Better mechanical, thermal properties and longer lifetimes are needed for the die attach layer in high-power electronic packaging. As traditional Sn–Ag–Cu (SAC) solders have many limitations, the sintered nanosilver materials are becoming one of the substitutes for high-power electronic packaging. However, the high performance of sintered nanosilver materials is only achieved when its fine sintering densification is formed. This article investigates the sintering densification process of nanosilver particles based on the design of orthogonal experiments and sintering kinetics modeling in which both the macroproperties and micromorphology are linked and analyzed. The results lead to several conclusions, such as: 1) the orthogonal experiments consider the effects of sintering temperature, dwell time, and sample preparation pressure on the sintering relative shrinkage and relative density—the results show that the most critical impact factor on sintering densification is the sintering temperature. (2) In the sintering kinetic experiments, the sintering densification rates obtained by fitting the relative density versus dwell time curves during 175 °C–250 °C follow the Arrhenius model, and the apparent activation energy of sintering kinetics is calculated to be 36 kJ/mol, while it is calculated from the particle size is 38.1 kJ/mol. 3) Through modeling the relationship between particle size, line shrinkage, and porosity, the line shrinkage and porosity first increase at the initial stage, while the particle size increases, and the macroscopic volume decreases at the end of sintering, the porosity decreases.

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大功率电子包装用纳米银颗粒烧结动力学的实验研究

大功率电子封装中的芯片连接层需要更好的机械，热性能和更长的使用寿命。由于传统的Sn-Ag-Cu（SAC）焊料具有许多局限性，因此，烧结的纳米银材料正成为大功率电子封装的替代品之一。然而，仅当形成其精细的烧结致密化时，才能实现纳米银烧结材料的高性能。本文在正交实验设计和烧结动力学模型的基础上，研究了纳米银颗粒的烧结致密化过程，并结合了宏观性能和微观形貌。结果得出以下结论，例如：1）正交实验考虑了烧结温度，停留时间的影响，以及样品制备压力对烧结的相对收缩率和相对密度的影响—结果表明，对烧结致密化最关键的影响因素是烧结温度。（2）在烧结动力学实验中，通过拟合175°C–250°C期间的相对密度与停留时间曲线获得的烧结致密化速率遵循Arrhenius模型，计算得出的烧结动力学的表观活化能为36 kJ / mol，而根据粒径计算为38.1kJ / mol。3）通过对粒度，线收缩率和孔隙率之间的关系进行建模，线收缩率和孔隙率在初始阶段首先增加，而粒度增加，并且在烧结结束时宏观体积减小，则孔隙率降低。