March 2010

Interview with Amanda Hartnett, applications engineer with Indium Corp.
Indium Corp. applications engineer Amanda Hartnett recently discussed with Thermal News her knowledge of metal thermal interface materials and their potential applications and benefits.

What differentiates metal thermal interface materials from other interface materials?
I spend an extensive amount of time studying and testing the properties of metal thermal interface materials as well as other thermal interface materials, primarily polymer-based. They each have applications which they are best suited for, but the metal thermal interface materials stand in a category of their own with regard to their thermal performance.

Click here to read the full interview.

IRC’s Current Sense Resistors’ Flameproof Alloy, Open-Air Design Prevents Thermal Damage
For power electronics design engineers looking for high current devices capable of providing current-sense and surge protection functions in high temperature environments, TT electronics IRC offers a series of open-air current sense resistors. The OARS-3 Series surface-mount, metal-alloy strip resistors feature a flameproof, open-air design that elevates the device’s “hot spot” abovethe PC board, where heat can be dissipated to ambient air instead of to adjacent thermally-sensitive components. The design also gives the resistors thermal temperature cycling performance.

“The OARS-3 Series resistors feature a heavy-gauge alloy resistive element with welded copper terminations,” said IRC Application Engineer Bryan Yarborough. “Combined with its unique curved shape, these features give the resistor flexibility to virtually eliminatethe shearing force to the solder joint caused by the differences in thermal expansion between the PC board and the device. Unlike flat chips, these open-air resistors minimize the stress on their solder connections to the PC board, resulting in significantly better long-term solder joint reliability. The OARS-3 Series devices will provide a 3-watt rating in the same industry-standard 2512 footprint as a 1-watt flat chip resistor.”

The resistors’ ability to operate reliably under elevated temperature conditions makes them ideal for computer power supplies, high-reliability server equipment, and automotive under-hood applications.

The OARS-3 Series resistor performs at 3 watts; however, testing conducted by IRC engineers demonstrate that the resistor is capable of handling higher power levels without forced air depending on system thermal design. Testing at 4 watts reveals that, although the “hot spot” temperature can reach an excess of 230 °C when the resistor is running at full power, the solder joint remains at 110 °C or below.

The OARS-3 Series resistors are nominally rated for 3 W at 70 °C, with a resistance range from 2 mΩ to 15 mΩ and tolerances to ±1 percent. Inductance values are less than 10 nanohenries, with operating temperature ranging from -40 °C to 125 °C. RoHS-compliant and zero ohm jumper versions are also available. IRC will also produce devices outside these specifications to meet customer requirements.

Typical pricing for the OARS-3 Series resistors is approximately $0.86 each in minimum order quantities of 1900 pieces. Lead time is from stock to 14 weeks.

PA&E Announces New Ceramic Sealed Hermetic Windows
PA&E is now using its patented ceramic-to-metal sealing technology to manufacture hermetically sealed windows for optical, laser and infrared applications. The unique bonding properties and polycrystalline structure of PA&E’s Kryoflex material now allow the company to produce sight or wave-guide windows that maintain the highest levels of hermetic integrity under the extreme environmental conditions. This new product is well-suited for space or defense-related LADAR, laser designation and acquisition systems and medical endoscopes.

PA&E’s ceramic-sealed hermetic windows offer engineers additional advantages beyond high hermetic performance. Because Kryoflex seals at relatively low temperatures, they can now choose from a variety of optical glasses such as sapphire, quartz and BK10. These new windows are also designed to be laser-welded to a range of metals, including aluminum, titanium and iron/nickel alloys, for additional flexibility.

Windows produced with this new process are durable and reliable because a key point of failure, solder joint fatigue, is eliminated. They provide a leak rate equal to or less than 1X10-9 cc/sec helium at 1 atmospheric differential pressure, even when subjected to extreme thermal and mechanical shock and, in medical applications, will maintain integrity after repeated autoclave sterilization.

Unlike solder- or braze-sealed windows, PA&E’s ceramic-sealed hermetic windows do not require metallization. Eliminating this step can reduce costs and processing time and allows anti-reflective coatings to be applied after the sealing process, ensuring that the critical A/R coating is not impacted by subsequent processing.

