Ultra-precision grinding of 4H-SiC wafer by PAV/PF composite sol-gel diamond wheel

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110449
Author(s):  
Kaiping Feng ◽  
Tianchen Zhao ◽  
Binghai Lyu ◽  
Zhaozhong Zhou
Keyword(s):  
Surface Roughness ◽  
Low Temperature ◽  
Polyvinyl Alcohol ◽  
Feed Rate ◽  
Hot Pressing ◽  
Phenolic Resin ◽  
Sol Gel ◽  
Diamond Wheel ◽  
Sic Wafer ◽  
Better Than

To eliminate the deep scratches on the 4H-SiC wafer surface in the grinding process, a PVA/PF composite sol-gel diamond wheel was proposed. Diamond and fillers are sheared and dispersed in the polyvinyl alcohol-phenolic resin composite sol glue, repeatedly frozen at a low temperature of −20°C to gel, then 180°C sintering to obtain the diamond wheel. Study shows that the molecular chain of polyvinyl alcohol-phenolic resin is physically cross-linked to form gel under low-temperature conditions. Tested by mechanical property testing machines, microhardness tester, and SEM. The results show that micromorphology is more uniform, the strength of the sol-gel diamond wheel is higher, the hardness uniformity is better than that of the hot pressing diamond wheel. Grinding experiments of 4H-SiC wafer were carried out with the prepared sol-gel diamond wheel. The influence of grinding speed, feed rate, and grinding depth on the surface roughness was investigated. The results showed that by using the sol-gel diamond wheel, the surface quality of 4H-SiC wafer with an average surface roughness Ra 6.42 nm was obtained under grinding wheel speed 7000 r/min, grinding feed rate 6 µm/min, and grinding depth 15 µm, the surface quality was better than that of using hot pressing diamond wheel.

Optimal Grinding Condition of ZrO2 Ferrule for Optical Fiber Connector Using the Taguchi Method

2005 ◽  
Vol 297-300 ◽  
pp. 1545-1550 ◽  
Author(s):  
Chang Min Suh ◽  
Sang Chun Kim ◽  
Jung Sik Chae
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Optical Fiber ◽  
Feed Rate ◽  
Diamond Wheel ◽  
Cutting Depth ◽  
Maximum Surface ◽  
Grinding Speed ◽  
Optical Fiber Connector

In this paper, the effects of chamfering conditions on the surface roughness of ZrO2 ferrule applied to an optical fiber connector were investigated. The mesh number of the diamond wheel, the grinding speed of the spindle, the feed rate, and the initial cutting depth during grinding chamfer were regarded as the main parameters that have an effect on the surface roughness. Among these parameters, optimal combinations for chamfering conditions were obtained by using the Taguchi method. In addition, analytic values for maximum surface roughness (Rmax) estimated by the theoretical equations which were derived from the formative model of surface roughness on the grinding chamfer were compared with those of the experiments.

Influence of Processing Parameters on Surface Roughness in Micro Mill-Grinding Aluminium Alloy 6061

2014 ◽  
Vol 1017 ◽  
pp. 495-499
Author(s):  
Ya Dong Gong ◽  
Chao Wang ◽  
Jun Cheng ◽  
Xue Long Wen ◽  
Guo Qiang Yin
Keyword(s):  
Surface Roughness ◽  
Aluminium Alloy ◽  
Feed Rate ◽  
Processing Parameters ◽  
Micro Milling ◽  
Processing Conditions ◽  
Cutting Depth ◽  
Orthogonal Experiments ◽  
Alloy 6061 ◽  
Better Than

Orthogonal experiments of micro mill-grinding were conducted on aluminium alloy 6061. Electroplated CBN compound tools were used in machining. Surface topography and roughness of the machined workpieces were measured and analyzed. Influence rules of radial cutting depth,feed rate and spindle speed on surface roughness in micro mill-grinding were studied. The results were compared with those in micro milling. It shows that the influence rules of processing parameters on surface roughness in micro mill-grinding are approximately same with those in micro milling. And in the same processing conditions, the surface roughness of micro mill-grinding is better than that of micro milling. The minimum value of surface roughness Ra of micro mill-grinding is 0.609μm in the experiments.

Study on the Machining Parameters in Polishing Single-Crystal SiC Wafers with SG Films

2013 ◽  
Vol 589-590 ◽  
pp. 457-463 ◽  
Author(s):  
Zhi Du ◽  
Jing Lu ◽  
Cong Fu Fang ◽  
Hui Huang ◽  
Xi Peng Xu
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Smooth Surface ◽  
Sol Gel ◽  
Machining Parameters ◽  
Processing Quality ◽  
Rotating Speed ◽  
Single Crystal Sic ◽  
Sic Wafer ◽  
Diamond Abrasive

In this paper, diamond abrasive SG films were prepared by means of sol-gel technology for polishing single-crystal SiC wafers. The effects of machining parameters on processing quality including pressure, rotating speed and polishing time were investigated, respectively. The results indicated that the surface roughness decreased with increasing polishing time. While for pressure and rotating speed, there were inflections existing. Polishing SiC wafer under optimized machining parameters, an ultra smooth surface with the roughness of 3.7 nm could be achieved using 40 μm diamond grits.

