Along with thermal impedance, knowing a materials thermal conductivity is very important. Thermal conductivity describes a material’s ability to conduct heat and is independent of material size, shape, and orientation. Using Fourier’s Law, the designer can better understand how to find thermal conductivity of a homogeneous material. Fourier’s Law states the rate at which heat is conducted through a material is proportional to the area normal to the heat flow and to the temperature gradient along the heat flow path. Using this, a material’s thermal conductivity (k) can be determined. In this image, the grey rectangle represents the thermal material where its thermal conductivity can be measured by knowing all inputs including the power, cross sectional area of the thermal interface material (TIM), the temperature difference, and the distance heat is transmitted. Keep in mind that many of Chomerics’ thermal materials are non-homogeneous as some include liners such as fiberglass, mesh or polymer film reinforcements. For these materials, the term “relative thermal conductivity” is appropriate because the thermal conductivity of these materials depends on the relative thickness of the layers and their orientation with respect to heat flow.