• Title/Summary/Keyword: material removal Rate

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Numerical Analysis of the Electro-discharge Machining Process of a Conductive Anisotropic Composite (전기전도성 이방성 복합재료 방전가공의 수치 해석)

  • Ahn, Young-Cheol;Chun, Kap-Jae
    • Korean Chemical Engineering Research
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    • v.47 no.1
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    • pp.72-78
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    • 2009
  • For the electro-discharge machining of an electro-conductive anisotropic composite, an unsteady state formulation was established and solved by Galerkin's finite element method. The distribution of temperature on work piece, the shape of the crater and the material removal rate were obtained in terms of the process parameters. The $12{\times}12$ irregular mesh that was chosen as the optimum in the previous analysis was used for computational accuracy and efficiency. A material having the physical properties of alumina/titanium carbide composite was selected and an electricity with power of 51.4 V and current of 7 A was applied, assuming the removal efficiency of 10 % and the thermal anisotropic factors of 2 and 3. As the spark was initiated the workpiece immediately started to melt and the heat affected zone was formed. The moving boundary of the crater was also identified with time. When the radial and axial conductivities were increased separately, the temperature distribution and the shape of the crater were shifted in the radial and axial directions, respectively. The material removal rate was found to be higher when the conductivity was increased in the radial direction rather than in the axial direction.

Optimization of CMP Process Parameter using Semi-empirical DOE (Design of Experiment) Technique (반경험적인 실험설계 기법을 이용한 CMP 공정 변수의 최적화)

  • 이경진;김상용;서용진
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.11
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    • pp.939-945
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    • 2002
  • The rise throughput and the stability in the device fabrication can be obtained by applying chemical mechanical polishing (CMP) process in 0.18 $\mu\textrm{m}$ semiconductor device. However, it still has various problems due to the CMP equipment. Especially, among the CMP components, process variables are very important parameters in determining the removal rate and non-uniformity. In this paper, we studied the DOE (design of experiment) method in order to get the optimized CMP equipment variables. Various process parameters, such as table and head speed, slurry flow rate and down force, have investigated in the viewpoint of removal rate and non-uniformity. Through the above DOE results, we could set-up the optimal CMP process parameters.

Effect of Particle Size of Ceria Coated Silica and Polishing Pressure on Chemical Mechanical Polishing of Oxide Film

  • Kim, Hwan-Chul;Lim, Hyung-Mi;Kim, Dae-Sung;Lee, Seung-Ho
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.4
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    • pp.167-172
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    • 2006
  • Submicron colloidal silica coated with ceria were prepared by mixing of silica and nano ceria particles and modified by hydrothermal reaction. The polishing efficiency of the ceria coated silica slurry was tested over oxide film on silicon wafer. By changing the polishing pressure in the range of $140{\sim}420g/cm^2$ with the ceria coated silica slurries in $100{\sim}300nm$, rates, WIWNU and friction force were measured. The removal rate was in the order of 200, 100, and 300 nm size silica coated with ceria. It was known that the smaller particle size gives the higher removal rate with higher contact area in Cu slurry. In the case of oxide film, the indentation volume as well as contact area gives effect on the removal rate depending on the size of abrasives. The indentation volume increase with the size of abrasive particles, which results to higher removal rate. The highest removal rate in 200 nm silica core coated with ceria is discussed as proper combination of indentation and contact area effect.

Development of Biofilter System for Ammonia Removal in Livestock Facility (축산 시설의 암모니아 가스 제거용 바이오 필터 시스템 개발)

  • 조성인;김명락;김유용;여운영
    • Journal of Biosystems Engineering
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    • v.28 no.5
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    • pp.457-464
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    • 2003
  • The purpose of this study was to develop a pilot scale bio-filter system removing ammonia gas with microorganisms. The system consisted of chaff(filter medium), a blower, a temperature sensor, a moisture sensor, a solenoid valve, and a heating system. Temperature and moisture contents were controlled via a PC to provide the microorganisms with proper environment. The microorganisms used in this study were Bacillius. coagulans NLRI T-6 and Pseudononas. putida NLRI S-21 of bacilli. Performance tests were performed to evaluate gas removal rate during 20 days. The result was shown that the removal rate was high in early days and gradually dropped below 90% without injecting the microbes. However, it was shown that when injecting the microbes, the removal rate was almost 100% and pH value was maintained at between 7 and 9 during the whole twenty-day period.