Industrial Wireless Temperature Transmitter Powered by Heat
Wireless sensors are rather inexpensive and can be deployed almost anywhere. Deploying more sensors would lead to safer and more efficient process control, as well as reduced maintenance cost, if cost and effort of battery maintenance could be obviated.

Energy harvesting is used by the ABB R&D Centers Ladenburg, Germany and Daettwil, Switzerland, and Micropelt, Freiburg, Germany to replace the battery with an unlimited, green, sustainable, maintenance-free power supply. As the result of a joint development project, an ABB WirelessHART temperature transmitter has been equipped with a thermal energy harvesting unit containing two Micropelt Thermogenerators MPG-D651 with a footprint of 6 mm² each. A temperature gradient of 30 °C between the sensed medium and ambient air is sufficient to fully cover the power demand of the mesh-networked wireless instrument. Dr. Marco Ulrich, ABB’s project leader, said he sees a major breakthrough.

“Wireless instruments provide for a much more flexible and comprehensive use of sensors at much reduced total cost, particularly under difficult conditions,” Ulrich said. “However, none of our customers can accept having to exchange batteries with hundreds or thousands of instruments on a regular basis. Our technology demonstrator proves the concept of large, complex sensor networks at a fraction of the previously accrued total cost of ownership.”

Dr. Joachim Nurnus, Micropelt’s CTO, agreed.

“We certainly save some hundreds of thousands of high power batteries, but far more important are all the additional sensing points which will help producing more energy-efficiently, optimize the utilization of process equipment, and shift to the highly cost-efficient condition-based maintenance,” Nurnus said. “We have only just begun to understand the enormous economical and ecological potential of ubiquitous wireless sensing. Now, we very much look forward to sharing this with our customers along with a host of other self-sustaining wireless demonstrators and prototypes at the upcoming sensors shows in Nuremberg, Germany, in May and Chicago, Ill., in June.”

Honeywell Announces New Thermal Management Materials for Portable Computing Devices
Honeywell Electronic Materials has announced a new printable thermal management material designed to help manage the tremendous heat produced by increasingly powerful semiconductors in portable computing devices such as laptops and netbooks.

The new material, Honeywell PCM45M-SP, builds on Electronic Materials’ existing line of thermal management materials. As semiconductors become more powerful and smaller, more heat is being generated in the confined spaces where semiconductors are packaged for end-use applications. This tremendous heat can damage the semiconductor or degrade its performance, and it can damage the device as well.

“Mobile computing devices such as laptops and netbooks are placing increased demands on thermal management materials to enable high performance and ensure a long lifespan,” said Tim Chen, packaging leader for Honeywell Electronic Materials. “To meet that challenge, we have combined our industry leading phase-change chemistry with an innovative formulation specifically designed for these types of mobile devices.”

In typical mobile computing applications, chip temperature rises steeply at start-up and remains high during operations. PCM45M-SP is designed to meet these specific thermal management requirements, delivering reliable power cycling performance where other thermal materials would typically fail.

PCM45M-SP can withstand more than 1,000 hours at 150 °C without degradation and more than 1,000 temperature cycles. The application is not limited to heat sink design, and the material may be applied to a component, heat sink or thermal spreader in any shape built into the printing screen. Additionally, the enhanced stability of this new material minimizes or eliminates the need for pre-mixing, conserving time and resources.

The PCM45M-SP phase change thermal interface consists of a sophisticated thermally conductive material with optimum filler size distribution to achieve maximum packing density compared with conventional phase change materials. PCM45M-SP changes phase at 45 °C to ensure maximum surface conformance.

Fujipoly Announces High-Performance Thermal Putty
Fujipoly has announced the availability of its highest performance thermal interface silicone putty. SARCON XR-Um-Al is a gap filler compound that has a putty-like consistency. This physical property contributes to the material’s extremely low contact and thermal resistance while maintaining a thermal conductivity of 17 watt/m-k.

SARCON XR-Um-Al is manufactured with a thin aluminum carrier film for customer-friendly application. The low adhesion aluminum barrier enables users to remove the carrier film after installation with no pull-out effect. This thermal interface material is available in sheets as large as 50 mm by 50mm with thicknesses ranging from 0.2 mm to 0.5 mm.

SARCON XR-Um-Al complies with UL 94 V-0 flame retardancy specifications and is most commonly used to transfer heat from between CPUs and semiconductors to close proximity heat sinks.

