Purpose

SMD pads are required to be free of mask but typically with a smaller annular ring than plated through hole pads.

This is why they have their own category.

Function

Reports SMD pad to solder mask distances that are less than the pp_ar action parameter.

Measurements are distance segments corresponding to the minimal distance between the SMD pad and the clearance outline.

Activation

When .smd attributes are set for the external layer pads.

Known Limitations

If the clearance is drawn, the clearance ID will be r0 because no single feature corresponds to the clearance.

Solder mask gaskets (clearance smaller than the pad) are reported as zero annular ring). If the user wants the actual negative annular ring values for such gaskets, the ERF variable categorize_negative_ar must be set to 1. Then gaskets will be reported under the SMD Pad Gasket category.