Tag Archives: superGRIP

Picking the Right Heat Sink Attachment to Avoid Costly PCB Damage

Posted on July 18, 2017 by | 8 comments

The design of a printed circuit board (PCB) is a complicated process that requires engineers to consider a number of different issues before the board is ready to move beyond prototype and into production. Engineers must think about the physical constraints of a board on component size and placement, the electrical interaction between components, the signal loss through wires and traces, and the thermal management of each component and the system as a whole. [1]

Heat Sink Attachment

ATS maxiFLOW heat sink with superGRIP attachment on a PCB. (Advanced Thermal Solutions, Inc.)

With all of that to consider, it is no wonder that many designs go through several iterations before moving into the production stage. Since the process is already complex and there is a certain amount of trial-and-error in designing a PCB, engineers will look for ways to avoid unnecessary rework that will add significant cost to the project in terms of both time and money.

As noted in a previous article, the type of heat sink attachment technology that an engineer chooses will impact the ease with which a design can be reworked and the amount of damage to the board that will be caused if a change needs to be made.

Push pins, threaded standoffs and z-clips require holes or anchors be drilled into a board, which leaves permanent damage if a component needs to be moved to a new location and could also impact signal routing. There is even the possibility of a short in installation, which also would damage the board. [2]

Non-mechanical attachments such as thermally conductive tape and epoxy are not guaranteed to provide the optimal thermal management because there is “risk of die damage and poor thermal performance due to uneven heat sink placement,” according to a case study from the Altera Corporation. [3]

The case study also said that thermal tape and epoxy have “high risk of damaging the device or PCB” when compared to mechanical attachment technology coupled with thermal interface material (TIM) or phase change material (PCM). In fact, to remove a heat sink attached with epoxy requires an even temperature of 115-120°C.

As the video below shows, removing thermal tape from a heat sink (even one that is not attached to a board) requires a lot of work and tools. If the heat sink is attached to a component, the process to remove it could damage the board or other devices in the vicinity:

A recent chart from NEMI (National Electronics Manufacturing Initiative) indicated that the cost of assembly can be very high per I/O (input/output) on the PCB – considering some of the new BGAs have hundreds of I/O and there are dozens of BGAs on the board, the cost can be prohibitively expensive to put together a board irrespective of the product sector. [4] Obviously, full reworks necessitated by the use of damaging heat sink attachments raise those costs exponentially.

Heat Sink Attachment

Board assembly roadmap from NEMI showing the conversion costs by product sector. [4]

Advanced Thermal Solutions, Inc. (ATS) has created a mechanical attachment technology that makes rework easy and allows engineers to make changes to the design without damaging the PCB or the components. superGRIP™ is a two-part attachment system with a plastic frame clip that fastens around the edge of the component and a metal spring clip that fits between the fins of the heat sink and quickly and easily attaches to the frame.

As the video below demonstrates, superGRIP™ can be installed and removed with common household tools and will provide a steady, firm pressure to ensure optimal thermal performance of the heat sink and the reliability of the device:

The advantage of superGRIP™ is not limited to its ease of use and the time and money that will be saved in reworking a PCB design. The pressure strength and security of the superGRIP™ attachment system allows the use of high-performance phase change materials that can improve heat transfer by as much as 20 times over standard thermal tapes. [4]

superGRIP™ comes with Chomerics Thermflow T-766, a foil PCM with a thickness of 0.0035 millimeters that has an operating range of -55°C to 125°C. According to Chomerics, the T-766 and other traditional non-silicone thermal interface pads “completely fill interfacial air gaps and voids. They also displace entrapped air between power dissipating electronic components. Phase-change materials are designed to maximize heat sink performance and improve component reliability.” [5]

Chomerics added, “Upon reaching the required melt temperature, the pad will fully change phase and attain minimum bond-line thickness (MBLT) – less than 0.001 inch or 0.0254 mm, and maximum surface wetting. This results in practically no thermal contact resistance due to a very small thermal resistance path.”

The combination of frame and spring clip provides uniform force over the heat sink and ensures no movement to optimize the impact of the PCM, while not damaging the solder holding the BGA component in place on the board. ATS engineers designed the attachment technology so that the in-plane and normal forces of both the frame and the spring clip hold the heat sink without stressing the solder even through NEBS (Network Equipment Building Systems) shock and vibration testing. [6]

Save time, save money, and avoid unnecessary headaches during the design phase by using ATS superGRIP™ technology.

