有效降低黃光區多機群生產週期時間之二階段派工法則

An Effective Two Stage Dispatching Rule for Cycle Time Reduction in Photolithography Area with Multi-Workstation

顏笠淵(Li-Yuan Yen)

指導教授 ： 張國浩

國立清華大學/工學院/工業工程與工程管理學系/碩士(2012年)

https://doi.org/10.6843/NTHU.2012.00278

摘要

一般來說，在半導體產業裡，平均生產週期時間是一項很重要的績效指標，如果能保持較低的週期時間，對於半導體廠有較好的競爭力。由於黃光區機台較其他製程機台昂貴許多以及黃光區的製程特性等原因，黃光區多大扮演著瓶頸站的角色，因此，若能降低黃光區的平均生產週期時間，相信可以提升半導體廠之競爭力。然而在許多現存的半導體廠每天需要處理許多不同種類的產品，因應產品種類的不同、製程技術需求的差異，所需要的機台型號與能力也不盡相同，為滿足產品需求，在黃光區中總有著許多種類的機台。因此，如何以較佳的派工方法，平衡各機器族間之負荷，減少升降溫所需要的前置時間，進而降低生產週期時間將是本篇考量之重點。本篇論文提出一二階段派工法則，在第一個階段，利用一個啟發式演算法處理機台負荷平衡的問題，在第二階段，利用最小前置時間的準則處理升降溫所造成的前置問題。經由實際資料之收集，建構出模擬系統，並透過模擬系統評估現有派工法則與建議派工法則績效指標之差異，經由數值比較之結果發現，在不同情境下分別有7%到10%的改善幅度。最後，我們根據三種情境下的模擬結果，進一步去了解生產週期時間與來到率及情境間的關係。

關鍵字

黃光區 ； 派工法則 ； 負荷平衡 ； 模擬系統

並列摘要

In the semiconductor industry, mean cycle time is usually one of the key perfor-mance measures used by fabrication facilities to maintain their competitive advantage. As the machine in the photolithography area is more expensive than that in other areas, photolithography is usually a bottleneck area that significantly affects mean cycle time performance. Because of multiple production processes and their respective re-quirements and routings (e.g., precision requirements in alignment), multiple work-stations are present in photolithography areas. So, how to balance the workload among machines and how to reduce the setup time for changing the temperature groups are the important factors to reduce the mean cycle time. In this study, a two-stage dispatching rule for photolithography areas is proposed. In the first stage, a heuristic method for balancing workloads is developed, in which the machine with the lowest current and waiting workload is used. In the second stage, the heuristic rule is derived based on the concept of the smallest setup time for a sequence dependent setup time problem. Numerical studies show that with different scenarios, the two-stage dispatching rule can reduce the mean cycle time from 7% to 10% compared with cur-rent practice. Finally, according to the simulation result in different scenarios, we would discuss about the relationship among mean cycle time, arrival rate, and differ-ent scenarios.

並列關鍵字

Photolithography ； Dispatching rules ； Workload balance ； Simulation

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