The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 08, 1986
Filed:
Jun. 10, 1985
Suryadevara V Babu, Potsdam, NY (US);
Joseph G Hoffarth, Binghamton, NY (US);
John A Welsh, Binghamton, NY (US);
IBM Corporation, Armonk, NY (US);
Abstract
A procedure for cleaning drilled holes in laminated workpieces such as printed electric circuit boards includes the steps of coating a cutting instrument, such as a drill bit, with a liquid tracer prior to a cutting or drilling operation. During the cutting or drilling operation, the liquid tracer becomes mixed with material such as an electrically insulating binder layer disposed between opposed metal plates of the circuit board. Any smearing of the insulation material upon exposed metal surfaces of the drilled hole contain elements of chemical compounds used in the tracer. After extraction of the drill bit from the circuit board, the board is placed in a plasma reactor wherein the metal surfaces are etched to remove any smears and debris of the insulation material found on the exposed metal surfaces. The tracer elements, such as deuterium and phosphorus are monitored in the effluent plasma of the reactor to determine when the cleaning of drilled holes in the board is completed.