The development of lead-free solders has emerged as one of the key issues in the electronics packaging industries.Bi-Sn-Ag eutectic alloy has been considered as one of the lead-free solder materials that can replace the toxic Pb-Sn eutectic solder without increasing soldering temperature.We investigated the effects of temperature gradient and growth rate on the mechanical,electrical and thermal properties of the BiSn-Ag ternary eutectic alloy.Bi-47 wt%Sn-0.68 wt%Ag alloy was directionally solidified upward with different temperature gradients(G=2.33-5.66 K/mm) at a constant growth rate(V=13.25 μm/s) and with different growth rates(V=6.55-132.83 μm/s) at a constant temperature gradient(G=2.33 K/mm) in the growth apparatus.The microstructures(λ),microhardness(HV),tensile stress(σ),electrical resistivity(ρ),and thermal properties(△H,C_p,T_m) were measured on directionally solidified samples.The dependency of the λ,HV,σ,and ρ on G and V was investigated.According to the experimental results,X values decrease with increasing G and V,but HV,λ,and ρ values increase with increasing G and V.Variations of electrical resistivity(ρ) for cast samples with the temperature in the range of 300-400 K were also measured by using a standard dc four-point probe technique.The enthalpy of fusion(△H) and specific heat(C_p) for the same alloy was also determined by means of differential scanning calorimeter(DSC) from heating trace during the transformation from eutectic liquid to eutectic solid. The development of lead-free solders has emerged as one of the key issues in the electronics packaging industries. Bi-Sn-Ag eutectic alloy has been considered as one of the lead-free solder materials that can replace the toxic Pb-Sn eutectic solder without increasing soldering temperature. We investigated the effects of temperature gradient and growth rate on the mechanical, electrical and thermal properties of the BiSn-Ag ternary eutectic alloy. Bi-47 wt% Sn-0.68 wt% Ag alloy was directionally solidified upward with different at constant temperature gradients (G = 2.33-5.66 K / mm) at a constant temperature gradient (V = 13.25 μm / s) and with different growth rates (V = 6.55-132.83 μm / / mm) in the growth apparatus. Microstructures (λ), microhardness (HV), tensile stress (σ), electrical resistivity (ρ), and thermal properties (ΔH, C_p, T_m) were measured on directionally solidified samples. dependency of the λ, HV, σ, and ρ on G and V was investigated. According to the experimenter tal results, X values ​​decrease with increasing G and V, but HV, λ, and ρ values ​​increase with increasing G and V. Variations of electrical resistivity (ρ) for cast samples with the temperature in the range of 300-400 K were also measured by using a standard dc four-point probe technique. The enthalpy of fusion (ΔH) and specific heat (C_p) for the same alloy was also determined by means of differential scanning calorimeter (DSC) from heating trace during the transformation from eutectic liquid to eutectic solid.