CN200710047371．5基于光纤激光器的激光辅助机械金刚石砂轮修整方法

本发明公开了一种基于光纤激光器的激光辅助机械金刚石砂轮方法,具体步骤为：1．将光纤激光器安装夹持在被修整金刚石砂轮的上方,激光束经聚焦后照射到被修整金刚石砂轮表面形成温度场软化金刚石砂轮的结合剂材料;2．将被修整的金刚石砂轮安装在磨床上作旋转运动,单点金刚石修整笔沿金刚砂轮表面轴向作往复移动,对砂轮表面进行修整,解决了数控光学曲线磨床和工具磨床上金刚石砂轮无法在线修整的难题,     

超硬磨料砂轮不同介质中电火花修整试验研究

超硬磨料砂轮的电火花修整受到极间放电间隙的限制,采用传统的放电介质条件难以达到粗粒度砂轮的修整要求。为此,结合混粉放电加工机理,提出混粉介质中的电火花修整方法,进行压缩空气、去离子水雾和混粉去离子水雾3种介质及不同放电参数下的放电间隙对比试验研究,并开展金刚石砂轮修整和工件磨削试验。试验结果表明:混粉介质电火花修整的放电间隙最大,能提高粗粒度青铜结合剂金刚石砂轮的修整效率,同时优化砂轮修整后的表面形貌、磨粒突出状况和磨削性能。在开路电压为90 V、峰值电流为13.33 A及占空比为50%的最佳放电参数下,混粉介质的电火花修整效率与前2种介质相比可提高28.2%～50.0%;且加入的SiO₂粉末使砂轮表面的Si元素分布更均匀、含量更高,进而提高其耐磨性。      

超精密晶圆减薄砂轮及减薄磨削装备研究进展

在芯片制程的后道阶段,通过超精密晶圆减薄工艺可以有效减小芯片封装体积,导通电阻,改善芯片的热扩散效率,提高其电气性能、力学性能。目前的主流工艺通过超细粒度金刚石砂轮和高稳定性超精密减薄设备对晶圆进行减薄,可实现大尺寸晶圆的高精度、高效率、高稳定性无损伤表面加工。重点综述了目前超精密晶圆减薄砂轮的研究进展,在磨料方面综述了机械磨削用硬磨料和化学机械磨削用软磨料的研究现状,包括泡沫化金刚石、金刚石团聚磨料、表面微刃金刚石的制备方法及磨削性能,同时归纳总结了软磨料砂轮的化学机械磨削机理及材料去除模型。在结合剂研究方面,综述了金属、树脂和陶瓷3种结合剂的优缺点,以及在晶圆减薄砂轮上的应用,重点综述了目前在改善陶瓷结合剂的本征力学强度及与金刚石之间的界面润湿性方面的研究进展。在晶圆减薄超细粒度金刚石砂轮制备方面,由于微纳金刚石的表面能较大,采用传统工艺制备砂轮会导致磨料发生团聚,影响加工质量。在此基础上,总结论述了溶胶–凝胶法、高分子网络凝胶法、电泳沉积法、凝胶注模法、结构化砂轮等新型工艺方法在超细粒度砂轮制备方面的应用研究,同时还综述了目前不同的晶圆减薄工艺及超精密减薄设备的研究进展,并指出未来半导体加工工具及装备的发展方向。     

陶瓷结合剂金刚石砂轮修整的研究(Ⅲ)——杯形砂轮修整器的修整机理

在前两篇文章中,笔者提出了一种以杯形砂轮为工具的金刚石砂轮修整方法。本文探讨了以该方法修整陶瓷结合剂金刚石砂轮的机理。主要结论如下:(1)杯形砂轮的修整作用主要取决于从GC砂轮上脱落下来的磨粒对金刚石磨粒和结合剂桥的冲击。(2)杯形砂轮越软,其上脱落下来的磨粒越大,修整效率越高,但金刚石砂轮表面越粗糙。(3)用烧结体多点金刚石笔修整时,从最外表面开始,金刚石砂轮表层磨粒依次被金刚石笔削去。(4)作为添加材料加入到陶瓷结合剂金刚石砂轮中的碳化硅磨粒,其顶端在磨削初期即被磨平。(5)磨削难磨材料时,最好使用无添加材料的陶瓷结合剂金刚石砂轮。     

