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> Lead is added to solder because it lowers the melting point. It forms a eutectic alloy. Pure tin already has a melting point of 230 °C. Yes, Sn63Pb37 (argua
by blattimwind 8y ago
> Lead is added to solder because it lowers the melting point. It forms a eutectic alloy.
Pure tin already has a melting point of 230 °C. Yes, Sn63Pb37 (arguably the best solder alloy ever created) has a somewhat lower melting point at around 180 °C but no one uses such low temperatures except when absolutely necessary.
Being able to make the alloy eutectic is yet-another advantage, but the main concern was clearly tin whiskers, because these were breaking devices in the field.