Indium Blog

How the Performance of Compressible Thermal Interface Materials Changes With Pressure

One of the really good things about using thermal grease in a compression thermal interface is that pressure does not have too much of an effect on it; the thermal resistance stays relatively consistent at various standard assembly pressures - when the grease remains in situ.

(Typically 0.10 to 0.14 cm2*°C/W) Metal thermal interface materials (mTIMs)s are effected by pressure, but we have found a way to optimize mTIM performance using lower pressure.

The curves on the graph represent thermal resistance as a function of pressure for five different thermal interface materials (TIMs). Less resistance = higher thermal transfer = a better thermal material. Basically, this translates to more rapid cooling for the electronic device.

At most clamping pressures, nothing can beat the performance of a pure indium HeatSpring®. A very close second performing material is the 1E HeatSpring® – which trades in a bit of the alloy’s indium content for tin. To be exact, Indalloy® #1E is 52% indium and 48% tin, and boasts an impressive thermal resistance of only 0.0390 cm2*°C/W at 100psi and 0.004” bond-line thickness! The concept of the HeatSpring® was developed by a group of engineers at the Indium Corporation to improve upon the traditional flat indium mTIM (which is shown as the green curve in the graph). As you will notice, even the flat material performs quite well compared to other typical TIMs.

If you need a high-performance thermal interface material, let our engineers find the perfect solution for your application.


Authored by previous Indium Application Manager Jim Hisert