Thermal Diffusivity Distribution Measurements of a High-Thermal-Conductive Heat Dissipating Sheet

High-thermal-conductive heat dissipating sheet is an important material for promoting heat release. In this study, the correlation between the distribution of local thermal diffusivity and volume fraction was discussed. The local thermal diffusivity of the high-thermal-conductive heat dissipating sheet was measured using the laser flash method and the spot periodic heating and infrared radiation thermometer method. The volume fraction of the high-thermal-conductive heat dissipating sheet was evaluated through microscopic observation. It was observed that the local thermal diffusivity of the approximately 0.5 mm-thick high-thermal-conductive heat dissipating sheet measured using the spot periodic heating and infrared radiation thermometer method was close to that measured using the laser flash method. The correlation between the distribution of the local thermal diffusivity and volume fraction was evident.