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:
May. 05, 1987
Filed:
Feb. 10, 1986
Ralph E Dufresne, Auburn, WA (US);
Douglas A Brauns, Federal Way, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A probe that is used to determine the etch rate of a nonconductive material is comprised of a substrate of the material itself, plated on opposite sides with a conductive material. A first side of the probe has a small area of the plating removed to expose the substrate. The other side has an annular portion of the plating removed to define a wafer of plating isolated from the remainder of the plating. A lead wire is connected to the wafer and the entire second side of the probe is coated with an insulating mask. The probe is immersed in a bath of the etching solution. A voltage source is connected to the probe and to an electrode also immersed in the bath. A measurement device is connected in the circuit to detect current flow. When the etching bath dissolves the substrate through the exposed portion, a circuit is completed with the lead wire and the current flow is detected. The time from immersion of the probe to the beginning of current flow is used to calculate etch rate. Preferably the probe in constructed so that it remains in the bath in a passive state until actuated from a remote control circuit. In this manner, a plurality of probes can be placed in the bath and activated seriatim to conduct periodic etch rate measurements.