The effects of Bi addition on the growth of intermetallic compound (IMC) formation in Sn-3.8Ag-0.7Cu solder joints were investigated. The test samples were prepared by conventional surface mounting technology. To inve...The effects of Bi addition on the growth of intermetallic compound (IMC) formation in Sn-3.8Ag-0.7Cu solder joints were investigated. The test samples were prepared by conventional surface mounting technology. To investigate the element diffusion and the growth kinetics of intermetallics formation in solder joint, isothermal aging test was performed at temperatures of 100, 150, and 190℃, respectively. The optical microscope (OM) and scanning electron microscope (SEM) were used to observe microstructure evolution of solder joint and to estimate the thickness and the grain size of the intermetallic layers. The IMC phases were identified by energy dispersive X-ray (EDX) and X-ray diffractometer (XRD). The results clearly show that adding about 1.0% Bi in Sn-Ag-Cu solder alloy system can refine the grain size of the IMC and inhibit the excessive IMC growth in solder joints, and therefore improve the reliability of the Pb-free solder joints. Through observation of the microstructural evolution of the solder joints, the mechanism of inhibition of IMC growth due to Bi addition was proposed.展开更多
Electromigration is a main challenge in the pursuit of power electronics, because physical limit to increase current density in power electronics is electromigration (EM), whereas much higher electrical current and vo...Electromigration is a main challenge in the pursuit of power electronics, because physical limit to increase current density in power electronics is electromigration (EM), whereas much higher electrical current and voltage are required for power electronics packaging. So the effect of EM is an important issue in applications where high current densities are used, such as in microelectronics and related structures (e.g., Power ICs). Since the structure size of integrated circuits (ICs) decreases and the practical significance of this effect increases, the result is EM failure. On the other hand, in the next generation power electronics technology electrical current density is expected to exceed 10<sup>7</sup> A/cm<sup>2</sup> which is another challenge. This review work has been carried out to identify the mechanism of EM damage in power electronics (e.g., pure metallization and solder joints) and also how to control this kind of damage.展开更多
文摘The effects of Bi addition on the growth of intermetallic compound (IMC) formation in Sn-3.8Ag-0.7Cu solder joints were investigated. The test samples were prepared by conventional surface mounting technology. To investigate the element diffusion and the growth kinetics of intermetallics formation in solder joint, isothermal aging test was performed at temperatures of 100, 150, and 190℃, respectively. The optical microscope (OM) and scanning electron microscope (SEM) were used to observe microstructure evolution of solder joint and to estimate the thickness and the grain size of the intermetallic layers. The IMC phases were identified by energy dispersive X-ray (EDX) and X-ray diffractometer (XRD). The results clearly show that adding about 1.0% Bi in Sn-Ag-Cu solder alloy system can refine the grain size of the IMC and inhibit the excessive IMC growth in solder joints, and therefore improve the reliability of the Pb-free solder joints. Through observation of the microstructural evolution of the solder joints, the mechanism of inhibition of IMC growth due to Bi addition was proposed.
文摘Electromigration is a main challenge in the pursuit of power electronics, because physical limit to increase current density in power electronics is electromigration (EM), whereas much higher electrical current and voltage are required for power electronics packaging. So the effect of EM is an important issue in applications where high current densities are used, such as in microelectronics and related structures (e.g., Power ICs). Since the structure size of integrated circuits (ICs) decreases and the practical significance of this effect increases, the result is EM failure. On the other hand, in the next generation power electronics technology electrical current density is expected to exceed 10<sup>7</sup> A/cm<sup>2</sup> which is another challenge. This review work has been carried out to identify the mechanism of EM damage in power electronics (e.g., pure metallization and solder joints) and also how to control this kind of damage.
