• Title/Summary/Keyword: thermal process

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A Study on the Precision Milling Machine Design for Micro Machining (미소가공을 위한 초정밀 밀링머신 설계에 관한 연구)

  • Hwang, Joon;Ji, Kwon-Gu;Chung, Eui-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.1
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    • pp.48-56
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    • 2009
  • This paper presents the results of miniaturized micro milling machine tool development for micro precision machining process. Finite element analysis has been performed to know the relationship between design dimensional variables and structural stiffness in terms of static, dynamic, thermal aspects. Design optimization has been performed to optimize the design variables of micro machine tool to minimize the volume, weight and deformation of machine tool structure and to maximize the stiffness in terms of static, dynamic, and thermal characteristics. This study presents the assessment of the technology incentive for the minimization of machine tool in the quantitative context of static, dynamic stiffness, thermal resistance and thus the accuracy implications. This study can also be provided a basic knowledge for further research of micro factory development.

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Wear Behavior of Al/SiC in Thermal Spray Process (알루미늄 판 표면에 용사된 Al/SiC의 마모 거동)

  • Kim, H.J.;You, M.H.;Lee, S.H.;Lee, K.J.
    • Journal of Power System Engineering
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    • v.10 no.2
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    • pp.111-116
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    • 2006
  • Tribologcal property of the ceramics used in severe condition was investigated and both $Al_2O_3$ ball and Al/SiC composite made by thermal spray process[TSP] were used as a specimen in this study. Four kinds of material couple in ball and disk specimens were tested in the dry condition by using ball-on-disk type tribo-tester. Friction coefficient, surface roughness, wear rate, and photograph of the worn surface were investigated. Generally, High SiC contents[$40{\sim}50%$] specimens showed very low friction coefficient below 0.05 and little wear rate in dry condition. And also, low SiC contents[0%] specimens showed a moderate wear rate and high coefficient of friction at the same condition.

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Analyses Thermal Stresses for Microaccelerometer Sensors using SOI Wafer(I) (SOI웨이퍼를 이용한 마이크로가속도계 센서의 열응력해석(I))

  • Kim, O.S.
    • Journal of Power System Engineering
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    • v.5 no.2
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    • pp.36-42
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    • 2001
  • This paper deals with finite element analyses of residual stresses causing popping up which are induced in micromachining processes of a microaccelerometer sensors. The paddle of the micro accelerometer sensor is designed symmetric with respect to the direction of the beam. After heating the tunnel gap up to 100 degree and get it through the cooling process and the additional beam up to 80 degree and get it through the cooling process. We learn the thermal internal stresses of each shape and compare the results with each other, after heating the tunnel gap up to 400 degree during the Pt deposition process. Finally we find the optimal shape which is able to minimize the internal stresses of microaccelerometer sensor. We want to seek after the real cause of this pop up phenomenon and diminish this by change manufacturing processes of microaccelerometer sensor by electrostatic force.

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A study on the thermal analysis of resistance sport welding Process using a FEM method (FEM 방법을 이용한 저항 점용접 공정의 열분석에 관한 연구)

  • Kim, Ill-Soo;Hou Zhigang;Wang Yuanxun;Li Chunzhi;Chen Chuanyao
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.172-174
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    • 2003
  • In this paper, a 2D axisymmetric model of thermoelectric Finite Element Method (FEM) is developed to analyze the transient thermal behavior of Resistance Spot Welding (RSW) process using commercial software, called ANSYS. The determination of the contact resistance at the faying surface is moderately simplified to reduce the calculating time, while the temperature dependent material properties, phase change and convectional boundary conditions are taken account fur the improvement of the calculated accuracy. The thermal history of the whole process (including cooling) and temperature distributions for any position in the weldment is obtained through the analysis.

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A study on rapid tooling technology using thermal spray process (아크 용사를 이용한 쾌속 금형 제조 기술)

  • Kim, Kyung-Hwa;Kim, Sun-Kyung;Yu, Young-Eun;Jea, Tae-Jin;Choi, Doo-Sun
    • Design & Manufacturing
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    • v.2 no.2
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    • pp.20-24
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    • 2008
  • Recently, the study for production technology is focused on cycle time reduction as various products are manufactured. In order to manufacture tool and die, rapid prototyping and rapid tooling are researched. Stereolithography apparatus, selective laser sintering, 3D printing, laminated object manufacturing are developed in rapid prototype. The purpose of this study is to develop rapid tooling technology using thermal spray process. This technology is not well-known to korea, but this study will be contributed in development of domestic molds industry through continuous research and development.

