MPCVD多晶金刚石片的研磨均匀性分析

在游离磨料研磨过程中，研磨的驱动方式及工艺参数等直接影响加工后工件的平面度和表面粗糙度。为了探究基于旋摆式驱动的游离磨料研磨工艺参数对MPCVD多晶金刚石片平整化的影响，建立旋摆式驱动平面研磨过程中的单磨粒运动学模型，根据实际研磨过程采用多磨粒随机分布模型进行计算机仿真计算，引入多磨粒轨迹的均匀性离散系数对磨粒轨迹均匀性进行分析。结果表明:当转速比取值等于0.5时，磨粒轨迹离散系数最大；当转速比小于等于0.5时，离散系数与转速比为正相关；研磨盘摆动弧线的弦长大于金刚石片直径时，磨粒相对于整个金刚石片表面的运动轨迹分布较为均匀；计算机仿真计算得到了研磨最优参数，并通过2英寸MPCVD多晶金刚石片研磨试验验证了仿真结果的有效性。研磨后金刚石片表面PV值为2.4 μm，表面粗糙度R_a达到139 nm，材料去除率d_MRR为10.1 μm/h。 

Analysis on the lapping uniformity of MPCVD polycrystalline diamond wafer

In the process of free abrasive lapping, the driving mode and process parameters directly affect the flatness and surface roughness of the workpiece. To explore the effect of free abrasive lapping process parameters based on rotary swing drive on the planarization of MPCVD polycrystalline diamond film, a kinematic model of single abrasive grain in rotary swing drive plane lapping process was established in this study. According to the actual lapping process, this paper adopts the multi-abrasive random distribution model for computer simulation and introduces the uniformity dispersion coefficient of multi-abrasive trajectory to analyze the diamond surface abrasive trajectory. The results suggest that when the speed ratio equals 0.5, the dispersion coefficient of abrasive trajectory is the largest; when the speed ratio is less than or equals 0.5, the dispersion coefficient of abrasive trajectory is positively correlated with the speed ratio; and when the length of the swing arc chord of the lapping workpiece disc is larger than the diameter of the diamond film, the motion trajectory of the abrasive particles relative to the whole diamond film surface is evenly distributed. The optimal lapping parameters are obtained by computer simulation. Through the 2 inch polycrystalline diamond lapping test, the final surface PV value of diamond is 2.4 μm, the surface roughness Ra is 139 nm and the material removal rate d_MRR is 10.1 μm/h.