what are pcbs made of
Printed Circuit Boards (PCBs) are complex electronic components made from multiple layers of materials, each serving a specific purpose. The foundation of a PCB is typically a substrate made of fiberglass-reinforced epoxy laminate material, commonly known as FR4. This base material provides structural support and electrical insulation. The conductive layers are made of copper foil, which is bonded to the substrate and etched to create the circuit patterns. The copper traces range in thickness from 0.5 to 70 micrometers and serve as pathways for electrical signals. A solder mask, usually green in color, is applied to protect the copper traces and prevent short circuits. The final layer is the silkscreen, typically white, which provides component labels and other identifying information. PCBs can be single-sided, double-sided, or multi-layered, depending on the complexity of the circuit design. Modern PCBs often incorporate advanced materials like polyimide for high-temperature applications, ceramic substrates for better thermal management, and specialized coatings for environmental protection. These boards are essential components in virtually all electronic devices, from simple calculators to complex aerospace systems.