Researches And Application Of Control Mechanism On Cutting System Of CNC Multi-wire Saw

Multi-wire slicing is the innovational core process and main technology in the manufacturing process of the electronic device substrates which are adopted in solar photovoltaic, large-scale integrated circuit, it can significantly increase the rate of chip production, chip quality and production efficiency. Multi-wire saw(MWS) is the key equipment in manufacturing industry chain of electronic device, which is widely used to slice monocrystalline silicon, polycrystalline silicon, sapphire, synthetic crystal, optical glass, magnetic materials, piezoelectric ceramics and other expensive crisp and hard materials. The control system of MWS is intricate and the manufacturing technologies are very difficult, the key technologies have been monopolized by few companies located in Japan, Switzerland etc, this situation seriously constrained the development of the electronic industry chain of our country. So researches on the key technologies and development of MWS, winning the proprietary intellectual property rights are very important, which can break through the technology monopolization of foreign country and the bottlenecks of industry chain. This dissertation is aiming at these problems, the control mechanisms and the technical implementation of MWS for magnetic materials are deeply and systematically studied.(1) The significance and the background of multi wire slicing technology are discussed. The research status at home and abroad, developing trend of multi wire slicing technology and equipments are summarized. The theoretical and technical bases of multi wire slicing system are explained, the primary research contents are given, and the important and difficult points of the topic are pointed out.(2) Based on the researches and simulation of tension control, multi-motor synchronization and working table structure of three-axis multi-wire slicing system, the topic made a quantitative analysis of tension fluctuation and synchronization error when the MWS system is working, which is time variant. The results show that tension control and multi-motor synchronous control determines the accuracy, of MWS.(3) Based on the description of the tension control mechanism of MWS cutting control system, the mathematical model of the tension control system was established, which using AC servo as actuators, and three tension control schemes were proposed, which are PID, simplex optimization and fuzzy control tension control system scheme, the feasibilities and control effects are compared by analyzing the results of simulation. The topic focused on the design and implementation of tension control scheme based on fuzzy control. Simulation and experimental results show that this method has good control accuracy and robustness, the tension of the cutting wire is controlled in±1N.(4) Aiming at the speed synchronization problems of MWS cutting system, a shaftness speed synchronous system mathematical model was established, which use servo motor as the actuator. Three speed synchronization control methods are proposed. Through simulation comparison, it show that the model reference adaptive PID control method, which based on nearest neighbor clustering algorithm, had better dynamic and static characteristics and anti-jamming capacity. The control method is applied to the design and implementation of CNC multi wire saw XQ300B, and ensured the synchronization speed up to600m/min.(5) Aiming at the cutting process control problems of the MWS cutting system, force analysis about cutting wire and cutting materials are analyzed. Based on the mathematical relationship between bending force on cutting wire and the removal rate of cutting materials, a simulation method focus on the distribution shape of cutting materials was proposed. Through comparison of adjustments on tension and speed of cutting wire, the simulation results show that both tension and speed of cutting wire have significant effects on the efficiency and chip quality of multi wire slicing system.(6) A MWS machine for magnetic materials cutting named as XQ300B was designed and developed, as a test prototype, the result of running situation and cutting quality were measured, test results show that the MWS run stably, an effective tension control and high precision synchronous control were achieved, and the yield of chip meet the design requirements.The key technologies of tension control, synchronous control and cutting process control in MWS which were tackled in this dissertation, which can solve the problems in product developments and industrialization of MWS for magnetic materials, and have important theoretical and technical demonstration effect on MWS design and manufacture.