Granted Patent
Utility
US 4,588,421 · App. 06/736,056
Aqueous silica compositions for polishing silicon wafers
Inventor:
Charles C. Payne
Patented Case
View Patent ↗
Granted: May 13, 1986
Filed: May 20, 1985
Inventor
Charles C. Payne
Assignee (at issue)
Nalco 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.