Who would have guessed that a Japanese company called Fujikura is actually responsible for the R600 cooler. The GPU is covered by a vapor chamber and the liquid inside evaporates and goes via heat pipes to copper fins where it's cooled.
The cooler is officially known as Fujikura Advanced Vapour Chamber. Vapour chamber is a two phase water working fluid device and fortunately it is totally sealed. It is a passive part and it doesn’t have any moving parts.
We are talking about the reference design cooler and we even have some schematics for you. Who would have though that this is actually a water / liquid cooler after all.