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Electromigration of Ni Plating/Sn-0.7Cu Based Joint System of Power Modules for Hybrid Vehicles
Technical Paper
2017-01-1239
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Power modules are used to operate three-phase alternating current motors in hybrid vehicles and electric vehicles. Good fuel efficiency and high power density are required in the field of hybrid vehicles. To achieve this goal, the miniaturization of the power module will be necessary. This trend may make a current density, which is created by insulated gate bipolar transistors (IGBTs) and free wheel diodes (FWDs), higher in power modules. Solder is often used as the joint material of power modules. It is known that a current density larger than 10 kA/cm2 causes solder electromigration. This phenomenon may cause delamination of the joint area. In addition, the ambient temperature has an influence on electromigration. The temperature of an engine compartment is high, so it is likely to cause electromigration. However, the current density of the double-sided cooling power modules in 2007 with solder joint is lower than 0.4 kA/cm2, and this value is lower than 10 kA/cm2. This current density is not so severe to the solder joint system. Black’s equation shows that current density and the temperature have an effect on the mean time to failure (MTTF). We investigated mechanisms of electromigration when applying a current density lower than 10 kA/cm2. In this research, the solder joint system was composed of Ni plating/Sn-0.7Cu. The diffusion ratio of Ni was different between the cathode side and the anode side. The diffusion ratio of the cathode side was higher than that of the anode side. In addition, the thickness of the intermetallic compound (IMC) was larger at the anode side than that at the cathode side. The electromigration of Ni plating/Sn-0.7Cu based joint system with a current density lower than 10 kA/cm2 was clarified.
Authors
Citation
Take, N., Kadoguchi, T., Noguchi, M., and Yamanaka, K., "Electromigration of Ni Plating/Sn-0.7Cu Based Joint System of Power Modules for Hybrid Vehicles," SAE Technical Paper 2017-01-1239, 2017, https://doi.org/10.4271/2017-01-1239.Also In
References
- Black J. R. , Electromigration- A Brief Survey and Some Recent Results IEEE Transactions on Electron Devices 16 338 347 1969
- Tu K. N. , Recent advances on electromigration in very-large-scale-integration of interconnects Journal of Applied Physics 94 5451 5473 2003 10.1063/1.1611263
- Miura S. Development of Power Devices for Power Cards Denso Technical Reviews 16 38 45 2011
- Hirose S. , Power electronics technology for the next generation environmentally-friendly vehicles Proceedings. of the 24th Microelectronics Symposium JIEP Japan 37 2014
- Yeh Y. T. Threshold current density of electromigration in eutectic SnPb solder Applied Physics Letters 86 203504 2005 10.1063/1.1929870
- Hongwen H. Electromigration-induced cracks in Cu/Sn3.5Ag/Cu solder reaction couple at room temperature Journal of Semiconductors 30 033006 1 2009 10.1088/1674-4926/30/3/033006
- Zhao JH , Gupta V , Zeng KJ Electromigration-Resistant Flip-Chip Solder Joints US patent 20080251927 A1
- Chen H. Y. Effect of under-bump-metallization structure on electromigration of Sn-Ag solder joints Advances in Materials Research 1 83 92 2012 10.12989/amr.2012.1.1.083
- Wu S. H. Electromigration Study on Sn (Cu) Solder/Ni(P) Joint Interface Journal of Electronic Materials 41 3342 3347 2012 10.1007/s11664-012-2301-5
- Kadoguchi T. Electromigration behavior in Cu/Ni-P/Sn-Cu based joint system with low current density Microelectronics Reliability 55 2554 2559 2015 10.1016/j.microrel.2015.10.003