Apparatus and method for measuring distortion of a visible pattern on a substrate by viewing predetermined portions thereof
US6219442A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1996 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Oct 8, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/93
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An inspection station for determining the characteristics of a visible overlay pattern on a ceramic substrate includes an electronic camera unit directed at each corner of the overlay pattern. The inspection station is calibrated using a calibration substrate having a known pattern, portions of which are viewed by the cameras. The cameras remain stationary during both the calibration process and during the subsequent inspection of one or more substrates. In a first version of the station, a holder holding the substrate in place is split into quadrants, which are moved with associated camera units to accommodate varying sizes of rectangular substrates. In a second version, a lens is added to increase the magnification of the optical path to the camera units.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.