Nextreme Improves Thin Film Thermoelectric Material
Nextreme, a manufacturer of advanced thermoelectric components that address thermal management and power generation needs of the semiconductor, photonics, test-and-measurement and defense/aerospace industries, has enhanced its miniature embedded thermoelectric component (eTEC) material. The technology advancements have made it possible for researchers at Nextreme to consistently achieve temperature differentials of 55°C to 60ºC with eTECs at room temperature. Physically larger conventional thermoelectric technology typically produces 65ºC under the same conditions. Nextreme devices employ proprietary materials that are 5 to 15 um thick, which is about 100 times thinner than the typical 1 mm thick pellets used in conventional thermoelectric devices.
“It is remarkable that devices no thicker than a piece of paper can deliver this kind of performance,” said David Koester, VP of engineering at Nextreme. “This should have an immediate impact in photonics and other industries where a lack of an integrated cooling solution is limiting market penetration of various products.”
Nextreme’s eTECs are designed utilizing thin films that are small, thin, fast, efficient and reliable, adding as little as 100 microns (0.1 mm) of height to a heat spreader or package, which enables unobtrusive integration close to the heat source.
The eTEC’s ultra fast, millisecond response time rapidly cools or heats to maintain a precise temperature depending on the needs of the application. A typical device pumps a maximum heat flux of 150 W/cm2 with some designs delivering as much as 400 W/cm2 versus 10 to 20 W/cm2 for typical bulk TECs.
Prototypes for Nextreme’s eTEC are available for sampling and are expected fully qualified by the third quarter of 2007.
Jumbo-CelsiDot Excess Temperature Labels Are Easy to Read
Recently some associations responsible for industrial safety issues started to request excess temperature monitoring for electric motors, transmission gears and other mission critical parts used in chemical, energy and food processing industries. With detected exceeded temperature levels, preventive maintenance steps can be initiated.
Jumbo-CelsiDot temperature detectors are large-faced excess temperature recording labels. The Jumbo-CelsiDot 93ºC attached to the electric motor on the left side of the image has permanently turned from white to black, which is a sure sign that this location had exceeded the label‘s 93ºC temperature trigger level. An identical Jumbo-CelsiDot 93ºC label applied to the gear case to the right is still white. This is an undisputed sign that the temperature history on that location never reached or passed the 93ºC level.
These Jumbo-CelsiDot labels are available in 40 different levels within the range from 40ºC to 260ºC (105F to 550F) Labels are available in packages of 24 labels or rolls of 1,000 labels.
TC-LINK Wireless Thermocouple Node Now Has Six Thermocouple Channels
MicroStrain, Inc. recently released the latest version of its TC-LINK wireless thermocouple node, the TC-LINK-6CH, that features six thermocouple channels, an embedded cold junction compensation sensor and includes the option of adding a relative humidity sensor. The 24-bit delta-sigma A/D provides outstanding resolution over a wide temperature range.
The TC-LINK-6CH represents a reduction in the cost per channel. With the ability to transmit real-time data from multiple nodes to a single base station, or store up to 300,000 data points in on-board memory, the TC-LINK-6CH offers improved flexibility.
At a sample rate of one sample per minute monitoring all six thermocouple channels, MicroStrain’s patented low power circuit design sips an average 85 microamps from the internal battery, offering 10 months of continuous operation between recharge. With the optional use of external batteries, the TC-LINK can operate for more than 10 years between battery changes.
Applications include civil structures sensing for concrete maturation, industrial sensing networks for machine thermal management, food and transportation systems for refrigeration and freezer performance monitoring, advanced manufacturing for plastics processing and composite cure monitoring as well as assembly line testing with smart packaging.
CPS Offers AlSiC Pin Fin Coolers for Hybrid Electric Vehicle IGBT Applications
CPS Corporation, a company focused on the design and production of metal matrix composites for electronics packaging, offers AlSiC (Aluminum Silicon Carbide), a metal matrix composite, pin fins substrates for liquid cooled high power module systems used in Hybrid Electric Vehicle (HEV) applications.
Liquid cooling is the most effective way to dissipate heat (1 to 2 KW) in HEV power module applications. AlSiC coolers cost effectively offer the pin fin geometries that are required for liquid cooling. In addition, AlSiC coolers provide an isotropic thermal expansion that is compatible with device/electronic substrate to reduce mechanically induced stresses during power thermal cycling for improved electronics and module reliability. The AlSiC device compatible thermal expansion (8 ppm/°C) simplifies IGBT assembly over Cu pin fin coolers, eliminating the need for stress compensation layers that increase thermal resistance and assembly complexity and cost over the higher thermal expansion Cu (17 ppm/°C).
