scholarly journals Analyzing Thermal Module Developments and Trends in High-Power LED

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jung-Chang Wang
Keyword(s):  
Life Cycle ◽  
High Power ◽  
Light Emitting Diode ◽  
Junction Temperature ◽  
Light Emitting ◽  
Consumer Electronic ◽  
High Power Led ◽  
Fin Thickness ◽  
Good Agreement ◽  
Indoor And Outdoor

The solid-state light emitting diode (SSLED) has been verified as consumer-electronic products and attracts attention to indoor and outdoor lighting lamp, which has a great benefit in saving energy and environmental protection. However, LED junction temperature will influence the luminous efficiency, spectral color, life cycle, and stability. This study utilizes thermal performance experiments with the illumination-analysis method and window program (vapour chamber thermal module, VCTM V1.0) to investigate and analyze the high-power LED (Hi-LED) lighting thermal module, in order to achieve the best solution of the fin parameters under the natural convection. The computing core of the VCTM program employs the theoretical thermal resistance analytical approach with iterative convergence stated in this study to obtain a numerical solution. Results showed that the best geometry of thermal module is 4.4 mm fin thickness, 9.4 mm fin pitch, and 37 mm fin height with the LED junction temperature of 58.8°C. And the experimental thermal resistances are in good agreement with the theoretical thermal resistances; calculating error between measured data and simulation results is no more than ±7%. Thus, the Hi-LED illumination lamp has high life cycle and reliability.

Thermal Analysis of High Power Light Emitting Diodes Package

2011 ◽  
Vol 687 ◽  
pp. 215-221
Author(s):  
Yuan Yuan Han ◽  
Hong Guo ◽  
Xi Min Zhang ◽  
Fa Zhang Yin ◽  
Ke Chu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
High Power ◽  
Thermal Field ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Convective Heat Exchange ◽  
Input Power ◽  
Junction Temperature ◽  
Original Structure ◽  
Light Emitting

With increasing of the input power of the chips in light emitting diode (LED)， the thermal accumulation of LEDs package increases. Therefore solving the heat issue has become a precondition of high power LED application. In this paper, finite element method was used to analyze the thermal field of high power LEDs. The effect of the heatsink structure on the junction temperature was also investigated. The results show that the temperature of the chip is 95.8°C which is the highest, and it meets the requirement. The conductivity of each component affects the thermal resistance. Convective heat exchange is connected with the heat dissipation area. In the original structure of LEDs package the heat convected through the substrate is the highest, accounting for 92.58%. Three heatsinks with fin structure are designed to decrease the junction temperature of the LEDs package.

High Power LED Integrated With Silicon-Based Thermoelectric Cooler Package

2007 ◽  
Author(s):  
Ming-Ji Dai ◽  
Chih-Kuang Yu ◽  
Chun Kai Liu ◽  
Sheng-Liang Kuo
Keyword(s):  
High Power ◽  
Flip Chip ◽  
Light Emitting Diode ◽  
Infrared Camera ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Thermoelectric Cooler ◽  
High Power Led ◽  
Silicon Based ◽  
Light Efficiency

A new thermal management application of silicon-based thermoelectric (TE) cooler integrated with high power light emitting diode (LED) is investigated in present study. The silicon-based TE cooler herein is fabricated by MEMS fabrication technology and flip-chip assembly process that is used for high power LED cooling. An electrical-thermal conversion method is used to estimate the junction temperature of LED. Moreover, the Integrating Sphere is also used to measure the light efficiency of LED. The thermal images photographed by infrared camera demonstrated the cooling function of the silicon-based TE devices. The results also show that high power LED integrated with silicon-based thermoelectric cooler package can effectively reduce the thermal resistance to zero. In addition, the light efficiency of the LED (1W) will increase under low TE cooler input power (0.55W), which is about 1.3 times of that without TE cooler packaging.

