Granted Patent
Utility
US 6,518,534 · App. 09/755,379
Welding apparatus for forming chromium oxide passivated film at welded portion
Inventors:
Sowmya Krishnan, Tadahiro Ohmi
Patented Case
View Patent ↗
Granted: Feb 11, 2003
Filed: Jan 5, 2001
Inventors
Sowmya Krishnan
Tadahiro Ohmi
Assignee (at issue)
Ultra Clean Technology Systems and Services 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.