One-sided PCB board: The solder joints are concentrated on a person aspect, and components are usually inserted on the opposite side. Some products continue to have SMD components about the copper-clad facet. Double-sided board: Both sides is usually layout, and both of those may have plug-in components or SMD components. https://toyota-car-turn-signal-do38260.theobloggers.com/37384352/power-goldfinger-module-board-for-server-fundamentals-explained