Effect of New Types of PCB Surface Finishes on Fractographic Morphology of Solder Joints

The aim of this paper was to study the fracture mechanisms of soldered joints after the shear test and to examine the interrelationships between the mechanical strength and the corresponding fracture morphologies. In our article, we compared 4 standard types of PCB surfaces (ENIG, ImSn, SnHASL, Cu) with 4 new developed type surface finishes based on SnAg. The smallest susceptibility to brittle failure and susceptibility to aging compared to other finishes was also demonstrated by the fractographic analysis of the fracture surfaces SnAg based surface. Overall, SnAg5 showed higher shear strength, greater pseudo-ductility and toughness than ENIG.