Patterned articles, such as RFID antenna, are made by subablation, a
process comprising the steps of:
A. providing a substrate having a coating, such as a metal or metal oxide,
and an interface comprising the thin region where the coating and the
substrate are closest to each other;
B. exposing at least one part of the total area of the coating to a flux of
electromagnetic energy, Such as a focused excimer laser beam, sufficient
to disrupt the interface but insufficient to ablate the coating, and
C. removing the parts of the coating in registry with the portion of the
interface area that was disrupted, by means such as ultrasonic agitation.
The process has advantages over photo-resist processes in that there is no
residual chemical resist left on the product and no undercutting of the
pattern or image. It has advantages over laser ablation processes in that
higher throughput is possible at the same energy level and there is no
microscopic debris left on the product surface.