Tag Archives: LED cooling

ATS Design Services Contacted for ECL’s New Recycled LED Street Light

Eco City Lights (ECL), a leading supplier of commercial and industrial LED lighting products, recently contacted ATS design services for help in solving thermal challenges on a newly developed application.

ATS performed a full thermal analysis on ECLs retro-fit solution for cobra head street lights. Services provided by ATS included simulation, validation and reporting for the heat sink, enclosure and system level applications. Experimentation was done in order to validate and optimize the current design and the thermal solution. Using IR Technology and multiple sensors throughout the fixture, LED, heat sink, and power supply, testing was performed to determine the true temperatures of the output and enclosure parameters. After numerous studies were conducted, in addition to reviewing 3D CAD models of the enclosure and application components, ATS was able to successfully analyze the existing thermal management solution for the retro-fit street light.

ATS performed testing and analysis on the LED application

ATS performed testing and analysis on the LED application

Eco City Lights felt it was most important to find a thermal management company to evaluate, analyze, and comment on our led lighting solutions. “After researching our options ECL determined that ATS was the best qualified to handle our project. After personally visiting with Joe Gaylord of ATS and talking with their engineers, we now have a product line that is thermally tested, proven, and cost effective. As our company continues to grow, we will be adding addition products and look forward to working with ATS in the future” said Ken Moeller, President of Eco City Lights.

ECL's Cobra Head Street Light

ECL’s Cobra Head Street Light

Eco City Lights LED products are used in street, sidewalk, parking lot and warehouse applications for municipal, government, and commercial enterprises. It is crucial that the LEDs thermal performance is maximized, ensuring product reliability and an extended lifespan. The new recycled LED streetlight module is proven to save customers over 60 percent of energy consumptions costs, providing long lasting, low maintenance, and energy efficient LED lighting.

From its computational facilities and thermal/fluids laboratories in Massachusetts, ATS specializes in providing thermal analysis, mechanical and design services for the telecommunications, networking, medical, aerospace, defense, embedded computing, and automotive industries with high performance electronic products. To learn more about ATS Design Services, call 781-769-2800, email ats-hq@qats.com, or visit www.qats.com.

New Qpedia Thermal eMagazine Published!

Qpedia Thermal eMagazine, Volume 6, Issue 11, has just been released and can be downloaded at: http://www.qats.com/Qpedia-Thermal-eMagazine/Back-Issues. Featured articles in this month’s issue include:

Honeycomb Heat Sinks for LEDs

LEDs, or light-emitting diodes, are a form of solid-state lighting. An LED light is often made of a small piece of semiconductor, an integrated optical lens used to shape its radiation pattern, and a heat sink, used to dissipate heat and maintain the semiconductor at low operating temperature. LED lights present many advantages over incandescent light sources, including lower energy consumption, longer lifetime, improved physical robustness, smaller size and faster switching. This article examines Ma et al’s  findings with respect to the honeycomb heat sink design employed in LEDs, which has proven to be highly efficient.

Characteristics of Thermosyphons in Thermal Management

With the increase of heat fluxes and shrinking chip sizes in electronics applications, there is a need to spread the heat from the small chip to the larger heat sink or to transport the heat to a location where there is ample space to remove the heat. Heat pipes, vapor chambers and thermosyphons have been introduced to undertake this task and, in this article, we focus on some aspects of the design of thermosyphons. The advantage of thermosyphons is that they have no capillary limit and can transport large amounts of heat over long distances.

Industry Developments: Heat Pipes Providing High Performance

Heat pipes are increasing in type and use for the benefits they provide. Because of their lower total thermal resistance, heat pipes transfer heat more efficiently and evenly than solid aluminum or copper. Heat pipes contain a small quantity of working fluid (e.g. water, acetone, nitrogen, methanol, ammonia). Learn the conclusions of a recent study that focused on the best working fluid and another study of heat pipes in outer space.

Technology Review: Cold Plates, 2010 to 2012

Qpedia continues its review of technologies developed for electronics cooling applications. We are presenting selected patents that were awarded to developers around the world to address cooling challenges. After reading the series, you will be more aware of both the historic developments and the latest breakthroughs in both product design and applications.

Cooling News featuring the latest product releases and buzz from around the electronics cooling industry.

Download the issue now.

Not a Qpedia subscriber? Subscribe Now for free at: http://www.qats.com/Qpedia-Thermal-eMagazine/Subscribe-to-Qpedia and see why over 18,000 engineers read Qpedia.

Holiday Sale: 25 % Off Qpedia Book Series!


coolingZONE is running a holiday promotion on the Qpedia Book Series, discounting 25% off the normal retail value until December 31, 2012. Qpedia Thermal eMagazine is the official media sponsor of coolingZONE. The Qpedia book series provides an expert resource for engineering professionals, professors, students and others who want to learn more about the theories and applications of electronics thermal management.

The four volume set contains nearly 200 in-depth articles, researched and written by veteran engineers. They address the most critical areas of electronics cooling, with a wide spectrum of topics and thorough technical explanation. Each article features color illustrations and images along with important thermal calculations and formulas.

