Proposing a New Evaluation Method in Si Wafer Rotary Grinding

2020 ◽  
Author(s):  
Jumpei Kusuyama ◽  
Bima Kawase ◽  
Yohichi Nakao ◽  
Masaki Kanazawa ◽  
Kazumasa Ishikawa
Keyword(s):  
Surface Roughness ◽  
Rotational Speed ◽  
Evaluation Method ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Dimensionless Number ◽  
Approach Angle ◽  
Grinding Conditions

Abstract Although there have been several studies on machining of semiconductor materials, most of them are concerned with abrasive finishing (such as chemical-mechanical polishing, mechanical polishing and lapping), and only a few have reported on optimizing rotary grinding conditions (such as the grinding wheel rotational speed, wafer rotational speed, wheel diameter, wafer diameter, and feed rate). In this study, to gain further insight, we define a dimensionless number and use it to evaluate our experimental results. This dimensionless number — called the “grain approach angle” — is the ratio of the grain running length of the machined wafer surface and the depth of cut due to grain during the grain running time. For this study, our evaluation coefficients are taken to be surface roughness, grinding force, and grinding ratio. We found it more suitable to use the grain approach angle rather than a previously defined dimensionless number (which was evaluated as the ratio of the wheel rotational speed to the wafer rotational speed). We also found that, by using the grain approach angle, trends in surface roughness exhibited invariant similarities under varying conditions.

scholarly journals Optimization of Wet Grinding Conditions of Sheets Made of Stainless Steel

2020 ◽  
Vol 4 (4) ◽  
pp. 114
Author(s):  
Akira Mizobuchi ◽  
Atsuyoshi Tashima
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Rotational Speed ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Steel Sheets ◽  
Wet Grinding ◽  
Grinding Fluid ◽  
Dry Grinding ◽  
Grinding Conditions

This study addresses the wet grinding of large stainless steel sheets, because it is difficult to subject them to dry grinding. Because stainless steel has a low thermal conductivity and a high coefficient of thermal expansion, it easily causes grinding burn and thermal deformation while dry grinding on the wheel without applying a cooling effect. Therefore, wet grinding is a better alternative. In this study, we made several types of grinding wheels, performed the wet grinding of stainless steel sheets, and identified the wheels most suitable for the process. As such, this study developed a special accessory that could be attached to a wet grinding workpiece. The attachment can maintain constant pressure, rotational speed, and supply grinding fluid during work. A set of experiments was conducted to see how some grinding wheels subjected to some grinding conditions affected the surface roughness of a workpiece made of a stainless steel sheet (SUS 304, according to Japanese Industrial Standards: JIS). It was found that the roughness of the sheet could be minimized when a polyvinyl alcohol (PVA) grinding wheel was used as the grinding wheel and tap water was used as the grinding fluid at an attachment pressure of 0.2 MPa and a rotational speed of 150 rpm. It was shown that a surface roughness of up to 0.3 μm in terms of the arithmetic average height could be achieved if the above conditions were satisfied during wet grinding. The final surface roughness was 0.03 μm after finish polishing by buffing. Since the wet grinding of steel has yet to be studied in detail, this article will serve as a valuable reference.

scholarly journals Correlation between surface roughness and AE signals in ceramic grinding based on spectral analysis

2018 ◽  
Vol 249 ◽  
pp. 03003 ◽  
Author(s):  
M A Aulestia Viera ◽  
F A Alexandre ◽  
P R Aguiar ◽  
R B Silva ◽  
E C Bianchi
Keyword(s):  
Surface Roughness ◽  
Frequency Domain ◽  
Surface Condition ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Process Conditions ◽  
Workpiece Surface ◽  
Grinding Conditions ◽  
Grinding Machine ◽  
Frequency Domain Techniques

The study and monitoring of the workpiece surface roughness is one of the most important parameters of the grinding process. This paper proposes a method for analysing the surface condition of ground ceramic components by means of the acoustic emission (AE) signal analysis along with frequency domain techniques. Tests were performed using a surface-grinding machine equipped with a resin-bond diamond grinding wheel, where signals were collected at 2 MHz. Alumina workpieces were machined under six different depth of cut values, covering slight, medium and severe grinding conditions. Frequency content was studied in order to select bands closely related to the process conditions. An analysis of the root mean square values (RMS) of the signals was performed, seeking for a correlation with the surface roughness. Digital filters were applied to the raw signals. The RMS values filtered for two frequency bands presented a better fitting to the linear regression, which is highly desirable for setting a threshold to detect the workpiece surface conditions and implementing into a monitoring system. Results showed that the amplitude of the signals presented different characteristics in the frequency domain according to the workpiece surface condition. It was also observed a higher spectral activity in the severe grinding conditions.

