Fabrication of Ultra-Fine Abrasive Polishing Pads by Gel Technique

2006 ◽  
Vol 532-533 ◽  
pp. 468-471 ◽  
Author(s):  
Juan Liu ◽  
Yi Qing Yu ◽  
Xi Peng Xu
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Silicon Wafer ◽  
Optical Microscope ◽  
Mirror Surface ◽  
Polishing Pad ◽  
Average Grain Size ◽  
Gel Technique ◽  
Surface Morphologies ◽  
Polishing Pads

In this paper, an experimental study was carried out to fabricate a new kind of ultra-fine abrasive polishing pad by means of gel technology. The polishing pad was then used to polish silicon wafer on a nano-polishing machine. Optical microscope and ZYGO 3D surface analyzer were applied to observe the surface morphologies of the silicon wafer. Meanwhile, surface morphology of ultra-fine abrasive polishing pad was observed by ESEM. No obvious gathering of ultra-fine grains were found on the ultra-fine abrasive pad. The surface roughness (Ra) of the silicon wafer was reduced to 0.3nm after being polished by the abrasives with average grain size of 10μm. Mirror surface can be realized after being polished with the polishing pad.

Polishing Silicon Wafers with the Nanodiamond Abrasive Tools Prepared by Sol-Gel Technique

2011 ◽  
Vol 496 ◽  
pp. 1-6 ◽  
Author(s):  
Guang Qiu Hu ◽  
Jing Lu ◽  
Xi Peng Xu
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Sol Gel ◽  
Optical Microscope ◽  
Mirror Surface ◽  
Atomic Force ◽  
Polishing Pad ◽  
Gel Technique ◽  
Abrasive Tools ◽  
Surface Morphologies

In this paper, in order to avoid aggregate of nanodiamonds and reduce the damage problem caused by the hard abrasives during polishing, a kind of ultra-fine nanodiamond abrasive polishing pad was fabricated by means of sol-gel technology. The polishing pad was then used to polish silicon wafer on a nano-polishing machine. The surface morphologies and roughness were measured by both optical microscope and atomic force microscope (AFM). It is found that it was easy to machine the silicon wafer to mirror surface after polishing with the nanodiamond pad. And the surface roughness of the silicon wafer was reduced to 0.402 nm.

Influences of Machining Parameters on Silicon Wafer Polished with Gel-Coupled Ultra-Fine Abrasive Polishing Pads

2007 ◽  
Vol 359-360 ◽  
pp. 279-284
Author(s):  
Juan Liu ◽  
Xi Peng Xu
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Optical Microscope ◽  
Machining Parameters ◽  
Machining Time ◽  
Rotating Speed ◽  
Polishing Pad ◽  
Surface Morphologies ◽  
Polishing Pads ◽  
Polishing Pressure

In this paper, a newly developed ultra-fine abrasive polishing pad by gel technology was adopted to polish silicon wafer on a nano-polishing machine. In order to evaluate the machining performances of the polishing pad, the influences of abrasive sizes, abrasive concentration and polishing parameters (pressure, rotating speed and machining time) on the silicon wafer were investigated respectively. Optical microscope and ZYGO 3D surface analyzer were applied to examine the surface morphologies and surface roughness of the polished silicon wafer respectively. The experimental results showed that the surface roughness of silicon wafer decreased with the decreasing of abrasive grits and the increasing of abrasive concentration and polishing parameters (pressure, rotating speed and polishing time) when polishing silicon wafer with the polishing pad containing Al2O3 abrasive. When abrasive concentration, polishing pressure and polishing time reached certain values, few changes would happen for the silicon wafer.

Effect of Tightening Speed on the Torque-Tension and Wear Pattern in Bolted Connections

2006 ◽  
Author(s):  
Sayed A. Nassar ◽  
Ramanathan M. Ranganathan ◽  
Saravanan Ganeshmurthy ◽  
Gary C. Barber
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Surface Roughness ◽  
Initial Level ◽  
Zinc Coating ◽  
Optical Microscope ◽  
Wear Pattern ◽  
Highly Sensitive ◽  
Contact Surfaces ◽  
Scanning Electron

This experimental study investigates the effect of tightening speed and coating on both the torque – tension relationship and wear pattern in threaded fastener applications. The fastener torque – tension relationship is highly sensitive to normal variations in the coefficients of friction between threads and between the turning head and the surface of the joint. Hence, the initial level of the joint clamp load and the overall integrity and reliability of a bolted assembly is significantly influenced by the friction coefficients. The effect of repeated tightening and loosening is also investigated using M12, Class 8.8, fasteners with and without zinc coating. The torque – tension relationship is examined in terms of the non-dimensional nut factor K. The wear pattern is examined by monitoring the changes in surface roughness using a WYKO optical profiler and by using a LECO optical microscope. A Hitachi S-3200N Scanning Electron Microscope (SEM) is used to examine the contact surfaces, under the fastener head, after each tightening/loosening cycle. Experimental data on the effect of variables and the tightening speed, fastener coating and repeated tightening on the nut factor are presented and analyzed for M8 and M12, class 8.8, fasteners.

