Mechanical and microstructural enhancements of Ag microparticle-sintered joint by ultrasonic vibration
Mechanical and microstructural enhancements of Ag microparticle-sintered joint by ultrasonic vibration
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DOI：
10.1007/s10854-020-04684-x
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发表时间：
2020-10-24
影响因子：
2.8
通讯作者：
Nishikawa, Hiroshi
中科院分区：
文献类型：
--
作者：
Gao, Runhua;Shen, Yu-An;Nishikawa, Hiroshi
银微粒烧结键合技术是一种很有前途的功率器件芯片粘接技术。在这项研究中，超声波辅助键合方法，债券栗子毛刺状银微粒在低温下迅速报告。在类似于240 ℃（实际）7MPa的条件下，在300 s内实现了平均剪切强度为36.2MPa的坚固接头。通过对不同超声时间和功率下烧结组织的表征，研究了超声振动对烧结组织的影响。在超声振动作用下，形成了两种独特的微结构：微桥和致密层。前者实现了微粒烧结，后者使接头的断裂模式由脆性界面脱粘转变为韧性断裂。结果表明，微桥和致密层在一定范围内强化了接头，是局部塑性变形和局部高温驱动下的晶化过程。
Silver (Ag) microparticle sintering bonding is a promising die-attach method for power device packaging. In this study, an ultrasonic-assisted bonding method that bonds chestnut-burr-like Ag microparticles rapidly at low temperatures is reported. Robust joints with an average shear strength of 36.2 MPa were achieved under similar to 240 degrees C (actual) 7 MPa in 300 s. Based on characterization of sintered microstructures obtained with different ultrasonic time and power, effects of the ultrasonic vibration were studied. Two unique microstructures, microbridges and dense layers, were generated with the ultrasonic vibration. The former achieved microparticle sintering, and the latter changed fracture mode of the joints from brittle interfacial debonding to ductile fracture. The results indicate the microbridges and dense layers enhanced the joints within a certain range and are generated due to crystallization driven by localized plastic deformation and localized high temperatures.