Heat pipes are closed evaporator-condenser heat transfer systems. A heat pipe’s wick structure and embedded liquid enables it to produce a very high heat flux transport capability, which can be 10-20 times higher than the equivalent diameter solid copper pipe. The application of heat pipes in the thermal management of electronics has increased considerably in recent years because of PCB space constraints and increasing component and power density.

 

 

They are used to transfer heat with minimal temperature difference from the heat source (evaporator) to the heat sink (condenser) as well as to spread the heat across a surface. Many factors have to be considered in choosing a heat pipe for a specific application. The effective length (Leff) is a useful indicator of the length of a heat pipe as employed in a specific application (accounting for evaporation and condensation lengths). Heat pipes come in round or flat shapes. Flat heat pipes are easier to attach to heat dissipating components while the round heat pipes offer advantages for certain fin configurations at the condenser end.