Printed Circuit Board

A printed circuit board, or PCB, is a laminated sandwich of conductive and insulating layers that carries copper traces functioning like wires, letting electronic components be connected and powered without the point-to-point wiring earlier electronics relied on. Components are attached to the board's conductive pads by soldering, which fixes them in place mechanically and makes the electrical connection at the same time, an approach that made mass production of complex circuits far cheaper and more reliable than hand wiring. The Austrian engineer Paul Eisler is credited with inventing the printed circuit around 1936 while working in Britain, and the technology was adopted by the American military during the Second World War for proximity fuzes; by the mid-1950s printed circuits were standard in consumer electronics such as radios and televisions.