Optimization of Surface Roughness in Centreless Grinding Process Based on Taguchi Method

2021 ◽  
pp. 37-47
Author(s):  
Prosun Mandal
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Wheel Speed ◽  
Depth Of Cut ◽  
Grinding Process ◽  
Signal To Noise ◽  
Grinding Parameters ◽  
Medium Level ◽  
Grinding Conditions ◽  
Valve Opening

This chapter aims to optimize centreless grinding conditions using the Taguchi method for minimizing surface roughness. The grinding operation has been performed according to the L9 orthogonal array in a centreless grinding process. The centreless grinding experiments are carried out on the crane-hook pin of C40 steel. The analysis of variance (ANOVA) and computation of signal to noise (S/N) ratio are adopted to determine the influence of grinding parameters (depth of cut [µm], regulating wheel speed [rpm], and coolant valve opening) on surface roughness. The depth of cut (µm) is found to be the most significant among the grinding parameters on the surface roughness. The signal to noise (S/N) ratio was calculated based on smaller the best criteria. The lower level of depth of cut, medium level of regulating wheel speed, and higher-level coolant valve opening is found to be optimal grinding condition according to the mean response and signal to noise (S/N) ratio.

Development of TSV Reveal Process Using Very Fine Si/Cu Grinding and Metal Contamination Removal

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 001928-001955
Author(s):  
Naoya Watanabe ◽  
Masahiro Aoyagi ◽  
Daisuke Katagawa ◽  
Tsubasa Bandoh ◽  
Takahiko Mitsui ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Chemical Mechanical Polishing ◽  
Metal Contamination ◽  
Mechanical Polishing ◽  
Grinding Wheel ◽  
Average Surface Roughness ◽  
Average Surface ◽  
3D Ics ◽  
Cu Contamination ◽  
Contamination Removal

Three-dimensional integrated circuits (3D-ICs) using through silicon via (TSV) have been developed as an emerging technology that can lead to significant progress (1–4). Among various TSV processes, the via-middle process has potential for wide spread use because formation of small-sized TSVs is relatively easy in the via-middle process. However, TSV reveal process must be performed for electrical contact in the via-middle process. This TSV reveal process is important because it can influence the metal contamination and stacking yield of 3D-ICs. Conventionally, TSV reveal is performed by Si grinding and Si dry etching (5). A disadvantage of that method is the resultant TSV depth deviation, which can cause bonding failure during wafer/chip stacking. In (6), TSV leveling was performed by introducing a chemical mechanical polishing (CMP) step after deposition of the backside insulator. However, the revealed TSVs break during CMP step if they exceed a certain height. To overcome these problems, we developed a novel TSV reveal process comprising direct Si/Cu grinding and metal contamination removal (7,8). First, simultaneous grinding of Cu and Si was performed using a novel vitrified grinding wheel. In situ cleaning with a high-pressure micro jet and the inelastic porous structure of the grinding wheel suppressed the adhesion of Cu contaminants to the Si, and TSVs were leveled and exposed. Next, an electroless Ni-B film was deposited on the Cu surface of the TSVs. The Si was etched with an alkaline solution, whereas the Cu was protected by the Ni-B film. An insulator was deposited, and then the insulator on the top surface of the TSV was removed. We achieved the backside reveal of TSVs without TSV depth deviation and suppressed Cu contamination to less than 1e11 atoms/cm2. However, after direct Si/Cu grinding with an 8000 grit grinding wheel, the average surface roughness of Si was 5–10 nm, which is larger than that after chemical mechanical polishing (CMP). In this paper, we developed vitrified grinding wheels with very high grit numbers (#30,000 and #45,000) and present an improved version of our TSV reveal process. The average surface roughness of Si after Si/Cu grinding was approximately 3 nm for the 30,000 grit grinding wheel and 1 nm for the 45,000 grit grinding wheel. This value is equivalent to that after CMP. The improved process produced a uniform reveal of 4-um-diameter TSVs without TSV depth deviation and Cu contamination. The Cu contaminant concentration on Si region between TSVs was small (<3e10 atoms/cm2). This process will reduce the cost of the TSV reveal process and considerably improve the TSV yield.

