Thermal conductivity is expressed in watts per meter and kelvin (`W/(mK)`) and has values between 0.025 `W/(mK)` for air, 220 `W/(mK)` for aluminum and 370 `W/(mK)` for copper. In addition, there are thermal conductive foils with a thermal conductivity of up to 1,950 `W/(mK)`. This is five times the thermal conductivity of copper. The thermal conductivity corresponds to the reciprocal of the thermal resistance. The higher the thermal conductivity, the more heat is dissipated.