caa a22 4500 463233441 CHVBK 20180405153249.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s10853-006-1234-x doi (NATIONALLICENCE)springer-10.1007/s10853-006-1234-x Multiple reflow study of ball grid array (BGA) solder joints on Au/Ni metallization [Elektronische Daten] [W. Zhong, Y. Chan, B. Wu, M. Alam, J. Guan] This paper evaluates the shearing behavior of ball grid array (BGA) solder joints on Au/Ni/Cu pads of FR4 substrates after multiple reflow soldering. A new Pb-free solder, Sn-3Ag-0.5Cu-8In (SACI), has been compared with Sn-3Ag-0.5Cu (SAC) and Sn-37Pb (SP) solders, in terms of fracture surfaces, shearing forces and microstructures. Three failure modes, ball cut, a combination of solder shear and solder/pad bond separation, and pad lift, are assessed for the different solders and reflow cycles. It is found that the shearing forces of the SP and SAC solder joints tend to increase slightly with an increase in the number of reflow cycles due to diffusion-induced solid solution strengthening of the bulk solder and augmentation of the shearing area. However, the shearing forces of the SACI solder joints decrease slightly after four cycles of reflow, which is ascribed to the thermal degradation of both the solder/intermetallic compound (IMC) and IMC/Ni interfaces. The SACI solder joints yield the highest strengths, whereas the SP solder joints give the smallest values, irrespective of the number of reflow cycles. Thickening of the interfacial IMC layer and coarsening of the dispersing IMC particles within the bulk solders were also observed. Nevertheless, the variation of shearing forces and IMC thickness with different numbers of reflow cycles was not so significant since the Ni under layer acted as an effective diffusion barrier. In addition, the initially-formed IMC layer retarded the further extensive dissolution of the pad material and its interaction with the solder. Springer Science+Business Media, LLC, 2007 Zhong W. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut Chan Y. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut Wu B. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut Alam M. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut Guan J. Department of Mineral Processing, Wuhan University of Science and Technology, Wuhan, P. R. China aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/13(2007-07-01), 5239-5247 0022-2461 42:13<5239 2007 42 10853 https://doi.org/10.1007/s10853-006-1234-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-1234-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhong W. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut NATIONALLICENCE 700 1- Chan Y. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut NATIONALLICENCE 700 1- Wu B. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut NATIONALLICENCE 700 1- Alam M. Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, P. R. China aut NATIONALLICENCE 700 1- Guan J. Department of Mineral Processing, Wuhan University of Science and Technology, Wuhan, P. R. China aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/13(2007-07-01), 5239-5247 0022-2461 42:13<5239 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer