Tag Archives: wind tunnels

ATS Wind Tunnels Designed for SSD and PCIe Thermal Characterization

As was outlined in an earlier article on this blog, it is critical for manufacturers to characterize solid-state drives (SSD) to establish performance parameters in real-world conditions. The previous article explained that SSD experience higher failure rates and reduced lifespan when temperatures increase beyond the standard operating range of 30-40°C.

Wind Tunnels
ATS designed wind tunnels for companies looking to characterize solid-state drives in the PCIe form factor, as show above. (Wikimedia Commons)

Testing processes for SSD are similar to those used for characterizing typical semiconductors. A wind tunnel provides a consistent, controlled, and repeatable environment for data collection and sensors, thermocouples, and an analog-to-digital capture system allows engineers to measure performance when the SSD is impacted by external factors.

ATS designs and fabricates research-quality wind tunnels that can be used for characterizing SSD. The wind tunnels give engineers control over air temperature and velocity. Closed-loop wind tunnels can create environments with temperatures as high as 80°C to provide stressed conditions well above standard operating temperatures. The manufacturer can use this data to set reference points for different environments, such as in 1-U telecommunications chassis or large server boxes.

Recently, ATS has worked with two of the industry’s largest producers of SSD to design wind tunnels that could be used for characterizing drives in PCIe applications. PCIe (peripheral component interconnect express) cards are high-speed serial computer extension cards that connect peripheral devices to the motherboard. In addition to SSD, these cards can be used for graphics processors, Wi-Fi, or other hard drives.

ATS wind tunnels can be used to test airflow and thermal performance for components and boards, as shown in this smoke flow visualization test over a maxiFLOW™ heat sink. (Advanced Thermal Solutions, Inc.)

One of the wind tunnels was a standard, open loop CWT-107™. It can produce uniform and homogeneous flow, up to 5.5 m/s (1100 ft/min) within the wind tunnel’s test section due to its polynomial shape and internal flow management system, which features honeycombs and screens to break up turbulence. The wind tunnel can be operated either vertically or horizontally and the customer chose to use it lying down.

In fact, the customer was very creative in its use of the wind tunnel. A customized cart was built for the wind tunnel to be bolted to and then the cart was wheeled into a large environmental chamber where temperatures could be raised to test levels. The SSD being characterized was a PCIe card with memory installed. There was no fan for the memory and the memory had no shielding or housing.

The customer placed its PCIe-based SSD flat in the test chamber. Power was pulled through the test ports included in the test chamber of the CLWT-107™ (as shown below).

While the wind tunnel was bought for testing SSD, it could be used by the customer to test any electronic component or board.

The second customer purchased a CLWT-115™ closed-loop wind tunnel. In this case, the application required the SSD to be powered through the PCIe back plane, so ATS custom-designed slots in the test section to fit the PCIe form factor. The slots allowed the SSD to remain inside the test section and be connected to a motherboard residing outside the wind tunnel (see below).

Again, the wind tunnel could be used to test any PCIe cards, not just SSD, if the customer desired, as there were also fillers created for the slots to allow the wind tunnel to be used when testing other devices.

The second customer did all of its air velocity and temperature testing in the CLWT-115™, rather than using an environmental chamber like the first customer, because the wind tunnel has a self-contained heating unit that heats air while it circulates during testing.

Wind tunnel controllers and ATVS systems were also purchased by both customers to ensure accurate data collection. The first customer bought an ATVS-NxT™, which is a fully portable scanner that operates with an embedded PC and touch screen control, while the second customer bought the ATVS-2020™, which allows single- or multi-point measurement of both temperature and velocity, and a CLWTC-1000™, which automatically controlled the airflow and temperature through the test chamber.

Both come with Candlestick sensors to control the air velocity in the wind tunnel and thermocouples to control the temperature.

One of the customers also requested a custom, rugged sensor to avoid damage through multiple uses. ATS was able to adapt one of its handheld surface probes, a stainless-steel probe with a pointed tip for exact positioning of the sensor on the desired spot, by reducing the length and designing a custom port that would hold the sensor in place.

SSD are gaining traction in the market, with major hard drive manufacturers and the companies that utilize them both making the switch to solid-state technology. This means that thermal characterization of SSD and thermal management systems deployed to dissipate the heat of these drives are going to be of increasing importance in the coming years.

Using research-quality wind tunnels gives manufacturers a leg up in determining how their drives will perform in different real-world environments and makes the process of SSD characterization easier for users. By working with ATS, companies can tailor their wind tunnels to their specific applications and can be assured of the accuracy of the data that they collect.