References
[1] http://www.electronicdesign.com/boards/11-myths-about-pcb-layout
[2] “How the maxiGRIP™ attachment system impacts component mechanical behavior,” Qpedia Thermal eMagazine], May 2008.
[3] https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/literature/an/an657.pdf
[4] http://thor.inemi.org/webdownload/newsroom/Articles/CA0599.pdf
[5] https://www.qats.com/cpanel/UploadedPdf/ATS_superGRIP_Launch_Release_
FINAL_with_Photo_0427092.pdf
[6] http://vendor.parker.com/852568C80043FA7A/468ea5de5ac341d385257d39005641c7/
9A63F6EE5B922F278525787600620419/$FILE/Phase_Change_Excerpt-5-08.pdf
[7] “How the maxiGRIP™ attachment system impacts component mechanical behavior,” Qpedia Thermal eMagazine, May 2008.

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.

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Choosing the Right Heat Sink Attachment for Densely Populated PCB

Posted on July 12, 2017 by | 3 comments

In 1965, Fairchild Semiconductor Director of R&D and soon to be Intel co-founder Gordon Moore wrote “The Future of Integrated Electronics,” which was intended as an internal paper to define the most cost-effective number of components per integrated circuit. As he looked ahead to the next decade, Moore argued that the number of components per chip would double every year.

The paper was edited and published by Electronics in 1965 as “Cramming More Components onto Integrated Circuits”. Ten years later, Moore, then with Intel, spoke at the IEEE International Electron Devices Meeting and showed that his initial prediction was correct and estimated that the rate of increase would slow to “a doubling every two years, rather than one.”

Heat Sink Attachment

superGRIP heat sink attachment technology offer minimal addition to component footprint on densely packed PCB. (Advanced Thermal Solutions, Inc.)

This prediction has now become widely known as Moore’s law. It has become a tenet of the electronics community and continues to propel the industry forward at a time when the number of transistors on a chip (which was around 65,000 in 1975) now exceeds one billion. [1]

These high-powered components are common on printed circuit boards (PCB) in every day electronics from mobile devices to computers to automobiles. Recently, the Defense Advanced Research Program Agency (DARPA) announced that it will spend $200 million on the Electronics Resurgence Initiative to seek new materials and manufacturing techniques in expectation that Moore’s law will come to a natural end. [2]

Not only are the components themselves getting higher-powered, but increased demand for functionality in ever-smaller packages has meant that these components are increasingly being squeezed into tighter areas. A 2012 article on Tech Design Forums, based on information from Mentor Graphics’ Technology Leadership Awards, indicated that while PCB size had been “relatively constant,” the “average number of components has quadrupled in 15 years.” [3]

As the forum noted, “Despite attempts by IC (integrated circuit) suppliers to cut power dissipation, as IC speeds and densities increase so does the heat they dissipate. And putting these ICs into smaller and smaller form factors compounds the problem. This causes significant thermal management challenges that must be met at the IC package, PCB and system levels.”

OCM Manufacturing, a low- to mid-volume manufacturer of electronics products, offered a chart that detailed standard spacing of components on a PCB, but also added, “With that said, there are no hard and fast rules for component spacing. Tightly packed components may have very good yield and problems may arise only during rework.” [4]

Heat Sink Attachment

Match each component in the rows with whatever it’s adjacent to in the columns to see the preferred and minimum spacing between those two components, in millimeters. [4] (OCM Manufacturing)

Of course, all of that power will inevitably lead to increased heat across the system. Coupled with the decrease in space between components, which puts constraints on the amount of airflow across a component and leads to heat from one chip being passed on to the next, thermal management is a critical aspect of PCB design to an even greater extent than before. [5]

Heat sinks remain the most cost-effective method for cooling chips. The benefits of heat sinks, the thermal impact of different materials, and the development of new fin geometries are all discussed in depth elsewhere on this blog, but this article asks, “What is the best way to attach heat sinks, especially in a component-dense environment?”

