Plate-like article holding device
US4869481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1988 |
| Grant date | Sep 26, 1989 |
| Priority date | — |
| Expiry date | Jul 12, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T279/3481
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A plate-like article holding device particularly suitably usable in an exposure apparatus for printing a pattern of a reticle or mask on a semiconductor wafer, as a wafer holding device for holding the wafer at a pattern printing station, is disclosed. In an embodiment, the holding device includes a wafer chuck having a wafer attracting surface and a plurality of throughbores formed in relation to the attracting surface. Also, the device includes a plurality of support pillars provided in relation to the throughbores, respectively, and having end faces effective to support a wafer by attraction. There is provided a driving mechanism for moving the wafer chuck in a direction substantially perpendicular to the wafer attracting surface of the chuck so as to allow that the supporting end faces of the support pillars project outwardly beyond the wafer attracting surface of the wafer chuck or, alternatively, they are accommodated within the wafer chuck. A wafer having been conveyed to the device is first attracted to and supported by the supporting pillars as they are projected from the wafer attracting surface of the chuck. Thereafter, the wafer chuck is moved by the driving mechanism s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.