大功率LED散热用高导热硅脂的研制

以二甲基硅油为基础油,通过添加不同粒径和含量的Al、Cu、Ag、AlN、SiC和石墨,制备了单一填料的单组分以及两种填料大小搭配的二元混合导热硅脂,研究了硬脂酸表面处理、填料种类、大小及比例对导热硅脂热导率的影响,得到了以下结果:硬脂酸处理能提高单组份Al、AlN硅脂的导热性能,但不适用于提高含石墨、SiC、Cu的硅脂的性能;填料填充的最佳比例在0.55~0.60之间;以Ag微粒作为第二填料增强Al和AlN为主填料的硅脂时,对导热率的增强效果高于AlN和Cu、Ag/AlN二元混合硅脂热导率5.5W·m-1·K-1。将制备的导热硅脂用于LED散热,结果表明自制导热硅脂实际散热效果优于市购热界面材料。

Study and Preparation of High Thermal Conductive Grease for High-power LED Heat Dissipation

With dimethyl silicone oil as a base, the single-component thermal grease with one filler material and binary mixture thermal grease with two filler materials have been prepeared by adding Al, Cu, Ag, AlN, SiC, graphite papticles with different contents and different sizes. The influence of stearic acid surface treatment, the material type, size and content of the fillers on the conductivity of the thermal grease have been investigated. It is found that treating Al or AlN by stearic acid can increase the thermal conductivity of the corresponding thermal grease, but can not increase that of graphite, SiC, Cu-containing gease; the optimal ratio of filler should be in the range of 0.55~0.60. When Ag particles is used as a second filler to reinforce the Al and AlN-based grease, the enhancement of thermal conductivity is higher than AlN and Cu, typically, the thermal conductivity of Ag/AlN binary mixtures grease can be up to 5.5W/(m·K). The as-prepared thermal grease has been applied to cool LEDs, it shows that their actual heat dissipation effect is better than the commercially available thermal interface materials.