Growth behavior of IMCs layer between Sn-3.0Ag-0.5Cu solder and Cu substrate during aging

Abstract

Growth behavior of intermetallic compounds (IMCs) layer between Sn-3.0Ag-0.5Cu solder and Cu substrate were studied during aging at 150 ℃ for 1 day, 3 days, 6 days, 8 days and 10 days, respectively. Results shows that the IMCs layer is scallop shape at aging stage, and the aspect ratio of scallop shape decreases with time increasing. Moreover, the IMCs layer grows thicker with extended aging time. Furthermore, the IMCs layer grows linearly with square root of aging time, and the growth kinetic equation of Sn-3.0Ag-0.5Cu/Cu solder joints is obtained by linear fit, which is X = 1.94 +1.95t1/2. Finally, the diffusion coefficient D is verified as 3.8025μm2/d.