【作者】 王莉莉；

【导师】 杨德安；

【作者基本信息】 天津大学 ， 材料学， 2010， 硕士

【摘要】 贵金属粉体由于其优良的电学性能和化学稳定性,其作为厚膜浆料的功能相粒子在电子工业领域有着十分广泛的应用。其中金属相粒子的粒径分布及其微观形貌对厚膜金属化膜层的电学、力学性能和焊接性能有很大的影响。本文采用多元醇法和化学还原法制备了形貌均一、粒度分布窄的单独的金、铂及金铂合金粉体,并将其应用到AlN陶瓷厚膜金属化浆料中,研究金属化膜层的可焊性。以HAuCl₄为金源,乙二醇为还原剂,PVP为分散剂单独还原制备了粒径均匀、分散性好的近球形亚微米级Au;采用柠檬酸钠为还原剂,PVP为分散剂分别在60℃和100℃制备了一系列不同粒径分布的且形貌为球形的Au;采用乙二醇为还原剂,PEG400为分散剂分别制备了Au和Pt,单独制备的Pt为纳米级别,形成200nm左右的均匀的团聚体;单独制备的Au的粒径较大约400nm,形状多为不规则球形。利用强还原性的NaBH4,PVP为分散剂同时还原制备了纳米级的Au/Pt合金粉体;采用乙二醇为还原剂,PEG400为分散剂同时还原制备了Pt包裹Au复合粉体,在Au的周围附着上一层Pt纳米颗粒,Au间连接有纳米级的团聚的Pt,将这样结构的Au/Pt复合粉应用到厚膜浆料时可以很好的实现Au/Pt之间的合金化。选用乙二醇制备的Au/Pt复合粉体和NaBH4制备的Au/Pt合金粉体为金属相,CaO-B₂O₃-SiO₂-BaO和CaO-B₂O₃-SiO₂为玻璃结合相,配制组成为70wt%金铂粉体、5wt%玻璃粉和25wt%有机载体的厚膜浆料。经XRD和EDS分析烧结后金/铂得到了很好的合金化,且焊接性能良好。更多还原

【Abstract】 Precious metal powders have a very wide range of applications in electronic industry as a function phase in thick film due to their excellent electrical properties and chemical stability. The properties of particles, such as particle size distribution and morphology, are key to the electrical, mechanical properties and weld ability of thick film. In our experiment, Uniform gold, platinum and their alloy particles with narrow particle size distribution are synthesized by polyol process and chemical reduction ways. The solder ability of metalized film after applying Au/Pt composite in thick film for AlN is also discussed.Au powders with uniform distribution and nearly spherical is synthesized using EG as reducing agent and PVP as dispersant in polyol process; Au having different size distribution and spherical morphology is reduced by sodium citrate using PVP as dispersant in 60℃and 100℃respectively. Au prepared use PEG400 as dispersant in polyol process has larger particle size （400nm） and irregular spherical shape, however, Pt reduced by this method is in nanoscale.Au/Pt alloy powder in nanoscale is co-synthesized by using NaBH4 with strong reducibility and PVP as dispersant; For co-reduction of Pt and Au using PEG400 as dispersant in polyol process, Au is coated by Pt nanoparticles. Au/Pt composite powder with this structure could be be easy to realize Au/Pt alloying when applied to thick film.Use Au/Pt composite powder and the Au/Pt alloy powder as metal phase separately and choose CaO-B₂O₃-SiO₂-BaO and CaO-B₂O₃-SiO₂ as binder respectively to prepare thick film that has 70wt% Au/Pt, 5wt% glass and 25wt% organic vehicle. By XRD and EDS analysis, Au/Pt powder obtain good alloying and has good weld ability.更多还原