When designing a Printed Circuit Board (PCB), it is very tempting to squeeze all the components tightly together to make the final product as small as possible. However, components need "breathing room."

If you place parts too close together, the factory cannot build your board reliably. The minimum distance between parts—often called "clearance"—is critical. Without enough space, molten solder can connect two separate parts, creating a "bridge" or short circuit that ruins the board.

How much space is enough? It depends mainly on two factors: Board Density and the Soldering Method.

Board Density (How crowded is the neighborhood?)

The IPC-7351 standard defines three distinct levels of density. These levels determine how much "excess" space (or courtyard) you must leave around each component.

Think of it like housing:

• Level A: A country estate with a big yard.
• Level B: A …

— Article from E-Cad Bridge —