Abstract
The standoff height of ball grid array (BGA) structure solder joints has a significant influence on the formation and growth of interfacial intermetallic compounds (IMC). The results show that the thickness of the IMC layer at the solder/Cu interface of BGA structure Cu/Sn-3.0Ag-0.5Cu/Cu joints increases with decreasing standoff height after reflowing. The growth behavior of the total IMC layer is controlled by a diffusion process with the growth rate increasing with standoff height. Both the standoff height and isothermal aging time greatly influence the shear behavior of joints, the shear strength of which shows a parabolic trend with increasing standoff height, while the nominal shear strain decreases monotonically with increasing standoff height. The fracture location of BGA structure joints changed from the middle of the solder matrix to near the interface when the standoff height was increased. After undergoing isothermal aging at 125°C, the fracture mechanism of solder joints changed from ductile fracture to the mixed mode of brittle and ductile fracture with increasing standoff height.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
