Granted Patent
Utility
US 4,493,418 · App. 06/523,851
Wafer processing cassette
Inventor:
Douglas M. Johnson
Patented Case
View Patent ↗
Granted: Jan 15, 1985
Filed: Aug 17, 1983
Inventor
Douglas M. Johnson
Assignee (at issue)
Empak, Inc.
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.