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Dual Fingered Wafer Positioning Tool

IP.com Disclosure Number: IPCOM000086676D
Original Publication Date: 1976-Oct-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 102K

Publishing Venue

IBM

Related People

Lipp, J: AUTHOR [+2]

Abstract

Shown is an improvement in the wafer centering device described in the IBM Technical Disclosure Bulletin, January 1975, Vol. 17, No. 8, page 2334. The improvement adapts the device to the handling of different sized wafers.

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Dual Fingered Wafer Positioning Tool

Shown is an improvement in the wafer centering device described in the IBM Technical Disclosure Bulletin, January 1975, Vol. 17, No. 8, page 2334. The improvement adapts the device to the handling of different sized wafers.

The improvement involves the use of offset pairs of rollers 6 and 7 (Figs. 1 and 2) which clamp either wafers 1 or 2 against a wafer notch-locating pin 30. The rollers 6 and 7 are mounted in offset relation to each other. A yoke 8 is spring loaded 9 and pivots below the wafer plane. An adjustment screw 10 regulates the spring tension to set the clamping force, as required.

The roller set 6 is mounted on yoke 8 at an angle relative to roller set 7. These angles are chosen so as to insure nominal perpendicularity between the roller and the wafer at the alignment position. Perpendicularity is important to prevent the rollers from exerting forces that would either tend to lift or press down a wafer relative to the chuck-registration surface.

Yoke 8 includes two bearings 11 and a shaft 12 that is mounted on two bearing blocks 4 and 5, free to pivot. Shaft 12 is preloaded and clamped at one end by a jack screw 13 (Fig. 3) that adjusts the wafer position angle by traversing in a direction perpendicular to the notch-pin center line. This adjustment is done with a 3.25 inch diameter master wafer. Approximately at the center of yoke 8, a locator bracket 14, including the locator screw 15, is fastened by two screws 16...