Alkali metal halide phosphor layer prodn. - by inclined vapour deposition to obtain layer island regions

摘要

In prodn. of an alkali metal halide layer on a substrate (AS) which is sepd. into different layer regions (IN) by a pattern of pits (Gr), halide is vapour deposted at an acute deposition angle onto a substrate (AS) contg. a pattern of recesses corresp. to the desired pits (Gr). Phosphor layer, with high position resolution for incident radiation, has layer regions (islands) of 50-500 microns max. dia. completely sepd. from one another by a pit pattern and is applied on a substrate with recesses of 5-50 microns width corresp. to the pit pattern. Phosphor layer is pref. a 400-500 microns thick doped CsI layer arranged above a photovoltaically active semiconductor body a CCD camera, or a light guiding fibre plate. Substrate recesses have sloping flanks with an inclination angle greater than the deposition angle so that shadow regions are created. Recesses have an inclination angle of at least 45 deg. and a width of 5-50 (pref. 20-30) microns. During deposition, the substrate (AS) is rotated and held at 50-250 deg. C.. USE/ADVANTAGE - Phosphor layer is used in a phosphor screen for digital radiography. High position resolution layer is obtd. simply and reproducibly.