纳米银线对导电胶电阻率影响研究

Effect of silver nanowires on the resistivity of electronically conductive adhesives

摘要:

本文采用溶剂热法成功合成30-90 μm 的纳米银线。以自制的纳米银线和商用微米银片为导电填料制备了环氧树脂基导电胶，研究了纳米银含量和固化温度对导电胶电阻率的影响。研究结果表明，当固化温度为180 0C时，随着纳米银含量的增加，体积电阻率先下降而后又增加；随着固化温度的增加，体积电阻率下降。当银粉总填量为65 wt％ （ 微米银片和纳米银线的含量比：55：10）时，导电胶在180 0C和300固化的体积电阻率分别为6.5?0-4 Ω?cm 和1.3?0-4 Ω?cm。分析认为电阻率的下降与纳米银线在300 0C出现烧结行为有关。根据纳米银线在树脂基体中的分布、烧结行和纳米银线与微米银片间的相互作用关系等讨论了纳米银线对导电胶电阻率的影响机制。

Abstract:

In this paper, large-scale silver nanowires with a lenghth of 30-90 μm were successfully synthesized by a polyol process. Electronically conductive adhesives (ECAs) were made by adding micro-sized silver flakes and silver nanowires to the polymer composites consisted mainly of epoxy resin, cure agent and catalyst. The volume resistivity of the ECAs was researched as a function of silver filling loading and sintering temperature. The results indicated that the volume resistivity of ECAs first decreased and then increased with the increase of fractions of silver nanowires when curing temperature at 180 0C. With the increase of curing temperature, the volume resistivity of ECAs increased. In the condition of the ECAs filled 65% silver fillers (the ratio of silver micro-sized silver flakes and silver nanowires is 55:10), the volume resistivity of ECAs reached 6.5?0-4 Ω?cm and 1.3?0-4 Ω?cm cured at 180 0C and 300 0C, respectively. The dramatic improvement in the conductivity of the ECAs is due to the low-temperature sintering of the silver nanowires at 300 0C. Effect of silver nanowires on the resistivity of ECAs was discussed in terms of the distribution and sintering behavior of silver nanowires and interaction relationship between silver nanowires and micro-sized silver flakes.