晶圓代工廠試製批量之生產管理機制

Abstract

晶圓代工廠為了爭取新訂單，經常必需生產試製批量（pilot lots）。為了縮短試製批量的生產週期時間，業界採用「預先凍結機台」的現場管理方法，亦即將後續製程使用到的數部機台刻意閒置，以等待試製批量的到達。 對於代工廠而言，在何時凍結哪一台機台的決策相當重要，然而目前很少相關的研究。本篇論文主要的目的在於發展一凍結機台方式，使晶圓產出最多，同時又可以滿足試製批量生產週期時間的上限。吾人將此一問題構建成分配資源的問題：把試製批量生產週期時間裡可以容許的等待時間當作資源，將它以最佳的方式分配在生產週期時間的各個時段裡。最後發展三種凍結法則，並且以摸擬的方式展現其結果，同時進行比較。

To get new orders, IC foundries have to produce pilot lots for IC design houses. To reduce the production cycle time of pilot lots, a machine frozen strategy is generally adopted in industry. That is, a machine, when frozen for a particular pilot, should not process any lots until the pilot lot arrives. The decision-making of when and which machine to freeze is very important for a foundry; yet, rare research is found in literature. This research aims to develop a machine-frozen method to maximize the wafer throughput and meet the upper bound constraints of pilot lot cycle time. This problem is formulated as a resource-allocation problem. That is, the allowable waiting time for a pilot lot is taken as resource and should be optimally placed in some time intervals of its total cycle time. Three machine-frozen rules are developed and compared by a simulation program.