金刚石与磨料磨具工程

2020, 40(4): 1-4.

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Manufacturing technique and industry status of semiconductor silicon wafers

YAN Zhirui, KU Liming, BAI Dujuan, CHEN Haibin, WANG Yongtao

2020, 40(4): 5-11. doi: 10.13394/j.cnki.jgszz.2020.4.0001

Abstract(774)

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Based on the introduction of the basic theory and manufacturing technique of semiconductor silicon wafers, this article analyzes the current global industry situation, industrial development trends and characteristics of silicon wafers. It then discusses, based on the actual situation, the opportunities, the challenges and the existing problems to develop silicon industry in China.

Review of monocrystalline silicon slicing technology

GE Peiqi, CHEN Zibin, WANG Peizhi

2020, 40(4): 12-18. doi: 10.13394/j.cnki.jgszz.2020.4.0002

Abstract(766)

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Slicing of monocrystalline silicon is an important process in integrated circuit industry and photovoltaic industry, where the slicing method and qualities directly affect the yield of sliced wafers and the cost of wafer substrate and photovoltaic solar cells. With the increase of wafer size, wire sawing technology has become the mainstream slicing technology of monocrystalline silicon. To realize high efficiency, precision and low crack damage slicing of monocrystalline silicon, this study presents two most commonly used slicing methods and their slicing characteristics, reviews the slicing mechanism and micro processing analysis of diamond wire sawing technology, summarizes the research on slicing induced crack damage and its suppression methods, and points out the development prospects and challenges of monocrystalline silicon slicing technology.

Influence of structure of vitrified bond diamond grinding wheel on its performance

DING Yulong, MIAO Weipeng, LUO Miaodi, FENG Bingqiang, ZHU Jianhui, ZHAO Yanjun, BAO Hua

2020, 40(4): 19-23. doi: 10.13394/j.cnki.jgszz.2020.4.0003

Abstract(552)

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The influence of structure of vitrified bond diamond grinding wheel on the grinding performance for silicon wafer was studied. The influence of structure on grinding wheel wear and spindle current was evaluated, and the surface roughness and surface morphology of ground silicon wafer were measured. The results show that the spindle current decreases from the highest 7.0 A to 6.3 A with the increase of the porosity of grinding wheel tissue. On the other hand, the wear rate of grinding wheel shows the opposite rule, which is from 1.423 8 μm per piece to 2.525 2 μm per piece, as the porosity of the wheel ranges from its valley to the peak. It is also found that the structure has little influence on the surface roughness of the workpiece, which is 7.67 nm, 7.47 nm and 7.37 nm, respectively. However, when the pore diameter is too large and the hole wall becomes thinner, deep scratches will appear on the surface of the workpiece and the grinding quality of silicon wafer will be deteriorated.

Review on chemical mechanical polishing of silicon wafers

XU Jiahui, KANG Renke, DONG Zhigang, WANG Ziguang

2020, 40(4): 24-33. doi: 10.13394/j.cnki.jgszz.2020.4.0004

Abstract(1124)

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With the increase of wafer thickness and the decrease of chip thickness, the amount of material removal increases in the process of wafer processing, and the problem of improving the processing efficiency has become one of the research hotspots. Due to the complexity of chemical mechanical polishing process, the quality of silicon wafer after polishing is affected by many factors, including the technical parameters of polishing equipment, the properties of consumables (polishing pad and polishing fluid) and the contact stress state of silicon wafer during polishing. In this paper, the research progress of chemical mechanical polishing technology for silicon wafer is introduced. The factors affecting the surface quality and material removal rate of silicon wafer, such as polishing fluid, polishing pad and polishing pressure, are discussed, and the advanced equipment used in chemical mechanical polishing of silicon wafer is reviewed.

