Effect of nano Ni additions on the structure and properties of Sn-9Zn and Sn-Zn-3Bi solders in Au/Ni/Cu ball grid array packages

Asit Kumar Gain, Y. C. Chan, Kam Chuen Yung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

59 Citations (Scopus)


The effect of nano Ni additions in Sn-9Zn and Sn-8Zn-3Bi solders on their interfacial microstructures and shear loads with Au/Ni/Cu pad metallization in ball grid array (BGA) applications were investigated. After the addition of nano Ni powder in Sn-based lead-free solders, there were no significant changes in the interfacial microstructure. But, in the solder region a very fine Zn-rich phase was observed. Also on the fracture surfaces a fine Zn-Ni compound was found. After the addition of nano Ni powder in Sn-based solders, the shear loads were increased due to a refinement of the microstructure and in addition, ductile fracture surfaces were clearly observed. The shear loads of the plain Sn-9Zn and Sn-8Zn-3Bi solders after one reflow cycle were about 1798 g and 2059 g, respectively. After the addition of nano Ni powder, their loads were about 2172 g and 2212 g, respectively, after one reflow cycle and their shear loads after eight reflow cycles were about 2099 g and 2081 g, respectively.
Original languageEnglish
Pages (from-to)92-98
Number of pages7
JournalMaterials Science and Engineering B: Solid-State Materials for Advanced Technology
Issue number2
Publication statusPublished - 25 May 2009


  • Ball grid array solder joints
  • Microstructure
  • Nano doping
  • Shearing force

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this