What are the Common Material of Circuit Board ?
The printed circuits are made of copper, which is either plated or etched away on the surface of the substrate to leave the pattern desired. The copper circuits are coated with a layer of tin-lead to prevent oxidation. Contact fingers are plated with tin-lead, then nickel, and finally gold for excellent conductivity. Purchased components include resistors, capacitors, transistors, diodes, integrated circuit chips, and others.
FR stands for Fire Retardant. FR4 is a glass fiber epoxy laminate. It is the most commonly used PCB material. A 1.60mm FR4 uses 8 layers of (7628) glass fiber material. The red UL/manufacturers logo is in the middle (layer 4). There are two types of logos: red and blue logos. Red is UL94-V0, blue is UL94-HB. If you have a blue logo material, it is either XPC (phenolic) or G10 (glass epoxy); these are older materials.