Summer 1990

Superior Fine Line Etchants

With the advent of tighter pollution control requirements, manufacturers are looking for improved processes that will not only perform the necessary functions in the manufacturing operation, but will also be easier to waste treat and will require lower capital equipment expenditures to meet pollution requirements.

Among the processes that meet the above requirements is hydrogen peroxide-sulfuric acid based etchants to replace ferric chloride and alkaline etchants used for final etching. Peroxide-sulfuric etchants are relatively new. These etchants offer several advantages in terms of reduced waste treatment, improved atmosphere in the etching room, and considerable savings when recovery of the etched copper is employed.

Michael Carano, Electrochemicals