Fabrication of Ag-MWNT nanocomposite paste for high-power LED package

• The Ag-MWNT nanocomposite paste was utilized as TIM for a high-power LED package.
• The highest thermal conductivity of the Ag-MWNT nanocomposite was 21.1 W/mK.
• Ag decorated MWNTs improved the thermal conductivity of the nanocomposite paste.
• The Ag-MWNT nanocomposite enhanced heat dissipation and luminous efficiency.

A silver-multi-walled carbon nanotube (Ag-MWNT) nanocomposite was utilized as a thermal interface material for a high-power light-emitting diode (LED) package. The nanocomposite was fabricated by screen printing and sintering of a nanocomposite paste comprising Ag-decorated MWNTs mixed with Ag nanoparticles dispersed in an organic solvent. The Ag-MWNT nanocomposite sintered at 300 °C for 30 min with 3 wt.% MWNT exhibited the highest thermal conductivity of 21.1 W/mK at room temperature and the lowest thermal resistance of ∼6.6 K/W. Percolation networks of Ag-decorated MWNTs between Ag nanoparticles led to improved thermal conduction, resulting in excellent heat dissipation and luminous efficiency of the high-power LED package. The LED package fabricated with an Ag nanocomposite paste containing 3 wt.% MWNT exhibited a 7% decrease in operating temperature of LED chips compared with that of the basic structure of a metal printed circuit board.