Full Content is available to subscribers

Subscribe/Learn More  >

Elastic Properties of (Cu,Ni)6Sn5 Ternary Crystal Structure Using First-Principle Approach

[+] Author Affiliations
Feng Gao, Jianmin Qu

Georgia Institute of Technology, Atlanta, GA

Paper No. IMECE2009-11130, pp. 159-163; 5 pages
  • ASME 2009 International Mechanical Engineering Congress and Exposition
  • Volume 5: Electronics and Photonics
  • Lake Buena Vista, Florida, USA, November 13–19, 2009
  • Conference Sponsors: ASME
  • ISBN: 978-0-7918-4378-9 | eISBN: 978-0-7918-3863-1
  • Copyright © 2009 by ASME


The Cu6 Sn5 intermetallic compound (IMC) is an important interfacial reactive product in electronic packaging. The properties of Cu6 Sn5 have been demonstrated to be crucial to the interface reliability at the solder interconnections. Due to the element inter-diffusion between the packaging side and PCB (printed circuit board) side during soldering process, a ternary Cu6 Sn5 -based Cu-Ni-Sn intermetallic compound is often generated. This ternary phase exhibits a similar crystal structure as Cu6 Sn5 phase, in which the Ni atoms are regarded as the solubility by replacing the Cu atoms. Therefore, this Cu-Ni-Sn ternary phase is labeled as (Cu6−x , Nix )Sn5 . It has been found that the Cu6 Sn5 unit cell consists of 44 atoms, in which 24 atoms are Cu and 20 atoms are Sn. The 24 Cu atoms occupy 4a, 4e, 8f1 and 8f2 sites, while 20 Sn atoms occupy 4e, 8f1 and 8f2 sites. The reported experimental results are quite sparse and thus a fundamental calculation is required. In this paper, the elastic stiffness of (Cu6−x , Nix )Sn5 crystal structure is calculated based on the first-principle approach within density functional theory. The results indicate that Cu6 Sn5 phase show a nearly isotropic elasticity. However for the phase Cu5Ni1Sn5 (x = 1) where Ni atom at 4a space site, the elasticity shows slightly anisotropic. With the Ni solubility increase (x=2), the anisotropic elasticity of Cu4Ni2Sn5 phase becomes profound. The density of states (DOS) and partial density of states (PDOS) from individual element contributions, as well as the hybridization between the element states are simulated herein to reveal the mechanism of the anisotropic elasticity of (Cu6−x , Nix )Sn5 phase due to the occupancy of Ni atoms.

Copyright © 2009 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In