FR-4 is a common PCB production material, is one of the most widely used PCB substrate, usually used in the manufacture of electronic equipment with a certain mechanical strength and electrical insulation performance requirements of the printed circuit board.
The "FR" in FR-4 stands for "Flame Retardant", while "4" indicates its flame retardant grade, so FR-4 is actually not a material name, but a material grade. So FR-4 is actually not a material name, but a material grade, we can understand that it is a kind of glass fiber reinforced composite material with flame retardant grade 4.
FR-4 is composed of glass fiber cloth and epoxy resin. From the material point of view, the glass fiber cloth gives FR-4 excellent mechanical strength and rigidity, which makes it ideal for manufacturing circuit boards. At the same time, the addition of epoxy resin gives FR-4 good electrical insulation properties, ensuring accurate isolation between circuits; in addition to this, FR-4 also has excellent flame retardant properties, which means that it is not easily combustible, and is able to operate safely and stably at higher temperatures.
