分散剂对磨制片状银粉性能的影响?

Influence of dispersants on the properties of flake silver powders by milling

以热分解碳酸银得到的类球形银粉作为前驱体,使用硬脂酸、油酸、蓖麻油酸及正辛酸作为分散剂,采用机械球磨法制备片状银粉。通过扫描电镜(scanning electron microscope,SEM)、粒度分布统计(particle size distribution,PSD)、松装密度仪、振实密度仪、四探针仪等手段测试了片状银粉的显微形貌、粒度分布、松装密度、振实密度及导电性。结果表明,分散剂分子中碳链的长度影响片状银粉物理性能,使用油酸作为分散剂可以得到粒径分布窄、松装密度为1.0 g·cm^(-3)、振实密度为1.7 g·cm^(-3)的片状银粉,调制含质量分数50%Ag的低温固化银浆,其方阻小于10 mΩ·□^(-1)。

Spherical silver powders prepared by the thermal decomposition of silver carbonate were used as the precursors to produce the flake silver powders by mechanical ball milling, adding stearic acid, oleic acid, ricinoleic acid, and caprylic acid as the dispersants. Scanning electron microscope(SEM), particle size distribution(PSD) statistics, apparent density tester, tap density tester,and four point probe instrument were used to study the microstructures, particle size distribution, apparent density, tap density, and conductivity of the flake silver powders. The results show that, the length of carbon chain in dispersant molecules affects the properties of flake silver powders. The flake silver powders in narrower particle size distribution with the apparent density of 1.0 g·cm-3 and the tap density of 1.7 g·cm-3 can be obtained by using oleic acid as the dispersant, and the sheet resistance of silver paste by low temperature curing in the Ag mass fraction of 50% can be below 10 mΩ·□-1.