How much do you know about finned heat sinks?

The characteristics of finned heat sinks are that the fins break through the original proportional limitations, resulting in good heat dissipation effects, and different materials can be used to make the fins. The drawbacks are also quite obvious, as the heat sink and the base are bonded with thermal paste and solder, which can cause interface resistance issues that affect heat dissipation. To improve these shortcomings, two new technologies have been applied in the field of heat sinks.

　　Fin heat sinkThe feature is that the fins break through the original proportional limitations, providing good heat dissipation. Different materials can be used to make the fins. The drawbacks are also obvious, as the heat sink and base are bonded with thermal paste and solder, which can cause interface resistance issues and affect heat dissipation. To improve these shortcomings, two new technologies have been applied in the field of heat sinks.

The first is the insertion tooth technology, which uses over 60 tons of pressure to bond aluminum plates to the copper base without any medium between the copper. At a microscopic level, atoms are interconnected to a certain extent, completely avoiding the interface thermal resistance disadvantages brought by traditional copper-aluminum bonding, greatly improving the thermal conductivity of the product.

The second is reflow soldering technology. The main issue with traditional bonded heat sinks is interface resistance, and reflow soldering technology is an improvement on this problem. In fact, the reflow soldering process is almost identical to that of traditional bonded heat sinks, except that a special reflow soldering furnace is used to precisely set the welding temperature and time parameters. The solder uses a lead-tin alloy, which can fully contact the welded metal, avoiding missed or weak solder joints, ensuring that the fins are connected to the base as tightly as possible, reducing interface thermal resistance by better controlling the melting time and temperature of each solder joint, ensuring uniformity across all joints.

Compared to aluminum extruded heat sinks, cutting technology solves the limitation of thickness-to-length ratio in fin heat sinks. The cutting process uses special tools to cut the entire material into layers of fins. The fins can be as thin as 0.5mm, and the fins of the fin heat sink and base are integrated, eliminating interface resistance issues. However, due to a large amount of waste during production and low yield rates, this cutting process has relatively high costs, so it mainly favors copper heat sinks.

Fin heat sinks are formed by folding copper or aluminum sheets into integrated fins using a forming machine, then fixing the upper and lower substrates with a punch mold, and finally bonding them with high-frequency metal to form a finished product. This process allows for continuous bonding, making it suitable for producing high aspect ratio fins. Since the fins are integrally formed, it benefits thermal conductivity continuity. The fin thickness is only 0.1mm, which can greatly reduce material requirements while maximizing within allowable weight limits.

Advantages of fin heat sinks:

1. The material is 1050 high thermal conductivity aluminum sheet with a thermal conductivity coefficient as high as 53 (general aluminum extruded thermal conductivity coefficient is 40; die-cast aluminum is only 28).

2. It is stamped type, automatically assembled without welding, has fast production speed, good production process, superior quality, and affordable price.

3. The overall heat dissipation area is large, lightweight, has fast convection, good heat dissipation, and low temperature; it is one of the ideal solutions.

4. The extended cooling fins are vertical to the integrated heat plate, perpendicular to the ground and detached from the heatsink/favorable for forming air convection and beneficial for removing dust and water accumulation.