固化过程及银粉形貌对导电胶电阻率的影响.pdf

第 14 卷第 6 期 粉末冶金材料科学与工程 2009 年 12 月 Vol.14 No.6 Materials Science and Engineering of Powder Metallurgy Dec. 2009 固化过程及银粉形貌对导电胶电阻率的影响 孙 健 1,2 ，李芝华 1,2 (1. 中南大学 材料科学与工程学院，长沙 410083 ； 2. 中南大学 有色金属材料科学与工程教育部重点实验室，长沙 410083) 摘 要：采用 2 种不同形貌的银粉、3 种不同固化收缩率的导电胶基体配制 6 种导电胶，研究等温固化过程中导 电胶基体的固化收缩率以及银粉形貌对导电胶电阻率的影响，探讨导电胶的导电机理。结果表明，银粉形貌对导 电胶的电阻率影响较小；基体固化收缩率越大，使得银粉颗粒之间的接触面积增大，发生隧道效应的几率也增大， 所以导电胶的电阻率越小，基体的固化收缩对导电胶导电性能的形成贡献较大，在导电胶由不导电到导电的转变 过程中起着决定性的作用。导电胶未固化前是不导电的，导电性的建立发生在导电胶基体的凝胶化阶段，且在这 一阶段中导电胶的电阻率随时间延长急剧下降，之后趋于稳定。 关键词：导电胶；固化收缩；导电机理；体积电阻率 中图分类号：TQ 324.8 文献标识码：A 文章编号：1673-0224(2009)6-427-05 Effect of curing process and morphology of silver powder on resistivity of ECA SUN Jian1,2, LI Zhi-hua1,2 (1. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 2. Key Laboratory of Nonferrous Metal Materials Science and Engineering of Ministry of Education, Central South University, Changsha 410083, China) Abstract: Based on two kinds of silver powder with different morphology and three matrixes with different curing shrinkage, six electrical conductive adhesives (ECA) were prepared. The effects of the curing shrinkage of matrix and the morphology of silver powder on the resistivity of the ECA were studied. The conductive mechanism of ECA has also been explored. The results show that the morphology of silver powder has less influence on the resistivity, while the curing s