Why does the CPU need thermal pad? How to choose thermal pad?
Both thermal silicone sheets and thermal grease are used to assist CPU heat dissipation, so as to maximize the heat dissipation capacity of the CPU fan. So what is the difference between the two? Which one is better to use?
Thermal conductive silicone sheets/Thermal pad are generally used in places where it is inconvenient to apply thermal conductive silicone grease, such as the power supply part of the motherboard. The power supply part of the current motherboard generates a lot of heat, but the MOS tube part is not flat, so it is not convenient to apply thermal conductive silicone grease, so you can stick silicone paper on it. In addition, under the heat sink of the graphics card, multiple parts need to contact different parts on the graphics card, and thermal conductive silicone grease is also inconvenient to use, so you can replace it with thermal conductive silicone sheets. It is recommended to use thermal conductive silicone grease on the CPU of a general desktop computer, because for such parts, we disassemble and assemble them more frequently than hardware. Applying thermal conductive silicone grease is more convenient for other operations in the future. Thermal conductive silicone grease Thermal conductive silicone sheet In addition to the above reasons, the following is the difference between CPU thermal conductive silicone grease and thermal conductive silicone sheet:
2.Thermal conductivity
Thermally conductive silicone sheet: Although thermally conductive silicone sheet has high thermal conductivity, its thermal conductivity is usually slightly lower than that of thermal grease. This is mainly because the thermal resistance of silicone sheet is relatively large, but it performs well in filling gaps and maintaining long-term stability.
Thermally conductive silicone grease: Thermally conductive silicone grease has good fluidity and can better fill the tiny gaps between the CPU and the radiator, thereby improving the efficiency of heat conduction. Its thermal conductivity is usually high and is suitable for scenarios that require efficient heat dissipation.
3.Electrical insulation
Thermally conductive silicone sheet: Thermally conductive silicone sheet usually has good electrical insulation, and its electrical insulation index can reach more than 4000 volts at a thickness of 1mm, which can effectively prevent short circuit risks.
Thermally conductive silicone grease: Although most thermally conductive silicone greases are also electrically insulating, their insulation properties may vary depending on factors such as brand and formula. When choosing, pay special attention to whether its electrical insulation meets the requirements.
4.Physical form
CPU thermal conductive silicone sheet/thermal pad: solid material, made of a mixture of silicone rubber and thermally conductive fillers (such as metal oxides or carbon-based materials). Its form is usually in the form of sheets, with thickness ranging from 0.3mm to 10mm, and can be cut into different shapes and sizes as needed.
CPU thermal grease: a paste-like liquid or semi-solid material, mainly composed of fillers such as silicone oil and metal oxides. It is soft and has a certain fluidity.
5.Thickness
As a thermal conductive material for filling gaps, thermal grease is limited. The thickness of thermal conductive silicone sheets ranges from 0.25-4mm, and the application range is wide.
6.Application method
CPU thermal conductive silicone sheet: The installation is relatively simple. Just tear off the dust-proof protective film and paste it between the CPU and the radiator according to the pre-cut size. Because it has a certain softness and elasticity, it can fill small gaps well and increase the contact area.
CPU thermal grease: It is more complicated to use. You need to clean the surface of the CPU and the radiator first, then apply an appropriate amount of grease on the contact area, and apply it evenly with your fingers or tools to ensure that there is no omission and excessive thickness. Its construction accuracy requirements are high to ensure the efficiency of heat conduction.
7.Price
Thermal grease is widely used and has a low price. Thermal silicone sheets are mostly used in thin, small and precise electronic products such as laptops and lighting, and the price is slightly higher.
8.Service life
Thermal silicone sheets/pad: Due to its solid-state properties and good aging resistance, the service life of thermal silicone sheets is relatively long. Under normal use conditions, its thermal conductivity can remain stable for a long time.
Thermal silicone grease: Although thermal silicone grease has excellent thermal conductivity in the early stage, it may reduce its thermal conductivity due to aging, drying or contamination over time. Therefore, it needs to be checked and replaced regularly to ensure the heat dissipation effect.
9.Convenience of disassembly and assembly
Thermal silicone sheets: Easy to disassemble and assemble, just gently peel off and re-paste a new silicone sheet without re-applying. This is especially applicable in situations where the CPU radiator needs to be frequently disassembled and assembled.
Thermal silicone grease: After disassembly and assembly, the silicone grease needs to be re-applied, and the application process is relatively complicated, and uniformity and thickness need to be ensured. This increases the difficulty and cost of disassembly and assembly to a certain extent.
10.Application scenarios
Thermal conductive silicone sheet/thermal pad: Suitable for occasions that need to fill large gaps, maintain long-term stability or require frequent disassembly and assembly. Such as widely used in CPU cooling systems of notebook computers, servers and other equipment.
Thermal conductive silicone grease: More suitable for occasions with extremely high requirements for thermal conductivity and low frequency of disassembly and assembly. Such as the cooling system of high-performance desktop CPU.
In summary, CPU thermal conductive silicone sheet and CPU thermal conductive silicone grease are different in physical form, application method, thermal conductivity, service life, insulation, disassembly and assembly convenience, and usage scenarios. When choosing, you need to consider comprehensively according to specific needs and scenarios.
With the continuous advancement of science and technology, the manufacturing technology of thermal conductive silicone and silicone rubber is also constantly innovating. In the future, Changmai thermal conductive silicone grease and thermal conductive insulation sheet are expected to have greater breakthroughs in the thermal conductivity, temperature resistance range and mechanical strength of these two materials. Please feel free to contact Changmai at any time, we will be happy to help you. Let us work together to make thermal conductive silicone sheets play a greater role in various fields and contribute to social development and technological progress.
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