- Silkscreen/Legend colors
- white, yellow, black, pink, red
- Maximum hole aspect ratio
- Blind/buried vias
On a single-sided board,most basic PCB, the parts are concentrated on one side and the wires are concentrated on the other side. Because the wire only appears on one side, we call this built-in PCB a single-sided board. Because single-sided boards have many strict restrictions on the design line (because there is only one side, the wiring can not be crossed and must be around a separate path), so only the early circuit, the use of such boards.