Thermal characterization of polycrystalline diamond using infrared thermal imaging measurement*

Thermal characterization of polycrystalline diamond based on an infrared thermal imaging technique is proposed. The temperature mapping of polycrystalline diamond under a metal wire heating are recorded using a $15~\mu \text{m}$-resolution infrared thermal imaging system. The thermal conductivity of the polycrystalline diamond is derived from the temperature profile using numerical fitting with a 3D heat diffusion model. The thermal conductivity of the polycrystalline diamond is also determined using a $3\omega$ technique. The agreement between the thermal conductivities measured using these two techniques is within 15%.