钎焊金刚石砂轮修整实验研究

单层钎焊金刚石砂轮的圆度轮廓精度由于受磨料粒径和钎焊结合剂层高度不均匀等因素的影响而使其难以在工程陶瓷等硬脆材料精密磨削中应用.然而单层钎焊金刚石砂轮的修整是直接对金刚石磨粒进行微量的磨损,修整难度大、效率低,因此,探讨快捷且精密的整形方法就成了解决其应用问题的关键技术之一.在本文研究中,分别采用铁基金刚石烧结磨块、钎焊细粒度金刚石板和氧化铝磨块三种整形工具对钎焊金刚石砂轮进行了磨削法整形实验研究,实验结果表明利用氧化铝磨块进行磨削修整效率极低;钎焊金刚石板磨削修整虽然效率高,但是对砂轮表面金刚石磨粒造成大量破碎磨损;铁基金刚石烧结磨块在整形过程中可稳定地以磨平方式磨损砂轮表面金刚石磨粒,经精密整形后的砂轮圆度轮廓精度较高,用其磨削工程陶瓷时工件表面的犁沟和裂纹明显减少.     

金刚石微粉砂轮软弹性修整研究（Ⅰ）：——软弹性修整法及其机理

金属结合剂金刚石砂轮，尤其是金属结合剂金刚石微粉砂轮，很难采用磨削法修整。针对磨削修整法的不足发明了软弹性修整法。本文讨论了软弹性修整法的修整机理，介绍了软弹性修整方法的修整装置。     

金刚石砂轮V形尖端的数控对磨微细修整技术

针对金刚石砂轮V形尖端的微细修整困难的问题,开发出一种对磨成型的V形尖端修整技术。在数控修整中,砂轮作V形的直线插补运动与修整工具对磨,逐渐被修整成V形尖端。本实验中修整工具分别是#600和#180绿碳化硅(GC)油石,砂轮分别为SD 400和SD 600金刚石砂轮。实验结果表明,较细粒度的修整工具不仅可以将砂轮V形尖端修整出更小的圆弧半径,而且也能够将微小磨粒修锐得更锋利,从而使加工的单晶硅微沟槽形状更加整齐。此外,采用修整后的圆弧半径小于20μm的SD 600金刚石砂轮V形尖端可以实现光纤石英微阵列沟槽的微细加工,也可以在SiC陶瓷和WC合金基板上加工出微锥塔阵列空间的功能表面。因此,数控对磨在位修整的工艺可以用于金刚石砂轮V形尖端的微细修整,实现硬脆性基板的微细磨削加工。     

成形金刚石砂轮的电解修整阴极设计

根据电解成形理论设计阴极工具形状，用于金属结合剂成形金刚石砂轮的电解修整。在成形砂轮电解修整电场模型的基础上，应用有限元法求解电场中拉普拉斯方程几何反问题。假定初始阴极形状，施加阳极边界条件，从砂轮阳极表面开始逐层计算电位分布，求得修整间隙区域的等电位线，从而得到修整阴极工具曲线族。论文选择圆形、椭圆形和抛物线形三种典型成形砂轮廓形，设计出它们的修整阴极工具形状，并分析了成形砂轮廓形对修整阴极工具形状的影响。计算结果表明：设计阴极形状的曲率大于成形砂轮轮廓的曲率，且随着x坐标和成形砂轮轮廓曲率的增大，设计阴极与砂轮廓形的偏差增加。论文提供了一种计算机辅助阴极工具设计方法。     

