Study On Preparation And Properties Of Ultra-thin Diamond Blade

Ultra thin diamond cutting wafer is the most commonly used tool in cutting silicon wafer.Its stability,uniformity and cutting performance determine the accuracy and quality of silicon wafer.However,the average life and performance of the tools produced in China are far less than those produced abroad.Therefore,It is necessary to research and develop ultra-thin diamond tools with high cutting accuracy,long service life,good stability and uniformity.In this paper,nickel diamond ultra-thin cutting tools were prepared by using self-developed electroplating bath which can realize self rotation of cathode in electroplating process and diamond particles as reinforcement phase.The micro morphology,hardness,diamond particle content,tool thickness uniformity,tool wear resistance and cutting performance of the tool under different cathode motion states were studied.The main research contents are as follows:The optimum preparation parameters of Ni diamond cutting tools were obtained by orthogonal experiment as follows:diamond concentration 25g/L,current density 1.8A/dm2,stirring speed 250rpm,bath temperature 45?,electroplating time 50min,pH4.0.Parallel experiments were designed under these conditions,the average tool thickness is 30.39 ?m.The hardness is 2893.5Hv and the diamond content is 80.18%.The thickness,hardness and diamond particle content of each tool are consistent,which indicates that the best technological conditions are repeatable,and the performance of the tool is stable and the quality is excellent.Single factor experiments were designed to study the effects of cathode current density,stirring speed,bath temperature and electroplating time on tool hardness,diamond particle content,tool thickness uniformity and tool wear resistance.The results show that the current density and stirring speed have the most significant effect on the tool performance.The study of wear resistance shows that the content of diamond particles in the coating is the main factor affecting the friction performance of the coating.Scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD)were used to analyze the surface morphology,fault morphology,diamond particle distribution and phase structure of the tool.The results show that the coating is composed of nickel and diamond particles,and the diamond particles are evenly distributed in the whole coating.The cross-section morphology shows that the diamond particles are not only distributed on the surface of the coating.The results of XRD show that the preferred orientation of nickel crystal plane in the coating is Ni(111).The addition of diamond increases the grain size of the coating by 3%,but does not change the preferred orientation of nickel crystal plane in the coating.A set of electroplating experiment equipment was designed and developed.The effects of self-rotating state of cathode on tool hardness,wear resistance,diamond content and distribution uniformity were studied.Compared with the static cathode,the self-rotation of the cathode greatly improves the performance of the tool.The motion mode of the cathode is the key factor affecting the uniform distribution of diamond particles in the coating,uniform thickness of the tool,diamond content,cutting performance of the tool and other comprehensive performance of the tool.In addition,the friction coefficient of the tool under different motion states of the cathode was studied,and the wear mechanism of nickel-diamond tool was explored.Using DISCO-DAD3350 automatic dicing machine,the cutting performance of the cutting tool prepared by cathode self rotation was studied with the slit width,the size of edge collapse and the slit ratio as the criteria.Compared with the static cathode,the slit ratio and the size of edge collapse of the cutting tool prepared by cathode self rotation were smaller.The average slitting ratio and chipping size are 1.64 and 4.83 ?m.The effects of surfactants,brighteners and diamond particles on the electrodeposition process of nickel ion were studied by cathodic polarization curve.The results show that the addition of surfactants,brighteners and diamond particles can make the deposition potential of nickel ion shift negatively and the cathodic polarization increase,moreover,the slope of polarization curve decreases,which is beneficial to the grain refinement of the coating and improves the brightness of the coating;accelerate the electrodeposition reaction.