Effects of Relative Velocity on Grinding Performances under Si Wafer Rotary Grinding

2016 ◽  
Vol 874 ◽  
pp. 395-400
Author(s):  
Jumpei Kusuyama ◽  
Takayuki Kitajima ◽  
Akinori Yui ◽  
Toshihiro Ito
Keyword(s):  
Surface Roughness ◽  
Power Consumption ◽  
Relative Velocity ◽  
Velocity Ratio ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wafer Thickness ◽  
Grinding Conditions ◽  
The Difference ◽  
Si Wafer

For the backgrinding of semiconductor devices, a rotary grinding process is indispensable for achieving the required wafer thickness. The relative velocity between the grinding wheel and the wafer is maximum at the periphery of the wafer and minimum at the center of wafer. Generally, the grinding performances are discussed in terms of the ratio of the rotational speeds of the grinding wheel and the wafer. However, it is not possible to use this ratio to determine the grinding conditions for different wafer sizes grinding as this ratio does not show the difference in relative velocity. Therefore, a new relative velocity ratio was defined in this study. Then, the Si wafer grinding was performed to investigate the effect of the surface roughness and the power consumption of the grinding wheel spindle on the relative velocity ratio.

scholarly journals Effect of Cutting Depth and Feed Speed to Surface Roughness in Lathe Process of Screw Conveyor Shaft (Case Study: PT. RAPP)

2020 ◽  
Vol 64 (2) ◽  
pp. 59-62
Author(s):  
Junaidi Abdul Khair ◽  
◽  
Deni Pranata ◽  
Ujang Nurhadek ◽  
◽  
...  
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Rotational Speed ◽  
High Speed ◽  
Feeding Rate ◽  
Production Quality ◽  
Screw Conveyor ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Turning Process

The metalworking process is one of the most important things in manufacturing of machine components, such as lathe process. Therefore, it is required continuously innovation to improve production quality. There are several ways to do this, for example by choosing the right type of tool, depth of cut, and spindle speed. In turning process for the production of goods is very important to produce a precision product in accordance to desiring of size and roughness. The turning speed of a lathe has a type of spindle rotation rate that is used according to production requirements, which uses a rotational speed that can be changed the rate of rotation of the machine, in order to determine the level of surface roughness in the turning process. One is affected the optimal conditions of the turning speed and feeding rate. In this paper, the variations of different rotational speed levels of low speed, medium speed and high speed according to variations of feeding rate in order to know the difference in roughness results for the screw conveyor shaft operation. The roughness was measured on the surface turning process using a reference of surface roughness stand comparator (ISO2632 / I-1975). The result of test revealed the greater speed of feed rate, the greater value of roughness. Reversely, the smaller speed of feed rate affected the lower roughness value.

scholarly journals Surface Quality Evaluation of Various Metals After Grinding with Aluminum Oxide Grinding Wheel

2020 ◽  
Vol 9 (1) ◽  
pp. 25-31
Author(s):  
Rosemar Batista Da Silva ◽  
Giordano Francis Vieira ◽  
Letícia Cristina Silva ◽  
Carlos Alberto Damião ◽  
Rodrigo De Souza Ruzzi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Cast Iron ◽  
Aluminum Oxide ◽  
Surface Quality ◽  
Gray Cast Iron ◽  
Gray Cast ◽  
Surface Finishing ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Machined Surfaces

Different metals can respond differently when grinding using the same abrasive grinding wheel, especially in terms of surface quality. In this context, this work aims give a contribution to the metalworking industry by presenting the results of surface finishing after grinding the following metals: VP Atlas steel grade, Gray Cast Iron and two superalloys, Inconel 718 and Ti-6Al-4V. Tests were performed with the aluminum oxide grinding wheel and with following parameters: cutting speed of 37.6 m/s and workspeed of 10 m/min. Two values of depth of cut (15 μm and 30 μm) were tested. The surface roughness (Ra and Rz parameters) were analyzed and SEM images of the machined surfaces were taken and analyzed in order to identify the cutting mechanisms and provide better results discussion. The results showed that the surface roughness increased with the depth of cut; Ra values kept below 0.48 μm for all metals tested. Regarding the machined surface quality, some cracks were observed on the gray cast iron and Ti-6Al-4V surfaces, thereby indicating their relative lower grindability compared to VP Atlas steel under the investigated conditions. No visual thermal damage was observed in the machined surfaces of the samples.

