Characterization of objects by means of ultrasonic waves
US6250159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1999 |
| Grant date | Jun 26, 2001 |
| Priority date | — |
| Expiry date | Apr 12, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/044
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To characterize an object (3) to be measured, for example to gauge the thickness (d.sub.7) of a layer (7) borne by a substrate (4), an ultrasonic wave (8.1) is transmitted by a measuring device (1). Echo impulses (8.2, 8.5) reflected by boundary surfaces (5, 10) of the object (3) to be measured are detected by the measuring device (1); the measuring signal is digitalised and subjected to an evolution analysis in the time domain. The evolution analysis uses an algorithm which is computation-efficient by orthogonalisation and implemented search strategy. The characteristics of the object to be measured, for example the thicknesses, are determined from the delay time differences of the echo waves (8.2, 3.5).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.