Grain Structure and Surface Roughness of Four Commercial NiTi Orthodontic Archwires

2017 ◽  
Vol 266 ◽  
pp. 257-263
Author(s):  
Wassana Wichai ◽  
Rutchadakorn Isarapatanapong ◽  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Optical Microscope ◽  
Grain Structure ◽  
Wire Surface ◽  
Average Grain Size ◽  
Electron Mode ◽  
The Mean ◽  
The Wire ◽  
Orthodontic Archwires

This study investigated four commercially available NiTi orthodontic archwires from different manufactures for their grain structure and surface roughness.Four commercially available pre-formed NiTi orthodontic archwire (Ormco, Sentalloy, Highland and NIC) with diameter 0.016 x 0.022 inch2 were tested. The wire samples were polished and etched to evaluate the morphology and structure of wire surface. Each NiTi archwire was investigated under a reflected light microscope of an Optical Microscope to analyze its grain structure and size, in longitudinal surfaces. The surfaces of wire were qualitatively examined in the secondary electron mode at common magnification (500X). The surface roughness was also evaluated by a surface roughness tester. The descriptive statistic was evaluated the mean and standard deviation of surface roughness and Medcale T-Test was to test the mean difference of the surface roughness in each brands. This study showed an average grain size of 2-8 μm for each NiTi archwire. The wire surface of Ormco and Highland showed straiations along the longitudinal axes, however Sentalloy and NIC showed small pores on the wire surface. The surface roughness was 0.09 μm for Highland, 0.25 μm for Sentalloy, 0.28 μm for Ormco and 0.46 μm for NIC archwire. The Highland was smoothest and NIC was the roughest. There were in significant (p < 0.05) difference of surface roughness of each brands. The results showed that the four manufactures NiTi archwires were different in grain size, wire surface and surface roughness. During clinical application, these archwires may exhibit different mechanical properties, such as strength, hardness, ductity, and friction because of their microstructure.

A New Polishing Pad of EVA-Adhesive-Dressed-with-SiC-Grits Polishing Face and its Applications in Silicon Wafer Polishing

2010 ◽  
Vol 126-128 ◽  
pp. 539-544
Author(s):  
Sung Lin Tsai ◽  
Fuang Yuan Huang ◽  
Biing Hwa Yan ◽  
Yao Ching Tsai
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Silicon Surface ◽  
Ethylene Vinyl Acetate ◽  
Grit Size ◽  
Taguchi Methods ◽  
Absorption Time ◽  
Polishing Pad ◽  
Wheel Turning ◽  
Wafer Polishing

This paper presents a new polishing pad with polishing silicon surface composed of a layer of Ethylene-vinyl acetate (EVA) adhesive pad coated with SiC grits. A set of polishing parameters: coating SiC grit size, concentration of SiC grit in slurry, polishing load, polishing wheel turning speed, and absorption time of polishing pad were identified with the Taguchi Methods for optimum polishing effect in terms of roughness of polished silicon surface. A surface roughness of 0.026 μm Ra can be obtained with the following values: grit size at 1.2 μm (both coated on pad and mixed in slurry), concentration of SiC grit in slurry at 25%, polishing load at 50 gram, turning speed at 10,000 rpm, absorption time of polishing pad at 15 minutes.

Fabrication of Ultra-Fine Diamond Abrasive Tools by Sol-Gel

2004 ◽  
Vol 471-472 ◽  
pp. 426-430 ◽  
Author(s):  
Juan Liu ◽  
Xi Peng Xu
Keyword(s):  
Experimental Study ◽  
Physical Properties ◽  
Sol Gel ◽  
Optical Microscope ◽  
Diamond Tools ◽  
Fine Diamond ◽  
Abrasive Tools ◽  
Grinding Machine ◽  
Surface Morphologies ◽  
Diamond Abrasive

In this paper, an experimental study was carried out to fabricate a new kind of ultra-fine diamond abrasive tools by means of sol-gel. The physical properties of the new diamond abrasive tools were evaluated in terms of the bulk density and hardness. The ultra-fine diamond tools were then used to polish granite on a vertical spindle grinding machine. SEM and optical microscope were applied to observe the surface morphologies of the diamond tools and granite. No obvious gathering of ultra-fine diamond grains were found in the new diamond abrasive tools, which exhibited a good wear-resistant ability in polishing. The granite surfaces polished by the new diamond tools were found to be basically smooth except few cracks originally existing in the granite.

