Granted Patent
Utility
US 4,874,494 · App. 07/157,507
Semiconductor manufacturing apparatus
Inventor:
Tadahiro Ohmi
Patented Case
View Patent ↗
Granted: Oct 17, 1989
Filed: Feb 5, 1988
Inventor
Tadahiro Ohmi
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.