薄膜液晶顯示器組立廠具雙製程情境下排程系統之設計

Abstract

薄膜液晶顯示器製程組立廠負責將彩色濾光片與陣列段所產出之玻璃基板對組並加入液晶。由於製程的演進，組立段加入液晶的方式除了以原有的液晶灌入製程進行外，也研發出效率較高且速度較快的液晶滴入製程。在不浪費原有製程產能且加快生產速度的考量下，出現了新舊製程混合協同生產的方式，因此本文即針對具雙製程情境之組立廠設計排程系統。 組立廠必須分別加工玻璃基板與彩色濾光片，在力求最大化利潤的情況下，除了生產訂單式的產品外，剩餘可用產能將用於生產存貨式產品。產品具有尺寸大小、液晶種類與加工製程三種屬性，而各工作站分別依據其所考量屬性之改變而換線，因此造成換線之情境複雜；除此之外，液晶灌入製程中的批量機台存在集批等候的特性，在建構排程系統時皆須考量。 本文之排程系統首先針對訂單式產品來粗估各工作站所需之設置次數，進而計算各工作站之產能負荷並找出負荷最高的瓶頸工作站與次瓶頸工作站。接著考量次瓶頸工作站的負荷狀況、產品加工的製程與瓶頸工作站換線的屬性下，以最大化生產利潤為目標，藉由瓶頸工作站混整數規劃模式決定瓶頸工作站中各機台之排程，包括加工之產品種類、數量及順序。最後依據瓶頸工作站的規劃結果，在考量各批量工作站的批量大小限制與批量機台特性下，以盡量滿足瓶頸工作站規劃結果為目標，藉由批量工作站混整數規劃模式決定批量工作站之排程，包括批量工作站各機台之生產種類、數量及順序，並發展回饋機制來協調瓶頸工作站與批量工作站之間的排程結果，使瓶頸工作站與批量工作站能相互配合，完成本排程系統之規劃。 本文以實際數據，並分別以不同的情境驗證本排程系統，確認本系統之實用性；最後以模擬的方式確認本排程系統規劃之可行性，而藉由模擬之驗證可知本文中規劃之排程結果在模擬環境中可產出率達99.2%，證明本文設計之排程系統為實用且確實可行。

TFT-LCD cell assembly factory takes charge of assembling the glasses from array factory with the color filters, and filling up with liquid. Traditionally, the factory adopts hot press(HPS) process for filling liquid, however, a new process, named one drop fill(ODF) process, is developed currently to accelerate the speed of filling. Concerning the surplus value of HPS process and the better efficiency of ODF process, here come some factories in which two kinds of processes work in coordination. In this thesis, a master production scheduling system is designed for the factory with two kinds of processes. The assembly factory processes glasses and color filters separately and assembles the two materials into products. In order to maximize the profit, the factory will not only accept the make-to-order (MTO) products but also produce the make-to-stock (MTS) products to use up capacity. Each product has three kinds of attributes including size, liquid type and process, and every workstation takes account of different attribute to decide whether setup or not. This is complex for planning setup schedule. Besides, the batch machines used in HPS process operate only when the accumulated units of the same job type reach the predetermined level. The proposed master production scheduling system first estimates setup times which caused by the make-to-order products roughly so as to calculates capacity loading of each workstation, then defines the highest and the second high loading workstation as main bottleneck and secondary bottleneck. Considering the loading of secondary bottleneck and the attributes of products and regarding profit maximization as the target, the bottleneck scheduling model is designed to decide the product type, quantity and the production sequence on each machine of the bottleneck workstation. Then the batch scheduling model is developed to decide the product quantity and production sequence on each machine of the batch stations in order to match with the results of bottleneck scheduling. Also, a feedback mechanism is developed to ensure that no conflict exists between the scheduling of bottleneck and that of batch workstations. Several scenarios with practical data are used to verify the practicability of the master production scheduling system, and simulation is applied to confirm that the results of this scheduling system are achievable. The simulation results showed that the scheduling system in this thesis is quite functional and definitely practicable.