EVERYTHING YOU NEED TO KNOW ABOUT LEAD-FREE SOLDER

Lead-free solder alloys have been garnering quite a lot of interest in the industry, particularly after the advent of the RoHS and WEEE directives that are focusing on ridding electronics manufacturing industry from the use of lead as a vital raw material. Traditional tin lead soldering techniques have been designed to suit the specific needs of the alloys that are no longer in compliance with RoHS.  Lead-free soldering requires managing a whole new set of variables. Here is everything you need to know for creating reliable and viable solder joints for your circuit board using Lead-free  alloys.

·         Lead-free alloys have a much higher melting point than its traditional tin lead counterparts. This means all your process steps and materials must be tweaked/modified to withstand the high temperature requirements of lead-free soldering.

·         Various flux varieties are incapable of sustaining through the increased temperatures necessary for soldering with lead-free alloys. It can get charred and coat your soldering tip and other circuit board surfaces, making re-tinning virtually impossible.

·         The appearance of your solder joints will also change with the switch-over to lead-free alloys. While the result of tin lead alloys is a shiny and even surfaced, the lead-free versions will appear to be duller and coarser.

·         Higher melting points of lead-free alloys means extended dwell times as the wetting process will take a bit longer to complete. You will therefore, have to tweak your soldering operations accordingly.

·         Another factor to take care of when using lead-free alloys is the possibility of bridging and creation of tin whiskers. You will need a lot of practice at handling the soldering iron to ensure the above issues don’t creep up and disrupt the circuitry of your board.

·         Lead-free alloys are also more prone to oxidation owing to the higher temperature they need for becoming wettable. The flux application and surface cleaning steps in your soldering process will therefore, have to be tweaked accordingly.

Keep the above factors in mind and you won’t face any issues while using lead-free alloys for your soldering needs.