One and double-sided circuit boards
Single-sided printed circuit boards are used for simple circuits, and in their simplicity are the mother of all printed circuit boards. As the name indicates, the conductor paths are only on one side of the board and the drill holes initially serve to attach the components. These conductor paths are applied by means of photo-technical procedure and the copper is etched away.
Double-sided PCB’s with through-contacts have conducting connections on both sides. The conductor paths have electrolytic contacts by means of drillings, enabling electricity to be directed from paths from one side to the other.