The Research On The Mechanism And Control Method Of Multi-wire Sawing

Multi-wire slicing is a novel method in the field of wafer slicing;recently multi-wire saw has gradually replaced the method of ID saw,and become the prevailing equipment in this domain.Some key techniques as concerning sawing mechanism,control of the constant tension wire moving system,process control of the sawing machine,etc.are researched in this paper.It provides the theoretical basis and practical guidance for the research and development of multi-wire saw machine.After studying all the references we can find,the paper has an extensive and in-depth research on the mechanism of the multi-wire sawing.It points out that the ideal,single "Roll- Indent" sawing model cannot explain the whole process well.The theory research not only considers the multiple status of the flowing abrasive in the process,but also bases on the theory of Material mechanics,hydrodynamics,tribology and Indentation fracture.Combined with the result of experiment data and wafer,the paper proposes a new model---"Roll- Indent" and "Roll-Indent-chipping" multi-model hybrid processing model.In this model,the abrasive in the status of semi-contact and full-contact use the "Roll- Indent" and "Roll- Indent - chipping" independently to actualize the sawing process.It not only explains the whole process better,but also more close to the actual situation.The integrated mechanics behavior(machining mechanism of the abrasive ) of the abrasive depends on the hydrodynamic condition of the slurry film.Using flow field and pressure field of the slurry as the study object,the research of the movement analysis of the slurry film provides the theoretical basis of the -"Roll-Chisel" and "Roll-Chisel-cutting" multi-model hybrid processing modelSince the driven force of the abrasive is from sawing wire,the movement status of the sawing wire has become the core issues of the multi-wire sawing machine.The paper conducts in-depth study on the main aspects related to the sawing wire such as the wire loss and the wire vibration.It provides the theoretical guidance of the design and application of the machine.In the considering of the reality of the machine development,the paper proposes a method to realize the system tension control.It is suitable for the characteristics of the multi-wire sawing process.It uses the tension control motor and achieves the control through the moving wire speed difference.Not only the mathematical models of the system are established,the control strategy of the motors using in the system are also designed.The simulation result and the operation result confirm the feasibility.Since the causality between the efficiency of the multi-wire sawing and the process parameters are difficult to be expressed by a mathematical analysis,the papers proposes to use neural network model to establish the process model of the multi-wire sawing.The practical process data show that the object has a better convergence character.The study of the paper directly guides the design and development of the "NWS6X2 Multi-wire sawing machine".It not only fills in the gaps of the research field,but also has an important theoretical and practical value in the self-ownership of the core technology of the silicon production.