Do not subtract registration twiceMask web depends on opening size and pitch. Global mask registration affects pad exposure; it does not independently shrink the web between openings.Do not subtract registration twiceA one-dimensional budget for identical adjacent pad openingsWeb is between openingsNominal webpitch − pad − 2 × expansionRegistration shifts openingsIt changes pad exposure, not thedistance between two openings.Opening-edge growth and global registration are different errors.³Ô¹Ïtv · Engineering explanation · Conceptual, not to scale