David J Riese

US Patent:

51724200, Dec 15, 1992

Filed:

May 11, 1992

Appl. No.:

7/884857

Inventors:

Rajarshi Ray - Princeton NJ
David R. Riese - Bradford MA

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

G06K 900

US Classification:

382 8

Abstract:

Inspection of a metallized pattern (14) on a substrate (12) to monitor both the lateral dimensions and the intensity variation beyond tolerance limits is carried out by first capturing the image of the pattern with a television camera (20). The captured image is then compared to each of two models (40 and 42) comprising comparison patterns whose features have their lateral dimensions eroded and dilated, respectively, and the other aspect dilated and eroded, respectively, by a factor corresponding to the dimensional and intensity tolerances. The results of such comparison are logically combined to yield an image containing only defects (if any).