Tag Archives: heat sink

ATS releases test data on thermal resistance of its heatsink for LGA Socket

Posted on June 22, 2010 by | Leave a comment

We do alot of testing of our heatsinks here at Advanced Thermal Solutions. Our labs are regularly hot with test activity since we prefer to publish accurate test data on our product’s performance. Our LGA heatsink is one in particular.

Our ATS-57000 LGA Heatsink was put through it’s paces and we have some impressive test data.

Scenario: The required thermal target performance was 0.7°C/W with a 60W heat load and 12.4×15.3mm die size. The thermal solution was verified by 3 independent methods; analytical modeling, CFD simulations, and laboratory testing.

What did we do: First, an analytical approach was used to provide a first order calculation of thermal performance. From these calculations we found that a 40 millimeter fan would provide sufficient airflow to meet the cooling objective. These calculations provided a foundation on which to base our solid models on. After modeling the heatsink and fan, the assembly was simulated in CFDesign, a computational fluid dynamics software tool.

Once the optimal heatsink geometry was found in CFD simulation, a prototype was machined and tested in the ATS Fluids Laboratory. The testing involved several different interface materials from grease through phase change material.

What were the results?: During laboratory testing the heatsink thermal resistance was 0.51 to 0.58°C/W with various types of thermal grease. This performance level exceeds the given specification of 0.7°C/W with an 18% margin of safety. A further improvement of approximately 4% can be reached with a higher output AVC fan

Readers of our blog are welcome to email us for the full report. Also, our design is highly scalable to a custom version as well. Because we have an exisiting design your custom costs will be lower than anyone starting from scratch. Drop me some mail at [email protected] for your free copy of our report.

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LED Cooling Gets a Boost with Heraeus’ Stamped Circuit Board Technology but what about the cost?

Posted on June 17, 2010 by | Leave a comment

Yesterday we noted that SinkPAD had announced their new technology to directly cool LED. And now Heraeus, out of Germany, has made an announcement about their Stamped Circuit Board Technology to cool LED.

Heraeus’s concept is uses a new PCB manufacturing technique to basically use the PCB as an LED heatsink. You can check the following link to read about Heraeus’s Stamped Circuit Board Technology. But the basic approach is one where:

Stamped Circuit Board (SCB) technology combines structured layers of metal and plastic for use in substrate assemblies, e. g. of LEDs. Similar to printed circuit boards, this layering may consist of fiberglass-reinforced epoxy resin and copper – however, the separate structuring of the two materials opens the way for totally new design concepts. During the manufacturing process both the plastic and the metal are initially treated on separate reels and structured according to the specific requirements involved. At the next stage, the materials undergo lamination after which they are left perfectly aligned to each other.

One question Heraeus’s concept and that of SinkPAD’s brings to mind is: cost.

With LED’s rapidly replacing standard lighting technologies, that already have economies of scale in manufacturing, cost is still an issue.

We certainly need new technologies in LED lighting. In fact, we here at ATS announced a new LED heatsink technology partnership with Lemnis lighting back in January of this year.  Our announcement noted the following breakthrough:

Advanced Thermal Solutions, Inc. (ATS), has partnered with Lemnis Lighting B.V. to develop cooling solutions that will enable the next generation of Lemnis’ Pharox LED bulbs to light at cool temperatures, produce a bright, uniform light output and provide a long lifespan. The innovation increases LED light performance by 15%, placing a feasible alternative for the 75W bulb within reach.

New technologies that solve the various challenges that LED’s present are going to cost more with the offset being longer life, better for the environment, and reduction in energy consumption. However, the crossover point has to be thought through where the cost becomes prohibitive regardless of how useful the technology may be.   Given costs of manufacturing and materials for some of the new technologies,  LED heatsinks made from Aluminum may prove to be the cheapest and most reliable choice of all.

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Is CPU Cooling best done with a Copper Heatsink or Aluminum Heatsink?

