• Title/Summary/Keyword: Plasma focus

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Development of Novel Electrode Materials for Plasma Display Panel

  • Kim, Chul-Hong;Chae, So-Ra;Lee, Min-Hee;Jeong, Hyun-Mi;Kim, Beom-Kwon;Heo, Eun-Gi;Choe, Deok-Hyeon;Lee, Byung-Hak
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1437-1440
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    • 2008
  • In this paper, we mainly deal with metallic electrode materials and patterning processing of plasma display panels. We focus on the recent development status, where low cost and high performance electrode materials such as Ag-based single-layered bus, low cost-in-use and anti-migration address electrodes are briefly introduced. The technological trends and further works on novel electrode materials and processing are also discussed.

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A study on the real time quality estimation in laser tailored blank welding (레이저 테일러드 브랭크 용접의 실시간 품질판단 및 통계프로그램에 관한 연구)

  • Park, Young-Whan;Rhee, Se-Hum;Park, Hyun-Sung
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.791-796
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    • 2001
  • Welding using lasers can be mass-produced in high speed. In the laser welding, performing real-time evaluation of the welding quality is very important in enhancing the efficiency of welding. In this study, the plasma and molten metal which are generated during laser welding were measured using the UV sensor and IR sensor. The results of laser welding were classified into five categories such as optimal heat input, little low heat input, low heat input, focus off, and nozzle change. Also, a system was formulated which uses the measured signals with a fuzzy pattern recognition method which is used to perform real-time evaluation of the welding quality and the defects which can occur in laser welding. Weld quality prediction program was developed using previous weld results and statistical program which could show the trend of weld quality and signal was developed.

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Development of laser tailored blank weld quality monitoring system (레이저 테일러드 블랭크 용접 품질 모니터링 시스템 개발)

  • 박현성;이세헌
    • Laser Solutions
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    • v.3 no.2
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    • pp.53-61
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    • 2000
  • On the laser weld production line, a slight alteration of the welding condition produces many defects. The defects are monitored in real time, in order to prevent continuous occurrence of defects, reduce the loss of material, and guarantee good quality. The measurement system is produced by using three photo-diodes for detection of the plasma and spatter signal in CO$_2$ laser welding. For high speed CO$_2$ laser welding, laser tailored welded blanks for example, on-line weld quality monitoring system was developed by using fuzzy multi-feature pattern recognition. Weld qualities were classified optimal heat input, a little low heat input, low heat input, and focus misalignment, and final weld quality were classified good and bad.

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Incidentally found unicentric plasma cell variant Castleman's disease in mesentery: focus on ultrasonography and CT findings (우연히 발견된 장간막의 단중심성 형질세포형 Castleman병 1예: 초음파와 CT 소견 중심으로)

  • Kim, Hyun Min;Kim, Bong Soo;Jung, In Ho;Hyun, Chang Lim;Jung, Seung Wook;Jo, Jae Min
    • Journal of Medicine and Life Science
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    • v.15 no.1
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    • pp.19-22
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    • 2018
  • Castleman's disease is a benign lympho-proliferative disorder that commonly occurs in mediastinum. It is known that the disease rarely occurs in mesentery. Most localized abdominal Castleman's diseases are histologically hyaline vascular type. The contrast-enhanced CT in patient with hyaline vascular type Castleman's disease shows a well-defined mass with homogenously intense enhancement. On the other hand, the patient with plasma cell variant has systemic symptoms, but not specific imaging features. We report a unicentric plasma cell variant Castleman's disease in mesentery nearby superior mesenteric artery as presenting a single mass, not accompanied by systemic symptoms with similar characteristics to hyaline vascular type.

Welding characteristics of Metal bellows using a Fiber laser (파이버 레이저를 이용한 밸로우즈 용접특성에 관한연구)

  • Kim, Jeng-O;Lee, Jae-Hoon;Lee, Seung-Woo
    • Laser Solutions
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    • v.16 no.3
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    • pp.22-26
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    • 2013
  • Fiber laser welding was performed on SUS Materials metal bellows. The results can be summarized as follows: When we tried to change welding focus location. we get the best welding line when focus location placed 0mm. In product welding, We could make a satisfactory product in constant area by applying optimized conditions and show a table that is able to help producer easily to apply it to manufacturing. In comparison with existing TIG and plasma welding, welded bellows by fiber laser has faster processing speed, smaller thermal effect, very narrow welding area and fine surface.

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Porous Bio-degradable Nano-fiber Machining by Femtosecond Laser (다공성 친바이오 나노섬유 극초단 레이저 가공특성 연구)

  • Choi, Hae-Woon
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.3
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    • pp.339-345
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    • 2012
  • Electrospun meshed poly-caprolactone PCL was patterned by femtosecond laser with linear grooves. As parametric variables, focus spot size, pulse energy, and scanning speed were varied to determine the affects on groove size and the characteristics of the electrospun fiber at the edges of these grooves. The femtosecond laser was seen to be an effective means for flexibly structuring the surface of ES PCL scaffolds and the width of the ablated grooves was well controlled by laser energy and focus spot size. The ablation threshold was measured to be $14.9J/cm^2$ which is a little higher than other polymers. These affects were attributed to optical multiple reflections inside nano-fibers. By the laser-induced plasma at higher pulse energies, some melting of fibers was observed.

