Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Sorting And Transfer Drive Mechanism

IP.com Disclosure Number: IPCOM000102213D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17

Publishing Venue

IBM

Related People

Barenboim, M: AUTHOR [+3]

Abstract

A mechanism is described whereby parts are sorted, stored and transported during the manufacturing of circuit modules. Described is the implementation of the mechanism for use in the manipulation of silicon wafers, but the concept is not restricted to wafers, in that the concept can be implemented in a variety of similar applications.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 15% of the total text.

Sorting And Transfer Drive Mechanism

       A mechanism is described whereby parts are sorted,
stored and transported during the manufacturing of circuit modules.
Described is the implementation of the mechanism for use in the
manipulation of silicon wafers, but the concept is not restricted to
wafers, in that the concept can be implemented in a variety of
similar applications.

      In the prior art, two pick-and-place arms and a second orienter
assembly were used in the manipulation of wafers. The concept
described herein achieves the required throughput rates by using only
a single mechanism to move wafers and to read bar codes.  The sorting
and transfer drive mechanism selects and picks up a disk-shaped wafer
from a cassette, reads a bar code previously applied to the wafer and
transfers it to a new cassette location.  The individual cassettes
are identified by patterns of holes at specific locations on the
cassette.  Due to the fragility of the silicon wafer material, the
mechanism is designed to prevent contamination and damage to the
wafer and to operate in a Class 10 clean room environment.

      Fig. 4 illustrates the system mechanisms for the sorting and
transfer process.  Processing unit 53 has associated memory unit 54
in which appropriate programs are stored.  Processing unit 53 can
receive operator input by means of keyboard unit 55 and the ability
to receive external programs by means of file unit 56.  This provides
to the operator program-generated messages displayed at display unit
57.  Processing unit 53 is also attached to adapter logic unit 58
which processes signals from the sensing units and encoders within
transport mechanism 18, thereby indicating the position of the
mechanism with respect to the various slots in the cassette 11 (Fig.
2). Processing unit 53 is also attached to controller 59 which
produces signals to drive the various motors within transport
mechanism 18 and to operate valves 60.

      Fig. 1 shows a partial right end view of the mechanism for
picking and transporting wafers.  Wafers 10 are stored and
transported between process steps in slotted cassettes 11.  Front
surface 12 of wafer 10 contains the circuit patterns, while the rear
surface contains the coded bar code used to identify the particular
wafer.  An alignment flat 13 is included on the outer edge of the
wafer.  Fig. 2 shows a partial front view with wafers 10 inserted in
slots (not shown) of cassette 11. Cassette 11 is clamped onto table
14 by means of clamping device 15. Detent slots 16 are fitted in
cassette 11 so as to engage in ribs in table 14 ensuring accurate
alignment of the cassettes.  This provides a commonality for axes 17,
enabling the various cassettes to be essentially coaxial.  The
mechanism provides further orientation at an angle to assure that
each wafer is located along a known surface of an associated slot in
a cassette.

      Wafer transport mechanism 18, as shown in Fig. 1, contain...