晶圓廠產能利用率滿載下投線策略之探討-以A公司為例

Abstract

在景氣高峰時，客戶的需求往往高過於工廠的產能配置，為了留住客戶的訂單，增加產出量是每位管理者急於改善的主要目標，而瓶頸機台產能決定了工廠的產出量，在確保瓶頸機台可以獲得最大產出的情況下，瓶頸機台的產能損失是絕對不被容許的。但在實際生產現況中，往往因為不可預期的因素導致在製品不足，造成瓶頸機台產能損失而影響到實際產出；例如客戶不預期的停貨，或工廠因機台或製程問題、天災所造成的大規模報廢等。因此，在製品的設置與管理便相形重要，因為晶圓製造時間冗長，短則一個月長則三個月，為避免因不確定因素而影響有效產出，本研究是針對現況來擬定一有效的投料策略，目的是在瓶頸機台前設置保護產能的在製品 (Buffer WIP)，避免因不可預期之因素所造成的在製品短缺而影響瓶頸機台的產出，並且探討Buffer WIP對生產管理的影響，並透過園區某晶圓廠來驗證此投料策略的可行性及效益。

During a peak period within in a business cycle, customer demand is often higher than a factory’s installed capacity. Therefore, in order to increase more output for top management, maintaining a long term business relationship with customers is the primary improved target. However, while a bottleneck capacity determines a factory’s output, it’s not permissible to lose capacity by such. Maximum capacity must be maintained. The reality is that in production unexpected events often occur resulting in insufficient WIP, and actual output is lost due to bottleneck. For example, customers hold shipments as a result of unpredictable events or tools, process issues and natural disasters cause a great deal of wafer scraping. As a result, WIP establishment and management are getting more important. Wafer process cycle time is redundant and sometimes can waver in length; going from one month to sometimes three months. To prevent unpredictable events from affecting output, this study focuses on how to build up a reliable Wafer Start Strategy. It’s purpose is to protect Buffer WIP from losing capacity due to bottleneck tool as well as preventing unexpected events from causing WIP loss and influencing the output of bottlenecks. Furthermore, it examines the relationships between Buffer WIP and Production Management. The study will verify the feasibility and efficiency of the Wafer Start Management System’s strategy by a foundry in the Science Park.