以金刚石粉、环氧树脂E-20、甲醚化氨基树脂、助剂制备成导热绝缘胶粘剂,在130℃保温30 min,210℃保温10 min固化.胶粘剂固化后导热系数随金刚石粉体积含量增加先增大后减少,存在一个极大值.相同金刚石粉体积含量下,较大粒径的金刚石粉之间能形成更好的物理接触,有利于导热性能的提高.用常用经验导热模型拟合胶粘剂固化后的导热系数结果表明:在金刚石粉体积分数小于16.6%时,Maxwell方程能较好拟合胶粘剂的导热系数;体积分数为16.6%~44.7%时,Bruggeman和Agari模型能较好地描述胶粘剂的导热系数.
A thermal conductivity and insulating adhesive was prepared by diamond particle,epoxy resin(E-20),methanol etherified amino resin and additives.The adhesive was cured by drying at 130℃ for 30minutes and then at 210℃ for 10minutes.The thermal conductivity coefficient when the cured adhesive shows a transition from increasing to decreasing with the increasing of the diamond particle volume content in the adhesive.Diamond particles with large size can enlarge physical contact area between diamond particles,which improve the thermal conductivity of the cured adhesive.The thermal conductivity of the cured adhesive was simulated by the commonly used empirical models.The simulation results indicated that the Maxwell equation was in accordance with the thermal conductivity coefficient when the cured adhesive with the volume ratio of the diamond particle was less than 16.6%,while Bruggeman model and Agari model were in agreement with the experimental data when the cured adhesive with the volume ratio of the diamond particle was from 16.6% to 44.7%.