金刚石微粉砂轮软弹性修整研究（V）：软弹性修锐

本文讨论软弹性修整法用于金属结合剂金刚石微粉砂轮修锐效果及修锐参数选择，并从微观的角度对软弹性修锐过程及修锐后砂轮表面形貌进行了分析。     

金刚石微粉砂轮软弹性修整研究（Ⅴ）──软弹性修锐

本文讨论软弹性修整法用于金属结合剂金刚石微粉砂轮修锐的修锐效果及修锐参数选择，并从微观的角度对软弹性修锐过程及修锐后砂轮表面形貌进行了分析。     

金刚石砂轮的ECD修锐和整形研磨及其对硬脆材料的加工

为研究金属结合剂金刚石砂轮切削刃修锐整形对硬脆材料加工表面形态的影响,先通过接触放电法对SD600金属结合剂砂轮切削刃进行修锐,再用整形研磨方法对砂轮表面金刚石磨粒的不同切削刃高度进行整形研磨,最后用修整好的砂轮磨削加工用于光学设备的硼硅玻璃、石英玻璃、石英晶体和蓝宝石等几种硬脆材料.结果表明:硬脆材料粗糙度的改善程度...     

Mirror surface grinding for brittle materials with in-process electrolytic dressing

Use of a diamond wheel with superabrasive is required for mirror-like surface grinding of brittle materials. However, conventional dressing methods cannot apply to the diamond wheel with superabrasive. Recently, an electrolytic dressing method was developed for use with a cast iron-bonded diamond wheel and superabrasive. This technique can replace lapping and polishing. Using electrolytic dressing, surface roughness of the workpiece was improved significantly, and the grinding force was very low and the continuity of the grinding force was also improved. The purpose of this study was to achieve mirror-like surface grinding of ferrite with electrolytic dressing of a metal-bonded diamond wheel. For application of ultraprecision grinding for brittle material, superabrasive, air spindle, and in-process electrolytic dressings were used. Additionally, the effects of pick current and pulse width on ground surface were investigated, and suitable dressing conditions for ferrite were determined.     

在线电解修整(ELID)超精密磨削中的金刚石磨具特性研究

ELID(Electrolytic In-process Dressing)磨削技术是在电化学加工、电解磨削原理基础上发展起来的一项磨削新技术,主要用于硬脆材料超精密磨削过程中金属基结合剂超硬微细磨粒砂轮的在线修整.本文以金刚石微粉砂轮在线电解修整(ELID)磨削氮化硅陶瓷为例,着重研究了磨具特性对硬脆材料超精密磨削过程的影响.研究表明,磨具组织沿砂轮圆周的不均匀性将会导致砂轮表面钝化膜状态的不一致,这将直接影响砂轮局部参与切削的磨粒数量,影响单个磨料的实际磨削厚度.这首先将对工件表面的磨削质量,特别是对表面粗糙度产生直接影响,同时也非常不利于实现材料的高效去除.     

碟轮修整单层钎焊金刚石砂轮的试验研究

单层钎焊金刚石砂轮在制作完成之初由于砂轮基体加工存在误差以及磨粒粒径大小不一等原因造成磨粒等高性不一致,这使其难以在硬脆材料的精密磨削中得到广泛的应用。采用自制的钎焊碟轮对80/100#单层钎焊金刚石砂轮进行了修整试验研究。在修整试验前后跟踪了砂轮磨粒等高性的变化,进行了SiC陶瓷的磨削试验,并观测了工件表面质量的变化情况。试验结果表明:采用此方法能够实现单层钎焊金刚石砂轮的高效精密修整。修整试验结束后砂轮磨粒等高性较好,磨削SiC陶瓷的表面质量得到明显改善,表面粗糙度Ra值达到了0.1μm以下。     

Precision grinding of optical glass with laser micro-structured coarse-grained diamond wheels

This paper presents a series of micro-structured coarse-grained diamond wheels for optical glass surface grinding aiming to improve the grinding performance, especially subsurface damage. The 150 μm grit size, single layer electroplated diamond grinding wheels with different interval micro-groove arrays were manufactured by nanosecond pulsed laser, successfully. The influence of micro-structures on surface roughness and subsurface damage was investigated. Compared with conventional coarse-grained diamond wheel, the subsurface damage depth was reduced effectually from 5 to 1.5 μm, although the better surface roughness was not obtained by the micro-structured coarse-grained diamond wheel. In addition, the surface roughness and subsurface damage depth were both reduced with the decreasing interval of micro-groove arrays.     

