• 한국전기전자재료학회논문지
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• 제26권6호
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• pp.493-501
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• 2013

LED lighting is sensitive because it made by semiconductor. So it has been researched about radiation of heat technologies for a long time. In addition, measurement and assessment a radiation of heat also conducted. It is necessary to get a date of accuracy temperature on the board after LED driven for measuring Junction temperature of the LED Lighting. For this research, we use 5 chip which is 4 W power on top of LED lighting board made by aluminum. Thermal camera effects to emissivity depending on material and property of the surface in LED board because it determines thermal energy which emitted from material surface. it is not only thermal camera has not a standard about emissivity. It has an error of temperature when emissivity was measured by thermal camera. we confirmed that emissivity and reflected temperature depending on color and quality of the surface throughout experiment.

• 조명전기설비학회논문지
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• 제28권10호
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• pp.1-8
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• 2014

Heat dissipation of the high power LED is a critical issue. To estimate the junction temperature of the LED chip is most important in characterizing the heat dissipation, but it is impossible to directly measure it. In this study, surface temperatures of the 12.8W LED bulb was measured for 5 points using a data logger and compared with the simulated results using a thermal simulator based on FVM (finite volume method) to secure a reliability of the simulation. Effects of some factors such as lens, emissivity and air inlet were investigated using simulation works and then the results were analysed.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.73-78
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• 2008

A resistor network model for the horizontal AlInGaN LED was investigated, The parameters of the proposed model are extracted from the test dies and $350{\mu}m$ LED, The center of the P-area is the optimal position of a P-electrode by the simulation using the model. Also the optimal chip size of the LED for the new target current was investigated, Comparing the simulation and fabrication result, the errors for the forward voltage and the light power are average 0,02 V, 8 % respectively, So the proposed resistor network model with the linear forward voltage approximation and the exponential light power model are useful in the simulation for the horizontal AlInGaN LED.

• 한국정보시스템학회지:정보시스템연구
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• 제20권3호
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• pp.111-127
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• 2011

This study is intended for international cooperation in the field of LED were analyzed. The results, LED wide coverage areas, and a promising future is expected to grow fast enough to occupancy for a major national technology is a competitive situation. Chip Scale Package, including our country, such as LED manufacturing technology that might be competitive in parts, but new technologies such as renal substrate R&D and technology development still active preemption is not the situation. Renal substrate, particularly, large-diameter sapphire, large size/large LED manufacturers, such as a promising area for future research and development support will be needed. To do this, previous research in this area and the U.S., Japan cooperation in such studies also will need to expand. Bibliometrics way through this study, analytical techniques and analytical tools used in the integrated analysis of the usefulness and necessity of the system development were found.

• 한국전기전자재료학회논문지
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• 제23권1호
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• pp.38-41
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• 2010

Compared to conventional molding technology, the color uniformity of light direction emitted from LED is improved with PCB type lead frame technology in which metal thin film is used and transfer molding technology which makes the density of phosphor uniform by manufacturing high density LED lamp. The light efficiency and the color uniformity of the LED are improved by molding the phosphor layer outside of chip and controlling the thickness of the phosphor layer. CIE x,y difference of LED in major axis is also improved uniformly from 0 to 90 degrees.

• 한국광학회지
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• 제20권4호
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• pp.236-240
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• 2009

LED 조명과 액정 후면 배광 장치와 같이 고방열, 고출력 광원이 요구되는 응용제품에 적합한 LED 광원 모듈을 제작하였다. 제안한 LED 광원 모듈은 기존 패키지 구조의 LED 광원과 다르게 LED 칩을 응용제품의 필요에 따른 배광 분포 제어와 광자재흡수를 개선하기 위해 반사컵 구조를 적용한 금속 기판의 표면에 LED 칩을 바로 실장하였다. 또한 기존 금속기판에 적용하던 알루미늄 산화막 절연층의 문제점을 개선하여 방열 특성을 향상시켰다. 나아가 방열 특성 개선으로 LED 칩에서 발생하던 열에 의해 발생하던 광효율 저하 문제를 개선하는 결과를 얻었다.

• 한국통신학회논문지
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• 제37권7B호
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• pp.606-612
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• 2012

가시광 통신은 반도체 LED를 이용하여 정보를 브로드캐스트 하며, 백색광 LED는 조명과 광무선 통신을 하나의 광원을 사용하여 제공할 수 있다. 본 논문에서는 단일칩 백색광 LED를 활용하여 조명과 통신에 적합한 조명기구를 제안한다. 백생광 LED 조명기구의 구조에 따른 수평 조도특성, 무선채널 대역특성, 심볼간 간섭현상, 신호대 잡음비 및 비트 에러율을 분석함으로써 장애물이 있는 경우 제안한 LED 조명이 기존의 조명보다 우수한 조명 및 통신 채널을 제공함을 보이고자 한다.

• 조명전기설비학회논문지
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• 제28권7호
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• pp.1-12
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• 2014

This paper is proposed to design the new heat-sink apparatus for improving the heat transfer characteristics in the power LED chip, and results of the operation characteristics were discussed. The core design is that the soldering through-hole on the FR-4 PCB board is formed to the effective heat transfer. That is directly filled with Ag-nano materials, which shows the high thermal conductivity. The heat transfer medium consisting of Ag-nano materials is classified into two structures. Mediums are called as the heat slug and the multi-pin in this work. The heat of the high temperature generated from the LED chip was directly transferred to the heat slug of the one large size. And the accumulated heat from the heat slug was quickly dissipated by the medium of the multi-pin, which is the same body with the heat slug. This multi-pin was designed for the multi-dissipation of heat by increasing the surface areas with a little pins. Subsequently, the speed of the heat transfer with this new heat-sink apparatus is three times faster than the conventional heat-sink. Therefore, the efficiency of the illuminating light will be improved by adapting this new heat-sink apparatus in the large area's LED.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 추계학술대회 논문집
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• pp.107-109
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• 2007

LED is expected as an environmentally friendly light source with its good reliability and long lifetime. A few ten mW white LED can substitute for the indicator light source, and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lamps. Since the optical technology used for several mW white LED light source uses only 30% to 50% of the light, it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.65-65
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• 2003

청색 발광 LEDs의 개발과 상용화 이후에 백색조명등의 응용 가능성으로 인하여 이에 대한 많은 연구가 최근에 계속되고 있다 하지만 GaN의 많은 광학적인 장점에도 불구하고 이러한 소자의 기판으로 사용되고 있는 sapphire의 열악한 열적 특성은 소자의 열화를 야기할 수 있으며 특히 고출력작동 시에 소자성능 저하의 원인이 될 수 있다. 따라서 이러한 GaN를 기본으로 하는 LED의 경우 이에 대한 정확한 열 측정과 고출력 작동 시의 열적 모델링은 칩과 패키징 단위에서 모두 중요한 연구분야가 되고 있다. 고출력 GaN LED에 대하여 신뢰성에 관한 몇 가지 보고가 있지만, 이러한 보고의 대부분은 패키징 된 램프에 대한 분석이며 정작 칩에 대한 근본적인 열 분석과 신뢰성에 대한 연구결과는 미미한 실정이다 따라서 본 연구에서는 GaN LED 칩에 대하여 직접적인 열 분석을 시도하였다