晶圓製造廠內具時間限制的生產線段之現場管控模式

Shop Floor Control Model of Wafer Fabrication for a Segment Process with Time Constraint

杜瑩美(Ying-Mei Tu) ； 黃英鈺(Yin-Yu Huang) ； 陳欣男(Hsin-Han Chen)

《中華管理學報》 11卷1期 (2010/03) Pp. 1-22

https://doi.org/10.30053/CHJM.201003.0001

摘要

晶圓製造為一種資本密集、製程複雜且競爭相當激烈之產業，但在如此複雜的製造環境中，卻始終具有時間限制(Time Constraint, TC)之特殊現象。受此因素影響，對於具時間限制之機台的管控就變得極為困難。有鑑於此，本研究提出一套針對時間限制機台向上游機台叫料之現場管控模式。此現場管控模式將利用(S, s)存貨理論概念，於此段生產線內決定一合適之WIP範圍，當WIP高於上限(S)時阻隔上游繼續投料，而當WIP低於下限(s)時則對上游叫料。由於機台閒置主要受上游當機所影響，於是吾人利用期望產能損失時間佐以其服務率求出期望損失產能，再以管理者信心水準修正，進而求算出避免末端瓶頸閒置之存量下限。另外，求出時間限制內之期望損失產能，然後以此參數配合瓶頸站之負荷能力，推算WIP存量上限值。晶圓廠若能依此模式發展出投料控制機制，將可使現場人員不再空憑經驗即決定下料與否，而能對投料時機有所依循，如此便可大幅提升機台效率、避免晶圓報廢及降低管理爭議。

關鍵字

晶圓製造 ； 時間限制 ； 在製品 ； 現場管控模式

並列摘要

Recently, wafer fabrication has become more complicated and lengthening the product queue time. To ensure final product yield, engineers need to set up queue time limits for particular machines. There is no doubt that time constraint will influence the manufacturing efficiency which is a new challenge to wafer fabrication.
A shop floor control model is developed in this work to solve the time constraints issues within a segment process. The concept of (S, s) policy is applied in the shop floor control rules. By this control model, the WIP (Working In Process) will be protected from over queue time by the upper bond of inventory, and the machine will avoid starvation by lower bond of it. Furthermore, a simulation model is established to validate the effectiveness of this control model. It reveals the system can get a good performance both on the idle rate of equipment and scrap rate of products.

並列關鍵字

Wafer Fabrication ； Time Constraint ； Working In Process ； Shop Floor Control