VERFAHREN ZUR HERSTELLUNG EINER NACHBILDUNGSMATRIZE

摘要

A stamping die with a three-dimensional pattern is made by by using a substrate coated with a thin metal film and then a layer (I) of volatile data storage material contg. a stored two-dimensional pattern of holes obtd. by local evapn. of layer. Layer (I) has a thickness matching the desired stamping depth. and is coated with an electrically conducting film (II) followed by an electrodeposited layer. Substrate is then removed and layers (I) and (II) are removed by chemical etching. Substrate is pref. transparent plastic. The metal film is 25 angstroms of Cr and layer (I) is pref. a mixt. of Bi and Se, which is covered by another film of Cr 100 angstroms thick. Layer (II) being applied on top of layer and esp. consisting of Cu 2000-3000 angstroms thick. The electrodeposited layer is pref. obtd. from a nickel sulphamate bath. The die obtd. is used to press a phase contrast pattern into a transparent plastic disc similar to a gramophone record, which can be read out via a laser beam.