Solder joint reliability of Sn-Ag-Cu BGA and Sn-Pb solder paste

摘要

In the transition to lead-free, components suppliers need carry the product of lead-free and lead components. This could cause the extensive logistic problems in manufacturing. Therefore, it is necessary to study the solder joint character of Sn-Ag-Cu BGA and Sn-Pb solder paste. In this study, the results of solder joint shape and reliability evaluations of PBGA (plastic ball grid array) lead-free package assembled to PCBs (printed circuit boards) with eutectic Sn-Pb solder paste was presented. The lead-free package was assembled under various reflow profiles and PCB surface finish. The peak temperature of reflow soldering of 210, 225 and 235 /spl deg/C with the soak profile was used. The PCB surface finish included HASL (hot air soldering level) and ENIG (electro-less Ni/immersion Au). The different types of solder joints, both as-reflowed and after reliability test were examined using optical microscope, transmission X-Ray. The reliability test of TTC (thermal torsion cycling) and ATC (accelerated thermal cycling) was used. Detailed failure analysis is also presented.