Low temperature mullite formation from sol-gel precursors by hot pressing

1994 ◽  
Vol 9 (10) ◽  
pp. 2474-2475 ◽  
Author(s):  
S.K. Pradhan ◽  
A. Chatterjee ◽  
A. Datta ◽  
M. De ◽  
D. Chakravorty
Keyword(s):  
Low Temperature ◽  
Hot Pressing ◽  
Ambient Pressure ◽  
Sol Gel ◽  
The Other ◽  
Mullite Formation ◽  
Mullite Phase ◽  
Temperature Conditions ◽  
Other Hand ◽  
Similar Growth

The mullite phase has been synthesized by subjecting a suitably chosen precursor gel to different pressure and temperature conditions. At ambient pressure mullite phase grows at a temperature of 1400 °C when the gel is heated for 2 h. At a pressure of 24 bar, on the other hand, similar growth occurs at a temperature of 750 °C for 5 min.

Analysis of Effecting Factors on Surface Finish of Fused Silica Glass Grinding with Inclined Ball-Headed Diamond Wheel

2011 ◽  
Vol 175 ◽  
pp. 102-106 ◽  
Author(s):  
Ming Jun Chen ◽  
Ziang Li ◽  
Kang Jun Luo ◽  
Ying Chun Liang ◽  
Zhen Fang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Silica Glass ◽  
Diamond Wheel ◽  
Fused Silica ◽  
Grinding Process ◽  
Feed Speed ◽  
Average Grain Size ◽  
Fused Silica Glass ◽  
Better Than

Fused silica glass is widely used on the manufacture of optical apparatus and resonators due to it’s interesting optical and vibration properties. In order to machining the complex structures in the resonators and optical apparatus, grinding process with inclined ball-headed diamond wheel is discussed. Analytical model of the grinding process with inclined ball-headed diamond wheel was built firstly. Afterwards grinding experiments were conducted by varying the feed speed, the rotation speed, the cutting depth and the average grain size of the ball-headed diamond wheel. The machining surfaces were characterized by surface profiler to investigate the effect of the grinding parameters on the surface roughness. The measurement result shows the average grain size of the diamond wheel has important influence on the machining surface and the surface roughness at the groove bottom is better than the groove edge due to the wheel axis tilt angle.

Influences of Grinding Parameters on Flexural Strength in the Grinding of Li-Spinel Ferrites with Electroplated Diamond Wheel

2011 ◽  
Vol 487 ◽  
pp. 54-57
Author(s):  
L.P. Sun ◽  
Yu Guo Wang ◽  
Yang Yang ◽  
X.R. Yu ◽  
Bin Lin
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Feed Rate ◽  
Diamond Wheel ◽  
Optical Microscope ◽  
Spinel Ferrites ◽  
Wheel Speed ◽  
High Magnification ◽  
Cutting Depth ◽  
Grinding Parameters

Through the odd factor grinding experiment of microwave ferrite, the residual flexural strength and surface roughness after grinding were measured in different grinding parameters(wheel speed, feed rate, cutting depth, wheel size). The surface of microwave ferrites was observed in high magnification through an optical microscope after grinding, in order to show the variation of surface roughness in different grinding parameters. The results showed that with the increase of the surface roughness, the residual flexural strength increased.

Development of High Permeability Core Materials for Embeddable Inductors in Flexible Organic Substrates

2003 ◽  
Vol 769 ◽  
Author(s):  
C. K. Liu ◽  
P. L. Cheng ◽  
S. Y. Y. Leung ◽  
T. W. Law ◽  
D. C. C. Lam
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Circuit Board ◽  
Organic Substrates ◽  
Circuit Boards ◽  
High Permeability ◽  
Electrical Measurements ◽  
Different Temperatures ◽  
Spiral Inductors ◽  
Ceramic Tape

AbstractCapacitors, resistors and inductors are surface mounted components on circuit boards, which occupy up to 70% of the circuit board area. For selected applications, these passives are packaged inside green ceramic tape substrates and sintered at temperatures over 700°C in a co-fired process. These high temperature processes are incompatible with organic substrates, and low temperature processes are needed if passives are to be embedded into organic substrates. A new high permeability dual-phase Nickel Zinc Ferrite (DP NZF) core fabricated using a low temperature sol-gel route was developed for use in embedded inductors in organic substrates. Crystalline NZF powder was added to the sol-gel precursor of NZF. The solution was deposited onto the substrates as thin films and heat-treated at different temperatures. The changes in the microstructures were characterized using XRD and SEM. Results showed that addition of NZF powder induced low temperature transformation of the sol-gel NZF phase to high permeability phase at 250°C, which is approximately 350°C lower than transformation temperature for pure NZF sol gel films. Electrical measurements of DP NZF cored two-layered spiral inductors indicated that the inductance increased by three times compared to inductors without the DP NZF cores. From microstructural observations, the increase is correlated with the changes in microstructural connectivity of the powder phase.

