Formation of punch inspection masks and other devices using a laser

Exposure masks and inspection masks for use in the electronics field may be made using laser beams wherein the mask comprises a substrate which is substantially unaffected by exposure to the laser beam and an opaque pattern forming layer on the substrate, which pattern forming layer absorbs the laser beam and is selectively etched when exposed to the laser beam. A preferred mask has an overcoat transparent layer. A cavity inspection mask is provided having a series of openings in the form of lines formed in the opaque pattern forming layer, the lines bounding the cavity walls, is the mask being used for determining if the cavity is centrally positioned on the substrate and/or that the cavity is of the desired size. Substrates containing identifying masks thereon which cannot be seen by the unaided eye for theft deterrence are also provided.