Electro-magnetic alignment device
US4485339A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1983 |
| Grant date | Nov 27, 1984 |
| 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 devices, which are particularly adapted, among other possible uses, for use in aligning the wafers in a microlithography system, said devices comprising in combination a base plate, a first current carrying coil assembly mounted on the base plate, a second current carrying coil assembly mounted on the base plate in spaced relationship with respect to the first coil assembly, a first magnet mounted adjacent the first coil assembly and a second magnet mounted adjacent the second coil assembly, an upper connecting piece connecting the first and second magnets, a mount for receiving an object on the upper connecting piece, the base plate and magnets and upper connecting piece coacting to form a magnetic circuit, a controller for controlling the flow and direction of current through the coil assemblies to move the magnets and upper connecting piece with respect to the base plate, a plurality of linear actuators mounted between the magnets and the upper connecting piece respectively for moving the connecting piece with respect to the magnets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.