于烧结后的性能表征与烧结工艺的优化，而在烧结过程中的银纳米颗粒在微观尺度下的演变规律、有机分散剂的分解机制等问题仍缺乏系统性的研究。本研究基于一款国产喷墨打印电路板设备的研发项目背景，对银纳米颗粒墨水的烧结机制展开探索，并对其烧结工艺进行优化研究。 首先，本研究对银纳米颗粒墨水进行热分析，发现气氛会对墨水的热处理过程产生影响，氧气的存在有助于墨水中有机物的氧化分解。红外光谱的测定显示含氧气氛烧结的薄膜中有机残留显著降低。通过管式炉烧结实验，发现在150-350℃的温度范围内，烧结温度的提高能促进银纳米颗粒的融合，最优性能样品为在350℃的纯氧中烧结30 min的薄膜，其电阻率降至2.5 μΩ·cm，是块状银电阻率的1.52倍。通过扫描电镜观测薄膜微观形貌发现，氧气能促进银纳米颗粒的烧结过程。根据对烧结过程的机理分析，高含氧量能有效提升银原子的表面扩散能力，促进银纳米颗粒间的聚结与融合，增大银颗粒平均尺寸，有效减少界面电阻，从而提高了样品导电率。 基于烧结机制的研究，接下来本研究针对柔性基材不耐高温的特点设计了近红外烧结系统，并对烧结的关键参数展开探究，分析了近红外烧结的薄膜样品电阻率受烧结时间、功率密度的影响，发现较大的辐射功率密度能加速烧结，但是功率的进一步提高会导致烧结薄膜表面出现裂纹。与该设备之前的热处理方法相比，本研究中使用的红外烧结工艺把烧结时间从一小时降至数秒。最优性能样品为在功率密度为10 W/cm2下处理8 s的电阻率降至2.59 μΩ·cm的导电薄膜，仅为块体银的1.57倍，这一样品性能满足了项目研发的指标要求。 本研究的学术价值与工程意义主要体现在：（1）从提升银原子扩散能力和促进有机物分解两方面探究并验证了氧气对于银纳米颗粒烧结过程的促进效果；（2）从微观形貌的演化层面，总结了银纳米颗粒烧结过程中烧结机制；（3）设计并优化了近红外烧结系统，实现了银纳米颗粒的高效快速烧结。

Inkjet printing technology has received extensive attention in the field of advanced manufacturing due to its advantages such as high efficiency, environmental protection, and flexibility. The sintering process is a key step to obtain stable morphology and good conductive function of inkjet printing conductive inks. Most of the existing research focuses on the performance characterization after sintering and the optimization of the sintering process. There is still a lack of systematic research on the evolution law of organic dispersants and the decomposition mechanism of organic dispersants. Based on the background of a research and development project of a domestic inkjet printing circuit board equipment, this research explored the sintering mechanism of silver nanoparticle ink, and conducted an optimization study on its sintering process.First, the thermal analysis of the silver nanoparticle ink was carried out, and it was found that the atmosphere would affect the heat treatment process of the ink, and the presence of oxygen would contribute to the oxidative decomposition of the organic matter in the ink. Infrared spectroscopy measurements showed that the organic residues in the films sintered in an oxygen-containing atmosphere were significantly reduced. Through the tube furnace sintering experiment, it was found that in the temperature range of 150-350℃, the increase of the sintering temperature could promote the coalescence of silver nanoparticles. The best performance sample was the film sintered in oxygen at 350℃ for 30 min. The resistivity was only 2.5 μΩ·cm, which is 1.52 times the resistivity of bulk silver. The microscopic morphology of the film was observed by scanning electron microscopy, and it was found that oxygen could promote the sintering process of silver nanoparticles. According to the mechanism analysis of the sintering process, high oxygen content could effectively improve the surface diffusion ability of silver atoms, promote the coalescence and fusion between silver nanoparticles, increase the average size of silver particles, effectively reduce the interface resistance, and thus improve the conductivity of the sample.Based on the research on the sintering mechanism, this research designed a near-infrared sintering system for the characteristics of flexible substrates that are not resistant to high temperature, and explored the key parameters of sintering. It was found that a larger radiation power density could accelerate the sintering, but further increase of the power would cause cracks on the surface of the sintered film. The near-infrared sintering process used in this study reduced the sintering time from one hour to several seconds compared to the previous heat treatment method for this device. The sample with the best performance was the conductive film whose resistivity was only 2.59 μΩ·cm after sintered with the power density of 10 W/cm2 for 8 s, which was only 1.57 times that of bulk silver. The performance of this sample meets the requirements of the project research and development.The academic value and engineering significance of this study are mainly reflected in: (1) The promotion effect of oxygen on the sintering process of silver nanoparticles was explored and verified from the two aspects of improving the diffusion ability of silver atoms and promoting the decomposition of organics; (2) From the perspective of microscopic morphology, the sintering mechanism of silver nanoparticles during heat treatment was summarized; (3) A near-infrared sintering system was designed and optimized to achieve efficient and rapid sintering of silver nanoparticles.