PCB design glossary
Design Rules
The set of physical constraints a PCB layout must respect — trace width, clearance, via size, drill diameter, courtyard.
Design rules encode what your fabricator can build. Minimum trace width and clearance are the most-cited; drill sizes, annular ring, and copper-to-edge clearance also matter.
Picking the right rules up front saves rework. PCBEditor ships with profiles for JLCPCB, PCBWay, OSHPark, and custom rules — DRC will enforce them as you route.
The rules that matter most
Low-cost fabs commonly build around 0.127 mm (5 mil) trace and space and 0.3 mm drills on standard boards. Designing slightly above your fab's minimums costs nothing and improves yield.
- Minimum trace width and minimum clearance between copper.
- Minimum drill size, via pad size and annular ring.
- Copper-to-board-edge clearance.
- Hole-to-hole spacing.
- Soldermask dam and silkscreen minimums.
Net classes: different rules for different nets
Not every net needs the same rules. Power nets get wider traces, high-voltage nets get wider clearance, and differential pairs get fixed width and spacing to hit an impedance. Net classes apply those rules to groups of nets, so the router and DRC treat each one correctly.
Setting rules before routing
Enter the fab's rules before placing a single trace. Routing first and tightening rules later means rework; routing to rules looser than the fab's means a board that cannot be made. PCBEditor ships profiles for JLCPCB, PCBWay and OSH Park so the rules match a real fab from the start.
Work it out with a free tool
Set the rules before the first trace
In PCBEditor you choose a fab's rule preset (trace width, clearance, via size) before routing, so the router and the design-rule check work to the same limits.
Design to a fab preset