STUDY OF BGA SOLDER JOINTS INTERFACIAL FAILURE MECHANISM RELATED TO WAVE SOLDERING

摘要

A BGA solder joint open case was discussed. The BGA was on topside of the board and the bottom side component was assembled by wave soldering process. Failure analysis with Dye & Pry, Cross section, SEM/EDX showed that it was a typical interfacial brittle fracture of BGA package side. Sn-Ni-Cu ternary intermetallic compound (IMC) exposed at fracture of BGA substrate. Detail examination of the physical cause of this failure was presented in this paper. Several potential root causes including secondary reflow of the solder joints, ternary IMC were analyzed.