Phase change materials as a viable thermal interface material for high-power electronic applications

Phase change materials (PCMs) are an attractive alternative to thermal greases/pads. While their thermal conductivity is not as good as greases, they are more manufacturable. This paper reports on evaluation of PCMs for high power electronic applications. Conductivity measurements were carried out for several OEM PCMs. In addition experiments were carried out to determine process parameters (to attain target thermal impedance). A few candidates were then evaluated in a single chip module, under different environmental stresses and the results are presented here. The design concept was then extended to an MCM test vehicle and two candidate PCMs were evaluated. Differences in the reliability performance between SCM and MCM form factor are explained.