研磨压力对固结聚集体磨料垫自修正影响

固结磨料研磨过程中磨料的微破碎是实现固结磨料垫自修正特性的主要途径,研磨压力是影响磨粒微破碎的关键参数。选用单晶金刚石和聚集体金刚石作为磨粒制备固结磨料垫,在15 kPa压力下以石英玻璃为加工对象进行研磨实验,比较两者的材料去除率及加工稳定性;制备了4种陶瓷结合剂含量的聚集体金刚石,并制备成固结聚集体金刚石磨料垫,探索了不同压力下的固结聚集体金刚石磨料垫的自修正性能;分析了研磨后的工件表面粗糙度和表面微观形貌。结果表明:采用固结聚集体金刚石磨料垫,研磨后工件表面粗糙度低,去除效率稳定;在15~21 kPa的压力下,结合剂含量次高的聚集体金刚石研磨效率高,材料去除率达到8.94~12.43μm/min,加工性能较稳定,研磨后的工件表面粗糙度R a在60 nm左右;在3.5~7 kPa压力下,结合剂含量次低的聚集体金刚石研磨性能较稳定,材料去除率在2.67~3.12μm/min,研磨后的表面粗糙度R a在40 nm左右。高结合剂含量的聚集体金刚石磨粒更适合高研磨压力条件,而低结合剂的聚集体金刚石磨粒更适合于低研磨压力。     

Effects of compound diamond slurry with graphene for lapping of sapphire wafers

Recently, sapphire has been used in a wide range of applications including optics, consumer electronics, and especially the rapidly growing LED wafer manuf     

Optimal cutting time and speed in abrasive lapping of ceramic

The cutting time and speed in the abrasive lapping of zirconia ceramics are investigated. Their influence on the productivity and final surface roughness is considered. The optimal cutting time and speed are determined     

基于UG的蓝宝石衬底基片双面研磨轨迹研究

通过数学理论建模与UG建模,建立了蓝宝石衬底基片双面研磨的运动模型并获得了在三种传动比情况下行星齿轮上不同点的轨迹。通过分析研磨轨迹和研磨速度可知在传动比为1时行星齿轮各点的轨迹为均匀分布的圆形且速度相等,所有点的运动周期相等而且比其它情况下的周期短,有利于提高研磨效率和形状精度,结果成功地解决了由于行星齿轮内的衬底基片各点处速度不一样而导致的平面度差的问题和行星齿轮中心不能放置蓝宝石衬底基片的问题。     

蓝宝石衬底基片工艺质量检测指标及方法的研究进展

根据蓝宝石衬底基片国家标准和国际质量保证体系标准,结合目前蓝宝石衬底基片生产和科研的实际情况,阐述了目前蓝宝石衬底基片生长、掏棒切片、研磨抛光和清洗加工过程中的质量检测指标、检测方法,以及检测设备.指出了蓝宝石衬底基片检测技术的研究对衬底基片生产的重要性.总结了蓝宝石衬底基片检测技术的现状,半导体材料GaN衬底用蓝宝石单晶的纯度要达到99.999％以上,位错密度在102/cm2范围内,晶片切片厚度偏差不超过20μm,表面粗糙度要达到Ra0.3nm水平.指出了现有检测技术的不足和今后的发展趋势,对蓝宝石衬底检测技术的进一步发展具有引导性的作用.     

六面体蓝宝石磨料冲击加工声学系统研制

针对蓝宝石等硬脆材料难加工的特点,研究了蓝宝石磨料冲击加工方法与加工原理,并进行了磨料冲击加工仿真模拟;从理论上分析、设计了磨料冲击加工声学系统,给出了参数设计和计算过程,得出了声学部件的基本尺寸和参数,并用有限元软件ANSYS对声学系统进行了模态分析。根据理论计算参数和分析结果,制造了20 kHz换能器、阶梯型变幅杆和工具头。采用HP4294A阻抗分析仪测量了声学系统的谐振频率,利用装配好的声学系统进行了试样加工。测量结果表明,与理想谐振频率相差0.019 452 kHz,符合设计、使用要求;研究结果表明,所研制的声学系统能够提高加工精度,改善产品表面质量。     

Abrasive removal depth for polishing a sapphire wafer by a cross-patterned polishing pad with different abrasive particle sizes

The paper establishes a new theoretical model for abrasive removal depth for polishing a sapphire wafer using chemical mechanical polishing with a polishing pad that has a cross pattern. The theoretical model uses binary image pixel division to calculate the pixel polishing times. An abrasive contact model for single-pixel multiple abrasive particles, to estimate the contact force between a single abrasive particle and the wafer, is then established. When the contact force is calculated, it is possible to calculate the abrasive depth of a single abrasive particle on the surface of the sapphire wafer. Using this theoretical model, carring a numerical simulation with a slurry of the same concentration, but with different abrasive particle diameters, determines the removal volume and average abrasive removal depth at each pixel position and the surface condition of the wafer. The simulation result is also compared with experimental data, in order to verify that the new model is feasible.     

