Defect detection using intermodulation signals
US4868506A · kind A · utility
22Cited by
10References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1988 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Dec 2, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/58
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In order to test conductors on substrates for current constricting defects, such as cracks, narrow conductors, line breaks and intermittent opens, a test signal combining two alternating current signals at different frequencies and direct current offset signal is applied to the conductor. Upon encountering a defect, intermodulation signals are generated and detected. The phase of the detected signal and the phase of a reference signal are compared. The difference between the phase of the two signals is indicative of the presence of a defect in the conductor. The invention has particular application for testing thin conductors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.