Research On Track Layout Optimizating And Scheduling Of Automatic Material Handling System In Wafer Fabrication

Over the past decade,domestic semiconductor enterprises in product development,technological innovation has been a significant development.Semiconductor manufacturing technology is gradually moving to the top of the world.In recent years China has developed the wafer manufacturing industry vigorously.According to SEMI statistics,the 2017-2020 Global plan to build 62 wafer fab,of which 26 will be located in China,up to 40%.The automated Material Handling system(AMHS)design is one of the most important components in the construction of the wafer factory,the wafer factory's benefit will be affected by the track layout and operating efficiency of AMHS.Therefore,it is of great significance to study the layout of track optimization,scheduling task optimization of the AMHS,mainly includes the layout of track optimization,scheduling task matching,path optimization.(1)Optimization of AMHS track layout based on discrete event simulation.Based on the network flow model,a preliminary design layout of the workshop area is made,and the layout of the workshop area is optimized.Based on this layout,the control variable method is used to optimize the track,the number of shortcuts,the speed of the OHTs and the number of the OHTs as the research variables are compared,and the number of shortcuts,the relationship between the OHT speed,the number of the trolley and the production performance is of great reference significance for the optimal configuration of the transportation dispatch system.(2)Research on Interbay material transportation scheduling based on genetic hybrid heuristic rules.Based on workshop area layout,track optimization and system configuration,based on the method of combining genetic algorithm and heuristic rules,the genetic hybrid heuristic rule method is proposed,which has good adaptability and real time,and can deal with the assignment of transport tasks in different production periods and different working conditions.The simulation results show that the genetic hybrid heuristic rule method is effective.(3)Research on path optimization method for Interbay material transportation track.Taking into account the handling capacity,delivery time and bottleneck equipment utilization,a parallel multi-objective genetic algorithm is proposed,which optimizes the path of the OHT after task assignment,encodes the path of the OHT as a chromosome,and considers three targets for path optimization,and carries out experimental simulation,The final experimental results show that the method is effective.