Granted Patent
Utility
US 4,872,787 · App. 07/106,439
Method of drilling printed circuit board
Inventors:
Kunio Arai, Hiromi Nishiyama, Hiroshi Aoyama, Yasuhiko Kanaya
Patented Case
View Patent ↗
Granted: Oct 10, 1989
Filed: Oct 9, 1987
Inventors
Kunio Arai
Hiromi Nishiyama
Hiroshi Aoyama
Yasuhiko Kanaya
Assignee (at issue)
Hitachi Seiko 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.