Notes

• Note excessive soldering times or temperatures and also rework. They are probably caused during soldering by differential expansions, i.e. between the printed circuit board substrate which expands a far greater distance than the metallic material of the joint b. lines running perpendicular to the mounting surface are commonly caused when the soldering iron bit is removed too slowly from a liquid solder joint c. lines running circumferentially around the mid section of the solder fillet caused by shrinkage during the last stage of solidification