The Analysis for PDP Discharge as a Parameter of Electrode Structure by 3-Dimensional Light Emission Measurement (3차원 광 측정을 통한 PDP의 전극 구조별 방전 분석)

  • Woo, Seok-Gyun;Choi, Hoon-Young;Lee, Seok-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.4
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    • pp.190-196
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    • 2001
  • We measured 3-dimensional images of the light emitted from plasma display panel(PDP) by using newly proposed scanned point detecting method(SPDM). The SPDM has the point detector with pinhole. The light emitted from PDP cell at the in-focus position can pass through the pinhole and be collected by detector. On the contrary, the light emitted from PDP cell at the out-of-focus positions is focused on the front of or the behind of the pinhole. We could analyze the characteristic of 3-dimensional light emission distribution by SPDM. From 3-dimensional measurement of 828[nm], the efficient design of PDP cell, the importance of opening ration, and the relations between BUS electrode position and discharge intensity are obtained. Also, the relationship between discharge characteristics and sustain electrode structures in AC-PDP are studied by measuring luminance, current, and discharge voltage.

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The 3-Dimensional Analysis for AC-PDP Discharge by Light Emission Measurement (AC-PDP의 3차원 광 측정을 통한 방전 분석)

  • 우석균;최훈영;이승걸;이석현
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.577-580
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    • 2000
  • We measured 3-dimensional images of the light emitted from plasma display panel(PDP) by using newly proposed scanned point detecting method(SPDM). The SPDM has the point detector with pinhole. The light emitted from PDP cell at the in-focus position can pass through the pinhole and be collected by detector. On the contrary, the light emitted from PDP cell at the out-of-focus positions is focused on the front of or the behind of the pinhole. We could analyze the characteristic of 3-dimensional light emission distribution by SPDM. From 3-dimensional measurement of 828nm, we found that the efficient design of PDP cell, the importance of opening ratio, and the relations between BUS electrode position and discharge intensity are obtained.

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Laser Weldability of Sheet steels for Tailored Blank Manufacturing(1) (테일러드 블랭크용 박판 강재의 레이저 용접성 (1))

  • 김기철
    • Journal of Welding and Joining
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    • v.16 no.1
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    • pp.77-87
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    • 1998
  • This paper deals with the effect of laser welding parameters on the weld formation. Thin steels for automotive application were prepared so as to be welded with high power carbon dioxide laser system. Major process parameters were position of focus and travel speed. The effect of shielding gas was also discussed by employing the high speed photometry. Test results showed that the optimal position of focus varied in accordance with the joint configuration; bead-on-plate, butt or lap welding. It was recommended that the position of focus for the lap welding be located at slightly inner part of the material to be welded. In this case, however, it was noticeable that the weld penetration ratio, d/t$_{0}$ dropped drastically at the critical region. Results also demonstrated that both the bead width and penetration reduced as the travel speed increased. The penetration ratio showed two distinct regions; stabilized zone at the lower range of the travel spped and sudden drop zone at the higher range of travel speed. Lower limit of the penetration for acceptable weld was proved to be about 90% of the parent metal thickness based on the physical properties of the weld. Mixed gas application for both the shielding of molten metal and laser induced plasma control was recommended as far as the penetration was concerned.d.

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Mechanism Study of Flowable Oxide Process for Sur-100nm Shallow Trench Isolation

  • Kim, Dae-Kyoung;Jang, Hae-Gyu;Lee, Hun;In, Ki-Chul;Choi, Doo-Hwan;Chae, Hee-Yeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.68-68
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    • 2011
  • As feature size is smaller, new technology are needed in semiconductor factory such as gap-fill technology for sub 100nm, development of ALD equipment for Cu barrier/seed, oxide trench etcher technology for 25 nm and beyond, development of high throughput Cu CMP equipment for 30nm and development of poly etcher for 25 nm and so on. We are focus on gap-fill technology for sub-30nm. There are many problems, which are leaning, over-hang, void, micro-pore, delaminate, thickness limitation, squeeze-in, squeeze-out and thinning phenomenon in sub-30 nm gap fill. New gap-fill processes, which are viscous oxide-SOD (spin on dielectric), O3-TEOS, NF3 Based HDP and Flowable oxide have been attempting to overcome these problems. Some groups investigated SOD process. Because gap-fill performance of SOD is best and process parameter is simple. Nevertheless these advantages, SOD processes have some problems. First, material cost is high. Second, density of SOD is too low. Therefore annealing and curing process certainly necessary to get hard density film. On the other hand, film density by Flowable oxide process is higher than film density by SOD process. Therefore, we are focus on Flowable oxide. In this work, dielectric film were deposited by PECVD with TSA(Trisilylamine - N(SiH3)3) and NH3. To get flow-ability, the effect of plasma treatment was investigated as function of O2 plasma power. QMS (quadruple mass spectrometry) and FTIR was used to analysis mechanism. Gap-filling performance and flow ability was confirmed by various patterns.

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