Enhanced Heat Dissipation of High-Power Light-Emitting Diodes by Cu Nanoparticle Paste

Abstract

Light-emitting diodes (LEDs) are considered as a next-generation lighting due to their high luminous efficiency, low power consumption, and long lifetime. However, the low heat dissipation of LEDs is an inevitable roadblock. Here, a high heat-conducting Cu nanoparticle (NP) paste was prepared and demonstrated for high-power LEDs. The effects of sintering temperature on the electrical and thermal properties of the Cu NP paste were investigated. The junction temperature change and thermal resistance of LEDs were measured and compared with the traditional die-attach materials. Consequently, the Cu NP paste sintered at 250 °C possesses low electrical resistivity of $5.1~{ \mu \Omega \cdot }$ cm and high thermal conductivity of 142.37 W/(m.K). The packaged LEDs display the low thermal resistance of 6.58 K/W and the low junction temperature change of 3.22 °C, which are significantly lower than those of LEDs packaged by the traditional die-attach materials. These results demonstrate that the promising Cu NP paste provides a feasible and effective strategy for enhancing the heat dissipation of high-power LEDs.