Method and apparatus for detection of defects using thermal stimulation
US6840667B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2003 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Apr 18, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N25/72
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for inspecting an object and detecting defects is taught (BGA and Flip-Chip solder joints on a PCB particularly). The method comprises injecting a thermal stimulation on the object; capturing a sequence of consecutive infrared images of the object to record heat diffusion resulting from the heat pulse; comparing the heat diffusion on said object to a reference; and determining whether the object comprises any defects. Also described is a system comprising a mounting for mounting the object; a thermal stimulation module for applying a thermal stimulation to the bottom surface of the object; an infrared camera for capturing infrared images of the object on the top surface of the object to record a change in infrared radiation from the top surface resulting from the thermal stimulation; and a computer for comparing the change in infrared radiation within a region on the top surface to a reference and determining whether the object comprises any defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.