摘要
多丝切割是一种新型的硅片切片加工方法，近年来多丝切割己经逐渐取代内圆切割成为硅片切片加工的主流。本文针对多丝切割的切割加工机理、恒张力的走丝系统控制、切割机使用中的工艺控制等关键技术进行了深入地研究，为多丝切割机的研发和使用提供了理论依据和实际指导。
在广泛参考研究国外同类文献的基础上，论文对多丝切割的机理进行了深入地研究，认为理想、单一的“滚一刻”切割加工模型对整个切割过程难以解释周全。基于多丝切割中磨粒运行存在多种状态，以材料力学、流体力学、摩擦学和压痕断裂理论等为基础，结合试验数据和切割结果的分析，提出了“滚一刻”、“滚一刻一削”多模型混合加工模型。认为:处于半接触和全接触状态下的磨粒，各自以“滚一刻”、“滚一刻一削”方式实施切割加工，从而较好地解释了多丝切割加工的整个过程，更加贴近实际运行状况;
由于研磨粒的综合力学行为(研磨粒的加工机理)取决于研磨液膜的流体力学条件，论文以研磨液的流场、压力场为研究对象，通过加工区域研磨液的运动分析，为论文提出的“滚一刻”，“滚一刻一削”混合模型的切割加工机理提供了理论依据;
由于磨粒的驱动源于切割丝，切割丝的运动状态成为多丝切割机的核心问题。论文在与切割丝相关联的主要方面(丝损、丝震)进行了深入地研究，为机床的设计与应用提供了理论指导。结合机床研制的实际，论文提出了一种适合多丝切割工艺特点的、采用张力控制电机并通过走丝系统速度差实现系统张力控制的新方法，建立了系统的数学模型，设计了系统中各电机的控制策略。仿真结果与实际运行验证、证实了该方法的可行性。
由于多丝切割的效率与各工艺参数之间的因果关系很难采用一个数学解析式给予表达。论文应用神经网络理论，提出并建立了多丝切割加工工艺模型。实际工艺数据表明目标具有较好的收敛特性，可以用来指导加工工艺参数的确定。
本论文的研究工作直接结合《NWS6X2型钢丝多丝切割机》的设计和研制，填补了我国在本领域研究工作的空白，在自主掌握硅片生产的核心技术方面有着重要理论意义和实际应用价值。
关键词:磨粒，多丝切割，“滚一刻一削”，张力，模糊控制，神经网络模型
ABSTRACT
Mufti-wire slicing is a novel method in the field of wafer slicing; recentlymufti-wire saw has gradually replaced the method of ID saw, and become theprevailing equipment in this domain. Some key techniques as concerning sawingmechanism, control of the constant tension wire moving system, process control ofthe sawing machine, etc. are researched in this paper.It provides the theoretical basis
and practical guidance for the research and development of mufti-wire saw machine.
After stud如ng all the references we can find, the paper has an extensive andin-depth research on the mechanism of the mufti-wire sawing. It points out that theideal, single "Roll- Indent" sawing model cannot explain the whole process well. Thetheory research not only considers the multiple status of the flowing abrasive in theprocess, but also bases on the theory of Material mechanics, hydrodynamics, tribologyand Indentation fracture.Combined with the result of experiment data and wafer, thepaper proposes a new model---"Roll- Indent" and "Roll-Indent-chipping" mufti-modelhybrid processing model. In this model, the abrasive in the status of semi-contact andfull-contact use the "Roll- Indent" and "Roll- Indent一chipping" independently toactualize the sawing process. It not only explains the whole process better, but alsomore close to the actual situation.
The integrated mechanics behavior (machining mechanism of the abrasive)ofthe abrasive depends on the hydrodynamic condition of the slurry film. Using flowfield and pressure field of the slurry as the study object, the research of the movementanalysis of the slurry film provides the theoretical basis of the一“Roll-Chisel" and"Roll-Chisel-cutting" mufti-model hybrid processing model
Since the driven force of the abrasive is from sawing wire, the movement statusof the sawing wire has become the core issues of the mufti-wire sawing machine. Thepaper conducts in-depth study on the main aspects related to the sawing wire such asthe wire loss and the wire vibration. It provides the theoretical guidance of the designand application of the machine. In the considering of the reality of the machinedevelopment, the paper proposes a method to realize the system tension control. It issuitable for the characteristics of the mufti-wire sawing process. It uses the tensioncontrol motor and achieves the control through the moving wire speed difference. Notonly the mathematical models of the system are established, the control strategy of themotors using in the system are also designed. Thesimulation result and the operationresult confirm the feasibility.
