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Introducing Air onto a Self Centering Air Cushion Transport Means

IP.com Disclosure Number: IPCOM000088607D
Original Publication Date: 1977-Jul-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Raacke, KH: AUTHOR

Abstract

Fig. 1 illustrates the known method of introducing low pressure air on a self-centering air track used for the transport of workpieces such as semiconductor wafers. At 1 is shown the air inlet angle onto an air track 2 and the dissipation of air under a semiconductor silicon wafer 3. It is discernable that air vectors of forces are such to completely eliminate a shear force effect. The vector 4 tends to lift the work-piece and create a "wobble", and tends to make the piece travel off center. The angle of air entrance to the track under these circumstances is approximately 9 degrees.

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Introducing Air onto a Self Centering Air Cushion Transport Means

Fig. 1 illustrates the known method of introducing low pressure air on a self- centering air track used for the transport of workpieces such as semiconductor wafers. At 1 is shown the air inlet angle onto an air track 2 and the dissipation of air under a semiconductor silicon wafer 3. It is discernable that air vectors of forces are such to completely eliminate a shear force effect. The vector 4 tends to lift the work-piece and create a "wobble", and tends to make the piece travel off center. The angle of air entrance to the track under these circumstances is approximately 9 degrees.

Fig. 2 illustrates a technique whereby the angle of air entrance 5 onto an air cushion track 2 is maintained at approximately 1 degree, thereby forming a substantially complete shear vector of air forces entering the track 6 beneath the workpiece, e.g., semiconductor wafer 7. This feature maintains a centered wafer on the track as well as eliminates "wobble".

An additional feature is to incorporate adjustable segments 8 and 8a which are moveable vertically by adjustment screws 9. The adjustment of these segments, in turn, adjusts the angle of air entrance 5 which should preferably be maintained between 1 degree and 3 degrees.

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