含有热界面材料的界面热阻模型

An Interface Resistance Model of Thermal Interstitial Materials

界面材料不完全填充固体界面间隙时,界面热阻R_j由两部分组成:界面材料和固体接触处的接触热阻Rc及间隙内的气体热阻Rg。界面热阻R_j难以测量,建立有效模型准确地预测界面热阻十分重要。基于界面化学模型,建立了一个针对填充具有流体性质的界面材料的界面热阻模型。比较发现界面热阻模型的预测值比界面化学模型的预测值与实验值更加吻合。分析表明:残留在间隙内的气体热阻Rg在界面材料导热系数k_(TIM)较大时不能忽略;界面热阻Rj随固体界面粗糙度σ的增大而增大,随界面材料导热系数kTIM的减小而增大。

When thermal interface materials can＇t fill crevices of two contact surfaces completely, thermal interface resistance consists of two parts： the contact resistance between the thermal interface material and solid, and the gap resistance of the gas left in the surfaces crevices. Thermal interface resistance is hard to be measured, so it is important to build an effective model to predict it. Based on the surface chemistry model, thermal interface resistance model of fluidic interstitial materials is built. The comparisons between experimental and modelling results indicate the thermal interface resistance model matches the experimental results better than the surface chemistry model. The comparisons also show that the gap resistance cannot be neglect when the thermal conductivity of the thermal interface material is relatively high. And the thermal interface resistance will increase with substrate roughness increasing, and thermal conductivity decreasing of the thermal interface material.