Material thickness measurement method and apparatus
US6837109B2 · kind B2 · utility
17Cited by
3References
8Claims
0Family size
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Key dates
| Filing date | Nov 5, 2002 |
| Grant date | Jan 4, 2005 |
| Priority date | — |
| Expiry date | Jul 26, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B17/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Longitudinal and shear ultrasonic waves are generated inside a material by irradiating a laser beam onto a first surface, e.g., incident surface, of the material. An ultrasonic longitudinal wave and a mode converted wave reflected by a second surface, e.g., a bottom surface, of the material are detected, and times of flight of the ultrasonic longitudinal wave and the mode converted wave are measured. A thickness of the material is measured based on the times of flight and a correlation, obtained in advance, between longitudinal and shear wave velocities of the material and temperature of the material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.