Public evidence metadata ยท SEM-EVIDENCE-0021
This paper converts archived SEM/EDS elemental measurements into estimated physical phase fractions for printed-circuit solder mask. The clean/reference cohort indicates approximately 10-11 vol% total inorganic filler in the modeled mask, with barium sulfate as the principal fitted filler and silica as a smaller but persistent secondary constituent. The paper explains the constrained-regression, stoichiometric, molar-mass, and density basis used to move from ZAF-corrected atomic percentages to mole, weight, and volume fractions. It also separates clean/reference acquisitions from residue-on-mask spectra and states the limits of localized SEM/EDS measurements, the binder surrogate, phase identification, and the small number of independent cases.