Polishing pad with built-in optical sensor
US6485354B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 9, 2000 |
| Grant date | Nov 26, 2002 |
| Priority date | — |
| Expiry date | Oct 2, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/12
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An optical sensor that includes a light source and a detector is located within a cavity in a polishing pad so as to face the surface that is being polished. Light from the light source is reflected from the surface being polished and the reflected light is detected by the detector. The electrical signal produced by the detector is conducted to a hub located at the central aperture of the polishing pad. The disposable polishing pad is removably connected, both mechanically and electrically to the hub. The hub contains electronic circuitry that is concerned with supplying power to the optical sensor and with transmitting the electrical signal to a non-rotating station. Several techniques are described for accomplishing these tasks. The system permits continuous monitoring of an optical characteristic of a surface that is being polished, even while the polishing machine is in operation, and permits the end point of the polishing process to be determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.