Monday, September 21, 2009

"MATERIALS: Phase-changing thermal management to prolong LED lifespan"

Heat often causes undesirable changes in phase, such as melting insulators, but what if engineers instead harnesses phase changes for good? Honeywell has done just that with a new family of phase changing thermal management materials which change from a hard plastic into a soft polymer in response to heat, in the process increasing their thermal conductivity and thus cooling off the device. Look for Honeywell phase-changing materials to supplant silicone-based paste over the next few years. R.C.J.

Honeywell engineer stencil prints its thermal management material on the base of an aluminum heat sink similar to those used to cool light-emitting diodes for a flat-panel display backlight.

A new family of phase-changing thermal management material from Honeywell is claimed to improve the lifespan of light-emitting diode (LED) arrays used for display backlights and solid-state lighting, by changing phase during use to more efficienty transfer heat away from devices. Called Honeywell LTM6300-SP, the phase-changing material replaces traditional silicone-based pastes which pump out and degrade at high temperatures, with a polymer matrix embedded with thermally conductive metals. The new material is the first in a family of phase change materials being developed by HEM the growing LED lighting applications, including street lamps, automotive lighting, flat panel TV displays and computer monitors.