UNIVERSAL ALIGNMENT BASE FOR WAFER TRANSFER CASSETTE

Publishing Venue

Motorola

Related People

Abstract

A carrier for Silicon wafers that is used as a magazine to store, transport or process wafers through semi-automatic processing equipment is commonly termed a "cassette". A cassette can hold many wafers, e.g., 20 to 50 at one time. During normal wafer processing, wafers frequently need to be transferred from one cassette (e.g., full of wafers) to another say cleaner cassette, or one made of a different material (e.g., an empty cassette). Most wafer transfer mechanisms use a pneumatic pusher or arm to actually move the individual wafers between cassettes.

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MOTOROLA INC. Technical Developments Volume 13 July 1991

UNIVERSAL ALIGNMENT BASE FOR WAFER TRANSFER CASSETTE

by Josephine Harbarger and Frank Patrick

THE PROBLEM

  A carrier for Silicon wafers that is used as a magazine to store, transport or process wafers through semi-automatic processing equipment is commonly termed a "cassette". A cassette can hold many wafers,
e.g., 20 to 50 at one time. During normal wafer

processing, wafers frequently need to be transferred from one cassette (e.g., full of wafers) to another say cleaner cassette, or one made of a different material
(e.g., an empty cassette). Most wafer transfer

mechanisms use a pneumatic pusher or arm to actually move the individual wafers between cassettes.

  Cassette dimensions vary in a direct relationship to the diameters of the wafers to be handled. Often within a wafer manufacturing area, several diameters of wafers are processed on a routine basis. Up to now, this has required a transfer cassette for each wafer diameter, frequently at each operation. This is costly and results in manufacturing inefficiencies.

THE SOLUTION

An improved wafer transfer cassette method has been developed that can efficiently transfer wafers

with diameters ranging from 75 mm to 203 mm using just one improved transfer base.

  This new transfer base (see Figure 1) employs locating pins to properly align the cassette. There are pins positioned to accept any standard cassette size. The transfer bar spacers (Figure 2) has slots...