Systematic Study On Equal Diameter Control Of Crystal Growth In Czochralski Process

Crystal can realize the mutual conversion of special energy,such as converting electric energy into magnetic energy,light energy,sound energy,etc.through crystal,crystal h as a very important position in the development of modern science.With the development and large-scale application of electronic products such as mobile phones and computers,a large number of all kinds of crystal materials are needed.The development of crystal materials also promotes the development of modern science and technology.Due to the defects of natural crystals,the quality and quantity can not fully meet the needs of the development of modern science and technology,so that the development of artificial crystals has been very good.In this paper,we first compare the various process methods of laser crystal growth,using the crystal weight change as the feedback system and the temperature control system of the crucible to control the equal diameter growth of the crystal,using the up weighing method to meet the weight feedback system,taking the crystal weight as the feedback signal of the diameter.Then we design the weighing mechanism of the up weighing method of the crystal,use the temperature control system as the output to control the equal diameter growth of the crystal,and take this as the thinking to carry out the overall design of the laser crystal equipment;and calculate and check the natural frequency of the rotating seeded crystal rod,calculate the influence of the working seeded crystal rod on the crystal crystal and the weighing sensor,and the influence of the vibration symmetrical weight sensor of the body Ring.In terms of software design,because the control accuracy plays a key role in the temperature control system of crystal growth,but the crystal growth furnace has a system with large delay,large inertia,non-linearity and object change.These factors have not changed much but are uncertain,so it is necessary to consider multiple factors from the software,and the best and most economic way is to better design the control software The fuzzy PID control adopted in this paper can satisfy the equal diameter growth of laser crystal.In the aspect of hardware design,this paper calculates and selects the mechanical and electrical components of the crystal furnace according to the design requirements of the lifting device of the crystal furnace;after the selection,the ports of the electrical components are allocated and set according to the needs,and the electrical circuit diagram is drawn;finally,according to the designed software design flow chart,the software design of the temperature controller of the Yonghong PLC controller is carried out.