What is a insert fin heat sink

The chip heat sink, also known as the insert fin heat sink, is a different molding method compared with the extrusion radiator, stamping FIN fin welding radiator and other radiator molding processes. As the name suggests, the literal interpretation is to insert the cooling fins into the substrate one piece at a time, thereby conducting the heat from the substrate to the cooling fins. This is a completely different radiator manufacturing process from profiles, die casting, CNC, etc.

1.What are the types of insert fin heat sink? What are the advantages and disadvantages of each?

According to the connection between the heat fin and the substrate, it can be divided into the following types:\

(1) Welding type: the fin and the substrate are connected together by solder welding, with high temperature brazing and low temperature solder paste welding;

Welding heat transfer performance is good, but solder paste welding Al substrate and heat sink, need to be nickel plating, high cost, not suitable for large size radiator, and brazing although no nickel plating is required, but the welding cost is still very high.

(2) Riveted type: After the fin is inserted into the groove of the substrate, the groove is squeezed to the center through the mold, so as to tightly hold the cooling fin to achieve a tight and firm combination;

The advantage of the riveted type is good heat transfer performance, but the riveted product has the risk of gap and loosening after repeated use, although the reliability can be improved by improving the riveting process, but the cost will also increase accordingly. Therefore, the riveted blade radiator is often used in occasions where the reliability requirement is not high.

(3) Adhesive type: Generally the use of thermal epoxy resin, the heat fin and the substrate tightly bonded to achieve heat conduction.

The adhesive adopts thermal conductive epoxy resin, whose thermal conductivity is much lower than that of welding, but it is suitable for heat sinks with high FIN, high multiple ratio and small spacing, and can be used in scenarios with low heat dissipation performance requirements.

2. The manufacturing process of the insert fin heat sink

Step1: Make the cooling aluminum/copper substrate and heat sink according to the design, and slot the substrate. Different connection methods, slot shape and fit tolerance will also be different;

Step2: Install the FIN. Insert the fin piece by piece into the slot made in step 1;

Step3: The heat fin and the bottom plate are joined together (welding or bonding can be used according to the design requirements);

Step4: After the base plate and the heat sink are fixed, the subsequent drilling, tapping, and milling on the fins and the base plate can be carried out, and the corresponding surface treatment is finally done, that is, the finished product of the insert radiator.

3.Application status of insert fin heat sink

In general, the initial appearance of the insert fin heat sink is to solve the problem that the heat fin and the substrate material are different, and the high, dense, and thin heat fin are difficult to form by other means. However, with the development of technology, many chip radiators have been replaced by the shovel tooth process. Compared with the two, whether it is the early grooving processing or riveting or welding, the process of the insert radiator is more complicated and the cost is high. The blade teeth can be thinner, higher and smaller spacing than the insert, and the fin and the substrate are a whole, with excellent heat transfer performance and simple processing technology. It can also solve the problem of different materials (such as copper and aluminum composite sheets).

Of course, as a kind of heat sink molding process, in some scenes or some special circumstances of the design, it still has irreplaceable advantages. For example, we need to insert the blown plate group into the water cooled substrate, or the ultra-thin temperature equalizing plate group into the water cooled substrate or the heat envelope tube into the copper substrate, we are actually using the insert molding process.

The process itself has no advantages and disadvantages, and the most suitable for the product and the most cost-effective is a good process.