一种纳米AgCu互连的SiC功率模块制造工艺和性能研究

发布时间：2018-03-05 19:20

  本文选题：纳米AgCu　切入点：烧结工艺　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着电力电子技术的不断发展,以SiC为代表的第三代宽禁带半导体相比传统的Si基半导体具备更高的禁带宽度、击穿电压与功率密度,因此必将成为电力电子器件技术发展的主流。然而在互连材料方面,现有的封装材料体系已经不能满足第三代半导体功率器件在高温工作环境下的要求。针对SiC芯片对粘接材料“低温互连,高温服役”的要求,科学界在纳米Ag材料上进行了大量的研究,发现其具备良好的导热导电性能的同时也具有孔隙率高以及易电迁移等缺点。因此本文针对纳米Ag的这些缺点,引入了Cu进行互补,研究纳米AgCu材料的烧结性能以及其在SiC器件中的实际应用性能。本文采用水溶液化学还原法制备纳米AgCu二元合金颗粒,并通过添加有机溶剂混合制成纳米焊膏,重点围绕纳米AgCu焊膏的烧结工艺,性能以及在器件中的应用展开研究。首先在不同工艺条件下用纳米AgCu焊膏烧结连接Cu-Cu接头,探索烧结温度,烧结时间,烧结压力三个因素对烧结组织的影响规律,并找到最佳工艺参数。为了探索纳米AgCu焊膏在实际应用中的表现,设计并制造了使用该焊膏互连的SiC全桥功率驱动模块,对模块的高温工作性能进行测试判断其高温服役稳定性。此外,加入两种对比连接材料对SiC功率芯片互连,通过比较判断在实际的器件应用中纳米AgCu的表现。最后,对纳米AgCu连接的芯片试验和Cu接头进行了高低温冲击循环和高温老化试验以研究纳米AgCu的可靠性。研究发现时间和温度是影响烧结组织性能的最重要的因素,当制备焊膏的纳米AgCu颗粒平均粒径为10nm时,烧结温度必须大于250℃纳米颗粒才能有效烧结融合,而保温时间越长则纳米AgCu烧结接头的组织越致密。相比之下,压力的影响要小一些,当压力大于5MPa后,再施加更大的压力,接头的力学性能的增强有限。对烧结后的纳米AgCu样品进行导电导热性能测试,测得电阻率最低可达到6.1μΩ·cm,导热系数最高可达到94.9 W/m K,能够满足大功率SiC工作的需求。最后在可靠性试验中发现该种焊膏烧结后残留的有机物对可靠性影响较大,所以其制备和烧结工艺还需要进一步研究改善。
[Abstract]:With the development of power electronics technology, the third generation wide band gap semiconductor, represented by SiC, has higher band gap, breakdown voltage and power density than traditional Si based semiconductor. Therefore, it will become the mainstream of the development of power electronic device technology. However, in the aspect of interconnection materials, The existing packaging material system can no longer meet the requirements of the third generation semiconductor power devices in the high-temperature working environment. For the SiC chip for bonding materials "low temperature interconnection, high temperature service" requirements, A great deal of scientific research has been done on nano-Ag materials, and it is found that the nano-Ag materials have good thermal conductivity and high porosity and easy electromigration. Therefore, in this paper, Cu is introduced to complement each other in view of these shortcomings of nano-Ag. The sintering properties of nano-sized AgCu materials and their practical application in SiC devices were studied. In this paper, nano-sized AgCu binary alloy particles were prepared by chemical reduction method in aqueous solution, and nano-solder paste was prepared by adding organic solvents. The research focuses on the sintering process, properties and application in the device of nanometer AgCu solder paste. Firstly, the Cu-Cu joint is sintered with nanometer AgCu solder paste under different technological conditions, and the sintering temperature and sintering time are explored. In order to explore the performance of nano-sized AgCu solder paste in practical application, a full-bridge power driving module of SiC interlinked with the paste was designed and manufactured. The high temperature service stability of the module is determined by testing its performance at high temperature. In addition, two kinds of contrast connecting materials are added to interconnect the SiC power chip, and the performance of nanometer AgCu in practical device application is judged by comparison. Finally, The high and low temperature impact cycling and high temperature aging tests were carried out to study the reliability of nano AgCu chips and Cu joints. It was found that time and temperature were the most important factors affecting the microstructure and properties of sintering. When the average size of AgCu particles prepared by solder paste is 10 nm, the sintering temperature must be more than 250 鈩，

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