Enhanced Heat Dissipation of WLEDs Packaged Using 3D Substrate With Geopolymer/BN Paste

In this letter, a three-dimensional dam was fabricated by direct ink printing of geopolymer/hexagonal boron nitride paste on a direct plated copper substrate to package high-power white light-emitting diodes (WLEDs). Compared to traditional dam fabricated and glued on substrate by organic material, the geopolymer-based dam with higher thermal conductivity enhanced heat dissipation. At temperature of 300(degrees)C, the solidified geopolymer-based dam demonstrated excellent thermal reliability. The phosphor weight in silicone was optimized to tune WLED optical performance. At 9 wt%, the resulting WLED demonstrated natural white light luminous efficiency equal to 142.26 lm/W, a correlated color temperature equal to 4304 K, and color rendering index equal to 59 under the 350 mA driving current. These results show that this novel packaged design provides a reliable and effective strategy for enhancing heat dissipation of high-power WLEDs.