The Hidden Backbone of Modern Electronics

The circuit boards inside your phone are made of FR-4, a material woven from glass fibers. It is uniquely engineered to stop fires from spreading by self-extinguishing if it overheats.

This material is a composite of thin glass cloth bonded with an epoxy resin. Because it is incredibly sturdy and heat resistant, it provides the structural foundation for almost every electronic device you own. The letters FR actually stand for flame retardant, a vital safety feature for high-voltage gadgets. Without this specialized fabric, our modern pocket technology would be much more flammable and fragile.