Effect of hot pressing parameters on the mechanical properties of WC-Cu matrix

LIU Xin, ZHANG Weilong, ZHAO Xiaojun, TAN Songcheng, DUAN Longchen

2020, 40(4): 34-40. doi: 10.13394/j.cnki.jgszz.2020.4.0005

Abstract(250)

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WC-Cu based diamond bit matrix is widely used in deep drilling. To improve the service performance of diamond bit, orthogonal experiment method was employed to design the hot pressing parameters of the same matrix formula. Samples were fabricated to test their bending strengths and microhardness, respectively. The effects of sintering temperature A, sintering pressure B, holding time C and cooling type D on the physical properties of diamond bit matrix were studied by variance analysis and range analysis. Results show that the influence on bending strengths of pure matrix and diamond matrix is A>D>B>C, and that the influence on hardness of matrix is A>C>B>D. The best mechanical properties of matrix is obtained under A₃B₃C₁D₄, which is at sintering temperature of 960 ℃, sintering pressure of 16 MPa, holding time of 3 min and cooling mode of 400 ℃ within furnace. At this time, the blending strength of the pure matrix was 983.33 MPa, and its hardness was 437.40 HV, while the blending strength of the diamond matrix was 525.00 MPa.

Enhancement of throwing power and covering power by applying composite additives in nickel sulfamate bath

ZHAO Yaomin, WU Xueling, FANG Xiangqian, WANG Kun, LI Yinghua

2020, 40(4): 41-46. doi: 10.13394/j.cnki.jgszz.2020.4.0006

Abstract(248)

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The performance of the nickel sulfamate bath is enhanced as a result of the composite additives. The results show that the dispersion capacity is increased from 21.43% to 58.29% and the covering power is increased from 40.0% to 53.5% with the additives of dibenzenesulfonimide (BBI) 0.45~0.60 g/L, sodium allylsulfonate (SAS) 1.30~1.50 g/L, propynesulfonic acid sodium salt (PS) 0.08~0.10 g/L, hydroxy propyl-2-mercapto-disultfonic acid sodium (SSO3) 0.02~0.03 g/L, 1-(3-sulfopropyl)pyridine inner salt (PPS-OH) 0.08~0.10 g/L. All these additives, namely BBI, SAS, PS, SSO3 and PPS-OH in a nickel sulfamate bath have contribution to different degrees to both the throwing power and the covering power, which is the synergistic effect of the combined additives.

Optimization of process parameters for high speed milling TC4 titanium alloy with PCD tool

WANG Sheng, LIU Wenjun, ZHOU Ming′an, ZHANG Yuxian, GU Yihong, YU Wenli

2020, 40(4): 47-52. doi: 10.13394/j.cnki.jgszz.2020.4.0007

Abstract(456)

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The TC4(Ti-6Al-4V)titanium alloy was plane milled precisely with PCD milling cutter. The flatness, the parallelism, the surface roughness, the surface hardness and the surface residual stress were measured by the coordinate measuring machine, the surface roughness meter, the micro Vickers hardness meter and the portable X-ray residual stress analyzer. The influences of different milling parameters on the quality and the surface morphology of TC4 titanium alloy were analyzed. The results show that with the optimal milling process parameters of spindle speed of 16 000 r/min, cutting depth of 0.2 mm and feed per tooth of 0.06 mm/z, the PCD milling cutter has a long life, and the TC4 titanium alloy workpiece has good surface quality and morphology. The flatness, the parallelism, the surface roughness, the microhardness and the residual stress of the workpiece are 0.26 μm, 0.64 μm, 0.63 μm, 3 080 N/mm² and -250 MPa, respectively.

Research on automatic draging-polishing of Shoushan stone

WANG Jian, LU Jing

2020, 40(4): 53-58. doi: 10.13394/j.cnki.jgszz.2020.4.0008

Abstract(209)

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Aiming at the problems of low efficiency and poor quality of Shoushan stone surface manual polishing, the parameters of the rock forming minerals, the microhardness, the mineral particle sizes and densities of five kinds of Shoushan stones were analyzed, and the different kinds of abrasives were selected to automatically polish them with dragging-polishing machine. The results show that the dragging-polishing technology can automatically polish Shoushan stone, and the surface quality of the polished Shoushan stone is good. For Shoushan stones with more quartz, higher hardness, and moderate mineral density, which polish with walnut shell and diamond, its surface roughness R_a are 293 nm and 335 nm. For Shoushan stone, which contains a lot of mica, is low in hardness, and has a low mineral density, polished with corncob and alumina, its surface roughness R_a is 521 nm.For Shoushan stones with pure rock-forming minerals, medium hardness and densest minerals, which are polished with corncob and diamond, its surface roughness R_a are 235 and 186 nm.

