Ah, I think we could be stuck in the symantics. I had understood your use of the term "solder" to mean the solder used for mounting electrical components, like CPUs, resistors, capacitors, etc. Both the metal and the material: typical melting point 180-250°c. Whereas, the IHS thermal attachment method we see on CPUs or other components with IHS, can be using one of two methods: 1./ Adhesive TIM, similar to those heatsinks you see on PCBs that are not attached via clips but "glued" to the chip. The adhesive can soften or indeed melt at higher temperatures. 2./ Indium foil. It is a thin sheet of metal (foil) that is inserted between the die and the IHS and is a low-temperature, controlled thickness material, used for thermal attachment. However, the point still stands, that if the CPU is so hot as to melt the thermal attachement materials, the temperature is probably high enough to damage the CPU (first) rather than just melting the TAM, reducing the cooling ability, so that overclocks are lower. I span the google machine and found this: http://www.indium.com/blogs/TIM-Blog/Indium-Foil-a-Thermal-Interface-Material/20081003,27,2938/ . Lots of interesting reads on the site.