Soldering printed circuit boards is different ! Printed circuit boards are printed with no-lead ink. This requires no-lead solder. Soldering with no-lead solder is a new skill many of must acquire.
For hand soldering, we use a alloy of tin, bismuth, and, silver. This is what is compatible with the printed conductor. If we try to use ‘old school’ tin-lead solder, the lead in the solder does something very bad to the printed conductor, with the result that the conductor will never ‘wet’ with solder.
If we pick up a soldering iron that has been used for tin-lead solder, the remnants of that on the solder iron tip is enough to cause great headaches when we try to solder with lead-free solder.
So, start with a new iron, or at least a new tip, and tin it with the appropriate lead-free solder.
Keep all your tin-lead soldering equipment separated from your lead-free soldering equipment. Label all of it. Educate your technicians and engineers. Do not even think about using the “wrong” iron for a quick repair job. You will undo all that work of separating the equipment.
Just as critical to successful DPCB production is proper burnishing.
We will cover more on the subject of ‘lead-free’ soldering in an upcoming post.