How are printed circuit boards manufactured?

Printed circuit board are electronic circuits created by mounting electronic components on anonconductive board, and creating conductive connections between them. The creation ofcircuit patterns is accomplished using both additive and subtractive methods. The conductivecircuit is generally copper, although aluminum, nickel, chrome, and other metals are sometimesused. There are three basic varieties of printed circuit boards: single-sided, double-sided, andmulti-layered. The spatial and density requirement, and the circuitry complexity determine thetype of board produced. Printed circuit boards are employed in the manufacturing of businessmachines and computers, as well as communication, control, and home entertainment equip-ment.