Design Of Electric Control System Of CZ Automatic Single Crystal Furnace

Direct pulling single crystal furnace is an important equipment for the production of single crystal silicon,the application of single crystal silicon in microelectronic and optoelectronic industry is very wide.The rapid development of the electronics industry in recent years,requirements of silicon wafer has the characteristics of large diameter,high integrity,high purity,good uniformity,which requires a straight pull toward the crystal furnace feeding amount,high reliability,high quality,simple operation,friendly interface,the development direction of automatic control.The import of Czochralski single crystal furnace is expensive,suitable for very large scale integrated circuit used in the production of silicon The photovoltaic industry,silicon purity requirements are relatively low,the domestic single crystal furnace,can greatly reduce manufacturing cost,improve the competitiveness of domestic products,has important practical significance to promote the development of photovoltaic industry in china.This paper takes the full upgrade and transformation of the Seven Star electronic direct pulling single crystal furnace as an opportunity to design the electronic control system of the fully automatic direct pulling single crystal furnace.The main work involves two aspects of hardware and software.First,build and optimize the electrical control hardware platform.The growth of seeding including neck growth,crown,shoulder,body growth,tail,and stop,how to detect and control the main technical parameters,is the key to improve the degree of automation,single crystal furnace to realize high precision and high purity,high reliability.From the crystal growth process,based on the analysis of the Czochralski single-crystal furnace mechanical structure of the system,put forward "PLC,touch screen,computer integrated control system model,and completed the hardware selection and matching.Second,the software of electrical control system is developed.The electrical control system software design,is driven by software on the hardware to control the crystal growth,ensure the production process of single crystal furnace smooth,crystal growth environment is stable,stable,the whole process of single crystal and crystal defects reduce the temperature curve of bar diameter accurate control.The software includes two aspects: functional design and program development,including three aspects of PLC centralized control design,man-machine interface design,CCD software design,etc..The mechanical structure of the system and electrical control system design,delivery of customers,to achieve a fully automated production process of single crystal furnace,reflecting the high reliability,high quality and good operation performance.