Substrate thickness determination
US6710890B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2003 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Feb 26, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0608
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for measuring a thickness of a substrate having an upper surface, without contacting the upper surface of the substrate. A platen having a base surface receives the substrate, and a reference surface is disposed at a known first height from the platen surface. A non contact sensor senses the known first height of the reference surface without making physical contact with the reference surface. The non contact sensor further senses a relative difference between the known first height of the reference surface and a second height of the upper surface of the substrate without making physical contact with the upper surface of the substrate. A controller controls the sensor and determines the thickness of the substrate based at least in part on the known first height of the reference surface and the relative difference between the known first height of the reference surface and the second height of the upper surface of the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.