Relationship of soldering profile, voids, formation and strength of soldered joints

This paper deals with relationship of soldering profile, void formation and mechanical strength of resulted solder joints. An experiment was design for this purpose. For the experiment, four solder paste (BiSnAg, SAC305, Sn100C, SnSb) and three surface finishes of PCB (ENIG, immersion Ag, immersion Sn) were used. Chip resistors 1206 were soldered by different soldering profile. The soldered joints were observed by X-ray and the void areas were calculated. The mechanical strength of the joints was measured after that. From the results, it is possible to find out the influence of surface finishes, soldering profiles or solder alloys on the formation of voids (area) and on the mechanical strength of joints