Thermal barriers used in developing thermal management solutions don’t get the same mention in engineering conversations as say heat sinks, thermal resistance, fans or even thermal epoxy! You generally don’t want to put anything up as a potential “barrier” to any air movement, since that would defeat the purpose of your thermal management in the first place. But what is a thermal barrier and why would you use it?
A thermal barrier is a a material used to reduce the movement of heat. In this way, it can be used to shield some components from others that are very high heat. This causes the heat from a source to become spread out, and you shield the components on the other side. For example, a mobile phone might use several pieces of flexible graphite to create a thermal barrier shielding some components from the high heat of others. A netbook or tablet could conceivably employ thermal barriers as well, so that the heat from the CPU doesn’t negatively impact the other components being shielded.
Thermal barriers may also be used when the heat transfer from the higher heat device might cause another device to be thermally out of specification, resulting in the chips thermal circuit to trip, shutting down the device or reducing it’s performance potential.