高分散微米银粉的宏量制备及其烧结性能研究

Large-scale preparation and sintering performance study of highly dispersed micron-sized silver powder

熔融烧结过程中形成稳定可靠的连续导电通路是电子系统互联封装用导电银浆电性能提升的关键,其核心影响因素是银颗粒尺寸、形状、复配体系。采用绿色温和的液相还原方法实现了粒径、形貌可控的微米级银粉的宏量制备。研究了制备工艺参数对微米银粉粒径分布、表面形貌的影响规律。将制得的均匀粒径微米银粉(质量分数70%)与商用纳米银粉(质量分数5%)复配作为共导电填料制备了导电银浆。结果表明,微、纳米银粉复配制备的导电银浆在烧结过程中更有利于导电网络的形成。其中,当复配银粉质量分数为75%时,烧结银浆电阻率可低至1.8×10^(-8)Ω·m。

During the process of the melt sintering,the formation of a stable and reliable continuous conductive path is the key to improve the electrical performance of the conductive silver paste for the electronic system interconnect packaging.The core influencing factors are the size,shape,and compounding system of the silver particles.A green and mild liquid-phase reduction method was used to achieve the large scale preparation of the controllable micro-sized silver powders in terms of particle size and morphology.The impact of the process parameters on the particle size distribution and surface morphology of micrometer-sized silver powders was studied.The prepared uniform micro-sized silver powder(70%mass fraction)was compounded with nano-sized silver powder(5%mass fraction)as a co-conductive filler to prepare the conductive silver paste.The results show that the preparation of the conductive silver paste through the complexing of micro and nano silver powders is more conducive due to the formation of the conductive networks during the sintering.When the mass fraction of the co-conductive filler is 75%,the resistivity is 1.8×10^(-8)Ω·m.