Patent · US Expired

Method and apparatus for detecting defects along the edge of electronic media

US6816251B2 · kind B2 · utility

9Cited by
24References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 11, 2002
Grant dateNov 9, 2004
Priority date
Expiry dateOct 11, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/9506
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An electronic media edge defect detector in one form has plural light sources and detectors arranged to direct and receive deflected light from the side edge margins and outer edge margins of the electronic media. The detected light is analyzed to detect the presence of defects. Individual wafers may be raised while in a cassette and turned during the inspection without removing the wafers from the cassette.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.