Development and Characterization of Ru CMP Slurry (Ru CMP Slurry의 개발 및 특성평가)

  • Kim, In-Kwon;Kwon, Tae-Young;Park, Jin-Goo;Park, Hyung-Soon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.57-58
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    • 2006
  • In MIM (metal insulator metal) capacitor, Ru (ruthenium) has been suggested as new bottom electrode due to its excellent electrical performance, a low leakage of current and compatibility to the high dielectric constant materials. In this case of Ru bottom electrode, CMP (chemical mechanical planarization) process was needed m order to planarize and isolate the bottom electrode. In this study, the effect of chemical A on polishing and etching behavior was investigated as functions of chemical A concentration, abrasive particle and pressure. Chemical A was used as oxidant and etchant. The thickness of passivation layer on the treated Ru surface increased with the increase of chemical A concentration. The etch rate and removal rate of Ru were increased by the addition of chemical A. The removal rate was highest m slurry of pH 9 with the addition of 0.1 M chemical A and 2 wt% alumina at 4 psi. The maximum removal rate is about 80 nm/min.

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Die Sinking Electrical Discharge Machining of SiC/AI Metal Matix Composite (탄화규소/알루미늄 금속계 복합재료의 형상방전가공)

  • 왕덕현
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.1
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    • pp.34-40
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    • 1998
  • Conductive metal matrix composite(MMC) material of 30% silicon carbide particulated based on aluminum matrix was machined by die sinking electrical discharge machining(EDM) process according to different current and duty factor for reverse polarity of electrode. Material removal rate(MRR) was examined by process under various operation conditions. The surface morphology was evaluated by surface roughness parameter and scanning electron microscopy(SEM) research. The MRR was suddenly increased over 11 ampere of current, and it was slightly changed over 0.3 of duty factor. The maximum surface roughness of EDMed surface was affected by the duty factor. The SEM photograghs of EDMed surface showed wide recast distribution region of melting materials as increased of current and duty factor.

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Simultaneous Optimization of Multiple Quality Characteristics in Laser Beam Cutting Using Taguchi Method

  • Dubey, Avanish Kumar;Yadava, Vinod
    • International Journal of Precision Engineering and Manufacturing
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    • v.8 no.4
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    • pp.10-15
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    • 2007
  • Taguchi methods have been used for a long time to improve the product quality and process performance of a manufacturing system, Few researchers have applied this methodology in laser beam cutting (LBC) of sheet metals and found the considerable improvement in cut qualities. In all experimental investigations of LBC so far, the objective was to optimize the single quality characteristic at a time. In this paper the simultaneous optimization of multiple quality characteristics such as Kerf width and material removal rate (MRR) during pulsed Nd:YAG LBC of thin sheet of magnetic material (high Silicon-steel) has been presented using Taguchi's quality loss function. The results show the considerable improvement in multiple S/N ratio as compared to initial cutting condition. Also, the comparison of results from single and multi-objective optimization have been presented and it was found that the loss in quality is always possible shifting from single quality to multiple quality optimization.

