Check Actual Thermal Connections After Rule or Pad Overrides

A polygon connection rule can look correct while an individual pad or via uses a different thermal connection. Local overrides and rule scope can produce exceptions that are hard to see in a crowded board. Review the effective setting and the resulting copper at the specific object.

Altium’s plane rule documentation states that custom thermal relief definitions on pads or vias can override the polygon connection rule. That is a concrete reason to inspect the object when changing a global rule does not produce the expected result.

Identify the intended connection

State whether the feature should connect directly, through a thermal relief, or remain isolated under the applicable design requirement. Consider its electrical role and assembly process. A visually neat spoke pattern is not by itself evidence that the connection is suitable.

Record the pad or via identity, net, copper layer, applicable rule scope, and any object-level override. Check nearby similar features as controls. If one behaves differently, compare its properties before assuming the polygon engine failed.

Inspect the generated copper

Review the actual number and shape of surviving connections after clearances are applied. The requested spoke pattern may be constrained by nearby copper, cutouts, or other objects. A property dialog describes intent; the filled copper shows the realized geometry.

Control exceptions deliberately

1. Find the effective rule and local settings.
2. Remove unintended overrides or document justified ones.
3. Regenerate affected copper.
4. Run relevant design checks.
5. Inspect the final exported copper at the changed features.

Do not fix an unexplained connection by drawing extra copper until the underlying rule behavior is understood. That can produce a result that looks correct temporarily but changes again after a later refill. Prefer a representation whose intent remains clear in the design data.

Evaluate electrical and assembly consequences together when changing the connection style. The appropriate geometry depends on the application and process; this review does not prescribe a universal spoke width or count. Preserve the design requirement and any manufacturing feedback that supported the choice.

A release-ready result has both a traceable configuration and verified copper. Keeping those two forms of evidence makes later changes easier to review, particularly when a library update adds local pad properties that differ from the board’s default rules.