Evaluation of Aging Performance of Thermal Gel Subjected to Laser Flash Tests

As an important class of thermal management material, thermal gel is widely used to fille the gaps between heat generating devices and the heat sink. The performance of thermal gel varies when withstanding high environment temperature. Real-time monitoring the intrinsic thermal conductivity
${(k)}$
of thermal gels, and the variation of interfacial thermal resistance
${(R}_{i})$
at the thermal gel/substrate interface during the aging process is urgently-needed for exploring the anti-aging mechanism and further improve the overall transfer performance. In this study, laser flash method was applied as to characterize the thermal performance. We experimentally demonstrate that there exists strong dependence of
$\boldsymbol{k}$
-thickness in single-layered test and thus introducing great data error. Double-layered test could largely weaken the
$\boldsymbol{k}$
-thickness dependence of thin thermal gel layer and provide the detailed
$\boldsymbol{R}$
i
value for conference simultaneously. The results illustrate that the double layers-based laser flash method could be a crucial tool to real-time characterize
$\boldsymbol{k}$
and
$\boldsymbol{R}$
i of thermal gel-metal system during the aging process.