A fundamental study on the mechanism of electrolytic in-process dressing (ELID) grinding

Demands for high quality surface finish, dimensional and form accuracy are required for optical surfaces and it is very difficult to achieve these using conventional grinding methods. Electrolytic in-process dressing (ELID) grinding is one new and efficient method that uses a metal-bonded diamond grinding wheel in order to achieve a mirror surface finish especially on hard and brittle materials. However, studies reported so for have not explained the fundamental mechanism of ELID grinding and so it has been studied here by conducting experiments to establish optimal grinding parameters to obtain better surface finish under various in-process dressing conditions. In this research the results show that the cutting forces are unstable throughout the grinding process due to the breakage of an insulating layer formed on the surface of the grinding wheel; however, a smoother surface can be obtained using a high dressing current duty ratio at the cost of high tool wear. ELID grinding is efficient for feed rates of less than 400 mm/min, and surface cracks are observed when it exceeds this limit.     

Ground surface integrity of granite by using dry electro-contact discharge dressing of #600 diamond grinding wheel

Dry electro-contact discharge (ECD) dressing of metal-bonded #600 diamond grinding wheel is proposed for grinding of various granites. As compared to mechanical GC dressing, Dry ECD dressing can not only protrude fine diamond grains from wheel metal-bond without any damage, but also eliminate bond-tail behind the protruded grain. The objective is to understand how the synthetic factors including granite structure, grinding parameters and dressing method influence the ground surface integrity of multi-crystal granite such as surface roughness and surface crack appearance in contrast to homogeneous optic glass. First a micron-scale indentation experiment was carried out to display the growth mechanism of micro-cracks on polished surface, then Dry ECD dressing and mechanical GC dressing were carried out in grinding experiment, respectively, finally surface roughness and micro-surface crack were investigated in connection with granite crystal size, work speed and dressing method. It is found that in almost all cases the multi-crystal granite has always worse ground surface than homogeneous optic glass even if grinding parameter is changed. Moreover, the improvement of ground surface for granite is more sensitive to grain protrusion feature than that for optic glass. Although it is very difficult to find out obvious relationship between surface roughness and grinding parameter such as work speed, it has a good correlation with granite structure such as granite crystal size: it decreases with the increase of the granite crystal size. It is concluded that Dry ECD dressing may more greatly improve the ground surface integrity of various granites than mechanical GC dressing.     

先进光学磨削中杯形修整技术开发及应用

对于金刚石砂轮修整,尤其是有高精度要求的圆弧金刚石砂轮,杯形砂轮修整技术可以获得较好的砂轮磨削性能以及修整效率。本文开发了配套超精密平面磨床使用的杯形修整器,分析了其机械误差影响,并完成了修整实验及砂轮表面测量及半径拟合处理,从宏观上考察了该修整器对砂轮磨削性能的提高,结果证明该修整器可以进行有效修整,提高了加工工具精度,能满足金刚石砂轮修整使用要求。     

超硬磨料砂轮自动化复合修整机床CAM系统开发

为了使复合修整方法中的多种工艺更系统地整合,提高成形砂轮的修整效率,结合自主研制的激光–机械复合修整装备,开发一套CAM系统,可根据不同砂轮截面形状,自动规划多工艺、多修整策略下的修整轨迹,计算平面三轴联动修整刀路,自动生成加工代码,同时设计可视化界面仿真加工过程。对青铜结合剂金刚石砂轮进行修整试验,结果表明：该系统可在保证机床不发生碰撞和过切的情况下,生成激光粗修、半精修及机械精修的加工程序,大幅提高复合修整方法的编程效率,修整后的砂轮轮廓误差在9.1μm以内,圆跳动误差为6.1μm。