printed circuit, electric circuit in which the conducting paths connecting circuit components are affixed to a flat, insulating base board. The base is typically of plastic, glass, ceramic, or some other dielectric, and the conducting paths may be placed on it by a variety of methods. An etched circuit is a subtractive method in which a metallic foil is bonded to the base, the circuit pattern drawn on the foil with an acid-resistant wax, and the remainder of the foil then etched away with acid, leaving the desired conducting pattern. For a multilayered circuit electroplating was frequently used in the past, but today silk screen printing with conducting polymer inks is commonly used. The circuit components themselves—resistors, capacitors, and other devices—are mounted on the finished base afterward, either with their leads being inserted through holes drilled through both the conducting pattern and the base and soldered to the conducting strips or, increasingly, by directly soldering leadless components to the circuit.
See C. F. Coombs, Jr., Printed Circuits Workbook Series (1990).