Granted Patent
Utility
US 4,880,495 · App. 07/037,477
Regeneration of copper etch bath
Inventors:
Kestutis F. Petraitis, Walter Baldauf
Patented Case
View Patent ↗
Granted: Nov 14, 1989
Filed: Apr 13, 1987
Inventors
Kestutis F. Petraitis
Walter Baldauf
Assignee (at issue)
The Harshaw Chemical Company
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.