Design Of Polishing Force Loading System Of Silicon Wafer Polishing Machine

Be compared with other transmission and control technologies, pneumatic technology has the characteristics about simple structure, working reliably, easy to master, convenient maintenance, clean, strong adaptability to special working environment, etc. In the processing environment fields that need higher requirements, pneumatic technology is used in grinding and polishing the surface of workpieces, makes the surface roughness of workpieces meet requirement.With the development of social productivity, people’s living standard becomes higher and higher. This causes that more and more intelligent home appliances and digital products appear, these use a lot of digital chip, the main raw material of digital chip is silicon wafer. Meanwhile, with the continuous upgrading of digital products, their performances become better and better. These require integration level of digital chip grow higher and higher; Then, these make requirements of surface roughness and flatness of silicon wafers become higher and higher, and in particular surface roughness.Silicon wafer polishing machine is main equipment for processing surface of silicon wafers. Due to higher and higher requirements of surface quality of silicon wafer, many countries study it; But mostly they concentrate on mechanical structure, materials of polishing equipment, application of computer aided software, chemical polishing technology, trajectory of polishing disk, software control system of polishing machine, etc. In recent years, more and more polishing machine manufacturing enterprises hope that polishing force loading systems of silicon wafer polishing machines can be changed from mainstream ball screw nut to pneumatic loading to avoid polluting environment. But, study of pneumatic loading system is still less. The performance of pneumatic loading system directly determines the quality of processing. In this paper, the performance of pneumatic loading system is research objective, hopes to make the performance of pneumatic loading system higher and the quality of processing better.In this paper, according to the given requirements from a polishing machine manufacturing enterprise, designed the pneumatic loading system of a silicon wafer polishing machine for this enterprise; Simulated and analyzed the pneumatic loading system by computer, to make the performance of the pneumatic loading system meet the requirements; This paper made further research on electric-pneumatic proportional valve and cylinder. Through analyzing the pressure-flow characteristics of electric-pneumatic proportional valve, to get valve coefficient of electrical proportional valve, then, it could lay the foundation for modeling the system. The crawling phenomenon that be caused by the friction of cylinder is the most important factor that affects the performance of pneumatic loading system. This paper analyzed crawling phenomenon that be caused by the friction of cylinder, got the critical velocity of cylinder when cylinder was crawling, chose appropriate friction compensation method and compensate the friction of cylinder, to reduce the adverse effects of the friction of cylinder on the whole system.Through adding chatter signal to control signal of pneumatic loading system to compensate the friction of cylinder, and respectively combined with PID control and fuzzy PID control, it could be known that superiority of intelligent control by simulating the system.Essentially, pneumatic loading system is pneumatic force control system. It belongs to relatively new research field, the research on it has a certain theoretical significance and practical engineering value.