scholarly journals Research on selection of abrasive grain size and cutting parameters when grinding of interrupted surface using aluminum oxide grinding wheel with ceramic binder

2022 ◽  
pp. 93-102
Author(s):  
Do Duc Trung ◽  
Le Dang Ha
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Aluminum Oxide ◽  
Feed Rate ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Testing Sample ◽  
Abrasive Grain ◽  
Ceramic Binder

In this article, a study on intermittent surface grinding using aluminum oxide grinding wheel with ceramic binder is presented. The testing material is 20XH3A steel (GOST standard – Russian Federation). The testing sample has been sawn 6 grooves, with the width of each groove of 10 mm, the grooves are evenly distributed on the circumference of sample. The testing sample resembles a splined shaft. An experimental matrix of nine experiments has been built by Taguchi method, in which abrasive grain size, workpiece speed, feed rate and depth of cut were selected as input variables. At each experiment, surface roughness (Ra) and roundness error (RE) have been measured. Experimental results show that the aluminum oxide and ceramic binder grinding wheels are perfectly suitable for grinding intermittent surface of 20XH3A steel. Data Envelopment Analysis based Ranking (DEAR) method has been used to solve the multi-objective optimization problem. The results also showed that in order to simultaneously ensure minimum surface roughness and RE, abrasive grain size is 80 mesh, workpiece speed is 910 rpm, feed rate is 0.05 mm/rev and depth of cut is 0.01 mm. If evaluating the grinding process through two criteria including surface roughness and RE, depth of cut is the parameter having the greatest effect on the grinding process, followed by the influence of feed rate, workpiece speed, and abrasive grain is the parameter having the least effect on the grinding process. In addition, the effect of each input parameter on each output parameter has also been analyzed, and orientations for further works have also been recommended in this article

Precision Grinding of SUS304 Using Metal Bonded CBN Wheel

2007 ◽  
Vol 24-25 ◽  
pp. 261-264 ◽  
Author(s):  
Y. Hasuda ◽  
Y. Suzuki ◽  
Y. Tadokoro ◽  
S. Kinebuchi ◽  
T. Ohashi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Precision Grinding ◽  
Wear Process ◽  
Cbn Wheel ◽  
Grinding Conditions ◽  
Wear Of Grinding Wheel ◽  
Stock Removal ◽  
Fundamental Experiment

The fundamental experiment of the grinding of the stainless steel using the metal bonded CBN wheel which was excellent in wear resistance was conducted. The most appropriate grinding conditions were obtained by clarifying wear process of grinding wheel and finished ground surface quality. When grinding was carried out up to stock removal 7000mm3/mm, radial wear of grinding wheel %R is 3μm and surface roughness Rz was 0.5μm or less. The grinding ratio Gr becomes about 3000, and long life grinding with little change of surface roughness was possible.

Analysis on the Effects of Cutting Parameters on Surface Roughness of Workpiece in Surface Grinding

2019 ◽  
pp. 277-282
Author(s):  
Nguyen Hong Son ◽  
Do Duc Trung
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Surface Grinding ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Test Results ◽  
Value Range ◽  
Cbn Grinding Wheel ◽  
Design Experiments

In this paper, the analysis on the effects of cutting parameters on surface roughness of workpieces in surface grinding has been conducted. Experimental SUJ2 steel grinding process is made with CBN grinding wheel. The tests is made on an APSG-820/2A surface grinder. The Box- Behnken method has been used to design experiments. Minitab 16 statistical software has been used to analyze ANOVA test results. The results show that the feed-rate has the greatest effect on surface roughness, followed by the least effects of velocity of workpiece, depth of cut on surface roughness. The interaction between velocity of workpiece and depth of cut has the greatest effect on surface roughness, followed by the effects of the interaction between the feed-rate and depth of cut, the interaction between velocity of workpiece and the feed-rate has insignificant effects on surface roughness. This study also shows the value range of some cutting parameters for processing surface of workpiece with small roughness. Finally, a regression model of surface roughness has been established in this study.

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