Printed Circuit Board (PCB) Materials
Printed circuit boards (PCBs) are usually a flat laminated composite made from non-conductive substrate materials with layers of copper circuitry buried internally or on the external surfaces. They can be as simple as one or two layers of copper, or in high density applications they can have fifty layers or more. The flat composite surface is ideal for supporting the components that are soldered and attached to the PCB, while the copper conductors connect the components to one another electronically. The six basic components of a standard printed circuit board are: Prepreg Laminate Copper foil Soldermask Nomenclature Final finish Prepreg is a thin glass fabric that is coated with resin and dried, in special machines called prepreg treaters. The glass is the mechanical substrate that holds the resin in place. The resin – usually FR4 epoxy, polyimide, Teflon, and others – starts as a liquid that is coated onto the fabric. As the prepreg moves through the treater, it enters an oven secti