Purpose This study aims to develop a bimodal nano-silver paste with improved mechanical property and reliability. Silicon carbide (SiC) particles coated with Ag were introduced in nano-silver paste to improve bonding strength between SiC and Ag particles and enhance high-temperature stability of bimodal nano-silver paste. The effect of sintering parameters such as sintering temperature, sintering time and the proportion of SiC particles on mechanical property and reliability of sintered bimodal nano-silver structure were investigated. Design/methodology/approach Sandwich structures consist of dummy chips and copper substrates with nickel and silver coating bonded by nano-silver paste were designed for shear testing. Shear strength testing was conducted to study the influence of SiC particles proportions on the mechanical property of sintered nano-silver joints. The reliability of the bimodal nano-silver paste was evaluated experimentally by means of shear test for samples subjected to thermal aging test at 150°C and humidity and temperature testing at 85°C and 85 per cent RH, respectively. Findings Shear strength was enhanced obviously with the increase of sintering temperature and sintering time. The maximum shear strength was achieved for nano-silver paste sintered at 260°C for 10 min. There was a negative correlation between the proportion of SiC particles and shear strength. After thermal aging testing and humidity and temperature testing for 240 h, the shear strength decreased a little. High-temperature stability and high-hydrothermal stability were improved by the addition of SiC particles. Originality/value Submicron-scale SiC particles coated with Ag were used as alternative materials to replace part of nano-silver particles to prepare bimodal nano-silver paste due to its high thermal conductivity and excellent mechanical property.

中文翻译：

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Ag包覆SiC颗粒双峰纳米银浆的力学性能和可靠性

目的本研究旨在开发一种具有改进机械性能和可靠性的双峰纳米银浆。在纳米银浆中引入了包覆有银的碳化硅 (SiC) 颗粒，以提高 SiC 和 Ag 颗粒之间的结合强度，增强双峰纳米银浆的高温稳定性。研究了烧结温度、烧结时间、SiC颗粒配比等烧结参数对烧结双峰纳米银结构力学性能和可靠性的影响。设计/方法/途径三明治结构由虚拟芯片和铜基板组成，镍和银涂层由纳米银浆粘合，用于剪切测试。通过剪切强度试验研究了SiC颗粒配比对烧结纳米银接头力学性能的影响。双峰纳米银浆的可靠性通过剪切试验对样品进行150°C热老化试验和85°C和85%RH的湿度和温度试验进行实验评估。结果 随着烧结温度和烧结时间的增加，剪切强度明显提高。在 260°C 下烧结 10 分钟的纳米银浆达到最大剪切强度。碳化硅颗粒比例与剪切强度呈负相关。经过240 h的热老化试验和温湿度试验，剪切强度略有下降。通过添加 SiC 颗粒，提高了高温稳定性和高水热稳定性。独创性/价值 以Ag包覆的亚微米级SiC颗粒作为替代材料替代部分纳米银颗粒制备双峰纳米银浆，由于其具有高导热性和优异的机械性能。