Lockheed Martin Orion Team Fabricates World’s Largest Heat Shield Structure
The Lockheed Martin-led team developing the Orion crew exploration vehicle has completed fabrication of the world’s largest heat shield structure. The shield is 5 meters (16.4 feet) in diameter and is critical to the protection of the spacecraft and its crew from the extreme temperatures experienced during re-entry. The work was completed at Lockheed Martin’s composite development facility in Denver, Colo.
The crew exploration vehicle is at the height of its development phase, which has spurred several new technologies and innovations such as a new high-temperature composite material system. The system was developed by the Lockheed Martin Orion thermal protection system team in partnership with TenCate Advanced Composites, a leading supplier of aerospace thermoset and thermoplastic prepregs. TenCate’s composite materials are used in commercial aircraft, radomes, satellites, general aviation, oil and gas, medical and high-end industrial applications.

“In addition to the technology advancement, we achieved a $10 million cost savings and improved the project schedule by 12 months through the innovative tooling, materials and fabrication processes the team put into action,” said Cleon Lacefield, Lockheed Martin vice president and Orion program manager.

The new resin system was developed over an 18-month period during which thousands of coupons were tested in extreme environments that simulated a ballistic re-entry from a lunar mission. The team verified that the thermal insulator on the outside of the composite material can be thinner due to the higher temperature capability, resulting in improved mass optimization of the Orion spacecraft. The new resin system enables much simpler and more efficient manufacturing techniques compared with other high temperature resin systems. This resin system has the potential to be used in a wide range of commercial applications including aircraft, automobiles, launch vehicles, payload fairings, and re-entry vehicles.

The expansive heat shield will be applied to the Orion ground test article, which is the first full-sized, flight-like test article for Orion being built at the Michoud Assembly Facility in New Orleans, La. The ground test article is designed to serve as a production pathfinder to validate the flight vehicle production processes and tools. When completed, the crew module will be tested on the ground in equivalent flight-like environments, including static vibration, acoustics and water landing loads. This early high fidelity testing is necessary to correlate sizing models for all subsystems on the vehicle.

Lockheed Martin is the prime contractor to NASA for the Orion crew exploration vehicle. The Lockheed Martin Orion Project office is based in Houston, Texas, near NASA’s Johnson Space Center. The team includes subcontractors Aerojet, Alliant Techsystems (ATK), Hamilton Sundstrand, Honeywell, Orbital Sciences Corporation and United Space Alliance, as well as expansive network of minor subcontractors and small businesses working at 88 facilities in 28 states across the country.

POINTek Releases 10,000th Athermal AWG at New Plant in Seoul
POINTek has announced success in ramping up its flagship product, athermal Arrayed Waveguide (AWG), in its new production facility in Seoul, South Korea. POINTek’s CEO, Dr. TH Rhee, commented that relocation of its production plant to Seoul was necessary to meet growing demand for athermal AWGs worldwide, including Korea. The ramp-up facility expansion makes it possible to produce more than 1,000 units per month.

This is in tune with anticipated growth in WDM-PON and FTTH-driven global recognition of athermal AWGs for broadband access optical multiplexer/de-multiplexer device usage, according to POINTek’s Chief Marketing Officer, Dr. Donald P. Yu, at the corporate marketing office in Los Angeles, Calif.

“To date, we have seen more demand in carriers’ transport system improvement and network system vendors’ equipment upgrades at Tier-one optical network installations and long-haul transport,” Yu said.

Commemorating the 10,000th AWG with Dr. Hyng Jae Lee, POINTek’s CTO, and production staff, Dr. Rhee has expressed extended application of athermal AWGs in DWDM-based broadband markets, and he plans to unveil new integrated optical modules based on POINTek’s core product, athermal AWG, at the forthcoming OFC/NFOEC Exposition in San Diego, Calif., March 23 to 25.

With an eye toward replacing traditional thermal AWG markets with cost-effective athermal AWG, POINTek’s athermal AWG is designed to take advantage of high performance in terms of environmental reliability and athermal characteristics. The “athermalization” innovation in packaging process differentiates POINTek’s athermal AWG from the conventional AWG. At present, POINTek manufactures many types of athermal AWG, ranging from 16-channel/200GHz to 88-channel/50GHz. POINTek can tailor each athermal AWG per customer’s specifications in terms of channel spacing, type (flat top, semi-flat top, and Gaussian) and other optical parameters.

