Effect of small Sn-Ag-Cu additions on structure and properties of Sn-Zn-Bi solder/BGA during as-soldered and as-aged conditions

Asit Kumar Gaina, Y. C. Chan, Ahmed Sharif, Kam Chuen Yung

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)


Sn-8Zn-3Bi solder balls with different weight percentages of Sn-Ag-Cu addition were bonded to Au/Ni metallized Cu pads, and the effect of multiple reflow and aging on impact reliability was investigated. In the Sn-Ag-Cu content Sn-Zn-Bi solder joints, the AgZn3 intermetallic compound layer was clearly observed at the interfaces and its thickness increased with an increase the number of reflow cycles and aging time. In the solder ball region, fine acicularshaped Zn-rich phase and spherical-shaped AgZn3 compound particles were found in β-Sn matrix. The shear strength of monolithic Sn-Zn-Bi and 7wt% Sn-Ag-Cu content Sn-Zn-Bi solder joints after one reflow cycle were about 44.5MPa and 53.1MPa, respectively while their shear strengths after eight reflow cycles were about 43.4MPa and 51.6MPa, respectively. The fracture surface of monolithic Sn-Zn-Bi solder exhibited a semi ductile fracture mode with a smooth surface while Sn-Zn-Bi solder joints containing Sn-Ag-Cu particles showed a typical ductile failure with very rough dimpled surfaces.
Original languageEnglish
Title of host publication2009 Proceedings 59th Electronic Components and Technology Conference, ECTC 2009
Number of pages6
Publication statusPublished - 12 Oct 2009
Event2009 59th Electronic Components and Technology Conference, ECTC 2009 - San Diego, CA, United States
Duration: 26 May 200929 May 2009


Conference2009 59th Electronic Components and Technology Conference, ECTC 2009
Country/TerritoryUnited States
CitySan Diego, CA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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