With the increase in the size and weight of 300-mm wafers, the factory area must also be enlarged Due to the long-distance material flow, elimination of manual wafer handling has become necessary; hence an automated material handling system (AMHS) is required for a 300-mm semiconductor manufacturing facility. The design of an AMHS must not only be capable of meeting numerous complex material handling requirements, but also simplify control and reduce capacity loss. This study proposes the segmented dual-track bidirectional loop (SDTBL) design for an AMHS. The configuration is based on a double-loop flow path structure that is divided into non-overlapping segments, each containing a certain number of vehicles operating in a bidirectional mode. The transfer buffer is set to enable conversion between segments and to connect each independent zone. This structure eliminates congestion and blocking without requiring additional investment by operating vehicles on mutually exclusive tracks. The segmentation strategies and steps for two scenarios are developed in this study, and a simulation model is constructed to evaluate the performance of each segmented strategy.
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