A Study on Machining Characteristic Comparison of Blanket Wafer(TEOS) by CMP and Spin Etching (CMP와 Spin Etching에 의한 Blanket Wafer(TEOS) 가공 특성 비교에 관한 연구)

  • 김도윤;정해도;이은상
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.1068-1071
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    • 2001
  • Recently, the minimum line width shows a tendancy to decrease and the multi-level to increase in semiconductor. Therefore, a planarization technique is needed, which chemical polishing(CMP) is considered as one of the most important process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as microscratches, abrasive contaminations, and non-uniformity of polished wafer edges. Spin Etching can improve the defects of CMP. It uses abrasive-free chemical solution instead of slurry. Wafer rotates and chemical solution is simultaneously dispensed on a whole surface of the wafer. Thereby chemical reaction is occurred on the surface of wafer, material is removed. On this study, TEOS film is removed by CMP and Spin Etching, the results are estimated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU).

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Effect of Sludge Pellets on $NO_x$ REmoval in $BaTiO_3$-sludge Packed-bed Reactor ($BaTiO_3$-슬러지 Packed-bed형 반응기에서 $NO_x$제거에 미치는 슬러지의 영향)

  • 박재윤;송원섭;고희석;박상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.10
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    • pp.861-867
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    • 2001
  • In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks on NO$_{x}$ removal, we measure NO removal characteristics with and without sludge pellets in BaTiO$_3$-sludge packed-bed reactor of plate-plate geometry. NO initial concentration is 50 ppm balanced with air and a gas flow rate is 5ι/min. Gas temperature is changed from 25 to 10$0^{\circ}C$ to investigate the role of sludge pellet on removing active oxygen species and NO$_2$. BaTiO$_3$pellets is filled for coronal discharge at upstream of reactor and sludge pellets is filled for catalytic effect at downstream of reactor. The volume percent of sludge pellets to BaTiO$_3$pellets is changed from 0% to 100% and AC voltage is supplied to the reactor for discharging simulated gases. In the results, when sludge pellets is put at the downstream of plasma reactor, NO removal rate is slightly increased. However, NO$_2$and $O_3$ as by-products during NO removal is significantly decreased from 51ppm without sludge pellets to 5 ppm with sludge pellets and from 50 ppm without sludge pellets to 0.004ppm with sludge pellets, respectively. Therefore, NO$_{x}$(NO+NO$_2$) removal rate is increased up to 93%. It is thought that sludge pellet maybe react with active oxygen species and NO$_2$ generated by corona discharge in surface of BaTiO$_3$pellets, the then NO$_2$O$_3$as by-products are considerably decreased. When we increase gas temperature from room temperature to 10$0^{\circ}C$, NO removal rate is decreased, while NO$_2$ concentration is independent on gas temperature. These result suggest that the removal mechanism of active oxygen species and NO$_2$in sludge pellet is not absorption, but chemical reaction. Therefore we expect that sludge pellets exhausted for waterworks could be used as catalyst for NO$_{x}$ removal with high removal rate and low by-product.oduct.

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The study on Fixed Bio-reactor Characteristics Using Porous Media (다공성 여재를 이용한 고정생물막 반응기 특성에 관한 연구)

  • 이영신;김동민;정상철;백명석
    • Journal of Environmental Health Sciences
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    • v.22 no.1
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    • pp.99-106
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    • 1996
  • The purpose of this study is to observe a specific removal efficiency of synthethetic wastewater which is managed by upflow submerged type at porous media which was sinteringed on a comparative low temperature 600$\circ$C, was annexed slag and humus soil with main material kaolinite. Observing removal efficiency quality of each media, a mixed media of kaolinite and humus soil by gravity percent 60, 40% respectively showed the most excellent removal utility, and applied predictive models for suspended culture kinetics without consideration diffusion limitation, and when analyzed kinetic which had been processed by this study the removal efficiency accompanied by carbon, nitrogen, phosphorous volumetric loading rate variation standed for a comparative large change rate 61~71%, it means the selection of the most proper load factor had a great effect on the highly removal efficiency, yield coefficient(Y) and specific microbial attach equation showed 1.53 mgVSS/mgCOD, $m_p=10039.4\times ((S_0)/(6.75+S_0))$ repectively.

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