The investigation of a prospective lead-free solder alloy provides the essential data for microelectronic applications and estimation of solder joint reliability. In this study, we used the rotary magnetic field (RMF) as a novel approach to improve the mechanical performance and microstructure of Sn-2.0Ag-0.5Cu-2.0Zn (SACZ) lead-free solder alloy. The results revealed that both microstructure evolution and tensile characteristics enhanced by applying RMF. Microstructure studies showed that applying RMF reduced the grain size of β-Sn and IMCs. These modifications improved the tensile strength of the solder alloy. RMF improved Ultimate tensile strength (UTS), Yield stress (YS), Young modulus (E), and Elongation (El.%) of SACZ at room temperature by ~110%, 112%, 119%, and 108%, respectively. Besides, stress exponent, n, over the entire temperature and activation energy, Q, parameters calculated using the Garofalo hyperbolic sine law. n values were 5.9–8.3for SACZ alloy and 6.8–9.6 for SACZ-B alloy. Q values were ~ 51.8 kJ/mol for SACZ alloy and 79.2 kJ/mol for SACZ-B alloy close to pipe diffusion-controlled creep of tin. According to results, RMF is a promising approach to develop the microstructure evolution and mechanical characteristics of alloys. We hoped that the results would be useful for microelectronic applications.