Parts having complexly curved, frequency selective surfaces can be manufactured with a high degree of precision using a three-dimensional conformal mask. The mask has a transparent substrate and a patterned opaque layer on the substrate. The layer may be patterned by laser ablation. Alternatively, the...http://www.google.es/patents/US5552249?utm_source=gb-gplus-sharePatente US5552249 - Method for making a mask useful in the conformal photolithographic manufacture of patterned curved surfaces
Method for making a mask useful in the conformal photolithographic ...