5mm × 5mm Sized Slug on High Power LED Stress and Junction Temperature Analysis

2013 ◽  
Vol 404 ◽  
pp. 460-464
Author(s):  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Fairul Afzal Ahmad Fuad ◽  
Phaklen Ehkan ◽  
Rajendaran Vairavan ◽  
...  
Keyword(s):  
High Power ◽  
Light Emitting Diode ◽  
Input Power ◽  
Junction Temperature ◽  
Temperature Analysis ◽  
Single Chip ◽  
Physical Size ◽  
Light Emitting ◽  
Simulation Results ◽  
Incandescent Lamps

Conventional incandescent lamps are being replaced by high power light emitting diode as a lighting source due to it ascendancy in terms of physical size, performance, output and lifetime. Nevertheless, the reliability and efficiency of the LED is dependent on the junction temperature. This study presents the thermal simulation of single chip LED package with 5mm x5mmx 1mm aluminum heat slug. The junction temperature and stress of LED chip were evaluated using Ansys version 11. Input power of 0.1 W and 1 W were applied to the LED. The simulation results showed that at input power of 1W, the maximum junction temperature and stress of the LED chip is 112.91°C and 263.82Mpa respectively.

Thermal Characteristics of High-Power LED Packages with Dissipation Film

2013 ◽  
Vol 397-400 ◽  
pp. 1767-1771
Author(s):  
Cheng Yi Hsu ◽  
Yu Li Lin
Keyword(s):  
High Power ◽  
Diamond Film ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Thermal Characteristics ◽  
Large Change ◽  
Junction Temperature ◽  
Conduction Model ◽  
Element Analysis ◽  
Light Emitting

A simple, fast, and reliable characterization method for measuring junction temperature (Tj) on high power GaN-based light emitting diodes (LED) was presented in this study. Thermal characteristics of high power Light-emitting-diode have been analyzed by using a three-dimensional thermal conduction model. Maximum operation temperature has also been calculated. The induced thermal behaviors of the best package processes for LED device with diamond film were investigated by finite element analysis (FEA) and by experimental measurement. The large change of forward operation voltage with temperature in light emitting diodes is advantageously used to measure junction temperature. Using this method, junction temperature (Tj) of LED under various structures and chip mounting methods was measured. It was found that the junction temperature can be reduced considerably by using diamond film substrates to replace sapphire substrate. In this study, the junction temperature can be decreased by about 14.3% under 1.5W power and decreased by about 15.9% under 1W power for 1mm square die. The thermal resistance (RT) can be measured to be 14.8°C/W under 1.5W power and 16.6°C/W under 1.W power.

Numerical Analysis for Thermal Performance of High Power Multi-Chip LED Packaging

2010 ◽  
Vol 139-141 ◽  
pp. 1433-1437
Author(s):  
Kai Lin Pan ◽  
Jiao Pin Wang ◽  
Jing Liu ◽  
Guo Tao Ren
Keyword(s):  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Light Emitting ◽  
Die Attach ◽  
Dissipation Model ◽  
Key Issues

Heat dissipation and cost are the key issues for light-emitting diode (LED) packaging. In this paper, based on the thermal resistance network model of LED packaging, three-dimensional heat dissipation model of high power multi-chip LED packaging is developed and analyzed with the application of finite element method. Temperature distributions of the current multi-chip LED packaging model are investigated systematically under the different materials of the chip substrate, die attach, and/or different structures of the heat sink and fin. The results show that the junction temperature can be decreased effectively by increasing the height of the heat sink, the width of the fin, and the thermal conductivity of the chip substrate and die attach materials. The lower cost and higher reliability for LED source can be obtained through reasonable selection of materials and structure parameters of the LED lighting system.

Thermal Management for High Power Light-Emitting Diode Street Lamp

2010 ◽  
Author(s):  
M. Ying ◽  
S. M. L. Nai ◽  
P. Shi ◽  
J. Wei ◽  
C. K. Cheng ◽  
...  
Keyword(s):  
Thermal Management ◽  
Thermal Performance ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
System Level ◽  
Light Emitting ◽  
High Power Led ◽  
Street Lamp ◽  
Lamp System

