Dielectric material helps keep LED packages much cooler

July 02, 2015 // By Paul Buckley
Sheffield-based Litecool has produced LED packages using a dielectric material that has a thermal conductivity of 1000 W/mK which is three times higher than copper and 30 times better than alumina ceramic.

Dielectrics are used within LED packages to isolate electrical tracks but they hinder the thermal path causing the LED to overheat. Mid-lower, low cost LED packages use plastic as the main dielectric material. High-power, high cost LED packages use ceramics such as alumina as the dielectric. This new material, Black X, has a thermal conductivity 30 times higher than alumina.

Litecool has prototyped and tested LED packages using Black X as the dielectric. The LED packages have a thermal resistance of between 0.2⁰C/W and 0.5⁰C/W depending on the construction. This is up to six times lower than the closest competitor which means the LED can be powered with six times more current without overheating.

“It is an incredible material. We have always assumed dielectric materials will hinder the thermal performance of our LED packages but this material actually improves it. The thermal resistances of the LED packages we have made are so low we had trouble measuring it. We had to use nine high power LEDs in one package to give enough power density to record any difference in temperature.” said Robert Corbin, Project Engineer, Litecool

“This is a step change in the performance of an LED package. We will be able to hit new lumen density thresholds without the need for costly heat sinks, heat pipes or fans. We see this material initially being used in spot light applications for pin-point light sources but we also intend to incorporate it into our Lumen Block for the wider LED lighting market.” said James Reeves, CEO, Litecool.

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