Southwall to Provide Technology in Super Insulating Windows for Empire State Building Energy Efficiency Retrofit Projec
Southwall Technologies, Inc., a producer of energy-saving films and glass products, announced today that its Heat Mirror film technology was selected to dramatically boost the energy efficiency of the more than 6,500 hundred windows being upgraded as part of the Empire State Building energy retrofit project.

The existing insulating glass in the building will be removed from the frames and reused by suspending Heat Mirror film between the two panes to create a pair of super insulating cavities that increase the thermal performance by up to four times, improving the R-value from R-2 to R-8 while also reducing the solar heat gain by 50 percent..

“We are pleased that one of Southwall’s technology licensees, Serious Materials, was awarded this landmark project and is relying on the proven performance of our Heat Mirror film technology as the key enabler for their super insulating windows,” said Bruce Lang, Southwall’s vice president of marketing. “It will become a model solution for future building retrofit projects worldwide.”

The upgraded windows are expected to deliver more than $400,000 in savings per year. The window upgrade is one part of an integrated project that is expected to reduce energy use by 38 percent, save $4.4 million per year in energy costs and save a minimum of 105,000 metric tons of carbon dioxide over the next 15 years. Johnson Controls is overseeing the full retrofit project with a team of energy efficiency experts including the Clinton Climate Initiative, Jones Lang LaSalle and Rocky Mountain Institute.

“Windows have been traditionally overlooked in the energy efficiency discussion, when in fact, they are low-hanging fruit that can make a real impact today,” stated Dennis Capovilla, Southwall’s president and CEO. “Increasing customer demand to save energy and reduce carbon emissions is driving the need for a new generation of windows that are proven, available, and insulate like walls. That’s what Heat Mirror technology enables - walls that you can see through.”

Heat Mirror insulating glass is a multi-cavity solution that suspends one or more low-emissivity and solar-reflective Heat Mirror films inside of an insulating glass unit to create two, three or four insulating cavities without adding weight. Heat Mirror suspended film technology combines film-based and glass-based technologies to create “super glass” with center-of-glass insulating performance ranging from R-4 to R-20 while minimizing solar heat gain and blocking UV radiation.

The March 12 deadline for submitting abstracts has been extended. Abstracts are now being accepted on a first-come, first-serve basis. Submit yours as soon as possible to be considered for inclusion in the conference.

For more information on submitting an abstract, please visit our Call for Presentations page.

Thermal Management and Technology Symposium 2010 provides an excellent forum to discuss new developments in technology, market conditions and end-user requirements that are driving innovation, capabilities and features, application trends and performance improvements today and in the future. Attendees will include design engineers, system engineers, process engineers, material scientists and engineers, CTOs and R&D managers with organizations in industries and markets whose products, operations and services depend upon sophisticated and precise control of thermal properties and states.

Full-conference registration fees will be waived for all confirmed speakers.

March
23-25 CTIA Wireless, Las Vegas, Nev.

April
6- 9 IPC APEX Expo 2009, Las Vegas, Nev.
10-15 NAB, Las Vegas, Nev.
13-15 SAE World Congress, Detroit, Mich.
26-29 Embedded Systems Conference, San Jose, Calif., San Jose, Calif.

May
11-13 EDS, Las Vegas, Nev.
11-14 National Manufacturing Week, Sydney, Australia
12-14 LightFair, Las Vegas, Nev.
23-28 SID Display Week, Seattle, Wash.
25-29 Interop, Las Vegas, Nev.

Electronic Components and Technology Conference
June 1-4, 2010
Las Vegas, Nev.

The premier international packaging and components conference, the Electronic Components and Technology Conference (ECTC), has published its Advanced Program. It includes 40 technical sessions (six of which are dedicated to 3D Si TSV fabrication, bonding, and processing issues), 16 CEU-approved professional development courses, and a technology corner with more than 70 exhibitors. There are also four special/invited sessions covering upcoming technologies such as packaging of medical devices, very fine pitch bumping, RFID technology, and the evolution of Mobile processing architecture.

The 60th ECTC will be held June 1-4, 2010 at the Paris Las Vegas Hotel, Las Vegas, Nevada, USA. For more information and to register, visit www.ectc.net.

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