A lead free solder is provided. The lead free solder includes about 1.5 wt % to about 2.5 wt % silver (Ag), about 3 wt % to about 6 wt % bismuth (Bi), about 0.005 wt % to about 0.1 wt % of a deoxidizing agent, and a balance of tin (Sn). The lead free solder has improved wettability, a lowered melting point, little or substantially no formation of oxidation layer in a solder bath, suppressed brittleness, improved thermal shock resistance and drop resistance.