Posted on June 16, 2010 by | 1 comment

The topic of whether a CPU heat sink should be a copper heat sink or aluminum heat sink comes up in every thermal management design. And the short answer as to which material to use is:

“It depends.”

There are many variables in designing the right heat sink, some of which include:

  • Thermal management cost budget relative to BOM cost
  • Orientation of boards (vertical or horizontal)
  • How much weight or stress can be applied to the target chip
  • How much keep out around a chip exists
  • Air flow to the chip
  • Air flow in and through the system (maybe you don’t need a heat sink at all as noted in an earlier ATS White Paper)
  • Component dimensions
  • Component height
  • Target junction temperature
  • Target case temperature

Let’s just focus on the material question though, copper heatsink vs. aluminum heatsink. Chris Soule, Engineering Director at Thermshield, has done a nice one page write up on the topic. Some of his key points include:

  • Pure copper has about two times the conductivity of aluminum but that inherent advantage is only helpful when
  1. Air Flow speeds are 800 LFM
  2. The hot spot on the CPU or other semiconductor is small in comparison to the size of the chip itself.
  • When air flow is 400 LFM or lower or the hot spot on the CPU or semiconductor is spread throughout the chip, then Aluminum is a better choice.
  • The cost of a copper heat sink is often up to three times the equivalent sized aluminum heat sink

In our labs here at ATS, we’ve found that if an aluminum heatsink by itself does not have the necessary thermal condutivity, then using phase change thermal interface material (such as those listed in our Thermal Interface Roundup Post) with the proper pressure applied can make the difference in cooling.

So which do you use? Copper or Aluminum? It depends on the variables noted including your budget. One thing is for sure, there is no clear, one sized fits all answer and the thermal engineer should carefully decide. Hopefully before the electrical design is complete!

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Posted in heat sink, Thermal Interface Material

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LED Thermal Management Company Uses New PCB Design as the LED Heat Sink

Posted on June 16, 2010 by | Leave a comment

We’ve talked a bit here at the ATS Thermal Blog about using a PCB as your heat sink. Tony Koryban specifically fielded a question on this topic in fact. Now, one of ATS’s friendly colleagues in the thermal management industry has invented a novel way to use the PCB as the LED heat sink itself.

SinkPAD Corporation, located in Anaheim, has launched it’s technology which:

… conducts heat out of the LED system (LED cooling) by enabling a direct thermal path between the LED and surrounding atmosphere, which eliminates thermal resistance introduced by the dielectric material in a traditional IMS PCB or MCPCB. The SinkPAD design completely removes the substance with the lowest thermal conductivity/highest thermal resistance from the structure. SinkPAD still uses a dielectric, but this dielectric isolates the metal base electrically and leaves it thermally connected. The thermal path should be electrically neutral within the LED package, i.e. Cree XLamp, Luxeon Rebel from Philips Lumiled, PhlatLight from Luminus, in order to solder the LED directly to the SinkPAD.

It’s pretty cool stuff and an exciting development for solid state lighting. You can learn more over at SinkPad’s site at www.sinkpad.com

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Thermal Management with ATS’s 55375 Cross Cut Heat Sink

Posted on June 14, 2010 by | Leave a comment

Thermal Management with ATS's 55375 Cross Cut Heat Sink The ATS-55375 heat sink from Advanced Thermal Solutions (ATS) provides high levels of cooling performance for BGAs, surface mount packages and other hot components that require maximum cooling from a passive (no fan) heat sink.

The ATS-55375 heat sink features a high efficiency cross-cut fin design that provides low pressure drop characteristics in limited airflow applications. The heat sink measures 37.5 x 37.5 mm, length by width, and is 24.5 mm high. Its large surface area enhances exposure of heat to cooling airflow. The black-anodized aluminum sink comes preassembled with a high performance thermal interface material (TIM) that enhances thermal transfer from component to sink.  Applications include Northbridge cooling.

For more information, to purchase or for samples, please visit QATS.com: ATS Cross Cut Heat Sink ATS-55375W-C2-R0

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