Granted Patent
Utility
US 5,324,804 · App. 08/051,720
Photoresist material based on polystyrenes
Inventor:
Alfred Steinmann
Patented Case
View Patent ↗
Granted: Jun 28, 1994
Filed: Apr 22, 1993
Inventor
Alfred Steinmann
Assignee (at issue)
Ciba-Geigy
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.