Released lot decisions during ramp up stage
|關鍵字:||半導體廠;良率學習;投料決策;Semiconductor;Yield learning;Released lot decisions|
For providing a competitive selling price, semiconductor manufactures continuously improve their production process to reduce manufacturing cost. A new production process is frequently introduced to the production line when its production process knowledge is ill understood for rapid product lifetime and expensive development cost. During this time, the yield of the new production process is very unstable and low. Therefore, only partial capacity is provided for the new production process for understanding its knowledge. The rate of ramp-up is influenced by yield learning of new production process. Yield in ramp-up stage is learned by two factors. One is learning by doing, the other is learning by experimentation. These two factors are generally determined by the numbers of release new production process lots. How to allocate capacity to meet customers’ demands with minimum cost is the major work in this study. We formulate a decision model to determine released lots for current and new production process during ramp-up stage to minimize total released wafer cost.
|Appears in Collections:||Thesis|