As Dr. Kaveh Azar, founder and CEO of Advanced Thermal Solutions, Inc. (ATS), wrote in ECN Magazine, “An engineer starting the process of thermal management must first determine the cooling needed and then consider the mechanical aspects of attaching the heat sink.” [6]

He added, “The thermal consideration is foremost on our decision tree. Once we have resolved the cooling issue, including the heat sink size and the type of thermal interface material (TIM) needed, we need to ask the question of how this heat sink will be attached to the device or the PCB.”

There are several options for design engineers to consider, but each comes with its own set of challenges. Thermal tape and thermal epoxies [7] would obviously add nothing to the existing component footprint, but tape has proven better for low-powered chips and epoxies require time to cure and are essentially permanent, making potential rework more time-consuming and costly.

Push pins, threaded standoffs and z-clips are mechanical attachment technologies that are common in the electronics industry but all require expanded footprints as well as holes or anchors in the PCB, which may not be available on high-density boards. Holes and anchors also make signal routing more difficult in the design phase and there is a possibility of a standoff or solder anchor causing a short during installation that could result in damage to the board. [8]

To meet this need, ATS developed superGRIP™. The two-part attachment system features a plastic frame clip that fastens securely around the perimeter of the component and a metal spring clip that slips through the fins of a heat sink and locks to the frame clip on both ends. [9]

The system is designed to need minimal space around the component. [10] The frame clip is made of a plastic resin that allows it to be very thin but also very strong, which was demonstrated during shock and vibration testing. The interior frame profile locks securely around the bottom edge and sides of the component package. The horseshoe tabs secure the clip to ensure the proper pressure on the heat sink.

The following chart shows the superGRIP™ clearance guidelines, although custom options are available and may be needed depending on the design:

superGRIP

The required board keep-out region for ATS superGRIP heat sink attachment technology. (Advanced Thermal Solutions, Inc.)

superGRIP™ was also designed and tested to ensure maximum airflow through the heat sink. In a tightly-packed system where airflow is at a premium, superGRIP™ provides the necessary attachment security with only minimal impact on the flow. In addition, the plastic used in the frame clip stays cool in high-heat environments, rather than adding fuel to a potentially combustible situation.

superGRIP

CFD simulations with ATS superGRIP attachment demonstrating its minimal impact on airflow across a system. (Advanced Thermal Solutions, Inc.)

Unlike other attachment technologies, superGRIP™ also requires no separate tooling and can be installed or released with a common tool such as a screwdriver. [11] This makes any potential rework easier. It is important to note the direction of the airflow when placing a heat sink, so it must also be considered when placing the frame clip as well.

References
[1] http://www.computerhistory.org/siliconengine/moores-law-predicts-the-future-of-integrated-circuits/
[2] http://www.eetimes.com/document.asp?doc_id=1331974 and https://www.darpa.mil/news-events/2017-06-01
[3] http://www.techdesignforums.com/practice/technique/overcoming-increasing-pcb-complexity-with-automation/
[4] http://ocmmanufacturing.com/resources/resource/dfm-tip-spacing-components-on-a-pcb/
[5] http://www.electronicdesign.com/embedded/engineer-s-guide-high-quality-pcb-design
[6] https://www.ecnmag.com/article/2011/09/know-your-choices-mounting-heat-sinks-hot-components
[7] https://www.masterbond.com/industries/heat-sink-attachment
[8] “How the maxiGRIP™ attachment system impacts component mechanical behavior,” Qpedia Thermal eMagazine, May 2008.
[9] https://www.qats.com/cpanel/UploadedPdf/ATS_superGRIP_Launch_Release_FINAL_with_Photo_0427092.pdf
[10] https://www.qats.com/cms/wp-content/uploads/2013/12/superGRIP-Clearance-Guidelines1.pdf
[11] https://www.qats.com/cms/wp-content/uploads/2013/12/superGRIP-Installation-Guidelines.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.

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Posted in Heat Sink Attach, Heat Sinks

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#WeCoverTheBoard: ATS Has Thermal Solutions to Cover the Whole Board

Posted on February 16, 2017 by | 6 comments
We Cover The Board

Advanced Thermal Solutions, Inc. (ATS) has an extensive line of heat sinks and board level thermal solutions that allow ATS engineers to work with industry-leading components and solve the industry’s toughest thermal challenges. (Advanced Thermal Solutions, Inc.)

