Granted Patent
Utility
US 4,857,435 · App. 07/024,875
Positive photoresist thermally stable compositions and elements having deep UV response with maleimide copolymer
Inventors:
Frederick R. Hopf, Michael J. McFarland, Christopher E. Osuch
Patented Case
View Patent ↗
Granted: Aug 15, 1989
Filed: Mar 17, 1987
Inventors
Frederick R. Hopf
Michael J. McFarland
Christopher E. Osuch
Assignee (at issue)
Hoechst Celanese 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.