Simulations of consecutive diffusion process
Process simulation based on virtual reality can comprehensively present the real process on the computer. It can play an important role in the development and manufacturing field of diffusion furnace. This paper researches the establishment of consecutive diffusion process and the key techniques of process simulation. In the process of creating process simulation, V code would be created to control motion of each part. A simulation that reflects on the real process could be acquired with this research. This process simulation not only shortens the development time of diffusion furnace, but also makes designer have a perspective to the defects of product in the design process. It promotes the effective of design, and reduces changes in later period of design.
Design and implementation of the control system to vacuum diffusion furnace
This paper proposed the design proposal of the control system for vacuum furnace. The control system consist of a field bus control system (FCS) based on industrial control machine, PLC, intelligent PID instrument etc. The whole system realizes four closed loop controls of three sections of the furnace, which include temperature PID control, gas flow tracking control, Push-pull boat tracking control and furnace vacuum PI control. The upper computer programming software realizes the design of all kinds of control software by using the VB.NET and Access database, which mainly complete equipment monitoring and acquisition all kinds of real-time data of industrial production, control and monitor operation situation of lower computer equipment, store the history data of equipments, download/upload production process data and generate data curves and so on, and make the operation situation of whole process easier to control. Practice proves that the system is reliable operation and meets the demand of precision, and can completely replace the imported products.
Improving diffusion furnace capability using model-based temperature control in a production environment
This paper describes the design, development, and implementation of model-based temperature control (MBTC) to improve diffusion furnace capability in a production environment. An integrated manufacturable approach for modeling and robust H/sub /spl infin// multivariable controller design is developed to replace standard proportional integral derivative (PID) furnace control. The design was originally evaluated on an oxidation furnace and is presently being propagated throughout the entire diffusion area. Production results demonstrate excellent temperature control, tighter process results, and increased utilization. Manually induced disturbances during ironman testing, as well as normal production disturbances, have shown the system requires no adjustment or reconfiguration for improved control of oxidation growth and LPCVD film deposition.