Working with the SMD Entry Design Rule on a PCB in Altium Designer
This document is no longer available beyond version 21.0. Information can now be found here: SMD Entry Rule for version 25
Rule classification: Unary
Summary
This rule specifies the direction(s) a track can enter, or exit, an SMD pad.
Constraints
Default constraints for the SMD Entry rule.
- Any Angle – if enabled, the track can enter/exit the pad at any angle, and at any point along its edge.
- Corner – if enabled, the track can enter/exit through a pad corner.
- Side – if enabled, the track can enter/exit at 90 degrees on either side of the pad. The longer edge of the pad is considered the side, note that the side option is only applied if the
Side length > 2x End length. For example, if the pad is2mm x 1mmthen the side option is ignored (all sides are treated as ends). If the pad is2.1mm x 1mmthen the side option is applied.
How Duplicate Rule Contentions are Resolved
All rules are resolved by the priority setting. The system goes through the rules from highest to lowest priority and picks the first one whose scope expression matches the object(s) being checked.
Rule Application
Online DRC, Batch DRC, and Interactive Routing.
Tips
- The rule applies to surface mount pads only, that is, a pad defined on a single copper layer.
- The end of the pad is determined from the pad dimensions, the ends are the shorter edges.
- Pads can always be entered from either end (the shorter edge)
- The rule is applied on both routing out of the pad (exit) and into the pad (entry).
-
The rule works in harmony with the SMD To Corner design rule, configure both to ensure neat SMD routing.
The SMD Entry rule specifies where the route is allowed to enter/exit the SMD pad, all rule checkboxes are cleared in this example animation. Use the SMD to Corner rule to define the distance to the first corner.