News - MH&W Thermal Products

Heat Management for LED Modules

Kerafol has authored a new guide for managing thermal issues when designing driver electronics for LED applications.

LEDs are being used in more and more ways. Due to their brightness, high efficiency and long life expectancy, they continue to conquer domains that only recently were reserved for traditional light sources. This means that driver electronics must be adapted to an ever-increasing number of applications.

When designing LED driver electronics, several points must be considered. One important point is the active components’ power loss. The semiconductors’ TJ should stay far below the maximum value shown on the datasheet. The life of semiconductors is mainly influenced by the height of the developing temperature. This means that a heat analysis is absolutely necessary.

Download the Whitepaper: Heat Managment for LED Modules.pdf

Thermal Gap Fillers Combine High Performance and Low Pricing

New TP-S30 thermal interface pads from MH&W International provide 3.0 W/mK of thermal conductivity between hot components and heat sinks at lower costs than competing gap filler materials. Pads of TP-S30 thermal gap fillers are soft and compliant for easy compression and filling of air gaps between mounting surfaces to optimize heat transfer. Applications for these gap fillers include alternative energy, consumer electronics, telecommunications, power supplies, flat panel displays, and portable electronics.

Pricing for standard TP- S30 gap filler material starts at $0.07 (0.5 mm thick) per square inch. Lower pricing is available for TP-S materials with lower thermal conductivities, i.e. 2.0 and 1.0 W/mK (TP-S20 and TP-S10). A low silicone content version, TP-S30LS, has less than 50 parts per million silicone content for applications where silicone-based outgassing can lead to contamination problems or oily silicone residues can hamper assembly.

All TP-S series gap fillers are provided in 210 x 297 mm (8.3 x 11.7 inch) sheets or in standard die cut shapes. Custom shapes are available. Standard materials have a Shore 00 hardness of 45. Standard thicknesses range from 0.5 to 5.0 mm. All materials are UL94 V0 rated and have a use temperature range of -60° to +200° C.

For more information on TP-S thermal gap filler materials, visit http://www.mhw-thermal.com/products/csc_tps.htm, or call 201-891-8800

Introducing Keratherm KL 90 and KL 91

Mounting Tape Provides up to Three Times the Thermal Conductivity of Competing Tapes

MH&W International has introduced Keratherm® KL 90 highly thermally conductive, double-sided adhesive tape which provides 1.4 W/mK of thermal conductivity – nearly three times higher than other thermal tapes – for more effective heat transfer from hot components to heat sinks. The new tape’s thermal impedance is just 208°C-mm2/W (0.32°K-in2/W).

Keratherm KL 90 tape consists of a ceramic-filled acrylic adhesive film that provides exceptional bonding properties, and replaces the use of mechanical fasteners, reducing costs and assembly time. A fiberglass-reinforced version, KL 91, is available for applications requiring higher levels of ruggedness, peel strength, and conformability to irregular surfaces. Both Keratherm KL 90 and KL 91 mounting tapes are silicone-free, eliminating any contamination concerns. If necessary, the tapes can be cleanly removed using a thin-edge blade.

Keratherm KL 90 double-sided adhesive tape is supplied on 400 mm (15.75 in) wide rolls, and is also available in custom die-cut shapes. Its standard material thickness is 0.300 mm, (0.012 in). KL 90 tape pricing starts at $0.22 per square inch in high volume orders. Developed and manufactured by Kerafol, a world leader in thermal interface material innovation, complete information on Keratherm KL 90 thermal adhesive tape can be found at www.mhw-thermal.com.

Silicone-Free Interface Material Provides High Thermal Conductivity

MH&W International has introduced Keratherm U 90 thermal interface material, manufactured by Kerafol, for use where contamination concerns prohibit the use of silicone-based thermal pads, but where high levels of thermal conductivity are needed for sufficient thermal transfer in hot electronic devices.

U 90 material consists of a ceramic-filled polyurethane film with thermal conductivity of 6.0 W/mK and thermal impedance of just 0.05 Kin2/W. The material has a high voltage breakdown property of 4.0 kV. It provides strong perforation protection with a tensile strength of 2.5 N/mm2 and a Shore A hardness of 70.

Typical applications for silicone-free U 90 thermal interface pads include medical devices, laser equipment, lighting systems, solar energy, disk drives and aerospace electronics.

MH&W’s Keratherm U 90 interface material is available in 0.100 and 0.200 mm thicknesses (3.9 and 7.8 mil). Standard and custom shapes are available in continuous rolls for automated or manual application. Pricing for U 90 thermal interface pads starts at $0.15 for 1 inch square, 0.200 mm thick pads in high volume quantities.

U 90 silicone-free thermal interface materials are part of Kerafol’s Keratherm line of thermally conductive interface materials. More information on U 90 pads can be found at www.mhw-thermal.com or by calling 1-201-891-8800 for samples and quotes.

Choosing Thermal Interface Materials

Knowing Your Application Needs is Key to Picking the Best TIM

As component powers continue to grow, so do their cooling requirements. One rule of thumb says that for every 10°C rise of the junction temperature the failure rate doubles. Thus, there is an urgent need to remove heat from hot chips to the surrounding air stream. Demand has led to a variety of new thermal management systems. But nearly all of these continue to use thermal interface materials, or TIMS, to effectively provide heat flow across the mating interfaces of cooling systems.

The essential purpose of TIMs is to maintain effective transfer of heat from hot chips to dissipating devices such as heat sinks or spreaders. As heat flows, it encounters thermal resistances that impede overall heat transfer. TIMs reduce the most problematic of these, the contact resistance between the mating parts (heat source – heat sink). Air gaps significantly limit heat flow from the hot component into the sink or spreader. An effective TIM replaces the gaps created by the non-smooth mating surfaces with a material whose thermal conductivity is much greater than that of air. Basically, it replaces poor conduction from point contacts and air to enhanced conduction through solids.
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