Pattern inspection system
US4830497A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1987 |
| Grant date | May 16, 1989 |
| Priority date | — |
| Expiry date | May 11, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30172
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved pattern inspection system for automatically inspecting patterns on a printed circuit board, a semiconductor chip, etc. The pattern inspection system includes an optical sensor, a binary conversion circuit, a memory storing binary converted data in a matrix form, a length measurement circuit, a reference circuit and a determination circuit. The length measurement circuit includes a gate unit for picking-up the binary converted data array from the memory in radial directions with respect to an origin and for a predetermined length in each direction, a unit for measuring radii of the pattern in the radial directions from the origin in response to the picked-up binary converted data, a unit for determining a center line of the pattern in the picked-up binary converted data array by the measured length of the first directions, and a unit for encoding the measured length of the second directions to numerals each corresponding to one length of each of the second directions. The reference circuit receives the coded numerals for a reference pattern and forms a coded reference in response to the coded numerals. The determination circuit receives coded numerals for a inspection pa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.