5G is fast? Huawei BBU heat dissipation using what advanced materials

Recently, Huawei has been the center of the conversation because of the us government's blockade of Hwei. Huawei's dominance in the global communications industry is due to the core nature of its technology and its recognition by many countries. As early as 2013, Huawei has established communication base stations in more than 80 countries in the world, which accounts for a large share.

Well, let's talk about the heat dissipation design of Huawei BBU (baseband pull-away unit).

So let's see what BBU does. The functions of BBU(Bui lding Base band Unite) indoor baseband processing unit are to complete baseband processing functions of Uu interface (coding, multiplexing, modulation and spread spectrum, etc.), Iub interface functions of RNC, signaling processing, local and remote operation and maintenance functions, and work status monitoring and alarm information reporting functions of NodeB system.

In the front, there are 6 SFP interfaces on the board, and the RRU(radio frequency unit, used to receive mobile phone signals) optical module and optical fiber transmission (above) are hung down.

On the front, you can see that the large fin heat sink covers almost the whole PCB, which can be seen that the heat is so huge when it works, only showing the power part.

After that, as shown in the picture below, the back interface is the socket that connects to the frame and is responsible for communicating with the host.

Looking at the lower surface (below), there is also a large area of heat sink covered, but not a fin heat sink.

Next, what does Huawei BBU look like?

Remove the top of the large heat sink fin, presented in front of the network chip and CPU, and multi-power supply.

Look at the main board. The network chip has a heat-conducting fat on it, and a pile of magnesium-light DDR around it.

This is the CPU BGA package, and the heat transfer grease has not been erased.

Two chips.

Complete heat conduction and grease setting, the surrounding power supply is full of materials.

Metal heat sink, all copper.

Since the application environment of BBU is mostly outdoor, it cannot rely on fans to dissipate heat, because only the thermal design is done on its own basis, and the thermal conductivity of the heat-conducting grease here is estimated to be 5-6w. The heat-conducting grease is characterized by low strength after curing, so it is easy to tear. Unlike heat-conducting silicone grease, it will solidify and seep oil, but there is no heat-conducting gel that can completely solidify. But my feeling is that there should be thermally conductive gel here, so that when you take it apart, you don't have residue everywhere.