• Title/Summary/Keyword: Electrical uniformity

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150 W LED Streetlight Optimal Design Using 21 W LED Engine (21 W LED 엔진을 이용한 150 W급 가로등의 최적설계)

  • Shin, Wang-Soo;Lee, Seung-Min;Kim, Beom-Su;Park, Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.1
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    • pp.62-67
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    • 2016
  • In this paper, the IES file was measured by applying a secondary optical lens to a 21 W LED engine, and the lighting calculation software RELUX was used to perform simulations with the data file of this measurement. For two-lane (two way) concrete paved roads, six LED engine are applied to each streetlight and simulation results show that Uo (uniformity) 0.56, UI (longitudinal uniformity) 0.86 and TI (threshold iIncrement) 9% which satisfies the required standards. RELUX was also used to LED streetlights by designing them in three dimensions, that is ${\pm}25%$ of the arm length of 2.8 m standardized by the road lighting standards of the Korea Expressway Corporation. Comparative analysis was carried out on adjustments were made in increments of 0.1 m that Uo, UI, and TI values in the range of arm lengths from 2.1 m~3.5 m. For the arm length range of 2.1 m~2.4 m, Uo was high, whereas UI was low. Therefore, we present the optimal light distribution values designed for an arm length of 2.5 m.

Analysis of n+ emitter properties using Dopant Pastes for Crystalline Silicon Solar Cells (결정질 실리콘 태양전지에 적용하기 위한 Dopant Pastes의 n+ emitter 특성 분석)

  • Lee, Ji-Hun;Cho, Kyeong-Yeon;Choi, Jun-Young;Lee, Soo-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.15-16
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    • 2007
  • The high efficiency and low cost solar cells in order to it applied a dopant pastes diffusion process. The dopant pastes diffusion process which it uses is easily applied in screen-printing solar cells output line. in this paper, it used the Ferro 99-038 phosphorus diffusion pastes source and it analyzed a sheet resistance and a uniformity degree. And it knew the quality of the sheet resistance which it follows in temperature and time condition. The temperature variable it let and it fixed the time in 7 minutes. It will be able to measure the sheet resistance of $40({\Omega}/sq),\;30({\Omega}/sq),\; 20({\Omega}/sq)$. also average uniformity of the sheet resistance was below 5%.

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A study on manufacture and evaluation of CMP pad controllable contact area (접촉 면적을 제어할 수 있는 CMP 패드 제작 방법 및 성능 평가에 관한 연구)

  • Choi, Jae-Young;Kim, Hyoung-Jae;Jeong, Young-Seok;Park, Jae-Hong;Kinoshita, Masaharu;Jeong, Hae-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.247-251
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    • 2004
  • Chemical-Mechanical Polishing(CMP) especially is becoming one of the most important ULSI processes for the 0.25m generation and beyond. And there are many elements affecting CMP performance such as slurry, pad, process parameters and pad conditioning. Among these elements the CMP pad is considered one of the most important because of its change. But the surface of the pad has irregular pores, so there is non-uniformity of slurry flow and of contact area between wafer and the pad, and glazing occurs on the surface of the pad. So we make CMP pad with micro structure using micro molding method. This paper introduces the basic concept and fabrication technique of CMP pad with micro-structure and the characteristic of polishing. Experimental results demonstrate the removal rate, uniformity, and time vs. removal rate.

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Formation of fine pitch solder bump with high uniformity by the tilted electrode ring (경사진 전극링을 이용한 고균일도의 미세 솔더범프 형성)

  • Ju, Chul-Won;Lee, Kyung-Ho;Min, Byoung-Gue;Kim, Seong-Il;Lee, Jong-Min;Kang, Young-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.323-327
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    • 2004
  • The bubble flow from the wafer surface during plating process was studied in this paper. The plating shape in the opening of photoresist becomes gradated shape in the fountain plating system, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. So, we designed the tilted electrode ring contact to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and ${\alpha}-step$. In ${\alpha}-step$ measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were ${\pm}16.6%,\;{\pm}4%$ respectively.

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Due to the Difference in Uniformity of Electrical Characteristics between Cells in a Battery Pack SOC Estimation Performance Comparative Analysis (배터리팩 내 셀 간 전기적 특성 균일도 차이에 의한 SOC 추정성능 비교분석)

  • Park, Jin-Hyeong;Lee, Pyeong-Yeon;Jang, Sung-Soo;Kim, Jonghoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.24 no.1
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    • pp.16-24
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    • 2019
  • The performance of the battery management system (BMS) algorithm is important for ensuring the stability and efficient operation of battery packs. Such a performance is determined by the internal parameters of the electrical equivalent circuit model (EECM). This study proposes a performance improvement and verification of battery parameters for the BMS algorithm using electrical experiments and tools. The parameters were extracted through electrical characteristic experiments, and an EECM based on Ah counting was designed. Simulation results using the EECM were compared with actual experimental data to determine the best parameter extraction method.