Qpedia Volume 1 topic highlights:

– Heat sink design

– Pool boiling

– Sensors

– Thermal chassis

– Pitot tubes

– Heat transfer

Qpedia Volume 2 topic highlights:

– Thermal grease

– Vapor chamber cooling

– Liquid cooling

– Natural convection cooling

– Phase change materials

Qpedia Volume 3 topic highlights:

– CFD modeling

– PCB optimization

– Jet impingement cooling

– LED cooling

– Cold plates

– Refrigeration systems

Qpedia Volume 4 topics highlights:

– Multilayer mini-channel heat sinks

– Electro-osmotic pumps

– Thermoelectric coolers

– High altitude heat transfer

– Data center cooling

– Defense electronics

– Automotive electronics cooling

Check out the video on Qpedia Volume 4

Over fifteen thermal and mechanical engineers combined their expertise to create the articles in this useful collection, including Kaveh Azar, Ph.D. and Bahman Tavassoli, Ph.D., both of whom are internationally recognized experts in the field of the thermal management of electronics. Qpedia Thermal eMagazine, published by Advanced Thermal Solutions, Inc. (ATS) was launched in 2007 as a technical publication dedicated to the thermal management of electronics.

Filled with careful explanations, step-by-step calculations, and practical examples from real life challenges, this expert collection of articles is a must have for any mechanical, electrical, and thermal engineer or anyone interested in the rapidly growing field of electronics cooling.

Order the Qpedia Book Series with 25% off now at www.coolingzone.com The books can be purchased as a complete set, combination, or individually. Volume discounts for organizations and academic institutions are also available.

Cooling High Power LEDs

Most LEDs are designed in SMT (surface mount technology) or COB (chip-on-board) packages. In the new 1~8W range of surface mount power LED packages, the heat flux at the devices thermal interface can range from 5 to 20 W/cm2. These AllnGaP and InGaN semiconductors have physical properties and limits similar to other transistors or ASICs (application specific integrated circuit). While the heat of filament lights can be removed by infrared radiation, LEDs rely on conductive heat transfer for effective cooling.

As higher powers are dissipated from LED leads and central thermal slugs, boards have changed to move this heat appropriately. Standard FR-4 technology boards can still be used for LEDs with up to 0.5 W of dissipation, but metallic substrates are required for higher levels. A metal core printed circuit board (MCPCB), also known as an insulated metal substrate (IMS) board, is often used underneath 1W and larger devices. These boards typically have a 1.6 mm (1/16 inch) base layer of aluminum with a dielectric layer attached. Copper traces and solder masks are added subsequently. The aluminum base allows the heat to move efficiently away from the LED to the system.

Increasing power density, a higher demand for light output, and space constraints are leading to more advanced cooling solutions. High-efficiency heat sinks, optimized for convection and radiation within a specific application, will become more and more important.

As with any semiconductor package, thermal resistance plays a significant role in the thermal management of LEDs. The highest thermal resistance in the heat transfer path is the junction-to-board thermal resistance (Rj-b) of the package [2]. Spreading resistance is also an important issue. Thermally enhanced spreader materials, such as metal core PCBs, cold plates, and vapor chambers for very high heat flux applications are viable systems to reduce spreading resistance. [3]

Linear heat sinks are available specifically for LED strips, such as OSRAM SYLVANIA’s DRAGONstick® linear LED strips, which are widely used in architectural lighting. For example,the maxiFLOW linear heat sink from Advanced Thermal Solutions, Inc., has a patented spread fin array that maximizes surface area for more effective convection (air) cooling, particularly when air flow is limited, such as inside display cases.

Round heat sinks are available specifically for round LED boards, which are used to replace halogen light bulbs, in applications such as spotlights and down lighting. A typical LED spotlight is shown in Figure 2 [5]. Here, a round QooLED© heat sink from Advanced Thermal Solutions is used for cooling three LEDs. The round heat sink has a special star-shaped profile fin design that maximizes surface area for more effective convection (air) and radiation cooling in the vertical mounting orientation, e.g., inside ceilings.

Active thermal management systems can be used for high-flux power LED applications. These include water cooling, two-phase cooling, and fans. Although active cooling methods may not be energy-justifiable for LEDs, reasons for using them include ensuring lumen output or maintenance-free operation, or to meet specific wavelength requirements.

Check out the new and improved LED Cooling Resource Kit

ATS, Advanced Thermal Solutions, Inc, has compiled several expert technical resources for thermally managing LED lighting. The Expert Resource Kit for Better Thermal Management of LED Lighting is compendium of free downloadable information.

The Kit is specifically for thermal management professionals in the LED lighting industry and for engineers who are responsible for ensuring the proper performance of LED designs.

Included in the Resource Kit are:

  • LED Heat Transfer and Cooling Options: Lighting the Way for LED Development
  • Mentor Graphics Webinar (free registration required): Diagnosing and Solving Thermal Challenges in Next Generation LED
  • ATS Case Study: Feasibility Study of an LED-Based Lighting System Using Analytical Modeling
  • ATS Article: How to Cool High Power LEDs
  • Clemens Lasance Lecture on LED Thermal Management: Thermal Management for LED Applications: What is the Role of the PCB?
  • Clemens Lasance, Michael Gay, Norm Berry, Richard A. Wessel on MCPCBs for LED Applications:MCPCBs for LED Applications, Thermal Management Material Specifications
  • Dr. Kaveh Azar Video Interview: LED Heat Sink Types and Applications

The free LED Cooling Resource Kit can be accessed at: http://qats.com/cms/free-thermal-management-led-lighting-resource-kit/