无压低温烧结多尺度银-镍界面互连封装SiC器件的研究

面向SiC耐高温封装互连材料和技术的高强度、长寿命需求，本项目以分子动力学模拟和原位实验观测相结合，拟解决：.（1）澄清纳米-亚微米-微米多尺度银焊膏的低温致密烧结和还原性有机体系-镍氧化抑制的动力学和热力学机制，提高颗粒堆积密度和固相含量，以化学驱动力替代机械驱动力，实现无压低温致密烧结多尺度银焊膏材料；.（2）揭示工艺方法-宏观性能-微观特征的关联机制，实现低温致密烧结银-镍界面的无氧化、高强度互连工艺方法；.（3）澄清烧结银-镍界面互连的宏观性能和微观特征在温度冲击、功率循环和湿热老化过程中的退化演变规律，基于Weibull数据统计和Coffin-Manson模型建立失效判据，指导优化长寿命可靠性设计等关键难点问题。.这对于实现以镍代替金或银等贵金属镀层，简化工艺降低成本，推动拓展烧结银互连材料和技术应用范围，实现SiC高温封装材料与技术突破，具有非常重要的科学理论和工程应用价值。

This proposal is aimed at developing a pressureless sintered multiscale-silver die attachment on nickel metallization technology for packaging SiC power devices that can function reliably at high-temperature over 200°C. To achieve the goal, we will focus our efforts to achieve the following objectives: .(1) understand the kinetics and thermodynamic mechanisms of pressureless low-temperature densification sintering of multiscale, i.e. nano-submicron-micron silver particles, and effects of reductive organic systems on Ni oxidation suppression, and realize pressureless low-temperature sintered silver densification bondline by increasing chemical driving force, packing density and solid loading of the multiscale silver paste material;.(2) clarify the correlation mechanism between nickel oxidation inhibition and oxygen-deficient bonding by densification sealing and organics reduction during sintering, establish processing-microstructures-properties relationships, and achieve the technology of strong and oxidation-free sintered-silver bonding on nickel metallization by robust metallic bonds; .(3) elucidate failure mechanisms of SiC power modules by describing the mechanical, thermal, and electrical properties and microstructures degradation rules during thermal shock, power cycling, and temperature-humidity life tests, and develop a failure criterion for guiding the high-reliability design based on the Weibull statistic and Coffin-Manson models. .Achieving these objectives would help lower the cost and simplify the process of substrate metallization by using Ni-plating instead of noble metal (such as Au and Ag) plating, and promote the expansion of sintered silver bonding materials and technology for packaging reliable high-temperature SiC power modules.