Device for holding a mask
US4963921A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1989 |
| Grant date | Oct 16, 1990 |
| Priority date | — |
| Expiry date | Feb 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/707
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A device for detachably holding a mask at least a portion of which is made of a magnetic material. The device includes a holding member, on which the mask is to be held, the holding member having a portion made of a magnetic material; a first system for producing holding magnetic lines of force so as to generate a magnetic force between the magnetic portion of the holding member and the magnetic portion of the mask, to thereby hold the mask on the holding member; and a second system for producing releasing magnetic lines of force which are operative against the magnetic lines of force produced by the first system so as to reduce the same to a degree sufficient to disengage the mask from the holding member. Also, disclosed is a mask holding device for detachably holding a mask, typically for use in the manufacture of microcircuits, which device is arranged to hold the mask by use of a magnetically attracting force, the magnetically attracting force being made variably controllable so as to correct the flatness of the mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.