Air bearing piston assembly for semiconductor mask-to-wafer aligner
US3969004A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 1974 |
| Grant date | Jul 13, 1976 |
| Priority date | — |
| Expiry date | Aug 2, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG12B5/00
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An air bearing piston assembly for semiconductor mask-to-wafer aligner which utilizes a plurality of air bearings to produce a very low friction and a very predictable force system for bringing a mask into contact and level with a semiconductor wafer. Two small driver pistons are employed to move a main piston. An outside air bearing between a rotation clamp ring and the main piston and an inside air bearing between a piston guide and the main piston produce an almost frictionless system. A third air bearing is established between a leveling ball and the ball table so that the wafer with the chunk can level accurately with a minimum of force against the mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.