A Full Factory Transient Simulation Model for the Analysis of Expected Performance in a Transition Period
Intel's Fab-18 is based in Israel, and has transitioned from producing 0.18-micron logic devices to producing 90 nM flash products. During this transition period, the factory has de-ramped in volume of logic while ramping-up flash. AutoSched AP software was utilized for the development of a transient simulation model of the Fab's behavior during this period. It is the first attempt, at Intel, to utilize a full factory simulation in order to analyze and support decisions that pertain to a transient period of parallel de-ramp and ramp-up of technologies. Unlike typical simulation models for the analysis of factory performance and behavior in steady-state, the transient model poses several modeling challenges and requires major adjustments in dealing with these challenges. In this paper, we discuss those aspects. The benefits and contribution of such a model to decision making and the improvement of factory performance are also presented
Development of Manufacturing Simulation Model for Semiconductor Fabrication
This research presents the development of simulation modeling for WIP management in semiconductor fabrication. Manufacturing simulation modeling is needed for productivity optimization analysis due to the complex process flows involved more than 35 percent re-entrance processing steps more than 15 times at same equipment. Furthermore, semiconductor fabrication required to produce high product mixed with total processing steps varies from 300 to 800 steps and cycle time between 30 to 70 days. Besides the complexity, expansive wafer cost that potentially impact the company profits margin once miss due date is another motivation to explore options to experiment any analysis using simulation modeling. In this paper, the simulation model is developed using existing commercial software platform AutoSched AP, with customized integration with Manufacturing Execution Systems (MES) and Advanced Productivity Family (APF) for data collections used to configure the model parameters and data source. Model parameters such as processing steps cycle time, equipment performance, handling time, efficiency of operator are collected through this customization. Once the parameters are validated, few customizations are made to ensure the prior model is executed. The accuracy for the simulation model is validated with the actual output per day for all equipments. The comparison analysis from result of the simulation model compared to actual for achieved 95 percent accuracy for 30 days. This model later was used to perform various what if analysis to understand impacts on cycle time and overall output. By using this simulation model, complex manufacturing environment like semiconductor fabrication (fab) now have alternative source of validation for any new requirements impact analysis. Keywords—Advanced Productivity Family (APF), Complementary Metal Oxide Semiconductor (CMOS), Manufacturing Execution Systems (MES), Work In Progress (WIP).
Knocking in an Internal-Combustion Engine
The question remains open of the relation between the phenomena of knocking in the engine and the explosion wave. The solution of this problem is the object of this paper. The tests were conducted on an aircraft engine with a pyrex glass window in the cylinder head. Photographs were then taken of various combinations of fuels and conditions.