Granted Patent
Utility
US 4,967,246 · App. 07/261,708
Structure of insulated gate bipolar transistors
Inventor:
Akio Tanaka
Patented Case
View Patent ↗
Granted: Oct 30, 1990
Filed: Oct 24, 1988
Inventor
Akio Tanaka
Assignee (at issue)
NEC 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.