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| | Managing heat in power LED systems for optimal performance | | When designing a solid-state solution with power LEDs, one cannot underestimate the importance of the thermal system design, as encapsulated in the phrase “Think Thermal First”. Rudi Hechfellner explains. | |
To understand the role of thermal design in LEDs, it’s important to review how system and electronic drive conditions influence light output performance and long term behavior of high-power LEDs. The parameters are all influenced by the junction temperature of the LEDs, demonstrating the importance of this subject.
Temperature has a direct impact on optical and electrical performance as well as on the overall quality and reliability of an LED-based product. Therefore, it is critical that engineering teams understand the system’s thermal parameters, and focus on thermodynamic competencies.
These parameters are all interconnected. For example, a higher drive current should increase the light output of the LED. However, the higher current increases the dissipated power, causing heating within the LED, which has a negative impact on light output. Also, conversely, a higher junction temperature (caused for example by a higher ambient temperature) causes a reduction in the LED’s forward voltage, reducing the dissipated power for a constant-current source.
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This article was published in the April 2009 issue of LEDs Magazine.
To read the full version of this article, please visit our Magazine page, where you can download FREE electronic PDF versions of all issues of LEDs Magazine.
You can also request a print copy of LEDs Magazine (available by paid subscription) and sign up for our free weekly email newsletter. | | About the Author | | Rudi Hechfellner is technical marketing manager with Philips Lumileds Lighting Company (www.philipslumileds.com), San Jose, California, USA. | | COMMENTS | | Name: davidlin7991 Posted: Thu, 05 Jan 2012 12:01 |
| I publish a paper related the thermal management of LED array, If you are interesting, I can provide the related design method to you.
2011, Optimization of thermal management by the integration of SCGM, finite element method and experiment on the high power LED array, IEEE Transaction on Electron Devices, Vol. 58, No. 4, pp. 1141-1148 |
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