Browse Prior Art Database

Vertical Cassette-To-Cassette Random-Access Wafer Handler

IP.com Disclosure Number: IPCOM000039372D
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Del Puerto, SE: AUTHOR [+4]

Abstract

A vertical transporter for handling semiconductor wafers has been proposed in place of the horizontal type. The new transporter makes it possible to move the wafers with minimum edge contact and backside handling. Most commercial cassette loaders and unloaders can contribute to wafer contamination because of horizontal transport on O-ring belts or roller drives. Typically, such tools have cassette elevators that align a desired slot in the cassette to a transport mechanism consisting of O-ring belts, rollers, or air tracks plus pick and place assemblies which handle the wafer. This type of handling leads to contamination and breakage of the wafers.

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Vertical Cassette-To-Cassette Random-Access Wafer Handler

A vertical transporter for handling semiconductor wafers has been proposed in place of the horizontal type. The new transporter makes it possible to move the wafers with minimum edge contact and backside handling. Most commercial cassette loaders and unloaders can contribute to wafer contamination because of horizontal transport on O-ring belts or roller drives. Typically, such tools have cassette elevators that align a desired slot in the cassette to a transport mechanism consisting of O-ring belts, rollers, or air tracks plus pick and place assemblies which handle the wafer. This type of handling leads to contamination and breakage of the wafers.

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The proposal suggests maintaining the wafers in a vertical position and in a vertical laminar flow environment whereby they will accumulate fewer contaminants as well as be positioned securely during transport with less possibility of breakage. The tool developed to transport the wafer in a vertical mode is a computer-controlled, electro-mechanical-pneumatic mechanism. The wafer-lifting mechanism 1 (Fig. 1) is indexed by linear drive to the wafer 2 to be picked up. Jaws 3 (Fig. 2) close in on the wafer, centering it in the slot of the cassette 4. The wafer lifting mechanism 1 (Fig. 3) is moved upward in a vertical direction so as to lift the wafer out of the cassette 4. A vacuum pencil 5 is rotated so as to contact the back of the wafer and hold...