Zoom In - Beriled

More documents

Recommendations

Info

Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next PageABE FMaGSthermal | SYSTEM DESIGNLED chipHeatsinkInterconnectLED to substrateSubstrate or PCBessence and often the limitation of the entirethermal system. Even though a heat sinkseems to be the most straightforward component,it also has the highest potential foroptimization. Engineers are on the look outfor new and advanced materials and methodsto differentiate their heat sink design.For example, the introduction of thermally-conductiveplastics opens a newdimension of lighting solutions. Thermalsystems can now be integrated into theenclosure of products manufactured inhigh volumes by injection molding withthe added benefit of less weight. Accordingto Jeff Panek, GM of Cool Shield Inc., “MostThermalinterfacematerialFIG. 2. Schematic showing main elements of an LEDthermal system.of today’s SSL applications areconvection-limited rather thanconduction-limited. Therefore atless than 300 linear foot/minute(1.52 m/s) of air, a 20 W/mK thermalplastic heat sink can workas well as a 180 W/mK aluminumheat sink. This is becausethe system is not constrained byhow quickly the heat can move through thethermal system, but rather constrained byhow effectively it can convect the heat of thesurface into the ambient air.”The most efficient way to improve theresistance in the thermal path is to eliminatecertain thermal interfaces. This can beachieved, for example, by completely removingthe PCB and soldering the LED directlyonto the heat sink. Of course, this creates theproblem of connecting the LED to the powersupply in the absence of a PCB. One solutionis a molded interconnect device (MID) thatenables higher currents and higher light outputwith increased drive current while keepingthe junction temperature the same. Insuch a case the use of advanced materialsand methods can become the main enablerin meeting a specification like Energy Star®or reducing the component count for a morecost-effective solution.Thermal materialsThe thermal characteristics of power-LEDbasedsystems have caused engineers toadopt the metal-clad PCB (MCPCB) as a primarymaterial instead of FR4 boards. TheMCPCB “Star” board is a commonly-usedformat, but it raises system cost, resultingin ongoing work to reduce it withoutsacrificing performance. As shown in thetable on p.48, using MCPCB as the indexreference for star board designs, there arenow several alternatives that offer similaror even improved thermal performance atlower cost ratios.Thermal interface materials (TIMs) areused to connect a solid-state lighting assemblyto an external heat sink. Depending on_______________Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next PageABE FMaGS
Previous Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next PageABE FMaGSwebcastsMay 2009 Sponsorship OpportunityChallenges and Opportunities for the LED Lighting Fixture MarketSPEAKER: Vrinda Bhandarkar, Senior Market Research AnalystStrategies Unlimited, World’s Leader in Photonics Market ResearchIn recent years, LED technology has made impressive performance gains, which in turn have improved the efficacyof LED lighting fixtures. The adoption of LED lighting fixtures in the general lighting market will require a new wayof looking at lighting, and the value of lighting. The webcast will discuss the drivers and challenges that affect theemerging LED lighting fixture industry.SPONSORED BY:Future WEBCAST Topics in the LEDs and LightingSeries include:• HB LED Market Overview• Thermal Management (Part 2)• Green Lighting Model with LEDs• LED Drivers*Find out about the benefits of sponsoring the upcoming webcasts.• Understanding White LED Performance• Advantages and Drawbacks of LED Technology• Interior Illumination Using White LEDs• LED Design ChallengesArchived EventsLED Luminaire Photometry & Performance TestingSPEAKERS: Todd Straka, Director, Lighting Services , IntertekChristopher Durell, Vice President Sales & Applications Engineering, SphereOptics, LLCThis Webcast discusses performance standards developed for testing solid-state lighting products, includingLM-79 and LM-80. The speakers describe the testing requirements of these standards and other performancetesting options, explaining the types of measurement that are required and the relevant test methods. TheWebcast also looks in detail at the test equipment options that companies should consider, identifying the keypieces of equipment that are necessary to make the measurements for each standard. The Webcast also discussesenvironmental performance testing.More Archived EventsThermal Design for Enhanced LED PerformanceThis Webcast explores the fundamentals of thermal management, focusing on simulation and the correct choiceof materials.Market Trends and Emerging Applications in the LED IndustryThis presentation covers major trends in the HB-LED market, and reviews developments in the major applicationareas, focusing in particular on the LED lighting sector.Essentials for Designing LED LuminairesThis Webcast discusses the key design factors that need to be considered when building LED-based luminaires.VIEW ALL CURRENT, FUTURE AND ARCHIVED EVENTS AT:www.ledsmagazine.com/webcastsPrevious Page | Contents | Zoom in | Zoom out | Front Cover | Search Issue | Next PageABE FMaGS
Page 1: Contents | Zoom in | Zoom out For n
Page 4 and 5: Previous Page | Contents | Zoom in
Page 56: Previous Page | Contents | Zoom in

Zoom In - Beriled

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?