Advanced Thermal Solutions, Inc. (ATS) has an extensive product line of innovative, off-the-shelf and custom heat sinks and attachments that provides the broadest range of designs to meet the demanding thermal challenges presented by today’s high-powered electronics. Led by its patented maxiFLOW™, which provides the highest thermal performance for physical volume it occupies compared to other heat sinks on the market, ATS has a solution to meet any thermal problem.

In addition, ATS engineers have world-renowned expertise in thermal management and are capable of designing liquid and air cooling solutions using heat sinks, heat pipes, heat exchangers, fans, and cold plates. ATS has more than two decades of solving the industry’s toughest thermal challenges and have a proven record of success in handling the industry’s leading components.

From the latest generation of Intel processors to Altera’s high-powered Stratix FPGA to Qualcomm’s ARM processors to Texas Instruments, Nvidia, NXP, Cavium, and many more, ATS has the experience, the analytical capability, and the products to provide you with the necessary thermal management.

Board Level Solutions

maxiFLOW™ – maxiFLOW™ heat sink design provides the highest thermal performance for the physical volume that it occupies as compared to other heat sink designs. maxiFLOW™ heat sinks are ideally suited to meet the thermal requirements of a broad range of electronics packages, including: BGA, QFP, LCC, LGA, CLCC, TSOP, DIPs and LQFP.

Straight Fin – ATS offers a large variety of high performance Straight fin heat sinks that can be used in many applications where the direction of the airflow is clearly defined. The straight fin heat sink can be utilized in areas where the maxiFLOW™ flair-fanned cannot be used, providing an excellent alternative for cooling thermally sensitive devices.

Cross-Cut – Electronics packages are numerous and range from BGA, QFP, LCC, LGA, CLCC, TSOP, DIPs, LQFP and many others. ATS offers a large variety of cross cut heat sinks that can be used in a variety of applications where the direction of the airflow is ambiguous. The cross cut allow for the heat sink to receive air from any direction.

Pin Fin – Electronics packages are numerous and range from BGA, QFP, LCC, LGA, CLCC, TSOP, DIPs, LQFP and many others. ATS offers a large variety of cross cut heat sinks that can be used in a variety of applications where the direction of the airflow is ambiguous. The cross cut tape on allow for the heat sink to receive air from any direction and can be easily attached to the device by a thermally conductive tape.

fanSINK™ – In many electronic systems, such as telecomm and datacom chassis, or 1U, 2U servers and blades, the system air flow rate is not adequate for cooling of high power devices. Therefore, additional air flow introduced at the device level is required. ATS offers a large family of fanSINK™ products for applications where FPGA or ASICs in BGA packages are deployed. ThefanSINK™ can be either clipped on to the device by maxiGRIP™ or superGRIP™ heat sink attachment technologies or taped on.

Power Brick – DC/DC power converters are an essential part of PCB design and their performance requires a stable temperature for optimum performance. ATS has produced a broad array of high performance power brick heat sinks, based off of the patented maxiFLOW™ design, to effectively cool DC/DC power converters and power modules deployed in a host of electronics applications. ATS’ power brick heat sinks are available in full, half, quarter and eighth packaging.

pushPIN™ – With over 108K different push pin heat sink assembly configurations, ATS offers the largest push pin heat sink offering in the market. Select from fine and ultra-fine pitch heat sinks designed for high velocity air flows and coarse pitch heat sinks for low velocity air flow conditions. Offered in straight fin, cross-cut and the ultra performance maxiFLOW™ fin geometries, ATS pushPIN™ heat sink line is suited to meet a wide variety of applications for components ranging in size from 25mm-70mm. Push pins are offered in brass and plastic and are packaged with different compression springs to achieve precise force required for secure attachment.

blueICE™ (Ultra Low Profile) – In many electronics systems, such as Telecomm, Datacomm, Biomedical equipment and others, card-to-card spacing is small, yet stringent thermal requirements remain the same. Electronics packages such as BGA, QFP, LCC, LGA, CLCC, TSOP, DIP, LQFP are commonly used with stringent thermal requirements in a tight space with limited airflow. Ultra low profile heat sinks offered by ATS range from 2 to 7mm in height and are ideally suited for tight-space application electronics since they offer the best thermal performance. Their thermal resistance is as low as 1.23° C/W within an air velocity of 600 ft/min.

