Ultrasonic spectroscopy apparatus for determining thickness and other properties of multilayer structures
US6397680B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2000 |
| Grant date | Jun 4, 2002 |
| Priority date | — |
| Expiry date | Aug 3, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/102
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic apparatus and method based on location of resonance frequencies is provided for determining unknown parameters in a multilayer structure, such as thickness, elastic properties of individual layers, or bonding strength between layers. Predicted resonance frequencies are obtained from the roots of a characteristic equation describing the multilayer structure. The predicted resonance frequencies are compared using a best-fit technique with the measured resonance frequencies to obtain the desired parameter. The method is of particular interest when ultrasound is generated by a laser and detected by either a contact ultrasonic transducer or a laser interferometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.