Metal thermal pad 's typical structure of the combination onto the fan is that a number of sheet heat conducting fins are engaged in a certain process on the heat-absorbing bottom with a certain thickness.
Disadvantages: the airflow needs to change the direction in the thermal plate, which is easy to form a "no wind zone". Moreover, the overhead type of the traditional axial flow fan is easy to form a dead Angle -- "wind blind zone" -- in the part of the inter-bearing, but the thermal plate is in the center of the contact is the heating equipment (CPU core, etc.).
A typical metal thermal pad design, with a solid copper column as the main shaft, radiates the thermal fin outward from the inside, and inversely bends the fin towards the fan to increase contact with the airflow. With this kind of design, the blind area of the axial flow fan just corresponds to the copper core of the thermal conductor, and the copper core itself has a small exposed surface area, which is difficult to improve the thermal conductivity with the aid of airflow.
Meantime, some of the outer fins are just under the fan's strong wind, the thermal effect of nature excellent. Its design can be said to be an "evasive" approach: the wind blind area is avoided by clever design, minimizing the negative impact brought by it; And compared to the "conventional turbo" fan mentioned later, the copper core has a larger contact area with the thermal fins, which can better transfer heat to all parts of the fins.