Granted Patent
Utility
US 4,888,090 · App. 06/680,120
Etchant for aluminum containing surfaces and method
Inventor:
Nicholas J. Sheetz
Patented Case
View Patent ↗
Granted: Dec 19, 1989
Filed: Dec 10, 1986
Inventor
Nicholas J. Sheetz
Assignee (at issue)
Pennwalt Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.