The heat pipe is a known device for cooling a heat generating component, such as a CPU (Central Processing Unit) or the like, mounted in an electronic apparatus. The heat pipe is a device that transfers heat by utilizing a phase change of a working fluid.
A loop heat pipe is an example of the heat pipe, and includes an evaporator that vaporizes the working fluid, and a condenser that liquefies the vaporized working fluid. The evaporator and the condenser are connected via a liquid pipe and a vapor pipe that form a loop-shaped passage (or channel). In the loop heat pipe, the working fluid flows through the loop-shaped passage in one direction. The evaporator and the condenser of the loop heat pipe are formed on the same plane, as described in International Publication No. WO2015/087451A1, for example.
However, in an actual product, a heat generating part and a heat sink part do not necessary exist on the same substrate (that is, on the same plane). When providing the loop heat pipe in the product in which the heat generating part and the heat sink do not exist on the same substrate, the vapor pipe and the liquid pipe need to be bent in order to mount the evaporator on the heat generating part and to mount the heat sink part on the condenser. However, when the hollow pipe is bent, an inner side of the pipe shrinks, while an outer side of the pipe stretches. For this reason, an inside of the bent part of the pipe becomes constricted and prevents a smooth flow of the working fluid, to make it difficult to transfer the heat from the heat generating part to the heat sink part.