Is thermal conductivity alone enough to justify the use of a metal thermal interface?
Absolutely not! If it were, everyone would have already moved on to implementing diamond or carbon nanotubes as their interfaces. When I measure the performance of thermal interface materials, I characterize them based on their thermal resistance. This value is typically more valuable than bulk thermal conductivity. For a compressible TIM, the thermal resistance assumes the actual contact which will be made between the interface material and it’s mating surfaces. This provides a measurement of thermal performance which is as close to real-world per Watt or per cm2 as I can provide without being application-specific. The thermal resistance value is incredibly valuable, but even that is not the deciding factor for whether to implement a specific thermal interface material. In addition to an application’s unique requirements, there are other material properties which are commonly investigated to justify the selection of a thermal interface material. For instance, there is the compatibilit
