Vibration Durability of Sn3.0Ag0.5Cu (SAC305) Solder Interconnects: Harmonic and Random Excitation

Abstract

In this study, the durability of lead (Pb)-free tin(Sn3.0)silver(Ag0.5)copper(Cu) (SAC305) printed wiring assemblies (PWAs) is investigated under constant amplitude, narrow-band (harmonic) excitation and under step-stress broad-band (random) excitation, and compared to the durability of Pb-based Sn37Pb PWAs. The results show that Sn37Pb assemblies last longer than SAC305 assemblies at similar excitation levels, for both harmonic and random excitations used in this study. The test specimens are identical for all tests, consisting of a PWA with plastic ball grid array components, quad flat pack components, leadless ceramic chip carriers, and leadless chip resistors. The test matrix includes test boards with different kinds of finishes and different aging conditions. Both the harmonic and random vibration tests are conducted on single-axis electrodynamic shakers. The harmonic vibration excitation is applied to a single specimen at a time, while the random vibration excitation is applied simultaneously to 20 ...