在TFT-LCD廠的設施佈置與自動化物料搬運系統控制之研究

A Study on the Facilities Layout and the Control of Automated Material Handling Systems in a TFT-LCD Plant

蘇騰昇(Teng-Sheng Su)

指導教授 ： 何應欽

國立中央大學/管理學院/工業管理研究所/博士(2012年)

摘要

對TFT-LCD（thin-film transistor liquid-crystal display）公司而言，擁有一座TFT-LCD廠是一項非常昂貴的投資。因此，「如何增加TFT-LCD廠的生產效率」對公司的經營者是一個非常重要的議題，而「TFT-LCD廠內的物料流動效率」是影響TFT-LCD廠之生產效率的一個關鍵因素。影響「TFT-LCD廠內的物料流動效率」的因素有許多，其中兩項重要因素為「TFT-LCD廠Bay內（intra-bay）的設施佈置」與「TFT-LCD廠Bay內自動化物料搬運系統（Automated Material Handling System；AMHS）的派送控制」。不同於晶圓廠的Bay內物料搬運方式，在TFT-LCD廠內常見的一種Bay內物料搬運方式是將Stocker一直延伸到Bay內，並且於Stocker的封閉式空間內，利用Stocker內部的stacker crane（S/R machine）將物料於機器與儲位之間做運送。換言之，此種Stocker系統不僅有儲存的功能也有運送的功能。在業界，此種Stocker系統被稱為Stocker Direct Handling System（又稱為In-Line Stocker）。另外，有些TFT-LCD廠也利用RGV（Rail-Guided Vehicle）來輔助In-Line Stocker進行Bay內的物料搬運。換言之，TFT-LCD廠Bay內AMHS的設置型態也可能會不同。由於，TFT-LCD廠Bay內之特殊的物料搬運方式與其Bay內AMHS的不同設置型態，TFT-LCD廠Bay內的設施佈置問題將不同於一般晶圓廠Bay內的設施佈置問題。本文第一部份首先研究在具多stacker crane的In-Line Stocker之TFT-LCD廠Bay內的機器佈置問題。而且，我們也將在具In-Line Stocker系統與RGV系統的TFT-LCD 廠Bay 內的機器佈置問題加以探討。因為In-Line Stocker裡多stacker crane的設計，當解決TFT-LCD廠Bay內的機器佈置，我們不僅需決定機器位置，還有區域分割的設計。目的包含總流量距離的極小化，還有stacker crane之間的工作負荷平衡。我們提出一套採用啟發式與數學方法的佈置程序，以用來輔助我們完成上述任務。我們將求解一個模仿真實案例問題，來說明所提出的佈置程序。最後，透過模擬實驗與比較結果證明提出的佈置方法，是有能力產生一個可行且好的TFT-LCD廠Bay內的機器佈置。本文第二部份的研究主題是在In-Line Stocker裡stacker crane之控制問題研究，並且定義三種stacker crane的控制問題及分別針對每個問題發展控制規則。這三種問題分別是task-determination問題、port-clearing 問題及cassette-delivery問題。接著建立電腦模擬分別比較這三種問題所提出的控制規則的績效。本文的目的是想藉由對這兩類問題的探討與研究，來提升TFT-LCD廠Bay內的物料流動效率，進而改善TFT-LCD廠的生產效率、降低其生產成本與提升其競爭力。

關鍵字

模擬技術 ； 具內嵌式自動倉儲 ； 機器佈置問題 ； TFT-LCD廠區 ； 派送控制 ； 存取機 ； 軌道式搬運車

並列摘要

Building a thin-film transistor liquid-crystal display (TFT-LCD) plant is a huge investment, thus it is very important to increase the production efficiency of a TFT-LCD plant. One important factor that affects a TFT-LCD plant’s production efficiency is the plant’s material flow efficiency. Many factors can affect a TFT-LCD plant’s material flow efficiency. Among them, a TFT-LCD plant’s intra-bay facility layout and the dispatching control of the plant’s intra-bay automated material handling systems (AMHSs) are two critical ones. The way that material is handled in a TFT-LCD bay is different from that in a wafer-fab bay. The stocker of a wafer-fab bay is located at one end of the bay and only provides the storage function. However, the stocker of a TFT-LCD bay is extended all the way into the bay. Furthermore, the stocker of a TFT-LCD bay not only has the storage function, but also can transport cassettes between machines, ports and storage cells. This type of stocker is referred to as ‘stocker direct handling system’ also known as ‘in-line stocker.’ In some TFT-LCD plants, rail guided vehicles (RGVs) are also used to assist in-line stocker transporting cassettes. The unique way that an in-line stocker handles cassettes and the possible presence of RGVs have made the layout problem of a TFT-LCD bay different from that of a wafer-fab bay. In the first part of this paper, we study the machine layout problem in a TFT-LCD bay with a multiple-stacker crane in-line stocker. Furthermore, the machine layout within a TFT-LCD bay with an in-line stocker system and an RGV system is further investigated. Due to its multiple-zone in-line stocker, solving a TFT-LCD bay’s machine layout requires us to determine not only the positions of the machines, but also the zone division design. The objectives include the minimization of total flow distance and the workload balance between stacker cranes. We propose a layout procedure that adopts heuristic and mathematical approaches to assist us in accomplishing the aforementioned tasks. An example problem mimicking a real-case problem was solved to illustrate the proposed layout procedure. The simulation and comparison results demonstrate the capability of the proposed layout method in producing a feasible and good machine layout in a TFT-LCD bay. In the second part of this paper, we study the dispatching control problem of the stacker cranes of in-line stockers by identifying three control problems of stacker cranes and developing control rules for each of them. These three problems are task-determination problem, the port-clearing problem, and the cassette-delivery problem. Computer simulations were conducted to compare the performance of the rules proposed for each of these three problems. The objective of this paper is to optimize the material flow efficiency within a TFT-LCD bay. By doing so, it is hoped that the TFT-LCD plant’s operational efficiency can be improved, its production cost can be reduced and its competitiveness can be increased.

並列關鍵字

Dispatching Control ； Simulation Technique ； Machine Layout Problem ； TFT-LCD Bay ； Rail Guided Vehicle ； Stacker Crane ； In-Line Stocker

參考文獻

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