Fabrication and characterization of freestanding β-SiC/SiO_xC_y/C_(free) heat dissipation ceramic films by precursor method

Freestandingβ-SiC/SiOxCy/Cfreenanocomposite films were synthesized by melt spinning the polycarbosilane(PCS)precursor.Their microstructure were characterized by Fourier transform infrared(FT-IR),Xray diffraction(XRD)and Raman spectroscopy,morphology analysis was investigated by scanning electron microscope(SEM).Resistivity and thermal conductivity of the films were measured at room temperature.Effect of pyrolysis temperatures on the heat dissipation properties of nanocomposite films were investigated.The results show that thermal conductivity increases as the resistivity of theβ-SiC/SiOxCy/Cfreefilms decreases by increasing pyrolysis temperatures.The sample sintered at 1 200 ℃ with good insulation(2.1×108Ω·m)and high heat transfer capability(46.8 W/(m·K))can be silk-screened and used as heat dissipation substrate for high-power LED devices.The obtained results are expected to have important applications in high-temperature electronic and advanced optoelectronic devices.