A printed circuit board ( PCB ), also called printed wiring board
( PWB ), is a medium used to connect or "wire" components to one another
in a circuit. It takes the form of a laminated sandwich structure of
conductive and insulating layers: each of the conductive layers is designed
with an artwork pattern of traces, planes and other features (similar to wires
on a flat surface) etched from one or more sheet layers of copper laminated
onto and/or between sheet layers of a non-conductive substrate.