Study on the Structure and Properties of Surface Nanocrystallized Zr-4

2011 ◽  
Vol 415-417 ◽  
pp. 660-665
Author(s):  
Cong Hui Zhang ◽  
Da Li Liu ◽  
Xin Zhe Lan ◽  
Xi Cheng Zhao
Keyword(s):  
Surface Roughness ◽  
Surface Layer ◽  
Processing Time ◽  
Optical Microscope ◽  
Surface Mechanical Attrition Treatment ◽  
Structure And Properties ◽  
Nanostructured Surface ◽  
Grain Sizes ◽  
Mechanical Attrition ◽  
Average Grain Size

A nanostructured surface layer was obtained on the surface of Zr-4 by surface mechanical attrition treatment(SMAT). The structure and the properties of the SMAT sample were analyzed by means of the optical microscope, hardness and polarization curve testing. The results show that， when processing time for 5min, the average grain sizes on the surface layer can be refined to 23nm. The average grain size by SMAT-ed for 15min is 20nm, which is the smallest. The microhardness have a significant increase, the surface roughness also increase, and the corrosion resistance reduce in 1mol H2SO4solution.

Surface Characterization of Silicon Wafers Polished by Three Different Methods

2011 ◽  
Vol 487 ◽  
pp. 233-237 ◽  
Author(s):  
Guang Qiu Hu ◽  
Jing Lu ◽  
Jian Yun Shen ◽  
Xi Peng Xu
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Surface Characterization ◽  
Sol Gel ◽  
Silicon Wafers ◽  
Abrasive Tool ◽  
Atomic Force ◽  
Polishing Pad ◽  
Fixed Abrasive ◽  
Free Abrasive

The surface roughness and surface morphology of silicon wafers polished by three different polishing methods were analyzed in this paper. A polishing pad was prepared by means of sol-gel technology as semi-fixed abrasive tool. An electroplated polishing pad was chosen as fixed abrasive tool. And a polishing cloth was chosen as free abrasive tool. The results showed that the surface of silicon wafer polished by the sol-gel polishing pad was superior to the other two. It was easy to get mirror effect with few scratches while the free abrasive and fixed abrasive got lots of scratches on 23silicon wafers. The surface roughness of silicon wafer polished by the sol-gel polishing pad reached 1.41nm measured by atomic force microscope (AFM).

The Experimental Study on Lapping and Polishing of Metal Micro-Coil Based on Silicon Wafer

2006 ◽  
Vol 304-305 ◽  
pp. 422-425
Author(s):  
B.D. Liu ◽  
Jia Liang Guan ◽  
D.SH. Li ◽  
H.Q. Li
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Silicon Wafer ◽  
Difficult Problem ◽  
Machining Efficiency ◽  
Electromagnetic Relay ◽  
Deposited Metal

The removal of redundant layer of deposited metal of the micro coils is one difficult problem in the fabricating of micro-mechanical electromagnetic relay. In view of the machining efficiency and quality, the paper introduced lapping and polishing technology. The paper also analyzed the characteristic of lapping and polishing and introduced the appropriate abrasives. Then the main procedures were presented and the measuring result was given in the paper. The surface roughness of the coil could satisfy the next layer fabricate requirements of the micro-mechanical electromagnetic relay. At last the paper concluded the optimized lapping and polishing parameters.

Effect of Shape and Size of Polishing Pad on Material Removal Characteristic

2011 ◽  
Vol 101-102 ◽  
pp. 1014-1018
Author(s):  
Di Zheng ◽  
Yong Jiang Yu ◽  
Xian Hua Zhang ◽  
Xiao Jun Zhao ◽  
Yuan Wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Polishing Pad ◽  
Material Removal Model ◽  
The Law ◽  
Polishing Pads ◽  
Removal Model ◽  
Polishing Efficiency ◽  
Shape And Size

The objective of this paper is to investigate the effect of shape and size of polishing pad on the material removal characteristics in the NC polishing. The material removal model was established based on Preston equation. The law of the effect of shape and size of polishing pad on the model was simulated. Experiments were carried out. Results showed that both of the shape and size of polishing pads influence the shape of material removal curves, polishing efficiency, and surface roughness. The amount of removed material increases with the increasing of size of polishing pad.

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