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:
Feb. 17, 1987
Filed:
Apr. 05, 1985
Sheree H Wen, Mohegan Lake, NY (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
Acoustic transducers are attached to each of the drill bits which produce electrical output signals in response to the vibrations during the drilling operation. A plurality of output signal includes waveforms having an amplitude and frequency dependent upon the condition of the drill bit and the medium being drilled. The waveforms represent the acoustic signature produced by the drilling operation. A control unit simultaneously compares the acoustic signature of each of the output signals with a reference signal by comparing the waveforms to determine if an improper drill condition exits. When drilling through a multilayered workpiece such as a printed circuit board having layers of different types of materials, the acoustic transducers will produce an output signal having a sequence of waveforms representing the acoustic signatures of the sequence layers. The control unit counts the number of waveform occurrences for each particular type of layer and indicates when a predetermined level is reached. The control unit can also be programmed to stop the drilling operation upon reaching the desired layer.