Thermal boundary resistance of mechanical contacts between solids at sub-ambient temperatures

The experimental values of the thermal boundary resistance occurring at interfaces between two solids at sub-ambient temperatures are reviewed. New data are presented in the temperature range from 4 K to 300 K for the thermal resistance between different metals (Cu, stainless steel), interlayered by various cryogenic bonding agents (Apiezon-N, Cryocon grease, In and InGa), or mechanically connected (dry) contacts. Depending on the contact materials, the thermal conductance varies between 10(2) W m(-2) K-1 and 5 x 10(4) W m(-2) K-1 at room temperature, and decreases approximately linearly by one order of magnitude between 200 K and 20 K. Our experimental data agree well with the data reported in the literature for the temperature range below 4 K and measurements near room temperature.