Improved Overcoat Technique for Thin Heads
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-02
The current method of depositing protective overcoat on thin heads requires many hours of sputter deposition of alumina to a required depth of about 25 micrometers, the substrates are then lapped back to expose the conductive pads. Disclosed herein is a method of depositing a thin overcoat (approximately 8 micrometers) of alumina. Then a selectively etchable pad and its coating of alumina would be chemically removed exposing the gold contact pad. This process eliminates both the need for thick alumina overcoats with their long sputter deposition times and the need for mechanically lapping back to the conductive contact studs.