晶圓代工廠在二種生產週期時間限制下的產能估算模式

Abstract

晶圓代工市場上，對產品存在著不同交期的需求。客戶有時為了搶佔上市的時機，或為了趕上銷售的熱潮，因此希望委託代工的產品有較短的交期，也就是希望晶圓代工廠能提供生產週期時間較短的生產服務。然而，目前晶圓代工廠在面對客戶較短交期的需求時，只能將之視為緊急訂單來處理。僅能提供少量的需求，且其代價甚高。同時緊急訂單亦對已規劃之訂單影響其鉅，造成生產現場的嚴重失序。 本論文使用Pacemaker規劃軟體構建一個用於接單管理的產能估算系統，能夠規劃系統在二種生產週期時間的環境下的生產計畫；同時建構一個模擬驗證模式，使用控制產品生產週期時間的派工法，模擬此一產能估算系統的績效；最後以模擬的結果配合參數修正模式的使用，修正Pacemaker的產能參數設定，使此一模式能夠實際用於快速而準確的接單評估。

Customers of IC foundries often need various requirements in the production cycle-time. That is, new products generally demand shorter cycle time while mature products relatively can allow longer cycle time. However, IC foundries in practice only offer one cycle time deal in managing customers' orders and previous research in managing multiple cycle-time requirements is rarely found in literature. This research develops a model for estimating the wafer throughput under the constraints of meeting two cycle-time requirements. The model involves two modules. A rough-cut planning module, under some preliminary assumptions of machine utilization, is first performed to give planned throughput and the releasing schedule of wafers. In the second module, the derived releasing schedule together with a proposed dispatching strategy is adopted in a simulation program to justify the feasibility of planned throughput. If the planned throughput is infeasible, the assumptions of machine utilization should be adjusted. This adjusting procedure is repeated until the two cycle-time requirements and the planned throughput are achieved.