Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,t...Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,the three primary micro-defect types at potential stress concentrations in sintered AgNPs are identified,categorized,and quantified.Molecular dynamics(MD)simulations are employed to observe the failure evolution of different microscopic defects.The dominant mechanisms responsible for this evolution are dislocation nucleation and dislocation motion.At the same time,this paper clarifies the quantitative relationship between the tensile strain amount and the failure mechanism transitions of the three defect types by defining key strain points.The impact of defect types on the failure process is also discussed.Furthermore,traction-separation curves extracted from microscopic defect evolutions serve as a bridge to connect the macro-scale model.The validity of the crack propagation model is confirmed through tensile tests.Finally,we thoroughly analyze how micro-defect types influence macro-crack propagation and attempt to find supporting evidence from the MD model.Our findings provide a multi-perspective reference for the reliability analysis of sintered AgNPs.展开更多
In the field of aerospace,power electronics have a broad range of applications.The advent of SiC power devices could markedly improve the performance of existing systems and enable new applications.However,this potent...In the field of aerospace,power electronics have a broad range of applications.The advent of SiC power devices could markedly improve the performance of existing systems and enable new applications.However,this potential cannot be fully realized if SiC dies are packaged with conventional materials and processes that limit performance in areas such as maximum operating temperature and parasitic elements.More importantly,the reliability of SiC device interconnection is also influenced by packaging technology.Compared to solder material,nano-silver sintering offers several advantages:its thermal conductivity is higher than that of solder,and its melting point of 960℃ is markedly greater than that of solder.Additionally,the electromigration rate of nano-silver is typically 1 to 2 orders of magnitude lower than that of solder.These advantages result in superior electrical and thermal performance,as well as enhanced reliability for silicon carbide power modules.This paper provides an overview of nano-silver sintering technology from the perspective of reliability,summarizing considerations for more reliable materials and processes.It also assesses long-term reliability by investigating failure modes observed in standard tests and applications of sintered joints.Challenges and prospects of using this technology in space applications are also discussed.展开更多
基金supported by the China Scholarship Council (CSC) (No.202206020149)the Academic Excellence Foundation of BUAA for PhD Students,the Funding Project of Science and Technology on Reliability and Environmental Engineering Laboratory (No.6142004210106).
文摘Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,the three primary micro-defect types at potential stress concentrations in sintered AgNPs are identified,categorized,and quantified.Molecular dynamics(MD)simulations are employed to observe the failure evolution of different microscopic defects.The dominant mechanisms responsible for this evolution are dislocation nucleation and dislocation motion.At the same time,this paper clarifies the quantitative relationship between the tensile strain amount and the failure mechanism transitions of the three defect types by defining key strain points.The impact of defect types on the failure process is also discussed.Furthermore,traction-separation curves extracted from microscopic defect evolutions serve as a bridge to connect the macro-scale model.The validity of the crack propagation model is confirmed through tensile tests.Finally,we thoroughly analyze how micro-defect types influence macro-crack propagation and attempt to find supporting evidence from the MD model.Our findings provide a multi-perspective reference for the reliability analysis of sintered AgNPs.
文摘In the field of aerospace,power electronics have a broad range of applications.The advent of SiC power devices could markedly improve the performance of existing systems and enable new applications.However,this potential cannot be fully realized if SiC dies are packaged with conventional materials and processes that limit performance in areas such as maximum operating temperature and parasitic elements.More importantly,the reliability of SiC device interconnection is also influenced by packaging technology.Compared to solder material,nano-silver sintering offers several advantages:its thermal conductivity is higher than that of solder,and its melting point of 960℃ is markedly greater than that of solder.Additionally,the electromigration rate of nano-silver is typically 1 to 2 orders of magnitude lower than that of solder.These advantages result in superior electrical and thermal performance,as well as enhanced reliability for silicon carbide power modules.This paper provides an overview of nano-silver sintering technology from the perspective of reliability,summarizing considerations for more reliable materials and processes.It also assesses long-term reliability by investigating failure modes observed in standard tests and applications of sintered joints.Challenges and prospects of using this technology in space applications are also discussed.
