Significant Features of Solder Connections to Gold-Plated Thin Films

An investigation of 60Sn-40Pb solder connections between phosphor-bronze clip-on terminals and Ti-Pd-Cu-Ni-Au and Ti-Pd-Au thin film terminations is described. The investigation consisted of measuring joint strength and analyzing resultant fracture interfaces and metallographic cross sections by scanning electron microscope-energy dispersive X-ray analysis (SEM-EDAX), electronmicroprobe (EMP), and X-ray diffraction, both initially and after accelerated temperature aging. Similarities and differences observed for the different terminals and termination conductors used in this, and previous investigations, are presented. Observations are explained by termination interdiffusion, intermetallic compound formation between terminal, termination, and solder constituents, and joint geometry related to the terminal design.