It is in great demand that the Lead Free high temp solder which can prevent solder reflow (re-melted) again at a high temperature such as 260 C. for ten seconds.

This special feature is valid  for cases as during the second time lower temperature soldering process take place that the first high temp solder will not be reflowed again since the melting point is higher than the second.

It will replace the Leaded solder such as high Lead contained in the solder prevailed in the past.