Automatic high speed optical inspection system
US5131755A · kind A · utility
Inventors
Key dates
| Filing date | Oct 31, 1989 |
| Grant date | Jul 21, 1992 |
| Priority date | — |
| Expiry date | Oct 31, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/06126
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In each configuration, at least one TDI sensor is used to image substrate portions of interest, with those portions illuminated with substantially uniform illumination. In one configuration, a substrate is compared to prestored expected characteristic features. In a second configuration, first and second patterns in a region of the surface of at least one substrate are inspected by comparing one pattern against the other and noting whether they agree with each other. This is accomplished by illuminating the two patterns, imaging the first pattern and storing its characteristics in a temporary memory, then imaging the second pattern and comparing it to the stored characteristics from the temporary memory. Then the comparisons continue sequentially with the second pattern becoming the first pattern in the next imaging/comparison sequence against a new second pattern. Each time the comparison is performed, it is noted whether or not there has been agreement between the two patterns and which two patterns where compared. This inspection technique is useful for doing die-to-die inspections. A variation of the second configuration uses two TDI sensors to simultaneously image the first an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.