The use of overhead buffer to improve queue time of stocker in AMHS – a case study on semiconductor foundry

• Main Authors: Feng-Ru Hsiao, 蕭鳳儒
• Other Authors: Taho Yang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/64029700250420667752

碩士 === 國立成功大學 === 工學院工程管理專班 === 97 === Semiconductor is key industry and one of two trillion and twin star industries development plan in Taiwan. It had upgraded to generation of 300mm wafer and nano-technology by customer demand and technology roadmap. The capital investment required over billions USD for single fabrication. The improvement of tool productivity will be key topic due to the increasing capital investment. The factory had reached stage of fully automation with few operators in 300mm wafer fabrication. The tool operation became automation mode and manual material handling was replaced by Automatic material handling system (AMHS) because of higher wafer yield rate and labor occupation injury issue. Therefore. The tool productivity will be impacted by AMHS operation efficiency. To improve the tool productivity. The AMHS system bottleneck will be identified as wafer stocker by AMHS transportation pattern and volume estimation in this paper. The improvement method for high utilization of wafer stocker was to apply over-head buffer (OHB) to change transportation pattern. Moreover. The benefit of OHB application will be verified with queuing theory to ensure tool productivity was improved as well.