Learn more about ATS wind tunnels, sensors, and the entire line of next-generation thermal test instruments at https://www.qats.com/Products/
Instruments. If you have questions about any products or ATS thermal testing services, email ats-hq@qats.com.

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

In the ATS Labs – Where Thermal Solutions Advance to Meet Industry Demands

Thermal management innovations need to match the rapid pace at which the electronics industry is advancing. As consumers demand new and more powerful devices or greater amounts of information at faster speeds, cooling solutions of the past will not be enough. Today’s cooling solutions must be smaller, lighter, and offer higher performance, but also need to be cost-effective, meet demanding project specifications, and be reliable for many years.

Advanced Thermal Solutions, Inc. (ATS) understands the importance of creating cutting-edge thermal solutions for its customers and has geared its thermal design capability and its research and development to match the innovations taking place in electronics design.

ATS Labs

An ATS engineer assembles a rig for testing cold plates in one of ATS’ six state-of-the-art labs. (Advanced Thermal Solutions, Inc.)

To meet the need for innovative solutions, ATS engineers are hard at work in the company’s six state-of-the-art laboratories at the ATS headquarters, located in Norwood, Mass. (south of Boston). Thermal issues of all kinds are recognized, broken down, and resolved and cooling solutions are designed, simulated, prototyped, and rigorously tested in these research-grade facilities.

When someone thinks of a research lab, the initial picture is scientists in white coats working for major corporations, such as IBM, Microsoft, or Google, but the development of new ideas is an essential tool for any company in the technology field. Working with empirical tests in a lab environment pushes concepts from the white board or the computer screen to reality. There comes a time when engineers need to produce tangible data to ensure that a design works as planned.

ATS thermal engineers are no different. They use state-of-the-art instruments and software in each of the six labs to conduct a long list of characterization, quality-assurance, and validation tests. In addition to finding custom cooling solutions for customers, ATS engineers produce thermal management products for commercial uses, including a variety of next generation heat sink, heat pipe, vapor chamber, and liquid cooling designs.

Engineers test ATS instruments using a wind tunnel and sensors in the Characterization Lab. (Advanced Thermal Solutions, Inc.)

Among the most common tests performed in the ATS labs are:

• Measurements of air velocity, direction, pressure and temperature;
• Characterization of heat sink designs, fans and cold plates
• Flow visualization of liquid and air flow
• Image visualization characterization using infrared and liquid crystal thermography.

Many of the instruments that these tests are performed on were designed and fabricated by ATS. That includes open-loop, closed-loop, and bench-top wind tunnels; the award-winning iQ-200™, which measures air temperature, velocity, and pressure with one instrument; and the thermVIEW™ liquid crystal thermography system. Engineers also use specially-designed sensors, such as the ATS Candlestick Sensor, to get the most accurate analysis possible.

Smoke flow visualization tests run in ATS wind tunnels demonstrate how air flows through a system. (Advanced Thermal Solutions, Inc.)

Heat pipes and vapor chambers are increasingly common cooling solutions, particularly for mobile devices and other consumer electronics, and ATS engineers are working to expand the company’s offerings for these solutions and to develop next generation technology that optimizes the thermal performance of these products. This research involves advanced materials, new fabrication methods, performance testing, and innovative designs that are ready for mass production.

ATS engineer Vineet Barot sets up a thermal imaging camera for temperature mapping studies in the lab. (Advanced Thermal Solutions. Inc.)

ATS has also developed products to meet the growing demand across the electronics industry for liquid cooling systems. From new designs for recirculating and immersion chillers to multi-channel cold plates to tube-to-fin heat exchangers, ATS is continuing to expand its line of liquid cooling solutions to maximize the transfer of heat from liquid to air and researching new manufacturing methods, advanced materials, and other methods of enhancing the technology.

As liquid cooling technology has grown, ATS has met this demand with new instruments and lab capabilities, such as the iFLOW-200™, which measures a cold plate’s thermal and hydraulic characteristics, and full liquid loops to test ATS products under real-world conditions.

ATS Labs

ATS engineer Reza Azizian (right) works with intern Vladislav Blyakhman on a liquid cooling loop in the lab. (Advanced Thermal Solutions, Inc.)

The labs at ATS are up to even the toughest electronics cooling challenges that the company’s global customers present. Thanks to its extensive lab facilities, ATS has provided thousands of satisfied customers with the state-of-the-art thermal solutions that they demand.

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

What are the benefits of using Pin Fin Heat Sinks in thermal management of electronics

Engineers tasked with designing modern electronics face a number of issues. Expectations are for more functionality, more power, and more components in ever-smaller packages but also with quick turnaround for production and staying within tight budget parameters.

