摘要 |
A remote recognition system for monitoring the progress of a plurality of batches of semiconductor wafers or memory disks through a series of processing operations based on bar code recognition technology. Each batch is placed in a carrier in which it is transported to various locations where processing operations are performed. Each carrier is provided with an optically visible bar code tag, coded to be responsive to within reading range of a bar code reader unit which transmits a modulated light beam signal to the coded bar code tag and reads and decodes the light beam reflected back and collected by an optical receiver to uniquely identify the carrier that is positioned within range of the reader unit. Information from the reader units to permit monitoring the progress of semiconductor wafer or memory disk batches through multiple processing operations is received by further control apparatus. The novel bar coded carrier for use with this remote recognition system uses a bar code tag encapsulated in an external wall of the carrier, so that the bar code tag is protected from harsh chemical environments encountered by the process carrier while it remains readable by the various bar code reader units.
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