Search International and National Patent Collections

1. (WO2015047931) NONDESTRUCTIVE, ABSOLUTE DETERMINATION OF THICKNESS OF OR DEPTH IN DIELECTRIC MATERIALS

Pub. No.:    WO/2015/047931    International Application No.:    PCT/US2014/056730
Publication Date: Fri Apr 03 01:59:59 CEST 2015 International Filing Date: Tue Sep 23 01:59:59 CEST 2014
IPC: G01N 22/00
Applicants: EVISIVE, INC.
Inventors: LITTLE, Jack, R.
Title: NONDESTRUCTIVE, ABSOLUTE DETERMINATION OF THICKNESS OF OR DEPTH IN DIELECTRIC MATERIALS
Abstract:
Enhanced measurement of thickness in bulk dielectric materials is disclosed. Microwave radiation is partially reflected at interfaces where the dielectric constant changes (e.g., the back wall of a part). The reflected microwaves are combined with a portion of the outgoing beam at each of at least two separate detectors. A pair of sinusoidal or quasi-sinusoidal waves results. Thickness or depth measurement is enhanced by exploiting the phase and amplitude relationships between multiple sinusoidal or quasi-sinusoidal standing waves at detectors sharing a common microwave source. These relationships are used to determine an unambiguous relationship between the signal and the thickness or depth.