Tag Archives: LED thermal management

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.

Announcing our ATS Electronics Cooling Webinars for Third Quarter of 2012

ATS, Advanced Thermal Solutions, Inc. will present technical webinars on electronic cooling topics in July, August and September 2012. Each of these free events will provide engineering-level training in a key area of modern thermal management.

Here are the different webinar topics and presentation times:

Using Thermal Interface Materials to Improve Heat Sink Thermal Performance

July 26, 2012 at 2:00 p.m. ET

To cool hotter components, engineers are using larger fans and heat sinks, and increasing surface areas. These hardware enhancements can add significantly to design costs. In many cases, cooling performance can be improved by using a higher performance interface material between the case and the heat sink. Participants will learn the importance of lowering thermal resistance using thermal interface materials, or TIMs, and the different kinds of TIMs available from the market.

Air Jet Impingement Cooling

August 23, 2012 at 2:00 p.m. ET

Ongoing increases in power in devices such as processors and IGBTs mean that higher capacity cooling methods are needed to remove excess heat. One such method is the jet impingement of a liquid or gas onto a surface on a continuous basis. Lab experiments at ATS have shown up to a 40% improvement in cooling achieved using this method. This webinar will explore jet impingement cooling theory, implementation and best practices.

LED Thermal Management in Commercial and Consumer Lighting Applications

September 27, 2012 at 2:00 p.m. ET

Excess heat directly affects both short-term and long-term LED performance. The short-term effects are color shift and reduced light output, while the long-term effect is accelerated lumen depreciation and thus shortened useful life. Participants will learn how to diagnose and solve thermal issues in consumer and commercial LED applications.

Each of these one-hour online tutorials will include detailed visuals, real world examples, instructions, definitions and references. Audience questions will be answered by the presenters during and after the presentation. One or more ATS PhD-level thermal engineers will be presenting live.

There is no cost to attend these ATS webinars, but virtual seating is limited. Registration is available online at http://www.qats.com, or by calling 1-781-949-2522.



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/