固化工艺对树脂基导电胶电性能的影响

Influence of Curing Procedures on the Electrical Properties of Epoxy-Based Isotropic Conductive Adhesives

摘要:

本文以微米银片为导电填料制备了环氧树脂基各向异性导电胶，研究了固化工艺对导电胶电性能的影响。研究结果表明，固化工艺对银粉填量为55 wt％的导电胶影响较大。当固化温度是180 0C时，体积电阻率是5.2×10-2 Ω.cm，当固化温度是250 0C时，体积电阻率下降到4.5×10-3 Ω.cm. 然而，固化温度对高银粉填量的导电胶的影响较小。原位监测65 wt％的各向异性导电胶的固化过程中的电性能，发现固化27 分钟后体系温度是180 0C， 此时的电阻是1.99×106 Ω，40 分钟后的电阻是1.39 ×103 Ω，60 分钟后的电阻是18.8 Ω.冷却时，导电胶的电阻几乎不变化。采用扫描电阻显微镜分析了银粉在树脂基体中的分布，进而讨论了固化温度对体积电阻率的影响机制。

Abstract:

In this paper, a typical isotropic conductive adhesives (ICAs) composed of an epoxy-based binder containing micro-sized silver flakes was prepared and the effects of the different curing procedures on the electrical properties of the ICAs were investigated. The results showed that there is greater influence of the curing temperature on 55 wt % silver loading, the volume resistivity of ICAs decreased to 4.5 ×10-3 from 5.2×10-2 cured at 250 0C and 180 0C, respectively. However, there is almost no effect on the high silver loading. The in situ monitoring the variations in electrical resistance of the ICAs with 65 wt % silver loading was studied during the curing process, and it was found that the resistance reached to 1.99 ×106 Ω at 180 0C after cured for 27 min, and reached to 1.39 ×10-3 Ω for 40 min, and 18.8 Ω for 60 min and the cooling process has almost no effect on the electrical resistance of the ICAs. The reasons for the dependence of the bulk resistivity on temperatures were also discussed in terms of the dispersing of the silver flakes in ICAs by SEM.