摘要:
A hybrid mounting method using a Pb-free solder alloy including a reflow soldering step of soldering a surface mounting component 2 to at least the upper surface of a circuit board 1 using a Pb-free solder paste comprising an alloy based on Sn-(1-4)Ag-(0-1)Cu-(7-10)In (unit, mass %)-based alloy, an insertion step of inserting a lead or a terminal of an insertion mounting component 5 into a through hole perforated through the circuit board 1 from the upper surface thereof, a flux coating step, a preheating step, and a flow soldering step of spraying a jet flow 3 of Pb-free solder to the lower surface of the circuit board 1 preheated by the preheating step, thereby flow soldering the lead or the terminal of an insertion mounting component 5 to the circuit board.