Thermal management is a critical aspect of the design process and, as demand for component-density and miniaturization continues to increase, engineers need cooling solutions that fit into small spaces, will not cause project cost overruns, and will provide the best heat transfer possible for today’s modern,  processors.

Heat sinks and convection cooling remain the go-to solutions for most systems and high-efficiency Pin Fin heat sinks are designed to meet the requirements of modern electronics cooling with little extra cost added. In particular, the pin fin heat sink geometry is designed to provide increased surface area for heat transfer, low thermal resistance from base to fins at high airflow (200-plus LFM), and work in environments where the direction of airflow is ambiguous.

Pin Fin Heat Sinks

Pin fin heat sinks from Advanced Thermal Solutions, Inc. (ATS). Pin fin heat sinks provide low thermal resistance at high LFM. (Advanced Thermal Solutions, Inc.)

How does the Pin Fin geometry work?

Barry Dagan, an engineer at Cool Innovations, Inc., wrote a piece for New Electronics in 2009 that explained how the pin fin structure uses the ambient airflow to enhance its thermal performance. [1]

“Any heat sink removes heat by ‘breaking’ the boundary layers of still air that are wrapped around its surface because still air is a very good thermal insulator,” Dagan explained. “The boundary layers are broken by accelerating the flow of air into the heat sink – either using fans and forced airflow or via the chimney effect. In either case, the faster the airstream, the more likely the boundary layers are to break and the more effective the heat sink will be.”

He added, “The round, aerodynamic pin design reduces resistance to surrounding airstreams that enter the pin array, while simultaneously increasing air turbulence. The omnidirectional pin configuration, which allows air to enter and exit the heat sink in any direction, exposes the heat sink to the fastest possible air speed.”

In an earlier article for EE Times, Dagan also noted that the pin fin geometry “allows for a high degree of customization.” Engineers can make adjustments to the overall height, pin height, base thickness, footprint, pin diameter, and pin density to find an optimal cooling solution for their particular project. [2]

“Pin fins can also be catered for situations where both footprint and height are restricted,” Dagan wrote. “For example, the pin fin technology enables the design of heat sinks with a footprint of half an inch squared and a total height as low as 0.15 in.”

A study conducted by Younghwan Joo and Sung Jin Kim that was published in the International Journal of Heat and Mass Transfer indicated that the heat dissipation per mass of optimized pin fin heat sinks was greater than optimized plate-fin heat sinks in most applications. [3]

Pin Fin Heat Sinks

Pin Fin heat sinks on a PCB. (Advanced Thermal Solutions, Inc.)

In a comparison of heat sinks conducted at Advanced Thermal Solutions, Inc. (ATS) and published in Qpedia Thermal eMagazine, a 33-mm tall elliptical pin fin heat sink under forced convection had the lowest thermal resistance of the 10 heat sinks that were tested. [4]

The ATS family of pin fin heat sinks, made from extruded aluminum, range in sizes from 10 mm by 10 mm to 60 mm by 60 mm. Heights range from 2-25 mm. Through testing in ATS wind tunnels, the pin fin heat sinks demonstrated thermal resistance as low as 2.5°C/W and added little weight to the board. [5]

How are pin fin heat sinks attached to a board?

Pin fin heat sinks are versatile and can be attached to a variety of component packages, including BGA, QFP, LCC, LGA, CLCC, TSOP, DIP, LQFP, and many others. Because pin fin heat sinks are lightweight, standard thermal tape or epoxy can be used to securely attach them to components.

In addition, pin fin heat sinks work with mechanical attachments such as z-clips and ATS maxiGRIPTM or superGRIPTM, which are two-component attachment systems that provide secure hold without damaging the PCB and only minimal addition to the component footprint.

Pin Fin Heat Sinks

Pin fin heat sinks attached to a PCB with ATS maxiGRIP heat sink attachment system. (Advanced Thermal Solutions, Inc.)

How do pin fin heat sinks provide cost savings?

In his article for EE Times, Dagan explained, “Pin fin technology provides cost-effective heat sink solutions for medium and high-volume applications due to low associated tooling charges and minimal waste of raw materials.” [2]

For example, the ATS family of standard and custom pin fin heat sinks are all available for less than $2.00, with the vast majority of heat sinks available for less than a dollar. This means that engineers can find high-efficiency heat sinks and save money in the budget, which can be put to other design considerations, such as higher-powered fans to increase airflow, better heat sinks attachments, or additional chips and other board components. [5]

This is particularly beneficial for the growing maker market, which is working on new technology or enhancing current technology but generally with far smaller budgets than traditional OEM.

