Granted Patent
Utility
US 4,943,344 · App. 07/362,099
Etching method
Inventors:
Shinichi Tachi, Kazunori Tsujimoto, Sadayuki Okudaira, Kiichiro Mukai
Patented Case
View Patent ↗
Granted: Jul 24, 1990
Filed: Jun 6, 1989
Inventors
Shinichi Tachi
Kazunori Tsujimoto
Sadayuki Okudaira
Kiichiro Mukai
Assignee (at issue)
HITACHI, LTD.
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.