Three=dimensional impression on record carrier - with metal layer underlying photosensitive layer on substrate

摘要

The surface of the carrier first receives a metal layer of a thickness to suit the desired depth of impression, by vapour deposition or by a wet currentless method (copper on glass). The photo layer is applied to this and exposed through a mask. After dissolving the exposed sections of the photo layer, the accessible sections of the metal alyer are etched away and the remaining sections of the photo layer can be removed. The uniformity and thickness of the photosensitive layer are less important using the above method and also the withdrawal of the press tool from the impression is facilitated.