Experimental Study of Damage Mechanism of Carbon Nanotube as Nano-Component of Electronic Devices Under High Current Density

Author(s):  
Kazuhiko Sasagawa ◽  
Kazuhiro Fujisaki ◽  
Jun Unuma ◽  
Ryota Azuma

Carbon nanotube (CNT) has a great tolerance to high current density which is a cause of electromigration (EM). Therefore, CNT is expected to use as the materials of nanoscale components of electronic devices. The damage mechanisms of CNT are regarded as the effects of oxidation by Joule heating and/or the EM by high-density electron flows. In this study, we investigated the damage mechanism of CNT structures used as nano-component of electronic devices. An EM acceleration testing system was designed using the CNT structures collected at the gap of thin-film electrodes. The EM tests were conducted under the several kinds of current density conditions and the surrounding environments. An indicator of lifetime was determined by voltage measurements during the acceleration tests and their fracture phenomena were evaluated by means of microscopic observations. As the results, the amounts of lifetime of CNT were longer in the lower oxygen concentrations than in the air condition. In the microscopic studies, it was confirmed that the local evaporation of carbon atoms due to oxidation appeared at the cathode side of the CNT structures under low current density, and the center area of CNT under high current density. Both types of damage morphologies induced by oxidation and EM were observed at the damaged CNT. The results showed the dominant damage mechanism alternated between oxidation and EM depending on current density under oxygen rich conditions.

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Kazuhiko Sasagawa ◽  
Kazuhiro Fujisaki ◽  
Jun Unuma ◽  
Ryota Azuma

The damage mechanisms of carbon nanotubes are considered to be the oxidation by Joule heating and migration of carbon atoms by high-density electron flows. In this study, a high current density testing system was designed and applied to multiwalled carbon nanotubes (MWCNTs) collected at the gap between thin-film electrodes. Local evaporation of carbon atoms occurred on the cathode side of the MWCNTs under relatively low current density conditions, and the center area of the MWCNTs under high current density conditions. The damaged morphology could be explained by considering both Joule heating and electromigration behavior of MWCNTs.


2017 ◽  
Vol 2017 (1) ◽  
pp. 000093-000096
Author(s):  
Seungjun Noh ◽  
Chanyang Choe ◽  
Chuantong Chen ◽  
Shijo Nagao ◽  
Katsuaki Suganuma

Abstract This work introduces the possibility of using Ag sinter-paste as a novel high-temperature and high-current wire bonding solution. We investigated the electromigration (EM) behavior and lifetime of the sintered Ag wiring under high current density and high temperature required for the design of power electronic devices. The sinter Ag wiring fabricated on the two Cu substrates were tested under current densities of 2.7 × 104 A/cm2 at temperature of 250 °C. The microstructure evolution of sintered wiring was characterized after EM test. The resistance of sintered wiring did not change even after EM test for 300 hours, which confirms that the Ag-paste sinter wire bonding is rather stable than aluminum wire bonding under high temperature and high current density. No degradation was observed in microstructure of sintered wiring after EM test. Thus, it is expected that Ag paste sinter wire bonding is one of potential alternative interconnection technology for power electronic devices.


Author(s):  
ZK Li ◽  
Zhekun Fan ◽  
Long Dou ◽  
Zhong Jin ◽  
Zhan Liu ◽  
...  

Abstract Under the action of electro-thermal-mechanical coupling, the failure and performance degradation of electronic devices are prone to occur, which has become a particularly important reliability problem in microelectronic packaging. The improvement of flip chip reliability by using thermal interface materials was studied. First, a three-dimensional finite element model of the flip-chip packaging system, and finite element simulation of electric-thermal-force multi-field coupling were conducted, and the Joule heating, temperature distribution, thermal stress and deformation of the flip-chip under high current density was analyzed. At the same time, the influence of thermal interface material thermal conductivity and operating current on flip chip reliability was studied. Then, the reliability experiment of the flip chip connected to the radiator under high current density was performed, and the temperature change in the flip chip under different thermal interface materials was obtained. Finally, through the combination of experiment and simulation, the influence of thermal interface materials on flip chip reliability was analyzed. It is further confirmed that the reliability and service life of electronic devices were effectively improved by using the high thermal conductivity BNNS/epoxy composite material prepared in this paper.


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