晶圓製造廠在製品水準之規劃與控制

Abstract

目前國內晶圓製造業所普遍面臨的前置時間過長, 和在製品數量過高 的問題, 突顯了決定合理的在製品水準, 以及選取適當投料法則, 派工策 略的重要性. 另外, 現場機器當機所造成的產能損失, 物流阻塞等傷害, 亦為半導體廠的生管人員帶來了莫大的困擾, 而為求此難題之解決, 構建 當機因應策略更是當務之急. 本論文的主要目的, 在於將主生產排程 的期望產出目標和細部排程的規劃結果, 落實到現場控制階段, 以發展一 適用於晶圓製造廠的在製品控制模式; 同時考慮當機事件對系統整體績效 之影響, 構建可行的當機因應策略, 達到限制資源利用極大化, 並力求生 產週期時間的極小化. 吾人所發展的在製品控制模式, 係以滿足上層 規劃為目標, 並發展一在製品數量演算法則, 使其在滿足資源限制和預定 產出的條件下, 得以求算各規劃週期之期望在製品水準. 而在當機因應策 略的構建中, 則探討機器當機或修護後, 系統在細部排程規劃面所應採取 的因應措施, 並提出一調整在製品數量與分佈之啟發式方法, 藉以對各層 級的產出進行控制. 經由模擬驗證之結果說明, 透過在製品控制模式 與當機因應策略的進行, 一則可有效控制在製品的數量與分佈; 二則可使 在製品快速因應現場即時的要求, 並做合理的更動, 將可達到提升生產績 效的效果. The general problems that the wafer fabrication encounters include thetoo long lead time and too high Work-in-Process(WIP) level. These problemsremark the importance of deciding reasonable WIP level and selecting properreleasing and dispatching rules. The main purpose of this thesis thus is to fulfill the planning resultof MPS and detail scheduling to the shop flow control stage, and to developa WIP control model for wafer fabrication factories. To accomplish the goals,the expected WIP level is estimated by a proposed method with the conside-rations of satifying resource constraint and scheduled throughput. Since, machines shutdown causes the capacityy loss, and the material flowblocked. The machines shutdown response policy hence is proposed for maximi-zing the CCR's utilization and minimizing the cycle time. It discusses theprocedure that the shop flow should adopt during the machines shutdown andrepair. A heuristic method is included for adjusting the WIP level, in orderto control the output of every layer. The simulation results show the effects of applying the WIP control modeland the machines shutdown response policy. One is to control WIP level effec-tively, the other is to response the request of shop-flow immediately, andto make rational adjustment of WIP level. These effects will improve the per-formance of production.