Ultra-Thin Ceramic Substrates for Improved Heat Sinking for MicroLEDs

Micro light emitting diodes (MicroLEDs) provide unrivaled luminance and operating lifetime, which has led to significant activity using devices for display and non-display applications. The small size and high power density of microLEDs, however, causes increased adverse heating effects that can limit performance. A new generation of electrically insulating high thermal conductivity materials, such as alumina, is proposed to mitigate these thermal effects when used as a substrate as an alternative to glass. This strategy can then be used as a method of passive heat sinking to improve the overall performance of the microLED. In this work, a newly available material, an 80 micron thick alumina ceramic substrate, is shown to yield a 30 % improvement on average in the maximum current drive over a glass substrate. The small size of current microLEDs creates intensely localized heating during operation that can cause the microLED to degrade rapidly. While several active heat sinking options is used, passive heat sinking by engineering the substrate can provide superior heat sinking without any power draw. Ultrathin ceramic substrates, like those available from Corning, are an ideal candidate for such a solution.image