High-resolution in-line metrology for roll-to-roll processing operations
US9746316B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2016 |
| Grant date | Aug 29, 2017 |
| Priority date | — |
| Expiry date | Apr 29, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A substrate is tested with an interferometer in-line in a roll-to-roll processing operation to detect defects and exclude them from further processing. A tilt is introduced in the illumination path of the interferometer to allow detection of best fringes in a selected measurement field of view (FOV) that is smaller than the camera FOV in the direction transverse to the fringes. At each acquisition frame, the measurement FOV is shifted to track the best-fringe position within the camera field of view based on irradiance acquired at the previous step. As a result, the system is able to accommodate substrate flutter and roller runout and maintain focus on the substrate that allows precise identification of defects and their isolation for subsequent processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.