Some information on the web regarding RoHS and tip life...
What problems are there for using Lead-free solder?
? Higher melting point of Lead-free solder may cause physical and thermal damage to components and PCB. ? Lead-free solder has poor wetting ability and therefore needs a more active (corrosive) ? Flux to improve wetting. ? Lead-free solder joints need longer time to solidify. ? The solder point will appear dull in color. ? The high tin content of Lead-free solder will shorten life time of the soldering tips.
How to cope with the above problems?
? Do not try to increase the temperature of the soldering tip to accommodate for higher melting point, because this will cause more damage to components and PCB. ? Also, higher temperature will only make soldering of Lead-free solder even more difficult because more oxidation will form causing even worse wetting. ? Keep using the same temperature as normal with tin/lead solder. ? Instead, choose the largest soldering tip possible for the joint, and use a high power soldering iron. ? This way, the larger tip (with larger volume mass) has better heat retention and the fast thermal recovery of the tip will help smooth out the Lead-free soldering process.
Why does Lead-free solder shorten life time of soldering tips?
? Tin itself is a very active metal. ? Tin reacts with the iron (Fe) layer of soldering tips and the iron layer is eroded away. ? The higher the temperature, the faster the erosion speed. ? With almost all Lead-free solder, the percentage of tin is over 90%. ? Since there is higher tin content, with higher temperature and presence of more active flux, the erosion of soldering tips occurs faster than regular tin/lead solder.
How should we care for the soldering tip to extend the life?
? Keep the tip the cleanest possible during use. ? Always TIN the tip before putting the soldering iron back in the holder. ? If you are not using the soldering iron for a while, e.g. over 10 minutes, turn off the soldering iron. ? Use the lowest possible soldering temperature.
Hope this helps.
Chris
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