The Construction of Production Planning System for Integrating Wafer Fabrication and Probing Process
Dr. Shu-Hsing Chung
|關鍵字:||多廠規劃;晶圓針測;製程規格能力;生產排程;multi-site planning;wafer probing;process capability;production scheduling|
Following the development of semiconductor industry, an enterprise will establish a new factory or merge others to get enough capacity for satisfying the customers’ order needs. The production planning of an enterprise thus is extended for cooperating with others. At the same time, there is a trend to integrate the up-stream and down-stream semiconductor factories for achieving the mission of producing final products. This study will focus on wafer fabrication and probing process and will develop an efficient production planning system for planning the product type and production quantity produced at each factory in each stage. The thesis proposes two mechanisms. The first is basically applying the production planning system for the wafer fabrication by Lai . With this mechanism, according to the throughput plan of the enterprise, we derive product mix at each site with the considerations of the capacity limitation of each fab site, profits of each generation in order to suit the performance of leveled utilization rate and cycle time. Next, based on the estimated cycle time, we can predict the due date of each order that is an input data for the production planning system of probing process. The production planning mechanism for the wafer probing factory aggregates planning results of wafer fabrication, such as predicted due date of each order, throughput target of each product type, capacity supply and capability constraints of every workstation. The load resulted from each capability type is allocated to each probing factory with load leveling consideration. With this result, this thesis then assign job-order of each product type to the workstation that can provide corresponding capability, in order to not only fulfill goal of leveled utilization rate but also have competitive cycle time. Simulation result shows that the proposed production planning mechanisms can quickly derive the product type and corresponding quantities that each wafer fabrication should produce. Also the allocation of job orders to wafer probing factories can achieve the goal of leveled utilization rate among workcenters in a factory and can maintain competitive production cycle time. Such results can provide information to managers about how to process order accept ion and to set due date.