Effect of Ag micro-particles content on the mechanical strength of the interface formed between Sn-Zn binary solder and Au/Ni/Cu bond pads

S. K. Das, A. Sharif, Y. C. Chan, N. B. Wong, Kam Chuen Yung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

24 Citations (Scopus)


In this study, addition of Ag micro-particles with a content in the range between 0 and 4 wt.% to a Sn-Zn eutectic solder, were examined in order to understand the effect of Ag additions on the microstructural and mechanical properties as well as the thermal behavior of the composite solder formed. The shear strengths and the interfacial reactions of Sn-Zn micro-composite eutectic solders with Au/Ni/Cu ball grid array (BGA) pad metallizations were systematically investigated. Three distinct intermetallic compound (IMC) layers were formed at the solder interface of the Au/electrolytic Ni/Cu bond pads with the Sn-Zn composite alloys. The more Ag particles that were added to the Sn-Zn solder, the more Ag-Zn compound formed to thicken the uppermost IMC layer. The dissolved Ag-Zn IMCs formed in the bulk solder redeposited over the initially formed interfacial Au-Zn IMC layer, which prevented the whole IMC layer lifting-off from the pad surface. Cross-sectional studies of the interfaces were also conducted to correlate with the fracture surfaces.
Original languageEnglish
Pages (from-to)2086-2093
Number of pages8
JournalMicroelectronic Engineering
Issue number10
Publication statusPublished - 1 Oct 2009


  • Composite solder
  • Interfacial reaction
  • Mechanical property
  • Micro-particle
  • Sn-Zn eutectic solder
  • Thermal behavior

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering

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