Method and apparatus for optically controlling the quality of objects having a circular edge
US7576849B2 · kind B2 · utility
2Cited by
15References
28Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 16, 2005 |
| Grant date | Aug 18, 2009 |
| Priority date | — |
| Expiry date | Nov 16, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9503
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for optically testing the quality of objects such as silicon wafers which have a circular peripheral edge, wherein light is directed onto the edge region of the object, and the light radiating from the object due to reflection, refraction and/or diffraction is detected by means of a measuring unit which produces an image from the received light. Defects on and/or in the object are identified from the produced image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.