Research Of Surface Formation Mechanism Of Microgroove In Silicon Wafer Under The Diamond Fly-cutting

It is considered that single crystal silicon are the important substrate materials of integrated circuits and TR optical materials because of its choiceness properties, such as good optical function, high mechanical strength and steady chemical property. However,single crystal silicon is a kind of difficult-to-cut material because of its hardness and brittleness. The ripened machining method of single crystal silicon is electrochemical corrosion so far, but such methods exists many difficult problems to solve, especially inefficiency and serious pollution. With the development of machine tool and cutter technology, the precision machining of this kind of material has become a research hotspot. Diamond fly cutting machining technology have a huge advantage in the processing of complex microstructure composed with linear groove, and can get microstructure surface quality with nanoscale roughness and micrometer-scale surface accuracy on the ordinary materials directly. As a kind of machining method with flexible and high speed, diamond fly-cutting processing technology has being caused the attention of many researchers both at home and abroad.In this paper, diamond fly cutting machining technology has been applied to single crystal silicon micro linear slot processing, according to its principle and characteristics.To study the formation mechanism of the microgroove in single crystal silicon under the diamond fly-cutting, the research was explored from the several aspects, which include the material removal mechanism, the cutting force, brittle-ductile transition, the precision of surface roughness and microgroove shape. The main contents are as following:1. Trajectory of cutter was analyzed in the process of machining, and the experimental platform of diamond fly-cutting has been set up, which is suitable for the micro-groove processing of single crystal silicon. Then the critical component,fly-cutter disk, was optimally designed, and the stress-strain response was obtained under high speed of the fly-cutter disk through the simulation analysis.2. The material removal of single crystal silicon was theoretically analyzed, the model of undeformed chip thickness was also established, then the experiment of brittle-ductile transition of silicon was finished on the experimental platform. And the influence of single crystal silicon removal mechanism caused by the cutting velocity,cutting depth, feed and processing method, was analyzed.3. The mathematical prediction model of the cutting force was established, which befits both the traits of diamond fly-cutting technology and the material properties of single crystal silicon. Then cutting forces were measured through the cutting experiment of the silicon wafer under the diamond fly-cutting. The influence of machining parameters on the cutting force was summarized through experimental results, and the correctness of the model was verified by cutting force experiment.4. The orthogonal experiment of surface roughness of microgroove in silicon was done based on the theoretical analysis of surface roughness and profile error. The influence rules of machining parameters on the surface roughness and shape precision were analyzed and discussed according to the experimental results finally. According to the data of micro-groove surface roughness from the diamond fly-cutting experiments,the nonlinear relationship curve between the largest undeformed chip thickness and microgroove surface roughness Ra were obtained using Gaussian-fitting principle, and the prediction model of the surface roughness was also got finally.