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Field Enhanced Rapid Thermal Process for Low Temperature Poly-Si TFTs Fabrications

  • Kim, Hyoung-June;Shin, Dong-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.665-667
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    • 2005
  • VIATRON TECHNOLOGIES has developed FE-RTP system that enables LTPS LCD and AMOLED manufacturers to produce poly-Si films at low cost, high throughput, and high yield. The system employs sequential heat treatment methods using temperature control and rapid thermal processor modules. The temperature control modules provide exceptionally uniform heating and cooling of the glass substrates to within ${\pm}2^a\;C$. The rapid thermal process that combines heating with field induction accelerates the treatment rates. The new FE-RTP system can process $730{\times}920mm$ glass substrates as thin as 0.4 mm. The uniform nature of poly-Si films produced by FE-RTP resulted in AMOLED panels with no laser-Muras. Furthermore, FE-RTP system also showed superior performances in other heat treatment processes involved in poly-Si TFT fabrications, such as dopant activation, gate oxide densification, hydrogenation, and pre-compaction.

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Co-firing Optimization of Crystalline Silicon Solar Cell Using Rapid Thermal Process (급속 열처리 공정을 이용한 결정질 실리콘 태양전지의 전극 소결 최적화)

  • Oh, Byoung-Jin;Yeo, In-Hwan;Lim, Dong-Gun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.3
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    • pp.236-240
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    • 2012
  • Limiting thermal exposure time using rapid thermal processing(RTP) has emerged as promising simplified process for manufacturing of solar cell in a continuous way. This paper reports the simplification of co-firing using RTP. Actual temperature profile for co-firing after screen printing is a key issue for high-quality metal-semiconductor contact. The plateau time during the firing process were varied at $450^{\circ}C$ for 10~16 sec. Glass frit in Ag paste etch anti-reflection layer with plateau time. Glass frit in Ag paste is important for the Ag/Si contact formation and performances of crystalline Si solar cell. We achieved 17.14% efficiency with optimum conditions.

Effects of the Rapid Thermal Annealing on the Electrical and Structural Properties of Polysilicon Films (급속 열처리 공정에 의한 다결정 실리콘 박막의 전기적, 구조적 특성 연구)

  • 김윤태;유형준;전치훈;장원익;김상호
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.9
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    • pp.1060-1067
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    • 1988
  • In this paper, we have investigated the effects of rapid thermal process on the electrical and structural properties of silicon films. It was shown that required times and temperature for the successful activation of dopants (Boron, Phosphorus:5E15atoms/cm\ulcorner were above 1000\ulcorner, 10sec, respectively. The typical resistivities of films deposited below 600\ulcorner were in the range of 1.0 E-3ohm-cm which was 20-30% lower than that of initially polycrystalline silicon depositd above 600\ulcorner. After rapid thermal process at high temperature above 1000\ulcorner, the films did not reveal any change in resistivity due to the dopant segregation, and better electrical conductivity could be obtained by increasing the process time. The grain growth by RTA treatment was more salient in the case of the doped amorphous than that of initially polycrystalline. The surface of the films also preserved the higher structural perfection and surface smoothness.

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A Study on Thermal Stratification Characteristics and Useful Rate of Hot Water in Thermal Storage Tank during Hot Water Extraction Process (온수 추출과정 동안 축열조 내의 열성층 특성 및 온수 이용률에 관한 연구)

  • 장영근;박정원
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.6
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    • pp.503-511
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    • 2002
  • Heat flow characteristics during hot water extraction process was studied experimentally. Data were taken at various outlet port type for the fixed inlet port type, inlet-outlet temperature differences and mass flow rates. In this study, the temperature distribution in a storage tank and an outlet temperature were measured to predict a degree of stratification in the storage tank, and a useful rate of hot water was analysed with respect to the variables dominating a extraction process. Experimental results show that the degree of stratification and useful rate of hot water are all high in a low flow rate in case of using modified distributor I (MDI) as the outlet port type.

Wear Analysis of Hot Forging Die considering Thermal Softening (열연화 현상을 고려한 열간 단조 금형의 마멸해석)

  • 이진호;김동진;김병민;김호관
    • Transactions of Materials Processing
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    • v.9 no.1
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    • pp.43-51
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    • 2000
  • The die wear is one of the main factors affecting product accuracy and die life in hot forging process. It is desired to analyze die wear by developing wear prediction method combined with FE-simulatin and experiment. Lots of researches have been done into the wear analysis of cold forging die, and the results of those researches were successful, but there have been little applications to hot forging die giving successful results. That is because hot forging process has many factors influencing die wear, and there was not accurate in-process data. In this research, change of die surface hardness by thermal softening during the lifetime was obtained by experiment, and hardness distribution of cross section was measured. This wear analysis was applied to hot forging die, and gave comparatively good results compared with actual wear profile.

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