Electro-magnetic apparatus
US4506204A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1983 |
| Grant date | Mar 19, 1985 |
| Priority date | — |
| Expiry date | Jun 10, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2201/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention is directed to electro-magnetic alignment apparatus, which is particularly adapted, among many other possible uses, for use in aligning the wafers in a microlithography system, said apparatus including in combination at least three magnet assemblies which are mounted in space relationship one with respect to the others, at least three coil assemblies mounted to pass through the high flux region of the magnet assemblies respectively, the width of the coil assemblies being substantially less than the width of the high flux regions respectively, a controller for controlling the flow of current through the coil assemblies respectively, a structural assembly for connecting the coil assemblies which is movable with respect to the magnet assemblies, the coil assemblies being wound with respect to each other so that by controlling the supply of current to the coils the structure assembly can be moved selectively in three degrees of freedom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.