Investigation of grain wear in diamond abrasive belt grinding titanium alloy blade for aeroengine

LIANG Qiaoyun, SHAN Kun, LI Zhaorui, ZOU Lai, HUANG Yun

2020, 40(4): 59-64. doi: 10.13394/j.cnki.jgszz.2020.4.0009

Abstract(430)

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In precision abrasive belt grinding process of titanium alloy aeroengine blade, the wear of diamond belt has a great influence on machining accuracy and surface quality consistency. To solve this problem, the simulation of the grinding process of titanium alloy with single diamond grain was carried out on ABAQUS. On this basis, the grinding experiments of titanium alloy blade with diamond abrasive belt was carried out. The results of simulation and experiment show that the temperature of friction contact point is more than 700 K in the range of grinding speed of 10~20 m/s, and that the temperature increases with the increase of grinding speed. It is also found that the wear degree of abrasive belt increases with the increase of grinding speed, which is consistent with the effect of grinding speed on the grinding temperature of friction contact point. The wear forms of M10/20 diamond belt are grain wear and grain shedding, and the adhesion of abrasive debris aggravates the wear of belt.

Effect of back porosity on net abrasives for grinding car putty

ZHAI Jianchang, MENG Xia, FU Guihua

2020, 40(4): 65-69. doi: 10.13394/j.cnki.jgszz.2020.4.0010

Abstract(306)

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The number of holes in the net sand affects the effective grinding area, which affects the grinding performance of net sand. Polyester mesh cloth with different porosities was used as the backing of net sand, which was produced into net product after pre-treatment, the first layer resin, electrostatic coating, and the second layer resin. We study the influence of net backing cloth porosities in sanding car putty by observing clogging status during sanding, testing roughness of surface, and charaterizing the clogging condition of grid grinding surface through scanning electron microscope. The results show that for coarse grit sanding, the best porosity is 30%, and for the fine grit, the best porosity is 20%.

Experiment study on the 20CrMnTi ground surface performances

LIU Yao, LI Rui, ZHAO Yidong, XU Lijun, WU Chongjun

2020, 40(4): 70-75. doi: 10.13394/j.cnki.jgszz.2020.4.0011

Abstract(352)

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To explore the grinding parameters′ effect on 20CrMnTi ground surface quality, the grinding experiments by using CBN wheel were conducted. The characteristic of ground surface Rockwell hardness H, surface residential stress σ_s, and subsurface residential stress σ_ss were discussed to reveal the grinding ability of 20 CrMnTi by using the single factor experiment. The results indicate that under the same condition, the H decrease with the increase of wheel speed v_s and grinding depth a_p, and increase with the increase of wheel feed rate v_w. The a_p has the greatest influence, followed by the v_w and v_s. The ground surface is equipped with the compressive residential stress. The compressive stress (absolute value) shows the increase with the increase of v_w and decrease of a_p. As the v_s increase, the σ_s fluctuated. With the increase of subsurface depth, the σ_ss changes from compressive stress to tensile stress and finally becomes close to 0. The σ_ss distribution looks better in lower v_s and shallower a_p. By using v_s=60 m/s, v_w=1.045 m/s, a_p=3 μm, the higher H and surface residential compressive stress, and better σ_ss distribution can be obtained, which shows better ground surface quality.

