Industry dynamic

Is the thermal pad thicker or thinner?


Thermally conductive silicone gasket is a kind of thermally conductive interface material. Its main function is to fill the gap between the heat sink and the heat sink, or to reduce the contact thermal resistance between the two. According to Fourier's thermal conduction theory, the thermal resistance is inversely proportional to the thickness of the material, the thicker the material, the higher the thermal resistance value, so when choosing to use it, the thinner the better.


However, the actual assembly conditions need to be considered: for example, the minimum gap between the radiator and the heat source (after pressurization), if it is 1.0mm, then you can choose a 1.2mm thermal pad, so that the thermal pad can be fully assembled after assembly. Fill the gap between the two. If you choose a thermal pad of 1.0mm or less, there will still be a gap after assembly, forming a large amount of thermal resistance. It doesn't make much sense to use thermal pads.


In addition, there are other things to consider:

(1)The thermal conductivity of the thermal pad itself, the same thickness, the higher the thermal conductivity, the lower the thermal resistance, and the better the thermal conductivity.


(2)The surface hardness of the thermal pad, the smaller the hardness, the softer the product, the better the compliance to the radiator and heat source, the higher the wetting performance, the smaller the contact thermal resistance, and the better the thermal conductivity.


(3)The rebound performance of the thermal pad, or the compression deformation of the thermal pad. The better the resilience, the lower the amount of compression set, and the better the material's ability to keep gaps filled. The better the heat conduction effect is.


Of course, there are other factors, such as the tear strength of the surface, to ensure that the material will not be damaged during the assembly process, resulting in breakage or gaps, which is also easy to form a large thermal resistance. In conclusion, the sole purpose of using a thermal pad is to reduce the thermal contact resistance between the heat sink and the heat source. When selecting, refer not only to the various parameters of the thermal pad, but also to the actual assembly process parameters.