Granted Patent
Utility
US 5,223,452 · App. 07/784,614
Method and apparatus for doping silicon spheres
Inventor:
Vernon E. Knepprath
Patented Case
View Patent ↗
Granted: Jun 29, 1993
Filed: Oct 29, 1991
Inventor
Vernon E. Knepprath
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.