银粉对导电银浆表面微结构及导电性能的影响

选用4种不同形貌和堆积密度的银粉制备导电银浆,比较其性能差异,优选一种银粉,在此基础上添加不同比例的纳米银粉,对烧结后的银浆样品进行表面形貌分析和方阻测试。研究不同形貌银粉及搭配对导电银浆性能及膜层结构的影响,结果表明,堆积密度大的球形银粉膜层致密,孔洞较少,方阻为3.2 mΩ/□;在此球形银粉中添加纳米银粉,提高了填充烧结性能,有助于减少烧结后膜层的孔洞,增加了银粉之间的导电通路,从而大大减小膜层的方阻,提高银浆综合性能;球形银粉中加入6%的纳米银粉时,方阻最小,达到2.1 mΩ/□,膜层结构最致密。

Effect of Silver Powder on Surface Microstructure and Properties of Conductive Silver Paste

Silver paste was prepared from four kinds of silver powders with different morphology and tap density.A kind of silver powder is preferred by comparing their properties.We also studied effect of the content of silver nano powders on the silver film surface morphology and sheet resistance after sintering.The testing results showed that the film with spherical silver powders of highly tap density is less holes,the sheet resistance is 3.2 mΩ/□.Adding nano silver powder in the spherical silver powder enhances the sintering performance,helps to reduce the holes in the sintered film,and improves conductive connection between the silver powder,so as to the sheet resistance of the silver film is greatly reduced and the overall performance of the silver paste is improved.When 6%of the silver nano powder is added to the spherical silver powders,the sheet resistance is 2.1 mΩ/□,the silver film is densest.