Tag Archives: anodization

Power Brick: #GoldStandard Heat Sinks for DC/DC Converters

Power Brick

ATS Power Brick heat sinks are the #GoldStandard for cooling eighth, quarter, half, and full brick DC/DC power converters. (Advanced Thermal Solutions, Inc.)

Advanced Thermal Solutions, Inc. (ATS) has a line of Power Brick heat sinks (available through Digi-Key Electronics and Arrow) that are specially designed to cool eighth-, quarter-, half-, and full-sized DC to DC power converters and power modules. Power Brick heat sinks feature ATS’ patented maxiFLOW™ design, which reduces the air pressure drop and provides greater surface area for more effective convection cooling.

Power Brick heat sinks are a critical component for the optimal thermal management of electronic devices because DC/DC power converters are used in many applications and across a number of industries, including communications, health care, computing, and more.

DC/DC converters are electronic circuits that convert direct current (DC) from one voltage to another. Converters protect electronic devices from power sources that are too strong or step up the level of the system input power to ensure it runs properly. The process works by way of a switching element that turns the initial DC signal into a square wave, which is alternating current (AC), and then passes it through a second filter that converts it back to DC at the necessary voltage.

As explained in an article on MaximIntegrated.com, “Switching power supplies offer higher efficiency than traditional linear power supplies. They can step-up, step-down, and invert. Some designs can isolate output voltage from the input.”

When converting electrical input to the proper voltage, DC/DC converters operate at a specified efficiency level, with some energy lost to heat. ATS Power Brick heat sinks provide the necessary step of dissipating that heat away from the converter to lower the junction temperature. This will optimize the performance of the component and ensure the longevity of the converter.

Anodization boosts Power Brick heat transfer capability

The pleasing gold color that has made Power Brick one of the most popular lines of heat sinks for DC/DC converters stems from the anodization process that ATS uses for its heat sinks. Anodization, as noted in an earlier blog post on this site, “changes the microscopic texture of a metal, making the surface durable, corrosion- and weather-resistant.”

Surface anodization works by turning the metal into the anode (positive electrode) of an electrolytic circuit. By passing an electric current through an acidic electrolytic solution, hydrogen is released at the cathode (negative electrode) and oxygen is released at the anode. The oxygen on the surface of the metal anode forms a deposit of metal oxide of varying thickness – anywhere from 1.8-25 microns.

The previous article explained, “The advantages of surface anodizing are the dielectric isolation of the cooling components from their electronics environment, and the significant increase in their surface emissivity.”

The emissivity coefficient of an anodized surface is typically 0.83-0.86, which is a significant boost from the standard coefficient of aluminum (0.04-0.06). By increasing the emissivity of the metal, there is also a significant enhancement of the metal’s radiant heat transfer coefficient.

The eye-catching gold color of ATS Power Brick heat sinks is added during the anodization process.

maxiFLOW™ design gives Power Brick an edge

Anodization of heat sinks is a standard practice to ensure that the metal components can withstand the rigors of dissipating heat from high-powered components. The feature that gives an ATS Power Brick heat sink the significant edge on its competitors is its patented maxiFLOW™ fin geometry, which has higher thermal performance for the physical volume it occupies compared to other heat sink designs.

maxiFLOW™ design is a low-profile, spread-fin array, which offers greater surface area for convection cooling. While it offers more surface area, it does not require additional space within the electronics package. This is an important feature in today’s electronics devices, which have an ever-increasing component density and in which space is always at a premium. This is an especially important feature for designers that want to cool DC/DC converters but are limited in the amount of available room.

Independent testing at Northeastern University of various heat sink designs demonstrated that maxiFLOW™ had the lowest thermal resistance for natural and forced convection, particularly when air flow velocity was below two meters per second. For heat sinks with the same base dimensions and fin height, maxiFLOW™ performed the best.

Testing has demonstrated that maxiFLOW™ can produce 20 percent lower junction temperatures and 40 percent lower thermal resistance than other heat sink designs. Utilizing maxiFLOW™ allows ATS Power Brick heat sinks to meet the industry standard base plate temperature of 100°C.
For more information about maxiFLOW™, watch the video below:

Power Brick meets industry standards

In the DC/DC market, there are a number of standard footprints that manufacturers use to offer flexibility for designers in choosing a vendor and in laying out a PCB. ATS has addressed the industry standard footprints with its Power Brick heat sinks. This will facilitate the use of the heat sinks for thermal management.

