0

Full Content is available to subscribers

Subscribe/Learn More  >

Understanding Longitudinal Fin Heat Sink Orientation Sensitivity for Light Emitting Diode (LED) Lighting Applications

[+] Author Affiliations
James Petroski

GELcore, Valley View, OH

Paper No. IPACK2003-35055, pp. 111-117; 7 pages
doi:10.1115/IPACK2003-35055
From:
  • ASME 2003 International Electronic Packaging Technical Conference and Exhibition
  • 2003 International Electronic Packaging Technical Conference and Exhibition, Volume 2
  • Maui, Hawaii, USA, July 6–11, 2003
  • Conference Sponsors: Electronic and Photonic Packaging Division
  • ISBN: 0-7918-3690-8 | eISBN: 0-7918-3674-6
  • Copyright © 2003 by ASME

abstract

Light Emitting Diodes (LEDs) have progressed in recent years from emitting indicator level lighting to emitting enough light for illumination applications. This has opened a new field for LED applications, resulting in significant advantages over conventional light sources and creating some application challenges unique to LEDs. Conventional lighting methods provide little guidance for LED thermal problems since these usually involve a very high temperature source, such as a filament or an arc, and radiant heat transfer dissipates the thermal energy. LED junction temperatures are limited to much lower values and hence the heat transfer system cannot depend upon radiant energy transfer. This means the cooling methods for lighting now shift from primarily radiation to conduction and natural convection, and this paradigm shift lighting designers must recognize when moving to LEDs. In this paper, the development of a LED-based spot module heat sink in a free convective cooling system is discussed. The rationale for choosing a cylindrical tube, longitudinal fin (CTLF) heat sink is shown, as is the performance of five different configurations of the heat sink in various orientations. The requirement for using heat sinks in various orientations comes from lighting applications, where the light may be installed in various directions, such as vertical up, vertical down, horizontal, or at almost any other angle. Heat sink test results are plotted for Nussult number versus standard and modified channel Rayleigh number, showing a similar correlation to the parallel plate heat sinks investigated first by Elenbaas. A different correlation for the isolated-plate limit section is proposed for CTLF heat sinks, as well as a proposed area of operation on these Nu-Ra curves for orientation-insensitive heat sinks. Finally, explanations for the different levels of sensitivities observed in different areas of the Nu-Ra curves are offered.

Copyright © 2003 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In