Granted Patent
Utility
US 4,931,381 · App. 07/268,640
Image reversal negative working O-quinone diazide and cross-linking compound containing photoresist process with thermal curing treatment
Inventors:
Mark A. Spak, Donald Mammato, Dana L. Durham, Sangya Jain
Patented Case
View Patent ↗
Granted: Jun 5, 1990
Filed: Nov 8, 1988
Inventors
Mark A. Spak
Donald Mammato
Dana L. Durham
Sangya Jain
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.