Standard Board Level – ATS’ high quality, low cost, aluminum stamped heat sinks are ideal for low power thermal management solutions. The simple design and manufacturing of these heat sinks allows high volume manufacturing and reducing assembly costs. Stamped heat sinks are ideally used for TO packages and other power devices.

Extrusions – Aluminum extrusions are the most cost-effective solutions for the majority of electronic cooling applications. ATS offers a wide variety of aluminum profiles used for heat sink fabrication and other aluminum applications. Whether you are seeking a standard extrusion profile or the expertise from our design team to create a new and innovative profile, ATS has the capabilities and expertise to meet your requirements.

Heat Sink Attachments

superGRIP™ – superGRIP™ is a two component attachment system which quickly and securely mounts heat sinks to a wide range of components, without needing to drill holes in the PCB. superGRIP™ provides a strong, even attachment force with minimal space required around the components perimeter, making it ideal for densely populated PCBs. superGRIP™ is available with ATS maxiFLOW™ heat sink and straight fin heat sinks.

maxiGRIP™ – maxiGRIP™ is a unique, two component attachment system which quickly and securely mounts heat sinks to a wide range of components, without needing to drill holes in the PCB. The steady, even attachment force provided by maxiGRIP™ allows the heat sink and thermal interface material to achieve maximum thermal performance. maxiGRIP™ is available with ATS maxiFLOW™, straight fin, fanSINK™ and device specific heat sinks.

Thermal Tape – The interface material plays a pivotal role in transporting the heat from the component to the heat sink. The tape is applied to the base of the heat sink and then the heat sink is attached to the component. For tape to work well, proper cleaning of the component surface and the base of heat sink is required. Also, it is usually necessary to apply the tape with a certain amount of pressure.

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ARM Microprocessors and ATS superGRIP: Attached at the Clip

Posted on January 18, 2013 by | Leave a comment

Advanced Thermal Solutions, Inc., (ATS), has introduced a line of heat sinks compatible with the Sitara ARM Microprocessor family from Texas Instruments.

AM1707 from Texas Instruments

AM1707 from Texas Instruments

The Sitara ARM Microprocessors feature ARM Cortex-8 and ARM9 MPUs, which are used in a wide variety of Industrial, Medical, and Consumer Electronics applications.

The AM17x family consists of low-power ARM microprocessors that enable OEMs and ODMs to maximize product offerings by providing high processing performance life, advanced operating systems and rich user interfaces. Compatible operating systems include Neutrino, Integrity, Windows, Embedded CE, Linux, VXWorks and Android.

ATS patented maxiFLOW heat sinks with superGRIP clip attachment ensure long-term product reliability and maximum performance from the Sitara ARM Microprocessors. maxiFLOW high performance BGA heat sinks feature a low profile, spread fin array that maximizes surface area for more effective convection air cooling. The unique maxiFLOWTM design provides thermal performance that is 30-200% better than conventional heat sinks.

ATS' maxiFLOW Heat Sink with superGRIP Attachment

ATS’ maxiFLOW Heat Sink with superGRIP Attachment

maxiFLOW is available with pre-assembled phase change material, maxiGRIP clip attachments, and superGRIP clip attachments. The superGRIP attachment system features a plastic frame clip that fastens securely around the perimeter of a component and a metal spring clip that slips through a heat sinks fin field and locks securely to both ends of the plastic frame. The resulting superGRIP assembly applies steady even pressure to the component throughout the product lifecycle, improving thermal performance and long-term reliability. The ATS superGRIP heat sink attachment system permits the use of high performance phase changing thermal interface materials that improves heat transfer by as much as 20 times more than typical double-sided adhesive thermal tapes. It also allows for the heat sink to be detached and reattached without damaging the component or the PCB, an important feature for applications where PCB rework and ease of assembly and disassembly are important. The full range of ATS products compatible with Texas Instruments products can be viewed in the new heat sink selection tool on http://qats.com/Distributor/AE-Dist.php

To learn more about maxiFLOW heat sinks and the superGRIP clip attachment, please visit www.qats.com, email ats-hq@qats.com, or call 781-769-2800.

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