Integrated circuit (IC) wafer fabrication systems can be characterized as discrete event systems. Petri nets are tools that have been successfully used to model and analyze such systems. This paper reports a project of applying Petri net methodologies to detailed modeling, qualitative analysis, and performance evaluation of the etching area in a real-world IC wafer fabrication system located in Taiwan's Hsinchu Science-Based Industrial Park, To tackle the problem of building a large and complex system model, a synthesis technique is used. The resultant extended net model is checked for important qualitative properties in manufacturing. A simple control policy for deadlock prevention is proposed. To obtain performance measures, simulation is used. The simulation result shows that except a small number of machines, the errors between the simulated and actual utilizations are less than 5%, The validated model can be used to answer many “what-if” questions, such as predicting the maximal throughput and bottleneck machines 相似文献
The copper(I) bromide‐catalyzed intermolecular dehydrogenative amidation of arenes via C H bond activation assisted by a 2‐pyridyl or 1‐pyrazolyl chelating group using air as the terminal oxidant has been achieved at 140 °C. N‐Aryl amides, N‐alkyl amides, benzamide derivatives, imides, and lactams all are good coupling partners to obtain moderate to excellent yields. The amount of solvent is critical for the transformation: both increasing and decreasing the amount of solvent decreased the yield. Notably, the amidation of bimolecular 2‐phenylpyridine with the dual N H bonds of a primary amide proceeded smoothly in one‐pot to afford a good yield under the same conditions. The amidation can be performed with a good yield at the gram scale.
