SOLDERING METHOD

摘要

PROBLEM TO BE SOLVED: To manufacture a printed circuit board without generating defective soldering and with the high reliability of its soldered parts by establishing a soldering method with which soldering with satisfactory wettability can be performed by using lead free solder when soldering the printed circuit board mounted with electronic parts. SOLUTION: When performing the flow soldering of the printed circuit board 1 by using Sn-Zn solder in an atmosphere of inert gas, the soldering is performed with an oxygen content of 500 ppm or below while moving the jet stream wave 13 of melted solder 9 making it come into contact with the printed circuit board 1 in a solodering process 18 in the direction crossing the transfer direction A of the printed circuit board 1.