Patent · US Expired

Optical system for measuring and inspecting partially transparent substrates

US6057924A · kind A · utility

14Cited by
1References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 4, 1998
Grant dateMay 2, 2000
Priority date
Expiry dateSep 4, 2018

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01B11/06
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Techniques and systems for obtaining the thickness map of a partially transparent substrate in a nondestructive optical fashion. The thickness is determined by comparing the amount of absorption by the substrate to a calibrated amount obtained from a substrate standard with a known thickness that is formed of the same material. Digital signal processing operations are performed to reduce noise and to improve resolution of the thickness map.

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