Granted Patent
Utility
US 4,929,432 · App. 07/259,892
Process for producing crystalline silicon nitride powder
Inventor:
Wei Shen
Patented Case
View Patent ↗
Granted: May 29, 1990
Filed: Oct 19, 1988
Inventor
Wei Shen
Assignee (at issue)
Union Carbide 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.