin, fabric sheet forms the material’s base layer. FR4 receives essential structural stability from fibreglass. A flame-resistant epoxy glue is then used to encircle and bind this innermost fibreglass layer. Along with its other physical characteristics, this polymer is what provides the material its stiffness. The epoxy-based FR4 board is favoured by many electronic applications. Electronics engineers should naturally default to using FR4 epoxy substrates due to its strength, dependability, and comparatively inexpensive cost.
FR-4 used in PCBs
For high-quality PCB manufacturing operations, FR4 is the perfect default substrate material because of these characteristics. These characteristics can also serve as the basis for PCBs that are both high-quality and affordable when employed properly. Because of its comparatively inexpensive cost, FR4 material is a highly popular Semiflex PCB basis. On the other hand, high-frequency laminates cost a great deal more. It is a serious negative for PCB manufacturers and designers who are concerned about costs. This is the main criterion that businesses use to decide among FR4 and high-frequency composite materials.
FR4 serves as the main insulating backbone of a PCB. This serves as the foundation upon which the circuit is built by the manufacturer. The FR4 board is prepared and then heated and coated with one or more sheets of copper foil using adhesive. Depending on the board’s design, this copper may wrap one or even both sides and create the circuits inside the finished result.
FR4 sheets can be any thickness, however, they often range between ten to three inches depending on the project’s requirements. The manufacturer or electrical engineer should specify the FR4 thickness when placing an order for a laminate board for a PCB project. Dependent on which is most suitable for the environment, this is evaluated by inch-based units, like a tenth of an inch, thou, or millimetres.