A lead (Pb)-free, and silver (Ag)-free solder alloy includes a primary metallic element in a content of about 1.1 wt % to about 1.9 wt %, nickel(Ni) in a content of about 0.02 wt % to about 0.09 wt %, copper (Cu) in a content of about 0.2 wt % to about 0.9 wt %, and tin (Sn) and other unavoidable impurities in remaining balance, wherein the primary metallic element is at least one selected from the group including bismuth (Bi), chromium (Cr), indium (In), antimony (Sb), silicon (Si) and zinc (Zn).