Investigations of Pd Based hybrid ohmic contacts to high-low doped n-type GaAs

  • Baik, Hong-Koo;Kwak, Joon-Seop
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1997.06a
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    • pp.231-236
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    • 1997
  • To improve electrical properties and uniformity of high-low doped n-type GaAs, new ohmic contacts with a low-resistance and the superior uniformity was developed using a concept of hybrid ohmic contact. The hybrid ohmic contact displayed good surface and interface morphology and had minimum contact resistivity of 3${\times}$10-6 $\Omega$$\textrm{cm}^2$ in a wide annealing temperature ranged from 340$^{\circ}C$ to 420$^{\circ}C$, which was much wider than that of conventional ohmic contacts. The microstructural analysis showed that the Pd/Ge ohmic contact at low annealing temperature (∼300$^{\circ}C$) and also annealing temperature (∼400$^{\circ}C$), resulting ij hybrid ohmic contacts.

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A Study on the Heat Transfer Characteristics and Performance of the High Temperature Range Heater Plate Using Liquid-Vapor Phase Change Heat Transfer (기-액 상변화 열전달식 고온 히터 플레이트의 작동 특성과 성능에 관한 연구)

  • Kang, Hwan-Kook;Yim, Kwang-Bin
    • Journal of Surface Science and Engineering
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    • v.46 no.6
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    • pp.283-289
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    • 2013
  • The experimental study for the temperature uniformity on the wafer using liquid-vapor phase heat transfer mechanism is performed. For the experiment, the heater plate which is consist of stainless steel container, working fluid and electrical heater is designed, manufactured and tested at the range of 600 to $850^{\circ}C$. The results showed that the phase change type heater plate was much more uniform and stable temperature on the heater plate surface and wafer than the uniform heat flux type heater plate at the atmospheric condition. Also, the results of 300 mm outer diameter of heater plate showed that the same temperature uniformity compared with 230 mm.

Magnetic Flux Density Distributions and Discharge Characteristics of a Newly Designed Magnetized Inductively Coupled Plasma

  • Cheong, Hee-Woon
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.360-365
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    • 2015
  • Spatial distributions of magnetic flux density in a newly designed magnetized inductively coupled plasma (M-ICP) etcher were investigated. Radial and axial magnetic flux densities as well as the magnetic flux density on the center of the substrate holder were controllable by placing multiple circular coils around the etcher properly. The plasma density non-uniformity in M-ICP (25 Gauss) can be reduced (1.4%) compared to that in ICP (16.7%) when the neutral gas pressure was 0.67 Pa and a right-hand circularly polarized wave (R-wave) can be propagated in to the etcher by making magnetic flux density increases both radially and axially from the center of the substrate holder.

Characteristics of Line-type Internal Inductively Coupled Plasma Source for Flexible Display Processing

  • Lim, Jong-Hyeuk;Kim, Kyong-Nam;Gweon, Gwang-Ho;Hong, Seung-Pyo;Yeom, Geun-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1490-1493
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    • 2009
  • In this work we present a new type of line plasma source using an internal-type ICP operated at 2MHz with a ferrite module, describe the effect of ferrite module on the enhancement of the plasma properties and the uniformity, and compare to those obtained with 13.56MHz discharge. Also the electrical characteristics of the antenna line and the characteristics of the plasma uniformity were studied.

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LED module for a desk lamp (탁상 스탠드용 LED모듈)

  • Kang, Seok-Hoon;Shin, Kyung-Ho;Yeo, In-Seon
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1713-1715
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    • 2003
  • This paper describes an LED module for a desk lamp using 1[W] high flux while LEDs. The optimum length of the module is obtained from the lighting simulation of the target area of $500{\times}500[mm]$ on the desk, which in turn determines an optimum separation between LEDs. The main issue is to find the optimum separation which gives good illuminance uniformity and high coefficient of utilization at at various reflector structures. Two module configuations of linear and ring types are compared. As a result, good illuminance uniformity is obtained in the case of the ring module. The mofied twin type, however, gives better performance than the ring module, and shows the most performance at an separation angle of around $30^{\circ}$.

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