| 摘要 |
PROBLEM TO BE SOLVED: To solve problems that it is necessary to supply a large quantity of insert gas due to generation of the unnecessary flow of an atmosphere in the inside of a tunnel shaped chamber when blowing hot air when preheating a printed circuit board in a flow type soldering device equipped with the tunnel shaped chamber in which the oxygen concentration is made low in addition to this, an oxygen content varies unstably, and lift-off failures are liable to occur when leadfree solder is used. SOLUTION: By providing the supply body 26 of N2 gas for cooling at the latter stage nearest to a peel back pint 36 at which the printing circuit board 1 is separated from jet stream wave 25 melted solder 11 to spray the cooling N2 gas, and the circuit board cool. This cooling N2 gas is collected by a gas collection port 37, after the circuit board is heated by the melted solder 11 during it passes through a pipe 38 provided inside a solder bath 12, it is heated further by a heater 14 for heating an atmosphere, and is used for preheating the printed circuit board 1. |
