单晶硅电火花铣削维持电压测定及蚀除机理研究

Sustaining Voltage Measurement and Erosion Mechanism of Single-crystal Silicon by Electrical Discharge Milling

提出一种以电火花放电加工技术对半导体硅材料进行铣削加工的方法,建立了半导体放电加工电路模型,测量了半导体放电加工放电通道的维持电压,其值为18 V。在此基础上,从放电能量和ANSYS仿真两个方面对单晶硅电火花铣削的蚀除机理进行了研究。通过单位能量蚀除量的计算,并与45钢比较,得出单位能量单晶硅的蚀除量是45钢的4倍,由此提出了单晶硅蚀除是热蚀除和热应力剥落综合作用的结果;通过仿真分别计算出单脉冲放电温度场和热应力场的蚀除量,其热应力剥落是热蚀除的4.6倍,与基于能量计算的分析结果基本吻合。最后实验验证了分析结果的正确性。

A method of milling semiconductor silicon material through electrical discharge machining was put forward and its circuit model was established,then the sustaining voltage of discharge channel was measured and the value was 18V.On this basis,the erosion mechanism of single-crystal silicon was studied from aspects of discharge energy and ANSYS simulation.The unit energy erosion volume of single-crystal silicon is 4 times as large as that of 45 steel by the calculation,from which an idea was proposed that the erosion process of single-crystal silicon is the result of a combined action of melting erosion and thermal stress spalling.The volume of melting erosion and thermal stress spalling of the silicon was calculated from simulation,the volume of thermal stress spalling is 4.6 times as large as that of melting erosion,this result is basically consistent with energy analysis result.The analytical result is proved to be right by the test at last.