PURPOSE: To provide a method and a machine for soldering a printed board in which an inert gas atmosphere can be brought about efficiently at a part where the printed board comes into contact with molten solder flow.
CONSTITUTION: The soldering method comprises a first step for transferring a printed board 11, a second step for coating the printed board 11 with organic acid based flux, a third step for transferring the printed board 11 from the second step into an inert gas atmospheric section 38 provided with a molten solder tank 19, and a fourth step for feeding molten solder flows 21, 23 to the printed board 11 in the inert gas atmospheric section 38. This method provides a good solderability while eliminating 'Freon(R)' gas cleaning step from soldering process.
HOSOYA NAOTO
TANAKA KURAHEI
