Heatpipe and Zipper fin plays an important role in laptop cooling
In the thermal module of laptop, the three key elements are heat pipe, cooing fan and cooling zipper fin. In addition, there are elements used to improve the contact area and heat conduction efficiency between them. The surface of chips such as CPU, GPU, video memory and power supply module are covered with a layer of copper heat sink. As the medium between the chip and the heat pipe, its primary task is to "extract" the heat from the chip quickly, which also increases the contact area and expands the heat dissipation area.
At the same time, there is also a layer of thermal grease as a filler between the chip and the heat sink, and between the heat sink and the heat pipe. For a truly "stress" thermal design, the surface of the heat sink and the heat pipe should also be finely polished - the surface of the copper heat sink and the heat pipe is generally very rough, which will affect its full contact with the thermal conductive silicone grease on the micro level.
The heat pipe is a hollow metal pipe made of pure copper. The part in contact with the CPU / GPU chip is the "evaporation end", and the part in contact with the cooling fin is the "condensation end". The heat pipe is filled with condensate (such as pure water). Its working principle is that the high temperature on the chip surface will convert the liquid at the evaporation end of the heat pipe into steam and move along the tube cavity to the tail of the heat pipe (condensation end). Due to the relatively low temperature in this area, the hot steam will soon be reduced to liquid and flow back to the original position along the inner wall of the heat pipe through capillary action, completing the heat transfer cycle after cycle.
For the design of laptop thermal module , the coarser the diameter and the more the number of heat pipes, the higher the heat conduction efficiency. However, in order to reduce the hot steam in the condensation section of the heat pipe to liquid in the shortest time, higher requirements are also put forward for the cooling fins. Cooling fins are classified as "passive cooling elements" in the field of electronic engineering design. Its material is mainly aluminum and copper. Its working principle is to dissipate the heat transferred from the heat pipe in the form of convection. The heat dissipation efficiency depends on the surface area.
It should be noted that the cooling fins can not exist independently. A group of cooling fins must correspond to a cooling fan and a corresponding cooling outlet. For laptops equipped with 15W or higher TDP processor, the cooling fins can not meet the heat emitted from the chip at all. These heat must be driven away by the fan through the cold air inhaled from the outside!