Prediction of Surface Roughness and Optimization of Cutting Parameters in CNC Turning of Rotational Features

2020 ◽  
Vol 38 (8A) ◽  
pp. 1143-1153
Author(s):  
Yousif K. Shounia ◽  
Tahseen F. Abbas ◽  
Raed R. Shwaish
Keyword(s):  
Surface Roughness ◽  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Non Linear ◽  
Optimization Of Cutting Parameters

This research presents a model for prediction surface roughness in terms of process parameters in turning aluminum alloy 1200. The geometry to be machined has four rotational features: straight, taper, convex and concave, while a design of experiments was created through the Taguchi L25 orthogonal array experiments in minitab17 three factors with five Levels depth of cut (0.04, 0.06, 0.08, 0.10 and 0.12) mm, spindle speed (1200, 1400, 1600, 1800 and 2000) r.p.m and feed rate (60, 70, 80, 90 and 100) mm/min. A multiple non-linear regression model has been used which is a set of statistical extrapolation processes to estimate the relationships input variables and output which the surface roughness which prediction outside the range of the data. According to the non-linear regression model, the optimum surface roughness can be obtained at 1800 rpm of spindle speed, feed-rate of 80 mm/min and depth of cut 0.04 mm then the best surface roughness comes out to be 0.04 μm at tapper feature at depth of cut 0.01 mm and same spindle speed and feed rate pervious which gives the error of 3.23% at evolution equation.

Low-Temperature Post-Oxidation Annealing Using Atomic Hydrogen Radicals Generated by High-Temperature Catalyzer for Improvement in Reliability of Thermal Oxides on 4H-SiC

2006 ◽  
Vol 527-529 ◽  
pp. 999-1002
Author(s):  
Junji Senzaki ◽  
Atsushi Shimozato ◽  
Kenji Fukuda
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Atomic Hydrogen ◽  
High Reliability ◽  
Hydrogen Atmosphere ◽  
Exposed Sample ◽  
New Apparatus ◽  
Hydrogen Radical ◽  
Hydrogen Radicals ◽  
Sic Wafer

Low-temperature post-oxidation annealing (POA) process of high-reliability thermal oxides grown on 4H-SiC using new apparatus that generates atomic hydrogen radicals by high-temperature catalyzer has been investigated. Atomic hydrogen radicals were generated by thermal decomposition of H2 gas at the catalyzer surface heated at high temperature of 1800°C, and then exposed to the sample at 500°C in reactor pressure of 20 Pa. The mode and maximum values of field-to-breakdown are 11.0 and 11.2 MV/cm, respectively, for the atomic hydrogen radical exposed sample. In addition, the charge-to-breakdown at 63% cumulative failure of the thermal oxides for atomic hydrogen radical exposed sample was 0.51 C/cm2, which was higher than that annealed at 800°C in hydrogen atmosphere (0.39 C/cm2). Consequently, the atomic hydrogen radical exposure at 500°C has remarkably improved the reliability of thermal oxides on 4H-SiC wafer, and is the same effect with high-temperature hydrogen POA at 800°C.

scholarly journals Hydrolytic Modification of SiO2 Microspheres with Na2SiO3 and the Performance of Supported Nano-TiO2 Composite Photocatalyst

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2553
Author(s):  
Yu Tu ◽  
Weihua Ao ◽  
Chunhong Wang ◽  
Tianyu Ren ◽  
Lijuan Zhang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Active Surface ◽  
Hydroxyl Groups ◽  
Nano Tio2 ◽  
Amorphous Sio2 ◽  
Composite Photocatalyst ◽  
Sio2 Shell ◽  
Functional Efficiency ◽  
Sio2 Microspheres ◽  
Better Than

Modified microspheres (SiO2-M) were obtained by the hydrolytic modification of silicon dioxide (SiO2) microspheres with Na2SiO3, and then, SiO2-M was used as a carrier to prepare a composite photocatalyst (SiO2-M/TiO2) using the sol-gel method; i.e., nano-TiO2 was loaded on the surface of SiO2-M. The structure, morphology, and photocatalytic properties of SiO2-M/TiO2 were investigated. Besides, the mechanism of the effect of SiO2-M was also explored. The results show that the hydrolytic modification of Na2SiO3 coated the surface of SiO2 microspheres with an amorphous SiO2 shell layer and increased the quantity of hydroxyl groups. The photocatalytic performance of the composite photocatalyst was slightly better than that of pure nano-TiO2 and significantly better than that of the composite photocatalyst supported by unmodified SiO2. Thus, increasing the loading capacity of nano-TiO2, improving the dispersion of TiO2, and increasing the active surface sites are essential factors for improving the functional efficiency of nano-TiO2. This work provides a new concept for the design of composite photocatalysts by optimizing the performance of the carrier.

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