超细银粉及导体浆料的制备及导电性能

Preparation and Conductivity of Ultrafine Silver Conductive Paste

为了制备高性能银导体浆料,由直流电弧等离子体蒸发法制备超细银粉。采用自制银粉、有机载体和玻璃粉成功制备了厚膜导体浆料,并系统研究了烧结工艺对银浆导电性能的影响。结合X射线衍射、X射线荧光分析、透射电镜、扫描电镜、共聚焦激光扫描显微镜、热分析等分析手段,研究了银粉的形貌、纯度及浆料导带的形貌和热性能。结果表明：球形超细银粉的纯度高达99.92%（质量比）,一次颗粒平均粒径为120 nm,粒径分布在40~250 nm之间。推荐最佳的浆料制备工艺为：银浆的组成选取为85%银粉、2%玻璃粉以及13%的有机载体,在800℃的峰值温度下保温10 min,该浆料的方阻为2 mΩ/□。

The ultra-fine silver powder,fabricated by DC arc plasma evaporation,was mixed with organic vehicle and commercial glass frit powders to prepare a novel type of silver conductive paste. The influence of the sintering conditions,including the contents of major ingredients,sintering temperature and time,and Ag-grain size,on the electrical conductivity of the sintered coatings of Ag paste was investigated. The microstructures,electrical and thermal properties of Ag powder and the sintered Ag coatings were characterized with X-ray diffraction,X-ray fluorescence spectroscopy,scanning electron microscopy,transmission electron microscopy,confocal scanning laser microscopy,and differential scanning calorimetry / thermogravimetry. The spherical Ag grains contain 99. 92%（ wt） Ag with a size distribution range of 40 ~ 250 nm,and an average diameter of 120 nm. The results show that the sintering conditions strongly affect the sheet resistance of the Ag paste coatings. Sintered at 800℃ for 10 min.,the sheet resistance of the coating,with 85% Ag particle,2% glass frit powders,and 13% organic vehicle,was found to be 2 mΩ / □.