Diamond-Added-Copper Heat Spreader for UV LED Applications

Abstract

In this study, composite electroplating technique is used to fabricate the diamond-added copper (DAC) heat spreader for UV LED applications. Thermal dissipation characteristic and optical performance are improved as the composite DAC heat spreader adoption. The low thermal resistance of 18.4 K/W with UV LED using DAC heat spreader was measured. Surface temperature of UV LED using the DAC heat spreader is 45.32◦C (at 350 mA injecting current), which is lower than those of LEDs using pure copper heat spreader (50.11oC) and only sapphire substrate (62.49◦C). The thermal diffusivity of the DAC is 0.7179 cm2/s measurement by laser flash method. Output power and power efficiency of UV LEDs are also enhanced to 71.81 mW and 4.32%, respectively, at 350 mA injection current. The optimal structure design and materials fabrication will be discussed

Suppression of phonon heat conduction in cross-section-modulated nanowires

“…Heat transfer processes at nanoscale continue to attract significant attention. [1][2][3][4][5][6][7] Nanostructured materials with the high lattice thermal conductivity can be used as heat spreaders and interconnects [7][8][9][10] for enhanced heat removal from the nanoscale circuits. Materials with the low lattice thermal conductivity and high electrical conductivity are promising for thermoelectric applications since the measure of the efficiency of the thermoelectric energy conversion-figure of merit ZT -contains the electrical conductivity in the numerator and the lattice thermal conductivity in the denominator: ZT = S 2 σ T /(κ ph + κ el ), where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ ph and κ el are the phonon, i.e., lattice and electron thermal conductivities, respectively.…”

Phonons and Thermal Transport in Si/SiO2 Multishell Nanotubes: Atomistic Study

“…Phonon engineering, i.e., targeted modification of phonon modes in nanostructures to enhance their thermal [5,9,10], electrical [9] and optical properties [11,12], manifests itself as a powerful tool for the optimization of nanoscale thermal transport [5,9,10]. Nanomaterials with high thermal conductivity (TC), such as graphene, are promising candidates as heat spreaders and interconnectors [13][14][15][16], while nanomaterials with low thermal conductivity and high electrical conductivity can be used for thermoelectric applications. The efficiency of the thermoelectric energy conversion, figure of merit ZT, is directly proportional to the electrical conductivity and inversely proportional to the total thermal conductivity: ZT = S 2 σT/ κ ph + κ el , where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ ph and κ el are the phonon and electron thermal conductivities, respectively.…”