Why didn't graphene, liquid metal and silica gel shake the position of silicone grease on radiators?

2023-01-25

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It will get warmer soon. In order to make the computer safe for the summer, players will disassemble the computer and laptop to perform a series of operations to improve heat dissipation. Among them is the coating of the processor with silicone grease. indispensable. When it comes to applying silicone grease, some players may have some doubts: after so many years of operating the machine, the space between the processor and the heatsink is almost filled with silicone grease, and there are so many thermal conductive materials, why? can they be replaced by other materials? Today we will discuss this topic.

Why didn't graphene, liquid metal and silica gel shake the position of silicone grease on radiators?
Why do we use silicone grease?

The workflow of a conventional air-cooled heatsink is that the heat generated by the CPU is first transferred to the base of the heatsink, then transferred to the fins at the end with a heat pipe, and then the fan is cooled. The closer the heatsink base and the CPU are, the better the cooling effect will be. But, on the one hand, with the current processing technology, it is impossible to guarantee that the surface of the processor and the cooling base will be absolutely smooth and flat, when they are in close contact, tiny gaps will inevitably remain. On the other hand, in the heatsink installation process, the user does not operate in a standardized manner, and the buckle is not installed properly, which will also lead to a large gap between the CPU surface and the cooling base.

Why didn't graphene, liquid metal and silica gel shake the position of silicone grease on radiators?

After installing the heatsink, air will enter these gaps. We know that the thermal conductivity of air is only 0.024, which is much lower than 377 for copper and 230 for aluminum, which will reduce the thermal conductivity of the heatsink, which in turn will affect the heat dissipation of the processor. . To eliminate these gaps, it is necessary to add a filler between them, which is a thermal paste.

Why didn't graphene, liquid metal and silica gel shake the position of silicone grease on radiators?

Furthermore, many players may think that the more heat dissipating silicone grease is applied, the better the thermal conductivity will be. In fact, the heat dissipating silicone grease only plays the role of filling the gap, and its thermal conductivity is about 8, which is completely incomparable with metal, if applied too much, it will affect the heat dissipation.

Can other fillers replace silicone grease

In IT products, silicone grease is not the only material used to dissipate heat. Common materials are graphene, liquid metal, silica gel, etc. These materials are easy to obtain and the price can be affordable for players. replace silicone grease? When used as fillers for heatsinks and processors, the materials listed above have their drawbacks, and they really aren't as good as silicone grease.

First of all, let's talk about graphene. Typically, graphene is used for heat dissipation and is used to make paints. After applied to the equipment, a film will form on the surface, which looks smooth, but actually has a wavy inner surface, the function of which is to improve the heat transfer effect by increasing the heat dissipation area. It’s just that such paint cannot be sprayed onto the base, and of course it will not replace silicone grease. On the other hand, although graphene paint can be used on heat dissipation fins to improve heat dissipation performance, the operation is more difficult and only suitable for enthusiasts with strong practical skills.

The second one is liquid metal. The liquid metal we're talking about is not the magical, self-healing sci-fi material from Terminator 2, but low-temperature gold with a very low melting point, which can even become liquid at 25°C. This material can replace silicone grease as a filler, and its thermal conductivity of more than 128 is also a great advantage. But why is liquid metal little used? Personally, I find installation and use more troublesome. Because the main chassis have vertically mounted heatsinks, liquid metal can drip onto the motherboard and graphics card, causing a short circuit. When installing liquid metal, silicone grease should be circled around the circle, so its use is more troublesome. At the same time, liquid metal also has the disadvantages of aluminum base corrosion and hardening in winter, which is not intended for use by ordinary players.

Why didn't graphene, liquid metal and silica gel shake the position of silicone grease on radiators?

The last one is silicone, which can often be seen under the motherboard, the heatsink of the video card power module. Don't look at the difference between its name and silicone grease, but the difference between the two is huge. The silicone is directly converted into a patch, and there is no need to apply it evenly like silicone grease. So why not use it on a CPU cooler? The main reason is that the silica gel is too thick and its thermal conductivity is actually very average, and if used on a heatsink, it will reduce the heat dissipation performance. Therefore, this material is commonly used in places with relatively low heat dissipation requirements, such as power modules and video memory.

Since there are obvious issues with materials such as graphene, liquid metal, and silicone, silicone grease is still the best choice as a filler between the CPU and heatsink.