Aluminum Thermal Straps
Solderless Flexible Thermal Links
TAI no longer offers aluminum foil thermal straps, due to low customer demand and high manufacturing costs when compared with copper straps. While aluminum thermal straps/aluminum thermal links (AlTS) may be beneficial in some very limited applications, it is important to understand that AlTS are really only one type of thermal strap that should be considered for a unique combination of performance parameters. For example, AlTS can sometimes have a slight advantage over copper thermal straps (CuTS®) and graphite thermal straps (GFTS®) under a very narrow set of parameters that include trade offs between thermal conductance, mass, volume, and stiffness.
Because 1100 Al has roughly one third the density of copper and half the thermal conductivity, intrinsically there is a mass benefit of up to one third less for aluminum compared to copper straps. However, there are a number of other factors to consider including:
1) Aluminum straps will occupy twice the volume of copper straps for the same thermal conductance.
2) Aluminum straps are limited to stacked-foil configurations that do not provide good flexibility on each axes. This means that curvature must be included in the thermal strap design to permit directional flexibility between the strap ends. When this is done, more mass and volume are added to the strap in order to maintain a specified thermal conductance, thereby reducing any benefit over copper braided thermal straps.
3) Aluminum readily forms an oxide that can greatly degrade thermal performance at interface locations without proper surface passivation measures.
4) Aluminum foil straps are far more expensive than TAI's CuTS®, and competing AlTS are the same price as TAI's GFTS® products.
5) Aluminum straps have more handling and integration constraints than copper rope straps.
Comparison of Thermal Conductivity