HEAT DISSIPATION OF AAU IN 5G BASE STATION

With the introduction of large-scale antenna technology to 5G base station, the volume, weight and heat dissipation of AAU are challenged. How to find a balance point among the three and do well in AAU design requires the use of a variety of new technologies, new processes and new materials.

AAU traditional heat dissipation scheme:

1. To reduce the temperature difference between the chip and the shell, high heat conduction interface material and heat bridge heat conduction block or heat pipe are used;

2. Reduce the surface temperature of the shell, increase the shell volume and surface area of the equipment;

3. Improve the temperature uniformity of the shell, use cast aluminum to thicken the shell.

New cooling scheme of AAU base station:

The heat generated by the internal heating module of the base station will increase the temperature in the sealed chamber. When the temperature is the same, it will be transmitted to the shell for heat convection through air. AAU heat dissipation can start with new materials, new structure design and new heat dissipation scheme.

(1) New cooling scheme, liquid cooling.

Liquid cooling and heat dissipation module: there is special heat dissipation liquid under the heat conduction pipe connected with the heat sink. Its boiling point is relatively low. After the heat is absorbed, it will evaporate to the top. After the heat is dissipated, it will liquefy again and return to the original place, so as to improve the heat dissipation efficiency.

                                                                                 Picture: liquid cooling module with auxiliary board

However, due to the interface thermal resistance between the rigid material and the heat sink, Tim material must be used inside. Such as heat conducting gel, thermal conductive silicone grease, thermal conductive gasket, etc.

2) New materials: In addition to Tim, heat dissipation materials and solutions used in AAU, semi-solid die casting has the advantages of light weight and good heat dissipation performance. Roll bond plate has the advantages of high heat transfer efficiency and fast cooling speed. Combining the heat dissipation devices of semi-solid die casting and roll bond plate, it is expected to significantly improve the heat dissipation value of 5G base station.

                                                                                                           Picture: Roll bond plate

Failure to do AAU heat dissipation will cause equipment power consumption to rise, which is a serious challenge for operators and an important obstacle for us to promote 5G construction. If the heat dissipation problem cannot be effectively solved, the implementation and long-term development of 5G will be affected.