Fujitsu uses liquid cooling in its SPARC servers, and is preparing a similar system for mobile devices. Liquid Loop Cooling is a closed system using pumps to move coolant around a motherboard, although pumps would not be viable in the smaller form factors of smartphones, tablets and laptops. Instead, Fujitsu has developed a loop heat pipe that is less than 1mm thick.
According to the company, ‘A loop heat pipe is a heat-transfer device that consists of an evaporator that absorbs heat from the heat source and a condenser that dissipates that heat away, with the two components connected by pipes into a loop. A working fluid is encapsulated inside this closed loop as a coolant. The heat from the heat source evaporates the coolant, and the energy that goes into evaporating the coolant is taken away from the heat source, lowering its temperature. It is based off of the same principle used when sprinkling water on pavement to reduce heat’.
Patterning in the system is performed by etching metal sheets – so the pipe layout and heat transferred can be customised on a per-device basis. Fujitsu aims to have a working system with manufacturers in 2017.
