Tests Performed in Solder Mask Checks

Several solder mask checks analysis tests can be run. For each test performed, results might be reported to the result categories available for that test. In the result category descriptions in this document, the test name is indicated in parentheses after the category name.

Drill — Reports close distances to solder mask openings of PTH or NPTH annular rings, and where NPTH touches mask.
Pads — Reports close distances to solder mask openings of all pads, including undrilled pads. It also reports on gaskets.
- Pad Annular Ring Categories — These categories report pad annular ring results. Some can be used to classify the Pad Annular Ring measurement according to the pad type: PTH Pads, NPTH Pads, Via Pads and Non-Drilled Pads. This option is activated by setting ERF variable classify_pad_ar = 1.
  
  Annular ring categories do not report a pad (or drill) completely covered by solder mask. Zero annular ring might be reported if a solder mask clearance and a pad drill overlap, but neither includes the other.
- Gasket Categories — These categories reports on measurements of gasket annular rings. Gaskets are overlapping sections of solder mask onto board features, such as pads. This makes the solder mask opening smaller than the pad.
  
  The system measures this by assuming a negative annular ring, that is an annular ring that dips into the pad rather than extends beyond it. To indicate to the system that you want to activate the ‘gasket’ categories (that is, consider negative annular rings), set the ERF variable categorize_negative_ar to 1 (active). When categorize_negative_ar is set to 0 (inactive), the system globally assigns a zero value to all negative annular rings and they are reported to “Pad Annular Ring (Pads)”.
This example illustrates a gasket:
Coverage — reports lines too close to clearances (that is, not adequately covered).
Sliver — Reports slivers between solder mask clearances. See “Sliver and Short Sliver Categories (SM)”
Missing — reports missing clearances.
Spacing — reports close spaces between clearances (wider than sliver).
Extra — reports solder mask features that do not intersect with copper.