Deposition mask and methods of making same

Abstract

The invention provides a reinforced mask which enables closely spaced strips or other narrowly separated parts of a deposited pattern to be formed upon a substrate by a non-line-of-sight deposition process (such as ion plating or sputter deposition) without causing unwanted voids or discontinuities to appear in the deposited pattern at points that underlie the reinforcing ribs on the mask. The mask is formed by a selective material removing process that produces a thin web adjoining one or more relatively thick ribs that provide rigidity to the web. In those parts of the mask where the reinforcing ribs extend across slots or other openings in the web, the masking material is removed to a depth which exceeds the web thickness, thus raising the undersides of the ribs above the web surface to provide clearance for the vaporized material which is being deposited upon the substrate through the mask openings so that this material has ready access to points located directly beneath the ribs as well as points that are between the ribs. The ribs therefore can serve their reinforcing function without producing unwanted voids or thin spots in the deposited pattern.