Comparison of Gold-Plated PCB Finishes

In this work, two surface fimishes- Electroless Nickel Immersion Gold (ENIG) and Galvanic Gold were compared. Solder joints were tested with respect to used materials (ENIG and Galvanic Goldfimishes, lead-free solders SAC305 M8, SAC305 NC257-2), used technologies (heating factor of 218 $s^{\circ}C$ and 2295 $s^{\circ}C$). The resistance of soldered joints was measured on prepared samples. The measurement results showed the influence of the heating factor on the resistance of solderedjoints. With a heating factor of 218 $s^{\mathrm{o}}C$, the resistance of the joint is higher than that of a soldered joint realized using a higher heatingfactor, except for samples with a galvanic coating. A destructive shear strength test was also conducted. The results showed that heating factor may affect reliability of the solderedjoint as the shear strength is influenced. In the case of SAC305 M8 solder, the shear strength values of the solderedjoints with heating factor of 2295 $s^{\circ}C$ are approximately 21% higher, with the exception of the sample with half thickness of the standard thickness of ENIG surface fimish. The SAC305 NC257-2 solder does not have big differences in shear strength at lower and higher heating factors during reflow.