固着磨料加工碳化硅反射镜的实验

考虑固着磨料加工工艺其固着磨料与工件相对运动关系固定,有利于精确加工,提出了采用该工艺加工碳化硅反射镜的方法,利用大颗粒金刚石磨料快速加工出了较好的镜面质量.在工艺实验中,分别测得了W7,W5,W3.5,W1.5 固着磨料丸片在特定转速和压力下对碳化硅材料的去除特性.对多组去除量曲线的分析表明,此工艺不仅有着较高的去除率,而且稳定性良好.对表面粗糙度测量的结果表明,使用W7丸片即可获得粗糙度为42.758 am rms的镜面.减小所用丸片的粒度,工件表面粗糙度随之减小,使用WI.5丸片抛光后,最终获得了粗糙度为1.591 nm rms的光滑镜面.实验结果表明,固着磨料加工碳化硅反射镜工艺在粗研、精研、粗抛等加工阶段内可以取代传统的散粒磨料加工工艺.     

散料研磨工艺对工件表面质量及材料去除率的影响

通过实验探讨了散料研磨过程中磨料种类、磨料粒度和研磨剂装入量等工艺参数对工件表面质量和材料去除率的影响.实验结果表明,随磨料粒度的增大,工件表面粗糙度值、残余应力和材料去除率增大;采用相同粒度磨料研磨,磨料的硬度越高,工件表面残余应力和材料去除率越大.硬度高、脆性大的磨料,可有效减小研磨表面粗糙度值;随研磨剂装入量的增大,表面残余应力减小.对工件表面粗糙度和材料去除率而言,研磨剂装入量有一最佳值,装入量过小或过大,均会降低工件表面质量和研磨效率.     

固结磨粒金刚石线锯技术的研究

金刚石线锯是一种对硬脆性材料进行精密、窄缝切割技术。其中,固结磨粒金刚石线锯以其切割速度快、耗材成本低及环保等优点被广泛应用于半导体和太阳能电池硅材料的切割加工中。利用目前国内现有的设备和国际上较好的金刚石线锯丝,从切割工艺参数、失效机理等方面对硅材料的固结磨粒金刚石线锯进行了试验和分析,对提高硅材料切割效率与切割质量有一定的指导意义。     

Development of a new lapping method for high precision ball screw (1 report)-feasibility study of a prototyped lapping tool for automatic lapping process

Ball screws are being lapped as a finishing process to improve the travel variation, drunkenness and surface finish in order to provide high precision requirements in various mechanical applications. However, the existing manufacturing method is very labor intensive that needs a highly skilled machinist to perform the hand lapping operations using the conventional laps which have two or three slits. These types of lap cannot eliminate and improve the special components of drunkenness such as ellipsoidal, triangular and other polygonal cross sections. This paper presents a new lapping method to determine the technical and operational feasibility of a prototyped lapping tool with the combination of a flexible lap and polyurethane elastomer which can be mounted in the vertical-type automatic lapping machine. This new type lapping tool with six slits, is especially designed which each section can move in radial direction wherein the uniform lapping pressure is applied on the test piece from six directions. Based on experimental results, it showed that the travel variation was greatly reduced along with drunkenness and lapping time.     

Distribution of diamond grains in fixed abrasive wire sawing process

For over 20 years, wire sawing has been the primary method used for slicing ingots of silicon, sapphire, and silicon carbide into wafer substrates. Fixed diamond wire sawing has recently emerged as an alternative to slurry wire sawing as a means to shorten the time required for slicing and reduce the usage of slurry. The distribution of diamond grains on the wires strongly influences slicing performance in terms of material removal, surface topography, and subsurface damage. However, few studies have investigated this topic. This study established a model with which to simulate the distribution of diamond grains. Simulation results demonstrate that a higher density distribution reduces the rate of material removal because the loading is shared by the abrasives, thereby preventing the grains from penetrating deeply enough into the workpiece to facilitate the removal of material. Lower distribution density was shown to increase the loadings on the abrasives. These results demonstrate the importance of distribution density of diamond abrasives on the wire with regard to slicing performance.     

蓝宝石衬底片精密加工工艺研究

通过对蓝宝石衬底片精密加工的设备、工具、辅料、清洗等方面的研究,优化了衬底片加工工艺,提高了衬底片加工质量,且降低了加工成本.     

固着磨料抛光碳化硅反射镜的去除函数

进一步研究了采用固着磨料数控加工碳化硅反射镜的工艺,基于平转动加工方式的去除函数理论推导出了多丸片抛光盘的去除函数模型.根据趋近因子、曲线距离等结果对抛光盘运动偏心距及丸片间距等参数进行优化,由优化后的参数指导实验.理论模型与实验结果对比显示,理论最大去除率与实验数据的偏差为0.007 3 μm/min,偏差比例为5.58%;理论去除函数曲线与实验曲线的距离偏差Drms为0.084 9 μm,偏差比例为7.01%.在分析部分,引入填充因子来间接评价去除函数形状.实验结果很好地验证了理论模型的准确性.该模型对固着磨料磨具抛光的工艺过程具有很好的预测性,在加工碳化硅反射镜领域极大地弥补了使用散粒磨料工艺加工所带来的不足,使加工效率得以明显提升.