Method and device for checking a bond between two substrates
US11054402B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2017 |
| Grant date | Jul 6, 2021 |
| Priority date | — |
| Expiry date | May 23, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/267
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method for checking an assembly comprising first (W1) and second (W2) joined substrates, comprising the following steps: a) transmitting an ultrasonic excitation signal towards the assembly by means of an ultrasonic transducer (301) located on the front face (A1) side of the first substrate (W1); b) measuring, using the transducer (301), an ultrasonic feedback signal including at least one echo (EF) of the excitation signal on the rear face (B2) of the second substrate (W2); c) calculating, using a processing circuit (303), a spectral signal representative of the change in frequency of an overall reflection coefficient of the assembly, defined as the ratio between the feedback signal measured in step b) and the excitation signal; and d) deriving, from said spectral signal, information relating to the quality of the bond between the first (W1) and second (W2) substrates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.