基于模型的晶体生长控制技术的研究

上称重提拉法晶体生长模型由上缩颈、放肩、等颈、收肩、下缩颈和收尾拉脱等组成，每种晶体分别配有不同的生长模型，由监控站根据工艺要求指定执行对应的生长程式。为确保生长程式的集中发布和准确执行，系统采用基于Modbus-TCP的可编程控制器，将生长工艺发送至生产设备。晶体重量与温度回路采用串级控制，数据表明晶体生长稳定，等颈误差小于±0．2mm。

Study on the Model Based Control System for Crystal Growing

The technological process of crystal growing with CZ method is composed of upperneck, enlarging shoulder, equal diameter, reducing shoulder, down neck and tail. Each kind of crystal has different growing control model. According to technological requirement, the monitor computer chooses different formula for every crystal. To ensure the centralized issuance and the properly execution of the growing formula, the control system makes use of programmable controller based on Modbus-TCP to configure control network, and send the control network to the field device. Cascade control is used in the control loop of crystal weight and temperature. The data show that crystal growing is steady, the equal diameter error is less than ±0.2 mm.