SMD Annular Ring (Pads)

Reports distances less than pp_ar between SMD pads with attribute SMD Pad and solder mask.

Internal ERF Name	<Area>:ar_smd
Measurement Shape Measurement ID	Segment Pad (representing the SMD); Pad (for clearance)
Layers Displayed	Solder mask layer External copper layer
Graphic
Purpose	SMD pads must 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 distances less than pp_ar between SMD pads with attribute SMD Pad and solder mask. Measurements are segments corresponding to the minimal distance between SMD pad and clearance outline.
ERF Parameters	pp_ar
ERF Variables	categorize_negative_ar = 0
Constraint	SMD Pad AR
Limitations	If the clearance is drawn, the clearance entity 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. For actual “negative” annular ring values for gaskets, categorize_negative_ar must be set to 1. Then gaskets are reported in this category.