A 2012 article from The Economist, entitled “A Third Industrial Revolution,” discussed the impact of additive manufacturing techniques and how it was now possible to make parts through processes like 3-D printing that are cheaper and faster than traditional methods. According to the article, this will not just affect large manufacturers but also trickles down to a community of makers and smaller companies, what the article labeled “social manufacturing.” [6]

The article added, “As manufacturing goes digital, a third great change is now gathering pace. It will allow things to be made economically in much smaller numbers, more flexibly and with a much lower input of labour, thanks to new materials, completely new processes such as 3D printing, easy-to-use robots and new collaborative manufacturing services available online. The wheel is almost coming full circle, turning away from mass manufacturing and towards much more individualised production.”

Pin Fin Heat Sinks

Pin fin heat sinks provide cost-effective cooling solutions for small manufacturers and the maker market. (Advanced Thermal Solutions, Inc.)

A study, also from 2012, from MAKE magazine and Intel surveyed the maker community to get data about the (self-proclaimed) hobbyists, builders, tinkerers, and engineers. Out of the total respondents, 79 percent said that they worked in hardware and software, with electronics in second place at more than 60 percent. Thirty-four percent of respondents said that they were involved in making products for income and 19 percent of the total said that they paid for projects with outside funding. [7]

Crowdfunding can only take a project so far and for makers trying to earn money from designs, it is crucial to find cost-effective solutions both to ensure a project comes in under budget and to maximize profits from the sale of the design.

Pin fin heat sinks can be added at low-cost and provide the necessary thermal performance to push a design process along. For the maker market and its (at times) limited resources, high-efficiency pin fin heat sinks provide thermal performance on a budget with the versatility to fit into a variety of systems and designs.

[1] http://www.newelectronics.co.uk/electronics-technology/pin-fin-heat-sinks-point-the-way-to-more-efficient-cooling/18641/
[2] http://www.eetimes.com/document.asp?doc_id=1204099
[3] Younghwan Joo and Sung Jin Kim, “Comparison of thermal performance between plate-fin and pin-fin heat sinks in natural convection,” International Journal of Heat and Mass Transfer, April 2015, 345-356.
[4] https://www.qats.com/cms/wp-content/uploads/2014/03/HowAirVelocityAffects_Qpedia08.pdf
[5] https://www.qats.com/News-Room/Press-Releases-Content/1184.aspx
[6] http://www.economist.com/node/21552901
[7] http://www.nyu.edu/social-entrepreneurship/speaker_series/pdf/Maker%20Market%20Study%20FINAL.pdf

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

New Benchtop Wind Tunnel Tests Boards and Components at Elevated Temperatures

The CLWT-115 research quality, closed loop wind tunnel from ATS provides a convenient, accurate system for thermally characterizing PCBs and individual components at controlled temperatures from ambient to 85°C.

Advanced Thermal Solutions, ATS has introduced the CLWT-115 wind tunnel which allows engineers to evaluate the effects of elevated temperatures on component and PCB response and reliability. The new research quality, closed loop wind tunnel provides a convenient, accurate system for thermally characterizing PCBs and individual components at controlled temperatures from ambient to 85°C.

The CLWT-115 wind tunnel produces high quality, low turbulence air flows of up to 5 m/s (1000 ft/min). When customized, it can generate flows up to 50 m/s (10,000 ft/min) using optionally available orifice plates. The clear Lexan test section lets the user view the test specimen and allows for flow visualization.

Unlike open loop wind tunnels, the CLWT-115 recirculates internal air. This allows the system heater to quickly warm the air to a specific temperature. The testing of boards and components in hot air is a requirement in some NEBS and other standards. The precise controls and temperature range of the CLWT-115 wind tunnel allows its use for testing heat sink performance and for calibrating air and temperature sensors.

The complete wind tunnel fits on most lab benches and is powered from standard AC outlets. It has a smaller footprint than traditional, closed loop wind tunnels or environmental test chambers.

The wind tunnel’s test section can be accessed from the top door or sides for mounting and repositioning of boards, components and sensors. Internal rail guides provide an easy mechanism to install test specimens of different sizes (e.g., PCB, heat sink).

Instrument ports (6) are provided in the side walls of the test section for placing temperature and velocity sensors such as thermocouples, Pitot tubes and hotwire anemometers.

For more information about the CLWT-115 benchtop wind tunnel, visit Qats.com or call 1-781-949-2522.