By optimizing the thermal management and meeting industry standards, Power Brick heat sinks can provide cost savings and reduce MTBF. Rather than having to over-design a system or a layout, engineers can turn to Power Brick as a thermal solution.

It is not only the industry standard footprints that Power Brick heat sinks have matched but also the standard hole patterns, which meet the standards set by the Distributed-power Open Systems Alliance (DOSA) to make assembly easy. The three millimeter holes (and soon 3.5 mm) match up to sizes commonly used in power brick manufacturing to ensure the proper connection for the heat sink (to avoid increasing the thermal resistance) and also to avoid using additional space in the tight confines of a PCB.

For the above reasons, Power Brick heat sinks are the “gold standard” for cooling DC/DC converters. Learn more in the video below:

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or ats-hq@qats.com.


i http://uk.rs-online.com/web/generalDisplay.html?file=automation/dc-converters-overview&id=infozone
ii https://www.maximintegrated.com/en/app-notes/index.mvp/id/2031
iii https://www.qats.com/cms/2010/11/09/how-heat-sink-anondization-improves-thermal-performance-part-1-of-2/
iv https://www.qats.com/cms/wp-content/uploads/2013/09/Qpedia_Oct08_How-Air-Velocity-Affects-HS-Performance.pdf

Why Blue and Green Color Anodization for Push Pin Heat Sinks?

ATS’s push pin heat sink line has a number of important characteristics but you’d think the least of them would be their color.   Why the colors and how do they help heat sinks be better heat spreaders – or do they?

First off, why the colors?   Are they there for marketing purposes or do they have a more engineering centric mission?  The colors are actually part of the anodization itself.    But first what is anodizing?   The Aluminum Anodizers Council has the key definition:

Anodizing is an electrochemical process that converts the metal surface into a decorative, durable, corrosion-resistant, anodic oxide finish. Aluminum is ideally suited to anodizing, although other nonferrous metals, such as magnesium and titanium, also can be anodized.

But most heat sinks are themselves inside electronic systems such as computers, telecommunications equipment.  Any electronic component that generates heat can benefit from a heat sink (also known as a heat spreader).   So, do heat sinks inside computers need to be protected by anodizing them?  The short answer is no.  There are use cases of course but in general, protection is not the reason heat sinks in general (and ATS’s Push Pin line of Heat Sinks) are anodized.  In many cases the anodization color makes it easier to brand the heat sink from a particular manufacture or to distinguish between different branches of a heat sink family.  In the case of ATS’s Push Pin Line, the green anodized heat sinks use ATS’s  ultra performance maxiFLOW™ fin geometries while the blue anodized heat sinks feature straight fin or cross-cut fin designs.

So anodization is just about marketecture?   Well, no.  While the colors are convenient and helpful the real answer is a technical reason.  As we’ve noted in our 2010 article series, “How Heat Sink Anodization Improves Thermal Performance (see them on qats.com at these links, part 1 and part 2)”  anodization is about treating the surface of the heat sink to improve the radiation heat transfer of the heat sink:

Radiation heat transfer can be as important as convection heat transfer in electronics cooling, especially in natural convection and low-airflow applications.  Depending on the type of surface treatment used, radiation heat transfer is enhanced in two distinct ways: by increasing the emissivity of the surface or by increasing the surface area.  Anodization is one such way to treat the surface area.

Various protective benefits and aesthetically pleasing colors have extended the use of anodization to many industrial and commercial applications. For electronics cooling, however, the advantages of surface anodizing are the dielectric isolation of the cooling components from their electronics environment, and the significant increase in their surface emissivity. The increase in the emissivity coefficient on the anodized surfaces of heat exchangers, electronics cabinets and enclosures, heat sinks, etc. is typically on the order of 0.83 to 0.86 [4]. When compared to the emissivity coefficient of bare aluminum, 0.04 to 0.06 [5], the importance and significance of enhancement of radiation heat transfer would become evident.

So for ATS’s push pin heat sinks and for other firms who anodize their heat sinks the reason is really for the purpose of improving the thermal performance of the heat sink.  Also available through Digi-Key!

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