Abstract: A polymer film is applied onto a surface of a laminated printed circuit board subassembly having vias. Holes are created in the polymer film to access the vias while the polymer film remains covering adjacent areas. The polymer film with holes allows placement of hole-fill paste in the vias while preventing unwanted hole-fill paste placement or migration to adjacent areas. After filling the vias with hole-fill paste, the hole-fill paste is preferably at least partially hardened or cured, and the polymer film is preferably removed, facilitating further assembly of a printed circuit board without unwanted hole-fill paste in other areas which could be difficult to remove, The invention includes improved processes for fabricating printed circuit boards, and is particularly useful for irregular circuit boards and rigid flex circuit boards. The invention also includes covered laminated printed circuit board subassemblies, covered with a removable polymer film.