Effect of Carbon Inclusion in the Ni-P Coating on Shearing Behavior of Sn4Ag0.5Cu Ball Grid Array Solder Joints
This study employed an electroless Ni-P-carbon nanotubes (Ni-P-CNTs) composite coating as a pad finish for electronic packaging. It aimed at investigating the effect of carbon on the mechanical behavior and microstructure of ball grid array (BGA) solder joints after multiple reflows.Electroless Ni-P and electroless Ni-P-CNTs composite coatings with the same P-content were prepared for comparison. It was found that the carbon in the coating increased the brittleness of solder joints and weakened their shear strength. After shearing tests, more brittle fractures occurred in the intermetallic compound (IMC) layer in the Sn-4Ag-0.5Cu/Ni-P-CNTs (SAC/ Ni-P-CNTs) solder joints.After multiple retlows, a Ni3Sn4 IMC layer and a P-rich layer were formed in the solder joints on both coatings. The IMC layers in the SAC/Ni-P solder joints were found to be compact with chunky-shaped grains, whilst the IMC layers in the SAC/Ni-P-CNTs solder joints were porous with needle-shaped grains.
X.Gu Y.C.Chan B.Y.Wu D.Yang
Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue,Kowloon Tong, Hong Kong, P.R.China
国际会议
第八届电子封装技术国际会议(2007 8th International Conference on Electronics Packaging Technology ICEPT2007)
上海
英文
653-657
2007-08-14（万方平台首次上网日期，不代表论文的发表时间）