Comparative study on machining of CFRP by end mill and abrasive router

ZHOU Jingwen, QIN Wenjin, MU Yingjuan, REN Peiqiang, LIU Xing, CHEN Yan

2020, 40(4): 76-80. doi: 10.13394/j.cnki.jgszz.2020.4.0012

Abstract(445)

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In order to study the influence of milling and grinding process on the machining quality of CFRP (carbon fiber reinforced plastics), the single-layer brazed diamond abrasive router and diamond coated end mill were used during the trimming experiment of T800 carbon fiber reinforced plastics. The difference of the machining quality and occurrence of defects were discussed according to the observation of micro topography and measurement of surface roughness. The results show that surface quality under abrasive machining process is much better than that of milling process. Great pits and resin smearing are observed after milling process, while the section of carbon fiber is visible under abrasive machining process. The discussion shows that the fracture of carbon fiber bundles contributes to the formation of great pits and the continual reaction between flank face and finished surface lead to the occurrence of resin smearing. Grinding is the preferred machining process under the strict requirements for surface quality and processing deficiency.

Research on polishing of front surface after welding of PCD tools

CHEN Qian, LI Man, ZHAO Min, WANG Fengqi

2020, 40(4): 81-86. doi: 10.13394/j.cnki.jgszz.2020.4.0013

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Three-factor four-level orthogonal experiments were first conducted to study the influence of technical parameters on surface roughness of PCD tools during the cloth-wheel polishing process which removes thermal damage layer of PCD tools.The test results show that the roughness changing value increases at first and then decreases with the increase of rotation speed; the roughness change value increases at first and then decreases, and increases again as compression amount increases; the roughness changing value increases at first and then decreases with polishing time extending. In the following, the influence degree of cloth-wheel speed, compression amount and polishing time on the changing value of the roughness is analyzed, and a ternary-quadratic prediction model of roughness changing value is established.The results show that the rotation speed of cloth wheel has the greatest influence on roughness changing value, followed by the compression amount, and the polishing time is the smallest; the correlation between the rotation speed, compression amount, polishing time and the roughness changing value is significant, and the model of roughness changing value fits well with experimental data.

Detection of subsurface microcracks after grinding of single crystal silicon wafer by polarized laser scattering

LI Qingpeng, BAI Qian, ZHANG Bi

2020, 40(4): 87-92. doi: 10.13394/j.cnki.jgszz.2020.4.0014

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In grinding process, there will inevitably produce subsurface microcrack damages on the monocrystalline silicon wafer. The subsurface microcrack damages of monocrystalline silicon wafer are nondestructively detected by the polarized laser scattering method, and the corresponding signal strength is obtained. The volume density of subsurface microcrack damages is quantitatively determined by using the destructive detection method, and the relationship between the detection signal strength and the volume density is established and verified by experiments. The results show that the relative error of the volume density of the subsurface microcracks obtained by the polarized laser scattering method is within 10% compared with the volume density obtained by the damage detection method. The polarized laser scattering method can detect the subsurface microcracks of silicon wafer nondestructively, accurately and quickly without affecting the production efficiency.

Effect of modified phenolic resin on performance of resin bond for super hard wheel

CHEN Chunhui, CHEN Zhe, LIU Yibo, HUANG Xia, BU Hongji, LIU Wei, KONG Shuaifei

2020, 40(4): 93-97. doi: 10.13394/j.cnki.jgszz.2020.4.0015

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Four different modified phenolic resins (PFs) for resin bonded superhard wheel were selected to explore the performance of resin bond. The different matrices were prepared using the modified resins. The decomposition temperature, the mechanical performance and the micro structure were analyzed with the comprehensive thermal analyzer, universal testing machine, Rockwell hardness tester and ultra depth filed microscope. The results show that the thermal decomposition temperatures of different modified PFs are 552, 527, 557 and 457 ℃. It is also found that the maximum Rockwell hardness comes from Resin 3031, namely 64, while the minimum hardness is from Resin 3034, namely 41, only 64% of that of 3031, and that Resin 3031 has the largest bending strength, 87 MPa, while Resin 3034 has the smallest bending strength, 50 MPa, 57.5% of that 3031.

2020 Vol. 40, No. 4

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