AlSiC is a lightweight material (1/3 of Cu), which makes it an ideal cooler material for the weight-sensitive HEV application. AlSiC also has higher strength and stiffness than Cu, which, combined with its lightweight nature, makes AlSiC coolers more tolerant to shock and vibration.
The CPS AlSiC fabrication process efficiently produces both the composite material and fabricates the product geometry in one process step. CPS can work with customers to provide designs that are fabricated to shape requiring no finished machining for very cost effective cooler production.
DeWAL Industries Introduces Adhesive-Backed, PTFE-Coated Aluminum Tape 
DeWAL Industries, combining PTFE-coated aluminum foil with an adhesive backing, has created a suited tape for heat-sealing and other applications.
Among many applications, the tape, DW 351, is used in high volume heat-sealing equipment and is used as wear strips in light duty sliding applications.
DW 351 combines aluminum foil with PTFE (Teflon) coating, backed with a high temperature pressure-sensitive silicone adhesive.
The result is a high-temperature, abrasion-resistant tape with high tensile strength, along with impact and “cut-through” resistance. The silicone adhesive backing allows it to release cleanly from metal and ceramic surfaces, even rough or inconsistent surfaces.
DW 351 is only available in 0.005 inch (5 mils) thick in 18-yard rolls and can be any width, from 0.5 inch to 12 inches.
eTEC Technology Provides Hot Spot Cooling for ICs
Nextreme has developed an advanced thin film embedded thermoelectric cooler (eTEC) to address thermal management needs of the electronics, photonics, bio-tech and defense/aerospace industries. Functioning as a miniature, solid-state heat pump, the eTEC is ideal for cooling hot spots that result from localized areas of high heat flux on an IC. The nano-structured thermoelectric thin film device is manufactured using semiconductor processing techniques.
“The eTEC pumps heat from one place to another in the same manner that a water pump moves water,” said Dr. Paul A. Magill, Nextreme Thermal Solutions VP of marketing and business development. “By pumping heat from low thermal conductivity materials — the die and thermal interface materials — to a high thermal conductivity material — a heat spreader, the eTEC cools hot spots on ICs. The cooling of hot spots increases product performance, reliability and yield while reducing system costs by simplifying downstream chip cooling requirements.”
The eTEC operates by the Peltier effect, which occurs when an electric current is driven through a circuit containing two dissimilar materials, heat is absorbed at one junction, the cold side, and released at the other junction, the hot side. The eTEC is designed with thin-film compound semiconductor materials that have high electrical conductivity and poor thermal conductivity to maximize current flow and minimize heat flowing back from the hot side to the cold side.
Nextreme’s eTECs are designed utilizing thin films that are small, thin, fast and efficient, which adds 100 microns of height to a heat spreader, enabling unobtrusive integration close to the heat source. The eTEC has an ultra fast, millisecond response time for rapid cooling and heating to maintain a precise temperature depending on the needs of the application. The device pumps a maximum heat flux of 150 W/cm2 with some designs delivering as much as 400 W/cm2 versus less than 10-20 W/cm2 for typical bulk TECs.
Nextreme’s eTECs can operate in a high COP (Coefficient of Performance) regime and still pump a reasonably high heat flux (50 – 100 W/cm2). COP is a measure of efficiency defined as cooling power divided by input power. To cool a 4 W hot spot, an eTEC with a COP of 2.0 would only need 2 W of input power. The input power can be dynamically controlled to provide active cooling. |
Unifrax Completes Acquisition in the Czech Republic
Unifrax I LLC, a manufacturer of ceramic fiber insulation products, recently announced the acquisition of the ceramic fiber business, Keraunion from Union Lesni Brana. Terms of the transaction were not disclosed.
Keraunion is located in Dubi, in the Czech Republic, near Prague and is a supplier of ceramic fiber products in the Czech Republic. The business was acquired by a newly established Unifrax Czech subsidiary, Unifrax s.r.o. and will operate under that name effective immediately.
Unifrax is a global supplier of insulation products that are used in many high-temperature industrial, automotive and fire protection applications.
The company employs approximately 1,300 people worldwide and has 14 manufacturing facilities in the US, Europe, Asia and Latin America.
Petr Skvara, managing director of Keraunion, will stay with the business and serve as a managing director of Unifrax, s.r.o.
New Web Site Makes Specifying Air Filters Easier for Design Engineers
The new Web site for Universal Air Filter, www.uaf.com, is easier to navigate. Seven of the most popular design applications – telecom, power generation, broadband/CATV communications, computer networking, defense electronics, medical equipment and HVAC – are featured on separate landing pages to find specific information faster and more efficiently. Product page banners have been updated to provide clear pictures of various filter frame styles and options.
Design tools such as 3D CAD models, a free prototype service and aftermarket filter information, are now on a series of prominently displayed banners on the UAF home page. |
