Study On Fabrication Of Diamond Grinding Wheel And Its Preparation For Ultra-Precision Grinding Of Silicon

Grinding is an important process for manufacturing of silicon wafers. The demand for silicon wafers with better quality and lower price presents tremendous challenges for the grinding wheels used in the silicon wafer industry. The stringent requirements for these grinding wheels in clued low damage on ground surfaces, self-dressing ability, consistent performance, long wheel lives, and low prices. This paper focuses on the effects of ultra-precision grinding wheels' preparation and formulation on the wheel porosity, strength and hardness. This analyzes the impacts of preparation and formulation on grinding ratio, grinding efficiency and surface quality of silicon. Through theoretical calculation and experiment, this study focuses on the effects of sodium bicarbonate particle size on the wheel porosity size and performance, and the effects of sodium bicarbonate content on the wheel porosity and performance. The conclusions are obtained as follows:(1) As Resin bond content increases, the wheel porosity has a trend of reducing, the wheel strength, hardness, grinding ratio,and grinding efficiency promote,and silicon surface roughness hardly changes (Ra=0.9μm)firstly and increases lastly.(2) As diamond content ries from 20% to 60%, the wheel porosity and strength hardly change, the wheel hardness has a trend of slow growth.,the wheel grinding ratio and grinding efficiency upgrades firstly and then remained stable, silicon surface roughness has a trend of slow reduction.fisrtly and then remaines stable.(3)During the hardening process of wheel, pore of sodium bicarbonate decomposed of carbon dioxide gas and formed Wheel stoma within the wheel.Through theoretical calculation and experimental verification, it has some results:sodium bicarbonate particle size determined the wheel stoma size and sodium bicarbonate content determined wheel porosity.(4) It comes to same results that sodium bicarbonate particle size and sodium bicarbonate content affect the performance of wheel for Ultra-Precision grinding of silicon. As sodium bicarbonate particle size becomesfrom 5μm to 100μm, the wheel strength and hardness lower a little, the wheel porosity keep a certain number, the wheel grinding ratio and grinding efficiency reduce, silicon surface roughness increase. With sodium bicarbonate content increasing, the wheel porosity rises, the wheel hardness and strength decrease,the wheel grinding ratio and grinding efficiency reduce,silicon surface roughness has a trend of reducing with sodium bicarbonate content rising from 0% to 30%.(5)As the molding pressure increases, the wheel porosity gradually decreases, the wheel strength and hardness increase, the wheel grinding ratio is big when molding pressure is strong, wheel grinding efficiency grows with molding pressure increasing and then decreases when molding pressure is over a number,and silicon surface roughness keep a number and then increases.(6)With a certain range, the wheel porosity, strength and hardness increase with hardening temperature increasing. The wheel grinding ratio upgrades with hardening temperature from 220℃to 280℃and reduces a little until 300℃. With the hardening temperature increasing from 220℃to 260℃,the wheel grinding efficiency promotes and silicon surface roughness hardly changes. With the hardening temperature increasing from 260℃to 300℃, the wheel grinding efficiency lowers and silicon surface roughness increases.