Light-emitting diode (LED) street lamp has gained its acceptance rapidly in the lighting system as one of choices for low power consumption, high reliability, dimmability, high operation hours, and good color rendering applications. However, as the LED chip temperature strongly affects the optical extraction and the reliability of the LED lamps, LED street lamp performance is heavily relied on a successful thermal management, especially when applications require LED street lamp to operate at high power and hash environment to obtain the desired brightness. As such, a well-designed thermal management, which can lower the LED chip operation temperature, becomes one of the necessities when developing LED street lamp system. The current study developed an effective heat dissipation method for the high power LED street lamp with the consideration of design for manufacturability. Different manufacturable structure designs were proposed for the high power street lamp. The thermal contact conductance between aluminum interfaces was measured in order to provide the system assembly guidelines. The module level thermal performance was also investigated with thermocouples. In addition, finite element (FE) models were established for the temperature simulation of both the module and lamp system. The coefficient of natural convection of the heat sink surface was determined by the correlation of the measurement and simulation results. The system level FE model was employed to optimize and verify the heat dissipation concepts numerically. An optimized structure design and prototype has shown that the high power LED street lamp system can meet the thermal performance requirements.

Effect of Temperature and Current on Luminous Efficiency of High Power LED

2011 ◽  
Vol 347-353 ◽  
pp. 310-313 ◽  
Author(s):  
Feng Rao ◽  
Zhi Chen Ge ◽  
Jin Lian Zhu
Keyword(s):  
Energy Saving ◽  
White Light ◽  
High Power ◽  
Light Emitting Diode ◽  
Luminous Efficiency ◽  
Effect Of Temperature ◽  
Light Emitting ◽  
Led Light ◽  
High Power Led ◽  
Changing Rate

Luminous efficiency of high power white light LED (light emitting diode) at different temperature and driver current is measured with the photometric, chromatic and electric characteristics analyzer. It is shown that the luminous efficiency decreases as the temperature and (or) the driver current increases. The highter the driver current is, the more strongly temperature worsens the efficiency. However, the changing rate of efficiency with current is similar at different temperature. At last, a luminous efficiency model with temperature and current is constructed. This research is very important for the design of energy-saving LED lamps.

Simulation Research on the Heat Dissipation Performance of a High Power LED Radiator

2012 ◽  
Vol 224 ◽  
pp. 389-394
Author(s):  
Shu Zhen Jiang ◽  
Zhong Ning Guo ◽  
Yu Deng
Keyword(s):  
Thermal Analysis ◽  
Life Span ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Environment Friendly ◽  
Simulation Research ◽  
Light Emitting ◽  
High Power Led ◽  
Long Life

Applied in illumination area, high power LED (Light Emitting Diode) has a series of advantages with energy saving, environment-friendly, long life span, etc. However, the heat dissipation of the LED is a bottleneck in its development, and has become a key point which must be studied and solved urgently. In this paper, a typical LED lamp is modeled and thermal analysis has been performed using the software of Ansys.

The Design of High Power LED Headlamp

2013 ◽  
Vol 423-426 ◽  
pp. 2098-2103
Author(s):  
Wen Lin Chen ◽  
Zhen An ◽  
Chao Qun Xiang ◽  
Chen Yang Liu ◽  
Li Na Hao
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Current Drive ◽  
Constant Current ◽  
Light Emitting ◽  
High Power Led ◽  
Drive Circuit ◽  
Led Headlamp ◽  
The Stability

With the continuous development of LED(Light-Emitting Diode) manufacturing technology, the high power white LED is gradually applied in the field of all kinds of lighting .But with working time increasing of LED chips, their junctions temperature continue increasing, which lead to decrease light-emitting efficiency and reliability of LED chip, and even be failure. According to the serious heating of LED chip, this paper has been designed a fin-type aluminum radiator panels using Pro/E software. A LED constant current drive circuit is designed by using LTC3783 chip. With the ANSYS software, thermal analysis was carried out on the fin-type aluminum radiator panels, and eventually the mode of high power LED headlamps is determined. The stability of the LED constant current drive circuit is verified through experiments. The LED headlamps of 90W worked for ten hours, and the results of the experiments showed that the LED chip junctions temperature measured are less than 75°Cso we can solve heat dissipation of high power LED headlamps effectively.

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