Suppressor for Cu Circuit Etching
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2005-Feb-16
A pattern is written on a Cu layer, disposed on a dielectric, with black wax dissolved in trichlorethylene or with ink in a No. 3000 Sharpie felt tip pen manufactured by Sanford, Inc. The black wax and ink act to suppress Cu etching in an ammonium persulfate plating bath. The felt tip pen has the advantage of easy use to write a pattern such as with an X-Y recorder or other mechanically driven device. The ink also does not crack when the copper layer is flexed.