Laser-Sintered Silver Nanoparticles as a Die Adhesive Layer for High-Power Light-Emitting Diodes

A laser-sintered die adhesive based on silver nanoparticles (AgNPs) is used to fabricate high-power light-emitting diodes (LEDs). Following the optimization of the laser power and the irradiation time, the laser sintering of AgNPs without any organic binder shows the comparable adhesion property to that of conventional LED chip bonding layer with silicone and silver-loaded epoxy adhesives. Among tested LEDs, devices using the laser-sintered AgNP adhesive exhibit the best performance in both light-emitting efficiency and reliability, which are governed by the thermal conducting property of chip bonder. Morphological analyses indicate that the elongated microstructure of AgNP-adhesive layer by laser-sintering process contributes to the performance enhancement of LEDs.