The Design of Material Handling System for the Modularized Wafer Fabrication Factories
Dr. Shu-Hsing Chung
|關鍵字:||晶圓製造;廠區佈置;物料搬運系統;模擬;Ｗafer Fabrication;Factility Layout;Material Handling System;Simulation|
In recent years, semiconductor industry becomes the booming industry in Taiwan. The competition between the wafer fabrication factories hence becomes more and more keen. In such environments, enhancing the throughput and delivery performance is the only way to keep the competitive superiority. Wu [32, 33] proposes the architecture for modularized, economical, flexible and automated semi-conductor factory. In this thesis, corresponding design for the plant layout, the path of material flow, the material handling system is proposed , the releasing rule for Wu's modularized wafer fab. A simulation model is built to collect its system performance. For the plant layout, this thesis contrives the facility layout to be flow line in order to reduce production cycle time, and to design the path of material flow so as to shorten material handling distance. For the material handling system, the major idea is to prevent material flow from being system bottleneck. Thus, the cycle time of the monorail traveling is set so as to fit the throughput rate of bottleneck workstation. Also, the priority for moving requests are set according to the status of bottleneck to keep material flow smooth before and after bottleneck. Finally, for the design of releasing rule, the policy of releasing six lots simultaneous is adopted to fit the feature of the batch machine. The releasing rate is set with considerations of the bottleneck's throughput rate, and then adjusted by using fixed-WIP method so as to control the WIP level and the cycle time in an acceptable range. The simulation results show that with such a design, the modularized wafer fab can reach the goal of high throughput, low production cycle time and low WIP level. Such a design makes a contribution in increasing throughput and enhancing delivery ability of the wafer fabrication factories.